From be9fad86ae9ab721cd295210962da85706b839e9 Mon Sep 17 00:00:00 2001

From: =?UTF-8?q?Luk=C3=A1=C5=A1=20Nykr=C3=BDn?= <lnykryn@redhat.com>

Date: Fri, 7 Oct 2016 03:08:21 +0200

Subject: [PATCH] core: add possibility to set action for ctrl-alt-del burst

 (#4105)

For some certification, it should not be possible to reboot the machine through ctrl-alt-delete. Currently we suggest our customers to mask the ctrl-alt-delete target, but that is obviously not enough.

Patching the keymaps to disable that is really not a way to go for them, because the settings need to be easily checked by some SCAP tools.

Cherry-picked from: 24dd31c19ede505143833346ff850af942694aa6

Resolves: #1353028

---

 man/systemd-system.conf.xml | 11 ++++++++

 src/core/main.c             |  5 ++++

 src/core/manager.c          | 51 +++++++++++++++++++++++++++----------

 src/core/manager.h          | 14 +++++++++-

 src/core/system.conf        |  1 +

 5 files changed, 68 insertions(+), 14 deletions(-)

diff --git a/man/systemd-system.conf.xml b/man/systemd-system.conf.xml

index 39d19bc71..236c20d5f 100644

--- a/man/systemd-system.conf.xml

+++ b/man/systemd-system.conf.xml

@@ -101,6 +101,17 @@

         arguments.</para></listitem>

       </varlistentry>

+      <varlistentry>

+        <term><varname>CtrlAltDelBurstAction=</varname></term>

+

+        <listitem><para>Defines what action will be performed

+        if user presses Ctr-Alt-Delete more than 7 times in 2s.

+        Can be set to <literal>reboot-force</literal>, <literal>poweroff-force</literal>

+        or disabled with <literal>ignore</literal>. Defaults to

+        <literal>reboot-force</literal>.

+        </para></listitem>

+      </varlistentry>

+

       <varlistentry>

         <term><varname>CPUAffinity=</varname></term>

diff --git a/src/core/main.c b/src/core/main.c

index c9d8ce4a4..6ac9c9d44 100644

--- a/src/core/main.c

+++ b/src/core/main.c

@@ -115,6 +115,7 @@ static FILE* arg_serialization = NULL;

 static bool arg_default_cpu_accounting = false;

 static bool arg_default_blockio_accounting = false;

 static bool arg_default_memory_accounting = false;

+static CADBurstAction arg_cad_burst_action = CAD_BURST_ACTION_REBOOT;

 static void nop_handler(int sig) {}

@@ -625,6 +626,8 @@ static int config_parse_join_controllers(const char *unit,

         return 0;

 }

+static DEFINE_CONFIG_PARSE_ENUM(config_parse_cad_burst_action, cad_burst_action, CADBurstAction, "Failed to parse service restart specifier");

+

 static int parse_config_file(void) {

         const ConfigTableItem items[] = {

@@ -673,6 +676,7 @@ static int parse_config_file(void) {

                 { "Manager", "DefaultCPUAccounting",      config_parse_bool,             0, &arg_default_cpu_accounting            },

                 { "Manager", "DefaultBlockIOAccounting",  config_parse_bool,             0, &arg_default_blockio_accounting        },

                 { "Manager", "DefaultMemoryAccounting",   config_parse_bool,             0, &arg_default_memory_accounting         },

+                { "Manager", "CtrlAltDelBurstAction",     config_parse_cad_burst_action, 0, &arg_cad_burst_action},

                 {}

         };

@@ -1690,6 +1694,7 @@ int main(int argc, char *argv[]) {

         m->initrd_timestamp = initrd_timestamp;

         m->security_start_timestamp = security_start_timestamp;

         m->security_finish_timestamp = security_finish_timestamp;

+        m->cad_burst_action = arg_cad_burst_action;

         manager_set_default_rlimits(m, arg_default_rlimit);

         manager_environment_add(m, NULL, arg_default_environment);

diff --git a/src/core/manager.c b/src/core/manager.c

index 6d045fdf3..9048dde96 100644

--- a/src/core/manager.c

+++ b/src/core/manager.c

@@ -1859,6 +1859,35 @@ static int manager_start_target(Manager *m, const char *name, JobMode mode) {

         return r;

 }

+static void manager_handle_ctrl_alt_del(Manager *m) {

+        /* If the user presses C-A-D more than

+         * 7 times within 2s, we reboot/shutdown immediately,

+         * unless it was disabled in system.conf */

+

+        if (ratelimit_test(&m->ctrl_alt_del_ratelimit) || m->cad_burst_action == CAD_BURST_ACTION_IGNORE)

+                manager_start_target(m, SPECIAL_CTRL_ALT_DEL_TARGET, JOB_REPLACE_IRREVERSIBLY);

