| /* rlc header descriptions |
| * |
| * Copyright (C) 2012 Ivan Klyuchnikov |
| * Copyright (C) 2012 Andreas Eversberg <jolly@eversberg.eu> |
| * |
| * 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. |
| */ |
| #pragma once |
| |
| #include "gprs_coding_scheme.h" |
| |
| #include <osmocom/core/endian.h> |
| |
| #include <stdint.h> |
| #include <string.h> |
| |
| #define RLC_GPRS_SNS 128 /* GPRS, must be power of 2 */ |
| #define RLC_GPRS_WS 64 /* max window size */ |
| #define RLC_EGPRS_MIN_WS 64 /* min window size */ |
| #define RLC_EGPRS_MAX_WS 1024 /* min window size */ |
| #define RLC_EGPRS_SNS 2048 /* EGPRS, must be power of 2 */ |
| #define RLC_EGPRS_MAX_BSN_DELTA 512 |
| #define RLC_MAX_SNS RLC_EGPRS_SNS |
| #define RLC_MAX_WS RLC_EGPRS_MAX_WS |
| #define RLC_MAX_LEN 74 /* MCS-9 data unit */ |
| |
| struct BTS; |
| |
| /* The state of a BSN in the send/receive window */ |
| enum gprs_rlc_ul_bsn_state { |
| GPRS_RLC_UL_BSN_INVALID, |
| GPRS_RLC_UL_BSN_RECEIVED, |
| GPRS_RLC_UL_BSN_MISSING, |
| GPRS_RLC_UL_BSN_MAX, |
| }; |
| |
| enum gprs_rlc_dl_bsn_state { |
| GPRS_RLC_DL_BSN_INVALID, |
| GPRS_RLC_DL_BSN_NACKED, |
| GPRS_RLC_DL_BSN_ACKED, |
| GPRS_RLC_DL_BSN_UNACKED, |
| GPRS_RLC_DL_BSN_RESEND, |
| GPRS_RLC_DL_BSN_MAX, |
| }; |
| |
| /* |
| * EGPRS resegment status information for UL |
| * When only first split block is received bsn state |
| * will be set to EGPRS_RESEG_FIRST_SEG_RXD and when |
| * only second segment is received the state will be |
| * set to EGPRS_RESEG_SECOND_SEG_RXD. When both Split |
| * blocks are received the state will be set to |
| * EGPRS_RESEG_DEFAULT |
| * The EGPRS resegmentation feature allows MS to retransmit |
| * RLC blocks of HeaderType1, HeaderType2 by segmenting |
| * them to 2 HeaderType3 blocks(Example MCS5 will be |
| * retransmitted as 2 MCS2 blocks). Table 10.4.8b.1 of 44.060 |
| * explains the possible values of SPB in HeadrType3 for UL |
| * direction. When the MCS is changed at the PCU, PCU directs the |
| * changed MCS to MS by PUAN or UPLINK ASSIGNMENT message along |
| * with RESEGMENT flag, Then MS may decide to retransmit the |
| * blocks by resegmenting it based on Table 8.1.1.1 of 44.060. |
| * The retransmission MCS is calculated based on current MCS of |
| * the Block and demanded MCS by PCU. Section 10.3a.4.3 of 44.060 |
| * shows the HeadrType3 with SPB field present in it |
| */ |
| enum egprs_rlc_ul_reseg_bsn_state { |
| EGPRS_RESEG_DEFAULT = 0, |
| EGPRS_RESEG_FIRST_SEG_RXD = 0x01, |
| EGPRS_RESEG_SECOND_SEG_RXD = 0x02, |
| EGPRS_RESEG_INVALID = 0x04 |
| }; |
| |
| /* |
| * EGPRS resegment status information for DL |
| * When only first segment is sent, bsn state |
| * will be set to EGPRS_RESEG_FIRST_SEG_SENT and when |
| * second segment is sent the state will be |
| * set to EGPRS_RESEG_SECOND_SEG_SENT. |
| * EGPRS_RESEG_DL_INVALID is set to 8 considering there is a scope for |
| * 3rd segment according to Table 10.4.8b.2 of 44.060 |
