Fmt fixes

Fix #245 and #250

.dockerignore

@@ -0,0 +1 @@
+*.tar.gz

.gitignore

@@ -1,3 +1,17 @@
 *.swp
-
 *.gor
+
+*.out
+
+*.bin
+
+*.gz
+
+*.class
+
+*.test
+.idea
+*.iml
+gor
+
+*.mprof

.travis.yml

@@ -1,3 +1,6 @@
-language: go 
-go: 1.1
-script: sudo -E bash -c "source /etc/profile && gvm use go1.1 && export GOPATH=$HOME/gopath:$GOPATH && go test -v"
+language: go
+go: 1.6
+script: sudo -E bash -c "source /etc/profile && eval '$(gimme 1.6)' && export GOPATH=$HOME/gopath:$GOPATH && go get && GORACE='halt_on_error=1' go test ./... -v -timeout 120s -race"
+
+before_install:
+  - sudo apt-get install libpcap-dev -y

CHANGELOG.md

@@ -1,25 +0,0 @@
-v0.7.0 - 31 Oct 2013
-* New modular architecture. Listener and Replay functionality merged.
-* Added option to equally split traffic between multiple outputs: --split-output true
-* Saving requests to file and replaying from it
-* Injecting custom headers to http requests
-* Advanced stats using ElasticSearch
-
-v0.3.5 - 15 Sep 2013
-* Significantly improved test coverage
-* Fixed bug with redirect replay https://github.com/buger/gor/pull/15
-* Added limit on listener side
-* Improved stability (catch and log panic, instead of exiting)
-* Added License file
-
-v0.3.3 - 22 Jun 2013
-* Using TCP instead of UDP for communication between Listener and Replay
-* Significantly improved performance
-* Fixed bugs causing locking and message dropping (concurrency issues)
-* Rewrote concurrency model to use more channels
-
-v0.3 - 10 Jun 2013
-* Use RAW_SOCKETS instead of tcpdump
-* Own TCP stack
-* All HTTP request types support
-* Simplified request parsing

COMM-LICENSE

@@ -0,0 +1,95 @@
+END-USER LICENSE AGREEMENT
+
+------------------------------------------------------------------------------
+
+IMPORTANT: THIS SOFTWARE END-USER LICENSE AGREEMENT ("EULA") IS A LEGAL AGREEMENT (“Agreement”) BETWEEN YOU (THE CUSTOMER, EITHER AS AN INDIVIDUAL OR, IF PURCHASED OR OTHERWISE ACQUIRED BY OR FOR AN ENTITY, AS AN ENTITY) AND CONTRIBUTED SYSTEMS. READ IT CAREFULLY BEFORE COMPLETING THE INSTALLATION PROCESS AND USING GOR PRO AND RELATED SOFTWARE COMPONENTS (“SOFTWARE”). IT PROVIDES A LICENSE TO USE THE SOFTWARE AND CONTAINS WARRANTY INFORMATION AND LIABILITY DISCLAIMERS. BY INSTALLING AND USING THE SOFTWARE, YOU ARE CONFIRMING YOUR ACCEPTANCE OF THE SOFTWARE AND AGREEING TO BECOME BOUND BY THE TERMS OF THIS AGREEMENT.
+
+------------------------------------------------------------------------------
+
+In order to use the Software under this Agreement, you must receive a “Source URL” at the time of purchase, in accordance with the scope of use and other terms specified for each type of Software and as set forth in this Section 1 of this Agreement. 
+
+1. License Grant
+
+1.1 General Use. This Agreement grants you a non-exclusive, non-transferable, limited license to the use rights for the Software, without the right to grant sublicenses, subject to the terms and conditions in this Agreement. The Software is licensed, not sold.
+
+1.2 Unlimited Organization License. If you purchased an Organization License (included with the Gor Pro Software), you may install the Software on an unlimited number of Hosts. “Host” means any physical or virtual machine which is controlled by you. You may also run an unlimited number of Workers. “Worker” means a thread within a Gor server process which executes jobs. You may concurrently run the software on an unlimited number of Hosts, with each host running an unlimited number of Workers.
+
+1.3 Limited Organization License. If you purchased an Organization License (included with the Gor Enterprise Software), you may install the Software on an unlimited number of Hosts. “Host” means any physical or virtual machine which is controlled by you. The aggregate number of Workers run by the hosts must not exceed the maximum number of Workers authorized at the time of purchase. “Worker” means a running Gor instance which intercept or replay traffic. In order to run additional Workers, you must purchase an additional allowance from Contributed Systems.
+
+1.4 Appliance License. If you purchased an Appliance License, you may distribute the Software in any applications, frameworks, or elements (collectively referred to as an “Application” or “Applications”) that you develop using the Software in accordance with this EULA, provided that such distribution does not violate the restrictions set forth in section 3 of this EULA. You must not remove, obscure or interfere with any copyright, acknowledgment, attribution, trademark, warning or disclaimer statement affixed to, incorporated in or otherwise applied in connection with the Software. You are required to ensure that the Software is not reused by or with any applications other than those with which you distribute it as permitted herein. For example, if You install the Software on a customer’s server, that customer is not permitted to use the Software independently of your Application. You must inform Contributed Systems of your knowledge of any infringing use of the Software by any of your customers. You are liable for compliance by those third parties with the terms and conditions of this EULA. You will not owe Contributed Systems any royalties for your distribution of the Software in accordance with this EULA.
+
+1.5 Archive Copies. You are entitled to make a reasonable amount of copies of the Software for archival purposes. Each copy must reproduce all copyright and other proprietary rights notices on or in the Software Product.
+
+1.6 Electronic Delivery. All Software and license documentation shall be delivered by electronic means unless otherwise specified on the applicable invoice or at the time of purchase. Software shall be deemed delivered when it is made available for download by you (“Delivery”).        
+
+2. Modifications. Contributed Systems shall provide you with source code so that you can create Modifications of the original software. “Modification” means: (a) any addition to or deletion from the contents of a file included in the original Software or previous Modifications created by You, or (b) any new file that contains any part of the original Software or previous Modifications. While you retain all rights to any original work authored by you as part of the Modifications, We continue to own all copyright and other intellectual property rights in the Software.
+
+3. Restricted Uses. 
+
+3.1 You shall not (and shall not allow any third party to): (a) decompile, disassemble, or otherwise reverse engineer the Software or attempt to reconstruct or discover any source code, underlying ideas, algorithms, file formats or programming interfaces of the Software by any means whatsoever (except and only to the extent that applicable law prohibits or restricts reverse engineering restrictions); (b) distribute, sell, sublicense, rent, lease or use the Software for time sharing, hosting, service provider or like purposes, except as expressly permitted under this Agreement; (c) redistribute the Software or Modifications other than by including the Software or a portion thereof within your own product, which must have substantially different functionality than the Software or Modifications and must not allow any third party to use the Software or Modifications, or any portions thereof, for software development or application development purposes; (d) redistribute the Software as part of a product, "appliance" or "virtual server"; (e) redistribute the Software on any server which is not directly under your control; (f) remove any product identification, proprietary, copyright or other notices contained in the Software; (g) modify any part of the Software, create a derivative work of any part of the Software (except as permitted in Section 4), or incorporate the Software, except to the extent expressly authorized in writing by Contributed Systems; (h) publicly disseminate performance information or analysis (including, without limitation, benchmarks) from any source relating to the Software; (i) utilize any equipment, device, software, or other means designed to circumvent or remove any form of Source URL or copy protection used by Contributed Systems in connection with the Software, or use the Software together with any authorization code, Source URL, serial number, or other copy protection device not supplied by Contributed Systems; (j) use the Software to develop a product which is competitive with any Contributed Systems product offerings; or (k) use unauthorized Source URLS or keycode(s) or distribute or publish Source URLs or keycode(s), except as may be expressly permitted by Contributed Systems in writing. If your unique Source URL is ever published, Contributed Systems reserves the right to terminate your access without notice.
+
+3.2 UNDER NO CIRCUMSTANCES MAY YOU USE THE SOFTWARE AS PART OF A PRODUCT OR SERVICE THAT PROVIDES SIMILAR FUNCTIONALITY TO THE SOFTWARE ITSELF.
+
+The Open Source version of the Software (“LGPL Version”) is licensed
+under the terms of the GNU Lesser General Public License versions 3.0
+(“LGPL”) and not under this EULA. 
+
+4. Ownership. Notwithstanding anything to the contrary contained herein, except for the limited license rights expressly provided herein, Contributed Systems and its suppliers have and will retain all rights, title and interest (including, without limitation, all patent, copyright, trademark, trade secret and other intellectual property rights) in and to the Software and all copies, modifications and derivative works thereof (including any changes which incorporate any of your ideas, feedback or suggestions). You acknowledge that you are obtaining only a limited license right to the Software, and that irrespective of any use of the words “purchase”, “sale” or like terms hereunder no ownership rights are being conveyed to you under this Agreement or otherwise. 
+
+5. Fees and Payment. The Software license fees will be due and payable in full as set forth in the applicable invoice or at the time of purchase. If the Software does not function properly within two weeks of purchase, please contact us within those two weeks for a refund. You shall be responsible for all taxes, withholdings, duties and levies arising from the order (excluding taxes based on the net income of Contributed Systems). 
+
+6. Support, Maintenance and Services. Subject to the terms and conditions of this Agreement, as set forth in your invoice, and as set forth on the Gor Pro support page (https://github.com/buger/gor/wiki/Pro-Support), support and maintenance services may be included with the purchase of your license subscription.
+
+7. Term of Agreement. 
+
+7.1 Term. This Agreement is effective as of the Delivery of the Software and expires at such time as all license and service subscriptions hereunder have expired in accordance with their own terms (the “Term”). For clarification, the term of your license under this Agreement may be perpetual, limited for Evaluation Version, or designated as a fixed-term license in the Invoice, and shall be specified at your time of purchase. Either party may terminate this Agreement (including all related Invoices) if the other party: (a) fails to cure any material breach of this Agreement within thirty (30) days after written notice of such breach, provided that Contributed Systems may terminate this Agreement immediately upon any breach of Section 3 or if you exceed any other restrictions contained in Section 1, unless otherwise specified in this agreement; (b) ceases operation without a successor; or (c) seeks protection under any bankruptcy, receivership, trust deed, creditors arrangement, composition or comparable proceeding, or if any such proceeding is instituted against such party (and not dismissed within sixty (60) days)). Termination is not an exclusive remedy and the exercise by either party of any remedy under this Agreement will be without prejudice to any other remedies it may have under this Agreement, by law, or otherwise.        
+
+7.2 Termination. Upon any termination of this Agreement, you shall cease any and all use of any Software and destroy all copies thereof. 
+
+7.3 Expiration of License. Upon the expiration of any term under this Agreement, (a) all Software updates and services pursuant to the license shall cease, (b) you may only continue to run existing installations of the Software, (c) you may not install the Software on any additional Hosts, and (d) any new installation of the Software shall require the purchase of a new license subscription from Contributed Systems.
+
+8. Disclaimer of Warranties. The Software is provided "as is," with all faults, defects and errors, and without warranty of any kind. Contributed Systems does not warrant that the Software will be free of bugs, errors, viruses or other defects, and Contributed Systems shall have no liability of any kind for the use of or inability to use the Software, the Software content or any associated service, and you acknowledge that it is not technically practicable for Contributed Systems to do so. 
+To the maximum extent permitted by applicable law, Contributed Systems disclaims all warranties, express, implied, arising by law or otherwise, regarding the Software, the Software content and their respective performance or suitability for your intended use, including without limitation any implied warranty of merchantability, fitness for a particular purpose.
+
+9. Limitation of Liability. 
+
+In no event will Contributed Systems be liable for any direct, indirect, consequential, incidental, special, exemplary, or punitive damages or liabilities whatsoever arising from or relating to the Software, the Software content or this Agreement, whether based on contract, tort (including negligence), strict liability or other theory, even if Contributed Systems has been advised of the possibility of such damages.
+
+In no event will Contributed Systems' liability exceed the Software license price as indicated in the invoice. The existence of more than one claim will not enlarge or extend this limit.
+
+10. Remedies. Your exclusive remedy and Contributed Systems’ entire liability for breach of this Agreement shall be limited, at Contributed Systems’ sole and exclusive discretion, to (a) replacement of any defective software or documentation; or (b) refund of the license fee paid to Contributed Systems, payable in accordance with Contributed Systems' refund policy.
+
+11. Acknowledgements.
+
+11.1 Consent to the Use of Data. You agree that Contributed Systems and its affiliates may collect and use technical information gathered as part of the product support services. Contributed Systems may use this information solely to improve products and services and will not disclose this information in a form that personally identifies you.
+
+11.2 Verification. We or a certified auditor acting on our behalf, may, upon its reasonable request and at its expense, audit you with respect to the use of the Software. Such audit may be conducted by mail, electronic means or through an in-person visit to your place of business. Any such in-person audit shall be conducted during regular business hours at your facilities and shall not unreasonably interfere with your business activities. We shall not remove, copy, or redistribute any electronic material during the course of an audit. If an audit reveals that you are using the Software in a way that is in material violation of the terms of the EULA, then you shall pay our reasonable costs of conducting the audit. In the case of a material violation, you agree to pay Us any amounts owing that are attributable to the unauthorized use. In the alternative, We reserve the right, at our sole option, to terminate the licenses for the Software.
+
+11.3 Government End Users. If the Software and related documentation are supplied to or purchased by or on behalf of the United States Government, then the Software is deemed to be "commercial software" as that term is used in the Federal Acquisition Regulation system. Rights of the United States shall not exceed the minimum rights set forth in FAR 52.227-19 for "restricted computer software". All other terms and conditions of this Agreement apply.
+
+12. Third Party Software.  Examples included in Software may provide links to third party libraries or code (collectively “Third Party Software”) to implement various functions. Third Party Software does not comprise part of the Software. In some cases, access to Third Party Software may be included along with the Software delivery as a convenience for demonstration purposes. Such source code and libraries may be included in the “…/examples” source tree delivered with the Software and do not comprise the Software. Licensee acknowledges (1) that some part of Third Party Software may require additional licensing of copyright and patents from the owners of such, and (2) that distribution of any of the Software referencing or including any portion of a Third Party Software may require appropriate licensing from such third parties.
+
+
+13. Miscellaneous
+
+13.1 Entire Agreement. This Agreement sets forth our entire agreement with respect to the Software and the subject matter hereof and supersedes all prior and contemporaneous understandings and agreements whether written or oral.
+
+13.2 Amendment. Contributed Systems reserves the right, in its sole discretion, to amend this Agreement from time. Amendments to this Agreement can be located at: https://github.com/buger/gor/blob/master/COMM-LICENSE.
+
+13.3 Assignment. You may not assign this Agreement or any of its rights under this Agreement without the prior written consent of Contributed Systems and any attempted assignment without such consent shall be void.
+
+13.4 Export Compliance. You agree to comply with all applicable laws and regulations, including laws, regulations, orders or other restrictions on export, re-export or redistribution of software.
+
+13.5 Indemnification. You agree to defend, indemnify, and hold harmless Contributed Systems from and against any lawsuits, claims, losses, damages, fines and expenses (including attorneys' fees and costs) arising out of your use of the Software or breach of this Agreement.
+
+13.6 Governing Law. This Agreement is governed by the laws of the State of Oregon and the United States without regard to conflicts of laws provisions thereof, and without regard to the United Nations Convention on the International Sale of Goods or the Uniform Computer Information Transactions Act, as currently enacted by any jurisdiction or as may be codified or amended from time to time by any jurisdiction. The jurisdiction and venue for actions related to the subject matter hereof shall be the state of Oregon and United States federal courts located in Portland, Oregon, and both parties hereby submit to the personal jurisdiction of such courts. 
+
+13.7 Attorneys’ Fees and Costs. The prevailing party in any action to enforce this Agreement will be entitled to recover its attorneys’ fees and costs in connection with such action. 
+
+13.8 Severability. If any provision of this Agreement is held by a court of competent jurisdiction to be invalid, illegal, or unenforceable, the remainder of this Agreement will remain in full force and effect.
+
+13.9 Waiver. Failure or neglect by either party to enforce at any time any of the provisions of this licence Agreement shall not be construed or deemed to be a waiver of that party's rights under this Agreement.
+
+13.10 Headings. The headings of sections and paragraphs of this Agreement are for convenience of reference only and are not intended to restrict, affect or be of any weight in the interpretation or construction of the provisions of such sections or paragraphs.
+
+14. Contact Information. If you have any questions about this EULA, or if you want to contact Contributed Systems for any reason, please direct correspondence to leonsbox@gmail.com

Dockerfile

@@ -0,0 +1,24 @@
+FROM golang:latest
+
+RUN apt-get update && apt-get install ruby vim-common -y
+
+# Install Java for middleware testing
+RUN echo "deb http://ppa.launchpad.net/webupd8team/java/ubuntu trusty main" | tee /etc/apt/sources.list.d/webupd8team-java.list
+RUN echo "deb-src http://ppa.launchpad.net/webupd8team/java/ubuntu trusty main" | tee -a /etc/apt/sources.list.d/webupd8team-java.list
+RUN apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys EEA14886
+RUN apt-get update -y
+RUN echo oracle-java7-installer shared/accepted-oracle-license-v1-1 select true | /usr/bin/debconf-set-selections
+RUN apt-get install oracle-java8-installer -y
+
+RUN wget http://apache-mirror.rbc.ru/pub/apache//commons/io/binaries/commons-io-2.4-bin.tar.gz -P /tmp
+RUN tar xzf /tmp/commons-io-2.4-bin.tar.gz -C /tmp
+
+RUN apt-get install libpcap-dev -y
+RUN go get github.com/google/gopacket
+RUN go get -u github.com/golang/lint/golint
+
+WORKDIR /go/src/github.com/buger/gor/
+ADD . /go/src/github.com/buger/gor/
+
+RUN javac -cp /tmp/commons-io-2.4/commons-io-2.4.jar ./examples/middleware/echo.java
+RUN go get

LICENSE.txt

@@ -1,191 +1,7 @@
-Apache License
-Version 2.0, January 2004
-http://www.apache.org/licenses/
+Gor is an Open Source project licensed under the terms of
+the LGPLv3 license.  Please see <http://www.gnu.org/licenses/lgpl-3.0.html>
+for license text.
 
-TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
-
-1. Definitions.
-
-"License" shall mean the terms and conditions for use, reproduction, and
-distribution as defined by Sections 1 through 9 of this document.
-
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-owner that is granting the License.
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-indirect, to cause the direction or management of such entity, whether by
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-outstanding shares, or (iii) beneficial ownership of such entity.
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-files.
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-for inclusion in the Work by You to the Licensor shall be under the terms and
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-Unless required by applicable law or agreed to in writing, Licensor provides the
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-permissions under this License.
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-
-In no event and under no legal theory, whether in tort (including negligence),
-contract, or otherwise, unless required by applicable law (such as deliberate
-and grossly negligent acts) or agreed to in writing, shall any Contributor be
-liable to You for damages, including any direct, indirect, special, incidental,
-or consequential damages of any character arising as a result of this License or
-out of the use or inability to use the Work (including but not limited to
-damages for loss of goodwill, work stoppage, computer failure or malfunction, or
-any and all other commercial damages or losses), even if such Contributor has
-been advised of the possibility of such damages.
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-9. Accepting Warranty or Additional Liability.
-
-While redistributing the Work or Derivative Works thereof, You may choose to
-offer, and charge a fee for, acceptance of support, warranty, indemnity, or
-other liability obligations and/or rights consistent with this License. However,
-in accepting such obligations, You may act only on Your own behalf and on Your
-sole responsibility, not on behalf of any other Contributor, and only if You
-agree to indemnify, defend, and hold each Contributor harmless for any liability
-incurred by, or claims asserted against, such Contributor by reason of your
-accepting any such warranty or additional liability.
-
-END OF TERMS AND CONDITIONS
-
-APPENDIX: How to apply the Apache License to your work
-
-To apply the Apache License to your work, attach the following boilerplate
-notice, with the fields enclosed by brackets "[]" replaced with your own
-identifying information. (Don't include the brackets!) The text should be
-enclosed in the appropriate comment syntax for the file format. We also
-recommend that a file or class name and description of purpose be included on
-the same "printed page" as the copyright notice for easier identification within
-third-party archives.
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-   Copyright [yyyy] [name of copyright owner]
-
-   Licensed under the Apache License, Version 2.0 (the "License");
-   you may not use this file except in compliance with the License.
-   You may obtain a copy of the License at
-
-     http://www.apache.org/licenses/LICENSE-2.0
-
-   Unless required by applicable law or agreed to in writing, software
-   distributed under the License is distributed on an "AS IS" BASIS,
-   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-   See the License for the specific language governing permissions and
-   limitations under the License.
+Gor Pro has a commercial-friendly license allowing private forks
+and modifications of Gor.  Please see http://gortool.com/#pro for
+more detail.  You can find the commercial license terms in COMM-LICENSE.

Makefile

@@ -1,16 +1,68 @@
-all: build-macosx build-x86 build-x64
+SOURCE = emitter.go gor.go gor_stat.go input_dummy.go input_file.go input_raw.go input_tcp.go limiter.go output_dummy.go output_file.go input_http.go output_http.go output_tcp.go plugins.go settings.go test_input.go elasticsearch.go http_modifier.go http_modifier_settings.go http_client.go middleware.go protocol.go
+SOURCE_PATH = /go/src/github.com/buger/gor/
+RUN = docker run -v `pwd`:$(SOURCE_PATH) -p 0.0.0.0:8000:8000 -t -i gor
+BENCHMARK = BenchmarkRAWInput
 
-build-x64:
-    GOOS=linux GOARCH=amd64 CGO_ENABLED=0 go build
-    tar -czf gor_x64.tar.gz gor
-    rm gor
+release: release-x86 release-x64
 
-build-x86:
-    GOOS=linux GOARCH=386 CGO_ENABLED=0 go build
-    tar -czf gor_x86.tar.gz gor
-    rm gor
+release-x64:
+	docker run -v `pwd`:$(SOURCE_PATH) -t --env GOOS=linux --env GOARCH=amd64 --env CGO_ENABLED=0 -i gor go build -ldflags "-X main.VERSION=$(VERSION)"&& tar -czf gor_$(VERSION)_x64.tar.gz gor && rm gor
 
-build-macosx:
-    GOOS=darwin GOARCH=amd64 CGO_ENABLED=0 go build
-    tar -czf gor_macosx.tar.gz gor
-    rm gor
+release-x86:
+	docker run -v `pwd`:$(SOURCE_PATH) -t --env GOOS=linux --env GOARCH=386 --env CGO_ENABLED=0 -i gor go build -ldflags "-X main.VERSION=$(VERSION)" && tar -czf gor_$(VERSION)_x86.tar.gz gor && rm gor
+
+build:
+	docker build -t gor .
+
+
+profile:
+	go build && ./gor --output-http="http://localhost:9000" --input-dummy 0 --input-raw :9000 --input-http :9000 --memprofile=./mem.out --cpuprofile=./cpu.out --stats --output-http-stats --output-http-timeout 100ms
+
+lint:
+	$(RUN) golint $(PKG)
+
+race:
+	$(RUN) go test ./... $(ARGS) -v -race -timeout 15s
+
+test:
+	$(RUN) go test ./. -timeout 30s $(ARGS) -v
+
+test_all:
+	$(RUN) go test ./... -timeout 30s $(ARGS) -v
+
+testone:
+	$(RUN) go test ./... -timeout 4s -run $(TEST) $(ARGS) -v
+
+cover:
+	$(RUN) go test $(ARGS) -race -v -timeout 15s -coverprofile=coverage.out
+	go tool cover -html=coverage.out
+
+fmt:
+	$(RUN) gofmt -w -s ./..
+
+vet:
+	$(RUN) go vet
+
+bench:
+	$(RUN) go test -v -run NOT_EXISTING -bench $(BENCHMARK) -benchtime 5s
+
+profile_test:
+	$(RUN) go test $(LDFLAGS) -run NOT_EXISTING -test.benchmem -bench $(BENCHMARK) ./. $(ARGS) -benchtime 5s -memprofile mem.mprof -v
+	$(RUN) go test $(LDFLAGS) -run NOT_EXISTING -test.benchmem -bench $(BENCHMARK) ./. $(ARGS) -benchtime 5s -cpuprofile cpu.out -v
+	$(RUN) go test $(LDFLAGS) -run NOT_EXISTING -test.benchmem -bench $(BENCHMARK) ./. $(ARGS) -c
+
+# Used mainly for debugging, because docker container do not have access to parent machine ports
+run:
+	$(RUN) go run $(SOURCE) --input-dummy=0 --output-http="http://localhost:9000" --input-raw :9000 --input-http :9000 --verbose --debug --middleware "./examples/middleware/echo.sh"
+
+run-2:
+	$(RUN) go run $(SOURCE) --input-file ./fixtures/requests.gor --output-dummy=0
+
+record:
+	$(RUN) go run $(SOURCE) --input-dummy=0 --output-file=requests.gor --verbose --debug
+
+replay:
+	$(RUN) go run $(SOURCE) --input-file=requests.bin --output-tcp=:9000 --verbose -h
+
+bash:
+	$(RUN) /bin/bash

README.md

@@ -1,228 +1,497 @@
-[![Stories in Ready](https://badge.waffle.io/buger/gor.png?label=ready)](https://waffle.io/buger/gor)  
-[![Build Status](https://travis-ci.org/buger/gor.png?branch=master)](https://travis-ci.org/buger/gor)
-
-## About
-
-Gor is a simple http traffic replication tool written in Go.
-Its main goal is to replay traffic from production servers to staging and dev environments.
-
-
-Now you can test your code on real user sessions in an automated and repeatable fashion.
-**No more falling down in production!**
-
-Here is basic worlkflow: The listener server catches http traffic and sends it to the replay server or saves to file.The replay server forwards traffic to a given address.
-
-
-![Diagram](http://i.imgur.com/9mqj2SK.png)
-
-
-## Examples
-
-### Capture traffic from port
-```bash
-# Run on servers where you want to catch traffic. You can run it on each `web` machine.
-sudo gor --input-raw :80 --output-tcp replay.local:28020
-
-# Replay server (replay.local).
-gor --input-tcp replay.local:28020 --output-http http://staging.com
-```
-
-### Using 1 Gor instance for both listening and replaying
-It's recommended to use separate server for replaying traffic, but if you have enough CPU resources you can use single Gor instance.
-
-```
-sudo gor --input-raw :80 --output-http "http://staging.com"
-```
-
-## Advanced use
-
-### Rate limiting
-Both replay and listener support rate limiting. It can be useful if you want
-forward only part of production traffic and not overload your staging
-environment. You can specify your desired requests per second using the
-"|" operator after the server address:
-
-#### Limiting replay
-```
-# staging.server will not get more than 10 requests per second
-gor --input-tcp :28020 --output-http "http://staging.com|10"
-```
-
-#### Limiting listener
-```
-# replay server will not get more than 10 requests per second
-# useful for high-load environments
-gor --input-raw :80 --output-tcp "replay.local:28020|10"
-```
-
-### Forward to multiple addresses
-
-You can forward traffic to multiple endpoints. Just add multiple --output-* arguments.
-```
-gor --input-tcp :28020 --output-http "http://staging.com"  --output-http "http://dev.com"
-```
-
-#### Splitting traffic
-By default it will send same traffic to all outputs, but you have options to equally split it:
-
-```
-gor --input-tcp :28020 --output-http "http://staging.com"  --output-http "http://dev.com" --split-output true
-```
-
-### Saving requests to file
-You can save requests to file, and replay them later:
-```
-# write to file
-gor --input-raw :80 --output-file requests.gor
-
-# read from file
-gor --input-file requests.gor --output-http "http://staging.com"
-```
-
-**Note:** Replay will preserve the original time differences between requests.
-
-### Injecting headers
-
-Additional headers can be injected/overwritten into requests during replay. This may be useful if the hostname that staging responds to differs from production, you need to identify requests generated by Gor, or enable feature flagged functionality in an application:
-
-```
-gor --input-raw :80 --output-http "http://staging.server" \
-    --output-http-header "Host: staging.server" \
-    --output-http-header "User-Agent: Replayed by Gor" -header " \
-    --output-http-header "Enable-Feature-X: true"
-```
-
-## Filtering HTTP methods
+[![GitHub release](https://img.shields.io/github/release/buger/gor.svg?maxAge=2592000)]() [![Build Status](https://travis-ci.org/buger/gor.png?branch=master)](https://travis-ci.org/buger/gor) [![codebeat](https://codebeat.co/badges/6427d589-a78e-416c-a546-d299b4089893)](https://codebeat.co/projects/github-com-buger-gor) [![Go Report Card](https://goreportcard.com/badge/github.com/buger/gor)](https://goreportcard.com/report/github.com/buger/gor) [![Join the chat at https://gitter.im/buger/gor](https://badges.gitter.im/buger/gor.svg)](https://gitter.im/buger/gor?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 
+## About
+
+Gor is an open-source tool for capturing and replaying live HTTP traffic into a test environment in order to continuously test your system with real data. It can be used to increase confidence in code deployments, configuration changes and infrastructure changes.
+
+
+Now you can test your code on real user sessions in an automated and repeatable fashion.
+**No more falling down in production!**
+
+Here is basic workflow: The listener server catches http traffic and sends it to the replay server or saves to file. The replay server forwards traffic to a given address.
+
+
+![Diagram](http://i.imgur.com/9mqj2SK.png)
+
+
+## Want to Upgrade?
+
+I also sell Gor Pro, extensions to Gor which provide more features, a commercial-friendly license and allow you to support high quality open source development all at the same time. Please see the Gor [homepage](https://gortool.com/) for more detail.
+
+Subscribe to the [quarterly newsletter](https://tinyletter.com/gor) to stay informed about the latest features and changes to Gor and its bigger siblings.
+
+
+## Examples
+
+### Capture traffic from port
+```bash
+# Run on servers where you want to catch traffic. You can run it on each `web` machine.
+sudo gor --input-raw :80 --output-tcp replay.local:28020
+
+# Replay server (replay.local).
+gor --input-tcp replay.local:28020 --output-http http://staging.com
+```
+
+Since Gor use raw sockets to capture traffic it require `sudo` access. Alternatively you can allow access to raw sockets like this: `sudo setcap CAP_NET_RAW=ep gor`
+
+### Using 1 Gor instance for both listening and replaying
+It's recommended to use separate server for replaying traffic, but if you have enough CPU resources you can use single Gor instance.
+
+```
+sudo gor --input-raw :80 --output-http "http://staging.com"
+```
+
+## Configuration
+
+### Forward to multiple addresses
+
+You can forward traffic to multiple endpoints. Just add multiple --output-* arguments.
+```
+gor --input-tcp :28020 --output-http "http://staging.com"  --output-http "http://dev.com"
+```
+
+#### Splitting traffic
+By default it will send same traffic to all outputs, but you have options to equally split it:
+
+```
+gor --input-tcp :28020 --output-http "http://staging.com"  --output-http "http://dev.com" --split-output true
+```
+
+### HTTP output workers
+By default Gor creates a dynamic pool of workers: it starts with 10 and creates more http output workers when the http output queue length is greater than 10.  The number of workers created (N) is equal to the queue length at the time which it is checked and found to have a length greater than 10. The queue length is checked every time a message is written to the http output queue.  No more workers will be spawned until that request to spawn N workers is satisfied.  If a dynamic worker cannot process a message at that time, it will sleep for 100 milliseconds. If a dynamic worker cannot process a message for 2 seconds it dies.
+You may specify fixed number of workers using  `--output-http-workers=20` option.
+
+### Follow redirects
+By default Gor will ignore all redirects since they are handled by clients using your app, but in scenarios where your replayed environment introduces new redirects, you can enable them like this: 
+```
+gor --input-tcp replay.local:28020 --output-http http://staging.com --output-http-redirects 2
+```
+The given example will follow up to 2 redirects per request.
+
+### HTTP timeouts
+By default http timeout for both request and response is 5 seconds. You can override it like this:
+```
+gor --input-tcp replay.local:28020 --output-http http://staging.com --output-http-timeout 30s
+```
+
+### Rate limiting
+Rate limiting can be useful if you only want to forward parts of production traffic and not overload your staging environment. There are 2 strategies: dropping random requests or dropping fractions of requests based on Header or URL param value. 
+
+#### Dropping random requests
+Every input and output supports random rate limiting.
+There are 2 limiting algorithms: absolute or percentage based. 
+
+Absolute: If for current second it reached specified requests limit - disregard the rest, on next second counter reseted.
+
+Percentage: For input-file it will slowdown or speedup request execution, for the rest it will use random generator to decide if request pass or not based on chance you specified. 
+
+You can specify your desired limit using the
+"|" operator after the server address:
+
+#### Limiting replay using absolute number
+```
+# staging.server will not get more than 10 requests per second
+gor --input-tcp :28020 --output-http "http://staging.com|10"
+```
+
+#### Limiting listener using percentage based limiter
+```
+# replay server will not get more than 10% of requests 
+# useful for high-load environments
+gor --input-raw :80 --output-tcp "replay.local:28020|10%"
+```
+
+#### Limiting based on Header or URL param value
+If you have unique user id (like API key) stored in header or URL you can consistently forward specified percent of traffic only for fraction of this users. 
+Basic formula looks like this: `FNV32-1A_hashing(value) % 100 >= chance`. Examples:
+```
+# Limit based on header value
+gor --input-raw :80 --output-tcp "replay.local:28020|10%" --http-header-limiter "X-API-KEY: 10%"
+
+# Limit based on header value
+gor --input-raw :80 --output-tcp "replay.local:28020|10%" --http-param-limiter "api_key: 10%"
+```
+Only percentage based limiting supported.
+
+### Filtering 
+
+#### Allow url regexp
+```
+# only forward requests being sent to the /api endpoint
+gor --input-raw :8080 --output-http staging.com --http-allow-url /api
+```
+
+#### Disallow url regexp
+```
+# only forward requests NOT being sent to the /api... endpoint
+gor --input-raw :8080 --output-http staging.com --http-disallow-url /api
+```
+#### Filter based on regexp of header
+
+```
+# only forward requests with an api version of 1.0x
+gor --input-raw :8080 --output-http staging.com --http-allow-header api-version:^1\.0\d
+
+# only forward requests NOT containing User-Agent header value "Replayed by Gor"
+gor --input-raw :8080 --output-http staging.com --http-disallow-header "User-Agent: Replayed by Gor"
+```
+
+#### Filter based on http method
 Requests not matching a specified whitelist can be filtered out. For example to strip non-nullipotent requests:
 
 ```
 gor --input-raw :80 --output-http "http://staging.server" \
-    --output-http-method GET \
-    --output-http-method OPTIONS
+    --http-allow-method GET \
+    --http-allow-method OPTIONS
 ```
 
