# Copyright (C) 2016-2018 all contributors # License: AGPL-3.0+ # # Generic PSGI server for convenience. It aims to provide # a consistent experience for public-inbox admins so they don't have # to learn different ways to admin both NNTP and HTTP components. # There's nothing which depends on public-inbox, here. # Each instance of this class represents a HTTP client socket package PublicInbox::HTTP; use strict; use warnings; use base qw(Danga::Socket); use fields qw(httpd env rbuf input_left remote_addr remote_port forward pull); use Fcntl qw(:seek); use Plack::HTTPParser qw(parse_http_request); # XS or pure Perl use HTTP::Status qw(status_message); use HTTP::Date qw(time2str); use IO::Handle; use constant { CHUNK_START => -1, # [a-f0-9]+\r\n CHUNK_END => -2, # \r\n CHUNK_ZEND => -3, # \r\n CHUNK_MAX_HDR => 256, }; my $pipelineq = []; my $pipet; sub process_pipelineq () { my $q = $pipelineq; $pipet = undef; $pipelineq = []; foreach (@$q) { next if $_->{closed}; rbuf_process($_); } } # Use the same configuration parameter as git since this is primarily # a slow-client sponge for git-http-backend # TODO: support per-respository http.maxRequestBuffer somehow... our $MAX_REQUEST_BUFFER = $ENV{GIT_HTTP_MAX_REQUEST_BUFFER} || (10 * 1024 * 1024); open(my $null_io, '<', '/dev/null') or die "failed to open /dev/null: $!"; my $http_date; my $prev = 0; sub http_date () { my $now = time; $now == $prev ? $http_date : ($http_date = time2str($prev = $now)); } sub new ($$$) { my ($class, $sock, $addr, $httpd) = @_; my $self = fields::new($class); $self->SUPER::new($sock); $self->{httpd} = $httpd; $self->{rbuf} = ''; ($self->{remote_addr}, $self->{remote_port}) = PublicInbox::Daemon::host_with_port($addr); $self->watch_read(1); $self; } sub event_read { # called by Danga::Socket my ($self) = @_; return event_read_input($self) if defined $self->{env}; my $off = length($self->{rbuf}); my $r = sysread($self->{sock}, $self->{rbuf}, 8192, $off); if (defined $r) { return $self->close if $r == 0; return rbuf_process($self); } return if $!{EAGAIN}; # no need to call watch_read(1) again # common for clients to break connections without warning, # would be too noisy to log here: return $self->close; } sub rbuf_process { my ($self) = @_; my %env = %{$self->{httpd}->{env}}; # full hash copy my $r = parse_http_request($self->{rbuf}, \%env); # We do not support Trailers in chunked requests, for now # (they are rarely-used and git (as of 2.7.2) does not use them) if ($r == -1 || $env{HTTP_TRAILER} || # this length-check is necessary for PURE_PERL=1: ($r == -2 && length($self->{rbuf}) > 0x4000)) { return quit($self, 400); } return $self->watch_read(1) if $r < 0; # incomplete $self->{rbuf} = substr($self->{rbuf}, $r); my $len = input_prepare($self, \%env); defined $len or return write_err($self, undef); # EMFILE/ENFILE $len ? event_read_input($self) : app_dispatch($self); } sub event_read_input ($) { my ($self) = @_; my $env = $self->{env}; return event_read_input_chunked($self) if env_chunked($env); # env->{CONTENT_LENGTH} (identity) my $sock = $self->{sock}; my $len = $self->{input_left}; $self->{input_left} = undef; my $rbuf = \($self->{rbuf}); my $input = $env->{'psgi.input'}; while ($len > 0) { if ($$rbuf ne '') { my $w = write_in_full($input, $rbuf, $len); return write_err($self, $len) unless $w; $len -= $w; die "BUG: $len < 0 (w=$w)" if $len < 0; if ($len == 0) { # next request may be pipelined $$rbuf = substr($$rbuf, $w); last; } $$rbuf = ''; } my $r = sysread($sock, $$rbuf, 8192); return recv_err($self, $r, $len) unless $r; # continue looping if $r > 0; } app_dispatch($self, $input); } sub app_dispatch { my ($self, $input) = @_; $self->watch_read(0); my $env = $self->{env}; $env->{REMOTE_ADDR} = $self->{remote_addr}; $env->{REMOTE_PORT} = $self->{remote_port}; if (my $host = $env->{HTTP_HOST}) { $host =~ s/:(\d+)\z// and $env->{SERVER_PORT} = $1; $env->{SERVER_NAME} = $host; } if (defined $input) { sysseek($input, 