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