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veth.c
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// SPDX-License-Identifier: GPL-2.0-only
/*
* drivers/net/veth.c
*
* Copyright (C) 2007 OpenVZ http://openvz.org, SWsoft Inc
*
* Author: Pavel Emelianov <xemul@openvz.org>
* Ethtool interface from: Eric W. Biederman <ebiederm@xmission.com>
*
*/
#include <linux/netdevice.h>
#include <linux/slab.h>
#include <linux/ethtool.h>
#include <linux/etherdevice.h>
#include <linux/u64_stats_sync.h>
#include <net/rtnetlink.h>
#include <net/dst.h>
#include <net/xfrm.h>
#include <net/xdp.h>
#include <linux/veth.h>
#include <linux/module.h>
#include <linux/bpf.h>
#include <linux/filter.h>
#include <linux/ptr_ring.h>
#include <linux/bpf_trace.h>
#include <linux/net_tstamp.h>
#define DRV_NAME "veth"
#define DRV_VERSION "1.0"
#define VETH_XDP_FLAG BIT(0)
#define VETH_RING_SIZE 256
#define VETH_XDP_HEADROOM (XDP_PACKET_HEADROOM + NET_IP_ALIGN)
#define VETH_XDP_TX_BULK_SIZE 16
#define VETH_XDP_BATCH 16
struct veth_stats {
u64 rx_drops;
/* xdp */
u64 xdp_packets;
u64 xdp_bytes;
u64 xdp_redirect;
u64 xdp_drops;
u64 xdp_tx;
u64 xdp_tx_err;
u64 peer_tq_xdp_xmit;
u64 peer_tq_xdp_xmit_err;
};
struct veth_rq_stats {
struct veth_stats vs;
struct u64_stats_sync syncp;
};
struct veth_rq {
struct napi_struct xdp_napi;
struct napi_struct __rcu *napi; /* points to xdp_napi when the latter is initialized */
struct net_device *dev;
struct bpf_prog __rcu *xdp_prog;
struct xdp_mem_info xdp_mem;
struct veth_rq_stats stats;
bool rx_notify_masked;
struct ptr_ring xdp_ring;
struct xdp_rxq_info xdp_rxq;
};
struct veth_priv {
struct net_device __rcu *peer;
atomic64_t dropped;
struct bpf_prog *_xdp_prog;
struct veth_rq *rq;
unsigned int requested_headroom;
};
struct veth_xdp_tx_bq {
struct xdp_frame *q[VETH_XDP_TX_BULK_SIZE];
unsigned int count;
};
/*
* ethtool interface
*/
struct veth_q_stat_desc {
char desc[ETH_GSTRING_LEN];
size_t offset;
};
#define VETH_RQ_STAT(m) offsetof(struct veth_stats, m)
static const struct veth_q_stat_desc veth_rq_stats_desc[] = {
{ "xdp_packets", VETH_RQ_STAT(xdp_packets) },
{ "xdp_bytes", VETH_RQ_STAT(xdp_bytes) },
{ "drops", VETH_RQ_STAT(rx_drops) },
{ "xdp_redirect", VETH_RQ_STAT(xdp_redirect) },
{ "xdp_drops", VETH_RQ_STAT(xdp_drops) },
{ "xdp_tx", VETH_RQ_STAT(xdp_tx) },
{ "xdp_tx_errors", VETH_RQ_STAT(xdp_tx_err) },
};
#define VETH_RQ_STATS_LEN ARRAY_SIZE(veth_rq_stats_desc)
static const struct veth_q_stat_desc veth_tq_stats_desc[] = {
{ "xdp_xmit", VETH_RQ_STAT(peer_tq_xdp_xmit) },
{ "xdp_xmit_errors", VETH_RQ_STAT(peer_tq_xdp_xmit_err) },
};
#define VETH_TQ_STATS_LEN ARRAY_SIZE(veth_tq_stats_desc)
static struct {
const char string[ETH_GSTRING_LEN];
} ethtool_stats_keys[] = {
{ "peer_ifindex" },
};
static int veth_get_link_ksettings(struct net_device *dev,
struct ethtool_link_ksettings *cmd)
{
cmd->base.speed = SPEED_10000;
cmd->base.duplex = DUPLEX_FULL;
cmd->base.port = PORT_TP;
cmd->base.autoneg = AUTONEG_DISABLE;
return 0;
}
