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e3a00d340c
tcpdump/print-igmp.c
Denis Ovsienko 0a8c146f78 IGMP: Remove all remaining ND_TCHECK*() cases. 
In print_mtrace() the check was just before a GET that fetches the last
field of the structure. The other three checks tested exactly the space
from that GET_IPADDR_STRING() would fetch anyway.
2020-09-30 14:52:46 +01:00

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8.5 KiB
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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 */
/*
* specification:
*
* RFC 2236 for IGMPv2
* RFC 3376 for IGMPv3
* draft-asaeda-mboned-mtrace-v2 for the mtrace message
*/
#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
/* (following from ipmulti/mrouted/prune.h) */
/*
* The packet format for a traceroute request.
*/
struct tr_query {
nd_uint32_t tr_src; /* traceroute source */
nd_uint32_t tr_dst; /* traceroute destination */
nd_uint32_t tr_raddr; /* traceroute response address */
nd_uint8_t tr_rttl; /* response ttl */
nd_uint24_t tr_qid; /* qid */
};
/*
* 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 {
nd_uint32_t tr_qarr; /* query arrival time */
nd_uint32_t tr_inaddr; /* incoming interface address */
nd_uint32_t tr_outaddr; /* outgoing interface address */
nd_uint32_t tr_rmtaddr; /* parent address in source tree */
nd_uint32_t tr_vifin; /* input packet count on interface */
nd_uint32_t tr_vifout; /* output packet count on interface */
nd_uint32_t tr_pktcnt; /* total incoming packets for src-grp */
nd_uint8_t tr_rproto; /* routing proto deployed on router */
nd_uint8_t tr_fttl; /* ttl required to forward on outvif */
nd_uint8_t tr_smask; /* subnet mask for src addr */
nd_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,
const char *typename,
const u_char *bp, u_int len)
{
const struct tr_query *tr = (const struct tr_query *)(bp + 8);
if (len < 8 + sizeof (struct tr_query)) {
ND_PRINT(" [invalid len %u]", len);
return;
}
ND_PRINT("%s %u: %s to %s reply-to %s",
typename,
GET_BE_U_3(tr->tr_qid),
GET_IPADDR_STRING(tr->tr_src), GET_IPADDR_STRING(tr->tr_dst),
GET_IPADDR_STRING(tr->tr_raddr));
if (IN_CLASSD(GET_BE_U_4(tr->tr_raddr)))
ND_PRINT(" with-ttl %u", GET_U_1(tr->tr_rttl));
}
static void
print_igmpv3_report(netdissect_options *ndo,
const u_char *bp, u_int len)
{
u_int group, nsrcs, ngroups;
u_int i, j;
/* Minimum len is 16, and should be a multiple of 4 */
if (len < 16 || len & 0x03) {
ND_PRINT(" [invalid len %u]", len);
return;
}
ngroups = GET_BE_U_2(bp + 6);
ND_PRINT(", %u 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(" [invalid number of groups]");
return;
}
ND_PRINT(" [gaddr %s", GET_IPADDR_STRING(bp + group + 4));
ND_PRINT(" %s", tok2str(igmpv3report2str, " [v3-report-#%u]",
GET_U_1(bp + group)));
nsrcs = GET_BE_U_2(bp + group + 2);
/* Check the number of sources and print them */
