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
(cherry picked from commit 07b95f7c65b7c083724f1af2b26f93cc22cad58c)

10 files changed, 166 insertions, 6 deletions

diff --git a/CHANGES b/CHANGES
index 897415875..4a866829a 100644
--- a/CHANGES
+++ b/CHANGES
@@ -77,6 +77,12 @@ app_confbridge
     instance, allows a channel to immediately exit the ConfBridge without having
     to wait for a leave announcement to play.
 
+Core
+------------------
+  * 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.
+
 ------------------------------------------------------------------------------
 --- Functionality changes from Asterisk 13.10.0 to Asterisk 13.11.0 ----------
 ------------------------------------------------------------------------------
diff --git a/configure b/configure
index e3c537a16..6f40dcc38 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
@@ -1296,6 +1301,7 @@ infodir
 docdir
 oldincludedir
 includedir
+runstatedir
 localstatedir
 sharedstatedir
 sysconfdir
@@ -1434,7 +1440,9 @@ PYTHONDEV_LIBS
 GMIME_CFLAGS
 GMIME_LIBS
 GTK2_CFLAGS
-GTK2_LIBS'
+GTK2_LIBS
+SYSTEMD_CFLAGS
+SYSTEMD_LIBS'
 
 
 # Initialize some variables set by options.
@@ -1473,6 +1481,7 @@ 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}'
@@ -1725,6 +1734,15 @@ 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=$ac_optarg ;;
+
   -sbindir | --sbindir | --sbindi | --sbind | --sbin | --sbi | --sb)
     ac_prev=sbindir ;;
   -sbindir=* | --sbindir=* | --sbindi=* | --sbind=* | --sbin=* \
@@ -1862,7 +1880,7 @@ fi
 for ac_var in	exec_prefix prefix bindir sbindir libexecdir datarootdir \
 		datadir sysconfdir sharedstatedir localstatedir includedir \
 		oldincludedir docdir infodir htmldir dvidir pdfdir psdir \
-		libdir localedir mandir
+		libdir localedir mandir runstatedir
 do
   eval ac_val=\$$ac_var
   # Remove trailing slashes.
@@ -2015,6 +2033,7 @@ 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]
@@ -2185,6 +2204,10 @@ 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.
@@ -33984,6 +34007,98 @@ 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 1ba86bb7b..521f02a1b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2601,6 +2601,11 @@ 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 337878c4d..0fc13cf53 100644
--- a/include/asterisk/autoconfig.h.in
+++ b/include/asterisk/autoconfig.h.in
@@ -1012,6 +1012,9 @@
 /* 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 13f1c9cf5..e476969c9 100644
--- a/main/Makefile
+++ b/main/Makefile
@@ -44,6 +44,8 @@ AST_LIBS+=$(URIPARSER_LIB)
 AST_LIBS+=$(UUID_LIB)
 AST_LIBS+=$(CRYPT_LIB)
 AST_LIBS+=$(AST_CLANG_BLOCKS_LIBS)
+AST_LIBS+=$(RT_LIB)
+AST_LIBS+=$(SYSTEMD_LIB)
 
 ifneq ($(findstring $(OSARCH), linux-gnu uclinux linux-uclibc kfreebsd-gnu),)
   ifneq ($(findstring LOADABLE_MODULES,$(MENUSELECT_CFLAGS)),)
diff --git a/main/asterisk.c b/main/asterisk.c
index 69f1d7140..9ac9c4619 100644
--- a/main/asterisk.c
+++ b/main/asterisk.c
@@ -2124,6 +2124,9 @@ 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()) {
@@ -4612,6 +4615,7 @@ 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 cd35995ad..c2d2f9dd3 100644
--- a/main/io.c
+++ b/main/io.c
@@ -36,6 +36,9 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 
 #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 f660a624d..85aeb249e 100644
--- a/main/loader.c
+++ b/main/loader.c
@@ -897,6 +897,7 @@ 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) {
@@ -910,9 +911,8 @@ 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;
 		}
 	}
 
@@ -929,8 +929,7 @@ 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);
@@ -972,7 +971,9 @@ 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 9bd523dbc..20cbade3d 100644
--- a/makeopts.in
+++ b/makeopts.in
@@ -254,6 +254,10 @@ RESAMPLE_LIB=@RESAMPLE_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@