Parcel.h revision 0dd1a5d2f4e69c5df233fa9468191c03dc9b639f
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 <base/unique_fd.h> 23#include <cutils/native_handle.h> 24#include <utils/Errors.h> 25#include <utils/RefBase.h> 26#include <utils/String16.h> 27#include <utils/Vector.h> 28#include <utils/Flattenable.h> 29#include <linux/binder.h> 30 31#include <binder/IInterface.h> 32 33// --------------------------------------------------------------------------- 34namespace android { 35 36template <typename T> class Flattenable; 37template <typename T> class LightFlattenable; 38class IBinder; 39class IPCThreadState; 40class ProcessState; 41class String8; 42class TextOutput; 43 44class Parcel { 45 friend class IPCThreadState; 46public: 47 class ReadableBlob; 48 class WritableBlob; 49 50 Parcel(); 51 ~Parcel(); 52 53 const uint8_t* data() const; 54 size_t dataSize() const; 55 size_t dataAvail() const; 56 size_t dataPosition() const; 57 size_t dataCapacity() const; 58 59 status_t setDataSize(size_t size); 60 void setDataPosition(size_t pos) const; 61 status_t setDataCapacity(size_t size); 62 63 status_t setData(const uint8_t* buffer, size_t len); 64 65 status_t appendFrom(const Parcel *parcel, 66 size_t start, size_t len); 67 68 bool allowFds() const; 69 bool pushAllowFds(bool allowFds); 70 void restoreAllowFds(bool lastValue); 71 72 bool hasFileDescriptors() const; 73 74 // Writes the RPC header. 75 status_t writeInterfaceToken(const String16& interface); 76 77 // Parses the RPC header, returning true if the interface name 78 // in the header matches the expected interface from the caller. 79 // 80 // Additionally, enforceInterface does part of the work of 81 // propagating the StrictMode policy mask, populating the current 82 // IPCThreadState, which as an optimization may optionally be 83 // passed in. 84 bool enforceInterface(const String16& interface, 85 IPCThreadState* threadState = NULL) const; 86 bool checkInterface(IBinder*) const; 87 88 void freeData(); 89 90private: 91 const binder_size_t* objects() const; 92 93public: 94 size_t objectsCount() const; 95 96 status_t errorCheck() const; 97 void setError(status_t err); 98 99 status_t write(const void* data, size_t len); 100 void* writeInplace(size_t len); 101 status_t writeUnpadded(const void* data, size_t len); 102 status_t writeInt32(int32_t val); 103 status_t writeUint32(uint32_t val); 104 status_t writeInt64(int64_t val); 105 status_t writeUint64(uint64_t val); 106 status_t writeFloat(float val); 107 status_t writeDouble(double val); 108 status_t writeCString(const char* str); 109 status_t writeString8(const String8& str); 110 status_t writeString16(const String16& str); 111 status_t writeString16(const char16_t* str, size_t len); 112 status_t writeStrongBinder(const sp<IBinder>& val); 113 status_t writeWeakBinder(const wp<IBinder>& val); 114 status_t writeInt32Array(size_t len, const int32_t *val); 115 status_t writeByteArray(size_t len, const uint8_t *val); 116 status_t writeBool(bool val); 117 status_t writeChar(char16_t val); 118 status_t writeByte(int8_t val); 119 120 status_t writeByteVector(const std::vector<int8_t>& val); 121 status_t writeInt32Vector(const std::vector<int32_t>& val); 122 status_t writeInt64Vector(const std::vector<int64_t>& val); 123 status_t writeFloatVector(const std::vector<float>& val); 124 status_t writeDoubleVector(const std::vector<double>& val); 125 status_t writeBoolVector(const std::vector<bool>& val); 126 status_t writeCharVector(const std::vector<char16_t>& val); 127 status_t writeString16Vector(const std::vector<String16>& val); 128 129 status_t writeStrongBinderVector(const std::vector<sp<IBinder>>& val); 130 131 template<typename T> 132 status_t write(const Flattenable<T>& val); 133 134 template<typename T> 135 status_t write(const LightFlattenable<T>& val); 136 137 138 // Place a native_handle into the parcel (the native_handle's file- 139 // descriptors are dup'ed, so it is safe to delete the native_handle 140 // when this function returns). 141 // Doesn't take ownership of the native_handle. 