if (len < group+8+(nsrcs<<2)) {
ND_PRINT(" [invalid number of sources %u]", nsrcs);
return;
}
if (ndo->ndo_vflag == 1)
ND_PRINT(", %u source(s)", nsrcs);
else {
/* Print the sources */
ND_PRINT(" {");
for (j=0; j<nsrcs; j++) {
ND_PRINT(" %s", GET_IPADDR_STRING(bp + group + 8 + (j << 2)));
}
ND_PRINT(" }");
}
/* Next group record */
group += 8 + (nsrcs << 2);
ND_PRINT("]");
}
}
}
static void
print_igmpv3_query(netdissect_options *ndo,
const u_char *bp, u_int len)
{
u_int mrc;
u_int mrt;
u_int nsrcs;
u_int i;
ND_PRINT(" v3");
/* Minimum len is 12, and should be a multiple of 4 */
if (len < 12 || len & 0x03) {
ND_PRINT(" [invalid len %u]", len);
return;
}
mrc = GET_U_1(bp + 1);
if (mrc < 128) {
mrt = mrc;
} else {
mrt = ((mrc & 0x0f) | 0x10) << (((mrc & 0x70) >> 4) + 3);
}
if (mrc != 100) {
ND_PRINT(" [max resp time ");
if (mrt < 600) {
ND_PRINT("%.1fs", mrt * 0.1);
} else {
unsigned_relts_print(ndo, mrt / 10);
}
ND_PRINT("]");
}
if (GET_BE_U_4(bp + 4) == 0)
return;
ND_PRINT(" [gaddr %s", GET_IPADDR_STRING(bp + 4));
nsrcs = GET_BE_U_2(bp + 10);
if (nsrcs > 0) {
if (len < 12 + (nsrcs << 2))
ND_PRINT(" [invalid number of sources]");
else if (ndo->ndo_vflag > 1) {
ND_PRINT(" {");
for (i=0; i<nsrcs; i++) {
ND_PRINT(" %s", GET_IPADDR_STRING(bp + 12 + (i << 2)));
}
ND_PRINT(" }");
} else
ND_PRINT(", %u source(s)", nsrcs);
}
ND_PRINT("]");
}
void
igmp_print(netdissect_options *ndo,
const u_char *bp, u_int len)
{
struct cksum_vec vec[1];
ndo->ndo_protocol = "igmp";
if (ndo->ndo_qflag) {
ND_PRINT("igmp");
return;
}
switch (GET_U_1(bp)) {
case 0x11:
ND_PRINT("igmp query");
if (len >= 12)
print_igmpv3_query(ndo, bp, len);
else {
if (GET_U_1(bp + 1)) {
ND_PRINT(" v2");
if (GET_U_1(bp + 1) != 100)
ND_PRINT(" [max resp time %u]", GET_U_1(bp + 1));
} else
ND_PRINT(" v1");
if (GET_BE_U_4(bp + 4))
ND_PRINT(" [gaddr %s]", GET_IPADDR_STRING(bp + 4));
if (len != 8)
ND_PRINT(" [len %u]", len);
}
break;
case 0x12:
ND_PRINT("igmp v1 report %s", GET_IPADDR_STRING(bp + 4));
if (len != 8)
ND_PRINT(" [len %u]", len);
break;
case 0x16:
ND_PRINT("igmp v2 report %s", GET_IPADDR_STRING(bp + 4));
break;
case 0x22:
ND_PRINT("igmp v3 report");
print_igmpv3_report(ndo, bp, len);
break;
case 0x17:
ND_PRINT("igmp leave %s", GET_IPADDR_STRING(bp + 4));
break;
case 0x13:
ND_PRINT("igmp dvmrp");
if (len < 8)
ND_PRINT(" [len %u]", len);
else
dvmrp_print(ndo, bp, len);
break;
case 0x14:
ND_PRINT("igmp pimv1");
pimv1_print(ndo, bp, len);
break;
case 0x1e:
print_mtrace(ndo, "mresp", bp, len);
break;
case 0x1f:
print_mtrace(ndo, "mtrace", bp, len);
break;
default:
ND_PRINT("igmp-%u", GET_U_1(bp));
break;
}
if (ndo->ndo_vflag && len >= 4 && ND_TTEST_LEN(bp, len)) {
/* Check the IGMP checksum */
vec[0].ptr = bp;
vec[0].len = len;
if (in_cksum(vec, 1))
ND_PRINT(" bad igmp cksum %x!", GET_BE_U_2(bp + 2));
}
}
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