WIP: Initial check-in of a new virtual BTS

1 files changed, 594 insertions, 0 deletions

diff --git a/src/osmo-bts-virtual/scheduler_virtbts.c b/src/osmo-bts-virtual/scheduler_virtbts.c
new file mode 100644
index 00000000..c23632c5
--- /dev/null
+++ b/src/osmo-bts-virtual/scheduler_virtbts.c
@@ -0,0 +1,594 @@
+/* Scheduler worker functiosn for Virtua OsmoBTS */
+
+/* (C) 2015 by Harald Welte <laforge@gnumonks.org>
+ *
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation; either version 3 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 Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <stdint.h>
+#include <ctype.h>
+
+#include <osmocom/core/msgb.h>
+#include <osmocom/core/talloc.h>
+#include <osmocom/core/bits.h>
+#include <osmocom/core/gsmtap_util.h>
+
+#include <osmocom/netif/rtp.h>
+
+#include <osmo-bts/gsm_data.h>
+#include <osmo-bts/phy_link.h>
+#include <osmo-bts/logging.h>
+#include <osmo-bts/rsl.h>
+#include <osmo-bts/l1sap.h>
+#include <osmo-bts/amr.h>
+#include <osmo-bts/scheduler.h>
+#include <osmo-bts/scheduler_backend.h>
+
+#include "virtual_um.h"
+
+extern void *tall_bts_ctx;
+
+
+
+static void tx_to_virt_um(struct l1sched_trx *l1t, uint8_t tn, uint32_t fn,
+			  enum trx_chan_type chan, struct msgb *msg)
+{
+	const struct trx_chan_desc *chdesc = &trx_chan_desc[chan];
+	uint8_t ss = 0; //FIXME(chdesc);
+	uint8_t gsmtap_chan;
+	struct msgb *outmsg;
+
+	gsmtap_chan = chantype_rsl2gsmtap(chdesc->chan_nr, chdesc->link_id);
+	outmsg = gsmtap_makemsg(l1t->trx->arfcn, tn, gsmtap_chan, ss, fn,
+				0, 0, msgb_l2(msg), msgb_l2len(msg));
+	if (outmsg) {
+		struct phy_instance *pinst = trx_phy_instance(l1t->trx);
+		struct virt_um_inst *virt_um = pinst->phy_link->u.virt.virt_um;
+		virt_um_write_msg(virt_um, outmsg);
+	}
+
+	/* free message */
+	msgb_free(msg);
+}
+
+/*
+ * TX on downlink
+ */
+
+/* an IDLE burst returns nothing. on C0 it is replaced by dummy burst */
+ubit_t *tx_idle_fn(struct l1sched_trx *l1t, uint8_t tn, uint32_t fn,
+	enum trx_chan_type chan, uint8_t bid)
+{
+	return NULL;
+}
+
+ubit_t *tx_fcch_fn(struct l1sched_trx *l1t, uint8_t tn, uint32_t fn,
+	enum trx_chan_type chan, uint8_t bid)
+{
+	return NULL;
+}
+
+ubit_t *tx_sch_fn(struct l1sched_trx *l1t, uint8_t tn, uint32_t fn,
+	enum trx_chan_type chan, uint8_t bid)
+{
+	return NULL;
+}
+
+ubit_t *tx_data_fn(struct l1sched_trx *l1t, uint8_t tn, uint32_t fn,
+	enum trx_chan_type chan, uint8_t bid)
+{
+	struct l1sched_ts *l1ts = l1sched_trx_get_ts(l1t, tn);
+	struct gsm_bts_trx_ts *ts = &l1t->trx->ts[tn];
+	struct msgb *msg;
+
+	if (bid > 0)
+		return NULL;
+
+	/* get mac block from queue */
+	msg = _sched_dequeue_prim(l1t, tn, fn, chan);
+	if (msg)
+		goto got_msg;
+
