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
34 sub process_pipelineq () {
39 next unless $_->{sock};
44 # Use the same configuration parameter as git since this is primarily
45 # a slow-client sponge for git-http-backend
46 # TODO: support per-respository http.maxRequestBuffer somehow...
47 our $MAX_REQUEST_BUFFER = $ENV{GIT_HTTP_MAX_REQUEST_BUFFER} ||
50 open(my $null_io, '<', '/dev/null') or die "failed to open /dev/null: $!";
55 $now == $prev ? $http_date : ($http_date = time2str($prev = $now));
59 my ($class, $sock, $addr, $httpd) = @_;
60 my $self = fields::new($class);
61 $self->SUPER::new($sock, EPOLLIN | EPOLLONESHOT);
62 $self->{httpd} = $httpd;
63 ($self->{remote_addr}, $self->{remote_port}) =
64 PublicInbox::Daemon::host_with_port($addr);
68 sub event_step { # called by PublicInbox::DS
71 return unless $self->flush_write && $self->{sock};
73 # only read more requests if we've drained the write buffer,
74 # otherwise we can be buffering infinitely w/o backpressure
76 return read_input($self) if defined $self->{env};
77 my $rbuf = $self->{rbuf} // (\(my $x = ''));
78 $self->do_read($rbuf, 8192, bytes::length($$rbuf)) or return;
79 rbuf_process($self, $rbuf);
83 my ($self, $rbuf) = @_;
84 $rbuf //= $self->{rbuf} // (\(my $x = ''));
86 my %env = %{$self->{httpd}->{env}}; # full hash copy
87 my $r = parse_http_request($$rbuf, \%env);
89 # We do not support Trailers in chunked requests, for now
90 # (they are rarely-used and git (as of 2.7.2) does not use them)
91 if ($r == -1 || $env{HTTP_TRAILER} ||
92 # this length-check is necessary for PURE_PERL=1:
93 ($r == -2 && bytes::length($$rbuf) > 0x4000)) {
94 return quit($self, 400);
96 if ($r < 0) { # incomplete
97 $self->rbuf_idle($rbuf);
98 return $self->requeue;
100 $$rbuf = substr($$rbuf, $r);
101 my $len = input_prepare($self, \%env);
102 defined $len or return write_err($self, undef); # EMFILE/ENFILE
104 $len ? read_input($self, $rbuf) : app_dispatch($self, undef, $rbuf);
107 # IO::Handle::write returns boolean, this returns bytes written:
109 my ($fh, $rbuf, $max) = @_;
110 my $w = bytes::length($$rbuf);
111 $w = $max if $w > $max;
112 $fh->write($$rbuf, $w) or return;
116 sub read_input ($;$) {
117 my ($self, $rbuf) = @_;
118 $rbuf //= $self->{rbuf} // (\(my $x = ''));
119 my $env = $self->{env};
120 return if $env->{REMOTE_ADDR}; # in app dispatch
121 return read_input_chunked($self, $rbuf) if env_chunked($env);
123 # env->{CONTENT_LENGTH} (identity)
124 my $len = delete $self->{input_left};
125 my $input = $env->{'psgi.input'};
129 my $w = xwrite($input, $rbuf, $len);
130 return write_err($self, $len) unless $w;
132 die "BUG: $len < 0 (w=$w)" if $len < 0;
133 if ($len == 0) { # next request may be pipelined
134 $$rbuf = substr($$rbuf, $w);
139 $self->do_read($rbuf, 8192) or return recv_err($self, $len);
140 # continue looping if $r > 0;
142 app_dispatch($self, $input, $rbuf);
146 my ($self, $input, $rbuf) = @_;
147 $self->rbuf_idle($rbuf);
148 my $env = $self->{env};
149 $env->{REMOTE_ADDR} = $self->{remote_addr};
150 $env->{REMOTE_PORT} = $self->{remote_port};
151 if (my $host = $env->{HTTP_HOST}) {
152 $host =~ s/:([0-9]+)\z// and $env->{SERVER_PORT} = $1;
153 $env->{SERVER_NAME} = $host;
155 if (defined $input) {
156 sysseek($input, 0, SEEK_SET) or
