1 // SPDX-License-Identifier: GPL-2.0
4 * AF_XDP sockets allows a channel between XDP programs and userspace
6 * Copyright(c) 2018 Intel Corporation.
8 * Author(s): Björn Töpel <bjorn.topel@intel.com>
9 * Magnus Karlsson <magnus.karlsson@intel.com>
12 #define pr_fmt(fmt) "AF_XDP: %s: " fmt, __func__
14 #include <linux/if_xdp.h>
15 #include <linux/init.h>
16 #include <linux/sched/mm.h>
17 #include <linux/sched/signal.h>
18 #include <linux/sched/task.h>
19 #include <linux/socket.h>
20 #include <linux/file.h>
21 #include <linux/uaccess.h>
22 #include <linux/net.h>
23 #include <linux/netdevice.h>
24 #include <linux/rculist.h>
25 #include <net/xdp_sock_drv.h>
26 #include <net/busy_poll.h>
29 #include "xsk_queue.h"
33 #define TX_BATCH_SIZE 32
35 static DEFINE_PER_CPU(struct list_head, xskmap_flush_list);
37 void xsk_set_rx_need_wakeup(struct xsk_buff_pool *pool)
39 if (pool->cached_need_wakeup & XDP_WAKEUP_RX)
42 pool->fq->ring->flags |= XDP_RING_NEED_WAKEUP;
43 pool->cached_need_wakeup |= XDP_WAKEUP_RX;
45 EXPORT_SYMBOL(xsk_set_rx_need_wakeup);
47 void xsk_set_tx_need_wakeup(struct xsk_buff_pool *pool)
51 if (pool->cached_need_wakeup & XDP_WAKEUP_TX)
55 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) {
56 xs->tx->ring->flags |= XDP_RING_NEED_WAKEUP;
60 pool->cached_need_wakeup |= XDP_WAKEUP_TX;
62 EXPORT_SYMBOL(xsk_set_tx_need_wakeup);
64 void xsk_clear_rx_need_wakeup(struct xsk_buff_pool *pool)
66 if (!(pool->cached_need_wakeup & XDP_WAKEUP_RX))
69 pool->fq->ring->flags &= ~XDP_RING_NEED_WAKEUP;
70 pool->cached_need_wakeup &= ~XDP_WAKEUP_RX;
72 EXPORT_SYMBOL(xsk_clear_rx_need_wakeup);
74 void xsk_clear_tx_need_wakeup(struct xsk_buff_pool *pool)
78 if (!(pool->cached_need_wakeup & XDP_WAKEUP_TX))
82 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) {
83 xs->tx->ring->flags &= ~XDP_RING_NEED_WAKEUP;
87 pool->cached_need_wakeup &= ~XDP_WAKEUP_TX;
89 EXPORT_SYMBOL(xsk_clear_tx_need_wakeup);
91 bool xsk_uses_need_wakeup(struct xsk_buff_pool *pool)
93 return pool->uses_need_wakeup;
95 EXPORT_SYMBOL(xsk_uses_need_wakeup);
97 struct xsk_buff_pool *xsk_get_pool_from_qid(struct net_device *dev,
100 if (queue_id < dev->real_num_rx_queues)
101 return dev->_rx[queue_id].pool;
102 if (queue_id < dev->real_num_tx_queues)
103 return dev->_tx[queue_id].pool;
107 EXPORT_SYMBOL(xsk_get_pool_from_qid);
109 void xsk_clear_pool_at_qid(struct net_device *dev, u16 queue_id)
111 if (queue_id < dev->num_rx_queues)
112 dev->_rx[queue_id].pool = NULL;
113 if (queue_id < dev->num_tx_queues)
114 dev->_tx[queue_id].pool = NULL;
117 /* The buffer pool is stored both in the _rx struct and the _tx struct as we do
118 * not know if the device has more tx queues than rx, or the opposite.
119 * This might also change during run time.
