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 #ifndef lint
  25 static const char rcsid[] =
  26     "@(#) $Header: /tcpdump/master/tcpdump/print-icmp.c,v 1.62 2001/07/24 16:56:11 fenner Exp $ (LBL)";
  27 #endif
  28
  29 #ifdef HAVE_CONFIG_H
  30 #include "config.h"
  31 #endif
  32
  33 #include <sys/param.h>
  34 #include <sys/time.h>
  35 #include <sys/socket.h>
  36
  37 struct mbuf;
  38 struct rtentry;
  39
  40 #include <netinet/in.h>
  41
  42 #include <stdio.h>
  43 #include <string.h>
  44 #include <netdb.h>              /* for MAXHOSTNAMELEN on some platforms */
  45
  46 #include "interface.h"
  47 #include "addrtoname.h"
  48 #include "extract.h"                    /* must come after interface.h */
  49
  50 #include "ip.h"
  51 #include "udp.h"
  52
  53 /*
  54  * Interface Control Message Protocol Definitions.
  55  * Per RFC 792, September 1981.
  56  */
  57
  58 /*
  59  * Structure of an icmp header.
  60  */
  61 struct icmp {
  62         u_int8_t  icmp_type;            /* type of message, see below */
  63         u_int8_t  icmp_code;            /* type sub code */
  64         u_int16_t icmp_cksum;           /* ones complement cksum of struct */
  65         union {
  66                 u_int8_t ih_pptr;                       /* ICMP_PARAMPROB */
  67                 struct in_addr ih_gwaddr;       /* ICMP_REDIRECT */
  68                 struct ih_idseq {
  69                         u_int16_t icd_id;
  70                         u_int16_t icd_seq;
  71                 } ih_idseq;
  72                 u_int32_t ih_void;
  73
  74                 /* ICMP_UNREACH_NEEDFRAG -- Path MTU Discovery (RFC1191) */
  75                 struct ih_pmtu {
  76                         u_int16_t ipm_void;
  77                         u_int16_t ipm_nextmtu;
  78                 } ih_pmtu;
  79         } icmp_hun;
  80 #define icmp_pptr       icmp_hun.ih_pptr
  81 #define icmp_gwaddr     icmp_hun.ih_gwaddr
  82 #define icmp_id         icmp_hun.ih_idseq.icd_id
  83 #define icmp_seq        icmp_hun.ih_idseq.icd_seq
  84 #define icmp_void       icmp_hun.ih_void
  85 #define icmp_pmvoid     icmp_hun.ih_pmtu.ipm_void
  86 #define icmp_nextmtu    icmp_hun.ih_pmtu.ipm_nextmtu
  87         union {
  88                 struct id_ts {
  89                         u_int32_t its_otime;
  90                         u_int32_t its_rtime;
  91                         u_int32_t its_ttime;
  92                 } id_ts;
  93                 struct id_ip  {
  94                         struct ip idi_ip;
  95                         /* options and then 64 bits of data */
  96                 } id_ip;
  97                 u_int32_t id_mask;
  98                 u_int8_t id_data[1];
  99         } icmp_dun;
 100 #define icmp_otime      icmp_dun.id_ts.its_otime
 101 #define icmp_rtime      icmp_dun.id_ts.its_rtime
 102 #define icmp_ttime      icmp_dun.id_ts.its_ttime
 103 #define icmp_ip         icmp_dun.id_ip.idi_ip
 104 #define icmp_mask       icmp_dun.id_mask
 105 #define icmp_data       icmp_dun.id_data
 106 };
 107
 108 /*
 109  * Lower bounds on packet lengths for various types.
 110  * For the error advice packets must first insure that the
 111  * packet is large enought to contain the returned ip header.
 112  * Only then can we do the check to see if 64 bits of packet
 113  * data have been returned, since we need to check the returned
 114  * ip header length.
 115  */
 116 #define ICMP_MINLEN     8                               /* abs minimum */
 117 #define ICMP_TSLEN      (8 + 3 * sizeof (u_int32_t))    /* timestamp */
 118 #define ICMP_MASKLEN    12                              /* address mask */
 119 #define ICMP_ADVLENMIN  (8 + sizeof (struct ip) + 8)    /* min */
 120 #define ICMP_ADVLEN(p)  (8 + (IP_HL(&(p)->icmp_ip) << 2) + 8)
 121         /* N.B.: must separately check that ip_hl >= 5 */
 122
 123 /*
 124  * Definition of type and code field values.
