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 1.54 2000-10-03 02:54:58 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
  43 #include "interface.h"
  44 #include "addrtoname.h"
  45 #include "extract.h"                    /* must come after interface.h */
  46
  47 #include "ip.h"
  48 #include "udp.h"
  49
  50 /*
  51  * Interface Control Message Protocol Definitions.
  52  * Per RFC 792, September 1981.
  53  */
  54
  55 /*
  56  * Structure of an icmp header.
  57  */
  58 struct icmp {
  59         u_char  icmp_type;              /* type of message, see below */
  60         u_char  icmp_code;              /* type sub code */
  61         u_short icmp_cksum;             /* ones complement cksum of struct */
  62         union {
  63                 u_char ih_pptr;                 /* ICMP_PARAMPROB */
  64                 struct in_addr ih_gwaddr;       /* ICMP_REDIRECT */
  65                 struct ih_idseq {
  66                         u_short icd_id;
  67                         u_short icd_seq;
  68                 } ih_idseq;
  69                 int ih_void;
  70
  71                 /* ICMP_UNREACH_NEEDFRAG -- Path MTU Discovery (RFC1191) */
  72                 struct ih_pmtu {
  73                         u_short ipm_void;
  74                         u_short ipm_nextmtu;
  75                 } ih_pmtu;
  76         } icmp_hun;
  77 #define icmp_pptr       icmp_hun.ih_pptr
  78 #define icmp_gwaddr     icmp_hun.ih_gwaddr
  79 #define icmp_id         icmp_hun.ih_idseq.icd_id
  80 #define icmp_seq        icmp_hun.ih_idseq.icd_seq
  81 #define icmp_void       icmp_hun.ih_void
  82 #define icmp_pmvoid     icmp_hun.ih_pmtu.ipm_void
  83 #define icmp_nextmtu    icmp_hun.ih_pmtu.ipm_nextmtu
  84         union {
  85                 struct id_ts {
  86                         u_int its_otime;
  87                         u_int its_rtime;
  88                         u_int its_ttime;
  89                 } id_ts;
  90                 struct id_ip  {
  91                         struct ip idi_ip;
  92                         /* options and then 64 bits of data */
  93                 } id_ip;
  94                 u_int   id_mask;
  95                 char    id_data[1];
  96         } icmp_dun;
  97 #define icmp_otime      icmp_dun.id_ts.its_otime
  98 #define icmp_rtime      icmp_dun.id_ts.its_rtime
  99 #define icmp_ttime      icmp_dun.id_ts.its_ttime
 100 #define icmp_ip         icmp_dun.id_ip.idi_ip
 101 #define icmp_mask       icmp_dun.id_mask
 102 #define icmp_data       icmp_dun.id_data
 103 };
 104
 105 /*
 106  * Lower bounds on packet lengths for various types.
 107  * For the error advice packets must first insure that the
 108  * packet is large enought to contain the returned ip header.
 109  * Only then can we do the check to see if 64 bits of packet
 110  * data have been returned, since we need to check the returned
 111  * ip header length.
 112  */
 113 #define ICMP_MINLEN     8                               /* abs minimum */
 114 #define ICMP_TSLEN      (8 + 3 * sizeof (u_int))        /* timestamp */
 115 #define ICMP_MASKLEN    12                              /* address mask */
 116 #define ICMP_ADVLENMIN  (8 + sizeof (struct ip) + 8)    /* min */
 117 #define ICMP_ADVLEN(p)  (8 + (IP_HL(&(p)->icmp_ip) << 2) + 8)
 118         /* N.B.: must separately check that ip_hl >= 5 */
 119
 120 /*
 121  * Definition of type and code field values.
