| /*! \file gsm/gprs_rlc.c |
| * helper functions for (E)GPRS RLC according to 3GPP TS 44.060. |
| * |
| * (C) 2016 by Thomas Thou |
| * (C) 2016-2017 by sysmocom - s.f.m.c. GmbH |
| * (C) 2017 by Harald Welte <laforge@gnumonks.org> |
| * All Rights Reserved. |
| * |
| * SPDX-License-Identifier: GPL-2.0+ |
| */ |
| |
| #include <errno.h> |
| #include <string.h> |
| |
| #include <osmocom/core/utils.h> |
| #include <osmocom/gprs/gprs_rlc.h> |
| #include <osmocom/coding/gsm0503_coding.h> |
| #include <osmocom/gprs/protocol/gsm_04_60.h> |
| |
| #define EGPRS_CPS_TYPE1_TBL_SZ 29 |
| #define EGPRS_CPS_TYPE2_TBL_SZ 8 |
| #define EGPRS_CPS_TYPE3_TBL_SZ 16 |
| |
| /* 3GPP TS 44.060 10.4.8a.1.1 "Header type 1" */ |
| static const struct egprs_cps egprs_cps_table_type1[EGPRS_CPS_TYPE1_TBL_SZ] = { |
| { .bits = 0, .mcs = EGPRS_MCS9, .p = { EGPRS_CPS_P1, EGPRS_CPS_P1 } }, |
| { .bits = 1, .mcs = EGPRS_MCS9, .p = { EGPRS_CPS_P1, EGPRS_CPS_P2 } }, |
| { .bits = 2, .mcs = EGPRS_MCS9, .p = { EGPRS_CPS_P1, EGPRS_CPS_P3 } }, |
| { .bits = 3, .mcs = EGPRS_NUM_MCS, .p = { EGPRS_CPS_NONE, EGPRS_CPS_NONE } }, /* reserved for future use */ |
| { .bits = 4, .mcs = EGPRS_MCS9, .p = { EGPRS_CPS_P2, EGPRS_CPS_P1 } }, |
| { .bits = 5, .mcs = EGPRS_MCS9, .p = { EGPRS_CPS_P2, EGPRS_CPS_P2 } }, |
| { .bits = 6, .mcs = EGPRS_MCS9, .p = { EGPRS_CPS_P2, EGPRS_CPS_P3 } }, |
| { .bits = 7, .mcs = EGPRS_NUM_MCS, .p = { EGPRS_CPS_NONE, EGPRS_CPS_NONE } }, /* reserved for future use */ |
| { .bits = 8, .mcs = EGPRS_MCS9, .p = { EGPRS_CPS_P3, EGPRS_CPS_P1 } }, |
| { .bits = 9, .mcs = EGPRS_MCS9, .p = { EGPRS_CPS_P3, EGPRS_CPS_P2 } }, |
| { .bits = 10, .mcs = EGPRS_MCS9, .p = { EGPRS_CPS_P3, EGPRS_CPS_P3 } }, |
| { .bits = 11, .mcs = EGPRS_MCS8, .p = { EGPRS_CPS_P1, EGPRS_CPS_P1 } }, |
| { .bits = 12, .mcs = EGPRS_MCS8, .p = { EGPRS_CPS_P1, EGPRS_CPS_P2 } }, |
| { .bits = 13, .mcs = EGPRS_MCS8, .p = { EGPRS_CPS_P1, EGPRS_CPS_P3 } }, |
| { .bits = 14, .mcs = EGPRS_MCS8, .p = { EGPRS_CPS_P2, EGPRS_CPS_P1 } }, |
| { .bits = 15, .mcs = EGPRS_MCS8, .p = { EGPRS_CPS_P2, EGPRS_CPS_P2 } }, |
| { .bits = 16, .mcs = EGPRS_MCS8, .p = { EGPRS_CPS_P2, EGPRS_CPS_P3 } }, |
| { .bits = 17, .mcs = EGPRS_MCS8, .p = { EGPRS_CPS_P3, EGPRS_CPS_P1 } }, |
| { .bits = 18, .mcs = EGPRS_MCS8, .p = { EGPRS_CPS_P3, EGPRS_CPS_P2 } }, |
| { .bits = 19, .mcs = EGPRS_MCS8, .p = { EGPRS_CPS_P3, EGPRS_CPS_P3 } }, |
| { .bits = 20, .mcs = EGPRS_MCS7, .p = { EGPRS_CPS_P1, EGPRS_CPS_P1 } }, |
| { .bits = 21, .mcs = EGPRS_MCS7, .p = { EGPRS_CPS_P1, EGPRS_CPS_P2 } }, |
| { .bits = 22, .mcs = EGPRS_MCS7, .p = { EGPRS_CPS_P1, EGPRS_CPS_P3 } }, |
| { .bits = 23, .mcs = EGPRS_MCS7, .p = { EGPRS_CPS_P2, EGPRS_CPS_P1 } }, |
| { .bits = 24, .mcs = EGPRS_MCS7, .p = { EGPRS_CPS_P2, EGPRS_CPS_P2 } }, |
| { .bits = 25, .mcs = EGPRS_MCS7, .p = { EGPRS_CPS_P2, EGPRS_CPS_P3 } }, |
| { .bits = 26, .mcs = EGPRS_MCS7, .p = { EGPRS_CPS_P3, EGPRS_CPS_P1 } }, |
