// 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)
/* Separating two types of XDP xmit */
#define VETH_XDP_TX BIT(0)
#define VETH_XDP_REDIR BIT(1)
#define VETH_XDP_TX_BULK_SIZE 16
struct veth_rq_stats {
u64 xdp_packets;
u64 xdp_bytes;
u64 xdp_drops;
struct u64_stats_sync syncp;
};
struct veth_rq {
struct napi_struct xdp_napi;
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_rq_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) },
{ "xdp_drops", VETH_RQ_STAT(xdp_drops) },
};
#define VETH_RQ_STATS_LEN ARRAY_SIZE(veth_rq_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)
{
char *p = (char *)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++) {
snprintf(p, ETH_GSTRING_LEN,
"rx_queue_%u_%.11s",
i, veth_rq_stats_desc[j].desc);
p += ETH_GSTRING_LEN;
}
}
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;
default:
return -EOPNOTSUPP;
}
}
static void veth_get_ethtool_stats(struct net_device *dev,
struct ethtool_stats *stats, u64 *data)
{
struct veth_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;
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;
}
}
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,
};
/* general routines */
static bool veth_is_xdp_frame(void *ptr)
{
return (unsigned long)ptr & VETH_XDP_FLAG;
}
static void *veth_ptr_to_xdp(void *ptr)
{
return (void *)((unsigned long)ptr & ~VETH_XDP_FLAG);
}
static void *veth_xdp_to_ptr(void *ptr)
{
return (void *)((unsigned long)ptr | 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);
}
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 rcv_xdp = 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];
rcv_xdp = rcu_access_pointer(rq->xdp_prog);
if (rcv_xdp)
skb_record_rx_queue(skb, rxq);
}
skb_tx_timestamp(skb);
if (likely(veth_forward_skb(rcv, skb, rq, rcv_xdp) == NET_RX_SUCCESS)) {
if (!rcv_xdp) {
struct pcpu_lstats *stats = this_cpu_ptr(dev->lstats);
u64_stats_update_begin(&stats->syncp);
stats->bytes += length;
stats->packets++;
u64_stats_update_end(&stats->syncp);
}
} else {
drop:
atomic64_inc(&priv->dropped);
}
if (rcv_xdp)
__veth_xdp_flush(rq);
rcu_read_unlock();
return NETDEV_TX_OK;
}
static u64 veth_stats_tx(struct pcpu_lstats *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 pcpu_lstats *stats = per_cpu_ptr(dev->lstats, cpu);
u64 packets, bytes;
unsigned int start;
do {
start = u64_stats_fetch_begin_irq(&stats->syncp);
packets = stats->packets;
bytes = stats->bytes;
} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
result->packets += packets;
result->bytes += bytes;
}
return atomic64_read(&priv->dropped);
}
static void veth_stats_rx(struct veth_rq_stats *result, struct net_device *dev)
{
struct veth_priv *priv = netdev_priv(dev);
int i;
result->xdp_packets = 0;
result->xdp_bytes = 0;
result->xdp_drops = 0;
for (i = 0; i < dev->num_rx_queues; i++) {
struct veth_rq_stats *stats = &priv->rq[i].stats;
u64 packets, bytes, drops;
unsigned int start;
do {
start = u64_stats_fetch_begin_irq(&stats->syncp);
packets = stats->xdp_packets;
bytes = stats->xdp_bytes;
drops = stats->xdp_drops;
} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
result->xdp_packets += packets;
result->xdp_bytes += bytes;
result->xdp_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_rq_stats rx;
struct pcpu_lstats tx;
tot->tx_dropped = veth_stats_tx(&tx, dev);
tot->tx_bytes = tx.bytes;
tot->tx_packets = tx.packets;
veth_stats_rx(&rx, dev);
tot->rx_dropped = rx.xdp_drops;
tot->rx_bytes = rx.xdp_bytes;
tot->rx_packets = rx.xdp_packets;
rcu_read_lock();
peer = rcu_dereference(priv->peer);
if (peer) {
tot->rx_dropped += veth_stats_tx(&tx, peer);
tot->rx_bytes += tx.bytes;
tot->rx_packets += tx.packets;
veth_stats_rx(&rx, peer);
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;
if (!buflen) {
buflen = SKB_DATA_ALIGN(headroom + len) +
SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
}
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 int veth_xdp_xmit(struct net_device *dev, int n,
struct xdp_frame **frames, u32 flags)
{
struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
struct net_device *rcv;
int i, ret, drops = n;
unsigned int max_len;
struct veth_rq *rq;
if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK)) {
ret = -EINVAL;
goto drop;
}
rcv = rcu_dereference(priv->peer);
if (unlikely(!rcv)) {
ret = -ENXIO;
goto drop;
}
rcv_priv = netdev_priv(rcv);
rq = &rcv_priv->rq[veth_select_rxq(rcv)];
/* Non-NULL xdp_prog ensures that xdp_ring is initialized on receive
* side. This means an XDP program is loaded on the peer and the peer
* device is up.
