1 # Copyright (C) 2016-2018 all contributors <meta@public-inbox.org>
2 # License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
4 # Generic PSGI server for convenience. It aims to provide
5 # a consistent experience for public-inbox admins so they don't have
6 # to learn different ways to admin both NNTP and HTTP components.
7 # There's nothing which depends on public-inbox, here.
8 # Each instance of this class represents a HTTP client socket
10 package PublicInbox::HTTP;
13 use base qw(PublicInbox::DS);
14 use fields qw(httpd env input_left remote_addr remote_port forward pull);
15 use bytes (); # only for bytes::length
17 use Plack::HTTPParser qw(parse_http_request); # XS or pure Perl
18 use HTTP::Status qw(status_message);
19 use HTTP::Date qw(time2str);
21 require PublicInbox::EvCleanup;
22 PublicInbox::DS->import(qw(msg_more));
23 use PublicInbox::Syscall qw(EPOLLIN EPOLLONESHOT);
25 CHUNK_START => -1, # [a-f0-9]+\r\n
26 CHUNK_END => -2, # \r\n
27 CHUNK_ZEND => -3, # \r\n
33 sub process_pipelineq () {
37 next unless $_->{sock};
42 # Use the same configuration parameter as git since this is primarily
43 # a slow-client sponge for git-http-backend
44 # TODO: support per-respository http.maxRequestBuffer somehow...
45 our $MAX_REQUEST_BUFFER = $ENV{GIT_HTTP_MAX_REQUEST_BUFFER} ||
48 open(my $null_io, '<', '/dev/null') or die "failed to open /dev/null: $!";
53 $now == $prev ? $http_date : ($http_date = time2str($prev = $now));
57 my ($class, $sock, $addr, $httpd) = @_;
58 my $self = fields::new($class);
59 $self->SUPER::new($sock, EPOLLIN | EPOLLONESHOT);
60 $self->{httpd} = $httpd;
61 ($self->{remote_addr}, $self->{remote_port}) =
62 PublicInbox::Daemon::host_with_port($addr);
66 sub event_step { # called by PublicInbox::DS
69 return unless $self->flush_write && $self->{sock};
71 # only read more requests if we've drained the write buffer,
72 # otherwise we can be buffering infinitely w/o backpressure
74 return read_input($self) if defined $self->{env};
75 my $rbuf = $self->{rbuf} // (\(my $x = ''));
76 $self->do_read($rbuf, 8192, bytes::length($$rbuf)) or return;
77 rbuf_process($self, $rbuf);
81 my ($self, $rbuf) = @_;
82 $rbuf //= $self->{rbuf} // (\(my $x = ''));
84 my %env = %{$self->{httpd}->{env}}; # full hash copy
85 my $r = parse_http_request($$rbuf, \%env);
87 # We do not support Trailers in chunked requests, for now
88 # (they are rarely-used and git (as of 2.7.2) does not use them)
89 if ($r == -1 || $env{HTTP_TRAILER} ||
90 # this length-check is necessary for PURE_PERL=1:
91 ($r == -2 && bytes::length($$rbuf) > 0x4000)) {
92 return quit($self, 400);
94 if ($r < 0) { # incomplete
95 $self->rbuf_idle($rbuf);
96 return $self->requeue;
98 $$rbuf = substr($$rbuf, $r);
99 my $len = input_prepare($self, \%env);
100 defined $len or return write_err($self, undef); # EMFILE/ENFILE
102 $len ? read_input($self, $rbuf) : app_dispatch($self, undef, $rbuf);
105 # IO::Handle::write returns boolean, this returns bytes written:
107 my ($fh, $rbuf, $max) = @_;
