re-work original osmo-bts with support for sysmocom femtobts

This code re-works osmo-bts to add support for the upcoming sysmocom BTS.

It also tries to add some level of abstraction between the generic
part of a BTS (A-bis, RSL, OML, data structures, paging scheduling,
BCCH/AGCH scheduling, etc.) and the actual hardware-specific bits.

The hardware-specific bits are currently only implemented for the sysmocom
femtobts, but should be (re-)added for osmocom-bb, as well as a virtual
BTS for simulation purpose later.

The sysmocom bts specific parts require hardware-specific header files
which are (at least currently) not publicly distributed.

1 files changed, 205 insertions, 0 deletions

diff --git a/src/osmo-bts-sysmo/l1_fwd_main.c b/src/osmo-bts-sysmo/l1_fwd_main.c
new file mode 100644
index 00000000..c7bdcdf5
--- /dev/null
+++ b/src/osmo-bts-sysmo/l1_fwd_main.c
@@ -0,0 +1,205 @@
+/* Sysmocom femtobts L1 proxy */
+
+/* (C) 2011 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 <stdint.h>
+#include <unistd.h>
+#include <errno.h>
+#include <fcntl.h>
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+
+#include <arpa/inet.h>
+#include <netinet/in.h>
+
+#include <osmocom/core/talloc.h>
+#include <osmocom/core/utils.h>
+#include <osmocom/core/select.h>
+#include <osmocom/core/write_queue.h>
+#include <osmocom/core/logging.h>
+#include <osmocom/core/socket.h>
+#include <osmocom/gsm/gsm_utils.h>
+
+#include <osmo-bts/logging.h>
+#include <osmo-bts/gsm_data.h>
+
+#include <sysmocom/femtobts/femtobts.h>
+#include <sysmocom/femtobts/gsml1prim.h>
+#include <sysmocom/femtobts/gsml1const.h>
+#include <sysmocom/femtobts/gsml1types.h>
+
+#include "femtobts.h"
+#include "l1_if.h"
+#include "l1_fwd.h"
+
+static const uint16_t fwd_udp_ports[_NUM_MQ_WRITE] = {
+	[MQ_SYS_READ]	= L1FWD_SYS_PORT,
+	[MQ_L1_READ]	= L1FWD_L1_PORT,
+};
+
+struct l1fwd_hdl {
+	struct sockaddr_storage remote_sa;
+	socklen_t remote_sa_len;
+
+	struct osmo_wqueue udp_wq[_NUM_MQ_WRITE];
+
+	struct femtol1_hdl *fl1h;
+};
+
+
+/* callback when there's a new L1 primitive coming in from the HW */
+int l1if_handle_l1prim(struct femtol1_hdl *fl1h, struct msgb *msg)
+{
+	struct l1fwd_hdl *l1fh = fl1h->priv;
+
+	/* Enqueue message to UDP socket */
+	return osmo_wqueue_enqueue(&l1fh->udp_wq[MQ_L1_WRITE], msg);
+}
+
+/* callback when there's a new SYS primitive coming in from the HW */
+int l1if_handle_sysprim(struct femtol1_hdl *fl1h, struct msgb *msg)
+{
+	struct l1fwd_hdl *l1fh = fl1h->priv;
+
+	/* Enqueue message to UDP socket */
+	return osmo_wqueue_enqueue(&l1fh->udp_wq[MQ_SYS_WRITE], msg);
+}
+
+
+/* data has arrived on the udp socket */
+static int udp_read_cb(struct osmo_fd *ofd)
+{
+	struct msgb *msg = msgb_alloc_headroom(2048, 128, "udp_rx");
