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