The Tcpdump Group git mirrors - tcpdump/blob - print-ip6.c

   1 /*
   2  * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994
   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-ip6.c,v 1.52 2007-09-21 07:05:33 hannes Exp $";
  25 #endif
  26
  27 #ifdef HAVE_CONFIG_H
  28 #include "config.h"
  29 #endif
  30
  31 #ifdef INET6
  32
  33 #include <tcpdump-stdinc.h>
  34
  35 #include <stdio.h>
  36 #include <stdlib.h>
  37 #include <string.h>
  38
  39 #include "netdissect.h"
  40 #include "interface.h"
  41 #include "addrtoname.h"
  42 #include "extract.h"
  43
  44 #include "ip6.h"
  45 #include "ipproto.h"
  46
  47 /*
  48  * Compute a V6-style checksum by building a pseudoheader.
  49  */
  50 int
  51 nextproto6_cksum(const struct ip6_hdr *ip6, const u_int8_t *data,
  52                  u_int len, u_int next_proto)
  53 {
  54         struct {
  55                 struct in6_addr ph_src;
  56                 struct in6_addr ph_dst;
  57                 u_int32_t       ph_len;
  58                 u_int8_t        ph_zero[3];
  59                 u_int8_t        ph_nxt;
  60         } ph;
  61         struct cksum_vec vec[2];
  62
  63         /* pseudo-header */
  64         memset(&ph, 0, sizeof(ph));
  65         ph.ph_src = ip6->ip6_src;
  66         ph.ph_dst = ip6->ip6_dst;
  67         ph.ph_len = htonl(len);
  68         ph.ph_nxt = next_proto;
  69
  70         vec[0].ptr = (const u_int8_t *)(void *)&ph;
  71         vec[0].len = sizeof(ph);
  72         vec[1].ptr = data;
  73         vec[1].len = len;
  74
  75         return in_cksum(vec, 2);
  76 }
  77
  78 /*
  79  * print an IP6 datagram.
  80  */
  81 void
  82 ip6_print(netdissect_options *ndo, const u_char *bp, u_int length)
  83 {
  84         register const struct ip6_hdr *ip6;
  85         register int advance;
  86         u_int len;
  87         const u_char *ipend;
  88         register const u_char *cp;
  89         register u_int payload_len;
  90         int nh;
  91         int fragmented = 0;
  92         u_int flow;
  93
  94         ip6 = (const struct ip6_hdr *)bp;
  95
  96         TCHECK(*ip6);
  97         if (length < sizeof (struct ip6_hdr)) {
  98                 (void)ND_PRINT((ndo, "truncated-ip6 %u", length));
  99                 return;
 100         }
 101
 102         if (!ndo->ndo_eflag)
 103             ND_PRINT((ndo, "IP6 "));
 104
 105         if (IP6_VERSION(ip6) != 6) {
 106                 printf("version error: %u != 6", IP6_VERSION(ip6));
 107                 return;
 108         }
 109
 110         payload_len = EXTRACT_16BITS(&ip6->ip6_plen);
 111         len = payload_len + sizeof(struct ip6_hdr);
 112         if (length < len)
 113                 (void)ND_PRINT((ndo, "truncated-ip6 - %u bytes missing!",
 114                         len - length));
 115
 116         if (ndo->ndo_vflag) {
 117             flow = EXTRACT_32BITS(&ip6->ip6_flow);
 118             ND_PRINT((ndo, "("));
 119 #if 0
 120             /* rfc1883 */
 121             if (flow & 0x0f000000)
 122                 (void)ND_PRINT((ndo, "pri 0x%02x, ", (flow & 0x0f000000) >> 24));
 123             if (flow & 0x00ffffff)
 124                 (void)ND_PRINT((ndo, "flowlabel 0x%06x, ", flow & 0x00ffffff));
 125 #else
 126             /* RFC 2460 */
 127             if (flow & 0x0ff00000)
 128                 (void)ND_PRINT((ndo, "class 0x%02x, ", (flow & 0x0ff00000) >> 20));
 129             if (flow & 0x000fffff)
 130                 (void)ND_PRINT((ndo, "flowlabel 0x%05x, ", flow & 0x000fffff));
 131 #endif
 132
 133             (void)ND_PRINT((ndo, "hlim %u, next-header %s (%u) payload length: %u) ",
 134                          ip6->ip6_hlim,
 135                          tok2str(ipproto_values,"unknown",ip6->ip6_nxt),
 136                          ip6->ip6_nxt,
 137                          payload_len));
 138         }
 139
 140         /*
 141          * Cut off the snapshot length to the end of the IP payload.
