ladybird/Userland/Services/SystemServer/main.cpp
Linus Groh 6e19ab2bbc AK+Everywhere: Rename String to DeprecatedString
We have a new, improved string type coming up in AK (OOM aware, no null
state), and while it's going to use UTF-8, the name UTF8String is a
mouthful - so let's free up the String name by renaming the existing
class.
Making the old one have an annoying name will hopefully also help with
quick adoption :^)
2022-12-06 08:54:33 +01:00

537 lines
18 KiB
C++

/*
* Copyright (c) 2018-2021, Andreas Kling <kling@serenityos.org>
* Copyright (c) 2021, Peter Elliott <pelliott@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include "Service.h"
#include <AK/Assertions.h>
#include <AK/ByteBuffer.h>
#include <AK/Debug.h>
#include <Kernel/API/DeviceEvent.h>
#include <LibCore/ArgsParser.h>
#include <LibCore/ConfigFile.h>
#include <LibCore/DirIterator.h>
#include <LibCore/Event.h>
#include <LibCore/EventLoop.h>
#include <LibCore/File.h>
#include <LibCore/System.h>
#include <LibMain/Main.h>
#include <errno.h>
#include <fcntl.h>
#include <grp.h>
#include <signal.h>
#include <stdio.h>
#include <sys/stat.h>
#include <sys/sysmacros.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
DeprecatedString g_system_mode = "graphical";
NonnullRefPtrVector<Service> g_services;
// NOTE: This handler ensures that the destructor of g_services is called.
static void sigterm_handler(int)
{
exit(0);
}
static void sigchld_handler(int)
{
for (;;) {
int status = 0;
pid_t pid = waitpid(-1, &status, WNOHANG);
if (pid < 0) {
perror("waitpid");
break;
}
if (pid == 0)
break;
dbgln_if(SYSTEMSERVER_DEBUG, "Reaped child with pid {}, exit status {}", pid, status);
Service* service = Service::find_by_pid(pid);
if (service == nullptr) {
// This can happen for multi-instance services.
continue;
}
service->did_exit(status);
}
}
static ErrorOr<void> determine_system_mode()
{
ArmedScopeGuard declare_text_mode_on_failure([&] {
// Note: Only if the mode is not set to self-test, degrade it to text mode.
if (g_system_mode != "self-test")
g_system_mode = "text";
});
auto f = Core::File::construct("/sys/kernel/system_mode");
if (!f->open(Core::OpenMode::ReadOnly)) {
dbgln("Failed to read system_mode: {}", f->error_string());
// Continue and assume "text" mode.
return {};
}
const DeprecatedString system_mode = DeprecatedString::copy(f->read_all(), Chomp);
if (f->error()) {
dbgln("Failed to read system_mode: {}", f->error_string());
// Continue and assume "text" mode.
return {};
}
g_system_mode = system_mode;
declare_text_mode_on_failure.disarm();
dbgln("Read system_mode: {}", g_system_mode);
struct stat file_state;
int rc = lstat("/dev/gpu/connector0", &file_state);
if (rc != 0 && g_system_mode == "graphical") {
dbgln("WARNING: No device nodes at /dev/gpu/ directory. This is probably a sign of disabled graphics functionality.");
dbgln("To cope with this, I'll turn off graphical mode.");
g_system_mode = "text";
}
return {};
}
static ErrorOr<void> chown_all_matching_device_nodes_under_specific_directory(StringView directory, group const& group)
{
struct stat cur_file_stat;
Core::DirIterator di(directory, Core::DirIterator::SkipParentAndBaseDir);
if (di.has_error())
VERIFY_NOT_REACHED();
while (di.has_next()) {
auto entry_name = di.next_full_path();
auto rc = stat(entry_name.characters(), &cur_file_stat);
if (rc < 0)
continue;
TRY(Core::System::chown(entry_name, 0, group.gr_gid));
}
return {};
}
static ErrorOr<void> chown_all_matching_device_nodes(group const& group, unsigned major_number)
{
struct stat cur_file_stat;
Core::DirIterator di("/dev/", Core::DirIterator::SkipParentAndBaseDir);
if (di.has_error())
VERIFY_NOT_REACHED();
while (di.has_next()) {
auto entry_name = di.next_full_path();
auto rc = stat(entry_name.characters(), &cur_file_stat);
