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
  22 /* \summary: Internet Control Message Protocol (ICMP) printer */
  23
  24 #ifdef HAVE_CONFIG_H
  25 #include "config.h"
  26 #endif
  27
  28 #include <netdissect-stdinc.h>
  29
  30 #include <stdio.h>
  31 #include <string.h>
  32
  33 #include "netdissect.h"
  34 #include "addrtoname.h"
  35 #include "extract.h"
  36
  37 #include "ip.h"
  38 #include "udp.h"
  39 #include "ipproto.h"
  40 #include "mpls.h"
  41
  42 /*
  43  * Interface Control Message Protocol Definitions.
  44  * Per RFC 792, September 1981.
  45  */
  46
  47 /*
  48  * Structure of an icmp header.
  49  */
  50 struct icmp {
  51         uint8_t  icmp_type;             /* type of message, see below */
  52         uint8_t  icmp_code;             /* type sub code */
  53         uint16_t icmp_cksum;            /* ones complement cksum of struct */
  54         union {
  55                 uint8_t ih_pptr;                        /* ICMP_PARAMPROB */
  56                 struct in_addr ih_gwaddr;       /* ICMP_REDIRECT */
  57                 struct ih_idseq {
  58                         uint16_t icd_id;
  59                         uint16_t icd_seq;
  60                 } ih_idseq;
  61                 uint32_t ih_void;
  62         } icmp_hun;
  63 #define icmp_pptr       icmp_hun.ih_pptr
  64 #define icmp_gwaddr     icmp_hun.ih_gwaddr
  65 #define icmp_id         icmp_hun.ih_idseq.icd_id
  66 #define icmp_seq        icmp_hun.ih_idseq.icd_seq
  67 #define icmp_void       icmp_hun.ih_void
  68         union {
  69                 struct id_ts {
  70                         uint32_t its_otime;
  71                         uint32_t its_rtime;
  72                         uint32_t its_ttime;
  73                 } id_ts;
  74                 struct id_ip  {
  75                         struct ip idi_ip;
  76                         /* options and then 64 bits of data */
  77                 } id_ip;
  78                 uint32_t id_mask;
  79                 uint8_t id_data[1];
  80         } icmp_dun;
  81 #define icmp_otime      icmp_dun.id_ts.its_otime
  82 #define icmp_rtime      icmp_dun.id_ts.its_rtime
  83 #define icmp_ttime      icmp_dun.id_ts.its_ttime
  84 #define icmp_ip         icmp_dun.id_ip.idi_ip
  85 #define icmp_mask       icmp_dun.id_mask
  86 #define icmp_data       icmp_dun.id_data
  87 };
  88
  89 #define ICMP_MPLS_EXT_EXTRACT_VERSION(x) (((x)&0xf0)>>4)
  90 #define ICMP_MPLS_EXT_VERSION 2
  91
  92 /*
  93  * Lower bounds on packet lengths for various types.
  94  * For the error advice packets must first insure that the
  95  * packet is large enought to contain the returned ip header.
  96  * Only then can we do the check to see if 64 bits of packet
  97  * data have been returned, since we need to check the returned
  98  * ip header length.
  99  */
 100 #define ICMP_MINLEN     8                               /* abs minimum */
 101 #define ICMP_EXTD_MINLEN (156 - sizeof (struct ip))     /* draft-bonica-internet-icmp-08 */
 102 #define ICMP_TSLEN      (8 + 3 * sizeof (uint32_t))     /* timestamp */
 103 #define ICMP_MASKLEN    12                              /* address mask */
 104 #define ICMP_ADVLENMIN  (8 + sizeof (struct ip) + 8)    /* min */
 105 #define ICMP_ADVLEN(p)  (8 + (IP_HL(&(p)->icmp_ip) << 2) + 8)
 106         /* N.B.: must separately check that ip_hl >= 5 */
 107
 108 /*
 109  * Definition of type and code field values.
