1 /* $OpenBSD: print-arp.c,v 1.16 2020/01/24 22:46:36 procter 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 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 printf("arp-#%d for proto #%d (%d) hardware #%d (%d)", 78 op, pro, ap->arp_pln, hrd, ap->arp_hln); 79 return; 80 } 81 if (pro == ETHERTYPE_TRAIL) 82 printf("trailer-"); 83 eh = (struct ether_header *)packetp; 84 switch (op) { 85 86 case ARPOP_REQUEST: 87 printf("arp who-has %s", ipaddr_string(TPA(ap))); 88 if (memcmp((char *)ezero, (char *)THA(ap), 6) != 0) 89 printf(" (%s)", etheraddr_string(THA(ap))); 90 printf(" tell %s", ipaddr_string(SPA(ap))); 91 if (memcmp((char *)ESRC(eh), (char *)SHA(ap), 6) != 0) 92 printf(" (%s)", etheraddr_string(SHA(ap))); 93 break; 94 95 case ARPOP_REPLY: 96 printf("arp reply %s", ipaddr_string(SPA(ap))); 97 if (memcmp((char *)ESRC(eh), (char *)SHA(ap), 6) != 0) 98 printf(" (%s)", etheraddr_string(SHA(ap))); 99 printf(" is-at %s", etheraddr_string(SHA(ap))); 100 if (memcmp((char *)EDST(eh), (char *)THA(ap), 6) != 0) 101 printf(" (%s)", etheraddr_string(THA(ap))); 102 break; 103 104 case REVARP_REQUEST: 105 printf("rarp who-is %s tell %s", 106 etheraddr_string(THA(ap)), 107 etheraddr_string(SHA(ap))); 108 break; 109 110 case REVARP_REPLY: 111 printf("rarp reply %s at %s", 112 etheraddr_string(THA(ap)), 113 ipaddr_string(TPA(ap))); 114 break; 115 116 default: 117 printf("arp-#%d", op); 118 default_print((u_char *)ap, caplen); 119 return; 120 } 121 if (hrd != ARPHRD_ETHER) 122 printf(" hardware #%d", hrd); 123 } 124