if (rc < 0)
continue;
if (major(cur_file_stat.st_rdev) != major_number)
continue;
TRY(Core::System::chown(entry_name, 0, group.gr_gid));
}
return {};
}
inline char offset_character_with_number(char base_char, u8 offset)
{
char offsetted_char = base_char;
VERIFY(static_cast<size_t>(offsetted_char) + static_cast<size_t>(offset) < 256);
offsetted_char += offset;
return offsetted_char;
}
static void create_devtmpfs_block_device(DeprecatedString name, mode_t mode, unsigned major, unsigned minor)
{
if (auto rc = mknod(name.characters(), mode | S_IFBLK, makedev(major, minor)); rc < 0)
VERIFY_NOT_REACHED();
}
static void create_devtmpfs_char_device(DeprecatedString name, mode_t mode, unsigned major, unsigned minor)
{
if (auto rc = mknod(name.characters(), mode | S_IFCHR, makedev(major, minor)); rc < 0)
VERIFY_NOT_REACHED();
}
static void populate_devtmpfs_char_devices_based_on_sysfs()
{
Core::DirIterator di("/sys/dev/char/", Core::DirIterator::SkipParentAndBaseDir);
if (di.has_error()) {
warnln("Failed to open /sys/dev/char - {}", di.error());
VERIFY_NOT_REACHED();
}
while (di.has_next()) {
auto entry_name = di.next_path().split(':');
VERIFY(entry_name.size() == 2);
auto major_number = entry_name[0].to_uint<unsigned>().value();
auto minor_number = entry_name[1].to_uint<unsigned>().value();
switch (major_number) {
case 2: {
switch (minor_number) {
case 10: {
create_devtmpfs_char_device("/dev/devctl", 0660, 2, 10);
break;
}
default:
warnln("Unknown character device {}:{}", major_number, minor_number);
}
break;
}
default:
break;
}
}
}
static void populate_devtmpfs_devices_based_on_devctl()
{
auto f = Core::File::construct("/dev/devctl");
if (!f->open(Core::OpenMode::ReadOnly)) {
warnln("Failed to open /dev/devctl - {}", f->error_string());
VERIFY_NOT_REACHED();
}
DeviceEvent event;
while (f->read((u8*)&event, sizeof(DeviceEvent)) > 0) {
if (event.state != DeviceEvent::Inserted)
continue;
auto major_number = event.major_number;
auto minor_number = event.minor_number;
bool is_block_device = (event.is_block_device == 1);
switch (major_number) {
case 116: {
if (!is_block_device) {
create_devtmpfs_char_device(DeprecatedString::formatted("/dev/audio/{}", minor_number), 0220, 116, minor_number);
break;
}
break;
}
case 28: {
create_devtmpfs_block_device(DeprecatedString::formatted("/dev/gpu/render{}", minor_number), 0666, 28, minor_number);
break;
}
case 226: {
create_devtmpfs_char_device(DeprecatedString::formatted("/dev/gpu/connector{}", minor_number), 0666, 226, minor_number);
break;
}
case 229: {
if (!is_block_device) {
create_devtmpfs_char_device(DeprecatedString::formatted("/dev/hvc0p{}", minor_number), 0666, major_number, minor_number);
}
break;
}
case 10: {
if (!is_block_device) {
switch (minor_number) {
case 0: {
create_devtmpfs_char_device("/dev/input/mouse/0", 0660, 10, 0);
break;
}
case 183: {
create_devtmpfs_char_device("/dev/hwrng", 0660, 10, 183);
break;
}
default:
warnln("Unknown character device {}:{}", major_number, minor_number);
}
}
break;
}
case 85: {
if (!is_block_device) {
switch (minor_number) {
case 0: {
create_devtmpfs_char_device("/dev/input/keyboard/0", 0660, 85, 0);
break;
}
default:
warnln("Unknown character device {}:{}", major_number, minor_number);
}
}
break;
}
case 1: {
if (!is_block_device) {
switch (minor_number) {
case 5: {
create_devtmpfs_char_device("/dev/zero", 0666, 1, 5);
break;
}
case 1: {
create_devtmpfs_char_device("/dev/mem", 0660, 1, 1);
break;
}
case 3: {
create_devtmpfs_char_device("/dev/null", 0666, 1, 3);
break;
}
case 7: {
create_devtmpfs_char_device("/dev/full", 0666, 1, 7);
break;
}
case 8: {
create_devtmpfs_char_device("/dev/random", 0666, 1, 8);
break;
}
default:
warnln("Unknown character device {}:{}", major_number, minor_number);
break;
}
}
break;
}
case 30: {
