Parcel.h revision 6c31acd969ffc754e514885fa7f4d0c25403f580
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#include <binder/Parcelable.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 writeParcelableVector(const std::vector<T>& val); 133 status_t writeParcelable(const Parcelable& parcelable); 134 135 template<typename T> 136 status_t write(const Flattenable<T>& val); 137 138 template<typename T> 139 status_t write(const LightFlattenable<T>& val); 140 141 142 // Place a native_handle into the parcel (the native_handle's file- 143 // descriptors are dup'ed, so it is safe to delete the native_handle 144 // when this function returns). 145 // Doesn't take ownership of the native_handle. 146 status_t writeNativeHandle(const native_handle* handle); 147 148 // Place a file descriptor into the parcel. The given fd must remain 149 // valid for the lifetime of the parcel. 150 // The Parcel does not take ownership of the given fd unless you ask it to. 151 status_t writeFileDescriptor(int fd, bool takeOwnership = false); 152 153 // Place a file descriptor into the parcel. A dup of the fd is made, which 154 // will be closed once the parcel is destroyed. 155 status_t writeDupFileDescriptor(int fd); 156 157 // Writes a blob to the parcel. 158 // If the blob is small, then it is stored in-place, otherwise it is 159 // transferred by way of an anonymous shared memory region. Prefer sending 160 // immutable blobs if possible since they may be subsequently transferred between 161 // processes without further copying whereas mutable blobs always need to be copied. 162 // The caller should call release() on the blob after writing its contents. 163 status_t writeBlob(size_t len, bool mutableCopy, WritableBlob* outBlob); 164 165 // Write an existing immutable blob file descriptor to the parcel. 166 // This allows the client to send the same blob to multiple processes 167 // as long as it keeps a dup of the blob file descriptor handy for later. 168 status_t writeDupImmutableBlobFileDescriptor(int fd); 169 170 status_t writeObject(const flat_binder_object& val, bool nullMetaData); 171 172 // Like Parcel.java's writeNoException(). Just writes a zero int32. 173 // Currently the native implementation doesn't do any of the StrictMode 174 // stack gathering and serialization that the Java implementation does. 175 status_t writeNoException(); 176 177 void remove(size_t start, size_t amt); 178 179 status_t read(void* outData, size_t len) const; 180 const void* readInplace(size_t len) const; 181 int32_t readInt32() const; 182 status_t readInt32(int32_t *pArg) const; 183 uint32_t readUint32() const; 184 status_t readUint32(uint32_t *pArg) const; 185 int64_t readInt64() const; 186 status_t readInt64(int64_t *pArg) const; 187 uint64_t readUint64() const; 188 status_t readUint64(uint64_t *pArg) const; 189 float readFloat() const; 190 status_t readFloat(float *pArg) const; 191 double readDouble() const; 192 status_t readDouble(double *pArg) const; 193 intptr_t readIntPtr() const; 194 status_t readIntPtr(intptr_t *pArg) const; 195 bool readBool() const; 196 status_t readBool(bool *pArg) const; 197 char16_t readChar() const; 198 status_t readChar(char16_t *pArg) const; 199 int8_t readByte() const; 200 status_t readByte(int8_t *pArg) const; 201 202 const char* readCString() const; 203 String8 readString8() const; 204 String16 readString16() const; 205 status_t readString16(String16* pArg) const; 206 const char16_t* readString16Inplace(size_t* outLen) const; 207 sp<IBinder> readStrongBinder() const; 208 status_t readStrongBinder(sp<IBinder>* val) const; 209 wp<IBinder> readWeakBinder() const; 210 211 template<typename T> 212 status_t readParcelableVector(std::vector<T>* val) const; 213 status_t readParcelable(Parcelable* parcelable) const; 214 215 