Parser::processControlEntry() - Code Metrics - Inspection of "Resolves Issue-70, multiple $ORIGIN declarations a..." - Badcow/DNS - Measure and Improve Code Quality continuously with Scrutinizer

Passed

Pull Request — master (#79)

by Sam

created 2020-10-30 20:32 UTC

Parser::processControlEntry() A

↳ Parent: Parser

Complexity

Conditions	3
Paths	4

Size

Total Lines	10
Code Lines	6

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	7
CRAP Score	3

Importance

Changes	1
Bugs	0	Features	0

Metric	Value
cc	3
eloc	6
c	1
b	0
f	0
nc	4
nop	1
dl	0
loc	10
ccs	7
cts	7
cp	1
crap	3
rs	10

<?php

declare(strict_types=1);

/*
 * This file is part of Badcow DNS Library.
 *
 * (c) Samuel Williams <[email protected]>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Badcow\DNS\Parser;

use Badcow\DNS\Classes;
use Badcow\DNS\Rdata\Factory;
use Badcow\DNS\Rdata\RdataInterface;
use Badcow\DNS\Rdata\Types;
use Badcow\DNS\ResourceRecord;
use Badcow\DNS\Zone;
use Exception;

class Parser
{
    /**
     * @var Zone
     */
    private $zone;

    /**
     * Array of methods that take an ArrayIterator and return an Rdata object. The array key is the Rdata type.
     *
     * @var callable[]
     */
    private $rdataHandlers = [];

    /**
     * @var ResourceRecord
     */
    private $currentResourceRecord;

    /**
     * @var string
     */
    private $lastStatedDomain;

    /**
     * @var int
     */
    private $lastStatedTtl;

    /**
     * @var string
     */
    private $lastStatedClass;

    /**
     * @var string the current value, defaults to the Zone name
     */
    private $origin;

    /**
     * Parser constructor.
     */
    public function __construct(array $rdataHandlers = [])
    {
        $this->rdataHandlers = $rdataHandlers;
    }

    /**
     * @throws ParseException
     */
    public static function parse(string $name, string $zone, int $commentOptions = Comments::NONE): Zone
    {
        return (new self())->makeZone($name, $zone, $commentOptions);
    }

    /**
     * @throws ParseException
     */
    public function makeZone(string $name, string $string, int $commentOptions = Comments::NONE): Zone
    {
        $this->zone = new Zone($name);
        $this->origin = $name;
        $this->lastStatedDomain = $name;
        $normalisedZone = Normaliser::normalise($string, $commentOptions);

        foreach (explode(Tokens::LINE_FEED, $normalisedZone) as $line) {
            $this->processLine($line);
        }

        return $this->zone;
    }

    /**
     * @throws ParseException
     */
    private function processLine(string $line): void
    {
        list($entry, $comment) = $this->extractComment($line);

        $this->currentResourceRecord = new ResourceRecord();
        $this->currentResourceRecord->setComment($comment);

        if ('' === $entry) {
            $this->zone->addResourceRecord($this->currentResourceRecord);

            return;
        }

        $iterator = new ResourceRecordIterator($entry);

        if ($this->isControlEntry($iterator)) {
            $this->processControlEntry($iterator);

            return;
        }

        $this->processEntry($iterator);
        $this->zone->addResourceRecord($this->currentResourceRecord);
    }

    /**
     * @throws ParseException
     */
    private function processEntry(ResourceRecordIterator $iterator): void
    {
        if ($this->isTTL($iterator)) {
            $this->currentResourceRecord->setTtl(TimeFormat::toSeconds($iterator->current()));
            $iterator->next();
            $this->processEntry($iterator);

            return;
        }

        if ($this->isClass($iterator)) {
            $this->currentResourceRecord->setClass(strtoupper($iterator->current()));
            $iterator->next();
            $this->processEntry($iterator);

            return;
        }

        if ($this->isResourceName($iterator) && null === $this->currentResourceRecord->getName()) {

            $this->currentResourceRecord->setName($this->appendOrigin($iterator->current()));
            $iterator->next();
            $this->processEntry($iterator);

            return;
        }

        if ($this->isType($iterator)) {
            $this->currentResourceRecord->setRdata($this->extractRdata($iterator));
            $this->populateWithLastStated();

            return;
        }

        throw new ParseException(sprintf('Could not parse entry "%s".', implode(' ', $iterator->getArrayCopy())));
    }

    /**
     * If no domain-name, TTL, or class is set on the record, populate object with last stated value.
     *
     * @see https://www.ietf.org/rfc/rfc1035 Section 5.1
     */
    private function populateWithLastStated(): void
    {
        if (empty($this->currentResourceRecord->getName())) {
            $this->currentResourceRecord->setName($this->lastStatedDomain);
        } else {
            $this->lastStatedDomain = $this->currentResourceRecord->getName();
        }

        if (null === $this->currentResourceRecord->getTtl()) {
            $this->currentResourceRecord->setTtl($this->lastStatedTtl ?? $this->zone->getDefaultTTl());
        } else {
            $this->lastStatedTtl = $this->currentResourceRecord->getTtl();
        }

        if (null === $this->currentResourceRecord->getClass()) {
            $this->currentResourceRecord->setClass($this->lastStatedClass);
        } else {
            $this->lastStatedClass = $this->currentResourceRecord->getClass();
        }
    }

    /**
     * Append the $ORIGIN to a subdomain if:
     *  1) the current $ORIGIN is different, and
     *  2) the subdomain is not already fully qualified, or
     *  3) the subdomain is '@'.
     *
     * @param string $subdomain the subdomain to which the $ORIGIN needs to be appended
     *
     * @return string The concatenated string of the subdomain.$ORIGIN
     */
    private function appendOrigin(string $subdomain): string
    {
        if ($this->origin === $this->zone->getName()) {
            return $subdomain;
        }

        if ('.' === substr($subdomain, -1, 1)) {
            return $subdomain;
        }

        if ('@' === $subdomain) {
            return $this->origin;
        }

        return $subdomain.'.'.$this->origin;
    }

    /**
     * Processes control entries at the top of a BIND record, i.e. $ORIGIN, $TTL, $INCLUDE, etc.
     */
    private function processControlEntry(ResourceRecordIterator $iterator): void
    {
        if ('$TTL' === strtoupper($iterator->current())) {
            $iterator->next();
            $this->zone->setDefaultTtl(TimeFormat::toSeconds($iterator->current()));
        }

        if ('$ORIGIN' === strtoupper($iterator->current())) {
            $iterator->next();
            $this->origin = (string) $iterator->current();
        }
    }

    /**
     * Determine if iterant is a resource name.
     */
    private function isResourceName(ResourceRecordIterator $iterator): bool
    {
        // Look ahead and determine if the next token is a TTL, Class, or valid Type.
        $iterator->next();

        if (!$iterator->valid()) {
            return false;
        }

        $isName = $this->isTTL($iterator) ||
            $this->isClass($iterator, 'DOMAIN') ||
            $this->isType($iterator);
        $iterator->prev();

        if (!$isName) {
            return false;
        }

        if (0 === $iterator->key()) {
            return true;
        }

        return false;
    }

    /**
     * Determine if iterant is a class.
     *
     * @param string|null $origin the previously assumed resource record parameter, either 'TTL' or NULL
     */
    private function isClass(ResourceRecordIterator $iterator, $origin = null): bool
    {
        if (!Classes::isValid($iterator->current())) {
            return false;
        }

        $iterator->next();
        if ('TTL' === $origin) {
            $isClass = $this->isType($iterator);
        } else {
            $isClass = $this->isTTL($iterator, 'CLASS') || $this->isType($iterator);
        }
        $iterator->prev();

        return $isClass;
    }

    /**
     * Determine if current iterant is an Rdata type string.
     */
    private function isType(ResourceRecordIterator $iterator): bool
    {
        return Types::isValid(strtoupper($iterator->current())) || array_key_exists($iterator->current(), $this->rdataHandlers);
    }

