5 * @author Roland Haeder <webmaster@ship-simu.org>
7 * @copyright Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2012 Hub Developer Team
8 * @license GNU GPL 3.0 or any newer version
9 * @link http://www.ship-simu.org
11 * This program is free software: you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation, either version 3 of the License, or
14 * (at your option) any later version.
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with this program. If not, see <http://www.gnu.org/licenses/>.
24 class ChunkHandler extends BaseHandler implements HandleableChunks, Registerable {
26 * Stacker for chunks with final EOP
28 const STACKER_NAME_CHUNKS_WITH_FINAL_EOP = 'final_chunks';
29 const STACKER_NAME_CHUNKS_WITHOUT_FINAL = 'pending_chunks';
30 const STACKER_NAME_ASSEMBLED_RAW_DATA = 'chunk_raw_data';
38 const CHUNK_SPLITS_INDEX_HASH = 0;
39 const CHUNK_SPLITS_INDEX_SERIAL = 1;
40 const CHUNK_SPLITS_INDEX_RAW_DATA = 2;
43 * The final array for assembling the original package back together
45 private $finalPackageChunks = array();
48 * Array of chunk hashes
50 private $chunkHashes = array();
53 * Raw EOP chunk data in an array:
56 * 1 = Hash of last chunk
58 private $eopChunk = array();
63 private $rawPackageData = '';
66 * Protected constructor
70 protected function __construct () {
71 // Call parent constructor
72 parent::__construct(__CLASS__);
75 $this->setHandlerName('chunk');
82 * Creates an instance of this class
84 * @return $handlerInstance An instance of a chunk Handler class
86 public final static function createChunkHandler () {
88 $handlerInstance = new ChunkHandler();
91 $stackerInstance = ObjectFactory::createObjectByConfiguredName('chunk_handler_stacker_class');
94 $stackerInstance->initStackers(array(
95 self::STACKER_NAME_CHUNKS_WITH_FINAL_EOP,
96 self::STACKER_NAME_CHUNKS_WITHOUT_FINAL,
97 self::STACKER_NAME_ASSEMBLED_RAW_DATA
100 // Set the stacker in this handler
101 $handlerInstance->setStackerInstance($stackerInstance);
103 // Get a crypto instance ...
104 $cryptoInstance = ObjectFactory::createObjectByConfiguredName('crypto_class');
106 // ... and set it in this handler
107 $handlerInstance->setCryptoInstance($cryptoInstance);
109 // Get a fragmenter instance for later verification of serial numbers (e.g. if all are received)
110 $fragmenterInstance = FragmenterFactory::createFragmenterInstance('package');
112 // Set it in this handler
113 $handlerInstance->setFragmenterInstance($fragmenterInstance);
115 // Return the prepared instance
116 return $handlerInstance;
120 * Initializes the handler
124 private function initHandler () {
125 // Init finalPackageChunks
126 $this->finalPackageChunks = array(
127 // Array for package content
128 'content' => array(),
129 // ... and for the hashes
131 // ... marker for that the final array is complete for assembling all chunks
132 'is_complete' => FALSE,
133 // ... steps done to assemble all chunks
134 'assemble_steps' => 0,
138 $this->chunkHashes = array();
141 $this->eopChunk = array(
148 * Checks whether the hash generated from package content is the same ("valid") as given
150 * @param $chunkSplits An array from a splitted chunk
151 * @return $isValid Whether the hash is "valid"
153 private function isChunkHashValid (array $chunkSplits) {
154 // Now hash the raw data again
155 $chunkHash = $this->getCryptoInstance()->hashString($chunkSplits[self::CHUNK_SPLITS_INDEX_RAW_DATA], $chunkSplits[self::CHUNK_SPLITS_INDEX_HASH], FALSE);
158 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('CHUNK-HANDLER[' . __LINE__ . ']: chunkHash=' . $chunkHash . ',chunkSplits[chunk_hash]=' . $chunkSplits[self::CHUNK_SPLITS_INDEX_HASH] . ',chunkSplits[serial]=' . $chunkSplits[self::CHUNK_SPLITS_INDEX_SERIAL] . ',chunkSplits[raw_data]=' . $chunkSplits[self::CHUNK_SPLITS_INDEX_RAW_DATA]);
161 $isValid = ($chunkSplits[self::CHUNK_SPLITS_INDEX_HASH] === $chunkHash);
168 * Checks whether the given serial number is valid
170 * @param $serialNumber A serial number from a chunk
171 * @return $isValid Whether the serial number is valid
173 private function isSerialNumberValid ($serialNumber) {
175 $isValid = ((strlen($serialNumber) == PackageFragmenter::MAX_SERIAL_LENGTH) && ($this->hexval($serialNumber, FALSE) === $serialNumber));
182 * Adds the chunk to the final array which will be used for the final step
183 * which will be to assemble all chunks back to the original package content
184 * and for the final hash check.
