Parcel.h revision 84e625ac1e01f5a9c3ed16664da6498212ed662b
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// --------------------------------------------------------------------------- 29namespace android { 30 31template <typename T> class Flattenable; 32template <typename T> class LightFlattenable; 33class IBinder; 34class IPCThreadState; 35class ProcessState; 36class String8; 37class TextOutput; 38 39class Parcel { 40 friend class IPCThreadState; 41public: 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 84private: 85 const binder_size_t* objects() const; 86 87public: 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 writeIntPtr(intptr_t val); 101 status_t writeCString(const char* str); 102 status_t writeString8(const String8& str); 103 status_t writeString16(const String16& str); 104 status_t writeString16(const char16_t* str, size_t len); 105 status_t writeStrongBinder(const sp<IBinder>& val); 106 status_t writeWeakBinder(const wp<IBinder>& val); 107 status_t writeInt32Array(size_t len, const int32_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 blob to the parcel. 132 // If the blob is small, then it is stored in-place, otherwise it is 133 // transferred by way of an anonymous shared memory region. 134 // The caller should call release() on the blob after writing its contents. 135 status_t writeBlob(size_t len, WritableBlob* outBlob); 136 137 status_t writeObject(const flat_binder_object& val, bool nullMetaData); 138 139 // Like Parcel.java's writeNoException(). Just writes a zero int32. 140 // Currently the native implementation doesn't do any of the StrictMode 141 // stack gathering and serialization that the Java implementation does. 142 status_t writeNoException(); 143 144 void remove(size_t start, size_t amt); 145 146 status_t read(void* outData, size_t len) const; 147 const void* readInplace(size_t len) const; 148 int32_t readInt32() const; 149 status_t readInt32(int32_t *pArg) const; 150 int64_t readInt64() const; 151 status_t readInt64(int64_t *pArg) const; 152 float readFloat() const; 153 status_t readFloat(float *pArg) const; 154 double readDouble() const; 155 status_t readDouble(double *pArg) const; 156 intptr_t readIntPtr() const; 157 status_t readIntPtr(intptr_t *pArg) const; 158 159 const char* readCString() const; 160 String8 readString8() const; 161 String16 readString16() const; 162 const char16_t* readString16Inplace(size_t* outLen) const; 163 sp<IBinder> readStrongBinder() const; 164 wp<IBinder> readWeakBinder() const; 165 166 template<typename T> 167 status_t read(Flattenable<T>& val) const; 168 169 template<typename T> 170 status_t read(LightFlattenable<T>& val) const; 171 172 // Like Parcel.java's readExceptionCode(). Reads the first int32 173 // off of a Parcel's header, returning 0 or the negative error 174 // code on exceptions, but also deals with skipping over rich 175 // response headers. Callers should use this to read & parse the 176 // response headers rather than doing it by hand. 177 int32_t readExceptionCode() const; 178 179 // Retrieve native_handle from the parcel. This returns a copy of the 180 // parcel's native_handle (the caller takes ownership). The caller 181 // must free the native_handle with native_handle_close() and 182 // native_handle_delete(). 183 native_handle* readNativeHandle() const; 184 185 186 // Retrieve a file descriptor from the parcel. This returns the raw fd 187 // in the parcel, which you do not own -- use dup() to get your own copy. 188 int readFileDescriptor() const; 189 190 // Reads a blob from the parcel. 191 // The caller should call release() on the blob after reading its contents. 192 status_t readBlob(size_t len, ReadableBlob* outBlob) const; 193 194 const flat_binder_object* readObject(bool nullMetaData) const; 195 196 // Explicitly close all file descriptors in the parcel. 197 void closeFileDescriptors(); 198 199private: 200 typedef void (*release_func)(Parcel* parcel, 201 const uint8_t* data, size_t dataSize, 202 const binder_size_t* objects, size_t objectsSize, 203 void* cookie); 204 205 uintptr_t ipcData() const; 206 size_t ipcDataSize() const; 207 uintptr_t ipcObjects() const; 208 size_t ipcObjectsCount() const; 209 void ipcSetDataReference(const uint8_t* data, size_t dataSize, 210 const binder_size_t* objects, size_t objectsCount, 211 release_func relFunc, void* relCookie); 212 213public: 214 void print(TextOutput& to, uint32_t flags = 0) const; 215 216private: 217 Parcel(const Parcel& o); 218 Parcel& operator=(const Parcel& o); 219 220 status_t finishWrite(size_t len); 221 void releaseObjects(); 222 void acquireObjects(); 223 status_t growData(size_t len); 224 status_t restartWrite(size_t desired); 225 status_t continueWrite(size_t desired); 226 status_t writePointer(uintptr_t val); 227 status_t readPointer(uintptr_t *pArg) const; 228 uintptr_t readPointer() const; 229 void