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 (at) 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 46 #include "interface.h" 47 #include "extract.h" 48 #include "addrtoname.h" 49 50 void 51 carp_print(register const u_char *bp, register u_int len, int ttl) 52 { 53 int version, type; 54 const char *type_s; 55 56 TCHECK(bp[0]); 57 version = (bp[0] & 0xf0) >> 4; 58 type = bp[0] & 0x0f; 59 if (type == 1) 60 type_s = "advertise"; 61 else 62 type_s = "unknown"; 63 printf("CARPv%d-%s %d: ", version, type_s, len); 64 if (ttl != 255) 65 printf("[ttl=%d!] ", ttl); 66 if (version != 2 || type != 1) 67 return; 68 TCHECK(bp[2]); 69 TCHECK(bp[5]); 70 printf("vhid=%d advbase=%d advskew=%d authlen=%d ", 71 bp[1], bp[5], bp[2], bp[3]); 72 if (vflag) { 73 struct cksum_vec vec[1]; 74 vec[0].ptr = (const u_int8_t *)bp; 75 vec[0].len = len; 76 if (TTEST2(bp[0], len) && in_cksum(vec, 1)) 77 printf(" (bad carp cksum %x!)", 78 EXTRACT_16BITS(&bp[6])); 79 } 80 printf("counter=%" PRIu64, EXTRACT_64BITS(&bp[8])); 81 82 return; 83 trunc: 84 printf("[|carp]"); 85 } 86
