contrib/tcpdump-3.9/print-ip.c

   1 /*
   2  * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997
   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[] _U_ =
  24     "@(#) $Header: /tcpdump/master/tcpdump/print-ip.c,v 1.149.2.6 2006/02/19 05:01:07 guy Exp $ (LBL)";
  25 #endif
  26
  27 #ifdef HAVE_CONFIG_H
  28 #include "config.h"
  29 #endif
  30
  31 #include <tcpdump-stdinc.h>
  32
  33 #include <stdio.h>
  34 #include <stdlib.h>
  35 #include <string.h>
  36
  37 #include "addrtoname.h"
  38 #include "interface.h"
  39 #include "extract.h"                    /* must come after interface.h */
  40
  41 #include "ip.h"
  42 #include "ipproto.h"
  43
  44 struct tok ip_option_values[] = {
  45     { IPOPT_EOL, "EOL" },
  46     { IPOPT_NOP, "NOP" },
  47     { IPOPT_TS, "timestamp" },
  48     { IPOPT_SECURITY, "security" },
  49     { IPOPT_RR, "RR" },
  50     { IPOPT_SSRR, "SSRR" },
  51     { IPOPT_LSRR, "LSRR" },
  52     { IPOPT_RA, "RA" },
  53     { 0, NULL }
  54 };
  55
  56 /*
  57  * print the recorded route in an IP RR, LSRR or SSRR option.
  58  */
  59 static void
  60 ip_printroute(register const u_char *cp, u_int length)
  61 {
  62         register u_int ptr;
  63         register u_int len;
  64
  65         if (length < 3) {
  66                 printf(" [bad length %u]", length);
  67                 return;
  68         }
  69         if ((length + 1) & 3)
  70                 printf(" [bad length %u]", length);
  71         ptr = cp[2] - 1;
  72         if (ptr < 3 || ((ptr + 1) & 3) || ptr > length + 1)
  73                 printf(" [bad ptr %u]", cp[2]);
  74
  75         for (len = 3; len < length; len += 4) {
  76                 printf(" %s", ipaddr_string(&cp[len]));
  77                 if (ptr > len)
  78                         printf(",");
  79         }
  80 }
  81
  82 /*
  83  * If source-routing is present and valid, return the final destination.
  84  * Otherwise, return IP destination.
  85  *
  86  * This is used for UDP and TCP pseudo-header in the checksum
  87  * calculation.
  88  */
  89 u_int32_t
  90 ip_finddst(const struct ip *ip)
  91 {
  92         int length;
  93         int len;
  94         const u_char *cp;
  95         u_int32_t retval;
  96
  97         cp = (const u_char *)(ip + 1);
  98         length = (IP_HL(ip) << 2) - sizeof(struct ip);
  99
 100         for (; length > 0; cp += len, length -= len) {
 101                 int tt;
 102
 103                 TCHECK(*cp);
 104                 tt = *cp;
 105                 if (tt == IPOPT_EOL)
 106                         break;
 107                 else if (tt == IPOPT_NOP)
 108                         len = 1;
 109                 else {
 110                         TCHECK(cp[1]);
 111                         len = cp[1];
 112                         if (len < 2)
 113                                 break;
 114                 }
 115                 TCHECK2(*cp, len);
 116                 switch (tt) {
 117
 118                 case IPOPT_SSRR:
 119                 case IPOPT_LSRR:
 120                         if (len < 7)
 121                                 break;
 122                         memcpy(&retval, cp + len - 4, 4);
 123                         return retval;
 124                 }
 125         }
 126 trunc:
 127         memcpy(&retval, &ip->ip_dst.s_addr, sizeof(u_int32_t));
 128         return retval;
 129 }
 130
 131 static void
 132 ip_printts(register const u_char *cp, u_int length)
 133 {
 134         register u_int ptr;
 135         register u_int len;
 136         int hoplen;
 137         const char *type;
 138
 139         if (length < 4) {
 140                 printf("[bad length %u]", length);
 141                 return;
 142         }
 143         printf(" TS{");
 144         hoplen = ((cp[3]&0xF) != IPOPT_TS_TSONLY) ? 8 : 4;
 145         if ((length - 4) & (hoplen-1))
 146                 printf("[bad length %u]", length);
 147         ptr = cp[2] - 1;
 148         len = 0;
 149         if (ptr < 4 || ((ptr - 4) & (hoplen-1)) || ptr > length + 1)
 150                 printf("[bad ptr %u]", cp[2]);
 151         switch (cp[3]&0xF) {
 152         case IPOPT_TS_TSONLY:
 153                 printf("TSONLY");
 154                 break;
 155         case IPOPT_TS_TSANDADDR:
 156                 printf("TS+ADDR");
 157                 break;
 158         /*
 159          * prespecified should really be 3, but some ones might send 2
 160          * instead, and the IPOPT_TS_PRESPEC constant can apparently
 161          * have both values, so we have to hard-code it here.
 162          */
 163
 164         case 2:
 165                 printf("PRESPEC2.0");
 166                 break;
 167         case 3:                 /* IPOPT_TS_PRESPEC */
 168                 printf("PRESPEC");
 169                 break;
 170         default:
 171                 printf("[bad ts type %d]", cp[3]&0xF);
 172                 goto done;
 173         }
 174
 175         type = " ";
 176         for (len = 4; len < length; len += hoplen) {
 177                 if (ptr == len)
 178                         type = " ^ ";
 179                 printf("%s%d@%s", type, EXTRACT_32BITS(&cp[len+hoplen-4]),
 180                        hoplen!=8 ? "" : ipaddr_string(&cp[len]));
 181                 type = " ";
 182         }
 183
 184 done:
 185         printf("%s", ptr == len ? " ^ " : "");
 186
 187         if (cp[3]>>4)
 188                 printf(" [%d hops not recorded]} ", cp[3]>>4);
 189         else
 190                 printf("}");
 191 }
 192
 193 /*
 194  * print IP options.
 195  */
 196 static void
 197 ip_optprint(register const u_char *cp, u_int length)
 198 {
 199         register u_int option_len;
 200         const char *sep = "";
 201
 202         for (; length > 0; cp += option_len, length -= option_len) {
 203                 u_int option_code;
 204
 205                 printf("%s", sep);
 206                 sep = ",";
 207
 208                 TCHECK(*cp);
 209                 option_code = *cp;
 210
 211                 printf("%s",
 212                         tok2str(ip_option_values,"unknown %u",option_code));
 213
 214                 if (option_code == IPOPT_NOP ||
 215                     option_code == IPOPT_EOL)
 216                         option_len = 1;
 217
 218                 else {
 219                         TCHECK(cp[1]);
 220                         option_len = cp[1];
 221                         if (option_len < 2) {
 222                                 printf(" [bad length %u]", option_len);
 223                                 return;
 224                         }
 225                 }
 226
 227                 if (option_len > length) {
 228                         printf(" [bad length %u]", option_len);
 229                         return;
 230                 }
 231
 232                 TCHECK2(*cp, option_len);
 233
 234                 switch (option_code) {
 235                 case IPOPT_EOL:
 236                         return;
 237
 238                 case IPOPT_TS:
 239                         ip_printts(cp, option_len);
 240                         break;
 241
 242                 case IPOPT_RR:       /* fall through */
 243                 case IPOPT_SSRR:
 244                 case IPOPT_LSRR:
 245                         ip_printroute(cp, option_len);
 246                         break;
 247
 248                 case IPOPT_RA:
 249                         if (option_len < 4) {
 250                                 printf(" [bad length %u]", option_len);
 251                                 break;
 252                         }
 253                         TCHECK(cp[3]);
 254                         if (EXTRACT_16BITS(&cp[2]) != 0)
 255                             printf(" value %u", EXTRACT_16BITS(&cp[2]));
 256                         break;
 257
 258                 case IPOPT_NOP:       /* nothing to print - fall through */
 259                 case IPOPT_SECURITY:
 260                 default:
 261                         break;
 262                 }
 263         }
 264         return;
 265
 266 trunc:
 267         printf("[|ip]");
 268 }
 269
 270 /*
 271  * compute an IP header checksum.
 272  * don't modifiy the packet.
 273  */
 274 u_short
 275 in_cksum(const u_short *addr, register u_int len, int csum)
 276 {
 277         int nleft = len;
 278         const u_short *w = addr;
 279         u_short answer;
 280         int sum = csum;
 281
 282         /*
 283          *  Our algorithm is simple, using a 32 bit accumulator (sum),
 284          *  we add sequential 16 bit words to it, and at the end, fold
 285          *  back all the carry bits from the top 16 bits into the lower
 286          *  16 bits.
