tuntap: dont use skb after netif_rx_ni(skb)

[linux-block.git] / drivers / net / tun.c

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 607a3a5981c6628a738ca47929a6ad45af51eec2..40b426edc9e6cbab7babc20ee4cb7a9dd2f0bbc6 100644 (file)
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -297,13 +297,12 @@ static void tun_flow_cleanup(unsigned long data)
        spin_unlock_bh(&tun->lock);
 }
 
-static void tun_flow_update(struct tun_struct *tun, struct sk_buff *skb,
+static void tun_flow_update(struct tun_struct *tun, u32 rxhash,
                            u16 queue_index)
 {
        struct hlist_head *head;
        struct tun_flow_entry *e;
        unsigned long delay = tun->ageing_time;
-       u32 rxhash = skb_get_rxhash(skb);
 
        if (!rxhash)
                return;
@@ -493,9 +492,6 @@ static int tun_attach(struct tun_struct *tun, struct file *file)
 
        tun_set_real_num_queues(tun);
 
-       if (tun->numqueues == 1)
-               netif_carrier_on(tun->dev);
-
        /* device is allowed to go away first, so no need to hold extra
         * refcnt.
         */
@@ -693,21 +689,8 @@ static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
         * number of queues.
         */
        if (skb_queue_len(&tfile->socket.sk->sk_receive_queue)
-                         >= dev->tx_queue_len / tun->numqueues){
-               if (!(tun->flags & TUN_ONE_QUEUE)) {
-                       /* Normal queueing mode. */
-                       /* Packet scheduler handles dropping of further packets. */
-                       netif_stop_subqueue(dev, txq);
-
-                       /* We won't see all dropped packets individually, so overrun
-                        * error is more appropriate. */
-                       dev->stats.tx_fifo_errors++;
-               } else {
-                       /* Single queue mode.
-                        * Driver handles dropping of all packets itself. */
-                       goto drop;
-               }
-       }
+                         >= dev->tx_queue_len / tun->numqueues)
+               goto drop;
 
        /* Orphan the skb - required as we might hang on to it
         * for indefinite time. */
@@ -865,6 +848,7 @@ static void tun_net_init(struct net_device *dev)
                /* Ethernet TAP Device */
                ether_setup(dev);
                dev->priv_flags &= ~IFF_TX_SKB_SHARING;
+               dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
 
                eth_hw_addr_random(dev);
 
@@ -1025,6 +1009,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
        int copylen;
        bool zerocopy = false;
        int err;
+       u32 rxhash;
 
        if (!(tun->flags & TUN_NO_PI)) {
                if ((len -= sizeof(pi)) > total_len)
@@ -1177,12 +1162,13 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
                skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
        }
 
+       rxhash = skb_get_rxhash(skb);
        netif_rx_ni(skb);
 
        tun->dev->stats.rx_packets++;
        tun->dev->stats.rx_bytes += len;
 
-       tun_flow_update(tun, skb, tfile->queue_index);
+       tun_flow_update(tun, rxhash, tfile->queue_index);
        return total_len;
 }
 
@@ -1322,7 +1308,6 @@ static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,
                        schedule();
                        continue;
                }
-               netif_wake_subqueue(tun->dev, tfile->queue_index);
 
                ret = tun_put_user(tun, tfile, skb, iv, len);
                kfree_skb(skb);
@@ -1485,6 +1470,9 @@ static int tun_flags(struct tun_struct *tun)
        if (tun->flags & TUN_NO_PI)
                flags |= IFF_NO_PI;
 
+       /* This flag has no real effect.  We track the value for backwards
+        * compatibility.
+        */
        if (tun->flags & TUN_ONE_QUEUE)
                flags |= IFF_ONE_QUEUE;
 
@@ -1605,13 +1593,18 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
 
                tun_net_init(dev);
 
-               if (tun_flow_init(tun))
+               err = tun_flow_init(tun);
+               if (err < 0)
                        goto err_free_dev;
 
                dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST |
                        TUN_USER_FEATURES;
                dev->features = dev->hw_features;
 
+               err = tun_attach(tun, file);
+               if (err < 0)
+                       goto err_free_dev;
+
                err = register_netdevice(tun->dev);
                if (err < 0)
                        goto err_free_dev;
@@ -1621,9 +1614,7 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
                    device_create_file(&tun->dev->dev, &dev_attr_group))
                        pr_err("Failed to create tun sysfs files\n");
 
-               err = tun_attach(tun, file);
-               if (err < 0)
-                       goto err_free_dev;
+               netif_carrier_on(tun->dev);
        }
 
        tun_debug(KERN_INFO, tun, "tun_set_iff\n");
@@ -1633,6 +1624,9 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
        else
                tun->flags &= ~TUN_NO_PI;
 
+       /* This flag has no real effect.  We track the value for backwards
+        * compatibility.
+        */
        if (ifr->ifr_flags & IFF_ONE_QUEUE)
                tun->flags |= TUN_ONE_QUEUE;
        else