gre, erspan: add an ERSPAN dissector and have the GRE dissector call it.

This is from the OpenBSD tcpdump.

Fixes #1040.

Sort the .c list in CMakeLists.txt while we're at it.

Author: guyharris

CMakeLists.txt

@@ -1066,8 +1066,8 @@ set(NETDISSECT_SOURCE_LIST_C
     netdissect.c
     netdissect-alloc.c
     nlpid.c
-    oui.c
     ntp.c
+    oui.c
     parsenfsfh.c
     print.c
     print-802_11.c
@@ -1109,6 +1109,7 @@ set(NETDISSECT_SOURCE_LIST_C
     print-egp.c
     print-eigrp.c
     print-enc.c
+    print-erspan.c
     print-esp.c
     print-ether.c
     print-fddi.c

Makefile.in

@@ -131,6 +131,7 @@ LIBNETDISSECT_SRC=\
 	print-egp.c \
 	print-eigrp.c \
 	print-enc.c \
+	print-erspan.c \
 	print-esp.c \
 	print-ether.c \
 	print-fddi.c \

netdissect.h

@@ -631,6 +631,7 @@ extern void eap_print(netdissect_options *, const u_char *, u_int);
 extern void eapol_print(netdissect_options *, const u_char *);
 extern void egp_print(netdissect_options *, const u_char *, u_int);
 extern void eigrp_print(netdissect_options *, const u_char *, u_int);
+extern void erspan_print(netdissect_options *, uint16_t, const u_char *, u_int);
 extern void esp_print(netdissect_options *, const u_char *, u_int, const u_char *, u_int, int, u_int);
 extern u_int ether_print(netdissect_options *, const u_char *, u_int, u_int, void (*)(netdissect_options *, const u_char *), const u_char *);
 extern u_int ether_switch_tag_print(netdissect_options *, const u_char *, u_int, u_int, void (*)(netdissect_options *, const u_char *), u_int);

