1 files changed, 60 insertions, 35 deletions

diff --git a/git-daemon/git-daemon.pl b/git-daemon/git-daemon.pl
index f18f6b9..df753e1 100644..100755
--- a/git-daemon/git-daemon.pl
+++ b/git-daemon/git-daemon.pl
@@ -1,10 +1,10 @@
 #!/usr/bin/perl
 #
-# A very simple userv git-daemon wrapper.
+# A git daemon with an added userv security boundary.
 #
 # This reads the first packet-line of the protocol, checks the syntax
-# of the user, pathname, and hostname, then uses userv to invoke the
-# real git daemon as the target user with safe arguments.
+# of the pathname and hostname, then uses userv to invoke the
+# git-upload-pack as the target user with safe arguments.
 #
 # This was written by Tony Finch <dot@dotat.at>
 # You may do anything with it, at your own risk.
@@ -14,49 +14,74 @@ use strict;
 use warnings;
 
 use POSIX;
+use Socket;
+use Sys::Syslog;
 
-my $USER = qr{[0-9a-z]+};
-my $PATH = qr{[-+,._/0-9A-Za-z]+};
-my $HOST = qr{[-.0-9A-Za-z]+};
+use vars qw{ %vhost_default_user %vhost_user_from_tilde
+	     $TILDE $REPO $HOSTNAME };
+
+use lib '/etc/userv';
+require 'git-daemon-vhosts.pl';
+
+my $peer = getpeername STDIN;
+my ($port,$addr);
+if (defined $peer) {
+    ($port,$addr) = sockaddr_in $peer;
+    $addr = inet_ntoa $addr;
+    $peer = "[$addr]:$port";
+} else {
+    $peer = "[?.?.?.?]:?";
+    undef $!;
+}
+
+openlog 'userv-git-daemon', 'pid', 'daemon';
+
+sub fail {
+    syslog 'err', "$peer @_";
+    exit;
+}
 
 sub xread {
     my $length = shift;
     my $buffer = "";
     my $count = 0;
+    # simply die if the client takes too long
+    alarm 30;
     while ($length > length $buffer) {
-	my $data;
-	my $ret = sysread STDIN, $data, $len
-	  while not defined $ret and ($! == EINTR or $! == EAGAIN);
-	die "read" unless defined $ret;
-	die "short read: expected $length bytes, got $count\n" if $ret == 0;
-	$buffer .= $data;
-	$count += $ret;
+        my ($data,$ret);
+	do {
+	    $ret = sysread STDIN, $data, $length
+	} while not defined $ret and ($! == EINTR or $! == EAGAIN);
+        fail "read: $!" unless defined $ret;
+        fail "short read: expected $length bytes, got $count" if $ret == 0;
+        $buffer .= $data;
+        $count += $ret;
     }
+    alarm 0;
     return $buffer;
 }
 
 my $len_hex = xread 4;
-die "bad packet length" unless $len_hex =~ m{^[0-9a-zA-Z]{4}$};
-my $len = hex $len;
+fail "non-hexadecimal packet length" unless $len_hex =~ m{^[0-9a-zA-Z]{4}$};
+my $len = hex $len_hex;
 
 my $line = xread $len;
-$line =~ m{^git-upload-pack ~($USER)/($PATH[.]git)\0host=($HOST)\0$};
-my ($user,$path,$host) = ($1,$2,$3);
-
-# child's output will go directly to inetd
-open CHILD, '-|', 'userv', $user,
-  qw(git daemon --inetd --strict-paths
-     --user-path=public-git --forbid-override=receive-pack)
-  or die "open pipe to userv: $!\n";
-
-# proxy command line to child
-syswrite CHILD, $len_hex.$line
-  or die "write to userv: $!\n";
-
-# relay stdin to child
-open STDOUT, ">&CHILD"
-  or die "dup: $!\n";
-exec 'cat'
-  or die "exec: $!\n";
-
-die
+unless ($line =~ m{^git-upload-pack (?:~($TILDE)/)?($REPO[.]git)\0host=($HOSTNAME)\0$}) {
+    $line =~ s/[^ -~]+/ /g;
+    fail "could not parse \"$line\""
+}
+my ($tilde,$repo,$host) = ($1,$2,$3);
+my $url = $tilde ? "git://$host/~$tilde/$repo" : "git://$host/$repo";
+
+my $user = $vhost_user_from_tilde{$host} ? $tilde : $vhost_default_user{$host};
+fail "no user configuration for $url" unless defined $user;
+
+syslog 'info', "$peer $user $url";
+
+my @opts = ("-DCLIENT=$addr", "-DHOST=$host", "-DREPO=$repo");
+push @opts, "-DTILDE=$tilde" if defined $tilde;
+
+exec 'userv', @opts, $user, 'git-upload-pack'
+    or fail "exec userv: $!";
+
+# end