+	LOGP(DL1P, LOGL_INFO, "%s has not been served !! No prim for "
+		"trx=%u ts=%u at fn=%u to transmit.\n", 
+		trx_chan_desc[chan].name, l1t->trx->nr, tn, fn);
+
+no_msg:
+	return NULL;
+
+got_msg:
+	/* check validity of message */
+	if (msgb_l2len(msg) != GSM_MACBLOCK_LEN) {
+		LOGP(DL1P, LOGL_FATAL, "Prim not 23 bytes, please FIX! "
+			"(len=%d)\n", msgb_l2len(msg));
+		/* free message */
+		msgb_free(msg);
+		goto no_msg;
+	}
+
+	tx_to_virt_um(l1t, tn, fn, chan, msg);
+
+	return NULL;
+}
+
+ubit_t *tx_pdtch_fn(struct l1sched_trx *l1t, uint8_t tn, uint32_t fn,
+	enum trx_chan_type chan, uint8_t bid)
+{
+	struct l1sched_ts *l1ts = l1sched_trx_get_ts(l1t, tn);
+	struct gsm_bts_trx_ts *ts = &l1t->trx->ts[tn];
+	struct msgb *msg = NULL; /* make GCC happy */
+	int rc;
+
+	if (bid > 0)
+		return NULL;
+
+	/* get mac block from queue */
+	msg = _sched_dequeue_prim(l1t, tn, fn, chan);
+	if (msg)
+		goto got_msg;
+
+	LOGP(DL1P, LOGL_INFO, "%s has not been served !! No prim for "
+		"trx=%u ts=%u at fn=%u to transmit.\n", 
+		trx_chan_desc[chan].name, l1t->trx->nr, tn, fn);
+
+no_msg:
+	return NULL;
+
+got_msg:
+	tx_to_virt_um(l1t, tn, fn, chan, msg);
+
+	return NULL;
+}
+
+static void tx_tch_common(struct l1sched_trx *l1t, uint8_t tn, uint32_t fn,
+	enum trx_chan_type chan, uint8_t bid, struct msgb **_msg_tch,
+	struct msgb **_msg_facch, int codec_mode_request)
+{
+	struct l1sched_ts *l1ts = l1sched_trx_get_ts(l1t, tn);
+	struct msgb *msg1, *msg2, *msg_tch = NULL, *msg_facch = NULL;
+	struct l1sched_chan_state *chan_state = &l1ts->chan_state[chan];
+	uint8_t rsl_cmode = chan_state->rsl_cmode;
+	uint8_t tch_mode = chan_state->tch_mode;
+	struct osmo_phsap_prim *l1sap;
+#if 0
+	/* handle loss detection of received TCH frames */
+	if (rsl_cmode == RSL_CMOD_SPD_SPEECH
+	 && ++(chan_state->lost) > 5) {
+		uint8_t tch_data[GSM_FR_BYTES];
+		int len;
+
+		LOGP(DL1P, LOGL_NOTICE, "Missing TCH bursts detected, sending "
+			"BFI for %s\n", trx_chan_desc[chan].name);
+
+		/* indicate bad frame */
+		switch (tch_mode) {
+		case GSM48_CMODE_SPEECH_V1: /* FR / HR */
+			if (chan != TRXC_TCHF) { /* HR */
+				tch_data[0] = 0x70; /* F = 0, FT = 111 */
+				memset(tch_data + 1, 0, 14);
+				len = 15;
+				break;
+			}
+			memset(tch_data, 0, GSM_FR_BYTES);
+			len = GSM_FR_BYTES;
+			break;
+		case GSM48_CMODE_SPEECH_EFR: /* EFR */
+			if (chan != TRXC_TCHF)
+				goto inval_mode1;
+			memset(tch_data, 0, GSM_EFR_BYTES);
+			len = GSM_EFR_BYTES;
+			break;
+		case GSM48_CMODE_SPEECH_AMR: /* AMR */
+			len = amr_compose_payload(tch_data,
+				chan_state->codec[chan_state->dl_cmr],
+				chan_state->codec[chan_state->dl_ft], 1);
+			if (len < 2)
+				break;
+			memset(tch_data + 2, 0, len - 2);