 142          */
 143         ipend = bp + len;
 144         if (ipend < ndo->ndo_snapend)
 145                 ndo->ndo_snapend = ipend;
 146
 147         cp = (const u_char *)ip6;
 148         advance = sizeof(struct ip6_hdr);
 149         nh = ip6->ip6_nxt;
 150         while (cp < ndo->ndo_snapend && advance > 0) {
 151                 cp += advance;
 152                 len -= advance;
 153
 154                 if (cp == (const u_char *)(ip6 + 1) &&
 155                     nh != IPPROTO_TCP && nh != IPPROTO_UDP &&
 156                     nh != IPPROTO_DCCP && nh != IPPROTO_SCTP) {
 157                         (void)ND_PRINT((ndo, "%s > %s: ", ip6addr_string(&ip6->ip6_src),
 158                                      ip6addr_string(&ip6->ip6_dst)));
 159                 }
 160
 161                 switch (nh) {
 162                 case IPPROTO_HOPOPTS:
 163                         advance = hbhopt_print(cp);
 164                         nh = *cp;
 165                         break;
 166                 case IPPROTO_DSTOPTS:
 167                         advance = dstopt_print(cp);
 168                         nh = *cp;
 169                         break;
 170                 case IPPROTO_FRAGMENT:
 171                         advance = frag6_print(cp, (const u_char *)ip6);
 172                         if (ndo->ndo_snapend <= cp + advance)
 173                                 return;
 174                         nh = *cp;
 175                         fragmented = 1;
 176                         break;
 177
 178                 case IPPROTO_MOBILITY_OLD:
 179                 case IPPROTO_MOBILITY:
 180                         /*
 181                          * XXX - we don't use "advance"; the current
 182                          * "Mobility Support in IPv6" draft
 183                          * (draft-ietf-mobileip-ipv6-24) says that
 184                          * the next header field in a mobility header
 185                          * should be IPPROTO_NONE, but speaks of
 186                          * the possiblity of a future extension in
 187                          * which payload can be piggybacked atop a
 188                          * mobility header.
 189                          */
 190                         advance = mobility_print(cp, (const u_char *)ip6);
 191                         nh = *cp;
 192                         return;
 193                 case IPPROTO_ROUTING:
 194                         advance = rt6_print(cp, (const u_char *)ip6);
 195                         nh = *cp;
 196                         break;
 197                 case IPPROTO_SCTP:
 198                         sctp_print(cp, (const u_char *)ip6, len);
 199                         return;
 200                 case IPPROTO_DCCP:
 201                         dccp_print(cp, (const u_char *)ip6, len);
 202                         return;
 203                 case IPPROTO_TCP:
 204                         tcp_print(cp, len, (const u_char *)ip6, fragmented);
 205                         return;
 206                 case IPPROTO_UDP:
 207                         udp_print(cp, len, (const u_char *)ip6, fragmented);
 208                         return;
 209                 case IPPROTO_ICMPV6:
 210                         icmp6_print(ndo, cp, len, (const u_char *)ip6, fragmented);
 211                         return;
 212                 case IPPROTO_AH:
 213                         advance = ah_print(cp);
 214                         nh = *cp;
 215                         break;
 216                 case IPPROTO_ESP:
 217                     {
 218                         int enh, padlen;
 219                         advance = esp_print(ndo, cp, len, (const u_char *)ip6, &enh, &padlen);
 220                         nh = enh & 0xff;
 221                         len -= padlen;
 222                         break;
 223                     }
 224                 case IPPROTO_IPCOMP:
 225                     {
 226                         int enh;
 227                         advance = ipcomp_print(cp, &enh);
 228                         nh = enh & 0xff;
 229                         break;
 230                     }
 231
 232                 case IPPROTO_PIM:
 233                         pim_print(cp, len, nextproto6_cksum(ip6, cp, len,
 234                                                             IPPROTO_PIM));
 235                         return;
 236
 237                 case IPPROTO_OSPF:
 238                         ospf6_print(cp, len);
 239                         return;
 240
 241                 case IPPROTO_IPV6:
 242                         ip6_print(ndo, cp, len);
 243                         return;
 244
 245                 case IPPROTO_IPV4:
 246                         ip_print(ndo, cp, len);
 247                         return;
 248
 249                 case IPPROTO_PGM:
 250                         pgm_print(cp, len, (const u_char *)ip6);
 251                         return;
 252
 253                 case IPPROTO_GRE:
 254                         gre_print(cp, len);
 255                         return;
 256
 257                 case IPPROTO_RSVP:
 258                         rsvp_print(cp, len);
 259                         return;
 260
 261                 case IPPROTO_NONE:
 262                         (void)ND_PRINT((ndo, "no next header"));
 263                         return;
 264
 265                 default:
 266                         (void)ND_PRINT((ndo, "ip-proto-%d %d", nh, len));
 267                         return;
 268                 }
 269         }
 270
 271         return;
 272 trunc:
 273         (void)ND_PRINT((ndo, "[|ip6]"));
 274 }
 275
 276 #endif /* INET6 */