xref: /openbsd-src/usr.sbin/tcpdump/print-sl.c (revision f2da64fbbbf1b03f09f390ab01267c93dfd77c4c)
1 /*	$OpenBSD: print-sl.c,v 1.19 2015/11/16 00:16:39 mmcc 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/time.h>
26 #include <sys/file.h>
27 #include <sys/ioctl.h>
28 #include <sys/socket.h>
29 
30 struct rtentry;
31 #include <net/if.h>
32 
33 #include <netinet/in.h>
34 #include <netinet/ip.h>
35 #include <netinet/if_ether.h>
36 #include <netinet/udp.h>
37 #include <netinet/tcp.h>
38 
39 #include <net/slcompress.h>
40 #include <net/slip.h>
41 
42 #include <ctype.h>
43 #include <netdb.h>
44 #include <pcap.h>
45 #include <stdio.h>
46 #include <limits.h>
47 
48 #include "interface.h"
49 #include "addrtoname.h"
50 #include "extract.h"			/* must come after interface.h */
51 
52 static u_int lastlen[2][256];
53 static u_int lastconn = 255;
54 
55 static void sliplink_print(const u_char *, const struct ip *, u_int);
56 static void compressed_sl_print(const u_char *, const struct ip *, u_int, int);
57 
58 /* XXX BSD/OS 2.1 compatibility */
59 #if !defined(SLIP_HDRLEN) && defined(SLC_BPFHDR)
60 #define SLIP_HDRLEN SLC_BPFHDR
61 #define SLX_DIR 0
62 #define SLX_CHDR (SLC_BPFHDRLEN - 1)
63 #define CHDR_LEN (SLC_BPFHDR - SLC_BPFHDRLEN)
64 #endif
65 
66 /* XXX needs more hacking to work right */
67 
68 void
69 sl_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
70 {
71 	u_int caplen = h->caplen;
72 	u_int length = h->len;
73 	const struct ip *ip;
74 
75 	ts_print(&h->ts);
76 
77 	if (caplen < SLIP_HDRLEN || length < SLIP_HDRLEN) {
78 		printf("[|slip]");
79 		goto out;
80 	}
81 	/*
82 	 * Some printers want to get back at the link level addresses,
83 	 * and/or check that they're not walking off the end of the packet.
84 	 * Rather than pass them all the way down, we set these globals.
85 	 */
86 	packetp = p;
87 	snapend = p + caplen;
88 
89 	length -= SLIP_HDRLEN;
90 
91 	ip = (struct ip *)(p + SLIP_HDRLEN);
92 
93 	if (eflag)
94 		sliplink_print(p, ip, length);
95 
96 	switch (ip->ip_v) {
97 	case 4:
98 		ip_print((u_char *)ip, length);
99 		break;
100 #ifdef INET6
101 	case 6:
102 		ip6_print((u_char *)ip, length);
103 		break;
104 #endif
105 	default:
106 		printf ("ip v%d", ip->ip_v);
107 	}
108 
109 	if (xflag)
110 		default_print((u_char *)ip, caplen - SLIP_HDRLEN);
111  out:
112 	putchar('\n');
113 }
114 
115 
116 void
117 sl_bsdos_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
118 {
119 	u_int caplen = h->caplen;
120 	u_int length = h->len;
121 	const struct ip *ip;
122 
123 	ts_print(&h->ts);
124 
125 	if (caplen < SLIP_HDRLEN) {
126 		printf("[|slip]");
127 		goto out;
128 	}
129 	/*
130 	 * Some printers want to get back at the link level addresses,
131 	 * and/or check that they're not walking off the end of the packet.
132 	 * Rather than pass them all the way down, we set these globals.
133 	 */
134 	packetp = p;
135 	snapend = p + caplen;
136 
137 	length -= SLIP_HDRLEN;
138 
139 	ip = (struct ip *)(p + SLIP_HDRLEN);
140 
141 #ifdef notdef
142 	if (eflag)
143 		sliplink_print(p, ip, length);
144 #endif
145 
146 	ip_print((u_char *)ip, length);
147 
148 	if (xflag)
149 		default_print((u_char *)ip, caplen - SLIP_HDRLEN);
150  out:
151 	putchar('\n');
152 }
153 
154 static void
155 sliplink_print(const u_char *p, const struct ip *ip, u_int length)
156 {
157 	int dir;
158 	u_int hlen;
159 
160 	dir = p[SLX_DIR];
161 	putchar(dir == SLIPDIR_IN ? 'I' : 'O');
162 	putchar(' ');
163 
164 	if (nflag) {
165 		/* XXX just dump the header */
166 		int i;
167 
168 		for (i = SLX_CHDR; i < SLX_CHDR + CHDR_LEN - 1; ++i)
169 			printf("%02x.", p[i]);
170 		printf("%02x: ", p[SLX_CHDR + CHDR_LEN - 1]);
171 		return;
172 	}
173 	switch (p[SLX_CHDR] & 0xf0) {
174 
175 	case TYPE_IP:
176 		printf("ip %d: ", length + SLIP_HDRLEN);
177 		break;
178 
179 	case TYPE_UNCOMPRESSED_TCP:
180 		/*
181 		 * The connection id is stored in the IP protocol field.
