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 /* \summary: Internet Group Management Protocol (IGMP) printer */
  23
  24 /*
  25  * specification:
  26  *
  27  *      RFC 2236 for IGMPv2
  28  *      RFC 3376 for IGMPv3
  29  *      draft-asaeda-mboned-mtrace-v2 for the mtrace message
  30  */
  31
  32 #ifdef HAVE_CONFIG_H
  33 #include <config.h>
  34 #endif
  35
  36 #include "netdissect-stdinc.h"
  37
  38 #include "netdissect.h"
  39 #include "addrtoname.h"
  40 #include "extract.h"
  41
  42 #ifndef IN_CLASSD
  43 #define IN_CLASSD(i) (((int32_t)(i) & 0xf0000000) == 0xe0000000)
  44 #endif
  45
  46
  47 /* (following from ipmulti/mrouted/prune.h) */
  48
  49 /*
  50  * The packet format for a traceroute request.
  51  */
  52 struct tr_query {
  53     nd_uint32_t  tr_src;        /* traceroute source */
  54     nd_uint32_t  tr_dst;        /* traceroute destination */
  55     nd_uint32_t  tr_raddr;      /* traceroute response address */
  56     nd_uint8_t   tr_rttl;       /* response ttl */
  57     nd_uint24_t  tr_qid;        /* qid */
  58 };
  59
  60 /*
  61  * Traceroute response format.  A traceroute response has a tr_query at the
  62  * beginning, followed by one tr_resp for each hop taken.
  63  */
  64 struct tr_resp {
  65     nd_uint32_t tr_qarr;        /* query arrival time */
  66     nd_uint32_t tr_inaddr;      /* incoming interface address */
  67     nd_uint32_t tr_outaddr;     /* outgoing interface address */
  68     nd_uint32_t tr_rmtaddr;     /* parent address in source tree */
  69     nd_uint32_t tr_vifin;       /* input packet count on interface */
  70     nd_uint32_t tr_vifout;      /* output packet count on interface */
  71     nd_uint32_t tr_pktcnt;      /* total incoming packets for src-grp */
  72     nd_uint8_t  tr_rproto;      /* routing proto deployed on router */
  73     nd_uint8_t  tr_fttl;        /* ttl required to forward on outvif */
  74     nd_uint8_t  tr_smask;       /* subnet mask for src addr */
  75     nd_uint8_t  tr_rflags;      /* forwarding error codes */
  76 };
  77
  78 /* defs within mtrace */
  79 #define TR_QUERY 1
  80 #define TR_RESP 2
  81
  82 /* fields for tr_rflags (forwarding error codes) */
  83 #define TR_NO_ERR   0
  84 #define TR_WRONG_IF 1
  85 #define TR_PRUNED   2
  86 #define TR_OPRUNED  3
  87 #define TR_SCOPED   4
  88 #define TR_NO_RTE   5
  89 #define TR_NO_FWD   7
  90 #define TR_NO_SPACE 0x81
  91 #define TR_OLD_ROUTER   0x82
  92
  93 /* fields for tr_rproto (routing protocol) */
  94 #define TR_PROTO_DVMRP  1
  95 #define TR_PROTO_MOSPF  2
  96 #define TR_PROTO_PIM    3
  97 #define TR_PROTO_CBT    4
  98
  99 /* igmpv3 report types */
 100 static const struct tok igmpv3report2str[] = {
 101         { 1,    "is_in" },
 102         { 2,    "is_ex" },
 103         { 3,    "to_in" },
 104         { 4,    "to_ex" },
 105         { 5,    "allow" },
 106         { 6,    "block" },
 107         { 0,    NULL }
 108 };
 109
 110 static void
 111 print_mtrace(netdissect_options *ndo,
 112              const u_char *bp, u_int len)
 113 {
 114     const struct tr_query *tr = (const struct tr_query *)(bp + 8);
 115
 116     ND_TCHECK_SIZE(tr);
 117     if (len < 8 + sizeof (struct tr_query)) {
 118         ND_PRINT(" [invalid len %u]", len);
 119         return;
 120     }
 121     ND_PRINT("mtrace %u: %s to %s reply-to %s",
 122         GET_BE_U_3(tr->tr_qid),