*/
if (!rcu_access_pointer(rq->xdp_prog)) {
ret = -ENXIO;
goto drop;
}
drops = 0;
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))) {
xdp_return_frame_rx_napi(frame);
drops++;
}
}
spin_unlock(&rq->xdp_ring.producer_lock);
if (flags & XDP_XMIT_FLUSH)
__veth_xdp_flush(rq);
if (likely(!drops))
return n;
ret = n - drops;
drop:
atomic64_add(drops, &priv->dropped);
return ret;
}
static void veth_xdp_flush_bq(struct net_device *dev, struct veth_xdp_tx_bq *bq)
{
int sent, i, err = 0;
sent = veth_xdp_xmit(dev, bq->count, bq->q, 0);
if (sent < 0) {
err = sent;
sent = 0;
for (i = 0; i < bq->count; i++)
xdp_return_frame(bq->q[i]);
}
trace_xdp_bulk_tx(dev, sent, bq->count - sent, err);
bq->count = 0;
}
static void veth_xdp_flush(struct net_device *dev, struct veth_xdp_tx_bq *bq)
{
struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
struct net_device *rcv;
struct veth_rq *rq;
rcu_read_lock();
veth_xdp_flush_bq(dev, bq);
rcv = rcu_dereference(priv->peer);
if (unlikely(!rcv))
goto out;
rcv_priv = netdev_priv(rcv);
rq = &rcv_priv->rq[veth_select_rxq(rcv)];
/* xdp_ring is initialized on receive side? */
if (unlikely(!rcu_access_pointer(rq->xdp_prog)))
goto out;
__veth_xdp_flush(rq);
out:
rcu_read_unlock();
}
static int veth_xdp_tx(struct net_device *dev, struct xdp_buff *xdp,
struct veth_xdp_tx_bq *bq)
{
struct xdp_frame *frame = convert_to_xdp_frame(xdp);
if (unlikely(!frame))
return -EOVERFLOW;
if (unlikely(bq->count == VETH_XDP_TX_BULK_SIZE))
veth_xdp_flush_bq(dev, bq);
bq->q[bq->count++] = frame;
return 0;
}
static struct sk_buff *veth_xdp_rcv_one(struct veth_rq *rq,
struct xdp_frame *frame,
unsigned int *xdp_xmit,
struct veth_xdp_tx_bq *bq)
{
void *hard_start = frame->data - frame->headroom;
void *head = hard_start - sizeof(struct xdp_frame);
int len = frame->len, delta = 0;
struct xdp_frame orig_frame;
struct bpf_prog *xdp_prog;
unsigned int headroom;
struct sk_buff *skb;
rcu_read_lock();
xdp_prog = rcu_dereference(rq->xdp_prog);
if (likely(xdp_prog)) {
struct xdp_buff xdp;
u32 act;
xdp.data_hard_start = hard_start;
xdp.data = frame->data;
xdp.data_end = frame->data + frame->len;
xdp.data_meta = frame->data - frame->metasize;
xdp.rxq = &rq->xdp_rxq;
act = bpf_prog_run_xdp(xdp_prog, &xdp);
switch (act) {
case XDP_PASS:
delta = frame->data - xdp.data;
len = xdp.data_end - xdp.data;
break;
case XDP_TX:
orig_frame = *frame;
xdp.data_hard_start = head;
xdp.rxq->mem = frame->mem;
if (unlikely(veth_xdp_tx(rq->dev, &xdp, bq) < 0)) {
trace_xdp_exception(rq->dev, xdp_prog, act);
frame = &orig_frame;
goto err_xdp;
}
*xdp_xmit |= VETH_XDP_TX;
rcu_read_unlock();
goto xdp_xmit;
case XDP_REDIRECT:
orig_frame = *frame;
xdp.data_hard_start = head;
xdp.rxq->mem = frame->mem;
if (xdp_do_redirect(rq->dev, &xdp, xdp_prog)) {
frame = &orig_frame;
goto err_xdp;
}
*xdp_xmit |= VETH_XDP_REDIR;
rcu_read_unlock();
goto xdp_xmit;
default:
bpf_warn_invalid_xdp_action(act);
/* fall through */
case XDP_ABORTED:
trace_xdp_exception(rq->dev, xdp_prog, act);
/* fall through */
case XDP_DROP:
goto err_xdp;
}
}
rcu_read_unlock();