182 		 * Get it from the link layer since sl_uncompress_tcp()
183 		 * has restored the IP header copy to IPPROTO_TCP.
184 		 */
185 		lastconn = ((struct ip *)&p[SLX_CHDR])->ip_p;
186 		hlen = ip->ip_hl;
187 		hlen += ((struct tcphdr *)&((int *)ip)[hlen])->th_off;
188 		lastlen[dir][lastconn] = length - (hlen << 2);
189 		printf("utcp %d: ", lastconn);
190 		break;
191 
192 	default:
193 		if (p[SLX_CHDR] & TYPE_COMPRESSED_TCP) {
194 			compressed_sl_print(&p[SLX_CHDR], ip,
195 			    length, dir);
196 			printf(": ");
197 		} else
198 			printf("slip-%d!: ", p[SLX_CHDR]);
199 	}
200 }
201 
202 static const u_char *
203 print_sl_change(const char *str, const u_char *cp)
204 {
205 	u_int i;
206 
207 	if ((i = *cp++) == 0) {
208 		i = EXTRACT_16BITS(cp);
209 		cp += 2;
210 	}
211 	printf(" %s%d", str, i);
212 	return (cp);
213 }
214 
215 static const u_char *
216 print_sl_winchange(const u_char *cp)
217 {
218 	short i;
219 
220 	if ((i = *cp++) == 0) {
221 		i = EXTRACT_16BITS(cp);
222 		cp += 2;
223 	}
224 	if (i >= 0)
225 		printf(" W+%d", i);
226 	else
227 		printf(" W%d", i);
228 	return (cp);
229 }
230 
231 static void
232 compressed_sl_print(const u_char *chdr, const struct ip *ip,
233 		    u_int length, int dir)
234 {
235 	const u_char *cp = chdr;
236 	u_int flags, hlen;
237 
238 	flags = *cp++;
239 	if (flags & NEW_C) {
240 		lastconn = *cp++;
241 		printf("ctcp %d", lastconn);
242 	} else
243 		printf("ctcp *");
244 
245 	/* skip tcp checksum */
246 	cp += 2;
247 
248 	switch (flags & SPECIALS_MASK) {
249 	case SPECIAL_I:
250 		printf(" *SA+%d", lastlen[dir][lastconn]);
251 		break;
252 
253 	case SPECIAL_D:
254 		printf(" *S+%d", lastlen[dir][lastconn]);
255 		break;
256 
257 	default:
258 		if (flags & NEW_U)
259 			cp = print_sl_change("U=", cp);
260 		if (flags & NEW_W)
261 			cp = print_sl_winchange(cp);
262 		if (flags & NEW_A)
263 			cp = print_sl_change("A+", cp);
264 		if (flags & NEW_S)
265 			cp = print_sl_change("S+", cp);
266 		break;
267 	}
268 	if (flags & NEW_I)
269 		cp = print_sl_change("I+", cp);
270 
271 	/*
272 	 * 'hlen' is the length of the uncompressed TCP/IP header (in words).
273 	 * 'cp - chdr' is the length of the compressed header.
274 	 * 'length - hlen' is the amount of data in the packet.
275 	 */
276 	hlen = ip->ip_hl;
277 	hlen += ((struct tcphdr *)&((int32_t *)ip)[hlen])->th_off;
278 	lastlen[dir][lastconn] = length - (hlen << 2);
279 	printf(" %d (%d)", lastlen[dir][lastconn], (int)(cp - chdr));
280 }
281 #else
282 #include <sys/types.h>
283 #include <sys/time.h>
284 
285 #include <pcap.h>
286 #include <stdio.h>
287 
288 #include "interface.h"
289 
290 void
291 sl_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
292 {
293 
294 	error("not configured for slip");
295 	/* NOTREACHED */
296 }
297 
298 void
299 sl_bsdos_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
300 {
301 
302 	error("not configured for slip");
303 	/* NOTREACHED */
304 }
305 #endif
306