diff options
Diffstat (limited to 'net/xdp')
| -rw-r--r-- | net/xdp/Kconfig | 7 | ||||
| -rw-r--r-- | net/xdp/Makefile | 2 | ||||
| -rw-r--r-- | net/xdp/xdp_umem.c | 260 | ||||
| -rw-r--r-- | net/xdp/xdp_umem.h | 67 | ||||
| -rw-r--r-- | net/xdp/xdp_umem_props.h | 23 | ||||
| -rw-r--r-- | net/xdp/xsk.c | 656 | ||||
| -rw-r--r-- | net/xdp/xsk_queue.c | 73 | ||||
| -rw-r--r-- | net/xdp/xsk_queue.h | 247 |
8 files changed, 1335 insertions, 0 deletions
diff --git a/net/xdp/Kconfig b/net/xdp/Kconfig new file mode 100644 index 0000000..90e4a71 --- /dev/null +++ b/net/xdp/Kconfig @@ -0,0 +1,7 @@ +config XDP_SOCKETS + bool "XDP sockets" + depends on BPF_SYSCALL + default n + help + XDP sockets allows a channel between XDP programs and + userspace applications. diff --git a/net/xdp/Makefile b/net/xdp/Makefile new file mode 100644 index 0000000..074fb2b --- /dev/null +++ b/net/xdp/Makefile @@ -0,0 +1,2 @@ +obj-$(CONFIG_XDP_SOCKETS) += xsk.o xdp_umem.o xsk_queue.o + diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c new file mode 100644 index 0000000..881dfde --- /dev/null +++ b/net/xdp/xdp_umem.c @@ -0,0 +1,260 @@ +// SPDX-License-Identifier: GPL-2.0 +/* XDP user-space packet buffer + * Copyright(c) 2018 Intel Corporation. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + */ + +#include <linux/init.h> +#include <linux/sched/mm.h> +#include <linux/sched/signal.h> +#include <linux/sched/task.h> +#include <linux/uaccess.h> +#include <linux/slab.h> +#include <linux/bpf.h> +#include <linux/mm.h> + +#include "xdp_umem.h" + +#define XDP_UMEM_MIN_FRAME_SIZE 2048 + +int xdp_umem_create(struct xdp_umem **umem) +{ + *umem = kzalloc(sizeof(**umem), GFP_KERNEL); + + if (!(*umem)) + return -ENOMEM; + + return 0; +} + +static void xdp_umem_unpin_pages(struct xdp_umem *umem) +{ + unsigned int i; + + if (umem->pgs) { + for (i = 0; i < umem->npgs; i++) { + struct page *page = umem->pgs[i]; + + set_page_dirty_lock(page); + put_page(page); + } + + kfree(umem->pgs); + umem->pgs = NULL; + } +} + +static void xdp_umem_unaccount_pages(struct xdp_umem *umem) +{ + if (umem->user) { + atomic_long_sub(umem->npgs, &umem->user->locked_vm); + free_uid(umem->user); + } +} + +static void xdp_umem_release(struct xdp_umem *umem) +{ + struct task_struct *task; + struct mm_struct *mm; + + if (umem->fq) { + xskq_destroy(umem->fq); + umem->fq = NULL; + } + + if (umem->cq) { + xskq_destroy(umem->cq); + umem->cq = NULL; + } + + if (umem->pgs) { + xdp_umem_unpin_pages(umem); + + task = get_pid_task(umem->pid, PIDTYPE_PID); + put_pid(umem->pid); + if (!task) + goto out; + mm = get_task_mm(task); + put_task_struct(task); + if (!mm) + goto out; + + mmput(mm); + umem->pgs = NULL; + } + + xdp_umem_unaccount_pages(umem); +out: + kfree(umem); +} + +static void xdp_umem_release_deferred(struct work_struct *work) +{ + struct xdp_umem *umem = container_of(work, struct xdp_umem, work); + + xdp_umem_release(umem); +} + +void xdp_get_umem(struct xdp_umem *umem) +{ + atomic_inc(&umem->users); +} + +void xdp_put_umem(struct xdp_umem *umem) +{ + if (!umem) + return; + + if (atomic_dec_and_test(&umem->users)) { + INIT_WORK(&umem->work, xdp_umem_release_deferred); + schedule_work(&umem->work); + } +} + +static int xdp_umem_pin_pages(struct xdp_umem *umem) +{ + unsigned int gup_flags = FOLL_WRITE; + long npgs; + int err; + + umem->pgs = kcalloc(umem->npgs, sizeof(*umem->pgs), GFP_KERNEL); + if (!umem->pgs) + return -ENOMEM; + + down_write(¤t->mm->mmap_sem); + npgs = get_user_pages(umem->address, umem->npgs, + gup_flags, &umem->pgs[0], NULL); + up_write(¤t->mm->mmap_sem); + + if (npgs != umem->npgs) { + if (npgs >= 0) { + umem->npgs = npgs; + err = -ENOMEM; + goto out_pin; + } + err = npgs; + goto out_pgs; + } + return 0; + +out_pin: + xdp_umem_unpin_pages(umem); +out_pgs: + kfree(umem->pgs); + umem->pgs = NULL; + return err; +} + +static int xdp_umem_account_pages(struct xdp_umem *umem) +{ + unsigned long lock_limit, new_npgs, old_npgs; + + if (capable(CAP_IPC_LOCK)) + return 0; + + lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; + umem->user = get_uid(current_user()); + + do { + old_npgs = atomic_long_read(&umem->user->locked_vm); + new_npgs = old_npgs + umem->npgs; + if (new_npgs > lock_limit) { + free_uid(umem->user); + umem->user = NULL; + return -ENOBUFS; + } + } while (atomic_long_cmpxchg(&umem->user->locked_vm, old_npgs, + new_npgs) != old_npgs); + return 0; +} + +int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr) +{ + u32 frame_size = mr->frame_size, frame_headroom = mr->frame_headroom; + u64 addr = mr->addr, size = mr->len; + unsigned int nframes, nfpp; + int size_chk, err; + + if (!umem) + return -EINVAL; + + if (frame_size < XDP_UMEM_MIN_FRAME_SIZE || frame_size > PAGE_SIZE) { + /* Strictly speaking we could support this, if: + * - huge pages, or* + * - using an IOMMU, or + * - making sure the memory area is consecutive + * but for now, we simply say "computer says no". + */ + return -EINVAL; + } + + if (!is_power_of_2(frame_size)) + return -EINVAL; + + if (!PAGE_ALIGNED(addr)) { + /* Memory area has to be page size aligned. For + * simplicity, this might change. + */ + return -EINVAL; + } + + if ((addr + size) < addr) + return -EINVAL; + + nframes = size / frame_size; + if (nframes == 0 || nframes > UINT_MAX) + return -EINVAL; + + nfpp = PAGE_SIZE / frame_size; + if (nframes < nfpp || nframes % nfpp) + return -EINVAL; + + frame_headroom = ALIGN(frame_headroom, 64); + + size_chk = frame_size - frame_headroom - XDP_PACKET_HEADROOM; + if (size_chk < 0) + return -EINVAL; + + umem->pid = get_task_pid(current, PIDTYPE_PID); + umem->size = (size_t)size; + umem->address = (unsigned long)addr; + umem->props.frame_size = frame_size; + umem->props.nframes = nframes; + umem->frame_headroom = frame_headroom; + umem->npgs = size / PAGE_SIZE; + umem->pgs = NULL; + umem->user = NULL; + + umem->frame_size_log2 = ilog2(frame_size); + umem->nfpp_mask = nfpp - 1; + umem->nfpplog2 = ilog2(nfpp); + atomic_set(&umem->users, 1); + + err = xdp_umem_account_pages(umem); + if (err) + goto out; + + err = xdp_umem_pin_pages(umem); + if (err) + goto out_account; + return 0; + +out_account: + xdp_umem_unaccount_pages(umem); +out: + put_pid(umem->pid); + return err; +} + +bool xdp_umem_validate_queues(struct xdp_umem *umem) +{ + return (umem->fq && umem->cq); +} diff --git a/net/xdp/xdp_umem.h b/net/xdp/xdp_umem.h new file mode 100644 index 0000000..7e0b2fa --- /dev/null +++ b/net/xdp/xdp_umem.h @@ -0,0 +1,67 @@ +/* SPDX-License-Identifier: GPL-2.0 + * XDP user-space packet buffer + * Copyright(c) 2018 Intel Corporation. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + */ + +#ifndef XDP_UMEM_H_ +#define XDP_UMEM_H_ + +#include <linux/mm.h> +#include <linux/if_xdp.h> +#include <linux/workqueue.h> + +#include "xsk_queue.h" +#include "xdp_umem_props.h" + +struct xdp_umem { + struct xsk_queue *fq; + struct xsk_queue *cq; + struct page **pgs; + struct xdp_umem_props props; + u32 npgs; + u32 frame_headroom; + u32 nfpp_mask; + u32 nfpplog2; + u32 frame_size_log2; + struct user_struct *user; + struct pid *pid; + unsigned long address; + size_t size; + atomic_t users; + struct work_struct work; +}; + +static inline char *xdp_umem_get_data(struct xdp_umem *umem, u32 idx) +{ + u64 pg, off; + char *data; + + pg = idx >> umem->nfpplog2; + off = (idx & umem->nfpp_mask) << umem->frame_size_log2; + + data = page_address(umem->pgs[pg]); + return data + off; +} + +static inline char *xdp_umem_get_data_with_headroom(struct xdp_umem *umem, + u32 idx) +{ + return xdp_umem_get_data(umem, idx) + umem->frame_headroom; +} + +bool xdp_umem_validate_queues(struct xdp_umem *umem); +int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr); +void xdp_get_umem(struct xdp_umem *umem); +void xdp_put_umem(struct xdp_umem *umem); +int xdp_umem_create(struct xdp_umem **umem); + +#endif /* XDP_UMEM_H_ */ diff --git a/net/xdp/xdp_umem_props.h b/net/xdp/xdp_umem_props.h new file mode 100644 index 0000000..77fb5da --- /dev/null +++ b/net/xdp/xdp_umem_props.h @@ -0,0 +1,23 @@ +/* SPDX-License-Identifier: GPL-2.0 + * XDP user-space packet buffer + * Copyright(c) 2018 Intel Corporation. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + */ + +#ifndef XDP_UMEM_PROPS_H_ +#define XDP_UMEM_PROPS_H_ + +struct xdp_umem_props { + u32 frame_size; + u32 nframes; +}; + +#endif /* XDP_UMEM_PROPS_H_ */ diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c new file mode 100644 index 0000000..009c5af --- /dev/null +++ b/net/xdp/xsk.c @@ -0,0 +1,656 @@ +// 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. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * 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 <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 !!xs->rx; +} + +static int __xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp) +{ + u32 *id, len = xdp->data_end - xdp->data; + void *buffer; + int err = 0; + + if (xs->dev != xdp->rxq->dev || xs->queue_id != xdp->rxq->queue_index) + return -EINVAL; + + id = xskq_peek_id(xs->umem->fq); + if (!id) + return -ENOSPC; + + buffer = xdp_umem_get_data_with_headroom(xs->umem, *id); + memcpy(buffer, xdp->data, len); + err = xskq_produce_batch_desc(xs->rx, *id, len, + xs->umem->frame_headroom); + if (!err) + xskq_discard_id(xs->umem->fq); + + return err; +} + +int xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp) +{ + int err; + + err = __xsk_rcv(xs, xdp); + if (likely(!err)) + xdp_return_buff(xdp); + else + xs->rx_dropped++; + + return err; +} + +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) +{ + int err; + + err = __xsk_rcv(xs, xdp); + if (!err) + xsk_flush(xs); + else + xs->rx_dropped++; + + return err; +} + +static void xsk_destruct_skb(struct sk_buff *skb) +{ + u32 id = (u32)(long)skb_shinfo(skb)->destructor_arg; + struct xdp_sock *xs = xdp_sk(skb->sk); + + WARN_ON_ONCE(xskq_produce_id(xs->umem->cq, id)); + + sock_wfree(skb); +} + +static int xsk_generic_xmit(struct sock *sk, struct msghdr *m, + size_t total_len) +{ + bool need_wait = !