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path: root/drivers/net/veth.c
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Diffstat (limited to 'drivers/net/veth.c')
-rw-r--r--drivers/net/veth.c177
1 files changed, 93 insertions, 84 deletions
diff --git a/drivers/net/veth.c b/drivers/net/veth.c
index 95814d9..07a4af0 100644
--- a/drivers/net/veth.c
+++ b/drivers/net/veth.c
@@ -25,18 +25,15 @@
#define MIN_MTU 68 /* Min L3 MTU */
#define MAX_MTU 65535 /* Max L3 MTU (arbitrary) */
-struct veth_net_stats {
- u64 rx_packets;
- u64 rx_bytes;
- u64 tx_packets;
- u64 tx_bytes;
- u64 rx_dropped;
+struct pcpu_vstats {
+ u64 packets;
+ u64 bytes;
struct u64_stats_sync syncp;
};
struct veth_priv {
- struct net_device *peer;
- struct veth_net_stats __percpu *stats;
+ struct net_device __rcu *peer;
+ atomic64_t dropped;
};
/*
@@ -92,10 +89,10 @@ static int veth_get_sset_count(struct net_device *dev, int sset)
static void veth_get_ethtool_stats(struct net_device *dev,
struct ethtool_stats *stats, u64 *data)
{
- struct veth_priv *priv;
+ struct veth_priv *priv = netdev_priv(dev);
+ struct net_device *peer = rtnl_dereference(priv->peer);
- priv = netdev_priv(dev);
- data[0] = priv->peer->ifindex;
+ data[0] = peer ? peer->ifindex : 0;
}
static const struct ethtool_ops veth_ethtool_ops = {
@@ -107,50 +104,37 @@ static const struct ethtool_ops veth_ethtool_ops = {
.get_ethtool_stats = veth_get_ethtool_stats,
};
-/*
- * xmit
- */
-
static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
{
- struct net_device *rcv = NULL;
- struct veth_priv *priv, *rcv_priv;
- struct veth_net_stats *stats, *rcv_stats;
- int length;
-
- priv = netdev_priv(dev);
- rcv = priv->peer;
- rcv_priv = netdev_priv(rcv);
-
- stats = this_cpu_ptr(priv->stats);
- rcv_stats = this_cpu_ptr(rcv_priv->stats);
-
+ struct veth_priv *priv = netdev_priv(dev);
+ struct net_device *rcv;
+ int length = skb->len;
+
+ rcu_read_lock();
+ rcv = rcu_dereference(priv->peer);
+ if (unlikely(!rcv)) {
+ kfree_skb(skb);
+ goto drop;
+ }
/* don't change ip_summed == CHECKSUM_PARTIAL, as that
- will cause bad checksum on forwarded packets */
+ * will cause bad checksum on forwarded packets
+ */
if (skb->ip_summed == CHECKSUM_NONE &&
rcv->features & NETIF_F_RXCSUM)
skb->ip_summed = CHECKSUM_UNNECESSARY;
- length = skb->len;
- if (dev_forward_skb(rcv, skb) != NET_RX_SUCCESS)
- goto rx_drop;
+ if (likely(dev_forward_skb(rcv, skb) == NET_RX_SUCCESS)) {
+ struct pcpu_vstats *stats = this_cpu_ptr(dev->vstats);
- u64_stats_update_begin(&stats->syncp);
- stats->tx_bytes += length;
- stats->tx_packets++;
- u64_stats_update_end(&stats->syncp);
-
- u64_stats_update_begin(&rcv_stats->syncp);
- rcv_stats->rx_bytes += length;
- rcv_stats->rx_packets++;
- u64_stats_update_end(&rcv_stats->syncp);
-
- return NETDEV_TX_OK;
-
-rx_drop:
- u64_stats_update_begin(&rcv_stats->syncp);
- rcv_stats->rx_dropped++;
- u64_stats_update_end(&rcv_stats->syncp);
+ u64_stats_update_begin(&stats->syncp);
+ stats->bytes += length;
+ stats->packets++;
+ u64_stats_update_end(&stats->syncp);
+ } else {
+drop:
+ atomic64_inc(&priv->dropped);
+ }
+ rcu_read_unlock();
return NETDEV_TX_OK;
}
@@ -158,47 +142,63 @@ rx_drop:
* general routines
*/
-static struct rtnl_link_stats64 *veth_get_stats64(struct net_device *dev,
- struct rtnl_link_stats64 *tot)
+static u64 veth_stats_one(struct pcpu_vstats *result, struct net_device *dev)
{
struct veth_priv *priv = netdev_priv(dev);
int cpu;
+ result->packets = 0;
+ result->bytes = 0;
for_each_possible_cpu(cpu) {
- struct veth_net_stats *stats = per_cpu_ptr(priv->stats, cpu);
- u64 rx_packets, rx_bytes, rx_dropped;
- u64 tx_packets, tx_bytes;
+ struct pcpu_vstats *stats = per_cpu_ptr(dev->vstats, cpu);
+ u64 packets, bytes;
unsigned int start;
do {
start = u64_stats_fetch_begin_bh(&stats->syncp);
- rx_packets = stats->rx_packets;
- tx_packets = stats->tx_packets;
- rx_bytes = stats->rx_bytes;
- tx_bytes = stats->tx_bytes;
- rx_dropped = stats->rx_dropped;
+ packets = stats->packets;
