Parcel.h revision 06673e38983baad380e818c5493b7faccf3b2393
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 <nativehelper/ScopedFd.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#include <binder/Parcelable.h> 33 34// --------------------------------------------------------------------------- 35namespace android { 36 37template <typename T> class Flattenable; 38template <typename T> class LightFlattenable; 39class IBinder; 40class IPCThreadState; 41class ProcessState; 42class String8; 43class TextOutput; 44 45class Parcel { 46 friend class IPCThreadState; 47public: 48 class ReadableBlob; 49 class WritableBlob; 50 51 Parcel(); 52 ~Parcel(); 53 54 const uint8_t* data() const; 55 size_t dataSize() const; 56 size_t dataAvail() const; 57 size_t dataPosition() const; 58 size_t dataCapacity() const; 59 60 status_t setDataSize(size_t size); 61 void setDataPosition(size_t pos) const; 62 status_t setDataCapacity(size_t size); 63 64 status_t setData(const uint8_t* buffer, size_t len); 65 66 status_t appendFrom(const Parcel *parcel, 67 size_t start, size_t len); 68 69 bool allowFds() const; 70 bool pushAllowFds(bool allowFds); 71 void restoreAllowFds(bool lastValue); 72 73 bool hasFileDescriptors() const; 74 75 // Writes the RPC header. 76 status_t writeInterfaceToken(const String16& interface); 77 78 // Parses the RPC header, returning true if the interface name 79 // in the header matches the expected interface from the caller. 80 // 81 // Additionally, enforceInterface does part of the work of 82 // propagating the StrictMode policy mask, populating the current 83 // IPCThreadState, which as an optimization may optionally be 84 // passed in. 85 bool enforceInterface(const String16& interface, 86 IPCThreadState* threadState = NULL) const; 87 bool checkInterface(IBinder*) const; 88 89 void freeData(); 90 91private: 92 const binder_size_t* objects() const; 93 94public: 95 size_t objectsCount() const; 96 97 status_t errorCheck() const; 98 void setError(status_t err); 99 100 status_t write(const void* data, size_t len); 101 void* writeInplace(size_t len); 102 status_t writeUnpadded(const void* data, size_t len); 103 status_t writeInt32(int32_t val); 104 status_t writeUint32(uint32_t val); 105 status_t writeInt64(int64_t val); 106 status_t writeUint64(uint64_t val); 107 status_t writeFloat(float val); 108 status_t writeDouble(double val); 109 status_t writeCString(const char* str); 110 status_t writeString8(const String8& str); 111 status_t writeString16(const String16& str); 112 status_t writeString16(const char16_t* str, size_t len); 113 status_t writeStrongBinder(const sp<IBinder>& val); 114 status_t writeWeakBinder(const wp<IBinder>& val); 115 status_t writeInt32Array(size_t len, const int32_t *val); 116 status_t writeByteArray(size_t len, const uint8_t *val); 117 status_t writeBool(bool val); 118 status_t writeChar(char16_t val); 119 status_t writeByte(int8_t val); 120 121 status_t writeByteVector(const std::vector<int8_t>& val); 122 status_t writeInt32Vector(const std::vector<int32_t>& val); 123 status_t writeInt64Vector(const std::vector<int64_t>& val); 124 status_t writeFloatVector(const std::vector<float>& val); 125 status_t writeDoubleVector(const std::vector<double>& val); 126 status_t writeBoolVector(const std::vector<bool>& val); 127 status_t writeCharVector(const std::vector<char16_t>& val); 128 status_t writeString16Vector(const std::vector<String16>& val); 129 130 status_t writeStrongBinderVector(const std::vector<sp<IBinder>>& val); 131 132 template<typename T> 133 status_t writeParcelableVector(const std::vector<T>& val); 134 status_t writeParcelable(const Parcelable& parcelable); 135 136 template<typename T> 137 status_t write(const Flattenable<T>& val); 138 139 template<typename T> 140 status_t write(const LightFlattenable<T>& val); 141 142 143 // Place a native_handle into the parcel (the native_handle's file- 144 // descriptors are dup'ed, so it is safe to delete the native_handle 145 // when this function returns). 