print-gre.c - platform/external/tcpdump - Git at Google

 /*	$OpenBSD: print-gre.c,v 1.6 2002/10/30 03:04:04 fgsch Exp $	*/

 /*
  * Copyright (c) 2002 Jason L. Wright (jason@thought.net)
  * 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.
  * 3. All advertising materials mentioning features or use of this software
  *    must display the following acknowledgement:
  *	This product includes software developed by Jason L. Wright
  * 4. The name of the author may not be used to endorse or promote products
  *    derived from this software without specific prior written permission.
  *
  * 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.
  */

 /*
  * tcpdump filter for GRE - Generic Routing Encapsulation
  * RFC1701 (GRE), RFC1702 (GRE IPv4), and RFC2637 (Enhanced GRE)
  */

 #ifndef lint
 static const char rcsid[] _U_ =
     "@(#) $Header: /tcpdump/master/tcpdump/print-gre.c,v 1.28 2005/04/06 21:32:39 mcr Exp $ (LBL)";
 #endif

 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif

 #include <tcpdump-stdinc.h>

 #include <stdio.h>
 #include <string.h>

 #include "interface.h"
 #include "addrtoname.h"
 #include "extract.h"

 #include "ip.h"
 #include "ethertype.h"

 #define	GRE_CP		0x8000		/* checksum present */
 #define	GRE_RP		0x4000		/* routing present */
 #define	GRE_KP		0x2000		/* key present */
 #define	GRE_SP		0x1000		/* sequence# present */
 #define	GRE_sP		0x0800		/* source routing */
 #define	GRE_RECRS	0x0700		/* recursion count */
 #define	GRE_AP		0x0080		/* acknowledgment# present */

 struct tok gre_flag_values[] = {
     { GRE_CP, "checksum present"},
     { GRE_RP, "routing present"},
     { GRE_KP, "key present"},
     { GRE_SP, "sequence# present"},
     { GRE_sP, "source routing present"},
     { GRE_RECRS, "recursion count"},
     { GRE_AP, "ack present"},
     { 0, NULL }
 };

 #define	GRE_VERS_MASK	0x0007		/* protocol version */

 /* source route entry types */
 #define	GRESRE_IP	0x0800		/* IP */
 #define	GRESRE_ASN	0xfffe		/* ASN */

 void gre_print_0(const u_char *, u_int);
 void gre_print_1(const u_char *, u_int);
 void gre_sre_print(u_int16_t, u_int8_t, u_int8_t, const u_char *, u_int);
 void gre_sre_ip_print(u_int8_t, u_int8_t, const u_char *, u_int);
 void gre_sre_asn_print(u_int8_t, u_int8_t, const u_char *, u_int);

 void
 gre_print(const u_char *bp, u_int length)
 {
 	u_int len = length, vers;

 	if (len < 2) {
 		printf("[|gre]");
 		return;
 	}
 	vers = EXTRACT_16BITS(bp) & GRE_VERS_MASK;
         printf("GREv%u",vers);

         switch(vers) {
         case 0:
             gre_print_0(bp, len);
             break;
         case 1:
             gre_print_1(bp, len);
             break;
 	default:
             printf(" ERROR: unknown-version");
             break;
         }
 	return;

 }

 void
 gre_print_0(const u_char *bp, u_int length)
 {
 	u_int len = length;
 	u_int16_t flags, prot;

 	flags = EXTRACT_16BITS(bp);
         if (vflag)
             printf(", Flags [%s]",
                    bittok2str(gre_flag_values,"none",flags));

 	len -= 2;
 	bp += 2;

 	if (len < 2)
 		goto trunc;
 	prot = EXTRACT_16BITS(bp);
 	len -= 2;
 	bp += 2;

 	if ((flags & GRE_CP) | (flags & GRE_RP)) {
 		if (len < 2)
 			goto trunc;
 		if (vflag)
 			printf(", sum 0x%x", EXTRACT_16BITS(bp));
 		bp += 2;
 		len -= 2;

 		if (len < 2)
 			goto trunc;
 		printf(", off 0x%x", EXTRACT_16BITS(bp));
 		bp += 2;
 		len -= 2;
 	}

