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 -ENOMEM; 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 -ENXIO; 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, u32 max_entries) 347 { 348 struct xdp_desc *descs = pool->tx_descs; 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, u32 max_entries) 359 { 360 struct xdp_sock *xs; 361 u32 nb_pkts; 362 363 rcu_read_lock(); 364 if (!list_is_singular(&pool->xsk_tx_list)) { 365 /* Fallback to the non-batched version */ 366 rcu_read_unlock(); 367 return xsk_tx_peek_release_fallback(pool, max_entries); 368 } 369 370 xs = list_first_or_null_rcu(&pool->xsk_tx_list, struct xdp_sock, tx_list); 371 if (!xs) { 372 nb_pkts = 0; 373 goto out; 374 } 375 376 max_entries = xskq_cons_nb_entries(xs->tx, max_entries); 377 nb_pkts = xskq_cons_read_desc_batch(xs->tx, 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, pool->tx_descs, nb_pkts); 390 if (!nb_pkts) 391 goto out; 392 393 xskq_cons_release_n(xs->tx, max_entries); 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; 406 407 return dev->netdev_ops->ndo_xsk_wakeup(dev, xs->queue_id, flags); 408 } 409 410 static void xsk_destruct_skb(struct sk_buff *skb) 411 { 412 u64 addr = (u64)(long)skb_shinfo(skb)->destructor_arg; 413 struct xdp_sock *xs = xdp_sk(skb->sk); 414 unsigned long flags; 415 416 spin_lock_irqsave(&xs->pool->cq_lock, flags); 417 xskq_prod_submit_addr(xs->pool->cq, addr); 418 spin_unlock_irqrestore(&xs->pool->cq_lock, flags); 419 420 sock_wfree(skb); 421 } 422 423 static struct sk_buff *xsk_build_skb_zerocopy(struct xdp_sock *xs, 424 struct xdp_desc *desc) 425 { 426 struct xsk_buff_pool *pool = xs->pool; 427 u32 hr, len, ts, offset, copy, copied; 428 struct sk_buff *skb; 429 struct page *page; 430 void *buffer; 431 int err, i; 432 u64 addr; 433 434 hr = max(NET_SKB_PAD, L1_CACHE_ALIGN(xs->dev->needed_headroom)); 435 436 skb = sock_alloc_send_skb(&xs->sk, hr, 1, &err); 437 if (unlikely(!skb)) 438 return ERR_PTR(err); 439 440 skb_reserve(skb, hr); 441 442 addr = desc->addr; 443 len = desc->len; 444 ts = pool->unaligned ? len : pool->chunk_size; 445 446 buffer = xsk_buff_raw_get_data(pool, addr); 447 offset = offset_in_page(buffer); 448 addr = buffer - pool->addrs; 449 450 for (copied = 0, i = 0; copied < len; i++) { 451 page = pool->umem->pgs[addr >> PAGE_SHIFT]; 452 get_page(page); 453 454 copy = min_t(u32, PAGE_SIZE - offset, len - copied); 455 skb_fill_page_desc(skb, i, page, offset, copy); 456 457 copied += copy; 458 addr += copy; 459 offset = 0; 460 } 461 462 skb->len += len; 463 skb->data_len += len; 464 skb->truesize += ts; 465 466 refcount_add(ts, &xs->sk.sk_wmem_alloc); 467 468 return skb; 469 } 470 471 static struct sk_buff *xsk_build_skb(struct xdp_sock *xs, 472 struct xdp_desc *desc) 473 { 474 struct net_device *dev = xs->dev; 475 struct sk_buff *skb; 476 477 if (dev->priv_flags & IFF_TX_SKB_NO_LINEAR) { 478 skb = xsk_build_skb_zerocopy(xs, desc); 479 if (IS_ERR(skb)) 480 return skb; 481 } else { 482 u32 hr, tr, len; 483 void *buffer; 484 int err; 485 486 hr = max(NET_SKB_PAD, L1_CACHE_ALIGN(dev->needed_headroom)); 487 tr = dev->needed_tailroom; 488 len = desc->len; 489 490 skb = sock_alloc_send_skb(&xs->sk, hr + len + tr, 1, &err); 491 if (unlikely(!skb)) 492 return ERR_PTR(err); 493 494 skb_reserve(skb, hr); 495 skb_put(skb, len); 496 497 buffer = xsk_buff_raw_get_data(xs->pool, desc->addr); 498 err = skb_store_bits(skb, 0, buffer, len); 499 if (unlikely(err)) { 500 kfree_skb(skb); 501 return ERR_PTR(err); 502 } 503 } 504 505 skb->dev = dev; 506 skb->priority = xs->sk.sk_priority; 507 skb->mark = xs->sk.sk_mark; 