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 1.60 2001-06-28 19:53:42 itojun 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 struct mbuf;
  36 struct rtentry;
  37
  38 #include <netinet/in.h>
  39
  40 #include <stdio.h>
  41 #include <string.h>
  42 #include <netdb.h>              /* for MAXHOSTNAMELEN on some platforms */
  43
  44 #include "interface.h"
  45 #include "addrtoname.h"
  46 #include "extract.h"                    /* must come after interface.h */
  47
  48 #include "ip.h"
  49 #include "udp.h"
  50
  51 /*
  52  * Interface Control Message Protocol Definitions.
  53  * Per RFC 792, September 1981.
  54  */
  55
  56 /*
  57  * Structure of an icmp header.
  58  */
  59 struct icmp {
  60         u_int8_t  icmp_type;            /* type of message, see below */
  61         u_int8_t  icmp_code;            /* type sub code */
  62         u_int16_t icmp_cksum;           /* ones complement cksum of struct */
  63         union {
  64                 u_int8_t ih_pptr;                       /* ICMP_PARAMPROB */
  65                 struct in_addr ih_gwaddr;       /* ICMP_REDIRECT */
  66                 struct ih_idseq {
  67                         u_int16_t icd_id;
  68                         u_int16_t icd_seq;
  69                 } ih_idseq;
  70                 u_int32_t ih_void;
  71
  72                 /* ICMP_UNREACH_NEEDFRAG -- Path MTU Discovery (RFC1191) */
  73                 struct ih_pmtu {
  74                         u_int16_t ipm_void;
  75                         u_int16_t ipm_nextmtu;
  76                 } ih_pmtu;
  77         } icmp_hun;
  78 #define icmp_pptr       icmp_hun.ih_pptr
  79 #define icmp_gwaddr     icmp_hun.ih_gwaddr
  80 #define icmp_id         icmp_hun.ih_idseq.icd_id
  81 #define icmp_seq        icmp_hun.ih_idseq.icd_seq
  82 #define icmp_void       icmp_hun.ih_void
  83 #define icmp_pmvoid     icmp_hun.ih_pmtu.ipm_void
  84 #define icmp_nextmtu    icmp_hun.ih_pmtu.ipm_nextmtu
  85         union {
  86                 struct id_ts {
  87                         u_int32_t its_otime;
  88                         u_int32_t its_rtime;
  89                         u_int32_t its_ttime;
  90                 } id_ts;
  91                 struct id_ip  {
  92                         struct ip idi_ip;
  93                         /* options and then 64 bits of data */
  94                 } id_ip;
  95                 u_int32_t id_mask;
  96                 u_int8_t id_data[1];
  97         } icmp_dun;
  98 #define icmp_otime      icmp_dun.id_ts.its_otime
  99 #define icmp_rtime      icmp_dun.id_ts.its_rtime
 100 #define icmp_ttime      icmp_dun.id_ts.its_ttime
 101 #define icmp_ip         icmp_dun.id_ip.idi_ip
 102 #define icmp_mask       icmp_dun.id_mask
 103 #define icmp_data       icmp_dun.id_data
 104 };
 105
 106 /*
 107  * Lower bounds on packet lengths for various types.
 108  * For the error advice packets must first insure that the
 109  * packet is large enought to contain the returned ip header.
 110  * Only then can we do the check to see if 64 bits of packet
 111  * data have been returned, since we need to check the returned
 112  * ip header length.
 113  */
 114 #define ICMP_MINLEN     8                               /* abs minimum */
 115 #define ICMP_TSLEN      (8 + 3 * sizeof (u_int32_t))    /* timestamp */
 116 #define ICMP_MASKLEN    12                              /* address mask */
 117 #define ICMP_ADVLENMIN  (8 + sizeof (struct ip) + 8)    /* min */
 118 #define ICMP_ADVLEN(p)  (8 + (IP_HL(&(p)->icmp_ip) << 2) + 8)
 119         /* N.B.: must separately check that ip_hl >= 5 */
 120
 121 /*
 122  * Definition of type and code field values.