    /**
     * Determine if iterant is a control entry such as $TTL, $ORIGIN, $INCLUDE, etcetera.
     */
    private function isControlEntry(ResourceRecordIterator $iterator): bool
    {
        return 1 === preg_match('/^\$[A-Z0-9]+/i', $iterator->current());
    }

    /**
     * Determine if the iterant is a TTL (i.e. it is an integer after domain-name).
     *
     * @param string $origin the previously assumed resource record parameter, either 'CLASS' or NULL
     */
    private function isTTL(ResourceRecordIterator $iterator, $origin = null): bool
    {
        if (!TimeFormat::isTimeFormat($iterator->current())) {
            return false;
        }

        if ($iterator->key() < 1) {
            return false;
        }

        $iterator->next();
        if ('CLASS' === $origin) {
            $isTtl = $this->isType($iterator);
        } else {
            $isTtl = $this->isClass($iterator, 'TTL') || $this->isType($iterator);
        }
        $iterator->prev();

        return $isTtl;
    }

    /**
     * Split a DNS zone line into a resource record and a comment.
     *
     * @return array [$entry, $comment]
     */
    private function extractComment(string $rr): array
    {
        $string = new StringIterator($rr);
        $entry = '';
        $comment = null;

        while ($string->valid()) {
            //If a semicolon is within double quotes, it will not be treated as the beginning of a comment.
            $entry .= $this->extractDoubleQuotedText($string);

            if ($string->is(Tokens::SEMICOLON)) {
                $string->next();
                $comment = $string->getRemainingAsString();

                break;
            }

            $entry .= $string->current();
            $string->next();
        }

        return [$entry, $comment];
    }

    /**
     * Extract text within double quotation context.
     */
    private function extractDoubleQuotedText(StringIterator $string): string
    {
        if ($string->isNot(Tokens::DOUBLE_QUOTES)) {
            return '';
        }

        $entry = $string->current();
        $string->next();

        while ($string->isNot(Tokens::DOUBLE_QUOTES)) {
            //If the current char is a backslash, treat the next char as being escaped.
            if ($string->is(Tokens::BACKSLASH)) {
                $entry .= $string->current();
                $string->next();
            }
            $entry .= $string->current();
            $string->next();
        }

        return $entry;
    }

    /**
     * @throws ParseException
     */
    private function extractRdata(ResourceRecordIterator $iterator): RdataInterface
    {
        $type = strtoupper($iterator->current());
        $iterator->next();

        if (array_key_exists($type, $this->rdataHandlers)) {
            return call_user_func($this->rdataHandlers[$type], $iterator);
        }

        try {
            return Factory::textToRdataType($type, $iterator->getRemainingAsString());
        } catch (Exception $exception) {
            throw new ParseException(sprintf('Could not extract Rdata from resource record "%s".', (string) $iterator), null, $exception);
        }
    }
}


