platform_system_core/init/service.cpp

806 lines
25 KiB
C++

/*
* Copyright (C) 2015 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 "service.h"
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <termios.h>
#include <unistd.h>
#include <selinux/selinux.h>
#include <base/file.h>
#include <base/stringprintf.h>
#include <cutils/android_reboot.h>
#include <cutils/sockets.h>
#include "action.h"
#include "init.h"
#include "init_parser.h"
#include "keywords.h"
#include "log.h"
#include "property_service.h"
#include "util.h"
#define CRITICAL_CRASH_THRESHOLD 4 // if we crash >4 times ...
#define CRITICAL_CRASH_WINDOW (4*60) // ... in 4 minutes, goto recovery
SocketInfo::SocketInfo() : uid(0), gid(0), perm(0) {
}
SocketInfo::SocketInfo(const std::string& name, const std::string& type, uid_t uid,
gid_t gid, int perm, const std::string& socketcon)
: name(name), type(type), uid(uid), gid(gid), perm(perm), socketcon(socketcon) {
}
ServiceEnvironmentInfo::ServiceEnvironmentInfo() {
}
ServiceEnvironmentInfo::ServiceEnvironmentInfo(const std::string& name,
const std::string& value)
: name(name), value(value) {
}
Service::Service(const std::string& name, const std::string& classname,
const std::vector<std::string>& args)
: name_(name), classname_(classname), flags_(0), pid_(0), time_started_(0),
time_crashed_(0), nr_crashed_(0), uid_(0), gid_(0), seclabel_(""),
ioprio_class_(IoSchedClass_NONE), ioprio_pri_(0), args_(args) {
onrestart_.InitSingleTrigger("onrestart");
}
Service::Service(const std::string& name, const std::string& classname,
unsigned flags, uid_t uid, gid_t gid, const std::vector<gid_t>& supp_gids,
const std::string& seclabel, const std::vector<std::string>& args)
: name_(name), classname_(classname), flags_(flags), pid_(0), time_started_(0),
time_crashed_(0), nr_crashed_(0), uid_(uid), gid_(gid), supp_gids_(supp_gids),
seclabel_(seclabel), ioprio_class_(IoSchedClass_NONE), ioprio_pri_(0), args_(args) {
onrestart_.InitSingleTrigger("onrestart");
}
void Service::NotifyStateChange(const std::string& new_state) const {
if (!properties_initialized()) {
// If properties aren't available yet, we can't set them.
return;
}
if ((flags_ & SVC_EXEC) != 0) {
// 'exec' commands don't have properties tracking their state.
return;
}
std::string prop_name = android::base::StringPrintf("init.svc.%s", name_.c_str());
if (prop_name.length() >= PROP_NAME_MAX) {
// If the property name would be too long, we can't set it.
ERROR("Property name \"init.svc.%s\" too long; not setting to %s\n",
name_.c_str(), new_state.c_str());
return;
}
property_set(prop_name.c_str(), new_state.c_str());
}
bool Service::Reap() {
if (!(flags_ & SVC_ONESHOT) || (flags_ & SVC_RESTART)) {
NOTICE("Service '%s' (pid %d) killing any children in process group\n",
name_.c_str(), pid_);
kill(-pid_, SIGKILL);
}
// Remove any sockets we may have created.
for (const auto& si : sockets_) {
std::string tmp = android::base::StringPrintf(ANDROID_SOCKET_DIR "/%s",
si.name.c_str());
unlink(tmp.c_str());
}
if (flags_ & SVC_EXEC) {
INFO("SVC_EXEC pid %d finished...\n", pid_);
return true;
}
pid_ = 0;
flags_ &= (~SVC_RUNNING);
// Oneshot processes go into the disabled state on exit,
// except when manually restarted.
if ((flags_ & SVC_ONESHOT) && !(flags_ & SVC_RESTART)) {
flags_ |= SVC_DISABLED;
}
// Disabled and reset processes do not get restarted automatically.
