From 7801dc7cb32e5df240b1a88b00ef52a2c08887d5 Mon Sep 17 00:00:00 2001
From: Gleb Smirnoff <glebius@FreeBSD.org>
Date: Wed, 11 Oct 2006 15:27:13 +0000
Subject: [PATCH] Recognize 802.1q frames in Ethernet input and process them.

PR:		kern/101162
Submitted by:	CoolDavid (Tseng Guo-Fu) <cooldavid cdpa.nsysu.edu.tw>
---
 sys/netgraph/netflow/ng_netflow.c | 30 +++++++++++++++++++++++++++++-
 1 file changed, 29 insertions(+), 1 deletion(-)

diff --git a/sys/netgraph/netflow/ng_netflow.c b/sys/netgraph/netflow/ng_netflow.c
index df5caa391dc..f0cb8679269 100644
--- a/sys/netgraph/netflow/ng_netflow.c
+++ b/sys/netgraph/netflow/ng_netflow.c
@@ -42,6 +42,7 @@ static const char rcs_id[] =
 #include <net/ethernet.h>
 #include <net/if_arp.h>
 #include <net/if_var.h>
+#include <net/if_vlan_var.h>
 #include <net/bpf.h>
 #include <netinet/in.h>
 #include <netinet/in_systm.h>
@@ -514,6 +515,19 @@ ng_netflow_rcvdata (hook_p hook, item_p item)
 			eh = mtod(m, struct ether_header *);
 			ip = (struct ip *)(eh + 1);
 			break;
+		case ETHERTYPE_VLAN:
+		    {
+			struct ether_vlan_header *evh;
+
+			M_CHECK(sizeof(struct ether_vlan_header) -
+			    sizeof(struct ether_header));
+			evh = mtod(m, struct ether_vlan_header *);
+			if (ntohs(evh->evl_proto) == ETHERTYPE_IP) {
+				M_CHECK(sizeof(struct ip));
+				ip = (struct ip *)(evh + 1);
+				break;
+			}
+		    }
 		default:
 			goto bypass;	/* pass this frame */
 		}
@@ -551,7 +565,21 @@ ng_netflow_rcvdata (hook_p hook, item_p item)
 		struct ether_header *eh;
 
 		eh = mtod(m, struct ether_header *);
-		ip = (struct ip *)(eh + 1);
+		switch (ntohs(eh->ether_type)) {
+		case ETHERTYPE_IP:
+			ip = (struct ip *)(eh + 1);
+			break;
+		case ETHERTYPE_VLAN:
+		    {
+			struct ether_vlan_header *evh;
+
+			evh = mtod(m, struct ether_vlan_header *);
+			ip = (struct ip *)(evh + 1);
+			break;
+		     }
+		default:
+			panic("ng_netflow entered deadcode");
+		}
 		break;
 	     }
 	case DLT_RAW: