111 lines
3.1 KiB
C
111 lines
3.1 KiB
C
/*
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* Copyright (c) 2010, Oracle America, Inc.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are
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* met:
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*
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* * Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above
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* copyright notice, this list of conditions and the following
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* disclaimer in the documentation and/or other materials
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* provided with the distribution.
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* * Neither the name of the "Oracle America, Inc." nor the names of its
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* contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
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* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
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* GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <errno.h>
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#include <unistd.h>
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#include <string.h>
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#include <sys/types.h>
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#include <sys/socket.h>
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#include <netinet/in.h>
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#include <libc-lock.h>
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/*
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* Locks the static variables in this file.
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*/
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__libc_lock_define_initialized (static, lock);
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/*
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* Bind a socket to a privileged IP port
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*/
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int
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bindresvport (int sd, struct sockaddr_in *sin)
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{
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static short port;
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struct sockaddr_in myaddr;
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int i;
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#define STARTPORT 600
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#define LOWPORT 512
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#define ENDPORT (IPPORT_RESERVED - 1)
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#define NPORTS (ENDPORT - STARTPORT + 1)
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static short startport = STARTPORT;
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if (sin == (struct sockaddr_in *) 0)
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{
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sin = &myaddr;
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memset (sin, 0, sizeof (*sin));
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sin->sin_family = AF_INET;
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}
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else if (sin->sin_family != AF_INET)
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{
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__set_errno (EAFNOSUPPORT);
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return -1;
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}
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if (port == 0)
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{
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port = (__getpid () % NPORTS) + STARTPORT;
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}
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/* Initialize to make gcc happy. */
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int res = -1;
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int nports = ENDPORT - startport + 1;
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int endport = ENDPORT;
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__libc_lock_lock (lock);
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again:
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for (i = 0; i < nports; ++i)
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{
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sin->sin_port = htons (port++);
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if (port > endport)
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port = startport;
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res = __bind (sd, sin, sizeof (struct sockaddr_in));
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if (res >= 0 || errno != EADDRINUSE)
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break;
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}
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if (i == nports && startport != LOWPORT)
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{
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startport = LOWPORT;
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endport = STARTPORT - 1;
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nports = STARTPORT - LOWPORT;
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port = LOWPORT + port % (STARTPORT - LOWPORT);
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goto again;
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}
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__libc_lock_unlock (lock);
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return res;
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}
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libc_hidden_def (bindresvport)
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