| /* tbf_dl_ass_fsm.c |
| * |
| * Copyright (C) 2021 by sysmocom - s.f.m.c. GmbH <info@sysmocom.de> |
| * Author: Pau Espin Pedrol <pespin@sysmocom.de> |
| * |
| * 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. |
| */ |
| |
| #include <unistd.h> |
| |
| #include <talloc.h> |
| |
| #include <osmocom/core/bitvec.h> |
| |
| #include <tbf_dl_ass_fsm.h> |
| #include <gprs_rlcmac.h> |
| #include <gprs_debug.h> |
| #include <gprs_ms.h> |
| #include <encoding.h> |
| #include <bts.h> |
| #include <tbf.h> |
| #include <tbf_dl.h> |
| |
| #define X(s) (1 << (s)) |
| |
| const struct osmo_tdef_state_timeout tbf_dl_ass_fsm_timeouts[32] = { |
| [TBF_DL_ASS_NONE] = {}, |
| [TBF_DL_ASS_SEND_ASS] = {}, |
| [TBF_DL_ASS_WAIT_ACK] = {}, |
| }; |
| |
| const struct value_string tbf_dl_ass_fsm_event_names[] = { |
| { TBF_DL_ASS_EV_SCHED_ASS, "SCHED_ASS" }, |
| { TBF_DL_ASS_EV_CREATE_RLCMAC_MSG, "CREATE_RLCMAC_MSG" }, |
| { TBF_DL_ASS_EV_RX_ASS_CTRL_ACK, "RX_ASS_CTRL_ACK" }, |
| { TBF_DL_ASS_EV_ASS_POLL_TIMEOUT, "ASS_POLL_TIMEOUT" }, |
| { 0, NULL } |
| }; |
| |
| struct msgb *create_packet_dl_assign(const struct tbf_dl_ass_fsm_ctx *ctx, |
| const struct tbf_dl_ass_ev_create_rlcmac_msg_ctx *d) |
| { |
| struct msgb *msg; |
| struct gprs_rlcmac_dl_tbf *new_dl_tbf = NULL; |
| RlcMacDownlink_t *mac_control_block = NULL; |
| struct GprsMs *ms = tbf_ms(ctx->tbf); |
| const int poll_ass_dl = 1; |
| unsigned int rrbp = 0; |
| uint32_t new_poll_fn = 0; |
| int rc; |
| bool old_tfi_is_valid = tbf_is_tfi_assigned(ctx->tbf); |
| |
| /* We only use this function in control TS (PACCH) so that MS can always answer the poll */ |
| OSMO_ASSERT(tbf_is_control_ts(ctx->tbf, d->pdch)); |
| |
| rc = tbf_check_polling(ctx->tbf, d->fn, d->pdch->ts_no, &new_poll_fn, &rrbp); |
| if (rc < 0) |
| return NULL; |
| |
| new_dl_tbf = ms_dl_tbf(ms); |
| if (!new_dl_tbf) { |
| LOGPTBF(ctx->tbf, LOGL_ERROR, |
| "We have a schedule for downlink assignment, but there is no downlink TBF\n"); |
| tbf_dl_ass_fsm_state_chg(ctx->fi, TBF_DL_ASS_NONE); |
| return NULL; |
| } |
| |
| if (old_tfi_is_valid && ms_tlli(ms) == GSM_RESERVED_TMSI) { |
| LOGPTBF(ctx->tbf, LOGL_ERROR, |
| "The old TFI is not assigned and there is no TLLI. New TBF %s\n", |
| tbf_name((struct gprs_rlcmac_tbf *)new_dl_tbf)); |
| tbf_dl_ass_fsm_state_chg(ctx->fi, TBF_DL_ASS_NONE); |
| return NULL; |
| } |
| |
| msg = msgb_alloc(GSM_MACBLOCK_LEN, "rlcmac_dl_ass"); |
| if (!msg) |
| return NULL; |
| |
| /* Initialize a bit vector that uses allocated msgb as the data buffer. */ |
| struct bitvec bv = { |
| .data = msgb_put(msg, GSM_MACBLOCK_LEN), |
| .data_len = GSM_MACBLOCK_LEN, |
| }; |
| bitvec_unhex(&bv, DUMMY_VEC); |
| |
| if (ctx->tbf != (struct gprs_rlcmac_tbf *)new_dl_tbf) |
| LOGPTBF(ctx->tbf, LOGL_INFO, "start Packet Downlink Assignment (PACCH) for %s\n", |
| tbf_name((const struct gprs_rlcmac_tbf *)new_dl_tbf)); |