 110  */
 111 #define ICMP_ECHOREPLY          0               /* echo reply */
 112 #define ICMP_UNREACH            3               /* dest unreachable, codes: */
 113 #define         ICMP_UNREACH_NET        0               /* bad net */
 114 #define         ICMP_UNREACH_HOST       1               /* bad host */
 115 #define         ICMP_UNREACH_PROTOCOL   2               /* bad protocol */
 116 #define         ICMP_UNREACH_PORT       3               /* bad port */
 117 #define         ICMP_UNREACH_NEEDFRAG   4               /* IP_DF caused drop */
 118 #define         ICMP_UNREACH_SRCFAIL    5               /* src route failed */
 119 #define         ICMP_UNREACH_NET_UNKNOWN 6              /* unknown net */
 120 #define         ICMP_UNREACH_HOST_UNKNOWN 7             /* unknown host */
 121 #define         ICMP_UNREACH_ISOLATED   8               /* src host isolated */
 122 #define         ICMP_UNREACH_NET_PROHIB 9               /* prohibited access */
 123 #define         ICMP_UNREACH_HOST_PROHIB 10             /* ditto */
 124 #define         ICMP_UNREACH_TOSNET     11              /* bad tos for net */
 125 #define         ICMP_UNREACH_TOSHOST    12              /* bad tos for host */
 126 #define ICMP_SOURCEQUENCH       4               /* packet lost, slow down */
 127 #define ICMP_REDIRECT           5               /* shorter route, codes: */
 128 #define         ICMP_REDIRECT_NET       0               /* for network */
 129 #define         ICMP_REDIRECT_HOST      1               /* for host */
 130 #define         ICMP_REDIRECT_TOSNET    2               /* for tos and net */
 131 #define         ICMP_REDIRECT_TOSHOST   3               /* for tos and host */
 132 #define ICMP_ECHO               8               /* echo service */
 133 #define ICMP_ROUTERADVERT       9               /* router advertisement */
 134 #define ICMP_ROUTERSOLICIT      10              /* router solicitation */
 135 #define ICMP_TIMXCEED           11              /* time exceeded, code: */
 136 #define         ICMP_TIMXCEED_INTRANS   0               /* ttl==0 in transit */
 137 #define         ICMP_TIMXCEED_REASS     1               /* ttl==0 in reass */
 138 #define ICMP_PARAMPROB          12              /* ip header bad */
 139 #define         ICMP_PARAMPROB_OPTABSENT 1              /* req. opt. absent */
 140 #define ICMP_TSTAMP             13              /* timestamp request */
 141 #define ICMP_TSTAMPREPLY        14              /* timestamp reply */
 142 #define ICMP_IREQ               15              /* information request */
 143 #define ICMP_IREQREPLY          16              /* information reply */
 144 #define ICMP_MASKREQ            17              /* address mask request */
 145 #define ICMP_MASKREPLY          18              /* address mask reply */
 146
 147 #define ICMP_MAXTYPE            18
 148
 149 #define ICMP_ERRTYPE(type) \
 150         ((type) == ICMP_UNREACH || (type) == ICMP_SOURCEQUENCH || \
 151         (type) == ICMP_REDIRECT || (type) == ICMP_TIMXCEED || \
 152         (type) == ICMP_PARAMPROB)
 153 #define ICMP_MPLS_EXT_TYPE(type) \
 154         ((type) == ICMP_UNREACH || \
 155          (type) == ICMP_TIMXCEED || \
 156          (type) == ICMP_PARAMPROB)
 157 /* rfc1700 */
 158 #ifndef ICMP_UNREACH_NET_UNKNOWN
 159 #define ICMP_UNREACH_NET_UNKNOWN        6       /* destination net unknown */
 160 #endif
 161 #ifndef ICMP_UNREACH_HOST_UNKNOWN
 162 #define ICMP_UNREACH_HOST_UNKNOWN       7       /* destination host unknown */
 163 #endif
 164 #ifndef ICMP_UNREACH_ISOLATED
 165 #define ICMP_UNREACH_ISOLATED           8       /* source host isolated */
 166 #endif
 167 #ifndef ICMP_UNREACH_NET_PROHIB
 168 #define ICMP_UNREACH_NET_PROHIB         9       /* admin prohibited net */
 169 #endif
 170 #ifndef ICMP_UNREACH_HOST_PROHIB
 171 #define ICMP_UNREACH_HOST_PROHIB        10      /* admin prohibited host */
 172 #endif
 173 #ifndef ICMP_UNREACH_TOSNET