 123  */
 124 #define ICMP_ECHOREPLY          0               /* echo reply */
 125 #define ICMP_UNREACH            3               /* dest unreachable, codes: */
 126 #define         ICMP_UNREACH_NET        0               /* bad net */
 127 #define         ICMP_UNREACH_HOST       1               /* bad host */
 128 #define         ICMP_UNREACH_PROTOCOL   2               /* bad protocol */
 129 #define         ICMP_UNREACH_PORT       3               /* bad port */
 130 #define         ICMP_UNREACH_NEEDFRAG   4               /* IP_DF caused drop */
 131 #define         ICMP_UNREACH_SRCFAIL    5               /* src route failed */
 132 #define         ICMP_UNREACH_NET_UNKNOWN 6              /* unknown net */
 133 #define         ICMP_UNREACH_HOST_UNKNOWN 7             /* unknown host */
 134 #define         ICMP_UNREACH_ISOLATED   8               /* src host isolated */
 135 #define         ICMP_UNREACH_NET_PROHIB 9               /* prohibited access */
 136 #define         ICMP_UNREACH_HOST_PROHIB 10             /* ditto */
 137 #define         ICMP_UNREACH_TOSNET     11              /* bad tos for net */
 138 #define         ICMP_UNREACH_TOSHOST    12              /* bad tos for host */
 139 #define ICMP_SOURCEQUENCH       4               /* packet lost, slow down */
 140 #define ICMP_REDIRECT           5               /* shorter route, codes: */
 141 #define         ICMP_REDIRECT_NET       0               /* for network */
 142 #define         ICMP_REDIRECT_HOST      1               /* for host */
 143 #define         ICMP_REDIRECT_TOSNET    2               /* for tos and net */
 144 #define         ICMP_REDIRECT_TOSHOST   3               /* for tos and host */
 145 #define ICMP_ECHO               8               /* echo service */
 146 #define ICMP_ROUTERADVERT       9               /* router advertisement */
 147 #define ICMP_ROUTERSOLICIT      10              /* router solicitation */
 148 #define ICMP_TIMXCEED           11              /* time exceeded, code: */
 149 #define         ICMP_TIMXCEED_INTRANS   0               /* ttl==0 in transit */
 150 #define         ICMP_TIMXCEED_REASS     1               /* ttl==0 in reass */
 151 #define ICMP_PARAMPROB          12              /* ip header bad */
 152 #define         ICMP_PARAMPROB_OPTABSENT 1              /* req. opt. absent */
 153 #define ICMP_TSTAMP             13              /* timestamp request */
 154 #define ICMP_TSTAMPREPLY        14              /* timestamp reply */
 155 #define ICMP_IREQ               15              /* information request */
 156 #define ICMP_IREQREPLY          16              /* information reply */
 157 #define ICMP_MASKREQ            17              /* address mask request */
 158 #define ICMP_MASKREPLY          18              /* address mask reply */
 159
 160 #define ICMP_MAXTYPE            18
 161
 162 #define ICMP_INFOTYPE(type) \
 163         ((type) == ICMP_ECHOREPLY || (type) == ICMP_ECHO || \
 164         (type) == ICMP_ROUTERADVERT || (type) == ICMP_ROUTERSOLICIT || \
 165         (type) == ICMP_TSTAMP || (type) == ICMP_TSTAMPREPLY || \
 166         (type) == ICMP_IREQ || (type) == ICMP_IREQREPLY || \
 167         (type) == ICMP_MASKREQ || (type) == ICMP_MASKREPLY)
 168 /* rfc1700 */
 169 #ifndef ICMP_UNREACH_NET_UNKNOWN
 170 #define ICMP_UNREACH_NET_UNKNOWN        6       /* destination net unknown */
 171 #endif
 172 #ifndef ICMP_UNREACH_HOST_UNKNOWN
 173 #define ICMP_UNREACH_HOST_UNKNOWN       7       /* destination host unknown */
 174 #endif
 175 #ifndef ICMP_UNREACH_ISOLATED
 176 #define ICMP_UNREACH_ISOLATED           8       /* source host isolated */
 177 #endif
 178 #ifndef ICMP_UNREACH_NET_PROHIB
 179 #define ICMP_UNREACH_NET_PROHIB         9       /* admin prohibited net */
 180 #endif
 181 #ifndef ICMP_UNREACH_HOST_PROHIB
 182 #define ICMP_UNREACH_HOST_PROHIB        10      /* admin prohibited host */
 183 #endif
 184 #ifndef ICMP_UNREACH_TOSNET
 185 #define ICMP_UNREACH_TOSNET             11      /* tos prohibited net */
 186 #endif
 187 #ifndef ICMP_UNREACH_TOSHOST
 188 #define ICMP_UNREACH_TOSHOST            12      /* tos prohibited host */
 189 #endif
 190
 191 /* rfc1716 */
 192 #ifndef ICMP_UNREACH_FILTER_PROHIB
 193 #define ICMP_UNREACH_FILTER_PROHIB      13      /* admin prohibited filter */
 194 #endif
 195 #ifndef ICMP_UNREACH_HOST_PRECEDENCE
