cmdmon: add shutdown command

The command is functionally equivalent to sending the process the
SIGTERM signal.

candm.h

@@ -99,7 +99,8 @@
 #define REQ_ADD_PEER2 59
 #define REQ_ADD_SERVER3 60
 #define REQ_ADD_PEER3 61
-#define N_REQUEST_TYPES 62
+#define REQ_SHUTDOWN 62
+#define N_REQUEST_TYPES 63
 
 /* Structure used to exchange timespecs independent of time_t size */
 typedef struct {

client.c

@@ -1246,6 +1246,7 @@ give_help(void)
     "cyclelogs\0Close and re-open log files\0"
     "dump\0Dump all measurements to save files\0"
     "rekey\0Re-read keys from key file\0"
+    "shutdown\0Stop daemon\0"
     "\0\0"
     "Client commands:\0\0"
     "dns -n|+n\0Disable/enable resolving IP addresses to hostnames\0"
@@ -1280,9 +1281,9 @@ command_name_generator(const char *text, int state)
     "maxdelay", "maxdelaydevratio", "maxdelayratio", "maxpoll",
     "maxupdateskew", "minpoll", "minstratum", "ntpdata", "offline", "online",
     "polltarget", "quit", "refresh", "rekey", "reselect", "reselectdist",
-    "retries", "rtcdata", "serverstats", "settime", "smoothing", "smoothtime",
-    "sources", "sources -v", "sourcestats", "sourcestats -v", "timeout",
-    "tracking", "trimrtc", "waitsync", "writertc",
+    "retries", "rtcdata", "serverstats", "settime", "shutdown", "smoothing",
+    "smoothtime", "sources", "sources -v", "sourcestats", "sourcestats -v",
+    "timeout", "tracking", "trimrtc", "waitsync", "writertc",
     NULL
   };
   static int list_index, len;
@@ -2707,6 +2708,14 @@ process_cmd_refresh(CMD_Request *msg, char *line)
 
 /* ================================================== */
 
+static void
+process_cmd_shutdown(CMD_Request *msg, char *line)
+{
+  msg->command = htons(REQ_SHUTDOWN);
+}
+
+/* ================================================== */
+
 static int
 process_cmd_waitsync(char *line)
 {
@@ -3002,6 +3011,8 @@ process_line(char *line)
   } else if (!strcmp(command, "settime")) {
     do_normal_submit = 0;
     ret = process_cmd_settime(line);
+  } else if (!strcmp(command, "shutdown")) {
+    process_cmd_shutdown(&tx_message, line);
   } else if (!strcmp(command, "smoothing")) {
     do_normal_submit = 0;
     ret = process_cmd_smoothing(line);

cmdmon.c

@@ -138,6 +138,7 @@ static const char permissions[] = {
   PERMIT_AUTH, /* ADD_PEER2 */
   PERMIT_AUTH, /* ADD_SERVER3 */
   PERMIT_AUTH, /* ADD_PEER3 */
+  PERMIT_AUTH, /* SHUTDOWN */
 };
 
 /* ================================================== */
@@ -1239,6 +1240,15 @@ handle_ntp_data(CMD_Request *rx_message, CMD_Reply *tx_message)
   memset(tx_message->data.ntp_data.reserved, 0xff, sizeof (tx_message->data.ntp_data.reserved));
 }
 
+/* ================================================== */
+
+static void
+handle_shutdown(CMD_Request *rx_message, CMD_Reply *tx_message)
+{
+  LOG(LOGS_INFO, "Received shutdown command");
+  SCH_QuitProgram();
+}
+
 /* ================================================== */
 /* Read a packet and process it */
 
@@ -1630,6 +1640,10 @@ read_from_cmd_socket(int sock_fd, int event, void *anything)
           handle_ntp_data(&rx_message, &tx_message);
           break;
 
+        case REQ_SHUTDOWN:
+          handle_shutdown(&rx_message, &tx_message);
+          break;
+
         default:
           DEBUG_LOG("Unhandled command %d", rx_command);
           tx_message.status = htons(STT_FAILED);

doc/chronyc.adoc

@@ -1128,6 +1128,10 @@ running.
 The *rekey* command causes *chronyd* to re-read the key file specified in the
 configuration file by the <<chrony.conf.adoc#keyfile,*keyfile*>> directive.
 
+[[rekey]]*shutdown*::
+The *shutdown* command causes *chronyd* to exit. This is equivalent to sending
+the process the SIGTERM signal.
+
 === Client commands
 
 [[dns]]*dns* _option_::

pktlength.c

@@ -118,6 +118,7 @@ static const struct request_length request_lengths[] = {
   { 0, 0 },                                     /* ADD_PEER2 */
   REQ_LENGTH_ENTRY(ntp_source, null),           /* ADD_SERVER3 */
   REQ_LENGTH_ENTRY(ntp_source, null),           /* ADD_PEER3 */
+  REQ_LENGTH_ENTRY(null, null),                 /* SHUTDOWN */
 };
 
 static const uint16_t reply_lengths[] = {