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/xdp.h> 27 28 #include "xsk_queue.h" 29 #include "xdp_umem.h" 30 #include "xsk.h" 31 32 #define TX_BATCH_SIZE 16 33 34 static DEFINE_PER_CPU(struct list_head, xskmap_flush_list); 35 36 void xsk_set_rx_need_wakeup(struct xsk_buff_pool *pool) 37 { 38 if (pool->cached_need_wakeup & XDP_WAKEUP_RX) 39 return; 40 41 pool->fq->ring->flags |= XDP_RING_NEED_WAKEUP; 42 pool->cached_need_wakeup |= XDP_WAKEUP_RX; 43 } 44 EXPORT_SYMBOL(xsk_set_rx_need_wakeup); 45 46 void xsk_set_tx_need_wakeup(struct xsk_buff_pool *pool) 47 { 48 struct xdp_sock *xs; 49 50 if (pool->cached_need_wakeup & XDP_WAKEUP_TX) 51 return; 52 53 rcu_read_lock(); 54 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) { 55 xs->tx->ring->flags |= XDP_RING_NEED_WAKEUP; 56 } 57 rcu_read_unlock(); 58 59 pool->cached_need_wakeup |= XDP_WAKEUP_TX; 60 } 61 EXPORT_SYMBOL(xsk_set_tx_need_wakeup); 62 63 void xsk_clear_rx_need_wakeup(struct xsk_buff_pool *pool) 64 { 65 if (!(pool->cached_need_wakeup & XDP_WAKEUP_RX)) 66 return; 67 68 pool->fq->ring->flags &= ~XDP_RING_NEED_WAKEUP; 69 pool->cached_need_wakeup &= ~XDP_WAKEUP_RX; 70 } 71 EXPORT_SYMBOL(xsk_clear_rx_need_wakeup); 72 73 void xsk_clear_tx_need_wakeup(struct xsk_buff_pool *pool) 74 { 75 struct xdp_sock *xs; 76 77 if (!(pool->cached_need_wakeup & XDP_WAKEUP_TX)) 78 return; 79 80 rcu_read_lock(); 81 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) { 82 xs->tx->ring->flags &= ~XDP_RING_NEED_WAKEUP; 83 } 84 rcu_read_unlock(); 85 86 pool->cached_need_wakeup &= ~XDP_WAKEUP_TX; 87 } 88 EXPORT_SYMBOL(xsk_clear_tx_need_wakeup); 89 90 bool xsk_uses_need_wakeup(struct xsk_buff_pool *pool) 91 { 92 return pool->uses_need_wakeup; 93 } 94 EXPORT_SYMBOL(xsk_uses_need_wakeup); 95 96 struct xsk_buff_pool *xsk_get_pool_from_qid(struct net_device *dev, 97 u16 queue_id) 98 { 99 if (queue_id < dev->real_num_rx_queues) 100 return dev->_rx[queue_id].pool; 101 if (queue_id < dev->real_num_tx_queues) 102 return dev->_tx[queue_id].pool; 103 104 return NULL; 105 } 106 EXPORT_SYMBOL(xsk_get_pool_from_qid); 107 108 void xsk_clear_pool_at_qid(struct net_device *dev, u16 queue_id) 109 { 110 if (queue_id < dev->real_num_rx_queues) 111 dev->_rx[queue_id].pool = NULL; 112 if (queue_id < dev->real_num_tx_queues) 113 dev->_tx[queue_id].pool = NULL; 114 } 115 116 /* The buffer pool is stored both in the _rx struct and the _tx struct as we do 117 * not know if the device has more tx queues than rx, or the opposite. 118 * This might also change during run time. 119 */ 120 int xsk_reg_pool_at_qid(struct net_device *dev, struct xsk_buff_pool *pool, 121 u16 queue_id) 122 { 123 if (queue_id >= max_t(unsigned int, 124 dev->real_num_rx_queues, 125 dev->real_num_tx_queues)) 126 return -EINVAL; 127 128 if (queue_id < dev->real_num_rx_queues) 129 dev->_rx[queue_id].pool = pool; 130 if (queue_id < dev->real_num_tx_queues) 131 dev->_tx[queue_id].pool = pool; 132 133 return 0; 134 } 135 136 void xp_release(struct xdp_buff_xsk *xskb) 137 { 138 xskb->pool->free_heads[xskb->pool->free_heads_cnt++] = xskb; 139 } 140 141 static u64 xp_get_handle(struct xdp_buff_xsk *xskb) 142 { 143 u64 offset = xskb->xdp.data - xskb->xdp.data_hard_start; 144 145 offset += xskb->pool->headroom; 146 if (!xskb->pool->unaligned) 147 return xskb->orig_addr + offset; 148 return xskb->orig_addr + (offset << XSK_UNALIGNED_BUF_OFFSET_SHIFT); 149 } 150 151 static int __xsk_rcv_zc(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len) 152 { 153 struct xdp_buff_xsk *xskb = container_of(xdp, struct xdp_buff_xsk, xdp); 154 u64 addr; 155 int err; 156 157 addr = xp_get_handle(xskb); 