/* * 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)