 174 #define ICMP_UNREACH_TOSNET             11      /* tos prohibited net */
 175 #endif
 176 #ifndef ICMP_UNREACH_TOSHOST
 177 #define ICMP_UNREACH_TOSHOST            12      /* tos prohibited host */
 178 #endif
 179
 180 /* rfc1716 */
 181 #ifndef ICMP_UNREACH_FILTER_PROHIB
 182 #define ICMP_UNREACH_FILTER_PROHIB      13      /* admin prohibited filter */
 183 #endif
 184 #ifndef ICMP_UNREACH_HOST_PRECEDENCE
 185 #define ICMP_UNREACH_HOST_PRECEDENCE    14      /* host precedence violation */
 186 #endif
 187 #ifndef ICMP_UNREACH_PRECEDENCE_CUTOFF
 188 #define ICMP_UNREACH_PRECEDENCE_CUTOFF  15      /* precedence cutoff */
 189 #endif
 190
 191 /* Most of the icmp types */
 192 static const struct tok icmp2str[] = {
 193         { ICMP_ECHOREPLY,               "echo reply" },
 194         { ICMP_SOURCEQUENCH,            "source quench" },
 195         { ICMP_ECHO,                    "echo request" },
 196         { ICMP_ROUTERSOLICIT,           "router solicitation" },
 197         { ICMP_TSTAMP,                  "time stamp request" },
 198         { ICMP_TSTAMPREPLY,             "time stamp reply" },
 199         { ICMP_IREQ,                    "information request" },
 200         { ICMP_IREQREPLY,               "information reply" },
 201         { ICMP_MASKREQ,                 "address mask request" },
 202         { 0,                            NULL }
 203 };
 204
 205 /* Formats for most of the ICMP_UNREACH codes */
 206 static const struct tok unreach2str[] = {
 207         { ICMP_UNREACH_NET,             "net %s unreachable" },
 208         { ICMP_UNREACH_HOST,            "host %s unreachable" },
 209         { ICMP_UNREACH_SRCFAIL,
 210             "%s unreachable - source route failed" },
 211         { ICMP_UNREACH_NET_UNKNOWN,     "net %s unreachable - unknown" },
 212         { ICMP_UNREACH_HOST_UNKNOWN,    "host %s unreachable - unknown" },
 213         { ICMP_UNREACH_ISOLATED,
 214             "%s unreachable - source host isolated" },
 215         { ICMP_UNREACH_NET_PROHIB,
 216             "net %s unreachable - admin prohibited" },
 217         { ICMP_UNREACH_HOST_PROHIB,
 218             "host %s unreachable - admin prohibited" },
 219         { ICMP_UNREACH_TOSNET,
 220             "net %s unreachable - tos prohibited" },
 221         { ICMP_UNREACH_TOSHOST,
 222             "host %s unreachable - tos prohibited" },
 223         { ICMP_UNREACH_FILTER_PROHIB,
 224             "host %s unreachable - admin prohibited filter" },
 225         { ICMP_UNREACH_HOST_PRECEDENCE,
 226             "host %s unreachable - host precedence violation" },
 227         { ICMP_UNREACH_PRECEDENCE_CUTOFF,
 228             "host %s unreachable - precedence cutoff" },
 229         { 0,                            NULL }
 230 };
 231
 232 /* Formats for the ICMP_REDIRECT codes */
 233 static const struct tok type2str[] = {
 234         { ICMP_REDIRECT_NET,            "redirect %s to net %s" },
 235         { ICMP_REDIRECT_HOST,           "redirect %s to host %s" },
 236         { ICMP_REDIRECT_TOSNET,         "redirect-tos %s to net %s" },
 237         { ICMP_REDIRECT_TOSHOST,        "redirect-tos %s to host %s" },
 238         { 0,                            NULL }
 239 };
 240
 241 /* rfc1191 */
 242 struct mtu_discovery {
 243         uint16_t unused;
 244         uint16_t nexthopmtu;
 245 };
 246
 247 /* rfc1256 */
 248 struct ih_rdiscovery {
 249         uint8_t ird_addrnum;
 250         uint8_t ird_addrsiz;
 251         uint16_t ird_lifetime;
 252 };
 253
 254 struct id_rdiscovery {
 255         uint32_t ird_addr;
 256         uint32_t ird_pref;
 257 };
 258
 259 /*
 260  * draft-bonica-internet-icmp-08
 261  *
 262  * The Destination Unreachable, Time Exceeded
 263  * and Parameter Problem messages are slighly changed as per
 264  * the above draft. A new Length field gets added to give
 265  * the caller an idea about the length of the piggypacked
 266  * IP packet before the MPLS extension header starts.
