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.h>
  26 #include <net/xdp.h>
  27
  28 #include "xsk_queue.h"
  29 #include "xdp_umem.h"
  30
  31 #define TX_BATCH_SIZE 16
  32
  33 static struct xdp_sock *xdp_sk(struct sock *sk)
  34 {
  35         return (struct xdp_sock *)sk;
  36 }
  37
  38 bool xsk_is_setup_for_bpf_map(struct xdp_sock *xs)
  39 {
  40         return READ_ONCE(xs->rx) &&  READ_ONCE(xs->umem) &&
  41                 READ_ONCE(xs->umem->fq);
  42 }
  43
  44 u64 *xsk_umem_peek_addr(struct xdp_umem *umem, u64 *addr)
  45 {
  46         return xskq_peek_addr(umem->fq, addr);
  47 }
  48 EXPORT_SYMBOL(xsk_umem_peek_addr);
  49
  50 void xsk_umem_discard_addr(struct xdp_umem *umem)
  51 {
  52         xskq_discard_addr(umem->fq);
  53 }
  54 EXPORT_SYMBOL(xsk_umem_discard_addr);
  55
  56 static int __xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len)
  57 {
  58         void *buffer;
  59         u64 addr;
  60         int err;
  61
  62         if (!xskq_peek_addr(xs->umem->fq, &addr) ||
  63             len > xs->umem->chunk_size_nohr) {
  64                 xs->rx_dropped++;
  65                 return -ENOSPC;
  66         }
  67
  68         addr += xs->umem->headroom;
  69
  70         buffer = xdp_umem_get_data(xs->umem, addr);
  71         memcpy(buffer, xdp->data, len);
  72         err = xskq_produce_batch_desc(xs->rx, addr, len);
  73         if (!err) {
  74                 xskq_discard_addr(xs->umem->fq);
  75                 xdp_return_buff(xdp);
  76                 return 0;
  77         }
  78
  79         xs->rx_dropped++;
  80         return err;
  81 }
  82
  83 static int __xsk_rcv_zc(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len)
  84 {
  85         int err = xskq_produce_batch_desc(xs->rx, (u64)xdp->handle, len);
  86
  87         if (err)
  88                 xs->rx_dropped++;
  89
  90         return err;
  91 }
  92
  93 int xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
  94 {
  95         u32 len;
  96
  97         if (xs->dev != xdp->rxq->dev || xs->queue_id != xdp->rxq->queue_index)
  98                 return -EINVAL;
  99
 100         len = xdp->data_end - xdp->data;
 101
 102         return (xdp->rxq->mem.type == MEM_TYPE_ZERO_COPY) ?
 103                 __xsk_rcv_zc(xs, xdp, len) : __xsk_rcv(xs, xdp, len);
 104 }
 105
 106 void xsk_flush(struct xdp_sock *xs)
 107 {
 108         xskq_produce_flush_desc(xs->rx);
 109         xs->sk.sk_data_ready(&xs->sk);
 110 }
 111
 112 int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
 113 {
 114         u32 len = xdp->data_end - xdp->data;
 115         void *buffer;
 116         u64 addr;
 117         int err;
 118
 119         if (xs->dev != xdp->rxq->dev || xs->queue_id != xdp->rxq->queue_index)
 120                 return -EINVAL;
 121
 122         if (!xskq_peek_addr(xs->umem->fq, &addr) ||
 123             len > xs->umem->chunk_size_nohr) {
 124                 xs->rx_dropped++;
 125                 return -ENOSPC;
 126         }
 127
 128         addr += xs->umem->headroom;
 129
 130         buffer = xdp_umem_get_data(xs->umem, addr);
 131         memcpy(buffer, xdp->data, len);
 132         err = xskq_produce_batch_desc(xs->rx, addr, len);
 133         if (!err) {
 134                 xskq_discard_addr(xs->umem->fq);
 135                 xsk_flush(xs);
 136                 return 0;
 137         }
 138
 139         xs->rx_dropped++;
 140         return err;
 141 }
 142
 143 void xsk_umem_complete_tx(struct xdp_umem *umem, u32 nb_entries)
 144 {
 145         xskq_produce_flush_addr_n(umem->cq, nb_entries);
 146 }
