Run user programs as nobody:nogroup

[gruntmaster-daemon.git] / gruntmaster-exec

diff --git a/gruntmaster-exec b/gruntmaster-exec
index 49e915a8d5cf131075170b7fcb6539ac1a3a4bd4..e7d7363d4c44308c0622a32e4ecbb7565682c88c 100755 (executable)
--- a/gruntmaster-exec
+++ b/gruntmaster-exec
@@ -18,6 +18,9 @@ use constant +{
        DIED => 5,
        REJ => 10,
 };
+# These constants are changed by ex/makevm
+use constant USER => 65534;
+use constant GROUP => 65534;
 
 use BSD::Resource qw/setrlimit RLIMIT_AS RLIMIT_FSIZE/;
 use IPC::Signal qw/sig_name sig_num/;
@@ -27,12 +30,16 @@ use Getopt::Long;
 use POSIX qw//;
 use Time::HiRes qw/alarm/;
 
-my (@fds, $timeout, $mlimit, $olimit);
+my (@fds, $timeout, $mlimit, $olimit, $nobody);
+my $close = 1;
+
 GetOptions(
        "fd=s"      => \@fds,
        "timeout=f" => \$timeout,
        "mlimit=i"  => \$mlimit,
        "olimit=i"  => \$olimit,
+       "close!"    => \$close,
+       "nobody!"   => \$nobody,
 );
 
 my $ret = fork // die 'Cannot fork';
@@ -51,7 +58,9 @@ if ($ret) {
        exit !say AC,   "\nAll OK";
 } else {
        $^F = 50;
-       POSIX::close $_ for 0 .. $^F;
+       if ($close) {
+               POSIX::close $_ for 0 .. $^F;
+       }
        for my $fdstring (@fds) {
                my ($fd, $file) = split ' ', $fdstring, 2;
                open my $fh, $file or die $!;
@@ -64,6 +73,8 @@ if ($ret) {
        %ENV = (ONLINE_JUDGE => 1, PATH => $ENV{PATH}, HOME => $ENV{HOME});
        setrlimit RLIMIT_AS, $mlimit, $mlimit or die $! if $mlimit;
        setrlimit RLIMIT_FSIZE, $olimit, $olimit or die $! if $olimit;
+       POSIX::setgid $nobody ? 65534 : USER;
+       POSIX::setuid $nobody ? 65534 : GROUP;
        exec @ARGV;
 }