-### Basic Auth
-
-If your development or staging environment is protected by Basic Authentication then those credentials can be injected in during the replay:
-
-```
-gor --input-raw :80 --output-http "http://user:pass@staging .com"
-```
-
-Note: This will overwrite any Authorization headers in the original request.
-
-## Stats 
-### ElasticSearch 
-For deep response analyze based on url, cookie, user-agent and etc. you can export response metadata to ElasticSearch. See [ELASTICSEARCH.md](ELASTICSEARCH.md) for more details.
-
-```
-gor --input-tcp :80 --output-http "http://staging.com" --output-http-elasticsearch "es_host:api_port/index_name"
-```
-
-
-## Additional help
-
-Feel free to ask question directly by email or by creating github issue.
-
-## Latest releases (including binaries)
-
-https://github.com/buger/gor/releases
-
-## Command line reference
-`gor -h` output:
-```
-  -cpuprofile="": write cpu profile to file
-  -memprofile="": write memory profile to this file
-  
-  -input-dummy=[]: Used for testing outputs. Emits 'Get /' request every 1s
-
-  -input-file=[]: Read requests from file: 
-    gor --input-file ./requests.gor --output-http staging.com
-
-  -input-raw=[]: Capture traffic from given port (use RAW sockets and require *sudo* access):
-    # Capture traffic from 8080 port
-    gor --input-raw :8080 --output-http staging.com
-
-  -input-tcp=[]: Used for internal communication between Gor instances. Example: 
-    # Receive requests from other Gor instances on 28020 port, and redirect output to staging
-    gor --input-tcp :28020 --output-http staging.com
-
-  -output-dummy=[]: Used for testing inputs. Just prints data coming from inputs.
-
-  -output-file=[]: Write incoming requests to file: 
-    gor --input-raw :80 --output-file ./requests.gor
-
-  -output-http=[]: Forwards incoming requests to given http address.
-    # Redirect all incoming requests to staging.com address 
-    gor --input-raw :80 --output-http http://staging.com
-
-  -output-http-elasticsearch="": Send request and response stats to ElasticSearch:
-    gor --input-raw :8080 --output-http staging.com --output-http-elasticsearch 'es_host:api_port/index_name'
-
-  -output-http-header=[]: Inject additional headers to http reqest:
-    gor --input-raw :8080 --output-http staging.com --output-http-header 'User-Agent: Gor'
-    
-  -output-tcp=[]: Used for internal communication between Gor instances. Example: 
-    # Listen for requests on 80 port and forward them to other Gor instance on 28020 port
-    gor --input-raw :80 --output-tcp replay.local:28020
-    
-  -split-output=false: By default each output gets same traffic. If set to `true` it splits traffic equally among all outputs.
-```
-
-## Building from source
-1. Setup standard Go environment http://golang.org/doc/code.html and ensure that $GOPATH environment variable properly set.
-2. `go get github.com/buger/gor`.
-3. `cd $GOPATH/src/github.com/buger/gor`
-4. `go build ./bin/gor.go` to get binary, or `go run ./bin/gor.go` to build and run (useful for development)
-
-## FAQ
-
-### What OS are supported?
-For now only Linux based. *BSD (including MacOS is not supported yet, check https://github.com/buger/gor/issues/22 for details)
-
-### Why does the `--input-raw` requires sudo or root access?
-Listener works by sniffing traffic from a given port. It's accessible
-only by using sudo or root access.
-
-### I'm getting 'too many open files' error
-Typical linux shell has a small open files soft limit at 1024. You can easily raise that when you do this before starting your gor replay process:
-  
-  ulimit -n 64000
-
-More about ulimit: http://blog.thecodingmachine.com/content/solving-too-many-open-files-exception-red5-or-any-other-application
-
-## Tuning
-
-To achieve the top most performance you should tune the source server system limits:
-
-    net.ipv4.tcp_max_tw_buckets = 65536
-    net.ipv4.tcp_tw_recycle = 1
-    net.ipv4.tcp_tw_reuse = 0
-    net.ipv4.tcp_max_syn_backlog = 131072
-    net.ipv4.tcp_syn_retries = 3
-    net.ipv4.tcp_synack_retries = 3
-    net.ipv4.tcp_retries1 = 3
-    net.ipv4.tcp_retries2 = 8
-    net.ipv4.tcp_rmem = 16384 174760 349520
-    net.ipv4.tcp_wmem = 16384 131072 262144
-    net.ipv4.tcp_mem = 262144 524288 1048576
-    net.ipv4.tcp_max_orphans = 65536
-    net.ipv4.tcp_fin_timeout = 10
-    net.ipv4.tcp_low_latency = 1
-    net.ipv4.tcp_syncookies = 0
-
-
-## Contributing
-
-1. Fork it
-2. Create your feature branch (git checkout -b my-new-feature)
-3. Commit your changes (git commit -am 'Added some feature')
-4. Push to the branch (git push origin my-new-feature)
-5. Create new Pull Request
-
-## Companies using Gor
-
-* http://granify.com
-* [GOV.UK](https://www.gov.uk) ([Government Digital Service](http://digital.cabinetoffice.gov.uk/))
-* To add your company drop me a line to github.com/buger or leonsbox@gmail.com
+### Rewriting original request
+Gor supports some basic request rewriting support. For complex logic you can use middleware, see below.
+
+#### Rewrite URL based on a mapping
+```
+# rewrite url to match the following
+gor --input-raw :8080 --output-http staging.com --http-rewrite-url /v1/user/([^\\/]+)/ping:/v2/user/$1/ping
+```
+
+#### Set URL param
+Set request url param, if param already exists it will be overwritten
+```
+gor --input-raw :8080 --output-http staging.com --http-set-param api_key=1
+```
+
+#### Set Header
+Set request header, if header already exists it will be overwritten. This may be useful if you need to identify requests generated by Gor or enable feature flagged functionality in an application:
+
+```
+gor --input-raw :80 --output-http "http://staging.server" \
+    --http-header "User-Agent: Replayed by Gor" \
+    --http-header "Enable-Feature-X: true"
+```
+
+#### Host header
+Host header gets special treatment. By default Host get set to the value specified in --output-http. If you manually set --http-header "Host: anonther.com", Gor will not override Host value.
+
+If you app accepts traffic from multiple domain, and you want to keep original headers, there is specific `--http-original-host` with tells Gor do not touch Host header at all.
+
+### Middleware
+Middleware is a program that accepts request and response payload at STDIN and emits modified requests at STDOUT. You can implement any custom logic like stripping private data, advanced rewriting, support for oAuth and etc.
+
+```
+                   Original request      +--------------+
++-------------+----------STDIN---------->+              |
+|  Gor input  |                          |  Middleware  |
++-------------+----------STDIN---------->+              |
+                   Original response     +------+---+---+
+                                                |   ^
++-------------+    Modified request             v   |
+| Gor output  +<---------STDOUT-----------------+   |
++-----+-------+                                     |
+      |                                             |
+      |            Replayed response                |
+      +------------------STDIN----------------->----+
+```
+
+Middleware can be written in any language, see `examples/middleware` folder for examples.
+Middleware program should accept the fact that all communication with Gor is asynchronous, there is no guarantee that original request and response messages will come one after each other. Your app should take care of the state if logic depends on original or replayed response, see `examples/middleware/token_modifier.go` as example.
+
+Simple bash echo middleware (returns same request) will look like this:
+```bash
+while read line; do
+  echo $line
+end
+```
+
+Middleware can be enabled using `--middleware` option, by specifying path to executable file:
+```
+gor --input-raw :80 --middleware "/opt/middleware_executable" --output-http "http://staging.server"
+```
+
+#### Communication protocol
+All messages should be hex encoded, new line character specifieds the end of the message, eg. new message per line.
+
+Decoded payload consist of 2 parts: header and HTTP payload, separated by new line character.  
+
+Example request payload:
+
+```
+1 932079936fa4306fc308d67588178d17d823647c 1439818823587396305
+GET /a HTTP/1.1
+Host: 127.0.0.1
+
+```
+
+Example response payload:
+
+```
+2 8e091765ae902fef8a2b7d9dd960e9d52222bd8c 2782013
+HTTP/1.1 200 OK
+Date: Mon, 17 Aug 2015 13:40:23 GMT
+Content-Length: 0
+Content-Type: text/plain; charset=utf-8
+
+```
+
+Header contains request meta information separated by spaces. First value is payload type, possible values: `1` - request, `2` - original response, `3` - replayed response.
+Next goes request id: unique among all requests (sha1 of time and Ack), but remain same for original and replayed response, so you can create associations between request and responses. Third argument varies depending on payload type: for request - start time, for responses - round-trip time.
+
+HTTP payload is unmodified HTTP requests/responses intercepted from network. You can read more about request format [here](http://www.jmarshall.com/easy/http/), [here](https://en.wikipedia.org/wiki/Hypertext_Transfer_Protocol) and [here](http://www.w3.org/Protocols/rfc2616/rfc2616.html). You can operate with payload as you want, add headers, change path, and etc. Basically you just editing a string, just ensure that it is RCF compliant.
+
+At the end modified (or untouched) request should be emitted back to STDOUT, keeping original header, and hex-encoded. If you want to filter request, just not send it. Emitting responses back is required, even if you did not touch them.
+
+#### Advanced example
+Imagine that you have auth system that randomly generate access tokens, which used later for accessing secure content. Since there is no pre-defined token value, naive approach without middleware (or if middleware use only request payloads) will fail, because replayed server have own tokens, not synced with origin. To fix this, our middleware should take in account responses of replayed and origin server, store `originalToken -> replayedToken` aliases and rewrite all requests using this token to use replayed alias. See `examples/middleware/token_modifier.go` and `middleware_test.go#TestTokenMiddleware` as example of described scheme.
+
+### Saving requests to file and replaying them
+You can save requests to file, and replay them later:
+```
+# write to file
+gor --input-raw :80 --output-file requests.gor
+
+# read from file
+gor --input-file requests.gor --output-http "http://staging.com"
+```
+
+**Note:** Replay will preserve the original time differences between requests.
+
+### Load testing
+
+Currently it supported only by `input-file` and only when using percentage based limiter. Unlike default limiter for `input-file` instead of dropping requests it will slowdown or speedup request emitting. Note that unlike examples above limiter is applied to input:
+
+```
+# Replay from file on 2x speed 
+gor --input-file "requests.gor|200%" --output-http "staging.com"
+```
+
+### Basic Auth
+
+If your development or staging environment is protected by Basic Authentication then those credentials can be injected in during the replay:
+
+```
+gor --input-raw :80 --output-http "http://user:pass@staging .com"
+```
+
+Note: This will overwrite any Authorization headers in the original request.
+
+### Traffic interception engine
+By default Gor use `libpcap` for intercepting traffic. If you have any troubles with it, you may try alternative engine: `raw_socket`.
+
+```
+sudo gor --input-raw :80 --input-raw-engine "libpcap" --output-http "http://staging.com"
+```
+
+
+## Stats 
+
+Gor can report stats on the `output-tcp` and `output-http` request queues. Stats are reported to the console every 5 seconds in the form `latest,mean,max,count,count/second` by using the `--output-http-stats` and `--output-tcp-stats` options.
+
+Examples:
+
+```
+2014/04/23 21:17:50 output_tcp:latest,mean,max,count,count/second
+2014/04/23 21:17:50 output_tcp:0,0,0,0,0
+2014/04/23 21:17:55 output_tcp:1,1,2,68,13
+2014/04/23 21:18:00 output_tcp:1,1,2,92,18
+2014/04/23 21:18:05 output_tcp:1,1,2,119,23
+```
+
+```
+Version: 0.8
+2014/04/23 21:19:46 output_http:latest,mean,max,count,count/second
+2014/04/23 21:19:46 output_http:0,0,0,0,0
+2014/04/23 21:19:51 output_http:0,0,0,0,0
+2014/04/23 21:19:56 output_http:0,0,0,0,0
+2014/04/23 21:20:01 output_http:1,0,1,50,10
+2014/04/23 21:20:06 output_http:1,1,4,72,14
+2014/04/23 21:20:11 output_http:1,0,1,179,35
+2014/04/23 21:20:16 output_http:1,0,1,148,29
+2014/04/23 21:20:21 output_http:1,1,2,91,18
+2014/04/23 21:20:26 output_http:1,1,2,150,30
+2014/04/23 21:18:15 output_http:100,99,100,70,14
+2014/04/23 21:18:21 output_http:100,99,100,55,11
+```
+
+### How can I tell if I have bottlenecks?
+Key areas that sometimes experience bottlenecks are the output-tcp and output-http functions which have internal queues for requests. Each queue has an upper limit of 100. Enable stats reporting to see if any queues are experiencing bottleneck behavior.
+ 
+#### output-http bottlenecks
+When running a Gor replay the output-http feature may bottleneck if:
+
+  * the replay has inadequate bandwidth. If the replay is receiving or sending more messages than its network adapter can handle the output-http-stats  may report that the output-http queue is filling up. See if there is a way to upgrade the replay's bandwidth.
+  * with `--output-http-workers` set to anything other than `-1` the `-output-http` target is unable to respond to messages in a timely manner. The http output workers which take messages off the output-http queue, process the request, and ensure that the request did not result in an error may not be able to keep up with the number of incoming requests. If the replay is not using dynamic worker scaling (`--output-http-workers=-1`)  The optimal number of output-http-workers can be determined with the formula `output-workers = (Average number of requests per second)/(Average target response time per second)`.
+
+#### output-tcp bottlenecks
+When using the Gor listener the output-tcp feature may bottleneck if:
+
+  * the replay is unable to accept and process more requests than the listener is able generate. Prior to troubleshooting the output-tcp bottleneck, ensure that the replay target is not experiencing any bottlenecks. 
+  * the replay target has inadequate bandwidth to handle all its incoming requests.  If a replay target's incoming bandwidth is maxed out the output-tcp-stats may report that the output-tcp queue is filling up. See if there is a way to upgrade the replay's bandwidth.
+
+### ElasticSearch 
+For deep response analyze based on url, cookie, user-agent and etc. you can export response metadata to ElasticSearch. See [ELASTICSEARCH.md](ELASTICSEARCH.md) for more details.
+
+```
+gor --input-tcp :80 --output-http "http://staging.com" --output-http-elasticsearch "es_host:api_port/index_name"
+```
+
+## Additional help
+
+Feel free to ask question directly by email or by creating github issue.
+
+## Latest releases (including binaries)
+
+https://github.com/buger/gor/releases
+
+## Command line reference
+`gor -h` output:
+```
+  -http-allow-header=[]: A regexp to match a specific header against. Requests with non-matching headers will be dropped:
+   gor --input-raw :8080 --output-http staging.com --http-allow-header api-version:^v1
+  -http-disallow-header=[]: A regexp to match a specific header against. Requests with matching headers will be dropped:
+   gor --input-raw :8080 --output-http staging.com --http-disallow-header "User-Agent: Replayed by Gor"
+  -http-allow-method=[]: Whitelist of HTTP methods to replay. Anything else will be dropped:
+  gor --input-raw :8080 --output-http staging.com --http-allow-method GET --http-allow-method OPTIONS
+  -http-allow-url=[]: A regexp to match requests against. Filter get matched agains full url with domain. Anything else will be dropped:
+   gor --input-raw :8080 --output-http staging.com --http-allow-url ^www.
+  -http-disallow-url=[]: A regexp to match requests against. Filter get matched agains full url with domain. Anything else will be forwarded:
+   gor --input-raw :8080 --output-http staging.com --http-disallow-url ^www.
+  -http-header-limiter=[]: Takes a fraction of requests, consistently taking or rejecting a request based on the FNV32-1A hash of a specific header:
+   gor --input-raw :8080 --output-http staging.com --http-header-imiter user-id:25%
+  -http-param-limiter=[]: Takes a fraction of requests, consistently taking or rejecting a request based on the FNV32-1A hash of a specific GET param:
+   gor --input-raw :8080 --output-http staging.com --http-param-limiter user_id:25%
+  -http-rewrite-url=[]: Rewrite the request url based on a mapping:
+  gor --input-raw :8080 --output-http staging.com --http-rewrite-url /v1/user/([^\/]+)/ping:/v2/user/$1/ping
+  -http-set-header=[]: Inject additional headers to http reqest:
+  gor --input-raw :8080 --output-http staging.com --http-set-header 'User-Agent: Gor'
+  -http-set-param=[]: Set request url param, if param already exists it will be overwritten:
+  gor --input-raw :8080 --output-http staging.com --http-set-param api_key=1
+  -input-dummy=[]: Used for testing outputs. Emits 'Get /' request every 1s
+  -input-file=[]: Read requests from file:
+  gor --input-file ./requests.gor --output-http staging.com
+  -input-http=[]: Read requests from HTTP, should be explicitly sent from your application:
+  # Listen for http on 9000
+  gor --input-http :9000 --output-http staging.com
+  -input-raw=[]: Capture traffic from given port (use RAW sockets and require *sudo* access):
+  # Capture traffic from 8080 port
+  gor --input-raw :8080 --output-http staging.com
+  -input-tcp=[]: Used for internal communication between Gor instances. Example:
+  # Receive requests from other Gor instances on 28020 port, and redirect output to staging
+  gor --input-tcp :28020 --output-http staging.com
+  -memprofile="": write memory profile to this file
+  -output-dummy=[]: Used for testing inputs. Just prints data coming from inputs.
+  -output-file=[]: Write incoming requests to file:
+  gor --input-raw :80 --output-file ./requests.gor
+  -output-http=[]: Forwards incoming requests to given http address.
+  # Redirect all incoming requests to staging.com address
+  gor --input-raw :80 --output-http http://staging.com
+  -output-http-elasticsearch="": Send request and response stats to ElasticSearch:
+  gor --input-raw :8080 --output-http staging.com --output-http-elasticsearch 'es_host:api_port/index_name'
+  -output-http-header-filter=[]: WARNING: `--output-http-header-filter` DEPRECATED, use `--http-allow-header` instead
+  -output-http-redirects=0: Enable how often redirects should be followed.
+  -output-http-stats=false: Report http output queue stats to console every 5 seconds. Remember to include also `--stats`
+  -output-http-workers=0: Gor uses dynamic worker scaling by default.  Enter a number to run a set number of workers.
+  -output-tcp=[]: Used for internal communication between Gor instances. Example:
+  # Listen for requests on 80 port and forward them to other Gor instance on 28020 port
+  gor --input-raw :80 --output-tcp replay.local:28020
+  -output-tcp-stats=false: Report TCP output queue stats to console every 5 seconds. Remember to include also `--stats`
+  -split-output=false: By default each output gets same traffic. If set to `true` it splits traffic equally among all outputs.
+  -stats=false: Turn on queue stats output. Use in combination with the other *-stats flags.
+  -verbose=false: Turn on verbose/debug output
+```
+
+## Building from source
+
+1. Setup standard Go environment http://golang.org/doc/code.html and ensure that $GOPATH environment variable properly set.
+2. `go get github.com/buger/gor`.
+3. `cd $GOPATH/src/github.com/buger/gor`
+4. `go build` to get binary, or `go test` to run tests
+
+## Development
+Project contains Docker environment.
+
+1. Build container: `make dbuild`
+2. Run all tests: `make dtest`. Run specific test: `make dtest ARGS=-test.run=**regexp**`
+3. Bash access to container: `make dbash`. Inside container you have python to run simple web server `python -m SimpleHTTPServer 8080` and `curl` to make http requests. 
+
+
+## Questions and support 
+
+All bug-reports and suggestions should go though Github Issues or our [Google Group](https://groups.google.com/forum/#!forum/gor-users). Or you can just send email to gor-users@googlegroups.com
+
+If you have some private questions you can send direct mail to leonsbox@gmail.com
+
+## FAQ
+
+### What OS are supported?
+For now only Linux based. *BSD (including MacOS is not supported yet, check https://github.com/buger/gor/issues/22 for details)
+
+### Why does the `--input-raw` requires sudo or root access?
+Listener works by sniffing traffic from a given port. It's accessible
+only by using sudo or root access.
+
+### How do you deal with user session to replay the traffic correctly?
+You can rewrite session related headers/params to match your staging environment. If you require custom logic (e.g random token based auth) follow this discussion: https://github.com/buger/gor/issues/154
+
+### Can i use Gor to intercept SSL traffic?
+Basic idea is that SSL was made to protect itself from traffic interception. There 2 options: 
+1. Move SSL handling to proxy like Nginx or Amazon ELB. And allow Gor to listen on upstreams. 
+2. Use `--input-http` so you can duplicate request payload directly from your app to Gor, but it will require your app modifications.
+
+More can be find here: https://github.com/buger/gor/issues/85
+
+### Is there a limit for size of HTTP request when using output-http?
+Due to the fact that Gor can't guarantee interception of all packets, for large payloads > 200kb there is chance of missing some packets and corrupting body. Treat it as a feature and chance to test broken bodies handling :)
+The only way to guarantee delivery is using `--input-http`, but you will miss some features.
+
+### I'm getting 'too many open files' error
+Typical linux shell has a small open files soft limit at 1024. You can easily raise that when you do this before starting your gor replay process:
+  
+  ulimit -n 64000
+
+More about ulimit: http://www.thecodingmachine.com/solving-the-too-many-open-files-exception-in-red5-or-any-other-application/
+
+### The CPU average across my load-balanced targets is higher than the source
+If you are replaying traffic from multiple listeners to a load-balanced target and you use sticky sessions, you may observe that the target servers have a higher CPU load than the listener servers. This may be because the sticky session cookie of the original load balancer is not honored by the target load balancer thus resulting in requests that would normally hit the same target server hitting different servers on the backend thus reducing some caching benefits gained via the load balancing.  Try running just one listener against one replay target and see if the CPU utilization comparison is more accurate.
+
+## Tuning
+
+To achieve the top most performance you should tune the source server system limits:
+
+    net.ipv4.tcp_max_tw_buckets = 65536
+    net.ipv4.tcp_tw_recycle = 1
+    net.ipv4.tcp_tw_reuse = 0
+    net.ipv4.tcp_max_syn_backlog = 131072
+    net.ipv4.tcp_syn_retries = 3
+    net.ipv4.tcp_synack_retries = 3
+    net.ipv4.tcp_retries1 = 3
+    net.ipv4.tcp_retries2 = 8
+    net.ipv4.tcp_rmem = 16384 174760 349520
+    net.ipv4.tcp_wmem = 16384 131072 262144
+    net.ipv4.tcp_mem = 262144 524288 1048576
+    net.ipv4.tcp_max_orphans = 65536
+    net.ipv4.tcp_fin_timeout = 10
+    net.ipv4.tcp_low_latency = 1
+    net.ipv4.tcp_syncookies = 0
+
+
+## Contributing
+
+1. Fork it
+2. Create your feature branch (git checkout -b my-new-feature)
+3. Commit your changes (git commit -am 'Added some feature')
+4. Push to the branch (git push origin my-new-feature)
+5. Create new Pull Request
+
+## Companies using Gor
+
+* [GOV.UK](https://www.gov.uk) - UK Government Digital Service
+* [theguardian.com](http://theguardian.com) - Most popular online newspaper in the UK
+* [TomTom](http://www.tomtom.com/) - Global leader in navigation, traffic and map products, GPS Sport Watches and fleet management solutions.
+* [3SCALE](http://www.3scale.net/) - API infrastructure to manage your APIs for internal or external users
+* [Optionlab](http://www.opinionlab.com) - Optimize customer experience and drive engagement across multiple channels
+* [TubeMogul](http://tubemogul.com) - Software for Brand Advertising
+* [Videology](http://www.videologygroup.com/) - Video advertising platform
+* [ForeksMobile](http://foreksmobile.com/) -  One of the leading financial application development company in Turkey
+* [Granify](http://granify.com) - AI backed SaaS solution that enables online retailers to maximise their sales
+* And many more!
+
+If you are using Gor we are happy add you to the list and share your story, just write to: leonsbox@gmail.com

byteutils/byteutils.go

@@ -0,0 +1,40 @@
+// Package byteutils probvides helpers for working with byte slices
+package byteutils
+
+// Cut elements from slice for a given range
+func Cut(a []byte, from, to int) []byte {
+	copy(a[from:], a[to:])
+	a = a[:len(a)-to+from]
+
+	return a
+}
+
+// Insert new slice at specified position
+func Insert(a []byte, i int, b []byte) []byte {
+	a = append(a, make([]byte, len(b))...)
+	copy(a[i+len(b):], a[i:])
+	copy(a[i:i+len(b)], b)
+
+	return a
+}
+
+// Replace function unlike bytes.Replace allows you to specify range
+func Replace(a []byte, from, to int, new []byte) []byte {
+	lenDiff := len(new) - (to - from)
+
+	if lenDiff > 0 {
+		// Extend if new segment bigger
+		a = append(a, make([]byte, lenDiff)...)
+		copy(a[to+lenDiff:], a[to:])
+		copy(a[from:from+len(new)], new)
+
+		return a
+	} else if lenDiff < 0 {
+		copy(a[from:], new)
+		copy(a[from+len(new):], a[to:])
+		return a[:len(a)+lenDiff]
+	} else { // same size
+		copy(a[from:], new)
+		return a
+	}
+}

byteutils/byteutils_test.go

@@ -0,0 +1,32 @@
+package byteutils
+
+import (
+	"bytes"
+	"testing"
+)
+
+func TestCut(t *testing.T) {
+	if !bytes.Equal(Cut([]byte("123456"), 2, 4), []byte("1256")) {
+		t.Error("Should properly cut")
+	}
+}
+
+func TestInsert(t *testing.T) {
+	if !bytes.Equal(Insert([]byte("123456"), 2, []byte("abcd")), []byte("12abcd3456")) {
+		t.Error("Should insert into middle of slice")
+	}
+}
+
+func TestReplace(t *testing.T) {
+	if !bytes.Equal(Replace([]byte("123456"), 2, 4, []byte("ab")), []byte("12ab56")) {
+		t.Error("Should replace when same length")
+	}
+
+	if !bytes.Equal(Replace([]byte("123456"), 2, 4, []byte("abcd")), []byte("12abcd56")) {
+		t.Error("Should replace when replacement length bigger")
+	}
+
+	if !bytes.Equal(Replace([]byte("123456"), 2, 5, []byte("ab")), []byte("12ab6")) {
+		t.Error("Should replace when replacement length bigger")
+	}
+}

circle.yml

@@ -0,0 +1,7 @@
+dependencies:
+  pre:
+    - sudo apt-get install libpcap-dev -y
+
+test:
+  override:
+    - sudo bash -l -c "export GOPATH='/home/ubuntu/.go_workspace:/usr/local/go_workspace:/home/ubuntu/.go_project' && GORACE='halt_on_error=1' /usr/local/go/bin/go test ./... -v -timeout 120s -race"

elasticsearch.go

@@ -0,0 +1,153 @@
+package main
+
+import (
+	"encoding/json"
+	"github.com/buger/elastigo/api"
+	"github.com/buger/elastigo/core"
+	"github.com/buger/gor/proto"
+	"log"
+	"regexp"
+	"time"
+)
+
+type ESUriErorr struct{}
+
+func (e *ESUriErorr) Error() string {
+	return "Wrong ElasticSearch URL format. Expected to be: host:port/index_name"
+}
+
+type ESPlugin struct {
+	Active  bool
+	ApiPort string
+	Host    string
+	Index   string
+	indexor *core.BulkIndexer
+	done    chan bool
+}
+
+type ESRequestResponse struct {
+	ReqUrl               []byte `json:"Req_URL"`
+	ReqMethod            []byte `json:"Req_Method"`
+	ReqUserAgent         []byte `json:"Req_User-Agent"`
+	ReqAcceptLanguage    []byte `json:"Req_Accept-Language,omitempty"`
+	ReqAccept            []byte `json:"Req_Accept,omitempty"`
+	ReqAcceptEncoding    []byte `json:"Req_Accept-Encoding,omitempty"`
+	ReqIfModifiedSince   []byte `json:"Req_If-Modified-Since,omitempty"`
+	ReqConnection        []byte `json:"Req_Connection,omitempty"`
+	ReqCookies           []byte `json:"Req_Cookies,omitempty"`
+	RespStatus           []byte `json:"Resp_Status"`
+	RespStatusCode       []byte `json:"Resp_Status-Code"`
+	RespProto            []byte `json:"Resp_Proto,omitempty"`
+	RespContentLength    []byte `json:"Resp_Content-Length,omitempty"`
+	RespContentType      []byte `json:"Resp_Content-Type,omitempty"`
+	RespTransferEncoding []byte `json:"Resp_Transfer-Encoding,omitempty"`
+	RespContentEncoding  []byte `json:"Resp_Content-Encoding,omitempty"`
+	RespExpires          []byte `json:"Resp_Expires,omitempty"`
+	RespCacheControl     []byte `json:"Resp_Cache-Control,omitempty"`
+	RespVary             []byte `json:"Resp_Vary,omitempty"`
+	RespSetCookie        []byte `json:"Resp_Set-Cookie,omitempty"`
+	Rtt                  int64  `json:"RTT"`
+	Timestamp            time.Time
+}
+
+// Parse ElasticSearch URI
+//
+// Proper format is: host:port/index_name
+func parseURI(URI string) (err error, host string, port string, index string) {
+	rURI := regexp.MustCompile("(.+):([0-9]+)/(.+)")
+	match := rURI.FindAllStringSubmatch(URI, -1)
+
+	if len(match) == 0 {
+		err = new(ESUriErorr)
+	} else {
+		host = match[0][1]
+		port = match[0][2]
+		index = match[0][3]
+	}
+
+	return
+}
+
+func (p *ESPlugin) Init(URI string) {
+	var err error
+
+	err, p.Host, p.ApiPort, p.Index = parseURI(URI)
+
+	if err != nil {
+		log.Fatal("Can't initialize ElasticSearch plugin.", err)
+	}
+
+	api.Domain = p.Host
+	api.Port = p.ApiPort
+
+	p.indexor = core.NewBulkIndexerErrors(50, 60)
+	p.done = make(chan bool)
+	p.indexor.Run(p.done)
+
+	// Only start the ErrorHandler goroutine when in verbose mode
+	// no need to burn ressources otherwise
+	// go p.ErrorHandler()
+
+	log.Println("Initialized Elasticsearch Plugin")
+	return
+}
+
+func (p *ESPlugin) IndexerShutdown() {
+	p.done <- true
+	return
+}
+
+func (p *ESPlugin) ErrorHandler() {
+	for {
+		errBuf := <-p.indexor.ErrorChannel
+		log.Println(errBuf.Err)
+	}
+}
+
+func (p *ESPlugin) RttDurationToMs(d time.Duration) int64 {
+	sec := d / time.Second
+	nsec := d % time.Second
+	fl := float64(sec) + float64(nsec)*1e-6
+	return int64(fl)
+}
+
+func (p *ESPlugin) ResponseAnalyze(req, resp []byte, start, stop time.Time) {
+	if len(resp) == 0 {
+		// nil http response - skipped elasticsearch export for this request
+		return
+	}
+	t := time.Now()
+	rtt := p.RttDurationToMs(stop.Sub(start))
+
+	esResp := ESRequestResponse{
+		ReqUrl:               proto.Path(req),
+		ReqMethod:            proto.Method(req),
+		ReqUserAgent:         proto.Header(req, []byte("User-Agent")),
+		ReqAcceptLanguage:    proto.Header(req, []byte("Accept-Language")),
+		ReqAccept:            proto.Header(req, []byte("Accept")),
+		ReqAcceptEncoding:    proto.Header(req, []byte("Accept-Encoding")),
+		ReqIfModifiedSince:   proto.Header(req, []byte("If-Modified-Since")),
+		ReqConnection:        proto.Header(req, []byte("Connection")),
+		ReqCookies:           proto.Header(req, []byte("Cookie")),
+		RespStatus:           proto.Status(resp),
+		RespStatusCode:       proto.Status(resp),
+		RespProto:            proto.Method(resp),
+		RespContentLength:    proto.Header(resp, []byte("Content-Length")),
+		RespContentType:      proto.Header(resp, []byte("Content-Type")),
+		RespTransferEncoding: proto.Header(resp, []byte("Transfer-Encoding")),
+		RespContentEncoding:  proto.Header(resp, []byte("Content-Encoding")),
+		RespExpires:          proto.Header(resp, []byte("Expires")),
+		RespCacheControl:     proto.Header(resp, []byte("Cache-Control")),
+		RespVary:             proto.Header(resp, []byte("Vary")),
+		RespSetCookie:        proto.Header(resp, []byte("Set-Cookie")),
+		Rtt:                  rtt,
+		Timestamp:            t,
+	}
+	j, err := json.Marshal(&esResp)
+	if err != nil {
+		log.Println(err)
+	} else {
+		p.indexor.Index(p.Index, "RequestResponse", "", "", &t, j, true)
+	}
+	return
+}

elasticsearch/elasticsearch.go

@@ -1,153 +0,0 @@
-package gor
-
-import (
-	"encoding/json"
-	"github.com/mattbaird/elastigo/api"
-	"github.com/mattbaird/elastigo/core"
-	"log"
-	"net/http"
-	"regexp"
-	"time"
-)
-
-type ESUriErorr struct{}
-
-func (e *ESUriErorr) Error() string {
-	return "Wrong ElasticSearch URL format. Expected to be: host:port/index_name"
-}
-
-type ESPlugin struct {
-	Active  bool
-	ApiPort string
-	Host    string
-	Index   string
-	indexor *core.BulkIndexer
-	done    chan bool
-}
-
-type ESRequestResponse struct {
-	ReqUrl               string         `json:"Req_URL"`
-	ReqMethod            string         `json:"Req_Method"`
-	ReqUserAgent         string         `json:"Req_User-Agent"`
-	ReqAcceptLanguage    string         `json:"Req_Accept-Language,omitempty"`
-	ReqAccept            string         `json:"Req_Accept,omitempty"`
-	ReqAcceptEncoding    string         `json:"Req_Accept-Encoding,omitempty"`
-	ReqIfModifiedSince   string         `json:"Req_If-Modified-Since,omitempty"`
-	ReqConnection        string         `json:"Req_Connection,omitempty"`
-	ReqCookies           []*http.Cookie `json:"Req_Cookies,omitempty"`
-	RespStatus           string         `json:"Resp_Status"`
-	RespStatusCode       int            `json:"Resp_Status-Code"`
-	RespProto            string         `json:"Resp_Proto,omitempty"`
-	RespContentLength    int64          `json:"Resp_Content-Length,omitempty"`
-	RespContentType      string         `json:"Resp_Content-Type,omitempty"`
-	RespTransferEncoding []string       `json:"Resp_Transfer-Encoding,omitempty"`
-	RespContentEncoding  string         `json:"Resp_Content-Encoding,omitempty"`
-	RespExpires          string         `json:"Resp_Expires,omitempty"`
-	RespCacheControl     string         `json:"Resp_Cache-Control,omitempty"`
-	RespVary             string         `json:"Resp_Vary,omitempty"`
-	RespSetCookie        string         `json:"Resp_Set-Cookie,omitempty"`
-	Rtt                  int64          `json:"RTT"`
-	Timestamp            time.Time
-}
-
-// Parse ElasticSearch URI
-//
-// Proper format is: host:port/index_name
-func parseURI(URI string) (err error, host string, port string, index string) {
-	rURI := regexp.MustCompile("(.+):([0-9]+)/(.+)")
-	match := rURI.FindAllStringSubmatch(URI, -1)
-
-	if len(match) == 0 {
-		err = new(ESUriErorr)
-	} else {
-		host = match[0][1]
-		port = match[0][2]
-		index = match[0][3]
-	}
-
-	return
-}
-
-func (p *ESPlugin) Init(URI string) {
-	var err error
-
-	err, p.Host, p.ApiPort, p.Index = parseURI(URI)
-
-	if err != nil {
-		log.Fatal("Can't initialize ElasticSearch plugin.", err)
-	}
-
-	api.Domain = p.Host
-	api.Port = p.ApiPort
-
-	p.indexor = core.NewBulkIndexerErrors(50, 60)
-	p.done = make(chan bool)
-	p.indexor.Run(p.done)
-
-	// Only start the ErrorHandler goroutine when in verbose mode
-	// no need to burn ressources otherwise
-	// go p.ErrorHandler()
-
-	log.Println("Initialized Elasticsearch Plugin")
-	return
-}
-
-func (p *ESPlugin) IndexerShutdown() {
-	p.done <- true
-	return
-}
-
-func (p *ESPlugin) ErrorHandler() {
-	for {
-		errBuf := <-p.indexor.ErrorChannel
-		log.Println(errBuf.Err)
-	}
-}
-
-func (p *ESPlugin) RttDurationToMs(d time.Duration) int64 {
-	sec := d / time.Second
-	nsec := d % time.Second
-	fl := float64(sec) + float64(nsec)*1e-6
-	return int64(fl)
-}
-
-func (p *ESPlugin) ResponseAnalyze(req *http.Request, resp *http.Response, start, stop time.Time) {
-	if resp == nil {
-		// nil http response - skipped elasticsearch export for this request
-		return
-	}
-	t := time.Now()
-	rtt := p.RttDurationToMs(stop.Sub(start))
-
-	esResp := ESRequestResponse{
-		ReqUrl:               req.URL.String(),
-		ReqMethod:            req.Method,
-		ReqUserAgent:         req.UserAgent(),
-		ReqAcceptLanguage:    req.Header.Get("Accept-Language"),
-		ReqAccept:            req.Header.Get("Accept"),
-		ReqAcceptEncoding:    req.Header.Get("Accept-Encoding"),
-		ReqIfModifiedSince:   req.Header.Get("If-Modified-Since"),
-		ReqConnection:        req.Header.Get("Connection"),
-		ReqCookies:           req.Cookies(),
-		RespStatus:           resp.Status,
-		RespStatusCode:       resp.StatusCode,
-		RespProto:            resp.Proto,
-		RespContentLength:    resp.ContentLength,
-		RespContentType:      resp.Header.Get("Content-Type"),
-		RespTransferEncoding: resp.TransferEncoding,
-		RespContentEncoding:  resp.Header.Get("Content-Encoding"),
-		RespExpires:          resp.Header.Get("Expires"),
-		RespCacheControl:     resp.Header.Get("Cache-Control"),
-		RespVary:             resp.Header.Get("Vary"),
-		RespSetCookie:        resp.Header.Get("Set-Cookie"),
-		Rtt:                  rtt,
-		Timestamp:            t,
-	}
-	j, err := json.Marshal(&esResp)
-	if err != nil {
-		log.Println(err)
-	} else {
-		p.indexor.Index(p.Index, "RequestResponse", "", "", &t, j)
-	}
-	return
-}

emitter.go

@@ -1,33 +1,87 @@
-package gor
+package main
 
 import (
+	"bytes"
 	"io"
+	"time"
 )
 
