Add support for VLAN (IEEE 802.1Q) frames.

Built after libpcap-0.7 from tcpdump-3.7.1.

Approved by: Jason R. Thorpe <thorpej@netbsd.org>

lib/libpcap/ethertype.h

@@ -1,4 +1,4 @@
-/*	$NetBSD: ethertype.h,v 1.5 2000/04/14 14:26:35 itojun Exp $	*/
+/*	$NetBSD: ethertype.h,v 1.6 2002/12/19 16:33:47 hannken Exp $	*/
 
 /*
  * Copyright (c) 1993, 1994, 1996
@@ -73,6 +73,9 @@
 #ifndef ETHERTYPE_AARP
 #define ETHERTYPE_AARP		0x80f3
 #endif
+#ifndef ETHERTYPE_8021Q
+#define ETHERTYPE_8021Q		0x8100
+#endif
 #ifndef ETHERTYPE_IPV6
 #define ETHERTYPE_IPV6		0x80f3
 #endif

lib/libpcap/gencode.c

@@ -1,4 +1,4 @@
-/*	$NetBSD: gencode.c,v 1.32 2002/09/22 16:13:01 thorpej Exp $	*/
+/*	$NetBSD: gencode.c,v 1.33 2002/12/19 16:33:47 hannken Exp $	*/
 
 /*
  * Copyright (c) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997
@@ -26,7 +26,7 @@
 static const char rcsid[] =
     "@(#) Header: gencode.c,v 1.93 97/06/12 14:22:47 leres Exp  (LBL)";
 #else
-__RCSID("$NetBSD: gencode.c,v 1.32 2002/09/22 16:13:01 thorpej Exp $");
+__RCSID("$NetBSD: gencode.c,v 1.33 2002/12/19 16:33:47 hannken Exp $");
 #endif
 #endif
 
@@ -80,6 +80,10 @@ struct rtentry;
 static jmp_buf top_ctx;
 static pcap_t *bpf_pcap;
 
+/* Hack for updating VLAN offsets. */
+static u_int	orig_linktype = (u_int)-1;
+static u_int	orig_nl = (u_int)-1;
+
 /* XXX */
 #ifdef PCAP_FDDIPAD
 int	pcap_fddipad = PCAP_FDDIPAD;
@@ -547,6 +551,8 @@ init_linktype(type)
 	int type;
 {
 	linktype = type;
+	orig_linktype = -1;
+	orig_nl = -1;
 
 	if (DLT_IS_RAWAF(type)) {
 		off_linktype = -1;
@@ -3039,3 +3045,49 @@ gen_ahostop(eaddr, dir)
 	abort();
 	/* NOTREACHED */
 }
+
+/*
+ * support IEEE 802.1Q VLAN trunk over ethernet
+ */
+struct block *
+gen_vlan(vlan_num)
+	int vlan_num;
+{
+	struct	block	*b0;
+
+	/*
+	 * Change the offsets to point to the type and data fields within
+	 * the VLAN packet.  This is somewhat of a kludge.
+	 */
+	if (orig_nl == (u_int)-1) {
+		orig_linktype = off_linktype;	/* save original values */
+		orig_nl = off_nl;
+
+		switch (linktype) {
+
+		case DLT_EN10MB:
+			off_linktype = 16;
+			off_nl = 18;
+			break;
+
+		default:
+			bpf_error("no VLAN support for data link type %d",
+				  linktype);
+			/*NOTREACHED*/
+		}
+	}
+
+	/* check for VLAN */
+	b0 = gen_cmp(orig_linktype, BPF_H, (bpf_int32)ETHERTYPE_8021Q);
+
+	/* If a specific VLAN is requested, check VLAN id */
+	if (vlan_num >= 0) {
+		struct block *b1;
+
+		b1 = gen_cmp(orig_nl, BPF_H, (bpf_int32)vlan_num);
+		gen_and(b0, b1);
+		b0 = b1;
+	}
+
+	return (b0);
+}

lib/libpcap/gencode.h

@@ -1,4 +1,4 @@
-/*	$NetBSD: gencode.h,v 1.11 2001/01/19 09:02:40 kleink Exp $	*/
+/*	$NetBSD: gencode.h,v 1.12 2002/12/19 16:33:48 hannken Exp $	*/
 
 /*
  * Copyright (c) 1990, 1991, 1992, 1993, 1994, 1995, 1996
@@ -179,6 +179,7 @@ struct block *gen_byteop(int, int, int);
 struct block *gen_broadcast(int);
 struct block *gen_multicast(int);
 struct block *gen_inbound(int);
+struct block *gen_vlan(int);
 
 void bpf_optimize(struct block **);
 #if __STDC__

lib/libpcap/grammar.y

@@ -1,5 +1,5 @@
 %{
-/*	$NetBSD: grammar.y,v 1.8 2001/01/19 09:02:40 kleink Exp $	*/
+/*	$NetBSD: grammar.y,v 1.9 2002/12/19 16:33:48 hannken Exp $	*/
 
 /*
  * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996
@@ -28,7 +28,7 @@
 static const char rcsid[] =
     "@(#) Header: grammar.y,v 1.56 96/11/02 21:54:55 leres Exp  (LBL)";
 #else
-__RCSID("$NetBSD: grammar.y,v 1.8 2001/01/19 09:02:40 kleink Exp $");
+__RCSID("$NetBSD: grammar.y,v 1.9 2002/12/19 16:33:48 hannken Exp $");
 #endif
 #endif
 
@@ -124,6 +124,7 @@ pcap_parse()
 %token	LSH RSH
 %token  LEN
 %token  IPV6 ICMPV6 AH ESP
+%token	VLAN
 
 %type	<s> ID
 %type	<e> EID
@@ -282,6 +283,8 @@ other:	  pqual TK_BROADCAST	{ $$ = gen_broadcast($1); }
 	| BYTE NUM byteop NUM	{ $$ = gen_byteop($3, $2, $4); }
 	| INBOUND		{ $$ = gen_inbound(0); }
 	| OUTBOUND		{ $$ = gen_inbound(1); }
+	| VLAN pnum		{ $$ = gen_vlan($2); }
+	| VLAN			{ $$ = gen_vlan(-1); }
 	;
 relop:	  '>'			{ $$ = BPF_JGT; }
 	| GEQ			{ $$ = BPF_JGE; }

lib/libpcap/scanner.l

@@ -1,5 +1,5 @@
 %{
-/*	$NetBSD: scanner.l,v 1.14 2001/01/19 09:02:40 kleink Exp $	*/
+/*	$NetBSD: scanner.l,v 1.15 2002/12/19 16:33:48 hannken Exp $	*/
 
 /*
  * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997
@@ -28,7 +28,7 @@
 static const char rcsid[] =
     "@(#) Header: scanner.l,v 1.56 97/07/21 13:31:50 leres Exp  (LBL)";
 #else
-__RCSID("$NetBSD: scanner.l,v 1.14 2001/01/19 09:02:40 kleink Exp $");
+__RCSID("$NetBSD: scanner.l,v 1.15 2002/12/19 16:33:48 hannken Exp $");
 #endif
 #endif
 
@@ -229,6 +229,7 @@ not		return '!';
 len|length	return LEN;
 inbound		return INBOUND;
 outbound	return OUTBOUND;
+vlan		return VLAN;
 
 [ \n\t]			;
 [+\-*/:\[\]!<>()&|=]	return yytext[0];