From 5f40ef77adb237954d615a76621df1b80a329b31 Mon Sep 17 00:00:00 2001 From: Hannes Frederic Sowa Date: Mon, 23 Mar 2015 23:36:04 +0100 Subject: [PATCH] ipv6: do retries on stable privacy addresses MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Cc: Fernando Gont Cc: Lorenzo Colitti Cc: YOSHIFUJI Hideaki/吉藤英明 Signed-off-by: Hannes Frederic Sowa Signed-off-by: David S. Miller --- include/net/if_inet6.h | 1 + net/ipv6/addrconf.c | 57 +++++++++++++++++++++++++++++++++++++++--- 2 files changed, 55 insertions(+), 3 deletions(-) diff --git a/include/net/if_inet6.h b/include/net/if_inet6.h index d89397a22903..1c8b6820b694 100644 --- a/include/net/if_inet6.h +++ b/include/net/if_inet6.h @@ -52,6 +52,7 @@ struct inet6_ifaddr { __u32 flags; __u8 dad_probes; + __u8 stable_privacy_retry; __u16 scope; diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 1cc5320e510f..9b51fdb42ba9 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -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); -- 2.39.5