Support for custom halt:signal, default SIGTERM

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

docs/config.md

@@ -231,6 +231,13 @@ Syntax
 
         name:<service-name>
 
+  When stopping a service (run/task/sysv/service), either manually or
+  when moving to another runlevel, Finit starts by sending `SIGTERM`, to
+  allow the process to shut down gracefully.  If the process has not
+  been collected within 3 seconds, Finit sends `SIGKILL`.  To halt the
+  process using a different signal, use the option `halt:SIGNAL`, e.g.,
+  `halt:SIGPWR`.
+
 * `inetd service/proto[@iflist] <wait|nowait> [LVLS] /path/to/daemon args`  
   Launch a daemon when a client initiates a connection on an Internet
   port.  Available services are listed in the UNIX `/etc/services` file.

src/service.c

@@ -472,9 +472,10 @@ static int service_stop(svc_t *svc)
 		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);
+		_d("Sending %s to pid:%d name:%s", sig_name(svc->sighalt),
+		   svc->pid, pid_get_name(svc->pid, NULL, 0));
+		logit(LOG_CONSOLE | LOG_NOTICE, "Stopping %s:%s, PID: %d, sending %s ...",
+		      basename(svc->cmd), svc->id, svc->pid, sig_name(svc->sighalt));
 	} else {
 		logit(LOG_CONSOLE | LOG_NOTICE, "Calling '%s stop' ...", svc->cmd);
 	}
@@ -488,7 +489,7 @@ static int service_stop(svc_t *svc)
 		if (svc->pid <= 1)
 			goto cleanup;
 
-		res = kill(svc->pid, SIGTERM);
+		res = kill(svc->pid, svc->sighalt);
 
 		/* PID lost or forking process never really started */
 		if (res == -1 && ESRCH == errno) {
@@ -644,6 +645,17 @@ static void parse_log(svc_t *svc, char *arg)
 	}
 }
 
+static void parse_sighalt(svc_t *svc, char *arg)
+{
+	int signo;
+
+	signo = sig_num(arg);
+	if (signo == -1)
+		return;
+
+	svc->sighalt = signo;
+}
+
 /*
  * name:<name>
  */
@@ -757,7 +769,7 @@ int service_register(int type, char *cfg, struct rlimit rlimit[], char *file)
 	char *username = NULL, *log = NULL, *pid = NULL;
 	char *service = NULL, *proto = NULL, *ifaces = NULL;
 	char *cmd, *desc, *runlevels = NULL, *cond = NULL;
-	char *name = NULL;
+	char *name = NULL, *halt = NULL;
 	svc_t *svc;
 	plugin_t *plugin = NULL;
 
@@ -819,6 +831,8 @@ int service_register(int type, char *cfg, struct rlimit rlimit[], char *file)
 			name = cmd;
 		else if (!strncasecmp(cmd, "manual:yes", 10))
 			manual = 1;
+		else if (!strncasecmp(cmd, "halt:", 5))
+			halt = &cmd[5];
 		else if (cmd[0] != '/' && strchr(cmd, '/'))
 			service = cmd;   /* inetd service/proto */
 		else
@@ -945,7 +959,8 @@ recreate:
 	conf_parse_cond(svc, cond);
 
 	parse_name(svc, name);
-
+	if (halt)
+		parse_sighalt(svc, halt);
 	if (log)
 		parse_log(svc, log);
 	if (desc)

src/sig.c

@@ -98,6 +98,55 @@ static uev_t sighup_watcher,  sigint_watcher,  sigpwr_watcher;
 static uev_t sigchld_watcher;
 static uev_t sigstop_watcher, sigtstp_watcher, sigcont_watcher;
 
