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 <linux/vmalloc.h>
  26 #include <net/xdp_sock_drv.h>
  27 #include <net/busy_poll.h>
  28 #include <net/xdp.h>
  29
  30 #include "xsk_queue.h"
  31 #include "xdp_umem.h"
  32 #include "xsk.h"
  33
  34 #define TX_BATCH_SIZE 32
  35
  36 static DEFINE_PER_CPU(struct list_head, xskmap_flush_list);
  37
  38 void xsk_set_rx_need_wakeup(struct xsk_buff_pool *pool)
  39 {
  40         if (pool->cached_need_wakeup & XDP_WAKEUP_RX)
  41                 return;
  42
  43         pool->fq->ring->flags |= XDP_RING_NEED_WAKEUP;
  44         pool->cached_need_wakeup |= XDP_WAKEUP_RX;
  45 }
  46 EXPORT_SYMBOL(xsk_set_rx_need_wakeup);
  47
  48 void xsk_set_tx_need_wakeup(struct xsk_buff_pool *pool)
  49 {
  50         struct xdp_sock *xs;
  51
  52         if (pool->cached_need_wakeup & XDP_WAKEUP_TX)
  53                 return;
  54
  55         rcu_read_lock();
  56         list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) {
  57                 xs->tx->ring->flags |= XDP_RING_NEED_WAKEUP;
  58         }
  59         rcu_read_unlock();
  60
  61         pool->cached_need_wakeup |= XDP_WAKEUP_TX;
  62 }
  63 EXPORT_SYMBOL(xsk_set_tx_need_wakeup);
  64
  65 void xsk_clear_rx_need_wakeup(struct xsk_buff_pool *pool)
  66 {
  67         if (!(pool->cached_need_wakeup & XDP_WAKEUP_RX))
  68                 return;
  69
  70         pool->fq->ring->flags &= ~XDP_RING_NEED_WAKEUP;
  71         pool->cached_need_wakeup &= ~XDP_WAKEUP_RX;
  72 }
  73 EXPORT_SYMBOL(xsk_clear_rx_need_wakeup);
  74
  75 void xsk_clear_tx_need_wakeup(struct xsk_buff_pool *pool)
  76 {
  77         struct xdp_sock *xs;
  78
  79         if (!(pool->cached_need_wakeup & XDP_WAKEUP_TX))
  80                 return;
  81
  82         rcu_read_lock();
  83         list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) {
  84                 xs->tx->ring->flags &= ~XDP_RING_NEED_WAKEUP;
  85         }
  86         rcu_read_unlock();
  87
  88         pool->cached_need_wakeup &= ~XDP_WAKEUP_TX;
  89 }
  90 EXPORT_SYMBOL(xsk_clear_tx_need_wakeup);
  91
  92 bool xsk_uses_need_wakeup(struct xsk_buff_pool *pool)
  93 {
  94         return pool->uses_need_wakeup;
  95 }
  96 EXPORT_SYMBOL(xsk_uses_need_wakeup);
  97
  98 struct xsk_buff_pool *xsk_get_pool_from_qid(struct net_device *dev,
  99                                             u16 queue_id)
 100 {
 101         if (queue_id < dev->real_num_rx_queues)
 102                 return dev->_rx[queue_id].pool;
 103         if (queue_id < dev->real_num_tx_queues)
 104                 return dev->_tx[queue_id].pool;
 105
 106         return NULL;
 107 }
 108 EXPORT_SYMBOL(xsk_get_pool_from_qid);
 109
 110 void xsk_clear_pool_at_qid(struct net_device *dev, u16 queue_id)
 111 {
 112         if (queue_id < dev->num_rx_queues)
 113                 dev->_rx[queue_id].pool = NULL;
 114         if (queue_id < dev->num_tx_queues)
 115                 dev->_tx[queue_id].pool = NULL;
 116 }
 117
 118 /* The buffer pool is stored both in the _rx struct and the _tx struct as we do
 119  * not know if the device has more tx queues than rx, or the opposite.
 120  * This might also change during run time.
 121  */
 122 int xsk_reg_pool_at_qid(struct net_device *dev, struct xsk_buff_pool *pool,
 123                         u16 queue_id)
 124 {
 125         if (queue_id >= max_t(unsigned int,
 126                               dev->real_num_rx_queues,
 127                               dev->real_num_tx_queues))
 128                 return -EINVAL;
 129
 130         if (queue_id < dev->real_num_rx_queues)
 131                 dev->_rx[queue_id].pool = pool;
 132         if (queue_id < dev->real_num_tx_queues)
 133                 dev->_tx[queue_id].pool = pool;
 134
 135         return 0;
 136 }
 137
 138 static int __xsk_rcv_zc(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len)
 139 {
 140         struct xdp_buff_xsk *xskb = container_of(xdp, struct xdp_buff_xsk, xdp);
 141         u64 addr;
 142         int err;
 143
 144         addr = xp_get_handle(xskb);
 145         err = xskq_prod_reserve_desc(xs->rx, addr, len);
 146         if (err) {
 147                 xs->rx_queue_full++;
 148                 return err;
 149         }
 150
 151         xp_release(xskb);
 152         return 0;
 153 }
 154
 155 static void xsk_copy_xdp(struct xdp_buff *to, struct xdp_buff *from, u32 len)
 156 {
 157         void *from_buf, *to_buf;
 158         u32 metalen;
 159
 160         if (unlikely(xdp_data_meta_unsupported(from))) {
 161                 from_buf = from->data;
 162                 to_buf = to->data;
 163                 metalen = 0;
 164         } else {
 165                 from_buf = from->data_meta;
 166                 metalen = from->data - from->data_meta;
 167                 to_buf = to->data - metalen;
 168         }
 169
 170         memcpy(to_buf, from_buf, len + metalen);
 171 }
 172
 173 static int __xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
 174 {
 175         struct xdp_buff *xsk_xdp;
 176         int err;
 177         u32 len;
 178
 179         len = xdp->data_end - xdp->data;
 180         if (len > xsk_pool_get_rx_frame_size(xs->pool)) {
 181                 xs->rx_dropped++;
 182                 return -ENOSPC;
 183         }
 184
 185         xsk_xdp = xsk_buff_alloc(xs->pool);
 186         if (!xsk_xdp) {
 187                 xs->rx_dropped++;
 188                 return -ENOMEM;
 189         }
 190
 191         xsk_copy_xdp(xsk_xdp, xdp, len);
 192         err = __xsk_rcv_zc(xs, xsk_xdp, len);
 193         if (err) {
 194                 xsk_buff_free(xsk_xdp);
 195                 return err;
 196         }
 197         return 0;
 198 }
 199
 200 static bool xsk_tx_writeable(struct xdp_sock *xs)
 201 {
