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_short *data,
  52                  u_int len, u_int next_proto)
  53 {
  54         size_t i;
  55         u_int32_t sum = 0;
  56         union ip6_pseudo_hdr phu;
  57
  58         /* pseudo-header */
  59         memset(&phu, 0, sizeof(phu));
  60         phu.ph.ph_src = ip6->ip6_src;
  61         phu.ph.ph_dst = ip6->ip6_dst;
  62         phu.ph.ph_len = htonl(len);
  63         phu.ph.ph_nxt = next_proto;
  64
  65         for (i = 0; i < sizeof(phu.pa) / sizeof(phu.pa[0]); i++) {
  66                 sum += phu.pa[i];
  67         }
  68
  69         return in_cksum(data, len, sum);
  70 }
  71
  72 /*
  73  * print an IP6 datagram.
  74  */
  75 void
  76 ip6_print(register const u_char *bp, register u_int length)
  77 {
  78         register const struct ip6_hdr *ip6;
  79         register int advance;
  80         u_int len;
  81         const u_char *ipend;
  82         register const u_char *cp;
  83         register u_int payload_len;
  84         int nh;
  85         int fragmented = 0;
  86         u_int flow;
  87
  88         ip6 = (const struct ip6_hdr *)bp;
  89
  90         TCHECK(*ip6);
  91         if (length < sizeof (struct ip6_hdr)) {
  92                 (void)printf("truncated-ip6 %u", length);
  93                 return;
  94         }
  95
  96         if (!eflag)
  97             printf("IP6 ");
  98
  99         payload_len = EXTRACT_16BITS(&ip6->ip6_plen);
 100         len = payload_len + sizeof(struct ip6_hdr);
 101         if (length < len)
 102                 (void)printf("truncated-ip6 - %u bytes missing!",
 103                         len - length);
 104
 105         if (vflag) {
 106             flow = EXTRACT_32BITS(&ip6->ip6_flow);
 107             printf("(");
 108 #if 0
 109             /* rfc1883 */
 110             if (flow & 0x0f000000)
 111                 (void)printf("pri 0x%02x, ", (flow & 0x0f000000) >> 24);
 112             if (flow & 0x00ffffff)
 113                 (void)printf("flowlabel 0x%06x, ", flow & 0x00ffffff);
 114 #else
 115             /* RFC 2460 */
 116             if (flow & 0x0ff00000)
 117                 (void)printf("class 0x%02x, ", (flow & 0x0ff00000) >> 20);
 118             if (flow & 0x000fffff)
 119                 (void)printf("flowlabel 0x%05x, ", flow & 0x000fffff);
 120 #endif
 121
 122             (void)printf("hlim %u, next-header %s (%u) payload length: %u) ",
 123                          ip6->ip6_hlim,
 124                          tok2str(ipproto_values,"unknown",ip6->ip6_nxt),
 125                          ip6->ip6_nxt,
 126                          payload_len);
 127         }
 128
 129         /*
 130          * Cut off the snapshot length to the end of the IP payload.