+// Start initialize loop for sending data from inputs to outputs
 func Start(stop chan int) {
-	for _, in := range Plugins.Inputs {
-		go CopyMulty(in, Plugins.Outputs...)
+	if Settings.middleware != "" {
+		middleware := NewMiddleware(Settings.middleware)
+
+		for _, in := range Plugins.Inputs {
+			middleware.ReadFrom(in)
+		}
+
+		// We going only to read responses, so using same ReadFrom method
+		for _, out := range Plugins.Outputs {
+			if r, ok := out.(io.Reader); ok {
+				middleware.ReadFrom(r)
+			}
+		}
+
+		go CopyMulty(middleware, Plugins.Outputs...)
+	} else {
+		for _, in := range Plugins.Inputs {
+			go CopyMulty(in, Plugins.Outputs...)
+		}
 	}
 
-	select {
-	case <-stop:
-		return
+	for {
+		select {
+		case <-stop:
+			return
+		case <-time.After(time.Second):
+		}
 	}
 }
 
-// Copy from 1 reader to multiple writers
+// CopyMulty copies from 1 reader to multiple writers
 func CopyMulty(src io.Reader, writers ...io.Writer) (err error) {
-	buf := make([]byte, 32*1024)
+	buf := make([]byte, 5*1024*1024)
 	wIndex := 0
+	modifier := NewHTTPModifier(&Settings.modifierConfig)
 
 	for {
 		nr, er := src.Read(buf)
-		if nr > 0 {
-			Debug("Sending", src, ": ", string(buf[0:nr]))
+
+		if nr > 0 && len(buf) > nr {
+			payload := buf[:nr]
+
+			_maxN := nr
+			if nr > 500 {
+				_maxN = 500
+			}
+
+			if Settings.debug {
+				Debug("[EMITTER] input:", string(payload[0:_maxN]), nr, "from:", src)
+			}
+
+			if modifier != nil && isRequestPayload(payload) {
+				headSize := bytes.IndexByte(payload, '\n') + 1
+				body := payload[headSize:]
+				originalBodyLen := len(body)
+				body = modifier.Rewrite(body)
+
+				// If modifier tells to skip request
+				if len(body) == 0 {
+					continue
+				}
+
+				if originalBodyLen != len(body) {
+					payload = append(payload[:headSize], body...)
+				}
+
+				if Settings.debug {
+					Debug("[EMITTER] Rewrittern input:", len(payload), "First 500 bytes:", string(payload[0:_maxN]))
+				}
+			}
 
 			if Settings.splitOutput {
 				// Simple round robin
-				writers[wIndex].Write(buf[0:nr])
+				writers[wIndex].Write(payload)
 
 				wIndex++
 
@@ -36,7 +90,7 @@ func CopyMulty(src io.Reader, writers ...io.Writer) (err error) {
 				}
 			} else {
 				for _, dst := range writers {
-					dst.Write(buf[0:nr])
+					dst.Write(payload)
 				}
 			}
 

emitter_test.go

@@ -1,4 +1,4 @@
-package gor
+package main
 
 import (
 	"io"

examples/middleware/echo.java

@@ -0,0 +1,30 @@
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+
+import org.apache.commons.io.IOUtils;
+
+public class echo {
+    public static void main(String[] args) {
+        if(args != null){
+            for(String arg : args){
+                System.out.println(arg);
+            }
+
+        }
+
+        BufferedReader stdin = new BufferedReader(new InputStreamReader(
+                System.in));
+        String line = null;
+
+        try {
+            while ((line = stdin.readLine()) != null) {
+
+                System.out.println(line);
+
+            }
+        } catch (IOException e) {
+            IOUtils.closeQuietly(stdin);
+        }
+    }
+}

examples/middleware/echo.rb

@@ -0,0 +1,15 @@
+#!/usr/bin/env ruby
+# encoding: utf-8
+while data = STDIN.gets
+  next unless data
+  data = data.chomp
+
+  decoded = [data].pack("H*")
+  encoded = decoded.unpack("H*").first
+
+  STDOUT.puts encoded
+
+  STDERR.puts "[DEBUG][MIDDLEWARE] Original data: #{data}"
+  STDERR.puts "[DEBUG][MIDDLEWARE] Decoded request: #{decoded}"
+  STDERR.puts "[DEBUG][MIDDLEWARE] Encoded data: #{encoded}"
+end

examples/middleware/echo.sh

@@ -0,0 +1,42 @@
+#!/usr/bin/env bash
+#
+# `xxd` utility included into vim-common package
+# It allow hex decoding/encoding
+
+function log {
+    # Logging to stderr, because stdout/stdin used for data transfer
+    >&2 echo "[DEBUG][ECHO] $1"
+}
+
+while read line; do
+    decoded=$(echo -e "$line" | xxd -r -p)
+
+    header=$(echo -e "$decoded" | head -n +1)
+    payload=$(echo -e "$decoded" | tail -n +2)
+
+    encoded=$(echo -e "$header\n$payload" | xxd -p | tr -d "\\n")
+
+    log ""
+    log "==================================="
+
+    case ${header:0:1} in
+    "1")
+        log "Request type: Request"
+        ;;
+    "2")
+        log "Request type: Original Response"
+        ;;
+    "3")
+        log "Request type: Replayed Response"
+        ;;
+    *)
+        log "Unknown request type $header"
+    esac
+    echo "$encoded"
+
+    log "==================================="
+
+    log "Original data: $line"
+    log "Decoded request: $decoded"
+    log "Encoded data: $encoded"
+done;

examples/middleware/token_modifier.go

@@ -0,0 +1,119 @@
+/*
+This middleware made for auth system that randomly generate access tokens, which used later for accessing secure content. Since there is no pre-defined token value, naive approach without middleware (or if middleware use only request payloads) will fail, because replayed server have own tokens, not synced with origin. To fix this, our middleware should take in account responses of replayed and origin server, store `originalToken -> replayedToken` aliases and rewrite all requests using this token to use replayed alias. See `middleware_test.go#TestTokenMiddleware` test for examples of using this middleware.
+
+How middleware works:
+
+                   Original request      +--------------+
++-------------+----------STDIN---------->+              |
+|  Gor input  |                          |  Middleware  |
++-------------+----------STDIN---------->+              |
+                   Original response     +------+---+---+
+                                                |   ^
++-------------+    Modified request             v   |
+| Gor output  +<---------STDOUT-----------------+   |
++-----+-------+                                     |
+      |                                             |
+      |            Replayed response                |
+      +------------------STDIN----------------->----+
+*/
+
+package main
+
+import (
+	"bufio"
+	"bytes"
+	"encoding/hex"
+	"fmt"
+	"github.com/buger/gor/proto"
+	"os"
+)
+
+// requestID -> originalToken
+var originalTokens map[string][]byte
+
+// originalToken -> replayedToken
+var tokenAliases map[string][]byte
+
+func main() {
+	originalTokens = make(map[string][]byte)
+	tokenAliases = make(map[string][]byte)
+
+	scanner := bufio.NewScanner(os.Stdin)
+
+	for scanner.Scan() {
+		encoded := scanner.Bytes()
+		buf := make([]byte, len(encoded)/2)
+		hex.Decode(buf, encoded)
+
+		process(buf)
+	}
+}
+
+func process(buf []byte) {
+	// First byte indicate payload type, possible values:
+	//  1 - Request
+	//  2 - Response
+	//  3 - ReplayedResponse
+	payloadType := buf[0]
+	headerSize := bytes.IndexByte(buf, '\n') + 1
+	header := buf[:headerSize-1]
+
+	// Header contains space separated values of: request type, request id, and request start time (or round-trip time for responses)
+	meta := bytes.Split(header, []byte(" "))
+	// For each request you should receive 3 payloads (request, response, replayed response) with same request id
+	reqID := string(meta[1])
+	payload := buf[headerSize:]
+
+	Debug("Received payload:", string(buf))
+
+	switch payloadType {
+	case '1': // Request
+		if bytes.Equal(proto.Path(payload), []byte("/token")) {
+			originalTokens[reqID] = []byte{}
+			Debug("Found token request:", reqID)
+		} else {
+			token, vs, _ := proto.PathParam(payload, []byte("token"))
+
+			if vs != -1 { // If there is GET token param
+				if alias, ok := tokenAliases[string(token)]; ok {
+					// Rewrite original token to alias
+					payload = proto.SetPathParam(payload, []byte("token"), alias)
+
+					// Copy modified payload to our buffer
+					buf = append(buf[:headerSize], payload...)
+				}
+			}
+		}
+
+		// Emitting data back
+		os.Stdout.Write(encode(buf))
+	case '2': // Original response
+		if _, ok := originalTokens[reqID]; ok {
+			// Token is inside response body
+			secureToken := proto.Body(payload)
+			originalTokens[reqID] = secureToken
+			Debug("Remember origial token:", string(secureToken))
+		}
+	case '3': // Replayed response
+		if originalToken, ok := originalTokens[reqID]; ok {
+			delete(originalTokens, reqID)
+			secureToken := proto.Body(payload)
+			tokenAliases[string(originalToken)] = secureToken
+
+			Debug("Create alias for new token token, was:", string(originalToken), "now:", string(secureToken))
+		}
+	}
+}
+
+func encode(buf []byte) []byte {
+	dst := make([]byte, len(buf)*2+1)
+	hex.Encode(dst, buf)
+	dst[len(dst)-1] = '\n'
+
+	return dst
+}
+
+func Debug(args ...interface{}) {
+	fmt.Fprint(os.Stderr, "[DEBUG][TOKEN-MOD] ")
+	fmt.Fprintln(os.Stderr, args...)
+}

gor.go

@@ -7,11 +7,10 @@ import (
 	"fmt"
 	"log"
 	"os"
-	"runtime/debug"
+	"runtime"
+	_ "runtime/debug"
 	"runtime/pprof"
 	"time"
-
-	"github.com/buger/gor"
 )
 
 var (
@@ -21,21 +20,24 @@ var (
 )
 
 func main() {
-	// Don't exit on panic
-	defer func() {
-		if r := recover(); r != nil {
-			if _, ok := r.(error); !ok {
-				fmt.Printf("PANIC: pkg: %v %s \n", r, debug.Stack())
-			}
-		}
-	}()
+	// // Don't exit on panic
+	// defer func() {
+	// 	if r := recover(); r != nil {
+	// 		fmt.Printf("PANIC: pkg: %v %s \n", r, debug.Stack())
+	// 	}
+	// }()
 
-	fmt.Println("Version:", gor.VERSION)
+	// If not set via env cariable
+	if len(os.Getenv("GOMAXPROCS")) == 0 {
+		runtime.GOMAXPROCS(runtime.NumCPU() * 2)
+	}
+
+	fmt.Println("Version:", VERSION)
 
 	flag.Parse()
-	gor.InitPlugins()
+	InitPlugins()
 
-	if len(gor.Plugins.Inputs) == 0 || len(gor.Plugins.Outputs) == 0 {
+	if len(Plugins.Inputs) == 0 || len(Plugins.Outputs) == 0 {
 		log.Fatal("Required at least 1 input and 1 output")
 	}
 
@@ -47,7 +49,7 @@ func main() {
 		profileCPU(*cpuprofile)
 	}
 
-	gor.Start(nil)
+	Start(nil)
 }
 
 func profileCPU(cpuprofile string) {
@@ -58,10 +60,10 @@ func profileCPU(cpuprofile string) {
 		}
 		pprof.StartCPUProfile(f)
 
-		time.AfterFunc(60*time.Second, func() {
+		time.AfterFunc(30*time.Second, func() {
 			pprof.StopCPUProfile()
 			f.Close()
-			log.Println("Stop profiling after 60 seconds")
+			log.Println("Stop profiling after 30 seconds")
 		})
 	}
 }
@@ -72,7 +74,7 @@ func profileMEM(memprofile string) {
 		if err != nil {
 			log.Fatal(err)
 		}
-		time.AfterFunc(60*time.Second, func() {
+		time.AfterFunc(30*time.Second, func() {
 			pprof.WriteHeapProfile(f)
 			f.Close()
 		})

gor_stat.go

@@ -0,0 +1,67 @@
+package main
+
+import (
+	"log"
+	"runtime"
+	"strconv"
+	"time"
+)
+
+const (
+	rate = 5
+)
+
+type GorStat struct {
+	statName string
+	latest   int
+	mean     int
+	max      int
+	count    int
+}
+
+func NewGorStat(statName string) (s *GorStat) {
+	s = new(GorStat)
+	s.statName = statName
+	s.latest = 0
+	s.mean = 0
+	s.max = 0
+	s.count = 0
+
+	if Settings.stats {
+		log.Println(s.statName + ":latest,mean,max,count,count/second,gcount")
+		go s.reportStats()
+	}
+	return
+}
+
+func (s *GorStat) Write(latest int) {
+	if Settings.stats {
+		if latest > s.max {
+			s.max = latest
+		}
+		if latest != 0 {
+			s.mean = (s.mean + latest) / 2
+		}
+		s.latest = latest
+		s.count = s.count + 1
+	}
+}
+
+func (s *GorStat) Reset() {
+	s.latest = 0
+	s.max = 0
+	s.mean = 0
+	s.count = 0
+}
+
+func (s *GorStat) String() string {
+	return s.statName + ":" + strconv.Itoa(s.latest) + "," + strconv.Itoa(s.mean) + "," + strconv.Itoa(s.max) + "," + strconv.Itoa(s.count) + "," + strconv.Itoa(s.count/rate) + "," + strconv.Itoa(runtime.NumGoroutine())
+}
+
+func (s *GorStat) reportStats() {
+	for {
+		log.Println(s)
+		s.Reset()
+		time.Sleep(rate * time.Second)
+	}
+}

http_client.go

@@ -0,0 +1,245 @@
+package main
+
+import (
+	"crypto/tls"
+	"github.com/buger/gor/proto"
+	"io"
+	"log"
+	"net"
+	"net/url"
+	"runtime/debug"
+	"strconv"
+	"strings"
+	"syscall"
+	"time"
+)
+
+var defaultPorts = map[string]string{
+	"http":  "80",
+	"https": "443",
+}
+
+type HTTPClientConfig struct {
+	FollowRedirects    int
+	Debug              bool
+	OriginalHost       bool
+	ConnectionTimeout  time.Duration
+	Timeout            time.Duration
+	ResponseBufferSize int
+}
+
+type HTTPClient struct {
+	baseURL        string
+	scheme         string
+	host           string
+	conn           net.Conn
+	respBuf        []byte
+	config         *HTTPClientConfig
+	redirectsCount int
+}
+
+func NewHTTPClient(baseURL string, config *HTTPClientConfig) *HTTPClient {
+	if !strings.HasPrefix(baseURL, "http") {
+		baseURL = "http://" + baseURL
+	}
+
+	u, _ := url.Parse(baseURL)
+	if !strings.Contains(u.Host, ":") {
+		if u.Scheme != "http" {
+			u.Host += ":" + defaultPorts[u.Scheme]
+		}
+	}
+
+	if config.Timeout.Nanoseconds() == 0 {
+		config.Timeout = 5 * time.Second
+	}
+
+	if config.ResponseBufferSize == 0 {
+		config.ResponseBufferSize = 100 * 1024 // 100kb
+	}
+
+	client := new(HTTPClient)
+	client.baseURL = u.String()
+	client.host = u.Host
+	client.scheme = u.Scheme
+	client.respBuf = make([]byte, config.ResponseBufferSize)
+	client.config = config
+
+	return client
+}
+
+func (c *HTTPClient) Connect() (err error) {
+	c.Disconnect()
+
+	if !strings.Contains(c.host, ":") {
+		c.conn, err = net.DialTimeout("tcp", c.host+":80", c.config.ConnectionTimeout)
+	} else {
+		c.conn, err = net.DialTimeout("tcp", c.host, c.config.ConnectionTimeout)
+	}
+
+	if c.scheme == "https" {
+		tlsConn := tls.Client(c.conn, &tls.Config{InsecureSkipVerify: true})
+
+		if err = tlsConn.Handshake(); err != nil {
+			return
+		}
+
+		c.conn = tlsConn
+	}
+
+	return
+}
+
+func (c *HTTPClient) Disconnect() {
+	if c.conn != nil {
+		c.conn.Close()
+		c.conn = nil
+		Debug("[HTTP] Disconnected: ", c.baseURL)
+	}
+}
+
+func (c *HTTPClient) isAlive() bool {
+	one := make([]byte, 1)
+
+	// Ready 1 byte from socket without timeout to check if it not closed
+	c.conn.SetReadDeadline(time.Now().Add(time.Millisecond))
+	_, err := c.conn.Read(one)
+
+	if err == nil {
+		return true
+	} else if err == io.EOF {
+		return false
+	} else if err == syscall.EPIPE {
+		Debug("Detected broken pipe.", err)
+		return false
+	}
+
+	return true
+}
+
+func (c *HTTPClient) Send(data []byte) (response []byte, err error) {
+	// Don't exit on panic
+	defer func() {
+		if r := recover(); r != nil {
+			Debug("[HTTPClient]", r, string(data))
+
+			if _, ok := r.(error); !ok {
+				log.Println("[HTTPClient] Failed to send request: ", string(data))
+				log.Println("PANIC: pkg:", r, debug.Stack())
+			}
+		}
+	}()
+
+	if c.conn == nil || !c.isAlive() {
+		Debug("[HTTPClient] Connecting:", c.baseURL)
+		if err = c.Connect(); err != nil {
+			log.Println("[HTTPClient] Connection error:", err)
+			response = errorPayload(HTTP_CONNECTION_ERROR)
+			return
+		}
+	}
+
+	timeout := time.Now().Add(c.config.Timeout)
+
+	c.conn.SetWriteDeadline(timeout)
+
+	if !c.config.OriginalHost {
+		data = proto.SetHost(data, []byte(c.baseURL), []byte(c.host))
+	}
+
+	if c.config.Debug {
+		Debug("[HTTPClient] Sending:", string(data))
+	}
+
+	if _, err = c.conn.Write(data); err != nil {
+		Debug("[HTTPClient] Write error:", err, c.baseURL)
+		response = errorPayload(HTTP_TIMEOUT)
+		return
+	}
+
+	c.conn.SetReadDeadline(timeout)
+	n, err := c.conn.Read(c.respBuf)
+
+	// If response large then our buffer, we need to read all response buffer
+	// Otherwise it will corrupt response of next request
+	// Parsing response body is non trivial thing, especially with keep-alive
+	// Simples case is to to close connection if response too large
+	//
+	// See https://github.com/buger/gor/issues/184
+	if n == len(c.respBuf) {
+		c.Disconnect()
+	}
+
+	if err != nil {
+		Debug("[HTTPClient] Response read error", err, c.conn)
+		response = errorPayload(HTTP_TIMEOUT)
+		return
+	}
+
+	payload := c.respBuf[:n]
+
+	if c.config.Debug {
+		Debug("[HTTPClient] Received:", string(payload))
+	}
+
+	if c.config.FollowRedirects > 0 && c.redirectsCount < c.config.FollowRedirects {
+		status := payload[9:12]
+
+		// 3xx requests
+		if status[0] == '3' {
+			c.redirectsCount++
+
+			location := proto.Header(payload, []byte("Location"))
+			redirectPayload := []byte("GET " + string(location) + " HTTP/1.1\r\n\r\n")
+
+			if c.config.Debug {
+				Debug("[HTTPClient] Redirecting to: " + string(location))
+			}
+
+			return c.Send(redirectPayload)
+		}
+	}
+
+	c.redirectsCount = 0
+
+	return payload, err
+}
+
+func (c *HTTPClient) Get(path string) (response []byte, err error) {
+	payload := "GET " + path + " HTTP/1.1\r\n\r\n"
+
+	return c.Send([]byte(payload))
+}
+
+func (c *HTTPClient) Post(path string, body []byte) (response []byte, err error) {
+	payload := "POST " + path + " HTTP/1.1\r\n"
+	payload += "Content-Length: " + strconv.Itoa(len(body)) + "\r\n\r\n"
+	payload += string(body)
+
+	return c.Send([]byte(payload))
+}
+
+const (
+	// https://support.cloudflare.com/hc/en-us/articles/200171936-Error-520-Web-server-is-returning-an-unknown-error
+	HTTP_UNKNOWN_ERROR = "520"
+	// https://support.cloudflare.com/hc/en-us/articles/200171916-Error-521-Web-server-is-down
+	HTTP_CONNECTION_ERROR = "521"
+	// https://support.cloudflare.com/hc/en-us/articles/200171906-Error-522-Connection-timed-out
+	HTTP_CONNECTION_TIMEOUT = "522"
+	// https://support.cloudflare.com/hc/en-us/articles/200171946-Error-523-Origin-is-unreachable
+	HTTP_UNREACHABLE = "523"
+	// https://support.cloudflare.com/hc/en-us/articles/200171926-Error-524-A-timeout-occurred
+	HTTP_TIMEOUT = "524"
+)
+
+var errorPayloadTemplate = "HTTP/1.1 202 Accepted\r\nDate: Mon, 17 Aug 2015 14:10:11 GMT\r\nContent-Length: 0\r\nContent-Type: text/plain; charset=utf-8\r\n\r\n"
+
+func errorPayload(errorCode string) []byte {
+	payload := make([]byte, len(errorPayloadTemplate))
+	copy(payload, errorPayloadTemplate)
+
+	copy(payload[29:58], []byte(time.Now().Format(time.RFC1123)))
+	copy(payload[9:12], errorCode)
+
+	return payload
+}

http_client_test.go

@@ -0,0 +1,400 @@
+package main
+
+import (
+	"bytes"
+	"crypto/rand"
+	"github.com/buger/gor/proto"
+	"io/ioutil"
+	_ "log"
+	"net"
+	"net/http"
+	"net/http/httptest"
+	"net/http/httputil"
+	_ "reflect"
+	"sync"
+	"testing"
+	"time"
+	_ "time"
+)
+
+func TestHTTPClientURLPort(t *testing.T) {
+	c1 := NewHTTPClient("http://example.com", &HTTPClientConfig{})
+	if c1.baseURL != "http://example.com" {
+		t.Error("Sould not add 80 port for http:", c1.baseURL)
+	}
+
+	c2 := NewHTTPClient("https://example.com", &HTTPClientConfig{})
+	if c2.baseURL != "https://example.com:443" {
+		t.Error("Sould add 443 port for https:", c2.baseURL)
+	}
+
+	c3 := NewHTTPClient("https://example.com:1", &HTTPClientConfig{})
+	if c3.baseURL != "https://example.com:1" {
+		t.Error("Sould use specified port:", c3.baseURL)
+	}
+
+	c4 := NewHTTPClient("example.com", &HTTPClientConfig{})
+	if c4.baseURL != "http://example.com" {
+		t.Error("Sould not add default protocol:", c4.baseURL)
+	}
+}
+
+func TestHTTPClientSend(t *testing.T) {
+	wg := new(sync.WaitGroup)
+
+	payload := func(reqType string) []byte {
+		switch reqType {
+		case "GET":
+			return []byte("GET / HTTP/1.1\r\n\r\n")
+		case "POST":
+			return []byte("POST /post HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+		case "POST_CHUNKED":
+			return []byte("POST / HTTP/1.1\r\nHost: www.w3.org\r\nTransfer-Encoding: chunked\r\n\r\n4\r\nWiki\r\n5\r\npedia\r\ne\r\n in\r\n\r\nchunks.\r\n0\r\n\r\n")
+		}
+
+		return []byte("")
+	}
+
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+
+		if r.Method == "POST" {
+			defer r.Body.Close()
+			body, _ := ioutil.ReadAll(r.Body)
+
+			if len(r.TransferEncoding) > 0 && r.TransferEncoding[0] == "chunked" {
+				if string(body) != "Wikipedia in\r\n\r\nchunks." {
+					t.Error("Wrong POST body:", body, string(body))
+				}
+			} else {
+				if string(body) != "a=1&b=2" {
+					buf, _ := httputil.DumpRequest(r, true)
+					t.Error("Wrong POST body:", string(body), string(buf))
+				}
+			}
+		}
+
+		wg.Done()
+	}))
+	defer server.Close()
+
+	client := NewHTTPClient(server.URL, &HTTPClientConfig{Debug: true})
+
+	wg.Add(4)
+	client.Send(payload("POST"))
+	client.Send(payload("GET"))
+	client.Send(payload("POST_CHUNKED"))
+	client.Send(payload("POST"))
+
+	wg.Wait()
+}
+
+// https://github.com/buger/gor/issues/184
+func TestHTTPClientResponseBuffer(t *testing.T) {
+	wg := new(sync.WaitGroup)
+
+	payload := []byte("GET / HTTP/1.1\r\n\r\n")
+
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+
+		size := 10 * 1024 // 10kb
+		rb := make([]byte, size)
+		rand.Read(rb)
+
+		w.Write(rb)
+
+		wg.Done()
+	}))
+	defer server.Close()
+
+	client := NewHTTPClient(server.URL, &HTTPClientConfig{Debug: false, ResponseBufferSize: 1024})
+
+	wg.Add(2)
+	client.Send(payload)
+	resp, _ := client.Send(payload)
+
+	if !bytes.Equal(resp[0:8], []byte("HTTP/1.1")) {
+		t.Error("Response buffer contains data from previous request", string(resp[0:5]))
+	}
+
+	wg.Wait()
+}
+
+func TestHTTPClientHTTPSSend(t *testing.T) {
+	wg := new(sync.WaitGroup)
+
+	payload := func(reqType string) []byte {
+		switch reqType {
+		case "GET":
+			return []byte("GET / HTTP/1.1\r\n\r\n")
+		case "POST":
+			return []byte("POST /post HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+		case "POST_CHUNKED":
+			return []byte("POST / HTTP/1.1\r\nHost: www.w3.org\r\nTransfer-Encoding: chunked\r\n\r\n4\r\nWiki\r\n5\r\npedia\r\ne\r\n in\r\n\r\nchunks.\r\n0\r\n\r\n")
+		}
+
+		return []byte("")
+	}
+
+	server := httptest.NewTLSServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+
+		if r.Method == "POST" {
+			defer r.Body.Close()
+			body, _ := ioutil.ReadAll(r.Body)
+
+			if len(r.TransferEncoding) > 0 && r.TransferEncoding[0] == "chunked" {
+				if string(body) != "Wikipedia in\r\n\r\nchunks." {
+					t.Error("Wrong POST body:", body, string(body))
+				}
+			} else {
+				if string(body) != "a=1&b=2" {
+					buf, _ := httputil.DumpRequest(r, true)
+					t.Error("Wrong POST body:", string(body), string(buf))
+				}
+			}
+		}
+
+		wg.Done()
+	}))
+	defer server.Close()
+
+	client := NewHTTPClient(server.URL, &HTTPClientConfig{})
+
+	wg.Add(4)
+	client.Send(payload("POST"))
+	client.Send(payload("GET"))
+	client.Send(payload("POST_CHUNKED"))
+	client.Send(payload("POST"))
+
+	wg.Wait()
+}
+
+func TestHTTPClientServerInstantDisconnect(t *testing.T) {
+	wg := new(sync.WaitGroup)
+
+	GETPayload := []byte("GET / HTTP/1.1\r\n\r\n")
+
+	ln, _ := net.Listen("tcp", "127.0.0.1:0")
+	defer ln.Close()
+
+	go func() {
+		for {
+			conn, err := ln.Accept()
+
+			if err != nil {
+				break
+			}
+			conn.Close()
+			wg.Done()
+		}
+	}()
+
+	client := NewHTTPClient(ln.Addr().String(), &HTTPClientConfig{})
+
+	wg.Add(2)
+	client.Send(GETPayload)
+	client.Send(GETPayload)
+
+	wg.Wait()
+}
+
+func TestHTTPClientServerNoKeepAlive(t *testing.T) {
+	wg := new(sync.WaitGroup)
+
+	GETPayload := []byte("GET / HTTP/1.1\r\n\r\n")
+
+	ln, _ := net.Listen("tcp", "127.0.0.1:0")
+	defer ln.Close()
+
+	go func() {
+		for {
+			conn, err := ln.Accept()
+			if err != nil {
+				break
+			}
+
+			buf := make([]byte, 4096)
+			reqLen, err := conn.Read(buf)
+			if err != nil {
+				t.Error("Error reading:", err.Error())
+			}
+			Debug("Received: ", string(buf[0:reqLen]))
+			conn.Write([]byte("OK"))
+
+			// No keep-alive connections
+			conn.Close()
+
+			wg.Done()
+		}
+	}()
+
+	client := NewHTTPClient(ln.Addr().String(), &HTTPClientConfig{})
+
+	wg.Add(2)
+	client.Send(GETPayload)
+	client.Send(GETPayload)
+
+	wg.Wait()
+}
+
+func TestHTTPClientRedirect(t *testing.T) {
+	wg := new(sync.WaitGroup)
+
+	GETPayload := []byte("GET / HTTP/1.1\r\n\r\n")
+
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+
+		if r.URL.Path == "/" {
+			http.Redirect(w, r, "/new", 301)
+		}
+
+		wg.Done()
+	}))
+	defer server.Close()
+
+	client := NewHTTPClient(server.URL, &HTTPClientConfig{FollowRedirects: 1, Debug: false})
+
+	// Should do 2 queries
+	wg.Add(2)
+	client.Send(GETPayload)
+
+	wg.Wait()
+}
+
+func TestHTTPClientRedirectLimit(t *testing.T) {
+	wg := new(sync.WaitGroup)
+
+	GETPayload := []byte("GET / HTTP/1.1\r\n\r\n")
+
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+
+		if r.URL.Path == "/" {
+			http.Redirect(w, r, "/r1", 301)
+		}
+
+		if r.URL.Path == "/r1" {
+			http.Redirect(w, r, "/r2", 301)
+		}
+
+		if r.URL.Path == "/r2" {
+			http.Redirect(w, r, "/new", 301)
+		}
+
+		wg.Done()
+	}))
+	defer server.Close()
+
+	client := NewHTTPClient(server.URL, &HTTPClientConfig{FollowRedirects: 2, Debug: false})
+
+	// Have 3 redirects + 1 GET, but should do only 2 redirects + GET
+	wg.Add(3)
+	client.Send(GETPayload)
+
+	wg.Wait()
+}
+
+func TestHTTPClientHandleHTTP10(t *testing.T) {
+	wg := new(sync.WaitGroup)
+
+	GETPayload := []byte("GET http://foobar.com/path HTTP/1.0\r\n\r\n")
+
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+
+		if r.URL.Path != "/path" {
+			t.Error("Path not match:", r.URL.Path)
+		}
+
+		wg.Done()
+	}))
+	defer server.Close()
+
+	client := NewHTTPClient(server.URL, &HTTPClientConfig{Debug: true})
+
+	wg.Add(1)
+	client.Send(GETPayload)
+
+	wg.Wait()
+}
+
+func TestHTTPClientErrors(t *testing.T) {
+	req := []byte("GET http://foobar.com/path HTTP/1.0\r\n\r\n")
+
+	// Port not exists
+	client := NewHTTPClient("http://127.0.0.1:1", &HTTPClientConfig{Debug: true})
+	if resp, err := client.Send(req); err != nil {
+		if s := proto.Status(resp); !bytes.Equal(s, []byte("521")) {
+			t.Error("Should return status 521 for connection refused, instead:", string(s))
+		}
+	} else {
+		t.Error("Should throw error")
+	}
+
+	client = NewHTTPClient("http://not.existing", &HTTPClientConfig{Debug: true})
+	if resp, err := client.Send(req); err != nil {
+		if s := proto.Status(resp); !bytes.Equal(s, []byte("521")) {
+			t.Error("Should return status 521 for no such host, instead:", string(s))
+		}
+	} else {
+		t.Error("Should throw error")
+	}
+
+	// Non routable IP address to simulate connection timeout
+	client = NewHTTPClient("http://10.255.255.1", &HTTPClientConfig{Debug: true, ConnectionTimeout: 100 * time.Millisecond})
+
+	if resp, err := client.Send(req); err != nil {
+		if s := proto.Status(resp); !bytes.Equal(s, []byte("521")) {
+			t.Error("Should return status 521 for io/timeout:", string(s))
+		}
+	} else {
+		t.Error("Should throw error")
+	}
+
+	// Connecting but io timeout on read
+	ln, _ := net.Listen("tcp", "127.0.0.1:0")
+	client = NewHTTPClient("http://"+ln.Addr().String(), &HTTPClientConfig{Debug: true, Timeout: 10 * time.Millisecond})
+	defer ln.Close()
+
+	if resp, err := client.Send(req); err != nil {
+		if s := proto.Status(resp); !bytes.Equal(s, []byte("524")) {
+			t.Error("Should return status 524 for io read, instead:", string(s))
+		}
+	} else {
+		t.Error("Should throw error")
+	}
+
+	// Response read error read tcp [::1]:51128: connection reset by peer &{{0xc20802a000}}
+	ln1, _ := net.Listen("tcp", "127.0.0.1:0")
+	go func() {
+		ln1.Accept()
+	}()
+	defer ln1.Close()
+
+	client = NewHTTPClient("http://"+ln1.Addr().String(), &HTTPClientConfig{Debug: true, Timeout: 10 * time.Millisecond})
+
+	if resp, err := client.Send(req); err != nil {
+		if s := proto.Status(resp); !bytes.Equal(s, []byte("524")) {
+			t.Error("Should return status 524 for connection reset by peer, instead:", string(s))
+		}
+	} else {
+		t.Error("Should throw error")
+	}
+
+	ln2, _ := net.Listen("tcp", "127.0.0.1:0")
+	go func() {
+		buf := make([]byte, 64*1024)
+		conn, _ := ln2.Accept()
+
+		conn.Read(buf)
+		defer conn.Close()
+	}()
+	defer ln2.Close()
+
+	client = NewHTTPClient("http://"+ln2.Addr().String(), &HTTPClientConfig{Debug: true, Timeout: 10 * time.Millisecond})
+
+	if resp, err := client.Send(req); err != nil {
+		if s := proto.Status(resp); !bytes.Equal(s, []byte("524")) {
+			t.Error("Should return status 524 for connection reset by peer, instead:", string(s))
+		}
+	} else {
+		t.Error("Should throw error")
+	}
+}

