/*	$Id: compat-setresgid.c,v 1.3 2016/05/19 12:52:43 kristaps Exp $ */
/*
 * Copyright (c) 2016 Kristaps Dzonsons <kristaps@bsd.lv>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHORS DISCLAIM ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include <sys/types.h>

#include <assert.h>
#include <err.h>
#include <unistd.h>

int
setresgid(gid_t rgid, gid_t egid, gid_t sgid)
{

	/* All we accept. */
	assert(rgid == egid && egid == sgid);

#if defined(__APPLE__) || defined(__linux__)
	if (-1 == setregid(egid, egid)) {
		warn("setregid");
		return(-1);
	}
#else
	if (-1 == setegid(egid)) {
		warn("setegid");
		return(-1);
	} else if (-1 == setgid(rgid)) {
		warn("setgid");
		return(-1);
	}
#endif

	return(0);
}