USSD: add special 'idle' handler to IUSE for testing

Change-Id: I0d566a60e95ce2da951f22ad47c6155c5b6a338c

doc/manuals/chapters/ussd.adoc

@@ -67,7 +67,9 @@ USSD requests internally.  It features a set of simple handlers, which
 can be assigned to one or more USSD request prefixes:
 
 * `own-msisdn` returns subscriber's MSISDN (if assigned);
-* `own-imsi` returns subscriber's IMSI.
+* `own-imsi` returns subscriber's IMSI;
+* `test-idle` keeps the session idle until the MS terminates it, or
+  the guard timer expires (may be useful for testing).
 
 Additional handlers can be added on request.
 

src/hlr_ussd.c

@@ -379,6 +379,19 @@ static int handle_ussd_own_imsi(struct ss_session *ss,
 	return 0;
 }
 
+/* This handler just keeps the session idle unless the guard timer expires. */
+static int handle_ussd_test_idle(struct ss_session *ss,
+				 const struct osmo_gsup_message *gsup,
+				 const struct ss_request *req)
+{
+	char buf[GSM0480_USSD_7BIT_STRING_LEN + 1];
+	snprintf(buf, sizeof(buf), "Keeping your session idle, it will expire "
+		 "at most in %u seconds.", g_hlr->ncss_guard_timeout);
+	ss->state = OSMO_GSUP_SESSION_STATE_CONTINUE;
+	ss_tx_to_ms_ussd_7bit(ss, req->invoke_id, buf);
+	return 0;
+}
+
 
 static const struct hlr_iuse hlr_iuses[] = {
 	{
@@ -389,6 +402,10 @@ static const struct hlr_iuse hlr_iuses[] = {
 		.name = "own-imsi",
 		.handle_ussd = handle_ussd_own_imsi,
 	},
+	{
+		.name = "test-idle",
+		.handle_ussd = handle_ussd_test_idle,
+	},
 };
 
 const struct hlr_iuse *iuse_find(const char *name)

src/hlr_vty.c

@@ -174,10 +174,11 @@ DEFUN(cfg_hlr_gsup_ipa_name,
 #define UROUTE_STR "Routing Configuration\n"
 #define PREFIX_STR "Prefix-Matching Route\n" "USSD Prefix\n"
 
-#define INT_CHOICE "(own-msisdn|own-imsi)"
+#define INT_CHOICE "(own-msisdn|own-imsi|test-idle)"
 #define INT_STR "Internal USSD Handler\n" \
 		"Respond with subscribers' own MSISDN\n" \
-		"Respond with subscribers' own IMSI\n"
+		"Respond with subscribers' own IMSI\n" \
+		"Keep the session idle (useful for testing)\n"
 
 #define EXT_STR "External USSD Handler\n" \
 		"Name of External USSD Handler (IPA CCM ID)\n"

tests/test_nodes.vty

@@ -51,7 +51,7 @@ OsmoHLR(config-hlr)# list
   database PATH
   euse NAME
   no euse NAME
-  ussd route prefix PREFIX internal (own-msisdn|own-imsi)
+  ussd route prefix PREFIX internal (own-msisdn|own-imsi|test-idle)
   ussd route prefix PREFIX external EUSE
   no ussd route prefix PREFIX
   ussd default-route external EUSE