bsc: Add a "IPA PING" to the SCCP CR messages
We want to reduce the background traffic and might set the ping
interval to be in the range of minutes. But this means that if
the TCP connection is frozen several "SCCP CR CM Service Requests"
will be stuck in the send queue without ever being answered. I
could have used the logic of not receiving the "SCCP CC" to close
the connection but instead I am introducing an overload to schedule
the ping as part of the normal SCCP connection establishment.
The VTY write case has been manually verified, I have also looked
at a single trace to see that the SCCP CR and the IPA PING is
transfered in the same ethernet frame.
diff --git a/openbsc/src/osmo-bsc/osmo_bsc_api.c b/openbsc/src/osmo-bsc/osmo_bsc_api.c
index 1751df7..6bda3d4 100644
--- a/openbsc/src/osmo-bsc/osmo_bsc_api.c
+++ b/openbsc/src/osmo-bsc/osmo_bsc_api.c
@@ -157,13 +157,23 @@
static int complete_layer3(struct gsm_subscriber_connection *conn,
struct msgb *msg, struct osmo_msc_data *msc)
{
+ struct timeval tv;
struct msgb *resp;
uint16_t network_code;
uint16_t country_code;
enum bsc_con ret;
+ int send_ping = msc->advanced_ping;
+
+ /* Advanced ping/pong handling */
+ if (osmo_timer_pending(&msc->pong_timer))
+ send_ping = 0;
+ if (msc->ping_timeout == 0)
+ send_ping = 0;
+ if (send_ping && osmo_timer_remaining(&msc->ping_timer, NULL, &tv) == -1)
+ send_ping = 0;
/* allocate resource for a new connection */
- ret = bsc_create_new_connection(conn, msc);
+ ret = bsc_create_new_connection(conn, msc, send_ping);
if (ret != BSC_CON_SUCCESS) {
/* allocation has failed */