1 /* $OpenBSD: print-arp.c,v 1.13 2015/01/16 06:40:21 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/time.h> 25 #include <sys/socket.h> 26 27 struct mbuf; 28 struct rtentry; 29 #include <net/if.h> 30 31 #include <netinet/in.h> 32 #include <netinet/if_ether.h> 33 34 #include <memory.h> 35 #include <stdio.h> 36 #include <string.h> 37 38 #include "interface.h" 39 #include "addrtoname.h" 40 #include "ethertype.h" 41 #include "extract.h" /* must come after interface.h */ 42 43 /* Compatibility */ 44 #ifndef REVARP_REQUEST 45 #define REVARP_REQUEST 3 46 #endif 47 #ifndef REVARP_REPLY 48 #define REVARP_REPLY 4 49 #endif 50 51 static u_char ezero[6]; 52 53 void 54 arp_print(register const u_char *bp, u_int length, u_int caplen) 55 { 56 register const struct ether_arp *ap; 57 register const struct ether_header *eh; 58 register u_short pro, hrd, op; 59 60 ap = (struct ether_arp *)bp; 61 if ((u_char *)(ap + 1) > snapend) { 62 printf("[|arp]"); 63 return; 64 } 65 if (length < sizeof(struct ether_arp)) { 66 (void)printf("truncated-arp"); 67 default_print((u_char *)ap, length); 68 return; 69 } 70 71 pro = EXTRACT_16BITS(&ap->arp_pro); 72 hrd = EXTRACT_16BITS(&ap->arp_hrd); 73 op = EXTRACT_16BITS(&ap->arp_op); 74 75 if ((pro != ETHERTYPE_IP && pro != ETHERTYPE_TRAIL) 76 || ap->arp_hln != sizeof(SHA(ap)) 77 || ap->arp_pln != sizeof(SPA(ap))) { 78 (void)printf("arp-#%d for proto #%d (%d) hardware #%d (%d)", 79 op, pro, ap->arp_pln, 80 hrd, ap->arp_hln); 81 return; 82 } 83 if (pro == ETHERTYPE_TRAIL) 84 (void)printf("trailer-"); 85 eh = (struct ether_header *)packetp; 86 switch (op) { 87 88 case ARPOP_REQUEST: 89 (void)printf("arp who-has %s", ipaddr_string(TPA(ap))); 90 if (memcmp((char *)ezero, (char *)THA(ap), 6) != 0) 91 (void)printf(" (%s)", etheraddr_string(THA(ap))); 92 (void)printf(" tell %s", ipaddr_string(SPA(ap))); 93 if (memcmp((char *)ESRC(eh), (char *)SHA(ap), 6) != 0) 94 (void)printf(" (%s)", etheraddr_string(SHA(ap))); 95 break; 96 97 case ARPOP_REPLY: 98 (void)printf("arp reply %s", ipaddr_string(SPA(ap))); 99 if (memcmp((char *)ESRC(eh), (char *)SHA(ap), 6) != 0) 100 (void)printf(" (%s)", etheraddr_string(SHA(ap))); 101 (void)printf(" is-at %s", etheraddr_string(SHA(ap))); 102 if (memcmp((char *)EDST(eh), (char *)THA(ap), 6) != 0) 103 (void)printf(" (%s)", etheraddr_string(THA(ap))); 104 break; 105 106 case REVARP_REQUEST: 107 (void)printf("rarp who-is %s tell %s", 108 etheraddr_string(THA(ap)), 109 etheraddr_string(SHA(ap))); 110 break; 111 112 case REVARP_REPLY: 113 (void)printf("rarp reply %s at %s", 114 etheraddr_string(THA(ap)), 115 ipaddr_string(TPA(ap))); 116 break; 117 118 default: 119 (void)printf("arp-#%d", op); 120 default_print((u_char *)ap, caplen); 121 return; 122 } 123 if (hrd != ARPHRD_ETHER) 124 printf(" hardware #%d", hrd); 125 } 126