print-cip.c revision 56893 
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 1.2 1999/11/21 09:36:49 fenner 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#include <net/if.h>
38
39#include <netinet/in.h>
40#include <netinet/if_ether.h>
41#include <netinet/in_systm.h>
42#include <netinet/ip.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 <stdio.h>
50#include <pcap.h>
51
52#include "interface.h"
53#include "addrtoname.h"
54
55const u_char *packetp;
56const u_char *snapend;
57
58#define RFC1483LLC_LEN 8
59
60static unsigned char rfcllc[] = {
61  0xaa,   /* DSAP: non-ISO */
62  0xaa,   /* SSAP: non-ISO */
63  0x03,   /* Ctrl: Unnumbered Information Command PDU */
64  0x00,   /* OUI: EtherType */
65  0x00,
66  0x00 };
67
68static inline void
69cip_print(register const u_char *bp, int length)
70{
71  int i;
72
73  if (memcmp(rfcllc, bp, sizeof(rfcllc))) {
74    if (qflag) {
75      for(i=0;i<RFC1483LLC_LEN;i++)
76	(void)printf("%2.2x ",bp[i]);
77    } else {
78      for(i=0;i<RFC1483LLC_LEN-2;i++)
79	(void)printf("%2.2x ",bp[i]);
80      etherproto_string(((u_short*)bp)[3]);
81    }
82  } else {
83    if (qflag)
84      (void)printf("(null encapsulation)");
85    else {
86      (void)printf("(null encap)");
87      etherproto_string(ETHERTYPE_IP);
88    }
89  }
90}
91
92/*
93 * This is the top level routine of the printer.  'p' is the points
94 * to the raw header of the packet, 'tvp' is the timestamp,
95 * 'length' is the length of the packet off the wire, and 'caplen'
96 * is the number of bytes actually captured.
97 */
98void
99cip_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
100{
101	int caplen = h->caplen;
102	int length = h->len;
103	u_short ether_type;
104	u_short extracted_ethertype;
105	u_short *bp;
106
107	ts_print(&h->ts);
108
109	if (memcmp(rfcllc, p, sizeof(rfcllc))==0 && caplen < RFC1483LLC_LEN) {
110		printf("[|cip]");
111		goto out;
112	}
113
114	if (eflag)
115	  cip_print(p, length);
116
117	/*
118	 * Some printers want to get back at the ethernet addresses,
119	 * and/or check that they're not walking off the end of the packet.
120	 * Rather than pass them all the way down, we set these globals.
121	 */
122	packetp = p;
123	snapend = p + caplen;
124
125	if (memcmp(rfcllc, p, sizeof(rfcllc))==0) {
126	  length -= RFC1483LLC_LEN;
127	  caplen -= RFC1483LLC_LEN;
128	  bp = (u_short*)p;
129	  p += RFC1483LLC_LEN;
130	  ether_type = ntohs(bp[3]);
131	} else
132	  ether_type = ETHERTYPE_IP;
133
134	/*
135	 * Is it (gag) an 802.3 encapsulation?
136	 */
137	extracted_ethertype = 0;
138	if (ether_type < ETHERMTU) {
139		/* Try to print the LLC-layer header & higher layers */
140		if (llc_print(p, length, caplen, NULL, NULL)==0) {
141			/* ether_type not known, print raw packet */
142			if (!eflag)
143				cip_print((u_char *)bp, length);
144			if (extracted_ethertype) {
145				printf("(LLC %s) ",
146			       etherproto_string(htons(extracted_ethertype)));
147			}
148			if (!xflag && !qflag)
149				default_print(p, caplen);
150		}
151	} else if (ether_encap_print(ether_type, p, length, caplen) == 0) {
152		/* ether_type not known, print raw packet */
153		if (!eflag)
154			cip_print((u_char *)bp, length + RFC1483LLC_LEN);
155		if (!xflag && !qflag)
156			default_print(p, caplen);
157	}
158	if (xflag)
159		default_print(p, caplen);
160 out:
161	putchar('\n');
162}
163