diff options
| -rw-r--r-- | net/ipv4/ip_gre.c | 40 |
1 files changed, 23 insertions, 17 deletions
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c index 89ff9d5b..40f0439 100644 --- a/net/ipv4/ip_gre.c +++ b/net/ipv4/ip_gre.c @@ -156,8 +156,13 @@ struct ipgre_net { #define tunnels_r tunnels[2] #define tunnels_l tunnels[1] #define tunnels_wc tunnels[0] +/* + * Locking : hash tables are protected by RCU and a spinlock + */ +static DEFINE_SPINLOCK(ipgre_lock); -static DEFINE_RWLOCK(ipgre_lock); +#define for_each_ip_tunnel_rcu(start) \ + for (t = rcu_dereference(start); t; t = rcu_dereference(t->next)) /* Given src, dst and key, find appropriate for input tunnel. */ @@ -175,7 +180,7 @@ static struct ip_tunnel * ipgre_tunnel_lookup(struct net_device *dev, ARPHRD_ETHER : ARPHRD_IPGRE; int score, cand_score = 4; - for (t = ign->tunnels_r_l[h0^h1]; t; t = t->next) { + for_each_ip_tunnel_rcu(ign->tunnels_r_l[h0 ^ h1]) { if (local != t->parms.iph.saddr || remote != t->parms.iph.daddr || key != t->parms.i_key || @@ -200,7 +205,7 @@ static struct ip_tunnel * ipgre_tunnel_lookup(struct net_device *dev, } } - for (t = ign->tunnels_r[h0^h1]; t; t = t->next) { + for_each_ip_tunnel_rcu(ign->tunnels_r[h0 ^ h1]) { if (remote != t->parms.iph.daddr || key != t->parms.i_key || !(t->dev->flags & IFF_UP)) @@ -224,7 +229,7 @@ static struct ip_tunnel * ipgre_tunnel_lookup(struct net_device *dev, } } - for (t = ign->tunnels_l[h1]; t; t = t->next) { + for_each_ip_tunnel_rcu(ign->tunnels_l[h1]) { if ((local != t->parms.iph.saddr && (local != t->parms.iph.daddr || !ipv4_is_multicast(local))) || @@ -250,7 +255,7 @@ static struct ip_tunnel * ipgre_tunnel_lookup(struct net_device *dev, } } - for (t = ign->tunnels_wc[h1]; t; t = t->next) { + for_each_ip_tunnel_rcu(ign->tunnels_wc[h1]) { if (t->parms.i_key != key || !(t->dev->flags & IFF_UP)) continue; @@ -276,8 +281,9 @@ static struct ip_tunnel * ipgre_tunnel_lookup(struct net_device *dev, if (cand != NULL) return cand; - if (ign->fb_tunnel_dev->flags & IFF_UP) - return netdev_priv(ign->fb_tunnel_dev); + dev = ign->fb_tunnel_dev; + if (dev->flags & IFF_UP) + return netdev_priv(dev); return NULL; } @@ -311,10 +317,10 @@ static void ipgre_tunnel_link(struct ipgre_net *ign, struct ip_tunnel *t) { struct ip_tunnel **tp = ipgre_bucket(ign, t); + spin_lock_bh(&ipgre_lock); t->next = *tp; - write_lock_bh(&ipgre_lock); - *tp = t; - write_unlock_bh(&ipgre_lock); + rcu_assign_pointer(*tp, t); + spin_unlock_bh(&ipgre_lock); } static void ipgre_tunnel_unlink(struct ipgre_net *ign, struct ip_tunnel *t) @@ -323,9 +329,9 @@ static void ipgre_tunnel_unlink(struct ipgre_net *ign, struct ip_tunnel *t) for (tp = ipgre_bucket(ign, t); *tp; tp = &(*tp)->next) { if (t == *tp) { - write_lock_bh(&ipgre_lock); + spin_lock_bh(&ipgre_lock); *tp = t->next; - write_unlock_bh(&ipgre_lock); + spin_unlock_bh(&ipgre_lock); break; } } @@ -476,7 +482,7 @@ static void ipgre_err(struct sk_buff *skb, u32 info) break; } - read_lock(&ipgre_lock); + rcu_read_lock(); t = ipgre_tunnel_lookup(skb->dev, iph->daddr, iph->saddr, flags & GRE_KEY ? *(((__be32 *)p) + (grehlen / 4) - 1) : 0, @@ -494,7 +500,7 @@ static void ipgre_err(struct sk_buff *skb, u32 info) t->err_count = 1; t->err_time = jiffies; out: - read_unlock(&ipgre_lock); + rcu_read_unlock(); return; } @@ -573,7 +579,7 @@ static int ipgre_rcv(struct sk_buff *skb) gre_proto = *(__be16 *)(h + 2); - read_lock(&ipgre_lock); + rcu_read_lock(); if ((tunnel = ipgre_tunnel_lookup(skb->dev, iph->saddr, iph->daddr, key, gre_proto))) { @@ -647,13 +653,13 @@ static int ipgre_rcv(struct sk_buff *skb) ipgre_ecn_decapsulate(iph, skb); netif_rx(skb); - read_unlock(&ipgre_lock); + rcu_read_unlock(); return(0); } icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); drop: - read_unlock(&ipgre_lock); + rcu_read_unlock(); drop_nolock: kfree_skb(skb); return(0); |