121 int xsk_reg_pool_at_qid(struct net_device *dev, struct xsk_buff_pool *pool,
124 if (queue_id >= max_t(unsigned int,
125 dev->real_num_rx_queues,
126 dev->real_num_tx_queues))
129 if (queue_id < dev->real_num_rx_queues)
130 dev->_rx[queue_id].pool = pool;
131 if (queue_id < dev->real_num_tx_queues)
132 dev->_tx[queue_id].pool = pool;
137 void xp_release(struct xdp_buff_xsk *xskb)
139 xskb->pool->free_heads[xskb->pool->free_heads_cnt++] = xskb;
142 static u64 xp_get_handle(struct xdp_buff_xsk *xskb)
144 u64 offset = xskb->xdp.data - xskb->xdp.data_hard_start;
146 offset += xskb->pool->headroom;
147 if (!xskb->pool->unaligned)
148 return xskb->orig_addr + offset;
149 return xskb->orig_addr + (offset << XSK_UNALIGNED_BUF_OFFSET_SHIFT);
152 static int __xsk_rcv_zc(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len)
154 struct xdp_buff_xsk *xskb = container_of(xdp, struct xdp_buff_xsk, xdp);
158 addr = xp_get_handle(xskb);
159 err = xskq_prod_reserve_desc(xs->rx, addr, len);
169 static void xsk_copy_xdp(struct xdp_buff *to, struct xdp_buff *from, u32 len)
171 void *from_buf, *to_buf;
174 if (unlikely(xdp_data_meta_unsupported(from))) {
175 from_buf = from->data;
179 from_buf = from->data_meta;
180 metalen = from->data - from->data_meta;
181 to_buf = to->data - metalen;
184 memcpy(to_buf, from_buf, len + metalen);
187 static int __xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
189 struct xdp_buff *xsk_xdp;
193 len = xdp->data_end - xdp->data;
194 if (len > xsk_pool_get_rx_frame_size(xs->pool)) {
199 xsk_xdp = xsk_buff_alloc(xs->pool);
205 xsk_copy_xdp(xsk_xdp, xdp, len);
206 err = __xsk_rcv_zc(xs, xsk_xdp, len);
208 xsk_buff_free(xsk_xdp);
214 static bool xsk_tx_writeable(struct xdp_sock *xs)
216 if (xskq_cons_present_entries(xs->tx) > xs->tx->nentries / 2)
222 static bool xsk_is_bound(struct xdp_sock *xs)
224 if (READ_ONCE(xs->state) == XSK_BOUND) {
225 /* Matches smp_wmb() in bind(). */
232 static int xsk_rcv_check(struct xdp_sock *xs, struct xdp_buff *xdp)
234 if (!xsk_is_bound(xs))
237 if (xs->dev != xdp->rxq->dev || xs->queue_id != xdp->rxq->queue_index)
240 sk_mark_napi_id_once_xdp(&xs->sk, xdp);
244 static void xsk_flush(struct xdp_sock *xs)
246 xskq_prod_submit(xs->rx);
247 __xskq_cons_release(xs->pool->fq);
248 sock_def_readable(&xs->sk);
251 int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
255 spin_lock_bh(&xs->rx_lock);
256 err = xsk_rcv_check(xs, xdp);
258 err = __xsk_rcv(xs, xdp);
261 spin_unlock_bh(&xs->rx_lock);
265 static int xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
270 err = xsk_rcv_check(xs, xdp);
274 if (xdp->rxq->mem.type == MEM_TYPE_XSK_BUFF_POOL) {
275 len = xdp->data_end - xdp->data;
276 return __xsk_rcv_zc(xs, xdp, len);
279 err = __xsk_rcv(xs, xdp);
281 xdp_return_buff(xdp);
285 int __xsk_map_redirect(struct xdp_sock *xs, struct xdp_buff *xdp)
287 struct list_head *flush_list = this_cpu_ptr(&xskmap_flush_list);
290 err = xsk_rcv(xs, xdp);
294 if (!xs->flush_node.prev)
295 list_add(&xs->flush_node, flush_list);
300 void __xsk_map_flush(void)
302 struct list_head *flush_list = this_cpu_ptr(&xskmap_flush_list);
303 struct xdp_sock *xs, *tmp;
305 list_for_each_entry_safe(xs, tmp, flush_list, flush_node) {
307 __list_del_clearprev(&xs->flush_node);
311 void xsk_tx_completed(struct xsk_buff_pool *pool, u32 nb_entries)
313 xskq_prod_submit_n(pool->cq, nb_entries);
315 EXPORT_SYMBOL(xsk_tx_completed);
317 void xsk_tx_release(struct xsk_buff_pool *pool)
322 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) {
323 __xskq_cons_release(xs->tx);
324 if (xsk_tx_writeable(xs))
325 xs->sk.sk_write_space(&xs->sk);
329 EXPORT_SYMBOL(xsk_tx_release);
331 bool xsk_tx_peek_desc(struct xsk_buff_pool *pool, struct xdp_desc *desc)
336 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) {
337 if (!xskq_cons_peek_desc(xs->tx, desc, pool)) {
338 xs->tx->queue_empty_descs++;
342 /* This is the backpressure mechanism for the Tx path.
343 * Reserve space in the completion queue and only proceed
344 * if there is space in it. This avoids having to implement
345 * any buffering in the Tx path.
