print-ether.c revision 53146
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 53146 1999-11-14 11:28:11Z brian $ 22 */ 23#ifndef lint 24static const char rcsid[] = 25 "@(#) $Header: print-ether.c,v 1.44 97/05/26 17:18:13 leres Exp $ (LBL)"; 26#endif 27 28#include <sys/param.h> 29#include <sys/time.h> 30#include <sys/socket.h> 31 32#if __STDC__ 33struct mbuf; 34struct rtentry; 35#endif 36#include <net/if.h> 37 38#include <netinet/in.h> 39#include <net/ethernet.h> 40#include <netinet/in_systm.h> 41#include <netinet/ip.h> 42#include <netinet/ip_var.h> 43#include <netinet/udp.h> 44#include <netinet/udp_var.h> 45#include <netinet/tcp.h> 46#include <netinet/tcpip.h> 47 48#include <stdio.h> 49#include <pcap.h> 50 51#include "interface.h" 52#include "addrtoname.h" 53#include "ethertype.h" 54 55const u_char *packetp; 56const u_char *snapend; 57 58static inline void 59ether_print(register const u_char *bp, u_int length) 60{ 61 register const struct ether_header *ep; 62 63 ep = (const struct ether_header *)bp; 64 if (qflag) 65 (void)printf("%s %s %d: ", 66 etheraddr_string(ESRC(ep)), 67 etheraddr_string(EDST(ep)), 68 length); 69 else 70 (void)printf("%s %s %s %d: ", 71 etheraddr_string(ESRC(ep)), 72 etheraddr_string(EDST(ep)), 73 etherproto_string(ep->ether_type), 74 length); 75} 76 77/* 78 * This is the top level routine of the printer. 'p' is the points 79 * to the ether header of the packet, 'tvp' is the timestamp, 80 * 'length' is the length of the packet off the wire, and 'caplen' 81 * is the number of bytes actually captured. 82 */ 83void 84ether_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p) 85{ 86 u_int caplen = h->caplen; 87 u_int length = h->len; 88 struct ether_header *ep; 89 u_short ether_type; 90 extern u_short extracted_ethertype; 91 92 ts_print(&h->ts); 93 94 if (caplen < sizeof(struct ether_header)) { 95 printf("[|ether]"); 96 goto out; 97 } 98 99 if (eflag) 100 ether_print(p, length); 101 102 /* 103 * Some printers want to get back at the ethernet addresses, 104 * and/or check that they're not walking off the end of the packet. 105 * Rather than pass them all the way down, we set these globals. 106 */ 107 packetp = p; 108 snapend = p + caplen; 109 110 length -= sizeof(struct ether_header); 111 caplen -= sizeof(struct ether_header); 112 ep = (struct ether_header *)p; 113 p += sizeof(struct ether_header); 114 115 ether_type = ntohs(ep->ether_type); 116 117 /* 118 * Is it (gag) an 802.3 encapsulation? 119 */ 120 extracted_ethertype = 0; 121 if (ether_type <= ETHERMTU) { 122 /* Try to print the LLC-layer header & higher layers */ 123 if (llc_print(p, length, caplen, ESRC(ep), EDST(ep)) == 0) { 124 /* ether_type not known, print raw packet */ 125 if (!eflag) 126 ether_print((u_char *)ep, length); 127 if (extracted_ethertype) { 128 printf("(LLC %s) ", 129 etherproto_string(htons(extracted_ethertype))); 130 } 131 if (!xflag && !qflag) 132 default_print(p, caplen); 133 } 134 } else if (ether_encap_print(ether_type, p, length, caplen) == 0) { 135 /* ether_type not known, print raw packet */ 136 if (!eflag) 137 ether_print((u_char *)ep, length + sizeof(*ep)); 138 if (!xflag && !qflag) 139 default_print(p, caplen); 140 } 141 if (xflag) 142 default_print(p, caplen); 143 out: 144 putchar('\n'); 145} 146 147/* 148 * Prints the packet encapsulated in an Ethernet data segment 149 * (or an equivalent encapsulation), given the Ethernet type code. 150 * 151 * Returns non-zero if it can do so, zero if the ethertype is unknown. 152 * 153 * Stuffs the ether type into a global for the benefit of lower layers 154 * that might want to know what it is. 155 */ 156 157u_short extracted_ethertype; 158 159int 160ether_encap_print(u_short ethertype, const u_char *p, 161 u_int length, u_int caplen) 162{ 163 if (ethertype == 0x8100) { /* IEEE 802.1Q vlan tagging encapsulation */ 164 printf ("[vlan %d] ", ntohs(*(u_short *)p) & 0x17ff); 165 ethertype = ntohs(((u_short *)p)[1]); 166 p += 4; 167 length -= 4; 168 caplen -= 4; 169 } 170 extracted_ethertype = ethertype; 171 172 switch (ethertype) { 173 174 case ETHERTYPE_IP: 175 ip_print(p, length); 176 return (1); 177 178 case ETHERTYPE_ARP: 179 case ETHERTYPE_REVARP: 180 arp_print(p, length, caplen); 181 return (1); 182 183 case ETHERTYPE_DN: 184 decnet_print(p, length, caplen); 185 return (1); 186 187 case ETHERTYPE_ATALK: 188 if (vflag) 189 fputs("et1 ", stdout); 190 atalk_print(p, length); 191 return (1); 192 193 case ETHERTYPE_AARP: 194 aarp_print(p, length); 195 return (1); 196 197 case ETHERTYPE_IPX: 198 ipx_print(p, length); 199 return (1); 200 201 case ETHERTYPE_PPPOE_DISC: 202 case ETHERTYPE_PPPOE_SESS: 203 pppoe_print(p, length); 204 return (1); 205 206 case ETHERTYPE_LAT: 207 case ETHERTYPE_SCA: 208 case ETHERTYPE_MOPRC: 209 case ETHERTYPE_MOPDL: 210 /* default_print for now */ 211 default: 212 return (0); 213 } 214} 215