 	if (flags & GRE_KP) {
 		if (len < 4)
 			goto trunc;
 		printf(", key=0x%x", EXTRACT_32BITS(bp));
 		bp += 4;
 		len -= 4;
 	}

 	if (flags & GRE_SP) {
 		if (len < 4)
 			goto trunc;
 		printf(", seq %u", EXTRACT_32BITS(bp));
 		bp += 4;
 		len -= 4;
 	}

 	if (flags & GRE_RP) {
 		for (;;) {
 			u_int16_t af;
 			u_int8_t sreoff;
 			u_int8_t srelen;

 			if (len < 4)
 				goto trunc;
 			af = EXTRACT_16BITS(bp);
 			sreoff = *(bp + 2);
 			srelen = *(bp + 3);
 			bp += 4;
 			len -= 4;

 			if (af == 0 && srelen == 0)
 				break;

 			gre_sre_print(af, sreoff, srelen, bp, len);

 			if (len < srelen)
 				goto trunc;
 			bp += srelen;
 			len -= srelen;
 		}
 	}

         if (eflag)
             printf(", proto %s (0x%04x)",
                    tok2str(ethertype_values,"unknown",prot),
                    prot);

         printf(", length %u",length);

         if (vflag < 1)
             printf(": "); /* put in a colon as protocol demarc */
         else
             printf("\n\t"); /* if verbose go multiline */

 	switch (prot) {
 	case ETHERTYPE_IP:
 	        ip_print(gndo, bp, len);
 		break;
 #ifdef INET6
 	case ETHERTYPE_IPV6:
 		ip6_print(bp, len);
 		break;
 #endif
 	case ETHERTYPE_MPLS:
 		mpls_print(bp, len);
 		break;
 	case ETHERTYPE_IPX:
 		ipx_print(bp, len);
 		break;
 	case ETHERTYPE_ATALK:
 		atalk_print(bp, len);
 		break;
 	case ETHERTYPE_GRE_ISO:
 		isoclns_print(bp, len, len);
 		break;
 	default:
 		printf("gre-proto-0x%x", prot);
 	}
 	return;

 trunc:
 	printf("[|gre]");
 }

 void
 gre_print_1(const u_char *bp, u_int length)
 {
 	u_int len = length;
 	u_int16_t flags, prot;

 	flags = EXTRACT_16BITS(bp);
 	len -= 2;
 	bp += 2;

 	if (vflag)
             printf(", Flags [%s]",
                    bittok2str(gre_flag_values,"none",flags));

 	if (len < 2)
 		goto trunc;
 	prot = EXTRACT_16BITS(bp);
 	len -= 2;
 	bp += 2;


 	if (flags & GRE_KP) {
 		u_int32_t k;

 		if (len < 4)
 			goto trunc;
 		k = EXTRACT_32BITS(bp);
 		printf(", call %d", k & 0xffff);
 		len -= 4;
 		bp += 4;
 	}

 	if (flags & GRE_SP) {
 		if (len < 4)
 			goto trunc;
 		printf(", seq %u", EXTRACT_32BITS(bp));
 		bp += 4;
 		len -= 4;
 	}

 	if (flags & GRE_AP) {
 		if (len < 4)
 			goto trunc;
 		printf(", ack %u", EXTRACT_32BITS(bp));
 		bp += 4;
 		len -= 4;
 	}

 	if ((flags & GRE_SP) == 0)
 		printf(", no-payload");

         if (eflag)
             printf(", proto %s (0x%04x)",
                    tok2str(ethertype_values,"unknown",prot),
                    prot);

         printf(", length %u",length);

         if ((flags & GRE_SP) == 0)
             return;

         if (vflag < 1)
             printf(": "); /* put in a colon as protocol demarc */
         else
             printf("\n\t"); /* if verbose go multiline */

 	switch (prot) {
 	case ETHERTYPE_PPP:
                 ppp_print(bp, len);
 		break;
 	default:
 		printf("gre-proto-0x%x", prot);
 		break;
 	}
 	return;