158 err = xskq_prod_reserve_desc(xs->rx, addr, len); 159 if (err) { 160 xs->rx_queue_full++; 161 return err; 162 } 163 164 xp_release(xskb); 165 return 0; 166 } 167 168 static void xsk_copy_xdp(struct xdp_buff *to, struct xdp_buff *from, u32 len) 169 { 170 void *from_buf, *to_buf; 171 u32 metalen; 172 173 if (unlikely(xdp_data_meta_unsupported(from))) { 174 from_buf = from->data; 175 to_buf = to->data; 176 metalen = 0; 177 } else { 178 from_buf = from->data_meta; 179 metalen = from->data - from->data_meta; 180 to_buf = to->data - metalen; 181 } 182 183 memcpy(to_buf, from_buf, len + metalen); 184 } 185 186 static int __xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len, 187 bool explicit_free) 188 { 189 struct xdp_buff *xsk_xdp; 190 int err; 191 192 if (len > xsk_pool_get_rx_frame_size(xs->pool)) { 193 xs->rx_dropped++; 194 return -ENOSPC; 195 } 196 197 xsk_xdp = xsk_buff_alloc(xs->pool); 198 if (!xsk_xdp) { 199 xs->rx_dropped++; 200 return -ENOSPC; 201 } 202 203 xsk_copy_xdp(xsk_xdp, xdp, len); 204 err = __xsk_rcv_zc(xs, xsk_xdp, len); 205 if (err) { 206 xsk_buff_free(xsk_xdp); 207 return err; 208 } 209 if (explicit_free) 210 xdp_return_buff(xdp); 211 return 0; 212 } 213 214 static bool xsk_is_bound(struct xdp_sock *xs) 215 { 216 if (READ_ONCE(xs->state) == XSK_BOUND) { 217 /* Matches smp_wmb() in bind(). */ 218 smp_rmb(); 219 return true; 220 } 221 return false; 222 } 223 224 static int xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp, 225 bool explicit_free) 226 { 227 u32 len; 228 229 if (!xsk_is_bound(xs)) 230 return -EINVAL; 231 232 if (xs->dev != xdp->rxq->dev || xs->queue_id != xdp->rxq->queue_index) 233 return -EINVAL; 234 235 len = xdp->data_end - xdp->data; 236 237 return xdp->rxq->mem.type == MEM_TYPE_XSK_BUFF_POOL ? 238 __xsk_rcv_zc(xs, xdp, len) : 239 __xsk_rcv(xs, xdp, len, explicit_free); 240 } 241 242 static void xsk_flush(struct xdp_sock *xs) 243 { 244 xskq_prod_submit(xs->rx); 245 __xskq_cons_release(xs->pool->fq); 246 sock_def_readable(&xs->sk); 247 } 248 249 int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp) 250 { 251 int err; 252 253 spin_lock_bh(&xs->rx_lock); 254 err = xsk_rcv(xs, xdp, false); 255 xsk_flush(xs); 256 spin_unlock_bh(&xs->rx_lock); 257 return err; 258 } 259 260 int __xsk_map_redirect(struct xdp_sock *xs, struct xdp_buff *xdp) 261 { 262 struct list_head *flush_list = this_cpu_ptr(&xskmap_flush_list); 263 int err; 264 265 err = xsk_rcv(xs, xdp, true); 266 if (err) 267 return err; 268 269 if (!xs->flush_node.prev) 270 list_add(&xs->flush_node, flush_list); 271 272 return 0; 273 } 274 275 void __xsk_map_flush(void) 276 { 277 struct list_head *flush_list = this_cpu_ptr(&xskmap_flush_list); 278 struct xdp_sock *xs, *tmp; 279 280 list_for_each_entry_safe(xs, tmp, flush_list, flush_node) { 281 xsk_flush(xs); 282 __list_del_clearprev(&xs->flush_node); 283 } 284 } 285 286 void xsk_tx_completed(struct xsk_buff_pool *pool, u32 nb_entries) 287 { 288 xskq_prod_submit_n(pool->cq, nb_entries); 289 } 290 EXPORT_SYMBOL(xsk_tx_completed); 291 292 void xsk_tx_release(struct xsk_buff_pool *pool) 293 { 294 struct xdp_sock *xs; 295 296 rcu_read_lock(); 297 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) { 298 __xskq_cons_release(xs->tx); 299 xs->sk.sk_write_space(&xs->sk); 300 } 301 rcu_read_unlock(); 302 } 303 EXPORT_SYMBOL(xsk_tx_release); 304 305 bool xsk_tx_peek_desc(struct xsk_buff_pool *pool, struct xdp_desc *desc) 306 { 307 struct xdp_sock *xs; 308 309 rcu_read_lock(); 310 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) { 311 if (!xskq_cons_peek_desc(xs->tx, desc, pool)) { 312 