[PATCH 5/8] tbf: Move the creation of a new tbf for the downlink to a new method

From: Holger Hans Peter Freyther &lt;holger(a)moiji-mobile.com&gt; Move the code that is dedicated to handle the assignment of a new TFI/TBF for the downlink into a new method. --- src/tbf.cpp | 150 ++++++++++++++++++++++++++++++++---------------------------- 1 file changed, 80 insertions(+), 70 deletions(-) diff --git a/src/tbf.cpp b/src/tbf.cpp index fc8d229..8dad6bc 100644 --- a/src/tbf.cpp +++ b/src/tbf.cpp @@ -102,6 +102,81 @@ static int tbf_append_data(struct gprs_rlcmac_tbf *tbf, return 0; } +static int tbf_new_dl_assignment(struct gprs_rlcmac_bts *bts, + const char *imsi, + const uint32_t tlli, const uint8_t ms_class, + const uint8_t *data, const uint16_t len) +{ + uint8_t trx, ta, ss; + int8_t use_trx; + struct gprs_rlcmac_tbf *old_tbf, *tbf; + int8_t tfi; /* must be signed */ + int rc; + + /* check for uplink data, so we copy our informations */ + tbf = tbf_by_tlli(tlli, GPRS_RLCMAC_UL_TBF); + if (tbf && tbf->dir.ul.contention_resolution_done + && !tbf->dir.ul.final_ack_sent) { + use_trx = tbf->trx; + ta = tbf->ta; + ss = 0; + old_tbf = tbf; + } else { + use_trx = -1; + /* we already have an uplink TBF, so we use that TA */ + if (tbf) + ta = tbf->ta; + else { + /* recall TA */ + rc = recall_timing_advance(tlli); + if (rc < 0) { + LOGP(DRLCMAC, LOGL_NOTICE, "TA unknown" + ", assuming 0\n"); + ta = 0; + } else + ta = rc; + } + ss = 1; /* PCH assignment only allows one timeslot */ + old_tbf = NULL; + } + + // Create new TBF (any TRX) + tfi = tfi_find_free(bts, GPRS_RLCMAC_DL_TBF, &trx, use_trx); + if (tfi < 0) { + LOGP(DRLCMAC, LOGL_NOTICE, "No PDCH resource\n"); + /* FIXME: send reject */ + return -EBUSY; + } + /* set number of downlink slots according to multislot class */ + tbf = tbf_alloc(bts, tbf, GPRS_RLCMAC_DL_TBF, tfi, trx, ms_class, ss); + if (!tbf) { + LOGP(DRLCMAC, LOGL_NOTICE, "No PDCH ressource\n"); + /* FIXME: send reject */ + return -EBUSY; + } + tbf->tlli = tlli; + tbf->tlli_valid = 1; + tbf->ta = ta; + + LOGP(DRLCMAC, LOGL_DEBUG, + "TBF: [DOWNLINK] START TFI: %d TLLI: 0x%08x \n", + tbf->tfi, tbf->tlli); + + /* new TBF, so put first frame */ + memcpy(tbf->llc_frame, data, len); + tbf->llc_length = len; + + /* trigger downlink assignment and set state to ASSIGN. + * we don't use old_downlink, so the possible uplink is used + * to trigger downlink assignment. if there is no uplink, + * AGCH is used. */ + gprs_rlcmac_trigger_downlink_assignment(tbf, old_tbf, imsi); + + /* store IMSI for debugging purpose. TODO: it is more than debugging */ + tbf_assign_imsi(tbf, imsi); + return 0; +} + /** * TODO: split into unit test-able parts... */ @@ -111,81 +186,16 @@ int tbf_handle(struct gprs_rlcmac_bts *bts, const uint8_t *data, const uint16_t len) { struct gprs_rlcmac_tbf *tbf; - int8_t tfi; /* must be signed */ /* check for existing TBF */ tbf = tbf_lookup_dl(tlli, imsi); if (tbf) { int rc = tbf_append_data(tbf, bts, ms_class, delay_csec, data, len); - if (rc < 0) - return rc; - } else { - uint8_t trx, ta, ss; - int8_t use_trx; - struct gprs_rlcmac_tbf *old_tbf; - int rc; - - /* check for uplink data, so we copy our informations */ - tbf = tbf_by_tlli(tlli, GPRS_RLCMAC_UL_TBF); - if (tbf && tbf->dir.ul.contention_resolution_done - && !tbf->dir.ul.final_ack_sent) { - use_trx = tbf->trx; - ta = tbf->ta; - ss = 0; - old_tbf = tbf; - } else { - use_trx = -1; - /* we already have an uplink TBF, so we use that TA */ - if (tbf) - ta = tbf->ta; - else { - /* recall TA */ - rc = recall_timing_advance(tlli); - if (rc < 0) { - LOGP(DRLCMAC, LOGL_NOTICE, "TA unknown" - ", assuming 0\n"); - ta = 0; - } else - ta = rc; - } - ss = 1; /* PCH assignment only allows one timeslot */ - old_tbf = NULL; - } - - // Create new TBF (any TRX) - tfi = tfi_find_free(bts, GPRS_RLCMAC_DL_TBF, &trx, use_trx); - if (tfi < 0) { - LOGP(DRLCMAC, LOGL_NOTICE, "No PDCH resource\n"); - /* FIXME: send reject */ - return -EBUSY; - } - /* set number of downlink slots according to multislot class */ - tbf = tbf_alloc(bts, tbf, GPRS_RLCMAC_DL_TBF, tfi, trx, ms_class, - ss); - if (!tbf) { - LOGP(DRLCMAC, LOGL_NOTICE, "No PDCH ressource\n"); - /* FIXME: send reject */ - return -EBUSY; - } - tbf->tlli = tlli; - tbf->tlli_valid = 1; - tbf->ta = ta; + if (rc >= 0) + tbf_assign_imsi(tbf, imsi); + return rc; + } - LOGP(DRLCMAC, LOGL_DEBUG, "TBF: [DOWNLINK] START TFI: %d TLLI: 0x%08x \n", tbf->tfi, tbf->tlli); - - /* new TBF, so put first frame */ - memcpy(tbf->llc_frame, data, len); - tbf->llc_length = len; - - /* trigger downlink assignment and set state to ASSIGN. - * we don't use old_downlink, so the possible uplink is used - * to trigger downlink assignment. if there is no uplink, - * AGCH is used. */ - gprs_rlcmac_trigger_downlink_assignment(tbf, old_tbf, imsi); - } - - /* store IMSI for debugging purpose. TODO: it is more than debugging */ - tbf_assign_imsi(tbf, imsi); - return 0; + return tbf_new_dl_assignment(bts, imsi, tlli, ms_class, data, len); } -- 1.8.4.rc3