/*
 * Venus GPS Server
 *
 * Copyright (C) 2010 by Multi-Tech Systems
 * Copyright (C) 2004-2009 by James Maki
 *
 * Author: James Maki <jmaki@multitech.com>
 *
 * safe_read, safe_write, full_write are from Busybox
 *
 * 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
 *
 */
#define _GNU_SOURCE

#include <string.h>
#include <netdb.h>
#include <fcntl.h>

#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <netinet/udp.h>

#define UDP_CORK	1

#include "log.h"
#include "utils.h"

int systemf(const char *fmt, ...)
{
	int err;
	va_list ap;
	char *buf;

	va_start(ap, fmt);
	err = vasprintf(&buf, fmt, ap);
	va_end(ap);
	if (err == -1) {
		log_error("out of memory");
		return -1;
	}

	log_debug("%s", buf);

	err = system(buf);
	free(buf);

	return err;
}

ssize_t safe_read(int fd, void *buf, size_t count)
{
	ssize_t n;

	do {
		n = read(fd, buf, count);
	} while (n < 0 && errno == EINTR);

	return n;
}

ssize_t safe_readn(int fd, void *buf, size_t len)
{
	ssize_t cc;
	ssize_t total;

	total = 0;

	while (len) {
		cc = safe_read(fd, buf, len);

		if (cc < 0) {
			if (total) {
				return total;
			}
			return cc;
		}

		total += cc;
		buf = buf + cc;
		len -= cc;
	}

	return total;
}

ssize_t safe_write(int fd, const void *buf, size_t count)
{
	ssize_t n;

	do {
		n = write(fd, buf, count);
	} while (n < 0 && errno == EINTR);

	return n;
}

ssize_t full_write(int fd, const void *buf, size_t len)
{
	ssize_t cc;
	ssize_t total;

	total = 0;

	while (len) {
		cc = safe_write(fd, buf, len);

		if (cc < 0) {
			if (total) {
				return total;
			}
			return cc;
		}

		total += cc;
		buf = ((const char *) buf) + cc;
		len -= cc;
	}

	return total;
}

int set_nonblocking(int fd)
{
	int err;

	err = fcntl(fd, F_GETFL, 0);
	if (err < 0) {
		log_warning("fcntl(fd, F_GETFL, 0) failed: %m");
		return err;
	}
	err = fcntl(fd, F_SETFL, err | O_NONBLOCK);
	if (err < 0) {
		log_warning("fcntl(fd, F_SETFL, opts | O_NONBLOCK) failed: %m");
		return err;
	}

	return err;
}

int udp_cork(int fd, int corked)
{
	int tmp;

	tmp = setsockopt(fd, IPPROTO_UDP, UDP_CORK, &corked, sizeof(corked));
	if (tmp < 0) {
		log_error("setsockopt UDP_CORK failed");
	}

	return -1;
}

int tcp_cork(int fd, int corked)
{
	int tmp;

	tmp = setsockopt(fd, IPPROTO_TCP, TCP_CORK, &corked, sizeof(corked));
	if (tmp < 0) {
		log_error("setsockopt TCP_CORK failed");
	}

	return -1;
}

int host_to_inet(const char *host, struct in_addr *in)
{
	struct hostent h;
	struct hostent *hp;
	char buf[1024];
	int herrno;
	int err;

	err = gethostbyname_r(host, &h, buf, sizeof(buf), &hp, &herrno);
	if (hp == NULL) {
		log_error("gethostbyname_r: %d", herrno);
		return -1;
	}

	memcpy(&in->s_addr, h.h_addr_list[0], 4);

	return 0;
}

int inet_conn_str(const char *host, int port, int type)
{
	struct hostent h;
	struct hostent *hp;
	char buf[1024];
	int herrno;
	int err;

	err = gethostbyname_r(host, &h, buf, sizeof(buf), &hp, &herrno);
	if (hp == NULL) {
		log_error("gethostbyname_r: %d", herrno);
		return -1;
	}

	int sd = socket(PF_INET, type, 0);
	if (sd == -1) {
		log_error("socket: %m");
		return -1;
	}

	struct sockaddr_in serv_addr;
	serv_addr.sin_family = AF_INET;
	serv_addr.sin_port = htons(port);
	memcpy(&serv_addr.sin_addr.s_addr, h.h_addr_list[0], 4);

	err = connect(sd, (struct sockaddr *) &serv_addr, sizeof(serv_addr));
	if (err == -1) {
		log_error("connect: %m");
		close(sd);
		return -1;
	}

	return sd;
}

int inet_conn_ia(struct in_addr *host, int port, int type)
{
	int err;

	int sd = socket(PF_INET, type, 0);
	if (sd == -1) {
		log_error("socket: %m");
		return -1;
	}

	struct sockaddr_in serv_addr;
	memset(&serv_addr, 0, sizeof(serv_addr));
	serv_addr.sin_family = AF_INET;
	serv_addr.sin_port = htons(port);
	serv_addr.sin_addr.s_addr = host->s_addr;

	err = connect(sd, (struct sockaddr *) &serv_addr, sizeof(serv_addr));
	if (err == -1) {
		log_error("connect: %m");
		close(sd);
		return -1;
	}

	return sd;
}