| * The EGPRS resegmentation feature allows PCU to retransmit |
| * RLC blocks of HeaderType1, HeaderType2 by segmenting |
| * them to 2 HeaderType3 blocks(Example MCS5 will be |
| * retransmitted as 2 MCS2 blocks). Table 10.4.8b.2 of 44.060 |
| * explains the possible values of SPB in HeadrType3 for DL |
| * direction.The PCU decides to retransmit the |
| * blocks by resegmenting it based on Table 8.1.1.1 of 44.060. |
| * The retransmission MCS is calculated based on current MCS of |
| * the Block and demanded MCS by PCU. Section 10.3a.3.3 of 44.060 |
| * shows the HeadrType3 with SPB field present in it |
| */ |
| enum egprs_rlc_dl_reseg_bsn_state { |
| EGPRS_RESEG_DL_DEFAULT = 0, |
| EGPRS_RESEG_FIRST_SEG_SENT = 0x01, |
| EGPRS_RESEG_SECOND_SEG_SENT = 0x02, |
| EGPRS_RESEG_DL_INVALID = 0x08 |
| }; |
| |
| /* Table 10.4.8b.2 of 44.060 */ |
| enum egprs_rlcmac_dl_spb { |
| EGPRS_RLCMAC_DL_NO_RETX = 0, |
| EGPRS_RLCMAC_DL_FIRST_SEG = 2, |
| EGPRS_RLCMAC_DL_SEC_SEG = 3, |
| }; |
| |
| /* |
| * Valid puncturing scheme values |
| * TS 44.060 10.4.8a.3.1, 10.4.8a.2.1, 10.4.8a.1.1 |
| */ |
| enum egprs_puncturing_values { |
| EGPRS_PS_1, |
| EGPRS_PS_2, |
| EGPRS_PS_3, |
| EGPRS_PS_INVALID, |
| }; |
| |
| /* |
| * EGPRS_MAX_PS_NUM_2 is valid for MCS 1,2,5,6. |
| * And EGPRS_MAX_PS_NUM_3 is valid for MCS 3,4,7,8,9 |
| * TS 44.060 10.4.8a.3.1, 10.4.8a.2.1, 10.4.8a.1.1 |
| */ |
| enum egprs_puncturing_types { |
| EGPRS_MAX_PS_NUM_2 = 2, |
| EGPRS_MAX_PS_NUM_3, |
| EGPRS_MAX_PS_NUM_INVALID, |
| }; |
| |
| static inline uint16_t mod_sns_half() |
| { |
| return (RLC_MAX_SNS / 2) - 1; |
| } |
| |
| struct gprs_rlc_data_block_info { |
| unsigned int data_len; /* EGPRS: N2, GPRS: N2-2, N-2 */ |
| unsigned int bsn; |
| unsigned int ti; |
| unsigned int e; |
| unsigned int cv; /* FBI == 1 <=> CV == 0 */ |
| unsigned int pi; |
| unsigned int spb; |
| }; |
| |
| struct gprs_rlc_data_info { |
| GprsCodingScheme cs; |
| unsigned int r; |
| unsigned int si; |
| unsigned int tfi; |
| unsigned int cps; |
| unsigned int rsb; |
| unsigned int usf; |
| unsigned int es_p; |
| unsigned int rrbp; |
| unsigned int pr; |
| uint8_t num_data_blocks; /* this can actually be only 0, 1, 2: enforced in gprs_rlc_data_header_init() */ |
| unsigned int with_padding; |
| unsigned int data_offs_bits[2]; |
| struct gprs_rlc_data_block_info block_info[2]; |
| }; |
| |
| /* holds the current status of the block w.r.t UL/DL split blocks */ |
| union split_block_status { |
| egprs_rlc_ul_reseg_bsn_state block_status_ul; |
| egprs_rlc_dl_reseg_bsn_state block_status_dl; |
| }; |
| |
| struct gprs_rlc_data { |
| uint8_t *prepare(size_t block_data_length); |
| void put_data(const uint8_t *data, size_t len); |
| |
| /* block data including LI headers */ |
| uint8_t block[RLC_MAX_LEN]; |
| /* block data len including LI headers*/ |
| uint8_t len; |
| |
| struct gprs_rlc_data_block_info block_info; |
| /* |
