| /* RLC Window (DL TBF), 3GPP TS 44.060 |
| * |
| * Copyright (C) 2013 by Holger Hans Peter Freyther |
| * Copyright (C) 2023 sysmocom - s.f.m.c. GmbH <info@sysmocom.de> |
| * |
| * 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. |
| */ |
| |
| #include "gprs_debug.h" |
| #include "bts.h" |
| #include "rlc_window_dl.h" |
| |
| extern "C" { |
| #include <osmocom/core/utils.h> |
| #include <osmocom/core/bitvec.h> |
| #include <osmocom/core/logging.h> |
| } |
| |
| static uint16_t bitnum_to_bsn(int bitnum, uint16_t ssn) |
| { |
| return (ssn - 1 - bitnum); |
| } |
| |
| void gprs_rlc_v_b::reset() |
| { |
| for (size_t i = 0; i < ARRAY_SIZE(m_v_b); ++i) |
| mark_invalid(i); |
| } |
| |
| void gprs_rlc_dl_window::reset() |
| { |
| m_v_s = 0; |
| m_v_a = 0; |
| m_v_b.reset(); |
| } |
| |
| int gprs_rlc_dl_window::resend_needed() const |
| { |
| for (uint16_t bsn = v_a(); bsn != v_s(); bsn = mod_sns(bsn + 1)) { |
| if (m_v_b.is_nacked(bsn) || m_v_b.is_resend(bsn)) |
| return bsn; |
| } |
| |
| return -1; |
| } |
| |
| int gprs_rlc_dl_window::mark_for_resend() |
| { |
| int resend = 0; |
| |
| for (uint16_t bsn = v_a(); bsn != v_s(); bsn = mod_sns(bsn + 1)) { |
| if (m_v_b.is_unacked(bsn)) { |
| /* mark to be re-send */ |
| m_v_b.mark_resend(bsn); |
| resend += 1; |
| } |
| } |
| |
| return resend; |
| } |
| |
| int gprs_rlc_dl_window::count_unacked() |
| { |
| uint16_t unacked = 0; |
| uint16_t bsn; |
| |
| for (bsn = v_a(); bsn != v_s(); bsn = mod_sns(bsn + 1)) { |
| if (!m_v_b.is_acked(bsn)) |
| unacked += 1; |
| } |
| |
| return unacked; |
| } |
| |
| void gprs_rlc_dl_window::update(struct gprs_rlcmac_bts *bts, const struct bitvec *rbb, |
| uint16_t first_bsn, uint16_t *lost, |
| uint16_t *received) |
| { |
| unsigned dist = distance(); |
| unsigned num_blocks = rbb->cur_bit > dist |
| ? dist : rbb->cur_bit; |
| unsigned bsn; |
| |
| /* first_bsn is in range V(A)..V(S) */ |
| |
| for (unsigned int bitpos = 0; bitpos < num_blocks; bitpos++) { |
| bool is_ack; |
| bsn = mod_sns(first_bsn + bitpos); |
| if (bsn == mod_sns(v_a() - 1)) |
| break; |
| |
| is_ack = bitvec_get_bit_pos(rbb, bitpos) == 1; |
| |
| if (is_ack) { |
| LOGP(DRLCMACDL, LOGL_DEBUG, "- got ack for BSN=%d\n", bsn); |
| if (!m_v_b.is_acked(bsn)) |
| *received += 1; |
| m_v_b.mark_acked(bsn); |
| } else { |
| LOGP(DRLCMACDL, LOGL_DEBUG, "- got NACK for BSN=%d\n", bsn); |
| m_v_b.mark_nacked(bsn); |
| bts_do_rate_ctr_inc(bts, CTR_RLC_NACKED); |
| *lost += 1; |
| } |
| } |
| } |
| |
| void gprs_rlc_dl_window::update(struct gprs_rlcmac_bts *bts, char *show_rbb, uint16_t ssn, |
| uint16_t *lost, uint16_t *received) |
| { |
| /* SSN - 1 is in range V(A)..V(S)-1 */ |
| for (int bitpos = 0; bitpos < ws(); bitpos++) { |
| uint16_t bsn = mod_sns(bitnum_to_bsn(bitpos, ssn)); |
| |
| if (bsn == mod_sns(v_a() - 1)) |
| break; |
| |
| if (show_rbb[ws() - 1 - bitpos] == 'R') { |
| LOGP(DRLCMACDL, LOGL_DEBUG, "- got ack for BSN=%d\n", bsn); |
| if (!m_v_b.is_acked(bsn)) |
| *received += 1; |
| m_v_b.mark_acked(bsn); |
| } else { |
| LOGP(DRLCMACDL, LOGL_DEBUG, "- got NACK for BSN=%d\n", bsn); |
| m_v_b.mark_nacked(bsn); |
| bts_do_rate_ctr_inc(bts, CTR_RLC_NACKED); |
| *lost += 1; |
| } |
| } |
| } |
| |
| int gprs_rlc_dl_window::move_window() |
| { |
| int i; |
| uint16_t bsn; |
| int moved = 0; |
| |
| for (i = 0, bsn = v_a(); bsn != v_s(); i++, bsn = mod_sns(bsn + 1)) { |
| if (m_v_b.is_acked(bsn)) { |
| m_v_b.mark_invalid(bsn); |
| moved += 1; |
| } else |
| break; |
| } |
| |
| return moved; |
| } |
| |
| void gprs_rlc_dl_window::show_state(char *show_v_b) |
| { |
| int i; |
| uint16_t bsn; |
| |
| for (i = 0, bsn = v_a(); bsn != v_s(); i++, bsn = mod_sns(bsn + 1)) { |
| uint16_t index = bsn & mod_sns_half(); |
| switch(m_v_b.get_state(index)) { |
| case GPRS_RLC_DL_BSN_INVALID: |
| show_v_b[i] = 'I'; |
| break; |
| case GPRS_RLC_DL_BSN_ACKED: |
| show_v_b[i] = 'A'; |
| break; |
| case GPRS_RLC_DL_BSN_RESEND: |
| show_v_b[i] = 'X'; |
| break; |
| case GPRS_RLC_DL_BSN_NACKED: |
| show_v_b[i] = 'N'; |
| break; |
| default: |
| show_v_b[i] = '?'; |
| } |
| } |
| show_v_b[i] = '\0'; |
| } |