 125  */
 126 #define ICMP_ECHOREPLY          0               /* echo reply */
 127 #define ICMP_UNREACH            3               /* dest unreachable, codes: */
 128 #define         ICMP_UNREACH_NET        0               /* bad net */
 129 #define         ICMP_UNREACH_HOST       1               /* bad host */
 130 #define         ICMP_UNREACH_PROTOCOL   2               /* bad protocol */
 131 #define         ICMP_UNREACH_PORT       3               /* bad port */
 132 #define         ICMP_UNREACH_NEEDFRAG   4               /* IP_DF caused drop */
 133 #define         ICMP_UNREACH_SRCFAIL    5               /* src route failed */
 134 #define         ICMP_UNREACH_NET_UNKNOWN 6              /* unknown net */
 135 #define         ICMP_UNREACH_HOST_UNKNOWN 7             /* unknown host */
 136 #define         ICMP_UNREACH_ISOLATED   8               /* src host isolated */
 137 #define         ICMP_UNREACH_NET_PROHIB 9               /* prohibited access */
 138 #define         ICMP_UNREACH_HOST_PROHIB 10             /* ditto */
 139 #define         ICMP_UNREACH_TOSNET     11              /* bad tos for net */
 140 #define         ICMP_UNREACH_TOSHOST    12              /* bad tos for host */
 141 #define ICMP_SOURCEQUENCH       4               /* packet lost, slow down */
 142 #define ICMP_REDIRECT           5               /* shorter route, codes: */
 143 #define         ICMP_REDIRECT_NET       0               /* for network */
 144 #define         ICMP_REDIRECT_HOST      1               /* for host */
 145 #define         ICMP_REDIRECT_TOSNET    2               /* for tos and net */
 146 #define         ICMP_REDIRECT_TOSHOST   3               /* for tos and host */
 147 #define ICMP_ECHO               8               /* echo service */
 148 #define ICMP_ROUTERADVERT       9               /* router advertisement */
 149 #define ICMP_ROUTERSOLICIT      10              /* router solicitation */
 150 #define ICMP_TIMXCEED           11              /* time exceeded, code: */
 151 #define         ICMP_TIMXCEED_INTRANS   0               /* ttl==0 in transit */
 152 #define         ICMP_TIMXCEED_REASS     1               /* ttl==0 in reass */
 153 #define ICMP_PARAMPROB          12              /* ip header bad */
 154 #define         ICMP_PARAMPROB_OPTABSENT 1              /* req. opt. absent */
 155 #define ICMP_TSTAMP             13              /* timestamp request */
 156 #define ICMP_TSTAMPREPLY        14              /* timestamp reply */
 157 #define ICMP_IREQ               15              /* information request */
 158 #define ICMP_IREQREPLY          16              /* information reply */
 159 #define ICMP_MASKREQ            17              /* address mask request */
 160 #define ICMP_MASKREPLY          18              /* address mask reply */
 161
 162 #define ICMP_MAXTYPE            18
 163
 164 #define ICMP_INFOTYPE(type) \
 165         ((type) == ICMP_ECHOREPLY || (type) == ICMP_ECHO || \
 166         (type) == ICMP_ROUTERADVERT || (type) == ICMP_ROUTERSOLICIT || \
 167         (type) == ICMP_TSTAMP || (type) == ICMP_TSTAMPREPLY || \
 168         (type) == ICMP_IREQ || (type) == ICMP_IREQREPLY || \
 169         (type) == ICMP_MASKREQ || (type) == ICMP_MASKREPLY)
 170 /* rfc1700 */
 171 #ifndef ICMP_UNREACH_NET_UNKNOWN
 172 #define ICMP_UNREACH_NET_UNKNOWN        6       /* destination net unknown */
 173 #endif
 174 #ifndef ICMP_UNREACH_HOST_UNKNOWN
 175 #define ICMP_UNREACH_HOST_UNKNOWN       7       /* destination host unknown */
 176 #endif
 177 #ifndef ICMP_UNREACH_ISOLATED
 178 #define ICMP_UNREACH_ISOLATED           8       /* source host isolated */
 179 #endif
 180 #ifndef ICMP_UNREACH_NET_PROHIB
 181 #define ICMP_UNREACH_NET_PROHIB         9       /* admin prohibited net */
 182 #endif
 183 #ifndef ICMP_UNREACH_HOST_PROHIB
 184 #define ICMP_UNREACH_HOST_PROHIB        10      /* admin prohibited host */
 185 #endif
 186 #ifndef ICMP_UNREACH_TOSNET
 187 #define ICMP_UNREACH_TOSNET             11      /* tos prohibited net */
 188 #endif
 189 #ifndef ICMP_UNREACH_TOSHOST
 190 #define ICMP_UNREACH_TOSHOST            12      /* tos prohibited host */
 191 #endif
 192
 193 /* rfc1716 */
 194 #ifndef ICMP_UNREACH_FILTER_PROHIB
 195 #define ICMP_UNREACH_FILTER_PROHIB      13      /* admin prohibited filter */
 196 #endif
 197 #ifndef ICMP_UNREACH_HOST_PRECEDENCE
