Factorize the bits to check if a L2 route is connected, wether it is

attached to a carp(4) or bridge(4) member, to not dereference rt_ifp
directly.

ok visa@

2 files changed, 34 insertions, 2 deletions

diff --git a/sys/net/if.c b/sys/net/if.c
index b4662375189..2f4d0399f6f 100644
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if.c,v 1.406 2015/11/13 10:18:04 mpi Exp $	*/
+/*	$OpenBSD: if.c,v 1.407 2015/11/18 13:58:02 mpi Exp $	*/
 /*	$NetBSD: if.c,v 1.35 1996/05/07 05:26:04 thorpej Exp $	*/
 
 /*
@@ -945,6 +945,36 @@ if_detach(struct ifnet *ifp)
 }
 
 /*
+ * Returns true if ``ifp0'' is connected to the interface with index ``ifidx''.
+ */
+int
+if_isconnected(const struct ifnet *ifp0, unsigned int ifidx)
+{
+	struct ifnet *ifp;
+	int connected = 0;
+
+	ifp = if_get(ifidx);
+	if (ifp == NULL)
+		return (0);
+
+	if (ifp0->if_index == ifp->if_index)
+		connected = 1;
+
+#if NBRIDGE > 0
+	if (SAME_BRIDGE(ifp0->if_bridgeport, ifp->if_bridgeport))
+		connected = 1;
+#endif
+#if NCARP > 0
+	if ((ifp0->if_type == IFT_CARP && ifp0->if_carpdev == ifp) ||
+	    (ifp->if_type == IFT_CARP && ifp->if_carpdev == ifp0))
+	    	connected = 1;
+#endif
+
+	if_put(ifp);
+	return (connected);
+}
+
+/*
  * Create a clone network interface.
  */
 int
diff --git a/sys/net/if_var.h b/sys/net/if_var.h
index b2e70e50a1b..abc6af69dbc 100644
--- a/sys/net/if_var.h
+++ b/sys/net/if_var.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_var.h,v 1.52 2015/11/11 10:23:23 mpi Exp $	*/
+/*	$OpenBSD: if_var.h,v 1.53 2015/11/18 13:58:02 mpi Exp $	*/
 /*	$NetBSD: if.h,v 1.23 1996/05/07 02:40:27 thorpej Exp $	*/
 
 /*
@@ -426,6 +426,8 @@ struct	ifaddr *ifa_ifwithnet(struct sockaddr *, u_int);
 struct	ifaddr *ifaof_ifpforaddr(struct sockaddr *, struct ifnet *);
 void	ifafree(struct ifaddr *);
 
+int	if_isconnected(const struct ifnet *, unsigned int);
+
 void	if_clone_attach(struct if_clone *);
 void	if_clone_detach(struct if_clone *);