1 /*
2 * Copyright 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 "SharedMemoryParcelable"
18 //#define LOG_NDEBUG 0
19 #include <utils/Log.h>
20
21 #include <stdint.h>
22 #include <stdio.h>
23
24 #include <sys/mman.h>
25 #include <aaudio/AAudio.h>
26
27 #include <android-base/unique_fd.h>
28 #include <binder/Parcelable.h>
29 #include <utility/AAudioUtilities.h>
30
31 #include "binding/SharedMemoryParcelable.h"
32
33 using android::base::unique_fd;
34 using android::NO_ERROR;
35 using android::status_t;
36 using android::Parcel;
37 using android::Parcelable;
38
39 using namespace aaudio;
40
SharedMemoryParcelable()41 SharedMemoryParcelable::SharedMemoryParcelable() {}
~SharedMemoryParcelable()42 SharedMemoryParcelable::~SharedMemoryParcelable() {};
43
setup(const unique_fd & fd,int32_t sizeInBytes)44 void SharedMemoryParcelable::setup(const unique_fd& fd, int32_t sizeInBytes) {
45 mFd.reset(dup(fd.get())); // store a duplicate fd
46 ALOGV("setup(fd = %d -> %d, size = %d) this = %p\n", fd.get(), mFd.get(), sizeInBytes, this);
47 mSizeInBytes = sizeInBytes;
48 }
49
writeToParcel(Parcel * parcel) const50 status_t SharedMemoryParcelable::writeToParcel(Parcel* parcel) const {
51 status_t status = AAudioConvert_aaudioToAndroidStatus(validate());
52 if (status != NO_ERROR) return status;
53
54 status = parcel->writeInt32(mSizeInBytes);
55 if (status != NO_ERROR) return status;
56 if (mSizeInBytes > 0) {
57 ALOGV("writeToParcel() mFd = %d, this = %p\n", mFd.get(), this);
58 status = parcel->writeUniqueFileDescriptor(mFd);
59 ALOGE_IF(status != NO_ERROR, "SharedMemoryParcelable writeDupFileDescriptor failed : %d",
60 status);
61 }
62 return status;
63 }
64
readFromParcel(const Parcel * parcel)65 status_t SharedMemoryParcelable::readFromParcel(const Parcel* parcel) {
66 status_t status = parcel->readInt32(&mSizeInBytes);
67 if (status != NO_ERROR) goto error;
68
69 if (mSizeInBytes > 0) {
70 // The Parcel owns the file descriptor and will close it later.
71 unique_fd mmapFd;
72 status = parcel->readUniqueFileDescriptor(&mmapFd);
73 if (status != NO_ERROR) {
74 ALOGE("readFromParcel() readUniqueFileDescriptor() failed : %d", status);
75 goto error;
76 }
77
78 // Resolve the memory now while we still have the FD from the Parcel.
79 // Closing the FD will not affect the shared memory once mmap() has been called.
80 aaudio_result_t result = resolveSharedMemory(mmapFd);
81 status = AAudioConvert_aaudioToAndroidStatus(result);
82 if (status != NO_ERROR) goto error;
83 }
84
85 return AAudioConvert_aaudioToAndroidStatus(validate());
86
87 error:
88 return status;
89 }
90
close()91 aaudio_result_t SharedMemoryParcelable::close() {
92 if (mResolvedAddress != MMAP_UNRESOLVED_ADDRESS) {
93 int err = munmap(mResolvedAddress, mSizeInBytes);
94 if (err < 0) {
95 ALOGE("close() munmap() failed %d", err);
96 return AAudioConvert_androidToAAudioResult(err);
97 }
98 mResolvedAddress = MMAP_UNRESOLVED_ADDRESS;
99 }
100 return AAUDIO_OK;
101 }
102
resolveSharedMemory(const unique_fd & fd)103 aaudio_result_t SharedMemoryParcelable::resolveSharedMemory(const unique_fd& fd) {
104 mResolvedAddress = (uint8_t *) mmap(0, mSizeInBytes, PROT_READ | PROT_WRITE,
105 MAP_SHARED, fd.get(), 0);
106 if (mResolvedAddress == MMAP_UNRESOLVED_ADDRESS) {
107 ALOGE("mmap() failed for fd = %d, nBytes = %d, errno = %s",
108 fd.get(), mSizeInBytes, strerror(errno));
109 return AAUDIO_ERROR_INTERNAL;
110 }
111 return AAUDIO_OK;
112 }
113
resolve(int32_t offsetInBytes,int32_t sizeInBytes,void ** regionAddressPtr)114 aaudio_result_t SharedMemoryParcelable::resolve(int32_t offsetInBytes, int32_t sizeInBytes,
115 void **regionAddressPtr) {
116 if (offsetInBytes < 0) {
117 ALOGE("illegal offsetInBytes = %d", offsetInBytes);
118 return AAUDIO_ERROR_OUT_OF_RANGE;
119 } else if ((offsetInBytes + sizeInBytes) > mSizeInBytes) {
120 ALOGE("out of range, offsetInBytes = %d, "
121 "sizeInBytes = %d, mSizeInBytes = %d",
122 offsetInBytes, sizeInBytes, mSizeInBytes);
123 return AAUDIO_ERROR_OUT_OF_RANGE;
124 }
125
126 aaudio_result_t result = AAUDIO_OK;
127
128 if (mResolvedAddress == MMAP_UNRESOLVED_ADDRESS) {
129 if (mFd.get() != -1) {
130 result = resolveSharedMemory(mFd);
131 } else {
132 ALOGE("has no file descriptor for shared memory.");
133 result = AAUDIO_ERROR_INTERNAL;
134 }
135 }
136
137 if (result == AAUDIO_OK && mResolvedAddress != MMAP_UNRESOLVED_ADDRESS) {
138 *regionAddressPtr = mResolvedAddress + offsetInBytes;
139 ALOGV("mResolvedAddress = %p", mResolvedAddress);
140 ALOGV("offset by %d, *regionAddressPtr = %p", offsetInBytes, *regionAddressPtr);
141 }
142 return result;
143 }
144
getSizeInBytes()145 int32_t SharedMemoryParcelable::getSizeInBytes() {
146 return mSizeInBytes;
147 }
148
validate() const149 aaudio_result_t SharedMemoryParcelable::validate() const {
150 if (mSizeInBytes < 0 || mSizeInBytes >= MAX_MMAP_SIZE_BYTES) {
151 ALOGE("invalid mSizeInBytes = %d", mSizeInBytes);
152 return AAUDIO_ERROR_OUT_OF_RANGE;
153 }
154 return AAUDIO_OK;
155 }
156
dump()157 void SharedMemoryParcelable::dump() {
158 ALOGD("mFd = %d", mFd.get());
159 ALOGD("mSizeInBytes = %d", mSizeInBytes);
160 }
161