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 <linux/vmalloc.h> 26 #include <net/xdp_sock_drv.h> 27 #include <net/busy_poll.h> 28 #include <net/xdp.h> 29 30 #include "xsk_queue.h" 31 #include "xdp_umem.h" 32 #include "xsk.h" 33 34 #define TX_BATCH_SIZE 32 35 36 static DEFINE_PER_CPU(struct list_head, xskmap_flush_list); 37 38 void xsk_set_rx_need_wakeup(struct xsk_buff_pool *pool) 39 { 40 if (pool->cached_need_wakeup & XDP_WAKEUP_RX) 41 return; 42 43 pool->fq->ring->flags |= XDP_RING_NEED_WAKEUP; 44 pool->cached_need_wakeup |= XDP_WAKEUP_RX; 45 } 46 EXPORT_SYMBOL(xsk_set_rx_need_wakeup); 47 48 void xsk_set_tx_need_wakeup(struct xsk_buff_pool *pool) 49 { 50 struct xdp_sock *xs; 51 52 if (pool->cached_need_wakeup & XDP_WAKEUP_TX) 53 return; 54 55 rcu_read_lock(); 56 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) { 57 xs->tx->ring->flags |= XDP_RING_NEED_WAKEUP; 58 } 59 rcu_read_unlock(); 60 61 pool->cached_need_wakeup |= XDP_WAKEUP_TX; 62 } 63 EXPORT_SYMBOL(xsk_set_tx_need_wakeup); 64 65 void xsk_clear_rx_need_wakeup(struct xsk_buff_pool *pool) 66 { 67 if (!(pool->cached_need_wakeup & XDP_WAKEUP_RX)) 68 return; 69 70 pool->fq->ring->flags &= ~XDP_RING_NEED_WAKEUP; 71 pool->cached_need_wakeup &= ~XDP_WAKEUP_RX; 72 } 73 EXPORT_SYMBOL(xsk_clear_rx_need_wakeup); 74 75 void xsk_clear_tx_need_wakeup(struct xsk_buff_pool *pool) 76 { 77 struct xdp_sock *xs; 78 79 if (!(pool->cached_need_wakeup & XDP_WAKEUP_TX)) 80 return; 81 82 rcu_read_lock(); 83 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) { 84 xs->tx->ring->flags &= ~XDP_RING_NEED_WAKEUP; 85 } 86 rcu_read_unlock(); 87 88 pool->cached_need_wakeup &= ~XDP_WAKEUP_TX; 89 } 90 EXPORT_SYMBOL(xsk_clear_tx_need_wakeup); 91 92 bool xsk_uses_need_wakeup(struct xsk_buff_pool *pool) 93 { 94 return pool->uses_need_wakeup; 95 } 96 EXPORT_SYMBOL(xsk_uses_need_wakeup); 97 98 struct xsk_buff_pool *xsk_get_pool_from_qid(struct net_device *dev, 99 u16 queue_id) 100 { 101 if (queue_id < dev->real_num_rx_queues) 102 return dev->_rx[queue_id].pool; 103 if (queue_id < dev->real_num_tx_queues) 104 return dev->_tx[queue_id].pool; 105 106 return NULL; 107 } 108 EXPORT_SYMBOL(xsk_get_pool_from_qid); 109 110 void xsk_clear_pool_at_qid(struct net_device *dev, u16 queue_id) 111 { 112 if (queue_id < dev->num_rx_queues) 113 dev->_rx[queue_id].pool = NULL; 114 if (queue_id < dev->num_tx_queues) 115 dev->_tx[queue_id].pool = NULL; 116 } 117 118 /* The buffer pool is stored both in the _rx struct and the _tx struct as we do 119 * not know if the device has more tx queues than rx, or the opposite. 120 * This might also change during run time. 121 */ 122 int xsk_reg_pool_at_qid(struct net_device *dev, struct xsk_buff_pool *pool, 123 u16 queue_id) 124 { 125 if (queue_id >= max_t(unsigned int, 126 dev->real_num_rx_queues, 127 dev->real_num_tx_queues)) 128 return -EINVAL; 129 130 if (queue_id < dev->real_num_rx_queues) 131 dev->_rx[queue_id].pool = pool; 132 if (queue_id < dev->real_num_tx_queues) 133 dev->_tx[queue_id].pool = pool; 134 135 return 0; 136 } 137 138 static int __xsk_rcv_zc(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len) 139 { 140 struct xdp_buff_xsk *xskb = container_of(xdp, struct xdp_buff_xsk, xdp); 141 u64 addr; 142 int err; 143 144 addr = xp_get_handle(xskb); 145 err = xskq_prod_reserve_desc(xs->rx, addr, len); 146 if (err) { 147 xs->rx_queue_full++; 148 return err; 149 } 150 151 xp_release(xskb); 152 return 0; 153 } 154 155 static void xsk_copy_xdp(struct xdp_buff *to, struct xdp_buff *from, u32 len) 156 { 157 void *from_buf, *to_buf; 158 u32 metalen; 159 160 if (unlikely(xdp_data_meta_unsupported(from))) { 161 from_buf = from->data; 162 to_buf = to->data; 163 metalen = 0; 164 } else { 165 from_buf = from->data_meta; 166 metalen = from->data - from->data_meta; 167 to_buf = to->data - metalen; 168 } 169 170 memcpy(to_buf, from_buf, len + metalen); 171 } 172 173 static int __xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp) 174 { 175 struct xdp_buff *xsk_xdp; 176 int err; 177 u32 len; 178 179 len = xdp->data_end - xdp->data; 180 if (len > xsk_pool_get_rx_frame_size(xs->pool)) { 181 xs->rx_dropped++; 182 return -ENOSPC; 183 } 184 185 xsk_xdp = xsk_buff_alloc(xs->pool); 186 if (!xsk_xdp) { 187 xs->rx_dropped++; 188 return -ENOMEM; 189 } 190 191 xsk_copy_xdp(xsk_xdp, xdp, len); 192 err = __xsk_rcv_zc(xs, xsk_xdp, len); 193 if (err) { 194 xsk_buff_free(xsk_xdp); 195 return err; 196 } 197 return 0; 198 } 199 200 static bool xsk_tx_writeable(struct xdp_sock *xs) 201 { 202 if (xskq_cons_present_entries(xs->tx) > xs->tx->nentries / 2) 203 return false; 204 205 return true; 206 } 207 208 static bool