ref: 3efb5bbb4061056e523858b134c555949591efe2
dir: /appl/cmd/styxlisten.b/
implement Styxlisten;
include "sys.m";
sys: Sys;
include "draw.m";
include "keyring.m";
keyring: Keyring;
include "security.m";
auth: Auth;
include "dial.m";
dial: Dial;
include "arg.m";
include "sh.m";
Styxlisten: module {
init: fn(nil: ref Draw->Context, argv: list of string);
};
badmodule(p: string)
{
sys->fprint(stderr(), "styxlisten: cannot load %s: %r\n", p);
raise "fail:bad module";
}
verbose := 0;
passhostnames := 0;
init(ctxt: ref Draw->Context, argv: list of string)
{
sys = load Sys Sys->PATH;
auth = load Auth Auth->PATH;
if (auth == nil)
badmodule(Auth->PATH);
dial = load Dial Dial->PATH;
if (dial == nil)
badmodule(Dial->PATH);
if ((e := auth->init()) != nil)
error("auth init failed: " + e);
keyring = load Keyring Keyring->PATH;
if (keyring == nil)
badmodule(Keyring->PATH);
arg := load Arg Arg->PATH;
if (arg == nil)
badmodule(Arg->PATH);
arg->init(argv);
arg->setusage("styxlisten [-a alg]... [-Atsv] [-k keyfile] address cmd [arg...]");
algs: list of string;
doauth := 1;
synchronous := 0;
trusted := 0;
keyfile := "";
while ((opt := arg->opt()) != 0) {
case opt {
'v' =>
verbose = 1;
'a' =>
algs = arg->earg() :: algs;
'f' or
'k' =>
keyfile = arg->earg();
if (! (keyfile[0] == '/' || (len keyfile > 2 && keyfile[0:2] == "./")))
keyfile = "/usr/" + user() + "/keyring/" + keyfile;
'h' =>
passhostnames = 1;
't' =>
trusted = 1;
's' =>
synchronous = 1;
'A' =>
doauth = 0;
* =>
arg->usage();
}
}
argv = arg->argv();
if (len argv < 2)
arg->usage();
arg = nil;
if (doauth && algs == nil)
algs = getalgs();
addr := dial->netmkaddr(hd argv, "tcp", "styx");
cmd := tl argv;
authinfo: ref Keyring->Authinfo;
if (doauth) {
if (keyfile == nil)
keyfile = "/usr/" + user() + "/keyring/default";
authinfo = keyring->readauthinfo(keyfile);
if (authinfo == nil)
error(sys->sprint("cannot read %s: %r", keyfile));
}
c := dial->announce(addr);
if (c == nil)
error(sys->sprint("cannot announce on %s: %r", addr));
if(!trusted){
sys->unmount(nil, "/mnt/keys"); # should do for now
# become none?
}
lsync := chan[1] of int;
if(synchronous)
listener(c, popen(ctxt, cmd, lsync), authinfo, algs, lsync);
else
spawn listener(c, popen(ctxt, cmd, lsync), authinfo, algs, lsync);
}
listener(c: ref Dial->Connection, mfd: ref Sys->FD, authinfo: ref Keyring->Authinfo, algs: list of string, lsync: chan of int)
{
lsync <-= sys->pctl(0, nil);
for (;;) {
nc := dial->listen(c);
if (nc == nil)
error(sys->sprint("listen failed: %r"));
if (verbose)
sys->fprint(stderr(), "styxlisten: got connection from %s",
readfile(nc.dir + "/remote"));
dfd := dial->accept(nc);
if (dfd != nil) {
if(nc.cfd != nil)
sys->fprint(nc.cfd, "keepalive");
hostname: string;
if(passhostnames){
hostname = readfile(nc.dir + "/remote");
if(hostname != nil)
hostname = hostname[0:len hostname - 1];
}
if (algs == nil) {
sync := chan of int;
spawn exportproc(sync, mfd, nil, hostname, dfd);
<-sync;
} else
spawn authenticator(dfd, authinfo, mfd, algs, hostname);
}
}
}
# authenticate a connection and set the user id.
authenticator(dfd: ref Sys->FD, authinfo: ref Keyring->Authinfo, mfd: ref Sys->FD,
algs: list of string, hostname: string)
{
# authenticate and change user id appropriately
(fd, err) := auth->server(algs, authinfo, dfd, 1);
if (fd == nil) {
if (verbose)
sys->fprint(stderr(), "styxlisten: authentication failed: %s\n", err);
return;
}
if (verbose)
sys->fprint(stderr(), "styxlisten: client authenticated as %s\n", err);
sync := chan of int;
spawn exportproc(sync, mfd, err, hostname, fd);
<-sync;
}
exportproc(sync: chan of int, fd: ref Sys->FD, uname, hostname: string, dfd: ref Sys->FD)
{
sys->pctl(Sys->NEWFD | Sys->NEWNS, 2 :: fd.fd :: dfd.fd :: nil);
fd = sys->fildes(fd.fd);
dfd = sys->fildes(dfd.fd);
sync <-= 1;
# XXX unfortunately we cannot pass through the aname from
# the original attach, an inherent shortcoming of this scheme.
if (sys->mount(fd, nil, "/", Sys->MREPL|Sys->MCREATE, hostname) == -1)
error(sys->sprint("cannot mount for user '%s': %r\n", uname));
sys->export(dfd, "/", Sys->EXPWAIT);
}
error(e: string)
{
sys->fprint(stderr(), "styxlisten: %s\n", e);
raise "fail:error";
}
popen(ctxt: ref Draw->Context, argv: list of string, lsync: chan of int): ref Sys->FD
{
sync := chan of int;
fds := array[2] of ref Sys->FD;
sys->pipe(fds);
spawn runcmd(ctxt, argv, fds[0], sync, lsync);
<-sync;
return fds[1];
}
runcmd(ctxt: ref Draw->Context, argv: list of string, stdin: ref Sys->FD,
sync: chan of int, lsync: chan of int)
{
sys->pctl(Sys->FORKFD, nil);
sys->dup(stdin.fd, 0);
stdin = nil;
sync <-= 0;
sh := load Sh Sh->PATH;
e := sh->run(ctxt, argv);
kill(<-lsync, "kill"); # kill listener, as command has exited
if(verbose){
if(e != nil)
sys->fprint(stderr(), "styxlisten: command exited with error: %s\n", e);
else
sys->fprint(stderr(), "styxlisten: command exited\n");
}
}
kill(pid: int, how: string)
{
sys->fprint(sys->open("/prog/"+string pid+"/ctl", Sys->OWRITE), "%s", how);
}
user(): string
{
if ((s := readfile("/dev/user")) == nil)
return "none";
return s;
}
readfile(f: string): string
{
fd := sys->open(f, sys->OREAD);
if(fd == nil)
return nil;
buf := array[1024] of byte;
n := sys->read(fd, buf, len buf);
if(n < 0)
return nil;
return string buf[0:n];
}
getalgs(): list of string
{
sslctl := readfile("#D/clone");
if (sslctl == nil) {
sslctl = readfile("#D/ssl/clone");
if (sslctl == nil)
return nil;
sslctl = "#D/ssl/" + sslctl;
} else
sslctl = "#D/" + sslctl;
(nil, algs) := sys->tokenize(readfile(sslctl + "/encalgs") + " " + readfile(sslctl + "/hashalgs"), " \t\n");
return "none" :: algs;
}
stderr(): ref Sys->FD
{
return sys->fildes(2);
}