sgsn: Add functions to handle APN contexts

This commit adds the exported functions apn_ctx_find_alloc,
apn_ctx_free, apn_ctx_by_name, and apn_ctx_match to manage and
retrieve APN to GGSN mappings.

The following VTY commands are added to 'config-sgsn':

 - apn APN ggsn <0-255>
 - apn APN imsi-prefix PREFIX ggsn <0-255>

which maps an APN gateway string to an SGSN id. The SGSN must be
configured in advance. When matching an APN string, entries with a
leading '*' are used for suffix matching, otherwise an exact match is
done.  When a prefix is given, it is matched against the IMSI. If
several entries match, a longer matching IMSI prefix has precedence.
If there are several matching entries with the same PREFIX, the entry
with longest matching APN is returned.

Ticket: OW#1334
Sponsored-by: On-Waves ehf

1 files changed, 6 insertions, 0 deletions

diff --git a/openbsc/include/openbsc/gprs_sgsn.h b/openbsc/include/openbsc/gprs_sgsn.h
index 516b6cda9..b0d7c32b4 100644
--- a/openbsc/include/openbsc/gprs_sgsn.h
+++ b/openbsc/include/openbsc/gprs_sgsn.h
@@ -239,9 +239,15 @@ struct apn_ctx {
 	struct llist_head list;
 	struct sgsn_ggsn_ctx *ggsn;
 	char *name;
+	char *imsi_prefix;
 	char *description;
 };
 
+struct apn_ctx *sgsn_apn_ctx_find_alloc(const char *name, const char *imsi_prefix);
+void sgsn_apn_ctx_free(struct apn_ctx *actx);
+struct apn_ctx *sgsn_apn_ctx_by_name(const char *name, const char *imsi_prefix);
+struct apn_ctx *sgsn_apn_ctx_match(const char *name, const char *imsi_prefix);
+
 extern struct llist_head sgsn_mm_ctxts;
 extern struct llist_head sgsn_ggsn_ctxts;
 extern struct llist_head sgsn_apn_ctxts;