static void veth_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
{
strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
strlcpy(info->version, DRV_VERSION, sizeof(info->version));
}
static void veth_get_strings(struct net_device *dev, u32 stringset, u8 *buf)
{
u8 *p = buf;
int i, j;
switch(stringset) {
case ETH_SS_STATS:
memcpy(p, ðtool_stats_keys, sizeof(ethtool_stats_keys));
p += sizeof(ethtool_stats_keys);
for (i = 0; i < dev->real_num_rx_queues; i++)
for (j = 0; j < VETH_RQ_STATS_LEN; j++)
ethtool_sprintf(&p, "rx_queue_%u_%.18s",
i, veth_rq_stats_desc[j].desc);
for (i = 0; i < dev->real_num_tx_queues; i++)
for (j = 0; j < VETH_TQ_STATS_LEN; j++)
ethtool_sprintf(&p, "tx_queue_%u_%.18s",
i, veth_tq_stats_desc[j].desc);
break;
}
}
static int veth_get_sset_count(struct net_device *dev, int sset)
{
switch (sset) {
case ETH_SS_STATS:
return ARRAY_SIZE(ethtool_stats_keys) +
VETH_RQ_STATS_LEN * dev->real_num_rx_queues +
VETH_TQ_STATS_LEN * dev->real_num_tx_queues;
default:
return -EOPNOTSUPP;
}
}
static void veth_get_ethtool_stats(struct net_device *dev,
struct ethtool_stats *stats, u64 *data)
{
struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
struct net_device *peer = rtnl_dereference(priv->peer);
int i, j, idx;
data[0] = peer ? peer->ifindex : 0;
idx = 1;
for (i = 0; i < dev->real_num_rx_queues; i++) {
const struct veth_rq_stats *rq_stats = &priv->rq[i].stats;
const void *stats_base = (void *)&rq_stats->vs;
unsigned int start;
size_t offset;
do {
start = u64_stats_fetch_begin_irq(&rq_stats->syncp);
for (j = 0; j < VETH_RQ_STATS_LEN; j++) {
offset = veth_rq_stats_desc[j].offset;
data[idx + j] = *(u64 *)(stats_base + offset);
}
} while (u64_stats_fetch_retry_irq(&rq_stats->syncp, start));
idx += VETH_RQ_STATS_LEN;
}
if (!peer)
return;
rcv_priv = netdev_priv(peer);
for (i = 0; i < peer->real_num_rx_queues; i++) {
const struct veth_rq_stats *rq_stats = &rcv_priv->rq[i].stats;
const void *base = (void *)&rq_stats->vs;
unsigned int start, tx_idx = idx;
size_t offset;
tx_idx += (i % dev->real_num_tx_queues) * VETH_TQ_STATS_LEN;
do {
start = u64_stats_fetch_begin_irq(&rq_stats->syncp);
for (j = 0; j < VETH_TQ_STATS_LEN; j++) {
offset = veth_tq_stats_desc[j].offset;
data[tx_idx + j] += *(u64 *)(base + offset);
}
} while (u64_stats_fetch_retry_irq(&rq_stats->syncp, start));
}
}
static void veth_get_channels(struct net_device *dev,
struct ethtool_channels *channels)
{
channels->tx_count = dev->real_num_tx_queues;
channels->rx_count = dev->real_num_rx_queues;
channels->max_tx = dev->num_tx_queues;
channels->max_rx = dev->num_rx_queues;
}
static int veth_set_channels(struct net_device *dev,
struct ethtool_channels *ch);
static const struct ethtool_ops veth_ethtool_ops = {
.get_drvinfo = veth_get_drvinfo,
.get_link = ethtool_op_get_link,
.get_strings = veth_get_strings,
.get_sset_count = veth_get_sset_count,
.get_ethtool_stats = veth_get_ethtool_stats,
.get_link_ksettings = veth_get_link_ksettings,
.get_ts_info = ethtool_op_get_ts_info,
