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platform_system_core/init/builtins.cpp
Jiyong Park 2599088ff6 Bionic libs and the dynamic linker are bind mounted 
This change makes the bionic libs and the dynamic linker from the
runtime APEX (com.android.runtime) available to all processes started
after apexd finishes activating APEXes.

Specifically, the device has two sets of bionic libs and the dynamic
linker: one in the system partition for pre-apexd processes and another
in the runtime APEX for post-apexd processes. The former is referred as
the 'bootstrap' bionic and are located at
/system/lib/{libc|libdl|libm}.so and /system/bin/linker. The latter is
referred as the 'runtime' bionic and are located at
/apex/com.android.runtime/lib/bionic/{libc|libdl|libm}.so and
/apex/com.android.runtime/bin/linker.

Although the two sets are located in different directories, at runtime,
they are accessed via the same path: /system/lib/* and
/system/bin/linker ... for both pre/post-apexd processes. This is done
by bind-mounting the bootstrap or the runtime bionic to the same path.
Keeping the same path is necessary because there are many modules and
apps that explicitly or implicitly depend on the fact that bionic libs
are located in /system/lib and are loaded into the default linker
namespace (which has /system/lib in its search paths).

Before the apexd is started, init executes a built-in action
'prepare_bootstrap_bionic' that bind-mounts the bootstrap bionic to the
mount points. Processes started during this time are provided with the
bootstrap bionic. Then after the apexd is finished, init executes
another built-in action 'setup_runtime_bionic' which again mounts the
runtime bionic to the same mount points, thus hiding the previous mounts
that target the bootstrap bionic. The mounting of the runtime bionic
(which is only for post-apexd processes) is hidden from pre-apexd
processes by changing propagation type of the mount points to 'private'
and execute the pre-apexd processes with a new mount namespace using
unshare(2). If a pre-apexd process crashes and re-launched after the
apexd is on, the process still gets the bootstrap bionic by unmounting
the runtime bionic which effectively un-hides the previous bind-mounts
targeting the bootstrap bionic.

Bug: 120266448
Test: device boots
Test: cat /proc/`pidof zygote`/mountinfo shows that
/system/lib/{libc|libdl|libm}.so and /system/bin/linker are from the
runtime APEX
Test: cat /proc/'pidof vold`/mountinfo shows that the same mount points
are from system partition.

Change-Id: I7ca67755dc0656c0f0c834ba94bf23ba9b1aca68
2019-01-11 15:17:04 +09:00

1243 lines
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/*
* Copyright (C) 2008 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "builtins.h"
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <fts.h>
#include <glob.h>
#include <linux/loop.h>
#include <linux/module.h>
#include <mntent.h>
#include <net/if.h>
#include <sched.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mount.h>
#include <sys/resource.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/system_properties.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <android-base/chrono_utils.h>
#include <android-base/file.h>
#include <android-base/logging.h>
#include <android-base/parseint.h>
#include <android-base/properties.h>
#include <android-base/stringprintf.h>
#include <android-base/strings.h>
#include <android-base/unique_fd.h>
#include <bootloader_message/bootloader_message.h>
#include <cutils/android_reboot.h>
#include <fs_mgr.h>
#include <fscrypt/fscrypt.h>
#include <fscrypt/fscrypt_init_extensions.h>
#include <selinux/android.h>
#include <selinux/label.h>
#include <selinux/selinux.h>
#include <system/thread_defs.h>
#include "action_manager.h"
#include "bootchart.h"
#include "init.h"
#include "parser.h"
#include "property_service.h"
#include "reboot.h"
#include "rlimit_parser.h"
#include "selinux.h"
#include "service.h"
#include "subcontext.h"
#include "util.h"
using namespace std::literals::string_literals;
using android::base::unique_fd;
#define chmod DO_NOT_USE_CHMOD_USE_FCHMODAT_SYMLINK_NOFOLLOW
namespace android {
namespace init {
static constexpr std::chrono::nanoseconds kCommandRetryTimeout = 5s;
static Result<Success> reboot_into_recovery(const std::vector<std::string>& options) {
LOG(ERROR) << "Rebooting into recovery";
std::string err;
if (!write_bootloader_message(options, &err)) {
return Error() << "Failed to set bootloader message: " << err;
}
property_set("sys.powerctl", "reboot,recovery");
return Success();
}
template <typename F>
static void ForEachServiceInClass(const std::string& classname, F function) {
for (const auto& service : ServiceList::GetInstance()) {
if (service->classnames().count(classname)) std::invoke(function, service);
}
}
static Result<Success> do_class_start(const BuiltinArguments& args) {
// Do not start a class if it has a property persist.dont_start_class.CLASS set to 1.
if (android::base::GetBoolProperty("persist.init.dont_start_class." + args[1], false))
return Success();
// Starting a class does not start services which are explicitly disabled.
