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 1.18 2001-09-10 06:40:08 fenner 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 IAC 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 FETCH(c, sp, length) \
 121         do { \
 122                 if (length < 1) \
 123                         goto pktend; \
 124                 TCHECK(*sp); \
 125                 c = *sp++; \
 126                 length--; \
 127         } while (0)
 128
 129         osp = sp;
 130
 131         FETCH(c, sp, length);
 132         if (c != IAC)
 133                 goto pktend;
 134         FETCH(c, sp, length);
 135         if (c == IAC) {         /* <IAC><IAC>! */
 136                 if (print)
 137                         printf("IAC IAC");
 138                 goto done;
 139         }
 140
 141         i = c - TELCMD_FIRST;
 142         if (i < 0 || i > IAC - TELCMD_FIRST)
 143                 goto pktend;
 144
 145         switch (c) {
 146         case DONT:
 147         case DO:
 148         case WONT:
 149         case WILL:
 150         case SB:
 151                 /* DONT/DO/WONT/WILL x */
 152                 FETCH(x, sp, length);
 153                 if (x >= 0 && x < NTELOPTS) {
 154                         if (print)
 155                                 (void)printf("%s %s", telcmds[i], telopts[x]);
 156                 } else {
 157                         if (print)
 158                                 (void)printf("%s %#x", telcmds[i], x);
 159                 }
 160                 if (c != SB)
 161                         break;
 162                 /* IAC SB .... IAC SE */
 163                 p = sp;
 164                 while (length > p + 1 - sp) {
 165                         if (p[0] == IAC && p[1] == SE)
 166                                 break;
 167                         p++;
 168                 }
 169                 if (*p != IAC)
 170                         goto pktend;
 171
 172                 switch (x) {
 173                 case TELOPT_AUTHENTICATION:
 174                         if (p <= sp)
 175                                 break;
 176                         FETCH(c, sp, length);
 177                         if (print)
 178                                 (void)printf(" %s", STR_OR_ID(c, authcmd));
 179                         if (p <= sp)
 180                                 break;
 181                         FETCH(c, sp, length);
 182                         if (print)
 183                                 (void)printf(" %s", STR_OR_ID(c, authtype));
 184                         break;
 185                 case TELOPT_ENCRYPT:
 186                         if (p <= sp)
 187                                 break;
 188                         FETCH(c, sp, length);
 189                         if (print)
 190                                 (void)printf(" %s", STR_OR_ID(c, enccmd));
 191                         if (p <= sp)
 192                                 break;
 193                         FETCH(c, sp, length);
 194                         if (print)
 195                                 (void)printf(" %s", STR_OR_ID(c, enctype));
 196                         break;
 197                 default:
 198                         if (p <= sp)
 199                                 break;
 200                         FETCH(c, sp, length);
 201                         if (print)
 202                                 (void)printf(" %s", STR_OR_ID(c, cmds));
 203                         break;
 204                 }
 205                 while (p > sp) {
 206                         FETCH(x, sp, length);
 207                         if (print)
 208                                 (void)printf(" %#x", x);
 209                 }
 210                 /* terminating IAC SE */
 211                 if (print)
 212                         (void)printf(" SE");
 213                 sp += 2;
 214                 length -= 2;
 215                 break;
 216         default:
 217                 if (print)
 218                         (void)printf("%s", telcmds[i]);
 219                 goto done;
 220         }
 221
 222 done:
 223         return sp - osp;
 224
 225 trunc:
 226         (void)printf("[|telnet]");
 227 pktend:
 228         return -1;
 229 #undef FETCH
 230 }
 231
 232 void
 233 telnet_print(const u_char *sp, u_int length)
 234 {
 235         int first = 1;
 236         const u_char *osp;
 237         int l;
 238
 239         osp = sp;
 240
 241         while (length > 0 && *sp == IAC) {
 242                 l = telnet_parse(sp, length, 0);
 243                 if (l < 0)
 244                         break;
 245
 246                 /*
 247                  * now print it
 248                  */
 249                 if (Xflag && 2 < vflag) {
 250                         if (first)
 251                                 printf("\nTelnet:");
 252                         hex_print_with_offset(sp, l, sp - osp);
 253                         if (l > 8)
 254                                 printf("\n\t\t\t\t");
 255                         else
 256                                 printf("%*s\t", (8 - l) * 3, "");
 257                 } else
 258                         printf("%s", (first) ? " [telnet " : ", ");
 259
 260                 (void)telnet_parse(sp, length, 1);
 261                 first = 0;
 262
 263                 sp += l;
 264                 length -= l;
 265         }
 266         if (!first) {
 267                 if (Xflag && 2 < vflag)
 268                         printf("\n");
 269                 else
 270                         printf("]");
 271         }
 272 }