xref: /xnu-11215/libkern/c++/OSSerialize.cpp (revision e6231be0)
1 /*
2  * Copyright (c) 2000-2006 Apple Computer, Inc. All rights reserved.
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8  * Version 2.0 (the 'License'). You may not use this file except in
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15  * Please obtain a copy of the License at
16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
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27  */
28 /* OSSerialize.cpp created by rsulack on Wen 25-Nov-1998 */
29 
30 #define IOKIT_ENABLE_SHARED_PTR
31 
32 #include <sys/cdefs.h>
33 #include <vm/vm_kern.h>
34 
35 #include <libkern/c++/OSContainers.h>
36 #include <libkern/c++/OSLib.h>
37 #include <libkern/c++/OSDictionary.h>
38 #include <libkern/c++/OSSharedPtr.h>
39 #include <libkern/OSSerializeBinary.h>
40 #include <libkern/Block.h>
41 #include <IOKit/IOLib.h>
42 
43 #define super OSObject
44 
45 OSDefineMetaClassAndStructors(OSSerialize, OSObject)
46 OSMetaClassDefineReservedUnused(OSSerialize, 0);
47 OSMetaClassDefineReservedUnused(OSSerialize, 1);
48 OSMetaClassDefineReservedUnused(OSSerialize, 2);
49 OSMetaClassDefineReservedUnused(OSSerialize, 3);
50 OSMetaClassDefineReservedUnused(OSSerialize, 4);
51 OSMetaClassDefineReservedUnused(OSSerialize, 5);
52 OSMetaClassDefineReservedUnused(OSSerialize, 6);
53 OSMetaClassDefineReservedUnused(OSSerialize, 7);
54 
55 
56 char *
57 OSSerialize::text() const
58 {
59 	return data;
60 }
61 
62 void
63 OSSerialize::clearText()
64 {
65 	if (binary) {
66 		length = sizeof(kOSSerializeBinarySignature);
67 		bzero(&data[length], capacity - length);
68 		endCollection = true;
69 	} else {
70 		bzero((void *)data, capacity);
71 		length = 1;
72 	}
73 	tags->flushCollection();
74 }
75 
76 bool
77 OSSerialize::previouslySerialized(const OSMetaClassBase *o)
78 {
79 	char temp[16];
80 	unsigned int tagIdx;
81 
82 	if (binary) {
83 		return binarySerialize(o);
84 	}
85 
86 	// look it up
87 	tagIdx = tags->getNextIndexOfObject(o, 0);
88 
89 // xx-review: no error checking here for addString calls!
90 	// does it exist?
91 	if (tagIdx != -1U) {
92 		addString("<reference IDREF=\"");
93 		snprintf(temp, sizeof(temp), "%u", tagIdx);
94 		addString(temp);
95 		addString("\"/>");
96 		return true;
97 	}
98 
99 	// add to tag array
100 	tags->setObject(o);// XXX check return
101 
102 	return false;
103 }
104 
105 bool
106 OSSerialize::addXMLStartTag(const OSMetaClassBase *o, const char *tagString)
107 {
108 	char temp[16];
109 	unsigned int tagIdx;
110 
111 	if (binary) {
112 		printf("class %s: xml serialize\n", o->getMetaClass()->getClassName());
113 		return false;
114 	}
115 
116 	if (!addChar('<')) {
117 		return false;
118 	}
119 	if (!addString(tagString)) {
120 		return false;
121 	}
122 	if (!addString(" ID=\"")) {
123 		return false;
124 	}
125 	tagIdx = tags->getNextIndexOfObject(o, 0);
126 	assert(tagIdx != -1U);
127 	snprintf(temp, sizeof(temp), "%u", tagIdx);
128 	if (!addString(temp)) {
129 		return false;
130 	}
131 	if (!addChar('\"')) {
132 		return false;
133 	}
134 	if (!addChar('>')) {
135 		return false;
136 	}
137 	return true;
138 }
139 
140 bool
141 OSSerialize::addXMLEndTag(const char *tagString)
142 {
143 	if (!addChar('<')) {
144 		return false;
145 	}
146 	if (!addChar('/')) {
147 		return false;
148 	}
149 	if (!addString(tagString)) {
150 		return false;
151 	}
152 	if (!addChar('>')) {
153 		return false;
154 	}
155 	return true;
156 }
157 
158 bool
159 OSSerialize::addChar(const char c)
160 {
161 	if (binary) {
162 		printf("xml serialize\n");
163 		return false;
164 	}
165 
166 	// add char, possibly extending our capacity
167 	if (length >= capacity && length >= ensureCapacity(capacity + capacityIncrement)) {
168 		return false;
169 	}
170 
171 	data[length - 1] = c;
172 	length++;
173 
174 	return true;
175 }
176 
177 bool
178 OSSerialize::addString(const char *s)
179 {
180 	bool rc = false;
181 
182 	while (*s && (rc = addChar(*s++))) {
183 		;
184 	}
185 
186 	return rc;
187 }
188 
189 bool
190 OSSerialize::initWithCapacity(unsigned int inCapacity)
