bindresvport, bindresvport_sa - bind a socket to a privileged IP port
bindresvport(int sd, struct sockaddr_in *sin);
bindresvport_sa(int sd, struct sockaddr *sa);
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. The bindresvport() function operates solely
sockets, whereas the bindresvport_sa() function is capable
both AF_INET and AF_INET6 sockets.
Only the superuser may bind to a privileged port; these
fail for any other user.
sd should be a socket descriptor that was returned by a call
If sin is not the NULL pointer, sin->sin_family must be initialized to
the address family of the socket sd. If the value of
non-zero, bindresvport() will attempt to use the specified
a free port in the range 600-1023 will be chosen and,
bind(2) succeeds, sin->sin_port will be updated with the
port that was
If sin is the NULL pointer, a free port in the range
600-1023 will be
chosen (as above), but in this case there is no way for
communicate to the caller which port was assigned.
bindresvport() returns 0 if it is successful, otherwise -1
and errno set to reflect the cause of the error.
The bindresvport() function fails if:
[EBADF] sd is not a valid descriptor.
[ENOTSOCK] sd is not a socket.
The specified address is not available from
the local machine.
[EADDRINUSE] The specified address is already in use.
[EINVAL] The socket is already bound to an address.
[EINVAL] The family of the socket and that requested in
sa->sa_family are not equivalent.
[EACCES] The requested address is protected, and the
has inadequate permission to access it.
[EFAULT] The name parameter is not in a valid part of
the user address
[ENOBUFS] Insufficient resources were available in the
system to perform
The protocol family has not been configured
into the system,
no implementation for it exists, or address family did
not match between arguments.
bind(2), socket(2), rresvport(3), rresvport_af(3)
OpenBSD 3.6 August 9, 1997
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