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 allowFds() const; 64 bool pushAllowFds(bool allowFds); 65 void restoreAllowFds(bool lastValue); 66 67 bool hasFileDescriptors() const; 68 69 // Writes the RPC header. 70 status_t writeInterfaceToken(const String16& interface); 71 72 // Parses the RPC header, returning true if the interface name 73 // in the header matches the expected interface from the caller. 74 // 75 // Additionally, enforceInterface does part of the work of 76 // propagating the StrictMode policy mask, populating the current 77 // IPCThreadState, which as an optimization may optionally be 78 // passed in. 79 bool enforceInterface(const String16& interface, 80 IPCThreadState* threadState = NULL) const; 81 bool checkInterface(IBinder*) const; 82 83 void freeData(); 84 85 private: 86 const binder_size_t* objects() const; 87 88 public: 89 size_t objectsCount() const; 90 91 status_t errorCheck() const; 92 void setError(status_t err); 93 94 status_t write(const void* data, size_t len); 95 void* writeInplace(size_t len); 96 status_t writeUnpadded(const void* data, size_t len); 97 status_t writeInt32(int32_t val); 98 status_t writeUint32(uint32_t val); 99 status_t writeInt64(int64_t val); 100 status_t writeUint64(uint64_t val); 101 status_t writeFloat(float val); 102 status_t writeDouble(double val); 103 status_t writeCString(const char* str); 104 status_t writeString8(const String8& str); 105 status_t writeString16(const String16& str); 106 status_t writeString16(const char16_t* str, size_t len); 107 status_t writeStrongBinder(const sp<IBinder>& val); 108 status_t writeWeakBinder(const wp<IBinder>& val); 109 status_t writeInt32Array(size_t len, const int32_t *val); 110 status_t writeByteArray(size_t len, const uint8_t *val); 111 112 template<typename T> 113 status_t write(const Flattenable<T>& val); 114 115 template<typename T> 116 status_t write(const LightFlattenable<T>& val); 117 118 119 // Place a native_handle into the parcel (the native_handle's file- 120 // descriptors are dup'ed, so it is safe to delete the native_handle 121 // when this function returns). 122 // Doesn't take ownership of the native_handle. 123 status_t writeNativeHandle(const native_handle* handle); 124 125 // Place a file descriptor into the parcel. The given fd must remain 126 // valid for the lifetime of the parcel. 127 // The Parcel does not take ownership of the given fd unless you ask it to. 128 status_t writeFileDescriptor(int fd, bool takeOwnership = false); 129 130 // Place a file descriptor into the parcel. A dup of the fd is made, which 131 // will be closed once the parcel is destroyed. 132 status_t writeDupFileDescriptor(int fd); 133 134 // Writes a blob to the parcel. 135 // If the blob is small, then it is stored in-place, otherwise it is 136 // transferred by way of an anonymous shared memory region. Prefer sending 137 // immutable blobs if possible since they may be subsequently transferred between 138 // processes without further copying whereas mutable blobs always need to be copied. 139 // The caller should call release() on the blob after writing its contents. 140 status_t writeBlob(size_t len, bool mutableCopy, WritableBlob* outBlob); 141 142 // Write an existing immutable blob file descriptor to the parcel. 143 // This allows the client to send the same blob to multiple processes 144 // as long as it keeps a dup of the blob file descriptor handy for later. 145 status_t writeDupImmutableBlobFileDescriptor(int fd); 146 147 status_t writeObject(const flat_binder_object& val, bool nullMetaData); 148 149 // Like Parcel.java's writeNoException(). Just writes a zero int32. 