Parcel.h revision 75c5de42b759bdcfa7c0e6103fb959c28d686116
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 <vector> 21 22#include <cutils/native_handle.h> 23#include <utils/Errors.h> 24#include <utils/RefBase.h> 25#include <utils/String16.h> 26#include <utils/Vector.h> 27#include <utils/Flattenable.h> 28#include <linux/binder.h> 29 30#include <binder/IInterface.h> 31 32// --------------------------------------------------------------------------- 33namespace android { 34 35template <typename T> class Flattenable; 36template <typename T> class LightFlattenable; 37class IBinder; 38class IPCThreadState; 39class ProcessState; 40class String8; 41class TextOutput; 42 43class Parcel { 44 friend class IPCThreadState; 45public: 46 class ReadableBlob; 47 class WritableBlob; 48 49 Parcel(); 50 ~Parcel(); 51 52 const uint8_t* data() const; 53 size_t dataSize() const; 54 size_t dataAvail() const; 55 size_t dataPosition() const; 56 size_t dataCapacity() const; 57 58 status_t setDataSize(size_t size); 59 void setDataPosition(size_t pos) const; 60 status_t setDataCapacity(size_t size); 61 62 status_t setData(const uint8_t* buffer, size_t len); 63 64 status_t appendFrom(const Parcel *parcel, 65 size_t start, size_t len); 66 67 bool allowFds() const; 68 bool pushAllowFds(bool allowFds); 69 void restoreAllowFds(bool lastValue); 70 71 bool hasFileDescriptors() const; 72 73 // Writes the RPC header. 74 status_t writeInterfaceToken(const String16& interface); 75 76 // Parses the RPC header, returning true if the interface name 77 // in the header matches the expected interface from the caller. 78 // 79 // Additionally, enforceInterface does part of the work of 80 // propagating the StrictMode policy mask, populating the current 81 // IPCThreadState, which as an optimization may optionally be 82 // passed in. 83 bool enforceInterface(const String16& interface, 84 IPCThreadState* threadState = NULL) const; 85 bool checkInterface(IBinder*) const; 86 87 void freeData(); 88 89private: 90 const binder_size_t* objects() const; 91 92public: 93 size_t objectsCount() const; 94 95 status_t errorCheck() const; 96 void setError(status_t err); 97 98 status_t write(const void* data, size_t len); 99 void* writeInplace(size_t len); 100 status_t writeUnpadded(const void* data, size_t len); 101 status_t writeInt32(int32_t val); 102 status_t writeUint32(uint32_t val); 103 status_t writeInt64(int64_t val); 104 status_t writeUint64(uint64_t val); 105 status_t writeFloat(float val); 106 status_t writeDouble(double val); 107 status_t writeCString(const char* str); 108 status_t writeString8(const String8& str); 109 status_t writeString16(const String16& str); 110 status_t writeString16(const char16_t* str, size_t len); 111 status_t writeStrongBinder(const sp<IBinder>& val); 112 status_t writeWeakBinder(const wp<IBinder>& val); 113 status_t writeInt32Array(size_t len, const int32_t *val); 114 status_t writeByteArray(size_t len, const uint8_t *val); 115 status_t writeBool(bool val); 116 status_t writeChar(char16_t val); 117 status_t writeByte(int8_t val); 118 119 status_t writeByteVector(const std::vector<int8_t>& val); 120 status_t writeInt32Vector(const std::vector<int32_t>& val); 121 status_t writeInt64Vector(const std::vector<int64_t>& val); 122 status_t writeFloatVector(const std::vector<float>& val); 123 status_t writeDoubleVector(const std::vector<double>& val); 124 status_t writeBoolVector(const std::vector<bool>& val); 125 status_t writeCharVector(const std::vector<char16_t>& val); 126 status_t writeString16Vector(const std::vector<String16>& val); 127 128 template<typename T> 129 status_t write(const Flattenable<T>& val); 130 131 template<typename T> 132 status_t write(const LightFlattenable<T>& val); 133 134 135 // Place a native_handle into the parcel (the native_handle's file- 136 // descriptors are dup'ed, so it is safe to delete the native_handle 137 // when this function returns). 