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 1.51 2000-09-23 08:54:29 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 struct mbuf;
  36 struct rtentry;
  37 #include <net/if.h>
  38
  39 #include <netinet/in.h>
  40 #include <netinet/in_systm.h>
  41
  42 #include <stdio.h>
  43 #include <string.h>
  44
  45 #include "interface.h"
  46 #include "addrtoname.h"
  47 #include "extract.h"                    /* must come after interface.h */
  48
  49 #include "ip.h"
  50 #include "udp.h"
  51
  52 /*
  53  * Interface Control Message Protocol Definitions.
  54  * Per RFC 792, September 1981.
  55  */
  56
  57 /*
  58  * Structure of an icmp header.
  59  */
  60 struct icmp {
  61         u_char  icmp_type;              /* type of message, see below */
  62         u_char  icmp_code;              /* type sub code */
  63         u_short icmp_cksum;             /* ones complement cksum of struct */
  64         union {
  65                 u_char ih_pptr;                 /* ICMP_PARAMPROB */
  66                 struct in_addr ih_gwaddr;       /* ICMP_REDIRECT */
  67                 struct ih_idseq {
  68                         n_short icd_id;
  69                         n_short icd_seq;
  70                 } ih_idseq;
  71                 int ih_void;
  72
  73                 /* ICMP_UNREACH_NEEDFRAG -- Path MTU Discovery (RFC1191) */
  74                 struct ih_pmtu {
  75                         n_short ipm_void;
  76                         n_short ipm_nextmtu;
  77                 } ih_pmtu;
  78         } icmp_hun;
  79 #define icmp_pptr       icmp_hun.ih_pptr
  80 #define icmp_gwaddr     icmp_hun.ih_gwaddr
  81 #define icmp_id         icmp_hun.ih_idseq.icd_id
  82 #define icmp_seq        icmp_hun.ih_idseq.icd_seq
  83 #define icmp_void       icmp_hun.ih_void
  84 #define icmp_pmvoid     icmp_hun.ih_pmtu.ipm_void
  85 #define icmp_nextmtu    icmp_hun.ih_pmtu.ipm_nextmtu
  86         union {
  87                 struct id_ts {
  88                         n_time its_otime;
  89                         n_time its_rtime;
  90                         n_time its_ttime;
  91                 } id_ts;
  92                 struct id_ip  {
  93                         struct ip idi_ip;
  94                         /* options and then 64 bits of data */
  95                 } id_ip;
  96                 u_int   id_mask;
  97                 char    id_data[1];
  98         } icmp_dun;
  99 #define icmp_otime      icmp_dun.id_ts.its_otime
 100 #define icmp_rtime      icmp_dun.id_ts.its_rtime
 101 #define icmp_ttime      icmp_dun.id_ts.its_ttime
 102 #define icmp_ip         icmp_dun.id_ip.idi_ip
 103 #define icmp_mask       icmp_dun.id_mask
 104 #define icmp_data       icmp_dun.id_data
 105 };
 106
 107 /*
 108  * Lower bounds on packet lengths for various types.
 109  * For the error advice packets must first insure that the
 110  * packet is large enought to contain the returned ip header.
 111  * Only then can we do the check to see if 64 bits of packet
 112  * data have been returned, since we need to check the returned
 113  * ip header length.
 114  */
 115 #define ICMP_MINLEN     8                               /* abs minimum */
 116 #define ICMP_TSLEN      (8 + 3 * sizeof (n_time))       /* timestamp */
 117 #define ICMP_MASKLEN    12                              /* address mask */
 118 #define ICMP_ADVLENMIN  (8 + sizeof (struct ip) + 8)    /* min */
 119 #define ICMP_ADVLEN(p)  (8 + ((p)->icmp_ip.ip_hl << 2) + 8)
 120         /* N.B.: must separately check that ip_hl >= 5 */
 121
 122 /*
 123  * Definition of type and code field values.