.get_channels = veth_get_channels,
.set_channels = veth_set_channels,
};
/* general routines */
static bool veth_is_xdp_frame(void *ptr)
{
return (unsigned long)ptr & VETH_XDP_FLAG;
}
static struct xdp_frame *veth_ptr_to_xdp(void *ptr)
{
return (void *)((unsigned long)ptr & ~VETH_XDP_FLAG);
}
static void *veth_xdp_to_ptr(struct xdp_frame *xdp)
{
return (void *)((unsigned long)xdp | VETH_XDP_FLAG);
}
static void veth_ptr_free(void *ptr)
{
if (veth_is_xdp_frame(ptr))
xdp_return_frame(veth_ptr_to_xdp(ptr));
else
kfree_skb(ptr);
}
static void __veth_xdp_flush(struct veth_rq *rq)
{
/* Write ptr_ring before reading rx_notify_masked */
smp_mb();
if (!rq->rx_notify_masked) {
rq->rx_notify_masked = true;
napi_schedule(&rq->xdp_napi);
}
}
static int veth_xdp_rx(struct veth_rq *rq, struct sk_buff *skb)
{
if (unlikely(ptr_ring_produce(&rq->xdp_ring, skb))) {
dev_kfree_skb_any(skb);
return NET_RX_DROP;
}
return NET_RX_SUCCESS;
}
static int veth_forward_skb(struct net_device *dev, struct sk_buff *skb,
struct veth_rq *rq, bool xdp)
{
return __dev_forward_skb(dev, skb) ?: xdp ?
veth_xdp_rx(rq, skb) :
netif_rx(skb);
}
/* return true if the specified skb has chances of GRO aggregation
* Don't strive for accuracy, but try to avoid GRO overhead in the most
* common scenarios.
* When XDP is enabled, all traffic is considered eligible, as the xmit
* device has TSO off.
* When TSO is enabled on the xmit device, we are likely interested only
* in UDP aggregation, explicitly check for that if the skb is suspected
* - the sock_wfree destructor is used by UDP, ICMP and XDP sockets -
* to belong to locally generated UDP traffic.
*/
static bool veth_skb_is_eligible_for_gro(const struct net_device *dev,
const struct net_device *rcv,
const struct sk_buff *skb)
{
return !(dev->features & NETIF_F_ALL_TSO) ||
(skb->destructor == sock_wfree &&
rcv->features & (NETIF_F_GRO_FRAGLIST | NETIF_F_GRO_UDP_FWD));
}
static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
struct veth_rq *rq = NULL;
struct net_device *rcv;
int length = skb->len;
bool use_napi = false;
int rxq;
rcu_read_lock();
rcv = rcu_dereference(priv->peer);
if (unlikely(!rcv)) {
kfree_skb(skb);
goto drop;
}
rcv_priv = netdev_priv(rcv);
rxq = skb_get_queue_mapping(skb);
if (rxq < rcv->real_num_rx_queues) {
rq = &rcv_priv->rq[rxq];
/* The napi pointer is available when an XDP program is
* attached or when GRO is enabled
* Don't bother with napi/GRO if the skb can't be aggregated
*/
use_napi = rcu_access_pointer(rq->napi) &&
veth_skb_is_eligible_for_gro(dev, rcv, skb);
skb_record_rx_queue(skb, rxq);
}
skb_tx_timestamp(skb);
if (likely(veth_forward_skb(rcv, skb, rq, use_napi) == NET_RX_SUCCESS)) {
if (!use_napi)
dev_lstats_add(dev, length);
} else {
drop:
atomic64_inc(&priv->dropped);
}
if (use_napi)
__veth_xdp_flush(rq);
rcu_read_unlock();
return NETDEV_TX_OK;
}
static u64 veth_stats_tx(struct net_device *dev, u64 *packets, u64 *bytes)
{
struct veth_priv *priv = netdev_priv(dev);
dev_lstats_read(dev, packets, bytes);