146 // Doesn't take ownership of the native_handle. 147 status_t writeNativeHandle(const native_handle* handle); 148 149 // Place a file descriptor into the parcel. The given fd must remain 150 // valid for the lifetime of the parcel. 151 // The Parcel does not take ownership of the given fd unless you ask it to. 152 status_t writeFileDescriptor(int fd, bool takeOwnership = false); 153 154 // Place a file descriptor into the parcel. A dup of the fd is made, which 155 // will be closed once the parcel is destroyed. 156 status_t writeDupFileDescriptor(int fd); 157 158 // Place a file descriptor into the parcel. This will not affect the 159 // semantics of the smart file descriptor. A new descriptor will be 160 // created, and will be closed when the parcel is destroyed. 161 status_t writeUniqueFileDescriptor( 162 const ScopedFd& fd); 163 164 // Place a vector of file desciptors into the parcel. Each descriptor is 165 // dup'd as in writeDupFileDescriptor 166 status_t writeUniqueFileDescriptorVector( 167 const std::vector<ScopedFd>& val); 168 169 // Writes a blob to the parcel. 170 // If the blob is small, then it is stored in-place, otherwise it is 171 // transferred by way of an anonymous shared memory region. Prefer sending 172 // immutable blobs if possible since they may be subsequently transferred between 173 // processes without further copying whereas mutable blobs always need to be copied. 174 // The caller should call release() on the blob after writing its contents. 175 status_t writeBlob(size_t len, bool mutableCopy, WritableBlob* outBlob); 176 177 // Write an existing immutable blob file descriptor to the parcel. 178 // This allows the client to send the same blob to multiple processes 179 // as long as it keeps a dup of the blob file descriptor handy for later. 180 status_t writeDupImmutableBlobFileDescriptor(int fd); 181 182 status_t writeObject(const flat_binder_object& val, bool nullMetaData); 183 184 // Like Parcel.java's writeNoException(). Just writes a zero int32. 185 // Currently the native implementation doesn't do any of the StrictMode 186 // stack gathering and serialization that the Java implementation does. 187 status_t writeNoException(); 188 189 void remove(size_t start, size_t amt); 190 191 status_t read(void* outData, size_t len) const; 192 const void* readInplace(size_t len) const; 193 int32_t readInt32() const; 194 status_t readInt32(int32_t *pArg) const; 195 uint32_t readUint32() const; 196 status_t readUint32(uint32_t *pArg) const; 197 int64_t readInt64() const; 198 status_t readInt64(int64_t *pArg) const; 199 uint64_t readUint64() const; 200 status_t readUint64(uint64_t *pArg) const; 201 float readFloat() const; 202 status_t readFloat(float *pArg) const; 203 double readDouble() const; 204 status_t readDouble(double *pArg) const; 205 intptr_t readIntPtr() const; 206 status_t readIntPtr(intptr_t *pArg) const; 207 bool readBool() const; 208 status_t readBool(bool *pArg) const; 209 char16_t readChar() const; 210 status_t readChar(char16_t *pArg) const; 211 int8_t readByte() const; 212 status_t readByte(int8_t *pArg) const; 213 214 const char* readCString() const; 215 String8 readString8() const; 216 String16 readString16() const; 217 status_t readString16(String16* pArg) const; 218 const char16_t* readString16Inplace(size_t* outLen) const; 219 sp<IBinder> readStrongBinder() const; 220 status_t readStrongBinder(sp<IBinder>* val) const; 221 wp<IBinder> readWeakBinder() const; 222 223 template<typename T> 224 status_t readParcelableVector(std::vector<T>* val) const; 225 status_t readParcelable(Parcelable* parcelable) const; 226 227 template<typename T> 228 status_t readStrongBinder(sp<T>* val) const; 229 230 status_t readStrongBinderVector(std::vector<sp<IBinder>>* val) const; 231 232 status_t readByteVector(std::vector<int8_t>* val) const; 233 status_t readInt32Vector(std::vector<int32_t>* val) const; 234 status_t readInt64Vector(std::vector<int64_t>* val) const; 235 status_t readFloatVector(std::vector<float>* val) const; 236 status_t readDoubleVector(std::vector<double>* val) const; 237 status_t readBoolVector(std::vector<bool>* val) const; 238 status_t readCharVector(std::vector<char16_t>* val) const; 239 status_t readString16Vector(std::vector<String16>* val) const; 240 241 template<typename T> 242 status_t read(Flattenable<T>& val) const; 243 244 template<typename T> 245 status_t read(LightFlattenable<T>& val) const; 246 247 // Like Parcel.java's readExceptionCode(). Reads the first int32 248 // off of a Parcel's header, returning 0 or the negative error 249 // code on exceptions, but also deals with skipping over rich 250 // response headers. Callers should use this to read & parse the 251 // response headers rather than doing it by hand. 252 int32_t readExceptionCode() const; 253 254 // Retrieve native_handle from the parcel. This returns a copy of the 255 // parcel's native_handle (the caller takes ownership). The caller 256 // must free the native_handle with native_handle_close() and 257 // native_handle_delete(). 258 native_handle* readNativeHandle() const; 259 260 261 // Retrieve a file descriptor from the parcel. This returns the raw fd 262 // in the parcel, which you do not own -- use dup() to get your own copy. 263 int readFileDescriptor() const; 264 265 // Retrieve a smart file descriptor from the parcel. 266 status_t readUniqueFileDescriptor( 267 ScopedFd* val) const; 268 269 270 // Retrieve a vector of smart file descriptors from the parcel. 271 status_t readUniqueFileDescriptorVector( 272 std::vector<ScopedFd>* val) const; 273 274 // Reads a blob from the parcel. 275 // The caller should call release() on the blob after reading its contents. 276 status_t readBlob(size_t len, ReadableBlob* outBlob) const; 277 278 const flat_binder_object* readObject(bool nullMetaData) const; 279 280 // Explicitly close all file descriptors in the parcel. 281 void closeFileDescriptors(); 282 283 // Debugging: get metrics on current allocations. 284 static size_t getGlobalAllocSize(); 285 static size_t getGlobalAllocCount(); 286 287private: 288 typedef void (*release_func)(Parcel* parcel, 289 const uint8_t* data, size_t dataSize, 290 const binder_size_t* objects, size_t objectsSize, 291 void* cookie); 292 293 uintptr_t ipcData() const; 294 size_t ipcDataSize() const; 295 uintptr_t ipcObjects() const; 296 size_t ipcObjectsCount() const; 297 void ipcSetDataReference(const uint8_t* data, size_t dataSize, 298 const binder_size_t* objects, size_t objectsCount, 299 release_func relFunc, void* relCookie); 300 301public: 302 void print(TextOutput& to, uint32_t flags = 0) const; 303 304private: 305 Parcel(const Parcel& o); 306 Parcel& operator=(const Parcel& o); 307 308 status_t finishWrite(size_t len); 309 void releaseObjects(); 310 void acquireObjects(); 311 status_t growData(size_t len); 312 status_t restartWrite(size_t desired); 313 status_t continueWrite(size_t desired); 314 status_t writePointer(uintptr_t val); 315 status_t readPointer(uintptr_t *pArg) const; 316 uintptr_t readPointer() const; 317 void freeDataNoInit(); 318 void initState(); 319 void scanForFds() const; 320 321 template<class T> 322 status_t readAligned(T *pArg) const; 323 324 template<class T> T readAligned() const; 325 326 template<class T> 327 status_t writeAligned(T val); 328 329 template<typename T, typename U> 330 status_t unsafeReadTypedVector(std::vector<T>* val, 331 status_t(Parcel::*read_func)(U*) const) const; 332 template<typename T> 333 status_t readTypedVector(std::vector<T>* val, 