BINDRESVPORT(3)           OpenBSD Programmer's Manual          BINDRESVPORT(3)

NAME
     bindresvport - bind a socket to a privileged IP port



SYNOPSIS
     #include <sys/types.h>
     #include <netinet/in.h>

     int
     bindresvport(int sd, struct sockaddr_in *sin);

DESCRIPTION
     bindresvport() is used to bind a socket descriptor to a privileged IP
     port, that is, a port number in the range 0-1023.  sd is a socket de-
     scriptor that was returned by a call to socket(2).

     Only root can bind to a privileged port; this call will fail for any oth-
     er users.

     If the value of sin->sin_port is non-zero, bindresvport() attempts to use
     the specified port.  If that fails, it chooses another privileged port
     number automatically.

RETURN VALUES
     bindresvport() returns 0 if it is successful, otherwise -1 is returned
     and errno set to reflect the cause of the error.

ERRORS
     The bindresvport() function fails if:

     [EBADF]       sd is not a valid descriptor.

     [ENOTSOCK]    sd is not a socket.

     [EADDRNOTAVAIL]
                   The specified address is not available from the local ma-
                   chine.

     [EADDRINUSE]  The specified address is already in use.

     [EINVAL]      The socket is already bound to an address.

     [EACCES]      The requested address is protected, and the current user
                   has inadequate permission to access it.

     [EFAULT]      The name parameter is not in a valid part of the user ad-
                   dress space.

     [ENOBUFS]     Insufficient resources were available in the system to per-
                   form the operation.

     [EPFNOSUPPORT]
                   The protocol family has not been configured into the system
                   or no implementation for it exists.

SEE ALSO
     bind(2),  socket(2),  rresvport(3)

OpenBSD 2.6                     August 9, 1997                               1