The Tcpdump Group git mirrors - tcpdump/blob - 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 #ifndef lint
  23 static const char rcsid[] =
  24     "@(#) $Header: /tcpdump/master/tcpdump/print-icmp.c,v 1.64 2002-06-01 23:50:32 guy Exp $ (LBL)";
  25 #endif
  26
  27 #ifdef HAVE_CONFIG_H
  28 #include "config.h"
  29 #endif
  30
  31 #include <sys/param.h>
  32 #include <sys/time.h>
  33 #include <sys/socket.h>
  34
  35 #include <netinet/in.h>
  36
  37 #include <stdio.h>
  38 #include <string.h>
  39 #include <netdb.h>              /* for MAXHOSTNAMELEN on some platforms */
  40
  41 #include "interface.h"
  42 #include "addrtoname.h"
  43 #include "extract.h"                    /* must come after interface.h */
  44
  45 #include "ip.h"
  46 #include "udp.h"
  47
  48 /*
  49  * Interface Control Message Protocol Definitions.
  50  * Per RFC 792, September 1981.
  51  */
  52
  53 /*
  54  * Structure of an icmp header.
  55  */
  56 struct icmp {
  57         u_int8_t  icmp_type;            /* type of message, see below */
  58         u_int8_t  icmp_code;            /* type sub code */
  59         u_int16_t icmp_cksum;           /* ones complement cksum of struct */
  60         union {
  61                 u_int8_t ih_pptr;                       /* ICMP_PARAMPROB */
  62                 struct in_addr ih_gwaddr;       /* ICMP_REDIRECT */
  63                 struct ih_idseq {
  64                         u_int16_t icd_id;
  65                         u_int16_t icd_seq;
  66                 } ih_idseq;
  67                 u_int32_t ih_void;
  68
  69                 /* ICMP_UNREACH_NEEDFRAG -- Path MTU Discovery (RFC1191) */
  70                 struct ih_pmtu {
  71                         u_int16_t ipm_void;
  72                         u_int16_t ipm_nextmtu;
  73                 } ih_pmtu;
  74         } icmp_hun;
  75 #define icmp_pptr       icmp_hun.ih_pptr
  76 #define icmp_gwaddr     icmp_hun.ih_gwaddr
  77 #define icmp_id         icmp_hun.ih_idseq.icd_id
  78 #define icmp_seq        icmp_hun.ih_idseq.icd_seq
  79 #define icmp_void       icmp_hun.ih_void
  80 #define icmp_pmvoid     icmp_hun.ih_pmtu.ipm_void
  81 #define icmp_nextmtu    icmp_hun.ih_pmtu.ipm_nextmtu
  82         union {
  83                 struct id_ts {
  84                         u_int32_t its_otime;
  85                         u_int32_t its_rtime;
  86                         u_int32_t its_ttime;
  87                 } id_ts;
  88                 struct id_ip  {
  89                         struct ip idi_ip;
  90                         /* options and then 64 bits of data */
  91                 } id_ip;
  92                 u_int32_t id_mask;
  93                 u_int8_t id_data[1];
  94         } icmp_dun;
  95 #define icmp_otime      icmp_dun.id_ts.its_otime
  96 #define icmp_rtime      icmp_dun.id_ts.its_rtime
  97 #define icmp_ttime      icmp_dun.id_ts.its_ttime
  98 #define icmp_ip         icmp_dun.id_ip.idi_ip
  99 #define icmp_mask       icmp_dun.id_mask
 100 #define icmp_data       icmp_dun.id_data
 101 };
 102
 103 /*
 104  * Lower bounds on packet lengths for various types.
 105  * For the error advice packets must first insure that the
 106  * packet is large enought to contain the returned ip header.
 107  * Only then can we do the check to see if 64 bits of packet
 108  * data have been returned, since we need to check the returned
 109  * ip header length.