http_modifier.go

@@ -0,0 +1,157 @@
+package main
+
+import (
+	"bytes"
+	"hash/fnv"
+
+	"github.com/buger/gor/proto"
+)
+
+type HTTPModifier struct {
+	config *HTTPModifierConfig
+}
+
+func NewHTTPModifier(config *HTTPModifierConfig) *HTTPModifier {
+	// Optimization to skip modifier completely if we do not need it
+	if len(config.urlRegexp) == 0 &&
+		len(config.urlNegativeRegexp) == 0 &&
+		len(config.urlRewrite) == 0 &&
+		len(config.headerFilters) == 0 &&
+		len(config.headerNegativeFilters) == 0 &&
+		len(config.headerHashFilters) == 0 &&
+		len(config.paramHashFilters) == 0 &&
+		len(config.params) == 0 &&
+		len(config.headers) == 0 &&
+		len(config.methods) == 0 {
+		return nil
+	}
+
+	return &HTTPModifier{config: config}
+}
+
+func (m *HTTPModifier) Rewrite(payload []byte) (response []byte) {
+	if !proto.IsHTTPPayload(payload) {
+		return payload
+	}
+
+	if len(m.config.methods) > 0 {
+		method := proto.Method(payload)
+
+		matched := false
+
+		for _, m := range m.config.methods {
+			if bytes.Equal(method, m) {
+				matched = true
+				break
+			}
+		}
+
+		if !matched {
+			return
+		}
+	}
+
+	if len(m.config.headers) > 0 {
+		for _, header := range m.config.headers {
+			payload = proto.SetHeader(payload, []byte(header.Name), []byte(header.Value))
+		}
+	}
+
+	if len(m.config.params) > 0 {
+		for _, param := range m.config.params {
+			payload = proto.SetPathParam(payload, param.Name, param.Value)
+		}
+	}
+
+	if len(m.config.urlRegexp) > 0 {
+		path := proto.Path(payload)
+
+		matched := false
+
+		for _, f := range m.config.urlRegexp {
+			if f.regexp.Match(path) {
+				matched = true
+				break
+			}
+		}
+
+		if !matched {
+			return
+		}
+	}
+
+	if len(m.config.urlNegativeRegexp) > 0 {
+		path := proto.Path(payload)
+
+		for _, f := range m.config.urlNegativeRegexp {
+			if f.regexp.Match(path) {
+				return
+			}
+		}
+	}
+
+	if len(m.config.headerFilters) > 0 {
+		for _, f := range m.config.headerFilters {
+			value := proto.Header(payload, f.name)
+
+			if len(value) > 0 && !f.regexp.Match(value) {
+				return
+			}
+		}
+	}
+
+	if len(m.config.headerNegativeFilters) > 0 {
+		for _, f := range m.config.headerNegativeFilters {
+			value := proto.Header(payload, f.name)
+
+			if len(value) > 0 && f.regexp.Match(value) {
+				return
+			}
+		}
+	}
+
+	if len(m.config.headerHashFilters) > 0 {
+		for _, f := range m.config.headerHashFilters {
+			value := proto.Header(payload, f.name)
+
+			if len(value) > 0 {
+				hasher := fnv.New32a()
+				hasher.Write(value)
+
+				if (hasher.Sum32() % 100) >= f.percent {
+					return
+				}
+			}
+		}
+	}
+
+	if len(m.config.paramHashFilters) > 0 {
+		for _, f := range m.config.paramHashFilters {
+			value, s, _ := proto.PathParam(payload, f.name)
+
+			if s != -1 {
+				hasher := fnv.New32a()
+				hasher.Write(value)
+
+				if (hasher.Sum32() % 100) >= f.percent {
+					return
+				}
+			}
+		}
+	}
+
+	if len(m.config.urlRewrite) > 0 {
+		path := proto.Path(payload)
+
+		for _, f := range m.config.urlRewrite {
+			if f.src.Match(path) {
+				path = f.src.ReplaceAll(path, f.target)
+				payload = proto.SetPath(payload, path)
+
+				break
+			}
+		}
+	}
+
+	return payload
+}

http_modifier_settings.go

@@ -0,0 +1,215 @@
+package main
+
+import (
+	"errors"
+	"fmt"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+// HTTPModifierConfig holds configuration options for built-in traffic modifier
+type HTTPModifierConfig struct {
+	urlNegativeRegexp     HTTPUrlRegexp
+	urlRegexp             HTTPUrlRegexp
+	urlRewrite            UrlRewriteMap
+	headerFilters         HTTPHeaderFilters
+	headerNegativeFilters HTTPHeaderFilters
+	headerHashFilters     HTTPHashFilters
+	paramHashFilters      HTTPHashFilters
+
+	params  HTTPParams
+	headers HTTPHeaders
+	methods HTTPMethods
+}
+
+//
+// Handling of --http-allow-header, --http-disallow-header options
+//
+type headerFilter struct {
+	name   []byte
+	regexp *regexp.Regexp
+}
+
+// HTTPHeaderFilters holds list of headers and their regexps
+type HTTPHeaderFilters []headerFilter
+
+func (h *HTTPHeaderFilters) String() string {
+	return fmt.Sprint(*h)
+}
+
+func (h *HTTPHeaderFilters) Set(value string) error {
+	valArr := strings.SplitN(value, ":", 2)
+	if len(valArr) < 2 {
+		return errors.New("need both header and value, colon-delimited (ex. user_id:^169$).")
+	}
+	r, err := regexp.Compile(valArr[1])
+	if err != nil {
+		return err
+	}
+
+	*h = append(*h, headerFilter{name: []byte(valArr[0]), regexp: r})
+
+	return nil
+}
+
+//
+// Handling of --http-allow-header-hash and --http-allow-param-hash options
+//
+type hashFilter struct {
+	name    []byte
+	percent uint32
+}
+
+type HTTPHashFilters []hashFilter
+
+func (h *HTTPHashFilters) String() string {
+	return fmt.Sprint(*h)
+}
+
+func (h *HTTPHashFilters) Set(value string) error {
+	valArr := strings.SplitN(value, ":", 2)
+	if len(valArr) < 2 {
+		return errors.New("need both header and value, colon-delimited (ex. user_id:50%)")
+	}
+
+	f := hashFilter{name: []byte(valArr[0])}
+
+	if strings.Contains(valArr[1], "%") {
+		p, _ := strconv.ParseInt(valArr[1][:len(valArr[1])-1], 0, 0)
+		f.percent = uint32(p)
+	} else if strings.Contains(valArr[1], "/") {
+		// DEPRECATED format
+		var num, den uint64
+
+		fracArr := strings.Split(valArr[1], "/")
+		num, _ = strconv.ParseUint(fracArr[0], 10, 64)
+		den, _ = strconv.ParseUint(fracArr[1], 10, 64)
+
+		f.percent = uint32((float64(num) / float64(den)) * 100)
+	} else {
+		return errors.New("Value should be percent and contain '%'")
+	}
+
+	*h = append(*h, f)
+
+	return nil
+}
+
+//
+// Handling of --http-set-header option
+//
+type HTTPHeaders []HTTPHeader
+type HTTPHeader struct {
+	Name  string
+	Value string
+}
+
+func (h *HTTPHeaders) String() string {
+	return fmt.Sprint(*h)
+}
+
+func (h *HTTPHeaders) Set(value string) error {
+	v := strings.SplitN(value, ":", 2)
+	if len(v) != 2 {
+		return errors.New("Expected `Key: Value`")
+	}
+
+	header := HTTPHeader{
+		strings.TrimSpace(v[0]),
+		strings.TrimSpace(v[1]),
+	}
+
+	*h = append(*h, header)
+	return nil
+}
+
+//
+// Handling of --http-set-param option
+//
+type HTTPParams []HTTPParam
+type HTTPParam struct {
+	Name  []byte
+	Value []byte
+}
+
+func (h *HTTPParams) String() string {
+	return fmt.Sprint(*h)
+}
+
+func (h *HTTPParams) Set(value string) error {
+	v := strings.SplitN(value, "=", 2)
+	if len(v) != 2 {
+		return errors.New("Expected `Key=Value`")
+	}
+
+	param := HTTPParam{
+		[]byte(strings.TrimSpace(v[0])),
+		[]byte(strings.TrimSpace(v[1])),
+	}
+
+	*h = append(*h, param)
+	return nil
+}
+
+//
+// Handling of --http-allow-method option
+//
+type HTTPMethods [][]byte
+
+func (h *HTTPMethods) String() string {
+	return fmt.Sprint(*h)
+}
+
+func (h *HTTPMethods) Set(value string) error {
+	*h = append(*h, []byte(value))
+	return nil
+}
+
+//
+// Handling of --http-rewrite-url option
+//
+type urlRewrite struct {
+	src    *regexp.Regexp
+	target []byte
+}
+
+type UrlRewriteMap []urlRewrite
+
+func (r *UrlRewriteMap) String() string {
+	return fmt.Sprint(*r)
+}
+
+func (r *UrlRewriteMap) Set(value string) error {
+	valArr := strings.SplitN(value, ":", 2)
+	if len(valArr) < 2 {
+		return errors.New("need both src and target, colon-delimited (ex. /a:/b)")
+	}
+	regexp, err := regexp.Compile(valArr[0])
+	if err != nil {
+		return err
+	}
+	*r = append(*r, urlRewrite{src: regexp, target: []byte(valArr[1])})
+	return nil
+}
+
+//
+// Handling of --http-allow-url option
+//
+type urlRegexp struct {
+	regexp *regexp.Regexp
+}
+
+type HTTPUrlRegexp []urlRegexp
+
+func (r *HTTPUrlRegexp) String() string {
+	return fmt.Sprint(*r)
+}
+
+func (r *HTTPUrlRegexp) Set(value string) error {
+	regexp, err := regexp.Compile(value)
+
+	*r = append(*r, urlRegexp{regexp: regexp})
+
+	return err
+}

http_modifier_settings_test.go

@@ -0,0 +1,65 @@
+package main
+
+import (
+	"testing"
+)
+
+func TestHTTPHeaderFilters(t *testing.T) {
+	filters := HTTPHeaderFilters{}
+
+	err := filters.Set("Header1:^$")
+	if err != nil {
+		t.Error("Should not error on Header1:^$")
+	}
+
+	err = filters.Set("Header2:^:$")
+	if err != nil {
+		t.Error("Should not error on Header2:^:$")
+	}
+
+	// Missing colon
+	err = filters.Set("Header3-^$")
+	if err == nil {
+		t.Error("Should error on Header2:^:$")
+	}
+}
+
+func TestHTTPHashFilters(t *testing.T) {
+	filters := HTTPHashFilters{}
+
+	err := filters.Set("Header1:1/2")
+	if err != nil {
+		t.Error("Should support old syntax")
+	}
+
+	if filters[0].percent != 50 {
+		t.Error("Wrong percentage", filters[0].percent)
+	}
+
+	err = filters.Set("Header2:1")
+	if err == nil {
+		t.Error("Should error on Header2 because no % symbol")
+	}
+
+	err = filters.Set("Header2:10%")
+	if err != nil {
+		t.Error("Should pass")
+	}
+
+	if filters[1].percent != 10 {
+		t.Error("Wrong percentage", filters[1].percent)
+	}
+}
+
+func TestUrlRewriteMap(t *testing.T) {
+	var err error
+	rewrites := UrlRewriteMap{}
+
+	if err = rewrites.Set("/v1/user/([^\\/]+)/ping:/v2/user/$1/ping"); err != nil {
+		t.Error("Should set mapping", err)
+	}
+
+	if err = rewrites.Set("/v1/user/([^\\/]+)/ping"); err == nil {
+		t.Error("Should not set mapping without :")
+	}
+}

http_modifier_test.go

@@ -0,0 +1,247 @@
+package main
+
+import (
+	"bytes"
+	"github.com/buger/gor/proto"
+	"testing"
+)
+
+func TestHTTPModifierWithoutConfig(t *testing.T) {
+	if NewHTTPModifier(&HTTPModifierConfig{}) != nil {
+		t.Error("If no config specified should not be initialized")
+	}
+}
+
+func TestHTTPModifierHeaderFilters(t *testing.T) {
+	filters := HTTPHeaderFilters{}
+	filters.Set("Host:^www.w3.org$")
+
+	modifier := NewHTTPModifier(&HTTPModifierConfig{
+		headerFilters: filters,
+	})
+
+	payload := []byte("POST /post HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+
+	if len(modifier.Rewrite(payload)) == 0 {
+		t.Error("Request should pass filters")
+	}
+
+	filters = HTTPHeaderFilters{}
+	// Setting filter that not match our header
+	filters.Set("Host:^www.w4.org$")
+
+	modifier = NewHTTPModifier(&HTTPModifierConfig{
+		headerFilters: filters,
+	})
+
+	if len(modifier.Rewrite(payload)) != 0 {
+		t.Error("Request should not pass filters")
+	}
+}
+
+func TestHTTPModifierHeaderNegativeFilters(t *testing.T) {
+	filters := HTTPHeaderFilters{}
+	filters.Set("Host:^www.w3.org$")
+
+	modifier := NewHTTPModifier(&HTTPModifierConfig{
+		headerNegativeFilters: filters,
+	})
+
+	payload := []byte("POST /post HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w4.org\r\n\r\na=1&b=2")
+
+	if len(modifier.Rewrite(payload)) == 0 {
+		t.Error("Request should pass filters")
+	}
+
+	filters = HTTPHeaderFilters{}
+	// Setting filter that not match our header
+	filters.Set("Host:^www.w4.org$")
+
+	modifier = NewHTTPModifier(&HTTPModifierConfig{
+		headerNegativeFilters: filters,
+	})
+
+	if len(modifier.Rewrite(payload)) != 0 {
+		t.Error("Request should not pass filters")
+	}
+}
+
+func TestHTTPModifierURLRewrite(t *testing.T) {
+	var url, newURL []byte
+
+	rewrites := UrlRewriteMap{}
+
+	payload := func(url []byte) []byte {
+		return []byte("POST " + string(url) + " HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+	}
+
+	err := rewrites.Set("/v1/user/([^\\/]+)/ping:/v2/user/$1/ping")
+	if err != nil {
+		t.Error("Should not error on /v1/user/([^\\/]+)/ping:/v2/user/$1/ping")
+	}
+
+	modifier := NewHTTPModifier(&HTTPModifierConfig{
+		urlRewrite: rewrites,
+	})
+
+	url = []byte("/v1/user/joe/ping")
+	if newURL = proto.Path(modifier.Rewrite(payload(url))); bytes.Equal(newURL, url) {
+		t.Error("Request url should have been rewritten, wasn't", string(newURL))
+	}
+
+	url = []byte("/v1/user/ping")
+	if newURL = proto.Path(modifier.Rewrite(payload(url))); !bytes.Equal(newURL, url) {
+		t.Error("Request url should have been rewritten, wasn't", string(newURL))
+	}
+}
+
+func TestHTTPModifierHeaderHashFilters(t *testing.T) {
+	filters := HTTPHashFilters{}
+	filters.Set("Header2:1/2")
+
+	modifier := NewHTTPModifier(&HTTPModifierConfig{
+		headerHashFilters: filters,
+	})
+
+	payload := func(header []byte) []byte {
+		return []byte("POST / HTTP/1.1\r\n" + string(header) + "Content-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+	}
+
+	if p := modifier.Rewrite(payload([]byte(""))); len(p) == 0 {
+		t.Error("Request should pass filters if Header does not exist")
+	}
+
+	if p := modifier.Rewrite(payload([]byte("Header2: 3\r\n"))); len(p) > 0 {
+		t.Error("Request should not pass filters, Header2 hash too high")
+	}
+
+	if p := modifier.Rewrite(payload([]byte("Header2: 1\r\n"))); len(p) == 0 {
+		t.Error("Request should pass filters")
+	}
+}
+
+func TestHTTPModifierParamHashFilters(t *testing.T) {
+	filters := HTTPHashFilters{}
+	filters.Set("user_id:1/2")
+
+	modifier := NewHTTPModifier(&HTTPModifierConfig{
+		paramHashFilters: filters,
+	})
+
+	payload := func(value []byte) []byte {
+		return []byte("POST /" + string(value) + " HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+	}
+
+	if p := modifier.Rewrite(payload([]byte(""))); len(p) == 0 {
+		t.Error("Request should pass filters if param does not exist")
+	}
+
+	if p := modifier.Rewrite(payload([]byte("?user_id=3"))); len(p) > 0 {
+		t.Error("Request should not pass filters", string(p))
+	}
+
+	if p := modifier.Rewrite(payload([]byte("?user_id=1"))); len(p) == 0 {
+		t.Error("Request should pass filters")
+	}
+}
+
+func TestHTTPModifierHeaders(t *testing.T) {
+	headers := HTTPHeaders{}
+	headers.Set("Header1:1")
+	headers.Set("Host:localhost")
+
+	modifier := NewHTTPModifier(&HTTPModifierConfig{
+		headers: headers,
+	})
+
+	payload := []byte("POST /post HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+	newPayload := []byte("POST /post HTTP/1.1\r\nHeader1: 1\r\nContent-Length: 7\r\nHost: localhost\r\n\r\na=1&b=2")
+
+	if payload = modifier.Rewrite(payload); !bytes.Equal(payload, newPayload) {
+		t.Error("Should update request headers", string(payload))
+	}
+}
+
+func TestHTTPModifierURLRegexp(t *testing.T) {
+	filters := HTTPUrlRegexp{}
+	filters.Set("/v1/app")
+	filters.Set("/v1/api")
+
+	modifier := NewHTTPModifier(&HTTPModifierConfig{
+		urlRegexp: filters,
+	})
+
+	payload := func(url string) []byte {
+		return []byte("POST " + url + " HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+	}
+
+	if len(modifier.Rewrite(payload("/v1/app/test"))) == 0 {
+		t.Error("Should pass url")
+	}
+
+	if len(modifier.Rewrite(payload("/v1/api/test"))) == 0 {
+		t.Error("Should pass url")
+	}
+
+	if len(modifier.Rewrite(payload("/other"))) > 0 {
+		t.Error("Should not pass url")
+	}
+}
+
+func TestHTTPModifierURLNegativeRegexp(t *testing.T) {
+	filters := HTTPUrlRegexp{}
+	filters.Set("/restricted1")
+	filters.Set("/some/restricted2")
+
+	modifier := NewHTTPModifier(&HTTPModifierConfig{
+		urlNegativeRegexp: filters,
+	})
+
+	payload := func(url string) []byte {
+		return []byte("POST " + url + " HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+	}
+
+	if len(modifier.Rewrite(payload("/v1/app/test"))) == 0 {
+		t.Error("Should pass url")
+	}
+
+	if len(modifier.Rewrite(payload("/restricted1"))) > 0 {
+		t.Error("Should not pass url")
+	}
+
+	if len(modifier.Rewrite(payload("/some/restricted2"))) > 0 {
+		t.Error("Should not pass url")
+	}
+}
+
+func TestHTTPModifierSetHeader(t *testing.T) {
+	filters := HTTPHeaders{}
+	filters.Set("User-Agent:Gor")
+
+	modifier := NewHTTPModifier(&HTTPModifierConfig{
+		headers: filters,
+	})
+
+	payload := []byte("POST /post HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+	payloadAfter := []byte("POST /post HTTP/1.1\r\nUser-Agent: Gor\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+
+	if payload = modifier.Rewrite(payload); !bytes.Equal(payloadAfter, payload) {
+		t.Error("Should add new header", string(payload))
+	}
+}
+
+func TestHTTPModifierSetParam(t *testing.T) {
+	filters := HTTPParams{}
+	filters.Set("api_key=1")
+
+	modifier := NewHTTPModifier(&HTTPModifierConfig{
+		params: filters,
+	})
+
+	payload := []byte("POST /post?api_key=1234 HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+	payloadAfter := []byte("POST /post?api_key=1 HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+
+	if payload = modifier.Rewrite(payload); !bytes.Equal(payloadAfter, payload) {
+		t.Error("Should override param", string(payload))
+	}
+}

input_dummy.go

@@ -1,13 +1,15 @@
-package gor
+package main
 
 import (
 	"time"
 )
 
+// DummyInput used for debugging. It generate 1 "GET /"" request per second.
 type DummyInput struct {
 	data chan []byte
 }
 
+// NewDummyInput constructor for DummyInput
 func NewDummyInput(options string) (di *DummyInput) {
 	di = new(DummyInput)
 	di.data = make(chan []byte)
@@ -19,6 +21,7 @@ func NewDummyInput(options string) (di *DummyInput) {
 
 func (i *DummyInput) Read(data []byte) (int, error) {
 	buf := <-i.data
+
 	copy(data, buf)
 
 	return len(buf), nil
@@ -30,7 +33,12 @@ func (i *DummyInput) emit() {
 	for {
 		select {
 		case <-ticker.C:
-			i.data <- []byte("GET / HTTP/1.1\r\n\r\n")
+			uuid := uuid()
+			reqh := payloadHeader(RequestPayload, uuid, time.Now().UnixNano())
+			i.data <- append(reqh, []byte("GET /HTTP/1.1\r\nHost: www.w3.org\r\nUser-Agent: Go 1.1 package http\r\nAccept-Encoding: gzip\r\n\r\n")...)
+
+			resh := payloadHeader(ResponsePayload, uuid, 1)
+			i.data <- append(resh, []byte("HTTP/1.1 200 OK\r\nContent-Length: 0\r\n\r\n")...)
 		}
 	}
 }

input_file.go

@@ -1,37 +1,44 @@
-package gor
+package main
 
 import (
-	"encoding/gob"
+	"bufio"
+	"bytes"
+	"io"
 	"log"
 	"os"
+	"strconv"
 	"time"
 )
 
+// FileInput can read requests generated by FileOutput
 type FileInput struct {
-	data    chan []byte
-	path    string
-	decoder *gob.Decoder
+	data        chan []byte
+	path        string
+	file        *os.File
+	speedFactor float64
 }
 
+// NewFileInput constructor for FileInput. Accepts file path as argument.
 func NewFileInput(path string) (i *FileInput) {
 	i = new(FileInput)
 	i.data = make(chan []byte)
 	i.path = path
-	i.Init(path)
+	i.speedFactor = 1
+	i.init(path)
 
 	go i.emit()
 
 	return
 }
 
-func (i *FileInput) Init(path string) {
+func (i *FileInput) init(path string) {
 	file, err := os.Open(path)
 
 	if err != nil {
 		log.Fatal(i, "Cannot open file %q. Error: %s", path, err)
 	}
 
-	i.decoder = gob.NewDecoder(file)
+	i.file = file
 }
 
 func (i *FileInput) Read(data []byte) (int, error) {
@@ -48,19 +55,53 @@ func (i *FileInput) String() string {
 func (i *FileInput) emit() {
 	var lastTime int64
 
+	payloadSeparatorAsBytes := []byte(payloadSeparator)
+	reader := bufio.NewReader(i.file)
+	var buffer bytes.Buffer
+
 	for {
-		raw := new(RawRequest)
-		err := i.decoder.Decode(raw)
+		line, err := reader.ReadBytes('\n')
 
 		if err != nil {
-			return
+			if err != io.EOF {
+				log.Fatal(err)
+			}
+			break
+
 		}
 
-		if lastTime != 0 {
-			time.Sleep(time.Duration(raw.Timestamp - lastTime))
-			lastTime = raw.Timestamp
+		if bytes.Equal(payloadSeparatorAsBytes[1:], line) {
+			asBytes := buffer.Bytes()[:buffer.Len()-1]
+			buffer.Reset()
+
+			meta := payloadMeta(asBytes)
+
+			if len(meta) > 2 && meta[0][0] == RequestPayload {
+				ts, _ := strconv.ParseInt(string(meta[2]), 10, 64)
+
+				if lastTime != 0 {
+					timeDiff := ts - lastTime
+
+					if i.speedFactor != 1 {
+						timeDiff = int64(float64(timeDiff) / i.speedFactor)
+					}
+
+					time.Sleep(time.Duration(timeDiff))
+				}
+
+				lastTime = ts
+			}
+
+			// Bytes() returns only pointer, so to remove data-race copy the data to an array
+			newBuf := make([]byte, len(asBytes))
+			copy(newBuf, asBytes)
+
+			i.data <- newBuf
+		} else {
+			buffer.Write(line)
 		}
 
-		i.data <- raw.Request
 	}
+
+	log.Printf("FileInput: end of file '%s'\n", i.path)
 }

input_file_test.go

@@ -0,0 +1,220 @@
+package main
+
+import (
+	"bytes"
+	"errors"
+	"io"
+	"io/ioutil"
+	"os"
+	"sync"
+	"syscall"
+	"testing"
+	"time"
+)
+
+func TestInputFileWithGET(t *testing.T) {
+
+	input := NewTestInput()
+	rg := NewRequestGenerator([]io.Reader{input}, func() { input.EmitGET() }, 1)
+	readPayloads := [][]byte{}
+
+	// Given a capture file with a GET request
+	expectedCaptureFile := CreateCaptureFile(rg)
+	defer expectedCaptureFile.TearDown()
+
+	// When the request is read from the capture file
+	err := ReadFromCaptureFile(expectedCaptureFile.file, 1, func(data []byte) {
+		readPayloads = append(readPayloads, Duplicate(data))
+	})
+
+	// The read request should match the original request
+	if err != nil {
+		t.Error(err)
+	} else {
+		if !expectedCaptureFile.PayloadsEqual(readPayloads) {
+			t.Error("Request read back from file should match")
+		}
+	}
+
+}
+
+func TestInputFileWithPayloadLargerThan64Kb(t *testing.T) {
+
+	input := NewTestInput()
+	rg := NewRequestGenerator([]io.Reader{input}, func() { input.EmitSizedPOST(64 * 1024) }, 1)
+	readPayloads := [][]byte{}
+
+	// Given a capture file with a request over 64Kb
+	expectedCaptureFile := CreateCaptureFile(rg)
+	defer expectedCaptureFile.TearDown()
+
+	// When the request is read from the capture file
+	err := ReadFromCaptureFile(expectedCaptureFile.file, 1, func(data []byte) {
+		readPayloads = append(readPayloads, Duplicate(data))
+	})
+
+	// The read request should match the original request
+	if err != nil {
+		t.Error(err)
+	} else {
+		if !expectedCaptureFile.PayloadsEqual(readPayloads) {
+			t.Error("Request read back from file should match")
+		}
+	}
+
+}
+
+func TestInputFileWithGETAndPOST(t *testing.T) {
+
+	input := NewTestInput()
+	rg := NewRequestGenerator([]io.Reader{input}, func() {
+		input.EmitGET()
+		input.EmitPOST()
+	}, 2)
+	readPayloads := [][]byte{}
+
+	// Given a capture file with a GET request
+	expectedCaptureFile := CreateCaptureFile(rg)
+	defer expectedCaptureFile.TearDown()
+
+	// When the requests are read from the capture file
+	err := ReadFromCaptureFile(expectedCaptureFile.file, 2, func(data []byte) {
+		readPayloads = append(readPayloads, Duplicate(data))
+	})
+
+	// The read requests should match the original request
+	if err != nil {
+		t.Error(err)
+	} else {
+		if !expectedCaptureFile.PayloadsEqual(readPayloads) {
+			t.Error("Request read back from file should match")
+		}
+	}
+
+}
+
+type CaptureFile struct {
+	data [][]byte
+	file *os.File
+}
+
+func NewExpectedCaptureFile(data [][]byte, file *os.File) *CaptureFile {
+	ecf := new(CaptureFile)
+	ecf.file = file
+	ecf.data = data
+	return ecf
+}
+
+func (expectedCaptureFile *CaptureFile) TearDown() {
+	if expectedCaptureFile.file != nil {
+		syscall.Unlink(expectedCaptureFile.file.Name())
+	}
+}
+
+type RequestGenerator struct {
+	inputs []io.Reader
+	emit   func()
+	wg     *sync.WaitGroup
+}
+
+func NewRequestGenerator(inputs []io.Reader, emit func(), count int) (rg *RequestGenerator) {
+	rg = new(RequestGenerator)
+	rg.inputs = inputs
+	rg.emit = emit
+	rg.wg = new(sync.WaitGroup)
+	rg.wg.Add(count)
+	return
+}
+
+func (expectedCaptureFile *CaptureFile) PayloadsEqual(other [][]byte) bool {
+
+	if len(expectedCaptureFile.data) != len(other) {
+		return false
+	}
+
+	for i, payload := range other {
+
+		if !bytes.Equal(expectedCaptureFile.data[i], payload) {
+			return false
+		}
+
+	}
+
+	return true
+
+}
+
+func CreateCaptureFile(requestGenerator *RequestGenerator) *CaptureFile {
+
+	f, err := ioutil.TempFile("", "testmainconf")
+	if err != nil {
+		panic(err)
+	}
+
+	quit := make(chan int)
+
+	readPayloads := [][]byte{}
+	output := NewTestOutput(func(data []byte) {
+
+		readPayloads = append(readPayloads, Duplicate(data))
+
+		requestGenerator.wg.Done()
+	})
+
+	outputFile := NewFileOutput(f.Name())
+
+	Plugins.Inputs = requestGenerator.inputs
+	Plugins.Outputs = []io.Writer{output, outputFile}
+
+	go Start(quit)
+
+	requestGenerator.emit()
+	requestGenerator.wg.Wait()
+
+	close(quit)
+
+	return NewExpectedCaptureFile(readPayloads, f)
+
+}
+
+func ReadFromCaptureFile(captureFile *os.File, count int, callback writeCallback) (err error) {
+
+	quit := make(chan int)
+	wg := new(sync.WaitGroup)
+
+	input := NewFileInput(captureFile.Name())
+	output := NewTestOutput(func(data []byte) {
+		callback(data)
+		wg.Done()
+	})
+
+	Plugins.Inputs = []io.Reader{input}
+	Plugins.Outputs = []io.Writer{output}
+
+	wg.Add(count)
+	go Start(quit)
+
+	done := make(chan int, 1)
+	go func() {
+		wg.Wait()
+		done <- 1
+	}()
+
+	select {
+	case <-done:
+		break
+	case <-time.After(2 * time.Second):
+		err = errors.New("Timed out")
+	}
+	close(quit)
+
+	return
+
+}
+
+func Duplicate(data []byte) (duplicate []byte) {
+	duplicate = make([]byte, len(data))
+	copy(duplicate, data)
+
+	return
+}

input_http.go

@@ -0,0 +1,76 @@
+package main
+
+import (
+	"log"
+	"net"
+	"net/http"
+	"net/http/httputil"
+	"time"
+)
+
+// HTTPInput used for sending requests to Gor via http
+type HTTPInput struct {
+	data     chan []byte
+	address  string
+	listener net.Listener
+}
+
+// NewHTTPInput constructor for HTTPInput. Accepts address with port which he will listen on.
+func NewHTTPInput(address string) (i *HTTPInput) {
+	i = new(HTTPInput)
+	i.data = make(chan []byte, 10000)
+	i.address = address
+
+	i.listen(address)
+
+	return
+}
+
+func (i *HTTPInput) Read(data []byte) (int, error) {
+	buf := <-i.data
+
+	header := payloadHeader(RequestPayload, uuid(), time.Now().UnixNano())
+
+	copy(data[0:len(header)], header)
+	copy(data[len(header):], buf)
+
+	return len(buf) + len(header), nil
+}
+
+func (i *HTTPInput) handler(w http.ResponseWriter, r *http.Request) {
+	r.URL.Scheme = "http"
+	r.URL.Host = i.listener.Addr().String()
+
+	buf, _ := httputil.DumpRequestOut(r, true)
+	http.Error(w, http.StatusText(200), 200)
+
+	select {
+	case i.data <- buf:
+	default:
+		Debug("[INPUT-HTTP] Dropping requests because output can't process them fast enough")
+	}
+}
+
+func (i *HTTPInput) listen(address string) {
+	var err error
+
+	mux := http.NewServeMux()
+
+	mux.HandleFunc("/", i.handler)
+
+	i.listener, err = net.Listen("tcp", address)
+	if err != nil {
+		log.Fatal("HTTP input listener failure:", err)
+	}
+
+	go func() {
+		err = http.Serve(i.listener, mux)
+		if err != nil {
+			log.Fatal("HTTP input serve failure:", err)
+		}
+	}()
+}
+
+func (i *HTTPInput) String() string {
+	return "HTTP input: " + i.address
+}

input_http_test.go

@@ -0,0 +1,73 @@
+package main
+
+import (
+	"github.com/buger/gor/proto"
+	"io"
+	"log"
+	"net/http"
+	"os/exec"
+	"strings"
+	"sync"
+	"testing"
+)
+
+func TestHTTPInput(t *testing.T) {
+	wg := new(sync.WaitGroup)
+	quit := make(chan int)
+
+	input := NewHTTPInput("127.0.0.1:0")
+	output := NewTestOutput(func(data []byte) {
+		wg.Done()
+	})
+
+	Plugins.Inputs = []io.Reader{input}
+	Plugins.Outputs = []io.Writer{output}
+
+	go Start(quit)
+
+	address := strings.Replace(input.listener.Addr().String(), "[::]", "127.0.0.1", -1)
+
+	for i := 0; i < 100; i++ {
+		wg.Add(1)
+		http.Get("http://" + address + "/")
+	}
+
+	wg.Wait()
+
+	close(quit)
+}
+
+func TestInputHTTPLargePayload(t *testing.T) {
+	wg := new(sync.WaitGroup)
+	quit := make(chan int)
+
+	// Generate 1000kb file
+	dd := exec.Command("dd", "if=/dev/urandom", "of=/tmp/large", "bs=1MB", "count=4")
+	err := dd.Run()
+	if err != nil {
+		log.Fatal("dd error:", err)
+	}
+
+	input := NewHTTPInput("127.0.0.1:0")
+	output := NewTestOutput(func(data []byte) {
+		if len(proto.Body(payloadBody(data))) != 4000000 {
+			t.Error("Should receive full file")
+		}
+		wg.Done()
+	})
+	Plugins.Inputs = []io.Reader{input}
+	Plugins.Outputs = []io.Writer{output}
+
+	go Start(quit)
+
+	wg.Add(1)
+	address := strings.Replace(input.listener.Addr().String(), "[::]", "127.0.0.1", -1)
+	curl := exec.Command("curl", "http://"+address, "--data-binary", "@/tmp/large")
+	err = curl.Run()
+	if err != nil {
+		log.Fatal("curl error:", err)
+	}
+
+	wg.Wait()
+	close(quit)
+}

input_raw.go

@@ -1,21 +1,37 @@
-package gor
+package main
 
 import (
 	raw "github.com/buger/gor/raw_socket_listener"
 	"log"
 	"net"
 	"strings"
+	"time"
 )
 
