systemd: add hardware watchdog support

This adds minimal hardware watchdog support to PID 1. The idea is that
PID 1 supervises and watchdogs system services, while the hardware
watchdog is used to supervise PID 1.

This adds two hardware watchdog configuration options, for the runtime
watchdog and for a shutdown watchdog. The former is active during normal
operation, the latter only at reboots to ensure that if a clean reboot
times out we reboot nonetheless.

If the runtime watchdog is enabled PID 1 will automatically wake up at
half the configured interval and write to the watchdog daemon.

By default we enable the shutdown watchdog, but leave the runtime
watchdog disabled in order not to break independent hardware watchdog
daemons people might be using.

This is only the most basic hookup. If necessary we can later on hook
up the watchdog ping more closely with services deemed crucial.

1 files changed, 13 insertions, 6 deletions

diff --git a/src/dbus-manager.c b/src/dbus-manager.c
index 6d272cb321..0a6e55d87d 100644
--- a/src/dbus-manager.c
+++ b/src/dbus-manager.c
@@ -240,7 +240,9 @@
         "  <property name=\"SwapAuto\" type=\"b\" access=\"read\"/>\n"  \
         "  <property name=\"DefaultControllers\" type=\"as\" access=\"read\"/>\n" \
         "  <property name=\"DefaultStandardOutput\" type=\"s\" access=\"read\"/>\n" \
-        "  <property name=\"DefaultStandardError\" type=\"s\" access=\"read\"/>\n"
+        "  <property name=\"DefaultStandardError\" type=\"s\" access=\"read\"/>\n" \
+        "  <property name=\"RuntimeWatchdogUSec\" type=\"s\" access=\"read\"/>\n" \
+        "  <property name=\"ShutdownWatchdogUSec\" type=\"s\" access=\"read\"/>\n"
 
 #ifdef HAVE_SYSV_COMPAT
 #define BUS_MANAGER_INTERFACE_PROPERTIES_SYSV                           \
@@ -491,7 +493,10 @@ static int bus_manager_send_unit_files_changed(Manager *m) {
         return r;
 }
 
-static const char systemd_property_string[] = PACKAGE_STRING "\0" DISTRIBUTION "\0" SYSTEMD_FEATURES;
+static const char systemd_property_string[] =
+        PACKAGE_STRING "\0"
+        DISTRIBUTION "\0"
+        SYSTEMD_FEATURES;
 
 static const BusProperty bus_systemd_properties[] = {
         { "Version",       bus_property_append_string,    "s",  0                                             },
@@ -502,7 +507,7 @@ static const BusProperty bus_systemd_properties[] = {
 
 static const BusProperty bus_manager_properties[] = {
         { "RunningAs",     bus_manager_append_running_as,          "s", offsetof(Manager, running_as)                  },
-        { "Tainted",       bus_manager_append_tainted,             "s", 0 },
+        { "Tainted",       bus_manager_append_tainted,             "s", 0                                              },
         { "InitRDTimestamp", bus_property_append_uint64,           "t", offsetof(Manager, initrd_timestamp.realtime)   },
         { "InitRDTimestampMonotonic", bus_property_append_uint64,  "t", offsetof(Manager, initrd_timestamp.monotonic)  },
         { "StartupTimestamp", bus_property_append_uint64,          "t", offsetof(Manager, startup_timestamp.realtime)  },
@@ -511,11 +516,11 @@ static const BusProperty bus_manager_properties[] = {
         { "FinishTimestampMonotonic", bus_property_append_uint64,  "t", offsetof(Manager, finish_timestamp.monotonic)  },
         { "LogLevel",      bus_manager_append_log_level,           "s", 0,                                             0, bus_manager_set_log_level },
         { "LogTarget",     bus_manager_append_log_target,          "s", 0,                                             0, bus_manager_set_log_target },
-        { "NNames",        bus_manager_append_n_names,             "u", 0 },
-        { "NJobs",         bus_manager_append_n_jobs,              "u", 0 },
+        { "NNames",        bus_manager_append_n_names,             "u", 0                                              },
+        { "NJobs",         bus_manager_append_n_jobs,              "u", 0                                              },
         { "NInstalledJobs",bus_property_append_uint32,             "u", offsetof(Manager, n_installed_jobs)            },
         { "NFailedJobs",   bus_property_append_uint32,             "u", offsetof(Manager, n_failed_jobs)               },
-        { "Progress",      bus_manager_append_progress,            "d", 0 },
+        { "Progress",      bus_manager_append_progress,            "d", 0                                              },
         { "Environment",   bus_property_append_strv,              "as", offsetof(Manager, environment),                true },
         { "ConfirmSpawn",  bus_property_append_bool,               "b", offsetof(Manager, confirm_spawn)               },
         { "ShowStatus",    bus_property_append_bool,               "b", offsetof(Manager, show_status)                 },
@@ -527,6 +532,8 @@ static const BusProperty bus_manager_properties[] = {
         { "DefaultControllers", bus_property_append_strv,         "as", offsetof(Manager, default_controllers),        true },
         { "DefaultStandardOutput", bus_manager_append_exec_output, "s", offsetof(Manager, default_std_output)          },
         { "DefaultStandardError",  bus_manager_append_exec_output, "s", offsetof(Manager, default_std_error)           },
+        { "RuntimeWatchdogUSec", bus_property_append_usec,         "t", offsetof(Manager, runtime_watchdog),           },
+        { "ShutdownWatchdogUSec", bus_property_append_usec,        "t", offsetof(Manager, shutdown_watchdog),          },
 #ifdef HAVE_SYSV_COMPAT
         { "SysVConsole",   bus_property_append_bool,               "b", offsetof(Manager, sysv_console)                },
         { "SysVInitPath",  bus_property_append_strv,              "as", offsetof(Manager, lookup_paths.sysvinit_path), true },