[PATCH 0/7] another round of NNTP updates

[PATCH 0/7] another round of NNTP updates

[Eric Wong]

We'll still need better tests, but most of this seems to
work alright.  Must. Fix. XOVER. Performance. Next!

Eric Wong (7):
      nntp: fix XOVER command
      nntpd: additional daemonization options
      nntpd: hard quit after 30s
      nntpd: move busy check to NNTP package
      nntp: avoid infinite loop on partial read
      nntpd: better encapsulation for shutdown
      nntpd: support SIGUSR2 in single-process mode, too

 lib/PublicInbox/NNTP.pm |  21 +++++----
 public-inbox-nntpd      | 118 +++++++++++++++++++++++++++++++++++++++++++-----
 t/nntpd.t               |   9 +++-
 3 files changed, 126 insertions(+), 22 deletions(-)

[PATCH 1/7] nntp: fix XOVER command

[Eric Wong]

Oops, we need to test commands more closely :x
Add a missing prototype while we're at it for extra
checking.
---
 lib/PublicInbox/NNTP.pm | 4 ++--
 t/nntpd.t               | 9 ++++++++-
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/lib/PublicInbox/NNTP.pm b/lib/PublicInbox/NNTP.pm
index 6dc0db3..0d0de97 100644
--- a/lib/PublicInbox/NNTP.pm
+++ b/lib/PublicInbox/NNTP.pm
@@ -762,11 +762,11 @@ sub cmd_xrover ($;$) {
 	});
 }
 
-sub over_line {
+sub over_line ($$) {
 	my ($self, $r) = @_;
 
 	more($self, join("\t", $r->[0], map {
-				my $h = xhdr($r, $_);
+				my $h = hdr_val($r, $_);
 				defined $h ? $h : '';
 			} @OVERVIEW ));
 }
diff --git a/t/nntpd.t b/t/nntpd.t
index 04444e4..ea2c3df 100644
--- a/t/nntpd.t
+++ b/t/nntpd.t
@@ -144,7 +144,14 @@ EOF
 		}
 	}
 
-	# TODO: upgrades and such
+	is_deeply($n->xover('1-'), {
+		'1' => ['hihi',
+			'Me <me@example.com>',
+			'Thu, 01 Jan 1970 06:06:06 +0000',
+			'<nntp@example.com>',
+			'',
+			'202',
+			'1' ] }, "XOVER works");
 
 	ok(kill('TERM', $pid), 'killed nntpd');
 	$pid = undef;
-- 
EW

[PATCH 2/7] nntpd: additional daemonization options

[Eric Wong]

From: Eric Wong <normalperson@yhbt.net>

This should fully support the signals used by nginx and starman,
so scripts used by nginx can be used to manage our nntpd daemon,
too.
---
 public-inbox-nntpd | 98 +++++++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 93 insertions(+), 5 deletions(-)

diff --git a/public-inbox-nntpd b/public-inbox-nntpd
index 674ecad..defb16b 100644
--- a/public-inbox-nntpd
+++ b/public-inbox-nntpd
@@ -8,26 +8,39 @@ require Danga::Socket;
 require IO::Handle;
 use Getopt::Long qw/:config gnu_getopt no_ignore_case auto_abbrev/;
 require PublicInbox::NewsGroup;
+my $set_user;
 my $nntpd = PublicInbox::NNTPD->new;
 my $refresh = sub { $nntpd->refresh_groups };
 $SIG{HUP} = $SIG{USR1} = $SIG{USR2} = $SIG{PIPE} =
 	$SIG{TTIN} = $SIG{TTOU} = $SIG{WINCH} = 'IGNORE';
 
 $refresh->();
-my (@cfg_listen, $stdout, $stderr);
+my (@cfg_listen, $stdout, $stderr, $group, $user, $pid_file, $daemonize);
 my $worker_processes = 0;
 my %opts = (
 	'l|listen=s' => \@cfg_listen,
 	'1|stdout=s' => \$stdout,
 	'2|stderr=s' => \$stderr,
 	'W|worker-processes=i' => \$worker_processes,
+	'P|pid-file=s' => \$pid_file,
+	'u|user=s' => \$user,
+	'g|group=s' => \$group,
+	'D|daemonize' => \$daemonize,
 );
 GetOptions(%opts) or die "bad command-line args\n";
+
+if (defined $pid_file && $pid_file =~ /\.oldbin\z/) {
+	die "--pid-file cannot end with '.oldbin'\n";
+}
+
 my %pids;
 my %listener_names;
 my $reexec_pid;
 my @listeners = inherit();
 