 267  *
 268  * The Length field represents length of the padded "original datagram"
 269  * field  measured in 32-bit words.
 270  *
 271  * 0                   1                   2                   3
 272  * 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
 273  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 274  * |     Type      |     Code      |          Checksum             |
 275  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 276  * |     unused    |    Length     |          unused               |
 277  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 278  * |      Internet Header + leading octets of original datagram    |
 279  * |                                                               |
 280  * |                           //                                  |
 281  * |                                                               |
 282  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 283  */
 284
 285 struct icmp_ext_t {
 286     uint8_t icmp_type;
 287     uint8_t icmp_code;
 288     uint8_t icmp_checksum[2];
 289     uint8_t icmp_reserved;
 290     uint8_t icmp_length;
 291     uint8_t icmp_reserved2[2];
 292     uint8_t icmp_ext_legacy_header[128]; /* extension header starts 128 bytes after ICMP header */
 293     uint8_t icmp_ext_version_res[2];
 294     uint8_t icmp_ext_checksum[2];
 295     uint8_t icmp_ext_data[1];
 296 };
 297
 298 struct icmp_mpls_ext_object_header_t {
 299     uint8_t length[2];
 300     uint8_t class_num;
 301     uint8_t ctype;
 302 };
 303
 304 static const struct tok icmp_mpls_ext_obj_values[] = {
 305     { 1, "MPLS Stack Entry" },
 306     { 2, "Extended Payload" },
 307     { 0, NULL}
 308 };
 309
 310 /* prototypes */
 311 const char *icmp_tstamp_print(u_int);
 312
 313 /* print the milliseconds since midnight UTC */
 314 const char *
 315 icmp_tstamp_print(u_int tstamp)
 316 {
 317     u_int msec,sec,min,hrs;
 318
 319     static char buf[64];
 320
 321     msec = tstamp % 1000;
 322     sec = tstamp / 1000;
 323     min = sec / 60; sec -= min * 60;
 324     hrs = min / 60; min -= hrs * 60;
 325     snprintf(buf, sizeof(buf), "%02u:%02u:%02u.%03u",hrs,min,sec,msec);
 326     return buf;
 327 }
 328
 329 void
 330 icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *bp2,
 331            int fragmented)
 332 {
 333         char *cp;
 334         const struct icmp *dp;
 335         const struct icmp_ext_t *ext_dp;
 336         const struct ip *ip;
 337         const char *str, *fmt;
 338         const struct ip *oip;
 339         const struct udphdr *ouh;
 340         const uint8_t *obj_tptr;
 341         uint32_t raw_label;
 342         const u_char *snapend_save;
 343         const struct icmp_mpls_ext_object_header_t *icmp_mpls_ext_object_header;
 344         u_int hlen, dport, mtu, obj_tlen, obj_class_num, obj_ctype;
 345         char buf[MAXHOSTNAMELEN + 100];
 346         struct cksum_vec vec[1];
 347
 348         dp = (const struct icmp *)bp;
 349         ext_dp = (const struct icmp_ext_t *)bp;
 350         ip = (const struct ip *)bp2;
 351         str = buf;
 352
 353         ND_TCHECK(dp->icmp_code);
 354         switch (dp->icmp_type) {
 355
 356         case ICMP_ECHO:
 357         case ICMP_ECHOREPLY:
 358                 ND_TCHECK(dp->icmp_seq);
 359                 (void)snprintf(buf, sizeof(buf), "echo %s, id %u, seq %u",
 360                                dp->icmp_type == ICMP_ECHO ?
