Parcel.h revision 03d1eb6bf90bcd0a04b176988478d2e939d3fba0
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 status_t writeStrongBinderVector(const std::vector<sp<IBinder>>& val); 129 130 template<typename T> 131 status_t write(const Flattenable<T>& val); 132 133 template<typename T> 134 status_t write(const LightFlattenable<T>& val); 135 136 137 // Place a native_handle into the parcel (the native_handle's file- 138 // descriptors are dup'ed, so it is safe to delete the native_handle 139 // when this function returns). 140 // Doesn't take ownership of the native_handle. 141 status_t writeNativeHandle(const native_handle* handle); 142 143 // Place a file descriptor into the parcel. The given fd must remain 144 // valid for the lifetime of the parcel. 145 // The Parcel does not take ownership of the given fd unless you ask it to. 146 status_t writeFileDescriptor(int fd, bool takeOwnership = false); 147 148 // Place a file descriptor into the parcel. A dup of the fd is made, which 149 // will be closed once the parcel is destroyed. 150 status_t writeDupFileDescriptor(int fd); 151 152 // Writes a blob to the parcel. 153 // If the blob is small, then it is stored in-place, otherwise it is 154 // transferred by way of an anonymous shared memory region. Prefer sending 155 // immutable blobs if possible since they may be subsequently transferred between 156 // processes without further copying whereas mutable blobs always need to be copied. 157 // The caller should call release() on the blob after writing its contents. 158 status_t writeBlob(size_t len, bool mutableCopy, WritableBlob* outBlob); 159 160 // Write an existing immutable blob file descriptor to the parcel. 161 // This allows the client to send the same blob to multiple processes 162 // as long as it keeps a dup of the blob file descriptor handy for later. 163 status_t writeDupImmutableBlobFileDescriptor(int fd); 164 165 status_t writeObject(const flat_binder_object& val, bool nullMetaData); 166 167 // Like Parcel.java's writeNoException(). Just writes a zero int32. 168 // Currently the native implementation doesn't do any of the StrictMode 169 // stack gathering and serialization that the Java implementation does. 170 status_t writeNoException(); 171 172 void remove(size_t start, size_t amt); 173 174 status_t read(void* outData, size_t len) const; 175 const void* readInplace(size_t len) const; 176 int32_t readInt32() const; 177 status_t readInt32(int32_t *pArg) const; 178 uint32_t readUint32() const; 179 status_t readUint32(uint32_t *pArg) const; 180 int64_t readInt64() const; 181 status_t readInt64(int64_t *pArg) const; 182 uint64_t readUint64() const; 183 status_t readUint64(uint64_t *pArg) const; 184 float readFloat() const; 185 status_t readFloat(float *pArg) const; 186 double readDouble() const; 187 status_t readDouble(double *pArg) const; 188 intptr_t readIntPtr() const; 189 status_t readIntPtr(intptr_t *pArg) const; 190 bool readBool() const; 191 status_t readBool(bool *pArg) const; 192 char16_t readChar() const; 193 status_t readChar(char16_t *pArg) const; 194 int8_t readByte() const; 195 status_t readByte(int8_t *pArg) const; 196 197 const char* readCString() const; 198 String8 readString8() const; 199 String16 readString16() const; 200 status_t readString16(String16* pArg) const; 201 const char16_t* readString16Inplace(size_t* outLen) const; 202 sp<IBinder> readStrongBinder() const; 203 status_t readStrongBinder(sp<IBinder>* val) const; 204 wp<IBinder> readWeakBinder() const; 205 206 template<typename T> 207 status_t readStrongBinder(sp<T>* val) const; 208 209 status_t