PCU: Add PCU socket interface to BTS.

A special command line option "-P" is used to enable socket interface
and signal available GPRS MO object to BSC.

6 files changed, 956 insertions, 16 deletions

diff --git a/src/common/Makefile.am b/src/common/Makefile.am
index 042a3dc6..209c01af 100644
--- a/src/common/Makefile.am
+++ b/src/common/Makefile.am
@@ -5,4 +5,4 @@ LDADD = $(LIBOSMOCORE_LIBS) $(LIBOSMOTRAU_LIBS)
 noinst_LIBRARIES = libbts.a
 libbts_a_SOURCES = gsm_data_shared.c sysinfo.c logging.c abis.c oml.c bts.c \
 		   rsl.c vty.c paging.c measurement.c amr.c lchan.c \
-		   load_indication.c
+		   load_indication.c pcu_sock.c
diff --git a/src/common/bts.c b/src/common/bts.c
index 208e1c60..4be901bb 100644
--- a/src/common/bts.c
+++ b/src/common/bts.c
@@ -50,6 +50,7 @@ struct gsm_network bts_gsmnet = {
 };
 
 void *tall_bts_ctx;
+extern int gprs_enabled;
 
 int bts_init(struct gsm_bts *bts)
 {
@@ -145,10 +146,12 @@ int bts_link_estab(struct gsm_bts *bts)
 	oml_tx_state_changed(&bts->mo);
 
 	/* those should all be in DEPENDENCY */
-	oml_tx_state_changed(&bts->gprs.nse.mo);
-	oml_tx_state_changed(&bts->gprs.cell.mo);
-	oml_tx_state_changed(&bts->gprs.nsvc[0].mo);
-	oml_tx_state_changed(&bts->gprs.nsvc[1].mo);
+	if (gprs_enabled) {
+		oml_tx_state_changed(&bts->gprs.nse.mo);
+		oml_tx_state_changed(&bts->gprs.cell.mo);
+		oml_tx_state_changed(&bts->gprs.nsvc[0].mo);
+		oml_tx_state_changed(&bts->gprs.nsvc[1].mo);
+	}
 
