The Tcpdump Group git mirrors - tcpdump/blob - print-telnet.c

   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[] =
  54      "@(#) $Header: /tcpdump/master/tcpdump/print-telnet.c,v 1.20 2002-08-01 08:53:32 risso 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, c, x;
 113         const u_char *osp, *p;
 114 #define FETCH(c, sp, length) \
 115         do { \
 116                 if (length < 1) \
 117                         goto pktend; \
 118                 TCHECK(*sp); \
 119                 c = *sp++; \
 120                 length--; \
 121         } while (0)
 122
 123         osp = sp;
 124
 125         FETCH(c, sp, length);
 126         if (c != IAC)
 127                 goto pktend;
 128         FETCH(c, sp, length);
 129         if (c == IAC) {         /* <IAC><IAC>! */
 130                 if (print)
 131                         printf("IAC IAC");
 132                 goto done;
 133         }
 134
 135         i = c - TELCMD_FIRST;
 136         if (i < 0 || i > IAC - TELCMD_FIRST)
 137                 goto pktend;
 138
 139         switch (c) {
 140         case DONT:
 141         case DO:
 142         case WONT:
 143         case WILL:
 144         case SB:
 145                 /* DONT/DO/WONT/WILL x */
 146                 FETCH(x, sp, length);
 147                 if (x >= 0 && x < NTELOPTS) {
 148                         if (print)
 149                                 (void)printf("%s %s", telcmds[i], telopts[x]);
 150                 } else {
 151                         if (print)
 152                                 (void)printf("%s %#x", telcmds[i], x);
 153                 }
 154                 if (c != SB)
 155                         break;
 156                 /* IAC SB .... IAC SE */
 157                 p = sp;
 158                 while (length > p + 1 - sp) {
 159                         if (p[0] == IAC && p[1] == SE)
 160                                 break;
 161                         p++;
 162                 }
 163                 if (*p != IAC)
 164                         goto pktend;
 165
 166                 switch (x) {
 167                 case TELOPT_AUTHENTICATION:
 168                         if (p <= sp)
 169                                 break;
 170                         FETCH(c, sp, length);
 171                         if (print)
 172                                 (void)printf(" %s", STR_OR_ID(c, authcmd));
 173                         if (p <= sp)
 174                                 break;
 175                         FETCH(c, sp, length);
 176                         if (print)
 177                                 (void)printf(" %s", STR_OR_ID(c, authtype));
 178                         break;
 179                 case TELOPT_ENCRYPT:
 180                         if (p <= sp)
 181                                 break;
 182                         FETCH(c, sp, length);
 183                         if (print)
 184                                 (void)printf(" %s", STR_OR_ID(c, enccmd));
 185                         if (p <= sp)
 186                                 break;
 187                         FETCH(c, sp, length);
 188                         if (print)
 189                                 (void)printf(" %s", STR_OR_ID(c, enctype));
 190                         break;
 191                 default:
 192                         if (p <= sp)
 193                                 break;
 194                         FETCH(c, sp, length);
 195                         if (print)
 196                                 (void)printf(" %s", STR_OR_ID(c, cmds));
 197                         break;
 198                 }
 199                 while (p > sp) {
 200                         FETCH(x, sp, length);
 201                         if (print)
 202                                 (void)printf(" %#x", x);
 203                 }
 204                 /* terminating IAC SE */
 205                 if (print)
 206                         (void)printf(" SE");
 207                 sp += 2;
 208                 length -= 2;
 209                 break;
 210         default:
 211                 if (print)
 212                         (void)printf("%s", telcmds[i]);
 213                 goto done;
 214         }
 215
 216 done:
 217         return sp - osp;
 218
 219 trunc:
 220         (void)printf("[|telnet]");
 221 pktend:
 222         return -1;
 223 #undef FETCH
 224 }
 225
 226 void
 227 telnet_print(const u_char *sp, u_int length)
 228 {
 229         int first = 1;
 230         const u_char *osp;
 231         int l;
 232
 233         osp = sp;
 234
 235         while (length > 0 && *sp == IAC) {
 236                 l = telnet_parse(sp, length, 0);
 237                 if (l < 0)
 238                         break;
 239
 240                 /*
 241                  * now print it
 242                  */
 243                 if (Xflag && 2 < vflag) {
 244                         if (first)
 245                                 printf("\nTelnet:");
 246                         hex_print_with_offset(sp, l, sp - osp);
 247                         if (l > 8)
 248                                 printf("\n\t\t\t\t");
 249                         else
 250                                 printf("%*s\t", (8 - l) * 3, "");
 251                 } else
 252                         printf("%s", (first) ? " [telnet " : ", ");
 253
 254                 (void)telnet_parse(sp, length, 1);
 255                 first = 0;
 256
 257                 sp += l;
 258                 length -= l;
 259         }
 260         if (!first) {
 261                 if (Xflag && 2 < vflag)
 262                         printf("\n");
 263                 else
 264                         printf("]");
 265         }
 266 }