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path: root/drivers/net/wan/lapbether.c
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Diffstat (limited to 'drivers/net/wan/lapbether.c')
-rw-r--r--drivers/net/wan/lapbether.c55
1 files changed, 44 insertions, 11 deletions
diff --git a/drivers/net/wan/lapbether.c b/drivers/net/wan/lapbether.c
index 0e3f8ed84660..3ec922bed2d8 100644
--- a/drivers/net/wan/lapbether.c
+++ b/drivers/net/wan/lapbether.c
@@ -56,6 +56,8 @@ struct lapbethdev {
struct list_head node;
struct net_device *ethdev; /* link to ethernet device */
struct net_device *axdev; /* lapbeth device (lapb#) */
+ bool up;
+ spinlock_t up_lock; /* Protects "up" */
};
static LIST_HEAD(lapbeth_devices);
@@ -103,8 +105,9 @@ static int lapbeth_rcv(struct sk_buff *skb, struct net_device *dev, struct packe
rcu_read_lock();
lapbeth = lapbeth_get_x25_dev(dev);
if (!lapbeth)
- goto drop_unlock;
- if (!netif_running(lapbeth->axdev))
+ goto drop_unlock_rcu;
+ spin_lock_bh(&lapbeth->up_lock);
+ if (!lapbeth->up)
goto drop_unlock;
len = skb->data[0] + skb->data[1] * 256;
@@ -119,11 +122,14 @@ static int lapbeth_rcv(struct sk_buff *skb, struct net_device *dev, struct packe
goto drop_unlock;
}
out:
+ spin_unlock_bh(&lapbeth->up_lock);
rcu_read_unlock();
return 0;
drop_unlock:
kfree_skb(skb);
goto out;
+drop_unlock_rcu:
+ rcu_read_unlock();
drop:
kfree_skb(skb);
return 0;
@@ -151,13 +157,17 @@ static int lapbeth_data_indication(struct net_device *dev, struct sk_buff *skb)
static netdev_tx_t lapbeth_xmit(struct sk_buff *skb,
struct net_device *dev)
{
+ struct lapbethdev *lapbeth = netdev_priv(dev);
int err;
- /*
- * Just to be *really* sure not to send anything if the interface
- * is down, the ethernet device may have gone.
+ spin_lock_bh(&lapbeth->up_lock);
+ if (!lapbeth->up)
+ goto drop;
+
+ /* There should be a pseudo header of 1 byte added by upper layers.
+ * Check to make sure it is there before reading it.
*/
- if (!netif_running(dev))
+ if (skb->len < 1)
goto drop;
switch (skb->data[0]) {
@@ -182,6 +192,7 @@ static netdev_tx_t lapbeth_xmit(struct sk_buff *skb,
goto drop;
}
out:
+ spin_unlock_bh(&lapbeth->up_lock);
return NETDEV_TX_OK;
drop:
kfree_skb(skb);
@@ -195,8 +206,6 @@ static void lapbeth_data_transmit(struct net_device *ndev, struct sk_buff *skb)
struct net_device *dev;
int size = skb->len;
- skb->protocol = htons(ETH_P_X25);
-
ptr = skb_push(skb, 2);
*ptr++ = size % 256;
@@ -207,6 +216,10 @@ static void lapbeth_data_transmit(struct net_device *ndev, struct sk_buff *skb)
skb->dev = dev = lapbeth->ethdev;
+ skb->protocol = htons(ETH_P_DEC);
+
+ skb_reset_network_header(skb);
+
dev_hard_header(skb, dev, ETH_P_DEC, bcast_addr, NULL, 0);
dev_queue_xmit(skb);
@@ -271,6 +284,7 @@ static const struct lapb_register_struct lapbeth_callbacks = {
*/
static int lapbeth_open(struct net_device *dev)
{
+ struct lapbethdev *lapbeth = netdev_priv(dev);
int err;
if ((err = lapb_register(dev, &lapbeth_callbacks)) != LAPB_OK) {
@@ -278,15 +292,21 @@ static int lapbeth_open(struct net_device *dev)
return -ENODEV;
}
- netif_start_queue(dev);
+ spin_lock_bh(&lapbeth->up_lock);
+ lapbeth->up = true;
+ spin_unlock_bh(&lapbeth->up_lock);
+
return 0;
}
static int lapbeth_close(struct net_device *dev)
{
+ struct lapbethdev *lapbeth = netdev_priv(dev);
int err;
- netif_stop_queue(dev);
+ spin_lock_bh(&lapbeth->up_lock);
+ lapbeth->up = false;
+ spin_unlock_bh(&lapbeth->up_lock);
if ((err = lapb_unregister(dev)) != LAPB_OK)
pr_err("lapb_unregister error: %d\n", err);
@@ -308,7 +328,7 @@ static void lapbeth_setup(struct net_device *dev)
dev->netdev_ops = &lapbeth_netdev_ops;
dev->needs_free_netdev = true;
dev->type = ARPHRD_X25;
- dev->hard_header_len = 3;
+ dev->hard_header_len = 0;
dev->mtu = 1000;
dev->addr_len = 0;
}
@@ -329,12 +349,25 @@ static int lapbeth_new_device(struct net_device *dev)
if (!ndev)
goto out;
+ /* When transmitting data:
+ * first this driver removes a pseudo header of 1 byte,
+ * then the lapb module prepends an LAPB header of at most 3 bytes,
+ * then this driver prepends a length field of 2 bytes,
+ * then the underlying Ethernet device prepends its own header.
+ */
+ ndev->needed_headroom = -1 + 3 + 2 + dev->hard_header_len
+ + dev->needed_headroom;
+ ndev->needed_tailroom = dev->needed_tailroom;
+
lapbeth = netdev_priv(ndev);
lapbeth->axdev = ndev;
dev_hold(dev);
lapbeth->ethdev = dev;
+ lapbeth->up = false;
+ spin_lock_init(&lapbeth->up_lock);
+
rc = -EIO;
if (register_netdevice(ndev))
goto fail;