// Copyright (c) 2012 The Chromium 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 CONTENT_ZYGOTE_ZYGOTE_H_
#define CONTENT_ZYGOTE_ZYGOTE_H_
#include <string>
#include <vector>
#include "base/containers/small_map.h"
#include "base/posix/global_descriptors.h"
#include "base/process/kill.h"
#include "base/process/process.h"
class Pickle;
class PickleIterator;
namespace content {
class ZygoteForkDelegate;
// This is the object which implements the zygote. The ZygoteMain function,
// which is called from ChromeMain, simply constructs one of these objects and
// runs it.
class Zygote {
public:
Zygote(int sandbox_flags,
ZygoteForkDelegate* helper);
~Zygote();
bool ProcessRequests();
private:
struct ZygoteProcessInfo {
// Pid from inside the Zygote's PID namespace.
base::ProcessHandle internal_pid;
// Keeps track of whether or not a process was started from a fork
// delegate helper.
bool started_from_helper;
};
typedef base::SmallMap< std::map<base::ProcessHandle, ZygoteProcessInfo> >
ZygoteProcessMap;
// Retrieve a ZygoteProcessInfo from the process_info_map_.
// Returns true and write to process_info if |pid| can be found, return
// false otherwise.
bool GetProcessInfo(base::ProcessHandle pid,
ZygoteProcessInfo* process_info);
// Returns true if the SUID sandbox is active.
bool UsingSUIDSandbox() const;
// ---------------------------------------------------------------------------
// Requests from the browser...
// Read and process a request from the browser. Returns true if we are in a
// new process and thus need to unwind back into ChromeMain.
bool HandleRequestFromBrowser(int fd);
void HandleReapRequest(int fd, const Pickle& pickle, PickleIterator iter);
// Get the termination status of |real_pid|. |real_pid| is the PID as it
// appears outside of the sandbox.
// Return true if it managed to get the termination status and return the
// status in |status| and the exit code in |exit_code|.
bool GetTerminationStatus(base::ProcessHandle real_pid, bool known_dead,
base::TerminationStatus* status,
int* exit_code);
void HandleGetTerminationStatus(int fd,
const Pickle& pickle,
PickleIterator iter);
// This is equivalent to fork(), except that, when using the SUID sandbox, it
// returns the real PID of the child process as it appears outside the
// sandbox, rather than returning the PID inside the sandbox. Optionally, it
// fills in uma_name et al with a report the helper wants to make via
// UMA_HISTOGRAM_ENUMERATION.
int ForkWithRealPid(const std::string& process_type,
const base::GlobalDescriptors::Mapping& fd_mapping,
const std::string& channel_switch,
std::string* uma_name,
int* uma_sample,
int* uma_boundary_value);
// Unpacks process type and arguments from |pickle| and forks a new process.
// Returns -1 on error, otherwise returns twice, returning 0 to the child
// process and the child process ID to the parent process, like fork().
base::ProcessId ReadArgsAndFork(const Pickle& pickle,
PickleIterator iter,
std::vector<int>& fds,
std::string* uma_name,
int* uma_sample,
int* uma_boundary_value);
// Handle a 'fork' request from the browser: this means that the browser
// wishes to start a new renderer. Returns true if we are in a new process,
// otherwise writes the child_pid back to the browser via |fd|. Writes a
// child_pid of -1 on error.
bool HandleForkRequest(int fd,
const Pickle& pickle,
PickleIterator iter,
std::vector<int>& fds);
bool HandleGetSandboxStatus(int fd,
const Pickle& pickle,
PickleIterator iter);
// The Zygote needs to keep some information about each process. Most
// notably what the PID of the process is inside the PID namespace of
// the Zygote and whether or not a process was started by the
// ZygoteForkDelegate helper.
ZygoteProcessMap process_info_map_;
const int sandbox_flags_;
ZygoteForkDelegate* helper_;
// These might be set by helper_->InitialUMA. They supply a UMA enumeration
// sample we should report on the first fork.
std::string initial_uma_name_;
int initial_uma_sample_;
int initial_uma_boundary_value_;
};
} // namespace content
#endif // CONTENT_ZYGOTE_ZYGOTE_H_