From 07a4ef626cc289b6c798f872a62d3b802e1880fd Mon Sep 17 00:00:00 2001
From: Leonid Bugaev <leonsbox@gmail.com>
Date: Wed, 9 Jun 2021 09:46:41 +0300
Subject: [PATCH] Add windows support (#940)

For a long time there were no official binaries for the windows platform.
One of the reasons is the complexities of the build toolchain. Not only CGO is required, but also installing the needed libraries and header files, not talking about mingw and etc.

2 weeks ago [golang-crossbuild](https://github.com/elastic/golang-crossbuild) project added native support for Libpcap based applications.
Windows support is based on the WinPcap which is a bit (a lot) outdated, BUT, since we depend only on its interface, it is still possible to use projects like npcap https://nmap.org/npcap/#download.

Npcap needs be installed with WinPcap compatibe mode (checkbox during installation)
It is also possibe install it in silent mode like this: `npcap-0.86.exe /S /winpcap_mode=yes`

After PR merge, will be updated related documentation.

Additionally fix dependency on "unix" package (apparently it can be totally replaced using universal syscall package)
---
 .gitignore         |  1 +
 Makefile           | 18 ++++++++++++++++--
 capture/capture.go |  4 ++--
 3 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/.gitignore b/.gitignore
index 04a6cc6..fda9013 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,6 +3,7 @@
 *.rpm
 *.dep
 *.pkg
+*.exe
 
 *.out
 
diff --git a/Makefile b/Makefile
index ad8e870..a313231 100644
--- a/Makefile
+++ b/Makefile
@@ -23,7 +23,7 @@ FPMCOMMON= \
     -s dir \
     -C /tmp/gor-build \
 
-release: release-x64 release-mac
+release: release-x64 release-mac release-windows
 
 release-bin:
 	docker run -v `pwd`:$(SOURCE_PATH) -t --env GOOS=linux --env GOARCH=amd64  -i $(CONTAINER) go build -o $(BIN_NAME) -tags netgo $(LDFLAGS)
@@ -58,11 +58,25 @@ release-mac:
 	fpm $(FPMCOMMON) -a amd64 -t osxpkg ./=/usr/local/bin
 	rm -rf /tmp/gor-build
 
+release-windows:
+	echo $(pwd)
+	docker run -it --rm \
+	  -v `pwd`:/go/src/github.com/buger/goreplay \
+	  -w /go/src/github.com/buger/goreplay \
+	  -e CGO_ENABLED=1 \
+	  docker.elastic.co/beats-dev/golang-crossbuild:1.16.4-main \
+	  --build-cmd "VERSION=make build" \
+	  -p "windows/amd64"
+
+	mv ./gor ./gor-$(VERSION)$(PREFIX).exe
+
+build:
+	go build -o $(BIN_NAME) $(LDFLAGS)
 
 install:
 	go install $(MAC_LDFLAGS)
 
-build:
+build-env:
 	docker build -t $(CONTAINER) -f Dockerfile.dev .
 
 profile:
diff --git a/capture/capture.go b/capture/capture.go
index 16a8101..1901c75 100644
--- a/capture/capture.go
+++ b/capture/capture.go
@@ -10,6 +10,7 @@ import (
 	"os"
 	"runtime"
 	"sync"
+	"syscall"
 	"time"
 
 	"github.com/buger/goreplay/size"
@@ -18,7 +19,6 @@ import (
 	"github.com/google/gopacket"
 	"github.com/google/gopacket/layers"
 	"github.com/google/gopacket/pcap"
-	"golang.org/x/sys/unix"
 )
 
 // PacketHandler is a function that is used to handle packets
@@ -335,7 +335,7 @@ func (l *Listener) read(handler PacketHandler) {
 					if enext, ok := err.(pcap.NextError); ok && enext == pcap.NextErrorTimeoutExpired {
 						continue
 					}
-					if eno, ok := err.(unix.Errno); ok && eno.Temporary() {
+					if eno, ok := err.(syscall.Errno); ok && eno.Temporary() {
 						continue
 					}
 					if enet, ok := err.(*net.OpError); ok && (enet.Temporary() || enet.Timeout()) {