// SPDX-License-Identifier: GPL-2.0
/* XDP sockets
*
* AF_XDP sockets allows a channel between XDP programs and userspace
* applications.
* Copyright(c) 2018 Intel Corporation.
*
* Author(s): Björn Töpel <[email protected]>
* Magnus Karlsson <[email protected]>
*/
#define pr_fmt(fmt) "AF_XDP: %s: " fmt, __func__
#include <linux/if_xdp.h>
#include <linux/init.h>
#include <linux/sched/mm.h>
#include <linux/sched/signal.h>
#include <linux/sched/task.h>
#include <linux/socket.h>
#include <linux/file.h>
#include <linux/uaccess.h>
#include <linux/net.h>
#include <linux/netdevice.h>
#include <linux/rculist.h>
#include <linux/vmalloc.h>
#include <net/xdp_sock_drv.h>
#include <net/busy_poll.h>
#include <net/netdev_rx_queue.h>
#include <net/xdp.h>
#include "xsk_queue.h"
#include "xdp_umem.h"
#include "xsk.h"
#define TX_BATCH_SIZE 32
#define MAX_PER_SOCKET_BUDGET (TX_BATCH_SIZE)
void xsk_set_rx_need_wakeup(struct xsk_buff_pool *pool)
{
if (pool->cached_need_wakeup & XDP_WAKEUP_RX)
return;
pool->fq->ring->flags |= XDP_RING_NEED_WAKEUP;
pool->cached_need_wakeup |= XDP_WAKEUP_RX;
}
EXPORT_SYMBOL(xsk_set_rx_need_wakeup);
void xsk_set_tx_need_wakeup(struct xsk_buff_pool *pool)
{
struct xdp_sock *xs;
if (pool->cached_need_wakeup & XDP_WAKEUP_TX)
return;
rcu_read_lock();
list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) {
xs->tx->ring->flags |= XDP_RING_NEED_WAKEUP;
}
rcu_read_unlock();
pool->cached_need_wakeup |= XDP_WAKEUP_TX;
}
EXPORT_SYMBOL(xsk_set_tx_need_wakeup);
void xsk_clear_rx_need_wakeup(struct xsk_buff_pool *pool)
{
if (!(pool->cached_need_wakeup & XDP_WAKEUP_RX))
return;
pool->fq->ring->flags &= ~XDP_RING_NEED_WAKEUP;
pool->cached_need_wakeup &= ~XDP_WAKEUP_RX;
}
EXPORT_SYMBOL(xsk_clear_rx_need_wakeup);
void xsk_clear_tx_need_wakeup(struct xsk_buff_pool *pool)
{
struct xdp_sock *xs;
if (!(pool->cached_need_wakeup & XDP_WAKEUP_TX))
return;
rcu_read_lock();
list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) {
xs->tx->ring->flags &= ~XDP_RING_NEED_WAKEUP;
}
rcu_read_unlock();
pool->cached_need_wakeup &= ~XDP_WAKEUP_TX;
}
EXPORT_SYMBOL(xsk_clear_tx_need_wakeup);
bool xsk_uses_need_wakeup(struct xsk_buff_pool *pool)
{
return pool->uses_need_wakeup;
}
EXPORT_SYMBOL(xsk_uses_need_wakeup);
struct xsk_buff_pool *xsk_get_pool_from_qid(struct net_device *dev,
u16 queue_id)
{
if (queue_id < dev->real_num_rx_queues)
return dev->_rx[queue_id].pool;
if (queue_id < dev->real_num_tx_queues)
return dev->_tx[queue_id].pool;
return NULL;
}
EXPORT_SYMBOL(xsk_get_pool_from_qid);
void xsk_clear_pool_at_qid(struct net_device *dev, u16 queue_id)
{
if (queue_id < dev->num_rx_queues)
dev->_rx[queue_id].pool = NULL;
if (queue_id < dev->num_tx_queues)
dev->_tx[queue_id].pool = NULL;
}
/* The buffer pool is stored both in the _rx struct and the _tx struct as we do
* not know if the device has more tx queues than rx, or the opposite.
* This might also change during run time.
*/
int xsk_reg_pool_at_qid(struct net_device *dev, struct xsk_buff_pool *pool,
u16 queue_id)
{
if (queue_id >= max_t(unsigned int,
dev->real_num_rx_queues,
dev->real_num_tx_queues))
return -EINVAL;
if (queue_id < dev->real_num_rx_queues)
dev->_rx[queue_id].pool = pool;
if (queue_id < dev->real_num_tx_queues)
dev->_tx[queue_id].pool = pool;
return 0;
}
static int __xsk_rcv_zc(struct xdp_sock *xs, struct xdp_buff_xsk *xskb, u32 len,
u32 flags)
{
u64 addr;
int err;
addr = xp_get_handle(xskb);
err = xskq_prod_reserve_desc(xs->rx, addr, len, flags);
if (err) {
xs->rx_queue_full++;
return err;
}
xp_release(xskb);
return 0;
}
static int xsk_rcv_zc(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len)
{
struct xdp_buff_xsk *xskb = container_of(xdp, struct xdp_buff_xsk, xdp);
u32 frags = xdp_buff_has_frags(xdp);
struct xdp_buff_xsk *pos, *tmp;
struct list_head *xskb_list;
u32 contd = 0;
int err;
if (frags)
contd = XDP_PKT_CONTD;
err = __xsk_rcv_zc(xs, xskb, len, contd);
if (err)
goto err;
if (likely(!frags))
return 0;
xskb_list = &xskb->pool->xskb_list;
list_for_each_entry_safe(pos, tmp, xskb_list, xskb_list_node) {
if (list_is_singular(xskb_list))
contd = 0;
len = pos->xdp.data_end - pos->xdp.data;
err = __xsk_rcv_zc(xs, pos, len, contd);
if (err)
goto err;
list_del(&pos->xskb_list_node);
}
return 0;
err:
xsk_buff_free(xdp);
return err;
}
static void *xsk_copy_xdp_start(struct xdp_buff *from)
{
if (unlikely(xdp_data_meta_unsupported(from)))
return from->data;
else
return from->data_meta;
}
static u32 xsk_copy_xdp(void *to, void **from, u32 to_len,
u32 *from_len, skb_frag_t **frag, u32 rem)
{
u32 copied = 0;
while (1) {
u32 copy_len = min_t(u32, *from_len, to_len);
memcpy(to, *from, copy_len);
copied += copy_len;
if (rem == copied)
return copied;
