104 lines
2.2 KiB
Groff
104 lines
2.2 KiB
Groff
.\" @(#)bindresvport.3n 2.2 88/08/02 4.0 RPCSRC; from 1.7 88/03/14 SMI
|
|
.\" $NetBSD: bindresvport.3,v 1.7 2000/01/26 13:20:25 itojun Exp $
|
|
.\"
|
|
.Dd November 22, 1987
|
|
.Dt BINDRESVPORT 3
|
|
.Os
|
|
.Sh NAME
|
|
.Nm bindresvport ,
|
|
.Nm bindresvport_sa
|
|
.Nd bind a socket to a privileged IP port
|
|
.Sh LIBRARY
|
|
.Lb libc
|
|
.Sh SYNOPSIS
|
|
.Fd #include <sys/types.h>
|
|
.Fd #include <rpc/rpc.h>
|
|
.Ft int
|
|
.Fn bindresvport "int sd" "struct sockaddr_in *sin"
|
|
.Ft int
|
|
.Fn bindresvport_sa "int sd" "struct sockaddr *sa"
|
|
.Sh DESCRIPTION
|
|
.Fn bindresvport
|
|
and
|
|
.Fn bindresvport_sa
|
|
are used to bind a socket descriptor to a privileged
|
|
.Tn IP
|
|
port, that is, a
|
|
port number in the range 0-1023.
|
|
The routine returns 0 if it is successful,
|
|
otherwise -1 is returned and
|
|
.Va errno
|
|
set to reflect the cause of the error.
|
|
.Pp
|
|
If
|
|
.Fa sin
|
|
is a pointer to a
|
|
.Ft "struct sockaddr_in"
|
|
then the appropriate fields in the structure should be defined.
|
|
Note that
|
|
.Fa sin->sin_family
|
|
must be initialized to the address family of the socket, passed by
|
|
.Fa sd .
|
|
If
|
|
.Fa sin->sin_port
|
|
is
|
|
.Sq 0
|
|
then an anonymous port (in the range 600-1023) will be
|
|
chosen, and if
|
|
.Xr bind 2
|
|
is successful, the
|
|
.Fa sin->sin_port
|
|
will be updated to contain the allocated port.
|
|
.Pp
|
|
If
|
|
.Fa sin
|
|
is the
|
|
.Dv NULL
|
|
pointer,
|
|
an anonymous port will be allocated (as above).
|
|
However, there is no way for
|
|
.Fn bindresvport
|
|
to return the allocated port in this case.
|
|
.Pp
|
|
Only root can bind to a privileged port; this call will fail for any
|
|
other users.
|
|
.Pp
|
|
Function prototype of
|
|
.Fn bindresvport
|
|
is biased to
|
|
.Dv AF_INET
|
|
socket.
|
|
.Fn bindresvport_sa
|
|
acts exactly the same, with more neutral function prototype.
|
|
Note that both functions behave exactly the same, and
|
|
both support
|
|
.Dv AF_INET6
|
|
sockets as well as
|
|
.Dv AF_INET
|
|
sockets.
|
|
.Sh RETURN VALUES
|
|
If the bind is successful, a 0 value is returned.
|
|
A return value of -1 indicates an error, which is
|
|
further specified in the global
|
|
.Va errno .
|
|
.Sh ERRORS
|
|
.Bl -tag -width Er
|
|
.It Bq Er EPFNOSUPPORT
|
|
If second argument was supplied,
|
|
and address family did not match between arguments.
|
|
.El
|
|
.Pp
|
|
.Fn bindresvport
|
|
may also fail and set
|
|
.Va errno
|
|
for any of the errors specified for the calls
|
|
.Xr bind 2 ,
|
|
.Xr getsockopt 2 ,
|
|
or
|
|
.Xr setsockopt 2 .
|
|
.Sh SEE ALSO
|
|
.Xr bind 2 ,
|
|
.Xr getsockopt 2 ,
|
|
.Xr setsockopt 2 ,
|
|
.Xr ip 4 .
|