Pau Espin Pedrol | 49a2f40 | 2021-07-27 17:33:07 +0200 | [diff] [blame] | 1 | /* tbf_dl_ass_fsm.c |
| 2 | * |
| 3 | * Copyright (C) 2021 by sysmocom - s.f.m.c. GmbH <info@sysmocom.de> |
| 4 | * Author: Pau Espin Pedrol <pespin@sysmocom.de> |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU General Public License |
| 8 | * as published by the Free Software Foundation; either version 2 |
| 9 | * of the License, or (at your option) any later version. |
| 10 | * |
| 11 | * This program is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | * GNU General Public License for more details. |
Pau Espin Pedrol | 49a2f40 | 2021-07-27 17:33:07 +0200 | [diff] [blame] | 15 | */ |
| 16 | |
| 17 | #include <unistd.h> |
| 18 | |
| 19 | #include <talloc.h> |
| 20 | |
| 21 | #include <osmocom/core/bitvec.h> |
| 22 | |
| 23 | #include <tbf_dl_ass_fsm.h> |
| 24 | #include <gprs_rlcmac.h> |
| 25 | #include <gprs_debug.h> |
| 26 | #include <gprs_ms.h> |
| 27 | #include <encoding.h> |
| 28 | #include <bts.h> |
| 29 | #include <tbf.h> |
Pau Espin Pedrol | a161bf4 | 2021-07-30 13:42:06 +0200 | [diff] [blame] | 30 | #include <tbf_dl.h> |
Pau Espin Pedrol | 49a2f40 | 2021-07-27 17:33:07 +0200 | [diff] [blame] | 31 | |
| 32 | #define X(s) (1 << (s)) |
| 33 | |
Pau Espin Pedrol | 76ef666 | 2023-01-27 13:19:55 +0100 | [diff] [blame] | 34 | static const struct osmo_tdef_state_timeout tbf_dl_ass_fsm_timeouts[32] = { |
Pau Espin Pedrol | 49a2f40 | 2021-07-27 17:33:07 +0200 | [diff] [blame] | 35 | [TBF_DL_ASS_NONE] = {}, |
| 36 | [TBF_DL_ASS_SEND_ASS] = {}, |
| 37 | [TBF_DL_ASS_WAIT_ACK] = {}, |
| 38 | }; |
| 39 | |
Pau Espin Pedrol | 76ef666 | 2023-01-27 13:19:55 +0100 | [diff] [blame] | 40 | static const struct value_string tbf_dl_ass_fsm_event_names[] = { |
Pau Espin Pedrol | 49a2f40 | 2021-07-27 17:33:07 +0200 | [diff] [blame] | 41 | { TBF_DL_ASS_EV_SCHED_ASS, "SCHED_ASS" }, |
| 42 | { TBF_DL_ASS_EV_CREATE_RLCMAC_MSG, "CREATE_RLCMAC_MSG" }, |
| 43 | { TBF_DL_ASS_EV_RX_ASS_CTRL_ACK, "RX_ASS_CTRL_ACK" }, |
| 44 | { TBF_DL_ASS_EV_ASS_POLL_TIMEOUT, "ASS_POLL_TIMEOUT" }, |
| 45 | { 0, NULL } |
| 46 | }; |
| 47 | |
Pau Espin Pedrol | 76ef666 | 2023-01-27 13:19:55 +0100 | [diff] [blame] | 48 | /* Transition to a state, using the T timer defined in tbf_dl_ass_fsm_timeouts. |
| 49 | * The actual timeout value is in turn obtained from conn->T_defs. |
| 50 | * Assumes local variable fi exists. */ |
| 51 | #define tbf_dl_ass_fsm_state_chg(fi, NEXT_STATE) \ |
| 52 | osmo_tdef_fsm_inst_state_chg(fi, NEXT_STATE, \ |
| 53 | tbf_dl_ass_fsm_timeouts, \ |
| 54 | the_pcu->T_defs, \ |
| 55 | -1) |
| 56 | |
| 57 | static struct msgb *create_packet_dl_assign(const struct tbf_dl_ass_fsm_ctx *ctx, |
Pau Espin Pedrol | 49a2f40 | 2021-07-27 17:33:07 +0200 | [diff] [blame] | 58 | const struct tbf_dl_ass_ev_create_rlcmac_msg_ctx *d) |
| 59 | { |
| 60 | struct msgb *msg; |
| 61 | struct gprs_rlcmac_dl_tbf *new_dl_tbf = NULL; |
| 62 | RlcMacDownlink_t *mac_control_block = NULL; |
| 63 | struct GprsMs *ms = tbf_ms(ctx->tbf); |
| 64 | const int poll_ass_dl = 1; |
| 65 | unsigned int rrbp = 0; |
| 66 | uint32_t new_poll_fn = 0; |
| 67 | int rc; |
| 68 | bool old_tfi_is_valid = tbf_is_tfi_assigned(ctx->tbf); |
| 69 | |
| 70 | /* We only use this function in control TS (PACCH) so that MS can always answer the poll */ |
Pau Espin Pedrol | 5ba3ef9 | 2022-12-12 18:02:25 +0100 | [diff] [blame] | 71 | OSMO_ASSERT(tbf_is_control_ts(ctx->tbf, d->pdch)); |
Pau Espin Pedrol | 49a2f40 | 2021-07-27 17:33:07 +0200 | [diff] [blame] | 72 | |
Pau Espin Pedrol | fd74e79 | 2022-12-15 18:23:12 +0100 | [diff] [blame] | 73 | rc = tbf_check_polling(ctx->tbf, d->pdch, d->fn, &new_poll_fn, &rrbp); |
Pau Espin Pedrol | 49a2f40 | 2021-07-27 17:33:07 +0200 | [diff] [blame] | 74 | if (rc < 0) |
| 75 | return NULL; |
| 76 | |
Pau Espin Pedrol | 49a2f40 | 2021-07-27 17:33:07 +0200 | [diff] [blame] | 77 | new_dl_tbf = ms_dl_tbf(ms); |
| 78 | if (!new_dl_tbf) { |
| 79 | LOGPTBF(ctx->tbf, LOGL_ERROR, |
| 80 | "We have a schedule for downlink assignment, but there is no downlink TBF\n"); |
| 81 | tbf_dl_ass_fsm_state_chg(ctx->fi, TBF_DL_ASS_NONE); |
| 82 | return NULL; |
| 83 | } |
| 84 | |
Pau Espin Pedrol | 49a2f40 | 2021-07-27 17:33:07 +0200 | [diff] [blame] | 85 | if (old_tfi_is_valid && ms_tlli(ms) == GSM_RESERVED_TMSI) { |
| 86 | LOGPTBF(ctx->tbf, LOGL_ERROR, |
| 87 | "The old TFI is not assigned and there is no TLLI. New TBF %s\n", |
| 88 | tbf_name((struct gprs_rlcmac_tbf *)new_dl_tbf)); |
| 89 | tbf_dl_ass_fsm_state_chg(ctx->fi, TBF_DL_ASS_NONE); |
| 90 | return NULL; |
| 91 | } |
| 92 | |
| 93 | msg = msgb_alloc(GSM_MACBLOCK_LEN, "rlcmac_dl_ass"); |
| 94 | if (!msg) |
| 95 | return NULL; |
| 96 | |
| 97 | /* Initialize a bit vector that uses allocated msgb as the data buffer. */ |
| 98 | struct bitvec bv = { |
| 99 | .data = msgb_put(msg, GSM_MACBLOCK_LEN), |
| 100 | .data_len = GSM_MACBLOCK_LEN, |
| 101 | }; |
| 102 | bitvec_unhex(&bv, DUMMY_VEC); |
| 103 | |
Pau Espin Pedrol | 84f2b51 | 2021-11-11 13:28:46 +0100 | [diff] [blame] | 104 | if (ctx->tbf != (struct gprs_rlcmac_tbf *)new_dl_tbf) |
Pau Espin Pedrol | 17bfbed | 2021-11-12 13:12:48 +0100 | [diff] [blame] | 105 | LOGPTBF(ctx->tbf, LOGL_INFO, "start Packet Downlink Assignment (PACCH) for %s\n", |
Pau Espin Pedrol | 84f2b51 | 2021-11-11 13:28:46 +0100 | [diff] [blame] | 106 | tbf_name((const struct gprs_rlcmac_tbf *)new_dl_tbf)); |
| 107 | else |
Pau Espin Pedrol | 17bfbed | 2021-11-12 13:12:48 +0100 | [diff] [blame] | 108 | LOGPTBF(ctx->tbf, LOGL_INFO, "start Packet Downlink Assignment (PACCH)\n"); |
Pau Espin Pedrol | 84f2b51 | 2021-11-11 13:28:46 +0100 | [diff] [blame] | 109 | |
