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 "interface.h"
  40 #include "addrtoname.h"
  41 #include "extract.h"
  42
  43 #include "ip6.h"
  44 #include "ipproto.h"
  45
  46 /*
  47  * Compute a V6-style checksum by building a pseudoheader.
  48  */
  49 int
  50 nextproto6_cksum(const struct ip6_hdr *ip6, const u_short *data,
  51                  u_int len, u_int next_proto)
  52 {
  53         size_t i;
  54         u_int32_t sum = 0;
  55         union ip6_pseudo_hdr phu;
  56
  57         /* pseudo-header */
  58         memset(&phu, 0, sizeof(phu));
  59         phu.ph.ph_src = ip6->ip6_src;
  60         phu.ph.ph_dst = ip6->ip6_dst;
  61         phu.ph.ph_len = htonl(len);
  62         phu.ph.ph_nxt = next_proto;
  63
  64         for (i = 0; i < sizeof(phu.pa) / sizeof(phu.pa[0]); i++) {
  65                 sum += phu.pa[i];
  66         }
  67
  68         return in_cksum(data, len, sum);
  69 }
  70
  71 /*
  72  * print an IP6 datagram.
  73  */
  74 void
  75 ip6_print(register const u_char *bp, register 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         TCHECK(*ip6);
  90         if (length < sizeof (struct ip6_hdr)) {
  91                 (void)printf("truncated-ip6 %u", length);
  92                 return;
  93         }
  94
  95         if (!eflag)
  96             printf("IP6 ");
  97
  98         payload_len = EXTRACT_16BITS(&ip6->ip6_plen);
  99         len = payload_len + sizeof(struct ip6_hdr);
 100         if (length < len)
 101                 (void)printf("truncated-ip6 - %u bytes missing!",
 102                         len - length);
 103
 104         if (vflag) {
 105             flow = EXTRACT_32BITS(&ip6->ip6_flow);
 106             printf("(");
 107 #if 0
 108             /* rfc1883 */
 109             if (flow & 0x0f000000)
 110                 (void)printf("pri 0x%02x, ", (flow & 0x0f000000) >> 24);
 111             if (flow & 0x00ffffff)
 112                 (void)printf("flowlabel 0x%06x, ", flow & 0x00ffffff);
 113 #else
 114             /* RFC 2460 */
 115             if (flow & 0x0ff00000)
 116                 (void)printf("class 0x%02x, ", (flow & 0x0ff00000) >> 20);
 117             if (flow & 0x000fffff)
 118                 (void)printf("flowlabel 0x%05x, ", flow & 0x000fffff);
 119 #endif
 120
 121             (void)printf("hlim %u, next-header %s (%u) payload length: %u) ",
 122                          ip6->ip6_hlim,
 123                          tok2str(ipproto_values,"unknown",ip6->ip6_nxt),
 124                          ip6->ip6_nxt,
 125                          payload_len);
 126         }
 127
 128         /*
 129          * Cut off the snapshot length to the end of the IP payload.