 123         GET_IPADDR_STRING(tr->tr_src), GET_IPADDR_STRING(tr->tr_dst),
 124         GET_IPADDR_STRING(tr->tr_raddr));
 125     if (IN_CLASSD(GET_BE_U_4(tr->tr_raddr)))
 126         ND_PRINT(" with-ttl %u", GET_U_1(tr->tr_rttl));
 127     return;
 128 trunc:
 129     nd_print_trunc(ndo);
 130 }
 131
 132 static void
 133 print_mresp(netdissect_options *ndo,
 134             const u_char *bp, u_int len)
 135 {
 136     const struct tr_query *tr = (const struct tr_query *)(bp + 8);
 137
 138     ND_TCHECK_SIZE(tr);
 139     if (len < 8 + sizeof (struct tr_query)) {
 140         ND_PRINT(" [invalid len %u]", len);
 141         return;
 142     }
 143     ND_PRINT("mresp %u: %s to %s reply-to %s",
 144         GET_BE_U_3(tr->tr_qid),
 145         GET_IPADDR_STRING(tr->tr_src), GET_IPADDR_STRING(tr->tr_dst),
 146         GET_IPADDR_STRING(tr->tr_raddr));
 147     if (IN_CLASSD(GET_BE_U_4(tr->tr_raddr)))
 148         ND_PRINT(" with-ttl %u", GET_U_1(tr->tr_rttl));
 149     return;
 150 trunc:
 151     nd_print_trunc(ndo);
 152 }
 153
 154 static void
 155 print_igmpv3_report(netdissect_options *ndo,
 156                     const u_char *bp, u_int len)
 157 {
 158     u_int group, nsrcs, ngroups;
 159     u_int i, j;
 160
 161     /* Minimum len is 16, and should be a multiple of 4 */
 162     if (len < 16 || len & 0x03) {
 163         ND_PRINT(" [invalid len %u]", len);
 164         return;
 165     }
 166     ngroups = GET_BE_U_2(bp + 6);
 167     ND_PRINT(", %u 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(" [invalid number of groups]");
 174                 return;
 175             }
 176             ND_TCHECK_4(bp + (group + 4));
 177             ND_PRINT(" [gaddr %s", GET_IPADDR_STRING(bp + group + 4));
 178             ND_PRINT(" %s", tok2str(igmpv3report2str, " [v3-report-#%u]",
 179                                                                 GET_U_1(bp + group)));
 180             nsrcs = GET_BE_U_2(bp + group + 2);
 181             /* Check the number of sources and print them */
 182             if (len < group+8+(nsrcs<<2)) {
 183                 ND_PRINT(" [invalid number of sources %u]", nsrcs);
 184                 return;
 185             }
 186             if (ndo->ndo_vflag == 1)
 187                 ND_PRINT(", %u source(s)", nsrcs);
 188             else {
 189                 /* Print the sources */
 190                 ND_PRINT(" {");
 191                 for (j=0; j<nsrcs; j++) {
 192                     ND_TCHECK_4(bp + (group + 8 + (j << 2)));
 193                     ND_PRINT(" %s", GET_IPADDR_STRING(bp + group + 8 + (j << 2)));
 194                 }
 195                 ND_PRINT(" }");
 196             }
 197             /* Next group record */
 198             group += 8 + (nsrcs << 2);
 199             ND_PRINT("]");
 200         }
 201     }
 202     return;
 203 trunc:
 204     nd_print_trunc(ndo);
 205 }
 206
 207 static void
 208 print_igmpv3_query(netdissect_options *ndo,
 209                    const u_char *bp, u_int len)
 210 {
 211     u_int mrc;
 212     u_int mrt;
 213     u_int nsrcs;
 214     u_int i;
 215
 216     ND_PRINT(" v3");
 217     /* Minimum len is 12, and should be a multiple of 4 */
 218     if (len < 12 || len & 0x03) {
 219         ND_PRINT(" [invalid len %u]", len);
 220         return;
 221     }
 222     mrc = GET_U_1(bp + 1);
 223     if (mrc < 128) {
 224         mrt = mrc;
 225     } else {
 226         mrt = ((mrc & 0x0f) | 0x10) << (((mrc & 0x70) >> 4) + 3);
