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print-igmp.c revision 1.5
      1 /*
      2  * Copyright (c) 1988, 1989, 1990, 1991, 1993, 1994, 1995, 1996
      3  *  The Regents of the University of California.  All rights reserved.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that: (1) source code distributions
      7  * retain the above copyright notice and this paragraph in its entirety, (2)
      8  * distributions including binary code include the above copyright notice and
      9  * this paragraph in its entirety in the documentation or other materials
     10  * provided with the distribution, and (3) all advertising materials mentioning
     11  * features or use of this software display the following acknowledgement:
     12  * ``This product includes software developed by the University of California,
     13  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
     14  * the University nor the names of its contributors may be used to endorse
     15  * or promote products derived from this software without specific prior
     16  * written permission.
     17  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
     18  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
     19  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
     20  */
     21 
     22 #include <sys/cdefs.h>
     23 #ifndef lint
     24 __RCSID("$NetBSD: print-igmp.c,v 1.5 2014/11/20 03:05:03 christos Exp $");
     25 #endif
     26 
     27 #define NETDISSECT_REWORKED
     28 #ifdef HAVE_CONFIG_H
     29 #include "config.h"
     30 #endif
     31 
     32 #include <tcpdump-stdinc.h>
     33 
     34 #include "interface.h"
     35 #include "addrtoname.h"
     36 #include "extract.h"            /* must come after interface.h */
     37 
     38 #ifndef IN_CLASSD
     39 #define IN_CLASSD(i) (((int32_t)(i) & 0xf0000000) == 0xe0000000)
     40 #endif
     41 
     42 static const char tstr[] = "[|igmp]";
     43 
     44 /* (following from ipmulti/mrouted/prune.h) */
     45 
     46 /*
     47  * The packet format for a traceroute request.
     48  */
     49 struct tr_query {
     50     uint32_t  tr_src;          /* traceroute source */
     51     uint32_t  tr_dst;          /* traceroute destination */
     52     uint32_t  tr_raddr;        /* traceroute response address */
     53     uint32_t  tr_rttlqid;      /* response ttl and qid */
     54 };
     55 
     56 #define TR_GETTTL(x)        (int)(((x) >> 24) & 0xff)
     57 #define TR_GETQID(x)        ((x) & 0x00ffffff)
     58 
     59 /*
     60  * Traceroute response format.  A traceroute response has a tr_query at the
     61  * beginning, followed by one tr_resp for each hop taken.
     62  */
     63 struct tr_resp {
     64     uint32_t tr_qarr;          /* query arrival time */
     65     uint32_t tr_inaddr;        /* incoming interface address */
     66     uint32_t tr_outaddr;       /* outgoing interface address */
     67     uint32_t tr_rmtaddr;       /* parent address in source tree */
     68     uint32_t tr_vifin;         /* input packet count on interface */
     69     uint32_t tr_vifout;        /* output packet count on interface */
     70     uint32_t tr_pktcnt;        /* total incoming packets for src-grp */
     71     uint8_t  tr_rproto;      /* routing proto deployed on router */
     72     uint8_t  tr_fttl;        /* ttl required to forward on outvif */
     73     uint8_t  tr_smask;       /* subnet mask for src addr */
     74     uint8_t  tr_rflags;      /* forwarding error codes */
     75 };
     76 
     77 /* defs within mtrace */
     78 #define TR_QUERY 1
     79 #define TR_RESP 2
     80 
     81 /* fields for tr_rflags (forwarding error codes) */
     82 #define TR_NO_ERR   0
     83 #define TR_WRONG_IF 1
     84 #define TR_PRUNED   2
     85 #define TR_OPRUNED  3
     86 #define TR_SCOPED   4
     87 #define TR_NO_RTE   5
     88 #define TR_NO_FWD   7
     89 #define TR_NO_SPACE 0x81
     90 #define TR_OLD_ROUTER   0x82
     91 
     92 /* fields for tr_rproto (routing protocol) */
     93 #define TR_PROTO_DVMRP  1
     94 #define TR_PROTO_MOSPF  2
     95 #define TR_PROTO_PIM    3
     96 #define TR_PROTO_CBT    4
     97 
     98 /* igmpv3 report types */
     99 static const struct tok igmpv3report2str[] = {
    100 	{ 1,	"is_in" },
    101 	{ 2,	"is_ex" },
    102 	{ 3,	"to_in" },