if (*from_len == copy_len) {
*from = skb_frag_address(*frag);
*from_len = skb_frag_size((*frag)++);
} else {
*from += copy_len;
*from_len -= copy_len;
}
if (to_len == copy_len)
return copied;
to_len -= copy_len;
to += copy_len;
}
}
static int __xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len)
{
u32 frame_size = xsk_pool_get_rx_frame_size(xs->pool);
void *copy_from = xsk_copy_xdp_start(xdp), *copy_to;
u32 from_len, meta_len, rem, num_desc;
struct xdp_buff_xsk *xskb;
struct xdp_buff *xsk_xdp;
skb_frag_t *frag;
from_len = xdp->data_end - copy_from;
meta_len = xdp->data - copy_from;
rem = len + meta_len;
if (len <= frame_size && !xdp_buff_has_frags(xdp)) {
int err;
xsk_xdp = xsk_buff_alloc(xs->pool);
if (!xsk_xdp) {
xs->rx_dropped++;
return -ENOMEM;
}
memcpy(xsk_xdp->data - meta_len, copy_from, rem);
xskb = container_of(xsk_xdp, struct xdp_buff_xsk, xdp);
err = __xsk_rcv_zc(xs, xskb, len, 0);
if (err) {
xsk_buff_free(xsk_xdp);
return err;
}
return 0;
}
num_desc = (len - 1) / frame_size + 1;
if (!xsk_buff_can_alloc(xs->pool, num_desc)) {
xs->rx_dropped++;
return -ENOMEM;
}
if (xskq_prod_nb_free(xs->rx, num_desc) < num_desc) {
xs->rx_queue_full++;
return -ENOBUFS;
}
if (xdp_buff_has_frags(xdp)) {
struct skb_shared_info *sinfo;
sinfo = xdp_get_shared_info_from_buff(xdp);
frag = &sinfo->frags[0];
}
do {
u32 to_len = frame_size + meta_len;
u32 copied;
xsk_xdp = xsk_buff_alloc(xs->pool);
copy_to = xsk_xdp->data - meta_len;
copied = xsk_copy_xdp(copy_to, ©_from, to_len, &from_len, &frag, rem);
rem -= copied;
xskb = container_of(xsk_xdp, struct xdp_buff_xsk, xdp);
__xsk_rcv_zc(xs, xskb, copied - meta_len, rem ? XDP_PKT_CONTD : 0);
meta_len = 0;
} while (rem);
return 0;
}
static bool xsk_tx_writeable(struct xdp_sock *xs)
{
if (xskq_cons_present_entries(xs->tx) > xs->tx->nentries / 2)
return false;
return true;
}
static bool xsk_is_bound(struct xdp_sock *xs)
{
if (READ_ONCE(xs->state) == XSK_BOUND) {
/* Matches smp_wmb() in bind(). */
smp_rmb();
return true;
}
return false;
}
static int xsk_rcv_check(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len)
{
if (!xsk_is_bound(xs))
return -ENXIO;
if (xs->dev != xdp->rxq->dev || xs->queue_id != xdp->rxq->queue_index)
return -EINVAL;
if (len > xsk_pool_get_rx_frame_size(xs->pool) && !xs->sg) {
xs->rx_dropped++;
return -ENOSPC;
}
sk_mark_napi_id_once_xdp(&xs->sk, xdp);
return 0;
}
static void xsk_flush(struct xdp_sock *xs)
{
xskq_prod_submit(xs->rx);
__xskq_cons_release(xs->pool->fq);
sock_def_readable(&xs->sk);
}
int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
{
u32 len = xdp_get_buff_len(xdp);
int err;
spin_lock_bh(&xs->rx_lock);
err = xsk_rcv_check(xs, xdp, len);
if (!err) {
err = __xsk_rcv(xs, xdp, len);
xsk_flush(xs);
}
spin_unlock_bh(&xs->rx_lock);
return err;
}
static int xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
{
u32 len = xdp_get_buff_len(xdp);
int err;
err = xsk_rcv_check(xs, xdp, len);
if (err)
return err;
if (xdp->rxq->mem.type == MEM_TYPE_XSK_BUFF_POOL) {
len = xdp->data_end - xdp->data;
return xsk_rcv_zc(xs, xdp, len);
}
err = __xsk_rcv(xs, xdp, len);
if (!err)
xdp_return_buff(xdp);
return err;
}
int __xsk_map_redirect(struct xdp_sock *xs, struct xdp_buff *xdp)
{
int err;
err = xsk_rcv(xs, xdp);
if (err)
return err;
if (!xs->flush_node.prev) {
struct list_head *flush_list = bpf_net_ctx_get_xskmap_flush_list();
list_add(&xs->flush_node, flush_list);
}
return 0;
}
void __xsk_map_flush(struct list_head *flush_list)
{
struct xdp_sock *xs, *tmp;
list_for_each_entry_safe(xs, tmp, flush_list, flush_node) {
xsk_flush(xs);
__list_del_clearprev(&xs->flush_node);
}
}
void xsk_tx_completed(struct xsk_buff_pool *pool, u32 nb_entries)
{
xskq_prod_submit_n(pool->cq, nb_entries);
}
EXPORT_SYMBOL(xsk_tx_completed);
void xsk_tx_release(struct xsk_buff_pool *pool)
{
struct xdp_sock *xs;
rcu_read_lock();
list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) {
__xskq_cons_release(xs->tx);
if (xsk_tx_writeable(xs))
xs->sk.sk_write_space(&xs->sk);
}
rcu_read_unlock();
}
EXPORT_SYMBOL(xsk_tx_release);
bool xsk_tx_peek_desc(struct xsk_buff_pool *pool, struct xdp_desc *desc)
{
bool budget_exhausted = false;
struct xdp_sock *xs;
rcu_read_lock();
again:
list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) {
if (xs->tx_budget_spent >= MAX_PER_SOCKET_BUDGET) {
budget_exhausted = true;
continue;
}
if (!xskq_cons_peek_desc(xs->tx, desc, pool)) {
if (xskq_has_descs(xs->tx))
xskq_cons_release(xs->tx);
continue;
}
xs->tx_budget_spent++;
/* This is the backpressure mechanism for the Tx path.
* Reserve space in the completion queue and only proceed
* if there is space in it. This avoids having to implement
* any buffering in the Tx path.
