ipv4: fix redirect handling
[linux-2.6.git] / net / phonet / pn_dev.c
index af49db0..d2df8f3 100644 (file)
 
 #include <linux/kernel.h>
 #include <linux/net.h>
+#include <linux/slab.h>
 #include <linux/netdevice.h>
 #include <linux/phonet.h>
+#include <linux/proc_fs.h>
+#include <linux/if_arp.h>
 #include <net/sock.h>
+#include <net/netns/generic.h>
 #include <net/phonet/pn_dev.h>
 
-/* when accessing, remember to lock with spin_lock(&pndevs.lock); */
-struct phonet_device_list pndevs = {
-       .list = LIST_HEAD_INIT(pndevs.list),
-       .lock = __SPIN_LOCK_UNLOCKED(pndevs.lock),
+struct phonet_routes {
+       struct mutex            lock;
+       struct net_device       *table[64];
 };
 
+struct phonet_net {
+       struct phonet_device_list pndevs;
+       struct phonet_routes routes;
+};
+
+int phonet_net_id __read_mostly;
+
+static struct phonet_net *phonet_pernet(struct net *net)
+{
+       BUG_ON(!net);
+
+       return net_generic(net, phonet_net_id);
+}
+
+struct phonet_device_list *phonet_device_list(struct net *net)
+{
+       struct phonet_net *pnn = phonet_pernet(net);
+       return &pnn->pndevs;
+}
+
 /* Allocate new Phonet device. */
 static struct phonet_device *__phonet_device_alloc(struct net_device *dev)
 {
+       struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
        struct phonet_device *pnd = kmalloc(sizeof(*pnd), GFP_ATOMIC);
        if (pnd == NULL)
                return NULL;
        pnd->netdev = dev;
        bitmap_zero(pnd->addrs, 64);
 
-       list_add(&pnd->list, &pndevs.list);
+       BUG_ON(!mutex_is_locked(&pndevs->lock));
+       list_add_rcu(&pnd->list, &pndevs->list);
        return pnd;
 }
 
 static struct phonet_device *__phonet_get(struct net_device *dev)
 {
+       struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
        struct phonet_device *pnd;
 
-       list_for_each_entry(pnd, &pndevs.list, list) {
+       BUG_ON(!mutex_is_locked(&pndevs->lock));
+       list_for_each_entry(pnd, &pndevs->list, list) {
                if (pnd->netdev == dev)
                        return pnd;
        }
        return NULL;
 }
 
-static void __phonet_device_free(struct phonet_device *pnd)
+static struct phonet_device *__phonet_get_rcu(struct net_device *dev)
 {
-       list_del(&pnd->list);
-       kfree(pnd);
+       struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
+       struct phonet_device *pnd;
+
+       list_for_each_entry_rcu(pnd, &pndevs->list, list) {
+               if (pnd->netdev == dev)
+                       return pnd;
+       }
+       return NULL;
+}
+
+static void phonet_device_destroy(struct net_device *dev)
+{
+       struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
+       struct phonet_device *pnd;
+
+       ASSERT_RTNL();
+
+       mutex_lock(&pndevs->lock);
+       pnd = __phonet_get(dev);
+       if (pnd)
+               list_del_rcu(&pnd->list);
+       mutex_unlock(&pndevs->lock);
+
+       if (pnd) {
+               u8 addr;
+
+               for_each_set_bit(addr, pnd->addrs, 64)
+                       phonet_address_notify(RTM_DELADDR, dev, addr);
+               kfree(pnd);
+       }
 }
 
 struct net_device *phonet_device_get(struct net *net)
 {
+       struct phonet_device_list *pndevs = phonet_device_list(net);
        struct phonet_device *pnd;
-       struct net_device *dev;
+       struct net_device *dev = NULL;
 
-       spin_lock_bh(&pndevs.lock);
-       list_for_each_entry(pnd, &pndevs.list, list) {
+       rcu_read_lock();
+       list_for_each_entry_rcu(pnd, &pndevs->list, list) {
                dev = pnd->netdev;
                BUG_ON(!dev);
 