508 skb_shinfo(skb)->destructor_arg = (void *)(long)desc->addr; 509 skb->destructor = xsk_destruct_skb; 510 511 return skb; 512 } 513 514 static int xsk_generic_xmit(struct sock *sk) 515 { 516 struct xdp_sock *xs = xdp_sk(sk); 517 u32 max_batch = TX_BATCH_SIZE; 518 bool sent_frame = false; 519 struct xdp_desc desc; 520 struct sk_buff *skb; 521 unsigned long flags; 522 int err = 0; 523 524 mutex_lock(&xs->mutex); 525 526 /* Since we dropped the RCU read lock, the socket state might have changed. */ 527 if (unlikely(!xsk_is_bound(xs))) { 528 err = -ENXIO; 529 goto out; 530 } 531 532 if (xs->queue_id >= xs->dev->real_num_tx_queues) 533 goto out; 534 535 while (xskq_cons_peek_desc(xs->tx, &desc, xs->pool)) { 536 if (max_batch-- == 0) { 537 err = -EAGAIN; 538 goto out; 539 } 540 541 /* This is the backpressure mechanism for the Tx path. 542 * Reserve space in the completion queue and only proceed 543 * if there is space in it. This avoids having to implement 544 * any buffering in the Tx path. 545 */ 546 spin_lock_irqsave(&xs->pool->cq_lock, flags); 547 if (xskq_prod_reserve(xs->pool->cq)) { 548 spin_unlock_irqrestore(&xs->pool->cq_lock, flags); 549 goto out; 550 } 551 spin_unlock_irqrestore(&xs->pool->cq_lock, flags); 552 553 skb = xsk_build_skb(xs, &desc); 554 if (IS_ERR(skb)) { 555 err = PTR_ERR(skb); 556 spin_lock_irqsave(&xs->pool->cq_lock, flags); 557 xskq_prod_cancel(xs->pool->cq); 558 spin_unlock_irqrestore(&xs->pool->cq_lock, flags); 559 goto out; 560 } 561 562 err = __dev_direct_xmit(skb, xs->queue_id); 563 if (err == NETDEV_TX_BUSY) { 564 /* Tell user-space to retry the send */ 565 skb->destructor = sock_wfree; 566 spin_lock_irqsave(&xs->pool->cq_lock, flags); 567 xskq_prod_cancel(xs->pool->cq); 568 spin_unlock_irqrestore(&xs->pool->cq_lock, flags); 569 /* Free skb without triggering the perf drop trace */ 570 consume_skb(skb); 571 err = -EAGAIN; 572 goto out; 573 } 574 575 xskq_cons_release(xs->tx); 576 /* Ignore NET_XMIT_CN as packet might have been sent */ 577 if (err == NET_XMIT_DROP) { 578 /* SKB completed but not sent */ 579 err = -EBUSY; 580 goto out; 581 } 582 583 sent_frame = true; 584 } 585 586 xs->tx->queue_empty_descs++; 587 588 out: 589 if (sent_frame) 590 if (xsk_tx_writeable(xs)) 591 sk->sk_write_space(sk); 592 593 mutex_unlock(&xs->mutex); 594 return err; 595 } 596 597 static int xsk_xmit(struct sock *sk) 598 { 599 struct xdp_sock *xs = xdp_sk(sk); 600 int ret; 601 602 if (unlikely(!(xs->dev->flags & IFF_UP))) 603 return -ENETDOWN; 604 if (unlikely(!xs->tx)) 605 return -ENOBUFS; 606 607 if (xs->zc) 608 return xsk_wakeup(xs, XDP_WAKEUP_TX); 609 610 /* Drop the RCU lock since the SKB path might sleep. */ 611 rcu_read_unlock(); 612 ret = xsk_generic_xmit(sk); 613 /* Reaquire RCU lock before going into common code. */ 614 rcu_read_lock(); 615 616 return ret; 617 } 618 619 static bool xsk_no_wakeup(struct sock *sk) 620 { 621 #ifdef CONFIG_NET_RX_BUSY_POLL 622 /* Prefer busy-polling, skip the wakeup. */ 623 return READ_ONCE(sk->sk_prefer_busy_poll) && READ_ONCE(sk->sk_ll_usec) && 624 READ_ONCE(sk->sk_napi_id) >= MIN_NAPI_ID; 625 #else 626 return false; 627 #endif 628 } 629 630 static int __xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len) 631 { 632 bool need_wait = !