+static struct sigmap {
+	int   num;
+	char *name;
+} signames[] = {
+	/* ISO C99 signals.  */
+	{ SIGINT,    "SIGINT"    },
+	{ SIGILL,    "SIGILL"    },
+	{ SIGABRT,   "SIGABRT"   },
+	{ SIGFPE,    "SIGFPE"    },
+	{ SIGSEGV,   "SIGSEGV"   },
+	{ SIGTERM,   "SIGTERM"   },
+	/* Historical signals specified by POSIX. */
+	{ SIGHUP,    "SIGHUP"    },
+	{ SIGQUIT,   "SIGQUIT"   },
+	{ SIGTRAP,   "SIGTRAP"   },
+	{ SIGKILL,   "SIGKILL"   },
+	{ SIGBUS,    "SIGBUS"    },
+	{ SIGSYS,    "SIGSYS"    },
+	{ SIGPIPE,   "SIGPIPE"   },
+	{ SIGALRM,   "SIGALRM"   },
+
+	/* New(er) POSIX signals (1003.1-2008, 1003.1-2013). */
+	{ SIGURG,    "SIGURG"    },
+	{ SIGSTOP,   "SIGSTOP"   },
+	{ SIGTSTP,   "SIGTSTP"   },
+	{ SIGCONT,   "SIGCONT"   },
+	{ SIGCHLD,   "SIGCHLD"   },
+	{ SIGTTIN,   "SIGTTIN"   },
+	{ SIGTTOU,   "SIGTTOU"   },
+	{ SIGPOLL,   "SIGPOLL"   },
+	{ SIGXCPU,   "SIGXCPU"   },
+	{ SIGXFSZ,   "SIGXFSZ"   },
+	{ SIGVTALRM, "SIGVTALRM" },
+	{ SIGPROF,   "SIGPROF"   },
+	{ SIGUSR1,   "SIGUSR1"   },
+	{ SIGUSR2,   "SIGUSR2"   },
+
+	/* Nonstandard signals found in all modern POSIX systems
+	   (including both BSD and Linux).  */
+	{ SIGWINCH,  "SIGWINCH"  },
+	{ SIGSTKFLT, "SIGSTKFLT" },
+	{ SIGPWR,    "SIGPWR"    },
+
+	/* Archaic names for compatibility.  */
+	{ SIGIO,     "SIGIO"     },
+	{ SIGIOT,    "SIGIOT"    },
+	{ SIGCLD,    "SIGCLD"    },
+};
+
 void mdadm_wait(void);
 void unmount_tmpfs(void);
 void unmount_regular(void);
@@ -369,6 +418,38 @@ int sig_stopped(void)
 	return stopped;
 }
 
+/*
+ * Convert SIGFOO to a number, if it exists
+ */
+int sig_num(const char *name)
+{
+	size_t i, offset = 0;
+
+	if (strncasecmp(name, "SIG", 3))
+		offset = 3;
+
+	for (i = 0; i < NELEMS(signames); i++) {
+		if (strcasecmp(name, &signames[i].name[offset]))
+			continue;
+
+		return signames[i].num;
+	}
+
+	return -1;
+}
+
+const char *sig_name(int signo)
+{
+	size_t i;
+
+	for (i = 0; i < NELEMS(signames); i++) {
+		if (signames[i].num == signo)
+			return signames[i].name;
+	}
+
+	return "SIGUNKOWN";
+}
+
 /*
  * Inital signal setup - ignore everything but SIGCHLD until we're capable of responding
  */

src/sig.h

@@ -70,10 +70,13 @@ extern shutop_t halt;
 
 void do_shutdown    (shutop_t op);
 int  sig_stopped    (void);
+int  sig_num        (const char *name);
 void sig_init       (void);
 void sig_unblock    (void);
 void sig_setup      (uev_ctx_t *ctx);
 
+const char *sig_name(int signo);
+
 #endif /* FINIT_SIG_H_ */
 
 /**

src/svc.c

@@ -104,6 +104,9 @@ svc_t *svc_new(char *cmd, char *id, int type)
 	/* Default description, if missing */
 	strlcpy(svc->desc, svc->name, sizeof(svc->desc));
 
+	/* Default HALT signal to send */
+	svc->sighalt = SIGTERM;
+
 	TAILQ_INSERT_TAIL(&svc_list, svc, link);
 
 	return svc;

src/svc.h

@@ -75,7 +75,7 @@ typedef enum {
 #define MAX_NUM_FDS      64	     /* Max number of I/O plugins */
 #define MAX_NUM_SVC_ARGS 32
 
-/* Time after SIGTERM that we SIGKILL stopping processes */
+/* Time after SIGTERM (svc->sighalt) that we SIGKILL stopping processes */
 #define SVC_TERM_TIMEOUT 3000
 
 /*
@@ -95,6 +95,7 @@ typedef struct svc {
 	struct rlimit  rlimit[RLIMIT_NLIMITS];
 
 	/* Service details */
+	int            sighalt;        /* Signal to stop prorcess, default: SIGTERM */
 	pid_t	       pid;
 	char           pidfile[256];
 	long           start_time;     /* Start time, as seconds since boot, from sysinfo() */