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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_HARDWARE_PARCEL_H
18 #define ANDROID_HARDWARE_PARCEL_H
19 
20 #include <string>
21 #include <vector>
22 
23 #include <cutils/native_handle.h>
24 #include <utils/Errors.h>
25 #include <utils/RefBase.h>
26 #include <utils/String16.h>
27 
28 #include <linux/android/binder.h>
29 
30 #include <hwbinder/IInterface.h>
31 
32 struct binder_buffer_object;
33 
34 // ---------------------------------------------------------------------------
35 namespace android {
36 namespace hardware {
37 
38 class IBinder;
39 class IPCThreadState;
40 class ProcessState;
41 class TextOutput;
42 
43 class Parcel {
44     friend class IPCThreadState;
45 public:
46 
47                         Parcel();
48                         ~Parcel();
49 
50     const uint8_t*      data() const;
51     size_t              dataSize() const;
52     size_t              dataAvail() const;
53     size_t              dataPosition() const;
54     size_t              dataCapacity() const;
55 
56     status_t            setDataSize(size_t size);
57     void                setDataPosition(size_t pos) const;
58     status_t            setDataCapacity(size_t size);
59 
60     status_t            setData(const uint8_t* buffer, size_t len);
61 
62     // Writes the RPC header.
63     status_t            writeInterfaceToken(const char* interface);
64 
65     // Parses the RPC header, returning true if the interface name
66     // in the header matches the expected interface from the caller.
67     bool                enforceInterface(const char* interface) const;
68     bool                checkInterface(IBinder*) const;
69 
70     void                freeData();
71 
72 private:
73     const binder_size_t* objects() const;
74 
75 public:
76     size_t              objectsCount() const;
77 
78     status_t            errorCheck() const;
79     void                setError(status_t err);
80 
81     status_t            write(const void* data, size_t len);
82     void*               writeInplace(size_t len);
83     status_t            writeUnpadded(const void* data, size_t len);
84     status_t            writeInt8(int8_t val);
85     status_t            writeUint8(uint8_t val);
86     status_t            writeInt16(int16_t val);
87     status_t            writeUint16(uint16_t val);
88     status_t            writeInt32(int32_t val);
89     status_t            writeUint32(uint32_t val);
90     status_t            writeInt64(int64_t val);
91     status_t            writeUint64(uint64_t val);
92     status_t            writeFloat(float val);
93     status_t            writeDouble(double val);
94     status_t            writeCString(const char* str);
95     status_t            writeString16(const String16& str);
96     status_t            writeString16(const std::unique_ptr<String16>& str);
97     status_t            writeString16(const char16_t* str, size_t len);
98     status_t            writeStrongBinder(const sp<IBinder>& val);
99     status_t            writeWeakBinder(const wp<IBinder>& val);
100     status_t            writeBool(bool val);
101 
102     template<typename T>
103     status_t            writeObject(const T& val);
104 
105     status_t            writeBuffer(const void *buffer, size_t length, size_t *handle);
106     status_t            writeEmbeddedBuffer(const void *buffer, size_t length, size_t *handle,
107                             size_t parent_buffer_handle, size_t parent_offset);
108 public:
109     status_t            writeReference(size_t *handle,
110                                        size_t child_buffer_handle, size_t child_offset);
111     status_t            writeEmbeddedReference(size_t *handle,
112                                                size_t child_buffer_handle, size_t child_offset,
113                                                size_t parent_buffer_handle, size_t parent_offset);
114     status_t            writeNullReference(size_t *handle);
115     status_t            writeEmbeddedNullReference(size_t *handle,
116                                                    size_t parent_buffer_handle, size_t parent_offset);
117 
118 
119     status_t            writeEmbeddedNativeHandle(const native_handle_t *handle,
120                             size_t parent_buffer_handle, size_t parent_offset);
121     status_t            writeNativeHandleNoDup(const native_handle* handle, bool embedded,
122                                                size_t parent_buffer_handle = 0,
123                                                size_t parent_offset = 0);
124     status_t            writeNativeHandleNoDup(const native_handle* handle);
125 
126     void                remove(size_t start, size_t amt);
127 
128     status_t            read(void* outData, size_t len) const;
129     const void*         readInplace(size_t len) const;
130     status_t            readInt8(int8_t *pArg) const;
131     status_t            readUint8(uint8_t *pArg) const;
132     status_t            readInt16(int16_t *pArg) const;
133     status_t            readUint16(uint16_t *pArg) const;
134     int32_t             readInt32() const;
135     status_t            readInt32(int32_t *pArg) const;
136     uint32_t            readUint32() const;
137     status_t            readUint32(uint32_t *pArg) const;
138     int64_t             readInt64() const;