 trunc:
 	printf("[|gre]");
 }

 void
 gre_sre_print(u_int16_t af, u_int8_t sreoff, u_int8_t srelen,
     const u_char *bp, u_int len)
 {
 	switch (af) {
 	case GRESRE_IP:
 		printf(", (rtaf=ip");
 		gre_sre_ip_print(sreoff, srelen, bp, len);
 		printf(") ");
 		break;
 	case GRESRE_ASN:
 		printf(", (rtaf=asn");
 		gre_sre_asn_print(sreoff, srelen, bp, len);
 		printf(") ");
 		break;
 	default:
 		printf(", (rtaf=0x%x) ", af);
 	}
 }
 void
 gre_sre_ip_print(u_int8_t sreoff, u_int8_t srelen, const u_char *bp, u_int len)
 {
 	struct in_addr a;
 	const u_char *up = bp;

 	if (sreoff & 3) {
 		printf(", badoffset=%u", sreoff);
 		return;
 	}
 	if (srelen & 3) {
 		printf(", badlength=%u", srelen);
 		return;
 	}
 	if (sreoff >= srelen) {
 		printf(", badoff/len=%u/%u", sreoff, srelen);
 		return;
 	}

 	for (;;) {
 		if (len < 4 || srelen == 0)
 			return;

 		memcpy(&a, bp, sizeof(a));
 		printf(" %s%s",
 		    ((bp - up) == sreoff) ? "*" : "",
 		    inet_ntoa(a));

 		bp += 4;
 		len -= 4;
 		srelen -= 4;
 	}
 }

 void
 gre_sre_asn_print(u_int8_t sreoff, u_int8_t srelen, const u_char *bp, u_int len)
 {
 	const u_char *up = bp;

 	if (sreoff & 1) {
 		printf(", badoffset=%u", sreoff);
 		return;
 	}
 	if (srelen & 1) {
 		printf(", badlength=%u", srelen);
 		return;
 	}
 	if (sreoff >= srelen) {
 		printf(", badoff/len=%u/%u", sreoff, srelen);
 		return;
 	}

 	for (;;) {
 		if (len < 2 || srelen == 0)
 			return;

 		printf(" %s%x",
 		    ((bp - up) == sreoff) ? "*" : "",
 		    EXTRACT_16BITS(bp));

 		bp += 2;
 		len -= 2;
 		srelen -= 2;
 	}
 }
	/* $OpenBSD: print-gre.c,v 1.6 2002/10/30 03:04:04 fgsch Exp $ */

	/*
	* Copyright (c) 2002 Jason L. Wright (jason@thought.net)
	* 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.
	* 3. All advertising materials mentioning features or use of this software
	* must display the following acknowledgement:
	* This product includes software developed by Jason L. Wright
	* 4. The name of the author may not be used to endorse or promote products
	* derived from this software without specific prior written permission.
	*
	* 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.
	*/

	/*
	* tcpdump filter for GRE - Generic Routing Encapsulation
	* RFC1701 (GRE), RFC1702 (GRE IPv4), and RFC2637 (Enhanced GRE)
	*/

	#ifndef lint
	static const char rcsid[] _U_ =
	"@(#) $Header: /tcpdump/master/tcpdump/print-gre.c,v 1.28 2005/04/06 21:32:39 mcr Exp $ (LBL)";
	#endif

	#ifdef HAVE_CONFIG_H
	#include "config.h"
	#endif

	#include <tcpdump-stdinc.h>

	#include <stdio.h>
	#include <string.h>

	#include "interface.h"
	#include "addrtoname.h"
	#include "extract.h"

	#include "ip.h"
	#include "ethertype.h"

	#define GRE_CP 0x8000 /* checksum present */
	#define GRE_RP 0x4000 /* routing present */
	#define GRE_KP 0x2000 /* key present */
	#define GRE_SP 0x1000 /* sequence# present */
	#define GRE_sP 0x0800 /* source routing */
	#define GRE_RECRS 0x0700 /* recursion count */
	#define GRE_AP 0x0080 /* acknowledgment# present */

	struct tok gre_flag_values[] = {
	{ GRE_CP, "checksum present"},
	{ GRE_RP, "routing present"},
	{ GRE_KP, "key present"},
	{ GRE_SP, "sequence# present"},
	{ GRE_sP, "source routing present"},
	{ GRE_RECRS, "recursion count"},
	{ GRE_AP, "ack present"},
	{ 0, NULL }
	};

