* [PATCH net-next 1/2] ipv6: make mc_forwarding atomic
2022-02-04 20:15 [PATCH net-next 0/2] ipv6: mc_forwarding changes Eric Dumazet
@ 2022-02-04 20:15 ` Eric Dumazet
2022-02-04 20:15 ` [PATCH net-next 2/2] ip6mr: ip6mr_sk_done() can exit early in common cases Eric Dumazet
2022-02-05 15:40 ` [PATCH net-next 0/2] ipv6: mc_forwarding changes patchwork-bot+netdevbpf
2 siblings, 0 replies; 4+ messages in thread
From: Eric Dumazet @ 2022-02-04 20:15 UTC (permalink / raw)
To: David S . Miller, Jakub Kicinski
Cc: netdev, David Ahern, Eric Dumazet, Eric Dumazet
From: Eric Dumazet <edumazet@google•com>
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>
---
include/linux/ipv6.h | 2 +-
net/batman-adv/multicast.c | 2 +-
net/ipv6/addrconf.c | 4 ++--
net/ipv6/ip6_input.c | 2 +-
net/ipv6/ip6mr.c | 8 ++++----
5 files changed, 9 insertions(+), 9 deletions(-)
diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h
index 1e0f8a31f3de175659dca9ecee9f97d8b01e2b68..16870f86c74d3d1f5dfb7edac1e7db85f1ef6755 100644
--- a/include/linux/ipv6.h
+++ b/include/linux/ipv6.h
@@ -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;
diff --git a/net/batman-adv/multicast.c b/net/batman-adv/multicast.c
index f4004cf0ff6fbf8f586d68f33ff63d3192bc5ca9..9f311fddfaf9aa6d35cd1039699203b7aaccbfdf 100644
--- a/net/batman-adv/multicast.c
+++ b/net/batman-adv/multicast.c
@@ -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;
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index f927c199a93c3ed1124be02eb32a20900980f337..ff1b2484b8ed8638e4d37eb21c67de4e5ac43dae 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -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;
diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c
index 80256717868e69766acb3b590680f34a4ed1c0e9..d4b1e2c5aa76dd09efc6c48bf7e281447fdf10c1 100644
--- a/net/ipv6/ip6_input.c
+++ b/net/ipv6/ip6_input.c
@@ -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))) {
diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c
index 7cf73e60e619ba92ea1eccc90c181ba7150225dd..541cd08871293eb5702e47e0645ea16394621e97 100644
--- a/net/ipv6/ip6mr.c
+++ b/net/ipv6/ip6mr.c
@@ -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,
--
2.35.0.263.gb82422642f-goog
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH net-next 2/2] ip6mr: ip6mr_sk_done() can exit early in common cases
2022-02-04 20:15 [PATCH net-next 0/2] ipv6: mc_forwarding changes Eric Dumazet
2022-02-04 20:15 ` [PATCH net-next 1/2] ipv6: make mc_forwarding atomic Eric Dumazet
@ 2022-02-04 20:15 ` Eric Dumazet
2022-02-05 15:40 ` [PATCH net-next 0/2] ipv6: mc_forwarding changes patchwork-bot+netdevbpf
2 siblings, 0 replies; 4+ messages in thread
From: Eric Dumazet @ 2022-02-04 20:15 UTC (permalink / raw)
To: David S . Miller, Jakub Kicinski
Cc: netdev, David Ahern, Eric Dumazet, Eric Dumazet
From: Eric Dumazet <edumazet@google•com>
In many cases, ip6mr_sk_done() is called while no ipmr socket
has been registered.
This removes 4 rtnl acquisitions per netns dismantle,
with following callers:
igmp6_net_exit(), tcpv6_net_exit(), ndisc_net_exit()
Signed-off-by: Eric Dumazet <edumazet@google•com>
---
net/ipv6/ip6mr.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c
index 541cd08871293eb5702e47e0645ea16394621e97..8e483e14b5709b1b8a6e9dfd6616a5bde5c273ee 100644
--- a/net/ipv6/ip6mr.c
+++ b/net/ipv6/ip6mr.c
@@ -1575,6 +1575,9 @@ int ip6mr_sk_done(struct sock *sk)
inet_sk(sk)->inet_num != IPPROTO_ICMPV6)
return err;
+ if (!atomic_read(&net->ipv6.devconf_all->mc_forwarding))
+ return err;
+
rtnl_lock();
ip6mr_for_each_table(mrt, net) {
if (sk == rtnl_dereference(mrt->mroute_sk)) {
--
2.35.0.263.gb82422642f-goog
^ permalink raw reply related [flat|nested] 4+ messages in thread