includes/Block.php

   1 <?php
   2 /**
   3  * Blocks and bans object
   4  */
   5
   6 /**
   7  * The block class
   8  * All the functions in this class assume the object is either explicitly
   9  * loaded or filled. It is not load-on-demand. There are no accessors.
  10  *
  11  * Globals used: $wgAutoblockExpiry, $wgAntiLockFlags
  12  *
  13  * @todo This could be used everywhere, but it isn't.
  14  */
  15 class Block
  16 {
  17         /* public*/ var $mAddress, $mUser, $mBy, $mReason, $mTimestamp, $mAuto, $mId, $mExpiry,
  18                                 $mRangeStart, $mRangeEnd, $mAnonOnly, $mEnableAutoblock, $mHideName;
  19         /* private */ var $mNetworkBits, $mIntegerAddr, $mForUpdate, $mFromMaster, $mByName;
  20
  21         const EB_KEEP_EXPIRED = 1;
  22         const EB_FOR_UPDATE = 2;
  23         const EB_RANGE_ONLY = 4;
  24
  25         function __construct( $address = '', $user = 0, $by = 0, $reason = '',
  26                 $timestamp = '' , $auto = 0, $expiry = '', $anonOnly = 0, $createAccount = 0, $enableAutoblock = 0,
  27                 $hideName = 0 )
  28         {
  29                 $this->mId = 0;
  30                 # Expand valid IPv6 addresses
  31                 $address = IP::sanitizeIP( $address );
  32                 $this->mAddress = $address;
  33                 $this->mUser = $user;
  34                 $this->mBy = $by;
  35                 $this->mReason = $reason;
  36                 $this->mTimestamp = wfTimestamp(TS_MW,$timestamp);
  37                 $this->mAuto = $auto;
  38                 $this->mAnonOnly = $anonOnly;
  39                 $this->mCreateAccount = $createAccount;
  40                 $this->mExpiry = self::decodeExpiry( $expiry );
  41                 $this->mEnableAutoblock = $enableAutoblock;
  42                 $this->mHideName = $hideName;
  43
  44                 $this->mForUpdate = false;
  45                 $this->mFromMaster = false;
  46                 $this->mByName = false;
  47                 $this->initialiseRange();
  48         }
  49
  50         static function newFromDB( $address, $user = 0, $killExpired = true )
  51         {
  52                 $block = new Block();
  53                 $block->load( $address, $user, $killExpired );
  54                 if ( $block->isValid() ) {
  55                         return $block;
  56                 } else {
  57                         return null;
  58                 }
  59         }
  60
  61         static function newFromID( $id )
  62         {
  63                 $dbr = wfGetDB( DB_SLAVE );
  64                 $res = $dbr->resultObject( $dbr->select( 'ipblocks', '*',
  65                         array( 'ipb_id' => $id ), __METHOD__ ) );
  66                 $block = new Block;
  67                 if ( $block->loadFromResult( $res ) ) {
  68                         return $block;
  69                 } else {
  70                         return null;
  71                 }
  72         }
  73
  74         function clear()
  75         {
  76                 $this->mAddress = $this->mReason = $this->mTimestamp = '';
  77                 $this->mId = $this->mAnonOnly = $this->mCreateAccount =
  78                         $this->mEnableAutoblock = $this->mAuto = $this->mUser =
  79                         $this->mBy = $this->mHideName = 0;
  80                 $this->mByName = false;
  81         }
  82
  83         /**
  84          * Get the DB object and set the reference parameter to the query options
  85          */
  86         function &getDBOptions( &$options )
  87         {
  88                 global $wgAntiLockFlags;
  89                 if ( $this->mForUpdate || $this->mFromMaster ) {
  90                         $db = wfGetDB( DB_MASTER );
  91                         if ( !$this->mForUpdate || ($wgAntiLockFlags & ALF_NO_BLOCK_LOCK) ) {
  92                                 $options = array();
  93                         } else {
  94                                 $options = array( 'FOR UPDATE' );
  95                         }
  96                 } else {
  97                         $db = wfGetDB( DB_SLAVE );
  98                         $options = array();
  99                 }
 100                 return $db;
 101         }
 102
 103         /**
 104          * Get a ban from the DB, with either the given address or the given username
 105          *
 106          * @param string $address The IP address of the user, or blank to skip IP blocks
 107          * @param integer $user The user ID, or zero for anonymous users
 108          * @param bool $killExpired Whether to delete expired rows while loading
 109          *
 110          */
 111         function load( $address = '', $user = 0, $killExpired = true )
 112         {
 113                 wfDebug( "Block::load: '$address', '$user', $killExpired\n" );
