bindresvport.c revision 5d54f3d8999eac1762fe0a8c7177d20f1f201fae
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 1987 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#include <sys/types.h>
#include <errno.h>
#include <sys/socket.h>
#include <netinet/in.h>
/*
* Bind a socket to a privileged IP port
*/
int
bindresvport(int sd, struct sockaddr_in *sin)
{
int res;
static short port;
struct sockaddr_in myaddr;
int i;
#define STARTPORT 600
#define ENDPORT (IPPORT_RESERVED - 1)
#define NPORTS (ENDPORT - STARTPORT + 1)
if (sin == (struct sockaddr_in *)0) {
sin = &myaddr;
bzero(sin, sizeof (*sin));
sin->sin_family = AF_INET;
} else if (sin->sin_family != AF_INET) {
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++) {
sin->sin_port = htons(port++);
if (port > ENDPORT) {
port = STARTPORT;
}
res = bind(sd, sin, sizeof(struct sockaddr_in));
}
return (res);
}