Now fix functionality of 'netstat -f netgraph' that hasn't worked

starting from netgraph import in 1999.

netstat(8) used pointer to node as node address, oops. That didn't
work, we need the node ID in brackets to successfully address a node.
We can't look into ng_node, due to inability to include netgraph/netgraph.h
in userland code. So let the node make a hint for a userland, storing
the node ID in its private data.

MFC after:	2 weeks

3 files changed, 7 insertions, 3 deletions

diff --git a/sys/netgraph/ng_socket.c b/sys/netgraph/ng_socket.c
index efee333..28e4f0e 100644
--- a/sys/netgraph/ng_socket.c
+++ b/sys/netgraph/ng_socket.c
@@ -552,6 +552,9 @@ ng_attach_cntl(struct socket *so)
 		return (error);
 	}
 
+	/* Store a hint for netstat(1). */
+	priv->node_id = priv->node->nd_ID;
+
 	/* Link the node and the private data. */
 	NG_NODE_SET_PRIVATE(priv->node, priv);
 	NG_NODE_REF(priv->node);
diff --git a/sys/netgraph/ng_socketvar.h b/sys/netgraph/ng_socketvar.h
index 3cf8103..c1e59dc 100644
--- a/sys/netgraph/ng_socketvar.h
+++ b/sys/netgraph/ng_socketvar.h
@@ -61,6 +61,7 @@ struct ngsock {
 	int    refs;
 	struct mtx	mtx;		/* mtx to wait on */
 	int		error;		/* place to store error */
+	ng_ID_t		node_id;	/* a hint for netstat(1) to find the node */
 };
 #define	NGS_FLAG_NOLINGER	1	/* close with last hook */
 
diff --git a/usr.bin/netstat/netgraph.c b/usr.bin/netstat/netgraph.c
index c4dd647..d510414 100644
--- a/usr.bin/netstat/netgraph.c
+++ b/usr.bin/netstat/netgraph.c
@@ -166,14 +166,14 @@ netgraphprotopr(u_long off, const char *name, int af1 __unused,
 		    name, sockb.so_rcv.sb_cc, sockb.so_snd.sb_cc);
 
 		/* Get ngsock structure */
-		if (ngpcb.sockdata == 0)	/* unconnected data socket */
+		if (ngpcb.sockdata == NULL)	/* unconnected data socket */
 			goto finish;
 		kread((u_long)ngpcb.sockdata, (char *)&info, sizeof(info));
 
 		/* Get info on associated node */
-		if (info.node == 0 || csock == -1)
+		if (info.node_id == 0 || csock == -1)
 			goto finish;
-		snprintf(path, sizeof(path), "[%lx]:", (u_long) info.node);
+		snprintf(path, sizeof(path), "[%x]:", info.node_id);
 		if (NgSendMsg(csock, path,
 		    NGM_GENERIC_COOKIE, NGM_NODEINFO, NULL, 0) < 0)
 			goto finish;