osmo-bsc_nat: Implement MSC-side nat of SCCP connection

Change-Id: I8a7d6095b76bd9072b287a4fa2b29cc0537e1a5b

7 files changed, 42 insertions, 16 deletions

diff --git a/openbsc/include/openbsc/bsc_nat_sccp.h b/openbsc/include/openbsc/bsc_nat_sccp.h
index 8d7e52b8c..c16108e4c 100644
--- a/openbsc/include/openbsc/bsc_nat_sccp.h
+++ b/openbsc/include/openbsc/bsc_nat_sccp.h
@@ -79,6 +79,7 @@ struct nat_sccp_connection {
 	struct sccp_source_reference bsc_patched_ref;	/* local ref of the nat to MSC */
 
 	struct sccp_source_reference msc_real_ref;	/* local ref of the MSC to nat */
+	struct sccp_source_reference msc_patched_ref;	/* local ref of the nat to BSC */
 
 	int has_msc_ref;
 
diff --git a/openbsc/src/osmo-bsc_nat/bsc_mgcp_utils.c b/openbsc/src/osmo-bsc_nat/bsc_mgcp_utils.c
index 81bdf4686..1229d5750 100644
--- a/openbsc/src/osmo-bsc_nat/bsc_mgcp_utils.c
+++ b/openbsc/src/osmo-bsc_nat/bsc_mgcp_utils.c
@@ -217,8 +217,8 @@ int bsc_mgcp_assign_patch(struct nat_sccp_connection *con, struct msgb *msg)
 			LOGP(DNAT, LOGL_ERROR,
 			     "Endpoint %d was assigned to 0x%x and now 0x%x\n",
 			     endp,
-			     sccp_src_ref_to_int(&mcon->patched_ref),
-			     sccp_src_ref_to_int(&con->patched_ref));
+			     sccp_src_ref_to_int(&mcon->bsc_patched_ref),
+			     sccp_src_ref_to_int(&con->bsc_patched_ref));
 			bsc_mgcp_dlcx(mcon);
 		}
 	}
@@ -338,8 +338,8 @@ static void remember_pending_dlcx(struct nat_sccp_connection *con, uint32_t tran
 	/* take the endpoint here */
 	endp = &con->mgcp_conf->trunk.endpoints[con->msc_endp];
 
-	stats->remote_ref = con->remote_ref;
-	stats->src_ref = con->patched_ref;
+	stats->remote_ref = con->msc_real_ref;
+	stats->src_ref = con->bsc_patched_ref;
 
 	stats->ci = endp->ci;
 	stats->bts_rtp_port = endp->bts_end.rtp_port;
diff --git a/openbsc/src/osmo-bsc_nat/bsc_nat.c b/openbsc/src/osmo-bsc_nat/bsc_nat.c
index 8bce839be..d153d6183 100644
--- a/openbsc/src/osmo-bsc_nat/bsc_nat.c
+++ b/openbsc/src/osmo-bsc_nat/bsc_nat.c
@@ -298,7 +298,7 @@ static void nat_send_rlsd_bsc(struct nat_sccp_connection *conn)
 	rel->type = SCCP_MSG_TYPE_RLSD;
 	rel->release_cause = SCCP_RELEASE_CAUSE_SCCP_FAILURE;
 	rel->destination_local_reference = conn->bsc_real_ref;
-	rel->source_local_reference = conn->msc_real_ref;
+	rel->source_local_reference = conn->msc_patched_ref;
 
 	bsc_write(conn->bsc, msg, IPAC_PROTO_SCCP);
 }
@@ -502,7 +502,7 @@ static void bsc_send_con_release(struct bsc_connection *bsc,
 
 	nat_send_clrc_bsc(con);
 
-	rlsd = sccp_create_rlsd(&con->msc_real_ref, &con->bsc_real_ref,
+	rlsd = sccp_create_rlsd(&con->msc_patched_ref, &con->bsc_real_ref,
 				SCCP_RELEASE_CAUSE_END_USER_ORIGINATED);
 	if (!rlsd) {
 		LOGP(DNAT, LOGL_ERROR, "Failed to allocate RLSD for the BSC.\n");
@@ -547,7 +547,7 @@ static void bsc_send_con_refuse(struct bsc_connection *bsc,
 		con->filter_state.con_type = FLT_CON_TYPE_LOCAL_REJECT;
 		con->con_local = NAT_CON_END_LOCAL;
 		con->has_msc_ref = 1;
-		con->msc_real_ref = con->bsc_patched_ref;
+		con->msc_real_ref = con->msc_patched_ref;
 
 		/* 1. create a confirmation */
 		cc = sccp_create_cc(&con->msc_real_ref, &con->bsc_real_ref);
diff --git a/openbsc/src/osmo-bsc_nat/bsc_nat_vty.c b/openbsc/src/osmo-bsc_nat/bsc_nat_vty.c
index 20cacdb77..f18098210 100644
--- a/openbsc/src/osmo-bsc_nat/bsc_nat_vty.c
+++ b/openbsc/src/osmo-bsc_nat/bsc_nat_vty.c
@@ -221,12 +221,13 @@ DEFUN(show_sccp, show_sccp_cmd, "show sccp connections",
 	vty_out(vty, "Listing all open SCCP connections%s", VTY_NEWLINE);
 
 	llist_for_each_entry(con, &_nat->sccp_connections, list_entry) {
-		vty_out(vty, "For BSC Nr: %d BSC ref: 0x%x; MUX ref: 0x%x; Network has ref: %d ref: 0x%x MSC/BSC mux: 0x%x/0x%x type: %s%s",
+		vty_out(vty, "For BSC Nr: %d BSC ref: 0x%x; MUX ref: 0x%x; Network has ref: %d ref: 0x%x; MUX ref: 0x%x; MSC/BSC mux: 0x%x/0x%x type: %s%s",
 			con->bsc->cfg ? con->bsc->cfg->nr : -1,
 			sccp_src_ref_to_int(&con->bsc_real_ref),
 			sccp_src_ref_to_int(&con->bsc_patched_ref),
 			con->has_msc_ref,
 			sccp_src_ref_to_int(&con->msc_real_ref),
+			sccp_src_ref_to_int(&con->msc_patched_ref),
 			con->msc_endp, con->bsc_endp,
 			bsc_con_type_to_string(con->filter_state.con_type),
 			VTY_NEWLINE);
diff --git a/openbsc/src/osmo-bsc_nat/bsc_sccp.c b/openbsc/src/osmo-bsc_nat/bsc_sccp.c
index b5da6e353..26b3cefbd 100644
--- a/openbsc/src/osmo-bsc_nat/bsc_sccp.c
+++ b/openbsc/src/osmo-bsc_nat/bsc_sccp.c
@@ -43,10 +43,12 @@ static int equal(struct sccp_source_reference *ref1, struct sccp_source_referenc
 static int sccp_ref_is_free(struct sccp_source_reference *ref, struct bsc_nat *nat)
 {
 	struct nat_sccp_connection *conn;
-
+#warning "We could have two lists - one for msc and one for bsc side..."
 	llist_for_each_entry(conn, &nat->sccp_connections, list_entry) {
 		if (equal(ref, &conn->bsc_patched_ref))
 			return -1;
+		if (memcmp(ref, &conn->msc_patched_ref, sizeof(*ref)) == 0)
+			return -1;
 	}
 
 	return 0;
@@ -103,6 +105,12 @@ struct nat_sccp_connection *create_sccp_src_ref(struct bsc_connection *bsc,
 			llist_del(&conn->list_entry);
 			talloc_free(conn);
 			return NULL;
+		}
+		if (assign_src_local_reference(&conn->msc_patched_ref, bsc->nat) != 0) {
+			bsc_mgcp_dlcx(conn);
+			llist_del(&conn->list_entry);
+			talloc_free(conn);
+			return NULL;
 		} else {
 			clock_gettime(CLOCK_MONOTONIC, &conn->creation_time);
 			bsc_mgcp_dlcx(conn);
@@ -126,6 +134,12 @@ struct nat_sccp_connection *create_sccp_src_ref(struct bsc_connection *bsc,
 		return NULL;
 	}
 
+	if (assign_src_local_reference(&conn->msc_patched_ref, bsc->nat) != 0) {
+		LOGP(DNAT, LOGL_ERROR, "Failed to assign a ref.\n");
+		talloc_free(conn);
+		return NULL;
+	}
+
 	bsc_mgcp_init(conn);
 	llist_add_tail(&conn->list_entry, &bsc->nat->sccp_connections);
 	rate_ctr_inc(&bsc->cfg->stats.ctrg->ctr[BCFG_CTR_SCCP_CONN]);
@@ -147,6 +161,7 @@ int update_sccp_src_ref(struct nat_sccp_connection *sccp, struct bsc_nat_parsed
 
 	sccp->msc_real_ref = *parsed->src_local_ref;
 	sccp->has_msc_ref = 1;
+	*parsed->src_local_ref = sccp->msc_patched_ref;
 	LOGP(DNAT, LOGL_DEBUG, "Updating 0x%x to remote 0x%x on %p\n",
 	     sccp_src_ref_to_int(&sccp->bsc_patched_ref),
 	     sccp_src_ref_to_int(&sccp->msc_real_ref), sccp->bsc);
@@ -192,6 +207,8 @@ struct nat_sccp_connection *patch_sccp_src_ref_to_bsc(struct msgb *msg,
 
