The Tcpdump Group git mirrors - tcpdump/blob - 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 /* \summary: IP printer */
  23
  24 #ifdef HAVE_CONFIG_H
  25 #include <config.h>
  26 #endif
  27
  28 #include "netdissect-stdinc.h"
  29
  30 #include <string.h>
  31
  32 #include "netdissect.h"
  33 #include "addrtoname.h"
  34 #include "extract.h"
  35
  36 #include "ip.h"
  37 #include "ipproto.h"
  38
  39
  40 static const struct tok ip_option_values[] = {
  41     { IPOPT_EOL, "EOL" },
  42     { IPOPT_NOP, "NOP" },
  43     { IPOPT_TS, "timestamp" },
  44     { IPOPT_SECURITY, "security" },
  45     { IPOPT_RR, "RR" },
  46     { IPOPT_SSRR, "SSRR" },
  47     { IPOPT_LSRR, "LSRR" },
  48     { IPOPT_RA, "RA" },
  49     { IPOPT_RFC1393, "traceroute" },
  50     { 0, NULL }
  51 };
  52
  53 /*
  54  * print the recorded route in an IP RR, LSRR or SSRR option.
  55  */
  56 static int
  57 ip_printroute(netdissect_options *ndo,
  58               const u_char *cp, u_int length)
  59 {
  60         u_int ptr;
  61         u_int len;
  62
  63         if (length < 3) {
  64                 ND_PRINT(" [bad length %u]", length);
  65                 return (0);
  66         }
  67         if ((length + 1) & 3)
  68                 ND_PRINT(" [bad length %u]", length);
  69         ND_TCHECK_1(cp + 2);
  70         ptr = EXTRACT_U_1(cp + 2) - 1;
  71         if (ptr < 3 || ((ptr + 1) & 3) || ptr > length + 1)
  72                 ND_PRINT(" [bad ptr %u]", EXTRACT_U_1(cp + 2));
  73
  74         for (len = 3; len < length; len += 4) {
  75                 ND_TCHECK_4(cp + len);
  76                 ND_PRINT(" %s", ipaddr_string(ndo, cp + len));
  77                 if (ptr > len)
  78                         ND_PRINT(",");
  79         }
  80         return (0);
  81
  82 trunc:
  83         return (-1);
  84 }
  85
  86 /*
  87  * If source-routing is present and valid, return the final destination.
  88  * Otherwise, return IP destination.
  89  *
  90  * This is used for UDP and TCP pseudo-header in the checksum
  91  * calculation.
  92  */
  93 static uint32_t
  94 ip_finddst(netdissect_options *ndo,
  95            const struct ip *ip)
  96 {
  97         u_int length;
  98         u_int len;
  99         const u_char *cp;
 100
 101         cp = (const u_char *)(ip + 1);
 102         length = IP_HL(ip) * 4;
 103         if (length < sizeof(struct ip))
 104                 goto trunc;
 105         length -= sizeof(struct ip);
 106
 107         for (; length != 0; cp += len, length -= len) {
 108                 int tt;
 109
 110                 ND_TCHECK_1(cp);
 111                 tt = EXTRACT_U_1(cp);
 112                 if (tt == IPOPT_EOL)
 113                         break;
 114                 else if (tt == IPOPT_NOP)
 115                         len = 1;
 116                 else {
 117                         ND_TCHECK_1(cp + 1);
 118                         len = EXTRACT_U_1(cp + 1);
 119                         if (len < 2)
 120                                 break;
 121                 }
 122                 if (length < len)
 123                         goto trunc;
 124                 ND_TCHECK_LEN(cp, len);
 125                 switch (tt) {
 126
 127                 case IPOPT_SSRR:
 128                 case IPOPT_LSRR:
 129                         if (len < 7)
 130                                 break;
 131                         return (EXTRACT_IPV4_TO_NETWORK_ORDER(cp + len - 4));
 132                 }
 133         }
 134 trunc:
 135         return (EXTRACT_IPV4_TO_NETWORK_ORDER(ip->ip_dst));
 136 }
 137
 138 /*
 139  * Compute a V4-style checksum by building a pseudoheader.
