xref: /xnu-11215/libkern/c++/OSData.cpp (revision bb611c8f)
1 /*
2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
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15  * Please obtain a copy of the License at
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27  */
28 /* IOData.m created by rsulack on Thu 25-Sep-1997 */
29 
30 #include <string.h>
31 
32 __BEGIN_DECLS
33 #include <vm/vm_kern.h>
34 __END_DECLS
35 
36 #define IOKIT_ENABLE_SHARED_PTR
37 
38 #include <libkern/c++/OSData.h>
39 #include <libkern/c++/OSSerialize.h>
40 #include <libkern/c++/OSLib.h>
41 #include <libkern/c++/OSString.h>
42 #include <IOKit/IOLib.h>
43 
44 #define super OSObject
45 
46 OSDefineMetaClassAndStructorsWithZone(OSData, OSObject, ZC_ZFREE_CLEARMEM)
47 OSMetaClassDefineReservedUsedX86(OSData, 0);    // setDeallocFunction
48 OSMetaClassDefineReservedUnused(OSData, 1);
49 OSMetaClassDefineReservedUnused(OSData, 2);
50 OSMetaClassDefineReservedUnused(OSData, 3);
51 OSMetaClassDefineReservedUnused(OSData, 4);
52 OSMetaClassDefineReservedUnused(OSData, 5);
53 OSMetaClassDefineReservedUnused(OSData, 6);
54 OSMetaClassDefineReservedUnused(OSData, 7);
55 
56 #define EXTERNAL ((unsigned int) -1)
57 
58 bool
59 OSData::initWithCapacity(unsigned int inCapacity)
60 {
61 	void *_data = NULL;
62 
63 	if (data) {
64 		OSCONTAINER_ACCUMSIZE(-((size_t)capacity));
65 		if (!inCapacity || (capacity < inCapacity)) {
66 			// clean out old data's storage if it isn't big enough
67 			if (capacity < page_size) {
68 				kfree_data_container(data, capacity);
69 			} else {
70 				kmem_free(kernel_map, (vm_offset_t)data, capacity);
71 			}
72 			data = NULL;
73 			capacity = 0;
74 		}
75 	}
76 
77 	if (!super::init()) {
78 		return false;
79 	}
80 
81 	if (inCapacity && !data) {
82 		if (inCapacity < page_size) {
83 			data = (void *)kalloc_data_container(inCapacity, Z_WAITOK);
84 		} else {
85 			kern_return_t kr;
86 			if (round_page_overflow(inCapacity, &inCapacity)) {
87 				kr = KERN_RESOURCE_SHORTAGE;
88 			} else {
89 				kr = kmem_alloc(kernel_map, (vm_offset_t *)&_data, inCapacity, IOMemoryTag(kernel_map));
90 				data = _data;
91 			}
92 			if (KERN_SUCCESS != kr) {
93 				data = NULL;
94 			}
95 		}
96 		if (!data) {
97 			return false;
98 		}
99 		capacity = inCapacity;
100 	}
101 	OSCONTAINER_ACCUMSIZE(capacity);
102 
103 	length = 0;
104 	if (inCapacity < 16) {
105 		capacityIncrement = 16;
106 	} else {
107 		capacityIncrement = inCapacity;
108 	}
109 
110 	return true;
111 }
112 
113 bool
114 OSData::initWithBytes(const void *bytes, unsigned int inLength)
115 {
116 	if ((inLength && !bytes) || !initWithCapacity(inLength)) {
117 		return false;
118 	}
119 
120 	if (bytes != data) {
121 		bcopy(bytes, data, inLength);
122 	}
123 	length = inLength;
124 
125 	return true;
126 }
127 
128 bool
129 OSData::initWithBytesNoCopy(void *bytes, unsigned int inLength)
130 {
131 	if (!super::init()) {
132 		return false;
133 	}
134 
135 	length = inLength;
136 	capacity = EXTERNAL;
137 	data = bytes;
138 
139 	return true;
140 }
141 
142 bool
143 OSData::initWithData(const OSData *inData)
144 {
145 	return initWithBytes(inData->data, inData->length);
146 }
147 
148 bool
149 OSData::initWithData(const OSData *inData,
150     unsigned int start, unsigned int inLength)
151 {
152 	const void *localData = inData->getBytesNoCopy(start, inLength);
153 
154 	if (localData) {
155 		return initWithBytes(localData, inLength);
156 	} else {
157 		return false;
158 	}
159 }
160 
161 OSSharedPtr<OSData>
162 OSData::withCapacity(unsigned int inCapacity)
163 {
164 	OSSharedPtr<OSData> me = OSMakeShared<OSData>();
165 
