Initial support for export + curses-visualization of measurements

This extends osmo_nitb to offer a UDP feed of real-time measurement
reports, which can be used by (a variety of) external tools for
visualization or other processing.

We also add a small ncurses based tool (meas_vis) which shows a
baragraph display of the last few mobile stations that were active,
indicating their uplink/downlink receive level and quality.

<WARNING>
This sends non-portable structures like gsm_meas_rep over UDP
and assumes the receiver has identical alignment and endianness!  Before
this feature is merged, it either needs to be converted to a unix domain
socket (but they don't do multicast, which would be nice) or the wire
format needs to change into something portable with defined alignment
and encoding
</WARNING>

1 files changed, 158 insertions, 0 deletions

diff --git a/openbsc/src/libmsc/meas_feed.c b/openbsc/src/libmsc/meas_feed.c
new file mode 100644
index 000000000..8466c76c0
--- /dev/null
+++ b/openbsc/src/libmsc/meas_feed.c
@@ -0,0 +1,158 @@
+/* UDP-Feed of measurement reports */
+
+#include <unistd.h>
+
+#include <osmocom/core/msgb.h>
+#include <osmocom/core/socket.h>
+#include <osmocom/core/write_queue.h>
+#include <osmocom/core/talloc.h>
+
+#include <osmocom/vty/command.h>
+#include <osmocom/vty/vty.h>
+
+#include <openbsc/meas_rep.h>
+#include <openbsc/signal.h>
+#include <openbsc/gsm_subscriber.h>
+#include <openbsc/meas_feed.h>
+#include <openbsc/vty.h>
+
+#include "meas_feed.h"
+
+struct meas_feed_state {
+	struct osmo_wqueue wqueue;
+	char scenario[31+1];
+	char *dst_host;
+	uint16_t dst_port;
+};
+
+
+static struct meas_feed_state g_mfs;
+
+static int process_meas_rep(struct gsm_meas_rep *mr)
+{
+	struct msgb *msg;
+	struct meas_feed_meas *mfm;
+	struct gsm_subscriber *subscr;
+
+	/* ignore measurements as long as we don't know who it is */
+	if (!mr->lchan || !mr->lchan->conn || !mr->lchan->conn->subscr)
+		return 0;
+
+	subscr = mr->lchan->conn->subscr;
+
+	msg = msgb_alloc(sizeof(struct meas_feed_meas), "Meas. Feed");
+	if (!msg)
+		return 0;
+
+	/* fill in the header */
+	mfm = (struct meas_feed_meas *) msgb_put(msg, sizeof(*mfm));
+	mfm->hdr.msg_type = MEAS_FEED_MEAS;
+	mfm->hdr.version = MEAS_FEED_VERSION;
+
+	/* fill in MEAS_FEED_MEAS specific header */
+	strncpy(mfm->imsi, subscr->imsi, sizeof(mfm->imsi)-1);
+	mfm->imsi[sizeof(mfm->imsi)-1] = '\0';
+	strncpy(mfm->name, subscr->name, sizeof(mfm->name)-1);
+	mfm->name[sizeof(mfm->name)-1] = '\0';
+	strncpy(mfm->scenario, g_mfs.scenario, sizeof(mfm->scenario));
+	mfm->scenario[sizeof(mfm->scenario)-1] = '\0';
+
+	/* copy the entire measurement report */
+	memcpy(&mfm->mr, mr, sizeof(mfm->mr));
+
+	/* and send it to the socket */
+	osmo_wqueue_enqueue(&g_mfs.wqueue, msg);
+
+	return 0;
+}
+
+static int meas_feed_sig_cb(unsigned int subsys, unsigned int signal,
+			    void *handler_data, void *signal_data)
+{
+	struct lchan_signal_data *sdata = signal_data;
+
+	if (subsys != SS_LCHAN)
+		return 0;
+
+	if (signal == S_LCHAN_MEAS_REP)
+		process_meas_rep(sdata->mr);
+
+	return 0;
+}
+
+static int feed_write_cb(struct osmo_fd *ofd, struct msgb *msg)
+{
+	return write(ofd->fd, msgb_data(msg), msgb_length(msg));
+}
+
+static int feed_read_cb(struct osmo_fd *ofd, struct msgb *msg)
+{
+	int rc;
+	char buf[256];
+
+	rc = read(ofd->fd, buf, sizeof(buf));
+	ofd->fd &= ~BSC_FD_READ;
+
+	return rc;
+}
+
+int meas_feed_cfg_set(const char *dst_host, uint16_t dst_port)
+{
+	int rc;
+	int already_initialized = 0;
+
+	if (g_mfs.wqueue.bfd.fd)
+		already_initialized = 1;
+
+
+	if (already_initialized &&
+	    !strcmp(dst_host, g_mfs.dst_host) &&
+	    dst_port == g_mfs.dst_port)
+		return 0;
+
+	if (!already_initialized) {
+		osmo_wqueue_init(&g_mfs.wqueue, 10);
+		g_mfs.wqueue.write_cb = feed_write_cb;
+		g_mfs.wqueue.read_cb = feed_read_cb;
+		osmo_signal_register_handler(SS_LCHAN, meas_feed_sig_cb, NULL);
+	}
+
+	if (already_initialized) {
+		osmo_wqueue_clear(&g_mfs.wqueue);
+		osmo_fd_unregister(&g_mfs.wqueue.bfd);
+		close(g_mfs.wqueue.bfd.fd);
+		/* don't set to zero, as that would mean 'not yet initialized' */
+		g_mfs.wqueue.bfd.fd = -1;
+	}
+	rc = osmo_sock_init_ofd(&g_mfs.wqueue.bfd, AF_UNSPEC, SOCK_DGRAM,
+				IPPROTO_UDP, dst_host, dst_port,
+				OSMO_SOCK_F_CONNECT);
+	if (rc < 0)
+		return rc;
+
+	g_mfs.wqueue.bfd.when &= ~BSC_FD_READ;
+
+	if (g_mfs.dst_host)
+		talloc_free(g_mfs.dst_host);
+	g_mfs.dst_host = talloc_strdup(NULL, dst_host);
+	g_mfs.dst_port = dst_port;
+
+	return 0;
+}
+
+void meas_feed_cfg_get(char **host, uint16_t *port)
+{
+	*port = g_mfs.dst_port;
+	*host = g_mfs.dst_host;
+}
+
+void meas_feed_scenario_set(const char *name)
+{
+	strncpy(g_mfs.scenario, name, sizeof(g_mfs.scenario)-1);
+	g_mfs.scenario[sizeof(g_mfs.scenario)-1] = '\0';
+}
+
+const char *meas_feed_scenario_get(void)
+{
+	return g_mfs.scenario;
+}