-               if (net_eq(dev_net(dev), net) &&
-                       (dev->reg_state == NETREG_REGISTERED) &&
+               if ((dev->reg_state == NETREG_REGISTERED) &&
                        ((pnd->netdev->flags & IFF_UP)) == IFF_UP)
                        break;
                dev = NULL;
        }
        if (dev)
                dev_hold(dev);
-       spin_unlock_bh(&pndevs.lock);
+       rcu_read_unlock();
        return dev;
 }
 
 int phonet_address_add(struct net_device *dev, u8 addr)
 {
+       struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
        struct phonet_device *pnd;
        int err = 0;
 
-       spin_lock_bh(&pndevs.lock);
+       mutex_lock(&pndevs->lock);
        /* Find or create Phonet-specific device data */
        pnd = __phonet_get(dev);
        if (pnd == NULL)
@@ -102,64 +158,136 @@ int phonet_address_add(struct net_device *dev, u8 addr)
                err = -ENOMEM;
        else if (test_and_set_bit(addr >> 2, pnd->addrs))
                err = -EEXIST;
-       spin_unlock_bh(&pndevs.lock);
+       mutex_unlock(&pndevs->lock);
        return err;
 }
 
 int phonet_address_del(struct net_device *dev, u8 addr)
 {
+       struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
        struct phonet_device *pnd;
        int err = 0;
 
-       spin_lock_bh(&pndevs.lock);
+       mutex_lock(&pndevs->lock);
        pnd = __phonet_get(dev);
-       if (!pnd || !test_and_clear_bit(addr >> 2, pnd->addrs))
+       if (!pnd || !test_and_clear_bit(addr >> 2, pnd->addrs)) {
                err = -EADDRNOTAVAIL;
-       else if (bitmap_empty(pnd->addrs, 64))
-               __phonet_device_free(pnd);
-       spin_unlock_bh(&pndevs.lock);
+               pnd = NULL;
+       } else if (bitmap_empty(pnd->addrs, 64))
+               list_del_rcu(&pnd->list);
+       else
+               pnd = NULL;
+       mutex_unlock(&pndevs->lock);
+
+       if (pnd)
+               kfree_rcu(pnd, rcu);
+
        return err;
 }
 
 /* Gets a source address toward a destination, through a interface. */
-u8 phonet_address_get(struct net_device *dev, u8 addr)
+u8 phonet_address_get(struct net_device *dev, u8 daddr)
 {
        struct phonet_device *pnd;
+       u8 saddr;
 
-       spin_lock_bh(&pndevs.lock);
-       pnd = __phonet_get(dev);
+       rcu_read_lock();
+       pnd = __phonet_get_rcu(dev);
        if (pnd) {
                BUG_ON(bitmap_empty(pnd->addrs, 64));
 
                /* Use same source address as destination, if possible */
-               if (!test_bit(addr >> 2, pnd->addrs))
-                       addr = find_first_bit(pnd->addrs, 64) << 2;
+               if (test_bit(daddr >> 2, pnd->addrs))
+                       saddr = daddr;
+               else
+                       saddr = find_first_bit(pnd->addrs, 64) << 2;
        } else
-               addr = PN_NO_ADDR;
-       spin_unlock_bh(&pndevs.lock);
-       return addr;
+               saddr = PN_NO_ADDR;
+       rcu_read_unlock();
+
+       if (saddr == PN_NO_ADDR) {
+               /* Fallback to another device */
+               struct net_device *def_dev;
+
+               def_dev = phonet_device_get(dev_net(dev));
+               if (def_dev) {
+                       if (def_dev != dev)
+                               saddr = phonet_address_get(def_dev, daddr);
+                       dev_put(def_dev);
+               }
+       }
+       return saddr;
 }
 
 int phonet_address_lookup(struct net *net, u8 addr)
 {
+       struct phonet_device_list *pndevs = phonet_device_list(net);
        struct phonet_device *pnd;
+       int err = -EADDRNOTAVAIL;
 
