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-rw-r--r--net/xdp/xsk.c788
1 files changed, 788 insertions, 0 deletions
diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
new file mode 100644
index 0000000000000..c6ed2454f7ce5
--- /dev/null
+++ b/net/xdp/xsk.c
@@ -0,0 +1,788 @@
+// 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 <net/xdp_sock.h>
+#include <net/xdp.h>
+
+#include "xsk_queue.h"
+#include "xdp_umem.h"
+
+#define TX_BATCH_SIZE 16
+
+static struct xdp_sock *xdp_sk(struct sock *sk)
+{
+ return (struct xdp_sock *)sk;
+}
+
+bool xsk_is_setup_for_bpf_map(struct xdp_sock *xs)
+{
+ return READ_ONCE(xs->rx) && READ_ONCE(xs->umem) &&
+ READ_ONCE(xs->umem->fq);
+}
+
+u64 *xsk_umem_peek_addr(struct xdp_umem *umem, u64 *addr)
+{
+ return xskq_peek_addr(umem->fq, addr);
+}
+EXPORT_SYMBOL(xsk_umem_peek_addr);
+
+void xsk_umem_discard_addr(struct xdp_umem *umem)
+{
+ xskq_discard_addr(umem->fq);
+}
+EXPORT_SYMBOL(xsk_umem_discard_addr);
+
+static int __xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len)
+{
+ void *buffer;
+ u64 addr;
+ int err;
+
+ if (!xskq_peek_addr(xs->umem->fq, &addr) ||
+ len > xs->umem->chunk_size_nohr) {
+ xs->rx_dropped++;
+ return -ENOSPC;
+ }
+
+ addr += xs->umem->headroom;
+
+ buffer = xdp_umem_get_data(xs->umem, addr);
+ memcpy(buffer, xdp->data, len);
+ err = xskq_produce_batch_desc(xs->rx, addr, len);
+ if (!err) {
+ xskq_discard_addr(xs->umem->fq);
+ xdp_return_buff(xdp);
+ return 0;
+ }
+
+ xs->rx_dropped++;
+ return err;
+}
+
+static int __xsk_rcv_zc(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len)
+{
+ int err = xskq_produce_batch_desc(xs->rx, (u64)xdp->handle, len);
+
+ if (err) {
+ xdp_return_buff(xdp);
+ xs->rx_dropped++;
+ }
+
+ return err;
+}
+
+int xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
+{
+ u32 len;
+
+ if (xs->dev != xdp->rxq->dev || xs->queue_id != xdp->rxq->queue_index)
+ return -EINVAL;
+
+ len = xdp->data_end - xdp->data;
+
+ return (xdp->rxq->mem.type == MEM_TYPE_ZERO_COPY) ?
+ __xsk_rcv_zc(xs, xdp, len) : __xsk_rcv(xs, xdp, len);
+}
+
+void xsk_flush(struct xdp_sock *xs)
+{
+ xskq_produce_flush_desc(xs->rx);
+ xs->sk.sk_data_ready(&xs->sk);
+}
+
+int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
+{
+ u32 len = xdp->data_end - xdp->data;
+ void *buffer;
+ u64 addr;
+ int err;
+
+ if (!xskq_peek_addr(xs->umem->fq, &addr) ||
+ len > xs->umem->chunk_size_nohr) {
+ xs->rx_dropped++;
+ return -ENOSPC;
+ }
+
+ addr += xs->umem->headroom;
+
+ buffer = xdp_umem_get_data(xs->umem, addr);
+ memcpy(buffer, xdp->data, len);
+ err = xskq_produce_batch_desc(xs->rx, addr, len);
+ if (!err) {
+ xskq_discard_addr(xs->umem->fq);
+ xsk_flush(xs);
+ return 0;
+ }
+
+ xs->rx_dropped++;
+ return err;
+}
+
+void xsk_umem_complete_tx(struct xdp_umem *umem, u32 nb_entries)
+{
+ xskq_produce_flush_addr_n(umem->cq, nb_entries);
+}
+EXPORT_SYMBOL(xsk_umem_complete_tx);
+
+void xsk_umem_consume_tx_done(struct xdp_umem *umem)
+{
+ struct xdp_sock *xs;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(xs, &umem->xsk_list, list) {
+ xs->sk.sk_write_space(&xs->sk);
+ }
+ rcu_read_unlock();
+}
+EXPORT_SYMBOL(xsk_umem_consume_tx_done);
+
+bool xsk_umem_consume_tx(struct xdp_umem *umem, dma_addr_t *dma, u32 *len)
