1 files changed, 123 insertions, 0 deletions
diff --git a/src/sgsn/apn.c b/src/sgsn/apn.c
new file mode 100644
index 000000000..a89d15866
--- /dev/null
+++ b/src/sgsn/apn.c
@@ -0,0 +1,123 @@
+/* APN contexts */
+
+/* (C) 2009-2015 by Harald Welte <laforge@gnumonks.org>
+ * (C) 2010 by On-Waves
+ * (C) 2019 by sysmocom s.f.m.c. GmbH <info@sysmocom.de>
+ *
+ * All Rights Reserved
+ *
+ * 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 <string.h>
+#include <talloc.h>
+
+#include <osmocom/sgsn/apn.h>
+#include <osmocom/sgsn/sgsn.h>
+
+static struct apn_ctx *sgsn_apn_ctx_alloc(const char *ap_name, const char *imsi_prefix)
+{
+	struct apn_ctx *actx;
+
+	actx = talloc_zero(sgsn, struct apn_ctx);
+	if (!actx)
+		return NULL;
+	actx->name = talloc_strdup(actx, ap_name);
+	actx->imsi_prefix = talloc_strdup(actx, imsi_prefix);
+
+	llist_add_tail(&actx->list, &sgsn->apn_list);
+
+	return actx;
+}
+
+void sgsn_apn_ctx_free(struct apn_ctx *actx)
+{
+	llist_del(&actx->list);
+	talloc_free(actx);
+}
+
+struct apn_ctx *sgsn_apn_ctx_match(const char *name, const char *imsi)
+{
+	struct apn_ctx *actx;
+	struct apn_ctx *found_actx = NULL;
+	size_t imsi_prio = 0;
+	size_t name_prio = 0;
+	size_t name_req_len = strlen(name);
+
+	llist_for_each_entry(actx, &sgsn->apn_list, list) {
+		size_t name_ref_len, imsi_ref_len;
+		const char *name_ref_start, *name_match_start;
+
+		imsi_ref_len = strlen(actx->imsi_prefix);
+		if (strncmp(actx->imsi_prefix, imsi, imsi_ref_len) != 0)
+			continue;
+
+		if (imsi_ref_len < imsi_prio)
+			continue;
+
+		/* IMSI matches */
+
+		name_ref_start = &actx->name[0];
+		if (name_ref_start[0] == '*') {
+			/* Suffix match */
+			name_ref_start += 1;
+			name_ref_len = strlen(name_ref_start);
+			if (name_ref_len > name_req_len)
+				continue;
+		} else {
+			name_ref_len = strlen(name_ref_start);
+			if (name_ref_len != name_req_len)
+				continue;
+		}
+
+		name_match_start = name + (name_req_len - name_ref_len);
+		if (strcasecmp(name_match_start, name_ref_start) != 0)
+			continue;
+
+		/* IMSI and name match */
+
+		if (imsi_ref_len == imsi_prio && name_ref_len < name_prio)
+			/* Lower priority, skip */
+			continue;
+
+		imsi_prio = imsi_ref_len;
+		name_prio = name_ref_len;
+		found_actx = actx;
+	}
+	return found_actx;
+}
+
+struct apn_ctx *sgsn_apn_ctx_by_name(const char *name, const char *imsi_prefix)
+{
+	struct apn_ctx *actx;
+
+	llist_for_each_entry(actx, &sgsn->apn_list, list) {
+		if (strcasecmp(name, actx->name) == 0 &&
+		    strcasecmp(imsi_prefix, actx->imsi_prefix) == 0)
+			return actx;
+	}
+	return NULL;
+}
+
+struct apn_ctx *sgsn_apn_ctx_find_alloc(const char *name, const char *imsi_prefix)
+{
+	struct apn_ctx *actx;
+
+	actx = sgsn_apn_ctx_by_name(name, imsi_prefix);
+	if (!actx)
+		actx = sgsn_apn_ctx_alloc(name, imsi_prefix);
+
+	return actx;
+}