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