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) << 2);
 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 int
 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                         ND_PRINT("[|AH]");
 353                         break;
 354                 }
 355                 ipds->nh = EXTRACT_U_1(ipds->cp);
 356                 ipds->advance = ah_print(ndo, ipds->cp);
 357                 if (ipds->advance <= 0)
 358                         break;
 359                 ipds->cp += ipds->advance;
 360                 ipds->len -= ipds->advance;
 361                 goto again;
 362
 363         case IPPROTO_ESP:
 364         {
 365                 u_int enh, padlen;
 366                 ipds->advance = esp_print(ndo, ipds->cp, ipds->len,
 367                                     (const u_char *)ipds->ip,
 368                                     &enh, &padlen);
 369                 if (ipds->advance <= 0)
 370                         break;
 371                 ipds->cp += ipds->advance;
 372                 ipds->len -= ipds->advance + padlen;
 373                 ipds->nh = enh & 0xff;
 374                 goto again;
 375         }
 376
 377         case IPPROTO_IPCOMP:
 378         {
 379                 ipcomp_print(ndo, ipds->cp);
 380                 /*
 381                  * Either this has decompressed the payload and
 382                  * printed it, in which case there's nothing more
 383                  * to do, or it hasn't, in which case there's
 384                  * nothing more to do.
 385                  */
 386                 break;
 387         }
 388
 389         case IPPROTO_SCTP:
 390                 sctp_print(ndo, ipds->cp, (const u_char *)ipds->ip, ipds->len);
 391                 break;
 392
 393         case IPPROTO_DCCP:
 394                 dccp_print(ndo, ipds->cp, (const u_char *)ipds->ip, ipds->len);
 395                 break;
 396
 397         case IPPROTO_TCP:
 398                 /* pass on the MF bit plus the offset to detect fragments */
 399                 tcp_print(ndo, ipds->cp, ipds->len, (const u_char *)ipds->ip,
 400                           ipds->off & (IP_MF|IP_OFFMASK));
 401                 break;
 402
 403         case IPPROTO_UDP:
 404                 /* pass on the MF bit plus the offset to detect fragments */
 405                 udp_print(ndo, ipds->cp, ipds->len, (const u_char *)ipds->ip,
 406                           ipds->off & (IP_MF|IP_OFFMASK));
 407                 break;
 408
 409         case IPPROTO_ICMP:
 410                 /* pass on the MF bit plus the offset to detect fragments */
 411                 icmp_print(ndo, ipds->cp, ipds->len, (const u_char *)ipds->ip,
 412                            ipds->off & (IP_MF|IP_OFFMASK));
 413                 break;
 414
 415         case IPPROTO_PIGP:
 416                 /*
 417                  * XXX - the current IANA protocol number assignments
 418                  * page lists 9 as "any private interior gateway
 419                  * (used by Cisco for their IGRP)" and 88 as
 420                  * "EIGRP" from Cisco.
 421                  *
 422                  * Recent BSD <netinet/in.h> headers define
 423                  * IP_PROTO_PIGP as 9 and IP_PROTO_IGRP as 88.
 424                  * We define IP_PROTO_PIGP as 9 and
 425                  * IP_PROTO_EIGRP as 88; those names better
 426                  * match was the current protocol number
 427                  * assignments say.