*/
if (xskq_prod_reserve_addr(pool->cq, desc->addr))
goto out;
xskq_cons_release(xs->tx);
rcu_read_unlock();
return true;
}
if (budget_exhausted) {
list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list)
xs->tx_budget_spent = 0;
budget_exhausted = false;
goto again;
}
out:
rcu_read_unlock();
return false;
}
EXPORT_SYMBOL(xsk_tx_peek_desc);
static u32 xsk_tx_peek_release_fallback(struct xsk_buff_pool *pool, u32 max_entries)
{
struct xdp_desc *descs = pool->tx_descs;
u32 nb_pkts = 0;
while (nb_pkts < max_entries && xsk_tx_peek_desc(pool, &descs[nb_pkts]))
nb_pkts++;
xsk_tx_release(pool);
return nb_pkts;
}
u32 xsk_tx_peek_release_desc_batch(struct xsk_buff_pool *pool, u32 nb_pkts)
{
struct xdp_sock *xs;
rcu_read_lock();
if (!list_is_singular(&pool->xsk_tx_list)) {
/* Fallback to the non-batched version */
rcu_read_unlock();
return xsk_tx_peek_release_fallback(pool, nb_pkts);
}
xs = list_first_or_null_rcu(&pool->xsk_tx_list, struct xdp_sock, tx_list);
if (!xs) {
nb_pkts = 0;
goto out;
}
nb_pkts = xskq_cons_nb_entries(xs->tx, nb_pkts);
/* This is the backpressure mechanism for the Tx path. Try to
* reserve space in the completion queue for all packets, but
* if there are fewer slots available, just process that many
* packets. This avoids having to implement any buffering in
* the Tx path.
*/
nb_pkts = xskq_prod_nb_free(pool->cq, nb_pkts);
if (!nb_pkts)
goto out;
nb_pkts = xskq_cons_read_desc_batch(xs->tx, pool, nb_pkts);
if (!nb_pkts) {
xs->tx->queue_empty_descs++;
goto out;
}
__xskq_cons_release(xs->tx);
xskq_prod_write_addr_batch(pool->cq, pool->tx_descs, nb_pkts);
xs->sk.sk_write_space(&xs->sk);
out:
rcu_read_unlock();
return nb_pkts;
}
EXPORT_SYMBOL(xsk_tx_peek_release_desc_batch);
static int xsk_wakeup(struct xdp_sock *xs, u8 flags)
{
struct net_device *dev = xs->dev;
return dev->netdev_ops->ndo_xsk_wakeup(dev, xs->queue_id, flags);
}
static int xsk_cq_reserve_addr_locked(struct xdp_sock *xs, u64 addr)
{
unsigned long flags;
int ret;
spin_lock_irqsave(&xs->pool->cq_lock, flags);
ret = xskq_prod_reserve_addr(xs->pool->cq, addr);
spin_unlock_irqrestore(&xs->pool->cq_lock, flags);
return ret;
}
static void xsk_cq_submit_locked(struct xdp_sock *xs, u32 n)
{
unsigned long flags;
spin_lock_irqsave(&xs->pool->cq_lock, flags);
xskq_prod_submit_n(xs->pool->cq, n);
spin_unlock_irqrestore(&xs->pool->cq_lock, flags);
}
static void xsk_cq_cancel_locked(struct xdp_sock *xs, u32 n)
{
unsigned long flags;
spin_lock_irqsave(&xs->pool->cq_lock, flags);
xskq_prod_cancel_n(xs->pool->cq, n);
spin_unlock_irqrestore(&xs->pool->cq_lock, flags);
}
static u32 xsk_get_num_desc(struct sk_buff *skb)
{
return skb ? (long)skb_shinfo(skb)->destructor_arg : 0;
}
static void xsk_destruct_skb(struct sk_buff *skb)
{
struct xsk_tx_metadata_compl *compl = &skb_shinfo(skb)->xsk_meta;
if (compl->tx_timestamp) {
/* sw completion timestamp, not a real one */
*compl->tx_timestamp = ktime_get_tai_fast_ns();
}
xsk_cq_submit_locked(xdp_sk(skb->sk), xsk_get_num_desc(skb));
sock_wfree(skb);
}
static void xsk_set_destructor_arg(struct sk_buff *skb)
{
long num = xsk_get_num_desc(xdp_sk(skb->sk)->skb) + 1;
skb_shinfo(skb)->destructor_arg = (void *)num;
}
static void xsk_consume_skb(struct sk_buff *skb)
{
struct xdp_sock *xs = xdp_sk(skb->sk);
skb->destructor = sock_wfree;
xsk_cq_cancel_locked(xs, xsk_get_num_desc(skb));
/* Free skb without triggering the perf drop trace */
consume_skb(skb);
xs->skb = NULL;
}
static void xsk_drop_skb(struct sk_buff *skb)
{
xdp_sk(skb->sk)->tx->invalid_descs += xsk_get_num_desc(skb);
xsk_consume_skb(skb);
}
static struct sk_buff *xsk_build_skb_zerocopy(struct xdp_sock *xs,
struct xdp_desc *desc)
{
struct xsk_buff_pool *pool = xs->pool;
u32 hr, len, ts, offset, copy, copied;
struct sk_buff *skb = xs->skb;
struct page *page;
void *buffer;
int err, i;
u64 addr;
if (!skb) {
hr = max(NET_SKB_PAD, L1_CACHE_ALIGN(xs->dev->needed_headroom));
skb = sock_alloc_send_skb(&xs->sk, hr, 1, &err);
if (unlikely(!skb))
return ERR_PTR(err);
skb_reserve(skb, hr);
}
addr = desc->addr;
len = desc->len;
ts = pool->unaligned ? len : pool->chunk_size;
buffer = xsk_buff_raw_get_data(pool, addr);
offset = offset_in_page(buffer);
addr = buffer - pool->addrs;
for (copied = 0, i = skb_shinfo(skb)->nr_frags; copied < len; i++) {
if (unlikely(i >= MAX_SKB_FRAGS))
return ERR_PTR(-EOVERFLOW);
page = pool->umem->pgs[addr >> PAGE_SHIFT];
get_page(page);
copy = min_t(u32, PAGE_SIZE - offset, len - copied);
skb_fill_page_desc(skb, i, page, offset, copy);
copied += copy;
addr += copy;