| else |
| LOGPTBF(ctx->tbf, LOGL_INFO, "start Packet Downlink Assignment (PACCH)\n"); |
| |
| mac_control_block = (RlcMacDownlink_t *)talloc_zero(ctx->tbf, RlcMacDownlink_t); |
| write_packet_downlink_assignment(mac_control_block, old_tfi_is_valid, |
| tbf_tfi(ctx->tbf), (tbf_direction(ctx->tbf) == GPRS_RLCMAC_DL_TBF), |
| new_dl_tbf, poll_ass_dl, rrbp, |
| bts_get_ms_pwr_alpha(ms->bts), the_pcu->vty.gamma, -1, 0, |
| tbf_is_egprs_enabled(ctx->tbf), tbf_state(ctx->tbf) == TBF_ST_WAIT_RELEASE); |
| LOGP(DTBF, LOGL_DEBUG, "+++++++++++++++++++++++++ TX : Packet Downlink Assignment +++++++++++++++++++++++++\n"); |
| rc = encode_gsm_rlcmac_downlink(&bv, mac_control_block); |
| if (rc < 0) { |
| LOGP(DTBF, LOGL_ERROR, "Encoding of Packet Downlink Ass failed (%d)\n", rc); |
| goto free_ret; |
| } |
| LOGP(DTBF, LOGL_DEBUG, "------------------------- TX : Packet Downlink Assignment -------------------------\n"); |
| bts_do_rate_ctr_inc(ms->bts, CTR_PKT_DL_ASSIGNMENT); |
| |
| tbf_set_polling(ctx->tbf, new_poll_fn, d->pdch->ts_no, PDCH_ULC_POLL_DL_ASS); |
| LOGPTBF(ctx->tbf, LOGL_INFO, "Scheduled DL Assignment polling on PACCH (FN=%d, TS=%d)\n", |
| new_poll_fn, d->pdch->ts_no); |
| |
| talloc_free(mac_control_block); |
| return msg; |
| |
| free_ret: |
| talloc_free(mac_control_block); |
| msgb_free(msg); |
| return NULL; |
| } |
| |
| static void st_none_on_enter(struct osmo_fsm_inst *fi, uint32_t prev_state) |
| { |
| } |
| |
| static void st_none(struct osmo_fsm_inst *fi, uint32_t event, void *data) |
| { |
| switch (event) { |
| case TBF_DL_ASS_EV_SCHED_ASS: |
| tbf_dl_ass_fsm_state_chg(fi, TBF_DL_ASS_SEND_ASS); |
| break; |
| default: |
| OSMO_ASSERT(0); |
| } |
| } |
| |
| static void st_send_ass(struct osmo_fsm_inst *fi, uint32_t event, void *data) |
| { |
| struct tbf_dl_ass_fsm_ctx *ctx = (struct tbf_dl_ass_fsm_ctx *)fi->priv; |
| struct tbf_dl_ass_ev_create_rlcmac_msg_ctx *data_ctx; |
| |
| switch (event) { |
| case TBF_DL_ASS_EV_CREATE_RLCMAC_MSG: |
| data_ctx = (struct tbf_dl_ass_ev_create_rlcmac_msg_ctx *)data; |
| data_ctx->msg = create_packet_dl_assign(ctx, data_ctx); |
| if (!data_ctx->msg) |
| return; |
| tbf_dl_ass_fsm_state_chg(fi, TBF_DL_ASS_WAIT_ACK); |
| break; |
| default: |
| OSMO_ASSERT(0); |
| } |
| } |
| |
| static void st_wait_ack(struct osmo_fsm_inst *fi, uint32_t event, void *data) |
| { |
| struct tbf_dl_ass_fsm_ctx *ctx = (struct tbf_dl_ass_fsm_ctx *)fi->priv; |
| |
| switch (event) { |
| case TBF_DL_ASS_EV_RX_ASS_CTRL_ACK: |
| tbf_dl_ass_fsm_state_chg(fi, TBF_DL_ASS_NONE); |
| break; |
| case TBF_DL_ASS_EV_ASS_POLL_TIMEOUT: |
| LOGPTBF(ctx->tbf, LOGL_NOTICE, |
| "Timeout for polling PACKET CONTROL ACK for PACKET DOWNLINK ASSIGNMENT: %s\n", |
| tbf_rlcmac_diag(ctx->tbf)); |
| /* Reschedule Pkt Dl Ass */ |
| tbf_dl_ass_fsm_state_chg(fi, TBF_DL_ASS_SEND_ASS); |
| break; |
| default: |
| OSMO_ASSERT(0); |