138 // Doesn't take ownership of the native_handle. 139 status_t writeNativeHandle(const native_handle* handle); 140 141 // Place a file descriptor into the parcel. The given fd must remain 142 // valid for the lifetime of the parcel. 143 // The Parcel does not take ownership of the given fd unless you ask it to. 144 status_t writeFileDescriptor(int fd, bool takeOwnership = false); 145 146 // Place a file descriptor into the parcel. A dup of the fd is made, which 147 // will be closed once the parcel is destroyed. 148 status_t writeDupFileDescriptor(int fd); 149 150 // Writes a blob to the parcel. 151 // If the blob is small, then it is stored in-place, otherwise it is 152 // transferred by way of an anonymous shared memory region. Prefer sending 153 // immutable blobs if possible since they may be subsequently transferred between 154 // processes without further copying whereas mutable blobs always need to be copied. 155 // The caller should call release() on the blob after writing its contents. 156 status_t writeBlob(size_t len, bool mutableCopy, WritableBlob* outBlob); 157 158 // Write an existing immutable blob file descriptor to the parcel. 159 // This allows the client to send the same blob to multiple processes 160 // as long as it keeps a dup of the blob file descriptor handy for later. 161 status_t writeDupImmutableBlobFileDescriptor(int fd); 162 163 status_t writeObject(const flat_binder_object& val, bool nullMetaData); 164 165 // Like Parcel.java's writeNoException(). Just writes a zero int32. 166 // Currently the native implementation doesn't do any of the StrictMode 167 // stack gathering and serialization that the Java implementation does. 168 status_t writeNoException(); 169 170 void remove(size_t start, size_t amt); 171 172 status_t read(void* outData, size_t len) const; 173 const void* readInplace(size_t len) const; 174 int32_t readInt32() const; 175 status_t readInt32(int32_t *pArg) const; 176 uint32_t readUint32() const; 177 status_t readUint32(uint32_t *pArg) const; 178 int64_t readInt64() const; 179 status_t readInt64(int64_t *pArg) const; 180 uint64_t readUint64() const; 181 status_t readUint64(uint64_t *pArg) const; 182 float readFloat() const; 183 status_t readFloat(float *pArg) const; 184 double readDouble() const; 185 status_t readDouble(double *pArg) const; 186 intptr_t readIntPtr() const; 187 status_t readIntPtr(intptr_t *pArg) const; 188 bool readBool() const; 189 status_t readBool(bool *pArg) const; 190 char16_t readChar() const; 191 status_t readChar(char16_t *pArg) const; 192 int8_t readByte() const; 193 status_t readByte(int8_t *pArg) const; 194 195 const char* readCString() const; 196 String8 readString8() const; 197 String16 readString16() const; 198 status_t readString16(String16* pArg) const; 199 const char16_t* readString16Inplace(size_t* outLen) const; 200 sp<IBinder> readStrongBinder() const; 201 status_t readStrongBinder(sp<IBinder>* val) const; 202 wp<IBinder> readWeakBinder() const; 203 204 template<typename T> 205 status_t readStrongBinder(sp<T>* val) const; 206 207 status_t readByteVector(std::vector<int8_t>* val) const; 208 status_t readInt32Vector(std::vector<int32_t>* val) const; 209 status_t readInt64Vector(std::vector<int64_t>* val) const; 210 status_t readFloatVector(std::vector<float>* val) const; 211 status_t readDoubleVector(std::vector<double>* val) const; 212 status_t readBoolVector(std::vector<bool>* val) const; 213 status_t readCharVector(std::vector<char16_t>* val) const; 214 status_t readString16Vector(std::vector<String16>* val) const; 215 216 template<typename T> 217 status_t read(Flattenable<T>& val) const; 218 219 template<typename T> 220 status_t read(LightFlattenable<T>& val) const; 221 222 // Like Parcel.java's readExceptionCode(). Reads the first int32 223 // off of a Parcel's header, returning 0 or the negative error 224 // code on exceptions, but also deals with skipping over rich 225 // response headers. Callers should use this to read & parse the 226 // response headers rather than doing it by hand. 227 int32_t readExceptionCode() const; 228 229 // Retrieve native_handle from the parcel. This returns a copy of the 230 // parcel's native_handle (the caller takes ownership). The caller 231 // must free the native_handle with native_handle_close() and 232 // native_handle_delete(). 