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