+// RAWInput used for intercepting traffic for given address
 type RAWInput struct {
-	data    chan []byte
-	address string
+	data     chan *raw.TCPMessage
+	address  string
+	expire   time.Duration
+	quit     chan bool
+	engine   int
+	listener *raw.Listener
 }
 
-func NewRAWInput(address string) (i *RAWInput) {
+// Available engines for intercepting traffic
+const (
+	EngineRawSocket = 1 << iota
+	EnginePcap
+)
+
+// NewRAWInput constructor for RAWInput. Accepts address with port as argument.
+func NewRAWInput(address string, engine int, expire time.Duration) (i *RAWInput) {
 	i = new(RAWInput)
-	i.data = make(chan []byte)
+	i.data = make(chan *raw.TCPMessage)
 	i.address = address
+	i.expire = expire
+	i.engine = engine
+	i.quit = make(chan bool)
 
 	go i.listen(address)
 
@@ -23,31 +39,55 @@ func NewRAWInput(address string) (i *RAWInput) {
 }
 
 func (i *RAWInput) Read(data []byte) (int, error) {
-	buf := <-i.data
-	copy(data, buf)
+	msg := <-i.data
+	buf := msg.Bytes()
 
-	return len(buf), nil
+	var header []byte
+
+	if msg.IsIncoming {
+		header = payloadHeader(RequestPayload, msg.UUID(), msg.Start.UnixNano())
+	} else {
+		header = payloadHeader(ResponsePayload, msg.UUID(), msg.End.UnixNano()-msg.RequestStart.UnixNano())
+	}
+
+	copy(data[0:len(header)], header)
+	copy(data[len(header):], buf)
+
+	return len(buf) + len(header), nil
 }
 
 func (i *RAWInput) listen(address string) {
 	address = strings.Replace(address, "[::]", "127.0.0.1", -1)
 
+	Debug("Listening for traffic on: " + address)
+
 	host, port, err := net.SplitHostPort(address)
 
 	if err != nil {
 		log.Fatal("input-raw: error while parsing address", err)
 	}
 
-	listener := raw.NewListener(host, port)
+	i.listener = raw.NewListener(host, port, i.engine, i.expire)
 
 	for {
-		// Receiving TCPMessage object
-		m := listener.Receive()
+		select {
+		case <-i.quit:
+			return
+		default:
+		}
 
-		i.data <- m.Bytes()
+		// Receiving TCPMessage object
+		m := i.listener.Receive()
+
+		i.data <- m
 	}
 }
 
 func (i *RAWInput) String() string {
-	return "RAW Socket input: " + i.address
+	return "Intercepting traffic from: " + i.address
+}
+
+func (i *RAWInput) Close() {
+	i.listener.Close()
+	close(i.quit)
 }

input_raw_test.go

@@ -1,39 +1,310 @@
-package gor
+package main
 
 import (
+	"bytes"
 	"io"
+	"io/ioutil"
+	"log"
+	"math/rand"
 	"net/http"
+	"net/http/httptest"
+	"net/http/httputil"
+	"os"
+	"os/exec"
+	"strconv"
 	"strings"
 	"sync"
+	"sync/atomic"
 	"testing"
+	"time"
 )
 
-func TestRAWInput(t *testing.T) {
+const testRawExpire = time.Millisecond * 200
 
+func TestRAWInput(t *testing.T) {
 	wg := new(sync.WaitGroup)
 	quit := make(chan int)
 
-	listener := startHTTP(func(req *http.Request) {})
+	origin := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {}))
+	defer origin.Close()
+	originAddr := strings.Replace(origin.Listener.Addr().String(), "[::]", "127.0.0.1", -1)
+
+	var respCounter, reqCounter int64
+
+	input := NewRAWInput(originAddr, EnginePcap, testRawExpire)
+	defer input.Close()
 
-	input := NewRAWInput(listener.Addr().String())
 	output := NewTestOutput(func(data []byte) {
+		if data[0] == '1' {
+			atomic.AddInt64(&reqCounter, 1)
+		} else {
+			atomic.AddInt64(&respCounter, 1)
+		}
+
+		if Settings.debug {
+			log.Println(reqCounter, respCounter)
+		}
+
 		wg.Done()
 	})
 
 	Plugins.Inputs = []io.Reader{input}
 	Plugins.Outputs = []io.Writer{output}
 
-	address := strings.Replace(listener.Addr().String(), "[::]", "127.0.0.1", -1)
+	client := NewHTTPClient(origin.URL, &HTTPClientConfig{})
 
 	go Start(quit)
+	time.Sleep(100 * time.Millisecond)
 
 	for i := 0; i < 100; i++ {
-		wg.Add(1)
-		res, _ := http.Get("http://" + address)
-		res.Body.Close()
+		// request + response
+		wg.Add(2)
+		client.Get("/")
+		time.Sleep(2 * time.Millisecond)
+	}
+
+	wg.Wait()
+	close(quit)
+}
+
+func TestInputRAW100Expect(t *testing.T) {
+	wg := new(sync.WaitGroup)
+	quit := make(chan int)
+
+	fileContent, _ := ioutil.ReadFile("COMM-LICENSE")
+
+	// Origing and Replay server initialization
+	origin := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		defer r.Body.Close()
+		ioutil.ReadAll(r.Body)
+		wg.Done()
+	}))
+	defer origin.Close()
+
+	originAddr := strings.Replace(origin.Listener.Addr().String(), "[::]", "127.0.0.1", -1)
+
+	input := NewRAWInput(originAddr, EnginePcap, time.Second)
+	defer input.Close()
+
+	// We will use it to get content of raw HTTP request
+	testOutput := NewTestOutput(func(data []byte) {
+		switch data[0] {
+		case RequestPayload:
+			if strings.Contains(string(data), "Expect: 100-continue") {
+				t.Error("Should not contain 100-continue header")
+			}
+			wg.Done()
+		case ResponsePayload:
+			wg.Done()
+		}
+	})
+
+	replay := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		defer r.Body.Close()
+		body, _ := ioutil.ReadAll(r.Body)
+
+		if !bytes.Equal(body, fileContent) {
+			buf, _ := httputil.DumpRequest(r, true)
+			t.Error("Wrong POST body:", string(buf))
+		}
+
+		wg.Done()
+	}))
+	defer replay.Close()
+
+	httpOutput := NewHTTPOutput(replay.URL, &HTTPOutputConfig{})
+
+	Plugins.Inputs = []io.Reader{input}
+	Plugins.Outputs = []io.Writer{testOutput, httpOutput}
+
+	go Start(quit)
+	time.Sleep(100 * time.Millisecond)
+
+	// Origin + Response/Request Test Output + Request Http Output
+	wg.Add(4)
+	curl := exec.Command("curl", "http://"+originAddr, "--data-binary", "@COMM-LICENSE")
+	err := curl.Run()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	wg.Wait()
+	close(quit)
+}
+
+func TestInputRAWChunkedEncoding(t *testing.T) {
+	wg := new(sync.WaitGroup)
+	quit := make(chan int)
+
+	fileContent, _ := ioutil.ReadFile("README.md")
+
+	// Origing and Replay server initialization
+	origin := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		defer r.Body.Close()
+		ioutil.ReadAll(r.Body)
+
+		wg.Done()
+	}))
+
+	originAddr := strings.Replace(origin.Listener.Addr().String(), "[::]", "127.0.0.1", -1)
+	input := NewRAWInput(originAddr, EnginePcap, time.Second)
+	defer input.Close()
+
+	replay := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		defer r.Body.Close()
+		body, _ := ioutil.ReadAll(r.Body)
+
+		if !bytes.Equal(body, fileContent) {
+			buf, _ := httputil.DumpRequest(r, true)
+			t.Error("Wrong POST body:", string(buf))
+		}
+
+		wg.Done()
+	}))
+	defer replay.Close()
+
+	httpOutput := NewHTTPOutput(replay.URL, &HTTPOutputConfig{Debug: true})
+
+	Plugins.Inputs = []io.Reader{input}
+	Plugins.Outputs = []io.Writer{httpOutput}
+
+	go Start(quit)
+	time.Sleep(100 * time.Millisecond)
+
+	wg.Add(2)
+
+	curl := exec.Command("curl", "http://"+originAddr, "--header", "Transfer-Encoding: chunked", "--header", "Expect:", "--data-binary", "@README.md")
+	err := curl.Run()
+	if err != nil {
+		log.Fatal(err)
 	}
 
 	wg.Wait()
 
 	close(quit)
 }
+
+func TestInputRAWLargePayload(t *testing.T) {
+	// FIXME: Large payloads does not work for travis for some reason...
+	if os.Getenv("TRAVIS_BUILD_DIR") != "" {
+		return
+	}
+	wg := new(sync.WaitGroup)
+	quit := make(chan int)
+	sizeKb := 100
+
+	// Generate 100kb file
+	dd := exec.Command("dd", "if=/dev/urandom", "of=/tmp/large", "bs=1KB", "count="+strconv.Itoa(sizeKb))
+	err := dd.Run()
+	if err != nil {
+		log.Fatal("dd error:", err)
+	}
+
+	origin := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
+		defer req.Body.Close()
+		body, _ := ioutil.ReadAll(req.Body)
+
+		if len(body) != sizeKb*1000 {
+			t.Error("File size should be 1mb:", len(body))
+		}
+
+		wg.Done()
+	}))
+	originAddr := strings.Replace(origin.Listener.Addr().String(), "[::]", "127.0.0.1", -1)
+
+	input := NewRAWInput(originAddr, EnginePcap, testRawExpire)
+	defer input.Close()
+
+	replay := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
+		body, _ := ioutil.ReadAll(req.Body)
+		// // req.Body = http.MaxBytesReader(w, req.Body, 1*1024*1024)
+		// // buf := make([]byte, 1*1024*1024)
+		// n, _ := req.Body.Read(buf)
+		// body := buf[0:n]
+
+		if len(body) != sizeKb*1000 {
+			t.Errorf("File size should be %d bytes: %d", sizeKb*1000, len(body))
+		}
+
+		wg.Done()
+	}))
+	defer replay.Close()
+
+	httpOutput := NewHTTPOutput(replay.URL, &HTTPOutputConfig{Debug: false})
+
+	Plugins.Inputs = []io.Reader{input}
+	Plugins.Outputs = []io.Writer{httpOutput}
+
+	go Start(quit)
+
+	time.Sleep(100 * time.Millisecond)
+
+	wg.Add(2)
+	curl := exec.Command("curl", "http://"+originAddr, "--header", "Transfer-Encoding: chunked", "--header", "Expect:", "--data-binary", "@/tmp/large")
+	err = curl.Run()
+	if err != nil {
+		log.Fatal("curl error:", err)
+	}
+
+	wg.Wait()
+	close(quit)
+}
+
+func BenchmarkRAWInput(b *testing.B) {
+	quit := make(chan int)
+
+	origin := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {}))
+	defer origin.Close()
+	originAddr := strings.Replace(origin.Listener.Addr().String(), "[::]", "127.0.0.1", -1)
+
+	var respCounter, reqCounter int64
+
+	input := NewRAWInput(originAddr, EnginePcap, testRawExpire)
+	defer input.Close()
+
+	output := NewTestOutput(func(data []byte) {
+		if data[0] == '1' {
+			atomic.AddInt64(&reqCounter, 1)
+		} else {
+			atomic.AddInt64(&respCounter, 1)
+		}
+
+		// log.Println("Captured ", reqCounter, "requests and ", respCounter, " responses")
+	})
+
+	Plugins.Inputs = []io.Reader{input}
+	Plugins.Outputs = []io.Writer{output}
+
+	time.Sleep(time.Millisecond)
+
+	go Start(quit)
+
+	emitted := 0
+	fileContent, _ := ioutil.ReadFile("LICENSE.txt")
+
+	for i := 0; i < b.N; i++ {
+		wg := new(sync.WaitGroup)
+		wg.Add(10 * 100)
+		emitted += 10 * 100
+		for w := 0; w < 100; w++ {
+			go func() {
+				client := NewHTTPClient(origin.URL, &HTTPClientConfig{})
+				for i := 0; i < 10; i++ {
+					if rand.Int63n(2) == 0 {
+						client.Post("/", fileContent)
+					} else {
+						client.Get("/")
+					}
+					time.Sleep(time.Duration(rand.Int63n(50)) * time.Millisecond)
+					wg.Done()
+				}
+			}()
+		}
+		wg.Wait()
+	}
+
+	time.Sleep(400 * time.Millisecond)
+	log.Println("Emitted ", emitted, ", Captured ", reqCounter, "requests and ", respCounter, " responses")
+
+	close(quit)
+}

input_tcp.go

@@ -1,21 +1,21 @@
-package gor
+package main
 
 import (
 	"bufio"
-	"bytes"
+	"fmt"
 	"log"
 	"net"
+	"os"
 )
 
-// Can be tested using nc tool:
-//    echo "asdad" | nc 127.0.0.1 27017
-//
+// TCPInput used for internal communication
 type TCPInput struct {
 	data     chan []byte
 	address  string
 	listener net.Listener
 }
 
+// NewTCPInput constructor for TCPInput, accepts address with port
 func NewTCPInput(address string) (i *TCPInput) {
 	i = new(TCPInput)
 	i.data = make(chan []byte)
@@ -55,36 +55,20 @@ func (i *TCPInput) listen(address string) {
 	}()
 }
 
-func scanBytes(data []byte, atEOF bool) (advance int, token []byte, err error) {
-	if atEOF && len(data) == 0 {
-		return 0, nil, nil
-	}
-
-	// Search for ¶ symbol
-	if i := bytes.IndexByte(data, 194); i >= 0 {
-		if len(data) > i+1 && data[i+1] == 182 {
-			// We have a full newline-terminated line.
-			return i + 2, data[0:i], nil
-		}
-	}
-	// If we're at EOF, we have a final, non-terminated line. Return it.
-	if atEOF {
-		return len(data), data, nil
-	}
-	// Request more data.
-	return 0, nil, nil
-}
-
 func (i *TCPInput) handleConnection(conn net.Conn) {
 	defer conn.Close()
 
-	scanner := bufio.NewScanner(conn)
-
-	scanner.Split(scanBytes)
+	reader := bufio.NewReader(conn)
+	scanner := bufio.NewScanner(reader)
+	scanner.Split(payloadScanner)
 
 	for scanner.Scan() {
 		i.data <- scanner.Bytes()
 	}
+
+	if err := scanner.Err(); err != nil {
+		fmt.Fprintln(os.Stderr, "Unexpected error in input tcp connection:", err)
+	}
 }
 
 func (i *TCPInput) String() string {

input_tcp_test.go

@@ -1,4 +1,4 @@
-package gor
+package main
 
 import (
 	"io"
@@ -12,7 +12,7 @@ func TestTCPInput(t *testing.T) {
 	wg := new(sync.WaitGroup)
 	quit := make(chan int)
 
-	input := NewTCPInput(":0")
+	input := NewTCPInput("127.0.0.1:0")
 	output := NewTestOutput(func(data []byte) {
 		wg.Done()
 	})
@@ -34,12 +34,12 @@ func TestTCPInput(t *testing.T) {
 		log.Fatal(err)
 	}
 
-	msg := []byte("GET / HTTP/1.1\r\n\r\n")
+	msg := []byte("1 1 1\nGET / HTTP/1.1\r\n\r\n")
 
 	for i := 0; i < 100; i++ {
 		wg.Add(1)
 		conn.Write(msg)
-		conn.Write([]byte("¶"))
+		conn.Write([]byte(payloadSeparator))
 	}
 
 	wg.Wait()
@@ -51,7 +51,7 @@ func BenchmarkTCPInput(b *testing.B) {
 	wg := new(sync.WaitGroup)
 	quit := make(chan int)
 
-	input := NewTCPInput(":0")
+	input := NewTCPInput("127.0.0.1:0")
 	output := NewTestOutput(func(data []byte) {
 		wg.Done()
 	})
@@ -80,8 +80,10 @@ func BenchmarkTCPInput(b *testing.B) {
 			for {
 				data := <-dataChan
 
-				conn.Write(data)
-				conn.Write([]byte("¶"))
+				buf := make([]byte, len(data)+2)
+				data = append(data, []byte("¶")...)
+				copy(buf, data)
+				conn.Write(buf)
 			}
 		}(conn)
 	}

limiter.go

@@ -1,45 +1,96 @@
-package gor
+package main
 
 import (
 	"fmt"
 	"io"
+	"math/rand"
+	"strconv"
+	"strings"
 	"time"
 )
 
+// Limiter is a wrapper for input or output plugin which adds rate limiting
 type Limiter struct {
-	writer io.Writer
-	limit  int
+	plugin    interface{}
+	limit     int
+	isPercent bool
 
 	currentRPS  int
 	currentTime int64
 }
 
-func NewLimiter(writer io.Writer, limit int) (l *Limiter) {
-	l = new(Limiter)
-	l.limit = limit
-	l.writer = writer
-	l.currentTime = time.Now().UnixNano()
+func parseLimitOptions(options string) (limit int, isPercent bool) {
+	if strings.Contains(options, "%") {
+		limit, _ = strconv.Atoi(strings.Split(options, "%")[0])
+		isPercent = true
+	} else {
+		limit, _ = strconv.Atoi(options)
+		isPercent = false
+	}
 
 	return
 }
 
-func (l *Limiter) Write(data []byte) (n int, err error) {
+// NewLimiter constructor for Limiter, accepts plugin and options
+// `options` allow to sprcify relatve or absolute limiting
+func NewLimiter(plugin interface{}, options string) io.ReadWriter {
+	l := new(Limiter)
+	l.limit, l.isPercent = parseLimitOptions(options)
+	l.plugin = plugin
+	l.currentTime = time.Now().UnixNano()
+
+	// FileInput have its own rate limiting. Unlike other inputs we not just dropping requests, we can slow down or speed up request emittion.
+	if fi, ok := l.plugin.(*FileInput); ok && l.isPercent {
+		fi.speedFactor = float64(l.limit) / float64(100)
+	}
+
+	return l
+}
+
+func (l *Limiter) isLimited() bool {
+	// File input have its own limiting algorithm
+	if _, ok := l.plugin.(*FileInput); ok && l.isPercent {
+		return false
+	}
+
+	if l.isPercent {
+		return l.limit <= rand.Intn(100)
+	}
+
 	if (time.Now().UnixNano() - l.currentTime) > time.Second.Nanoseconds() {
 		l.currentTime = time.Now().UnixNano()
 		l.currentRPS = 0
 	}
 
 	if l.currentRPS >= l.limit {
+		return true
+	}
+
+	l.currentRPS++
+
+	return false
+}
+
+func (l *Limiter) Write(data []byte) (n int, err error) {
+	if l.isLimited() {
 		return 0, nil
 	}
 
-	n, err = l.writer.Write(data)
+	n, err = l.plugin.(io.Writer).Write(data)
 
-	l.currentRPS++
+	return
+}
+
+func (l *Limiter) Read(data []byte) (n int, err error) {
+	n, err = l.plugin.(io.Reader).Read(data)
+
+	if l.isLimited() {
+		return 0, nil
+	}
 
 	return
 }
 
 func (l *Limiter) String() string {
-	return fmt.Sprintf("Limiting %s to: %d", l.writer, l.limit)
+	return fmt.Sprintf("Limiting %s to: %d (isPercent: %b)", l.plugin, l.limit, l.isPercent)
 }

limiter_test.go

@@ -1,4 +1,6 @@
-package gor
+// +build !race
+
+package main
 
 import (
 	"io"
@@ -6,14 +8,14 @@ import (
 	"testing"
 )
 
-func TestLimiter(t *testing.T) {
+func TestOutputLimiter(t *testing.T) {
 	wg := new(sync.WaitGroup)
 	quit := make(chan int)
 
 	input := NewTestInput()
 	output := NewLimiter(NewTestOutput(func(data []byte) {
 		wg.Done()
-	}), 10)
+	}), "10")
 	wg.Add(10)
 
 	Plugins.Inputs = []io.Reader{input}
@@ -29,3 +31,76 @@ func TestLimiter(t *testing.T) {
 
 	close(quit)
 }
+
+func TestInputLimiter(t *testing.T) {
+	wg := new(sync.WaitGroup)
+	quit := make(chan int)
+
+	input := NewLimiter(NewTestInput(), "10")
+	output := NewTestOutput(func(data []byte) {
+		wg.Done()
+	})
+	wg.Add(10)
+
+	Plugins.Inputs = []io.Reader{input}
+	Plugins.Outputs = []io.Writer{output}
+
+	go Start(quit)
+
+	for i := 0; i < 100; i++ {
+		input.(*Limiter).plugin.(*TestInput).EmitGET()
+	}
+
+	wg.Wait()
+
+	close(quit)
+}
+
+// Should limit all requests
+func TestPercentLimiter1(t *testing.T) {
+	wg := new(sync.WaitGroup)
+	quit := make(chan int)
+
+	input := NewTestInput()
+	output := NewLimiter(NewTestOutput(func(data []byte) {
+		wg.Done()
+	}), "0%")
+
+	Plugins.Inputs = []io.Reader{input}
+	Plugins.Outputs = []io.Writer{output}
+
+	go Start(quit)
+
+	for i := 0; i < 100; i++ {
+		input.EmitGET()
+	}
+
+	wg.Wait()
+
+	close(quit)
+}
+
+// Should not limit at all
+func TestPercentLimiter2(t *testing.T) {
+	wg := new(sync.WaitGroup)
+	quit := make(chan int)
+
+	input := NewTestInput()
+	output := NewLimiter(NewTestOutput(func(data []byte) {
+		wg.Done()
+	}), "100%")
+	wg.Add(100)
+
+	Plugins.Inputs = []io.Reader{input}
+	Plugins.Outputs = []io.Writer{output}
+
+	go Start(quit)
+
+	for i := 0; i < 100; i++ {
+		input.EmitGET()
+	}
+
+	wg.Wait()
+
+	close(quit)
+}

middleware.go

@@ -0,0 +1,125 @@
+package main
+
+import (
+	"bufio"
+	"encoding/hex"
+	"fmt"
+	"io"
+	"log"
+	"os"
+	"os/exec"
+	"strings"
+	"sync"
+)
+
+type Middleware struct {
+	command string
+
+	data chan []byte
+
+	mu sync.Mutex
+
+	Stdin  io.Writer
+	Stdout io.Reader
+}
+
+func NewMiddleware(command string) *Middleware {
+	m := new(Middleware)
+	m.command = command
+	m.data = make(chan []byte, 1000)
+
+	commands := strings.Split(command, " ")
+	cmd := exec.Command(commands[0], commands[1:]...)
+
+	m.Stdout, _ = cmd.StdoutPipe()
+	m.Stdin, _ = cmd.StdinPipe()
+
+	if Settings.verbose {
+		cmd.Stderr = os.Stderr
+	}
+
+	go m.read(m.Stdout)
+
+	go func() {
+		err := cmd.Start()
+
+		if err != nil {
+			log.Fatal(err)
+		}
+
+		err = cmd.Wait()
+
+		if err != nil {
+			log.Fatal(err)
+		}
+	}()
+
+	return m
+}
+
+func (m *Middleware) ReadFrom(plugin io.Reader) {
+	Debug("[MIDDLEWARE-MASTER] Starting reading from", plugin)
+	go m.copy(m.Stdin, plugin)
+}
+
+func (m *Middleware) copy(to io.Writer, from io.Reader) {
+	buf := make([]byte, 5*1024*1024)
+	dst := make([]byte, len(buf)*2)
+
+	for {
+		nr, _ := from.Read(buf)
+		if nr > 0 && len(buf) > nr {
+
+			hex.Encode(dst, buf[0:nr])
+			dst[nr*2] = '\n'
+
+			m.mu.Lock()
+			to.Write(dst[0 : nr*2+1])
+			m.mu.Unlock()
+
+			if Settings.debug {
+				Debug("[MIDDLEWARE-MASTER] Sending:", string(buf[0:nr]), "From:", from)
+			}
+		}
+	}
+}
+
+func (m *Middleware) read(from io.Reader) {
+	reader := bufio.NewReader(from)
+	var line []byte
+	var e error
+
+	for {
+		if line, e = reader.ReadBytes('\n'); e != nil {
+			if e == io.EOF {
+				continue
+			} else {
+				break
+			}
+		}
+
+		buf := make([]byte, len(line)/2)
+		if _, err := hex.Decode(buf, line[:len(line)-1]); err != nil {
+			fmt.Fprintln(os.Stderr, "Failed to decode input payload", err, len(line))
+		}
+
+		if Settings.debug {
+			Debug("[MIDDLEWARE-MASTER] Received:", string(buf))
+		}
+
+		m.data <- buf
+	}
+
+	return
+}
+
+func (m *Middleware) Read(data []byte) (int, error) {
+	buf := <-m.data
+	copy(data, buf)
+
+	return len(buf), nil
+}
+
+func (m *Middleware) String() string {
+	return fmt.Sprintf("Modifying traffic using '%s' command", m.command)
+}

middleware_test.go

@@ -0,0 +1,220 @@
+package main
+
+import (
+	"bytes"
+	"crypto/rand"
+	"encoding/hex"
+	"github.com/buger/gor/proto"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"sync"
+	"testing"
+	"time"
+)
+
+type fakeServiceCb func(string, int, []byte)
+
+// Simple service that generate token on request, and require this token for accesing to secure area
+func NewFakeSecureService(wg *sync.WaitGroup, cb fakeServiceCb) *httptest.Server {
+	active_tokens := make([]string, 0)
+	var mu sync.Mutex
+
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
+		mu.Lock()
+		defer mu.Unlock()
+		Debug("Received request: " + req.URL.String())
+
+		switch req.URL.Path {
+		case "/token":
+			// Generate random token
+			token_length := 10
+			buf := make([]byte, token_length)
+			rand.Read(buf)
+			token := hex.EncodeToString(buf)
+			active_tokens = append(active_tokens, token)
+
+			w.Write([]byte(token))
+
+			cb(req.URL.Path, 200, []byte(token))
+		case "/secure":
+			token := req.URL.Query().Get("token")
+			token_found := false
+
+			for _, t := range active_tokens {
+				if t == token {
+					token_found = true
+					break
+				}
+			}
+
+			if token_found {
+				w.WriteHeader(http.StatusAccepted)
+				cb(req.URL.Path, 202, []byte(nil))
+			} else {
+				w.WriteHeader(http.StatusForbidden)
+				cb(req.URL.Path, 403, []byte(nil))
+			}
+		}
+
+		wg.Done()
+	}))
+
+	return server
+}
+
+func TestFakeSecureService(t *testing.T) {
+	var resp, token []byte
+
+	wg := new(sync.WaitGroup)
+
+	server := NewFakeSecureService(wg, func(path string, status int, resp []byte) {
+	})
+	defer server.Close()
+
+	wg.Add(3)
+
+	client := NewHTTPClient(server.URL, &HTTPClientConfig{Debug: true})
+	resp, _ = client.Get("/token")
+	token = proto.Body(resp)
+
+	// Right token
+	resp, _ = client.Get("/secure?token=" + string(token))
+	if !bytes.Equal(proto.Status(resp), []byte("202")) {
+		t.Error("Valid token should return status 202:", string(proto.Status(resp)))
+	}
+
+	// Wrong tokens forbidden
+	resp, _ = client.Get("/secure?token=wrong")
+	if !bytes.Equal(proto.Status(resp), []byte("403")) {
+		t.Error("Wrong token should returns status 403:", string(proto.Status(resp)))
+	}
+
+	wg.Wait()
+}
+
+func TestEchoMiddleware(t *testing.T) {
+	wg := new(sync.WaitGroup)
+
+	from := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Env", "prod")
+		w.Header().Set("RequestPath", r.URL.Path)
+		wg.Done()
+	}))
+	defer from.Close()
+
+	to := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Env", "test")
+		w.Header().Set("RequestPath", r.URL.Path)
+		wg.Done()
+	}))
+	defer to.Close()
+
+	quit := make(chan int)
+
+	Settings.middleware = "./examples/middleware/echo.sh"
+
+	// Catch traffic from one service
+	fromAddr := strings.Replace(from.Listener.Addr().String(), "[::]", "127.0.0.1", -1)
+	input := NewRAWInput(fromAddr, EnginePcap, testRawExpire)
+	defer input.Close()
+
+	// And redirect to another
+	output := NewHTTPOutput(to.URL, &HTTPOutputConfig{Debug: false})
+
+	Plugins.Inputs = []io.Reader{input}
+	Plugins.Outputs = []io.Writer{output}
+
+	// Start Gor
+	go Start(quit)
+
+	// Wait till middleware initialization
+	time.Sleep(100 * time.Millisecond)
+
+	// Should receive 2 requests from original + 2 from replayed
+	client := NewHTTPClient(from.URL, &HTTPClientConfig{Debug: false})
+
+	for i := 0; i < 10; i++ {
+		wg.Add(4)
+		// Request should be echoed
+		client.Get("/a")
+		time.Sleep(5 * time.Millisecond)
+		client.Get("/b")
+		time.Sleep(5 * time.Millisecond)
+	}
+
+	wg.Wait()
+	close(quit)
+	time.Sleep(200 * time.Millisecond)
+
+	Settings.middleware = ""
+}
+
+func TestTokenMiddleware(t *testing.T) {
+	var resp, token []byte
+
+	wg := new(sync.WaitGroup)
+
+	from := NewFakeSecureService(wg, func(path string, status int, tok []byte) {
+		time.Sleep(10 * time.Millisecond)
+	})
+	defer from.Close()
+
+	to := NewFakeSecureService(wg, func(path string, status int, tok []byte) {
+		switch path {
+		case "/secure":
+			if status != 202 {
+				t.Error("Server should receive valid rewritten token")
+			}
+		}
+
+		time.Sleep(10 * time.Millisecond)
+	})
+	defer to.Close()
+
+	quit := make(chan int)
+
+	Settings.middleware = "go run ./examples/middleware/token_modifier.go"
+
+	fromAddr := strings.Replace(from.Listener.Addr().String(), "[::]", "127.0.0.1", -1)
+	// Catch traffic from one service
+	input := NewRAWInput(fromAddr, EnginePcap, testRawExpire)
+	defer input.Close()
+
+	// And redirect to another
+	output := NewHTTPOutput(to.URL, &HTTPOutputConfig{Debug: true})
+
+	Plugins.Inputs = []io.Reader{input}
+	Plugins.Outputs = []io.Writer{output}
+
+	// Start Gor
+	go Start(quit)
+
+	// Wait for middleware to initialize
+	// Give go compiller time to build programm
+	time.Sleep(500 * time.Millisecond)
+
+	// Should receive 2 requests from original + 2 from replayed
+	wg.Add(4)
+
+	client := NewHTTPClient(from.URL, &HTTPClientConfig{Debug: true})
+
+	// Sending traffic to original service
+	resp, _ = client.Get("/token")
+	token = proto.Body(resp)
+
+	// When delay is too smal, middleware does not always rewrite requests in time
+	// Hopefuly client will have delay more then 100ms :)
+	time.Sleep(100 * time.Millisecond)
+
+	resp, _ = client.Get("/secure?token=" + string(token))
+	if !bytes.Equal(proto.Status(resp), []byte("202")) {
+		t.Error("Valid token should return 202:", proto.Status(resp))
+	}
+
+	wg.Wait()
+	close(quit)
+	time.Sleep(100 * time.Millisecond)
+	Settings.middleware = ""
+}

output_dummy.go

@@ -1,12 +1,14 @@
-package gor
+package main
 
 import (
 	"fmt"
 )
 
+// DummyOutput used for debugging, prints all incoming requests
 type DummyOutput struct {
 }
 
+// NewDummyOutput constructor for DummyOutput
 func NewDummyOutput(options string) (di *DummyOutput) {
 	di = new(DummyOutput)
 