 198 #define ICMP_UNREACH_HOST_PRECEDENCE    14      /* host precedence violation */
 199 #endif
 200 #ifndef ICMP_UNREACH_PRECEDENCE_CUTOFF
 201 #define ICMP_UNREACH_PRECEDENCE_CUTOFF  15      /* precedence cutoff */
 202 #endif
 203
 204 /* Most of the icmp types */
 205 static struct tok icmp2str[] = {
 206         { ICMP_ECHOREPLY,               "echo reply" },
 207         { ICMP_SOURCEQUENCH,            "source quench" },
 208         { ICMP_ECHO,                    "echo request" },
 209         { ICMP_ROUTERSOLICIT,           "router solicitation" },
 210         { ICMP_TSTAMP,                  "time stamp request" },
 211         { ICMP_TSTAMPREPLY,             "time stamp reply" },
 212         { ICMP_IREQ,                    "information request" },
 213         { ICMP_IREQREPLY,               "information reply" },
 214         { ICMP_MASKREQ,                 "address mask request" },
 215         { 0,                            NULL }
 216 };
 217
 218 /* Formats for most of the ICMP_UNREACH codes */
 219 static struct tok unreach2str[] = {
 220         { ICMP_UNREACH_NET,             "net %s unreachable" },
 221         { ICMP_UNREACH_HOST,            "host %s unreachable" },
 222         { ICMP_UNREACH_SRCFAIL,
 223             "%s unreachable - source route failed" },
 224         { ICMP_UNREACH_NET_UNKNOWN,     "net %s unreachable - unknown" },
 225         { ICMP_UNREACH_HOST_UNKNOWN,    "host %s unreachable - unknown" },
 226         { ICMP_UNREACH_ISOLATED,
 227             "%s unreachable - source host isolated" },
 228         { ICMP_UNREACH_NET_PROHIB,
 229             "net %s unreachable - admin prohibited" },
 230         { ICMP_UNREACH_HOST_PROHIB,
 231             "host %s unreachable - admin prohibited" },
 232         { ICMP_UNREACH_TOSNET,
 233             "net %s unreachable - tos prohibited" },
 234         { ICMP_UNREACH_TOSHOST,
 235             "host %s unreachable - tos prohibited" },
 236         { ICMP_UNREACH_FILTER_PROHIB,
 237             "host %s unreachable - admin prohibited filter" },
 238         { ICMP_UNREACH_HOST_PRECEDENCE,
 239             "host %s unreachable - host precedence violation" },
 240         { ICMP_UNREACH_PRECEDENCE_CUTOFF,
 241             "host %s unreachable - precedence cutoff" },
 242         { 0,                            NULL }
 243 };
 244
 245 /* Formats for the ICMP_REDIRECT codes */
 246 static struct tok type2str[] = {
 247         { ICMP_REDIRECT_NET,            "redirect %s to net %s" },
 248         { ICMP_REDIRECT_HOST,           "redirect %s to host %s" },
 249         { ICMP_REDIRECT_TOSNET,         "redirect-tos %s to net %s" },
 250         { ICMP_REDIRECT_TOSHOST,        "redirect-tos %s to host %s" },
 251         { 0,                            NULL }
 252 };
 253
 254 /* rfc1191 */
 255 struct mtu_discovery {
 256         u_int16_t unused;
 257         u_int16_t nexthopmtu;
 258 };
 259
 260 /* rfc1256 */
 261 struct ih_rdiscovery {
 262         u_int8_t ird_addrnum;
 263         u_int8_t ird_addrsiz;
 264         u_int16_t ird_lifetime;
 265 };
 266
 267 struct id_rdiscovery {
 268         u_int32_t ird_addr;
 269         u_int32_t ird_pref;
 270 };
 271
 272 void
 273 icmp_print(const u_char *bp, u_int plen, const u_char *bp2)
 274 {
 275         char *cp;
 276         const struct icmp *dp;
 277         const struct ip *ip;
 278         const char *str, *fmt;
 279         const struct ip *oip;
 280         const struct udphdr *ouh;
 281         u_int hlen, dport, mtu;
 282         char buf[MAXHOSTNAMELEN + 100];
 283
 284         dp = (struct icmp *)bp;
 285         ip = (struct ip *)bp2;
 286         str = buf;
 287
 288         TCHECK(dp->icmp_code);
 289         switch (dp->icmp_type) {
 290
 291         case ICMP_UNREACH:
 292                 TCHECK(dp->icmp_ip.ip_dst);
 293                 switch (dp->icmp_code) {
 294
 295                 case ICMP_UNREACH_PROTOCOL:
 296                         TCHECK(dp->icmp_ip.ip_p);
 297                         (void)snprintf(buf, sizeof(buf),
 298                             "%s protocol %d unreachable",
 299                             ipaddr_string(&dp->icmp_ip.ip_dst),
 300                             dp->icmp_ip.ip_p);
 301                         break;
 302
 303                 case ICMP_UNREACH_PORT:
 304                         TCHECK(dp->icmp_ip.ip_p);