+# ignore daemonize when inheriting
+$daemonize = undef if scalar @listeners;
+
 # default NNTP listener if no listeners
 push @cfg_listen, '0.0.0.0:119' unless (@listeners || @cfg_listen);
 
@@ -47,10 +60,50 @@ foreach my $l (@cfg_listen) {
 	}
 }
 die 'No listeners bound' unless @listeners;
-open(STDIN, '+<', '/dev/null');
+
+chdir '/' or die "chdir failed: $!\n";
+open(STDIN, '+<', '/dev/null') or die "redirect stdin failed: $!\n";
+
+if (defined $pid_file || defined $group || defined $user || $daemonize) {
+	require Net::Server::Daemonize;
+
+	Net::Server::Daemonize::check_pid_file($pid_file) if defined $pid_file;
+	my $uid = Net::Server::Daemonize::get_uid($user) if defined $user;
+	my $gid;
+	if (defined $group) {
+		$gid = Net::Server::Daemonize::get_gid($group);
+		$gid = (split /\s+/, $gid)[0];
+	} elsif (defined $uid) {
+		$gid = (getpwuid($uid))[3];
+	}
+
+	# We change users in the worker to ensure upgradability,
+	# The upgrade will create the ".oldbin" pid file in the
+	# same directory as the given pid file.
+	$uid and $set_user = sub {
+		Net::Server::Daemonize::set_user($uid, $gid);
+	};
+
+	if ($daemonize) {
+		my ($pid, $err) = do_fork();
+		die "could not fork: $err\n" unless defined $pid;
+		exit if $pid;
+
+		open STDOUT, '>&STDIN' or die "redirect stdout failed: $!\n";
+		open STDERR, '>&STDIN' or die "redirect stderr failed: $!\n";
+		POSIX::setsid();
+		($pid, $err) = do_fork();
+		die "could not fork: $err\n" unless defined $pid;
+		exit if $pid;
+	}
+	if (defined $pid_file) {
+		my $unlink_pid = $$;
+		Net::Server::Daemonize::create_pid_file($pid_file);
+		END { unlink_pid_file_safe_ish($unlink_pid, $pid_file) };
+	}
+}
 
 if ($worker_processes > 0) {
-	# my ($p0, $p1, $r, $w);
 	pipe(my ($p0, $p1)) or die "failed to create parent-pipe: $!\n";
 	my %pwatch = ( fileno($p0) => sub { kill('TERM', $$) } );
 	pipe(my ($r, $w)) or die "failed to create self-pipe: $!\n";
@@ -110,6 +163,7 @@ if ($worker_processes > 0) {
 			if (!defined $pid) {
 				warn "failed to fork worker[$i]: $err\n";
 			} elsif ($pid == 0) {
+				$set_user->() if $set_user;
 				close($_) for ($w, $r, $p1);
 				Danga::Socket->AddOtherFds(%pwatch);
 				goto worker;
@@ -209,6 +263,15 @@ sub upgrade {
 		warn "upgrade in-progress: $reexec_pid\n";
 		return;
 	}
+	if (defined $pid_file) {
+		if ($pid_file =~ /\.oldbin\z/) {
+			warn "BUG: .oldbin suffix exists: $pid_file\n";
+			return;
+		}
+		unlink_pid_file_safe_ish($$, $pid_file);
+		$pid_file .= '.oldbin';
+		Net::Server::Daemonize::create_pid_file($pid_file);
+	}
 	my ($pid, $err) = do_fork();
 	unless (defined $pid) {
 		warn "fork failed: $err\n";
@@ -250,12 +313,25 @@ sub do_fork {
 	($pid, $err);
 }
 
