sd_notify (systemd status notifications) support

sd_notify() is used to notify systemd of changes to the status of the
process. This allows the systemd daemon to know when the process
finished loading (and thus only start another program after Asterisk has
finished loading).

To use this, use a systemd unit with 'Type=notify' for Asterisk.

This commit also adds the function ast_sd_notify(), a wrapper around
sd_notify that does nothing if not built with systemd support.

Also adds support for libsystemd detection in the configure script.

Change-Id: Ied6a59dafd5ef331c5c7ae8f3ccd2dfc94be7811

10 files changed, 163 insertions, 6 deletions

diff --git a/CHANGES b/CHANGES
index 38228e37a..da732a7eb 100644
--- a/CHANGES
+++ b/CHANGES
@@ -347,6 +347,10 @@ Core
    in the context. If enabled a device state hint will be automatically created
    with the name of the device.
 
+* If Asterisk is built with systemd support, and run under systemd, it will
+  notify systemd of its state using sd_notify. Use 'Type=notify' in
+  asterisk.service.
+
 Functions
 ------------------
  * The func_odbc global option "single_db_connection" default value has been
diff --git a/configure b/configure
index 51f062328..a5da739c0 100755
--- a/configure
+++ b/configure
@@ -639,6 +639,11 @@ PBX_SYSLOG_FACILITY_LOG_DAEMON
 PBX_SYSLOG_FACILITY_LOG_CRON
 PBX_SYSLOG_FACILITY_LOG_AUTHPRIV
 PBX_SYSLOG_FACILITY_LOG_AUTH
+SYSTEMD_LIBS
+SYSTEMD_CFLAGS
+SYSTEMD_INCLUDE
+SYSTEMD_LIB
+PBX_SYSTEMD
 PBX_GENERIC_ODBC
 GENERIC_ODBC_INCLUDE
 GENERIC_ODBC_LIB
@@ -1320,6 +1325,7 @@ infodir
 docdir
 oldincludedir
 includedir
+runstatedir
 localstatedir
 sharedstatedir
 sysconfdir
@@ -1460,7 +1466,9 @@ PYTHONDEV_LIBS
 GMIME_CFLAGS
 GMIME_LIBS
 GTK2_CFLAGS
-GTK2_LIBS'
+GTK2_LIBS
+SYSTEMD_CFLAGS
+SYSTEMD_LIBS'
 
 
 # Initialize some variables set by options.
@@ -1499,6 +1507,7 @@ datadir='${datarootdir}'
 sysconfdir='${prefix}/etc'
 sharedstatedir='${prefix}/com'
 localstatedir='${prefix}/var'
+runstatedir='${localstatedir}/run'
 includedir='${prefix}/include'
 oldincludedir='/usr/include'
 docdir='${datarootdir}/doc/${PACKAGE_TARNAME}'
@@ -1751,6 +1760,15 @@ do
   | -silent | --silent | --silen | --sile | --sil)
     silent=yes ;;
 
