pcu_l1_if.cpp: handle TLLI based IMMEDIATE ASSIGNMENT confirmation
The IMMEDIATE ASSIGNMENT for downlink TBFs must be confirmed by the
receiving end (BSC/BTS) in order to set the timers in the PCU correctly.
When the PCU is used in a BSC co-located scheme (Ericsson RBS). The TLLI
is used as an identifier to confirm a specific IMMEDIATE ASSIGNMENT.
Change-Id: Icf7ca34500984239ee877ee71fd9c126b5eb3480
Related: OS#5198
diff --git a/src/bts.cpp b/src/bts.cpp
index d06c9d0..33ad4a6 100644
--- a/src/bts.cpp
+++ b/src/bts.cpp
@@ -668,13 +668,10 @@
return best_first_tfi;
}
-int bts_rcv_imm_ass_cnf(struct gprs_rlcmac_bts *bts, const uint8_t *data, uint32_t fn)
+static int tlli_from_imm_ass(uint32_t *tlli, const uint8_t *data, uint32_t fn)
{
- struct gprs_rlcmac_dl_tbf *dl_tbf;
const struct gsm48_imm_ass *imm_ass = (struct gsm48_imm_ass *)data;
uint8_t plen;
- uint32_t tlli;
- GprsMs *ms;
/* Move to IA Rest Octets: TS 44.018 9.1.18 "The L2 pseudo length of
* this message is the sum of lengths of all information elements
@@ -692,12 +689,41 @@
}
/* get TLLI from downlink assignment */
- tlli = (uint32_t)((*data++) & 0xf) << 28;
- tlli |= (*data++) << 20;
- tlli |= (*data++) << 12;
- tlli |= (*data++) << 4;
- tlli |= (*data++) >> 4;
+ *tlli = (uint32_t)((*data++) & 0xf) << 28;
+ *tlli |= (*data++) << 20;
+ *tlli |= (*data++) << 12;
+ *tlli |= (*data++) << 4;
+ *tlli |= (*data++) >> 4;
+ return 0;
+}
+
+int bts_rcv_imm_ass_cnf(struct gprs_rlcmac_bts *bts, const uint8_t *data, uint32_t tlli, uint32_t fn)
+{
+ struct gprs_rlcmac_dl_tbf *dl_tbf;
+ GprsMs *ms;
+ int rc;
+
+ /* NOTE: A confirmation for a downlink IMMEDIATE ASSIGNMENT can be received using two different methods.
+ * One way is to send the whole IMMEDIATE ASSIGNMENT back to the PCU and the TLLI, which we use as
+ * reference is extracted from the rest octets of this message. Alternatively the TLLI may be sent as
+ * confirmation directly. */
+
+ /* Extract TLLI from the presented IMMEDIATE ASSIGNMENT
+ * (if present and only when TLLI that is supplied as function parameter is valid.) */
+ if (data && tlli == GSM_RESERVED_TMSI) {
+ rc = tlli_from_imm_ass(&tlli, data, fn);
+ if (rc != 0)
+ return -EINVAL;
+ }
+
+ /* Make sure TLLI is valid */
+ if (tlli == GSM_RESERVED_TMSI) {
+ LOGP(DTBFDL, LOGL_ERROR, "FN=%u Got IMM.ASS confirm, but TLLI is invalid!\n", fn);
+ return -EINVAL;
+ }
+
+ /* Find related TBF and send confirmation signal to FSM */
ms = bts_ms_by_tlli(bts, tlli, GSM_RESERVED_TMSI);
if (!ms) {
LOGP(DTBFDL, LOGL_ERROR, "FN=%u Got IMM.ASS confirm for unknown MS with TLLI=%08x\n", fn, tlli);
diff --git a/src/bts.h b/src/bts.h
index 61c5e43..5efbdad 100644
--- a/src/bts.h
+++ b/src/bts.h
@@ -315,7 +315,7 @@
int bts_rcv_rach(struct gprs_rlcmac_bts *bts, const struct rach_ind_params *rip);
int bts_rcv_ptcch_rach(struct gprs_rlcmac_bts *bts, const struct rach_ind_params *rip);
-int bts_rcv_imm_ass_cnf(struct gprs_rlcmac_bts *bts, const uint8_t *data, uint32_t fn);
+int bts_rcv_imm_ass_cnf(struct gprs_rlcmac_bts *bts, const uint8_t *data, uint32_t tlli, uint32_t fn);
void bts_send_gsmtap(struct gprs_rlcmac_bts *bts,
enum pcu_gsmtap_category categ, bool uplink, uint8_t trx_no,
diff --git a/src/pcu_l1_if.cpp b/src/pcu_l1_if.cpp
index 69629db..02f56ac 100644
--- a/src/pcu_l1_if.cpp
+++ b/src/pcu_l1_if.cpp
@@ -512,7 +512,7 @@
switch (data_cnf->sapi) {
case PCU_IF_SAPI_PCH:
if (data_cnf->data[2] == GSM48_MT_RR_IMM_ASS)
- bts_rcv_imm_ass_cnf(bts, data_cnf->data, data_cnf->fn);
+ bts_rcv_imm_ass_cnf(bts, data_cnf->data, GSM_RESERVED_TMSI, data_cnf->fn);
break;
default:
LOGP(DL1IF, LOGL_ERROR, "Received PCU data confirm with "
@@ -523,6 +523,26 @@
return rc;
}
+static int pcu_rx_data_cnf_dt(struct gprs_rlcmac_bts *bts, struct gsm_pcu_if_data_cnf_dt *data_cnf_dt)
+{
+ int rc = 0;
+ int current_fn = bts_current_frame_number(bts);
+
+ LOGP(DL1IF, LOGL_DEBUG, "Data confirm received: sapi=%d fn=%d cur_fn=%d\n",
+ data_cnf_dt->sapi, data_cnf_dt->fn, current_fn);
+
+ switch (data_cnf_dt->sapi) {
+ case PCU_IF_SAPI_PCH:
+ bts_rcv_imm_ass_cnf(bts, NULL, data_cnf_dt->tlli, data_cnf_dt->fn);
+ break;
+ default:
+ LOGP(DL1IF, LOGL_ERROR, "Received PCU data confirm with unsupported sapi %d\n", data_cnf_dt->sapi);
+ rc = -EINVAL;
+ }
+
+ return rc;
+}
+
// FIXME: remove this, when changed from c++ to c.
int pcu_rx_rts_req_pdtch(struct gprs_rlcmac_bts *bts, uint8_t trx, uint8_t ts,
uint32_t fn, uint8_t block_nr)
@@ -1133,6 +1153,10 @@
CHECK_IF_MSG_SIZE(pcu_prim_length, pcu_prim->u.data_cnf);
rc = pcu_rx_data_cnf(bts, &pcu_prim->u.data_cnf);
break;
+ case PCU_IF_MSG_DATA_CNF_DT:
+ CHECK_IF_MSG_SIZE(pcu_prim_length, pcu_prim->u.data_cnf_dt);
+ rc = pcu_rx_data_cnf_dt(bts, &pcu_prim->u.data_cnf_dt);
+ break;
case PCU_IF_MSG_RTS_REQ:
CHECK_IF_MSG_SIZE(pcu_prim_length, pcu_prim->u.rts_req);
rc = pcu_rx_rts_req(bts, &pcu_prim->u.rts_req);