1 /* 2 * Copyright (c) 2001 William C. Fenner. 3 * 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 7 * distributions retain the above copyright notice and this paragraph 8 * in its entirety, and (2) distributions including binary code include 9 * the above copyright notice and this paragraph in its entirety in 10 * the documentation or other materials provided with the distribution. 11 * The name of William C. Fenner may not be used to endorse or 12 * promote products derived from this software without specific prior 13 * written permission. THIS SOFTWARE IS PROVIDED ``AS IS'' AND 14 * WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT 15 * LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 16 * FOR A PARTICULAR PURPOSE. 17 */ 18 19 /* \summary: Multicast Source Discovery Protocol (MSDP) printer */ 20 21 #ifdef HAVE_CONFIG_H 22 #include <config.h> 23 #endif 24 25 #include "netdissect-stdinc.h" 26 27 #include "netdissect.h" 28 #include "addrtoname.h" 29 #include "extract.h" 30 31 #define MSDP_TYPE_MAX 7 32 33 void 34 msdp_print(netdissect_options *ndo, const u_char *sp, u_int length) 35 { 36 unsigned int type, len; 37 38 ndo->ndo_protocol = "msdp"; 39 ND_PRINT(": "); 40 nd_print_protocol(ndo); 41 /* See if we think we're at the beginning of a compound packet */ 42 type = GET_U_1(sp); 43 len = GET_BE_U_2(sp + 1); 44 if (len > 1500 || len < 3 || type == 0 || type > MSDP_TYPE_MAX) 45 goto trunc; /* not really truncated, but still not decodable */ 46 while (length != 0) { 47 type = GET_U_1(sp); 48 len = GET_BE_U_2(sp + 1); 49 if (len > 1400 || ndo->ndo_vflag) 50 ND_PRINT(" [len %u]", len); 51 if (len < 3) 52 goto trunc; 53 if (length < len) 54 goto trunc; 55 sp += 3; 56 length -= 3; 57 switch (type) { 58 case 1: /* IPv4 Source-Active */ 59 case 3: /* IPv4 Source-Active Response */ 60 if (type == 1) 61 ND_PRINT(" SA"); 62 else 63 ND_PRINT(" SA-Response"); 64 ND_PRINT(" %u entries", GET_U_1(sp)); 65 if ((u_int)((GET_U_1(sp) * 12) + 8) < len) { 66 ND_PRINT(" [w/data]"); 67 if (ndo->ndo_vflag > 1) { 68 ND_PRINT(" "); 69 ip_print(ndo, sp + 70 GET_U_1(sp) * 12 + 8 - 3, 71 len - (GET_U_1(sp) * 12 + 8)); 72 } 73 } 74 break; 75 case 2: 76 ND_PRINT(" SA-Request"); 77 ND_PRINT(" for %s", GET_IPADDR_STRING(sp + 1)); 78 break; 79 case 4: 80 ND_PRINT(" Keepalive"); 81 if (len != 3) 82 ND_PRINT("[len=%u] ", len); 83 break; 84 case 5: 85 ND_PRINT(" Notification"); 86 break; 87 default: 88 ND_PRINT(" [type=%u len=%u]", type, len); 89 break; 90 } 91 sp += (len - 3); 92 length -= (len - 3); 93 } 94 return; 95 trunc: 96 nd_print_trunc(ndo); 97 } 98