+			_sched_compose_tch_ind(l1t, tn, 0, chan, tch_data, len);
+			break;
+		default:
+inval_mode1:
+			LOGP(DL1P, LOGL_ERROR, "TCH mode invalid, please "
+				"fix!\n");
+			len = 0;
+		}
+		if (len)
+			_sched_compose_tch_ind(l1t, tn, 0, chan, tch_data, len);
+	}
+#endif
+
+	/* get frame and unlink from queue */
+	msg1 = _sched_dequeue_prim(l1t, tn, fn, chan);
+	msg2 = _sched_dequeue_prim(l1t, tn, fn, chan);
+	if (msg1) {
+		l1sap = msgb_l1sap_prim(msg1);
+		if (l1sap->oph.primitive == PRIM_TCH) {
+			msg_tch = msg1;
+			if (msg2) {
+				l1sap = msgb_l1sap_prim(msg2);
+				if (l1sap->oph.primitive == PRIM_TCH) {
+					LOGP(DL1P, LOGL_FATAL, "TCH twice, "
+						"please FIX! ");
+					msgb_free(msg2);
+				} else
+					msg_facch = msg2;
+			}
+		} else {
+			msg_facch = msg1;
+			if (msg2) {
+				l1sap = msgb_l1sap_prim(msg2);
+				if (l1sap->oph.primitive != PRIM_TCH) {
+					LOGP(DL1P, LOGL_FATAL, "FACCH twice, "
+						"please FIX! ");
+					msgb_free(msg2);
+				} else
+					msg_tch = msg2;
+			}
+		}
+	} else if (msg2) {
+		l1sap = msgb_l1sap_prim(msg2);
+		if (l1sap->oph.primitive == PRIM_TCH)
+			msg_tch = msg2;
+		else
+			msg_facch = msg2;
+	}
+
+	/* check validity of message */
+	if (msg_facch && msgb_l2len(msg_facch) != GSM_MACBLOCK_LEN) {
+		LOGP(DL1P, LOGL_FATAL, "Prim not 23 bytes, please FIX! "
+			"(len=%d)\n", msgb_l2len(msg_facch));
+		/* free message */
+		msgb_free(msg_facch);
+		msg_facch = NULL;
+	}
+
+	/* check validity of message, get AMR ft and cmr */
+	if (!msg_facch && msg_tch) {
+		int len;
+		uint8_t bfi, cmr_codec, ft_codec;
+		int cmr, ft, i;
+
+		if (rsl_cmode != RSL_CMOD_SPD_SPEECH) {
+			LOGP(DL1P, LOGL_NOTICE, "%s Dropping speech frame, "
+				"because we are not in speech mode trx=%u "
+				"ts=%u at fn=%u.\n", trx_chan_desc[chan].name,
+				l1t->trx->nr, tn, fn);
+			goto free_bad_msg;
+		}
+
+		switch (tch_mode) {
+		case GSM48_CMODE_SPEECH_V1: /* FR / HR */
+			if (chan != TRXC_TCHF) { /* HR */
+				len = 15;
+				if (msgb_l2len(msg_tch) >= 1
+				 && (msg_tch->l2h[0] & 0xf0) != 0x00) {
+					LOGP(DL1P, LOGL_NOTICE, "%s "
+						"Transmitting 'bad "
+						"HR frame' trx=%u ts=%u at "
+						"fn=%u.\n",
+						trx_chan_desc[chan].name,
+						l1t->trx->nr, tn, fn);
+					goto free_bad_msg;
+				}
+				break;
+			}
+			len = GSM_FR_BYTES;
+			if (msgb_l2len(msg_tch) >= 1
+			 && (msg_tch->l2h[0] >> 4) != 0xd) {
+				LOGP(DL1P, LOGL_NOTICE, "%s Transmitting 'bad "
+					"FR frame' trx=%u ts=%u at fn=%u.\n",
+					trx_chan_desc[chan].name,
+					l1t->trx->nr, tn, fn);
+				goto free_bad_msg;
+			}
+			break;
+		case GSM48_CMODE_SPEECH_EFR: /* EFR */
+			if (chan != TRXC_TCHF)
+				goto inval_mode2;
