xref: /openbsd/usr.sbin/tcpdump/print-ether.c (revision 404b540a)
1 /*	$OpenBSD: print-ether.c,v 1.25 2008/12/05 01:25:24 sthen 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     "@(#) $Id: print-ether.c,v 1.25 2008/12/05 01:25:24 sthen 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 #include "extract.h"
56 
57 const u_char *packetp;
58 const u_char *snapend;
59 
60 void ether_macctl(const u_char *, u_int);
61 
62 void
63 ether_print(register const u_char *bp, u_int length)
64 {
65 	register const struct ether_header *ep;
66 
67 	ep = (const struct ether_header *)bp;
68 	if (qflag) {
69 		TCHECK2(*ep, 12);
70 		(void)printf("%s %s %d: ",
71 			     etheraddr_string(ESRC(ep)),
72 			     etheraddr_string(EDST(ep)),
73 			     length);
74 	} else {
75 		TCHECK2(*ep, 14);
76 		(void)printf("%s %s %s %d: ",
77 			     etheraddr_string(ESRC(ep)),
78 			     etheraddr_string(EDST(ep)),
79 			     etherproto_string(ep->ether_type),
80 			     length);
81 	}
82 	return;
83 trunc:
84 	printf("[|ether] ");
85 }
86 
87 u_short extracted_ethertype;
88 
89 /*
90  * This is the top level routine of the printer.  'p' is the points
91  * to the ether header of the packet, 'tvp' is the timestamp,
92  * 'length' is the length of the packet off the wire, and 'caplen'
93  * is the number of bytes actually captured.
94  */
95 void
96 ether_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
97 {
98 	u_int caplen = h->caplen;
99 	u_int length = h->len;
100 	struct ether_header *ep;
101 	u_short ether_type;
102 
103 	ts_print(&h->ts);
104 
105 	if (caplen < sizeof(struct ether_header)) {
106 		printf("[|ether]");
107 		goto out;
108 	}
109 
110 	/*
111 	 * Some printers want to get back at the ethernet addresses,
112 	 * and/or check that they're not walking off the end of the packet.
113 	 * Rather than pass them all the way down, we set these globals.
114 	 */
115 	packetp = p;
116 	snapend = p + caplen;
117 
118 	if (eflag)
119 		ether_print(p, length);
120 
121 	length -= sizeof(struct ether_header);
122 	caplen -= sizeof(struct ether_header);
123 	ep = (struct ether_header *)p;
124 	p += sizeof(struct ether_header);
125 
126 	ether_type = ntohs(ep->ether_type);
127 
128 	/*
129 	 * Is it (gag) an 802.3 encapsulation?
130 	 */
131 	extracted_ethertype = 0;
132 	if (ether_type <= ETHERMTU) {
133 		/* Try to print the LLC-layer header & higher layers */
134 		if (llc_print(p, length, caplen, ESRC(ep), EDST(ep)) == 0) {
135 			/* ether_type not known, print raw packet */
136 			if (!eflag)
137 				ether_print((u_char *)ep, length);
138 			if (extracted_ethertype) {
139 				printf("(LLC %s) ",
140 			       etherproto_string(htons(extracted_ethertype)));
141 			}
142 			if (!xflag && !qflag)
143 				default_print(p, caplen);
144 		}
145 	} else if (ether_encap_print(ether_type, p, length, caplen) == 0) {
146 		/* ether_type not known, print raw packet */
147 		if (!eflag)
148 			ether_print((u_char *)ep, length + sizeof(*ep));
149 		if (!xflag && !qflag)
150 			default_print(p, caplen);
151 	}
152 	if (xflag)
153 		default_print(p, caplen);
154  out:
155 	putchar('\n');
156 }
157 
158 /*
159  * Prints the packet encapsulated in an Ethernet data segment
160  * (or an equivalent encapsulation), given the Ethernet type code.
161  *
162  * Returns non-zero if it can do so, zero if the ethertype is unknown.
163  *
164  * Stuffs the ether type into a global for the benefit of lower layers
165  * that might want to know what it is.
