sgsn: Make authorization asynchronous

Currently the authorization of an IMSI is done by checking ACLs
synchronously which is not feasible when the subscriber data has to
be retrieved from an external source.

This patch changes this by using a callback when the information is
available. This is also done when only ACL are checked, in this case
the callback is invoked from within sgsn_auth_request(). The callback
function sgsn_update_subscriber_data calls sgsn_auth_update which
in turn calls either gsm0408_gprs_access_granted or
gsm0408_gprs_access_denied. gsm48_gmm_authorize is extended by a call
to sgsn_auth_request when IMSI and IMEI are available but the
auth_state is unknown.

The change has been successfully tested with single phones (E71 and
IPhone 5c).

Sponsored-by: On-Waves ehf

2 files changed, 25 insertions, 2 deletions

diff --git a/openbsc/include/openbsc/gprs_gmm.h b/openbsc/include/openbsc/gprs_gmm.h
index 0a7c5b355..e22706b84 100644
--- a/openbsc/include/openbsc/gprs_gmm.h
+++ b/openbsc/include/openbsc/gprs_gmm.h
@@ -13,6 +13,8 @@ int gsm48_tx_gsm_deact_pdp_acc(struct sgsn_pdp_ctx *pdp);
 int gsm0408_gprs_rcvmsg(struct msgb *msg, struct gprs_llc_llme *llme);
 int gsm0408_gprs_force_reattach(struct sgsn_mm_ctx *mmctx);
 int gsm0408_gprs_force_reattach_oldmsg(struct msgb *msg);
+void gsm0408_gprs_access_granted(struct sgsn_mm_ctx *mmctx);
+void gsm0408_gprs_access_denied(struct sgsn_mm_ctx *mmctx);
 
 int gprs_gmm_rx_suspend(struct gprs_ra_id *raid, uint32_t tlli);
 int gprs_gmm_rx_resume(struct gprs_ra_id *raid, uint32_t tlli,
diff --git a/openbsc/include/openbsc/gprs_sgsn.h b/openbsc/include/openbsc/gprs_sgsn.h
index af21eaddb..0cb722067 100644
--- a/openbsc/include/openbsc/gprs_sgsn.h
+++ b/openbsc/include/openbsc/gprs_sgsn.h
@@ -54,6 +54,13 @@ enum gprs_t3350_mode {
 	GMM_T3350_MODE_PTMSI_REALL,
 };
 
+/* Authorization/ACL handling */
+enum sgsn_auth_state {
+	SGSN_AUTH_UNKNOWN,
+	SGSN_AUTH_ACCEPTED,
+	SGSN_AUTH_REJECTED
+};
+
 #define MS_RADIO_ACCESS_CAPA
 
 /* According to TS 03.60, Table 5: SGSN MM and PDP Contexts */
@@ -118,7 +125,7 @@ struct sgsn_mm_ctx {
 	 * where mm->T == 3350 => mm->t3350_mode == f(mm->pending_req). Check
 	 * whether one of them can be dropped. */
 
-	int			is_authorized;
+	enum sgsn_auth_state	auth_state;
 };
 
 #define LOGMMCTXP(level, mm, fmt, args...) \
@@ -249,12 +256,17 @@ struct ctrl_handle *sgsn_controlif_setup(struct gsm_network *, uint16_t port);
 int sgsn_ctrl_cmds_install(void);
 
 /*
- * ACL handling
+ * Authorization/ACL handling
  */
 struct imsi_acl_entry {
 	struct llist_head list;
 	char imsi[16+1];
 };
+
+struct sgsn_subscriber_data {
+	enum sgsn_auth_state auth_state;
+};
+
 struct sgsn_config;
 struct sgsn_instance;
 
@@ -262,6 +274,15 @@ void sgsn_auth_init(struct sgsn_instance *sgi);
 struct imsi_acl_entry *sgsn_acl_lookup(const char *imsi, struct sgsn_config *cfg);
 int sgsn_acl_add(const char *imsi, struct sgsn_config *cfg);
 int sgsn_acl_del(const char *imsi, struct sgsn_config *cfg);
+/* Request authorization */
+int sgsn_auth_request(struct sgsn_mm_ctx *mm, struct sgsn_config *cfg);
+enum sgsn_auth_state sgsn_auth_state(struct sgsn_mm_ctx *mm,
+				     struct sgsn_config *cfg);
+void sgsn_auth_update(struct sgsn_mm_ctx *mm, struct sgsn_subscriber_data *sd);
+
+/* Called on subscriber data updates */
+void sgsn_update_subscriber_data(struct sgsn_mm_ctx *mmctx,
+				 struct sgsn_subscriber_data *sd);
 
 int gprs_sndcp_vty_init(void);
 struct sgsn_instance;