 202         if (xskq_cons_present_entries(xs->tx) > xs->tx->nentries / 2)
 203                 return false;
 204
 205         return true;
 206 }
 207
 208 static bool xsk_is_bound(struct xdp_sock *xs)
 209 {
 210         if (READ_ONCE(xs->state) == XSK_BOUND) {
 211                 /* Matches smp_wmb() in bind(). */
 212                 smp_rmb();
 213                 return true;
 214         }
 215         return false;
 216 }
 217
 218 static int xsk_rcv_check(struct xdp_sock *xs, struct xdp_buff *xdp)
 219 {
 220         if (!xsk_is_bound(xs))
 221                 return -ENXIO;
 222
 223         if (xs->dev != xdp->rxq->dev || xs->queue_id != xdp->rxq->queue_index)
 224                 return -EINVAL;
 225
 226         sk_mark_napi_id_once_xdp(&xs->sk, xdp);
 227         return 0;
 228 }
 229
 230 static void xsk_flush(struct xdp_sock *xs)
 231 {
 232         xskq_prod_submit(xs->rx);
 233         __xskq_cons_release(xs->pool->fq);
 234         sock_def_readable(&xs->sk);
 235 }
 236
 237 int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
 238 {
 239         int err;
 240
 241         spin_lock_bh(&xs->rx_lock);
 242         err = xsk_rcv_check(xs, xdp);
 243         if (!err) {
 244                 err = __xsk_rcv(xs, xdp);
 245                 xsk_flush(xs);
 246         }
 247         spin_unlock_bh(&xs->rx_lock);
 248         return err;
 249 }
 250
 251 static int xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
 252 {
 253         int err;
 254         u32 len;
 255
 256         err = xsk_rcv_check(xs, xdp);
 257         if (err)
 258                 return err;
 259
 260         if (xdp->rxq->mem.type == MEM_TYPE_XSK_BUFF_POOL) {
 261                 len = xdp->data_end - xdp->data;
 262                 return __xsk_rcv_zc(xs, xdp, len);
 263         }
 264
 265         err = __xsk_rcv(xs, xdp);
 266         if (!err)
 267                 xdp_return_buff(xdp);
 268         return err;
 269 }
 270
 271 int __xsk_map_redirect(struct xdp_sock *xs, struct xdp_buff *xdp)
 272 {
 273         struct list_head *flush_list = this_cpu_ptr(&xskmap_flush_list);
 274         int err;
 275
 276         err = xsk_rcv(xs, xdp);
 277         if (err)
 278                 return err;
 279
 280         if (!xs->flush_node.prev)
 281                 list_add(&xs->flush_node, flush_list);
 282
 283         return 0;
 284 }
 285
 286 void __xsk_map_flush(void)
 287 {
 288         struct list_head *flush_list = this_cpu_ptr(&xskmap_flush_list);
 289         struct xdp_sock *xs, *tmp;
 290
 291         list_for_each_entry_safe(xs, tmp, flush_list, flush_node) {
 292                 xsk_flush(xs);
 293                 __list_del_clearprev(&xs->flush_node);
 294         }
 295 }
 296
 297 void xsk_tx_completed(struct xsk_buff_pool *pool, u32 nb_entries)
 298 {
 299         xskq_prod_submit_n(pool->cq, nb_entries);
 300 }
 301 EXPORT_SYMBOL(xsk_tx_completed);
 302
 303 void xsk_tx_release(struct xsk_buff_pool *pool)
 304 {
 305         struct xdp_sock *xs;
 306
 307         rcu_read_lock();
 308         list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) {
 309                 __xskq_cons_release(xs->tx);
 310                 if (xsk_tx_writeable(xs))
 311                         xs->sk.sk_write_space(&xs->sk);
 312         }
 313         rcu_read_unlock();
 314 }
 315 EXPORT_SYMBOL(xsk_tx_release);
 316
 317 bool xsk_tx_peek_desc(struct xsk_buff_pool *pool, struct xdp_desc *desc)
 318 {
 319         struct xdp_sock *xs;
 320
 321         rcu_read_lock();
 322         list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) {
 323                 if (!xskq_cons_peek_desc(xs->tx, desc, pool)) {
 324                         xs->tx->queue_empty_descs++;
 325                         continue;
 326                 }
 327
 328                 /* This is the backpressure mechanism for the Tx path.
 329                  * Reserve space in the completion queue and only proceed
 330                  * if there is space in it. This avoids having to implement
 331                  * any buffering in the Tx path.
 332                  */
 333                 if (xskq_prod_reserve_addr(pool->cq, desc->addr))
 334                         goto out;
 335
 336                 xskq_cons_release(xs->tx);
 337                 rcu_read_unlock();
 338                 return true;
 339         }
 340
 341 out:
 342         rcu_read_unlock();
 343         return false;
 344 }
 345 EXPORT_SYMBOL(xsk_tx_peek_desc);
 346
 347 static u32 xsk_tx_peek_release_fallback(struct xsk_buff_pool *pool, u32 max_entries)
 348 {
 349         struct xdp_desc *descs = pool->tx_descs;
 350         u32 nb_pkts = 0;
 351
 352         while (nb_pkts < max_entries && xsk_tx_peek_desc(pool, &descs[nb_pkts]))
 353                 nb_pkts++;
 354
 355         xsk_tx_release(pool);
 356         return nb_pkts;
 357 }
 358
 359 u32 xsk_tx_peek_release_desc_batch(struct xsk_buff_pool *pool, u32 nb_pkts)
 360 {
 361         struct xdp_sock *xs;
 362
 363         rcu_read_lock();
 364         if (!list_is_singular(&pool->xsk_tx_list)) {
 365                 /* Fallback to the non-batched version */
 366                 rcu_read_unlock();
 367                 return xsk_tx_peek_release_fallback(pool, nb_pkts);
 368         }
 369
 370         xs = list_first_or_null_rcu(&pool->xsk_tx_list, struct xdp_sock, tx_list);
 371         if (!xs) {
 372                 nb_pkts = 0;
 373                 goto out;
 374         }
 375
 376         nb_pkts = xskq_cons_nb_entries(xs->tx, nb_pkts);
 377
 378         /* This is the backpressure mechanism for the Tx path. Try to
 379          * reserve space in the completion queue for all packets, but
 380          * if there are fewer slots available, just process that many
 381          * packets. This avoids having to implement any buffering in
 382          * the Tx path.
