Use libvlr in libmsc (large refactoring)

Original libvlr code is by Harald Welte <laforge@gnumonks.org>,
polished and tweaked by Neels Hofmeyr <nhofmeyr@sysmocom.de>.

This is a long series of development collapsed in one patch. The original
history may still be available as branch neels/vlr_orig.

TODO: This commit may be split in several smaller changes before merging to
master.

SMS:

The SQL based lookup of SMS for attached subscribers no longer works since the
SQL database no longer has the subscriber data. Replace with a round-robin on
the SMS recipient MSISDNs paired with a VLR subscriber RAM lookup whether the
subscriber is currently attached.

If there are many SMS for not-attached subscribers in the SMS database, this
will become inefficient: a DB hit returns a pending SMS, the RAM lookup will
reveal that the subscriber is not attached, after which the DB is hit for the
next SMS. It would become more efficient e.g. by having an MSISDN based hash
list for the VLR subscribers and by marking non-attached SMS recipients in the
SMS database so that they can be excluded with the SQL query already.

There is a sanity limit to do at most 100 db hits per attempt to find a pending
SMS. So if there are more than 100 stored SMS waiting for their recipients to
actually attach to the MSC, it may take more than one SMS queue trigger to
deliver SMS for subscribers that are actually attached.

This is not very beautiful, but is merely intended to carry us over to a time
when we have a proper separate SMSC entity.

Introduce gsm_subscriber_connection ref-counting in libmsc.

Related: OS#1592

Change-Id: I702ba504ce2de93507312c28eca8d11f09f4ee8b

1 files changed, 6 insertions, 86 deletions

diff --git a/openbsc/include/openbsc/gsm_subscriber.h b/openbsc/include/openbsc/gsm_subscriber.h
index 7e656145a..c65b8a315 100644
--- a/openbsc/include/openbsc/gsm_subscriber.h
+++ b/openbsc/include/openbsc/gsm_subscriber.h
@@ -19,63 +19,8 @@
 
 #define GSM_SUBSCRIBER_NO_EXPIRATION	0x0
 
-struct vty;
-struct sgsn_mm_ctx;
-struct sgsn_subscriber_data;
-
 struct subscr_request;
 
-struct gsm_subscriber_group {
-	struct gsm_network *net;
-
-	int keep_subscr;
-};
-
-struct gsm_equipment {
-	long long unsigned int id;
-	char imei[GSM23003_IMEISV_NUM_DIGITS+1];
-	char name[GSM_NAME_LENGTH];
-
-	struct gsm48_classmark1 classmark1;
-	uint8_t classmark2_len;
-	uint8_t classmark2[3];
-	uint8_t classmark3_len;
-	uint8_t classmark3[14];
-};
-
-struct gsm_subscriber {
-	struct gsm_subscriber_group *group;
-	long long unsigned int id;
-	char imsi[GSM23003_IMSI_MAX_DIGITS+1];
-	uint32_t tmsi;
-	uint16_t lac;
-	char name[GSM_NAME_LENGTH];
-	char extension[GSM_EXTENSION_LENGTH];
-	int authorized;
-	time_t expire_lu;
-
-	/* Don't delete subscribers even if group->keep_subscr is not set */
-	int keep_in_ram;
-
-	/* Temporary field which is not stored in the DB/HLR */
-	uint32_t flags;
-
-	/* Every user can only have one equipment in use at any given
-	 * point in time */
-	struct gsm_equipment equipment;
-
-	/* for internal management */
-	int use_count;
-	struct llist_head entry;
-
-	/* pending requests */
-	int is_paging;
-	struct llist_head requests;
-
-	/* GPRS/SGSN related fields */
-	struct sgsn_subscriber_data *sgsn_data;
-};
-
 enum gsm_subscriber_field {
 	GSM_SUBSCRIBER_IMSI,
 	GSM_SUBSCRIBER_TMSI,
@@ -89,42 +34,17 @@ enum gsm_subscriber_update_reason {
 	GSM_SUBSCRIBER_UPDATE_EQUIPMENT,
 };
 
-struct gsm_subscriber *subscr_get(struct gsm_subscriber *subscr);
-struct gsm_subscriber *subscr_put(struct gsm_subscriber *subscr);
-struct gsm_subscriber *subscr_create_subscriber(struct gsm_subscriber_group *sgrp,
-						const char *imsi);
-struct gsm_subscriber *subscr_get_by_tmsi(struct gsm_subscriber_group *sgrp,
-					  uint32_t tmsi);
-struct gsm_subscriber *subscr_get_by_imsi(struct gsm_subscriber_group *sgrp,
-					  const char *imsi);
-struct gsm_subscriber *subscr_get_by_extension(struct gsm_subscriber_group *sgrp,
-					       const char *ext);
-struct gsm_subscriber *subscr_get_by_id(struct gsm_subscriber_group *sgrp,
-					unsigned long long id);
-struct gsm_subscriber *subscr_get_or_create(struct gsm_subscriber_group *sgrp,
-					const char *imsi);
-int subscr_update(struct gsm_subscriber *s, struct gsm_bts *bts, int reason);
-struct gsm_subscriber *subscr_active_by_tmsi(struct gsm_subscriber_group *sgrp,
-					     uint32_t tmsi);
-struct gsm_subscriber *subscr_active_by_imsi(struct gsm_subscriber_group *sgrp,
-					     const char *imsi);
-
-char *subscr_name(struct gsm_subscriber *subscr);
-
-int subscr_purge_inactive(struct gsm_subscriber_group *sgrp);
-void subscr_update_from_db(struct gsm_subscriber *subscr);
-void subscr_expire(struct gsm_subscriber_group *sgrp);
-int subscr_update_expire_lu(struct gsm_subscriber *subscr, struct gsm_bts *bts);
+int subscr_update(struct vlr_subscr *vsub, struct gsm_bts *bts, int reason);
 
 /*
  * Paging handling with authentication
  */
-struct subscr_request *subscr_request_channel(struct gsm_subscriber *subscr,
-                        int type, gsm_cbfn *cbfn, void *param);
+struct subscr_request *subscr_request_channel(struct vlr_subscr *vsub,
+					      int channel_type,
+					      gsm_cbfn *cbfn, void *param);
 void subscr_remove_request(struct subscr_request *req);
 
-/* internal */
-struct gsm_subscriber *subscr_alloc(void);
-extern struct llist_head active_subscribers;
+int subscr_paging_dispatch(unsigned int hooknum, unsigned int event,
+			   struct msgb *msg, void *data, void *param);
 
 #endif /* _GSM_SUBSCR_H */