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 1.6 2000-01-17 06:24:26 itojun Exp $";
  55 #endif
  56
  57 #include <sys/param.h>
  58 #include <sys/time.h>
  59 #include <sys/types.h>
  60
  61 #include <netinet/in.h>
  62 #include <netinet/in_systm.h>
  63 #include <netinet/ip.h>
  64 #include <netinet/ip_var.h>
  65 #include <netinet/tcp.h>
  66
  67 #define TELCMDS
  68 #define TELOPTS
  69 #include <arpa/telnet.h>
  70
  71 #include <stdio.h>
  72 #ifdef __STDC__
  73 #include <stdlib.h>
  74 #endif
  75 #include <unistd.h>
  76 #include <string.h>
  77
  78 #include "interface.h"
  79 #include "addrtoname.h"
  80
  81
  82 #ifndef TELCMD_FIRST
  83 # define TELCMD_FIRST SE
  84 #endif
  85
  86 void
  87 telnet_print(register const u_char *sp, u_int length)
  88 {
  89         static char tnet[128];
  90         register int i, c, x;
  91         register u_char *rcp;
  92         int off, first = 1;
  93         u_char  *osp;
  94
  95         off = 0;
  96         x = 0;
  97
  98         while (length > 0 && *sp == IAC) {
  99                 osp = (u_char *) sp;
 100                 tnet[0] = '\0';
 101
 102                 c = *sp++;
 103                 length--;
 104                 switch (*sp) {
 105                 case IAC:                       /* <IAC><IAC>! */
 106                         if (length > 1 && sp[1] == IAC) {
 107                                 (void)strcpy(tnet, "IAC IAC");
 108                         } else {
 109                                 length = 0;
 110                                 continue;
 111                         }
 112                         break;
 113                 default:
 114                         c = *sp++;
 115                         length--;
 116                         if ((i = c - TELCMD_FIRST) < 0
 117                             || i > IAC - TELCMD_FIRST) {
 118                                 (void)printf("unknown: ff%02x\n", c);
 119                                 return;
 120                         }
 121                         switch (c) {
 122                         case DONT:
 123                         case DO:
 124                         case WONT:
 125                         case WILL:
 126                         case SB:
 127                                 x = *sp++; /* option */
 128                                 length--;
 129                                 if (x >= 0 && x < NTELOPTS) {
 130                                         (void)snprintf(tnet, sizeof(tnet),
 131                                             "%s %s", telcmds[i], telopts[x]);
 132                                 } else {
 133                                         (void)snprintf(tnet, sizeof(tnet),
 134                                             "%s %#x", telcmds[i], x);
 135                                 }
 136                                 break;
 137                         default:
 138                                 (void)snprintf(tnet, sizeof(tnet), "%s",
 139                                     telcmds[i]);
 140                         }
 141                         if (c == SB) {
 142                                 c = *sp++;
 143                                 length--;
 144                                 (void)strcat(tnet, c ? " SEND" : " IS '");
 145                                 rcp = (u_char *) sp;
 146                                 i = strlen(tnet);
 147                                 while (length > 0 && (x = *sp++) != IAC)
 148                                         --length;
 149                                 if (x == IAC) {
 150                                         if (2 < vflag
 151                                             && i + 16 + sp - rcp < sizeof(tnet)) {
 152                                                 (void)strncpy(&tnet[i], rcp, sp - rcp);
 153                                                 i += (sp - rcp) - 1;
 154                                                 tnet[i] = '\0';
 155                                         } else if (i + 8 < sizeof(tnet)) {
 156                                                 (void)strcat(&tnet[i], "...");
 157                                         }
 158                                         if (*sp++ == SE
 159                                             && i + 4 < sizeof(tnet))
 160                                                 (void)strcat(tnet, c ? " SE" : "' SE");
 161                                 } else if (i + 16 < sizeof(tnet)) {
 162                                         (void)strcat(tnet, " truncated!");
 163                                 }
 164                         }
 165                         break;
 166                 }
 167                 /*
 168                  * now print it
 169                  */
 170                 if (Xflag && 2 < vflag) {
 171                         if (first)
 172                                 printf("\nTelnet:\n");
 173                         i = sp - osp;
 174                         hex_print_with_offset(osp, i, off);
 175                         off += i;
 176                         if (i > 8)
 177                                 printf("\n\t\t\t\t%s", tnet);
 178                         else
 179                                 printf("%*s\t%s", (8 - i) * 3, "", tnet);
 180                 } else {
 181                         printf("%s%s", (first) ? " [telnet " : ", ", tnet);
 182                 }
 183                 first = 0;
 184         }
 185         if (!first) {
 186                 if (Xflag && 2 < vflag)
 187                         printf("\n");
 188                 else
 189                         printf("]");
 190         }
 191 }