Bug #83910 for Nmap-Scanner: Bug handling large outputs from nmap

Since the module as written blocks on reading stderr from namp, namp's stdout output buffer can fill and block causing things to hang. Included patch updates the code to use select loop on the output to prevent this from happening and to allow reading of large amounts of data from nmap. diff -ru scan_rpc-0.005-BACKUP/lib/Nmap/Scanner/Backend/XML.pm scan_rpc-0.005/lib/Nmap/Scanner/Backend/XML.pm --- scan_rpc-0.005-BACKUP/lib/Nmap/Scanner/Backend/XML.pm 2013-03-12 13:49:02.100461965 -0700 +++ scan_rpc-0.005/lib/Nmap/Scanner/Backend/XML.pm 2013-03-12 14:41:51.155406282 -0700 @@ -30,11 +30,39 @@ my $cmdline = shift; my $error = shift; + my $readbuf = ""; + my $errorbuf = ""; + # Suppress warnings about reading unopened handle $^W = 0; - my $err = join('', (<$error>)); + + my $fd_set = new IO::Select(); + $fd_set->add($read); + $fd_set->add($error); + + while (1) { + my ($rh_set) = IO::Select->select($fd_set, undef, undef, 10); + + for my $fd (@$rh_set) { + my $tbuf = ""; + if ($fd == $read) { + my $retval = sysread($read, $tbuf, 1024); + $readbuf .= $tbuf; + goto DONE if (!defined($retval) || $retval == 0); + } + if ($fd == $error) { + my $retval = sysread($error, $tbuf, 1024); + $errorbuf .= $tbuf; + goto DONE if (!defined($retval) || $retval == 0); + } + } + } + DONE: + $^W = 1; + my $err = $errorbuf; + if ($err ne '') { close($read); @@ -53,15 +81,12 @@ my $handler = NmapHandler->new($self); my $parser = XML::SAX::ParserFactory->parser(Handler => $handler); - eval { $parser->parse_file($read) }; + eval { $parser->parse_string($readbuf) }; if (defined($@) && ($@ ne '')) { - my $msg = join('', <$read>); - - Nmap::Scanner::debug("bytes in input stream: " . tell($read)); - Nmap::Scanner::debug("bytes in error stream: " . tell($error)); + my $msg = $readbuf; warn <<EOF; <nmap-error> -- Kelsey Cummings - kgc@corp.sonic.net sonic.net, inc. System Architect 2260 Apollo Way 707.522.1000 Santa Rosa, CA 95407