/*

 * Copyright (C) 2000-2012 Free Software Foundation, Inc.

 *

 * Author: Nikos Mavrogiannopoulos

 *

 * This file is part of GnuTLS.

 *

 * The GnuTLS is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public License

 * as published by the Free Software Foundation; either version 2.1 of

 * the License, or (at your option) any later version.

 *

 * This library is distributed in the hope that it will be useful, but

 * WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public License

 * along with this program.  If not, see <https://www.gnu.org/licenses/>

 *

 */

/* This file contains function that will override the 

 * default berkeley sockets API per session.

 */

#include "gnutls_int.h"

#include "errors.h"

#include "num.h"

#include "record.h"

#include "buffers.h"

#include "mbuffers.h"

#include "state.h"

#include "dtls.h"

#include "system.h"

#include <errno.h>

#ifdef _WIN32

#include <windows.h>

#endif

/**

 * gnutls_transport_set_errno:

 * @session: is a #gnutls_session_t type.

 * @err: error value to store in session-specific errno variable.

 *

 * Store @err in the session-specific errno variable.  Useful values

 * for @err are EINTR, EAGAIN and EMSGSIZE, other values are treated will be

 * treated as real errors in the push/pull function.

 *

 * This function is useful in replacement push and pull functions set by

 * gnutls_transport_set_push_function() and

 * gnutls_transport_set_pull_function() under Windows, where the

 * replacements may not have access to the same @errno

 * variable that is used by GnuTLS (e.g., the application is linked to

 * msvcr71.dll and gnutls is linked to msvcrt.dll).

 *

 * This function is unreliable if you are using the same

 * @session in different threads for sending and receiving.

 *

 **/

void gnutls_transport_set_errno(gnutls_session_t session, int err)

{

  session->internals.errnum = err;

}

/**

 * gnutls_transport_set_pull_function:

 * @session: is a #gnutls_session_t type.

 * @pull_func: a callback function similar to read()

 *

 * This is the function where you set a function for gnutls to receive

 * data.  Normally, if you use berkeley style sockets, do not need to

 * use this function since the default recv(2) will probably be ok.

 * The callback should return 0 on connection termination, a positive

 * number indicating the number of bytes received, and -1 on error.

 *

 * @gnutls_pull_func is of the form,

 * ssize_t (*gnutls_pull_func)(gnutls_transport_ptr_t, void*, size_t);

 **/

void gnutls_transport_set_pull_function(gnutls_session_t session,

          gnutls_pull_func pull_func)

{

  session->internals.pull_func = pull_func;

}

/**

 * gnutls_transport_set_pull_timeout_function:

 * @session: is a #gnutls_session_t type.

 * @func: a callback function

 *

 * This is the function where you set a function for gnutls to know

 * whether data are ready to be received. It should wait for data a

 * given time frame in milliseconds. The callback should return 0 on 

 * timeout, a positive number if data can be received, and -1 on error.

 * You'll need to override this function if select() is not suitable

 * for the provided transport calls.

 *

 * As with select(), if the timeout value is zero the callback should return

 * zero if no data are immediately available. The special value

 * %GNUTLS_INDEFINITE_TIMEOUT indicates that the callback should wait indefinitely

 * for data.

 *

 * @gnutls_pull_timeout_func is of the form,

 * int (*gnutls_pull_timeout_func)(gnutls_transport_ptr_t, unsigned int ms);

 *

 * This callback is necessary when gnutls_handshake_set_timeout() or 

 * gnutls_record_set_timeout() are set, under TLS1.3 and for enforcing the DTLS

 * mode timeouts when in blocking mode.

 *

 * For compatibility with future GnuTLS versions this callback must be set when

 * a custom pull function is registered. The callback will not be used when the

 * session is in TLS mode with non-blocking sockets. That is, when %GNUTLS_NONBLOCK

 * is specified for a TLS session in gnutls_init().

 *

 * The helper function gnutls_system_recv_timeout() is provided to

 * simplify writing callbacks. 

 *

 * Since: 3.0

 **/

void gnutls_transport_set_pull_timeout_function(gnutls_session_t session,

            gnutls_pull_timeout_func func)

{

  session->internals.pull_timeout_func = func;

}

/**

 * gnutls_transport_set_push_function:

 * @session: is a #gnutls_session_t type.

 * @push_func: a callback function similar to write()

 *

 * This is the function where you set a push function for gnutls to

 * use in order to send data.  If you are going to use berkeley style

 * sockets, you do not need to use this function since the default

 * send(2) will probably be ok.  Otherwise you should specify this

 * function for gnutls to be able to send data.

 * The callback should return a positive number indicating the

 * bytes sent, and -1 on error.

 *

 * @push_func is of the form,

 * ssize_t (*gnutls_push_func)(gnutls_transport_ptr_t, const void*, size_t);

 *

 **/

void gnutls_transport_set_push_function(gnutls_session_t session,

          gnutls_push_func push_func)

{

  session->internals.push_func = push_func;

  session->internals.vec_push_func = NULL;

}

/**

 * gnutls_transport_set_vec_push_function:

 * @session: is a #gnutls_session_t type.

 * @vec_func: a callback function similar to writev()

 *

 * Using this function you can override the default writev(2)

 * function for gnutls to send data. Setting this callback 

 * instead of gnutls_transport_set_push_function() is recommended

 * since it introduces less overhead in the TLS handshake process.

 *

 * @vec_func is of the form,

 * ssize_t (*gnutls_vec_push_func) (gnutls_transport_ptr_t, const giovec_t * iov, int iovcnt);

 *

 * Since: 2.12.0

 **/

void gnutls_transport_set_vec_push_function(gnutls_session_t session,

              gnutls_vec_push_func vec_func)

{

  session->internals.push_func = NULL;

  session->internals.vec_push_func = vec_func;

}

/**

 * gnutls_transport_set_errno_function:

 * @session: is a #gnutls_session_t type.

 * @errno_func: a callback function similar to write()

 *

 * This is the function where you set a function to retrieve errno

 * after a failed push or pull operation.

 *

 * @errno_func is of the form,

 * int (*gnutls_errno_func)(gnutls_transport_ptr_t);

 * and should return the errno.

 *

 * Since: 2.12.0

 **/

void gnutls_transport_set_errno_function(gnutls_session_t session,

           gnutls_errno_func errno_func)

{

  session->internals.errno_func = errno_func;

}