ctrl: Fix CTRL TRAP for {msc.X,msc_)connection_status not sent

The tx TRAP callback is triggered through a signal which is never sent in
osmo-bsc code, and never was as far as I can tell going quite far in the
logs.
In the meanwhile, the msc_connection_status was left in favour of
multi-msc msc.X.connection_status CTRL variable, so let's prepre the cb
function to work for that onei too, dropping global variables which may lead
to wrong output in multi-msc environments, and simply use msc->nr==0 for
the old variable "msc_connection_status".

The signal is now triggered in a_reset when the A conn becomes connected
or disconnected. As a result, a user waiting for the disconnect event
may notice that the status may be changed with a noticeable delay, since
the A conn may be reset only due to high layer timeouts after several
repeated failures (T4, BAD_CONNECTION_THRESOLD).

Related: OS#2623
Related: OS#4701
Related: SYS#5046
Change-Id: I645d198e8e1acd0aba09d05cb3ae90443946acf8

1 files changed, 12 insertions, 7 deletions

diff --git a/src/osmo-bsc/osmo_bsc_ctrl.c b/src/osmo-bsc/osmo_bsc_ctrl.c
index 5ebe59789..05bc86c2b 100644
--- a/src/osmo-bsc/osmo_bsc_ctrl.c
+++ b/src/osmo-bsc/osmo_bsc_ctrl.c
@@ -195,7 +195,6 @@ static int get_msc_connection_status(struct ctrl_cmd *cmd, void *data)
 
 /* Backwards compat. */
 CTRL_CMD_DEFINE_RO(msc0_connection_status, "msc_connection_status");
-static int msc_connection_status = 0; /* XXX unused */
 
 static int get_msc0_connection_status(struct ctrl_cmd *cmd, void *data)
 {
@@ -214,13 +213,12 @@ static int msc_connection_status_trap_cb(unsigned int subsys, unsigned int signa
 {
 	struct ctrl_cmd *cmd;
 	struct gsm_network *gsmnet = (struct gsm_network *)handler_data;
+	struct bsc_msc_data *msc = (struct bsc_msc_data *)signal_data;
 
-	if (signal == S_MSC_LOST && msc_connection_status == 1) {
+	if (signal == S_MSC_LOST) {
 		LOGP(DCTRL, LOGL_DEBUG, "MSC connection lost, sending TRAP.\n");
-		msc_connection_status = 0;
-	} else if (signal == S_MSC_CONNECTED && msc_connection_status == 0) {
+	} else if (signal == S_MSC_CONNECTED) {
 		LOGP(DCTRL, LOGL_DEBUG, "MSC connection (re)established, sending TRAP.\n");
-		msc_connection_status = 1;
 	} else {
 		return 0;
 	}
@@ -232,12 +230,19 @@ static int msc_connection_status_trap_cb(unsigned int subsys, unsigned int signa
 	}
 
 	cmd->id = "0";
-	cmd->variable = "msc_connection_status";
+	cmd->variable = talloc_asprintf(cmd, "msc.%d.connection_status", msc->nr);
+	cmd->node = msc;
 
-	get_msc0_connection_status(cmd, NULL);
+	get_msc_connection_status(cmd, NULL);
 
 	ctrl_cmd_send_to_all(gsmnet->ctrl, cmd);
 
+	if (msc->nr == 0) {
+		/* Backwards compat. */
+		cmd->variable = "msc_connection_status";
+		ctrl_cmd_send_to_all(gsmnet->ctrl, cmd);
+	}
+
 	talloc_free(cmd);
 
 	return 0;