return atomic64_read(&priv->dropped);
}
static void veth_stats_rx(struct veth_stats *result, struct net_device *dev)
{
struct veth_priv *priv = netdev_priv(dev);
int i;
result->peer_tq_xdp_xmit_err = 0;
result->xdp_packets = 0;
result->xdp_tx_err = 0;
result->xdp_bytes = 0;
result->rx_drops = 0;
for (i = 0; i < dev->num_rx_queues; i++) {
u64 packets, bytes, drops, xdp_tx_err, peer_tq_xdp_xmit_err;
struct veth_rq_stats *stats = &priv->rq[i].stats;
unsigned int start;
do {
start = u64_stats_fetch_begin_irq(&stats->syncp);
peer_tq_xdp_xmit_err = stats->vs.peer_tq_xdp_xmit_err;
xdp_tx_err = stats->vs.xdp_tx_err;
packets = stats->vs.xdp_packets;
bytes = stats->vs.xdp_bytes;
drops = stats->vs.rx_drops;
} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
result->peer_tq_xdp_xmit_err += peer_tq_xdp_xmit_err;
result->xdp_tx_err += xdp_tx_err;
result->xdp_packets += packets;
result->xdp_bytes += bytes;
result->rx_drops += drops;
}
}
static void veth_get_stats64(struct net_device *dev,
struct rtnl_link_stats64 *tot)
{
struct veth_priv *priv = netdev_priv(dev);
struct net_device *peer;
struct veth_stats rx;
u64 packets, bytes;
tot->tx_dropped = veth_stats_tx(dev, &packets, &bytes);
tot->tx_bytes = bytes;
tot->tx_packets = packets;
veth_stats_rx(&rx, dev);
tot->tx_dropped += rx.xdp_tx_err;
tot->rx_dropped = rx.rx_drops + rx.peer_tq_xdp_xmit_err;
tot->rx_bytes = rx.xdp_bytes;
tot->rx_packets = rx.xdp_packets;
rcu_read_lock();
peer = rcu_dereference(priv->peer);
if (peer) {
veth_stats_tx(peer, &packets, &bytes);
tot->rx_bytes += bytes;
tot->rx_packets += packets;
veth_stats_rx(&rx, peer);
tot->tx_dropped += rx.peer_tq_xdp_xmit_err;
tot->rx_dropped += rx.xdp_tx_err;
tot->tx_bytes += rx.xdp_bytes;
tot->tx_packets += rx.xdp_packets;
}
rcu_read_unlock();
}
/* fake multicast ability */
static void veth_set_multicast_list(struct net_device *dev)
{
}
static struct sk_buff *veth_build_skb(void *head, int headroom, int len,
int buflen)
{
struct sk_buff *skb;
skb = build_skb(head, buflen);
if (!skb)
return NULL;
skb_reserve(skb, headroom);
skb_put(skb, len);
return skb;
}
static int veth_select_rxq(struct net_device *dev)
{
return smp_processor_id() % dev->real_num_rx_queues;
}
static struct net_device *veth_peer_dev(struct net_device *dev)
{
struct veth_priv *priv = netdev_priv(dev);
/* Callers must be under RCU read side. */
return rcu_dereference(priv->peer);
}
static int veth_xdp_xmit(struct net_device *dev, int n,
struct xdp_frame **frames,
u32 flags, bool ndo_xmit)
{
struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
int i, ret = -ENXIO, nxmit = 0;
struct net_device *rcv;
unsigned int max_len;
struct veth_rq *rq;
if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
return -EINVAL;
rcu_read_lock();
rcv = rcu_dereference(priv->peer);
if (unlikely(!rcv))
goto out;
rcv_priv = netdev_priv(rcv);
rq = &rcv_priv->rq[veth_select_rxq(rcv)];
/* The napi pointer is set if NAPI is enabled, which ensures that
* xdp_ring is initialized on receive side and the peer device is up.
