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