1 /* $OpenBSD: print-ether.c,v 1.18 2002/02/19 19:39:40 millert Exp $ */ 2 3 /* 4 * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that: (1) source code distributions 9 * retain the above copyright notice and this paragraph in its entirety, (2) 10 * distributions including binary code include the above copyright notice and 11 * this paragraph in its entirety in the documentation or other materials 12 * provided with the distribution, and (3) all advertising materials mentioning 13 * features or use of this software display the following acknowledgement: 14 * ``This product includes software developed by the University of California, 15 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of 16 * the University nor the names of its contributors may be used to endorse 17 * or promote products derived from this software without specific prior 18 * written permission. 19 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED 20 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF 21 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. 22 */ 23 #ifndef lint 24 static const char rcsid[] = 25 "@(#) $Header: /home/cvs/src/usr.sbin/tcpdump/print-ether.c,v 1.18 2002/02/19 19:39:40 millert Exp $ (LBL)"; 26 #endif 27 28 #include <sys/param.h> 29 #include <sys/time.h> 30 #include <sys/socket.h> 31 32 struct mbuf; 33 struct rtentry; 34 #include <net/if.h> 35 36 #include <netinet/in.h> 37 #include <netinet/if_ether.h> 38 #include <netinet/in_systm.h> 39 #include <netinet/ip.h> 40 #include <netinet/ip_var.h> 41 #include <netinet/udp.h> 42 #include <netinet/udp_var.h> 43 #include <netinet/tcp.h> 44 45 #include <stdio.h> 46 #include <pcap.h> 47 48 #ifdef INET6 49 #include <netinet/ip6.h> 50 #endif 51 52 #include "interface.h" 53 #include "addrtoname.h" 54 #include "ethertype.h" 55 56 const u_char *packetp; 57 const u_char *snapend; 58 59 void 60 ether_print(register const u_char *bp, u_int length) 61 { 62 register const struct ether_header *ep; 63 64 ep = (const struct ether_header *)bp; 65 if (qflag) 66 (void)printf("%s %s %d: ", 67 etheraddr_string(ESRC(ep)), 68 etheraddr_string(EDST(ep)), 69 length); 70 else 71 (void)printf("%s %s %s %d: ", 72 etheraddr_string(ESRC(ep)), 73 etheraddr_string(EDST(ep)), 74 etherproto_string(ep->ether_type), 75 length); 76 } 77 78 u_short extracted_ethertype; 79 80 /* 81 * This is the top level routine of the printer. 'p' is the points 82 * to the ether header of the packet, 'tvp' is the timestamp, 83 * 'length' is the length of the packet off the wire, and 'caplen' 84 * is the number of bytes actually captured. 85 */ 86 void 87 ether_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p) 88 { 89 u_int caplen = h->caplen; 90 u_int length = h->len; 91 struct ether_header *ep; 92 u_short ether_type; 93 94 ts_print(&h->ts); 95 96 if (caplen < sizeof(struct ether_header)) { 97 printf("[|ether]"); 98 goto out; 99 } 100 101 if (eflag) 102 ether_print(p, length); 103 104 /* 105 * Some printers want to get back at the ethernet addresses, 106 * and/or check that they're not walking off the end of the packet. 107 * Rather than pass them all the way down, we set these globals. 108 */ 109 packetp = p; 110 snapend = p + caplen; 111 112 length -= sizeof(struct ether_header); 113 caplen -= sizeof(struct ether_header); 114 ep = (struct ether_header *)p; 115 p += sizeof(struct ether_header); 116 117 ether_type = ntohs(ep->ether_type); 118 119 /* 120 * Is it (gag) an 802.3 encapsulation? 121 */ 122 extracted_ethertype = 0; 123 if (ether_type <= ETHERMTU) { 124 /* Try to print the LLC-layer header & higher layers */ 125 if (llc_print(p, length, caplen, ESRC(ep), EDST(ep)) == 0) { 126 /* ether_type not known, print raw packet */ 127 if (!eflag) 128 ether_print((u_char *)ep, length); 129 if (extracted_ethertype) { 130 printf("(LLC %s) ", 131 etherproto_string(htons(extracted_ethertype))); 132 } 133 if (!xflag && !qflag) 134 default_print(p, caplen); 135 } 136 } else if (ether_encap_print(ether_type, p, length, caplen) == 0) { 137 /* ether_type not known, print raw packet */ 138 if (!eflag) 139 ether_print((u_char *)ep, length + sizeof(*ep)); 140 if (!xflag && !qflag) 141 default_print(p, caplen); 142 } 143 if (xflag) 144 default_print(p, caplen); 145 out: 146 putchar('\n'); 147 } 148 149 /* 150 * Prints the packet encapsulated in an Ethernet data segment 151 * (or an equivalent encapsulation), given the Ethernet type code. 152 * 153 * Returns non-zero if it can do so, zero if the ethertype is unknown. 154 * 155 * Stuffs the ether type into a global for the benefit of lower layers 156 * that might want to know what it is. 157 */ 158 159 int 160 ether_encap_print(u_short ethertype, const u_char *p, 161 u_int length, u_int caplen) 162 { 163 recurse: 164 extracted_ethertype = ethertype; 165 166 switch (ethertype) { 167 168 case ETHERTYPE_IP: 169 ip_print(p, length); 170 return (1); 171 172 #ifdef INET6 173 case ETHERTYPE_IPV6: 174 ip6_print(p, length); 175 return (1); 176 #endif /*INET6*/ 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_llap(p, length); 191 return (1); 192 193 case ETHERTYPE_AARP: 194 aarp_print(p, length); 195 return (1); 196 197 case ETHERTYPE_8021Q: 198 printf("802.1Q vid %d pri %d%s", 199 ntohs(*(unsigned short*)p)&0xFFF, 200 ntohs(*(unsigned short*)p)>>13, 201 (ntohs(*(unsigned short*)p)&0x1000) ? " cfi " : " "); 202 ethertype = ntohs(*(unsigned short*)(p+2)); 203 p += 4; 204 length -= 4; 205 caplen -= 4; 206 if (ethertype > ETHERMTU) 207 goto recurse; 208 209 extracted_ethertype = 0; 210 211 if (llc_print(p, length, caplen, p-18, p-12) == 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 #ifdef PPP 225 case ETHERTYPE_PPPOEDISC: 226 case ETHERTYPE_PPPOE: 227 pppoe_if_print(ethertype, p, length, caplen); 228 return (1); 229 #endif 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