xs->tx->queue_empty_descs++; 313 continue; 314 } 315 316 /* This is the backpressure mechanism for the Tx path. 317 * Reserve space in the completion queue and only proceed 318 * if there is space in it. This avoids having to implement 319 * any buffering in the Tx path. 320 */ 321 if (xskq_prod_reserve_addr(pool->cq, desc->addr)) 322 goto out; 323 324 xskq_cons_release(xs->tx); 325 rcu_read_unlock(); 326 return true; 327 } 328 329 out: 330 rcu_read_unlock(); 331 return false; 332 } 333 EXPORT_SYMBOL(xsk_tx_peek_desc); 334 335 static int xsk_wakeup(struct xdp_sock *xs, u8 flags) 336 { 337 struct net_device *dev = xs->dev; 338 int err; 339 340 rcu_read_lock(); 341 err = dev->netdev_ops->ndo_xsk_wakeup(dev, xs->queue_id, flags); 342 rcu_read_unlock(); 343 344 return err; 345 } 346 347 static int xsk_zc_xmit(struct xdp_sock *xs) 348 { 349 return xsk_wakeup(xs, XDP_WAKEUP_TX); 350 } 351 352 static void xsk_destruct_skb(struct sk_buff *skb) 353 { 354 u64 addr = (u64)(long)skb_shinfo(skb)->destructor_arg; 355 struct xdp_sock *xs = xdp_sk(skb->sk); 356 unsigned long flags; 357 358 spin_lock_irqsave(&xs->tx_completion_lock, flags); 359 xskq_prod_submit_addr(xs->pool->cq, addr); 360 spin_unlock_irqrestore(&xs->tx_completion_lock, flags); 361 362 sock_wfree(skb); 363 } 364 365 static int xsk_generic_xmit(struct sock *sk) 366 { 367 struct xdp_sock *xs = xdp_sk(sk); 368 u32 max_batch = TX_BATCH_SIZE; 369 bool sent_frame = false; 370 struct xdp_desc desc; 371 struct sk_buff *skb; 372 int err = 0; 373 374 mutex_lock(&xs->mutex); 375 376 if (xs->queue_id >= xs->dev->real_num_tx_queues) 377 goto out; 378 379 while (xskq_cons_peek_desc(xs->tx, &desc, xs->pool)) { 380 char *buffer; 381 u64 addr; 382 u32 len; 383 384 if (max_batch-- == 0) { 385 err = -EAGAIN; 386 goto out; 387 } 388 389 len = desc.len; 390 skb = sock_alloc_send_skb(sk, len, 1, &err); 391 if (unlikely(!skb)) 392 goto out; 393 394 skb_put(skb, len); 395 addr = desc.addr; 396 buffer = xsk_buff_raw_get_data(xs->pool, addr); 397 err = skb_store_bits(skb, 0, buffer, len); 398 /* This is the backpressure mechanism for the Tx path. 399 * Reserve space in the completion queue and only proceed 400 * if there is space in it. This avoids having to implement 401 * any buffering in the Tx path. 402 */ 403 if (unlikely(err) || xskq_prod_reserve(xs->pool->cq)) { 404 kfree_skb(skb); 405 goto out; 406 } 407 408 skb->dev = xs->dev; 409 skb->priority = sk->sk_priority; 410 skb->mark = sk->sk_mark; 411 skb_shinfo(skb)->destructor_arg = (void *)(long)desc.addr; 412 skb->destructor = xsk_destruct_skb; 413 414 err = __dev_direct_xmit(skb, xs->queue_id); 415 if (err == NETDEV_TX_BUSY) { 416 /* Tell user-space to retry the send */ 417 skb->destructor = sock_wfree; 418 /* Free skb without triggering the perf drop trace */ 419 consume_skb(skb); 420 err = -EAGAIN; 421 goto out; 422 } 423 424 xskq_cons_release(xs->tx); 425 /* Ignore NET_XMIT_CN as packet might have been sent */ 426 if (err == NET_XMIT_DROP) { 427 /* SKB completed but not sent */ 428 err = -EBUSY; 429 goto out; 430 } 431 432 sent_frame = true; 433 } 434 435 xs->tx->queue_empty_descs++; 436 437 out: 438 if (sent_frame) 439 sk->sk_write_space(sk); 440 441 mutex_unlock(&xs->mutex); 442 return err; 443 } 444 445 static int __xsk_sendmsg(struct sock *sk) 446 { 447 struct xdp_sock *xs = xdp_sk(sk); 448 449 if (unlikely(!(xs->dev->flags & IFF_UP))) 450 return -ENETDOWN; 451 if (unlikely(!xs->tx)) 452 return -ENOBUFS; 453 454 return xs->zc ? xsk_zc_xmit(xs) : xsk_generic_xmit(sk); 455 } 456 457 static int xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len) 458 { 459 bool need_wait = !