Move the bulk of RR processing from MSC into BSC

RR Messages like STATUS, GPRS SUSPEND, HANDOVER COMPLETE/FAIL, ...
should be processed on the BSC side of things, not on the MSC side.

This is among other things required in preparation of intra-BSC
hand-over support in osmo-bsc.

4 files changed, 107 insertions, 118 deletions

diff --git a/openbsc/include/openbsc/gsm_04_08.h b/openbsc/include/openbsc/gsm_04_08.h
index ec6c2c001..2f5aaa98c 100644
--- a/openbsc/include/openbsc/gsm_04_08.h
+++ b/openbsc/include/openbsc/gsm_04_08.h
@@ -69,4 +69,7 @@ struct msgb *gsm48_create_loc_upd_rej(uint8_t cause);
 void gsm48_lchan2chan_desc(struct gsm48_chan_desc *cd,
 			   const struct gsm_lchan *lchan);
 
+void release_security_operation(struct gsm_subscriber_connection *conn);
+void allocate_security_operation(struct gsm_subscriber_connection *conn);
+
 #endif
diff --git a/openbsc/src/libbsc/bsc_api.c b/openbsc/src/libbsc/bsc_api.c
index bb1374776..9d301f002 100644
--- a/openbsc/src/libbsc/bsc_api.c
+++ b/openbsc/src/libbsc/bsc_api.c
@@ -438,24 +438,55 @@ static void handle_classmark_chg(struct gsm_subscriber_connection *conn,
 		/* we must have a classmark3 */
 		if (gh->data[cm2_len+1] != 0x20) {
 			DEBUGPC(DRR, "ERR CM3 TAG\n");
-			return -EINVAL;
+			return;
 		}
 		if (cm2_len > 3) {
 			DEBUGPC(DRR, "CM2 too long!\n");
-			return -EINVAL;
+			return;
 		}
 
 		cm3_len = gh->data[cm2_len+2];
 		cm3 = &gh->data[cm2_len+3];
 		if (cm3_len > 14) {
 			DEBUGPC(DRR, "CM3 len %u too long!\n", cm3_len);
-			return -EINVAL;
+			return;
 		}
 		DEBUGPC(DRR, "CM3(len=%u)\n", cm3_len);
 	}
 	api->classmark_chg(conn, cm2, cm2_len, cm3, cm3_len);
 }
 
+/* Chapter 9.1.16 Handover complete */
+static void handle_rr_ho_compl(struct msgb *msg)
+{
+	struct lchan_signal_data sig;
+	struct gsm48_hdr *gh = msgb_l3(msg);
+
+	DEBUGP(DRR, "HANDOVER COMPLETE cause = %s\n",
+		rr_cause_name(gh->data[0]));
+
+	sig.lchan = msg->lchan;
+	sig.mr = NULL;
+	osmo_signal_dispatch(SS_LCHAN, S_LCHAN_HANDOVER_COMPL, &sig);
+	/* FIXME: release old channel */
+}
+
+/* Chapter 9.1.17 Handover Failure */
+static void handle_rr_ho_fail(struct msgb *msg)
+{
+	struct lchan_signal_data sig;
+	struct gsm48_hdr *gh = msgb_l3(msg);
+
+	DEBUGP(DRR, "HANDOVER FAILED cause = %s\n",
+		rr_cause_name(gh->data[0]));
+
+	sig.lchan = msg->lchan;
+	sig.mr = NULL;
+	osmo_signal_dispatch(SS_LCHAN, S_LCHAN_HANDOVER_FAIL, &sig);
+	/* FIXME: release allocated new channel */
+}
+
+
 static void dispatch_dtap(struct gsm_subscriber_connection *conn,
 			  uint8_t link_id, struct msgb *msg)
 {
@@ -471,12 +502,38 @@ static void dispatch_dtap(struct gsm_subscriber_connection *conn,
 
