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 #define NETDISSECT_REWORKED
  23 #ifdef HAVE_CONFIG_H
  24 #include "config.h"
  25 #endif
  26
  27 #include <tcpdump-stdinc.h>
  28
  29 #include <string.h>
  30
  31 #include "interface.h"
  32 #include "addrtoname.h"
  33 #include "extract.h"
  34
  35 #ifdef INET6
  36
  37 #include "ip6.h"
  38 #include "ipproto.h"
  39
  40 /*
  41  * Compute a V6-style checksum by building a pseudoheader.
  42  */
  43 int
  44 nextproto6_cksum(const struct ip6_hdr *ip6, const uint8_t *data,
  45                  u_int len, u_int covlen, u_int next_proto)
  46 {
  47         struct {
  48                 struct in6_addr ph_src;
  49                 struct in6_addr ph_dst;
  50                 uint32_t       ph_len;
  51                 uint8_t        ph_zero[3];
  52                 uint8_t        ph_nxt;
  53         } ph;
  54         struct cksum_vec vec[2];
  55
  56         /* pseudo-header */
  57         memset(&ph, 0, sizeof(ph));
  58         UNALIGNED_MEMCPY(&ph.ph_src, &ip6->ip6_src, sizeof (struct in6_addr));
  59         UNALIGNED_MEMCPY(&ph.ph_dst, &ip6->ip6_dst, sizeof (struct in6_addr));
  60         ph.ph_len = htonl(len);
  61         ph.ph_nxt = next_proto;
  62
  63         vec[0].ptr = (const uint8_t *)(void *)&ph;
  64         vec[0].len = sizeof(ph);
  65         vec[1].ptr = data;
  66         vec[1].len = covlen;
  67
  68         return in_cksum(vec, 2);
  69 }
  70
  71 /*
  72  * print an IP6 datagram.
  73  */
  74 void
  75 ip6_print(netdissect_options *ndo, const u_char *bp, u_int length)
  76 {
  77         register const struct ip6_hdr *ip6;
  78         register int advance;
  79         u_int len;
  80         const u_char *ipend;
  81         register const u_char *cp;
  82         register u_int payload_len;
  83         int nh;
  84         int fragmented = 0;
  85         u_int flow;
  86
  87         ip6 = (const struct ip6_hdr *)bp;
  88
  89         ND_TCHECK(*ip6);
  90         if (length < sizeof (struct ip6_hdr)) {
  91                 ND_PRINT((ndo, "truncated-ip6 %u", length));
  92                 return;
  93         }
  94
  95         if (!ndo->ndo_eflag)
  96             ND_PRINT((ndo, "IP6 "));
  97
  98         if (IP6_VERSION(ip6) != 6) {
  99           ND_PRINT((ndo,"version error: %u != 6", IP6_VERSION(ip6)));
 100           return;
 101         }
 102
 103         payload_len = EXTRACT_16BITS(&ip6->ip6_plen);
 104         len = payload_len + sizeof(struct ip6_hdr);
 105         if (length < len)
 106                 ND_PRINT((ndo, "truncated-ip6 - %u bytes missing!",
 107                         len - length));
 108
 109         if (ndo->ndo_vflag) {
 110             flow = EXTRACT_32BITS(&ip6->ip6_flow);
 111             ND_PRINT((ndo, "("));
 112 #if 0
 113             /* rfc1883 */
 114             if (flow & 0x0f000000)
 115                 ND_PRINT((ndo, "pri 0x%02x, ", (flow & 0x0f000000) >> 24));
 116             if (flow & 0x00ffffff)
 117                 ND_PRINT((ndo, "flowlabel 0x%06x, ", flow & 0x00ffffff));
 118 #else
 119             /* RFC 2460 */
 120             if (flow & 0x0ff00000)
 121                 ND_PRINT((ndo, "class 0x%02x, ", (flow & 0x0ff00000) >> 20));
 122             if (flow & 0x000fffff)
 123                 ND_PRINT((ndo, "flowlabel 0x%05x, ", flow & 0x000fffff));
 124 #endif
 125
 126             ND_PRINT((ndo, "hlim %u, next-header %s (%u) payload length: %u) ",
 127                          ip6->ip6_hlim,
 128                          tok2str(ipproto_values,"unknown",ip6->ip6_nxt),
 129                          ip6->ip6_nxt,
 130                          payload_len));
 131         }
 132
 133         /*
 134          * Cut off the snapshot length to the end of the IP payload.