// They must be started individually.
for (const auto& service : ServiceList::GetInstance()) {
if (service->classnames().count(args[1])) {
if (auto result = service->StartIfNotDisabled(); !result) {
LOG(ERROR) << "Could not start service '" << service->name()
<< "' as part of class '" << args[1] << "': " << result.error();
}
}
}
return Success();
}
static Result<Success> do_class_stop(const BuiltinArguments& args) {
ForEachServiceInClass(args[1], &Service::Stop);
return Success();
}
static Result<Success> do_class_reset(const BuiltinArguments& args) {
ForEachServiceInClass(args[1], &Service::Reset);
return Success();
}
static Result<Success> do_class_restart(const BuiltinArguments& args) {
// Do not restart a class if it has a property persist.dont_start_class.CLASS set to 1.
if (android::base::GetBoolProperty("persist.init.dont_start_class." + args[1], false))
return Success();
ForEachServiceInClass(args[1], &Service::Restart);
return Success();
}
static Result<Success> do_domainname(const BuiltinArguments& args) {
if (auto result = WriteFile("/proc/sys/kernel/domainname", args[1]); !result) {
return Error() << "Unable to write to /proc/sys/kernel/domainname: " << result.error();
}
return Success();
}
static Result<Success> do_enable(const BuiltinArguments& args) {
Service* svc = ServiceList::GetInstance().FindService(args[1]);
if (!svc) return Error() << "Could not find service";
if (auto result = svc->Enable(); !result) {
return Error() << "Could not enable service: " << result.error();
}
return Success();
}
static Result<Success> do_exec(const BuiltinArguments& args) {
auto service = Service::MakeTemporaryOneshotService(args.args);
if (!service) {
return Error() << "Could not create exec service";
}
if (auto result = service->ExecStart(); !result) {
return Error() << "Could not start exec service: " << result.error();
}
ServiceList::GetInstance().AddService(std::move(service));
return Success();
}
static Result<Success> do_exec_background(const BuiltinArguments& args) {
auto service = Service::MakeTemporaryOneshotService(args.args);
if (!service) {
return Error() << "Could not create exec background service";
}
if (auto result = service->Start(); !result) {
return Error() << "Could not start exec background service: " << result.error();
}
ServiceList::GetInstance().AddService(std::move(service));
return Success();
}
static Result<Success> do_exec_start(const BuiltinArguments& args) {
Service* service = ServiceList::GetInstance().FindService(args[1]);
if (!service) {
return Error() << "Service not found";
}
if (auto result = service->ExecStart(); !result) {
return Error() << "Could not start exec service: " << result.error();
}
return Success();
}
static Result<Success> do_export(const BuiltinArguments& args) {
if (setenv(args[1].c_str(), args[2].c_str(), 1) == -1) {
return ErrnoError() << "setenv() failed";
}
return Success();
}
static Result<Success> do_hostname(const BuiltinArguments& args) {
if (auto result = WriteFile("/proc/sys/kernel/hostname", args[1]); !result) {
return Error() << "Unable to write to /proc/sys/kernel/hostname: " << result.error();
}
return Success();
}
static Result<Success> do_ifup(const BuiltinArguments& args) {
struct ifreq ifr;
strlcpy(ifr.ifr_name, args[1].c_str(), IFNAMSIZ);
unique_fd s(TEMP_FAILURE_RETRY(socket(AF_INET, SOCK_DGRAM, 0)));
if (s < 0) return ErrnoError() << "opening socket failed";
if (ioctl(s, SIOCGIFFLAGS, &ifr) < 0) {
return ErrnoError() << "ioctl(..., SIOCGIFFLAGS, ...) failed";
}
ifr.ifr_flags |= IFF_UP;
if (ioctl(s, SIOCSIFFLAGS, &ifr) < 0) {
return ErrnoError() << "ioctl(..., SIOCSIFFLAGS, ...) failed";
}
return Success();
}
static Result<Success> do_insmod(const BuiltinArguments& args) {
int flags = 0;
auto it = args.begin() + 1;
if (!(*it).compare("-f")) {
flags = MODULE_INIT_IGNORE_VERMAGIC | MODULE_INIT_IGNORE_MODVERSIONS;
it++;
}
std::string filename = *it++;
std::string options = android::base::Join(std::vector<std::string>(it, args.end()), ' ');
unique_fd fd(TEMP_FAILURE_RETRY(open(filename.c_str(), O_RDONLY | O_NOFOLLOW | O_CLOEXEC)));
if (fd == -1) return ErrnoError() << "open(\"" << filename << "\") failed";
int rc = syscall(__NR_finit_module, fd.get(), options.c_str(), flags);
if (rc == -1) return ErrnoError() << "finit_module for \"" << filename << "\" failed";
return Success();
}
static Result<Success> do_interface_restart(const BuiltinArguments& args) {
Service* svc = ServiceList::GetInstance().FindInterface(args[1]);
if (!svc) return Error() << "interface " << args[1] << " not found";
svc->Restart();
return Success();
}
static Result<Success> do_interface_start(const BuiltinArguments& args) {
Service* svc = ServiceList::GetInstance().FindInterface(args[1]);
if (!svc) return Error() << "interface " << args[1] << " not found";
if (auto result = svc->Start(); !result) {
return Error() << "Could not start interface: " << result.error();
}
return Success();
}
static Result<Success> do_interface_stop(const BuiltinArguments& args) {
Service* svc = ServiceList::GetInstance().FindInterface(args[1]);
if (!svc) return Error() << "interface " << args[1] << " not found";
svc->Stop();
return Success();
}
// mkdir <path> [mode] [owner] [group]