print-erspan.c

@@ -0,0 +1,143 @@
+/*	$OpenBSD: print-gre.c,v 1.6 2002/10/30 03:04:04 fgsch Exp $	*/
+
+/*
+ * Copyright (c) 2002 Jason L. Wright ([email protected])
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/* \summary: Cisco ERSPAN printer */
+
+/*
+ * Specifications: I-D draft-foschiano-erspan-03.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include "netdissect-stdinc.h"
+
+#define ND_LONGJMP_FROM_TCHECK
+#include "netdissect.h"
+#include "extract.h"
+
+#define ERSPAN2_VER_SHIFT	28
+#define ERSPAN2_VER_MASK	(0xfU << ERSPAN2_VER_SHIFT)
+#define ERSPAN2_VER		(0x1U << ERSPAN2_VER_SHIFT)
+#define ERSPAN2_VLAN_SHIFT	16
+#define ERSPAN2_VLAN_MASK	(0xfffU << ERSPAN2_VLAN_SHIFT)
+#define ERSPAN2_COS_SHIFT	13
+#define ERSPAN2_COS_MASK	(0x7U << ERSPAN2_COS_SHIFT)
+#define ERSPAN2_EN_SHIFT	11
+#define ERSPAN2_EN_MASK		(0x3U << ERSPAN2_EN_SHIFT)
+#define ERSPAN2_EN_NONE		(0x0U << ERSPAN2_EN_SHIFT)
+#define ERSPAN2_EN_ISL		(0x1U << ERSPAN2_EN_SHIFT)
+#define ERSPAN2_EN_DOT1Q	(0x2U << ERSPAN2_EN_SHIFT)
+#define ERSPAN2_EN_VLAN		(0x3U << ERSPAN2_EN_SHIFT)
+#define ERSPAN2_T_SHIFT		10
+#define ERSPAN2_T_MASK		(0x1U << ERSPAN2_T_SHIFT)
+#define ERSPAN2_SID_SHIFT	0
+#define ERSPAN2_SID_MASK	(0x3ffU << ERSPAN2_SID_SHIFT)
+
+#define ERSPAN2_INDEX_SHIFT	0
+#define ERSPAN2_INDEX_MASK	(0xfffffU << ERSPAN2_INDEX_SHIFT)
+
+/*
+ * XXX - eh?
+ */
+#define	GRE_SP		0x1000		/* sequence# present */
+
+void
+erspan_print(netdissect_options *ndo, uint16_t flags, const u_char *bp, u_int len)
+{
+	uint32_t hdr, ver, vlan, cos, en, sid, index;
+
+	ndo->ndo_protocol = "erspan";
+	nd_print_protocol(ndo);
+
+	if (!(flags & GRE_SP)) {
+		ND_PRINT(" I: ");
+		ether_print(ndo, bp, len, ND_BYTES_AVAILABLE_AFTER(bp), NULL, NULL);
+		return;
+	}
+
+	ND_ICHECK_U(len, <, 4);
+	hdr = GET_BE_U_4(bp);
+	bp += 4;
+	len -= 4;
+
+	ver = hdr & ERSPAN2_VER_MASK;
+	if (ver != ERSPAN2_VER) {
+		ver >>= ERSPAN2_VER_SHIFT;
+		ND_PRINT(" erspan-unknown-version-%x", ver);
+		return;
+	}
+
+	if (ndo->ndo_vflag)
+		ND_PRINT(" II");
+
+	sid = (hdr & ERSPAN2_SID_MASK) >> ERSPAN2_SID_SHIFT;
+	ND_PRINT(" session %u", sid);
+
+	en = hdr & ERSPAN2_EN_MASK;
+	vlan = (hdr & ERSPAN2_VLAN_MASK) >> ERSPAN2_VLAN_SHIFT;
+	switch (en) {
+	case ERSPAN2_EN_NONE:
+		break;
+	case ERSPAN2_EN_ISL:
+		ND_PRINT(" isl %u", vlan);
+		break;
+	case ERSPAN2_EN_DOT1Q:
+		ND_PRINT(" vlan %u", vlan);
+		break;
+	case ERSPAN2_EN_VLAN:
+		ND_PRINT(" vlan payload");
+		break;
+	}
+
+	if (ndo->ndo_vflag) {
+		cos = (hdr & ERSPAN2_COS_MASK) >> ERSPAN2_COS_SHIFT;
+		ND_PRINT(" cos %u", cos);
+
+		if (hdr & ERSPAN2_T_MASK)
+			ND_PRINT(" truncated");
+	}
+
+	ND_ICHECK_U(len, <, 4);
+	hdr = GET_BE_U_4(bp);
+	bp += 4;
+	len -= 4;
+
+	if (ndo->ndo_vflag) {
+		index = (hdr & ERSPAN2_INDEX_MASK) >> ERSPAN2_INDEX_SHIFT;
+		ND_PRINT(" index %u", index);
+	}
+
+	ND_PRINT(": ");
+	ether_print(ndo, bp, len, ND_BYTES_AVAILABLE_AFTER(bp), NULL, NULL);
+	return;
+
+invalid:
+	nd_print_invalid(ndo);
+}

print-gre.c

@@ -86,7 +86,9 @@ static const struct tok gre_flag_values[] = {
  */
 #define GRE_CDP			0x2000	/* Cisco Discovery Protocol */
 #define GRE_NHRP		0x2001	/* Next Hop Resolution Protocol */
+#define GRE_ERSPAN_III		0x22eb
 #define GRE_WCCP		0x883e	/* Web Cache C* Protocol */
+#define GRE_ERSPAN_I_II		0x88be
 
 struct wccp_redirect {
 	nd_uint8_t	flags;
@@ -308,6 +310,9 @@ gre_print_0(netdissect_options *ndo, const u_char *bp, u_int length)
 	case ETHERTYPE_NSH:
 		nsh_print(ndo, bp, len);
 		break;
+	case GRE_ERSPAN_I_II:
+		erspan_print(ndo, flags, bp, len);
+		break;
 	case GRE_CDP:
 		cdp_print(ndo, bp, len);
 		break;