contrib/tcpdump/print-icmp.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  * $FreeBSD$
  22  */
  23
  24 #define NETDISSECT_REWORKED
  25 #ifdef HAVE_CONFIG_H
  26 #include "config.h"
  27 #endif
  28
  29 #include <tcpdump-stdinc.h>
  30
  31 #include <stdio.h>
  32 #include <string.h>
  33
  34 #include "interface.h"
  35 #include "addrtoname.h"
  36 #include "extract.h"                    /* must come after interface.h */
  37
  38 #include "ip.h"
  39 #include "udp.h"
  40 #include "ipproto.h"
  41 #include "mpls.h"
  42
  43 /*
  44  * Interface Control Message Protocol Definitions.
  45  * Per RFC 792, September 1981.
  46  */
  47
  48 /*
  49  * Structure of an icmp header.
  50  */
  51 struct icmp {
  52         uint8_t  icmp_type;             /* type of message, see below */
  53         uint8_t  icmp_code;             /* type sub code */
  54         uint16_t icmp_cksum;            /* ones complement cksum of struct */
  55         union {
  56                 uint8_t ih_pptr;                        /* ICMP_PARAMPROB */
  57                 struct in_addr ih_gwaddr;       /* ICMP_REDIRECT */
  58                 struct ih_idseq {
  59                         uint16_t icd_id;
  60                         uint16_t icd_seq;
  61                 } ih_idseq;
  62                 uint32_t ih_void;
  63         } icmp_hun;
  64 #define icmp_pptr       icmp_hun.ih_pptr
  65 #define icmp_gwaddr     icmp_hun.ih_gwaddr
  66 #define icmp_id         icmp_hun.ih_idseq.icd_id
  67 #define icmp_seq        icmp_hun.ih_idseq.icd_seq
  68 #define icmp_void       icmp_hun.ih_void
  69         union {
  70                 struct id_ts {
  71                         uint32_t its_otime;
  72                         uint32_t its_rtime;
  73                         uint32_t its_ttime;
  74                 } id_ts;
  75                 struct id_ip  {
  76                         struct ip idi_ip;
  77                         /* options and then 64 bits of data */
  78                 } id_ip;
  79                 uint32_t id_mask;
  80                 uint8_t id_data[1];
  81         } icmp_dun;
  82 #define icmp_otime      icmp_dun.id_ts.its_otime
  83 #define icmp_rtime      icmp_dun.id_ts.its_rtime
  84 #define icmp_ttime      icmp_dun.id_ts.its_ttime
  85 #define icmp_ip         icmp_dun.id_ip.idi_ip
  86 #define icmp_mask       icmp_dun.id_mask
  87 #define icmp_data       icmp_dun.id_data
  88 };
  89
  90 #define ICMP_MPLS_EXT_EXTRACT_VERSION(x) (((x)&0xf0)>>4)
  91 #define ICMP_MPLS_EXT_VERSION 2
  92
  93 /*
  94  * Lower bounds on packet lengths for various types.
  95  * For the error advice packets must first insure that the
  96  * packet is large enought to contain the returned ip header.
  97  * Only then can we do the check to see if 64 bits of packet
  98  * data have been returned, since we need to check the returned
  99  * ip header length.
 100  */
 101 #define ICMP_MINLEN     8                               /* abs minimum */
 102 #define ICMP_EXTD_MINLEN (156 - sizeof (struct ip))     /* draft-bonica-internet-icmp-08 */
 103 #define ICMP_TSLEN      (8 + 3 * sizeof (uint32_t))     /* timestamp */
 104 #define ICMP_MASKLEN    12                              /* address mask */
 105 #define ICMP_ADVLENMIN  (8 + sizeof (struct ip) + 8)    /* min */
 106 #define ICMP_ADVLEN(p)  (8 + (IP_HL(&(p)->icmp_ip) << 2) + 8)
 107         /* N.B.: must separately check that ip_hl >= 5 */
 108
 109 /*
 110  * Definition of type and code field values.
