diff options
Diffstat (limited to 'lib/PublicInbox/GitHTTPBackend.pm')
| -rw-r--r-- | lib/PublicInbox/GitHTTPBackend.pm | 214 |
1 files changed, 214 insertions, 0 deletions
diff --git a/lib/PublicInbox/GitHTTPBackend.pm b/lib/PublicInbox/GitHTTPBackend.pm new file mode 100644 index 00000000..71b7a8f1 --- /dev/null +++ b/lib/PublicInbox/GitHTTPBackend.pm @@ -0,0 +1,214 @@ +# Copyright (C) 2016 all contributors <meta@public-inbox.org> +# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt> + +# when no endpoints match, fallback to this and serve a static file +# or smart HTTP +package PublicInbox::GitHTTPBackend; +use strict; +use warnings; +use Fcntl qw(:seek); +use POSIX qw(dup2); + +# n.b. serving "description" and "cloneurl" should be innocuous enough to +# not cause problems. serving "config" might... +my @text = qw[HEAD info/refs + objects/info/(?:http-alternates|alternates|packs) + cloneurl description]; + +my @binary = qw! + objects/[a-f0-9]{2}/[a-f0-9]{38} + objects/pack/pack-[a-f0-9]{40}\.(?:pack|idx) + !; + +our $ANY = join('|', @binary, @text); +my $BIN = join('|', @binary); +my $TEXT = join('|', @text); + +sub r { + [ $_[0] , [qw(Content-Type text/plain Content-Length 0) ], [] ] +} + +sub serve { + my ($cgi, $git, $path) = @_; + my $service = $cgi->param('service') || ''; + if ($service =~ /\Agit-\w+-pack\z/ || $path =~ /\Agit-\w+-pack\z/) { + my $ok = serve_smart($cgi, $git, $path); + return $ok if $ok; + } + + my $type; + if ($path =~ /\A(?:$BIN)\z/o) { + $type = 'application/octet-stream'; + } elsif ($path =~ /\A(?:$TEXT)\z/o) { + $type = 'text/plain'; + } else { + return r(404); + } + my $f = "$git->{git_dir}/$path"; + return r(404) unless -f $f && -r _; + my @st = stat(_); + my $size = $st[7]; + + # TODO: If-Modified-Since and Last-Modified + open my $in, '<', $f or return r(404); + my $code = 200; + my $len = $size; + my @h; + + my $env = $cgi->{env} || \%ENV; + my $range = $env->{HTTP_RANGE}; + if (defined $range && $range =~ /\bbytes=(\d*)-(\d*)\z/) { + ($code, $len) = prepare_range($cgi, $in, \@h, $1, $2, $size); + if ($code == 416) { + push @h, 'Content-Range', "bytes */$size"; + return [ 416, \@h, [] ]; + } + } + + push @h, 'Content-Type', $type, 'Content-Length', $len; + sub { + my ($res) = @_; # Plack callback + my $fh = $res->([ $code, \@h ]); + my $buf; + my $n = 8192; + while ($len > 0) { + $n = $len if $len < $n; + my $r = read($in, $buf, $n); + last if (!defined($r) || $r <= 0); + $len -= $r; + $fh->write($buf); + } + $fh->close; + } +} + +sub prepare_range { + my ($cgi, $in, $h, $beg, $end, $size) = @_; + my $code = 200; + my $len = $size; + if ($beg eq '') { + if ($end ne '') { # "bytes=-$end" => last N bytes + $beg = $size - $end; + $beg = 0 if $beg < 0; + $end = $size - 1; + $code = 206; + } else { + $code = 416; + } + } else { + if ($beg > $size) { + $code = 416; + } elsif ($end eq '' || $end >= $size) { + $end = $size - 1; + $code = 206; + } elsif ($end < $size) { + $code = 206; + } else { + $code = 416; + } + } + if ($code == 206) { + $len = $end - $beg + 1; + if ($len <= 0) { + $code = 416; + } else { + seek($in, $beg, SEEK_SET) or return [ 500, [], [] ]; + push @$h, qw(Accept-Ranges bytes Content-Range); + push @$h, "bytes $beg-$end/$size"; + + # FIXME: Plack::Middleware::Deflater bug? + if (my $env = $cgi->{env}) { + $env->{'psgix.no-compress'} = 1; + } + } + } + ($code, $len); +} + +# returns undef if 403 so it falls back to dumb HTTP +sub serve_smart { + my ($cgi, $git, $path) = @_; + my $env = $cgi->{env}; + + my $input = $env->{'psgi.input'}; + my $buf; + my $in; + my $err = $env->{'psgi.errors'}; + if (fileno($input) >= 0) { # FIXME untested + $in = $input; + } else { + $in = IO::File->new_tmpfile; + while (1) { + my $r = $input->read($buf, 8192); + unless (defined $r) { + $err->print('error reading input: ', $!, "\n"); + return r(500); + } + last if ($r == 0); + $in->write($buf); + } + $in->flush; + $in->sysseek(0, SEEK_SET); + } + my $out = IO::File->new_tmpfile; + my $pid = fork; # TODO: vfork under Linux... + unless (defined $pid) { + $err->print('error forking: ', $!, "\n"); + return r(500); + } + if ($pid == 0) { + # GIT_HTTP_EXPORT_ALL, GIT_COMMITTER_NAME, GIT_COMMITTER_EMAIL + # may be set in the server-process and are passed as-is + foreach my $name (qw(QUERY_STRING + REMOTE_USER REMOTE_ADDR + HTTP_CONTENT_ENCODING + CONTENT_TYPE + SERVER_PROTOCOL + REQUEST_METHOD)) { + my $val = $env->{$name}; + $ENV{$name} = $val if defined $val; + } + # $ENV{GIT_PROJECT_ROOT} = $git->{git_dir}; + $ENV{GIT_HTTP_EXPORT_ALL} = '1'; + $ENV{PATH_TRANSLATED} = "$git->{git_dir}/$path"; + dup2(fileno($in), 0) or die "redirect stdin failed: $!\n"; + dup2(fileno($out), 1) or die "redirect stdout failed: $!\n"; + my @cmd = qw(git http-backend); + exec(@cmd) or die 'exec `' . join(' ', @cmd). "' failed: $!\n"; + } + + if (waitpid($pid, 0) != $pid) { + $err->print("git http-backend ($git->{git_dir}): ", $?, "\n"); + return r(500); + } + $in = undef; + $out->seek(0, SEEK_SET); + my @h; + my $code = 200; + { + local $/ = "\r\n"; + while (defined(my $line = <$out>)) { + if ($line =~ /\AStatus:\s*(\d+)/) { + $code = $1; + } else { + chomp $line; + last if $line eq ''; + push @h, split(/:\s*/, $line, 2); + } + } + } + return if $code == 403; + sub { + my ($cb) = @_; + my $fh = $cb->([ $code, \@h ]); + while (1) { + my $r = $out->read($buf, 8192); + die "$!\n" unless defined $r; + last if ($r == 0); + $fh->write($buf); + } + $fh->close; + } +} + +1; |