readStrongBinderVector(std::vector<sp<IBinder>>* val) const; 210 211 status_t readByteVector(std::vector<int8_t>* val) const; 212 status_t readInt32Vector(std::vector<int32_t>* val) const; 213 status_t readInt64Vector(std::vector<int64_t>* val) const; 214 status_t readFloatVector(std::vector<float>* val) const; 215 status_t readDoubleVector(std::vector<double>* val) const; 216 status_t readBoolVector(std::vector<bool>* val) const; 217 status_t readCharVector(std::vector<char16_t>* val) const; 218 status_t readString16Vector(std::vector<String16>* val) const; 219 220 template<typename T> 221 status_t read(Flattenable<T>& val) const; 222 223 template<typename T> 224 status_t read(LightFlattenable<T>& val) const; 225 226 // Like Parcel.java's readExceptionCode(). Reads the first int32 227 // off of a Parcel's header, returning 0 or the negative error 228 // code on exceptions, but also deals with skipping over rich 229 // response headers. Callers should use this to read & parse the 230 // response headers rather than doing it by hand. 231 int32_t readExceptionCode() const; 232 233 // Retrieve native_handle from the parcel. This returns a copy of the 234 // parcel's native_handle (the caller takes ownership). The caller 235 // must free the native_handle with native_handle_close() and 236 // native_handle_delete(). 237 native_handle* readNativeHandle() const; 238 239 240 // Retrieve a file descriptor from the parcel. This returns the raw fd 241 // in the parcel, which you do not own -- use dup() to get your own copy. 242 int readFileDescriptor() const; 243 244 // Reads a blob from the parcel. 245 // The caller should call release() on the blob after reading its contents. 246 status_t readBlob(size_t len, ReadableBlob* outBlob) const; 247 248 const flat_binder_object* readObject(bool nullMetaData) const; 249 250 // Explicitly close all file descriptors in the parcel. 251 void closeFileDescriptors(); 252 253 // Debugging: get metrics on current allocations. 254 static size_t getGlobalAllocSize(); 255 static size_t getGlobalAllocCount(); 256 257private: 258 typedef void (*release_func)(Parcel* parcel, 259 const uint8_t* data, size_t dataSize, 260 const binder_size_t* objects, size_t objectsSize, 261 void* cookie); 262 263 uintptr_t ipcData() const; 264 size_t ipcDataSize() const; 265 uintptr_t ipcObjects() const; 266 size_t ipcObjectsCount() const; 267 void ipcSetDataReference(const uint8_t* data, size_t dataSize, 268 const binder_size_t* objects, size_t objectsCount, 269 release_func relFunc, void* relCookie); 270 271public: 272 void print(TextOutput& to, uint32_t flags = 0) const; 273 274private: 275 Parcel(const Parcel& o); 276 Parcel& operator=(const Parcel& o); 277 278 status_t finishWrite(size_t len); 279 void releaseObjects(); 280 void acquireObjects(); 281 status_t growData(size_t len); 282 status_t restartWrite(size_t desired); 283 status_t continueWrite(size_t desired); 284 status_t writePointer(uintptr_t val); 285 status_t readPointer(uintptr_t *pArg) const; 286 uintptr_t readPointer() const; 287 void freeDataNoInit(); 288 void initState(); 289 void scanForFds() const; 290 291 template<class T> 292 status_t readAligned(T *pArg) const; 293 294 template<class T> T readAligned() const; 295 296 template<class T> 297 status_t writeAligned(T val); 298 299 template<typename T, typename U> 300 status_t unsafeReadTypedVector(std::vector<T>* val, 301 status_t(Parcel::*read_func)(U*) const) const; 302 template<typename T> 303 status_t readTypedVector(std::vector<T>* val, 304 status_t(Parcel::*read_func)(T*) const) const; 305 template<typename T, typename U> 306 status_t