Structural reform: Get rid of osmo_bsc_sccp_con

There was always a 1:1 correspondence between gsm_subscriber_connection
and osmo_bsc_sccp_con, so there's really no point in having two separate
dynamically allocated data structures with pointers back and forth and
another linked list around.

Let's merge osmo_bsc_sccp_con into gsm_subscriber_connection for
simplicity.

The resulting code might not be elegant in places, but I've tried to
do only the most simple changes in this patch, while further
simplifications can be done in later subsequent patches.

As a side-effect, this patch also fixes lchan clearing if the MSC
(or the local SCCP provider) hard-disconnects the SCCP connection.

Change-Id: Idd2b733477ee90d24dec369755a00f1c39c93f39

1 files changed, 28 insertions, 32 deletions

diff --git a/src/osmo-bsc/osmo_bsc_bssap.c b/src/osmo-bsc/osmo_bsc_bssap.c
index 0adc001be..83c884c44 100644
--- a/src/osmo-bsc/osmo_bsc_bssap.c
+++ b/src/osmo-bsc/osmo_bsc_bssap.c
@@ -571,19 +571,15 @@ static int bssmap_handle_paging(struct bsc_msc_data *msc,
  * GSM 08.08 § 3.1.9.1 and 3.2.1.21...
  * release our gsm_subscriber_connection and send message
  */
-static int bssmap_handle_clear_command(struct osmo_bsc_sccp_con *conn,
+static int bssmap_handle_clear_command(struct gsm_subscriber_connection *conn,
 				       struct msgb *msg, unsigned int payload_length)
 {
 	struct msgb *resp;
 
 	/* TODO: handle the cause of this package */
 
-	if (conn->conn) {
-		LOGP(DMSC, LOGL_INFO, "Releasing all transactions on %p\n", conn);
-		gsm0808_clear(conn->conn);
-		bsc_subscr_con_free(conn->conn);
-		conn->conn = NULL;
-	}
+	LOGP(DMSC, LOGL_INFO, "Releasing all transactions on %p\n", conn);
+	gsm0808_clear(conn);
 
 	/* generate the clear complete message */
 	resp = gsm0808_create_clear_complete();
@@ -618,7 +614,7 @@ static int bssmap_handle_clear_command(struct osmo_bsc_sccp_con *conn,
  * is supporting. Currently we are doing it in a rather static
  * way by picking one encryption or no encryption.
  */
-static int bssmap_handle_cipher_mode(struct osmo_bsc_sccp_con *conn,
+static int bssmap_handle_cipher_mode(struct gsm_subscriber_connection *conn,
 				     struct msgb *msg, unsigned int payload_length)
 {
 	uint16_t len;
@@ -633,7 +629,7 @@ static int bssmap_handle_cipher_mode(struct osmo_bsc_sccp_con *conn,
 	uint8_t enc_bits_bsc;
 	uint8_t enc_bits_msc;
 
-	if (!conn->conn) {
+	if (!conn) {
 		LOGP(DMSC, LOGL_ERROR, "No lchan/msc_data in cipher mode command.\n");
 		goto reject;
 	}
@@ -663,7 +659,7 @@ static int bssmap_handle_cipher_mode(struct osmo_bsc_sccp_con *conn,
 		goto reject;
 	}
 
-	network = conn_get_bts(conn->conn)->network;
+	network = conn_get_bts(conn)->network;
 	data = TLVP_VAL(&tp, GSM0808_IE_ENCRYPTION_INFORMATION);
 	enc_bits_msc = data[0];
 	enc_key = &data[1];
@@ -692,7 +688,7 @@ static int bssmap_handle_cipher_mode(struct osmo_bsc_sccp_con *conn,
 
