lib/libc/rpc/bindresvport.c

   1 /*      $NetBSD: bindresvport.c,v 1.21 2003/01/18 11:29:03 thorpej Exp $        */
   2
   3 /*
   4  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
   5  * unrestricted use provided that this legend is included on all tape
   6  * media and as a part of the software program in whole or part.  Users
   7  * may copy or modify Sun RPC without charge, but are not authorized
   8  * to license or distribute it to anyone else except as part of a product or
   9  * program developed by the user.
  10  *
  11  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
  12  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
  13  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
  14  *
  15  * Sun RPC is provided with no support and without any obligation on the
  16  * part of Sun Microsystems, Inc. to assist in its use, correction,
  17  * modification or enhancement.
  18  *
  19  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
  20  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
  21  * OR ANY PART THEREOF.
  22  *
  23  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
  24  * or profits or other special, indirect and consequential damages, even if
  25  * Sun has been advised of the possibility of such damages.
  26  *
  27  * Sun Microsystems, Inc.
  28  * 2550 Garcia Avenue
  29  * Mountain View, California  94043
  30  */
  31
  32 #include <sys/cdefs.h>
  33 #if defined(LIBC_SCCS) && !defined(lint)
  34 #if 0
  35 static char *sccsid = "@(#)bindresvport.c 1.8 88/02/08 SMI";
  36 static char *sccsid = "@(#)bindresvport.c       2.2 88/07/29 4.0 RPCSRC";
  37 #else
  38 __RCSID("$NetBSD: bindresvport.c,v 1.21 2003/01/18 11:29:03 thorpej Exp $");
  39 #endif
  40 #endif
  41
  42 /*
  43  * Copyright (c) 1987 by Sun Microsystems, Inc.
  44  */
  45
  46 #include "namespace.h"
  47
  48 #include <sys/types.h>
  49 #include <sys/socket.h>
  50
  51 #include <netinet/in.h>
  52
  53 #include <errno.h>
  54 #include <string.h>
  55 #include <unistd.h>
  56
  57 #include <rpc/rpc.h>
  58
  59 #ifdef __weak_alias
  60 __weak_alias(bindresvport,_bindresvport)
  61 __weak_alias(bindresvport_sa,_bindresvport_sa)
  62 #endif
  63
  64 /*
  65  * Bind a socket to a privileged IP port
  66  */
  67 int
  68 bindresvport(sd, brsin)
  69         int sd;
  70         struct sockaddr_in *brsin;
  71 {
  72         return bindresvport_sa(sd, (struct sockaddr *)(void *)brsin);
  73 }
  74
  75 /*
  76  * Bind a socket to a privileged IP port
  77  */
  78 int
  79 bindresvport_sa(sd, sa)
  80         int sd;
  81         struct sockaddr *sa;
  82 {
  83         int error, old;
  84         struct sockaddr_storage myaddr;
  85         struct sockaddr_in *brsin;
  86 #ifdef INET6
  87         struct sockaddr_in6 *brsin6;
  88 #endif
  89         int proto, portrange, portlow;
  90         u_int16_t *portp;
  91         socklen_t salen;
  92         int af;
  93
  94         if (sa == NULL) {
  95                 salen = sizeof(myaddr);
  96                 sa = (struct sockaddr *)(void *)&myaddr;
  97
  98                 if (getsockname(sd, sa, &salen) == -1)
  99                         return -1;      /* errno is correctly set */
 100
 101                 af = sa->sa_family;
 102                 memset(sa, 0, salen);
 103         } else
 104                 af = sa->sa_family;
 105
 106         switch (af) {
 107         case AF_INET:
 108                 proto = IPPROTO_IP;
 109                 portrange = IP_PORTRANGE;
 110                 portlow = IP_PORTRANGE_LOW;
 111                 brsin = (struct sockaddr_in *)(void *)sa;
 112                 salen = sizeof(struct sockaddr_in);
 113                 portp = &brsin->sin_port;
 114                 break;
 115 #ifdef INET6
 116         case AF_INET6:
 117                 proto = IPPROTO_IPV6;
 118                 portrange = IPV6_PORTRANGE;
 119                 portlow = IPV6_PORTRANGE_LOW;
 120                 brsin6 = (struct sockaddr_in6 *)(void *)sa;
 121                 salen = sizeof(struct sockaddr_in6);
 122                 portp = &brsin6->sin6_port;
 123                 break;
 124 #endif
 125         default:
 126                 errno = EPFNOSUPPORT;
 127                 return (-1);
 128         }
 129         sa->sa_family = af;
 130         sa->sa_len = salen;
 131
 132         if (*portp == 0) {
 133                 socklen_t oldlen = sizeof(old);
 134
 135                 error = getsockopt(sd, proto, portrange, &old, &oldlen);
 136                 if (error < 0)
 137                         return (error);
 138                 error = setsockopt(sd, proto, portrange, &portlow,
 139                     sizeof(portlow));
 140                 if (error < 0)
 141                         return (error);
 142         }
 143
 144         error = bind(sd, sa, salen);
 145
 146         if (*portp == 0) {
 147                 int saved_errno = errno;
 148
 149                 if (error < 0) {
 150                         if (setsockopt(sd, proto, portrange, &old,
 151                             sizeof(old)) < 0)
 152                                 errno = saved_errno;
 153                         return (error);
 154                 }
 155
 156                 if (sa != (struct sockaddr *)(void *)&myaddr) {
 157                         /* What did the kernel assign? */
 158                         if (getsockname(sd, sa, &salen) < 0)
 159                                 errno = saved_errno;
 160                         return (error);
 161                 }
 162         }
 163         return (error);
 164 }