Link state change notification of ethernet media to the routing socket.

o Extend the if_data structure with an ifi_link_state field and
  provide the corresponding defines for the valid states.

o The mii_linkchg() callback updates the ifi_link_state field
  and calls rt_ifmsg() to notify listeners on the routing socket
  in addition to the kqueue KNOTE.

o If vlans are configured on a physical interface notify and update
  all vlan pseudo devices as well with the vlan_link_state() callback.

No objections by:	sam, wpaul, ru, bms
Brucification by:	bde

4 files changed, 52 insertions, 4 deletions

diff --git a/sys/dev/mii/mii.c b/sys/dev/mii/mii.c
index 4771cc5..a22330b 100644
--- a/sys/dev/mii/mii.c
+++ b/sys/dev/mii/mii.c
@@ -58,6 +58,7 @@ __FBSDID("$FreeBSD$");
 
 #include <net/if.h>
 #include <net/if_media.h>
+#include <net/route.h>
 
 #include <dev/mii/mii.h>
 #include <dev/mii/miivar.h>
@@ -230,6 +231,8 @@ miibus_statchg(dev)
 	return;
 }
 
+void	(*vlan_link_state_p)(struct ifnet *, int);	/* XXX: private from if_vlan */
+
 static void
 miibus_linkchg(dev)
 	device_t dev;
@@ -237,7 +240,7 @@ miibus_linkchg(dev)
 	struct mii_data *mii;
 	struct ifnet *ifp;
 	device_t parent;
-	int link;
+	int link, link_state;
 
 	parent = device_get_parent(dev);
 	MIIBUS_LINKCHG(parent);
@@ -249,15 +252,26 @@ miibus_linkchg(dev)
 	ifp = device_get_softc(parent);
 	
 	if (mii->mii_media_status & IFM_AVALID) {
-		if (mii->mii_media_status & IFM_ACTIVE)
+		if (mii->mii_media_status & IFM_ACTIVE) {
 			link = NOTE_LINKUP;
-		else
+			link_state = LINK_STATE_UP;
+		} else {
 			link = NOTE_LINKDOWN;
+			link_state = LINK_STATE_DOWN;
+		}
 	} else {
 		link = NOTE_LINKINV;
+		link_state = LINK_STATE_UNKNOWN;
 	}
 
-	KNOTE(&ifp->if_klist, link);
+	/* Notify that the link state has changed. */
+	if (ifp->if_link_state != link_state) {
+		ifp->if_link_state = link_state;
+		rt_ifmsg(ifp);
+		KNOTE(&ifp->if_klist, link);
+		if (ifp->if_nvlans != 0)
+			(*vlan_link_state_p)(ifp, link);
+	}
 }
 
 static void
diff --git a/sys/net/if.h b/sys/net/if.h
index 625dfe0..2266fee 100644
--- a/sys/net/if.h
+++ b/sys/net/if.h
@@ -104,6 +104,7 @@ struct if_data {
 	u_char	ifi_physical;		/* e.g., AUI, Thinnet, 10base-T, etc */
 	u_char	ifi_addrlen;		/* media address length */
 	u_char	ifi_hdrlen;		/* media header length */
+	u_char	ifi_link_state;		/* current link state */
 	u_char	ifi_recvquota;		/* polling quota for receive intrs */
 	u_char	ifi_xmitquota;		/* polling quota for xmit intrs */
 	u_long	ifi_mtu;		/* maximum transmission unit */
@@ -155,6 +156,13 @@ struct if_data {
 	    IFF_POLLING)
 
