net/xdp/xsk.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* XDP sockets
   3  *
   4  * AF_XDP sockets allows a channel between XDP programs and userspace
   5  * applications.
   6  * Copyright(c) 2018 Intel Corporation.
   7  *
   8  * Author(s): Björn Töpel <bjorn.topel@intel.com>
   9  *            Magnus Karlsson <magnus.karlsson@intel.com>
  10  */
  11
  12 #define pr_fmt(fmt) "AF_XDP: %s: " fmt, __func__
  13
  14 #include <linux/if_xdp.h>
  15 #include <linux/init.h>
  16 #include <linux/sched/mm.h>
  17 #include <linux/sched/signal.h>
  18 #include <linux/sched/task.h>
  19 #include <linux/socket.h>
  20 #include <linux/file.h>
  21 #include <linux/uaccess.h>
  22 #include <linux/net.h>
  23 #include <linux/netdevice.h>
  24 #include <linux/rculist.h>
  25 #include <net/xdp_sock_drv.h>
  26 #include <net/busy_poll.h>
  27 #include <net/xdp.h>
  28
  29 #include "xsk_queue.h"
  30 #include "xdp_umem.h"
  31 #include "xsk.h"
  32
  33 #define TX_BATCH_SIZE 16
  34
  35 static DEFINE_PER_CPU(struct list_head, xskmap_flush_list);
  36
  37 void xsk_set_rx_need_wakeup(struct xsk_buff_pool *pool)
  38 {
  39         if (pool->cached_need_wakeup & XDP_WAKEUP_RX)
  40                 return;
  41
  42         pool->fq->ring->flags |= XDP_RING_NEED_WAKEUP;
  43         pool->cached_need_wakeup |= XDP_WAKEUP_RX;
  44 }
  45 EXPORT_SYMBOL(xsk_set_rx_need_wakeup);
  46
  47 void xsk_set_tx_need_wakeup(struct xsk_buff_pool *pool)
  48 {
  49         struct xdp_sock *xs;
  50
  51         if (pool->cached_need_wakeup & XDP_WAKEUP_TX)
  52                 return;
  53
  54         rcu_read_lock();
  55         list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) {
  56                 xs->tx->ring->flags |= XDP_RING_NEED_WAKEUP;
  57         }
  58         rcu_read_unlock();
  59
  60         pool->cached_need_wakeup |= XDP_WAKEUP_TX;
  61 }
  62 EXPORT_SYMBOL(xsk_set_tx_need_wakeup);
  63
  64 void xsk_clear_rx_need_wakeup(struct xsk_buff_pool *pool)
  65 {
  66         if (!(pool->cached_need_wakeup & XDP_WAKEUP_RX))
  67                 return;
  68
  69         pool->fq->ring->flags &= ~XDP_RING_NEED_WAKEUP;
  70         pool->cached_need_wakeup &= ~XDP_WAKEUP_RX;
  71 }
  72 EXPORT_SYMBOL(xsk_clear_rx_need_wakeup);
  73
  74 void xsk_clear_tx_need_wakeup(struct xsk_buff_pool *pool)
  75 {
  76         struct xdp_sock *xs;
  77
  78         if (!(pool->cached_need_wakeup & XDP_WAKEUP_TX))
  79                 return;
  80
  81         rcu_read_lock();
  82         list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) {
  83                 xs->tx->ring->flags &= ~XDP_RING_NEED_WAKEUP;
  84         }
  85         rcu_read_unlock();
  86
  87         pool->cached_need_wakeup &= ~XDP_WAKEUP_TX;
  88 }
  89 EXPORT_SYMBOL(xsk_clear_tx_need_wakeup);
  90
  91 bool xsk_uses_need_wakeup(struct xsk_buff_pool *pool)
  92 {
  93         return pool->uses_need_wakeup;
  94 }
  95 EXPORT_SYMBOL(xsk_uses_need_wakeup);
  96
  97 struct xsk_buff_pool *xsk_get_pool_from_qid(struct net_device *dev,
  98                                             u16 queue_id)
  99 {
 100         if (queue_id < dev->real_num_rx_queues)
 101                 return dev->_rx[queue_id].pool;
 102         if (queue_id < dev->real_num_tx_queues)
 103                 return dev->_tx[queue_id].pool;
 104
 105         return NULL;
 106 }
 107 EXPORT_SYMBOL(xsk_get_pool_from_qid);
 108
 109 void xsk_clear_pool_at_qid(struct net_device *dev, u16 queue_id)
 110 {
 111         if (queue_id < dev->num_rx_queues)
 112                 dev->_rx[queue_id].pool = NULL;
 113         if (queue_id < dev->num_tx_queues)
 114                 dev->_tx[queue_id].pool = NULL;
 115 }
 116
 117 /* The buffer pool is stored both in the _rx struct and the _tx struct as we do
 118  * not know if the device has more tx queues than rx, or the opposite.
 119  * This might also change during run time.
