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