BINDRESVPORT(3) 					   BSD Library Functions Manual 					   BINDRESVPORT(3)

NAME

     bindresvport, bindresvport_sa -- bind a socket to a privileged IP port

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <sys/types.h>
     #include <rpc/rpc.h>

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

     int
     bindresvport_sa(int sd, struct sockaddr *sa);

DESCRIPTION

     The bindresvport() and bindresvport_sa() functions are used to bind a socket descriptor to a privileged IP port, that is, a port number in
     the range 0-1023.

     If sin is a pointer to a struct sockaddr_in then the appropriate fields in the structure should be defined.  Note that sin->sin_family must
     be initialized to the address family of the socket, passed by sd.	If sin->sin_port is '0' then an anonymous port (in the range 600-1023)
     will be chosen, and if bind(2) is successful, the sin->sin_port will be updated to contain the allocated port.

     If sin is the NULL pointer, an anonymous port will be allocated (as above).  However, there is no way for bindresvport() to return the allo-
     cated port in this case.

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

     Function prototype of bindresvport() is biased to AF_INET socket.	The bindresvport_sa() function acts exactly the same, with more neutral
     function prototype.  Note that both functions behave exactly the same, and both support AF_INET6 sockets as well as AF_INET sockets.

RETURN VALUES

     The bindresvport() function returns the value 0 if successful; otherwise the value -1 is returned and the global variable errno is set to
     indicate the error.

ERRORS

     [EPFNOSUPPORT]	If second argument was supplied, and address family did not match between arguments.

     The bindresvport() function may also fail and set errno for any of the errors specified for the calls bind(2), getsockopt(2), or
     setsockopt(2).

SEE ALSO

     bind(2), getsockopt(2), setsockopt(2), ip(4)

BSD
								 November 22, 1987							       BSD