(m->msg_flags & MSG_DONTWAIT); 633 struct sock *sk = sock->sk; 634 struct xdp_sock *xs = xdp_sk(sk); 635 struct xsk_buff_pool *pool; 636 637 if (unlikely(!xsk_is_bound(xs))) 638 return -ENXIO; 639 if (unlikely(need_wait)) 640 return -EOPNOTSUPP; 641 642 if (sk_can_busy_loop(sk)) 643 sk_busy_loop(sk, 1); /* only support non-blocking sockets */ 644 645 if (xs->zc && xsk_no_wakeup(sk)) 646 return 0; 647 648 pool = xs->pool; 649 if (pool->cached_need_wakeup & XDP_WAKEUP_TX) 650 return xsk_xmit(sk); 651 return 0; 652 } 653 654 static int xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len) 655 { 656 int ret; 657 658 rcu_read_lock(); 659 ret = __xsk_sendmsg(sock, m, total_len); 660 rcu_read_unlock(); 661 662 return ret; 663 } 664 665 static int __xsk_recvmsg(struct socket *sock, struct msghdr *m, size_t len, int flags) 666 { 667 bool need_wait = !(flags & MSG_DONTWAIT); 668 struct sock *sk = sock->sk; 669 struct xdp_sock *xs = xdp_sk(sk); 670 671 if (unlikely(!xsk_is_bound(xs))) 672 return -ENXIO; 673 if (unlikely(!(xs->dev->flags & IFF_UP))) 674 return -ENETDOWN; 675 if (unlikely(!xs->rx)) 676 return -ENOBUFS; 677 if (unlikely(need_wait)) 678 return -EOPNOTSUPP; 679 680 if (sk_can_busy_loop(sk)) 681 sk_busy_loop(sk, 1); /* only support non-blocking sockets */ 682 683 if (xsk_no_wakeup(sk)) 684 return 0; 685 686 if (xs->pool->cached_need_wakeup & XDP_WAKEUP_RX && xs->zc) 687 return xsk_wakeup(xs, XDP_WAKEUP_RX); 688 return 0; 689 } 690 691 static int xsk_recvmsg(struct socket *sock, struct msghdr *m, size_t len, int flags) 692 { 693 int ret; 694 695 rcu_read_lock(); 696 ret = __xsk_recvmsg(sock, m, len, flags); 697 rcu_read_unlock(); 698 699 return ret; 700 } 701 702 static __poll_t xsk_poll(struct file *file, struct socket *sock, 703 struct poll_table_struct *wait) 704 { 705 __poll_t mask = 0; 706 struct sock *sk = sock->sk; 707 struct xdp_sock *xs = xdp_sk(sk); 708 struct xsk_buff_pool *pool; 709 710 sock_poll_wait(file, sock, wait); 711 712 rcu_read_lock(); 713 if (unlikely(!xsk_is_bound(xs))) { 714 rcu_read_unlock(); 715 return mask; 716 } 717 718 pool = xs->pool; 719 720 if (pool->cached_need_wakeup) { 721 if (xs->zc) 722 xsk_wakeup(xs, pool->cached_need_wakeup); 723 else 724 /* Poll needs to drive Tx also in copy mode */ 725 xsk_xmit(sk); 726 } 727 728 if (xs->rx && !xskq_prod_is_empty(xs->rx)) 729 mask |= EPOLLIN | EPOLLRDNORM; 730 if (xs->tx && xsk_tx_writeable(xs)) 731 mask |= EPOLLOUT | EPOLLWRNORM; 732 733 rcu_read_unlock(); 734 return mask; 735 } 736 737 static int xsk_init_queue(u32 entries, struct xsk_queue **queue, 738 bool umem_queue) 739 { 740 struct xsk_queue *q; 741 742 if (entries == 0 || *queue || !is_power_of_2(entries)) 743 return -EINVAL; 744 745 q = xskq_create(entries, umem_queue); 746 if (!q) 747 return -ENOMEM; 748 749 /* Make sure queue is ready before it can be seen by others */ 750 smp_wmb(); 751 WRITE_ONCE(*queue, q); 752 return 0; 753 } 754 755 static void xsk_unbind_dev(struct xdp_sock *xs) 756 { 757 struct net_device *dev = xs->dev; 758 759 if (xs->state != XSK_BOUND) 760 return; 761 WRITE_ONCE(xs->state, XSK_UNBOUND); 762 763 /* Wait for driver to stop using the xdp socket. */ 764 xp_del_xsk(xs->pool, xs); 765 synchronize_net(); 766 dev_put(dev); 767 } 768 769 static struct xsk_map *xsk_get_map_list_entry(struct xdp_sock *xs, 770 struct xdp_sock __rcu ***map_entry) 771 { 772 struct xsk_map *map = NULL; 773 struct xsk_map_node *node; 774 775 *map_entry = NULL; 776 777 spin_lock_bh(&xs->map_list_lock); 778 node = list_first_entry_or_null(&xs->map_list, struct xsk_map_node, 779 node); 780 if (node) { 781 bpf_map_inc(&node->map->map); 782 map = node->map; 783 *map_entry = node->map_entry; 784 } 785 spin_unlock_bh(&xs->map_list_lock); 786 return map; 787 } 788 789 static void xsk_delete_from_maps(struct xdp_sock *xs) 790 { 791 /* This function removes the current XDP socket from all the 792 * maps it resides in. We need to take extra care here, due to 793 * the two