0, SEEK_SET) or die "BUG: psgi.input seek failed: $!"; } # note: NOT $self->{sock}, we want our close (+ Danga::Socket::close), # to do proper cleanup: $env->{'psgix.io'} = $self; # only for ->close my $res = Plack::Util::run_app($self->{httpd}->{app}, $env); eval { if (ref($res) eq 'CODE') { $res->(sub { response_write($self, $env, $_[0]) }); } else { response_write($self, $env, $res); } }; $self->close if $@; } sub response_header_write { my ($self, $env, $res) = @_; my $proto = $env->{SERVER_PROTOCOL} or return; # HTTP/0.9 :P my $status = $res->[0]; my $h = "$proto $status " . status_message($status) . "\r\n"; my ($len, $chunked); my $headers = $res->[1]; for (my $i = 0; $i < @$headers; $i += 2) { my $k = $headers->[$i]; my $v = $headers->[$i + 1]; next if $k =~ /\A(?:Connection|Date)\z/i; $len = $v if $k =~ /\AContent-Length\z/i; if ($k =~ /\ATransfer-Encoding\z/i && $v =~ /\bchunked\b/i) { $chunked = 1; } $h .= "$k: $v\r\n"; } my $conn = $env->{HTTP_CONNECTION} || ''; my $term = defined($len) || $chunked; my $prot_persist = ($proto eq 'HTTP/1.1') && ($conn !~ /\bclose\b/i); my $alive; if (!$term && $prot_persist) { # auto-chunk $chunked = $alive = 2; $h .= "Transfer-Encoding: chunked\r\n"; # no need for "Connection: keep-alive" with HTTP/1.1 } elsif ($term && ($prot_persist || ($conn =~ /\bkeep-alive\b/i))) { $alive = 1; $h .= "Connection: keep-alive\r\n"; } else { $alive = 0; $h .= "Connection: close\r\n"; } $h .= 'Date: ' . http_date() . "\r\n\r\n"; if (($len || $chunked) && $env->{REQUEST_METHOD} ne 'HEAD') { more($self, $h); } else { $self->write($h); } $alive; } # middlewares such as Deflater may write empty strings sub chunked_wcb ($) { my ($self) = @_; sub { return if $_[0] eq ''; more($self, sprintf("%x\r\n", bytes::length($_[0]))); more($self, $_[0]); # use $self->write("\n\n") if you care about real-time # streaming responses, public-inbox WWW does not. more($self, "\r\n"); } } sub identity_wcb ($) { my ($self) = @_; sub { $self->write(\($_[0])) if $_[0] ne '' } } sub next_request ($) { my ($self) = @_; $self->watch_write(0); if ($self->{rbuf} eq '') { # wait for next request $self->watch_read(1); } else { # avoid recursion for pipelined requests push @$pipelineq, $self; $pipet ||= PublicInbox::EvCleanup::asap(*process_pipelineq); } } sub response_done_cb ($$) { my ($self, $alive) = @_; sub { my $env = $self->{env}; $self->{env} = undef; $self->write("0\r\n\r\n") if $alive == 2; $self->write(sub{$alive ? next_request($self) : $self->close}); } } sub getline_cb ($$$) { my ($self, $write, $close) = @_; local $/ = \8192; my $forward = $self->{forward}; # limit our own running time for fairness with other # clients and to avoid buffering too much: if ($forward) { my $buf = eval { $forward->getline }; if (defined $buf) { $write->($buf); # may close in Danga::Socket::write unless ($self->{closed}) { my $next = $self->{pull}; if ($self->{write_buf_size}) { $self->write($next); } else { PublicInbox::EvCleanup::asap($next); } return; } } elsif ($@) { err($self, "response ->getline error: $@"); $forward = undef; $self->close; } } $self->{forward} = $self->{pull} = undef; # avoid recursion if ($forward) { eval { $forward->close }; if ($@) { err($self, "response ->close error: $@"); $self->close; # idempotent } } $close->(); } sub getline_response ($$$) { my ($self, $write, $close) = @_; my $pull = $self->{pull} = sub { getline_cb($self, $write, $close) }; $pull->(); } sub response_write { my ($self, $env, $res) = @_; my $alive = response_header_write($self, $env, $res); my $close = response_done_cb($self, $alive); my $write = $alive == 2 ? chunked_wcb($self) : identity_wcb($self); if (defined(my $body = $res->[2])) { if (ref $body eq 'ARRAY') { $write->($_) foreach @$body; $close->(); } else { $self->{forward} = $body; getline_response($self, $write, $close); } } else { # this is returned to the calling application: Plack::Util::inline_object(write => $write, close => $close); } } use constant MSG_MORE => ($^O eq 'linux') ? 