108 my $w = bytes::length($$rbuf);
109 $w = $max if $w > $max;
110 $fh->write($$rbuf, $w) or return;
114 sub read_input ($;$) {
115 my ($self, $rbuf) = @_;
116 $rbuf //= $self->{rbuf} // (\(my $x = ''));
117 my $env = $self->{env};
118 return if $env->{REMOTE_ADDR}; # in app dispatch
119 return read_input_chunked($self, $rbuf) if env_chunked($env);
121 # env->{CONTENT_LENGTH} (identity)
122 my $len = delete $self->{input_left};
123 my $input = $env->{'psgi.input'};
127 my $w = xwrite($input, $rbuf, $len);
128 return write_err($self, $len) unless $w;
130 die "BUG: $len < 0 (w=$w)" if $len < 0;
131 if ($len == 0) { # next request may be pipelined
132 $$rbuf = substr($$rbuf, $w);
137 $self->do_read($rbuf, 8192) or return recv_err($self, $len);
138 # continue looping if $r > 0;
140 app_dispatch($self, $input, $rbuf);
144 my ($self, $input, $rbuf) = @_;
145 $self->rbuf_idle($rbuf);
146 my $env = $self->{env};
147 $env->{REMOTE_ADDR} = $self->{remote_addr};
148 $env->{REMOTE_PORT} = $self->{remote_port};
149 if (my $host = $env->{HTTP_HOST}) {
150 $host =~ s/:([0-9]+)\z// and $env->{SERVER_PORT} = $1;
151 $env->{SERVER_NAME} = $host;
153 if (defined $input) {
154 sysseek($input, 0, SEEK_SET) or
155 die "BUG: psgi.input seek failed: $!";
157 # note: NOT $self->{sock}, we want our close (+ PublicInbox::DS::close),
158 # to do proper cleanup:
159 $env->{'psgix.io'} = $self; # only for ->close
160 my $res = Plack::Util::run_app($self->{httpd}->{app}, $env);
162 if (ref($res) eq 'CODE') {
163 $res->(sub { response_write($self, $env, $_[0]) });
165 response_write($self, $env, $res);
171 sub response_header_write {
172 my ($self, $env, $res) = @_;
173 my $proto = $env->{SERVER_PROTOCOL} or return; # HTTP/0.9 :P
174 my $status = $res->[0];
175 my $h = "$proto $status " . status_message($status) . "\r\n";
177 my $headers = $res->[1];
179 for (my $i = 0; $i < @$headers; $i += 2) {
180 my $k = $headers->[$i];
181 my $v = $headers->[$i + 1];
182 next if $k =~ /\A(?:Connection|Date)\z/i;
184 $len = $v if $k =~ /\AContent-Length\z/i;
185 if ($k =~ /\ATransfer-Encoding\z/i && $v =~ /\bchunked\b/i) {
191 my $conn = $env->{HTTP_CONNECTION} || '';
192 my $term = defined($len) || $chunked;
193 my $prot_persist = ($proto eq 'HTTP/1.1') && ($conn !~ /\bclose\b/i);
195 if (!$term && $prot_persist) { # auto-chunk
196 $chunked = $alive = 2;
197 $h .= "Transfer-Encoding: chunked\r\n";
198 # no need for "Connection: keep-alive" with HTTP/1.1
199 } elsif ($term && ($prot_persist || ($conn =~ /\bkeep-alive\b/i))) {
201 $h .= "Connection: keep-alive\r\n";
204 $h .= "Connection: close\r\n";
206 $h .= 'Date: ' . http_date() . "\r\n\r\n";
208 if (($len || $chunked) && $env->{REQUEST_METHOD} ne 'HEAD') {
216 # middlewares such as Deflater may write empty strings
217 sub chunked_wcb ($) {
220 return if $_[0] eq '';
221 msg_more($self, sprintf("%x\r\n", bytes::length($_[0])));
222 msg_more($self, $_[0]);
224 # use $self->write(\"\n\n") if you care about real-time
225 # streaming responses, public-inbox WWW does not.
