gbproxy: Implement IMSI cache
When SGSN pooling is enabled we need to route some responses based on
IMSI back to the correct SGSN, e.g. PAGING_PS_REJECT.
The IMSI cache keeps track of this IMSI <-> NSE(SGSN) mapping.
Change-Id: If0a8d6cc1d63f2fb2c395cc5d4373a915bc2cb87
Related: OS#4951, OS#4472
diff --git a/include/osmocom/sgsn/gb_proxy.h b/include/osmocom/sgsn/gb_proxy.h
index 04a3c4b..d988cae 100644
--- a/include/osmocom/sgsn/gb_proxy.h
+++ b/include/osmocom/sgsn/gb_proxy.h
@@ -8,6 +8,7 @@
#include <osmocom/core/hashtable.h>
#include <osmocom/gsm/gsm23003.h>
#include <osmocom/gsm/gsm23236.h>
+#include <osmocom/gsm/protocol/gsm_23_003.h>
#include <osmocom/gprs/gprs_ns2.h>
#include <osmocom/vty/command.h>
@@ -83,6 +84,14 @@
uint8_t timeout;
} tlli_cache;
+ /* imsi<->nse cache used for PAGING REJECT */
+ struct {
+ DECLARE_HASHTABLE(entries, 10);
+ struct osmo_timer_list timer;
+ /* Time in seconds that the entries should be valid */
+ uint8_t timeout;
+ } imsi_cache;
+
/* List of all SGSNs */
struct llist_head sgsns;
@@ -173,7 +182,7 @@
/* TLLI cache */
struct gbproxy_tlli_cache_entry {
- /* linked to gbproxy_config.tlli_cache */
+ /* linked to gbproxy_config.tlli_cache.entries */
struct hlist_node list;
/* TLLI of the entry */
@@ -184,6 +193,19 @@
struct gbproxy_nse *nse;
};
+/* IMSI cache */
+struct gbproxy_imsi_cache_entry {
+ /* linked to gbproxy_config.imsi_cache.entries */
+ struct hlist_node list;
+
+ /* IMSI of the entry */
+ char imsi[OSMO_IMSI_BUF_SIZE];
+ /* When was this entry last seen */
+ time_t tstamp;
+ /* The SGSN where the request came from */
+ struct gbproxy_nse *nse;
+};
+
/* Convenience logging macros for NSE/BVC */
#define LOGPNSE_CAT(NSE, SUBSYS, LEVEL, FMT, ARGS...) \
LOGP(SUBSYS, LEVEL, "NSE(%05u/%s) " FMT, (NSE)->nsei, \
@@ -251,12 +273,18 @@
struct gbproxy_nse *gbproxy_nse_by_nsei(struct gbproxy_config *cfg, uint16_t nsei, uint32_t flags);
struct gbproxy_nse *gbproxy_nse_by_nsei_or_new(struct gbproxy_config *cfg, uint16_t nsei, bool sgsn_facing);
struct gbproxy_nse *gbproxy_nse_by_tlli(struct gbproxy_config *cfg, uint32_t tlli);
+struct gbproxy_nse *gbproxy_nse_by_imsi(struct gbproxy_config *cfg, const char *imsi);
/* TLLI cache */
void gbproxy_tlli_cache_update(struct gbproxy_nse *nse, uint32_t tlli);
void gbproxy_tlli_cache_remove(struct gbproxy_config *cfg, uint32_t tlli);
int gbproxy_tlli_cache_cleanup(struct gbproxy_config *cfg);
+/* IMSI cache */
+void gbproxy_imsi_cache_update(struct gbproxy_nse *nse, const char *imsi);
+void gbproxy_imsi_cache_remove(struct gbproxy_config *cfg, const char *imsi);
+int gbproxy_imsi_cache_cleanup(struct gbproxy_config *cfg);
+
/* SGSN handling */
struct gbproxy_sgsn *gbproxy_sgsn_alloc(struct gbproxy_config *cfg, uint16_t nsei, const char *name);
void gbproxy_sgsn_free(struct gbproxy_sgsn *sgsn);