offset = 0;
}
skb->len += len;
skb->data_len += len;
skb->truesize += ts;
refcount_add(ts, &xs->sk.sk_wmem_alloc);
return skb;
}
static struct sk_buff *xsk_build_skb(struct xdp_sock *xs,
struct xdp_desc *desc)
{
struct xsk_tx_metadata *meta = NULL;
struct net_device *dev = xs->dev;
struct sk_buff *skb = xs->skb;
bool first_frag = false;
int err;
if (dev->priv_flags & IFF_TX_SKB_NO_LINEAR) {
skb = xsk_build_skb_zerocopy(xs, desc);
if (IS_ERR(skb)) {
err = PTR_ERR(skb);
goto free_err;
}
} else {
u32 hr, tr, len;
void *buffer;
buffer = xsk_buff_raw_get_data(xs->pool, desc->addr);
len = desc->len;
if (!skb) {
hr = max(NET_SKB_PAD, L1_CACHE_ALIGN(dev->needed_headroom));
tr = dev->needed_tailroom;
skb = sock_alloc_send_skb(&xs->sk, hr + len + tr, 1, &err);
if (unlikely(!skb))
goto free_err;
skb_reserve(skb, hr);
skb_put(skb, len);
err = skb_store_bits(skb, 0, buffer, len);
if (unlikely(err)) {
kfree_skb(skb);
goto free_err;
}
first_frag = true;
} else {
int nr_frags = skb_shinfo(skb)->nr_frags;
struct page *page;
u8 *vaddr;
if (unlikely(nr_frags == (MAX_SKB_FRAGS - 1) && xp_mb_desc(desc))) {
err = -EOVERFLOW;
goto free_err;
}
page = alloc_page(xs->sk.sk_allocation);
if (unlikely(!page)) {
err = -EAGAIN;
goto free_err;
}
vaddr = kmap_local_page(page);
memcpy(vaddr, buffer, len);
kunmap_local(vaddr);
skb_add_rx_frag(skb, nr_frags, page, 0, len, PAGE_SIZE);
refcount_add(PAGE_SIZE, &xs->sk.sk_wmem_alloc);
}
if (first_frag && desc->options & XDP_TX_METADATA) {
if (unlikely(xs->pool->tx_metadata_len == 0)) {
err = -EINVAL;
goto free_err;
}
meta = buffer - xs->pool->tx_metadata_len;
if (unlikely(!xsk_buff_valid_tx_metadata(meta))) {
err = -EINVAL;
goto free_err;
}
if (meta->flags & XDP_TXMD_FLAGS_CHECKSUM) {
if (unlikely(meta->request.csum_start +
meta->request.csum_offset +
sizeof(__sum16) > len)) {
err = -EINVAL;
goto free_err;
}
skb->csum_start = hr + meta->request.csum_start;
skb->csum_offset = meta->request.csum_offset;
skb->ip_summed = CHECKSUM_PARTIAL;
if (unlikely(xs->pool->tx_sw_csum)) {
err = skb_checksum_help(skb);
if (err)
goto free_err;
}
}
}
}
skb->dev = dev;
skb->priority = READ_ONCE(xs->sk.sk_priority);
skb->mark = READ_ONCE(xs->sk.sk_mark);
skb->destructor = xsk_destruct_skb;
xsk_tx_metadata_to_compl(meta, &skb_shinfo(skb)->xsk_meta);
xsk_set_destructor_arg(skb);
return skb;
free_err:
if (err == -EOVERFLOW) {
/* Drop the packet */
xsk_set_destructor_arg(xs->skb);
xsk_drop_skb(xs->skb);
xskq_cons_release(xs->tx);
} else {
/* Let application retry */
xsk_cq_cancel_locked(xs, 1);
}
return ERR_PTR(err);
}
static int __xsk_generic_xmit(struct sock *sk)
{
struct xdp_sock *xs = xdp_sk(sk);
u32 max_batch = TX_BATCH_SIZE;
bool sent_frame = false;
struct xdp_desc desc;
struct sk_buff *skb;
int err = 0;
mutex_lock(&xs->mutex);
/* Since we dropped the RCU read lock, the socket state might have changed. */
if (unlikely(!xsk_is_bound(xs))) {
err = -ENXIO;
goto out;
}
if (xs->queue_id >= xs->dev->real_num_tx_queues)
goto out;
while (xskq_cons_peek_desc(xs->tx, &desc, xs->pool)) {
if (max_batch-- == 0) {
err = -EAGAIN;
goto out;
}
/* This is the backpressure mechanism for the Tx path.
* Reserve space in the completion queue and only proceed
* if there is space in it. This avoids having to implement
* any buffering in the Tx path.
*/
if (xsk_cq_reserve_addr_locked(xs, desc.addr))
goto out;
skb = xsk_build_skb(xs, &desc);
if (IS_ERR(skb)) {
err = PTR_ERR(skb);
if (err != -EOVERFLOW)
goto out;
err = 0;
continue;
}
xskq_cons_release(xs->tx);
if (xp_mb_desc(&desc)) {
xs->skb = skb;
continue;
}
err = __dev_direct_xmit(skb, xs->queue_id);
if (err == NETDEV_TX_BUSY) {
/* Tell user-space to retry the send */
xskq_cons_cancel_n(xs->tx, xsk_get_num_desc(skb));
xsk_consume_skb(skb);
err = -EAGAIN;
goto out;
}
/* Ignore NET_XMIT_CN as packet might have been sent */
if (err == NET_XMIT_DROP) {
/* SKB completed but not sent */
err = -EBUSY;
xs->skb = NULL;
goto out;
}
sent_frame = true;
xs->skb = NULL;
}
if (xskq_has_descs(xs->tx)) {
if (xs->skb)
xsk_drop_skb(xs->skb);
xskq_cons_release(xs->tx);
}
out:
if (sent_frame)
if (xsk_tx_writeable(xs))
sk->sk_write_space(sk);
mutex_unlock(&xs->mutex);
return err;
}
static int xsk_generic_xmit(struct sock *sk)
{
int ret;
/* Drop the RCU lock since the SKB path might sleep. */
rcu_read_unlock();
ret = __xsk_generic_xmit(sk);
/* Reaquire RCU lock before going into common code. */
rcu_read_lock();
return ret;
}
static bool xsk_no_wakeup(struct sock *sk)
{
#ifdef CONFIG_NET_RX_BUSY_POLL
/* Prefer busy-polling, skip the wakeup. */
