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 static const char tstr[] = "[|igmp]";
  47
  48 /* (following from ipmulti/mrouted/prune.h) */
  49
  50 /*
  51  * The packet format for a traceroute request.
  52  */
  53 struct tr_query {
  54     nd_uint32_t  tr_src;        /* traceroute source */
  55     nd_uint32_t  tr_dst;        /* traceroute destination */
  56     nd_uint32_t  tr_raddr;      /* traceroute response address */
  57     nd_uint8_t   tr_rttl;       /* response ttl */
  58     nd_uint24_t  tr_qid;        /* qid */
  59 };
  60
  61 /*
  62  * Traceroute response format.  A traceroute response has a tr_query at the
  63  * beginning, followed by one tr_resp for each hop taken.
  64  */
  65 struct tr_resp {
  66     nd_uint32_t tr_qarr;        /* query arrival time */
  67     nd_uint32_t tr_inaddr;      /* incoming interface address */
  68     nd_uint32_t tr_outaddr;     /* outgoing interface address */
  69     nd_uint32_t tr_rmtaddr;     /* parent address in source tree */
  70     nd_uint32_t tr_vifin;       /* input packet count on interface */
  71     nd_uint32_t tr_vifout;      /* output packet count on interface */
  72     nd_uint32_t tr_pktcnt;      /* total incoming packets for src-grp */
  73     nd_uint8_t  tr_rproto;      /* routing proto deployed on router */
  74     nd_uint8_t  tr_fttl;        /* ttl required to forward on outvif */
  75     nd_uint8_t  tr_smask;       /* subnet mask for src addr */
  76     nd_uint8_t  tr_rflags;      /* forwarding error codes */
  77 };
  78
  79 /* defs within mtrace */
  80 #define TR_QUERY 1
  81 #define TR_RESP 2
  82
  83 /* fields for tr_rflags (forwarding error codes) */
  84 #define TR_NO_ERR   0
  85 #define TR_WRONG_IF 1
  86 #define TR_PRUNED   2
  87 #define TR_OPRUNED  3
  88 #define TR_SCOPED   4
  89 #define TR_NO_RTE   5
  90 #define TR_NO_FWD   7
  91 #define TR_NO_SPACE 0x81
  92 #define TR_OLD_ROUTER   0x82
  93
  94 /* fields for tr_rproto (routing protocol) */
  95 #define TR_PROTO_DVMRP  1
  96 #define TR_PROTO_MOSPF  2
  97 #define TR_PROTO_PIM    3
  98 #define TR_PROTO_CBT    4
  99
 100 /* igmpv3 report types */
 101 static const struct tok igmpv3report2str[] = {
 102         { 1,    "is_in" },
 103         { 2,    "is_ex" },
 104         { 3,    "to_in" },
 105         { 4,    "to_ex" },
 106         { 5,    "allow" },
 107         { 6,    "block" },
 108         { 0,    NULL }
 109 };
 110
 111 static void
 112 print_mtrace(netdissect_options *ndo,
 113              const u_char *bp, u_int len)
 114 {
 115     const struct tr_query *tr = (const struct tr_query *)(bp + 8);
 116
 117     ND_TCHECK_SIZE(tr);
 118     if (len < 8 + sizeof (struct tr_query)) {
 119         ND_PRINT(" [invalid len %u]", len);
 120         return;
 121     }
 122     ND_PRINT("mtrace %u: %s to %s reply-to %s",
 123         EXTRACT_BE_U_3(tr->tr_qid),
 124         ipaddr_string(ndo, tr->tr_src), ipaddr_string(ndo, tr->tr_dst),
 125         ipaddr_string(ndo, tr->tr_raddr));
 126     if (IN_CLASSD(EXTRACT_BE_U_4(tr->tr_raddr)))
 127         ND_PRINT(" with-ttl %u", EXTRACT_U_1(tr->tr_rttl));
 128     return;
 129 trunc:
 130     ND_PRINT("%s", tstr);
 131 }
 132
 133 static void
 134 print_mresp(netdissect_options *ndo,
 135             const u_char *bp, u_int len)
 136 {
 137     const struct tr_query *tr = (const struct tr_query *)(bp + 8);
 138
 139     ND_TCHECK_SIZE(tr);
 140     if (len < 8 + sizeof (struct tr_query)) {
