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 private: 210 typedef void (*release_func)(Parcel* parcel, 211 const uint8_t* data, size_t dataSize, 212 const binder_size_t* objects, size_t objectsSize, 213 void* cookie); 214 215 uintptr_t ipcData() const; 216 size_t ipcDataSize() const; 217 uintptr_t ipcObjects() const; 218 size_t ipcObjectsCount() const; 219 void ipcSetDataReference(const uint8_t* data, size_t dataSize, 220 const binder_size_t* objects, size_t objectsCount, 221 release_func relFunc, void* relCookie); 222 223 public: 224 void print(TextOutput& to, uint32_t flags = 0) const; 225 226 private: 227 Parcel(const Parcel& o); 228 Parcel& operator=(const Parcel& o); 229 230 status_t finishWrite(size_t len); 231 void releaseObjects(); 232 void acquireObjects(); 233 status_t growData(size_t len); 234 status_t restartWrite(size_t desired); 235 status_t continueWrite(size_t desired); 236 status_t writePointer(uintptr_t val); 237 status_t readPointer(uintptr_t *pArg) const; 238 uintptr_t readPointer() const; 239 void freeDataNoInit(); 240 void initState(); 241 void scanForFds() const; 242 243 template<class T> 244 status_t readAligned(T *pArg) const; 245 246 template<class T> T readAligned() const; 247 248 template<class T> 249 status_t writeAligned(T val); 250 251 status_t mError; 252 uint8_t* mData; 253 size_t mDataSize; 254 size_t mDataCapacity; 255 mutable size_t mDataPos; 256 binder_size_t* mObjects; 257 size_t mObjectsSize; 258 size_t mObjectsCapacity; 259 mutable size_t mNextObjectHint; 260 261 mutable bool mFdsKnown; 262 mutable bool mHasFds; 263 bool mAllowFds; 264 265 release_func mOwner; 266 void* mOwnerCookie; 267 268 class Blob { 269 public: 270 Blob(); 271 ~Blob(); 272 273 void release(); 274 inline size_t size() const { return mSize; } 275 276 protected: 277 void init(bool mapped, void* data, size_t size); 278 void clear(); 279 280 bool mMapped; 281 void* mData; 282 size_t mSize; 283 }; 284 285 class FlattenableHelperInterface { 286 protected: 287 ~FlattenableHelperInterface() { } 288 public: 289 virtual size_t getFlattenedSize() const = 0; 290 virtual size_t getFdCount() const = 0; 291 virtual status_t flatten(void* buffer, size_t size, int* fds, size_t count) const = 0; 292 virtual status_t unflatten(void const* buffer, size_t size, int const* fds, size_t count) = 0; 293 }; 294 295 template<typename T> 296 class FlattenableHelper : public FlattenableHelperInterface { 297 friend class Parcel; 298 const Flattenable<T>& val; 299 explicit FlattenableHelper(const Flattenable<T>& val) : val(val) { } 300 301 public: 302 virtual size_t getFlattenedSize() const { 303 return val.getFlattenedSize(); 304 } 305 virtual size_t getFdCount() const { 306 return val.getFdCount(); 307 } 308 virtual status_t flatten(void* buffer, size_t size, int* fds, size_t count) const { 309 return val.flatten(buffer, size, fds, count); 310 } 311 virtual status_t unflatten(void const* buffer, size_t size, int const* fds, size_t count) { 312 return const_cast<Flattenable<T>&>(val).unflatten(buffer, size, fds, count); 313 } 314 }; 315 status_t write(const FlattenableHelperInterface& val); 316 status_t read(FlattenableHelperInterface& val) const; 317 318 public: 319 class ReadableBlob : public Blob { 320 friend class Parcel; 321 public: 322 inline const void* data() const { return mData; } 323 }; 324 325 class WritableBlob : public Blob { 326 friend class Parcel; 327 public: 328 inline void* data() { return mData; } 329 }; 330 }; 331 332 // --------------------------------------------------------------------------- 333 334 template<typename T> 335 status_t Parcel::write(const Flattenable<T>& val) { 336 const FlattenableHelper<T> helper(val); 337 return write(helper); 338 } 339 340 template<typename T> 341 status_t Parcel::write(const LightFlattenable<T>& val) { 342 size_t size(val.getFlattenedSize()); 343 if (!val.isFixedSize()) { 344 status_t err = writeInt32(size); 345 if (err != NO_ERROR) { 346 return err; 347 } 348 } 349 if (size) { 350 void* buffer = writeInplace(size); 351 if (buffer == NULL) 352 return NO_MEMORY; 353 return val.flatten(buffer, size); 354 } 355 return NO_ERROR; 356 } 357 358 template<typename T> 359 status_t Parcel::read(Flattenable<T>& val) const { 360 FlattenableHelper<T> helper(val); 361 return read(helper); 362 } 363 364 template<typename T> 365 status_t Parcel::read(LightFlattenable<T>& val) const { 366 size_t size; 367 if (val.isFixedSize()) { 368 size = val.getFlattenedSize(); 369 } else { 370 int32_t s; 371 status_t err = readInt32(&s); 372 if (err != NO_ERROR) { 373 return err; 374 } 375 size = s; 376 } 377 if (size) { 378 void const* buffer = readInplace(size); 379 return buffer == NULL ? NO_MEMORY : 380 val.unflatten(buffer, size); 381 } 382 return NO_ERROR; 383 } 384 385 // --------------------------------------------------------------------------- 386 387 inline TextOutput& operator<<(TextOutput& to, const Parcel& parcel) 388 { 389 parcel.print(to); 390 return to; 391 } 392 393 // --------------------------------------------------------------------------- 394 395 // Generic acquire and release of objects. 396 void acquire_object(const sp<ProcessState>& proc, 397 const flat_binder_object& obj, const void* who); 398 void release_object(const sp<ProcessState>& proc, 399 const flat_binder_object& obj, const void* who); 400 401 void flatten_binder(const sp<ProcessState>& proc, 402 const sp<IBinder>& binder, flat_binder_object* out); 403 void flatten_binder(const sp<ProcessState>& proc, 404 const wp<IBinder>& binder, flat_binder_object* out); 405 status_t unflatten_binder(const sp<ProcessState>& proc, 406 const flat_binder_object& flat, sp<IBinder>* out); 407 status_t unflatten_binder(const sp<ProcessState>& proc, 408 const flat_binder_object& flat, wp<IBinder>* out); 409 410 }; // namespace android 411 412 // --------------------------------------------------------------------------- 413 414 #endif // ANDROID_PARCEL_H 415