if (!is_block_device) {
create_devtmpfs_char_device(DeprecatedString::formatted("/dev/kcov{}", minor_number), 0666, 30, minor_number);
}
break;
}
case 3: {
if (is_block_device) {
create_devtmpfs_block_device(DeprecatedString::formatted("/dev/hd{}", offset_character_with_number('a', minor_number)), 0600, 3, minor_number);
}
break;
}
case 5: {
if (!is_block_device) {
switch (minor_number) {
case 1: {
create_devtmpfs_char_device("/dev/console", 0666, 5, 1);
break;
}
case 2: {
create_devtmpfs_char_device("/dev/ptmx", 0666, 5, 2);
break;
}
case 0: {
create_devtmpfs_char_device("/dev/tty", 0666, 5, 0);
break;
}
default:
warnln("Unknown character device {}:{}", major_number, minor_number);
}
}
break;
}
case 4: {
if (!is_block_device) {
switch (minor_number) {
case 0: {
create_devtmpfs_char_device("/dev/tty0", 0620, 4, 0);
break;
}
case 1: {
create_devtmpfs_char_device("/dev/tty1", 0620, 4, 1);
break;
}
case 2: {
create_devtmpfs_char_device("/dev/tty2", 0620, 4, 2);
break;
}
case 3: {
create_devtmpfs_char_device("/dev/tty3", 0620, 4, 3);
break;
}
case 64: {
create_devtmpfs_char_device("/dev/ttyS0", 0620, 4, 64);
break;
}
case 65: {
create_devtmpfs_char_device("/dev/ttyS1", 0620, 4, 65);
break;
}
case 66: {
create_devtmpfs_char_device("/dev/ttyS2", 0620, 4, 66);
break;
}
case 67: {
create_devtmpfs_char_device("/dev/ttyS3", 0666, 4, 67);
break;
}
default:
warnln("Unknown character device {}:{}", major_number, minor_number);
}
}
break;
}
default:
if (!is_block_device)
warnln("Unknown character device {}:{}", major_number, minor_number);
else
warnln("Unknown block device {}:{}", major_number, minor_number);
break;
}
}
}
static void populate_devtmpfs()
{
mode_t old_mask = umask(0);
printf("Changing umask %#o\n", old_mask);
populate_devtmpfs_char_devices_based_on_sysfs();
populate_devtmpfs_devices_based_on_devctl();
umask(old_mask);
}
static ErrorOr<void> prepare_synthetic_filesystems()
{
// FIXME: Find a better way to all of this stuff, without hardcoding all of this!
TRY(Core::System::mount(-1, "/proc"sv, "proc"sv, MS_NOSUID));
TRY(Core::System::mount(-1, "/sys"sv, "sys"sv, 0));
TRY(Core::System::mount(-1, "/dev"sv, "tmp"sv, MS_NOSUID | MS_NOEXEC | MS_NOREGULAR));
TRY(Core::System::mkdir("/dev/audio"sv, 0755));
TRY(Core::System::mkdir("/dev/input"sv, 0755));
TRY(Core::System::mkdir("/dev/input/keyboard"sv, 0755));
TRY(Core::System::mkdir("/dev/input/mouse"sv, 0755));
TRY(Core::System::symlink("/proc/self/fd/0"sv, "/dev/stdin"sv));
TRY(Core::System::symlink("/proc/self/fd/1"sv, "/dev/stdout"sv));
TRY(Core::System::symlink("/proc/self/fd/2"sv, "/dev/stderr"sv));
TRY(Core::System::mkdir("/dev/gpu"sv, 0755));
populate_devtmpfs();
TRY(Core::System::mkdir("/dev/pts"sv, 0755));
TRY(Core::System::mount(-1, "/dev/pts"sv, "devpts"sv, 0));
TRY(Core::System::symlink("/dev/random"sv, "/dev/urandom"sv));
TRY(Core::System::chmod("/dev/urandom"sv, 0666));
auto phys_group = TRY(Core::System::getgrnam("phys"sv));
VERIFY(phys_group.has_value());
// FIXME: Try to find a way to not hardcode the major number of display connector device nodes.
TRY(chown_all_matching_device_nodes(phys_group.value(), 29));
auto const filter_chown_ENOENT = [](ErrorOr<void> result) -> ErrorOr<void> {
auto const chown_enoent = Error::from_syscall("chown"sv, -ENOENT);
if (result.is_error() && result.error() == chown_enoent) {
dbgln("{}", result.release_error());
return {};
}
return result;
};
TRY(filter_chown_ENOENT(Core::System::chown("/dev/input/keyboard/0"sv, 0, phys_group.value().gr_gid)));
TRY(filter_chown_ENOENT(Core::System::chown("/dev/input/mouse/0"sv, 0, phys_group.value().gr_gid)));
auto tty_group = TRY(Core::System::getgrnam("tty"sv));
VERIFY(tty_group.has_value());
// FIXME: Try to find a way to not hardcode the major number of tty nodes.