locks involved. Each map has a lock synchronizing 794 * updates to the entries, and each socket has a lock that 795 * synchronizes access to the list of maps (map_list). For 796 * deadlock avoidance the locks need to be taken in the order 797 * "map lock"->"socket map list lock". We start off by 798 * accessing the socket map list, and take a reference to the 799 * map to guarantee existence between the 800 * xsk_get_map_list_entry() and xsk_map_try_sock_delete() 801 * calls. Then we ask the map to remove the socket, which 802 * tries to remove the socket from the map. Note that there 803 * might be updates to the map between 804 * xsk_get_map_list_entry() and xsk_map_try_sock_delete(). 805 */ 806 struct xdp_sock __rcu **map_entry = NULL; 807 struct xsk_map *map; 808 809 while ((map = xsk_get_map_list_entry(xs, &map_entry))) { 810 xsk_map_try_sock_delete(map, xs, map_entry); 811 bpf_map_put(&map->map); 812 } 813 } 814 815 static int xsk_release(struct socket *sock) 816 { 817 struct sock *sk = sock->sk; 818 struct xdp_sock *xs = xdp_sk(sk); 819 struct net *net; 820 821 if (!sk) 822 return 0; 823 824 net = sock_net(sk); 825 826 mutex_lock(&net->xdp.lock); 827 sk_del_node_init_rcu(sk); 828 mutex_unlock(&net->xdp.lock); 829 830 sock_prot_inuse_add(net, sk->sk_prot, -1); 831 832 xsk_delete_from_maps(xs); 833 mutex_lock(&xs->mutex); 834 xsk_unbind_dev(xs); 835 mutex_unlock(&xs->mutex); 836 837 xskq_destroy(xs->rx); 838 xskq_destroy(xs->tx); 839 xskq_destroy(xs->fq_tmp); 840 xskq_destroy(xs->cq_tmp); 841 842 sock_orphan(sk); 843 sock->sk = NULL; 844 845 sk_refcnt_debug_release(sk); 846 sock_put(sk); 847 848 return 0; 849 } 850 851 static struct socket *xsk_lookup_xsk_from_fd(int fd) 852 { 853 struct socket *sock; 854 int err; 855 856 sock = sockfd_lookup(fd, &err); 857 if (!sock) 858 return ERR_PTR(-ENOTSOCK); 859 860 if (sock->sk->sk_family != PF_XDP) { 861 sockfd_put(sock); 862 return ERR_PTR(-ENOPROTOOPT); 863 } 864 865 return sock; 866 } 867 868 static bool xsk_validate_queues(struct xdp_sock *xs) 869 { 870 return xs->fq_tmp && xs->cq_tmp; 871 } 872 873 static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len) 874 { 875 struct sockaddr_xdp *sxdp = (struct sockaddr_xdp *)addr; 876 struct sock *sk = sock->sk; 877 struct xdp_sock *xs = xdp_sk(sk); 878 struct net_device *dev; 879 u32 flags, qid; 880 int err = 0; 881 882 if (addr_len < sizeof(struct sockaddr_xdp)) 883 return -EINVAL; 884 if (sxdp->sxdp_family != AF_XDP) 885 return -EINVAL; 886 887 flags = sxdp->sxdp_flags; 888 if (flags & ~(XDP_SHARED_UMEM | XDP_COPY | XDP_ZEROCOPY | 889 XDP_USE_NEED_WAKEUP)) 890 return -EINVAL; 891 892 rtnl_lock(); 893 mutex_lock(&xs->mutex); 894 if (xs->state != XSK_READY) { 895 err = -EBUSY; 896 goto out_release; 897 } 898 899 dev = dev_get_by_index(sock_net(sk), sxdp->sxdp_ifindex); 900 if (!dev) { 901 err = -ENODEV; 902 goto out_release; 903 } 904 905 if (!xs->rx && !xs->tx) { 906 err = -EINVAL; 907 goto out_unlock; 908 } 909 910 qid = sxdp->sxdp_queue_id; 911 912 if (flags & XDP_SHARED_UMEM) { 913 struct xdp_sock *umem_xs; 914 struct socket *sock; 915 916 if ((flags & XDP_COPY) || (flags & XDP_ZEROCOPY) || 917 (flags & XDP_USE_NEED_WAKEUP)) { 918 /* Cannot specify flags for shared sockets. */ 919 err = -EINVAL; 920 goto out_unlock; 921 } 922 923 if (xs->umem) { 924 /* We have already our own. */ 925 err = -EINVAL; 926 goto out_unlock; 927 } 928 929 sock = xsk_lookup_xsk_from_fd(sxdp->sxdp_shared_umem_fd); 930 if (IS_ERR(sock)) { 931 err = PTR_ERR(sock); 932 goto out_unlock; 933 } 934 935 umem_xs = xdp_sk(sock->sk); 936 if (!xsk_is_bound(umem_xs)) { 937 err = -EBADF; 938 sockfd_put(sock); 939 goto out_unlock; 940 } 941 942 if (umem_xs->queue_id != qid || umem_xs->dev != dev) { 943 /* Share the umem with another socket on another qid 944 * and/or device. 