Add support for Systemd service type 'notify'

.travis.yml

@@ -24,6 +24,7 @@ addons:
     packages:
       - tree
       - libcap-dev
+      - libsystemd-dev
   coverity_scan:
     project:
       name: "troglobit/smcroute"

configure.ac

@@ -108,6 +108,17 @@ AS_IF([test "x$with_systemd" != "xno"],
      [AC_SUBST([systemddir], [$with_systemd])])
 AM_CONDITIONAL([HAVE_SYSTEMD], [test "x$with_systemd" != "xno"])
 
+have_libsystemd=no
+AS_IF([test "x$with_systemd" != "xno"],
+     [PKG_CHECK_MODULES(LIBSYSTEMD, libsystemd,
+         [AC_DEFINE(HAVE_LIBSYSTEMD, 1, [Enable libsystemd integration])
+         have_libsystemd=yes])]
+)
+AS_IF([test "x$have_libsystemd" = "xyes"],
+     [AC_SUBST([systemd_service_type], [notify])],
+     [AC_SUBST([systemd_service_type], [simple])])
+AM_CONDITIONAL([HAVE_LIBSYSTEMD], [test "x$have_libsystemd" = "xyes"])
+
 # Check if we need -lpthread (building statically) and -lrt (older GLIBC)
 # Unset cached values when retrying with -lpthread and reset LIBS for each API
 need_librt=no

smcroute.service.in

@@ -8,8 +8,9 @@ After=network-online.target
 Requires=network-online.target
 
 [Service]
-Type=simple
+Type=@systemd_service_type@
 ExecStart=@SBINDIR@/smcrouted -n -s
+NotifyAccess=main
 
 # Hardening settings
 NoNewPrivileges=true

src/Makefile.am

@@ -30,3 +30,7 @@ if USE_DOTCONF
 smcrouted_SOURCES      += conf.c conf.h
 endif
 
+if HAVE_LIBSYSTEMD
+smcrouted_CFLAGS      += $(LIBSYSTEMD_CFLAGS)
+smcrouted_LDADD       += $(LIBSYSTEMD_LIBS)
+endif

src/smcrouted.c

@@ -23,12 +23,17 @@
 #include <errno.h>
 #include <getopt.h>
 #include <stdio.h>
+#include <stdbool.h>
 #include <signal.h>
 #include <unistd.h>
 #include <arpa/inet.h>
 #include <sys/time.h>		/* gettimeofday() */
 #include <sys/un.h>
 
+#if HAVE_LIBSYSTEMD
+#include <systemd/sd-daemon.h>
+#endif
+
 #include "cap.h"
 #include "ipc.h"
 #include "log.h"
@@ -135,15 +140,34 @@ static void signal_init(void)
 
 static int server_loop(void)
 {
+#if HAVE_LIBSYSTEMD
+	bool need_sd_notify_ready = true;
+#endif
+
 	script_init(script);
 	mrdisc_init(interval);
 
 	while (running) {
 		if (reloading) {
+#if HAVE_LIBSYSTEMD
+			sd_notify(0, "RELOADING=1\n"
+				  "STATUS=Reloading configuration...\n");
+			need_sd_notify_ready = true;
+#endif
+
 			reload();
 			reloading = 0;
 		}
 
+
+#if HAVE_LIBSYSTEMD
+		if (need_sd_notify_ready) {
+			sd_notify(0, "READY=1\n"
+				  "STATUS=Configuration loaded.\n");
+			need_sd_notify_ready = false;
+		}
+#endif
+
 		socket_poll(NULL);
 	}