 383          */
 384         nb_pkts = xskq_prod_nb_free(pool->cq, nb_pkts);
 385         if (!nb_pkts)
 386                 goto out;
 387
 388         nb_pkts = xskq_cons_read_desc_batch(xs->tx, pool, nb_pkts);
 389         if (!nb_pkts) {
 390                 xs->tx->queue_empty_descs++;
 391                 goto out;
 392         }
 393
 394         __xskq_cons_release(xs->tx);
 395         xskq_prod_write_addr_batch(pool->cq, pool->tx_descs, nb_pkts);
 396         xs->sk.sk_write_space(&xs->sk);
 397
 398 out:
 399         rcu_read_unlock();
 400         return nb_pkts;
 401 }
 402 EXPORT_SYMBOL(xsk_tx_peek_release_desc_batch);
 403
 404 static int xsk_wakeup(struct xdp_sock *xs, u8 flags)
 405 {
 406         struct net_device *dev = xs->dev;
 407
 408         return dev->netdev_ops->ndo_xsk_wakeup(dev, xs->queue_id, flags);
 409 }
 410
 411 static void xsk_destruct_skb(struct sk_buff *skb)
 412 {
 413         u64 addr = (u64)(long)skb_shinfo(skb)->destructor_arg;
 414         struct xdp_sock *xs = xdp_sk(skb->sk);
 415         unsigned long flags;
 416
 417         spin_lock_irqsave(&xs->pool->cq_lock, flags);
 418         xskq_prod_submit_addr(xs->pool->cq, addr);
 419         spin_unlock_irqrestore(&xs->pool->cq_lock, flags);
 420
 421         sock_wfree(skb);
 422 }
 423
 424 static struct sk_buff *xsk_build_skb_zerocopy(struct xdp_sock *xs,
 425                                               struct xdp_desc *desc)
 426 {
 427         struct xsk_buff_pool *pool = xs->pool;
 428         u32 hr, len, ts, offset, copy, copied;
 429         struct sk_buff *skb;
 430         struct page *page;
 431         void *buffer;
 432         int err, i;
 433         u64 addr;
 434
 435         hr = max(NET_SKB_PAD, L1_CACHE_ALIGN(xs->dev->needed_headroom));
 436
 437         skb = sock_alloc_send_skb(&xs->sk, hr, 1, &err);
 438         if (unlikely(!skb))
 439                 return ERR_PTR(err);
 440
 441         skb_reserve(skb, hr);
 442
 443         addr = desc->addr;
 444         len = desc->len;
 445         ts = pool->unaligned ? len : pool->chunk_size;
 446
 447         buffer = xsk_buff_raw_get_data(pool, addr);
 448         offset = offset_in_page(buffer);
 449         addr = buffer - pool->addrs;
 450
 451         for (copied = 0, i = 0; copied < len; i++) {
 452                 page = pool->umem->pgs[addr >> PAGE_SHIFT];
 453                 get_page(page);
 454
 455                 copy = min_t(u32, PAGE_SIZE - offset, len - copied);
 456                 skb_fill_page_desc(skb, i, page, offset, copy);
 457
 458                 copied += copy;
 459                 addr += copy;
 460                 offset = 0;
 461         }
 462
 463         skb->len += len;
 464         skb->data_len += len;
 465         skb->truesize += ts;
 466
 467         refcount_add(ts, &xs->sk.sk_wmem_alloc);
 468
 469         return skb;
 470 }
 471
 472 static struct sk_buff *xsk_build_skb(struct xdp_sock *xs,
 473                                      struct xdp_desc *desc)
 474 {
 475         struct net_device *dev = xs->dev;
 476         struct sk_buff *skb;
 477
 478         if (dev->priv_flags & IFF_TX_SKB_NO_LINEAR) {
 479                 skb = xsk_build_skb_zerocopy(xs, desc);
 480                 if (IS_ERR(skb))
 481                         return skb;
 482         } else {
 483                 u32 hr, tr, len;
 484                 void *buffer;
 485                 int err;
 486
 487                 hr = max(NET_SKB_PAD, L1_CACHE_ALIGN(dev->needed_headroom));
 488                 tr = dev->needed_tailroom;
 489                 len = desc->len;
 490
 491                 skb = sock_alloc_send_skb(&xs->sk, hr + len + tr, 1, &err);
 492                 if (unlikely(!skb))
 493                         return ERR_PTR(err);
 494
 495                 skb_reserve(skb, hr);
 496                 skb_put(skb, len);
 497
 498                 buffer = xsk_buff_raw_get_data(xs->pool, desc->addr);
 499                 err = skb_store_bits(skb, 0, buffer, len);
 500                 if (unlikely(err)) {
 501                         kfree_skb(skb);
 502                         return ERR_PTR(err);
 503                 }
 504         }
 505
 506         skb->dev = dev;
 507         skb->priority = xs->sk.sk_priority;
 508         skb->mark = READ_ONCE(xs->sk.sk_mark);
 509         skb_shinfo(skb)->destructor_arg = (void *)(long)desc->addr;
 510         skb->destructor = xsk_destruct_skb;
 511
 512         return skb;
 513 }
 514
 515 static int __xsk_generic_xmit(struct sock *sk)
 516 {
 517         struct xdp_sock *xs = xdp_sk(sk);
 518         u32 max_batch = TX_BATCH_SIZE;
 519         bool sent_frame = false;
 520         struct xdp_desc desc;
 521         struct sk_buff *skb;
 522         unsigned long flags;
 523         int err = 0;
 524
 525         mutex_lock(&xs->mutex);
 526
 527         /* Since we dropped the RCU read lock, the socket state might have changed. */
 528         if (unlikely(!xsk_is_bound(xs))) {
 529                 err = -ENXIO;
 530                 goto out;
 531         }
 532
 533         if (xs->queue_id >= xs->dev->real_num_tx_queues)
 534                 goto out;
 535
 536         while (xskq_cons_peek_desc(xs->tx, &desc, xs->pool)) {
 537                 if (max_batch-- == 0) {
 538                         err = -EAGAIN;
 539                         goto out;
 540                 }
 541
 542                 /* This is the backpressure mechanism for the Tx path.
 543                  * Reserve space in the completion queue and only proceed
 544                  * if there is space in it. This avoids having to implement
 545                  * any buffering in the Tx path.
