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https://github.com/google/sandboxed-api.git
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dbaf95c724
This change should make it less confusing where utility code comes from. Having it in two places made sense when we were debating whether to publish Sandbox2 separately, but not any longer. Follow-up changes will move `sandbox2/util.h` and rename the remaining `sandbox2/util` folder. PiperOrigin-RevId: 351601640 Change-Id: I6256845261f610e590c25e2c59851cc51da2d778
81 lines
2.3 KiB
C++
81 lines
2.3 KiB
C++
// Copyright 2019 Google LLC
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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#include "sandboxed_api/sandbox2/buffer.h"
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#include <sys/mman.h>
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#include <sys/stat.h>
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#include <unistd.h>
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#include <cerrno>
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#include "absl/memory/memory.h"
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#include "absl/status/statusor.h"
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#include "absl/strings/str_cat.h"
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#include "sandboxed_api/sandbox2/util.h"
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#include "sandboxed_api/util/strerror.h"
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namespace sandbox2 {
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using ::sapi::StrError;
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// Creates a new Buffer that is backed by the specified file descriptor.
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absl::StatusOr<std::unique_ptr<Buffer>> Buffer::CreateFromFd(int fd) {
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auto buffer = absl::WrapUnique(new Buffer{});
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struct stat stat_buf;
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if (fstat(fd, &stat_buf) != 0) {
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return absl::InternalError(
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absl::StrCat("Could not stat buffer fd: ", StrError(errno)));
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}
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size_t size = stat_buf.st_size;
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int prot = PROT_READ | PROT_WRITE;
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int flags = MAP_SHARED;
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off_t offset = 0;
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buffer->buf_ =
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reinterpret_cast<uint8_t*>(mmap(nullptr, size, prot, flags, fd, offset));
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if (buffer->buf_ == MAP_FAILED) {
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return absl::InternalError(
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absl::StrCat("Could not map buffer fd: ", StrError(errno)));
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}
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buffer->fd_ = fd;
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buffer->size_ = size;
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return std::move(buffer); // GCC 7 needs the move (C++ DR #1579)
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}
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// Creates a new Buffer of the specified size, backed by a temporary file that
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// will be immediately deleted.
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absl::StatusOr<std::unique_ptr<Buffer>> Buffer::CreateWithSize(size_t size) {
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int fd;
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if (!util::CreateMemFd(&fd)) {
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return absl::InternalError("Could not create buffer temp file");
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}
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if (ftruncate(fd, size) != 0) {
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return absl::InternalError(
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absl::StrCat("Could not extend buffer fd: ", StrError(errno)));
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}
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return CreateFromFd(fd);
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}
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Buffer::~Buffer() {
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if (buf_ != nullptr) {
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munmap(buf_, size_);
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}
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if (fd_ != -1) {
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close(fd_);
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}
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}
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} // namespace sandbox2
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