1 /*
2 * Copyright (C) 2005 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #ifndef ANDROID_PARCEL_H
18 #define ANDROID_PARCEL_H
19
20 #include <cutils/native_handle.h>
21 #include <utils/Errors.h>
22 #include <utils/RefBase.h>
23 #include <utils/String16.h>
24 #include <utils/Vector.h>
25 #include <utils/Flattenable.h>
26 #include <linux/binder.h>
27
28 // ---------------------------------------------------------------------------
29 namespace android {
30
31 template <typename T> class Flattenable;
32 template <typename T> class LightFlattenable;
33 class IBinder;
34 class IPCThreadState;
35 class ProcessState;
36 class String8;
37 class TextOutput;
38
39 class Parcel {
40 friend class IPCThreadState;
41 public:
42 class ReadableBlob;
43 class WritableBlob;
44
45 Parcel();
46 ~Parcel();
47
48 const uint8_t* data() const;
49 size_t dataSize() const;
50 size_t dataAvail() const;
51 size_t dataPosition() const;
52 size_t dataCapacity() const;
53
54 status_t setDataSize(size_t size);
55 void setDataPosition(size_t pos) const;
56 status_t setDataCapacity(size_t size);
57
58 status_t setData(const uint8_t* buffer, size_t len);
59
60 status_t appendFrom(const Parcel *parcel,
61 size_t start, size_t len);
62
63 bool pushAllowFds(bool allowFds);
64 void restoreAllowFds(bool lastValue);
65
66 bool hasFileDescriptors() const;
67
68 // Writes the RPC header.
69 status_t writeInterfaceToken(const String16& interface);
70
71 // Parses the RPC header, returning true if the interface name
72 // in the header matches the expected interface from the caller.
73 //
74 // Additionally, enforceInterface does part of the work of
75 // propagating the StrictMode policy mask, populating the current
76 // IPCThreadState, which as an optimization may optionally be
77 // passed in.
78 bool enforceInterface(const String16& interface,
79 IPCThreadState* threadState = NULL) const;
80 bool checkInterface(IBinder*) const;
81
82 void freeData();
83
84 private:
85 const binder_size_t* objects() const;
86
87 public:
88 size_t objectsCount() const;
89
90 status_t errorCheck() const;
91 void setError(status_t err);
92
93 status_t write(const void* data, size_t len);
94 void* writeInplace(size_t len);
95 status_t writeUnpadded(const void* data, size_t len);
96 status_t writeInt32(int32_t val);
97 status_t writeInt64(int64_t val);
98 status_t writeFloat(float val);
99 status_t writeDouble(double val);
100 status_t writeCString(const char* str);
101 status_t writeString8(const String8& str);
102 status_t writeString16(const String16& str);
103 status_t writeString16(const char16_t* str, size_t len);
104 status_t writeStrongBinder(const sp<IBinder>& val);
105 status_t writeWeakBinder(const wp<IBinder>& val);
106 status_t writeInt32Array(size_t len, const int32_t *val);
107 status_t writeByteArray(size_t len, const uint8_t *val);
108
109 template<typename T>
110 status_t write(const Flattenable<T>& val);
111
112 template<typename T>
113 status_t write(const LightFlattenable<T>& val);
114
115
116 // Place a native_handle into the parcel (the native_handle's file-
117 // descriptors are dup'ed, so it is safe to delete the native_handle
118 // when this function returns).
119 // Doesn't take ownership of the native_handle.
120 status_t writeNativeHandle(const native_handle* handle);
121
122 // Place a file descriptor into the parcel. The given fd must remain
123 // valid for the lifetime of the parcel.
124 // The Parcel does not take ownership of the given fd unless you ask it to.
125 status_t writeFileDescriptor(int fd, bool takeOwnership = false);
126
127 // Place a file descriptor into the parcel. A dup of the fd is made, which
128 // will be closed once the parcel is destroyed.
129 status_t writeDupFileDescriptor(int fd);
130
131 // Writes a raw fd and optional comm channel fd to the parcel as a ParcelFileDescriptor.
132 // A dup's of the fds are made, which will be closed once the parcel is destroyed.
133 // Null values are passed as -1.
134 status_t writeParcelFileDescriptor(int fd, int commChannel = -1);
135
136 // Writes a blob to the parcel.
137 // If the blob is small, then it is stored in-place, otherwise it is
138 // transferred by way of an anonymous shared memory region.
139 // The caller should call release() on the blob after writing its contents.
140 status_t writeBlob(size_t len, WritableBlob* outBlob);
141
142 status_t writeObject(const flat_binder_object& val, bool nullMetaData);
143
144 // Like Parcel.java's writeNoException(). Just writes a zero int32.