+{
+ struct xdp_desc desc;
+ struct xdp_sock *xs;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(xs, &umem->xsk_list, list) {
+ if (!xskq_peek_desc(xs->tx, &desc))
+ continue;
+
+ if (xskq_produce_addr_lazy(umem->cq, desc.addr))
+ goto out;
+
+ *dma = xdp_umem_get_dma(umem, desc.addr);
+ *len = desc.len;
+
+ xskq_discard_desc(xs->tx);
+ rcu_read_unlock();
+ return true;
+ }
+
+out:
+ rcu_read_unlock();
+ return false;
+}
+EXPORT_SYMBOL(xsk_umem_consume_tx);
+
+static int xsk_zc_xmit(struct sock *sk)
+{
+ struct xdp_sock *xs = xdp_sk(sk);
+ struct net_device *dev = xs->dev;
+
+ return dev->netdev_ops->ndo_xsk_async_xmit(dev, xs->queue_id);
+}
+
+static void xsk_destruct_skb(struct sk_buff *skb)
+{
+ u64 addr = (u64)(long)skb_shinfo(skb)->destructor_arg;
+ struct xdp_sock *xs = xdp_sk(skb->sk);
+
+ WARN_ON_ONCE(xskq_produce_addr(xs->umem->cq, addr));
+
+ sock_wfree(skb);
+}
+
+static int xsk_generic_xmit(struct sock *sk, struct msghdr *m,
+ size_t total_len)
+{
+ u32 max_batch = TX_BATCH_SIZE;
+ struct xdp_sock *xs = xdp_sk(sk);
+ bool sent_frame = false;
+ struct xdp_desc desc;
+ struct sk_buff *skb;
+ int err = 0;
+
+ if (unlikely(!xs->tx))
+ return -ENOBUFS;
+
+ mutex_lock(&xs->mutex);
+
+ while (xskq_peek_desc(xs->tx, &desc)) {
+ char *buffer;
+ u64 addr;
+ u32 len;
+
+ if (max_batch-- == 0) {
+ err = -EAGAIN;
+ goto out;
+ }
+
+ if (xskq_reserve_addr(xs->umem->cq)) {
+ err = -EAGAIN;
+ goto out;
+ }
+
+ len = desc.len;
+ if (unlikely(len > xs->dev->mtu)) {
+ err = -EMSGSIZE;
+ goto out;
+ }
+
+ if (xs->queue_id >= xs->dev->real_num_tx_queues) {
+ err = -ENXIO;
+ goto out;
+ }
+
+ skb = sock_alloc_send_skb(sk, len, 1, &err);
+ if (unlikely(!skb)) {
+ err = -EAGAIN;
+ goto out;
+ }
+
+ skb_put(skb, len);
+ addr = desc.addr;
+ buffer = xdp_umem_get_data(xs->umem, addr);
+ err = skb_store_bits(skb, 0, buffer, len);
+ if (unlikely(err)) {
+ kfree_skb(skb);
+ goto out;
+ }
+
+ skb->dev = xs->dev;
+ skb->priority = sk->sk_priority;
+ skb->mark = sk->sk_mark;
+ skb_shinfo(skb)->destructor_arg = (void *)(long)addr;
+ skb->destructor = xsk_destruct_skb;
+
+ err = dev_direct_xmit(skb, xs->queue_id);
+ /* Ignore NET_XMIT_CN as packet might have been sent */
+ if (err == NET_XMIT_DROP || err == NETDEV_TX_BUSY) {
+ err = -EAGAIN;
+ /* SKB consumed by dev_direct_xmit() */
+ goto out;
+ }
+
+ sent_frame = true;
+ xskq_discard_desc(xs->tx);
+ }
+
+out:
+ if (sent_frame)
+ sk->sk_write_space(sk);
+
+ mutex_unlock(&xs->mutex);
+ return err;
+}
+
+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);
+
+ if (unlikely(!xs->dev))
+ return -ENXIO;
+ if (unlikely(!(xs->dev->flags & IFF_UP)))
+ return -ENETDOWN;
+ if (need_wait)
+ return -EOPNOTSUPP;
+
+ return (xs->zc) ? xsk_zc_xmit(sk) : xsk_generic_xmit(sk, m, total_len);
+}
+
+static __poll_t xsk_poll_mask(struct socket *sock, __poll_t events)
+{
+ __poll_t mask = datagram_poll_mask(sock, events);
+ struct sock *sk = sock->sk;
+ struct xdp_sock *xs = xdp_sk(sk);
+
+ if (xs->rx && !xskq_empty_desc(xs->rx))
+ mask |= POLLIN | POLLRDNORM;
+ if (xs->tx && !xskq_full_desc(xs->tx))
+ mask |= POLLOUT | POLLWRNORM;
+
+ 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();
+ *queue = q;
+ return 0;
+}
+
+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);
