From 95f4a45de1a0f172b35451fc52283290adb21f6e Mon Sep 17 00:00:00 2001 From: Hannes Frederic Sowa Date: Mon, 13 Jan 2014 02:45:22 +0100 Subject: net: avoid reference counter overflows on fib_rules in multicast forwarding Bob Falken reported that after 4G packets, multicast forwarding stopped working. This was because of a rule reference counter overflow which freed the rule as soon as the overflow happend. This patch solves this by adding the FIB_LOOKUP_NOREF flag to fib_rules_lookup calls. This is safe even from non-rcu locked sections as in this case the flag only implies not taking a reference to the rule, which we don't need at all. Rules only hold references to the namespace, which are guaranteed to be available during the call of the non-rcu protected function reg_vif_xmit because of the interface reference which itself holds a reference to the net namespace. Fixes: f0ad0860d01e47 ("ipv4: ipmr: support multiple tables") Fixes: d1db275dd3f6e4 ("ipv6: ip6mr: support multiple tables") Reported-by: Bob Falken Cc: Patrick McHardy Cc: Thomas Graf Cc: Julian Anastasov Cc: Eric Dumazet Signed-off-by: Hannes Frederic Sowa Acked-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv6/ip6mr.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'net/ipv6') diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c index f365310bfcca..0eb4038a4d63 100644 --- a/net/ipv6/ip6mr.c +++ b/net/ipv6/ip6mr.c @@ -141,9 +141,12 @@ static struct mr6_table *ip6mr_get_table(struct net *net, u32 id) static int ip6mr_fib_lookup(struct net *net, struct flowi6 *flp6, struct mr6_table **mrt) { - struct ip6mr_result res; - struct fib_lookup_arg arg = { .result = &res, }; int err; + struct ip6mr_result res; + struct fib_lookup_arg arg = { + .result = &res, + .flags = FIB_LOOKUP_NOREF, + }; err = fib_rules_lookup(net->ipv6.mr6_rules_ops, flowi6_to_flowi(flp6), 0, &arg); -- cgit v1.2.3-58-ga151 From 11ffff752c6a5adc86f7dd397b2f75af8f917c51 Mon Sep 17 00:00:00 2001 From: Hannes Frederic Sowa Date: Thu, 16 Jan 2014 20:13:04 +0100 Subject: ipv6: simplify detection of first operational link-local address on interface In commit 1ec047eb4751e3 ("ipv6: introduce per-interface counter for dad-completed ipv6 addresses") I build the detection of the first operational link-local address much to complex. Additionally this code now has a race condition. Replace it with a much simpler variant, which just scans the address list when duplicate address detection completes, to check if this is the first valid link local address and send RS and MLD reports then. Fixes: 1ec047eb4751e3 ("ipv6: introduce per-interface counter for dad-completed ipv6 addresses") Reported-by: Jiri Pirko Cc: Flavio Leitner Signed-off-by: Hannes Frederic Sowa Acked-by: Flavio Leitner Acked-by: Jiri Pirko Signed-off-by: David S. Miller --- include/net/if_inet6.h | 1 - net/ipv6/addrconf.c | 38 +++++++++++++++++--------------------- 2 files changed, 17 insertions(+), 22 deletions(-) (limited to 'net/ipv6') diff --git a/include/net/if_inet6.h b/include/net/if_inet6.h index 76d54270f2e2..65bb13035598 100644 --- a/include/net/if_inet6.h +++ b/include/net/if_inet6.h @@ -165,7 +165,6 @@ 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 abe46a4228ce..4b6b720971b9 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -3189,6 +3189,22 @@ out: in6_ifa_put(ifp); } +/* ifp->idev must be at least read locked */ +static bool ipv6_lonely_lladdr(struct inet6_ifaddr *ifp) +{ + struct inet6_ifaddr *ifpiter; + struct inet6_dev *idev = ifp->idev; + + list_for_each_entry(ifpiter, &idev->addr_list, if_list) { + if (ifp != ifpiter && ifpiter->scope == IFA_LINK && + (ifpiter->flags & (IFA_F_PERMANENT|IFA_F_TENTATIVE| + IFA_F_OPTIMISTIC|IFA_F_DADFAILED)) == + IFA_F_PERMANENT) + return false; + } + return true; +} + static void addrconf_dad_completed(struct inet6_ifaddr *ifp) { struct net_device *dev = ifp->idev->dev; @@ -3208,14 +3224,11 @@ static void addrconf_dad_completed(struct inet6_ifaddr *ifp) */ read_lock_bh(&ifp->idev->lock); - spin_lock(&ifp->lock); - send_mld = ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL && - ifp->idev->valid_ll_addr_cnt == 1; + send_mld = ifp->scope == IFA_LINK && ipv6_lonely_lladdr(ifp); send_rs = send_mld && ipv6_accept_ra(ifp->idev) && ifp->idev->cnf.rtr_solicits > 0 && (dev->flags&IFF_LOOPBACK) == 0; - spin_unlock(&ifp->lock); read_unlock_bh(&ifp->idev->lock); /* While dad is in progress mld report's source address is in6_addrany. @@ -4512,19 +4525,6 @@ 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); @@ -4533,8 +4533,6 @@ 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 @@ -4550,8 +4548,6 @@ 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); -- cgit v1.2.3-58-ga151