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63c8c04ea7
tcpdump/print-igmp.c
Francois-Xavier Le Bail beca6e7025 IGMP: Add a length check
2017-01-18 09:16:39 +01:00

342 lines
10 KiB
C
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/*
* Copyright (c) 1988, 1989, 1990, 1991, 1993, 1994, 1995, 1996
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that: (1) source code distributions
* retain the above copyright notice and this paragraph in its entirety, (2)
* distributions including binary code include the above copyright notice and
* this paragraph in its entirety in the documentation or other materials
* provided with the distribution, and (3) all advertising materials mentioning
* features or use of this software display the following acknowledgement:
* ``This product includes software developed by the University of California,
* Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
* the University nor the names of its contributors may be used to endorse
* or promote products derived from this software without specific prior
* written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
/* \summary: Internet Group Management Protocol (IGMP) printer */
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <netdissect-stdinc.h>
#include "netdissect.h"
#include "addrtoname.h"
#include "extract.h"
#ifndef IN_CLASSD
#define IN_CLASSD(i) (((int32_t)(i) & 0xf0000000) == 0xe0000000)
#endif
static const char tstr[] = "[|igmp]";
/* (following from ipmulti/mrouted/prune.h) */
/*
* The packet format for a traceroute request.
*/
struct tr_query {
uint32_t tr_src; /* traceroute source */
uint32_t tr_dst; /* traceroute destination */
uint32_t tr_raddr; /* traceroute response address */
uint32_t tr_rttlqid; /* response ttl and qid */
};
#define TR_GETTTL(x) (int)(((x) >> 24) & 0xff)
#define TR_GETQID(x) ((x) & 0x00ffffff)
/*
* Traceroute response format. A traceroute response has a tr_query at the
* beginning, followed by one tr_resp for each hop taken.
*/
struct tr_resp {
uint32_t tr_qarr; /* query arrival time */
uint32_t tr_inaddr; /* incoming interface address */
uint32_t tr_outaddr; /* outgoing interface address */
uint32_t tr_rmtaddr; /* parent address in source tree */
uint32_t tr_vifin; /* input packet count on interface */
uint32_t tr_vifout; /* output packet count on interface */
uint32_t tr_pktcnt; /* total incoming packets for src-grp */
uint8_t tr_rproto; /* routing proto deployed on router */
uint8_t tr_fttl; /* ttl required to forward on outvif */
uint8_t tr_smask; /* subnet mask for src addr */
uint8_t tr_rflags; /* forwarding error codes */
};
/* defs within mtrace */
#define TR_QUERY 1
#define TR_RESP 2
/* fields for tr_rflags (forwarding error codes) */
#define TR_NO_ERR 0
#define TR_WRONG_IF 1
#define TR_PRUNED 2
#define TR_OPRUNED 3
#define TR_SCOPED 4
#define TR_NO_RTE 5
#define TR_NO_FWD 7
#define TR_NO_SPACE 0x81
#define TR_OLD_ROUTER 0x82
/* fields for tr_rproto (routing protocol) */
