| /* tbf_ul_ack_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_ul_ack_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_ul.h> |
| |
| #include <tbf_ul_ack_fsm.h> |
| |
| #define X(s) (1 << (s)) |
| |
| const struct osmo_tdef_state_timeout tbf_ul_ack_fsm_timeouts[32] = { |
| [TBF_UL_ACK_ST_NONE] = {}, |
| [TBF_UL_ACK_ST_SCHED_UL_ACK] = {}, |
| [TBF_UL_ACK_ST_WAIT_ACK] = {}, |
| }; |
| |
| const struct value_string tbf_ul_ack_fsm_event_names[] = { |
| { TBF_UL_ACK_EV_SCHED_ACK, "SCHED_ACK" }, |
| { TBF_UL_ACK_EV_CREATE_RLCMAC_MSG, "CREATE_RLCMAC_MSG" }, |
| { TBF_UL_ACK_EV_RX_CTRL_ACK, "RX_CTRL_ACK" }, |
| { TBF_UL_ACK_EV_POLL_TIMEOUT, "POLL_TIMEOUT" }, |
| { 0, NULL } |
| }; |
| |
| static struct msgb *create_ul_ack_nack(const struct tbf_ul_ack_fsm_ctx *ctx, |
| const struct tbf_ul_ack_ev_create_rlcmac_msg_ctx *d, |
| bool final) |
| { |
| struct msgb *msg; |
| int rc; |
| unsigned int rrbp = 0; |
| uint32_t new_poll_fn = 0; |
| struct gprs_rlcmac_ul_tbf *tbf = ctx->tbf; |
| struct GprsMs *ms = tbf_ms(ul_tbf_as_tbf(tbf)); |
| |
| if (final) { |
| rc = tbf_check_polling(ul_tbf_as_tbf(tbf), d->fn, d->pdch->ts_no, &new_poll_fn, &rrbp); |
| if (rc < 0) |
| return NULL; |
| } |
| |
| msg = msgb_alloc(23, "rlcmac_ul_ack"); |
| if (!msg) |
| return NULL; |
| struct bitvec *ack_vec = bitvec_alloc(23, tbf); |
| if (!ack_vec) { |
| msgb_free(msg); |
| return NULL; |
| } |
| bitvec_unhex(ack_vec, DUMMY_VEC); |
| write_packet_uplink_ack(ack_vec, ctx->tbf, final, rrbp); |
| bitvec_pack(ack_vec, msgb_put(msg, 23)); |
| bitvec_free(ack_vec); |
| |
| /* TS 44.060 7a.2.1.1: "The contention resolution is completed on |
| * the network side when the network receives an RLC data block that |
| * comprises the TLLI value that identifies the mobile station and the |
| * TFI value associated with the TBF." (see TBF_EV_FIRST_UL_DATA_RECVD). |
| * |
| * However, it's handier for us to mark contention resolution success here |
| * since upon rx UL ACK is the time at which MS realizes contention resolution |
| * succeeds: |
| * TS 44.060 7.1.2.3: "The contention resolution is successfully completed |
| * on the mobile station side when the mobile station receives a |
| * PACKET UPLINK ACK/NACK" |
| */ |
| if (ms_tlli(ms) != GSM_RESERVED_TMSI && !ul_tbf_contention_resolution_done(ctx->tbf)) |
| osmo_fsm_inst_dispatch(tbf_state_fi(ul_tbf_as_tbf(ctx->tbf)), TBF_EV_CONTENTION_RESOLUTION_MS_SUCCESS, NULL); |
| |
| if (final) { |
| tbf_set_polling(ul_tbf_as_tbf(tbf), new_poll_fn, d->pdch->ts_no, PDCH_ULC_POLL_UL_ACK); |