 546                  */
 547                 spin_lock_irqsave(&xs->pool->cq_lock, flags);
 548                 if (xskq_prod_reserve(xs->pool->cq)) {
 549                         spin_unlock_irqrestore(&xs->pool->cq_lock, flags);
 550                         goto out;
 551                 }
 552                 spin_unlock_irqrestore(&xs->pool->cq_lock, flags);
 553
 554                 skb = xsk_build_skb(xs, &desc);
 555                 if (IS_ERR(skb)) {
 556                         err = PTR_ERR(skb);
 557                         spin_lock_irqsave(&xs->pool->cq_lock, flags);
 558                         xskq_prod_cancel(xs->pool->cq);
 559                         spin_unlock_irqrestore(&xs->pool->cq_lock, flags);
 560                         goto out;
 561                 }
 562
 563                 err = __dev_direct_xmit(skb, xs->queue_id);
 564                 if  (err == NETDEV_TX_BUSY) {
 565                         /* Tell user-space to retry the send */
 566                         skb->destructor = sock_wfree;
 567                         spin_lock_irqsave(&xs->pool->cq_lock, flags);
 568                         xskq_prod_cancel(xs->pool->cq);
 569                         spin_unlock_irqrestore(&xs->pool->cq_lock, flags);
 570                         /* Free skb without triggering the perf drop trace */
 571                         consume_skb(skb);
 572                         err = -EAGAIN;
 573                         goto out;
 574                 }
 575
 576                 xskq_cons_release(xs->tx);
 577                 /* Ignore NET_XMIT_CN as packet might have been sent */
 578                 if (err == NET_XMIT_DROP) {
 579                         /* SKB completed but not sent */
 580                         err = -EBUSY;
 581                         goto out;
 582                 }
 583
 584                 sent_frame = true;
 585         }
 586
 587         xs->tx->queue_empty_descs++;
 588
 589 out:
 590         if (sent_frame)
 591                 if (xsk_tx_writeable(xs))
 592                         sk->sk_write_space(sk);
 593
 594         mutex_unlock(&xs->mutex);
 595         return err;
 596 }
 597
 598 static int xsk_generic_xmit(struct sock *sk)
 599 {
 600         int ret;
 601
 602         /* Drop the RCU lock since the SKB path might sleep. */
 603         rcu_read_unlock();
 604         ret = __xsk_generic_xmit(sk);
 605         /* Reaquire RCU lock before going into common code. */
 606         rcu_read_lock();
 607
 608         return ret;
 609 }
 610
 611 static bool xsk_no_wakeup(struct sock *sk)
 612 {
 613 #ifdef CONFIG_NET_RX_BUSY_POLL
 614         /* Prefer busy-polling, skip the wakeup. */
 615         return READ_ONCE(sk->sk_prefer_busy_poll) && READ_ONCE(sk->sk_ll_usec) &&
 616                 READ_ONCE(sk->sk_napi_id) >= MIN_NAPI_ID;
 617 #else
 618         return false;
 619 #endif
 620 }
 621
 622 static int xsk_check_common(struct xdp_sock *xs)
 623 {
 624         if (unlikely(!xsk_is_bound(xs)))
 625                 return -ENXIO;
 626         if (unlikely(!(xs->dev->flags & IFF_UP)))
 627                 return -ENETDOWN;
 628
 629         return 0;
 630 }
 631
 632 static int __xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len)
 633 {
 634         bool need_wait = !(m->msg_flags & MSG_DONTWAIT);
 635         struct sock *sk = sock->sk;
 636         struct xdp_sock *xs = xdp_sk(sk);
 637         struct xsk_buff_pool *pool;
 638         int err;
 639
 640         err = xsk_check_common(xs);
 641         if (err)
 642                 return err;
 643         if (unlikely(need_wait))
 644                 return -EOPNOTSUPP;
 645         if (unlikely(!xs->tx))
 646                 return -ENOBUFS;
 647
 648         if (sk_can_busy_loop(sk)) {
 649                 if (xs->zc)
 650                         __sk_mark_napi_id_once(sk, xsk_pool_get_napi_id(xs->pool));
 651                 sk_busy_loop(sk, 1); /* only support non-blocking sockets */
 652         }
 653
 654         if (xs->zc && xsk_no_wakeup(sk))
 655                 return 0;
 656
 657         pool = xs->pool;
 658         if (pool->cached_need_wakeup & XDP_WAKEUP_TX) {
 659                 if (xs->zc)
 660                         return xsk_wakeup(xs, XDP_WAKEUP_TX);
 661                 return xsk_generic_xmit(sk);
 662         }
 663         return 0;
 664 }
 665
 666 static int xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len)
 667 {
 668         int ret;
 669
 670         rcu_read_lock();
 671         ret = __xsk_sendmsg(sock, m, total_len);
 672         rcu_read_unlock();
 673
 674         return ret;
 675 }
 676
 677 static int __xsk_recvmsg(struct socket *sock, struct msghdr *m, size_t len, int flags)
 678 {
 679         bool need_wait = !(flags & MSG_DONTWAIT);
 680         struct sock *sk = sock->sk;
 681         struct xdp_sock *xs = xdp_sk(sk);
 682         int err;
 683
 684         err = xsk_check_common(xs);
 685         if (err)
 686                 return err;
 687         if (unlikely(!xs->rx))
 688                 return -ENOBUFS;
 689         if (unlikely(need_wait))
 690                 return -EOPNOTSUPP;
 691
 692         if (sk_can_busy_loop(sk))
 693                 sk_busy_loop(sk, 1); /* only support non-blocking sockets */
 694
 695         if (xsk_no_wakeup(sk))
 696                 return 0;
 697
 698         if (xs->pool->cached_need_wakeup & XDP_WAKEUP_RX && xs->zc)
 699                 return xsk_wakeup(xs, XDP_WAKEUP_RX);
 700         return 0;
 701 }
 702
 703 static int xsk_recvmsg(struct socket *sock, struct msghdr *m, size_t len, int flags)
 704 {
 705         int ret;
 706
 707         rcu_read_lock();
 708         ret = __xsk_recvmsg(sock, m, len, flags);
 709         rcu_read_unlock();
 710
 711         return ret;
 712 }
 713
 714 static __poll_t xsk_poll(struct file *file, struct socket *sock,
 715                              struct poll_table_struct *wait)
 716 {
 717         __poll_t mask = 0;
 718         struct sock *sk = sock->sk;
 719         struct xdp_sock *xs = xdp_sk(sk);
 720         struct xsk_buff_pool *pool;
 721
 722         sock_poll_wait(file, sock, wait);
 723
 724         rcu_read_lock();
 725         if (xsk_check_common(xs))
 726                 goto skip_tx;
 727
 728         pool = xs->pool;
 729
 730         if (pool->cached_need_wakeup) {
 731                 if (xs->zc)
 732                         xsk_wakeup(xs, pool->cached_need_wakeup);
 733                 else if (xs->tx)
 734                         /* Poll needs to drive Tx also in copy mode */
 735                         xsk_generic_xmit(sk);
 736         }
 737
 738 skip_tx:
 739         if (xs->rx && !xskq_prod_is_empty(xs->rx))
 740                 mask |= EPOLLIN | EPOLLRDNORM;
 741         if (xs->tx && xsk_tx_writeable(xs))
 742                 mask |= EPOLLOUT | EPOLLWRNORM;
 743
 744         rcu_read_unlock();
 745         return mask;
 746 }
 747
 748 static int xsk_init_queue(u32 entries, struct xsk_queue **queue,
 749                           bool umem_queue)
 750 {
 751         struct xsk_queue *q;
 752
 753         if (entries == 0 || *queue || !is_power_of_2(entries))
 754                 return -EINVAL;
 755
 756         q = xskq_create(entries, umem_queue);
 757         if (!q)
 758                 return -ENOMEM;
 759
 760         /* Make sure queue is ready before it can be seen by others */
 761         smp_wmb();
 762         WRITE_ONCE(*queue, q);
 763         return 0;
 764 }
 765
 766 static void xsk_unbind_dev(struct xdp_sock *xs)
 767 {
 768         struct net_device *dev = xs->dev;
 769
 770         if (xs->state != XSK_BOUND)
 771                 return;
 772         WRITE_ONCE(xs->state, XSK_UNBOUND);
 773
 774         /* Wait for driver to stop using the xdp socket. */
 775         xp_del_xsk(xs->pool, xs);
 776         synchronize_net();
 777         dev_put(dev);
 778 }
 779
 780 static struct xsk_map *xsk_get_map_list_entry(struct xdp_sock *xs,
 781                                               struct xdp_sock __rcu ***map_entry)
 782 {
 783         struct xsk_map *map = NULL;
 784         struct xsk_map_node *node;
 785
 786         *map_entry = NULL;
 787
 788         spin_lock_bh(&xs->map_list_lock);
 789         node = list_first_entry_or_null(&xs->map_list, struct xsk_map_node,
 790                                         node);
 791         if (node) {
 792                 bpf_map_inc(&node->map->map);
 793                 map = node->map;
 794                 *map_entry = node->map_entry;
 795         }
 796         spin_unlock_bh(&xs->map_list_lock);
 797         return map;
 798 }
 799
 800 static void xsk_delete_from_maps(struct xdp_sock *xs)
 801 {
 802         /* This function removes the current XDP socket from all the
 803          * maps it resides in. We need to take extra care here, due to
 804          * the two locks involved. Each map has a lock synchronizing
 805          * updates to the entries, and each socket has a lock that
 806          * synchronizes access to the list of maps (map_list). For
 807          * deadlock avoidance the locks need to be taken in the order
 808          * "map lock"->"socket map list lock". We start off by
 809          * accessing the socket map list, and take a reference to the
 810          * map to guarantee existence between the
 811          * xsk_get_map_list_entry() and xsk_map_try_sock_delete()
 812          * calls. Then we ask the map to remove the socket, which
 813          * tries to remove the socket from the map. Note that there
 814          * might be updates to the map between
 815          * xsk_get_map_list_entry() and xsk_map_try_sock_delete().