 196 #define ICMP_UNREACH_HOST_PRECEDENCE    14      /* host precedence violation */
 197 #endif
 198 #ifndef ICMP_UNREACH_PRECEDENCE_CUTOFF
 199 #define ICMP_UNREACH_PRECEDENCE_CUTOFF  15      /* precedence cutoff */
 200 #endif
 201
 202 /* Most of the icmp types */
 203 static struct tok icmp2str[] = {
 204         { ICMP_ECHOREPLY,               "echo reply" },
 205         { ICMP_SOURCEQUENCH,            "source quench" },
 206         { ICMP_ECHO,                    "echo request" },
 207         { ICMP_ROUTERSOLICIT,           "router solicitation" },
 208         { ICMP_TSTAMP,                  "time stamp request" },
 209         { ICMP_TSTAMPREPLY,             "time stamp reply" },
 210         { ICMP_IREQ,                    "information request" },
 211         { ICMP_IREQREPLY,               "information reply" },
 212         { ICMP_MASKREQ,                 "address mask request" },
 213         { 0,                            NULL }
 214 };
 215
 216 /* Formats for most of the ICMP_UNREACH codes */
 217 static struct tok unreach2str[] = {
 218         { ICMP_UNREACH_NET,             "net %s unreachable" },
 219         { ICMP_UNREACH_HOST,            "host %s unreachable" },
 220         { ICMP_UNREACH_SRCFAIL,
 221             "%s unreachable - source route failed" },
 222         { ICMP_UNREACH_NET_UNKNOWN,     "net %s unreachable - unknown" },
 223         { ICMP_UNREACH_HOST_UNKNOWN,    "host %s unreachable - unknown" },
 224         { ICMP_UNREACH_ISOLATED,
 225             "%s unreachable - source host isolated" },
 226         { ICMP_UNREACH_NET_PROHIB,
 227             "net %s unreachable - admin prohibited" },
 228         { ICMP_UNREACH_HOST_PROHIB,
 229             "host %s unreachable - admin prohibited" },
 230         { ICMP_UNREACH_TOSNET,
 231             "net %s unreachable - tos prohibited" },
 232         { ICMP_UNREACH_TOSHOST,
 233             "host %s unreachable - tos prohibited" },
 234         { ICMP_UNREACH_FILTER_PROHIB,
 235             "host %s unreachable - admin prohibited filter" },
 236         { ICMP_UNREACH_HOST_PRECEDENCE,
 237             "host %s unreachable - host precedence violation" },
 238         { ICMP_UNREACH_PRECEDENCE_CUTOFF,
 239             "host %s unreachable - precedence cutoff" },
 240         { 0,                            NULL }
 241 };
 242
 243 /* Formats for the ICMP_REDIRECT codes */
 244 static struct tok type2str[] = {
 245         { ICMP_REDIRECT_NET,            "redirect %s to net %s" },
 246         { ICMP_REDIRECT_HOST,           "redirect %s to host %s" },
 247         { ICMP_REDIRECT_TOSNET,         "redirect-tos %s to net %s" },
 248         { ICMP_REDIRECT_TOSHOST,        "redirect-tos %s to net %s" },
 249         { 0,                            NULL }
 250 };
 251
 252 /* rfc1191 */
 253 struct mtu_discovery {
 254         u_int16_t unused;
 255         u_int16_t nexthopmtu;
 256 };
 257
 258 /* rfc1256 */
 259 struct ih_rdiscovery {
 260         u_int8_t ird_addrnum;
 261         u_int8_t ird_addrsiz;
 262         u_int16_t ird_lifetime;
 263 };
 264
 265 struct id_rdiscovery {
 266         u_int32_t ird_addr;
 267         u_int32_t ird_pref;
 268 };
 269
 270 void
 271 icmp_print(const u_char *bp, u_int plen, const u_char *bp2)
 272 {
 273         char *cp;
 274         const struct icmp *dp;
 275         const struct ip *ip;
 276         const char *str, *fmt;
 277         const struct ip *oip;
 278         const struct udphdr *ouh;
 279         u_int hlen, dport, mtu;
 280         char buf[MAXHOSTNAMELEN + 100];
 281
 282         dp = (struct icmp *)bp;
 283         ip = (struct ip *)bp2;
 284         str = buf;
 285
 286         TCHECK(dp->icmp_code);
 287         switch (dp->icmp_type) {
 288
 289         case ICMP_UNREACH:
 290                 TCHECK(dp->icmp_ip.ip_dst);
 291                 switch (dp->icmp_code) {
 292
 293                 case ICMP_UNREACH_PROTOCOL:
 294                         TCHECK(dp->icmp_ip.ip_p);
 295                         (void)snprintf(buf, sizeof(buf),
 296                             "%s protocol %d unreachable",
 297                             ipaddr_string(&dp->icmp_ip.ip_dst),
 298                             dp->icmp_ip.ip_p);
 299                         break;
 300
 301                 case ICMP_UNREACH_PORT:
 302                         TCHECK(dp->icmp_ip.ip_p);
