Neels Hofmeyr | 17518fe | 2017-06-20 04:35:06 +0200 | [diff] [blame] | 1 | /*! \file gsm/gprs_rlc.c |
| 2 | * helper functions for (E)GPRS RLC according to 3GPP TS 44.060. |
Harald Welte | e08da97 | 2017-11-13 01:00:26 +0900 | [diff] [blame] | 3 | * |
| 4 | * (C) 2016 by Thomas Thou |
| 5 | * (C) 2016-2017 by sysmocom - s.f.m.c. GmbH |
| 6 | * (C) 2017 by Harald Welte <laforge@gnumonks.org> |
| 7 | * All Rights Reserved. |
| 8 | * |
| 9 | * SPDX-License-Identifier: GPL-2.0+ |
Neels Hofmeyr | 17518fe | 2017-06-20 04:35:06 +0200 | [diff] [blame] | 10 | */ |
| 11 | |
Tom Tsou | 9a5bbf3 | 2016-07-14 15:13:45 -0700 | [diff] [blame] | 12 | #include <errno.h> |
| 13 | #include <string.h> |
| 14 | |
Harald Welte | 35b2632 | 2017-07-31 19:36:52 +0200 | [diff] [blame] | 15 | #include <osmocom/core/utils.h> |
Tom Tsou | 9a5bbf3 | 2016-07-14 15:13:45 -0700 | [diff] [blame] | 16 | #include <osmocom/gprs/gprs_rlc.h> |
Max | c8cf820 | 2017-05-22 16:07:04 +0200 | [diff] [blame] | 17 | #include <osmocom/coding/gsm0503_coding.h> |
Tom Tsou | 9a5bbf3 | 2016-07-14 15:13:45 -0700 | [diff] [blame] | 18 | #include <osmocom/gprs/protocol/gsm_04_60.h> |
| 19 | |
| 20 | #define EGPRS_CPS_TYPE1_TBL_SZ 29 |
| 21 | #define EGPRS_CPS_TYPE2_TBL_SZ 8 |
| 22 | #define EGPRS_CPS_TYPE3_TBL_SZ 16 |
| 23 | |
| 24 | /* 3GPP TS 44.060 10.4.8a.1.1 "Header type 1" */ |
| 25 | static const struct egprs_cps egprs_cps_table_type1[EGPRS_CPS_TYPE1_TBL_SZ] = { |
Max | c8cf820 | 2017-05-22 16:07:04 +0200 | [diff] [blame] | 26 | { .bits = 0, .mcs = EGPRS_MCS9, .p = { EGPRS_CPS_P1, EGPRS_CPS_P1 } }, |
| 27 | { .bits = 1, .mcs = EGPRS_MCS9, .p = { EGPRS_CPS_P1, EGPRS_CPS_P2 } }, |
| 28 | { .bits = 2, .mcs = EGPRS_MCS9, .p = { EGPRS_CPS_P1, EGPRS_CPS_P3 } }, |
| 29 | { .bits = 3, .mcs = EGPRS_NUM_MCS, .p = { EGPRS_CPS_NONE, EGPRS_CPS_NONE } }, /* reserved for future use */ |
| 30 | { .bits = 4, .mcs = EGPRS_MCS9, .p = { EGPRS_CPS_P2, EGPRS_CPS_P1 } }, |
| 31 | { .bits = 5, .mcs = EGPRS_MCS9, .p = { EGPRS_CPS_P2, EGPRS_CPS_P2 } }, |
| 32 | { .bits = 6, .mcs = EGPRS_MCS9, .p = { EGPRS_CPS_P2, EGPRS_CPS_P3 } }, |
| 33 | { .bits = 7, .mcs = EGPRS_NUM_MCS, .p = { EGPRS_CPS_NONE, EGPRS_CPS_NONE } }, /* reserved for future use */ |
| 34 | { .bits = 8, .mcs = EGPRS_MCS9, .p = { EGPRS_CPS_P3, EGPRS_CPS_P1 } }, |
| 35 | { .bits = 9, .mcs = EGPRS_MCS9, .p = { EGPRS_CPS_P3, EGPRS_CPS_P2 } }, |
| 36 | { .bits = 10, .mcs = EGPRS_MCS9, .p = { EGPRS_CPS_P3, EGPRS_CPS_P3 } }, |
| 37 | { .bits = 11, .mcs = EGPRS_MCS8, .p = { EGPRS_CPS_P1, EGPRS_CPS_P1 } }, |
| 38 | { .bits = 12, .mcs = EGPRS_MCS8, .p = { EGPRS_CPS_P1, EGPRS_CPS_P2 } }, |
| 39 | { .bits = 13, .mcs = EGPRS_MCS8, .p = { EGPRS_CPS_P1, EGPRS_CPS_P3 } }, |
