ipv6 addrconf: add accept_dad sysctl to control DAD operation.

- If 0, disable DAD.
- If 1, perform DAD (default).
- If >1, perform DAD and disable IPv6 operation if DAD for MAC-based
  link-local address has been failed (RFC4862 5.4.5).

We do not follow RFC4862 by default.  Refer to the netdev thread entitled
"Linux IPv6 DAD not full conform to RFC 4862 ?"
	http://www.spinics.net/lists/netdev/msg52027.html

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h
index d9d7f9b69eb4..391ad0843a46 100644
--- a/include/linux/ipv6.h
+++ b/include/linux/ipv6.h
@@ -164,6 +164,7 @@ struct ipv6_devconf {
         __s32           mc_forwarding;
 #endif
         __s32           disable_ipv6;
+        __s32           accept_dad;
         void            *sysctl;
 };
 
@@ -196,6 +197,7 @@ enum {
         DEVCONF_ACCEPT_SOURCE_ROUTE,
         DEVCONF_MC_FORWARDING,
         DEVCONF_DISABLE_IPV6,
+        DEVCONF_ACCEPT_DAD,
         DEVCONF_MAX
 };