 120  */
 121 int xsk_reg_pool_at_qid(struct net_device *dev, struct xsk_buff_pool *pool,
 122                         u16 queue_id)
 123 {
 124         if (queue_id >= max_t(unsigned int,
 125                               dev->real_num_rx_queues,
 126                               dev->real_num_tx_queues))
 127                 return -EINVAL;
 128
 129         if (queue_id < dev->real_num_rx_queues)
 130                 dev->_rx[queue_id].pool = pool;
 131         if (queue_id < dev->real_num_tx_queues)
 132                 dev->_tx[queue_id].pool = pool;
 133
 134         return 0;
 135 }
 136
 137 void xp_release(struct xdp_buff_xsk *xskb)
 138 {
 139         xskb->pool->free_heads[xskb->pool->free_heads_cnt++] = xskb;
 140 }
 141
 142 static u64 xp_get_handle(struct xdp_buff_xsk *xskb)
 143 {
 144         u64 offset = xskb->xdp.data - xskb->xdp.data_hard_start;
 145
 146         offset += xskb->pool->headroom;
 147         if (!xskb->pool->unaligned)
 148                 return xskb->orig_addr + offset;
 149         return xskb->orig_addr + (offset << XSK_UNALIGNED_BUF_OFFSET_SHIFT);
 150 }
 151
 152 static int __xsk_rcv_zc(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len)
 153 {
 154         struct xdp_buff_xsk *xskb = container_of(xdp, struct xdp_buff_xsk, xdp);
 155         u64 addr;
 156         int err;
 157
 158         addr = xp_get_handle(xskb);
 159         err = xskq_prod_reserve_desc(xs->rx, addr, len);
 160         if (err) {
 161                 xs->rx_queue_full++;
 162                 return err;
 163         }
 164
 165         xp_release(xskb);
 166         return 0;
 167 }
 168
 169 static void xsk_copy_xdp(struct xdp_buff *to, struct xdp_buff *from, u32 len)
 170 {
 171         void *from_buf, *to_buf;
 172         u32 metalen;
 173
 174         if (unlikely(xdp_data_meta_unsupported(from))) {
 175                 from_buf = from->data;
 176                 to_buf = to->data;
 177                 metalen = 0;
 178         } else {
 179                 from_buf = from->data_meta;
 180                 metalen = from->data - from->data_meta;
 181                 to_buf = to->data - metalen;
 182         }
 183
 184         memcpy(to_buf, from_buf, len + metalen);
 185 }
 186
 187 static int __xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len,
 188                      bool explicit_free)
 189 {
 190         struct xdp_buff *xsk_xdp;
 191         int err;
 192
 193         if (len > xsk_pool_get_rx_frame_size(xs->pool)) {
 194                 xs->rx_dropped++;
 195                 return -ENOSPC;
 196         }
 197
 198         xsk_xdp = xsk_buff_alloc(xs->pool);
 199         if (!xsk_xdp) {
 200                 xs->rx_dropped++;
 201                 return -ENOSPC;
 202         }
 203
 204         xsk_copy_xdp(xsk_xdp, xdp, len);
 205         err = __xsk_rcv_zc(xs, xsk_xdp, len);
 206         if (err) {
 207                 xsk_buff_free(xsk_xdp);
 208                 return err;
 209         }
 210         if (explicit_free)
 211                 xdp_return_buff(xdp);
 212         return 0;
 213 }
 214
 215 static bool xsk_tx_writeable(struct xdp_sock *xs)
 216 {
 217         if (xskq_cons_present_entries(xs->tx) > xs->tx->nentries / 2)
 218                 return false;
 219
 220         return true;
 221 }
 222
 223 static bool xsk_is_bound(struct xdp_sock *xs)
 224 {
 225         if (READ_ONCE(xs->state) == XSK_BOUND) {
 226                 /* Matches smp_wmb() in bind(). */
 227                 smp_rmb();
 228                 return true;
 229         }
 230         return false;
 231 }
 232
 233 static int xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp,
 234                    bool explicit_free)
 235 {
 236         u32 len;
 237
 238         if (!xsk_is_bound(xs))
 239                 return -EINVAL;
 240
 241         if (xs->dev != xdp->rxq->dev || xs->queue_id != xdp->rxq->queue_index)
 242                 return -EINVAL;
 243
 244         sk_mark_napi_id_once_xdp(&xs->sk, xdp);
 245         len = xdp->data_end - xdp->data;
 246
 247         return xdp->rxq->mem.type == MEM_TYPE_XSK_BUFF_POOL ?
 248                 __xsk_rcv_zc(xs, xdp, len) :
 249                 __xsk_rcv(xs, xdp, len, explicit_free);
 250 }
 251
 252 static void xsk_flush(struct xdp_sock *xs)
 253 {
 254         xskq_prod_submit(xs->rx);
 255         __xskq_cons_release(xs->pool->fq);
 256         sock_def_readable(&xs->sk);
 257 }
 258
 259 int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
 260 {
 261         int err;
 262
 263         spin_lock_bh(&xs->rx_lock);
 264         err = xsk_rcv(xs, xdp, false);
 265         xsk_flush(xs);
 266         spin_unlock_bh(&xs->rx_lock);
 267         return err;
 268 }
 269
 270 int __xsk_map_redirect(struct xdp_sock *xs, struct xdp_buff *xdp)
 271 {
 272         struct list_head *flush_list = this_cpu_ptr(&xskmap_flush_list);
 273         int err;
 274
 275         err = xsk_rcv(xs, xdp, true);
 276         if (err)
 277                 return err;
 278
 279         if (!xs->flush_node.prev)
 280                 list_add(&xs->flush_node, flush_list);
 281
 282         return 0;
 283 }
 284
 285 void __xsk_map_flush(void)
 286 {
 287         struct list_head *flush_list = this_cpu_ptr(&xskmap_flush_list);
 288         struct xdp_sock *xs, *tmp;
 289
 290         list_for_each_entry_safe(xs, tmp, flush_list, flush_node) {
 291                 xsk_flush(xs);
 292                 __list_del_clearprev(&xs->flush_node);
 293         }
 294 }
 295
 296 void xsk_tx_completed(struct xsk_buff_pool *pool, u32 nb_entries)
 297 {
 298         xskq_prod_submit_n(pool->cq, nb_entries);
 299 }
 300 EXPORT_SYMBOL(xsk_tx_completed);
 301
 302 void xsk_tx_release(struct xsk_buff_pool *pool)
 303 {
 304         struct xdp_sock *xs;
 305
 306         rcu_read_lock();
 307         list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) {
 308                 __xskq_cons_release(xs->tx);
 309                 if (xsk_tx_writeable(xs))
 310                         xs->sk.sk_write_space(&xs->sk);
 311         }
 312         rcu_read_unlock();
 313 }
 314 EXPORT_SYMBOL(xsk_tx_release);
 315
 316 bool xsk_tx_peek_desc(struct xsk_buff_pool *pool, struct xdp_desc *desc)
 317 {
 318         struct xdp_sock *xs;
 319
 320         rcu_read_lock();
 321         list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) {
 322                 if (!xskq_cons_peek_desc(xs->tx, desc, pool)) {
 323                         xs->tx->queue_empty_descs++;
 324                         continue;
 325                 }
 326
 327                 /* This is the backpressure mechanism for the Tx path.
 328                  * Reserve space in the completion queue and only proceed
 329                  * if there is space in it. This avoids having to implement
 330                  * any buffering in the Tx path.
 331                  */
 332                 if (xskq_prod_reserve_addr(pool->cq, desc->addr))
 333                         goto out;
 334
 335                 xskq_cons_release(xs->tx);
 336                 rcu_read_unlock();
 337                 return true;
 338         }
 339
 340 out:
 341         rcu_read_unlock();
 342         return false;
 343 }
 344 EXPORT_SYMBOL(xsk_tx_peek_desc);
 345
 346 static u32 xsk_tx_peek_release_fallback(struct xsk_buff_pool *pool, struct xdp_desc *descs,
 347                                         u32 max_entries)
 348 {
 349         u32 nb_pkts = 0;
 350
 351         while (nb_pkts < max_entries && xsk_tx_peek_desc(pool, &descs[nb_pkts]))
 352                 nb_pkts++;
 353
 354         xsk_tx_release(pool);
 355         return nb_pkts;
 356 }
 357
 358 u32 xsk_tx_peek_release_desc_batch(struct xsk_buff_pool *pool, struct xdp_desc *descs,
 359                                    u32 max_entries)
 360 {
 361         struct xdp_sock *xs;
 362         u32 nb_pkts;
 363
 364         rcu_read_lock();
 365         if (!list_is_singular(&pool->xsk_tx_list)) {
 366                 /* Fallback to the non-batched version */
 367                 rcu_read_unlock();
 368                 return xsk_tx_peek_release_fallback(pool, descs, max_entries);
 369         }
 370
 371         xs = list_first_or_null_rcu(&pool->xsk_tx_list, struct xdp_sock, tx_list);
 372         if (!xs) {
 373                 nb_pkts = 0;
 374                 goto out;
 375         }
 376
 377         nb_pkts = xskq_cons_peek_desc_batch(xs->tx, descs, pool, max_entries);
 378         if (!nb_pkts) {
 379                 xs->tx->queue_empty_descs++;
 380                 goto out;
 381         }
 382
 383         /* This is the backpressure mechanism for the Tx path. Try to
 384          * reserve space in the completion queue for all packets, but
 385          * if there are fewer slots available, just process that many
 386          * packets. This avoids having to implement any buffering in
 387          * the Tx path.
 388          */
 389         nb_pkts = xskq_prod_reserve_addr_batch(pool->cq, descs, nb_pkts);
 390         if (!nb_pkts)
 391                 goto out;
 392
 393         xskq_cons_release_n(xs->tx, nb_pkts);
 394         __xskq_cons_release(xs->tx);
 395         xs->sk.sk_write_space(&xs->sk);
 396
 397 out:
 398         rcu_read_unlock();
 399         return nb_pkts;
 400 }
 401 EXPORT_SYMBOL(xsk_tx_peek_release_desc_batch);
 402
 403 static int xsk_wakeup(struct xdp_sock *xs, u8 flags)
 404 {
 405         struct net_device *dev = xs->dev;
 406         int err;
 407
 408         rcu_read_lock();
 409         err = dev->netdev_ops->ndo_xsk_wakeup(dev, xs->queue_id, flags);
 410         rcu_read_unlock();
 411
 412         return err;
 413 }
 414
 415 static int xsk_zc_xmit(struct xdp_sock *xs)
 416 {
 417         return xsk_wakeup(xs, XDP_WAKEUP_TX);
 418 }
 419
 420 static void xsk_destruct_skb(struct sk_buff *skb)
 421 {
 422         u64 addr = (u64)(long)skb_shinfo(skb)->destructor_arg;
 423         struct xdp_sock *xs = xdp_sk(skb->sk);
 424         unsigned long flags;
 425
 426         spin_lock_irqsave(&xs->pool->cq_lock, flags);
 427         xskq_prod_submit_addr(xs->pool->cq, addr);
 428         spin_unlock_irqrestore(&xs->pool->cq_lock, flags);
 429
 430         sock_wfree(skb);
 431 }
 432
 433 static int xsk_generic_xmit(struct sock *sk)
 434 {
 435         struct xdp_sock *xs = xdp_sk(sk);
 436         u32 max_batch = TX_BATCH_SIZE;
 437         bool sent_frame = false;
 438         struct xdp_desc desc;
 439         struct sk_buff *skb;
 440         unsigned long flags;
 441         int err = 0;
 442
 443         mutex_lock(&xs->mutex);
 444
 445         if (xs->queue_id >= xs->dev->real_num_tx_queues)
 446                 goto out;
 447
 448         while (xskq_cons_peek_desc(xs->tx, &desc, xs->pool)) {
 449                 char *buffer;
 450                 u64 addr;
 451                 u32 len;
 452
 453                 if (max_batch-- == 0) {
 454                         err = -EAGAIN;
 455                         goto out;
 456                 }
 457
 458                 len = desc.len;
 459                 skb = sock_alloc_send_skb(sk, len, 1, &err);
 460                 if (unlikely(!skb))
 461                         goto out;
 462
 463                 skb_put(skb, len);
 464                 addr = desc.addr;
 465                 buffer = xsk_buff_raw_get_data(xs->pool, addr);
 466                 err = skb_store_bits(skb, 0, buffer, len);
 467                 /* This is the backpressure mechanism for the Tx path.
 468                  * Reserve space in the completion queue and only proceed
 469                  * if there is space in it. This avoids having to implement
 470                  * any buffering in the Tx path.
