[IPV6]: ROUTE: Add accept_ra_defrtr sysctl.

This controls whether we accept default router information
in RAs.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/ipv6.h

@@ -145,6 +145,7 @@ struct ipv6_devconf {
 	__s32		max_desync_factor;
 #endif
 	__s32		max_addresses;
+	__s32		accept_ra_defrtr;
 	void		*sysctl;
 };
 
@@ -167,6 +168,7 @@ enum {
 	DEVCONF_MAX_DESYNC_FACTOR,
 	DEVCONF_MAX_ADDRESSES,
 	DEVCONF_FORCE_MLD_VERSION,
+	DEVCONF_ACCEPT_RA_DEFRTR,
 	DEVCONF_MAX
 };
 

include/linux/sysctl.h

@@ -531,6 +531,7 @@ enum {
 	NET_IPV6_MAX_DESYNC_FACTOR=15,
 	NET_IPV6_MAX_ADDRESSES=16,
 	NET_IPV6_FORCE_MLD_VERSION=17,
+	NET_IPV6_ACCEPT_RA_DEFRTR=18,
 	__NET_IPV6_MAX
 };