Pau Espin Pedrol | 49a2f40 | 2021-07-27 17:33:07 +0200 | [diff] [blame] | 110 | mac_control_block = (RlcMacDownlink_t *)talloc_zero(ctx->tbf, RlcMacDownlink_t); |
| 111 | write_packet_downlink_assignment(mac_control_block, old_tfi_is_valid, |
| 112 | tbf_tfi(ctx->tbf), (tbf_direction(ctx->tbf) == GPRS_RLCMAC_DL_TBF), |
| 113 | new_dl_tbf, poll_ass_dl, rrbp, |
| 114 | bts_get_ms_pwr_alpha(ms->bts), the_pcu->vty.gamma, -1, 0, |
| 115 | tbf_is_egprs_enabled(ctx->tbf), tbf_state(ctx->tbf) == TBF_ST_WAIT_RELEASE); |
| 116 | LOGP(DTBF, LOGL_DEBUG, "+++++++++++++++++++++++++ TX : Packet Downlink Assignment +++++++++++++++++++++++++\n"); |
| 117 | rc = encode_gsm_rlcmac_downlink(&bv, mac_control_block); |
| 118 | if (rc < 0) { |
| 119 | LOGP(DTBF, LOGL_ERROR, "Encoding of Packet Downlink Ass failed (%d)\n", rc); |
| 120 | goto free_ret; |
| 121 | } |
| 122 | LOGP(DTBF, LOGL_DEBUG, "------------------------- TX : Packet Downlink Assignment -------------------------\n"); |
| 123 | bts_do_rate_ctr_inc(ms->bts, CTR_PKT_DL_ASSIGNMENT); |
| 124 | |
Pau Espin Pedrol | 5b7eeec | 2022-12-15 19:08:13 +0100 | [diff] [blame] | 125 | tbf_set_polling(ctx->tbf, d->pdch, new_poll_fn, PDCH_ULC_POLL_DL_ASS); |
Pau Espin Pedrol | bd1f01f | 2022-10-27 15:19:39 +0200 | [diff] [blame] | 126 | LOGPTBF(ctx->tbf, LOGL_INFO, "Scheduled DL Assignment polling on PACCH (FN=%d, TS=%d)\n", |
Pau Espin Pedrol | 5ba3ef9 | 2022-12-12 18:02:25 +0100 | [diff] [blame] | 127 | new_poll_fn, d->pdch->ts_no); |
Pau Espin Pedrol | 49a2f40 | 2021-07-27 17:33:07 +0200 | [diff] [blame] | 128 | |
| 129 | talloc_free(mac_control_block); |
| 130 | return msg; |
| 131 | |
| 132 | free_ret: |
| 133 | talloc_free(mac_control_block); |
| 134 | msgb_free(msg); |
| 135 | return NULL; |
| 136 | } |
| 137 | |
| 138 | static void st_none_on_enter(struct osmo_fsm_inst *fi, uint32_t prev_state) |
| 139 | { |
| 140 | } |
| 141 | |
| 142 | static void st_none(struct osmo_fsm_inst *fi, uint32_t event, void *data) |
| 143 | { |
| 144 | switch (event) { |
| 145 | case TBF_DL_ASS_EV_SCHED_ASS: |
| 146 | tbf_dl_ass_fsm_state_chg(fi, TBF_DL_ASS_SEND_ASS); |
| 147 | break; |
| 148 | default: |
| 149 | OSMO_ASSERT(0); |
| 150 | } |
| 151 | } |
| 152 | |
| 153 | static void st_send_ass(struct osmo_fsm_inst *fi, uint32_t event, void *data) |
| 154 | { |
| 155 | struct tbf_dl_ass_fsm_ctx *ctx = (struct tbf_dl_ass_fsm_ctx *)fi->priv; |
| 156 | struct tbf_dl_ass_ev_create_rlcmac_msg_ctx *data_ctx; |
| 157 | |
| 158 | switch (event) { |
| 159 | case TBF_DL_ASS_EV_CREATE_RLCMAC_MSG: |
| 160 | data_ctx = (struct tbf_dl_ass_ev_create_rlcmac_msg_ctx *)data; |
| 161 | data_ctx->msg = create_packet_dl_assign(ctx, data_ctx); |
| 162 | if (!data_ctx->msg) |
| 163 | return; |
| 164 | tbf_dl_ass_fsm_state_chg(fi, TBF_DL_ASS_WAIT_ACK); |
