From 66eb9f86e50547ec2a8ff7a75997066a74ef584b Mon Sep 17 00:00:00 2001 From: Mahesh Bandewar Date: Fri, 12 May 2017 17:03:39 -0700 Subject: [PATCH] ipv6: avoid dad-failures for addresses with NODAD Every address gets added with TENTATIVE flag even for the addresses with IFA_F_NODAD flag and dad-work is scheduled for them. During this DAD process we realize it's an address with NODAD and complete the process without sending any probe. However the TENTATIVE flags stays on the address for sometime enough to cause misinterpretation when we receive a NS. While processing NS, if the address has TENTATIVE flag, we mark it DADFAILED and endup with an address that was originally configured as NODAD with DADFAILED. We can't avoid scheduling dad_work for addresses with NODAD but we can avoid adding TENTATIVE flag to avoid this racy situation. Signed-off-by: Mahesh Bandewar Acked-by: David Ahern Signed-off-by: David S. Miller --- net/ipv6/addrconf.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 8d297a7..6a4fb1e 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -1022,7 +1022,10 @@ ipv6_add_addr(struct inet6_dev *idev, const struct in6_addr *addr, INIT_HLIST_NODE(&ifa->addr_lst); ifa->scope = scope; ifa->prefix_len = pfxlen; - ifa->flags = flags | IFA_F_TENTATIVE; + ifa->flags = flags; + /* No need to add the TENTATIVE flag for addresses with NODAD */ + if (!(flags & IFA_F_NODAD)) + ifa->flags |= IFA_F_TENTATIVE; ifa->valid_lft = valid_lft; ifa->prefered_lft = prefered_lft; ifa->cstamp = ifa->tstamp = jiffies; -- 2.7.4