 428                  */
 429                 igrp_print(ndo, ipds->cp, ipds->len);
 430                 break;
 431
 432         case IPPROTO_EIGRP:
 433                 eigrp_print(ndo, ipds->cp, ipds->len);
 434                 break;
 435
 436         case IPPROTO_ND:
 437                 ND_PRINT(" nd %u", ipds->len);
 438                 break;
 439
 440         case IPPROTO_EGP:
 441                 egp_print(ndo, ipds->cp, ipds->len);
 442                 break;
 443
 444         case IPPROTO_OSPF:
 445                 ospf_print(ndo, ipds->cp, ipds->len, (const u_char *)ipds->ip);
 446                 break;
 447
 448         case IPPROTO_IGMP:
 449                 igmp_print(ndo, ipds->cp, ipds->len);
 450                 break;
 451
 452         case IPPROTO_IPV4:
 453                 /* DVMRP multicast tunnel (ip-in-ip encapsulation) */
 454                 ip_print(ndo, ipds->cp, ipds->len);
 455                 if (! ndo->ndo_vflag) {
 456                         ND_PRINT(" (ipip-proto-4)");
 457                         return;
 458                 }
 459                 break;
 460
 461         case IPPROTO_IPV6:
 462                 /* ip6-in-ip encapsulation */
 463                 ip6_print(ndo, ipds->cp, ipds->len);
 464                 break;
 465
 466         case IPPROTO_RSVP:
 467                 rsvp_print(ndo, ipds->cp, ipds->len);
 468                 break;
 469
 470         case IPPROTO_GRE:
 471                 /* do it */
 472                 gre_print(ndo, ipds->cp, ipds->len);
 473                 break;
 474
 475         case IPPROTO_MOBILE:
 476                 mobile_print(ndo, ipds->cp, ipds->len);
 477                 break;
 478
 479         case IPPROTO_PIM:
 480                 pim_print(ndo, ipds->cp, ipds->len, (const u_char *)ipds->ip);
 481                 break;
 482
 483         case IPPROTO_VRRP:
 484                 if (ndo->ndo_packettype == PT_CARP) {
 485                         if (ndo->ndo_vflag)
 486                                 ND_PRINT("carp %s > %s: ",
 487                                              ipaddr_string(ndo, ipds->ip->ip_src),
 488                                              ipaddr_string(ndo, ipds->ip->ip_dst));
 489                         carp_print(ndo, ipds->cp, ipds->len,
 490                                 EXTRACT_U_1(ipds->ip->ip_ttl));
 491                 } else {
 492                         if (ndo->ndo_vflag)
 493                                 ND_PRINT("vrrp %s > %s: ",
 494                                              ipaddr_string(ndo, ipds->ip->ip_src),
 495                                              ipaddr_string(ndo, ipds->ip->ip_dst));
 496                         vrrp_print(ndo, ipds->cp, ipds->len,
 497                                 (const u_char *)ipds->ip,
 498                                 EXTRACT_U_1(ipds->ip->ip_ttl));
 499                 }
 500                 break;
 501
 502         case IPPROTO_PGM:
 503                 pgm_print(ndo, ipds->cp, ipds->len, (const u_char *)ipds->ip);
 504                 break;
 505
 506         default:
 507                 if (ndo->ndo_nflag==0 && (p_name = netdb_protoname(ipds->nh)) != NULL)
 508                         ND_PRINT(" %s", p_name);
 509                 else
 510                         ND_PRINT(" ip-proto-%u", ipds->nh);
 511                 ND_PRINT(" %u", ipds->len);
 512                 break;
 513         }
 514 }
 515
 516 void
 517 ip_inner_print(netdissect_options *ndo,
 518                const u_char *bp,
 519                u_int length, u_int nh,
 520                const u_char *bp2)
 521 {
 522         struct ip_print_demux_state  ipd;
 523
 524         ipd.ip = (const struct ip *)bp2;
 525         ipd.cp = bp;
 526         ipd.len  = length;
 527         ipd.off  = 0;
 528         ipd.nh   = nh;
 529         ipd.advance = 0;
 530
 531         ip_print_demux(ndo, &ipd);
 532 }
 533
 534
 535 /*
 536  * print an IP datagram.
