[9front] no more auth in exportfs(4)?

[<me@josuah.net>]

I am trying to PXE boot to my raspberry pi 2, currently acting as
fs, auth and cpu. I boot a laptop over PXE and it works all good,
but the laptop does not have write access to its filesystem.

By running "allow" on /srv/hjfs.cmd, I can write, and the files
are created as user none, the same user as exportfs.

Starting with commit 27a83106f4b5b68d77afa8f800d92398163a7043 there
is no more authentication on exportfs:

-	if(na == nil && doauth){
-		/*
-		 * We use p9any so we don't have to visit this code again, with the
-		 * cost that this code is incompatible with the old world, which
-		 * requires p9sk2. (The two differ in who talks first, so compatibility
-		 * is awkward.)
-		 */
-		ai = auth_proxy(0, auth_getkey, "proto=p9any role=server %s", keyspec);
-		if(ai == nil)
-			fatal("auth_proxy: %r");
-		if(nonone && strcmp(ai->cuid, "none") == 0)
-			fatal("exportfs by none disallowed");
-		if(auth_chuid(ai, nsfile) < 0)
-			fatal("auth_chuid: %r");
-		else {	/* chown network connection */
-			Dir nd;
-			nulldir(&nd);
-			nd.mode = 0660;
-			nd.uid = ai->cuid;
-			dirfwstat(0, &nd);
-		}
-		putenv("service", "exportfs");
-	}

auth_chuid() is what I think am after: writing to capuse.
The long-ish comment seens ti refer to the changes described in
/sys/doc/auth.ps that put factotum as main auth agent.

Is that feature of plan9 moving somewhere else? Am I having the
wrong approach? If it is a work in progress?

I will try a patch adding auth code into exportfs in the meantime,
that will be a good exercise anyway.