unsafeWriteTypedVector(const std::vector<T>& val, 307 status_t(Parcel::*write_func)(U)); 308 template<typename T> 309 status_t writeTypedVector(const std::vector<T>& val, 310 status_t(Parcel::*write_func)(const T&)); 311 template<typename T> 312 status_t writeTypedVector(const std::vector<T>& val, 313 status_t(Parcel::*write_func)(T)); 314 315 status_t mError; 316 uint8_t* mData; 317 size_t mDataSize; 318 size_t mDataCapacity; 319 mutable size_t mDataPos; 320 binder_size_t* mObjects; 321 size_t mObjectsSize; 322 size_t mObjectsCapacity; 323 mutable size_t mNextObjectHint; 324 325 mutable bool mFdsKnown; 326 mutable bool mHasFds; 327 bool mAllowFds; 328 329 release_func mOwner; 330 void* mOwnerCookie; 331 332 class Blob { 333 public: 334 Blob(); 335 ~Blob(); 336 337 void clear(); 338 void release(); 339 inline size_t size() const { return mSize; } 340 inline int fd() const { return mFd; }; 341 inline bool isMutable() const { return mMutable; } 342 343 protected: 344 void init(int fd, void* data, size_t size, bool isMutable); 345 346 int mFd; // owned by parcel so not closed when released 347 void* mData; 348 size_t mSize; 349 bool mMutable; 350 }; 351 352 class FlattenableHelperInterface { 353 protected: 354 ~FlattenableHelperInterface() { } 355 public: 356 virtual size_t getFlattenedSize() const = 0; 357 virtual size_t getFdCount() const = 0; 358 virtual status_t flatten(void* buffer, size_t size, int* fds, size_t count) const = 0; 359 virtual status_t unflatten(void const* buffer, size_t size, int const* fds, size_t count) = 0; 360 }; 361 362 template<typename T> 363 class FlattenableHelper : public FlattenableHelperInterface { 364 friend class Parcel; 365 const Flattenable<T>& val; 366 explicit FlattenableHelper(const Flattenable<T>& val) : val(val) { } 367 368 public: 369 virtual size_t getFlattenedSize() const { 370 return val.getFlattenedSize(); 371 } 372 virtual size_t getFdCount() const { 373 return val.getFdCount(); 374 } 375 virtual status_t flatten(void* buffer, size_t size, int* fds, size_t count) const { 376 return val.flatten(buffer, size, fds, count); 377 } 378 virtual status_t unflatten(void const* buffer, size_t size, int const* fds, size_t count) { 379 return const_cast<Flattenable<T>&>(val).unflatten(buffer, size, fds, count); 380 } 381 }; 382 status_t write(const FlattenableHelperInterface& val); 383 status_t read(FlattenableHelperInterface& val) const; 384 385public: 386 class ReadableBlob : public Blob { 387 friend class Parcel; 388 public: 389 inline const void* data() const { return mData; } 390 inline void* mutableData() { return isMutable() ? mData : NULL; } 391 }; 392 393 class WritableBlob : public Blob { 394 friend class Parcel; 395 public: 396 inline void* data() { return mData; } 397 }; 398 399private: 400 size_t mBlobAshmemSize; 401 402public: 403 size_t getBlobAshmemSize() const; 404}; 405 406// --------------------------------------------------------------------------- 407 408template<typename T> 409status_t Parcel::write(const Flattenable<T>& val) { 410 const FlattenableHelper<T> helper(val); 411 return write(helper); 412} 413 414template<typename T> 415status_t Parcel::write(const LightFlattenable<T>& val) { 416 size_t size(val.getFlattenedSize()); 417 if (!val.isFixedSize()) { 418 status_t err = writeInt32(size); 419 if (err != NO_ERROR) { 420 return err; 421 } 422 } 423 if (size) { 424 void* buffer = writeInplace(size); 425 if (buffer == NULL) 426 return NO_MEMORY; 427 return val.flatten(buffer, size); 428 } 429 return NO_ERROR; 430} 431 432template<typename T> 433status_t Parcel::read(Flattenable<T>& val) const { 