945 */ 946 xs->pool = xp_create_and_assign_umem(xs, 947 umem_xs->umem); 948 if (!xs->pool) { 949 err = -ENOMEM; 950 sockfd_put(sock); 951 goto out_unlock; 952 } 953 954 err = xp_assign_dev_shared(xs->pool, umem_xs->umem, 955 dev, qid); 956 if (err) { 957 xp_destroy(xs->pool); 958 xs->pool = NULL; 959 sockfd_put(sock); 960 goto out_unlock; 961 } 962 } else { 963 /* Share the buffer pool with the other socket. */ 964 if (xs->fq_tmp || xs->cq_tmp) { 965 /* Do not allow setting your own fq or cq. */ 966 err = -EINVAL; 967 sockfd_put(sock); 968 goto out_unlock; 969 } 970 971 xp_get_pool(umem_xs->pool); 972 xs->pool = umem_xs->pool; 973 974 /* If underlying shared umem was created without Tx 975 * ring, allocate Tx descs array that Tx batching API 976 * utilizes 977 */ 978 if (xs->tx && !xs->pool->tx_descs) { 979 err = xp_alloc_tx_descs(xs->pool, xs); 980 if (err) { 981 xp_put_pool(xs->pool); 982 sockfd_put(sock); 983 goto out_unlock; 984 } 985 } 986 } 987 988 xdp_get_umem(umem_xs->umem); 989 WRITE_ONCE(xs->umem, umem_xs->umem); 990 sockfd_put(sock); 991 } else if (!xs->umem || !xsk_validate_queues(xs)) { 992 err = -EINVAL; 993 goto out_unlock; 994 } else { 995 /* This xsk has its own umem. */ 996 xs->pool = xp_create_and_assign_umem(xs, xs->umem); 997 if (!xs->pool) { 998 err = -ENOMEM; 999 goto out_unlock; 1000 } 1001 1002 err = xp_assign_dev(xs->pool, dev, qid, flags); 1003 if (err) { 1004 xp_destroy(xs->pool); 1005 xs->pool = NULL; 1006 goto out_unlock; 1007 } 1008 } 1009 1010 /* FQ and CQ are now owned by the buffer pool and cleaned up with it. */ 1011 xs->fq_tmp = NULL; 1012 xs->cq_tmp = NULL; 1013 1014 xs->dev = dev; 1015 xs->zc = xs->umem->zc; 1016 xs->queue_id = qid; 1017 xp_add_xsk(xs->pool, xs); 1018 1019 out_unlock: 1020 if (err) { 1021 dev_put(dev); 1022 } else { 1023 /* Matches smp_rmb() in bind() for shared umem 1024 * sockets, and xsk_is_bound(). 1025 */ 1026 smp_wmb(); 1027 WRITE_ONCE(xs->state, XSK_BOUND); 1028 } 1029 out_release: 1030 mutex_unlock(&xs->mutex); 1031 rtnl_unlock(); 1032 return err; 1033 } 1034 1035 struct xdp_umem_reg_v1 { 1036 __u64 addr; /* Start of packet data area */ 1037 __u64 len; /* Length of packet data area */ 1038 __u32 chunk_size; 1039 __u32 headroom; 1040 }; 1041 1042 static int xsk_setsockopt(struct socket *sock, int level, int optname, 1043 sockptr_t optval, unsigned int optlen) 1044 { 1045 struct sock *sk = sock->sk; 1046 struct xdp_sock *xs = xdp_sk(sk); 1047 int err; 1048 1049 if (level != SOL_XDP) 1050 return -ENOPROTOOPT; 1051 1052 switch (optname) { 1053 case XDP_RX_RING: 1054 case XDP_TX_RING: 1055 { 1056 struct xsk_queue **q; 1057 int entries; 1058 1059 if (optlen < sizeof(entries)) 1060 return -EINVAL; 1061 if (copy_from_sockptr(&entries, optval, sizeof(entries))) 1062 return -EFAULT; 1063 1064 mutex_lock(&xs->mutex); 1065 if (xs->state != XSK_READY) { 1066 mutex_unlock(&xs->mutex); 1067 return -EBUSY; 1068 } 1069 q = (optname == XDP_TX_RING) ? &xs->tx : &xs->rx; 1070 err = xsk_init_queue(entries, q, false); 1071 if (!err && optname == XDP_TX_RING) 1072 /* Tx needs to be explicitly woken up the first time */ 1073 xs->tx->ring->flags |= XDP_RING_NEED_WAKEUP; 1074 mutex_unlock(&xs->mutex); 1075 return err; 1076 } 1077 case XDP_UMEM_REG: 1078 { 1079 size_t mr_size = sizeof(struct xdp_umem_reg); 1080 struct xdp_umem_reg mr = {}; 1081 struct xdp_umem *umem; 1082 1083 if (optlen < sizeof(struct