 305                         oip = &dp->icmp_ip;
 306                         hlen = IP_HL(oip) * 4;
 307                         ouh = (struct udphdr *)(((u_char *)oip) + hlen);
 308                         dport = ntohs(ouh->uh_dport);
 309                         switch (oip->ip_p) {
 310
 311                         case IPPROTO_TCP:
 312                                 (void)snprintf(buf, sizeof(buf),
 313                                         "%s tcp port %s unreachable",
 314                                         ipaddr_string(&oip->ip_dst),
 315                                         tcpport_string(dport));
 316                                 break;
 317
 318                         case IPPROTO_UDP:
 319                                 (void)snprintf(buf, sizeof(buf),
 320                                         "%s udp port %s unreachable",
 321                                         ipaddr_string(&oip->ip_dst),
 322                                         udpport_string(dport));
 323                                 break;
 324
 325                         default:
 326                                 (void)snprintf(buf, sizeof(buf),
 327                                         "%s protocol %d port %d unreachable",
 328                                         ipaddr_string(&oip->ip_dst),
 329                                         oip->ip_p, dport);
 330                                 break;
 331                         }
 332                         break;
 333
 334                 case ICMP_UNREACH_NEEDFRAG:
 335                     {
 336                         register const struct mtu_discovery *mp;
 337                         mp = (struct mtu_discovery *)&dp->icmp_void;
 338                         mtu = EXTRACT_16BITS(&mp->nexthopmtu);
 339                         if (mtu) {
 340                                 (void)snprintf(buf, sizeof(buf),
 341                                     "%s unreachable - need to frag (mtu %d)",
 342                                     ipaddr_string(&dp->icmp_ip.ip_dst), mtu);
 343                         } else {
 344                                 (void)snprintf(buf, sizeof(buf),
 345                                     "%s unreachable - need to frag",
 346                                     ipaddr_string(&dp->icmp_ip.ip_dst));
 347                         }
 348                     }
 349                         break;
 350
 351                 default:
 352                         fmt = tok2str(unreach2str, "#%d %%s unreachable",
 353                             dp->icmp_code);
 354                         (void)snprintf(buf, sizeof(buf), fmt,
 355                             ipaddr_string(&dp->icmp_ip.ip_dst));
 356                         break;
 357                 }
 358                 break;
 359
 360         case ICMP_REDIRECT:
 361                 TCHECK(dp->icmp_ip.ip_dst);
 362                 fmt = tok2str(type2str, "redirect-#%d %%s to net %%s",
 363                     dp->icmp_code);
 364                 (void)snprintf(buf, sizeof(buf), fmt,
 365                     ipaddr_string(&dp->icmp_ip.ip_dst),
 366                     ipaddr_string(&dp->icmp_gwaddr));
 367                 break;
 368
 369         case ICMP_ROUTERADVERT:
 370             {
 371                 register const struct ih_rdiscovery *ihp;
 372                 register const struct id_rdiscovery *idp;
 373                 u_int lifetime, num, size;
 374
 375                 (void)snprintf(buf, sizeof(buf), "router advertisement");
 376                 cp = buf + strlen(buf);
 377
 378                 ihp = (struct ih_rdiscovery *)&dp->icmp_void;
 379                 TCHECK(*ihp);
 380                 (void)strncpy(cp, " lifetime ", sizeof(buf) - (cp - buf));
 381                 cp = buf + strlen(buf);
 382                 lifetime = EXTRACT_16BITS(&ihp->ird_lifetime);
 383                 if (lifetime < 60) {
 384                         (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u",
 385                             lifetime);
 386                 } else if (lifetime < 60 * 60) {
 387                         (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u:%02u",
 388                             lifetime / 60, lifetime % 60);
 389                 } else {
 390                         (void)snprintf(cp, sizeof(buf) - (cp - buf),
