public-inbox.git  about / heads / tags
an "archives first" approach to mailing lists
blob fd2e00ddbdc98cf54deb6238238ef597b21c4de1 4648 bytes (raw)
$ git show v1.4.0:lib/PublicInbox/GitHTTPBackend.pm	# shows this blob on the CLI

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
 
# Copyright (C) 2016-2020 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.  This is our wrapper for git-http-backend(1)
package PublicInbox::GitHTTPBackend;
use strict;
use warnings;
use Fcntl qw(:seek);
use IO::Handle; # ->flush
use HTTP::Date qw(time2str);
use PublicInbox::Qspawn;
use PublicInbox::Tmpfile;
use PublicInbox::WwwStatic qw(r @NO_CACHE);

# 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);

sub serve {
	my ($env, $git, $path) = @_;

	# Documentation/technical/http-protocol.txt in git.git
	# requires one and exactly one query parameter:
	if ($env->{QUERY_STRING} =~ /\Aservice=git-[A-Za-z0-9_]+-pack\z/ ||
				$path =~ /\Agit-[A-Za-z0-9_]+-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");
}

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 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);
	}
	$path = "$git->{git_dir}/$path";
	PublicInbox::WwwStatic::response($env, $h, $path, $type);
}

sub git_parse_hdr { # {parse_hdr} for Qspawn
	my ($r, $bref, $dumb_args) = @_;
	my $res = parse_cgi_headers($r, $bref) or return; # incomplete
	$res->[0] == 403 ? serve_dumb(@$dumb_args) : $res;
}

# 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, $limiter, \&git_parse_hdr, [$env, $git, $path]);
}

sub input_prepare {
	my ($env) = @_;

	my $input = $env->{'psgi.input'};
	my $fd = eval { fileno($input) };
	if (defined $fd && $fd >= 0) {
		return { 0 => $fd };
	}
	my $id = "git-http.input.$env->{REMOTE_ADDR}:$env->{REMOTE_PORT}";
	my $in = tmpfile($id);
	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;
		unless (print $in $buf) {
			err($env, "error writing temporary file: $!");
			return;
		}
	}
	# ensure it's visible to git-http-backend(1):
	unless ($in->flush) {
		err($env, "error writing temporary file: $!");
		return;
	}
	unless (defined(sysseek($in, 0, SEEK_SET))) {
		err($env, "error seeking temporary file: $!");
		return;
	}
	{ 0 => $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([0-9]+)\b/);
		} else {
			push @h, $k, $v;
		}
	}
	[ $code, \@h ]
}

1;

git clone https://public-inbox.org/public-inbox.git
git clone http://7fh6tueqddpjyxjmgtdiueylzoqt6pt7hec3pukyptlmohoowvhde4yd.onion/public-inbox.git