 130          */
 131         ipend = bp + len;
 132         if (ipend < snapend)
 133                 snapend = ipend;
 134
 135         cp = (const u_char *)ip6;
 136         advance = sizeof(struct ip6_hdr);
 137         nh = ip6->ip6_nxt;
 138         while (cp < snapend && advance > 0) {
 139                 cp += advance;
 140                 len -= advance;
 141
 142                 if (cp == (const u_char *)(ip6 + 1) &&
 143                     nh != IPPROTO_TCP && nh != IPPROTO_UDP &&
 144                     nh != IPPROTO_DCCP && nh != IPPROTO_SCTP) {
 145                         (void)printf("%s > %s: ", ip6addr_string(&ip6->ip6_src),
 146                                      ip6addr_string(&ip6->ip6_dst));
 147                 }
 148
 149                 switch (nh) {
 150                 case IPPROTO_HOPOPTS:
 151                         advance = hbhopt_print(cp);
 152                         nh = *cp;
 153                         break;
 154                 case IPPROTO_DSTOPTS:
 155                         advance = dstopt_print(cp);
 156                         nh = *cp;
 157                         break;
 158                 case IPPROTO_FRAGMENT:
 159                         advance = frag6_print(cp, (const u_char *)ip6);
 160                         if (snapend <= cp + advance)
 161                                 return;
 162                         nh = *cp;
 163                         fragmented = 1;
 164                         break;
 165
 166                 case IPPROTO_MOBILITY_OLD:
 167                 case IPPROTO_MOBILITY:
 168                         /*
 169                          * XXX - we don't use "advance"; the current
 170                          * "Mobility Support in IPv6" draft
 171                          * (draft-ietf-mobileip-ipv6-24) says that
 172                          * the next header field in a mobility header
 173                          * should be IPPROTO_NONE, but speaks of
 174                          * the possiblity of a future extension in
 175                          * which payload can be piggybacked atop a
 176                          * mobility header.
 177                          */
 178                         advance = mobility_print(cp, (const u_char *)ip6);
 179                         nh = *cp;
 180                         return;
 181                 case IPPROTO_ROUTING:
 182                         advance = rt6_print(cp, (const u_char *)ip6);
 183                         nh = *cp;
 184                         break;
 185                 case IPPROTO_SCTP:
 186                         sctp_print(cp, (const u_char *)ip6, len);
 187                         return;
 188                 case IPPROTO_DCCP:
 189                         dccp_print(cp, (const u_char *)ip6, len);
 190                         return;
 191                 case IPPROTO_TCP:
 192                         tcp_print(cp, len, (const u_char *)ip6, fragmented);
 193                         return;
 194                 case IPPROTO_UDP:
 195                         udp_print(cp, len, (const u_char *)ip6, fragmented);
 196                         return;
 197                 case IPPROTO_ICMPV6:
 198                         icmp6_print(gndo, cp, len, (const u_char *)ip6, fragmented);
 199                         return;
 200                 case IPPROTO_AH:
 201                         advance = ah_print(cp);
 202                         nh = *cp;
 203                         break;
 204                 case IPPROTO_ESP:
 205                     {
 206                         int enh, padlen;
 207                         advance = esp_print(gndo, cp, len, (const u_char *)ip6, &enh, &padlen);
 208                         nh = enh & 0xff;
 209                         len -= padlen;
 210                         break;
 211                     }
 212                 case IPPROTO_IPCOMP:
 213                     {
 214                         int enh;
 215                         advance = ipcomp_print(cp, &enh);
 216                         nh = enh & 0xff;
 217                         break;
 218                     }
 219
 220                 case IPPROTO_PIM:
 221                         pim_print(cp, len, nextproto6_cksum(ip6, (u_short *)cp, len,
 222                                                             IPPROTO_PIM));
 223                         return;
 224
 225                 case IPPROTO_OSPF:
 226                         ospf6_print(cp, len);
 227                         return;
 228
 229                 case IPPROTO_IPV6:
 230                         ip6_print(cp, len);
 231                         return;
 232
 233                 case IPPROTO_IPV4:
 234                         ip_print(gndo, cp, len);
 235                         return;
 236
 237                 case IPPROTO_PGM:
 238                         pgm_print(cp, len, (const u_char *)ip6);
 239                         return;
 240
 241                 case IPPROTO_GRE:
 242                         gre_print(cp, len);
 243                         return;
 244
 245                 case IPPROTO_RSVP:
 246                         rsvp_print(cp, len);
 247                         return;
 248
 249                 case IPPROTO_NONE:
 250                         (void)printf("no next header");
 251                         return;
 252
 253                 default:
 254                         (void)printf("ip-proto-%d %d", nh, len);
 255                         return;
 256                 }
 257         }
 258
 259         return;
 260 trunc:
 261         (void)printf("[|ip6]");
 262 }
 263
 264 #endif /* INET6 */