 816          */
 817         struct xdp_sock __rcu **map_entry = NULL;
 818         struct xsk_map *map;
 819
 820         while ((map = xsk_get_map_list_entry(xs, &map_entry))) {
 821                 xsk_map_try_sock_delete(map, xs, map_entry);
 822                 bpf_map_put(&map->map);
 823         }
 824 }
 825
 826 static int xsk_release(struct socket *sock)
 827 {
 828         struct sock *sk = sock->sk;
 829         struct xdp_sock *xs = xdp_sk(sk);
 830         struct net *net;
 831
 832         if (!sk)
 833                 return 0;
 834
 835         net = sock_net(sk);
 836
 837         mutex_lock(&net->xdp.lock);
 838         sk_del_node_init_rcu(sk);
 839         mutex_unlock(&net->xdp.lock);
 840
 841         sock_prot_inuse_add(net, sk->sk_prot, -1);
 842
 843         xsk_delete_from_maps(xs);
 844         mutex_lock(&xs->mutex);
 845         xsk_unbind_dev(xs);
 846         mutex_unlock(&xs->mutex);
 847
 848         xskq_destroy(xs->rx);
 849         xskq_destroy(xs->tx);
 850         xskq_destroy(xs->fq_tmp);
 851         xskq_destroy(xs->cq_tmp);
 852
 853         sock_orphan(sk);
 854         sock->sk = NULL;
 855
 856         sock_put(sk);
 857
 858         return 0;
 859 }
 860
 861 static struct socket *xsk_lookup_xsk_from_fd(int fd)
 862 {
 863         struct socket *sock;
 864         int err;
 865
 866         sock = sockfd_lookup(fd, &err);
 867         if (!sock)
 868                 return ERR_PTR(-ENOTSOCK);
 869
 870         if (sock->sk->sk_family != PF_XDP) {
 871                 sockfd_put(sock);
 872                 return ERR_PTR(-ENOPROTOOPT);
 873         }
 874
 875         return sock;
 876 }
 877
 878 static bool xsk_validate_queues(struct xdp_sock *xs)
 879 {
 880         return xs->fq_tmp && xs->cq_tmp;
 881 }
 882
 883 static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
 884 {
 885         struct sockaddr_xdp *sxdp = (struct sockaddr_xdp *)addr;
 886         struct sock *sk = sock->sk;
 887         struct xdp_sock *xs = xdp_sk(sk);
 888         struct net_device *dev;
 889         int bound_dev_if;
 890         u32 flags, qid;
 891         int err = 0;
 892
 893         if (addr_len < sizeof(struct sockaddr_xdp))
 894                 return -EINVAL;
 895         if (sxdp->sxdp_family != AF_XDP)
 896                 return -EINVAL;
 897
 898         flags = sxdp->sxdp_flags;
 899         if (flags & ~(XDP_SHARED_UMEM | XDP_COPY | XDP_ZEROCOPY |
 900                       XDP_USE_NEED_WAKEUP))
 901                 return -EINVAL;
 902
 903         bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
 904         if (bound_dev_if && bound_dev_if != sxdp->sxdp_ifindex)
 905                 return -EINVAL;
 906
 907         rtnl_lock();
 908         mutex_lock(&xs->mutex);
 909         if (xs->state != XSK_READY) {
 910                 err = -EBUSY;
 911                 goto out_release;
 912         }
 913
 914         dev = dev_get_by_index(sock_net(sk), sxdp->sxdp_ifindex);
 915         if (!dev) {
 916                 err = -ENODEV;
 917                 goto out_release;
 918         }
 919
 920         if (!xs->rx && !xs->tx) {
 921                 err = -EINVAL;
 922                 goto out_unlock;
 923         }
 924
 925         qid = sxdp->sxdp_queue_id;
 926
 927         if (flags & XDP_SHARED_UMEM) {
 928                 struct xdp_sock *umem_xs;
 929                 struct socket *sock;
 930
 931                 if ((flags & XDP_COPY) || (flags & XDP_ZEROCOPY) ||
 932                     (flags & XDP_USE_NEED_WAKEUP)) {
 933                         /* Cannot specify flags for shared sockets. */
 934                         err = -EINVAL;
 935                         goto out_unlock;
 936                 }
 937
 938                 if (xs->umem) {
 939                         /* We have already our own. */
 940                         err = -EINVAL;
 941                         goto out_unlock;
 942                 }
 943
 944                 sock = xsk_lookup_xsk_from_fd(sxdp->sxdp_shared_umem_fd);
 945                 if (IS_ERR(sock)) {
 946                         err = PTR_ERR(sock);
 947                         goto out_unlock;
 948                 }
 949
 950                 umem_xs = xdp_sk(sock->sk);
 951                 if (!xsk_is_bound(umem_xs)) {
 952                         err = -EBADF;
 953                         sockfd_put(sock);
 954                         goto out_unlock;
 955                 }
 956
 957                 if (umem_xs->queue_id != qid || umem_xs->dev != dev) {
 958                         /* Share the umem with another socket on another qid
 959                          * and/or device.
