# Copyright (C) 2015-2018 all contributors # License: AGPL-3.0+ # contains common daemon code for the nntpd and httpd servers. # This may be used for read-only IMAP server if we decide to implement it. package PublicInbox::Daemon; use strict; use warnings; use Getopt::Long qw/:config gnu_getopt no_ignore_case auto_abbrev/; use IO::Handle; use IO::Socket; use Cwd qw/abs_path/; STDOUT->autoflush(1); STDERR->autoflush(1); use PublicInbox::DS qw(now); require PublicInbox::EvCleanup; require POSIX; require PublicInbox::Listener; require PublicInbox::ParentPipe; my @CMD; my $set_user; my (@cfg_listen, $stdout, $stderr, $group, $user, $pid_file, $daemonize); my $worker_processes = 1; my @listeners; my %pids; my %listener_names; my $reexec_pid; my $cleanup; my ($uid, $gid); END { $cleanup->() if $cleanup }; sub daemon_prepare ($) { my ($default_listen) = @_; @CMD = ($0, @ARGV); $SIG{HUP} = $SIG{USR1} = $SIG{USR2} = $SIG{PIPE} = $SIG{TTIN} = $SIG{TTOU} = $SIG{WINCH} = 'IGNORE'; 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"; } @listeners = inherit(); # ignore daemonize when inheriting $daemonize = undef if scalar @listeners; push @cfg_listen, $default_listen unless (@listeners || @cfg_listen); foreach my $l (@cfg_listen) { next if $listener_names{$l}; # already inherited my (%o, $sock_pkg); if (index($l, '/') == 0) { $sock_pkg = 'IO::Socket::UNIX'; eval "use $sock_pkg"; die $@ if $@; %o = (Type => SOCK_STREAM, Peer => $l); if (-S $l) { my $c = $sock_pkg->new(%o); if (!defined($c) && $!{ECONNREFUSED}) { unlink $l or die "failed to unlink stale socket=$l: $!\n"; } # else: let the bind fail } $o{Local} = delete $o{Peer}; } else { # both work for IPv4, too for (qw(IO::Socket::IP IO::Socket::INET6)) { $sock_pkg = $_; eval "use $sock_pkg"; $@ or last; } die $@ if $@; %o = (LocalAddr => $l, ReuseAddr => 1, Proto => 'tcp'); } $o{Listen} = 1024; my $prev = umask 0000; my $s = eval { $sock_pkg->new(%o) }; warn "error binding $l: $! ($@)\n" unless $s; umask $prev; if ($s) { $listener_names{sockname($s)} = $s; push @listeners, $s; } } die "No listeners bound\n" unless @listeners; } sub check_absolute ($$) { my ($var, $val) = @_; if (defined $val && index($val, '/') != 0) { die "--$var must be an absolute path when using --daemonize: $val\n"; } } sub daemonize () { if ($daemonize) { foreach my $i (0..$#ARGV) { my $arg = $ARGV[$i]; next unless -e $arg; $ARGV[$i] = abs_path($arg); } check_absolute('stdout', $stdout); check_absolute('stderr', $stderr); check_absolute('pid-file', $pid_file); chdir '/' or die "chdir failed: $!"; } return unless (defined $pid_file || defined $group || defined $user || $daemonize); eval { require Net::Server::Daemonize }; if ($@) { die "Net::Server required for --pid-file, --group, --user, and --daemonize\n$@\n"; } Net::Server::Daemonize::check_pid_file($pid_file) if defined $pid_file; $uid = Net::Server::Daemonize::get_uid($user) if defined $user; if (defined $group) { $gid = Net::Server::Daemonize::get_gid($group); $gid = (split /\s+/, $gid)[0]; } elsif (defined $uid) { $gid = (getpwuid($uid))[3]; } # We change users in the worker to ensure upgradability, # The upgrade will create the ".oldbin" pid file in the # same directory as the given pid file. $uid and $set_user = sub { $set_user = undef; Net::Server::Daemonize::set_user($uid, $gid); }; if ($daemonize) { my $pid = fork; die "could not fork: $!\n" unless defined $pid; exit if $pid; open(STDIN, '+<', '/dev/null') or die "redirect stdin failed: $!\n"; open STDOUT, '>&STDIN' or die "redirect stdout failed: $!\n"; open STDERR, '>&STDIN' or die "redirect stderr failed: $!\n"; POSIX::setsid(); $pid = fork; die "could not fork: $!