From 1c7899c74e68cca6dbfddbed437d11001c0c3722 Mon Sep 17 00:00:00 2001
From: Gleb Smirnoff <glebius@FreeBSD.org>
Date: Sat, 8 Jan 2005 12:42:03 +0000
Subject: [PATCH] This change adds reliability for Ethernet trunks built with
 ng_one2many:

- Introduce another ng_ether(4) callback ng_ether_link_state_p, which
  is called from if_link_state_change(), every time link is changed.
- In ng_ether_link_state() send netgraph control message notifying
  of link state change to a node connected to "lower" hook.

Reviewed by:	sam
MFC after:	2 weeks
---
 sys/net/if.c            |  6 ++++++
 sys/netgraph/ng_ether.c | 31 +++++++++++++++++++++++++++++++
 2 files changed, 37 insertions(+)

diff --git a/sys/net/if.c b/sys/net/if.c
index 1dac78e3df55..55af93339c75 100644
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -79,6 +79,8 @@
 #include <netinet/if_ether.h>
 #endif
 
+void	(*ng_ether_link_state_p)(struct ifnet *ifp, int state);
+
 struct mbuf *(*tbr_dequeue_ptr)(struct ifaltq *, int) = NULL;
 
 static void	if_attachdomain(void *);
@@ -978,6 +980,10 @@ if_link_state_change(struct ifnet *ifp, int link_state)
 		KNOTE_UNLOCKED(&ifp->if_klist, link);
 		if (ifp->if_nvlans != 0)
 			(*vlan_link_state_p)(ifp, link);
+
+		if ((ifp->if_type == IFT_ETHER || ifp->if_type == IFT_L2VLAN) &&
+		    IFP2AC(ifp)->ac_netgraph != NULL)
+			(*ng_ether_link_state_p)(ifp, link_state);
 	}
 }
 
diff --git a/sys/netgraph/ng_ether.c b/sys/netgraph/ng_ether.c
index a2873ae380ad..a3932a19a660 100644
--- a/sys/netgraph/ng_ether.c
+++ b/sys/netgraph/ng_ether.c
@@ -89,6 +89,7 @@ extern	void	(*ng_ether_input_orphan_p)(struct ifnet *ifp, struct mbuf *m);
 extern	int	(*ng_ether_output_p)(struct ifnet *ifp, struct mbuf **mp);
 extern	void	(*ng_ether_attach_p)(struct ifnet *ifp);
 extern	void	(*ng_ether_detach_p)(struct ifnet *ifp);
+extern	void	(*ng_ether_link_state_p)(struct ifnet *ifp, int state);
 
 /* Functional hooks called from if_ethersubr.c */
 static void	ng_ether_input(struct ifnet *ifp, struct mbuf **mp);
@@ -96,6 +97,7 @@ static void	ng_ether_input_orphan(struct ifnet *ifp, struct mbuf *m);
 static int	ng_ether_output(struct ifnet *ifp, struct mbuf **mp);
 static void	ng_ether_attach(struct ifnet *ifp);
 static void	ng_ether_detach(struct ifnet *ifp); 
+static void	ng_ether_link_state(struct ifnet *ifp, int state); 
 
 /* Other functions */
 static int	ng_ether_rcv_lower(node_p node, struct mbuf *m);
@@ -312,6 +314,33 @@ ng_ether_detach(struct ifnet *ifp)
 	ng_rmnode_self(node);		/* remove all netgraph parts */
 }
 
+/*
+ * Notify graph about link event.
+ * if_link_state_change() has already checked that the state has changed.
+ */
+static void
+ng_ether_link_state(struct ifnet *ifp, int state)
+{
+	const node_p node = IFP2NG(ifp);
+	const priv_p priv = NG_NODE_PRIVATE(node);
+	struct ng_mesg *msg;
+	int cmd, dummy_error = 0;
+
+	if (priv->lower == NULL)
+                return;
+
+	if (state == LINK_STATE_UP)
+		cmd = NGM_LINK_IS_UP;
+	else if (state == LINK_STATE_DOWN)
+		cmd = NGM_LINK_IS_DOWN;
+	else
+		return;
+
+	NG_MKMESSAGE(msg, NGM_FLOW_COOKIE, cmd, 0, M_NOWAIT);
+	if (msg != NULL)
+		NG_SEND_MSG_HOOK(dummy_error, node, msg, priv->lower, 0);
+}
+
 /******************************************************************
 		    NETGRAPH NODE METHODS
 ******************************************************************/
@@ -645,6 +674,7 @@ ng_ether_mod_event(module_t mod, int event, void *data)
 		ng_ether_output_p = ng_ether_output;
 		ng_ether_input_p = ng_ether_input;
 		ng_ether_input_orphan_p = ng_ether_input_orphan;
+		ng_ether_link_state_p = ng_ether_link_state;
 
 		/* Create nodes for any already-existing Ethernet interfaces */
 		IFNET_RLOCK();
@@ -672,6 +702,7 @@ ng_ether_mod_event(module_t mod, int event, void *data)
 		ng_ether_output_p = NULL;
 		ng_ether_input_p = NULL;
 		ng_ether_input_orphan_p = NULL;
+		ng_ether_link_state_p = NULL;
 		break;
 
 	default: