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
  48 #if 0
  49 int
  50 rresvport(int *alport)
  51 {
  52         return rresvport_af(alport, AF_INET);
  53 }
  54 #endif
  55
  56 int
  57 rresvport_af(int *alport, sa_family_t af)
  58 {
  59         struct sockaddr_storage ss;
  60         struct sockaddr *sa;
  61         u_int16_t *portp;
  62         int s;
  63         socklen_t salen;
  64
  65         memset(&ss, '\0', sizeof ss);
  66         sa = (struct sockaddr *)&ss;
  67
  68         switch (af) {
  69         case AF_INET:
  70                 salen = sizeof(struct sockaddr_in);
  71                 portp = &((struct sockaddr_in *)sa)->sin_port;
  72                 break;
  73         case AF_INET6:
  74                 salen = sizeof(struct sockaddr_in6);
  75                 portp = &((struct sockaddr_in6 *)sa)->sin6_port;
  76                 break;
  77         default:
  78                 errno = EPFNOSUPPORT;
  79                 return (-1);
  80         }
  81         sa->sa_family = af;
  82
  83         s = socket(af, SOCK_STREAM, 0);
  84         if (s < 0)
  85                 return (-1);
  86
  87         *portp = htons(*alport);
  88         if (*alport < IPPORT_RESERVED - 1) {
  89                 if (bind(s, sa, salen) >= 0)
  90                         return (s);
  91                 if (errno != EADDRINUSE) {
  92                         (void)close(s);
  93                         return (-1);
  94                 }
  95         }
  96
  97         *portp = 0;
  98         sa->sa_family = af;
  99         if (bindresvport_sa(s, sa) == -1) {
 100                 (void)close(s);
 101                 return (-1);
 102         }
 103         *alport = ntohs(*portp);
 104         return (s);
 105 }
 106
 107 #endif /* HAVE_RRESVPORT_AF */