static Result<Success> do_mkdir(const BuiltinArguments& args) {
mode_t mode = 0755;
if (args.size() >= 3) {
mode = std::strtoul(args[2].c_str(), 0, 8);
}
if (!make_dir(args[1], mode)) {
/* chmod in case the directory already exists */
if (errno == EEXIST) {
if (fchmodat(AT_FDCWD, args[1].c_str(), mode, AT_SYMLINK_NOFOLLOW) == -1) {
return ErrnoError() << "fchmodat() failed";
}
} else {
return ErrnoError() << "mkdir() failed";
}
}
if (args.size() >= 4) {
auto uid = DecodeUid(args[3]);
if (!uid) {
return Error() << "Unable to decode UID for '" << args[3] << "': " << uid.error();
}
Result<gid_t> gid = -1;
if (args.size() == 5) {
gid = DecodeUid(args[4]);
if (!gid) {
return Error() << "Unable to decode GID for '" << args[3] << "': " << gid.error();
}
}
if (lchown(args[1].c_str(), *uid, *gid) == -1) {
return ErrnoError() << "lchown failed";
}
/* chown may have cleared S_ISUID and S_ISGID, chmod again */
if (mode & (S_ISUID | S_ISGID)) {
if (fchmodat(AT_FDCWD, args[1].c_str(), mode, AT_SYMLINK_NOFOLLOW) == -1) {
return ErrnoError() << "fchmodat failed";
}
}
}
if (fscrypt_is_native()) {
if (fscrypt_set_directory_policy(args[1].c_str())) {
return reboot_into_recovery(
{"--prompt_and_wipe_data", "--reason=set_policy_failed:"s + args[1]});
}
}
return Success();
}
/* umount <path> */
static Result<Success> do_umount(const BuiltinArguments& args) {
if (umount(args[1].c_str()) < 0) {
return ErrnoError() << "umount() failed";
}
return Success();
}
static struct {
const char *name;
unsigned flag;
} mount_flags[] = {
{ "noatime", MS_NOATIME },
{ "noexec", MS_NOEXEC },
{ "nosuid", MS_NOSUID },
{ "nodev", MS_NODEV },
{ "nodiratime", MS_NODIRATIME },
{ "ro", MS_RDONLY },
{ "rw", 0 },
{ "remount", MS_REMOUNT },
{ "bind", MS_BIND },
{ "rec", MS_REC },
{ "unbindable", MS_UNBINDABLE },
{ "private", MS_PRIVATE },
{ "slave", MS_SLAVE },
{ "shared", MS_SHARED },
{ "defaults", 0 },
{ 0, 0 },
};
#define DATA_MNT_POINT "/data"
/* mount <type> <device> <path> <flags ...> <options> */
static Result<Success> do_mount(const BuiltinArguments& args) {
const char* options = nullptr;
unsigned flags = 0;
bool wait = false;
for (size_t na = 4; na < args.size(); na++) {
size_t i;
for (i = 0; mount_flags[i].name; i++) {
if (!args[na].compare(mount_flags[i].name)) {
flags |= mount_flags[i].flag;
break;
}
}
if (!mount_flags[i].name) {
if (!args[na].compare("wait")) {
wait = true;
// If our last argument isn't a flag, wolf it up as an option string.
} else if (na + 1 == args.size()) {
options = args[na].c_str();
}
}
}
const char* system = args[1].c_str();
const char* source = args[2].c_str();
const char* target = args[3].c_str();
if (android::base::StartsWith(source, "loop@")) {
int mode = (flags & MS_RDONLY) ? O_RDONLY : O_RDWR;
unique_fd fd(TEMP_FAILURE_RETRY(open(source + 5, mode | O_CLOEXEC)));
if (fd < 0) return ErrnoError() << "open(" << source + 5 << ", " << mode << ") failed";
for (size_t n = 0;; n++) {
std::string tmp = android::base::StringPrintf("/dev/block/loop%zu", n);
unique_fd loop(TEMP_FAILURE_RETRY(open(tmp.c_str(), mode | O_CLOEXEC)));
if (loop < 0) return ErrnoError() << "open(" << tmp << ", " << mode << ") failed";
loop_info info;
/* if it is a blank loop device */
if (ioctl(loop, LOOP_GET_STATUS, &info) < 0 && errno == ENXIO) {
/* if it becomes our loop device */
if (ioctl(loop, LOOP_SET_FD, fd.get()) >= 0) {
if (mount(tmp.c_str(), target, system, flags, options) < 0) {
ioctl(loop, LOOP_CLR_FD, 0);
return ErrnoError() << "mount() failed";
}
return Success();
}
}
}
return Error() << "out of loopback devices";
} else {
if (wait)
wait_for_file(source, kCommandRetryTimeout);
if (mount(source, target, system, flags, options) < 0) {
return ErrnoError() << "mount() failed";
}
}
return Success();
}
/* Imports .rc files from the specified paths. Default ones are applied if none is given.
*
* start_index: index of the first path in the args list
*/
static void import_late(const std::vector<std::string>& args, size_t start_index, size_t end_index) {
auto& action_manager = ActionManager::GetInstance();
auto& service_list = ServiceList::GetInstance();
Parser parser = CreateParser(action_manager, service_list);
if (end_index <= start_index) {
// Fallbacks for partitions on which early mount isn't enabled.
for (const auto& path : late_import_paths) {
parser.ParseConfig(path);
}
late_import_paths.clear();
} else {
for (size_t i = start_index; i < end_index; ++i) {
parser.ParseConfig(args[i]);
}
}
// Turning this on and letting the INFO logging be discarded adds 0.2s to
// Nexus 9 boot time, so it's disabled by default.
if (false) DumpState();
}
/* mount_fstab
*
* Call fs_mgr_mount_all() to mount the given fstab
*/
static Result<int> mount_fstab(const char* fstabfile, int mount_mode) {
/*
* Call fs_mgr_mount_all() to mount all filesystems. We fork(2) and
* do the call in the child to provide protection to the main init
* process if anything goes wrong (crash or memory leak), and wait for
* the child to finish in the parent.
*/
pid_t pid = fork();
if (pid > 0) {
/* Parent. Wait for the child to return */
int status;
int wp_ret = TEMP_FAILURE_RETRY(waitpid(pid, &status, 0));
if (wp_ret == -1) {
// Unexpected error code. We will continue anyway.
