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 1.16 2001-06-26 03:01:10 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 #define TELCMDS
  65 #define TELOPTS
  66 #include <arpa/telnet.h>
  67
  68 #include <stdio.h>
  69 #include <stdlib.h>
  70 #include <unistd.h>
  71 #include <string.h>
  72
  73 #include "interface.h"
  74 #include "addrtoname.h"
  75
  76 #ifndef TELCMD_FIRST
  77 # define TELCMD_FIRST SE
  78 #endif
  79
  80 /* normal */
  81 static const char *cmds[] = {
  82         "IS", "SEND", "INFO",
  83 };
  84
  85 /* 37: Authentication */
  86 static const char *authcmd[] = {
  87         "IS", "SEND", "REPLY", "NAME",
  88 };
  89 static const char *authtype[] = {
  90         "NULL", "KERBEROS_V4", "KERBEROS_V5", "SPX", "MINK",
  91         "SRP", "RSA", "SSL", NULL, NULL,
  92         "LOKI", "SSA", "KEA_SJ", "KEA_SJ_INTEG", "DSS",
  93         "NTLM",
  94 };
  95
  96 /* 38: Encryption */
  97 static const char *enccmd[] = {
  98         "IS", "SUPPORT", "REPLY", "START", "END",
  99         "REQUEST-START", "REQUEST-END", "END_KEYID", "DEC_KEYID",
 100 };
 101 static const char *enctype[] = {
 102         "NULL", "DES_CFB64", "DES_OFB64", "DES3_CFB64", "DES3_OFB64",
 103         NULL, "CAST5_40_CFB64", "CAST5_40_OFB64", "CAST128_CFB64", "CAST128_OFB64",
 104 };
 105
 106 #define STR_OR_ID(x, tab) \
 107         (((x) < sizeof(tab)/sizeof(tab[0]) && tab[(x)]) ? tab[(x)] : numstr(x))
 108
 109 static char *
 110 numstr(int x)
 111 {
 112         static char buf[20];
 113
 114         snprintf(buf, sizeof(buf), "%#x", x);
 115         return buf;
 116 }
 117
 118 /* sp points to IAB byte */
 119 static int
 120 telnet_parse(const u_char *sp, u_int length, int print)
 121 {
 122         int i, c, x;
 123         const u_char *osp, *p;
 124 #define PEEK(c, sp, length) \
 125         do { \
 126                 if (length < 1) \
 127                         goto trunc; \
 128                 c = *sp; \
 129         } while (0)
 130 #define FETCH(c, sp, length) \
 131         do { \
 132                 PEEK((c), (sp), (length)); \
 133                 sp++; \
 134                 length--; \
 135         } while (0)
 136
 137         osp = sp;
 138
 139         FETCH(c, sp, length);
 140         if (c != IAC)
 141                 goto trunc;
 142         FETCH(c, sp, length);
 143         if (c == IAC) {         /* <IAC><IAC>! */
 144                 if (print)
 145                         printf("IAC IAC");
 146                 goto done;
 147         }
 148
 149         i = c - TELCMD_FIRST;
 150         if (i < 0 || i > IAC - TELCMD_FIRST)
 151                 goto trunc;
 152
 153         switch (c) {
 154         case DONT:
 155         case DO:
 156         case WONT:
 157         case WILL:
 158         case SB:
 159                 /* DONT/DO/WONT/WILL x */
 160                 FETCH(x, sp, length);
 161                 if (x >= 0 && x < NTELOPTS) {
 162                         if (print)
 163                                 (void)printf("%s %s", telcmds[i], telopts[x]);
 164                 } else {
 165                         if (print)
 166                                 (void)printf("%s %#x", telcmds[i], x);
 167                 }
 168                 if (c != SB)
 169                         break;
 170                 /* IAC SB .... IAC SE */
 171                 p = sp;
 172                 while (length > p + 1 - sp) {
 173                         if (p[0] == IAC && p[1] == SE)
 174                                 break;
 175                         p++;
 176                 }
 177                 if (*p != IAC)
 178                         goto trunc;
 179
 180                 switch (x) {
 181                 case TELOPT_AUTHENTICATION:
 182                         if (p <= sp)
 183                                 break;
 184                         FETCH(c, sp, length);
 185                         if (print)
 186                                 (void)printf(" %s", STR_OR_ID(c, authcmd));
 187                         if (p <= sp)
 188                                 break;
 189                         FETCH(c, sp, length);
 190                         if (print)
 191                                 (void)printf(" %s", STR_OR_ID(c, authtype));
 192                         break;
 193                 case TELOPT_ENCRYPT:
 194                         if (p <= sp)
 195                                 break;
 196                         FETCH(c, sp, length);
 197                         if (print)
 198                                 (void)printf(" %s", STR_OR_ID(c, enccmd));
 199                         if (p <= sp)
 200                                 break;
 201                         FETCH(c, sp, length);
 202                         if (print)
 203                                 (void)printf(" %s", STR_OR_ID(c, enctype));
 204                         break;
 205                 default:
 206                         if (p <= sp)
 207                                 break;
 208                         FETCH(c, sp, length);
 209                         if (print)
 210                                 (void)printf(" %s", STR_OR_ID(c, cmds));
 211                         break;
 212                 }
 213                 while (p > sp) {
 214                         FETCH(x, sp, length);
 215                         if (print)
 216                                 (void)printf(" %#x", x);
 217                 }
 218                 /* terminating IAC SE */
 219                 if (print)
 220                         (void)printf(" SE");
 221                 sp += 2;
 222                 length -= 2;
 223                 break;
 224         default:
 225                 if (print)
 226                         (void)printf("%s", telcmds[i]);
 227                 goto done;
 228         }
 229
 230 done:
 231         return sp - osp;
 232
 233 trunc:
 234         return -1;
 235 #undef PEEK
 236 #undef FETCH
 237 }
 238
 239 void
 240 telnet_print(const u_char *sp, u_int length)
 241 {
 242         int first = 1;
 243         const u_char *osp;
 244         int l;
 245
 246         osp = sp;
 247
 248         while (length > 0 && *sp == IAC) {
 249                 l = telnet_parse(sp, length, 0);
 250                 if (l < 0)
 251                         break;
 252
 253                 /*
 254                  * now print it
 255                  */
 256                 if (Xflag && 2 < vflag) {
 257                         if (first)
 258                                 printf("\nTelnet:");
 259                         hex_print_with_offset(sp, l, sp - osp);
 260                         if (l > 8)
 261                                 printf("\n\t\t\t\t");
 262                         else
 263                                 printf("%*s\t", (8 - l) * 3, "");
 264                 } else
 265                         printf("%s", (first) ? " [telnet " : ", ");
 266
 267                 (void)telnet_parse(sp, length, 1);
 268                 first = 0;
 269
 270                 sp += l;
 271                 length -= l;
 272         }
 273         if (!first) {
 274                 if (Xflag && 2 < vflag)
 275                         printf("\n");
 276                 else
 277                         printf("]");
 278         }
 279 }