 471                  */
 472                 spin_lock_irqsave(&xs->pool->cq_lock, flags);
 473                 if (unlikely(err) || xskq_prod_reserve(xs->pool->cq)) {
 474                         spin_unlock_irqrestore(&xs->pool->cq_lock, flags);
 475                         kfree_skb(skb);
 476                         goto out;
 477                 }
 478                 spin_unlock_irqrestore(&xs->pool->cq_lock, flags);
 479
 480                 skb->dev = xs->dev;
 481                 skb->priority = sk->sk_priority;
 482                 skb->mark = sk->sk_mark;
 483                 skb_shinfo(skb)->destructor_arg = (void *)(long)desc.addr;
 484                 skb->destructor = xsk_destruct_skb;
 485
 486                 err = __dev_direct_xmit(skb, xs->queue_id);
 487                 if  (err == NETDEV_TX_BUSY) {
 488                         /* Tell user-space to retry the send */
 489                         skb->destructor = sock_wfree;
 490                         spin_lock_irqsave(&xs->pool->cq_lock, flags);
 491                         xskq_prod_cancel(xs->pool->cq);
 492                         spin_unlock_irqrestore(&xs->pool->cq_lock, flags);
 493                         /* Free skb without triggering the perf drop trace */
 494                         consume_skb(skb);
 495                         err = -EAGAIN;
 496                         goto out;
 497                 }
 498
 499                 xskq_cons_release(xs->tx);
 500                 /* Ignore NET_XMIT_CN as packet might have been sent */
 501                 if (err == NET_XMIT_DROP) {
 502                         /* SKB completed but not sent */
 503                         err = -EBUSY;
 504                         goto out;
 505                 }
 506
 507                 sent_frame = true;
 508         }
 509
 510         xs->tx->queue_empty_descs++;
 511
 512 out:
 513         if (sent_frame)
 514                 if (xsk_tx_writeable(xs))
 515                         sk->sk_write_space(sk);
 516
 517         mutex_unlock(&xs->mutex);
 518         return err;
 519 }
 520
 521 static int __xsk_sendmsg(struct sock *sk)
 522 {
 523         struct xdp_sock *xs = xdp_sk(sk);
 524
 525         if (unlikely(!(xs->dev->flags & IFF_UP)))
 526                 return -ENETDOWN;
 527         if (unlikely(!xs->tx))
 528                 return -ENOBUFS;
 529
 530         return xs->zc ? xsk_zc_xmit(xs) : xsk_generic_xmit(sk);
 531 }
 532
 533 static bool xsk_no_wakeup(struct sock *sk)
 534 {
 535 #ifdef CONFIG_NET_RX_BUSY_POLL
 536         /* Prefer busy-polling, skip the wakeup. */
 537         return READ_ONCE(sk->sk_prefer_busy_poll) && READ_ONCE(sk->sk_ll_usec) &&
 538                 READ_ONCE(sk->sk_napi_id) >= MIN_NAPI_ID;
 539 #else
 540         return false;
 541 #endif
 542 }
 543
 544 static int xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len)
 545 {
 546         bool need_wait = !(m->msg_flags & MSG_DONTWAIT);
 547         struct sock *sk = sock->sk;
 548         struct xdp_sock *xs = xdp_sk(sk);
 549         struct xsk_buff_pool *pool;
 550
 551         if (unlikely(!xsk_is_bound(xs)))
 552                 return -ENXIO;
 553         if (unlikely(need_wait))
 554                 return -EOPNOTSUPP;
 555
 556         if (sk_can_busy_loop(sk))
 557                 sk_busy_loop(sk, 1); /* only support non-blocking sockets */
 558
 559         if (xsk_no_wakeup(sk))
 560                 return 0;
 561
 562         pool = xs->pool;
 563         if (pool->cached_need_wakeup & XDP_WAKEUP_TX)
 564                 return __xsk_sendmsg(sk);
 565         return 0;
 566 }
 567
 568 static int xsk_recvmsg(struct socket *sock, struct msghdr *m, size_t len, int flags)
 569 {
 570         bool need_wait = !(flags & MSG_DONTWAIT);
 571         struct sock *sk = sock->sk;
 572         struct xdp_sock *xs = xdp_sk(sk);
 573
 574         if (unlikely(!xsk_is_bound(xs)))
 575                 return -ENXIO;
 576         if (unlikely(!(xs->dev->flags & IFF_UP)))
 577                 return -ENETDOWN;
 578         if (unlikely(!xs->rx))
 579                 return -ENOBUFS;
 580         if (unlikely(need_wait))
 581                 return -EOPNOTSUPP;
 582
 583         if (sk_can_busy_loop(sk))
 584                 sk_busy_loop(sk, 1); /* only support non-blocking sockets */
 585
 586         if (xsk_no_wakeup(sk))
 587                 return 0;
 588
 589         if (xs->pool->cached_need_wakeup & XDP_WAKEUP_RX && xs->zc)
 590                 return xsk_wakeup(xs, XDP_WAKEUP_RX);
 591         return 0;
 592 }
 593
 594 static __poll_t xsk_poll(struct file *file, struct socket *sock,
 595                              struct poll_table_struct *wait)
 596 {
 597         __poll_t mask = 0;
 598         struct sock *sk = sock->sk;
 599         struct xdp_sock *xs = xdp_sk(sk);
 600         struct xsk_buff_pool *pool;
 601
 602         sock_poll_wait(file, sock, wait);
 603
 604         if (unlikely(!xsk_is_bound(xs)))
 605                 return mask;
 606
 607         pool = xs->pool;
 608
 609         if (pool->cached_need_wakeup) {
 610                 if (xs->zc)
 611                         xsk_wakeup(xs, pool->cached_need_wakeup);
 612                 else
 613                         /* Poll needs to drive Tx also in copy mode */
 614                         __xsk_sendmsg(sk);
 615         }
 616
 617         if (xs->rx && !xskq_prod_is_empty(xs->rx))
 618                 mask |= EPOLLIN | EPOLLRDNORM;
 619         if (xs->tx && xsk_tx_writeable(xs))
 620                 mask |= EPOLLOUT | EPOLLWRNORM;
 621
 622         return mask;
 623 }
 624
 625 static int xsk_init_queue(u32 entries, struct xsk_queue **queue,
 626                           bool umem_queue)
 627 {
 628         struct xsk_queue *q;
 629
 630         if (entries == 0 || *queue || !is_power_of_2(entries))
 631                 return -EINVAL;
 632
 633         q = xskq_create(entries, umem_queue);
 634         if (!q)
 635                 return -ENOMEM;
 636
 637         /* Make sure queue is ready before it can be seen by others */
 638         smp_wmb();
 639         WRITE_ONCE(*queue, q);
 640         return 0;
 641 }
 642
 643 static void xsk_unbind_dev(struct xdp_sock *xs)
 644 {
 645         struct net_device *dev = xs->dev;
 646
 647         if (xs->state != XSK_BOUND)
 648                 return;
 649         WRITE_ONCE(xs->state, XSK_UNBOUND);
 650
 651         /* Wait for driver to stop using the xdp socket. */
 652         xp_del_xsk(xs->pool, xs);
 653         xs->dev = NULL;
 654         synchronize_net();
 655         dev_put(dev);
 656 }
 657
 658 static struct xsk_map *xsk_get_map_list_entry(struct xdp_sock *xs,
 659                                               struct xdp_sock ***map_entry)
 660 {
 661         struct xsk_map *map = NULL;
 662         struct xsk_map_node *node;
 663
 664         *map_entry = NULL;
 665
 666         spin_lock_bh(&xs->map_list_lock);
 667         node = list_first_entry_or_null(&xs->map_list, struct xsk_map_node,
 668                                         node);
 669         if (node) {
 670                 bpf_map_inc(&node->map->map);
 671                 map = node->map;
 672                 *map_entry = node->map_entry;
 673         }
 674         spin_unlock_bh(&xs->map_list_lock);
 675         return map;
 676 }
 677
 678 static void xsk_delete_from_maps(struct xdp_sock *xs)
 679 {
 680         /* This function removes the current XDP socket from all the
 681          * maps it resides in. We need to take extra care here, due to
 682          * the two locks involved. Each map has a lock synchronizing
 683          * updates to the entries, and each socket has a lock that
 684          * synchronizes access to the list of maps (map_list). For
 685          * deadlock avoidance the locks need to be taken in the order
 686          * "map lock"->"socket map list lock". We start off by
 687          * accessing the socket map list, and take a reference to the
 688          * map to guarantee existence between the
 689          * xsk_get_map_list_entry() and xsk_map_try_sock_delete()
 690          * calls. Then we ask the map to remove the socket, which
 691          * tries to remove the socket from the map. Note that there
 692          * might be updates to the map between
 693          * xsk_get_map_list_entry() and xsk_map_try_sock_delete().
