[PATCH] ipip tunnel dynamic net_device's

[Stephen Hemminger <shemminger@xxxxxxxx>]

Convert ipip tunnel pseudo-driver to use dynamically allocated network devices.
This depends on the alloc_netdev earlier patch.

Tested by creating/deleting and unloading ipip tunnels.

--- linux-2.5/net/ipv4/ipip.c   2003-06-05 10:04:53.000000000 -0700
+++ linux-2.5-dyn/net/ipv4/ipip.c       2003-06-12 14:02:34.000000000 -0700
@@ -122,16 +122,9 @@
 
 static int ipip_fb_tunnel_init(struct net_device *dev);
 static int ipip_tunnel_init(struct net_device *dev);
+static void ipip_tunnel_setup(struct net_device *dev);
 
-static struct net_device ipip_fb_tunnel_dev = {
-       .name = "tunl0",
-       .init = ipip_fb_tunnel_init,
-};
-
-static struct ip_tunnel ipip_fb_tunnel = {
-       .dev =  &ipip_fb_tunnel_dev,
-       .parms ={ .name = "tunl0", }
-};
+static struct net_device *ipip_fb_tunnel_dev;
 
 static struct ip_tunnel *tunnels_r_l[HASH_SIZE];
 static struct ip_tunnel *tunnels_r[HASH_SIZE];
@@ -216,6 +209,7 @@ static struct ip_tunnel * ipip_tunnel_lo
        struct net_device *dev;
        unsigned h = 0;
        int prio = 0;
+       char name[IFNAMSIZ];
 
        if (remote) {
                prio |= 2;
@@ -232,32 +226,33 @@ static struct ip_tunnel * ipip_tunnel_lo
        if (!create)
                return NULL;
 
-       dev = kmalloc(sizeof(*dev) + sizeof(*t), GFP_KERNEL);
-       if (dev == NULL)
-               return NULL;
-
-       memset(dev, 0, sizeof(*dev) + sizeof(*t));
-       dev->priv = (void*)(dev+1);
-       nt = (struct ip_tunnel*)dev->priv;
-       nt->dev = dev;
-       dev->init = ipip_tunnel_init;
-       memcpy(&nt->parms, parms, sizeof(*parms));
-       nt->parms.name[IFNAMSIZ-1] = '\0';
-       strcpy(dev->name, nt->parms.name);
-       if (dev->name[0] == 0) {
+       if (parms->name[0])
+               strlcpy(name, parms->name, IFNAMSIZ);
+       else {
                int i;
                for (i=1; i<100; i++) {
-                       sprintf(dev->name, "tunl%d", i);
-                       if (__dev_get_by_name(dev->name) == NULL)
+                       sprintf(name, "tunl%d", i);
+                       if (__dev_get_by_name(name) == NULL)
                                break;
                }
                if (i==100)
                        goto failed;
-               memcpy(nt->parms.name, dev->name, IFNAMSIZ);
        }
+
+       dev = alloc_netdev(sizeof(*t), name, ipip_tunnel_setup);
+       if (dev == NULL)
+               return NULL;
+
+       nt = dev->priv;
        SET_MODULE_OWNER(dev);
-       if (register_netdevice(dev) < 0)
+       dev->init = ipip_tunnel_init;
+       dev->destructor = (void (*)(struct net_device *))kfree;
+       nt->parms = *parms;
+
+       if (register_netdevice(dev) < 0) {
+               kfree(dev);
                goto failed;
+       }
 
        dev_hold(dev);
        ipip_tunnel_link(nt);
@@ -265,19 +260,12 @@ static struct ip_tunnel * ipip_tunnel_lo
        return nt;
 
 failed:
-       kfree(dev);
        return NULL;
 }
 
-static void ipip_tunnel_destructor(struct net_device *dev)
-{
-       if (dev != &ipip_fb_tunnel_dev)
-               kfree(dev);
-}
-
 static void ipip_tunnel_uninit(struct net_device *dev)
 {
-       if (dev == &ipip_fb_tunnel_dev) {
+       if (dev == ipip_fb_tunnel_dev) {
                write_lock_bh(&ipip_lock);
                tunnels_wc[0] = NULL;
                write_unlock_bh(&ipip_lock);
@@ -682,7 +670,7 @@ ipip_tunnel_ioctl (struct net_device *de
        switch (cmd) {
        case SIOCGETTUNNEL:
                t = NULL;
-               if (dev == &ipip_fb_tunnel_dev) {
+               if (dev == ipip_fb_tunnel_dev) {
                        if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, 
sizeof(p))) {
                                err = -EFAULT;
                                break;
@@ -715,8 +703,7 @@ ipip_tunnel_ioctl (struct net_device *de
 
                t = ipip_tunnel_locate(&p, cmd == SIOCADDTUNNEL);
 
