[NET]: Add macvlan driver

Add macvlan driver, which allows to create virtual ethernet devices
based on MAC address.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

MAINTAINERS

@@ -2330,6 +2330,12 @@ W:	http://linuxwireless.org/
 T:	git kernel.org:/pub/scm/linux/kernel/git/jbenc/mac80211.git
 S:	Maintained
 
+MACVLAN DRIVER
+P:	Patrick McHardy
+M:	kaber@trash.net
+L:	netdev@vger.kernel.org
+S:	Maintained
+
 MARVELL YUKON / SYSKONNECT DRIVER
 P:	Mirko Lindner
 M: 	mlindner@syskonnect.de

drivers/net/Kconfig

@@ -82,6 +82,16 @@ config BONDING
 	  To compile this driver as a module, choose M here: the module
 	  will be called bonding.
 
+config MACVLAN
+	tristate "MAC-VLAN support (EXPERIMENTAL)"
+	depends on EXPERIMENTAL
+	---help---
+	  This allows one to create virtual interfaces that map packets to
+	  or from specific MAC addresses to a particular interface.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called macvlan.
+
 config EQUALIZER
 	tristate "EQL (serial line load balancing) support"
 	---help---

drivers/net/Makefile

@@ -128,6 +128,7 @@ obj-$(CONFIG_SLHC) += slhc.o
 
 obj-$(CONFIG_DUMMY) += dummy.o
 obj-$(CONFIG_IFB) += ifb.o
+obj-$(CONFIG_MACVLAN) += macvlan.o
 obj-$(CONFIG_DE600) += de600.o
 obj-$(CONFIG_DE620) += de620.o
 obj-$(CONFIG_LANCE) += lance.o