 287          */
 288         while (nleft > 1)  {
 289                 sum += *w++;
 290                 nleft -= 2;
 291         }
 292         if (nleft == 1)
 293                 sum += htons(*(u_char *)w<<8);
 294
 295         /*
 296          * add back carry outs from top 16 bits to low 16 bits
 297          */
 298         sum = (sum >> 16) + (sum & 0xffff);     /* add hi 16 to low 16 */
 299         sum += (sum >> 16);                     /* add carry */
 300         answer = ~sum;                          /* truncate to 16 bits */
 301         return (answer);
 302 }
 303
 304 /*
 305  * Given the host-byte-order value of the checksum field in a packet
 306  * header, and the network-byte-order computed checksum of the data
 307  * that the checksum covers (including the checksum itself), compute
 308  * what the checksum field *should* have been.
 309  */
 310 u_int16_t
 311 in_cksum_shouldbe(u_int16_t sum, u_int16_t computed_sum)
 312 {
 313         u_int32_t shouldbe;
 314
 315         /*
 316          * The value that should have gone into the checksum field
 317          * is the negative of the value gotten by summing up everything
 318          * *but* the checksum field.
 319          *
 320          * We can compute that by subtracting the value of the checksum
 321          * field from the sum of all the data in the packet, and then
 322          * computing the negative of that value.
 323          *
 324          * "sum" is the value of the checksum field, and "computed_sum"
 325          * is the negative of the sum of all the data in the packets,
 326          * so that's -(-computed_sum - sum), or (sum + computed_sum).
 327          *
 328          * All the arithmetic in question is one's complement, so the
 329          * addition must include an end-around carry; we do this by
 330          * doing the arithmetic in 32 bits (with no sign-extension),
 331          * and then adding the upper 16 bits of the sum, which contain
 332          * the carry, to the lower 16 bits of the sum, and then do it
 333          * again in case *that* sum produced a carry.
 334          *
 335          * As RFC 1071 notes, the checksum can be computed without
 336          * byte-swapping the 16-bit words; summing 16-bit words
 337          * on a big-endian machine gives a big-endian checksum, which
 338          * can be directly stuffed into the big-endian checksum fields
 339          * in protocol headers, and summing words on a little-endian
 340          * machine gives a little-endian checksum, which must be
 341          * byte-swapped before being stuffed into a big-endian checksum
 342          * field.
 343          *
 344          * "computed_sum" is a network-byte-order value, so we must put
 345          * it in host byte order before subtracting it from the
 346          * host-byte-order value from the header; the adjusted checksum
 347          * will be in host byte order, which is what we'll return.
 348          */
 349         shouldbe = sum;
 350         shouldbe += ntohs(computed_sum);
 351         shouldbe = (shouldbe & 0xFFFF) + (shouldbe >> 16);
 352         shouldbe = (shouldbe & 0xFFFF) + (shouldbe >> 16);
 353         return shouldbe;
 354 }
 355
 356 #define IP_RES 0x8000
 357
 358 static struct tok ip_frag_values[] = {
 359         { IP_MF,        "+" },
 360         { IP_DF,        "DF" },
 361         { IP_RES,       "rsvd" }, /* The RFC3514 evil ;-) bit */
 362         { 0,            NULL }
 363 };
 364
 365 struct ip_print_demux_state {
 366         const struct ip *ip;
 367         const u_char *cp;
 368         u_int   len, off;
 369         u_char  nh;
 370         int     advance;
 371 };
 372
 373 static void
 374 ip_print_demux(netdissect_options *ndo,
 375                struct ip_print_demux_state *ipds)
 376 {
 377         struct protoent *proto;
 378
 379 again:
 380         switch (ipds->nh) {
 381
 382         case IPPROTO_AH:
 383                 ipds->nh = *ipds->cp;
 384                 ipds->advance = ah_print(ipds->cp);
 385                 if (ipds->advance <= 0)
 386                         break;
 387                 ipds->cp += ipds->advance;
 388                 ipds->len -= ipds->advance;
 389                 goto again;
 390
 391         case IPPROTO_ESP:
 392         {
 393                 int enh, padlen;