+	struct l1fwd_hdl *l1fh = ofd->data;
+	struct femtol1_hdl *fl1h = l1fh->fl1h;
+	int rc;
+
+	if (!msg)
+		return -ENOMEM;
+
+	msg->l1h = msg->data;
+
+	l1fh->remote_sa_len = sizeof(l1fh->remote_sa);
+	rc = recvfrom(ofd->fd, msg->l1h, msgb_tailroom(msg), 0,
+		      (struct sockaddr *) &l1fh->remote_sa, &l1fh->remote_sa_len);
+	if (rc < 0) {
+		perror("read from udp");
+		msgb_free(msg);
+		return rc;
+	} else if (rc == 0) {
+		perror("len=0 read from udp");
+		msgb_free(msg);	
+		return rc;
+	}
+	msgb_put(msg, rc);
+
+	DEBUGP(DL1C, "UDP: Received %u bytes for %s queue\n", rc,
+		ofd->priv_nr == MQ_SYS_WRITE ? "SYS" : "L1");
+
+	/* put the message into the right queue */
+	if (ofd->priv_nr == MQ_SYS_WRITE)
+		rc = osmo_wqueue_enqueue(&fl1h->write_q[MQ_SYS_WRITE], msg);
+	else
+		rc = osmo_wqueue_enqueue(&fl1h->write_q[MQ_L1_WRITE], msg);
+	
+	return rc;
+}
+
+/* callback when we can write to the UDP socket */
+static int udp_write_cb(struct osmo_fd *ofd, struct msgb *msg)
+{
+	int rc;
+	struct l1fwd_hdl *l1fh = ofd->data;
+
+	DEBUGP(DL1C, "UDP: Writing %u bytes for %s queue\n", msgb_l1len(msg),
+		ofd->priv_nr == MQ_SYS_WRITE ? "SYS" : "L1");
+
+	rc = sendto(ofd->fd, msg->l1h, msgb_l1len(msg), 0,
+		    (const struct sockaddr *)&l1fh->remote_sa, l1fh->remote_sa_len);
+	if (rc < 0) {
+		LOGP(DL1C, LOGL_ERROR, "error writing to L1 msg_queue: %s\n",
+			strerror(errno));
+		return rc;
+	} else if (rc < msgb_l1len(msg)) {
+		LOGP(DL1C, LOGL_ERROR, "short write to L1 msg_queue: "
+			"%u < %u\n", rc, msgb_l1len(msg));
+		return -EIO;
+	}
+
+	return 0;
+}
+
+int main(int argc, char **argv)
+{
+	struct l1fwd_hdl *l1fh;
+	struct femtol1_hdl *fl1h;
+	int rc, i;
+
+	printf("sizeof(GsmL1_Prim_t) = %lu\n", sizeof(GsmL1_Prim_t));
+	printf("sizeof(FemtoBts_Prim_t) = %lu\n", sizeof(FemtoBts_Prim_t));
+
+	bts_log_init(NULL);
+
+	/* allocate new femtol1_handle */
+	fl1h = talloc_zero(NULL, struct femtol1_hdl);
+	INIT_LLIST_HEAD(&fl1h->wlc_list);
+
+	/* open the actual hardware transport */
+	rc = l1if_transport_open(fl1h);
+	if (rc < 0)
+		exit(1);
+
+	/* create our fwd handle */
+	l1fh = talloc_zero(NULL, struct l1fwd_hdl);
+
+	l1fh->fl1h = fl1h;
+	fl1h->priv = l1fh;
+
+	/* Open UDP */
+	for (i = 0; i < 2; i++) {
+		struct osmo_wqueue *wq = &l1fh->udp_wq[i];
+
+		osmo_wqueue_init(wq, 10);
+		wq->write_cb = udp_write_cb;
+		wq->read_cb = udp_read_cb;
+
+		wq->bfd.when |= BSC_FD_READ;
+		wq->bfd.data = l1fh;
+		wq->bfd.priv_nr = i;
+		rc = osmo_sock_init_ofd(&wq->bfd, AF_UNSPEC, SOCK_DGRAM,
+					IPPROTO_UDP, NULL, fwd_udp_ports[i],
+					OSMO_SOCK_F_BIND);
+		if (rc < 0) {
+			perror("sock_init");
+			exit(1);
+		}
+	}
+
+	while (1) {
+		rc = osmo_select_main(0);		
+		if (rc < 0) {
+			perror("select");
+			exit(1);
+		}
+	}
+	exit(0);
+}