template<typename T> 216 status_t readStrongBinder(sp<T>* val) const; 217 218 status_t readStrongBinderVector(std::vector<sp<IBinder>>* val) const; 219 220 status_t readByteVector(std::vector<int8_t>* val) const; 221 status_t readInt32Vector(std::vector<int32_t>* val) const; 222 status_t readInt64Vector(std::vector<int64_t>* val) const; 223 status_t readFloatVector(std::vector<float>* val) const; 224 status_t readDoubleVector(std::vector<double>* val) const; 225 status_t readBoolVector(std::vector<bool>* val) const; 226 status_t readCharVector(std::vector<char16_t>* val) const; 227 status_t readString16Vector(std::vector<String16>* val) const; 228 229 template<typename T> 230 status_t read(Flattenable<T>& val) const; 231 232 template<typename T> 233 status_t read(LightFlattenable<T>& val) const; 234 235 // Like Parcel.java's readExceptionCode(). Reads the first int32 236 // off of a Parcel's header, returning 0 or the negative error 237 // code on exceptions, but also deals with skipping over rich 238 // response headers. Callers should use this to read & parse the 239 // response headers rather than doing it by hand. 240 int32_t readExceptionCode() const; 241 242 // Retrieve native_handle from the parcel. This returns a copy of the 243 // parcel's native_handle (the caller takes ownership). The caller 244 // must free the native_handle with native_handle_close() and 245 // native_handle_delete(). 246 native_handle* readNativeHandle() const; 247 248 249 // Retrieve a file descriptor from the parcel. This returns the raw fd 250 // in the parcel, which you do not own -- use dup() to get your own copy. 251 int readFileDescriptor() const; 252 253 // Reads a blob from the parcel. 254 // The caller should call release() on the blob after reading its contents. 255 status_t readBlob(size_t len, ReadableBlob* outBlob) const; 256 257 const flat_binder_object* readObject(bool nullMetaData) const; 258 259 // Explicitly close all file descriptors in the parcel. 260 void closeFileDescriptors(); 261 262 // Debugging: get metrics on current allocations. 263 static size_t getGlobalAllocSize(); 264 static size_t getGlobalAllocCount(); 265 266private: 267 typedef void (*release_func)(Parcel* parcel, 268 const uint8_t* data, size_t dataSize, 269 const binder_size_t* objects, size_t objectsSize, 270 void* cookie); 271 272 uintptr_t ipcData() const; 273 size_t ipcDataSize() const; 274 uintptr_t ipcObjects() const; 275 size_t ipcObjectsCount() const; 276 void ipcSetDataReference(const uint8_t* data, size_t dataSize, 277 const binder_size_t* objects, size_t objectsCount, 278 release_func relFunc, void* relCookie); 279 280public: 281 void print(TextOutput& to, uint32_t flags = 0) const; 282 283private: 284 Parcel(const Parcel& o); 285 Parcel& operator=(const Parcel& o); 286 287 status_t finishWrite(size_t len); 288 void releaseObjects(); 289 void acquireObjects(); 290 status_t growData(size_t len); 291 status_t restartWrite(size_t desired); 292 status_t continueWrite(size_t desired); 293 status_t writePointer(uintptr_t val); 294 status_t readPointer(uintptr_t *pArg) const; 295 uintptr_t readPointer() const; 296 void freeDataNoInit(); 297 void initState(); 298 void scanForFds() const; 299 300 template<class T> 301 status_t readAligned(T *pArg) const; 302 303 template<class T> T readAligned() const; 304 305 template<class T> 306 status_t writeAligned(T val); 307 308 template<typename T, typename U> 309 status_t unsafeReadTypedVector(std::vector<T>* val, 310 status_t(Parcel::*read_func)(U*) const) const; 311 template<typename T> 312 status_t readTypedVector(std::vector<T>* val, 313 status_t(Parcel::*read_func)(T*) const) const; 314 template<typename T, typename U> 315 status_t unsafeWriteTypedVector(const std::vector<T>& val, 316 status_t(Parcel::*write_func)(U)); 