hyperv/hn: Add network change support.

Currently the network change is simulated by link status changes.

MFC after:	1 week
Sponsored by:	Microsoft
Differential Revision:	https://reviews.freebsd.org/D8295

sys/dev/hyperv/netvsc/hv_net_vsc.h

@@ -207,7 +207,6 @@ struct hn_softc {
 	struct ifnet    *hn_ifp;
 	struct ifmedia	hn_media;
 	device_t        hn_dev;
-	int             hn_carrier;
 	int             hn_if_flags;
 	struct sx	hn_lock;
 	struct vmbus_channel *hn_prichan;
@@ -236,6 +235,9 @@ struct hn_softc {
 	struct taskqueue	*hn_mgmt_taskq;
 	struct taskqueue	*hn_mgmt_taskq0;
 	struct task		hn_link_task;
+	struct task		hn_netchg_init;
+	struct timeout_task	hn_netchg_status;
+	uint32_t		hn_link_flags;	/* HN_LINK_FLAG_ */
 
 	uint32_t		hn_caps;	/* HN_CAP_ */
 	uint32_t		hn_flags;	/* HN_FLAG_ */
@@ -271,6 +273,9 @@ struct hn_softc {
 #define HN_CAP_TSO6			0x0100
 #define HN_CAP_HASHVAL			0x0200
 
+#define HN_LINK_FLAG_LINKUP		0x0001
+#define HN_LINK_FLAG_NETCHG		0x0002
+
 /*
  * Externs
  */

sys/dev/hyperv/netvsc/hv_netvsc_drv_freebsd.c

@@ -335,6 +335,8 @@ static void hn_destroy_tx_data(struct hn_softc *);
 static void hn_start_taskfunc(void *, int);
 static void hn_start_txeof_taskfunc(void *, int);
 static void hn_link_taskfunc(void *, int);
+static void hn_netchg_init_taskfunc(void *, int);
+static void hn_netchg_status_taskfunc(void *, int);
 static void hn_suspend_mgmt_taskfunc(void *, int);
 static int hn_encap(struct hn_tx_ring *, struct hn_txdesc *, struct mbuf **);
 static int hn_create_rx_data(struct hn_softc *sc, int);
@@ -360,6 +362,7 @@ static void hn_rx_drain(struct vmbus_channel *);
 static void hn_tx_resume(struct hn_softc *, int);
 static void hn_tx_ring_qflush(struct hn_tx_ring *);
 static int netvsc_detach(device_t dev);
+static void hn_link_status(struct hn_softc *);
 
 static void hn_nvs_handle_notify(struct hn_softc *sc,
 		const struct vmbus_chanpkt_hdr *pkt);
@@ -482,7 +485,7 @@ hn_ifmedia_sts(struct ifnet *ifp, struct ifmediareq *ifmr)
 	ifmr->ifm_status = IFM_AVALID;
 	ifmr->ifm_active = IFM_ETHER;
 
-	if (!sc->hn_carrier) {
+	if ((sc->hn_link_flags & HN_LINK_FLAG_LINKUP) == 0) {
 		ifmr->ifm_active |= IFM_NONE;
 		return;
 	}
@@ -563,6 +566,9 @@ netvsc_attach(device_t dev)
 	taskqueue_start_threads(&sc->hn_mgmt_taskq0, 1, PI_NET, "%s mgmt",
 	    device_get_nameunit(dev));
 	TASK_INIT(&sc->hn_link_task, 0, hn_link_taskfunc, sc);
+	TASK_INIT(&sc->hn_netchg_init, 0, hn_netchg_init_taskfunc, sc);
+	TIMEOUT_TASK_INIT(sc->hn_mgmt_taskq0, &sc->hn_netchg_status, 0,
+	    hn_netchg_status_taskfunc, sc);
 
 	/*
 	 * Allocate ifnet and setup its name earlier, so that if_printf
@@ -808,10 +814,8 @@ netvsc_shutdown(device_t dev)
 }
 
 static void
-hn_link_taskfunc(void *xsc, int pending __unused)
+hn_link_status(struct hn_softc *sc)
 {
-	struct hn_softc *sc = xsc;
-	struct ifnet *ifp = sc->hn_ifp;
 	uint32_t link_status;
 	int error;
 
@@ -822,11 +826,51 @@ hn_link_taskfunc(void *xsc, int pending __unused)
 	}
 
 	if (link_status == NDIS_MEDIA_STATE_CONNECTED)
-		sc->hn_carrier = 1;
+		sc->hn_link_flags |= HN_LINK_FLAG_LINKUP;
 	else
-		sc->hn_carrier = 0;
+		sc->hn_link_flags &= ~HN_LINK_FLAG_LINKUP;
-	if_link_state_change(ifp,
+	if_link_state_change(sc->hn_ifp,
-	    sc->hn_carrier ? LINK_STATE_UP : LINK_STATE_DOWN);
+	    (sc->hn_link_flags & HN_LINK_FLAG_LINKUP) ?
+	    LINK_STATE_UP : LINK_STATE_DOWN);
+}
+
+static void
+hn_link_taskfunc(void *xsc, int pending __unused)
+{
+	struct hn_softc *sc = xsc;
+
+	if (sc->hn_link_flags & HN_LINK_FLAG_NETCHG)
+		return;
+	hn_link_status(sc);
+}
+
+static void
+hn_netchg_init_taskfunc(void *xsc, int pending __unused)
+{
+	struct hn_softc *sc = xsc;
+
+	/* Prevent any link status checks from running. */
+	sc->hn_link_flags |= HN_LINK_FLAG_NETCHG;
+
+	/*
+	 * Fake up a [link down --> link up] state change; 5 seconds
+	 * delay is used, which closely simulates miibus reaction
+	 * upon link down event.
+	 */
+	sc->hn_link_flags &= ~HN_LINK_FLAG_LINKUP;
+	if_link_state_change(sc->hn_ifp, LINK_STATE_DOWN);
+	taskqueue_enqueue_timeout(sc->hn_mgmt_taskq0,
+	    &sc->hn_netchg_status, 5 * hz);
+}
+
+static void
+hn_netchg_status_taskfunc(void *xsc, int pending __unused)
+{
+	struct hn_softc *sc = xsc;
+
+	/* Re-allow link status checks. */
+	sc->hn_link_flags &= ~HN_LINK_FLAG_NETCHG;
+	hn_link_status(sc);
 }
 
