print-ether.c revision 75118
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: head/contrib/tcpdump/print-ether.c 75118 2001-04-03 07:50:46Z fenner $ 22 */ 23#ifndef lint 24static const char rcsid[] = 25 "@(#) $Header: /tcpdump/master/tcpdump/print-ether.c,v 1.61 2000/12/22 22:45:10 guy Exp $ (LBL)"; 26#endif 27 28#ifdef HAVE_CONFIG_H 29#include "config.h" 30#endif 31 32#include <sys/param.h> 33#include <sys/time.h> 34#include <sys/socket.h> 35 36struct mbuf; 37struct rtentry; 38 39#include <netinet/in.h> 40 41#include <stdio.h> 42#include <pcap.h> 43 44#include "interface.h" 45#include "addrtoname.h" 46#include "ethertype.h" 47 48#include "ether.h" 49 50const u_char *packetp; 51const u_char *snapend; 52 53static inline void 54ether_print(register const u_char *bp, u_int length) 55{ 56 register const struct ether_header *ep; 57 58 ep = (const struct ether_header *)bp; 59 if (qflag) 60 (void)printf("%s %s %d: ", 61 etheraddr_string(ESRC(ep)), 62 etheraddr_string(EDST(ep)), 63 length); 64 else 65 (void)printf("%s %s %s %d: ", 66 etheraddr_string(ESRC(ep)), 67 etheraddr_string(EDST(ep)), 68 etherproto_string(ep->ether_type), 69 length); 70} 71 72/* 73 * This is the top level routine of the printer. 'p' is the points 74 * to the ether header of the packet, 'h->tv' is the timestamp, 75 * 'h->length' is the length of the packet off the wire, and 'h->caplen' 76 * is the number of bytes actually captured. 77 */ 78void 79ether_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p) 80{ 81 u_int caplen = h->caplen; 82 u_int length = h->len; 83 struct ether_header *ep; 84 u_short ether_type; 85 u_short extracted_ethertype; 86 87 ts_print(&h->ts); 88 89 if (caplen < ETHER_HDRLEN) { 90 printf("[|ether]"); 91 goto out; 92 } 93 94 if (eflag) 95 ether_print(p, length); 96 97 /* 98 * Some printers want to get back at the ethernet addresses, 99 * and/or check that they're not walking off the end of the packet. 100 * Rather than pass them all the way down, we set these globals. 101 */ 102 packetp = p; 103 snapend = p + caplen; 104 105 length -= ETHER_HDRLEN; 106 caplen -= ETHER_HDRLEN; 107 ep = (struct ether_header *)p; 108 p += ETHER_HDRLEN; 109 110 ether_type = ntohs(ep->ether_type); 111 112 /* 113 * Is it (gag) an 802.3 encapsulation? 114 */ 115 extracted_ethertype = 0; 116 if (ether_type <= ETHERMTU) { 117 /* Try to print the LLC-layer header & higher layers */ 118 if (llc_print(p, length, caplen, ESRC(ep), EDST(ep), 119 &extracted_ethertype) == 0) { 120 /* ether_type not known, print raw packet */ 121 if (!eflag) 122 ether_print((u_char *)ep, length + ETHER_HDRLEN); 123 if (extracted_ethertype) { 124 printf("(LLC %s) ", 125 etherproto_string(htons(extracted_ethertype))); 126 } 127 if (!xflag && !qflag) 128 default_print(p, caplen); 129 } 130 } else if (ether_encap_print(ether_type, p, length, caplen, 131 &extracted_ethertype) == 0) { 132 /* ether_type not known, print raw packet */ 133 if (!eflag) 134 ether_print((u_char *)ep, length + ETHER_HDRLEN); 135 if (!xflag && !qflag) 136 default_print(p, caplen); 137 } 138 if (xflag) 139 default_print(p, caplen); 140 out: 141 putchar('\n'); 142} 143 144/* 145 * Prints the packet encapsulated in an Ethernet data segment 146 * (or an equivalent encapsulation), given the Ethernet type code. 147 * 148 * Returns non-zero if it can do so, zero if the ethertype is unknown. 149 * 150 * The Ethernet type code is passed through a pointer; if it was 151 * ETHERTYPE_8021Q, it gets updated to be the Ethernet type of 152 * the 802.1Q payload, for the benefit of lower layers that might 153 * want to know what it is. 154 */ 155 156int 157ether_encap_print(u_short ethertype, const u_char *p, 158 u_int length, u_int caplen, u_short *extracted_ethertype) 159{ 160 recurse: 161 *extracted_ethertype = ethertype; 162 163 switch (ethertype) { 164 165 case ETHERTYPE_IP: 166 ip_print(p, length); 167 return (1); 168 169#ifdef INET6 170 case ETHERTYPE_IPV6: 171 ip6_print(p, length); 172 return (1); 173#endif /*INET6*/ 174 175 case ETHERTYPE_ARP: 176 case ETHERTYPE_REVARP: 177 arp_print(p, length, caplen); 178 return (1); 179 180 case ETHERTYPE_DN: 181 decnet_print(p, length, caplen); 182 return (1); 183 184 case ETHERTYPE_ATALK: 185 if (vflag) 186 fputs("et1 ", stdout); 187 atalk_print(p, length); 188 return (1); 189 190 case ETHERTYPE_AARP: 191 aarp_print(p, length); 192 return (1); 193 194 case ETHERTYPE_IPX: 195 ipx_print(p, length); 196 return (1); 197 198 case ETHERTYPE_8021Q: 199 printf("802.1Q vlan#%d P%d%s ", 200 ntohs(*(u_int16_t *)p) & 0xfff, 201 ntohs(*(u_int16_t *)p) >> 13, 202 (ntohs(*(u_int16_t *)p) & 0x1000) ? " CFI" : ""); 203 ethertype = ntohs(*(u_int16_t *)(p + 2)); 204 p += 4; 205 length -= 4; 206 caplen -= 4; 207 if (ethertype > ETHERMTU) 208 goto recurse; 209 210 *extracted_ethertype = 0; 211 212 if (llc_print(p, length, caplen, p - 18, p - 12, 213 extracted_ethertype) == 0) { 214 /* ether_type not known, print raw packet */ 215 if (!eflag) 216 ether_print(p - 18, length + 4); 217 if (*extracted_ethertype) { 218 printf("(LLC %s) ", 219 etherproto_string(htons(*extracted_ethertype))); 220 } 221 if (!xflag && !qflag) 222 default_print(p - 18, caplen + 4); 223 } 224 return (1); 225 226 case ETHERTYPE_PPPOED: 227 case ETHERTYPE_PPPOES: 228 pppoe_print(p, length); 229 return (1); 230 231 case ETHERTYPE_LAT: 232 case ETHERTYPE_SCA: 233 case ETHERTYPE_MOPRC: 234 case ETHERTYPE_MOPDL: 235 /* default_print for now */ 236 default: 237 return (0); 238 } 239} 240