print-ether.c revision 17681 
1/*
2 * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996
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
22static char rcsid[] =
23    "@(#) $Header: print-ether.c,v 1.42 96/07/23 14:17:23 leres Exp $ (LBL)";
24#endif
25
26#include <sys/param.h>
27#include <sys/time.h>
28#include <sys/socket.h>
29
30#if __STDC__
31struct mbuf;
32struct rtentry;
33#endif
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#include <netinet/tcpip.h>
45
46#include <stdio.h>
47#include <pcap.h>
48
49#include "interface.h"
50#include "addrtoname.h"
51#include "ethertype.h"
52
53const u_char *packetp;
54const u_char *snapend;
55
56static inline void
57ether_print(register const u_char *bp, u_int length)
58{
59	register const struct ether_header *ep;
60
61	ep = (const struct ether_header *)bp;
62	if (qflag)
63		(void)printf("%s %s %d: ",
64			     etheraddr_string(ESRC(ep)),
65			     etheraddr_string(EDST(ep)),
66			     length);
67	else
68		(void)printf("%s %s %s %d: ",
69			     etheraddr_string(ESRC(ep)),
70			     etheraddr_string(EDST(ep)),
71			     etherproto_string(ep->ether_type),
72			     length);
73}
74
75/*
76 * This is the top level routine of the printer.  'p' is the points
77 * to the ether header of the packet, 'tvp' is the timestamp,
78 * 'length' is the length of the packet off the wire, and 'caplen'
79 * is the number of bytes actually captured.
80 */
81void
82ether_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
83{
84	u_int caplen = h->caplen;
85	u_int length = h->len;
86	struct ether_header *ep;
87	u_short ether_type;
88	extern u_short extracted_ethertype;
89
90	ts_print(&h->ts);
91
92	if (caplen < sizeof(struct ether_header)) {
93		printf("[|ether]");
94		goto out;
95	}
96
97	if (eflag)
98		ether_print(p, length);
99
100	/*
101	 * Some printers want to get back at the ethernet addresses,
102	 * and/or check that they're not walking off the end of the packet.
103	 * Rather than pass them all the way down, we set these globals.
104	 */
105	packetp = p;
106	snapend = p + caplen;
107
108	length -= sizeof(struct ether_header);
109	caplen -= sizeof(struct ether_header);
110	ep = (struct ether_header *)p;
111	p += sizeof(struct ether_header);
112
113	ether_type = ntohs(ep->ether_type);
114
115	/*
116	 * Is it (gag) an 802.3 encapsulation?
117	 */
118	extracted_ethertype = 0;
119	if (ether_type < ETHERMTU) {
120		/* Try to print the LLC-layer header & higher layers */
121		if (llc_print(p, length, caplen, ESRC(ep), EDST(ep)) == 0) {
122			/* ether_type not known, print raw packet */
123			if (!eflag)
124				ether_print((u_char *)ep, length);
125			if (extracted_ethertype) {
126				printf("(LLC %s) ",
127			       etherproto_string(htons(extracted_ethertype)));
128			}
129			if (!xflag && !qflag)
130				default_print(p, caplen);
131		}
132	} else if (ether_encap_print(ether_type, p, length, caplen) == 0) {
133		/* ether_type not known, print raw packet */
134		if (!eflag)
135			ether_print((u_char *)ep, length + sizeof(*ep));
136		if (!xflag && !qflag)
137			default_print(p, caplen);
138	}
139	if (xflag)
140		default_print(p, caplen);
141 out:
142	putchar('\n');
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 * Stuffs the ether type into a global for the benefit of lower layers
152 * that might want to know what it is.
153 */
154
155u_short	extracted_ethertype;
156
157int
158ether_encap_print(u_short ethertype, const u_char *p,
159    u_int length, u_int caplen)
160{
161	extracted_ethertype = ethertype;
162
163	switch (ethertype) {
164
165	case ETHERTYPE_IP:
166		ip_print(p, length);
167		return (1);
168
169	case ETHERTYPE_ARP:
170	case ETHERTYPE_REVARP:
171		arp_print(p, length, caplen);
172		return (1);
173
174	case ETHERTYPE_DN:
175		decnet_print(p, length, caplen);
176		return (1);
177
178	case ETHERTYPE_ATALK:
179		if (vflag)
180			fputs("et1 ", stdout);
181		atalk_print(p, length);
182		return (1);
183
184	case ETHERTYPE_AARP:
185		aarp_print(p, length);
186		return (1);
187
188	case ETHERTYPE_LAT:
189	case ETHERTYPE_SCA:
190	case ETHERTYPE_MOPRC:
191	case ETHERTYPE_MOPDL:
192		/* default_print for now */
193	default:
194		return (0);
195	}
196}
197