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 <cutils/native_handle.h> 21 #include <utils/Errors.h> 22 #include <utils/RefBase.h> 23 #include <utils/String16.h> 24 #include <utils/Vector.h> 25 #include <utils/Flattenable.h> 26 #include <linux/binder.h> 27 28 // --------------------------------------------------------------------------- 29 namespace android { 30 31 template <typename T> class Flattenable; 32 template <typename T> class LightFlattenable; 33 class IBinder; 34 class IPCThreadState; 35 class ProcessState; 36 class String8; 37 class TextOutput; 38 39 class Parcel { 40 friend class IPCThreadState; 41 public: 42 class ReadableBlob; 43 class WritableBlob; 44 45 Parcel(); 46 ~Parcel(); 47 48 const uint8_t* data() const; 49 size_t dataSize() const; 50 size_t dataAvail() const; 51 size_t dataPosition() const; 52 size_t dataCapacity() const; 53 54 status_t setDataSize(size_t size); 55 void setDataPosition(size_t pos) const; 56 status_t setDataCapacity(size_t size); 57 58 status_t setData(const uint8_t* buffer, size_t len); 59 60 status_t appendFrom(const Parcel *parcel, 61 size_t start, size_t len); 62 63 bool pushAllowFds(bool allowFds); 64 void restoreAllowFds(bool lastValue); 65 66 bool hasFileDescriptors() const; 67 68 // Writes the RPC header. 69 status_t writeInterfaceToken(const String16& interface); 70 71 // Parses the RPC header, returning true if the interface name 72 // in the header matches the expected interface from the caller. 73 // 74 // Additionally, enforceInterface does part of the work of 75 // propagating the StrictMode policy mask, populating the current 76 // IPCThreadState, which as an optimization may optionally be 77 // passed in. 78 bool enforceInterface(const String16& interface, 79 IPCThreadState* threadState = NULL) const; 80 bool checkInterface(IBinder*) const; 81 82 void freeData(); 83 84 private: 85 const binder_size_t* objects() const; 86 87 public: 88 size_t objectsCount() const; 89 90 status_t errorCheck() const; 91 void setError(status_t err); 92 93 status_t write(const void* data, size_t len); 94 void* writeInplace(size_t len); 95 status_t writeUnpadded(const void* data, size_t len); 96 status_t writeInt32(int32_t val); 97 status_t writeInt64(int64_t val); 98 status_t writeFloat(float val); 99 status_t writeDouble(double val); 100 status_t writeCString(const char* str); 101 status_t writeString8(const String8& str); 102 status_t writeString16(const String16& str); 103 status_t writeString16(const char16_t* str, size_t len); 104 status_t writeStrongBinder(const sp<IBinder>& val); 105 status_t writeWeakBinder(const wp<IBinder>& val); 106 status_t writeInt32Array(size_t len, const int32_t *val); 107 status_t writeByteArray(size_t len, const uint8_t *val); 108 109 template<typename T> 110 status_t write(const Flattenable<T>& val); 111 112 template<typename T> 113 status_t write(const LightFlattenable<T>& val); 114 115 116 // Place a native_handle into the parcel (the native_handle's file- 117 // descriptors are dup'ed, so it is safe to delete the native_handle 118 // when this function returns). 119 // Doesn't take ownership of the native_handle. 120 status_t writeNativeHandle(const native_handle* handle); 121 122 // Place a file descriptor into the parcel. The given fd must remain 123 // valid for the lifetime of the parcel. 124 // The Parcel does not take ownership of the given fd unless you ask it to. 125 status_t writeFileDescriptor(int fd, bool takeOwnership = false); 126 127 // Place a file descriptor into the parcel. A dup of the fd is made, which 128 // will be closed once the parcel is destroyed. 129 status_t writeDupFileDescriptor(int fd); 130 131 // Writes a raw fd and optional comm channel fd to the parcel as a ParcelFileDescriptor. 132 // A dup's of the fds are made, which will be closed once the parcel is destroyed. 133 // Null values are passed as -1. 134 status_t writeParcelFileDescriptor(int fd, int commChannel = -1); 135 136 // Writes a blob to the parcel. 137 // If the blob is small, then it is stored in-place, otherwise it is 138 // transferred by way of an anonymous shared memory region. 139 // The caller should call release() on the blob after writing its contents. 140 status_t writeBlob(size_t len, WritableBlob* outBlob); 141 142 status_t writeObject(const flat_binder_object& val, bool nullMetaData); 143 144 // Like Parcel.java's writeNoException(). Just writes a zero int32. 