@@ -14,7 +16,7 @@ func NewDummyOutput(options string) (di *DummyOutput) {
 }
 
 func (i *DummyOutput) Write(data []byte) (int, error) {
-	fmt.Println("Writing message: ", data)
+	fmt.Println("Writing message: ", string(data))
 
 	return len(data), nil
 }

output_file.go

@@ -1,32 +1,27 @@
-package gor
+package main
 
 import (
-	"encoding/gob"
+	"io"
 	"log"
 	"os"
-	"time"
 )
 
-type RawRequest struct {
-	Timestamp int64
-	Request   []byte
-}
-
+// FileOutput output plugin
 type FileOutput struct {
-	path    string
-	encoder *gob.Encoder
-	file    *os.File
+	path string
+	file *os.File
 }
 
-func NewFileOutput(path string) (o *FileOutput) {
-	o = new(FileOutput)
+// NewFileOutput constructor for FileOutput, accepts path
+func NewFileOutput(path string) io.Writer {
+	o := new(FileOutput)
 	o.path = path
-	o.Init(path)
+	o.init(path)
 
-	return
+	return o
 }
 
-func (o *FileOutput) Init(path string) {
+func (o *FileOutput) init(path string) {
 	var err error
 
 	o.file, err = os.OpenFile(path, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0660)
@@ -34,14 +29,15 @@ func (o *FileOutput) Init(path string) {
 	if err != nil {
 		log.Fatal(o, "Cannot open file %q. Error: %s", path, err)
 	}
-
-	o.encoder = gob.NewEncoder(o.file)
 }
 
 func (o *FileOutput) Write(data []byte) (n int, err error) {
-	raw := RawRequest{time.Now().UnixNano(), data}
+	if !isOriginPayload(data) {
+		return len(data), nil
+	}
 
-	o.encoder.Encode(raw)
+	o.file.Write(data)
+	o.file.Write([]byte(payloadSeparator))
 
 	return len(data), nil
 }

output_file_test.go

@@ -1,4 +1,4 @@
-package gor
+package main
 
 import (
 	"io"

output_http.go

@@ -1,144 +1,209 @@
-package gor
+package main
 
 import (
-	"bufio"
-	"bytes"
-	es "github.com/buger/gor/elasticsearch"
+	"github.com/buger/gor/proto"
 	"io"
-	"log"
-	"net/http"
-	"net/url"
-	"strconv"
-	"strings"
+	"sync/atomic"
 	"time"
 )
 
-type RedirectNotAllowed struct{}
+const initialDynamicWorkers = 10
 
-func (e *RedirectNotAllowed) Error() string {
-	return "Redirects not allowed"
+type response struct {
+	payload       []byte
+	uuid          []byte
+	roundTripTime int64
 }
 
-// customCheckRedirect disables redirects https://github.com/buger/gor/pull/15
-func customCheckRedirect(req *http.Request, via []*http.Request) error {
-	if len(via) >= 0 {
-		return new(RedirectNotAllowed)
-	}
-	return nil
-}
+// HTTPOutputConfig struct for holding http output configuration
+type HTTPOutputConfig struct {
+	redirectLimit int
 
-// ParseRequest in []byte returns a http request or an error
-func ParseRequest(data []byte) (request *http.Request, err error) {
-	buf := bytes.NewBuffer(data)
-	reader := bufio.NewReader(buf)
+	stats   bool
+	workers int
 
-	request, err = http.ReadRequest(reader)
+	elasticSearch string
 
-	return
+	Timeout      time.Duration
+	OriginalHost bool
+
+	Debug bool
+
+	TrackResponses bool
 }
 
+// HTTPOutput plugin manage pool of workers which send request to replayed server
+// By default workers pool is dynamic and starts with 10 workers
+// You can specify fixed number of workers using `--output-http-workers`
 type HTTPOutput struct {
+	// Keep this as first element of struct because it guarantees 64bit
+	// alignment. atomic.* functions crash on 32bit machines if operand is not
+	// aligned at 64bit. See https://github.com/golang/go/issues/599
+	activeWorkers int64
+
 	address string
 	limit   int
-	buf     chan []byte
+	queue   chan []byte
 
-	headers HTTPHeaders
-	methods HTTPMethods
+	responses chan response
 
-	elasticSearch *es.ESPlugin
+	needWorker chan int
+
+	config *HTTPOutputConfig
+
+	queueStats *GorStat
+
+	elasticSearch *ESPlugin
 }
 
-func NewHTTPOutput(options string, headers HTTPHeaders, methods HTTPMethods, elasticSearchAddr string) io.Writer {
+// NewHTTPOutput constructor for HTTPOutput
+// Initialize workers
+func NewHTTPOutput(address string, config *HTTPOutputConfig) io.Writer {
 	o := new(HTTPOutput)
 
-	optionsArr := strings.Split(options, "|")
-	address := optionsArr[0]
-
-	if !strings.HasPrefix(address, "http") {
-		address = "http://" + address
-	}
-
 	o.address = address
-	o.headers = headers
-	o.methods = methods
+	o.config = config
 
-	o.buf = make(chan []byte, 100)
-
-	if elasticSearchAddr != "" {
-		o.elasticSearch = new(es.ESPlugin)
-		o.elasticSearch.Init(elasticSearchAddr)
+	if o.config.stats {
+		o.queueStats = NewGorStat("output_http")
 	}
 
-	if len(optionsArr) > 1 {
-		o.limit, _ = strconv.Atoi(optionsArr[1])
-	}
+	o.queue = make(chan []byte, 1000)
+	o.responses = make(chan response, 1000)
+	o.needWorker = make(chan int, 1)
 
-	for i := 0; i < 10; i++ {
-		go o.worker(i)
-	}
-
-	if o.limit > 0 {
-		return NewLimiter(o, o.limit)
+	// Initial workers count
+	if o.config.workers == 0 {
+		o.needWorker <- initialDynamicWorkers
 	} else {
-		return o
+		o.needWorker <- o.config.workers
+	}
+
+	if o.config.elasticSearch != "" {
+		o.elasticSearch = new(ESPlugin)
+		o.elasticSearch.Init(o.config.elasticSearch)
+	}
+
+	if len(Settings.middleware) > 0 {
+		o.config.TrackResponses = true
+	}
+
+	go o.workerMaster()
+
+	return o
+}
+
+func (o *HTTPOutput) workerMaster() {
+	for {
+		newWorkers := <-o.needWorker
+		for i := 0; i < newWorkers; i++ {
+			go o.startWorker()
+		}
+
+		// Disable dynamic scaling if workers poll fixed size
+		if o.config.workers != 0 {
+			return
+		}
 	}
 }
 
-func (o *HTTPOutput) worker(n int) {
-	client := &http.Client{
-		CheckRedirect: customCheckRedirect,
-	}
+func (o *HTTPOutput) startWorker() {
+	client := NewHTTPClient(o.address, &HTTPClientConfig{
+		FollowRedirects: o.config.redirectLimit,
+		Debug:           o.config.Debug,
+		OriginalHost:    o.config.OriginalHost,
+		Timeout:         o.config.Timeout,
+	})
+
+	deathCount := 0
+
+	atomic.AddInt64(&o.activeWorkers, 1)
 
 	for {
-		data := <-o.buf
-		o.sendRequest(client, data)
+		select {
+		case data := <-o.queue:
+			o.sendRequest(client, data)
+			deathCount = 0
+		case <-time.After(time.Millisecond * 100):
+			// When dynamic scaling enabled workers die after 2s of inactivity
+			if o.config.workers == 0 {
+				deathCount++
+			} else {
+				continue
+			}
+
+			if deathCount > 20 {
+				workersCount := atomic.LoadInt64(&o.activeWorkers)
+
+				// At least 1 startWorker should be alive
+				if workersCount != 1 {
+					atomic.AddInt64(&o.activeWorkers, -1)
+					return
+				}
+			}
+		}
 	}
 }
 
 func (o *HTTPOutput) Write(data []byte) (n int, err error) {
+	if !isRequestPayload(data) {
+		return len(data), nil
+	}
+
 	buf := make([]byte, len(data))
 	copy(buf, data)
 
-	o.buf <- buf
+	o.queue <- buf
+
+	if o.config.stats {
+		o.queueStats.Write(len(o.queue))
+	}
+
+	if o.config.workers == 0 {
+		workersCount := atomic.LoadInt64(&o.activeWorkers)
+
+		if len(o.queue) > int(workersCount) {
+			o.needWorker <- len(o.queue)
+		}
+	}
 
 	return len(data), nil
 }
 
-func (o *HTTPOutput) sendRequest(client *http.Client, data []byte) {
-	request, err := ParseRequest(data)
+func (o *HTTPOutput) Read(data []byte) (int, error) {
+	resp := <-o.responses
 
-	if err != nil {
-		log.Println("Can not parse request", string(data), err)
+	Debug("[OUTPUT-HTTP] Received response:", string(resp.payload))
+
+	header := payloadHeader(ReplayedResponsePayload, resp.uuid, resp.roundTripTime)
+	copy(data[0:len(header)], header)
+	copy(data[len(header):], resp.payload)
+
+	return len(resp.payload) + len(header), nil
+}
+
+func (o *HTTPOutput) sendRequest(client *HTTPClient, request []byte) {
+	meta := payloadMeta(request)
+	if len(meta) < 2 {
 		return
 	}
+	uuid := meta[1]
 
-	if len(o.methods) > 0 && !o.methods.Contains(request.Method) {
+	body := payloadBody(request)
+	if !proto.IsHTTPPayload(body) {
 		return
 	}
-	
-	// Change HOST of original request
-	URL := o.address + request.URL.Path + "?" + request.URL.RawQuery
-
-	request.RequestURI = ""
-	request.URL, _ = url.ParseRequestURI(URL)
-
-	for _, header := range o.headers {
-		request.Header.Set(header.Name, header.Value)
-	}
 
 	start := time.Now()
-	resp, err := client.Do(request)
+	resp, err := client.Send(body)
 	stop := time.Now()
 
-	// We should not count Redirect as errors
-	if _, ok := err.(*RedirectNotAllowed); ok {
-		err = nil
+	if err != nil {
+		Debug("Request error:", err)
 	}
 
-	if err == nil {
-		defer resp.Body.Close()
-	} else {
-		log.Println("Request error:", err)
+	if o.config.TrackResponses {
+		o.responses <- response{resp, uuid, stop.UnixNano() - start.UnixNano()}
 	}
 
 	if o.elasticSearch != nil {

output_http_test.go

@@ -1,36 +1,23 @@
-package gor
+package main
 
 import (
 	"io"
-	"net"
+	"io/ioutil"
 	"net/http"
+	"net/http/httptest"
+	_ "net/http/httputil"
 	"sync"
 	"testing"
 	"time"
 )
 
-func startHTTP(cb func(*http.Request)) net.Listener {
-	handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		go cb(r)
-	})
-
-	listener, _ := net.Listen("tcp", ":0")
-
-	go http.Serve(listener, handler)
-
-	return listener
-}
-
 func TestHTTPOutput(t *testing.T) {
 	wg := new(sync.WaitGroup)
 	quit := make(chan int)
 
 	input := NewTestInput()
 
-	headers := HTTPHeaders{HTTPHeader{"User-Agent", "Gor"}}
-	methods := HTTPMethods{"GET", "PUT", "POST"}
-
-	listener := startHTTP(func(req *http.Request) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
 		if req.Header.Get("User-Agent") != "Gor" {
 			t.Error("Wrong header")
 		}
@@ -39,10 +26,24 @@ func TestHTTPOutput(t *testing.T) {
 			t.Error("Wrong method")
 		}
 
-		wg.Done()
-	})
+		if req.Method == "POST" {
+			defer req.Body.Close()
+			body, _ := ioutil.ReadAll(req.Body)
 
-	output := NewHTTPOutput(listener.Addr().String(), headers, methods, "")
+			if string(body) != "a=1&b=2" {
+				t.Error("Wrong POST body:", string(body))
+			}
+		}
+
+		wg.Done()
+	}))
+	defer server.Close()
+
+	headers := HTTPHeaders{HTTPHeader{"User-Agent", "Gor"}}
+	methods := HTTPMethods{[]byte("GET"), []byte("PUT"), []byte("POST")}
+	Settings.modifierConfig = HTTPModifierConfig{headers: headers, methods: methods}
+
+	output := NewHTTPOutput(server.URL, &HTTPOutputConfig{Debug: true})
 
 	Plugins.Inputs = []io.Reader{input}
 	Plugins.Outputs = []io.Writer{output}
@@ -50,7 +51,7 @@ func TestHTTPOutput(t *testing.T) {
 	go Start(quit)
 
 	for i := 0; i < 100; i++ {
-		wg.Add(2)
+		wg.Add(2) // OPTIONS should be ignored
 		input.EmitPOST()
 		input.EmitOPTIONS()
 		input.EmitGET()
@@ -59,23 +60,83 @@ func TestHTTPOutput(t *testing.T) {
 	wg.Wait()
 
 	close(quit)
+
+	Settings.modifierConfig = HTTPModifierConfig{}
+}
+
+func TestHTTPOutputKeepOriginalHost(t *testing.T) {
+	wg := new(sync.WaitGroup)
+	quit := make(chan int)
+
+	input := NewTestInput()
+
+	server := httptest.NewTLSServer(http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
+		if req.Host != "custom-host.com" {
+			t.Error("Wrong header", req.Host)
+		}
+
+		wg.Done()
+	}))
+	defer server.Close()
+
+	headers := HTTPHeaders{HTTPHeader{"Host", "custom-host.com"}}
+	Settings.modifierConfig = HTTPModifierConfig{headers: headers}
+
+	output := NewHTTPOutput(server.URL, &HTTPOutputConfig{Debug: false, OriginalHost: true})
+
+	Plugins.Inputs = []io.Reader{input}
+	Plugins.Outputs = []io.Writer{output}
+
+	go Start(quit)
+
+	wg.Add(1)
+	input.EmitGET()
+
+	wg.Wait()
+
+	close(quit)
+
+	Settings.modifierConfig = HTTPModifierConfig{}
+}
+
+func TestOutputHTTPSSL(t *testing.T) {
+	wg := new(sync.WaitGroup)
+	quit := make(chan int)
+
+	// Origing and Replay server initialization
+	server := httptest.NewTLSServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		wg.Done()
+	}))
+
+	input := NewTestInput()
+	output := NewHTTPOutput(server.URL, &HTTPOutputConfig{})
+
+	Plugins.Inputs = []io.Reader{input}
+	Plugins.Outputs = []io.Writer{output}
+
+	go Start(quit)
+
+	wg.Add(2)
+
+	input.EmitPOST()
+	input.EmitGET()
+
+	wg.Wait()
+	close(quit)
 }
 
 func BenchmarkHTTPOutput(b *testing.B) {
 	wg := new(sync.WaitGroup)
 	quit := make(chan int)
 
-	input := NewTestInput()
-
-	headers := HTTPHeaders{HTTPHeader{"User-Agent", "Gor"}}
-	methods := HTTPMethods{"GET", "PUT", "POST"}
-
-	listener := startHTTP(func(req *http.Request) {
+	server := httptest.NewTLSServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		time.Sleep(50 * time.Millisecond)
 		wg.Done()
-	})
+	}))
+	defer server.Close()
 
-	output := NewHTTPOutput(listener.Addr().String(), headers, methods, "")
+	input := NewTestInput()
+	output := NewHTTPOutput(server.URL, &HTTPOutputConfig{})
 
 	Plugins.Inputs = []io.Reader{input}
 	Plugins.Outputs = []io.Writer{output}

output_tcp.go

@@ -1,55 +1,76 @@
-package gor
+package main
 
 import (
 	"fmt"
 	"io"
 	"log"
 	"net"
-	"strconv"
-	"strings"
+	"time"
 )
 
+// TCPOutput used for sending raw tcp payloads
+// Currently used for internal communication between listener and replay server
+// Can be used for transfering binary payloads like protocol buffers
 type TCPOutput struct {
-	address string
-	limit   int
-	buf     chan []byte
+	address  string
+	limit    int
+	buf      chan []byte
+	bufStats *GorStat
 }
 
-func NewTCPOutput(options string) io.Writer {
+// NewTCPOutput constructor for TCPOutput
+// Initialize 10 workers which hold keep-alive connection
+func NewTCPOutput(address string) io.Writer {
 	o := new(TCPOutput)
 
-	optionsArr := strings.Split(options, "|")
-	o.address = optionsArr[0]
+	o.address = address
 
 	o.buf = make(chan []byte, 100)
-
-	if len(optionsArr) > 1 {
-		o.limit, _ = strconv.Atoi(optionsArr[1])
+	if Settings.outputTCPStats {
+		o.bufStats = NewGorStat("output_tcp")
 	}
 
 	for i := 0; i < 10; i++ {
 		go o.worker()
 	}
 
-	if o.limit > 0 {
-		return NewLimiter(o, o.limit)
-	} else {
-		return o
-	}
+	return o
 }
 
 func (o *TCPOutput) worker() {
-	conn, _ := o.connect(o.address)
+	conn, err := o.connect(o.address)
+	for ; err != nil; conn, err = o.connect(o.address) {
+		time.Sleep(2 * time.Second)
+	}
+
 	defer conn.Close()
 
 	for {
 		conn.Write(<-o.buf)
-		conn.Write([]byte("¶"))
+		_, err := conn.Write([]byte(payloadSeparator))
+
+		if err != nil {
+			log.Println("Worker failed on write, exitings and starting new worker:", err)
+			go o.worker()
+			break
+		}
 	}
 }
 
 func (o *TCPOutput) Write(data []byte) (n int, err error) {
-	o.buf <- data
+	if !isOriginPayload(data) {
+		return len(data), nil
+	}
+
+	// We have to copy, because sending data in multiple threads
+	newBuf := make([]byte, len(data))
+	copy(newBuf, data)
+
+	o.buf <- newBuf
+
+	if Settings.outputTCPStats {
+		o.bufStats.Write(len(o.buf))
+	}
 
 	return len(data), nil
 }

output_tcp_test.go

@@ -1,4 +1,4 @@
-package gor
+package main
 
 import (
 	"bufio"
@@ -35,7 +35,7 @@ func TestTCPOutput(t *testing.T) {
 }
 
 func startTCP(cb func([]byte)) net.Listener {
-	listener, err := net.Listen("tcp", ":0")
+	listener, err := net.Listen("tcp", "127.0.0.1:0")
 
 	if err != nil {
 		log.Fatal("Can't start:", err)
@@ -44,17 +44,16 @@ func startTCP(cb func([]byte)) net.Listener {
 	go func() {
 		for {
 			conn, _ := listener.Accept()
+			defer conn.Close()
 
 			go func() {
-				scanner := bufio.NewScanner(conn)
-
-				scanner.Split(scanBytes)
+				reader := bufio.NewReader(conn)
+				scanner := bufio.NewScanner(reader)
+				scanner.Split(payloadScanner)
 
 				for scanner.Scan() {
 					cb(scanner.Bytes())
 				}
-
-				conn.Close()
 			}()
 		}
 	}()

plugins.go

@@ -1,46 +1,123 @@
-package gor
+package main
 
 import (
 	"io"
+	"reflect"
+	"strings"
+	"time"
 )
 
+// InOutPlugins struct for holding references to plugins
 type InOutPlugins struct {
 	Inputs  []io.Reader
 	Outputs []io.Writer
 }
 
+// Plugins holds all the plugin objects
 var Plugins *InOutPlugins = new(InOutPlugins)
 
+// extractLimitOptions detects if plugin get called with limiter support
+// Returns address and limit
+func extractLimitOptions(options string) (string, string) {
+	split := strings.Split(options, "|")
+
+	if len(split) > 1 {
+		return split[0], split[1]
+	}
+
+	return split[0], ""
+}
+
+// Automatically detects type of plugin and initialize it
+//
+// See this article if curious about relfect stuff below: http://blog.burntsushi.net/type-parametric-functions-golang
+func registerPlugin(constructor interface{}, options ...interface{}) {
+	vc := reflect.ValueOf(constructor)
+
+	// Pre-processing options to make it work with reflect
+	vo := []reflect.Value{}
+	for _, oi := range options {
+		vo = append(vo, reflect.ValueOf(oi))
+	}
+
+	// Removing limit options from path
+	path, limit := extractLimitOptions(vo[0].String())
+
+	// Writing value back without limiter "|" options
+	vo[0] = reflect.ValueOf(path)
+
+	// Calling our constructor with list of given options
+	plugin := vc.Call(vo)[0].Interface()
+	pluginWrapper := plugin
+
+	if limit != "" {
+		pluginWrapper = NewLimiter(plugin, limit)
+	} else {
+		pluginWrapper = plugin
+	}
+
+	_, isR := plugin.(io.Reader)
+	_, isW := plugin.(io.Writer)
+
+	// Some of the output can be Readers as well because return responses
+	if isR && !isW {
+		Plugins.Inputs = append(Plugins.Inputs, pluginWrapper.(io.Reader))
+	}
+
+	if isW {
+		Plugins.Outputs = append(Plugins.Outputs, pluginWrapper.(io.Writer))
+	}
+}
+
+// InitPlugins specify and initialize all available plugins
 func InitPlugins() {
 	for _, options := range Settings.inputDummy {
-		Plugins.Inputs = append(Plugins.Inputs, NewDummyInput(options))
+		registerPlugin(NewDummyInput, options)
 	}
 
 	for _, options := range Settings.outputDummy {
-		Plugins.Outputs = append(Plugins.Outputs, NewDummyOutput(options))
+		registerPlugin(NewDummyOutput, options)
+	}
+
+	engine := EnginePcap
+	if Settings.inputRAWEngine == "raw_socket" {
+		engine = EngineRawSocket
 	}
 
 	for _, options := range Settings.inputRAW {
-		Plugins.Inputs = append(Plugins.Inputs, NewRAWInput(options))
+		registerPlugin(NewRAWInput, engine, options, time.Duration(0))
 	}
 
 	for _, options := range Settings.inputTCP {
-		Plugins.Inputs = append(Plugins.Inputs, NewTCPInput(options))
+		registerPlugin(NewTCPInput, options)
 	}
 
 	for _, options := range Settings.outputTCP {
-		Plugins.Outputs = append(Plugins.Outputs, NewTCPOutput(options))
+		registerPlugin(NewTCPOutput, options)
 	}
 
 	for _, options := range Settings.inputFile {
-		Plugins.Inputs = append(Plugins.Inputs, NewFileInput(options))
+		registerPlugin(NewFileInput, options)
 	}
 
 	for _, options := range Settings.outputFile {
-		Plugins.Outputs = append(Plugins.Outputs, NewFileOutput(options))
+		registerPlugin(NewFileOutput, options)
+	}
+
+	for _, options := range Settings.inputHTTP {
+		registerPlugin(NewHTTPInput, options)
+	}
+
+	// If we explicitly set Host header http output should not rewrite it
+	// Fix: https://github.com/buger/gor/issues/174
+	for _, header := range Settings.modifierConfig.headers {
+		if header.Name == "Host" {
+			Settings.outputHTTPConfig.OriginalHost = true
+			break
+		}
 	}
 
 	for _, options := range Settings.outputHTTP {
-		Plugins.Outputs = append(Plugins.Outputs, NewHTTPOutput(options, Settings.outputHTTPHeaders, Settings.outputHTTPMethods, Settings.outputHTTPElasticSearch))
+		registerPlugin(NewHTTPOutput, options, &Settings.outputHTTPConfig)
 	}
 }

plugins_test.go

@@ -0,0 +1,47 @@
+package main
+
+import (
+	"io"
+	"testing"
+)
+
+func TestPluginsRegistration(t *testing.T) {
+	Plugins.Inputs = []io.Reader{}
+	Plugins.Outputs = []io.Writer{}
+
+	Settings.inputDummy = MultiOption{"[]"}
+	Settings.outputDummy = MultiOption{"[]"}
+	Settings.outputHTTP = MultiOption{"www.example.com|10"}
+	Settings.inputFile = MultiOption{"/dev/null"}
+
+	InitPlugins()
+
+	if len(Plugins.Inputs) != 2 {
+		t.Errorf("Should be 2 inputs %d", len(Plugins.Inputs))
+	}
+
+	if _, ok := Plugins.Inputs[0].(*DummyInput); !ok {
+		t.Errorf("First input should be DummyInput")
+	}
+
+	if _, ok := Plugins.Inputs[1].(*FileInput); !ok {
+		t.Errorf("Second input should be FileInput")
+	}
+
+	if len(Plugins.Outputs) != 2 {
+		t.Errorf("Should be 2 output %d", len(Plugins.Outputs))
+	}
+
+	if _, ok := Plugins.Outputs[0].(*DummyOutput); !ok {
+		t.Errorf("First output should be DummyOutput")
+	}
+
+	if l, ok := Plugins.Outputs[1].(*Limiter); ok {
+		if _, ok := l.plugin.(*HTTPOutput); !ok {
+			t.Errorf("HTTPOutput should be wrapped in limiter")
+		}
+	} else {
+		t.Errorf("Second output should be Limiter")
+	}
+
+}

proto/proto.go

@@ -0,0 +1,235 @@
+/*
+Package proto provides byte-level interaction with HTTP request payload.
+
+Example of HTTP payload for future references, new line symbols escaped:
+
+	POST /upload HTTP/1.1\r\n
+	User-Agent: Gor\r\n
+	Content-Length: 11\r\n
+	\r\n
+	Hello world
+
+	GET /index.html HTTP/1.1\r\n
+	User-Agent: Gor\r\n
+	\r\n
+	\r\n
+*/
+package proto
+
+import (
+	"bytes"
+	"github.com/buger/gor/byteutils"
+)
+
+// In HTTP newline defined by 2 bytes (for both windows and *nix support)
+var CLRF = []byte("\r\n")
+
+// New line acts as separator: end of Headers or Body (in some cases)
+var EmptyLine = []byte("\r\n\r\n")
+
+// Separator for Header line. Header looks like: `HeaderName: value`
+var HeaderDelim = []byte(": ")
+
+// MIMEHeadersEndPos finds end of the Headers section, which should end with empty line.
+func MIMEHeadersEndPos(payload []byte) int {
+	return bytes.Index(payload, EmptyLine)
+}
+
+// MIMEHeadersStartPos finds start of Headers section
+// It just finds position of second line (first contains location and method).
+func MIMEHeadersStartPos(payload []byte) int {
+	return bytes.Index(payload, CLRF) + 2 // Find first line end
+}
+
+// header return value and positions of header/value start/end.
+// If not found, value will be blank, and headerStart will be -1
+// Do not support multi-line headers.
+func header(payload []byte, name []byte) (value []byte, headerStart, valueStart, headerEnd int) {
+	headerStart = bytes.Index(payload, name)
+
+	if headerStart == -1 {
+		return
+	}
+
+	valueStart = headerStart + len(name) + 1 // Skip ":" after header name
+	if payload[valueStart] == ' ' {          // Ignore empty space after ':'
+		valueStart++
+	}
+
+	headerEnd = valueStart + bytes.IndexByte(payload[valueStart:], '\n')
+
+	if payload[headerEnd-1] == '\r' {
+		headerEnd -= 1
+	}
+
+	value = payload[valueStart:headerEnd]
+
+	return
+}
+
+// Header returns header value, if header not found, value will be blank
+func Header(payload, name []byte) []byte {
+	val, _, _, _ := header(payload, name)
+
+	return val
+}
+
+// SetHeader sets header value. If header not found it creates new one.
+// Returns modified request payload
+func SetHeader(payload, name, value []byte) []byte {
+	_, hs, vs, he := header(payload, name)
+
+	if hs != -1 {
+		// If header found we just repace its value
+		return byteutils.Replace(payload, vs, he, value)
+	}
+
+	return AddHeader(payload, name, value)
+}
+
+// AddHeader takes http payload and appends new header to the start of headers section
+// Returns modified request payload
+func AddHeader(payload, name, value []byte) []byte {
+	header := make([]byte, len(name)+2+len(value)+2)
+	copy(header[0:], name)
+	copy(header[len(name):], HeaderDelim)
+	copy(header[len(name)+2:], value)
+	copy(header[len(header)-2:], CLRF)
+
+	mimeStart := MIMEHeadersStartPos(payload)
+
+	return byteutils.Insert(payload, mimeStart, header)
+}
+
+// Body returns request/response body
+func Body(payload []byte) []byte {
+	// 4 -> len(EMPTY_LINE)
+	return payload[MIMEHeadersEndPos(payload)+4:]
+}
+
+// Path takes payload and retuns request path: Split(firstLine, ' ')[1]
+func Path(payload []byte) []byte {
+	start := bytes.IndexByte(payload, ' ') + 1
+	end := bytes.IndexByte(payload[start:], ' ')
+
+	return payload[start : start+end]
+}
+
+// SetPath takes payload, sets new path and returns modified payload
+func SetPath(payload, path []byte) []byte {
+	start := bytes.IndexByte(payload, ' ') + 1
+	end := bytes.IndexByte(payload[start:], ' ')
+
+	return byteutils.Replace(payload, start, start+end, path)
+}
+
+// PathParam returns URL query attribute by given name, if no found: valueStart will be -1
+func PathParam(payload, name []byte) (value []byte, valueStart, valueEnd int) {
+	path := Path(payload)
+
+	if paramStart := bytes.Index(path, append(name, '=')); paramStart != -1 {
+		valueStart := paramStart + len(name) + 1
+		paramEnd := bytes.IndexByte(path[valueStart:], '&')
+
+		// Param can end with '&' (another param), or end of line
+		if paramEnd == -1 { // It is final param
+			paramEnd = len(path)
+		} else {
+			paramEnd += valueStart
+		}
+
+		return path[valueStart:paramEnd], valueStart, paramEnd
+	}
+
+	return []byte(""), -1, -1
+}
+
+// SetPathParam takes payload and updates path Query attribute
+// If query param not found, it will append new
+// Returns modified payload
+func SetPathParam(payload, name, value []byte) []byte {
+	path := Path(payload)
+	_, vs, ve := PathParam(payload, name)
+
+	if vs != -1 { // If param found, replace its value and set new Path
+		newPath := make([]byte, len(path))
+		copy(newPath, path)
+		newPath = byteutils.Replace(newPath, vs, ve, value)
+
+		return SetPath(payload, newPath)
+	}
+
+	// if param not found append to end of url
+	// Adding 2 because of '?' or '&' at start, and '=' in middle
+	newParam := make([]byte, len(name)+len(value)+2)
+
+	if bytes.IndexByte(path, '?') == -1 {
+		newParam[0] = '?'
+	} else {
+		newParam[0] = '&'
+	}
+
+	// Copy "param=value" into buffer, after it looks like "?param=value"
+	copy(newParam[1:], name)
+	newParam[1+len(name)] = '='
+	copy(newParam[2+len(name):], value)
+
+	// Append param to the end of path
+	newPath := make([]byte, len(path)+len(newParam))
+	copy(newPath, path)
+	copy(newPath[len(path):], newParam)
+
+	return SetPath(payload, newPath)
+}
+
+// SetHost updates Host header for HTTP/1.1 or updates host in path for HTTP/1.0 or Proxy requests
+// Returns modified payload
+func SetHost(payload, url, host []byte) []byte {
+	// If this is HTTP 1.0 traffic or proxy traffic it may include host right into path variable, so instead of setting Host header we rewrite Path
+	// Fix for https://github.com/buger/gor/issues/156
+	if path := Path(payload); bytes.HasPrefix(path, []byte("http")) {
+		hostStart := bytes.IndexByte(path, ':') // : position "https?:"
+		hostStart += 3                          // Skip 1 ':' and 2 '\'
+		hostEnd := hostStart + bytes.IndexByte(path[hostStart:], '/')
+
+		newPath := make([]byte, len(path))
+		copy(newPath, path)
+		newPath = byteutils.Replace(newPath, 0, hostEnd, url)
+
+		return SetPath(payload, newPath)
+	}
+
+	return SetHeader(payload, []byte("Host"), host)
+}
+
+// Method returns HTTP method
+func Method(payload []byte) []byte {
+	end := bytes.IndexByte(payload, ' ')
+
+	return payload[:end]
+}
+
+// Status returns response status.
+// It happend to be in same position as request payload path
+func Status(payload []byte) []byte {
+	return Path(payload)
+}
+
+var httpMethods []string = []string{
+	"GET ", "OPTI", "HEAD", "POST", "PUT ", "DELE", "TRAC", "CONN",
+}
+
+func IsHTTPPayload(payload []byte) bool {
+	if len(payload) < 4 {
+		return false
+	}
+
+	method := string(payload[0:4])
+
+	for _, m := range httpMethods {
+		if method == m {
+			return true
+		}
+	}
+	return false
+}

