From 1ec047eb4751e331bc61cff0e98f0db67db8b8dc Mon Sep 17 00:00:00 2001 From: Hannes Frederic Sowa Date: Thu, 27 Jun 2013 00:06:56 +0200 Subject: [PATCH] ipv6: introduce per-interface counter for dad-completed ipv6 addresses To reduce the number of unnecessary router solicitations, MLDv2 and IGMPv3 messages we need to track the number of valid (as in non-optimistic, no-dad-failed and non-tentative) link-local addresses. Therefore, this patch implements a valid_ll_addr_cnt in struct inet6_dev. We now only emit router solicitations if the first link-local address finishes duplicate address detection. The changes for MLDv2 and IGMPv3 are in a follow-up patch. While there, also simplify one if statement(one minor nit I made in one of my previous patches): if (!...) do(); else return; <> if (...) return; do(); Cc: Flavio Leitner Cc: YOSHIFUJI Hideaki Cc: David Stevens Suggested-by: David Stevens Signed-off-by: Hannes Frederic Sowa Acked-by: Flavio Leitner Signed-off-by: David S. Miller --- include/net/if_inet6.h | 1 + net/ipv6/addrconf.c | 39 +++++++++++++++++++++++++++++++-------- 2 files changed, 32 insertions(+), 8 deletions(-) diff --git a/include/net/if_inet6.h b/include/net/if_inet6.h index e4c5a2d..1628b8f 100644 --- a/include/net/if_inet6.h +++ b/include/net/if_inet6.h @@ -166,6 +166,7 @@ struct inet6_dev { struct net_device *dev; struct list_head addr_list; + int valid_ll_addr_cnt; struct ifmcaddr6 *mc_list; struct ifmcaddr6 *mc_tomb; diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 4e4cc1f..20d92ff 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -3277,6 +3277,7 @@ static void addrconf_dad_completed(struct inet6_ifaddr *ifp) { struct net_device *dev = ifp->idev->dev; struct in6_addr lladdr; + bool send_rs; addrconf_del_dad_timer(ifp); @@ -3290,20 +3291,25 @@ static void addrconf_dad_completed(struct inet6_ifaddr *ifp) router advertisements, start sending router solicitations. */ - if (ipv6_accept_ra(ifp->idev) && - ifp->idev->cnf.rtr_solicits > 0 && - (dev->flags&IFF_LOOPBACK) == 0 && - (ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL)) { + read_lock_bh(&ifp->idev->lock); + spin_lock(&ifp->lock); + send_rs = ipv6_accept_ra(ifp->idev) && + ifp->idev->cnf.rtr_solicits > 0 && + (dev->flags&IFF_LOOPBACK) == 0 && + ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL && + ifp->idev->valid_ll_addr_cnt == 1; + spin_unlock(&ifp->lock); + read_unlock_bh(&ifp->idev->lock); + + if (send_rs) { /* * If a host as already performed a random delay * [...] as part of DAD [...] there is no need * to delay again before sending the first RS */ - if (!ipv6_get_lladdr(dev, &lladdr, IFA_F_TENTATIVE)) - ndisc_send_rs(dev, &lladdr, - &in6addr_linklocal_allrouters); - else + if (ipv6_get_lladdr(dev, &lladdr, IFA_F_TENTATIVE)) return; + ndisc_send_rs(dev, &lladdr, &in6addr_linklocal_allrouters); write_lock_bh(&ifp->idev->lock); spin_lock(&ifp->lock); @@ -4576,6 +4582,19 @@ errout: rtnl_set_sk_err(net, RTNLGRP_IPV6_PREFIX, err); } +static void update_valid_ll_addr_cnt(struct inet6_ifaddr *ifp, int count) +{ + write_lock_bh(&ifp->idev->lock); + spin_lock(&ifp->lock); + if (((ifp->flags & (IFA_F_PERMANENT|IFA_F_TENTATIVE|IFA_F_OPTIMISTIC| + IFA_F_DADFAILED)) == IFA_F_PERMANENT) && + (ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL)) + ifp->idev->valid_ll_addr_cnt += count; + WARN_ON(ifp->idev->valid_ll_addr_cnt < 0); + spin_unlock(&ifp->lock); + write_unlock_bh(&ifp->idev->lock); +} + static void __ipv6_ifa_notify(int event, struct inet6_ifaddr *ifp) { struct net *net = dev_net(ifp->idev->dev); @@ -4584,6 +4603,8 @@ static void __ipv6_ifa_notify(int event, struct inet6_ifaddr *ifp) switch (event) { case RTM_NEWADDR: + update_valid_ll_addr_cnt(ifp, 1); + /* * If the address was optimistic * we inserted the route at the start of @@ -4599,6 +4620,8 @@ static void __ipv6_ifa_notify(int event, struct inet6_ifaddr *ifp) ifp->idev->dev, 0, 0); break; case RTM_DELADDR: + update_valid_ll_addr_cnt(ifp, -1); + if (ifp->idev->cnf.forwarding) addrconf_leave_anycast(ifp); addrconf_leave_solict(ifp->idev, &ifp->addr); -- 2.7.4