The Tcpdump Group git mirrors - tcpdump/blob - print-ip6opts.c

   1 /*
   2  * Copyright (C) 1998 WIDE Project.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the project nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 /* \summary: IPv6 header option printer */
  31
  32 #ifdef HAVE_CONFIG_H
  33 #include <config.h>
  34 #endif
  35
  36 #include "netdissect-stdinc.h"
  37
  38 #include "netdissect.h"
  39 #include "addrtoname.h"
  40 #include "extract.h"
  41
  42 #include "ip6.h"
  43
  44 static int
  45 ip6_sopt_print(netdissect_options *ndo, const u_char *bp, int len)
  46 {
  47     int i;
  48     int optlen;
  49
  50     for (i = 0; i < len; i += optlen) {
  51         if (EXTRACT_U_1(bp + i) == IP6OPT_PAD1)
  52             optlen = 1;
  53         else {
  54             if (i + 1 < len)
  55                 optlen = EXTRACT_U_1(bp + i + 1) + 2;
  56             else
  57                 goto trunc;
  58         }
  59         if (i + optlen > len)
  60             goto trunc;
  61
  62         switch (EXTRACT_U_1(bp + i)) {
  63         case IP6OPT_PAD1:
  64             ND_PRINT(", pad1");
  65             break;
  66         case IP6OPT_PADN:
  67             if (len - i < IP6OPT_MINLEN) {
  68                 ND_PRINT(", padn: trunc");
  69                 goto trunc;
  70             }
  71             ND_PRINT(", padn");
  72             break;
  73         default:
  74             if (len - i < IP6OPT_MINLEN) {
  75                 ND_PRINT(", sopt_type %u: trunc)", EXTRACT_U_1(bp + i));
  76                 goto trunc;
  77             }
  78             ND_PRINT(", sopt_type 0x%02x: len=%u", EXTRACT_U_1(bp + i), EXTRACT_U_1(bp + i + 1));
  79             break;
  80         }
  81     }
  82     return 0;
  83
  84 trunc:
  85     return -1;
  86 }
  87
  88 static int
  89 ip6_opt_print(netdissect_options *ndo, const u_char *bp, int len)
  90 {
  91     int i;
  92     int optlen = 0;
  93
  94     if (len == 0)
  95         return 0;
  96     for (i = 0; i < len; i += optlen) {
  97         if (EXTRACT_U_1(bp + i) == IP6OPT_PAD1)
  98             optlen = 1;
  99         else {
 100             if (i + 1 < len)
 101                 optlen = EXTRACT_U_1(bp + i + 1) + 2;
 102             else
 103                 goto trunc;
 104         }
 105         if (i + optlen > len)
 106             goto trunc;
 107
 108         switch (EXTRACT_U_1(bp + i)) {
 109         case IP6OPT_PAD1:
 110             ND_PRINT("(pad1)");
 111             break;
 112         case IP6OPT_PADN:
 113             if (len - i < IP6OPT_MINLEN) {
 114                 ND_PRINT("(padn: trunc)");
 115                 goto trunc;
 116             }
 117             ND_PRINT("(padn)");
 118             break;
 119         case IP6OPT_ROUTER_ALERT:
 120             if (len - i < IP6OPT_RTALERT_LEN) {
 121                 ND_PRINT("(rtalert: trunc)");
 122                 goto trunc;
 123             }
 124             if (EXTRACT_U_1(bp + i + 1) != IP6OPT_RTALERT_LEN - 2) {
 125                 ND_PRINT("(rtalert: invalid len %u)", EXTRACT_U_1(bp + i + 1));
 126                 goto trunc;
 127             }