139     status_t            readInt64(int64_t *pArg) const;
140     uint64_t            readUint64() const;
141     status_t            readUint64(uint64_t *pArg) const;
142     float               readFloat() const;
143     status_t            readFloat(float *pArg) const;
144     double              readDouble() const;
145     status_t            readDouble(double *pArg) const;
146 
147     bool                readBool() const;
148     status_t            readBool(bool *pArg) const;
149     const char*         readCString() const;
150     String16            readString16() const;
151     status_t            readString16(String16* pArg) const;
152     status_t            readString16(std::unique_ptr<String16>* pArg) const;
153     const char16_t*     readString16Inplace(size_t* outLen) const;
154     sp<IBinder>         readStrongBinder() const;
155     status_t            readStrongBinder(sp<IBinder>* val) const;
156     status_t            readNullableStrongBinder(sp<IBinder>* val) const;
157     wp<IBinder>         readWeakBinder() const;
158 
159     template<typename T>
160     const T*            readObject(size_t *objects_offset = nullptr) const;
161 
162     status_t            readBuffer(size_t buffer_size, size_t *buffer_handle,
163                                    const void **buffer_out) const;
164     status_t            readNullableBuffer(size_t buffer_size, size_t *buffer_handle,
165                                            const void **buffer_out) const;
166     status_t            readEmbeddedBuffer(size_t buffer_size, size_t *buffer_handle,
167                                            size_t parent_buffer_handle, size_t parent_offset,
168                                            const void **buffer_out) const;
169     status_t            readNullableEmbeddedBuffer(size_t buffer_size,
170                                                    size_t *buffer_handle,
171                                                    size_t parent_buffer_handle,
172                                                    size_t parent_offset,
173                                                    const void **buffer_out) const;
174 
175     status_t            readReference(void const* *bufptr,
176                                       size_t *buffer_handle, bool *isRef) const;
177     status_t            readEmbeddedReference(void const* *bufptr, size_t *buffer_handle,
178                                               size_t parent_buffer_handle, size_t parent_offset,
179                                               bool *isRef) const;
180     status_t            readEmbeddedNativeHandle(size_t parent_buffer_handle,
181                            size_t parent_offset, const native_handle_t **handle) const;
182     status_t            readNullableEmbeddedNativeHandle(size_t parent_buffer_handle,
183                            size_t parent_offset, const native_handle_t **handle) const;
184     status_t            readNativeHandleNoDup(const native_handle_t **handle) const;
185     status_t            readNullableNativeHandleNoDup(const native_handle_t **handle) const;
186 
187     // Explicitly close all file descriptors in the parcel.
188     void                closeFileDescriptors();
189 
190     // Debugging: get metrics on current allocations.
191     static size_t       getGlobalAllocSize();
192     static size_t       getGlobalAllocCount();
193 
194 private:
195     // Below is a cache that records some information about all actual buffers
196     // in this parcel.
197     struct BufferInfo {
198         size_t index;
199         binder_uintptr_t buffer;
200         binder_uintptr_t bufend; // buffer + length
201     };
202     // value of mObjectSize when mBufCache is last updated.
203     mutable size_t                  mBufCachePos;
204     mutable std::vector<BufferInfo> mBufCache;
205     // clear mBufCachePos and mBufCache.
206     void                clearCache() const;
207     // update mBufCache for all objects between mBufCachePos and mObjectsSize
208     void                updateCache() const;
209 
210     bool                verifyBufferObject(const binder_buffer_object *buffer_obj,
211                                            size_t size, uint32_t flags, size_t parent,
212                                            size_t parentOffset) const;
213 
214     status_t            readBuffer(size_t buffer_size, size_t *buffer_handle,
215                                    uint32_t flags, size_t parent, size_t parentOffset,
216                                    const void **buffer_out) const;
217 
218     status_t            readNullableNativeHandleNoDup(const native_handle_t **handle,
219                                                       bool embedded,
220                                                       size_t parent_buffer_handle = 0,
221                                                       size_t parent_offset = 0) const;
222 public:
223 
224     // The following two methods attempt to find if a chunk of memory ("buffer")
225     // is written / read before (by (read|write)(Embedded)?Buffer methods. )
226     // 1. Call findBuffer if the chunk of memory could be a small part of a larger
227     //    buffer written before (for example, an element of a hidl_vec). The
228     //    method will also ensure that the end address (ptr + length) is also
229     //    within the buffer.