 		/* Change the dest address to the real one */
 		*parsed->dest_local_ref = conn->bsc_real_ref;
+		if (parsed->src_local_ref && conn->has_msc_ref)
+			*parsed->src_local_ref = conn->msc_patched_ref;
 		return conn;
 	}
 
@@ -215,15 +232,21 @@ struct nat_sccp_connection *patch_sccp_src_ref_to_msc(struct msgb *msg,
 	llist_for_each_entry(conn, &bsc->nat->sccp_connections, list_entry) {
 		if (conn->bsc != bsc)
 			continue;
-
+#warning "Do we need to patch the other ref in these ifs as well?"
 		if (parsed->src_local_ref) {
 			if (equal(parsed->src_local_ref, &conn->bsc_real_ref)) {
 				*parsed->src_local_ref = conn->bsc_patched_ref;
+				if (parsed->dest_local_ref)
+					*parsed->dest_local_ref = conn->msc_real_ref;
 				return conn;
 			}
 		} else if (parsed->dest_local_ref) {
-			if (equal(parsed->dest_local_ref, &conn->msc_real_ref))
+			if (equal(parsed->dest_local_ref, &conn->msc_patched_ref)) {
+				*parsed->dest_local_ref = conn->msc_real_ref;
+				if (parsed->src_local_ref)
+					*parsed->src_local_ref = conn->bsc_patched_ref;
 				return conn;
+			}
 		} else {
 			LOGP(DNAT, LOGL_ERROR, "Header has neither loc/dst ref.\n");
 			return NULL;
diff --git a/openbsc/src/osmo-bsc_nat/bsc_ussd.c b/openbsc/src/osmo-bsc_nat/bsc_ussd.c
index 0ba63270d..7a96232f0 100644
--- a/openbsc/src/osmo-bsc_nat/bsc_ussd.c
+++ b/openbsc/src/osmo-bsc_nat/bsc_ussd.c
@@ -348,8 +348,9 @@ static int forward_ussd(struct nat_sccp_connection *con, const struct ussd_reque
 	state = (struct ipac_msgt_sccp_state *) msgb_put(msg, sizeof(*state));
 	state->trans_id = req->transaction_id;
 	state->invoke_id = req->invoke_id;
-	memcpy(&state->src_ref, &con->remote_ref, sizeof(con->remote_ref));
-	memcpy(&state->dst_ref, &con->real_ref, sizeof(con->real_ref));
+#warning "Check if msc_real_ref should be used here"
+	memcpy(&state->src_ref, &con->msc_real_ref, sizeof(con->msc_real_ref));
+	memcpy(&state->dst_ref, &con->bsc_real_ref, sizeof(con->bsc_real_ref));
 	memcpy(state->imsi, con->filter_state.imsi, strlen(con->filter_state.imsi));
 
 	/* add additional tag/values */
diff --git a/openbsc/tests/bsc-nat/bsc_nat_test.c b/openbsc/tests/bsc-nat/bsc_nat_test.c
index 15666387f..869553095 100644
--- a/openbsc/tests/bsc-nat/bsc_nat_test.c
+++ b/openbsc/tests/bsc-nat/bsc_nat_test.c
@@ -330,7 +330,7 @@ static void test_contrack()
 	con_found = patch_sccp_src_ref_to_msc(msg, parsed, con);
 	if (con_found != NULL) {
 		printf("Con should not exist realref(%u)\n",
-		       sccp_src_ref_to_int(&con_found->real_ref));
+		       sccp_src_ref_to_int(&con_found->bsc_real_ref));
 		abort();
 	}
 	rc_con = create_sccp_src_ref(con, parsed);
@@ -412,8 +412,8 @@ static void test_contrack()
 
 	/* verify that it is gone */
 	if (con_found != NULL) {
-		printf("Con should not exist real_ref(%u)\n",
-		       sccp_src_ref_to_int(&con_found->real_ref));
+		printf("Con should not exist bsc_real_ref(%u)\n",
+		       sccp_src_ref_to_int(&con_found->bsc_real_ref));
 		abort();
 	}
 	talloc_free(parsed);