From eac55bf97094f6b64116426864cf4666ef7587bc Mon Sep 17 00:00:00 2001 From: Benoit Boissinot Date: Wed, 2 Apr 2008 00:01:35 -0700 Subject: IPv6: do not create temporary adresses with too short preferred lifetime From RFC341: A temporary address is created only if this calculated Preferred Lifetime is greater than REGEN_ADVANCE time units. In particular, an implementation must not create a temporary address with a zero Preferred Lifetime. Signed-off-by: Benoit Boissinot Signed-off-by: YOSHIFUJI Hideaki Signed-off-by: David S. Miller --- net/ipv6/addrconf.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index e11f10eceff..e7a1882db04 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -776,6 +776,7 @@ static int ipv6_create_tempaddr(struct inet6_ifaddr *ifp, struct inet6_ifaddr *i struct inet6_dev *idev = ifp->idev; struct in6_addr addr, *tmpaddr; unsigned long tmp_prefered_lft, tmp_valid_lft, tmp_cstamp, tmp_tstamp; + unsigned long regen_advance; int tmp_plen; int ret = 0; int max_addresses; @@ -836,8 +837,23 @@ retry: tmp_tstamp = ifp->tstamp; spin_unlock_bh(&ifp->lock); + regen_advance = idev->cnf.regen_max_retry * + idev->cnf.dad_transmits * + idev->nd_parms->retrans_time / HZ; write_unlock(&idev->lock); + /* A temporary address is created only if this calculated Preferred + * Lifetime is greater than REGEN_ADVANCE time units. In particular, + * an implementation must not create a temporary address with a zero + * Preferred Lifetime. + */ + if (tmp_prefered_lft <= regen_advance) { + in6_ifa_put(ifp); + in6_dev_put(idev); + ret = -1; + goto out; + } + addr_flags = IFA_F_TEMPORARY; /* set in addrconf_prefix_rcv() */ if (ifp->flags & IFA_F_OPTIMISTIC) -- cgit v1.2.3