	#define GRE_VERS_MASK 0x0007 /* protocol version */

	/* source route entry types */
	#define GRESRE_IP 0x0800 /* IP */
	#define GRESRE_ASN 0xfffe /* ASN */

	void gre_print_0(const u_char *, u_int);
	void gre_print_1(const u_char *, u_int);
	void gre_sre_print(u_int16_t, u_int8_t, u_int8_t, const u_char *, u_int);
	void gre_sre_ip_print(u_int8_t, u_int8_t, const u_char *, u_int);
	void gre_sre_asn_print(u_int8_t, u_int8_t, const u_char *, u_int);

	void
	gre_print(const u_char *bp, u_int length)
	{
	u_int len = length, vers;

	if (len < 2) {
	printf("[\|gre]");
	return;
	}
	vers = EXTRACT_16BITS(bp) & GRE_VERS_MASK;
	printf("GREv%u",vers);

	switch(vers) {
	case 0:
	gre_print_0(bp, len);
	break;
	case 1:
	gre_print_1(bp, len);
	break;
	default:
	printf(" ERROR: unknown-version");
	break;
	}
	return;

	}

	void
	gre_print_0(const u_char *bp, u_int length)
	{
	u_int len = length;
	u_int16_t flags, prot;

	flags = EXTRACT_16BITS(bp);
	if (vflag)
	printf(", Flags [%s]",
	bittok2str(gre_flag_values,"none",flags));

	len -= 2;
	bp += 2;

	if (len < 2)
	goto trunc;
	prot = EXTRACT_16BITS(bp);
	len -= 2;
	bp += 2;

	if ((flags & GRE_CP) \| (flags & GRE_RP)) {
	if (len < 2)
	goto trunc;
	if (vflag)
	printf(", sum 0x%x", EXTRACT_16BITS(bp));
	bp += 2;
	len -= 2;

	if (len < 2)
	goto trunc;
	printf(", off 0x%x", EXTRACT_16BITS(bp));
	bp += 2;
	len -= 2;
	}

	if (flags & GRE_KP) {
	if (len < 4)
	goto trunc;
	printf(", key=0x%x", EXTRACT_32BITS(bp));
	bp += 4;
	len -= 4;
	}

	if (flags & GRE_SP) {
	if (len < 4)
	goto trunc;
	printf(", seq %u", EXTRACT_32BITS(bp));
	bp += 4;
	len -= 4;
	}

	if (flags & GRE_RP) {
	for (;;) {
	u_int16_t af;
	u_int8_t sreoff;
	u_int8_t srelen;

	if (len < 4)
	goto trunc;
	af = EXTRACT_16BITS(bp);
	sreoff = *(bp + 2);
	srelen = *(bp + 3);
	bp += 4;
	len -= 4;

	if (af == 0 && srelen == 0)
	break;

	gre_sre_print(af, sreoff, srelen, bp, len);

	if (len < srelen)
	goto trunc;
	bp += srelen;
	len -= srelen;
	}
	}

	if (eflag)
	printf(", proto %s (0x%04x)",
	tok2str(ethertype_values,"unknown",prot),
	prot);

	printf(", length %u",length);

	if (vflag < 1)
	printf(": "); /* put in a colon as protocol demarc */
	else
	printf("\n\t"); /* if verbose go multiline */

	switch (prot) {
	case ETHERTYPE_IP:
	ip_print(gndo, bp, len);
	break;
	#ifdef INET6
	case ETHERTYPE_IPV6:
	ip6_print(bp, len);
	break;
	#endif
	case ETHERTYPE_MPLS:
	mpls_print(bp, len);
	break;
	case ETHERTYPE_IPX:
	ipx_print(bp, len);
	break;
	case ETHERTYPE_ATALK:
	atalk_print(bp, len);
	break;
	case ETHERTYPE_GRE_ISO:
	isoclns_print(bp, len, len);
	break;
	default:
	printf("gre-proto-0x%x", prot);
	}
	return;

