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ipip: percpu stats accounting
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Maintain per_cpu tx_bytes, tx_packets, rx_bytes, rx_packets.

Other seldom used fields are kept in netdev->stats structure, possibly
unsafe.

This is a preliminary work to support lockless transmit path, and
correct RX stats, that are already unsafe.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Eric Dumazet authored and David S. Miller committed Sep 28, 2010
1 parent e985aad commit 3c97af9
Showing 1 changed file with 93 additions and 34 deletions.
127 changes: 93 additions & 34 deletions net/ipv4/ipip.c
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Original file line number Diff line number Diff line change
Expand Up @@ -131,8 +131,9 @@ struct ipip_net {
struct net_device *fb_tunnel_dev;
};

static void ipip_tunnel_init(struct net_device *dev);
static int ipip_tunnel_init(struct net_device *dev);
static void ipip_tunnel_setup(struct net_device *dev);
static void ipip_dev_free(struct net_device *dev);

/*
* Locking : hash tables are protected by RCU and RTNL
Expand All @@ -141,6 +142,34 @@ static void ipip_tunnel_setup(struct net_device *dev);
#define for_each_ip_tunnel_rcu(start) \
for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))

/* often modified stats are per cpu, other are shared (netdev->stats) */
struct pcpu_tstats {
unsigned long rx_packets;
unsigned long rx_bytes;
unsigned long tx_packets;
unsigned long tx_bytes;
};

static struct net_device_stats *ipip_get_stats(struct net_device *dev)
{
struct pcpu_tstats sum = { 0 };
int i;

for_each_possible_cpu(i) {
const struct pcpu_tstats *tstats = per_cpu_ptr(dev->tstats, i);

sum.rx_packets += tstats->rx_packets;
sum.rx_bytes += tstats->rx_bytes;
sum.tx_packets += tstats->tx_packets;
sum.tx_bytes += tstats->tx_bytes;
}
dev->stats.rx_packets = sum.rx_packets;
dev->stats.rx_bytes = sum.rx_bytes;
dev->stats.tx_packets = sum.tx_packets;
dev->stats.tx_bytes = sum.tx_bytes;
return &dev->stats;
}

static struct ip_tunnel * ipip_tunnel_lookup(struct net *net,
__be32 remote, __be32 local)
{
Expand Down Expand Up @@ -239,7 +268,7 @@ static struct ip_tunnel * ipip_tunnel_locate(struct net *net,
if (parms->name[0])
strlcpy(name, parms->name, IFNAMSIZ);
else
sprintf(name, "tunl%%d");
strcpy(name, "tunl%d");

dev = alloc_netdev(sizeof(*t), name, ipip_tunnel_setup);
if (dev == NULL)
Expand All @@ -255,7 +284,8 @@ static struct ip_tunnel * ipip_tunnel_locate(struct net *net,
nt = netdev_priv(dev);
nt->parms = *parms;

ipip_tunnel_init(dev);
if (ipip_tunnel_init(dev) < 0)
goto failed_free;

if (register_netdevice(dev) < 0)
goto failed_free;
Expand All @@ -265,7 +295,7 @@ static struct ip_tunnel * ipip_tunnel_locate(struct net *net,
return nt;

failed_free:
free_netdev(dev);
ipip_dev_free(dev);
return NULL;
}

Expand Down Expand Up @@ -359,8 +389,10 @@ static int ipip_rcv(struct sk_buff *skb)
const struct iphdr *iph = ip_hdr(skb);

rcu_read_lock();
if ((tunnel = ipip_tunnel_lookup(dev_net(skb->dev),
iph->saddr, iph->daddr)) != NULL) {
tunnel = ipip_tunnel_lookup(dev_net(skb->dev), iph->saddr, iph->daddr);
if (tunnel != NULL) {
struct pcpu_tstats *tstats;

if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) {
rcu_read_unlock();
kfree_skb(skb);
Expand All @@ -374,7 +406,11 @@ static int ipip_rcv(struct sk_buff *skb)
skb->protocol = htons(ETH_P_IP);
skb->pkt_type = PACKET_HOST;

skb_tunnel_rx(skb, tunnel->dev);
tstats = this_cpu_ptr(tunnel->dev->tstats);
tstats->rx_packets++;
tstats->rx_bytes += skb->len;

__skb_tunnel_rx(skb, tunnel->dev);

ipip_ecn_decapsulate(iph, skb);