334 status_t(Parcel::*read_func)(T*) const) const; 335 template<typename T, typename U> 336 status_t unsafeWriteTypedVector(const std::vector<T>& val, 337 status_t(Parcel::*write_func)(U)); 338 template<typename T> 339 status_t writeTypedVector(const std::vector<T>& val, 340 status_t(Parcel::*write_func)(const T&)); 341 template<typename T> 342 status_t writeTypedVector(const std::vector<T>& val, 343 status_t(Parcel::*write_func)(T)); 344 345 status_t mError; 346 uint8_t* mData; 347 size_t mDataSize; 348 size_t mDataCapacity; 349 mutable size_t mDataPos; 350 binder_size_t* mObjects; 351 size_t mObjectsSize; 352 size_t mObjectsCapacity; 353 mutable size_t mNextObjectHint; 354 355 mutable bool mFdsKnown; 356 mutable bool mHasFds; 357 bool mAllowFds; 358 359 release_func mOwner; 360 void* mOwnerCookie; 361 362 class Blob { 363 public: 364 Blob(); 365 ~Blob(); 366 367 void clear(); 368 void release(); 369 inline size_t size() const { return mSize; } 370 inline int fd() const { return mFd; }; 371 inline bool isMutable() const { return mMutable; } 372 373 protected: 374 void init(int fd, void* data, size_t size, bool isMutable); 375 376 int mFd; // owned by parcel so not closed when released 377 void* mData; 378 size_t mSize; 379 bool mMutable; 380 }; 381 382 class FlattenableHelperInterface { 383 protected: 384 ~FlattenableHelperInterface() { } 385 public: 386 virtual size_t getFlattenedSize() const = 0; 387 virtual size_t getFdCount() const = 0; 388 virtual status_t flatten(void* buffer, size_t size, int* fds, size_t count) const = 0; 389 virtual status_t unflatten(void const* buffer, size_t size, int const* fds, size_t count) = 0; 390 }; 391 392 template<typename T> 393 class FlattenableHelper : public FlattenableHelperInterface { 394 friend class Parcel; 395 const Flattenable<T>& val; 396 explicit FlattenableHelper(const Flattenable<T>& val) : val(val) { } 397 398 public: 399 virtual size_t getFlattenedSize() const { 400 return val.getFlattenedSize(); 401 } 402 virtual size_t getFdCount() const { 403 return val.getFdCount(); 404 } 405 virtual status_t flatten(void* buffer, size_t size, int* fds, size_t count) const { 406 return val.flatten(buffer, size, fds, count); 407 } 408 virtual status_t unflatten(void const* buffer, size_t size, int const* fds, size_t count) { 409 return const_cast<Flattenable<T>&>(val).unflatten(buffer, size, fds, count); 410 } 411 }; 412 status_t write(const FlattenableHelperInterface& val); 413 status_t read(FlattenableHelperInterface& val) const; 414 415public: 416 class ReadableBlob : public Blob { 417 friend class Parcel; 418 public: 419 inline const void* data() const { return mData; } 420 inline void* mutableData() { return isMutable() ? mData : NULL; } 421 }; 422 423 class WritableBlob : public Blob { 424 friend class Parcel; 425 public: 426 inline void* data() { return mData; } 427 }; 428 429private: 430 size_t mBlobAshmemSize; 431 432public: 433 size_t getBlobAshmemSize() const; 434}; 435 436// --------------------------------------------------------------------------- 437 438template<typename T> 439status_t Parcel::write(const Flattenable<T>& val) { 440 const FlattenableHelper<T> helper(val); 441 return write(helper); 442} 443 444template<typename T> 445status_t Parcel::write(const LightFlattenable<T>& val) { 446 size_t size(val.getFlattenedSize()); 447 if (!val.isFixedSize()) { 448 status_t err = writeInt32(size); 449 if (err != NO_ERROR) { 450 return err; 451 } 452 } 453 if (size) { 454 void* buffer = writeInplace(size); 455 if (buffer == NULL) 456 return NO_MEMORY; 457 return val.flatten(buffer, size); 458 } 459 return NO_ERROR; 460} 461 462template<typename T> 463status_t Parcel::read(Flattenable<T>& val) const { 464 FlattenableHelper<T> helper(val); 465 return read(helper); 466} 467 468template<typename T> 469status_t