sane-project-backends/sanei/sanei_tcp.c

/* sane - Scanner Access Now Easy.
   Copyright (C) 2006 Tower Technologies
   Author: Alessandro Zummo <a.zummo@towertech.it>
   This file is part of the SANE package.

   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   This program 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
   General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330, Boston,
   MA 02111-1307, USA.

   As a special exception, the authors of SANE give permission for
   additional uses of the libraries contained in this release of SANE.

   The exception is that, if you link a SANE library with other files
   to produce an executable, this does not by itself cause the
   resulting executable to be covered by the GNU General Public
   License.  Your use of that executable is in no way restricted on
   account of linking the SANE library code into it.

   This exception does not, however, invalidate any other reasons why
   the executable file might be covered by the GNU General Public
   License.

   If you submit changes to SANE to the maintainers to be included in
   a subsequent release, you agree by submitting the changes that
   those changes may be distributed with this exception intact.

   If you write modifications of your own for SANE, it is your choice
   whether to permit this exception to apply to your modifications.
   If you do not wish that, delete this exception notice.  */

#include "../include/sane/config.h"

#include <errno.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>

#ifndef SSIZE_MAX
#define SSIZE_MAX LONG_MAX
#endif

#ifdef HAVE_WINSOCK2_H
#include <winsock2.h>
#endif
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif

#define BACKEND_NAME sanei_tcp

#include "../include/sane/sane.h"
#include "../include/sane/sanei_debug.h"
#include "../include/sane/sanei_tcp.h"

SANE_Status
sanei_tcp_open(const char *host, int port, int *fdp)
{
	int fd, err;
	struct sockaddr_in saddr;
	struct hostent *h;
#ifdef HAVE_WINSOCK2_H
	WSADATA wsaData;
#endif

	DBG_INIT();
	DBG(1, "%s: host = %s, port = %d\n", __func__, host, port);

#ifdef HAVE_WINSOCK2_H
	err = WSAStartup(MAKEWORD(2, 2), &wsaData);
	if (err != 0)
	    return SANE_STATUS_INVAL;
#endif

	h = gethostbyname(host);

	if (h == NULL || h->h_addr_list[0] == NULL
	    || h->h_addrtype != AF_INET)
		return SANE_STATUS_INVAL;

	if ((fd = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
		return SANE_STATUS_INVAL;

	memset(&saddr, 0x00, sizeof(struct sockaddr_in));

	saddr.sin_family = AF_INET;
	saddr.sin_port = htons(port);
	memcpy(&saddr.sin_addr, h->h_addr_list[0], h->h_length);

	if ((err =
	     connect(fd, (struct sockaddr *) &saddr,
		     sizeof(struct sockaddr_in))) != 0) {
		close(fd);
		return SANE_STATUS_INVAL;
	}

	*fdp = fd;

	return SANE_STATUS_GOOD;
}

void
sanei_tcp_close(int fd)
{
	close(fd);
#ifdef HAVE_WINSOCK2_H
	WSACleanup();
#endif
}

ssize_t
sanei_tcp_write(int fd, const u_char * buf, size_t count)
{
	return send(fd, buf, count, 0);
}

ssize_t
sanei_tcp_read(int fd, u_char * buf, size_t count)
{
	size_t bytes_recv = 0;
	ssize_t rc = 1;

	if (count > SSIZE_MAX) {
		errno = EINVAL;
		return -1;
	}

	while (bytes_recv < count && rc > 0)
	{
		rc = recv(fd, buf+bytes_recv, count-bytes_recv, 0);
		if (rc > 0)
		  bytes_recv += rc;

	}
	return bytes_recv;
}