 361                                "request" : "reply",
 362                                EXTRACT_16BITS(&dp->icmp_id),
 363                                EXTRACT_16BITS(&dp->icmp_seq));
 364                 break;
 365
 366         case ICMP_UNREACH:
 367                 ND_TCHECK(dp->icmp_ip.ip_dst);
 368                 switch (dp->icmp_code) {
 369
 370                 case ICMP_UNREACH_PROTOCOL:
 371                         ND_TCHECK(dp->icmp_ip.ip_p);
 372                         (void)snprintf(buf, sizeof(buf),
 373                             "%s protocol %d unreachable",
 374                             ipaddr_string(ndo, &dp->icmp_ip.ip_dst),
 375                             dp->icmp_ip.ip_p);
 376                         break;
 377
 378                 case ICMP_UNREACH_PORT:
 379                         ND_TCHECK(dp->icmp_ip.ip_p);
 380                         oip = &dp->icmp_ip;
 381                         hlen = IP_HL(oip) * 4;
 382                         ouh = (const struct udphdr *)(((const u_char *)oip) + hlen);
 383                         ND_TCHECK(ouh->uh_dport);
 384                         dport = EXTRACT_16BITS(&ouh->uh_dport);
 385                         switch (oip->ip_p) {
 386
 387                         case IPPROTO_TCP:
 388                                 (void)snprintf(buf, sizeof(buf),
 389                                         "%s tcp port %s unreachable",
 390                                         ipaddr_string(ndo, &oip->ip_dst),
 391                                         tcpport_string(ndo, dport));
 392                                 break;
 393
 394                         case IPPROTO_UDP:
 395                                 (void)snprintf(buf, sizeof(buf),
 396                                         "%s udp port %s unreachable",
 397                                         ipaddr_string(ndo, &oip->ip_dst),
 398                                         udpport_string(ndo, dport));
 399                                 break;
 400
 401                         default:
 402                                 (void)snprintf(buf, sizeof(buf),
 403                                         "%s protocol %u port %u unreachable",
 404                                         ipaddr_string(ndo, &oip->ip_dst),
 405                                         oip->ip_p, dport);
 406                                 break;
 407                         }
 408                         break;
 409
 410                 case ICMP_UNREACH_NEEDFRAG:
 411                     {
 412                         register const struct mtu_discovery *mp;
 413                         mp = (const struct mtu_discovery *)(const u_char *)&dp->icmp_void;
 414                         mtu = EXTRACT_16BITS(&mp->nexthopmtu);
 415                         if (mtu) {
 416                                 (void)snprintf(buf, sizeof(buf),
 417                                     "%s unreachable - need to frag (mtu %d)",
 418                                     ipaddr_string(ndo, &dp->icmp_ip.ip_dst), mtu);
 419                         } else {
 420                                 (void)snprintf(buf, sizeof(buf),
 421                                     "%s unreachable - need to frag",
 422                                     ipaddr_string(ndo, &dp->icmp_ip.ip_dst));
 423                         }
 424                     }
 425                         break;
 426
 427                 default:
 428                         fmt = tok2str(unreach2str, "#%d %%s unreachable",
 429                             dp->icmp_code);
 430                         (void)snprintf(buf, sizeof(buf), fmt,
 431                             ipaddr_string(ndo, &dp->icmp_ip.ip_dst));
 432                         break;
 433                 }
 434                 break;
 435
 436         case ICMP_REDIRECT:
 437                 ND_TCHECK(dp->icmp_ip.ip_dst);
 438                 fmt = tok2str(type2str, "redirect-#%d %%s to net %%s",
 439                     dp->icmp_code);
 440                 (void)snprintf(buf, sizeof(buf), fmt,
 441                     ipaddr_string(ndo, &dp->icmp_ip.ip_dst),
