Commit eac55bf9 authored by Benoit Boissinot's avatar Benoit Boissinot Committed by David S. Miller
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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: default avatarBenoit Boissinot <benoit.boissinot@ens-lyon.org>
Signed-off-by: default avatarYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c6fbfac2
......@@ -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)
......
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