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/*
* 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;
}
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