contrib/tcpdump/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         payload_len = EXTRACT_16BITS(&ip6->ip6_plen);
 106         len = payload_len + sizeof(struct ip6_hdr);
 107         if (length < len)
 108                 (void)ND_PRINT((ndo, "truncated-ip6 - %u bytes missing!",
 109                         len - length));
 110
 111         if (ndo->ndo_vflag) {
 112             flow = EXTRACT_32BITS(&ip6->ip6_flow);
 113             ND_PRINT((ndo, "("));
 114 #if 0
 115             /* rfc1883 */
 116             if (flow & 0x0f000000)
 117                 (void)ND_PRINT((ndo, "pri 0x%02x, ", (flow & 0x0f000000) >> 24));
 118             if (flow & 0x00ffffff)
 119                 (void)ND_PRINT((ndo, "flowlabel 0x%06x, ", flow & 0x00ffffff));
 120 #else
 121             /* RFC 2460 */
 122             if (flow & 0x0ff00000)
 123                 (void)ND_PRINT((ndo, "class 0x%02x, ", (flow & 0x0ff00000) >> 20));
 124             if (flow & 0x000fffff)
 125                 (void)ND_PRINT((ndo, "flowlabel 0x%05x, ", flow & 0x000fffff));
 126 #endif
 127
 128             (void)ND_PRINT((ndo, "hlim %u, next-header %s (%u) payload length: %u) ",
 129                          ip6->ip6_hlim,
 130                          tok2str(ipproto_values,"unknown",ip6->ip6_nxt),
 131                          ip6->ip6_nxt,
 132                          payload_len));
 133         }
 134
 135         /*
 136          * Cut off the snapshot length to the end of the IP payload.
 137          */
 138         ipend = bp + len;
 139         if (ipend < ndo->ndo_snapend)
 140                 ndo->ndo_snapend = ipend;
 141
 142         cp = (const u_char *)ip6;
 143         advance = sizeof(struct ip6_hdr);
 144         nh = ip6->ip6_nxt;
 145         while (cp < ndo->ndo_snapend && advance > 0) {
 146                 cp += advance;
 147                 len -= advance;
 148
 149                 if (cp == (const u_char *)(ip6 + 1) &&
 150                     nh != IPPROTO_TCP && nh != IPPROTO_UDP &&
 151                     nh != IPPROTO_DCCP && nh != IPPROTO_SCTP) {
 152                         (void)ND_PRINT((ndo, "%s > %s: ", ip6addr_string(&ip6->ip6_src),
 153                                      ip6addr_string(&ip6->ip6_dst)));
 154                 }
 155
 156                 switch (nh) {
 157                 case IPPROTO_HOPOPTS:
 158                         advance = hbhopt_print(cp);
 159                         nh = *cp;
 160                         break;
 161                 case IPPROTO_DSTOPTS:
 162                         advance = dstopt_print(cp);
 163                         nh = *cp;
 164                         break;
 165                 case IPPROTO_FRAGMENT:
 166                         advance = frag6_print(cp, (const u_char *)ip6);
 167                         if (ndo->ndo_snapend <= cp + advance)
 168                                 return;
 169                         nh = *cp;
 170                         fragmented = 1;
 171                         break;
 172
 173                 case IPPROTO_MOBILITY_OLD:
 174                 case IPPROTO_MOBILITY:
 175                         /*
 176                          * XXX - we don't use "advance"; the current
 177                          * "Mobility Support in IPv6" draft
 178                          * (draft-ietf-mobileip-ipv6-24) says that
 179                          * the next header field in a mobility header
 180                          * should be IPPROTO_NONE, but speaks of
 181                          * the possiblity of a future extension in
 182                          * which payload can be piggybacked atop a
 183                          * mobility header.
 184                          */
 185                         advance = mobility_print(cp, (const u_char *)ip6);
 186                         nh = *cp;
 187                         return;
 188                 case IPPROTO_ROUTING:
 189                         advance = rt6_print(cp, (const u_char *)ip6);
 190                         nh = *cp;
 191                         break;
 192                 case IPPROTO_SCTP:
 193                         sctp_print(cp, (const u_char *)ip6, len);
 194                         return;
 195                 case IPPROTO_DCCP:
 196                         dccp_print(cp, (const u_char *)ip6, len);
 197                         return;
 198                 case IPPROTO_TCP:
 199                         tcp_print(cp, len, (const u_char *)ip6, fragmented);
 200                         return;
 201                 case IPPROTO_UDP:
 202                         udp_print(cp, len, (const u_char *)ip6, fragmented);
 203                         return;
 204                 case IPPROTO_ICMPV6:
 205                         icmp6_print(ndo, cp, len, (const u_char *)ip6, fragmented);
 206                         return;
 207                 case IPPROTO_AH:
 208                         advance = ah_print(cp);
 209                         nh = *cp;
 210                         break;
 211                 case IPPROTO_ESP:
 212                     {
 213                         int enh, padlen;
 214                         advance = esp_print(ndo, cp, len, (const u_char *)ip6, &enh, &padlen);
 215                         nh = enh & 0xff;
 216                         len -= padlen;
 217                         break;
 218                     }
 219                 case IPPROTO_IPCOMP:
 220                     {
 221                         int enh;
 222                         advance = ipcomp_print(cp, &enh);
 223                         nh = enh & 0xff;
 224                         break;
 225                     }
 226
 227                 case IPPROTO_PIM:
 228                         pim_print(cp, len, nextproto6_cksum(ip6, cp, len,
 229                                                             IPPROTO_PIM));
 230                         return;
 231
 232                 case IPPROTO_OSPF:
 233                         ospf6_print(cp, len);
 234                         return;
 235
 236                 case IPPROTO_IPV6:
 237                         ip6_print(ndo, cp, len);
 238                         return;
 239
 240                 case IPPROTO_IPV4:
 241                         ip_print(ndo, cp, len);
 242                         return;
 243
 244                 case IPPROTO_PGM:
 245                         pgm_print(cp, len, (const u_char *)ip6);
 246                         return;
 247
 248                 case IPPROTO_GRE:
 249                         gre_print(cp, len);
 250                         return;
 251
 252                 case IPPROTO_RSVP:
 253                         rsvp_print(cp, len);
 254                         return;
 255
 256                 case IPPROTO_NONE:
 257                         (void)ND_PRINT((ndo, "no next header"));
 258                         return;
 259
 260                 default:
 261                         (void)ND_PRINT((ndo, "ip-proto-%d %d", nh, len));
 262                         return;
 263                 }
 264         }
 265
 266         return;
 267 trunc:
 268         (void)ND_PRINT((ndo, "[|ip6]"));
 269 }
 270
 271 #endif /* INET6 */