434 FlattenableHelper<T> helper(val); 435 return read(helper); 436} 437 438template<typename T> 439status_t Parcel::read(LightFlattenable<T>& val) const { 440 size_t size; 441 if (val.isFixedSize()) { 442 size = val.getFlattenedSize(); 443 } else { 444 int32_t s; 445 status_t err = readInt32(&s); 446 if (err != NO_ERROR) { 447 return err; 448 } 449 size = s; 450 } 451 if (size) { 452 void const* buffer = readInplace(size); 453 return buffer == NULL ? NO_MEMORY : 454 val.unflatten(buffer, size); 455 } 456 return NO_ERROR; 457} 458 459template<typename T> 460status_t Parcel::readStrongBinder(sp<T>* val) const { 461 sp<IBinder> tmp; 462 status_t ret = readStrongBinder(&tmp); 463 464 if (ret == OK) { 465 *val = interface_cast<T>(tmp); 466 467 if (val->get() == nullptr) { 468 return UNKNOWN_ERROR; 469 } 470 } 471 472 return ret; 473} 474 475template<typename T, typename U> 476status_t Parcel::unsafeReadTypedVector( 477 std::vector<T>* val, status_t(Parcel::*read_func)(U*) const) const { 478 val->clear(); 479 480 int32_t size; 481 status_t status = this->readInt32(&size); 482 483 if (status != OK) { 484 return status; 485 } 486 487 if (size < 0) { 488 return UNEXPECTED_NULL; 489 } 490 491 val->resize(size); 492 493 for (auto& v: *val) { 494 status = (this->*read_func)(&v); 495 496 if (status != OK) { 497 return status; 498 } 499 } 500 501 return OK; 502} 503 504template<typename T> 505status_t Parcel::readTypedVector(std::vector<T>* val, 506 status_t(Parcel::*read_func)(T*) const) const { 507 return unsafeReadTypedVector(val, read_func); 508} 509 510template<typename T, typename U> 511status_t Parcel::unsafeWriteTypedVector(const std::vector<T>& val, 512 status_t(Parcel::*write_func)(U)) { 513 if (val.size() > std::numeric_limits<int32_t>::max()) { 514 return BAD_VALUE; 515 } 516 517 status_t status = this->writeInt32(val.size()); 518 519 if (status != OK) { 520 return status; 521 } 522 523 for (const auto& item : val) { 524 status = (this->*write_func)(item); 525 526 if (status != OK) { 527 return status; 528 } 529 } 530 531 return OK; 532} 533 534template<typename T> 535status_t Parcel::writeTypedVector(const std::vector<T>& val, 536 status_t(Parcel::*write_func)(const T&)) { 537 return unsafeWriteTypedVector(val, write_func); 538} 539 540template<typename T> 541status_t Parcel::writeTypedVector(const std::vector<T>& val, 542 status_t(Parcel::*write_func)(T)) { 543 return unsafeWriteTypedVector(val, write_func); 544} 545 546// --------------------------------------------------------------------------- 547 548inline TextOutput& operator<<(TextOutput& to, const Parcel& parcel) 549{ 550 parcel.print(to); 551 return to; 552} 553 554// --------------------------------------------------------------------------- 555 556// Generic acquire and release of objects. 557void acquire_object(const sp<ProcessState>& proc, 558 const flat_binder_object& obj, const void* who); 559void release_object(const sp<ProcessState>& proc, 560 const flat_binder_object& obj, const void* who); 561 562void flatten_binder(const sp<ProcessState>& proc, 563 const sp<IBinder>& binder, flat_binder_object* out); 564void flatten_binder(const sp<ProcessState>& proc, 565 const wp<IBinder>& binder, flat_binder_object* out); 566status_t unflatten_binder(const sp<ProcessState>& proc, 567 const flat_binder_object& flat, sp<IBinder>* out); 568status_t unflatten_binder(const sp<ProcessState>& proc, 569 const flat_binder_object& flat, wp<IBinder>* out); 570 571}; // namespace android 572 573// --------------------------------------------------------------------------- 574 575#endif // ANDROID_PARCEL_H 576