 147 EXPORT_SYMBOL(xsk_umem_complete_tx);
 148
 149 void xsk_umem_consume_tx_done(struct xdp_umem *umem)
 150 {
 151         struct xdp_sock *xs;
 152
 153         rcu_read_lock();
 154         list_for_each_entry_rcu(xs, &umem->xsk_list, list) {
 155                 xs->sk.sk_write_space(&xs->sk);
 156         }
 157         rcu_read_unlock();
 158 }
 159 EXPORT_SYMBOL(xsk_umem_consume_tx_done);
 160
 161 bool xsk_umem_consume_tx(struct xdp_umem *umem, dma_addr_t *dma, u32 *len)
 162 {
 163         struct xdp_desc desc;
 164         struct xdp_sock *xs;
 165
 166         rcu_read_lock();
 167         list_for_each_entry_rcu(xs, &umem->xsk_list, list) {
 168                 if (!xskq_peek_desc(xs->tx, &desc))
 169                         continue;
 170
 171                 if (xskq_produce_addr_lazy(umem->cq, desc.addr))
 172                         goto out;
 173
 174                 *dma = xdp_umem_get_dma(umem, desc.addr);
 175                 *len = desc.len;
 176
 177                 xskq_discard_desc(xs->tx);
 178                 rcu_read_unlock();
 179                 return true;
 180         }
 181
 182 out:
 183         rcu_read_unlock();
 184         return false;
 185 }
 186 EXPORT_SYMBOL(xsk_umem_consume_tx);
 187
 188 static int xsk_zc_xmit(struct sock *sk)
 189 {
 190         struct xdp_sock *xs = xdp_sk(sk);
 191         struct net_device *dev = xs->dev;
 192
 193         return dev->netdev_ops->ndo_xsk_async_xmit(dev, xs->queue_id);
 194 }
 195
 196 static void xsk_destruct_skb(struct sk_buff *skb)
 197 {
 198         u64 addr = (u64)(long)skb_shinfo(skb)->destructor_arg;
 199         struct xdp_sock *xs = xdp_sk(skb->sk);
 200         unsigned long flags;
 201
 202         spin_lock_irqsave(&xs->tx_completion_lock, flags);
 203         WARN_ON_ONCE(xskq_produce_addr(xs->umem->cq, addr));
 204         spin_unlock_irqrestore(&xs->tx_completion_lock, flags);
 205
 206         sock_wfree(skb);
 207 }
 208
 209 static int xsk_generic_xmit(struct sock *sk, struct msghdr *m,
 210                             size_t total_len)
 211 {
 212         u32 max_batch = TX_BATCH_SIZE;
 213         struct xdp_sock *xs = xdp_sk(sk);
 214         bool sent_frame = false;
 215         struct xdp_desc desc;
 216         struct sk_buff *skb;
 217         int err = 0;
 218
 219         mutex_lock(&xs->mutex);
 220
 221         while (xskq_peek_desc(xs->tx, &desc)) {
 222                 char *buffer;
 223                 u64 addr;
 224                 u32 len;
 225
 226                 if (max_batch-- == 0) {
 227                         err = -EAGAIN;
 228                         goto out;
 229                 }
 230
 231                 if (xskq_reserve_addr(xs->umem->cq))
 232                         goto out;
 233
 234                 if (xs->queue_id >= xs->dev->real_num_tx_queues)
 235                         goto out;
 236
 237                 len = desc.len;
 238                 skb = sock_alloc_send_skb(sk, len, 1, &err);
 239                 if (unlikely(!skb)) {
 240                         err = -EAGAIN;
 241                         goto out;
 242                 }
 243
 244                 skb_put(skb, len);
 245                 addr = desc.addr;
 246                 buffer = xdp_umem_get_data(xs->umem, addr);
 247                 err = skb_store_bits(skb, 0, buffer, len);
 248                 if (unlikely(err)) {
 249                         kfree_skb(skb);
 250                         goto out;
 251                 }
 252
 253                 skb->dev = xs->dev;
 254                 skb->priority = sk->sk_priority;
 255                 skb->mark = sk->sk_mark;