xdp_umem_reg_v1)) 1084 return -EINVAL; 1085 else if (optlen < sizeof(mr)) 1086 mr_size = sizeof(struct xdp_umem_reg_v1); 1087 1088 if (copy_from_sockptr(&mr, optval, mr_size)) 1089 return -EFAULT; 1090 1091 mutex_lock(&xs->mutex); 1092 if (xs->state != XSK_READY || xs->umem) { 1093 mutex_unlock(&xs->mutex); 1094 return -EBUSY; 1095 } 1096 1097 umem = xdp_umem_create(&mr); 1098 if (IS_ERR(umem)) { 1099 mutex_unlock(&xs->mutex); 1100 return PTR_ERR(umem); 1101 } 1102 1103 /* Make sure umem is ready before it can be seen by others */ 1104 smp_wmb(); 1105 WRITE_ONCE(xs->umem, umem); 1106 mutex_unlock(&xs->mutex); 1107 return 0; 1108 } 1109 case XDP_UMEM_FILL_RING: 1110 case XDP_UMEM_COMPLETION_RING: 1111 { 1112 struct xsk_queue **q; 1113 int entries; 1114 1115 if (copy_from_sockptr(&entries, optval, sizeof(entries))) 1116 return -EFAULT; 1117 1118 mutex_lock(&xs->mutex); 1119 if (xs->state != XSK_READY) { 1120 mutex_unlock(&xs->mutex); 1121 return -EBUSY; 1122 } 1123 1124 q = (optname == XDP_UMEM_FILL_RING) ? &xs->fq_tmp : 1125 &xs->cq_tmp; 1126 err = xsk_init_queue(entries, q, true); 1127 mutex_unlock(&xs->mutex); 1128 return err; 1129 } 1130 default: 1131 break; 1132 } 1133 1134 return -ENOPROTOOPT; 1135 } 1136 1137 static void xsk_enter_rxtx_offsets(struct xdp_ring_offset_v1 *ring) 1138 { 1139 ring->producer = offsetof(struct xdp_rxtx_ring, ptrs.producer); 1140 ring->consumer = offsetof(struct xdp_rxtx_ring, ptrs.consumer); 1141 ring->desc = offsetof(struct xdp_rxtx_ring, desc); 1142 } 1143 1144 static void xsk_enter_umem_offsets(struct xdp_ring_offset_v1 *ring) 1145 { 1146 ring->producer = offsetof(struct xdp_umem_ring, ptrs.producer); 1147 ring->consumer = offsetof(struct xdp_umem_ring, ptrs.consumer); 1148 ring->desc = offsetof(struct xdp_umem_ring, desc); 1149 } 1150 1151 struct xdp_statistics_v1 { 1152 __u64 rx_dropped; 1153 __u64 rx_invalid_descs; 1154 __u64 tx_invalid_descs; 1155 }; 1156 1157 static int xsk_getsockopt(struct socket *sock, int level, int optname, 1158 char __user *optval, int __user *optlen) 1159 { 1160 struct sock *sk = sock->sk; 1161 struct xdp_sock *xs = xdp_sk(sk); 1162 int len; 1163 1164 if (level != SOL_XDP) 1165 return -ENOPROTOOPT; 1166 1167 if (get_user(len, optlen)) 1168 return -EFAULT; 1169 if (len < 0) 1170 return -EINVAL; 1171 1172 switch (optname) { 1173 case XDP_STATISTICS: 1174 { 1175 struct xdp_statistics stats = {}; 1176 bool extra_stats = true; 1177 size_t stats_size; 1178 1179 if (len < sizeof(struct xdp_statistics_v1)) { 1180 return -EINVAL; 1181 } else if (len < sizeof(stats)) { 1182 extra_stats = false; 1183 stats_size = sizeof(struct xdp_statistics_v1); 1184 } else { 1185 stats_size = sizeof(stats); 1186 } 1187 1188 mutex_lock(&xs->mutex); 1189 stats.rx_dropped = xs->rx_dropped; 1190 if (extra_stats) { 1191 stats.rx_ring_full = xs->rx_queue_full; 1192 stats.rx_fill_ring_empty_descs = 1193 xs->pool ? xskq_nb_queue_empty_descs(xs->pool->fq) : 0; 1194 stats.tx_ring_empty_descs = xskq_nb_queue_empty_descs(xs->tx); 1195 } else { 1196 stats.rx_dropped += xs->rx_queue_full; 1197 } 1198 stats.rx_invalid_descs = xskq_nb_invalid_descs(xs->rx); 1199 stats.tx_invalid_descs = xskq_nb_invalid_descs(xs->tx); 1200 mutex_unlock(&xs->mutex); 1201 1202 if (copy_to_user(optval, &stats, stats_size)) 1203 return -EFAULT; 1204 if (put_user(stats_size, optlen)) 1205 return -EFAULT; 1206 1207 return 0; 1208 } 1209 case XDP_MMAP_OFFSETS: 1210 { 1211 struct xdp_mmap_offsets off; 1212 struct xdp_mmap_offsets_v1 off_v1; 1213 bool flags_supported = true; 1214 void *to_copy; 1215 1216 if (len < sizeof(off_v1)) 1217 return -EINVAL; 1218 