 140  */
 141 uint16_t
 142 nextproto4_cksum(netdissect_options *ndo,
 143                  const struct ip *ip, const uint8_t *data,
 144                  u_int len, u_int covlen, u_int next_proto)
 145 {
 146         struct phdr {
 147                 uint32_t src;
 148                 uint32_t dst;
 149                 u_char mbz;
 150                 u_char proto;
 151                 uint16_t len;
 152         } ph;
 153         struct cksum_vec vec[2];
 154
 155         /* pseudo-header.. */
 156         ph.len = htons((uint16_t)len);
 157         ph.mbz = 0;
 158         ph.proto = next_proto;
 159         ph.src = EXTRACT_IPV4_TO_NETWORK_ORDER(ip->ip_src);
 160         if (IP_HL(ip) == 5)
 161                 ph.dst = EXTRACT_IPV4_TO_NETWORK_ORDER(ip->ip_dst);
 162         else
 163                 ph.dst = ip_finddst(ndo, ip);
 164
 165         vec[0].ptr = (const uint8_t *)(void *)&ph;
 166         vec[0].len = sizeof(ph);
 167         vec[1].ptr = data;
 168         vec[1].len = covlen;
 169         return (in_cksum(vec, 2));
 170 }
 171
 172 static int
 173 ip_printts(netdissect_options *ndo,
 174            const u_char *cp, u_int length)
 175 {
 176         u_int ptr;
 177         u_int len;
 178         u_int hoplen;
 179         const char *type;
 180
 181         if (length < 4) {
 182                 ND_PRINT("[bad length %u]", length);
 183                 return (0);
 184         }
 185         ND_PRINT(" TS{");
 186         ND_TCHECK_1(cp + 3);
 187         hoplen = ((EXTRACT_U_1(cp + 3) & 0xF) != IPOPT_TS_TSONLY) ? 8 : 4;
 188         if ((length - 4) & (hoplen-1))
 189                 ND_PRINT("[bad length %u]", length);
 190         ND_TCHECK_1(cp + 2);
 191         ptr = EXTRACT_U_1(cp + 2) - 1;
 192         len = 0;
 193         if (ptr < 4 || ((ptr - 4) & (hoplen-1)) || ptr > length + 1)
 194                 ND_PRINT("[bad ptr %u]", EXTRACT_U_1(cp + 2));
 195         ND_TCHECK_1(cp + 3);
 196         switch (EXTRACT_U_1(cp + 3)&0xF) {
 197         case IPOPT_TS_TSONLY:
 198                 ND_PRINT("TSONLY");
 199                 break;
 200         case IPOPT_TS_TSANDADDR:
 201                 ND_PRINT("TS+ADDR");
 202                 break;
 203         /*
 204          * prespecified should really be 3, but some ones might send 2
 205          * instead, and the IPOPT_TS_PRESPEC constant can apparently
 206          * have both values, so we have to hard-code it here.
 207          */
 208
 209         case 2:
 210                 ND_PRINT("PRESPEC2.0");
 211                 break;
 212         case 3:                 /* IPOPT_TS_PRESPEC */
 213                 ND_PRINT("PRESPEC");
 214                 break;
 215         default:
 216                 ND_PRINT("[bad ts type %u]", EXTRACT_U_1(cp + 3)&0xF);
 217                 goto done;
 218         }
 219
 220         type = " ";
 221         for (len = 4; len < length; len += hoplen) {
 222                 if (ptr == len)
 223                         type = " ^ ";
 224                 ND_TCHECK_LEN(cp + len, hoplen);
 225                 ND_PRINT("%s%u@%s", type, EXTRACT_BE_U_4(cp + len + hoplen - 4),
 226                           hoplen!=8 ? "" : ipaddr_string(ndo, cp + len));
 227                 type = " ";
 228         }
 229
 230 done:
 231         ND_PRINT("%s", ptr == len ? " ^ " : "");
 232
 233         if (EXTRACT_U_1(cp + 3) >> 4)
 234                 ND_PRINT(" [%u hops not recorded]} ", EXTRACT_U_1(cp + 3)>>4);
 235         else
 236                 ND_PRINT("}");
 237         return (0);
 238
 239 trunc:
 240         return (-1);
 241 }
 242
 243 /*
 244  * print IP options.
