xref: /freebsd/contrib/tcpdump/print-sl.c (revision 8e537d168674d6b65869f73c20813001af875738)
1 /*
2  * Copyright (c) 1989, 1990, 1991, 1993, 1994, 1995, 1996
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that: (1) source code distributions
7  * retain the above copyright notice and this paragraph in its entirety, (2)
8  * distributions including binary code include the above copyright notice and
9  * this paragraph in its entirety in the documentation or other materials
10  * provided with the distribution, and (3) all advertising materials mentioning
11  * features or use of this software display the following acknowledgement:
12  * ``This product includes software developed by the University of California,
13  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
14  * the University nor the names of its contributors may be used to endorse
15  * or promote products derived from this software without specific prior
16  * written permission.
17  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
18  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
19  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
20  */
21 
22 #ifndef lint
23 static  char rcsid[] =
24 	"@(#)$Header: print-sl.c,v 1.38 96/07/15 18:23:25 leres Exp $ (LBL)";
25 #endif
26 
27 #ifdef HAVE_NET_SLIP_H
28 #include <sys/param.h>
29 #include <sys/time.h>
30 #include <sys/timeb.h>
31 #include <sys/file.h>
32 #include <sys/ioctl.h>
33 #include <sys/mbuf.h>
34 #include <sys/socket.h>
35 
36 #if __STDC__
37 struct rtentry;
38 #endif
39 #include <net/if.h>
40 
41 #include <netinet/in.h>
42 #include <netinet/in_systm.h>
43 #include <netinet/ip.h>
44 #include <netinet/if_ether.h>
45 #include <netinet/ip_var.h>
46 #include <netinet/udp.h>
47 #include <netinet/udp_var.h>
48 #include <netinet/tcp.h>
49 #include <netinet/tcpip.h>
50 
51 #include <net/slcompress.h>
52 #include <net/slip.h>
53 
54 #include <ctype.h>
55 #include <netdb.h>
56 #include <pcap.h>
57 #include <signal.h>
58 #include <stdio.h>
59 
60 #include "interface.h"
61 #include "addrtoname.h"
62 #include "extract.h"			/* must come after interface.h */
63 
64 static u_int lastlen[2][256];
65 static u_int lastconn = 255;
66 
67 static void sliplink_print(const u_char *, const struct ip *, u_int);
68 static void compressed_sl_print(const u_char *, const struct ip *, u_int, int);
69 
70 /* XXX BSD/OS 2.1 compatibility */
71 #if !defined(SLIP_HDRLEN) && defined(SLC_BPFHDR)
72 #define SLIP_HDRLEN SLC_BPFHDR
73 #define SLX_DIR 0
74 #define SLX_CHDR (SLC_BPFHDRLEN - 1)
75 #define CHDR_LEN (SLC_BPFHDR - SLC_BPFHDRLEN)
76 #endif
77 
78 void
79 sl_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
80 {
81 	register u_int caplen = h->caplen;
82 	register u_int length = h->len;
83 	register const struct ip *ip;
84 
85 	ts_print(&h->ts);
86 
87 	if (caplen < SLIP_HDRLEN) {
88 		printf("[|slip]");
89 		goto out;
90 	}
91 	/*
92 	 * Some printers want to get back at the link level addresses,
93 	 * and/or check that they're not walking off the end of the packet.
94 	 * Rather than pass them all the way down, we set these globals.
95 	 */
96 	packetp = p;
97 	snapend = p + caplen;
98 
99 	length -= SLIP_HDRLEN;
100 
101 	ip = (struct ip *)(p + SLIP_HDRLEN);
102 
103 	if (eflag)
104 		sliplink_print(p, ip, length);
105 
106 	ip_print((u_char *)ip, length);
107 
108 	if (xflag)
109 		default_print((u_char *)ip, caplen - SLIP_HDRLEN);
110  out:
111 	putchar('\n');
112 }
113 
114 static void
115 sliplink_print(register const u_char *p, register const struct ip *ip,
116 	       register u_int length)
117 {
118 	int dir;
119 	u_int hlen;
120 
121 	dir = p[SLX_DIR];
122 	putchar(dir == SLIPDIR_IN ? 'I' : 'O');
123 	putchar(' ');
124 
125 	if (nflag) {
126 		/* XXX just dump the header */
127 		register int i;
128 
129 		for (i = SLX_CHDR; i < SLX_CHDR + CHDR_LEN - 1; ++i)
130 			printf("%02x.", p[i]);
131 		printf("%02x: ", p[SLX_CHDR + CHDR_LEN - 1]);
132 		return;
133 	}
134 	switch (p[SLX_CHDR] & 0xf0) {
135 
136 	case TYPE_IP:
137 		printf("ip %d: ", length + SLIP_HDRLEN);
138 		break;
139 
140 	case TYPE_UNCOMPRESSED_TCP:
141 		/*
142 		 * The connection id is stored in the IP protcol field.