*/
if (!rcu_access_pointer(rq->napi))
goto out;
max_len = rcv->mtu + rcv->hard_header_len + VLAN_HLEN;
spin_lock(&rq->xdp_ring.producer_lock);
for (i = 0; i < n; i++) {
struct xdp_frame *frame = frames[i];
void *ptr = veth_xdp_to_ptr(frame);
if (unlikely(frame->len > max_len ||
__ptr_ring_produce(&rq->xdp_ring, ptr)))
break;
nxmit++;
}
spin_unlock(&rq->xdp_ring.producer_lock);
if (flags & XDP_XMIT_FLUSH)
__veth_xdp_flush(rq);
ret = nxmit;
if (ndo_xmit) {
u64_stats_update_begin(&rq->stats.syncp);
rq->stats.vs.peer_tq_xdp_xmit += nxmit;
rq->stats.vs.peer_tq_xdp_xmit_err += n - nxmit;
u64_stats_update_end(&rq->stats.syncp);
}
out:
rcu_read_unlock();
return ret;
}
static int veth_ndo_xdp_xmit(struct net_device *dev, int n,
struct xdp_frame **frames, u32 flags)
{
int err;
err = veth_xdp_xmit(dev, n, frames, flags, true);
if (err < 0) {
struct veth_priv *priv = netdev_priv(dev);
atomic64_add(n, &priv->dropped);
}
return err;
}
static void veth_xdp_flush_bq(struct veth_rq *rq, struct veth_xdp_tx_bq *bq)
{
int sent, i, err = 0, drops;
sent = veth_xdp_xmit(rq->dev, bq->count, bq->q, 0, false);
if (sent < 0) {
err = sent;
sent = 0;
}
for (i = sent; unlikely(i < bq->count); i++)
xdp_return_frame(bq->q[i]);
drops = bq->count - sent;
trace_xdp_bulk_tx(rq->dev, sent, drops, err);
u64_stats_update_begin(&rq->stats.syncp);
rq->stats.vs.xdp_tx += sent;
rq->stats.vs.xdp_tx_err += drops;
u64_stats_update_end(&rq->stats.syncp);
bq->count = 0;
}
static void veth_xdp_flush(struct veth_rq *rq, struct veth_xdp_tx_bq *bq)
{
struct veth_priv *rcv_priv, *priv = netdev_priv(rq->dev);
struct net_device *rcv;
struct veth_rq *rcv_rq;
rcu_read_lock();
veth_xdp_flush_bq(rq, bq);
rcv = rcu_dereference(priv->peer);
if (unlikely(!rcv))
goto out;
rcv_priv = netdev_priv(rcv);
rcv_rq = &rcv_priv->rq[veth_select_rxq(rcv)];
/* xdp_ring is initialized on receive side? */
if (unlikely(!rcu_access_pointer(rcv_rq->xdp_prog)))
goto out;
__veth_xdp_flush(rcv_rq);
out:
rcu_read_unlock();
}
static int veth_xdp_tx(struct veth_rq *rq, struct xdp_buff *xdp,
struct veth_xdp_tx_bq *bq)
{
struct xdp_frame *frame = xdp_convert_buff_to_frame(xdp);
if (unlikely(!frame))
return -EOVERFLOW;
if (unlikely(bq->count == VETH_XDP_TX_BULK_SIZE))
veth_xdp_flush_bq(rq, bq);
bq->q[bq->count++] = frame;
return 0;
}
static struct xdp_frame *veth_xdp_rcv_one(struct veth_rq *rq,
struct xdp_frame *frame,
struct veth_xdp_tx_bq *bq,
struct veth_stats *stats)
{
struct xdp_frame orig_frame;
struct bpf_prog *xdp_prog;
rcu_read_lock();
xdp_prog = rcu_dereference(rq->xdp_prog);
if (likely(xdp_prog)) {
struct xdp_buff xdp;
u32 act;
xdp_convert_frame_to_buff(frame, &xdp);
xdp.rxq = &rq->xdp_rxq;
act = bpf_prog_run_xdp(xdp_prog, &xdp);
switch (act) {
