pespin has uploaded this change for review. (
https://gerrit.osmocom.org/c/osmo-bsc/+/41993?usp=email )
Change subject: Lb: Handle N-PCSTATE.ind
......................................................................
Lb: Handle N-PCSTATE.ind
Change-Id: I16900b9c2b840d4c7d8471c1f69b19601e892b2d
---
M src/osmo-bsc/lb.c
1 file changed, 104 insertions(+), 0 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/osmo-bsc refs/changes/93/41993/1
diff --git a/src/osmo-bsc/lb.c b/src/osmo-bsc/lb.c
index 14e3bd8..a413d2d 100644
--- a/src/osmo-bsc/lb.c
+++ b/src/osmo-bsc/lb.c
@@ -144,6 +144,17 @@
return NULL;
}
+/* Find an SMLC by its remote sigtran point code on a given cs7 instance. */
+static struct smlc_config *get_smlc_by_pc(uint32_t pc)
+{
+ struct smlc_config *smlc = bsc_gsmnet->smlc;
+ if ((smlc->smlc_addr.presence & OSMO_SCCP_ADDR_T_PC) == 0)
+ return NULL;
+ if (smlc->smlc_addr.pc != pc)
+ return NULL;
+ return smlc;
+}
+
static int handle_notice_ind(const struct osmo_scu_notice_param *ni)
{
int rc = 0;
@@ -175,6 +186,95 @@
return rc;
}
+static void handle_pcstate_ind(struct osmo_ss7_instance *cs7, const struct
osmo_scu_pcstate_param *pcst)
+{
+ struct smlc_config *smlc;
+ bool connected;
+ bool disconnected;
+
+ LOGP(DLCS, LOGL_DEBUG, "N-PCSTATE ind: affected_pc=%u=%s sp_status=%s
remote_sccp_status=%s\n",
+ pcst->affected_pc, osmo_ss7_pointcode_print(cs7,
pcst->affected_pc),
+ osmo_sccp_sp_status_name(pcst->sp_status),
+ osmo_sccp_rem_sccp_status_name(pcst->remote_sccp_status));
+
+ /* If we don't care about that point-code, ignore PCSTATE. */
+ smlc = get_smlc_by_pc(pcst->affected_pc);
+ if (!smlc)
+ return;
+
+ /* See if this marks the point code to have become available, or to
have been lost.
+ *
+ * I want to detect two events:
+ * - connection event (both indicators say PC is reachable).
+ * - disconnection event (at least one indicator says the PC is not
reachable).
+ *
+ * There are two separate incoming indicators with various possible
values -- the incoming events can be:
+ *
+ * - neither connection nor disconnection indicated -- just indicating
congestion
+ * connected == false, disconnected == false --> do nothing.
+ * - both incoming values indicate that we are connected
+ * --> trigger connected
+ * - both indicate we are disconnected
+ * --> trigger disconnected
+ * - one value indicates 'connected', the other indicates 'disconnected'
+ * --> trigger disconnected
+ *
+ * Congestion could imply that we're connected, but it does not
indicate that a PC's reachability changed, so no need to
+ * trigger on that.
+ */
+ connected = false;
+ disconnected = false;
+
+ switch (pcst->sp_status) {
+ case OSMO_SCCP_SP_S_ACCESSIBLE:
+ connected = true;
+ break;
+ case OSMO_SCCP_SP_S_INACCESSIBLE:
+ disconnected = true;
+ break;
+ default:
+ case OSMO_SCCP_SP_S_CONGESTED:
+ /* Neither connecting nor disconnecting */
+ break;
+ }
+
+ switch (pcst->remote_sccp_status) {
+ case OSMO_SCCP_REM_SCCP_S_AVAILABLE:
+ if (!disconnected)
+ connected = true;
+ break;
+ case OSMO_SCCP_REM_SCCP_S_UNAVAILABLE_UNKNOWN:
+ case OSMO_SCCP_REM_SCCP_S_UNEQUIPPED:
+ case OSMO_SCCP_REM_SCCP_S_INACCESSIBLE:
+ disconnected = true;
+ connected = false;
+ break;
+ default:
+ case OSMO_SCCP_REM_SCCP_S_CONGESTED:
+ /* Neither connecting nor disconnecting */
+ break;
+ }
+
+ if (disconnected && bssmap_reset_is_conn_ready(smlc->bssmap_reset)) {
+ LOGP(DLCS, LOGL_NOTICE,
+ "now unreachable: N-PCSTATE ind: pc=%u=%s sp_status=%s
remote_sccp_status=%s\n",
+ pcst->affected_pc, osmo_ss7_pointcode_print(cs7,
pcst->affected_pc),
+ osmo_sccp_sp_status_name(pcst->sp_status),
+ osmo_sccp_rem_sccp_status_name(pcst->remote_sccp_status));
+ /* A previously usable MSC has disconnected. Kick the BSSMAP
back to DISC state. */
+ bssmap_reset_set_disconnected(smlc->bssmap_reset);
+ } else if (connected &&
!bssmap_reset_is_conn_ready(smlc->bssmap_reset)) {
+ LOGP(DLCS, LOGL_NOTICE,
+ "now available: N-PCSTATE ind: pc=%u=%s sp_status=%s
remote_sccp_status=%s\n",
+ pcst->affected_pc, osmo_ss7_pointcode_print(cs7,
pcst->affected_pc),
+ osmo_sccp_sp_status_name(pcst->sp_status),
+ osmo_sccp_rem_sccp_status_name(pcst->remote_sccp_status));
+ /* A previously unusable MSC has become reachable. Trigger
immediate BSSMAP RESET -- we would resend a
+ * RESET either way, but we might as well do it now to speed up
connecting. */
+ bssmap_reset_resend_reset(smlc->bssmap_reset);
+ }
+}
+
static int sccp_sap_up(struct osmo_prim_hdr *oph, void *_scu)
{
struct osmo_scu_prim *scu_prim = (struct osmo_scu_prim *)oph;
@@ -257,6 +357,10 @@
}
break;
+ case OSMO_PRIM(OSMO_SCU_PRIM_N_PCSTATE, PRIM_OP_INDICATION):
+ handle_pcstate_ind(osmo_sccp_get_ss7(sccp),
&scu_prim->u.pcstate);
+ break;
+
default:
LOGP(DLCS, LOGL_ERROR, "Unhandled SIGTRAN primitive %s.%s\n",
osmo_scu_prim_type_name(oph->primitive),
--
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Gerrit-MessageType: newchange
Gerrit-Project: osmo-bsc
Gerrit-Branch: master
Gerrit-Change-Id: I16900b9c2b840d4c7d8471c1f69b19601e892b2d
Gerrit-Change-Number: 41993
Gerrit-PatchSet: 1
Gerrit-Owner: pespin <[email protected]>