 141         ND_PRINT(" [invalid len %u]", len);
 142         return;
 143     }
 144     ND_PRINT("mresp %u: %s to %s reply-to %s",
 145         EXTRACT_BE_U_3(tr->tr_qid),
 146         ipaddr_string(ndo, tr->tr_src), ipaddr_string(ndo, tr->tr_dst),
 147         ipaddr_string(ndo, tr->tr_raddr));
 148     if (IN_CLASSD(EXTRACT_BE_U_4(tr->tr_raddr)))
 149         ND_PRINT(" with-ttl %u", EXTRACT_U_1(tr->tr_rttl));
 150     return;
 151 trunc:
 152     ND_PRINT("%s", tstr);
 153 }
 154
 155 static void
 156 print_igmpv3_report(netdissect_options *ndo,
 157                     const u_char *bp, u_int len)
 158 {
 159     u_int group, nsrcs, ngroups;
 160     u_int i, j;
 161
 162     /* Minimum len is 16, and should be a multiple of 4 */
 163     if (len < 16 || len & 0x03) {
 164         ND_PRINT(" [invalid len %u]", len);
 165         return;
 166     }
 167     ND_TCHECK_2(bp + 6);
 168     ngroups = EXTRACT_BE_U_2(bp + 6);
 169     ND_PRINT(", %u group record(s)", ngroups);
 170     if (ndo->ndo_vflag > 0) {
 171         /* Print the group records */
 172         group = 8;
 173         for (i=0; i<ngroups; i++) {
 174             if (len < group+8) {
 175                 ND_PRINT(" [invalid number of groups]");
 176                 return;
 177             }
 178             ND_TCHECK_4(bp + (group + 4));
 179             ND_PRINT(" [gaddr %s", ipaddr_string(ndo, bp + group + 4));
 180             ND_PRINT(" %s", tok2str(igmpv3report2str, " [v3-report-#%u]",
 181                                                                 EXTRACT_U_1(bp + group)));
 182             nsrcs = EXTRACT_BE_U_2(bp + group + 2);
 183             /* Check the number of sources and print them */
 184             if (len < group+8+(nsrcs<<2)) {
 185                 ND_PRINT(" [invalid number of sources %u]", nsrcs);
 186                 return;
 187             }
 188             if (ndo->ndo_vflag == 1)
 189                 ND_PRINT(", %u source(s)", nsrcs);
 190             else {
 191                 /* Print the sources */
 192                 ND_PRINT(" {");
 193                 for (j=0; j<nsrcs; j++) {
 194                     ND_TCHECK_4(bp + (group + 8 + (j << 2)));
 195                     ND_PRINT(" %s", ipaddr_string(ndo, bp + group + 8 + (j << 2)));
 196                 }
 197                 ND_PRINT(" }");
 198             }
 199             /* Next group record */
 200             group += 8 + (nsrcs << 2);
 201             ND_PRINT("]");
 202         }
 203     }
 204     return;
 205 trunc:
 206     ND_PRINT("%s", tstr);
 207 }
 208
 209 static void
 210 print_igmpv3_query(netdissect_options *ndo,
 211                    const u_char *bp, u_int len)
 212 {
 213     u_int mrc;
 214     u_int mrt;
 215     u_int nsrcs;
 216     u_int i;
 217
 218     ND_PRINT(" v3");
 219     /* Minimum len is 12, and should be a multiple of 4 */
 220     if (len < 12 || len & 0x03) {
 221         ND_PRINT(" [invalid len %u]", len);
 222         return;
 223     }
 224     ND_TCHECK_1(bp + 1);
 225     mrc = EXTRACT_U_1(bp + 1);
 226     if (mrc < 128) {
 227         mrt = mrc;
 228     } else {
 229         mrt = ((mrc & 0x0f) | 0x10) << (((mrc & 0x70) >> 4) + 3);
 230     }
 231     if (mrc != 100) {
 232         ND_PRINT(" [max resp time ");
 233         if (mrt < 600) {
 234             ND_PRINT("%.1fs", mrt * 0.1);
 235         } else {
 236             unsigned_relts_print(ndo, mrt / 10);
 237         }
 238         ND_PRINT("]");
 239     }
 240     ND_TCHECK_4(bp + 4);