 256                 skb_shinfo(skb)->destructor_arg = (void *)(long)addr;
 257                 skb->destructor = xsk_destruct_skb;
 258
 259                 err = dev_direct_xmit(skb, xs->queue_id);
 260                 xskq_discard_desc(xs->tx);
 261                 /* Ignore NET_XMIT_CN as packet might have been sent */
 262                 if (err == NET_XMIT_DROP || err == NETDEV_TX_BUSY) {
 263                         /* SKB completed but not sent */
 264                         err = -EBUSY;
 265                         goto out;
 266                 }
 267
 268                 sent_frame = true;
 269         }
 270
 271 out:
 272         if (sent_frame)
 273                 sk->sk_write_space(sk);
 274
 275         mutex_unlock(&xs->mutex);
 276         return err;
 277 }
 278
 279 static int xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len)
 280 {
 281         bool need_wait = !(m->msg_flags & MSG_DONTWAIT);
 282         struct sock *sk = sock->sk;
 283         struct xdp_sock *xs = xdp_sk(sk);
 284
 285         if (unlikely(!xs->dev))
 286                 return -ENXIO;
 287         if (unlikely(!(xs->dev->flags & IFF_UP)))
 288                 return -ENETDOWN;
 289         if (unlikely(!xs->tx))
 290                 return -ENOBUFS;
 291         if (need_wait)
 292                 return -EOPNOTSUPP;
 293
 294         return (xs->zc) ? xsk_zc_xmit(sk) : xsk_generic_xmit(sk, m, total_len);
 295 }
 296
 297 static unsigned int xsk_poll(struct file *file, struct socket *sock,
 298                              struct poll_table_struct *wait)
 299 {
 300         unsigned int mask = datagram_poll(file, sock, wait);
 301         struct sock *sk = sock->sk;
 302         struct xdp_sock *xs = xdp_sk(sk);
 303
 304         if (xs->rx && !xskq_empty_desc(xs->rx))
 305                 mask |= POLLIN | POLLRDNORM;
 306         if (xs->tx && !xskq_full_desc(xs->tx))
 307                 mask |= POLLOUT | POLLWRNORM;
 308
 309         return mask;
 310 }
 311
 312 static int xsk_init_queue(u32 entries, struct xsk_queue **queue,
 313                           bool umem_queue)
 314 {
 315         struct xsk_queue *q;
 316
 317         if (entries == 0 || *queue || !is_power_of_2(entries))
 318                 return -EINVAL;
 319
 320         q = xskq_create(entries, umem_queue);
 321         if (!q)
 322                 return -ENOMEM;
 323
 324         /* Make sure queue is ready before it can be seen by others */
 325         smp_wmb();
 326         *queue = q;
 327         return 0;
 328 }
 329
 330 static int xsk_release(struct socket *sock)
 331 {
 332         struct sock *sk = sock->sk;
 333         struct xdp_sock *xs = xdp_sk(sk);
 334         struct net *net;
 335
 336         if (!sk)
 337                 return 0;
 338
 339         net = sock_net(sk);
 340
 341         local_bh_disable();
 342         sock_prot_inuse_add(net, sk->sk_prot, -1);
 343         local_bh_enable();
 344
 345         if (xs->dev) {
 346                 /* Wait for driver to stop using the xdp socket. */
 347                 synchronize_net();
 348                 dev_put(xs->dev);
 349                 xs->dev = NULL;
 350         }
 351
 352         sock_orphan(sk);
 353         sock->sk = NULL;
 354
 355         sk_refcnt_debug_release(sk);
 356         sock_put(sk);
 357
 358         return 0;
 359 }
 360
 361 static struct socket *xsk_lookup_xsk_from_fd(int fd)
 362 {
 363         struct socket *sock;
 364         int err;
 365
 366         sock = sockfd_lookup(fd, &err);
 367         if (!sock)
 368                 return ERR_PTR(-ENOTSOCK);
 369
