| /* |
| * 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 "bts.h" |
| #include "gprs_debug.h" |
| |
| #include <errno.h> |
| |
| extern "C" { |
| #include <osmocom/core/utils.h> |
| } |
| |
| |
| uint8_t *gprs_rlc_data::prepare(size_t block_data_len) |
| { |
| /* todo.. only set it once if it turns out to be a bottleneck */ |
| memset(block, 0x0, sizeof(block)); |
| memset(block, 0x2b, block_data_len); |
| |
| return block; |
| } |
| |
| void gprs_rlc_data::put_data(const uint8_t *data, size_t data_len) |
| { |
| memcpy(block, data, data_len); |
| len = data_len; |
| } |
| |
| 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() |
| { |
| 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; |
| } |
| |
| static uint16_t bitnum_to_bsn(int bitnum, uint16_t ssn) |
| { |
| return (ssn - 1 - bitnum); |
| } |
| |
| void gprs_rlc_dl_window::update(BTS *bts, const struct bitvec *rbb, |
| uint16_t first_bsn, uint16_t *lost, |
| uint16_t *received) |
| { |
| unsigned num_blocks = 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->rlc_nacked(); |
| *lost += 1; |
| } |
| } |
| } |
| |
| void gprs_rlc_dl_window::update(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->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'; |
| } |
| |
| void gprs_rlc_v_n::reset() |
| { |
| for (size_t i = 0; i < ARRAY_SIZE(m_v_n); ++i) |
| m_v_n[i] = GPRS_RLC_UL_BSN_INVALID; |
| } |
| |
| void gprs_rlc_window::set_sns(uint16_t sns) |
| { |
| OSMO_ASSERT(sns >= RLC_GPRS_SNS); |
| OSMO_ASSERT(sns <= RLC_MAX_SNS); |
| /* check for 2^n */ |
| OSMO_ASSERT((sns & (-sns)) == sns); |
| m_sns = sns; |
| } |
| |
| void gprs_rlc_window::set_ws(uint16_t ws) |
| { |
| OSMO_ASSERT(ws >= RLC_GPRS_SNS/2); |
| OSMO_ASSERT(ws <= RLC_MAX_SNS/2); |
| m_ws = ws; |
| } |
| |
| /* Update the receive block bitmap */ |
| void gprs_rlc_ul_window::update_rbb(char *rbb) |
| { |
| int i; |
| for (i=0; i < ws(); i++) { |
| if (m_v_n.is_received(ssn()-1-i)) |
| rbb[ws()-1-i] = 'R'; |
| else |
| rbb[ws()-1-i] = 'I'; |
| } |
| } |
| |
| /* Raise V(R) to highest received sequence number not received. */ |
| void gprs_rlc_ul_window::raise_v_r(const uint16_t bsn) |
| { |
| uint16_t offset_v_r; |
| offset_v_r = mod_sns(bsn + 1 - v_r()); |
| /* Positive offset, so raise. */ |
| if (offset_v_r < (sns() >> 1)) { |
| while (offset_v_r--) { |
| if (offset_v_r) /* all except the received block */ |
| m_v_n.mark_missing(v_r()); |
| raise_v_r_to(1); |
| } |
| LOGP(DRLCMACUL, LOGL_DEBUG, "- Raising V(R) to %d\n", v_r()); |
| } |
| } |
| |
| /* |
| * Raise V(Q) if possible. This is looped until there is a gap |
| * (non received block) or the window is empty. |
| */ |
| uint16_t gprs_rlc_ul_window::raise_v_q() |
| { |
| uint16_t count = 0; |
| |
| while (v_q() != v_r()) { |
| if (!m_v_n.is_received(v_q())) |
| break; |
| LOGP(DRLCMACUL, LOGL_DEBUG, "- Taking block %d out, raising " |
| "V(Q) to %d\n", v_q(), mod_sns(v_q() + 1)); |
| raise_v_q(1); |
| count += 1; |
| } |
| |
| return count; |
| } |
| |
| void gprs_rlc_ul_window::receive_bsn(const uint16_t bsn) |
| { |
| m_v_n.mark_received(bsn); |
| raise_v_r(bsn); |
| } |
| |
| bool gprs_rlc_ul_window::invalidate_bsn(const uint16_t bsn) |
| { |
| bool was_valid = m_v_n.is_received(bsn); |
| m_v_n.mark_missing(bsn); |
| |
| return was_valid; |
| } |
| |
| static void gprs_rlc_data_header_init(struct gprs_rlc_data_info *rlc, |
| GprsCodingScheme cs, unsigned int header_bits) |
| { |
| unsigned int i; |
| |
| memset(rlc, 0, sizeof(*rlc)); |
| |
| rlc->cs = cs; |
| rlc->num_data_blocks = cs.numDataBlocks(); |
| |
| OSMO_ASSERT(rlc->num_data_blocks <= ARRAY_SIZE(rlc->block_info)); |
| |
| for (i = 0; i < rlc->num_data_blocks; i++) { |
| gprs_rlc_data_block_info_init(&rlc->block_info[i], cs); |
| |
| rlc->data_offs_bits[i] = |
| header_bits + |
| (i+1) * cs.numDataBlockHeaderBits() + |
| i * 8 * rlc->block_info[0].data_len; |
| } |
| } |
| |
| void gprs_rlc_data_info_init_dl(struct gprs_rlc_data_info *rlc, |
| GprsCodingScheme cs) |
| { |
| return gprs_rlc_data_header_init(rlc, cs, cs.numDataHeaderBitsDL()); |
| } |
| |
| void gprs_rlc_data_info_init_ul(struct gprs_rlc_data_info *rlc, |
| GprsCodingScheme cs) |
| { |
| return gprs_rlc_data_header_init(rlc, cs, cs.numDataHeaderBitsUL()); |
| } |
| |
| void gprs_rlc_data_block_info_init(struct gprs_rlc_data_block_info *rdbi, |
| GprsCodingScheme cs) |
| { |
| rdbi->data_len = cs.maxDataBlockBytes(); |
| rdbi->bsn = 0; |
| rdbi->ti = 0; |
| rdbi->e = 1; |
| rdbi->cv = 15; |
| rdbi->pi = 0; |
| rdbi->spb = 0; |
| } |
| |
| unsigned int gprs_rlc_mcs_cps(GprsCodingScheme cs, int punct, int with_padding) |
| { |
| switch (GprsCodingScheme::Scheme(cs)) { |
| case GprsCodingScheme::MCS1: return 0b1011 + punct % 2; |
| case GprsCodingScheme::MCS2: return 0b1001 + punct % 2; |
| case GprsCodingScheme::MCS3: return (with_padding ? 0b0110 : 0b0011) + |
| punct % 3; |
| case GprsCodingScheme::MCS4: return 0b0000 + punct % 3; |
| /* TODO: Add missing MCS */ |
| default: ; |
| } |
| |
| return -1; |
| } |