 	gh = msgb_l3(msg);
 	pdisc = gh->proto_discr & 0x0f;
+
+	/* the idea is to handle all RR messages here, and only hand
+	 * MM/CC/SMS-CP/LCS up to the MSC.  Some messages like PAGING
+	 * RESPONSE or CM SERVICE REQUEST will not be covered here, as
+	 * they are only possible in the first L3 message of each L2
+	 * channel, i.e. 'conn' will not exist and gsm0408_rcvmsg()
+	 * will call api->compl_l3() for it */
 	switch (pdisc) {
 	case GSM48_PDISC_RR:
 		switch (gh->msg_type) {
+		case GSM48_MT_RR_GPRS_SUSP_REQ:
+			DEBUGP(DRR, "GRPS SUSPEND REQUEST\n");
+			break;
+		case GSM48_MT_RR_STATUS:
+			DEBUGP(DRR, "RR STATUS (cause: %s)\n",
+				rr_cause_name(gh->data[0]));
+			break;
+		case GSM48_MT_RR_MEAS_REP:
+			/* This shouldn't actually end up here, as RSL treats
+			* L3 Info of 08.58 MEASUREMENT REPORT different by calling
+			* directly into gsm48_parse_meas_rep */
+			LOGP(LOGL_ERROR, DMEAS, "DIRECT GSM48 MEASUREMENT REPORT ?!? ");
+			break;
+		case GSM48_MT_RR_HANDO_COMPL:
+			handle_rr_ho_compl(msg);
+			break;
+		case GSM48_MT_RR_HANDO_FAIL:
+			handle_rr_ho_fail(msg);
+			break;
 		case GSM48_MT_RR_CIPH_M_COMPL:
 			if (api->cipher_mode_compl)
-				return api->cipher_mode_compl(conn, msg,
+				api->cipher_mode_compl(conn, msg,
 						conn->lchan->encr.alg_id);
 			break;
 		case GSM48_MT_RR_ASS_COMPL:
@@ -498,21 +555,25 @@ static void dispatch_dtap(struct gsm_subscriber_connection *conn,
 						  conn->lchan->encr.alg_id,
 						  chan_mode_to_speech(conn->lchan));
 			}
-			return;
 			break;
 		case GSM48_MT_RR_CLSM_CHG:
 			handle_classmark_chg(conn, msg);
-			return;
 			break;
+		default:
+			/* Normally, a MSC should never receive RR
+			 * messages, but we'd rather forward what we
+			 * don't know than drop it... */
+			LOGP(DRR, LOGL_NOTICE, "BSC: Passing unknown 04.08 "
+			     "RR message type 0x%02x to MSC\n", gh->msg_type);
+			if (api->dtap)
+				api->dtap(conn, link_id, msg);
 		}
 		break;
-	case GSM48_PDISC_MM:
+	default:
+		if (api->dtap)
+			api->dtap(conn, link_id, msg);
 		break;
 	}
-
-	/* default case */
-	if (api->dtap)
-		api->dtap(conn, link_id, msg);
 }
 
 /*! \brief RSL has received a DATA INDICATION with L3 from MS */
diff --git a/openbsc/src/libmsc/gsm_04_08.c b/openbsc/src/libmsc/gsm_04_08.c
index a2a49aa9a..20a2cc502 100644
--- a/openbsc/src/libmsc/gsm_04_08.c
+++ b/openbsc/src/libmsc/gsm_04_08.c
@@ -134,7 +134,7 @@ int gsm48_cc_tx_notify_ss(struct gsm_trans *trans, const char *message)
 	return gsm48_conn_sendmsg(ss_notify, trans->conn, trans);
 }
 
-static void release_security_operation(struct gsm_subscriber_connection *conn)
+void release_security_operation(struct gsm_subscriber_connection *conn)
 {
 	if (!conn->sec_operation)
 		return;
@@ -144,7 +144,7 @@ static void release_security_operation(struct gsm_subscriber_connection *conn)
 	msc_release_connection(conn);
 }
 