 370         if (sock->sk->sk_family != PF_XDP) {
 371                 sockfd_put(sock);
 372                 return ERR_PTR(-ENOPROTOOPT);
 373         }
 374
 375         return sock;
 376 }
 377
 378 static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
 379 {
 380         struct sockaddr_xdp *sxdp = (struct sockaddr_xdp *)addr;
 381         struct sock *sk = sock->sk;
 382         struct xdp_sock *xs = xdp_sk(sk);
 383         struct net_device *dev;
 384         u32 flags, qid;
 385         int err = 0;
 386
 387         if (addr_len < sizeof(struct sockaddr_xdp))
 388                 return -EINVAL;
 389         if (sxdp->sxdp_family != AF_XDP)
 390                 return -EINVAL;
 391
 392         mutex_lock(&xs->mutex);
 393         if (xs->dev) {
 394                 err = -EBUSY;
 395                 goto out_release;
 396         }
 397
 398         dev = dev_get_by_index(sock_net(sk), sxdp->sxdp_ifindex);
 399         if (!dev) {
 400                 err = -ENODEV;
 401                 goto out_release;
 402         }
 403
 404         if (!xs->rx && !xs->tx) {
 405                 err = -EINVAL;
 406                 goto out_unlock;
 407         }
 408
 409         qid = sxdp->sxdp_queue_id;
 410
 411         if ((xs->rx && qid >= dev->real_num_rx_queues) ||
 412             (xs->tx && qid >= dev->real_num_tx_queues)) {
 413                 err = -EINVAL;
 414                 goto out_unlock;
 415         }
 416
 417         flags = sxdp->sxdp_flags;
 418
 419         if (flags & XDP_SHARED_UMEM) {
 420                 struct xdp_sock *umem_xs;
 421                 struct socket *sock;
 422
 423                 if ((flags & XDP_COPY) || (flags & XDP_ZEROCOPY)) {
 424                         /* Cannot specify flags for shared sockets. */
 425                         err = -EINVAL;
 426                         goto out_unlock;
 427                 }
 428
 429                 if (xs->umem) {
 430                         /* We have already our own. */
 431                         err = -EINVAL;
 432                         goto out_unlock;
 433                 }
 434
 435                 sock = xsk_lookup_xsk_from_fd(sxdp->sxdp_shared_umem_fd);
 436                 if (IS_ERR(sock)) {
 437                         err = PTR_ERR(sock);
 438                         goto out_unlock;
 439                 }
 440
 441                 umem_xs = xdp_sk(sock->sk);
 442                 if (!umem_xs->umem) {
 443                         /* No umem to inherit. */
 444                         err = -EBADF;
 445                         sockfd_put(sock);
 446                         goto out_unlock;
 447                 } else if (umem_xs->dev != dev || umem_xs->queue_id != qid) {
 448                         err = -EINVAL;
 449                         sockfd_put(sock);
 450                         goto out_unlock;
 451                 }
 452
 453                 xdp_get_umem(umem_xs->umem);
 454                 xs->umem = umem_xs->umem;
 455                 sockfd_put(sock);
 456         } else if (!xs->umem || !xdp_umem_validate_queues(xs->umem)) {
 457                 err = -EINVAL;
 458                 goto out_unlock;
 459         } else {
 460                 /* This xsk has its own umem. */
 461                 xskq_set_umem(xs->umem->fq, &xs->umem->props);
 462                 xskq_set_umem(xs->umem->cq, &xs->umem->props);
 463
 464                 err = xdp_umem_assign_dev(xs->umem, dev, qid, flags);
 465                 if (err)
 466                         goto out_unlock;
 467         }
 468
 469         xs->dev = dev;
 470         xs->zc = xs->umem->zc;
