The Tcpdump Group git mirrors - tcpdump/blob - print-igmp.c

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