 960                          */
 961                         xs->pool = xp_create_and_assign_umem(xs,
 962                                                              umem_xs->umem);
 963                         if (!xs->pool) {
 964                                 err = -ENOMEM;
 965                                 sockfd_put(sock);
 966                                 goto out_unlock;
 967                         }
 968
 969                         err = xp_assign_dev_shared(xs->pool, umem_xs, dev,
 970                                                    qid);
 971                         if (err) {
 972                                 xp_destroy(xs->pool);
 973                                 xs->pool = NULL;
 974                                 sockfd_put(sock);
 975                                 goto out_unlock;
 976                         }
 977                 } else {
 978                         /* Share the buffer pool with the other socket. */
 979                         if (xs->fq_tmp || xs->cq_tmp) {
 980                                 /* Do not allow setting your own fq or cq. */
 981                                 err = -EINVAL;
 982                                 sockfd_put(sock);
 983                                 goto out_unlock;
 984                         }
 985
 986                         xp_get_pool(umem_xs->pool);
 987                         xs->pool = umem_xs->pool;
 988
 989                         /* If underlying shared umem was created without Tx
 990                          * ring, allocate Tx descs array that Tx batching API
 991                          * utilizes
 992                          */
 993                         if (xs->tx && !xs->pool->tx_descs) {
 994                                 err = xp_alloc_tx_descs(xs->pool, xs);
 995                                 if (err) {
 996                                         xp_put_pool(xs->pool);
 997                                         xs->pool = NULL;
 998                                         sockfd_put(sock);
 999                                         goto out_unlock;
1000                                 }
1001                         }
1002                 }
1003
1004                 xdp_get_umem(umem_xs->umem);
1005                 WRITE_ONCE(xs->umem, umem_xs->umem);
1006                 sockfd_put(sock);
1007         } else if (!xs->umem || !xsk_validate_queues(xs)) {
1008                 err = -EINVAL;
1009                 goto out_unlock;
1010         } else {
1011                 /* This xsk has its own umem. */
1012                 xs->pool = xp_create_and_assign_umem(xs, xs->umem);
1013                 if (!xs->pool) {
1014                         err = -ENOMEM;
1015                         goto out_unlock;
1016                 }
1017
1018                 err = xp_assign_dev(xs->pool, dev, qid, flags);
1019                 if (err) {
1020                         xp_destroy(xs->pool);
1021                         xs->pool = NULL;
1022                         goto out_unlock;
1023                 }
1024         }
1025
1026         /* FQ and CQ are now owned by the buffer pool and cleaned up with it. */
1027         xs->fq_tmp = NULL;
1028         xs->cq_tmp = NULL;
1029
1030         xs->dev = dev;
1031         xs->zc = xs->umem->zc;
1032         xs->queue_id = qid;
1033         xp_add_xsk(xs->pool, xs);
1034
1035 out_unlock:
1036         if (err) {
1037                 dev_put(dev);
1038         } else {
1039                 /* Matches smp_rmb() in bind() for shared umem
1040                  * sockets, and xsk_is_bound().
1041                  */
1042                 smp_wmb();
1043                 WRITE_ONCE(xs->state, XSK_BOUND);
1044         }
1045 out_release:
1046         mutex_unlock(&xs->mutex);
1047         rtnl_unlock();
1048         return err;
1049 }
1050
1051 struct xdp_umem_reg_v1 {
1052         __u64 addr; /* Start of packet data area */
1053         __u64 len; /* Length of packet data area */
1054         __u32 chunk_size;
1055         __u32 headroom;
1056 };
1057
1058 static int xsk_setsockopt(struct socket *sock, int level, int optname,
1059                           sockptr_t optval, unsigned int optlen)
1060 {
1061         struct sock *sk = sock->sk;
1062         struct xdp_sock *xs = xdp_sk(sk);
1063         int err;
1064
1065         if (level != SOL_XDP)
1066                 return -ENOPROTOOPT;
1067
1068         switch (optname) {
1069         case XDP_RX_RING:
1070         case XDP_TX_RING:
1071         {
1072                 struct xsk_queue **q;
1073                 int entries;
1074
1075                 if (optlen < sizeof(entries))
1076                         return -EINVAL;
1077                 if (copy_from_sockptr(&entries, optval, sizeof(entries)))
1078                         return -EFAULT;
1079
1080                 mutex_lock(&xs->mutex);
1081                 if (xs->state != XSK_READY) {
1082                         mutex_unlock(&xs->mutex);
1083                         return -EBUSY;
1084                 }
1085                 q = (optname == XDP_TX_RING) ? &xs->tx : &xs->rx;
1086                 err = xsk_init_queue(entries, q, false);
1087                 if (!err && optname == XDP_TX_RING)
1088                         /* Tx needs to be explicitly woken up the first time */
1089                         xs->tx->ring->flags |= XDP_RING_NEED_WAKEUP;
1090                 mutex_unlock(&xs->mutex);
1091                 return err;
1092         }
1093         case XDP_UMEM_REG:
1094         {
1095                 size_t mr_size = sizeof(struct xdp_umem_reg);
1096                 struct xdp_umem_reg mr = {};
1097                 struct xdp_umem *umem;
1098
1099                 if (optlen < sizeof(struct xdp_umem_reg_v1))
1100                         return -EINVAL;
1101                 else if (optlen < sizeof(mr))
1102                         mr_size = sizeof(struct xdp_umem_reg_v1);
1103
1104                 if (copy_from_sockptr(&mr, optval, mr_size))
1105                         return -EFAULT;
1106
1107                 mutex_lock(&xs->mutex);
1108                 if (xs->state != XSK_READY || xs->umem) {
1109                         mutex_unlock(&xs->mutex);
1110                         return -EBUSY;
1111                 }
1112
1113                 umem = xdp_umem_create(&mr);
1114                 if (IS_ERR(umem)) {
1115                         mutex_unlock(&xs->mutex);
1116                         return PTR_ERR(umem);
1117                 }
1118
1119                 /* Make sure umem is ready before it can be seen by others */
1120                 smp_wmb();
1121                 WRITE_ONCE(xs->umem, umem);
1122                 mutex_unlock(&xs->mutex);
1123                 return 0;
1124         }
1125         case XDP_UMEM_FILL_RING:
1126         case XDP_UMEM_COMPLETION_RING:
1127         {
1128                 struct xsk_queue **q;
1129                 int entries;
1130
1131                 if (copy_from_sockptr(&entries, optval, sizeof(entries)))
1132                         return -EFAULT;