 245    If truncated return -1, else 0.
 246  */
 247 static int
 248 ip_optprint(netdissect_options *ndo,
 249             const u_char *cp, u_int length)
 250 {
 251         u_int option_len;
 252         const char *sep = "";
 253
 254         for (; length > 0; cp += option_len, length -= option_len) {
 255                 u_int option_code;
 256
 257                 ND_PRINT("%s", sep);
 258                 sep = ",";
 259
 260                 ND_TCHECK_1(cp);
 261                 option_code = EXTRACT_U_1(cp);
 262
 263                 ND_PRINT("%s",
 264                           tok2str(ip_option_values,"unknown %u",option_code));
 265
 266                 if (option_code == IPOPT_NOP ||
 267                     option_code == IPOPT_EOL)
 268                         option_len = 1;
 269
 270                 else {
 271                         ND_TCHECK_1(cp + 1);
 272                         option_len = EXTRACT_U_1(cp + 1);
 273                         if (option_len < 2) {
 274                                 ND_PRINT(" [bad length %u]", option_len);
 275                                 return 0;
 276                         }
 277                 }
 278
 279                 if (option_len > length) {
 280                         ND_PRINT(" [bad length %u]", option_len);
 281                         return 0;
 282                 }
 283
 284                 ND_TCHECK_LEN(cp, option_len);
 285
 286                 switch (option_code) {
 287                 case IPOPT_EOL:
 288                         return 0;
 289
 290                 case IPOPT_TS:
 291                         if (ip_printts(ndo, cp, option_len) == -1)
 292                                 goto trunc;
 293                         break;
 294
 295                 case IPOPT_RR:       /* fall through */
 296                 case IPOPT_SSRR:
 297                 case IPOPT_LSRR:
 298                         if (ip_printroute(ndo, cp, option_len) == -1)
 299                                 goto trunc;
 300                         break;
 301
 302                 case IPOPT_RA:
 303                         if (option_len < 4) {
 304                                 ND_PRINT(" [bad length %u]", option_len);
 305                                 break;
 306                         }
 307                         ND_TCHECK_1(cp + 3);
 308                         if (EXTRACT_BE_U_2(cp + 2) != 0)
 309                                 ND_PRINT(" value %u", EXTRACT_BE_U_2(cp + 2));
 310                         break;
 311
 312                 case IPOPT_NOP:       /* nothing to print - fall through */
 313                 case IPOPT_SECURITY:
 314                 default:
 315                         break;
 316                 }
 317         }
 318         return 0;
 319
 320 trunc:
 321         return -1;
 322 }
 323
 324 #define IP_RES 0x8000
 325
 326 static const struct tok ip_frag_values[] = {
 327         { IP_MF,        "+" },
 328         { IP_DF,        "DF" },
 329         { IP_RES,       "rsvd" }, /* The RFC3514 evil ;-) bit */
 330         { 0,            NULL }
 331 };
 332
 333 struct ip_print_demux_state {
 334         const struct ip *ip;
 335         const u_char *cp;
 336         u_int   len, off;
 337         u_char  nh;
 338         int     advance;
 339 };
 340
 341 static void
 342 ip_print_demux(netdissect_options *ndo,
 343                struct ip_print_demux_state *ipds)
 344 {
 345         const char *p_name;
 346
 347 again:
 348         switch (ipds->nh) {
 349
 350         case IPPROTO_AH:
 351                 if (!ND_TTEST_1(ipds->cp)) {
 352                         ndo->ndo_protocol = "ah";
 353                         nd_print_trunc(ndo);
 354                         break;
 355                 }
 356                 ipds->nh = EXTRACT_U_1(ipds->cp);
 357                 ipds->advance = ah_print(ndo, ipds->cp);
 358                 if (ipds->advance <= 0)
 359                         break;
 360                 ipds->cp += ipds->advance;
 361                 ipds->len -= ipds->advance;
 362                 goto again;
 363
 364         case IPPROTO_ESP:
 365         {
 366                 u_int enh, padlen;
 367                 ipds->advance = esp_print(ndo, ipds->cp, ipds->len,
 368                                     (const u_char *)ipds->ip,
 369                                     &enh, &padlen);
 370                 if (ipds->advance <= 0)
 371                         break;
 372                 ipds->cp += ipds->advance;
 373                 ipds->len -= ipds->advance + padlen;
 374                 ipds->nh = enh & 0xff;
 375                 goto again;
 376         }
 377
 378         case IPPROTO_IPCOMP:
 379         {
 380                 ipcomp_print(ndo, ipds->cp);
 381                 /*
 382                  * Either this has decompressed the payload and
 383                  * printed it, in which case there's nothing more
 384                  * to do, or it hasn't, in which case there's
 385                  * nothing more to do.
 386                  */
 387                 break;
 388         }
 389
 390         case IPPROTO_SCTP:
 391                 sctp_print(ndo, ipds->cp, (const u_char *)ipds->ip, ipds->len);
 392                 break;
 393
 394         case IPPROTO_DCCP:
 395                 dccp_print(ndo, ipds->cp, (const u_char *)ipds->ip, ipds->len);
 396                 break;
 397
 398         case IPPROTO_TCP:
 399                 /* pass on the MF bit plus the offset to detect fragments */
 400                 tcp_print(ndo, ipds->cp, ipds->len, (const u_char *)ipds->ip,
 401                           ipds->off & (IP_MF|IP_OFFMASK));
 402                 break;
 403
 404         case IPPROTO_UDP:
 405                 /* pass on the MF bit plus the offset to detect fragments */
 406                 udp_print(ndo, ipds->cp, ipds->len, (const u_char *)ipds->ip,
 407                           ipds->off & (IP_MF|IP_OFFMASK));
 408                 break;
 409
 410         case IPPROTO_ICMP:
 411                 /* pass on the MF bit plus the offset to detect fragments */
 412                 icmp_print(ndo, ipds->cp, ipds->len, (const u_char *)ipds->ip,
 413                            ipds->off & (IP_MF|IP_OFFMASK));
 414                 break;
 415
 416         case IPPROTO_PIGP:
 417                 /*
 418                  * XXX - the current IANA protocol number assignments
 419                  * page lists 9 as "any private interior gateway
 420                  * (used by Cisco for their IGRP)" and 88 as
 421                  * "EIGRP" from Cisco.
 422                  *
 423                  * Recent BSD <netinet/in.h> headers define
 424                  * IP_PROTO_PIGP as 9 and IP_PROTO_IGRP as 88.
 425                  * We define IP_PROTO_PIGP as 9 and
 426                  * IP_PROTO_EIGRP as 88; those names better
 427                  * match was the current protocol number
 428                  * assignments say.
