lib/libc/rpc/bindresvport.c

   1 /*
   2  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
   3  * unrestricted use provided that this legend is included on all tape
   4  * media and as a part of the software program in whole or part.  Users
   5  * may copy or modify Sun RPC without charge, but are not authorized
   6  * to license or distribute it to anyone else except as part of a product or
   7  * program developed by the user.
   8  *
   9  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
  10  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
  11  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
  12  *
  13  * Sun RPC is provided with no support and without any obligation on the
  14  * part of Sun Microsystems, Inc. to assist in its use, correction,
  15  * modification or enhancement.
  16  *
  17  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
  18  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
  19  * OR ANY PART THEREOF.
  20  *
  21  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
  22  * or profits or other special, indirect and consequential damages, even if
  23  * Sun has been advised of the possibility of such damages.
  24  *
  25  * Sun Microsystems, Inc.
  26  * 2550 Garcia Avenue
  27  * Mountain View, California  94043
  28  *
  29  * @(#)bindresvport.c 1.8 88/02/08 SMI
  30  * @(#)bindresvport.c   2.2 88/07/29 4.0 RPCSRC
  31  * $FreeBSD: src/lib/libc/rpc/bindresvport.c,v 1.12 2000/01/26 09:02:42 shin Exp $
  32  * $DragonFly: src/lib/libc/rpc/bindresvport.c,v 1.4 2005/11/13 12:27:04 swildner Exp $
  33  */
  34
  35 /*
  36  * Copyright (c) 1987 by Sun Microsystems, Inc.
  37  *
  38  * Portions Copyright(C) 1996, Jason Downs.  All rights reserved.
  39  */
  40
  41 #include "namespace.h"
  42 #include <sys/types.h>
  43 #include <sys/errno.h>
  44 #include <sys/socket.h>
  45 #include <netinet/in.h>
  46 #include <unistd.h>
  47 #include <string.h>
  48 #include "un-namespace.h"
  49
  50 /*
  51  * Bind a socket to a privileged IP port
  52  */
  53 int
  54 bindresvport(int sd, struct sockaddr_in *sin)
  55 {
  56         return bindresvport_sa(sd, (struct sockaddr *)sin);
  57 }
  58
  59 /*
  60  * Bind a socket to a privileged port for whatever protocol.
  61  */
  62 int
  63 bindresvport_sa(int sd, struct sockaddr *sa)
  64 {
  65         int old, error, af;
  66         struct sockaddr_storage myaddr;
  67         struct sockaddr_in *sin;
  68         struct sockaddr_in6 *sin6;
  69         int proto, portrange, portlow;
  70         u_int16_t port;
  71         int salen;
  72
  73         if (sa == NULL) {
  74                 salen = sizeof(myaddr);
  75                 sa = (struct sockaddr *)&myaddr;
  76
  77                 if (_getsockname(sd, sa, &salen) == -1)
  78                         return -1;      /* errno is correctly set */
  79
  80                 af = sa->sa_family;
  81                 memset(&myaddr, 0, salen);
  82         } else
  83                 af = sa->sa_family;
  84
  85         if (af == AF_INET) {
  86                 proto = IPPROTO_IP;
  87                 portrange = IP_PORTRANGE;
  88                 portlow = IP_PORTRANGE_LOW;
  89                 sin = (struct sockaddr_in *)sa;
  90                 salen = sizeof(struct sockaddr_in);
  91                 port = sin->sin_port;
  92         } else if (af == AF_INET6) {
  93                 proto = IPPROTO_IPV6;
  94                 portrange = IPV6_PORTRANGE;
  95                 portlow = IPV6_PORTRANGE_LOW;
  96                 sin6 = (struct sockaddr_in6 *)sa;
  97                 salen = sizeof(struct sockaddr_in6);
  98                 port = sin6->sin6_port;
  99         } else {
 100                 errno = EPFNOSUPPORT;
 101                 return (-1);
 102         }
 103         sa->sa_family = af;
 104         sa->sa_len = salen;
 105
 106         if (port == 0) {
 107                 int oldlen = sizeof(old);
 108
 109                 error = _getsockopt(sd, proto, portrange, &old, &oldlen);
 110                 if (error < 0)
 111                         return (error);
 112
 113                 error = setsockopt(sd, proto, portrange, &portlow,
 114                     sizeof(portlow));
 115                 if (error < 0)
 116                         return (error);
 117         }
 118
 119         error = _bind(sd, sa, salen);
 120
 121         if (port == 0) {
 122                 int saved_errno = errno;
 123
 124                 if (error) {
 125                         if (_setsockopt(sd, proto, portrange, &old,
 126                             sizeof(old)) < 0)
 127                                 errno = saved_errno;
 128                         return (error);
 129                 }
 130
 131                 if (sa != (struct sockaddr *)&myaddr) {
 132                         /* Hmm, what did the kernel assign... */
 133                         if (_getsockname(sd, sa, &salen) < 0)
 134                                 errno = saved_errno;
 135                         return (error);
 136                 }
 137         }
 138         return (error);
 139 }