Add support for starting/stopping SysV init scripts

This patch adds initial support for starting a SysV init script in a
runlevel, and stopping it when leaving a runlevel.

    sysv [LVLS] <COND> /path/to/script.sh -- Optional Description

The SysV /etc/inittab file, which may use /etc/init.d, or /etc/rcN.d,
is still not supported.  A separate plugin would be required for this,
see the documentation for more information.

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

docs/config.md

@@ -152,6 +152,20 @@ Syntax
         task [s] echo "foo" | cat >/tmp/bar
 ```
 
+* `sysv [LVLS] <COND> /path/to/init-script -- Optional description`__
+  Similar to `task` is the `sysv` stanza, which can be used to call SysV
+  style scripts.  The primary intention for this command is to be able to
+  re-use much of existing setup and init scripts in Linux distributions.
+  
+  When entering an allowed runlevel, Finit calls `init-script start`,
+  when entering a disallowed runlevel, Finit calls `init-script stop`,
+  and if the Finit .conf, where `sysv` stanza is declared, is modified,
+  Finit calls `init-script restart` on `initctl restart`.  Similar
+  to how a `service` stanza works.
+  
+  > **Note:** there is currently now supervision of daemons started as
+  > sysv services.  I.e., the `pid:!...` support is still missing.
+
 * `service [LVLS] <COND> /path/to/daemon ARGS -- Optional description`  
   Service, or daemon, to be monitored and automatically restarted if it
   exits prematurely.  Please note that you often need to provide a

src/cond-w.c

@@ -128,6 +128,7 @@ static int svc_has_cond(svc_t *svc)
 	case SVC_TYPE_SERVICE:
 	case SVC_TYPE_TASK:
 	case SVC_TYPE_RUN:
+	case SVC_TYPE_SYSV:
 		return 1;
 
 	default:

src/conf.c

@@ -464,6 +464,12 @@ static void parse_dynamic(char *line, struct rlimit rlimit[], char *file)
 		return;
 	}
 
+	/* Similar to task but is treated like a SysV init script */
+	if (MATCH_CMD(line, "sysv ", x)) {
+		service_register(SVC_TYPE_SYSV, x, rlimit, file);
+		return;
+	}
+
 	/* Classic inetd service */
 	if (MATCH_CMD(line, "inetd ", x)) {
 #ifdef INETD_ENABLED

src/service.c

@@ -166,12 +166,19 @@ static int service_start(svc_t *svc)
 	if (svc_is_inetd(svc))
 		return inetd_start(&svc->inetd);
 #endif
+	if (svc_is_sysv(svc)) {
+		_d("Starting SYSV script %s", svc->cmd);
+		if (svc_is_runtask(svc))
+			_d("SYSV is class:runtask");
+		else
+			_d("SYSV is *NOT* class:runtask");
+	}
 
 	if (!svc->desc[0])
 		do_progress = 0;
 
 	if (do_progress) {
-		if (svc_is_daemon(svc))
+		if (svc_is_daemon(svc) || svc_is_sysv(svc))
 			print_desc("Starting ", svc->desc);
 		else
 			print_desc("", svc->desc);
@@ -224,9 +231,15 @@ static int service_start(svc_t *svc)
 			}
 		}
 
-		/* Serve copy of args to process in case it modifies them. */
+		if (!svc_is_sysv(svc)) {
-		for (i = 0; i < (MAX_NUM_SVC_ARGS - 1) && svc->args[i][0] != 0; i++)
+			/* Serve copy of args to process in case it modifies them. */
-			args[i] = svc->args[i];
+			for (i = 0; i < (MAX_NUM_SVC_ARGS - 1) && svc->args[i][0] != 0; i++)
+				args[i] = svc->args[i];
+		} else {
+			i = 0;
+			args[i++] = svc->cmd;
+			args[i++] = "start";
+		}
 		args[i] = NULL;
 
 		/* Redirect inetd socket to stdin for connection */
@@ -454,18 +467,43 @@ static int service_stop(svc_t *svc)
 #endif
 	service_timeout_cancel(svc);
 
-	if (svc->pid <= 1)
+	if (!svc_is_sysv(svc)) {
-		return 1;
+		if (svc->pid <= 1)
+			return 1;
+
+		_d("Sending SIGTERM to pid:%d name:%s", svc->pid, pid_get_name(svc->pid, NULL, 0));
