/* * 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 <sys/wait.h> #include <termios.h> #include <unistd.h> #include <selinux/selinux.h> #include <android-base/file.h> #include <android-base/stringprintf.h> #include <cutils/android_reboot.h> #include <cutils/sockets.h> #include "action.h" #include "init.h" #include "init_parser.h" #include "log.h" #include "property_service.h" #include "util.h" using android::base::StringPrintf; using android::base::WriteStringToFile; #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 ((flags_ & SVC_EXEC) != 0) { // 'exec' commands don't have properties tracking their state. return; } std::string prop_name = 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 = 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::HandleClass(const std::vector<std::string>& args, std::string* err) { classname_ = args[1]; return true; } bool Service::HandleConsole(const std::vector<std::string>& args, std::string* err) { flags_ |= SVC_CONSOLE; return true; } bool Service::HandleCritical(const std::vector<std::string>& args, std::string* err) { flags_ |= SVC_CRITICAL; return true; } bool Service::HandleDisabled(const std::vector<std::string>& args, std::string* err) { flags_ |= SVC_DISABLED; flags_ |= SVC_RC_DISABLED; return true; } bool Service::HandleGroup(const std::vector<std::string>& args, std::string* err) { gid_ = decode_uid(args[1].c_str()); for (std::size_t n = 2; n < args.size(); n++) { supp_gids_.emplace_back(decode_uid(args[n].c_str())); } return true; } bool Service::HandleIoprio(const std::vector<std::string>& args, std::string* err) { ioprio_pri_ = std::stoul(args[2], 0, 8); if (ioprio_pri_ < 0 || ioprio_pri_ > 7) { *err = "priority value must be range 0 - 7"; 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>"; return false; } return true; } bool Service::HandleKeycodes(const std::vector<std::string>& args, std::string* err) { for (std::size_t i = 1; i < args.size(); i++) { keycodes_.emplace_back(std::stoi(args[i])); } return true; } bool Service::HandleOneshot(const std::vector<std::string>& args, std::string* err) { flags_ |= SVC_ONESHOT; return true; } bool Service::HandleOnrestart(const std::vector<std::string>& args, std::string* err) { std::vector<std::string> str_args(args.begin() + 1, args.end()); onrestart_.AddCommand(str_args, "", 0, err); return true; } bool Service::HandleSeclabel(const std::vector<std::string>& args, std::string* err) { seclabel_ = args[1]; return true; } bool Service::HandleSetenv(const std::vector<std::string>& args, std::string* err) { envvars_.emplace_back(args[1], args[2]); return true; } /* name type perm [ uid gid context ] */ bool Service::HandleSocket(const std::vector<std::string>& args, std::string* err) { if (args[2] != "dgram" && args[2] != "stream" && args[2] != "seqpacket") { *err = "socket type must be 'dgram', 'stream' or 'seqpacket'"; 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_.emplace_back(args[1], args[2], uid, gid, perm, socketcon); return true; } bool Service::HandleUser(const std::vector<std::string>& args, std::string* err) { uid_ = decode_uid(args[1].c_str()); return true; } bool Service::HandleWritepid(const std::vector<std::string>& args, std::string* err) { writepid_files_.assign(args.begin() + 1, args.end()); return true; } class Service::OptionHandlerMap : public KeywordMap<OptionHandler> { public: OptionHandlerMap() { } private: Map& map() const override; }; Service::OptionHandlerMap::Map& Service::OptionHandlerMap::map() const { constexpr std::size_t kMax = std::numeric_limits<std::size_t>::max(); static const Map option_handlers = { {"class", {1, 1, &Service::HandleClass}}, {"console", {0, 0, &Service::HandleConsole}}, {"critical", {0, 0, &Service::HandleCritical}}, {"disabled", {0, 0, &Service::HandleDisabled}}, {"group", {1, NR_SVC_SUPP_GIDS + 1, &Service::HandleGroup}}, {"ioprio", {2, 2, &Service::HandleIoprio}}, {"keycodes", {1, kMax, &Service::HandleKeycodes}}, {"oneshot", {0, 0, &Service::HandleOneshot}}, {"onrestart", {1, kMax, &Service::HandleOnrestart}}, {"seclabel", {1, 