-static void allocate_security_operation(struct gsm_subscriber_connection *conn)
+void allocate_security_operation(struct gsm_subscriber_connection *conn)
 {
 	conn->sec_operation = talloc_zero(tall_authciphop_ctx,
 	                                  struct gsm_security_operation);
@@ -1101,29 +1101,6 @@ static int gsm48_rx_rr_pag_resp(struct gsm_subscriber_connection *conn, struct m
 	return rc;
 }
 
-static int gsm48_rx_rr_status(struct msgb *msg)
-{
-	struct gsm48_hdr *gh = msgb_l3(msg);
-
-	DEBUGP(DRR, "STATUS rr_cause = %s\n",
-		rr_cause_name(gh->data[0]));
-
-	return 0;
-}
-
-static int gsm48_rx_rr_meas_rep(struct msgb *msg)
-{
-	struct gsm_meas_rep *meas_rep = lchan_next_meas_rep(msg->lchan);
-
-	/* This shouldn't actually end up here, as RSL treats
-	 * L3 Info of 08.58 MEASUREMENT REPORT different by calling
-	 * directly into gsm48_parse_meas_rep */
-	DEBUGP(DMEAS, "DIRECT GSM48 MEASUREMENT REPORT ?!? ");
-	gsm48_parse_meas_rep(meas_rep, msg);
-
-	return 0;
-}
-
 static int gsm48_rx_rr_app_info(struct gsm_subscriber_connection *conn, struct msgb *msg)
 {
 	struct gsm48_hdr *gh = msgb_l3(msg);
@@ -1141,69 +1118,6 @@ static int gsm48_rx_rr_app_info(struct gsm_subscriber_connection *conn, struct m
 	return db_apdu_blob_store(conn->subscr, apdu_id_flags, apdu_len, apdu_data);
 }
 
-/* Chapter 9.1.10 Ciphering Mode Complete */
-static int gsm48_rx_rr_ciph_m_compl(struct gsm_subscriber_connection *conn, struct msgb *msg)
-{
-	gsm_cbfn *cb;
-	int rc = 0;
-
-	DEBUGP(DRR, "CIPHERING MODE COMPLETE\n");
-
-	/* Safety check */
-	if (!conn->sec_operation) {
-		DEBUGP(DRR, "No authentication/cipher operation in progress !!!\n");
-		return -EIO;
-	}
-
-	/* FIXME: check for MI (if any) */
-
-	/* Call back whatever was in progress (if anything) ... */
-	cb = conn->sec_operation->cb;
-	if (cb) {
-		rc = cb(GSM_HOOK_RR_SECURITY, GSM_SECURITY_SUCCEEDED,
-			NULL, conn, conn->sec_operation->cb_data);
-	}
-
-	/* Complete the operation */
-	release_security_operation(conn);
-
-	return rc;
-}
-
-/* Chapter 9.1.16 Handover complete */
-static int gsm48_rx_rr_ho_compl(struct msgb *msg)
-{
-	struct lchan_signal_data sig;
-	struct gsm48_hdr *gh = msgb_l3(msg);
-
-	DEBUGP(DRR, "HANDOVER COMPLETE cause = %s\n",
-		rr_cause_name(gh->data[0]));
-
-	sig.lchan = msg->lchan;
-	sig.mr = NULL;
-	osmo_signal_dispatch(SS_LCHAN, S_LCHAN_HANDOVER_COMPL, &sig);
-	/* FIXME: release old channel */
-
-	return 0;
-}
-
-/* Chapter 9.1.17 Handover Failure */
-static int gsm48_rx_rr_ho_fail(struct msgb *msg)
-{
-	struct lchan_signal_data sig;
-	struct gsm48_hdr *gh = msgb_l3(msg);
-
-	DEBUGP(DRR, "HANDOVER FAILED cause = %s\n",
-		rr_cause_name(gh->data[0]));
-
-	sig.lchan = msg->lchan;
-	sig.mr = NULL;
-	osmo_signal_dispatch(SS_LCHAN, S_LCHAN_HANDOVER_FAIL, &sig);
-	/* FIXME: release allocated new channel */
-
-	return 0;
-}
-
 /* Receive a GSM 04.08 Radio Resource (RR) message */
 static int gsm0408_rcv_rr(struct gsm_subscriber_connection *conn, struct msgb *msg)
 {
@@ -1211,32 +1125,14 @@ static int gsm0408_rcv_rr(struct gsm_subscriber_connection *conn, struct msgb *m
 	int rc = 0;
 