if (flags_ & (SVC_DISABLED | SVC_RESET)) {
NotifyStateChange("stopped");
return false;
}
time_t now = gettime();
if ((flags_ & SVC_CRITICAL) && !(flags_ & SVC_RESTART)) {
if (time_crashed_ + CRITICAL_CRASH_WINDOW >= now) {
if (++nr_crashed_ > CRITICAL_CRASH_THRESHOLD) {
ERROR("critical process '%s' exited %d times in %d minutes; "
"rebooting into recovery mode\n", name_.c_str(),
CRITICAL_CRASH_THRESHOLD, CRITICAL_CRASH_WINDOW / 60);
android_reboot(ANDROID_RB_RESTART2, 0, "recovery");
return false;
}
} else {
time_crashed_ = now;
nr_crashed_ = 1;
}
}
flags_ &= (~SVC_RESTART);
flags_ |= SVC_RESTARTING;
// Execute all onrestart commands for this service.
onrestart_.ExecuteAllCommands();
NotifyStateChange("restarting");
return false;
}
void Service::DumpState() const {
INFO("service %s\n", name_.c_str());
INFO(" class '%s'\n", classname_.c_str());
INFO(" exec");
for (const auto& s : args_) {
INFO(" '%s'", s.c_str());
}
INFO("\n");
for (const auto& si : sockets_) {
INFO(" socket %s %s 0%o\n", si.name.c_str(), si.type.c_str(), si.perm);
}
}
bool Service::HandleLine(int kw, const std::vector<std::string>& args, std::string* err) {
std::vector<std::string> str_args;
ioprio_class_ = IoSchedClass_NONE;
switch (kw) {
case K_class:
if (args.size() != 2) {
*err = "class option requires a classname\n";
return false;
} else {
classname_ = args[1];
}
break;
case K_console:
flags_ |= SVC_CONSOLE;
break;
case K_disabled:
flags_ |= SVC_DISABLED;
flags_ |= SVC_RC_DISABLED;
break;
case K_ioprio:
if (args.size() != 3) {
*err = "ioprio optin usage: ioprio <rt|be|idle> <ioprio 0-7>\n";
return false;
} else {
ioprio_pri_ = std::stoul(args[2], 0, 8);
if (ioprio_pri_ < 0 || ioprio_pri_ > 7) {
*err = "priority value must be range 0 - 7\n";
return false;
}
if (args[1] == "rt") {
ioprio_class_ = IoSchedClass_RT;
} else if (args[1] == "be") {
ioprio_class_ = IoSchedClass_BE;
} else if (args[1] == "idle") {
ioprio_class_ = IoSchedClass_IDLE;
} else {
*err = "ioprio option usage: ioprio <rt|be|idle> <0-7>\n";
return false;
}
}
break;
case K_group:
if (args.size() < 2) {
*err = "group option requires a group id\n";
return false;
} else if (args.size() > NR_SVC_SUPP_GIDS + 2) {
*err = android::base::StringPrintf("group option accepts at most %d supp. groups\n",
NR_SVC_SUPP_GIDS);
return false;
} else {
gid_ = decode_uid(args[1].c_str());
for (std::size_t n = 2; n < args.size(); n++) {
supp_gids_.push_back(decode_uid(args[n].c_str()));
}
}
break;
case K_keycodes:
if (args.size() < 2) {
*err = "keycodes option requires atleast one keycode\n";
return false;
} else {
for (std::size_t i = 1; i < args.size(); i++) {
keycodes_.push_back(std::stoi(args[i]));
}
}
break;
case K_oneshot:
flags_ |= SVC_ONESHOT;
break;
case K_onrestart:
if (args.size() < 2) {
return false;
}
str_args.assign(args.begin() + 1, args.end());
add_command_to_action(&onrestart_, str_args, "", 0, err);
break;
case K_critical:
flags_ |= SVC_CRITICAL;
break;
case K_setenv: { /* name value */
if (args.size() < 3) {
*err = "setenv option requires name and value arguments\n";
return false;
}
envvars_.push_back({args[1], args[2]});
break;
}