xsk_is_bound(struct xdp_sock *xs) 209 { 210 if (READ_ONCE(xs->state) == XSK_BOUND) { 211 /* Matches smp_wmb() in bind(). */ 212 smp_rmb(); 213 return true; 214 } 215 return false; 216 } 217 218 static int xsk_rcv_check(struct xdp_sock *xs, struct xdp_buff *xdp) 219 { 220 if (!xsk_is_bound(xs)) 221 return -ENXIO; 222 223 if (xs->dev != xdp->rxq->dev || xs->queue_id != xdp->rxq->queue_index) 224 return -EINVAL; 225 226 sk_mark_napi_id_once_xdp(&xs->sk, xdp); 227 return 0; 228 } 229 230 static void xsk_flush(struct xdp_sock *xs) 231 { 232 xskq_prod_submit(xs->rx); 233 __xskq_cons_release(xs->pool->fq); 234 sock_def_readable(&xs->sk); 235 } 236 237 int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp) 238 { 239 int err; 240 241 spin_lock_bh(&xs->rx_lock); 242 err = xsk_rcv_check(xs, xdp); 243 if (!err) { 244 err = __xsk_rcv(xs, xdp); 245 xsk_flush(xs); 246 } 247 spin_unlock_bh(&xs->rx_lock); 248 return err; 249 } 250 251 static int xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp) 252 { 253 int err; 254 u32 len; 255 256 err = xsk_rcv_check(xs, xdp); 257 if (err) 258 return err; 259 260 if (xdp->rxq->mem.type == MEM_TYPE_XSK_BUFF_POOL) { 261 len = xdp->data_end - xdp->data; 262 return __xsk_rcv_zc(xs, xdp, len); 263 } 264 265 err = __xsk_rcv(xs, xdp); 266 if (!err) 267 xdp_return_buff(xdp); 268 return err; 269 } 270 271 int __xsk_map_redirect(struct xdp_sock *xs, struct xdp_buff *xdp) 272 { 273 struct list_head *flush_list = this_cpu_ptr(&xskmap_flush_list); 274 int err; 275 276 err = xsk_rcv(xs, xdp); 277 if (err) 278 return err; 279 280 if (!xs->flush_node.prev) 281 list_add(&xs->flush_node, flush_list); 282 283 return 0; 284 } 285 286 void __xsk_map_flush(void) 287 { 288 struct list_head *flush_list = this_cpu_ptr(&xskmap_flush_list); 289 struct xdp_sock *xs, *tmp; 290 291 list_for_each_entry_safe(xs, tmp, flush_list, flush_node) { 292 xsk_flush(xs); 293 __list_del_clearprev(&xs->flush_node); 294 } 295 } 296 297 void xsk_tx_completed(struct xsk_buff_pool *pool, u32 nb_entries) 298 { 299 xskq_prod_submit_n(pool->cq, nb_entries); 300 } 301 EXPORT_SYMBOL(xsk_tx_completed); 302 303 void xsk_tx_release(struct xsk_buff_pool *pool) 304 { 305 struct xdp_sock *xs; 306 307 rcu_read_lock(); 308 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) { 309 __xskq_cons_release(xs->tx); 310 if (xsk_tx_writeable(xs)) 311 xs->sk.sk_write_space(&xs->sk); 312 } 313 rcu_read_unlock(); 314 } 315 EXPORT_SYMBOL(xsk_tx_release); 316 317 bool xsk_tx_peek_desc(struct xsk_buff_pool *pool, struct xdp_desc *desc) 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 if (!xskq_cons_peek_desc(xs->tx, desc, pool)) { 324 xs->tx->queue_empty_descs++; 325 continue; 326 } 327 328 /* This is the backpressure mechanism for the Tx path. 329 * Reserve space in the completion queue and only proceed 330 * if there is space in it. This avoids having to implement 331 * any buffering in the Tx path. 332 */ 333 if (xskq_prod_reserve_addr(pool->cq, desc->addr)) 334 goto out; 335 336 xskq_cons_release(xs->tx); 337 rcu_read_unlock(); 338 return true; 339 } 340 341 out: 342 rcu_read_unlock(); 343 return false; 344 } 345 EXPORT_SYMBOL(xsk_tx_peek_desc); 346 347 static u32 xsk_tx_peek_release_fallback(struct xsk_buff_pool *pool, u32 max_entries) 348 { 349 struct xdp_desc *descs = pool->tx_descs; 350 u32 nb_pkts = 0; 351 352 while (nb_pkts < max_entries && xsk_tx_peek_desc(pool, &descs[nb_pkts])) 353 nb_pkts++; 354 355 xsk_tx_release(pool); 356 return nb_pkts; 357 } 358 359 u32 xsk_tx_peek_release_desc_batch(struct xsk_buff_pool *pool, u32 nb_pkts) 360 { 361 struct xdp_sock *xs; 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, nb_pkts); 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 nb_pkts = xskq_cons_nb_entries(xs->tx, nb_pkts); 377 378 /* This is the backpressure mechanism for the Tx path. Try to 379 * reserve space in the completion queue for all packets, but 380 * if there are fewer slots available, just process that many 381 * packets. This avoids having to implement any buffering in 382 * the Tx path. 383 */ 384 nb_pkts = xskq_prod_nb_free(pool->cq, nb_pkts); 385 if (!nb_pkts) 386 goto out; 387 388 nb_pkts = xskq_cons_read_desc_batch(xs->tx, pool, nb_pkts); 389 if (!nb_pkts) { 390 xs->tx->queue_empty_descs++; 391 goto out; 392 } 393 394 __xskq_cons_release(xs->tx); 395 xskq_prod_write_addr_batch(pool->cq, pool->tx_descs, nb_pkts); 396 xs->sk.sk_write_space(&xs->sk); 397 398 out: 399 rcu_read_unlock(); 400 return nb_pkts; 401 } 402 EXPORT_SYMBOL(xsk_tx_peek_release_desc_batch); 403 404 static int xsk_wakeup(struct xdp_sock *xs, u8 flags) 405 { 406 struct net_device *dev = xs->dev; 407 408 return