145 // Currently the native implementation doesn't do any of the StrictMode
146 // stack gathering and serialization that the Java implementation does.
147 status_t writeNoException();
148
149 void remove(size_t start, size_t amt);
150
151 status_t read(void* outData, size_t len) const;
152 const void* readInplace(size_t len) const;
153 int32_t readInt32() const;
154 status_t readInt32(int32_t *pArg) const;
155 int64_t readInt64() const;
156 status_t readInt64(int64_t *pArg) const;
157 float readFloat() const;
158 status_t readFloat(float *pArg) const;
159 double readDouble() const;
160 status_t readDouble(double *pArg) const;
161 intptr_t readIntPtr() const;
162 status_t readIntPtr(intptr_t *pArg) const;
163
164 const char* readCString() const;
165 String8 readString8() const;
166 String16 readString16() const;
167 const char16_t* readString16Inplace(size_t* outLen) const;
168 sp<IBinder> readStrongBinder() const;
169 wp<IBinder> readWeakBinder() const;
170
171 template<typename T>
172 status_t read(Flattenable<T>& val) const;
173
174 template<typename T>
175 status_t read(LightFlattenable<T>& val) const;
176
177 // Like Parcel.java's readExceptionCode(). Reads the first int32
178 // off of a Parcel's header, returning 0 or the negative error
179 // code on exceptions, but also deals with skipping over rich
180 // response headers. Callers should use this to read & parse the
181 // response headers rather than doing it by hand.
182 int32_t readExceptionCode() const;
183
184 // Retrieve native_handle from the parcel. This returns a copy of the
185 // parcel's native_handle (the caller takes ownership). The caller
186 // must free the native_handle with native_handle_close() and
187 // native_handle_delete().
188 native_handle* readNativeHandle() const;
189
190
191 // Retrieve a file descriptor from the parcel. This returns the raw fd
192 // in the parcel, which you do not own -- use dup() to get your own copy.
193 int readFileDescriptor() const;
194
195 // Reads a ParcelFileDescriptor from the parcel. Returns the raw fd as
196 // the result, and the optional comm channel fd in outCommChannel.
197 // Null values are returned as -1.
198 int readParcelFileDescriptor(int& outCommChannel) const;
199
200 // Reads a blob from the parcel.
201 // The caller should call release() on the blob after reading its contents.
202 status_t readBlob(size_t len, ReadableBlob* outBlob) const;
203
204 const flat_binder_object* readObject(bool nullMetaData) const;
205
206 // Explicitly close all file descriptors in the parcel.
207 void closeFileDescriptors();
208
209 private:
210 typedef void (*release_func)(Parcel* parcel,
211 const uint8_t* data, size_t dataSize,
212 const binder_size_t* objects, size_t objectsSize,
213 void* cookie);
214
215 uintptr_t ipcData() const;
216 size_t ipcDataSize() const;
217 uintptr_t ipcObjects() const;
218 size_t ipcObjectsCount() const;
219 void ipcSetDataReference(const uint8_t* data, size_t dataSize,
220 const binder_size_t* objects, size_t objectsCount,
221 release_func relFunc, void* relCookie);
222
223 public:
224 void print(TextOutput& to, uint32_t flags = 0) const;
225
226 private:
227 Parcel(const Parcel& o);
228 Parcel& operator=(const Parcel& o);
229
230 status_t finishWrite(size_t len);
231 void releaseObjects();
232 void acquireObjects();
233 status_t growData(size_t len);
234 status_t restartWrite(size_t desired);
235 status_t continueWrite(size_t desired);
236 status_t writePointer(uintptr_t val);
237 status_t readPointer(uintptr_t *pArg) const;
238 uintptr_t readPointer() const;
239 void freeDataNoInit();
240 void initState();
241 void scanForFds() const;
242
243 template<class T>
244 status_t readAligned(T *pArg) const;
245
246 template<class T> T readAligned() const;
247
248 template<class T>
249 status_t writeAligned(T val);
250
251 status_t mError;
252 uint8_t* mData;
253 size_t mDataSize;
254 size_t mDataCapacity;
255 mutable size_t mDataPos;
256 binder_size_t* mObjects;
257 size_t mObjectsSize;
258 size_t mObjectsCapacity;
259 mutable size_t mNextObjectHint;
260
261 mutable bool mFdsKnown;
262 mutable bool mHasFds;
263 bool mAllowFds;
264
265 release_func mOwner;
266 void* mOwnerCookie;
267
268 class Blob {
269 public:
270 Blob();
271 ~Blob();
272
273 void release();
size()274 inline size_t size() const { return mSize; }
275
276 protected:
277 void init(bool mapped, void* data, size_t size);
278 void clear();
279
