4 * Some functions to help implement an external link filter for spam control.
6 * TODO: implement the filter. Currently these are just some functions to help
7 * maintenance/cleanupSpam.php remove links to a single specified domain. The
8 * next thing is to implement functions for checking a given page against a big
11 * Another cool thing to do would be a web interface for fast spam removal.
17 static function matchEntry( $text, $filterEntry ) {
18 $regex = LinkFilter::makeRegex( $filterEntry );
19 return preg_match( $regex, $text );
25 private static function makeRegex( $filterEntry ) {
27 if ( substr( $filterEntry, 0, 2 ) == '*.' ) {
28 $regex .= '(?:[A-Za-z0-9.-]+\.|)';
29 $filterEntry = substr( $filterEntry, 2 );
31 $regex .= preg_quote( $filterEntry, '!' ) . '!Si';
36 * Make a string to go after an SQL LIKE, which will match the specified
37 * string. There are several kinds of filter entry:
38 * *.domain.com - Produces http://com.domain.%, matches domain.com
40 * domain.com - Produces http://com.domain./%, matches domain.com
41 * or domain.com/ but not www.domain.com
42 * *.domain.com/x - Produces http://com.domain.%/x%, matches
44 * domain.com/x - Produces http://com.domain./x%, matches
45 * domain.com/xy but not www.domain.com/xy
47 * Asterisks in any other location are considered invalid.
50 * @param $filterEntry String: domainparts
51 * @param $prot String: protocol
53 public static function makeLike( $filterEntry , $prot = 'http://' ) {
54 if ( substr( $filterEntry, 0, 2 ) == '*.' ) {
56 $filterEntry = substr( $filterEntry, 2 );
57 if ( $filterEntry == '' ) {
58 // We don't want to make a clause that will match everything,
59 // that could be dangerous
65 // No stray asterisks, that could cause confusion
66 // It's not simple or efficient to handle it properly so we don't
68 if ( strpos( $filterEntry, '*' ) !== false ) {
71 $slash = strpos( $filterEntry, '/' );
72 if ( $slash !== false ) {
73 $path = substr( $filterEntry, $slash );
74 $host = substr( $filterEntry, 0, $slash );
79 // Reverse the labels in the hostname, convert to lower case
80 // For emails reverse domainpart only
81 if ( $prot == 'mailto:' && strpos($host, '@') ) {
82 // complete email adress
83 $mailparts = explode( '@', $host );
84 $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
85 $host = $domainpart . '@' . $mailparts[0];
86 $like = "$prot$host%";
87 } elseif ( $prot == 'mailto:' ) {
88 // domainpart of email adress only. do not add '.'
89 $host = strtolower( implode( '.', array_reverse( explode( '.', $host ) ) ) );
90 $like = "$prot$host%";
92 $host = strtolower( implode( '.', array_reverse( explode( '.', $host ) ) ) );
93 if ( substr( $host, -1, 1 ) !== '.' ) {
101 if ( !$subdomains || $path !== '/' ) {
102 $like .= $path . '%';