Interface registration

2 files changed, 191 insertions, 8 deletions

diff --git a/fastd.c b/fastd.c
index 6eefd72..9c3894c 100644
--- a/fastd.c
+++ b/fastd.c
@@ -43,31 +43,71 @@
 
 
 #include <linux/module.h>
+#include <linux/etherdevice.h>
+#include <linux/ethtool.h>
 #include <linux/errno.h>
 #include <linux/init.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
 #include <linux/kernel.h>
+#include <linux/netdevice.h>
+#include <linux/rculist.h>
 #include <net/genetlink.h>
+#include <net/route.h>
 
 #include "fastd.h"
 
 
+static LIST_HEAD(fastd_list);
+static struct workqueue_struct *fastd_workqueue;
+
+
+struct fastd_struct {
+	struct list_head	list;
+
+	struct net_device	*dev;
+	u32			owner;
+
+	u16			mode;
+	unsigned long		flags;
+
+	struct work_struct	destroy_work;
+};
+
+
 static struct genl_family fastd_nl_family = {
 	.id		= GENL_ID_GENERATE,
+	.hdrsize	= 0,
 	.name		= DRV_NAME,
 	.version	= 1,
-	.hdrsize	= 0,
 	.maxattr	= FASTD_A_MAX,
+	.netnsok	= true,
+	.parallel_ops	= true,
 };
 
 
-static int fastd_nl_event(struct notifier_block *this,
-				 unsigned long event, void *ptr)
+static int fastd_nl_event(struct notifier_block *nb,
+			  unsigned long event, void *ptr)
 {
 	struct netlink_notify *n = ptr;
+	struct fastd_struct *entry;
 
 	if (event != NETLINK_URELEASE || n->protocol != NETLINK_GENERIC)
 		return NOTIFY_DONE;
 
+	rcu_read_lock();
+
+	list_for_each_entry_rcu(entry, &fastd_list, list) {
+		if (entry->owner == n->portid) {
+			/* allow registration of a new interface for this portid */
+			ACCESS_ONCE(entry->owner) = 0;
+
+			queue_work(fastd_workqueue, &entry->destroy_work);
+		}
+	}
+
+	rcu_read_unlock();
+
 	return NOTIFY_DONE;
 }
 
@@ -76,16 +116,146 @@ static struct notifier_block nl_notifier = {
 };
 
 
+static const struct net_device_ops fastd_netdev_ops_eth = {
+};
+
+static const struct net_device_ops fastd_netdev_ops_ip = {
+};
+
+
+static void fastd_ethtool_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
+{
+	struct fastd_struct *fastd = netdev_priv(dev);
+
+	strcpy(info->driver, DRV_NAME);
+	strcpy(info->version, DRV_VERSION);
+	strcpy(info->fw_version, "N/A");
+
+	switch (fastd->mode) {
+	case FASTD_MODE_ETH:
+		strcpy(info->bus_info, "ethernet");
+		break;
+	case FASTD_MODE_IP:
+		strcpy(info->bus_info, "ip");
+	}
+}
+
+static u32 fastd_ethtool_get_link(struct net_device *dev)
+{
+	return 1;
+}
+
+
+static const struct ethtool_ops fastd_ethtool_ops = {
+	.get_drvinfo	= fastd_ethtool_get_drvinfo,
+	.get_link	= fastd_ethtool_get_link,
+};
+
+
+static void fastd_netdev_setup(struct net_device *dev)
+{
+	dev->ethtool_ops = &fastd_ethtool_ops;
+	dev->destructor = free_netdev;
+}
+
+static void fastd_netdev_init(struct net_device *dev)
+{
+	struct fastd_struct *fastd = netdev_priv(dev);
+
+	switch (fastd->mode) {
+	case FASTD_MODE_ETH:
+		dev->netdev_ops = &fastd_netdev_ops_eth;
+
+		eth_hw_addr_random(dev);
+		ether_setup(dev);
+
+		dev->hard_header_len = ETH_HLEN + sizeof(struct ipv6hdr) + sizeof(struct udphdr) + ETH_HLEN;
+
+		break;
+
+	case FASTD_MODE_IP:
+		dev->netdev_ops = &fastd_netdev_ops_eth;
+
+		dev->addr_len = 0;
+		dev->hard_header_len = ETH_HLEN + sizeof(struct ipv6hdr) + sizeof(struct udphdr);
+		dev->mtu = 1500;
+
+		dev->type = ARPHRD_NONE;
+		dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
+	}
+}
+
+static void fastd_destroy_work(struct work_struct *work)
+{
+	struct fastd_struct *fastd = container_of(work, struct fastd_struct,
+						  destroy_work);
+
+	rtnl_lock();
+
+	list_del_rcu(&fastd->list);
+	unregister_netdevice(fastd->dev);
+
+	rtnl_unlock();
+}
+
 static int fastd_cmd_create(struct sk_buff *skb, struct genl_info *info)
 {
-	if (!capable(CAP_NET_ADMIN))
+	struct net *net = genl_info_net(info);
+	struct net_device *dev;
+	struct fastd_struct *fastd;
+	u16 mode;
+	const char *name = "fastd%d";
+	int err;
+
+	if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 		return -EPERM;
 
