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 #include <config.h>
  33
  34 #include "netdissect-stdinc.h"
  35
  36 #include "netdissect.h"
  37 #include "addrtoname.h"
  38 #include "extract.h"
  39
  40 #ifndef IN_CLASSD
  41 #define IN_CLASSD(i) (((int32_t)(i) & 0xf0000000) == 0xe0000000)
  42 #endif
  43
  44
  45 /* (following from ipmulti/mrouted/prune.h) */
  46
  47 /*
  48  * The packet format for a traceroute request.
  49  */
  50 struct tr_query {
  51     nd_uint32_t  tr_src;        /* traceroute source */
  52     nd_uint32_t  tr_dst;        /* traceroute destination */
  53     nd_uint32_t  tr_raddr;      /* traceroute response address */
  54     nd_uint8_t   tr_rttl;       /* response ttl */
  55     nd_uint24_t  tr_qid;        /* qid */
  56 };
  57
  58 /*
  59  * Traceroute response format.  A traceroute response has a tr_query at the
  60  * beginning, followed by one tr_resp for each hop taken.
  61  */
  62 struct tr_resp {
  63     nd_uint32_t tr_qarr;        /* query arrival time */
  64     nd_uint32_t tr_inaddr;      /* incoming interface address */
  65     nd_uint32_t tr_outaddr;     /* outgoing interface address */
  66     nd_uint32_t tr_rmtaddr;     /* parent address in source tree */
  67     nd_uint32_t tr_vifin;       /* input packet count on interface */
  68     nd_uint32_t tr_vifout;      /* output packet count on interface */
  69     nd_uint32_t tr_pktcnt;      /* total incoming packets for src-grp */
  70     nd_uint8_t  tr_rproto;      /* routing proto deployed on router */
  71     nd_uint8_t  tr_fttl;        /* ttl required to forward on outvif */
  72     nd_uint8_t  tr_smask;       /* subnet mask for src addr */
  73     nd_uint8_t  tr_rflags;      /* forwarding error codes */
  74 };
  75
  76 /* defs within mtrace */
  77 #define TR_QUERY 1
  78 #define TR_RESP 2
  79
  80 /* fields for tr_rflags (forwarding error codes) */
  81 #define TR_NO_ERR   0
  82 #define TR_WRONG_IF 1
  83 #define TR_PRUNED   2
  84 #define TR_OPRUNED  3
  85 #define TR_SCOPED   4
  86 #define TR_NO_RTE   5
  87 #define TR_NO_FWD   7
  88 #define TR_NO_SPACE 0x81
  89 #define TR_OLD_ROUTER   0x82
  90
  91 /* fields for tr_rproto (routing protocol) */
  92 #define TR_PROTO_DVMRP  1
  93 #define TR_PROTO_MOSPF  2
  94 #define TR_PROTO_PIM    3
  95 #define TR_PROTO_CBT    4
  96
  97 /* igmpv3 report types */
  98 static const struct tok igmpv3report2str[] = {
  99         { 1,    "is_in" },
 100         { 2,    "is_ex" },
 101         { 3,    "to_in" },
 102         { 4,    "to_ex" },
 103         { 5,    "allow" },
 104         { 6,    "block" },
 105         { 0,    NULL }
 106 };
 107
 108 static void
 109 print_mtrace(netdissect_options *ndo,
 110              const char *typename,
 111              const u_char *bp, u_int len)
 112 {
 113     const struct tr_query *tr = (const struct tr_query *)(bp + 8);
 114
 115     if (len < 8 + sizeof (struct tr_query)) {
 116         ND_PRINT(" [invalid len %u]", len);
 117         return;
 118     }
 119     ND_PRINT("%s %u: %s to %s reply-to %s",
 120         typename,
 121         GET_BE_U_3(tr->tr_qid),
 122         GET_IPADDR_STRING(tr->tr_src), GET_IPADDR_STRING(tr->tr_dst),
 123         GET_IPADDR_STRING(tr->tr_raddr));
 124     if (IN_CLASSD(GET_BE_U_4(tr->tr_raddr)))
 125         ND_PRINT(" with-ttl %u", GET_U_1(tr->tr_rttl));
 126 }
 127
 128 static void
 129 print_igmpv3_report(netdissect_options *ndo,
 130                     const u_char *bp, u_int len)
 131 {
 132     u_int group, nsrcs, ngroups;
 133     u_int i, j;
 134
 135     /* Minimum len is 16, and should be a multiple of 4 */
 136     if (len < 16 || len & 0x03) {
 137         ND_PRINT(" [invalid len %u]", len);
 138         return;
 139     }
 140     ngroups = GET_BE_U_2(bp + 6);
 141     ND_PRINT(", %u group record(s)", ngroups);
 142     if (ndo->ndo_vflag > 0) {
 143         /* Print the group records */
 144         group = 8;
 145         for (i=0; i<ngroups; i++) {
 146             if (len < group+8) {
 147                 ND_PRINT(" [invalid number of groups]");
 148                 return;
 149             }
 150             ND_PRINT(" [gaddr %s", GET_IPADDR_STRING(bp + group + 4));
 151             ND_PRINT(" %s", tok2str(igmpv3report2str, " [v3-report-#%u]",
 152                                                                 GET_U_1(bp + group)));
 153             nsrcs = GET_BE_U_2(bp + group + 2);
 154             /* Check the number of sources and print them */
 155             if (len < group+8+(nsrcs<<2)) {
