1 /*
2  * Copyright (C) 2015 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #pragma once
18 
19 #include <signal.h>
20 #include <sys/types.h>
21 
22 #include <algorithm>
23 #include <chrono>
24 #include <memory>
25 #include <optional>
26 #include <set>
27 #include <string>
28 #include <vector>
29 
30 #include <android-base/chrono_utils.h>
31 #include <cutils/iosched_policy.h>
32 
33 #include "action.h"
34 #include "capabilities.h"
35 #include "interprocess_fifo.h"
36 #include "keyword_map.h"
37 #include "mount_namespace.h"
38 #include "parser.h"
39 #include "service_utils.h"
40 #include "subcontext.h"
41 
42 #define SVC_DISABLED 0x001        // do not autostart with class
43 #define SVC_ONESHOT 0x002         // do not restart on exit
44 #define SVC_RUNNING 0x004         // currently active
45 #define SVC_RESTARTING 0x008      // waiting to restart
46 #define SVC_CONSOLE 0x010         // requires console
47 #define SVC_CRITICAL 0x020        // will reboot into bootloader if keeps crashing
48 #define SVC_RESET 0x040           // Use when stopping a process,
49                                   // but not disabling so it can be restarted with its class.
50 #define SVC_RC_DISABLED 0x080     // Remember if the disabled flag was set in the rc script.
51 #define SVC_RESTART 0x100         // Use to safely restart (stop, wait, start) a service.
52 #define SVC_DISABLED_START 0x200  // A start was requested but it was disabled at the time.
53 #define SVC_EXEC 0x400  // This service was started by either 'exec' or 'exec_start' and stops
54                         // init from processing more commands until it completes
55 
56 #define SVC_SHUTDOWN_CRITICAL 0x800  // This service is critical for shutdown and
57                                      // should not be killed during shutdown
58 #define SVC_TEMPORARY 0x1000  // This service was started by 'exec' and should be removed from the
59                               // service list once it is reaped.
60 #define SVC_GENTLE_KILL 0x2000  // This service should be stopped with SIGTERM instead of SIGKILL
61                                 // Will still be SIGKILLed after timeout period of 200 ms
62 
63 #define NR_SVC_SUPP_GIDS 32    // thirty two supplementary groups
64 
65 namespace android {
66 namespace init {
67 
68 class Service {
69     friend class ServiceParser;
70 
71   public:
72     Service(const std::string& name, Subcontext* subcontext_for_restart_commands,
73             const std::string& filename, const std::vector<std::string>& args);
74 
75     Service(const std::string& name, unsigned flags, std::optional<uid_t> uid, gid_t gid,
76             const std::vector<gid_t>& supp_gids, int namespace_flags, const std::string& seclabel,
77             Subcontext* subcontext_for_restart_commands, const std::string& filename,
78             const std::vector<std::string>& args);
79     Service(const Service&) = delete;
80     void operator=(const Service&) = delete;
81 
82     static Result<std::unique_ptr<Service>> MakeTemporaryOneshotService(
83             const std::vector<std::string>& args);
84 
IsRunning()85     bool IsRunning() { return (flags_ & SVC_RUNNING) != 0; }
IsEnabled()86     bool IsEnabled() { return (flags_ & SVC_DISABLED) == 0; }
87     Result<void> ExecStart();
88     Result<void> Start();
89     Result<void> StartIfNotDisabled();
90     Result<void> Enable();
91     void Reset();
92     void Stop();
93     void Terminate();
94     void Timeout();
95     void Restart();
96     void Reap(const siginfo_t& siginfo);
97     void DumpState() const;
SetShutdownCritical()98     void SetShutdownCritical() { flags_ |= SVC_SHUTDOWN_CRITICAL; }
IsShutdownCritical()99     bool IsShutdownCritical() const { return (flags_ & SVC_SHUTDOWN_CRITICAL) != 0; }
UnSetExec()100     void UnSetExec() {
101         is_exec_service_running_ = false;
102         flags_ &= ~SVC_EXEC;
103     }
AddReapCallback(std::function<void (const siginfo_t & siginfo)> callback)104     void AddReapCallback(std::function<void(const siginfo_t& siginfo)> callback) {
105         reap_callbacks_.emplace_back(std::move(callback));
106     }
107     void SetStartedInFirstStage(pid_t pid);
108     bool MarkSocketPersistent(const std::string& socket_name);
CheckAllCommands()109     size_t CheckAllCommands() const { return onrestart_.CheckAllCommands(); }
110 
is_exec_service_running()111     static bool is_exec_service_running() { return is_exec_service_running_; }
112 
name()113     const std::string& name() const { return name_; }
classnames()114     const std::set<std::string>& classnames() const { return classnames_; }
flags()115     unsigned flags() const { return flags_; }
pid()116     pid_t pid() const { return pid_; }
time_started()117     android::base::boot_clock::time_point time_started() const { return time_started_; }
crash_count()118     int crash_count() const { return crash_count_; }
was_last_exit_ok()119     int was_last_exit_ok() const { return was_last_exit_ok_; }
uid()120     uid_t uid() const { return proc_attr_.uid(); }
gid()121     gid_t gid() const { return proc_attr_.gid; }
namespace_flags()122     int namespace_flags() const { return namespaces_.flags; }
supp_gids()123     const std::vector<gid_t>& supp_gids() const { return proc_attr_.supp_gids; }
seclabel()124     const std::string& seclabel() const { return seclabel_; }
keycodes()125     const std::vector<int>& keycodes() const { return keycodes_; }
ioprio_class()126     IoSchedClass ioprio_class() const { return proc_attr_.ioprio_class; }
ioprio_pri()127     int ioprio_pri() const { return proc_attr_.ioprio_pri; }
interfaces()128     const std::set<std::string>& interfaces() const { return interfaces_; }
priority()129     int priority() const { return proc_attr_.priority; }
oom_score_adjust()130     int oom_score_adjust() const { return oom_score_adjust_; }
is_override()131     bool is_override() const { return override_; }
process_cgroup_empty()132     bool process_cgroup_empty() const { return process_cgroup_empty_; }
start_order()133     unsigned long start_order() const { return start_order_; }
set_sigstop(bool value)134     void set_sigstop(bool value) { sigstop_ = value; }
restart_period()135     std::chrono::seconds restart_period() const {
136         // If the service exited abnormally or due to timeout, late limit the restart even if
137         // restart_period is set to a very short value.