 111  */
 112 #define ICMP_ECHOREPLY          0               /* echo reply */
 113 #define ICMP_UNREACH            3               /* dest unreachable, codes: */
 114 #define         ICMP_UNREACH_NET        0               /* bad net */
 115 #define         ICMP_UNREACH_HOST       1               /* bad host */
 116 #define         ICMP_UNREACH_PROTOCOL   2               /* bad protocol */
 117 #define         ICMP_UNREACH_PORT       3               /* bad port */
 118 #define         ICMP_UNREACH_NEEDFRAG   4               /* IP_DF caused drop */
 119 #define         ICMP_UNREACH_SRCFAIL    5               /* src route failed */
 120 #define         ICMP_UNREACH_NET_UNKNOWN 6              /* unknown net */
 121 #define         ICMP_UNREACH_HOST_UNKNOWN 7             /* unknown host */
 122 #define         ICMP_UNREACH_ISOLATED   8               /* src host isolated */
 123 #define         ICMP_UNREACH_NET_PROHIB 9               /* prohibited access */
 124 #define         ICMP_UNREACH_HOST_PROHIB 10             /* ditto */
 125 #define         ICMP_UNREACH_TOSNET     11              /* bad tos for net */
 126 #define         ICMP_UNREACH_TOSHOST    12              /* bad tos for host */
 127 #define ICMP_SOURCEQUENCH       4               /* packet lost, slow down */
 128 #define ICMP_REDIRECT           5               /* shorter route, codes: */
 129 #define         ICMP_REDIRECT_NET       0               /* for network */
 130 #define         ICMP_REDIRECT_HOST      1               /* for host */
 131 #define         ICMP_REDIRECT_TOSNET    2               /* for tos and net */
 132 #define         ICMP_REDIRECT_TOSHOST   3               /* for tos and host */
 133 #define ICMP_ECHO               8               /* echo service */
 134 #define ICMP_ROUTERADVERT       9               /* router advertisement */
 135 #define ICMP_ROUTERSOLICIT      10              /* router solicitation */
 136 #define ICMP_TIMXCEED           11              /* time exceeded, code: */
 137 #define         ICMP_TIMXCEED_INTRANS   0               /* ttl==0 in transit */
 138 #define         ICMP_TIMXCEED_REASS     1               /* ttl==0 in reass */
 139 #define ICMP_PARAMPROB          12              /* ip header bad */
 140 #define         ICMP_PARAMPROB_OPTABSENT 1              /* req. opt. absent */
 141 #define ICMP_TSTAMP             13              /* timestamp request */
 142 #define ICMP_TSTAMPREPLY        14              /* timestamp reply */
 143 #define ICMP_IREQ               15              /* information request */
 144 #define ICMP_IREQREPLY          16              /* information reply */
 145 #define ICMP_MASKREQ            17              /* address mask request */
 146 #define ICMP_MASKREPLY          18              /* address mask reply */
 147
 148 #define ICMP_MAXTYPE            18
 149
 150 #define ICMP_ERRTYPE(type) \
 151         ((type) == ICMP_UNREACH || (type) == ICMP_SOURCEQUENCH || \
 152         (type) == ICMP_REDIRECT || (type) == ICMP_TIMXCEED || \
 153         (type) == ICMP_PARAMPROB)
 154 #define ICMP_MPLS_EXT_TYPE(type) \
 155         ((type) == ICMP_UNREACH || \
 156          (type) == ICMP_TIMXCEED || \
 157          (type) == ICMP_PARAMPROB)
 158 /* rfc1700 */
 159 #ifndef ICMP_UNREACH_NET_UNKNOWN
 160 #define ICMP_UNREACH_NET_UNKNOWN        6       /* destination net unknown */
 161 #endif
 162 #ifndef ICMP_UNREACH_HOST_UNKNOWN
 163 #define ICMP_UNREACH_HOST_UNKNOWN       7       /* destination host unknown */
 164 #endif
 165 #ifndef ICMP_UNREACH_ISOLATED
 166 #define ICMP_UNREACH_ISOLATED           8       /* source host isolated */
 167 #endif
 168 #ifndef ICMP_UNREACH_NET_PROHIB
 169 #define ICMP_UNREACH_NET_PROHIB         9       /* admin prohibited net */
 170 #endif
 171 #ifndef ICMP_UNREACH_HOST_PROHIB
 172 #define ICMP_UNREACH_HOST_PROHIB        10      /* admin prohibited host */
 173 #endif
 174 #ifndef ICMP_UNREACH_TOSNET
