| /* Copied from gprs_bssgp_pcu.cpp |
| * |
| * Copyright (C) 2012 Ivan Klyuchnikov |
| * Copyright (C) 2013 by Holger Hans Peter Freyther |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version 2 |
| * of the License, or (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| */ |
| |
| #include <tbf.h> |
| #include <gprs_rlcmac.h> |
| #include <gprs_debug.h> |
| |
| extern "C" { |
| #include <osmocom/core/msgb.h> |
| } |
| |
| #include <errno.h> |
| #include <string.h> |
| |
| static struct gprs_rlcmac_tbf *tbf_lookup_dl(const uint32_t tlli, const char *imsi) |
| { |
| /* TODO: look up by IMSI first, then tlli, then old_tlli */ |
| return tbf_by_tlli(tlli, GPRS_RLCMAC_DL_TBF); |
| } |
| |
| static int tbf_append_data(struct gprs_rlcmac_tbf *tbf, |
| struct gprs_rlcmac_bts *bts, |
| const uint8_t ms_class, |
| const uint16_t pdu_delay_csec, |
| const uint8_t *data, const uint16_t len) |
| { |
| LOGP(DRLCMAC, LOGL_INFO, "TBF: APPEND TFI: %u TLLI: 0x%08x\n", tbf->tfi, tbf->tlli); |
| if (tbf->state == GPRS_RLCMAC_WAIT_RELEASE) { |
| LOGP(DRLCMAC, LOGL_DEBUG, "TBF in WAIT RELEASE state " |
| "(T3193), so reuse TBF\n"); |
| memcpy(tbf->llc_frame, data, len); |
| tbf->llc_length = len; |
| /* reset rlc states */ |
| memset(&tbf->dir.dl, 0, sizeof(tbf->dir.dl)); |
| /* keep to flags */ |
| tbf->state_flags &= GPRS_RLCMAC_FLAG_TO_MASK; |
| tbf->state_flags &= ~(1 << GPRS_RLCMAC_FLAG_CCCH); |
| if (!tbf->ms_class && ms_class) |
| tbf->ms_class = ms_class; |
| tbf_update(tbf); |
| gprs_rlcmac_trigger_downlink_assignment(tbf, tbf, NULL); |
| } else { |
| /* the TBF exists, so we must write it in the queue |
| * we prepend lifetime in front of PDU */ |
| struct timeval *tv; |
| struct msgb *llc_msg = msgb_alloc(len + sizeof(*tv), |
| "llc_pdu_queue"); |
| if (!llc_msg) |
| return -ENOMEM; |
| tv = (struct timeval *)msgb_put(llc_msg, sizeof(*tv)); |
| |
| uint16_t delay_csec; |
| if (bts->force_llc_lifetime) |
| delay_csec = bts->force_llc_lifetime; |
| else |
| delay_csec = pdu_delay_csec; |
| /* keep timestap at 0 for infinite delay */ |
| if (delay_csec != 0xffff) { |
| /* calculate timestamp of timeout */ |
| gettimeofday(tv, NULL); |
| tv->tv_usec += (delay_csec % 100) * 10000; |
| tv->tv_sec += delay_csec / 100; |
| if (tv->tv_usec > 999999) { |
| tv->tv_usec -= 1000000; |
| tv->tv_sec++; |
| } |
| } |
| memcpy(msgb_put(llc_msg, len), data, len); |
| msgb_enqueue(&tbf->llc_queue, llc_msg); |
| /* set ms class for updating TBF */ |
| if (!tbf->ms_class && ms_class) |
| tbf->ms_class = ms_class; |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * TODO: split into unit test-able parts... |
| */ |
| int tbf_handle(struct gprs_rlcmac_bts *bts, |
| const uint32_t tlli, const char *imsi, |
| const uint8_t ms_class, const uint16_t delay_csec, |
| 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; |
| |
| 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 */ |
| strncpy(tbf->meas.imsi, imsi, sizeof(tbf->meas.imsi) - 1); |
| return 0; |
| } |