 391                             "%u:%02u:%02u",
 392                             lifetime / 3600,
 393                             (lifetime % 3600) / 60,
 394                             lifetime % 60);
 395                 }
 396                 cp = buf + strlen(buf);
 397
 398                 num = ihp->ird_addrnum;
 399                 (void)snprintf(cp, sizeof(buf) - (cp - buf), " %d:", num);
 400                 cp = buf + strlen(buf);
 401
 402                 size = ihp->ird_addrsiz;
 403                 if (size != 2) {
 404                         (void)snprintf(cp, sizeof(buf) - (cp - buf),
 405                             " [size %d]", size);
 406                         break;
 407                 }
 408                 idp = (struct id_rdiscovery *)&dp->icmp_data;
 409                 while (num-- > 0) {
 410                         TCHECK(*idp);
 411                         (void)snprintf(cp, sizeof(buf) - (cp - buf), " {%s %u}",
 412                             ipaddr_string(&idp->ird_addr),
 413                             EXTRACT_32BITS(&idp->ird_pref));
 414                         cp = buf + strlen(buf);
 415                         ++idp;
 416                 }
 417             }
 418                 break;
 419
 420         case ICMP_TIMXCEED:
 421                 TCHECK(dp->icmp_ip.ip_dst);
 422                 switch (dp->icmp_code) {
 423
 424                 case ICMP_TIMXCEED_INTRANS:
 425                         str = "time exceeded in-transit";
 426                         break;
 427
 428                 case ICMP_TIMXCEED_REASS:
 429                         str = "ip reassembly time exceeded";
 430                         break;
 431
 432                 default:
 433                         (void)snprintf(buf, sizeof(buf), "time exceeded-#%d",
 434                             dp->icmp_code);
 435                         break;
 436                 }
 437                 break;
 438
 439         case ICMP_PARAMPROB:
 440                 if (dp->icmp_code)
 441                         (void)snprintf(buf, sizeof(buf),
 442                             "parameter problem - code %d", dp->icmp_code);
 443                 else {
 444                         TCHECK(dp->icmp_pptr);
 445                         (void)snprintf(buf, sizeof(buf),
 446                             "parameter problem - octet %d", dp->icmp_pptr);
 447                 }
 448                 break;
 449
 450         case ICMP_MASKREPLY:
 451                 TCHECK(dp->icmp_mask);
 452                 (void)snprintf(buf, sizeof(buf), "address mask is 0x%08x",
 453                     (unsigned)ntohl(dp->icmp_mask));
 454                 break;
 455
 456         case ICMP_TSTAMP:
 457                 TCHECK(dp->icmp_seq);
 458                 (void)snprintf(buf, sizeof(buf),
 459                     "time stamp query id %u seq %u",
 460                     (unsigned)ntohs(dp->icmp_id),
 461                     (unsigned)ntohs(dp->icmp_seq));
 462                 break;
 463
 464         case ICMP_TSTAMPREPLY:
 465                 TCHECK(dp->icmp_ttime);
 466                 (void)snprintf(buf, sizeof(buf),
 467                     "time stamp reply id %u seq %u : org 0x%lx recv 0x%lx xmit 0x%lx",
 468                     (unsigned)ntohs(dp->icmp_id),
 469                     (unsigned)ntohs(dp->icmp_seq),
 470                     (unsigned long)ntohl(dp->icmp_otime),
 471                     (unsigned long)ntohl(dp->icmp_rtime),
 472                     (unsigned long)ntohl(dp->icmp_ttime));
 473                 break;
 474
 475         default:
 476                 str = tok2str(icmp2str, "type-#%d", dp->icmp_type);
 477                 break;
 478         }
 479         (void)printf("icmp: %s", str);
 480         if (vflag) {
 481                 if (TTEST2(*bp, plen)) {
 482                         if (in_cksum((u_short*)dp, plen, 0))
 483                                 printf(" (wrong icmp csum)");
 484                 }
 485         }
 486         if (vflag > 1 && !ICMP_INFOTYPE(dp->icmp_type)) {
 487                 bp += 8;
 488                 (void)printf(" for ");
 489                 ip = (struct ip *)bp;
 490                 snaplen = snapend - bp;
 491                 ip_print(bp, ntohs(ip->ip_len));
 492         }
 493         return;
 494 trunc:
 495         fputs("[|icmp]", stdout);
 496 }