case K_socket: {/* name type perm [ uid gid context ] */
if (args.size() < 4) {
*err = "socket option requires name, type, perm arguments\n";
return false;
}
if (args[2] != "dgram" && args[2] != "stream" &&
args[2] != "seqpacket") {
*err = "socket type must be 'dgram', 'stream' or 'seqpacket'\n";
return false;
}
int perm = std::stoul(args[3], 0, 8);
uid_t uid = args.size() > 4 ? decode_uid(args[4].c_str()) : 0;
gid_t gid = args.size() > 5 ? decode_uid(args[5].c_str()) : 0;
std::string socketcon = args.size() > 6 ? args[6] : "";
sockets_.push_back({args[1], args[2], uid, gid, perm, socketcon});
break;
}
case K_user:
if (args.size() != 2) {
*err = "user option requires a user id\n";
return false;
} else {
uid_ = decode_uid(args[1].c_str());
}
break;
case K_seclabel:
if (args.size() != 2) {
*err = "seclabel option requires a label string\n";
return false;
} else {
seclabel_ = args[1];
}
break;
case K_writepid:
if (args.size() < 2) {
*err = "writepid option requires at least one filename\n";
return false;
}
writepid_files_.assign(args.begin() + 1, args.end());
break;
default:
*err = android::base::StringPrintf("invalid option '%s'\n", args[0].c_str());
return false;
}
return true;
}
bool Service::Start(const std::vector<std::string>& dynamic_args) {
// Starting a service removes it from the disabled or reset state and
// immediately takes it out of the restarting state if it was in there.
flags_ &= (~(SVC_DISABLED|SVC_RESTARTING|SVC_RESET|SVC_RESTART|SVC_DISABLED_START));
time_started_ = 0;
// Running processes require no additional work --- if they're in the
// process of exiting, we've ensured that they will immediately restart
// on exit, unless they are ONESHOT.
if (flags_ & SVC_RUNNING) {
return false;
}
bool needs_console = (flags_ & SVC_CONSOLE);
if (needs_console && !have_console) {
ERROR("service '%s' requires console\n", name_.c_str());
flags_ |= SVC_DISABLED;
return false;
}
struct stat sb;
if (stat(args_[0].c_str(), &sb) == -1) {
ERROR("cannot find '%s' (%s), disabling '%s'\n",
args_[0].c_str(), strerror(errno), name_.c_str());
flags_ |= SVC_DISABLED;
return false;
}
if ((!(flags_ & SVC_ONESHOT)) && !dynamic_args.empty()) {
ERROR("service '%s' must be one-shot to use dynamic args, disabling\n",
args_[0].c_str());
flags_ |= SVC_DISABLED;
return false;
}
std::string scon;
if (!seclabel_.empty()) {
scon = seclabel_;
} else {
char* mycon = nullptr;
char* fcon = nullptr;
INFO("computing context for service '%s'\n", args_[0].c_str());
int rc = getcon(&mycon);
if (rc < 0) {
ERROR("could not get context while starting '%s'\n", name_.c_str());
return false;
}
rc = getfilecon(args_[0].c_str(), &fcon);
if (rc < 0) {
ERROR("could not get context while starting '%s'\n", name_.c_str());
free(mycon);
return false;
}
char* ret_scon = nullptr;
rc = security_compute_create(mycon, fcon, string_to_security_class("process"),
&ret_scon);
if (rc == 0) {
scon = ret_scon;
free(ret_scon);
}
if (rc == 0 && scon == mycon) {
ERROR("Service %s does not have a SELinux domain defined.\n", name_.c_str());
free(mycon);
free(fcon);
return false;
}
free(mycon);
free(fcon);
if (rc < 0) {
ERROR("could not get context while starting '%s'\n", name_.c_str());
