--- /dev/null
+# Copyright (C) 2020 all contributors <meta@public-inbox.org>
+# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
+
+# Backend for `lei' (local email interface). Unlike the C10K-oriented
+# PublicInbox::Daemon, this is designed exclusively to handle trusted
+# local clients with read/write access to the FS and use as many
+# system resources as the local user has access to.
+package PublicInbox::LeiDaemon;
+use strict;
+use v5.10.1;
+use parent qw(PublicInbox::DS);
+use Getopt::Long ();
+use Errno qw(EAGAIN ECONNREFUSED ENOENT);
+use POSIX qw(setsid);
+use IO::Socket::UNIX;
+use IO::Handle ();
+use Sys::Syslog qw(syslog openlog);
+use PublicInbox::Syscall qw($SFD_NONBLOCK EPOLLIN EPOLLONESHOT);
+use PublicInbox::Sigfd;
+use PublicInbox::DS qw(now);
+use PublicInbox::Spawn qw(spawn);
+our $quit = sub { exit(shift // 0) };
+my $glp = Getopt::Long::Parser->new;
+$glp->configure(qw(gnu_getopt no_ignore_case auto_abbrev));
+
+sub x_it ($$) { # pronounced "exit"
+ my ($client, $code) = @_;
+ if (my $sig = ($code & 127)) {
+ kill($sig, $client->{pid} // $$);
+ } else {
+ $code >>= 8;
+ if (my $sock = $client->{sock}) {
+ say $sock "exit=$code";
+ } else { # for oneshot
+ $quit->($code);
+ }
+ }
+}
+
+sub emit ($$$) {
+ my ($client, $channel, $buf) = @_;
+ print { $client->{$channel} } $buf or warn "print FD[$channel]: $!";
+}
+
+sub fail ($$;$) {
+ my ($client, $buf, $exit_code) = @_;
+ $buf .= "\n" unless $buf =~ /\n\z/s;
+ emit($client, 2, $buf);
+ x_it($client, ($exit_code // 1) << 8);
+ undef;
+}
+
+sub _help ($;$) {
+ my ($client, $channel) = @_;
+ emit($client, $channel //= 1, <<EOF);
+usage: lei COMMAND [OPTIONS]
+
+...
+EOF
+ x_it($client, $channel == 2 ? 1 << 8 : 0); # stderr => failure
+}
+
+sub assert_args ($$$;$@) {
+ my ($client, $argv, $proto, $opt, @spec) = @_;
+ $opt //= {};
+ push @spec, qw(help|h);
+ $glp->getoptionsfromarray($argv, $opt, @spec) or
+ return fail($client, 'bad arguments or options');
+ if ($opt->{help}) {
+ _help($client);
+ undef;
+ } else {
+ my ($nreq, $rest) = split(/;/, $proto);
+ $nreq = (($nreq // '') =~ tr/$/$/);
+ my $argc = scalar(@$argv);
+ my $tot = ($rest // '') eq '@' ? $argc : ($proto =~ tr/$/$/);
+ return 1 if $argc <= $tot && $argc >= $nreq;
+ _help($client, 2);
+ undef
+ }
+}
+
+sub dispatch {
+ my ($client, $cmd, @argv) = @_;
+ local $SIG{__WARN__} = sub { emit($client, 2, "@_") };
+ local $SIG{__DIE__} = 'DEFAULT';
+ if (defined $cmd) {
+ my $func = "lei_$cmd";
+ $func =~ tr/-/_/;
+ if (my $cb = __PACKAGE__->can($func)) {
+ $client->{cmd} = $cmd;
+ $cb->($client, \@argv);
+ } elsif (grep(/\A-/, $cmd, @argv)) {
+ assert_args($client, [ $cmd, @argv ], '');
+ } else {
+ fail($client, "`$cmd' is not an lei command");