(m->msg_flags & MSG_DONTWAIT); 460 struct sock *sk = sock->sk; 461 struct xdp_sock *xs = xdp_sk(sk); 462 463 if (unlikely(!xsk_is_bound(xs))) 464 return -ENXIO; 465 if (unlikely(need_wait)) 466 return -EOPNOTSUPP; 467 468 return __xsk_sendmsg(sk); 469 } 470 471 static __poll_t xsk_poll(struct file *file, struct socket *sock, 472 struct poll_table_struct *wait) 473 { 474 __poll_t mask = datagram_poll(file, sock, wait); 475 struct sock *sk = sock->sk; 476 struct xdp_sock *xs = xdp_sk(sk); 477 struct xsk_buff_pool *pool; 478 479 if (unlikely(!xsk_is_bound(xs))) 480 return mask; 481 482 pool = xs->pool; 483 484 if (pool->cached_need_wakeup) { 485 if (xs->zc) 486 xsk_wakeup(xs, pool->cached_need_wakeup); 487 else 488 /* Poll needs to drive Tx also in copy mode */ 489 __xsk_sendmsg(sk); 490 } 491 492 if (xs->rx && !xskq_prod_is_empty(xs->rx)) 493 mask |= EPOLLIN | EPOLLRDNORM; 494 if (xs->tx && !xskq_cons_is_full(xs->tx)) 495 mask |= EPOLLOUT | EPOLLWRNORM; 496 497 return mask; 498 } 499 500 static int xsk_init_queue(u32 entries, struct xsk_queue **queue, 501 bool umem_queue) 502 { 503 struct xsk_queue *q; 504 505 if (entries == 0 || *queue || !is_power_of_2(entries)) 506 return -EINVAL; 507 508 q = xskq_create(entries, umem_queue); 509 if (!q) 510 return -ENOMEM; 511 512 /* Make sure queue is ready before it can be seen by others */ 513 smp_wmb(); 514 WRITE_ONCE(*queue, q); 515 return 0; 516 } 517 518 static void xsk_unbind_dev(struct xdp_sock *xs) 519 { 520 struct net_device *dev = xs->dev; 521 522 if (xs->state != XSK_BOUND) 523 return; 524 WRITE_ONCE(xs->state, XSK_UNBOUND); 525 526 /* Wait for driver to stop using the xdp socket. */ 527 xp_del_xsk(xs->pool, xs); 528 xs->dev = NULL; 529 synchronize_net(); 530 dev_put(dev); 531 } 532 533 static struct xsk_map *xsk_get_map_list_entry(struct xdp_sock *xs, 534 struct xdp_sock ***map_entry) 535 { 536 struct xsk_map *map = NULL; 537 struct xsk_map_node *node; 538 539 *map_entry = NULL; 540 541 spin_lock_bh(&xs->map_list_lock); 542 node = list_first_entry_or_null(&xs->map_list, struct xsk_map_node, 543 node); 544 if (node) { 545 WARN_ON(xsk_map_inc(node->map)); 546 map = node->map; 547 *map_entry = node->map_entry; 548 } 549 spin_unlock_bh(&xs->map_list_lock); 550 return map; 551 } 552 553 static void xsk_delete_from_maps(struct xdp_sock *xs) 554 { 555 /* This function removes the current XDP socket from all the 556 * maps it resides in. We need to take extra care here, due to 557 * the two locks involved. Each map has a lock synchronizing 558 * updates to the entries, and each socket has a lock that 559 * synchronizes access to the list of maps (map_list). For 560 * deadlock avoidance the locks need to be taken in the order 561 * "map lock"->"socket map list lock". We start off by 562 * accessing the socket map list, and take a reference to the 563 * map to guarantee existence between the 564 * xsk_get_map_list_entry() and xsk_map_try_sock_delete() 565 * calls. Then we ask the map to remove the socket, which 566 * tries to remove the socket from the map. Note that there 567 * might be updates to the map between 568 * xsk_get_map_list_entry() and xsk_map_try_sock_delete(). 