142 status_t writeNativeHandle(const native_handle* handle); 143 144 // Place a file descriptor into the parcel. The given fd must remain 145 // valid for the lifetime of the parcel. 146 // The Parcel does not take ownership of the given fd unless you ask it to. 147 status_t writeFileDescriptor(int fd, bool takeOwnership = false); 148 149 // Place a file descriptor into the parcel. A dup of the fd is made, which 150 // will be closed once the parcel is destroyed. 151 status_t writeDupFileDescriptor(int fd); 152 153 // Place a file descriptor into the parcel. This will not affect the 154 // semantics of the smart file descriptor. A new descriptor will be 155 // created, and will be closed when the parcel is destroyed. 156 status_t writeUniqueFileDescriptor( 157 const android::base::unique_fd& fd); 158 159 // Place a vector of file desciptors into the parcel. Each descriptor is 160 // dup'd as in writeDupFileDescriptor 161 status_t writeUniqueFileDescriptorVector( 162 const std::vector<android::base::unique_fd>& val); 163 164 // Writes a blob to the parcel. 165 // If the blob is small, then it is stored in-place, otherwise it is 166 // transferred by way of an anonymous shared memory region. Prefer sending 167 // immutable blobs if possible since they may be subsequently transferred between 168 // processes without further copying whereas mutable blobs always need to be copied. 169 // The caller should call release() on the blob after writing its contents. 170 status_t writeBlob(size_t len, bool mutableCopy, WritableBlob* outBlob); 171 172 // Write an existing immutable blob file descriptor to the parcel. 173 // This allows the client to send the same blob to multiple processes 174 // as long as it keeps a dup of the blob file descriptor handy for later. 175 status_t writeDupImmutableBlobFileDescriptor(int fd); 176 177 status_t writeObject(const flat_binder_object& val, bool nullMetaData); 178 179 // Like Parcel.java's writeNoException(). Just writes a zero int32. 180 // Currently the native implementation doesn't do any of the StrictMode 181 // stack gathering and serialization that the Java implementation does. 182 status_t writeNoException(); 183 184 void remove(size_t start, size_t amt); 185 186 status_t read(void* outData, size_t len) const; 187 const void* readInplace(size_t len) const; 188 int32_t readInt32() const; 189 status_t readInt32(int32_t *pArg) const; 190 uint32_t readUint32() const; 191 status_t readUint32(uint32_t *pArg) const; 192 int64_t readInt64() const; 193 status_t readInt64(int64_t *pArg) const; 194 uint64_t readUint64() const; 195 status_t readUint64(uint64_t *pArg) const; 196 float readFloat() const; 197 status_t readFloat(float *pArg) const; 198 double readDouble() const; 199 status_t readDouble(double *pArg) const; 200 intptr_t readIntPtr() const; 201 status_t readIntPtr(intptr_t *pArg) const; 202 bool readBool() const; 203 status_t readBool(bool *pArg) const; 204 char16_t readChar() const; 205 status_t readChar(char16_t *pArg) const; 206 int8_t readByte() const; 207 status_t readByte(int8_t *pArg) const; 208 209 const char* readCString() const; 210 String8 readString8() const; 211 String16 readString16() const; 212 status_t readString16(String16* pArg) const; 213 const char16_t* readString16Inplace(size_t* outLen) const; 214 sp<IBinder> readStrongBinder() const; 215 status_t readStrongBinder(sp<IBinder>* val) const; 216 wp<IBinder> readWeakBinder() const; 217 218 template<typename T> 219 status_t readStrongBinder(sp<T>* val) const; 220 221 status_t readStrongBinderVector(std::vector<sp<IBinder>>* val) const; 222 223 status_t readByteVector(std::vector<int8_t>* val) const; 224 status_t readInt32Vector(std::vector<int32_t>* val) const; 225 status_t readInt64Vector(std::vector<int64_t>* val) const; 226 status_t readFloatVector(std::vector<float>* val) const; 227 status_t readDoubleVector(std::vector<double>* val) const; 228 status_t readBoolVector(std::vector<bool>* val) const; 229 status_t readCharVector(std::vector<char16_t>* val) const; 230 status_t readString16Vector(std::vector<String16>* val) const; 231 232 template<typename T> 233 status_t read(Flattenable<T>& val) const; 234 235 template<typename T> 236 status_t