gprs_gmm: introduce a GMM Attach Request FSM
The old GMM Attach Request handling used a recursive function
which can not handle certain states and is quite complex and hard to
extend.
The new FSM handles such request in a FSM and can be called multiple
times.
Change-Id: I58b9c17be9776a03bb2a5b21e99135cfefc8c912
diff --git a/include/osmocom/sgsn/gprs_sgsn.h b/include/osmocom/sgsn/gprs_sgsn.h
index 6f16dc7..a5ca959 100644
--- a/include/osmocom/sgsn/gprs_sgsn.h
+++ b/include/osmocom/sgsn/gprs_sgsn.h
@@ -4,6 +4,7 @@
#include <stdint.h>
#include <netinet/in.h>
+#include <osmocom/core/fsm.h>
#include <osmocom/core/timer.h>
#include <osmocom/gsm/gsm48.h>
@@ -168,6 +169,15 @@
struct ranap_ue_conn_ctx *ue_ctx;
struct service_info service;
} iu;
+ struct {
+ struct osmo_fsm_inst *fsm;
+
+ /* when a second attach req arrives while in this procedure,
+ * the fsm needs to compare it against old to decide what to do */
+ struct msgb *attach_req;
+ uint32_t id_type;
+ bool auth_reattempt;
+ } gmm_att_req;
/* VLR number */
uint32_t new_sgsn_addr;
/* Authentication Triplet */