return false;
}
}
NOTICE("Starting service '%s'...\n", name_.c_str());
pid_t pid = fork();
if (pid == 0) {
int fd, sz;
umask(077);
if (properties_initialized()) {
get_property_workspace(&fd, &sz);
std::string tmp = android::base::StringPrintf("%d,%d", dup(fd), sz);
add_environment("ANDROID_PROPERTY_WORKSPACE", tmp.c_str());
}
for (const auto& ei : envvars_) {
add_environment(ei.name.c_str(), ei.value.c_str());
}
for (const auto& si : sockets_) {
int socket_type = ((si.type == "stream" ? SOCK_STREAM :
(si.type == "dgram" ? SOCK_DGRAM :
SOCK_SEQPACKET)));
const char* socketcon =
!si.socketcon.empty() ? si.socketcon.c_str() : scon.c_str();
int s = create_socket(si.name.c_str(), socket_type, si.perm,
si.uid, si.gid, socketcon);
if (s >= 0) {
PublishSocket(si.name, s);
}
}
std::string pid_str = android::base::StringPrintf("%d", pid);
for (const auto& file : writepid_files_) {
if (!android::base::WriteStringToFile(pid_str, file)) {
ERROR("couldn't write %s to %s: %s\n",
pid_str.c_str(), file.c_str(), strerror(errno));
}
}
if (ioprio_class_ != IoSchedClass_NONE) {
if (android_set_ioprio(getpid(), ioprio_class_, ioprio_pri_)) {
ERROR("Failed to set pid %d ioprio = %d,%d: %s\n",
getpid(), ioprio_class_, ioprio_pri_, strerror(errno));
}
}
if (needs_console) {
setsid();
OpenConsole();
} else {
ZapStdio();
}
setpgid(0, getpid());
// As requested, set our gid, supplemental gids, and uid.
if (gid_) {
if (setgid(gid_) != 0) {
ERROR("setgid failed: %s\n", strerror(errno));
_exit(127);
}
}
if (!supp_gids_.empty()) {
if (setgroups(supp_gids_.size(), &supp_gids_[0]) != 0) {
ERROR("setgroups failed: %s\n", strerror(errno));
_exit(127);
}
}
if (uid_) {
if (setuid(uid_) != 0) {
ERROR("setuid failed: %s\n", strerror(errno));
_exit(127);
}
}
if (!seclabel_.empty()) {
if (setexeccon(seclabel_.c_str()) < 0) {
ERROR("cannot setexeccon('%s'): %s\n",
seclabel_.c_str(), strerror(errno));
_exit(127);
}
}
std::vector<char*> strs;
for (const auto& s : args_) {
strs.push_back(const_cast<char*>(s.c_str()));
}
for (const auto& s : dynamic_args) {
strs.push_back(const_cast<char*>(s.c_str()));
}
strs.push_back(nullptr);
if (execve(args_[0].c_str(), (char**) &strs[0], (char**) ENV) < 0) {
ERROR("cannot execve('%s'): %s\n", args_[0].c_str(), strerror(errno));
}
_exit(127);
}
if (pid < 0) {
ERROR("failed to start '%s'\n", name_.c_str());
pid_ = 0;
return false;
}
time_started_ = gettime();
pid_ = pid;
flags_ |= SVC_RUNNING;
if ((flags_ & SVC_EXEC) != 0) {
INFO("SVC_EXEC pid %d (uid %d gid %d+%zu context %s) started; waiting...\n",
pid_, uid_, gid_, supp_gids_.size(),
!seclabel_.empty() ? seclabel_.c_str() : "default");
}
NotifyStateChange("running");
return true;
}
bool Service::Start() {
const std::vector<std::string> null_dynamic_args;
return Start(null_dynamic_args);
}
bool Service::StartIfNotDisabled() {
if (!(flags_ & SVC_DISABLED)) {
return Start();
} else {
flags_ |= SVC_DISABLED_START;
}
return true;
}
bool Service::Enable() {
flags_ &= ~(SVC_DISABLED | SVC_RC_DISABLED);
if (flags_ & SVC_DISABLED_START) {
return Start();
}
return true;
}
void Service::Reset() {
StopOrReset(SVC_RESET);
}
void Service::Stop() {