 175 #define ICMP_UNREACH_TOSNET             11      /* tos prohibited net */
 176 #endif
 177 #ifndef ICMP_UNREACH_TOSHOST
 178 #define ICMP_UNREACH_TOSHOST            12      /* tos prohibited host */
 179 #endif
 180
 181 /* rfc1716 */
 182 #ifndef ICMP_UNREACH_FILTER_PROHIB
 183 #define ICMP_UNREACH_FILTER_PROHIB      13      /* admin prohibited filter */
 184 #endif
 185 #ifndef ICMP_UNREACH_HOST_PRECEDENCE
 186 #define ICMP_UNREACH_HOST_PRECEDENCE    14      /* host precedence violation */
 187 #endif
 188 #ifndef ICMP_UNREACH_PRECEDENCE_CUTOFF
 189 #define ICMP_UNREACH_PRECEDENCE_CUTOFF  15      /* precedence cutoff */
 190 #endif
 191
 192 /* Most of the icmp types */
 193 static const struct tok icmp2str[] = {
 194         { ICMP_ECHOREPLY,               "echo reply" },
 195         { ICMP_SOURCEQUENCH,            "source quench" },
 196         { ICMP_ECHO,                    "echo request" },
 197         { ICMP_ROUTERSOLICIT,           "router solicitation" },
 198         { ICMP_TSTAMP,                  "time stamp request" },
 199         { ICMP_TSTAMPREPLY,             "time stamp reply" },
 200         { ICMP_IREQ,                    "information request" },
 201         { ICMP_IREQREPLY,               "information reply" },
 202         { ICMP_MASKREQ,                 "address mask request" },
 203         { 0,                            NULL }
 204 };
 205
 206 /* Formats for most of the ICMP_UNREACH codes */
 207 static const struct tok unreach2str[] = {
 208         { ICMP_UNREACH_NET,             "net %s unreachable" },
 209         { ICMP_UNREACH_HOST,            "host %s unreachable" },
 210         { ICMP_UNREACH_SRCFAIL,
 211             "%s unreachable - source route failed" },
 212         { ICMP_UNREACH_NET_UNKNOWN,     "net %s unreachable - unknown" },
 213         { ICMP_UNREACH_HOST_UNKNOWN,    "host %s unreachable - unknown" },
 214         { ICMP_UNREACH_ISOLATED,
 215             "%s unreachable - source host isolated" },
 216         { ICMP_UNREACH_NET_PROHIB,
 217             "net %s unreachable - admin prohibited" },
 218         { ICMP_UNREACH_HOST_PROHIB,
 219             "host %s unreachable - admin prohibited" },
 220         { ICMP_UNREACH_TOSNET,
 221             "net %s unreachable - tos prohibited" },
 222         { ICMP_UNREACH_TOSHOST,
 223             "host %s unreachable - tos prohibited" },
 224         { ICMP_UNREACH_FILTER_PROHIB,
 225             "host %s unreachable - admin prohibited filter" },
 226         { ICMP_UNREACH_HOST_PRECEDENCE,
 227             "host %s unreachable - host precedence violation" },
 228         { ICMP_UNREACH_PRECEDENCE_CUTOFF,
 229             "host %s unreachable - precedence cutoff" },
 230         { 0,                            NULL }
 231 };
 232
 233 /* Formats for the ICMP_REDIRECT codes */
 234 static const struct tok type2str[] = {
 235         { ICMP_REDIRECT_NET,            "redirect %s to net %s" },
 236         { ICMP_REDIRECT_HOST,           "redirect %s to host %s" },
 237         { ICMP_REDIRECT_TOSNET,         "redirect-tos %s to net %s" },
 238         { ICMP_REDIRECT_TOSHOST,        "redirect-tos %s to host %s" },
 239         { 0,                            NULL }
 240 };
 241
 242 /* rfc1191 */
 243 struct mtu_discovery {
 244         uint16_t unused;
 245         uint16_t nexthopmtu;
 246 };
 247
 248 /* rfc1256 */
 249 struct ih_rdiscovery {
 250         uint8_t ird_addrnum;
 251         uint8_t ird_addrsiz;
 252         uint16_t ird_lifetime;
 253 };
 254
 255 struct id_rdiscovery {
 256         uint32_t ird_addr;
 257         uint32_t ird_pref;
 258 };
 259
 260 /*
 261  * draft-bonica-internet-icmp-08
 262  *
 263  * The Destination Unreachable, Time Exceeded
 264  * and Parameter Problem messages are slighly changed as per
 265  * the above draft. A new Length field gets added to give
 266  * the caller an idea about the length of the piggypacked
 267  * IP packet before the MPLS extension header starts.
