xref: /openbsd-src/usr.sbin/tcpdump/print-sl.c (revision 50b7afb2c2c0993b0894d4e34bf857cb13ed9c80)
1 /*	$OpenBSD: print-sl.c,v 1.15 2013/12/03 00:21:21 deraadt Exp $	*/
2 
3 /*
4  * Copyright (c) 1989, 1990, 1991, 1993, 1994, 1995, 1996, 1997
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that: (1) source code distributions
9  * retain the above copyright notice and this paragraph in its entirety, (2)
10  * distributions including binary code include the above copyright notice and
11  * this paragraph in its entirety in the documentation or other materials
12  * provided with the distribution, and (3) all advertising materials mentioning
13  * features or use of this software display the following acknowledgement:
14  * ``This product includes software developed by the University of California,
15  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
16  * the University nor the names of its contributors may be used to endorse
17  * or promote products derived from this software without specific prior
18  * written permission.
19  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
20  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
21  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
22  */
23 
24 #ifdef HAVE_NET_SLIP_H
25 #include <sys/param.h>
26 #include <sys/time.h>
27 #include <sys/file.h>
28 #include <sys/ioctl.h>
29 #include <sys/mbuf.h>
30 #include <sys/socket.h>
31 
32 struct rtentry;
33 #include <net/if.h>
34 
35 #include <netinet/in.h>
36 #include <netinet/in_systm.h>
37 #include <netinet/ip.h>
38 #include <netinet/if_ether.h>
39 #include <netinet/udp.h>
40 #include <netinet/tcp.h>
41 
42 #include <net/slcompress.h>
43 #include <net/slip.h>
44 
45 #include <ctype.h>
46 #include <netdb.h>
47 #include <pcap.h>
48 #include <stdio.h>
49 
50 #include "interface.h"
51 #include "addrtoname.h"
52 #include "extract.h"			/* must come after interface.h */
53 
54 static u_int lastlen[2][256];
55 static u_int lastconn = 255;
56 
57 static void sliplink_print(const u_char *, const struct ip *, u_int);
58 static void compressed_sl_print(const u_char *, const struct ip *, u_int, int);
59 
60 /* XXX BSD/OS 2.1 compatibility */
61 #if !defined(SLIP_HDRLEN) && defined(SLC_BPFHDR)
62 #define SLIP_HDRLEN SLC_BPFHDR
63 #define SLX_DIR 0
64 #define SLX_CHDR (SLC_BPFHDRLEN - 1)
65 #define CHDR_LEN (SLC_BPFHDR - SLC_BPFHDRLEN)
66 #endif
67 
68 /* XXX needs more hacking to work right */
69 
70 void
71 sl_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
72 {
73 	register u_int caplen = h->caplen;
74 	register u_int length = h->len;
75 	register const struct ip *ip;
76 
77 	ts_print(&h->ts);
78 
79 	if (caplen < SLIP_HDRLEN) {
80 		printf("[|slip]");
81 		goto out;
82 	}
83 	/*
84 	 * Some printers want to get back at the link level addresses,
85 	 * and/or check that they're not walking off the end of the packet.
86 	 * Rather than pass them all the way down, we set these globals.
87 	 */
88 	packetp = p;
89 	snapend = p + caplen;
90 
91 	length -= SLIP_HDRLEN;
92 
93 	ip = (struct ip *)(p + SLIP_HDRLEN);
94 
95 	if (eflag)
96 		sliplink_print(p, ip, length);
97 
98 	switch (ip->ip_v) {
99 	case 4:
100 		ip_print((u_char *)ip, length);
101 		break;
102 #ifdef INET6
103 	case 6:
104 		ip6_print((u_char *)ip, length);
105 		break;
106 #endif
107 	default:
108 		printf ("ip v%d", ip->ip_v);
109 	}
110 
111 	if (xflag)
112 		default_print((u_char *)ip, caplen - SLIP_HDRLEN);
113  out:
114 	putchar('\n');
115 }
116 
117 
118 void
119 sl_bsdos_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
120 {
121 	register u_int caplen = h->caplen;
122 	register u_int length = h->len;
123 	register const struct ip *ip;
124 
125 	ts_print(&h->ts);
126 
127 	if (caplen < SLIP_HDRLEN) {
128 		printf("[|slip]");
129 		goto out;
130 	}
131 	/*
132 	 * Some printers want to get back at the link level addresses,
133 	 * and/or check that they're not walking off the end of the packet.
134 	 * Rather than pass them all the way down, we set these globals.