| * cs_current_trans is variable to hold the cs_last value for |
| * current transmission. cs_current_trans is same as cs_last during |
| * transmission case. during retransmission cs_current_trans is |
| * fetched from egprs_mcs_retx_tbl table based on |
| * cs and demanded cs.reference is 44.060 Table |
| * 8.1.1.1 and Table 8.1.1.2 |
| * For UL. cs_last shall be used everywhere. |
| */ |
| GprsCodingScheme cs_current_trans; |
| GprsCodingScheme cs_last; |
| |
| /* |
| * The MCS of initial transmission of a BSN |
| * This variable is used for split block |
| * processing in DL |
| */ |
| GprsCodingScheme cs_init; |
| |
| /* puncturing scheme value to be used for next transmission*/ |
| enum egprs_puncturing_values next_ps; |
| |
| /* holds the status of the block w.r.t UL/DL split blocks*/ |
| union split_block_status spb_status; |
| }; |
| |
| void gprs_rlc_data_info_init_dl(struct gprs_rlc_data_info *rlc, |
| GprsCodingScheme cs, bool with_padding, const unsigned int spb); |
| void gprs_rlc_data_info_init_ul(struct gprs_rlc_data_info *rlc, |
| GprsCodingScheme cs, bool with_padding); |
| void gprs_rlc_data_block_info_init(struct gprs_rlc_data_block_info *rdbi, |
| GprsCodingScheme cs, bool with_padding, const unsigned int spb); |
| unsigned int gprs_rlc_mcs_cps(GprsCodingScheme cs, enum egprs_puncturing_values |
| punct, enum egprs_puncturing_values punct2, bool with_padding); |
| void gprs_rlc_mcs_cps_decode(unsigned int cps, GprsCodingScheme cs, |
| int *punct, int *punct2, int *with_padding); |
| enum egprs_puncturing_values gprs_get_punct_scheme(enum egprs_puncturing_values |
| punct, const GprsCodingScheme &cs, |
| const GprsCodingScheme &cs_current_trans, |
| const enum egprs_rlcmac_dl_spb spb); |
| void gprs_update_punct_scheme(enum egprs_puncturing_values *punct, |
| const GprsCodingScheme &cs); |
| /* |
| * I hold the currently transferred blocks and will provide |
| * the routines to manipulate these arrays. |
| */ |
| struct gprs_rlc { |
| void init(); |
| gprs_rlc_data *block(int bsn); |
| gprs_rlc_data m_blocks[RLC_MAX_SNS/2]; |
| }; |
| |
| /** |
| * TODO: for GPRS/EDGE maybe make sns a template parameter |
| * so we create specialized versions... |
| */ |
| struct gprs_rlc_v_b { |
| /* Check for an individual frame */ |
| bool is_unacked(int bsn) const; |
| bool is_nacked(int bsn) const; |
| bool is_acked(int bsn) const; |
| bool is_resend(int bsn) const; |
| bool is_invalid(int bsn) const; |
| gprs_rlc_dl_bsn_state get_state(int bsn) const; |
| |
| /* Mark a RLC frame for something */ |
| void mark_unacked(int bsn); |
| void mark_nacked(int bsn); |
| void mark_acked(int bsn); |
| void mark_resend(int bsn); |
| void mark_invalid(int bsn); |
| |
| void reset(); |
| |
| |
| private: |
| bool is_state(int bsn, const gprs_rlc_dl_bsn_state state) const; |
| void mark(int bsn, const gprs_rlc_dl_bsn_state state); |
| |
| gprs_rlc_dl_bsn_state m_v_b[RLC_MAX_SNS/2]; /* acknowledge state array */ |
| }; |
