1 /* $NetBSD: print-telnet.c,v 1.2 1999/10/11 12:40:12 sjg Exp $ */
2
3 /*-
4 * Copyright (c) 1997, 1998 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Simon J. Gerraty.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by the NetBSD
21 * Foundation, Inc. and its contributors.
22 * 4. Neither the name of The NetBSD Foundation nor the names of its
23 * contributors may be used to endorse or promote products derived
24 * from this software without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36 * POSSIBILITY OF SUCH DAMAGE.
37 */
38 /*
39 * @(#)Copyright (c) 1994, Simon J. Gerraty.
40 *
41 * This is free software. It comes with NO WARRANTY.
42 * Permission to use, modify and distribute this source code
43 * is granted subject to the following conditions.
44 * 1/ that the above copyright notice and this notice
45 * are preserved in all copies.
46 */
47
48 #ifdef HAVE_CONFIG_H
49 #include "config.h"
50 #endif
51
52 #ifndef lint
53 static const char rcsid[] _U_ =
54 "@(#) $Header: /tcpdump/master/tcpdump/print-telnet.c,v 1.24 2003-12-29 11:05:10 hannes Exp $";
55 #endif
56
57 #include <tcpdump-stdinc.h>
58
59 #include <stdio.h>
60 #include <stdlib.h>
61 #include <string.h>
62
63 #include "interface.h"
64 #include "addrtoname.h"
65
66 #define TELCMDS
67 #define TELOPTS
68 #include "telnet.h"
69
70 /* normal */
71 static const char *cmds[] = {
72 "IS", "SEND", "INFO",
73 };
74
75 /* 37: Authentication */
76 static const char *authcmd[] = {
77 "IS", "SEND", "REPLY", "NAME",
78 };
79 static const char *authtype[] = {
80 "NULL", "KERBEROS_V4", "KERBEROS_V5", "SPX", "MINK",
81 "SRP", "RSA", "SSL", NULL, NULL,
82 "LOKI", "SSA", "KEA_SJ", "KEA_SJ_INTEG", "DSS",
83 "NTLM",
84 };
85
86 /* 38: Encryption */
87 static const char *enccmd[] = {
88 "IS", "SUPPORT", "REPLY", "START", "END",
89 "REQUEST-START", "REQUEST-END", "END_KEYID", "DEC_KEYID",
90 };
91 static const char *enctype[] = {
92 "NULL", "DES_CFB64", "DES_OFB64", "DES3_CFB64", "DES3_OFB64",
93 NULL, "CAST5_40_CFB64", "CAST5_40_OFB64", "CAST128_CFB64", "CAST128_OFB64",
94 };
95
96 #define STR_OR_ID(x, tab) \
97 (((x) < sizeof(tab)/sizeof(tab[0]) && tab[(x)]) ? tab[(x)] : numstr(x))
98
99 static char *
numstr(int x)100 numstr(int x)
101 {
102 static char buf[20];
103
104 snprintf(buf, sizeof(buf), "%#x", x);
105 return buf;
106 }
107
108 /* sp points to IAC byte */
109 static int
telnet_parse(const u_char * sp,u_int length,int print)110 telnet_parse(const u_char *sp, u_int length, int print)
111 {
112 int i, x;
113 u_int c;
114 const u_char *osp, *p;
115 #define FETCH(c, sp, length) \
116 do { \
117 if (length < 1) \
118 goto pktend; \
119 TCHECK(*sp); \
120 c = *sp++; \
121 length--; \
122 } while (0)
123
124 osp = sp;
125
126 FETCH(c, sp, length);
127 if (c != IAC)
128 goto pktend;
129 FETCH(c, sp, length);
130 if (c == IAC) { /* <IAC><IAC>! */
131 if (print)
132 printf("IAC IAC");
133 goto done;
134 }
135
136 i = c - TELCMD_FIRST;
137 if (i < 0 || i > IAC - TELCMD_FIRST)
138 goto pktend;
139
140 switch (c) {
141 case DONT:
142 case DO:
143 case WONT:
144 case WILL:
145 case SB:
146 /* DONT/DO/WONT/WILL x */
147 FETCH(x, sp, length);
148 if (x >= 0 && x < NTELOPTS) {
149 if (print)
150 (void)printf("%s %s", telcmds[i], telopts[x]);
151 } else {
152 if (print)
153 (void)printf("%s %#x", telcmds[i], x);
154 }
155 if (c != SB)
156 break;
157 /* IAC SB .... IAC SE */
158 p = sp;
159 while (length > (u_int)(p + 1 - sp)) {
160 if (p[0] == IAC && p[1] == SE)
161 break;
162 p++;
163 }
164 if (*p != IAC)
165 goto pktend;
166
167 switch (x) {
168 case TELOPT_AUTHENTICATION:
169 if (p <= sp)
170 break;
171 FETCH(c, sp, length);
172 if (print)
173 (void)printf(" %s", STR_OR_ID(c, authcmd));
174 if (p <= sp)
175 break;
176 FETCH(c, sp, length);
177 if (print)
178 (void)printf(" %s", STR_OR_ID(c, authtype));
179 break;
180 case TELOPT_ENCRYPT:
181 if (p <= sp)
182 break;
183 FETCH(c, sp, length);
184 if (print)
185 (void)printf(" %s", STR_OR_ID(c, enccmd));
186 if (p <= sp)
187 break;
188 FETCH(c, sp, length);
189 if (print)
190 (void)printf(" %s", STR_OR_ID(c, enctype));
191 break;
192 default:
193 if (p <= sp)
194 break;
195 FETCH(c, sp, length);
196 if (print)
197 (void)printf(" %s", STR_OR_ID(c, cmds));
198 break;
199 }
200 while (p > sp) {
201 FETCH(x, sp, length);
202 if (print)
203 (void)printf(" %#x", x);
204 }
205 /* terminating IAC SE */
206 if (print)
207 (void)printf(" SE");
208 sp += 2;
209 length -= 2;
210 break;
211 default:
212 if (print)
213 (void)printf("%s", telcmds[i]);
214 goto done;
215 }
216
217 done:
218 return sp - osp;
219
220 trunc:
221 (void)printf("[|telnet]");
222 pktend:
223 return -1;
224 #undef FETCH
225 }
226
227 void
telnet_print(const u_char * sp,u_int length)228 telnet_print(const u_char *sp, u_int length)
229 {
230 int first = 1;
231 const u_char *osp;
232 int l;
233
234 osp = sp;
235
236 while (length > 0 && *sp == IAC) {
237 l = telnet_parse(sp, length, 0);
238 if (l < 0)
239 break;
240
241 /*
242 * now print it
243 */
244 if (Xflag && 2 < vflag) {
245 if (first)
246 printf("\nTelnet:");
247 hex_print_with_offset("\n", sp, l, sp - osp);
248 if (l > 8)
249 printf("\n\t\t\t\t");
250 else
251 printf("%*s\t", (8 - l) * 3, "");
252 } else
253 printf("%s", (first) ? " [telnet " : ", ");
254
255 (void)telnet_parse(sp, length, 1);
256 first = 0;
257
258 sp += l;
259 length -= l;
260 }
261 if (!first) {
262 if (Xflag && 2 < vflag)
263 printf("\n");
264 else
265 printf("]");
266 }
267 }
268