| } |
| } |
| |
| static int tbf_dl_ass_fsm_timer_cb(struct osmo_fsm_inst *fi) |
| { |
| switch (fi->T) { |
| default: |
| OSMO_ASSERT(0); |
| } |
| return 0; |
| } |
| |
| static struct osmo_fsm_state tbf_dl_ass_fsm_states[] = { |
| [TBF_DL_ASS_NONE] = { |
| .in_event_mask = |
| X(TBF_DL_ASS_EV_SCHED_ASS), |
| .out_state_mask = |
| X(TBF_DL_ASS_SEND_ASS), |
| .name = "NONE", |
| .action = st_none, |
| .onenter = st_none_on_enter, |
| }, |
| [TBF_DL_ASS_SEND_ASS] = { |
| .in_event_mask = X(TBF_DL_ASS_EV_CREATE_RLCMAC_MSG), |
| .out_state_mask = |
| X(TBF_DL_ASS_WAIT_ACK) | |
| X(TBF_DL_ASS_NONE), |
| .name = "SEND_ASS", |
| .action = st_send_ass, |
| }, |
| [TBF_DL_ASS_WAIT_ACK] = { |
| .in_event_mask = |
| X(TBF_DL_ASS_EV_RX_ASS_CTRL_ACK) | |
| X(TBF_DL_ASS_EV_ASS_POLL_TIMEOUT), |
| .out_state_mask = |
| X(TBF_DL_ASS_NONE) | |
| X(TBF_DL_ASS_SEND_ASS), |
| .name = "WAIT_ACK", |
| .action = st_wait_ack, |
| }, |
| }; |
| |
| struct osmo_fsm tbf_dl_ass_fsm = { |
| .name = "DL_ASS_TBF", |
| .states = tbf_dl_ass_fsm_states, |
| .num_states = ARRAY_SIZE(tbf_dl_ass_fsm_states), |
| .timer_cb = tbf_dl_ass_fsm_timer_cb, |
| .log_subsys = DTBF, |
| .event_names = tbf_dl_ass_fsm_event_names, |
| }; |
| |
| static __attribute__((constructor)) void tbf_dl_ass_fsm_init(void) |
| { |
| OSMO_ASSERT(osmo_fsm_register(&tbf_dl_ass_fsm) == 0); |
| } |
| |
| |
| struct msgb *tbf_dl_ass_create_rlcmac_msg(const struct gprs_rlcmac_tbf *tbf, |
| const struct gprs_rlcmac_pdch *pdch, |
| uint32_t fn) |
| { |
| int rc; |
| struct tbf_dl_ass_ev_create_rlcmac_msg_ctx data_ctx = { |
| .pdch = pdch, |
| .fn = fn, |
| .msg = NULL, |
| }; |
| |
| rc = osmo_fsm_inst_dispatch(tbf_dl_ass_fi(tbf), TBF_DL_ASS_EV_CREATE_RLCMAC_MSG, &data_ctx); |
| if (rc != 0 || !data_ctx.msg) |
| return NULL; |
| return data_ctx.msg; |
| } |
| |
| bool tbf_dl_ass_rts(const struct gprs_rlcmac_tbf *tbf, const struct gprs_rlcmac_pdch *pdch) |
| { |
| struct osmo_fsm_inst *fi; |
| |
| if (!tbf_is_control_ts(tbf, pdch)) |
| return false; |
| |
| fi = tbf_dl_ass_fi(tbf); |
| if (fi->state != TBF_DL_ASS_SEND_ASS) |
| return false; |
| |
| if (tbf_ul_ass_fi(tbf)->state == TBF_UL_ASS_WAIT_ACK) { |
| LOGPTBF(tbf, LOGL_DEBUG, |
| "Polling is already scheduled, so we must wait for the uplink assignment...\n"); |
| return false; |
| } |
| |
| /* on uplink TBF we get the downlink TBF to be assigned. */ |
| if (tbf_direction(tbf) == GPRS_RLCMAC_UL_TBF) { |
| const struct gprs_rlcmac_ul_tbf *ul_tbf = (const struct gprs_rlcmac_ul_tbf *)tbf; |
| /* be sure to check first, if contention resolution is done, |
| * otherwise we cannot send the assignment yet (3GPP TS 44.060 sec 7.1.3.1) */ |
| if (!ul_tbf_contention_resolution_done(ul_tbf)) { |
| LOGPTBF(tbf, LOGL_DEBUG, |
| "Cannot assign DL TBF now, because contention resolution is not finished.\n"); |
| return false; |
| } |
| } |
| return true; |
| } |