157 die "BUG: psgi.input seek failed: $!";
159 # note: NOT $self->{sock}, we want our close (+ PublicInbox::DS::close),
160 # to do proper cleanup:
161 $env->{'psgix.io'} = $self; # only for ->close
162 my $res = Plack::Util::run_app($self->{httpd}->{app}, $env);
164 if (ref($res) eq 'CODE') {
165 $res->(sub { response_write($self, $env, $_[0]) });
167 response_write($self, $env, $res);
173 sub response_header_write {
174 my ($self, $env, $res) = @_;
175 my $proto = $env->{SERVER_PROTOCOL} or return; # HTTP/0.9 :P
176 my $status = $res->[0];
177 my $h = "$proto $status " . status_message($status) . "\r\n";
179 my $headers = $res->[1];
181 for (my $i = 0; $i < @$headers; $i += 2) {
182 my $k = $headers->[$i];
183 my $v = $headers->[$i + 1];
184 next if $k =~ /\A(?:Connection|Date)\z/i;
186 $len = $v if $k =~ /\AContent-Length\z/i;
187 if ($k =~ /\ATransfer-Encoding\z/i && $v =~ /\bchunked\b/i) {
193 my $conn = $env->{HTTP_CONNECTION} || '';
194 my $term = defined($len) || $chunked;
195 my $prot_persist = ($proto eq 'HTTP/1.1') && ($conn !~ /\bclose\b/i);
197 if (!$term && $prot_persist) { # auto-chunk
198 $chunked = $alive = 2;
199 $h .= "Transfer-Encoding: chunked\r\n";
200 # no need for "Connection: keep-alive" with HTTP/1.1
201 } elsif ($term && ($prot_persist || ($conn =~ /\bkeep-alive\b/i))) {
203 $h .= "Connection: keep-alive\r\n";
206 $h .= "Connection: close\r\n";
208 $h .= 'Date: ' . http_date() . "\r\n\r\n";
210 if (($len || $chunked) && $env->{REQUEST_METHOD} ne 'HEAD') {
218 # middlewares such as Deflater may write empty strings
219 sub chunked_wcb ($) {
222 return if $_[0] eq '';
223 msg_more($self, sprintf("%x\r\n", bytes::length($_[0])));
224 msg_more($self, $_[0]);
226 # use $self->write(\"\n\n") if you care about real-time
227 # streaming responses, public-inbox WWW does not.
228 msg_more($self, "\r\n");
232 sub identity_wcb ($) {
234 sub { $self->write(\($_[0])) if $_[0] ne '' }
237 sub next_request ($) {
240 # avoid recursion for pipelined requests
241 push @$pipelineq, $self;
242 $pipet ||= PublicInbox::EvCleanup::asap(*process_pipelineq);
243 } else { # wait for next request
248 sub response_done_cb ($$) {
249 my ($self, $alive) = @_;
251 my $env = delete $self->{env};
252 $self->write(\"0\r\n\r\n") if $alive == 2;
253 $self->write($alive ? \&next_request : \&close);
257 sub getline_cb ($$$) {
258 my ($self, $write, $close) = @_;
260 my $forward = $self->{forward};
261 # limit our own running time for fairness with other
262 # clients and to avoid buffering too much:
264 my $buf = eval { $forward->getline };
266 $write->($buf); # may close in PublicInbox::DS::write
268 my $next = $self->{pull};
272 PublicInbox::EvCleanup::asap($next);
277 err($self, "response ->getline error: $@");
283 delete @$self{qw(forward pull)};
286 eval { $forward->close };
288 err($self, "response ->close error: $@");
289 $self->close; # idempotent
295 sub getline_response ($$$) {
296 my ($self, $write, $close) = @_;
297 my $pull = $self->{pull} = sub { getline_cb($self, $write, $close) };
302 my ($self, $env, $res) = @_;
303 my $alive = response_header_write($self, $env, $res);
304 my $close = response_done_cb($self, $alive);
305 my $write = $alive == 2 ? chunked_wcb($self) : identity_wcb($self);
306 if (defined(my $body = $res->[2])) {
