libsystemd: translate leading log <LEVEL> in stderr logging

This commit also switches the stdout/stderr log capture backend for all
notify:systemd services from the sysklogd project's logger tool to the
bundled logit tool.

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

libsystemd/sd-daemon.h

@@ -6,6 +6,16 @@
 
 #define SD_LISTEN_FDS_START 3
 
+/* systemd logging defines for stderr parsing by Finit */
+#define SD_EMERG    "<0>"  /* system is unusable */
+#define SD_ALERT    "<1>"  /* action must be taken immediately */
+#define SD_CRIT     "<2>"  /* critical conditions */
+#define SD_ERR      "<3>"  /* error conditions */
+#define SD_WARNING  "<4>"  /* warning conditions */
+#define SD_NOTICE   "<5>"  /* normal but significant condition */
+#define SD_INFO     "<6>"  /* informational */
+#define SD_DEBUG    "<7>"  /* debug-level messages */
+
 /* Basic notification function */
 int sd_notify(int unset_environment, const char *state);
 

src/service.c

@@ -342,6 +342,7 @@ static int lredirect(svc_t *svc)
 		if (svc->log.prio[0])
 			prio = svc->log.prio;
 
+		/* Neither sysklogd logger or native logit tool available */
 		if (!have_sysklogd && !whichp(_PATH_LOGIT)) {
 			logit(LOG_INFO, _PATH_LOGIT " missing, using syslog for %s instead", svc->name);
 			fallback_logger(tag, prio);
@@ -367,7 +368,13 @@ static int lredirect(svc_t *svc)
 			_exit(1);
 		}
 
-		if (have_sysklogd) {
+		/*
+		 * For now, let systemd programs go via our native logit
+		 * tool.  It supports systemd logging defines for stderr
+		 * parsing.  The only real downside is that it cannot do
+		 * PID faking, like sysklogd's logger tool.
+		 */
+		if (have_sysklogd && svc->notify != SVC_NOTIFY_SYSTEMD) {
 			char pid[16];
 
 			snprintf(pid, sizeof(pid), "%d", svc_pid);