347 if (xskq_prod_reserve_addr(pool->cq, desc->addr))
350 xskq_cons_release(xs->tx);
359 EXPORT_SYMBOL(xsk_tx_peek_desc);
361 static u32 xsk_tx_peek_release_fallback(struct xsk_buff_pool *pool, u32 max_entries)
363 struct xdp_desc *descs = pool->tx_descs;
366 while (nb_pkts < max_entries && xsk_tx_peek_desc(pool, &descs[nb_pkts]))
369 xsk_tx_release(pool);
373 u32 xsk_tx_peek_release_desc_batch(struct xsk_buff_pool *pool, u32 nb_pkts)
378 if (!list_is_singular(&pool->xsk_tx_list)) {
379 /* Fallback to the non-batched version */
381 return xsk_tx_peek_release_fallback(pool, nb_pkts);
384 xs = list_first_or_null_rcu(&pool->xsk_tx_list, struct xdp_sock, tx_list);
390 nb_pkts = xskq_cons_nb_entries(xs->tx, nb_pkts);
392 /* This is the backpressure mechanism for the Tx path. Try to
393 * reserve space in the completion queue for all packets, but
394 * if there are fewer slots available, just process that many
395 * packets. This avoids having to implement any buffering in
398 nb_pkts = xskq_prod_nb_free(pool->cq, nb_pkts);
402 nb_pkts = xskq_cons_read_desc_batch(xs->tx, pool, nb_pkts);
404 xs->tx->queue_empty_descs++;
408 __xskq_cons_release(xs->tx);
409 xskq_prod_write_addr_batch(pool->cq, pool->tx_descs, nb_pkts);
410 xs->sk.sk_write_space(&xs->sk);
416 EXPORT_SYMBOL(xsk_tx_peek_release_desc_batch);
418 static int xsk_wakeup(struct xdp_sock *xs, u8 flags)
420 struct net_device *dev = xs->dev;
422 return dev->netdev_ops->ndo_xsk_wakeup(dev, xs->queue_id, flags);
425 static void xsk_destruct_skb(struct sk_buff *skb)
427 u64 addr = (u64)(long)skb_shinfo(skb)->destructor_arg;
428 struct xdp_sock *xs = xdp_sk(skb->sk);
431 spin_lock_irqsave(&xs->pool->cq_lock, flags);
432 xskq_prod_submit_addr(xs->pool->cq, addr);
433 spin_unlock_irqrestore(&xs->pool->cq_lock, flags);
438 static struct sk_buff *xsk_build_skb_zerocopy(struct xdp_sock *xs,
439 struct xdp_desc *desc)
441 struct xsk_buff_pool *pool = xs->pool;
442 u32 hr, len, ts, offset, copy, copied;
449 hr = max(NET_SKB_PAD, L1_CACHE_ALIGN(xs->dev->needed_headroom));
451 skb = sock_alloc_send_skb(&xs->sk, hr, 1, &err);
455 skb_reserve(skb, hr);
459 ts = pool->unaligned ? len : pool->chunk_size;
461 buffer = xsk_buff_raw_get_data(pool, addr);
462 offset = offset_in_page(buffer);
463 addr = buffer - pool->addrs;
465 for (copied = 0, i = 0; copied < len; i++) {
466 page = pool->umem->pgs[addr >> PAGE_SHIFT];
469 copy = min_t(u32, PAGE_SIZE - offset, len - copied);
470 skb_fill_page_desc(skb, i, page, offset, copy);
478 skb->data_len += len;
481 refcount_add(ts, &xs->sk.sk_wmem_alloc);
486 static struct sk_buff *xsk_build_skb(struct xdp_sock *xs,
487 struct xdp_desc *desc)
489 struct net_device *dev = xs->dev;
492 if (dev->priv_flags & IFF_TX_SKB_NO_LINEAR) {
493 skb = xsk_build_skb_zerocopy(xs, desc);
501 hr = max(NET_SKB_PAD, L1_CACHE_ALIGN(dev->needed_headroom));
502 tr = dev->needed_tailroom;
505 skb = sock_alloc_send_skb(&xs->sk, hr + len + tr, 1, &err);
509 skb_reserve(skb, hr);
512 buffer = xsk_buff_raw_get_data(xs->pool, desc->addr);
513 err = skb_store_bits(skb, 0, buffer, len);
521 skb->priority = xs->sk.sk_priority;
522 skb->mark = xs->sk.sk_mark;
523 skb_shinfo(skb)->destructor_arg = (void *)(long)desc->addr;
524 skb->destructor = xsk_destruct_skb;
529 static int xsk_generic_xmit(struct sock *sk)
531 struct xdp_sock *xs = xdp_sk(sk);
532 u32 max_batch = TX_BATCH_SIZE;
533 bool sent_frame = false;
534 struct xdp_desc desc;
539 mutex_lock(&xs->mutex);
541 /* Since we dropped the RCU read lock, the socket state might have changed. */
542 if (unlikely(!xsk_is_bound(xs))) {
547 if (xs->queue_id >= xs->dev->real_num_tx_queues)
550 while (xskq_cons_peek_desc(xs->tx, &desc, xs->pool)) {
551 if (max_batch-- == 0) {
556 /* This is the backpressure mechanism for the Tx path.
557 * Reserve space in the completion queue and only proceed
558 * if there is space in it. This avoids having to implement
559 * any buffering in the Tx path.