return READ_ONCE(sk->sk_prefer_busy_poll) && READ_ONCE(sk->sk_ll_usec) &&
READ_ONCE(sk->sk_napi_id) >= MIN_NAPI_ID;
#else
return false;
#endif
}
static int xsk_check_common(struct xdp_sock *xs)
{
if (unlikely(!xsk_is_bound(xs)))
return -ENXIO;
if (unlikely(!(xs->dev->flags & IFF_UP)))
return -ENETDOWN;
return 0;
}
static int __xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len)
{
bool need_wait = !(m->msg_flags & MSG_DONTWAIT);
struct sock *sk = sock->sk;
struct xdp_sock *xs = xdp_sk(sk);
struct xsk_buff_pool *pool;
int err;
err = xsk_check_common(xs);
if (err)
return err;
if (unlikely(need_wait))
return -EOPNOTSUPP;
if (unlikely(!xs->tx))
return -ENOBUFS;
if (sk_can_busy_loop(sk)) {
if (xs->zc)
__sk_mark_napi_id_once(sk, xsk_pool_get_napi_id(xs->pool));
sk_busy_loop(sk, 1); /* only support non-blocking sockets */
}
if (xs->zc && xsk_no_wakeup(sk))
return 0;
pool = xs->pool;
if (pool->cached_need_wakeup & XDP_WAKEUP_TX) {
if (xs->zc)
return xsk_wakeup(xs, XDP_WAKEUP_TX);
return xsk_generic_xmit(sk);
}
return 0;
}
static int xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len)
{
int ret;
rcu_read_lock();
ret = __xsk_sendmsg(sock, m, total_len);
rcu_read_unlock();
return ret;
}
static int __xsk_recvmsg(struct socket *sock, struct msghdr *m, size_t len, int flags)
{
bool need_wait = !(flags & MSG_DONTWAIT);
struct sock *sk = sock->sk;
struct xdp_sock *xs = xdp_sk(sk);
int err;
err = xsk_check_common(xs);
if (err)
return err;
if (unlikely(!xs->rx))
return -ENOBUFS;
if (unlikely(need_wait))
return -EOPNOTSUPP;
if (sk_can_busy_loop(sk))
sk_busy_loop(sk, 1); /* only support non-blocking sockets */
if (xsk_no_wakeup(sk))
return 0;
if (xs->pool->cached_need_wakeup & XDP_WAKEUP_RX && xs->zc)
return xsk_wakeup(xs, XDP_WAKEUP_RX);
return 0;
}
static int xsk_recvmsg(struct socket *sock, struct msghdr *m, size_t len, int flags)
{
int ret;
rcu_read_lock();
ret = __xsk_recvmsg(sock, m, len, flags);
rcu_read_unlock();
return ret;
}
static __poll_t xsk_poll(struct file *file, struct socket *sock,
struct poll_table_struct *wait)
{
__poll_t mask = 0;
struct sock *sk = sock->sk;
struct xdp_sock *xs = xdp_sk(sk);
struct xsk_buff_pool *pool;
sock_poll_wait(file, sock, wait);
rcu_read_lock();
if (xsk_check_common(xs))
goto out;
pool = xs->pool;
if (pool->cached_need_wakeup) {
if (xs->zc)
xsk_wakeup(xs, pool->cached_need_wakeup);
else if (xs->tx)
/* Poll needs to drive Tx also in copy mode */
xsk_generic_xmit(sk);
}
if (xs->rx && !xskq_prod_is_empty(xs->rx))
mask |= EPOLLIN | EPOLLRDNORM;
if (xs->tx && xsk_tx_writeable(xs))
mask |= EPOLLOUT | EPOLLWRNORM;
out:
rcu_read_unlock();
return mask;
}
static int xsk_init_queue(u32 entries, struct xsk_queue **queue,
bool umem_queue)
{
struct xsk_queue *q;
if (entries == 0 || *queue || !is_power_of_2(entries))
return -EINVAL;
q = xskq_create(entries, umem_queue);
if (!q)
return -ENOMEM;
/* Make sure queue is ready before it can be seen by others */
smp_wmb();
WRITE_ONCE(*queue, q);
return 0;
}
static void xsk_unbind_dev(struct xdp_sock *xs)
{
struct net_device *dev = xs->dev;
if (xs->state != XSK_BOUND)
return;
WRITE_ONCE(xs->state, XSK_UNBOUND);
/* Wait for driver to stop using the xdp socket. */
xp_del_xsk(xs->pool, xs);
synchronize_net();
dev_put(dev);
}
static struct xsk_map *xsk_get_map_list_entry(struct xdp_sock *xs,
struct xdp_sock __rcu ***map_entry)
{
struct xsk_map *map = NULL;
struct xsk_map_node *node;
*map_entry = NULL;
spin_lock_bh(&xs->map_list_lock);
node = list_first_entry_or_null(&xs->map_list, struct xsk_map_node,
node);
if (node) {
bpf_map_inc(&node->map->map);
map = node->map;
*map_entry = node->map_entry;
}
spin_unlock_bh(&xs->map_list_lock);
return map;
}
static void xsk_delete_from_maps(struct xdp_sock *xs)
{
/* This function removes the current XDP socket from all the
* maps it resides in. We need to take extra care here, due to
* the two locks involved. Each map has a lock synchronizing
* updates to the entries, and each socket has a lock that
* synchronizes access to the list of maps (map_list). For
* deadlock avoidance the locks need to be taken in the order
* "map lock"->"socket map list lock". We start off by
* accessing the socket map list, and take a reference to the
* map to guarantee existence between the
* xsk_get_map_list_entry() and xsk_map_try_sock_delete()
* calls. Then we ask the map to remove the socket, which
* tries to remove the socket from the map. Note that there
* might be updates to the map between
* xsk_get_map_list_entry() and xsk_map_try_sock_delete().