 	/* All other objects start off-line until the BTS Model code says otherwise */
 	for (i = 0; i < bts->num_trx; i++) {
diff --git a/src/common/measurement.c b/src/common/measurement.c
index 62e4b893..e2b9ff9e 100644
--- a/src/common/measurement.c
+++ b/src/common/measurement.c
@@ -216,6 +216,7 @@ int ts_meas_check_compute(struct gsm_bts_trx_ts *ts, uint32_t fn)
 		case GSM_LCHAN_SDCCH:
 		case GSM_LCHAN_TCH_F:
 		case GSM_LCHAN_TCH_H:
+		case GSM_LCHAN_PDTCH:
 			lchan_meas_check_compute(lchan, fn);
 			break;
 		default:
diff --git a/src/common/pcu_sock.c b/src/common/pcu_sock.c
new file mode 100644
index 00000000..f737e60c
--- /dev/null
+++ b/src/common/pcu_sock.c
@@ -0,0 +1,851 @@
+/* pcu_sock.c: Connect from PCU via unix domain socket */
+
+/* (C) 2008-2010 by Harald Welte <laforge@gnumonks.org>
+ * (C) 2009-2012 by Andreas Eversberg <jolly@eversberg.eu>
+ * (C) 2012 by Holger Hans Peter Freyther
+ * All Rights Reserved
+ *
+ * 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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <assert.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+
+#include <osmocom/core/talloc.h>
+#include <osmocom/core/select.h>
+#include <osmo-bts/logging.h>
+#include <osmo-bts/gsm_data.h>
+#include <osmo-bts/pcu_if.h>
+#include <osmo-bts/pcuif_proto.h>
+#include <osmo-bts/bts.h>
+#include <osmo-bts/rsl.h>
+#include <osmo-bts/signal.h>
+#include <osmo-bts/bts_model.h>
+
+extern struct gsm_network bts_gsmnet;
+static int avail_lai = 0, avail_nse = 0, avail_cell = 0, avail_nsvc[2] = {0, 0};
+
+static const char *sapi_string[] = {
+	[PCU_IF_SAPI_RACH] =	"RACH",
+	[PCU_IF_SAPI_AGCH] =	"AGCH",
+	[PCU_IF_SAPI_PCH] =	"PCH",
+	[PCU_IF_SAPI_BCCH] =	"BCCH",
+	[PCU_IF_SAPI_PDTCH] =	"PDTCH",
+	[PCU_IF_SAPI_PRACH] =	"PRACH",
+	[PCU_IF_SAPI_PTCCH] = 	"PTCCH",
+};
+
+/* FIXME: common l1if include ? */
+int l1if_pdch_req(struct gsm_bts_trx_ts *ts, int is_ptcch, uint32_t fn,
+        uint16_t arfcn, uint8_t block_nr, uint8_t *data, uint8_t len);
+
+static int pcu_sock_send(struct gsm_network *net, struct msgb *msg);
+/* FIXME: move this to libosmocore */
+int osmo_unixsock_listen(struct osmo_fd *bfd, int type, const char *path);
+
+
+static struct gsm_bts_trx *trx_by_nr(struct gsm_bts *bts, uint8_t trx_nr)
+{
+	struct gsm_bts_trx *trx;
+
+	llist_for_each_entry(trx, &bts->trx_list, list) {
+		if (trx->nr == trx_nr)
+			return trx;
+	}
+
+	return NULL;
+}
+
+
+/*
+ * PCU messages
+ */
+
+struct msgb *pcu_msgb_alloc(uint8_t msg_type, uint8_t bts_nr)
+{
+	struct msgb *msg;
+	struct gsm_pcu_if *pcu_prim;
+
+	msg = msgb_alloc(sizeof(struct gsm_pcu_if), "pcu_sock_tx");
+	if (!msg)
+		return NULL;
+	msgb_put(msg, sizeof(struct gsm_pcu_if));
+	pcu_prim = (struct gsm_pcu_if *) msg->data;
+	pcu_prim->msg_type = msg_type; 
+	pcu_prim->bts_nr = bts_nr; 
+
+	return msg;
+}
+
+int pcu_tx_info_ind(void)
+{
+	struct gsm_network *net = &bts_gsmnet;
+	struct msgb *msg;
+	struct gsm_pcu_if *pcu_prim;
+	struct gsm_pcu_if_info_ind *info_ind;
+	struct gsm_bts *bts;
+	struct gprs_rlc_cfg *rlcc;
+	struct gsm_bts_gprs_nsvc *nsvc;
+	struct gsm_bts_trx *trx;
+	struct gsm_bts_trx_ts *ts;
+	int i, j;
+
+	LOGP(DPCU, LOGL_INFO, "Sending info\n");
+
+	/* FIXME: allow multiple BTS */
+	bts = llist_entry(net->bts_list.next, struct gsm_bts, list);
+	rlcc = &bts->gprs.cell.rlc_cfg;
+
+	msg = pcu_msgb_alloc(PCU_IF_MSG_INFO_IND, bts->nr);
+	if (!msg)
+		return -ENOMEM;
+	pcu_prim = (struct gsm_pcu_if *) msg->data;
+	info_ind = &pcu_prim->u.info_ind;
+
+	if (avail_lai && avail_nse && avail_cell && avail_nsvc[0]) {
+		info_ind->flags |= PCU_IF_FLAG_ACTIVE;
+		LOGP(DPCU, LOGL_INFO, "BTS is up\n");
+	} else
+		LOGP(DPCU, LOGL_INFO, "BTS is down\n");
+
+	/* RAI */
+	info_ind->mcc = net->mcc;
+	info_ind->mnc = net->mnc;
+	info_ind->lac = bts->location_area_code;
+	info_ind->rac = bts->gprs.rac;
+
+	/* NSE */
+	info_ind->nsei = bts->gprs.nse.nsei;
+	memcpy(info_ind->nse_timer, bts->gprs.nse.timer, 7);
+	memcpy(info_ind->cell_timer, bts->gprs.cell.timer, 11);
+
+	/* cell attributes */
+	info_ind->cell_id = bts->cell_identity;
+	info_ind->repeat_time = rlcc->paging.repeat_time;
+	info_ind->repeat_count = rlcc->paging.repeat_count;
+	info_ind->bvci = bts->gprs.cell.bvci;
+	info_ind->t3142 = rlcc->parameter[RLC_T3142];
+	info_ind->t3169 = rlcc->parameter[RLC_T3169];
+	info_ind->t3191 = rlcc->parameter[RLC_T3191];
+	info_ind->t3193_10ms = rlcc->parameter[RLC_T3193];
+	info_ind->t3195 = rlcc->parameter[RLC_T3195];
+	info_ind->n3101 = rlcc->parameter[RLC_N3101];
+	info_ind->n3103 = rlcc->parameter[RLC_N3103];
+	info_ind->n3105 = rlcc->parameter[RLC_N3105];
+	info_ind->cv_countdown = rlcc->parameter[CV_COUNTDOWN];
+	if (rlcc->cs_mask & (1 << GPRS_CS1))
+		info_ind->flags |= PCU_IF_FLAG_CS1;
+	if (rlcc->cs_mask & (1 << GPRS_CS2))
+		info_ind->flags |= PCU_IF_FLAG_CS2;
+	if (rlcc->cs_mask & (1 << GPRS_CS3))
+		info_ind->flags |= PCU_IF_FLAG_CS3;
+	if (rlcc->cs_mask & (1 << GPRS_CS4))
+		info_ind->flags |= PCU_IF_FLAG_CS4;
+	if (rlcc->cs_mask & (1 << GPRS_MCS1))
+		info_ind->flags |= PCU_IF_FLAG_MCS1;
+	if (rlcc->cs_mask & (1 << GPRS_MCS2))
+		info_ind->flags |= PCU_IF_FLAG_MCS2;
+	if (rlcc->cs_mask & (1 << GPRS_MCS3))
+		info_ind->flags |= PCU_IF_FLAG_MCS3;
+	if (rlcc->cs_mask & (1 << GPRS_MCS4))
+		info_ind->flags |= PCU_IF_FLAG_MCS4;
+	if (rlcc->cs_mask & (1 << GPRS_MCS5))
+		info_ind->flags |= PCU_IF_FLAG_MCS5;
+	if (rlcc->cs_mask & (1 << GPRS_MCS6))
+		info_ind->flags |= PCU_IF_FLAG_MCS6;
+	if (rlcc->cs_mask & (1 << GPRS_MCS7))
+		info_ind->flags |= PCU_IF_FLAG_MCS7;
+	if (rlcc->cs_mask & (1 << GPRS_MCS8))
+		info_ind->flags |= PCU_IF_FLAG_MCS8;
+	if (rlcc->cs_mask & (1 << GPRS_MCS9))
+		info_ind->flags |= PCU_IF_FLAG_MCS9;
+#warning	ist dl_tbf_ext nicht falsch?: * 10 und kein ntohs
+	info_ind->dl_tbf_ext = rlcc->parameter[T_DL_TBF_EXT];
+#warning	ist ul_tbf_ext nicht falsch?: * 10 und kein ntohs
+	info_ind->ul_tbf_ext = rlcc->parameter[T_UL_TBF_EXT];
+	info_ind->initial_cs = rlcc->initial_cs;
+	info_ind->initial_mcs = rlcc->initial_mcs;
+
+	/* NSVC */
+	for (i = 0; i < 2; i++) {
+		nsvc = &bts->gprs.nsvc[i];
+		info_ind->nsvci[i] = nsvc->nsvci;
+		info_ind->local_port[i] = nsvc->local_port;
+		info_ind->remote_port[i] = nsvc->remote_port;
+		info_ind->remote_ip[i] = nsvc->remote_ip;
+	}
+
+	for (i = 0; i < 8; i++) {
+		trx = trx_by_nr(bts, i);
+		if (!trx)
+			break;
+		info_ind->trx[i].pdch_mask = 0;
+		info_ind->trx[i].arfcn = trx->arfcn;
+		for (j = 0; j < 8; j++) {
+			ts = &trx->ts[j];
+			if (ts->mo.nm_state.operational == NM_OPSTATE_ENABLED
+			 && ts->pchan == GSM_PCHAN_PDCH) {
+				info_ind->trx[i].pdch_mask |= (1 << j);
+				info_ind->trx[i].tsc[j] =
+					(ts->tsc >= 0) ? ts->tsc : bts->tsc;
+				LOGP(DPCU, LOGL_INFO, "trx=%d ts=%d: "
+					"available (tsc=%d arfcn=%d)\n",
+					trx->nr, ts->nr,
+					info_ind->trx[i].tsc[j],
+					info_ind->trx[i].arfcn);
+			}
+		}
+	}
+
+	return pcu_sock_send(net, msg);
+}
+
+static int pcu_if_signal_cb(unsigned int subsys, unsigned int signal,
+	void *hdlr_data, void *signal_data)
+{
+	struct gsm_network *net = &bts_gsmnet;
+	struct gsm_bts_gprs_nsvc *nsvc;
+	struct gsm_bts *bts;
+	struct gsm48_system_information_type_3 *si3;
+	int id;
+
+	if (subsys != SS_GLOBAL)
+		return -EINVAL;
+
+	switch(signal) {
+	case S_NEW_SYSINFO:
+		bts = signal_data;
+		if (!(bts->si_valid & (1 << SYSINFO_TYPE_3)))
+			break;
+		si3 = (struct gsm48_system_information_type_3 *)
+						bts->si_buf[SYSINFO_TYPE_3];
+		net->mcc = ((si3->lai.digits[0] & 0x0f) << 8)
+			| (si3->lai.digits[0] & 0xf0)
+			| (si3->lai.digits[1] & 0x0f);
+		net->mnc = ((si3->lai.digits[2] & 0x0f) << 8)
