From 51860e130cb25902e332fc6a992d04f96ebad312 Mon Sep 17 00:00:00 2001
From: Leonid Bugaev <leonsbox@gmail.com>
Date: Mon, 20 Jun 2016 19:32:13 +0300
Subject: [PATCH] Add support for known network layers

Fix #310
Close #311
---
 raw_socket_listener/listener.go | 30 ++++++++++++++++++++++--------
 1 file changed, 22 insertions(+), 8 deletions(-)

diff --git a/raw_socket_listener/listener.go b/raw_socket_listener/listener.go
index fd4f2c5..59bbcf9 100644
--- a/raw_socket_listener/listener.go
+++ b/raw_socket_listener/listener.go
@@ -351,16 +351,30 @@ func (t *Listener) readPcap() {
 					continue
 				}
 
-				if decoder == layers.LinkTypeEthernet {
-					// Skip ethernet layer, 14 bytes
-					data = packet.Data()[14:]
-				} else if decoder == layers.LinkTypeNull || decoder == layers.LinkTypeLoop {
-					data = packet.Data()[4:]
-				} else {
-					log.Println("Unknown packet layer", packet)
-					break
+				// We should remove network layer before parsing TCP/IP data
+				var of int
+				switch decoder {
+					case layers.LinkTypeEthernet:
+						of = 14
+					case layers.LinkTypePPP:
+						of = 1
+					case layers.LinkTypeFDDI:
+						of = 13
+					case layers.LinkTypeNull:
+						of = 4
+					case layers.LinkTypeLoop:
+						of = 4
+					case layers.LinkTypeRaw:
+						of = 0
+					case layers.LinkTypeLinuxSLL:
+						of = 16
+					default:
+						log.Println("Unknown packet layer", packet)
+						break
 				}
 
+				data = packet.Data()[of:]
+
 				version := uint8(data[0]) >> 4
 
 				if version == 4 {