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: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2022-02-04 12:15:45 -08:00 committed by David S. Miller
parent 3115ff3c9d
commit 145c7a7938
5 changed files with 9 additions and 9 deletions

View File

@ -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;

View File

@ -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;

View File

@ -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;

View File

@ -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))) {

View File

@ -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,