 110  */
 111 #define ICMP_MINLEN     8                               /* abs minimum */
 112 #define ICMP_TSLEN      (8 + 3 * sizeof (u_int32_t))    /* timestamp */
 113 #define ICMP_MASKLEN    12                              /* address mask */
 114 #define ICMP_ADVLENMIN  (8 + sizeof (struct ip) + 8)    /* min */
 115 #define ICMP_ADVLEN(p)  (8 + (IP_HL(&(p)->icmp_ip) << 2) + 8)
 116         /* N.B.: must separately check that ip_hl >= 5 */
 117
 118 /*
 119  * Definition of type and code field values.
 120  */
 121 #define ICMP_ECHOREPLY          0               /* echo reply */
 122 #define ICMP_UNREACH            3               /* dest unreachable, codes: */
 123 #define         ICMP_UNREACH_NET        0               /* bad net */
 124 #define         ICMP_UNREACH_HOST       1               /* bad host */
 125 #define         ICMP_UNREACH_PROTOCOL   2               /* bad protocol */
 126 #define         ICMP_UNREACH_PORT       3               /* bad port */
 127 #define         ICMP_UNREACH_NEEDFRAG   4               /* IP_DF caused drop */
 128 #define         ICMP_UNREACH_SRCFAIL    5               /* src route failed */
 129 #define         ICMP_UNREACH_NET_UNKNOWN 6              /* unknown net */
 130 #define         ICMP_UNREACH_HOST_UNKNOWN 7             /* unknown host */
 131 #define         ICMP_UNREACH_ISOLATED   8               /* src host isolated */
 132 #define         ICMP_UNREACH_NET_PROHIB 9               /* prohibited access */
 133 #define         ICMP_UNREACH_HOST_PROHIB 10             /* ditto */
 134 #define         ICMP_UNREACH_TOSNET     11              /* bad tos for net */
 135 #define         ICMP_UNREACH_TOSHOST    12              /* bad tos for host */
 136 #define ICMP_SOURCEQUENCH       4               /* packet lost, slow down */
 137 #define ICMP_REDIRECT           5               /* shorter route, codes: */
 138 #define         ICMP_REDIRECT_NET       0               /* for network */
 139 #define         ICMP_REDIRECT_HOST      1               /* for host */
 140 #define         ICMP_REDIRECT_TOSNET    2               /* for tos and net */
 141 #define         ICMP_REDIRECT_TOSHOST   3               /* for tos and host */
 142 #define ICMP_ECHO               8               /* echo service */
 143 #define ICMP_ROUTERADVERT       9               /* router advertisement */
 144 #define ICMP_ROUTERSOLICIT      10              /* router solicitation */
 145 #define ICMP_TIMXCEED           11              /* time exceeded, code: */
 146 #define         ICMP_TIMXCEED_INTRANS   0               /* ttl==0 in transit */
 147 #define         ICMP_TIMXCEED_REASS     1               /* ttl==0 in reass */
 148 #define ICMP_PARAMPROB          12              /* ip header bad */
 149 #define         ICMP_PARAMPROB_OPTABSENT 1              /* req. opt. absent */
 150 #define ICMP_TSTAMP             13              /* timestamp request */
 151 #define ICMP_TSTAMPREPLY        14              /* timestamp reply */
 152 #define ICMP_IREQ               15              /* information request */
 153 #define ICMP_IREQREPLY          16              /* information reply */
 154 #define ICMP_MASKREQ            17              /* address mask request */
 155 #define ICMP_MASKREPLY          18              /* address mask reply */
 156
 157 #define ICMP_MAXTYPE            18
 158
 159 #define ICMP_INFOTYPE(type) \
 160         ((type) == ICMP_ECHOREPLY || (type) == ICMP_ECHO || \
 161         (type) == ICMP_ROUTERADVERT || (type) == ICMP_ROUTERSOLICIT || \
 162         (type) == ICMP_TSTAMP || (type) == ICMP_TSTAMPREPLY || \
 163         (type) == ICMP_IREQ || (type) == ICMP_IREQREPLY || \
