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 ***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 **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->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); 1483