+			len = GSM_EFR_BYTES;
+			if (msgb_l2len(msg_tch) >= 1
+			 && (msg_tch->l2h[0] >> 4) != 0xc) {
+				LOGP(DL1P, LOGL_NOTICE, "%s Transmitting 'bad "
+					"EFR frame' trx=%u ts=%u at fn=%u.\n",
+					trx_chan_desc[chan].name,
+					l1t->trx->nr, tn, fn);
+				goto free_bad_msg;
+			}
+			break;
+		case GSM48_CMODE_SPEECH_AMR: /* AMR */
+#if 0
+			len = amr_decompose_payload(msg_tch->l2h,
+				msgb_l2len(msg_tch), &cmr_codec, &ft_codec,
+				&bfi);
+			cmr = -1;
+			ft = -1;
+			for (i = 0; i < chan_state->codecs; i++) {
+				if (chan_state->codec[i] == cmr_codec)
+					cmr = i;
+				if (chan_state->codec[i] == ft_codec)
+					ft = i;
+			}
+			if (cmr >= 0) { /* new request */
+				chan_state->dl_cmr = cmr;
+				/* disable AMR loop */
+				trx_loop_amr_set(chan_state, 0);
+			} else {
+				/* enable AMR loop */
+				trx_loop_amr_set(chan_state, 1);
+			}
+			if (ft < 0) {
+				LOGP(DL1P, LOGL_ERROR, "%s Codec (FT = %d) "
+					" of RTP frame not in list. "
+					"trx=%u ts=%u\n",
+					trx_chan_desc[chan].name, ft_codec,
+					l1t->trx->nr, tn);
+				goto free_bad_msg;
+			}
+			if (codec_mode_request && chan_state->dl_ft != ft) {
+				LOGP(DL1P, LOGL_NOTICE, "%s Codec (FT = %d) "
+					" of RTP cannot be changed now, but in "
+					"next frame. trx=%u ts=%u\n",
+					trx_chan_desc[chan].name, ft_codec,
+					l1t->trx->nr, tn);
+				goto free_bad_msg;
+			}
+			chan_state->dl_ft = ft;
+			if (bfi) {
+				LOGP(DL1P, LOGL_NOTICE, "%s Transmitting 'bad "
+					"AMR frame' trx=%u ts=%u at fn=%u.\n",
+					trx_chan_desc[chan].name,
+					l1t->trx->nr, tn, fn);
+				goto free_bad_msg;
+			}
+#endif
+			break;
+		default:
+inval_mode2:
+			LOGP(DL1P, LOGL_ERROR, "TCH mode invalid, please "
+				"fix!\n");
+			goto free_bad_msg;
+		}
+		if (len < 0) {
+			LOGP(DL1P, LOGL_ERROR, "Cannot send invalid AMR "
+				"payload\n");
+			goto free_bad_msg;
+		}
+		if (msgb_l2len(msg_tch) != len) {
+			LOGP(DL1P, LOGL_ERROR, "Cannot send payload with "
+				"invalid length! (expecing %d, received %d)\n",
+				len, msgb_l2len(msg_tch));
+free_bad_msg:
+			/* free message */
+			msgb_free(msg_tch);
+			msg_tch = NULL;
+			goto send_frame;
+		}
+	}
+
+send_frame:
+	*_msg_tch = msg_tch;
+	*_msg_facch = msg_facch;
+}
+
+ubit_t *tx_tchf_fn(struct l1sched_trx *l1t, uint8_t tn, uint32_t fn,
+	enum trx_chan_type chan, uint8_t bid)
+{
+	struct msgb *msg_tch = NULL, *msg_facch = NULL;
+	struct l1sched_ts *l1ts = l1sched_trx_get_ts(l1t, tn);
+	struct gsm_bts_trx_ts *ts = &l1t->trx->ts[tn];
+	struct l1sched_chan_state *chan_state = &l1ts->chan_state[chan];
+	uint8_t tch_mode = chan_state->tch_mode;
+
+	if (bid > 0)
+		return NULL;
+
+	tx_tch_common(l1t, tn, fn, chan, bid, &msg_tch, &msg_facch,