| 40 | { .bits = 14, .mcs = EGPRS_MCS8, .p = { EGPRS_CPS_P2, EGPRS_CPS_P1 } }, |
| 41 | { .bits = 15, .mcs = EGPRS_MCS8, .p = { EGPRS_CPS_P2, EGPRS_CPS_P2 } }, |
| 42 | { .bits = 16, .mcs = EGPRS_MCS8, .p = { EGPRS_CPS_P2, EGPRS_CPS_P3 } }, |
| 43 | { .bits = 17, .mcs = EGPRS_MCS8, .p = { EGPRS_CPS_P3, EGPRS_CPS_P1 } }, |
| 44 | { .bits = 18, .mcs = EGPRS_MCS8, .p = { EGPRS_CPS_P3, EGPRS_CPS_P2 } }, |
| 45 | { .bits = 19, .mcs = EGPRS_MCS8, .p = { EGPRS_CPS_P3, EGPRS_CPS_P3 } }, |
| 46 | { .bits = 20, .mcs = EGPRS_MCS7, .p = { EGPRS_CPS_P1, EGPRS_CPS_P1 } }, |
| 47 | { .bits = 21, .mcs = EGPRS_MCS7, .p = { EGPRS_CPS_P1, EGPRS_CPS_P2 } }, |
| 48 | { .bits = 22, .mcs = EGPRS_MCS7, .p = { EGPRS_CPS_P1, EGPRS_CPS_P3 } }, |
| 49 | { .bits = 23, .mcs = EGPRS_MCS7, .p = { EGPRS_CPS_P2, EGPRS_CPS_P1 } }, |
| 50 | { .bits = 24, .mcs = EGPRS_MCS7, .p = { EGPRS_CPS_P2, EGPRS_CPS_P2 } }, |
| 51 | { .bits = 25, .mcs = EGPRS_MCS7, .p = { EGPRS_CPS_P2, EGPRS_CPS_P3 } }, |
| 52 | { .bits = 26, .mcs = EGPRS_MCS7, .p = { EGPRS_CPS_P3, EGPRS_CPS_P1 } }, |
| 53 | { .bits = 27, .mcs = EGPRS_MCS7, .p = { EGPRS_CPS_P3, EGPRS_CPS_P2 } }, |
| 54 | { .bits = 28, .mcs = EGPRS_MCS7, .p = { EGPRS_CPS_P3, EGPRS_CPS_P3 } }, |
Tom Tsou | 9a5bbf3 | 2016-07-14 15:13:45 -0700 | [diff] [blame] | 55 | }; |
| 56 | |
| 57 | /* |
| 58 | * 3GPP TS 44.060 10.4.8a.2.1 |
| 59 | * "Header type 2 in EGPRS TBF or uplink EGPRS2-A TBF" |
| 60 | */ |
| 61 | static const struct egprs_cps egprs_cps_table_type2[EGPRS_CPS_TYPE2_TBL_SZ] = { |
Max | c8cf820 | 2017-05-22 16:07:04 +0200 | [diff] [blame] | 62 | { .bits = 0, .mcs = EGPRS_MCS6, .p = { EGPRS_CPS_P1, EGPRS_CPS_NONE } }, |
| 63 | { .bits = 1, .mcs = EGPRS_MCS6, .p = { EGPRS_CPS_P2, EGPRS_CPS_NONE } }, |
| 64 | { .bits = 2, .mcs = EGPRS_MCS6, .p = { EGPRS_CPS_P1, EGPRS_CPS_NONE } }, |
| 65 | { .bits = 3, .mcs = EGPRS_MCS6, .p = { EGPRS_CPS_P2, EGPRS_CPS_NONE } }, |
| 66 | { .bits = 4, .mcs = EGPRS_MCS5, .p = { EGPRS_CPS_P1, EGPRS_CPS_NONE } }, |
| 67 | { .bits = 5, .mcs = EGPRS_MCS5, .p = { EGPRS_CPS_P2, EGPRS_CPS_NONE } }, |
| 68 | { .bits = 6, .mcs = EGPRS_MCS6, .p = { EGPRS_CPS_P1, EGPRS_CPS_NONE } }, |
| 69 | { .bits = 7, .mcs = EGPRS_MCS6, .p = { EGPRS_CPS_P2, EGPRS_CPS_NONE } }, |
Tom Tsou | 9a5bbf3 | 2016-07-14 15:13:45 -0700 | [diff] [blame] | 70 | }; |
| 71 | |
| 72 | /* 3GPP TS 44.060 10.4.8a.3 "Header type 3" */ |
| 73 | static const struct egprs_cps egprs_cps_table_type3[EGPRS_CPS_TYPE3_TBL_SZ] = { |
Max | c8cf820 | 2017-05-22 16:07:04 +0200 | [diff] [blame] | 74 | { .bits = 0, .mcs = EGPRS_MCS4, .p = { EGPRS_CPS_P1, EGPRS_CPS_NONE } }, |
| 75 | { .bits = 1, .mcs = EGPRS_MCS4, .p = { EGPRS_CPS_P2, EGPRS_CPS_NONE } }, |