| 165 | break; |
| 166 | default: |
| 167 | OSMO_ASSERT(0); |
| 168 | } |
| 169 | } |
| 170 | |
| 171 | static void st_wait_ack(struct osmo_fsm_inst *fi, uint32_t event, void *data) |
| 172 | { |
Pau Espin Pedrol | 5bc6560 | 2021-07-27 18:09:58 +0200 | [diff] [blame] | 173 | struct tbf_dl_ass_fsm_ctx *ctx = (struct tbf_dl_ass_fsm_ctx *)fi->priv; |
| 174 | |
Pau Espin Pedrol | 49a2f40 | 2021-07-27 17:33:07 +0200 | [diff] [blame] | 175 | switch (event) { |
| 176 | case TBF_DL_ASS_EV_RX_ASS_CTRL_ACK: |
| 177 | tbf_dl_ass_fsm_state_chg(fi, TBF_DL_ASS_NONE); |
| 178 | break; |
| 179 | case TBF_DL_ASS_EV_ASS_POLL_TIMEOUT: |
Pau Espin Pedrol | 5bc6560 | 2021-07-27 18:09:58 +0200 | [diff] [blame] | 180 | LOGPTBF(ctx->tbf, LOGL_NOTICE, |
| 181 | "Timeout for polling PACKET CONTROL ACK for PACKET DOWNLINK ASSIGNMENT: %s\n", |
| 182 | tbf_rlcmac_diag(ctx->tbf)); |
Pau Espin Pedrol | 49a2f40 | 2021-07-27 17:33:07 +0200 | [diff] [blame] | 183 | /* Reschedule Pkt Dl Ass */ |
| 184 | tbf_dl_ass_fsm_state_chg(fi, TBF_DL_ASS_SEND_ASS); |
| 185 | break; |
| 186 | default: |
| 187 | OSMO_ASSERT(0); |
| 188 | } |
| 189 | } |
| 190 | |
| 191 | static int tbf_dl_ass_fsm_timer_cb(struct osmo_fsm_inst *fi) |
| 192 | { |
Pau Espin Pedrol | 49a2f40 | 2021-07-27 17:33:07 +0200 | [diff] [blame] | 193 | switch (fi->T) { |
Pau Espin Pedrol | 49a2f40 | 2021-07-27 17:33:07 +0200 | [diff] [blame] | 194 | default: |
| 195 | OSMO_ASSERT(0); |
| 196 | } |
| 197 | return 0; |
| 198 | } |
| 199 | |
| 200 | static struct osmo_fsm_state tbf_dl_ass_fsm_states[] = { |
| 201 | [TBF_DL_ASS_NONE] = { |
| 202 | .in_event_mask = |
| 203 | X(TBF_DL_ASS_EV_SCHED_ASS), |
| 204 | .out_state_mask = |
| 205 | X(TBF_DL_ASS_SEND_ASS), |
| 206 | .name = "NONE", |
| 207 | .action = st_none, |
| 208 | .onenter = st_none_on_enter, |
| 209 | }, |
| 210 | [TBF_DL_ASS_SEND_ASS] = { |
| 211 | .in_event_mask = X(TBF_DL_ASS_EV_CREATE_RLCMAC_MSG), |
Pau Espin Pedrol | bd1b90f | 2021-11-11 13:19:54 +0100 | [diff] [blame] | 212 | .out_state_mask = |
| 213 | X(TBF_DL_ASS_WAIT_ACK) | |
| 214 | X(TBF_DL_ASS_NONE), |
Pau Espin Pedrol | 49a2f40 | 2021-07-27 17:33:07 +0200 | [diff] [blame] | 215 | .name = "SEND_ASS", |
| 216 | .action = st_send_ass, |
| 217 | }, |
| 218 | [TBF_DL_ASS_WAIT_ACK] = { |
| 219 | .in_event_mask = |
| 220 | X(TBF_DL_ASS_EV_RX_ASS_CTRL_ACK) | |
| 221 | X(TBF_DL_ASS_EV_ASS_POLL_TIMEOUT), |
| 222 | .out_state_mask = |
| 223 | X(TBF_DL_ASS_NONE) | |
| 224 | X(TBF_DL_ASS_SEND_ASS), |
| 225 | .name = "WAIT_ACK", |
| 226 | .action = st_wait_ack, |
| 227 | }, |
| 228 | }; |
| 229 | |
| 230 | struct osmo_fsm tbf_dl_ass_fsm = { |
| 231 | .name = "DL_ASS_TBF", |
| 232 | .states = tbf_dl_ass_fsm_states, |
| 233 | .num_states = ARRAY_SIZE(tbf_dl_ass_fsm_states), |
| 234 | .timer_cb = tbf_dl_ass_fsm_timer_cb, |
