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content / browser / child_process_launcher_helper_posix.cc [blame]
// Copyright 2017 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "content/browser/child_process_launcher_helper_posix.h"
#include "base/check.h"
#include "base/command_line.h"
#include "base/functional/overloaded.h"
#include "base/metrics/field_trial.h"
#include "base/posix/global_descriptors.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/string_util.h"
#include "build/build_config.h"
#include "content/browser/posix_file_descriptor_info_impl.h"
#include "content/common/shared_file_util.h"
#include "content/public/browser/content_browser_client.h"
#include "content/public/common/content_client.h"
#include "content/public/common/content_descriptors.h"
#include "content/public/common/content_switches.h"
#include "mojo/public/cpp/platform/platform_channel_endpoint.h"
#include "third_party/abseil-cpp/absl/types/variant.h"
namespace content {
namespace internal {
namespace {
base::PlatformFile OpenFileIfNecessary(const base::FilePath& path,
base::MemoryMappedFile::Region* region) {
static auto* opened_files = new std::map<
base::FilePath,
std::pair<base::PlatformFile, base::MemoryMappedFile::Region>>;
const auto& iter = opened_files->find(path);
if (iter != opened_files->end()) {
*region = iter->second.second;
return iter->second.first;
}
base::File file = OpenFileToShare(path, region);
if (!file.IsValid()) {
return base::kInvalidPlatformFile;
}
// g_opened_files becomes the owner of the file descriptor.
base::PlatformFile fd = file.TakePlatformFile();
(*opened_files)[path] = std::make_pair(fd, *region);
return fd;
}
} // namespace
std::unique_ptr<PosixFileDescriptorInfo> CreateDefaultPosixFilesToMap(
int child_process_id,
const mojo::PlatformChannelEndpoint& mojo_channel_remote_endpoint,
const std::map<std::string, absl::variant<base::FilePath, base::ScopedFD>>&
files_to_preload,
const std::string& process_type,
base::CommandLine* command_line) {
std::unique_ptr<PosixFileDescriptorInfo> files_to_register(
PosixFileDescriptorInfoImpl::Create());
// Mac shared memory doesn't use file descriptors.
#if !BUILDFLAG(IS_APPLE)
#if BUILDFLAG(IS_ANDROID)
// Android's endpoint may be a file descriptor or a binder. If it's a binder
// we share it by other means.
const bool share_channel_fd =
!mojo_channel_remote_endpoint.platform_handle().is_binder();
#else
const bool share_channel_fd = true;
#endif
if (share_channel_fd) {
DCHECK(mojo_channel_remote_endpoint.is_valid());
files_to_register->Share(
kMojoIPCChannel,
mojo_channel_remote_endpoint.platform_handle().GetFD().get());
}
// TODO(jcivelli): remove this "if defined" by making
// GetAdditionalMappedFilesForChildProcess a no op on Mac.
GetContentClient()->browser()->GetAdditionalMappedFilesForChildProcess(
*command_line, child_process_id, files_to_register.get());
#endif
// Also include the files specified explicitly by |files_to_preload|.
base::GlobalDescriptors::Key key = kContentDynamicDescriptorStart;
SharedFileSwitchValueBuilder file_switch_value_builder;
for (const auto& key_path_iter : files_to_preload) {
base::MemoryMappedFile::Region region;
base::PlatformFile file = absl::visit(
base::Overloaded{[®ion](const base::FilePath& file_path) {
base::PlatformFile file =
OpenFileIfNecessary(file_path, ®ion);
if (file == base::kInvalidPlatformFile) {
DLOG(WARNING) << "Ignoring invalid file "
<< file_path.value();
}
return file;
},
[®ion](const base::ScopedFD& fd) {
region = base::MemoryMappedFile::Region::kWholeFile;
return fd.get();
}},
key_path_iter.second);
if (file == base::kInvalidPlatformFile) {
continue;
}
file_switch_value_builder.AddEntry(key_path_iter.first, key);
files_to_register->ShareWithRegion(key, file, region);
key++;
DCHECK(key < kContentDynamicDescriptorMax);
}
command_line->AppendSwitchASCII(switches::kSharedFiles,
file_switch_value_builder.switch_value());
return files_to_register;
}
} // namespace internal
} // namespace content