openbsd-compat/rresvport.c

   1 /* OPENBSD ORIGINAL: lib/libc/net/rresvport.c */
   2
   3 /*
   4  * Copyright (c) 1995, 1996, 1998 Theo de Raadt.  All rights reserved.
   5  * Copyright (c) 1983, 1993, 1994
   6  *      The Regents of the University of California.  All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the name of the University nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 #include "includes.h"
  34
  35 #ifndef HAVE_RRESVPORT_AF
  36
  37 #if defined(LIBC_SCCS) && !defined(lint)
  38 static char *rcsid = "$OpenBSD: rresvport.c,v 1.6 2003/06/03 02:11:35 deraadt Exp $";
  39 #endif /* LIBC_SCCS and not lint */
  40
  41 #include "includes.h"
  42
  43 #if 0
  44 int
  45 rresvport(alport)
  46         int *alport;
  47 {
  48         return rresvport_af(alport, AF_INET);
  49 }
  50 #endif
  51
  52 int
  53 rresvport_af(int *alport, sa_family_t af)
  54 {
  55         struct sockaddr_storage ss;
  56         struct sockaddr *sa;
  57         u_int16_t *portp;
  58         int s;
  59         socklen_t salen;
  60
  61         memset(&ss, '\0', sizeof ss);
  62         sa = (struct sockaddr *)&ss;
  63
  64         switch (af) {
  65         case AF_INET:
  66                 salen = sizeof(struct sockaddr_in);
  67                 portp = &((struct sockaddr_in *)sa)->sin_port;
  68                 break;
  69         case AF_INET6:
  70                 salen = sizeof(struct sockaddr_in6);
  71                 portp = &((struct sockaddr_in6 *)sa)->sin6_port;
  72                 break;
  73         default:
  74                 errno = EPFNOSUPPORT;
  75                 return (-1);
  76         }
  77         sa->sa_family = af;
  78
  79         s = socket(af, SOCK_STREAM, 0);
  80         if (s < 0)
  81                 return (-1);
  82
  83         *portp = htons(*alport);
  84         if (*alport < IPPORT_RESERVED - 1) {
  85                 if (bind(s, sa, salen) >= 0)
  86                         return (s);
  87                 if (errno != EADDRINUSE) {
  88                         (void)close(s);
  89                         return (-1);
  90                 }
  91         }
  92
  93         *portp = 0;
  94         sa->sa_family = af;
  95         if (bindresvport_sa(s, sa) == -1) {
  96                 (void)close(s);
  97                 return (-1);
  98         }
  99         *alport = ntohs(*portp);
 100         return (s);
 101 }
 102
 103 #endif /* HAVE_RRESVPORT_AF */