| 76 | { .bits = 2, .mcs = EGPRS_MCS4, .p = { EGPRS_CPS_P3, EGPRS_CPS_NONE } }, |
| 77 | { .bits = 3, .mcs = EGPRS_MCS3, .p = { EGPRS_CPS_P1, EGPRS_CPS_NONE } }, |
| 78 | { .bits = 4, .mcs = EGPRS_MCS3, .p = { EGPRS_CPS_P2, EGPRS_CPS_NONE } }, |
| 79 | { .bits = 5, .mcs = EGPRS_MCS3, .p = { EGPRS_CPS_P3, EGPRS_CPS_NONE } }, |
| 80 | { .bits = 6, .mcs = EGPRS_MCS3, .p = { EGPRS_CPS_P1, EGPRS_CPS_NONE } }, |
| 81 | { .bits = 7, .mcs = EGPRS_MCS3, .p = { EGPRS_CPS_P2, EGPRS_CPS_NONE } }, |
| 82 | { .bits = 8, .mcs = EGPRS_MCS3, .p = { EGPRS_CPS_P3, EGPRS_CPS_NONE } }, |
| 83 | { .bits = 9, .mcs = EGPRS_MCS2, .p = { EGPRS_CPS_P1, EGPRS_CPS_NONE } }, |
| 84 | { .bits = 10, .mcs = EGPRS_MCS2, .p = { EGPRS_CPS_P2, EGPRS_CPS_NONE } }, |
| 85 | { .bits = 11, .mcs = EGPRS_MCS1, .p = { EGPRS_CPS_P1, EGPRS_CPS_NONE } }, |
| 86 | { .bits = 12, .mcs = EGPRS_MCS1, .p = { EGPRS_CPS_P2, EGPRS_CPS_NONE } }, |
| 87 | { .bits = 13, .mcs = EGPRS_MCS2, .p = { EGPRS_CPS_P1, EGPRS_CPS_NONE } }, |
| 88 | { .bits = 14, .mcs = EGPRS_MCS2, .p = { EGPRS_CPS_P2, EGPRS_CPS_NONE } }, |
| 89 | { .bits = 15, .mcs = EGPRS_MCS0, .p = { EGPRS_CPS_NONE, EGPRS_CPS_NONE } }, |
Tom Tsou | 9a5bbf3 | 2016-07-14 15:13:45 -0700 | [diff] [blame] | 90 | }; |
| 91 | |
| 92 | int egprs_get_cps(struct egprs_cps *cps, uint8_t type, uint8_t bits) |
| 93 | { |
| 94 | const struct egprs_cps *table_cps; |
| 95 | |
| 96 | switch (type) { |
| 97 | case EGPRS_HDR_TYPE1: |
| 98 | if (bits >= EGPRS_CPS_TYPE1_TBL_SZ) |
| 99 | return -EINVAL; |
| 100 | table_cps = &egprs_cps_table_type1[bits]; |
| 101 | break; |
| 102 | case EGPRS_HDR_TYPE2: |
| 103 | if (bits >= EGPRS_CPS_TYPE2_TBL_SZ) |
| 104 | return -EINVAL; |
| 105 | table_cps = &egprs_cps_table_type2[bits]; |
| 106 | break; |
| 107 | case EGPRS_HDR_TYPE3: |
| 108 | if (bits >= EGPRS_CPS_TYPE3_TBL_SZ) |
| 109 | return -EINVAL; |
| 110 | table_cps = &egprs_cps_table_type3[bits]; |
| 111 | break; |
| 112 | default: |
| 113 | return -EINVAL; |
| 114 | } |
| 115 | |
| 116 | memcpy(cps, table_cps, sizeof *cps); |
| 117 | |
| 118 | return 0; |
| 119 | } |
Harald Welte | 35b2632 | 2017-07-31 19:36:52 +0200 | [diff] [blame] | 120 | |
| 121 | struct gprs_cs_desc { |
| 122 | struct { |
| 123 | uint8_t bytes; |
| 124 | uint8_t bits; |
| 125 | } uplink, downlink; |
| 126 | }; |
| 127 | |
| 128 | const struct gprs_cs_desc gprs_cs_desc[_NUM_OSMO_GPRS_CS] = { |
| 129 | [OSMO_GPRS_CS1] = { {23, 0}, {23, 0} }, |
| 130 | [OSMO_GPRS_CS2] = { {33, 7}, {33, 7} }, |
| 131 | [OSMO_GPRS_CS3] = { {39, 3}, {39, 3} }, |
| 132 | [OSMO_GPRS_CS4] = { {53, 7}, {53, 7} }, |
| 133 | |
| 134 | [OSMO_GPRS_MCS1] = { {26, 1}, {26, 1} }, |
| 135 | [OSMO_GPRS_MCS2] = { {32, 1}, {32, 1} }, |