+		logit(LOG_CONSOLE | LOG_NOTICE, "Stopping %s:%s, PID: %d, sending SIGTERM ...",
+		      basename(svc->cmd), svc->id, svc->pid);
+	} else {
+		logit(LOG_CONSOLE | LOG_NOTICE, "Calling '%s stop' ...", svc->cmd);
+	}
 
-	_d("Sending SIGTERM to pid:%d name:%s", svc->pid, pid_get_name(svc->pid, NULL, 0));
-	logit(LOG_CONSOLE | LOG_NOTICE, "Stopping %s:%s, PID: %d, sending SIGTERM ...",
-	      basename(svc->cmd), svc->id, svc->pid);
 	svc_set_state(svc, SVC_STOPPING_STATE);
 
 	if (runlevel != 1)
 		print_desc("Stopping ", svc->desc);
 
-	res = kill(svc->pid, SIGTERM);
+	if (!svc_is_sysv(svc)) {
+		res = kill(svc->pid, SIGTERM);
+	} else {
+		char *args[] = { svc->cmd, "stop", NULL };
+		pid_t pid;
+
+		pid = fork();
+		switch (pid) {
+		case 0:
+			exec_runtask(svc->cmd, args);
+			_exit(0);
+			break;
+		case -1:
+			_pe("Failed fork() to call sysv script '%s stop'", svc->cmd);
+			res = 1;
+			break;
+		default:
+			res = WEXITSTATUS(complete(svc->cmd, pid));
+			break;
+		}
+	}
 
 	if (runlevel != 1)
 		print_result(res);
@@ -473,6 +511,15 @@ static int service_stop(svc_t *svc)
 	return res;
 }
 
+/*
+ * SysV start/stop script wrapper for service_stop()
+ */
+static int sysv_stop(svc_t *svc)
+{
+	svc_set_state(svc, SVC_READY_STATE);
+	return service_stop(svc);
+}
+
 /**
  * service_restart - Restart a service by sending %SIGHUP
  * @svc: Service to reload
@@ -1092,6 +1139,14 @@ restart:
 	case SVC_HALTED_STATE:
 		if (enabled)
 			svc_set_state(svc, SVC_READY_STATE);
+
+		if (svc_is_sysv(svc)) {
+			if (!enabled && sm_is_in_teardown(&sm)) {
+				sysv_stop(svc);
+				svc_set_state(svc, SVC_HALTED_STATE);
+			}
+			break;
+		}
 		break;
 
 	case SVC_DONE_STATE:
@@ -1119,6 +1174,7 @@ restart:
 			case SVC_TYPE_INETD_CONN:
 			case SVC_TYPE_TASK:
 			case SVC_TYPE_RUN:
+			case SVC_TYPE_SYSV:
 				svc_set_state(svc, SVC_DONE_STATE);
 				break;
 

src/sm.c

@@ -117,7 +117,7 @@ restart:
 	switch (sm->state) {
 	case SM_BOOTSTRAP_STATE:
 		_d("Bootstrapping all services in runlevel S from %s", FINIT_CONF);
-		service_step_all(SVC_TYPE_RUN | SVC_TYPE_TASK | SVC_TYPE_SERVICE);
+		service_step_all(SVC_TYPE_RUNTASK | SVC_TYPE_SERVICE);
 		sm->state = SM_RUNNING_STATE;
 		break;
 

src/svc.h

@@ -43,10 +43,11 @@ typedef enum {
 	SVC_TYPE_RUN        = 4,	/* Like task, but wait for completion */
 	SVC_TYPE_INETD      = 8,	/* Classic inetd service */
 	SVC_TYPE_INETD_CONN = 16,	/* Single inetd connection */
+	SVC_TYPE_SYSV       = 32,	/* SysV style init.d script w/ start/stop */
 } svc_type_t;
 
 #define SVC_TYPE_ANY          (-1)
-#define SVC_TYPE_RUNTASK      (6)
+#define SVC_TYPE_RUNTASK      (SVC_TYPE_RUN | SVC_TYPE_TASK | SVC_TYPE_SYSV)
 
 typedef enum {
 	SVC_HALTED_STATE = 0,	/* Not allowed in runlevel, or not enabled. */
@@ -182,6 +183,7 @@ int         svc_parse_jobstr       (char *str, size_t len, int (*found)(svc_t *)
 static inline int svc_is_inetd     (svc_t *svc) { return svc && SVC_TYPE_INETD      == svc->type; }
 static inline int svc_is_inetd_conn(svc_t *svc) { return svc && SVC_TYPE_INETD_CONN == svc->type; }
 static inline int svc_is_daemon    (svc_t *svc) { return svc && SVC_TYPE_SERVICE    == svc->type; }
+static inline int svc_is_sysv      (svc_t *svc) { return svc && SVC_TYPE_SYSV       == svc->type; }
 static inline int svc_is_runtask   (svc_t *svc) { return svc && (SVC_TYPE_RUNTASK & svc->type);   }
 
 static inline int svc_in_runlevel  (svc_t *svc, int runlevel) { return svc && ISSET(svc->runlevels, runlevel); }