headroom = sizeof(struct xdp_frame) + frame->headroom - delta;
skb = veth_build_skb(head, headroom, len, 0);
if (!skb) {
xdp_return_frame(frame);
goto err;
}
xdp_release_frame(frame);
xdp_scrub_frame(frame);
skb->protocol = eth_type_trans(skb, rq->dev);
err:
return skb;
err_xdp:
rcu_read_unlock();
xdp_return_frame(frame);
xdp_xmit:
return NULL;
}
static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq, struct sk_buff *skb,
unsigned int *xdp_xmit,
struct veth_xdp_tx_bq *bq)
{
u32 pktlen, headroom, act, metalen;
void *orig_data, *orig_data_end;
struct bpf_prog *xdp_prog;
int mac_len, delta, off;
struct xdp_buff xdp;
skb_orphan(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;
}
xdp.data_hard_start = skb->head;
xdp.data = skb_mac_header(skb);
xdp.data_end = xdp.data + pktlen;
xdp.data_meta = xdp.data;
xdp.rxq = &rq->xdp_rxq;
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->dev, &xdp, bq) < 0)) {
trace_xdp_exception(rq->dev, xdp_prog, act);
goto err_xdp;
}
*xdp_xmit |= VETH_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))
goto err_xdp;
*xdp_xmit |= VETH_XDP_REDIR;
rcu_read_unlock();
goto xdp_xmit;
default:
bpf_warn_invalid_xdp_action(act);
/* fall through */
case XDP_ABORTED:
trace_xdp_exception(rq->dev, xdp_prog, act);
/* fall through */
case XDP_DROP:
goto drop;
}
rcu_read_unlock();
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;
off = xdp.data_end - orig_data_end;
if (off != 0)
__skb_put(skb, off);
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:
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, unsigned int *xdp_xmit,
struct veth_xdp_tx_bq *bq)
{
int i, done = 0, drops = 0, bytes = 0;
for (i = 0; i < budget; i++) {
void *ptr = __ptr_ring_consume(&rq->xdp_ring);
unsigned int xdp_xmit_one = 0;
struct sk_buff *skb;
if (!ptr)
break;
if (veth_is_xdp_frame(ptr)) {
struct xdp_frame *frame = veth_ptr_to_xdp(ptr);
bytes += frame->len;
skb = veth_xdp_rcv_one(rq, frame, &xdp_xmit_one, bq);
} else {
skb = ptr;
bytes += skb->len;
skb = veth_xdp_rcv_skb(rq, skb, &xdp_xmit_one, bq);
}
*xdp_xmit |= xdp_xmit_one;
if (skb)
napi_gro_receive(&rq->xdp_napi, skb);
else if (!xdp_xmit_one)
drops++;
done++;
}
u64_stats_update_begin(&rq->stats.syncp);
rq->stats.xdp_packets += done;
rq->stats.xdp_bytes += bytes;
rq->stats.xdp_drops += drops;
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);
unsigned int xdp_xmit = 0;
struct veth_xdp_tx_bq bq;
int done;
bq.count = 0;
xdp_set_return_frame_no_direct();
done = veth_xdp_rcv(rq, budget, &xdp_xmit, &bq);
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 (xdp_xmit & VETH_XDP_TX)
veth_xdp_flush(rq->dev, &bq);
if (xdp_xmit & VETH_XDP_REDIR)
xdp_do_flush_map();
xdp_clear_return_frame_no_direct();
return done;
}
static int veth_napi_add(struct net_device *dev)
{
struct veth_priv *priv = netdev_priv(dev);
int err, i;
for (i = 0; i < dev->real_num_rx_queues; 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 = 0; i < dev->real_num_rx_queues; i++) {
struct veth_rq *rq = &priv->rq[i];
netif_napi_add(dev, &rq->xdp_napi, veth_poll, NAPI_POLL_WEIGHT);