145 // Currently the native implementation doesn't do any of the StrictMode 146 // stack gathering and serialization that the Java implementation does. 147 status_t writeNoException(); 148 149 void remove(size_t start, size_t amt); 150 151 status_t read(void* outData, size_t len) const; 152 const void* readInplace(size_t len) const; 153 int32_t readInt32() const; 154 status_t readInt32(int32_t *pArg) const; 155 int64_t readInt64() const; 156 status_t readInt64(int64_t *pArg) const; 157 float readFloat() const; 158 status_t readFloat(float *pArg) const; 159 double readDouble() const; 160 status_t readDouble(double *pArg) const; 161 intptr_t readIntPtr() const; 162 status_t readIntPtr(intptr_t *pArg) const; 163 164 const char* readCString() const; 165 String8 readString8() const; 166 String16 readString16() const; 167 const char16_t* readString16Inplace(size_t* outLen) const; 168 sp<IBinder> readStrongBinder() const; 169 wp<IBinder> readWeakBinder() const; 170 171 template<typename T> 172 status_t read(Flattenable<T>& val) const; 173 174 template<typename T> 175 status_t read(LightFlattenable<T>& val) const; 176 177 // Like Parcel.java's readExceptionCode(). Reads the first int32 178 // off of a Parcel's header, returning 0 or the negative error 179 // code on exceptions, but also deals with skipping over rich 180 // response headers. Callers should use this to read & parse the 181 // response headers rather than doing it by hand. 182 int32_t readExceptionCode() const; 183 184 // Retrieve native_handle from the parcel. This returns a copy of the 185 // parcel's native_handle (the caller takes ownership). The caller 186 // must free the native_handle with native_handle_close() and 187 // native_handle_delete(). 188 native_handle* readNativeHandle() const; 189 190 191 // Retrieve a file descriptor from the parcel. This returns the raw fd 192 // in the parcel, which you do not own -- use dup() to get your own copy. 193 int readFileDescriptor() const; 194 195 // Reads a ParcelFileDescriptor from the parcel. Returns the raw fd as 196 // the result, and the optional comm channel fd in outCommChannel. 197 // Null values are returned as -1. 198 int readParcelFileDescriptor(int& outCommChannel) const; 199 200 // Reads a blob from the parcel. 201 // The caller should call release() on the blob after reading its contents. 202 status_t readBlob(size_t len, ReadableBlob* outBlob) const; 203 204 const flat_binder_object* readObject(bool nullMetaData) const; 205 206 // Explicitly close all file descriptors in the parcel. 207 void closeFileDescriptors(); 208 209 // Debugging: get metrics on current allocations. 210 static size_t getGlobalAllocSize(); 211 static size_t getGlobalAllocCount(); 212 213 private: 214 typedef void (*release_func)(Parcel* parcel, 215 const uint8_t* data, size_t dataSize, 216 const binder_size_t* objects, size_t objectsSize, 217 void* cookie); 218 219 uintptr_t ipcData() const; 220 size_t ipcDataSize() const; 221 uintptr_t ipcObjects() const; 222 size_t ipcObjectsCount() const; 223 void ipcSetDataReference(const uint8_t* data, size_t dataSize, 224 const binder_size_t* objects, size_t objectsCount, 225 release_func relFunc, void* relCookie); 226 227 public: 228 void print(TextOutput& to, uint32_t flags = 0) const; 229 230 private: 231 Parcel(const Parcel& o); 232 Parcel& operator=(const Parcel& o); 233 234 status_t finishWrite(size_t len); 235 void releaseObjects(); 236 void acquireObjects(); 237 status_t growData(size_t len); 238 status_t restartWrite(size_t desired); 239 status_t continueWrite(size_t desired); 240 status_t writePointer(uintptr_t val); 241 status_t readPointer(uintptr_t *pArg) const; 242 uintptr_t readPointer() const; 243 void freeDataNoInit(); 244 void initState(); 245 void scanForFds() const; 246 247 template<class T> 248 status_t readAligned(T *pArg) const; 249 250 template<class T> T readAligned() const; 251 252 template<class T> 253 status_t writeAligned(T val); 254 255 status_t mError; 256 uint8_t* mData; 257 size_t mDataSize; 258 size_t mDataCapacity; 259 mutable size_t mDataPos; 260 binder_size_t* mObjects; 261 size_t mObjectsSize; 262 size_t mObjectsCapacity; 263 mutable size_t mNextObjectHint; 264 265 mutable bool mFdsKnown; 266 mutable bool mHasFds; 267 bool mAllowFds; 