case XDP_PASS:
if (xdp_update_frame_from_buff(&xdp, frame))
goto err_xdp;
break;
case XDP_TX:
orig_frame = *frame;
xdp.rxq->mem = frame->mem;
if (unlikely(veth_xdp_tx(rq, &xdp, bq) < 0)) {
trace_xdp_exception(rq->dev, xdp_prog, act);
frame = &orig_frame;
stats->rx_drops++;
goto err_xdp;
}
stats->xdp_tx++;
rcu_read_unlock();
goto xdp_xmit;
case XDP_REDIRECT:
orig_frame = *frame;
xdp.rxq->mem = frame->mem;
if (xdp_do_redirect(rq->dev, &xdp, xdp_prog)) {
frame = &orig_frame;
stats->rx_drops++;
goto err_xdp;
}
stats->xdp_redirect++;
rcu_read_unlock();
goto xdp_xmit;
default:
bpf_warn_invalid_xdp_action(act);
fallthrough;
case XDP_ABORTED:
trace_xdp_exception(rq->dev, xdp_prog, act);
fallthrough;
case XDP_DROP:
stats->xdp_drops++;
goto err_xdp;
}
}
rcu_read_unlock();
return frame;
err_xdp:
rcu_read_unlock();
xdp_return_frame(frame);
xdp_xmit:
return NULL;
}
/* frames array contains VETH_XDP_BATCH at most */
static void veth_xdp_rcv_bulk_skb(struct veth_rq *rq, void **frames,
int n_xdpf, struct veth_xdp_tx_bq *bq,
struct veth_stats *stats)
{
void *skbs[VETH_XDP_BATCH];
int i;
if (xdp_alloc_skb_bulk(skbs, n_xdpf,
GFP_ATOMIC | __GFP_ZERO) < 0) {
for (i = 0; i < n_xdpf; i++)
xdp_return_frame(frames[i]);
stats->rx_drops += n_xdpf;
return;
}
for (i = 0; i < n_xdpf; i++) {
struct sk_buff *skb = skbs[i];
skb = __xdp_build_skb_from_frame(frames[i], skb,
rq->dev);
if (!skb) {
xdp_return_frame(frames[i]);
stats->rx_drops++;
continue;
}
napi_gro_receive(&rq->xdp_napi, skb);
}
}
static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq,
struct sk_buff *skb,
struct veth_xdp_tx_bq *bq,
struct veth_stats *stats)
{
u32 pktlen, headroom, act, metalen, frame_sz;
void *orig_data, *orig_data_end;
struct bpf_prog *xdp_prog;
int mac_len, delta, off;
struct xdp_buff xdp;
skb_prepare_for_gro(skb);
rcu_read_lock();
xdp_prog = rcu_dereference(rq->xdp_prog);
if (unlikely(!xdp_prog)) {
rcu_read_unlock();
goto out;
}
mac_len = skb->data - skb_mac_header(skb);
pktlen = skb->len + mac_len;
headroom = skb_headroom(skb) - mac_len;
if (skb_shared(skb) || skb_head_is_locked(skb) ||
skb_is_nonlinear(skb) || headroom < XDP_PACKET_HEADROOM) {
struct sk_buff *nskb;
int size, head_off;
void *head, *start;
struct page *page;
size = SKB_DATA_ALIGN(VETH_XDP_HEADROOM + pktlen) +
SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
if (size > PAGE_SIZE)
goto drop;
page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
if (!page)
goto drop;
head = page_address(page);
start = head + VETH_XDP_HEADROOM;
if (skb_copy_bits(skb, -mac_len, start, pktlen)) {
page_frag_free(head);
goto drop;
}
nskb = veth_build_skb(head, VETH_XDP_HEADROOM + mac_len,
skb->len, PAGE_SIZE);
if (!nskb) {
page_frag_free(head);
