3 files changed, 28 insertions, 10 deletions

diff --git a/sys/netgraph/netgraph.h b/sys/netgraph/netgraph.h
index 8981836cd2ed..99adc60d0da4 100644
--- a/sys/netgraph/netgraph.h
+++ b/sys/netgraph/netgraph.h
@@ -62,7 +62,7 @@
  * Change it for NETGRAPH_DEBUG version so we cannot mix debug and non debug
  * modules.
  */
-#define _NG_ABI_VERSION 7
+#define _NG_ABI_VERSION 8
 #ifdef	NETGRAPH_DEBUG /*----------------------------------------------*/
 #define NG_ABI_VERSION	(_NG_ABI_VERSION + 0x10000)
 #else	/* NETGRAPH_DEBUG */ /*----------------------------------------------*/
@@ -83,6 +83,7 @@ typedef struct ng_hook *hook_p;
 
 /* node method definitions */
 typedef	int	ng_constructor_t(node_p node);
+typedef	int	ng_close_t(node_p node);
 typedef	int	ng_shutdown_t(node_p node);
 typedef	int	ng_newhook_t(node_p node, hook_p hook, const char *name);
 typedef	hook_p	ng_findhook_t(node_p node, const char *name);
@@ -1052,6 +1053,7 @@ struct ng_type {
 	modeventhand_t	mod_event;	/* Module event handler (optional) */
 	ng_constructor_t *constructor;	/* Node constructor */
 	ng_rcvmsg_t	*rcvmsg;	/* control messages come here */
+	ng_close_t	*close;		/* warn about forthcoming shutdown */
 	ng_shutdown_t	*shutdown;	/* reset, and free resources */
 	ng_newhook_t	*newhook;	/* first notification of new hook */
 	ng_findhook_t	*findhook;	/* only if you have lots of hooks */
@@ -1112,6 +1114,7 @@ SYSCTL_DECL(_net_graph);
 int	ng_address_ID(node_p here, item_p item, ng_ID_t ID, ng_ID_t retaddr);
 int	ng_address_hook(node_p here, item_p item, hook_p hook, ng_ID_t retaddr);
 int	ng_address_path(node_p here, item_p item, char *address, ng_ID_t raddr);
+int	ng_bypass(hook_p hook1, hook_p hook2);
 meta_p	ng_copy_meta(meta_p meta);
 hook_p	ng_findhook(node_p node, const char *name);
 int	ng_make_node_common(struct ng_type *typep, node_p *nodep);
diff --git a/sys/netgraph/ng_base.c b/sys/netgraph/ng_base.c
index 878ec8853c3a..d3acc0173796 100644
--- a/sys/netgraph/ng_base.c
+++ b/sys/netgraph/ng_base.c
@@ -199,7 +199,6 @@ static int	ng_mkpeer(node_p node, const char *name,
 						const char *name2, char *type);
 
 /* imported , these used to be externally visible, some may go back */
-int	ng_bypass(hook_p hook1, hook_p hook2);
 void	ng_destroy_hook(hook_p hook);
 node_p	ng_name2noderef(node_p node, const char *name);
 int	ng_path2noderef(node_p here, const char *path,
@@ -694,6 +693,10 @@ ng_rmnode(node_p node, hook_p dummy1, void *dummy2, int dummy3)
 	 */
 	node->nd_flags |= NG_INVALID|NG_CLOSING;
 
+	/* If node has its pre-shutdown method, then call it first*/
+	if (node->nd_type && node->nd_type->close)
+		(*node->nd_type->close)(node);
+
 	/* Notify all remaining connected nodes to disconnect */
 	while ((hook = LIST_FIRST(&node->nd_hooks)) != NULL)
 		ng_destroy_hook(hook);
diff --git a/sys/netgraph/ng_tee.c b/sys/netgraph/ng_tee.c
index 1f6fb9a57386..d7d19d595de6 100644
--- a/sys/netgraph/ng_tee.c
+++ b/sys/netgraph/ng_tee.c
@@ -79,6 +79,7 @@ typedef struct privdata *sc_p;
 /* Netgraph methods */
 static ng_constructor_t	ngt_constructor;
 static ng_rcvmsg_t	ngt_rcvmsg;
+static ng_close_t	ngt_close;
 static ng_shutdown_t	ngt_shutdown;
 static ng_newhook_t	ngt_newhook;
 static ng_rcvdata_t	ngt_rcvdata;
@@ -132,6 +133,7 @@ static struct ng_type ng_tee_typestruct = {
 	.name =		NG_TEE_NODE_TYPE,
 	.constructor =	ngt_constructor,
 	.rcvmsg =	ngt_rcvmsg,
+	.close =	ngt_close,
 	.shutdown =	ngt_shutdown,
 	.newhook =	ngt_newhook,
 	.rcvdata =	ngt_rcvdata,
@@ -358,15 +360,25 @@ ngt_rcvdata(hook_p hook, item_p item)
 }
 
 /*
- * Shutdown processing
- *
- * This is tricky. If we have both a left and right hook, then we
- * probably want to extricate ourselves and leave the two peers
- * still linked to each other. Otherwise we should just shut down as
- * a normal node would.
+ * We are going to be shut down soon
  *
- * To keep the scope of info correct the routine to "extract" a node
- * from two links is in ng_base.c.
+ * If we have both a left and right hook, then we probably want to extricate
+ * ourselves and leave the two peers still linked to each other. Otherwise we
+ * should just shut down as a normal node would.
+ */
+static int
+ngt_close(node_p node)
+{
+	const sc_p privdata = NG_NODE_PRIVATE(node);
+
+	if (privdata->left.hook && privdata->right.hook)
+		ng_bypass(privdata->left.hook, privdata->right.hook);
+
+	return (0);
+}
+
+/*
+ * Shutdown processing
  */
 static int
 ngt_shutdown(node_p node)