569 */ 570 struct xdp_sock **map_entry = NULL; 571 struct xsk_map *map; 572 573 while ((map = xsk_get_map_list_entry(xs, &map_entry))) { 574 xsk_map_try_sock_delete(map, xs, map_entry); 575 xsk_map_put(map); 576 } 577 } 578 579 static int xsk_release(struct socket *sock) 580 { 581 struct sock *sk = sock->sk; 582 struct xdp_sock *xs = xdp_sk(sk); 583 struct net *net; 584 585 if (!sk) 586 return 0; 587 588 net = sock_net(sk); 589 590 mutex_lock(&net->xdp.lock); 591 sk_del_node_init_rcu(sk); 592 mutex_unlock(&net->xdp.lock); 593 594 local_bh_disable(); 595 sock_prot_inuse_add(net, sk->sk_prot, -1); 596 local_bh_enable(); 597 598 xsk_delete_from_maps(xs); 599 mutex_lock(&xs->mutex); 600 xsk_unbind_dev(xs); 601 mutex_unlock(&xs->mutex); 602 603 xskq_destroy(xs->rx); 604 xskq_destroy(xs->tx); 605 xskq_destroy(xs->fq_tmp); 606 xskq_destroy(xs->cq_tmp); 607 608 sock_orphan(sk); 609 sock->sk = NULL; 610 611 sk_refcnt_debug_release(sk); 612 sock_put(sk); 613 614 return 0; 615 } 616 617 static struct socket *xsk_lookup_xsk_from_fd(int fd) 618 { 619 struct socket *sock; 620 int err; 621 622 sock = sockfd_lookup(fd, &err); 623 if (!sock) 624 return ERR_PTR(-ENOTSOCK); 625 626 if (sock->sk->sk_family != PF_XDP) { 627 sockfd_put(sock); 628 return ERR_PTR(-ENOPROTOOPT); 629 } 630 631 return sock; 632 } 633 634 static bool xsk_validate_queues(struct xdp_sock *xs) 635 { 636 return xs->fq_tmp && xs->cq_tmp; 637 } 638 639 static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len) 640 { 641 struct sockaddr_xdp *sxdp = (struct sockaddr_xdp *)addr; 642 struct sock *sk = sock->sk; 643 struct xdp_sock *xs = xdp_sk(sk); 644 struct net_device *dev; 645 u32 flags, qid; 646 int err = 0; 647 648 if (addr_len < sizeof(struct sockaddr_xdp)) 649 return -EINVAL; 650 if (sxdp->sxdp_family != AF_XDP) 651 return -EINVAL; 652 653 flags = sxdp->sxdp_flags; 654 if (flags & ~(XDP_SHARED_UMEM | XDP_COPY | XDP_ZEROCOPY | 655 XDP_USE_NEED_WAKEUP)) 656 return -EINVAL; 657 658 rtnl_lock(); 659 mutex_lock(&xs->mutex); 660 if (xs->state != XSK_READY) { 661 err = -EBUSY; 662 goto out_release; 663 } 664 665 dev = dev_get_by_index(sock_net(sk), sxdp->sxdp_ifindex); 666 if (!dev) { 667 err = -ENODEV; 668 goto out_release; 669 } 670 671 if (!xs->rx && !xs->tx) { 672 err = -EINVAL; 673 goto out_unlock; 674 } 675 676 qid = sxdp->sxdp_queue_id; 677 678 if (flags & XDP_SHARED_UMEM) { 679 struct xdp_sock *umem_xs; 680 struct socket *sock; 681 682 if ((flags & XDP_COPY) || (flags & XDP_ZEROCOPY) || 683 (flags & XDP_USE_NEED_WAKEUP)) { 684 /* Cannot specify flags for shared sockets. */ 685 err = -EINVAL; 686 goto out_unlock; 687 } 688 689 if (xs->umem) { 690 /* We have already our own. */ 691 err = -EINVAL; 692 goto out_unlock; 693 } 694 695 sock = xsk_lookup_xsk_from_fd(sxdp->sxdp_shared_umem_fd); 696 if (IS_ERR(sock)) { 697 err = PTR_ERR(sock); 698 goto out_unlock; 699 } 700 701 umem_xs = xdp_sk(sock->sk); 702 if (!xsk_is_bound(umem_xs)) { 703 err = -EBADF; 704 sockfd_put(sock); 705 goto out_unlock; 706 } 707 708 if (umem_xs->queue_id != qid || umem_xs->dev != dev) { 709 /* Share the umem with another socket on another qid 710 * and/or device. 711 */ 712 xs->pool = xp_create_and_assign_umem(xs, 713 umem_xs->umem); 714 if (!xs->pool) { 715 err = -ENOMEM; 716 sockfd_put(sock); 717 goto out_unlock; 718 } 719 720 err = xp_assign_dev_shared(xs->pool, umem_xs->umem, 721 dev, qid); 722 if (err) { 723 xp_destroy(xs->pool); 724 xs->pool = NULL; 725 sockfd_put(sock); 726 goto out_unlock; 727 } 728 } else { 729 /* Share the buffer pool with the other socket. */ 730 if (xs->fq_tmp || xs->cq_tmp) { 731 /* Do not allow setting your own fq or cq. */ 732 err = -EINVAL; 733 sockfd_put(sock); 734 goto out_unlock; 735 } 736 737 xp_get_pool(umem_xs->pool); 738 xs->pool = umem_xs->pool; 739 } 740 741 xdp_get_umem(umem_xs->umem); 742 WRITE_ONCE(xs->umem, umem_xs->umem); 743 sockfd_put(sock); 744 } else if (!xs->umem || !xsk_validate_queues(xs)) { 745 err = -EINVAL; 746 goto out_unlock; 747 } else { 748 /* This xsk has its own umem. */ 749 xs->pool = xp_create_and_assign_umem(xs, xs->umem); 750 if (!xs->pool) { 751 err = -ENOMEM; 752 goto out_unlock; 753 } 754 755 err = xp_assign_dev(xs->pool, dev, qid, flags); 756 if (err) { 757 xp_destroy(xs->pool); 758 xs->pool = NULL; 759 goto out_unlock; 760 } 761 } 762 763 xs->dev = dev; 764 xs->zc = xs->umem->zc; 765 xs->queue_id = qid; 766 xp_add_xsk(xs->pool, xs); 767 768 out_unlock: 769 if (err) { 770 dev_put(dev); 771 } else { 772 /* Matches smp_rmb() in bind() for shared umem 773 * sockets, and xsk_is_bound(). 