mirror of https://gerrit.osmocom.org/libosmocore
208 lines
7.9 KiB
C
208 lines
7.9 KiB
C
/*! \file gsm/gprs_rlc.c
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* helper functions for (E)GPRS RLC according to 3GPP TS 44.060.
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*
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* (C) 2016 by Thomas Thou
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* (C) 2016-2017 by sysmocom - s.f.m.c. GmbH
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* (C) 2017 by Harald Welte <laforge@gnumonks.org>
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* All Rights Reserved.
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*
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* SPDX-License-Identifier: GPL-2.0+
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*/
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#include <errno.h>
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#include <string.h>
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#include <osmocom/core/utils.h>
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#include <osmocom/coding/gsm0503_coding.h>
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#include <osmocom/gsm/protocol/gsm_44_060.h>
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#define EGPRS_CPS_TYPE1_TBL_SZ 29
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#define EGPRS_CPS_TYPE2_TBL_SZ 8
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#define EGPRS_CPS_TYPE3_TBL_SZ 16
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/* 3GPP TS 44.060 10.4.8a.1.1 "Header type 1" */
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static const struct egprs_cps egprs_cps_table_type1[EGPRS_CPS_TYPE1_TBL_SZ] = {
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{ .bits = 0, .mcs = EGPRS_MCS9, .p = { EGPRS_CPS_P1, EGPRS_CPS_P1 } },
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{ .bits = 1, .mcs = EGPRS_MCS9, .p = { EGPRS_CPS_P1, EGPRS_CPS_P2 } },
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{ .bits = 2, .mcs = EGPRS_MCS9, .p = { EGPRS_CPS_P1, EGPRS_CPS_P3 } },
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{ .bits = 3, .mcs = EGPRS_NUM_MCS, .p = { EGPRS_CPS_NONE, EGPRS_CPS_NONE } }, /* reserved for future use */
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{ .bits = 4, .mcs = EGPRS_MCS9, .p = { EGPRS_CPS_P2, EGPRS_CPS_P1 } },
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{ .bits = 5, .mcs = EGPRS_MCS9, .p = { EGPRS_CPS_P2, EGPRS_CPS_P2 } },
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{ .bits = 6, .mcs = EGPRS_MCS9, .p = { EGPRS_CPS_P2, EGPRS_CPS_P3 } },
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{ .bits = 7, .mcs = EGPRS_NUM_MCS, .p = { EGPRS_CPS_NONE, EGPRS_CPS_NONE } }, /* reserved for future use */
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{ .bits = 8, .mcs = EGPRS_MCS9, .p = { EGPRS_CPS_P3, EGPRS_CPS_P1 } },
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{ .bits = 9, .mcs = EGPRS_MCS9, .p = { EGPRS_CPS_P3, EGPRS_CPS_P2 } },
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{ .bits = 10, .mcs = EGPRS_MCS9, .p = { EGPRS_CPS_P3, EGPRS_CPS_P3 } },
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{ .bits = 11, .mcs = EGPRS_MCS8, .p = { EGPRS_CPS_P1, EGPRS_CPS_P1 } },
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{ .bits = 12, .mcs = EGPRS_MCS8, .p = { EGPRS_CPS_P1, EGPRS_CPS_P2 } },
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{ .bits = 13, .mcs = EGPRS_MCS8, .p = { EGPRS_CPS_P1, EGPRS_CPS_P3 } },
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{ .bits = 14, .mcs = EGPRS_MCS8, .p = { EGPRS_CPS_P2, EGPRS_CPS_P1 } },
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{ .bits = 15, .mcs = EGPRS_MCS8, .p = { EGPRS_CPS_P2, EGPRS_CPS_P2 } },
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{ .bits = 16, .mcs = EGPRS_MCS8, .p = { EGPRS_CPS_P2, EGPRS_CPS_P3 } },
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{ .bits = 17, .mcs = EGPRS_MCS8, .p = { EGPRS_CPS_P3, EGPRS_CPS_P1 } },
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{ .bits = 18, .mcs = EGPRS_MCS8, .p = { EGPRS_CPS_P3, EGPRS_CPS_P2 } },
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{ .bits = 19, .mcs = EGPRS_MCS8, .p = { EGPRS_CPS_P3, EGPRS_CPS_P3 } },
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{ .bits = 20, .mcs = EGPRS_MCS7, .p = { EGPRS_CPS_P1, EGPRS_CPS_P1 } },
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{ .bits = 21, .mcs = EGPRS_MCS7, .p = { EGPRS_CPS_P1, EGPRS_CPS_P2 } },
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{ .bits = 22, .mcs = EGPRS_MCS7, .p = { EGPRS_CPS_P1, EGPRS_CPS_P3 } },
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{ .bits = 23, .mcs = EGPRS_MCS7, .p = { EGPRS_CPS_P2, EGPRS_CPS_P1 } },
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{ .bits = 24, .mcs = EGPRS_MCS7, .p = { EGPRS_CPS_P2, EGPRS_CPS_P2 } },
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{ .bits = 25, .mcs = EGPRS_MCS7, .p = { EGPRS_CPS_P2, EGPRS_CPS_P3 } },
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{ .bits = 26, .mcs = EGPRS_MCS7, .p = { EGPRS_CPS_P3, EGPRS_CPS_P1 } },
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{ .bits = 27, .mcs = EGPRS_MCS7, .p = { EGPRS_CPS_P3, EGPRS_CPS_P2 } },
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{ .bits = 28, .mcs = EGPRS_MCS7, .p = { EGPRS_CPS_P3, EGPRS_CPS_P3 } },
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};
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/*
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* 3GPP TS 44.060 10.4.8a.2.1
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* "Header type 2 in EGPRS TBF or uplink EGPRS2-A TBF"
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*/
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static const struct egprs_cps egprs_cps_table_type2[EGPRS_CPS_TYPE2_TBL_SZ] = {