napi_enable(&rq->xdp_napi);
}
return 0;
err_xdp_ring:
for (i--; i >= 0; i--)
ptr_ring_cleanup(&priv->rq[i].xdp_ring, veth_ptr_free);
return err;
}
static void veth_napi_del(struct net_device *dev)
{
struct veth_priv *priv = netdev_priv(dev);
int i;
for (i = 0; i < dev->real_num_rx_queues; i++) {
struct veth_rq *rq = &priv->rq[i];
napi_disable(&rq->xdp_napi);
napi_hash_del(&rq->xdp_napi);
}
synchronize_net();
for (i = 0; i < dev->real_num_rx_queues; i++) {
struct veth_rq *rq = &priv->rq[i];
netif_napi_del(&rq->xdp_napi);
rq->rx_notify_masked = false;
ptr_ring_cleanup(&rq->xdp_ring, veth_ptr_free);
}
}
static int veth_enable_xdp(struct net_device *dev)
{
struct veth_priv *priv = netdev_priv(dev);
int err, i;
if (!xdp_rxq_info_is_reg(&priv->rq[0].xdp_rxq)) {
for (i = 0; i < dev->real_num_rx_queues; i++) {
struct veth_rq *rq = &priv->rq[i];
err = xdp_rxq_info_reg(&rq->xdp_rxq, dev, i);
if (err < 0)
goto err_rxq_reg;
err = xdp_rxq_info_reg_mem_model(&rq->xdp_rxq,
MEM_TYPE_PAGE_SHARED,
NULL);
if (err < 0)
goto err_reg_mem;
/* Save original mem info as it can be overwritten */
rq->xdp_mem = rq->xdp_rxq.mem;
}
err = veth_napi_add(dev);
if (err)
goto err_rxq_reg;
}
for (i = 0; i < dev->real_num_rx_queues; i++)
rcu_assign_pointer(priv->rq[i].xdp_prog, priv->_xdp_prog);
return 0;
err_reg_mem:
xdp_rxq_info_unreg(&priv->rq[i].xdp_rxq);
err_rxq_reg:
for (i--; i >= 0; i--)
xdp_rxq_info_unreg(&priv->rq[i].xdp_rxq);
return err;
}
static void veth_disable_xdp(struct net_device *dev)
{
struct veth_priv *priv = netdev_priv(dev);
int i;
for (i = 0; i < dev->real_num_rx_queues; i++)
rcu_assign_pointer(priv->rq[i].xdp_prog, NULL);
veth_napi_del(dev);
for (i = 0; i < dev->real_num_rx_queues; i++) {
struct veth_rq *rq = &priv->rq[i];
rq->xdp_rxq.mem = rq->xdp_mem;
xdp_rxq_info_unreg(&rq->xdp_rxq);
}
}
static int veth_open(struct net_device *dev)
{
struct veth_priv *priv = netdev_priv(dev);
struct net_device *peer = rtnl_dereference(priv->peer);
int err;
if (!peer)
return -ENOTCONN;
if (priv->_xdp_prog) {
err = veth_enable_xdp(dev);
if (err)
return err;
}
if (peer->flags & IFF_UP) {
netif_carrier_on(dev);
netif_carrier_on(peer);
}
return 0;
}
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);
if (peer)
netif_carrier_off(peer);
if (priv->_xdp_prog)
veth_disable_xdp(dev);
return 0;
}
static int is_valid_veth_mtu(int mtu)
{
return mtu >= ETH_MIN_MTU && mtu <= ETH_MAX_MTU;
}
static int veth_alloc_queues(struct net_device *dev)
{
struct veth_priv *priv = netdev_priv(dev);
int i;
priv->rq = kcalloc(dev->num_rx_queues, sizeof(*priv->rq), GFP_KERNEL);
if (!priv->rq)
return -ENOMEM;
for (i = 0; i < dev->num_rx_queues; i++) {
priv->rq[i].dev = dev;
u64_stats_init(&priv->rq[i].stats.syncp);
}
return 0;
}
static void veth_free_queues(struct net_device *dev)
{
struct veth_priv *priv = netdev_priv(dev);
kfree(priv->rq);
}
static int veth_dev_init(struct net_device *dev)
{
int err;
dev->lstats = netdev_alloc_pcpu_stats(struct pcpu_lstats);
if (!dev->lstats)
return -ENOMEM;
err = veth_alloc_queues(dev);
if (err) {