    103 	{ 4,	"to_ex" },
    104 	{ 5,	"allow" },
    105 	{ 6,	"block" },
    106 	{ 0,	NULL }
    107 };
    108 
    109 static void
    110 print_mtrace(netdissect_options *ndo,
    111              register const u_char *bp, register u_int len)
    112 {
    113     register const struct tr_query *tr = (const struct tr_query *)(bp + 8);
    114 
    115     ND_TCHECK(*tr);
    116     if (len < 8 + sizeof (struct tr_query)) {
    117 	ND_PRINT((ndo, " [invalid len %d]", len));
    118 	return;
    119     }
    120     ND_PRINT((ndo, "mtrace %u: %s to %s reply-to %s",
    121         TR_GETQID(EXTRACT_32BITS(&tr->tr_rttlqid)),
    122         ipaddr_string(ndo, &tr->tr_src), ipaddr_string(ndo, &tr->tr_dst),
    123         ipaddr_string(ndo, &tr->tr_raddr)));
    124     if (IN_CLASSD(EXTRACT_32BITS(&tr->tr_raddr)))
    125         ND_PRINT((ndo, " with-ttl %d", TR_GETTTL(EXTRACT_32BITS(&tr->tr_rttlqid))));
    126     return;
    127 trunc:
    128     ND_PRINT((ndo, "%s", tstr));
    129 }
    130 
    131 static void
    132 print_mresp(netdissect_options *ndo,
    133             register const u_char *bp, register u_int len)
    134 {
    135     register const struct tr_query *tr = (const struct tr_query *)(bp + 8);
    136 
    137     ND_TCHECK(*tr);
    138     if (len < 8 + sizeof (struct tr_query)) {
    139 	ND_PRINT((ndo, " [invalid len %d]", len));
    140 	return;
    141     }
    142     ND_PRINT((ndo, "mresp %lu: %s to %s reply-to %s",
    143         (u_long)TR_GETQID(EXTRACT_32BITS(&tr->tr_rttlqid)),
    144         ipaddr_string(ndo, &tr->tr_src), ipaddr_string(ndo, &tr->tr_dst),
    145         ipaddr_string(ndo, &tr->tr_raddr)));
    146     if (IN_CLASSD(EXTRACT_32BITS(&tr->tr_raddr)))
    147         ND_PRINT((ndo, " with-ttl %d", TR_GETTTL(EXTRACT_32BITS(&tr->tr_rttlqid))));
    148     return;
    149 trunc:
    150     ND_PRINT((ndo, "%s", tstr));
    151 }
    152 
    153 static void
    154 print_igmpv3_report(netdissect_options *ndo,
    155                     register const u_char *bp, register u_int len)
    156 {
    157     u_int group, nsrcs, ngroups;
    158     register u_int i, j;
    159 
    160     /* Minimum len is 16, and should be a multiple of 4 */
    161     if (len < 16 || len & 0x03) {
    162 	ND_PRINT((ndo, " [invalid len %d]", len));
    163 	return;
    164     }
    165     ND_TCHECK2(bp[6], 2);
    166     ngroups = EXTRACT_16BITS(&bp[6]);
    167     ND_PRINT((ndo, ", %d group record(s)", ngroups));
    168     if (ndo->ndo_vflag > 0) {
    169 	/* Print the group records */
    170 	group = 8;
    171         for (i=0; i<ngroups; i++) {
    172 	    if (len < group+8) {
    173 		ND_PRINT((ndo, " [invalid number of groups]"));
    174 		return;
    175 	    }
    176 	    ND_TCHECK2(bp[group+4], 4);
    177             ND_PRINT((ndo, " [gaddr %s", ipaddr_string(ndo, &bp[group+4])));
    178 	    ND_PRINT((ndo, " %s", tok2str(igmpv3report2str, " [v3-report-#%d]",
    179 								bp[group])));
    180             nsrcs = EXTRACT_16BITS(&bp[group+2]);
    181 	    /* Check the number of sources and print them */
    182 	    if (len < group+8+(nsrcs<<2)) {
    183 		ND_PRINT((ndo, " [invalid number of sources %d]", nsrcs));
    184 		return;
    185 	    }
    186             if (ndo->ndo_vflag == 1)
    187                 ND_PRINT((ndo, ", %d source(s)", nsrcs));
    188             else {
    189 		/* Print the sources */
    190                 ND_PRINT((ndo, " {"));
    191                 for (j=0; j<nsrcs; j++) {
    192 		    ND_TCHECK2(bp[group+8+(j<<2)], 4);
    193 		    ND_PRINT((ndo, " %s", ipaddr_string(ndo, &bp[group+8+(j<<2)])));
    194 		}
    195                 ND_PRINT((ndo, " }"));
    196             }
    197 	    /* Next group record */
    198             group += 8 + (nsrcs << 2);
    199 	    ND_PRINT((ndo, "]"));
    200         }
    201     }
    202     return;
    203 trunc:
    204     ND_PRINT((ndo, "%s", tstr));
    205 }
    206 
    207 static void
    208 print_igmpv3_query(netdissect_options *ndo,
    209                    register const u_char *bp, register u_int len)
    210 {
    211     u_int mrc;
    212     int mrt;
    213     u_int nsrcs;
    214     register u_int i;
    215 
    216     ND_PRINT((ndo, " v3"));
    217     /* Minimum len is 12, and should be a multiple of 4 */
