drop IMSI filter and libfilter completely

Filtering by IMSI in osmo-bsc is a legacy use case with questionable
usefulness. Remove.

Do not keep deprecated VTY commands: those could be dangerous, since
(presumably non-existing) users might assume that the filtering would still be
in place. Rather fail to start osmo-bsc for config with an IMSI ACL.

The IMSI filtering did, if present, provide the logging with an IMSI to print
for the bsc_subscriber. TMSIs should have ended up in logging likewise, which
has never been implemented. The proper way to learn the IMSI would be by the
Common Id message from the MSC. Furthermore, the upcoming MSC pooling feature
will extract the mobile identity again, and will hence make sure that both IMSI
and TMSI identities, as available, end up in the bsc_subscriber and will be
logged again.

So long, IMSI ACL, and thanks for all the fish.

Change-Id: I89727af5387e8360362e995fdee959883c37d89a

1 files changed, 0 insertions, 107 deletions

diff --git a/src/osmo-bsc/gsm_08_08.c b/src/osmo-bsc/gsm_08_08.c
index 8a4b1c5fe..030808b06 100644
--- a/src/osmo-bsc/gsm_08_08.c
+++ b/src/osmo-bsc/gsm_08_08.c
@@ -58,70 +58,6 @@ static bool msc_connected(struct gsm_subscriber_connection *conn)
 static bool complete_layer3(struct gsm_subscriber_connection *conn,
 			    struct msgb *msg, struct bsc_msc_data *msc);
 
-static void bsc_maybe_lu_reject(struct gsm_subscriber_connection *conn, int con_type, int cause)
-{
-	struct msgb *msg;
-
-	/* ignore cm service request or such */
-	if (con_type != FLT_CON_TYPE_LU)
-		return;
-
-	msg = gsm48_create_loc_upd_rej(cause);
-	if (!msg) {
-		LOGP(DMM, LOGL_ERROR, "Failed to create msg for LOCATION UPDATING REJECT.\n");
-		return;
-	}
-
-	msg->lchan = conn->lchan;
-	gscon_submit_rsl_dtap(conn, msg, 0, 0);
-}
-
-static int bsc_filter_initial(struct osmo_bsc_data *bsc,
-				struct bsc_msc_data *msc,
-				struct gsm_subscriber_connection *conn,
-				struct msgb *msg, char **imsi, int *con_type,
-				int *lu_cause)
-{
-	struct bsc_filter_request req;
-	struct bsc_filter_reject_cause cause;
-	struct gsm48_hdr *gh = msgb_l3(msg);
-	int rc;
-
-	req.ctx = conn;
-	req.black_list = NULL;
-	req.access_lists = bsc_access_lists();
-	req.local_lst_name = msc->acc_lst_name;
-	req.global_lst_name = conn_get_bts(conn)->network->bsc_data->acc_lst_name;
-	req.bsc_nr = 0;
-
-	rc = bsc_msg_filter_initial(gh, msgb_l3len(msg), &req,
-				con_type, imsi, &cause);
-	*lu_cause = cause.lu_reject_cause;
-	return rc;
-}
-
-static int bsc_filter_data(struct gsm_subscriber_connection *conn,
-				struct msgb *msg, int *lu_cause)
-{
-	struct bsc_filter_request req;
-	struct gsm48_hdr *gh = msgb_l3(msg);
-	struct bsc_filter_reject_cause cause;
-	int rc;
-
-	req.ctx = conn;
-	req.black_list = NULL;
-	req.access_lists = bsc_access_lists();
-	req.local_lst_name = conn->sccp.msc->acc_lst_name;
-	req.global_lst_name = conn_get_bts(conn)->network->bsc_data->acc_lst_name;
-	req.bsc_nr = 0;
-
-	rc = bsc_msg_filter_data(gh, msgb_l3len(msg), &req,
-				&conn->filter_state,
-				&cause);
-	*lu_cause = cause.lu_reject_cause;
-	return rc;
-}
-
 /*! BTS->MSC: tell MSC a SAPI was not established. */
 void bsc_sapi_n_reject(struct gsm_subscriber_connection *conn, int dlci)
 {
@@ -489,22 +425,12 @@ int bsc_scan_bts_msg(struct gsm_subscriber_connection *conn, struct msgb *msg)
 static bool complete_layer3(struct gsm_subscriber_connection *conn,
 			    struct msgb *msg, struct bsc_msc_data *msc)
 {
-	int con_type, rc, lu_cause;
-	char *imsi = NULL;
 	struct msgb *resp;
 	enum bsc_con ret;
 	struct gsm0808_speech_codec_list scl;
 