186 * This method may throw an exception if a chunk with the same serial number
187 * has already been added to avoid mixing chunks from different packages.
189 * @param $chunkSplits An array from a splitted chunk
192 private function addChunkToFinalArray (array $chunkSplits) {
193 // Is the serial number (index 1) already been added?
194 if (isset($this->finalPackageChunks[$chunkSplits[self::CHUNK_SPLITS_INDEX_SERIAL]])) {
195 // Then throw an exception
196 throw new ChunkAlreadyAssembledException(array($this, $chunkSplits), self::EXCEPTION_CHUNK_ALREADY_ASSEMBLED);
200 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('CHUNK-HANDLER[' . __LINE__ . ']: serialNumber=' . $chunkSplits[self::CHUNK_SPLITS_INDEX_SERIAL] . ',hash=' . $chunkSplits[self::CHUNK_SPLITS_INDEX_HASH]);
202 // Add the chunk data (index 2) to the final array and use the serial number as index
203 $this->finalPackageChunks['content'][$chunkSplits[self::CHUNK_SPLITS_INDEX_SERIAL]] = $chunkSplits[self::CHUNK_SPLITS_INDEX_RAW_DATA];
205 // ... and the hash as well
206 $this->finalPackageChunks['hashes'][$chunkSplits[self::CHUNK_SPLITS_INDEX_SERIAL]] = $chunkSplits[self::CHUNK_SPLITS_INDEX_HASH];
210 * Marks the final array as completed, do only this if you really have all
211 * chunks together including EOP and "hash chunk".
215 private function markFinalArrayAsCompleted () {
217 * As for now, just set the array element. If any further steps are
218 * being added, this should always be the last step.
220 $this->finalPackageChunks['is_complete'] = TRUE;
224 * Sorts the chunks array by using the serial number as a sorting key. In
225 * most situations a call of ksort() is enough to accomblish this. So this
226 * method may only call ksort() on the chunks array.
228 * This method sorts 'content' and 'hashes' so both must have used the
229 * serial numbers as array indexes.
233 private function sortChunksArray () {
234 // Sort 'content' first
235 ksort($this->finalPackageChunks['content']);
238 ksort($this->finalPackageChunks['hashes']);
242 * Prepares the package assemble by removing last chunks (last shall be
243 * hash chunk, pre-last shall be EOP chunk) and verify that all serial
244 * numbers are valid (same as PackageFragmenter class would generate).
248 private function preparePackageAssmble () {
249 // Make sure both arrays have same count (this however should always be TRUE)
250 assert(count($this->finalPackageChunks['hashes']) == count($this->finalPackageChunks['content']));
251 //* DIE: */ exit(__METHOD__ . ':finalPackageChunks='.print_r($this->finalPackageChunks['content'], TRUE));
254 * Remove last element (hash chunk) from 'hashes'. This hash will never
255 * be needed, so ignore it.
