| /* tbf_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. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| */ |
| |
| #include <unistd.h> |
| |
| #include <talloc.h> |
| |
| #include <tbf_fsm.h> |
| #include <gprs_rlcmac.h> |
| #include <gprs_debug.h> |
| #include <gprs_ms.h> |
| #include <encoding.h> |
| #include <bts.h> |
| |
| #define X(s) (1 << (s)) |
| |
| const struct osmo_tdef_state_timeout tbf_fsm_timeouts[32] = { |
| [TBF_ST_NEW] = {}, |
| [TBF_ST_ASSIGN] = { }, |
| [TBF_ST_FLOW] = { }, |
| [TBF_ST_FINISHED] = {}, |
| [TBF_ST_WAIT_RELEASE] = {}, |
| [TBF_ST_RELEASING] = {}, |
| }; |
| |
| const struct value_string tbf_fsm_event_names[] = { |
| { TBF_EV_ASSIGN_ADD_CCCH, "ASSIGN_ADD_CCCH" }, |
| { TBF_EV_ASSIGN_ADD_PACCH, "ASSIGN_ADD_PACCH" }, |
| { TBF_EV_ASSIGN_ACK_PACCH, "ASSIGN_ACK_PACCH" }, |
| { TBF_EV_ASSIGN_READY_CCCH, "ASSIGN_READY_CCCH" }, |
| { TBF_EV_ASSIGN_PCUIF_CNF, "ASSIGN_PCUIF_CNF" }, |
| { TBF_EV_DL_ACKNACK_MISS, "DL_ACKNACK_MISS" }, |
| { TBF_EV_LAST_DL_DATA_SENT, "LAST_DL_DATA_SENT" }, |
| { TBF_EV_LAST_UL_DATA_RECVD, "LAST_UL_DATA_RECVD" }, |
| { TBF_EV_FINAL_ACK_RECVD, "FINAL_ACK_RECVD" }, |
| { TBF_EV_FINAL_UL_ACK_CONFIRMED, "FINAL_UL_ACK_CONFIRMED" }, |
| { TBF_EV_MAX_N3101 , "MAX_N3101" }, |
| { TBF_EV_MAX_N3103 , "MAX_N3103" }, |
| { TBF_EV_MAX_N3105 , "MAX_N3105" }, |
| { 0, NULL } |
| }; |
| |
| static void mod_ass_type(struct tbf_fsm_ctx *ctx, uint8_t t, bool set) |
| { |
| const char *ch = "UNKNOWN"; |
| bool prev_set = ctx->state_flags & (1 << t); |
| |
| switch (t) { |
| case GPRS_RLCMAC_FLAG_CCCH: |
| ch = "CCCH"; |
| break; |
| case GPRS_RLCMAC_FLAG_PACCH: |
| ch = "PACCH"; |
| break; |
| default: |
| LOGPTBF(ctx->tbf, LOGL_ERROR, |
| "attempted to %sset unexpected ass. type %d - FIXME!\n", |
| set ? "" : "un", t); |
| return; |
| } |
| |
| if (set && prev_set) { |
| LOGPTBF(ctx->tbf, LOGL_ERROR, |
| "attempted to set ass. type %s which is already set.\n", ch); |
| } else if (!set && !prev_set) { |
| return; |
| } |
| |
| LOGPTBF(ctx->tbf, LOGL_INFO, "%sset ass. type %s [prev CCCH:%u, PACCH:%u]\n", |
| set ? "" : "un", ch, |
| !!(ctx->state_flags & (1 << GPRS_RLCMAC_FLAG_CCCH)), |
| !!(ctx->state_flags & (1 << GPRS_RLCMAC_FLAG_PACCH))); |
| |
| if (set) { |
| ctx->state_flags |= (1 << t); |
| } else { |
| ctx->state_flags &= GPRS_RLCMAC_FLAG_TO_MASK; /* keep to flags */ |
| ctx->state_flags &= ~(1 << t); |
| } |
| } |
| |
| |
| static void st_new(struct osmo_fsm_inst *fi, uint32_t event, void *data) |
| { |
| struct tbf_fsm_ctx *ctx = (struct tbf_fsm_ctx *)fi->priv; |
