sandboxed-api/sandboxed_api/sandbox2/global_forkclient.h
Christian Blichmann d451478e26 Change license link to HTTPS URL
PiperOrigin-RevId: 424811734
Change-Id: If5ea692edc56ddc9c99fd478673df41c0246e9cc
2022-01-28 01:39:09 -08:00

112 lines
3.6 KiB
C++

// Copyright 2019 Google LLC
//
// 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
//
// https://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.
// StartGlobalForkServer() is called early in a process using a constructor, so
// it can fork() safely (in a single-threaded context)
#ifndef SANDBOXED_API_SANDBOX2_GLOBAL_FORKCLIENT_H_
#define SANDBOXED_API_SANDBOX2_GLOBAL_FORKCLIENT_H_
#include <sys/types.h>
#include <bitset>
#include <string>
#include "absl/base/thread_annotations.h"
#include "sandboxed_api/util/flag.h"
#include "absl/strings/string_view.h"
#include "absl/synchronization/mutex.h"
#include "sandboxed_api/sandbox2/comms.h"
#include "sandboxed_api/sandbox2/fork_client.h"
#include "sandboxed_api/sandbox2/forkserver.pb.h"
namespace sandbox2 {
enum class GlobalForkserverStartMode {
kOnDemand,
// MUST be the last element
kNumGlobalForkserverStartModes,
};
class GlobalForkClient {
public:
GlobalForkClient(int fd, pid_t pid)
: comms_(fd), fork_client_(pid, &comms_) {}
static pid_t SendRequest(const ForkRequest& request, int exec_fd,
int comms_fd, int user_ns_fd = -1,
pid_t* init_pid = nullptr)
ABSL_LOCKS_EXCLUDED(instance_mutex_);
static pid_t GetPid() ABSL_LOCKS_EXCLUDED(instance_mutex_);
static void EnsureStarted() ABSL_LOCKS_EXCLUDED(instance_mutex_) {
EnsureStarted(GlobalForkserverStartMode::kOnDemand);
}
static void Shutdown() ABSL_LOCKS_EXCLUDED(instance_mutex_);
static bool IsStarted() ABSL_LOCKS_EXCLUDED(instance_mutex_);
private:
friend void StartGlobalForkserverFromLibCtor();
static void ForceStart() ABSL_LOCKS_EXCLUDED(instance_mutex_);
static void EnsureStarted(GlobalForkserverStartMode mode)
ABSL_LOCKS_EXCLUDED(instance_mutex_);
static void EnsureStartedLocked(GlobalForkserverStartMode mode)
ABSL_EXCLUSIVE_LOCKS_REQUIRED(instance_mutex_);
static absl::Mutex instance_mutex_;
static GlobalForkClient* instance_ ABSL_GUARDED_BY(instance_mutex_);
Comms comms_;
ForkClient fork_client_;
};
class GlobalForkserverStartModeSet {
public:
static constexpr size_t kSize = static_cast<size_t>(
GlobalForkserverStartMode::kNumGlobalForkserverStartModes);
GlobalForkserverStartModeSet() {}
explicit GlobalForkserverStartModeSet(GlobalForkserverStartMode value) {
value_[static_cast<size_t>(value)] = true;
}
GlobalForkserverStartModeSet& operator|=(GlobalForkserverStartMode value) {
value_[static_cast<size_t>(value)] = true;
return *this;
}
GlobalForkserverStartModeSet operator|(
GlobalForkserverStartMode value) const {
GlobalForkserverStartModeSet rv(*this);
rv |= value;
return rv;
}
bool contains(GlobalForkserverStartMode value) const {
return value_[static_cast<size_t>(value)];
}
bool empty() { return value_.none(); }
private:
std::bitset<kSize> value_;
};
bool AbslParseFlag(absl::string_view text, GlobalForkserverStartModeSet* out,
std::string* error);
std::string AbslUnparseFlag(GlobalForkserverStartModeSet in);
} // namespace sandbox2
ABSL_DECLARE_FLAG(string, sandbox2_forkserver_start_mode);
#endif // SANDBOXED_API_SANDBOX2_GLOBAL_FORKCLIENT_H_