561 spin_lock_irqsave(&xs->pool->cq_lock, flags);
562 if (xskq_prod_reserve(xs->pool->cq)) {
563 spin_unlock_irqrestore(&xs->pool->cq_lock, flags);
566 spin_unlock_irqrestore(&xs->pool->cq_lock, flags);
568 skb = xsk_build_skb(xs, &desc);
571 spin_lock_irqsave(&xs->pool->cq_lock, flags);
572 xskq_prod_cancel(xs->pool->cq);
573 spin_unlock_irqrestore(&xs->pool->cq_lock, flags);
577 err = __dev_direct_xmit(skb, xs->queue_id);
578 if (err == NETDEV_TX_BUSY) {
579 /* Tell user-space to retry the send */
580 skb->destructor = sock_wfree;
581 spin_lock_irqsave(&xs->pool->cq_lock, flags);
582 xskq_prod_cancel(xs->pool->cq);
583 spin_unlock_irqrestore(&xs->pool->cq_lock, flags);
584 /* Free skb without triggering the perf drop trace */
590 xskq_cons_release(xs->tx);
591 /* Ignore NET_XMIT_CN as packet might have been sent */
592 if (err == NET_XMIT_DROP) {
593 /* SKB completed but not sent */
601 xs->tx->queue_empty_descs++;
605 if (xsk_tx_writeable(xs))
606 sk->sk_write_space(sk);
608 mutex_unlock(&xs->mutex);
612 static int xsk_xmit(struct sock *sk)
614 struct xdp_sock *xs = xdp_sk(sk);
617 if (unlikely(!(xs->dev->flags & IFF_UP)))
619 if (unlikely(!xs->tx))
623 return xsk_wakeup(xs, XDP_WAKEUP_TX);
625 /* Drop the RCU lock since the SKB path might sleep. */
627 ret = xsk_generic_xmit(sk);
628 /* Reaquire RCU lock before going into common code. */
634 static bool xsk_no_wakeup(struct sock *sk)
636 #ifdef CONFIG_NET_RX_BUSY_POLL
637 /* Prefer busy-polling, skip the wakeup. */
638 return READ_ONCE(sk->sk_prefer_busy_poll) && READ_ONCE(sk->sk_ll_usec) &&
639 READ_ONCE(sk->sk_napi_id) >= MIN_NAPI_ID;
645 static int __xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len)
647 bool need_wait = !(m->msg_flags & MSG_DONTWAIT);
648 struct sock *sk = sock->sk;
649 struct xdp_sock *xs = xdp_sk(sk);
650 struct xsk_buff_pool *pool;
652 if (unlikely(!xsk_is_bound(xs)))
654 if (unlikely(need_wait))
657 if (sk_can_busy_loop(sk))
658 sk_busy_loop(sk, 1); /* only support non-blocking sockets */
660 if (xs->zc && xsk_no_wakeup(sk))
664 if (pool->cached_need_wakeup & XDP_WAKEUP_TX)
669 static int xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len)
674 ret = __xsk_sendmsg(sock, m, total_len);
680 static int __xsk_recvmsg(struct socket *sock, struct msghdr *m, size_t len, int flags)
682 bool need_wait = !(flags & MSG_DONTWAIT);
683 struct sock *sk = sock->sk;
684 struct xdp_sock *xs = xdp_sk(sk);
686 if (unlikely(!xsk_is_bound(xs)))
688 if (unlikely(!(xs->dev->flags & IFF_UP)))
690 if (unlikely(!xs->rx))
692 if (unlikely(need_wait))
695 if (sk_can_busy_loop(sk))
696 sk_busy_loop(sk, 1); /* only support non-blocking sockets */
698 if (xsk_no_wakeup(sk))
701 if (xs->pool->cached_need_wakeup & XDP_WAKEUP_RX && xs->zc)
702 return xsk_wakeup(xs, XDP_WAKEUP_RX);
706 static int xsk_recvmsg(struct socket *sock, struct msghdr *m, size_t len, int flags)
711 ret = __xsk_recvmsg(sock, m, len, flags);
717 static __poll_t xsk_poll(struct file *file, struct socket *sock,
718 struct poll_table_struct *wait)
721 struct sock *sk = sock->sk;
722 struct xdp_sock *xs = xdp_sk(sk);
723 struct xsk_buff_pool *pool;
725 sock_poll_wait(file, sock, wait);
728 if (unlikely(!xsk_is_bound(xs))) {
735 if (pool->cached_need_wakeup) {
737 xsk_wakeup(xs, pool->cached_need_wakeup);
739 /* Poll needs to drive Tx also in copy mode */
743 if (xs->rx && !xskq_prod_is_empty(xs->rx))
744 mask |= EPOLLIN | EPOLLRDNORM;
745 if (xs->tx && xsk_tx_writeable(xs))
746 mask |= EPOLLOUT | EPOLLWRNORM;
752 static int xsk_init_queue(u32 entries, struct xsk_queue **queue,