-       spin_lock_bh(&pndevs.lock);
-       list_for_each_entry(pnd, &pndevs.list, list) {
-               if (!net_eq(dev_net(pnd->netdev), net))
-                       continue;
+       rcu_read_lock();
+       list_for_each_entry_rcu(pnd, &pndevs->list, list) {
                /* Don't allow unregistering devices! */
                if ((pnd->netdev->reg_state != NETREG_REGISTERED) ||
                                ((pnd->netdev->flags & IFF_UP)) != IFF_UP)
                        continue;
 
                if (test_bit(addr >> 2, pnd->addrs)) {
-                       spin_unlock_bh(&pndevs.lock);
-                       return 0;
+                       err = 0;
+                       goto found;
+               }
+       }
+found:
+       rcu_read_unlock();
+       return err;
+}
+
+/* automatically configure a Phonet device, if supported */
+static int phonet_device_autoconf(struct net_device *dev)
+{
+       struct if_phonet_req req;
+       int ret;
+
+       if (!dev->netdev_ops->ndo_do_ioctl)
+               return -EOPNOTSUPP;
+
+       ret = dev->netdev_ops->ndo_do_ioctl(dev, (struct ifreq *)&req,
+                                               SIOCPNGAUTOCONF);
+       if (ret < 0)
+               return ret;
+
+       ASSERT_RTNL();
+       ret = phonet_address_add(dev, req.ifr_phonet_autoconf.device);
+       if (ret)
+               return ret;
+       phonet_address_notify(RTM_NEWADDR, dev,
+                               req.ifr_phonet_autoconf.device);
+       return 0;
+}
+
+static void phonet_route_autodel(struct net_device *dev)
+{
+       struct phonet_net *pnn = phonet_pernet(dev_net(dev));
+       unsigned i;
+       DECLARE_BITMAP(deleted, 64);
+
+       /* Remove left-over Phonet routes */
+       bitmap_zero(deleted, 64);
+       mutex_lock(&pnn->routes.lock);
+       for (i = 0; i < 64; i++)
+               if (dev == pnn->routes.table[i]) {
+                       rcu_assign_pointer(pnn->routes.table[i], NULL);
+                       set_bit(i, deleted);
                }
+       mutex_unlock(&pnn->routes.lock);
+
+       if (bitmap_empty(deleted, 64))
+               return; /* short-circuit RCU */
+       synchronize_rcu();
+       for_each_set_bit(i, deleted, 64) {
+               rtm_phonet_notify(RTM_DELROUTE, dev, i);
+               dev_put(dev);
        }
-       spin_unlock_bh(&pndevs.lock);
-       return -EADDRNOTAVAIL;
 }
 
 /* notify Phonet of device events */
@@ -168,15 +296,15 @@ static int phonet_device_notify(struct notifier_block *me, unsigned long what,
 {
        struct net_device *dev = arg;
 
-       if (what == NETDEV_UNREGISTER) {
-               struct phonet_device *pnd;
-
-               /* Destroy phonet-specific device data */
-               spin_lock_bh(&pndevs.lock);
-               pnd = __phonet_get(dev);
-               if (pnd)
-                       __phonet_device_free(pnd);
-               spin_unlock_bh(&pndevs.lock);
+       switch (what) {
+       case NETDEV_REGISTER:
+               if (dev->type == ARPHRD_PHONET)
+                       phonet_device_autoconf(dev);
+               break;
+       case NETDEV_UNREGISTER:
+               phonet_device_destroy(dev);
+               phonet_route_autodel(dev);
+               break;
        }
        return 0;
 
@@ -187,26 +315,134 @@ static struct notifier_block phonet_device_notifier = {
        .priority = 0,
 };
 
