gtp: Manage queue timers internally
Currently each user (application) of libgtp needs to manage its own
timers in order to call gtp_retrans_timeout() and gtp_retrans() and
maintain retransmit and duplicate queues working correctly. This adds
unnecesary complexity to applications since nowadays, as a libosmocore
user, libgtp can handle this internally in an easy way.
Furthermore, keeping the timers internal to the library allows for
easier extension of features as well as re-implementation of related
code in the future.
Last but not least, it was detected that existing known applications
(osmo-sgsn, osmo-ggsn, sgsnemu) are not using correctly the API, since
they should be updating their timers through gtp_retrans_timeout()
everytime a message is enqueued/transmitted, otherwise they may fire
gtp_retrans() for retransmition too late in some cases.
Related: OS#4178
Change-Id: Ife7cfd66d6356f413263fe5bda9e43091f5c9e98
diff --git a/gtp/gtp.h b/gtp/gtp.h
index f2a4e1d..e03d77d 100644
--- a/gtp/gtp.h
+++ b/gtp/gtp.h
@@ -14,6 +14,7 @@
#include <osmocom/core/utils.h>
#include <osmocom/core/defs.h>
+#include <osmocom/core/timer.h>
#include "pdp.h"
@@ -268,6 +269,8 @@
struct pdp_t pdpa[PDP_MAX]; /* PDP storage */
struct pdp_t *hashtid[PDP_MAX]; /* Hash table for IMSI + NSAPI */
+ struct osmo_timer_list queue_timer; /* internal queue_{req,resp} timer */
+
/* Call back functions */
int (*cb_delete_context) (struct pdp_t *);
int (*cb_create_context_ind) (struct pdp_t *);
@@ -348,8 +351,8 @@
extern int gtp_decaps0(struct gsn_t *gsn);
extern int gtp_decaps1c(struct gsn_t *gsn);
extern int gtp_decaps1u(struct gsn_t *gsn);
-extern int gtp_retrans(struct gsn_t *gsn);
-extern int gtp_retranstimeout(struct gsn_t *gsn, struct timeval *timeout);
+extern int gtp_retrans(struct gsn_t *gsn) OSMO_DEPRECATED("This API is a no-op, libgtp already does the job internally");
+extern int gtp_retranstimeout(struct gsn_t *gsn, struct timeval *timeout) OSMO_DEPRECATED("This API is a no-op and will return a 1 day timeout");
extern int gtp_set_cb_delete_context(struct gsn_t *gsn,
int (*cb_delete_context) (struct pdp_t *