+sub upgrade_aborted ($) {
+	my ($p) = @_;
+	warn "reexec PID($p) died with: $?\n";
+	$reexec_pid = undef;
+	return unless $pid_file;
+
+	my $file = $pid_file;
+	$file =~ s/\.oldbin\z// or die "BUG: no '.oldbin' suffix in $file\n";
+	unlink_pid_file_safe_ish($$, $pid_file);
+	$pid_file = $file;
+	eval { Net::Server::Daemonize::create_pid_file($pid_file) };
+	warn $@, "\n" if $@;
+}
+
 sub reap_children {
 	while (1) {
 		my $p = waitpid(-1, &POSIX::WNOHANG) or return;
 		if (defined $reexec_pid && $p == $reexec_pid) {
-			$reexec_pid = undef;
-			warn "reexec PID($p) died with: $?\n";
+			upgrade_aborted($p);
 		} elsif (defined(my $id = delete $pids{$p})) {
 			warn "worker[$id] PID($p) died with: $?\n";
 		} elsif ($p > 0) {
@@ -266,6 +342,18 @@ sub reap_children {
 	}
 }
 
+sub unlink_pid_file_safe_ish ($$) {
+	my ($unlink_pid, $file) = @_;
+	return unless defined $unlink_pid && $unlink_pid == $$;
+
+	open my $fh, '<', $file or return;
+	defined(my $read_pid = <$fh>) or return;
+	chomp $read_pid;
+	if ($read_pid == $unlink_pid) {
+		Net::Server::Daemonize::unlink_pid_file($file);
+	}
+}
+
 1;
 package PublicInbox::Listener;
 use strict;
-- 
EW

[PATCH 3/7] nntpd: hard quit after 30s

[Eric Wong]

We don't want clients hogging server resources and preventing
us from shutting down, so give them 30s to finish whatever
request they're getting.
---
 public-inbox-nntpd | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/public-inbox-nntpd b/public-inbox-nntpd
index defb16b..4c15608 100644
--- a/public-inbox-nntpd
+++ b/public-inbox-nntpd
@@ -195,10 +195,14 @@ sub worker_quit {
 	$_->close for @listeners;
 	@listeners = ();
 
+	# give slow clients 30s to finish reading/writing whatever
+	Danga::Socket->AddTimer(30, sub { exit });
+
 	# drop idle connections and try to quit gracefully
 	Danga::Socket->SetPostLoopCallback(sub {
 		my ($dmap, undef) = @_;
 		my $n = 0;
+
 		foreach my $s (values %$dmap) {
 			next unless ref($s) eq 'PublicInbox::NNTP';
 			if ($s->{write_buf_size} || $s->{rbuf}) {
-- 
EW

[PATCH 4/7] nntpd: move busy check to NNTP package

[Eric Wong]

This is better encapsulated and hopefully more readable.
While we're at it, check for being inside a long response, too.
---
 lib/PublicInbox/NNTP.pm | 5 +++++
 public-inbox-nntpd      | 2 +-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/lib/PublicInbox/NNTP.pm b/lib/PublicInbox/NNTP.pm
index 0d0de97..52d6a64 100644
--- a/lib/PublicInbox/NNTP.pm
+++ b/lib/PublicInbox/NNTP.pm
@@ -919,4 +919,9 @@ sub watch_read {
 	$rv;
 }
 
+sub busy () {
+	my ($self) = @_;
+	($self->{rbuf} ne '' || $self->{long_res} || $self->{write_buf_size});
+}
+
 1;
diff --git a/public-inbox-nntpd b/public-inbox-nntpd
index 4c15608..70bab46 100644
--- a/public-inbox-nntpd
+++ b/public-inbox-nntpd
@@ -205,7 +205,7 @@ sub worker_quit {
 
 		foreach my $s (values %$dmap) {
 			next unless ref($s) eq 'PublicInbox::NNTP';
-			if ($s->{write_buf_size} || $s->{rbuf}) {
+			if ($s->busy) {
 				++$n;
 			} else {
 				$s->close;
-- 
EW

[PATCH 5/7] nntp: avoid infinite loop on partial read

[Eric Wong]