drivers/net/macvlan.c

+/*
+ * Copyright (c) 2007 Patrick McHardy <kaber@trash.net>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * The code this is based on carried the following copyright notice:
+ * ---
+ * (C) Copyright 2001-2006
+ * Alex Zeffertt, Cambridge Broadband Ltd, ajz@cambridgebroadband.com
+ * Re-worked by Ben Greear <greearb@candelatech.com>
+ * ---
+ */
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/list.h>
+#include <linux/notifier.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/ethtool.h>
+#include <linux/if_arp.h>
+#include <linux/if_link.h>
+#include <linux/if_macvlan.h>
+#include <net/rtnetlink.h>
+
+#define MACVLAN_HASH_SIZE	(1 << BITS_PER_BYTE)
+
+struct macvlan_port {
+	struct net_device	*dev;
+	struct hlist_head	vlan_hash[MACVLAN_HASH_SIZE];
+	struct list_head	vlans;
+};
+
+struct macvlan_dev {
+	struct net_device	*dev;
+	struct list_head	list;
+	struct hlist_node	hlist;
+	struct macvlan_port	*port;
+	struct net_device	*lowerdev;
+};
+
+
+static struct macvlan_dev *macvlan_hash_lookup(const struct macvlan_port *port,
+					       const unsigned char *addr)
+{
+	struct macvlan_dev *vlan;
+	struct hlist_node *n;
+
+	hlist_for_each_entry_rcu(vlan, n, &port->vlan_hash[addr[5]], hlist) {
+		if (!compare_ether_addr(vlan->dev->dev_addr, addr))
+			return vlan;
+	}
+	return NULL;
+}
+
+static void macvlan_broadcast(struct sk_buff *skb,
+			      const struct macvlan_port *port)
+{
+	const struct ethhdr *eth = eth_hdr(skb);
+	const struct macvlan_dev *vlan;
+	struct hlist_node *n;
+	struct net_device *dev;
+	struct sk_buff *nskb;
+	unsigned int i;
+
+	for (i = 0; i < MACVLAN_HASH_SIZE; i++) {
+		hlist_for_each_entry_rcu(vlan, n, &port->vlan_hash[i], hlist) {
+			dev = vlan->dev;
+			if (unlikely(!(dev->flags & IFF_UP)))
+				continue;
+
+			nskb = skb_clone(skb, GFP_ATOMIC);
+			if (nskb == NULL) {
+				dev->stats.rx_errors++;
+				dev->stats.rx_dropped++;
+				continue;
+			}
+
+			dev->stats.rx_bytes += skb->len + ETH_HLEN;
+			dev->stats.rx_packets++;
+			dev->stats.multicast++;
+			dev->last_rx = jiffies;
+
+			nskb->dev = dev;
+			if (!compare_ether_addr(eth->h_dest, dev->broadcast))
+				nskb->pkt_type = PACKET_BROADCAST;
+			else
+				nskb->pkt_type = PACKET_MULTICAST;
+
+			netif_rx(nskb);
+		}
+	}
+}
+
+/* called under rcu_read_lock() from netif_receive_skb */
+static struct sk_buff *macvlan_handle_frame(struct sk_buff *skb)
+{
+	const struct ethhdr *eth = eth_hdr(skb);
+	const struct macvlan_port *port;
+	const struct macvlan_dev *vlan;
+	struct net_device *dev;
+
+	port = rcu_dereference(skb->dev->macvlan_port);
+	if (port == NULL)
+		return skb;
+
+	if (is_multicast_ether_addr(eth->h_dest)) {
+		macvlan_broadcast(skb, port);
+		return skb;
+	}
+
+	vlan = macvlan_hash_lookup(port, eth->h_dest);
+	if (vlan == NULL)
+		return skb;
+
+	dev = vlan->dev;
+	if (unlikely(!(dev->flags & IFF_UP))) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	skb = skb_share_check(skb, GFP_ATOMIC);
+	if (skb == NULL) {
+		dev->stats.rx_errors++;
+		dev->stats.rx_dropped++;
+		return NULL;
+	}
+
+	dev->stats.rx_bytes += skb->len + ETH_HLEN;
+	dev->stats.rx_packets++;
+	dev->last_rx = jiffies;
+
+	skb->dev = dev;
+	skb->pkt_type = PACKET_HOST;
+
+	netif_rx(skb);
+	return NULL;
+}
+
+static int macvlan_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	const struct macvlan_dev *vlan = netdev_priv(dev);
+	unsigned int len = skb->len;
+	int ret;
+
+	skb->dev = vlan->lowerdev;
+	ret = dev_queue_xmit(skb);
+
+	if (likely(ret == NET_XMIT_SUCCESS)) {
+		dev->stats.tx_packets++;
+		dev->stats.tx_bytes += len;
+	} else {
+		dev->stats.tx_errors++;
+		dev->stats.tx_aborted_errors++;
+	}
+	return NETDEV_TX_OK;
+}
+
+static int macvlan_hard_header(struct sk_buff *skb, struct net_device *dev,
+			       unsigned short type, void *daddr, void *saddr,
+			       unsigned len)
+{
+	const struct macvlan_dev *vlan = netdev_priv(dev);
+	struct net_device *lowerdev = vlan->lowerdev;
+
+	return lowerdev->hard_header(skb, lowerdev, type, daddr,
+				     saddr ? : dev->dev_addr, len);
+}
+
+static int macvlan_open(struct net_device *dev)
+{
+	struct macvlan_dev *vlan = netdev_priv(dev);