0x8000 : 0; sub more ($$) { my $self = $_[0]; return if $self->{closed}; if (MSG_MORE && !$self->{write_buf_size}) { my $n = send($self->{sock}, $_[1], MSG_MORE); if (defined $n) { my $nlen = length($_[1]) - $n; return 1 if $nlen == 0; # all done! eval { $_[1] = substr($_[1], $n, $nlen) }; if ($@) { # modification of read-only value: return $self->write(substr($_[1], $n, $nlen)); } # fall through to normal write: } } $self->write($_[1]); } sub input_prepare { my ($self, $env) = @_; my $input; my $len = $env->{CONTENT_LENGTH}; if ($len) { if ($len > $MAX_REQUEST_BUFFER) { quit($self, 413); return; } open($input, '+>', undef); } elsif (env_chunked($env)) { $len = CHUNK_START; open($input, '+>', undef); } else { $input = $null_io; } # TODO: expire idle clients on ENFILE / EMFILE return unless $input; $env->{'psgi.input'} = $input; $self->{env} = $env; $self->{input_left} = $len || 0; } sub env_chunked { ($_[0]->{HTTP_TRANSFER_ENCODING} || '') =~ /\bchunked\b/i } sub err ($$) { eval { $_[0]->{httpd}->{env}->{'psgi.errors'}->print($_[1]."\n") }; } sub write_err { my ($self, $len) = @_; my $msg = $! || '(zero write)'; $msg .= " ($len bytes remaining)" if defined $len; err($self, "error buffering to input: $msg"); quit($self, 500); } sub recv_err { my ($self, $r, $len) = @_; return $self->close if (defined $r && $r == 0); if ($!{EAGAIN}) { $self->{input_left} = $len; return; } err($self, "error reading for input: $! ($len bytes remaining)"); quit($self, 500); } sub write_in_full { my ($fh, $rbuf, $len) = @_; my $rv = 0; my $off = 0; while ($len > 0) { my $w = syswrite($fh, $$rbuf, $len, $off); return ($rv ? $rv : $w) unless $w; # undef or 0 $rv += $w; $off += $w; $len -= $w; } $rv } sub event_read_input_chunked { # unlikely... my ($self) = @_; my $input = $self->{env}->{'psgi.input'}; my $sock = $self->{sock}; my $len = $self->{input_left}; $self->{input_left} = undef; my $rbuf = \($self->{rbuf}); while (1) { # chunk start if ($len == CHUNK_ZEND) { $$rbuf =~ s/\A\r\n//s and return app_dispatch($self, $input); return quit($self, 400) if length($$rbuf) > 2; } if ($len == CHUNK_END) { if ($$rbuf =~ s/\A\r\n//s) { $len = CHUNK_START; } elsif (length($$rbuf) > 2) { return quit($self, 400); } } if ($len == CHUNK_START) { if ($$rbuf =~ s/\A([a-f0-9]+).*?\r\n//i) { $len = hex $1; if (($len + -s $input) > $MAX_REQUEST_BUFFER) { return quit($self, 413); } } elsif (length($$rbuf) > CHUNK_MAX_HDR) { return quit($self, 400); } # will break from loop since $len >= 0 } if ($len < 0) { # chunk header is trickled, read more my $off = length($$rbuf); my $r = sysread($sock, $$rbuf, 8192, $off); return recv_err($self, $r, $len) unless $r; # (implicit) goto chunk_start if $r > 0; } $len = CHUNK_ZEND if $len == 0; # drain the current chunk until ($len <= 0) { if ($$rbuf ne '') { my $w = write_in_full($input, $rbuf, $len); return write_err($self, "$len chunk") if !$w; $len -= $w; if ($len == 0) { # we may have leftover data to parse # in chunk $$rbuf = substr($$rbuf, $w); $len = CHUNK_END; } elsif ($len < 0) { die "BUG: len < 0: $len"; } else { $$rbuf = ''; } } if ($$rbuf eq '') { # read more of current chunk my $r = sysread($sock, $$rbuf, 8192); return recv_err($self, $r, $len) unless $r; } } } } sub quit { my ($self, $status) = @_; my $h = "HTTP/1.1 $status " . status_message($status) . "\r\n\r\n"; $self->write($h); $self->close; } # callbacks for Danga::Socket sub event_hup { $_[0]->close } sub event_err { $_[0]->close } sub close { my $self = shift; my $forward = $self->{forward}; my $env = $self->{env}; delete $env->{'psgix.io'} if $env; # prevent circular references $self->{pull} = $self->{forward} = $self->{env} = undef; if ($forward) { eval { $forward->close }; err($self, "forward ->close error: $@") if $@; } $self->SUPER::close(@_); } # for graceful shutdown in PublicInbox::Daemon: sub busy () { my ($self) = @_; ($self->{rbuf} ne '' || $self->{env} || $self->{write_buf_size}); } 1;