 268  *
 269  * The Length field represents length of the padded "original datagram"
 270  * field  measured in 32-bit words.
 271  *
 272  * 0                   1                   2                   3
 273  * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 274  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 275  * |     Type      |     Code      |          Checksum             |
 276  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 277  * |     unused    |    Length     |          unused               |
 278  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 279  * |      Internet Header + leading octets of original datagram    |
 280  * |                                                               |
 281  * |                           //                                  |
 282  * |                                                               |
 283  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 284  */
 285
 286 struct icmp_ext_t {
 287     uint8_t icmp_type;
 288     uint8_t icmp_code;
 289     uint8_t icmp_checksum[2];
 290     uint8_t icmp_reserved;
 291     uint8_t icmp_length;
 292     uint8_t icmp_reserved2[2];
 293     uint8_t icmp_ext_legacy_header[128]; /* extension header starts 128 bytes after ICMP header */
 294     uint8_t icmp_ext_version_res[2];
 295     uint8_t icmp_ext_checksum[2];
 296     uint8_t icmp_ext_data[1];
 297 };
 298
 299 struct icmp_mpls_ext_object_header_t {
 300     uint8_t length[2];
 301     uint8_t class_num;
 302     uint8_t ctype;
 303 };
 304
 305 static const struct tok icmp_mpls_ext_obj_values[] = {
 306     { 1, "MPLS Stack Entry" },
 307     { 2, "Extended Payload" },
 308     { 0, NULL}
 309 };
 310
 311 /* prototypes */
 312 const char *icmp_tstamp_print(u_int);
 313
 314 /* print the milliseconds since midnight UTC */
 315 const char *
 316 icmp_tstamp_print(u_int tstamp)
 317 {
 318     u_int msec,sec,min,hrs;
 319
 320     static char buf[64];
 321
 322     msec = tstamp % 1000;
 323     sec = tstamp / 1000;
 324     min = sec / 60; sec -= min * 60;
 325     hrs = min / 60; min -= hrs * 60;
 326     snprintf(buf, sizeof(buf), "%02u:%02u:%02u.%03u",hrs,min,sec,msec);
 327     return buf;
 328 }
 329
 330 void
 331 icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *bp2,
 332            int fragmented)
 333 {
 334         char *cp;
 335         const struct icmp *dp;
 336         const struct icmp_ext_t *ext_dp;
 337         const struct ip *ip;
 338         const char *str, *fmt;
 339         const struct ip *oip;
 340         const struct udphdr *ouh;
 341         const uint8_t *obj_tptr;
 342         uint32_t raw_label;
 343         const u_char *snapend_save;
 344         const struct icmp_mpls_ext_object_header_t *icmp_mpls_ext_object_header;
 345         u_int hlen, dport, mtu, obj_tlen, obj_class_num, obj_ctype;
 346         char buf[MAXHOSTNAMELEN + 100];
 347         struct cksum_vec vec[1];
 348
 349         dp = (struct icmp *)bp;
 350         ext_dp = (struct icmp_ext_t *)bp;
 351         ip = (struct ip *)bp2;
 352         str = buf;
 353
 354         ND_TCHECK(dp->icmp_code);
 355         switch (dp->icmp_type) {
 356
 357         case ICMP_ECHO:
 358         case ICMP_ECHOREPLY:
 359                 ND_TCHECK(dp->icmp_seq);
 360                 (void)snprintf(buf, sizeof(buf), "echo %s, id %u, seq %u",
 361                                dp->icmp_type == ICMP_ECHO ?