 122  */
 123 #define ICMP_ECHOREPLY          0               /* echo reply */
 124 #define ICMP_UNREACH            3               /* dest unreachable, codes: */
 125 #define         ICMP_UNREACH_NET        0               /* bad net */
 126 #define         ICMP_UNREACH_HOST       1               /* bad host */
 127 #define         ICMP_UNREACH_PROTOCOL   2               /* bad protocol */
 128 #define         ICMP_UNREACH_PORT       3               /* bad port */
 129 #define         ICMP_UNREACH_NEEDFRAG   4               /* IP_DF caused drop */
 130 #define         ICMP_UNREACH_SRCFAIL    5               /* src route failed */
 131 #define         ICMP_UNREACH_NET_UNKNOWN 6              /* unknown net */
 132 #define         ICMP_UNREACH_HOST_UNKNOWN 7             /* unknown host */
 133 #define         ICMP_UNREACH_ISOLATED   8               /* src host isolated */
 134 #define         ICMP_UNREACH_NET_PROHIB 9               /* prohibited access */
 135 #define         ICMP_UNREACH_HOST_PROHIB 10             /* ditto */
 136 #define         ICMP_UNREACH_TOSNET     11              /* bad tos for net */
 137 #define         ICMP_UNREACH_TOSHOST    12              /* bad tos for host */
 138 #define ICMP_SOURCEQUENCH       4               /* packet lost, slow down */
 139 #define ICMP_REDIRECT           5               /* shorter route, codes: */
 140 #define         ICMP_REDIRECT_NET       0               /* for network */
 141 #define         ICMP_REDIRECT_HOST      1               /* for host */
 142 #define         ICMP_REDIRECT_TOSNET    2               /* for tos and net */
 143 #define         ICMP_REDIRECT_TOSHOST   3               /* for tos and host */
 144 #define ICMP_ECHO               8               /* echo service */
 145 #define ICMP_ROUTERADVERT       9               /* router advertisement */
 146 #define ICMP_ROUTERSOLICIT      10              /* router solicitation */
 147 #define ICMP_TIMXCEED           11              /* time exceeded, code: */
 148 #define         ICMP_TIMXCEED_INTRANS   0               /* ttl==0 in transit */
 149 #define         ICMP_TIMXCEED_REASS     1               /* ttl==0 in reass */
 150 #define ICMP_PARAMPROB          12              /* ip header bad */
 151 #define         ICMP_PARAMPROB_OPTABSENT 1              /* req. opt. absent */
 152 #define ICMP_TSTAMP             13              /* timestamp request */
 153 #define ICMP_TSTAMPREPLY        14              /* timestamp reply */
 154 #define ICMP_IREQ               15              /* information request */
 155 #define ICMP_IREQREPLY          16              /* information reply */
 156 #define ICMP_MASKREQ            17              /* address mask request */
 157 #define ICMP_MASKREPLY          18              /* address mask reply */
 158
 159 #define ICMP_MAXTYPE            18
 160
 161 #define ICMP_INFOTYPE(type) \
 162         ((type) == ICMP_ECHOREPLY || (type) == ICMP_ECHO || \
 163         (type) == ICMP_ROUTERADVERT || (type) == ICMP_ROUTERSOLICIT || \
 164         (type) == ICMP_TSTAMP || (type) == ICMP_TSTAMPREPLY || \
 165         (type) == ICMP_IREQ || (type) == ICMP_IREQREPLY || \
 166         (type) == ICMP_MASKREQ || (type) == ICMP_MASKREPLY)
 167 /* rfc1700 */
 168 #ifndef ICMP_UNREACH_NET_UNKNOWN
 169 #define ICMP_UNREACH_NET_UNKNOWN        6       /* destination net unknown */
 170 #endif
 171 #ifndef ICMP_UNREACH_HOST_UNKNOWN
 172 #define ICMP_UNREACH_HOST_UNKNOWN       7       /* destination host unknown */
 173 #endif
 174 #ifndef ICMP_UNREACH_ISOLATED
 175 #define ICMP_UNREACH_ISOLATED           8       /* source host isolated */
 176 #endif
 177 #ifndef ICMP_UNREACH_NET_PROHIB
 178 #define ICMP_UNREACH_NET_PROHIB         9       /* admin prohibited net */
 179 #endif
 180 #ifndef ICMP_UNREACH_HOST_PROHIB
 181 #define ICMP_UNREACH_HOST_PROHIB        10      /* admin prohibited host */
 182 #endif
 183 #ifndef ICMP_UNREACH_TOSNET
 184 #define ICMP_UNREACH_TOSNET             11      /* tos prohibited net */
 185 #endif
 186 #ifndef ICMP_UNREACH_TOSHOST
 187 #define ICMP_UNREACH_TOSHOST            12      /* tos prohibited host */
 188 #endif
 189
 190 /* rfc1716 */
 191 #ifndef ICMP_UNREACH_FILTER_PROHIB
 192 #define ICMP_UNREACH_FILTER_PROHIB      13      /* admin prohibited filter */
 193 #endif
 194 #ifndef ICMP_UNREACH_HOST_PRECEDENCE
 195 #define ICMP_UNREACH_HOST_PRECEDENCE    14      /* host precedence violation */