 164         (type) == ICMP_MASKREQ || (type) == ICMP_MASKREPLY)
 165 /* rfc1700 */
 166 #ifndef ICMP_UNREACH_NET_UNKNOWN
 167 #define ICMP_UNREACH_NET_UNKNOWN        6       /* destination net unknown */
 168 #endif
 169 #ifndef ICMP_UNREACH_HOST_UNKNOWN
 170 #define ICMP_UNREACH_HOST_UNKNOWN       7       /* destination host unknown */
 171 #endif
 172 #ifndef ICMP_UNREACH_ISOLATED
 173 #define ICMP_UNREACH_ISOLATED           8       /* source host isolated */
 174 #endif
 175 #ifndef ICMP_UNREACH_NET_PROHIB
 176 #define ICMP_UNREACH_NET_PROHIB         9       /* admin prohibited net */
 177 #endif
 178 #ifndef ICMP_UNREACH_HOST_PROHIB
 179 #define ICMP_UNREACH_HOST_PROHIB        10      /* admin prohibited host */
 180 #endif
 181 #ifndef ICMP_UNREACH_TOSNET
 182 #define ICMP_UNREACH_TOSNET             11      /* tos prohibited net */
 183 #endif
 184 #ifndef ICMP_UNREACH_TOSHOST
 185 #define ICMP_UNREACH_TOSHOST            12      /* tos prohibited host */
 186 #endif
 187
 188 /* rfc1716 */
 189 #ifndef ICMP_UNREACH_FILTER_PROHIB
 190 #define ICMP_UNREACH_FILTER_PROHIB      13      /* admin prohibited filter */
 191 #endif
 192 #ifndef ICMP_UNREACH_HOST_PRECEDENCE
 193 #define ICMP_UNREACH_HOST_PRECEDENCE    14      /* host precedence violation */
 194 #endif
 195 #ifndef ICMP_UNREACH_PRECEDENCE_CUTOFF
 196 #define ICMP_UNREACH_PRECEDENCE_CUTOFF  15      /* precedence cutoff */
 197 #endif
 198
 199 /* Most of the icmp types */
 200 static struct tok icmp2str[] = {
 201         { ICMP_ECHOREPLY,               "echo reply" },
 202         { ICMP_SOURCEQUENCH,            "source quench" },
 203         { ICMP_ECHO,                    "echo request" },
 204         { ICMP_ROUTERSOLICIT,           "router solicitation" },
 205         { ICMP_TSTAMP,                  "time stamp request" },
 206         { ICMP_TSTAMPREPLY,             "time stamp reply" },
 207         { ICMP_IREQ,                    "information request" },
 208         { ICMP_IREQREPLY,               "information reply" },
 209         { ICMP_MASKREQ,                 "address mask request" },
 210         { 0,                            NULL }
 211 };
 212
 213 /* Formats for most of the ICMP_UNREACH codes */
 214 static struct tok unreach2str[] = {
 215         { ICMP_UNREACH_NET,             "net %s unreachable" },
 216         { ICMP_UNREACH_HOST,            "host %s unreachable" },
 217         { ICMP_UNREACH_SRCFAIL,
 218             "%s unreachable - source route failed" },
 219         { ICMP_UNREACH_NET_UNKNOWN,     "net %s unreachable - unknown" },
 220         { ICMP_UNREACH_HOST_UNKNOWN,    "host %s unreachable - unknown" },
 221         { ICMP_UNREACH_ISOLATED,
 222             "%s unreachable - source host isolated" },
 223         { ICMP_UNREACH_NET_PROHIB,
 224             "net %s unreachable - admin prohibited" },
 225         { ICMP_UNREACH_HOST_PROHIB,
 226             "host %s unreachable - admin prohibited" },
 227         { ICMP_UNREACH_TOSNET,
 228             "net %s unreachable - tos prohibited" },
 229         { ICMP_UNREACH_TOSHOST,
 230             "host %s unreachable - tos prohibited" },
 231         { ICMP_UNREACH_FILTER_PROHIB,
 232             "host %s unreachable - admin prohibited filter" },
 233         { ICMP_UNREACH_HOST_PRECEDENCE,
 234             "host %s unreachable - host precedence violation" },
 235         { ICMP_UNREACH_PRECEDENCE_CUTOFF,
 236             "host %s unreachable - precedence cutoff" },
 237         { 0,                            NULL }
 238 };
 239
 240 /* Formats for the ICMP_REDIRECT codes */
 241 static struct tok type2str[] = {
 242         { ICMP_REDIRECT_NET,            "redirect %s to net %s" },