257 array_pop($this->finalPackageChunks['hashes']);
259 // ... and from 'content' as well but save it for later use
260 $this->chunkHashes = explode(PackageFragmenter::CHUNK_HASH_SEPARATOR, substr(array_pop($this->finalPackageChunks['content']), strlen(PackageFragmenter::HASH_CHUNK_IDENTIFIER)));
262 // Remove EOP chunk and keep a copy of it
263 array_pop($this->finalPackageChunks['hashes']);
264 $this->eopChunk = explode(PackageFragmenter::CHUNK_HASH_SEPARATOR, substr(array_pop($this->finalPackageChunks['content']), strlen(PackageFragmenter::END_OF_PACKAGE_IDENTIFIER)));
266 // Verify all serial numbers
267 $this->verifyChunkSerialNumbers();
271 * Verifies all chunk serial numbers by using a freshly initialized
272 * fragmenter instance. Do ALWAYS sort the array and array_pop() the hash
273 * chunk before calling this method to avoid re-requests of many chunks.
277 private function verifyChunkSerialNumbers () {
278 // Reset the serial number generator
279 $this->getFragmenterInstance()->resetSerialNumber();
281 // "Walk" through all (content) chunks
282 foreach ($this->finalPackageChunks['content'] as $serialNumber => $content) {
283 // Get next serial number
284 $nextSerial = $this->getFragmenterInstance()->getNextHexSerialNumber();
287 //* NOISY-DEBUG */ self::createDebugInstance(__CLASS__)->debugOutput('CHUNK-HANDLER[' . __LINE__ . ']: serialNumber=' . $serialNumber . ',nextSerial=' . $nextSerial);
289 // Is it not the same? Then re-request it
290 if ($serialNumber != $nextSerial) {
291 // This is invalid, so remove it
292 unset($this->finalPackageChunks['content'][$serialNumber]);
293 unset($this->finalPackageChunks['hashes'][$serialNumber]);
295 // And re-request it with valid serial number (and hash chunk)
296 $this->rerequestChunkBySerialNumber($nextSerial);
302 * Assembles and verifies ("final check") chunks back together to the
303 * original package (raw data for the start). This method should only be
304 * called AFTER the EOP and final-chunk chunk have been removed.
308 private function assembleAllChunksToPackage () {
309 // If chunkHashes is not filled, don't continue
310 assert(count($this->chunkHashes) > 0);
312 // Init raw package data string
313 $this->rawPackageData = '';
315 // That went well, so start assembling all chunks
316 foreach ($this->finalPackageChunks['content'] as $serialNumber => $content) {
318 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('CHUNK-HANDLER[' . __LINE__ . ']: serialNumber=' . $serialNumber . ' - validating ...');
319 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('finalPackageChunks=' . print_r($this->finalPackageChunks, TRUE) . 'chunkHashes=' . print_r($this->chunkHashes, TRUE));
321 // Is this chunk valid? This should be the case
322 assert($this->isChunkHashValid(array(
323 self::CHUNK_SPLITS_INDEX_HASH => $this->finalPackageChunks['hashes'][$serialNumber],
324 self::CHUNK_SPLITS_INDEX_RAW_DATA => $content
327 // ... and is also in the hash chunk?
328 assert(in_array($this->finalPackageChunks['hashes'][$serialNumber], $this->chunkHashes));
330 // Verification okay, add it to the raw data
331 $this->rawPackageData .= $content;
335 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('CHUNK-HANDLER[' . __LINE__ . ']: eopChunk[1]=' . $this->eopChunk[1] . ',' . chr(10) . 'index=' . (count($this->chunkHashes) - 2) . ',' . chr(10) . 'chunkHashes='.print_r($this->chunkHashes, TRUE));
337 // The last chunk hash must match with the one from eopChunk[1]
338 assert($this->eopChunk[1] == $this->chunkHashes[count($this->chunkHashes) - 2]);
342 * Verifies the finally assembled raw package data by comparing it against
347 private function verifyRawPackageData () {
348 // Hash the raw package data for final verification
349 $finalHash = $this->getCryptoInstance()->hashString($this->rawPackageData, $this->eopChunk[0], FALSE);
352 assert($finalHash == $this->eopChunk[0]);
356 * Adds all chunks if the last one verifies as a 'final chunk'.