freeDataNoInit(); 230 void initState(); 231 void scanForFds() const; 232 233 template<class T> 234 status_t readAligned(T *pArg) const; 235 236 template<class T> T readAligned() const; 237 238 template<class T> 239 status_t writeAligned(T val); 240 241 status_t mError; 242 uint8_t* mData; 243 size_t mDataSize; 244 size_t mDataCapacity; 245 mutable size_t mDataPos; 246 binder_size_t* mObjects; 247 size_t mObjectsSize; 248 size_t mObjectsCapacity; 249 mutable size_t mNextObjectHint; 250 251 mutable bool mFdsKnown; 252 mutable bool mHasFds; 253 bool mAllowFds; 254 255 release_func mOwner; 256 void* mOwnerCookie; 257 258 class Blob { 259 public: 260 Blob(); 261 ~Blob(); 262 263 void release(); 264 inline size_t size() const { return mSize; } 265 266 protected: 267 void init(bool mapped, void* data, size_t size); 268 void clear(); 269 270 bool mMapped; 271 void* mData; 272 size_t mSize; 273 }; 274 275 class FlattenableHelperInterface { 276 protected: 277 ~FlattenableHelperInterface() { } 278 public: 279 virtual size_t getFlattenedSize() const = 0; 280 virtual size_t getFdCount() const = 0; 281 virtual status_t flatten(void* buffer, size_t size, int* fds, size_t count) const = 0; 282 virtual status_t unflatten(void const* buffer, size_t size, int const* fds, size_t count) = 0; 283 }; 284 285 template<typename T> 286 class FlattenableHelper : public FlattenableHelperInterface { 287 friend class Parcel; 288 const Flattenable<T>& val; 289 explicit FlattenableHelper(const Flattenable<T>& val) : val(val) { } 290 291 public: 292 virtual size_t getFlattenedSize() const { 293 return val.getFlattenedSize(); 294 } 295 virtual size_t getFdCount() const { 296 return val.getFdCount(); 297 } 298 virtual status_t flatten(void* buffer, size_t size, int* fds, size_t count) const { 299 return val.flatten(buffer, size, fds, count); 300 } 301 virtual status_t unflatten(void const* buffer, size_t size, int const* fds, size_t count) { 302 return const_cast<Flattenable<T>&>(val).unflatten(buffer, size, fds, count); 303 } 304 }; 305 status_t write(const FlattenableHelperInterface& val); 306 status_t read(FlattenableHelperInterface& val) const; 307 308public: 309 class ReadableBlob : public Blob { 310 friend class Parcel; 311 public: 312 inline const void* data() const { return mData; } 313 }; 314 315 class WritableBlob : public Blob { 316 friend class Parcel; 317 public: 318 inline void* data() { return mData; } 319 }; 320}; 321 322// --------------------------------------------------------------------------- 323 324template<typename T> 325status_t Parcel::write(const Flattenable<T>& val) { 326 const FlattenableHelper<T> helper(val); 327 return write(helper); 328} 329 330template<typename T> 331status_t Parcel::write(const LightFlattenable<T>& val) { 332 size_t size(val.getFlattenedSize()); 333 if (!val.isFixedSize()) { 334 status_t err = writeInt32(size); 335 if (err != NO_ERROR) { 336 return err; 337 } 338 } 339 if (size) { 340 void* buffer = writeInplace(size); 341 if (buffer == NULL) 342 return NO_MEMORY; 343 return val.flatten(buffer, size); 344 } 345 return NO_ERROR; 346} 347 348template<typename T> 349status_t Parcel::read(Flattenable<T>& val) const { 350 FlattenableHelper<T> helper(val); 351 return read(helper); 352} 353 354template<typename T> 355status_t Parcel::read(LightFlattenable<T>& val) const { 356 size_t size; 357 if (val.isFixedSize()) { 358 size = val.getFlattenedSize(); 359 } else { 360 int32_t s; 361 status_t err = readInt32(&s); 362 if (err != NO_ERROR) { 363 return err; 364 } 365 size = s; 366 } 367 if (size) { 368 void const* buffer = readInplace(size); 369 return buffer == NULL ? NO_MEMORY : 370 val.unflatten(buffer, size); 371 } 372 return NO_ERROR; 373} 374 375// --------------------------------------------------------------------------- 376 377inline TextOutput& operator<<(TextOutput& to, const Parcel& parcel) 378{ 379 parcel.print(to); 380 return to; 381} 382 383// --------------------------------------------------------------------------- 384 385// Generic acquire and release of objects. 386void acquire_object(const sp<ProcessState>& proc, 387 const flat_binder_object& obj, const void* who); 388void release_object(const sp<ProcessState>& proc, 389 const flat_binder_object& obj, const void* who); 390 391void flatten_binder(const sp<ProcessState>& proc, 392 const sp<IBinder>& binder, flat_binder_object* out); 393void flatten_binder(const sp<ProcessState>& proc, 394 const wp<IBinder>& binder, flat_binder_object* out); 395status_t unflatten_binder(const sp<ProcessState>& proc, 396 const flat_binder_object& flat, sp<IBinder>* out); 397status_t unflatten_binder(const sp<ProcessState>& proc, 398 const flat_binder_object& flat, wp<IBinder>* out); 399 400}; // namespace android 401 402// --------------------------------------------------------------------------- 403 404#endif // ANDROID_PARCEL_H 405