dev->netdev_ops->ndo_xsk_wakeup(dev, xs->queue_id, flags); 409 } 410 411 static void xsk_destruct_skb(struct sk_buff *skb) 412 { 413 u64 addr = (u64)(long)skb_shinfo(skb)->destructor_arg; 414 struct xdp_sock *xs = xdp_sk(skb->sk); 415 unsigned long flags; 416 417 spin_lock_irqsave(&xs->pool->cq_lock, flags); 418 xskq_prod_submit_addr(xs->pool->cq, addr); 419 spin_unlock_irqrestore(&xs->pool->cq_lock, flags); 420 421 sock_wfree(skb); 422 } 423 424 static struct sk_buff *xsk_build_skb_zerocopy(struct xdp_sock *xs, 425 struct xdp_desc *desc) 426 { 427 struct xsk_buff_pool *pool = xs->pool; 428 u32 hr, len, ts, offset, copy, copied; 429 struct sk_buff *skb; 430 struct page *page; 431 void *buffer; 432 int err, i; 433 u64 addr; 434 435 hr = max(NET_SKB_PAD, L1_CACHE_ALIGN(xs->dev->needed_headroom)); 436 437 skb = sock_alloc_send_skb(&xs->sk, hr, 1, &err); 438 if (unlikely(!skb)) 439 return ERR_PTR(err); 440 441 skb_reserve(skb, hr); 442 443 addr = desc->addr; 444 len = desc->len; 445 ts = pool->unaligned ? len : pool->chunk_size; 446 447 buffer = xsk_buff_raw_get_data(pool, addr); 448 offset = offset_in_page(buffer); 449 addr = buffer - pool->addrs; 450 451 for (copied = 0, i = 0; copied < len; i++) { 452 page = pool->umem->pgs[addr >> PAGE_SHIFT]; 453 get_page(page); 454 455 copy = min_t(u32, PAGE_SIZE - offset, len - copied); 456 skb_fill_page_desc(skb, i, page, offset, copy); 457 458 copied += copy; 459 addr += copy; 460 offset = 0; 461 } 462 463 skb->len += len; 464 skb->data_len += len; 465 skb->truesize += ts; 466 467 refcount_add(ts, &xs->sk.sk_wmem_alloc); 468 469 return skb; 470 } 471 472 static struct sk_buff *xsk_build_skb(struct xdp_sock *xs, 473 struct xdp_desc *desc) 474 { 475 struct net_device *dev = xs->dev; 476 struct sk_buff *skb; 477 478 if (dev->priv_flags & IFF_TX_SKB_NO_LINEAR) { 479 skb = xsk_build_skb_zerocopy(xs, desc); 480 if (IS_ERR(skb)) 481 return skb; 482 } else { 483 u32 hr, tr, len; 484 void *buffer; 485 int err; 486 487 hr = max(NET_SKB_PAD, L1_CACHE_ALIGN(dev->needed_headroom)); 488 tr = dev->needed_tailroom; 489 len = desc->len; 490 491 skb = sock_alloc_send_skb(&xs->sk, hr + len + tr, 1, &err); 492 if (unlikely(!skb)) 493 return ERR_PTR(err); 494 495 skb_reserve(skb, hr); 496 skb_put(skb, len); 497 498 buffer = xsk_buff_raw_get_data(xs->pool, desc->addr); 499 err = skb_store_bits(skb, 0, buffer, len); 500 if (unlikely(err)) { 501 kfree_skb(skb); 502 return ERR_PTR(err); 503 } 504 } 505 506 skb->dev = dev; 507 skb->priority = xs->sk.sk_priority; 508 skb->mark = xs->sk.sk_mark; 509 skb_shinfo(skb)->destructor_arg = (void *)(long)desc->addr; 510 skb->destructor = xsk_destruct_skb; 511 512 return skb; 513 } 514 515 static int __xsk_generic_xmit(struct sock *sk) 516 { 517 struct xdp_sock *xs = xdp_sk(sk); 518 u32 max_batch = TX_BATCH_SIZE; 519 bool sent_frame = false; 520 struct xdp_desc desc; 521 struct sk_buff *skb; 522 unsigned long flags; 523 int err = 0; 524 525 mutex_lock(&xs->mutex); 526 527 /* Since we dropped the RCU read lock, the socket state might have changed. */ 528 if (unlikely(!xsk_is_bound(xs))) { 529 err = -ENXIO; 530 goto out; 531 } 532 533 if (xs->queue_id >= xs->dev->real_num_tx_queues) 534 goto out; 535 536 while (xskq_cons_peek_desc(xs->tx, &desc, xs->pool)) { 537 if (max_batch-- == 0) { 538 err = -EAGAIN; 539 goto out; 540 } 541 542 /* This is the backpressure mechanism for the Tx path. 543 * Reserve space in the completion queue and only proceed 544 * if there is space in it. This avoids having to implement 545 * any buffering in the Tx path. 546 */ 547 spin_lock_irqsave(&xs->pool->cq_lock, flags); 548 if (xskq_prod_reserve(xs->pool->cq)) { 549 spin_unlock_irqrestore(&xs->pool->cq_lock, flags); 550 goto out; 551 } 552 spin_unlock_irqrestore(&xs->pool->cq_lock, flags); 553 554 skb = xsk_build_skb(xs, &desc); 555 if (IS_ERR(skb)) { 556 err = PTR_ERR(skb); 557 spin_lock_irqsave(&xs->pool->cq_lock, flags); 558 xskq_prod_cancel(xs->pool->cq); 559 spin_unlock_irqrestore(&xs->pool->cq_lock, flags); 560 goto out; 561 } 562 563 err = __dev_direct_xmit(skb, xs->queue_id); 564 if (err == NETDEV_TX_BUSY) { 565 /* Tell user-space to retry the send */ 566 skb->destructor = sock_wfree; 567 spin_lock_irqsave(&xs->pool->cq_lock, flags); 568 xskq_prod_cancel(xs->pool->cq); 569 spin_unlock_irqrestore(&xs->pool->cq_lock, flags); 570 /* Free skb without triggering the perf drop trace */ 571 consume_skb(skb); 572 err = -EAGAIN; 573 goto out; 574 } 575 576 xskq_cons_release(xs->tx); 577 /* Ignore NET_XMIT_CN as packet might have been sent */ 578 if (err == NET_XMIT_DROP) { 579 /* SKB completed but not sent */ 580 err = -EBUSY; 581 