 131          */
 132         ipend = bp + len;
 133         if (ipend < snapend)
 134                 snapend = ipend;
 135
 136         cp = (const u_char *)ip6;
 137         advance = sizeof(struct ip6_hdr);
 138         nh = ip6->ip6_nxt;
 139         while (cp < snapend && advance > 0) {
 140                 cp += advance;
 141                 len -= advance;
 142
 143                 if (cp == (const u_char *)(ip6 + 1) &&
 144                     nh != IPPROTO_TCP && nh != IPPROTO_UDP &&
 145                     nh != IPPROTO_DCCP && nh != IPPROTO_SCTP) {
 146                         (void)printf("%s > %s: ", ip6addr_string(&ip6->ip6_src),
 147                                      ip6addr_string(&ip6->ip6_dst));
 148                 }
 149
 150                 switch (nh) {
 151                 case IPPROTO_HOPOPTS:
 152                         advance = hbhopt_print(cp);
 153                         nh = *cp;
 154                         break;
 155                 case IPPROTO_DSTOPTS:
 156                         advance = dstopt_print(cp);
 157                         nh = *cp;
 158                         break;
 159                 case IPPROTO_FRAGMENT:
 160                         advance = frag6_print(cp, (const u_char *)ip6);
 161                         if (snapend <= cp + advance)
 162                                 return;
 163                         nh = *cp;
 164                         fragmented = 1;
 165                         break;
 166
 167                 case IPPROTO_MOBILITY_OLD:
 168                 case IPPROTO_MOBILITY:
 169                         /*
 170                          * XXX - we don't use "advance"; the current
 171                          * "Mobility Support in IPv6" draft
 172                          * (draft-ietf-mobileip-ipv6-24) says that
 173                          * the next header field in a mobility header
 174                          * should be IPPROTO_NONE, but speaks of
 175                          * the possiblity of a future extension in
 176                          * which payload can be piggybacked atop a
 177                          * mobility header.
 178                          */
 179                         advance = mobility_print(cp, (const u_char *)ip6);
 180                         nh = *cp;
 181                         return;
 182                 case IPPROTO_ROUTING:
 183                         advance = rt6_print(cp, (const u_char *)ip6);
 184                         nh = *cp;
 185                         break;
 186                 case IPPROTO_SCTP:
 187                         sctp_print(cp, (const u_char *)ip6, len);
 188                         return;
 189                 case IPPROTO_DCCP:
 190                         dccp_print(cp, (const u_char *)ip6, len);
 191                         return;
 192                 case IPPROTO_TCP:
 193                         tcp_print(cp, len, (const u_char *)ip6, fragmented);
 194                         return;
 195                 case IPPROTO_UDP:
 196                         udp_print(cp, len, (const u_char *)ip6, fragmented);
 197                         return;
 198                 case IPPROTO_ICMPV6:
 199                         icmp6_print(gndo, cp, len, (const u_char *)ip6, fragmented);
 200                         return;
 201                 case IPPROTO_AH:
 202                         advance = ah_print(cp);
 203                         nh = *cp;
 204                         break;
 205                 case IPPROTO_ESP:
 206                     {
 207                         int enh, padlen;
 208                         advance = esp_print(gndo, cp, len, (const u_char *)ip6, &enh, &padlen);
 209                         nh = enh & 0xff;
 210                         len -= padlen;
 211                         break;
 212                     }
 213                 case IPPROTO_IPCOMP:
 214                     {
 215                         int enh;
 216                         advance = ipcomp_print(cp, &enh);
 217                         nh = enh & 0xff;
 218                         break;
 219                     }
 220
 221                 case IPPROTO_PIM:
 222                         pim_print(cp, len, nextproto6_cksum(ip6, (u_short *)cp, len,
 223                                                             IPPROTO_PIM));
 224                         return;
 225
 226                 case IPPROTO_OSPF:
 227                         ospf6_print(cp, len);
 228                         return;
 229
 230                 case IPPROTO_IPV6:
 231                         ip6_print(cp, len);
 232                         return;
 233
 234                 case IPPROTO_IPV4:
 235                         ip_print(gndo, cp, len);
 236                         return;
 237
 238                 case IPPROTO_PGM:
 239                         pgm_print(cp, len, (const u_char *)ip6);
 240                         return;
 241
 242                 case IPPROTO_GRE:
 243                         gre_print(cp, len);
 244                         return;
 245
 246                 case IPPROTO_RSVP:
 247                         rsvp_print(cp, len);
 248                         return;
 249
 250                 case IPPROTO_NONE:
 251                         (void)printf("no next header");
 252                         return;
 253
 254                 default:
 255                         (void)printf("ip-proto-%d %d", nh, len);
 256                         return;
 257                 }
 258         }
 259
 260         return;
 261 trunc:
 262         (void)printf("[|ip6]");
 263 }
 264
 265 #endif /* INET6 */