| { .bits = 27, .mcs = EGPRS_MCS7, .p = { EGPRS_CPS_P3, EGPRS_CPS_P2 } }, |
| { .bits = 28, .mcs = EGPRS_MCS7, .p = { EGPRS_CPS_P3, EGPRS_CPS_P3 } }, |
| }; |
| |
| /* |
| * 3GPP TS 44.060 10.4.8a.2.1 |
| * "Header type 2 in EGPRS TBF or uplink EGPRS2-A TBF" |
| */ |
| static const struct egprs_cps egprs_cps_table_type2[EGPRS_CPS_TYPE2_TBL_SZ] = { |
| { .bits = 0, .mcs = EGPRS_MCS6, .p = { EGPRS_CPS_P1, EGPRS_CPS_NONE } }, |
| { .bits = 1, .mcs = EGPRS_MCS6, .p = { EGPRS_CPS_P2, EGPRS_CPS_NONE } }, |
| { .bits = 2, .mcs = EGPRS_MCS6, .p = { EGPRS_CPS_P1, EGPRS_CPS_NONE } }, |
| { .bits = 3, .mcs = EGPRS_MCS6, .p = { EGPRS_CPS_P2, EGPRS_CPS_NONE } }, |
| { .bits = 4, .mcs = EGPRS_MCS5, .p = { EGPRS_CPS_P1, EGPRS_CPS_NONE } }, |
| { .bits = 5, .mcs = EGPRS_MCS5, .p = { EGPRS_CPS_P2, EGPRS_CPS_NONE } }, |
| { .bits = 6, .mcs = EGPRS_MCS6, .p = { EGPRS_CPS_P1, EGPRS_CPS_NONE } }, |
| { .bits = 7, .mcs = EGPRS_MCS6, .p = { EGPRS_CPS_P2, EGPRS_CPS_NONE } }, |
| }; |
| |
| /* 3GPP TS 44.060 10.4.8a.3 "Header type 3" */ |
| static const struct egprs_cps egprs_cps_table_type3[EGPRS_CPS_TYPE3_TBL_SZ] = { |
| { .bits = 0, .mcs = EGPRS_MCS4, .p = { EGPRS_CPS_P1, EGPRS_CPS_NONE } }, |
| { .bits = 1, .mcs = EGPRS_MCS4, .p = { EGPRS_CPS_P2, EGPRS_CPS_NONE } }, |
| { .bits = 2, .mcs = EGPRS_MCS4, .p = { EGPRS_CPS_P3, EGPRS_CPS_NONE } }, |
| { .bits = 3, .mcs = EGPRS_MCS3, .p = { EGPRS_CPS_P1, EGPRS_CPS_NONE } }, |
| { .bits = 4, .mcs = EGPRS_MCS3, .p = { EGPRS_CPS_P2, EGPRS_CPS_NONE } }, |
| { .bits = 5, .mcs = EGPRS_MCS3, .p = { EGPRS_CPS_P3, EGPRS_CPS_NONE } }, |
| { .bits = 6, .mcs = EGPRS_MCS3, .p = { EGPRS_CPS_P1, EGPRS_CPS_NONE } }, |
| { .bits = 7, .mcs = EGPRS_MCS3, .p = { EGPRS_CPS_P2, EGPRS_CPS_NONE } }, |
| { .bits = 8, .mcs = EGPRS_MCS3, .p = { EGPRS_CPS_P3, EGPRS_CPS_NONE } }, |
| { .bits = 9, .mcs = EGPRS_MCS2, .p = { EGPRS_CPS_P1, EGPRS_CPS_NONE } }, |
| { .bits = 10, .mcs = EGPRS_MCS2, .p = { EGPRS_CPS_P2, EGPRS_CPS_NONE } }, |
| { .bits = 11, .mcs = EGPRS_MCS1, .p = { EGPRS_CPS_P1, EGPRS_CPS_NONE } }, |
| { .bits = 12, .mcs = EGPRS_MCS1, .p = { EGPRS_CPS_P2, EGPRS_CPS_NONE } }, |
| { .bits = 13, .mcs = EGPRS_MCS2, .p = { EGPRS_CPS_P1, EGPRS_CPS_NONE } }, |
| { .bits = 14, .mcs = EGPRS_MCS2, .p = { EGPRS_CPS_P2, EGPRS_CPS_NONE } }, |
| { .bits = 15, .mcs = EGPRS_MCS0, .p = { EGPRS_CPS_NONE, EGPRS_CPS_NONE } }, |
| }; |
| |
| int egprs_get_cps(struct egprs_cps *cps, uint8_t type, uint8_t bits) |
| { |
| const struct egprs_cps *table_cps; |
| |
| switch (type) { |
| case EGPRS_HDR_TYPE1: |
| if (bits >= EGPRS_CPS_TYPE1_TBL_SZ) |
| return -EINVAL; |
| table_cps = &egprs_cps_table_type1[bits]; |
| break; |
| case EGPRS_HDR_TYPE2: |
| if (bits >= EGPRS_CPS_TYPE2_TBL_SZ) |
| return -EINVAL; |
| table_cps = &egprs_cps_table_type2[bits]; |
| break; |
| case EGPRS_HDR_TYPE3: |
| if (bits >= EGPRS_CPS_TYPE3_TBL_SZ) |
| return -EINVAL; |
