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 27 // --------------------------------------------------------------------------- 28 namespace android { 29 30 template <typename T> class Flattenable; 31 template <typename T> class LightFlattenable; 32 class IBinder; 33 class IPCThreadState; 34 class ProcessState; 35 class String8; 36 class TextOutput; 37 38 struct flat_binder_object; // defined in support_p/binder_module.h 39 40 class Parcel { 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 const size_t* objects() const; 85 size_t objectsCount() const; 86 87 status_t errorCheck() const; 88 void setError(status_t err); 89 90 status_t write(const void* data, size_t len); 91 void* writeInplace(size_t len); 92 status_t writeUnpadded(const void* data, size_t len); 93 status_t writeInt32(int32_t val); 94 status_t writeInt64(int64_t val); 95 status_t writeFloat(float val); 96 status_t writeDouble(double val); 97 status_t writeIntPtr(intptr_t val); 98 status_t writeCString(const char* str); 99 status_t writeString8(const String8& str); 100 status_t writeString16(const String16& str); 101 status_t writeString16(const char16_t* str, size_t len); 102 status_t writeStrongBinder(const sp<IBinder>& val); 103 status_t writeWeakBinder(const wp<IBinder>& val); 104 status_t writeInt32Array(size_t len, const int32_t *val); 105 status_t writeByteArray(size_t len, const uint8_t *val); 106 107 template<typename T> 108 status_t write(const Flattenable<T>& val); 109 110 template<typename T> 111 status_t write(const LightFlattenable<T>& val); 112 113 114 // Place a native_handle into the parcel (the native_handle's file- 115 // descriptors are dup'ed, so it is safe to delete the native_handle 116 // when this function returns). 117 // Doesn't take ownership of the native_handle. 118 status_t writeNativeHandle(const native_handle* handle); 119 120 // Place a file descriptor into the parcel. The given fd must remain 121 // valid for the lifetime of the parcel. 122 // The Parcel does not take ownership of the given fd unless you ask it to. 123 status_t writeFileDescriptor(int fd, bool takeOwnership = false); 124 125 // Place a file descriptor into the parcel. A dup of the fd is made, which 126 // will be closed once the parcel is destroyed. 127 status_t writeDupFileDescriptor(int fd); 128 129 // Writes a blob to the parcel. 130 // If the blob is small, then it is stored in-place, otherwise it is 131 // transferred by way of an anonymous shared memory region. 132 // The caller should call release() on the blob after writing its contents. 133 status_t writeBlob(size_t len, WritableBlob* outBlob); 134 135 status_t writeObject(const flat_binder_object& val, bool nullMetaData); 136 137 // Like Parcel.java's writeNoException(). Just writes a zero int32. 138 // Currently the native implementation doesn't do any of the StrictMode 139 // stack gathering and serialization that the Java implementation does. 140 status_t writeNoException(); 141 142 void remove(size_t start, size_t amt); 143 144 status_t read(void* outData, size_t len) const; 145 const void* readInplace(size_t len) const; 146 int32_t readInt32() const; 147 status_t readInt32(int32_t *pArg) const; 148 int64_t readInt64() const; 149 status_t readInt64(int64_t *pArg) const; 150 float readFloat() const; 151 status_t readFloat(float *pArg) const; 152 double readDouble() const; 153 status_t readDouble(double *pArg) const; 154 intptr_t readIntPtr() const; 155 status_t readIntPtr(intptr_t *pArg) const; 156 157 const char* readCString() const; 158 String8 readString8() const; 159 String16 readString16() const; 160 const char16_t* readString16Inplace(size_t* outLen) const; 161 sp<IBinder> readStrongBinder() const; 162 wp<IBinder> readWeakBinder() const; 163 164 template<typename T> 165 status_t read(Flattenable<T>& val) const; 166 167 template<typename T> 168 status_t read(LightFlattenable<T>& val) const; 169 170 // Like Parcel.java's readExceptionCode(). Reads the first int32 171 // off of a Parcel's header, returning 0 or the negative error 172 // code on exceptions, but also deals with skipping over rich 173 // response headers. Callers should use this to read & parse the 174 // response headers rather than doing it by hand. 175 int32_t readExceptionCode() const; 176 177 // Retrieve native_handle from the parcel. This returns a copy of the 178 // parcel's native_handle (the caller takes ownership). The caller 179 // must free the native_handle with native_handle_close() and 180 // native_handle_delete(). 181 native_handle* readNativeHandle() const; 182 183 184 // Retrieve a file descriptor from the parcel. This returns the raw fd 185 // in the parcel, which you do not own -- use dup() to get your own copy. 186 int readFileDescriptor() const; 187 188 // Reads a blob from the parcel. 189 // The caller should call release() on the blob after reading its contents. 190 status_t readBlob(size_t len, ReadableBlob* outBlob) const; 191 192 const flat_binder_object* readObject(bool nullMetaData) const; 193 194 // Explicitly close all file descriptors in the parcel. 