diff options
Diffstat (limited to 'net/xdp')
| -rw-r--r-- | net/xdp/Kconfig | 7 | ||||
| -rw-r--r-- | net/xdp/Makefile | 1 | ||||
| -rw-r--r-- | net/xdp/xdp_umem.c | 361 | ||||
| -rw-r--r-- | net/xdp/xdp_umem.h | 30 | ||||
| -rw-r--r-- | net/xdp/xdp_umem_props.h | 14 | ||||
| -rw-r--r-- | net/xdp/xsk.c | 788 | ||||
| -rw-r--r-- | net/xdp/xsk_queue.c | 63 | ||||
| -rw-r--r-- | net/xdp/xsk_queue.h | 265 |
8 files changed, 1529 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..04f0731 --- /dev/null +++ b/net/xdp/Makefile @@ -0,0 +1 @@ +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..7eb4948 --- /dev/null +++ b/net/xdp/xdp_umem.c @@ -0,0 +1,361 @@ +// SPDX-License-Identifier: GPL-2.0 +/* XDP user-space packet buffer + * Copyright(c) 2018 Intel Corporation. + */ + +#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" +#include "xsk_queue.h" + +#define XDP_UMEM_MIN_CHUNK_SIZE 2048 + +void xdp_add_sk_umem(struct xdp_umem *umem, struct xdp_sock *xs) +{ + unsigned long flags; + + spin_lock_irqsave(&umem->xsk_list_lock, flags); + list_add_rcu(&xs->list, &umem->xsk_list); + spin_unlock_irqrestore(&umem->xsk_list_lock, flags); +} + +void xdp_del_sk_umem(struct xdp_umem *umem, struct xdp_sock *xs) +{ + unsigned long flags; + + if (xs->dev) { + spin_lock_irqsave(&umem->xsk_list_lock, flags); + list_del_rcu(&xs->list); + spin_unlock_irqrestore(&umem->xsk_list_lock, flags); + + if (umem->zc) + synchronize_net(); + } +} + +int xdp_umem_assign_dev(struct xdp_umem *umem, struct net_device *dev, + u32 queue_id, u16 flags) +{ + bool force_zc, force_copy; + struct netdev_bpf bpf; + int err; + + force_zc = flags & XDP_ZEROCOPY; + force_copy = flags & XDP_COPY; + + if (force_zc && force_copy) + return -EINVAL; + + if (force_copy) + return 0; + + dev_hold(dev); + + if (dev->netdev_ops->ndo_bpf && dev->netdev_ops->ndo_xsk_async_xmit) { + bpf.command = XDP_QUERY_XSK_UMEM; + + rtnl_lock(); + err = dev->netdev_ops->ndo_bpf(dev, &bpf); + rtnl_unlock(); + + if (err) { + dev_put(dev); + return force_zc ? -ENOTSUPP : 0; + } + + bpf.command = XDP_SETUP_XSK_UMEM; + bpf.xsk.umem = umem; + bpf.xsk.queue_id = queue_id; + + rtnl_lock(); + err = dev->netdev_ops->ndo_bpf(dev, &bpf); + rtnl_unlock(); + + if (err) { + dev_put(dev); + return force_zc ? err : 0; /* fail or fallback */ + } + + umem->dev = dev; + umem->queue_id = queue_id; + umem->zc = true; + return 0; + } + + dev_put(dev); + return force_zc ? -ENOTSUPP : 0; /* fail or fallback */ +} + +static void xdp_umem_clear_dev(struct xdp_umem *umem) +{ + struct netdev_bpf bpf; + int err; + + if (umem->dev) { + bpf.command = XDP_SETUP_XSK_UMEM; + bpf.xsk.umem = NULL; + bpf.xsk.queue_id = umem->queue_id; + + rtnl_lock(); + err = umem->dev->netdev_ops->ndo_bpf(umem->dev, &bpf); + rtnl_unlock(); + + if (err) + WARN(1, "failed to disable umem!\n"); + + dev_put(umem->dev); + umem->dev = NULL; + } +} + +static void xdp_umem_unpin_pages(struct xdp_umem *umem) +{ + unsigned int i; + + 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) +{ + 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; + + xdp_umem_clear_dev(umem); + + if (umem->fq) { + xskq_destroy(umem->fq); + umem->fq = NULL; + } + + if (umem->cq) { + xskq_destroy(umem->cq); + umem->cq = NULL; + } + + 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); + kfree(umem->pages); + umem->pages = 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) +{ + refcount_inc(&umem->users); +} + +void xdp_put_umem(struct xdp_umem *umem) +{ + if (!umem) + return; + + if (refcount_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; +} + +static int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr) +{ + u32 chunk_size = mr->chunk_size, headroom = mr->headroom; + unsigned