 128             ND_PRINT("(rtalert: 0x%04x) ", EXTRACT_BE_U_2(bp + i + 2));
 129             break;
 130         case IP6OPT_JUMBO:
 131             if (len - i < IP6OPT_JUMBO_LEN) {
 132                 ND_PRINT("(jumbo: trunc)");
 133                 goto trunc;
 134             }
 135             if (EXTRACT_U_1(bp + i + 1) != IP6OPT_JUMBO_LEN - 2) {
 136                 ND_PRINT("(jumbo: invalid len %u)", EXTRACT_U_1(bp + i + 1));
 137                 goto trunc;
 138             }
 139             ND_PRINT("(jumbo: %u) ", EXTRACT_BE_U_4(bp + i + 2));
 140             break;
 141         case IP6OPT_HOME_ADDRESS:
 142             if (len - i < IP6OPT_HOMEADDR_MINLEN) {
 143                 ND_PRINT("(homeaddr: trunc)");
 144                 goto trunc;
 145             }
 146             if (EXTRACT_U_1(bp + i + 1) < IP6OPT_HOMEADDR_MINLEN - 2) {
 147                 ND_PRINT("(homeaddr: invalid len %u)", EXTRACT_U_1(bp + i + 1));
 148                 goto trunc;
 149             }
 150             ND_PRINT("(homeaddr: %s", ip6addr_string(ndo, bp + i + 2));
 151             if (EXTRACT_U_1(bp + i + 1) > IP6OPT_HOMEADDR_MINLEN - 2) {
 152                 if (ip6_sopt_print(ndo, bp + i + IP6OPT_HOMEADDR_MINLEN,
 153                                    (optlen - IP6OPT_HOMEADDR_MINLEN)) == -1)
 154                         goto trunc;
 155             }
 156             ND_PRINT(")");
 157             break;
 158         default:
 159             if (len - i < IP6OPT_MINLEN) {
 160                 ND_PRINT("(type %u: trunc)", EXTRACT_U_1(bp + i));
 161                 goto trunc;
 162             }
 163             ND_PRINT("(opt_type 0x%02x: len=%u)", EXTRACT_U_1(bp + i), EXTRACT_U_1(bp + i + 1));
 164             break;
 165         }
 166     }
 167     ND_PRINT(" ");
 168     return 0;
 169
 170 trunc:
 171     return -1;
 172 }
 173
 174 int
 175 hbhopt_print(netdissect_options *ndo, const u_char *bp)
 176 {
 177     const struct ip6_hbh *dp = (const struct ip6_hbh *)bp;
 178     u_int hbhlen = 0;
 179
 180     ndo->ndo_protocol = "hbhopt";
 181     ND_TCHECK_1(dp->ip6h_len);
 182     hbhlen = (EXTRACT_U_1(dp->ip6h_len) + 1) << 3;
 183     ND_TCHECK_LEN(dp, hbhlen);
 184     ND_PRINT("HBH ");
 185     if (ndo->ndo_vflag)
 186         if (ip6_opt_print(ndo, (const u_char *)dp + sizeof(*dp),
 187                           hbhlen - sizeof(*dp)) == -1)
 188             goto trunc;
 189     return hbhlen;
 190
 191 trunc:
 192     nd_print_trunc(ndo);
 193     return -1;
 194 }
 195
 196 int
 197 dstopt_print(netdissect_options *ndo, const u_char *bp)
 198 {
 199     const struct ip6_dest *dp = (const struct ip6_dest *)bp;
 200     u_int dstoptlen = 0;
 201
 202     ndo->ndo_protocol = "dstopt";
 203     ND_TCHECK_1(dp->ip6d_len);
 204     dstoptlen = (EXTRACT_U_1(dp->ip6d_len) + 1) << 3;
 205     ND_TCHECK_LEN(dp, dstoptlen);
 206     ND_PRINT("DSTOPT ");
 207     if (ndo->ndo_vflag) {
 208         if (ip6_opt_print(ndo, (const u_char *)dp + sizeof(*dp),
 209                           dstoptlen - sizeof(*dp)) == -1)
 210             goto trunc;
 211     }
 212
 213     return dstoptlen;
 214
 215 trunc:
 216     nd_print_trunc(ndo);
 217     return -1;
 218 }