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

   1 /*
   2  * Copyright (C) 2001 Julian Cowley
   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: Cisco Hot Standby Router Protocol (HSRP) printer */
  31
  32 /* specification: RFC 2281 for version 1 */
  33
  34 #include <config.h>
  35
  36 #include "netdissect-stdinc.h"
  37
  38 #include "netdissect.h"
  39 #include "addrtoname.h"
  40 #include "extract.h"
  41
  42 /* HSRP op code types. */
  43 static const char *op_code_str[] = {
  44         "hello",
  45         "coup",
  46         "resign"
  47 };
  48
  49 /* HSRP states and associated names. */
  50 static const struct tok states[] = {
  51         {  0, "initial" },
  52         {  1, "learn" },
  53         {  2, "listen" },
  54         {  4, "speak" },
  55         {  8, "standby" },
  56         { 16, "active" },
  57         {  0, NULL }
  58 };
  59
  60 /*
  61  * RFC 2281:
  62  *
  63  *  0                   1                   2                   3
  64  *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
  65  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  66  * |   Version     |   Op Code     |     State     |   Hellotime   |
  67  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  68  * |   Holdtime    |   Priority    |     Group     |   Reserved    |
  69  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  70  * |                      Authentication  Data                     |
  71  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  72  * |                      Authentication  Data                     |
  73  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  74  * |                      Virtual IP Address                       |
  75  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  76  */
  77
  78 #define HSRP_AUTH_SIZE  8
  79
  80 /* HSRP protocol header. */
  81 struct hsrp {
  82         nd_uint8_t      hsrp_version;
  83         nd_uint8_t      hsrp_op_code;
  84         nd_uint8_t      hsrp_state;
  85         nd_uint8_t      hsrp_hellotime;
  86         nd_uint8_t      hsrp_holdtime;
  87         nd_uint8_t      hsrp_priority;
  88         nd_uint8_t      hsrp_group;
  89         nd_uint8_t      hsrp_reserved;
  90         nd_byte         hsrp_authdata[HSRP_AUTH_SIZE];
  91         nd_ipv4         hsrp_virtaddr;
  92 };
  93
  94 void
  95 hsrp_print(netdissect_options *ndo, const u_char *bp, u_int len)
  96 {
  97         const struct hsrp *hp = (const struct hsrp *) bp;
  98         uint8_t version;
  99
 100         ndo->ndo_protocol = "hsrp";
 101         version = GET_U_1(hp->hsrp_version);
 102         ND_PRINT("HSRPv%u", version);
 103         if (version != 0)
 104                 return;
 105         ND_PRINT("-");
 106         ND_PRINT("%s ",
 107                  tok2strary(op_code_str, "unknown (%u)", GET_U_1(hp->hsrp_op_code)));
 108         ND_PRINT("%u: ", len);
 109         ND_PRINT("state=%s ",
 110                  tok2str(states, "Unknown (%u)", GET_U_1(hp->hsrp_state)));
 111         ND_PRINT("group=%u ", GET_U_1(hp->hsrp_group));
 112         if (GET_U_1(hp->hsrp_reserved) != 0) {
 113                 ND_PRINT("[reserved=%u!] ", GET_U_1(hp->hsrp_reserved));
 114         }
 115         ND_PRINT("addr=%s", GET_IPADDR_STRING(hp->hsrp_virtaddr));
 116         if (ndo->ndo_vflag) {
 117                 ND_PRINT(" hellotime=");
 118                 unsigned_relts_print(ndo, GET_U_1(hp->hsrp_hellotime));
 119                 ND_PRINT(" holdtime=");
 120                 unsigned_relts_print(ndo, GET_U_1(hp->hsrp_holdtime));
 121                 ND_PRINT(" priority=%u", GET_U_1(hp->hsrp_priority));
 122                 ND_PRINT(" auth=\"");
 123                 /*
 124                  * RFC 2281 Section 5.1 does not specify the encoding of
 125                  * Authentication Data explicitly, but zero padding can be
 126                  * inferred from the "recommended default value".
 127                  */
 128                 nd_printjnp(ndo, hp->hsrp_authdata, HSRP_AUTH_SIZE);
 129                 ND_PRINT("\"");
 130         }
 131 }