 429                  */
 430                 igrp_print(ndo, ipds->cp, ipds->len);
 431                 break;
 432
 433         case IPPROTO_EIGRP:
 434                 eigrp_print(ndo, ipds->cp, ipds->len);
 435                 break;
 436
 437         case IPPROTO_ND:
 438                 ND_PRINT(" nd %u", ipds->len);
 439                 break;
 440
 441         case IPPROTO_EGP:
 442                 egp_print(ndo, ipds->cp, ipds->len);
 443                 break;
 444
 445         case IPPROTO_OSPF:
 446                 ospf_print(ndo, ipds->cp, ipds->len, (const u_char *)ipds->ip);
 447                 break;
 448
 449         case IPPROTO_IGMP:
 450                 igmp_print(ndo, ipds->cp, ipds->len);
 451                 break;
 452
 453         case IPPROTO_IPV4:
 454                 /* DVMRP multicast tunnel (ip-in-ip encapsulation) */
 455                 ip_print(ndo, ipds->cp, ipds->len);
 456                 if (! ndo->ndo_vflag) {
 457                         ND_PRINT(" (ipip-proto-4)");
 458                         return;
 459                 }
 460                 break;
 461
 462         case IPPROTO_IPV6:
 463                 /* ip6-in-ip encapsulation */
 464                 ip6_print(ndo, ipds->cp, ipds->len);
 465                 break;
 466
 467         case IPPROTO_RSVP:
 468                 rsvp_print(ndo, ipds->cp, ipds->len);
 469                 break;
 470
 471         case IPPROTO_GRE:
 472                 /* do it */
 473                 gre_print(ndo, ipds->cp, ipds->len);
 474                 break;
 475
 476         case IPPROTO_MOBILE:
 477                 mobile_print(ndo, ipds->cp, ipds->len);
 478                 break;
 479
 480         case IPPROTO_PIM:
 481                 pim_print(ndo, ipds->cp, ipds->len, (const u_char *)ipds->ip);
 482                 break;
 483
 484         case IPPROTO_VRRP:
 485                 if (ndo->ndo_packettype == PT_CARP) {
 486                         if (ndo->ndo_vflag)
 487                                 ND_PRINT("carp %s > %s: ",
 488                                              ipaddr_string(ndo, ipds->ip->ip_src),
 489                                              ipaddr_string(ndo, ipds->ip->ip_dst));
 490                         carp_print(ndo, ipds->cp, ipds->len,
 491                                 EXTRACT_U_1(ipds->ip->ip_ttl));
 492                 } else {
 493                         if (ndo->ndo_vflag)
 494                                 ND_PRINT("vrrp %s > %s: ",
 495                                              ipaddr_string(ndo, ipds->ip->ip_src),
 496                                              ipaddr_string(ndo, ipds->ip->ip_dst));
 497                         vrrp_print(ndo, ipds->cp, ipds->len,
 498                                 (const u_char *)ipds->ip,
 499                                 EXTRACT_U_1(ipds->ip->ip_ttl));
 500                 }
 501                 break;
 502
 503         case IPPROTO_PGM:
 504                 pgm_print(ndo, ipds->cp, ipds->len, (const u_char *)ipds->ip);
 505                 break;
 506
 507         default:
 508                 if (ndo->ndo_nflag==0 && (p_name = netdb_protoname(ipds->nh)) != NULL)
 509                         ND_PRINT(" %s", p_name);
 510                 else
 511                         ND_PRINT(" ip-proto-%u", ipds->nh);
 512                 ND_PRINT(" %u", ipds->len);
 513                 break;
 514         }
 515 }
 516
 517 void
 518 ip_inner_print(netdissect_options *ndo,
 519                const u_char *bp,
 520                u_int length, u_int nh,
 521                const u_char *bp2)
 522 {
 523         struct ip_print_demux_state  ipd;
 524
 525         ipd.ip = (const struct ip *)bp2;
 526         ipd.cp = bp;
 527         ipd.len  = length;
 528         ipd.off  = 0;
 529         ipd.nh   = nh;
 530         ipd.advance = 0;
 531
 532         ip_print_demux(ndo, &ipd);
 533 }
 534
 535
 536 /*
 537  * print an IP datagram.