free_percpu(dev->lstats);
return err;
}
return 0;
}
static void veth_dev_free(struct net_device *dev)
{
veth_free_queues(dev);
free_percpu(dev->lstats);
}
#ifdef [31mCONFIG_NET_POLL_CONTROLLER[0m
static void veth_poll_controller(struct net_device *dev)
{
/* veth only receives frames when its peer sends one
* Since it has nothing to do with disabling irqs, we are guaranteed
* never to have pending data when we poll for it so
* there is nothing to do here.
*
* We need this though so netpoll recognizes us as an interface that
* supports polling, which enables bridge devices in virt setups to
* still use netconsole
*/
}
#endif /* CONFIG_NET_POLL_CONTROLLER */
static int veth_get_iflink(const struct net_device *dev)
{
struct veth_priv *priv = netdev_priv(dev);
struct net_device *peer;
int iflink;
rcu_read_lock();
peer = rcu_dereference(priv->peer);
iflink = peer ? peer->ifindex : 0;
rcu_read_unlock();
return iflink;
}
static netdev_features_t veth_fix_features(struct net_device *dev,
netdev_features_t features)
{
struct veth_priv *priv = netdev_priv(dev);
struct net_device *peer;
peer = rtnl_dereference(priv->peer);
if (peer) {
struct veth_priv *peer_priv = netdev_priv(peer);
if (peer_priv->_xdp_prog)
features &= ~NETIF_F_GSO_SOFTWARE;
}
return features;
}
static void veth_set_rx_headroom(struct net_device *dev, int new_hr)
{
struct veth_priv *peer_priv, *priv = netdev_priv(dev);
struct net_device *peer;
if (new_hr < 0)
new_hr = 0;
rcu_read_lock();
peer = rcu_dereference(priv->peer);
if (unlikely(!peer))
goto out;
peer_priv = netdev_priv(peer);
priv->requested_headroom = new_hr;
new_hr = max(priv->requested_headroom, peer_priv->requested_headroom);
dev->needed_headroom = new_hr;
peer->needed_headroom = new_hr;
out:
rcu_read_unlock();
}
static int veth_xdp_set(struct net_device *dev, struct bpf_prog *prog,
struct netlink_ext_ack *extack)
{
struct veth_priv *priv = netdev_priv(dev);
struct bpf_prog *old_prog;
struct net_device *peer;
unsigned int max_mtu;
int err;
old_prog = priv->_xdp_prog;
priv->_xdp_prog = prog;
peer = rtnl_dereference(priv->peer);
if (prog) {
if (!peer) {
NL_SET_ERR_MSG_MOD(extack, "Cannot set XDP when peer is detached");
err = -ENOTCONN;
goto err;
}
max_mtu = PAGE_SIZE - VETH_XDP_HEADROOM -
peer->hard_header_len -
SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
if (peer->mtu > max_mtu) {
NL_SET_ERR_MSG_MOD(extack, "Peer MTU is too large to set XDP");
err = -ERANGE;
goto err;
}
if (dev->real_num_rx_queues < peer->real_num_tx_queues) {
NL_SET_ERR_MSG_MOD(extack, "XDP expects number of rx queues not less than peer tx queues");
err = -ENOSPC;
goto err;
}
if (dev->flags & IFF_UP) {
err = veth_enable_xdp(dev);
if (err) {
NL_SET_ERR_MSG_MOD(extack, "Setup for XDP failed");
goto err;
}
}
if (!old_prog) {
peer->hw_features &= ~NETIF_F_GSO_SOFTWARE;
peer->max_mtu = max_mtu;
}
}
if (old_prog) {
if (!prog) {
if (dev->flags & IFF_UP)
veth_disable_xdp(dev);
if (peer) {
peer->hw_features |= NETIF_F_GSO_SOFTWARE;
peer->max_mtu = ETH_MAX_MTU;
}
}
bpf_prog_put(old_prog);
}
