1 /* $OpenBSD: print-carp.c,v 1.6 2009/10/27 23:59:55 deraadt Exp $ */ 2 3 /* 4 * Copyright (c) 2000 William C. Fenner. 5 * All rights reserved. 6 * 7 * Kevin Steves <ks@hp.se> July 2000 8 * Modified to: 9 * - print version, type string and packet length 10 * - print IP address count if > 1 (-v) 11 * - verify checksum (-v) 12 * - print authentication string (-v) 13 * 14 * Copyright (c) 2011 Advanced Computing Technologies 15 * George V. Neille-Neil 16 * 17 * Modified to: 18 * - work correctly with CARP 19 * - compile into the latest tcpdump 20 * - print out the counter 21 * 22 * Redistribution and use in source and binary forms, with or without 23 * modification, are permitted provided that: (1) source code 24 * distributions retain the above copyright notice and this paragraph 25 * in its entirety, and (2) distributions including binary code include 26 * the above copyright notice and this paragraph in its entirety in 27 * the documentation or other materials provided with the distribution. 28 * The name of William C. Fenner may not be used to endorse or 29 * promote products derived from this software without specific prior 30 * written permission. THIS SOFTWARE IS PROVIDED ``AS IS'' AND 31 * WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT 32 * LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 33 * FOR A PARTICULAR PURPOSE. 34 * 35 */ 36 37 #ifdef HAVE_CONFIG_H 38 #include "config.h" 39 #endif 40 41 #include <tcpdump-stdinc.h> 42 43 #include <stdio.h> 44 #include <stdlib.h> 45 #include <unistd.h> 46 47 #include <netinet/in.h> 48 49 #include "interface.h" 50 #include "extract.h" 51 #include "addrtoname.h" 52 53 void 54 carp_print(register const u_char *bp, register u_int len, int ttl) 55 { 56 int version, type; 57 const char *type_s; 58 59 TCHECK(bp[0]); 60 version = (bp[0] & 0xf0) >> 4; 61 type = bp[0] & 0x0f; 62 if (type == 1) 63 type_s = "advertise"; 64 else 65 type_s = "unknown"; 66 printf("CARPv%d-%s %d: ", version, type_s, len); 67 if (ttl != 255) 68 printf("[ttl=%d!] ", ttl); 69 if (version != 2 || type != 1) 70 return; 71 TCHECK(bp[2]); 72 TCHECK(bp[5]); 73 printf("vhid=%d advbase=%d advskew=%d authlen=%d ", 74 bp[1], bp[5], bp[2], bp[3]); 75 if (vflag) { 76 struct cksum_vec vec[1]; 77 vec[0].ptr = (const u_int8_t *)bp; 78 vec[0].len = len; 79 if (TTEST2(bp[0], len) && in_cksum(vec, 1)) 80 printf(" (bad carp cksum %x!)", 81 EXTRACT_16BITS(&bp[6])); 82 } 83 printf("counter=%" PRIu64, EXTRACT_64BITS(&bp[8])); 84 85 return; 86 trunc: 87 printf("[|carp]"); 88 } 89