166 	if (me && !me->initWithCapacity(inCapacity)) {
167 		return nullptr;
168 	}
169 
170 	return me;
171 }
172 
173 OSSharedPtr<OSData>
174 OSData::withBytes(const void *bytes, unsigned int inLength)
175 {
176 	OSSharedPtr<OSData> me = OSMakeShared<OSData>();
177 
178 	if (me && !me->initWithBytes(bytes, inLength)) {
179 		return nullptr;
180 	}
181 	return me;
182 }
183 
184 OSSharedPtr<OSData>
185 OSData::withBytesNoCopy(void *bytes, unsigned int inLength)
186 {
187 	OSSharedPtr<OSData> me = OSMakeShared<OSData>();
188 
189 	if (me && !me->initWithBytesNoCopy(bytes, inLength)) {
190 		return nullptr;
191 	}
192 
193 	return me;
194 }
195 
196 OSSharedPtr<OSData>
197 OSData::withData(const OSData *inData)
198 {
199 	OSSharedPtr<OSData> me = OSMakeShared<OSData>();
200 
201 	if (me && !me->initWithData(inData)) {
202 		return nullptr;
203 	}
204 
205 	return me;
206 }
207 
208 OSSharedPtr<OSData>
209 OSData::withData(const OSData *inData,
210     unsigned int start, unsigned int inLength)
211 {
212 	OSSharedPtr<OSData> me = OSMakeShared<OSData>();
213 
214 	if (me && !me->initWithData(inData, start, inLength)) {
215 		return nullptr;
216 	}
217 
218 	return me;
219 }
220 
221 void
222 OSData::free()
223 {
224 	if ((capacity != EXTERNAL) && data && capacity) {
225 		if (capacity < page_size) {
226 			kfree_data_container(data, capacity);
227 		} else {
228 			kmem_free(kernel_map, (vm_offset_t)data, capacity);
229 		}
230 		OSCONTAINER_ACCUMSIZE( -((size_t)capacity));
231 	} else if (capacity == EXTERNAL) {
232 		DeallocFunction freemem = reserved ? reserved->deallocFunction : NULL;
233 		if (freemem && data && length) {
234 			freemem(data, length);
235 		}
236 	}
237 	if (reserved) {
238 		kfree(reserved, sizeof(ExpansionData));
239 	}
240 	super::free();
241 }
242 
243 unsigned int
244 OSData::getLength() const
245 {
246 	return length;
247 }
248 unsigned int
249 OSData::getCapacity() const
250 {
251 	return capacity;
252 }
253 
254 unsigned int
255 OSData::getCapacityIncrement() const
256 {
257 	return capacityIncrement;
258 }
259 
260 unsigned int
261 OSData::setCapacityIncrement(unsigned increment)
262 {
263 	return capacityIncrement = increment;
264 }
265 
266 // xx-review: does not check for capacity == EXTERNAL
267 
268 unsigned int
269 OSData::ensureCapacity(unsigned int newCapacity)
270 {
271 	unsigned char * newData;
272 	unsigned int finalCapacity;
273 	void * copydata;
274 	kern_return_t kr;
275 
276 	if (newCapacity <= capacity) {
277 		return capacity;
278 	}
279 
280 	finalCapacity = (((newCapacity - 1) / capacityIncrement) + 1)
281 	    * capacityIncrement;
282 
283 	// integer overflow check
284 	if (finalCapacity < newCapacity) {
285 		return capacity;
286 	}
287 
288 	copydata = data;
289 
290 	if (finalCapacity >= page_size) {
291 		// round up
292 		finalCapacity = round_page_32(finalCapacity);
293 		// integer overflow check
294 		if (finalCapacity < newCapacity) {
295 			return capacity;
296 		}
297 		if (capacity >= page_size) {
298 			copydata = NULL;
299 			kr = kmem_realloc(kernel_map,
300 			    (vm_offset_t)data,
301 			    capacity,
302 			    (vm_offset_t *)&newData,
303 			    finalCapacity,
304 			    IOMemoryTag(kernel_map));
305 		} else {
306 			kr = kmem_alloc(kernel_map, (vm_offset_t *)&newData, finalCapacity, IOMemoryTag(kernel_map));
307 		}
308 		if (KERN_SUCCESS != kr) {
309 			newData = NULL;
310 		}
311 	} else {
312 		newData = (unsigned char *)kalloc_data_container(finalCapacity, Z_WAITOK);
313 	}
314 
315 	if (newData) {
316 		bzero(newData + capacity, finalCapacity - capacity);
317 		if (copydata) {
318 			bcopy(copydata, newData, capacity);
