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