proto/proto_test.go

@@ -0,0 +1,163 @@
+package proto
+
+import (
+	"bytes"
+	"testing"
+)
+
+func TestHeader(t *testing.T) {
+	var payload, val []byte
+	var headerStart int
+
+	// Value with space at start
+	payload = []byte("POST /post HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+
+	if val = Header(payload, []byte("Content-Length")); !bytes.Equal(val, []byte("7")) {
+		t.Error("Should find header value")
+	}
+
+	// Value without space at start
+	payload = []byte("POST /post HTTP/1.1\r\nContent-Length:7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+
+	if val = Header(payload, []byte("Content-Length")); !bytes.Equal(val, []byte("7")) {
+		t.Error("Should find header value without space after :")
+	}
+
+	// Value is empty
+	payload = []byte("GET /p HTTP/1.1\r\nCookie:\r\nHost: www.w3.org\r\n\r\n")
+
+	if val = Header(payload, []byte("Cookie")); len(val) > 0 {
+		t.Error("Should return empty value")
+	}
+
+	// Wrong delimeter
+	payload = []byte("GET /p HTTP/1.1\r\nCookie: 123\nHost: www.w3.org\r\n\r\n")
+
+	if val = Header(payload, []byte("Cookie")); !bytes.Equal(val, []byte("123")) {
+		t.Error("Should handle wrong header delimeter")
+	}
+
+	// Header not found
+	if _, headerStart, _, _ = header(payload, []byte("Not-Found")); headerStart != -1 {
+		t.Error("Should not found header")
+	}
+}
+
+func TestMIMEHeadersEndPos(t *testing.T) {
+	head := []byte("POST /post HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org")
+	payload := []byte("POST /post HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+
+	end := MIMEHeadersEndPos(payload)
+
+	if !bytes.Equal(payload[:end], head) {
+		t.Error("Wrong headers end position:", end)
+	}
+}
+
+func TestMIMEHeadersStartPos(t *testing.T) {
+	headers := []byte("Content-Length: 7\r\nHost: www.w3.org")
+	payload := []byte("POST /post HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+
+	start := MIMEHeadersStartPos(payload)
+	end := MIMEHeadersEndPos(payload)
+
+	if !bytes.Equal(payload[start:end], headers) {
+		t.Error("Wrong headers end position:", start, end)
+	}
+}
+
+func TestSetHeader(t *testing.T) {
+	var payload, payloadAfter []byte
+
+	payload = []byte("POST /post HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+	payloadAfter = []byte("POST /post HTTP/1.1\r\nContent-Length: 14\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+
+	if payload = SetHeader(payload, []byte("Content-Length"), []byte("14")); !bytes.Equal(payload, payloadAfter) {
+		t.Error("Should update header if it exists", string(payload))
+	}
+
+	payload = []byte("POST /post HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+	payloadAfter = []byte("POST /post HTTP/1.1\r\nUser-Agent: Gor\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+
+	if payload = SetHeader(payload, []byte("User-Agent"), []byte("Gor")); !bytes.Equal(payload, payloadAfter) {
+		t.Error("Should add header if not found", string(payload))
+	}
+}
+
+func TestPath(t *testing.T) {
+	var path, payload []byte
+
+	payload = []byte("POST /post HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+
+	if path = Path(payload); !bytes.Equal(path, []byte("/post")) {
+		t.Error("Should find path", string(path))
+	}
+}
+
+func TestSetPath(t *testing.T) {
+	var payload, payloadAfter []byte
+
+	payload = []byte("POST /post HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+	payloadAfter = []byte("POST /new_path HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+
+	if payload = SetPath(payload, []byte("/new_path")); !bytes.Equal(payload, payloadAfter) {
+		t.Error("Should replace path", string(payload))
+	}
+}
+
+func TestPathParam(t *testing.T) {
+	var payload []byte
+
+	payload = []byte("POST /post?param=test&user_id=1 HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+
+	if val, _, _ := PathParam(payload, []byte("param")); !bytes.Equal(val, []byte("test")) {
+		t.Error("Should detect attribute", string(val))
+	}
+
+	if val, _, _ := PathParam(payload, []byte("user_id")); !bytes.Equal(val, []byte("1")) {
+		t.Error("Should detect attribute", string(val))
+	}
+}
+
+func TestSetPathParam(t *testing.T) {
+	var payload, payloadAfter []byte
+
+	payload = []byte("POST /post?param=test&user_id=1 HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+	payloadAfter = []byte("POST /post?param=new&user_id=1 HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+
+	if payload = SetPathParam(payload, []byte("param"), []byte("new")); !bytes.Equal(payload, payloadAfter) {
+		t.Error("Should replace existing value", string(payload))
+	}
+
+	payload = []byte("POST /post?param=test&user_id=1 HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+	payloadAfter = []byte("POST /post?param=test&user_id=2 HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+
+	if payload = SetPathParam(payload, []byte("user_id"), []byte("2")); !bytes.Equal(payload, payloadAfter) {
+		t.Error("Should replace existing value", string(payload))
+	}
+
+	payload = []byte("POST /post HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+	payloadAfter = []byte("POST /post?param=test HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+
+	if payload = SetPathParam(payload, []byte("param"), []byte("test")); !bytes.Equal(payload, payloadAfter) {
+		t.Error("Should set param if url have no params", string(payload))
+	}
+
+	payload = []byte("POST /post?param=test HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+	payloadAfter = []byte("POST /post?param=test&user_id=1 HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+
+	if payload = SetPathParam(payload, []byte("user_id"), []byte("1")); !bytes.Equal(payload, payloadAfter) {
+		t.Error("Should set param at the end if url params", string(payload))
+	}
+}
+
+func TestSetHostHTTP10(t *testing.T) {
+	var payload, payloadAfter []byte
+
+	payload = []byte("POST http://example.com/post HTTP/1.0\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+	payloadAfter = []byte("POST http://new.com/post HTTP/1.0\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
+
+	if payload = SetHost(payload, []byte("http://new.com"), []byte("new.com")); !bytes.Equal(payload, payloadAfter) {
+		t.Error("Should replace host", string(payload))
+	}
+}

protocol.go

@@ -0,0 +1,87 @@
+package main
+
+import (
+	"bytes"
+	"crypto/rand"
+	"encoding/hex"
+	"strconv"
+)
+
+const (
+	RequestPayload          = '1'
+	ResponsePayload         = '2'
+	ReplayedResponsePayload = '3'
+)
+
+func uuid() []byte {
+	b := make([]byte, 20)
+	rand.Read(b)
+
+	uuid := make([]byte, 40)
+	hex.Encode(uuid, b)
+
+	return uuid
+}
+
+var payloadSeparator = "\n🐵🙈🙉\n"
+
+func payloadScanner(data []byte, atEOF bool) (advance int, token []byte, err error) {
+	if atEOF && len(data) == 0 {
+		return 0, nil, nil
+	}
+
+	if i := bytes.Index(data, []byte(payloadSeparator)); i >= 0 {
+		// We have a full newline-terminated line.
+		return i + len([]byte(payloadSeparator)), data[0:i], nil
+	}
+
+	if atEOF {
+		return len(data), data, nil
+	}
+	return 0, nil, nil
+}
+
+// Timing is request start or round-trip time, depending on payloadType
+func payloadHeader(payloadType byte, uuid []byte, timing int64) (header []byte) {
+	sTime := strconv.FormatInt(timing, 10)
+
+	//Example:
+	//  3 f45590522cd1838b4a0d5c5aab80b77929dea3b3 1231\n
+	// `+ 1` indicates space characters or end of line
+	header = make([]byte, 1+1+len(uuid)+1+len(sTime)+1)
+	header[0] = payloadType
+	header[1] = ' '
+	header[2+len(uuid)] = ' '
+	header[len(header)-1] = '\n'
+
+	copy(header[2:], uuid)
+	copy(header[3+len(uuid):], sTime)
+
+	return header
+}
+
+func payloadBody(payload []byte) []byte {
+	headerSize := bytes.IndexByte(payload, '\n')
+	return payload[headerSize+1:]
+}
+
+func payloadMeta(payload []byte) [][]byte {
+	headerSize := bytes.IndexByte(payload, '\n')
+	if headerSize < 0 {
+		headerSize = 0
+	}
+	return bytes.Split(payload[:headerSize], []byte{' '})
+}
+
+func isOriginPayload(payload []byte) bool {
+	switch payload[0] {
+	case RequestPayload, ResponsePayload:
+		return true
+	default:
+		return false
+	}
+}
+
+func isRequestPayload(payload []byte) bool {
+	return payload[0] == RequestPayload
+}

raw_socket_listener/listener.go

@@ -1,105 +1,351 @@
-package raw_socket
+/*
+Package rawSocket provides traffic sniffier using RAW sockets.
+
+Capture traffic from socket using RAW_SOCKET's
+http://en.wikipedia.org/wiki/Raw_socket
+
+RAW_SOCKET allow you listen for traffic on any port (e.g. sniffing) because they operate on IP level.
+
+Ports is TCP feature, same as flow control, reliable transmission and etc.
+
+This package implements own TCP layer: TCP packets is parsed using tcp_packet.go, and flow control is managed by tcp_message.go
+*/
+package rawSocket
 
 import (
+	"bytes"
 	"encoding/binary"
+	"fmt"
+	"github.com/google/gopacket"
+	_ "github.com/google/gopacket/layers"
+	"github.com/google/gopacket/pcap"
+	"io"
 	"log"
 	"net"
+	"runtime/debug"
 	"strconv"
+	"strings"
+	"sync"
+	"time"
 )
 
-// Capture traffic from socket using RAW_SOCKET's
-// http://en.wikipedia.org/wiki/Raw_socket
-//
-// RAW_SOCKET allow you listen for traffic on any port (e.g. sniffing) because they operate on IP level.
-// Ports is TCP feature, same as flow control, reliable transmission and etc.
-// Since we can't use default TCP libraries RAWTCPLitener implements own TCP layer
-// TCP packets is parsed using tcp_packet.go, and flow control is managed by tcp_message.go
+var _ = fmt.Println
+
+// Listener handle traffic capture
 type Listener struct {
-	messages map[uint32]*TCPMessage // buffer of TCPMessages waiting to be send
+	mu sync.Mutex
+	// buffer of TCPMessages waiting to be send
+	// ID -> TCPMessage
+	messages map[string]*TCPMessage
 
-	c_packets  chan *TCPPacket
-	c_messages chan *TCPMessage // Messages ready to be send to client
+	// Expect: 100-continue request is send in 2 tcp messages
+	// We store ACK aliases to merge this packets together
+	ackAliases map[uint32]uint32
+	// To get ACK of second message we need to compute its Seq and wait for them message
+	seqWithData map[uint32]uint32
 
-	c_del_message chan *TCPMessage // Used for notifications about completed or expired messages
+	// Ack -> Req
+	respAliases map[uint32]*request
+
+	// Ack -> ID
+	respWithoutReq map[uint32]string
+
+	// Messages ready to be send to client
+	packetsChan chan *TCPPacket
+
+	// Messages ready to be send to client
+	messagesChan chan *TCPMessage
 
 	addr string // IP to listen
-	port int    // Port to listen
+	port uint16 // Port to listen
+
+	messageExpire time.Duration
+
+	conn net.PacketConn
+	quit chan bool
 }
 
-// RAWTCPListen creates a listener to capture traffic from RAW_SOCKET
-func NewListener(addr string, port string) (rawListener *Listener) {
-	rawListener = &Listener{}
+type request struct {
+	id    string
+	start time.Time
+	ack   uint32
+}
 
-	rawListener.c_packets = make(chan *TCPPacket, 100)
-	rawListener.c_messages = make(chan *TCPMessage, 100)
-	rawListener.c_del_message = make(chan *TCPMessage, 100)
-	rawListener.messages = make(map[uint32]*TCPMessage)
+// Available engines for intercepting traffic
+const (
+	EngineRawSocket = 1 << iota
+	EnginePcap
+)
 
-	rawListener.addr = addr
-	rawListener.port, _ = strconv.Atoi(port)
+// NewListener creates and initializes new Listener object
+func NewListener(addr string, port string, engine int, expire time.Duration) (l *Listener) {
+	l = &Listener{}
 
-	go rawListener.listen()
-	go rawListener.readRAWSocket()
+	l.packetsChan = make(chan *TCPPacket, 10000)
+	l.messagesChan = make(chan *TCPMessage, 10000)
+	l.quit = make(chan bool)
+
+	l.messages = make(map[string]*TCPMessage)
+	l.ackAliases = make(map[uint32]uint32)
+	l.seqWithData = make(map[uint32]uint32)
+	l.respAliases = make(map[uint32]*request)
+	l.respWithoutReq = make(map[uint32]string)
+
+	l.addr = addr
+	_port, _ := strconv.Atoi(port)
+	l.port = uint16(_port)
+
+	if expire.Nanoseconds() == 0 {
+		expire = 2000 * time.Millisecond
+	}
+
+	l.messageExpire = expire
+
+	go l.listen()
+	go l.processPackets()
+
+	// Special case for testing
+	if l.port != 0 {
+		switch engine {
+		case EngineRawSocket:
+			go l.readRAWSocket()
+		case EnginePcap:
+			go l.readPcap()
+		default:
+			log.Fatal("Unknown traffic interception engine:", engine)
+		}
+	}
 
 	return
 }
 
+func (t *Listener) processPackets() {
+	for {
+		// We need to use channels to process each packet to avoid data races
+		packet := <-t.packetsChan
+		// log.Println(packet)
+		t.mu.Lock()
+		t.processTCPPacket(packet)
+		t.mu.Unlock()
+	}
+}
+
 func (t *Listener) listen() {
+	gcTicker := time.Tick(t.messageExpire / 2)
+
 	for {
 		select {
-		// If message ready for deletion it means that its also complete or expired by timeout
-		case message := <-t.c_del_message:
-			t.c_messages <- message
-			delete(t.messages, message.Ack)
+		case <-t.quit:
+			if t.conn != nil {
+				t.conn.Close()
+			}
+			return
+		case <-gcTicker:
+			now := time.Now()
+			// log.Println("GC")
 
-		// We need to use channels to process each packet to avoid data races
-		case packet := <-t.c_packets:
-			t.processTCPPacket(packet)
+			t.mu.Lock()
+			// Dispatch requests before responses
+			for _, message := range t.messages {
+				if now.Sub(message.End) >= t.messageExpire {
+					t.dispatchMessage(message)
+				}
+			}
+
+			t.mu.Unlock()
+		}
+	}
+}
+
+func (t *Listener) dispatchMessage(message *TCPMessage) {
+	// If already dispatched
+	if _, ok := t.messages[message.ID]; !ok {
+		return
+	}
+
+	delete(t.ackAliases, message.Ack)
+	delete(t.messages, message.ID)
+
+	// log.Println("Dispatching, message", message.Seq, message.Ack, string(message.Bytes()))
+
+	if message.IsIncoming {
+		// If there were response before request
+		// log.Println("Looking for Response: ", t.respWithoutReq, message.ResponseAck)
+		if respID, ok := t.respWithoutReq[message.ResponseAck]; ok {
+			if resp, rok := t.messages[respID]; rok {
+				if resp.RequestAck == 0 {
+					// log.Println("FOUND RESPONSE")
+					resp.RequestAck = message.Ack
+					resp.RequestStart = message.Start
+
+					if resp.IsFinished() {
+						defer t.dispatchMessage(resp)
+					}
+				}
+			}
+		}
+	} else {
+		if message.RequestAck == 0 {
+			if responseRequest, ok := t.respAliases[message.Ack]; ok {
+				message.RequestStart = responseRequest.start
+				message.RequestAck = responseRequest.ack
+			}
+		}
+
+		delete(t.respAliases, message.Ack)
+		delete(t.respWithoutReq, message.Ack)
+
+		// Do not track responses which have no associated requests
+		if message.RequestAck == 0 {
+			// log.Println("Can't dispatch resp", message.Seq, message.Ack, string(message.Bytes()))
+			return
+		}
+	}
+
+	t.messagesChan <- message
+}
+
+// DeviceNotFoundError raised if user specified wrong ip
+type DeviceNotFoundError struct {
+	addr string
+}
+
+func (e *DeviceNotFoundError) Error() string {
+	devices, _ := pcap.FindAllDevs()
+
+	var msg string
+	msg += "Devices with addr: " + e.addr + " not found. Available devices: \n"
+	for _, device := range devices {
+		msg += "Name: " + device.Name + "\n"
+		msg += "Description: " + device.Description + "\n"
+		msg += "Devices addresses: " + device.Description + "\n"
+		for _, address := range device.Addresses {
+			msg += "- IP address: " + address.IP.String() + "\n"
+			msg += "- Subnet mask: " + address.Netmask.String() + "\n"
+		}
+	}
+
+	return msg
+}
+
+func findPcapDevice(addr string) (*pcap.Interface, error) {
+	devices, err := pcap.FindAllDevs()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	for _, device := range devices {
+		if device.Name == "any" && addr == "" || addr == "0.0.0.0" {
+			return &device, nil
+		}
+
+		for _, address := range device.Addresses {
+			if address.IP.String() == addr {
+				return &device, nil
+			}
+		}
+	}
+
+	return nil, &DeviceNotFoundError{addr}
+}
+
+func (t *Listener) readPcap() {
+	device, err := findPcapDevice(t.addr)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	handle, err := pcap.OpenLive(device.Name, 65536, true, t.messageExpire)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer handle.Close()
+
+	if err := handle.SetBPFFilter("tcp and port " + strconv.Itoa(int(t.port))); err != nil {
+		log.Fatal(err)
+	}
+
+	source := gopacket.NewPacketSource(handle, handle.LinkType())
+	source.Lazy = true
+	source.NoCopy = true
+
+	// log.Println(handle.Stats())
+
+	for {
+		packet, err := source.NextPacket()
+
+		if err == io.EOF {
+			break
+		} else if err != nil {
+			continue
+		}
+
+		// Skip ethernet layer, 14 bytes
+		data := packet.Data()[14:]
+		ihl := uint8(data[0]) & 0x0F
+		srcIP := data[12:16]
+		data = data[ihl*4:]
+
+		dataOffset := (data[12] & 0xF0) >> 4
+
+		// We need only packets with data inside
+		// Check that the buffer is larger than the size of the TCP header
+		if len(data) > int(dataOffset*4) {
+			newBuf := make([]byte, len(data))
+			copy(newBuf, data)
+
+			go func(newBuf []byte) {
+				t.packetsChan <- ParseTCPPacket(net.IP(srcIP).String(), newBuf)
+			}(newBuf)
 		}
 	}
 }
 
 func (t *Listener) readRAWSocket() {
 	conn, e := net.ListenPacket("ip4:tcp", t.addr)
-	defer conn.Close()
+	t.conn = conn
 
 	if e != nil {
 		log.Fatal(e)
 	}
 
-	buf := make([]byte, 4096*2)
+	defer t.conn.Close()
+
+	buf := make([]byte, 64*1024) // 64kb
 
 	for {
 		// Note: ReadFrom receive messages without IP header
-		n, _, err := conn.ReadFrom(buf)
+		n, addr, err := t.conn.ReadFrom(buf)
 
 		if err != nil {
-			log.Println("Error:", err)
-			continue
+			if strings.HasSuffix(err.Error(), "closed network connection") {
+				return
+			} else {
+				continue
+			}
 		}
 
 		if n > 0 {
-			t.parsePacket(buf[:n])
+			if t.isValidPacket(buf[:n]) {
+				newBuf := make([]byte, n)
+				copy(newBuf, buf[:n])
+
+				go func(newBuf []byte) {
+					t.packetsChan <- ParseTCPPacket(addr.String(), newBuf)
+				}(newBuf)
+			}
 		}
 	}
 }
 
-func (t *Listener) parsePacket(buf []byte) {
-	if t.isIncomingDataPacket(buf) {
-		new_buf := make([]byte, len(buf))
-		copy(new_buf, buf)
-
-		t.c_packets <- ParseTCPPacket(new_buf)
-	}
-}
-
-func (t *Listener) isIncomingDataPacket(buf []byte) bool {
+func (t *Listener) isValidPacket(buf []byte) bool {
 	// To avoid full packet parsing every time, we manually parsing values needed for packet filtering
 	// http://en.wikipedia.org/wiki/Transmission_Control_Protocol
-	dest_port := binary.BigEndian.Uint16(buf[2:4])
+	destPort := binary.BigEndian.Uint16(buf[2:4])
+	srcPort := binary.BigEndian.Uint16(buf[0:2])
 
 	// Because RAW_SOCKET can't be bound to port, we have to control it by ourself
-	if int(dest_port) == t.port {
+	if destPort == t.port || srcPort == t.port {
 		// Get the 'data offset' (size of the TCP header in 32-bit words)
 		dataOffset := (buf[12] & 0xF0) >> 4
 
@@ -114,27 +360,148 @@ func (t *Listener) isIncomingDataPacket(buf []byte) bool {
 	return false
 }
 
+var bExpect100ContinueCheck = []byte("Expect: 100-continue")
+var bPOST = []byte("POST")
+
 // Trying to add packet to existing message or creating new message
 //
 // For TCP message unique id is Acknowledgment number (see tcp_packet.go)
 func (t *Listener) processTCPPacket(packet *TCPPacket) {
-	defer func() { recover() }()
-	
+	// Don't exit on panic
+	defer func() {
+		if r := recover(); r != nil {
+			log.Println("PANIC: pkg:", r, packet, string(debug.Stack()))
+		}
+	}()
+
+	// log.Println("Processing packet:", packet.Ack, packet.Seq, string(packet.Data))
+
 	var message *TCPMessage
 
-	message, ok := t.messages[packet.Ack]
+	isIncoming := packet.DestPort == t.port
+
+	// Seek for 100-expect chunks
+	if parentAck, ok := t.seqWithData[packet.Seq]; ok {
+		// log.Println("Found data package with Ack:", packet.Ack)
+		// In case if non-first data chunks comes first
+		for _id, m := range t.messages {
+			// log.Println("Message ack:", m.Ack, m.packets[0].Addr, packet.Addr)
+			if m.Ack == packet.Ack && m.packets[0].Addr == packet.Addr {
+				delete(t.messages, _id)
+
+				for _, pkt := range m.packets {
+					pkt.Ack = parentAck
+					// Re-queue this packets
+					t.processTCPPacket(pkt)
+				}
+			}
+		}
+
+		delete(t.seqWithData, packet.Seq)
+		t.ackAliases[packet.Ack] = parentAck
+		packet.Ack = parentAck
+	}
+
+	if alias, ok := t.ackAliases[packet.Ack]; ok {
+		packet.Ack = alias
+	}
+
+	var responseRequest *request
+
+	if !isIncoming {
+		responseRequest, _ = t.respAliases[packet.Ack]
+	}
+
+	mID := packet.Addr + strconv.Itoa(int(packet.DestPort)) + strconv.Itoa(int(packet.Ack))
+
+	message, ok := t.messages[mID]
 
 	if !ok {
-		// We sending c_del_message channel, so message object can communicate with Listener and notify it if message completed
-		message = NewTCPMessage(packet.Ack, t.c_del_message)
-		t.messages[packet.Ack] = message
+		message = NewTCPMessage(mID, packet.Seq, packet.Ack, isIncoming)
+		t.messages[mID] = message
+
+		if !isIncoming {
+			if responseRequest != nil {
+				message.RequestStart = responseRequest.start
+				message.RequestAck = responseRequest.ack
+				message.RequestID = responseRequest.id
+			} else {
+				t.respWithoutReq[packet.Ack] = mID
+			}
+		}
+	}
+
+	// Handling Expect: 100-continue requests
+	if len(packet.Data) > 4 && bytes.Equal(packet.Data[0:4], bPOST) {
+		// reading last 20 bytes (not counting CRLF): last header value (if no body presented)
+		if bytes.Equal(packet.Data[len(packet.Data)-24:len(packet.Data)-4], bExpect100ContinueCheck) {
+			seq := packet.Seq + uint32(len(packet.Data))
+			t.seqWithData[seq] = packet.Ack
+
+			// In case if sequence packet came first
+			// log.Println("Looking for sequences:", seq, t.messages)
+			for _id, m := range t.messages {
+				// log.Println("SeqSEQ", m.Seq, len(m.packets))
+				if m.Seq == seq {
+					t.ackAliases[m.Ack] = packet.Ack
+
+					for _, pkt := range m.packets {
+						message.AddPacket(pkt)
+					}
+
+					delete(t.messages, _id)
+				}
+			}
+
+			// Removing `Expect: 100-continue` header
+			packet.Data = append(packet.Data[:len(packet.Data)-24], packet.Data[len(packet.Data)-2:]...)
+
+			// log.Println(string(packet.Data))
+		}
 	}
 
 	// Adding packet to message
-	message.c_packets <- packet
+	message.AddPacket(packet)
+
+	if isIncoming {
+		// If message have multiple packets, delete previous alias
+		if len(message.packets) > 1 {
+			delete(t.respAliases, message.ResponseAck)
+		}
+
+		message.UpdateResponseAck()
+		t.respAliases[message.ResponseAck] = &request{message.ID, message.Start, message.Ack}
+	}
+
+	// If message contains only single packet immediately dispatch it
+	if message.IsFinished() {
+		if isIncoming {
+			if resp, ok := t.messages[message.ResponseID()]; ok {
+				t.dispatchMessage(message)
+				if resp.IsFinished() {
+					t.dispatchMessage(resp)
+				}
+			}
+		} else {
+			if req, ok := t.messages[message.RequestID]; ok {
+				if req.IsFinished() {
+					t.dispatchMessage(req)
+					t.dispatchMessage(message)
+				}
+			}
+		}
+	}
 }
 
 // Receive TCP messages from the listener channel
 func (t *Listener) Receive() *TCPMessage {
-	return <-t.c_messages
+	return <-t.messagesChan
+}
+
+func (t *Listener) Close() {
+	close(t.quit)
+	if t.conn != nil {
+		t.conn.Close()
+	}
+	return
 }

raw_socket_listener/listener_test.go

@@ -0,0 +1,291 @@
+package rawSocket
+
+import (
+	"bytes"
+	_ "log"
+	"testing"
+	"time"
+)
+
+func TestRawListenerInput(t *testing.T) {
+	var req, resp *TCPMessage
+
+	listener := NewListener("", "0", EnginePcap, 10*time.Millisecond)
+	defer listener.Close()
+
+	reqPacket := buildPacket(true, 1, 1, []byte("GET / HTTP/1.1"))
+
+	respAck := reqPacket.Seq + uint32(len(reqPacket.Data))
+	respPacket := buildPacket(false, respAck, reqPacket.Seq+1, []byte("HTTP/1.1 200 OK"))
+
+	listener.processTCPPacket(reqPacket)
+	listener.processTCPPacket(respPacket)
+
+	select {
+	case req = <-listener.messagesChan:
+	case <-time.After(time.Millisecond):
+		t.Error("Should return request immediately")
+		return
+	}
+
+	if !req.IsIncoming {
+		t.Error("Should be request")
+	}
+
+	select {
+	case resp = <-listener.messagesChan:
+	case <-time.After(20 * time.Millisecond):
+		t.Error("Should return response immediately")
+		return
+	}
+
+	if resp.IsIncoming {
+		t.Error("Should be response")
+	}
+}
+
+func TestRawListenerResponse(t *testing.T) {
+	var req, resp *TCPMessage
+
+	listener := NewListener("", "0", EnginePcap, 10*time.Millisecond)
+	defer listener.Close()
+
+	reqPacket := buildPacket(true, 1, 1, []byte("GET / HTTP/1.1"))
+	respPacket := buildPacket(false, 1+uint32(len(reqPacket.Data)), 2, []byte("HTTP/1.1 200 OK"))
+
+	// If response packet comes before request
+	listener.processTCPPacket(respPacket)
+	listener.processTCPPacket(reqPacket)
+
+	select {
+	case req = <-listener.messagesChan:
+	case <-time.After(time.Millisecond):
+		t.Error("Should return respose immediately")
+		return
+	}
+
+	if !req.IsIncoming {
+		t.Error("Should be request")
+	}
+
+	select {
+	case resp = <-listener.messagesChan:
+	case <-time.After(time.Millisecond):
+		t.Error("Should return response immediately")
+		return
+	}
+
+	if resp.IsIncoming {
+		t.Error("Should be response")
+	}
+
+	if !bytes.Equal(resp.UUID(), req.UUID()) {
+		t.Error("Resp and Req UUID should be equal")
+	}
+}
+
+func TestRawListener100Continue(t *testing.T) {
+	var req, resp *TCPMessage
+
+	listener := NewListener("", "0", EnginePcap, 10*time.Millisecond)
+	defer listener.Close()
+
+	reqPacket1 := buildPacket(true, 1, 1, []byte("POST / HTTP/1.1\r\nContent-Length: 2\r\nExpect: 100-continue\r\n\r\n"))
+	// Packet with data have different Seq
+	reqPacket2 := buildPacket(true, 2, reqPacket1.Seq+uint32(len(reqPacket1.Data)), []byte("a"))
+	reqPacket3 := buildPacket(true, 2, reqPacket2.Seq+1, []byte("b"))
+
+	respPacket1 := buildPacket(false, 10, 3, []byte("HTTP/1.1 100 Continue\r\n"))
+
+	// panic(int(uint32(len(reqPacket1.Data)) + uint32(len(reqPacket2.Data)) + uint32(len(reqPacket3.Data))))
+	respPacket2 := buildPacket(false, reqPacket3.Seq+1 /* len of data */, 2, []byte("HTTP/1.1 200 OK\r\n"))
+
+	listener.processTCPPacket(reqPacket1)
+	listener.processTCPPacket(reqPacket2)
+	listener.processTCPPacket(reqPacket3)
+
+	listener.processTCPPacket(respPacket1)
+	listener.processTCPPacket(respPacket2)
+
+	select {
+	case req = <-listener.messagesChan:
+		break
+	case <-time.After(11 * time.Millisecond):
+		t.Error("Should return request after expire time")
+		return
+	}
+
+	if !bytes.Equal(req.Bytes(), []byte("POST / HTTP/1.1\r\nContent-Length: 2\r\n\r\nab")) {
+		t.Error("Should receive full message", string(req.Bytes()))
+	}
+
+	if !req.IsIncoming {
+		t.Error("Should be request")
+	}
+
+	select {
+	case resp = <-listener.messagesChan:
+		break
+	case <-time.After(21 * time.Millisecond):
+		t.Error("Should return response after expire time")
+		return
+	}
+
+	if resp.IsIncoming {
+		t.Error("Should be response")
+	}
+
+	if !bytes.Equal(resp.UUID(), req.UUID()) {
+		t.Error("Resp and Req UUID should be equal")
+	}
+}
+
+// Response comes before Request
+func TestRawListener100ContinueWrongOrder(t *testing.T) {
+	var req, resp *TCPMessage
+
+	listener := NewListener("", "0", EnginePcap, 10*time.Millisecond)
+	defer listener.Close()
+
+	reqPacket1 := buildPacket(true, 1, 1, []byte("POST / HTTP/1.1\r\nContent-Length: 2\r\nExpect: 100-continue\r\n\r\n"))
+	// Packet with data have different Seq
+	reqPacket2 := buildPacket(true, 2, reqPacket1.Seq+uint32(len(reqPacket1.Data)), []byte("a"))
+	reqPacket3 := buildPacket(true, 2, reqPacket2.Seq+1, []byte("b"))
+
+	respPacket1 := buildPacket(false, 10, 3, []byte("HTTP/1.1 100 Continue\r\n"))
+
+	// panic(int(uint32(len(reqPacket1.Data)) + uint32(len(reqPacket2.Data)) + uint32(len(reqPacket3.Data))))
+	respPacket2 := buildPacket(false, reqPacket3.Seq+1 /* len of data */, 2, []byte("HTTP/1.1 200 OK\r\n"))
+
+	listener.processTCPPacket(respPacket1)
+	listener.processTCPPacket(respPacket2)
+
+	listener.processTCPPacket(reqPacket1)
+	listener.processTCPPacket(reqPacket2)
+	listener.processTCPPacket(reqPacket3)
+
+	select {
+	case req = <-listener.messagesChan:
+		break
+	case <-time.After(11 * time.Millisecond):
+		t.Error("Should return response after expire time")
+		return
+	}
+
+	if !bytes.Equal(req.Bytes(), []byte("POST / HTTP/1.1\r\nContent-Length: 2\r\n\r\nab")) {
+		t.Error("Should receive full message", string(req.Bytes()))
+	}
+
+	if !req.IsIncoming {
+		t.Error("Should be request")
+	}
+
+	select {
+	case resp = <-listener.messagesChan:
+		break
+	case <-time.After(21 * time.Millisecond):
+		t.Error("Should return response after expire time")
+		return
+	}
+
+	if resp.IsIncoming {
+		t.Error("Should be response")
+	}
+
+	if !bytes.Equal(resp.UUID(), req.UUID()) {
+		t.Error("Resp and Req UUID should be equal")
+	}
+}
+
+func testChunkedSequence(t *testing.T, listener *Listener, packets ...*TCPPacket) {
+	var r, req, resp *TCPMessage
+
+	for _, p := range packets {
+		listener.processTCPPacket(p)
+	}
+
+	select {
+	case r = <-listener.messagesChan:
+		if r.IsIncoming {
+			req = r
+		} else {
+			resp = r
+		}
+		break
+	case <-time.After(25 * time.Millisecond):
+		t.Error("Should return request after expire time")
+		return
+	}
+	select {
+	case r = <-listener.messagesChan:
+		if r.IsIncoming {
+			req = r
+		} else {
+			resp = r
+		}
+		break
+	case <-time.After(25 * time.Millisecond):
+		t.Error("Should return request after expire time")
+		return
+	}
+
+	if !bytes.Equal(req.Bytes(), []byte("POST / HTTP/1.1\r\nTransfer-Encoding: chunked\r\n\r\n1\r\na\r\n1\r\nb\r\n0\r\n\r\n")) {
+		t.Error("Should receive full message", string(req.Bytes()))
+	}
+
+	if !req.IsIncoming {
+		t.Error("Should be request")
+	}
+
+	if resp.IsIncoming {
+		t.Error("Should be response")
+	}
+
+	if !bytes.Equal(resp.UUID(), req.UUID()) {
+		t.Error("Resp and Req UUID should be equal", string(resp.UUID()), string(req.UUID()))
+	}
+
+	time.Sleep(15 * time.Millisecond)
+
+	if len(listener.messages) != 0 {
+		t.Error("Messages non empty:", listener.messages)
+	}
+}
+
+func permutation(n int, list []*TCPPacket) []*TCPPacket {
+	if len(list) == 1 {
+		return list
+	}
+
+	k := n % len(list)
+
+	first := []*TCPPacket{list[k]}
+	next := make([]*TCPPacket, len(list)-1)
+
+	copy(next, append(list[:k], list[k+1:]...))
+
+	return append(first, permutation(n/len(list), next)...)
+}
+
+// Response comes before Request
+func TestRawListenerChunkedWrongOrder(t *testing.T) {
+	listener := NewListener("", "0", EnginePcap, 10*time.Millisecond)
+	defer listener.Close()
+
+	reqPacket1 := buildPacket(true, 1, 1, []byte("POST / HTTP/1.1\r\nTransfer-Encoding: chunked\r\nExpect: 100-continue\r\n\r\n"))
+	// Packet with data have different Seq
+	reqPacket2 := buildPacket(true, 2, reqPacket1.Seq+uint32(len(reqPacket1.Data)), []byte("1\r\na\r\n"))
+	reqPacket3 := buildPacket(true, 2, reqPacket2.Seq+uint32(len(reqPacket2.Data)), []byte("1\r\nb\r\n"))
+	reqPacket4 := buildPacket(true, 2, reqPacket3.Seq+uint32(len(reqPacket3.Data)), []byte("0\r\n\r\n"))
+
+	respPacket1 := buildPacket(false, 10, 3, []byte("HTTP/1.1 100 Continue\r\n"))
+
+	// panic(int(uint32(len(reqPacket1.Data)) + uint32(len(reqPacket2.Data)) + uint32(len(reqPacket3.Data))))
+	respPacket2 := buildPacket(false, reqPacket4.Seq+5 /* len of data */, 2, []byte("HTTP/1.1 200 OK\r\n"))
+
+	// Should re-construct message from all possible combinations
+	for i := 0; i < 6*5*4*3*2*1; i++ {
+		packets := permutation(i, []*TCPPacket{reqPacket1, reqPacket2, reqPacket3, reqPacket4, respPacket1, respPacket2})
+		testChunkedSequence(t, listener, packets...)
+	}
+}

raw_socket_listener/tcp_message.go

@@ -1,79 +1,78 @@
-package raw_socket
+package rawSocket
 
 import (
+	"bytes"
+	"crypto/sha1"
+	"encoding/hex"
+	"github.com/buger/gor/proto"
 	"log"
-	"sort"
+	"strconv"
 	"time"
 )
 
-const MSG_EXPIRE = 200 * time.Millisecond
-
 // TCPMessage ensure that all TCP packets for given request is received, and processed in right sequence
 // Its needed because all TCP message can be fragmented or re-transmitted
 //
 // Each TCP Packet have 2 ids: acknowledgment - message_id, and sequence - packet_id
 // Message can be compiled from unique packets with same message_id which sorted by sequence
-// Message is received if we didn't receive any packets for 200ms
+// Message is received if we didn't receive any packets for 2000ms
 type TCPMessage struct {
-	Ack     uint32 // Message ID
+	ID           string // Message ID
+	Seq          uint32
+	Ack          uint32
+	ResponseAck  uint32
+	RequestStart time.Time
+	RequestAck   uint32
+	RequestID    string
+	Start        time.Time
+	End          time.Time
+	IsIncoming   bool
+
 	packets []*TCPPacket
 