 471         xs->queue_id = qid;
 472         xskq_set_umem(xs->rx, &xs->umem->props);
 473         xskq_set_umem(xs->tx, &xs->umem->props);
 474         xdp_add_sk_umem(xs->umem, xs);
 475
 476 out_unlock:
 477         if (err)
 478                 dev_put(dev);
 479 out_release:
 480         mutex_unlock(&xs->mutex);
 481         return err;
 482 }
 483
 484 static int xsk_setsockopt(struct socket *sock, int level, int optname,
 485                           char __user *optval, unsigned int optlen)
 486 {
 487         struct sock *sk = sock->sk;
 488         struct xdp_sock *xs = xdp_sk(sk);
 489         int err;
 490
 491         if (level != SOL_XDP)
 492                 return -ENOPROTOOPT;
 493
 494         switch (optname) {
 495         case XDP_RX_RING:
 496         case XDP_TX_RING:
 497         {
 498                 struct xsk_queue **q;
 499                 int entries;
 500
 501                 if (optlen < sizeof(entries))
 502                         return -EINVAL;
 503                 if (copy_from_user(&entries, optval, sizeof(entries)))
 504                         return -EFAULT;
 505
 506                 mutex_lock(&xs->mutex);
 507                 q = (optname == XDP_TX_RING) ? &xs->tx : &xs->rx;
 508                 err = xsk_init_queue(entries, q, false);
 509                 mutex_unlock(&xs->mutex);
 510                 return err;
 511         }
 512         case XDP_UMEM_REG:
 513         {
 514                 struct xdp_umem_reg mr;
 515                 struct xdp_umem *umem;
 516
 517                 if (copy_from_user(&mr, optval, sizeof(mr)))
 518                         return -EFAULT;
 519
 520                 mutex_lock(&xs->mutex);
 521                 if (xs->umem) {
 522                         mutex_unlock(&xs->mutex);
 523                         return -EBUSY;
 524                 }
 525
 526                 umem = xdp_umem_create(&mr);
 527                 if (IS_ERR(umem)) {
 528                         mutex_unlock(&xs->mutex);
 529                         return PTR_ERR(umem);
 530                 }
 531
 532                 /* Make sure umem is ready before it can be seen by others */
 533                 smp_wmb();
 534                 xs->umem = umem;
 535                 mutex_unlock(&xs->mutex);
 536                 return 0;
 537         }
 538         case XDP_UMEM_FILL_RING:
 539         case XDP_UMEM_COMPLETION_RING:
 540         {
 541                 struct xsk_queue **q;
 542                 int entries;
 543
 544                 if (copy_from_user(&entries, optval, sizeof(entries)))
 545                         return -EFAULT;
 546
 547                 mutex_lock(&xs->mutex);
 548                 if (!xs->umem) {
 549                         mutex_unlock(&xs->mutex);
 550                         return -EINVAL;
 551                 }
 552
 553                 q = (optname == XDP_UMEM_FILL_RING) ? &xs->umem->fq :
 554                         &xs->umem->cq;
 555                 err = xsk_init_queue(entries, q, true);
 556                 mutex_unlock(&xs->mutex);
 557                 return err;
 558         }
 559         default:
 560                 break;
 561         }
 562
 563         return -ENOPROTOOPT;
 564 }
 565
 566 static int xsk_getsockopt(struct socket *sock, int level, int optname,
 567                           char __user *optval, int __user *optlen)
 568 {
 569         struct sock *sk = sock->sk;
 570         struct xdp_sock *xs = xdp_sk(sk);
 571         int len;
 572
 573         if (level != SOL_XDP)
 574                 return -ENOPROTOOPT;
 575
 576         if (get_user(len, optlen))
