HidlBinderSupport.cpp revision 9d3eb357a2a3a64baa4824d550b5563b3dc0b15a 
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// C includes
22#include <unistd.h>
23
24// C++ includes
25#include <fstream>
26#include <sstream>
27
28namespace android {
29namespace hardware {
30
31const size_t hidl_memory::kOffsetOfHandle = offsetof(hidl_memory, mHandle);
32const size_t hidl_memory::kOffsetOfName = offsetof(hidl_memory, mName);
33static_assert(hidl_memory::kOffsetOfHandle == 0, "wrong offset");
34static_assert(hidl_memory::kOffsetOfName == 24, "wrong offset");
35
36status_t readEmbeddedFromParcel(const hidl_memory& memory,
37        const Parcel &parcel, size_t parentHandle, size_t parentOffset) {
38    const native_handle_t *handle;
39    ::android::status_t _hidl_err = parcel.readNullableEmbeddedNativeHandle(
40            parentHandle,
41            parentOffset + hidl_memory::kOffsetOfHandle,
42            &handle);
43
44    if (_hidl_err == ::android::OK) {
45        _hidl_err = readEmbeddedFromParcel(
46                memory.name(),
47                parcel,
48                parentHandle,
49                parentOffset + hidl_memory::kOffsetOfName);
50    }
51
52    return _hidl_err;
53}
54
55status_t writeEmbeddedToParcel(const hidl_memory &memory,
56        Parcel *parcel, size_t parentHandle, size_t parentOffset) {
57    status_t _hidl_err = parcel->writeEmbeddedNativeHandle(
58            memory.handle(),
59            parentHandle,
60            parentOffset + hidl_memory::kOffsetOfHandle);
61
62    if (_hidl_err == ::android::OK) {
63        _hidl_err = writeEmbeddedToParcel(
64            memory.name(),
65            parcel,
66            parentHandle,
67            parentOffset + hidl_memory::kOffsetOfName);
68    }
69
70    return _hidl_err;
71}
72// static
73const size_t hidl_string::kOffsetOfBuffer = offsetof(hidl_string, mBuffer);
74static_assert(hidl_string::kOffsetOfBuffer == 0, "wrong offset");
75
76status_t readEmbeddedFromParcel(const hidl_string &string ,
77        const Parcel &parcel, size_t parentHandle, size_t parentOffset) {
78    const void *out;
79
80    status_t status = parcel.readEmbeddedBuffer(
81            string.size() + 1,
82            nullptr /* buffer_handle */,
83            parentHandle,
84            parentOffset + hidl_string::kOffsetOfBuffer,
85            &out);
86
87    if (status != OK) {
88        return status;
89    }
90
91    // Always safe to access out[string.size()] because we read size+1 bytes
92    if (static_cast<const char *>(out)[string.size()] != '\0') {
93        ALOGE("Received unterminated hidl_string buffer.");
94        return BAD_VALUE;
95    }
96
97    return OK;
98}
99
100status_t writeEmbeddedToParcel(const hidl_string &string,
101        Parcel *parcel, size_t parentHandle, size_t parentOffset) {
102    return parcel->writeEmbeddedBuffer(
103            string.c_str(),
104            string.size() + 1,
105            nullptr /* handle */,
106            parentHandle,
107            parentOffset + hidl_string::kOffsetOfBuffer);
108}
109
110android::status_t writeToParcel(const hidl_version &version, android::hardware::Parcel& parcel) {
111    return parcel.writeUint32(static_cast<uint32_t>(version.get_major()) << 16 | version.get_minor());
112}
113
114hidl_version* readFromParcel(const android::hardware::Parcel& parcel) {
115    uint32_t version;
116    android::status_t status = parcel.readUint32(&version);
117    if (status != OK) {
118        return nullptr;
119    } else {
120        return new hidl_version(version >> 16, version & 0xFFFF);
121    }
122}
123
124status_t readFromParcel(Status *s, const Parcel& parcel) {
125    int32_t exception;
126    status_t status = parcel.readInt32(&exception);
127    if (status != OK) {
128        s->setFromStatusT(status);
129        return status;
130    }
131
132    // Skip over fat response headers.  Not used (or propagated) in native code.
133    if (exception == Status::EX_HAS_REPLY_HEADER) {
134        // Note that the header size includes the 4 byte size field.
135        const int32_t header_start = parcel.dataPosition();
136        int32_t header_size;
137        status = parcel.readInt32(&header_size);
138        if (status != OK) {
139            s->setFromStatusT(status);
140            return status;
141        }
142        parcel.setDataPosition(header_start + header_size);
143        // And fat response headers are currently only used when there are no
144        // exceptions, so act like there was no error.
145        exception = Status::EX_NONE;
146    }
147
148    if (exception == Status::EX_NONE) {
149        *s = Status::ok();
150        return status;
151    }
152
153    // The remote threw an exception.  Get the message back.
154    String16 message;
155    status = parcel.readString16(&message);
156    if (status != OK) {
157        s->setFromStatusT(status);
158        return status;
159    }
160
161    s->setException(exception, String8(message));
162
163    return status;
164}
165
166status_t writeToParcel(const Status &s, Parcel* parcel) {
167    // Something really bad has happened, and we're not going to even
168    // try returning rich error data.
169    if (s.exceptionCode() == Status::EX_TRANSACTION_FAILED) {
170        return s.transactionError();
171    }
172
173    status_t status = parcel->writeInt32(s.exceptionCode());
174    if (status != OK) { return status; }
175    if (s.exceptionCode() == Status::EX_NONE) {
176        // We have no more information to write.
177        return status;
178    }
179    status = parcel->writeString16(String16(s.exceptionMessage()));
180    return status;
181}
182
183void configureBinderRpcThreadpool(size_t maxThreads, bool callerWillJoin) {
184    ProcessState::self()->setThreadPoolConfiguration(maxThreads, callerWillJoin /*callerJoinsPool*/);
185}
186
187void joinBinderRpcThreadpool() {
188    IPCThreadState::self()->joinThreadPool();
189}
190
191}  // namespace hardware
192}  // namespace android
193