358 * @param $chunks An array with chunks, the last one should be a 'final'
360 * @throws FinalChunkVerificationException If the final chunk does not start with 'EOP:'
362 public function addAllChunksWithFinal (array $chunks) {
363 // Try to validate the final chunk
365 // Validate final chunk
366 $this->isValidFinalChunk($chunks);
367 } catch (AssertionException $e) {
368 // Last chunk is not valid
369 throw new FinalChunkVerificationException(array($this, $chunks, $e), BaseListener::EXCEPTION_FINAL_CHUNK_VERIFICATION);
372 // Do we have some pending chunks (no final)?
373 while (!$this->getStackerInstance()->isStackEmpty(self::STACKER_NAME_CHUNKS_WITHOUT_FINAL)) {
374 // Then get it first and add it before the EOP chunks
375 array_unshift($chunks, $this->getStackerInstance()->popNamed(self::STACKER_NAME_CHUNKS_WITHOUT_FINAL));
378 // Add all chunks to the FIFO stacker
379 foreach ($chunks as $chunk) {
381 $this->getStackerInstance()->pushNamed(self::STACKER_NAME_CHUNKS_WITH_FINAL_EOP, $chunk);
386 * Adds all chunks and wait for more (e.g. incomplete transmission)
388 * @param $chunks An array with chunks, the last one should be a 'final'
391 public function addAllChunksWait (array $chunks) {
392 // Add all chunks to the FIFO stacker
393 foreach ($chunks as $chunk) {
395 $this->getStackerInstance()->pushNamed(self::STACKER_NAME_CHUNKS_WITHOUT_FINAL, $chunk);
400 * Checks whether unhandled chunks are available
402 * @return $unhandledChunks Whether unhandled chunks are left
404 public function ifUnhandledChunksWithFinalAvailable () {
405 // Simply check if the stacker is not empty
406 $unhandledChunks = $this->getStackerInstance()->isStackEmpty(self::STACKER_NAME_CHUNKS_WITH_FINAL_EOP) === FALSE;
409 return $unhandledChunks;
413 * Handles available chunks by processing one-by-one (not all together,
414 * this would slow-down the whole application) with the help of an
419 public function handleAvailableChunksWithFinal () {
420 // First check if there are undhandled chunks available
421 assert($this->ifUnhandledChunksWithFinalAvailable());
423 // Get an entry from the stacker
424 $chunk = $this->getStackerInstance()->popNamed(self::STACKER_NAME_CHUNKS_WITH_FINAL_EOP);
426 // Split the string with proper separator character
427 $chunkSplits = explode(PackageFragmenter::CHUNK_DATA_HASH_SEPARATOR, $chunk);
430 * Make sure three elements are always found:
435 assert(count($chunkSplits) == 3);
437 // Is the generated hash from data same ("valid") as given hash?
438 if (!$this->isChunkHashValid($chunkSplits)) {
440 self::createDebugInstance(__CLASS__)->debugOutput('CHUNK-HANDLER[' . __LINE__ . ']: Chunk content is not validating against given hash.');
442 // Re-request this chunk (trust the hash in index # 0)
443 $this->rerequestChunkBySplitsArray($chunkSplits);
445 // Don't process this chunk
449 // Is the serial number valid (chars 0-9, length equals PackageFragmenter::MAX_SERIAL_LENGTH)?