 694          */
 695         struct xdp_sock **map_entry = NULL;
 696         struct xsk_map *map;
 697
 698         while ((map = xsk_get_map_list_entry(xs, &map_entry))) {
 699                 xsk_map_try_sock_delete(map, xs, map_entry);
 700                 bpf_map_put(&map->map);
 701         }
 702 }
 703
 704 static int xsk_release(struct socket *sock)
 705 {
 706         struct sock *sk = sock->sk;
 707         struct xdp_sock *xs = xdp_sk(sk);
 708         struct net *net;
 709
 710         if (!sk)
 711                 return 0;
 712
 713         net = sock_net(sk);
 714
 715         mutex_lock(&net->xdp.lock);
 716         sk_del_node_init_rcu(sk);
 717         mutex_unlock(&net->xdp.lock);
 718
 719         local_bh_disable();
 720         sock_prot_inuse_add(net, sk->sk_prot, -1);
 721         local_bh_enable();
 722
 723         xsk_delete_from_maps(xs);
 724         mutex_lock(&xs->mutex);
 725         xsk_unbind_dev(xs);
 726         mutex_unlock(&xs->mutex);
 727
 728         xskq_destroy(xs->rx);
 729         xskq_destroy(xs->tx);
 730         xskq_destroy(xs->fq_tmp);
 731         xskq_destroy(xs->cq_tmp);
 732
 733         sock_orphan(sk);
 734         sock->sk = NULL;
 735
 736         sk_refcnt_debug_release(sk);
 737         sock_put(sk);
 738
 739         return 0;
 740 }
 741
 742 static struct socket *xsk_lookup_xsk_from_fd(int fd)
 743 {
 744         struct socket *sock;
 745         int err;
 746
 747         sock = sockfd_lookup(fd, &err);
 748         if (!sock)
 749                 return ERR_PTR(-ENOTSOCK);
 750
 751         if (sock->sk->sk_family != PF_XDP) {
 752                 sockfd_put(sock);
 753                 return ERR_PTR(-ENOPROTOOPT);
 754         }
 755
 756         return sock;
 757 }
 758
 759 static bool xsk_validate_queues(struct xdp_sock *xs)
 760 {
 761         return xs->fq_tmp && xs->cq_tmp;
 762 }
 763
 764 static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
 765 {
 766         struct sockaddr_xdp *sxdp = (struct sockaddr_xdp *)addr;
 767         struct sock *sk = sock->sk;
 768         struct xdp_sock *xs = xdp_sk(sk);
 769         struct net_device *dev;
 770         u32 flags, qid;
 771         int err = 0;
 772
 773         if (addr_len < sizeof(struct sockaddr_xdp))
 774                 return -EINVAL;
 775         if (sxdp->sxdp_family != AF_XDP)
 776                 return -EINVAL;
 777
 778         flags = sxdp->sxdp_flags;
 779         if (flags & ~(XDP_SHARED_UMEM | XDP_COPY | XDP_ZEROCOPY |
 780                       XDP_USE_NEED_WAKEUP))
 781                 return -EINVAL;
 782
 783         rtnl_lock();
 784         mutex_lock(&xs->mutex);
 785         if (xs->state != XSK_READY) {
 786                 err = -EBUSY;
 787                 goto out_release;
 788         }
 789
 790         dev = dev_get_by_index(sock_net(sk), sxdp->sxdp_ifindex);
 791         if (!dev) {
 792                 err = -ENODEV;
 793                 goto out_release;
 794         }
 795
 796         if (!xs->rx && !xs->tx) {
 797                 err = -EINVAL;
 798                 goto out_unlock;
 799         }
 800
 801         qid = sxdp->sxdp_queue_id;
 802
 803         if (flags & XDP_SHARED_UMEM) {
 804                 struct xdp_sock *umem_xs;
 805                 struct socket *sock;
 806
 807                 if ((flags & XDP_COPY) || (flags & XDP_ZEROCOPY) ||
 808                     (flags & XDP_USE_NEED_WAKEUP)) {
 809                         /* Cannot specify flags for shared sockets. */
 810                         err = -EINVAL;
 811                         goto out_unlock;
 812                 }
 813
 814                 if (xs->umem) {
 815                         /* We have already our own. */
 816                         err = -EINVAL;
 817                         goto out_unlock;
 818                 }
 819
 820                 sock = xsk_lookup_xsk_from_fd(sxdp->sxdp_shared_umem_fd);
 821                 if (IS_ERR(sock)) {
 822                         err = PTR_ERR(sock);
 823                         goto out_unlock;
 824                 }
 825
 826                 umem_xs = xdp_sk(sock->sk);
 827                 if (!xsk_is_bound(umem_xs)) {
 828                         err = -EBADF;
 829                         sockfd_put(sock);
 830                         goto out_unlock;
 831                 }
 832
 833                 if (umem_xs->queue_id != qid || umem_xs->dev != dev) {
 834                         /* Share the umem with another socket on another qid
 835                          * and/or device.