 114
 115                 $options = array();
 116                 $db =& $this->getDBOptions( $options );
 117
 118                 if ( 0 == $user && $address == '' ) {
 119                         # Invalid user specification, not blocked
 120                         $this->clear();
 121                         return false;
 122                 }
 123
 124                 # Try user block
 125                 if ( $user ) {
 126                         $res = $db->resultObject( $db->select( 'ipblocks', '*', array( 'ipb_user' => $user ),
 127                                 __METHOD__, $options ) );
 128                         if ( $this->loadFromResult( $res, $killExpired ) ) {
 129                                 return true;
 130                         }
 131                 }
 132
 133                 # Try IP block
 134                 # TODO: improve performance by merging this query with the autoblock one
 135                 # Slightly tricky while handling killExpired as well
 136                 if ( $address ) {
 137                         $conds = array( 'ipb_address' => $address, 'ipb_auto' => 0 );
 138                         $res = $db->resultObject( $db->select( 'ipblocks', '*', $conds, __METHOD__, $options ) );
 139                         if ( $this->loadFromResult( $res, $killExpired ) ) {
 140                                 if ( $user && $this->mAnonOnly ) {
 141                                         # Block is marked anon-only
 142                                         # Whitelist this IP address against autoblocks and range blocks
 143                                         $this->clear();
 144                                         return false;
 145                                 } else {
 146                                         return true;
 147                                 }
 148                         }
 149                 }
 150
 151                 # Try range block
 152                 if ( $this->loadRange( $address, $killExpired, $user ) ) {
 153                         if ( $user && $this->mAnonOnly ) {
 154                                 $this->clear();
 155                                 return false;
 156                         } else {
 157                                 return true;
 158                         }
 159                 }
 160
 161                 # Try autoblock
 162                 if ( $address ) {
 163                         $conds = array( 'ipb_address' => $address, 'ipb_auto' => 1 );
 164                         if ( $user ) {
 165                                 $conds['ipb_anon_only'] = 0;
 166                         }
 167                         $res = $db->resultObject( $db->select( 'ipblocks', '*', $conds, __METHOD__, $options ) );
 168                         if ( $this->loadFromResult( $res, $killExpired ) ) {
 169                                 return true;
 170                         }
 171                 }
 172
 173                 # Give up
 174                 $this->clear();
 175                 return false;
 176         }
 177
 178         /**
 179          * Fill in member variables from a result wrapper
 180          */
 181         function loadFromResult( ResultWrapper $res, $killExpired = true )
 182         {
 183                 $ret = false;
 184                 if ( 0 != $res->numRows() ) {
 185                         # Get first block
 186                         $row = $res->fetchObject();
 187                         $this->initFromRow( $row );
 188
 189                         if ( $killExpired ) {
 190                                 # If requested, delete expired rows
 191                                 do {
 192                                         $killed = $this->deleteIfExpired();
 193                                         if ( $killed ) {
 194                                                 $row = $res->fetchObject();
 195                                                 if ( $row ) {
 196                                                         $this->initFromRow( $row );
 197                                                 }
 198                                         }
 199                                 } while ( $killed && $row );
 200
 201                                 # If there were any left after the killing finished, return true
 202                                 if ( $row ) {
 203                                         $ret = true;
 204                                 }
 205                         } else {
 206                                 $ret = true;
 207                         }
 208                 }
 209                 $res->free();
 210                 return $ret;
 211         }
 212
 213         /**
 214          * Search the database for any range blocks matching the given address, and
 215          * load the row if one is found.