 362                                "request" : "reply",
 363                                EXTRACT_16BITS(&dp->icmp_id),
 364                                EXTRACT_16BITS(&dp->icmp_seq));
 365                 break;
 366
 367         case ICMP_UNREACH:
 368                 ND_TCHECK(dp->icmp_ip.ip_dst);
 369                 switch (dp->icmp_code) {
 370
 371                 case ICMP_UNREACH_PROTOCOL:
 372                         ND_TCHECK(dp->icmp_ip.ip_p);
 373                         (void)snprintf(buf, sizeof(buf),
 374                             "%s protocol %d unreachable",
 375                             ipaddr_string(ndo, &dp->icmp_ip.ip_dst),
 376                             dp->icmp_ip.ip_p);
 377                         break;
 378
 379                 case ICMP_UNREACH_PORT:
 380                         ND_TCHECK(dp->icmp_ip.ip_p);
 381                         oip = &dp->icmp_ip;
 382                         hlen = IP_HL(oip) * 4;
 383                         ouh = (struct udphdr *)(((u_char *)oip) + hlen);
 384                         ND_TCHECK(ouh->uh_dport);
 385                         dport = EXTRACT_16BITS(&ouh->uh_dport);
 386                         switch (oip->ip_p) {
 387
 388                         case IPPROTO_TCP:
 389                                 (void)snprintf(buf, sizeof(buf),
 390                                         "%s tcp port %s unreachable",
 391                                         ipaddr_string(ndo, &oip->ip_dst),
 392                                         tcpport_string(dport));
 393                                 break;
 394
 395                         case IPPROTO_UDP:
 396                                 (void)snprintf(buf, sizeof(buf),
 397                                         "%s udp port %s unreachable",
 398                                         ipaddr_string(ndo, &oip->ip_dst),
 399                                         udpport_string(dport));
 400                                 break;
 401
 402                         default:
 403                                 (void)snprintf(buf, sizeof(buf),
 404                                         "%s protocol %d port %d unreachable",
 405                                         ipaddr_string(ndo, &oip->ip_dst),
 406                                         oip->ip_p, dport);
 407                                 break;
 408                         }
 409                         break;
 410
 411                 case ICMP_UNREACH_NEEDFRAG:
 412                     {
 413                         register const struct mtu_discovery *mp;
 414                         mp = (struct mtu_discovery *)(u_char *)&dp->icmp_void;
 415                         mtu = EXTRACT_16BITS(&mp->nexthopmtu);
 416                         if (mtu) {
 417                                 (void)snprintf(buf, sizeof(buf),
 418                                     "%s unreachable - need to frag (mtu %d)",
 419                                     ipaddr_string(ndo, &dp->icmp_ip.ip_dst), mtu);
 420                         } else {
 421                                 (void)snprintf(buf, sizeof(buf),
 422                                     "%s unreachable - need to frag",
 423                                     ipaddr_string(ndo, &dp->icmp_ip.ip_dst));
 424                         }
 425                     }
 426                         break;
 427
 428                 default:
 429                         fmt = tok2str(unreach2str, "#%d %%s unreachable",
 430                             dp->icmp_code);
 431                         (void)snprintf(buf, sizeof(buf), fmt,
 432                             ipaddr_string(ndo, &dp->icmp_ip.ip_dst));
 433                         break;
 434                 }
 435                 break;
 436
 437         case ICMP_REDIRECT:
 438                 ND_TCHECK(dp->icmp_ip.ip_dst);
 439                 fmt = tok2str(type2str, "redirect-#%d %%s to net %%s",
 440                     dp->icmp_code);
 441                 (void)snprintf(buf, sizeof(buf), fmt,
