Move struct apn_ctx and APN related definitions to its own file
This allows further shrinking of gprs_sgsn.{c,h} and also being able to
use GSM_APN_LENGTH on different headers easily (needed by follow-up
patch).
Change-Id: Id225ed8b84e1376f4a30f17dd4b153b6b1a6efa8
diff --git a/src/sgsn/apn.c b/src/sgsn/apn.c
new file mode 100644
index 0000000..d6d5372
--- /dev/null
+++ b/src/sgsn/apn.c
@@ -0,0 +1,126 @@
+/* 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>
+
+extern void *tall_sgsn_ctx;
+
+LLIST_HEAD(sgsn_apn_ctxts);
+
+static struct apn_ctx *sgsn_apn_ctx_alloc(const char *ap_name, const char *imsi_prefix)
+{
+ struct apn_ctx *actx;
+
+ actx = talloc_zero(tall_sgsn_ctx, 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_ctxts);
+
+ 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_ctxts, 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_ctxts, 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;
+}