195 void closeFileDescriptors(); 196 197 typedef void (*release_func)(Parcel* parcel, 198 const uint8_t* data, size_t dataSize, 199 const size_t* objects, size_t objectsSize, 200 void* cookie); 201 202 const uint8_t* ipcData() const; 203 size_t ipcDataSize() const; 204 const size_t* ipcObjects() const; 205 size_t ipcObjectsCount() const; 206 void ipcSetDataReference(const uint8_t* data, size_t dataSize, 207 const size_t* objects, size_t objectsCount, 208 release_func relFunc, void* relCookie); 209 210 void print(TextOutput& to, uint32_t flags = 0) const; 211 212 private: 213 Parcel(const Parcel& o); 214 Parcel& operator=(const Parcel& o); 215 216 status_t finishWrite(size_t len); 217 void releaseObjects(); 218 void acquireObjects(); 219 status_t growData(size_t len); 220 status_t restartWrite(size_t desired); 221 status_t continueWrite(size_t desired); 222 void freeDataNoInit(); 223 void initState(); 224 void scanForFds() const; 225 226 template<class T> 227 status_t readAligned(T *pArg) const; 228 229 template<class T> T readAligned() const; 230 231 template<class T> 232 status_t writeAligned(T val); 233 234 status_t mError; 235 uint8_t* mData; 236 size_t mDataSize; 237 size_t mDataCapacity; 238 mutable size_t mDataPos; 239 size_t* mObjects; 240 size_t mObjectsSize; 241 size_t mObjectsCapacity; 242 mutable size_t mNextObjectHint; 243 244 mutable bool mFdsKnown; 245 mutable bool mHasFds; 246 bool mAllowFds; 247 248 release_func mOwner; 249 void* mOwnerCookie; 250 251 class Blob { 252 public: 253 Blob(); 254 ~Blob(); 255 256 void release(); 257 inline size_t size() const { return mSize; } 258 259 protected: 260 void init(bool mapped, void* data, size_t size); 261 void clear(); 262 263 bool mMapped; 264 void* mData; 265 size_t mSize; 266 }; 267 268 class FlattenableHelperInterface { 269 protected: 270 ~FlattenableHelperInterface() { } 271 public: 272 virtual size_t getFlattenedSize() const = 0; 273 virtual size_t getFdCount() const = 0; 274 virtual status_t flatten(void* buffer, size_t size, int* fds, size_t count) const = 0; 275 virtual status_t unflatten(void const* buffer, size_t size, int const* fds, size_t count) = 0; 276 }; 277 278 template<typename T> 279 class FlattenableHelper : public FlattenableHelperInterface { 280 friend class Parcel; 281 const Flattenable<T>& val; 282 explicit FlattenableHelper(const Flattenable<T>& val) : val(val) { } 283 284 public: 285 virtual size_t getFlattenedSize() const { 286 return val.getFlattenedSize(); 287 } 288 virtual size_t getFdCount() const { 289 return val.getFdCount(); 290 } 291 virtual status_t flatten(void* buffer, size_t size, int* fds, size_t count) const { 292 return val.flatten(buffer, size, fds, count); 293 } 294 virtual status_t unflatten(void const* buffer, size_t size, int const* fds, size_t count) { 295 return const_cast<Flattenable<T>&>(val).unflatten(buffer, size, fds, count); 296 } 297 }; 298 status_t write(const FlattenableHelperInterface& val); 299 status_t read(FlattenableHelperInterface& val) const; 300 301 public: 302 class ReadableBlob : public Blob { 303 friend class Parcel; 304 public: 305 inline const void* data() const { return mData; } 306 }; 307 308 class WritableBlob : public Blob { 309 friend class Parcel; 310 public: 311 inline void* data() { return mData; } 312 }; 313 }; 314 315 // --------------------------------------------------------------------------- 316 317 template<typename T> 318 status_t Parcel::write(const Flattenable<T>& val) { 319 const FlattenableHelper<T> helper(val); 320 return write(helper); 321 } 322 323 template<typename T> 324 status_t Parcel::write(const LightFlattenable<T>& val) { 325 size_t size(val.getFlattenedSize()); 326 if (!val.isFixedSize()) { 327 status_t err = writeInt32(size); 328 if (err != NO_ERROR) { 329 return err; 330 } 331 } 332 if (size) { 333 void* buffer = writeInplace(size); 334 if (buffer == NULL) 335 return NO_MEMORY; 336 return val.flatten(buffer, size); 337 } 338 return NO_ERROR; 339 } 340 341 template<typename T> 342 status_t Parcel::read(Flattenable<T>& val) const { 343 FlattenableHelper<T> helper(val); 344 return read(helper); 345 } 346 347 template<typename T> 348 status_t Parcel::read(LightFlattenable<T>& val) const { 349 size_t size; 350 if (val.isFixedSize()) { 351 size = val.getFlattenedSize(); 352 } else { 353 int32_t s; 354 status_t err = readInt32(&s); 355 if (err != NO_ERROR) { 356 return err; 357 } 358 size = s; 359 } 360 if (size) { 361 void const* buffer = readInplace(size); 362 return buffer == NULL ? NO_MEMORY : 363 val.unflatten(buffer, size); 364 } 365 return NO_ERROR; 366 } 367 368 // --------------------------------------------------------------------------- 369 370 inline TextOutput& operator<<(TextOutput& to, const Parcel& parcel) 371 { 372 parcel.print(to); 373 return to; 374 } 375 376 // --------------------------------------------------------------------------- 377 378 // Generic acquire and release of objects. 379 void acquire_object(const sp<ProcessState>& proc, 380 const flat_binder_object& obj, const void* who); 381 void release_object(const sp<ProcessState>& proc, 382 const flat_binder_object& obj, const void* who); 383 384 void flatten_binder(const sp<ProcessState>& proc, 385 const sp<IBinder>& binder, flat_binder_object* out); 386 void flatten_binder(const sp<ProcessState>& proc, 387 const wp<IBinder>& binder, flat_binder_object* out); 388 status_t unflatten_binder(const sp<ProcessState>& proc, 389 const flat_binder_object& flat, sp<IBinder>* out); 390 status_t unflatten_binder(const sp<ProcessState>& proc, 391 const flat_binder_object& flat, wp<IBinder>* out); 392 393 }; // namespace android 394 395 // --------------------------------------------------------------------------- 396 397 #endif // ANDROID_PARCEL_H 398