PLOG(WARNING) << "waitpid failed";
}
if (WIFEXITED(status)) {
return WEXITSTATUS(status);
} else {
return Error() << "child aborted";
}
} else if (pid == 0) {
/* child, call fs_mgr_mount_all() */
// So we can always see what fs_mgr_mount_all() does.
// Only needed if someone explicitly changes the default log level in their init.rc.
android::base::ScopedLogSeverity info(android::base::INFO);
Fstab fstab;
ReadFstabFromFile(fstabfile, &fstab);
int child_ret = fs_mgr_mount_all(&fstab, mount_mode);
if (child_ret == -1) {
PLOG(ERROR) << "fs_mgr_mount_all returned an error";
}
_exit(child_ret);
} else {
return Error() << "fork() failed";
}
}
/* Queue event based on fs_mgr return code.
*
* code: return code of fs_mgr_mount_all
*
* This function might request a reboot, in which case it will
* not return.
*
* return code is processed based on input code
*/
static Result<Success> queue_fs_event(int code) {
if (code == FS_MGR_MNTALL_DEV_NEEDS_ENCRYPTION) {
ActionManager::GetInstance().QueueEventTrigger("encrypt");
return Success();
} else if (code == FS_MGR_MNTALL_DEV_MIGHT_BE_ENCRYPTED) {
property_set("ro.crypto.state", "encrypted");
property_set("ro.crypto.type", "block");
ActionManager::GetInstance().QueueEventTrigger("defaultcrypto");
return Success();
} else if (code == FS_MGR_MNTALL_DEV_NOT_ENCRYPTED) {
property_set("ro.crypto.state", "unencrypted");
ActionManager::GetInstance().QueueEventTrigger("nonencrypted");
return Success();
} else if (code == FS_MGR_MNTALL_DEV_NOT_ENCRYPTABLE) {
property_set("ro.crypto.state", "unsupported");
ActionManager::GetInstance().QueueEventTrigger("nonencrypted");
return Success();
} else if (code == FS_MGR_MNTALL_DEV_NEEDS_RECOVERY) {
/* Setup a wipe via recovery, and reboot into recovery */
PLOG(ERROR) << "fs_mgr_mount_all suggested recovery, so wiping data via recovery.";
const std::vector<std::string> options = {"--wipe_data", "--reason=fs_mgr_mount_all" };
return reboot_into_recovery(options);
/* If reboot worked, there is no return. */
} else if (code == FS_MGR_MNTALL_DEV_FILE_ENCRYPTED) {
if (fscrypt_install_keyring()) {
return Error() << "fscrypt_install_keyring() failed";
}
property_set("ro.crypto.state", "encrypted");
property_set("ro.crypto.type", "file");
// Although encrypted, we have device key, so we do not need to
// do anything different from the nonencrypted case.
ActionManager::GetInstance().QueueEventTrigger("nonencrypted");
return Success();
} else if (code == FS_MGR_MNTALL_DEV_IS_METADATA_ENCRYPTED) {
if (fscrypt_install_keyring()) {
return Error() << "fscrypt_install_keyring() failed";
}
property_set("ro.crypto.state", "encrypted");
property_set("ro.crypto.type", "file");
// Although encrypted, vold has already set the device up, so we do not need to
// do anything different from the nonencrypted case.
ActionManager::GetInstance().QueueEventTrigger("nonencrypted");
return Success();
} else if (code == FS_MGR_MNTALL_DEV_NEEDS_METADATA_ENCRYPTION) {
if (fscrypt_install_keyring()) {
return Error() << "fscrypt_install_keyring() failed";
}
property_set("ro.crypto.state", "encrypted");
property_set("ro.crypto.type", "file");
// Although encrypted, vold has already set the device up, so we do not need to
// do anything different from the nonencrypted case.
ActionManager::GetInstance().QueueEventTrigger("nonencrypted");
return Success();
} else if (code > 0) {
Error() << "fs_mgr_mount_all() returned unexpected error " << code;
}
/* else ... < 0: error */
return Error() << "Invalid code: " << code;
}
/* mount_all <fstab> [ <path> ]* [--<options>]*
*
* This function might request a reboot, in which case it will
* not return.