| switch (event) { |
| case TBF_EV_ASSIGN_ADD_CCCH: |
| mod_ass_type(ctx, GPRS_RLCMAC_FLAG_CCCH, true); |
| tbf_fsm_state_chg(fi, tbf_direction(ctx->tbf) == GPRS_RLCMAC_DL_TBF ? |
| TBF_ST_ASSIGN : TBF_ST_FLOW); |
| break; |
| case TBF_EV_ASSIGN_ADD_PACCH: |
| mod_ass_type(ctx, GPRS_RLCMAC_FLAG_PACCH, true); |
| tbf_fsm_state_chg(fi, TBF_ST_ASSIGN); |
| break; |
| default: |
| OSMO_ASSERT(0); |
| } |
| } |
| |
| static void st_assign_on_enter(struct osmo_fsm_inst *fi, uint32_t prev_state) |
| { |
| struct tbf_fsm_ctx *ctx = (struct tbf_fsm_ctx *)fi->priv; |
| unsigned long val; |
| unsigned int sec, micro; |
| |
| /* If assignment for this TBF is happening on PACCH, that means the |
| * actual Assignment procedure (tx/rx) is happening on another TBF (eg |
| * Ul TBF vs DL TBF). Hence we add a security timer here to free it in |
| * case the other TBF doesn't succeed in informing (assigning) the MS |
| * about this TBF, or simply because the scheduler takes too long to |
| * schedule it. This timer can probably be dropped once we make the |
| * other TBF always signal us assignment failure (we already get |
| * assignment success through TBF_EV_ASSIGN_ACK_PACCH) */ |
| if (ctx->state_flags & (1 << GPRS_RLCMAC_FLAG_PACCH)) { |
| fi->T = -2001; |
| val = osmo_tdef_get(the_pcu->T_defs, fi->T, OSMO_TDEF_MS, -1); |
| sec = val / 1000; |
| micro = (val % 1000) * 1000; |
| LOGPTBF(ctx->tbf, LOGL_DEBUG, |
| "Starting timer X2001 [assignment (PACCH)] with %u sec. %u microsec\n", |
| sec, micro); |
| osmo_timer_schedule(&fi->timer, sec, micro); |
| } else if (tbf_direction(ctx->tbf) == GPRS_RLCMAC_DL_TBF) { |
| /* GPRS_RLCMAC_FLAG_CCCH is set, so here we submitted an DL Ass through PCUIF on CCCH */ |
| } |
| } |
| |
| static void st_assign(struct osmo_fsm_inst *fi, uint32_t event, void *data) |
| { |
| struct tbf_fsm_ctx *ctx = (struct tbf_fsm_ctx *)fi->priv; |
| unsigned long val; |
| unsigned int sec, micro; |
| |
| switch (event) { |
| case TBF_EV_ASSIGN_ADD_CCCH: |
| mod_ass_type(ctx, GPRS_RLCMAC_FLAG_CCCH, true); |
| break; |
| case TBF_EV_ASSIGN_ADD_PACCH: |
| mod_ass_type(ctx, GPRS_RLCMAC_FLAG_PACCH, true); |
| break; |
| case TBF_EV_ASSIGN_ACK_PACCH: |
| tbf_assign_control_ts(ctx->tbf); |
| if (ctx->state_flags & (1 << GPRS_RLCMAC_FLAG_CCCH)) { |
| /* We now know that the PACCH really existed */ |
| LOGPTBF(ctx->tbf, LOGL_INFO, |
| "The TBF has been confirmed on the PACCH, " |
| "changed type from CCCH to PACCH\n"); |
| mod_ass_type(ctx, GPRS_RLCMAC_FLAG_CCCH, false); |
| mod_ass_type(ctx, GPRS_RLCMAC_FLAG_PACCH, true); |