 124  */
 125 #define ICMP_ECHOREPLY          0               /* echo reply */
 126 #define ICMP_UNREACH            3               /* dest unreachable, codes: */
 127 #define         ICMP_UNREACH_NET        0               /* bad net */
 128 #define         ICMP_UNREACH_HOST       1               /* bad host */
 129 #define         ICMP_UNREACH_PROTOCOL   2               /* bad protocol */
 130 #define         ICMP_UNREACH_PORT       3               /* bad port */
 131 #define         ICMP_UNREACH_NEEDFRAG   4               /* IP_DF caused drop */
 132 #define         ICMP_UNREACH_SRCFAIL    5               /* src route failed */
 133 #define         ICMP_UNREACH_NET_UNKNOWN 6              /* unknown net */
 134 #define         ICMP_UNREACH_HOST_UNKNOWN 7             /* unknown host */
 135 #define         ICMP_UNREACH_ISOLATED   8               /* src host isolated */
 136 #define         ICMP_UNREACH_NET_PROHIB 9               /* prohibited access */
 137 #define         ICMP_UNREACH_HOST_PROHIB 10             /* ditto */
 138 #define         ICMP_UNREACH_TOSNET     11              /* bad tos for net */
 139 #define         ICMP_UNREACH_TOSHOST    12              /* bad tos for host */
 140 #define ICMP_SOURCEQUENCH       4               /* packet lost, slow down */
 141 #define ICMP_REDIRECT           5               /* shorter route, codes: */
 142 #define         ICMP_REDIRECT_NET       0               /* for network */
 143 #define         ICMP_REDIRECT_HOST      1               /* for host */
 144 #define         ICMP_REDIRECT_TOSNET    2               /* for tos and net */
 145 #define         ICMP_REDIRECT_TOSHOST   3               /* for tos and host */
 146 #define ICMP_ECHO               8               /* echo service */
 147 #define ICMP_ROUTERADVERT       9               /* router advertisement */
 148 #define ICMP_ROUTERSOLICIT      10              /* router solicitation */
 149 #define ICMP_TIMXCEED           11              /* time exceeded, code: */
 150 #define         ICMP_TIMXCEED_INTRANS   0               /* ttl==0 in transit */
 151 #define         ICMP_TIMXCEED_REASS     1               /* ttl==0 in reass */
 152 #define ICMP_PARAMPROB          12              /* ip header bad */
 153 #define         ICMP_PARAMPROB_OPTABSENT 1              /* req. opt. absent */
 154 #define ICMP_TSTAMP             13              /* timestamp request */
 155 #define ICMP_TSTAMPREPLY        14              /* timestamp reply */
 156 #define ICMP_IREQ               15              /* information request */
 157 #define ICMP_IREQREPLY          16              /* information reply */
 158 #define ICMP_MASKREQ            17              /* address mask request */
 159 #define ICMP_MASKREPLY          18              /* address mask reply */
 160
 161 #define ICMP_MAXTYPE            18
 162
 163 #define ICMP_INFOTYPE(type) \
 164         ((type) == ICMP_ECHOREPLY || (type) == ICMP_ECHO || \
 165         (type) == ICMP_ROUTERADVERT || (type) == ICMP_ROUTERSOLICIT || \
 166         (type) == ICMP_TSTAMP || (type) == ICMP_TSTAMPREPLY || \
 167         (type) == ICMP_IREQ || (type) == ICMP_IREQREPLY || \
 168         (type) == ICMP_MASKREQ || (type) == ICMP_MASKREPLY)
 169 /* rfc1700 */
 170 #ifndef ICMP_UNREACH_NET_UNKNOWN
 171 #define ICMP_UNREACH_NET_UNKNOWN        6       /* destination net unknown */
 172 #endif
 173 #ifndef ICMP_UNREACH_HOST_UNKNOWN
 174 #define ICMP_UNREACH_HOST_UNKNOWN       7       /* destination host unknown */
 175 #endif
 176 #ifndef ICMP_UNREACH_ISOLATED
 177 #define ICMP_UNREACH_ISOLATED           8       /* source host isolated */
 178 #endif
 179 #ifndef ICMP_UNREACH_NET_PROHIB
 180 #define ICMP_UNREACH_NET_PROHIB         9       /* admin prohibited net */
 181 #endif
 182 #ifndef ICMP_UNREACH_HOST_PROHIB
 183 #define ICMP_UNREACH_HOST_PROHIB        10      /* admin prohibited host */
 184 #endif
 185 #ifndef ICMP_UNREACH_TOSNET
 186 #define ICMP_UNREACH_TOSNET             11      /* tos prohibited net */
 187 #endif
 188 #ifndef ICMP_UNREACH_TOSHOST
 189 #define ICMP_UNREACH_TOSHOST            12      /* tos prohibited host */
 190 #endif
 191
 192 /* rfc1716 */
 193 #ifndef ICMP_UNREACH_FILTER_PROHIB
 194 #define ICMP_UNREACH_FILTER_PROHIB      13      /* admin prohibited filter */
 195 #endif
 196 #ifndef ICMP_UNREACH_HOST_PRECEDENCE
 197 #define ICMP_UNREACH_HOST_PRECEDENCE    14      /* host precedence violation */
