Commit 145c7a79 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

ipv6: make mc_forwarding atomic 



This fixes minor data-races in ip6_mc_input() and
batadv_mcast_mla_rtr_flags_softif_get_ipv6()

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 3115ff3c

include/linux/ipv6.h

+1 −1
Original line number Diff line number Diff line
@@ -51,7 +51,7 @@ struct ipv6_devconf { 
	__s32		use_optimistic;

#endif

#ifdef CONFIG_IPV6_MROUTE

	__s32		mc_forwarding;

	atomic_t	mc_forwarding;

#endif

	__s32		disable_ipv6;

	__s32		drop_unicast_in_l2_multicast;

net/batman-adv/multicast.c

+1 −1
Original line number Diff line number Diff line
@@ -134,7 +134,7 @@ static u8 batadv_mcast_mla_rtr_flags_softif_get_ipv6(struct net_device *dev) 
{

	struct inet6_dev *in6_dev = __in6_dev_get(dev);



	if (in6_dev && in6_dev->cnf.mc_forwarding)

	if (in6_dev && atomic_read(&in6_dev->cnf.mc_forwarding))

		return BATADV_NO_FLAGS;

	else

		return BATADV_MCAST_WANT_NO_RTR6;

net/ipv6/addrconf.c

+2 −2
Original line number Diff line number Diff line
@@ -554,7 +554,7 @@ static int inet6_netconf_fill_devconf(struct sk_buff *skb, int ifindex, 
#ifdef CONFIG_IPV6_MROUTE

	if ((all || type == NETCONFA_MC_FORWARDING) &&

	    nla_put_s32(skb, NETCONFA_MC_FORWARDING,

			devconf->mc_forwarding) < 0)

			atomic_read(&devconf->mc_forwarding)) < 0)

		goto nla_put_failure;

#endif

	if ((all || type == NETCONFA_PROXY_NEIGH) &&
@@ -5533,7 +5533,7 @@ static inline void ipv6_store_devconf(struct ipv6_devconf *cnf, 
	array[DEVCONF_USE_OPTIMISTIC] = cnf->use_optimistic;

#endif

#ifdef CONFIG_IPV6_MROUTE

	array[DEVCONF_MC_FORWARDING] = cnf->mc_forwarding;

	array[DEVCONF_MC_FORWARDING] = atomic_read(&cnf->mc_forwarding);

#endif

	array[DEVCONF_DISABLE_IPV6] = cnf->disable_ipv6;

	array[DEVCONF_ACCEPT_DAD] = cnf->accept_dad;

net/ipv6/ip6_input.c

+1 −1
Original line number Diff line number Diff line
@@ -508,7 +508,7 @@ int ip6_mc_input(struct sk_buff *skb) 
	/*

	 *      IPv6 multicast router mode is now supported ;)

	 */

	if (dev_net(skb->dev)->ipv6.devconf_all->mc_forwarding &&

	if (atomic_read(&dev_net(skb->dev)->ipv6.devconf_all->mc_forwarding) &&

	    !(ipv6_addr_type(&hdr->daddr) &

	      (IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL)) &&

	    likely(!(IP6CB(skb)->flags & IP6SKB_FORWARDED))) {

net/ipv6/ip6mr.c

+4 −4
Original line number Diff line number Diff line
@@ -732,7 +732,7 @@ static int mif6_delete(struct mr_table *mrt, int vifi, int notify, 


	in6_dev = __in6_dev_get(dev);

	if (in6_dev) {

		in6_dev->cnf.mc_forwarding--;

		atomic_dec(&in6_dev->cnf.mc_forwarding);

		inet6_netconf_notify_devconf(dev_net(dev), RTM_NEWNETCONF,

					     NETCONFA_MC_FORWARDING,

					     dev->ifindex, &in6_dev->cnf);
@@ -900,7 +900,7 @@ static int mif6_add(struct net *net, struct mr_table *mrt, 


	in6_dev = __in6_dev_get(dev);

	if (in6_dev) {

		in6_dev->cnf.mc_forwarding++;

		atomic_inc(&in6_dev->cnf.mc_forwarding);

		inet6_netconf_notify_devconf(dev_net(dev), RTM_NEWNETCONF,

					     NETCONFA_MC_FORWARDING,

					     dev->ifindex, &in6_dev->cnf);
@@ -1551,7 +1551,7 @@ static int ip6mr_sk_init(struct mr_table *mrt, struct sock *sk) 
	} else {

		rcu_assign_pointer(mrt->mroute_sk, sk);

		sock_set_flag(sk, SOCK_RCU_FREE);

		net->ipv6.devconf_all->mc_forwarding++;

		atomic_inc(&net->ipv6.devconf_all->mc_forwarding);

	}

	write_unlock_bh(&mrt_lock);
@@ -1584,7 +1584,7 @@ int ip6mr_sk_done(struct sock *sk) 
			 * so the RCU grace period before sk freeing

			 * is guaranteed by sk_destruct()

			 */

			net->ipv6.devconf_all->mc_forwarding--;

			atomic_dec(&net->ipv6.devconf_all->mc_forwarding);

			write_unlock_bh(&mrt_lock);

			inet6_netconf_notify_devconf(net, RTM_NEWNETCONF,

						     NETCONFA_MC_FORWARDING,