| } |
| tbf_fsm_state_chg(fi, TBF_ST_FLOW); |
| break; |
| case TBF_EV_ASSIGN_PCUIF_CNF: |
| /* BTS informs us it sent Imm Ass for DL TBF over CCCH. We now |
| * have to wait for X2002 to trigger (meaning MS is already |
| * listening on PDCH) in order to move to FLOW state and start |
| * transmitting data to it. When X2002 triggers (see cb timer |
| * end of the file) it will send TBF_EV_ASSIGN_READY_CCCH back |
| * to us here. */ |
| OSMO_ASSERT(tbf_direction(ctx->tbf) == GPRS_RLCMAC_DL_TBF); |
| fi->T = -2002; |
| val = osmo_tdef_get(the_pcu->T_defs, fi->T, OSMO_TDEF_MS, -1); |
| sec = val / 1000; |
| micro = (val % 1000) * 1000; |
| LOGPTBF(ctx->tbf, LOGL_DEBUG, |
| "Starting timer X2002 [assignment (AGCH)] with %u sec. %u microsec\n", |
| sec, micro); |
| osmo_timer_schedule(&fi->timer, sec, micro); |
| break; |
| case TBF_EV_ASSIGN_READY_CCCH: |
| /* change state to FLOW, so scheduler will start transmission */ |
| tbf_fsm_state_chg(fi, TBF_ST_FLOW); |
| break; |
| case TBF_EV_MAX_N3105: |
| /* We are going to release, so abort any Pkt Ul Ass pending to be scheduled: */ |
| osmo_fsm_inst_dispatch(tbf_ul_ass_fi(ctx->tbf), TBF_UL_ASS_EV_ABORT, NULL); |
| ctx->T_release = 3195; |
| tbf_fsm_state_chg(fi, TBF_ST_RELEASING); |
| break; |
| default: |
| OSMO_ASSERT(0); |
| } |
| } |
| |
| static void st_flow(struct osmo_fsm_inst *fi, uint32_t event, void *data) |
| { |
| struct tbf_fsm_ctx *ctx = (struct tbf_fsm_ctx *)fi->priv; |
| |
| switch (event) { |
| case TBF_EV_DL_ACKNACK_MISS: |
| /* DL TBF: we missed a DL ACK/NACK. If we started assignment |
| * over CCCH and never received any DL ACK/NACK yet, it means we |
| * don't even know if the MS successfuly received the Imm Ass on |
| * CCCH and hence is listening on PDCH. Let's better refrain |
| * from continuing and start assignment on CCCH again */ |
| if ((ctx->state_flags & (1 << GPRS_RLCMAC_FLAG_CCCH)) |
| && !(ctx->state_flags & (1 << GPRS_RLCMAC_FLAG_DL_ACK))) { |
| struct GprsMs *ms = tbf_ms(ctx->tbf); |
| const char *imsi = ms_imsi(ms); |
| uint16_t pgroup; |
| LOGPTBF(ctx->tbf, LOGL_DEBUG, "Re-send downlink assignment on PCH (IMSI=%s)\n", |
| imsi); |
| tbf_fsm_state_chg(fi, TBF_ST_ASSIGN); |
| /* send immediate assignment */ |
| if ((pgroup = imsi2paging_group(imsi)) > 999) |
| LOGPTBF(ctx->tbf, LOGL_ERROR, "IMSI to paging group failed! (%s)\n", imsi); |
| bts_snd_dl_ass(ms->bts, ctx->tbf, pgroup); |
| } |
| break; |
| case TBF_EV_LAST_DL_DATA_SENT: |
| case TBF_EV_LAST_UL_DATA_RECVD: |
| /* All data has been sent or received, change state to FINISHED */ |