 196 #endif
 197 #ifndef ICMP_UNREACH_PRECEDENCE_CUTOFF
 198 #define ICMP_UNREACH_PRECEDENCE_CUTOFF  15      /* precedence cutoff */
 199 #endif
 200
 201 /* Most of the icmp types */
 202 static struct tok icmp2str[] = {
 203         { ICMP_ECHOREPLY,               "echo reply" },
 204         { ICMP_SOURCEQUENCH,            "source quench" },
 205         { ICMP_ECHO,                    "echo request" },
 206         { ICMP_ROUTERSOLICIT,           "router solicitation" },
 207         { ICMP_TSTAMP,                  "time stamp request" },
 208         { ICMP_TSTAMPREPLY,             "time stamp reply" },
 209         { ICMP_IREQ,                    "information request" },
 210         { ICMP_IREQREPLY,               "information reply" },
 211         { ICMP_MASKREQ,                 "address mask request" },
 212         { 0,                            NULL }
 213 };
 214
 215 /* Formats for most of the ICMP_UNREACH codes */
 216 static struct tok unreach2str[] = {
 217         { ICMP_UNREACH_NET,             "net %s unreachable" },
 218         { ICMP_UNREACH_HOST,            "host %s unreachable" },
 219         { ICMP_UNREACH_SRCFAIL,
 220             "%s unreachable - source route failed" },
 221         { ICMP_UNREACH_NET_UNKNOWN,     "net %s unreachable - unknown" },
 222         { ICMP_UNREACH_HOST_UNKNOWN,    "host %s unreachable - unknown" },
 223         { ICMP_UNREACH_ISOLATED,
 224             "%s unreachable - source host isolated" },
 225         { ICMP_UNREACH_NET_PROHIB,
 226             "net %s unreachable - admin prohibited" },
 227         { ICMP_UNREACH_HOST_PROHIB,
 228             "host %s unreachable - admin prohibited" },
 229         { ICMP_UNREACH_TOSNET,
 230             "net %s unreachable - tos prohibited" },
 231         { ICMP_UNREACH_TOSHOST,
 232             "host %s unreachable - tos prohibited" },
 233         { ICMP_UNREACH_FILTER_PROHIB,
 234             "host %s unreachable - admin prohibited filter" },
 235         { ICMP_UNREACH_HOST_PRECEDENCE,
 236             "host %s unreachable - host precedence violation" },
 237         { ICMP_UNREACH_PRECEDENCE_CUTOFF,
 238             "host %s unreachable - precedence cutoff" },
 239         { 0,                            NULL }
 240 };
 241
 242 /* Formats for the ICMP_REDIRECT codes */
 243 static struct tok type2str[] = {
 244         { ICMP_REDIRECT_NET,            "redirect %s to net %s" },
 245         { ICMP_REDIRECT_HOST,           "redirect %s to host %s" },
 246         { ICMP_REDIRECT_TOSNET,         "redirect-tos %s to net %s" },
 247         { ICMP_REDIRECT_TOSHOST,        "redirect-tos %s to net %s" },
 248         { 0,                            NULL }
 249 };
 250
 251 /* rfc1191 */
 252 struct mtu_discovery {
 253         short unused;
 254         short nexthopmtu;
 255 };
 256
 257 /* rfc1256 */
 258 struct ih_rdiscovery {
 259         u_char ird_addrnum;
 260         u_char ird_addrsiz;
 261         u_short ird_lifetime;
 262 };
 263
 264 struct id_rdiscovery {
 265         u_int32_t ird_addr;
 266         u_int32_t ird_pref;
 267 };
 268
 269 void
 270 icmp_print(register const u_char *bp, u_int plen, register const u_char *bp2)
 271 {
 272         register char *cp;
 273         register const struct icmp *dp;
 274         register const struct ip *ip;
 275         register const char *str, *fmt;
 276         register const struct ip *oip;
 277         register const struct udphdr *ouh;
 278         register u_int hlen, dport, mtu;
 279         char buf[256];
 280
 281         dp = (struct icmp *)bp;
 282         ip = (struct ip *)bp2;
 283         str = buf;
 284
 285 #if 0
 286         (void)printf("%s > %s: ",
 287                 ipaddr_string(&ip->ip_src),
 288                 ipaddr_string(&ip->ip_dst));
 289 #endif
 290
 291         TCHECK(dp->icmp_code);
 292         switch (dp->icmp_type) {
 293
 294         case ICMP_UNREACH:
 295                 TCHECK(dp->icmp_ip.ip_dst);
 296                 switch (dp->icmp_code) {
 297
 298                 case ICMP_UNREACH_PROTOCOL:
 299                         TCHECK(dp->icmp_ip.ip_p);
 300                         (void)snprintf(buf, sizeof(buf),
 301                             "%s protocol %d unreachable",
 302                             ipaddr_string(&dp->icmp_ip.ip_dst),
 303                             dp->icmp_ip.ip_p);
