contrib/tcpdump/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[] _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 }