 442                     ipaddr_string(ndo, &dp->icmp_gwaddr));
 443                 break;
 444
 445         case ICMP_ROUTERADVERT:
 446             {
 447                 register const struct ih_rdiscovery *ihp;
 448                 register const struct id_rdiscovery *idp;
 449                 u_int lifetime, num, size;
 450
 451                 (void)snprintf(buf, sizeof(buf), "router advertisement");
 452                 cp = buf + strlen(buf);
 453
 454                 ihp = (const struct ih_rdiscovery *)&dp->icmp_void;
 455                 ND_TCHECK(*ihp);
 456                 (void)strncpy(cp, " lifetime ", sizeof(buf) - (cp - buf));
 457                 cp = buf + strlen(buf);
 458                 lifetime = EXTRACT_16BITS(&ihp->ird_lifetime);
 459                 if (lifetime < 60) {
 460                         (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u",
 461                             lifetime);
 462                 } else if (lifetime < 60 * 60) {
 463                         (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u:%02u",
 464                             lifetime / 60, lifetime % 60);
 465                 } else {
 466                         (void)snprintf(cp, sizeof(buf) - (cp - buf),
 467                             "%u:%02u:%02u",
 468                             lifetime / 3600,
 469                             (lifetime % 3600) / 60,
 470                             lifetime % 60);
 471                 }
 472                 cp = buf + strlen(buf);
 473
 474                 num = ihp->ird_addrnum;
 475                 (void)snprintf(cp, sizeof(buf) - (cp - buf), " %d:", num);
 476                 cp = buf + strlen(buf);
 477
 478                 size = ihp->ird_addrsiz;
 479                 if (size != 2) {
 480                         (void)snprintf(cp, sizeof(buf) - (cp - buf),
 481                             " [size %d]", size);
 482                         break;
 483                 }
 484                 idp = (const struct id_rdiscovery *)&dp->icmp_data;
 485                 while (num-- > 0) {
 486                         ND_TCHECK(*idp);
 487                         (void)snprintf(cp, sizeof(buf) - (cp - buf), " {%s %u}",
 488                             ipaddr_string(ndo, &idp->ird_addr),
 489                             EXTRACT_32BITS(&idp->ird_pref));
 490                         cp = buf + strlen(buf);
 491                         ++idp;
 492                 }
 493             }
 494                 break;
 495
 496         case ICMP_TIMXCEED:
 497                 ND_TCHECK(dp->icmp_ip.ip_dst);
 498                 switch (dp->icmp_code) {
 499
 500                 case ICMP_TIMXCEED_INTRANS:
 501                         str = "time exceeded in-transit";
 502                         break;
 503
 504                 case ICMP_TIMXCEED_REASS:
 505                         str = "ip reassembly time exceeded";
 506                         break;
 507
 508                 default:
 509                         (void)snprintf(buf, sizeof(buf), "time exceeded-#%u",
 510                             dp->icmp_code);
 511                         break;
 512                 }
 513                 break;
 514
 515         case ICMP_PARAMPROB:
 516                 if (dp->icmp_code)
 517                         (void)snprintf(buf, sizeof(buf),
 518                             "parameter problem - code %u", dp->icmp_code);
 519                 else {
 520                         ND_TCHECK(dp->icmp_pptr);
 521                         (void)snprintf(buf, sizeof(buf),
 522                             "parameter problem - octet %u", dp->icmp_pptr);
 523                 }
 524                 break;
 525
 526         case ICMP_MASKREPLY:
 527                 ND_TCHECK(dp->icmp_mask);
 528                 (void)snprintf(buf, sizeof(buf), "address mask is 0x%08x",
 529                     EXTRACT_32BITS(&dp->icmp_mask));
 530                 break;
 531
 532         case ICMP_TSTAMP:
 533                 ND_TCHECK(dp->icmp_seq);
 534                 (void)snprintf(buf, sizeof(buf),
