put IP addresses into xenstore

diff -r 332bdc354197 drivers/xen/netfront/netfront.c
@@ -45,12 +45,17 @@
 #include <linux/bitops.h>
 #include <linux/proc_fs.h>
 #include <linux/ethtool.h>
+#include <linux/ipv6.h>
+
 #include <net/sock.h>
 #include <net/pkt_sched.h>
 #include <net/arp.h>
 #include <net/route.h>
+#include <net/addrconf.h>
+
 #include <asm/io.h>
 #include <asm/uaccess.h>
+
 #include <xen/evtchn.h>
 #include <xen/xenbus.h>
 #include <xen/interface/io/netif.h>

@@ -83,6 +88,13 @@
 static multicall_entry_t rx_mcl[NET_RX_RING_SIZE+1];
 static mmu_update_t rx_mmu[NET_RX_RING_SIZE];
 
+struct netfront_addr {
+	int               nr;
+	char              addr[64];
+	void              *ifa;
+	struct list_head  next;
+};
+
 struct netfront_info
 {
 	struct list_head list;

@@ -133,6 +145,9 @@
 	int tx_ring_ref;
 	int rx_ring_ref;
 	u8 mac[ETH_ALEN];
+
+	struct list_head addrs;
+	int              addr_nr;
 };
 
 /* Access macros for acquiring freeing slots in {tx,rx}_skbs[]. */

@@ -224,6 +239,7 @@
 
 	info = netdev_priv(netdev);
 	dev->data = info;
+	INIT_LIST_HEAD(&info->addrs);
 
 	err = talk_to_backend(dev, info);
 	if (err) {

@@ -442,6 +458,55 @@
 	return dev_queue_xmit(skb);
 }
 
+static int xenbus_address(struct net_device *netdev,
+			  struct netfront_addr *addr, int add)
+{
+	struct netfront_info *info = netdev_priv(netdev);
+	struct xenbus_device *dev = info->xbdev;
+	struct xenbus_transaction *xbt;
+	char *message, path[16];
+	int err = 0;
+
+	printk(KERN_DEBUG "%s: %s: %s #%d %s\n", __FUNCTION__, netdev->name,
+	       add ? "add" : "del", addr->nr, addr->addr);
+ again:
+	xbt = xenbus_transaction_start();
+	if (IS_ERR(xbt)) {
+		xenbus_dev_fatal(dev, err, "starting transaction");
+		goto err;
+	}
+
+	snprintf(path, sizeof(path), "addrs/%d", addr->nr);
+	if (add) {
+		err = xenbus_printf(xbt, dev->nodename, path, "%s", addr->addr);
+		if (err) {
+			message = "adding address";
+			goto abort_transaction;
+		}
+	} else {
+		err = xenbus_rm(xbt, dev->nodename, path);
+		if (err) {
+			message = "deleting address";
+			goto abort_transaction;
+		}
+	}
+
+	err = xenbus_transaction_end(xbt, 0);
+	if (err) {
+		if (err == -EAGAIN)
+			goto again;
+		xenbus_dev_fatal(dev, err, "completing transaction");
+		goto err;
+	}
+
+	return 0;
+
+ abort_transaction:
+	xenbus_transaction_end(xbt, 1);
+	xenbus_dev_fatal(dev, err, "%s", message);
+ err:
+	return -1;
+}
 