757 if (entries == 0 || *queue || !is_power_of_2(entries))
760 q = xskq_create(entries, umem_queue);
764 /* Make sure queue is ready before it can be seen by others */
766 WRITE_ONCE(*queue, q);
770 static void xsk_unbind_dev(struct xdp_sock *xs)
772 struct net_device *dev = xs->dev;
774 if (xs->state != XSK_BOUND)
776 WRITE_ONCE(xs->state, XSK_UNBOUND);
778 /* Wait for driver to stop using the xdp socket. */
779 xp_del_xsk(xs->pool, xs);
784 static struct xsk_map *xsk_get_map_list_entry(struct xdp_sock *xs,
785 struct xdp_sock __rcu ***map_entry)
787 struct xsk_map *map = NULL;
788 struct xsk_map_node *node;
792 spin_lock_bh(&xs->map_list_lock);
793 node = list_first_entry_or_null(&xs->map_list, struct xsk_map_node,
796 bpf_map_inc(&node->map->map);
798 *map_entry = node->map_entry;
800 spin_unlock_bh(&xs->map_list_lock);
804 static void xsk_delete_from_maps(struct xdp_sock *xs)
806 /* This function removes the current XDP socket from all the
807 * maps it resides in. We need to take extra care here, due to
808 * the two locks involved. Each map has a lock synchronizing
809 * updates to the entries, and each socket has a lock that
810 * synchronizes access to the list of maps (map_list). For
811 * deadlock avoidance the locks need to be taken in the order
812 * "map lock"->"socket map list lock". We start off by
813 * accessing the socket map list, and take a reference to the
814 * map to guarantee existence between the
815 * xsk_get_map_list_entry() and xsk_map_try_sock_delete()
816 * calls. Then we ask the map to remove the socket, which
817 * tries to remove the socket from the map. Note that there
818 * might be updates to the map between
819 * xsk_get_map_list_entry() and xsk_map_try_sock_delete().
821 struct xdp_sock __rcu **map_entry = NULL;
824 while ((map = xsk_get_map_list_entry(xs, &map_entry))) {
825 xsk_map_try_sock_delete(map, xs, map_entry);
826 bpf_map_put(&map->map);
830 static int xsk_release(struct socket *sock)
832 struct sock *sk = sock->sk;
833 struct xdp_sock *xs = xdp_sk(sk);
841 mutex_lock(&net->xdp.lock);
842 sk_del_node_init_rcu(sk);
843 mutex_unlock(&net->xdp.lock);
846 sock_prot_inuse_add(net, sk->sk_prot, -1);
849 xsk_delete_from_maps(xs);
850 mutex_lock(&xs->mutex);
852 mutex_unlock(&xs->mutex);
854 xskq_destroy(xs->rx);
855 xskq_destroy(xs->tx);
856 xskq_destroy(xs->fq_tmp);
857 xskq_destroy(xs->cq_tmp);
862 sk_refcnt_debug_release(sk);
868 static struct socket *xsk_lookup_xsk_from_fd(int fd)
873 sock = sockfd_lookup(fd, &err);
875 return ERR_PTR(-ENOTSOCK);
877 if (sock->sk->sk_family != PF_XDP) {
879 return ERR_PTR(-ENOPROTOOPT);
885 static bool xsk_validate_queues(struct xdp_sock *xs)
887 return xs->fq_tmp && xs->cq_tmp;
890 static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
892 struct sockaddr_xdp *sxdp = (struct sockaddr_xdp *)addr;
893 struct sock *sk = sock->sk;
894 struct xdp_sock *xs = xdp_sk(sk);
895 struct net_device *dev;
900 if (addr_len < sizeof(struct sockaddr_xdp))
902 if (sxdp->sxdp_family != AF_XDP)
905 flags = sxdp->sxdp_flags;
906 if (flags & ~(XDP_SHARED_UMEM | XDP_COPY | XDP_ZEROCOPY |
907 XDP_USE_NEED_WAKEUP))
910 bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
911 if (bound_dev_if && bound_dev_if != sxdp->sxdp_ifindex)
915 mutex_lock(&xs->mutex);
916 if (xs->state != XSK_READY) {
921 dev = dev_get_by_index(sock_net(sk), sxdp->sxdp_ifindex);
927 if (!xs->rx && !xs->tx) {
932 qid = sxdp->sxdp_queue_id;
934 if (flags & XDP_SHARED_UMEM) {
935 struct xdp_sock *umem_xs;
938 if ((flags & XDP_COPY) || (flags & XDP_ZEROCOPY) ||
939 (flags & XDP_USE_NEED_WAKEUP)) {