319 		}
320 		if (data) {
321 			if (capacity < page_size) {
322 				kfree_data_container(data, capacity);
323 			} else {
324 				kmem_free(kernel_map, (vm_offset_t)data, capacity);
325 			}
326 		}
327 		OSCONTAINER_ACCUMSIZE(((size_t)finalCapacity) - ((size_t)capacity));
328 		data = (void *) newData;
329 		capacity = finalCapacity;
330 	}
331 
332 	return capacity;
333 }
334 
335 bool
336 OSData::appendBytes(const void *bytes, unsigned int inLength)
337 {
338 	unsigned int newSize;
339 
340 	if (!inLength) {
341 		return true;
342 	}
343 
344 	if (capacity == EXTERNAL) {
345 		return false;
346 	}
347 
348 	if (os_add_overflow(length, inLength, &newSize)) {
349 		return false;
350 	}
351 
352 	if ((newSize > capacity) && newSize > ensureCapacity(newSize)) {
353 		return false;
354 	}
355 
356 	if (bytes) {
357 		bcopy(bytes, &((unsigned char *)data)[length], inLength);
358 	} else {
359 		bzero(&((unsigned char *)data)[length], inLength);
360 	}
361 
362 	length = newSize;
363 
364 	return true;
365 }
366 
367 bool
368 OSData::appendByte(unsigned char byte, unsigned int inLength)
369 {
370 	unsigned int newSize;
371 
372 	if (!inLength) {
373 		return true;
374 	}
375 
376 	if (capacity == EXTERNAL) {
377 		return false;
378 	}
379 
380 	if (os_add_overflow(length, inLength, &newSize)) {
381 		return false;
382 	}
383 
384 	if ((newSize > capacity) && newSize > ensureCapacity(newSize)) {
385 		return false;
386 	}
387 
388 	memset(&((unsigned char *)data)[length], byte, inLength);
389 	length = newSize;
390 
391 	return true;
392 }
393 
394 bool
395 OSData::appendBytes(const OSData *other)
396 {
397 	return appendBytes(other->data, other->length);
398 }
399 
400 const void *
401 OSData::getBytesNoCopy() const
402 {
403 	if (!length) {
404 		return NULL;
405 	} else {
406 		return data;
407 	}
408 }
409 
410 const void *
411 OSData::getBytesNoCopy(unsigned int start,
412     unsigned int inLength) const
413 {
414 	const void *outData = NULL;
415 
416 	if (length
417 	    && start < length
418 	    && (start + inLength) >= inLength // overflow check
419 	    && (start + inLength) <= length) {
420 		outData = (const void *) ((char *) data + start);
421 	}
422 
423 	return outData;
424 }
425 
426 bool
427 OSData::isEqualTo(const OSData *aData) const
428 {
429 	unsigned int len;
430 
431 	len = aData->length;
432 	if (length != len) {
433 		return false;
434 	}
435 
436 	return isEqualTo(aData->data, len);
437 }
438 
439 bool
440 OSData::isEqualTo(const void *someData, unsigned int inLength) const
441 {
442 	return (length >= inLength) && (bcmp(data, someData, inLength) == 0);
443 }
444 
445 bool
446 OSData::isEqualTo(const OSMetaClassBase *obj) const
447 {
448 	OSData *    otherData;
449 	OSString *  str;
450 
451 	if ((otherData = OSDynamicCast(OSData, obj))) {
452 		return isEqualTo(otherData);
453 	} else if ((str = OSDynamicCast(OSString, obj))) {
454 		return isEqualTo(str);
455 	} else {
456 		return false;
457 	}
458 }
459 
460 bool
461 OSData::isEqualTo(const OSString *obj) const
462 {
463 	const char * aCString;
464 	char * dataPtr;
465 	unsigned int checkLen = length;
466 	unsigned int stringLen;
467 
468 	if (!obj) {
469 		return false;
470 	}
471 
472 	stringLen = obj->getLength();
473 
474 	dataPtr = (char *)data;
475 
476 	if (stringLen != checkLen) {
477 		// check for the fact that OSData may be a buffer that
478 		// that includes a termination byte and will thus have
479 		// a length of the actual string length PLUS 1. In this
480 		// case we verify that the additional byte is a terminator
481 		// and if so count the two lengths as being the same.