| 235 | .log_subsys = DTBF, |
| 236 | .event_names = tbf_dl_ass_fsm_event_names, |
| 237 | }; |
| 238 | |
| 239 | static __attribute__((constructor)) void tbf_dl_ass_fsm_init(void) |
| 240 | { |
| 241 | OSMO_ASSERT(osmo_fsm_register(&tbf_dl_ass_fsm) == 0); |
| 242 | } |
| 243 | |
| 244 | |
Pau Espin Pedrol | 5ba3ef9 | 2022-12-12 18:02:25 +0100 | [diff] [blame] | 245 | struct msgb *tbf_dl_ass_create_rlcmac_msg(const struct gprs_rlcmac_tbf *tbf, |
| 246 | const struct gprs_rlcmac_pdch *pdch, |
| 247 | uint32_t fn) |
Pau Espin Pedrol | 49a2f40 | 2021-07-27 17:33:07 +0200 | [diff] [blame] | 248 | { |
| 249 | int rc; |
| 250 | struct tbf_dl_ass_ev_create_rlcmac_msg_ctx data_ctx = { |
Pau Espin Pedrol | 5ba3ef9 | 2022-12-12 18:02:25 +0100 | [diff] [blame] | 251 | .pdch = pdch, |
Pau Espin Pedrol | 49a2f40 | 2021-07-27 17:33:07 +0200 | [diff] [blame] | 252 | .fn = fn, |
Pau Espin Pedrol | 49a2f40 | 2021-07-27 17:33:07 +0200 | [diff] [blame] | 253 | .msg = NULL, |
| 254 | }; |
| 255 | |
| 256 | rc = osmo_fsm_inst_dispatch(tbf_dl_ass_fi(tbf), TBF_DL_ASS_EV_CREATE_RLCMAC_MSG, &data_ctx); |
| 257 | if (rc != 0 || !data_ctx.msg) |
| 258 | return NULL; |
| 259 | return data_ctx.msg; |
| 260 | } |
| 261 | |
Pau Espin Pedrol | 106f2a0 | 2022-12-12 17:29:10 +0100 | [diff] [blame] | 262 | bool tbf_dl_ass_rts(const struct gprs_rlcmac_tbf *tbf, const struct gprs_rlcmac_pdch *pdch) |
Pau Espin Pedrol | 49a2f40 | 2021-07-27 17:33:07 +0200 | [diff] [blame] | 263 | { |
Pau Espin Pedrol | 106f2a0 | 2022-12-12 17:29:10 +0100 | [diff] [blame] | 264 | struct osmo_fsm_inst *fi; |
| 265 | |
| 266 | if (!tbf_is_control_ts(tbf, pdch)) |
| 267 | return false; |
| 268 | |
| 269 | fi = tbf_dl_ass_fi(tbf); |
Pau Espin Pedrol | 78ddfbc | 2021-10-12 13:08:27 +0200 | [diff] [blame] | 270 | if (fi->state != TBF_DL_ASS_SEND_ASS) |
| 271 | return false; |
| 272 | |
| 273 | if (tbf_ul_ass_fi(tbf)->state == TBF_UL_ASS_WAIT_ACK) { |
| 274 | LOGPTBF(tbf, LOGL_DEBUG, |
| 275 | "Polling is already scheduled, so we must wait for the uplink assignment...\n"); |
| 276 | return false; |
| 277 | } |
| 278 | |
| 279 | /* on uplink TBF we get the downlink TBF to be assigned. */ |
| 280 | if (tbf_direction(tbf) == GPRS_RLCMAC_UL_TBF) { |
| 281 | const struct gprs_rlcmac_ul_tbf *ul_tbf = (const struct gprs_rlcmac_ul_tbf *)tbf; |
| 282 | /* be sure to check first, if contention resolution is done, |
| 283 | * otherwise we cannot send the assignment yet (3GPP TS 44.060 sec 7.1.3.1) */ |
| 284 | if (!ul_tbf_contention_resolution_done(ul_tbf)) { |
| 285 | LOGPTBF(tbf, LOGL_DEBUG, |
| 286 | "Cannot assign DL TBF now, because contention resolution is not finished.\n"); |
| 287 | return false; |
| 288 | } |
| 289 | } |
| 290 | return true; |
Pau Espin Pedrol | 49a2f40 | 2021-07-27 17:33:07 +0200 | [diff] [blame] | 291 | } |