xref: /openbsd-src/usr.sbin/tcpdump/print-sl.c (revision 6f05df2d9be0954bec42d51d943d77bd250fb664)
1 /*	$OpenBSD: print-sl.c,v 1.17 2014/11/20 04:01:01 jsg 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/ip.h>
37 #include <netinet/if_ether.h>
38 #include <netinet/udp.h>
39 #include <netinet/tcp.h>
40 
41 #include <net/slcompress.h>
42 #include <net/slip.h>
43 
44 #include <ctype.h>
45 #include <netdb.h>
46 #include <pcap.h>
47 #include <stdio.h>
48 
49 #include "interface.h"
50 #include "addrtoname.h"
51 #include "extract.h"			/* must come after interface.h */
52 
53 static u_int lastlen[2][256];
54 static u_int lastconn = 255;
55 
56 static void sliplink_print(const u_char *, const struct ip *, u_int);
57 static void compressed_sl_print(const u_char *, const struct ip *, u_int, int);
58 
59 /* XXX BSD/OS 2.1 compatibility */
60 #if !defined(SLIP_HDRLEN) && defined(SLC_BPFHDR)
61 #define SLIP_HDRLEN SLC_BPFHDR
62 #define SLX_DIR 0
63 #define SLX_CHDR (SLC_BPFHDRLEN - 1)
64 #define CHDR_LEN (SLC_BPFHDR - SLC_BPFHDRLEN)
65 #endif
66 
67 /* XXX needs more hacking to work right */
68 
69 void
70 sl_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
71 {
72 	register u_int caplen = h->caplen;
73 	register u_int length = h->len;
74 	register const struct ip *ip;
75 
76 	ts_print(&h->ts);
77 
78 	if (caplen < SLIP_HDRLEN || length < SLIP_HDRLEN) {
79 		printf("[|slip]");
80 		goto out;
81 	}
82 	/*
83 	 * Some printers want to get back at the link level addresses,
84 	 * and/or check that they're not walking off the end of the packet.
85 	 * Rather than pass them all the way down, we set these globals.
86 	 */
87 	packetp = p;
88 	snapend = p + caplen;
89 
90 	length -= SLIP_HDRLEN;
91 
92 	ip = (struct ip *)(p + SLIP_HDRLEN);
93 
94 	if (eflag)
95 		sliplink_print(p, ip, length);
96 
97 	switch (ip->ip_v) {
98 	case 4:
99 		ip_print((u_char *)ip, length);
100 		break;
101 #ifdef INET6
102 	case 6:
103 		ip6_print((u_char *)ip, length);
104 		break;
105 #endif
106 	default:
107 		printf ("ip v%d", ip->ip_v);
108 	}
109 
110 	if (xflag)
111 		default_print((u_char *)ip, caplen - SLIP_HDRLEN);
112  out:
113 	putchar('\n');
114 }
115 
116 
117 void
118 sl_bsdos_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
119 {
120 	register u_int caplen = h->caplen;
121 	register u_int length = h->len;
122 	register const struct ip *ip;
123 
124 	ts_print(&h->ts);
125 
126 	if (caplen < SLIP_HDRLEN) {
127 		printf("[|slip]");
128 		goto out;
129 	}
130 	/*
131 	 * Some printers want to get back at the link level addresses,
132 	 * and/or check that they're not walking off the end of the packet.
133 	 * Rather than pass them all the way down, we set these globals.
134 	 */
135 	packetp = p;
136 	snapend = p + caplen;
137 
138 	length -= SLIP_HDRLEN;
139 
140 	ip = (struct ip *)(p + SLIP_HDRLEN);
141 
142 #ifdef notdef
143 	if (eflag)
144 		sliplink_print(p, ip, length);
145 #endif
146 
147 	ip_print((u_char *)ip, length);
148 
149 	if (xflag)
150 		default_print((u_char *)ip, caplen - SLIP_HDRLEN);
151  out:
152 	putchar('\n');
153 }
154 
155 static void
156 sliplink_print(register const u_char *p, register const struct ip *ip,
157 	       register u_int length)
158 {
159 	int dir;
160 	u_int hlen;
161 
162 	dir = p[SLX_DIR];
163 	putchar(dir == SLIPDIR_IN ? 'I' : 'O');
164 	putchar(' ');
165 
166 	if (nflag) {
167 		/* XXX just dump the header */
168 		register int i;
169 
170 		for (i = SLX_CHDR; i < SLX_CHDR + CHDR_LEN - 1; ++i)
171 			printf("%02x.", p[i]);
172 		printf("%02x: ", p[SLX_CHDR + CHDR_LEN - 1]);
173 		return;
174 	}
175 	switch (p[SLX_CHDR] & 0xf0) {
176 
177 	case TYPE_IP:
178 		printf("ip %d: ", length + SLIP_HDRLEN);
179 		break;
180 
181 	case TYPE_UNCOMPRESSED_TCP:
182 		/*
183 		 * The connection id is stored in the IP protocol field.