#define TR_PROTO_DVMRP 1
#define TR_PROTO_MOSPF 2
#define TR_PROTO_PIM 3
#define TR_PROTO_CBT 4
/* igmpv3 report types */
static const struct tok igmpv3report2str[] = {
{ 1, "is_in" },
{ 2, "is_ex" },
{ 3, "to_in" },
{ 4, "to_ex" },
{ 5, "allow" },
{ 6, "block" },
{ 0, NULL }
};
static void
print_mtrace(netdissect_options *ndo,
register const u_char *bp, register u_int len)
{
register const struct tr_query *tr = (const struct tr_query *)(bp + 8);
ND_TCHECK(*tr);
if (len < 8 + sizeof (struct tr_query)) {
ND_PRINT((ndo, " [invalid len %d]", len));
return;
}
ND_PRINT((ndo, "mtrace %u: %s to %s reply-to %s",
TR_GETQID(EXTRACT_32BITS(&tr->tr_rttlqid)),
ipaddr_string(ndo, &tr->tr_src), ipaddr_string(ndo, &tr->tr_dst),
ipaddr_string(ndo, &tr->tr_raddr)));
if (IN_CLASSD(EXTRACT_32BITS(&tr->tr_raddr)))
ND_PRINT((ndo, " with-ttl %d", TR_GETTTL(EXTRACT_32BITS(&tr->tr_rttlqid))));
return;
trunc:
ND_PRINT((ndo, "%s", tstr));
}
static void
print_mresp(netdissect_options *ndo,
register const u_char *bp, register u_int len)
{
register const struct tr_query *tr = (const struct tr_query *)(bp + 8);
ND_TCHECK(*tr);
if (len < 8 + sizeof (struct tr_query)) {
ND_PRINT((ndo, " [invalid len %d]", len));
return;
}
ND_PRINT((ndo, "mresp %lu: %s to %s reply-to %s",
(u_long)TR_GETQID(EXTRACT_32BITS(&tr->tr_rttlqid)),
ipaddr_string(ndo, &tr->tr_src), ipaddr_string(ndo, &tr->tr_dst),
ipaddr_string(ndo, &tr->tr_raddr)));
if (IN_CLASSD(EXTRACT_32BITS(&tr->tr_raddr)))
ND_PRINT((ndo, " with-ttl %d", TR_GETTTL(EXTRACT_32BITS(&tr->tr_rttlqid))));
return;
trunc:
ND_PRINT((ndo, "%s", tstr));
}
static void
print_igmpv3_report(netdissect_options *ndo,
register const u_char *bp, register u_int len)
{
u_int group, nsrcs, ngroups;
register u_int i, j;
/* Minimum len is 16, and should be a multiple of 4 */
if (len < 16 || len & 0x03) {
ND_PRINT((ndo, " [invalid len %d]", len));
return;
}
ND_TCHECK2(bp[6], 2);
ngroups = EXTRACT_16BITS(&bp[6]);
ND_PRINT((ndo, ", %d group record(s)", ngroups));
if (ndo->ndo_vflag > 0) {
/* Print the group records */
group = 8;
for (i=0; i<ngroups; i++) {
if (len < group+8) {
ND_PRINT((ndo, " [invalid number of groups]"));
return;
}
ND_TCHECK2(bp[group+4], 4);
ND_PRINT((ndo, " [gaddr %s", ipaddr_string(ndo, &bp[group+4])));
ND_PRINT((ndo, " %s", tok2str(igmpv3report2str, " [v3-report-#%d]",
bp[group])));
nsrcs = EXTRACT_16BITS(&bp[group+2]);
/* Check the number of sources and print them */
if (len < group+8+(nsrcs<<2)) {
ND_PRINT((ndo, " [invalid number of sources %d]", nsrcs));
return;
}
if (ndo->ndo_vflag == 1)
ND_PRINT((ndo, ", %d source(s)", nsrcs));
else {
/* Print the sources */
ND_PRINT((ndo, " {"));
for (j=0; j<nsrcs; j++) {
ND_TCHECK2(bp[group+8+(j<<2)], 4);
ND_PRINT((ndo, " %s", ipaddr_string(ndo, &bp[group+8+(j<<2)])));
}
ND_PRINT((ndo, " }"));
}
/* Next group record */
group += 8 + (nsrcs << 2);
ND_PRINT((ndo, "]"));
}
}
return;
trunc:
ND_PRINT((ndo, "%s", tstr));
}
static void