| LOGPTBFUL(tbf, LOGL_DEBUG, |
| "Scheduled UL Acknowledgement polling on PACCH (FN=%d, TS=%d)\n", |
| new_poll_fn, d->pdch->ts_no); |
| } |
| |
| return msg; |
| } |
| |
| static void st_none(struct osmo_fsm_inst *fi, uint32_t event, void *data) |
| { |
| switch (event) { |
| case TBF_UL_ACK_EV_SCHED_ACK: |
| tbf_ul_ack_fsm_state_chg(fi, TBF_UL_ACK_ST_SCHED_UL_ACK); |
| break; |
| default: |
| OSMO_ASSERT(0); |
| } |
| } |
| |
| static void st_sched_ul_ack(struct osmo_fsm_inst *fi, uint32_t event, void *data) |
| { |
| struct tbf_ul_ack_fsm_ctx *ctx = (struct tbf_ul_ack_fsm_ctx *)fi->priv; |
| struct gprs_rlcmac_ul_tbf *tbf = ctx->tbf; |
| struct tbf_ul_ack_ev_create_rlcmac_msg_ctx *data_ctx; |
| bool final; |
| |
| switch (event) { |
| case TBF_UL_ACK_EV_SCHED_ACK: |
| LOGPTBFUL(tbf, LOGL_DEBUG, |
| "Sending Ack/Nack already scheduled, no need to re-schedule\n"); |
| break; |
| case TBF_UL_ACK_EV_CREATE_RLCMAC_MSG: |
| data_ctx = (struct tbf_ul_ack_ev_create_rlcmac_msg_ctx *)data; |
| final = tbf_state(ul_tbf_as_tbf(tbf)) == TBF_ST_FINISHED; |
| data_ctx->msg = create_ul_ack_nack(ctx, data_ctx, final); |
| if (!data_ctx->msg) |
| return; |
| if (final) /* poll set */ |
| tbf_ul_ack_fsm_state_chg(fi, TBF_UL_ACK_ST_WAIT_ACK); |
| else |
| tbf_ul_ack_fsm_state_chg(fi, TBF_UL_ACK_ST_NONE); |
| break; |
| default: |
| OSMO_ASSERT(0); |
| } |
| } |
| |
| static void st_wait_ctrl_ack(struct osmo_fsm_inst *fi, uint32_t event, void *data) |
| { |
| struct tbf_ul_ack_fsm_ctx *ctx = (struct tbf_ul_ack_fsm_ctx *)fi->priv; |
| struct gprs_rlcmac_ul_tbf *tbf = ctx->tbf; |
| |
| switch (event) { |
| case TBF_UL_ACK_EV_SCHED_ACK: |
| /* ignore, we are in the middle of waiting for a response */ |
| break; |
| case TBF_UL_ACK_EV_RX_CTRL_ACK: |
| tbf_ul_ack_fsm_state_chg(fi, TBF_UL_ACK_ST_NONE); |
| break; |
| case TBF_UL_ACK_EV_POLL_TIMEOUT: |
| LOGPTBFUL(tbf, LOGL_NOTICE, |
| "Timeout for polling PACKET CONTROL ACK for PACKET UPLINK ACK: %s\n", |
| tbf_rlcmac_diag(ul_tbf_as_tbf(tbf))); |
| /* Reschedule Ul Ack/NAck */ |
| tbf_ul_ack_fsm_state_chg(fi, TBF_UL_ACK_ST_SCHED_UL_ACK); |
| break; |
| default: |
| OSMO_ASSERT(0); |
| } |
| } |
| |
| static int tbf_ul_ack_fsm_timer_cb(struct osmo_fsm_inst *fi) |
| { |
| switch (fi->T) { |
| default: |
| OSMO_ASSERT(0); |
| } |
| return 0; |
| } |
| |
| static struct osmo_fsm_state tbf_ul_ack_fsm_states[] = { |
| [TBF_UL_ACK_ST_NONE] = { |
| .in_event_mask = |
| X(TBF_UL_ACK_EV_SCHED_ACK), |