1		<?php
2
3		declare(strict_types=1);
4
5		/*
6		* This file is part of Badcow DNS Library.
7		*
8		* (c) Samuel Williams <[email protected]>
9		*
10		* For the full copyright and license information, please view the LICENSE
11		* file that was distributed with this source code.
12		*/
13
14		namespace Badcow\DNS\Parser;
15
16		use Badcow\DNS\Classes;
17		use Badcow\DNS\Rdata\Factory;
18		use Badcow\DNS\Rdata\RdataInterface;
19		use Badcow\DNS\Rdata\Types;
20		use Badcow\DNS\ResourceRecord;
21		use Badcow\DNS\Zone;
22		use Exception;
23
24		class Parser
25		{
26		/**
27		* @var Zone
28		*/
29		private $zone;
30
31		/**
32		* Array of methods that take an ArrayIterator and return an Rdata object. The array key is the Rdata type.
33		*
34		* @var callable[]
35		*/
36		private $rdataHandlers = [];
37
38		/**
39		* @var ResourceRecord
40		*/
41		private $currentResourceRecord;
42
43		/**
44		* @var string
45		*/
46		private $lastStatedDomain;
47
48		/**
49		* @var int
50		*/
51		private $lastStatedTtl;
52
53		/**
54		* @var string
55		*/
56		private $lastStatedClass;
57
58		/**
59		* @var string the current value, defaults to the Zone name
60		*/
61		private $origin;
62
63		/**
64		* Parser constructor.
65		*/
66	28	public function __construct(array $rdataHandlers = [])
67		{
68	28	$this->rdataHandlers = $rdataHandlers;
69	28	}
70
71		/**
72		* @throws ParseException
73		*/
74	27	public static function parse(string $name, string $zone, int $commentOptions = Comments::NONE): Zone
75		{
76	27	return (new self())->makeZone($name, $zone, $commentOptions);
77		}
78
79		/**
80		* @throws ParseException
81		*/
82	28	public function makeZone(string $name, string $string, int $commentOptions = Comments::NONE): Zone
83		{
84	28	$this->zone = new Zone($name);
85	28	$this->origin = $name;
86	28	$this->lastStatedDomain = $name;
87	28	$normalisedZone = Normaliser::normalise($string, $commentOptions);
88
89	28	foreach (explode(Tokens::LINE_FEED, $normalisedZone) as $line) {
90	28	$this->processLine($line);
91		}
92
93	25	return $this->zone;
94		}
95
96		/**
97		* @throws ParseException
98		*/
99	28	private function processLine(string $line): void
100		{
101	28	list($entry, $comment) = $this->extractComment($line);
102
103	28	$this->currentResourceRecord = new ResourceRecord();
104	28	$this->currentResourceRecord->setComment($comment);
105
106	28	if ('' === $entry) {
107	2	$this->zone->addResourceRecord($this->currentResourceRecord);
108
109	2	return;
110		}
111
112	28	$iterator = new ResourceRecordIterator($entry);
113
114	28	if ($this->isControlEntry($iterator)) {
115	13	$this->processControlEntry($iterator);
116
117	13	return;
118		}
119
120	28	$this->processEntry($iterator);
121	25	$this->zone->addResourceRecord($this->currentResourceRecord);
122	25	}
123
124		/**
125		* @throws ParseException
126		*/
127	28	private function processEntry(ResourceRecordIterator $iterator): void
128		{
129	28	if ($this->isTTL($iterator)) {
130	15	$this->currentResourceRecord->setTtl(TimeFormat::toSeconds($iterator->current()));
131	15	$iterator->next();
132	15	$this->processEntry($iterator);
133
134	13	return;
135		}
136
137	28	if ($this->isClass($iterator)) {
138	25	$this->currentResourceRecord->setClass(strtoupper($iterator->current()));
139	25	$iterator->next();
140	25	$this->processEntry($iterator);
141
142	23	return;
143		}
144
145	28	if ($this->isResourceName($iterator) && null === $this->currentResourceRecord->getName()) {
		0 ignored issues – show introduced 2019-11-28 09:22 UTC by Report Bug Copy Issue Report The condition `null === $this->currentResourceRecord->getName()` is always `false`. Loading history...
146	27	$this->currentResourceRecord->setName($this->appendOrigin($iterator->current()));