+		(((fn + 4) % 26) >> 2) & 1);
+
+	/* no message at all */
+	if (!msg_tch && !msg_facch) {
+		LOGP(DL1P, LOGL_INFO, "%s has not been served !! No prim for "
+			"trx=%u ts=%u at fn=%u to transmit.\n", 
+			trx_chan_desc[chan].name, l1t->trx->nr, tn, fn);
+		goto send_burst;
+	}
+
+	if (msg_facch) {
+		tx_to_virt_um(l1t, tn, fn, chan, msg_facch);
+		msgb_free(msg_tch);
+	} else
+		tx_to_virt_um(l1t, tn, fn, chan, msg_tch);
+
+send_burst:
+
+	return NULL;
+}
+
+ubit_t *tx_tchh_fn(struct l1sched_trx *l1t, uint8_t tn, uint32_t fn,
+	enum trx_chan_type chan, uint8_t bid)
+{
+	struct msgb *msg_tch = NULL, *msg_facch = NULL;
+	struct l1sched_ts *l1ts = l1sched_trx_get_ts(l1t, tn);
+	struct gsm_bts_trx_ts *ts = &l1t->trx->ts[tn];
+	struct l1sched_chan_state *chan_state = &l1ts->chan_state[chan];
+	uint8_t tch_mode = chan_state->tch_mode;
+
+	/* send burst, if we already got a frame */
+	if (bid > 0)
+		return NULL;
+
+	/* get TCH and/or FACCH */
+	tx_tch_common(l1t, tn, fn, chan, bid, &msg_tch, &msg_facch,
+		(((fn + 4) % 26) >> 2) & 1);
+
+	/* check for FACCH alignment */
+	if (msg_facch && ((((fn + 4) % 26) >> 2) & 1)) {
+		LOGP(DL1P, LOGL_ERROR, "%s Cannot transmit FACCH starting on "
+			"even frames, please fix RTS!\n",
+			trx_chan_desc[chan].name);
+		msgb_free(msg_facch);
+		msg_facch = NULL;
+	}
+
+	/* no message at all */
+	if (!msg_tch && !msg_facch && !chan_state->dl_ongoing_facch) {
+		LOGP(DL1P, LOGL_INFO, "%s has not been served !! No prim for "
+			"trx=%u ts=%u at fn=%u to transmit.\n", 
+			trx_chan_desc[chan].name, l1t->trx->nr, tn, fn);
+		goto send_burst;
+	}
+
+	if (msg_facch) {
+		tx_to_virt_um(l1t, tn, fn, chan, msg_facch);
+		msgb_free(msg_tch);
+	} else
+		tx_to_virt_um(l1t, tn, fn, chan, msg_tch);
+
+send_burst:
+	return NULL;
+}
+
+
+/***********************************************************************
+ * RX on uplink (indication to upper layer)
+ ***********************************************************************/
+
+/* we don't use those functions, as we feed the MAC frames from GSMTAP
+ * directly into the L1SAP, bypassing the TDMA multiplex logic oriented
+ * towards receiving bursts */
+
+int rx_rach_fn(struct l1sched_trx *l1t, uint8_t tn, uint32_t fn,
+	enum trx_chan_type chan, uint8_t bid, sbit_t *bits, int8_t rssi,
+	float toa)
+{
+	return 0;
+}
+
+/*! \brief a single burst was received by the PHY, process it */
+int rx_data_fn(struct l1sched_trx *l1t, uint8_t tn, uint32_t fn,
+	enum trx_chan_type chan, uint8_t bid, sbit_t *bits, int8_t rssi,
+	float toa)
+{
+	return 0;
+}
+
+int rx_pdtch_fn(struct l1sched_trx *l1t, uint8_t tn, uint32_t fn,
+	enum trx_chan_type chan, uint8_t bid, sbit_t *bits, int8_t rssi,
+	float toa)
