diff options
Diffstat (limited to 'src/tbf_fsm.c')
| -rw-r--r-- | src/tbf_fsm.c | 466 |
1 files changed, 6 insertions, 460 deletions
diff --git a/src/tbf_fsm.c b/src/tbf_fsm.c index af2b34ef..f6dafc3c 100644 --- a/src/tbf_fsm.c +++ b/src/tbf_fsm.c @@ -1,6 +1,6 @@ /* tbf_fsm.c * - * Copyright (C) 2021 by sysmocom - s.f.m.c. GmbH <info@sysmocom.de> + * Copyright (C) 2021-2022 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 @@ -12,33 +12,14 @@ * 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 <osmocom/core/utils.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] = {}, -}; +/* Note: This file contains shared code for UL/DL TBF FSM. See tbf_dl_fsm.c and + * tbf_ul_fsm.c for the actual implementations of the FSM */ const struct value_string tbf_fsm_event_names[] = { { TBF_EV_ASSIGN_ADD_CCCH, "ASSIGN_ADD_CCCH" }, @@ -46,6 +27,8 @@ const struct value_string tbf_fsm_event_names[] = { { 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_FIRST_UL_DATA_RECVD, "FIRST_UL_DATA_RECVD" }, + { TBF_EV_CONTENTION_RESOLUTION_MS_SUCCESS, "CONTENTION_RESOLUTION_MS_SUCCESS" }, { 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" }, @@ -56,440 +39,3 @@ const struct value_string tbf_fsm_event_names[] = { { 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); -} |