 216          */
 217         function loadRange( $address, $killExpired = true, $user = 0 )
 218         {
 219                 $iaddr = IP::toHex( $address );
 220                 if ( $iaddr === false ) {
 221                         # Invalid address
 222                         return false;
 223                 }
 224
 225                 # Only scan ranges which start in this /16, this improves search speed
 226                 # Blocks should not cross a /16 boundary.
 227                 $range = substr( $iaddr, 0, 4 );
 228
 229                 $options = array();
 230                 $db =& $this->getDBOptions( $options );
 231                 $conds = array(
 232                         "ipb_range_start LIKE '$range%'",
 233                         "ipb_range_start <= '$iaddr'",
 234                         "ipb_range_end >= '$iaddr'"
 235                 );
 236
 237                 if ( $user ) {
 238                         $conds['ipb_anon_only'] = 0;
 239                 }
 240
 241                 $res = $db->resultObject( $db->select( 'ipblocks', '*', $conds, __METHOD__, $options ) );
 242                 $success = $this->loadFromResult( $res, $killExpired );
 243                 return $success;
 244         }
 245
 246         /**
 247          * Determine if a given integer IPv4 address is in a given CIDR network
 248          * @deprecated Use IP::isInRange
 249          */
 250         function isAddressInRange( $addr, $range ) {
 251                 return IP::isInRange( $addr, $range );
 252         }
 253
 254         function initFromRow( $row )
 255         {
 256                 $this->mAddress = $row->ipb_address;
 257                 $this->mReason = $row->ipb_reason;
 258                 $this->mTimestamp = wfTimestamp(TS_MW,$row->ipb_timestamp);
 259                 $this->mUser = $row->ipb_user;
 260                 $this->mBy = $row->ipb_by;
 261                 $this->mAuto = $row->ipb_auto;
 262                 $this->mAnonOnly = $row->ipb_anon_only;
 263                 $this->mCreateAccount = $row->ipb_create_account;
 264                 $this->mEnableAutoblock = $row->ipb_enable_autoblock;
 265                 $this->mHideName = $row->ipb_deleted;
 266                 $this->mId = $row->ipb_id;
 267                 $this->mExpiry = self::decodeExpiry( $row->ipb_expiry );
 268                 if ( isset( $row->user_name ) ) {
 269                         $this->mByName = $row->user_name;
 270                 } else {
 271                         $this->mByName = false;
 272                 }
 273                 $this->mRangeStart = $row->ipb_range_start;
 274                 $this->mRangeEnd = $row->ipb_range_end;
 275         }
 276
 277         function initialiseRange()
 278         {
 279                 $this->mRangeStart = '';
 280                 $this->mRangeEnd = '';
 281
 282                 if ( $this->mUser == 0 ) {
 283                         list( $this->mRangeStart, $this->mRangeEnd ) = IP::parseRange( $this->mAddress );
 284                 }
 285         }
 286
 287         /**
 288          * Callback with a Block object for every block
 289          * @return integer number of blocks;
 290          */
 291         /*static*/ function enumBlocks( $callback, $tag, $flags = 0 )
 292         {
 293                 global $wgAntiLockFlags;
 294
 295                 $block = new Block();
 296                 if ( $flags & Block::EB_FOR_UPDATE ) {
 297                         $db = wfGetDB( DB_MASTER );
 298                         if ( $wgAntiLockFlags & ALF_NO_BLOCK_LOCK ) {
 299                                 $options = '';
 300                         } else {
 301                                 $options = 'FOR UPDATE';
 302                         }
 303                         $block->forUpdate( true );
 304                 } else {
 305                         $db = wfGetDB( DB_SLAVE );
 306                         $options = '';
 307                 }
 308                 if ( $flags & Block::EB_RANGE_ONLY ) {
 309                         $cond = " AND ipb_range_start <> ''";
 310                 } else {
 311                         $cond = '';
 312                 }
 313
 314                 $now = wfTimestampNow();
 315
 316                 list( $ipblocks, $user ) = $db->tableNamesN( 'ipblocks', 'user' );
 317
 318                 $sql = "SELECT $ipblocks.*,user_name FROM $ipblocks,$user " .
