# Copyright (C) 2016-2018 all contributors # License: AGPL-3.0+ # when no endpoints match, fallback to this and serve a static file # or smart HTTP. This is our wrapper for git-http-backend(1) package PublicInbox::GitHTTPBackend; use strict; use warnings; use Fcntl qw(:seek); use IO::Handle; use HTTP::Date qw(time2str); use HTTP::Status qw(status_message); use Plack::Util; use PublicInbox::Qspawn; # 32 is same as the git-daemon connection limit my $default_limiter = PublicInbox::Qspawn::Limiter->new(32); # n.b. serving "description" and "cloneurl" should be innocuous enough to # not cause problems. serving "config" might... my @text = qw[HEAD info/refs info/attributes 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, 'git-upload-pack'); my $BIN = join('|', @binary); my $TEXT = join('|', @text); my @no_cache = ('Expires', 'Fri, 01 Jan 1980 00:00:00 GMT', 'Pragma', 'no-cache', 'Cache-Control', 'no-cache, max-age=0, must-revalidate'); sub r ($;$) { my ($code, $msg) = @_; $msg ||= status_message($code); my $len = length($msg); [ $code, [qw(Content-Type text/plain Content-Length), $len, @no_cache], [$msg] ] } sub serve { my ($env, $git, $path) = @_; # XXX compatibility... ugh, can we stop supporting this? $git = PublicInbox::Git->new($git) unless ref($git); # Documentation/technical/http-protocol.txt in git.git # requires one and exactly one query parameter: if ($env->{QUERY_STRING} =~ /\Aservice=git-\w+-pack\z/ || $path =~ /\Agit-\w+-pack\z/) { my $ok = serve_smart($env, $git, $path); return $ok if $ok; } serve_dumb($env, $git, $path); } sub err ($@) { my ($env, @msg) = @_; $env->{'psgi.errors'}->print(@msg, "\n"); } sub drop_client ($) { if (my $io = $_[0]->{'psgix.io'}) { $io->close; # this is Danga::Socket::close } } my $prev = 0; my $exp; sub cache_one_year { my ($h) = @_; my $t = time + 31536000; push @$h, 'Expires', $t == $prev ? $exp : ($exp = time2str($prev = $t)), 'Cache-Control', 'public, max-age=31536000'; } sub static_result ($$$$) { my ($env, $h, $f, $type) = @_; return r(404) unless -f $f && -r _; # just in case it's a FIFO :P # TODO: If-Modified-Since and Last-Modified? open my $in, '<', $f or return r(404); my $size = -s $in; my $len = $size; my $code = 200; push @$h, 'Content-Type', $type; if (($env->{HTTP_RANGE} || '') =~ /\bbytes=(\d*)-(\d*)\z/) { ($code, $len) = prepare_range($env, $in, $h, $1, $2, $size); if ($code == 416) { push @$h, 'Content-Range', "bytes */$size"; return [ 416, $h, [] ]; } } push @$h, 'Content-Length', $len; my $n = 65536; [ $code, $h, Plack::Util::inline_object(close => sub { close $in }, getline => sub { return if $len == 0; $n = $len if $len < $n; my $r = sysread($in, my $buf, $n); if (!defined $r) { err($env, "$f read error: $!"); } elsif ($r <= 0) { err($env, "$f EOF with $len bytes left"); } else { $len -= $r; $n = 8192; return $buf; } drop_client($env); return; })] } sub serve_dumb { my ($env, $git, $path) = @_; my $h = []; my $type; if ($path =~ m!\Aobjects/[a-f0-9]{2}/[a-f0-9]{38}\z!) { $type = 'application/x-git-loose-object'; cache_one_year($h); } elsif ($path =~ m!\Aobjects/pack/pack-[a-f0-9]{40}\.pack\z!) { $type = 'application/x-git-packed-objects'; cache_one_year($h); } elsif ($path =~ m!\Aobjects/pack/pack-[a-f0-9]{40}\.idx\z!) { $type = 'application/x-git-packed-objects-toc'; cache_one_year($h); } elsif ($path =~ /\A(?:$TEXT)\z/o) { $type = 'text/plain'; push @$h, @no_cache; } else { return r(404); } static_result($env, $h, "$git->{git_dir}/$path", $type); } sub prepare_range { my ($env, $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 { sysseek($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? $env->{'psgix.no-compress'} = 1; } } ($code, $len); } # returns undef if 403 so it falls back to dumb HTTP sub serve_smart { my ($env, $git, $path) = @_; my %env = %ENV; # 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 $limiter = $git->{-httpbackend_limiter} || $default_limiter; $env{GIT_HTTP_EXPORT_ALL} = '1'; $env{PATH_TRANSLATED} = "$git->{git_dir}/$path"; my $rdr = input_prepare($env) or return r(500); my $qsp = PublicInbox::Qspawn->new([qw(git http-backend)], \%env, $rdr); $qsp->psgi_return($env, $limiter, sub { my ($r, $bref) = @_; my $res = parse_cgi_headers($r, $bref) or return; # incomplete $res->[0] == 403 ? serve_dumb($env, $git, $path) : $res; }); } sub input_prepare { my ($env) = @_; my $input = $env->{'psgi.input'}; my $fd = eval { fileno($input) }; if (defined $fd && $fd >= 0) { return { 0 => $fd }; } open(my $in, '+>', undef); unless (defined $in) { err($env, "could not open temporary file: $!"); return; } my $buf; while (1) { my $r = $input->read($buf, 8192); unless (defined $r) { err($env, "error reading input: $!"); return; } last if $r == 0; my $off = 0; while ($r > 0) { my $w = syswrite($in, $buf, $r, $off); if (defined $w) { $r -= $w; $off += $w; } else { err($env, "error writing temporary file: $!"); return; } } } unless (defined(sysseek($in, 0, SEEK_SET))) { err($env, "error seeking temporary file: $!"); return; } { 0 => fileno($in), -hold => $in }; } sub parse_cgi_headers { my ($r, $bref) = @_; return r(500) unless defined $r && $r >= 0; $$bref =~ s/\A(.*?)\r?\n\r?\n//s or return $r == 0 ? r(500) : undef; 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; } } [ $code, \@h ] } 1;