 	log_set_context(LOG_CTX_BSC_SUBSCR, conn->bsub);
 
-	/* Check the filter */
-	rc = bsc_filter_initial(msc->network->bsc_data, msc, conn, msg,
-				&imsi, &con_type, &lu_cause);
-	if (rc < 0) {
-		bsc_maybe_lu_reject(conn, con_type, lu_cause);
-		goto early_fail;
-	}
-
 	/* allocate resource for a new connection */
 	ret = osmo_bsc_sigtran_new_conn(conn, msc);
 
@@ -517,28 +443,6 @@ static bool complete_layer3(struct gsm_subscriber_connection *conn,
 		goto early_fail;
 	}
 
-	/* TODO: also extract TMSI. We get an IMSI only when an initial L3 Complete comes in that
-	 * contains an IMSI. We filter by IMSI. A TMSI identity is never returned here, see e.g.
-	 * _cr_check_loc_upd() and other similar functions called from bsc_msg_filter_initial(). */
-	if (imsi) {
-		conn->filter_state.imsi = talloc_steal(conn, imsi);
-		if (conn->bsub) {
-			log_set_context(LOG_CTX_BSC_SUBSCR, conn->bsub);
-			/* Already a subscriber on L3 Complete? Should never happen... */
-			if (conn->bsub->imsi[0]
-			    && strcmp(conn->bsub->imsi, imsi))
-				LOGP(DMSC, LOGL_ERROR, "Subscriber's IMSI changes from %s to %s\n",
-				     conn->bsub->imsi, imsi);
-			bsc_subscr_set_imsi(conn->bsub, imsi);
-		} else {
-			conn->bsub = bsc_subscr_find_or_create_by_imsi(msc->network->bsc_subscribers,
-								       imsi);
-			log_set_context(LOG_CTX_BSC_SUBSCR, conn->bsub);
-		}
-		gscon_update_id(conn);
-	}
-	conn->filter_state.con_type = con_type;
-
 	/* check return value, if failed check msg for and send USSD */
 
 	bsc_scan_bts_msg(conn, msg);
@@ -664,8 +568,6 @@ static int handle_cc_setup(struct gsm_subscriber_connection *conn,
 /*! MS->BSC/MSC: Um L3 message. */
 void bsc_dtap(struct gsm_subscriber_connection *conn, uint8_t link_id, struct msgb *msg)
 {
-	int lu_cause;
-
 	log_set_context(LOG_CTX_BSC_SUBSCR, conn->bsub);
 
 	if (!msc_connected(conn))
@@ -680,15 +582,6 @@ void bsc_dtap(struct gsm_subscriber_connection *conn, uint8_t link_id, struct ms
 	if (handle_cc_setup(conn, msg) >= 1)
 		goto done;
 
-	/* Check the filter */
-	if (bsc_filter_data(conn, msg, &lu_cause) < 0) {
-		bsc_maybe_lu_reject(conn,
-					conn->filter_state.con_type,
-					lu_cause);
-		bsc_clear_request(conn, 0);
-		goto done;
-	}
-
 	bsc_scan_bts_msg(conn, msg);
 
 	/* Store link_id in msg->cb */