implement Connect; include "sys.m";	sys: Sys; include "draw.m";include "keyring.m";include "security.m";include "arg.m"; Connect: module{	init: fn(ctxt: ref Draw->Context, argv: list of string);}; remotedir := "/n/remote";localdir := "/n/ftree/collab";COLLABPORT: con "9999";	# TO DO: needs symbolic name in services usage(){	sys->fprint(sys->fildes(2), "Usage: connect [-v] [-C cryptoalg] [-k keyring] [net!addr [localdir]]\n");	raise "fail:usage";} init(nil: ref Draw->Context, args: list of string){	sys = load Sys Sys->PATH; 	vflag := 0;	alg := "none";	keyfile := "";	netaddr := "$collab"; 	arg := load Arg Arg->PATH;	if(arg != nil){		arg->init(args);		while((c := arg->opt()) != 0)			case c {			'C' =>				alg = arg->arg();			'k' =>				keyfile = arg->arg();			'v' =>				vflag++;			* =>				usage();			}	}	args = arg->argv();	arg = nil; 	if(args != nil){		netaddr = hd args;		args = tl args;		if(args != nil)			localdir = hd args;	} 	if(vflag)		sys->print("connect: dial %s\n", netaddr);	(fd, user) := authdial(netaddr, keyfile, alg);	if(vflag)		sys->print("remote username is %s\n", user);	if(sys->mount(fd, nil, remotedir, Sys->MREPL, nil) < 0)		error(sys->sprint("can't mount %s on %s: %r", netaddr, remotedir));	fd = nil; 	connectdir := remotedir+"/collab";	if (sys->bind(connectdir, localdir, Sys->MCREATE|Sys->MREPL) < 0){		error(sys->sprint("cannot bind %s onto %s: %r\n", connectdir, localdir));		raise "fail:error";	} 	# if something such as ftree is running and watching for changes, tell it about this one	fd = sys->open("/chan/nsupdate", Sys->OWRITE);	if(fd != nil)		sys->fprint(fd, "/n/ftree/collab");	if(vflag)		sys->print("collab connected\n");} authdial(addr, keyfile, alg: string): (ref Sys->FD, string){	cert : string; 	kr := load Keyring Keyring->PATH;	if(kr == nil)		error(sys->sprint("cannot load %s: %r", Keyring->PATH)); 	kd := "/usr/" + user() + "/keyring/";	if (keyfile == nil) {		cert = kd + netmkaddr(addr, "tcp", "");		(ok, nil) := sys->stat(cert);		if (ok < 0)			cert = kd + "default";	}	else if (len keyfile > 0 && keyfile[0] != '/')		cert = kd + keyfile;	else		cert = keyfile;	ai := kr->readauthinfo(cert);	if (ai == nil)		error(sys->sprint("cannot read authentication data from %s: %r", cert)); 	au := load Auth Auth->PATH;	if(au == nil)		error(sys->sprint("cannot load %s: %r", Auth->PATH));	err := au->init();	if(err != nil)		error(sys->sprint("cannot init Auth: %s", err)); 	(ok, c) := sys->dial(netmkaddr(addr, "tcp", COLLABPORT), nil);	if(ok < 0)		error(sys->sprint("can't dial %s: %r", addr));	(fd, id_or_err) := au->client(alg, ai, c.dfd);	if(fd == nil)		error(sys->sprint("authentication failed: %s", id_or_err)); 	return (fd, id_or_err);} user(): string{	fd := sys->open("/dev/user", sys->OREAD);	if(fd == nil)		return ""; 	buf := array[Sys->NAMEMAX] of byte;	n := sys->read(fd, buf, len buf);	if(n < 0)		return ""; 	return string buf[0:n]; } netmkaddr(addr, net, svc: string): string{	if(net == nil)		net = "net";	(n, l) := sys->tokenize(addr, "!");	if(n <= 1){		if(svc== nil)			return sys->sprint("%s!%s", net, addr);		return sys->sprint("%s!%s!%s", net, addr, svc);	}	if(svc == nil || n > 2)		return addr;	return sys->sprint("%s!%s", addr, svc);} error(m: string){	sys->fprint(sys->fildes(2), "connect: %s\n", m);	raise "fail:error";}