goto out; 582 } 583 584 sent_frame = true; 585 } 586 587 xs->tx->queue_empty_descs++; 588 589 out: 590 if (sent_frame) 591 if (xsk_tx_writeable(xs)) 592 sk->sk_write_space(sk); 593 594 mutex_unlock(&xs->mutex); 595 return err; 596 } 597 598 static int xsk_generic_xmit(struct sock *sk) 599 { 600 int ret; 601 602 /* Drop the RCU lock since the SKB path might sleep. */ 603 rcu_read_unlock(); 604 ret = __xsk_generic_xmit(sk); 605 /* Reaquire RCU lock before going into common code. */ 606 rcu_read_lock(); 607 608 return ret; 609 } 610 611 static bool xsk_no_wakeup(struct sock *sk) 612 { 613 #ifdef CONFIG_NET_RX_BUSY_POLL 614 /* Prefer busy-polling, skip the wakeup. */ 615 return READ_ONCE(sk->sk_prefer_busy_poll) && READ_ONCE(sk->sk_ll_usec) && 616 READ_ONCE(sk->sk_napi_id) >= MIN_NAPI_ID; 617 #else 618 return false; 619 #endif 620 } 621 622 static int xsk_check_common(struct xdp_sock *xs) 623 { 624 if (unlikely(!xsk_is_bound(xs))) 625 return -ENXIO; 626 if (unlikely(!(xs->dev->flags & IFF_UP))) 627 return -ENETDOWN; 628 629 return 0; 630 } 631 632 static int __xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len) 633 { 634 bool need_wait = !(m->msg_flags & MSG_DONTWAIT); 635 struct sock *sk = sock->sk; 636 struct xdp_sock *xs = xdp_sk(sk); 637 struct xsk_buff_pool *pool; 638 int err; 639 640 err = xsk_check_common(xs); 641 if (err) 642 return err; 643 if (unlikely(need_wait)) 644 return -EOPNOTSUPP; 645 if (unlikely(!xs->tx)) 646 return -ENOBUFS; 647 648 if (sk_can_busy_loop(sk)) { 649 if (xs->zc) 650 __sk_mark_napi_id_once(sk, xsk_pool_get_napi_id(xs->pool)); 651 sk_busy_loop(sk, 1); /* only support non-blocking sockets */ 652 } 653 654 if (xs->zc && xsk_no_wakeup(sk)) 655 return 0; 656 657 pool = xs->pool; 658 if (pool->cached_need_wakeup & XDP_WAKEUP_TX) { 659 if (xs->zc) 660 return xsk_wakeup(xs, XDP_WAKEUP_TX); 661 return xsk_generic_xmit(sk); 662 } 663 return 0; 664 } 665 666 static int xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len) 667 { 668 int ret; 669 670 rcu_read_lock(); 671 ret = __xsk_sendmsg(sock, m, total_len); 672 rcu_read_unlock(); 673 674 return ret; 675 } 676 677 static int __xsk_recvmsg(struct socket *sock, struct msghdr *m, size_t len, int flags) 678 { 679 bool need_wait = !(flags & MSG_DONTWAIT); 680 struct sock *sk = sock->sk; 681 struct xdp_sock *xs = xdp_sk(sk); 682 int err; 683 684 err = xsk_check_common(xs); 685 if (err) 686 return err; 687 if (unlikely(!xs->rx)) 688 return -ENOBUFS; 689 if (unlikely(need_wait)) 690 return -EOPNOTSUPP; 691 692 if (sk_can_busy_loop(sk)) 693 sk_busy_loop(sk, 1); /* only support non-blocking sockets */ 694 695 if (xsk_no_wakeup(sk)) 696 return 0; 697 698 if (xs->pool->cached_need_wakeup & XDP_WAKEUP_RX && xs->zc) 699 return xsk_wakeup(xs, XDP_WAKEUP_RX); 700 return 0; 701 } 702 703 static int xsk_recvmsg(struct socket *sock, struct msghdr *m, size_t len, int flags) 704 { 705 int ret; 706 707 rcu_read_lock(); 708 ret = __xsk_recvmsg(sock, m, len, flags); 709 rcu_read_unlock(); 710 711 return ret; 712 } 713 714 static __poll_t xsk_poll(struct file *file, struct socket *sock, 715 struct poll_table_struct *wait) 716 { 717 __poll_t mask = 0; 718 struct sock *sk = sock->sk; 719 struct xdp_sock *xs = xdp_sk(sk); 720 struct xsk_buff_pool *pool; 721 722 sock_poll_wait(file, sock, wait); 723 724 rcu_read_lock(); 725 if (xsk_check_common(xs)) 726 goto skip_tx; 727 728 pool = xs->pool; 729 730 if (pool->cached_need_wakeup) { 731 if (xs->zc) 732 xsk_wakeup(xs, pool->cached_need_wakeup); 733 else if (xs->tx) 734 /* Poll needs to drive Tx also in copy mode */ 735 xsk_generic_xmit(sk); 736 } 737 738 skip_tx: 739 if (xs->rx && !xskq_prod_is_empty(xs->rx)) 740 mask |= EPOLLIN | EPOLLRDNORM; 741 if (xs->tx && xsk_tx_writeable(xs)) 742 mask |= EPOLLOUT | EPOLLWRNORM; 743 744 rcu_read_unlock(); 745 return mask; 746 } 747 748 static int xsk_init_queue(u32 entries, struct xsk_queue **queue, 749 bool umem_queue) 750 { 751 struct xsk_queue *q; 752 753 if (entries == 0 || *queue || !is_power_of_2(entries)) 754 return -EINVAL; 755 756 q = xskq_create(entries, umem_queue); 757 if (!q) 758 return -ENOMEM; 759 760 /* Make sure queue is ready before it can be seen by others */ 761 smp_wmb(); 762 WRITE_ONCE(*queue, q); 763 return 0; 764 } 765 766 static void xsk_unbind_dev(struct xdp_sock *xs) 767 { 768 struct net_device *dev = xs->dev; 769 770 if (xs->state != XSK_BOUND) 771 return; 772 WRITE_ONCE(xs->state, XSK_UNBOUND); 773 774 /* Wait for driver to stop using the xdp socket. */ 775 xp_del_xsk(xs->pool, xs); 776 synchronize_net(); 777 dev_put(dev); 778 } 779 780 static struct xsk_map *xsk_get_map_list_entry(struct xdp_sock *xs, 781 struct xdp_sock __rcu ***map_entry) 782 { 783 struct xsk_map *map = NULL; 784 struct xsk_map_node *node; 785 786 *map_entry = NULL; 787 788 spin_lock_bh(&xs->map_list_lock); 789 node = list_first_entry_or_null(&xs->map_list, struct xsk_map_node, 790 node); 791 if (node) { 792 bpf_map_inc(&node->map->map); 793 map = node->map; 794 *map_entry = node->map_entry; 795 } 796 spin_unlock_bh(&xs->map_list_lock); 797 return map; 798 } 799 800 static void xsk_delete_from_maps(struct xdp_sock *xs) 801 { 802 /* This function removes the current XDP socket from all the 803 * maps it resides in. We need to take extra care here, due to 804 * the two locks involved. Each map has a lock synchronizing 805 * updates to the entries, and each socket has a lock that 806 * synchronizes access to the list of maps (map_list). For 807 * deadlock avoidance the locks need to be taken in the order 808 * "map lock"->"socket map list lock". We start off by 809 * accessing the socket map list, and take a reference to the 810 * map to guarantee existence between the 811 * xsk_get_map_list_entry() and xsk_map_try_sock_delete() 812 * calls. Then we ask the map to remove the socket, which 813 * tries to remove the socket from the map. Note that there 814 * might be updates to the map between 815 * xsk_get_map_list_entry() and xsk_map_try_sock_delete(). 816 */ 817 struct xdp_sock __rcu **map_entry = NULL; 818 struct xsk_map *map; 819 820 while ((map = xsk_get_map_list_entry(xs, &map_entry))) { 821 xsk_map_try_sock_delete(map, xs, map_entry); 822 bpf_map_put(&map->map); 823 } 824 } 825 826 static int xsk_release(struct socket *sock) 827 { 828 struct sock *sk = sock->sk; 829 struct xdp_sock *xs = xdp_sk(sk); 830 struct net *net; 831 832 if (!sk) 833 return 0; 834 835 net = sock_net(sk); 836 837 mutex_lock(&net->xdp.lock); 838 sk_del_node_init_rcu(sk); 839 mutex_unlock(&net->xdp.lock); 840 841 sock_prot_inuse_add(net, sk->sk_prot, -1); 842 843 xsk_delete_from_maps(xs); 844 mutex_lock(&xs->mutex); 845 xsk_unbind_dev(xs); 846 mutex_unlock(&xs->mutex); 847 848 xskq_destroy(xs->rx); 849 xskq_destroy(xs->tx); 850 xskq_destroy(xs->fq_tmp); 851 xskq_destroy(xs->cq_tmp); 852 853 sock_orphan(sk); 854 sock->sk = NULL; 855 856 sock_put(sk); 857 858 return 0; 859 } 860 861 static struct socket *xsk_lookup_xsk_from_fd(int fd) 862 { 863 struct socket *sock; 864 int err; 865 866 sock = sockfd_lookup(fd, &err); 867 if (!sock) 868 return ERR_PTR(-ENOTSOCK); 869 870 if (sock->sk->sk_family != PF_XDP) { 871 sockfd_put(sock); 872 return ERR_PTR(-ENOPROTOOPT); 873 } 874 875 return sock; 876 } 877 878 static bool xsk_validate_queues(struct xdp_sock *xs) 879 { 880 return xs->fq_tmp && xs->cq_tmp; 881 } 882 883 static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len) 884 { 885 struct sockaddr_xdp *sxdp = (struct sockaddr_xdp *)addr; 886 struct sock *sk = sock->sk; 887 struct xdp_sock *xs = xdp_sk(sk); 888 struct net_device *dev; 889 u32 flags, qid; 890 int err = 0; 891 892 if (addr_len < sizeof(struct sockaddr_xdp)) 893 return -EINVAL; 894 if (sxdp->sxdp_family != AF_XDP) 895 return -EINVAL; 896 897 flags = sxdp->sxdp_flags; 898 if (flags & ~(XDP_SHARED_UMEM | XDP_COPY | XDP_ZEROCOPY | 899 XDP_USE_NEED_WAKEUP)) 900 return -EINVAL; 901 902 rtnl_lock(); 903 mutex_lock(&xs->mutex); 904 if (xs->state != XSK_READY) { 905 err = -EBUSY; 906 goto out_release; 907 } 908 909 dev = dev_get_by_index(sock_net(sk), sxdp->sxdp_ifindex); 910 if (!dev) { 911 err = -ENODEV; 912 goto out_release; 913 } 914 915 if (!xs->rx && !xs->tx) { 916 err = -EINVAL; 917 goto out_unlock; 918 } 919 920 qid = sxdp->sxdp_queue_id; 921 922 if (flags & XDP_SHARED_UMEM) { 923 struct xdp_sock *umem_xs; 924 struct socket *sock; 925 926 if ((flags & XDP_COPY) || (flags & XDP_ZEROCOPY) || 927 (flags & XDP_USE_NEED_WAKEUP)) { 928 /* Cannot specify flags for shared sockets. */ 929 err = -EINVAL; 930 goto out_unlock; 931 } 932 933 if (xs->umem) { 934 /* We have already our own. */ 935 err = -EINVAL; 936 goto out_unlock; 937 } 938 939 sock = xsk_lookup_xsk_from_fd(sxdp->sxdp_shared_umem_fd); 940 if (IS_ERR(sock)) { 941 err = PTR_ERR(sock); 942 goto out_unlock; 943 } 944 945 umem_xs = xdp_sk(sock->sk); 946 if (!xsk_is_bound(umem_xs)) { 947 err = -EBADF; 948 sockfd_put(sock); 949 goto out_unlock; 950 } 951 952 if (umem_xs->queue_id != qid || umem_xs->dev != dev) { 953 /* Share the umem with another socket on another qid 954 * and/or device. 