svn commit: r253878 - in stable/9: share/man/man4 sys/net

[Hiroki Sato]

Author: hrs
Date: Fri Aug  2 03:46:45 2013
New Revision: 253878
URL: http://svnweb.freebsd.org/changeset/base/253878

Log:
  MFC 253751 and 253843:
  
  - Relax the restriction on the member interfaces with LLAs.  Two or more
    LLAs on the member interfaces are actually harmless when the parent
    interface does not have a LLA.
  
  - Add net.link.bridge.allow_llz_overlap.  This is a knob to allow LLAs on
    a bridge and the member interfaces at the same time.  The default is 0.
  
  Approved by:	re (marius)

Modified:
  stable/9/share/man/man4/bridge.4
  stable/9/sys/net/if_bridge.c
Directory Properties:
  stable/9/share/man/man4/   (props changed)
  stable/9/sys/   (props changed)

Modified: stable/9/share/man/man4/bridge.4
==============================================================================
--- stable/9/share/man/man4/bridge.4	Fri Aug  2 00:20:04 2013	(r253877)
+++ stable/9/share/man/man4/bridge.4	Fri Aug  2 03:46:45 2013	(r253878)
@@ -35,7 +35,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd July 3, 2013
+.Dd July 27, 2013
 .Dt IF_BRIDGE 4
 .Os
 .Sh NAME
@@ -185,7 +185,7 @@ and applications use both of them.
 .Pp
 To prevent this situation,
 .Nm
-checks whether an link-local scoped IPv6 address is configured on
+checks whether a link-local scoped IPv6 address is configured on
 a member interface to be added and the
 .Nm
 interface.
@@ -194,13 +194,13 @@ When the
 interface has IPv6 addresses,
 IPv6 addresses on the member interface will be automatically removed
 before the interface is added.
-When both
-.Nm
-interface and the existing member interfaces do not have one,
-adding an interface with IPv6 addresses as a new member interface is allowed.
-These means only one interface in the link-local scope zone where the
-.Nm
-interface forms can have link-local scoped IPv6 addresses.
+.Pp
+This behavior can be disabled by setting
+.Xr sysctl 8
+variable
+.Va net.link.bridge.allow_llz_overlap
+to
+.Li 1 .
 .Pp
 Note that
 .Li ACCEPT_RTADV

Modified: stable/9/sys/net/if_bridge.c
==============================================================================
--- stable/9/sys/net/if_bridge.c	Fri Aug  2 00:20:04 2013	(r253877)
+++ stable/9/sys/net/if_bridge.c	Fri Aug  2 03:46:45 2013	(r253878)
@@ -384,6 +384,12 @@ SYSCTL_INT(_net_link_bridge, OID_AUTO, i
     &bridge_inherit_mac, 0,
     "Inherit MAC address from the first bridge member");
 
+static VNET_DEFINE(int, allow_llz_overlap) = 0;
+#define	V_allow_llz_overlap	VNET(allow_llz_overlap)
+SYSCTL_VNET_INT(_net_link_bridge, OID_AUTO, allow_llz_overlap, CTLFLAG_RW,
+    &VNET_NAME(allow_llz_overlap), 0, "Allow overlap of link-local scope "
+    "zones of a bridge interface and the member interfaces");
+
 struct bridge_control {
 	int	(*bc_func)(struct bridge_softc *, void *);
 	int	bc_argsize;
@@ -1064,7 +1070,8 @@ bridge_ioctl_add(struct bridge_softc *sc
 	 */
 
 	/* Check if the parent interface has a link-local scope addr. */
-	if (in6ifa_llaonifp(sc->sc_ifp) != NULL) {
+	if (V_allow_llz_overlap == 0 &&
+	    in6ifa_llaonifp(sc->sc_ifp) != NULL) {
 		/*
 		 * If any, remove all inet6 addresses from the member
 		 * interfaces.
@@ -1093,32 +1100,6 @@ bridge_ioctl_add(struct bridge_softc *sc
 			    "IPv6 address scope violation.\n",
 			    ifs->if_xname);
 		}
-	} else {
-		struct in6_ifaddr *ia6_m, *ia6_s;
-		/*
-		 * If not, check whether one of the existing member
-		 * interfaces have inet6 address.  If any, remove
-		 * inet6 addresses on the interface to be added.
-		 */
-		ia6_m = NULL;
-		BRIDGE_XLOCK(sc);
-		LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
-			ia6_m = in6ifa_llaonifp(bif->bif_ifp);
-			if (ia6_m != NULL)
-				break;
-		}
-		BRIDGE_XDROP(sc);
-		ia6_s = in6ifa_llaonifp(ifs);
-
-		if (ia6_m != NULL && ia6_s != NULL) {
-			BRIDGE_UNLOCK(sc);
-			in6_ifdetach(ifs);
-			BRIDGE_LOCK(sc);
-			if_printf(sc->sc_ifp, "IPv6 addresses on %s have "
-				  "been removed before adding it as a member "
-				  "to prevent IPv6 address scope violation.\n",
-				  ifs->if_xname);
-		}
 	}
 #endif
 	/* Allow the first Ethernet member to define the MTU */