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 1.17 2001-06-26 15:19:41 itojun Exp $";
  55 #endif
  56
  57 #include <sys/param.h>
  58 #include <sys/time.h>
  59 #include <sys/types.h>
  60 #include <ctype.h>
  61
  62 #include <netinet/in.h>
  63
  64 #include <stdio.h>
  65 #include <stdlib.h>
  66 #include <unistd.h>
  67 #include <string.h>
  68
  69 #include "interface.h"
  70 #include "addrtoname.h"
  71
  72 #define TELCMDS
  73 #define TELOPTS
  74 #include "telnet.h"
  75
  76 /* normal */
  77 static const char *cmds[] = {
  78         "IS", "SEND", "INFO",
  79 };
  80
  81 /* 37: Authentication */
  82 static const char *authcmd[] = {
  83         "IS", "SEND", "REPLY", "NAME",
  84 };
  85 static const char *authtype[] = {
  86         "NULL", "KERBEROS_V4", "KERBEROS_V5", "SPX", "MINK",
  87         "SRP", "RSA", "SSL", NULL, NULL,
  88         "LOKI", "SSA", "KEA_SJ", "KEA_SJ_INTEG", "DSS",
  89         "NTLM",
  90 };
  91
  92 /* 38: Encryption */
  93 static const char *enccmd[] = {
  94         "IS", "SUPPORT", "REPLY", "START", "END",
  95         "REQUEST-START", "REQUEST-END", "END_KEYID", "DEC_KEYID",
  96 };
  97 static const char *enctype[] = {
  98         "NULL", "DES_CFB64", "DES_OFB64", "DES3_CFB64", "DES3_OFB64",
  99         NULL, "CAST5_40_CFB64", "CAST5_40_OFB64", "CAST128_CFB64", "CAST128_OFB64",
 100 };
 101
 102 #define STR_OR_ID(x, tab) \
 103         (((x) < sizeof(tab)/sizeof(tab[0]) && tab[(x)]) ? tab[(x)] : numstr(x))
 104
 105 static char *
 106 numstr(int x)
 107 {
 108         static char buf[20];
 109
 110         snprintf(buf, sizeof(buf), "%#x", x);
 111         return buf;
 112 }
 113
 114 /* sp points to IAB byte */
 115 static int
 116 telnet_parse(const u_char *sp, u_int length, int print)
 117 {
 118         int i, c, x;
 119         const u_char *osp, *p;
 120 #define PEEK(c, sp, length) \
 121         do { \
 122                 if (length < 1) \
 123                         goto trunc; \
 124                 c = *sp; \
 125         } while (0)
 126 #define FETCH(c, sp, length) \
 127         do { \
 128                 PEEK((c), (sp), (length)); \
 129                 sp++; \
 130                 length--; \
 131         } while (0)
 132
 133         osp = sp;
 134
 135         FETCH(c, sp, length);
 136         if (c != IAC)
 137                 goto trunc;
 138         FETCH(c, sp, length);
 139         if (c == IAC) {         /* <IAC><IAC>! */
 140                 if (print)
 141                         printf("IAC IAC");
 142                 goto done;
 143         }
 144
 145         i = c - TELCMD_FIRST;
 146         if (i < 0 || i > IAC - TELCMD_FIRST)
 147                 goto trunc;
 148
 149         switch (c) {
 150         case DONT:
 151         case DO:
 152         case WONT:
 153         case WILL:
 154         case SB:
 155                 /* DONT/DO/WONT/WILL x */
 156                 FETCH(x, sp, length);
 157                 if (x >= 0 && x < NTELOPTS) {
 158                         if (print)
 159                                 (void)printf("%s %s", telcmds[i], telopts[x]);
 160                 } else {
 161                         if (print)
 162                                 (void)printf("%s %#x", telcmds[i], x);
 163                 }
 164                 if (c != SB)
 165                         break;
 166                 /* IAC SB .... IAC SE */
 167                 p = sp;
 168                 while (length > p + 1 - sp) {
 169                         if (p[0] == IAC && p[1] == SE)
 170                                 break;
 171                         p++;
 172                 }
 173                 if (*p != IAC)
 174                         goto trunc;
 175
 176                 switch (x) {
 177                 case TELOPT_AUTHENTICATION:
 178                         if (p <= sp)
 179                                 break;
 180                         FETCH(c, sp, length);
 181                         if (print)
 182                                 (void)printf(" %s", STR_OR_ID(c, authcmd));
 183                         if (p <= sp)
 184                                 break;
 185                         FETCH(c, sp, length);
 186                         if (print)
 187                                 (void)printf(" %s", STR_OR_ID(c, authtype));
 188                         break;
 189                 case TELOPT_ENCRYPT:
 190                         if (p <= sp)
 191                                 break;
 192                         FETCH(c, sp, length);
 193                         if (print)
 194                                 (void)printf(" %s", STR_OR_ID(c, enccmd));
 195                         if (p <= sp)
 196                                 break;
 197                         FETCH(c, sp, length);
 198                         if (print)
 199                                 (void)printf(" %s", STR_OR_ID(c, enctype));
 200                         break;
 201                 default:
 202                         if (p <= sp)
 203                                 break;
 204                         FETCH(c, sp, length);
 205                         if (print)
 206                                 (void)printf(" %s", STR_OR_ID(c, cmds));
 207                         break;
 208                 }
 209                 while (p > sp) {
 210                         FETCH(x, sp, length);
 211                         if (print)
 212                                 (void)printf(" %#x", x);
 213                 }
 214                 /* terminating IAC SE */
 215                 if (print)
 216                         (void)printf(" SE");
 217                 sp += 2;
 218                 length -= 2;
 219                 break;
 220         default:
 221                 if (print)
 222                         (void)printf("%s", telcmds[i]);
 223                 goto done;
 224         }
 225
 226 done:
 227         return sp - osp;
 228
 229 trunc:
 230         return -1;
 231 #undef PEEK
 232 #undef FETCH
 233 }
 234
 235 void
 236 telnet_print(const u_char *sp, u_int length)
 237 {
 238         int first = 1;
 239         const u_char *osp;
 240         int l;
 241
 242         osp = sp;
 243
 244         while (length > 0 && *sp == IAC) {
 245                 l = telnet_parse(sp, length, 0);
 246                 if (l < 0)
 247                         break;
 248
 249                 /*
 250                  * now print it
 251                  */
 252                 if (Xflag && 2 < vflag) {
 253                         if (first)
 254                                 printf("\nTelnet:");
 255                         hex_print_with_offset(sp, l, sp - osp);
 256                         if (l > 8)
 257                                 printf("\n\t\t\t\t");
 258                         else
 259                                 printf("%*s\t", (8 - l) * 3, "");
 260                 } else
 261                         printf("%s", (first) ? " [telnet " : ", ");
 262
 263                 (void)telnet_parse(sp, length, 1);
 264                 first = 0;
 265
 266                 sp += l;
 267                 length -= l;
 268         }
 269         if (!first) {
 270                 if (Xflag && 2 < vflag)
 271                         printf("\n");
 272                 else
 273                         printf("]");
 274         }
 275 }