450 if (!$this->isSerialNumberValid($chunkSplits[self::CHUNK_SPLITS_INDEX_SERIAL])) {
452 self::createDebugInstance(__CLASS__)->debugOutput('CHUNK-HANDLER[' . __LINE__ . ']: Chunk serial number ' . $chunkSplits[self::CHUNK_SPLITS_INDEX_SERIAL] . ' for hash ' . $chunkSplits[self::CHUNK_SPLITS_INDEX_HASH] . ' is invalid.');
454 // Re-request this chunk
455 $this->rerequestChunkBySplitsArray($chunkSplits);
457 // Don't process this chunk
462 * It is now known that (as long as the hash algorithm has no
463 * collisions) the content is the same as the sender sends it to this
466 * And also the serial number is valid (basicly) at this point. Now the
467 * chunk can be added to the final array.
469 $this->addChunkToFinalArray($chunkSplits);
471 // Is the stack now empty?
472 if ($this->getStackerInstance()->isStackEmpty(self::STACKER_NAME_CHUNKS_WITH_FINAL_EOP)) {
473 // Then mark the final array as complete
474 $this->markFinalArrayAsCompleted();
479 * Checks whether unassembled chunks are available (ready) in final array
481 * @return $unassembledChunksAvailable Whether unassembled chunks are available
483 public function ifUnassembledChunksAvailable () {
484 // For now do only check the array element 'is_complete'
485 $unassembledChunksAvailable = ($this->finalPackageChunks['is_complete'] === TRUE);
488 return $unassembledChunksAvailable;
492 * Assembles all chunks (except EOP and "hash chunk") back together to the original package data.
494 * This is done by the following steps:
496 * 1) Sort the final array with ksort(). This will bring the "hash
497 * chunk" up to the last array index and the EOP chunk to the
498 * pre-last array index
499 * 2) Assemble all chunks except two last (see above step)
500 * 3) While so, do the final check on all hashes
501 * 4) If the package is assembled back together, hash it again for
502 * the very final verification.
506 public function assembleChunksFromFinalArray () {
507 // Make sure the final array is really completed
508 assert($this->ifUnassembledChunksAvailable());
511 $this->finalPackageChunks['assemble_steps']++;
514 switch ($this->finalPackageChunks['assemble_steps']) {
515 case 1: // Sort the chunks array (the serial number shall act as a sorting key)
516 $this->sortChunksArray();
519 case 2: // Prepare the assemble by removing last two indexes
520 $this->preparePackageAssmble();
523 case 3: // Assemble all chunks back together to the original package
524 $this->assembleAllChunksToPackage();
527 case 4: // Verify the raw data by hashing it again
528 $this->verifyRawPackageData();
531 case 5: // Re-initialize handler to reset it to the old state
532 $this->initHandler();
535 default: // Invalid step found
536 self::createDebugInstance(__CLASS__)->debugOutput('CHUNK-HANDLER[' . __LINE__ . ']: Invalid step ' . $this->finalPackageChunks['assemble_steps'] . ' detected.');
542 * Checks whether the raw package data has been assembled back together.
543 * This can be safely assumed when rawPackageData is not empty and the
544 * collection of all chunks is FALSE (because initHandler() will reset it).
546 * @return $isRawPackageDataAvailable Whether raw package data is available
548 public function ifRawPackageDataIsAvailable () {
550 $isRawPackageDataAvailable = ((!empty($this->rawPackageData)) && (!$this->ifUnassembledChunksAvailable()));
553 return $isRawPackageDataAvailable;
557 * Handles the finally assembled raw package data by feeding it into another
558 * stacker for further decoding/processing.
562 public function handledAssembledRawPackageData () {
563 // Assert to make sure that there is raw package data available
564 assert($this->ifRawPackageDataIsAvailable());
566 // Then feed it into the next stacker
567 $this->getStackerInstance()->pushNamed(self::STACKER_NAME_ASSEMBLED_RAW_DATA, $this->rawPackageData);
570 $this->rawPackageData = '';