| tbf_fsm_state_chg(fi, TBF_ST_FINISHED); |
| break; |
| case TBF_EV_FINAL_ACK_RECVD: |
| /* We received Final Ack (DL ACK/NACK) from MS. move to |
| WAIT_RELEASE, we wait there for release or re-use the TBF in |
| case we receive more DL data to tx */ |
| tbf_fsm_state_chg(fi, TBF_ST_WAIT_RELEASE); |
| break; |
| case TBF_EV_MAX_N3101: |
| ctx->T_release = 3169; |
| tbf_fsm_state_chg(fi, TBF_ST_RELEASING); |
| break; |
| case TBF_EV_MAX_N3105: |
| ctx->T_release = 3195; |
| tbf_fsm_state_chg(fi, TBF_ST_RELEASING); |
| break; |
| default: |
| OSMO_ASSERT(0); |
| } |
| } |
| |
| static void st_finished(struct osmo_fsm_inst *fi, uint32_t event, void *data) |
| { |
| struct tbf_fsm_ctx *ctx = (struct tbf_fsm_ctx *)fi->priv; |
| switch (event) { |
| case TBF_EV_DL_ACKNACK_MISS: |
| break; |
| case TBF_EV_FINAL_ACK_RECVD: |
| /* We received Final Ack (DL ACK/NACK) from MS. move to |
| WAIT_RELEASE, we wait there for release or re-use the TBF in |
| case we receive more DL data to tx */ |
| tbf_fsm_state_chg(fi, TBF_ST_WAIT_RELEASE); |
| break; |
| case TBF_EV_FINAL_UL_ACK_CONFIRMED: |
| /* UL TBF ACKed our transmitted UL ACK/NACK with final Ack |
| * Indicator set to '1' t. We can free the TBF right away. */ |
| tbf_free(ctx->tbf); |
| break; |
| case TBF_EV_MAX_N3103: |
| ctx->T_release = 3169; |
| tbf_fsm_state_chg(fi, TBF_ST_RELEASING); |
| break; |
| case TBF_EV_MAX_N3105: |
| ctx->T_release = 3195; |
| tbf_fsm_state_chg(fi, TBF_ST_RELEASING); |
| break; |
| default: |
| OSMO_ASSERT(0); |
| } |
| } |
| |
| static void st_wait_release_on_enter(struct osmo_fsm_inst *fi, uint32_t prev_state) |
| { |
| struct tbf_fsm_ctx *ctx = (struct tbf_fsm_ctx *)fi->priv; |
| unsigned long val_s, val_ms, val_us; |
| OSMO_ASSERT(tbf_direction(ctx->tbf) == GPRS_RLCMAC_DL_TBF); |
| |
| fi->T = 3193; |
| val_ms = osmo_tdef_get(tbf_ms(ctx->tbf)->bts->T_defs_bts, fi->T, OSMO_TDEF_MS, -1); |
| val_s = val_ms / 1000; |
| val_us = (val_ms % 1000) * 1000; |
| LOGPTBF(ctx->tbf, LOGL_DEBUG, "starting timer T%u with %lu sec. %lu microsec\n", |
| fi->T, val_s, val_us); |
| osmo_timer_schedule(&fi->timer, val_s, val_us); |
| |
| mod_ass_type(ctx, GPRS_RLCMAC_FLAG_CCCH, false); |
| } |
| |
| static void st_wait_release(struct osmo_fsm_inst *fi, uint32_t event, void *data) |
| { |
| struct tbf_fsm_ctx *ctx = (struct tbf_fsm_ctx *)fi->priv; |
| switch (event) { |
| case TBF_EV_FINAL_ACK_RECVD: |
| /* ignore, duplicate ACK, we already know about since we are in WAIT_RELEASE */ |
| break; |
| case TBF_EV_MAX_N3101: |
| ctx->T_release = 3169; |
