openbsd-compat/rresvport.c

   1 /* $OpenBSD: rresvport.c,v 1.9 2005/11/10 10:00:17 espie Exp $ */
   2 /*
   3  * Copyright (c) 1995, 1996, 1998 Theo de Raadt.  All rights reserved.
   4  * Copyright (c) 1983, 1993, 1994
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 /* OPENBSD ORIGINAL: lib/libc/net/rresvport.c */
  33
  34 #include "includes.h"
  35
  36 #ifndef HAVE_RRESVPORT_AF
  37
  38 #include <sys/types.h>
  39 #include <sys/socket.h>
  40
  41 #include <netinet/in.h>
  42 #include <arpa/inet.h>
  43
  44 #include <errno.h>
  45 #include <stdlib.h>
  46 #include <string.h>
  47 #include <unistd.h>
  48
  49 #if 0
  50 int
  51 rresvport(int *alport)
  52 {
  53         return rresvport_af(alport, AF_INET);
  54 }
  55 #endif
  56
  57 int
  58 rresvport_af(int *alport, sa_family_t af)
  59 {
  60         struct sockaddr_storage ss;
  61         struct sockaddr *sa;
  62         u_int16_t *portp;
  63         int s;
  64         socklen_t salen;
  65
  66         memset(&ss, '\0', sizeof ss);
  67         sa = (struct sockaddr *)&ss;
  68
  69         switch (af) {
  70         case AF_INET:
  71                 salen = sizeof(struct sockaddr_in);
  72                 portp = &((struct sockaddr_in *)sa)->sin_port;
  73                 break;
  74         case AF_INET6:
  75                 salen = sizeof(struct sockaddr_in6);
  76                 portp = &((struct sockaddr_in6 *)sa)->sin6_port;
  77                 break;
  78         default:
  79                 errno = EPFNOSUPPORT;
  80                 return (-1);
  81         }
  82         sa->sa_family = af;
  83
  84         s = socket(af, SOCK_STREAM, 0);
  85         if (s < 0)
  86                 return (-1);
  87
  88         *portp = htons(*alport);
  89         if (*alport < IPPORT_RESERVED - 1) {
  90                 if (bind(s, sa, salen) >= 0)
  91                         return (s);
  92                 if (errno != EADDRINUSE) {
  93                         (void)close(s);
  94                         return (-1);
  95                 }
  96         }
  97
  98         *portp = 0;
  99         sa->sa_family = af;
 100         if (bindresvport_sa(s, sa) == -1) {
 101                 (void)close(s);
 102                 return (-1);
 103         }
 104         *alport = ntohs(*portp);
 105         return (s);
 106 }
 107
 108 #endif /* HAVE_RRESVPORT_AF */