    218     if (len < 12 || len & 0x03) {
    219 	ND_PRINT((ndo, " [invalid len %d]", len));
    220 	return;
    221     }
    222     ND_TCHECK(bp[1]);
    223     mrc = bp[1];
    224     if (mrc < 128) {
    225 	mrt = mrc;
    226     } else {
    227         mrt = ((mrc & 0x0f) | 0x10) << (((mrc & 0x70) >> 4) + 3);
    228     }
    229     if (mrc != 100) {
    230 	ND_PRINT((ndo, " [max resp time "));
    231         if (mrt < 600) {
    232             ND_PRINT((ndo, "%.1fs", mrt * 0.1));
    233         } else {
    234             relts_print(ndo, mrt / 10);
    235         }
    236 	ND_PRINT((ndo, "]"));
    237     }
    238     ND_TCHECK2(bp[4], 4);
    239     if (EXTRACT_32BITS(&bp[4]) == 0)
    240 	return;
    241     ND_PRINT((ndo, " [gaddr %s", ipaddr_string(ndo, &bp[4])));
    242     ND_TCHECK2(bp[10], 2);
    243     nsrcs = EXTRACT_16BITS(&bp[10]);
    244     if (nsrcs > 0) {
    245 	if (len < 12 + (nsrcs << 2))
    246 	    ND_PRINT((ndo, " [invalid number of sources]"));
    247 	else if (ndo->ndo_vflag > 1) {
    248 	    ND_PRINT((ndo, " {"));
    249 	    for (i=0; i<nsrcs; i++) {
    250 		ND_TCHECK2(bp[12+(i<<2)], 4);
    251 		ND_PRINT((ndo, " %s", ipaddr_string(ndo, &bp[12+(i<<2)])));
    252 	    }
    253 	    ND_PRINT((ndo, " }"));
    254 	} else
    255 	    ND_PRINT((ndo, ", %d source(s)", nsrcs));
    256     }
    257     ND_PRINT((ndo, "]"));
    258     return;
    259 trunc:
    260     ND_PRINT((ndo, "%s", tstr));
    261 }
    262 
    263 void
    264 igmp_print(netdissect_options *ndo,
    265            register const u_char *bp, register u_int len)
    266 {
    267     struct cksum_vec vec[1];
    268 
    269     if (ndo->ndo_qflag) {
    270         ND_PRINT((ndo, "igmp"));
    271         return;
    272     }
    273 
    274     ND_TCHECK(bp[0]);
    275     switch (bp[0]) {
    276     case 0x11:
    277         ND_PRINT((ndo, "igmp query"));
    278 	if (len >= 12)
    279 	    print_igmpv3_query(ndo, bp, len);
    280 	else {
    281             ND_TCHECK(bp[1]);
    282 	    if (bp[1]) {
    283 		ND_PRINT((ndo, " v2"));
    284 		if (bp[1] != 100)
    285 		    ND_PRINT((ndo, " [max resp time %d]", bp[1]));
    286 	    } else
    287 		ND_PRINT((ndo, " v1"));
    288             ND_TCHECK2(bp[4], 4);
    289 	    if (EXTRACT_32BITS(&bp[4]))
    290                 ND_PRINT((ndo, " [gaddr %s]", ipaddr_string(ndo, &bp[4])));
    291             if (len != 8)
    292                 ND_PRINT((ndo, " [len %d]", len));
    293 	}
    294         break;
    295     case 0x12:
    296         ND_TCHECK2(bp[4], 4);
    297         ND_PRINT((ndo, "igmp v1 report %s", ipaddr_string(ndo, &bp[4])));
    298         if (len != 8)
    299             ND_PRINT((ndo, " [len %d]", len));
    300         break;
    301     case 0x16:
    302         ND_TCHECK2(bp[4], 4);
    303         ND_PRINT((ndo, "igmp v2 report %s", ipaddr_string(ndo, &bp[4])));
    304         break;
    305     case 0x22:
    306         ND_PRINT((ndo, "igmp v3 report"));
    307 	print_igmpv3_report(ndo, bp, len);
    308         break;
    309     case 0x17:
    310         ND_TCHECK2(bp[4], 4);
    311         ND_PRINT((ndo, "igmp leave %s", ipaddr_string(ndo, &bp[4])));
    312         break;
    313     case 0x13:
    314         ND_PRINT((ndo, "igmp dvmrp"));
    315         if (len < 8)
    316             ND_PRINT((ndo, " [len %d]", len));
    317         else
    318             dvmrp_print(ndo, bp, len);
    319         break;
    320     case 0x14:
    321         ND_PRINT((ndo, "igmp pimv1"));
    322         pimv1_print(ndo, bp, len);
    323         break;
    324     case 0x1e:
    325         print_mresp(ndo, bp, len);
    326         break;
    327     case 0x1f:
    328         print_mtrace(ndo, bp, len);
    329         break;
    330     default:
    331         ND_PRINT((ndo, "igmp-%d", bp[0]));
    332         break;
    333     }
    334 
    335     if (ndo->ndo_vflag && ND_TTEST2(bp[0], len)) {
    336         /* Check the IGMP checksum */
    337         vec[0].ptr = bp;
    338         vec[0].len = len;
    339         if (in_cksum(vec, 1))
    340             ND_PRINT((ndo, " bad igmp cksum %x!", EXTRACT_16BITS(&bp[2])));
    341     }
    342     return;
    343 trunc:
    344     ND_PRINT((ndo, "%s", tstr));
    345 }
    346