| |
| |
| /** |
| * TODO: The UL/DL code could/should share a base class. |
| */ |
| class gprs_rlc_window { |
| public: |
| gprs_rlc_window(); |
| |
| const uint16_t mod_sns() const; |
| const uint16_t mod_sns(uint16_t bsn) const; |
| const uint16_t sns() const; |
| const uint16_t ws() const; |
| |
| void set_sns(uint16_t sns); |
| void set_ws(uint16_t ws); |
| |
| protected: |
| uint16_t m_sns; |
| uint16_t m_ws; |
| }; |
| |
| struct gprs_rlc_dl_window: public gprs_rlc_window { |
| void reset(); |
| |
| bool window_stalled() const; |
| bool window_empty() const; |
| |
| void increment_send(); |
| void raise(int moves); |
| |
| const uint16_t v_s() const; |
| const uint16_t v_s_mod(int offset) const; |
| const uint16_t v_a() const; |
| const uint16_t distance() const; |
| |
| /* Methods to manage reception */ |
| int resend_needed() const; |
| int mark_for_resend(); |
| void update(BTS *bts, char *show_rbb, uint16_t ssn, |
| uint16_t *lost, uint16_t *received); |
| void update(BTS *bts, const struct bitvec *rbb, |
| uint16_t first_bsn, uint16_t *lost, |
| uint16_t *received); |
| int move_window(); |
| void show_state(char *show_rbb); |
| int count_unacked(); |
| |
| uint16_t m_v_s; /* send state */ |
| uint16_t m_v_a; /* ack state */ |
| |
| gprs_rlc_v_b m_v_b; |
| |
| gprs_rlc_dl_window(); |
| }; |
| |
| struct gprs_rlc_v_n { |
| void reset(); |
| |
| void mark_received(int bsn); |
| void mark_missing(int bsn); |
| |
| bool is_received(int bsn) const; |
| |
| gprs_rlc_ul_bsn_state state(int bsn) const; |
| private: |
| bool is_state(int bsn, const gprs_rlc_ul_bsn_state state) const; |
| void mark(int bsn, const gprs_rlc_ul_bsn_state state); |
| gprs_rlc_ul_bsn_state m_v_n[RLC_MAX_SNS/2]; /* receive state array */ |
| }; |
| |
| struct gprs_rlc_ul_window: public gprs_rlc_window { |
| const uint16_t v_r() const; |
| const uint16_t v_q() const; |
| |
| const void set_v_r(int); |
| const void set_v_q(int); |
| void reset_state(); |
| |
| const uint16_t ssn() const; |
| |
| bool is_in_window(uint16_t bsn) const; |
| bool is_received(uint16_t bsn) const; |
| |
| void update_rbb(char *rbb); |
| uint16_t update_egprs_rbb(uint8_t *rbb); |
| void raise_v_r_to(int moves); |
| void raise_v_r(const uint16_t bsn); |
| uint16_t raise_v_q(); |
| |
| void raise_v_q(int); |
| |
| void receive_bsn(const uint16_t bsn); |
| bool invalidate_bsn(const uint16_t bsn); |
| |
| uint16_t m_v_r; /* receive state */ |
| uint16_t m_v_q; /* receive window state */ |
| |
| gprs_rlc_v_n m_v_n; |
| |
| gprs_rlc_ul_window(); |
| }; |
| |
| extern "C" { |
| /* TS 04.60 10.2.2 */ |
| #if OSMO_IS_LITTLE_ENDIAN |
| struct rlc_ul_header { |
| uint8_t r:1, |
| si:1, |
| cv:4, |
| pt:2; |
| uint8_t ti:1, |
| tfi:5, |
| pi:1, |
| spare:1; |
| uint8_t e:1, |
| bsn:7; |
| } __attribute__ ((packed)); |
| |
| struct rlc_dl_header { |
| uint8_t usf:3, |
| s_p:1, |
| rrbp:2, |
| pt:2; |
| uint8_t fbi:1, |
| tfi:5, |
| pr:2; |
| uint8_t e:1, |
