126 lines
5.3 KiB
C++
126 lines
5.3 KiB
C++
// Copyright 2015 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 SANDBOX_LINUX_SERVICES_NAMESPACE_SANDBOX_H_
|
|
#define SANDBOX_LINUX_SERVICES_NAMESPACE_SANDBOX_H_
|
|
|
|
#include <sys/types.h>
|
|
|
|
#include <string>
|
|
#include <vector>
|
|
|
|
#include "base/command_line.h"
|
|
#include "base/macros.h"
|
|
#include "base/process/launch.h"
|
|
#include "base/process/process.h"
|
|
#include "sandbox/sandbox_export.h"
|
|
|
|
namespace sandbox {
|
|
|
|
// Helper class for starting a process inside a new user, PID, and network
|
|
// namespace. Before using a namespace sandbox, check for namespaces support
|
|
// using Credentials::CanCreateProcessInNewUserNS.
|
|
//
|
|
// A typical use for "A" launching a sandboxed process "B" would be:
|
|
// 1. A sets up a command line and launch options for process B.
|
|
// 2. A launches B with LaunchProcess.
|
|
// 3. B should be prepared to assume the role of init(1). In particular, apart
|
|
// from SIGKILL and SIGSTOP, B cannot receive any signal for which it does
|
|
// not have an explicit signal handler registered.
|
|
// If B dies, all the processes in the namespace will die.
|
|
// B can fork() and the parent can assume the role of init(1), by using
|
|
// CreateInitProcessReaper().
|
|
// 4. B chroots using Credentials::MoveToNewUserNS() and
|
|
// Credentials::DropFileSystemAccess()
|
|
// 5. B drops capabilities gained by entering the new user namespace with
|
|
// Credentials::DropAllCapabilities().
|
|
class SANDBOX_EXPORT NamespaceSandbox {
|
|
public:
|
|
#if !defined(OS_NACL_NONSFI)
|
|
struct Options {
|
|
Options();
|
|
~Options();
|
|
|
|
// Bitmask of namespace types. Must be some combination of CLONE_NEWUSER
|
|
// (required), CLONE_NEWPID, and CLONE_NEWNET. Defaults to all of the above.
|
|
int ns_types;
|
|
|
|
// Fail if any of the namespace types are not supported. Defaults to false.
|
|
bool fail_on_unsupported_ns_type;
|
|
};
|
|
|
|
// Launch a new process inside its own user/PID/network namespaces (depending
|
|
// on kernel support). Requires at a minimum that user namespaces are
|
|
// supported (use Credentials::CanCreateProcessInNewUserNS to check this).
|
|
//
|
|
// pre_exec_delegate and clone_flags fields of LaunchOptions should be nullptr
|
|
// and 0, respectively, since this function makes a copy of options and
|
|
// overrides them.
|
|
static base::Process LaunchProcess(const base::CommandLine& cmdline,
|
|
const base::LaunchOptions& launch_options);
|
|
static base::Process LaunchProcess(const std::vector<std::string>& argv,
|
|
const base::LaunchOptions& launch_options);
|
|
|
|
// Versions which take namespace sandbox options. These allow fine grained
|
|
// control over the types of namespaces used.
|
|
static base::Process LaunchProcessWithOptions(
|
|
const base::CommandLine& cmdline,
|
|
const base::LaunchOptions& launch_options,
|
|
const Options& ns_sandbox_options);
|
|
static base::Process LaunchProcessWithOptions(
|
|
const std::vector<std::string>& argv,
|
|
const base::LaunchOptions& launch_options,
|
|
const Options& ns_sandbox_options);
|
|
#endif // !defined(OS_NACL_NONSFI)
|
|
|
|
// Forks a process in its own PID namespace. The child process is the init
|
|
// process inside of the PID namespace, so if the child needs to fork further,
|
|
// it should call CreateInitProcessReaper, which turns the init process into a
|
|
// reaper process.
|
|
//
|
|
// Otherwise, the child should setup handlers for signals which should
|
|
// terminate the process using InstallDefaultTerminationSignalHandlers or
|
|
// InstallTerminationSignalHandler. This works around the fact that init
|
|
// processes ignore such signals unless they have an explicit handler set.
|
|
//
|
|
// This function requries CAP_SYS_ADMIN. If |drop_capabilities_in_child| is
|
|
// true, then capabilities are dropped in the child.
|
|
static pid_t ForkInNewPidNamespace(bool drop_capabilities_in_child);
|
|
|
|
// Installs a signal handler for:
|
|
//
|
|
// SIGHUP, SIGINT, SIGABRT, SIGQUIT, SIGPIPE, SIGTERM, SIGUSR1, SIGUSR2
|
|
//
|
|
// that exits with SignalExitCode(sig). These are signals whose default action
|
|
// is to terminate the program (apart from SIGILL, SIGFPE, and SIGSEGV, which
|
|
// will still terminate the process if e.g. an illegal instruction is
|
|
// encountered, etc.).
|
|
//
|
|
// If any of these already had a signal handler installed, this function will
|
|
// not override them.
|
|
static void InstallDefaultTerminationSignalHandlers();
|
|
|
|
// Installs a signal handler for |sig| which exits with |exit_code|. If a
|
|
// signal handler was already present for |sig|, does nothing and returns
|
|
// false.
|
|
static bool InstallTerminationSignalHandler(int sig, int exit_code);
|
|
|
|
// Returns an exit code corresponding to the process being killed by sig. This
|
|
// is the same as exit code that NaCl's default signal handler uses.
|
|
static int SignalExitCode(int sig) { return -sig & 0xff; }
|
|
|
|
// Returns whether the namespace sandbox created a new user, PID, and network
|
|
// namespace. In particular, InNewUserNamespace should return true iff the
|
|
// process was started via this class.
|
|
static bool InNewUserNamespace();
|
|
static bool InNewPidNamespace();
|
|
static bool InNewNetNamespace();
|
|
|
|
private:
|
|
DISALLOW_IMPLICIT_CONSTRUCTORS(NamespaceSandbox);
|
|
};
|
|
|
|
} // namespace sandbox
|
|
|
|
#endif // SANDBOX_LINUX_SERVICES_NAMESPACE_SANDBOX_H_
|