| 136 | [OSMO_GPRS_MCS3] = { {41, 1}, {41, 1} }, |
| 137 | [OSMO_GPRS_MCS4] = { {48, 1}, {48, 1} }, |
| 138 | |
| 139 | [OSMO_GPRS_MCS5] = { {60, 7}, {59, 6} }, |
| 140 | [OSMO_GPRS_MCS6] = { {78, 7}, {77, 6} }, |
| 141 | [OSMO_GPRS_MCS7] = { {118, 2}, {117, 4} }, |
| 142 | [OSMO_GPRS_MCS8] = { {142, 2}, {141, 4} }, |
| 143 | [OSMO_GPRS_MCS9] = { {154, 2}, {153, 4} }, |
| 144 | }; |
| 145 | |
| 146 | /*! Return size of (E)GPRS uplink block for given coding scheme in bits */ |
| 147 | int osmo_gprs_ul_block_size_bits(enum osmo_gprs_cs cs) |
| 148 | { |
| 149 | if (cs >= ARRAY_SIZE(gprs_cs_desc)) |
| 150 | return -EINVAL; |
| 151 | return gprs_cs_desc[cs].uplink.bytes * 8 + gprs_cs_desc[cs].uplink.bits; |
| 152 | } |
| 153 | |
| 154 | /*! Return size of (E)GPRS downlink block for given coding scheme in bits */ |
| 155 | int osmo_gprs_dl_block_size_bits(enum osmo_gprs_cs cs) |
| 156 | { |
| 157 | if (cs >= ARRAY_SIZE(gprs_cs_desc)) |
| 158 | return -EINVAL; |
| 159 | return gprs_cs_desc[cs].downlink.bytes * 8 + gprs_cs_desc[cs].downlink.bits; |
| 160 | } |
| 161 | |
| 162 | /*! Return size of (E)GPRS uplink block for given coding scheme in bytes */ |
| 163 | int osmo_gprs_ul_block_size_bytes(enum osmo_gprs_cs cs) |
| 164 | { |
| 165 | int rc; |
| 166 | if (cs >= ARRAY_SIZE(gprs_cs_desc)) |
| 167 | return -EINVAL; |
| 168 | rc = gprs_cs_desc[cs].uplink.bytes; |
| 169 | if (gprs_cs_desc[cs].uplink.bits) |
| 170 | rc++; |
| 171 | return rc; |
| 172 | } |
| 173 | |
| 174 | /*! Return size of (E)GPRS downlink block for given coding scheme in bytes */ |
| 175 | int osmo_gprs_dl_block_size_bytes(enum osmo_gprs_cs cs) |
| 176 | { |
| 177 | int rc; |
| 178 | if (cs >= ARRAY_SIZE(gprs_cs_desc)) |
| 179 | return -EINVAL; |
| 180 | rc = gprs_cs_desc[cs].downlink.bytes; |
| 181 | if (gprs_cs_desc[cs].downlink.bits) |
| 182 | rc++; |
| 183 | return rc; |
| 184 | } |
| 185 | |
| 186 | /*! Return coding scheme for given (E)GPRS uplink block size */ |
| 187 | enum osmo_gprs_cs osmo_gprs_ul_cs_by_block_bytes(uint8_t block_size) |
| 188 | { |
| 189 | unsigned int i; |
| 190 | |
| 191 | for (i = 0; i < ARRAY_SIZE(gprs_cs_desc); i++) { |
| 192 | if (block_size == osmo_gprs_ul_block_size_bytes(i)) |
| 193 | return i; |
| 194 | } |
| 195 | return OSMO_GPRS_CS_NONE; |
| 196 | } |
| 197 | |
| 198 | /*! Return coding scheme for given (E)GPRS downlink block size */ |
| 199 | enum osmo_gprs_cs osmo_gprs_dl_cs_by_block_bytes(uint8_t block_size) |
| 200 | { |
| 201 | unsigned int i; |
| 202 | |
| 203 | for (i = 0; i < ARRAY_SIZE(gprs_cs_desc); i++) { |
| 204 | if (block_size == osmo_gprs_dl_block_size_bytes(i)) |
| 205 | return i; |
| 206 | } |
| 207 | return OSMO_GPRS_CS_NONE; |
| 208 | } |