+/* Per-namespace Phonet devices handling */
+static int __net_init phonet_init_net(struct net *net)
+{
+       struct phonet_net *pnn = phonet_pernet(net);
+
+       if (!proc_net_fops_create(net, "phonet", 0, &pn_sock_seq_fops))
+               return -ENOMEM;
+
+       INIT_LIST_HEAD(&pnn->pndevs.list);
+       mutex_init(&pnn->pndevs.lock);
+       mutex_init(&pnn->routes.lock);
+       return 0;
+}
+
+static void __net_exit phonet_exit_net(struct net *net)
+{
+       struct phonet_net *pnn = phonet_pernet(net);
+       struct net_device *dev;
+       unsigned i;
+
+       rtnl_lock();
+       for_each_netdev(net, dev)
+               phonet_device_destroy(dev);
+
+       for (i = 0; i < 64; i++) {
+               dev = pnn->routes.table[i];
+               if (dev) {
+                       rtm_phonet_notify(RTM_DELROUTE, dev, i);
+                       dev_put(dev);
+               }
+       }
+       rtnl_unlock();
+
+       proc_net_remove(net, "phonet");
+}
+
+static struct pernet_operations phonet_net_ops = {
+       .init = phonet_init_net,
+       .exit = phonet_exit_net,
+       .id   = &phonet_net_id,
+       .size = sizeof(struct phonet_net),
+};
+
 /* Initialize Phonet devices list */
 int __init phonet_device_init(void)
 {
+       int err = register_pernet_device(&phonet_net_ops);
+       if (err)
+               return err;
+
+       proc_net_fops_create(&init_net, "pnresource", 0, &pn_res_seq_fops);
        register_netdevice_notifier(&phonet_device_notifier);
-       phonet_netlink_register();
-       return 0;
+       err = phonet_netlink_register();
+       if (err)
+               phonet_device_exit();
+       return err;
 }
 
 void phonet_device_exit(void)
 {
-       struct phonet_device *pnd, *n;
-
        rtnl_unregister_all(PF_PHONET);
-       rtnl_lock();
-       spin_lock_bh(&pndevs.lock);
+       unregister_netdevice_notifier(&phonet_device_notifier);
+       unregister_pernet_device(&phonet_net_ops);
+       proc_net_remove(&init_net, "pnresource");
+}
 
-       list_for_each_entry_safe(pnd, n, &pndevs.list, list)
-               __phonet_device_free(pnd);
+int phonet_route_add(struct net_device *dev, u8 daddr)
+{
+       struct phonet_net *pnn = phonet_pernet(dev_net(dev));
+       struct phonet_routes *routes = &pnn->routes;
+       int err = -EEXIST;
 
-       spin_unlock_bh(&pndevs.lock);
-       rtnl_unlock();
-       unregister_netdevice_notifier(&phonet_device_notifier);
+       daddr = daddr >> 2;
+       mutex_lock(&routes->lock);
+       if (routes->table[daddr] == NULL) {
+               rcu_assign_pointer(routes->table[daddr], dev);
+               dev_hold(dev);
+               err = 0;
+       }
+       mutex_unlock(&routes->lock);
+       return err;
+}
+
+int phonet_route_del(struct net_device *dev, u8 daddr)
+{
+       struct phonet_net *pnn = phonet_pernet(dev_net(dev));
+       struct phonet_routes *routes = &pnn->routes;
+
+       daddr = daddr >> 2;
+       mutex_lock(&routes->lock);
+       if (dev == routes->table[daddr])
+               rcu_assign_pointer(routes->table[daddr], NULL);
+       else
+               dev = NULL;
+       mutex_unlock(&routes->lock);
+
+       if (!dev)
+               return -ENOENT;
+       synchronize_rcu();
+       dev_put(dev);
+       return 0;
+}
+
+struct net_device *phonet_route_get_rcu(struct net *net, u8 daddr)
+{
+       struct phonet_net *pnn = phonet_pernet(net);
+       struct phonet_routes *routes = &pnn->routes;
+       struct net_device *dev;
+
+       daddr >>= 2;
+       dev = rcu_dereference(routes->table[daddr]);
+       return dev;
+}
+
+struct net_device *phonet_route_output(struct net *net, u8 daddr)
+{
+       struct phonet_net *pnn = phonet_pernet(net);
+       struct phonet_routes *routes = &pnn->routes;
+       struct net_device *dev;
+
+       daddr >>= 2;
+       rcu_read_lock();
+       dev = rcu_dereference(routes->table[daddr]);
+       if (dev)
+               dev_hold(dev);
+       rcu_read_unlock();
+
+       if (!dev)
+               dev = phonet_device_get(net); /* Default route */
+       return dev;
 }