1 /* $OpenBSD: print-arp.c,v 1.15 2015/11/18 15:36:20 mmcc 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 <stdio.h> 35 #include <string.h> 36 37 #include "interface.h" 38 #include "addrtoname.h" 39 #include "ethertype.h" 40 #include "extract.h" /* must come after interface.h */ 41 42 /* Compatibility */ 43 #ifndef REVARP_REQUEST 44 #define REVARP_REQUEST 3 45 #endif 46 #ifndef REVARP_REPLY 47 #define REVARP_REPLY 4 48 #endif 49 50 static u_char ezero[6]; 51 52 void 53 arp_print(const u_char *bp, u_int length, u_int caplen) 54 { 55 const struct ether_arp *ap; 56 const struct ether_header *eh; 57 u_short pro, hrd, op; 58 59 ap = (struct ether_arp *)bp; 60 if ((u_char *)(ap + 1) > snapend) { 61 printf("[|arp]"); 62 return; 63 } 64 if (length < sizeof(struct ether_arp)) { 65 (void)printf("truncated-arp"); 66 default_print((u_char *)ap, length); 67 return; 68 } 69 70 pro = EXTRACT_16BITS(&ap->arp_pro); 71 hrd = EXTRACT_16BITS(&ap->arp_hrd); 72 op = EXTRACT_16BITS(&ap->arp_op); 73 74 if ((pro != ETHERTYPE_IP && pro != ETHERTYPE_TRAIL) 75 || ap->arp_hln != sizeof(SHA(ap)) 76 || ap->arp_pln != sizeof(SPA(ap))) { 77 (void)printf("arp-#%d for proto #%d (%d) hardware #%d (%d)", 78 op, pro, ap->arp_pln, 79 hrd, ap->arp_hln); 80 return; 81 } 82 if (pro == ETHERTYPE_TRAIL) 83 (void)printf("trailer-"); 84 eh = (struct ether_header *)packetp; 85 switch (op) { 86 87 case ARPOP_REQUEST: 88 (void)printf("arp who-has %s", ipaddr_string(TPA(ap))); 89 if (memcmp((char *)ezero, (char *)THA(ap), 6) != 0) 90 (void)printf(" (%s)", etheraddr_string(THA(ap))); 91 (void)printf(" tell %s", ipaddr_string(SPA(ap))); 92 if (memcmp((char *)ESRC(eh), (char *)SHA(ap), 6) != 0) 93 (void)printf(" (%s)", etheraddr_string(SHA(ap))); 94 break; 95 96 case ARPOP_REPLY: 97 (void)printf("arp reply %s", ipaddr_string(SPA(ap))); 98 if (memcmp((char *)ESRC(eh), (char *)SHA(ap), 6) != 0) 99 (void)printf(" (%s)", etheraddr_string(SHA(ap))); 100 (void)printf(" is-at %s", etheraddr_string(SHA(ap))); 101 if (memcmp((char *)EDST(eh), (char *)THA(ap), 6) != 0) 102 (void)printf(" (%s)", etheraddr_string(THA(ap))); 103 break; 104 105 case REVARP_REQUEST: 106 (void)printf("rarp who-is %s tell %s", 107 etheraddr_string(THA(ap)), 108 etheraddr_string(SHA(ap))); 109 break; 110 111 case REVARP_REPLY: 112 (void)printf("rarp reply %s at %s", 113 etheraddr_string(THA(ap)), 114 ipaddr_string(TPA(ap))); 115 break; 116 117 default: 118 (void)printf("arp-#%d", op); 119 default_print((u_char *)ap, caplen); 120 return; 121 } 122 if (hrd != ARPHRD_ETHER) 123 printf(" hardware #%d", hrd); 124 } 125