940 /* Cannot specify flags for shared sockets. */
946 /* We have already our own. */
951 sock = xsk_lookup_xsk_from_fd(sxdp->sxdp_shared_umem_fd);
957 umem_xs = xdp_sk(sock->sk);
958 if (!xsk_is_bound(umem_xs)) {
964 if (umem_xs->queue_id != qid || umem_xs->dev != dev) {
965 /* Share the umem with another socket on another qid
968 xs->pool = xp_create_and_assign_umem(xs,
976 err = xp_assign_dev_shared(xs->pool, umem_xs, dev,
979 xp_destroy(xs->pool);
985 /* Share the buffer pool with the other socket. */
986 if (xs->fq_tmp || xs->cq_tmp) {
987 /* Do not allow setting your own fq or cq. */
993 xp_get_pool(umem_xs->pool);
994 xs->pool = umem_xs->pool;
996 /* If underlying shared umem was created without Tx
997 * ring, allocate Tx descs array that Tx batching API
1000 if (xs->tx && !xs->pool->tx_descs) {
1001 err = xp_alloc_tx_descs(xs->pool, xs);
1003 xp_put_pool(xs->pool);
1011 xdp_get_umem(umem_xs->umem);
1012 WRITE_ONCE(xs->umem, umem_xs->umem);
1014 } else if (!xs->umem || !xsk_validate_queues(xs)) {
1018 /* This xsk has its own umem. */
1019 xs->pool = xp_create_and_assign_umem(xs, xs->umem);
1025 err = xp_assign_dev(xs->pool, dev, qid, flags);
1027 xp_destroy(xs->pool);
1033 /* FQ and CQ are now owned by the buffer pool and cleaned up with it. */
1038 xs->zc = xs->umem->zc;
1040 xp_add_xsk(xs->pool, xs);
1046 /* Matches smp_rmb() in bind() for shared umem
1047 * sockets, and xsk_is_bound().
1050 WRITE_ONCE(xs->state, XSK_BOUND);
1053 mutex_unlock(&xs->mutex);
1058 struct xdp_umem_reg_v1 {
1059 __u64 addr; /* Start of packet data area */
1060 __u64 len; /* Length of packet data area */
1065 static int xsk_setsockopt(struct socket *sock, int level, int optname,
1066 sockptr_t optval, unsigned int optlen)
1068 struct sock *sk = sock->sk;
1069 struct xdp_sock *xs = xdp_sk(sk);
1072 if (level != SOL_XDP)
1073 return -ENOPROTOOPT;
1079 struct xsk_queue **q;
1082 if (optlen < sizeof(entries))
1084 if (copy_from_sockptr(&entries, optval, sizeof(entries)))
1087 mutex_lock(&xs->mutex);
1088 if (xs->state != XSK_READY) {
1089 mutex_unlock(&xs->mutex);
1092 q = (optname == XDP_TX_RING) ? &xs->tx : &xs->rx;
1093 err = xsk_init_queue(entries, q, false);
1094 if (!err && optname == XDP_TX_RING)
1095 /* Tx needs to be explicitly woken up the first time */
1096 xs->tx->ring->flags |= XDP_RING_NEED_WAKEUP;
1097 mutex_unlock(&xs->mutex);
1102 size_t mr_size = sizeof(struct xdp_umem_reg);
1103 struct xdp_umem_reg mr = {};
1104 struct xdp_umem *umem;
1106 if (optlen < sizeof(struct xdp_umem_reg_v1))
1108 else if (optlen < sizeof(mr))
1109 mr_size = sizeof(struct xdp_umem_reg_v1);
1111 if (copy_from_sockptr(&mr, optval, mr_size))
1114 mutex_lock(&xs->mutex);
1115 if (xs->state != XSK_READY || xs->umem) {
1116 mutex_unlock(&xs->mutex);
1120 umem = xdp_umem_create(&mr);
1122 mutex_unlock(&xs->mutex);
1123 return PTR_ERR(umem);
1126 /* Make sure umem is ready before it can be seen by others */
1128 WRITE_ONCE(xs->umem, umem);
1129 mutex_unlock(&xs->mutex);
1132 case XDP_UMEM_FILL_RING:
1133 case XDP_UMEM_COMPLETION_RING:
1135 struct xsk_queue **q;
1138 if (copy_from_sockptr(&entries, optval, sizeof(entries)))
1141 mutex_lock(&xs->mutex);
1142 if (xs->state != XSK_READY) {
1143 mutex_unlock(&xs->mutex);
1147 q = (optname == XDP_UMEM_FILL_RING) ? &xs->fq_tmp :
1149 err = xsk_init_queue(entries, q, true);
1150 mutex_unlock(&xs->mutex);
1157 return -ENOPROTOOPT;
1160 static void xsk_enter_rxtx_offsets(struct xdp_ring_offset_v1 *ring)
1162 ring->producer = offsetof(struct xdp_rxtx_ring, ptrs.producer);
1163 ring->consumer = offsetof(struct xdp_rxtx_ring, ptrs.consumer);
