replace dl_ass_state with osmocom FSM
Related: OS#2709
Change-Id: Ia33418478e17986a316ffda48b091030f53fa371
diff --git a/src/tbf_dl_ass_fsm.c b/src/tbf_dl_ass_fsm.c
new file mode 100644
index 0000000..8085fbd
--- /dev/null
+++ b/src/tbf_dl_ass_fsm.c
@@ -0,0 +1,273 @@
+/* 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.
+ *
+ * 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/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_ul.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->ts));
+
+ if (tbf_ul_ass_fi(ctx->tbf)->state == TBF_UL_ASS_WAIT_ACK)
+ {
+ LOGPTBF(ctx->tbf, LOGL_DEBUG,
+ "Polling is already scheduled, so we must wait for the uplink assignment...\n");
+ // FIXME: call tbf_dl_ass_fsm_state_chg(ctx->fi, TBF_DL_ASS_NONE); ?
+ return NULL;
+ }
+ rc = tbf_check_polling(ctx->tbf, d->fn, d->ts, &new_poll_fn, &rrbp);
+ if (rc < 0)
+ return NULL;
+
+ /* on uplink TBF we get the downlink TBF to be assigned. */
+ if (tbf_direction(ctx->tbf) == GPRS_RLCMAC_UL_TBF) {
+ struct gprs_rlcmac_ul_tbf *ul_tbf = as_ul_tbf(ctx->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(ctx->tbf, LOGL_DEBUG,
+ "Cannot assign DL TBF now, because contention resolution is not finished.\n");
+ // FIXME: call tbf_dl_ass_fsm_state_chg(ctx->fi, TBF_DL_ASS_NONE); ?
+ 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 (new_dl_tbf == as_dl_tbf(ctx->tbf))
+ LOGPTBF(ctx->tbf, LOGL_DEBUG, "New and old TBF are the same.\n");
+
+ 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);
+
+ LOGPTBF((struct gprs_rlcmac_tbf *)new_dl_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->ts, PDCH_ULC_POLL_DL_ASS);
+
+ 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)
+{
+ 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:
+ /* 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)
+{
+ struct tbf_dl_ass_fsm_ctx *ctx = (struct tbf_dl_ass_fsm_ctx *)fi->priv;
+ switch (fi->T) {
+ case -2000:
+ tbf_free(ctx->tbf);
+ break;
+ 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),
+ .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, uint32_t fn, uint8_t ts)
+{
+ int rc;
+ struct tbf_dl_ass_ev_create_rlcmac_msg_ctx data_ctx = {
+ .fn = fn,
+ .ts = ts,
+ .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)
+{
+ struct osmo_fsm_inst *fi = tbf_dl_ass_fi(tbf);
+ return fi->state == TBF_DL_ASS_SEND_ASS;
+}