HidlBinderSupport.cpp revision 3079100878a2595be644d866e67c12a9de620fd5 
1/*
2 * Copyright (C) 2016 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#define LOG_TAG "HidlSupport"
18
19#include <hidl/HidlBinderSupport.h>
20
21#ifdef LIBHIDL_TARGET_DEBUGGABLE
22#include <android-base/logging.h>
23#endif
24
25namespace android {
26namespace hardware {
27
28std::map<std::string, std::function<sp<IBinder>(void*)>> gBnConstructorMap{};
29
30const size_t hidl_memory::kOffsetOfHandle = offsetof(hidl_memory, mHandle);
31const size_t hidl_memory::kOffsetOfName = offsetof(hidl_memory, mName);
32
33status_t readEmbeddedFromParcel(hidl_memory * /* memory */,
34        const Parcel &parcel, size_t parentHandle, size_t parentOffset) {
35    ::android::status_t _hidl_err = ::android::OK;
36    const native_handle_t *_hidl_memory_handle = parcel.readEmbeddedNativeHandle(
37            parentHandle,
38            parentOffset + hidl_memory::kOffsetOfHandle);
39
40    if (_hidl_memory_handle == nullptr) {
41        _hidl_err = ::android::UNKNOWN_ERROR;
42        return _hidl_err;
43    }
44
45    _hidl_err = readEmbeddedFromParcel(
46            (hidl_string*) nullptr,
47            parcel,
48            parentHandle,
49            parentOffset + hidl_memory::kOffsetOfName);
50
51    return _hidl_err;
52}
53
54status_t writeEmbeddedToParcel(const hidl_memory &memory,
55        Parcel *parcel, size_t parentHandle, size_t parentOffset) {
56    status_t _hidl_err = parcel->writeEmbeddedNativeHandle(
57            memory.handle(),
58            parentHandle,
59            parentOffset + hidl_memory::kOffsetOfHandle);
60
61    if (_hidl_err == ::android::OK) {
62        _hidl_err = writeEmbeddedToParcel(
63            memory.name(),
64            parcel,
65            parentHandle,
66            parentOffset + hidl_memory::kOffsetOfName);
67    }
68
69    return _hidl_err;
70}
71// static
72const size_t hidl_string::kOffsetOfBuffer = offsetof(hidl_string, mBuffer);
73
74status_t readEmbeddedFromParcel(hidl_string * /* string */,
75        const Parcel &parcel, size_t parentHandle, size_t parentOffset) {
76    const void *ptr = parcel.readEmbeddedBuffer(
77            nullptr /* buffer_handle */,
78            parentHandle,
79            parentOffset + hidl_string::kOffsetOfBuffer);
80
81    return ptr != NULL ? OK : UNKNOWN_ERROR;
82}
83
84status_t writeEmbeddedToParcel(const hidl_string &string,
85        Parcel *parcel, size_t parentHandle, size_t parentOffset) {
86    return parcel->writeEmbeddedBuffer(
87            string.c_str(),
88            string.size() + 1,
89            nullptr /* handle */,
90            parentHandle,
91            parentOffset + hidl_string::kOffsetOfBuffer);
92}
93
94android::status_t writeToParcel(const hidl_version &version, android::hardware::Parcel& parcel) {
95    return parcel.writeUint32(static_cast<uint32_t>(version.get_major()) << 16 | version.get_minor());
96}
97
98hidl_version* readFromParcel(const android::hardware::Parcel& parcel) {
99    uint32_t version;
100    android::status_t status = parcel.readUint32(&version);
101    if (status != OK) {
102        return nullptr;
103    } else {
104        return new hidl_version(version >> 16, version & 0xFFFF);
105    }
106}
107
108status_t readFromParcel(Status *s, const Parcel& parcel) {
109    int32_t exception;
110    int32_t errorCode;
111    status_t status = parcel.readInt32(&exception);
112    if (status != OK) {
113        s->setFromStatusT(status);
114        return status;
115    }
116
117    // Skip over fat response headers.  Not used (or propagated) in native code.
118    if (exception == Status::EX_HAS_REPLY_HEADER) {
119        // Note that the header size includes the 4 byte size field.
120        const int32_t header_start = parcel.dataPosition();
121        int32_t header_size;
122        status = parcel.readInt32(&header_size);
123        if (status != OK) {
124            s->setFromStatusT(status);
125            return status;
126        }
127        parcel.setDataPosition(header_start + header_size);
128        // And fat response headers are currently only used when there are no
129        // exceptions, so act like there was no error.
130        exception = Status::EX_NONE;
131    }
132
133    if (exception == Status::EX_NONE) {
134        *s = Status::ok();
135        return status;
136    }
137
138    // The remote threw an exception.  Get the message back.
139    String16 message;
140    status = parcel.readString16(&message);
141    if (status != OK) {
142        s->setFromStatusT(status);
143        return status;
144    }
145
146    if (exception == Status::EX_SERVICE_SPECIFIC) {
147        status = parcel.readInt32(&errorCode);
148    }
149    if (status != OK) {
150        s->setFromStatusT(status);
151        return status;
152    }
153
154    if (exception == Status::EX_SERVICE_SPECIFIC) {
155        s->setServiceSpecificError(errorCode, String8(message));
156    } else {
157        s->setException(exception, String8(message));
158    }
159
160    return status;
161}
162
163status_t writeToParcel(const Status &s, Parcel* parcel) {
164    // Something really bad has happened, and we're not going to even
165    // try returning rich error data.
166    if (s.exceptionCode() == Status::EX_TRANSACTION_FAILED) {
167        return s.transactionError();
168    }
169
170    status_t status = parcel->writeInt32(s.exceptionCode());
171    if (status != OK) { return status; }
172    if (s.exceptionCode() == Status::EX_NONE) {
173        // We have no more information to write.
174        return status;
175    }
176    status = parcel->writeString16(String16(s.exceptionMessage()));
177    if (s.exceptionCode() != Status::EX_SERVICE_SPECIFIC) {
178        // We have no more information to write.
179        return status;
180    }
181    status = parcel->writeInt32(s.serviceSpecificErrorCode());
182    return status;
183}
184
185}  // namespace hardware
186}  // namespace android
187