143 		 * Get it from the link layer since sl_uncompress_tcp()
144 		 * has restored the IP header copy to IPPROTO_TCP.
145 		 */
146 		lastconn = ((struct ip *)&p[SLX_CHDR])->ip_p;
147 		hlen = ip->ip_hl;
148 		hlen += ((struct tcphdr *)&((int *)ip)[hlen])->th_off;
149 		lastlen[dir][lastconn] = length - (hlen << 2);
150 		printf("utcp %d: ", lastconn);
151 		break;
152 
153 	default:
154 		if (p[SLX_CHDR] & TYPE_COMPRESSED_TCP) {
155 			compressed_sl_print(&p[SLX_CHDR], ip,
156 			    length, dir);
157 			printf(": ");
158 		} else
159 			printf("slip-%d!: ", p[SLX_CHDR]);
160 	}
161 }
162 
163 static const u_char *
164 print_sl_change(const char *str, register const u_char *cp)
165 {
166 	register u_int i;
167 
168 	if ((i = *cp++) == 0) {
169 		i = EXTRACT_16BITS(cp);
170 		cp += 2;
171 	}
172 	printf(" %s%d", str, i);
173 	return (cp);
174 }
175 
176 static const u_char *
177 print_sl_winchange(register const u_char *cp)
178 {
179 	register short i;
180 
181 	if ((i = *cp++) == 0) {
182 		i = EXTRACT_16BITS(cp);
183 		cp += 2;
184 	}
185 	if (i >= 0)
186 		printf(" W+%d", i);
187 	else
188 		printf(" W%d", i);
189 	return (cp);
190 }
191 
192 static void
193 compressed_sl_print(const u_char *chdr, const struct ip *ip,
194 		    u_int length, int dir)
195 {
196 	register const u_char *cp = chdr;
197 	register u_int flags, hlen;
198 
199 	flags = *cp++;
200 	if (flags & NEW_C) {
201 		lastconn = *cp++;
202 		printf("ctcp %d", lastconn);
203 	} else
204 		printf("ctcp *");
205 
206 	/* skip tcp checksum */
207 	cp += 2;
208 
209 	switch (flags & SPECIALS_MASK) {
210 	case SPECIAL_I:
211 		printf(" *SA+%d", lastlen[dir][lastconn]);
212 		break;
213 
214 	case SPECIAL_D:
215 		printf(" *S+%d", lastlen[dir][lastconn]);
216 		break;
217 
218 	default:
219 		if (flags & NEW_U)
220 			cp = print_sl_change("U=", cp);
221 		if (flags & NEW_W)
222 			cp = print_sl_winchange(cp);
223 		if (flags & NEW_A)
224 			cp = print_sl_change("A+", cp);
225 		if (flags & NEW_S)
226 			cp = print_sl_change("S+", cp);
227 		break;
228 	}
229 	if (flags & NEW_I)
230 		cp = print_sl_change("I+", cp);
231 
232 	/*
233 	 * 'hlen' is the length of the uncompressed TCP/IP header (in words).
234 	 * 'cp - chdr' is the length of the compressed header.
235 	 * 'length - hlen' is the amount of data in the packet.
236 	 */
237 	hlen = ip->ip_hl;
238 	hlen += ((struct tcphdr *)&((int32_t *)ip)[hlen])->th_off;
239 	lastlen[dir][lastconn] = length - (hlen << 2);
240 	printf(" %d (%d)", lastlen[dir][lastconn], cp - chdr);
241 }
242 #else
243 #include <sys/types.h>
244 #include <sys/time.h>
245 
246 #include <stdio.h>
247 
248 #include "interface.h"
249 void
250 sl_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
251 {
252 
253 	error("not configured for slip");
254 	/* NOTREACHED */
255 }
256 #endif
257