ipv6: do retries on stable privacy addresses

If a DAD conflict is detected, we want to retry privacy stable address
generation up to idgen_retries (= 3) times with a delay of idgen_delay
(= 1 second). Add the logic to addrconf_dad_failure.

By design, we don't clean up dad failed permanent addresses.

Cc: Erik Kline <ek@google.com>
Cc: Fernando Gont <fgont@si6networks.com>
Cc: Lorenzo Colitti <lorenzo@google.com>
Cc: YOSHIFUJI Hideaki/吉藤英明 <hideaki.yoshifuji@miraclelinux.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Hannes Frederic Sowa 2015-03-23 23:36:04 +01:00 committed by David S. Miller
parent 8e8e676d0b
commit 5f40ef77ad
2 changed files with 55 additions and 3 deletions

View File

@ -52,6 +52,7 @@ struct inet6_ifaddr {
__u32 flags;
__u8 dad_probes;
__u8 stable_privacy_retry;
__u16 scope;

View File

@ -1710,6 +1710,7 @@ static int addrconf_dad_end(struct inet6_ifaddr *ifp)
void addrconf_dad_failure(struct inet6_ifaddr *ifp)
{
struct in6_addr addr;
struct inet6_dev *idev = ifp->idev;
if (addrconf_dad_end(ifp)) {
@ -1720,9 +1721,59 @@ void addrconf_dad_failure(struct inet6_ifaddr *ifp)
net_info_ratelimited("%s: IPv6 duplicate address %pI6c detected!\n",
ifp->idev->dev->name, &ifp->addr);
if (idev->cnf.accept_dad > 1 && !idev->cnf.disable_ipv6) {
struct in6_addr addr;
spin_lock_bh(&ifp->lock);
if (ifp->flags & IFA_F_STABLE_PRIVACY) {
int scope = ifp->scope;
u32 flags = ifp->flags;
struct in6_addr new_addr;
struct inet6_ifaddr *ifp2;
u32 valid_lft, preferred_lft;
int pfxlen = ifp->prefix_len;
const unsigned int idgen_retries = 3;
const unsigned int idgen_delay = 1 * HZ;
int retries = ifp->stable_privacy_retry + 1;
if (retries > idgen_retries) {
net_info_ratelimited("%s: privacy stable address generation failed because of DAD conflicts!\n",
ifp->idev->dev->name);
goto errdad;
}
new_addr = ifp->addr;
if (ipv6_generate_stable_address(&new_addr, retries,
idev))
goto errdad;
valid_lft = ifp->valid_lft;
preferred_lft = ifp->prefered_lft;
spin_unlock_bh(&ifp->lock);
if (idev->cnf.max_addresses &&
ipv6_count_addresses(idev) >=
idev->cnf.max_addresses)
goto lock_errdad;
net_info_ratelimited("%s: generating new stable privacy address because of DAD conflict\n",
ifp->idev->dev->name);
ifp2 = ipv6_add_addr(idev, &new_addr, NULL, pfxlen,
scope, flags, valid_lft,
preferred_lft);
if (IS_ERR(ifp2))
goto lock_errdad;
spin_lock_bh(&ifp2->lock);
ifp2->stable_privacy_retry = retries;
ifp2->state = INET6_IFADDR_STATE_PREDAD;
spin_unlock_bh(&ifp2->lock);
addrconf_mod_dad_work(ifp2, idgen_delay);
in6_ifa_put(ifp2);
lock_errdad:
spin_lock_bh(&ifp->lock);
} else if (idev->cnf.accept_dad > 1 && !idev->cnf.disable_ipv6) {
addr.s6_addr32[0] = htonl(0xfe800000);
addr.s6_addr32[1] = 0;
@ -1736,7 +1787,7 @@ void addrconf_dad_failure(struct inet6_ifaddr *ifp)
}
}
spin_lock_bh(&ifp->lock);
errdad:
/* transition from _POSTDAD to _ERRDAD */
ifp->state = INET6_IFADDR_STATE_ERRDAD;
spin_unlock_bh(&ifp->lock);