-	return -EINVAL;
+	if (!info->attrs[FASTD_A_MODE])
+		return -EINVAL;
+
+	mode = nla_get_u16(info->attrs[FASTD_A_MODE]);
+	if (mode != FASTD_MODE_ETH && mode != FASTD_MODE_IP)
+		return -EINVAL;
+
+	if (info->attrs[FASTD_A_IFNAME])
+		name = nla_data(info->attrs[FASTD_A_IFNAME]);
+
+	dev = alloc_netdev(sizeof(struct fastd_struct), name, fastd_netdev_setup);
+	if (!dev)
+		return -ENOMEM;
+
+	dev_net_set(dev, net);
+
+	fastd = netdev_priv(dev);
+	fastd->dev = dev;
+	fastd->owner = info->snd_portid;
+	fastd->mode = mode;
+	INIT_WORK(&fastd->destroy_work, fastd_destroy_work);
+
+	fastd_netdev_init(dev);
+
+	rtnl_lock();
+	err = register_netdevice(dev);
+	if (err < 0) {
+		rtnl_unlock();
+		goto err_free_dev;
+	}
+
+	list_add_tail_rcu(&fastd->list, &fastd_list);
+
+	rtnl_unlock();
+
+	return 0;
+
+err_free_dev:
+	free_netdev(dev);
+	return err;
 }
 
 
 static struct nla_policy fastd_nl_policy[__FASTD_A_MAX] = {
+	[FASTD_A_IFNAME]	= { .type = NLA_NUL_STRING, .len = IFNAMSIZ - 1 },
+	[FASTD_A_MODE]		= { .type = NLA_U16 },
 };
 
 static struct genl_ops fastd_nl_ops[] = {
@@ -101,9 +271,14 @@ static int __init fastd_init(void)
 {
 	int ret = 0;
 
+	fastd_workqueue = alloc_workqueue("fastd", 0, 0);
+	if (!fastd_workqueue)
+		return -ENOMEM;
+
 	netlink_register_notifier(&nl_notifier);
 
-	ret = genl_register_family_with_ops(&fastd_nl_family, fastd_nl_ops, ARRAY_SIZE(fastd_nl_ops));
+	ret = genl_register_family_with_ops(&fastd_nl_family, fastd_nl_ops,
+					    ARRAY_SIZE(fastd_nl_ops));
 	if (ret)
 		goto unregister_notifier;
 
@@ -111,8 +286,9 @@ static int __init fastd_init(void)
 
 	return 0;
 
-  unregister_notifier:
+unregister_notifier:
 	netlink_unregister_notifier(&nl_notifier);
+	destroy_workqueue(fastd_workqueue);
 
 	return ret;
 }
@@ -121,6 +297,7 @@ static void fastd_cleanup(void)
 {
 	genl_unregister_family(&fastd_nl_family);
 	netlink_unregister_notifier(&nl_notifier);
+	destroy_workqueue(fastd_workqueue);
 }
 
 
@@ -129,4 +306,4 @@ module_exit(fastd_cleanup);
 MODULE_DESCRIPTION(DRV_DESCRIPTION);
 MODULE_AUTHOR(DRV_COPYRIGHT);
 MODULE_LICENSE("Dual BSD/GPL");
-MODULE_ALIAS_GENL_FAMILY("fastd");
+MODULE_ALIAS_GENL_FAMILY(DRV_NAME);
diff --git a/fastd.h b/fastd.h
index 0e110a9..026846a 100644
--- a/fastd.h
+++ b/fastd.h
@@ -39,6 +39,10 @@
 #ifndef __LINUX_FASTD_H
 #define __LINUX_FASTD_H
 
+#define FASTD_MODE_ETH	0x0001
+#define FASTD_MODE_IP	0x0002
+
+
 enum {
 	FASTD_CMD_UNSPEC,
 	FASTD_CMD_CREATE,
@@ -47,6 +51,8 @@ enum {
 
 enum {
 	FASTD_A_UNSPEC,
+	FASTD_A_IFNAME,
+	FASTD_A_MODE,
 	__FASTD_A_MAX
 };