 442                     ipaddr_string(ndo, &dp->icmp_ip.ip_dst),
 443                     ipaddr_string(ndo, &dp->icmp_gwaddr));
 444                 break;
 445
 446         case ICMP_ROUTERADVERT:
 447             {
 448                 register const struct ih_rdiscovery *ihp;
 449                 register const struct id_rdiscovery *idp;
 450                 u_int lifetime, num, size;
 451
 452                 (void)snprintf(buf, sizeof(buf), "router advertisement");
 453                 cp = buf + strlen(buf);
 454
 455                 ihp = (struct ih_rdiscovery *)&dp->icmp_void;
 456                 ND_TCHECK(*ihp);
 457                 (void)strncpy(cp, " lifetime ", sizeof(buf) - (cp - buf));
 458                 cp = buf + strlen(buf);
 459                 lifetime = EXTRACT_16BITS(&ihp->ird_lifetime);
 460                 if (lifetime < 60) {
 461                         (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u",
 462                             lifetime);
 463                 } else if (lifetime < 60 * 60) {
 464                         (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u:%02u",
 465                             lifetime / 60, lifetime % 60);
 466                 } else {
 467                         (void)snprintf(cp, sizeof(buf) - (cp - buf),
 468                             "%u:%02u:%02u",
 469                             lifetime / 3600,
 470                             (lifetime % 3600) / 60,
 471                             lifetime % 60);
 472                 }
 473                 cp = buf + strlen(buf);
 474
 475                 num = ihp->ird_addrnum;
 476                 (void)snprintf(cp, sizeof(buf) - (cp - buf), " %d:", num);
 477                 cp = buf + strlen(buf);
 478
 479                 size = ihp->ird_addrsiz;
 480                 if (size != 2) {
 481                         (void)snprintf(cp, sizeof(buf) - (cp - buf),
 482                             " [size %d]", size);
 483                         break;
 484                 }
 485                 idp = (struct id_rdiscovery *)&dp->icmp_data;
 486                 while (num-- > 0) {
 487                         ND_TCHECK(*idp);
 488                         (void)snprintf(cp, sizeof(buf) - (cp - buf), " {%s %u}",
 489                             ipaddr_string(ndo, &idp->ird_addr),
 490                             EXTRACT_32BITS(&idp->ird_pref));
 491                         cp = buf + strlen(buf);
 492                         ++idp;
 493                 }
 494             }
 495                 break;
 496
 497         case ICMP_TIMXCEED:
 498                 ND_TCHECK(dp->icmp_ip.ip_dst);
 499                 switch (dp->icmp_code) {
 500
 501                 case ICMP_TIMXCEED_INTRANS:
 502                         str = "time exceeded in-transit";
 503                         break;
 504
 505                 case ICMP_TIMXCEED_REASS:
 506                         str = "ip reassembly time exceeded";
 507                         break;
 508
 509                 default:
 510                         (void)snprintf(buf, sizeof(buf), "time exceeded-#%d",
 511                             dp->icmp_code);
 512                         break;
 513                 }
 514                 break;
 515
 516         case ICMP_PARAMPROB:
 517                 if (dp->icmp_code)
 518                         (void)snprintf(buf, sizeof(buf),
 519                             "parameter problem - code %d", dp->icmp_code);
 520                 else {
 521                         ND_TCHECK(dp->icmp_pptr);
 522                         (void)snprintf(buf, sizeof(buf),
 523                             "parameter problem - octet %d", dp->icmp_pptr);
 524                 }
 525                 break;
 526
 527         case ICMP_MASKREPLY:
 528                 ND_TCHECK(dp->icmp_mask);
 529                 (void)snprintf(buf, sizeof(buf), "address mask is 0x%08x",
 530                     EXTRACT_32BITS(&dp->icmp_mask));
