tcpdump/print-igmp.c
guy fcc82f451d The "__attribute__((packed))" tag on structures causes some files not to
compile with Sun C, as "interface.h" isn't being included before the
structures are being declared.

Furthermore, in the files that Sun C *can* compile, it doesn't cause Sun
C to generate code that's safe with unaligned accesses, as
"__attribute__" is defined as a do-nothing macro with compilers that
don't support it.

Therefore, we get rid of that tag on the structures to which it was
added, and instead use "EXTRACT_16BIT()" and "EXTRACT_32BIT()" to fetch
16-bit and 32-bit big-endian quantities from packets.  We also fix some
other references to multi-byte quantities to get rid of code that tries
to do unaligned loads on platforms that don't support them.

We also throw in a hack that makes those macros use
"__attribute__((packed))" on structures containing only one 16-bit or
32-bit integer to get the compiler to generate unaligned-safe code
rather than doing it by hand.  (GCC on SPARC produces the same code that
doing it by hand does; I don't know if GCC on any other big-endian
strict-alignment processor generates better code for that case.  On
little-endian processors, as "ntohs()" and "ntohl()" might be functions,
that might actually produce worse code.)

Fix some places to use "%u" rather than "%d" to print unsigned
quantities.
2002-12-11 07:13:49 +00:00