+	struct macvlan_port *port = vlan->port;
+	struct net_device *lowerdev = vlan->lowerdev;
+	int err;
+
+	err = dev_unicast_add(lowerdev, dev->dev_addr, ETH_ALEN);
+	if (err < 0)
+		return err;
+	if (dev->flags & IFF_ALLMULTI)
+		dev_set_allmulti(lowerdev, 1);
+
+	hlist_add_head_rcu(&vlan->hlist, &port->vlan_hash[dev->dev_addr[5]]);
+	return 0;
+}
+
+static int macvlan_stop(struct net_device *dev)
+{
+	struct macvlan_dev *vlan = netdev_priv(dev);
+	struct net_device *lowerdev = vlan->lowerdev;
+
+	dev_mc_unsync(lowerdev, dev);
+	if (dev->flags & IFF_ALLMULTI)
+		dev_set_allmulti(lowerdev, -1);
+
+	dev_unicast_delete(lowerdev, dev->dev_addr, ETH_ALEN);
+
+	hlist_del_rcu(&vlan->hlist);
+	synchronize_rcu();
+	return 0;
+}
+
+static void macvlan_change_rx_flags(struct net_device *dev, int change)
+{
+	struct macvlan_dev *vlan = netdev_priv(dev);
+	struct net_device *lowerdev = vlan->lowerdev;
+
+	if (change & IFF_ALLMULTI)
+		dev_set_allmulti(lowerdev, dev->flags & IFF_ALLMULTI ? 1 : -1);
+}
+
+static void macvlan_set_multicast_list(struct net_device *dev)
+{
+	struct macvlan_dev *vlan = netdev_priv(dev);
+
+	dev_mc_sync(vlan->lowerdev, dev);
+}
+
+static int macvlan_change_mtu(struct net_device *dev, int new_mtu)
+{
+	struct macvlan_dev *vlan = netdev_priv(dev);
+
+	if (new_mtu < 68 || vlan->lowerdev->mtu < new_mtu)
+		return -EINVAL;
+	dev->mtu = new_mtu;
+	return 0;
+}
+
+/*
+ * macvlan network devices have devices nesting below it and are a special
+ * "super class" of normal network devices; split their locks off into a
+ * separate class since they always nest.
+ */
+static struct lock_class_key macvlan_netdev_xmit_lock_key;
+
+#define MACVLAN_FEATURES \
+	(NETIF_F_SG | NETIF_F_ALL_CSUM | NETIF_F_HIGHDMA | NETIF_F_FRAGLIST | \
+	 NETIF_F_GSO | NETIF_F_TSO | NETIF_F_UFO | NETIF_F_GSO_ROBUST | \
+	 NETIF_F_TSO_ECN | NETIF_F_TSO6)
+
+#define MACVLAN_STATE_MASK \
+	((1<<__LINK_STATE_NOCARRIER) | (1<<__LINK_STATE_DORMANT))
+
+static int macvlan_init(struct net_device *dev)
+{
+	struct macvlan_dev *vlan = netdev_priv(dev);
+	const struct net_device *lowerdev = vlan->lowerdev;
+
+	dev->state		= (dev->state & ~MACVLAN_STATE_MASK) |
+				  (lowerdev->state & MACVLAN_STATE_MASK);
+	dev->features 		= lowerdev->features & MACVLAN_FEATURES;
+	dev->iflink		= lowerdev->ifindex;
+
+	lockdep_set_class(&dev->_xmit_lock, &macvlan_netdev_xmit_lock_key);
+	return 0;
+}
+
+static void macvlan_ethtool_get_drvinfo(struct net_device *dev,
+					struct ethtool_drvinfo *drvinfo)
+{
+	snprintf(drvinfo->driver, 32, "macvlan");
+	snprintf(drvinfo->version, 32, "0.1");
+}
+
+static u32 macvlan_ethtool_get_rx_csum(struct net_device *dev)
+{
+	const struct macvlan_dev *vlan = netdev_priv(dev);
+	struct net_device *lowerdev = vlan->lowerdev;
+
+	if (lowerdev->ethtool_ops->get_rx_csum == NULL)
+		return 0;
+	return lowerdev->ethtool_ops->get_rx_csum(lowerdev);
+}
+
+static const struct ethtool_ops macvlan_ethtool_ops = {
+	.get_link		= ethtool_op_get_link,
+	.get_rx_csum		= macvlan_ethtool_get_rx_csum,
+	.get_tx_csum		= ethtool_op_get_tx_csum,
+	.get_tso		= ethtool_op_get_tso,
+	.get_ufo		= ethtool_op_get_ufo,
+	.get_sg			= ethtool_op_get_sg,
+	.get_drvinfo		= macvlan_ethtool_get_drvinfo,
+};
+
+static void macvlan_setup(struct net_device *dev)
+{
+	ether_setup(dev);
+
+	dev->init		= macvlan_init;
+	dev->open		= macvlan_open;
+	dev->stop		= macvlan_stop;
+	dev->change_mtu		= macvlan_change_mtu;
+	dev->change_rx_flags	= macvlan_change_rx_flags;
+	dev->set_multicast_list	= macvlan_set_multicast_list;
+	dev->hard_header	= macvlan_hard_header;
+	dev->hard_start_xmit	= macvlan_hard_start_xmit;
+	dev->destructor		= free_netdev;
+	dev->ethtool_ops	= &macvlan_ethtool_ops;
+	dev->tx_queue_len	= 0;
+}
+
+static int macvlan_port_create(struct net_device *dev)
+{
+	struct macvlan_port *port;
+	unsigned int i;
+
+	if (dev->type != ARPHRD_ETHER || dev->flags & IFF_LOOPBACK)
+		return -EINVAL;
+
+	port = kzalloc(sizeof(*port), GFP_KERNEL);
+	if (port == NULL)
+		return -ENOMEM;
+
+	port->dev = dev;
+	INIT_LIST_HEAD(&port->vlans);
+	for (i = 0; i < MACVLAN_HASH_SIZE; i++)
+		INIT_HLIST_HEAD(&port->vlan_hash[i]);