+
+ local_bh_disable();
+ sock_prot_inuse_add(net, sk->sk_prot, -1);
+ local_bh_enable();
+
+ if (xs->dev) {
+ /* Wait for driver to stop using the xdp socket. */
+ synchronize_net();
+ dev_put(xs->dev);
+ xs->dev = NULL;
+ }
+
+ sock_orphan(sk);
+ sock->sk = NULL;
+
+ sk_refcnt_debug_release(sk);
+ 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 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;
+ u32 flags, qid;
+ int err = 0;
+
+ if (addr_len < sizeof(struct sockaddr_xdp))
+ return -EINVAL;
+ if (sxdp->sxdp_family != AF_XDP)
+ return -EINVAL;
+
+ mutex_lock(&xs->mutex);
+ if (xs->dev) {
+ 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 ((xs->rx && qid >= dev->real_num_rx_queues) ||
+ (xs->tx && qid >= dev->real_num_tx_queues)) {
+ err = -EINVAL;
+ goto out_unlock;
+ }
+
+ flags = sxdp->sxdp_flags;
+
+ if (flags & XDP_SHARED_UMEM) {
+ struct xdp_sock *umem_xs;
+ struct socket *sock;
+
+ if ((flags & XDP_COPY) || (flags & XDP_ZEROCOPY)) {
+ /* 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 (!umem_xs->umem) {
+ /* No umem to inherit. */
+ err = -EBADF;
+ sockfd_put(sock);
+ goto out_unlock;
+ } else if (umem_xs->dev != dev || umem_xs->queue_id != qid) {
+ err = -EINVAL;
+ sockfd_put(sock);
+ goto out_unlock;
+ }
+
+ xdp_get_umem(umem_xs->umem);
+ xs->umem = umem_xs->umem;
+ sockfd_put(sock);
+ } else if (!xs->umem || !xdp_umem_validate_queues(xs->umem)) {
+ err = -EINVAL;
+ goto out_unlock;
+ } else {
+ /* This xsk has its own umem. */
+ xskq_set_umem(xs->umem->fq, &xs->umem->props);
+ xskq_set_umem(xs->umem->cq, &xs->umem->props);
+
+ err = xdp_umem_assign_dev(xs->umem, dev, qid, flags);
+ if (err)
+ goto out_unlock;
+ }
+
+ xs->dev = dev;
+ xs->zc = xs->umem->zc;
+ xs->queue_id = qid;
+ xskq_set_umem(xs->rx, &xs->umem->props);
+ xskq_set_umem(xs->tx, &xs->umem->props);
+ xdp_add_sk_umem(xs->umem, xs);
+
+out_unlock:
+ if (err)
+ dev_put(dev);
+out_release:
+ mutex_unlock(&xs->mutex);
+ return err;
+}
+
+static int xsk_setsockopt(struct socket *sock, int level, int optname,
+ char __user *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_user(&entries, optval, sizeof(entries)))
+ return -EFAULT;
+
+ mutex_lock(&xs->mutex);
+ q = (optname == XDP_TX_RING) ? &xs->tx : &xs->rx;
+ err = xsk_init_queue(entries, q, false);
+ mutex_unlock(&xs->mutex);
+ return err;
+ }
+ case XDP_UMEM_REG:
+ {
+ struct xdp_umem_reg mr;
+ struct xdp_umem *umem;
+
+ if (copy_from_user(&mr, optval, sizeof(mr)))
+ return -EFAULT;
+
+ mutex_lock(&xs->mutex);
+ if (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();
+ 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_user(&entries, optval, sizeof(entries)))
+ return -EFAULT;
+
+ mutex_lock(&xs->mutex);
+ if (!xs->umem) {
+ mutex_unlock(&xs->mutex);
+ return -EINVAL;
+ }
+
+ q = (optname == XDP_UMEM_FILL_RING) ? &xs->umem->fq :
+ &xs->umem->cq;
+ err = xsk_init_queue(entries, q, true);
+ mutex_unlock(&xs->mutex);
+ return err;
+ }
+ default:
+ break;
+ }
+
+ return -ENOPROTOOPT;
+}
+
+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;
+
+ if (len < sizeof(stats))
+ return -EINVAL;
+
+ mutex_lock(&xs->mutex);
+ stats.rx_dropped = xs->rx_dropped;
+ 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, sizeof(stats)))