 304                         break;
 305
 306                 case ICMP_UNREACH_PORT:
 307                         TCHECK(dp->icmp_ip.ip_p);
 308                         oip = &dp->icmp_ip;
 309                         hlen = IP_HL(oip) * 4;
 310                         ouh = (struct udphdr *)(((u_char *)oip) + hlen);
 311                         dport = ntohs(ouh->uh_dport);
 312                         switch (oip->ip_p) {
 313
 314                         case IPPROTO_TCP:
 315                                 (void)snprintf(buf, sizeof(buf),
 316                                         "%s tcp port %s unreachable",
 317                                         ipaddr_string(&oip->ip_dst),
 318                                         tcpport_string(dport));
 319                                 break;
 320
 321                         case IPPROTO_UDP:
 322                                 (void)snprintf(buf, sizeof(buf),
 323                                         "%s udp port %s unreachable",
 324                                         ipaddr_string(&oip->ip_dst),
 325                                         udpport_string(dport));
 326                                 break;
 327
 328                         default:
 329                                 (void)snprintf(buf, sizeof(buf),
 330                                         "%s protocol %d port %d unreachable",
 331                                         ipaddr_string(&oip->ip_dst),
 332                                         oip->ip_p, dport);
 333                                 break;
 334                         }
 335                         break;
 336
 337                 case ICMP_UNREACH_NEEDFRAG:
 338                     {
 339                         register const struct mtu_discovery *mp;
 340                         mp = (struct mtu_discovery *)&dp->icmp_void;
 341                         mtu = EXTRACT_16BITS(&mp->nexthopmtu);
 342                         if (mtu) {
 343                                 (void)snprintf(buf, sizeof(buf),
 344                                     "%s unreachable - need to frag (mtu %d)",
 345                                     ipaddr_string(&dp->icmp_ip.ip_dst), mtu);
 346                         } else {
 347                                 (void)snprintf(buf, sizeof(buf),
 348                                     "%s unreachable - need to frag",
 349                                     ipaddr_string(&dp->icmp_ip.ip_dst));
 350                         }
 351                     }
 352                         break;
 353
 354                 default:
 355                         fmt = tok2str(unreach2str, "#%d %%s unreachable",
 356                             dp->icmp_code);
 357                         (void)snprintf(buf, sizeof(buf), fmt,
 358                             ipaddr_string(&dp->icmp_ip.ip_dst));
 359                         break;
 360                 }
 361                 break;
 362
 363         case ICMP_REDIRECT:
 364                 TCHECK(dp->icmp_ip.ip_dst);
 365                 fmt = tok2str(type2str, "redirect-#%d %%s to net %%s",
 366                     dp->icmp_code);
 367                 (void)snprintf(buf, sizeof(buf), fmt,
 368                     ipaddr_string(&dp->icmp_ip.ip_dst),
 369                     ipaddr_string(&dp->icmp_gwaddr));
 370                 break;
 371
 372         case ICMP_ROUTERADVERT:
 373             {
 374                 register const struct ih_rdiscovery *ihp;
 375                 register const struct id_rdiscovery *idp;
 376                 u_int lifetime, num, size;
 377
 378                 (void)snprintf(buf, sizeof(buf), "router advertisement");
 379                 cp = buf + strlen(buf);
 380
 381                 ihp = (struct ih_rdiscovery *)&dp->icmp_void;
 382                 TCHECK(*ihp);
 383                 (void)strncpy(cp, " lifetime ", sizeof(buf) - (cp - buf));
 384                 cp = buf + strlen(buf);
 385                 lifetime = EXTRACT_16BITS(&ihp->ird_lifetime);
 386                 if (lifetime < 60) {
 387                         (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u",
 388                             lifetime);
 389                 } else if (lifetime < 60 * 60) {
 390                         (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u:%02u",
 391                             lifetime / 60, lifetime % 60);