135 	 */
136 	packetp = p;
137 	snapend = p + caplen;
138 
139 	length -= SLIP_HDRLEN;
140 
141 	ip = (struct ip *)(p + SLIP_HDRLEN);
142 
143 #ifdef notdef
144 	if (eflag)
145 		sliplink_print(p, ip, length);
146 #endif
147 
148 	ip_print((u_char *)ip, length);
149 
150 	if (xflag)
151 		default_print((u_char *)ip, caplen - SLIP_HDRLEN);
152  out:
153 	putchar('\n');
154 }
155 
156 static void
157 sliplink_print(register const u_char *p, register const struct ip *ip,
158 	       register u_int length)
159 {
160 	int dir;
161 	u_int hlen;
162 
163 	dir = p[SLX_DIR];
164 	putchar(dir == SLIPDIR_IN ? 'I' : 'O');
165 	putchar(' ');
166 
167 	if (nflag) {
168 		/* XXX just dump the header */
169 		register int i;
170 
171 		for (i = SLX_CHDR; i < SLX_CHDR + CHDR_LEN - 1; ++i)
172 			printf("%02x.", p[i]);
173 		printf("%02x: ", p[SLX_CHDR + CHDR_LEN - 1]);
174 		return;
175 	}
176 	switch (p[SLX_CHDR] & 0xf0) {
177 
178 	case TYPE_IP:
179 		printf("ip %d: ", length + SLIP_HDRLEN);
180 		break;
181 
182 	case TYPE_UNCOMPRESSED_TCP:
183 		/*
184 		 * The connection id is stored in the IP protocol field.
185 		 * Get it from the link layer since sl_uncompress_tcp()
186 		 * has restored the IP header copy to IPPROTO_TCP.
187 		 */
188 		lastconn = ((struct ip *)&p[SLX_CHDR])->ip_p;
189 		hlen = ip->ip_hl;
190 		hlen += ((struct tcphdr *)&((int *)ip)[hlen])->th_off;
191 		lastlen[dir][lastconn] = length - (hlen << 2);
192 		printf("utcp %d: ", lastconn);
193 		break;
194 
195 	default:
196 		if (p[SLX_CHDR] & TYPE_COMPRESSED_TCP) {
197 			compressed_sl_print(&p[SLX_CHDR], ip,
198 			    length, dir);
199 			printf(": ");
200 		} else
201 			printf("slip-%d!: ", p[SLX_CHDR]);
202 	}
203 }
204 
205 static const u_char *
206 print_sl_change(const char *str, register const u_char *cp)
207 {
208 	register u_int i;
209 
210 	if ((i = *cp++) == 0) {
211 		i = EXTRACT_16BITS(cp);
212 		cp += 2;
213 	}
214 	printf(" %s%d", str, i);
215 	return (cp);
216 }
217 
218 static const u_char *
219 print_sl_winchange(register const u_char *cp)
220 {
221 	register short i;
222 
223 	if ((i = *cp++) == 0) {
224 		i = EXTRACT_16BITS(cp);
225 		cp += 2;
226 	}
227 	if (i >= 0)
228 		printf(" W+%d", i);
229 	else
230 		printf(" W%d", i);
231 	return (cp);
232 }
233 
234 static void
235 compressed_sl_print(const u_char *chdr, const struct ip *ip,
236 		    u_int length, int dir)
237 {
238 	register const u_char *cp = chdr;
239 	register u_int flags, hlen;
240 
241 	flags = *cp++;
242 	if (flags & NEW_C) {
243 		lastconn = *cp++;
244 		printf("ctcp %d", lastconn);
245 	} else
246 		printf("ctcp *");
247 
248 	/* skip tcp checksum */
249 	cp += 2;
250 
251 	switch (flags & SPECIALS_MASK) {
252 	case SPECIAL_I:
253 		printf(" *SA+%d", lastlen[dir][lastconn]);
254 		break;
255 
256 	case SPECIAL_D:
257 		printf(" *S+%d", lastlen[dir][lastconn]);
258 		break;
259 
260 	default:
261 		if (flags & NEW_U)
262 			cp = print_sl_change("U=", cp);
263 		if (flags & NEW_W)
264 			cp = print_sl_winchange(cp);
265 		if (flags & NEW_A)
266 			cp = print_sl_change("A+", cp);
267 		if (flags & NEW_S)
268 			cp = print_sl_change("S+", cp);
269 		break;
270 	}
271 	if (flags & NEW_I)
272 		cp = print_sl_change("I+", cp);
273 
274 	/*
275 	 * 'hlen' is the length of the uncompressed TCP/IP header (in words).
276 	 * 'cp - chdr' is the length of the compressed header.
277 	 * 'length - hlen' is the amount of data in the packet.
278 	 */
279 	hlen = ip->ip_hl;
280 	hlen += ((struct tcphdr *)&((int32_t *)ip)[hlen])->th_off;
281 	lastlen[dir][lastconn] = length - (hlen << 2);
282 	printf(" %d (%d)", lastlen[dir][lastconn], (int)(cp - chdr));
283 }
284 #else
285 #include <sys/types.h>
286 #include <sys/time.h>
287 
288 #include <pcap.h>
289 #include <stdio.h>
290 
291 #include "interface.h"
292 
293 void
294 sl_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
295 {
296 
297 	error("not configured for slip");
298 	/* NOTREACHED */
299 }
300 
301 void
302 sl_bsdos_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
303 {
304 
305 	error("not configured for slip");
306 	/* NOTREACHED */
307 }
308 #endif
309