 243         { ICMP_REDIRECT_HOST,           "redirect %s to host %s" },
 244         { ICMP_REDIRECT_TOSNET,         "redirect-tos %s to net %s" },
 245         { ICMP_REDIRECT_TOSHOST,        "redirect-tos %s to host %s" },
 246         { 0,                            NULL }
 247 };
 248
 249 /* rfc1191 */
 250 struct mtu_discovery {
 251         u_int16_t unused;
 252         u_int16_t nexthopmtu;
 253 };
 254
 255 /* rfc1256 */
 256 struct ih_rdiscovery {
 257         u_int8_t ird_addrnum;
 258         u_int8_t ird_addrsiz;
 259         u_int16_t ird_lifetime;
 260 };
 261
 262 struct id_rdiscovery {
 263         u_int32_t ird_addr;
 264         u_int32_t ird_pref;
 265 };
 266
 267 void
 268 icmp_print(const u_char *bp, u_int plen, const u_char *bp2)
 269 {
 270         char *cp;
 271         const struct icmp *dp;
 272         const struct ip *ip;
 273         const char *str, *fmt;
 274         const struct ip *oip;
 275         const struct udphdr *ouh;
 276         u_int hlen, dport, mtu;
 277         char buf[MAXHOSTNAMELEN + 100];
 278
 279         dp = (struct icmp *)bp;
 280         ip = (struct ip *)bp2;
 281         str = buf;
 282
 283         TCHECK(dp->icmp_code);
 284         switch (dp->icmp_type) {
 285
 286         case ICMP_ECHO:
 287                 TCHECK(dp->icmp_seq);
 288                 (void)snprintf(buf, sizeof(buf), "echo request seq %u",
 289                         (unsigned)ntohs(dp->icmp_seq));
 290                 break;
 291
 292         case ICMP_ECHOREPLY:
 293                 TCHECK(dp->icmp_seq);
 294                 (void)snprintf(buf, sizeof(buf), "echo reply seq %u",
 295                         (unsigned)ntohs(dp->icmp_seq));
 296                 break;
 297
 298         case ICMP_UNREACH:
 299                 TCHECK(dp->icmp_ip.ip_dst);
 300                 switch (dp->icmp_code) {
 301
 302                 case ICMP_UNREACH_PROTOCOL:
 303                         TCHECK(dp->icmp_ip.ip_p);
 304                         (void)snprintf(buf, sizeof(buf),
 305                             "%s protocol %d unreachable",
 306                             ipaddr_string(&dp->icmp_ip.ip_dst),
 307                             dp->icmp_ip.ip_p);
 308                         break;
 309
 310                 case ICMP_UNREACH_PORT:
 311                         TCHECK(dp->icmp_ip.ip_p);
 312                         oip = &dp->icmp_ip;
 313                         hlen = IP_HL(oip) * 4;
 314                         ouh = (struct udphdr *)(((u_char *)oip) + hlen);
 315                         dport = ntohs(ouh->uh_dport);
 316                         switch (oip->ip_p) {
 317
 318                         case IPPROTO_TCP:
 319                                 (void)snprintf(buf, sizeof(buf),
 320                                         "%s tcp port %s unreachable",
 321                                         ipaddr_string(&oip->ip_dst),
 322                                         tcpport_string(dport));
 323                                 break;
 324
 325                         case IPPROTO_UDP:
 326                                 (void)snprintf(buf, sizeof(buf),
 327                                         "%s udp port %s unreachable",
 328                                         ipaddr_string(&oip->ip_dst),
 329                                         udpport_string(dport));
 330                                 break;
 331
 332                         default:
 333                                 (void)snprintf(buf, sizeof(buf),
 334                                         "%s protocol %d port %d unreachable",
 335                                         ipaddr_string(&oip->ip_dst),
 336                                         oip->ip_p, dport);