Parcel::read(LightFlattenable<T>& val) const { 470 size_t size; 471 if (val.isFixedSize()) { 472 size = val.getFlattenedSize(); 473 } else { 474 int32_t s; 475 status_t err = readInt32(&s); 476 if (err != NO_ERROR) { 477 return err; 478 } 479 size = s; 480 } 481 if (size) { 482 void const* buffer = readInplace(size); 483 return buffer == NULL ? NO_MEMORY : 484 val.unflatten(buffer, size); 485 } 486 return NO_ERROR; 487} 488 489template<typename T> 490status_t Parcel::readStrongBinder(sp<T>* val) const { 491 sp<IBinder> tmp; 492 status_t ret = readStrongBinder(&tmp); 493 494 if (ret == OK) { 495 *val = interface_cast<T>(tmp); 496 497 if (val->get() == nullptr) { 498 return UNKNOWN_ERROR; 499 } 500 } 501 502 return ret; 503} 504 505template<typename T, typename U> 506status_t Parcel::unsafeReadTypedVector( 507 std::vector<T>* val, status_t(Parcel::*read_func)(U*) const) const { 508 val->clear(); 509 510 int32_t size; 511 status_t status = this->readInt32(&size); 512 513 if (status != OK) { 514 return status; 515 } 516 517 if (size < 0) { 518 return UNEXPECTED_NULL; 519 } 520 521 val->resize(size); 522 523 for (auto& v: *val) { 524 status = (this->*read_func)(&v); 525 526 if (status != OK) { 527 return status; 528 } 529 } 530 531 return OK; 532} 533 534template<typename T> 535status_t Parcel::readTypedVector(std::vector<T>* val, 536 status_t(Parcel::*read_func)(T*) const) const { 537 return unsafeReadTypedVector(val, read_func); 538} 539 540template<typename T, typename U> 541status_t Parcel::unsafeWriteTypedVector(const std::vector<T>& val, 542 status_t(Parcel::*write_func)(U)) { 543 if (val.size() > std::numeric_limits<int32_t>::max()) { 544 return BAD_VALUE; 545 } 546 547 status_t status = this->writeInt32(val.size()); 548 549 if (status != OK) { 550 return status; 551 } 552 553 for (const auto& item : val) { 554 status = (this->*write_func)(item); 555 556 if (status != OK) { 557 return status; 558 } 559 } 560 561 return OK; 562} 563 564template<typename T> 565status_t Parcel::writeTypedVector(const std::vector<T>& val, 566 status_t(Parcel::*write_func)(const T&)) { 567 return unsafeWriteTypedVector(val, write_func); 568} 569 570template<typename T> 571status_t Parcel::writeTypedVector(const std::vector<T>& val, 572 status_t(Parcel::*write_func)(T)) { 573 return unsafeWriteTypedVector(val, write_func); 574} 575 576template<typename T> 577status_t Parcel::readParcelableVector(std::vector<T>* val) const { 578 return unsafeReadTypedVector(val, &Parcel::readParcelable); 579} 580 581template<typename T> 582status_t Parcel::writeParcelableVector(const std::vector<T>& val) { 583 return unsafeWriteTypedVector(val, &Parcel::writeParcelable); 584} 585 586// --------------------------------------------------------------------------- 587 588inline TextOutput& operator<<(TextOutput& to, const Parcel& parcel) 589{ 590 parcel.print(to); 591 return to; 592} 593 594// --------------------------------------------------------------------------- 595 596// Generic acquire and release of objects. 597void acquire_object(const sp<ProcessState>& proc, 598 const flat_binder_object& obj, const void* who); 599void release_object(const sp<ProcessState>& proc, 600 const flat_binder_object& obj, const void* who); 601 602void flatten_binder(const sp<ProcessState>& proc, 603 const sp<IBinder>& binder, flat_binder_object* out); 604void flatten_binder(const sp<ProcessState>& proc, 605 const wp<IBinder>& binder, flat_binder_object* out); 606status_t unflatten_binder(const sp<ProcessState>& proc, 607 const flat_binder_object& flat, sp<IBinder>* out); 608status_t unflatten_binder(const sp<ProcessState>& proc, 609 const flat_binder_object& flat, wp<IBinder>* out); 610 611}; // namespace android 612 613// --------------------------------------------------------------------------- 614 615#endif // ANDROID_PARCEL_H 616