 198 #endif
 199 #ifndef ICMP_UNREACH_PRECEDENCE_CUTOFF
 200 #define ICMP_UNREACH_PRECEDENCE_CUTOFF  15      /* precedence cutoff */
 201 #endif
 202
 203 /* Most of the icmp types */
 204 static struct tok icmp2str[] = {
 205         { ICMP_ECHOREPLY,               "echo reply" },
 206         { ICMP_SOURCEQUENCH,            "source quench" },
 207         { ICMP_ECHO,                    "echo request" },
 208         { ICMP_ROUTERSOLICIT,           "router solicitation" },
 209         { ICMP_TSTAMP,                  "time stamp request" },
 210         { ICMP_TSTAMPREPLY,             "time stamp reply" },
 211         { ICMP_IREQ,                    "information request" },
 212         { ICMP_IREQREPLY,               "information reply" },
 213         { ICMP_MASKREQ,                 "address mask request" },
 214         { 0,                            NULL }
 215 };
 216
 217 /* Formats for most of the ICMP_UNREACH codes */
 218 static struct tok unreach2str[] = {
 219         { ICMP_UNREACH_NET,             "net %s unreachable" },
 220         { ICMP_UNREACH_HOST,            "host %s unreachable" },
 221         { ICMP_UNREACH_SRCFAIL,
 222             "%s unreachable - source route failed" },
 223         { ICMP_UNREACH_NET_UNKNOWN,     "net %s unreachable - unknown" },
 224         { ICMP_UNREACH_HOST_UNKNOWN,    "host %s unreachable - unknown" },
 225         { ICMP_UNREACH_ISOLATED,
 226             "%s unreachable - source host isolated" },
 227         { ICMP_UNREACH_NET_PROHIB,
 228             "net %s unreachable - admin prohibited" },
 229         { ICMP_UNREACH_HOST_PROHIB,
 230             "host %s unreachable - admin prohibited" },
 231         { ICMP_UNREACH_TOSNET,
 232             "net %s unreachable - tos prohibited" },
 233         { ICMP_UNREACH_TOSHOST,
 234             "host %s unreachable - tos prohibited" },
 235         { ICMP_UNREACH_FILTER_PROHIB,
 236             "host %s unreachable - admin prohibited filter" },
 237         { ICMP_UNREACH_HOST_PRECEDENCE,
 238             "host %s unreachable - host precedence violation" },
 239         { ICMP_UNREACH_PRECEDENCE_CUTOFF,
 240             "host %s unreachable - precedence cutoff" },
 241         { 0,                            NULL }
 242 };
 243
 244 /* Formats for the ICMP_REDIRECT codes */
 245 static struct tok type2str[] = {
 246         { ICMP_REDIRECT_NET,            "redirect %s to net %s" },
 247         { ICMP_REDIRECT_HOST,           "redirect %s to host %s" },
 248         { ICMP_REDIRECT_TOSNET,         "redirect-tos %s to net %s" },
 249         { ICMP_REDIRECT_TOSHOST,        "redirect-tos %s to net %s" },
 250         { 0,                            NULL }
 251 };
 252
 253 /* rfc1191 */
 254 struct mtu_discovery {
 255         short unused;
 256         short nexthopmtu;
 257 };
 258
 259 /* rfc1256 */
 260 struct ih_rdiscovery {
 261         u_char ird_addrnum;
 262         u_char ird_addrsiz;
 263         u_short ird_lifetime;
 264 };
 265
 266 struct id_rdiscovery {
 267         u_int32_t ird_addr;
 268         u_int32_t ird_pref;
 269 };
 270
 271 void
 272 icmp_print(register const u_char *bp, u_int plen, register const u_char *bp2)
 273 {
 274         register char *cp;
 275         register const struct icmp *dp;
 276         register const struct ip *ip;
 277         register const char *str, *fmt;
 278         register const struct ip *oip;
 279         register const struct udphdr *ouh;
 280         register u_int hlen, dport, mtu;
 281         char buf[256];
 282
 283         dp = (struct icmp *)bp;
 284         ip = (struct ip *)bp2;
 285         str = buf;
 286
 287 #if 0
 288         (void)printf("%s > %s: ",
 289                 ipaddr_string(&ip->ip_src),
 290                 ipaddr_string(&ip->ip_dst));
 291 #endif
 292
 293         TCHECK(dp->icmp_code);
 294         switch (dp->icmp_type) {
 295
 296         case ICMP_UNREACH:
 297                 TCHECK(dp->icmp_ip.ip_dst);
 298                 switch (dp->icmp_code) {
 299
 300                 case ICMP_UNREACH_PROTOCOL:
 301                         TCHECK(dp->icmp_ip.ip_p);
 302                         (void)snprintf(buf, sizeof(buf),
 303                             "%s protocol %d unreachable",
 304                             ipaddr_string(&dp->icmp_ip.ip_dst),
 305                             dp->icmp_ip.ip_p);