+ }
+ } else {
+ _help($client, 2);
+ }
+}
+
+sub lei_daemon_pid {
+ my ($client, $argv) = @_;
+ assert_args($client, $argv, '') and emit($client, 1, "$$\n");
+}
+
+sub lei_DBG_pwd {
+ my ($client, $argv) = @_;
+ assert_args($client, $argv, '') and
+ emit($client, 1, "$client->{env}->{PWD}\n");
+}
+
+sub lei_DBG_cwd {
+ my ($client, $argv) = @_;
+ require Cwd;
+ assert_args($client, $argv, '') and emit($client, 1, Cwd::cwd()."\n");
+}
+
+sub lei_DBG_false { x_it($_[0], 1 << 8) }
+
+sub lei_daemon_stop {
+ my ($client, $argv) = @_;
+ assert_args($client, $argv, '') and $quit->(0);
+}
+
+sub lei_help { _help($_[0]) }
+
+sub reap_exec { # dwaitpid callback
+ my ($client, $pid) = @_;
+ x_it($client, $?);
+}
+
+sub lei_git { # support passing through random git commands
+ my ($client, $argv) = @_;
+ my %opt = map { $_ => $client->{$_} } (0..2);
+ my $pid = spawn(['git', @$argv], $client->{env}, \%opt);
+ PublicInbox::DS::dwaitpid($pid, \&reap_exec, $client);
+}
+
+sub accept_dispatch { # Listener {post_accept} callback
+ my ($sock) = @_; # ignore other
+ $sock->blocking(1);
+ $sock->autoflush(1);
+ my $client = { sock => $sock };
+ vec(my $rin = '', fileno($sock), 1) = 1;
+ # `say $sock' triggers "die" in lei(1)
+ for my $i (0..2) {
+ if (select(my $rout = $rin, undef, undef, 1)) {
+ my $fd = IO::FDPass::recv(fileno($sock));
+ if ($fd >= 0) {
+ my $rdr = ($fd == 0 ? '<&=' : '>&=');
+ if (open(my $fh, $rdr, $fd)) {
+ $client->{$i} = $fh;
+ } else {
+ say $sock "open($rdr$fd) (FD=$i): $!";
+ return;
+ }
+ } else {
+ say $sock "recv FD=$i: $!";
+ return;
+ }
+ } else {
+ say $sock "timed out waiting to recv FD=$i";
+ return;
+ }
+ }
+ # $ARGV_STR = join("]\0[", @ARGV);
+ # $ENV_STR = join('', map { "$_=$ENV{$_}\0" } keys %ENV);
+ # $line = "$$\0\0>$ARGV_STR\0\0>$ENV_STR\0\0";
+ my ($client_pid, $argv, $env) = do {
+ local $/ = "\0\0\0"; # yes, 3 NULs at EOL, not 2
+ chomp(my $line = <$sock>);
+ split(/\0\0>/, $line, 3);
+ };
+ my %env = map { split(/=/, $_, 2) } split(/\0/, $env);
+ if (chdir($env{PWD})) {
+ $client->{env} = \%env;
+ $client->{pid} = $client_pid;
+ eval { dispatch($client, split(/\]\0\[/, $argv)) };
+ say $sock $@ if $@;
+ } else {
+ say $sock "chdir($env{PWD}): $!"; # implicit close
+ }
+}
+
+sub noop {}
+
+# lei(1) calls this when it can't connect
+sub lazy_start ($$) {
+ my ($path, $err) = @_;
+ if ($err == ECONNREFUSED) {
+ unlink($path) or die "unlink($path): $!";
+ } elsif ($err != ENOENT) {
+ die "connect($path): $!";
+ }
+ my $umask = umask(077) // die("umask(077): $!");
+ my $l = IO::Socket::UNIX->new(Local => $path,
+ Listen => 1024,
+ Type => SOCK_STREAM) or
+ $err = $!;
+ umask($umask) or die("umask(restore): $!");
