bindresvport.c

/* lib/rpc/bindresvport.c */
/*
 * Copyright (c) 2010, Oracle America, Inc.
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in
 *       the documentation and/or other materials provided with the
 *       distribution.
 *
 *     * Neither the name of the "Oracle America, Inc." nor the names of
 *       its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <string.h>
#include <stdlib.h>
#include <stdint.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/errno.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <gssrpc/rpc.h>
#include <errno.h>
#include "socket-utils.h"

/*
 * Bind a socket to a privileged IP port
 */
int
bindresvport_sa(int sd, struct sockaddr *sa)
{
	int res;
	static short port;
	struct sockaddr_storage myaddr;
	socklen_t salen;
	int i;

#define STARTPORT 600
#define ENDPORT (IPPORT_RESERVED - 1)
#define NPORTS	(ENDPORT - STARTPORT + 1)
	if (sa == NULL) {
		salen = sizeof(myaddr);
		sa = ss2sa(&myaddr);
		res = getsockname(sd, sa, &salen);
		if (res < 0)
			return (-1);
	}
	if (!sa_is_inet(sa)) {
		errno = EPFNOSUPPORT;
		return (-1);
	}
	if (port == 0) {
		port = (getpid() % NPORTS) + STARTPORT;
	}
	res = -1;
	errno = EADDRINUSE;
	for (i = 0; i < NPORTS && res < 0 && errno == EADDRINUSE; i++) {
		sa_setport(sa, port++);
		if (port > ENDPORT) {
			port = STARTPORT;
		}
		res = bind(sd, sa, sa_socklen(sa));
	}
	return (res);
}

int
bindresvport(int sd, struct sockaddr_in *sockin)
{
	return (bindresvport_sa(sd, (struct sockaddr *)sockin));
}