sandboxed-api/sandboxed_api/sandbox2/monitor_unotify.h
Wiktor Garbacz 09a48bac06 Reduce CHECK-failures in unotify monitor
This also fixes a CHECK-failure in Join() when waiting for sandboxee
times out.

PiperOrigin-RevId: 561282248
Change-Id: I5568c3b9e6b8dce531167c267f7896996326d2e2
2023-08-30 02:56:16 -07:00

121 lines
3.5 KiB
C++

#ifndef SANDBOXED_API_SANDBOX2_MONITOR_UNOTIFY_H_
#define SANDBOXED_API_SANDBOX2_MONITOR_UNOTIFY_H_
#include <linux/seccomp.h>
#include <sys/sysinfo.h>
#include <sys/types.h>
#include <atomic>
#include <cstdint>
#include <cstdlib>
#include <memory>
#include <thread>
#include <string>
#include <vector>
#include "absl/log/log.h"
#include "absl/status/statusor.h"
#include "absl/synchronization/mutex.h"
#include "absl/synchronization/notification.h"
#include "absl/time/clock.h"
#include "absl/time/time.h"
#include "sandboxed_api/sandbox2/executor.h"
#include "sandboxed_api/sandbox2/monitor_base.h"
#include "sandboxed_api/sandbox2/notify.h"
#include "sandboxed_api/sandbox2/policy.h"
#include "sandboxed_api/sandbox2/result.h"
#include "sandboxed_api/util/fileops.h"
#include "sandboxed_api/util/raw_logging.h"
namespace sandbox2 {
#ifndef SECCOMP_IOCTL_NOTIF_RECV
struct seccomp_notif {
__u64 id;
__u32 pid;
__u32 flags;
struct seccomp_data data;
};
#endif
class UnotifyMonitor : public MonitorBase {
public:
UnotifyMonitor(Executor* executor, Policy* policy, Notify* notify);
~UnotifyMonitor() { Join(); }
void Kill() override {
external_kill_request_flag_.clear(std::memory_order_relaxed);
NotifyMonitor();
}
void DumpStackTrace() override {
dump_stack_request_flag_.clear(std::memory_order_relaxed);
NotifyMonitor();
}
void SetWallTimeLimit(absl::Duration limit) override {
if (limit == absl::ZeroDuration()) {
VLOG(1) << "Disarming walltime timer to ";
deadline_millis_.store(0, std::memory_order_relaxed);
} else {
VLOG(1) << "Will set the walltime timer to " << limit;
absl::Time deadline = absl::Now() + limit;
deadline_millis_.store(absl::ToUnixMillis(deadline),
std::memory_order_relaxed);
NotifyMonitor();
}
}
private:
// Waits for events from monitored clients and signals from the main process.
void RunInternal() override;
void Join() override;
void Run();
bool InitSetupUnotify();
bool InitSetupNotifyEventFd();
// Kills the main traced PID with SIGKILL.
// Returns false if an error occured and process could not be killed.
bool KillSandboxee();
void KillInit();
void HandleUnotify();
void SetExitStatusFromStatusPipe();
void MaybeGetStackTrace(pid_t pid, Result::StatusEnum status);
absl::StatusOr<std::vector<std::string>> GetStackTrace(pid_t pid);
// Notifies monitor about a state change
void NotifyMonitor();
absl::Notification setup_notification_;
sapi::file_util::fileops::FDCloser seccomp_notify_fd_;
sapi::file_util::fileops::FDCloser monitor_notify_fd_;
// Deadline in Unix millis
std::atomic<int64_t> deadline_millis_{0};
// False iff external kill is requested
std::atomic_flag external_kill_request_flag_ = ATOMIC_FLAG_INIT;
// False iff dump stack is requested
std::atomic_flag dump_stack_request_flag_ = ATOMIC_FLAG_INIT;
// Was external kill sent to the sandboxee
bool external_kill_ = false;
// Network violation occurred and process of killing sandboxee started
bool network_violation_ = false;
// Is the sandboxee timed out
bool timed_out_ = false;
// Monitor thread object.
std::unique_ptr<std::thread> thread_;
// Synchronizes monitor thread deletion and notifying the monitor.
absl::Mutex notify_mutex_;
size_t req_size_;
std::unique_ptr<seccomp_notif, decltype(std::free)*> req_{nullptr, std::free};
};
} // namespace sandbox2
#endif // SANDBOXED_API_SANDBOX2_MONITOR_UNOTIFY_H_