317 template<typename T> 318 status_t writeTypedVector(const std::vector<T>& val, 319 status_t(Parcel::*write_func)(const T&)); 320 template<typename T> 321 status_t writeTypedVector(const std::vector<T>& val, 322 status_t(Parcel::*write_func)(T)); 323 324 status_t mError; 325 uint8_t* mData; 326 size_t mDataSize; 327 size_t mDataCapacity; 328 mutable size_t mDataPos; 329 binder_size_t* mObjects; 330 size_t mObjectsSize; 331 size_t mObjectsCapacity; 332 mutable size_t mNextObjectHint; 333 334 mutable bool mFdsKnown; 335 mutable bool mHasFds; 336 bool mAllowFds; 337 338 release_func mOwner; 339 void* mOwnerCookie; 340 341 class Blob { 342 public: 343 Blob(); 344 ~Blob(); 345 346 void clear(); 347 void release(); 348 inline size_t size() const { return mSize; } 349 inline int fd() const { return mFd; }; 350 inline bool isMutable() const { return mMutable; } 351 352 protected: 353 void init(int fd, void* data, size_t size, bool isMutable); 354 355 int mFd; // owned by parcel so not closed when released 356 void* mData; 357 size_t mSize; 358 bool mMutable; 359 }; 360 361 class FlattenableHelperInterface { 362 protected: 363 ~FlattenableHelperInterface() { } 364 public: 365 virtual size_t getFlattenedSize() const = 0; 366 virtual size_t getFdCount() const = 0; 367 virtual status_t flatten(void* buffer, size_t size, int* fds, size_t count) const = 0; 368 virtual status_t unflatten(void const* buffer, size_t size, int const* fds, size_t count) = 0; 369 }; 370 371 template<typename T> 372 class FlattenableHelper : public FlattenableHelperInterface { 373 friend class Parcel; 374 const Flattenable<T>& val; 375 explicit FlattenableHelper(const Flattenable<T>& val) : val(val) { } 376 377 public: 378 virtual size_t getFlattenedSize() const { 379 return val.getFlattenedSize(); 380 } 381 virtual size_t getFdCount() const { 382 return val.getFdCount(); 383 } 384 virtual status_t flatten(void* buffer, size_t size, int* fds, size_t count) const { 385 return val.flatten(buffer, size, fds, count); 386 } 387 virtual status_t unflatten(void const* buffer, size_t size, int const* fds, size_t count) { 388 return const_cast<Flattenable<T>&>(val).unflatten(buffer, size, fds, count); 389 } 390 }; 391 status_t write(const FlattenableHelperInterface& val); 392 status_t read(FlattenableHelperInterface& val) const; 393 394public: 395 class ReadableBlob : public Blob { 396 friend class Parcel; 397 public: 398 inline const void* data() const { return mData; } 399 inline void* mutableData() { return isMutable() ? mData : NULL; } 400 }; 401 402 class WritableBlob : public Blob { 403 friend class Parcel; 404 public: 405 inline void* data() { return mData; } 406 }; 407 408private: 409 size_t mOpenAshmemSize; 410 411public: 412 // TODO: Remove once ABI can be changed. 413 size_t getBlobAshmemSize() const; 414 size_t getOpenAshmemSize() const; 415}; 416 417// --------------------------------------------------------------------------- 418 419template<typename T> 420status_t Parcel::write(const Flattenable<T>& val) { 421 const FlattenableHelper<T> helper(val); 422 return write(helper); 423} 424 425template<typename T> 426status_t Parcel::write(const LightFlattenable<T>& val) { 427 size_t size(val.getFlattenedSize()); 428 if (!val.isFixedSize()) { 429 status_t err = writeInt32(size); 430 if (err != NO_ERROR) { 431 return err; 432 } 433 } 434 if (size) { 435 void* buffer = writeInplace(size); 436 if (buffer == NULL) 437 return NO_MEMORY; 438 return val.flatten(buffer, size); 439 } 440 return NO_ERROR; 441} 442 443template<typename T> 444status_t Parcel::read(Flattenable<T>& val) const { 445 FlattenableHelper<T> helper(val); 446 return read(helper); 447} 448 449template<typename T> 450status_t Parcel::read(LightFlattenable<T>& val) const { 451 size_t