+  -runstatedir | --runstatedir | --runstatedi | --runstated \
+  | --runstate | --runstat | --runsta | --runst | --runs \
+  | --run | --ru | --r)
+    ac_prev=runstatedir ;;
+  -runstatedir=* | --runstatedir=* | --runstatedi=* | --runstated=* \
+  | --runstate=* | --runstat=* | --runsta=* | --runst=* | --runs=* \
+  | --run=* | --ru=* | --r=*)
+    runstatedir=$ac_optarg ;;
+
   -sbindir | --sbindir | --sbindi | --sbind | --sbin | --sbi | --sb)
     ac_prev=sbindir ;;
   -sbindir=* | --sbindir=* | --sbindi=* | --sbind=* | --sbin=* \
@@ -1888,7 +1906,7 @@ fi
 for ac_var in	exec_prefix prefix bindir sbindir libexecdir datarootdir \
 		datadir sysconfdir sharedstatedir localstatedir includedir \
 		oldincludedir docdir infodir htmldir dvidir pdfdir psdir \
-		libdir localedir mandir
+		libdir localedir mandir runstatedir
 do
   eval ac_val=\$$ac_var
   # Remove trailing slashes.
@@ -2041,6 +2059,7 @@ Fine tuning of the installation directories:
   --sysconfdir=DIR        read-only single-machine data [PREFIX/etc]
   --sharedstatedir=DIR    modifiable architecture-independent data [PREFIX/com]
   --localstatedir=DIR     modifiable single-machine data [PREFIX/var]
+  --runstatedir=DIR       modifiable per-process data [LOCALSTATEDIR/run]
   --libdir=DIR            object code libraries [EPREFIX/lib]
   --includedir=DIR        C header files [PREFIX/include]
   --oldincludedir=DIR     C header files for non-gcc [/usr/include]
@@ -2213,6 +2232,10 @@ Some influential environment variables:
   GMIME_LIBS  linker flags for GMIME, overriding pkg-config
   GTK2_CFLAGS C compiler flags for GTK2, overriding pkg-config
   GTK2_LIBS   linker flags for GTK2, overriding pkg-config
+  SYSTEMD_CFLAGS
+              C compiler flags for SYSTEMD, overriding pkg-config
+  SYSTEMD_LIBS
+              linker flags for SYSTEMD, overriding pkg-config
 
 Use these variables to override the choices made by `configure' or to help
 it to find libraries and programs with nonstandard names/locations.
@@ -34811,6 +34834,98 @@ fi
 
 
 
+
+
+
+
+   if test "x${PBX_SYSTEMD}" != "x1" -a "${USE_SYSTEMD}" != "no"; then
+
+pkg_failed=no
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for SYSTEMD" >&5
+$as_echo_n "checking for SYSTEMD... " >&6; }
+
+if test -n "$SYSTEMD_CFLAGS"; then
+    pkg_cv_SYSTEMD_CFLAGS="$SYSTEMD_CFLAGS"
+ elif test -n "$PKG_CONFIG"; then
+    if test -n "$PKG_CONFIG" && \
+    { { $as_echo "$as_me:${as_lineno-$LINENO}: \$PKG_CONFIG --exists --print-errors \"libsystemd\""; } >&5
+  ($PKG_CONFIG --exists --print-errors "libsystemd") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; then
+  pkg_cv_SYSTEMD_CFLAGS=`$PKG_CONFIG --cflags "libsystemd" 2>/dev/null`
+		      test "x$?" != "x0" && pkg_failed=yes
+else
+  pkg_failed=yes
+fi
+ else
+    pkg_failed=untried
+fi
+if test -n "$SYSTEMD_LIBS"; then
+    pkg_cv_SYSTEMD_LIBS="$SYSTEMD_LIBS"
+ elif test -n "$PKG_CONFIG"; then
+    if test -n "$PKG_CONFIG" && \
+    { { $as_echo "$as_me:${as_lineno-$LINENO}: \$PKG_CONFIG --exists --print-errors \"libsystemd\""; } >&5
+  ($PKG_CONFIG --exists --print-errors "libsystemd") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; then
+  pkg_cv_SYSTEMD_LIBS=`$PKG_CONFIG --libs "libsystemd" 2>/dev/null`
+		      test "x$?" != "x0" && pkg_failed=yes
+else
+  pkg_failed=yes
+fi
+ else
+    pkg_failed=untried
+fi
+
+
+
+if test $pkg_failed = yes; then
+   	{ $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+
+if $PKG_CONFIG --atleast-pkgconfig-version 0.20; then
+        _pkg_short_errors_supported=yes
+else
+        _pkg_short_errors_supported=no
+fi
+        if test $_pkg_short_errors_supported = yes; then
+	        SYSTEMD_PKG_ERRORS=`$PKG_CONFIG --short-errors --print-errors --cflags --libs "libsystemd" 2>&1`
+        else
+	        SYSTEMD_PKG_ERRORS=`$PKG_CONFIG --print-errors --cflags --libs "libsystemd" 2>&1`
+        fi
+	# Put the nasty error message in config.log where it belongs
+	echo "$SYSTEMD_PKG_ERRORS" >&5
+
+
+            PBX_SYSTEMD=0
+
+
+elif test $pkg_failed = untried; then
+     	{ $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+
+            PBX_SYSTEMD=0
+
+
+else
+	SYSTEMD_CFLAGS=$pkg_cv_SYSTEMD_CFLAGS
+	SYSTEMD_LIBS=$pkg_cv_SYSTEMD_LIBS
+        { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+
+            PBX_SYSTEMD=1
+            SYSTEMD_INCLUDE="$SYSTEMD_CFLAGS"
+            SYSTEMD_LIB="$SYSTEMD_LIBS"
+
+$as_echo "#define HAVE_SYSTEMD 1" >>confdefs.h
+
+
+fi
+   fi
+
+
 PBX_SYSLOG=0
 
