sunrpc/bindrsvprt.c

   1 static  char sccsid[] = "@(#)bindresvport.c     2.2 88/07/29 4.0 RPCSRC 1.8 88/02/08 SMI";
   2 /*
   3  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
   4  * unrestricted use provided that this legend is included on all tape
   5  * media and as a part of the software program in whole or part.  Users
   6  * may copy or modify Sun RPC without charge, but are not authorized
   7  * to license or distribute it to anyone else except as part of a product or
   8  * program developed by the user.
   9  *
  10  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
  11  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
  12  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
  13  *
  14  * Sun RPC is provided with no support and without any obligation on the
  15  * part of Sun Microsystems, Inc. to assist in its use, correction,
  16  * modification or enhancement.
  17  *
  18  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
  19  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
  20  * OR ANY PART THEREOF.
  21  *
  22  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
  23  * or profits or other special, indirect and consequential damages, even if
  24  * Sun has been advised of the possibility of such damages.
  25  *
  26  * Sun Microsystems, Inc.
  27  * 2550 Garcia Avenue
  28  * Mountain View, California  94043
  29  */
  30
  31 /*
  32  * Copyright (c) 1987 by Sun Microsystems, Inc.
  33  */
  34
  35 #include <sys/types.h>
  36 #include <sys/errno.h>
  37 #include <sys/socket.h>
  38 #include <netinet/in.h>
  39
  40 /*
  41  * Bind a socket to a privileged IP port
  42  */
  43 bindresvport(sd, sin)
  44         int sd;
  45         struct sockaddr_in *sin;
  46 {
  47         int res;
  48         static short port;
  49         struct sockaddr_in myaddr;
  50         extern int errno;
  51         int i;
  52
  53 #define STARTPORT 600
  54 #define ENDPORT (IPPORT_RESERVED - 1)
  55 #define NPORTS  (ENDPORT - STARTPORT + 1)
  56
  57         if (sin == (struct sockaddr_in *)0) {
  58                 sin = &myaddr;
  59                 bzero(sin, sizeof (*sin));
  60                 sin->sin_family = AF_INET;
  61         } else if (sin->sin_family != AF_INET) {
  62                 errno = EPFNOSUPPORT;
  63                 return (-1);
  64         }
  65         if (port == 0) {
  66                 port = (getpid() % NPORTS) + STARTPORT;
  67         }
  68         res = -1;
  69         errno = EADDRINUSE;
  70         for (i = 0; i < NPORTS && res < 0 && errno == EADDRINUSE; i++) {
  71                 sin->sin_port = htons(port++);
  72                 if (port > ENDPORT) {
  73                         port = STARTPORT;
  74                 }
  75                 res = bind(sd, sin, sizeof(struct sockaddr_in));
  76         }
  77         return (res);
  78 }