+			| (si3->lai.digits[2] & 0xf0)
+			| ((si3->lai.digits[1] & 0xf0) >> 4);
+		if ((net->mnc & 0x00f) == 0x00f)
+			net->mnc >>= 4;
+		bts->location_area_code = ntohs(si3->lai.lac);
+		bts->cell_identity = si3->cell_identity;
+		avail_lai = 1;
+		break;
+	case S_NEW_NSE_ATTR:
+		bts = signal_data;
+		avail_nse = 1;
+		break;
+	case S_NEW_CELL_ATTR:
+		bts = signal_data;
+		avail_cell = 1;
+		break;
+	case S_NEW_NSVC_ATTR:
+		nsvc = signal_data;
+		id = nsvc->id;
+		if (id < 0 || id > 1)
+			return -EINVAL;
+		avail_nsvc[id] = 1;
+		break;
+	case S_NEW_OP_STATE:
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	/* If all infos have been received, of if one info is updated after
+	 * all infos have been received, transmit info update. */
+	if (avail_lai && avail_nse && avail_cell && avail_nsvc[0])
+		pcu_tx_info_ind();
+	return 0;
+}
+
+
+int pcu_tx_rts_req(struct gsm_bts_trx_ts *ts, uint8_t is_ptcch, uint32_t fn,
+	uint16_t arfcn, uint8_t block_nr)
+{
+	struct msgb *msg;
+	struct gsm_pcu_if *pcu_prim;
+	struct gsm_pcu_if_rts_req *rts_req;
+	struct gsm_bts *bts = ts->trx->bts;
+
+	LOGP(DPCU, LOGL_DEBUG, "Sending rts request: is_ptcch=%d arfcn=%d "
+		"block=%d\n", is_ptcch, arfcn, block_nr);
+
+	msg = pcu_msgb_alloc(PCU_IF_MSG_RTS_REQ, bts->nr);
+	if (!msg)
+		return -ENOMEM;
+	pcu_prim = (struct gsm_pcu_if *) msg->data;
+	rts_req = &pcu_prim->u.rts_req;
+
+	rts_req->sapi = (is_ptcch) ? PCU_IF_SAPI_PTCCH : PCU_IF_SAPI_PDTCH;
+	rts_req->fn = fn;
+	rts_req->arfcn = arfcn;
+	rts_req->trx_nr = ts->trx->nr;
+	rts_req->ts_nr = ts->nr;
+	rts_req->block_nr = block_nr;
+
+	return pcu_sock_send(&bts_gsmnet, msg);
+}
+
+int pcu_tx_data_ind(struct gsm_bts_trx_ts *ts, uint8_t is_ptcch, uint32_t fn,
+	uint16_t arfcn, uint8_t block_nr, uint8_t *data, uint8_t len)
+{
+	struct msgb *msg;
+	struct gsm_pcu_if *pcu_prim;
+	struct gsm_pcu_if_data *data_ind;
+	struct gsm_bts *bts = ts->trx->bts;
+
+	LOGP(DPCU, LOGL_DEBUG, "Sending data indication: is_ptcch=%d arfcn=%d "
+		"block=%d data=%s\n", is_ptcch, arfcn, block_nr,
+		osmo_hexdump(data, len));
+
+	msg = pcu_msgb_alloc(PCU_IF_MSG_DATA_IND, bts->nr);
+	if (!msg)
+		return -ENOMEM;
+	pcu_prim = (struct gsm_pcu_if *) msg->data;
+	data_ind = &pcu_prim->u.data_ind;
+
+	data_ind->sapi = (is_ptcch) ? PCU_IF_SAPI_PTCCH : PCU_IF_SAPI_PDTCH;
+	data_ind->fn = fn;
+	data_ind->arfcn = arfcn;
+	data_ind->trx_nr = ts->trx->nr;
+	data_ind->ts_nr = ts->nr;
+	data_ind->block_nr = block_nr;
+	memcpy(data_ind->data, data, len);
+	data_ind->len = len;
+
+	return pcu_sock_send(&bts_gsmnet, msg);
+}
+
+int pcu_tx_rach_ind(struct gsm_bts *bts, int16_t qta, uint8_t ra, uint32_t fn)
+{
+	struct msgb *msg;
+	struct gsm_pcu_if *pcu_prim;
+	struct gsm_pcu_if_rach_ind *rach_ind;
+
+	LOGP(DPCU, LOGL_INFO, "Sending RACH indication: qta=%d, ra=%d, "
+		"fn=%d\n", qta, ra, fn);
+
+	msg = pcu_msgb_alloc(PCU_IF_MSG_RACH_IND, bts->nr);
+	if (!msg)
+		return -ENOMEM;
+	pcu_prim = (struct gsm_pcu_if *) msg->data;
+	rach_ind = &pcu_prim->u.rach_ind;
+
+	rach_ind->sapi = PCU_IF_SAPI_RACH;
+	rach_ind->ra = ra;
+	rach_ind->qta = qta;
+	rach_ind->fn = fn;
+
+	return pcu_sock_send(&bts_gsmnet, msg);
+}
+
+int pcu_tx_time_ind(uint32_t fn)
+{
+	struct msgb *msg;
+	struct gsm_pcu_if *pcu_prim;
+	struct gsm_pcu_if_time_ind *time_ind;
+	uint8_t fn13 = fn % 13;
+
+	/* omit frame numbers not starting at a MAC block */
+	if (fn13 != 0 && fn13 != 4 && fn13 != 8)
+		return 0;
+
+	msg = pcu_msgb_alloc(PCU_IF_MSG_TIME_IND, 0);
+	if (!msg)
+		return -ENOMEM;
+	pcu_prim = (struct gsm_pcu_if *) msg->data;
+	time_ind = &pcu_prim->u.time_ind;
+
+	time_ind->fn = fn;
+
+	return pcu_sock_send(&bts_gsmnet, msg);
+}
+
+static int pcu_rx_data_req(struct gsm_bts *bts, uint8_t msg_type,
+	struct gsm_pcu_if_data *data_req)
+{
+	uint8_t is_ptcch;
+	struct gsm_bts_trx *trx;
+	struct gsm_bts_trx_ts *ts;
+	struct msgb *msg;
+	int rc = 0;
+
+	LOGP(DPCU, LOGL_DEBUG, "Data request received: sapi=%s arfcn=%d "
+		"block=%d data=%s\n", sapi_string[data_req->sapi],
+		data_req->arfcn, data_req->block_nr,
+		osmo_hexdump(data_req->data, data_req->len));
+
+	switch (data_req->sapi) {
+	case PCU_IF_SAPI_BCCH:
+		if (data_req->len == 23) {
+			bts->si_valid |= (1 << SYSINFO_TYPE_13);
+			memcpy(bts->si_buf[SYSINFO_TYPE_13], data_req->data,
+				data_req->len);
+		} else {
+			bts->si_valid &= ~(1 << SYSINFO_TYPE_13);
+		}
+		osmo_signal_dispatch(SS_GLOBAL, S_NEW_SYSINFO, bts);
+		break;
+	case PCU_IF_SAPI_PCH:
+		if (msg_type == PCU_IF_MSG_PAG_REQ) {
+			/* FIXME: Add function to schedule paging request.
+			 * This might not be required, if PCU_IF_MSG_DATA_REQ
+			 * is used instead. */
+		} else {
+			struct gsm_bts_role_bts *btsb = bts->role;
+
+			paging_add_imm_ass(btsb->paging_state, data_req->data,
+				data_req->len);
+		}
+		break;
+	case PCU_IF_SAPI_AGCH:
+		msg = msgb_alloc(data_req->len, "pcu_agch");
+		if (!msg) {
+			rc = -ENOMEM;
+			break;
+		}
+		memcpy(msgb_put(msg, data_req->len), data_req->data, data_req->len);
+		if (bts_agch_enqueue(bts, msg) < 0) {
+			msgb_free(msg);
+			rc = -EIO;
+		}
+		break;
+	case PCU_IF_SAPI_PDTCH:
+	case PCU_IF_SAPI_PTCCH:
+		trx = trx_by_nr(bts, data_req->trx_nr);
+		if (!trx) {
+			LOGP(DPCU, LOGL_ERROR, "Received PCU data request with "
+				"not existing TRX %d\n", data_req->trx_nr);
+			rc = -EINVAL;
+			break;
+		}
+		ts = &trx->ts[data_req->ts_nr];
+		is_ptcch = (data_req->sapi == PCU_IF_SAPI_PTCCH);
+		rc = l1if_pdch_req(ts, is_ptcch, data_req->fn, data_req->arfcn,
+			data_req->block_nr, data_req->data, data_req->len);
+		break;
+	default:
+		LOGP(DPCU, LOGL_ERROR, "Received PCU data request with "
+			"unsupported sapi %d\n", data_req->sapi);
+		rc = -EINVAL;
+	}
+
+	return rc;
+}
+
+static int pcu_rx_act_req(struct gsm_bts *bts,
+	struct gsm_pcu_if_act_req *act_req)
+{
+	struct gsm_bts_trx *trx;
+	struct gsm_lchan *lchan;
+
+	LOGP(DPCU, LOGL_INFO, "%s request received: TRX=%d TX=%d\n", 
+		(act_req->activate) ? "Activate" : "Deactivate",
+		act_req->trx_nr, act_req->ts_nr);
+
+	trx = trx_by_nr(bts, act_req->trx_nr);
+	if (!trx || act_req->ts_nr >= 8)
+		return -EINVAL;
+
+	lchan = trx->ts[act_req->ts_nr].lchan;
+	if (lchan->type != GSM_LCHAN_PDTCH) {
+		LOGP(DPCU, LOGL_ERROR, "Lchan is not of type PDCH, but %d.\n",
+			lchan->type);
+		return -EINVAL;
+	}
+	if (act_req->activate)
+		bts_model_rsl_chan_act(lchan, NULL);
+	else
+		bts_model_rsl_chan_rel(lchan);
+
+	return 0;
+}
+
+static int pcu_rx(struct gsm_network *net, uint8_t msg_type,
+	struct gsm_pcu_if *pcu_prim)
+{
+	int rc = 0;
+	struct gsm_bts *bts;
+
+	/* FIXME: allow multiple BTS */
+	bts = llist_entry(net->bts_list.next, struct gsm_bts, list);
+
+	switch (msg_type) {
+	case PCU_IF_MSG_DATA_REQ:
+	case PCU_IF_MSG_PAG_REQ:
+		rc = pcu_rx_data_req(bts, msg_type, &pcu_prim->u.data_req);
+		break;
+	case PCU_IF_MSG_ACT_REQ:
+		rc = pcu_rx_act_req(bts, &pcu_prim->u.act_req);
+		break;
+	default:
+		LOGP(DPCU, LOGL_ERROR, "Received unknwon PCU msg type %d\n",
+			msg_type);
+		rc = -EINVAL;
+	}
+
+	return rc;
+}
+
+/*
+ * PCU socket interface
+ */
+
+struct pcu_sock_state {
+	struct gsm_network *net;
+	struct osmo_fd listen_bfd;	/* fd for listen socket */
+	struct osmo_fd conn_bfd;	/* fd for connection to lcr */
+	struct llist_head upqueue;	/* queue for sending messages */
+};
+
+static int pcu_sock_send(struct gsm_network *net, struct msgb *msg)
+{
+	struct pcu_sock_state *state = net->pcu_state;
+	struct osmo_fd *conn_bfd;
+	struct gsm_pcu_if *pcu_prim = (struct gsm_pcu_if *) msg->data;
+
+	if (!state) {
+		if (pcu_prim->msg_type != PCU_IF_MSG_TIME_IND)
+			LOGP(DPCU, LOGL_INFO, "PCU socket not created, "
+				"dropping message\n");
+		return -EINVAL;
+	}
+	conn_bfd = &state->conn_bfd;
+	if (conn_bfd->fd <= 0) {
+		if (pcu_prim->msg_type != PCU_IF_MSG_TIME_IND)
+			LOGP(DPCU, LOGL_NOTICE, "PCU socket not connected, "
+				"dropping message\n");
+		return -EIO;
+	}
+	msgb_enqueue(&state->upqueue, msg);
+	conn_bfd->when |= BSC_FD_WRITE;
+
+	return 0;
+}
+
+static void pcu_sock_close(struct pcu_sock_state *state)
+{
+	struct osmo_fd *bfd = &state->conn_bfd;
+	struct gsm_bts *bts;
+	struct gsm_bts_trx *trx;
+	struct gsm_bts_trx_ts *ts;
+	int i, j;
+
+	/* FIXME: allow multiple BTS */
+	bts = llist_entry(state->net->bts_list.next, struct gsm_bts, list);
+
+	LOGP(DPCU, LOGL_NOTICE, "PCU socket has LOST connection\n");
+
+	close(bfd->fd);
+	bfd->fd = -1;
+	osmo_fd_unregister(bfd);
+
+	/* re-enable the generation of ACCEPT for new connections */
+	state->listen_bfd.when |= BSC_FD_READ;
+
+#if 0
+	/* remove si13, ... */
+	bts->si_valid &= ~(1 << SYSINFO_TYPE_13);
+	osmo_signal_dispatch(SS_GLOBAL, S_NEW_SYSINFO, bts);
+#endif
+
+	/* release PDCH */
+	for (i = 0; i < 8; i++) {
+		trx = trx_by_nr(bts, i);
+		if (!trx)
+			break;
+		for (j = 0; j < 8; j++) {
+			ts = &trx->ts[j];
+			if (ts->mo.nm_state.operational == NM_OPSTATE_ENABLED
+			 && ts->pchan == GSM_PCHAN_PDCH)
+				bts_model_rsl_chan_rel(ts->lchan);
+		}
+	}
+
+	/* flush the queue */
+	while (!llist_empty(&state->upqueue)) {
+		struct msgb *msg = msgb_dequeue(&state->upqueue);
+		msgb_free(msg);
+	}
+}
+
+static int pcu_sock_read(struct osmo_fd *bfd)
+{
+	struct pcu_sock_state *state = (struct pcu_sock_state *)bfd->data;
+	struct gsm_pcu_if *pcu_prim;
+	struct msgb *msg;
+	int rc;
+
+	msg = msgb_alloc(sizeof(*pcu_prim), "pcu_sock_rx");
+	if (!msg)
+		return -ENOMEM;
+
+	pcu_prim = (struct gsm_pcu_if *) msg->tail;
+
+	rc = recv(bfd->fd, msg->tail, msgb_tailroom(msg), 0);
+	if (rc == 0)
+		goto close;
+
+	if (rc < 0) {
+		if (errno == EAGAIN)
+			return 0;
+		goto close;
+	}
+
+	rc = pcu_rx(state->net, pcu_prim->msg_type, pcu_prim);
+
+	/* as we always synchronously process the message in pcu_rx() and
+	 * its callbacks, we can free the message here. */
+	msgb_free(msg);
+
+	return rc;
+
+close:
+	msgb_free(msg);
+	pcu_sock_close(state);
+	return -1;
+}
+
+static int pcu_sock_write(struct osmo_fd *bfd)
+{
+	struct pcu_sock_state *state = bfd->data;
+	int rc;
+
+	while (!llist_empty(&state->upqueue)) {
+		struct msgb *msg, *msg2;
+		struct gsm_pcu_if *pcu_prim;
+
+		/* peek at the beginning of the queue */
+		msg = llist_entry(state->upqueue.next, struct msgb, list);
+		pcu_prim = (struct gsm_pcu_if *)msg->data;
+
+		bfd->when &= ~BSC_FD_WRITE;
+
+		/* bug hunter 8-): maybe someone forgot msgb_put(...) ? */
+		if (!msgb_length(msg)) {
+			LOGP(DPCU, LOGL_ERROR, "message type (%d) with ZERO "
+				"bytes!\n", pcu_prim->msg_type);
+			goto dontsend;
+		}
+
+		/* try to send it over the socket */
+		rc = write(bfd->fd, msgb_data(msg), msgb_length(msg));
+		if (rc == 0)
+			goto close;
+		if (rc < 0) {
+			if (errno == EAGAIN) {
+				bfd->when |= BSC_FD_WRITE;
+				break;
+			}
+			goto close;
+		}
+
+dontsend:
+		/* _after_ we send it, we can deueue */
+		msg2 = msgb_dequeue(&state->upqueue);
+		assert(msg == msg2);
+		msgb_free(msg);
+	}
+	return 0;
+
+close:
+	pcu_sock_close(state);
+
+	return -1;
+}
+
+static int pcu_sock_cb(struct osmo_fd *bfd, unsigned int flags)
+{
+	int rc = 0;
+
+	if (flags & BSC_FD_READ)
+		rc = pcu_sock_read(bfd);
+	if (rc < 0)
+		return rc;
+
+	if (flags & BSC_FD_WRITE)
+		rc = pcu_sock_write(bfd);
+
+	return rc;
+}
+
+/* accept connection comming from PCU */
+static int pcu_sock_accept(struct osmo_fd *bfd, unsigned int flags)
+{
+	struct pcu_sock_state *state = (struct pcu_sock_state *)bfd->data;
+	struct osmo_fd *conn_bfd = &state->conn_bfd;
+	struct sockaddr_un un_addr;
+	socklen_t len;
+	int rc;
+
+	len = sizeof(un_addr);
+	rc = accept(bfd->fd, (struct sockaddr *) &un_addr, &len);
+	if (rc < 0) {
+		LOGP(DPCU, LOGL_ERROR, "Failed to accept a new connection\n");
+		return -1;
+	}
+
+	if (conn_bfd->fd >= 0) {
+		LOGP(DPCU, LOGL_NOTICE, "PCU connects but we already have "
+			"another active connection ?!?\n");
+		/* We already have one PCU connected, this is all we support */
+		state->listen_bfd.when &= ~BSC_FD_READ;
+		close(rc);
+		return 0;
+	}
+
+	conn_bfd->fd = rc;
+	conn_bfd->when = BSC_FD_READ;
+	conn_bfd->cb = pcu_sock_cb;
+	conn_bfd->data = state;
+
+	if (osmo_fd_register(conn_bfd) != 0) {
+		LOGP(DPCU, LOGL_ERROR, "Failed to register new connection "
+			"fd\n");
+		close(conn_bfd->fd);
+		conn_bfd->fd = -1;
+		return -1;
+	}
+
+	LOGP(DPCU, LOGL_NOTICE, "PCU socket has connection with external "
+		"call control application\n");
+
+	/* send current info */
+	pcu_tx_info_ind();
+
+	return 0;
+}
+
+int pcu_sock_init(void)
+{
+	struct pcu_sock_state *state;
+	struct osmo_fd *bfd;
+	int rc;
+
+	state = talloc_zero(NULL, struct pcu_sock_state);
+	if (!state)
+		return -ENOMEM;
+
+	INIT_LLIST_HEAD(&state->upqueue);
+	state->net = &bts_gsmnet;
+	state->conn_bfd.fd = -1;
+
+	bfd = &state->listen_bfd;
+
+	rc = osmo_unixsock_listen(bfd, SOCK_SEQPACKET, "/tmp/pcu_bts");
+	if (rc < 0) {
+		LOGP(DPCU, LOGL_ERROR, "Could not create unix socket: %s\n",
+			strerror(errno));
+		talloc_free(state);
+		return rc;
+	}
+
+	bfd->when = BSC_FD_READ;
+	bfd->cb = pcu_sock_accept;
+	bfd->data = state;
+
+	rc = osmo_fd_register(bfd);
+	if (rc < 0) {
+		LOGP(DPCU, LOGL_ERROR, "Could not register listen fd: %d\n",
+			rc);
+		close(bfd->fd);
+		talloc_free(state);
+		return rc;
+	}
+
+	osmo_signal_register_handler(SS_GLOBAL, pcu_if_signal_cb, NULL);
+
+	bts_gsmnet.pcu_state = state;
+
+	return 0;
+}
+
+void pcu_sock_exit(void)
+{
+	struct pcu_sock_state *state = bts_gsmnet.pcu_state;
+	struct osmo_fd *bfd, *conn_bfd;
+
+	if (!state)
+		return;
+
+	osmo_signal_unregister_handler(SS_GLOBAL, pcu_if_signal_cb, NULL);
+	conn_bfd = &state->conn_bfd;
+	if (conn_bfd->fd > 0)
+		pcu_sock_close(state);
+	bfd = &state->listen_bfd;
+	close(bfd->fd);
+	osmo_fd_unregister(bfd);
+	talloc_free(state);
+	bts_gsmnet.pcu_state = NULL;
+}
+
+/* FIXME: move this to libosmocore */
+int osmo_unixsock_listen(struct osmo_fd *bfd, int type, const char *path)
+{
+	struct sockaddr_un local;
+	unsigned int namelen;
+	int rc;
+
+	bfd->fd = socket(AF_UNIX, type, 0);
+
+	if (bfd->fd < 0) {
+		fprintf(stderr, "Failed to create Unix Domain Socket.\n");
+		return -1;
+	}
+
+	local.sun_family = AF_UNIX;
+	strncpy(local.sun_path, path, sizeof(local.sun_path));
+	local.sun_path[sizeof(local.sun_path) - 1] = '\0';
+	unlink(local.sun_path);
+
+	/* we use the same magic that X11 uses in Xtranssock.c for
+	 * calculating the proper length of the sockaddr */
+#if defined(BSD44SOCKETS) || defined(__UNIXWARE__)
+	local.sun_len = strlen(local.sun_path);
+#endif
+#if defined(BSD44SOCKETS) || defined(SUN_LEN)
+	namelen = SUN_LEN(&local);
+#else
+	namelen = strlen(local.sun_path) +
+		  offsetof(struct sockaddr_un, sun_path);
+#endif
+
+	rc = bind(bfd->fd, (struct sockaddr *) &local, namelen);
+	if (rc != 0) {
+		fprintf(stderr, "Failed to bind the unix domain socket. '%s'\n",
+			local.sun_path);
+		close(bfd->fd);
+		bfd->fd = -1;
+		return -1;
+	}
+
+	if (listen(bfd->fd, 0) != 0) {
+		fprintf(stderr, "Failed to listen.\n");
+		close(bfd->fd);
+		bfd->fd = -1;
+		return -1;
+	}
+
+	return 0;
+}
+
diff --git a/src/osmo-bts-sysmo/l1_if.c b/src/osmo-bts-sysmo/l1_if.c
index d9049a94..d564e2e7 100644
--- a/src/osmo-bts-sysmo/l1_if.c
+++ b/src/osmo-bts-sysmo/l1_if.c
@@ -45,6 +45,7 @@
 #include <osmo-bts/gsm_data.h>
 #include <osmo-bts/paging.h>
 #include <osmo-bts/measurement.h>
+#include <osmo-bts/pcu_if.h>
 
 #include <sysmocom/femtobts/superfemto.h>
 #include <sysmocom/femtobts/gsml1prim.h>
@@ -505,14 +506,13 @@ static int handle_ph_readytosend_ind(struct femtol1_hdl *fl1,
 			msgb_free(pp.oph.msg);
 		}
 		break;
-		/* we should never receive a request here */
 	case GsmL1_Sapi_Pdtch:
-		msu_param->u8Size = pdch_msu_size[PDCH_MCS_9];
-		memset(msu_param->u8Buffer, 0, msu_param->u8Size);
-		/* FIXME: copy actual data */
-		break;
 	case GsmL1_Sapi_Pacch:
+		return pcu_tx_rts_req(&trx->ts[rts_ind->u8Tn], 0,
+			rts_ind->u32Fn, rts_ind->u16Arfcn, rts_ind->u8BlockNbr);
 	case GsmL1_Sapi_Ptcch:
+		return pcu_tx_rts_req(&trx->ts[rts_ind->u8Tn], 1,
+			rts_ind->u32Fn, rts_ind->u16Arfcn, rts_ind->u8BlockNbr);
 	case GsmL1_Sapi_Prach:
 		goto empty_frame;
 		break;
@@ -545,6 +545,9 @@ static int handle_mph_time_ind(struct femtol1_hdl *fl1,
 
 	int frames_expired = time_ind->u32Fn - fl1->gsm_time.fn;
 
+	/* update time on PCU interface */
+	pcu_tx_time_ind(time_ind->u32Fn);
+
 	/* Update our data structures with the current GSM time */
 	gsm_fn2gsmtime(&fl1->gsm_time, time_ind->u32Fn);
 
@@ -613,6 +616,7 @@ static int process_meas_res(struct gsm_lchan *lchan, GsmL1_MeasParam_t *m)
 static int handle_ph_data_ind(struct femtol1_hdl *fl1, GsmL1_PhDataInd_t *data_ind,
 			      struct msgb *l1p_msg)
 {
+	struct gsm_bts_trx *trx = fl1->priv;
 	struct osmo_phsap_prim pp;
 	struct gsm_lchan *lchan;
 	struct lapdm_entity *le;
@@ -688,6 +692,27 @@ static int handle_ph_data_ind(struct femtol1_hdl *fl1, GsmL1_PhDataInd_t *data_i
 		/* TCH speech frame handling */
 		rc = l1if_tch_rx(lchan, l1p_msg);
 		break;
+	case GsmL1_Sapi_Pdtch:
+	case GsmL1_Sapi_Pacch:
+		/* drop incomplete UL block */
+		if (data_ind->msgUnitParam.u8Buffer[0]
+			!= GsmL1_PdtchPlType_Full)
+			break;
+		/* PDTCH / PACCH frame handling */
+		rc = pcu_tx_data_ind(&trx->ts[data_ind->u8Tn], 0,
+			data_ind->u32Fn, data_ind->u16Arfcn,
+			data_ind->u8BlockNbr,
+			data_ind->msgUnitParam.u8Buffer + 1,
+			data_ind->msgUnitParam.u8Size - 1);
+		break;
+	case GsmL1_Sapi_Ptcch:
+		/* PTCCH frame handling */
+		rc = pcu_tx_data_ind(&trx->ts[data_ind->u8Tn], 1,
+			data_ind->u32Fn, data_ind->u16Arfcn,
+			data_ind->u8BlockNbr,
+			data_ind->msgUnitParam.u8Buffer,
+			data_ind->msgUnitParam.u8Size);
+		break;
 	default:
 		LOGP(DL1C, LOGL_NOTICE, "Rx PH-DATA.ind for unknown L1 SAPI %s\n",
 			get_value_string(femtobts_l1sapi_names, data_ind->sapi));
@@ -728,11 +753,6 @@ static int handle_ph_ra_ind(struct femtol1_hdl *fl1, GsmL1_PhRaInd_t *ra_ind)
 		return -ENODEV;
 	}
 