1, &Service::HandleSeclabel}}, {"setenv", {2, 2, &Service::HandleSetenv}}, {"socket", {3, 6, &Service::HandleSocket}}, {"user", {1, 1, &Service::HandleUser}}, {"writepid", {1, kMax, &Service::HandleWritepid}}, }; return option_handlers; } bool Service::HandleLine(const std::vector<std::string>& args, std::string* err) { if (args.empty()) { *err = "option needed, but not provided"; return false; } static const OptionHandlerMap handler_map; auto handler = handler_map.FindFunction(args[0], args.size() - 1, err); if (!handler) { return false; } return (this->*handler)(args, err); } bool Service::Start() { // 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; } 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) { umask(077); 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 = StringPrintf("%d", getpid()); for (const auto& file : writepid_files_) { if (!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())); } 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::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::Terminate() { flags_ &= ~(SVC_RESTARTING | SVC_DISABLED_START); flags_ |= SVC_DISABLED; if (pid_) { NOTICE("Sending SIGTERM to service '%s' (pid %d)...\n", name_.c_str(), pid_); kill(-pid_, SIGTERM); NotifyStateChange("stopping"); } } 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 = StringPrintf(ANDROID_SOCKET_ENV_PREFIX "%s", name.c_str()); std::string val = 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; } void ServiceManager::AddService(std::unique_ptr<Service> service) { Service* old_service = FindServiceByName(service->name()); if (old_service) { ERROR("ignored duplicate definition of service '%s'", service->name().c_str()); return; } services_.emplace_back(std::move(service)); } 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 = 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(std::function<void(Service*)> callback) const { for (const auto& s : services_) { callback(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); } void ServiceManager::DumpState() const { for (const auto& s : services_) { s->DumpState(); } INFO("\n"); } bool ServiceManager::ReapOneProcess() { int status; pid_t pid = TEMP_FAILURE_RETRY(waitpid(-1, &status, WNOHANG)); if (pid == 0) { return false; } else if (pid == -1) { ERROR("waitpid failed: %s\n", strerror(errno)); return false; } Service* svc = FindServiceByPid(pid); std::string name; if (svc) { name = android::base::StringPrintf("Service '%s' (pid %d)", svc->name().c_str(), pid); } else { name = android::base::StringPrintf("Untracked pid %d", pid); } if (WIFEXITED(status)) { NOTICE("%s exited with status %d\n", name.c_str(), WEXITSTATUS(status)); } else if (WIFSIGNALED(status)) { NOTICE("%s killed by signal %d\n", name.c_str(), WTERMSIG(status)); } else if (WIFSTOPPED(status)) { NOTICE("%s stopped by signal %d\n", name.c_str(), WSTOPSIG(status)); } else { NOTICE("%s state changed", name.c_str()); } if (!svc) { return true; } if (svc->Reap()) { waiting_for_exec = false; RemoveService(*svc); } return true; } void ServiceManager::ReapAnyOutstandingChildren() { while (ReapOneProcess()) { } } bool ServiceParser::ParseSection(const std::vector<std::string>& args, std::string* err) { if (args.size() < 3) { *err = "services must have a name and a program"; return false; } const std::string& name = args[1]; if (!IsValidName(name)) { *err = StringPrintf("invalid service name '%s'", name.c_str()); return false; } std::vector<std::string> str_args(args.begin() + 2, args.end()); service_ = std::make_unique<Service>(name, "default", str_args); return true; } bool ServiceParser::ParseLineSection(const std::vector<std::string>& args, const std::string& filename, int line, std::string* err) const { return service_ ? service_->HandleLine(args, err) : false; } void ServiceParser::EndSection() { if (service_) { ServiceManager::GetInstance().AddService(std::move(service_)); } } bool ServiceParser::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; }