+ bytes = stats->bytes;
} while (u64_stats_fetch_retry_bh(&stats->syncp, start));
- tot->rx_packets += rx_packets;
- tot->tx_packets += tx_packets;
- tot->rx_bytes += rx_bytes;
- tot->tx_bytes += tx_bytes;
- tot->rx_dropped += rx_dropped;
+ result->packets += packets;
+ result->bytes += bytes;
}
+ return atomic64_read(&priv->dropped);
+}
+
+static struct rtnl_link_stats64 *veth_get_stats64(struct net_device *dev,
+ struct rtnl_link_stats64 *tot)
+{
+ struct veth_priv *priv = netdev_priv(dev);
+ struct net_device *peer;
+ struct pcpu_vstats one;
+
+ tot->tx_dropped = veth_stats_one(&one, dev);
+ tot->tx_bytes = one.bytes;
+ tot->tx_packets = one.packets;
+
+ rcu_read_lock();
+ peer = rcu_dereference(priv->peer);
+ if (peer) {
+ tot->rx_dropped = veth_stats_one(&one, peer);
+ tot->rx_bytes = one.bytes;
+ tot->rx_packets = one.packets;
+ }
+ rcu_read_unlock();
return tot;
}
static int veth_open(struct net_device *dev)
{
- struct veth_priv *priv;
+ struct veth_priv *priv = netdev_priv(dev);
+ struct net_device *peer = rtnl_dereference(priv->peer);
- priv = netdev_priv(dev);
- if (priv->peer == NULL)
+ if (!peer)
return -ENOTCONN;
- if (priv->peer->flags & IFF_UP) {
+ if (peer->flags & IFF_UP) {
netif_carrier_on(dev);
- netif_carrier_on(priv->peer);
+ netif_carrier_on(peer);
}
return 0;
}
@@ -206,9 +206,11 @@ static int veth_open(struct net_device *dev)
static int veth_close(struct net_device *dev)
{
struct veth_priv *priv = netdev_priv(dev);
+ struct net_device *peer = rtnl_dereference(priv->peer);
netif_carrier_off(dev);
- netif_carrier_off(priv->peer);
+ if (peer)
+ netif_carrier_off(peer);
return 0;
}
@@ -228,24 +230,16 @@ static int veth_change_mtu(struct net_device *dev, int new_mtu)
static int veth_dev_init(struct net_device *dev)
{
- struct veth_net_stats __percpu *stats;
- struct veth_priv *priv;
-
- stats = alloc_percpu(struct veth_net_stats);
- if (stats == NULL)
+ dev->vstats = alloc_percpu(struct pcpu_vstats);
+ if (!dev->vstats)
return -ENOMEM;
- priv = netdev_priv(dev);
- priv->stats = stats;
return 0;
}
static void veth_dev_free(struct net_device *dev)
{
- struct veth_priv *priv;
-
- priv = netdev_priv(dev);
- free_percpu(priv->stats);
+ free_percpu(dev->vstats);
free_netdev(dev);
}
@@ -259,6 +253,10 @@ static const struct net_device_ops veth_netdev_ops = {
.ndo_set_mac_address = eth_mac_addr,
};
+#define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_ALL_TSO | \
+ NETIF_F_HW_CSUM | NETIF_F_RXCSUM | NETIF_F_HIGHDMA | \
+ NETIF_F_HW_VLAN_TX | NETIF_F_HW_VLAN_RX)
+
static void veth_setup(struct net_device *dev)
{
ether_setup(dev);
@@ -269,9 +267,10 @@ static void veth_setup(struct net_device *dev)
dev->netdev_ops = &veth_netdev_ops;
dev->ethtool_ops = &veth_ethtool_ops;
dev->features |= NETIF_F_LLTX;
+ dev->features |= VETH_FEATURES;
dev->destructor = veth_dev_free;
- dev->hw_features = NETIF_F_HW_CSUM | NETIF_F_SG | NETIF_F_RXCSUM;
+ dev->hw_features = VETH_FEATURES;
}
/*
@@ -396,10 +395,10 @@ static int veth_newlink(struct net *src_net, struct net_device *dev,
*/
priv = netdev_priv(dev);
- priv->peer = peer;
+ rcu_assign_pointer(priv->peer, peer);
priv = netdev_priv(peer);
- priv->peer = dev;
+ rcu_assign_pointer(priv->peer, dev);
return 0;
err_register_dev:
@@ -420,10 +419,20 @@ static void veth_dellink(struct net_device *dev, struct list_head *head)
struct net_device *peer;
priv = netdev_priv(dev);
- peer = priv->peer;
+ peer = rtnl_dereference(priv->peer);
+ /* Note : dellink() is called from default_device_exit_batch(),
+ * before a rcu_synchronize() point. The devices are guaranteed
+ * not being freed before one RCU grace period.
+ */
+ RCU_INIT_POINTER(priv->peer, NULL);
unregister_netdevice_queue(dev, head);
- unregister_netdevice_queue(peer, head);
+
+ if (peer) {
+ priv = netdev_priv(peer);
+ RCU_INIT_POINTER(priv->peer, NULL);
+ unregister_netdevice_queue(peer, head);
+ }
}
static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = {
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