*/
static Result<Success> do_mount_all(const BuiltinArguments& args) {
std::size_t na = 0;
bool import_rc = true;
bool queue_event = true;
int mount_mode = MOUNT_MODE_DEFAULT;
const char* fstabfile = args[1].c_str();
std::size_t path_arg_end = args.size();
const char* prop_post_fix = "default";
for (na = args.size() - 1; na > 1; --na) {
if (args[na] == "--early") {
path_arg_end = na;
queue_event = false;
mount_mode = MOUNT_MODE_EARLY;
prop_post_fix = "early";
} else if (args[na] == "--late") {
path_arg_end = na;
import_rc = false;
mount_mode = MOUNT_MODE_LATE;
prop_post_fix = "late";
}
}
std::string prop_name = "ro.boottime.init.mount_all."s + prop_post_fix;
android::base::Timer t;
auto mount_fstab_return_code = mount_fstab(fstabfile, mount_mode);
if (!mount_fstab_return_code) {
return Error() << "mount_fstab() failed " << mount_fstab_return_code.error();
}
property_set(prop_name, std::to_string(t.duration().count()));
if (import_rc) {
/* Paths of .rc files are specified at the 2nd argument and beyond */
import_late(args.args, 2, path_arg_end);
}
if (queue_event) {
/* queue_fs_event will queue event based on mount_fstab return code
* and return processed return code*/
auto queue_fs_result = queue_fs_event(*mount_fstab_return_code);
if (!queue_fs_result) {
return Error() << "queue_fs_event() failed: " << queue_fs_result.error();
}
}
return Success();
}
static Result<Success> do_swapon_all(const BuiltinArguments& args) {
Fstab fstab;
if (!ReadFstabFromFile(args[1], &fstab)) {
return Error() << "Could not read fstab '" << args[1] << "'";
}
if (!fs_mgr_swapon_all(fstab)) {
return Error() << "fs_mgr_swapon_all() failed";
}
return Success();
}
static Result<Success> do_setprop(const BuiltinArguments& args) {
property_set(args[1], args[2]);
return Success();
}
static Result<Success> do_setrlimit(const BuiltinArguments& args) {
auto rlimit = ParseRlimit(args.args);
if (!rlimit) return rlimit.error();
if (setrlimit(rlimit->first, &rlimit->second) == -1) {
return ErrnoError() << "setrlimit failed";
}
return Success();
}
static Result<Success> do_start(const BuiltinArguments& args) {
Service* svc = ServiceList::GetInstance().FindService(args[1]);
if (!svc) return Error() << "service " << args[1] << " not found";
if (auto result = svc->Start(); !result) {
return Error() << "Could not start service: " << result.error();
}
return Success();
}
static Result<Success> do_stop(const BuiltinArguments& args) {
Service* svc = ServiceList::GetInstance().FindService(args[1]);
if (!svc) return Error() << "service " << args[1] << " not found";
svc->Stop();
return Success();
}
static Result<Success> do_restart(const BuiltinArguments& args) {
Service* svc = ServiceList::GetInstance().FindService(args[1]);
if (!svc) return Error() << "service " << args[1] << " not found";
svc->Restart();
return Success();
}
static Result<Success> do_trigger(const BuiltinArguments& args) {
ActionManager::GetInstance().QueueEventTrigger(args[1]);
return Success();
}
static int MakeSymlink(const std::string& target, const std::string& linkpath) {
std::string secontext;
// Passing 0 for mode should work.
if (SelabelLookupFileContext(linkpath, 0, &secontext) && !secontext.empty()) {
setfscreatecon(secontext.c_str());
}
int rc = symlink(target.c_str(), linkpath.c_str());
if (!secontext.empty()) {
int save_errno = errno;
setfscreatecon(nullptr);
errno = save_errno;
}
return rc;
}
static Result<Success> do_symlink(const BuiltinArguments& args) {
if (MakeSymlink(args[1], args[2]) < 0) {
// The symlink builtin is often used to create symlinks for older devices to be backwards
// compatible with new paths, therefore we skip reporting this error.
if (errno == EEXIST && android::base::GetMinimumLogSeverity() > android::base::DEBUG) {
return Success();
}
return ErrnoError() << "symlink() failed";
}
return Success();
}
static Result<Success> do_rm(const BuiltinArguments& args) {
if (unlink(args[1].c_str()) < 0) {
return ErrnoError() << "unlink() failed";
}
return Success();
}
static Result<Success> do_rmdir(const BuiltinArguments& args) {
if (rmdir(args[1].c_str()) < 0) {
return ErrnoError() << "rmdir() failed";
}
return Success();
}
static Result<Success> do_sysclktz(const BuiltinArguments& args) {
struct timezone tz = {};
if (!android::base::ParseInt(args[1], &tz.tz_minuteswest)) {
return Error() << "Unable to parse mins_west_of_gmt";
}
if (settimeofday(nullptr, &tz) == -1) {
return ErrnoError() << "settimeofday() failed";
}
return Success();
}
static Result<Success> do_verity_load_state(const BuiltinArguments& args) {
int mode = -1;
bool loaded = fs_mgr_load_verity_state(&mode);
if (loaded && mode != VERITY_MODE_DEFAULT) {
ActionManager::GetInstance().QueueEventTrigger("verity-logging");
}
if (!loaded) return Error() << "Could not load verity state";
return Success();
}
static Result<Success> do_verity_update_state(const BuiltinArguments& args) {
if (!fs_mgr_update_verity_state([](const std::string& mount_point, int mode) {
property_set("partition." + mount_point + ".verified", std::to_string(mode));
})) {
return Error() << "fs_mgr_update_verity_state() failed";
}
return Success();
}
static Result<Success> do_write(const BuiltinArguments& args) {
if (auto result = WriteFile(args[1], args[2]); !result) {
return Error() << "Unable to write to file '" << args[1] << "': " << result.error();
}
return Success();
}
static Result<Success> readahead_file(const std::string& filename, bool fully) {
android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(filename.c_str(), O_RDONLY)));
if (fd == -1) {
return ErrnoError() << "Error opening file";
}
if (posix_fadvise(fd, 0, 0, POSIX_FADV_WILLNEED)) {
return ErrnoError() << "Error posix_fadvise file";
}
if (readahead(fd, 0, std::numeric_limits<size_t>::max())) {
return ErrnoError() << "Error readahead file";
}
if (fully) {
char buf[BUFSIZ];
ssize_t n;
while ((n = TEMP_FAILURE_RETRY(read(fd, &buf[0], sizeof(buf)))) > 0) {
}
if (n != 0) {
return ErrnoError() << "Error reading file";
}
}
return Success();
}
static Result<Success> do_readahead(const BuiltinArguments& args) {
struct stat sb;
if (stat(args[1].c_str(), &sb)) {
return ErrnoError() << "Error opening " << args[1];
}
bool readfully = false;
if (args.size() == 3 && args[2] == "--fully") {
readfully = true;
}
// We will do readahead in a forked process in order not to block init
// since it may block while it reads the
// filesystem metadata needed to locate the requested blocks. This
// occurs frequently with ext[234] on large files using indirect blocks
// instead of extents, giving the appearance that the call blocks until
// the requested data has been read.