 836                          */
 837                         xs->pool = xp_create_and_assign_umem(xs,
 838                                                              umem_xs->umem);
 839                         if (!xs->pool) {
 840                                 err = -ENOMEM;
 841                                 sockfd_put(sock);
 842                                 goto out_unlock;
 843                         }
 844
 845                         err = xp_assign_dev_shared(xs->pool, umem_xs->umem,
 846                                                    dev, qid);
 847                         if (err) {
 848                                 xp_destroy(xs->pool);
 849                                 xs->pool = NULL;
 850                                 sockfd_put(sock);
 851                                 goto out_unlock;
 852                         }
 853                 } else {
 854                         /* Share the buffer pool with the other socket. */
 855                         if (xs->fq_tmp || xs->cq_tmp) {
 856                                 /* Do not allow setting your own fq or cq. */
 857                                 err = -EINVAL;
 858                                 sockfd_put(sock);
 859                                 goto out_unlock;
 860                         }
 861
 862                         xp_get_pool(umem_xs->pool);
 863                         xs->pool = umem_xs->pool;
 864                 }
 865
 866                 xdp_get_umem(umem_xs->umem);
 867                 WRITE_ONCE(xs->umem, umem_xs->umem);
 868                 sockfd_put(sock);
 869         } else if (!xs->umem || !xsk_validate_queues(xs)) {
 870                 err = -EINVAL;
 871                 goto out_unlock;
 872         } else {
 873                 /* This xsk has its own umem. */
 874                 xs->pool = xp_create_and_assign_umem(xs, xs->umem);
 875                 if (!xs->pool) {
 876                         err = -ENOMEM;
 877                         goto out_unlock;
 878                 }
 879
 880                 err = xp_assign_dev(xs->pool, dev, qid, flags);
 881                 if (err) {
 882                         xp_destroy(xs->pool);
 883                         xs->pool = NULL;
 884                         goto out_unlock;
 885                 }
 886         }
 887
 888         /* FQ and CQ are now owned by the buffer pool and cleaned up with it. */
 889         xs->fq_tmp = NULL;
 890         xs->cq_tmp = NULL;
 891
 892         xs->dev = dev;
 893         xs->zc = xs->umem->zc;
 894         xs->queue_id = qid;
 895         xp_add_xsk(xs->pool, xs);
 896
 897 out_unlock:
 898         if (err) {
 899                 dev_put(dev);
 900         } else {
 901                 /* Matches smp_rmb() in bind() for shared umem
 902                  * sockets, and xsk_is_bound().
 903                  */
 904                 smp_wmb();
 905                 WRITE_ONCE(xs->state, XSK_BOUND);
 906         }
 907 out_release:
 908         mutex_unlock(&xs->mutex);
 909         rtnl_unlock();
 910         return err;
 911 }
 912
 913 struct xdp_umem_reg_v1 {
 914         __u64 addr; /* Start of packet data area */
 915         __u64 len; /* Length of packet data area */
 916         __u32 chunk_size;
 917         __u32 headroom;
 918 };
 919
 920 static int xsk_setsockopt(struct socket *sock, int level, int optname,
 921                           sockptr_t optval, unsigned int optlen)
 922 {
 923         struct sock *sk = sock->sk;
 924         struct xdp_sock *xs = xdp_sk(sk);
 925         int err;
 926
 927         if (level != SOL_XDP)
 928                 return -ENOPROTOOPT;
 929
 930         switch (optname) {
 931         case XDP_RX_RING:
 932         case XDP_TX_RING:
 933         {
 934                 struct xsk_queue **q;
 935                 int entries;
 936
 937                 if (optlen < sizeof(entries))
 938                         return -EINVAL;
 939                 if (copy_from_sockptr(&entries, optval, sizeof(entries)))
 940                         return -EFAULT;
 941
 942                 mutex_lock(&xs->mutex);
 943                 if (xs->state != XSK_READY) {
 944                         mutex_unlock(&xs->mutex);
 945                         return -EBUSY;
 946                 }
 947                 q = (optname == XDP_TX_RING) ? &xs->tx : &xs->rx;
 948                 err = xsk_init_queue(entries, q, false);
 949                 if (!err && optname == XDP_TX_RING)
 950                         /* Tx needs to be explicitly woken up the first time */
 951                         xs->tx->ring->flags |= XDP_RING_NEED_WAKEUP;
 952                 mutex_unlock(&xs->mutex);
 953                 return err;
 954         }
 955         case XDP_UMEM_REG:
 956         {
 957                 size_t mr_size = sizeof(struct xdp_umem_reg);
 958                 struct xdp_umem_reg mr = {};
 959                 struct xdp_umem *umem;
 960
 961                 if (optlen < sizeof(struct xdp_umem_reg_v1))
 962                         return -EINVAL;
 963                 else if (optlen < sizeof(mr))
 964                         mr_size = sizeof(struct xdp_umem_reg_v1);
 965
 966                 if (copy_from_sockptr(&mr, optval, mr_size))
 967                         return -EFAULT;
 968
 969                 mutex_lock(&xs->mutex);
 970                 if (xs->state != XSK_READY || xs->umem) {
 971                         mutex_unlock(&xs->mutex);
 972                         return -EBUSY;
 973                 }
 974
 975                 umem = xdp_umem_create(&mr);
 976                 if (IS_ERR(umem)) {
 977                         mutex_unlock(&xs->mutex);
 978                         return PTR_ERR(umem);
 979                 }
 980
 981                 /* Make sure umem is ready before it can be seen by others */
 982                 smp_wmb();
 983                 WRITE_ONCE(xs->umem, umem);
 984                 mutex_unlock(&xs->mutex);
 985                 return 0;
 986         }
 987         case XDP_UMEM_FILL_RING:
 988         case XDP_UMEM_COMPLETION_RING:
 989         {
 990                 struct xsk_queue **q;
 991                 int entries;
 992
 993                 if (copy_from_sockptr(&entries, optval, sizeof(entries)))
 994                         return -EFAULT;
 995
 996                 mutex_lock(&xs->mutex);
 997                 if (xs->state != XSK_READY) {
 998                         mutex_unlock(&xs->mutex);
 999                         return -EBUSY;
1000                 }
1001
1002                 q = (optname == XDP_UMEM_FILL_RING) ? &xs->fq_tmp :
1003                         &xs->cq_tmp;
1004                 err = xsk_init_queue(entries, q, true);
1005                 mutex_unlock(&xs->mutex);
1006                 return err;
1007         }
1008         default:
1009                 break;
1010         }