 319                         "WHERE user_id=ipb_by $cond ORDER BY ipb_timestamp DESC $options";
 320                 $res = $db->query( $sql, 'Block::enumBlocks' );
 321                 $num_rows = $db->numRows( $res );
 322
 323                 while ( $row = $db->fetchObject( $res ) ) {
 324                         $block->initFromRow( $row );
 325                         if ( ( $flags & Block::EB_RANGE_ONLY ) && $block->mRangeStart == '' ) {
 326                                 continue;
 327                         }
 328
 329                         if ( !( $flags & Block::EB_KEEP_EXPIRED ) ) {
 330                                 if ( $block->mExpiry && $now > $block->mExpiry ) {
 331                                         $block->delete();
 332                                 } else {
 333                                         call_user_func( $callback, $block, $tag );
 334                                 }
 335                         } else {
 336                                 call_user_func( $callback, $block, $tag );
 337                         }
 338                 }
 339                 $db->freeResult( $res );
 340                 return $num_rows;
 341         }
 342
 343         function delete()
 344         {
 345                 if (wfReadOnly()) {
 346                         return false;
 347                 }
 348                 if ( !$this->mId ) {
 349                         throw new MWException( "Block::delete() now requires that the mId member be filled\n" );
 350                 }
 351
 352                 $dbw = wfGetDB( DB_MASTER );
 353                 $dbw->delete( 'ipblocks', array( 'ipb_id' => $this->mId ), __METHOD__ );
 354                 return $dbw->affectedRows() > 0;
 355         }
 356
 357         /**
 358         * Insert a block into the block table.
 359         *@return Whether or not the insertion was successful.
 360         */
 361         function insert()
 362         {
 363                 wfDebug( "Block::insert; timestamp {$this->mTimestamp}\n" );
 364                 $dbw = wfGetDB( DB_MASTER );
 365
 366                 # Unset ipb_anon_only for user blocks, makes no sense
 367                 if ( $this->mUser ) {
 368                         $this->mAnonOnly = 0;
 369                 }
 370
 371                 # Unset ipb_enable_autoblock for IP blocks, makes no sense
 372                 if ( !$this->mUser ) {
 373                         $this->mEnableAutoblock = 0;
 374                 }
 375
 376                 # Don't collide with expired blocks
 377                 Block::purgeExpired();
 378
 379                 $ipb_id = $dbw->nextSequenceValue('ipblocks_ipb_id_val');
 380                 $dbw->insert( 'ipblocks',
 381                         array(
 382                                 'ipb_id' => $ipb_id,
 383                                 'ipb_address' => $this->mAddress,
 384                                 'ipb_user' => $this->mUser,
 385                                 'ipb_by' => $this->mBy,
 386                                 'ipb_reason' => $this->mReason,
 387                                 'ipb_timestamp' => $dbw->timestamp($this->mTimestamp),
 388                                 'ipb_auto' => $this->mAuto,
 389                                 'ipb_anon_only' => $this->mAnonOnly,
 390                                 'ipb_create_account' => $this->mCreateAccount,
 391                                 'ipb_enable_autoblock' => $this->mEnableAutoblock,
 392                                 'ipb_expiry' => self::encodeExpiry( $this->mExpiry, $dbw ),
 393                                 'ipb_range_start' => $this->mRangeStart,
 394                                 'ipb_range_end' => $this->mRangeEnd,
 395                                 'ipb_deleted'   => $this->mHideName
 396                         ), 'Block::insert', array( 'IGNORE' )
 397                 );
 398                 $affected = $dbw->affectedRows();
 399                 $dbw->commit();
 400
 401                 if ($affected)
 402                         $this->doRetroactiveAutoblock();
 403
 404                 return $affected;
 405         }
 406
 407         /**
 408         * Retroactively autoblocks the last IP used by the user (if it is a user)
 409         * blocked by this Block.