955 */ 956 xs->pool = xp_create_and_assign_umem(xs, 957 umem_xs->umem); 958 if (!xs->pool) { 959 err = -ENOMEM; 960 sockfd_put(sock); 961 goto out_unlock; 962 } 963 964 err = xp_assign_dev_shared(xs->pool, umem_xs, dev, 965 qid); 966 if (err) { 967 xp_destroy(xs->pool); 968 xs->pool = NULL; 969 sockfd_put(sock); 970 goto out_unlock; 971 } 972 } else { 973 /* Share the buffer pool with the other socket. */ 974 if (xs->fq_tmp || xs->cq_tmp) { 975 /* Do not allow setting your own fq or cq. */ 976 err = -EINVAL; 977 sockfd_put(sock); 978 goto out_unlock; 979 } 980 981 xp_get_pool(umem_xs->pool); 982 xs->pool = umem_xs->pool; 983 984 /* If underlying shared umem was created without Tx 985 * ring, allocate Tx descs array that Tx batching API 986 * utilizes 987 */ 988 if (xs->tx && !xs->pool->tx_descs) { 989 err = xp_alloc_tx_descs(xs->pool, xs); 990 if (err) { 991 xp_put_pool(xs->pool); 992 sockfd_put(sock); 993 goto out_unlock; 994 } 995 } 996 } 997 998 xdp_get_umem(umem_xs->umem); 999 WRITE_ONCE(xs->umem, umem_xs->umem); 1000 sockfd_put(sock); 1001 } else if (!xs->umem || !xsk_validate_queues(xs)) { 1002 err = -EINVAL; 1003 goto out_unlock; 1004 } else { 1005 /* This xsk has its own umem. */ 1006 xs->pool = xp_create_and_assign_umem(xs, xs->umem); 1007 if (!xs->pool) { 1008 err = -ENOMEM; 1009 goto out_unlock; 1010 } 1011 1012 err = xp_assign_dev(xs->pool, dev, qid, flags); 1013 if (err) { 1014 xp_destroy(xs->pool); 1015 xs->pool = NULL; 1016 goto out_unlock; 1017 } 1018 } 1019 1020 /* FQ and CQ are now owned by the buffer pool and cleaned up with it. */ 1021 xs->fq_tmp = NULL; 1022 xs->cq_tmp = NULL; 1023 1024 xs->dev = dev; 1025 xs->zc = xs->umem->zc; 1026 xs->queue_id = qid; 1027 xp_add_xsk(xs->pool, xs); 1028 1029 out_unlock: 1030 if (err) { 1031 dev_put(dev); 1032 } else { 1033 /* Matches smp_rmb() in bind() for shared umem 1034 * sockets, and xsk_is_bound(). 1035 */ 1036 smp_wmb(); 1037 WRITE_ONCE(xs->state, XSK_BOUND); 1038 } 1039 out_release: 1040 mutex_unlock(&xs->mutex); 1041 rtnl_unlock(); 1042 return err; 1043 } 1044 1045 struct xdp_umem_reg_v1 { 1046 __u64 addr; /* Start of packet data area */ 1047 __u64 len; /* Length of packet data area */ 1048 __u32 chunk_size; 1049 __u32 headroom; 1050 }; 1051 1052 static int xsk_setsockopt(struct socket *sock, int level, int optname, 1053 sockptr_t optval, unsigned int optlen) 1054 { 1055 struct sock *sk = sock->sk; 1056 struct xdp_sock *xs = xdp_sk(sk); 1057 int err; 1058 1059 if (level != SOL_XDP) 1060 return -ENOPROTOOPT; 1061 1062 switch (optname) { 1063 case XDP_RX_RING: 1064 case XDP_TX_RING: 1065 { 1066 struct xsk_queue **q; 1067 int entries; 1068 1069 if (optlen < sizeof(entries)) 1070 return -EINVAL; 1071 if (copy_from_sockptr(&entries, optval, sizeof(entries))) 1072 return -EFAULT; 1073 1074 mutex_lock(&xs->mutex); 1075 if (xs->state != XSK_READY) { 1076 mutex_unlock(&xs->mutex); 1077 return -EBUSY; 1078 } 1079 q = (optname == XDP_TX_RING) ? &xs->tx : &xs->rx; 1080 err = xsk_init_queue(entries, q, false); 1081 if (!err && optname == XDP_TX_RING) 1082 /* Tx needs to be explicitly woken up the first time */ 1083 xs->tx->ring->flags |= XDP_RING_NEED_WAKEUP; 1084 mutex_unlock(&xs->mutex); 1085 return err; 1086 } 1087 case XDP_UMEM_REG: 1088 { 1089 size_t mr_size = sizeof(struct xdp_umem_reg); 1090 struct xdp_umem_reg mr = {}; 1091 struct xdp_umem *umem; 1092 1093 if (optlen < sizeof(struct xdp_umem_reg_v1)) 1094 return -EINVAL; 1095 else if (optlen < sizeof(mr)) 1096 mr_size = sizeof(struct xdp_umem_reg_v1); 1097 1098 if (copy_from_sockptr(&mr, optval, mr_size)) 1099 return -EFAULT; 1100 1101 mutex_lock(&xs->mutex); 1102 if (xs->state != XSK_READY || xs->umem) { 1103 mutex_unlock(&xs->mutex); 1104 return -EBUSY; 1105 } 1106 1107 umem = xdp_umem_create(&mr); 1108 if (IS_ERR(umem)) { 1109 mutex_unlock(&xs->mutex); 1110 return PTR_ERR(umem); 1111 } 1112 1113 /* Make sure umem is ready before it can be seen by others */ 1114 smp_wmb(); 1115 WRITE_ONCE(xs->umem, umem); 1116 mutex_unlock(&xs->mutex); 1117 return 0; 1118 } 1119 case XDP_UMEM_FILL_RING: 1120 case XDP_UMEM_COMPLETION_RING: 1121 { 1122 struct xsk_queue **q; 1123 int entries; 1124 1125 if (copy_from_sockptr(&entries, optval, sizeof(entries))) 1126 return -EFAULT; 1127 1128 mutex_lock(&xs->mutex); 1129 if (xs->state != XSK_READY) { 1130 mutex_unlock(&xs->mutex); 1131 return -EBUSY; 1132 } 1133 1134 q = (optname == XDP_UMEM_FILL_RING) ? &xs->fq_tmp : 1135 &xs->cq_tmp; 1136 err = xsk_init_queue(entries, q, true); 1137 mutex_unlock(&xs->mutex); 1138 return err; 1139 } 1140 default: 1141 break; 1142 } 1143 1144 return -ENOPROTOOPT; 1145 } 1146 1147 static void xsk_enter_rxtx_offsets(struct xdp_ring_offset_v1 *ring) 1148 { 1149 ring->producer = offsetof(struct xdp_rxtx_ring, ptrs.producer); 1150 ring->consumer = offsetof(struct xdp_rxtx_ring, ptrs.consumer); 1151 ring->desc = offsetof(struct xdp_rxtx_ring, desc); 1152 } 1153 1154 static void xsk_enter_umem_offsets(struct xdp_ring_offset_v1 *ring) 1155 { 1156 ring->producer = offsetof(struct xdp_umem_ring, ptrs.producer); 1157 ring->consumer = offsetof(struct xdp_umem_ring, ptrs.consumer); 1158 ring->desc = offsetof(struct xdp_umem_ring, desc); 1159 } 1160 1161 struct xdp_statistics_v1 { 1162 __u64 rx_dropped; 1163 __u64 rx_invalid_descs; 1164 __u64 tx_invalid_descs; 1165 }; 1166 1167 static int xsk_getsockopt(struct socket *sock, int level, int optname, 1168 char __user *optval, int __user *optlen) 1169 { 1170 struct sock *sk = sock->sk; 1171 struct xdp_sock *xs = xdp_sk(sk); 1172 int len; 1173 1174 if (level != SOL_XDP) 1175 return -ENOPROTOOPT; 1176 1177 if (get_user(len, optlen)) 1178 return -EFAULT; 1179 if (len < 0) 1180 return -EINVAL; 1181 1182 switch (optname) { 1183 case XDP_STATISTICS: 1184 { 1185 struct xdp_statistics stats = {}; 1186 bool extra_stats = true; 1187 size_t stats_size; 1188 1189 if (len < sizeof(struct xdp_statistics_v1)) { 1190 return -EINVAL; 1191 } else if (len < sizeof(stats)) { 1192 extra_stats = false; 1193 stats_size = sizeof(struct xdp_statistics_v1); 1194 } else { 1195 stats_size = sizeof(stats); 1196 } 1197 1198 mutex_lock(&xs->mutex); 1199 stats.rx_dropped = xs->rx_dropped; 1200 if (extra_stats) { 1201 stats.rx_ring_full = xs->rx_queue_full; 1202 stats.rx_fill_ring_empty_descs = 1203 xs->pool ? xskq_nb_queue_empty_descs(xs->pool->fq) : 0; 1204 stats.tx_ring_empty_descs = xskq_nb_queue_empty_descs(xs->tx); 1205 } else { 1206 stats.rx_dropped += xs->rx_queue_full; 1207 } 1208 stats.rx_invalid_descs = xskq_nb_invalid_descs(xs->rx); 1209 stats.tx_invalid_descs = xskq_nb_invalid_descs(xs->tx); 1210 mutex_unlock(&xs->mutex); 1211 1212 if (copy_to_user(optval, &stats, stats_size)) 1213 return -EFAULT; 1214 if (put_user(stats_size, optlen)) 1215 return -EFAULT; 1216 1217 return 0; 1218 } 1219 case XDP_MMAP_OFFSETS: 1220 { 1221 struct xdp_mmap_offsets off; 1222 struct xdp_mmap_offsets_v1 off_v1; 1223 bool flags_supported = true; 1224 void *to_copy; 1225 1226 if (len < sizeof(off_v1)) 1227 return -EINVAL; 1228 else if (len < sizeof(off)) 1229 flags_supported = false; 1230 1231 if (flags_supported) { 1232 /* xdp_ring_offset is identical to xdp_ring_offset_v1 1233 * except for the flags field added to the end. 1234 */ 1235 xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *) 1236 &off.rx); 1237 xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *) 1238 &off.tx); 1239 xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *) 1240 &off.fr); 1241 xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *) 1242 &off.cr); 1243 off.rx.flags = offsetof(struct xdp_rxtx_ring, 1244 ptrs.flags); 1245 off.tx.flags = offsetof(struct xdp_rxtx_ring, 1246 ptrs.flags); 1247 off.fr.flags = offsetof(struct xdp_umem_ring, 1248 ptrs.flags); 1249 off.cr.flags = offsetof(struct xdp_umem_ring, 1250 ptrs.flags); 1251 1252 len = sizeof(off); 1253 to_copy = &off; 1254 } else { 1255 xsk_enter_rxtx_offsets(&off_v1.rx); 1256 xsk_enter_rxtx_offsets(&off_v1.tx); 1257 xsk_enter_umem_offsets(&off_v1.fr); 1258 xsk_enter_umem_offsets(&off_v1.cr); 1259 1260 len = sizeof(off_v1); 1261 to_copy = &off_v1; 1262 } 1263 1264 if (copy_to_user(optval, to_copy, len)) 1265 return -EFAULT; 1266 if (put_user(len, optlen)) 1267 return -EFAULT; 1268 1269 return 0; 1270 } 1271 case XDP_OPTIONS: 1272 { 1273 struct xdp_options opts = {}; 1274 1275 if (len < sizeof(opts)) 1276 return -EINVAL; 1277 1278 mutex_lock(&xs->mutex); 1279 if (xs->zc) 1280 opts.flags |= XDP_OPTIONS_ZEROCOPY; 1281 mutex_unlock(&xs->mutex); 1282 1283 len = sizeof(opts); 1284 if (copy_to_user(optval, &opts, len)) 1285 return -EFAULT; 1286 if (put_user(len, optlen)) 1287 return -EFAULT; 1288 1289 return 0; 1290 } 1291 default: 1292 break; 1293 } 1294 1295 return -EOPNOTSUPP; 1296 } 1297 1298 static int xsk_mmap(struct file *file, struct socket *sock, 1299 struct vm_area_struct *vma) 1300 { 1301 loff_t offset = (loff_t)vma->vm_pgoff << PAGE_SHIFT; 1302 unsigned long size = vma->vm_end - vma->vm_start; 1303 struct xdp_sock *xs = xdp_sk(sock->sk); 1304 int state = READ_ONCE(xs->state); 1305 struct xsk_queue *q = NULL; 1306 1307 if (state != XSK_READY && state != XSK_BOUND) 1308 return -EBUSY; 1309 1310 if (offset == XDP_PGOFF_RX_RING) { 1311 q = READ_ONCE(xs->rx); 1312 } else if (offset == XDP_PGOFF_TX_RING) { 1313 q = READ_ONCE(xs->tx); 1314 } else { 1315 /* Matches the smp_wmb() in XDP_UMEM_REG */ 1316 smp_rmb(); 1317 if (offset == XDP_UMEM_PGOFF_FILL_RING) 1318 q = state == XSK_READY ? READ_ONCE(xs->fq_tmp) : 1319 READ_ONCE(xs->pool->fq); 