/*
 * Network library.
 * Copyright (C) 1997 Kunihiro Ishiguro
 *
 * This file is part of GNU Zebra.
 *
 * GNU Zebra 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, or (at your option) any
 * later version.
 *
 * GNU Zebra 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; see the file COPYING; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <zebra.h>
#include "log.h"
#include "network.h"
#include "lib_errors.h"

/* Read nbytes from fd and store into ptr. */
int readn(int fd, uint8_t *ptr, int nbytes)
{
	int nleft;
	int nread;

	nleft = nbytes;

	while (nleft > 0) {
		nread = read(fd, ptr, nleft);

		if (nread < 0)
			return (nread);
		else if (nread == 0)
			break;

		nleft -= nread;
		ptr += nread;
	}

	return nbytes - nleft;
}

/* Write nbytes from ptr to fd. */
int writen(int fd, const uint8_t *ptr, int nbytes)
{
	int nleft;
	int nwritten;

	nleft = nbytes;

	while (nleft > 0) {
		nwritten = write(fd, ptr, nleft);

		if (nwritten < 0) {
			if (!ERRNO_IO_RETRY(errno))
				return nwritten;
		}
		if (nwritten == 0)
			return (nwritten);

		nleft -= nwritten;
		ptr += nwritten;
	}
	return nbytes - nleft;
}

int set_nonblocking(int fd)
{
	int flags;

	/* According to the Single UNIX Spec, the return value for F_GETFL
	   should
	   never be negative. */
	if ((flags = fcntl(fd, F_GETFL)) < 0) {
		flog_err(EC_LIB_SYSTEM_CALL,
			 "fcntl(F_GETFL) failed for fd %d: %s", fd,
			 safe_strerror(errno));
		return -1;
	}
	if (fcntl(fd, F_SETFL, (flags | O_NONBLOCK)) < 0) {
		flog_err(EC_LIB_SYSTEM_CALL,
			 "fcntl failed setting fd %d non-blocking: %s", fd,
			 safe_strerror(errno));
		return -1;
	}
	return 0;
}

int set_cloexec(int fd)
{
	int flags;
	flags = fcntl(fd, F_GETFD, 0);
	if (flags == -1)
		return -1;

	flags |= FD_CLOEXEC;
	if (fcntl(fd, F_SETFD, flags) == -1)
		return -1;
	return 0;
}

float htonf(float host)
{
	uint32_t lu1, lu2;
	float convert;

	memcpy(&lu1, &host, sizeof(uint32_t));
	lu2 = htonl(lu1);
	memcpy(&convert, &lu2, sizeof(uint32_t));
	return convert;
}

float ntohf(float net)
{
	return htonf(net);
}

/**
 * Helper function that returns a random long value. The main purpose of
 * this function is to hide a `random()` call that gets flagged by coverity
 * scan and put it into one place.
 *
 * The main usage of this function should be for generating jitter or weak
 * random values for simple purposes.
 *
 * See 'man 3 random' for more information.
 *
 * \returns random long integer.
 */
long frr_weak_random(void)
{
	/* coverity[dont_call] */
	return random();
}