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 void
  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;
  83
  84 trunc:
  85     ND_PRINT("[trunc] ");
  86 }
  87
  88 static void
  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;
  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                 ip6_sopt_print(ndo, bp + i + IP6OPT_HOMEADDR_MINLEN,
 153                                (optlen - IP6OPT_HOMEADDR_MINLEN));
 154             }
 155             ND_PRINT(")");
 156             break;
 157         default:
 158             if (len - i < IP6OPT_MINLEN) {
 159                 ND_PRINT("(type %u: trunc)", EXTRACT_U_1(bp + i));
 160                 goto trunc;
 161             }
 162             ND_PRINT("(opt_type 0x%02x: len=%u)", EXTRACT_U_1(bp + i), EXTRACT_U_1(bp + i + 1));
 163             break;
 164         }
 165     }
 166     ND_PRINT(" ");
 167     return;
 168
 169 trunc:
 170     ND_PRINT("[trunc] ");
 171 }
 172
 173 int
 174 hbhopt_print(netdissect_options *ndo, const u_char *bp)
 175 {
 176     const struct ip6_hbh *dp = (const struct ip6_hbh *)bp;
 177     u_int hbhlen = 0;
 178
 179     ND_TCHECK_1(dp->ip6h_len);
 180     hbhlen = (EXTRACT_U_1(dp->ip6h_len) + 1) << 3;
 181     ND_TCHECK_LEN(dp, hbhlen);
 182     ND_PRINT("HBH ");
 183     if (ndo->ndo_vflag)
 184         ip6_opt_print(ndo, (const u_char *)dp + sizeof(*dp), hbhlen - sizeof(*dp));
 185
 186     return(hbhlen);
 187
 188   trunc:
 189     ND_PRINT("[|HBH]");
 190     return(-1);
 191 }
 192
 193 int
 194 dstopt_print(netdissect_options *ndo, const u_char *bp)
 195 {
 196     const struct ip6_dest *dp = (const struct ip6_dest *)bp;
 197     u_int dstoptlen = 0;
 198
 199     ND_TCHECK_1(dp->ip6d_len);
 200     dstoptlen = (EXTRACT_U_1(dp->ip6d_len) + 1) << 3;
 201     ND_TCHECK_LEN(dp, dstoptlen);
 202     ND_PRINT("DSTOPT ");
 203     if (ndo->ndo_vflag) {
 204         ip6_opt_print(ndo, (const u_char *)dp + sizeof(*dp),
 205             dstoptlen - sizeof(*dp));
 206     }
 207
 208     return(dstoptlen);
 209
 210   trunc:
 211     ND_PRINT("[|DSTOPT]");
 212     return(-1);
 213 }