+ $l or return $err;
+ my @st = stat($path) or die "stat($path): $!";
+ my $dev_ino_expect = pack('dd', $st[0], $st[1]); # dev+ino
+ pipe(my ($eof_r, $eof_w)) or die "pipe: $!";
+ my $oldset = PublicInbox::Sigfd::block_signals();
+ my $pid = fork // die "fork: $!";
+ if ($pid) {
+ PublicInbox::Sigfd::sig_setmask($oldset);
+ return; # client will connect to $path
+ }
+ openlog($path, 'pid', 'user');
+ local $SIG{__DIE__} = sub {
+ syslog('crit', "@_");
+ exit $! if $!;
+ exit $? >> 8 if $? >> 8;
+ exit 255;
+ };
+ local $SIG{__WARN__} = sub { syslog('warning', "@_") };
+ open(STDIN, '+<', '/dev/null') or die "redirect stdin failed: $!\n";
+ open STDOUT, '>&STDIN' or die "redirect stdout failed: $!\n";
+ open STDERR, '>&STDIN' or die "redirect stderr failed: $!\n";
+ setsid();
+ $pid = fork // die "fork: $!";
+ exit if $pid;
+ $0 = "lei-daemon $path";
+ require PublicInbox::Listener;
+ require PublicInbox::EOFpipe;
+ $l->blocking(0);
+ $eof_w->blocking(0);
+ $eof_r->blocking(0);
+ my $listener = PublicInbox::Listener->new($l, \&accept_dispatch, $l);
+ my $exit_code;
+ local $quit = sub {
+ $exit_code //= shift;
+ my $tmp = $listener or exit($exit_code);
+ unlink($path) if defined($path);
+ syswrite($eof_w, '.');
+ $l = $listener = $path = undef;
+ $tmp->close if $tmp; # DS::close
+ PublicInbox::DS->SetLoopTimeout(1000);
+ };
+ PublicInbox::EOFpipe->new($eof_r, sub {}, undef);
+ my $sig = {
+ CHLD => \&PublicInbox::DS::enqueue_reap,
+ QUIT => $quit,
+ INT => $quit,
+ TERM => $quit,
+ HUP => \&noop,
+ USR1 => \&noop,
+ USR2 => \&noop,
+ };
+ my $sigfd = PublicInbox::Sigfd->new($sig, $SFD_NONBLOCK);
+ local %SIG = (%SIG, %$sig) if !$sigfd;
+ if ($sigfd) { # TODO: use inotify/kqueue to detect unlinked sockets
+ PublicInbox::DS->SetLoopTimeout(5000);
+ } else {
+ # wake up every second to accept signals if we don't
+ # have signalfd or IO::KQueue:
+ PublicInbox::Sigfd::sig_setmask($oldset);
+ PublicInbox::DS->SetLoopTimeout(1000);
+ }
+ PublicInbox::DS->SetPostLoopCallback(sub {
+ my ($dmap, undef) = @_;
+ if (@st = defined($path) ? stat($path) : ()) {
+ if ($dev_ino_expect ne pack('dd', $st[0], $st[1])) {
+ warn "$path dev/ino changed, quitting\n";
+ $path = undef;
+ }
+ } elsif (defined($path)) {
+ warn "stat($path): $!, quitting ...\n";
+ undef $path; # don't unlink
+ $quit->();
+ }
+ return 1 if defined($path);
+ my $now = now();
+ my $n = 0;
+ for my $s (values %$dmap) {
+ $s->can('busy') or next;
+ if ($s->busy($now)) {
+ ++$n;
+ } else {
+ $s->close;
+ }
+ }
+ $n; # true: continue, false: stop
+ });
+ PublicInbox::DS->EventLoop;
+ exit($exit_code // 0);
+}
+
+# for users w/o IO::FDPass
+sub oneshot {
+ dispatch({
+ 0 => *STDIN{IO},
+ 1 => *STDOUT{IO},