774 */ 775 smp_wmb(); 776 WRITE_ONCE(xs->state, XSK_BOUND); 777 } 778 out_release: 779 mutex_unlock(&xs->mutex); 780 rtnl_unlock(); 781 return err; 782 } 783 784 struct xdp_umem_reg_v1 { 785 __u64 addr; /* Start of packet data area */ 786 __u64 len; /* Length of packet data area */ 787 __u32 chunk_size; 788 __u32 headroom; 789 }; 790 791 static int xsk_setsockopt(struct socket *sock, int level, int optname, 792 sockptr_t optval, unsigned int optlen) 793 { 794 struct sock *sk = sock->sk; 795 struct xdp_sock *xs = xdp_sk(sk); 796 int err; 797 798 if (level != SOL_XDP) 799 return -ENOPROTOOPT; 800 801 switch (optname) { 802 case XDP_RX_RING: 803 case XDP_TX_RING: 804 { 805 struct xsk_queue **q; 806 int entries; 807 808 if (optlen < sizeof(entries)) 809 return -EINVAL; 810 if (copy_from_sockptr(&entries, optval, sizeof(entries))) 811 return -EFAULT; 812 813 mutex_lock(&xs->mutex); 814 if (xs->state != XSK_READY) { 815 mutex_unlock(&xs->mutex); 816 return -EBUSY; 817 } 818 q = (optname == XDP_TX_RING) ? &xs->tx : &xs->rx; 819 err = xsk_init_queue(entries, q, false); 820 if (!err && optname == XDP_TX_RING) 821 /* Tx needs to be explicitly woken up the first time */ 822 xs->tx->ring->flags |= XDP_RING_NEED_WAKEUP; 823 mutex_unlock(&xs->mutex); 824 return err; 825 } 826 case XDP_UMEM_REG: 827 { 828 size_t mr_size = sizeof(struct xdp_umem_reg); 829 struct xdp_umem_reg mr = {}; 830 struct xdp_umem *umem; 831 832 if (optlen < sizeof(struct xdp_umem_reg_v1)) 833 return -EINVAL; 834 else if (optlen < sizeof(mr)) 835 mr_size = sizeof(struct xdp_umem_reg_v1); 836 837 if (copy_from_sockptr(&mr, optval, mr_size)) 838 return -EFAULT; 839 840 mutex_lock(&xs->mutex); 841 if (xs->state != XSK_READY || xs->umem) { 842 mutex_unlock(&xs->mutex); 843 return -EBUSY; 844 } 845 846 umem = xdp_umem_create(&mr); 847 if (IS_ERR(umem)) { 848 mutex_unlock(&xs->mutex); 849 return PTR_ERR(umem); 850 } 851 852 /* Make sure umem is ready before it can be seen by others */ 853 smp_wmb(); 854 WRITE_ONCE(xs->umem, umem); 855 mutex_unlock(&xs->mutex); 856 return 0; 857 } 858 case XDP_UMEM_FILL_RING: 859 case XDP_UMEM_COMPLETION_RING: 860 { 861 struct xsk_queue **q; 862 int entries; 863 864 if (copy_from_sockptr(&entries, optval, sizeof(entries))) 865 return -EFAULT; 866 867 mutex_lock(&xs->mutex); 868 if (xs->state != XSK_READY) { 869 mutex_unlock(&xs->mutex); 870 return -EBUSY; 871 } 872 873 q = (optname == XDP_UMEM_FILL_RING) ? &xs->fq_tmp : 874 &xs->cq_tmp; 875 err = xsk_init_queue(entries, q, true); 876 mutex_unlock(&xs->mutex); 877 return err; 878 } 879 default: 880 break; 881 } 882 883 return -ENOPROTOOPT; 884 } 885 886 static void xsk_enter_rxtx_offsets(struct xdp_ring_offset_v1 *ring) 887 { 888 ring->producer = offsetof(struct xdp_rxtx_ring, ptrs.producer); 889 ring->consumer = offsetof(struct xdp_rxtx_ring, ptrs.consumer); 890 ring->desc = offsetof(struct xdp_rxtx_ring, desc); 891 } 892 893 static void xsk_enter_umem_offsets(struct xdp_ring_offset_v1 *ring) 894 { 895 ring->producer = offsetof(struct xdp_umem_ring, ptrs.producer); 896 ring->consumer = offsetof(struct xdp_umem_ring, ptrs.consumer); 