1164 ring->desc = offsetof(struct xdp_rxtx_ring, desc);
1167 static void xsk_enter_umem_offsets(struct xdp_ring_offset_v1 *ring)
1169 ring->producer = offsetof(struct xdp_umem_ring, ptrs.producer);
1170 ring->consumer = offsetof(struct xdp_umem_ring, ptrs.consumer);
1171 ring->desc = offsetof(struct xdp_umem_ring, desc);
1174 struct xdp_statistics_v1 {
1176 __u64 rx_invalid_descs;
1177 __u64 tx_invalid_descs;
1180 static int xsk_getsockopt(struct socket *sock, int level, int optname,
1181 char __user *optval, int __user *optlen)
1183 struct sock *sk = sock->sk;
1184 struct xdp_sock *xs = xdp_sk(sk);
1187 if (level != SOL_XDP)
1188 return -ENOPROTOOPT;
1190 if (get_user(len, optlen))
1196 case XDP_STATISTICS:
1198 struct xdp_statistics stats = {};
1199 bool extra_stats = true;
1202 if (len < sizeof(struct xdp_statistics_v1)) {
1204 } else if (len < sizeof(stats)) {
1205 extra_stats = false;
1206 stats_size = sizeof(struct xdp_statistics_v1);
1208 stats_size = sizeof(stats);
1211 mutex_lock(&xs->mutex);
1212 stats.rx_dropped = xs->rx_dropped;
1214 stats.rx_ring_full = xs->rx_queue_full;
1215 stats.rx_fill_ring_empty_descs =
1216 xs->pool ? xskq_nb_queue_empty_descs(xs->pool->fq) : 0;
1217 stats.tx_ring_empty_descs = xskq_nb_queue_empty_descs(xs->tx);
1219 stats.rx_dropped += xs->rx_queue_full;
1221 stats.rx_invalid_descs = xskq_nb_invalid_descs(xs->rx);
1222 stats.tx_invalid_descs = xskq_nb_invalid_descs(xs->tx);
1223 mutex_unlock(&xs->mutex);
1225 if (copy_to_user(optval, &stats, stats_size))
1227 if (put_user(stats_size, optlen))
1232 case XDP_MMAP_OFFSETS:
1234 struct xdp_mmap_offsets off;
1235 struct xdp_mmap_offsets_v1 off_v1;
1236 bool flags_supported = true;
1239 if (len < sizeof(off_v1))
1241 else if (len < sizeof(off))
1242 flags_supported = false;
1244 if (flags_supported) {
1245 /* xdp_ring_offset is identical to xdp_ring_offset_v1
1246 * except for the flags field added to the end.
1248 xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *)
1250 xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *)
1252 xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *)
1254 xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *)
1256 off.rx.flags = offsetof(struct xdp_rxtx_ring,
1258 off.tx.flags = offsetof(struct xdp_rxtx_ring,
1260 off.fr.flags = offsetof(struct xdp_umem_ring,
1262 off.cr.flags = offsetof(struct xdp_umem_ring,
1268 xsk_enter_rxtx_offsets(&off_v1.rx);
1269 xsk_enter_rxtx_offsets(&off_v1.tx);
1270 xsk_enter_umem_offsets(&off_v1.fr);
1271 xsk_enter_umem_offsets(&off_v1.cr);
1273 len = sizeof(off_v1);
1277 if (copy_to_user(optval, to_copy, len))
1279 if (put_user(len, optlen))
1286 struct xdp_options opts = {};
1288 if (len < sizeof(opts))
1291 mutex_lock(&xs->mutex);
1293 opts.flags |= XDP_OPTIONS_ZEROCOPY;
1294 mutex_unlock(&xs->mutex);
1297 if (copy_to_user(optval, &opts, len))
1299 if (put_user(len, optlen))
1311 static int xsk_mmap(struct file *file, struct socket *sock,
1312 struct vm_area_struct *vma)
1314 loff_t offset = (loff_t)vma->vm_pgoff << PAGE_SHIFT;
1315 unsigned long size = vma->vm_end - vma->vm_start;
1316 struct xdp_sock *xs = xdp_sk(sock->sk);
1317 struct xsk_queue *q = NULL;
1321 if (READ_ONCE(xs->state) != XSK_READY)
1324 if (offset == XDP_PGOFF_RX_RING) {
1325 q = READ_ONCE(xs->rx);
1326 } else if (offset == XDP_PGOFF_TX_RING) {
1327 q = READ_ONCE(xs->tx);
1329 /* Matches the smp_wmb() in XDP_UMEM_REG */
1331 if (offset == XDP_UMEM_PGOFF_FILL_RING)
1332 q = READ_ONCE(xs->fq_tmp);
1333 else if (offset == XDP_UMEM_PGOFF_COMPLETION_RING)
1334 q = READ_ONCE(xs->cq_tmp);