TRY(chown_all_matching_device_nodes(tty_group.release_value(), 4));
auto audio_group = TRY(Core::System::getgrnam("audio"sv));
VERIFY(audio_group.has_value());
TRY(Core::System::chown("/dev/audio"sv, 0, audio_group->gr_gid));
TRY(chown_all_matching_device_nodes_under_specific_directory("/dev/audio"sv, audio_group.release_value()));
// Note: We open the /dev/null device and set file descriptors 0, 1, 2 to it
// because otherwise these file descriptors won't have a custody, making
// the ProcFS file descriptor links (at /proc/PID/fd/{0,1,2}) to have an
// absolute path of "device:1,3" instead of something like "/dev/null".
// This affects also every other process that inherits the file descriptors
// from SystemServer, so it is important for other things (also for ProcFS
// tests that are running in CI mode).
int stdin_new_fd = TRY(Core::System::open("/dev/null"sv, O_NONBLOCK));
TRY(Core::System::dup2(stdin_new_fd, 0));
TRY(Core::System::dup2(stdin_new_fd, 1));
TRY(Core::System::dup2(stdin_new_fd, 2));
TRY(Core::System::endgrent());
return {};
}
static ErrorOr<void> mount_all_filesystems()
{
dbgln("Spawning mount -a to mount all filesystems.");
pid_t pid = TRY(Core::System::fork());
if (pid == 0)
TRY(Core::System::exec("/bin/mount"sv, Vector { "mount"sv, "-a"sv }, Core::System::SearchInPath::No));
wait(nullptr);
return {};
}
static ErrorOr<void> create_tmp_coredump_directory()
{
dbgln("Creating /tmp/coredump directory");
auto old_umask = umask(0);
// FIXME: the coredump directory should be made read-only once CrashDaemon is no longer responsible for compressing coredumps
TRY(Core::System::mkdir("/tmp/coredump"sv, 0777));
umask(old_umask);
return {};
}
static ErrorOr<void> set_default_coredump_directory()
{
dbgln("Setting /tmp/coredump as the coredump directory");
auto sysfs_coredump_directory_variable_fd = TRY(Core::System::open("/sys/kernel/variables/coredump_directory"sv, O_RDWR));
ScopeGuard close_on_exit([&] {
close(sysfs_coredump_directory_variable_fd);
});
auto tmp_coredump_directory_path = "/tmp/coredump"sv;
auto nwritten = TRY(Core::System::write(sysfs_coredump_directory_variable_fd, tmp_coredump_directory_path.bytes()));
VERIFY(static_cast<size_t>(nwritten) == tmp_coredump_directory_path.length());
return {};
}
static ErrorOr<void> create_tmp_semaphore_directory()
{
dbgln("Creating /tmp/semaphore directory");
auto old_umask = umask(0);
TRY(Core::System::mkdir("/tmp/semaphore"sv, 0777));
umask(old_umask);
return {};
}
ErrorOr<int> serenity_main(Main::Arguments arguments)
{
bool user = false;
Core::ArgsParser args_parser;
args_parser.add_option(user, "Run in user-mode", "user", 'u');
args_parser.parse(arguments);
if (!user) {
TRY(mount_all_filesystems());
TRY(prepare_synthetic_filesystems());
}
TRY(Core::System::pledge("stdio proc exec tty accept unix rpath wpath cpath chown fattr id sigaction"));
if (!user) {
TRY(create_tmp_coredump_directory());
TRY(set_default_coredump_directory());
TRY(create_tmp_semaphore_directory());
TRY(determine_system_mode());
}
Core::EventLoop event_loop;
event_loop.register_signal(SIGCHLD, sigchld_handler);
event_loop.register_signal(SIGTERM, sigterm_handler);
// Read our config and instantiate services.
// This takes care of setting up sockets.
auto config = (user)
? TRY(Core::ConfigFile::open_for_app("SystemServer"))
: TRY(Core::ConfigFile::open_for_system("SystemServer"));
for (auto const& name : config->groups()) {
auto service = TRY(Service::try_create(*config, name));
if (service->is_enabled())
g_services.append(move(service));
}
// After we've set them all up, activate them!
dbgln("Activating {} services...", g_services.size());
for (auto& service : g_services)
service.activate();
return event_loop.exec();
}