150 // Currently the native implementation doesn't do any of the StrictMode 151 // stack gathering and serialization that the Java implementation does. 152 status_t writeNoException(); 153 154 void remove(size_t start, size_t amt); 155 156 status_t read(void* outData, size_t len) const; 157 const void* readInplace(size_t len) const; 158 int32_t readInt32() const; 159 status_t readInt32(int32_t *pArg) const; 160 uint32_t readUint32() const; 161 status_t readUint32(uint32_t *pArg) const; 162 int64_t readInt64() const; 163 status_t readInt64(int64_t *pArg) const; 164 uint64_t readUint64() const; 165 status_t readUint64(uint64_t *pArg) const; 166 float readFloat() const; 167 status_t readFloat(float *pArg) const; 168 double readDouble() const; 169 status_t readDouble(double *pArg) const; 170 intptr_t readIntPtr() const; 171 status_t readIntPtr(intptr_t *pArg) const; 172 173 const char* readCString() const; 174 String8 readString8() const; 175 String16 readString16() const; 176 const char16_t* readString16Inplace(size_t* outLen) const; 177 sp<IBinder> readStrongBinder() const; 178 wp<IBinder> readWeakBinder() const; 179 180 template<typename T> 181 status_t read(Flattenable<T>& val) const; 182 183 template<typename T> 184 status_t read(LightFlattenable<T>& val) const; 185 186 // Like Parcel.java's readExceptionCode(). Reads the first int32 187 // off of a Parcel's header, returning 0 or the negative error 188 // code on exceptions, but also deals with skipping over rich 189 // response headers. Callers should use this to read & parse the 190 // response headers rather than doing it by hand. 191 int32_t readExceptionCode() const; 192 193 // Retrieve native_handle from the parcel. This returns a copy of the 194 // parcel's native_handle (the caller takes ownership). The caller 195 // must free the native_handle with native_handle_close() and 196 // native_handle_delete(). 197 native_handle* readNativeHandle() const; 198 199 200 // Retrieve a file descriptor from the parcel. This returns the raw fd 201 // in the parcel, which you do not own -- use dup() to get your own copy. 202 int readFileDescriptor() const; 203 204 // Reads a blob from the parcel. 205 // The caller should call release() on the blob after reading its contents. 206 status_t readBlob(size_t len, ReadableBlob* outBlob) const; 207 208 const flat_binder_object* readObject(bool nullMetaData) const; 209 210 // Explicitly close all file descriptors in the parcel. 211 void closeFileDescriptors(); 212 213 // Debugging: get metrics on current allocations. 214 static size_t getGlobalAllocSize(); 215 static size_t getGlobalAllocCount(); 216 217 private: 218 typedef void (*release_func)(Parcel* parcel, 219 const uint8_t* data, size_t dataSize, 220 const binder_size_t* objects, size_t objectsSize, 221 void* cookie); 222 223 uintptr_t ipcData() const; 224 size_t ipcDataSize() const; 225 uintptr_t ipcObjects() const; 226 size_t ipcObjectsCount() const; 227 void ipcSetDataReference(const uint8_t* data, size_t dataSize, 228 const binder_size_t* objects, size_t objectsCount, 229 release_func relFunc, void* relCookie); 230 231 public: 232 void print(TextOutput& to, uint32_t flags = 0) const; 233 234 private: 235 Parcel(const Parcel& o); 236 Parcel& operator=(const Parcel& o); 237 238 status_t finishWrite(size_t len); 239 void releaseObjects(); 240 void acquireObjects(); 241 status_t growData(size_t len); 242 status_t restartWrite(size_t desired); 243 status_t continueWrite(size_t desired); 244 status_t writePointer(uintptr_t val); 245 status_t readPointer(uintptr_t *pArg) const; 246 uintptr_t readPointer() const; 247 void freeDataNoInit(); 248 void initState(); 249 void scanForFds() const; 250 251 template<class T> 252 status_t readAligned(T *pArg) const; 253 254 template<class T> T readAligned() const; 255 256 template<class T> 257 status_t writeAligned(T val); 258 259 status_t mError; 260 uint8_t* mData; 261 size_t mDataSize; 262 size_t mDataCapacity; 263 mutable size_t mDataPos; 264 binder_size_t* mObjects; 265 size_t mObjectsSize; 266 size_t mObjectsCapacity; 267 mutable size_t mNextObjectHint; 268 269 mutable bool mFdsKnown; 270 mutable bool mHasFds; 271 bool mAllowFds; 272 273 release_func mOwner; 274 void* mOwnerCookie; 275 276 class Blob { 277 public: 278 Blob(); 279 ~Blob(); 280 281 void clear(); 282 void release(); 283 inline size_t size() const { return mSize; } 284 inline int fd() const { return mFd; }; 285 inline bool isMutable() const { return mMutable; } 286 287 protected: 288 void init(int fd, void* data, size_t size, bool isMutable); 289 290 int mFd; // owned by parcel so not closed when released 291 void* mData; 292 size_t mSize; 293 bool mMutable; 294 }; 295 