 if test "${ac_cv_header_syslog_h}" = "yes"; then
diff --git a/configure.ac b/configure.ac
index e7fc21c66..17b887266 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2630,6 +2630,11 @@ AC_SUBST([GENERIC_ODBC_LIB])
 AC_SUBST([GENERIC_ODBC_INCLUDE])
 AC_SUBST([PBX_GENERIC_ODBC])
 
+AC_SUBST([PBX_SYSTEMD])
+AC_SUBST([SYSTEMD_LIB])
+AC_SUBST([SYSTEMD_INCLUDE])
+AST_PKG_CONFIG_CHECK([SYSTEMD], [libsystemd])
+
 PBX_SYSLOG=0
 
 if test "${ac_cv_header_syslog_h}" = "yes"; then
diff --git a/include/asterisk/autoconfig.h.in b/include/asterisk/autoconfig.h.in
index 5e7ea7e2a..e16b66861 100644
--- a/include/asterisk/autoconfig.h.in
+++ b/include/asterisk/autoconfig.h.in
@@ -1027,6 +1027,9 @@
 /* Define to 1 if you have the <syslog.h> header file. */
 #undef HAVE_SYSLOG_H
 
+/* Define if your system has the SYSTEMD libraries. */
+#undef HAVE_SYSTEMD
+
 /* Define to 1 if you have the <sys/dir.h> header file, and it defines `DIR'.
    */
 #undef HAVE_SYS_DIR_H
diff --git a/include/asterisk/io.h b/include/asterisk/io.h
index 2bddd3780..6ee8450bd 100644
--- a/include/asterisk/io.h
+++ b/include/asterisk/io.h
@@ -139,6 +139,16 @@ int ast_restore_tty(int fd, int oldstatus);
 
 int ast_get_termcols(int fd);
 
+/*!
+ * \brief a wrapper for sd_notify(): notify systemd of any state changes.
+ * \param state a string that states the changes. See sd_notify(3).
+ * The wrapper does nothing if systemd ('s development headers) was not
+ * detected on the system.
+ * \returns >=0 on success, negative value on error.
+ */
+int ast_sd_notify(const char *state);
+
+
 #if defined(__cplusplus) || defined(c_plusplus)
 }
 #endif
diff --git a/main/Makefile b/main/Makefile
index a6c3ab1b8..d41302a7f 100644
--- a/main/Makefile
+++ b/main/Makefile
@@ -45,6 +45,7 @@ AST_LIBS+=$(UUID_LIB)
 AST_LIBS+=$(CRYPT_LIB)
 AST_LIBS+=$(AST_CLANG_BLOCKS_LIBS)
 AST_LIBS+=$(RT_LIB)
+AST_LIBS+=$(SYSTEMD_LIB)
 
 ifneq ($(findstring $(OSARCH), linux-gnu uclinux linux-uclibc linux-musl kfreebsd-gnu),)
   ifneq ($(findstring LOADABLE_MODULES,$(MENUSELECT_CFLAGS)),)
diff --git a/main/asterisk.c b/main/asterisk.c
index 3c2ca259e..e2f8901c2 100644
--- a/main/asterisk.c
+++ b/main/asterisk.c
@@ -1999,6 +1999,9 @@ static void really_quit(int num, shutdown_nice_t niceness, int restart)
 		ast_module_shutdown();
 	}
 
