diff options
| -rw-r--r-- | net/ipv6/sit.c | 45 |
1 files changed, 27 insertions, 18 deletions
diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c index 8cdcc2ad048..b6b16264b30 100644 --- a/net/ipv6/sit.c +++ b/net/ipv6/sit.c @@ -77,8 +77,17 @@ struct sit_net { struct net_device *fb_tunnel_dev; }; -static DEFINE_RWLOCK(ipip6_lock); +/* + * Locking : hash tables are protected by RCU and a spinlock + */ +static DEFINE_SPINLOCK(ipip6_lock); + +#define for_each_ip_tunnel_rcu(start) \ + for (t = rcu_dereference(start); t; t = rcu_dereference(t->next)) +/* + * Must be invoked with rcu_read_lock + */ static struct ip_tunnel * ipip6_tunnel_lookup(struct net *net, struct net_device *dev, __be32 remote, __be32 local) { @@ -87,26 +96,26 @@ static struct ip_tunnel * ipip6_tunnel_lookup(struct net *net, struct ip_tunnel *t; struct sit_net *sitn = net_generic(net, sit_net_id); - for (t = sitn->tunnels_r_l[h0^h1]; t; t = t->next) { + for_each_ip_tunnel_rcu(sitn->tunnels_r_l[h0 ^ h1]) { if (local == t->parms.iph.saddr && remote == t->parms.iph.daddr && (!dev || !t->parms.link || dev->iflink == t->parms.link) && (t->dev->flags & IFF_UP)) return t; } - for (t = sitn->tunnels_r[h0]; t; t = t->next) { + for_each_ip_tunnel_rcu(sitn->tunnels_r[h0]) { if (remote == t->parms.iph.daddr && (!dev || !t->parms.link || dev->iflink == t->parms.link) && (t->dev->flags & IFF_UP)) return t; } - for (t = sitn->tunnels_l[h1]; t; t = t->next) { + for_each_ip_tunnel_rcu(sitn->tunnels_l[h1]) { if (local == t->parms.iph.saddr && (!dev || !t->parms.link || dev->iflink == t->parms.link) && (t->dev->flags & IFF_UP)) return t; } - t = sitn->tunnels_wc[0]; + t = rcu_dereference(sitn->tunnels_wc[0]); if ((t != NULL) && (t->dev->flags & IFF_UP)) return t; return NULL; @@ -143,9 +152,9 @@ static void ipip6_tunnel_unlink(struct sit_net *sitn, struct ip_tunnel *t) for (tp = ipip6_bucket(sitn, t); *tp; tp = &(*tp)->next) { if (t == *tp) { - write_lock_bh(&ipip6_lock); + spin_lock_bh(&ipip6_lock); *tp = t->next; - write_unlock_bh(&ipip6_lock); + spin_unlock_bh(&ipip6_lock); break; } } @@ -155,10 +164,10 @@ static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t) { struct ip_tunnel **tp = ipip6_bucket(sitn, t); + spin_lock_bh(&ipip6_lock); t->next = *tp; - write_lock_bh(&ipip6_lock); - *tp = t; - write_unlock_bh(&ipip6_lock); + rcu_assign_pointer(*tp, t); + spin_unlock_bh(&ipip6_lock); } static void ipip6_tunnel_clone_6rd(struct net_device *dev, struct sit_net *sitn) @@ -447,9 +456,9 @@ static void ipip6_tunnel_uninit(struct net_device *dev) struct sit_net *sitn = net_generic(net, sit_net_id); if (dev == sitn->fb_tunnel_dev) { - write_lock_bh(&ipip6_lock); + spin_lock_bh(&ipip6_lock); sitn->tunnels_wc[0] = NULL; - write_unlock_bh(&ipip6_lock); + spin_unlock_bh(&ipip6_lock); dev_put(dev); } else { ipip6_tunnel_unlink(sitn, netdev_priv(dev)); @@ -502,7 +511,7 @@ static int ipip6_err(struct sk_buff *skb, u32 info) err = -ENOENT; - read_lock(&ipip6_lock); + rcu_read_lock(); t = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev, iph->daddr, @@ -520,7 +529,7 @@ static int ipip6_err(struct sk_buff *skb, u32 info) t->err_count = 1; t->err_time = jiffies; out: - read_unlock(&ipip6_lock); + rcu_read_unlock(); return err; } @@ -540,7 +549,7 @@ static int ipip6_rcv(struct sk_buff *skb) iph = ip_hdr(skb); - read_lock(&ipip6_lock); + rcu_read_lock(); tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev, iph->saddr, iph->daddr); if (tunnel != NULL) { @@ -554,7 +563,7 @@ static int ipip6_rcv(struct sk_buff *skb) if ((tunnel->dev->priv_flags & IFF_ISATAP) && !isatap_chksrc(skb, iph, tunnel)) { tunnel->dev->stats.rx_errors++; - read_unlock(&ipip6_lock); + rcu_read_unlock(); kfree_skb(skb); return 0; } @@ -565,12 +574,12 @@ static int ipip6_rcv(struct sk_buff *skb) nf_reset(skb); ipip6_ecn_decapsulate(iph, skb); netif_rx(skb); - read_unlock(&ipip6_lock); + rcu_read_unlock(); return 0; } icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); - read_unlock(&ipip6_lock); + rcu_read_unlock(); out: kfree_skb(skb); return 0; |