read(LightFlattenable<T>& val) const; 237 238 // Like Parcel.java's readExceptionCode(). Reads the first int32 239 // off of a Parcel's header, returning 0 or the negative error 240 // code on exceptions, but also deals with skipping over rich 241 // response headers. Callers should use this to read & parse the 242 // response headers rather than doing it by hand. 243 int32_t readExceptionCode() const; 244 245 // Retrieve native_handle from the parcel. This returns a copy of the 246 // parcel's native_handle (the caller takes ownership). The caller 247 // must free the native_handle with native_handle_close() and 248 // native_handle_delete(). 249 native_handle* readNativeHandle() const; 250 251 252 // Retrieve a file descriptor from the parcel. This returns the raw fd 253 // in the parcel, which you do not own -- use dup() to get your own copy. 254 int readFileDescriptor() const; 255 256 // Retrieve a smart file descriptor from the parcel. 257 status_t readUniqueFileDescriptor( 258 android::base::unique_fd* val) const; 259 260 261 // Retrieve a vector of smart file descriptors from the parcel. 262 status_t readUniqueFileDescriptorVector( 263 std::vector<android::base::unique_fd>* val) const; 264 265 // Reads a blob from the parcel. 266 // The caller should call release() on the blob after reading its contents. 267 status_t readBlob(size_t len, ReadableBlob* outBlob) const; 268 269 const flat_binder_object* readObject(bool nullMetaData) const; 270 271 // Explicitly close all file descriptors in the parcel. 272 void closeFileDescriptors(); 273 274 // Debugging: get metrics on current allocations. 275 static size_t getGlobalAllocSize(); 276 static size_t getGlobalAllocCount(); 277 278private: 279 typedef void (*release_func)(Parcel* parcel, 280 const uint8_t* data, size_t dataSize, 281 const binder_size_t* objects, size_t objectsSize, 282 void* cookie); 283 284 uintptr_t ipcData() const; 285 size_t ipcDataSize() const; 286 uintptr_t ipcObjects() const; 287 size_t ipcObjectsCount() const; 288 void ipcSetDataReference(const uint8_t* data, size_t dataSize, 289 const binder_size_t* objects, size_t objectsCount, 290 release_func relFunc, void* relCookie); 291 292public: 293 void print(TextOutput& to, uint32_t flags = 0) const; 294 295private: 296 Parcel(const Parcel& o); 297 Parcel& operator=(const Parcel& o); 298 299 status_t finishWrite(size_t len); 300 void releaseObjects(); 301 void acquireObjects(); 302 status_t growData(size_t len); 303 status_t restartWrite(size_t desired); 304 status_t continueWrite(size_t desired); 305 status_t writePointer(uintptr_t val); 306 status_t readPointer(uintptr_t *pArg) const; 307 uintptr_t readPointer() const; 308 void freeDataNoInit(); 309 void initState(); 310 void scanForFds() const; 311 312 template<class T> 313 status_t readAligned(T *pArg) const; 314 315 template<class T> T readAligned() const; 316 317 template<class T> 318 status_t writeAligned(T val); 319 320 status_t mError; 321 uint8_t* mData; 322 size_t mDataSize; 323 size_t mDataCapacity; 324 mutable size_t mDataPos; 325 binder_size_t* mObjects; 326 size_t mObjectsSize; 327 size_t mObjectsCapacity; 328 mutable size_t mNextObjectHint; 329 330 mutable bool mFdsKnown; 331 mutable bool mHasFds; 332 bool mAllowFds; 333 334 release_func mOwner; 335 void* mOwnerCookie; 336 337 class Blob { 338 public: 339 Blob(); 340 ~Blob(); 341 342 void clear(); 343 void release(); 344 inline size_t size() const { return mSize; } 345 inline int fd() const { return mFd; }; 346 inline bool isMutable() const { return mMutable; } 347 348 protected: 349 void init(int fd, void* data, size_t size, bool isMutable); 350 351 int mFd; // owned by parcel so not closed when released 352 void* mData; 353 size_t mSize; 354 bool mMutable; 355 }; 356 357 class FlattenableHelperInterface { 358 protected: 359 ~FlattenableHelperInterface() { } 360 public: 361 virtual size_t getFlattenedSize() const = 0; 362 virtual size_t getFdCount() const = 0; 363 virtual status_t flatten(void* buffer, size_t size, int* fds, size_t count) const = 0; 364 virtual status_t unflatten(void const* buffer, size_t size, int const* fds, size_t count) = 0; 