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 (GET_U_1(bp + i) == IP6OPT_PAD1)
  52             optlen = 1;
  53         else {
  54             if (i + 1 < len)
  55                 optlen = GET_U_1(bp + i + 1) + 2;
  56             else
  57                 goto trunc;
  58         }
  59         if (i + optlen > len)
  60             goto trunc;
  61
  62         switch (GET_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)", GET_U_1(bp + i));
  76                 goto trunc;
  77             }
  78             ND_PRINT(", sopt_type 0x%02x: len=%u", GET_U_1(bp + i),
  79                      GET_U_1(bp + i + 1));
  80             break;
  81         }
  82     }
  83     return 0;
  84
  85 trunc:
  86     return -1;
  87 }
  88
  89 static int
  90 ip6_opt_print(netdissect_options *ndo, const u_char *bp, int len)
  91 {
  92     int i;
  93     int optlen = 0;
  94
  95     if (len == 0)
  96         return 0;
  97     for (i = 0; i < len; i += optlen) {
  98         if (GET_U_1(bp + i) == IP6OPT_PAD1)
  99             optlen = 1;
 100         else {
 101             if (i + 1 < len)
 102                 optlen = GET_U_1(bp + i + 1) + 2;
 103             else
 104                 goto trunc;
 105         }
 106         if (i + optlen > len)
 107             goto trunc;
 108
 109         switch (GET_U_1(bp + i)) {
 110         case IP6OPT_PAD1:
 111             ND_PRINT("(pad1)");
 112             break;
 113         case IP6OPT_PADN:
 114             if (len - i < IP6OPT_MINLEN) {
 115                 ND_PRINT("(padn: trunc)");
 116                 goto trunc;
 117             }
 118             ND_PRINT("(padn)");
 119             break;
 120         case IP6OPT_ROUTER_ALERT:
 121             if (len - i < IP6OPT_RTALERT_LEN) {
 122                 ND_PRINT("(rtalert: trunc)");
 123                 goto trunc;
 124             }
 125             if (GET_U_1(bp + i + 1) != IP6OPT_RTALERT_LEN - 2) {
 126                 ND_PRINT("(rtalert: invalid len %u)", GET_U_1(bp + i + 1));
 127                 goto trunc;
 128             }
 129             ND_PRINT("(rtalert: 0x%04x) ", GET_BE_U_2(bp + i + 2));
 130             break;
 131         case IP6OPT_JUMBO:
 132             if (len - i < IP6OPT_JUMBO_LEN) {
 133                 ND_PRINT("(jumbo: trunc)");
 134                 goto trunc;
 135             }
 136             if (GET_U_1(bp + i + 1) != IP6OPT_JUMBO_LEN - 2) {
 137                 ND_PRINT("(jumbo: invalid len %u)", GET_U_1(bp + i + 1));
 138                 goto trunc;
 139             }
 140             ND_PRINT("(jumbo: %u) ", GET_BE_U_4(bp + i + 2));
 141             break;
 142         case IP6OPT_HOME_ADDRESS:
 143             if (len - i < IP6OPT_HOMEADDR_MINLEN) {
 144                 ND_PRINT("(homeaddr: trunc)");
 145                 goto trunc;
 146             }
 147             if (GET_U_1(bp + i + 1) < IP6OPT_HOMEADDR_MINLEN - 2) {
 148                 ND_PRINT("(homeaddr: invalid len %u)", GET_U_1(bp + i + 1));
 149                 goto trunc;
 150             }
 151             ND_PRINT("(homeaddr: %s", ip6addr_string(ndo, bp + i + 2));
 152             if (GET_U_1(bp + i + 1) > IP6OPT_HOMEADDR_MINLEN - 2) {
 153                 if (ip6_sopt_print(ndo, bp + i + IP6OPT_HOMEADDR_MINLEN,
 154                                    (optlen - IP6OPT_HOMEADDR_MINLEN)) == -1)
 155                         goto trunc;
 156             }
 157             ND_PRINT(")");
 158             break;
 159         default:
 160             if (len - i < IP6OPT_MINLEN) {
 161                 ND_PRINT("(type %u: trunc)", GET_U_1(bp + i));
 162                 goto trunc;
 163             }
 164             ND_PRINT("(opt_type 0x%02x: len=%u)", GET_U_1(bp + i),
 165                      GET_U_1(bp + i + 1));
 166             break;
 167         }
 168     }
 169     ND_PRINT(" ");
 170     return 0;
 171
 172 trunc:
 173     return -1;
 174 }
 175
 176 int
 177 hbhopt_print(netdissect_options *ndo, const u_char *bp)
 178 {
 179     const struct ip6_hbh *dp = (const struct ip6_hbh *)bp;
 180     u_int hbhlen = 0;
 181
 182     ndo->ndo_protocol = "hbhopt";
 183     ND_TCHECK_1(dp->ip6h_len);
 184     hbhlen = (GET_U_1(dp->ip6h_len) + 1) << 3;
 185     ND_TCHECK_LEN(dp, hbhlen);
 186     ND_PRINT("HBH ");
 187     if (ndo->ndo_vflag)
 188         if (ip6_opt_print(ndo, (const u_char *)dp + sizeof(*dp),
 189                           hbhlen - sizeof(*dp)) == -1)
 190             goto trunc;
 191     return hbhlen;
 192
 193 trunc:
 194     nd_print_trunc(ndo);
 195     return -1;
 196 }
 197
 198 int
 199 dstopt_print(netdissect_options *ndo, const u_char *bp)
 200 {
 201     const struct ip6_dest *dp = (const struct ip6_dest *)bp;
 202     u_int dstoptlen = 0;
 203
 204     ndo->ndo_protocol = "dstopt";
 205     ND_TCHECK_1(dp->ip6d_len);
 206     dstoptlen = (GET_U_1(dp->ip6d_len) + 1) << 3;
 207     ND_TCHECK_LEN(dp, dstoptlen);
 208     ND_PRINT("DSTOPT ");
 209     if (ndo->ndo_vflag) {
 210         if (ip6_opt_print(ndo, (const u_char *)dp + sizeof(*dp),
 211                           dstoptlen - sizeof(*dp)) == -1)
 212             goto trunc;
 213     }
 214
 215     return dstoptlen;
 216
 217 trunc:
 218     nd_print_trunc(ndo);
 219     return -1;
 220 }