 537  */
 538 void
 539 ip_print(netdissect_options *ndo,
 540          const u_char *bp,
 541          u_int length)
 542 {
 543         struct ip_print_demux_state  ipd;
 544         struct ip_print_demux_state *ipds=&ipd;
 545         const u_char *ipend;
 546         u_int hlen;
 547         struct cksum_vec vec[1];
 548         uint8_t ip_tos, ip_ttl, ip_proto;
 549         uint16_t sum, ip_sum;
 550         const char *p_name;
 551         int truncated = 0;
 552
 553         ndo->ndo_protocol = "ip";
 554         ipds->ip = (const struct ip *)bp;
 555         ND_TCHECK_1(ipds->ip->ip_vhl);
 556         if (IP_V(ipds->ip) != 4) { /* print version and fail if != 4 */
 557             if (IP_V(ipds->ip) == 6)
 558               ND_PRINT("IP6, wrong link-layer encapsulation");
 559             else
 560               ND_PRINT("IP%u", IP_V(ipds->ip));
 561             nd_print_invalid(ndo);
 562             return;
 563         }
 564         if (!ndo->ndo_eflag)
 565                 ND_PRINT("IP ");
 566
 567         ND_TCHECK_SIZE(ipds->ip);
 568         if (length < sizeof (struct ip)) {
 569                 ND_PRINT("truncated-ip %u", length);
 570                 return;
 571         }
 572         hlen = IP_HL(ipds->ip) * 4;
 573         if (hlen < sizeof (struct ip)) {
 574                 ND_PRINT("bad-hlen %u", hlen);
 575                 return;
 576         }
 577
 578         ipds->len = EXTRACT_BE_U_2(ipds->ip->ip_len);
 579         if (length < ipds->len)
 580                 ND_PRINT("truncated-ip - %u bytes missing! ",
 581                         ipds->len - length);
 582         if (ipds->len < hlen) {
 583 #ifdef GUESS_TSO
 584             if (ipds->len) {
 585                 ND_PRINT("bad-len %u", ipds->len);
 586                 return;
 587             }
 588             else {
 589                 /* we guess that it is a TSO send */
 590                 ipds->len = length;
 591             }
 592 #else
 593             ND_PRINT("bad-len %u", ipds->len);
 594             return;
 595 #endif /* GUESS_TSO */
 596         }
 597
 598         /*
 599          * Cut off the snapshot length to the end of the IP payload.
 600          */
 601         ipend = bp + ipds->len;
 602         if (ipend < ndo->ndo_snapend)
 603                 ndo->ndo_snapend = ipend;
 604
 605         ipds->len -= hlen;
 606
 607         ipds->off = EXTRACT_BE_U_2(ipds->ip->ip_off);
 608
 609         ip_proto = EXTRACT_U_1(ipds->ip->ip_p);
 610
 611         if (ndo->ndo_vflag) {
 612             ip_tos = EXTRACT_U_1(ipds->ip->ip_tos);
 613             ND_PRINT("(tos 0x%x", ip_tos);
 614             /* ECN bits */
 615             switch (ip_tos & 0x03) {
 616
 617             case 0:
 618                 break;
 619
 620             case 1:
 621                 ND_PRINT(",ECT(1)");
 622                 break;
 623
 624             case 2:
 625                 ND_PRINT(",ECT(0)");
 626                 break;
 627
 628             case 3:
 629                 ND_PRINT(",CE");
 630                 break;
 631             }
 632
 633             ip_ttl = EXTRACT_U_1(ipds->ip->ip_ttl);
 634             if (ip_ttl >= 1)
 635                 ND_PRINT(", ttl %u", ip_ttl);
 636
 637             /*
 638              * for the firewall guys, print id, offset.
 639              * On all but the last stick a "+" in the flags portion.
 640              * For unfragmented datagrams, note the don't fragment flag.