(m->msg_flags & MSG_DONTWAIT); + 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; + if (need_wait) + return -EOPNOTSUPP; + + mutex_lock(&xs->mutex); + + while (xskq_peek_desc(xs->tx, &desc)) { + char *buffer; + u32 id, len; + + if (max_batch-- == 0) { + err = -EAGAIN; + goto out; + } + + if (xskq_reserve_id(xs->umem->cq)) { + err = -EAGAIN; + goto out; + } + + len = desc.len; + if (unlikely(len > xs->dev->mtu)) { + err = -EMSGSIZE; + goto out; + } + + skb = sock_alloc_send_skb(sk, len, !need_wait, &err); + if (unlikely(!skb)) { + err = -EAGAIN; + goto out; + } + + skb_put(skb, len); + id = desc.idx; + buffer = xdp_umem_get_data(xs->umem, id) + desc.offset; + 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)id; + 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) +{ + 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; + + return xsk_generic_xmit(sk, m, total_len); +} + +static unsigned int xsk_poll(struct file *file, struct socket *sock, + struct poll_table_struct *wait) +{ + unsigned int mask = datagram_poll(file, sock, wait); + 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; + + *queue = q; + return 0; +} + +static void __xsk_release(struct xdp_sock *xs) +{ + /* Wait for driver to stop using the xdp socket. */ + synchronize_net(); + + dev_put(xs->dev); +} + +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) { + __xsk_release(xs); + 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 net_device *dev, *dev_curr; + struct xdp_sock *xs = xdp_sk(sk); + struct xdp_umem *old_umem = NULL; + int err = 0; + + if (addr_len < sizeof(struct sockaddr_xdp)) + return -EINVAL; + if (sxdp->sxdp_family != AF_XDP) + return -EINVAL; + + mutex_lock(&xs->mutex); + dev_curr = xs->dev; + 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; + } + + if (sxdp->sxdp_queue_id >= dev->num_rx_queues) { + err = -EINVAL; + goto out_unlock; + } + + if (sxdp->sxdp_flags & XDP_SHARED_UMEM) { + struct xdp_sock *umem_xs; + struct socket *sock; + + 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 != sxdp->sxdp_queue_id) { + err = -EINVAL; + sockfd_put(sock); + goto out_unlock; + } + + xdp_get_umem(umem_xs->umem); + old_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); + } + + /* Rebind? */ + if (dev_curr && (dev_curr != dev || + xs->queue_id != sxdp->sxdp_queue_id)) { + __xsk_release(xs); + if (old_umem) + xdp_put_umem(old_umem); + } + + xs->dev = dev; + xs->queue_id = sxdp->sxdp_queue_id; + + xskq_set_umem(xs->rx, &xs->umem->props); + xskq_set_umem(xs->tx, &xs->umem->props); + +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 (xs->umem) + return -EBUSY; + + if (copy_from_user(&mr, optval, sizeof(mr))) + return -EFAULT; + + mutex_lock(&xs->mutex); + err = xdp_umem_create(&umem); + + err = xdp_umem_reg(umem, &mr); + if (err) { + kfree(umem); + mutex_unlock(&xs->mutex); + return err; + } + + /* 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 (!xs->umem) + return -EINVAL; + + if (copy_from_user(&entries, optval, sizeof(entries))) + return -EFAULT; + + mutex_lock(&xs->mutex); + 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; + } + 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; + unsigned long pfn; + struct page *qpg; + + if (offset == XDP_PGOFF_RX_RING) { + q = xs->rx; + } else if (offset == XDP_PGOFF_TX_RING) { + q = xs->tx; + } else { + if (!xs->umem) + return -EINVAL; + + if (offset == XDP_UMEM_PGOFF_FILL_RING) + q = xs->umem->fq; + else if (offset == XDP_UMEM_PGOFF_COMPLETION_RING) + q = xs->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 = xsk_poll, + .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_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); diff --git a/net/xdp/xsk_queue.c b/net/xdp/xsk_queue.c new file mode 100644 index 0000000..d012e5e --- /dev/null +++ b/net/xdp/xsk_queue.c @@ -0,0 +1,73 @@ +// SPDX-License-Identifier: GPL-2.0 +/* XDP user-space ring structure + * Copyright(c) 2018 Intel Corporation. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + */ + +#include <linux/slab.h> + +#include "xsk_queue.h" + +void xskq_set_umem(struct xsk_queue *q, struct xdp_umem_props *umem_props) +{ + if (!q) + return; + + q->umem_props = *umem_props; +} + +static u32 xskq_umem_get_ring_size(struct xsk_queue *q) +{ + return sizeof(struct xdp_umem_ring) + q->nentries * sizeof(u32); +} + +static u32 xskq_rxtx_get_ring_size(struct xsk_queue *q) +{ + return (sizeof(struct xdp_ring) + + q->nentries * sizeof(struct xdp_desc)); +} + +struct xsk_queue *xskq_create(u32 nentries, bool umem_queue) +{ + struct xsk_queue *q; + gfp_t gfp_flags; + size_t size; + + q = kzalloc(sizeof(*q), GFP_KERNEL); + if (!q) + return NULL; + + q->nentries = nentries; + q->ring_mask = nentries - 1; + + gfp_flags = GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN | + __GFP_COMP | __GFP_NORETRY; + size = umem_queue ? xskq_umem_get_ring_size(q) : + xskq_rxtx_get_ring_size(q); + + q->ring = (struct xdp_ring *)__get_free_pages(gfp_flags, + get_order(size)); + if (!q->ring) { + kfree(q); + return NULL; + } + + return q; +} + +void xskq_destroy(struct xsk_queue *q) +{ + if (!q) + return; + + page_frag_free(q->ring); + kfree(q); +} diff --git a/net/xdp/xsk_queue.h b/net/xdp/xsk_queue.h new file mode 100644 index 0000000..7aa9a53 --- /dev/null +++ b/net/xdp/xsk_queue.h @@ -0,0 +1,247 @@ +/* SPDX-License-Identifier: GPL-2.0 + * XDP user-space ring structure + * Copyright(c) 2018 Intel Corporation. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + */ + +#ifndef _LINUX_XSK_QUEUE_H +#define _LINUX_XSK_QUEUE_H + +#include <linux/types.h> +#include <linux/if_xdp.h> + +#include "xdp_umem_props.h" + +#define RX_BATCH_SIZE 16 + +struct xsk_queue { + struct xdp_umem_props umem_props; + u32 ring_mask; + u32 nentries; + u32 prod_head; + u32 prod_tail; + u32 cons_head; + u32 cons_tail; + struct xdp_ring *ring; + u64 invalid_descs; +}; + +/* Common functions operating for both RXTX and umem queues */ + +static inline u64 xskq_nb_invalid_descs(struct xsk_queue *q) +{ + return q ? q->invalid_descs : 0; +} + +static inline u32 xskq_nb_avail(struct xsk_queue *q, u32 dcnt) +{ + u32 entries = q->prod_tail - q->cons_tail; + + if (entries == 0) { + /* Refresh the local pointer */ + q->prod_tail = READ_ONCE(q->ring->producer); + entries = q->prod_tail - q->cons_tail; + } + + return (entries > dcnt) ? dcnt : entries; +} + +static inline u32 xskq_nb_free(struct xsk_queue *q, u32 producer, u32 dcnt) +{ + u32 free_entries = q->nentries - (producer - q->cons_tail); + + if (free_entries >= dcnt) + return free_entries; + + /* Refresh the local tail pointer */ + q->cons_tail = READ_ONCE(q->ring->consumer); + return q->nentries - (producer - q->cons_tail); +} + +/* UMEM queue */ + +static inline bool xskq_is_valid_id(struct xsk_queue *q, u32 idx) +{ + if (unlikely(idx >= q->umem_props.nframes)) { + q->invalid_descs++; + return false; + } + return true; +} + +static inline u32 *xskq_validate_id(struct xsk_queue *q) +{ + while (q->cons_tail != q->cons_head) { + struct xdp_umem_ring *ring = (struct xdp_umem_ring *)q->ring; + unsigned int idx = q->cons_tail & q->ring_mask; + + if (xskq_is_valid_id(q, ring->desc[idx])) + return &ring->desc[idx]; + + q->cons_tail++; + } + + return NULL; +} + +static inline u32 *xskq_peek_id(struct xsk_queue *q) +{ + struct xdp_umem_ring *ring; + + if (q->cons_tail == q->cons_head) { + WRITE_ONCE(q->ring->consumer, q->cons_tail); + q->cons_head = q->cons_tail + xskq_nb_avail(q, RX_BATCH_SIZE); + + /* Order consumer and data */ + smp_rmb(); + + return xskq_validate_id(q); + } + + ring = (struct xdp_umem_ring *)q->ring; + return &ring->desc[q->cons_tail & q->ring_mask]; +} + +static inline void xskq_discard_id(struct xsk_queue *q) +{ + q->cons_tail++; + (void)xskq_validate_id(q); +} + +static inline int xskq_produce_id(struct xsk_queue *q, u32 id) +{ + struct xdp_umem_ring *ring = (struct xdp_umem_ring *)q->ring; + + ring->desc[q->prod_tail++ & q->ring_mask] = id; + + /* Order producer and data */ + smp_wmb(); + + WRITE_ONCE(q->ring->producer, q->prod_tail); + return 0; +} + +static inline int xskq_reserve_id(struct xsk_queue *q) +{ + if (xskq_nb_free(q, q->prod_head, 1) == 0) + return -ENOSPC; + + q->prod_head++; + return 0; +} + +/* Rx/Tx queue */ + +static inline bool xskq_is_valid_desc(struct xsk_queue *q, struct xdp_desc *d) +{ + u32 buff_len; + + if (unlikely(d->idx >= q->umem_props.nframes)) { + q->invalid_descs++; + return false; + } + + buff_len = q->umem_props.frame_size; + if (unlikely(d->len > buff_len || d->len == 0 || + d->offset > buff_len || d->offset + d->len > buff_len)) { + q->invalid_descs++; + return false; + } + + return true; +} + +static inline struct xdp_desc *xskq_validate_desc(struct xsk_queue *q, + struct xdp_desc *desc) +{ + while (q->cons_tail != q->cons_head) { + struct xdp_rxtx_ring *ring = (struct xdp_rxtx_ring *)q->ring; + unsigned int idx = q->cons_tail & q->ring_mask; + + if (xskq_is_valid_desc(q, &ring->desc[idx])) { + if (desc) + *desc = ring->desc[idx]; + return desc; + } + + q->cons_tail++; + } + + return NULL; +} + +static inline struct xdp_desc *xskq_peek_desc(struct xsk_queue *q, + struct xdp_desc *desc) +{ + struct xdp_rxtx_ring *ring; + + if (q->cons_tail == q->cons_head) { + WRITE_ONCE(q->ring->consumer, q->cons_tail); + q->cons_head = q->cons_tail + xskq_nb_avail(q, RX_BATCH_SIZE); + + /* Order consumer and data */ + smp_rmb(); + + return xskq_validate_desc(q, desc); + } + + ring = (struct xdp_rxtx_ring *)q->ring; + *desc = ring->desc[q->cons_tail & q->ring_mask]; + return desc; +} + +static inline void xskq_discard_desc(struct xsk_queue *q) +{ + q->cons_tail++; + (void)xskq_validate_desc(q, NULL); +} + +static inline int xskq_produce_batch_desc(struct xsk_queue *q, + u32 id, u32 len, u16 offset) +{ + struct xdp_rxtx_ring *ring = (struct xdp_rxtx_ring *)q->ring; + unsigned int idx; + + if (xskq_nb_free(q, q->prod_head, 1) == 0) + return -ENOSPC; + + idx = (q->prod_head++) & q->ring_mask; + ring->desc[idx].idx = id; + ring->desc[idx].len = len; + ring->desc[idx].offset = offset; + + return 0; +} + +static inline void xskq_produce_flush_desc(struct xsk_queue *q) +{ + /* Order producer and data */ + smp_wmb(); + + q->prod_tail = q->prod_head, + WRITE_ONCE(q->ring->producer, q->prod_tail); +} + +static inline bool xskq_full_desc(struct xsk_queue *q) +{ + return (xskq_nb_avail(q, q->nentries) == q->nentries); +} + +static inline bool xskq_empty_desc(struct xsk_queue *q) +{ + return (xskq_nb_free(q, q->prod_tail, 1) == q->nentries); +} + +void xskq_set_umem(struct xsk_queue *q, struct xdp_umem_props *umem_props); +struct xsk_queue *xskq_create(u32 nentries, bool umem_queue); +void xskq_destroy(struct xsk_queue *q_ops); + +#endif /* _LINUX_XSK_QUEUE_H */ |