*/
struct xdp_sock __rcu **map_entry = NULL;
struct xsk_map *map;
while ((map = xsk_get_map_list_entry(xs, &map_entry))) {
xsk_map_try_sock_delete(map, xs, map_entry);
bpf_map_put(&map->map);
}
}
static int xsk_release(struct socket *sock)
{
struct sock *sk = sock->sk;
struct xdp_sock *xs = xdp_sk(sk);
struct net *net;
if (!sk)
return 0;
net = sock_net(sk);
if (xs->skb)
xsk_drop_skb(xs->skb);
mutex_lock(&net->xdp.lock);
sk_del_node_init_rcu(sk);
mutex_unlock(&net->xdp.lock);
sock_prot_inuse_add(net, sk->sk_prot, -1);
xsk_delete_from_maps(xs);
mutex_lock(&xs->mutex);
xsk_unbind_dev(xs);
mutex_unlock(&xs->mutex);
xskq_destroy(xs->rx);
xskq_destroy(xs->tx);
xskq_destroy(xs->fq_tmp);
xskq_destroy(xs->cq_tmp);
sock_orphan(sk);
sock->sk = NULL;
sock_put(sk);
return 0;
}
static struct socket *xsk_lookup_xsk_from_fd(int fd)
{
struct socket *sock;
int err;
sock = sockfd_lookup(fd, &err);
if (!sock)
return ERR_PTR(-ENOTSOCK);
if (sock->sk->sk_family != PF_XDP) {
sockfd_put(sock);
return ERR_PTR(-ENOPROTOOPT);
}
return sock;
}
static bool xsk_validate_queues(struct xdp_sock *xs)
{
return xs->fq_tmp && xs->cq_tmp;
}
static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
{
struct sockaddr_xdp *sxdp = (struct sockaddr_xdp *)addr;
struct sock *sk = sock->sk;
struct xdp_sock *xs = xdp_sk(sk);
struct net_device *dev;
int bound_dev_if;
u32 flags, qid;
int err = 0;
if (addr_len < sizeof(struct sockaddr_xdp))
return -EINVAL;
if (sxdp->sxdp_family != AF_XDP)
return -EINVAL;
flags = sxdp->sxdp_flags;
if (flags & ~(XDP_SHARED_UMEM | XDP_COPY | XDP_ZEROCOPY |
XDP_USE_NEED_WAKEUP | XDP_USE_SG))
return -EINVAL;
bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
if (bound_dev_if && bound_dev_if != sxdp->sxdp_ifindex)
return -EINVAL;
rtnl_lock();
mutex_lock(&xs->mutex);
if (xs->state != XSK_READY) {
err = -EBUSY;
goto out_release;
}
dev = dev_get_by_index(sock_net(sk), sxdp->sxdp_ifindex);
if (!dev) {
err = -ENODEV;
goto out_release;
}
if (!xs->rx && !xs->tx) {
err = -EINVAL;
goto out_unlock;
}
qid = sxdp->sxdp_queue_id;
if (flags & XDP_SHARED_UMEM) {
struct xdp_sock *umem_xs;
struct socket *sock;
if ((flags & XDP_COPY) || (flags & XDP_ZEROCOPY) ||
(flags & XDP_USE_NEED_WAKEUP) || (flags & XDP_USE_SG)) {
/* Cannot specify flags for shared sockets. */
err = -EINVAL;
goto out_unlock;
}
if (xs->umem) {
/* We have already our own. */
err = -EINVAL;
goto out_unlock;
}
sock = xsk_lookup_xsk_from_fd(sxdp->sxdp_shared_umem_fd);
if (IS_ERR(sock)) {
err = PTR_ERR(sock);
goto out_unlock;
}
umem_xs = xdp_sk(sock->sk);
if (!xsk_is_bound(umem_xs)) {
err = -EBADF;
sockfd_put(sock);
goto out_unlock;
}
if (umem_xs->queue_id != qid || umem_xs->dev != dev) {
/* Share the umem with another socket on another qid
* and/or device.
*/
xs->pool = xp_create_and_assign_umem(xs,
umem_xs->umem);
if (!xs->pool) {
err = -ENOMEM;
sockfd_put(sock);
goto out_unlock;
}
err = xp_assign_dev_shared(xs->pool, umem_xs, dev,
qid);
if (err) {
xp_destroy(xs->pool);
xs->pool = NULL;
sockfd_put(sock);
goto out_unlock;
}
} else {
/* Share the buffer pool with the other socket. */
if (xs->fq_tmp || xs->cq_tmp) {
/* Do not allow setting your own fq or cq. */
err = -EINVAL;
sockfd_put(sock);
goto out_unlock;
}
xp_get_pool(umem_xs->pool);
xs->pool = umem_xs->pool;
/* If underlying shared umem was created without Tx
* ring, allocate Tx descs array that Tx batching API
* utilizes
*/
if (xs->tx && !xs->pool->tx_descs) {
err = xp_alloc_tx_descs(xs->pool, xs);
if (err) {
xp_put_pool(xs->pool);
xs->pool = NULL;
sockfd_put(sock);
goto out_unlock;
}
}
}
xdp_get_umem(umem_xs->umem);
WRITE_ONCE(xs->umem, umem_xs->umem);
sockfd_put(sock);
} else if (!xs->umem || !xsk_validate_queues(xs)) {
err = -EINVAL;
goto out_unlock;
} else {
/* This xsk has its own umem. */
xs->pool = xp_create_and_assign_umem(xs, xs->umem);
if (!xs->pool) {
err = -ENOMEM;
goto out_unlock;
}
err = xp_assign_dev(xs->pool, dev, qid, flags);
if (err) {
xp_destroy(xs->pool);
xs->pool = NULL;
goto out_unlock;
}
}
/* FQ and CQ are now owned by the buffer pool and cleaned up with it. */
xs->fq_tmp = NULL;
xs->cq_tmp = NULL;
xs->dev = dev;
xs->zc = xs->umem->zc;
xs->sg = !!(xs->umem->flags & XDP_UMEM_SG_FLAG);
xs->queue_id = qid;
xp_add_xsk(xs->pool, xs);
out_unlock:
if (err) {
dev_put(dev);
} else {
/* Matches smp_rmb() in bind() for shared umem
* sockets, and xsk_is_bound().
*/
smp_wmb();
WRITE_ONCE(xs->state, XSK_BOUND);
}
out_release:
mutex_unlock(&xs->mutex);
rtnl_unlock();
return err;
}
struct xdp_umem_reg_v1 {
__u64 addr; /* Start of packet data area */
__u64 len; /* Length of packet data area */
__u32 chunk_size;
__u32 headroom;
};
static int xsk_setsockopt(struct socket *sock, int level, int optname,
sockptr_t optval, unsigned int optlen)
{
struct sock *sk = sock->sk;
struct xdp_sock *xs = xdp_sk(sk);
int err;
if (level != SOL_XDP)
return -ENOPROTOOPT;
switch (optname) {
case XDP_RX_RING:
case XDP_TX_RING:
{
struct xsk_queue **q;
int entries;
if (optlen < sizeof(entries))
return -EINVAL;
if (copy_from_sockptr(&entries, optval, sizeof(entries)))
return -EFAULT;
mutex_lock(&xs->mutex);
if (xs->state != XSK_READY) {
mutex_unlock(&xs->mutex);
return -EBUSY;
}
q = (optname == XDP_TX_RING) ? &xs->tx : &xs->rx;
err = xsk_init_queue(entries, q, false);
if (!err && optname == XDP_TX_RING)
/* Tx needs to be explicitly woken up the first time */
xs->tx->ring->flags |= XDP_RING_NEED_WAKEUP;
mutex_unlock(&xs->mutex);
return err;
}
case XDP_UMEM_REG:
{
size_t mr_size = sizeof(struct xdp_umem_reg);
struct xdp_umem_reg mr = {};
struct xdp_umem *umem;
if (optlen < sizeof(struct xdp_umem_reg_v1))
return -EINVAL;
else if (optlen < sizeof(mr))
mr_size = sizeof(struct xdp_umem_reg_v1);
BUILD_BUG_ON(sizeof(struct xdp_umem_reg_v1) >= sizeof(struct xdp_umem_reg));
/* Make sure the last field of the struct doesn't have
* uninitialized padding. All padding has to be explicit
* and has to be set to zero by the userspace to make
* struct xdp_umem_reg extensible in the future.
