Merge commit 'linux-pnfs/nfs41-for-2.6.31' into nfsv41-for-2.6.31

[deliverable/linux.git] / 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/rculist.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_hash_add(struct macvlan_dev *vlan)
{
        struct macvlan_port *port = vlan->port;
        const unsigned char *addr = vlan->dev->dev_addr;

        hlist_add_head_rcu(&vlan->hlist, &port->vlan_hash[addr[5]]);
}

static void macvlan_hash_del(struct macvlan_dev *vlan)
{
        hlist_del_rcu(&vlan->hlist);
        synchronize_rcu();
}

static void macvlan_hash_change_addr(struct macvlan_dev *vlan,
                                        const unsigned char *addr)
{
        macvlan_hash_del(vlan);
        /* Now that we are unhashed it is safe to change the device
         * address without confusing packet delivery.
         */
        memcpy(vlan->dev->dev_addr, addr, ETH_ALEN);
        macvlan_hash_add(vlan);
}

static int macvlan_addr_busy(const struct macvlan_port *port,
                                const unsigned char *addr)
{
        /* Test to see if the specified multicast address is
         * currently in use by the underlying device or
         * another macvlan.
         */
        if (memcmp(port->dev->dev_addr, addr, ETH_ALEN) == 0)
                return 1;

        if (macvlan_hash_lookup(port, addr))
                return 1;

        return 0;
}

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;

        if (skb->protocol == htons(ETH_P_PAUSE))
                return;

        for (i = 0; i < MACVLAN_HASH_SIZE; i++) {
                hlist_for_each_entry_rcu(vlan, n, &port->vlan_hash[i], hlist) {
                        dev = vlan->dev;

                        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++;

                        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++;

        skb->dev = dev;
        skb->pkt_type = PACKET_HOST;

        netif_rx(skb);
        return NULL;
}

static int macvlan_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, const void *daddr,
                               const void *saddr, unsigned len)
{
        const struct macvlan_dev *vlan = netdev_priv(dev);
        struct net_device *lowerdev = vlan->lowerdev;

        return dev_hard_header(skb, lowerdev, type, daddr,
                               saddr ? : dev->dev_addr, len);
}

static const struct header_ops macvlan_hard_header_ops = {
        .create         = macvlan_hard_header,
        .rebuild        = eth_rebuild_header,
        .parse          = eth_header_parse,
        .cache          = eth_header_cache,
        .cache_update   = eth_header_cache_update,
};

static int macvlan_open(struct net_device *dev)
{
        struct macvlan_dev *vlan = netdev_priv(dev);
        struct net_device *lowerdev = vlan->lowerdev;
        int err;

        err = -EBUSY;
        if (macvlan_addr_busy(vlan->port, dev->dev_addr))
                goto out;

        err = dev_unicast_add(lowerdev, dev->dev_addr);
        if (err < 0)
                goto out;
        if (dev->flags & IFF_ALLMULTI) {
                err = dev_set_allmulti(lowerdev, 1);
                if (err < 0)
                        goto del_unicast;
        }
        macvlan_hash_add(vlan);
        return 0;

del_unicast:
        dev_unicast_delete(lowerdev, dev->dev_addr);
out:
        return err;
}

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);

        macvlan_hash_del(vlan);
        return 0;
}

static int macvlan_set_mac_address(struct net_device *dev, void *p)
{
        struct macvlan_dev *vlan = netdev_priv(dev);
        struct net_device *lowerdev = vlan->lowerdev;
        struct sockaddr *addr = p;
        int err;

        if (!is_valid_ether_addr(addr->sa_data))
                return -EADDRNOTAVAIL;

        if (!(dev->flags & IFF_UP)) {
                /* Just copy in the new address */
                memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
        } else {
                /* Rehash and update the device filters */
                if (macvlan_addr_busy(vlan->port, addr->sa_data))
                        return -EBUSY;

                err = dev_unicast_add(lowerdev, addr->sa_data);
                if (err)
                        return err;

                dev_unicast_delete(lowerdev, dev->dev_addr);

                macvlan_hash_change_addr(vlan, addr->sa_data);
        }
        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;
static struct lock_class_key macvlan_netdev_addr_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 void macvlan_set_lockdep_class_one(struct net_device *dev,
                                          struct netdev_queue *txq,
                                          void *_unused)
{
        lockdep_set_class(&txq->_xmit_lock,
                          &macvlan_netdev_xmit_lock_key);
}

static void macvlan_set_lockdep_class(struct net_device *dev)
{
        lockdep_set_class(&dev->addr_list_lock,
                          &macvlan_netdev_addr_lock_key);
        netdev_for_each_tx_queue(dev, macvlan_set_lockdep_class_one, NULL);
}

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;
        dev->hard_header_len    = lowerdev->hard_header_len;

        macvlan_set_lockdep_class(dev);

        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);
        return dev_ethtool_get_rx_csum(vlan->lowerdev);
}

static int macvlan_ethtool_get_settings(struct net_device *dev,
                                        struct ethtool_cmd *cmd)
{
        const struct macvlan_dev *vlan = netdev_priv(dev);
        return dev_ethtool_get_settings(vlan->lowerdev, cmd);
}

static u32 macvlan_ethtool_get_flags(struct net_device *dev)
{
        const struct macvlan_dev *vlan = netdev_priv(dev);
        return dev_ethtool_get_flags(vlan->lowerdev);
}

static const struct ethtool_ops macvlan_ethtool_ops = {
        .get_link               = ethtool_op_get_link,
        .get_settings           = macvlan_ethtool_get_settings,
        .get_rx_csum            = macvlan_ethtool_get_rx_csum,
        .get_drvinfo            = macvlan_ethtool_get_drvinfo,
        .get_flags              = macvlan_ethtool_get_flags,
};

static const struct net_device_ops macvlan_netdev_ops = {
        .ndo_init               = macvlan_init,
        .ndo_open               = macvlan_open,
        .ndo_stop               = macvlan_stop,
        .ndo_start_xmit         = macvlan_start_xmit,
        .ndo_change_mtu         = macvlan_change_mtu,
        .ndo_change_rx_flags    = macvlan_change_rx_flags,
        .ndo_set_mac_address    = macvlan_set_mac_address,
        .ndo_set_multicast_list = macvlan_set_multicast_list,
        .ndo_validate_addr      = eth_validate_addr,
};

static void macvlan_setup(struct net_device *dev)
{
        ether_setup(dev);

        dev->priv_flags        &= ~IFF_XMIT_DST_RELEASE;
        dev->netdev_ops         = &macvlan_netdev_ops;
        dev->destructor         = free_netdev;
        dev->header_ops         = &macvlan_hard_header_ops,
        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(dev))
                        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(dev_net(dev), nla_get_u32(tb[IFLA_LINK]));
        if (lowerdev == NULL)
                return -ENODEV;

        /* When creating macvlans on top of other macvlans - use
         * the real device as the lowerdev.
         */
        if (lowerdev->rtnl_link_ops == dev->rtnl_link_ops) {
                struct macvlan_dev *lowervlan = netdev_priv(lowerdev);
                lowerdev = lowervlan->lowerdev;
        }

        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(port->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 = NULL;
        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");