 538  */
 539 void
 540 ip_print(netdissect_options *ndo,
 541          const u_char *bp,
 542          u_int length)
 543 {
 544         struct ip_print_demux_state  ipd;
 545         struct ip_print_demux_state *ipds=&ipd;
 546         const u_char *ipend;
 547         u_int hlen;
 548         struct cksum_vec vec[1];
 549         uint8_t ip_tos, ip_ttl, ip_proto;
 550         uint16_t sum, ip_sum;
 551         const char *p_name;
 552         int truncated = 0;
 553
 554         ndo->ndo_protocol = "ip";
 555         ipds->ip = (const struct ip *)bp;
 556         ND_TCHECK_1(ipds->ip->ip_vhl);
 557         if (IP_V(ipds->ip) != 4) { /* print version and fail if != 4 */
 558             if (IP_V(ipds->ip) == 6)
 559               ND_PRINT("IP6, wrong link-layer encapsulation");
 560             else
 561               ND_PRINT("IP%u", IP_V(ipds->ip));
 562             nd_print_invalid(ndo);
 563             return;
 564         }
 565         if (!ndo->ndo_eflag)
 566                 ND_PRINT("IP ");
 567
 568         ND_TCHECK_SIZE(ipds->ip);
 569         if (length < sizeof (struct ip)) {
 570                 ND_PRINT("truncated-ip %u", length);
 571                 return;
 572         }
 573         hlen = IP_HL(ipds->ip) * 4;
 574         if (hlen < sizeof (struct ip)) {
 575                 ND_PRINT("bad-hlen %u", hlen);
 576                 return;
 577         }
 578
 579         ipds->len = EXTRACT_BE_U_2(ipds->ip->ip_len);
 580         if (length < ipds->len)
 581                 ND_PRINT("truncated-ip - %u bytes missing! ",
 582                         ipds->len - length);
 583         if (ipds->len < hlen) {
 584 #ifdef GUESS_TSO
 585             if (ipds->len) {
 586                 ND_PRINT("bad-len %u", ipds->len);
 587                 return;
 588             }
 589             else {
 590                 /* we guess that it is a TSO send */
 591                 ipds->len = length;
 592             }
 593 #else
 594             ND_PRINT("bad-len %u", ipds->len);
 595             return;
 596 #endif /* GUESS_TSO */
 597         }
 598
 599         /*
 600          * Cut off the snapshot length to the end of the IP payload.
 601          */
 602         ipend = bp + ipds->len;
 603         if (ipend < ndo->ndo_snapend)
 604                 ndo->ndo_snapend = ipend;
 605
 606         ipds->len -= hlen;
 607
 608         ipds->off = EXTRACT_BE_U_2(ipds->ip->ip_off);
 609
 610         ip_proto = EXTRACT_U_1(ipds->ip->ip_p);
 611
 612         if (ndo->ndo_vflag) {
 613             ip_tos = EXTRACT_U_1(ipds->ip->ip_tos);
 614             ND_PRINT("(tos 0x%x", ip_tos);
 615             /* ECN bits */
 616             switch (ip_tos & 0x03) {
 617
 618             case 0:
 619                 break;
 620
 621             case 1:
 622                 ND_PRINT(",ECT(1)");
 623                 break;
 624
 625             case 2:
 626                 ND_PRINT(",ECT(0)");
 627                 break;
 628
 629             case 3:
 630                 ND_PRINT(",CE");
 631                 break;
 632             }
 633
 634             ip_ttl = EXTRACT_U_1(ipds->ip->ip_ttl);
 635             if (ip_ttl >= 1)
 636                 ND_PRINT(", ttl %u", 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             ND_PRINT(", id %u, offset %u, flags [%s], proto %s (%u)",
 644                          EXTRACT_BE_U_2(ipds->ip->ip_id),
 645                          (ipds->off & 0x1fff) * 8,
 646                          bittok2str(ip_frag_values, "none", ipds->off&0xe000),
 647                          tok2str(ipproto_values, "unknown", ip_proto),
 648                          ip_proto);
 649
 650             ND_PRINT(", length %u", EXTRACT_BE_U_2(ipds->ip->ip_len));
 651
 652             if ((hlen - sizeof(struct ip)) > 0) {
