1 /*
2 * Copyright (c) 1989, 1990, 1991, 1993, 1994, 1995, 1996, 1997
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 const char rcsid[] _U_ =
24 "@(#) $Header: /tcpdump/master/tcpdump/print-sl.c,v 1.65 2005/04/06 21:32:42 mcr Exp $ (LBL)";
25 #endif
26
27 #ifdef HAVE_CONFIG_H
28 #include "config.h"
29 #endif
30
31 #include <tcpdump-stdinc.h>
32
33 #include <pcap.h>
34 #include <stdio.h>
35
36 #include "interface.h"
37 #include "addrtoname.h"
38 #include "extract.h" /* must come after interface.h */
39
40 #include "ip.h"
41 #include "tcp.h"
42 #include "slip.h"
43 #include "slcompress.h"
44
45 static u_int lastlen[2][256];
46 static u_int lastconn = 255;
47
48 static void sliplink_print(const u_char *, const struct ip *, u_int);
49 static void compressed_sl_print(const u_char *, const struct ip *, u_int, int);
50
51 u_int
sl_if_print(const struct pcap_pkthdr * h,const u_char * p)52 sl_if_print(const struct pcap_pkthdr *h, const u_char *p)
53 {
54 register u_int caplen = h->caplen;
55 register u_int length = h->len;
56 register const struct ip *ip;
57
58 if (caplen < SLIP_HDRLEN) {
59 printf("[|slip]");
60 return (caplen);
61 }
62
63 length -= SLIP_HDRLEN;
64
65 ip = (struct ip *)(p + SLIP_HDRLEN);
66
67 if (eflag)
68 sliplink_print(p, ip, length);
69
70 switch (IP_V(ip)) {
71 case 4:
72 ip_print(gndo, (u_char *)ip, length);
73 break;
74 #ifdef INET6
75 case 6:
76 ip6_print((u_char *)ip, length);
77 break;
78 #endif
79 default:
80 printf ("ip v%d", IP_V(ip));
81 }
82
83 return (SLIP_HDRLEN);
84 }
85
86 u_int
sl_bsdos_if_print(const struct pcap_pkthdr * h,const u_char * p)87 sl_bsdos_if_print(const struct pcap_pkthdr *h, const u_char *p)
88 {
89 register u_int caplen = h->caplen;
90 register u_int length = h->len;
91 register const struct ip *ip;
92
93 if (caplen < SLIP_HDRLEN) {
94 printf("[|slip]");
95 return (caplen);
96 }
97
98 length -= SLIP_HDRLEN;
99
100 ip = (struct ip *)(p + SLIP_HDRLEN);
101
102 #ifdef notdef
103 if (eflag)
104 sliplink_print(p, ip, length);
105 #endif
106
107 ip_print(gndo, (u_char *)ip, length);
108
109 return (SLIP_HDRLEN);
110 }
111
112 static void
sliplink_print(register const u_char * p,register const struct ip * ip,register u_int length)113 sliplink_print(register const u_char *p, register const struct ip *ip,
114 register u_int length)
115 {
116 int dir;
117 u_int hlen;
118
119 dir = p[SLX_DIR];
120 putchar(dir == SLIPDIR_IN ? 'I' : 'O');
121 putchar(' ');
122
123 if (nflag) {
124 /* XXX just dump the header */
125 register int i;
126
127 for (i = SLX_CHDR; i < SLX_CHDR + CHDR_LEN - 1; ++i)
128 printf("%02x.", p[i]);
129 printf("%02x: ", p[SLX_CHDR + CHDR_LEN - 1]);
130 return;
131 }
132 switch (p[SLX_CHDR] & 0xf0) {
133
134 case TYPE_IP:
135 printf("ip %d: ", length + SLIP_HDRLEN);
136 break;
137
138 case TYPE_UNCOMPRESSED_TCP:
139 /*
140 * The connection id is stored in the IP protocol field.
141 * Get it from the link layer since sl_uncompress_tcp()
142 * has restored the IP header copy to IPPROTO_TCP.
143 */
144 lastconn = ((struct ip *)&p[SLX_CHDR])->ip_p;
145 hlen = IP_HL(ip);
146 hlen += TH_OFF((struct tcphdr *)&((int *)ip)[hlen]);
147 lastlen[dir][lastconn] = length - (hlen << 2);
148 printf("utcp %d: ", lastconn);
149 break;
150
151 default:
152 if (p[SLX_CHDR] & TYPE_COMPRESSED_TCP) {
153 compressed_sl_print(&p[SLX_CHDR], ip,
154 length, dir);
155 printf(": ");
156 } else
157 printf("slip-%d!: ", p[SLX_CHDR]);
158 }
159 }
160
161 static const u_char *
print_sl_change(const char * str,register const u_char * cp)162 print_sl_change(const char *str, register const u_char *cp)
163 {
164 register u_int i;
165
166 if ((i = *cp++) == 0) {
167 i = EXTRACT_16BITS(cp);
168 cp += 2;
169 }
170 printf(" %s%d", str, i);
171 return (cp);
172 }
173
174 static const u_char *
print_sl_winchange(register const u_char * cp)175 print_sl_winchange(register const u_char *cp)
176 {
177 register short i;
178
179 if ((i = *cp++) == 0) {
180 i = EXTRACT_16BITS(cp);
181 cp += 2;
182 }
183 if (i >= 0)
184 printf(" W+%d", i);
185 else
186 printf(" W%d", i);
187 return (cp);
188 }
189
190 static void
compressed_sl_print(const u_char * chdr,const struct ip * ip,u_int length,int dir)191 compressed_sl_print(const u_char *chdr, const struct ip *ip,
192 u_int length, int dir)
193 {
194 register const u_char *cp = chdr;
195 register u_int flags, hlen;
196
197 flags = *cp++;
198 if (flags & NEW_C) {
199 lastconn = *cp++;
200 printf("ctcp %d", lastconn);
201 } else
202 printf("ctcp *");
203
204 /* skip tcp checksum */
205 cp += 2;
206
207 switch (flags & SPECIALS_MASK) {
208 case SPECIAL_I:
209 printf(" *SA+%d", lastlen[dir][lastconn]);
210 break;
211
212 case SPECIAL_D:
213 printf(" *S+%d", lastlen[dir][lastconn]);
214 break;
215
216 default:
217 if (flags & NEW_U)
218 cp = print_sl_change("U=", cp);
219 if (flags & NEW_W)
220 cp = print_sl_winchange(cp);
221 if (flags & NEW_A)
222 cp = print_sl_change("A+", cp);
223 if (flags & NEW_S)
224 cp = print_sl_change("S+", cp);
225 break;
226 }
227 if (flags & NEW_I)
228 cp = print_sl_change("I+", cp);
229
230 /*
231 * 'hlen' is the length of the uncompressed TCP/IP header (in words).
232 * 'cp - chdr' is the length of the compressed header.
233 * 'length - hlen' is the amount of data in the packet.
234 */
235 hlen = IP_HL(ip);
236 hlen += TH_OFF((struct tcphdr *)&((int32_t *)ip)[hlen]);
237 lastlen[dir][lastconn] = length - (hlen << 2);
238 printf(" %d (%ld)", lastlen[dir][lastconn], (long)(cp - chdr));
239 }
240