 135          */
 136         ipend = bp + len;
 137         if (ipend < ndo->ndo_snapend)
 138                 ndo->ndo_snapend = ipend;
 139
 140         cp = (const u_char *)ip6;
 141         advance = sizeof(struct ip6_hdr);
 142         nh = ip6->ip6_nxt;
 143         while (cp < ndo->ndo_snapend && advance > 0) {
 144                 cp += advance;
 145                 len -= advance;
 146
 147                 if (cp == (const u_char *)(ip6 + 1) &&
 148                     nh != IPPROTO_TCP && nh != IPPROTO_UDP &&
 149                     nh != IPPROTO_DCCP && nh != IPPROTO_SCTP) {
 150                         ND_PRINT((ndo, "%s > %s: ", ip6addr_string(ndo, &ip6->ip6_src),
 151                                      ip6addr_string(ndo, &ip6->ip6_dst)));
 152                 }
 153
 154                 switch (nh) {
 155                 case IPPROTO_HOPOPTS:
 156                         advance = hbhopt_print(ndo, cp);
 157                         nh = *cp;
 158                         break;
 159                 case IPPROTO_DSTOPTS:
 160                         advance = dstopt_print(ndo, cp);
 161                         nh = *cp;
 162                         break;
 163                 case IPPROTO_FRAGMENT:
 164                         advance = frag6_print(ndo, cp, (const u_char *)ip6);
 165                         if (ndo->ndo_snapend <= cp + advance)
 166                                 return;
 167                         nh = *cp;
 168                         fragmented = 1;
 169                         break;
 170
 171                 case IPPROTO_MOBILITY_OLD:
 172                 case IPPROTO_MOBILITY:
 173                         /*
 174                          * XXX - we don't use "advance"; the current
 175                          * "Mobility Support in IPv6" draft
 176                          * (draft-ietf-mobileip-ipv6-24) says that
 177                          * the next header field in a mobility header
 178                          * should be IPPROTO_NONE, but speaks of
 179                          * the possiblity of a future extension in
 180                          * which payload can be piggybacked atop a
 181                          * mobility header.
 182                          */
 183                         advance = mobility_print(ndo, cp, (const u_char *)ip6);
 184                         nh = *cp;
 185                         return;
 186                 case IPPROTO_ROUTING:
 187                         advance = rt6_print(ndo, cp, (const u_char *)ip6);
 188                         nh = *cp;
 189                         break;
 190                 case IPPROTO_SCTP:
 191                         sctp_print(ndo, cp, (const u_char *)ip6, len);
 192                         return;
 193                 case IPPROTO_DCCP:
 194                         dccp_print(ndo, cp, (const u_char *)ip6, len);
 195                         return;
 196                 case IPPROTO_TCP:
 197                         tcp_print(ndo, cp, len, (const u_char *)ip6, fragmented);
 198                         return;
 199                 case IPPROTO_UDP:
 200                         udp_print(ndo, cp, len, (const u_char *)ip6, fragmented);
 201                         return;
 202                 case IPPROTO_ICMPV6:
 203                         icmp6_print(ndo, cp, len, (const u_char *)ip6, fragmented);
 204                         return;
 205                 case IPPROTO_AH:
 206                         advance = ah_print(ndo, cp);
 207                         nh = *cp;
 208                         break;
 209                 case IPPROTO_ESP:
 210                     {
 211                         int enh, padlen;
 212                         advance = esp_print(ndo, cp, len, (const u_char *)ip6, &enh, &padlen);
 213                         nh = enh & 0xff;
 214                         len -= padlen;
 215                         break;
 216                     }
 217                 case IPPROTO_IPCOMP:
 218                     {
 219                         int enh;
 220                         advance = ipcomp_print(ndo, cp, &enh);
 221                         nh = enh & 0xff;
 222                         break;
 223                     }
 224
 225                 case IPPROTO_PIM:
 226                         pim_print(ndo, cp, len, nextproto6_cksum(ip6, cp, len, len,
 227                                                             IPPROTO_PIM));
 228                         return;
 229
 230                 case IPPROTO_OSPF:
 231                         ospf6_print(ndo, cp, len);
 232                         return;
 233
 234                 case IPPROTO_IPV6:
 235                         ip6_print(ndo, cp, len);
 236                         return;
 237
 238                 case IPPROTO_IPV4:
 239                         ip_print(ndo, cp, len);
 240                         return;
 241
 242                 case IPPROTO_PGM:
 243                         pgm_print(ndo, cp, len, (const u_char *)ip6);
 244                         return;
 245
 246                 case IPPROTO_GRE:
 247                         gre_print(ndo, cp, len);
 248                         return;
 249
 250                 case IPPROTO_RSVP:
 251                         rsvp_print(ndo, cp, len);
 252                         return;
 253
 254                 case IPPROTO_NONE:
 255                         ND_PRINT((ndo, "no next header"));
 256                         return;
 257
 258                 default:
 259                         ND_PRINT((ndo, "ip-proto-%d %d", nh, len));
 260                         return;
 261                 }
 262         }
 263
 264         return;
 265 trunc:
 266         ND_PRINT((ndo, "[|ip6]"));
 267 }
 268
 269 #else /* INET6 */
 270
 271 void
 272 ip6_print(netdissect_options *ndo, const u_char *bp _U_, u_int length)
 273 {
 274         ND_PRINT((ndo, "IP6, length: %u (printing not supported)", length));
 275 }
 276
 277 #endif /* INET6 */