print-cip.c revision 75115 
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
24static const char rcsid[] =
25    "@(#) $Header: /tcpdump/master/tcpdump/print-cip.c,v 1.11 2000/12/22 22:45:10 guy Exp $ (LBL)";
26#endif
27
28#ifdef HAVE_CONFIG_H
29#include "config.h"
30#endif
31
32#include <sys/param.h>
33#include <sys/time.h>
34#include <sys/types.h>
35#include <sys/socket.h>
36
37
38#include <netinet/in.h>
39
40#include <stdio.h>
41#include <pcap.h>
42
43#include "interface.h"
44#include "addrtoname.h"
45#include "ethertype.h"
46#include "ether.h"
47
48const u_char *packetp;
49const u_char *snapend;
50
51#define RFC1483LLC_LEN	8
52
53static unsigned char rfcllc[] = {
54	0xaa,	/* DSAP: non-ISO */
55	0xaa,	/* SSAP: non-ISO */
56	0x03,	/* Ctrl: Unnumbered Information Command PDU */
57	0x00,	/* OUI: EtherType */
58	0x00,
59	0x00 };
60
61static inline void
62cip_print(register const u_char *bp, int length)
63{
64	int i;
65
66	if (memcmp(rfcllc, bp, sizeof(rfcllc))) {
67		if (qflag) {
68			for (i = 0;i < RFC1483LLC_LEN; i++)
69			(void)printf("%2.2x ",bp[i]);
70		} else {
71			for (i = 0;i < RFC1483LLC_LEN - 2; i++)
72				(void)printf("%2.2x ",bp[i]);
73			etherproto_string(((u_short*)bp)[3]);
74		}
75	} else {
76		if (qflag)
77			(void)printf("(null encapsulation)");
78		else {
79			(void)printf("(null encap)");
80			etherproto_string(ETHERTYPE_IP);
81		}
82	}
83}
84
85/*
86 * This is the top level routine of the printer.  'p' is the points
87 * to the raw header of the packet, 'tvp' is the timestamp,
88 * 'length' is the length of the packet off the wire, and 'caplen'
89 * is the number of bytes actually captured.
90 */
91void
92cip_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
93{
94	int caplen = h->caplen;
95	int length = h->len;
96	u_short ether_type;
97	u_short extracted_ethertype;
98	u_short *bp;
99
100	ts_print(&h->ts);
101
102	if (memcmp(rfcllc, p, sizeof(rfcllc))==0 && caplen < RFC1483LLC_LEN) {
103		printf("[|cip]");
104		goto out;
105	}
106
107	if (eflag)
108		cip_print(p, length);
109
110	/*
111	 * Some printers want to get back at the ethernet addresses,
112	 * and/or check that they're not walking off the end of the packet.
113	 * Rather than pass them all the way down, we set these globals.
114	 */
115	packetp = p;
116	snapend = p + caplen;
117
118	if (memcmp(rfcllc, p, sizeof(rfcllc))==0) {
119		length -= RFC1483LLC_LEN;
120		caplen -= RFC1483LLC_LEN;
121		bp = (u_short *)p;
122		p += RFC1483LLC_LEN;
123		ether_type = ntohs(bp[3]);
124	} else {
125		ether_type = ETHERTYPE_IP;
126		bp = (u_short *)p;
127	}
128
129	/*
130	 * Is it (gag) an 802.3 encapsulation?
131	 */
132	extracted_ethertype = 0;
133	if (ether_type < ETHERMTU) {
134		/* Try to print the LLC-layer header & higher layers */
135		if (llc_print(p, length, caplen, NULL, NULL,
136		    &extracted_ethertype)==0) {
137			/* ether_type not known, print raw packet */
138			if (!eflag)
139				cip_print((u_char *)bp, length + RFC1483LLC_LEN);
140			if (extracted_ethertype) {
141				printf("(LLC %s) ",
142			       etherproto_string(htons(extracted_ethertype)));
143			}
144			if (!xflag && !qflag)
145				default_print(p, caplen);
146		}
147	} else if (ether_encap_print(ether_type, p, length, caplen,
148	    &extracted_ethertype) == 0) {
149		/* ether_type not known, print raw packet */
150		if (!eflag)
151			cip_print((u_char *)bp, length + RFC1483LLC_LEN);
152		if (!xflag && !qflag)
153			default_print(p, caplen);
154	}
155	if (xflag)
156		default_print(p, caplen);
157 out:
158	putchar('\n');
159}
160