1 # Copyright (C) 2016-2021 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
11 # httpd: PublicInbox::HTTPD ref
12 # env: PSGI env hashref
13 # input_left: bytes left to read in request body (e.g. POST/PUT)
14 # remote_addr: remote IP address as a string (e.g. "127.0.0.1")
15 # remote_port: peer port
16 # forward: response body object, response to ->getline + ->close
17 # alive: HTTP keepalive state:
18 # 0: drop connection when done
19 # 1: keep connection when done
20 # 2: keep connection, chunk responses
21 package PublicInbox::HTTP;
23 use parent qw(PublicInbox::DS);
25 use Plack::HTTPParser qw(parse_http_request); # XS or pure Perl
27 use HTTP::Status qw(status_message);
28 use HTTP::Date qw(time2str);
29 use PublicInbox::DS qw(msg_more);
30 use PublicInbox::Syscall qw(EPOLLIN EPOLLONESHOT);
31 use PublicInbox::Tmpfile;
33 CHUNK_START => -1, # [a-f0-9]+\r\n
34 CHUNK_END => -2, # \r\n
35 CHUNK_ZEND => -3, # \r\n
40 # Use the same configuration parameter as git since this is primarily
41 # a slow-client sponge for git-http-backend
42 # TODO: support per-respository http.maxRequestBuffer somehow...
43 our $MAX_REQUEST_BUFFER = $ENV{GIT_HTTP_MAX_REQUEST_BUFFER} ||
46 open(my $null_io, '<', '/dev/null') or die "failed to open /dev/null: $!";
51 $now == $prev ? $http_date : ($http_date = time2str($prev = $now));
55 my ($class, $sock, $addr, $httpd) = @_;
56 my $self = bless { httpd => $httpd }, $class;
59 if ($sock->can('accept_SSL') && !$sock->accept_SSL) {
60 return CORE::close($sock) if $! != EAGAIN;
61 $ev = PublicInbox::TLS::epollbit() or return CORE::close($sock);
62 $wbuf = [ \&PublicInbox::DS::accept_tls_step ];
64 $self->{wbuf} = $wbuf if $wbuf;
65 ($self->{remote_addr}, $self->{remote_port}) =
66 PublicInbox::Daemon::host_with_port($addr);
67 $self->SUPER::new($sock, $ev | EPOLLONESHOT);
70 sub event_step { # called by PublicInbox::DS
73 return unless $self->flush_write && $self->{sock};
75 # only read more requests if we've drained the write buffer,
76 # otherwise we can be buffering infinitely w/o backpressure
78 return read_input($self) if ref($self->{env});
80 my $rbuf = $self->{rbuf} // (\(my $x = ''));
81 my %env = %{$self->{httpd}->{env}}; # full hash copy
83 while (($r = parse_http_request($$rbuf, \%env)) < 0) {
84 # We do not support Trailers in chunked requests, for
85 # now (they are rarely-used and git (as of 2.7.2) does
87 # this length-check is necessary for PURE_PERL=1:
88 if ($r == -1 || $env{HTTP_TRAILER} ||
89 ($r == -2 && length($$rbuf) > 0x4000)) {
90 return quit($self, 400);
92 $self->do_read($rbuf, 8192, length($$rbuf)) or return;
94 $$rbuf = substr($$rbuf, $r);
95 my $len = input_prepare($self, \%env) //
96 return write_err($self, undef); # EMFILE/ENFILE
98 $len ? read_input($self, $rbuf) : app_dispatch($self, undef, $rbuf);
101 sub read_input ($;$) {
102 my ($self, $rbuf) = @_;
103 $rbuf //= $self->{rbuf} // (\(my $x = ''));
104 my $env = $self->{env};
105 return read_input_chunked($self, $rbuf) if env_chunked($env);
107 # env->{CONTENT_LENGTH} (identity)
108 my $len = delete $self->{input_left};
109 my $input = $env->{'psgi.input'};
113 my $w = syswrite($input, $$rbuf, $len);
114 return write_err($self, $len) unless $w;
116 die "BUG: $len < 0 (w=$w)" if $len < 0;
117 if ($len == 0) { # next request may be pipelined
118 $$rbuf = substr($$rbuf, $w);
123 $self->do_read($rbuf, 8192) or return recv_err($self, $len);
124 # continue looping if $r > 0;
126 app_dispatch($self, $input, $rbuf);
130 my ($self, $input, $rbuf) = @_;
131 $self->rbuf_idle($rbuf);
132 my $env = $self->{env};
