telnet.c

/***************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) 1998 - 2007, Daniel Stenberg, <daniel@haxx.se>, et al.
 *
 * This software is licensed as described in the file COPYING, which
 * you should have received as part of this distribution. The terms
 * are also available at http://curl.haxx.se/docs/copyright.html.
 *
 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
 * copies of the Software, and permit persons to whom the Software is
 * furnished to do so, under the terms of the COPYING file.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 * $Id$
 ***************************************************************************/

#include "setup.h"

#ifndef CURL_DISABLE_TELNET
/* -- WIN32 approved -- */
#include <stdio.h>
#include <string.h>
#include <stdarg.h>
#include <stdlib.h>
#include <ctype.h>

#if defined(WIN32)
#include <time.h>
#include <io.h>
#else
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#include <netinet/in.h>
#ifdef HAVE_SYS_TIME_H
#include <sys/time.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <netdb.h>
#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif
#ifdef HAVE_NET_IF_H
#include <net/if.h>
#endif
#include <sys/ioctl.h>
#include <signal.h>

#ifdef HAVE_SYS_PARAM_H
#include <sys/param.h>
#endif

#endif  /* WIN32 */

#include "urldata.h"
#include <curl/curl.h>
#include "transfer.h"
#include "sendf.h"
#include "telnet.h"
#include "connect.h"

#define _MPRINTF_REPLACE /* use our functions only */
#include <curl/mprintf.h>

#define  TELOPTS
#define  TELCMDS

#include "arpa_telnet.h"
#include "memory.h"
#include "select.h"

/* The last #include file should be: */
#include "memdebug.h"

#define SUBBUFSIZE 512

#define CURL_SB_CLEAR(x)  x->subpointer = x->subbuffer;
#define CURL_SB_TERM(x)   { x->subend = x->subpointer; CURL_SB_CLEAR(x); }
#define CURL_SB_ACCUM(x,c) \
  if(x->subpointer < (x->subbuffer+sizeof x->subbuffer)) { \
    *x->subpointer++ = (c); \
  }

#define  CURL_SB_GET(x) ((*x->subpointer++)&0xff)
#define  CURL_SB_PEEK(x)   ((*x->subpointer)&0xff)
#define  CURL_SB_EOF(x) (x->subpointer >= x->subend)
#define  CURL_SB_LEN(x) (x->subend - x->subpointer)

#ifdef CURL_DISABLE_VERBOSE_STRINGS
#define printoption(a,b,c,d)  do { } while(0)
#endif

#ifdef USE_WINSOCK
typedef FARPROC WSOCK2_FUNC;
static CURLcode check_wsock2 ( struct SessionHandle *data );
#endif

static
void telrcv(struct connectdata *,
            const unsigned char *inbuf, /* Data received from socket */
            ssize_t count);             /* Number of bytes received */

#ifndef CURL_DISABLE_VERBOSE_STRINGS
static void printoption(struct SessionHandle *data,
                        const char *direction,
                        int cmd, int option);
#endif

static void negotiate(struct connectdata *);
static void send_negotiation(struct connectdata *, int cmd, int option);
static void set_local_option(struct connectdata *, int cmd, int option);
static void set_remote_option(struct connectdata *, int cmd, int option);

static void printsub(struct SessionHandle *data,
                     int direction, unsigned char *pointer,
                     size_t length);
static void suboption(struct connectdata *);

static CURLcode telnet_do(struct connectdata *conn, bool *done);
static CURLcode telnet_done(struct connectdata *conn,
                                 CURLcode, bool premature);

/* For negotiation compliant to RFC 1143 */
#define CURL_NO          0
#define CURL_YES         1
#define CURL_WANTYES     2
#define CURL_WANTNO      3

#define CURL_EMPTY       0
#define CURL_OPPOSITE    1

/*
 * Telnet receiver states for fsm
 */
typedef enum
{
   CURL_TS_DATA = 0,
   CURL_TS_IAC,
   CURL_TS_WILL,
   CURL_TS_WONT,
   CURL_TS_DO,
   CURL_TS_DONT,
   CURL_TS_CR,
   CURL_TS_SB,   /* sub-option collection */
   CURL_TS_SE   /* looking for sub-option end */
} TelnetReceive;

struct TELNET {
  int please_negotiate;
  int already_negotiated;
  int us[256];
  int usq[256];
  int us_preferred[256];
  int him[256];
  int himq[256];
  int him_preferred[256];
  char subopt_ttype[32];             /* Set with suboption TTYPE */
  char subopt_xdisploc[128];          /* Set with suboption XDISPLOC */
  struct curl_slist *telnet_vars; /* Environment variables */

  /* suboptions */
  unsigned char subbuffer[SUBBUFSIZE];
  unsigned char *subpointer, *subend;      /* buffer for sub-options */

  TelnetReceive telrcv_state;
};


/*
 * TELNET protocol handler.
 */

const struct Curl_handler Curl_handler_telnet = {
  "TELNET",                             /* scheme */
  ZERO_NULL,                            /* setup_connection */
  telnet_do,                            /* do_it */
  telnet_done,                          /* done */
  ZERO_NULL,                            /* do_more */
  ZERO_NULL,                            /* connect_it */
  ZERO_NULL,                            /* connecting */
  ZERO_NULL,                            /* doing */
  ZERO_NULL,                            /* proto_getsock */
  ZERO_NULL,                            /* doing_getsock */
  ZERO_NULL,                            /* disconnect */
  PORT_TELNET,                          /* defport */
  PROT_TELNET                           /* protocol */
};


#ifdef USE_WINSOCK
static CURLcode