 410         *@return Whether or not a retroactive autoblock was made.
 411         */
 412         function doRetroactiveAutoblock() {
 413                 $dbr = wfGetDB( DB_SLAVE );
 414                 #If autoblock is enabled, autoblock the LAST IP used
 415                 # - stolen shamelessly from CheckUser_body.php
 416
 417                 if ($this->mEnableAutoblock && $this->mUser) {
 418                         wfDebug("Doing retroactive autoblocks for " . $this->mAddress . "\n");
 419
 420                         $row = $dbr->selectRow( 'recentchanges', array( 'rc_ip' ), array( 'rc_user_text' => $this->mAddress ),
 421                                 __METHOD__ , array( 'ORDER BY' => 'rc_timestamp DESC' ) );
 422
 423                         if ( !$row || !$row->rc_ip ) {
 424                                 #No results, don't autoblock anything
 425                                 wfDebug("No IP found to retroactively autoblock\n");
 426                         } else {
 427                                 #Limit is 1, so no loop needed.
 428                                 $retroblockip = $row->rc_ip;
 429                                 return $this->doAutoblock( $retroblockip, true );
 430                         }
 431                 }
 432         }
 433
 434         /**
 435         * Autoblocks the given IP, referring to this Block.
 436         * @param string $autoblockip The IP to autoblock.
 437         * @param bool $justInserted The main block was just inserted
 438         * @return bool Whether or not an autoblock was inserted.
 439         */
 440         function doAutoblock( $autoblockip, $justInserted = false ) {
 441                 # If autoblocks are disabled, go away.
 442                 if ( !$this->mEnableAutoblock ) {
 443                         return;
 444                 }
 445
 446                 # Check for presence on the autoblock whitelist
 447                 # TODO cache this?
 448                 $lines = explode( "\n", wfMsgForContentNoTrans( 'autoblock_whitelist' ) );
 449
 450                 $ip = $autoblockip;
 451
 452                 wfDebug("Checking the autoblock whitelist..\n");
 453
 454                 foreach( $lines as $line ) {
 455                         # List items only
 456                         if ( substr( $line, 0, 1 ) !== '*' ) {
 457                                 continue;
 458                         }
 459
 460                         $wlEntry = substr($line, 1);
 461                         $wlEntry = trim($wlEntry);
 462
 463                         wfDebug("Checking $ip against $wlEntry...");
 464
 465                         # Is the IP in this range?
 466                         if (IP::isInRange( $ip, $wlEntry )) {
 467                                 wfDebug(" IP $ip matches $wlEntry, not autoblocking\n");
 468                                 #$autoblockip = null; # Don't autoblock a whitelisted IP.
 469                                 return; #This /SHOULD/ introduce a dummy block - but
 470                                         # I don't know a safe way to do so. -werdna
 471                         } else {
 472                                 wfDebug( " No match\n" );
 473                         }
 474                 }
 475
 476                 # It's okay to autoblock. Go ahead and create/insert the block.