goto drop;
}
skb_copy_header(nskb, skb);
head_off = skb_headroom(nskb) - skb_headroom(skb);
skb_headers_offset_update(nskb, head_off);
consume_skb(skb);
skb = nskb;
}
/* SKB "head" area always have tailroom for skb_shared_info */
frame_sz = skb_end_pointer(skb) - skb->head;
frame_sz += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
xdp_init_buff(&xdp, frame_sz, &rq->xdp_rxq);
xdp_prepare_buff(&xdp, skb->head, skb->mac_header, pktlen, true);
orig_data = xdp.data;
orig_data_end = xdp.data_end;
act = bpf_prog_run_xdp(xdp_prog, &xdp);
switch (act) {
case XDP_PASS:
break;
case XDP_TX:
get_page(virt_to_page(xdp.data));
consume_skb(skb);
xdp.rxq->mem = rq->xdp_mem;
if (unlikely(veth_xdp_tx(rq, &xdp, bq) < 0)) {
trace_xdp_exception(rq->dev, xdp_prog, act);
stats->rx_drops++;
goto err_xdp;
}
stats->xdp_tx++;
rcu_read_unlock();
goto xdp_xmit;
case XDP_REDIRECT:
get_page(virt_to_page(xdp.data));
consume_skb(skb);
xdp.rxq->mem = rq->xdp_mem;
if (xdp_do_redirect(rq->dev, &xdp, xdp_prog)) {
stats->rx_drops++;
goto err_xdp;
}
stats->xdp_redirect++;
rcu_read_unlock();
goto xdp_xmit;
default:
bpf_warn_invalid_xdp_action(act);
fallthrough;
case XDP_ABORTED:
trace_xdp_exception(rq->dev, xdp_prog, act);
fallthrough;
case XDP_DROP:
stats->xdp_drops++;
goto xdp_drop;
}
rcu_read_unlock();
/* check if bpf_xdp_adjust_head was used */
delta = orig_data - xdp.data;
off = mac_len + delta;
if (off > 0)
__skb_push(skb, off);
else if (off < 0)
__skb_pull(skb, -off);
skb->mac_header -= delta;
/* check if bpf_xdp_adjust_tail was used */
off = xdp.data_end - orig_data_end;
if (off != 0)
__skb_put(skb, off); /* positive on grow, negative on shrink */
skb->protocol = eth_type_trans(skb, rq->dev);
metalen = xdp.data - xdp.data_meta;
if (metalen)
skb_metadata_set(skb, metalen);
out:
return skb;
drop:
stats->rx_drops++;
xdp_drop:
rcu_read_unlock();
kfree_skb(skb);
return NULL;
err_xdp:
rcu_read_unlock();
page_frag_free(xdp.data);
xdp_xmit:
return NULL;
}
static int veth_xdp_rcv(struct veth_rq *rq, int budget,
struct veth_xdp_tx_bq *bq,
struct veth_stats *stats)
{
int i, done = 0, n_xdpf = 0;
void *xdpf[VETH_XDP_BATCH];
for (i = 0; i < budget; i++) {
void *ptr = __ptr_ring_consume(&rq->xdp_ring);
if (!ptr)
break;
if (veth_is_xdp_frame(ptr)) {
/* ndo_xdp_xmit */
struct xdp_frame *frame = veth_ptr_to_xdp(ptr);
stats->xdp_bytes += frame->len;
frame = veth_xdp_rcv_one(rq, frame, bq, stats);
if (frame) {
/* XDP_PASS */
xdpf[n_xdpf++] = frame;
if (n_xdpf == VETH_XDP_BATCH) {
veth_xdp_rcv_bulk_skb(rq, xdpf, n_xdpf,
bq, stats);
n_xdpf = 0;
}
}
} else {
/* ndo_start_xmit */
struct sk_buff *skb = ptr;
stats->xdp_bytes += skb->len;
skb = veth_xdp_rcv_skb(rq, skb, bq, stats);
if (skb)
napi_gro_receive(&rq->xdp_napi, skb);