 531                 break;
 532
 533         case ICMP_TSTAMP:
 534                 ND_TCHECK(dp->icmp_seq);
 535                 (void)snprintf(buf, sizeof(buf),
 536                     "time stamp query id %u seq %u",
 537                     EXTRACT_16BITS(&dp->icmp_id),
 538                     EXTRACT_16BITS(&dp->icmp_seq));
 539                 break;
 540
 541         case ICMP_TSTAMPREPLY:
 542                 ND_TCHECK(dp->icmp_ttime);
 543                 (void)snprintf(buf, sizeof(buf),
 544                     "time stamp reply id %u seq %u: org %s",
 545                                EXTRACT_16BITS(&dp->icmp_id),
 546                                EXTRACT_16BITS(&dp->icmp_seq),
 547                                icmp_tstamp_print(EXTRACT_32BITS(&dp->icmp_otime)));
 548
 549                 (void)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", recv %s",
 550                          icmp_tstamp_print(EXTRACT_32BITS(&dp->icmp_rtime)));
 551                 (void)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", xmit %s",
 552                          icmp_tstamp_print(EXTRACT_32BITS(&dp->icmp_ttime)));
 553                 break;
 554
 555         default:
 556                 str = tok2str(icmp2str, "type-#%d", dp->icmp_type);
 557                 break;
 558         }
 559         ND_PRINT((ndo, "ICMP %s, length %u", str, plen));
 560         if (ndo->ndo_vflag && !fragmented) { /* don't attempt checksumming if this is a frag */
 561                 uint16_t sum, icmp_sum;
 562                 struct cksum_vec vec[1];
 563                 if (ND_TTEST2(*bp, plen)) {
 564                         vec[0].ptr = (const uint8_t *)(void *)dp;
 565                         vec[0].len = plen;
 566                         sum = in_cksum(vec, 1);
 567                         if (sum != 0) {
 568                                 icmp_sum = EXTRACT_16BITS(&dp->icmp_cksum);
 569                                 ND_PRINT((ndo, " (wrong icmp cksum %x (->%x)!)",
 570                                              icmp_sum,
 571                                              in_cksum_shouldbe(icmp_sum, sum)));
 572                         }
 573                 }
 574         }
 575
 576         /*
 577          * print the remnants of the IP packet.
 578          * save the snaplength as this may get overidden in the IP printer.
 579          */
 580         if (ndo->ndo_vflag >= 1 && ICMP_ERRTYPE(dp->icmp_type)) {
 581                 bp += 8;
 582                 ND_PRINT((ndo, "\n\t"));
 583                 ip = (struct ip *)bp;
 584                 ndo->ndo_snaplen = ndo->ndo_snapend - bp;
 585                 snapend_save = ndo->ndo_snapend;
 586                 ip_print(ndo, bp, EXTRACT_16BITS(&ip->ip_len));
 587                 ndo->ndo_snapend = snapend_save;
 588         }
 589
 590         /*
 591          * Attempt to decode the MPLS extensions only for some ICMP types.
 592          */
 593         if (ndo->ndo_vflag >= 1 && plen > ICMP_EXTD_MINLEN && ICMP_MPLS_EXT_TYPE(dp->icmp_type)) {
 594
 595             ND_TCHECK(*ext_dp);
 596
 597             /*
 598              * Check first if the mpls extension header shows a non-zero length.
 599              * If the length field is not set then silently verify the checksum
 600              * to check if an extension header is present. This is expedient,
 601              * however not all implementations set the length field proper.
 602              */
 603             if (!ext_dp->icmp_length) {
 604                 vec[0].ptr = (const uint8_t *)(void *)&ext_dp->icmp_ext_version_res;
 605                 vec[0].len = plen - ICMP_EXTD_MINLEN;
 606                 if (in_cksum(vec, 1)) {
 607                     return;
 608                 }
 609             }
 610
 611             ND_PRINT((ndo, "\n\tMPLS extension v%u",
 612                    ICMP_MPLS_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res))));
 613
 614             /*
 615              * Sanity checking of the header.