 306                         break;
 307
 308                 case ICMP_UNREACH_PORT:
 309                         TCHECK(dp->icmp_ip.ip_p);
 310                         oip = &dp->icmp_ip;
 311                         hlen = oip->ip_hl * 4;
 312                         ouh = (struct udphdr *)(((u_char *)oip) + hlen);
 313                         dport = ntohs(ouh->uh_dport);
 314                         switch (oip->ip_p) {
 315
 316                         case IPPROTO_TCP:
 317                                 (void)snprintf(buf, sizeof(buf),
 318                                         "%s tcp port %s unreachable",
 319                                         ipaddr_string(&oip->ip_dst),
 320                                         tcpport_string(dport));
 321                                 break;
 322
 323                         case IPPROTO_UDP:
 324                                 (void)snprintf(buf, sizeof(buf),
 325                                         "%s udp port %s unreachable",
 326                                         ipaddr_string(&oip->ip_dst),
 327                                         udpport_string(dport));
 328                                 break;
 329
 330                         default:
 331                                 (void)snprintf(buf, sizeof(buf),
 332                                         "%s protocol %d port %d unreachable",
 333                                         ipaddr_string(&oip->ip_dst),
 334                                         oip->ip_p, dport);
 335                                 break;
 336                         }
 337                         break;
 338
 339                 case ICMP_UNREACH_NEEDFRAG:
 340                     {
 341                         register const struct mtu_discovery *mp;
 342                         mp = (struct mtu_discovery *)&dp->icmp_void;
 343                         mtu = EXTRACT_16BITS(&mp->nexthopmtu);
 344                         if (mtu) {
 345                                 (void)snprintf(buf, sizeof(buf),
 346                                     "%s unreachable - need to frag (mtu %d)",
 347                                     ipaddr_string(&dp->icmp_ip.ip_dst), mtu);
 348                         } else {
 349                                 (void)snprintf(buf, sizeof(buf),
 350                                     "%s unreachable - need to frag",
 351                                     ipaddr_string(&dp->icmp_ip.ip_dst));
 352                         }
 353                     }
 354                         break;
 355
 356                 default:
 357                         fmt = tok2str(unreach2str, "#%d %%s unreachable",
 358                             dp->icmp_code);
 359                         (void)snprintf(buf, sizeof(buf), fmt,
 360                             ipaddr_string(&dp->icmp_ip.ip_dst));
 361                         break;
 362                 }
 363                 break;
 364
 365         case ICMP_REDIRECT:
 366                 TCHECK(dp->icmp_ip.ip_dst);
 367                 fmt = tok2str(type2str, "redirect-#%d %%s to net %%s",
 368                     dp->icmp_code);
 369                 (void)snprintf(buf, sizeof(buf), fmt,
 370                     ipaddr_string(&dp->icmp_ip.ip_dst),
 371                     ipaddr_string(&dp->icmp_gwaddr));
 372                 break;
 373
 374         case ICMP_ROUTERADVERT:
 375             {
 376                 register const struct ih_rdiscovery *ihp;
 377                 register const struct id_rdiscovery *idp;
 378                 u_int lifetime, num, size;
 379
 380                 (void)snprintf(buf, sizeof(buf), "router advertisement");
 381                 cp = buf + strlen(buf);
 382
 383                 ihp = (struct ih_rdiscovery *)&dp->icmp_void;
 384                 TCHECK(*ihp);
 385                 (void)strncpy(cp, " lifetime ", sizeof(buf) - (cp - buf));
 386                 cp = buf + strlen(buf);
 387                 lifetime = EXTRACT_16BITS(&ihp->ird_lifetime);
 388                 if (lifetime < 60) {
 389                         (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u",
 390                             lifetime);
 391                 } else if (lifetime < 60 * 60) {
 392                         (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u:%02u",
 393                             lifetime / 60, lifetime % 60);