StopOrReset(SVC_DISABLED);
}
void Service::Restart() {
if (flags_ & SVC_RUNNING) {
/* Stop, wait, then start the service. */
StopOrReset(SVC_RESTART);
} else if (!(flags_ & SVC_RESTARTING)) {
/* Just start the service since it's not running. */
Start();
} /* else: Service is restarting anyways. */
}
void Service::RestartIfNeeded(time_t& process_needs_restart) {
time_t next_start_time = time_started_ + 5;
if (next_start_time <= gettime()) {
flags_ &= (~SVC_RESTARTING);
Start();
return;
}
if ((next_start_time < process_needs_restart) ||
(process_needs_restart == 0)) {
process_needs_restart = next_start_time;
}
}
/* The how field should be either SVC_DISABLED, SVC_RESET, or SVC_RESTART */
void Service::StopOrReset(int how) {
/* The service is still SVC_RUNNING until its process exits, but if it has
* already exited it shoudn't attempt a restart yet. */
flags_ &= ~(SVC_RESTARTING | SVC_DISABLED_START);
if ((how != SVC_DISABLED) && (how != SVC_RESET) && (how != SVC_RESTART)) {
/* Hrm, an illegal flag. Default to SVC_DISABLED */
how = SVC_DISABLED;
}
/* if the service has not yet started, prevent
* it from auto-starting with its class
*/
if (how == SVC_RESET) {
flags_ |= (flags_ & SVC_RC_DISABLED) ? SVC_DISABLED : SVC_RESET;
} else {
flags_ |= how;
}
if (pid_) {
NOTICE("Service '%s' is being killed...\n", name_.c_str());
kill(-pid_, SIGKILL);
NotifyStateChange("stopping");
} else {
NotifyStateChange("stopped");
}
}
void Service::ZapStdio() const {
int fd;
fd = open("/dev/null", O_RDWR);
dup2(fd, 0);
dup2(fd, 1);
dup2(fd, 2);
close(fd);
}
void Service::OpenConsole() const {
int fd;
if ((fd = open(console_name.c_str(), O_RDWR)) < 0) {
fd = open("/dev/null", O_RDWR);
}
ioctl(fd, TIOCSCTTY, 0);
dup2(fd, 0);
dup2(fd, 1);
dup2(fd, 2);
close(fd);
}
void Service::PublishSocket(const std::string& name, int fd) const {
std::string key = android::base::StringPrintf(ANDROID_SOCKET_ENV_PREFIX "%s",
name.c_str());
std::string val = android::base::StringPrintf("%d", fd);
add_environment(key.c_str(), val.c_str());
/* make sure we don't close-on-exec */
fcntl(fd, F_SETFD, 0);
}
int ServiceManager::exec_count_ = 0;
ServiceManager::ServiceManager() {
}
ServiceManager& ServiceManager::GetInstance() {
static ServiceManager instance;
return instance;
}
Service* ServiceManager::AddNewService(const std::string& name,
const std::string& classname,
const std::vector<std::string>& args,
std::string* err) {
if (!IsValidName(name)) {
*err = android::base::StringPrintf("invalid service name '%s'\n", name.c_str());
return nullptr;
}
Service* svc = ServiceManager::GetInstance().FindServiceByName(name);
if (svc) {
*err = android::base::StringPrintf("ignored duplicate definition of service '%s'\n",
name.c_str());
return nullptr;
}
std::unique_ptr<Service> svc_p(new Service(name, classname, args));
if (!svc_p) {
ERROR("Couldn't allocate service for service '%s'", name.c_str());
return nullptr;
}
svc = svc_p.get();
services_.push_back(std::move(svc_p));
return svc;
}
Service* ServiceManager::MakeExecOneshotService(const std::vector<std::string>& args) {
// Parse the arguments: exec [SECLABEL [UID [GID]*] --] COMMAND ARGS...