 394                 ipds->advance = esp_print(ndo, ipds->cp, ipds->len,
 395                                     (const u_char *)ipds->ip,
 396                                     &enh, &padlen);
 397                 if (ipds->advance <= 0)
 398                         break;
 399                 ipds->cp += ipds->advance;
 400                 ipds->len -= ipds->advance + padlen;
 401                 ipds->nh = enh & 0xff;
 402                 goto again;
 403         }
 404
 405         case IPPROTO_IPCOMP:
 406         {
 407                 int enh;
 408                 ipds->advance = ipcomp_print(ipds->cp, &enh);
 409                 if (ipds->advance <= 0)
 410                         break;
 411                 ipds->cp += ipds->advance;
 412                 ipds->len -= ipds->advance;
 413                 ipds->nh = enh & 0xff;
 414                 goto again;
 415         }
 416
 417         case IPPROTO_SCTP:
 418                 sctp_print(ipds->cp, (const u_char *)ipds->ip, ipds->len);
 419                 break;
 420
 421         case IPPROTO_DCCP:
 422                 dccp_print(ipds->cp, (const u_char *)ipds->ip, ipds->len);
 423                 break;
 424
 425         case IPPROTO_TCP:
 426                 /* pass on the MF bit plus the offset to detect fragments */
 427                 tcp_print(ipds->cp, ipds->len, (const u_char *)ipds->ip,
 428                           ipds->off & (IP_MF|IP_OFFMASK));
 429                 break;
 430
 431         case IPPROTO_UDP:
 432                 /* pass on the MF bit plus the offset to detect fragments */
 433                 udp_print(ipds->cp, ipds->len, (const u_char *)ipds->ip,
 434                           ipds->off & (IP_MF|IP_OFFMASK));
 435                 break;
 436
 437         case IPPROTO_ICMP:
 438                 /* pass on the MF bit plus the offset to detect fragments */
 439                 icmp_print(ipds->cp, ipds->len, (const u_char *)ipds->ip,
 440                            ipds->off & (IP_MF|IP_OFFMASK));
 441                 break;
 442
 443         case IPPROTO_PIGP:
 444                 /*
 445                  * XXX - the current IANA protocol number assignments
 446                  * page lists 9 as "any private interior gateway
 447                  * (used by Cisco for their IGRP)" and 88 as
 448                  * "EIGRP" from Cisco.
 449                  *
 450                  * Recent BSD <netinet/in.h> headers define
 451                  * IP_PROTO_PIGP as 9 and IP_PROTO_IGRP as 88.
 452                  * We define IP_PROTO_PIGP as 9 and
 453                  * IP_PROTO_EIGRP as 88; those names better
 454                  * match was the current protocol number
 455                  * assignments say.
 456                  */
 457                 igrp_print(ipds->cp, ipds->len, (const u_char *)ipds->ip);
 458                 break;
 459
 460         case IPPROTO_EIGRP:
 461                 eigrp_print(ipds->cp, ipds->len);
 462                 break;
 463
 464         case IPPROTO_ND:
 465                 ND_PRINT((ndo, " nd %d", ipds->len));
 466                 break;
 467
 468         case IPPROTO_EGP:
 469                 egp_print(ipds->cp, ipds->len);
 470                 break;
 471
 472         case IPPROTO_OSPF:
 473                 ospf_print(ipds->cp, ipds->len, (const u_char *)ipds->ip);
 474                 break;
 475
 476         case IPPROTO_IGMP:
 477                 igmp_print(ipds->cp, ipds->len);
 478                 break;
 479
 480         case IPPROTO_IPV4:
 481                 /* DVMRP multicast tunnel (ip-in-ip encapsulation) */
 482                 ip_print(gndo, ipds->cp, ipds->len);
 483                 if (! vflag) {
 484                         ND_PRINT((ndo, " (ipip-proto-4)"));
 485                         return;
 486                 }
 487                 break;
 488
 489 #ifdef INET6
 490         case IPPROTO_IPV6:
 491                 /* ip6-in-ip encapsulation */
 492                 ip6_print(ipds->cp, ipds->len);
 493                 break;
 494 #endif /*INET6*/
 495
 496         case IPPROTO_RSVP:
 497                 rsvp_print(ipds->cp, ipds->len);
 498                 break;
 499
 500         case IPPROTO_GRE:
 501                 /* do it */
 502                 gre_print(ipds->cp, ipds->len);
 503                 break;
 504
 505         case IPPROTO_MOBILE:
 506                 mobile_print(ipds->cp, ipds->len);
 507                 break;
 508
 509         case IPPROTO_PIM:
 510                 pim_print(ipds->cp,  ipds->len);
 511                 break;
 512
 513         case IPPROTO_VRRP:
 514                 vrrp_print(ipds->cp, ipds->len, ipds->ip->ip_ttl);
 515                 break;
 516
 517         case IPPROTO_PGM:
 518                 pgm_print(ipds->cp, ipds->len, (const u_char *)ipds->ip);
 519                 break;
 520
 521         default:
 522                 if ((proto = getprotobynumber(ipds->nh)) != NULL)
 523                         ND_PRINT((ndo, " %s", proto->p_name));
 524                 else
 525                         ND_PRINT((ndo, " ip-proto-%d", ipds->nh));
 526                 ND_PRINT((ndo, " %d", ipds->len));
 527                 break;
 528         }
 529 }
 530
 531 void
 532 ip_print_inner(netdissect_options *ndo,
 533                const u_char *bp,
 534                u_int length, u_int nh,
 535                const u_char *bp2)
 536 {
 537         struct ip_print_demux_state  ipd;
 538
 539         ipd.ip = (const struct ip *)bp2;
 540         ipd.cp = bp;
 541         ipd.len  = length;
 542         ipd.off  = 0;
 543         ipd.nh   = nh;
 544         ipd.advance = 0;
 545
 546         ip_print_demux(ndo, &ipd);
 547 }
 548
 549
 550 /*
 551  * print an IP datagram.
 552  */
 553 void
 554 ip_print(netdissect_options *ndo,
 555          const u_char *bp,
 556          u_int length)
 557 {
 558         struct ip_print_demux_state  ipd;
 559         struct ip_print_demux_state *ipds=&ipd;
 560         const u_char *ipend;
 561         u_int hlen;
 562         u_int16_t sum, ip_sum;
 563         struct protoent *proto;
 564
 565         ipds->ip = (const struct ip *)bp;
 566         if (IP_V(ipds->ip) != 4) { /* print version if != 4 */
 567             printf("IP%u ", IP_V(ipds->ip));
 568             if (IP_V(ipds->ip) == 6)
 569                 printf(", wrong link-layer encapsulation");
 570         }
 571         else if (!eflag)
 572             printf("IP ");
 573
 574         if ((u_char *)(ipds->ip + 1) > snapend) {
 575                 printf("[|ip]");
 576                 return;
 577         }
 578         if (length < sizeof (struct ip)) {
 579                 (void)printf("truncated-ip %u", length);
 580                 return;
 581         }
 582         hlen = IP_HL(ipds->ip) * 4;
 583         if (hlen < sizeof (struct ip)) {
 584                 (void)printf("bad-hlen %u", hlen);
 585                 return;
 586         }
 587
 588         ipds->len = EXTRACT_16BITS(&ipds->ip->ip_len);
 589         if (length < ipds->len)
 590                 (void)printf("truncated-ip - %u bytes missing! ",
 591                         ipds->len - length);
 592         if (ipds->len < hlen) {
 593 #ifdef GUESS_TSO
 594             if (ipds->len) {
 595                 (void)printf("bad-len %u", ipds->len);
 596                 return;
 597             }
 598             else {
 599                 /* we guess that it is a TSO send */
 600                 ipds->len = length;
 601             }
 602 #else
 603             (void)printf("bad-len %u", ipds->len);
 604             return;
 605 #endif /* GUESS_TSO */
 606         }
 607
 608         /*
 609          * Cut off the snapshot length to the end of the IP payload.
 610          */
 611         ipend = bp + ipds->len;
 612         if (ipend < snapend)
 613                 snapend = ipend;
 614
 615         ipds->len -= hlen;
 616
 617         ipds->off = EXTRACT_16BITS(&ipds->ip->ip_off);
 618
 619         if (vflag) {
 620             (void)printf("(tos 0x%x", (int)ipds->ip->ip_tos);
 621             /* ECN bits */
 622             if (ipds->ip->ip_tos & 0x03) {
 623                 switch (ipds->ip->ip_tos & 0x03) {
 624                 case 1:
 625                     (void)printf(",ECT(1)");
 626                     break;
 627                 case 2:
 628                     (void)printf(",ECT(0)");
 629                     break;
 630                 case 3:
 631                     (void)printf(",CE");
 632                 }
 633             }
 634
 635             if (ipds->ip->ip_ttl >= 1)
 636                 (void)printf(", ttl %3u", ipds->ip->ip_ttl);
 637
 638             /*
 639              * for the firewall guys, print id, offset.
