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// Copyright 2015 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef CONTENT_COMMON_ZYGOTE_ZYGOTE_COMMUNICATION_LINUX_H_
#define CONTENT_COMMON_ZYGOTE_ZYGOTE_COMMUNICATION_LINUX_H_
#include <memory>
#include <set>
#include <string>
#include <vector>
#include <sys/types.h>
#include "base/files/platform_file.h"
#include "base/files/scoped_file.h"
#include "base/functional/callback.h"
#include "base/process/kill.h"
#include "base/process/launch.h"
#include "base/process/process_handle.h"
#include "base/synchronization/lock.h"
#include "content/common/content_export.h"
namespace base {
class Pickle;
} // namespace base
namespace content {
// Handles interprocess communication with the Linux zygote process. The zygote
// does not use standard Chrome IPC or mojo, see:
// https://chromium.googlesource.com/chromium/src/+/main/docs/linux/sandbox_ipc.md
class CONTENT_EXPORT ZygoteCommunication {
public:
enum class ZygoteType { kSandboxed, kUnsandboxed };
explicit ZygoteCommunication(ZygoteType type);
~ZygoteCommunication();
void Init(
base::OnceCallback<pid_t(base::CommandLine*, base::ScopedFD*)> launcher);
// Reinitialize logging. Needed on ChromeOS, which switches to a log file
// in the user's home directory once they log in.
void ReinitializeLogging(uint32_t logging_dest,
base::PlatformFile log_file_fd);
// Tries to start a process of type indicated by process_type.
// Returns its pid on success, otherwise base::kNullProcessHandle;
pid_t ForkRequest(const std::vector<std::string>& command_line,
const base::FileHandleMappingVector& mapping,
const std::string& process_type);
void EnsureProcessTerminated(pid_t process);
// Should be called every time a Zygote child died.
void ZygoteChildDied(pid_t process);
// Get the termination status (and, optionally, the exit code) of
// the process. |exit_code| is set to the exit code of the child
// process. (|exit_code| may be NULL.)
// Unfortunately the Zygote can not accurately figure out if a process
// is already dead without waiting synchronously for it.
// |known_dead| should be set to true when we already know that the process
// is dead. When |known_dead| is false, processes could be seen as
// still running, even when they're not. When |known_dead| is true, the
// process will be SIGKILL-ed first (which should have no effect if it was
// really dead). This is to prevent a waiting waitpid() from blocking in
// a single-threaded Zygote. See https://crbug.com/157458.
base::TerminationStatus GetTerminationStatus(base::ProcessHandle handle,
bool known_dead,
int* exit_code);
// Returns the sandbox status of this zygote.
int GetSandboxStatus();
private:
// Should be called every time a Zygote child is born.
void ZygoteChildBorn(pid_t process);
// Read the reply from the zygote.
ssize_t ReadReply(void* buf, size_t buf_len);
// Sends |data| to the zygote via |control_fd_|. If |fds| is non-NULL, the
// included file descriptors will also be passed. The caller is responsible
// for acquiring |control_lock_|.
bool SendMessage(const base::Pickle& data, const std::vector<int>* fds);
// Get the sandbox status from the zygote.
ssize_t ReadSandboxStatus();
// Indicates whether the Zygote starts unsandboxed or not.
const ZygoteType type_;
base::ScopedFD control_fd_; // the socket to the zygote.
// A lock protecting all communication with the zygote. This lock must be
// acquired before sending a command and released after the result has been
// received.
base::Lock control_lock_;
// The pid of the zygote.
pid_t pid_;
// The list of running zygote children.
std::set<pid_t> list_of_running_zygote_children_;
// The lock to guard the list of running zygote children.
base::Lock child_tracking_lock_;
int sandbox_status_;
bool have_read_sandbox_status_word_;
// Set to true when the zygote is initialized successfully.
bool init_;
};
} // namespace content
#endif // CONTENT_COMMON_ZYGOTE_ZYGOTE_COMMUNICATION_LINUX_H_
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