 337                                 break;
 338                         }
 339                         break;
 340
 341                 case ICMP_UNREACH_NEEDFRAG:
 342                     {
 343                         register const struct mtu_discovery *mp;
 344                         mp = (struct mtu_discovery *)&dp->icmp_void;
 345                         mtu = EXTRACT_16BITS(&mp->nexthopmtu);
 346                         if (mtu) {
 347                                 (void)snprintf(buf, sizeof(buf),
 348                                     "%s unreachable - need to frag (mtu %d)",
 349                                     ipaddr_string(&dp->icmp_ip.ip_dst), mtu);
 350                         } else {
 351                                 (void)snprintf(buf, sizeof(buf),
 352                                     "%s unreachable - need to frag",
 353                                     ipaddr_string(&dp->icmp_ip.ip_dst));
 354                         }
 355                     }
 356                         break;
 357
 358                 default:
 359                         fmt = tok2str(unreach2str, "#%d %%s unreachable",
 360                             dp->icmp_code);
 361                         (void)snprintf(buf, sizeof(buf), fmt,
 362                             ipaddr_string(&dp->icmp_ip.ip_dst));
 363                         break;
 364                 }
 365                 break;
 366
 367         case ICMP_REDIRECT:
 368                 TCHECK(dp->icmp_ip.ip_dst);
 369                 fmt = tok2str(type2str, "redirect-#%d %%s to net %%s",
 370                     dp->icmp_code);
 371                 (void)snprintf(buf, sizeof(buf), fmt,
 372                     ipaddr_string(&dp->icmp_ip.ip_dst),
 373                     ipaddr_string(&dp->icmp_gwaddr));
 374                 break;
 375
 376         case ICMP_ROUTERADVERT:
 377             {
 378                 register const struct ih_rdiscovery *ihp;
 379                 register const struct id_rdiscovery *idp;
 380                 u_int lifetime, num, size;
 381
 382                 (void)snprintf(buf, sizeof(buf), "router advertisement");
 383                 cp = buf + strlen(buf);
 384
 385                 ihp = (struct ih_rdiscovery *)&dp->icmp_void;
 386                 TCHECK(*ihp);
 387                 (void)strncpy(cp, " lifetime ", sizeof(buf) - (cp - buf));
 388                 cp = buf + strlen(buf);
 389                 lifetime = EXTRACT_16BITS(&ihp->ird_lifetime);
 390                 if (lifetime < 60) {
 391                         (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u",
 392                             lifetime);
 393                 } else if (lifetime < 60 * 60) {
 394                         (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u:%02u",
 395                             lifetime / 60, lifetime % 60);
 396                 } else {
 397                         (void)snprintf(cp, sizeof(buf) - (cp - buf),
 398                             "%u:%02u:%02u",
 399                             lifetime / 3600,
 400                             (lifetime % 3600) / 60,
 401                             lifetime % 60);
 402                 }
 403                 cp = buf + strlen(buf);
 404
 405                 num = ihp->ird_addrnum;
 406                 (void)snprintf(cp, sizeof(buf) - (cp - buf), " %d:", num);
 407                 cp = buf + strlen(buf);
 408
 409                 size = ihp->ird_addrsiz;
 410                 if (size != 2) {
 411                         (void)snprintf(cp, sizeof(buf) - (cp - buf),
 412                             " [size %d]", size);
 413                         break;
