support smart HTTP cloning

[public-inbox.git] / lib / PublicInbox / GitHTTPBackend.pm

diff --git a/lib/PublicInbox/GitHTTPDumb.pm b/lib/PublicInbox/GitHTTPBackend.pm
similarity index 53%
rename from lib/PublicInbox/GitHTTPDumb.pm
rename to lib/PublicInbox/GitHTTPBackend.pm
index c088d8c4980ebf11cd0fe4188e79a1afcae60409..71b7a8f1b1c12278730dd8c8cd64cf6f3a93d415 100644 (file)
--- a/lib/PublicInbox/GitHTTPDumb.pm
+++ b/lib/PublicInbox/GitHTTPBackend.pm
@@ -2,11 +2,12 @@
 # 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
-# This can serve Smart HTTP in the future.
-package PublicInbox::GitHTTPDumb;
+# 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...
@@ -29,6 +30,12 @@ sub r {
 
 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) {
                $type = 'application/octet-stream';
@@ -118,4 +125,90 @@ sub prepare_range {
        ($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;