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#include <sys/cdefs.h>
24#ifndef lint
25__RCSID("$NetBSD: print-cip.c,v 1.7 2023/08/17 20:19:40 christos Exp $");
26#endif
27
28/* \summary: Linux Classical IP over ATM printer */
29
30#ifdef HAVE_CONFIG_H
31#include <config.h>
32#endif
33
34#include <string.h>
35
36#include "netdissect-stdinc.h"
37
38#define ND_LONGJMP_FROM_TCHECK
39#include "netdissect.h"
40#include "addrtoname.h"
41
42static const unsigned char rfcllc[] = {
43	0xaa,	/* DSAP: non-ISO */
44	0xaa,	/* SSAP: non-ISO */
45	0x03,	/* Ctrl: Unnumbered Information Command PDU */
46	0x00,	/* OUI: EtherType */
47	0x00,
48	0x00 };
49
50/*
51 * This is the top level routine of the printer.  'p' points
52 * to the LLC/SNAP or raw header of the packet, 'h->ts' is the timestamp,
53 * 'h->len' is the length of the packet off the wire, and 'h->caplen'
54 * is the number of bytes actually captured.
55 */
56void
57cip_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, const u_char *p)
58{
59	u_int caplen = h->caplen;
60	u_int length = h->len;
61	int llc_hdrlen;
62
63	ndo->ndo_protocol = "cip";
64
65	if (ndo->ndo_eflag)
66		/*
67		 * There is no MAC-layer header, so just print the length.
68		 */
69		ND_PRINT("%u: ", length);
70
71	ND_TCHECK_LEN(p, sizeof(rfcllc));
72	if (memcmp(rfcllc, p, sizeof(rfcllc)) == 0) {
73		/*
74		 * LLC header is present.  Try to print it & higher layers.
75		 */
76		llc_hdrlen = llc_print(ndo, p, length, caplen, NULL, NULL);
77		if (llc_hdrlen < 0) {
78			/* packet type not known, print raw packet */
79			if (!ndo->ndo_suppress_default_print)
80				ND_DEFAULTPRINT(p, caplen);
81			llc_hdrlen = -llc_hdrlen;
82		}
83	} else {
84		/*
85		 * LLC header is absent; treat it as just IP.
86		 */
87		llc_hdrlen = 0;
88		ip_print(ndo, p, length);
89	}
90
91	ndo->ndo_ll_hdr_len += llc_hdrlen;
92}
93