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/* \summary: Linux Classical IP over ATM printer */
24
25#ifdef HAVE_CONFIG_H
26#include <config.h>
27#endif
28
29#include <string.h>
30
31#include "netdissect-stdinc.h"
32
33#define ND_LONGJMP_FROM_TCHECK
34#include "netdissect.h"
35#include "addrtoname.h"
36
37static const unsigned char rfcllc[] = {
38	0xaa,	/* DSAP: non-ISO */
39	0xaa,	/* SSAP: non-ISO */
40	0x03,	/* Ctrl: Unnumbered Information Command PDU */
41	0x00,	/* OUI: EtherType */
42	0x00,
43	0x00 };
44
45/*
46 * This is the top level routine of the printer.  'p' points
47 * to the LLC/SNAP or raw header of the packet, 'h->ts' is the timestamp,
48 * 'h->len' is the length of the packet off the wire, and 'h->caplen'
49 * is the number of bytes actually captured.
50 */
51void
52cip_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, const u_char *p)
53{
54	u_int caplen = h->caplen;
55	u_int length = h->len;
56	int llc_hdrlen;
57
58	ndo->ndo_protocol = "cip";
59
60	if (ndo->ndo_eflag)
61		/*
62		 * There is no MAC-layer header, so just print the length.
63		 */
64		ND_PRINT("%u: ", length);
65
66	ND_TCHECK_LEN(p, sizeof(rfcllc));
67	if (memcmp(rfcllc, p, sizeof(rfcllc)) == 0) {
68		/*
69		 * LLC header is present.  Try to print it & higher layers.
70		 */
71		llc_hdrlen = llc_print(ndo, p, length, caplen, NULL, NULL);
72		if (llc_hdrlen < 0) {
73			/* packet type not known, print raw packet */
74			if (!ndo->ndo_suppress_default_print)
75				ND_DEFAULTPRINT(p, caplen);
76			llc_hdrlen = -llc_hdrlen;
77		}
78	} else {
79		/*
80		 * LLC header is absent; treat it as just IP.
81		 */
82		llc_hdrlen = 0;
83		ip_print(ndo, p, length);
84	}
85
86	ndo->ndo_ll_hdr_len += llc_hdrlen;
87}
88