331 lines
9.3 KiB
C

/*
* 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.
*/
#ifndef lint
static const char rcsid[] =
"@(#) $Header: /tcpdump/master/tcpdump/print-igmp.c,v 1.11 2002-12-11 07:14:02 guy 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" /* must come after interface.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 {
u_int32_t tr_src; /* traceroute source */
u_int32_t tr_dst; /* traceroute destination */
u_int32_t tr_raddr; /* traceroute response address */
u_int32_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 {
u_int32_t tr_qarr; /* query arrival time */
u_int32_t tr_inaddr; /* incoming interface address */
u_int32_t tr_outaddr; /* outgoing interface address */
u_int32_t tr_rmtaddr; /* parent address in source tree */
u_int32_t tr_vifin; /* input packet count on interface */
u_int32_t tr_vifout; /* output packet count on interface */
u_int32_t tr_pktcnt; /* total incoming packets for src-grp */
u_int8_t tr_rproto; /* routing proto deployed on router */
u_int8_t tr_fttl; /* ttl required to forward on outvif */
u_int8_t tr_smask; /* subnet mask for src addr */
u_int8_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 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(register const u_char *bp, register u_int len)
{
register const struct tr_query *tr = (const struct tr_query *)(bp + 8);
TCHECK(*tr);
if (len < 8 + sizeof (struct tr_query)) {
(void)printf(" [invalid len %d]", len);
return;
}
printf("mtrace %u: %s to %s reply-to %s",
TR_GETQID(EXTRACT_32BITS(&tr->tr_rttlqid)),
ipaddr_string(&tr->tr_src), ipaddr_string(&tr->tr_dst),
ipaddr_string(&tr->tr_raddr));
if (IN_CLASSD(EXTRACT_32BITS(&tr->tr_raddr)))
printf(" with-ttl %d", TR_GETTTL(EXTRACT_32BITS(&tr->tr_rttlqid)));
return;
trunc:
(void)printf("[|igmp]");
return;
}
static void
print_mresp(register const u_char *bp, register u_int len)
{
register const struct tr_query *tr = (const struct tr_query *)(bp + 8);
TCHECK(*tr);
if (len < 8 + sizeof (struct tr_query)) {
(void)printf(" [invalid len %d]", len);
return;
}
printf("mresp %lu: %s to %s reply-to %s",
(u_long)TR_GETQID(EXTRACT_32BITS(&tr->tr_rttlqid)),
ipaddr_string(&tr->tr_src), ipaddr_string(&tr->tr_dst),
ipaddr_string(&tr->tr_raddr));
if (IN_CLASSD(EXTRACT_32BITS(&tr->tr_raddr)))
printf(" with-ttl %d", TR_GETTTL(EXTRACT_32BITS(&tr->tr_rttlqid)));
return;
trunc:
(void)printf("[|igmp]");
return;
}
static void
print_igmpv3_report(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) {
(void)printf(" [invalid len %d]", len);
return;
}
TCHECK2(bp[6], 2);
ngroups = EXTRACT_16BITS(&bp[6]);
(void)printf(", %d group record(s)", ngroups);
if (vflag > 0) {
/* Print the group records */
group = 8;
for (i=0; i<ngroups; i++) {
if (len < group+8) {
(void)printf(" [invalid number of groups]");
return;
}
TCHECK2(bp[group+4], 4);
(void)printf(" [gaddr %s", ipaddr_string(&bp[group+4]));
(void)printf(" %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)) {
(void)printf(" [invalid number of sources %d]", nsrcs);
return;
}
if (vflag == 1)
(void)printf(", %d source(s)", nsrcs);
else {
/* Print the sources */
(void)printf(" {");
for (j=0; j<nsrcs; j++) {
TCHECK2(bp[group+8+(j<<2)], 4);
(void)printf(" %s", ipaddr_string(&bp[group+8+(j<<2)]));
}
(void)printf(" }");
}
/* Next group record */
group += 8 + (nsrcs << 2);
(void)printf("]");
}
}
return;
trunc:
(void)printf("[|igmp]");
return;
}
static void
print_igmpv3_query(register const u_char *bp, register u_int len)
{
u_int mrc;
int mrt;
u_int nsrcs;
register u_int i;
(void)printf(" v3");
/* Minimum len is 12, and should be a multiple of 4 */
if (len < 12 || len & 0x03) {
(void)printf(" [invalid len %d]", len);
return;
}
mrc = bp[1];
if (mrc < 128) {
mrt = mrc;
} else {
mrt = ((mrc & 0x0f) | 0x10) << (((mrc & 0x70) >> 4) + 3);
}
if (mrc != 100) {
(void)printf(" [max resp time ");
relts_print(mrt);
(void)printf("]");
}
TCHECK2(bp[4], 4);
if (EXTRACT_32BITS(&bp[4]) == 0)
return;
(void)printf(" [gaddr %s", ipaddr_string(&bp[4]));
TCHECK2(bp[10], 2);
nsrcs = EXTRACT_16BITS(&bp[10]);
if (nsrcs > 0) {
if (len < 12 + (nsrcs << 2))
(void)printf(" [invalid number of sources]");
else if (vflag > 1) {
(void)printf(" {");
for (i=0; i<nsrcs; i++) {
TCHECK2(bp[12+(i<<2)], 4);
(void)printf(" %s", ipaddr_string(&bp[12+(i<<2)]));
}
(void)printf(" }");
} else
(void)printf(", %d source(s)", nsrcs);
}
(void)printf("]");
return;
trunc:
(void)printf("[|igmp]");
return;
}
void
igmp_print(register const u_char *bp, register u_int len)
{
if (qflag) {
(void)printf("igmp");
return;
}
TCHECK2(bp[0], 8);
switch (bp[0]) {
case 0x11:
(void)printf("igmp query");
if (len >= 12)
print_igmpv3_query(bp, len);
else {
if (bp[1]) {
(void)printf(" v2");
if (bp[1] != 100)
(void)printf(" [max resp time %d]", bp[1]);
} else
(void)printf(" v1");
if (EXTRACT_32BITS(&bp[4]))
(void)printf(" [gaddr %s]", ipaddr_string(&bp[4]));
if (len != 8)
(void)printf(" [len %d]", len);
}
break;
case 0x12:
(void)printf("igmp v1 report %s", ipaddr_string(&bp[4]));
if (len != 8)
(void)printf(" [len %d]", len);
break;
case 0x16:
(void)printf("igmp v2 report %s", ipaddr_string(&bp[4]));
break;
case 0x22:
(void)printf("igmp v3 report");
print_igmpv3_report(bp, len);
break;
case 0x17:
(void)printf("igmp leave %s", ipaddr_string(&bp[4]));
break;
case 0x13:
(void)printf("igmp dvmrp");
if (len < 8)
(void)printf(" [len %d]", len);
else
dvmrp_print(bp, len);
break;
case 0x14:
(void)printf("igmp pimv1");
pimv1_print(bp, len);
break;
case 0x1e:
print_mresp(bp, len);
break;
case 0x1f:
print_mtrace(bp, len);
break;
default:
(void)printf("igmp-%d", bp[0]);
break;
}
if (vflag && TTEST2(bp[0], len)) {
/* Check the IGMP checksum */
if (in_cksum((const u_short*)bp, len, 0))
printf(" bad igmp cksum %x!", EXTRACT_16BITS(&bp[2]));
}
return;
trunc:
fputs("[|igmp]", stdout);
}