1340 /* Matches the smp_wmb() in xsk_init_queue */
1342 qpg = virt_to_head_page(q->ring);
1343 if (size > page_size(qpg))
1346 pfn = virt_to_phys(q->ring) >> PAGE_SHIFT;
1347 return remap_pfn_range(vma, vma->vm_start, pfn,
1348 size, vma->vm_page_prot);
1351 static int xsk_notifier(struct notifier_block *this,
1352 unsigned long msg, void *ptr)
1354 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1355 struct net *net = dev_net(dev);
1359 case NETDEV_UNREGISTER:
1360 mutex_lock(&net->xdp.lock);
1361 sk_for_each(sk, &net->xdp.list) {
1362 struct xdp_sock *xs = xdp_sk(sk);
1364 mutex_lock(&xs->mutex);
1365 if (xs->dev == dev) {
1366 sk->sk_err = ENETDOWN;
1367 if (!sock_flag(sk, SOCK_DEAD))
1368 sk_error_report(sk);
1372 /* Clear device references. */
1373 xp_clear_dev(xs->pool);
1375 mutex_unlock(&xs->mutex);
1377 mutex_unlock(&net->xdp.lock);
1383 static struct proto xsk_proto = {
1385 .owner = THIS_MODULE,
1386 .obj_size = sizeof(struct xdp_sock),
1389 static const struct proto_ops xsk_proto_ops = {
1391 .owner = THIS_MODULE,
1392 .release = xsk_release,
1394 .connect = sock_no_connect,
1395 .socketpair = sock_no_socketpair,
1396 .accept = sock_no_accept,
1397 .getname = sock_no_getname,
1399 .ioctl = sock_no_ioctl,
1400 .listen = sock_no_listen,
1401 .shutdown = sock_no_shutdown,
1402 .setsockopt = xsk_setsockopt,
1403 .getsockopt = xsk_getsockopt,
1404 .sendmsg = xsk_sendmsg,
1405 .recvmsg = xsk_recvmsg,
1407 .sendpage = sock_no_sendpage,
1410 static void xsk_destruct(struct sock *sk)
1412 struct xdp_sock *xs = xdp_sk(sk);
1414 if (!sock_flag(sk, SOCK_DEAD))
1417 if (!xp_put_pool(xs->pool))
1418 xdp_put_umem(xs->umem, !xs->pool);
1420 sk_refcnt_debug_dec(sk);
1423 static int xsk_create(struct net *net, struct socket *sock, int protocol,
1426 struct xdp_sock *xs;
1429 if (!ns_capable(net->user_ns, CAP_NET_RAW))
1431 if (sock->type != SOCK_RAW)
1432 return -ESOCKTNOSUPPORT;
1435 return -EPROTONOSUPPORT;
1437 sock->state = SS_UNCONNECTED;
1439 sk = sk_alloc(net, PF_XDP, GFP_KERNEL, &xsk_proto, kern);
1443 sock->ops = &xsk_proto_ops;
1445 sock_init_data(sock, sk);
1447 sk->sk_family = PF_XDP;
1449 sk->sk_destruct = xsk_destruct;
1450 sk_refcnt_debug_inc(sk);
1452 sock_set_flag(sk, SOCK_RCU_FREE);
1455 xs->state = XSK_READY;
1456 mutex_init(&xs->mutex);
1457 spin_lock_init(&xs->rx_lock);
1459 INIT_LIST_HEAD(&xs->map_list);
1460 spin_lock_init(&xs->map_list_lock);
1462 mutex_lock(&net->xdp.lock);
1463 sk_add_node_rcu(sk, &net->xdp.list);
1464 mutex_unlock(&net->xdp.lock);
1467 sock_prot_inuse_add(net, &xsk_proto, 1);
1473 static const struct net_proto_family xsk_family_ops = {
1475 .create = xsk_create,
1476 .owner = THIS_MODULE,
1479 static struct notifier_block xsk_netdev_notifier = {
1480 .notifier_call = xsk_notifier,
1483 static int __net_init xsk_net_init(struct net *net)
1485 mutex_init(&net->xdp.lock);
1486 INIT_HLIST_HEAD(&net->xdp.list);
1490 static void __net_exit xsk_net_exit(struct net *net)
1492 WARN_ON_ONCE(!hlist_empty(&net->xdp.list));
1495 static struct pernet_operations xsk_net_ops = {
1496 .init = xsk_net_init,
1497 .exit = xsk_net_exit,
1500 static int __init xsk_init(void)
1504 err = proto_register(&xsk_proto, 0 /* no slab */);
1508 err = sock_register(&xsk_family_ops);
1512 err = register_pernet_subsys(&xsk_net_ops);
1516 err = register_netdevice_notifier(&xsk_netdev_notifier);
1520 for_each_possible_cpu(cpu)
1521 INIT_LIST_HEAD(&per_cpu(xskmap_flush_list, cpu));
1525 unregister_pernet_subsys(&xsk_net_ops);
1527 sock_unregister(PF_XDP);
1529 proto_unregister(&xsk_proto);
1534 fs_initcall(xsk_init);