+ 2 => *STDERR{IO},
+ env => \%ENV
+ }, @ARGV);
+}
+
+1;
--- /dev/null
+#!perl -w
+# Copyright (C) 2020 all contributors <meta@public-inbox.org>
+# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
+use strict;
+use v5.10.1;
+use Test::More;
+use PublicInbox::TestCommon;
+use PublicInbox::Config;
+my $json = PublicInbox::Config::json() or plan skip_all => 'JSON missing';
+require_mods(qw(DBD::SQLite Search::Xapian));
+my ($home, $for_destroy) = tmpdir();
+my $opt = { 1 => \(my $out = ''), 2 => \(my $err = '') };
+
+SKIP: {
+ require_mods('IO::FDPass', 51);
+ local $ENV{XDG_RUNTIME_DIR} = "$home/xdg_run";
+ mkdir "$home/xdg_run", 0700 or BAIL_OUT "mkdir: $!";
+ my $sock = "$ENV{XDG_RUNTIME_DIR}/lei/sock";
+
+ ok(run_script([qw(lei daemon-pid)], undef, $opt), 'daemon-pid');
+ is($err, '', 'no error from daemon-pid');
+ like($out, qr/\A[0-9]+\n\z/s, 'pid returned') or BAIL_OUT;
+ chomp(my $pid = $out);
+ ok(kill(0, $pid), 'pid is valid');
+ ok(-S $sock, 'sock created');
+
+ ok(!run_script([qw(lei)], undef, $opt), 'no args fails');
+ is($? >> 8, 1, '$? is 1');
+ is($out, '', 'nothing in stdout');
+ like($err, qr/^usage:/sm, 'usage in stderr');
+
+ for my $arg (['-h'], ['--help'], ['help'], [qw(daemon-pid --help)]) {
+ $out = $err = '';
+ ok(run_script(['lei', @$arg], undef, $opt), "lei @$arg");
+ like($out, qr/^usage:/sm, "usage in stdout (@$arg)");
+ is($err, '', "nothing in stderr (@$arg)");
+ }
+
+ ok(!run_script([qw(lei DBG-false)], undef, $opt), 'false(1) emulation');
+ is($? >> 8, 1, '$? set correctly');
+ is($err, '', 'no error from false(1) emulation');
+
+ for my $arg ([''], ['--halp'], ['halp'], [qw(daemon-pid --halp)]) {
+ $out = $err = '';
+ ok(!run_script(['lei', @$arg], undef, $opt), "lei @$arg");
+ is($? >> 8, 1, '$? set correctly');
+ isnt($err, '', 'something in stderr');
+ is($out, '', 'nothing in stdout');
+ }
+
+ $out = '';
+ ok(run_script([qw(lei daemon-pid)], undef, $opt), 'daemon-pid');
+ chomp(my $pid_again = $out);
+ is($pid, $pid_again, 'daemon-pid idempotent');
+
+ ok(run_script([qw(lei daemon-stop)], undef, $opt), 'daemon-stop');
+ is($out, '', 'no output from daemon-stop');
+ is($err, '', 'no error from daemon-stop');
+ for (0..100) {
+ kill(0, $pid) or last;
+ tick();
+ }
+ ok(!-S $sock, 'sock gone');
+ ok(!kill(0, $pid), 'pid gone after stop');
+
+ ok(run_script([qw(lei daemon-pid)], undef, $opt), 'daemon-pid');
+ chomp(my $new_pid = $out);
+ ok(kill(0, $new_pid), 'new pid is running');
+ ok(-S $sock, 'sock exists again');
+ unlink $sock or BAIL_OUT "unlink $!";
+ for (0..100) {
+ kill('CHLD', $new_pid) or last;
+ tick();
+ }
+ ok(!kill(0, $new_pid), 'daemon exits after unlink');
+};
+
+require_ok 'PublicInbox::LeiDaemon';
+
+done_testing;