280 bool mMapped;
281 void* mData;
282 size_t mSize;
283 };
284
285 class FlattenableHelperInterface {
286 protected:
~FlattenableHelperInterface()287 ~FlattenableHelperInterface() { }
288 public:
289 virtual size_t getFlattenedSize() const = 0;
290 virtual size_t getFdCount() const = 0;
291 virtual status_t flatten(void* buffer, size_t size, int* fds, size_t count) const = 0;
292 virtual status_t unflatten(void const* buffer, size_t size, int const* fds, size_t count) = 0;
293 };
294
295 template<typename T>
296 class FlattenableHelper : public FlattenableHelperInterface {
297 friend class Parcel;
298 const Flattenable<T>& val;
FlattenableHelper(const Flattenable<T> & val)299 explicit FlattenableHelper(const Flattenable<T>& val) : val(val) { }
300
301 public:
getFlattenedSize()302 virtual size_t getFlattenedSize() const {
303 return val.getFlattenedSize();
304 }
getFdCount()305 virtual size_t getFdCount() const {
306 return val.getFdCount();
307 }
flatten(void * buffer,size_t size,int * fds,size_t count)308 virtual status_t flatten(void* buffer, size_t size, int* fds, size_t count) const {
309 return val.flatten(buffer, size, fds, count);
310 }
unflatten(void const * buffer,size_t size,int const * fds,size_t count)311 virtual status_t unflatten(void const* buffer, size_t size, int const* fds, size_t count) {
312 return const_cast<Flattenable<T>&>(val).unflatten(buffer, size, fds, count);
313 }
314 };
315 status_t write(const FlattenableHelperInterface& val);
316 status_t read(FlattenableHelperInterface& val) const;
317
318 public:
319 class ReadableBlob : public Blob {
320 friend class Parcel;
321 public:
data()322 inline const void* data() const { return mData; }
323 };
324
325 class WritableBlob : public Blob {
326 friend class Parcel;
327 public:
data()328 inline void* data() { return mData; }
329 };
330 };
331
332 // ---------------------------------------------------------------------------
333
334 template<typename T>
write(const Flattenable<T> & val)335 status_t Parcel::write(const Flattenable<T>& val) {
336 const FlattenableHelper<T> helper(val);
337 return write(helper);
338 }
339
340 template<typename T>
write(const LightFlattenable<T> & val)341 status_t Parcel::write(const LightFlattenable<T>& val) {
342 size_t size(val.getFlattenedSize());
343 if (!val.isFixedSize()) {
344 status_t err = writeInt32(size);
345 if (err != NO_ERROR) {
346 return err;
347 }
348 }
349 if (size) {
350 void* buffer = writeInplace(size);
351 if (buffer == NULL)
352 return NO_MEMORY;
353 return val.flatten(buffer, size);
354 }
355 return NO_ERROR;
356 }
357
358 template<typename T>
read(Flattenable<T> & val)359 status_t Parcel::read(Flattenable<T>& val) const {
360 FlattenableHelper<T> helper(val);
361 return read(helper);
362 }
363
364 template<typename T>
read(LightFlattenable<T> & val)365 status_t Parcel::read(LightFlattenable<T>& val) const {
366 size_t size;
367 if (val.isFixedSize()) {
368 size = val.getFlattenedSize();
369 } else {
370 int32_t s;
371 status_t err = readInt32(&s);
372 if (err != NO_ERROR) {
373 return err;
374 }
375 size = s;
376 }
377 if (size) {
378 void const* buffer = readInplace(size);
379 return buffer == NULL ? NO_MEMORY :
380 val.unflatten(buffer, size);
381 }
382 return NO_ERROR;
383 }
384
385 // ---------------------------------------------------------------------------
386
387 inline TextOutput& operator<<(TextOutput& to, const Parcel& parcel)
388 {
389 parcel.print(to);
390 return to;
391 }
392
393 // ---------------------------------------------------------------------------
394
395 // Generic acquire and release of objects.
396 void acquire_object(const sp<ProcessState>& proc,
397 const flat_binder_object& obj, const void* who);
398 void release_object(const sp<ProcessState>& proc,
399 const flat_binder_object& obj, const void* who);
400
401 void flatten_binder(const sp<ProcessState>& proc,
402 const sp<IBinder>& binder, flat_binder_object* out);
403 void flatten_binder(const sp<ProcessState>& proc,
404 const wp<IBinder>& binder, flat_binder_object* out);
405 status_t unflatten_binder(const sp<ProcessState>& proc,
406 const flat_binder_object& flat, sp<IBinder>* out);
407 status_t unflatten_binder(const sp<ProcessState>& proc,
408 const flat_binder_object& flat, wp<IBinder>* out);
409
410 }; // namespace android
411
412 // ---------------------------------------------------------------------------
413
414 #endif // ANDROID_PARCEL_H
415