*/
BUILD_BUG_ON(offsetof(struct xdp_umem_reg, tx_metadata_len) +
sizeof_field(struct xdp_umem_reg, tx_metadata_len) !=
sizeof(struct xdp_umem_reg));
if (copy_from_sockptr(&mr, optval, mr_size))
return -EFAULT;
mutex_lock(&xs->mutex);
if (xs->state != XSK_READY || xs->umem) {
mutex_unlock(&xs->mutex);
return -EBUSY;
}
umem = xdp_umem_create(&mr);
if (IS_ERR(umem)) {
mutex_unlock(&xs->mutex);
return PTR_ERR(umem);
}
/* Make sure umem is ready before it can be seen by others */
smp_wmb();
WRITE_ONCE(xs->umem, umem);
mutex_unlock(&xs->mutex);
return 0;
}
case XDP_UMEM_FILL_RING:
case XDP_UMEM_COMPLETION_RING:
{
struct xsk_queue **q;
int entries;
if (optlen < sizeof(entries))
return -EINVAL;
if (copy_from_sockptr(&entries, optval, sizeof(entries)))
return -EFAULT;
mutex_lock(&xs->mutex);
if (xs->state != XSK_READY) {
mutex_unlock(&xs->mutex);
return -EBUSY;
}
q = (optname == XDP_UMEM_FILL_RING) ? &xs->fq_tmp :
&xs->cq_tmp;
err = xsk_init_queue(entries, q, true);
mutex_unlock(&xs->mutex);
return err;
}
default:
break;
}
return -ENOPROTOOPT;
}
static void xsk_enter_rxtx_offsets(struct xdp_ring_offset_v1 *ring)
{
ring->producer = offsetof(struct xdp_rxtx_ring, ptrs.producer);
ring->consumer = offsetof(struct xdp_rxtx_ring, ptrs.consumer);
ring->desc = offsetof(struct xdp_rxtx_ring, desc);
}
static void xsk_enter_umem_offsets(struct xdp_ring_offset_v1 *ring)
{
ring->producer = offsetof(struct xdp_umem_ring, ptrs.producer);
ring->consumer = offsetof(struct xdp_umem_ring, ptrs.consumer);
ring->desc = offsetof(struct xdp_umem_ring, desc);
}
struct xdp_statistics_v1 {
__u64 rx_dropped;
__u64 rx_invalid_descs;
__u64 tx_invalid_descs;
};
static int xsk_getsockopt(struct socket *sock, int level, int optname,
char __user *optval, int __user *optlen)
{
struct sock *sk = sock->sk;
struct xdp_sock *xs = xdp_sk(sk);
int len;
if (level != SOL_XDP)
return -ENOPROTOOPT;
if (get_user(len, optlen))
return -EFAULT;
if (len < 0)
return -EINVAL;
switch (optname) {
case XDP_STATISTICS:
{
struct xdp_statistics stats = {};
bool extra_stats = true;
size_t stats_size;
if (len < sizeof(struct xdp_statistics_v1)) {
return -EINVAL;
} else if (len < sizeof(stats)) {
extra_stats = false;
stats_size = sizeof(struct xdp_statistics_v1);
} else {
stats_size = sizeof(stats);
}
mutex_lock(&xs->mutex);
stats.rx_dropped = xs->rx_dropped;
if (extra_stats) {
stats.rx_ring_full = xs->rx_queue_full;
stats.rx_fill_ring_empty_descs =
xs->pool ? xskq_nb_queue_empty_descs(xs->pool->fq) : 0;
stats.tx_ring_empty_descs = xskq_nb_queue_empty_descs(xs->tx);
} else {
stats.rx_dropped += xs->rx_queue_full;
}
stats.rx_invalid_descs = xskq_nb_invalid_descs(xs->rx);
stats.tx_invalid_descs = xskq_nb_invalid_descs(xs->tx);
mutex_unlock(&xs->mutex);
if (copy_to_user(optval, &stats, stats_size))
return -EFAULT;
if (put_user(stats_size, optlen))
return -EFAULT;
return 0;
}
case XDP_MMAP_OFFSETS:
{
struct xdp_mmap_offsets off;
struct xdp_mmap_offsets_v1 off_v1;
bool flags_supported = true;
void *to_copy;
if (len < sizeof(off_v1))
return -EINVAL;
else if (len < sizeof(off))
flags_supported = false;
if (flags_supported) {
/* xdp_ring_offset is identical to xdp_ring_offset_v1
* except for the flags field added to the end.
