The Tcpdump Group git mirrors - tcpdump/blob - print-rt6.c

   1 /*
   2  * Copyright (c) 1988, 1989, 1990, 1991, 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 /* \summary: IPv6 routing header printer */
  23
  24 #include <config.h>
  25
  26 #include "netdissect-stdinc.h"
  27
  28 #define ND_LONGJMP_FROM_TCHECK
  29 #include "netdissect.h"
  30 #include "addrtoname.h"
  31 #include "extract.h"
  32
  33 #include "ip6.h"
  34
  35 static const struct tok srh_tlv_type[] = {
  36     { IPV6_SRH_TLV_PAD1, "Pad1"},
  37     { IPV6_SRH_TLV_PADN, "PadN"},
  38     { IPV6_SRH_TLV_HMAC, "HMAC"},
  39     { 0, NULL }
  40 };
  41
  42 static int
  43 srh_tlv_print(netdissect_options *ndo, const u_char *p, u_int bytes_left)
  44 {
  45         u_int tlv_type, tlv_len;
  46         while (bytes_left != 0) {
  47                 tlv_type = GET_U_1(p);
  48                 ND_PRINT(", TLV-type=%s(%u)",
  49                          tok2str(srh_tlv_type, "Unknown", tlv_type),
  50                          tlv_type);
  51                 ND_ICHECKMSG_U("remaining length", bytes_left, <, 1);
  52                 p += 1;
  53                 bytes_left -= 1;
  54                 if (bytes_left == 0)
  55                         break;
  56                 if (tlv_type == IPV6_SRH_TLV_PAD1)
  57                         continue;
  58
  59                 tlv_len = GET_U_1(p);
  60                 ND_PRINT(", TLV-len=%u", tlv_len);
  61                 ND_ICHECKMSG_U("remaining length", bytes_left, <, 1);
  62                 p += 1;
  63                 bytes_left -= 1;
  64
  65                 switch (tlv_type) {
  66                 case IPV6_SRH_TLV_PADN:
  67                         ND_ICHECKMSG_U("PadN length", tlv_len, >, 5); /* RFC 8754 */
  68                         ND_ICHECKMSG_U("remaining length", bytes_left, <, tlv_len);
  69                         ND_TCHECK_LEN(p, tlv_len);
  70                         p += tlv_len;
  71                         bytes_left -= tlv_len;
  72                         break;
  73                 case IPV6_SRH_TLV_HMAC:
  74                         ND_ICHECKMSG_U("remaining length", bytes_left, <, 6);
  75                         uint16_t reserved;
  76                         uint32_t key_id;
  77                         uint8_t hmac_byte;
  78                         reserved = GET_BE_U_2(p);
  79                         p += 2;
  80                         if (ndo->ndo_vflag)
  81                                 ND_PRINT(", D=%u", reserved >> 15);
  82                         if (ndo->ndo_vflag && (reserved & 0x7fff) != 0)
  83                                 ND_PRINT(", reserved MBZ %u", reserved & 0x7fff);
  84                         key_id = GET_BE_U_4(p);
  85                         p += 4;
  86                         if (ndo->ndo_vflag)
  87                                 ND_PRINT(", HMAC-key-ID=0x%02x", key_id);
  88                         bytes_left -= 6;
  89                         if (ndo->ndo_vflag)
  90                                 ND_PRINT(", HMAC=0x");
  91                         for (u_int i = 0; i < tlv_len; i++) {
  92                                 hmac_byte = GET_U_1(p);
  93                                 ND_ICHECKMSG_U("remaining length", bytes_left, <, 1);
  94                                 p += 1;
  95                                 bytes_left -= 1;
  96                                 if (ndo->ndo_vflag)
  97                                         ND_PRINT("%02x", hmac_byte);
  98                         }
  99                         break;
 100                 default:        /* Unknown type */
 101                         if (ndo->ndo_vflag)
 102                                 ND_PRINT(", TLV-value=0x");
 103                         ND_ICHECKMSG_U("remaining length", bytes_left, <, tlv_len);
 104                         uint8_t tlv_byte;