| bsn:7; |
| } __attribute__ ((packed)); |
| |
| struct rlc_li_field { |
| uint8_t e:1, |
| m:1, |
| li:6; |
| } __attribute__ ((packed)); |
| |
| struct rlc_li_field_egprs { |
| uint8_t e:1, |
| li:7; |
| } __attribute__ ((packed)); |
| #else |
| # error "Only little endian headers are supported yet. TODO: add missing structs" |
| #endif |
| } |
| |
| inline bool gprs_rlc_v_b::is_state(int bsn, const gprs_rlc_dl_bsn_state type) const |
| { |
| return m_v_b[bsn & mod_sns_half()] == type; |
| } |
| |
| inline void gprs_rlc_v_b::mark(int bsn, const gprs_rlc_dl_bsn_state type) |
| { |
| m_v_b[bsn & mod_sns_half()] = type; |
| } |
| |
| inline bool gprs_rlc_v_b::is_nacked(int bsn) const |
| { |
| return is_state(bsn, GPRS_RLC_DL_BSN_NACKED); |
| } |
| |
| inline bool gprs_rlc_v_b::is_acked(int bsn) const |
| { |
| return is_state(bsn, GPRS_RLC_DL_BSN_ACKED); |
| } |
| |
| inline bool gprs_rlc_v_b::is_unacked(int bsn) const |
| { |
| return is_state(bsn, GPRS_RLC_DL_BSN_UNACKED); |
| } |
| |
| inline bool gprs_rlc_v_b::is_resend(int bsn) const |
| { |
| return is_state(bsn, GPRS_RLC_DL_BSN_RESEND); |
| } |
| |
| inline bool gprs_rlc_v_b::is_invalid(int bsn) const |
| { |
| return is_state(bsn, GPRS_RLC_DL_BSN_INVALID); |
| } |
| |
| inline gprs_rlc_dl_bsn_state gprs_rlc_v_b::get_state(int bsn) const |
| { |
| return m_v_b[bsn & mod_sns_half()]; |
| } |
| |
| inline void gprs_rlc_v_b::mark_resend(int bsn) |
| { |
| return mark(bsn, GPRS_RLC_DL_BSN_RESEND); |
| } |
| |
| inline void gprs_rlc_v_b::mark_unacked(int bsn) |
| { |
| return mark(bsn, GPRS_RLC_DL_BSN_UNACKED); |
| } |
| |
| inline void gprs_rlc_v_b::mark_acked(int bsn) |
| { |
| return mark(bsn, GPRS_RLC_DL_BSN_ACKED); |
| } |
| |
| inline void gprs_rlc_v_b::mark_nacked(int bsn) |
| { |
| return mark(bsn, GPRS_RLC_DL_BSN_NACKED); |
| } |
| |
| inline void gprs_rlc_v_b::mark_invalid(int bsn) |
| { |
| return mark(bsn, GPRS_RLC_DL_BSN_INVALID); |
| } |
| |
| inline gprs_rlc_window::gprs_rlc_window() |
| : m_sns(RLC_GPRS_SNS) |
| , m_ws(RLC_GPRS_WS) |
| { |
| } |
| |
| inline const uint16_t gprs_rlc_window::sns() const |
| { |
| return m_sns; |
| } |
| |
| inline const uint16_t gprs_rlc_window::ws() const |
| { |
| return m_ws; |
| } |
| |
| inline const uint16_t gprs_rlc_window::mod_sns() const |
| { |
| return sns() - 1; |
| } |
| |
| inline const uint16_t gprs_rlc_window::mod_sns(uint16_t bsn) const |
| { |
| return bsn & mod_sns(); |
| } |
| |
| inline gprs_rlc_dl_window::gprs_rlc_dl_window() |
| : m_v_s(0) |
| , m_v_a(0) |
| { |
| reset(); |
| } |
| |
| inline const uint16_t gprs_rlc_dl_window::v_s() const |
| { |
| return m_v_s; |
| } |
| |
| inline const uint16_t gprs_rlc_dl_window::v_s_mod(int offset) const |
| { |
| return mod_sns(m_v_s + offset); |
| } |
| |
| inline const uint16_t gprs_rlc_dl_window::v_a() const |
| { |
| return m_v_a; |
| } |
| |
| inline bool gprs_rlc_dl_window::window_stalled() const |
| { |
