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/*
* Copyright (c) 2010, Oracle America, Inc.
*
* 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 <errno.h>
#include <unistd.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <libc-lock.h>
/*
* Locks the static variables in this file.
*/
__libc_lock_define_initialized (static, lock);
/*
* Bind a socket to a privileged IP port
*/
int
bindresvport (int sd, struct sockaddr_in *sin)
{
static short port;
struct sockaddr_in myaddr;
int i;
#define STARTPORT 600
#define LOWPORT 512
#define ENDPORT (IPPORT_RESERVED - 1)
#define NPORTS (ENDPORT - STARTPORT + 1)
static short startport = STARTPORT;
if (sin == (struct sockaddr_in *) 0)
{
sin = &myaddr;
memset (sin, 0, sizeof (*sin));
sin->sin_family = AF_INET;
}
else if (sin->sin_family != AF_INET)
{
__set_errno (EAFNOSUPPORT);
return -1;
}
if (port == 0)
{
port = (__getpid () % NPORTS) + STARTPORT;
}
/* Initialize to make gcc happy. */
int res = -1;
int nports = ENDPORT - startport + 1;
int endport = ENDPORT;
__libc_lock_lock (lock);
again:
for (i = 0; i < nports; ++i)
{
sin->sin_port = htons (port++);
if (port > endport)
port = startport;
res = __bind (sd, sin, sizeof (struct sockaddr_in));
if (res >= 0 || errno != EADDRINUSE)
break;
}
if (i == nports && startport != LOWPORT)
{
startport = LOWPORT;
endport = STARTPORT - 1;
nports = STARTPORT - LOWPORT;
port = LOWPORT + port % (STARTPORT - LOWPORT);
goto again;
}
__libc_lock_unlock (lock);
return res;
}
libc_hidden_def (bindresvport)
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