 void
@@ -837,6 +881,14 @@ hn_link_status_update(struct hn_softc *sc)
 		taskqueue_enqueue(sc->hn_mgmt_taskq, &sc->hn_link_task);
 }
 
+void
+hn_network_change(struct hn_softc *sc)
+{
+
+	if (sc->hn_mgmt_taskq != NULL)
+		taskqueue_enqueue(sc->hn_mgmt_taskq, &sc->hn_netchg_init);
+}
+
 static __inline int
 hn_txdesc_dmamap_load(struct hn_tx_ring *txr, struct hn_txdesc *txd,
     struct mbuf **m_head, bus_dma_segment_t *segs, int *nsegs)
@@ -3719,6 +3771,8 @@ hn_suspend_mgmt(struct hn_softc *sc)
 	/*
 	 * Make sure that all pending management tasks are completed.
 	 */
+	taskqueue_drain(sc->hn_mgmt_taskq0, &sc->hn_netchg_init);
+	taskqueue_drain_timeout(sc->hn_mgmt_taskq0, &sc->hn_netchg_status);
 	taskqueue_drain_all(sc->hn_mgmt_taskq0);
 }
 
@@ -3796,10 +3850,11 @@ hn_resume_mgmt(struct hn_softc *sc)
 {
 
 	/*
-	 * Kick off link status check.
+	 * Kick off network change detection, which will
+	 * do link status check too.
 	 */
 	sc->hn_mgmt_taskq = sc->hn_mgmt_taskq0;
-	hn_link_status_update(sc);
+	hn_network_change(sc);
 }
 
 static void

sys/dev/hyperv/netvsc/hv_rndis_filter.c

@@ -158,6 +158,7 @@ static void
 hv_rf_receive_indicate_status(struct hn_softc *sc, const void *data, int dlen)
 {
 	const struct rndis_status_msg *msg;
+	int ofs;
 
 	if (dlen < sizeof(*msg)) {
 		if_printf(sc->hn_ifp, "invalid RNDIS status\n");
@@ -176,8 +177,19 @@ hv_rf_receive_indicate_status(struct hn_softc *sc, const void *data, int dlen)
 		break;
 
 	case RNDIS_STATUS_NETWORK_CHANGE:
-		/* TODO */
+		ofs = RNDIS_STBUFOFFSET_ABS(msg->rm_stbufoffset);
-		if_printf(sc->hn_ifp, "network changed\n");
+		if (dlen < ofs + msg->rm_stbuflen ||
+		    msg->rm_stbuflen < sizeof(uint32_t)) {
+			if_printf(sc->hn_ifp, "network changed\n");
+		} else {
+			uint32_t change;
+
+			memcpy(&change, ((const uint8_t *)msg) + ofs,
+			    sizeof(change));
+			if_printf(sc->hn_ifp, "network changed, change %u\n",
+			    change);
+		}
+		hn_network_change(sc);
 		break;
 
 	default:

sys/dev/hyperv/netvsc/if_hnvar.h

@@ -139,6 +139,7 @@ int		hn_rxpkt(struct hn_rx_ring *rxr, const void *data, int dlen,
 		    const struct hn_recvinfo *info);
 void		hn_chan_rollup(struct hn_rx_ring *rxr, struct hn_tx_ring *txr);
 void		hn_link_status_update(struct hn_softc *sc);
+void		hn_network_change(struct hn_softc *sc);
 
 extern struct hn_send_ctx	hn_send_ctx_none;
 

sys/dev/hyperv/netvsc/ndis.h

@@ -32,6 +32,10 @@
 #define	NDIS_MEDIA_STATE_CONNECTED	0
 #define	NDIS_MEDIA_STATE_DISCONNECTED	1
 
+#define	NDIS_NETCHANGE_TYPE_POSSIBLE	1
+#define	NDIS_NETCHANGE_TYPE_DEFINITE	2
+#define	NDIS_NETCHANGE_TYPE_FROMMEDIA	3
+
 #define	NDIS_OFFLOAD_SET_NOCHG		0
 #define	NDIS_OFFLOAD_SET_ON		1
 #define	NDIS_OFFLOAD_SET_OFF		2

sys/net/rndis.h

@@ -320,6 +320,10 @@ struct rndis_status_msg {
 	/* rndis_diag_info */
 };
 
+/* stbuf offset from the beginning of rndis_status_msg. */
+#define	RNDIS_STBUFOFFSET_ABS(ofs)	\
+	((ofs) + __offsetof(struct rndis_status_msg, rm_status))
+
 /*
  * Immediately after rndis_status_msg.rm_stbufoffset, if a control
  * message is malformatted, or a packet message contains inappropriate