 641              */
 642             ND_PRINT(", id %u, offset %u, flags [%s], proto %s (%u)",
 643                          EXTRACT_BE_U_2(ipds->ip->ip_id),
 644                          (ipds->off & 0x1fff) * 8,
 645                          bittok2str(ip_frag_values, "none", ipds->off&0xe000),
 646                          tok2str(ipproto_values, "unknown", ip_proto),
 647                          ip_proto);
 648
 649             ND_PRINT(", length %u", EXTRACT_BE_U_2(ipds->ip->ip_len));
 650
 651             if ((hlen - sizeof(struct ip)) > 0) {
 652                 ND_PRINT(", options (");
 653                 if (ip_optprint(ndo, (const u_char *)(ipds->ip + 1),
 654                     hlen - sizeof(struct ip)) == -1) {
 655                         ND_PRINT(" [truncated-option]");
 656                         truncated = 1;
 657                 }
 658                 ND_PRINT(")");
 659             }
 660
 661             if (!ndo->ndo_Kflag && (const u_char *)ipds->ip + hlen <= ndo->ndo_snapend) {
 662                 vec[0].ptr = (const uint8_t *)(const void *)ipds->ip;
 663                 vec[0].len = hlen;
 664                 sum = in_cksum(vec, 1);
 665                 if (sum != 0) {
 666                     ip_sum = EXTRACT_BE_U_2(ipds->ip->ip_sum);
 667                     ND_PRINT(", bad cksum %x (->%x)!", ip_sum,
 668                              in_cksum_shouldbe(ip_sum, sum));
 669                 }
 670             }
 671
 672             ND_PRINT(")\n    ");
 673             if (truncated) {
 674                 ND_PRINT("%s > %s: ",
 675                          ipaddr_string(ndo, ipds->ip->ip_src),
 676                          ipaddr_string(ndo, ipds->ip->ip_dst));
 677                 goto trunc;
 678             }
 679         }
 680
 681         /*
 682          * If this is fragment zero, hand it to the next higher
 683          * level protocol.
 684          */
 685         if ((ipds->off & 0x1fff) == 0) {
 686                 ipds->cp = (const u_char *)ipds->ip + hlen;
 687                 ipds->nh = EXTRACT_U_1(ipds->ip->ip_p);
 688
 689                 if (ipds->nh != IPPROTO_TCP && ipds->nh != IPPROTO_UDP &&
 690                     ipds->nh != IPPROTO_SCTP && ipds->nh != IPPROTO_DCCP) {
 691                         ND_PRINT("%s > %s: ",
 692                                      ipaddr_string(ndo, ipds->ip->ip_src),
 693                                      ipaddr_string(ndo, ipds->ip->ip_dst));
 694                 }
 695                 ip_print_demux(ndo, ipds);
 696         } else {
 697                 /*
 698                  * Ultra quiet now means that all this stuff should be
 699                  * suppressed.
 700                  */
 701                 if (ndo->ndo_qflag > 1)
 702                         return;
 703
 704                 /*
 705                  * This isn't the first frag, so we're missing the
 706                  * next level protocol header.  print the ip addr
 707                  * and the protocol.
 708                  */
 709                 ND_PRINT("%s > %s:", ipaddr_string(ndo, ipds->ip->ip_src),
 710                           ipaddr_string(ndo, ipds->ip->ip_dst));
 711                 if (!ndo->ndo_nflag && (p_name = netdb_protoname(ip_proto)) != NULL)
 712                         ND_PRINT(" %s", p_name);
 713                 else
 714                         ND_PRINT(" ip-proto-%u", ip_proto);
 715         }
 716         return;
 717
 718 trunc:
 719         nd_print_trunc(ndo);
 720         return;
 721 }
 722
 723 void
 724 ipN_print(netdissect_options *ndo, const u_char *bp, u_int length)
 725 {
 726         ndo->ndo_protocol = "ipN";
 727         if (length < 1) {
 728                 ND_PRINT("truncated-ip %u", length);
 729                 return;
 730         }
 731
 732         ND_TCHECK_1(bp);
 733         switch (EXTRACT_U_1(bp) & 0xF0) {
 734         case 0x40:
 735                 ip_print(ndo, bp, length);
 736                 break;
 737         case 0x60:
 738                 ip6_print(ndo, bp, length);
 739                 break;
 740         default:
 741                 ND_PRINT("unknown ip %u", (EXTRACT_U_1(bp) & 0xF0) >> 4);
 742                 break;
 743         }
 744         return;
 745
 746 trunc:
 747         nd_print_trunc(ndo);
 748         return;
 749 }