fix and re-enable osmo_hlr_subscriber_update_notify()

Send updated subscriber data out to exactly those GSUP clients that match the
last LU operations (depending on each client sending distinct identification).

As this adds logging on DLGSUP, also change adjacent GSUP related logging from
DMAIN to DLGSUP.

Related: OS#2785
Change-Id: I7c317de8329d9a115d072fc61ddb9abc21b7e8d8

1 files changed, 42 insertions, 23 deletions

diff --git a/src/hlr.c b/src/hlr.c
index 26be8d5..78d6c91 100644
--- a/src/hlr.c
+++ b/src/hlr.c
@@ -54,16 +54,15 @@ static int quit = 0;
 void
 osmo_hlr_subscriber_update_notify(struct hlr_subscriber *subscr)
 {
-	/* FIXME: the below code can only be re-enabled after we make sure that an ISD
-	 * is only sent tot the currently serving VLR and/or SGSN (if there are any).
-	 * We cannot blindly flood the entire PLMN with this, as it would create subscriber
-	 * state in every VLR/SGSN out there, even those that have never seen the subscriber.
-	 * See https://osmocom.org/issues/3154 for details. */
-#if 0
         struct osmo_gsup_conn *co;
 
-	if (g_hlr->gs == NULL)
+	if (g_hlr->gs == NULL) {
+		LOGP(DLGSUP, LOGL_DEBUG,
+		     "IMSI %s: NOT Notifying peers of subscriber data change,"
+		     " there is no GSUP server\n",
+		     subscr->imsi);
 		return;
+	}
 
 	llist_for_each_entry(co, &g_hlr->gs->clients, list) {
 		struct osmo_gsup_message gsup = { };
@@ -72,20 +71,50 @@ osmo_hlr_subscriber_update_notify(struct hlr_subscriber *subscr)
 		struct msgb *msg_out;
 		uint8_t *peer;
 		int peer_len;
+		size_t peer_strlen;
+		const char *peer_compare;
 		enum osmo_gsup_cn_domain cn_domain;
 
-		if (co->supports_ps)
+		if (co->supports_ps) {
 			cn_domain = OSMO_GSUP_CN_DOMAIN_PS;
-		else if (co->supports_cs)
+			peer_compare = subscr->sgsn_number;
+		} else if (co->supports_cs) {
 			cn_domain = OSMO_GSUP_CN_DOMAIN_CS;
-		else {
-			/* We have not yet received a location update from this subscriber .*/
+			peer_compare = subscr->vlr_number;
+		} else {
+			/* We have not yet received a location update from this GSUP client.*/
+			continue;
+		}
+
+		peer_len = osmo_gsup_conn_ccm_get(co, &peer, IPAC_IDTAG_SERNR);
+		if (peer_len < 0) {
+			LOGP(DLGSUP, LOGL_ERROR,
+			       "IMSI='%s': cannot get peer name for connection %s:%u\n", subscr->imsi,
+			       co && co->conn && co->conn->server? co->conn->server->addr : "unset",
+			       co && co->conn && co->conn->server? co->conn->server->port : 0);
+			continue;
+		}
+
+		peer_strlen = strnlen((const char*)peer, peer_len);
+		if (strlen(peer_compare) != peer_strlen || strncmp(peer_compare, (const char *)peer, peer_len)) {
+			/* Mismatch. The subscriber is not subscribed with this GSUP client. */
+			/* I hope peer is always nul terminated... */
+			if (peer_strlen < peer_len)
+				LOGP(DLGSUP, LOGL_DEBUG,
+				     "IMSI %s: subscriber change: skipping %s peer %s\n",
+				     subscr->imsi, cn_domain == OSMO_GSUP_CN_DOMAIN_PS ? "PS" : "CS",
+				     osmo_quote_str((char*)peer, -1));
 			continue;
 		}
 
+		LOGP(DLGSUP, LOGL_DEBUG,
+		     "IMSI %s: subscriber change: notifying %s peer %s\n",
+		     subscr->imsi, cn_domain == OSMO_GSUP_CN_DOMAIN_PS ? "PS" : "CS",
+		     osmo_quote_str(peer_compare, -1));
+
 		if (osmo_gsup_create_insert_subscriber_data_msg(&gsup, subscr->imsi, subscr->msisdn, msisdn_enc,
 								sizeof(msisdn_enc), apn, sizeof(apn), cn_domain) != 0) {
-			LOGP(DMAIN, LOGL_ERROR,
+			LOGP(DLGSUP, LOGL_ERROR,
 			       "IMSI='%s': Cannot notify GSUP client; could not create gsup message "
 			       "for %s:%u\n", subscr->imsi,
 			       co && co->conn && co->conn->server? co->conn->server->addr : "unset",
@@ -96,7 +125,7 @@ osmo_hlr_subscriber_update_notify(struct hlr_subscriber *subscr)
 		/* Send ISD to MSC/SGSN */
 		msg_out = msgb_alloc_headroom(1024+16, 16, "GSUP ISD UPDATE");
 		if (msg_out == NULL) {
-			LOGP(DMAIN, LOGL_ERROR,
+			LOGP(DLGSUP, LOGL_ERROR,
 			       "IMSI='%s': Cannot notify GSUP client; could not allocate msg buffer "
 			       "for %s:%u\n", subscr->imsi,
 			       co && co->conn && co->conn->server? co->conn->server->addr : "unset",
@@ -105,15 +134,6 @@ osmo_hlr_subscriber_update_notify(struct hlr_subscriber *subscr)
 		}
 		osmo_gsup_encode(msg_out, &gsup);
 
-		peer_len = osmo_gsup_conn_ccm_get(co, &peer, IPAC_IDTAG_SERNR);
-		if (peer_len < 0) {
-			LOGP(DMAIN, LOGL_ERROR,
-			       "IMSI='%s': cannot get peer name for connection %s:%u\n", subscr->imsi,
-			       co && co->conn && co->conn->server? co->conn->server->addr : "unset",
-			       co && co->conn && co->conn->server? co->conn->server->port : 0);
-			continue;
-		}
-
 		if (osmo_gsup_addr_send(g_hlr->gs, peer, peer_len, msg_out) < 0) {
 			LOGP(DMAIN, LOGL_ERROR,
 			       "IMSI='%s': Cannot notify GSUP client; send operation failed "
@@ -123,7 +143,6 @@ osmo_hlr_subscriber_update_notify(struct hlr_subscriber *subscr)
 			continue;
 		}
 	}
-#endif
 }
 
 /***********************************************************************