133 $self->{env} = undef; # for exists() check in ->busy
134 $env->{REMOTE_ADDR} = $self->{remote_addr};
135 $env->{REMOTE_PORT} = $self->{remote_port};
136 if (defined(my $host = $env->{HTTP_HOST})) {
137 $host =~ s/:([0-9]+)\z// and $env->{SERVER_PORT} = $1;
138 $env->{SERVER_NAME} = $host;
140 if (defined $input) {
141 sysseek($input, 0, SEEK_SET) or
142 die "BUG: psgi.input seek failed: $!";
144 # note: NOT $self->{sock}, we want our close (+ PublicInbox::DS::close),
145 # to do proper cleanup:
146 $env->{'psgix.io'} = $self; # for ->close or async_pass
147 my $res = Plack::Util::run_app($self->{httpd}->{app}, $env);
149 if (ref($res) eq 'CODE') {
150 $res->(sub { response_write($self, $env, $_[0]) });
152 response_write($self, $env, $res);
156 warn "response_write error: $@";
161 sub response_header_write {
162 my ($self, $env, $res) = @_;
163 my $proto = $env->{SERVER_PROTOCOL} or return; # HTTP/0.9 :P
164 my $status = $res->[0];
165 my $h = "$proto $status " . status_message($status) . "\r\n";
167 my $headers = $res->[1];
169 for (my $i = 0; $i < @$headers; $i += 2) {
170 my $k = $headers->[$i];
171 my $v = $headers->[$i + 1];
172 next if $k =~ /\A(?:Connection|Date)\z/i;
174 $len = $v if $k =~ /\AContent-Length\z/i;
175 if ($k =~ /\ATransfer-Encoding\z/i && $v =~ /\bchunked\b/i) {
181 my $conn = $env->{HTTP_CONNECTION} || '';
182 my $term = defined($len) || $chunked;
183 my $prot_persist = ($proto eq 'HTTP/1.1') && ($conn !~ /\bclose\b/i);
185 if (!$term && $prot_persist) { # auto-chunk
186 $chunked = $alive = 2;
187 $h .= "Transfer-Encoding: chunked\r\n";
188 # no need for "Connection: keep-alive" with HTTP/1.1
189 } elsif ($term && ($prot_persist || ($conn =~ /\bkeep-alive\b/i))) {
191 $h .= "Connection: keep-alive\r\n";
194 $h .= "Connection: close\r\n";
196 $h .= 'Date: ' . http_date() . "\r\n\r\n";
198 if (($len || $chunked) && $env->{REQUEST_METHOD} ne 'HEAD') {
206 # middlewares such as Deflater may write empty strings
207 sub chunked_write ($$) {
209 return if $_[1] eq '';
210 msg_more($self, sprintf("%x\r\n", length($_[1])));
211 msg_more($self, $_[1]);
213 # use $self->write(\"\n\n") if you care about real-time
214 # streaming responses, public-inbox WWW does not.
215 msg_more($self, "\r\n");
218 sub identity_write ($$) {
220 $self->write(\($_[1])) if $_[1] ne '';
224 my ($self, $alive) = @_;
225 delete $self->{env}; # we're no longer busy
226 $self->write(\"0\r\n\r\n") if $alive == 2;
227 $self->write($alive ? $self->can('requeue') : \&close);
232 my $forward = $self->{forward};
234 # limit our own running time for fairness with other
235 # clients and to avoid buffering too much:
242 # may close in PublicInbox::DS::write
243 if ($self->{alive} == 2) {
244 chunked_write($self, $buf);
246 identity_write($self, $buf);
251 my $new_size = push(@{$self->{wbuf}}, \&getline_pull);
253 # wbuf may be populated by {chunked,identity}_write()
254 # above, no need to rearm if so:
255 $self->requeue if $new_size == 1;
259 warn "response ->getline error: $@";
263 if (delete $self->{forward}) {
264 eval { $forward->close };
266 warn "response ->close error: $@";
267 $self->close; # idempotent
270 response_done($self, delete $self->{alive});
274 my ($self, $env, $res) = @_;
275 my $alive = response_header_write($self, $env, $res);
276 if (defined(my $body = $res->[2])) {
277 if (ref $body eq 'ARRAY') {
279 chunked_write($self, $_) for @$body;
281 identity_write($self, $_) for @$body;
283 response_done($self, $alive);
285 $self->{forward} = $body;
286 $self->{alive} = $alive;
287 getline_pull($self); # kick-off!