 105                         for (u_int i = 0; i < tlv_len; i++) {
 106                                 tlv_byte = GET_U_1(p);
 107                                 p += 1;
 108                                 bytes_left -= 1;
 109                                 if (ndo->ndo_vflag)
 110                                         ND_PRINT("%02x", tlv_byte);
 111                         }
 112                         break;
 113                 }
 114         }
 115         return 0;
 116
 117 invalid:
 118         return -1;
 119 }
 120
 121
 122 int
 123 rt6_print(netdissect_options *ndo, const u_char *bp, const u_char *bp2 _U_)
 124 {
 125         const struct ip6_rthdr *dp;
 126         const struct ip6_rthdr0 *dp0;
 127         const struct ip6_srh *srh;
 128         u_int i, len, type, seg_list_len, last_entry;
 129         int err;
 130         const u_char *p;
 131
 132         ndo->ndo_protocol = "rt6";
 133
 134         nd_print_protocol_caps(ndo);
 135         dp = (const struct ip6_rthdr *)bp;
 136
 137         len = GET_U_1(dp->ip6r_len);
 138         ND_PRINT(" (len=%u", len);      /*)*/
 139         type = GET_U_1(dp->ip6r_type);
 140         ND_PRINT(", type=%u", type);
 141         if (type == IPV6_RTHDR_TYPE_0)
 142                 ND_PRINT(" [Deprecated]");
 143         ND_PRINT(", segleft=%u", GET_U_1(dp->ip6r_segleft));
 144
 145         switch (type) {
 146         case IPV6_RTHDR_TYPE_0:
 147         case IPV6_RTHDR_TYPE_2:                 /* Mobile IPv6 ID-20 */
 148                 dp0 = (const struct ip6_rthdr0 *)dp;
 149
 150                 if (GET_BE_U_4(dp0->ip6r0_reserved) || ndo->ndo_vflag) {
 151                         ND_PRINT(", rsv=0x%0x",
 152                             GET_BE_U_4(dp0->ip6r0_reserved));
 153                 }
 154
 155                 if (len % 2 == 1) {
 156                         ND_PRINT(" [length %u]", len);
 157                         goto invalid;
 158                 }
 159                 len >>= 1;
 160                 p = (const u_char *) dp0->ip6r0_addr;
 161                 for (i = 0; i < len; i++) {
 162                         ND_PRINT(", [%u]%s", i, GET_IP6ADDR_STRING(p));
 163                         p += 16;
 164                 }
 165                 /*(*/
 166                 ND_PRINT(") ");
 167                 return((GET_U_1(dp0->ip6r0_len) + 1) << 3);
 168         case IPV6_RTHDR_TYPE_4:
 169                 srh = (const struct ip6_srh *)dp;
 170                 last_entry = GET_U_1(srh->srh_last_ent);
 171                 ND_PRINT(", last-entry=%u", last_entry);
 172
 173                 if (GET_U_1(srh->srh_flags) || ndo->ndo_vflag) {
 174                         ND_PRINT(", flags=0x%0x",
 175                                 GET_U_1(srh->srh_flags));
 176                 }
 177
 178                 ND_PRINT(", tag=%x", GET_BE_U_2(srh->srh_tag));
 179                 p  = (const u_char *) srh->srh_segments;
 180                 for (i = 0; i < last_entry + 1; i++) {
 181                         ND_PRINT(", [%u]%s", i, GET_IP6ADDR_STRING(p));
 182                         p += 16;
 183                 }
 184                 seg_list_len = (last_entry + 1) * 2;
 185                 if (seg_list_len < len) {
 186                         /* there is TLV */
 187                         u_int bytes_left;
 188                         bytes_left = (len - seg_list_len) * 8;
 189                         err = srh_tlv_print(ndo, p, bytes_left);
 190                         if (err)
 191                                 goto invalid;
 192                 }
 193
 194                 /*(*/
 195                 ND_PRINT(") ");
 196                 return((GET_U_1(srh->srh_len) + 1) << 3);
 197         default:
 198                 ND_PRINT(" (unknown type)");
 199                 goto invalid;
 200         }
 201
 202 invalid:
 203         nd_print_invalid(ndo);
 204         return -1;
 205 }