-	timer *time.Timer // Used for expire check
-
-	c_packets chan *TCPPacket
-
-	c_del_message chan *TCPMessage
+	delChan chan *TCPMessage
 }
 
 // NewTCPMessage pointer created from a Acknowledgment number and a channel of messages readuy to be deleted
-func NewTCPMessage(Ack uint32, c_del chan *TCPMessage) (msg *TCPMessage) {
-	msg = &TCPMessage{Ack: Ack}
-
-	msg.c_packets = make(chan *TCPPacket)
-	msg.c_del_message = c_del // used for notifying that message completed or expired
-
-	// Every time we receive packet we reset this timer
-	msg.timer = time.AfterFunc(MSG_EXPIRE, msg.Timeout)
-
-	go msg.listen()
+func NewTCPMessage(ID string, Seq, Ack uint32, IsIncoming bool) (msg *TCPMessage) {
+	msg = &TCPMessage{ID: ID, Seq: Seq, Ack: Ack, IsIncoming: IsIncoming}
+	msg.Start = time.Now()
 
 	return
 }
 
-func (t *TCPMessage) listen() {
-	for {
-		select {
-		case packet, more := <-t.c_packets:
-			if more {
-				t.AddPacket(packet)
-			} else {
-				// Stop loop if channel closed
-				return
-			}
-		}
-	}
-}
-
-// Timeout notifies message to stop listening, close channel and message ready to be sent
-func (t *TCPMessage) Timeout() {
-	close(t.c_packets)   // Notify to stop listen loop and close channel
-	t.c_del_message <- t // Notify RAWListener that message is ready to be send to replay server
-}
-
-// Bytes sorts packets in right orders and return message content
+// Bytes return message content
 func (t *TCPMessage) Bytes() (output []byte) {
-	mk := make([]int, len(t.packets))
-
-	i := 0
-	for k, _ := range t.packets {
-		mk[i] = k
-		i++
+	for _, p := range t.packets {
+		output = append(output, p.Data...)
 	}
 
-	sort.Ints(mk)
+	return output
+}
 
-	for _, k := range mk {
-		output = append(output, t.packets[k].Data...)
+// Size returns total body size
+func (t *TCPMessage) BodySize() (size int) {
+	if len(t.packets) == 0 {
+		return 0
+	}
+
+	size += len(proto.Body(t.packets[0].Data))
+
+	for _, p := range t.packets[1:] {
+		size += len(p.Data)
+	}
+
+	return
+}
+
+// Size returns total size of message
+func (t *TCPMessage) Size() (size int) {
+	if len(t.packets) == 0 {
+		return 0
+	}
+
+	for _, p := range t.packets {
+		size += len(p.Data)
 	}
 
 	return
@@ -94,9 +93,110 @@ func (t *TCPMessage) AddPacket(packet *TCPPacket) {
 	if packetFound {
 		log.Println("Received packet with same sequence")
 	} else {
-		t.packets = append(t.packets, packet)
+		// Packets not always captured in same Seq order, and sometimes we need to prepend
+		if len(t.packets) == 0 || packet.Seq > t.packets[len(t.packets)-1].Seq {
+			t.packets = append(t.packets, packet)
+		} else if packet.Seq < t.packets[0].Seq {
+			t.packets = append([]*TCPPacket{packet}, t.packets...)
+			t.Seq = packet.Seq // Message Seq should indicated starting seq
+		} else { // insert somewhere in the middle...
+			for i, p := range t.packets {
+				if packet.Seq < p.Seq {
+					t.packets = append(t.packets[:i], append([]*TCPPacket{packet}, t.packets[i:]...)...)
+					break
+				}
+			}
+		}
+
+		if t.IsIncoming {
+			t.End = time.Now()
+		} else {
+			t.End = time.Now().Add(time.Millisecond)
+		}
+	}
+}
+
+// isMultipart returns true if message contains from multiple tcp packets
+func (t *TCPMessage) IsFinished() bool {
+	payload := t.packets[0].Data
+
+	if len(payload) < 4 {
+		return true
 	}
 
-	// Reset message timeout timer
-	t.timer.Reset(MSG_EXPIRE)
+	m := payload[:4]
+
+	if t.IsIncoming {
+		// If one GET, OPTIONS, or HEAD request
+		if bytes.Equal(m, []byte("GET ")) || bytes.Equal(m, []byte("OPTI")) || bytes.Equal(m, []byte("HEAD")) {
+			return true
+		} else {
+			// Sometimes header comes after the body :(
+			if bytes.Equal(m, []byte("POST")) || bytes.Equal(m, []byte("PUT ")) || bytes.Equal(m, []byte("PATC")) {
+				if length := proto.Header(payload, []byte("Content-Length")); len(length) > 0 {
+					l, _ := strconv.Atoi(string(length))
+
+					// If content-length equal current body length
+					if l > 0 && l == t.BodySize() {
+						return true
+					}
+				}
+			}
+		}
+	} else {
+		// Request not found
+		// Can be because response came first or request request was just missing
+		if t.RequestAck == 0 {
+			return false
+		}
+
+		if length := proto.Header(payload, []byte("Content-Length")); len(length) > 0 {
+			if length[0] == '0' {
+				return true
+			}
+
+			l, _ := strconv.Atoi(string(length))
+
+			// If content-length equal current body length
+			if l > 0 && l == t.BodySize() {
+				return true
+			}
+		} else {
+			if enc := proto.Header(payload, []byte("Transfer-Encoding")); len(enc) == 0 {
+				return true
+			}
+		}
+	}
+
+	return false
+}
+
+func (t *TCPMessage) UUID() []byte {
+	var key []byte
+
+	if t.IsIncoming {
+		key = strconv.AppendInt(key, t.Start.UnixNano(), 10)
+		key = strconv.AppendUint(key, uint64(t.Ack), 10)
+	} else {
+		key = strconv.AppendInt(key, t.RequestStart.UnixNano(), 10)
+		key = strconv.AppendUint(key, uint64(t.RequestAck), 10)
+	}
+
+	uuid := make([]byte, 40)
+	sha := sha1.Sum(key)
+	hex.Encode(uuid, sha[:20])
+
+	return uuid
+}
+
+// UpdateResponseAck should be called after packet is added
+func (t *TCPMessage) UpdateResponseAck() uint32 {
+	lastPacket := t.packets[len(t.packets)-1]
+	t.ResponseAck = lastPacket.Seq + uint32(len(lastPacket.Data))
+	return t.ResponseAck
+}
+
+// ResponseID generate message ID for request response
+func (t *TCPMessage) ResponseID() string {
+	return t.packets[0].Addr + strconv.Itoa(int(t.packets[0].SrcPort)) + strconv.Itoa(int(t.ResponseAck))
 }

raw_socket_listener/tcp_message_test.go

@@ -0,0 +1,152 @@
+package rawSocket
+
+import (
+	"bytes"
+	_ "log"
+	"strconv"
+	"testing"
+)
+
+func buildPacket(isIncoming bool, Ack, Seq uint32, Data []byte) (packet *TCPPacket) {
+	packet = &TCPPacket{
+		Addr: "",
+		Ack:  Ack,
+		Seq:  Seq,
+		Data: Data,
+	}
+
+	// For tests `listening` port is 0
+	if isIncoming {
+		packet.SrcPort = 1
+	} else {
+		packet.DestPort = 1
+	}
+
+	return packet
+}
+
+func buildMessage(p *TCPPacket) *TCPMessage {
+	id := p.Addr + strconv.Itoa(int(p.DestPort)) + strconv.Itoa(int(p.Ack))
+
+	isIncoming := false
+	if p.SrcPort == 1 {
+		isIncoming = true
+	}
+
+	m := NewTCPMessage(id, p.Seq, p.Ack, isIncoming)
+	m.AddPacket(p)
+
+	return m
+}
+
+func TestTCPMessagePacketsOrder(t *testing.T) {
+	msg := buildMessage(buildPacket(true, 1, 1, []byte("a")))
+	msg.AddPacket(buildPacket(true, 1, 2, []byte("b")))
+
+	if !bytes.Equal(msg.Bytes(), []byte("ab")) {
+		t.Error("Should contatenate packets in right order")
+	}
+
+	// When first packet have wrong order (Seq)
+	msg = buildMessage(buildPacket(true, 1, 2, []byte("b")))
+	msg.AddPacket(buildPacket(true, 1, 1, []byte("a")))
+
+	if !bytes.Equal(msg.Bytes(), []byte("ab")) {
+		t.Error("Should contatenate packets in right order")
+	}
+
+	// Should ignore packets with same sequence
+	msg = buildMessage(buildPacket(true, 1, 1, []byte("a")))
+	msg.AddPacket(buildPacket(true, 1, 1, []byte("a")))
+
+	if !bytes.Equal(msg.Bytes(), []byte("a")) {
+		t.Error("Should ignore packet with same Seq")
+	}
+}
+
+func TestTCPMessageSize(t *testing.T) {
+	msg := buildMessage(buildPacket(true, 1, 1, []byte("POST / HTTP/1.1\r\nContent-Length: 2\r\n\r\na")))
+	msg.AddPacket(buildPacket(true, 1, 2, []byte("b")))
+
+	if msg.BodySize() != 2 {
+		t.Error("Should count only body", msg.BodySize())
+	}
+
+	if msg.Size() != 40 {
+		t.Error("Should count all sizes", msg.Size())
+	}
+}
+
+func TestTCPMessageIsFinished(t *testing.T) {
+	methodsWithoutBodies := []string{"GET", "OPTIONS", "HEAD"}
+
+	for _, m := range methodsWithoutBodies {
+		msg := buildMessage(buildPacket(true, 1, 1, []byte(m+" / HTTP/1.1")))
+
+		if !msg.IsFinished() {
+			t.Error(m, " request should be finished")
+		}
+	}
+
+	methodsWithBodies := []string{"POST", "PUT", "PATCH"}
+
+	for _, m := range methodsWithBodies {
+		msg := buildMessage(buildPacket(true, 1, 1, []byte(m+" / HTTP/1.1\r\nContent-Length: 1\r\n\r\na")))
+
+		if !msg.IsFinished() {
+			t.Error(m, " should be finished as body length == content length")
+		}
+
+		msg = buildMessage(buildPacket(true, 1, 1, []byte(m+" / HTTP/1.1\r\nContent-Length: 2\r\n\r\na")))
+
+		if msg.IsFinished() {
+			t.Error(m, " should not be finished as body length != content length")
+		}
+	}
+
+	msg := buildMessage(buildPacket(true, 1, 1, []byte("UNKNOWN / HTTP/1.1\r\n\r\n")))
+	if msg.IsFinished() {
+		t.Error("non http or wrong methods considered as not finished")
+	}
+
+	// Responses
+	msg = buildMessage(buildPacket(false, 1, 1, []byte("HTTP/1.1 200 OK\r\n\r\n")))
+	msg.RequestAck = 1
+	if !msg.IsFinished() {
+		t.Error("Should mark simple response as finished")
+	}
+
+	msg = buildMessage(buildPacket(false, 1, 1, []byte("HTTP/1.1 200 OK\r\n\r\n")))
+	msg.RequestAck = 0
+	if msg.IsFinished() {
+		t.Error("Should not mark responses without associated requests")
+	}
+
+	msg = buildMessage(buildPacket(false, 1, 1, []byte("HTTP/1.1 200 OK\r\nTransfer-Encoding: chunked\r\n\r\n")))
+	msg.RequestAck = 1
+
+	if msg.IsFinished() {
+		t.Error("Should mark chunked response as non finished")
+	}
+
+	msg = buildMessage(buildPacket(false, 1, 1, []byte("HTTP/1.1 200 OK\r\nContent-Length: 0\r\n\r\n")))
+	msg.RequestAck = 1
+
+	if !msg.IsFinished() {
+		t.Error("Should mark Content-Length: 0 respones as finished")
+	}
+
+	msg = buildMessage(buildPacket(false, 1, 1, []byte("HTTP/1.1 200 OK\r\nContent-Length: 1\r\n\r\na")))
+	msg.RequestAck = 1
+
+	if !msg.IsFinished() {
+		t.Error("Should mark valid Content-Length respones as finished")
+	}
+
+	msg = buildMessage(buildPacket(false, 1, 1, []byte("HTTP/1.1 200 OK\r\nContent-Length: 10\r\n\r\na")))
+	msg.RequestAck = 1
+
+	if msg.IsFinished() {
+		t.Error("Should not mark not valid Content-Length respones as finished")
+	}
+}

raw_socket_listener/tcp_packet.go

@@ -1,4 +1,4 @@
-package raw_socket
+package rawSocket
 
 import (
 	"encoding/binary"
@@ -8,19 +8,18 @@ import (
 
 // TCP Flags
 const (
-	TCP_FIN = 1 << iota
-	TCP_SYN
-	TCP_RST
-	TCP_PSH
-	TCP_ACK
-	TCP_URG
-	TCP_ECE
-	TCP_CWR
-	TCP_NS
+	fFIN = 1 << iota
+	fSYN
+	fRST
+	fPSH
+	fACK
+	fURG
+	fECE
+	fCWR
+	fNS
 )
 
-// Simple TCP packet parser
-//
+// TCPPacket provides tcp packet parser
 // Packet structure: http://en.wikipedia.org/wiki/Transmission_Control_Protocol
 type TCPPacket struct {
 	SrcPort    uint16
@@ -34,11 +33,15 @@ type TCPPacket struct {
 	Urgent     uint16
 
 	Data []byte
+
+	Addr string
 }
 
-func ParseTCPPacket(b []byte) (p *TCPPacket) {
+// ParseTCPPacket takes address and tcp payload and returns parsed TCPPacket
+func ParseTCPPacket(addr string, b []byte) (p *TCPPacket) {
 	p = &TCPPacket{Data: b}
 	p.ParseBasic()
+	p.Addr = addr
 
 	return p
 }
@@ -46,8 +49,6 @@ func ParseTCPPacket(b []byte) (p *TCPPacket) {
 // Parse TCP Packet, inspired by: https://github.com/miekg/pcap/blob/master/packet.go
 func (t *TCPPacket) Parse() {
 	t.ParseBasic()
-	t.SrcPort = binary.BigEndian.Uint16(t.Data[0:2])
-	t.DestPort = binary.BigEndian.Uint16(t.Data[2:4])
 	t.Flags = binary.BigEndian.Uint16(t.Data[12:14]) & 0x1FF
 	t.Window = binary.BigEndian.Uint16(t.Data[14:16])
 	t.Checksum = binary.BigEndian.Uint16(t.Data[16:18])
@@ -56,6 +57,8 @@ func (t *TCPPacket) Parse() {
 
 // ParseBasic set of fields
 func (t *TCPPacket) ParseBasic() {
+	t.DestPort = binary.BigEndian.Uint16(t.Data[2:4])
+	t.SrcPort = binary.BigEndian.Uint16(t.Data[0:2])
 	t.Seq = binary.BigEndian.Uint32(t.Data[4:8])
 	t.Ack = binary.BigEndian.Uint32(t.Data[8:12])
 	t.DataOffset = (t.Data[12] & 0xF0) >> 4
@@ -65,26 +68,33 @@ func (t *TCPPacket) ParseBasic() {
 
 // String output for a TCP Packet
 func (t *TCPPacket) String() string {
+	maxLen := len(t.Data)
+	if maxLen > 200 {
+		maxLen = 200
+	}
+
 	return strings.Join([]string{
+		"Addr: " + t.Addr,
 		"Source port: " + strconv.Itoa(int(t.SrcPort)),
 		"Dest port:" + strconv.Itoa(int(t.DestPort)),
 		"Sequence:" + strconv.Itoa(int(t.Seq)),
 		"Acknowledgment:" + strconv.Itoa(int(t.Ack)),
 		"Header len:" + strconv.Itoa(int(t.DataOffset)),
 
-		"Flag ns:" + strconv.FormatBool(t.Flags&TCP_NS != 0),
-		"Flag crw:" + strconv.FormatBool(t.Flags&TCP_CWR != 0),
-		"Flag ece:" + strconv.FormatBool(t.Flags&TCP_ECE != 0),
-		"Flag urg:" + strconv.FormatBool(t.Flags&TCP_URG != 0),
-		"Flag ack:" + strconv.FormatBool(t.Flags&TCP_ACK != 0),
-		"Flag psh:" + strconv.FormatBool(t.Flags&TCP_PSH != 0),
-		"Flag rst:" + strconv.FormatBool(t.Flags&TCP_RST != 0),
-		"Flag syn:" + strconv.FormatBool(t.Flags&TCP_SYN != 0),
-		"Flag fin:" + strconv.FormatBool(t.Flags&TCP_FIN != 0),
+		"Flag ns:" + strconv.FormatBool(t.Flags&fNS != 0),
+		"Flag crw:" + strconv.FormatBool(t.Flags&fCWR != 0),
+		"Flag ece:" + strconv.FormatBool(t.Flags&fECE != 0),
+		"Flag urg:" + strconv.FormatBool(t.Flags&fURG != 0),
+		"Flag ack:" + strconv.FormatBool(t.Flags&fACK != 0),
+		"Flag psh:" + strconv.FormatBool(t.Flags&fPSH != 0),
+		"Flag rst:" + strconv.FormatBool(t.Flags&fRST != 0),
+		"Flag syn:" + strconv.FormatBool(t.Flags&fSYN != 0),
+		"Flag fin:" + strconv.FormatBool(t.Flags&fFIN != 0),
 
 		"Window size:" + strconv.Itoa(int(t.Window)),
 		"Checksum:" + strconv.Itoa(int(t.Checksum)),
 
-		"Data:" + string(t.Data),
+		"Data size:" + strconv.Itoa(len(t.Data)),
+		"Data:" + string(t.Data[:maxLen]),
 	}, "\n")
 }

settings.go

@@ -1,39 +1,60 @@
-package gor
+package main
 
 import (
 	"flag"
 	"fmt"
-	"log"
 	"os"
+	"sync"
+	"time"
 )
 
-const (
-	VERSION = "0.8"
-)
+var VERSION string
 
+// MultiOption allows to specify multiple flags with same name and collects all values into array
+type MultiOption []string
+
+func (h *MultiOption) String() string {
+	return fmt.Sprint(*h)
+}
+
+// Set gets called multiple times for each flag with same name
+func (h *MultiOption) Set(value string) error {
+	*h = append(*h, value)
+	return nil
+}
+
+// AppSettings is the struct of main configuration
 type AppSettings struct {
 	verbose bool
+	debug   bool
+	stats   bool
 
 	splitOutput bool
 
 	inputDummy  MultiOption
 	outputDummy MultiOption
 
-	inputTCP  MultiOption
-	outputTCP MultiOption
+	inputTCP       MultiOption
+	outputTCP      MultiOption
+	outputTCPStats bool
 
 	inputFile  MultiOption
 	outputFile MultiOption
 
-	inputRAW MultiOption
+	inputRAW       MultiOption
+	inputRAWEngine string
 
-	outputHTTP              MultiOption
-	outputHTTPHeaders       HTTPHeaders
-	outputHTTPMethods       HTTPMethods
-	outputHTTPElasticSearch string
+	middleware string
+
+	inputHTTP  MultiOption
+	outputHTTP MultiOption
+
+	outputHTTPConfig HTTPOutputConfig
+	modifierConfig   HTTPModifierConfig
 }
 
-var Settings AppSettings = AppSettings{}
+// Settings holds Gor configuration
+var Settings AppSettings
 
 func usage() {
 	fmt.Printf("Gor is a simple http traffic replication tool written in Go. Its main goal is to replay traffic from production servers to staging and dev environments.\nProject page: https://github.com/buger/gor\nAuthor: <Leonid Bugaev> leonsbox@gmail.com\nCurrent Version: %s\n\n", VERSION)
@@ -44,7 +65,9 @@ func usage() {
 func init() {
 	flag.Usage = usage
 
-	flag.BoolVar(&Settings.verbose, "verbose", false, "Turn on verbose/debug output")
+	flag.BoolVar(&Settings.verbose, "verbose", false, "Turn on more verbose output")
+	flag.BoolVar(&Settings.debug, "debug", false, "Turn on debug output, shows all intercepted traffic. Works only when with `verbose` flag")
+	flag.BoolVar(&Settings.stats, "stats", false, "Turn on queue stats output")
 
 	flag.BoolVar(&Settings.splitOutput, "split-output", false, "By default each output gets same traffic. If set to `true` it splits traffic equally among all outputs.")
 
@@ -53,20 +76,70 @@ func init() {
 
 	flag.Var(&Settings.inputTCP, "input-tcp", "Used for internal communication between Gor instances. Example: \n\t# Receive requests from other Gor instances on 28020 port, and redirect output to staging\n\tgor --input-tcp :28020 --output-http staging.com")
 	flag.Var(&Settings.outputTCP, "output-tcp", "Used for internal communication between Gor instances. Example: \n\t# Listen for requests on 80 port and forward them to other Gor instance on 28020 port\n\tgor --input-raw :80 --output-tcp replay.local:28020")
+	flag.BoolVar(&Settings.outputTCPStats, "output-tcp-stats", false, "Report TCP output queue stats to console every 5 seconds.")
 
 	flag.Var(&Settings.inputFile, "input-file", "Read requests from file: \n\tgor --input-file ./requests.gor --output-http staging.com")
 	flag.Var(&Settings.outputFile, "output-file", "Write incoming requests to file: \n\tgor --input-raw :80 --output-file ./requests.gor")
 
 	flag.Var(&Settings.inputRAW, "input-raw", "Capture traffic from given port (use RAW sockets and require *sudo* access):\n\t# Capture traffic from 8080 port\n\tgor --input-raw :8080 --output-http staging.com")
 
+	flag.StringVar(&Settings.inputRAWEngine, "input-raw-engine", "libpcap", "Intercept traffic using `libpcap` (default), and `raw_socket`")
+
+	flag.StringVar(&Settings.middleware, "middleware", "", "Used for modifying traffic using external command")
+
+	flag.Var(&Settings.inputHTTP, "input-http", "Read requests from HTTP, should be explicitly sent from your application:\n\t# Listen for http on 9000\n\tgor --input-http :9000 --output-http staging.com")
+
 	flag.Var(&Settings.outputHTTP, "output-http", "Forwards incoming requests to given http address.\n\t# Redirect all incoming requests to staging.com address \n\tgor --input-raw :80 --output-http http://staging.com")
-	flag.Var(&Settings.outputHTTPHeaders, "output-http-header", "Inject additional headers to http reqest:\n\tgor --input-raw :8080 --output-http staging.com --output-http-header 'User-Agent: Gor'")
-	flag.Var(&Settings.outputHTTPMethods, "output-http-method", "Whitelist of HTTP methods to replay. Anything else will be dropped:\n\tgor --input-raw :8080 --output-http staging.com --output-http-method GET --output-http-method OPTIONS")
-	flag.StringVar(&Settings.outputHTTPElasticSearch, "output-http-elasticsearch", "", "Send request and response stats to ElasticSearch:\n\tgor --input-raw :8080 --output-http staging.com --output-http-elasticsearch 'es_host:api_port/index_name'")
+	flag.IntVar(&Settings.outputHTTPConfig.workers, "output-http-workers", 0, "Gor uses dynamic worker scaling by default.  Enter a number to run a set number of workers.")
+	flag.IntVar(&Settings.outputHTTPConfig.redirectLimit, "output-http-redirects", 0, "Enable how often redirects should be followed.")
+	flag.DurationVar(&Settings.outputHTTPConfig.Timeout, "output-http-timeout", 0, "Specify HTTP request/response timeout. By default 5s. Example: --output-http-timeout 30s")
+
+	flag.BoolVar(&Settings.outputHTTPConfig.stats, "output-http-stats", false, "Report http output queue stats to console every 5 seconds.")
+	flag.BoolVar(&Settings.outputHTTPConfig.OriginalHost, "http-original-host", false, "Normally gor replaces the Host http header with the host supplied with --output-http.  This option disables that behavior, preserving the original Host header.")
+	flag.BoolVar(&Settings.outputHTTPConfig.Debug, "output-http-debug", false, "Enables http debug output.")
+
+	flag.StringVar(&Settings.outputHTTPConfig.elasticSearch, "output-http-elasticsearch", "", "Send request and response stats to ElasticSearch:\n\tgor --input-raw :8080 --output-http staging.com --output-http-elasticsearch 'es_host:api_port/index_name'")
+
+	flag.Var(&Settings.modifierConfig.headers, "http-set-header", "Inject additional headers to http reqest:\n\tgor --input-raw :8080 --output-http staging.com --http-set-header 'User-Agent: Gor'")
+	flag.Var(&Settings.modifierConfig.headers, "output-http-header", "WARNING: `--output-http-header` DEPRECATED, use `--http-set-header` instead")
+
+	flag.Var(&Settings.modifierConfig.params, "http-set-param", "Set request url param, if param already exists it will be overwritten:\n\tgor --input-raw :8080 --output-http staging.com --http-set-param api_key=1")
+
+	flag.Var(&Settings.modifierConfig.methods, "http-allow-method", "Whitelist of HTTP methods to replay. Anything else will be dropped:\n\tgor --input-raw :8080 --output-http staging.com --http-allow-method GET --http-allow-method OPTIONS")
+	flag.Var(&Settings.modifierConfig.methods, "output-http-method", "WARNING: `--output-http-method` DEPRECATED, use `--http-allow-method` instead")
+
+	flag.Var(&Settings.modifierConfig.urlRegexp, "http-allow-url", "A regexp to match requests against. Filter get matched against full url with domain. Anything else will be dropped:\n\t gor --input-raw :8080 --output-http staging.com --http-allow-url ^www.")
+	flag.Var(&Settings.modifierConfig.urlRegexp, "output-http-url-regexp", "WARNING: `--output-http-url-regexp` DEPRECATED, use `--http-allow-url` instead")
+
+	flag.Var(&Settings.modifierConfig.urlNegativeRegexp, "http-disallow-url", "A regexp to match requests against. Filter get matched against full url with domain. Anything else will be forwarded:\n\t gor --input-raw :8080 --output-http staging.com --http-disallow-url ^www.")
+
+	flag.Var(&Settings.modifierConfig.urlRewrite, "http-rewrite-url", "Rewrite the request url based on a mapping:\n\tgor --input-raw :8080 --output-http staging.com --http-rewrite-url /v1/user/([^\\/]+)/ping:/v2/user/$1/ping")
+	flag.Var(&Settings.modifierConfig.urlRewrite, "output-http-rewrite-url", "WARNING: `--output-http-rewrite-url` DEPRECATED, use `--http-rewrite-url` instead")
+
+	flag.Var(&Settings.modifierConfig.headerFilters, "http-allow-header", "A regexp to match a specific header against. Requests with non-matching headers will be dropped:\n\t gor --input-raw :8080 --output-http staging.com --http-allow-header api-version:^v1")
+	flag.Var(&Settings.modifierConfig.headerFilters, "output-http-header-filter", "WARNING: `--output-http-header-filter` DEPRECATED, use `--http-allow-header` instead")
+
+	flag.Var(&Settings.modifierConfig.headerFilters, "http-disallow-header", "A regexp to match a specific header against. Requests with matching headers will be dropped:\n\t gor --input-raw :8080 --output-http staging.com --http-disallow-header \"User-Agent: Replayed by Gor\"")
+
+	flag.Var(&Settings.modifierConfig.headerHashFilters, "http-header-limiter", "Takes a fraction of requests, consistently taking or rejecting a request based on the FNV32-1A hash of a specific header:\n\t gor --input-raw :8080 --output-http staging.com --http-header-imiter user-id:25%")
+	flag.Var(&Settings.modifierConfig.headerHashFilters, "output-http-header-hash-filter", "WARNING: `output-http-header-hash-filter` DEPRECATED, use `--http-header-hash-limiter` instead")
+
+	flag.Var(&Settings.modifierConfig.paramHashFilters, "http-param-limiter", "Takes a fraction of requests, consistently taking or rejecting a request based on the FNV32-1A hash of a specific GET param:\n\t gor --input-raw :8080 --output-http staging.com --http-param-limiter user_id:25%")
 }
 
+var previousDebugTime int64
+var debugMutex sync.Mutex
+
+// Debug gets called only if --verbose flag specified
 func Debug(args ...interface{}) {
 	if Settings.verbose {
-		log.Println(args...)
+		debugMutex.Lock()
+		now := time.Now()
+		diff := float64(now.UnixNano()-previousDebugTime) / 1000000
+		previousDebugTime = now.UnixNano()
+		debugMutex.Unlock()
+
+		fmt.Printf("[DEBUG][PID %d][%d][%fms] ", os.Getpid(), now.UnixNano(), diff)
+		fmt.Println(args...)
 	}
 }

settings_headers.go

@@ -1,32 +0,0 @@
-package gor
-
-import (
-	"errors"
-	"fmt"
-	"strings"
-)
-
-type HTTPHeaders []HTTPHeader
-type HTTPHeader struct {
-	Name  string
-	Value string
-}
-
-func (h *HTTPHeaders) String() string {
-	return fmt.Sprint(*h)
-}
-
-func (h *HTTPHeaders) Set(value string) error {
-	v := strings.SplitN(value, ":", 2)
-	if len(v) != 2 {
-		return errors.New("Expected `Key: Value`")
-	}
-
-	header := HTTPHeader{
-		strings.TrimSpace(v[0]),
-		strings.TrimSpace(v[1]),
-	}
-
-	*h = append(*h, header)
-	return nil
-}

settings_methods.go

@@ -1,26 +0,0 @@
-package gor
-
-import (
-	"fmt"
-	"strings"
-)
-
-type HTTPMethods []string
-
-func (h *HTTPMethods) String() string {
-	return fmt.Sprint(*h)
-}
-
-func (h *HTTPMethods) Set(value string) error {
-	*h = append(*h, strings.ToUpper(value))
-	return nil
-}
-
-func (h *HTTPMethods) Contains(value string) bool {
-	for _, method := range *h {
-		if value == method {
-			return true
-		}
-	}
-	return false
-}

settings_methods_test.go

@@ -1,24 +0,0 @@
-package gor
-
-import (
-	"testing"
-)
-
-func TestHTTPMethods(t *testing.T) {
-	methods := HTTPMethods{}
-
-	methods.Set("lower")
-	methods.Set("UPPER")
-
-	if !methods.Contains("LOWER") {
-		t.Error("Does not contain LOWER")
-	}
-
-	if !methods.Contains("UPPER") {
-		t.Error("Does not contain UPPER")
-	}
-
-	if methods.Contains("ABSENT") {
-		t.Error("Does contain ABSENT")
-	}
-}

settings_option.go

@@ -1,16 +0,0 @@
-package gor
-
-import (
-	"fmt"
-)
-
-type MultiOption []string
-
-func (h *MultiOption) String() string {
-	return fmt.Sprint(*h)
-}
-
-func (h *MultiOption) Set(value string) error {
-	*h = append(*h, value)
-	return nil
-}

test_input.go

@@ -1,9 +1,17 @@
-package gor
+package main
 
+import (
+	"crypto/rand"
+	"encoding/base64"
+	"time"
+)
+
+// TestInput used for testing purpose, it allows emitting requests on demand
 type TestInput struct {
 	data chan []byte
 }
 
+// NewTestInput constructor for TestInput
 func NewTestInput() (i *TestInput) {
 	i = new(TestInput)
 	i.data = make(chan []byte, 100)
@@ -13,19 +21,53 @@ func NewTestInput() (i *TestInput) {
 
 func (i *TestInput) Read(data []byte) (int, error) {
 	buf := <-i.data
-	copy(data, buf)
 
-	return len(buf), nil
+	header := payloadHeader(RequestPayload, uuid(), time.Now().UnixNano())
+	copy(data[0:len(header)], header)
+	copy(data[len(header):], buf)
+
+	return len(buf) + len(header), nil
 }
 
+// EmitGET emits GET request without headers
 func (i *TestInput) EmitGET() {
 	i.data <- []byte("GET / HTTP/1.1\r\n\r\n")
 }
 
+// EmitPOST emits POST request with Content-Length
 func (i *TestInput) EmitPOST() {
-	i.data <- []byte("POST /pub/WWW/ HTTP/1.1\nHost: www.w3.org\r\n\r\na=1&b=2\r\n\r\n")
+	i.data <- []byte("POST /pub/WWW/ HTTP/1.1\r\nContent-Length: 7\r\nHost: www.w3.org\r\n\r\na=1&b=2")
 }
 
+// EmitChunkedPOST emits POST request with `Transfer-Encoding: chunked` and chunked body
+func (i *TestInput) EmitChunkedPOST() {
+	i.data <- []byte("POST /pub/WWW/ HTTP/1.1\r\nHost: www.w3.org\r\nTransfer-Encoding: chunked\r\n\r\n4\r\nWiki\r\n5\r\npedia\r\ne\r\n in\r\n\r\nchunks.\r\n0\r\n\r\n")
+}
+
+// EmitLargePOST emits POST request with large payload (5mb)
+func (i *TestInput) EmitLargePOST() {
+	size := 5 * 1024 * 1024 // 5 MB
+	rb := make([]byte, size)
+	rand.Read(rb)
+
+	rs := base64.URLEncoding.EncodeToString(rb)
+
+	i.data <- []byte("POST / HTTP/1.1\nHost: www.w3.org\nContent-Length:5242880\r\n\r\n" + rs)
+	Debug("Sent large POST")
+}
+
+// EmitSizedPOST emit a POST with a payload set to a supplied size
+func (i *TestInput) EmitSizedPOST(payloadSize int) {
+	rb := make([]byte, payloadSize)
+	rand.Read(rb)
+
+	rs := base64.URLEncoding.EncodeToString(rb)
+
+	i.data <- []byte("POST / HTTP/1.1\nHost: www.w3.org\nContent-Length:5242880\r\n\r\n" + rs)
+	Debug("Sent large POST")
+}
+
+// EmitOPTIONS emits OPTIONS request, similar to GET
 func (i *TestInput) EmitOPTIONS() {
 	i.data <- []byte("OPTIONS / HTTP/1.1\nHost: www.w3.org\r\n\r\n")
 }

test_output.go

@@ -1,11 +1,13 @@
-package gor
+package main
 
 type writeCallback func(data []byte)
 
+// TestOutput used in testing to intercept any output into callback
 type TestOutput struct {
 	cb writeCallback
 }
 
+// NewTestOutput constructor for TestOutput, accepts callback which get called on each incoming Write
 func NewTestOutput(cb writeCallback) (i *TestOutput) {
 	i = new(TestOutput)
 	i.cb = cb