-	osmo_prim_init(&pp.oph, SAP_GSM_PH, PRIM_PH_RACH,
-			PRIM_OP_INDICATION, NULL);
-
-	pp.u.rach_ind.ra = ra_ind->msgUnitParam.u8Buffer[0];
-	pp.u.rach_ind.fn = ra_ind->u32Fn;
 	/* check for under/overflow / sign */
 	if (ra_ind->measParam.i16BurstTiming < 0)
 		acc_delay = 0;
@@ -743,6 +763,20 @@ static int handle_ph_ra_ind(struct femtol1_hdl *fl1, GsmL1_PhRaInd_t *ra_ind)
 		     acc_delay, btsb->max_ta);
 		return 0;
 	}
+
+	/* check for packet access */
+	if (trx == bts->c0
+	 && (ra_ind->msgUnitParam.u8Buffer[0] & 0xf0) == 0x70) {
+		LOGP(DL1C, LOGL_INFO, "RACH for packet access\n");
+		return pcu_tx_rach_ind(bts, ra_ind->measParam.i16BurstTiming,
+			ra_ind->msgUnitParam.u8Buffer[0], ra_ind->u32Fn);
+	}
+
+	osmo_prim_init(&pp.oph, SAP_GSM_PH, PRIM_PH_RACH,
+			PRIM_OP_INDICATION, NULL);
+
+	pp.u.rach_ind.ra = ra_ind->msgUnitParam.u8Buffer[0];
+	pp.u.rach_ind.fn = ra_ind->u32Fn;
 	pp.u.rach_ind.acc_delay = acc_delay;
 
