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 #include <sys/cdefs.h> 20 #ifndef lint 21 __RCSID("$NetBSD: print-msdp.c,v 1.7 2023/08/17 20:19:40 christos Exp $"); 22 #endif 23 24 /* \summary: Multicast Source Discovery Protocol (MSDP) printer */ 25 26 #ifdef HAVE_CONFIG_H 27 #include <config.h> 28 #endif 29 30 #include "netdissect-stdinc.h" 31 32 #include "netdissect.h" 33 #include "addrtoname.h" 34 #include "extract.h" 35 36 #define MSDP_TYPE_MAX 7 37 38 void 39 msdp_print(netdissect_options *ndo, const u_char *sp, u_int length) 40 { 41 unsigned int type, len; 42 43 ndo->ndo_protocol = "msdp"; 44 ND_PRINT(": "); 45 nd_print_protocol(ndo); 46 /* See if we think we're at the beginning of a compound packet */ 47 type = GET_U_1(sp); 48 len = GET_BE_U_2(sp + 1); 49 if (len > 1500 || len < 3 || type == 0 || type > MSDP_TYPE_MAX) 50 goto trunc; /* not really truncated, but still not decodable */ 51 while (length != 0) { 52 type = GET_U_1(sp); 53 len = GET_BE_U_2(sp + 1); 54 if (len > 1400 || ndo->ndo_vflag) 55 ND_PRINT(" [len %u]", len); 56 if (len < 3) 57 goto trunc; 58 if (length < len) 59 goto trunc; 60 sp += 3; 61 length -= 3; 62 switch (type) { 63 case 1: /* IPv4 Source-Active */ 64 case 3: /* IPv4 Source-Active Response */ 65 if (type == 1) 66 ND_PRINT(" SA"); 67 else 68 ND_PRINT(" SA-Response"); 69 ND_PRINT(" %u entries", GET_U_1(sp)); 70 if ((u_int)((GET_U_1(sp) * 12) + 8) < len) { 71 ND_PRINT(" [w/data]"); 72 if (ndo->ndo_vflag > 1) { 73 ND_PRINT(" "); 74 ip_print(ndo, sp + 75 GET_U_1(sp) * 12 + 8 - 3, 76 len - (GET_U_1(sp) * 12 + 8)); 77 } 78 } 79 break; 80 case 2: 81 ND_PRINT(" SA-Request"); 82 ND_PRINT(" for %s", GET_IPADDR_STRING(sp + 1)); 83 break; 84 case 4: 85 ND_PRINT(" Keepalive"); 86 if (len != 3) 87 ND_PRINT("[len=%u] ", len); 88 break; 89 case 5: 90 ND_PRINT(" Notification"); 91 break; 92 default: 93 ND_PRINT(" [type=%u len=%u]", type, len); 94 break; 95 } 96 sp += (len - 3); 97 length -= (len - 3); 98 } 99 return; 100 trunc: 101 nd_print_trunc(ndo); 102 } 103