1 /* $OpenBSD: print-arp.c,v 1.12 2009/10/27 23:59:55 deraadt Exp $ */ 2 3 /* 4 * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that: (1) source code distributions 9 * retain the above copyright notice and this paragraph in its entirety, (2) 10 * distributions including binary code include the above copyright notice and 11 * this paragraph in its entirety in the documentation or other materials 12 * provided with the distribution, and (3) all advertising materials mentioning 13 * features or use of this software display the following acknowledgement: 14 * ``This product includes software developed by the University of California, 15 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of 16 * the University nor the names of its contributors may be used to endorse 17 * or promote products derived from this software without specific prior 18 * written permission. 19 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED 20 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF 21 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. 22 */ 23 24 #include <sys/param.h> 25 #include <sys/time.h> 26 #include <sys/socket.h> 27 28 struct mbuf; 29 struct rtentry; 30 #include <net/if.h> 31 32 #include <netinet/in.h> 33 #include <netinet/if_ether.h> 34 35 #include <memory.h> 36 #include <stdio.h> 37 #include <string.h> 38 39 #include "interface.h" 40 #include "addrtoname.h" 41 #include "ethertype.h" 42 #include "extract.h" /* must come after interface.h */ 43 44 /* Compatibility */ 45 #ifndef REVARP_REQUEST 46 #define REVARP_REQUEST 3 47 #endif 48 #ifndef REVARP_REPLY 49 #define REVARP_REPLY 4 50 #endif 51 52 static u_char ezero[6]; 53 54 void 55 arp_print(register const u_char *bp, u_int length, u_int caplen) 56 { 57 register const struct ether_arp *ap; 58 register const struct ether_header *eh; 59 register u_short pro, hrd, op; 60 61 ap = (struct ether_arp *)bp; 62 if ((u_char *)(ap + 1) > snapend) { 63 printf("[|arp]"); 64 return; 65 } 66 if (length < sizeof(struct ether_arp)) { 67 (void)printf("truncated-arp"); 68 default_print((u_char *)ap, length); 69 return; 70 } 71 72 pro = EXTRACT_16BITS(&ap->arp_pro); 73 hrd = EXTRACT_16BITS(&ap->arp_hrd); 74 op = EXTRACT_16BITS(&ap->arp_op); 75 76 if ((pro != ETHERTYPE_IP && pro != ETHERTYPE_TRAIL) 77 || ap->arp_hln != sizeof(SHA(ap)) 78 || ap->arp_pln != sizeof(SPA(ap))) { 79 (void)printf("arp-#%d for proto #%d (%d) hardware #%d (%d)", 80 op, pro, ap->arp_pln, 81 hrd, ap->arp_hln); 82 return; 83 } 84 if (pro == ETHERTYPE_TRAIL) 85 (void)printf("trailer-"); 86 eh = (struct ether_header *)packetp; 87 switch (op) { 88 89 case ARPOP_REQUEST: 90 (void)printf("arp who-has %s", ipaddr_string(TPA(ap))); 91 if (memcmp((char *)ezero, (char *)THA(ap), 6) != 0) 92 (void)printf(" (%s)", etheraddr_string(THA(ap))); 93 (void)printf(" tell %s", ipaddr_string(SPA(ap))); 94 if (memcmp((char *)ESRC(eh), (char *)SHA(ap), 6) != 0) 95 (void)printf(" (%s)", etheraddr_string(SHA(ap))); 96 break; 97 98 case ARPOP_REPLY: 99 (void)printf("arp reply %s", ipaddr_string(SPA(ap))); 100 if (memcmp((char *)ESRC(eh), (char *)SHA(ap), 6) != 0) 101 (void)printf(" (%s)", etheraddr_string(SHA(ap))); 102 (void)printf(" is-at %s", etheraddr_string(SHA(ap))); 103 if (memcmp((char *)EDST(eh), (char *)THA(ap), 6) != 0) 104 (void)printf(" (%s)", etheraddr_string(THA(ap))); 105 break; 106 107 case REVARP_REQUEST: 108 (void)printf("rarp who-is %s tell %s", 109 etheraddr_string(THA(ap)), 110 etheraddr_string(SHA(ap))); 111 break; 112 113 case REVARP_REPLY: 114 (void)printf("rarp reply %s at %s", 115 etheraddr_string(THA(ap)), 116 ipaddr_string(TPA(ap))); 117 break; 118 119 default: 120 (void)printf("arp-#%d", op); 121 default_print((u_char *)ap, caplen); 122 return; 123 } 124 if (hrd != ARPHRD_ETHER) 125 printf(" hardware #%d", hrd); 126 } 127