xref: /openbsd-src/usr.sbin/tcpdump/print-null.c (revision 5f8c363d34596ac16355250fc26c64796db04466)
1 /*	$OpenBSD: print-null.c,v 1.15 2002/01/23 23:32:20 mickey Exp $	*/
2 
3 /*
4  * Copyright (c) 1991, 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 
24 #ifndef lint
25 static const char rcsid[] =
26     "@(#) $Header: /home/cvs/src/usr.sbin/tcpdump/print-null.c,v 1.15 2002/01/23 23:32:20 mickey Exp $ (LBL)";
27 #endif
28 
29 #include <sys/param.h>
30 #include <sys/time.h>
31 #include <sys/socket.h>
32 #include <sys/file.h>
33 #include <sys/ioctl.h>
34 
35 #ifdef __STDC__
36 struct mbuf;
37 struct rtentry;
38 #endif
39 #include <net/if.h>
40 
41 #include <netinet/in.h>
42 #include <netinet/in_systm.h>
43 #include <netinet/ip.h>
44 #include <netinet/if_ether.h>
45 #include <netinet/ip_var.h>
46 #include <netinet/udp.h>
47 #include <netinet/udp_var.h>
48 #include <netinet/tcp.h>
49 
50 #include <pcap.h>
51 #include <stdio.h>
52 #include <string.h>
53 
54 #ifdef INET6
55 #include <netinet/ip6.h>
56 #endif
57 
58 #include "interface.h"
59 #include "addrtoname.h"
60 
61 #ifndef AF_NS
62 #define AF_NS		6		/* XEROX NS protocols */
63 #endif
64 
65 /*
66  * The DLT_NULL packet header is 4 bytes long. It contains a host
67  * order 32 bit integer that specifies the family, e.g. AF_INET
68  */
69 #define	NULL_HDRLEN 4
70 
71 static void
72 null_print(const u_char *p, const struct ip *ip, u_int length)
73 {
74 	u_int family;
75 
76 	memcpy((char *)&family, (char *)p, sizeof(family));
77 
78 	if (nflag && family != AF_LINK) {
79 		/* XXX just dump the header */
80 		return;
81 	}
82 	switch (family) {
83 
84 	case AF_INET:
85 		printf("ip: ");
86 		break;
87 
88 #ifdef INET6
89 	case AF_INET6:
90 		printf("ip6: ");
91 		break;
92 #endif
93 
94 	case AF_NS:
95 		printf("ns: ");
96 		break;
97 
98 #ifdef __OpenBSD__
99 	case AF_LINK:
100 		ether_print(p + NULL_HDRLEN, length);
101 		break;
102 #endif
103 
104 	default:
105 		printf("AF %d: ", family);
106 		break;
107 	}
108 }
109 
110 void
111 loop_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
112 {
113 	*(u_int *)p = ntohl(*(u_int *)p);
114 
115 	null_if_print(user, h, p);
116 }
117 
118 void
119 null_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
120 {
121 	u_int length = h->len;
122 	u_int caplen = h->caplen;
123 	u_int family = *(u_int *)p;
124 
125 #ifdef __OpenBSD__
126 	struct ether_header *ep;
127 	u_short ether_type;
128 	extern u_short extracted_ethertype;
129 #endif
130 
131 	ts_print(&h->ts);
132 
133 	/*
134 	 * Some printers want to get back at the link level addresses,
135 	 * and/or check that they're not walking off the end of the packet.
136 	 * Rather than pass them all the way down, we set these globals.
137 	 */
138 	packetp = p;
139 	snapend = p + caplen;
140 
141 	length -= NULL_HDRLEN;
142 
143 	if (eflag)
144 		null_print(p, (struct ip *)(p + NULL_HDRLEN), length);
145 
146 	switch (family) {
147 	case AF_INET:
148 		ip_print(p + NULL_HDRLEN, length);
149 		break;
150 
151 #ifdef INET6
152 	case AF_INET6:
153 		ip6_print(p + NULL_HDRLEN, length);
154 		break;
155 #endif /*INET6*/
156 
157 #ifdef __OpenBSD__
158 	case AF_LINK:
159 		if (caplen < sizeof(struct ether_header) + NULL_HDRLEN) {
160 			printf("[|ether]");
161 			goto out;
162 		}
163 
164 		length -= sizeof(struct ether_header);
165 		caplen -= sizeof(struct ether_header);
166 		ep = (struct ether_header *)(p + NULL_HDRLEN);
167 		p += NULL_HDRLEN + sizeof(struct ether_header);
168 		packetp += sizeof(struct ether_header);
169 		ether_type = ntohs(ep->ether_type);
170 
171 		extracted_ethertype = 0;
172 		if (ether_type <= ETHERMTU) {
173 			/* Try to print the LLC-layer header & higher layers */
174 			if (llc_print(p, length, caplen, ESRC(ep),
175 			    EDST(ep)) == 0) {
176 				/* ether_type not known, print raw packet */
177 				if (!eflag)
178 					ether_print((u_char *)ep, length);
179 				if (extracted_ethertype) {
180 					printf("(LLC %s) ",
181 					       etherproto_string(htons(extracted_ethertype)));
182 				}
183 				if (!xflag && !qflag)
184 					default_print(p, caplen);
185 			}
186 		} else if (ether_encap_print(ether_type, p, length,
187 		           caplen) == 0) {
188 			/* ether_type not known, print raw packet */
189 			if (!eflag)
190 				ether_print((u_char *)ep, length +
191 				    sizeof(*ep));
192 			if (!xflag && !qflag)
193 				default_print(p, caplen);
194 		}
195 		break;
196 #endif /* __OpenBSD__ */
197 	}
198 
199 	if (xflag)
200 		default_print((const u_char *)(packetp + NULL_HDRLEN),
201 		    caplen - NULL_HDRLEN);
202  out:
203 	putchar('\n');
204 }
205 
206