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// Copyright 2018 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef SHILL_PROCESS_MANAGER_H_
#define SHILL_PROCESS_MANAGER_H_
#include <map>
#include <memory>
#include <string>
#include <vector>
#include <base/callback.h>
#include <base/cancelable_callback.h>
#include <base/files/file_path.h>
#include <base/lazy_instance.h>
#include <base/location.h>
#include <base/memory/weak_ptr.h>
#include <brillo/minijail/minijail.h>
#include <brillo/process/process.h>
#include <brillo/process/process_reaper.h>
#include <libminijail.h>
namespace shill {
struct std_file_descriptors {
int* stdin_fd;
int* stdout_fd;
int* stderr_fd;
};
class EventDispatcher;
// The ProcessManager is a singleton providing process creation and
// asynchronous process termination. Need to initialize it once with
// Init method call.
class ProcessManager {
public:
virtual ~ProcessManager();
// This is a singleton -- use ProcessManager::GetInstance()->Foo().
static ProcessManager* GetInstance();
// Register async signal handler and setup process reaper.
virtual void Init(EventDispatcher* dispatcher);
// Call on shutdown to release async_signal_handler_.
virtual void Stop();
// Create and start a process for |program| with |arguments|. |environment|
// variables will be setup in the child process before exec the |program|.
// |terminate_with_parent| is used to indicate if child process should
// self terminate if the parent process exits. |exit_callback| will be
// invoked when child process exits (not terminated by us). Return -1
// if failed to start the process, otherwise, return the pid of the child
// process.
virtual pid_t StartProcess(
const base::Location& spawn_source,
const base::FilePath& program,
const std::vector<std::string>& arguments,
const std::map<std::string, std::string>& environment,
bool terminate_with_parent,
const base::Callback<void(int)>& exit_callback);
// Similar to StartProcess(), with the following differences:
// - terminate_with_parent is not supported (may be non-trivial)
// - the child process will run as |user| and |group|
// - the |capmask| argument can be used to provide the child process
// with capabilities, which |user| might not have on its own
// - the |inherit_supplementary_groups| argument allows child process to
// inherit supplementary groups from uid, equivalent to using '-G' on the
// minijail command line.
virtual pid_t StartProcessInMinijail(
const base::Location& spawn_source,
const base::FilePath& program,
const std::vector<std::string>& arguments,
const std::map<std::string, std::string>& environment,
const std::string& user,
const std::string& group,
uint64_t capmask,
bool inherit_supplementary_groups,
bool close_nonstd_fds,
const base::Callback<void(int)>& exit_callback) {
return StartProcessInMinijailWithPipes(
spawn_source, program, arguments, environment, user, group, capmask,
inherit_supplementary_groups, close_nonstd_fds, exit_callback,
(struct std_file_descriptors){nullptr, nullptr, nullptr});
}
// Similar to StartProcessInMinijail(), with the additional ability to
// pipe the child's stdin/stdout/stderr back to us. If any of those
// streams is not needed, simply pass nullptr for the corresponding
// member in std file descriptor struct. If no pipes are needed, use
// StartProcessInMinijail().
virtual pid_t StartProcessInMinijailWithPipes(
const base::Location& spawn_source,
const base::FilePath& program,
const std::vector<std::string>& arguments,
const std::map<std::string, std::string>& environment,
const std::string& user,
const std::string& group,
uint64_t capmask,
bool inherit_supplementary_groups,
bool close_nonstd_fds,
const base::Callback<void(int)>& exit_callback,
struct std_file_descriptors std_fds);
// Stop the given |pid|. Previously registered |exit_callback| will be
// unregistered, since the caller is not interested in this process anymore
// and that callback might not be valid by the time this process terminates.
// This will attempt to terminate the child process by sending a SIGTERM
// signal first. If the process doesn't terminate within a certain time,
// ProcessManager will attempt to send a SIGKILL signal. It will give up
// with an error log If the process still doesn't terminate within a certain
// time.
virtual bool StopProcess(pid_t pid);
// Stop the given |pid| in a synchronous manner.
virtual bool StopProcessAndBlock(pid_t pid);
// Replace the current exit callback for |pid| with |new_callback|.
virtual bool UpdateExitCallback(
pid_t pid, const base::Callback<void(int)>& new_callback);
protected:
ProcessManager();
private:
friend class ProcessManagerTest;
friend base::LazyInstanceTraitsBase<ProcessManager>;
using TerminationTimeoutCallback = base::CancelableClosure;
// Invoked when process |pid| exited.
void OnProcessExited(pid_t pid, const siginfo_t& info);
// Invoked when process |pid| did not terminate within a certain timeout.
// |kill_signal| indicates the signal used for termination. When it is set
// to true, SIGKILL was used to terminate the process, otherwise, SIGTERM
// was used.
void ProcessTerminationTimeoutHandler(pid_t pid, bool kill_signal);
// Send a termination signal to process |pid|. If |kill_signal| is set to
// true, SIGKILL is sent, otherwise, SIGTERM is sent. After signal is sent,
// |pid| and timeout handler is added to |pending_termination_processes_|
// list, to make sure process |pid| does exit in timely manner.
bool TerminateProcess(pid_t pid, bool kill_signal);
// Kill process |pid|. If |kill_signal| is true it will send SIGKILL,
// otherwise it will send SIGTERM.
// It returns true when the process was already dead or killed within
// the timeout.
// It returns false when the process failed to exit within the timeout
// or the system failed to send kill singal.
bool KillProcessWithTimeout(pid_t pid, bool kill_signal);
// Kill process |pid| using signal |signal|.
// The |killed| will be set true when the process was already dead.
// It returns true when it sent the |signal| successfully or the
// process was already dead.
// It returns false when the system failed to send |signal|.
bool KillProcess(pid_t pid, int signal, bool* killed);
// Wait for process |pid| to exit. This function will check it for at most
// |tries| times. The interval of waiting time grows exponentially from
// |sleep_ms| and it has an |upper_bound_ms| upper bound.
bool WaitpidWithTimeout(pid_t pid,
unsigned int sleep_ms,
unsigned int upper_bound_ms,
int tries);
// Used to watch processes.
std::unique_ptr<brillo::AsynchronousSignalHandler> async_signal_handler_;
brillo::ProcessReaper process_reaper_;
EventDispatcher* dispatcher_;
brillo::Minijail* minijail_;
// Processes to watch for the caller.
std::map<pid_t, base::Callback<void(int)>> watched_processes_;
// Processes being terminated by us. Use a timer to make sure process
// does exit, log an error if it failed to exit within a specific timeout.
std::map<pid_t, std::unique_ptr<TerminationTimeoutCallback>>
pending_termination_processes_;
base::WeakPtrFactory<ProcessManager> weak_factory_{this};
DISALLOW_COPY_AND_ASSIGN(ProcessManager);
};
} // namespace shill
#endif // SHILL_PROCESS_MANAGER_H_