1 /* $OpenBSD: print-ether.c,v 1.17 2001/02/05 15:18:47 jason 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 1.17 2001/02/05 15:18:47 jason Exp $ (LBL)"; 26 #endif 27 28 #include <sys/param.h> 29 #include <sys/time.h> 30 #include <sys/socket.h> 31 32 #ifdef __STDC__ 33 struct mbuf; 34 struct rtentry; 35 #endif 36 #include <net/if.h> 37 38 #include <netinet/in.h> 39 #include <netinet/if_ether.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 47 #include <stdio.h> 48 #include <pcap.h> 49 50 #ifdef INET6 51 #include <netinet/ip6.h> 52 #endif 53 54 #include "interface.h" 55 #include "addrtoname.h" 56 #include "ethertype.h" 57 58 const u_char *packetp; 59 const u_char *snapend; 60 61 void 62 ether_print(register const u_char *bp, u_int length) 63 { 64 register const struct ether_header *ep; 65 66 ep = (const struct ether_header *)bp; 67 if (qflag) 68 (void)printf("%s %s %d: ", 69 etheraddr_string(ESRC(ep)), 70 etheraddr_string(EDST(ep)), 71 length); 72 else 73 (void)printf("%s %s %s %d: ", 74 etheraddr_string(ESRC(ep)), 75 etheraddr_string(EDST(ep)), 76 etherproto_string(ep->ether_type), 77 length); 78 } 79 80 u_short extracted_ethertype; 81 82 /* 83 * This is the top level routine of the printer. 'p' is the points 84 * to the ether header of the packet, 'tvp' is the timestamp, 85 * 'length' is the length of the packet off the wire, and 'caplen' 86 * is the number of bytes actually captured. 87 */ 88 void 89 ether_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p) 90 { 91 u_int caplen = h->caplen; 92 u_int length = h->len; 93 struct ether_header *ep; 94 u_short ether_type; 95 96 ts_print(&h->ts); 97 98 if (caplen < sizeof(struct ether_header)) { 99 printf("[|ether]"); 100 goto out; 101 } 102 103 if (eflag) 104 ether_print(p, length); 105 106 /* 107 * Some printers want to get back at the ethernet addresses, 108 * and/or check that they're not walking off the end of the packet. 109 * Rather than pass them all the way down, we set these globals. 110 */ 111 packetp = p; 112 snapend = p + caplen; 113 114 length -= sizeof(struct ether_header); 115 caplen -= sizeof(struct ether_header); 116 ep = (struct ether_header *)p; 117 p += sizeof(struct ether_header); 118 119 ether_type = ntohs(ep->ether_type); 120 121 /* 122 * Is it (gag) an 802.3 encapsulation? 123 */ 124 extracted_ethertype = 0; 125 if (ether_type <= ETHERMTU) { 126 /* Try to print the LLC-layer header & higher layers */ 127 if (llc_print(p, length, caplen, ESRC(ep), EDST(ep)) == 0) { 128 /* ether_type not known, print raw packet */ 129 if (!eflag) 130 ether_print((u_char *)ep, length); 131 if (extracted_ethertype) { 132 printf("(LLC %s) ", 133 etherproto_string(htons(extracted_ethertype))); 134 } 135 if (!xflag && !qflag) 136 default_print(p, caplen); 137 } 138 } else if (ether_encap_print(ether_type, p, length, caplen) == 0) { 139 /* ether_type not known, print raw packet */ 140 if (!eflag) 141 ether_print((u_char *)ep, length + sizeof(*ep)); 142 if (!xflag && !qflag) 143 default_print(p, caplen); 144 } 145 if (xflag) 146 default_print(p, caplen); 147 out: 148 putchar('\n'); 149 } 150 151 /* 152 * Prints the packet encapsulated in an Ethernet data segment 153 * (or an equivalent encapsulation), given the Ethernet type code. 154 * 155 * Returns non-zero if it can do so, zero if the ethertype is unknown. 156 * 157 * Stuffs the ether type into a global for the benefit of lower layers 158 * that might want to know what it is. 159 */ 160 161 int 162 ether_encap_print(u_short ethertype, const u_char *p, 163 u_int length, u_int caplen) 164 { 165 recurse: 166 extracted_ethertype = ethertype; 167 168 switch (ethertype) { 169 170 case ETHERTYPE_IP: 171 ip_print(p, length); 172 return (1); 173 174 #ifdef INET6 175 case ETHERTYPE_IPV6: 176 ip6_print(p, length); 177 return (1); 178 #endif /*INET6*/ 179 180 case ETHERTYPE_ARP: 181 case ETHERTYPE_REVARP: 182 arp_print(p, length, caplen); 183 return (1); 184 185 case ETHERTYPE_DN: 186 decnet_print(p, length, caplen); 187 return (1); 188 189 case ETHERTYPE_ATALK: 190 if (vflag) 191 fputs("et1 ", stdout); 192 atalk_print_llap(p, length); 193 return (1); 194 195 case ETHERTYPE_AARP: 196 aarp_print(p, length); 197 return (1); 198 199 case ETHERTYPE_8021Q: 200 printf("802.1Q vid %d pri %d%s", 201 ntohs(*(unsigned short*)p)&0xFFF, 202 ntohs(*(unsigned short*)p)>>13, 203 (ntohs(*(unsigned short*)p)&0x1000) ? " cfi " : " "); 204 ethertype = ntohs(*(unsigned short*)(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) == 0) { 214 /* ether_type not known, print raw packet */ 215 if (!eflag) 216 ether_print(p-18, length+4); 217 if (extracted_ethertype) { 218 printf("(LLC %s) ", 219 etherproto_string(htons(extracted_ethertype))); 220 } 221 if (!xflag && !qflag) 222 default_print(p-18, caplen+4); 223 } 224 return (1); 225 226 #ifdef PPP 227 case ETHERTYPE_PPPOEDISC: 228 case ETHERTYPE_PPPOE: 229 pppoe_if_print(ethertype, p, length, caplen); 230 return (1); 231 #endif 232 233 case ETHERTYPE_LAT: 234 case ETHERTYPE_SCA: 235 case ETHERTYPE_MOPRC: 236 case ETHERTYPE_MOPDL: 237 /* default_print for now */ 238 default: 239 return (0); 240 } 241 } 242