-               if (dev != &ipip_fb_tunnel_dev && cmd == SIOCCHGTUNNEL &&
-                   t != &ipip_fb_tunnel) {
+               if (dev != ipip_fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
                        if (t != NULL) {
                                if (t->dev != dev) {
                                        err = -EEXIST;
@@ -757,7 +744,7 @@ ipip_tunnel_ioctl (struct net_device *de
                if (!capable(CAP_NET_ADMIN))
                        goto done;
 
-               if (dev == &ipip_fb_tunnel_dev) {
+               if (dev == ipip_fb_tunnel_dev) {
                        err = -EFAULT;
                        if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, 
sizeof(p)))
                                goto done;
@@ -765,7 +752,7 @@ ipip_tunnel_ioctl (struct net_device *de
                        if ((t = ipip_tunnel_locate(&p, 0)) == NULL)
                                goto done;
                        err = -EPERM;
-                       if (t == &ipip_fb_tunnel)
+                       if (t->dev == ipip_fb_tunnel_dev)
                                goto done;
                        dev = t->dev;
                }
@@ -793,12 +780,10 @@ static int ipip_tunnel_change_mtu(struct
        return 0;
 }
 
-static void ipip_tunnel_init_gen(struct net_device *dev)
+static void ipip_tunnel_setup(struct net_device *dev)
 {
-       struct ip_tunnel *t = (struct ip_tunnel*)dev->priv;
-
+       SET_MODULE_OWNER(dev);
        dev->uninit             = ipip_tunnel_uninit;
-       dev->destructor         = ipip_tunnel_destructor;
        dev->hard_start_xmit    = ipip_tunnel_xmit;
        dev->get_stats          = ipip_tunnel_get_stats;
        dev->do_ioctl           = ipip_tunnel_ioctl;
@@ -810,8 +795,6 @@ static void ipip_tunnel_init_gen(struct 
        dev->flags              = IFF_NOARP;
        dev->iflink             = 0;
        dev->addr_len           = 4;
-       memcpy(dev->dev_addr, &t->parms.iph.saddr, 4);
-       memcpy(dev->broadcast, &t->parms.iph.daddr, 4);
 }
 
 static int ipip_tunnel_init(struct net_device *dev)
@@ -822,8 +805,9 @@ static int ipip_tunnel_init(struct net_d
 
        tunnel = (struct ip_tunnel*)dev->priv;
        iph = &tunnel->parms.iph;
-
-       ipip_tunnel_init_gen(dev);
+       tunnel->dev = dev;
+       memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
+       memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
 
        if (iph->daddr) {
                struct flowi fl = { .oif = tunnel->parms.link,
@@ -854,17 +838,15 @@ static int ipip_tunnel_init(struct net_d
 
 static int __init ipip_fb_tunnel_init(struct net_device *dev)
 {
-       struct iphdr *iph;
-
-       ipip_tunnel_init_gen(dev);
+       struct ip_tunnel *tunnel = dev->priv;
+       struct iphdr *iph = &tunnel->parms.iph;
 
-       iph = &ipip_fb_tunnel.parms.iph;
        iph->version            = 4;
        iph->protocol           = IPPROTO_IPIP;
        iph->ihl                = 5;
 
        dev_hold(dev);
-       tunnels_wc[0]           = &ipip_fb_tunnel;
+       tunnels_wc[0]           = tunnel;
        return 0;
 }
 
@@ -878,6 +860,8 @@ static char banner[] __initdata =
 
 int __init ipip_init(void)
 {
+       int err;
+
        printk(banner);
 
        if (xfrm4_tunnel_register(&ipip_handler) < 0) {
@@ -885,10 +869,24 @@ int __init ipip_init(void)
                return -EAGAIN;
        }
 
-       ipip_fb_tunnel_dev.priv = (void*)&ipip_fb_tunnel;
-       SET_MODULE_OWNER(&ipip_fb_tunnel_dev);
-       register_netdev(&ipip_fb_tunnel_dev);
-       return 0;
+       ipip_fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel),
+                                          "tunl0",
+                                          ipip_tunnel_setup);
+       if (!ipip_fb_tunnel_dev) {
+               err = -ENOMEM;
+               goto fail;
+       }
+
+       ipip_fb_tunnel_dev->init = ipip_fb_tunnel_init;
+
+       if ((err = register_netdev(ipip_fb_tunnel_dev)))
+           goto fail;
+ out:
+       return err;
+ fail:
+       xfrm4_tunnel_deregister(&ipip_handler);
+       kfree(ipip_fb_tunnel_dev);
+       goto out;
 }
 
 static void __exit ipip_fini(void)
@@ -896,7 +894,7 @@ static void __exit ipip_fini(void)
        if (xfrm4_tunnel_deregister(&ipip_handler) < 0)
                printk(KERN_INFO "ipip close: can't deregister tunnel\n");
 
-       unregister_netdev(&ipip_fb_tunnel_dev);
+       unregister_netdev(ipip_fb_tunnel_dev);
 }
 
 #ifdef MODULE