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 #ifndef lint 22 static const char rcsid[] = 23 "@(#) $Header: /tcpdump/master/tcpdump/print-ether.c,v 1.65 2001/07/04 22:03:14 fenner 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 ++infodelay; 86 ts_print(&h->ts); 87 88 if (caplen < ETHER_HDRLEN) { 89 printf("[|ether]"); 90 goto out; 91 } 92 93 if (eflag) 94 ether_print(p, length); 95 96 /* 97 * Some printers want to get back at the ethernet addresses, 98 * and/or check that they're not walking off the end of the packet. 99 * Rather than pass them all the way down, we set these globals. 100 */ 101 packetp = p; 102 snapend = p + caplen; 103 104 length -= ETHER_HDRLEN; 105 caplen -= ETHER_HDRLEN; 106 ep = (struct ether_header *)p; 107 p += ETHER_HDRLEN; 108 109 ether_type = ntohs(ep->ether_type); 110 111 /* 112 * Is it (gag) an 802.3 encapsulation? 113 */ 114 extracted_ethertype = 0; 115 if (ether_type <= ETHERMTU) { 116 /* Try to print the LLC-layer header & higher layers */ 117 if (llc_print(p, length, caplen, ESRC(ep), EDST(ep), 118 &extracted_ethertype) == 0) { 119 /* ether_type not known, print raw packet */ 120 if (!eflag) 121 ether_print((u_char *)ep, length + ETHER_HDRLEN); 122 if (extracted_ethertype) { 123 printf("(LLC %s) ", 124 etherproto_string(htons(extracted_ethertype))); 125 } 126 if (!xflag && !qflag) 127 default_print(p, caplen); 128 } 129 } else if (ether_encap_print(ether_type, p, length, caplen, 130 &extracted_ethertype) == 0) { 131 /* ether_type not known, print raw packet */ 132 if (!eflag) 133 ether_print((u_char *)ep, length + ETHER_HDRLEN); 134 if (!xflag && !qflag) 135 default_print(p, caplen); 136 } 137 if (xflag) 138 default_print(p, caplen); 139 out: 140 putchar('\n'); 141 --infodelay; 142 if (infoprint) 143 info(0); 144 } 145 146 /* 147 * Prints the packet encapsulated in an Ethernet data segment 148 * (or an equivalent encapsulation), given the Ethernet type code. 149 * 150 * Returns non-zero if it can do so, zero if the ethertype is unknown. 151 * 152 * The Ethernet type code is passed through a pointer; if it was 153 * ETHERTYPE_8021Q, it gets updated to be the Ethernet type of 154 * the 802.1Q payload, for the benefit of lower layers that might 155 * want to know what it is. 156 */ 157 158 int 159 ether_encap_print(u_short ethertype, const u_char *p, 160 u_int length, u_int caplen, u_short *extracted_ethertype) 161 { 162 recurse: 163 *extracted_ethertype = ethertype; 164 165 switch (ethertype) { 166 167 case ETHERTYPE_IP: 168 ip_print(p, length); 169 return (1); 170 171 #ifdef INET6 172 case ETHERTYPE_IPV6: 173 ip6_print(p, length); 174 return (1); 175 #endif /*INET6*/ 176 177 case ETHERTYPE_ARP: 178 case ETHERTYPE_REVARP: 179 arp_print(p, length, caplen); 180 return (1); 181 182 case ETHERTYPE_DN: 183 decnet_print(p, length, caplen); 184 return (1); 185 186 case ETHERTYPE_ATALK: 187 if (vflag) 188 fputs("et1 ", stdout); 189 atalk_print(p, length); 190 return (1); 191 192 case ETHERTYPE_AARP: 193 aarp_print(p, length); 194 return (1); 195 196 case ETHERTYPE_IPX: 197 ipx_print(p, length); 198 return (1); 199 200 case ETHERTYPE_8021Q: 201 printf("802.1Q vlan#%d P%d%s ", 202 ntohs(*(u_int16_t *)p) & 0xfff, 203 ntohs(*(u_int16_t *)p) >> 13, 204 (ntohs(*(u_int16_t *)p) & 0x1000) ? " CFI" : ""); 205 ethertype = ntohs(*(u_int16_t *)(p + 2)); 206 p += 4; 207 length -= 4; 208 caplen -= 4; 209 if (ethertype > ETHERMTU) 210 goto recurse; 211 212 *extracted_ethertype = 0; 213 214 if (llc_print(p, length, caplen, p - 18, p - 12, 215 extracted_ethertype) == 0) { 216 /* ether_type not known, print raw packet */ 217 if (!eflag) 218 ether_print(p - 18, length + 4); 219 if (*extracted_ethertype) { 220 printf("(LLC %s) ", 221 etherproto_string(htons(*extracted_ethertype))); 222 } 223 if (!xflag && !qflag) 224 default_print(p - 18, caplen + 4); 225 } 226 return (1); 227 228 case ETHERTYPE_PPPOED: 229 case ETHERTYPE_PPPOES: 230 pppoe_print(p, length); 231 return (1); 232 233 case ETHERTYPE_PPP: 234 printf("ppp"); 235 if (length) { 236 printf(": "); 237 ppp_print(p, length); 238 } 239 return (1); 240 241 case ETHERTYPE_MPLS: 242 case ETHERTYPE_MPLS_MULTI: 243 mpls_print(p, length); 244 return (1); 245 246 case ETHERTYPE_LAT: 247 case ETHERTYPE_SCA: 248 case ETHERTYPE_MOPRC: 249 case ETHERTYPE_MOPDL: 250 /* default_print for now */ 251 default: 252 return (0); 253 } 254 } 255