pid_t pid = fork();
if (pid == 0) {
if (setpriority(PRIO_PROCESS, 0, static_cast<int>(ANDROID_PRIORITY_LOWEST)) != 0) {
PLOG(WARNING) << "setpriority failed";
}
if (android_set_ioprio(0, IoSchedClass_IDLE, 7)) {
PLOG(WARNING) << "ioprio_get failed";
}
android::base::Timer t;
if (S_ISREG(sb.st_mode)) {
if (auto result = readahead_file(args[1], readfully); !result) {
LOG(WARNING) << "Unable to readahead '" << args[1] << "': " << result.error();
_exit(EXIT_FAILURE);
}
} else if (S_ISDIR(sb.st_mode)) {
char* paths[] = {const_cast<char*>(args[1].data()), nullptr};
std::unique_ptr<FTS, decltype(&fts_close)> fts(
fts_open(paths, FTS_PHYSICAL | FTS_NOCHDIR | FTS_XDEV, nullptr), fts_close);
if (!fts) {
PLOG(ERROR) << "Error opening directory: " << args[1];
_exit(EXIT_FAILURE);
}
// Traverse the entire hierarchy and do readahead
for (FTSENT* ftsent = fts_read(fts.get()); ftsent != nullptr;
ftsent = fts_read(fts.get())) {
if (ftsent->fts_info & FTS_F) {
const std::string filename = ftsent->fts_accpath;
if (auto result = readahead_file(filename, readfully); !result) {
LOG(WARNING)
<< "Unable to readahead '" << filename << "': " << result.error();
}
}
}
}
LOG(INFO) << "Readahead " << args[1] << " took " << t << " asynchronously";
_exit(0);
} else if (pid < 0) {
return ErrnoError() << "Fork failed";
}
return Success();
}
static Result<Success> do_copy(const BuiltinArguments& args) {
auto file_contents = ReadFile(args[1]);
if (!file_contents) {
return Error() << "Could not read input file '" << args[1] << "': " << file_contents.error();
}
if (auto result = WriteFile(args[2], *file_contents); !result) {
return Error() << "Could not write to output file '" << args[2] << "': " << result.error();
}
return Success();
}
static Result<Success> do_chown(const BuiltinArguments& args) {
auto uid = DecodeUid(args[1]);
if (!uid) {
return Error() << "Unable to decode UID for '" << args[1] << "': " << uid.error();
}
// GID is optional and pushes the index of path out by one if specified.
const std::string& path = (args.size() == 4) ? args[3] : args[2];
Result<gid_t> gid = -1;
if (args.size() == 4) {
gid = DecodeUid(args[2]);
if (!gid) {
return Error() << "Unable to decode GID for '" << args[2] << "': " << gid.error();
}
}
if (lchown(path.c_str(), *uid, *gid) == -1) {
return ErrnoError() << "lchown() failed";
}
return Success();
}
static mode_t get_mode(const char *s) {
mode_t mode = 0;
while (*s) {
if (*s >= '0' && *s <= '7') {
mode = (mode<<3) | (*s-'0');
} else {
return -1;
}
s++;
}
return mode;
}
static Result<Success> do_chmod(const BuiltinArguments& args) {
mode_t mode = get_mode(args[1].c_str());
if (fchmodat(AT_FDCWD, args[2].c_str(), mode, AT_SYMLINK_NOFOLLOW) < 0) {
return ErrnoError() << "fchmodat() failed";
}
return Success();
}
static Result<Success> do_restorecon(const BuiltinArguments& args) {
int ret = 0;
struct flag_type {const char* name; int value;};
static const flag_type flags[] = {
{"--recursive", SELINUX_ANDROID_RESTORECON_RECURSE},
{"--skip-ce", SELINUX_ANDROID_RESTORECON_SKIPCE},
{"--cross-filesystems", SELINUX_ANDROID_RESTORECON_CROSS_FILESYSTEMS},
{0, 0}
};
int flag = 0;
bool in_flags = true;
for (size_t i = 1; i < args.size(); ++i) {
if (android::base::StartsWith(args[i], "--")) {
if (!in_flags) {
return Error() << "flags must precede paths";
}
bool found = false;
for (size_t j = 0; flags[j].name; ++j) {
if (args[i] == flags[j].name) {
flag |= flags[j].value;
found = true;
break;
}
}
if (!found) {
return Error() << "bad flag " << args[i];
}
} else {
in_flags = false;
if (selinux_android_restorecon(args[i].c_str(), flag) < 0) {
ret = errno;
}
}
}
if (ret) return ErrnoError() << "selinux_android_restorecon() failed";
return Success();
}
static Result<Success> do_restorecon_recursive(const BuiltinArguments& args) {
std::vector<std::string> non_const_args(args.args);
non_const_args.insert(std::next(non_const_args.begin()), "--recursive");
return do_restorecon({std::move(non_const_args), args.context});
}
static Result<Success> do_loglevel(const BuiltinArguments& args) {
// TODO: support names instead/as well?