166  */
167 
168 int
169 ether_encap_print(u_short ethertype, const u_char *p,
170     u_int length, u_int caplen)
171 {
172 recurse:
173 	extracted_ethertype = ethertype;
174 
175 	switch (ethertype) {
176 
177 	case ETHERTYPE_IP:
178 		ip_print(p, length);
179 		return (1);
180 
181 #ifdef INET6
182 	case ETHERTYPE_IPV6:
183 		ip6_print(p, length);
184 		return (1);
185 #endif /*INET6*/
186 
187 	case ETHERTYPE_ARP:
188 	case ETHERTYPE_REVARP:
189 		arp_print(p, length, caplen);
190 		return (1);
191 
192 	case ETHERTYPE_DN:
193 		decnet_print(p, length, caplen);
194 		return (1);
195 
196 	case ETHERTYPE_ATALK:
197 		if (vflag)
198 			fputs("et1 ", stdout);
199 		atalk_print_llap(p, length);
200 		return (1);
201 
202 	case ETHERTYPE_AARP:
203 		aarp_print(p, length);
204 		return (1);
205 
206 	case ETHERTYPE_8021Q:
207 		printf("802.1Q ");
208 	case ETHERTYPE_QINQ:
209 		if (ethertype == ETHERTYPE_QINQ)
210 			printf("QinQ s");
211 		printf("vid %d pri %d%s",
212 		       ntohs(*(unsigned short*)p)&0xFFF,
213 		       ntohs(*(unsigned short*)p)>>13,
214 		       (ntohs(*(unsigned short*)p)&0x1000) ? " cfi " : " ");
215 		ethertype = ntohs(*(unsigned short*)(p+2));
216 		p += 4;
217 		length -= 4;
218 		caplen -= 4;
219 		if (ethertype > ETHERMTU)
220 			goto recurse;
221 
222 		extracted_ethertype = 0;
223 
224 		if (llc_print(p, length, caplen, p-18, p-12) == 0) {
225 			/* ether_type not known, print raw packet */
226 			if (!eflag)
227 				ether_print(p-18, length+4);
228 			if (extracted_ethertype) {
229 				printf("(LLC %s) ",
230 				etherproto_string(htons(extracted_ethertype)));
231 			}
232 			if (!xflag && !qflag)
233 				default_print(p-18, caplen+4);
234 		}
235 		return (1);
236 
237 #ifdef PPP
238 	case ETHERTYPE_PPPOEDISC:
239 	case ETHERTYPE_PPPOE:
240 		pppoe_if_print(ethertype, p, length, caplen);
241 		return (1);
242 #endif
243 
244 	case ETHERTYPE_FLOWCONTROL:
245 		ether_macctl(p, length);
246 		return (1);
247 
248 	case ETHERTYPE_MPLS:
249 	case ETHERTYPE_MPLS_MCAST:
250 		mpls_print(p, length);
251 		return (1);
252 
253 	case ETHERTYPE_LLDP:
254 		lldp_print(p, length);
255 		return (1);
256 
257 	case ETHERTYPE_SLOW:
258 		slow_print(p, length);
259 		return (1);
260 
261 	case ETHERTYPE_LAT:
262 	case ETHERTYPE_SCA:
263 	case ETHERTYPE_MOPRC:
264 	case ETHERTYPE_MOPDL:
265 		/* default_print for now */
266 	default:
267 		return (0);
268 	}
269 }
270 
271 void
272 ether_macctl(const u_char *p, u_int length)
273 {
274 	printf("MACCTL");
275 
276 	if (length < 2)
277 		goto trunc;
278 	if (EXTRACT_16BITS(p) == 0x0001) {
279 		u_int plen;
280 
281 		printf(" PAUSE");
282 
283 		length -= 2;
284 		p += 2;
285 		if (length < 2)
286 			goto trunc;
287 		plen = 512 * EXTRACT_16BITS(p);
288 		printf(" quanta %u", plen);
289 	} else {
290 		printf(" unknown-opcode(0x%04x)", EXTRACT_16BITS(p));
291 	}
292 	return;
293 
294 trunc:
295 	printf("[|MACCTL]");
296 }
297