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