int log_level = -1;
android::base::ParseInt(args[1], &log_level);
android::base::LogSeverity severity;
switch (log_level) {
case 7: severity = android::base::DEBUG; break;
case 6: severity = android::base::INFO; break;
case 5:
case 4: severity = android::base::WARNING; break;
case 3: severity = android::base::ERROR; break;
case 2:
case 1:
case 0: severity = android::base::FATAL; break;
default:
return Error() << "invalid log level " << log_level;
}
android::base::SetMinimumLogSeverity(severity);
return Success();
}
static Result<Success> do_load_persist_props(const BuiltinArguments& args) {
load_persist_props();
return Success();
}
static Result<Success> do_load_system_props(const BuiltinArguments& args) {
load_system_props();
return Success();
}
static Result<Success> do_wait(const BuiltinArguments& args) {
auto timeout = kCommandRetryTimeout;
if (args.size() == 3) {
int timeout_int;
if (!android::base::ParseInt(args[2], &timeout_int)) {
return Error() << "failed to parse timeout";
}
timeout = std::chrono::seconds(timeout_int);
}
if (wait_for_file(args[1].c_str(), timeout) != 0) {
return Error() << "wait_for_file() failed";
}
return Success();
}
static Result<Success> do_wait_for_prop(const BuiltinArguments& args) {
const char* name = args[1].c_str();
const char* value = args[2].c_str();
size_t value_len = strlen(value);
if (!IsLegalPropertyName(name)) {
return Error() << "IsLegalPropertyName(" << name << ") failed";
}
if (value_len >= PROP_VALUE_MAX) {
return Error() << "value too long";
}
if (!start_waiting_for_property(name, value)) {
return Error() << "already waiting for a property";
}
return Success();
}
static bool is_file_crypto() {
return android::base::GetProperty("ro.crypto.type", "") == "file";
}
static Result<Success> ExecWithRebootOnFailure(const std::string& reboot_reason,
const BuiltinArguments& args) {
auto service = Service::MakeTemporaryOneshotService(args.args);
if (!service) {
return Error() << "Could not create exec service";
}
service->AddReapCallback([reboot_reason](const siginfo_t& siginfo) {
if (siginfo.si_code != CLD_EXITED || siginfo.si_status != 0) {
if (fscrypt_is_native()) {
LOG(ERROR) << "Rebooting into recovery, reason: " << reboot_reason;
if (auto result = reboot_into_recovery(
{"--prompt_and_wipe_data", "--reason="s + reboot_reason});
!result) {
LOG(FATAL) << "Could not reboot into recovery: " << result.error();
}
} else {
LOG(ERROR) << "Failure (reboot suppressed): " << reboot_reason;
}
}
});
if (auto result = service->ExecStart(); !result) {
return Error() << "Could not start exec service: " << result.error();
}
ServiceList::GetInstance().AddService(std::move(service));
return Success();
}
static Result<Success> do_installkey(const BuiltinArguments& args) {
if (!is_file_crypto()) return Success();
auto unencrypted_dir = args[1] + fscrypt_unencrypted_folder;
if (!make_dir(unencrypted_dir, 0700) && errno != EEXIST) {
return ErrnoError() << "Failed to create " << unencrypted_dir;
}
return ExecWithRebootOnFailure(
"enablefilecrypto_failed",
{{"exec", "/system/bin/vdc", "--wait", "cryptfs", "enablefilecrypto"}, args.context});
}
static Result<Success> do_init_user0(const BuiltinArguments& args) {
return ExecWithRebootOnFailure(
"init_user0_failed",
{{"exec", "/system/bin/vdc", "--wait", "cryptfs", "init_user0"}, args.context});
}
static Result<Success> do_parse_apex_configs(const BuiltinArguments& args) {
glob_t glob_result;
// @ is added to filter out the later paths, which are bind mounts of the places
// where the APEXes are really mounted at. Otherwise, we will parse the
// same file twice.
static constexpr char glob_pattern[] = "/apex/*@*/etc/*.rc";
const int ret = glob(glob_pattern, GLOB_MARK, nullptr, &glob_result);
if (ret != 0 && ret != GLOB_NOMATCH) {
globfree(&glob_result);
return Error() << "glob pattern '" << glob_pattern << "' failed";
}
std::vector<std::string> configs;
Parser parser = CreateServiceOnlyParser(ServiceList::GetInstance());
for (size_t i = 0; i < glob_result.gl_pathc; i++) {
configs.emplace_back(glob_result.gl_pathv[i]);
}
globfree(&glob_result);
bool success = true;
for (const auto& c : configs) {
if (c.back() == '/') {
// skip if directory
continue;
}
success &= parser.ParseConfigFile(c);
}
ServiceList::GetInstance().MarkServicesUpdate();
if (success) {
return Success();
} else {
return Error() << "Could not parse apex configs";
}
}
static Result<Success> bind_mount_file(const char* source, const char* mount_point,
bool remount_private) {
if (remount_private && mount(nullptr, mount_point, nullptr, MS_PRIVATE, nullptr) == -1) {
return ErrnoError() << "Could not change " << mount_point << " to a private mount point";
}
if (mount(source, mount_point, nullptr, MS_BIND, nullptr) == -1) {
return ErrnoError() << "Could not bind-mount " << source << " to " << mount_point;
}
return Success();
}
static Result<Success> bind_mount_bionic(const char* linker_source, const char* lib_dir_source,
const char* linker_mount_point, const char* lib_mount_dir,
bool remount_private) {
if (access(linker_source, F_OK) != 0) {
return Success();
}
if (auto result = bind_mount_file(linker_source, linker_mount_point, remount_private);
!result) {
return result;
}
for (auto libname : kBionicLibFileNames) {
std::string mount_point = lib_mount_dir + libname;
std::string source = lib_dir_source + libname;
if (auto result = bind_mount_file(source.c_str(), mount_point.c_str(), remount_private);
!result) {
return result;
}
}
return Success();
}
// The bootstrap bionic libs and the bootstrap linker are bind-mounted to
// the mount points for pre-apexd processes.