1320 else if (offset == XDP_UMEM_PGOFF_COMPLETION_RING) 1321 q = state == XSK_READY ? READ_ONCE(xs->cq_tmp) : 1322 READ_ONCE(xs->pool->cq); 1323 } 1324 1325 if (!q) 1326 return -EINVAL; 1327 1328 /* Matches the smp_wmb() in xsk_init_queue */ 1329 smp_rmb(); 1330 if (size > q->ring_vmalloc_size) 1331 return -EINVAL; 1332 1333 return remap_vmalloc_range(vma, q->ring, 0); 1334 } 1335 1336 static int xsk_notifier(struct notifier_block *this, 1337 unsigned long msg, void *ptr) 1338 { 1339 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1340 struct net *net = dev_net(dev); 1341 struct sock *sk; 1342 1343 switch (msg) { 1344 case NETDEV_UNREGISTER: 1345 mutex_lock(&net->xdp.lock); 1346 sk_for_each(sk, &net->xdp.list) { 1347 struct xdp_sock *xs = xdp_sk(sk); 1348 1349 mutex_lock(&xs->mutex); 1350 if (xs->dev == dev) { 1351 sk->sk_err = ENETDOWN; 1352 if (!sock_flag(sk, SOCK_DEAD)) 1353 sk_error_report(sk); 1354 1355 xsk_unbind_dev(xs); 1356 1357 /* Clear device references. */ 1358 xp_clear_dev(xs->pool); 1359 } 1360 mutex_unlock(&xs->mutex); 1361 } 1362 mutex_unlock(&net->xdp.lock); 1363 break; 1364 } 1365 return NOTIFY_DONE; 1366 } 1367 1368 static struct proto xsk_proto = { 1369 .name = "XDP", 1370 .owner = THIS_MODULE, 1371 .obj_size = sizeof(struct xdp_sock), 1372 }; 1373 1374 static const struct proto_ops xsk_proto_ops = { 1375 .family = PF_XDP, 1376 .owner = THIS_MODULE, 1377 .release = xsk_release, 1378 .bind = xsk_bind, 1379 .connect = sock_no_connect, 1380 .socketpair = sock_no_socketpair, 1381 .accept = sock_no_accept, 1382 .getname = sock_no_getname, 1383 .poll = xsk_poll, 1384 .ioctl = sock_no_ioctl, 1385 .listen = sock_no_listen, 1386 .shutdown = sock_no_shutdown, 1387 .setsockopt = xsk_setsockopt, 1388 .getsockopt = xsk_getsockopt, 1389 .sendmsg = xsk_sendmsg, 1390 .recvmsg = xsk_recvmsg, 1391 .mmap = xsk_mmap, 1392 .sendpage = sock_no_sendpage, 1393 }; 1394 1395 static void xsk_destruct(struct sock *sk) 1396 { 1397 struct xdp_sock *xs = xdp_sk(sk); 1398 1399 if (!sock_flag(sk, SOCK_DEAD)) 1400 return; 1401 1402 if (!xp_put_pool(xs->pool)) 1403 xdp_put_umem(xs->umem, !xs->pool); 1404 } 1405 1406 static int xsk_create(struct net *net, struct socket *sock, int protocol, 1407 int kern) 1408 { 1409 struct xdp_sock *xs; 1410 struct sock *sk; 1411 1412 if (!ns_capable(net->user_ns, CAP_NET_RAW)) 1413 return -EPERM; 1414 if (sock->type != SOCK_RAW) 1415 return -ESOCKTNOSUPPORT; 1416 1417 if (protocol) 1418 return -EPROTONOSUPPORT; 1419 1420 sock->state = SS_UNCONNECTED; 1421 1422 sk = sk_alloc(net, PF_XDP, GFP_KERNEL, &xsk_proto, kern); 1423 if (!sk) 1424 return -ENOBUFS; 1425 1426 sock->ops = &xsk_proto_ops; 1427 1428 sock_init_data(sock, sk); 1429 1430 sk->sk_family = PF_XDP; 1431 1432 sk->sk_destruct = xsk_destruct; 1433 1434 sock_set_flag(sk, SOCK_RCU_FREE); 1435 1436 xs = xdp_sk(sk); 1437 xs->state = XSK_READY; 1438 mutex_init(&xs->mutex); 1439 spin_lock_init(&xs->rx_lock); 1440 1441 INIT_LIST_HEAD(&xs->map_list); 1442 spin_lock_init(&xs->map_list_lock); 1443 1444 mutex_lock(&net->xdp.lock); 1445 sk_add_node_rcu(sk, &net->xdp.list); 1446 mutex_unlock(&net->xdp.lock); 1447 1448 sock_prot_inuse_add(net, &xsk_proto, 1); 1449 1450 return 0; 1451 } 1452 1453 static const struct net_proto_family xsk_family_ops = { 1454 .family = PF_XDP, 1455 .create = xsk_create, 1456 .owner = THIS_MODULE, 1457 }; 1458 1459 static struct notifier_block xsk_netdev_notifier = { 1460 .notifier_call = xsk_notifier, 1461 }; 1462 1463 static int __net_init xsk_net_init(struct net *net) 1464 { 1465 mutex_init(&net->xdp.lock); 1466 INIT_HLIST_HEAD(&net->xdp.list); 1467 return 0; 1468 } 1469 1470 static void __net_exit xsk_net_exit(struct net *net) 1471 { 1472 WARN_ON_ONCE(!hlist_empty(&net->xdp.list)); 1473 } 1474 1475 static struct pernet_operations xsk_net_ops = { 1476 .init = xsk_net_init, 1477 .exit = xsk_net_exit, 1478 }; 1479 1480 static int __init xsk_init(void) 1481 { 1482 int err, cpu; 1483 1484 err = proto_register(&xsk_proto, 0 /* no slab */); 1485 if (err) 1486 goto out; 1487 1488 err = sock_register(&xsk_family_ops); 1489 if (err) 1490 goto out_proto; 1491 1492 err = register_pernet_subsys(&xsk_net_ops); 1493 if (err) 1494 goto out_sk; 1495 1496 err = register_netdevice_notifier(&xsk_netdev_notifier); 1497 if (err) 1498 goto out_pernet; 1499 1500 for_each_possible_cpu(cpu) 1501 INIT_LIST_HEAD(&per_cpu(xskmap_flush_list, cpu)); 1502 return 0; 1503 1504 out_pernet: 1505 unregister_pernet_subsys(&xsk_net_ops); 1506 out_sk: 1507 sock_unregister(PF_XDP); 1508 out_proto: 1509 proto_unregister(&xsk_proto); 1510 out: 1511 return err; 1512 } 1513 1514 fs_initcall(xsk_init); 1515