 	return lapdm_phsap_up(&pp.oph, &lc->lapdm_dcch);
@@ -1046,6 +1080,46 @@ int l1if_set_trace_flags(struct femtol1_hdl *hdl, uint32_t flags)
 	return osmo_wqueue_enqueue(&hdl->write_q[MQ_SYS_WRITE], msg);
 }
 
+/* send packet data request to L1 */
+int l1if_pdch_req(struct gsm_bts_trx_ts *ts, int is_ptcch, uint32_t fn,
+	uint16_t arfcn, uint8_t block_nr, uint8_t *data, uint8_t len)
+{
+	struct gsm_bts_trx *trx = ts->trx;
+	struct femtol1_hdl *fl1h = trx_femtol1_hdl(trx);
+	struct msgb *msg;
+	GsmL1_Prim_t *l1p;
+	GsmL1_PhDataReq_t *data_req;
+	GsmL1_MsgUnitParam_t *msu_param;
+	struct gsm_time g_time;
+
+	gsm_fn2gsmtime(&g_time, fn);
+
+	DEBUGP(DL1P, "TX packet data %02u/%02u/%02u is_ptcch=%d trx=%d ts=%d "
+		"block_nr=%d, arfcn=%d, len=%d\n", g_time.t1, g_time.t2,
+		g_time.t3, is_ptcch, ts->trx->nr, ts->nr, block_nr, arfcn, len);
+
+	msg = l1p_msgb_alloc();
+	l1p = msgb_l1prim(msg);
+	l1p->id = GsmL1_PrimId_PhDataReq;
+	data_req = &l1p->u.phDataReq;
+	data_req->hLayer1 = fl1h->hLayer1;
+	data_req->sapi = (is_ptcch) ? GsmL1_Sapi_Ptcch : GsmL1_Sapi_Pdtch;
+	data_req->subCh = GsmL1_SubCh_NA;
+	data_req->u8BlockNbr = block_nr;
+	data_req->u8Tn = ts->nr;
+	data_req->u32Fn = fn;
+	msu_param = &data_req->msgUnitParam;
+	msu_param->u8Size = len;
+	memcpy(msu_param->u8Buffer, data, len);
+
+	tx_to_gsmtap(fl1h, msg);
+
+	/* transmit */
+	osmo_wqueue_enqueue(&fl1h->write_q[MQ_L1_WRITE], msg);
+
+	return 0;
+}
+
 struct femtol1_hdl *l1if_open(void *priv)
 {
 	struct femtol1_hdl *fl1h;
diff --git a/src/osmo-bts-sysmo/main.c b/src/osmo-bts-sysmo/main.c
index 03db2382..2203309d 100644
--- a/src/osmo-bts-sysmo/main.c
+++ b/src/osmo-bts-sysmo/main.c
@@ -43,6 +43,7 @@
 #include <osmo-bts/bts.h>
 #include <osmo-bts/vty.h>
 #include <osmo-bts/bts_model.h>
+#include <osmo-bts/pcu_if.h>
 
 #define SYSMOBTS_RF_LOCK_PATH	"/var/lock/bts_rf_lock"
 
@@ -50,6 +51,7 @@
 
 /* FIXME: read from real hardware */
 const uint8_t abis_mac[6] = { 0,1,2,3,4,5 };
+int gprs_enabled = 0;
 
 static const char *config_file = "osmo-bts.cfg";
 static int daemonize = 0;
@@ -107,6 +109,7 @@ static void print_help()
 		"  -e 	--log-level	Set a global log-level\n"
 		"  -p	--dsp-trace	Set DSP trace flags\n"
 		"  -w	--hw-version	Print the targeted HW Version\n"
+		"  -P	--pcu		Enable PCU L1 socket interface\n"
 		);
 }
 
@@ -136,10 +139,11 @@ static void handle_options(int argc, char **argv)
 			{ "log-level", 1, 0, 'e' },
 			{ "dsp-trace", 1, 0, 'p' },
 			{ "hw-version", 0, 0, 'w' },
+			{ "pcu", 0, 0, 'P' },
 			{ 0, 0, 0, 0 }
 		};
 
-		c = getopt_long(argc, argv, "hc:d:Dc:sTVe:p:w",
+		c = getopt_long(argc, argv, "hc:d:Dc:sTVe:p:w:P",
 				long_options, &option_idx);
 		if (c == -1)
 			break;
@@ -164,6 +168,13 @@ static void handle_options(int argc, char **argv)
 		case 'T':
 			log_set_print_timestamp(osmo_stderr_target, 1);
 			break;
+		case 'P':
+			if (pcu_sock_init()) {
+				fprintf(stderr, "PCU L1 socket failed\n");
+				exit(-1);
+			}
+			gprs_enabled = 1;
+			break;
 		case 'V':
 			print_version(1);
 			exit(0);