blob: 246cb2416a448ea9b1699c152a441d713aa6367d [file] [log] [blame]
/*
* Copyright (C) 2020 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "media/ShmemCompat.h"
#include "binder/MemoryBase.h"
#include "binder/MemoryHeapBase.h"
#include "media/ShmemUtil.h"
namespace android {
namespace media {
bool convertSharedFileRegionToIMemory(const SharedFileRegion& shmem,
sp<IMemory>* result) {
assert(result != nullptr);
if (!validateSharedFileRegion(shmem)) {
return false;
}
// Heap offset and size must be page aligned.
const size_t pageSize = getpagesize();
const size_t pageMask = ~(pageSize - 1);
// OK if this wraps.
const uint64_t endOffset = static_cast<uint64_t>(shmem.offset) +
static_cast<uint64_t>(shmem.size);
// Round down to page boundary.
const uint64_t heapStartOffset = shmem.offset & pageMask;
// Round up to page boundary.
const uint64_t heapEndOffset = (endOffset + pageSize - 1) & pageMask;
const uint64_t heapSize = heapEndOffset - heapStartOffset;
if (heapStartOffset > std::numeric_limits<size_t>::max() ||
heapSize > std::numeric_limits<size_t>::max()) {
return false;
}
uint32_t flags = !shmem.writeable ? IMemoryHeap::READ_ONLY : 0;
const sp<MemoryHeapBase> heap =
new MemoryHeapBase(shmem.fd.get(), heapSize, flags, heapStartOffset);
*result = sp<MemoryBase>::make(heap,
shmem.offset - heapStartOffset,
shmem.size);
return true;
}
bool convertIMemoryToSharedFileRegion(const sp<IMemory>& mem,
SharedFileRegion* result) {
assert(mem != nullptr);
assert(result != nullptr);
*result = SharedFileRegion();
ssize_t offset;
size_t size;
sp<IMemoryHeap> heap = mem->getMemory(&offset, &size);
if (size > 0) {
if (heap == nullptr) {
return false;
}
// Make sure the offset and size do not overflow from int64 boundaries.
if (size > std::numeric_limits<int64_t>::max() ||
offset > std::numeric_limits<int64_t>::max() ||
heap->getOffset() > std::numeric_limits<int64_t>::max() ||
static_cast<uint64_t>(heap->getOffset()) +
static_cast<uint64_t>(offset)
> std::numeric_limits<int64_t>::max()) {
return false;
}
const int fd = fcntl(heap->getHeapID(), F_DUPFD_CLOEXEC, 0);
if (fd < 0) {
return false;
}
result->fd.reset(base::unique_fd(fd));
result->size = size;
result->offset = heap->getOffset() + offset;
result->writeable = (heap->getFlags() & IMemoryHeap::READ_ONLY) == 0;
}
return true;
}
bool convertNullableSharedFileRegionToIMemory(const std::optional<SharedFileRegion>& shmem,
sp<IMemory>* result) {
assert(result != nullptr);
if (!shmem.has_value()) {
result->clear();
return true;
}
return convertSharedFileRegionToIMemory(shmem.value(), result);
}
bool convertNullableIMemoryToSharedFileRegion(const sp<IMemory>& mem,
std::optional<SharedFileRegion>* result) {
assert(result != nullptr);
if (mem == nullptr) {
result->reset();
return true;
}
result->emplace();
return convertIMemoryToSharedFileRegion(mem, &result->value());
}
} // namespace media
} // namespace android