+	if (!restart) {
+		ast_sd_notify("STOPPING=1");
+	}
 	if (ast_opt_console || (ast_opt_remote && !ast_opt_exec)) {
 		ast_el_write_default_histfile();
 		if (consolethread == AST_PTHREADT_NULL || consolethread == pthread_self()) {
@@ -4526,6 +4529,7 @@ static void asterisk_daemon(int isroot, const char *runuser, const char *rungrou
 	ast_register_cleanup(main_atexit);
 
 	run_startup_commands();
+	ast_sd_notify("READY=1");
 
 	ast_verb(0, COLORIZE_FMT "\n", COLORIZE(COLOR_BRGREEN, 0, "Asterisk Ready."));
 
diff --git a/main/io.c b/main/io.c
index ff5ca57f7..3441fbae9 100644
--- a/main/io.c
+++ b/main/io.c
@@ -36,6 +36,9 @@ ASTERISK_REGISTER_FILE()
 
 #include "asterisk/io.h"
 #include "asterisk/utils.h"
+#ifdef HAVE_SYSTEMD
+#include <systemd/sd-daemon.h>
+#endif
 
 #ifdef DEBUG_IO
 #define DEBUG DEBUG_M
@@ -384,3 +387,10 @@ int ast_get_termcols(int fd)
 	return cols;
 }
 
+int ast_sd_notify(const char *state) {
+#ifdef HAVE_SYSTEMD
+	return sd_notify(0, state);
+#else
+	return 0;
+#endif
+}
diff --git a/main/loader.c b/main/loader.c
index f95922173..36a3d5f61 100644
--- a/main/loader.c
+++ b/main/loader.c
@@ -891,6 +891,7 @@ enum ast_module_reload_result ast_module_reload(const char *name)
 		res = AST_MODULE_RELOAD_IN_PROGRESS;
 		goto module_reload_exit;
 	}
+	ast_sd_notify("RELOAD=1");
 	ast_lastreloadtime = ast_tvnow();
 
 	if (ast_opt_lock_confdir) {
@@ -904,9 +905,8 @@ enum ast_module_reload_result ast_module_reload(const char *name)
 		}
 		if (res != AST_LOCK_SUCCESS) {
 			ast_log(AST_LOG_WARNING, "Cannot grab lock on %s\n", ast_config_AST_CONFIG_DIR);
-			ast_mutex_unlock(&reloadlock);
 			res = AST_MODULE_RELOAD_ERROR;
-			goto module_reload_exit;
+			goto module_reload_done;
 		}
 	}
 
@@ -923,8 +923,7 @@ enum ast_module_reload_result ast_module_reload(const char *name)
 		if (ast_opt_lock_confdir) {
 			ast_unlock_path(ast_config_AST_CONFIG_DIR);
 		}
-		ast_mutex_unlock(&reloadlock);
-		goto module_reload_exit;
+		goto module_reload_done;
 	}
 
 	AST_DLLIST_LOCK(&module_list);
@@ -966,7 +965,9 @@ enum ast_module_reload_result ast_module_reload(const char *name)
 	if (ast_opt_lock_confdir) {
 		ast_unlock_path(ast_config_AST_CONFIG_DIR);
 	}
+module_reload_done:
 	ast_mutex_unlock(&reloadlock);
+	ast_sd_notify("READY=1");
 
 module_reload_exit:
 	publish_reload_message(name, res);
diff --git a/makeopts.in b/makeopts.in
index 86b7f9d99..b2b394b5f 100644
--- a/makeopts.in
+++ b/makeopts.in
@@ -259,6 +259,10 @@ RT_LIB=@RT_LIB@
 SS7_INCLUDE=@SS7_INCLUDE@
 SS7_LIB=@SS7_LIB@
 
+HAVE_SYSTEMD=@PBX_SYSTEMD@
+SYSTEMD_INCLUDE=@SYSTEMD_INCLUDE@
+SYSTEMD_LIB=@SYSTEMD_LIB@
+
 OPENR2_INCLUDE=@OPENR2_INCLUDE@
 OPENR2_LIB=@OPENR2_LIB@