 477
 478                 $ipblock = Block::newFromDB( $autoblockip );
 479                 if ( $ipblock ) {
 480                         # If the user is already blocked. Then check if the autoblock would
 481                         # exceed the user block. If it would exceed, then do nothing, else
 482                         # prolong block time
 483                         if ($this->mExpiry &&
 484                         ($this->mExpiry < Block::getAutoblockExpiry($ipblock->mTimestamp))) {
 485                                 return;
 486                         }
 487                         # Just update the timestamp
 488                         if ( !$justInserted ) {
 489                                 $ipblock->updateTimestamp();
 490                         }
 491                         return;
 492                 } else {
 493                         $ipblock = new Block;
 494                 }
 495
 496                 # Make a new block object with the desired properties
 497                 wfDebug( "Autoblocking {$this->mAddress}@" . $autoblockip . "\n" );
 498                 $ipblock->mAddress = $autoblockip;
 499                 $ipblock->mUser = 0;
 500                 $ipblock->mBy = $this->mBy;
 501                 $ipblock->mReason = wfMsgForContent( 'autoblocker', $this->mAddress, $this->mReason );
 502                 $ipblock->mTimestamp = wfTimestampNow();
 503                 $ipblock->mAuto = 1;
 504                 $ipblock->mCreateAccount = $this->mCreateAccount;
 505                 # Continue suppressing the name if needed
 506                 $ipblock->mHideName = $this->mHideName;
 507
 508                 # If the user is already blocked with an expiry date, we don't
 509                 # want to pile on top of that!
 510                 if($this->mExpiry) {
 511                         $ipblock->mExpiry = min ( $this->mExpiry, Block::getAutoblockExpiry( $this->mTimestamp ));
 512                 } else {
 513                         $ipblock->mExpiry = Block::getAutoblockExpiry( $this->mTimestamp );
 514                 }
 515                 # Insert it
 516                 return $ipblock->insert();
 517         }
 518
 519         function deleteIfExpired()
 520         {
 521                 $fname = 'Block::deleteIfExpired';
 522                 wfProfileIn( $fname );
 523                 if ( $this->isExpired() ) {
 524                         wfDebug( "Block::deleteIfExpired() -- deleting\n" );
 525                         $this->delete();
 526                         $retVal = true;
 527                 } else {
 528                         wfDebug( "Block::deleteIfExpired() -- not expired\n" );
 529                         $retVal = false;
 530                 }
 531                 wfProfileOut( $fname );
 532                 return $retVal;
 533         }
 534
 535         function isExpired()
 536         {
 537                 wfDebug( "Block::isExpired() checking current " . wfTimestampNow() . " vs $this->mExpiry\n" );
 538                 if ( !$this->mExpiry ) {
 539                         return false;
 540                 } else {
 541                         return wfTimestampNow() > $this->mExpiry;
 542                 }
 543         }
 544
 545         function isValid()
 546         {
 547                 return $this->mAddress != '';
 548         }
 549
 550         function updateTimestamp()
 551         {
 552                 if ( $this->mAuto ) {
 553                         $this->mTimestamp = wfTimestamp();
 554                         $this->mExpiry = Block::getAutoblockExpiry( $this->mTimestamp );
 555
 556                         $dbw = wfGetDB( DB_MASTER );
 557                         $dbw->update( 'ipblocks',
 558                                 array( /* SET */
 559                                         'ipb_timestamp' => $dbw->timestamp($this->mTimestamp),
 560                                         'ipb_expiry' => $dbw->timestamp($this->mExpiry),
 561                                 ), array( /* WHERE */
 562                                         'ipb_address' => $this->mAddress
 563                                 ), 'Block::updateTimestamp'
 564                         );
 565                 }
 566         }
 567
 568         /*
 569         function getIntegerAddr()
 570         {
 571                 return $this->mIntegerAddr;
 572         }
 573
 574         function getNetworkBits()
 575         {
 576                 return $this->mNetworkBits;
 577         }*/
 578
 579         /**
 580          * @return The blocker user ID.
 581          */
 582         public function getBy() {
 583                 return $this->mBy;
 584         }
 585
 586         /**
 587          * @return The blocker user name.