138         // If not, i.e. restart after a deliberate and successful exit, respect the period.
139         if (!was_last_exit_ok_) {
140             return std::max(restart_period_, default_restart_period_);
141         }
142         return restart_period_;
143     }
timeout_period()144     std::optional<std::chrono::seconds> timeout_period() const { return timeout_period_; }
args()145     const std::vector<std::string>& args() const { return args_; }
is_updatable()146     bool is_updatable() const { return updatable_; }
is_post_data()147     bool is_post_data() const { return post_data_; }
is_from_apex()148     bool is_from_apex() const { return base::StartsWith(filename_, "/apex/"); }
set_oneshot(bool value)149     void set_oneshot(bool value) {
150         if (value) {
151             flags_ |= SVC_ONESHOT;
152         } else {
153             flags_ &= ~SVC_ONESHOT;
154         }
155     }
subcontext()156     const Subcontext* subcontext() const { return subcontext_; }
filename()157     const std::string& filename() const { return filename_; }
set_filename(const std::string & name)158     void set_filename(const std::string& name) { filename_ = name; }
GetSigchldFd()159     static int GetSigchldFd() {
160         static int sigchld_fd = CreateSigchldFd().release();
161         return sigchld_fd;
162     }
163 
164   private:
165     void NotifyStateChange(const std::string& new_state) const;
166     void StopOrReset(int how);
167     void KillProcessGroup(int signal);
168     void SetProcessAttributesAndCaps(InterprocessFifo setsid_finished);
169     void ResetFlagsForStart();
170     Result<void> CheckConsole();
171     void ConfigureMemcg();
172     void RunService(const std::vector<Descriptor>& descriptors, InterprocessFifo cgroups_activated,
173                     InterprocessFifo setsid_finished);
174     void SetMountNamespace();
175     static ::android::base::unique_fd CreateSigchldFd();
176 
177     static unsigned long next_start_order_;
178     static bool is_exec_service_running_;
179 
180     const std::string name_;
181     std::set<std::string> classnames_;
182 
183     unsigned flags_;
184     pid_t pid_;
185     android::base::boot_clock::time_point time_started_;  // time of last start
186     android::base::boot_clock::time_point time_crashed_;  // first crash within inspection window
187     int crash_count_;                     // number of times crashed within window
188     bool upgraded_mte_ = false;           // whether we upgraded async MTE -> sync MTE before
189     std::chrono::minutes fatal_crash_window_ = 4min;  // fatal() when more than 4 crashes in it
190     std::optional<std::string> fatal_reboot_target_;  // reboot target of fatal handler
191     bool was_last_exit_ok_ =
192             true;  // true if the service never exited, or exited with status code 0
193 
194     std::optional<CapSet> capabilities_;
195     ProcessAttributes proc_attr_;
196     NamespaceInfo namespaces_;
197 
198     std::string seclabel_;
199 
200     std::vector<SocketDescriptor> sockets_;
201     std::vector<FileDescriptor> files_;
202     std::vector<std::pair<std::string, std::string>> environment_vars_;
203     // Environment variables that only get applied to the next run.
204     std::vector<std::pair<std::string, std::string>> once_environment_vars_;
205 
206     const Subcontext* const subcontext_;
207     Action onrestart_;  // Commands to execute on restart.
208 
209     std::vector<std::string> writepid_files_;
210 
211     std::vector<std::string> task_profiles_;
212 
213     std::set<std::string> interfaces_;  // e.g. some.package.foo@1.0::IBaz/instance-name
214 
215     // keycodes for triggering this service via /dev/input/input*
216     std::vector<int> keycodes_;
217 
218     int oom_score_adjust_;
219 
220     int swappiness_ = -1;
221     int soft_limit_in_bytes_ = -1;
222 
223     int limit_in_bytes_ = -1;
224     int limit_percent_ = -1;
225     std::string limit_property_;
226 
227     bool process_cgroup_empty_ = false;
228 
229     bool override_ = false;
230 
231     unsigned long start_order_;
232 
233     bool sigstop_ = false;
234 
235     const std::chrono::seconds default_restart_period_ = 5s;
236     std::chrono::seconds restart_period_ = default_restart_period_;
237     std::optional<std::chrono::seconds> timeout_period_;
238 
239     bool updatable_ = false;
240 
241     const std::vector<std::string> args_;
242 
243     std::vector<std::function<void(const siginfo_t& siginfo)>> reap_callbacks_;
244 
245     std::optional<MountNamespace> mount_namespace_;
246 
247     bool post_data_ = false;
248 
249     std::optional<std::string> on_failure_reboot_target_;
250 
251     std::string filename_;
252 };
253 
254 }  // namespace init
255 }  // namespace android
256