 392                 } else {
 393                         (void)snprintf(cp, sizeof(buf) - (cp - buf),
 394                             "%u:%02u:%02u",
 395                             lifetime / 3600,
 396                             (lifetime % 3600) / 60,
 397                             lifetime % 60);
 398                 }
 399                 cp = buf + strlen(buf);
 400
 401                 num = ihp->ird_addrnum;
 402                 (void)snprintf(cp, sizeof(buf) - (cp - buf), " %d:", num);
 403                 cp = buf + strlen(buf);
 404
 405                 size = ihp->ird_addrsiz;
 406                 if (size != 2) {
 407                         (void)snprintf(cp, sizeof(buf) - (cp - buf),
 408                             " [size %d]", size);
 409                         break;
 410                 }
 411                 idp = (struct id_rdiscovery *)&dp->icmp_data;
 412                 while (num-- > 0) {
 413                         TCHECK(*idp);
 414                         (void)snprintf(cp, sizeof(buf) - (cp - buf), " {%s %u}",
 415                             ipaddr_string(&idp->ird_addr),
 416                             EXTRACT_32BITS(&idp->ird_pref));
 417                         cp = buf + strlen(buf);
 418                         ++idp;
 419                 }
 420             }
 421                 break;
 422
 423         case ICMP_TIMXCEED:
 424                 TCHECK(dp->icmp_ip.ip_dst);
 425                 switch (dp->icmp_code) {
 426
 427                 case ICMP_TIMXCEED_INTRANS:
 428                         str = "time exceeded in-transit";
 429                         break;
 430
 431                 case ICMP_TIMXCEED_REASS:
 432                         str = "ip reassembly time exceeded";
 433                         break;
 434
 435                 default:
 436                         (void)snprintf(buf, sizeof(buf), "time exceeded-#%d",
 437                             dp->icmp_code);
 438                         break;
 439                 }
 440                 break;
 441
 442         case ICMP_PARAMPROB:
 443                 if (dp->icmp_code)
 444                         (void)snprintf(buf, sizeof(buf),
 445                             "parameter problem - code %d", dp->icmp_code);
 446                 else {
 447                         TCHECK(dp->icmp_pptr);
 448                         (void)snprintf(buf, sizeof(buf),
 449                             "parameter problem - octet %d", dp->icmp_pptr);
 450                 }
 451                 break;
 452
 453         case ICMP_MASKREPLY:
 454                 TCHECK(dp->icmp_mask);
 455                 (void)snprintf(buf, sizeof(buf), "address mask is 0x%08x",
 456                     (unsigned)ntohl(dp->icmp_mask));
 457                 break;
 458
 459         case ICMP_TSTAMP:
 460                 TCHECK(dp->icmp_seq);
 461                 (void)sprintf(buf, "time stamp query id %u seq %u",
 462                     (unsigned)ntohs(dp->icmp_id),
 463                     (unsigned)ntohs(dp->icmp_seq));
 464                 break;
 465
 466         case ICMP_TSTAMPREPLY:
 467                 TCHECK(dp->icmp_ttime);
 468                 (void)sprintf(buf, "time stamp reply id %u seq %u : org 0x%lx recv 0x%lx xmit 0x%lx",
 469                     (unsigned)ntohs(dp->icmp_id),
 470                     (unsigned)ntohs(dp->icmp_seq),
 471                     (unsigned long)ntohl(dp->icmp_otime),
 472                     (unsigned long)ntohl(dp->icmp_rtime),
 473                     (unsigned long)ntohl(dp->icmp_ttime));
 474                 break;
 475
 476         default:
 477                 str = tok2str(icmp2str, "type-#%d", dp->icmp_type);
 478                 break;
 479         }
 480         (void)printf("icmp: %s", str);
 481         if (vflag) {
 482                 if (TTEST2(*bp, plen)) {
 483                         if (in_cksum((u_short*)dp, plen, 0))
 484                                 printf(" (wrong icmp csum)");
 485                 }
 486         }
 487         if (vflag > 1 && !ICMP_INFOTYPE(dp->icmp_type)) {
 488                 bp += 8;
 489                 (void)printf(" for ");
 490                 ip = (struct ip *)bp;
 491                 snaplen = snapend - bp;
 492                 ip_print(bp, ntohs(ip->ip_len));
 493         }
 494         return;
 495 trunc:
 496         fputs("[|icmp]", stdout);
 497 }