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/Makefile.am b/include/osmocom/sgsn/Makefile.am
index 269cebc..3b563c4 100644
--- a/include/osmocom/sgsn/Makefile.am
+++ b/include/osmocom/sgsn/Makefile.am
@@ -5,6 +5,7 @@
gb_proxy.h \
gprs_gb_parse.h \
gprs_gmm.h \
+ gprs_gmm_attach.h \
gprs_llc.h \
gprs_llc_xid.h \
gprs_sgsn.h \
diff --git a/include/osmocom/sgsn/gprs_gmm.h b/include/osmocom/sgsn/gprs_gmm.h
index d12eaf9..ffcebd3 100644
--- a/include/osmocom/sgsn/gprs_gmm.h
+++ b/include/osmocom/sgsn/gprs_gmm.h
@@ -40,6 +40,8 @@
uint8_t gmm_cause);
int gsm48_tx_gmm_att_ack(struct sgsn_mm_ctx *mm);
+int gprs_gmm_attach_req_ies(struct msgb *a, struct msgb *b);
+
/* TODO: move extract_subscr_* when gsm48_gmm_authorize() got removed */
void extract_subscr_msisdn(struct sgsn_mm_ctx *ctx);
void extract_subscr_hlr(struct sgsn_mm_ctx *ctx);
diff --git a/include/osmocom/sgsn/gprs_gmm_attach.h b/include/osmocom/sgsn/gprs_gmm_attach.h
new file mode 100644
index 0000000..22fbd6f
--- /dev/null
+++ b/include/osmocom/sgsn/gprs_gmm_attach.h
@@ -0,0 +1,37 @@
+#ifndef GPRS_GMM_ATTACH_H
+#define GPRS_GMM_ATTACH_H
+
+#include <osmocom/core/fsm.h>
+
+struct sgsn_mm_ctx;
+
+enum gmm_attach_req_fsm_states {
+ ST_INIT,
+ ST_IDENTIY,
+ ST_RETRIEVE_AUTH,
+ ST_AUTH,
+ ST_ASK_VLR,
+ ST_ACCEPT,
+ ST_REJECT
+};
+
+enum gmm_attach_req_fsm_events {
+ E_ATTACH_REQ_RECV,
+ E_IDEN_RESP_RECV,
+ E_AUTH_RESP_RECV_SUCCESS,
+ E_AUTH_RESP_RECV_RESYNC,
+ E_ATTACH_ACCEPTED,
+ E_ATTACH_ACCEPT_SENT,
+ E_ATTACH_COMPLETE_RECV,
+ E_REJECT,
+ E_VLR_ANSWERED,
+};
+
+#define GMM_DISCARD_MS_WITHOUT_REJECT -1
+
+extern const struct value_string gmm_attach_req_fsm_event_names[];
+extern struct osmo_fsm gmm_attach_req_fsm;
+
+void gmm_att_req_free(struct sgsn_mm_ctx *mm);
+
+#endif // GPRS_GMM_ATTACH_H
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 */