 241     if (EXTRACT_BE_U_4(bp + 4) == 0)
 242         return;
 243     ND_PRINT(" [gaddr %s", ipaddr_string(ndo, bp + 4));
 244     ND_TCHECK_2(bp + 10);
 245     nsrcs = EXTRACT_BE_U_2(bp + 10);
 246     if (nsrcs > 0) {
 247         if (len < 12 + (nsrcs << 2))
 248             ND_PRINT(" [invalid number of sources]");
 249         else if (ndo->ndo_vflag > 1) {
 250             ND_PRINT(" {");
 251             for (i=0; i<nsrcs; i++) {
 252                 ND_TCHECK_4(bp + (12 + (i << 2)));
 253                 ND_PRINT(" %s", ipaddr_string(ndo, bp + 12 + (i << 2)));
 254             }
 255             ND_PRINT(" }");
 256         } else
 257             ND_PRINT(", %u source(s)", nsrcs);
 258     }
 259     ND_PRINT("]");
 260     return;
 261 trunc:
 262     ND_PRINT("%s", tstr);
 263 }
 264
 265 void
 266 igmp_print(netdissect_options *ndo,
 267            const u_char *bp, u_int len)
 268 {
 269     struct cksum_vec vec[1];
 270
 271     ndo->ndo_protocol = "igmp";
 272     if (ndo->ndo_qflag) {
 273         ND_PRINT("igmp");
 274         return;
 275     }
 276
 277     ND_TCHECK_1(bp);
 278     switch (EXTRACT_U_1(bp)) {
 279     case 0x11:
 280         ND_PRINT("igmp query");
 281         if (len >= 12)
 282             print_igmpv3_query(ndo, bp, len);
 283         else {
 284             ND_TCHECK_1(bp + 1);
 285             if (EXTRACT_U_1(bp + 1)) {
 286                 ND_PRINT(" v2");
 287                 if (EXTRACT_U_1(bp + 1) != 100)
 288                     ND_PRINT(" [max resp time %u]", EXTRACT_U_1(bp + 1));
 289             } else
 290                 ND_PRINT(" v1");
 291             ND_TCHECK_4(bp + 4);
 292             if (EXTRACT_BE_U_4(bp + 4))
 293                 ND_PRINT(" [gaddr %s]", ipaddr_string(ndo, bp + 4));
 294             if (len != 8)
 295                 ND_PRINT(" [len %u]", len);
 296         }
 297         break;
 298     case 0x12:
 299         ND_TCHECK_4(bp + 4);
 300         ND_PRINT("igmp v1 report %s", ipaddr_string(ndo, bp + 4));
 301         if (len != 8)
 302             ND_PRINT(" [len %u]", len);
 303         break;
 304     case 0x16:
 305         ND_TCHECK_4(bp + 4);
 306         ND_PRINT("igmp v2 report %s", ipaddr_string(ndo, bp + 4));
 307         break;
 308     case 0x22:
 309         ND_PRINT("igmp v3 report");
 310         print_igmpv3_report(ndo, bp, len);
 311         break;
 312     case 0x17:
 313         ND_TCHECK_4(bp + 4);
 314         ND_PRINT("igmp leave %s", ipaddr_string(ndo, bp + 4));
 315         break;
 316     case 0x13:
 317         ND_PRINT("igmp dvmrp");
 318         if (len < 8)
 319             ND_PRINT(" [len %u]", len);
 320         else
 321             dvmrp_print(ndo, bp, len);
 322         break;
 323     case 0x14:
 324         ND_PRINT("igmp pimv1");
 325         pimv1_print(ndo, bp, len);
 326         break;
 327     case 0x1e:
 328         print_mresp(ndo, bp, len);
 329         break;
 330     case 0x1f:
 331         print_mtrace(ndo, bp, len);
 332         break;
 333     default:
 334         ND_PRINT("igmp-%u", EXTRACT_U_1(bp));
 335         break;
 336     }
 337
 338     if (ndo->ndo_vflag && len >= 4 && ND_TTEST_LEN(bp, len)) {
 339         /* Check the IGMP checksum */
 340         vec[0].ptr = bp;
 341         vec[0].len = len;
 342         if (in_cksum(vec, 1))
 343             ND_PRINT(" bad igmp cksum %x!", EXTRACT_BE_U_2(bp + 2));
 344     }
 345     return;
 346 trunc:
 347     ND_PRINT("%s", tstr);
 348 }