| .out_state_mask = |
| X(TBF_UL_ACK_ST_SCHED_UL_ACK), |
| .name = "NONE", |
| .action = st_none, |
| }, |
| [TBF_UL_ACK_ST_SCHED_UL_ACK] = { |
| .in_event_mask = |
| X(TBF_UL_ACK_EV_SCHED_ACK) | |
| X(TBF_UL_ACK_EV_CREATE_RLCMAC_MSG), |
| .out_state_mask = |
| X(TBF_UL_ACK_ST_NONE) | |
| X(TBF_UL_ACK_ST_WAIT_ACK), |
| .name = "SCHED_UL_ACK", |
| .action = st_sched_ul_ack, |
| }, |
| [TBF_UL_ACK_ST_WAIT_ACK] = { |
| .in_event_mask = |
| X(TBF_UL_ACK_EV_SCHED_ACK) | |
| X(TBF_UL_ACK_EV_RX_CTRL_ACK) | |
| X(TBF_UL_ACK_EV_POLL_TIMEOUT), |
| .out_state_mask = |
| X(TBF_UL_ACK_ST_NONE) | |
| X(TBF_UL_ACK_ST_SCHED_UL_ACK), |
| .name = "WAIT_ACK", |
| .action = st_wait_ctrl_ack, |
| }, |
| }; |
| |
| struct osmo_fsm tbf_ul_ack_fsm = { |
| .name = "UL_ACK_TBF", |
| .states = tbf_ul_ack_fsm_states, |
| .num_states = ARRAY_SIZE(tbf_ul_ack_fsm_states), |
| .timer_cb = tbf_ul_ack_fsm_timer_cb, |
| .log_subsys = DTBFUL, |
| .event_names = tbf_ul_ack_fsm_event_names, |
| }; |
| |
| static __attribute__((constructor)) void tbf_ul_ack_fsm_init(void) |
| { |
| OSMO_ASSERT(osmo_fsm_register(&tbf_ul_ack_fsm) == 0); |
| } |
| |
| |
| struct msgb *tbf_ul_ack_create_rlcmac_msg(const struct gprs_rlcmac_ul_tbf *ul_tbf, |
| const struct gprs_rlcmac_pdch *pdch, |
| uint32_t fn) |
| { |
| int rc; |
| struct tbf_ul_ack_ev_create_rlcmac_msg_ctx data_ctx = { |
| .pdch = pdch, |
| .fn = fn, |
| .msg = NULL, |
| }; |
| |
| rc = osmo_fsm_inst_dispatch(tbf_ul_ack_fi(ul_tbf), TBF_UL_ACK_EV_CREATE_RLCMAC_MSG, &data_ctx); |
| if (rc != 0 || !data_ctx.msg) |
| return NULL; |
| return data_ctx.msg; |
| } |
| |
| bool tbf_ul_ack_rts(const struct gprs_rlcmac_ul_tbf *ul_tbf, const struct gprs_rlcmac_pdch *pdch) |
| { |
| struct osmo_fsm_inst *fi; |
| |
| if (!tbf_is_control_ts(ul_tbf_as_tbf_const(ul_tbf), pdch)) |
| return false; |
| |
| fi = tbf_ul_ack_fi(ul_tbf); |
| return fi->state == TBF_UL_ACK_ST_SCHED_UL_ACK; |
| } |
| |
| /* Did we already send the Final ACK and we are waiting for its confirmation (CTRL ACK) ? */ |
| bool tbf_ul_ack_waiting_cnf_final_ack(const struct gprs_rlcmac_ul_tbf *ul_tbf) |
| { |
| struct osmo_fsm_inst *fi = tbf_ul_ack_fi(ul_tbf); |
| return fi->state == TBF_UL_ACK_ST_WAIT_ACK; |
| } |
| |
| bool tbf_ul_ack_exp_ctrl_ack(const struct gprs_rlcmac_ul_tbf *ul_tbf, uint32_t fn, uint8_t ts) |
| { |
| struct osmo_fsm_inst *fi = tbf_ul_ack_fi(ul_tbf); |
| return fi->state == TBF_UL_ACK_ST_WAIT_ACK; |
| /* FIXME: validate FN and TS match: && ctx->poll_fn = fn && ctx->poll_ts == ts */ |
| } |