Oops :x
---
 lib/PublicInbox/NNTP.pm | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/lib/PublicInbox/NNTP.pm b/lib/PublicInbox/NNTP.pm
index 52d6a64..6c661a1 100644
--- a/lib/PublicInbox/NNTP.pm
+++ b/lib/PublicInbox/NNTP.pm
@@ -879,22 +879,18 @@ sub event_write {
 sub event_read {
 	my ($self) = @_;
 	use constant LINE_MAX => 512; # RFC 977 section 2.3
-	my $line;
 	my $r = 1;
-again:
+
+	my $buf = $self->read(LINE_MAX) or return $self->close;
+	$self->{rbuf} .= $$buf;
 	while ($r > 0 && $self->{rbuf} =~ s/\A\s*([^\r\n]+)\r?\n//) {
-		$line = $1;
+		my $line = $1;
 		my $t0 = now();
 		$r = eval { $self->process_line($line) };
 		my $d = $self->{long_res} ?
 			' deferred['.fileno($self->{sock}).']' : '';
 		out($self, "$line - %0.6f$d", now() - $t0);
 	}
-	unless (defined $line) {
-		my $buf = $self->read(LINE_MAX) or return $self->close;
-		$self->{rbuf} .= $$buf;
-		goto again;
-	}
 
 	return $self->close if $r < 0;
 	my $len = length($self->{rbuf});
-- 
EW

[PATCH 6/7] nntpd: better encapsulation for shutdown

[Eric Wong]

We can use the UNIVERSAL::can to better encapsulate the shutdown
process, in case we need to implement a gopher or HTTP daemon.
---
 public-inbox-nntpd | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/public-inbox-nntpd b/public-inbox-nntpd
index 70bab46..9fb69ce 100644
--- a/public-inbox-nntpd
+++ b/public-inbox-nntpd
@@ -204,8 +204,7 @@ sub worker_quit {
 		my $n = 0;
 
 		foreach my $s (values %$dmap) {
-			next unless ref($s) eq 'PublicInbox::NNTP';
-			if ($s->busy) {
+			if ($s->can('busy') && $s->busy) {
 				++$n;
 			} else {
 				$s->close;
-- 
EW

[PATCH 7/7] nntpd: support SIGUSR2 in single-process mode, too

[Eric Wong]

We may support SIGUSR2 in single-process mode as long
as permissions aren't wonky.
---
 public-inbox-nntpd | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/public-inbox-nntpd b/public-inbox-nntpd
index 9fb69ce..67fc90b 100644
--- a/public-inbox-nntpd
+++ b/public-inbox-nntpd
@@ -99,6 +99,9 @@ if (defined $pid_file || defined $group || defined $user || $daemonize) {
 	if (defined $pid_file) {
 		my $unlink_pid = $$;
 		Net::Server::Daemonize::create_pid_file($pid_file);
+		if ($uid and !chown($uid, $gid, $pid_file)) {
+			warn "could not chown $pid_file: $!\n";
+		}
 		END { unlink_pid_file_safe_ish($unlink_pid, $pid_file) };
 	}
 }
@@ -175,14 +178,15 @@ if ($worker_processes > 0) {
 		sysread($r, my $buf, 8);
 	}
 } else {
+	$set_user->() if $set_user;
+	$SIG{USR2} = sub { worker_quit() if upgrade() };
 worker:
 	# this calls epoll_create:
-	@listeners = map { PublicInbox::Listener->new($_) } @listeners;
 	reopen_logs();
 	$SIG{QUIT} = $SIG{INT} = $SIG{TERM} = *worker_quit;
 	$SIG{USR1} = *reopen_logs;
 	$SIG{HUP} = $refresh;
-	$_->watch_read(1) for @listeners;
+	PublicInbox::Listener->new($_) for @listeners;
 	Danga::Socket->EventLoop;
 }
 
@@ -192,7 +196,6 @@ sub worker_quit {
 	# killing again terminates immediately:
 	exit unless @listeners;
 
-	$_->close for @listeners;
 	@listeners = ();
 
 	# give slow clients 30s to finish reading/writing whatever
@@ -372,7 +375,9 @@ sub new ($$) {
 	listen($s, 1024);
 	IO::Handle::blocking($s, 0);
 	my $self = fields::new($class);
-	$self->SUPER::new($s);
+	$self->SUPER::new($s); # calls epoll_create for the first socket
+	$self->watch_read(1);
+	$self
 }
 
 sub event_read {
-- 
EW