Expand All @@ -397,13 +433,12 @@ static int ipip_rcv(struct sk_buff *skb)
static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct ip_tunnel *tunnel = netdev_priv(dev);
struct net_device_stats *stats = &dev->stats;
struct netdev_queue *txq = netdev_get_tx_queue(dev, 0);
struct pcpu_tstats *tstats;
struct iphdr *tiph = &tunnel->parms.iph;
u8 tos = tunnel->parms.iph.tos;
__be16 df = tiph->frag_off;
struct rtable *rt; /* Route to the other host */
struct net_device *tdev; /* Device to other host */
struct net_device *tdev; /* Device to other host */
struct iphdr *old_iph = ip_hdr(skb);
struct iphdr *iph; /* Our new IP header */
unsigned int max_headroom; /* The extra header space needed */
Expand All @@ -413,36 +448,42 @@ static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
if (skb->protocol != htons(ETH_P_IP))
goto tx_error;

if (tos&1)
if (tos & 1)
tos = old_iph->tos;

if (!dst) {
/* NBMA tunnel */
if ((rt = skb_rtable(skb)) == NULL) {
stats->tx_fifo_errors++;
dev->stats.tx_fifo_errors++;
goto tx_error;
}
if ((dst = rt->rt_gateway) == 0)
goto tx_error_icmp;
}

{
struct flowi fl = { .oif = tunnel->parms.link,
.nl_u = { .ip4_u =
{ .daddr = dst,
.saddr = tiph->saddr,
.tos = RT_TOS(tos) } },
.proto = IPPROTO_IPIP };
struct flowi fl = {
.oif = tunnel->parms.link,
.nl_u = {
.ip4_u = {
.daddr = dst,
.saddr = tiph->saddr,
.tos = RT_TOS(tos)
}
},
.proto = IPPROTO_IPIP
};

if (ip_route_output_key(dev_net(dev), &rt, &fl)) {
stats->tx_carrier_errors++;
dev->stats.tx_carrier_errors++;
goto tx_error_icmp;
}
}
tdev = rt->dst.dev;

if (tdev == dev) {
ip_rt_put(rt);
stats->collisions++;
dev->stats.collisions++;
goto tx_error;
}

Expand All @@ -452,7 +493,7 @@ static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
mtu = dst_mtu(&rt->dst) - sizeof(struct iphdr);

if (mtu < 68) {
stats->collisions++;
dev->stats.collisions++;
ip_rt_put(rt);
goto tx_error;
}
Expand Down Expand Up @@ -488,7 +529,7 @@ static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
if (!new_skb) {
ip_rt_put(rt);
txq->tx_dropped++;
dev->stats.tx_dropped++;
dev_kfree_skb(skb);
return NETDEV_TX_OK;
}
Expand Down Expand Up @@ -525,14 +566,14 @@ static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
iph->ttl = old_iph->ttl;

nf_reset(skb);

IPTUNNEL_XMIT();
tstats = this_cpu_ptr(dev->tstats);
__IPTUNNEL_XMIT(tstats, &dev->stats);
return NETDEV_TX_OK;

tx_error_icmp:
dst_link_failure(skb);
tx_error:
stats->tx_errors++;
dev->stats.tx_errors++;
dev_kfree_skb(skb);
return NETDEV_TX_OK;
}
Expand All @@ -547,13 +588,19 @@ static void ipip_tunnel_bind_dev(struct net_device *dev)
iph = &tunnel->parms.iph;

if (iph->daddr) {
struct flowi fl = { .oif = tunnel->parms.link,
.nl_u = { .ip4_u =
{ .daddr = iph->daddr,
.saddr = iph->saddr,
.tos = RT_TOS(iph->tos) } },
.proto = IPPROTO_IPIP };
struct flowi fl = {
.oif = tunnel->parms.link,
.nl_u = {
.ip4_u = {
.daddr = iph->daddr,
.saddr = iph->saddr,
.tos = RT_TOS(iph->tos)
}
},
.proto = IPPROTO_IPIP
};
struct rtable *rt;

if (!ip_route_output_key(dev_net(dev), &rt, &fl)) {
tdev = rt->dst.dev;
ip_rt_put(rt);
Expand Down Expand Up @@ -699,13 +746,19 @@ static const struct net_device_ops ipip_netdev_ops = {
.ndo_start_xmit = ipip_tunnel_xmit,
.ndo_do_ioctl = ipip_tunnel_ioctl,
.ndo_change_mtu = ipip_tunnel_change_mtu,

.ndo_get_stats = ipip_get_stats,
};

static void ipip_dev_free(struct net_device *dev)
{
free_percpu(dev->tstats);
free_netdev(dev);
}

static void ipip_tunnel_setup(struct net_device *dev)
{
dev->netdev_ops = &ipip_netdev_ops;
dev->destructor = free_netdev;
dev->destructor = ipip_dev_free;

dev->type = ARPHRD_TUNNEL;
dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr);
Expand All @@ -717,7 +770,7 @@ static void ipip_tunnel_setup(struct net_device *dev)
dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
}

static void ipip_tunnel_init(struct net_device *dev)
static int ipip_tunnel_init(struct net_device *dev)
{
struct ip_tunnel *tunnel = netdev_priv(dev);

Expand All @@ -728,6 +781,12 @@ static void ipip_tunnel_init(struct net_device *dev)
memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);

ipip_tunnel_bind_dev(dev);

dev->tstats = alloc_percpu(struct pcpu_tstats);
if (!dev->tstats)
return -ENOMEM;

return 0;
}

static void __net_init ipip_fb_tunnel_init(struct net_device *dev)
Expand Down

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