147	27	$iterator->next();
148	27	$this->processEntry($iterator);
149
150	25	return;
151		}
152
153	28	if ($this->isType($iterator)) {
154	27	$this->currentResourceRecord->setRdata($this->extractRdata($iterator));
155	25	$this->populateWithLastStated();
156
157	25	return;
158		}
159
160	1	throw new ParseException(sprintf('Could not parse entry "%s".', implode(' ', $iterator->getArrayCopy())));
161		}
162
163		/**
164		* If no domain-name, TTL, or class is set on the record, populate object with last stated value.
165		*
166		* @see https://www.ietf.org/rfc/rfc1035 Section 5.1
167		*/
168	25	private function populateWithLastStated(): void
169		{
170	25	if (empty($this->currentResourceRecord->getName())) {
171	4	$this->currentResourceRecord->setName($this->lastStatedDomain);
172		} else {
173	24	$this->lastStatedDomain = $this->currentResourceRecord->getName();
174		}
175
176	25	if (null === $this->currentResourceRecord->getTtl()) {
177	15	$this->currentResourceRecord->setTtl($this->lastStatedTtl ?? $this->zone->getDefaultTTl());
178		} else {
179	13	$this->lastStatedTtl = $this->currentResourceRecord->getTtl();
180		}
181
182	25	if (null === $this->currentResourceRecord->getClass()) {
183		$this->currentResourceRecord->setClass($this->lastStatedClass);
184		} else {
185	25	$this->lastStatedClass = $this->currentResourceRecord->getClass();
186		}
187	25	}
188
189		/**
190		* Append the $ORIGIN to a subdomain if:
191		* 1) the current $ORIGIN is different, and
192		* 2) the subdomain is not already fully qualified, or
193		* 3) the subdomain is '@'.
194		*
195		* @param string $subdomain the subdomain to which the $ORIGIN needs to be appended
196		*
197		* @return string The concatenated string of the subdomain.$ORIGIN
198		*/
199	27	private function appendOrigin(string $subdomain): string
200		{
201	27	if ($this->origin === $this->zone->getName()) {
202	25	return $subdomain;
203		}
204
205	3	if ('.' === substr($subdomain, -1, 1)) {
206		return $subdomain;
207		}
208
209	3	if ('@' === $subdomain) {
210	3	return $this->origin;
211		}
212
213	2	return $subdomain.'.'.$this->origin;
214		}
215
216		/**
217		* Processes control entries at the top of a BIND record, i.e. $ORIGIN, $TTL, $INCLUDE, etc.
218		*/
219	13	private function processControlEntry(ResourceRecordIterator $iterator): void
220		{
221	13	if ('$TTL' === strtoupper($iterator->current())) {
222	11	$iterator->next();
223	11	$this->zone->setDefaultTtl(TimeFormat::toSeconds($iterator->current()));
224		}
225
226	13	if ('$ORIGIN' === strtoupper($iterator->current())) {
227	12	$iterator->next();
228	12	$this->origin = (string) $iterator->current();
229		}
230	13	}
231
232		/**
233		* Determine if iterant is a resource name.
234		*/
235	28	private function isResourceName(ResourceRecordIterator $iterator): bool
236		{
237		// Look ahead and determine if the next token is a TTL, Class, or valid Type.
238	28	$iterator->next();
239
240	28	if (!$iterator->valid()) {
241		return false;
242		}
243
244	28	$isName = $this->isTTL($iterator) \|\|
245	28	$this->isClass($iterator, 'DOMAIN') \|\|
246	28	$this->isType($iterator);
247	28	$iterator->prev();
248
249	28	if (!$isName) {
250	26	return false;
251		}
252
253	27	if (0 === $iterator->key()) {
254	27	return true;
255		}
256
257	4	return false;
258		}
259
260		/**
261		* Determine if iterant is a class.
262		*
263		* @param string\|null $origin the previously assumed resource record parameter, either 'TTL' or NULL
264		*/
265	28	private function isClass(ResourceRecordIterator $iterator, $origin = null): bool
266		{
267	28	if (!Classes::isValid($iterator->current())) {
268	28	return false;
269		}
270
271	26	$iterator->next();