233 native_handle* readNativeHandle() const; 234 235 236 // Retrieve a file descriptor from the parcel. This returns the raw fd 237 // in the parcel, which you do not own -- use dup() to get your own copy. 238 int readFileDescriptor() const; 239 240 // Reads a blob from the parcel. 241 // The caller should call release() on the blob after reading its contents. 242 status_t readBlob(size_t len, ReadableBlob* outBlob) const; 243 244 const flat_binder_object* readObject(bool nullMetaData) const; 245 246 // Explicitly close all file descriptors in the parcel. 247 void closeFileDescriptors(); 248 249 // Debugging: get metrics on current allocations. 250 static size_t getGlobalAllocSize(); 251 static size_t getGlobalAllocCount(); 252 253private: 254 typedef void (*release_func)(Parcel* parcel, 255 const uint8_t* data, size_t dataSize, 256 const binder_size_t* objects, size_t objectsSize, 257 void* cookie); 258 259 uintptr_t ipcData() const; 260 size_t ipcDataSize() const; 261 uintptr_t ipcObjects() const; 262 size_t ipcObjectsCount() const; 263 void ipcSetDataReference(const uint8_t* data, size_t dataSize, 264 const binder_size_t* objects, size_t objectsCount, 265 release_func relFunc, void* relCookie); 266 267public: 268 void print(TextOutput& to, uint32_t flags = 0) const; 269 270private: 271 Parcel(const Parcel& o); 272 Parcel& operator=(const Parcel& o); 273 274 status_t finishWrite(size_t len); 275 void releaseObjects(); 276 void acquireObjects(); 277 status_t growData(size_t len); 278 status_t restartWrite(size_t desired); 279 status_t continueWrite(size_t desired); 280 status_t writePointer(uintptr_t val); 281 status_t readPointer(uintptr_t *pArg) const; 282 uintptr_t readPointer() const; 283 void freeDataNoInit(); 284 void initState(); 285 void scanForFds() const; 286 287 template<class T> 288 status_t readAligned(T *pArg) const; 289 290 template<class T> T readAligned() const; 291 292 template<class T> 293 status_t writeAligned(T val); 294 295 status_t mError; 296 uint8_t* mData; 297 size_t mDataSize; 298 size_t mDataCapacity; 299 mutable size_t mDataPos; 300 binder_size_t* mObjects; 301 size_t mObjectsSize; 302 size_t mObjectsCapacity; 303 mutable size_t mNextObjectHint; 304 305 mutable bool mFdsKnown; 306 mutable bool mHasFds; 307 bool mAllowFds; 308 309 release_func mOwner; 310 void* mOwnerCookie; 311 312 class Blob { 313 public: 314 Blob(); 315 ~Blob(); 316 317 void clear(); 318 void release(); 319 inline size_t size() const { return mSize; } 320 inline int fd() const { return mFd; }; 321 inline bool isMutable() const { return mMutable; } 322 323 protected: 324 void init(int fd, void* data, size_t size, bool isMutable); 325 326 int mFd; // owned by parcel so not closed when released 327 void* mData; 328 size_t mSize; 329 bool mMutable; 330 }; 331 332 class FlattenableHelperInterface { 333 protected: 334 ~FlattenableHelperInterface() { } 335 public: 336 virtual size_t getFlattenedSize() const = 0; 337 virtual size_t getFdCount() const = 0; 338 virtual status_t flatten(void* buffer, size_t size, int* fds, size_t count) const = 0; 339 virtual status_t unflatten(void const* buffer, size_t size, int const* fds, size_t count) = 0; 340 }; 341 342 template<typename T> 343 class FlattenableHelper : public FlattenableHelperInterface { 344 friend class Parcel; 345 const Flattenable<T>& val; 346 explicit FlattenableHelper(const Flattenable<T>& val) : val(val) { } 347 348 public: 349 