 	switch (gh->msg_type) {
-	case GSM48_MT_RR_GPRS_SUSP_REQ:
-		DEBUGP(DRR, "GRPS SUSPEND REQUEST\n");
-		break;
 	case GSM48_MT_RR_PAG_RESP:
 		rc = gsm48_rx_rr_pag_resp(conn, msg);
 		break;
-	case GSM48_MT_RR_STATUS:
-		rc = gsm48_rx_rr_status(msg);
-		break;
-	case GSM48_MT_RR_MEAS_REP:
-		rc = gsm48_rx_rr_meas_rep(msg);
-		break;
 	case GSM48_MT_RR_APP_INFO:
 		rc = gsm48_rx_rr_app_info(conn, msg);
 		break;
-	case GSM48_MT_RR_CIPH_M_COMPL:
-		rc = gsm48_rx_rr_ciph_m_compl(conn, msg);
-		break;
-	case GSM48_MT_RR_HANDO_COMPL:
-		rc = gsm48_rx_rr_ho_compl(msg);
-		break;
-	case GSM48_MT_RR_HANDO_FAIL:
-		rc = gsm48_rx_rr_ho_fail(msg);
-		break;
 	default:
-		LOGP(DRR, LOGL_NOTICE, "Unimplemented "
+		LOGP(DRR, LOGL_NOTICE, "MSC: Unimplemented "
 			"GSM 04.08 RR msg type 0x%02x\n", gh->msg_type);
 		break;
 	}
diff --git a/openbsc/src/libmsc/osmo_msc.c b/openbsc/src/libmsc/osmo_msc.c
index 121de679c..4c0862aae 100644
--- a/openbsc/src/libmsc/osmo_msc.c
+++ b/openbsc/src/libmsc/osmo_msc.c
@@ -101,6 +101,34 @@ static void msc_classmark_chg(struct gsm_subscriber_connection *conn,
 	}
 }
 
+static void msc_ciph_m_compl(struct gsm_subscriber_connection *conn,
+			     struct msgb *msg, uint8_t alg_id)
+{
+	gsm_cbfn *cb;
+
+	DEBUGP(DRR, "CIPHERING MODE COMPLETE\n");
+
+	/* Safety check */
+	if (!conn->sec_operation) {
+		DEBUGP(DRR, "No authentication/cipher operation in progress !!!\n");
+		return;
+	}
+
+	/* FIXME: check for MI (if any) */
+
+	/* Call back whatever was in progress (if anything) ... */
+	cb = conn->sec_operation->cb;
+	if (cb) {
+		int rc;
+		rc = cb(GSM_HOOK_RR_SECURITY, GSM_SECURITY_SUCCEEDED,
+			NULL, conn, conn->sec_operation->cb_data);
+
+	}
+
+	/* Complete the operation */
+	release_security_operation(conn);
+}
+
 
 
 static struct bsc_api msc_handler = {
@@ -111,6 +139,7 @@ static struct bsc_api msc_handler = {
 	.assign_compl = msc_assign_compl,
 	.assign_fail = msc_assign_fail,
 	.classmark_chg = msc_classmark_chg,
+	.cipher_mode_compl = msc_ciph_m_compl,
 };
 
 struct bsc_api *msc_bsc_api() {