xref: /freebsd/contrib/tcpdump/print-null.c (revision 4cf49a43559ed9fdad601bdcccd2c55963008675)
1 /*
2  * Copyright (c) 1991, 1993, 1994, 1995, 1996, 1997
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 
22 #ifndef lint
23 static const char rcsid[] =
24     "@(#) $Header: print-null.c,v 1.24 97/05/28 12:52:47 leres Exp $ (LBL)";
25 #endif
26 
27 #include <sys/param.h>
28 #include <sys/time.h>
29 #include <sys/socket.h>
30 #include <sys/file.h>
31 #include <sys/ioctl.h>
32 
33 #if __STDC__
34 struct mbuf;
35 struct rtentry;
36 #endif
37 #include <net/if.h>
38 
39 #include <netinet/in.h>
40 #include <netinet/in_systm.h>
41 #include <netinet/ip.h>
42 #include <net/ethernet.h>
43 #include <netinet/ip_var.h>
44 #include <netinet/udp.h>
45 #include <netinet/udp_var.h>
46 #include <netinet/tcp.h>
47 #include <netinet/tcpip.h>
48 
49 #include <pcap.h>
50 #include <stdio.h>
51 #include <string.h>
52 
53 #include "interface.h"
54 #include "addrtoname.h"
55 
56 #ifndef AF_NS
57 #define AF_NS		6		/* XEROX NS protocols */
58 #endif
59 
60 /*
61  * The DLT_NULL packet header is 4 bytes long. It contains a network
62  * order 32 bit integer that specifies the family, e.g. AF_INET
63  */
64 #define	NULL_HDRLEN 4
65 
66 static void
67 null_print(const u_char *p, const struct ip *ip, u_int length)
68 {
69 	u_int family;
70 
71 	memcpy((char *)&family, (char *)p, sizeof(family));
72 
73 	if (nflag) {
74 		/* XXX just dump the header */
75 		return;
76 	}
77 	switch (family) {
78 
79 	case AF_INET:
80 		printf("ip: ");
81 		break;
82 
83 	case AF_NS:
84 		printf("ns: ");
85 		break;
86 
87 	default:
88 		printf("AF %d: ", family);
89 		break;
90 	}
91 }
92 
93 void
94 null_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
95 {
96 	u_int length = h->len;
97 	u_int caplen = h->caplen;
98 	const struct ip *ip;
99 
100 	ts_print(&h->ts);
101 
102 	/*
103 	 * Some printers want to get back at the link level addresses,
104 	 * and/or check that they're not walking off the end of the packet.
105 	 * Rather than pass them all the way down, we set these globals.
106 	 */
107 	packetp = p;
108 	snapend = p + caplen;
109 
110 	length -= NULL_HDRLEN;
111 
112 	ip = (struct ip *)(p + NULL_HDRLEN);
113 
114 	if (eflag)
115 		null_print(p, ip, length);
116 
117 	ip_print((const u_char *)ip, length);
118 
119 	if (xflag)
120 		default_print((const u_char *)ip, caplen - NULL_HDRLEN);
121 	putchar('\n');
122 }
123 
124