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  * $FreeBSD$
  22  */
  23
  24 #ifndef lint
  25 static const char rcsid[] _U_ =
  26     "@(#) $Header: /tcpdump/master/tcpdump/print-ip6.c,v 1.52 2007-09-21 07:05:33 hannes Exp $";
  27 #endif
  28
  29 #ifdef HAVE_CONFIG_H
  30 #include "config.h"
  31 #endif
  32
  33 #ifdef INET6
  34
  35 #include <tcpdump-stdinc.h>
  36
  37 #include <stdio.h>
  38 #include <stdlib.h>
  39 #include <string.h>
  40
  41 #include "netdissect.h"
  42 #include "interface.h"
  43 #include "addrtoname.h"
  44 #include "extract.h"
  45
  46 #include "ip6.h"
  47 #include "ipproto.h"
  48
  49 /*
  50  * Compute a V6-style checksum by building a pseudoheader.
  51  */
  52 int
  53 nextproto6_cksum(const struct ip6_hdr *ip6, const u_int8_t *data,
  54                  u_int len, u_int next_proto)
  55 {
  56         struct {
  57                 struct in6_addr ph_src;
  58                 struct in6_addr ph_dst;
  59                 u_int32_t       ph_len;
  60                 u_int8_t        ph_zero[3];
  61                 u_int8_t        ph_nxt;
  62         } ph;
  63         struct cksum_vec vec[2];
  64
  65         /* pseudo-header */
  66         memset(&ph, 0, sizeof(ph));
  67         ph.ph_src = ip6->ip6_src;
  68         ph.ph_dst = ip6->ip6_dst;
  69         ph.ph_len = htonl(len);
  70         ph.ph_nxt = next_proto;
  71
  72         vec[0].ptr = (const u_int8_t *)(void *)&ph;
  73         vec[0].len = sizeof(ph);
  74         vec[1].ptr = data;
  75         vec[1].len = len;
  76
  77         return in_cksum(vec, 2);
  78 }
  79
  80 /*
  81  * print an IP6 datagram.
  82  */
  83 void
  84 ip6_print(netdissect_options *ndo, const u_char *bp, u_int length)
  85 {
  86         register const struct ip6_hdr *ip6;
  87         register int advance;
  88         u_int len;
  89         const u_char *ipend;
  90         register const u_char *cp;
  91         register u_int payload_len;
  92         int nh;
  93         int fragmented = 0;
  94         u_int flow;
  95
  96         ip6 = (const struct ip6_hdr *)bp;
  97
  98         TCHECK(*ip6);
  99         if (length < sizeof (struct ip6_hdr)) {
 100                 (void)ND_PRINT((ndo, "truncated-ip6 %u", length));
 101                 return;
 102         }
 103
 104         if (!ndo->ndo_eflag)
 105             ND_PRINT((ndo, "IP6 "));
 106
 107         payload_len = EXTRACT_16BITS(&ip6->ip6_plen);
 108         len = payload_len + sizeof(struct ip6_hdr);
 109         if (length < len)
 110                 (void)ND_PRINT((ndo, "truncated-ip6 - %u bytes missing!",
 111                         len - length));
 112
 113         if (ndo->ndo_vflag) {
 114             flow = EXTRACT_32BITS(&ip6->ip6_flow);
 115             ND_PRINT((ndo, "("));
 116 #if 0
 117             /* rfc1883 */
 118             if (flow & 0x0f000000)
 119                 (void)ND_PRINT((ndo, "pri 0x%02x, ", (flow & 0x0f000000) >> 24));
 120             if (flow & 0x00ffffff)
 121                 (void)ND_PRINT((ndo, "flowlabel 0x%06x, ", flow & 0x00ffffff));
 122 #else
 123             /* RFC 2460 */
 124             if (flow & 0x0ff00000)
 125                 (void)ND_PRINT((ndo, "class 0x%02x, ", (flow & 0x0ff00000) >> 20));
 126             if (flow & 0x000fffff)
 127                 (void)ND_PRINT((ndo, "flowlabel 0x%05x, ", flow & 0x000fffff));
 128 #endif
 129
 130             (void)ND_PRINT((ndo, "hlim %u, next-header %s (%u) payload length: %u) ",
 131                          ip6->ip6_hlim,
 132                          tok2str(ipproto_values,"unknown",ip6->ip6_nxt),
 133                          ip6->ip6_nxt,
 134                          payload_len));
 135         }
 136
 137         /*
 138          * Cut off the snapshot length to the end of the IP payload.