 653                 ND_PRINT(", options (");
 654                 if (ip_optprint(ndo, (const u_char *)(ipds->ip + 1),
 655                     hlen - sizeof(struct ip)) == -1) {
 656                         ND_PRINT(" [truncated-option]");
 657                         truncated = 1;
 658                 }
 659                 ND_PRINT(")");
 660             }
 661
 662             if (!ndo->ndo_Kflag && (const u_char *)ipds->ip + hlen <= ndo->ndo_snapend) {
 663                 vec[0].ptr = (const uint8_t *)(const void *)ipds->ip;
 664                 vec[0].len = hlen;
 665                 sum = in_cksum(vec, 1);
 666                 if (sum != 0) {
 667                     ip_sum = EXTRACT_BE_U_2(ipds->ip->ip_sum);
 668                     ND_PRINT(", bad cksum %x (->%x)!", ip_sum,
 669                              in_cksum_shouldbe(ip_sum, sum));
 670                 }
 671             }
 672
 673             ND_PRINT(")\n    ");
 674             if (truncated) {
 675                 ND_PRINT("%s > %s: ",
 676                          ipaddr_string(ndo, ipds->ip->ip_src),
 677                          ipaddr_string(ndo, ipds->ip->ip_dst));
 678                 goto trunc;
 679             }
 680         }
 681
 682         /*
 683          * If this is fragment zero, hand it to the next higher
 684          * level protocol.
 685          */
 686         if ((ipds->off & 0x1fff) == 0) {
 687                 ipds->cp = (const u_char *)ipds->ip + hlen;
 688                 ipds->nh = EXTRACT_U_1(ipds->ip->ip_p);
 689
 690                 if (ipds->nh != IPPROTO_TCP && ipds->nh != IPPROTO_UDP &&
 691                     ipds->nh != IPPROTO_SCTP && ipds->nh != IPPROTO_DCCP) {
 692                         ND_PRINT("%s > %s: ",
 693                                      ipaddr_string(ndo, ipds->ip->ip_src),
 694                                      ipaddr_string(ndo, ipds->ip->ip_dst));
 695                 }
 696                 ip_print_demux(ndo, ipds);
 697         } else {
 698                 /*
 699                  * Ultra quiet now means that all this stuff should be
 700                  * suppressed.
 701                  */
 702                 if (ndo->ndo_qflag > 1)
 703                         return;
 704
 705                 /*
 706                  * This isn't the first frag, so we're missing the
 707                  * next level protocol header.  print the ip addr
 708                  * and the protocol.
 709                  */
 710                 ND_PRINT("%s > %s:", ipaddr_string(ndo, ipds->ip->ip_src),
 711                           ipaddr_string(ndo, ipds->ip->ip_dst));
 712                 if (!ndo->ndo_nflag && (p_name = netdb_protoname(ip_proto)) != NULL)
 713                         ND_PRINT(" %s", p_name);
 714                 else
 715                         ND_PRINT(" ip-proto-%u", ip_proto);
 716         }
 717         return;
 718
 719 trunc:
 720         nd_print_trunc(ndo);
 721         return;
 722 }
 723
 724 void
 725 ipN_print(netdissect_options *ndo, const u_char *bp, u_int length)
 726 {
 727         ndo->ndo_protocol = "ipN";
 728         if (length < 1) {
 729                 ND_PRINT("truncated-ip %u", length);
 730                 return;
 731         }
 732
 733         ND_TCHECK_1(bp);
 734         switch (EXTRACT_U_1(bp) & 0xF0) {
 735         case 0x40:
 736                 ip_print(ndo, bp, length);
 737                 break;
 738         case 0x60:
 739                 ip6_print(ndo, bp, length);
 740                 break;
 741         default:
 742                 ND_PRINT("unknown ip %u", (EXTRACT_U_1(bp) & 0xF0) >> 4);
 743                 break;
 744         }
 745         return;
 746
 747 trunc:
 748         nd_print_trunc(ndo);
 749         return;
 750 }