| table_cps = &egprs_cps_table_type3[bits]; |
| break; |
| default: |
| return -EINVAL; |
| } |
| |
| memcpy(cps, table_cps, sizeof *cps); |
| |
| return 0; |
| } |
| |
| struct gprs_cs_desc { |
| struct { |
| uint8_t bytes; |
| uint8_t bits; |
| } uplink, downlink; |
| }; |
| |
| const struct gprs_cs_desc gprs_cs_desc[_NUM_OSMO_GPRS_CS] = { |
| [OSMO_GPRS_CS1] = { {23, 0}, {23, 0} }, |
| [OSMO_GPRS_CS2] = { {33, 7}, {33, 7} }, |
| [OSMO_GPRS_CS3] = { {39, 3}, {39, 3} }, |
| [OSMO_GPRS_CS4] = { {53, 7}, {53, 7} }, |
| |
| [OSMO_GPRS_MCS1] = { {26, 1}, {26, 1} }, |
| [OSMO_GPRS_MCS2] = { {32, 1}, {32, 1} }, |
| [OSMO_GPRS_MCS3] = { {41, 1}, {41, 1} }, |
| [OSMO_GPRS_MCS4] = { {48, 1}, {48, 1} }, |
| |
| [OSMO_GPRS_MCS5] = { {60, 7}, {59, 6} }, |
| [OSMO_GPRS_MCS6] = { {78, 7}, {77, 6} }, |
| [OSMO_GPRS_MCS7] = { {118, 2}, {117, 4} }, |
| [OSMO_GPRS_MCS8] = { {142, 2}, {141, 4} }, |
| [OSMO_GPRS_MCS9] = { {154, 2}, {153, 4} }, |
| }; |
| |
| /*! Return size of (E)GPRS uplink block for given coding scheme in bits */ |
| int osmo_gprs_ul_block_size_bits(enum osmo_gprs_cs cs) |
| { |
| if (cs >= ARRAY_SIZE(gprs_cs_desc)) |
| return -EINVAL; |
| return gprs_cs_desc[cs].uplink.bytes * 8 + gprs_cs_desc[cs].uplink.bits; |
| } |
| |
| /*! Return size of (E)GPRS downlink block for given coding scheme in bits */ |
| int osmo_gprs_dl_block_size_bits(enum osmo_gprs_cs cs) |
| { |
| if (cs >= ARRAY_SIZE(gprs_cs_desc)) |
| return -EINVAL; |
| return gprs_cs_desc[cs].downlink.bytes * 8 + gprs_cs_desc[cs].downlink.bits; |
| } |
| |
| /*! Return size of (E)GPRS uplink block for given coding scheme in bytes */ |
| int osmo_gprs_ul_block_size_bytes(enum osmo_gprs_cs cs) |
| { |
| int rc; |
| if (cs >= ARRAY_SIZE(gprs_cs_desc)) |
| return -EINVAL; |
| rc = gprs_cs_desc[cs].uplink.bytes; |
| if (gprs_cs_desc[cs].uplink.bits) |
| rc++; |
| return rc; |
| } |
| |
| /*! Return size of (E)GPRS downlink block for given coding scheme in bytes */ |
| int osmo_gprs_dl_block_size_bytes(enum osmo_gprs_cs cs) |
| { |
| int rc; |
| if (cs >= ARRAY_SIZE(gprs_cs_desc)) |
| return -EINVAL; |
| rc = gprs_cs_desc[cs].downlink.bytes; |
| if (gprs_cs_desc[cs].downlink.bits) |
| rc++; |
| return rc; |
| } |
| |
| /*! Return coding scheme for given (E)GPRS uplink block size */ |
| enum osmo_gprs_cs osmo_gprs_ul_cs_by_block_bytes(uint8_t block_size) |
| { |
| unsigned int i; |
| |
| for (i = 0; i < ARRAY_SIZE(gprs_cs_desc); i++) { |
| if (block_size == osmo_gprs_ul_block_size_bytes(i)) |
| return i; |
| } |
| return OSMO_GPRS_CS_NONE; |
| } |
| |
| /*! Return coding scheme for given (E)GPRS downlink block size */ |
| enum osmo_gprs_cs osmo_gprs_dl_cs_by_block_bytes(uint8_t block_size) |
| { |
| unsigned int i; |
| |
| for (i = 0; i < ARRAY_SIZE(gprs_cs_desc); i++) { |
| if (block_size == osmo_gprs_dl_block_size_bytes(i)) |
| return i; |
| } |
| return OSMO_GPRS_CS_NONE; |
| } |