897 ring->desc = offsetof(struct xdp_umem_ring, desc); 898 } 899 900 struct xdp_statistics_v1 { 901 __u64 rx_dropped; 902 __u64 rx_invalid_descs; 903 __u64 tx_invalid_descs; 904 }; 905 906 static int xsk_getsockopt(struct socket *sock, int level, int optname, 907 char __user *optval, int __user *optlen) 908 { 909 struct sock *sk = sock->sk; 910 struct xdp_sock *xs = xdp_sk(sk); 911 int len; 912 913 if (level != SOL_XDP) 914 return -ENOPROTOOPT; 915 916 if (get_user(len, optlen)) 917 return -EFAULT; 918 if (len < 0) 919 return -EINVAL; 920 921 switch (optname) { 922 case XDP_STATISTICS: 923 { 924 struct xdp_statistics stats = {}; 925 bool extra_stats = true; 926 size_t stats_size; 927 928 if (len < sizeof(struct xdp_statistics_v1)) { 929 return -EINVAL; 930 } else if (len < sizeof(stats)) { 931 extra_stats = false; 932 stats_size = sizeof(struct xdp_statistics_v1); 933 } else { 934 stats_size = sizeof(stats); 935 } 936 937 mutex_lock(&xs->mutex); 938 stats.rx_dropped = xs->rx_dropped; 939 if (extra_stats) { 940 stats.rx_ring_full = xs->rx_queue_full; 941 stats.rx_fill_ring_empty_descs = 942 xs->pool ? xskq_nb_queue_empty_descs(xs->pool->fq) : 0; 943 stats.tx_ring_empty_descs = xskq_nb_queue_empty_descs(xs->tx); 944 } else { 945 stats.rx_dropped += xs->rx_queue_full; 946 } 947 stats.rx_invalid_descs = xskq_nb_invalid_descs(xs->rx); 948 stats.tx_invalid_descs = xskq_nb_invalid_descs(xs->tx); 949 mutex_unlock(&xs->mutex); 950 951 if (copy_to_user(optval, &stats, stats_size)) 952 return -EFAULT; 953 if (put_user(stats_size, optlen)) 954 return -EFAULT; 955 956 return 0; 957 } 958 case XDP_MMAP_OFFSETS: 959 { 960 struct xdp_mmap_offsets off; 961 struct xdp_mmap_offsets_v1 off_v1; 962 bool flags_supported = true; 963 void *to_copy; 964 965 if (len < sizeof(off_v1)) 966 return -EINVAL; 967 else if (len < sizeof(off)) 968 flags_supported = false; 969 970 if (flags_supported) { 971 /* xdp_ring_offset is identical to xdp_ring_offset_v1 972 * except for the flags field added to the end. 973 */ 974 xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *) 975 &off.rx); 976 xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *) 977 &off.tx); 978 xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *) 979 &off.fr); 980 xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *) 981 &off.cr); 982 off.rx.flags = offsetof(struct xdp_rxtx_ring, 983 ptrs.flags); 984 off.tx.flags = offsetof(struct xdp_rxtx_ring, 985 ptrs.flags); 986 off.fr.flags = offsetof(struct xdp_umem_ring, 987 ptrs.flags); 988 off.cr.flags = offsetof(struct xdp_umem_ring, 989 ptrs.flags); 990 991 len = sizeof(off); 992 to_copy = &off; 993 } else { 994 xsk_enter_rxtx_offsets(&off_v1.rx); 995 xsk_enter_rxtx_offsets(&off_v1.tx); 996 xsk_enter_umem_offsets(&off_v1.fr); 997 xsk_enter_umem_offsets(&off_v1.cr); 998 999 len = sizeof(off_v1); 1000 to_copy = &off_v1; 1001 } 1002 1003 if (copy_to_user(optval, to_copy, len)) 1004 return -EFAULT; 1005 if (put_user(len, optlen)) 1006 return -EFAULT; 1007 1008 return 0; 1009 } 1010 case XDP_OPTIONS: 1011 { 1012 struct xdp_options opts = {}; 1013 1014 if (len < sizeof(opts)) 1015 return -EINVAL; 1016 1017 mutex_lock(&xs->mutex); 1018 if (xs->zc) 1019 opts.flags |= XDP_OPTIONS_ZEROCOPY; 1020 mutex_unlock(&xs->mutex); 1021 1022 len = sizeof(opts); 1023 if (copy_to_user(optval, &opts, len)) 1024 return -EFAULT; 1025 if (put_user(len, optlen)) 1026 return -EFAULT; 1027 1028 return 0; 1029 } 1030 default: 1031 break; 1032 } 1033 1034 return -EOPNOTSUPP; 1035 } 1036 1037 static int xsk_mmap(struct file *file, struct socket *sock, 1038 struct vm_area_struct *vma) 1039 { 1040 