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{ .bits = 0, .mcs = EGPRS_MCS6, .p = { EGPRS_CPS_P1, EGPRS_CPS_NONE } },
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{ .bits = 1, .mcs = EGPRS_MCS6, .p = { EGPRS_CPS_P2, EGPRS_CPS_NONE } },
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{ .bits = 2, .mcs = EGPRS_MCS6, .p = { EGPRS_CPS_P1, EGPRS_CPS_NONE } },
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{ .bits = 3, .mcs = EGPRS_MCS6, .p = { EGPRS_CPS_P2, EGPRS_CPS_NONE } },
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{ .bits = 4, .mcs = EGPRS_MCS5, .p = { EGPRS_CPS_P1, EGPRS_CPS_NONE } },
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{ .bits = 5, .mcs = EGPRS_MCS5, .p = { EGPRS_CPS_P2, EGPRS_CPS_NONE } },
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{ .bits = 6, .mcs = EGPRS_MCS6, .p = { EGPRS_CPS_P1, EGPRS_CPS_NONE } },
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{ .bits = 7, .mcs = EGPRS_MCS6, .p = { EGPRS_CPS_P2, EGPRS_CPS_NONE } },
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};
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/* 3GPP TS 44.060 10.4.8a.3 "Header type 3" */
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static const struct egprs_cps egprs_cps_table_type3[EGPRS_CPS_TYPE3_TBL_SZ] = {
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{ .bits = 0, .mcs = EGPRS_MCS4, .p = { EGPRS_CPS_P1, EGPRS_CPS_NONE } },
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{ .bits = 1, .mcs = EGPRS_MCS4, .p = { EGPRS_CPS_P2, EGPRS_CPS_NONE } },
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{ .bits = 2, .mcs = EGPRS_MCS4, .p = { EGPRS_CPS_P3, EGPRS_CPS_NONE } },
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{ .bits = 3, .mcs = EGPRS_MCS3, .p = { EGPRS_CPS_P1, EGPRS_CPS_NONE } },
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{ .bits = 4, .mcs = EGPRS_MCS3, .p = { EGPRS_CPS_P2, EGPRS_CPS_NONE } },
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{ .bits = 5, .mcs = EGPRS_MCS3, .p = { EGPRS_CPS_P3, EGPRS_CPS_NONE } },
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{ .bits = 6, .mcs = EGPRS_MCS3, .p = { EGPRS_CPS_P1, EGPRS_CPS_NONE } },
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{ .bits = 7, .mcs = EGPRS_MCS3, .p = { EGPRS_CPS_P2, EGPRS_CPS_NONE } },
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{ .bits = 8, .mcs = EGPRS_MCS3, .p = { EGPRS_CPS_P3, EGPRS_CPS_NONE } },
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{ .bits = 9, .mcs = EGPRS_MCS2, .p = { EGPRS_CPS_P1, EGPRS_CPS_NONE } },
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{ .bits = 10, .mcs = EGPRS_MCS2, .p = { EGPRS_CPS_P2, EGPRS_CPS_NONE } },
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{ .bits = 11, .mcs = EGPRS_MCS1, .p = { EGPRS_CPS_P1, EGPRS_CPS_NONE } },
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{ .bits = 12, .mcs = EGPRS_MCS1, .p = { EGPRS_CPS_P2, EGPRS_CPS_NONE } },
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{ .bits = 13, .mcs = EGPRS_MCS2, .p = { EGPRS_CPS_P1, EGPRS_CPS_NONE } },
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{ .bits = 14, .mcs = EGPRS_MCS2, .p = { EGPRS_CPS_P2, EGPRS_CPS_NONE } },
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{ .bits = 15, .mcs = EGPRS_MCS0, .p = { EGPRS_CPS_NONE, EGPRS_CPS_NONE } },
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};
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int egprs_get_cps(struct egprs_cps *cps, uint8_t type, uint8_t bits)
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{
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const struct egprs_cps *table_cps;
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switch (type) {
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case EGPRS_HDR_TYPE1:
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if (bits >= EGPRS_CPS_TYPE1_TBL_SZ)
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return -EINVAL;
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table_cps = &egprs_cps_table_type1[bits];
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break;
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case EGPRS_HDR_TYPE2:
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if (bits >= EGPRS_CPS_TYPE2_TBL_SZ)
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return -EINVAL;
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table_cps = &egprs_cps_table_type2[bits];
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break;
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case EGPRS_HDR_TYPE3:
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if (bits >= EGPRS_CPS_TYPE3_TBL_SZ)
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return -EINVAL;
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table_cps = &egprs_cps_table_type3[bits];
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break;
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default:
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return -EINVAL;
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}
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memcpy(cps, table_cps, sizeof *cps);
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return 0;
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}
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struct gprs_cs_desc {
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struct {
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uint8_t bytes;
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uint8_t bits;
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} uplink, downlink;
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};
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const struct gprs_cs_desc gprs_cs_desc[_NUM_OSMO_GPRS_CS] = {
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[OSMO_GPRS_CS1] = { {23, 0}, {23, 0} },