	trunc:
	printf("[\|gre]");
	}

	void
	gre_print_1(const u_char *bp, u_int length)
	{
	u_int len = length;
	u_int16_t flags, prot;

	flags = EXTRACT_16BITS(bp);
	len -= 2;
	bp += 2;

	if (vflag)
	printf(", Flags [%s]",
	bittok2str(gre_flag_values,"none",flags));

	if (len < 2)
	goto trunc;
	prot = EXTRACT_16BITS(bp);
	len -= 2;
	bp += 2;


	if (flags & GRE_KP) {
	u_int32_t k;

	if (len < 4)
	goto trunc;
	k = EXTRACT_32BITS(bp);
	printf(", call %d", k & 0xffff);
	len -= 4;
	bp += 4;
	}

	if (flags & GRE_SP) {
	if (len < 4)
	goto trunc;
	printf(", seq %u", EXTRACT_32BITS(bp));
	bp += 4;
	len -= 4;
	}

	if (flags & GRE_AP) {
	if (len < 4)
	goto trunc;
	printf(", ack %u", EXTRACT_32BITS(bp));
	bp += 4;
	len -= 4;
	}

	if ((flags & GRE_SP) == 0)
	printf(", no-payload");

	if (eflag)
	printf(", proto %s (0x%04x)",
	tok2str(ethertype_values,"unknown",prot),
	prot);

	printf(", length %u",length);

	if ((flags & GRE_SP) == 0)
	return;

	if (vflag < 1)
	printf(": "); /* put in a colon as protocol demarc */
	else
	printf("\n\t"); /* if verbose go multiline */

	switch (prot) {
	case ETHERTYPE_PPP:
	ppp_print(bp, len);
	break;
	default:
	printf("gre-proto-0x%x", prot);
	break;
	}
	return;

	trunc:
	printf("[\|gre]");
	}

	void
	gre_sre_print(u_int16_t af, u_int8_t sreoff, u_int8_t srelen,
	const u_char *bp, u_int len)
	{
	switch (af) {
	case GRESRE_IP:
	printf(", (rtaf=ip");
	gre_sre_ip_print(sreoff, srelen, bp, len);
	printf(") ");
	break;
	case GRESRE_ASN:
	printf(", (rtaf=asn");
	gre_sre_asn_print(sreoff, srelen, bp, len);
	printf(") ");
	break;
	default:
	printf(", (rtaf=0x%x) ", af);
	}
	}
	void
	gre_sre_ip_print(u_int8_t sreoff, u_int8_t srelen, const u_char *bp, u_int len)
	{
	struct in_addr a;
	const u_char *up = bp;

	if (sreoff & 3) {
	printf(", badoffset=%u", sreoff);
	return;
	}
	if (srelen & 3) {
	printf(", badlength=%u", srelen);
	return;
	}
	if (sreoff >= srelen) {
	printf(", badoff/len=%u/%u", sreoff, srelen);
	return;
	}

	for (;;) {
	if (len < 4 \|\| srelen == 0)
	return;

	memcpy(&a, bp, sizeof(a));
	printf(" %s%s",
	((bp - up) == sreoff) ? "*" : "",
	inet_ntoa(a));

	bp += 4;
	len -= 4;
	srelen -= 4;
	}
	}

	void
	gre_sre_asn_print(u_int8_t sreoff, u_int8_t srelen, const u_char *bp, u_int len)
	{
	const u_char *up = bp;

	if (sreoff & 1) {
	printf(", badoffset=%u", sreoff);
	return;
	}
	if (srelen & 1) {
	printf(", badlength=%u", srelen);
	return;
	}
	if (sreoff >= srelen) {
	printf(", badoff/len=%u/%u", sreoff, srelen);
	return;
	}

	for (;;) {
	if (len < 2 \|\| srelen == 0)
	return;

	printf(" %s%x",
	((bp - up) == sreoff) ? "*" : "",
	EXTRACT_16BITS(bp));

	bp += 2;
	len -= 2;
	srelen -= 2;
	}
	}