[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>

3 files changed, 507 insertions, 0 deletions

diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index ba314adf68b8..d17d64eb7065 100644
--- a/drivers/net/Kconfig
+++ b/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---
diff --git a/drivers/net/Makefile b/drivers/net/Makefile
index a2241e6e1457..c26b8674213c 100644
--- a/drivers/net/Makefile
+++ b/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
diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
new file mode 100644
index 000000000000..dc74d006e01f
--- /dev/null
+++ b/drivers/net/macvlan.c
@@ -0,0 +1,496 @@
+/*
+ * 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");