296 class FlattenableHelperInterface { 297 protected: 298 ~FlattenableHelperInterface() { } 299 public: 300 virtual size_t getFlattenedSize() const = 0; 301 virtual size_t getFdCount() const = 0; 302 virtual status_t flatten(void* buffer, size_t size, int* fds, size_t count) const = 0; 303 virtual status_t unflatten(void const* buffer, size_t size, int const* fds, size_t count) = 0; 304 }; 305 306 template<typename T> 307 class FlattenableHelper : public FlattenableHelperInterface { 308 friend class Parcel; 309 const Flattenable<T>& val; 310 explicit FlattenableHelper(const Flattenable<T>& val) : val(val) { } 311 312 public: 313 virtual size_t getFlattenedSize() const { 314 return val.getFlattenedSize(); 315 } 316 virtual size_t getFdCount() const { 317 return val.getFdCount(); 318 } 319 virtual status_t flatten(void* buffer, size_t size, int* fds, size_t count) const { 320 return val.flatten(buffer, size, fds, count); 321 } 322 virtual status_t unflatten(void const* buffer, size_t size, int const* fds, size_t count) { 323 return const_cast<Flattenable<T>&>(val).unflatten(buffer, size, fds, count); 324 } 325 }; 326 status_t write(const FlattenableHelperInterface& val); 327 status_t read(FlattenableHelperInterface& val) const; 328 329 public: 330 class ReadableBlob : public Blob { 331 friend class Parcel; 332 public: 333 inline const void* data() const { return mData; } 334 inline void* mutableData() { return isMutable() ? mData : NULL; } 335 }; 336 337 class WritableBlob : public Blob { 338 friend class Parcel; 339 public: 340 inline void* data() { return mData; } 341 }; 342 343 private: 344 size_t mBlobAshmemSize; 345 346 public: 347 size_t getBlobAshmemSize() const; 348 }; 349 350 // --------------------------------------------------------------------------- 351 352 template<typename T> 353 status_t Parcel::write(const Flattenable<T>& val) { 354 const FlattenableHelper<T> helper(val); 355 return write(helper); 356 } 357 358 template<typename T> 359 status_t Parcel::write(const LightFlattenable<T>& val) { 360 size_t size(val.getFlattenedSize()); 361 if (!val.isFixedSize()) { 362 status_t err = writeInt32(size); 363 if (err != NO_ERROR) { 364 return err; 365 } 366 } 367 if (size) { 368 void* buffer = writeInplace(size); 369 if (buffer == NULL) 370 return NO_MEMORY; 371 return val.flatten(buffer, size); 372 } 373 return NO_ERROR; 374 } 375 376 template<typename T> 377 status_t Parcel::read(Flattenable<T>& val) const { 378 FlattenableHelper<T> helper(val); 379 return read(helper); 380 } 381 382 template<typename T> 383 status_t Parcel::read(LightFlattenable<T>& val) const { 384 size_t size; 385 if (val.isFixedSize()) { 386 size = val.getFlattenedSize(); 387 } else { 388 int32_t s; 389 status_t err = readInt32(&s); 390 if (err != NO_ERROR) { 391 return err; 392 } 393 size = s; 394 } 395 if (size) { 396 void const* buffer = readInplace(size); 397 return buffer == NULL ? NO_MEMORY : 398 val.unflatten(buffer, size); 399 } 400 return NO_ERROR; 401 } 402 403 // --------------------------------------------------------------------------- 404 405 inline TextOutput& operator<<(TextOutput& to, const Parcel& parcel) 406 { 407 parcel.print(to); 408 return to; 409 } 410 411 // --------------------------------------------------------------------------- 412 413 // Generic acquire and release of objects. 414 void acquire_object(const sp<ProcessState>& proc, 415 const flat_binder_object& obj, const void* who); 416 void release_object(const sp<ProcessState>& proc, 417 const flat_binder_object& obj, const void* who); 418 419 void flatten_binder(const sp<ProcessState>& proc, 420 const sp<IBinder>& binder, flat_binder_object* out); 421 void flatten_binder(const sp<ProcessState>& proc, 422 const wp<IBinder>& binder, flat_binder_object* out); 423 status_t unflatten_binder(const sp<ProcessState>& proc, 424 const flat_binder_object& flat, sp<IBinder>* out); 425 status_t unflatten_binder(const sp<ProcessState>& proc, 426 const flat_binder_object& flat, wp<IBinder>* out); 427 428 }; // namespace android 429 430 // --------------------------------------------------------------------------- 431 432 #endif // ANDROID_PARCEL_H 433