1133
1134                 mutex_lock(&xs->mutex);
1135                 if (xs->state != XSK_READY) {
1136                         mutex_unlock(&xs->mutex);
1137                         return -EBUSY;
1138                 }
1139
1140                 q = (optname == XDP_UMEM_FILL_RING) ? &xs->fq_tmp :
1141                         &xs->cq_tmp;
1142                 err = xsk_init_queue(entries, q, true);
1143                 mutex_unlock(&xs->mutex);
1144                 return err;
1145         }
1146         default:
1147                 break;
1148         }
1149
1150         return -ENOPROTOOPT;
1151 }
1152
1153 static void xsk_enter_rxtx_offsets(struct xdp_ring_offset_v1 *ring)
1154 {
1155         ring->producer = offsetof(struct xdp_rxtx_ring, ptrs.producer);
1156         ring->consumer = offsetof(struct xdp_rxtx_ring, ptrs.consumer);
1157         ring->desc = offsetof(struct xdp_rxtx_ring, desc);
1158 }
1159
1160 static void xsk_enter_umem_offsets(struct xdp_ring_offset_v1 *ring)
1161 {
1162         ring->producer = offsetof(struct xdp_umem_ring, ptrs.producer);
1163         ring->consumer = offsetof(struct xdp_umem_ring, ptrs.consumer);
1164         ring->desc = offsetof(struct xdp_umem_ring, desc);
1165 }
1166
1167 struct xdp_statistics_v1 {
1168         __u64 rx_dropped;
1169         __u64 rx_invalid_descs;
1170         __u64 tx_invalid_descs;
1171 };
1172
1173 static int xsk_getsockopt(struct socket *sock, int level, int optname,
1174                           char __user *optval, int __user *optlen)
1175 {
1176         struct sock *sk = sock->sk;
1177         struct xdp_sock *xs = xdp_sk(sk);
1178         int len;
1179
1180         if (level != SOL_XDP)
1181                 return -ENOPROTOOPT;
1182
1183         if (get_user(len, optlen))
1184                 return -EFAULT;
1185         if (len < 0)
1186                 return -EINVAL;
1187
1188         switch (optname) {
1189         case XDP_STATISTICS:
1190         {
1191                 struct xdp_statistics stats = {};
1192                 bool extra_stats = true;
1193                 size_t stats_size;
1194
1195                 if (len < sizeof(struct xdp_statistics_v1)) {
1196                         return -EINVAL;
1197                 } else if (len < sizeof(stats)) {
1198                         extra_stats = false;
1199                         stats_size = sizeof(struct xdp_statistics_v1);
1200                 } else {
1201                         stats_size = sizeof(stats);
1202                 }
1203
1204                 mutex_lock(&xs->mutex);
1205                 stats.rx_dropped = xs->rx_dropped;
1206                 if (extra_stats) {
1207                         stats.rx_ring_full = xs->rx_queue_full;
1208                         stats.rx_fill_ring_empty_descs =
1209                                 xs->pool ? xskq_nb_queue_empty_descs(xs->pool->fq) : 0;
1210                         stats.tx_ring_empty_descs = xskq_nb_queue_empty_descs(xs->tx);
1211                 } else {
1212                         stats.rx_dropped += xs->rx_queue_full;
1213                 }
1214                 stats.rx_invalid_descs = xskq_nb_invalid_descs(xs->rx);
1215                 stats.tx_invalid_descs = xskq_nb_invalid_descs(xs->tx);
1216                 mutex_unlock(&xs->mutex);
1217
1218                 if (copy_to_user(optval, &stats, stats_size))
1219                         return -EFAULT;
1220                 if (put_user(stats_size, optlen))
1221                         return -EFAULT;
1222
1223                 return 0;
1224         }
1225         case XDP_MMAP_OFFSETS:
1226         {
1227                 struct xdp_mmap_offsets off;
1228                 struct xdp_mmap_offsets_v1 off_v1;
1229                 bool flags_supported = true;
1230                 void *to_copy;
1231
1232                 if (len < sizeof(off_v1))
1233                         return -EINVAL;
1234                 else if (len < sizeof(off))
1235                         flags_supported = false;
1236
1237                 if (flags_supported) {
1238                         /* xdp_ring_offset is identical to xdp_ring_offset_v1
1239                          * except for the flags field added to the end.
1240                          */
1241                         xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *)
1242                                                &off.rx);
1243                         xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *)
1244                                                &off.tx);
1245                         xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *)
1246                                                &off.fr);
1247                         xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *)
1248                                                &off.cr);
1249                         off.rx.flags = offsetof(struct xdp_rxtx_ring,
1250                                                 ptrs.flags);
1251                         off.tx.flags = offsetof(struct xdp_rxtx_ring,
1252                                                 ptrs.flags);
1253                         off.fr.flags = offsetof(struct xdp_umem_ring,
1254                                                 ptrs.flags);
1255                         off.cr.flags = offsetof(struct xdp_umem_ring,
1256                                                 ptrs.flags);
1257
1258                         len = sizeof(off);
1259                         to_copy = &off;
1260                 } else {
1261                         xsk_enter_rxtx_offsets(&off_v1.rx);
1262                         xsk_enter_rxtx_offsets(&off_v1.tx);
1263                         xsk_enter_umem_offsets(&off_v1.fr);
1264                         xsk_enter_umem_offsets(&off_v1.cr);
1265
1266                         len = sizeof(off_v1);
1267                         to_copy = &off_v1;
1268                 }
1269
1270                 if (copy_to_user(optval, to_copy, len))
1271                         return -EFAULT;
1272                 if (put_user(len, optlen))
1273                         return -EFAULT;
1274
1275                 return 0;
1276         }
1277         case XDP_OPTIONS:
1278         {
1279                 struct xdp_options opts = {};
1280
1281                 if (len < sizeof(opts))
1282                         return -EINVAL;
1283
1284                 mutex_lock(&xs->mutex);
1285                 if (xs->zc)
1286                         opts.flags |= XDP_OPTIONS_ZEROCOPY;
1287                 mutex_unlock(&xs->mutex);
1288
1289                 len = sizeof(opts);
1290                 if (copy_to_user(optval, &opts, len))
1291                         return -EFAULT;
1292                 if (put_user(len, optlen))
1293                         return -EFAULT;
1294
1295                 return 0;
1296         }
1297         default:
1298                 break;
1299         }
1300
1301         return -EOPNOTSUPP;
1302 }
1303
1304 static int xsk_mmap(struct file *file, struct socket *sock,
1305                     struct vm_area_struct *vma)
