diff --git a/src/hlr_sms.c b/src/hlr_sms.c
new file mode 100644
index 0000000..5866afa
--- /dev/null
+++ b/src/hlr_sms.c
@@ -0,0 +1,103 @@
+/* OsmoHLR SMS-over-GSUP routing implementation */
+
+/* Author: Mychaela N. Falconia <falcon@freecalypso.org>, 2023 - however,
+ * Mother Mychaela's contributions are NOT subject to copyright.
+ * No rights reserved, all rights relinquished.
+ *
+ * Based on earlier unmerged work by Vadim Yanitskiy, 2019.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdint.h>
+#include <string.h>
+#include <errno.h>
+
+#include <osmocom/core/talloc.h>
+#include <osmocom/gsm/gsup.h>
+
+#include <osmocom/hlr/hlr.h>
+#include <osmocom/hlr/hlr_sms.h>
+#include <osmocom/hlr/gsup_server.h>
+#include <osmocom/hlr/gsup_router.h>
+#include <osmocom/hlr/logging.h>
+#include <osmocom/hlr/db.h>
+
+/***********************************************************************
+ * core data structures expressing config from VTY
+ ***********************************************************************/
+
+struct hlr_smsc *smsc_find(struct hlr *hlr, const char *name)
+{
+	struct hlr_smsc *smsc;
+
+	llist_for_each_entry(smsc, &hlr->smsc_list, list) {
+		if (!strcmp(smsc->name, name))
+			return smsc;
+	}
+	return NULL;
+}
+
+struct hlr_smsc *smsc_alloc(struct hlr *hlr, const char *name)
+{
+	struct hlr_smsc *smsc = smsc_find(hlr, name);
+	if (smsc)
+		return NULL;
+
+	smsc = talloc_zero(hlr, struct hlr_smsc);
+	smsc->name = talloc_strdup(smsc, name);
+	smsc->hlr = hlr;
+	llist_add_tail(&smsc->list, &hlr->smsc_list);
+
+	return smsc;
+}
+
+void smsc_free(struct hlr_smsc *smsc)
+{
+	llist_del(&smsc->list);
+	talloc_free(smsc);
+}
+
+struct hlr_smsc_route *smsc_route_find(struct hlr *hlr, const char *num_addr)
+{
+	struct hlr_smsc_route *rt;
+
+	llist_for_each_entry(rt, &hlr->smsc_routes, list) {
+		if (!strcmp(rt->num_addr, num_addr))
+			return rt;
+	}
+	return NULL;
+}
+
+struct hlr_smsc_route *smsc_route_alloc(struct hlr *hlr, const char *num_addr,
+					struct hlr_smsc *smsc)
+{
+	struct hlr_smsc_route *rt;
+
+	if (smsc_route_find(hlr, num_addr))
+		return NULL;
+
+	rt = talloc_zero(hlr, struct hlr_smsc_route);
+	rt->num_addr = talloc_strdup(rt, num_addr);
+	rt->smsc = smsc;
+	llist_add_tail(&rt->list, &hlr->smsc_routes);
+
+	return rt;
+}
+
+void smsc_route_free(struct hlr_smsc_route *rt)
+{
+	llist_del(&rt->list);
+	talloc_free(rt);
+}