 /*
+ * Values for if_link_state.
+ */
+#define	LINK_STATE_UNKNOWN	0	/* link invalid/unknown */
+#define	LINK_STATE_DOWN		1	/* link is down */
+#define	LINK_STATE_UP		2	/* link is up */
+
+/*
  * Some convenience macros used for setting ifi_baudrate.
  * XXX 1000 vs. 1024? --thorpej@netbsd.org
  */
diff --git a/sys/net/if_var.h b/sys/net/if_var.h
index 3d3cad5..541f214 100644
--- a/sys/net/if_var.h
+++ b/sys/net/if_var.h
@@ -197,6 +197,7 @@ typedef void if_init_f_t(void *);
 #define	if_addrlen	if_data.ifi_addrlen
 #define	if_hdrlen	if_data.ifi_hdrlen
 #define	if_metric	if_data.ifi_metric
+#define	if_link_state	if_data.ifi_link_state
 #define	if_baudrate	if_data.ifi_baudrate
 #define	if_hwassist	if_data.ifi_hwassist
 #define	if_ipackets	if_data.ifi_ipackets
diff --git a/sys/net/if_vlan.c b/sys/net/if_vlan.c
index 87eabb7..25ca790 100644
--- a/sys/net/if_vlan.c
+++ b/sys/net/if_vlan.c
@@ -125,6 +125,7 @@ static	int vlan_ioctl(struct ifnet *ifp, u_long cmd, caddr_t addr);
 static	int vlan_setmulti(struct ifnet *ifp);
 static	int vlan_unconfig(struct ifnet *ifp);
 static	int vlan_config(struct ifvlan *ifv, struct ifnet *p);
+static	void vlan_link_state(struct ifnet *ifp, int link);
 
 struct if_clone vlan_cloner = IF_CLONE_INITIALIZER(VLANNAME,
     vlan_clone_create, vlan_clone_destroy, 0, IF_MAXUNIT);
@@ -209,6 +210,9 @@ vlan_setmulti(struct ifnet *ifp)
  */
 extern	void (*vlan_input_p)(struct ifnet *, struct mbuf *);
 
+/* For MII eyes only... */
+extern	void (*vlan_link_state_p)(struct ifnet *, int);
+
 static int
 vlan_modevent(module_t mod, int type, void *data) 
 { 
@@ -218,11 +222,13 @@ vlan_modevent(module_t mod, int type, void *data)
 		LIST_INIT(&ifv_list);
 		VLAN_LOCK_INIT();
 		vlan_input_p = vlan_input;
+		vlan_link_state_p = vlan_link_state;
 		if_clone_attach(&vlan_cloner);
 		break; 
 	case MOD_UNLOAD: 
 		if_clone_detach(&vlan_cloner);
 		vlan_input_p = NULL;
+		vlan_link_state_p = NULL;
 		while (!LIST_EMPTY(&ifv_list))
 			vlan_clone_destroy(&LIST_FIRST(&ifv_list)->ifv_if);
 		VLAN_LOCK_DESTROY();
@@ -532,6 +538,7 @@ vlan_config(struct ifvlan *ifv, struct ifnet *p)
 	 */
 	ifv->ifv_if.if_flags = (p->if_flags &
 	    (IFF_BROADCAST | IFF_MULTICAST | IFF_SIMPLEX | IFF_POINTOPOINT));
+	ifv->ifv_if.if_link_state = p->if_link_state;
 
 	/*
 	 * If the parent interface can do hardware-assisted
@@ -622,6 +629,7 @@ vlan_unconfig(struct ifnet *ifp)
 	ifv->ifv_p = NULL;
 	ifv->ifv_if.if_mtu = ETHERMTU;		/* XXX why not 0? */
 	ifv->ifv_flags = 0;
+	ifv->ifv_if.if_link_state = LINK_STATE_UNKNOWN;
 
 	/* Clear our MAC address. */
 	ifa = ifaddr_byindex(ifv->ifv_if.if_index);
@@ -657,6 +665,23 @@ vlan_set_promisc(struct ifnet *ifp)
 	return (error);
 }
 
+/* Inform all vlans that their parent has changed link state */
+static void
+vlan_link_state(struct ifnet *ifp, int link)
+{
+	struct ifvlan *ifv;
+
+	VLAN_LOCK();
+	LIST_FOREACH(ifv, &ifv_list, ifv_list) {
+		if (ifv->ifv_p == ifp) {
+			ifv->ifv_if.if_link_state = ifv->ifv_p->if_link_state;
+			rt_ifmsg(&(ifv->ifv_if));
+			KNOTE(&ifp->if_klist, link);
+		}
+	}
+	VLAN_UNLOCK();
+}
+
 static int
 vlan_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
 {