1306 {
1307         loff_t offset = (loff_t)vma->vm_pgoff << PAGE_SHIFT;
1308         unsigned long size = vma->vm_end - vma->vm_start;
1309         struct xdp_sock *xs = xdp_sk(sock->sk);
1310         int state = READ_ONCE(xs->state);
1311         struct xsk_queue *q = NULL;
1312
1313         if (state != XSK_READY && state != XSK_BOUND)
1314                 return -EBUSY;
1315
1316         if (offset == XDP_PGOFF_RX_RING) {
1317                 q = READ_ONCE(xs->rx);
1318         } else if (offset == XDP_PGOFF_TX_RING) {
1319                 q = READ_ONCE(xs->tx);
1320         } else {
1321                 /* Matches the smp_wmb() in XDP_UMEM_REG */
1322                 smp_rmb();
1323                 if (offset == XDP_UMEM_PGOFF_FILL_RING)
1324                         q = state == XSK_READY ? READ_ONCE(xs->fq_tmp) :
1325                                                  READ_ONCE(xs->pool->fq);
1326                 else if (offset == XDP_UMEM_PGOFF_COMPLETION_RING)
1327                         q = state == XSK_READY ? READ_ONCE(xs->cq_tmp) :
1328                                                  READ_ONCE(xs->pool->cq);
1329         }
1330
1331         if (!q)
1332                 return -EINVAL;
1333
1334         /* Matches the smp_wmb() in xsk_init_queue */
1335         smp_rmb();
1336         if (size > q->ring_vmalloc_size)
1337                 return -EINVAL;
1338
1339         return remap_vmalloc_range(vma, q->ring, 0);
1340 }
1341
1342 static int xsk_notifier(struct notifier_block *this,
1343                         unsigned long msg, void *ptr)
1344 {
1345         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1346         struct net *net = dev_net(dev);
1347         struct sock *sk;
1348
1349         switch (msg) {
1350         case NETDEV_UNREGISTER:
1351                 mutex_lock(&net->xdp.lock);
1352                 sk_for_each(sk, &net->xdp.list) {
1353                         struct xdp_sock *xs = xdp_sk(sk);
1354
1355                         mutex_lock(&xs->mutex);
1356                         if (xs->dev == dev) {
1357                                 sk->sk_err = ENETDOWN;
1358                                 if (!sock_flag(sk, SOCK_DEAD))
1359                                         sk_error_report(sk);
1360
1361                                 xsk_unbind_dev(xs);
1362
1363                                 /* Clear device references. */
1364                                 xp_clear_dev(xs->pool);
1365                         }
1366                         mutex_unlock(&xs->mutex);
1367                 }
1368                 mutex_unlock(&net->xdp.lock);
1369                 break;
1370         }
1371         return NOTIFY_DONE;
1372 }
1373
1374 static struct proto xsk_proto = {
1375         .name =         "XDP",
1376         .owner =        THIS_MODULE,
1377         .obj_size =     sizeof(struct xdp_sock),
1378 };
1379
1380 static const struct proto_ops xsk_proto_ops = {
1381         .family         = PF_XDP,
1382         .owner          = THIS_MODULE,
1383         .release        = xsk_release,
1384         .bind           = xsk_bind,
1385         .connect        = sock_no_connect,
1386         .socketpair     = sock_no_socketpair,
1387         .accept         = sock_no_accept,
1388         .getname        = sock_no_getname,
1389         .poll           = xsk_poll,
1390         .ioctl          = sock_no_ioctl,
1391         .listen         = sock_no_listen,
1392         .shutdown       = sock_no_shutdown,
1393         .setsockopt     = xsk_setsockopt,
1394         .getsockopt     = xsk_getsockopt,
1395         .sendmsg        = xsk_sendmsg,
1396         .recvmsg        = xsk_recvmsg,
1397         .mmap           = xsk_mmap,
1398 };
1399
1400 static void xsk_destruct(struct sock *sk)
1401 {
1402         struct xdp_sock *xs = xdp_sk(sk);
1403
1404         if (!sock_flag(sk, SOCK_DEAD))
1405                 return;
1406
1407         if (!xp_put_pool(xs->pool))
1408                 xdp_put_umem(xs->umem, !xs->pool);
1409 }
1410
1411 static int xsk_create(struct net *net, struct socket *sock, int protocol,
1412                       int kern)
1413 {
1414         struct xdp_sock *xs;
1415         struct sock *sk;
1416
1417         if (!ns_capable(net->user_ns, CAP_NET_RAW))
1418                 return -EPERM;
1419         if (sock->type != SOCK_RAW)
1420                 return -ESOCKTNOSUPPORT;
1421
1422         if (protocol)
1423                 return -EPROTONOSUPPORT;
1424
1425         sock->state = SS_UNCONNECTED;
1426
1427         sk = sk_alloc(net, PF_XDP, GFP_KERNEL, &xsk_proto, kern);
1428         if (!sk)
1429                 return -ENOBUFS;
1430
1431         sock->ops = &xsk_proto_ops;
1432
1433         sock_init_data(sock, sk);
1434
1435         sk->sk_family = PF_XDP;
1436
1437         sk->sk_destruct = xsk_destruct;
1438
1439         sock_set_flag(sk, SOCK_RCU_FREE);
1440
1441         xs = xdp_sk(sk);
1442         xs->state = XSK_READY;
1443         mutex_init(&xs->mutex);
1444         spin_lock_init(&xs->rx_lock);
1445
1446         INIT_LIST_HEAD(&xs->map_list);
1447         spin_lock_init(&xs->map_list_lock);
1448
1449         mutex_lock(&net->xdp.lock);
1450         sk_add_node_rcu(sk, &net->xdp.list);
1451         mutex_unlock(&net->xdp.lock);
1452
1453         sock_prot_inuse_add(net, &xsk_proto, 1);
1454
1455         return 0;
1456 }
1457
1458 static const struct net_proto_family xsk_family_ops = {
1459         .family = PF_XDP,
1460         .create = xsk_create,
1461         .owner  = THIS_MODULE,
1462 };
1463
1464 static struct notifier_block xsk_netdev_notifier = {
1465         .notifier_call  = xsk_notifier,
1466 };
1467
1468 static int __net_init xsk_net_init(struct net *net)
1469 {
1470         mutex_init(&net->xdp.lock);
1471         INIT_HLIST_HEAD(&net->xdp.list);
1472         return 0;
1473 }
1474
1475 static void __net_exit xsk_net_exit(struct net *net)
1476 {
1477         WARN_ON_ONCE(!hlist_empty(&net->xdp.list));
1478 }
1479
1480 static struct pernet_operations xsk_net_ops = {
1481         .init = xsk_net_init,
1482         .exit = xsk_net_exit,
1483 };
1484
1485 static int __init xsk_init(void)
1486 {
1487         int err, cpu;
1488
1489         err = proto_register(&xsk_proto, 0 /* no slab */);
1490         if (err)
1491                 goto out;
1492
1493         err = sock_register(&xsk_family_ops);
1494         if (err)
1495                 goto out_proto;
1496
1497         err = register_pernet_subsys(&xsk_net_ops);
1498         if (err)
1499                 goto out_sk;
1500
1501         err = register_netdevice_notifier(&xsk_netdev_notifier);
1502         if (err)
1503                 goto out_pernet;
1504
1505         for_each_possible_cpu(cpu)
1506                 INIT_LIST_HEAD(&per_cpu(xskmap_flush_list, cpu));
1507         return 0;
1508
1509 out_pernet:
1510         unregister_pernet_subsys(&xsk_net_ops);
1511 out_sk:
1512         sock_unregister(PF_XDP);
1513 out_proto:
1514         proto_unregister(&xsk_proto);
1515 out:
1516         return err;
1517 }
1518
1519 fs_initcall(xsk_init);