netns: net_identifiers should be read_mostly
[deliverable/linux.git] / net / ipv4 / ip_gre.c
index 41ada9904d3125c32b063b3dad025cc4898c2c60..c5f6af5d0f3401d4cc6a156bf3b1269b8e9319b0 100644 (file)
@@ -125,7 +125,7 @@ static int ipgre_tunnel_bind_dev(struct net_device *dev);
 
 #define HASH_SIZE  16
 
-static int ipgre_net_id;
+static int ipgre_net_id __read_mostly;
 struct ipgre_net {
        struct ip_tunnel *tunnels[4][HASH_SIZE];
 
@@ -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);
@@ -662,7 +668,8 @@ drop_nolock:
 static netdev_tx_t ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
 {
        struct ip_tunnel *tunnel = netdev_priv(dev);
-       struct net_device_stats *stats = &tunnel->dev->stats;
+       struct net_device_stats *stats = &dev->stats;
+       struct netdev_queue *txq = netdev_get_tx_queue(dev, 0);
        struct iphdr  *old_iph = ip_hdr(skb);
        struct iphdr  *tiph;
        u8     tos;
@@ -810,7 +817,7 @@ static netdev_tx_t ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev
                struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
                if (!new_skb) {
                        ip_rt_put(rt);
-                       stats->tx_dropped++;
+                       txq->tx_dropped++;
                        dev_kfree_skb(skb);
                        return NETDEV_TX_OK;
                }
@@ -1283,16 +1290,19 @@ static const struct net_protocol ipgre_protocol = {
        .netns_ok       =       1,
 };
 
-static void ipgre_destroy_tunnels(struct ipgre_net *ign)
+static void ipgre_destroy_tunnels(struct ipgre_net *ign, struct list_head *head)
 {
        int prio;
 
        for (prio = 0; prio < 4; prio++) {
                int h;
                for (h = 0; h < HASH_SIZE; h++) {
-                       struct ip_tunnel *t;
-                       while ((t = ign->tunnels[prio][h]) != NULL)
-                               unregister_netdevice(t->dev);
+                       struct ip_tunnel *t = ign->tunnels[prio][h];
+
+                       while (t != NULL) {
+                               unregister_netdevice_queue(t->dev, head);
+                               t = t->next;
+                       }
                }
        }
 }
@@ -1340,10 +1350,12 @@ err_alloc:
 static void ipgre_exit_net(struct net *net)
 {
        struct ipgre_net *ign;
+       LIST_HEAD(list);
 
        ign = net_generic(net, ipgre_net_id);
        rtnl_lock();
-       ipgre_destroy_tunnels(ign);
+       ipgre_destroy_tunnels(ign, &list);
+       unregister_netdevice_many(&list);
        rtnl_unlock();
        kfree(ign);
 }
@@ -1464,14 +1476,14 @@ static void ipgre_tap_setup(struct net_device *dev)
 
        ether_setup(dev);
 
-       dev->netdev_ops         = &ipgre_netdev_ops;
+       dev->netdev_ops         = &ipgre_tap_netdev_ops;
        dev->destructor         = free_netdev;
 
        dev->iflink             = 0;
        dev->features           |= NETIF_F_NETNS_LOCAL;
 }
 
-static int ipgre_newlink(struct net_device *dev, struct nlattr *tb[],
+static int ipgre_newlink(struct net *src_net, struct net_device *dev, struct nlattr *tb[],
                         struct nlattr *data[])
 {
        struct ip_tunnel *nt;
@@ -1525,25 +1537,29 @@ static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[],
                if (t->dev != dev)
                        return -EEXIST;
        } else {
-               unsigned nflags = 0;
-
                t = nt;
 
-               if (ipv4_is_multicast(p.iph.daddr))
-                       nflags = IFF_BROADCAST;
-               else if (p.iph.daddr)
-                       nflags = IFF_POINTOPOINT;
+               if (dev->type != ARPHRD_ETHER) {
+                       unsigned nflags = 0;
 
-               if ((dev->flags ^ nflags) &
-                   (IFF_POINTOPOINT | IFF_BROADCAST))
-                       return -EINVAL;
+                       if (ipv4_is_multicast(p.iph.daddr))
+                               nflags = IFF_BROADCAST;
+                       else if (p.iph.daddr)
+                               nflags = IFF_POINTOPOINT;
+
+                       if ((dev->flags ^ nflags) &
+                           (IFF_POINTOPOINT | IFF_BROADCAST))
+                               return -EINVAL;
+               }
 
                ipgre_tunnel_unlink(ign, t);
                t->parms.iph.saddr = p.iph.saddr;
                t->parms.iph.daddr = p.iph.daddr;
                t->parms.i_key = p.i_key;
-               memcpy(dev->dev_addr, &p.iph.saddr, 4);
-               memcpy(dev->broadcast, &p.iph.daddr, 4);
+               if (dev->type != ARPHRD_ETHER) {
+                       memcpy(dev->dev_addr, &p.iph.saddr, 4);
+                       memcpy(dev->broadcast, &p.iph.daddr, 4);
+               }
                ipgre_tunnel_link(ign, t);
                netdev_state_change(dev);
        }
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