sndcp: Update n201_u & n201_i indicatd by LLC layer

Change-Id: I7429701ae49c2a694dcad3e3d5ec639ab9927f5b
---
M include/osmocom/gprs/sndcp/sndcp_private.h
M src/sndcp/sndcp.c
M src/sndcp/sndcp_prim.c
3 files changed, 32 insertions(+), 6 deletions(-)

diff --git a/include/osmocom/gprs/sndcp/sndcp_private.h b/include/osmocom/gprs/sndcp/sndcp_private.h
index 43ea7ca..21c6a40 100644
--- a/include/osmocom/gprs/sndcp/sndcp_private.h
+++ b/include/osmocom/gprs/sndcp/sndcp_private.h
@@ -171,7 +171,6 @@
 	 * originated XID-Request from peer. NULL if not existing (and l3xid_req_len = 0) */
 	struct llist_head *l3_xid_comp_fields_req_from_peer;
 
-	/* TODO: taken from lle.params and not yet set ever in code! */
 	uint16_t n201_u;
 	uint16_t n201_i;
 };
@@ -220,8 +219,12 @@
 int gprs_sndcp_sne_submit_snsm_activate_rsp(struct gprs_sndcp_entity *sne);
 int gprs_sndcp_sne_handle_llc_ll_unitdata_ind(struct gprs_sndcp_entity *sne,
 					  struct sndcp_common_hdr *sch, uint16_t len);
-int gprs_sndcp_snme_handle_llc_ll_xid_ind(struct gprs_sndcp_mgmt_entity *snme, uint32_t sapi, uint8_t *l3params, unsigned int l3params_len);
-int gprs_sndcp_snme_handle_llc_ll_xid_cnf(struct gprs_sndcp_mgmt_entity *snme, uint32_t sapi, uint8_t *l3params, unsigned int l3params_len);
+int gprs_sndcp_snme_handle_llc_ll_xid_ind(struct gprs_sndcp_mgmt_entity *snme, uint32_t sapi,
+					  uint16_t n201_u, uint16_t n201_i,
+					  uint8_t *l3params, unsigned int l3params_len);
+int gprs_sndcp_snme_handle_llc_ll_xid_cnf(struct gprs_sndcp_mgmt_entity *snme, uint32_t sapi,
+					  uint16_t n201_u, uint16_t n201_i,
+					  uint8_t *l3params, unsigned int l3params_len);
 int gprs_sndcp_sne_handle_sn_unitdata_req(struct gprs_sndcp_entity *sne, uint8_t *npdu, unsigned int npdu_len);
 int gprs_sndcp_sne_handle_sn_xid_req(struct gprs_sndcp_entity *sne, const struct osmo_gprs_sndcp_prim *sndcp_prim);
 int gprs_sndcp_sne_handle_sn_xid_rsp(struct gprs_sndcp_entity *sne, const struct osmo_gprs_sndcp_prim *sndcp_prim);
diff --git a/src/sndcp/sndcp.c b/src/sndcp/sndcp.c
index 4b54be3..5decfac 100644
--- a/src/sndcp/sndcp.c
+++ b/src/sndcp/sndcp.c
@@ -979,7 +979,9 @@
 }
 
 /* 5.1.2.10 SN-XID.indication */
-int gprs_sndcp_snme_handle_llc_ll_xid_ind(struct gprs_sndcp_mgmt_entity *snme, uint32_t sapi, uint8_t *l3params, unsigned int l3params_len)
+int gprs_sndcp_snme_handle_llc_ll_xid_ind(struct gprs_sndcp_mgmt_entity *snme, uint32_t sapi,
+					  uint16_t n201_u, uint16_t n201_i,
+					  uint8_t *l3params, unsigned int l3params_len)
 {
 	int rc;
 	int compclass;
@@ -1005,10 +1007,15 @@
 		return -EINVAL;
 	}
 
+	sne->n201_u = n201_u;
+	sne->n201_i = n201_i;
+
 	/* Some phones send zero byte length SNDCP frames
 	 * and do require a confirmation response. */
 	if (l3params_len == 0) {
-		/* TODO: send empty (len=0) SN-XID.response? */
+		/* TS 44.065 6.8: "If the SNDCP entity receives an LL-XID.indication without
+		 * an SNDCP XID block, it shall not respond with the LL-XID.response primitive."
+		 */
 		return 0;
 	}
 
@@ -1057,7 +1064,9 @@
 /* 5.1.2.12 SN-XID.confirm
  * (See also: TS 144 065, Section 6.8 XID parameter negotiation)
  */
-int gprs_sndcp_snme_handle_llc_ll_xid_cnf(struct gprs_sndcp_mgmt_entity *snme, uint32_t sapi, uint8_t *l3params, unsigned int l3params_len)
+int gprs_sndcp_snme_handle_llc_ll_xid_cnf(struct gprs_sndcp_mgmt_entity *snme, uint32_t sapi,
+					  uint16_t n201_u, uint16_t n201_i,
+					  uint8_t *l3params, unsigned int l3params_len)
 {
 	/* Note: This function handles an incoming SNDCP-XID confirmation.
 	 * Since the confirmation fields may lack important parameters we
@@ -1092,6 +1101,9 @@
 		return -EINVAL;
 	}
 
+	sne->n201_u = n201_u;
+	sne->n201_i = n201_i;
+
 	if (sne->l3xid_req && sne->l3xid_req_len > 0) {
 		/* Parse SNDCP-CID XID-Field */
 		comp_fields_req = gprs_sndcp_parse_xid(NULL, sne, sne->l3xid_req, sne->l3xid_req_len, NULL);
diff --git a/src/sndcp/sndcp_prim.c b/src/sndcp/sndcp_prim.c
index 80dff8f..e371416 100644
--- a/src/sndcp/sndcp_prim.c
+++ b/src/sndcp/sndcp_prim.c
@@ -514,6 +514,7 @@
 	}
 
 	rc = gprs_sndcp_snme_handle_llc_ll_xid_ind(snme, llc_prim->ll.sapi,
+						   llc_prim->ll.xid.n201_u, llc_prim->ll.xid.n201_i,
 						   llc_prim->ll.l3_pdu, llc_prim->ll.l3_pdu_len);
 	return rc;
 }
@@ -532,6 +533,7 @@
 	}
 
 	rc = gprs_sndcp_snme_handle_llc_ll_xid_cnf(snme, llc_prim->ll.sapi,
+						   llc_prim->ll.xid.n201_u, llc_prim->ll.xid.n201_i,
 						   llc_prim->ll.l3_pdu, llc_prim->ll.l3_pdu_len);
 	return rc;
 }