 616              */
 617             if (ICMP_MPLS_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res)) !=
 618                 ICMP_MPLS_EXT_VERSION) {
 619                 ND_PRINT((ndo, " packet not supported"));
 620                 return;
 621             }
 622
 623             hlen = plen - ICMP_EXTD_MINLEN;
 624             vec[0].ptr = (const uint8_t *)(void *)&ext_dp->icmp_ext_version_res;
 625             vec[0].len = hlen;
 626             ND_PRINT((ndo, ", checksum 0x%04x (%scorrect), length %u",
 627                    EXTRACT_16BITS(ext_dp->icmp_ext_checksum),
 628                    in_cksum(vec, 1) ? "in" : "",
 629                    hlen));
 630
 631             hlen -= 4; /* subtract common header size */
 632             obj_tptr = (uint8_t *)ext_dp->icmp_ext_data;
 633
 634             while (hlen > sizeof(struct icmp_mpls_ext_object_header_t)) {
 635
 636                 icmp_mpls_ext_object_header = (struct icmp_mpls_ext_object_header_t *)obj_tptr;
 637                 ND_TCHECK(*icmp_mpls_ext_object_header);
 638                 obj_tlen = EXTRACT_16BITS(icmp_mpls_ext_object_header->length);
 639                 obj_class_num = icmp_mpls_ext_object_header->class_num;
 640                 obj_ctype = icmp_mpls_ext_object_header->ctype;
 641                 obj_tptr += sizeof(struct icmp_mpls_ext_object_header_t);
 642
 643                 ND_PRINT((ndo, "\n\t  %s Object (%u), Class-Type: %u, length %u",
 644                        tok2str(icmp_mpls_ext_obj_values,"unknown",obj_class_num),
 645                        obj_class_num,
 646                        obj_ctype,
 647                        obj_tlen));
 648
 649                 hlen-=sizeof(struct icmp_mpls_ext_object_header_t); /* length field includes tlv header */
 650
 651                 /* infinite loop protection */
 652                 if ((obj_class_num == 0) ||
 653                     (obj_tlen < sizeof(struct icmp_mpls_ext_object_header_t))) {
 654                     return;
 655                 }
 656                 obj_tlen-=sizeof(struct icmp_mpls_ext_object_header_t);
 657
 658                 switch (obj_class_num) {
 659                 case 1:
 660                     switch(obj_ctype) {
 661                     case 1:
 662                         ND_TCHECK2(*obj_tptr, 4);
 663                         raw_label = EXTRACT_32BITS(obj_tptr);
 664                         ND_PRINT((ndo, "\n\t    label %u, exp %u", MPLS_LABEL(raw_label), MPLS_EXP(raw_label)));
 665                         if (MPLS_STACK(raw_label))
 666                             ND_PRINT((ndo, ", [S]"));
 667                         ND_PRINT((ndo, ", ttl %u", MPLS_TTL(raw_label)));
 668                         break;
 669                     default:
 670                         print_unknown_data(ndo, obj_tptr, "\n\t    ", obj_tlen);
 671                     }
 672                     break;
 673
 674                /*
 675                 *  FIXME those are the defined objects that lack a decoder
 676                 *  you are welcome to contribute code ;-)
 677                 */
 678                 case 2:
 679                 default:
 680                     print_unknown_data(ndo, obj_tptr, "\n\t    ", obj_tlen);
 681                     break;
 682                 }
 683                 if (hlen < obj_tlen)
 684                     break;
 685                 hlen -= obj_tlen;
 686                 obj_tptr += obj_tlen;
 687             }
 688         }
 689
 690         return;
 691 trunc:
 692         ND_PRINT((ndo, "[|icmp]"));
 693 }
 694 /*
 695  * Local Variables:
 696  * c-style: whitesmith
 697  * c-basic-offset: 8
 698  * End:
 699  */