else if (len < sizeof(off)) 1219 flags_supported = false; 1220 1221 if (flags_supported) { 1222 /* xdp_ring_offset is identical to xdp_ring_offset_v1 1223 * except for the flags field added to the end. 1224 */ 1225 xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *) 1226 &off.rx); 1227 xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *) 1228 &off.tx); 1229 xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *) 1230 &off.fr); 1231 xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *) 1232 &off.cr); 1233 off.rx.flags = offsetof(struct xdp_rxtx_ring, 1234 ptrs.flags); 1235 off.tx.flags = offsetof(struct xdp_rxtx_ring, 1236 ptrs.flags); 1237 off.fr.flags = offsetof(struct xdp_umem_ring, 1238 ptrs.flags); 1239 off.cr.flags = offsetof(struct xdp_umem_ring, 1240 ptrs.flags); 1241 1242 len = sizeof(off); 1243 to_copy = &off; 1244 } else { 1245 xsk_enter_rxtx_offsets(&off_v1.rx); 1246 xsk_enter_rxtx_offsets(&off_v1.tx); 1247 xsk_enter_umem_offsets(&off_v1.fr); 1248 xsk_enter_umem_offsets(&off_v1.cr); 1249 1250 len = sizeof(off_v1); 1251 to_copy = &off_v1; 1252 } 1253 1254 if (copy_to_user(optval, to_copy, len)) 1255 return -EFAULT; 1256 if (put_user(len, optlen)) 1257 return -EFAULT; 1258 1259 return 0; 1260 } 1261 case XDP_OPTIONS: 1262 { 1263 struct xdp_options opts = {}; 1264 1265 if (len < sizeof(opts)) 1266 return -EINVAL; 1267 1268 mutex_lock(&xs->mutex); 1269 if (xs->zc) 1270 opts.flags |= XDP_OPTIONS_ZEROCOPY; 1271 mutex_unlock(&xs->mutex); 1272 1273 len = sizeof(opts); 1274 if (copy_to_user(optval, &opts, len)) 1275 return -EFAULT; 1276 if (put_user(len, optlen)) 1277 return -EFAULT; 1278 1279 return 0; 1280 } 1281 default: 1282 break; 1283 } 1284 1285 return -EOPNOTSUPP; 1286 } 1287 1288 static int xsk_mmap(struct file *file, struct socket *sock, 1289 struct vm_area_struct *vma) 1290 { 1291 loff_t offset = (loff_t)vma->vm_pgoff << PAGE_SHIFT; 1292 unsigned long size = vma->vm_end - vma->vm_start; 1293 struct xdp_sock *xs = xdp_sk(sock->sk); 1294 struct xsk_queue *q = NULL; 1295 unsigned long pfn; 1296 struct page *qpg; 1297 1298 if (READ_ONCE(xs->state) != XSK_READY) 1299 return -EBUSY; 1300 1301 if (offset == XDP_PGOFF_RX_RING) { 1302 q = READ_ONCE(xs->rx); 1303 } else if (offset == XDP_PGOFF_TX_RING) { 1304 q = READ_ONCE(xs->tx); 1305 } else { 1306 /* Matches the smp_wmb() in XDP_UMEM_REG */ 1307 smp_rmb(); 1308 if (offset == XDP_UMEM_PGOFF_FILL_RING) 1309 q = READ_ONCE(xs->fq_tmp); 1310 else if (offset == XDP_UMEM_PGOFF_COMPLETION_RING) 1311 q = READ_ONCE(xs->cq_tmp); 1312 } 1313 1314 if (!q) 1315 return -EINVAL; 1316 1317 /* Matches the smp_wmb() in xsk_init_queue */ 1318 smp_rmb(); 1319 qpg = virt_to_head_page(q->ring); 1320 if (size > page_size(qpg)) 1321 return -EINVAL; 1322 1323 pfn = virt_to_phys(q->ring) >> PAGE_SHIFT; 1324 return remap_pfn_range(vma, vma->vm_start, pfn, 1325 size, vma->vm_page_prot); 1326 } 1327 1328 static int xsk_notifier(struct notifier_block *this, 1329 unsigned long msg, void *ptr) 1330 { 1331 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1332 struct net *net = dev_net(dev); 1333 struct sock *sk; 1334 1335 switch (msg) { 1336 case NETDEV_UNREGISTER: 1337 mutex_lock(&net->xdp.lock); 1338 sk_for_each(sk, &net->xdp.list) { 1339 struct xdp_sock *xs = xdp_sk(sk); 1340 1341 mutex_lock(&xs->mutex); 1342 if (xs->dev == dev) { 1343 sk->sk_err = ENETDOWN; 1344 if (!sock_flag(sk, SOCK_DEAD)) 1345 sk_error_report(sk); 1346 1347 xsk_unbind_dev(xs); 1348 1349 /* Clear device references. */ 1350 xp_clear_dev(xs->pool); 1351 } 1352 mutex_unlock(&xs->mutex); 1353 } 1354 mutex_unlock(&net->xdp.lock); 1355 