272	26	if ('TTL' === $origin) {
273	12	$isClass = $this->isType($iterator);
274		} else {
275	25	$isClass = $this->isTTL($iterator, 'CLASS') \|\| $this->isType($iterator);
276		}
277	26	$iterator->prev();
278
279	26	return $isClass;
280		}
281
282		/**
283		* Determine if current iterant is an Rdata type string.
284		*/
285	28	private function isType(ResourceRecordIterator $iterator): bool
286		{
287	28	return Types::isValid(strtoupper($iterator->current())) \|\| array_key_exists($iterator->current(), $this->rdataHandlers);
288		}
289
290		/**
291		* Determine if iterant is a control entry such as $TTL, $ORIGIN, $INCLUDE, etcetera.
292		*/
293	28	private function isControlEntry(ResourceRecordIterator $iterator): bool
294		{
295	28	return 1 === preg_match('/^\$[A-Z0-9]+/i', $iterator->current());
296		}
297
298		/**
299		* Determine if the iterant is a TTL (i.e. it is an integer after domain-name).
300		*
301		* @param string $origin the previously assumed resource record parameter, either 'CLASS' or NULL
302		*/
303	28	private function isTTL(ResourceRecordIterator $iterator, $origin = null): bool
304		{
305	28	if (!TimeFormat::isTimeFormat($iterator->current())) {
306	28	return false;
307		}
308
309	26	if ($iterator->key() < 1) {
310	6	return false;
311		}
312
313	25	$iterator->next();
314	25	if ('CLASS' === $origin) {
315	5	$isTtl = $this->isType($iterator);
316		} else {
317	25	$isTtl = $this->isClass($iterator, 'TTL') \|\| $this->isType($iterator);
318		}
319	25	$iterator->prev();
320
321	25	return $isTtl;
322		}
323
324		/**
325		* Split a DNS zone line into a resource record and a comment.
326		*
327		* @return array [$entry, $comment]
328		*/
329	28	private function extractComment(string $rr): array
330		{
331	28	$string = new StringIterator($rr);
332	28	$entry = '';
333	28	$comment = null;
334
335	28	while ($string->valid()) {
336		//If a semicolon is within double quotes, it will not be treated as the beginning of a comment.
337	28	$entry .= $this->extractDoubleQuotedText($string);
338
339	28	if ($string->is(Tokens::SEMICOLON)) {
340	4	$string->next();
341	4	$comment = $string->getRemainingAsString();
342
343	4	break;
344		}
345
346	28	$entry .= $string->current();
347	28	$string->next();
348		}
349
350	28	return [$entry, $comment];
351		}
352
353		/**
354		* Extract text within double quotation context.
355		*/
356	28	private function extractDoubleQuotedText(StringIterator $string): string
357		{
358	28	if ($string->isNot(Tokens::DOUBLE_QUOTES)) {
359	28	return '';
360		}
361
362	13	$entry = $string->current();
363	13	$string->next();
364
365	13	while ($string->isNot(Tokens::DOUBLE_QUOTES)) {
366		//If the current char is a backslash, treat the next char as being escaped.
367	13	if ($string->is(Tokens::BACKSLASH)) {
368	7	$entry .= $string->current();
369	7	$string->next();
370		}
371	13	$entry .= $string->current();
372	13	$string->next();
373		}
374
375	13	return $entry;
376		}
377
378		/**
379		* @throws ParseException
380		*/
381	27	private function extractRdata(ResourceRecordIterator $iterator): RdataInterface
382		{
383	27	$type = strtoupper($iterator->current());
384	27	$iterator->next();
385
386	27	if (array_key_exists($type, $this->rdataHandlers)) {
387	1	return call_user_func($this->rdataHandlers[$type], $iterator);
388		}
389
390		try {
391	26	return Factory::textToRdataType($type, $iterator->getRemainingAsString());
392	2	} catch (Exception $exception) {
393	2	throw new ParseException(sprintf('Could not extract Rdata from resource record "%s".', (string) $iterator), null, $exception);
394		}
395		}
396		}
397

Badcow / DNS

Pull Request — master (#79)

Parser::processControlEntry() A

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