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