1011
1012         return -ENOPROTOOPT;
1013 }
1014
1015 static void xsk_enter_rxtx_offsets(struct xdp_ring_offset_v1 *ring)
1016 {
1017         ring->producer = offsetof(struct xdp_rxtx_ring, ptrs.producer);
1018         ring->consumer = offsetof(struct xdp_rxtx_ring, ptrs.consumer);
1019         ring->desc = offsetof(struct xdp_rxtx_ring, desc);
1020 }
1021
1022 static void xsk_enter_umem_offsets(struct xdp_ring_offset_v1 *ring)
1023 {
1024         ring->producer = offsetof(struct xdp_umem_ring, ptrs.producer);
1025         ring->consumer = offsetof(struct xdp_umem_ring, ptrs.consumer);
1026         ring->desc = offsetof(struct xdp_umem_ring, desc);
1027 }
1028
1029 struct xdp_statistics_v1 {
1030         __u64 rx_dropped;
1031         __u64 rx_invalid_descs;
1032         __u64 tx_invalid_descs;
1033 };
1034
1035 static int xsk_getsockopt(struct socket *sock, int level, int optname,
1036                           char __user *optval, int __user *optlen)
1037 {
1038         struct sock *sk = sock->sk;
1039         struct xdp_sock *xs = xdp_sk(sk);
1040         int len;
1041
1042         if (level != SOL_XDP)
1043                 return -ENOPROTOOPT;
1044
1045         if (get_user(len, optlen))
1046                 return -EFAULT;
1047         if (len < 0)
1048                 return -EINVAL;
1049
1050         switch (optname) {
1051         case XDP_STATISTICS:
1052         {
1053                 struct xdp_statistics stats = {};
1054                 bool extra_stats = true;
1055                 size_t stats_size;
1056
1057                 if (len < sizeof(struct xdp_statistics_v1)) {
1058                         return -EINVAL;
1059                 } else if (len < sizeof(stats)) {
1060                         extra_stats = false;
1061                         stats_size = sizeof(struct xdp_statistics_v1);
1062                 } else {
1063                         stats_size = sizeof(stats);
1064                 }
1065
1066                 mutex_lock(&xs->mutex);
1067                 stats.rx_dropped = xs->rx_dropped;
1068                 if (extra_stats) {
1069                         stats.rx_ring_full = xs->rx_queue_full;
1070                         stats.rx_fill_ring_empty_descs =
1071                                 xs->pool ? xskq_nb_queue_empty_descs(xs->pool->fq) : 0;
1072                         stats.tx_ring_empty_descs = xskq_nb_queue_empty_descs(xs->tx);
1073                 } else {
1074                         stats.rx_dropped += xs->rx_queue_full;
1075                 }
1076                 stats.rx_invalid_descs = xskq_nb_invalid_descs(xs->rx);
1077                 stats.tx_invalid_descs = xskq_nb_invalid_descs(xs->tx);
1078                 mutex_unlock(&xs->mutex);
1079
1080                 if (copy_to_user(optval, &stats, stats_size))
1081                         return -EFAULT;
1082                 if (put_user(stats_size, optlen))
1083                         return -EFAULT;
1084
1085                 return 0;
1086         }
1087         case XDP_MMAP_OFFSETS:
1088         {
1089                 struct xdp_mmap_offsets off;
1090                 struct xdp_mmap_offsets_v1 off_v1;
1091                 bool flags_supported = true;
1092                 void *to_copy;
1093
1094                 if (len < sizeof(off_v1))
1095                         return -EINVAL;
1096                 else if (len < sizeof(off))
1097                         flags_supported = false;
1098
1099                 if (flags_supported) {
1100                         /* xdp_ring_offset is identical to xdp_ring_offset_v1
1101                          * except for the flags field added to the end.
1102                          */
1103                         xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *)
1104                                                &off.rx);
1105                         xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *)
1106                                                &off.tx);
1107                         xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *)
1108                                                &off.fr);
1109                         xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *)
1110                                                &off.cr);
1111                         off.rx.flags = offsetof(struct xdp_rxtx_ring,
1112                                                 ptrs.flags);
1113                         off.tx.flags = offsetof(struct xdp_rxtx_ring,
1114                                                 ptrs.flags);
1115                         off.fr.flags = offsetof(struct xdp_umem_ring,
1116                                                 ptrs.flags);
1117                         off.cr.flags = offsetof(struct xdp_umem_ring,
1118                                                 ptrs.flags);
1119
1120                         len = sizeof(off);
1121                         to_copy = &off;
1122                 } else {
1123                         xsk_enter_rxtx_offsets(&off_v1.rx);
1124                         xsk_enter_rxtx_offsets(&off_v1.tx);
1125                         xsk_enter_umem_offsets(&off_v1.fr);
1126                         xsk_enter_umem_offsets(&off_v1.cr);
1127
1128                         len = sizeof(off_v1);
1129                         to_copy = &off_v1;
1130                 }
1131
1132                 if (copy_to_user(optval, to_copy, len))
1133                         return -EFAULT;
1134                 if (put_user(len, optlen))
1135                         return -EFAULT;
1136
1137                 return 0;
1138         }
1139         case XDP_OPTIONS:
1140         {
1141                 struct xdp_options opts = {};
1142
1143                 if (len < sizeof(opts))
1144                         return -EINVAL;
1145
1146                 mutex_lock(&xs->mutex);
1147                 if (xs->zc)
1148                         opts.flags |= XDP_OPTIONS_ZEROCOPY;
1149                 mutex_unlock(&xs->mutex);
1150
1151                 len = sizeof(opts);
1152                 if (copy_to_user(optval, &opts, len))
1153                         return -EFAULT;
1154                 if (put_user(len, optlen))
1155                         return -EFAULT;
1156
1157                 return 0;
1158         }
1159         default:
1160                 break;
1161         }
1162
1163         return -EOPNOTSUPP;
1164 }
1165
1166 static int xsk_mmap(struct file *file, struct socket *sock,
1167                     struct vm_area_struct *vma)
1168 {
1169         loff_t offset = (loff_t)vma->vm_pgoff << PAGE_SHIFT;
1170         unsigned long size = vma->vm_end - vma->vm_start;
1171         struct xdp_sock *xs = xdp_sk(sock->sk);
1172         struct xsk_queue *q = NULL;
1173         unsigned long pfn;
1174         struct page *qpg;
1175
1176         if (READ_ONCE(xs->state) != XSK_READY)