307 if (ref $body eq 'ARRAY') {
308 $write->($_) foreach @$body;
311 $self->{forward} = $body;
312 getline_response($self, $write, $close);
315 # this is returned to the calling application:
316 Plack::Util::inline_object(write => $write, close => $close);
320 sub input_tmpfile ($) {
321 open($_[0], '+>', undef);
326 my ($self, $env) = @_;
328 my $len = $env->{CONTENT_LENGTH};
330 if ($len > $MAX_REQUEST_BUFFER) {
334 input_tmpfile($input);
335 } elsif (env_chunked($env)) {
337 input_tmpfile($input);
342 # TODO: expire idle clients on ENFILE / EMFILE
343 return unless $input;
345 $env->{'psgi.input'} = $input;
347 $self->{input_left} = $len || 0;
350 sub env_chunked { ($_[0]->{HTTP_TRANSFER_ENCODING} || '') =~ /\bchunked\b/i }
353 eval { $_[0]->{httpd}->{env}->{'psgi.errors'}->print($_[1]."\n") };
357 my ($self, $len) = @_;
358 my $msg = $! || '(zero write)';
359 $msg .= " ($len bytes remaining)" if defined $len;
360 err($self, "error buffering to input: $msg");
365 my ($self, $len) = @_;
366 if ($! == EAGAIN) { # epoll/kevent watch already set by do_read
367 $self->{input_left} = $len;
369 err($self, "error reading input: $! ($len bytes remaining)");
373 sub read_input_chunked { # unlikely...
374 my ($self, $rbuf) = @_;
375 $rbuf //= $self->{rbuf} // (\(my $x = ''));
376 my $input = $self->{env}->{'psgi.input'};
377 my $len = delete $self->{input_left};
379 while (1) { # chunk start
380 if ($len == CHUNK_ZEND) {
381 $$rbuf =~ s/\A\r\n//s and
382 return app_dispatch($self, $input, $rbuf);
384 return quit($self, 400) if bytes::length($$rbuf) > 2;
386 if ($len == CHUNK_END) {
387 if ($$rbuf =~ s/\A\r\n//s) {
389 } elsif (bytes::length($$rbuf) > 2) {
390 return quit($self, 400);
393 if ($len == CHUNK_START) {
394 if ($$rbuf =~ s/\A([a-f0-9]+).*?\r\n//i) {
396 if (($len + -s $input) > $MAX_REQUEST_BUFFER) {
397 return quit($self, 413);
399 } elsif (bytes::length($$rbuf) > CHUNK_MAX_HDR) {
400 return quit($self, 400);
402 # will break from loop since $len >= 0
405 if ($len < 0) { # chunk header is trickled, read more
406 $self->do_read($rbuf, 8192, bytes::length($$rbuf)) or
407 return recv_err($self, $len);
408 # (implicit) goto chunk_start if $r > 0;
410 $len = CHUNK_ZEND if $len == 0;
412 # drain the current chunk
415 my $w = xwrite($input, $rbuf, $len);
416 return write_err($self, "$len chunk") if !$w;
419 # we may have leftover data to parse
421 $$rbuf = substr($$rbuf, $w);
424 die "BUG: len < 0: $len";
430 # read more of current chunk
431 $self->do_read($rbuf, 8192) or
432 return recv_err($self, $len);
439 my ($self, $status) = @_;
440 my $h = "HTTP/1.1 $status " . status_message($status) . "\r\n\r\n";
447 if (my $env = delete $self->{env}) {
448 delete $env->{'psgix.io'}; # prevent circular references
450 delete $self->{pull};
451 if (my $forward = delete $self->{forward}) {
452 eval { $forward->close };
453 err($self, "forward ->close error: $@") if $@;
455 $self->SUPER::close; # PublicInbox::DS::close
458 # for graceful shutdown in PublicInbox::Daemon:
461 ($self->{rbuf} || $self->{env} || $self->{wbuf});
464 # fires after pending writes are complete:
465 sub restart_pass ($) {
466 $_[0]->{forward}->restart_read; # see PublicInbox::HTTPD::Async
469 sub enqueue_restart_pass ($) { $_[0]->write(\&restart_pass) }