+ return -EFAULT;
+ if (put_user(sizeof(stats), optlen))
+ return -EFAULT;
+
+ return 0;
+ }
+ case XDP_MMAP_OFFSETS:
+ {
+ struct xdp_mmap_offsets off;
+
+ if (len < sizeof(off))
+ return -EINVAL;
+
+ off.rx.producer = offsetof(struct xdp_rxtx_ring, ptrs.producer);
+ off.rx.consumer = offsetof(struct xdp_rxtx_ring, ptrs.consumer);
+ off.rx.desc = offsetof(struct xdp_rxtx_ring, desc);
+ off.tx.producer = offsetof(struct xdp_rxtx_ring, ptrs.producer);
+ off.tx.consumer = offsetof(struct xdp_rxtx_ring, ptrs.consumer);
+ off.tx.desc = offsetof(struct xdp_rxtx_ring, desc);
+
+ off.fr.producer = offsetof(struct xdp_umem_ring, ptrs.producer);
+ off.fr.consumer = offsetof(struct xdp_umem_ring, ptrs.consumer);
+ off.fr.desc = offsetof(struct xdp_umem_ring, desc);
+ off.cr.producer = offsetof(struct xdp_umem_ring, ptrs.producer);
+ off.cr.consumer = offsetof(struct xdp_umem_ring, ptrs.consumer);
+ off.cr.desc = offsetof(struct xdp_umem_ring, desc);
+
+ len = sizeof(off);
+ if (copy_to_user(optval, &off, 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)
+{
+ unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
+ unsigned long size = vma->vm_end - vma->vm_start;
+ struct xdp_sock *xs = xdp_sk(sock->sk);
+ struct xsk_queue *q = NULL;
+ struct xdp_umem *umem;
+ unsigned long pfn;
+ struct page *qpg;
+
+ if (offset == XDP_PGOFF_RX_RING) {
+ q = READ_ONCE(xs->rx);
+ } else if (offset == XDP_PGOFF_TX_RING) {
+ q = READ_ONCE(xs->tx);
+ } else {
+ umem = READ_ONCE(xs->umem);
+ if (!umem)
+ return -EINVAL;
+
+ if (offset == XDP_UMEM_PGOFF_FILL_RING)
+ q = READ_ONCE(umem->fq);
+ else if (offset == XDP_UMEM_PGOFF_COMPLETION_RING)
+ q = READ_ONCE(umem->cq);
+ }
+
+ if (!q)
+ return -EINVAL;
+
+ qpg = virt_to_head_page(q->ring);
+ if (size > (PAGE_SIZE << compound_order(qpg)))
+ return -EINVAL;
+
+ pfn = virt_to_phys(q->ring) >> PAGE_SHIFT;
+ return remap_pfn_range(vma, vma->vm_start, pfn,
+ size, vma->vm_page_prot);
+}
+
+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_mask = xsk_poll_mask,
+ .ioctl = sock_no_ioctl,
+ .listen = sock_no_listen,
+ .shutdown = sock_no_shutdown,
+ .setsockopt = xsk_setsockopt,
+ .getsockopt = xsk_getsockopt,
+ .sendmsg = xsk_sendmsg,
+ .recvmsg = sock_no_recvmsg,
+ .mmap = xsk_mmap,
+ .sendpage = sock_no_sendpage,
+};
+
+static void xsk_destruct(struct sock *sk)
+{
+ struct xdp_sock *xs = xdp_sk(sk);
+
+ if (!sock_flag(sk, SOCK_DEAD))
+ return;
+
+ xskq_destroy(xs->rx);
+ xskq_destroy(xs->tx);
+ xdp_del_sk_umem(xs->umem, xs);
+ xdp_put_umem(xs->umem);
+
+ sk_refcnt_debug_dec(sk);
+}
+
+static int xsk_create(struct net *net, struct socket *sock, int protocol,
+ int kern)
+{
+ struct sock *sk;
+ struct xdp_sock *xs;
+
+ 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;
+ sk_refcnt_debug_inc(sk);
+
+ xs = xdp_sk(sk);
+ mutex_init(&xs->mutex);
+
+ local_bh_disable();
+ sock_prot_inuse_add(net, &xsk_proto, 1);
+ local_bh_enable();
+
+ return 0;
+}
+
+static const struct net_proto_family xsk_family_ops = {
+ .family = PF_XDP,
+ .create = xsk_create,
+ .owner = THIS_MODULE,
+};
+
+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;
+
+ return 0;
+
+out_proto:
+ proto_unregister(&xsk_proto);
+out:
+ return err;
+}
+
+fs_initcall(xsk_init);