virtual size_t getFlattenedSize() const { 350 return val.getFlattenedSize(); 351 } 352 virtual size_t getFdCount() const { 353 return val.getFdCount(); 354 } 355 virtual status_t flatten(void* buffer, size_t size, int* fds, size_t count) const { 356 return val.flatten(buffer, size, fds, count); 357 } 358 virtual status_t unflatten(void const* buffer, size_t size, int const* fds, size_t count) { 359 return const_cast<Flattenable<T>&>(val).unflatten(buffer, size, fds, count); 360 } 361 }; 362 status_t write(const FlattenableHelperInterface& val); 363 status_t read(FlattenableHelperInterface& val) const; 364 365public: 366 class ReadableBlob : public Blob { 367 friend class Parcel; 368 public: 369 inline const void* data() const { return mData; } 370 inline void* mutableData() { return isMutable() ? mData : NULL; } 371 }; 372 373 class WritableBlob : public Blob { 374 friend class Parcel; 375 public: 376 inline void* data() { return mData; } 377 }; 378 379private: 380 size_t mOpenAshmemSize; 381 382public: 383 // TODO: Remove once ABI can be changed. 384 size_t getBlobAshmemSize() const; 385 size_t getOpenAshmemSize() const; 386}; 387 388// --------------------------------------------------------------------------- 389 390template<typename T> 391status_t Parcel::write(const Flattenable<T>& val) { 392 const FlattenableHelper<T> helper(val); 393 return write(helper); 394} 395 396template<typename T> 397status_t Parcel::write(const LightFlattenable<T>& val) { 398 size_t size(val.getFlattenedSize()); 399 if (!val.isFixedSize()) { 400 status_t err = writeInt32(size); 401 if (err != NO_ERROR) { 402 return err; 403 } 404 } 405 if (size) { 406 void* buffer = writeInplace(size); 407 if (buffer == NULL) 408 return NO_MEMORY; 409 return val.flatten(buffer, size); 410 } 411 return NO_ERROR; 412} 413 414template<typename T> 415status_t Parcel::read(Flattenable<T>& val) const { 416 FlattenableHelper<T> helper(val); 417 return read(helper); 418} 419 420template<typename T> 421status_t Parcel::read(LightFlattenable<T>& val) const { 422 size_t size; 423 if (val.isFixedSize()) { 424 size = val.getFlattenedSize(); 425 } else { 426 int32_t s; 427 status_t err = readInt32(&s); 428 if (err != NO_ERROR) { 429 return err; 430 } 431 size = s; 432 } 433 if (size) { 434 void const* buffer = readInplace(size); 435 return buffer == NULL ? NO_MEMORY : 436 val.unflatten(buffer, size); 437 } 438 return NO_ERROR; 439} 440 441template<typename T> 442status_t Parcel::readStrongBinder(sp<T>* val) const { 443 sp<IBinder> tmp; 444 status_t ret = readStrongBinder(&tmp); 445 446 if (ret == OK) { 447 *val = interface_cast<T>(tmp); 448 449 if (val->get() == nullptr) { 450 return UNKNOWN_ERROR; 451 } 452 } 453 454 return ret; 455} 456 457// --------------------------------------------------------------------------- 458 459inline TextOutput& operator<<(TextOutput& to, const Parcel& parcel) 460{ 461 parcel.print(to); 462 return to; 463} 464 465// --------------------------------------------------------------------------- 466 467// Generic acquire and release of objects. 468void acquire_object(const sp<ProcessState>& proc, 469 const flat_binder_object& obj, const void* who); 470void release_object(const sp<ProcessState>& proc, 471 const flat_binder_object& obj, const void* who); 472 473void flatten_binder(const sp<ProcessState>& proc, 474 const sp<IBinder>& binder, flat_binder_object* out); 475void flatten_binder(const sp<ProcessState>& proc, 476 const wp<IBinder>& binder, flat_binder_object* out); 477status_t unflatten_binder(const sp<ProcessState>& proc, 478 const flat_binder_object& flat, sp<IBinder>* out); 479status_t unflatten_binder(const sp<ProcessState>& proc, 480 const flat_binder_object& flat, wp<IBinder>* out); 481 482}; // namespace android 483 484// --------------------------------------------------------------------------- 485 486#endif // ANDROID_PARCEL_H 487