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 #ifdef HAVE_SYS_CDEFS_H
  53 #include <sys/cdefs.h>
  54 #endif
  55 #if 0
  56 #ifndef lint
  57 __RCSID("$NetBSD: print-telnet.c,v 1.2 1999/10/11 12:40:12 sjg Exp $");
  58 #endif
  59 #endif
  60
  61 #include <sys/param.h>
  62 #include <sys/time.h>
  63 #include <sys/types.h>
  64
  65 #include <netinet/in.h>
  66 #include <netinet/in_systm.h>
  67 #include <netinet/ip.h>
  68 #include <netinet/ip_var.h>
  69 #include <netinet/tcp.h>
  70
  71 #define TELCMDS
  72 #define TELOPTS
  73 #include <arpa/telnet.h>
  74
  75 #include <stdio.h>
  76 #ifdef __STDC__
  77 #include <stdlib.h>
  78 #endif
  79 #include <unistd.h>
  80 #include <string.h>
  81
  82 #include "interface.h"
  83 #include "addrtoname.h"
  84
  85
  86 #ifndef TELCMD_FIRST
  87 # define TELCMD_FIRST SE
  88 #endif
  89
  90 void
  91 telnet_print(register const u_char *sp, u_int length)
  92 {
  93         static char tnet[128];
  94         register int i, c, x;
  95         register u_char *rcp;
  96         int off, first = 1;
  97         u_char  *osp;
  98
  99         off = 0;
 100         x = 0;
 101
 102         while (length > 0 && *sp == IAC) {
 103                 osp = (u_char *) sp;
 104                 tnet[0] = '\0';
 105
 106                 c = *sp++;
 107                 length--;
 108                 switch (*sp) {
 109                 case IAC:                       /* <IAC><IAC>! */
 110                         if (length > 1 && sp[1] == IAC) {
 111                                 (void)strcpy(tnet, "IAC IAC");
 112                         } else {
 113                                 length = 0;
 114                                 continue;
 115                         }
 116                         break;
 117                 default:
 118                         c = *sp++;
 119                         length--;
 120                         if ((i = c - TELCMD_FIRST) < 0
 121                             || i > IAC - TELCMD_FIRST) {
 122                                 (void)printf("unknown: ff%02x\n", c);
 123                                 return;
 124                         }
 125                         switch (c) {
 126                         case DONT:
 127                         case DO:
 128                         case WONT:
 129                         case WILL:
 130                         case SB:
 131                                 x = *sp++; /* option */
 132                                 length--;
 133                                 if (x >= 0 && x < NTELOPTS) {
 134                                         (void)sprintf(tnet, "%s %s",
 135                                                       telcmds[i], telopts[x]);
 136                                 } else {
 137                                         (void)sprintf(tnet, "%s %#x",
 138                                                       telcmds[i], x);
 139                                 }
 140                                 break;
 141                         default:
 142                                 (void)strcpy(tnet, telcmds[i]);
 143                         }
 144                         if (c == SB) {
 145                                 c = *sp++;
 146                                 length--;
 147                                 (void)strcat(tnet, c ? " SEND" : " IS '");
 148                                 rcp = (u_char *) sp;
 149                                 i = strlen(tnet);
 150                                 while (length > 0 && (x = *sp++) != IAC)
 151                                         --length;
 152                                 if (x == IAC) {
 153                                         if (2 < vflag
 154                                             && i + 16 + sp - rcp < sizeof(tnet)) {
 155                                                 (void)strncpy(&tnet[i], rcp, sp - rcp);
 156                                                 i += (sp - rcp) - 1;
 157                                                 tnet[i] = '\0';
 158                                         } else if (i + 8 < sizeof(tnet)) {
 159                                                 (void)strcat(&tnet[i], "...");
 160                                         }
 161                                         if (*sp++ == SE
 162                                             && i + 4 < sizeof(tnet))
 163                                                 (void)strcat(tnet, c ? " SE" : "' SE");
 164                                 } else if (i + 16 < sizeof(tnet)) {
 165                                         (void)strcat(tnet, " truncated!");
 166                                 }
 167                         }
 168                         break;
 169                 }
 170                 /*
 171                  * now print it
 172                  */
 173                 if (Xflag && 2 < vflag) {
 174                         if (first)
 175                                 printf("\nTelnet:\n");
 176                         i = sp - osp;
 177                         hex_print_with_offset(osp, i, off);
 178                         off += i;
 179                         if (i > 8)
 180                                 printf("\n\t\t\t\t%s", tnet);
 181                         else
 182                                 printf("%*s\t%s", (8 - i) * 3, "", tnet);
 183                 } else {
 184                         printf("%s%s", (first) ? " [telnet " : ", ", tnet);
 185                 }
 186                 first = 0;
 187         }
 188         if (!first) {
 189                 if (Xflag && 2 < vflag)
 190                         printf("\n");
 191                 else
 192                         printf("]");
 193         }
 194 }