 227     }
 228     if (mrc != 100) {
 229         ND_PRINT(" [max resp time ");
 230         if (mrt < 600) {
 231             ND_PRINT("%.1fs", mrt * 0.1);
 232         } else {
 233             unsigned_relts_print(ndo, mrt / 10);
 234         }
 235         ND_PRINT("]");
 236     }
 237     if (GET_BE_U_4(bp + 4) == 0)
 238         return;
 239     ND_PRINT(" [gaddr %s", GET_IPADDR_STRING(bp + 4));
 240     nsrcs = GET_BE_U_2(bp + 10);
 241     if (nsrcs > 0) {
 242         if (len < 12 + (nsrcs << 2))
 243             ND_PRINT(" [invalid number of sources]");
 244         else if (ndo->ndo_vflag > 1) {
 245             ND_PRINT(" {");
 246             for (i=0; i<nsrcs; i++) {
 247                 ND_TCHECK_4(bp + (12 + (i << 2)));
 248                 ND_PRINT(" %s", GET_IPADDR_STRING(bp + 12 + (i << 2)));
 249             }
 250             ND_PRINT(" }");
 251         } else
 252             ND_PRINT(", %u source(s)", nsrcs);
 253     }
 254     ND_PRINT("]");
 255     return;
 256 trunc:
 257     nd_print_trunc(ndo);
 258 }
 259
 260 void
 261 igmp_print(netdissect_options *ndo,
 262            const u_char *bp, u_int len)
 263 {
 264     struct cksum_vec vec[1];
 265
 266     ndo->ndo_protocol = "igmp";
 267     if (ndo->ndo_qflag) {
 268         ND_PRINT("igmp");
 269         return;
 270     }
 271
 272     switch (GET_U_1(bp)) {
 273     case 0x11:
 274         ND_PRINT("igmp query");
 275         if (len >= 12)
 276             print_igmpv3_query(ndo, bp, len);
 277         else {
 278             if (GET_U_1(bp + 1)) {
 279                 ND_PRINT(" v2");
 280                 if (GET_U_1(bp + 1) != 100)
 281                     ND_PRINT(" [max resp time %u]", GET_U_1(bp + 1));
 282             } else
 283                 ND_PRINT(" v1");
 284             if (GET_BE_U_4(bp + 4))
 285                 ND_PRINT(" [gaddr %s]", GET_IPADDR_STRING(bp + 4));
 286             if (len != 8)
 287                 ND_PRINT(" [len %u]", len);
 288         }
 289         break;
 290     case 0x12:
 291         ND_PRINT("igmp v1 report %s", GET_IPADDR_STRING(bp + 4));
 292         if (len != 8)
 293             ND_PRINT(" [len %u]", len);
 294         break;
 295     case 0x16:
 296         ND_PRINT("igmp v2 report %s", GET_IPADDR_STRING(bp + 4));
 297         break;
 298     case 0x22:
 299         ND_PRINT("igmp v3 report");
 300         print_igmpv3_report(ndo, bp, len);
 301         break;
 302     case 0x17:
 303         ND_PRINT("igmp leave %s", GET_IPADDR_STRING(bp + 4));
 304         break;
 305     case 0x13:
 306         ND_PRINT("igmp dvmrp");
 307         if (len < 8)
 308             ND_PRINT(" [len %u]", len);
 309         else
 310             dvmrp_print(ndo, bp, len);
 311         break;
 312     case 0x14:
 313         ND_PRINT("igmp pimv1");
 314         pimv1_print(ndo, bp, len);
 315         break;
 316     case 0x1e:
 317         print_mresp(ndo, bp, len);
 318         break;
 319     case 0x1f:
 320         print_mtrace(ndo, bp, len);
 321         break;
 322     default:
 323         ND_PRINT("igmp-%u", GET_U_1(bp));
 324         break;
 325     }
 326
 327     if (ndo->ndo_vflag && len >= 4 && ND_TTEST_LEN(bp, len)) {
 328         /* Check the IGMP checksum */
 329         vec[0].ptr = bp;
 330         vec[0].len = len;
 331         if (in_cksum(vec, 1))
 332             ND_PRINT(" bad igmp cksum %x!", GET_BE_U_2(bp + 2));
 333     }
 334 }