Some changes suggested by Patrick McHardy:

* use sbk_share_check().
* use new and much simpler rtnl API
  - delete list of vcan devices and struct vcan_priv.
  - delete newlink() and dellink() functions.
  To reduce kernel version depencies, the new rtnl API will
  now only be used for 2.6.24 and higher.

git-svn-id: svn://svn.berlios.de//socketcan/trunk@474 030b6a49-0b11-0410-94ab-b0dab22257f2

diff --git a/kernel/2.6/drivers/net/can/vcan.c b/kernel/2.6/drivers/net/can/vcan.c
index b80be3ac1568407009804a7a3ab0ca628dad78c6..238a77d33f48f8d0bf6ed87bc13e02767c319a46 100644 (file)
--- a/kernel/2.6/drivers/net/can/vcan.c
+++ b/kernel/2.6/drivers/net/can/vcan.c
@@ -89,7 +89,7 @@ static void *kzalloc(size_t size, unsigned int __nocast flags)
 }
 #endif
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,24)
 static int numdev = 4; /* default number of virtual CAN interfaces */
 module_param(numdev, int, S_IRUGO);
 MODULE_PARM_DESC(numdev, "Number of virtual CAN devices");
@@ -105,16 +105,14 @@ static int loopback; /* loopback testing. Default: 0 (Off) */
 module_param(loopback, int, S_IRUGO);
 MODULE_PARM_DESC(loopback, "Loop back frames (for testing). Default: 0 (Off)");
 
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,23)
-struct vcan_priv {
-       struct net_device *dev;
-       struct list_head list;
-};
-static LIST_HEAD(vcan_devs);
-#else
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,24)
 static struct net_device **vcan_devs; /* root pointer to netdevice structs */
+#endif
 
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
 #define PRIVSIZE sizeof(struct net_device_stats)
+#elif LINUX_VERSION_CODE < KERNEL_VERSION(2,6,24)
+#define PRIVSIZE 0
 #endif
 
 static int vcan_open(struct net_device *dev)
@@ -191,18 +189,9 @@ static int vcan_tx(struct sk_buff *skb, struct net_device *dev)
        if (loop) {
                struct sock *srcsk = skb->sk;
 
-               if (atomic_read(&skb->users) != 1) {
-                       struct sk_buff *old_skb = skb;
-
-                       skb = skb_clone(old_skb, GFP_ATOMIC);
-                       DBG(KERN_INFO "%s: %s: freeing old skbuff %p, "
-                           "using new skbuff %p\n",
-                           dev->name, __FUNCTION__, old_skb, skb);
-                       kfree_skb(old_skb);
-                       if (!skb)
-                               return 0;
-               } else
-                       skb_orphan(skb);
+               skb = skb_share_check(skb, GFP_ATOMIC);
+               if (!skb)
+                       return 0;
 
                /* receive with packet counting */
                skb->sk = srcsk;
@@ -241,73 +230,36 @@ static void vcan_setup(struct net_device *dev)
        dev->open              = vcan_open;
        dev->stop              = vcan_stop;
        dev->hard_start_xmit   = vcan_tx;
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,23)
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24)
        dev->destructor        = free_netdev;
-#else
+#endif
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
        dev->get_stats         = vcan_get_stats;
 #endif
-
 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,24)
        SET_MODULE_OWNER(dev);
 #endif
 }
 
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,23)
-static int vcan_newlink(struct net_device *dev,
-                       struct nlattr *tb[], struct nlattr *data[])
-{
-       struct vcan_priv *priv = netdev_priv(dev);
-       int err;
-
-       err = register_netdevice(dev);
-       if (err < 0)
-               return err;
-
-       priv->dev = dev;
-       list_add_tail(&priv->list, &vcan_devs);
-       return 0;
-}
-
-static void vcan_dellink(struct net_device *dev)
-{
-       struct vcan_priv *priv = netdev_priv(dev);
-
-       list_del(&priv->list);
-       unregister_netdevice(dev);
-}
-
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24)
 static struct rtnl_link_ops vcan_link_ops __read_mostly = {
        .kind           = "vcan",
-       .priv_size      = sizeof(struct vcan_priv),
        .setup          = vcan_setup,
-       .newlink        = vcan_newlink,
-       .dellink        = vcan_dellink,
 };
 
 static __init int vcan_init_module(void)
 {
-       int err;
-
        printk(banner);
 
        if (loopback)
                printk(KERN_INFO "vcan: enabled loopback on driver level.\n");
 
-       rtnl_lock();
-       err = __rtnl_link_register(&vcan_link_ops);
-       rtnl_unlock();
-       return err;
+       return rtnl_link_register(&vcan_link_ops);
 }
 
 static __exit void vcan_cleanup_module(void)
 {
-       struct vcan_priv *priv, *n;
-
-       rtnl_lock();
-       list_for_each_entry_safe(priv, n, &vcan_devs, list)
-               vcan_dellink(priv->dev);
-       __rtnl_link_unregister(&vcan_link_ops);
-       rtnl_unlock();
+       rtnl_link_unregister(&vcan_link_ops);
 }
 #else
 static __init int vcan_init_module(void)