 303                         oip = &dp->icmp_ip;
 304                         hlen = IP_HL(oip) * 4;
 305                         ouh = (struct udphdr *)(((u_char *)oip) + hlen);
 306                         dport = ntohs(ouh->uh_dport);
 307                         switch (oip->ip_p) {
 308
 309                         case IPPROTO_TCP:
 310                                 (void)snprintf(buf, sizeof(buf),
 311                                         "%s tcp port %s unreachable",
 312                                         ipaddr_string(&oip->ip_dst),
 313                                         tcpport_string(dport));
 314                                 break;
 315
 316                         case IPPROTO_UDP:
 317                                 (void)snprintf(buf, sizeof(buf),
 318                                         "%s udp port %s unreachable",
 319                                         ipaddr_string(&oip->ip_dst),
 320                                         udpport_string(dport));
 321                                 break;
 322
 323                         default:
 324                                 (void)snprintf(buf, sizeof(buf),
 325                                         "%s protocol %d port %d unreachable",
 326                                         ipaddr_string(&oip->ip_dst),
 327                                         oip->ip_p, dport);
 328                                 break;
 329                         }
 330                         break;
 331
 332                 case ICMP_UNREACH_NEEDFRAG:
 333                     {
 334                         register const struct mtu_discovery *mp;
 335                         mp = (struct mtu_discovery *)&dp->icmp_void;
 336                         mtu = EXTRACT_16BITS(&mp->nexthopmtu);
 337                         if (mtu) {
 338                                 (void)snprintf(buf, sizeof(buf),
 339                                     "%s unreachable - need to frag (mtu %d)",
 340                                     ipaddr_string(&dp->icmp_ip.ip_dst), mtu);
 341                         } else {
 342                                 (void)snprintf(buf, sizeof(buf),
 343                                     "%s unreachable - need to frag",
 344                                     ipaddr_string(&dp->icmp_ip.ip_dst));
 345                         }
 346                     }
 347                         break;
 348
 349                 default:
 350                         fmt = tok2str(unreach2str, "#%d",
 351                             dp->icmp_code);
 352                         (void)snprintf(buf, sizeof(buf), "%s %s unreachable",
 353                             fmt, ipaddr_string(&dp->icmp_ip.ip_dst));
 354                         break;
 355                 }
 356                 break;
 357
 358         case ICMP_REDIRECT:
 359                 TCHECK(dp->icmp_ip.ip_dst);
 360                 fmt = tok2str(type2str, "#%d", dp->icmp_code);
 361                 (void)snprintf(buf, sizeof(buf), "redirect-%s %s to net %s",
 362                     fmt, ipaddr_string(&dp->icmp_ip.ip_dst),
 363                     ipaddr_string(&dp->icmp_gwaddr));
 364                 break;
 365
 366         case ICMP_ROUTERADVERT:
 367             {
 368                 register const struct ih_rdiscovery *ihp;
 369                 register const struct id_rdiscovery *idp;
 370                 u_int lifetime, num, size;
 371
 372                 (void)snprintf(buf, sizeof(buf), "router advertisement");
 373                 cp = buf + strlen(buf);
 374
 375                 ihp = (struct ih_rdiscovery *)&dp->icmp_void;
 376                 TCHECK(*ihp);
 377                 (void)snprintf(cp, sizeof(buf) - (cp - buf), " lifetime ");
 378                 cp = buf + strlen(buf);
 379                 lifetime = EXTRACT_16BITS(&ihp->ird_lifetime);
 380                 if (lifetime < 60) {
 381                         (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u",
 382                             lifetime);
 383                 } else if (lifetime < 60 * 60) {
 384                         (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u:%02u",
 385                             lifetime / 60, lifetime % 60);
 386                 } else {
 387                         (void)snprintf(cp, sizeof(buf) - (cp - buf),
