summaryrefslogtreecommitdiffstats
path: root/net/xdp/xsk.c
diff options
context:
space:
mode:
Diffstat (limited to 'net/xdp/xsk.c')
-rw-r--r--net/xdp/xsk.c1722
1 files changed, 1722 insertions, 0 deletions
diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
new file mode 100644
index 0000000000..d849dc04a3
--- /dev/null
+++ b/net/xdp/xsk.c
@@ -0,0 +1,1722 @@
+// 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 <bjorn.topel@intel.com>
+ * Magnus Karlsson <magnus.karlsson@intel.com>
+ */
+
+#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
+
+static DEFINE_PER_CPU(struct list_head, xskmap_flush_list);
+
+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, &copy_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)
+{
+ struct list_head *flush_list = this_cpu_ptr(&xskmap_flush_list);
+ int err;
+
+ err = xsk_rcv(xs, xdp);
+ if (err)
+ return err;
+
+ if (!xs->flush_node.prev)
+ list_add(&xs->flush_node, flush_list);
+
+ return 0;
+}
+
+void __xsk_map_flush(void)
+{
+ struct list_head *flush_list = this_cpu_ptr(&xskmap_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)
+{
+ struct xdp_sock *xs;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) {
+ if (!xskq_cons_peek_desc(xs->tx, desc, pool)) {
+ if (xskq_has_descs(xs->tx))
+ xskq_cons_release(xs->tx);
+ continue;
+ }
+
+ /* 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;
+ }
+
+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)
+{
+ 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 net_device *dev = xs->dev;
+ struct sk_buff *skb = xs->skb;
+ 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;
+ }
+ } 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, 0);
+ }
+ }
+
+ skb->dev = dev;
+ skb->priority = xs->sk.sk_priority;
+ skb->mark = READ_ONCE(xs->sk.sk_mark);
+ skb->destructor = xsk_destruct_skb;
+ 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);
+
+ 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 (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, cpu;
+
+ 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;
+
+ for_each_possible_cpu(cpu)
+ INIT_LIST_HEAD(&per_cpu(xskmap_flush_list, cpu));
+ 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);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-03 01:58:43 +0000