 535                     "time stamp query id %u seq %u",
 536                     EXTRACT_16BITS(&dp->icmp_id),
 537                     EXTRACT_16BITS(&dp->icmp_seq));
 538                 break;
 539
 540         case ICMP_TSTAMPREPLY:
 541                 ND_TCHECK(dp->icmp_ttime);
 542                 (void)snprintf(buf, sizeof(buf),
 543                     "time stamp reply id %u seq %u: org %s",
 544                                EXTRACT_16BITS(&dp->icmp_id),
 545                                EXTRACT_16BITS(&dp->icmp_seq),
 546                                icmp_tstamp_print(EXTRACT_32BITS(&dp->icmp_otime)));
 547
 548                 (void)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", recv %s",
 549                          icmp_tstamp_print(EXTRACT_32BITS(&dp->icmp_rtime)));
 550                 (void)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", xmit %s",
 551                          icmp_tstamp_print(EXTRACT_32BITS(&dp->icmp_ttime)));
 552                 break;
 553
 554         default:
 555                 str = tok2str(icmp2str, "type-#%d", dp->icmp_type);
 556                 break;
 557         }
 558         ND_PRINT((ndo, "ICMP %s, length %u", str, plen));
 559         if (ndo->ndo_vflag && !fragmented) { /* don't attempt checksumming if this is a frag */
 560                 if (ND_TTEST2(*bp, plen)) {
 561                         uint16_t sum;
 562
 563                         vec[0].ptr = (const uint8_t *)(const void *)dp;
 564                         vec[0].len = plen;
 565                         sum = in_cksum(vec, 1);
 566                         if (sum != 0) {
 567                                 uint16_t icmp_sum;
 568                                 ND_TCHECK_16BITS(&dp->icmp_cksum);
 569                                 icmp_sum = EXTRACT_16BITS(&dp->icmp_cksum);
 570                                 ND_PRINT((ndo, " (wrong icmp cksum %x (->%x)!)",
 571                                              icmp_sum,
 572                                              in_cksum_shouldbe(icmp_sum, sum)));
 573                         }
 574                 }
 575         }
 576
 577         /*
 578          * print the remnants of the IP packet.
 579          * save the snaplength as this may get overidden in the IP printer.
 580          */
 581         if (ndo->ndo_vflag >= 1 && ICMP_ERRTYPE(dp->icmp_type)) {
 582                 bp += 8;
 583                 ND_PRINT((ndo, "\n\t"));
 584                 ip = (const struct ip *)bp;
 585                 ndo->ndo_snaplen = ndo->ndo_snapend - bp;
 586                 snapend_save = ndo->ndo_snapend;
 587                 ND_TCHECK_16BITS(&ip->ip_len);
 588                 ip_print(ndo, bp, EXTRACT_16BITS(&ip->ip_len));
 589                 ndo->ndo_snapend = snapend_save;
 590         }
 591
 592         /*
 593          * Attempt to decode the MPLS extensions only for some ICMP types.
 594          */
 595         if (ndo->ndo_vflag >= 1 && plen > ICMP_EXTD_MINLEN && ICMP_MPLS_EXT_TYPE(dp->icmp_type)) {
 596
 597             ND_TCHECK(*ext_dp);
 598
 599             /*
 600              * Check first if the mpls extension header shows a non-zero length.
 601              * If the length field is not set then silently verify the checksum
 602              * to check if an extension header is present. This is expedient,
 603              * however not all implementations set the length field proper.
 604              */
 605             if (!ext_dp->icmp_length &&
 606                 ND_TTEST2(ext_dp->icmp_ext_version_res, plen - ICMP_EXTD_MINLEN)) {
 607                 vec[0].ptr = (const uint8_t *)(const void *)&ext_dp->icmp_ext_version_res;
 608                 vec[0].len = plen - ICMP_EXTD_MINLEN;
 609                 if (in_cksum(vec, 1)) {
 610                     return;
 611                 }
 612             }
 613
 614             ND_PRINT((ndo, "\n\tMPLS extension v%u",
 615                    ICMP_MPLS_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res))));
 616
 617             /*
 618              * Sanity checking of the header.
