Phonet: routing table backend
Rémi Denis-Courmont [Wed, 14 Oct 2009 00:48:28 +0000 (00:48 +0000)]
The Phonet "universe" only has 64 addresses, so we keep a trivial flat
routing table.

Signed-off-by: Rémi Denis-Courmont <remi.denis-courmont@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/phonet/pn_dev.h
net/phonet/pn_dev.c

index 44c923c..87b5d81 100644 (file)
@@ -47,6 +47,11 @@ u8 phonet_address_get(struct net_device *dev, u8 addr);
 int phonet_address_lookup(struct net *net, u8 addr);
 void phonet_address_notify(int event, struct net_device *dev, u8 addr);
 
+int phonet_route_add(struct net_device *dev, u8 daddr);
+int phonet_route_del(struct net_device *dev, u8 daddr);
+struct net_device *phonet_route_get(struct net *net, u8 daddr);
+struct net_device *phonet_route_output(struct net *net, u8 daddr);
+
 #define PN_NO_ADDR     0xff
 
 extern const struct file_operations pn_sock_seq_fops;
index 5f42f30..71fffa5 100644 (file)
 #include <net/netns/generic.h>
 #include <net/phonet/pn_dev.h>
 
+struct phonet_routes {
+       spinlock_t              lock;
+       struct net_device       *table[64];
+};
+
 struct phonet_net {
        struct phonet_device_list pndevs;
+       struct phonet_routes routes;
 };
 
 int phonet_net_id;
@@ -154,10 +160,11 @@ int phonet_address_del(struct net_device *dev, u8 addr)
 }
 
 /* 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_list *pndevs = phonet_device_list(dev_net(dev));
        struct phonet_device *pnd;
+       u8 saddr;
 
        spin_lock_bh(&pndevs->lock);
        pnd = __phonet_get(dev);
@@ -165,12 +172,26 @@ u8 phonet_address_get(struct net_device *dev, u8 addr)
                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;
+               saddr = PN_NO_ADDR;
        spin_unlock_bh(&pndevs->lock);
-       return addr;
+
+       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)
@@ -246,7 +267,7 @@ static struct notifier_block phonet_device_notifier = {
 /* Per-namespace Phonet devices handling */
 static int phonet_init_net(struct net *net)
 {
-       struct phonet_net *pnn = kmalloc(sizeof(*pnn), GFP_KERNEL);
+       struct phonet_net *pnn = kzalloc(sizeof(*pnn), GFP_KERNEL);
        if (!pnn)
                return -ENOMEM;
 
@@ -257,6 +278,7 @@ static int phonet_init_net(struct net *net)
 
        INIT_LIST_HEAD(&pnn->pndevs.list);
        spin_lock_init(&pnn->pndevs.lock);
+       spin_lock_init(&pnn->routes.lock);
        net_assign_generic(net, phonet_net_id, pnn);
        return 0;
 }
@@ -300,3 +322,69 @@ void phonet_device_exit(void)
        unregister_netdevice_notifier(&phonet_device_notifier);
        unregister_pernet_gen_device(phonet_net_id, &phonet_net_ops);
 }
+
+int phonet_route_add(struct net_device *dev, u8 daddr)
+{
+       struct phonet_net *pnn = net_generic(dev_net(dev), phonet_net_id);
+       struct phonet_routes *routes = &pnn->routes;
+       int err = -EEXIST;
+
+       daddr = daddr >> 2;
+       spin_lock_bh(&routes->lock);
+       if (routes->table[daddr] == NULL) {
+               routes->table[daddr] = dev;
+               dev_hold(dev);
+               err = 0;
+       }
+       spin_unlock_bh(&routes->lock);
+       return err;
+}
+
+int phonet_route_del(struct net_device *dev, u8 daddr)
+{
+       struct phonet_net *pnn = net_generic(dev_net(dev), phonet_net_id);
+       struct phonet_routes *routes = &pnn->routes;
+       int err = -ENOENT;
+
+       daddr = daddr >> 2;
+       spin_lock_bh(&routes->lock);
+       if (dev == routes->table[daddr]) {
+               routes->table[daddr] = NULL;
+               dev_put(dev);
+               err = 0;
+       }
+       spin_unlock_bh(&routes->lock);
+       return err;
+}
+
+struct net_device *phonet_route_get(struct net *net, u8 daddr)
+{
+       struct phonet_net *pnn = net_generic(net, phonet_net_id);
+       struct phonet_routes *routes = &pnn->routes;
+       struct net_device *dev;
+
+       ASSERT_RTNL(); /* no need to hold the device */
+
+       daddr >>= 2;
+       spin_lock_bh(&routes->lock);
+       dev = routes->table[daddr];
+       spin_unlock_bh(&routes->lock);
+       return dev;
+}
+
+struct net_device *phonet_route_output(struct net *net, u8 daddr)
+{
+       struct phonet_net *pnn = net_generic(net, phonet_net_id);
+       struct phonet_routes *routes = &pnn->routes;
+       struct net_device *dev;
+
+       spin_lock_bh(&routes->lock);
+       dev = routes->table[daddr >> 2];
+       if (dev)
+               dev_hold(dev);
+       spin_unlock_bh(&routes->lock);
+
+       if (!dev)
+               dev = phonet_device_get(net); /* Default route */
+       return dev;
+}