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 #ifdef HAVE_CONFIG_H 35 #include <config.h> 36 #endif 37 38 #include "netdissect-stdinc.h" 39 40 #include "netdissect.h" 41 #include "addrtoname.h" 42 #include "extract.h" 43 44 /* HSRP op code types. */ 45 static const char *op_code_str[] = { 46 "hello", 47 "coup", 48 "resign" 49 }; 50 51 /* HSRP states and associated names. */ 52 static const struct tok states[] = { 53 { 0, "initial" }, 54 { 1, "learn" }, 55 { 2, "listen" }, 56 { 4, "speak" }, 57 { 8, "standby" }, 58 { 16, "active" }, 59 { 0, NULL } 60 }; 61 62 /* 63 * RFC 2281: 64 * 65 * 0 1 2 3 66 * 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 67 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 68 * | Version | Op Code | State | Hellotime | 69 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 70 * | Holdtime | Priority | Group | Reserved | 71 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 72 * | Authentication Data | 73 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 74 * | Authentication Data | 75 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 76 * | Virtual IP Address | 77 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 78 */ 79 80 #define HSRP_AUTH_SIZE 8 81 82 /* HSRP protocol header. */ 83 struct hsrp { 84 nd_uint8_t hsrp_version; 85 nd_uint8_t hsrp_op_code; 86 nd_uint8_t hsrp_state; 87 nd_uint8_t hsrp_hellotime; 88 nd_uint8_t hsrp_holdtime; 89 nd_uint8_t hsrp_priority; 90 nd_uint8_t hsrp_group; 91 nd_uint8_t hsrp_reserved; 92 nd_byte hsrp_authdata[HSRP_AUTH_SIZE]; 93 nd_ipv4 hsrp_virtaddr; 94 }; 95 96 void 97 hsrp_print(netdissect_options *ndo, const u_char *bp, u_int len) 98 { 99 const struct hsrp *hp = (const struct hsrp *) bp; 100 uint8_t version; 101 102 ndo->ndo_protocol = "hsrp"; 103 version = GET_U_1(hp->hsrp_version); 104 ND_PRINT("HSRPv%u", version); 105 if (version != 0) 106 return; 107 ND_PRINT("-"); 108 ND_PRINT("%s ", 109 tok2strary(op_code_str, "unknown (%u)", GET_U_1(hp->hsrp_op_code))); 110 ND_PRINT("%u: ", len); 111 ND_PRINT("state=%s ", 112 tok2str(states, "Unknown (%u)", GET_U_1(hp->hsrp_state))); 113 ND_PRINT("group=%u ", GET_U_1(hp->hsrp_group)); 114 if (GET_U_1(hp->hsrp_reserved) != 0) { 115 ND_PRINT("[reserved=%u!] ", GET_U_1(hp->hsrp_reserved)); 116 } 117 ND_PRINT("addr=%s", GET_IPADDR_STRING(hp->hsrp_virtaddr)); 118 if (ndo->ndo_vflag) { 119 ND_PRINT(" hellotime="); 120 unsigned_relts_print(ndo, GET_U_1(hp->hsrp_hellotime)); 121 ND_PRINT(" holdtime="); 122 unsigned_relts_print(ndo, GET_U_1(hp->hsrp_holdtime)); 123 ND_PRINT(" priority=%u", GET_U_1(hp->hsrp_priority)); 124 ND_PRINT(" auth=\""); 125 /* 126 * RFC 2281 Section 5.1 does not specify the encoding of 127 * Authentication Data explicitly, but zero padding can be 128 * inferred from the "recommended default value". 129 */ 130 nd_printjnp(ndo, hp->hsrp_authdata, HSRP_AUTH_SIZE); 131 ND_PRINT("\""); 132 } 133 } 134