size; 452 if (val.isFixedSize()) { 453 size = val.getFlattenedSize(); 454 } else { 455 int32_t s; 456 status_t err = readInt32(&s); 457 if (err != NO_ERROR) { 458 return err; 459 } 460 size = s; 461 } 462 if (size) { 463 void const* buffer = readInplace(size); 464 return buffer == NULL ? NO_MEMORY : 465 val.unflatten(buffer, size); 466 } 467 return NO_ERROR; 468} 469 470template<typename T> 471status_t Parcel::readStrongBinder(sp<T>* val) const { 472 sp<IBinder> tmp; 473 status_t ret = readStrongBinder(&tmp); 474 475 if (ret == OK) { 476 *val = interface_cast<T>(tmp); 477 478 if (val->get() == nullptr) { 479 return UNKNOWN_ERROR; 480 } 481 } 482 483 return ret; 484} 485 486template<typename T, typename U> 487status_t Parcel::unsafeReadTypedVector( 488 std::vector<T>* val, status_t(Parcel::*read_func)(U*) const) const { 489 val->clear(); 490 491 int32_t size; 492 status_t status = this->readInt32(&size); 493 494 if (status != OK) { 495 return status; 496 } 497 498 if (size < 0) { 499 return UNEXPECTED_NULL; 500 } 501 502 val->resize(size); 503 504 for (auto& v: *val) { 505 status = (this->*read_func)(&v); 506 507 if (status != OK) { 508 return status; 509 } 510 } 511 512 return OK; 513} 514 515template<typename T> 516status_t Parcel::readTypedVector(std::vector<T>* val, 517 status_t(Parcel::*read_func)(T*) const) const { 518 return unsafeReadTypedVector(val, read_func); 519} 520 521template<typename T, typename U> 522status_t Parcel::unsafeWriteTypedVector(const std::vector<T>& val, 523 status_t(Parcel::*write_func)(U)) { 524 if (val.size() > std::numeric_limits<int32_t>::max()) { 525 return BAD_VALUE; 526 } 527 528 status_t status = this->writeInt32(val.size()); 529 530 if (status != OK) { 531 return status; 532 } 533 534 for (const auto& item : val) { 535 status = (this->*write_func)(item); 536 537 if (status != OK) { 538 return status; 539 } 540 } 541 542 return OK; 543} 544 545template<typename T> 546status_t Parcel::writeTypedVector(const std::vector<T>& val, 547 status_t(Parcel::*write_func)(const T&)) { 548 return unsafeWriteTypedVector(val, write_func); 549} 550 551template<typename T> 552status_t Parcel::writeTypedVector(const std::vector<T>& val, 553 status_t(Parcel::*write_func)(T)) { 554 return unsafeWriteTypedVector(val, write_func); 555} 556 557template<typename T> 558status_t Parcel::readParcelableVector(std::vector<T>* val) const { 559 return unsafeReadTypedVector(val, &Parcel::readParcelable); 560} 561 562template<typename T> 563status_t Parcel::writeParcelableVector(const std::vector<T>& val) { 564 return unsafeWriteTypedVector(val, &Parcel::writeParcelable); 565} 566 567// --------------------------------------------------------------------------- 568 569inline TextOutput& operator<<(TextOutput& to, const Parcel& parcel) 570{ 571 parcel.print(to); 572 return to; 573} 574 575// --------------------------------------------------------------------------- 576 577// Generic acquire and release of objects. 578void acquire_object(const sp<ProcessState>& proc, 579 const flat_binder_object& obj, const void* who); 580void release_object(const sp<ProcessState>& proc, 581 const flat_binder_object& obj, const void* who); 582 583void flatten_binder(const sp<ProcessState>& proc, 584 const sp<IBinder>& binder, flat_binder_object* out); 585void flatten_binder(const sp<ProcessState>& proc, 586 const wp<IBinder>& binder, flat_binder_object* out); 587status_t unflatten_binder(const sp<ProcessState>& proc, 588 const flat_binder_object& flat, sp<IBinder>* out); 589status_t unflatten_binder(const sp<ProcessState>& proc, 590 const flat_binder_object& flat, wp<IBinder>* out); 591 592}; // namespace android 593 594// --------------------------------------------------------------------------- 595 596#endif // ANDROID_PARCEL_H 597