diff options
Diffstat (limited to 'drivers/net/wan/lapbether.c')
| -rw-r--r-- | drivers/net/wan/lapbether.c | 25 |
1 files changed, 21 insertions, 4 deletions
diff --git a/drivers/net/wan/lapbether.c b/drivers/net/wan/lapbether.c index 0f1217b506ad..996eb9c55b39 100644 --- a/drivers/net/wan/lapbether.c +++ b/drivers/net/wan/lapbether.c @@ -128,10 +128,12 @@ static int lapbeth_data_indication(struct net_device *dev, struct sk_buff *skb) { unsigned char *ptr; - skb_push(skb, 1); - - if (skb_cow(skb, 1)) + if (skb_cow(skb, 1)) { + kfree_skb(skb); return NET_RX_DROP; + } + + skb_push(skb, 1); ptr = skb->data; *ptr = X25_IFACE_DATA; @@ -155,6 +157,12 @@ static netdev_tx_t lapbeth_xmit(struct sk_buff *skb, if (!netif_running(dev)) 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 (skb->len < 1) + goto drop; + switch (skb->data[0]) { case X25_IFACE_DATA: break; @@ -303,7 +311,7 @@ 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; } @@ -324,6 +332,15 @@ 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; + lapbeth = netdev_priv(ndev); lapbeth->axdev = ndev; |