289 # these are returned to the calling application:
290 } elsif ($alive == 2) {
291 bless [ $self, $alive ], 'PublicInbox::HTTP::Chunked';
293 bless [ $self, $alive ], 'PublicInbox::HTTP::Identity';
298 my ($self, $env) = @_;
301 # rfc 7230 3.3.2, 3.3.3,: favor Transfer-Encoding over Content-Length
302 my $hte = $env->{HTTP_TRANSFER_ENCODING};
304 # rfc7230 3.3.3, point 3 says only chunked is accepted
305 # as the final encoding. Since neither public-inbox-httpd,
306 # git-http-backend, or our WWW-related code uses "gzip",
307 # "deflate" or "compress" as the Transfer-Encoding, we'll
309 return quit($self, 400) if $hte !~ /\Achunked\z/i;
312 $input = tmpfile('http.input', $self->{sock});
314 $len = $env->{CONTENT_LENGTH};
317 return quit($self, 400) if $len !~ /\A[0-9]+\z/;
318 return quit($self, 413) if $len > $MAX_REQUEST_BUFFER;
319 $input = $len ? tmpfile('http.input', $self->{sock})
326 # TODO: expire idle clients on ENFILE / EMFILE
327 $env->{'psgi.input'} = $input // return;
329 $self->{input_left} = $len || 0;
332 sub env_chunked { ($_[0]->{HTTP_TRANSFER_ENCODING} // '') =~ /\Achunked\z/i }
335 my ($self, $len) = @_;
336 my $msg = $! || '(zero write)';
337 $msg .= " ($len bytes remaining)" if defined $len;
338 warn "error buffering to input: $msg";
343 my ($self, $len) = @_;
344 if ($! == EAGAIN) { # epoll/kevent watch already set by do_read
345 $self->{input_left} = $len;
347 warn "error reading input: $! ($len bytes remaining)";
351 sub read_input_chunked { # unlikely...
352 my ($self, $rbuf) = @_;
353 $rbuf //= $self->{rbuf} // (\(my $x = ''));
354 my $input = $self->{env}->{'psgi.input'};
355 my $len = delete $self->{input_left};
357 while (1) { # chunk start
358 if ($len == CHUNK_ZEND) {
359 $$rbuf =~ s/\A\r\n//s and
360 return app_dispatch($self, $input, $rbuf);
362 return quit($self, 400) if length($$rbuf) > 2;
364 if ($len == CHUNK_END) {
365 if ($$rbuf =~ s/\A\r\n//s) {
367 } elsif (length($$rbuf) > 2) {
368 return quit($self, 400);
371 if ($len == CHUNK_START) {
372 if ($$rbuf =~ s/\A([a-f0-9]+).*?\r\n//i) {
374 if (($len + -s $input) > $MAX_REQUEST_BUFFER) {
375 return quit($self, 413);
377 } elsif (length($$rbuf) > CHUNK_MAX_HDR) {
378 return quit($self, 400);
380 # will break from loop since $len >= 0
383 if ($len < 0) { # chunk header is trickled, read more
384 $self->do_read($rbuf, 8192, length($$rbuf)) or
385 return recv_err($self, $len);
386 # (implicit) goto chunk_start if $r > 0;
388 $len = CHUNK_ZEND if $len == 0;
390 # drain the current chunk
393 my $w = syswrite($input, $$rbuf, $len);
394 return write_err($self, "$len chunk") if !$w;
397 # we may have leftover data to parse
399 $$rbuf = substr($$rbuf, $w);
402 die "BUG: len < 0: $len";
408 # read more of current chunk
409 $self->do_read($rbuf, 8192) or
410 return recv_err($self, $len);
417 my ($self, $status) = @_;
418 my $h = "HTTP/1.1 $status " . status_message($status) . "\r\n\r\n";
421 undef; # input_prepare expects this
426 if (my $forward = delete $self->{forward}) {
427 eval { $forward->close };
428 warn "forward ->close error: $@" if $@;
430 $self->SUPER::close; # PublicInbox::DS::close
433 sub busy { # for graceful shutdown in PublicInbox::Daemon:
435 defined($self->{rbuf}) || exists($self->{env}) || defined($self->{wbuf})
438 # runs $cb on the next iteration of the event loop at earliest
440 my ($self, $cb) = @_;
441 return unless exists $self->{sock};
442 $self->requeue if 1 == push(@{$self->{wbuf}}, $cb);
445 # Chunked and Identity packages are used for writing responses.
446 # They may be exposed to the PSGI application when the PSGI app
447 # returns a CODE ref for "push"-based responses
448 package PublicInbox::HTTP::Chunked;
452 # ([$http], $buf) = @_;
453 PublicInbox::HTTP::chunked_write($_[0]->[0], $_[1])
457 # $_[0] = [$http, $alive]
458 PublicInbox::HTTP::response_done(@{$_[0]});
461 package PublicInbox::HTTP::Identity;
463 our @ISA = qw(PublicInbox::HTTP::Chunked);
466 # ([$http], $buf) = @_;
467 PublicInbox::HTTP::identity_write($_[0]->[0], $_[1]);