 static int network_open(struct net_device *dev)
 {

@@ -1147,19 +1212,87 @@
  * We use this notifier to send out a fake ARP reply to reset switches and
  * router ARP caches when an IP interface is brought up on a VIF.
  */
+
+static struct netfront_addr* get_netfront_addr(struct net_device *netdev, void *ifa)
+{
+	struct netfront_info *info = netdev_priv(netdev);
+	struct netfront_addr *addr;
+
+	list_for_each_entry(addr, &info->addrs, next)
+		if (addr->ifa == ifa)
+			return addr;
+
+	addr = kzalloc(sizeof(*addr), GFP_KERNEL);
+	if (NULL == addr)
+		goto out;
+	addr->nr = info->addr_nr++;
+	addr->ifa = ifa;
+	list_add_tail(&addr->next, &info->addrs);
+ out:
+	return addr;
+}
+
 static int 
 inetdev_notify(struct notifier_block *this, unsigned long event, void *ptr)
 {
-	struct in_ifaddr  *ifa = (struct in_ifaddr *)ptr; 
+	struct in_ifaddr  *ifa = ptr; 
 	struct net_device *dev = ifa->ifa_dev->dev;
-
-	/* UP event and is it one of our devices? */
-	if (event == NETDEV_UP && dev->open == network_open)
-		(void)send_fake_arp(dev);
-        
+	struct netfront_addr *addr;
+
+	/* is it one of our devices? */
+	if (dev->open != network_open)
+		return NOTIFY_DONE;
+
+	addr = get_netfront_addr(dev, ifa);
+	switch (event) {
+	case NETDEV_UP:
+		send_fake_arp(dev);
+		snprintf(addr->addr, sizeof(addr->addr),
+			 "inet %u.%u.%u.%u/%d",
+			 NIPQUAD(ifa->ifa_address), ifa->ifa_prefixlen);
+		xenbus_address(dev, addr, 1);
+		break;
+	case NETDEV_DOWN:
+		xenbus_address(dev, addr, 0);
+		list_del(&addr->next);
+		kfree(addr);
+		break;
+	}
+
 	return NOTIFY_DONE;
 }
 
+#ifdef CONFIG_IPV6
+/* FIXME: how deal with ipv6 being a module ??? */
+static int 
+inet6dev_notify(struct notifier_block *this, unsigned long event, void *ptr)
+{
+	struct inet6_ifaddr *ifa = ptr; 
+	struct net_device   *dev = ifa->idev->dev;
+	struct netfront_addr *addr;
+
+	/* is it one of our devices? */
+	if (dev->open != network_open)
+		return NOTIFY_DONE;
+
+	addr = get_netfront_addr(dev, ifa);
+	switch (event) {
+	case NETDEV_UP:
+		snprintf(addr->addr, sizeof(addr->addr),
+			 "inet6 %04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x/%d",
+			 NIP6(ifa->addr), ifa->prefix_len);
+		xenbus_address(dev, addr, 1);
+		break;
+	case NETDEV_DOWN:
+		xenbus_address(dev, addr, 0);
+		list_del(&addr->next);
+		kfree(addr);
+		break;
+	}
+
+	return NOTIFY_DONE;
+}
+#endif
 
 /* ** Close down ** */
 

@@ -1266,9 +1399,13 @@
 
 static struct notifier_block notifier_inetdev = {
 	.notifier_call  = inetdev_notify,
-	.next           = NULL,
-	.priority       = 0
 };
+
+#ifdef CONFIG_IPV6
+static struct notifier_block notifier_inet6dev = {
+	.notifier_call  = inet6dev_notify,
+};
+#endif
 
 static int __init netif_init(void)
 {

@@ -1282,7 +1419,10 @@
 
 	IPRINTK("Initialising virtual ethernet driver.\n");
 
-	(void)register_inetaddr_notifier(&notifier_inetdev);
+	register_inetaddr_notifier(&notifier_inetdev);
+#ifdef CONFIG_IPV6
+	register_inet6addr_notifier(&notifier_inet6dev);
+#endif
 
 	return xenbus_register_frontend(&netfront);
 }

@@ -1292,6 +1432,9 @@
 static void netif_exit(void)
 {
 	unregister_inetaddr_notifier(&notifier_inetdev);
+#ifdef CONFIG_IPV6
+	unregister_inet6addr_notifier(&notifier_inet6dev);
+#endif
 
 	return xenbus_unregister_driver(&netfront);
 }