| tbf_fsm_state_chg(fi, TBF_ST_RELEASING); |
| break; |
| case TBF_EV_MAX_N3105: |
| ctx->T_release = 3195; |
| tbf_fsm_state_chg(fi, TBF_ST_RELEASING); |
| break; |
| default: |
| OSMO_ASSERT(0); |
| } |
| } |
| |
| static void st_releasing_on_enter(struct osmo_fsm_inst *fi, uint32_t prev_state) |
| { |
| struct tbf_fsm_ctx *ctx = (struct tbf_fsm_ctx *)fi->priv; |
| unsigned long val; |
| |
| if (!ctx->T_release) |
| return; |
| |
| /* In general we should end up here with an assigned timer in ctx->T_release. Possible values are: |
| * T3195: Wait for reuse of TFI(s) when there is no response from the MS |
| * (radio failure or cell change) for this TBF/MBMS radio bearer. |
| * T3169: Wait for reuse of USF and TFI(s) after the MS uplink assignment for this TBF is invalid. |
| */ |
| val = osmo_tdef_get(tbf_ms(ctx->tbf)->bts->T_defs_bts, ctx->T_release, OSMO_TDEF_S, -1); |
| fi->T = ctx->T_release; |
| LOGPTBF(ctx->tbf, LOGL_DEBUG, "starting timer T%u with %lu sec. %u microsec\n", |
| ctx->T_release, val, 0); |
| osmo_timer_schedule(&fi->timer, val, 0); |
| } |
| |
| static void st_releasing(struct osmo_fsm_inst *fi, uint32_t event, void *data) |
| { |
| switch (event) { |
| case TBF_EV_DL_ACKNACK_MISS: |
| /* Ignore, we don't care about missed DL ACK/NACK poll timeouts |
| * anymore, we are already releasing the TBF */ |
| break; |
| default: |
| OSMO_ASSERT(0); |
| } |
| } |
| |
| static void handle_timeout_X2002(struct tbf_fsm_ctx *ctx) |
| { |
| struct gprs_rlcmac_dl_tbf *dl_tbf = as_dl_tbf(ctx->tbf); |
| |
| /* X2002 is used only for DL TBF */ |
| OSMO_ASSERT(dl_tbf); |
| |
| if (ctx->fi->state == TBF_ST_ASSIGN) { |
| tbf_assign_control_ts(ctx->tbf); |
| |
| if (!tbf_can_upgrade_to_multislot(ctx->tbf)) { |
| /* change state to FLOW, so scheduler |
| * will start transmission */ |
| osmo_fsm_inst_dispatch(ctx->fi, TBF_EV_ASSIGN_READY_CCCH, NULL); |
| return; |
| } |
| |
| /* This tbf can be upgraded to use multiple DL |
| * timeslots and now that there is already one |
| * slot assigned send another DL assignment via |
| * PDCH. */ |
| |
| /* keep to flags */ |
| ctx->state_flags &= GPRS_RLCMAC_FLAG_TO_MASK; |
| |
| tbf_update(ctx->tbf); |
| |
| tbf_dl_trigger_ass(dl_tbf, ctx->tbf); |
| } else |
| LOGPTBF(ctx->tbf, LOGL_NOTICE, "Continue flow after IMM.ASS confirm\n"); |
| } |
| |
| static int tbf_fsm_timer_cb(struct osmo_fsm_inst *fi) |
| { |
| struct tbf_fsm_ctx *ctx = (struct tbf_fsm_ctx *)fi->priv; |
| switch (fi->T) { |
| case -2002: |
| handle_timeout_X2002(ctx); |
| break; |
| case -2001: |