+        else {

+                switch (m->cad_burst_action) {

+

+                case CAD_BURST_ACTION_REBOOT:

+                        m->exit_code = MANAGER_REBOOT;

+                        break;

+

+                case CAD_BURST_ACTION_POWEROFF:

+                        m->exit_code = MANAGER_POWEROFF;

+                        break;

+

+                default:

+                        assert_not_reached("Unknown action.");

+                }

+

+                log_notice("Ctrl-Alt-Del was pressed more than 7 times within 2s, performing immediate %s.",

+                                cad_burst_action_to_string(m->cad_burst_action));

+                status_printf(NULL, true, false, "Ctrl-Alt-Del was pressed more than 7 times within 2s, performing immediate %s.",

+                                cad_burst_action_to_string(m->cad_burst_action));

+        }

+}

+

 static int manager_dispatch_signal_fd(sd_event_source *source, int fd, uint32_t revents, void *userdata) {

         Manager *m = userdata;

         ssize_t n;

@@ -1909,19 +1938,7 @@ static int manager_dispatch_signal_fd(sd_event_source *source, int fd, uint32_t

                 case SIGINT:

                         if (m->running_as == SYSTEMD_SYSTEM) {

-

-                                /* If the user presses C-A-D more than

-                                 * 7 times within 2s, we reboot

-                                 * immediately. */

-

-                                if (ratelimit_test(&m->ctrl_alt_del_ratelimit))

-                                        manager_start_target(m, SPECIAL_CTRL_ALT_DEL_TARGET, JOB_REPLACE_IRREVERSIBLY);

-                                else {

-                                        log_notice("Ctrl-Alt-Del was pressed more than 7 times within 2s, rebooting immediately.");

-                                        status_printf(NULL, true, false, "Ctrl-Alt-Del was pressed more than 7 times within 2s, rebooting immediately.");

-                                        m->exit_code = MANAGER_REBOOT;

-                                }

-

+                                manager_handle_ctrl_alt_del(m);

                                 break;

                         }

@@ -3319,3 +3336,11 @@ static const char *const manager_state_table[_MANAGER_STATE_MAX] = {

 };

 DEFINE_STRING_TABLE_LOOKUP(manager_state, ManagerState);

+

+static const char *const cad_burst_action_table[_CAD_BURST_ACTION_MAX] = {

+        [CAD_BURST_ACTION_IGNORE] = "ignore",

+        [CAD_BURST_ACTION_REBOOT] = "reboot-force",

+        [CAD_BURST_ACTION_POWEROFF] = "poweroff-force",

+};

+

+DEFINE_STRING_TABLE_LOOKUP(cad_burst_action, CADBurstAction);

diff --git a/src/core/manager.h b/src/core/manager.h

index 3e855db46..42be1fc43 100644

--- a/src/core/manager.h

+++ b/src/core/manager.h

@@ -64,6 +64,14 @@ typedef enum ManagerExitCode {

         _MANAGER_EXIT_CODE_INVALID = -1

 } ManagerExitCode;

+typedef enum CADBurstAction {

+        CAD_BURST_ACTION_IGNORE,

+        CAD_BURST_ACTION_REBOOT,

+        CAD_BURST_ACTION_POWEROFF,

+        _CAD_BURST_ACTION_MAX,

+        _CAD_BURST_ACTION_INVALID = -1

+} CADBurstAction;

+

 typedef enum StatusType {

         STATUS_TYPE_EPHEMERAL,

         STATUS_TYPE_NORMAL,

@@ -300,8 +308,9 @@ struct Manager {

         /* Used for processing polkit authorization responses */

         Hashmap *polkit_registry;

-        /* When the user hits C-A-D more than 7 times per 2s, reboot immediately... */

+        /* When the user hits C-A-D more than 7 times per 2s, do something immediately... */

         RateLimit ctrl_alt_del_ratelimit;

+        CADBurstAction cad_burst_action;

 };

 int manager_new(SystemdRunningAs running_as, bool test_run, Manager **m);

@@ -372,3 +381,6 @@ ManagerState manager_state(Manager *m);

 const char *manager_state_to_string(ManagerState m) _const_;

 ManagerState manager_state_from_string(const char *s) _pure_;

+

+const char *cad_burst_action_to_string(CADBurstAction a) _const_;

+CADBurstAction cad_burst_action_from_string(const char *s) _pure_;

diff --git a/src/core/system.conf b/src/core/system.conf

index 231609033..a11f59903 100644

--- a/src/core/system.conf

+++ b/src/core/system.conf

@@ -20,6 +20,7 @@

 #CrashShell=no

 #ShowStatus=yes

 #CrashChVT=1

+#CtrlAltDelBurstAction=reboot-force

 #CPUAffinity=1 2

 #JoinControllers=cpu,cpuacct net_cls,net_prio

 #RuntimeWatchdogSec=0