xref: /freebsd/contrib/tcpdump/print-cip.c (revision 09e8dea79366f1e5b3a73e8a271b26e4b6bf2e6a)
1 /*
2  * Marko Kiiskila carnil@cs.tut.fi
3  *
4  * Tampere University of Technology - Telecommunications Laboratory
5  *
6  * Permission to use, copy, modify and distribute this
7  * software and its documentation is hereby granted,
8  * provided that both the copyright notice and this
9  * permission notice appear in all copies of the software,
10  * derivative works or modified versions, and any portions
11  * thereof, that both notices appear in supporting
12  * documentation, and that the use of this software is
13  * acknowledged in any publications resulting from using
14  * the software.
15  *
16  * TUT ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
17  * CONDITION AND DISCLAIMS ANY LIABILITY OF ANY KIND FOR
18  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS
19  * SOFTWARE.
20  *
21  */
22 
23 #ifndef lint
24 static const char rcsid[] =
25     "@(#) $Header: /tcpdump/master/tcpdump/print-cip.c,v 1.16 2001/09/23 21:52:38 guy Exp $ (LBL)";
26 #endif
27 
28 #ifdef HAVE_CONFIG_H
29 #include "config.h"
30 #endif
31 
32 #include <string.h>
33 
34 #include <sys/param.h>
35 #include <sys/time.h>
36 #include <sys/types.h>
37 #include <sys/socket.h>
38 
39 
40 #include <netinet/in.h>
41 
42 #include <stdio.h>
43 #include <pcap.h>
44 
45 #include "interface.h"
46 #include "addrtoname.h"
47 #include "ethertype.h"
48 #include "ether.h"
49 
50 #define RFC1483LLC_LEN	8
51 
52 static unsigned char rfcllc[] = {
53 	0xaa,	/* DSAP: non-ISO */
54 	0xaa,	/* SSAP: non-ISO */
55 	0x03,	/* Ctrl: Unnumbered Information Command PDU */
56 	0x00,	/* OUI: EtherType */
57 	0x00,
58 	0x00 };
59 
60 static inline void
61 cip_print(register const u_char *bp, int length)
62 {
63 	/*
64 	 * There is no MAC-layer header, so just print the length.
65 	 */
66 	printf("%d: ", length);
67 }
68 
69 /*
70  * This is the top level routine of the printer.  'p' is the points
71  * to the raw header of the packet, 'tvp' is the timestamp,
72  * 'length' is the length of the packet off the wire, and 'caplen'
73  * is the number of bytes actually captured.
74  */
75 void
76 cip_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
77 {
78 	u_int caplen = h->caplen;
79 	u_int length = h->len;
80 	u_short extracted_ethertype;
81 
82 	++infodelay;
83 	ts_print(&h->ts);
84 
85 	if (memcmp(rfcllc, p, sizeof(rfcllc))==0 && caplen < RFC1483LLC_LEN) {
86 		printf("[|cip]");
87 		goto out;
88 	}
89 
90 	if (eflag)
91 		cip_print(p, length);
92 
93 	/*
94 	 * Some printers want to get back at the ethernet addresses,
95 	 * and/or check that they're not walking off the end of the packet.
96 	 * Rather than pass them all the way down, we set these globals.
97 	 */
98 	packetp = p;
99 	snapend = p + caplen;
100 
101 	if (memcmp(rfcllc, p, sizeof(rfcllc)) == 0) {
102 		/*
103 		 * LLC header is present.  Try to print it & higher layers.
104 		 */
105 		if (llc_print(p, length, caplen, NULL, NULL,
106 		    &extracted_ethertype) == 0) {
107 			/* ether_type not known, print raw packet */
108 			if (!eflag)
109 				cip_print(p, length);
110 			if (extracted_ethertype) {
111 				printf("(LLC %s) ",
112 			       etherproto_string(htons(extracted_ethertype)));
113 			}
114 			if (!xflag && !qflag)
115 				default_print(p, caplen);
116 		}
117 	} else {
118 		/*
119 		 * LLC header is absent; treat it as just IP.
120 		 */
121 		ip_print(p, length);
122 	}
123 
124 	if (xflag)
125 		default_print(p, caplen);
126  out:
127 	putchar('\n');
128 	--infodelay;
129 	if (infoprint)
130 		info(0);
131 }
132