includes/Block.php

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