191 {
192 	if (!super::init()) {
193 		return false;
194 	}
195 
196 	tags = OSArray::withCapacity(256);
197 	if (!tags) {
198 		return false;
199 	}
200 
201 	length = 1;
202 
203 	if (!inCapacity) {
204 		inCapacity = 1;
205 	}
206 	if (round_page_overflow(inCapacity, &capacity)) {
207 		tags.reset();
208 		return false;
209 	}
210 
211 	capacityIncrement = capacity;
212 
213 	// allocate from the kernel map so that we can safely map this data
214 	// into user space (the primary use of the OSSerialize object)
215 
216 	kern_return_t rc = kmem_alloc(kernel_map, (vm_offset_t *)&data, capacity, IOMemoryTag(kernel_map));
217 	if (rc) {
218 		return false;
219 	}
220 	bzero((void *)data, capacity);
221 
222 
223 	OSCONTAINER_ACCUMSIZE(capacity);
224 
225 	return true;
226 }
227 
228 OSSharedPtr<OSSerialize>
229 OSSerialize::withCapacity(unsigned int inCapacity)
230 {
231 	OSSharedPtr<OSSerialize> me = OSMakeShared<OSSerialize>();
232 
233 	if (me && !me->initWithCapacity(inCapacity)) {
234 		return nullptr;
235 	}
236 
237 	return me;
238 }
239 
240 unsigned int
241 OSSerialize::getLength() const
242 {
243 	return length;
244 }
245 unsigned int
246 OSSerialize::getCapacity() const
247 {
248 	return capacity;
249 }
250 unsigned int
251 OSSerialize::getCapacityIncrement() const
252 {
253 	return capacityIncrement;
254 }
255 unsigned int
256 OSSerialize::setCapacityIncrement(unsigned int increment)
257 {
258 	capacityIncrement = (increment)? increment : 256;
259 	return capacityIncrement;
260 }
261 
262 unsigned int
263 OSSerialize::ensureCapacity(unsigned int newCapacity)
264 {
265 	char *newData;
266 
267 	if (newCapacity <= capacity) {
268 		return capacity;
269 	}
270 
271 	if (round_page_overflow(newCapacity, &newCapacity)) {
272 		return capacity;
273 	}
274 
275 	kern_return_t rc = kmem_realloc(kernel_map,
276 	    (vm_offset_t)data,
277 	    capacity,
278 	    (vm_offset_t *)&newData,
279 	    newCapacity,
280 	    VM_KERN_MEMORY_IOKIT);
281 	if (!rc) {
282 		OSCONTAINER_ACCUMSIZE(newCapacity);
283 
284 		// kmem realloc does not free the old address range
285 		kmem_free(kernel_map, (vm_offset_t)data, capacity);
286 		OSCONTAINER_ACCUMSIZE(-((size_t)capacity));
287 
288 		// kmem realloc does not zero out the new memory
289 		// and this could end up going to user land
290 		bzero(&newData[capacity], newCapacity - capacity);
291 
292 		data = newData;
293 		capacity = newCapacity;
294 	}
295 
296 	return capacity;
297 }
298 
299 void
300 OSSerialize::free()
301 {
302 	if (data) {
303 		kmem_free(kernel_map, (vm_offset_t)data, capacity);
304 		OSCONTAINER_ACCUMSIZE( -((size_t)capacity));
305 	}
306 	super::free();
307 }
308 
309 
310 OSDefineMetaClassAndStructors(OSSerializer, OSObject)
311 
312 OSSharedPtr<OSSerializer>
313 OSSerializer::forTarget( void * target,
314     OSSerializerCallback callback, void * ref )
315 {
316 	OSSharedPtr<OSSerializer> thing = OSMakeShared<OSSerializer>();
317 
318 	if (thing && !thing->init()) {
319 		thing.reset();
320 	}
321 
322 	if (thing) {
323 		thing->target   = target;
324 		thing->ref      = ref;
325 		thing->callback = callback;
326 	}
327 	return thing;
328 }
329 
330 bool
331 OSSerializer::callbackToBlock(void * target __unused, void * ref,
332     OSSerialize * serializer)
333 {
334 	return ((OSSerializerBlock)ref)(serializer);
335 }
336 
337 OSSharedPtr<OSSerializer>
338 OSSerializer::withBlock(
339 	OSSerializerBlock callback)
340 {
341 	OSSharedPtr<OSSerializer> serializer;
342 	OSSerializerBlock block;
343 
344 	block = Block_copy(callback);
345 	if (!block) {
346 		return NULL;
347 	}
348 
349 	serializer = (OSSerializer::forTarget(NULL, &OSSerializer::callbackToBlock, block));
350 
351 	if (!serializer) {
352 		Block_release(block);
353 	}
354 
355 	return serializer;
356 }
357 
358 void
359 OSSerializer::free(void)
360 {
361 	if (callback == &callbackToBlock) {
362 		Block_release(ref);
363 	}
364 
365 	super::free();
366 }
367 
368 bool
369 OSSerializer::serialize( OSSerialize * s ) const
370 {
371 	return (*callback)(target, ref, s);
372 }
373