1 /* 2 * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000 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 * $FreeBSD$ 22 */ 23 #ifndef lint 24 static const char rcsid[] = 25 "@(#) $Header: /tcpdump/master/tcpdump/print-ether.c,v 1.65.4.1 2002/06/01 23:51:12 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 36 #include <netinet/in.h> 37 38 #include <stdio.h> 39 #include <pcap.h> 40 41 #include "interface.h" 42 #include "addrtoname.h" 43 #include "ethertype.h" 44 45 #include "ether.h" 46 47 const u_char *packetp; 48 const u_char *snapend; 49 50 static inline void 51 ether_print(register const u_char *bp, u_int length) 52 { 53 register const struct ether_header *ep; 54 55 ep = (const struct ether_header *)bp; 56 if (qflag) 57 (void)printf("%s %s %d: ", 58 etheraddr_string(ESRC(ep)), 59 etheraddr_string(EDST(ep)), 60 length); 61 else 62 (void)printf("%s %s %s %d: ", 63 etheraddr_string(ESRC(ep)), 64 etheraddr_string(EDST(ep)), 65 etherproto_string(ep->ether_type), 66 length); 67 } 68 69 /* 70 * This is the top level routine of the printer. 'p' is the points 71 * to the ether header of the packet, 'h->tv' is the timestamp, 72 * 'h->length' is the length of the packet off the wire, and 'h->caplen' 73 * is the number of bytes actually captured. 74 */ 75 void 76 ether_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p) 77 { 78 u_int caplen = h->caplen; 79 u_int length = h->len; 80 struct ether_header *ep; 81 u_short ether_type; 82 u_short extracted_ethertype; 83 84 ++infodelay; 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 --infodelay; 141 if (infoprint) 142 info(0); 143 } 144 145 /* 146 * Prints the packet encapsulated in an Ethernet data segment 147 * (or an equivalent encapsulation), given the Ethernet type code. 148 * 149 * Returns non-zero if it can do so, zero if the ethertype is unknown. 150 * 151 * The Ethernet type code is passed through a pointer; if it was 152 * ETHERTYPE_8021Q, it gets updated to be the Ethernet type of 153 * the 802.1Q payload, for the benefit of lower layers that might 154 * want to know what it is. 155 */ 156 157 int 158 ether_encap_print(u_short ethertype, const u_char *p, 159 u_int length, u_int caplen, u_short *extracted_ethertype) 160 { 161 recurse: 162 *extracted_ethertype = ethertype; 163 164 switch (ethertype) { 165 166 case ETHERTYPE_IP: 167 ip_print(p, length); 168 return (1); 169 170 #ifdef INET6 171 case ETHERTYPE_IPV6: 172 ip6_print(p, length); 173 return (1); 174 #endif /*INET6*/ 175 176 case ETHERTYPE_ARP: 177 case ETHERTYPE_REVARP: 178 arp_print(p, length, caplen); 179 return (1); 180 181 case ETHERTYPE_DN: 182 decnet_print(p, length, caplen); 183 return (1); 184 185 case ETHERTYPE_ATALK: 186 if (vflag) 187 fputs("et1 ", stdout); 188 atalk_print(p, length); 189 return (1); 190 191 case ETHERTYPE_AARP: 192 aarp_print(p, length); 193 return (1); 194 195 case ETHERTYPE_IPX: 196 ipx_print(p, length); 197 return (1); 198 199 case ETHERTYPE_8021Q: 200 printf("802.1Q vlan#%d P%d%s ", 201 ntohs(*(u_int16_t *)p) & 0xfff, 202 ntohs(*(u_int16_t *)p) >> 13, 203 (ntohs(*(u_int16_t *)p) & 0x1000) ? " CFI" : ""); 204 ethertype = ntohs(*(u_int16_t *)(p + 2)); 205 p += 4; 206 length -= 4; 207 caplen -= 4; 208 if (ethertype > ETHERMTU) 209 goto recurse; 210 211 *extracted_ethertype = 0; 212 213 if (llc_print(p, length, caplen, p - 18, p - 12, 214 extracted_ethertype) == 0) { 215 /* ether_type not known, print raw packet */ 216 if (!eflag) 217 ether_print(p - 18, length + 4); 218 if (*extracted_ethertype) { 219 printf("(LLC %s) ", 220 etherproto_string(htons(*extracted_ethertype))); 221 } 222 if (!xflag && !qflag) 223 default_print(p - 18, caplen + 4); 224 } 225 return (1); 226 227 case ETHERTYPE_PPPOED: 228 case ETHERTYPE_PPPOES: 229 case ETHERTYPE_PPPOED2: 230 case ETHERTYPE_PPPOES2: 231 pppoe_print(p, length); 232 return (1); 233 234 case ETHERTYPE_PPP: 235 printf("ppp"); 236 if (length) { 237 printf(": "); 238 ppp_print(p, length); 239 } 240 return (1); 241 242 case ETHERTYPE_MPLS: 243 case ETHERTYPE_MPLS_MULTI: 244 mpls_print(p, length); 245 return (1); 246 247 case ETHERTYPE_LAT: 248 case ETHERTYPE_SCA: 249 case ETHERTYPE_MOPRC: 250 case ETHERTYPE_MOPDL: 251 /* default_print for now */ 252 default: 253 return (0); 254 } 255 } 256