*/
xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *)
&off.rx);
xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *)
&off.tx);
xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *)
&off.fr);
xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *)
&off.cr);
off.rx.flags = offsetof(struct xdp_rxtx_ring,
ptrs.flags);
off.tx.flags = offsetof(struct xdp_rxtx_ring,
ptrs.flags);
off.fr.flags = offsetof(struct xdp_umem_ring,
ptrs.flags);
off.cr.flags = offsetof(struct xdp_umem_ring,
ptrs.flags);
len = sizeof(off);
to_copy = &off;
} else {
xsk_enter_rxtx_offsets(&off_v1.rx);
xsk_enter_rxtx_offsets(&off_v1.tx);
xsk_enter_umem_offsets(&off_v1.fr);
xsk_enter_umem_offsets(&off_v1.cr);
len = sizeof(off_v1);
to_copy = &off_v1;
}
if (copy_to_user(optval, to_copy, len))
return -EFAULT;
if (put_user(len, optlen))
return -EFAULT;
return 0;
}
case XDP_OPTIONS:
{
struct xdp_options opts = {};
if (len < sizeof(opts))
return -EINVAL;
mutex_lock(&xs->mutex);
if (xs->zc)
opts.flags |= XDP_OPTIONS_ZEROCOPY;
mutex_unlock(&xs->mutex);
len = sizeof(opts);
if (copy_to_user(optval, &opts, len))
return -EFAULT;
if (put_user(len, optlen))
return -EFAULT;
return 0;
}
default:
break;
}
return -EOPNOTSUPP;
}
static int xsk_mmap(struct file *file, struct socket *sock,
struct vm_area_struct *vma)
{
loff_t offset = (loff_t)vma->vm_pgoff << PAGE_SHIFT;
unsigned long size = vma->vm_end - vma->vm_start;
struct xdp_sock *xs = xdp_sk(sock->sk);
int state = READ_ONCE(xs->state);
struct xsk_queue *q = NULL;
if (state != XSK_READY && state != XSK_BOUND)
return -EBUSY;
if (offset == XDP_PGOFF_RX_RING) {
q = READ_ONCE(xs->rx);
} else if (offset == XDP_PGOFF_TX_RING) {
q = READ_ONCE(xs->tx);
} else {
/* Matches the smp_wmb() in XDP_UMEM_REG */
smp_rmb();
if (offset == XDP_UMEM_PGOFF_FILL_RING)
q = state == XSK_READY ? READ_ONCE(xs->fq_tmp) :
READ_ONCE(xs->pool->fq);
else if (offset == XDP_UMEM_PGOFF_COMPLETION_RING)
q = state == XSK_READY ? READ_ONCE(xs->cq_tmp) :
READ_ONCE(xs->pool->cq);
}
if (!q)
return -EINVAL;
/* Matches the smp_wmb() in xsk_init_queue */
smp_rmb();
if (size > q->ring_vmalloc_size)
return -EINVAL;
return remap_vmalloc_range(vma, q->ring, 0);
}
static int xsk_notifier(struct notifier_block *this,
unsigned long msg, void *ptr)
{
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
struct net *net = dev_net(dev);
struct sock *sk;
switch (msg) {
case NETDEV_UNREGISTER:
mutex_lock(&net->xdp.lock);
sk_for_each(sk, &net->xdp.list) {
struct xdp_sock *xs = xdp_sk(sk);
mutex_lock(&xs->mutex);
if (xs->dev == dev) {
sk->sk_err = ENETDOWN;
if (!sock_flag(sk, SOCK_DEAD))
sk_error_report(sk);
xsk_unbind_dev(xs);
/* Clear device references. */
xp_clear_dev(xs->pool);
}
mutex_unlock(&xs->mutex);
}
mutex_unlock(&net->xdp.lock);
break;
}
return NOTIFY_DONE;
}
static struct proto xsk_proto = {
.name = "XDP",
.owner = THIS_MODULE,
.obj_size = sizeof(struct xdp_sock),
};
static const struct proto_ops xsk_proto_ops = {
.family = PF_XDP,
.owner = THIS_MODULE,
.release = xsk_release,
.bind = xsk_bind,
.connect = sock_no_connect,
.socketpair = sock_no_socketpair,
.accept = sock_no_accept,
.getname = sock_no_getname,
.poll = xsk_poll,
.ioctl = sock_no_ioctl,
.listen = sock_no_listen,
.shutdown = sock_no_shutdown,
.setsockopt = xsk_setsockopt,
.getsockopt = xsk_getsockopt,
.sendmsg = xsk_sendmsg,
.recvmsg = xsk_recvmsg,
.mmap = xsk_mmap,
};
static void xsk_destruct(struct sock *sk)
{
struct xdp_sock *xs = xdp_sk(sk);
if (!sock_flag(sk, SOCK_DEAD))
return;
if (!xp_put_pool(xs->pool))
xdp_put_umem(xs->umem, !xs->pool);
}
static int xsk_create(struct net *net, struct socket *sock, int protocol,
int kern)
{
struct xdp_sock *xs;
struct sock *sk;
if (!ns_capable(net->user_ns, CAP_NET_RAW))
return -EPERM;
if (sock->type != SOCK_RAW)
return -ESOCKTNOSUPPORT;
if (protocol)
return -EPROTONOSUPPORT;
sock->state = SS_UNCONNECTED;
sk = sk_alloc(net, PF_XDP, GFP_KERNEL, &xsk_proto, kern);
if (!sk)
return -ENOBUFS;
sock->ops = &xsk_proto_ops;
sock_init_data(sock, sk);
sk->sk_family = PF_XDP;
sk->sk_destruct = xsk_destruct;
sock_set_flag(sk, SOCK_RCU_FREE);
xs = xdp_sk(sk);
xs->state = XSK_READY;
mutex_init(&xs->mutex);
spin_lock_init(&xs->rx_lock);
INIT_LIST_HEAD(&xs->map_list);
spin_lock_init(&xs->map_list_lock);
mutex_lock(&net->xdp.lock);
sk_add_node_rcu(sk, &net->xdp.list);
mutex_unlock(&net->xdp.lock);
sock_prot_inuse_add(net, &xsk_proto, 1);
return 0;
}
static const struct net_proto_family xsk_family_ops = {
.family = PF_XDP,
.create = xsk_create,
.owner = THIS_MODULE,
};
static struct notifier_block xsk_netdev_notifier = {
.notifier_call = xsk_notifier,
};
static int __net_init xsk_net_init(struct net *net)
{
mutex_init(&net->xdp.lock);
INIT_HLIST_HEAD(&net->xdp.list);
return 0;
}
static void __net_exit xsk_net_exit(struct net *net)
{
WARN_ON_ONCE(!hlist_empty(&net->xdp.list));
}
static struct pernet_operations xsk_net_ops = {
.init = xsk_net_init,
.exit = xsk_net_exit,
};
static int __init xsk_init(void)
{
int err;
err = proto_register(&xsk_proto, 0 /* no slab */);
if (err)
goto out;
err = sock_register(&xsk_family_ops);
if (err)
goto out_proto;
err = register_pernet_subsys(&xsk_net_ops);
if (err)
goto out_sk;
err = register_netdevice_notifier(&xsk_netdev_notifier);
if (err)
goto out_pernet;
return 0;
out_pernet:
unregister_pernet_subsys(&xsk_net_ops);
out_sk:
sock_unregister(PF_XDP);
out_proto:
proto_unregister(&xsk_proto);
out:
return err;
}
fs_initcall(xsk_init);
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