\n" unless defined $pid; exit if $pid; } if (defined $pid_file) { write_pid($pid_file); my $unlink_pid = $$; $cleanup = sub { $cleanup = undef; # avoid cyclic reference unlink_pid_file_safe_ish($unlink_pid, $pid_file); }; } } sub worker_quit { my ($reason) = @_; # killing again terminates immediately: exit unless @listeners; $_->close foreach @listeners; # call PublicInbox::DS::close @listeners = (); $reason->close if ref($reason) eq 'PublicInbox::ParentPipe'; my $proc_name; my $warn = 0; # drop idle connections and try to quit gracefully PublicInbox::DS->SetPostLoopCallback(sub { my ($dmap, undef) = @_; my $n = 0; my $now = now(); foreach my $s (values %$dmap) { $s->can('busy') or next; if ($s->busy($now)) { ++$n; } else { # close as much as possible, early as possible $s->close; } } if ($n) { if (($warn + 5) < now()) { warn "$$ quitting, $n client(s) left\n"; $warn = now(); } unless (defined $proc_name) { $proc_name = (split(/\s+/, $0))[0]; $proc_name =~ s!\A.*?([^/]+)\z!$1!; } $0 = "$proc_name quitting, $n client(s) left"; } $n; # true: loop continues, false: loop breaks }); } sub reopen_logs { if ($stdout) { open STDOUT, '>>', $stdout or warn "failed to redirect stdout to $stdout: $!\n"; STDOUT->autoflush(1); do_chown($stdout); } if ($stderr) { open STDERR, '>>', $stderr or warn "failed to redirect stderr to $stderr: $!\n"; STDERR->autoflush(1); do_chown($stderr); } } sub sockname ($) { my ($s) = @_; my $addr = getsockname($s) or return; my ($host, $port) = host_with_port($addr); if ($port == 0 && $host eq '127.0.0.1') { my ($path) = Socket::sockaddr_un($addr); return $path; } "$host:$port"; } sub unpack_ipv6 ($) { my ($addr) = @_; my ($port, $host); # Socket.pm in Perl 5.14+ supports IPv6: eval { ($port, $host) = Socket::unpack_sockaddr_in6($addr); $host = Socket::inet_ntop(Socket::AF_INET6(), $host); }; if ($@) { # Perl 5.12 or earlier? SpamAssassin and Net::Server use # Socket6, so it may be installed on our system, already # (otherwise die here): require Socket6; ($port, $host) = Socket6::unpack_sockaddr_in6($addr); $host = Socket6::inet_ntop(Socket6::AF_INET6(), $host); } ($host, $port); } sub host_with_port ($) { my ($addr) = @_; my ($port, $host); # this eval will die on Unix sockets: eval { if (length($addr) >= 28) { ($host, $port) = unpack_ipv6($addr); $host = "[$host]"; } else { ($port, $host) = Socket::sockaddr_in($addr); $host = Socket::inet_ntoa($host); } }; $@ ? ('127.0.0.1', 0) : ($host, $port); } sub inherit () { return () if ($ENV{LISTEN_PID} || 0) != $$; my $fds = $ENV{LISTEN_FDS} or return (); my $end = $fds + 2; # LISTEN_FDS_START - 1 my @rv = (); foreach my $fd (3..$end) { my $s = IO::Handle->new_from_fd($fd, 'r'); if (my $k = sockname($s)) { $listener_names{$k} = $s; push @rv, $s; } else { warn "failed to inherit fd=$fd (LISTEN_FDS=$fds)"; } } @rv } sub upgrade () { if ($reexec_pid) { 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($$, $pid_file); $pid_file .= '.oldbin'; write_pid($pid_file); } my $pid = fork; unless (defined $pid) { warn "fork failed: $!\n"; return; } if ($pid == 0) { use Fcntl qw(FD_CLOEXEC F_SETFD F_GETFD); $ENV{LISTEN_FDS} = scalar @listeners; $ENV{LISTEN_PID} = $$; foreach my $s (@listeners) { my $fl = fcntl($s, F_GETFD, 0); fcntl($s, F_SETFD, $fl &= ~FD_CLOEXEC); } exec @CMD; die "Failed to exec: $!\n"; } $reexec_pid = $pid; } sub kill_workers ($) { my ($s) = @_; while (my ($pid, $id) = each %pids) { kill $s, $pid; } } sub upgrade_aborted ($) { 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"; unlink_pid_file_safe_ish($$, $pid_file); $pid_file = $file; eval { write_pid($pid_file) }; warn $@, "\n" if $@; } sub reap_children () { while (1) { my $p = waitpid(-1, &POSIX::WNOHANG) or return; if (defined $reexec_pid && $p == $reexec_pid) { upgrade_aborted($p); } elsif (defined(my $id = delete $pids{$p})) { warn "worker[$id] PID($p) died with: $?