}
done++;
}
if (n_xdpf)
veth_xdp_rcv_bulk_skb(rq, xdpf, n_xdpf, bq, stats);
u64_stats_update_begin(&rq->stats.syncp);
rq->stats.vs.xdp_redirect += stats->xdp_redirect;
rq->stats.vs.xdp_bytes += stats->xdp_bytes;
rq->stats.vs.xdp_drops += stats->xdp_drops;
rq->stats.vs.rx_drops += stats->rx_drops;
rq->stats.vs.xdp_packets += done;
u64_stats_update_end(&rq->stats.syncp);
return done;
}
static int veth_poll(struct napi_struct *napi, int budget)
{
struct veth_rq *rq =
container_of(napi, struct veth_rq, xdp_napi);
struct veth_stats stats = {};
struct veth_xdp_tx_bq bq;
int done;
bq.count = 0;
xdp_set_return_frame_no_direct();
done = veth_xdp_rcv(rq, budget, &bq, &stats);
if (done < budget && napi_complete_done(napi, done)) {
/* Write rx_notify_masked before reading ptr_ring */
smp_store_mb(rq->rx_notify_masked, false);
if (unlikely(!__ptr_ring_empty(&rq->xdp_ring))) {
rq->rx_notify_masked = true;
napi_schedule(&rq->xdp_napi);
}
}
if (stats.xdp_tx > 0)
veth_xdp_flush(rq, &bq);
if (stats.xdp_redirect > 0)
xdp_do_flush();
xdp_clear_return_frame_no_direct();
return done;
}
static int __veth_napi_enable_range(struct net_device *dev, int start, int end)
{
struct veth_priv *priv = netdev_priv(dev);
int err, i;
for (i = start; i < end; i++) {
struct veth_rq *rq = &priv->rq[i];
err = ptr_ring_init(&rq->xdp_ring, VETH_RING_SIZE, GFP_KERNEL);
if (err)
goto err_xdp_ring;
}
for (i = start; i < end; i++) {
struct veth_rq *rq = &priv->rq[i];
napi_enable(&rq->xdp_napi);
rcu_assign_pointer(priv->rq[i].napi, &priv->rq[i].xdp_napi);
}
return 0;
err_xdp_ring:
for (i--; i >= start; i--)
ptr_ring_cleanup(&priv->rq[i].xdp_ring, veth_ptr_free);
return err;
}
static int __veth_napi_enable(struct net_device *dev)
{
return __veth_napi_enable_range(dev, 0, dev->real_num_rx_queues);
}
static void veth_napi_del_range(struct net_device *dev, int start, int end)
{
struct veth_priv *priv = netdev_priv(dev);
int i;
for (i = start; i < end; i++) {
struct veth_rq *rq = &priv->rq[i];
rcu_assign_pointer(priv->rq[i].napi, NULL);
napi_disable(&rq->xdp_napi);
__netif_napi_del(&rq->xdp_napi);
}
synchronize_net();
for (i = start; i < end; i++) {
struct veth_rq *rq = &priv->rq[i];
rq->rx_notify_masked = false;
ptr_ring_cleanup(&rq->xdp_ring, veth_ptr_free);
}
}
static void veth_napi_del(struct net_device *dev)
{
veth_napi_del_range(dev, 0, dev->real_num_rx_queues);
}
static bool veth_gro_requested(const struct net_device *dev)
{
return !!(dev->wanted_features & NETIF_F_GRO);
}
static int veth_enable_xdp_range(struct net_device *dev, int start, int end,
bool napi_already_on)
{
struct veth_priv *priv = netdev_priv(dev);
int err, i;
for (i = start; i < end; i++) {
struct veth_rq *rq = &priv->rq[i];