184 		 * Get it from the link layer since sl_uncompress_tcp()
185 		 * has restored the IP header copy to IPPROTO_TCP.
186 		 */
187 		lastconn = ((struct ip *)&p[SLX_CHDR])->ip_p;
188 		hlen = ip->ip_hl;
189 		hlen += ((struct tcphdr *)&((int *)ip)[hlen])->th_off;
190 		lastlen[dir][lastconn] = length - (hlen << 2);
191 		printf("utcp %d: ", lastconn);
192 		break;
193 
194 	default:
195 		if (p[SLX_CHDR] & TYPE_COMPRESSED_TCP) {
196 			compressed_sl_print(&p[SLX_CHDR], ip,
197 			    length, dir);
198 			printf(": ");
199 		} else
200 			printf("slip-%d!: ", p[SLX_CHDR]);
201 	}
202 }
203 
204 static const u_char *
205 print_sl_change(const char *str, register const u_char *cp)
206 {
207 	register u_int i;
208 
209 	if ((i = *cp++) == 0) {
210 		i = EXTRACT_16BITS(cp);
211 		cp += 2;
212 	}
213 	printf(" %s%d", str, i);
214 	return (cp);
215 }
216 
217 static const u_char *
218 print_sl_winchange(register const u_char *cp)
219 {
220 	register short i;
221 
222 	if ((i = *cp++) == 0) {
223 		i = EXTRACT_16BITS(cp);
224 		cp += 2;
225 	}
226 	if (i >= 0)
227 		printf(" W+%d", i);
228 	else
229 		printf(" W%d", i);
230 	return (cp);
231 }
232 
233 static void
234 compressed_sl_print(const u_char *chdr, const struct ip *ip,
235 		    u_int length, int dir)
236 {
237 	register const u_char *cp = chdr;
238 	register u_int flags, hlen;
239 
240 	flags = *cp++;
241 	if (flags & NEW_C) {
242 		lastconn = *cp++;
243 		printf("ctcp %d", lastconn);
244 	} else
245 		printf("ctcp *");
246 
247 	/* skip tcp checksum */
248 	cp += 2;
249 
250 	switch (flags & SPECIALS_MASK) {
251 	case SPECIAL_I:
252 		printf(" *SA+%d", lastlen[dir][lastconn]);
253 		break;
254 
255 	case SPECIAL_D:
256 		printf(" *S+%d", lastlen[dir][lastconn]);
257 		break;
258 
259 	default:
260 		if (flags & NEW_U)
261 			cp = print_sl_change("U=", cp);
262 		if (flags & NEW_W)
263 			cp = print_sl_winchange(cp);
264 		if (flags & NEW_A)
265 			cp = print_sl_change("A+", cp);
266 		if (flags & NEW_S)
267 			cp = print_sl_change("S+", cp);
268 		break;
269 	}
270 	if (flags & NEW_I)
271 		cp = print_sl_change("I+", cp);
272 
273 	/*
274 	 * 'hlen' is the length of the uncompressed TCP/IP header (in words).
275 	 * 'cp - chdr' is the length of the compressed header.
276 	 * 'length - hlen' is the amount of data in the packet.
277 	 */
278 	hlen = ip->ip_hl;
279 	hlen += ((struct tcphdr *)&((int32_t *)ip)[hlen])->th_off;
280 	lastlen[dir][lastconn] = length - (hlen << 2);
281 	printf(" %d (%d)", lastlen[dir][lastconn], (int)(cp - chdr));
282 }
283 #else
284 #include <sys/types.h>
285 #include <sys/time.h>
286 
287 #include <pcap.h>
288 #include <stdio.h>
289 
290 #include "interface.h"
291 
292 void
293 sl_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
294 {
295 
296 	error("not configured for slip");
297 	/* NOTREACHED */
298 }
299 
300 void
301 sl_bsdos_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
302 {
303 
304 	error("not configured for slip");
305 	/* NOTREACHED */
306 }
307 #endif
308