 394                 } else {
 395                         (void)snprintf(cp, sizeof(buf) - (cp - buf),
 396                             "%u:%02u:%02u",
 397                             lifetime / 3600,
 398                             (lifetime % 3600) / 60,
 399                             lifetime % 60);
 400                 }
 401                 cp = buf + strlen(buf);
 402
 403                 num = ihp->ird_addrnum;
 404                 (void)snprintf(cp, sizeof(buf) - (cp - buf), " %d:", num);
 405                 cp = buf + strlen(buf);
 406
 407                 size = ihp->ird_addrsiz;
 408                 if (size != 2) {
 409                         (void)snprintf(cp, sizeof(buf) - (cp - buf),
 410                             " [size %d]", size);
 411                         break;
 412                 }
 413                 idp = (struct id_rdiscovery *)&dp->icmp_data;
 414                 while (num-- > 0) {
 415                         TCHECK(*idp);
 416                         (void)snprintf(cp, sizeof(buf) - (cp - buf), " {%s %u}",
 417                             ipaddr_string(&idp->ird_addr),
 418                             EXTRACT_32BITS(&idp->ird_pref));
 419                         cp = buf + strlen(buf);
 420                         ++idp;
 421                 }
 422             }
 423                 break;
 424
 425         case ICMP_TIMXCEED:
 426                 TCHECK(dp->icmp_ip.ip_dst);
 427                 switch (dp->icmp_code) {
 428
 429                 case ICMP_TIMXCEED_INTRANS:
 430                         str = "time exceeded in-transit";
 431                         break;
 432
 433                 case ICMP_TIMXCEED_REASS:
 434                         str = "ip reassembly time exceeded";
 435                         break;
 436
 437                 default:
 438                         (void)snprintf(buf, sizeof(buf), "time exceeded-#%d",
 439                             dp->icmp_code);
 440                         break;
 441                 }
 442                 break;
 443
 444         case ICMP_PARAMPROB:
 445                 if (dp->icmp_code)
 446                         (void)snprintf(buf, sizeof(buf),
 447                             "parameter problem - code %d", dp->icmp_code);
 448                 else {
 449                         TCHECK(dp->icmp_pptr);
 450                         (void)snprintf(buf, sizeof(buf),
 451                             "parameter problem - octet %d", dp->icmp_pptr);
 452                 }
 453                 break;
 454
 455         case ICMP_MASKREPLY:
 456                 TCHECK(dp->icmp_mask);
 457                 (void)snprintf(buf, sizeof(buf), "address mask is 0x%08x",
 458                     (unsigned)ntohl(dp->icmp_mask));
 459                 break;
 460
 461         case ICMP_TSTAMP:
 462                 TCHECK(dp->icmp_seq);
 463                 (void)sprintf(buf, "time stamp query id %u seq %u",
 464                     (unsigned)ntohs(dp->icmp_id),
 465                     (unsigned)ntohs(dp->icmp_seq));
 466                 break;
 467
 468         case ICMP_TSTAMPREPLY:
 469                 TCHECK(dp->icmp_ttime);
 470                 (void)sprintf(buf, "time stamp reply id %u seq %u : org 0x%lx recv 0x%lx xmit 0x%lx",
 471                     (unsigned)ntohs(dp->icmp_id),
 472                     (unsigned)ntohs(dp->icmp_seq),
 473                     (unsigned long)ntohl(dp->icmp_otime),
 474                     (unsigned long)ntohl(dp->icmp_rtime),
 475                     (unsigned long)ntohl(dp->icmp_ttime));
 476                 break;
 477
 478         default:
 479                 str = tok2str(icmp2str, "type-#%d", dp->icmp_type);
 480                 break;
 481         }
 482         (void)printf("icmp: %s", str);
 483         if (vflag) {
 484                 if (TTEST2(*bp, plen)) {
 485                         if (in_cksum((u_short*)dp, plen, 0))
 486                                 printf(" (wrong icmp csum)");
 487                 }
 488         }
 489         if (vflag > 1 && !ICMP_INFOTYPE(dp->icmp_type)) {
 490                 bp += 8;
 491                 (void)printf(" for ");
 492                 ip = (struct ip *)bp;
 493                 snaplen = snapend - bp;
 494                 ip_print(bp, ntohs(ip->ip_len));
 495         }
 496         return;
 497 trunc:
 498         fputs("[|icmp]", stdout);
 499 }