 640              * On all but the last stick a "+" in the flags portion.
 641              * For unfragmented datagrams, note the don't fragment flag.
 642              */
 643
 644             (void)printf(", id %u, offset %u, flags [%s], proto: %s (%u)",
 645                          EXTRACT_16BITS(&ipds->ip->ip_id),
 646                          (ipds->off & 0x1fff) * 8,
 647                          bittok2str(ip_frag_values, "none", ipds->off&0xe000 ),
 648                          tok2str(ipproto_values,"unknown",ipds->ip->ip_p),
 649                          ipds->ip->ip_p);
 650
 651             (void)printf(", length: %u", EXTRACT_16BITS(&ipds->ip->ip_len));
 652
 653             if ((hlen - sizeof(struct ip)) > 0) {
 654                 printf(", options (");
 655                 ip_optprint((u_char *)(ipds->ip + 1), hlen - sizeof(struct ip));
 656                 printf(")");
 657             }
 658
 659             if ((u_char *)ipds->ip + hlen <= snapend) {
 660                 sum = in_cksum((const u_short *)ipds->ip, hlen, 0);
 661                 if (sum != 0) {
 662                     ip_sum = EXTRACT_16BITS(&ipds->ip->ip_sum);
 663                     (void)printf(", bad cksum %x (->%x)!", ip_sum,
 664                              in_cksum_shouldbe(ip_sum, sum));
 665                 }
 666             }
 667
 668             printf(") ");
 669         }
 670
 671         /*
 672          * If this is fragment zero, hand it to the next higher
 673          * level protocol.
 674          */
 675         if ((ipds->off & 0x1fff) == 0) {
 676                 ipds->cp = (const u_char *)ipds->ip + hlen;
 677                 ipds->nh = ipds->ip->ip_p;
 678
 679                 if (ipds->nh != IPPROTO_TCP && ipds->nh != IPPROTO_UDP &&
 680                     ipds->nh != IPPROTO_SCTP && ipds->nh != IPPROTO_DCCP) {
 681                         (void)printf("%s > %s: ",
 682                                      ipaddr_string(&ipds->ip->ip_src),
 683                                      ipaddr_string(&ipds->ip->ip_dst));
 684                 }
 685                 ip_print_demux(ndo, ipds);
 686         } else {
 687             /* Ultra quiet now means that all this stuff should be suppressed */
 688             if (qflag > 1) return;
 689
 690             /*
 691              * if this isn't the first frag, we're missing the
 692              * next level protocol header.  print the ip addr
 693              * and the protocol.
 694              */
 695             if (ipds->off & 0x1fff) {
 696                 (void)printf("%s > %s:", ipaddr_string(&ipds->ip->ip_src),
 697                              ipaddr_string(&ipds->ip->ip_dst));
 698                 if ((proto = getprotobynumber(ipds->ip->ip_p)) != NULL)
 699                     (void)printf(" %s", proto->p_name);
 700                 else
 701                     (void)printf(" ip-proto-%d", ipds->ip->ip_p);
 702             }
 703         }
 704 }
 705
 706 void
 707 ipN_print(register const u_char *bp, register u_int length)
 708 {
 709         struct ip *ip, hdr;
 710
 711         ip = (struct ip *)bp;
 712         if (length < 4) {
 713                 (void)printf("truncated-ip %d", length);
 714                 return;
 715         }
 716         memcpy (&hdr, (char *)ip, 4);
 717         switch (IP_V(&hdr)) {
 718         case 4:
 719                 ip_print (gndo, bp, length);
 720                 return;
 721 #ifdef INET6
 722         case 6:
 723                 ip6_print (bp, length);
 724                 return;
 725 #endif
 726         default:
 727                 (void)printf("unknown ip %d", IP_V(&hdr));
 728                 return;
 729         }
 730 }
 731
 732 /*
 733  * Local Variables:
 734  * c-style: whitesmith
 735  * c-basic-offset: 8
 736  * End:
 737  */
 738
 739