\n"; } elsif ($p > 0) { warn "unknown PID($p) reaped: $?\n"; } else { return; } } } sub unlink_pid_file_safe_ish ($$) { my ($unlink_pid, $file) = @_; return unless defined $unlink_pid && $unlink_pid == $$; open my $fh, '<', $file or return; local $/ = "\n"; defined(my $read_pid = <$fh>) or return; chomp $read_pid; if ($read_pid == $unlink_pid) { Net::Server::Daemonize::unlink_pid_file($file); } } sub master_loop { pipe(my ($p0, $p1)) or die "failed to create parent-pipe: $!"; pipe(my ($r, $w)) or die "failed to create self-pipe: $!"; if ($^O eq 'linux') { # 1031: F_SETPIPE_SZ = 1031 fcntl($_, 1031, 4096) for ($w, $p1); } IO::Handle::blocking($w, 0); my $set_workers = $worker_processes; my @caught; my $master_pid = $$; foreach my $s (qw(HUP CHLD QUIT INT TERM USR1 USR2 TTIN TTOU WINCH)) { $SIG{$s} = sub { return if $$ != $master_pid; push @caught, $s; syswrite($w, '.'); }; } reopen_logs(); # main loop my $quit = 0; while (1) { while (my $s = shift @caught) { if ($s eq 'USR1') { reopen_logs(); kill_workers($s); } elsif ($s eq 'USR2') { upgrade(); } elsif ($s =~ /\A(?:QUIT|TERM|INT)\z/) { exit if $quit++; kill_workers($s); } elsif ($s eq 'WINCH') { if (-t STDIN || -t STDOUT || -t STDERR) { warn "ignoring SIGWINCH since we are not daemonized\n"; $SIG{WINCH} = 'IGNORE'; } else { $worker_processes = 0; } } elsif ($s eq 'HUP') { $worker_processes = $set_workers; kill_workers($s); } elsif ($s eq 'TTIN') { if ($set_workers > $worker_processes) { ++$worker_processes; } else { $worker_processes = ++$set_workers; } } elsif ($s eq 'TTOU') { if ($set_workers > 0) { $worker_processes = --$set_workers; } } elsif ($s eq 'CHLD') { reap_children(); } } my $n = scalar keys %pids; if ($quit) { exit if $n == 0; $set_workers = $worker_processes = $n = 0; } if ($n > $worker_processes) { while (my ($k, $v) = each %pids) { kill('TERM', $k) if $v >= $worker_processes; } $n = $worker_processes; } foreach my $i ($n..($worker_processes - 1)) { my $pid = fork; if (!defined $pid) { warn "failed to fork worker[$i]: $!\n"; } elsif ($pid == 0) { $set_user->() if $set_user; return $p0; # run normal work code } else { warn "PID=$pid is worker[$i]\n"; $pids{$pid} = $i; } } # just wait on signal events here: sysread($r, my $buf, 8); } exit # never gets here, just for documentation } sub daemon_loop ($$) { my ($refresh, $post_accept) = @_; PublicInbox::EvCleanup::enable(); # early for $refresh my $parent_pipe; if ($worker_processes > 0) { $refresh->(); # preload by default my $fh = master_loop(); # returns if in child process $parent_pipe = PublicInbox::ParentPipe->new($fh, *worker_quit); } else { reopen_logs(); $set_user->() if $set_user; $SIG{USR2} = sub { worker_quit('USR2') if upgrade() }; $refresh->(); } $uid = $gid = undef; reopen_logs(); $SIG{QUIT} = $SIG{INT} = $SIG{TERM} = *worker_quit; $SIG{USR1} = *reopen_logs; $SIG{HUP} = $refresh; $SIG{CHLD} = 'DEFAULT'; $SIG{$_} = 'IGNORE' for qw(USR2 TTIN TTOU WINCH); # this calls epoll_create: @listeners = map { PublicInbox::Listener->new($_, $post_accept) } @listeners; PublicInbox::DS->EventLoop; $parent_pipe = undef; } sub run ($$$) { my ($default, $refresh, $post_accept) = @_; daemon_prepare($default); daemonize(); daemon_loop($refresh, $post_accept); } sub do_chown ($) { my ($path) = @_; if (defined $uid and !chown($uid, $gid, $path)) { warn "could not chown $path: $!\n"; } } sub write_pid ($) { my ($path) = @_; Net::Server::Daemonize::create_pid_file($path); do_chown($path); } 1;