 588          */
 589         function getByName()
 590         {
 591                 if ( $this->mByName === false ) {
 592                         $this->mByName = User::whoIs( $this->mBy );
 593                 }
 594                 return $this->mByName;
 595         }
 596
 597         function forUpdate( $x = NULL ) {
 598                 return wfSetVar( $this->mForUpdate, $x );
 599         }
 600
 601         function fromMaster( $x = NULL ) {
 602                 return wfSetVar( $this->mFromMaster, $x );
 603         }
 604
 605         function getRedactedName() {
 606                 if ( $this->mAuto ) {
 607                         return '#' . $this->mId;
 608                 } else {
 609                         return $this->mAddress;
 610                 }
 611         }
 612
 613         /**
 614          * Encode expiry for DB
 615          */
 616         static function encodeExpiry( $expiry, $db ) {
 617                 if ( $expiry == '' || $expiry == Block::infinity() ) {
 618                         return Block::infinity();
 619                 } else {
 620                         return $db->timestamp( $expiry );
 621                 }
 622         }
 623
 624         /**
 625          * Decode expiry which has come from the DB
 626          */
 627         static function decodeExpiry( $expiry ) {
 628                 if ( $expiry == '' || $expiry == Block::infinity() ) {
 629                         return Block::infinity();
 630                 } else {
 631                         return wfTimestamp( TS_MW, $expiry );
 632                 }
 633         }
 634
 635         static function getAutoblockExpiry( $timestamp )
 636         {
 637                 global $wgAutoblockExpiry;
 638                 return wfTimestamp( TS_MW, wfTimestamp( TS_UNIX, $timestamp ) + $wgAutoblockExpiry );
 639         }
 640
 641         /**
 642          * Gets rid of uneeded numbers in quad-dotted/octet IP strings
 643          * For example, 127.111.113.151/24 -> 127.111.113.0/24
 644          */
 645         static function normaliseRange( $range ) {
 646                 $parts = explode( '/', $range );
 647                 if ( count( $parts ) == 2 ) {
 648                         // IPv6
 649                         if ( IP::isIPv6($range) && $parts[1] >= 64 && $parts[1] <= 128 ) {
 650                                 $bits = $parts[1];
 651                                 $ipint = IP::toUnsigned6( $parts[0] );
 652                                 # Native 32 bit functions WONT work here!!!
 653                                 # Convert to a padded binary number
 654                                 $network = wfBaseConvert( $ipint, 10, 2, 128 );
 655                                 # Truncate the last (128-$bits) bits and replace them with zeros
 656                                 $network = str_pad( substr( $network, 0, $bits ), 128, 0, STR_PAD_RIGHT );
 657                                 # Convert back to an integer
 658                                 $network = wfBaseConvert( $network, 2, 10 );
 659                                 # Reform octet address
 660                                 $newip = IP::toOctet( $network );
 661                                 $range = "$newip/{$parts[1]}";
 662                         } // IPv4
 663                         else if ( IP::isIPv4($range) && $parts[1] >= 16 && $parts[1] <= 32 ) {
 664                                 $shift = 32 - $parts[1];
 665                                 $ipint = IP::toUnsigned( $parts[0] );
 666                                 $ipint = $ipint >> $shift << $shift;
 667                                 $newip = long2ip( $ipint );
 668                                 $range = "$newip/{$parts[1]}";
 669                         }
 670                 }
 671                 return $range;
 672         }
 673
 674         /**
 675          * Purge expired blocks from the ipblocks table
 676          */
 677         static function purgeExpired() {
 678                 $dbw = wfGetDB( DB_MASTER );
 679                 $dbw->delete( 'ipblocks', array( 'ipb_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ), __METHOD__ );
 680         }
 681
 682         static function infinity() {
 683                 # This is a special keyword for timestamps in PostgreSQL, and
 684                 # works with CHAR(14) as well because "i" sorts after all numbers.
 685                 return 'infinity';
 686
 687                 /*
 688                 static $infinity;
 689                 if ( !isset( $infinity ) ) {
 690                         $dbr = wfGetDB( DB_SLAVE );
 691                         $infinity = $dbr->bigTimestamp();
 692                 }
 693                 return $infinity;
 694                  */
 695         }
 696
 697 }
 698 ?>