 	/* To complete the confusion, gsm0808_cipher_mode again expects the encryption as a number
 	 * from 0 to 7. */
-	if (gsm0808_cipher_mode(conn->conn, network->a5_encryption, enc_key, enc_key_len,
+	if (gsm0808_cipher_mode(conn, network->a5_encryption, enc_key, enc_key_len,
 				include_imeisv)) {
 		reject_cause = GSM0808_CAUSE_PROTOCOL_ERROR_BETWEEN_BSS_AND_MSC;
 		goto reject;
@@ -728,7 +724,7 @@ static inline int mgcp_timeslot_to_port(int multiplex, int timeslot, int base)
  *
  * See §3.2.1.1 for the message type
  */
-static int bssmap_handle_assignm_req(struct osmo_bsc_sccp_con *conn,
+static int bssmap_handle_assignm_req(struct gsm_subscriber_connection *conn,
 				     struct msgb *msg, unsigned int length)
 {
 	struct msgb *resp;
@@ -744,13 +740,13 @@ static int bssmap_handle_assignm_req(struct osmo_bsc_sccp_con *conn,
 	struct gsm0808_speech_codec_list *scl_ptr = NULL;
 	int rc;
 
-	if (!conn->conn) {
+	if (!conn) {
 		LOGP(DMSC, LOGL_ERROR,
 		     "No lchan/msc_data in cipher mode command.\n");
 		return -1;
 	}
 
-	msc = conn->msc;
+	msc = conn->sccp.msc;
 
 	tlv_parse(&tp, gsm0808_att_tlvdef(), msg->l4h + 1, length - 1, 0, 0);
 
@@ -799,7 +795,7 @@ static int bssmap_handle_assignm_req(struct osmo_bsc_sccp_con *conn,
 	}
 
 	/* Decode speech codec list (AoIP) */
-	conn->conn->codec_list_present = false;
+	conn->codec_list_present = false;
 	if (aoip) {
 		/* Check for speech codec list element */
 		if (!TLVP_PRESENT(&tp, GSM0808_IE_SPEECH_CODEC_LIST)) {
@@ -809,7 +805,7 @@ static int bssmap_handle_assignm_req(struct osmo_bsc_sccp_con *conn,
 		}
 
 		/* Decode Speech Codec list */
-		rc = gsm0808_dec_speech_codec_list(&conn->conn->codec_list,
+		rc = gsm0808_dec_speech_codec_list(&conn->codec_list,
 						   TLVP_VAL(&tp, GSM0808_IE_SPEECH_CODEC_LIST),
 						   TLVP_LEN(&tp, GSM0808_IE_SPEECH_CODEC_LIST));
 		if (rc < 0) {
@@ -817,8 +813,8 @@ static int bssmap_handle_assignm_req(struct osmo_bsc_sccp_con *conn,
 			     "Unable to decode speech codec list\n");
 			goto reject;
 		}
-		conn->conn->codec_list_present = true;
-		scl_ptr = &conn->conn->codec_list;
+		conn->codec_list_present = true;
+		scl_ptr = &conn->codec_list;
 	}
 
 	/* Match codec information from the assignment command against the
@@ -856,7 +852,8 @@ static int bssmap_handle_assignm_req(struct osmo_bsc_sccp_con *conn,
 		conn->user_plane.mgcp_ctx = mgcp_assignm_req(msc->network, msc->network->mgw.client,
 								conn, chan_mode, full_rate);
 		if (!conn->user_plane.mgcp_ctx) {
-			LOGP(DMSC, LOGL_ERROR, "MGCP GW failure, rejecting assignment... (id=%i)\n", conn->conn_id);
+			LOGP(DMSC, LOGL_ERROR, "MGCP GW failure, rejecting assignment... (id=%i)\n",
+				conn->sccp.conn_id);
 			goto reject;
 		}
 
@@ -869,7 +866,7 @@ static int bssmap_handle_assignm_req(struct osmo_bsc_sccp_con *conn,
 		 * to sccp-lite. */
 		conn->user_plane.rtp_port = mgcp_timeslot_to_port(multiplex, timeslot, msc->rtp_base);
 		conn->user_plane.rtp_ip = 0;
-		return gsm0808_assign_req(conn->conn, chan_mode, full_rate);
+		return gsm0808_assign_req(conn, chan_mode, full_rate);
 	}
 
 reject:
@@ -917,7 +914,7 @@ static int bssmap_rcvmsg_udt(struct bsc_msc_data *msc,
 	return ret;
 }
 