if ((!!old_prog ^ !!prog) && peer)
netdev_update_features(peer);
return 0;
err:
priv->_xdp_prog = old_prog;
return err;
}
static u32 veth_xdp_query(struct net_device *dev)
{
struct veth_priv *priv = netdev_priv(dev);
const struct bpf_prog *xdp_prog;
xdp_prog = priv->_xdp_prog;
if (xdp_prog)
return xdp_prog->aux->id;
return 0;
}
static int veth_xdp(struct net_device *dev, struct netdev_bpf *xdp)
{
switch (xdp->command) {
case XDP_SETUP_PROG:
return veth_xdp_set(dev, xdp->prog, xdp->extack);
case XDP_QUERY_PROG:
xdp->prog_id = veth_xdp_query(dev);
return 0;
default:
return -EINVAL;
}
}
static const struct net_device_ops veth_netdev_ops = {
.ndo_init = veth_dev_init,
.ndo_open = veth_open,
.ndo_stop = veth_close,
.ndo_start_xmit = veth_xmit,
.ndo_get_stats64 = veth_get_stats64,
.ndo_set_rx_mode = veth_set_multicast_list,
.ndo_set_mac_address = eth_mac_addr,
#ifdef [31mCONFIG_NET_POLL_CONTROLLER[0m
.ndo_poll_controller = veth_poll_controller,
#endif
.ndo_get_iflink = veth_get_iflink,
.ndo_fix_features = veth_fix_features,
.ndo_features_check = passthru_features_check,
.ndo_set_rx_headroom = veth_set_rx_headroom,
.ndo_bpf = veth_xdp,
.ndo_xdp_xmit = veth_xdp_xmit,
};
#define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HW_CSUM | \
NETIF_F_RXCSUM | NETIF_F_SCTP_CRC | NETIF_F_HIGHDMA | \
NETIF_F_GSO_SOFTWARE | NETIF_F_GSO_ENCAP_ALL | \
NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX | \
NETIF_F_HW_VLAN_STAG_TX | NETIF_F_HW_VLAN_STAG_RX )
static void veth_setup(struct net_device *dev)
{
ether_setup(dev);
dev->priv_flags &= ~IFF_TX_SKB_SHARING;
dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
dev->priv_flags |= IFF_NO_QUEUE;
dev->priv_flags |= IFF_PHONY_HEADROOM;
dev->netdev_ops = &veth_netdev_ops;
dev->ethtool_ops = &veth_ethtool_ops;
dev->features |= NETIF_F_LLTX;
dev->features |= VETH_FEATURES;
dev->vlan_features = dev->features &
~(NETIF_F_HW_VLAN_CTAG_TX |
NETIF_F_HW_VLAN_STAG_TX |
NETIF_F_HW_VLAN_CTAG_RX |
NETIF_F_HW_VLAN_STAG_RX);
dev->needs_free_netdev = true;
dev->priv_destructor = veth_dev_free;
dev->max_mtu = ETH_MAX_MTU;
dev->hw_features = VETH_FEATURES;
dev->hw_enc_features = VETH_FEATURES;
dev->mpls_features = NETIF_F_HW_CSUM | NETIF_F_GSO_SOFTWARE;
}
/*
* netlink interface
*/
static int veth_validate(struct nlattr *tb[], struct nlattr *data[],
struct netlink_ext_ack *extack)
{
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;
}
if (tb[IFLA_MTU]) {
if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU])))
return -EINVAL;
}
return 0;
}
static struct rtnl_link_ops veth_link_ops;
static int veth_newlink(struct net *src_net, struct net_device *dev,
struct nlattr *tb[], struct nlattr *data[],
struct netlink_ext_ack *extack)
{
int err;
struct net_device *peer;
struct veth_priv *priv;
char ifname[IFNAMSIZ];
struct nlattr *peer_tb[IFLA_MAX + 1], **tbp;
unsigned char name_assign_type;
struct ifinfomsg *ifmp;
struct net *net;
/*
* create and register peer first
*/
if (data != NULL && data[VETH_INFO_PEER] != NULL) {
struct nlattr *nla_peer;
nla_peer = data[VETH_INFO_PEER];