 139          */
 140         ipend = bp + len;
 141         if (ipend < ndo->ndo_snapend)
 142                 ndo->ndo_snapend = ipend;
 143
 144         cp = (const u_char *)ip6;
 145         advance = sizeof(struct ip6_hdr);
 146         nh = ip6->ip6_nxt;
 147         while (cp < ndo->ndo_snapend && advance > 0) {
 148                 cp += advance;
 149                 len -= advance;
 150
 151                 if (cp == (const u_char *)(ip6 + 1) &&
 152                     nh != IPPROTO_TCP && nh != IPPROTO_UDP &&
 153                     nh != IPPROTO_DCCP && nh != IPPROTO_SCTP) {
 154                         (void)ND_PRINT((ndo, "%s > %s: ", ip6addr_string(&ip6->ip6_src),
 155                                      ip6addr_string(&ip6->ip6_dst)));
 156                 }
 157
 158                 switch (nh) {
 159                 case IPPROTO_HOPOPTS:
 160                         advance = hbhopt_print(cp);
 161                         nh = *cp;
 162                         break;
 163                 case IPPROTO_DSTOPTS:
 164                         advance = dstopt_print(cp);
 165                         nh = *cp;
 166                         break;
 167                 case IPPROTO_FRAGMENT:
 168                         advance = frag6_print(cp, (const u_char *)ip6);
 169                         if (ndo->ndo_snapend <= cp + advance)
 170                                 return;
 171                         nh = *cp;
 172                         fragmented = 1;
 173                         break;
 174
 175                 case IPPROTO_MOBILITY_OLD:
 176                 case IPPROTO_MOBILITY:
 177                         /*
 178                          * XXX - we don't use "advance"; the current
 179                          * "Mobility Support in IPv6" draft
 180                          * (draft-ietf-mobileip-ipv6-24) says that
 181                          * the next header field in a mobility header
 182                          * should be IPPROTO_NONE, but speaks of
 183                          * the possiblity of a future extension in
 184                          * which payload can be piggybacked atop a
 185                          * mobility header.
 186                          */
 187                         advance = mobility_print(cp, (const u_char *)ip6);
 188                         nh = *cp;
 189                         return;
 190                 case IPPROTO_ROUTING:
 191                         advance = rt6_print(cp, (const u_char *)ip6);
 192                         nh = *cp;
 193                         break;
 194                 case IPPROTO_SCTP:
 195                         sctp_print(cp, (const u_char *)ip6, len);
 196                         return;
 197                 case IPPROTO_DCCP:
 198                         dccp_print(cp, (const u_char *)ip6, len);
 199                         return;
 200                 case IPPROTO_TCP:
 201                         tcp_print(cp, len, (const u_char *)ip6, fragmented);
 202                         return;
 203                 case IPPROTO_UDP:
 204                         udp_print(cp, len, (const u_char *)ip6, fragmented);
 205                         return;
 206                 case IPPROTO_ICMPV6:
 207                         icmp6_print(ndo, cp, len, (const u_char *)ip6, fragmented);
 208                         return;
 209                 case IPPROTO_AH:
 210                         advance = ah_print(cp);
 211                         nh = *cp;
 212                         break;
 213                 case IPPROTO_ESP:
 214                     {
 215                         int enh, padlen;
 216                         advance = esp_print(ndo, cp, len, (const u_char *)ip6, &enh, &padlen);
 217                         nh = enh & 0xff;
 218                         len -= padlen;
 219                         break;
 220                     }
 221                 case IPPROTO_IPCOMP:
 222                     {
 223                         int enh;
 224                         advance = ipcomp_print(cp, &enh);
 225                         nh = enh & 0xff;
 226                         break;
 227                     }
 228
 229                 case IPPROTO_PIM:
 230                         pim_print(cp, len, nextproto6_cksum(ip6, cp, len,
 231                                                             IPPROTO_PIM));
 232                         return;
 233
 234                 case IPPROTO_OSPF:
 235                         ospf6_print(cp, len);
 236                         return;
 237
 238                 case IPPROTO_IPV6:
 239                         ip6_print(ndo, cp, len);
 240                         return;
 241
 242                 case IPPROTO_IPV4:
 243                         ip_print(ndo, cp, len);
 244                         return;
 245
 246                 case IPPROTO_PGM:
 247                         pgm_print(cp, len, (const u_char *)ip6);
 248                         return;
 249
 250                 case IPPROTO_GRE:
 251                         gre_print(cp, len);
 252                         return;
 253
 254                 case IPPROTO_RSVP:
 255                         rsvp_print(cp, len);
 256                         return;
 257
 258                 case IPPROTO_NONE:
 259                         (void)ND_PRINT((ndo, "no next header"));
 260                         return;
 261
 262                 default:
 263                         (void)ND_PRINT((ndo, "ip-proto-%d %d", nh, len));
 264                         return;
 265                 }
 266         }
 267
 268         return;
 269 trunc:
 270         (void)ND_PRINT((ndo, "[|ip6]"));
 271 }
 272
 273 #endif /* INET6 */