getsockopt error

[wferi@niif.hu (Ferenc Wágner)]

Dear Hurd porters,

why does

#include <stdio.h>
#include <sys/socket.h>

int
main (void)
{
	unsigned int optval;
	socklen_t optlen = sizeof optval;
	int rc, s;

	s = socket (AF_UNIX, SOCK_STREAM, 0);
	if (s == -1) {
		perror ("socket");
		return 1;
	}
	rc = getsockopt (s, SOL_SOCKET, SO_SNDBUF, &optval, &optlen);
	if (rc) {
		perror ("getsockopt");
		return 1;
	}
	if (optlen == sizeof optval) {
		printf ("SNDBUF: %u\n", optval);
	} else {
		printf ("optlen = %ul\n", optlen);
	}
	return 0;
}

fail on Hurd like

wferi@exodar:~$ ./sndbuf 
getsockopt: Protocol not available

?
-- 
Thanks,
Feri