 577                 return -EFAULT;
 578         if (len < 0)
 579                 return -EINVAL;
 580
 581         switch (optname) {
 582         case XDP_STATISTICS:
 583         {
 584                 struct xdp_statistics stats;
 585
 586                 if (len < sizeof(stats))
 587                         return -EINVAL;
 588
 589                 mutex_lock(&xs->mutex);
 590                 stats.rx_dropped = xs->rx_dropped;
 591                 stats.rx_invalid_descs = xskq_nb_invalid_descs(xs->rx);
 592                 stats.tx_invalid_descs = xskq_nb_invalid_descs(xs->tx);
 593                 mutex_unlock(&xs->mutex);
 594
 595                 if (copy_to_user(optval, &stats, sizeof(stats)))
 596                         return -EFAULT;
 597                 if (put_user(sizeof(stats), optlen))
 598                         return -EFAULT;
 599
 600                 return 0;
 601         }
 602         case XDP_MMAP_OFFSETS:
 603         {
 604                 struct xdp_mmap_offsets off;
 605
 606                 if (len < sizeof(off))
 607                         return -EINVAL;
 608
 609                 off.rx.producer = offsetof(struct xdp_rxtx_ring, ptrs.producer);
 610                 off.rx.consumer = offsetof(struct xdp_rxtx_ring, ptrs.consumer);
 611                 off.rx.desc     = offsetof(struct xdp_rxtx_ring, desc);
 612                 off.tx.producer = offsetof(struct xdp_rxtx_ring, ptrs.producer);
 613                 off.tx.consumer = offsetof(struct xdp_rxtx_ring, ptrs.consumer);
 614                 off.tx.desc     = offsetof(struct xdp_rxtx_ring, desc);
 615
 616                 off.fr.producer = offsetof(struct xdp_umem_ring, ptrs.producer);
 617                 off.fr.consumer = offsetof(struct xdp_umem_ring, ptrs.consumer);
 618                 off.fr.desc     = offsetof(struct xdp_umem_ring, desc);
 619                 off.cr.producer = offsetof(struct xdp_umem_ring, ptrs.producer);
 620                 off.cr.consumer = offsetof(struct xdp_umem_ring, ptrs.consumer);
 621                 off.cr.desc     = offsetof(struct xdp_umem_ring, desc);
 622
 623                 len = sizeof(off);
 624                 if (copy_to_user(optval, &off, len))
 625                         return -EFAULT;
 626                 if (put_user(len, optlen))
 627                         return -EFAULT;
 628
 629                 return 0;
 630         }
 631         default:
 632                 break;
 633         }
 634
 635         return -EOPNOTSUPP;
 636 }
 637
 638 static int xsk_mmap(struct file *file, struct socket *sock,
 639                     struct vm_area_struct *vma)
 640 {
 641         loff_t offset = (loff_t)vma->vm_pgoff << PAGE_SHIFT;
 642         unsigned long size = vma->vm_end - vma->vm_start;
 643         struct xdp_sock *xs = xdp_sk(sock->sk);
 644         struct xsk_queue *q = NULL;
 645         struct xdp_umem *umem;
 646         unsigned long pfn;
 647         struct page *qpg;
 648
 649         if (offset == XDP_PGOFF_RX_RING) {
 650                 q = READ_ONCE(xs->rx);
 651         } else if (offset == XDP_PGOFF_TX_RING) {
 652                 q = READ_ONCE(xs->tx);
 653         } else {
 654                 umem = READ_ONCE(xs->umem);
 655                 if (!umem)
 656                         return -EINVAL;
 657
 658                 if (offset == XDP_UMEM_PGOFF_FILL_RING)
 659                         q = READ_ONCE(umem->fq);
 660                 else if (offset == XDP_UMEM_PGOFF_COMPLETION_RING)
 661                         q = READ_ONCE(umem->cq);
 662         }
 663
 664         if (!q)