break; 1356 } 1357 return NOTIFY_DONE; 1358 } 1359 1360 static struct proto xsk_proto = { 1361 .name = "XDP", 1362 .owner = THIS_MODULE, 1363 .obj_size = sizeof(struct xdp_sock), 1364 }; 1365 1366 static const struct proto_ops xsk_proto_ops = { 1367 .family = PF_XDP, 1368 .owner = THIS_MODULE, 1369 .release = xsk_release, 1370 .bind = xsk_bind, 1371 .connect = sock_no_connect, 1372 .socketpair = sock_no_socketpair, 1373 .accept = sock_no_accept, 1374 .getname = sock_no_getname, 1375 .poll = xsk_poll, 1376 .ioctl = sock_no_ioctl, 1377 .listen = sock_no_listen, 1378 .shutdown = sock_no_shutdown, 1379 .setsockopt = xsk_setsockopt, 1380 .getsockopt = xsk_getsockopt, 1381 .sendmsg = xsk_sendmsg, 1382 .recvmsg = xsk_recvmsg, 1383 .mmap = xsk_mmap, 1384 .sendpage = sock_no_sendpage, 1385 }; 1386 1387 static void xsk_destruct(struct sock *sk) 1388 { 1389 struct xdp_sock *xs = xdp_sk(sk); 1390 1391 if (!sock_flag(sk, SOCK_DEAD)) 1392 return; 1393 1394 if (!xp_put_pool(xs->pool)) 1395 xdp_put_umem(xs->umem, !xs->pool); 1396 1397 sk_refcnt_debug_dec(sk); 1398 } 1399 1400 static int xsk_create(struct net *net, struct socket *sock, int protocol, 1401 int kern) 1402 { 1403 struct xdp_sock *xs; 1404 struct sock *sk; 1405 1406 if (!ns_capable(net->user_ns, CAP_NET_RAW)) 1407 return -EPERM; 1408 if (sock->type != SOCK_RAW) 1409 return -ESOCKTNOSUPPORT; 1410 1411 if (protocol) 1412 return -EPROTONOSUPPORT; 1413 1414 sock->state = SS_UNCONNECTED; 1415 1416 sk = sk_alloc(net, PF_XDP, GFP_KERNEL, &xsk_proto, kern); 1417 if (!sk) 1418 return -ENOBUFS; 1419 1420 sock->ops = &xsk_proto_ops; 1421 1422 sock_init_data(sock, sk); 1423 1424 sk->sk_family = PF_XDP; 1425 1426 sk->sk_destruct = xsk_destruct; 1427 sk_refcnt_debug_inc(sk); 1428 1429 sock_set_flag(sk, SOCK_RCU_FREE); 1430 1431 xs = xdp_sk(sk); 1432 xs->state = XSK_READY; 1433 mutex_init(&xs->mutex); 1434 spin_lock_init(&xs->rx_lock); 1435 1436 INIT_LIST_HEAD(&xs->map_list); 1437 spin_lock_init(&xs->map_list_lock); 1438 1439 mutex_lock(&net->xdp.lock); 1440 sk_add_node_rcu(sk, &net->xdp.list); 1441 mutex_unlock(&net->xdp.lock); 1442 1443 sock_prot_inuse_add(net, &xsk_proto, 1); 1444 1445 return 0; 1446 } 1447 1448 static const struct net_proto_family xsk_family_ops = { 1449 .family = PF_XDP, 1450 .create = xsk_create, 1451 .owner = THIS_MODULE, 1452 }; 1453 1454 static struct notifier_block xsk_netdev_notifier = { 1455 .notifier_call = xsk_notifier, 1456 }; 1457 1458 static int __net_init xsk_net_init(struct net *net) 1459 { 1460 mutex_init(&net->xdp.lock); 1461 INIT_HLIST_HEAD(&net->xdp.list); 1462 return 0; 1463 } 1464 1465 static void __net_exit xsk_net_exit(struct net *net) 1466 { 1467 WARN_ON_ONCE(!hlist_empty(&net->xdp.list)); 1468 } 1469 1470 static struct pernet_operations xsk_net_ops = { 1471 .init = xsk_net_init, 1472 .exit = xsk_net_exit, 1473 }; 1474 1475 static int __init xsk_init(void) 1476 { 1477 int err, cpu; 1478 1479 err = proto_register(&xsk_proto, 0 /* no slab */); 1480 if (err) 1481 goto out; 1482 1483 err = sock_register(&xsk_family_ops); 1484 if (err) 1485 goto out_proto; 1486 1487 err = register_pernet_subsys(&xsk_net_ops); 1488 if (err) 1489 goto out_sk; 1490 1491 err = register_netdevice_notifier(&xsk_netdev_notifier); 1492 if (err) 1493 goto out_pernet; 1494 1495 for_each_possible_cpu(cpu) 1496 INIT_LIST_HEAD(&per_cpu(xskmap_flush_list, cpu)); 1497 return 0; 1498 1499 out_pernet: 1500 unregister_pernet_subsys(&xsk_net_ops); 1501 out_sk: 1502 sock_unregister(PF_XDP); 1503 out_proto: 1504 proto_unregister(&xsk_proto); 1505 out: 1506 return err; 1507 } 1508 1509 fs_initcall(xsk_init); 1510