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[OSMO_GPRS_CS2] = { {33, 7}, {33, 7} },
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[OSMO_GPRS_CS3] = { {39, 3}, {39, 3} },
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[OSMO_GPRS_CS4] = { {53, 7}, {53, 7} },
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[OSMO_GPRS_MCS1] = { {26, 1}, {26, 1} },
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[OSMO_GPRS_MCS2] = { {32, 1}, {32, 1} },
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[OSMO_GPRS_MCS3] = { {41, 1}, {41, 1} },
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[OSMO_GPRS_MCS4] = { {48, 1}, {48, 1} },
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[OSMO_GPRS_MCS5] = { {60, 7}, {59, 6} },
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[OSMO_GPRS_MCS6] = { {78, 7}, {77, 6} },
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[OSMO_GPRS_MCS7] = { {118, 2}, {117, 4} },
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[OSMO_GPRS_MCS8] = { {142, 2}, {141, 4} },
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[OSMO_GPRS_MCS9] = { {154, 2}, {153, 4} },
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};
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/*! Return size of (E)GPRS uplink block for given coding scheme in bits */
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int osmo_gprs_ul_block_size_bits(enum osmo_gprs_cs cs)
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{
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if (cs >= ARRAY_SIZE(gprs_cs_desc))
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return -EINVAL;
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return gprs_cs_desc[cs].uplink.bytes * 8 + gprs_cs_desc[cs].uplink.bits;
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}
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/*! Return size of (E)GPRS downlink block for given coding scheme in bits */
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int osmo_gprs_dl_block_size_bits(enum osmo_gprs_cs cs)
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{
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if (cs >= ARRAY_SIZE(gprs_cs_desc))
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return -EINVAL;
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return gprs_cs_desc[cs].downlink.bytes * 8 + gprs_cs_desc[cs].downlink.bits;
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}
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/*! Return size of (E)GPRS uplink block for given coding scheme in bytes */
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int osmo_gprs_ul_block_size_bytes(enum osmo_gprs_cs cs)
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{
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int rc;
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if (cs >= ARRAY_SIZE(gprs_cs_desc))
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return -EINVAL;
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rc = gprs_cs_desc[cs].uplink.bytes;
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if (gprs_cs_desc[cs].uplink.bits)
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rc++;
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return rc;
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}
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/*! Return size of (E)GPRS downlink block for given coding scheme in bytes */
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int osmo_gprs_dl_block_size_bytes(enum osmo_gprs_cs cs)
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{
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int rc;
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if (cs >= ARRAY_SIZE(gprs_cs_desc))
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return -EINVAL;
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rc = gprs_cs_desc[cs].downlink.bytes;
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if (gprs_cs_desc[cs].downlink.bits)
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rc++;
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return rc;
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}
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/*! Return coding scheme for given (E)GPRS uplink block size */
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enum osmo_gprs_cs osmo_gprs_ul_cs_by_block_bytes(uint8_t block_size)
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{
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unsigned int i;
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for (i = 0; i < ARRAY_SIZE(gprs_cs_desc); i++) {
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if (block_size == osmo_gprs_ul_block_size_bytes(i))
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return i;
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}
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return OSMO_GPRS_CS_NONE;
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}
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/*! Return coding scheme for given (E)GPRS downlink block size */
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enum osmo_gprs_cs osmo_gprs_dl_cs_by_block_bytes(uint8_t block_size)
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{
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unsigned int i;
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for (i = 0; i < ARRAY_SIZE(gprs_cs_desc); i++) {
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if (block_size == osmo_gprs_dl_block_size_bytes(i))
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return i;
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}
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return OSMO_GPRS_CS_NONE;
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}
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