 156                 ND_PRINT(" [invalid number of sources %u]", nsrcs);
 157                 return;
 158             }
 159             if (ndo->ndo_vflag == 1)
 160                 ND_PRINT(", %u source(s)", nsrcs);
 161             else {
 162                 /* Print the sources */
 163                 ND_PRINT(" {");
 164                 for (j=0; j<nsrcs; j++) {
 165                     ND_PRINT(" %s", GET_IPADDR_STRING(bp + group + 8 + (j << 2)));
 166                 }
 167                 ND_PRINT(" }");
 168             }
 169             /* Next group record */
 170             group += 8 + (nsrcs << 2);
 171             ND_PRINT("]");
 172         }
 173     }
 174 }
 175
 176 static void
 177 print_igmpv3_query(netdissect_options *ndo,
 178                    const u_char *bp, u_int len)
 179 {
 180     u_int mrc;
 181     u_int mrt;
 182     u_int nsrcs;
 183     u_int i;
 184
 185     ND_PRINT(" v3");
 186     /* Minimum len is 12, and should be a multiple of 4 */
 187     if (len < 12 || len & 0x03) {
 188         ND_PRINT(" [invalid len %u]", len);
 189         return;
 190     }
 191     mrc = GET_U_1(bp + 1);
 192     if (mrc < 128) {
 193         mrt = mrc;
 194     } else {
 195         mrt = ((mrc & 0x0f) | 0x10) << (((mrc & 0x70) >> 4) + 3);
 196     }
 197     if (mrc != 100) {
 198         ND_PRINT(" [max resp time ");
 199         if (mrt < 600) {
 200             ND_PRINT("%.1fs", mrt * 0.1);
 201         } else {
 202             unsigned_relts_print(ndo, mrt / 10);
 203         }
 204         ND_PRINT("]");
 205     }
 206     if (GET_BE_U_4(bp + 4) == 0)
 207         return;
 208     ND_PRINT(" [gaddr %s", GET_IPADDR_STRING(bp + 4));
 209     nsrcs = GET_BE_U_2(bp + 10);
 210     if (nsrcs > 0) {
 211         if (len < 12 + (nsrcs << 2))
 212             ND_PRINT(" [invalid number of sources]");
 213         else if (ndo->ndo_vflag > 1) {
 214             ND_PRINT(" {");
 215             for (i=0; i<nsrcs; i++) {
 216                 ND_PRINT(" %s", GET_IPADDR_STRING(bp + 12 + (i << 2)));
 217             }
 218             ND_PRINT(" }");
 219         } else
 220             ND_PRINT(", %u source(s)", nsrcs);
 221     }
 222     ND_PRINT("]");
 223 }
 224
 225 void
 226 igmp_print(netdissect_options *ndo,
 227            const u_char *bp, u_int len)
 228 {
 229     struct cksum_vec vec[1];
 230
 231     ndo->ndo_protocol = "igmp";
 232     if (ndo->ndo_qflag) {
 233         ND_PRINT("igmp");
 234         return;
 235     }
 236
 237     switch (GET_U_1(bp)) {
 238     case 0x11:
 239         ND_PRINT("igmp query");
 240         if (len >= 12)
 241             print_igmpv3_query(ndo, bp, len);
 242         else {
 243             if (GET_U_1(bp + 1)) {
 244                 ND_PRINT(" v2");
 245                 if (GET_U_1(bp + 1) != 100)
 246                     ND_PRINT(" [max resp time %u]", GET_U_1(bp + 1));
 247             } else
 248                 ND_PRINT(" v1");
 249             if (GET_BE_U_4(bp + 4))
 250                 ND_PRINT(" [gaddr %s]", GET_IPADDR_STRING(bp + 4));
 251             if (len != 8)
 252                 ND_PRINT(" [len %u]", len);
 253         }
 254         break;
 255     case 0x12:
 256         ND_PRINT("igmp v1 report %s", GET_IPADDR_STRING(bp + 4));
 257         if (len != 8)
 258             ND_PRINT(" [len %u]", len);
 259         break;
 260     case 0x16:
 261         ND_PRINT("igmp v2 report %s", GET_IPADDR_STRING(bp + 4));
 262         break;
 263     case 0x22:
 264         ND_PRINT("igmp v3 report");
 265         print_igmpv3_report(ndo, bp, len);
 266         break;
 267     case 0x17:
 268         ND_PRINT("igmp leave %s", GET_IPADDR_STRING(bp + 4));
 269         break;
 270     case 0x13:
 271         ND_PRINT("igmp dvmrp");
 272         if (len < 8)
 273             ND_PRINT(" [len %u]", len);
 274         else
 275             dvmrp_print(ndo, bp, len);
 276         break;
 277     case 0x14:
 278         ND_PRINT("igmp pimv1");
 279         pimv1_print(ndo, bp, len);
 280         break;
 281     case 0x1e:
 282         print_mtrace(ndo, "mresp", bp, len);
 283         break;
 284     case 0x1f:
 285         print_mtrace(ndo, "mtrace", bp, len);
 286         break;
 287     default:
 288         ND_PRINT("igmp-%u", GET_U_1(bp));
 289         break;
 290     }
 291
 292     if (ndo->ndo_vflag && len >= 4 && ND_TTEST_LEN(bp, len)) {
 293         /* Check the IGMP checksum */
 294         vec[0].ptr = bp;
 295         vec[0].len = len;
 296         if (in_cksum(vec, 1))
 297             ND_PRINT(" bad igmp cksum %x!", GET_BE_U_2(bp + 2));
 298     }
 299 }