+	rcu_assign_pointer(dev->macvlan_port, port);
+	return 0;
+}
+
+static void macvlan_port_destroy(struct net_device *dev)
+{
+	struct macvlan_port *port = dev->macvlan_port;
+
+	rcu_assign_pointer(dev->macvlan_port, NULL);
+	synchronize_rcu();
+	kfree(port);
+}
+
+static void macvlan_transfer_operstate(struct net_device *dev)
+{
+	struct macvlan_dev *vlan = netdev_priv(dev);
+	const struct net_device *lowerdev = vlan->lowerdev;
+
+	if (lowerdev->operstate == IF_OPER_DORMANT)
+		netif_dormant_on(dev);
+	else
+		netif_dormant_off(dev);
+
+	if (netif_carrier_ok(lowerdev)) {
+		if (!netif_carrier_ok(dev))
+			netif_carrier_on(dev);
+	} else {
+		if (netif_carrier_ok(lowerdev))
+			netif_carrier_off(dev);
+	}
+}
+
+static int macvlan_validate(struct nlattr *tb[], struct nlattr *data[])
+{
+	if (tb[IFLA_ADDRESS]) {
+		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
+			return -EINVAL;
+		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
+			return -EADDRNOTAVAIL;
+	}
+	return 0;
+}
+
+static int macvlan_newlink(struct net_device *dev,
+			   struct nlattr *tb[], struct nlattr *data[])
+{
+	struct macvlan_dev *vlan = netdev_priv(dev);
+	struct macvlan_port *port;
+	struct net_device *lowerdev;
+	int err;
+
+	if (!tb[IFLA_LINK])
+		return -EINVAL;
+
+	lowerdev = __dev_get_by_index(nla_get_u32(tb[IFLA_LINK]));
+	if (lowerdev == NULL)
+		return -ENODEV;
+
+	if (!tb[IFLA_MTU])
+		dev->mtu = lowerdev->mtu;
+	else if (dev->mtu > lowerdev->mtu)
+		return -EINVAL;
+
+	if (!tb[IFLA_ADDRESS])
+		random_ether_addr(dev->dev_addr);
+
+	if (lowerdev->macvlan_port == NULL) {
+		err = macvlan_port_create(lowerdev);
+		if (err < 0)
+			return err;
+	}
+	port = lowerdev->macvlan_port;
+
+	vlan->lowerdev = lowerdev;
+	vlan->dev      = dev;
+	vlan->port     = port;
+
+	err = register_netdevice(dev);
+	if (err < 0)
+		return err;
+
+	list_add_tail(&vlan->list, &port->vlans);
+	macvlan_transfer_operstate(dev);
+	return 0;
+}
+
+static void macvlan_dellink(struct net_device *dev)
+{
+	struct macvlan_dev *vlan = netdev_priv(dev);
+	struct macvlan_port *port = vlan->port;
+
+	list_del(&vlan->list);
+	unregister_netdevice(dev);
+
+	if (list_empty(&port->vlans))
+		macvlan_port_destroy(dev);
+}
+
+static struct rtnl_link_ops macvlan_link_ops __read_mostly = {
+	.kind		= "macvlan",
+	.priv_size	= sizeof(struct macvlan_dev),
+	.setup		= macvlan_setup,
+	.validate	= macvlan_validate,
+	.newlink	= macvlan_newlink,
+	.dellink	= macvlan_dellink,
+};
+
+static int macvlan_device_event(struct notifier_block *unused,
+				unsigned long event, void *ptr)
+{
+	struct net_device *dev = ptr;
+	struct macvlan_dev *vlan, *next;
+	struct macvlan_port *port;
+
+	port = dev->macvlan_port;
+	if (port == NULL)
+		return NOTIFY_DONE;
+
+	switch (event) {
+	case NETDEV_CHANGE:
+		list_for_each_entry(vlan, &port->vlans, list)
+			macvlan_transfer_operstate(vlan->dev);
+		break;
+	case NETDEV_FEAT_CHANGE:
+		list_for_each_entry(vlan, &port->vlans, list) {
+			vlan->dev->features = dev->features & MACVLAN_FEATURES;
+			netdev_features_change(vlan->dev);
+		}
+		break;
+	case NETDEV_UNREGISTER:
+		list_for_each_entry_safe(vlan, next, &port->vlans, list)
+			macvlan_dellink(vlan->dev);
+		break;
+	}
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block macvlan_notifier_block __read_mostly = {
+	.notifier_call	= macvlan_device_event,
+};
+
+static int __init macvlan_init_module(void)
+{
+	int err;
+
+	register_netdevice_notifier(&macvlan_notifier_block);
+	macvlan_handle_frame_hook = macvlan_handle_frame;
+
+	err = rtnl_link_register(&macvlan_link_ops);
+	if (err < 0)
+		goto err1;
+	return 0;
+err1:
+	macvlan_handle_frame_hook = macvlan_handle_frame;
+	unregister_netdevice_notifier(&macvlan_notifier_block);
+	return err;
+}
+
+static void __exit macvlan_cleanup_module(void)
+{
+	rtnl_link_unregister(&macvlan_link_ops);
+	macvlan_handle_frame_hook = NULL;
+	unregister_netdevice_notifier(&macvlan_notifier_block);
+}
+
+module_init(macvlan_init_module);
+module_exit(macvlan_cleanup_module);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
+MODULE_DESCRIPTION("Driver for MAC address based VLANs");
+MODULE_ALIAS_RTNL_LINK("macvlan");

