Home | History | Annotate | Download | only in tcpdump
      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 *
    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
    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
    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