# Copyright (C) 2016 all contributors # License: AGPL-3.0+ # 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 PublicInbox::Spawn qw(spawn); # 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}; 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 $r = sysread($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? $cgi->{env}->{'psgix.no-compress'} = 1; } } ($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'}; my $fd = eval { fileno($input) }; if (defined $fd && $fd >= 0) { $in = $input; } else { $in = input_to_file($env) or return r(500); } my ($rpipe, $wpipe); unless (pipe($rpipe, $wpipe)) { $err->print("error creating pipe: $!\n"); return r(500); } my %env = %ENV; # 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; } my $git_dir = $git->{git_dir}; $env{GIT_HTTP_EXPORT_ALL} = '1'; $env{PATH_TRANSLATED} = "$git_dir/$path"; my %rdr = ( 0 => fileno($in), 1 => fileno($wpipe) ); my $pid = spawn([qw(git http-backend)], \%env, \%rdr); unless (defined $pid) { $err->print("error spawning: $!\n"); return r(500); } $wpipe = $in = undef; $buf = ''; my ($vin, $fh, $res); my $end = sub { if ($fh) { $fh->close; $fh = undef; } else { $res->(r(500)) if $res; } if ($rpipe) { $rpipe->close; # _may_ be Danga::Socket::close $rpipe = undef; } if (defined $pid) { my $wpid = $pid; $pid = undef; return if $wpid == waitpid($wpid, 0); $err->print("git http-backend ($git_dir): $?\n"); } }; my $fail = sub { my ($e) = @_; if ($e eq 'EAGAIN') { select($vin, undef, undef, undef) if defined $vin; # $vin is undef on async, so this is a noop on EAGAIN return; } $end->(); $err->print("git http-backend ($git_dir): $e\n"); }; my $cb = sub { # read git-http-backend output and stream to client my $r = $rpipe ? $rpipe->sysread($buf, 8192, length($buf)) : 0; return $fail->($!{EAGAIN} ? 'EAGAIN' : $!) unless defined $r; return $end->() if $r == 0; # EOF if ($fh) { # stream body from git-http-backend to HTTP client $fh->write($buf); $buf = ''; } elsif ($buf =~ s/\A(.*?)\r\n\r\n//s) { # parse headers my $h = $1; my $code = 200; my @h; foreach my $l (split(/\r\n/, $h)) { my ($k, $v) = split(/:\s*/, $l, 2); if ($k =~ /\AStatus\z/i) { ($code) = ($v =~ /\b(\d+)\b/); } else { push @h, $k, $v; } } # write response header: $fh = $res->([ $code, \@h ]); $res = undef; $fh->write($buf); $buf = ''; } # else { keep reading ... } }; if (my $async = $env->{'pi-httpd.async'}) { $rpipe = $async->($rpipe, $cb); sub { ($res) = @_ } # let Danga::Socket handle the rest. } else { # synchronous loop for other PSGI servers $vin = ''; vec($vin, fileno($rpipe), 1) = 1; sub { ($res) = @_; while ($rpipe) { $cb->() } } } } sub input_to_file { my ($env) = @_; my $in = IO::File->new_tmpfile; my $input = $env->{'psgi.input'}; my $buf; while (1) { my $r = $input->read($buf, 8192); unless (defined $r) { my $err = $env->{'psgi.errors'}; $err->print("error reading input: $!\n"); return; } last if ($r == 0); $in->write($buf); } $in->flush; $in->sysseek(0, SEEK_SET); return $in; } 1;