include/linux/if_macvlan.h

+#ifndef _LINUX_IF_MACVLAN_H
+#define _LINUX_IF_MACVLAN_H
+
+#ifdef __KERNEL__
+
+extern struct sk_buff *(*macvlan_handle_frame_hook)(struct sk_buff *);
+
+#endif /* __KERNEL__ */
+#endif /* _LINUX_IF_MACVLAN_H */

include/linux/netdevice.h

@@ -564,6 +564,8 @@ struct net_device
 
 	/* bridge stuff */
 	struct net_bridge_port	*br_port;
+	/* macvlan */
+	struct macvlan_port	*macvlan_port;
 
 	/* class/net/name entry */
 	struct device		dev;

net/core/dev.c

@@ -98,6 +98,7 @@
 #include <linux/seq_file.h>
 #include <linux/stat.h>
 #include <linux/if_bridge.h>
+#include <linux/if_macvlan.h>
 #include <net/dst.h>
 #include <net/pkt_sched.h>
 #include <net/checksum.h>
@@ -1813,6 +1814,28 @@ static inline struct sk_buff *handle_bridge(struct sk_buff *skb,
 #define handle_bridge(skb, pt_prev, ret, orig_dev)	(skb)
 #endif
 
+#if defined(CONFIG_MACVLAN) || defined(CONFIG_MACVLAN_MODULE)
+struct sk_buff *(*macvlan_handle_frame_hook)(struct sk_buff *skb) __read_mostly;
+EXPORT_SYMBOL_GPL(macvlan_handle_frame_hook);
+
+static inline struct sk_buff *handle_macvlan(struct sk_buff *skb,
+					     struct packet_type **pt_prev,
+					     int *ret,
+					     struct net_device *orig_dev)
+{
+	if (skb->dev->macvlan_port == NULL)
+		return skb;
+
+	if (*pt_prev) {
+		*ret = deliver_skb(skb, *pt_prev, orig_dev);
+		*pt_prev = NULL;
+	}
+	return macvlan_handle_frame_hook(skb);
+}
+#else
+#define handle_macvlan(skb, pt_prev, ret, orig_dev)	(skb)
+#endif
+
 #ifdef CONFIG_NET_CLS_ACT
 /* TODO: Maybe we should just force sch_ingress to be compiled in
  * when CONFIG_NET_CLS_ACT is? otherwise some useless instructions
@@ -1918,6 +1941,9 @@ int netif_receive_skb(struct sk_buff *skb)
 #endif
 
 	skb = handle_bridge(skb, &pt_prev, &ret, orig_dev);
+	if (!skb)
+		goto out;
+	skb = handle_macvlan(skb, &pt_prev, &ret, orig_dev);
 	if (!skb)
 		goto out;