 388                             "%u:%02u:%02u",
 389                             lifetime / 3600,
 390                             (lifetime % 3600) / 60,
 391                             lifetime % 60);
 392                 }
 393                 cp = buf + strlen(buf);
 394
 395                 num = ihp->ird_addrnum;
 396                 (void)snprintf(cp, sizeof(buf) - (cp - buf), " %d:", num);
 397                 cp = buf + strlen(buf);
 398
 399                 size = ihp->ird_addrsiz;
 400                 if (size != 2) {
 401                         (void)snprintf(cp, sizeof(buf) - (cp - buf),
 402                             " [size %d]", size);
 403                         break;
 404                 }
 405                 idp = (struct id_rdiscovery *)&dp->icmp_data;
 406                 while (num-- > 0) {
 407                         TCHECK(*idp);
 408                         (void)snprintf(cp, sizeof(buf) - (cp - buf), " {%s %u}",
 409                             ipaddr_string(&idp->ird_addr),
 410                             EXTRACT_32BITS(&idp->ird_pref));
 411                         cp = buf + strlen(buf);
 412                         ++idp;
 413                 }
 414             }
 415                 break;
 416
 417         case ICMP_TIMXCEED:
 418                 TCHECK(dp->icmp_ip.ip_dst);
 419                 switch (dp->icmp_code) {
 420
 421                 case ICMP_TIMXCEED_INTRANS:
 422                         str = "time exceeded in-transit";
 423                         break;
 424
 425                 case ICMP_TIMXCEED_REASS:
 426                         str = "ip reassembly time exceeded";
 427                         break;
 428
 429                 default:
 430                         (void)snprintf(buf, sizeof(buf), "time exceeded-#%d",
 431                             dp->icmp_code);
 432                         break;
 433                 }
 434                 break;
 435
 436         case ICMP_PARAMPROB:
 437                 if (dp->icmp_code)
 438                         (void)snprintf(buf, sizeof(buf),
 439                             "parameter problem - code %d", dp->icmp_code);
 440                 else {
 441                         TCHECK(dp->icmp_pptr);
 442                         (void)snprintf(buf, sizeof(buf),
 443                             "parameter problem - octet %d", dp->icmp_pptr);
 444                 }
 445                 break;
 446
 447         case ICMP_MASKREPLY:
 448                 TCHECK(dp->icmp_mask);
 449                 (void)snprintf(buf, sizeof(buf), "address mask is 0x%08x",
 450                     (unsigned)ntohl(dp->icmp_mask));
 451                 break;
 452
 453         case ICMP_TSTAMP:
 454                 TCHECK(dp->icmp_seq);
 455                 (void)snprintf(buf, sizeof(buf),
 456                     "time stamp query id %u seq %u",
 457                     (unsigned)ntohs(dp->icmp_id),
 458                     (unsigned)ntohs(dp->icmp_seq));
 459                 break;
 460
 461         case ICMP_TSTAMPREPLY:
 462                 TCHECK(dp->icmp_ttime);
 463                 (void)snprintf(buf, sizeof(buf),
 464                     "time stamp reply id %u seq %u : org 0x%lx recv 0x%lx xmit 0x%lx",
 465                     (unsigned)ntohs(dp->icmp_id),
 466                     (unsigned)ntohs(dp->icmp_seq),
 467                     (unsigned long)ntohl(dp->icmp_otime),
 468                     (unsigned long)ntohl(dp->icmp_rtime),
 469                     (unsigned long)ntohl(dp->icmp_ttime));
 470                 break;
 471
 472         default:
 473                 str = tok2str(icmp2str, "type-#%d", dp->icmp_type);
 474                 break;
 475         }
 476         (void)printf("icmp: %s", str);
 477         if (vflag) {
 478                 if (TTEST2(*bp, plen)) {
 479                         if (in_cksum((u_short*)dp, plen, 0))
 480                                 printf(" (wrong icmp csum)");
 481                 }
 482         }
 483         if (vflag > 1 && !ICMP_INFOTYPE(dp->icmp_type)) {
 484                 bp += 8;
 485                 (void)printf(" for ");
 486                 ip = (struct ip *)bp;
 487                 snaplen = snapend - bp;
 488                 ip_print(bp, ntohs(ip->ip_len));
 489         }
 490         return;
 491 trunc:
 492         fputs("[|icmp]", stdout);
 493 }