+{
+	return 0;
+}
+
+int rx_tchf_fn(struct l1sched_trx *l1t, uint8_t tn, uint32_t fn,
+	enum trx_chan_type chan, uint8_t bid, sbit_t *bits, int8_t rssi,
+	float toa)
+{
+	return 0;
+}
+
+int rx_tchh_fn(struct l1sched_trx *l1t, uint8_t tn, uint32_t fn,
+	enum trx_chan_type chan, uint8_t bid, sbit_t *bits, int8_t rssi,
+	float toa)
+{
+	return 0;
+}
+
+void _sched_act_rach_det(struct l1sched_trx *l1t, uint8_t tn, uint8_t ss, int activate)
+{
+}
+
+/***********************************************************************
+ * main scheduler function
+ ***********************************************************************/
+
+#define RTS_ADVANCE		5	/* about 20ms */
+#define FRAME_DURATION_uS	4615
+
+static int vbts_sched_fn(struct gsm_bts *bts, uint32_t fn)
+{
+	struct gsm_bts_trx *trx;
+
+	/* send time indication */
+	l1if_mph_time_ind(bts, fn);
+
+	/* advance the frame number? */
+
+	llist_for_each_entry(trx, &bts->trx_list, list) {
+		struct phy_instance *pinst = trx_phy_instance(trx);
+		struct l1sched_trx *l1t = &pinst->u.virt.sched;
+		int tn;
+
+		for (tn = 0; tn < ARRAY_SIZE(l1t->ts); tn++) {
+			/* Generate RTS.ind to higher layers */
+			_sched_rts(l1t, tn, (fn + RTS_ADVANCE) % GSM_HYPERFRAME);
+			/* schedule transmit backend functions */
+			_sched_dl_burst(l1t, tn, fn);
+		}
+	}
+
+	return 0;
+}
+
+static void vbts_fn_timer_cb(void *data)
+{
+	struct gsm_bts *bts = data;
+	struct gsm_bts_role_bts *btsb = bts_role_bts(bts);
+	struct timeval tv_now;
+	struct timeval *tv_clock = &btsb->vbts.tv_clock;
+	int32_t elapsed_us;
+
+	gettimeofday(&tv_now, NULL);
+
+	elapsed_us = (tv_now.tv_sec - tv_clock->tv_sec) * 1000000 +
+		     (tv_now.tv_usec - tv_clock->tv_usec);
+
+	if (elapsed_us > 2*FRAME_DURATION_uS)
+		LOGP(DL1P, LOGL_NOTICE, "vbts_fn_timer_cb after %d us\n", elapsed_us);
+
+	while (elapsed_us > FRAME_DURATION_uS / 2) {
+		const struct timeval tv_frame = {
+			.tv_sec = 0,
+			.tv_usec = FRAME_DURATION_uS,
+		};
+		timeradd(tv_clock, &tv_frame, tv_clock);
+		btsb->vbts.last_fn = (btsb->vbts.last_fn + 1) % GSM_HYPERFRAME;
+		vbts_sched_fn(bts, btsb->vbts.last_fn);
+		elapsed_us -= FRAME_DURATION_uS;
+	}
+
+	/* re-schedule the timer */
+	osmo_timer_schedule(&btsb->vbts.fn_timer, 0, FRAME_DURATION_uS - elapsed_us);
+}
+
+int vbts_sched_start(struct gsm_bts *bts)
+{
+	struct gsm_bts_role_bts *btsb = bts_role_bts(bts);
+
+	LOGP(DL1P, LOGL_NOTICE, "starting VBTS scheduler\n");
+
+	memset(&btsb->vbts.fn_timer, 0, sizeof(btsb->vbts.fn_timer));
+	btsb->vbts.fn_timer.cb = vbts_fn_timer_cb;
+	btsb->vbts.fn_timer.data = bts;
+
+	gettimeofday(&btsb->vbts.tv_clock, NULL);
+	osmo_timer_schedule(&btsb->vbts.fn_timer, 0, FRAME_DURATION_uS);
+
+	return 0;
+}