 414                 }
 415                 idp = (struct id_rdiscovery *)&dp->icmp_data;
 416                 while (num-- > 0) {
 417                         TCHECK(*idp);
 418                         (void)snprintf(cp, sizeof(buf) - (cp - buf), " {%s %u}",
 419                             ipaddr_string(&idp->ird_addr),
 420                             EXTRACT_32BITS(&idp->ird_pref));
 421                         cp = buf + strlen(buf);
 422                         ++idp;
 423                 }
 424             }
 425                 break;
 426
 427         case ICMP_TIMXCEED:
 428                 TCHECK(dp->icmp_ip.ip_dst);
 429                 switch (dp->icmp_code) {
 430
 431                 case ICMP_TIMXCEED_INTRANS:
 432                         str = "time exceeded in-transit";
 433                         break;
 434
 435                 case ICMP_TIMXCEED_REASS:
 436                         str = "ip reassembly time exceeded";
 437                         break;
 438
 439                 default:
 440                         (void)snprintf(buf, sizeof(buf), "time exceeded-#%d",
 441                             dp->icmp_code);
 442                         break;
 443                 }
 444                 break;
 445
 446         case ICMP_PARAMPROB:
 447                 if (dp->icmp_code)
 448                         (void)snprintf(buf, sizeof(buf),
 449                             "parameter problem - code %d", dp->icmp_code);
 450                 else {
 451                         TCHECK(dp->icmp_pptr);
 452                         (void)snprintf(buf, sizeof(buf),
 453                             "parameter problem - octet %d", dp->icmp_pptr);
 454                 }
 455                 break;
 456
 457         case ICMP_MASKREPLY:
 458                 TCHECK(dp->icmp_mask);
 459                 (void)snprintf(buf, sizeof(buf), "address mask is 0x%08x",
 460                     (unsigned)ntohl(dp->icmp_mask));
 461                 break;
 462
 463         case ICMP_TSTAMP:
 464                 TCHECK(dp->icmp_seq);
 465                 (void)snprintf(buf, sizeof(buf),
 466                     "time stamp query id %u seq %u",
 467                     (unsigned)ntohs(dp->icmp_id),
 468                     (unsigned)ntohs(dp->icmp_seq));
 469                 break;
 470
 471         case ICMP_TSTAMPREPLY:
 472                 TCHECK(dp->icmp_ttime);
 473                 (void)snprintf(buf, sizeof(buf),
 474                     "time stamp reply id %u seq %u : org 0x%lx recv 0x%lx xmit 0x%lx",
 475                     (unsigned)ntohs(dp->icmp_id),
 476                     (unsigned)ntohs(dp->icmp_seq),
 477                     (unsigned long)ntohl(dp->icmp_otime),
 478                     (unsigned long)ntohl(dp->icmp_rtime),
 479                     (unsigned long)ntohl(dp->icmp_ttime));
 480                 break;
 481
 482         default:
 483                 str = tok2str(icmp2str, "type-#%d", dp->icmp_type);
 484                 break;
 485         }
 486         (void)printf("icmp: %s", str);
 487         if (vflag) {
 488                 if (TTEST2(*bp, plen)) {
 489                         if (in_cksum((u_short*)dp, plen, 0))
 490                                 printf(" (wrong icmp csum)");
 491                 }
 492         }
 493         if (vflag > 1 && !ICMP_INFOTYPE(dp->icmp_type)) {
 494                 bp += 8;
 495                 (void)printf(" for ");
 496                 ip = (struct ip *)bp;
 497                 snaplen = snapend - bp;
 498                 ip_print(bp, ntohs(ip->ip_len));
 499         }
 500         return;
 501 trunc:
 502         fputs("[|icmp]", stdout);
 503 }