// SECLABEL can be a - to denote default
std::size_t command_arg = 1;
for (std::size_t i = 1; i < args.size(); ++i) {
if (args[i] == "--") {
command_arg = i + 1;
break;
}
}
if (command_arg > 4 + NR_SVC_SUPP_GIDS) {
ERROR("exec called with too many supplementary group ids\n");
return nullptr;
}
if (command_arg >= args.size()) {
ERROR("exec called without command\n");
return nullptr;
}
std::vector<std::string> str_args(args.begin() + command_arg, args.end());
exec_count_++;
std::string name = android::base::StringPrintf("exec %d (%s)", exec_count_,
str_args[0].c_str());
unsigned flags = SVC_EXEC | SVC_ONESHOT;
std::string seclabel = "";
if (command_arg > 2 && args[1] != "-") {
seclabel = args[1];
}
uid_t uid = 0;
if (command_arg > 3) {
uid = decode_uid(args[2].c_str());
}
gid_t gid = 0;
std::vector<gid_t> supp_gids;
if (command_arg > 4) {
gid = decode_uid(args[3].c_str());
std::size_t nr_supp_gids = command_arg - 1 /* -- */ - 4 /* exec SECLABEL UID GID */;
for (size_t i = 0; i < nr_supp_gids; ++i) {
supp_gids.push_back(decode_uid(args[4 + i].c_str()));
}
}
std::unique_ptr<Service> svc_p(new Service(name, "default", flags, uid, gid,
supp_gids, seclabel, str_args));
if (!svc_p) {
ERROR("Couldn't allocate service for exec of '%s'",
str_args[0].c_str());
return nullptr;
}
Service* svc = svc_p.get();
services_.push_back(std::move(svc_p));
return svc;
}
Service* ServiceManager::FindServiceByName(const std::string& name) const {
auto svc = std::find_if(services_.begin(), services_.end(),
[&name] (const std::unique_ptr<Service>& s) {
return name == s->name();
});
if (svc != services_.end()) {
return svc->get();
}
return nullptr;
}
Service* ServiceManager::FindServiceByPid(pid_t pid) const {
auto svc = std::find_if(services_.begin(), services_.end(),
[&pid] (const std::unique_ptr<Service>& s) {
return s->pid() == pid;
});
if (svc != services_.end()) {
return svc->get();
}
return nullptr;
}
Service* ServiceManager::FindServiceByKeychord(int keychord_id) const {
auto svc = std::find_if(services_.begin(), services_.end(),
[&keychord_id] (const std::unique_ptr<Service>& s) {
return s->keychord_id() == keychord_id;
});
if (svc != services_.end()) {
return svc->get();
}
return nullptr;
}
void ServiceManager::ForEachService(void (*func)(Service* svc)) const {
for (const auto& s : services_) {
func(s.get());
}
}
void ServiceManager::ForEachServiceInClass(const std::string& classname,
void (*func)(Service* svc)) const {
for (const auto& s : services_) {
if (classname == s->classname()) {
func(s.get());
}
}
}
void ServiceManager::ForEachServiceWithFlags(unsigned matchflags,
void (*func)(Service* svc)) const {
for (const auto& s : services_) {
if (s->flags() & matchflags) {
func(s.get());
}
}
}
void ServiceManager::RemoveService(const Service& svc)
{
auto svc_it = std::find_if(services_.begin(), services_.end(),
[&svc] (const std::unique_ptr<Service>& s) {
return svc.name() == s->name();
});
if (svc_it == services_.end()) {
return;
}
services_.erase(svc_it);
}
bool ServiceManager::IsValidName(const std::string& name) const
{
if (name.size() > 16) {
return false;
}
for (const auto& c : name) {
if (!isalnum(c) && (c != '_') && (c != '-')) {
return false;
}
}
return true;
}
void ServiceManager::DumpState() const
{
for (const auto& s : services_) {
s->DumpState();
}
INFO("\n");
}