#include <u.h>#include <libc.h>#include <authsrv.h>#include <bio.h>#include <ndb.h> intauthdial(char *netroot, char *dom){	Ndbtuple *t, *nt;	char *p;	int rv; 	if(dom == nil)		/* look for one relative to my machine */		return dial(netmkaddr("$auth", nil, "ticket"), nil, nil, nil); 	/* look up an auth server in an authentication domain */	p = csgetvalue(netroot, "authdom", dom, "auth", &t); 	/* if that didn't work, just try the IP domain */	if(p == nil)		p = csgetvalue(netroot, "dom", dom, "auth", &t); 	/*	 * if that didn't work, try p9auth.$dom.  this is very helpful if	 * you can't edit /lib/ndb.	 */	if(p == nil) {		p = smprint("p9auth.%s", dom);		t = ndbnew("auth", p);	}	free(p); 	/*	 * allow multiple auth= attributes for backup auth servers,	 * try each one in order.	 */	rv = -1;	for(nt = t; nt != nil; nt = nt->entry) {		if(strcmp(nt->attr, "auth") == 0) {			rv = dial(netmkaddr(nt->val, nil, "ticket"), nil, nil, nil);			if(rv >= 0)				break;		}	}	ndbfree(t); 	return rv;}