ifmp = nla_data(nla_peer);
err = rtnl_nla_parse_ifla(peer_tb,
nla_data(nla_peer) + sizeof(struct ifinfomsg),
nla_len(nla_peer) - sizeof(struct ifinfomsg),
NULL);
if (err < 0)
return err;
err = veth_validate(peer_tb, NULL, extack);
if (err < 0)
return err;
tbp = peer_tb;
} else {
ifmp = NULL;
tbp = tb;
}
if (ifmp && tbp[IFLA_IFNAME]) {
nla_strlcpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);
name_assign_type = NET_NAME_USER;
} else {
snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
name_assign_type = NET_NAME_ENUM;
}
net = rtnl_link_get_net(src_net, tbp);
if (IS_ERR(net))
return PTR_ERR(net);
peer = rtnl_create_link(net, ifname, name_assign_type,
&veth_link_ops, tbp, extack);
if (IS_ERR(peer)) {
put_net(net);
return PTR_ERR(peer);
}
if (!ifmp || !tbp[IFLA_ADDRESS])
eth_hw_addr_random(peer);
if (ifmp && (dev->ifindex != 0))
peer->ifindex = ifmp->ifi_index;
peer->gso_max_size = dev->gso_max_size;
peer->gso_max_segs = dev->gso_max_segs;
err = register_netdevice(peer);
put_net(net);
net = NULL;
if (err < 0)
goto err_register_peer;
netif_carrier_off(peer);
err = rtnl_configure_link(peer, ifmp);
if (err < 0)
goto err_configure_peer;
/*
* register dev last
*
* note, that since we've registered new device the dev's name
* should be re-allocated
*/
if (tb[IFLA_ADDRESS] == NULL)
eth_hw_addr_random(dev);
if (tb[IFLA_IFNAME])
nla_strlcpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);
else
snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");
err = register_netdevice(dev);
if (err < 0)
goto err_register_dev;
netif_carrier_off(dev);
/*
* tie the deviced together
*/
priv = netdev_priv(dev);
rcu_assign_pointer(priv->peer, peer);
priv = netdev_priv(peer);
rcu_assign_pointer(priv->peer, dev);
return 0;
err_register_dev:
/* nothing to do */
err_configure_peer:
unregister_netdevice(peer);
return err;
err_register_peer:
free_netdev(peer);
return err;
}
static void veth_dellink(struct net_device *dev, struct list_head *head)
{
struct veth_priv *priv;
struct net_device *peer;
priv = netdev_priv(dev);
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);
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] = {
[VETH_INFO_PEER] = { .len = sizeof(struct ifinfomsg) },
};
static struct net *veth_get_link_net(const struct net_device *dev)
{
struct veth_priv *priv = netdev_priv(dev);
struct net_device *peer = rtnl_dereference(priv->peer);
return peer ? dev_net(peer) : dev_net(dev);
}
static struct rtnl_link_ops veth_link_ops = {
.kind = DRV_NAME,
.priv_size = sizeof(struct veth_priv),
.setup = veth_setup,
.validate = veth_validate,
.newlink = veth_newlink,
.dellink = veth_dellink,
.policy = veth_policy,
.maxtype = VETH_INFO_MAX,
.get_link_net = veth_get_link_net,
};
/*
* init/fini
*/
static __init int veth_init(void)
{
return rtnl_link_register(&veth_link_ops);
}
static __exit void veth_exit(void)
{
rtnl_link_unregister(&veth_link_ops);
}
module_init(veth_init);
module_exit(veth_exit);
MODULE_DESCRIPTION("Virtual Ethernet Tunnel");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS_RTNL_LINK(DRV_NAME);