static Result<Success> do_prepare_bootstrap_bionic(const BuiltinArguments& args) {
static bool prepare_bootstrap_bionic_done = false;
if (prepare_bootstrap_bionic_done) {
return Error() << "prepare_bootstrap_bionic was already executed. Cannot be executed again";
}
if (auto result = bind_mount_bionic(kBootstrapLinkerPath, kBootstrapBionicLibsDir,
kLinkerMountPoint, kBionicLibsMountPointDir, false);
!result) {
return result;
}
if (auto result = bind_mount_bionic(kBootstrapLinkerPath64, kBootstrapBionicLibsDir64,
kLinkerMountPoint64, kBionicLibsMountPointDir64, false);
!result) {
return result;
}
LOG(INFO) << "prepare_bootstrap_bionic done";
prepare_bootstrap_bionic_done = true;
return Success();
}
// The bionic libs and the dynamic linker from the runtime APEX are bind-mounted
// to the mount points. As a result, the previous mounts done by
// prepare_bootstrap_bionic become hidden.
static Result<Success> do_setup_runtime_bionic(const BuiltinArguments& args) {
static bool setup_runtime_bionic_done = false;
if (setup_runtime_bionic_done) {
return Error() << "setup_runtime_bionic was already executed. Cannot be executed again";
}
if (auto result = bind_mount_bionic(kRuntimeLinkerPath, kRuntimeBionicLibsDir,
kLinkerMountPoint, kBionicLibsMountPointDir, true);
!result) {
return result;
}
if (auto result = bind_mount_bionic(kRuntimeLinkerPath64, kRuntimeBionicLibsDir64,
kLinkerMountPoint64, kBionicLibsMountPointDir64, true);
!result) {
return result;
}
ServiceList::GetInstance().MarkRuntimeAvailable();
LOG(INFO) << "setup_runtime_bionic done";
setup_runtime_bionic_done = true;
return Success();
}
// Builtin-function-map start
const BuiltinFunctionMap::Map& BuiltinFunctionMap::map() const {
constexpr std::size_t kMax = std::numeric_limits<std::size_t>::max();
// clang-format off
static const Map builtin_functions = {
{"bootchart", {1, 1, {false, do_bootchart}}},
{"chmod", {2, 2, {true, do_chmod}}},
{"chown", {2, 3, {true, do_chown}}},
{"class_reset", {1, 1, {false, do_class_reset}}},
{"class_restart", {1, 1, {false, do_class_restart}}},
{"class_start", {1, 1, {false, do_class_start}}},
{"class_stop", {1, 1, {false, do_class_stop}}},
{"copy", {2, 2, {true, do_copy}}},
{"domainname", {1, 1, {true, do_domainname}}},
{"enable", {1, 1, {false, do_enable}}},
{"exec", {1, kMax, {false, do_exec}}},
{"exec_background", {1, kMax, {false, do_exec_background}}},
{"exec_start", {1, 1, {false, do_exec_start}}},
{"export", {2, 2, {false, do_export}}},
{"hostname", {1, 1, {true, do_hostname}}},
{"ifup", {1, 1, {true, do_ifup}}},
{"init_user0", {0, 0, {false, do_init_user0}}},
{"insmod", {1, kMax, {true, do_insmod}}},
{"installkey", {1, 1, {false, do_installkey}}},
{"interface_restart", {1, 1, {false, do_interface_restart}}},
{"interface_start", {1, 1, {false, do_interface_start}}},
{"interface_stop", {1, 1, {false, do_interface_stop}}},
{"load_persist_props", {0, 0, {false, do_load_persist_props}}},
{"load_system_props", {0, 0, {false, do_load_system_props}}},
{"loglevel", {1, 1, {false, do_loglevel}}},
{"mkdir", {1, 4, {true, do_mkdir}}},
// TODO: Do mount operations in vendor_init.
// mount_all is currently too complex to run in vendor_init as it queues action triggers,
// imports rc scripts, etc. It should be simplified and run in vendor_init context.
// mount and umount are run in the same context as mount_all for symmetry.
{"mount_all", {1, kMax, {false, do_mount_all}}},
{"mount", {3, kMax, {false, do_mount}}},
{"parse_apex_configs", {0, 0, {false, do_parse_apex_configs}}},
{"prepare_bootstrap_bionic",{0, 0, {false, do_prepare_bootstrap_bionic}}},
{"umount", {1, 1, {false, do_umount}}},
{"readahead", {1, 2, {true, do_readahead}}},
{"restart", {1, 1, {false, do_restart}}},
{"restorecon", {1, kMax, {true, do_restorecon}}},
{"restorecon_recursive", {1, kMax, {true, do_restorecon_recursive}}},
{"rm", {1, 1, {true, do_rm}}},
{"rmdir", {1, 1, {true, do_rmdir}}},
{"setprop", {2, 2, {true, do_setprop}}},
{"setup_runtime_bionic", {0, 0, {false, do_setup_runtime_bionic}}},
{"setrlimit", {3, 3, {false, do_setrlimit}}},
{"start", {1, 1, {false, do_start}}},
{"stop", {1, 1, {false, do_stop}}},
{"swapon_all", {1, 1, {false, do_swapon_all}}},
{"symlink", {2, 2, {true, do_symlink}}},
{"sysclktz", {1, 1, {false, do_sysclktz}}},
{"trigger", {1, 1, {false, do_trigger}}},
{"verity_load_state", {0, 0, {false, do_verity_load_state}}},
{"verity_update_state", {0, 0, {false, do_verity_update_state}}},
{"wait", {1, 2, {true, do_wait}}},
{"wait_for_prop", {2, 2, {false, do_wait_for_prop}}},
{"write", {2, 2, {true, do_write}}},
};
// clang-format on
return builtin_functions;
}
// Builtin-function-map end
} // namespace init
} // namespace android
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