lib/libc/rpc/bindresvport.c

   1 /*-
   2  * Copyright (c) 2009, Sun Microsystems, Inc.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are met:
   7  * - Redistributions of source code must retain the above copyright notice,
   8  *   this list of conditions and the following disclaimer.
   9  * - Redistributions in binary form must reproduce the above copyright notice,
  10  *   this list of conditions and the following disclaimer in the documentation
  11  *   and/or other materials provided with the distribution.
  12  * - Neither the name of Sun Microsystems, Inc. nor the names of its
  13  *   contributors may be used to endorse or promote products derived
  14  *   from this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  17  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
  20  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  26  * POSSIBILITY OF SUCH DAMAGE.
  27  *
  28  * @(#)bindresvport.c 1.8 88/02/08 SMI
  29  * @(#)bindresvport.c   2.2 88/07/29 4.0 RPCSRC
  30  * $NetBSD: bindresvport.c,v 1.19 2000/07/06 03:03:59 christos Exp $
  31  * $FreeBSD: src/lib/libc/rpc/bindresvport.c,v 1.16 2004/10/16 06:11:34 obrien Exp $
  32  */
  33
  34 /*
  35  * Copyright (c) 1987 by Sun Microsystems, Inc.
  36  *
  37  * Portions Copyright(C) 1996, Jason Downs.  All rights reserved.
  38  */
  39
  40 #include "namespace.h"
  41 #include <sys/types.h>
  42 #include <sys/socket.h>
  43
  44 #include <netinet/in.h>
  45
  46 #include <errno.h>
  47 #include <string.h>
  48 #include <unistd.h>
  49
  50 #include <rpc/rpc.h>
  51 #include "un-namespace.h"
  52
  53 /*
  54  * Bind a socket to a privileged IP port
  55  */
  56 int
  57 bindresvport(int sd, struct sockaddr_in *sin)
  58 {
  59         return bindresvport_sa(sd, (struct sockaddr *)sin);
  60 }
  61
  62 /*
  63  * Bind a socket to a privileged IP port
  64  */
  65 int
  66 bindresvport_sa(int sd, struct sockaddr *sa)
  67 {
  68         int old, error, af;
  69         struct sockaddr_storage myaddr;
  70         struct sockaddr_in *sin;
  71 #ifdef INET6
  72         struct sockaddr_in6 *sin6;
  73 #endif
  74         int proto, portrange, portlow;
  75         u_int16_t *portp;
  76         socklen_t salen;
  77
  78         if (sa == NULL) {
  79                 salen = sizeof(myaddr);
  80                 sa = (struct sockaddr *)&myaddr;
  81
  82                 if (_getsockname(sd, sa, &salen) == -1)
  83                         return -1;      /* errno is correctly set */
  84
  85                 af = sa->sa_family;
  86                 memset(sa, 0, salen);
  87         } else
  88                 af = sa->sa_family;
  89
  90         switch (af) {
  91         case AF_INET:
  92                 proto = IPPROTO_IP;
  93                 portrange = IP_PORTRANGE;
  94                 portlow = IP_PORTRANGE_LOW;
  95                 sin = (struct sockaddr_in *)sa;
  96                 salen = sizeof(struct sockaddr_in);
  97                 portp = &sin->sin_port;
  98                 break;
  99 #ifdef INET6
 100         case AF_INET6:
 101                 proto = IPPROTO_IPV6;
 102                 portrange = IPV6_PORTRANGE;
 103                 portlow = IPV6_PORTRANGE_LOW;
 104                 sin6 = (struct sockaddr_in6 *)sa;
 105                 salen = sizeof(struct sockaddr_in6);
 106                 portp = &sin6->sin6_port;
 107                 break;
 108 #endif
 109         default:
 110                 errno = EPFNOSUPPORT;
 111                 return (-1);
 112         }
 113         sa->sa_family = af;
 114         sa->sa_len = salen;
 115
 116         if (*portp == 0) {
 117                 socklen_t oldlen = sizeof(old);
 118
 119                 error = _getsockopt(sd, proto, portrange, &old, &oldlen);
 120                 if (error < 0)
 121                         return (error);
 122
 123                 error = _setsockopt(sd, proto, portrange, &portlow,
 124                     sizeof(portlow));
 125                 if (error < 0)
 126                         return (error);
 127         }
 128
 129         error = _bind(sd, sa, salen);
 130
 131         if (*portp == 0) {
 132                 int saved_errno = errno;
 133
 134                 if (error < 0) {
 135                         if (_setsockopt(sd, proto, portrange, &old,
 136                             sizeof(old)) < 0)
 137                                 errno = saved_errno;
 138                         return (error);
 139                 }
 140
 141                 if (sa != (struct sockaddr *)&myaddr) {
 142                         /* Hmm, what did the kernel assign? */
 143                         if (_getsockname(sd, sa, &salen) < 0)
 144                                 errno = saved_errno;
 145                         return (error);
 146                 }
 147         }
 148         return (error);
 149 }