int chunks, chunks_per_page; + u64 addr = mr->addr, size = mr->len; + int size_chk, err, i; + + if (chunk_size < XDP_UMEM_MIN_CHUNK_SIZE || chunk_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(chunk_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; + + chunks = (unsigned int)div_u64(size, chunk_size); + if (chunks == 0) + return -EINVAL; + + chunks_per_page = PAGE_SIZE / chunk_size; + if (chunks < chunks_per_page || chunks % chunks_per_page) + return -EINVAL; + + headroom = ALIGN(headroom, 64); + + size_chk = chunk_size - headroom - XDP_PACKET_HEADROOM; + if (size_chk < 0) + return -EINVAL; + + umem->pid = get_task_pid(current, PIDTYPE_PID); + umem->address = (unsigned long)addr; + umem->props.chunk_mask = ~((u64)chunk_size - 1); + umem->props.size = size; + umem->headroom = headroom; + umem->chunk_size_nohr = chunk_size - headroom; + umem->npgs = size / PAGE_SIZE; + umem->pgs = NULL; + umem->user = NULL; + INIT_LIST_HEAD(&umem->xsk_list); + spin_lock_init(&umem->xsk_list_lock); + + refcount_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; + + umem->pages = kcalloc(umem->npgs, sizeof(*umem->pages), GFP_KERNEL); + if (!umem->pages) { + err = -ENOMEM; + goto out_account; + } + + for (i = 0; i < umem->npgs; i++) + umem->pages[i].addr = page_address(umem->pgs[i]); + + return 0; + +out_account: + xdp_umem_unaccount_pages(umem); +out: + put_pid(umem->pid); + return err; +} + +struct xdp_umem *xdp_umem_create(struct xdp_umem_reg *mr) +{ + struct xdp_umem *umem; + int err; + + umem = kzalloc(sizeof(*umem), GFP_KERNEL); + if (!umem) + return ERR_PTR(-ENOMEM); + + err = xdp_umem_reg(umem, mr); + if (err) { + kfree(umem); + return ERR_PTR(err); + } + + return umem; +} + +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..f115603 --- /dev/null +++ b/net/xdp/xdp_umem.h @@ -0,0 +1,30 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* XDP user-space packet buffer + * Copyright(c) 2018 Intel Corporation. + */ + +#ifndef XDP_UMEM_H_ +#define XDP_UMEM_H_ + +#include <net/xdp_sock.h> + +static inline char *xdp_umem_get_data(struct xdp_umem *umem, u64 addr) +{ + return umem->pages[addr >> PAGE_SHIFT].addr + (addr & (PAGE_SIZE - 1)); +} + +static inline dma_addr_t xdp_umem_get_dma(struct xdp_umem *umem, u64 addr) +{ + return umem->pages[addr >> PAGE_SHIFT].dma + (addr & (PAGE_SIZE - 1)); +} + +int xdp_umem_assign_dev(struct xdp_umem *umem, struct net_device *dev, + u32 queue_id, u16 flags); +bool xdp_umem_validate_queues(struct xdp_umem *umem); +void xdp_get_umem(struct xdp_umem *umem); +void xdp_put_umem(struct xdp_umem *umem); +void xdp_add_sk_umem(struct xdp_umem *umem, struct xdp_sock *xs); +void xdp_del_sk_umem(struct xdp_umem *umem, struct xdp_sock *xs); +struct xdp_umem *xdp_umem_create(struct xdp_umem_reg *mr); + +#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..40eab10 --- /dev/null +++ b/net/xdp/xdp_umem_props.h @@ -0,0 +1,14 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* XDP user-space packet buffer + * Copyright(c) 2018 Intel Corporation. + */ + +#ifndef XDP_UMEM_PROPS_H_ +#define XDP_UMEM_PROPS_H_ + +struct xdp_umem_props { + u64 chunk_mask; + u64 size; +}; + +#endif /* XDP_UMEM_PROPS_H_ */ diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c new file mode 100644 index 0000000..c6ed245 --- /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); diff --git a/net/xdp/xsk_queue.c b/net/xdp/xsk_queue.c new file mode 100644 index 0000000..6c32e92 --- /dev/null +++ b/net/xdp/xsk_queue.c @@ -0,0 +1,63 @@ +// SPDX-License-Identifier: GPL-2.0 +/* XDP user-space ring structure + * Copyright(c) 2018 Intel Corporation. + */ + +#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(u64); +} + +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..ef6a6f0 --- /dev/null +++ b/net/xdp/xsk_queue.h @@ -0,0 +1,265 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* XDP user-space ring structure + * Copyright(c) 2018 Intel Corporation. + */ + +#ifndef _LINUX_XSK_QUEUE_H +#define _LINUX_XSK_QUEUE_H + +#include <linux/types.h> +#include <linux/if_xdp.h> +#include <net/xdp_sock.h> + +#define RX_BATCH_SIZE 16 +#define LAZY_UPDATE_THRESHOLD 128 + +struct xdp_ring { + u32 producer ____cacheline_aligned_in_smp; + u32 consumer ____cacheline_aligned_in_smp; +}; + +/* Used for the RX and TX queues for packets */ +struct xdp_rxtx_ring { + struct xdp_ring ptrs; + struct xdp_desc desc[0] ____cacheline_aligned_in_smp; +}; + +/* Used for the fill and completion queues for buffers */ +struct xdp_umem_ring { + struct xdp_ring ptrs; + u64 desc[0] ____cacheline_aligned_in_smp; +}; + +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_lazy(struct xsk_queue *q, u32 producer) +{ + return q->nentries - (producer - q->cons_tail); +} + +static inline u32 xskq_nb_free(struct xsk_queue *q, u32 producer, u32 dcnt) +{ + u32 free_entries = xskq_nb_free_lazy(q, producer); + + 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_addr(struct xsk_queue *q, u64 addr) +{ + if (addr >= q->umem_props.size) { + q->invalid_descs++; + return false; + } + + return true; +} + +static inline u64 *xskq_validate_addr(struct xsk_queue *q, u64 *addr) +{ + 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; + + *addr = READ_ONCE(ring->desc[idx]) & q->umem_props.chunk_mask; + if (xskq_is_valid_addr(q, *addr)) + return addr; + + q->cons_tail++; + } + + return NULL; +} + +static inline u64 *xskq_peek_addr(struct xsk_queue *q, u64 *addr) +{ + 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_addr(q, addr); +} + +static inline void xskq_discard_addr(struct xsk_queue *q) +{ + q->cons_tail++; +} + +static inline int xskq_produce_addr(struct xsk_queue *q, u64 addr) +{ + struct xdp_umem_ring *ring = (struct xdp_umem_ring *)q->ring; + + if (xskq_nb_free(q, q->prod_tail, LAZY_UPDATE_THRESHOLD) == 0) + return -ENOSPC; + + ring->desc[q->prod_tail++ & q->ring_mask] = addr; + + /* Order producer and data */ + smp_wmb(); + + WRITE_ONCE(q->ring->producer, q->prod_tail); + return 0; +} + +static inline int xskq_produce_addr_lazy(struct xsk_queue *q, u64 addr) +{ + struct xdp_umem_ring *ring = (struct xdp_umem_ring *)q->ring; + + if (xskq_nb_free(q, q->prod_head, LAZY_UPDATE_THRESHOLD) == 0) + return -ENOSPC; + + ring->desc[q->prod_head++ & q->ring_mask] = addr; + return 0; +} + +static inline void xskq_produce_flush_addr_n(struct xsk_queue *q, + u32 nb_entries) +{ + /* Order producer and data */ + smp_wmb(); + + q->prod_tail += nb_entries; + WRITE_ONCE(q->ring->producer, q->prod_tail); +} + +static inline int xskq_reserve_addr(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) +{ + if (!xskq_is_valid_addr(q, d->addr)) + return false; + + if (((d->addr + d->len) & q->umem_props.chunk_mask) != + (d->addr & q->umem_props.chunk_mask)) { + 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; + + *desc = READ_ONCE(ring->desc[idx]); + if (xskq_is_valid_desc(q, desc)) + return desc; + + q->cons_tail++; + } + + return NULL; +} + +static inline struct xdp_desc *xskq_peek_desc(struct xsk_queue *q, + struct xdp_desc *desc) +{ + 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); +} + +static inline void xskq_discard_desc(struct xsk_queue *q) +{ + q->cons_tail++; +} + +static inline int xskq_produce_batch_desc(struct xsk_queue *q, + u64 addr, u32 len) +{ + 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].addr = addr; + ring->desc[idx].len = len; + + 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 */ |