482 
483 		if ((checkLen - stringLen) == 1) {
484 			if (dataPtr[checkLen - 1] != 0) { // non-zero means not a terminator and thus not likely the same
485 				return false;
486 			}
487 			checkLen--;
488 		} else {
489 			return false;
490 		}
491 	}
492 
493 	aCString = obj->getCStringNoCopy();
494 
495 	for (unsigned int i = 0; i < checkLen; i++) {
496 		if (*dataPtr++ != aCString[i]) {
497 			return false;
498 		}
499 	}
500 
501 	return true;
502 }
503 
504 //this was taken from CFPropertyList.c
505 static const char __CFPLDataEncodeTable[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
506 
507 bool
508 OSData::serialize(OSSerialize *s) const
509 {
510 	unsigned int i;
511 	const unsigned char *p;
512 	unsigned char c;
513 	unsigned int serializeLength;
514 
515 	if (s->previouslySerialized(this)) {
516 		return true;
517 	}
518 
519 	if (!s->addXMLStartTag(this, "data")) {
520 		return false;
521 	}
522 
523 	serializeLength = length;
524 	if (reserved && reserved->disableSerialization) {
525 		serializeLength = 0;
526 	}
527 
528 	for (i = 0, p = (unsigned char *)data; i < serializeLength; i++, p++) {
529 		/* 3 bytes are encoded as 4 */
530 		switch (i % 3) {
531 		case 0:
532 			c = __CFPLDataEncodeTable[((p[0] >> 2) & 0x3f)];
533 			if (!s->addChar(c)) {
534 				return false;
535 			}
536 			break;
537 		case 1:
538 			c = __CFPLDataEncodeTable[((((p[-1] << 8) | p[0]) >> 4) & 0x3f)];
539 			if (!s->addChar(c)) {
540 				return false;
541 			}
542 			break;
543 		case 2:
544 			c = __CFPLDataEncodeTable[((((p[-1] << 8) | p[0]) >> 6) & 0x3f)];
545 			if (!s->addChar(c)) {
546 				return false;
547 			}
548 			c = __CFPLDataEncodeTable[(p[0] & 0x3f)];
549 			if (!s->addChar(c)) {
550 				return false;
551 			}
552 			break;
553 		}
554 	}
555 	switch (i % 3) {
556 	case 0:
557 		break;
558 	case 1:
559 		c = __CFPLDataEncodeTable[((p[-1] << 4) & 0x30)];
560 		if (!s->addChar(c)) {
561 			return false;
562 		}
563 		if (!s->addChar('=')) {
564 			return false;
565 		}
566 		if (!s->addChar('=')) {
567 			return false;
568 		}
569 		break;
570 	case 2:
571 		c = __CFPLDataEncodeTable[((p[-1] << 2) & 0x3c)];
572 		if (!s->addChar(c)) {
573 			return false;
574 		}
575 		if (!s->addChar('=')) {
576 			return false;
577 		}
578 		break;
579 	}
580 
581 	return s->addXMLEndTag("data");
582 }
583 
584 void
585 OSData::setDeallocFunction(DeallocFunction func)
586 {
587 	if (!reserved) {
588 		reserved = (typeof(reserved))kalloc_container(sizeof(ExpansionData));
589 		if (!reserved) {
590 			return;
591 		}
592 		bzero(reserved, sizeof(ExpansionData));
593 	}
594 	reserved->deallocFunction = func;
595 }
596 
597 void
598 OSData::setSerializable(bool serializable)
599 {
600 	if (!reserved) {
601 		reserved = (typeof(reserved))kalloc_container(sizeof(ExpansionData));
602 		if (!reserved) {
603 			return;
604 		}
605 		bzero(reserved, sizeof(ExpansionData));
606 	}
607 	reserved->disableSerialization = (!serializable);
608 }
609 
610 bool
611 OSData::isSerializable(void)
612 {
613 	return !reserved || !reserved->disableSerialization;
614 }
615