linux/drivers/net/macvlan.c
Eric Dumazet fccaf71011 macvlan: Precise RX stats accounting
With multi queue devices, its possible that several cpus call
macvlan RX routines simultaneously for the same macvlan device.

We update RX stats counter without any locking, so we can
get slightly wrong counters.

One possible fix is to use percpu counters, to get precise
accounting and also get guarantee of no cache line ping pongs
between cpus.

Note: this adds 16 bytes (32 bytes on 64bit arches) of percpu
data per macvlan device.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-11-17 23:51:57 -08:00

701 lines
17 KiB
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_rx_stats - MACVLAN percpu rx stats
* @rx_packets: number of received packets
* @rx_bytes: number of received bytes
* @multicast: number of received multicast packets
* @rx_errors: number of errors
*/
struct macvlan_rx_stats {
unsigned long rx_packets;
unsigned long rx_bytes;
unsigned long multicast;
unsigned long rx_errors;
};
struct macvlan_dev {
struct net_device *dev;
struct list_head list;
struct hlist_node hlist;
struct macvlan_port *port;
struct net_device *lowerdev;
struct macvlan_rx_stats *rx_stats;
};
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_64bits(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 (!compare_ether_addr_64bits(port->dev->dev_addr, addr))
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;
struct macvlan_rx_stats *rx_stats;
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;
rx_stats = per_cpu_ptr(vlan->rx_stats, smp_processor_id());
nskb = skb_clone(skb, GFP_ATOMIC);
if (nskb == NULL) {
rx_stats->rx_errors++;
continue;
}
rx_stats->rx_bytes += skb->len + ETH_HLEN;
rx_stats->rx_packets++;
rx_stats->multicast++;
nskb->dev = dev;
if (!compare_ether_addr_64bits(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;
struct macvlan_rx_stats *rx_stats;
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;
}
rx_stats = per_cpu_ptr(vlan->rx_stats, smp_processor_id());
skb = skb_share_check(skb, GFP_ATOMIC);
if (skb == NULL) {
rx_stats->rx_errors++;
return NULL;
}
rx_stats->rx_bytes += skb->len + ETH_HLEN;
rx_stats->rx_packets++;
skb->dev = dev;
skb->pkt_type = PACKET_HOST;
netif_rx(skb);
return NULL;
}
static netdev_tx_t macvlan_start_xmit(struct sk_buff *skb,
struct net_device *dev)
{
int i = skb_get_queue_mapping(skb);
struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
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)) {
txq->tx_packets++;
txq->tx_bytes += len;
} else
txq->tx_dropped++;
return ret;
}
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);
vlan->rx_stats = alloc_percpu(struct macvlan_rx_stats);
if (!vlan->rx_stats)
return -ENOMEM;
return 0;
}
static void macvlan_uninit(struct net_device *dev)
{
struct macvlan_dev *vlan = netdev_priv(dev);
free_percpu(vlan->rx_stats);
}
static struct net_device_stats *macvlan_dev_get_stats(struct net_device *dev)
{
struct net_device_stats *stats = &dev->stats;
struct macvlan_dev *vlan = netdev_priv(dev);
dev_txq_stats_fold(dev, stats);
if (vlan->rx_stats) {
struct macvlan_rx_stats *p, rx = {0};
int i;
for_each_possible_cpu(i) {
p = per_cpu_ptr(vlan->rx_stats, i);
rx.rx_packets += p->rx_packets;
rx.rx_bytes += p->rx_bytes;
rx.rx_errors += p->rx_errors;
rx.multicast += p->multicast;
}
stats->rx_packets = rx.rx_packets;
stats->rx_bytes = rx.rx_bytes;
stats->rx_errors = rx.rx_errors;
stats->rx_dropped = rx.rx_errors;
stats->multicast = rx.multicast;
}
return stats;
}
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_uninit = macvlan_uninit,
.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_get_stats = macvlan_dev_get_stats,
.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_get_tx_queues(struct net *net,
struct nlattr *tb[],
unsigned int *num_tx_queues,
unsigned int *real_num_tx_queues)
{
struct net_device *real_dev;
if (!tb[IFLA_LINK])
return -EINVAL;
real_dev = __dev_get_by_index(net, nla_get_u32(tb[IFLA_LINK]));
if (!real_dev)
return -ENODEV;
*num_tx_queues = real_dev->num_tx_queues;
*real_num_tx_queues = real_dev->real_num_tx_queues;
return 0;
}
static int macvlan_newlink(struct net *src_net, 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(src_net, 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 list_head *head)
{
struct macvlan_dev *vlan = netdev_priv(dev);
struct macvlan_port *port = vlan->port;
list_del(&vlan->list);
unregister_netdevice_queue(dev, head);
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),
.get_tx_queues = macvlan_get_tx_queues,
.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, NULL);
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");