VIRT-PHY: cause BTS to terminate in case of recv()/send() on udp socket returns 0

It is important that we reliably terminate the BTS in case any of the
VirtPHY multicast sockets dies for whatever reason.

Change-Id: I5ae3fdd7cc35fdf235550a3b8362020fdd287c13

3 files changed, 19 insertions, 5 deletions

diff --git a/src/osmo-bts-virtual/l1_if.c b/src/osmo-bts-virtual/l1_if.c
index 36b2748b..92121216 100644
--- a/src/osmo-bts-virtual/l1_if.c
+++ b/src/osmo-bts-virtual/l1_if.c
@@ -66,6 +66,13 @@ static struct phy_instance *phy_instance_by_arfcn(struct phy_link *plink, uint16
 static void virt_um_rcv_cb(struct virt_um_inst *vui, struct msgb *msg)
 {
 	struct phy_link *plink = (struct phy_link *)vui->priv;
+	struct phy_instance *pinst;
+	if (!msg) {
+		pinst = phy_instance_by_num(plink, 0);
+		bts_shutdown(pinst->trx->bts, "VirtPHY read socket died\n");
+		return;
+	}
+
 	struct gsmtap_hdr *gh = msgb_l1(msg);
 	uint32_t fn = ntohl(gh->frame_number);	/* frame number of the rcv msg */
 	uint16_t arfcn = ntohs(gh->arfcn); 	/* arfcn of the cell we currently camp on */
@@ -77,7 +84,6 @@ static void virt_um_rcv_cb(struct virt_um_inst *vui, struct msgb *msg)
 	uint8_t rsl_chantype;			/* rsl chan type (8.58, 9.3.1) */
 	uint8_t link_id;			/* rsl link id tells if this is an ssociated or dedicated link */
 	uint8_t chan_nr;			/* encoded rsl channel type, timeslot and mf subslot */
-	struct phy_instance *pinst;
 	struct osmo_phsap_prim l1sap;
 
 	memset(&l1sap, 0, sizeof(l1sap));
diff --git a/src/osmo-bts-virtual/scheduler_virtbts.c b/src/osmo-bts-virtual/scheduler_virtbts.c
index 9b52864e..1338ce59 100644
--- a/src/osmo-bts-virtual/scheduler_virtbts.c
+++ b/src/osmo-bts-virtual/scheduler_virtbts.c
@@ -36,6 +36,7 @@
 #include <osmo-bts/phy_link.h>
 #include <osmo-bts/logging.h>
 #include <osmo-bts/rsl.h>
+#include <osmo-bts/bts.h>
 #include <osmo-bts/l1sap.h>
 #include <osmo-bts/amr.h>
 #include <osmo-bts/scheduler.h>
@@ -93,9 +94,13 @@ static void tx_to_virt_um(struct l1sched_trx *l1t, uint8_t tn, uint32_t fn,
 	if (outmsg) {
 		struct phy_instance *pinst = trx_phy_instance(l1t->trx);
 		struct gsmtap_hdr *gh = (struct gsmtap_hdr *)msgb_data(outmsg);
+		int rc;
 
-		if (virt_um_write_msg(pinst->phy_link->u.virt.virt_um, outmsg) == -1)
+		rc = virt_um_write_msg(pinst->phy_link->u.virt.virt_um, outmsg);
+		if (rc < 0)
 			LOGP(DL1P, LOGL_ERROR, "%s GSMTAP msg could not send to virtual Um\n", gsmtap_hdr_stringify(gh));
+		else if (rc == 0)
+			bts_shutdown(l1t->trx->bts, "VirtPHY write socket died\n");
 		else
 			DEBUGP(DL1C, "%s Sending GSMTAP message to virtual Um\n", gsmtap_hdr_stringify(gh));
 	} else
diff --git a/src/osmo-bts-virtual/virtual_um.c b/src/osmo-bts-virtual/virtual_um.c
index e6b9615d..e8d42529 100644
--- a/src/osmo-bts-virtual/virtual_um.c
+++ b/src/osmo-bts-virtual/virtual_um.c
@@ -48,11 +48,12 @@ static int virt_um_fd_cb(struct osmo_fd *ofd, unsigned int what)
 			msg->l1h = msgb_data(msg);
 			/* call the l1 callback function for a received msg */
 			vui->recv_cb(vui, msg);
-		} else {
-			/* FIXME: this kind of error handling might be a bit harsh */
+		} else if (rc == 0) {
 			vui->recv_cb(vui, NULL);
 			osmo_fd_close(ofd);
-		}
+		} else
+			perror("Read from multicast socket");
+
 	}
 
 	return 0;
@@ -86,6 +87,8 @@ int virt_um_write_msg(struct virt_um_inst *vui, struct msgb *msg)
 
 	rc = mcast_bidir_sock_tx(vui->mcast_sock, msgb_data(msg),
 	                msgb_length(msg));
+	if (rc < 0)
+		perror("Writing to multicast socket");
 	msgb_free(msg);
 
 	return rc;