-static int bssmap_rcvmsg_dt1(struct osmo_bsc_sccp_con *conn,
+static int bssmap_rcvmsg_dt1(struct gsm_subscriber_connection *conn,
 			     struct msgb *msg, unsigned int length)
 {
 	int ret = 0;
@@ -949,7 +946,7 @@ static int bssmap_rcvmsg_dt1(struct osmo_bsc_sccp_con *conn,
 	return ret;
 }
 
-static int dtap_rcvmsg(struct osmo_bsc_sccp_con *conn,
+static int dtap_rcvmsg(struct gsm_subscriber_connection *conn,
 		       struct msgb *msg, unsigned int length)
 {
 	struct dtap_header *header;
@@ -960,7 +957,7 @@ static int dtap_rcvmsg(struct osmo_bsc_sccp_con *conn,
 	LOGP(DMSC, LOGL_DEBUG, "Rx MSC DTAP: %s\n",
 		osmo_hexdump(msg->l3h, length));
 
-	if (!conn->conn) {
+	if (!conn) {
 		LOGP(DMSC, LOGL_ERROR, "No subscriber connection available\n");
 		return -1;
 	}
@@ -992,10 +989,10 @@ static int dtap_rcvmsg(struct osmo_bsc_sccp_con *conn,
 	memcpy(data, msg->l3h + sizeof(*header), length - sizeof(*header));
 
 	/* pass it to the filter for extra actions */
-	rc = bsc_scan_msc_msg(conn->conn, gsm48);
-	dtap_rc = gsm0808_submit_dtap(conn->conn, gsm48, header->link_id, 1);
+	rc = bsc_scan_msc_msg(conn, gsm48);
+	dtap_rc = gsm0808_submit_dtap(conn, gsm48, header->link_id, 1);
 	if (rc == BSS_SEND_USSD)
-		bsc_send_welcome_ussd(conn->conn);
+		bsc_send_welcome_ussd(conn);
 	return dtap_rc;
 }
 
@@ -1029,7 +1026,7 @@ int bsc_handle_udt(struct bsc_msc_data *msc,
 	return 0;
 }
 
-int bsc_handle_dt(struct osmo_bsc_sccp_con *conn,
+int bsc_handle_dt(struct gsm_subscriber_connection *conn,
 		  struct msgb *msg, unsigned int len)
 {
 	if (len < sizeof(struct bssmap_header)) {
@@ -1063,9 +1060,8 @@ int bssmap_send_aoip_ass_compl(struct gsm_lchan *lchan)
 
 	OSMO_ASSERT(lchan->abis_ip.ass_compl.valid);
 	OSMO_ASSERT(conn);
-	OSMO_ASSERT(conn->sccp_con);
 
-	LOGP(DMSC, LOGL_DEBUG, "Sending assignment complete message... (id=%i)\n", conn->sccp_con->conn_id);
+	LOGP(DMSC, LOGL_DEBUG, "Sending assignment complete message... (id=%i)\n", conn->sccp.conn_id);
 
 	/* Extrapolate speech codec from speech mode */
 	gsm0808_speech_codec_from_chan_type(&sc, lchan->abis_ip.ass_compl.speech_mode);
@@ -1075,15 +1071,15 @@ int bssmap_send_aoip_ass_compl(struct gsm_lchan *lchan)
 					lchan->abis_ip.ass_compl.chosen_channel,
 					lchan->abis_ip.ass_compl.encr_alg_id,
 					lchan->abis_ip.ass_compl.speech_mode,
-					&conn->sccp_con->user_plane.aoip_rtp_addr_local,
+					&conn->user_plane.aoip_rtp_addr_local,
 					&sc,
 					NULL);
 
 	if (!resp) {
 		LOGP(DMSC, LOGL_ERROR, "Failed to generate assignment completed message! (id=%i)\n",
-		     conn->sccp_con->conn_id);
+		     conn->sccp.conn_id);
 		return -EINVAL;
 	}
 
-	return osmo_bsc_sigtran_send(conn->sccp_con, resp);
+	return osmo_bsc_sigtran_send(conn, resp);
 }