226 msg_more($self, "\r\n");
230 sub identity_wcb ($) {
232 sub { $self->write(\($_[0])) if $_[0] ne '' }
235 sub next_request ($) {
238 # avoid recursion for pipelined requests
239 PublicInbox::DS::requeue(\&process_pipelineq) if !@$pipelineq;
240 push @$pipelineq, $self;
241 } else { # wait for next request
246 sub response_done_cb ($$) {
247 my ($self, $alive) = @_;
249 my $env = delete $self->{env};
250 $self->write(\"0\r\n\r\n") if $alive == 2;
251 $self->write($alive ? \&next_request : \&close);
255 sub getline_cb ($$$) {
256 my ($self, $write, $close) = @_;
258 my $forward = $self->{forward};
259 # limit our own running time for fairness with other
260 # clients and to avoid buffering too much:
262 my $buf = eval { $forward->getline };
264 $write->($buf); # may close in PublicInbox::DS::write
266 my $next = $self->{pull};
270 PublicInbox::DS::requeue($next);
275 err($self, "response ->getline error: $@");
281 delete @$self{qw(forward pull)};
284 eval { $forward->close };
286 err($self, "response ->close error: $@");
287 $self->close; # idempotent
293 sub getline_response ($$$) {
294 my ($self, $write, $close) = @_;
295 my $pull = $self->{pull} = sub { getline_cb($self, $write, $close) };
300 my ($self, $env, $res) = @_;
301 my $alive = response_header_write($self, $env, $res);
302 my $close = response_done_cb($self, $alive);
303 my $write = $alive == 2 ? chunked_wcb($self) : identity_wcb($self);
304 if (defined(my $body = $res->[2])) {
305 if (ref $body eq 'ARRAY') {
306 $write->($_) foreach @$body;
309 $self->{forward} = $body;
310 getline_response($self, $write, $close);
313 # this is returned to the calling application:
314 Plack::Util::inline_object(write => $write, close => $close);
318 sub input_tmpfile ($) {
319 open($_[0], '+>', undef);
324 my ($self, $env) = @_;
326 my $len = $env->{CONTENT_LENGTH};
328 if ($len > $MAX_REQUEST_BUFFER) {
332 input_tmpfile($input);
333 } elsif (env_chunked($env)) {
335 input_tmpfile($input);
340 # TODO: expire idle clients on ENFILE / EMFILE
341 return unless $input;
343 $env->{'psgi.input'} = $input;
345 $self->{input_left} = $len || 0;
348 sub env_chunked { ($_[0]->{HTTP_TRANSFER_ENCODING} || '') =~ /\bchunked\b/i }
351 eval { $_[0]->{httpd}->{env}->{'psgi.errors'}->print($_[1]."\n") };
355 my ($self, $len) = @_;
356 my $msg = $! || '(zero write)';
357 $msg .= " ($len bytes remaining)" if defined $len;
358 err($self, "error buffering to input: $msg");
363 my ($self, $len) = @_;
364 if ($! == EAGAIN) { # epoll/kevent watch already set by do_read
365 $self->{input_left} = $len;
367 err($self, "error reading input: $! ($len bytes remaining)");
371 sub read_input_chunked { # unlikely...
372 my ($self, $rbuf) = @_;
373 $rbuf //= $self->{rbuf} // (\(my $x = ''));
374 my $input = $self->{env}->{'psgi.input'};
375 my $len = delete $self->{input_left};
377 while (1) { # chunk start
378 if ($len == CHUNK_ZEND) {
379 $$rbuf =~ s/\A\r\n//s and
380 return app_dispatch($self, $input, $rbuf);
382 return quit($self, 400) if bytes::length($$rbuf) > 2;
384 if ($len == CHUNK_END) {
385 if ($$rbuf =~ s/\A\r\n//s) {
387 } elsif (bytes::length($$rbuf) > 2) {
388 return quit($self, 400);
391 if ($len == CHUNK_START) {
392 if ($$rbuf =~ s/\A([a-f0-9]+).*?\r\n//i) {
394 if (($len + -s $input) > $MAX_REQUEST_BUFFER) {
395 return quit($self, 413);
397 } elsif (bytes::length($$rbuf) > CHUNK_MAX_HDR) {
398 return quit($self, 400);
400 # will break from loop since $len >= 0
403 if ($len < 0) { # chunk header is trickled, read more
404 $self->do_read($rbuf, 8192, bytes::length($$rbuf)) or
405 return recv_err($self, $len);
406 # (implicit) goto chunk_start if $r > 0;
408 $len = CHUNK_ZEND if $len == 0;
410 # drain the current chunk
413 my $w = xwrite($input, $rbuf, $len);
414 return write_err($self, "$len chunk") if !$w;
417 # we may have leftover data to parse
419 $$rbuf = substr($$rbuf, $w);
422 die "BUG: len < 0: $len";
428 # read more of current chunk
429 $self->do_read($rbuf, 8192) or
430 return recv_err($self, $len);
437 my ($self, $status) = @_;
438 my $h = "HTTP/1.1 $status " . status_message($status) . "\r\n\r\n";
445 if (my $env = delete $self->{env}) {
446 delete $env->{'psgix.io'}; # prevent circular references
448 delete $self->{pull};
449 if (my $forward = delete $self->{forward}) {
450 eval { $forward->close };
451 err($self, "forward ->close error: $@") if $@;
453 $self->SUPER::close; # PublicInbox::DS::close
456 # for graceful shutdown in PublicInbox::Daemon:
459 ($self->{rbuf} || $self->{env} || $self->{wbuf});
462 # fires after pending writes are complete:
463 sub restart_pass ($) {
464 $_[0]->{forward}->restart_read; # see PublicInbox::HTTPD::Async
467 sub enqueue_restart_pass ($) { $_[0]->write(\&restart_pass) }