| return (mod_sns(m_v_s - m_v_a)) == ws(); |
| } |
| |
| inline bool gprs_rlc_dl_window::window_empty() const |
| { |
| return m_v_s == m_v_a; |
| } |
| |
| inline void gprs_rlc_dl_window::increment_send() |
| { |
| m_v_s = (m_v_s + 1) & mod_sns(); |
| } |
| |
| inline void gprs_rlc_dl_window::raise(int moves) |
| { |
| m_v_a = (m_v_a + moves) & mod_sns(); |
| } |
| |
| inline const uint16_t gprs_rlc_dl_window::distance() const |
| { |
| return (m_v_s - m_v_a) & mod_sns(); |
| } |
| |
| inline gprs_rlc_ul_window::gprs_rlc_ul_window() |
| : m_v_r(0) |
| , m_v_q(0) |
| { |
| m_v_n.reset(); |
| } |
| |
| inline bool gprs_rlc_ul_window::is_in_window(uint16_t bsn) const |
| { |
| uint16_t offset_v_q; |
| |
| /* current block relative to lowest unreceived block */ |
| offset_v_q = (bsn - m_v_q) & mod_sns(); |
| /* If out of window (may happen if blocks below V(Q) are received |
| * again. */ |
| return offset_v_q < ws(); |
| } |
| |
| inline bool gprs_rlc_ul_window::is_received(uint16_t bsn) const |
| { |
| uint16_t offset_v_r; |
| |
| /* Offset to the end of the received window */ |
| offset_v_r = (m_v_r - 1 - bsn) & mod_sns(); |
| return is_in_window(bsn) && m_v_n.is_received(bsn) && offset_v_r < ws(); |
| } |
| |
| inline void gprs_rlc_ul_window::reset_state() |
| { |
| m_v_r = 0; |
| m_v_q = 0; |
| } |
| |
| inline const void gprs_rlc_ul_window::set_v_r(int v_r) |
| { |
| m_v_r = v_r; |
| } |
| |
| inline const void gprs_rlc_ul_window::set_v_q(int v_q) |
| { |
| m_v_q = v_q; |
| } |
| |
| inline const uint16_t gprs_rlc_ul_window::v_r() const |
| { |
| return m_v_r; |
| } |
| |
| inline const uint16_t gprs_rlc_ul_window::v_q() const |
| { |
| return m_v_q; |
| } |
| |
| inline const uint16_t gprs_rlc_ul_window::ssn() const |
| { |
| return m_v_r; |
| } |
| |
| inline void gprs_rlc_ul_window::raise_v_r_to(int moves) |
| { |
| m_v_r = mod_sns(m_v_r + moves); |
| } |
| |
| inline void gprs_rlc_ul_window::raise_v_q(int incr) |
| { |
| m_v_q = mod_sns(m_v_q + incr); |
| } |
| |
| inline void gprs_rlc_v_n::mark_received(int bsn) |
| { |
| return mark(bsn, GPRS_RLC_UL_BSN_RECEIVED); |
| } |
| |
| inline void gprs_rlc_v_n::mark_missing(int bsn) |
| { |
| return mark(bsn, GPRS_RLC_UL_BSN_MISSING); |
| } |
| |
| inline bool gprs_rlc_v_n::is_received(int bsn) const |
| { |
| return is_state(bsn, GPRS_RLC_UL_BSN_RECEIVED); |
| } |
| |
| inline bool gprs_rlc_v_n::is_state(int bsn, gprs_rlc_ul_bsn_state type) const |
| { |
| return m_v_n[bsn & mod_sns_half()] == type; |
| } |
| |
| inline void gprs_rlc_v_n::mark(int bsn, gprs_rlc_ul_bsn_state type) |
| { |
| m_v_n[bsn & mod_sns_half()] = type; |
| } |
| |
| inline gprs_rlc_ul_bsn_state gprs_rlc_v_n::state(int bsn) const |
| { |
| return m_v_n[bsn & mod_sns_half()]; |
| } |
| |
| inline void gprs_rlc::init() |
| { |
| memset(m_blocks, 0, sizeof(m_blocks)); |
| } |
| |
| inline gprs_rlc_data *gprs_rlc::block(int bsn) |
| { |
| return &m_blocks[bsn & mod_sns_half()]; |
| } |