1 /* 2 * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997 3 * The Regents of the University of California. 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 distributions 7 * retain the above copyright notice and this paragraph in its entirety, (2) 8 * distributions including binary code include the above copyright notice and 9 * this paragraph in its entirety in the documentation or other materials 10 * provided with the distribution, and (3) all advertising materials mentioning 11 * features or use of this software display the following acknowledgement: 12 * ``This product includes software developed by the University of California, 13 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of 14 * the University nor the names of its contributors may be used to endorse 15 * or promote products derived from this software without specific prior 16 * written permission. 17 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED 18 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF 19 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. 20 * 21 * $FreeBSD$ 22 */ 23 24 #ifndef lint 25 static const char rcsid[] = 26 "@(#) $Header: /tcpdump/master/tcpdump/print-arp.c,v 1.44 1999/11/21 09:36:48 fenner Exp $ (LBL)"; 27 #endif 28 29 #ifdef HAVE_CONFIG_H 30 #include "config.h" 31 #endif 32 33 #include <sys/param.h> 34 #include <sys/time.h> 35 #include <sys/socket.h> 36 37 #if __STDC__ 38 struct mbuf; 39 struct rtentry; 40 #endif 41 #include <net/if.h> 42 #include <net/if_var.h> 43 44 #include <netinet/in.h> 45 #include <netinet/if_ether.h> 46 47 #ifdef HAVE_MEMORY_H 48 #include <memory.h> 49 #endif 50 #include <stdio.h> 51 #include <string.h> 52 53 #include "interface.h" 54 #include "addrtoname.h" 55 #include "ethertype.h" 56 #include "extract.h" /* must come after interface.h */ 57 58 /* Compatibility */ 59 #ifndef REVARP_REQUEST 60 #define REVARP_REQUEST 3 61 #endif 62 #ifndef REVARP_REPLY 63 #define REVARP_REPLY 4 64 #endif 65 66 static u_char ezero[6]; 67 68 void 69 arp_print(register const u_char *bp, u_int length, u_int caplen) 70 { 71 register const struct ether_arp *ap; 72 register const struct ether_header *eh; 73 register u_short pro, hrd, op; 74 75 ap = (struct ether_arp *)bp; 76 if ((u_char *)(ap + 1) > snapend) { 77 printf("[|arp]"); 78 return; 79 } 80 if (length < sizeof(struct ether_arp)) { 81 (void)printf("truncated-arp"); 82 default_print((u_char *)ap, length); 83 return; 84 } 85 86 pro = EXTRACT_16BITS(&ap->arp_pro); 87 hrd = EXTRACT_16BITS(&ap->arp_hrd); 88 op = EXTRACT_16BITS(&ap->arp_op); 89 90 if ((pro != ETHERTYPE_IP && pro != ETHERTYPE_TRAIL) 91 || ap->arp_hln != sizeof(SHA(ap)) 92 || ap->arp_pln != sizeof(SPA(ap))) { 93 (void)printf("arp-#%d for proto #%d (%d) hardware #%d (%d)", 94 op, pro, ap->arp_pln, 95 hrd, ap->arp_hln); 96 return; 97 } 98 if (pro == ETHERTYPE_TRAIL) 99 (void)printf("trailer-"); 100 eh = (struct ether_header *)packetp; 101 switch (op) { 102 103 case ARPOP_REQUEST: 104 (void)printf("arp who-has %s", ipaddr_string(TPA(ap))); 105 if (memcmp((char *)ezero, (char *)THA(ap), 6) != 0) 106 (void)printf(" (%s)", etheraddr_string(THA(ap))); 107 (void)printf(" tell %s", ipaddr_string(SPA(ap))); 108 if (memcmp((char *)ESRC(eh), (char *)SHA(ap), 6) != 0) 109 (void)printf(" (%s)", etheraddr_string(SHA(ap))); 110 break; 111 112 case ARPOP_REPLY: 113 (void)printf("arp reply %s", ipaddr_string(SPA(ap))); 114 if (memcmp((char *)ESRC(eh), (char *)SHA(ap), 6) != 0) 115 (void)printf(" (%s)", etheraddr_string(SHA(ap))); 116 (void)printf(" is-at %s", etheraddr_string(SHA(ap))); 117 if (memcmp((char *)EDST(eh), (char *)THA(ap), 6) != 0) 118 (void)printf(" (%s)", etheraddr_string(THA(ap))); 119 break; 120 121 case REVARP_REQUEST: 122 (void)printf("rarp who-is %s tell %s", 123 etheraddr_string(THA(ap)), 124 etheraddr_string(SHA(ap))); 125 break; 126 127 case REVARP_REPLY: 128 (void)printf("rarp reply %s at %s", 129 etheraddr_string(THA(ap)), 130 ipaddr_string(TPA(ap))); 131 break; 132 133 default: 134 (void)printf("arp-#%d", op); 135 default_print((u_char *)ap, caplen); 136 return; 137 } 138 if (hrd != ARPHRD_ETHER) 139 printf(" hardware #%d", hrd); 140 } 141