1177                 return -EBUSY;
1178
1179         if (offset == XDP_PGOFF_RX_RING) {
1180                 q = READ_ONCE(xs->rx);
1181         } else if (offset == XDP_PGOFF_TX_RING) {
1182                 q = READ_ONCE(xs->tx);
1183         } else {
1184                 /* Matches the smp_wmb() in XDP_UMEM_REG */
1185                 smp_rmb();
1186                 if (offset == XDP_UMEM_PGOFF_FILL_RING)
1187                         q = READ_ONCE(xs->fq_tmp);
1188                 else if (offset == XDP_UMEM_PGOFF_COMPLETION_RING)
1189                         q = READ_ONCE(xs->cq_tmp);
1190         }
1191
1192         if (!q)
1193                 return -EINVAL;
1194
1195         /* Matches the smp_wmb() in xsk_init_queue */
1196         smp_rmb();
1197         qpg = virt_to_head_page(q->ring);
1198         if (size > page_size(qpg))
1199                 return -EINVAL;
1200
1201         pfn = virt_to_phys(q->ring) >> PAGE_SHIFT;
1202         return remap_pfn_range(vma, vma->vm_start, pfn,
1203                                size, vma->vm_page_prot);
1204 }
1205
1206 static int xsk_notifier(struct notifier_block *this,
1207                         unsigned long msg, void *ptr)
1208 {
1209         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1210         struct net *net = dev_net(dev);
1211         struct sock *sk;
1212
1213         switch (msg) {
1214         case NETDEV_UNREGISTER:
1215                 mutex_lock(&net->xdp.lock);
1216                 sk_for_each(sk, &net->xdp.list) {
1217                         struct xdp_sock *xs = xdp_sk(sk);
1218
1219                         mutex_lock(&xs->mutex);
1220                         if (xs->dev == dev) {
1221                                 sk->sk_err = ENETDOWN;
1222                                 if (!sock_flag(sk, SOCK_DEAD))
1223                                         sk->sk_error_report(sk);
1224
1225                                 xsk_unbind_dev(xs);
1226
1227                                 /* Clear device references. */
1228                                 xp_clear_dev(xs->pool);
1229                         }
1230                         mutex_unlock(&xs->mutex);
1231                 }
1232                 mutex_unlock(&net->xdp.lock);
1233                 break;
1234         }
1235         return NOTIFY_DONE;
1236 }
1237
1238 static struct proto xsk_proto = {
1239         .name =         "XDP",
1240         .owner =        THIS_MODULE,
1241         .obj_size =     sizeof(struct xdp_sock),
1242 };
1243
1244 static const struct proto_ops xsk_proto_ops = {
1245         .family         = PF_XDP,
1246         .owner          = THIS_MODULE,
1247         .release        = xsk_release,
1248         .bind           = xsk_bind,
1249         .connect        = sock_no_connect,
1250         .socketpair     = sock_no_socketpair,
1251         .accept         = sock_no_accept,
1252         .getname        = sock_no_getname,
1253         .poll           = xsk_poll,
1254         .ioctl          = sock_no_ioctl,
1255         .listen         = sock_no_listen,
1256         .shutdown       = sock_no_shutdown,
1257         .setsockopt     = xsk_setsockopt,
1258         .getsockopt     = xsk_getsockopt,
1259         .sendmsg        = xsk_sendmsg,
1260         .recvmsg        = xsk_recvmsg,
1261         .mmap           = xsk_mmap,
1262         .sendpage       = sock_no_sendpage,
1263 };
1264
1265 static void xsk_destruct(struct sock *sk)
1266 {
1267         struct xdp_sock *xs = xdp_sk(sk);
1268
1269         if (!sock_flag(sk, SOCK_DEAD))
1270                 return;
1271
1272         if (!xp_put_pool(xs->pool))
1273                 xdp_put_umem(xs->umem, !xs->pool);
1274
1275         sk_refcnt_debug_dec(sk);
1276 }
1277
1278 static int xsk_create(struct net *net, struct socket *sock, int protocol,
1279                       int kern)
1280 {
1281         struct xdp_sock *xs;
1282         struct sock *sk;
1283
1284         if (!ns_capable(net->user_ns, CAP_NET_RAW))
1285                 return -EPERM;
1286         if (sock->type != SOCK_RAW)
1287                 return -ESOCKTNOSUPPORT;
1288
1289         if (protocol)
1290                 return -EPROTONOSUPPORT;
1291
1292         sock->state = SS_UNCONNECTED;
1293
1294         sk = sk_alloc(net, PF_XDP, GFP_KERNEL, &xsk_proto, kern);
1295         if (!sk)
1296                 return -ENOBUFS;
1297
1298         sock->ops = &xsk_proto_ops;
1299
1300         sock_init_data(sock, sk);
1301
1302         sk->sk_family = PF_XDP;
1303
1304         sk->sk_destruct = xsk_destruct;
1305         sk_refcnt_debug_inc(sk);
1306
1307         sock_set_flag(sk, SOCK_RCU_FREE);
1308
1309         xs = xdp_sk(sk);
1310         xs->state = XSK_READY;
1311         mutex_init(&xs->mutex);
1312         spin_lock_init(&xs->rx_lock);
1313
1314         INIT_LIST_HEAD(&xs->map_list);
1315         spin_lock_init(&xs->map_list_lock);
1316
1317         mutex_lock(&net->xdp.lock);
1318         sk_add_node_rcu(sk, &net->xdp.list);
1319         mutex_unlock(&net->xdp.lock);
1320
1321         local_bh_disable();
1322         sock_prot_inuse_add(net, &xsk_proto, 1);
1323         local_bh_enable();
1324
1325         return 0;
1326 }
1327
1328 static const struct net_proto_family xsk_family_ops = {
1329         .family = PF_XDP,
1330         .create = xsk_create,
1331         .owner  = THIS_MODULE,
1332 };
1333
1334 static struct notifier_block xsk_netdev_notifier = {
1335         .notifier_call  = xsk_notifier,
1336 };
1337
1338 static int __net_init xsk_net_init(struct net *net)
1339 {
1340         mutex_init(&net->xdp.lock);
1341         INIT_HLIST_HEAD(&net->xdp.list);
1342         return 0;
1343 }
1344
1345 static void __net_exit xsk_net_exit(struct net *net)
1346 {
1347         WARN_ON_ONCE(!hlist_empty(&net->xdp.list));
1348 }
1349
1350 static struct pernet_operations xsk_net_ops = {
1351         .init = xsk_net_init,
1352         .exit = xsk_net_exit,
1353 };
1354
1355 static int __init xsk_init(void)
1356 {
1357         int err, cpu;
1358
1359         err = proto_register(&xsk_proto, 0 /* no slab */);
1360         if (err)
1361                 goto out;
1362
1363         err = sock_register(&xsk_family_ops);
1364         if (err)
1365                 goto out_proto;
1366
1367         err = register_pernet_subsys(&xsk_net_ops);
1368         if (err)
1369                 goto out_sk;
1370
1371         err = register_netdevice_notifier(&xsk_netdev_notifier);
1372         if (err)
1373                 goto out_pernet;
1374
1375         for_each_possible_cpu(cpu)
1376                 INIT_LIST_HEAD(&per_cpu(xskmap_flush_list, cpu));
1377         return 0;
1378
1379 out_pernet:
1380         unregister_pernet_subsys(&xsk_net_ops);
1381 out_sk:
1382         sock_unregister(PF_XDP);
1383 out_proto:
1384         proto_unregister(&xsk_proto);
1385 out:
1386         return err;
1387 }
1388
1389 fs_initcall(xsk_init);