print_igmpv3_query(netdissect_options *ndo,
register const u_char *bp, register u_int len)
{
u_int mrc;
u_int mrt;
u_int nsrcs;
register u_int i;
ND_PRINT((ndo, " v3"));
/* Minimum len is 12, and should be a multiple of 4 */
if (len < 12 || len & 0x03) {
ND_PRINT((ndo, " [invalid len %d]", len));
return;
}
ND_TCHECK(bp[1]);
mrc = bp[1];
if (mrc < 128) {
mrt = mrc;
} else {
mrt = ((mrc & 0x0f) | 0x10) << (((mrc & 0x70) >> 4) + 3);
}
if (mrc != 100) {
ND_PRINT((ndo, " [max resp time "));
if (mrt < 600) {
ND_PRINT((ndo, "%.1fs", mrt * 0.1));
} else {
unsigned_relts_print(ndo, mrt / 10);
}
ND_PRINT((ndo, "]"));
}
ND_TCHECK2(bp[4], 4);
if (EXTRACT_32BITS(&bp[4]) == 0)
return;
ND_PRINT((ndo, " [gaddr %s", ipaddr_string(ndo, &bp[4])));
ND_TCHECK2(bp[10], 2);
nsrcs = EXTRACT_16BITS(&bp[10]);
if (nsrcs > 0) {
if (len < 12 + (nsrcs << 2))
ND_PRINT((ndo, " [invalid number of sources]"));
else if (ndo->ndo_vflag > 1) {
ND_PRINT((ndo, " {"));
for (i=0; i<nsrcs; i++) {
ND_TCHECK2(bp[12+(i<<2)], 4);
ND_PRINT((ndo, " %s", ipaddr_string(ndo, &bp[12+(i<<2)])));
}
ND_PRINT((ndo, " }"));
} else
ND_PRINT((ndo, ", %d source(s)", nsrcs));
}
ND_PRINT((ndo, "]"));
return;
trunc:
ND_PRINT((ndo, "%s", tstr));
}
void
igmp_print(netdissect_options *ndo,
register const u_char *bp, register u_int len)
{
struct cksum_vec vec[1];
if (ndo->ndo_qflag) {
ND_PRINT((ndo, "igmp"));
return;
}
ND_TCHECK(bp[0]);
switch (bp[0]) {
case 0x11:
ND_PRINT((ndo, "igmp query"));
if (len >= 12)
print_igmpv3_query(ndo, bp, len);
else {
ND_TCHECK(bp[1]);
if (bp[1]) {
ND_PRINT((ndo, " v2"));
if (bp[1] != 100)
ND_PRINT((ndo, " [max resp time %d]", bp[1]));
} else
ND_PRINT((ndo, " v1"));
ND_TCHECK2(bp[4], 4);
if (EXTRACT_32BITS(&bp[4]))
ND_PRINT((ndo, " [gaddr %s]", ipaddr_string(ndo, &bp[4])));
if (len != 8)
ND_PRINT((ndo, " [len %d]", len));
}
break;
case 0x12:
ND_TCHECK2(bp[4], 4);
ND_PRINT((ndo, "igmp v1 report %s", ipaddr_string(ndo, &bp[4])));
if (len != 8)
ND_PRINT((ndo, " [len %d]", len));
break;
case 0x16:
ND_TCHECK2(bp[4], 4);
ND_PRINT((ndo, "igmp v2 report %s", ipaddr_string(ndo, &bp[4])));
break;
case 0x22:
ND_PRINT((ndo, "igmp v3 report"));
print_igmpv3_report(ndo, bp, len);
break;
case 0x17:
ND_TCHECK2(bp[4], 4);
ND_PRINT((ndo, "igmp leave %s", ipaddr_string(ndo, &bp[4])));
break;
case 0x13:
ND_PRINT((ndo, "igmp dvmrp"));
if (len < 8)
ND_PRINT((ndo, " [len %d]", len));
else
dvmrp_print(ndo, bp, len);
break;
case 0x14:
ND_PRINT((ndo, "igmp pimv1"));
pimv1_print(ndo, bp, len);
break;
case 0x1e:
print_mresp(ndo, bp, len);
break;
case 0x1f:
print_mtrace(ndo, bp, len);
break;
default:
ND_PRINT((ndo, "igmp-%d", bp[0]));
break;
}
if (ndo->ndo_vflag && len >= 4 && ND_TTEST2(bp[0], len)) {
/* Check the IGMP checksum */
vec[0].ptr = bp;
vec[0].len = len;
if (in_cksum(vec, 1))
ND_PRINT((ndo, " bad igmp cksum %x!", EXTRACT_16BITS(&bp[2])));
}
return;
trunc:
ND_PRINT((ndo, "%s", tstr));
}
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