Notify tunnel up to systemd with sd_notify

Allows usage of Type=notify systemd service types.

Fixes: #229

Makefile.am

@@ -9,8 +9,8 @@ openfortivpn_SOURCES = src/config.c src/config.h src/hdlc.c src/hdlc.h \
 openfortivpn_CFLAGS = -Wall --pedantic -std=gnu99
 openfortivpn_CPPFLAGS = -DSYSCONFDIR=\"$(sysconfdir)\"
 
-openfortivpn_CPPFLAGS += $(OPENSSL_CFLAGS)
-openfortivpn_LDADD = $(OPENSSL_LIBS)
+openfortivpn_CPPFLAGS += $(OPENSSL_CFLAGS) $(LIBSYSTEMD_CFLAGS)
+openfortivpn_LDADD = $(OPENSSL_LIBS) $(LIBSYSTEMD_LIBS)
 
 DISTCHECK_CONFIGURE_FLAGS = CFLAGS=-Werror
 

configure.ac

@@ -21,6 +21,7 @@ AM_SILENT_RULES([yes])
 PKG_CHECK_MODULES(OPENSSL, [libcrypto >= 0.9.8 libssl >= 0.9.8], [], [AC_MSG_ERROR([Cannot find OpenSSL 0.9.8 or higher.])])
 AC_CHECK_LIB([pthread], [pthread_create], [], [AC_MSG_ERROR([Cannot find libpthread.])])
 AC_CHECK_LIB([util], [forkpty], [], [AC_MSG_ERROR([Cannot find libutil.])])
+PKG_CHECK_MODULES(LIBSYSTEMD, [libsystemd], [AC_DEFINE(HAVE_SYSTEMD)], [ ])
 
 # Checks for header files.
 AC_CHECK_HEADERS([arpa/inet.h assert.h ctype.h errno.h fcntl.h getopt.h ifaddrs.h limits.h mach/mach.h netdb.h net/if.h netinet/in.h netinet/tcp.h net/route.h pty.h semaphore.h signal.h stdarg.h stddef.h stdint.h stdio.h stdlib.h string.h strings.h sys/ioctl.h syslog.h sys/socket.h sys/stat.h sys/time.h sys/types.h sys/wait.h termios.h unistd.h util.h])

src/tunnel.c

@@ -50,6 +50,9 @@
 #include <signal.h>
 #include <sys/wait.h>
 #include <assert.h>
+#if HAVE_SYSTEMD
+#include <systemd/sd-daemon.h>
+#endif
 
 struct ofv_varr {
 	unsigned cap;		// current capacity
@@ -101,6 +104,10 @@ static int on_ppp_if_up(struct tunnel *tunnel)
 
 	log_info("Tunnel is up and running.\n");
 
+#if HAVE_SYSTEMD
+	sd_notify(0, "READY=1");
+#endif
+
 	return 0;
 }