365 }; 366 367 template<typename T> 368 class FlattenableHelper : public FlattenableHelperInterface { 369 friend class Parcel; 370 const Flattenable<T>& val; 371 explicit FlattenableHelper(const Flattenable<T>& val) : val(val) { } 372 373 public: 374 virtual size_t getFlattenedSize() const { 375 return val.getFlattenedSize(); 376 } 377 virtual size_t getFdCount() const { 378 return val.getFdCount(); 379 } 380 virtual status_t flatten(void* buffer, size_t size, int* fds, size_t count) const { 381 return val.flatten(buffer, size, fds, count); 382 } 383 virtual status_t unflatten(void const* buffer, size_t size, int const* fds, size_t count) { 384 return const_cast<Flattenable<T>&>(val).unflatten(buffer, size, fds, count); 385 } 386 }; 387 status_t write(const FlattenableHelperInterface& val); 388 status_t read(FlattenableHelperInterface& val) const; 389 390public: 391 class ReadableBlob : public Blob { 392 friend class Parcel; 393 public: 394 inline const void* data() const { return mData; } 395 inline void* mutableData() { return isMutable() ? mData : NULL; } 396 }; 397 398 class WritableBlob : public Blob { 399 friend class Parcel; 400 public: 401 inline void* data() { return mData; } 402 }; 403 404private: 405 size_t mOpenAshmemSize; 406 407public: 408 // TODO: Remove once ABI can be changed. 409 size_t getBlobAshmemSize() const; 410 size_t getOpenAshmemSize() const; 411}; 412 413// --------------------------------------------------------------------------- 414 415template<typename T> 416status_t Parcel::write(const Flattenable<T>& val) { 417 const FlattenableHelper<T> helper(val); 418 return write(helper); 419} 420 421template<typename T> 422status_t Parcel::write(const LightFlattenable<T>& val) { 423 size_t size(val.getFlattenedSize()); 424 if (!val.isFixedSize()) { 425 status_t err = writeInt32(size); 426 if (err != NO_ERROR) { 427 return err; 428 } 429 } 430 if (size) { 431 void* buffer = writeInplace(size); 432 if (buffer == NULL) 433 return NO_MEMORY; 434 return val.flatten(buffer, size); 435 } 436 return NO_ERROR; 437} 438 439template<typename T> 440status_t Parcel::read(Flattenable<T>& val) const { 441 FlattenableHelper<T> helper(val); 442 return read(helper); 443} 444 445template<typename T> 446status_t Parcel::read(LightFlattenable<T>& val) const { 447 size_t size; 448 if (val.isFixedSize()) { 449 size = val.getFlattenedSize(); 450 } else { 451 int32_t s; 452 status_t err = readInt32(&s); 453 if (err != NO_ERROR) { 454 return err; 455 } 456 size = s; 457 } 458 if (size) { 459 void const* buffer = readInplace(size); 460 return buffer == NULL ? NO_MEMORY : 461 val.unflatten(buffer, size); 462 } 463 return NO_ERROR; 464} 465 466template<typename T> 467status_t Parcel::readStrongBinder(sp<T>* val) const { 468 sp<IBinder> tmp; 469 status_t ret = readStrongBinder(&tmp); 470 471 if (ret == OK) { 472 *val = interface_cast<T>(tmp); 473 474 if (val->get() == nullptr) { 475 return UNKNOWN_ERROR; 476 } 477 } 478 479 return ret; 480} 481 482// --------------------------------------------------------------------------- 483 484inline TextOutput& operator<<(TextOutput& to, const Parcel& parcel) 485{ 486 parcel.print(to); 487 return to; 488} 489 490// --------------------------------------------------------------------------- 491 492// Generic acquire and release of objects. 493void acquire_object(const sp<ProcessState>& proc, 494 const flat_binder_object& obj, const void* who); 495void release_object(const sp<ProcessState>& proc, 496 const flat_binder_object& obj, const void* who); 497 498void flatten_binder(const sp<ProcessState>& proc, 499 const sp<IBinder>& binder, flat_binder_object* out); 500void flatten_binder(const sp<ProcessState>& proc, 501 const wp<IBinder>& binder, flat_binder_object* out); 502status_t unflatten_binder(const sp<ProcessState>& proc, 503 const flat_binder_object& flat, sp<IBinder>* out); 504status_t unflatten_binder(const sp<ProcessState>& proc, 505 const flat_binder_object& flat, wp<IBinder>* out); 506 507}; // namespace android 508 509// --------------------------------------------------------------------------- 510 511#endif // ANDROID_PARCEL_H 512