 619              */
 620             if (ICMP_MPLS_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res)) !=
 621                 ICMP_MPLS_EXT_VERSION) {
 622                 ND_PRINT((ndo, " packet not supported"));
 623                 return;
 624             }
 625
 626             hlen = plen - ICMP_EXTD_MINLEN;
 627             if (ND_TTEST2(ext_dp->icmp_ext_version_res, hlen)) {
 628                 vec[0].ptr = (const uint8_t *)(const void *)&ext_dp->icmp_ext_version_res;
 629                 vec[0].len = hlen;
 630                 ND_PRINT((ndo, ", checksum 0x%04x (%scorrect), length %u",
 631                        EXTRACT_16BITS(ext_dp->icmp_ext_checksum),
 632                        in_cksum(vec, 1) ? "in" : "",
 633                        hlen));
 634             }
 635
 636             hlen -= 4; /* subtract common header size */
 637             obj_tptr = (const uint8_t *)ext_dp->icmp_ext_data;
 638
 639             while (hlen > sizeof(struct icmp_mpls_ext_object_header_t)) {
 640
 641                 icmp_mpls_ext_object_header = (const struct icmp_mpls_ext_object_header_t *)obj_tptr;
 642                 ND_TCHECK(*icmp_mpls_ext_object_header);
 643                 obj_tlen = EXTRACT_16BITS(icmp_mpls_ext_object_header->length);
 644                 obj_class_num = icmp_mpls_ext_object_header->class_num;
 645                 obj_ctype = icmp_mpls_ext_object_header->ctype;
 646                 obj_tptr += sizeof(struct icmp_mpls_ext_object_header_t);
 647
 648                 ND_PRINT((ndo, "\n\t  %s Object (%u), Class-Type: %u, length %u",
 649                        tok2str(icmp_mpls_ext_obj_values,"unknown",obj_class_num),
 650                        obj_class_num,
 651                        obj_ctype,
 652                        obj_tlen));
 653
 654                 hlen-=sizeof(struct icmp_mpls_ext_object_header_t); /* length field includes tlv header */
 655
 656                 /* infinite loop protection */
 657                 if ((obj_class_num == 0) ||
 658                     (obj_tlen < sizeof(struct icmp_mpls_ext_object_header_t))) {
 659                     return;
 660                 }
 661                 obj_tlen-=sizeof(struct icmp_mpls_ext_object_header_t);
 662
 663                 switch (obj_class_num) {
 664                 case 1:
 665                     switch(obj_ctype) {
 666                     case 1:
 667                         ND_TCHECK2(*obj_tptr, 4);
 668                         raw_label = EXTRACT_32BITS(obj_tptr);
 669                         ND_PRINT((ndo, "\n\t    label %u, exp %u", MPLS_LABEL(raw_label), MPLS_EXP(raw_label)));
 670                         if (MPLS_STACK(raw_label))
 671                             ND_PRINT((ndo, ", [S]"));
 672                         ND_PRINT((ndo, ", ttl %u", MPLS_TTL(raw_label)));
 673                         break;
 674                     default:
 675                         print_unknown_data(ndo, obj_tptr, "\n\t    ", obj_tlen);
 676                     }
 677                     break;
 678
 679                /*
 680                 *  FIXME those are the defined objects that lack a decoder
 681                 *  you are welcome to contribute code ;-)
 682                 */
 683                 case 2:
 684                 default:
 685                     print_unknown_data(ndo, obj_tptr, "\n\t    ", obj_tlen);
 686                     break;
 687                 }
 688                 if (hlen < obj_tlen)
 689                     break;
 690                 hlen -= obj_tlen;
 691                 obj_tptr += obj_tlen;
 692             }
 693         }
 694
 695         return;
 696 trunc:
 697         ND_PRINT((ndo, "[|icmp]"));
 698 }
 699 /*
 700  * Local Variables:
 701  * c-style: whitesmith
 702  * c-basic-offset: 8
 703  * End:
 704  */