/*

 * Copyright (C) 2010-2016 Free Software Foundation, Inc.

 * Copyright (C) 2015-2016 Red Hat, 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/>

 *

 */

#include <config.h>

#include <system.h>

#include "gnutls_int.h"

#include "errors.h"

#include <sys/socket.h>

#include <errno.h>

#include <sys/stat.h>

#include <sys/types.h>

#ifdef _WIN32

# include <windows.h>

#else /* !_WIN32 */

# include <poll.h>

#endif

/* System specific socket function wrappers.

 */

#ifdef _WIN32

/* Do not use the gnulib functions for sending and receiving data.

 * Using them makes gnutls only working with gnulib applications.

 */

#undef send

#undef recv

#undef select

int system_errno(gnutls_transport_ptr p)

{

	int tmperr = WSAGetLastError();

	int ret = 0;

	switch (tmperr) {

	case WSAEWOULDBLOCK:

		ret = EAGAIN;

		break;

	case NO_ERROR:

		ret = 0;

		break;

	case WSAEINTR:

		ret = EINTR;

		break;

	case WSAEMSGSIZE:

		ret = EMSGSIZE;

		break;

	default:

		ret = EIO;

		break;

	}

	WSASetLastError(tmperr);

	return ret;

}

ssize_t

system_write(gnutls_transport_ptr ptr, const void *data, size_t data_size)

{

	return send(GNUTLS_POINTER_TO_INT(ptr), data, data_size, 0);

}

#else				/* POSIX */

int system_errno(gnutls_transport_ptr_t ptr)

{

#if defined(_AIX) || defined(AIX)

	if (errno == 0)

		errno = EAGAIN;

#endif

	return errno;

}

static ssize_t

_system_writev(gnutls_transport_ptr_t ptr, const giovec_t * iovec,

	      int iovec_cnt, int flags)

{

	struct msghdr hdr;

	memset(&hdr, 0, sizeof(hdr));

	hdr.msg_iov = (struct iovec *)iovec;

	hdr.msg_iovlen = iovec_cnt;

	return sendmsg(GNUTLS_POINTER_TO_INT(ptr), &hdr, flags);

}

#ifdef MSG_NOSIGNAL

ssize_t

system_writev_nosignal(gnutls_transport_ptr_t ptr, const giovec_t * iovec,

	      int iovec_cnt)

{

	return _system_writev(ptr, iovec, iovec_cnt, MSG_NOSIGNAL);

}

#endif

ssize_t

system_writev(gnutls_transport_ptr_t ptr, const giovec_t * iovec,

	      int iovec_cnt)

{

	return _system_writev(ptr, iovec, iovec_cnt, 0);

}

#endif

ssize_t

system_read(gnutls_transport_ptr_t ptr, void *data, size_t data_size)

{

	return recv(GNUTLS_POINTER_TO_INT(ptr), data, data_size, 0);

}

/**

 * gnutls_system_recv_timeout:

 * @ptr: A file descriptor (wrapped in a gnutls_transport_ptr_t pointer)

 * @ms: The number of milliseconds to wait.

 *

 * Wait for data to be received from the provided socket (@ptr) within a

 * timeout period in milliseconds, using select() on the provided @ptr.

 *

 * This function is provided as a helper for constructing custom

 * callbacks for gnutls_transport_set_pull_timeout_function(),

 * which can be used if you rely on socket file descriptors.

 *

 * Returns -1 on error, 0 on timeout, positive value if data are available for reading.

 *

 * Since: 3.4.0

 **/

int gnutls_system_recv_timeout(gnutls_transport_ptr_t ptr, unsigned int ms)

{

	int ret;

	int fd = GNUTLS_POINTER_TO_INT(ptr);

#ifndef _WIN32

	int timeo;

	struct pollfd pfd;

	pfd.fd = fd;

	pfd.events = POLLIN;

	pfd.revents = 0;

	if (ms == GNUTLS_INDEFINITE_TIMEOUT)

		timeo = -1;

	else

		timeo = ms;

	do {

		ret = poll(&pfd, 1, timeo);

	} while(ret == -1 && errno == EINTR);

#else

	fd_set rfds;

	struct timeval _tv, *tv = NULL;

	FD_ZERO(&rfds);

	FD_SET(fd, &rfds);

	if (ms != GNUTLS_INDEFINITE_TIMEOUT) {

		_tv.tv_sec = ms/1000;

		_tv.tv_usec = (ms % 1000) * 1000;

		tv = &_tv;

	}

	ret = select(fd + 1, &rfds, NULL, NULL, tv);

#endif

	if (ret <= 0)

		return ret;

	return ret;

}