 665                 return -EINVAL;
 666
 667         qpg = virt_to_head_page(q->ring);
 668         if (size > (PAGE_SIZE << compound_order(qpg)))
 669                 return -EINVAL;
 670
 671         pfn = virt_to_phys(q->ring) >> PAGE_SHIFT;
 672         return remap_pfn_range(vma, vma->vm_start, pfn,
 673                                size, vma->vm_page_prot);
 674 }
 675
 676 static struct proto xsk_proto = {
 677         .name =         "XDP",
 678         .owner =        THIS_MODULE,
 679         .obj_size =     sizeof(struct xdp_sock),
 680 };
 681
 682 static const struct proto_ops xsk_proto_ops = {
 683         .family         = PF_XDP,
 684         .owner          = THIS_MODULE,
 685         .release        = xsk_release,
 686         .bind           = xsk_bind,
 687         .connect        = sock_no_connect,
 688         .socketpair     = sock_no_socketpair,
 689         .accept         = sock_no_accept,
 690         .getname        = sock_no_getname,
 691         .poll           = xsk_poll,
 692         .ioctl          = sock_no_ioctl,
 693         .listen         = sock_no_listen,
 694         .shutdown       = sock_no_shutdown,
 695         .setsockopt     = xsk_setsockopt,
 696         .getsockopt     = xsk_getsockopt,
 697         .sendmsg        = xsk_sendmsg,
 698         .recvmsg        = sock_no_recvmsg,
 699         .mmap           = xsk_mmap,
 700         .sendpage       = sock_no_sendpage,
 701 };
 702
 703 static void xsk_destruct(struct sock *sk)
 704 {
 705         struct xdp_sock *xs = xdp_sk(sk);
 706
 707         if (!sock_flag(sk, SOCK_DEAD))
 708                 return;
 709
 710         xskq_destroy(xs->rx);
 711         xskq_destroy(xs->tx);
 712         xdp_del_sk_umem(xs->umem, xs);
 713         xdp_put_umem(xs->umem);
 714
 715         sk_refcnt_debug_dec(sk);
 716 }
 717
 718 static int xsk_create(struct net *net, struct socket *sock, int protocol,
 719                       int kern)
 720 {
 721         struct sock *sk;
 722         struct xdp_sock *xs;
 723
 724         if (!ns_capable(net->user_ns, CAP_NET_RAW))
 725                 return -EPERM;
 726         if (sock->type != SOCK_RAW)
 727                 return -ESOCKTNOSUPPORT;
 728
 729         if (protocol)
 730                 return -EPROTONOSUPPORT;
 731
 732         sock->state = SS_UNCONNECTED;
 733
 734         sk = sk_alloc(net, PF_XDP, GFP_KERNEL, &xsk_proto, kern);
 735         if (!sk)
 736                 return -ENOBUFS;
 737
 738         sock->ops = &xsk_proto_ops;
 739
 740         sock_init_data(sock, sk);
 741
 742         sk->sk_family = PF_XDP;
 743
 744         sk->sk_destruct = xsk_destruct;
 745         sk_refcnt_debug_inc(sk);
 746
 747         xs = xdp_sk(sk);
 748         mutex_init(&xs->mutex);
 749         spin_lock_init(&xs->tx_completion_lock);
 750
 751         local_bh_disable();
 752         sock_prot_inuse_add(net, &xsk_proto, 1);
 753         local_bh_enable();
 754
 755         return 0;
 756 }
 757
 758 static const struct net_proto_family xsk_family_ops = {
 759         .family = PF_XDP,
 760         .create = xsk_create,
 761         .owner  = THIS_MODULE,
 762 };
 763
 764 static int __init xsk_init(void)
 765 {
 766         int err;
 767
 768         err = proto_register(&xsk_proto, 0 /* no slab */);
 769         if (err)
 770                 goto out;
 771
 772         err = sock_register(&xsk_family_ops);
 773         if (err)
 774                 goto out_proto;
 775
 776         return 0;
 777
 778 out_proto:
 779         proto_unregister(&xsk_proto);
 780 out:
 781         return err;
 782 }
 783
 784 fs_initcall(xsk_init);