ctrl_tcp module (#346)

* ctrl_tcp module

* ua: set a default reason for UA_EVENT_CALL_CLOSED on user hangup

* ctrl_tcp: netstring

* ctrl_tcp: fix typo

* ctrl_tcp: avoid compiler warnings

* ctrl_tcp: fix memory leak

* ctrl_tcp: make linter happy

* ctrl_tcp: make linter happy

* ctrl_tcp: enhance message definition

* ctrl_tcp: work on command error and empty response

* ctrl_tcp: add response message attribute 'ok'

* ctrl_tcp: cleanup

* ctrl_tcp: linter. Fix too wide line

* ctrl_tcp: Fix. remove unused variable

* ctrl_tcp: rename 'netstring-c' folder by 'netstring'

* ctrl_tcp: rename 'netstring.[ch]' by 'tcp_netstring.[ch]'

* ctrl_tcp: reformat 'netstring' code

* ctrl_tcp: move 'netstring_error_str' function to 'netstring' code

* ctrl_tcp: remove cstring README file

* ctrl_tcp: cleanup cstring makefile

* ctrl_tcp: remove makefile and testsuite files from 'netstring'

* ctrl_tcp: move variable decalaration to the beginning of the function

* ctrl_tcp: add copyright headers

1 files changed, 2 insertions, 1 deletions

diff --git a/src/ua.c b/src/ua.c
index 0467e35..e23d392 100644
--- a/src/ua.c
+++ b/src/ua.c
@@ -837,7 +837,8 @@ void ua_hangup(struct ua *ua, struct call *call,
 
 	(void)call_hangup(call, scode, reason);
 
-	ua_event(ua, UA_EVENT_CALL_CLOSED, call, reason);
+	ua_event(ua, UA_EVENT_CALL_CLOSED, call,
+	         reason ? reason : "Connection reset by user");
 
 	mem_deref(call);