| LOGPTBF(ctx->tbf, LOGL_NOTICE, "releasing due to PACCH assignment timeout.\n"); |
| /* fall-through */ |
| case 3169: |
| case 3193: |
| case 3195: |
| tbf_free(ctx->tbf); |
| break; |
| default: |
| OSMO_ASSERT(0); |
| } |
| return 0; |
| } |
| |
| static struct osmo_fsm_state tbf_fsm_states[] = { |
| [TBF_ST_NEW] = { |
| .in_event_mask = |
| X(TBF_EV_ASSIGN_ADD_CCCH) | |
| X(TBF_EV_ASSIGN_ADD_PACCH), |
| .out_state_mask = |
| X(TBF_ST_ASSIGN) | |
| X(TBF_ST_FLOW) | |
| X(TBF_ST_RELEASING), |
| .name = "NEW", |
| .action = st_new, |
| }, |
| [TBF_ST_ASSIGN] = { |
| .in_event_mask = |
| X(TBF_EV_ASSIGN_ADD_CCCH) | |
| X(TBF_EV_ASSIGN_ADD_PACCH) | |
| X(TBF_EV_ASSIGN_ACK_PACCH) | |
| X(TBF_EV_ASSIGN_PCUIF_CNF) | |
| X(TBF_EV_ASSIGN_READY_CCCH) | |
| X(TBF_EV_MAX_N3105), |
| .out_state_mask = |
| X(TBF_ST_FLOW) | |
| X(TBF_ST_FINISHED) | |
| X(TBF_ST_RELEASING), |
| .name = "ASSIGN", |
| .action = st_assign, |
| .onenter = st_assign_on_enter, |
| }, |
| [TBF_ST_FLOW] = { |
| .in_event_mask = |
| X(TBF_EV_DL_ACKNACK_MISS) | |
| X(TBF_EV_LAST_DL_DATA_SENT) | |
| X(TBF_EV_LAST_UL_DATA_RECVD) | |
| X(TBF_EV_FINAL_ACK_RECVD) | |
| X(TBF_EV_MAX_N3101) | |
| X(TBF_EV_MAX_N3105), |
| .out_state_mask = |
| X(TBF_ST_ASSIGN) | |
| X(TBF_ST_FINISHED) | |
| X(TBF_ST_WAIT_RELEASE) | |
| X(TBF_ST_RELEASING), |
| .name = "FLOW", |
| .action = st_flow, |
| }, |
| [TBF_ST_FINISHED] = { |
| .in_event_mask = |
| X(TBF_EV_DL_ACKNACK_MISS) | |
| X(TBF_EV_FINAL_ACK_RECVD) | |
| X(TBF_EV_FINAL_UL_ACK_CONFIRMED) | |
| X(TBF_EV_MAX_N3103) | |
| X(TBF_EV_MAX_N3105), |
| .out_state_mask = |
| X(TBF_ST_WAIT_RELEASE) | |
| X(TBF_ST_RELEASING), |
| .name = "FINISHED", |
| .action = st_finished, |
| }, |
| [TBF_ST_WAIT_RELEASE] = { |
| .in_event_mask = |
| X(TBF_EV_FINAL_ACK_RECVD) | |
| X(TBF_EV_MAX_N3101) | |
| X(TBF_EV_MAX_N3105), |
| .out_state_mask = |
| X(TBF_ST_RELEASING), |
| .name = "WAIT_RELEASE", |
| .action = st_wait_release, |
| .onenter = st_wait_release_on_enter, |
| }, |
| [TBF_ST_RELEASING] = { |
| .in_event_mask = |
| X(TBF_EV_DL_ACKNACK_MISS), |
| .out_state_mask = |
| 0, |
| .name = "RELEASING", |
| .action = st_releasing, |
| .onenter = st_releasing_on_enter, |
| }, |
| }; |
| |
| struct osmo_fsm tbf_fsm = { |
| .name = "TBF", |
| .states = tbf_fsm_states, |
| .num_states = ARRAY_SIZE(tbf_fsm_states), |
| .timer_cb = tbf_fsm_timer_cb, |
| .log_subsys = DTBF, |
| .event_names = tbf_fsm_event_names, |
| }; |
| |
| static __attribute__((constructor)) void tbf_fsm_init(void) |
| { |
| OSMO_ASSERT(osmo_fsm_register(&tbf_fsm) == 0); |
| } |