268 269 release_func mOwner; 270 void* mOwnerCookie; 271 272 class Blob { 273 public: 274 Blob(); 275 ~Blob(); 276 277 void release(); 278 inline size_t size() const { return mSize; } 279 280 protected: 281 void init(bool mapped, void* data, size_t size); 282 void clear(); 283 284 bool mMapped; 285 void* mData; 286 size_t mSize; 287 }; 288 289 class FlattenableHelperInterface { 290 protected: 291 ~FlattenableHelperInterface() { } 292 public: 293 virtual size_t getFlattenedSize() const = 0; 294 virtual size_t getFdCount() const = 0; 295 virtual status_t flatten(void* buffer, size_t size, int* fds, size_t count) const = 0; 296 virtual status_t unflatten(void const* buffer, size_t size, int const* fds, size_t count) = 0; 297 }; 298 299 template<typename T> 300 class FlattenableHelper : public FlattenableHelperInterface { 301 friend class Parcel; 302 const Flattenable<T>& val; 303 explicit FlattenableHelper(const Flattenable<T>& val) : val(val) { } 304 305 public: 306 virtual size_t getFlattenedSize() const { 307 return val.getFlattenedSize(); 308 } 309 virtual size_t getFdCount() const { 310 return val.getFdCount(); 311 } 312 virtual status_t flatten(void* buffer, size_t size, int* fds, size_t count) const { 313 return val.flatten(buffer, size, fds, count); 314 } 315 virtual status_t unflatten(void const* buffer, size_t size, int const* fds, size_t count) { 316 return const_cast<Flattenable<T>&>(val).unflatten(buffer, size, fds, count); 317 } 318 }; 319 status_t write(const FlattenableHelperInterface& val); 320 status_t read(FlattenableHelperInterface& val) const; 321 322 public: 323 class ReadableBlob : public Blob { 324 friend class Parcel; 325 public: 326 inline const void* data() const { return mData; } 327 }; 328 329 class WritableBlob : public Blob { 330 friend class Parcel; 331 public: 332 inline void* data() { return mData; } 333 }; 334 }; 335 336 // --------------------------------------------------------------------------- 337 338 template<typename T> 339 status_t Parcel::write(const Flattenable<T>& val) { 340 const FlattenableHelper<T> helper(val); 341 return write(helper); 342 } 343 344 template<typename T> 345 status_t Parcel::write(const LightFlattenable<T>& val) { 346 size_t size(val.getFlattenedSize()); 347 if (!val.isFixedSize()) { 348 status_t err = writeInt32(size); 349 if (err != NO_ERROR) { 350 return err; 351 } 352 } 353 if (size) { 354 void* buffer = writeInplace(size); 355 if (buffer == NULL) 356 return NO_MEMORY; 357 return val.flatten(buffer, size); 358 } 359 return NO_ERROR; 360 } 361 362 template<typename T> 363 status_t Parcel::read(Flattenable<T>& val) const { 364 FlattenableHelper<T> helper(val); 365 return read(helper); 366 } 367 368 template<typename T> 369 status_t Parcel::read(LightFlattenable<T>& val) const { 370 size_t size; 371 if (val.isFixedSize()) { 372 size = val.getFlattenedSize(); 373 } else { 374 int32_t s; 375 status_t err = readInt32(&s); 376 if (err != NO_ERROR) { 377 return err; 378 } 379 size = s; 380 } 381 if (size) { 382 void const* buffer = readInplace(size); 383 return buffer == NULL ? NO_MEMORY : 384 val.unflatten(buffer, size); 385 } 386 return NO_ERROR; 387 } 388 389 // --------------------------------------------------------------------------- 390 391 inline TextOutput& operator<<(TextOutput& to, const Parcel& parcel) 392 { 393 parcel.print(to); 394 return to; 395 } 396 397 // --------------------------------------------------------------------------- 398 399 // Generic acquire and release of objects. 400 void acquire_object(const sp<ProcessState>& proc, 401 const flat_binder_object& obj, const void* who); 402 void release_object(const sp<ProcessState>& proc, 403 const flat_binder_object& obj, const void* who); 404 405 void flatten_binder(const sp<ProcessState>& proc, 406 const sp<IBinder>& binder, flat_binder_object* out); 407 void flatten_binder(const sp<ProcessState>& proc, 408 const wp<IBinder>& binder, flat_binder_object* out); 409 status_t unflatten_binder(const sp<ProcessState>& proc, 410 const flat_binder_object& flat, sp<IBinder>* out); 411 status_t unflatten_binder(const sp<ProcessState>& proc, 412 const flat_binder_object& flat, wp<IBinder>* out); 413 414 }; // namespace android 415 416 // --------------------------------------------------------------------------- 417 418 #endif // ANDROID_PARCEL_H 419