230     // 2. Call quickFindBuffer if the buffer could only be written previously
231     //    by itself (for example, the mBuffer field of a hidl_vec). No lengths
232     //    are checked.
233     status_t            findBuffer(const void *ptr,
234                                    size_t length,
235                                    bool *found,
236                                    size_t *handle,
237                                    size_t *offset // valid if found
238                                   ) const;
239     status_t            quickFindBuffer(const void *ptr,
240                                         size_t *handle // valid if found
241                                        ) const;
242 
243 private:
244     status_t            incrementNumReferences();
245     bool                validateBufferChild(size_t child_buffer_handle,
246                                             size_t child_offset) const;
247     bool                validateBufferParent(size_t parent_buffer_handle,
248                                              size_t parent_offset) const;
249 
250 private:
251     typedef void        (*release_func)(Parcel* parcel,
252                                         const uint8_t* data, size_t dataSize,
253                                         const binder_size_t* objects, size_t objectsSize,
254                                         void* cookie);
255 
256     uintptr_t           ipcData() const;
257     size_t              ipcDataSize() const;
258     uintptr_t           ipcObjects() const;
259     size_t              ipcObjectsCount() const;
260     size_t              ipcBufferSize() const;
261     void                ipcSetDataReference(const uint8_t* data, size_t dataSize,
262                                             const binder_size_t* objects, size_t objectsCount,
263                                             release_func relFunc, void* relCookie);
264 
265 public:
266     void                print(TextOutput& to, uint32_t flags = 0) const;
267 
268 private:
269                         Parcel(const Parcel& o);
270     Parcel&             operator=(const Parcel& o);
271 
272     status_t            finishWrite(size_t len);
273     void                releaseObjects();
274     void                acquireObjects();
275     status_t            growData(size_t len);
276     status_t            restartWrite(size_t desired);
277     status_t            continueWrite(size_t desired);
278     status_t            writePointer(uintptr_t val);
279     status_t            readPointer(uintptr_t *pArg) const;
280     uintptr_t           readPointer() const;
281     void                freeDataNoInit();
282     void                initState();
283     void                scanForFds() const;
284 
285     template<class T>
286     status_t            readAligned(T *pArg) const;
287 
288     template<class T>   T readAligned() const;
289 
290     template<class T>
291     status_t            writeAligned(T val);
292 
293     status_t            mError;
294     uint8_t*            mData;
295     size_t              mDataSize;
296     size_t              mDataCapacity;
297     mutable size_t      mDataPos;
298     binder_size_t*      mObjects;
299     size_t              mObjectsSize;
300     size_t              mObjectsCapacity;
301     mutable size_t      mNextObjectHint;
302     size_t              mNumRef;
303 
304     mutable bool        mFdsKnown;
305     mutable bool        mHasFds;
306     bool                mAllowFds;
307 
308     release_func        mOwner;
309     void*               mOwnerCookie;
310 };
311 // ---------------------------------------------------------------------------
312 
313 inline TextOutput& operator<<(TextOutput& to, const Parcel& parcel)
314 {
315     parcel.print(to);
316     return to;
317 }
318 
319 // ---------------------------------------------------------------------------
320 
321 // Generic acquire and release of objects.
322 void acquire_object(const sp<ProcessState>& proc,
323                     const flat_binder_object& obj, const void* who);
324 void release_object(const sp<ProcessState>& proc,
325                     const flat_binder_object& obj, const void* who);
326 
327 void flatten_binder(const sp<ProcessState>& proc,
328                     const sp<IBinder>& binder, flat_binder_object* out);
329 void flatten_binder(const sp<ProcessState>& proc,
330                     const wp<IBinder>& binder, flat_binder_object* out);
331 status_t unflatten_binder(const sp<ProcessState>& proc,
332                           const flat_binder_object& flat, sp<IBinder>* out);
333 status_t unflatten_binder(const sp<ProcessState>& proc,
334                           const flat_binder_object& flat, wp<IBinder>* out);
335 
336 }; // namespace hardware
337 }; // namespace android
338 
339 // ---------------------------------------------------------------------------
340 
341 #endif // ANDROID_HARDWARE_PARCEL_H
342