Stasis application WebSocket support

This is the API that binds the Stasis dialplan application to external
Stasis applications. It also adds the beginnings of WebSocket
application support.

This module registers a dialplan function named Stasis, which is used
to put a channel into the named Stasis app. As a channel enters and
leaves the Stasis diaplan application, the Stasis app receives a
'stasis-start' and 'stasis-end' events.

Stasis apps register themselves using the stasis_app_register and
stasis_app_unregister functions. Messages are sent to an application
using stasis_app_send.

Finally, Stasis apps control channels through the use of the
stasis_app_control object, and the family of stasis_app_control_*
functions.

Other changes along for the ride are:
 * An ast_frame_dtor function that's RAII_VAR safe
 * Some common JSON encoders for name/number, timeval, and
   context/extension/priority

Review: https://reviewboard.asterisk.org/r/2361/


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@384879 65c4cc65-6c06-0410-ace0-fbb531ad65f3

main/frame.c

@@ -351,6 +351,13 @@ void ast_frame_free(struct ast_frame *frame, int cache)
 	}
 }
 
+void ast_frame_dtor(struct ast_frame *f)
+{
+	if (f) {
+		ast_frfree(f);
+	}
+}
+
 /*!
  * \brief 'isolates' a frame by duplicating non-malloc'ed components
  * (header, src, data).

main/json.c

@@ -27,6 +27,7 @@
  */
 
 /*** MODULEINFO
+	<depend>jansson</depend>
 	<support_level>core</support_level>
  ***/
 
@@ -35,10 +36,12 @@
 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 
 #include "asterisk/json.h"
+#include "asterisk/localtime.h"
 #include "asterisk/module.h"
 #include "asterisk/utils.h"
 
 #include <jansson.h>
+#include <time.h>
 
 /*!
  * \brief Function wrapper around ast_malloc macro.
@@ -501,6 +504,37 @@ struct ast_json *ast_json_deep_copy(const struct ast_json *value)
 	return (struct ast_json *)json_deep_copy((json_t *)value);
 }
 
+struct ast_json *ast_json_name_number(const char *name, const char *number)
+{
+	return ast_json_pack("{s: s, s: s}",
+			     "name", name,
+			     "number", number);
+}
+
+struct ast_json *ast_json_dialplan_cep(const char *context, const char *exten, int priority)
+{
+	return ast_json_pack("{s: o, s: o, s: o}",
+			     "context", context ? ast_json_string_create(context) : ast_json_null(),
+			     "exten", exten ? ast_json_string_create(exten) : ast_json_null(),
+			     "priority", priority != -1 ? ast_json_integer_create(priority) : ast_json_null());
+}
+
+struct ast_json *ast_json_timeval(const struct timeval *tv, const char *zone)
+{
+	char buf[AST_ISO8601_LEN];
+	struct ast_tm tm = {};
+
+	if (tv == NULL) {
+		return NULL;
+	}
+
+	ast_localtime(tv, &tm, zone);
+
+	ast_strftime(buf, sizeof(buf),AST_ISO8601_FORMAT, &tm);
+
+	return ast_json_string_create(buf);
+}
+
 void ast_json_init(void)
 {
 	/* Setup to use Asterisk custom allocators */