loff_t offset = (loff_t)vma->vm_pgoff << PAGE_SHIFT; 1041 unsigned long size = vma->vm_end - vma->vm_start; 1042 struct xdp_sock *xs = xdp_sk(sock->sk); 1043 struct xsk_queue *q = NULL; 1044 unsigned long pfn; 1045 struct page *qpg; 1046 1047 if (READ_ONCE(xs->state) != XSK_READY) 1048 return -EBUSY; 1049 1050 if (offset == XDP_PGOFF_RX_RING) { 1051 q = READ_ONCE(xs->rx); 1052 } else if (offset == XDP_PGOFF_TX_RING) { 1053 q = READ_ONCE(xs->tx); 1054 } else { 1055 /* Matches the smp_wmb() in XDP_UMEM_REG */ 1056 smp_rmb(); 1057 if (offset == XDP_UMEM_PGOFF_FILL_RING) 1058 q = READ_ONCE(xs->fq_tmp); 1059 else if (offset == XDP_UMEM_PGOFF_COMPLETION_RING) 1060 q = READ_ONCE(xs->cq_tmp); 1061 } 1062 1063 if (!q) 1064 return -EINVAL; 1065 1066 /* Matches the smp_wmb() in xsk_init_queue */ 1067 smp_rmb(); 1068 qpg = virt_to_head_page(q->ring); 1069 if (size > page_size(qpg)) 1070 return -EINVAL; 1071 1072 pfn = virt_to_phys(q->ring) >> PAGE_SHIFT; 1073 return remap_pfn_range(vma, vma->vm_start, pfn, 1074 size, vma->vm_page_prot); 1075 } 1076 1077 static int xsk_notifier(struct notifier_block *this, 1078 unsigned long msg, void *ptr) 1079 { 1080 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1081 struct net *net = dev_net(dev); 1082 struct sock *sk; 1083 1084 switch (msg) { 1085 case NETDEV_UNREGISTER: 1086 mutex_lock(&net->xdp.lock); 1087 sk_for_each(sk, &net->xdp.list) { 1088 struct xdp_sock *xs = xdp_sk(sk); 1089 1090 mutex_lock(&xs->mutex); 1091 if (xs->dev == dev) { 1092 sk->sk_err = ENETDOWN; 1093 if (!sock_flag(sk, SOCK_DEAD)) 1094 sk->sk_error_report(sk); 1095 1096 xsk_unbind_dev(xs); 1097 1098 /* Clear device references. */ 1099 xp_clear_dev(xs->pool); 1100 } 1101 mutex_unlock(&xs->mutex); 1102 } 1103 mutex_unlock(&net->xdp.lock); 1104 break; 1105 } 1106 return NOTIFY_DONE; 1107 } 1108 1109 static struct proto xsk_proto = { 1110 .name = "XDP", 1111 .owner = THIS_MODULE, 1112 .obj_size = sizeof(struct xdp_sock), 1113 }; 1114 1115 static const struct proto_ops xsk_proto_ops = { 1116 .family = PF_XDP, 1117 .owner = THIS_MODULE, 1118 .release = xsk_release, 1119 .bind = xsk_bind, 1120 .connect = sock_no_connect, 1121 .socketpair = sock_no_socketpair, 1122 .accept = sock_no_accept, 1123 .getname = sock_no_getname, 1124 .poll = xsk_poll, 1125 .ioctl = sock_no_ioctl, 1126 .listen = sock_no_listen, 1127 .shutdown = sock_no_shutdown, 1128 .setsockopt = xsk_setsockopt, 1129 .getsockopt = xsk_getsockopt, 1130 .sendmsg = xsk_sendmsg, 1131 .recvmsg = sock_no_recvmsg, 1132 .mmap = xsk_mmap, 1133 .sendpage = sock_no_sendpage, 1134 }; 1135 1136 static void xsk_destruct(struct sock *sk) 1137 { 1138 struct xdp_sock *xs = xdp_sk(sk); 1139 1140 if (!sock_flag(sk, SOCK_DEAD)) 1141 return; 1142 1143 if (!xp_put_pool(xs->pool)) 1144 xdp_put_umem(xs->umem, !xs->pool); 1145 1146 sk_refcnt_debug_dec(sk); 1147 } 1148 1149 static int xsk_create(struct net *net, struct socket *sock, int protocol, 1150 int kern) 1151 { 1152 struct xdp_sock *xs; 1153 struct sock *sk; 1154 1155 if (!ns_capable(net->user_ns, CAP_NET_RAW)) 1156 return -EPERM; 1157 if (sock->type != SOCK_RAW) 1158 return -ESOCKTNOSUPPORT; 1159 1160 if (protocol) 1161 return -EPROTONOSUPPORT; 1162 1163 sock->state = SS_UNCONNECTED; 1164 1165 sk = sk_alloc(net, PF_XDP, GFP_KERNEL, &xsk_proto, kern); 1166 if (!sk) 1167 return -ENOBUFS; 1168 1169 sock->ops = &xsk_proto_ops; 1170 1171 sock_init_data(sock, sk); 1172 1173 sk->sk_family = PF_XDP; 1174 1175 sk->sk_destruct = xsk_destruct; 1176 sk_refcnt_debug_inc(sk); 1177 1178 sock_set_flag(sk, SOCK_RCU_FREE); 1179 1180 xs = xdp_sk(sk); 1181 xs->state = XSK_READY; 1182 mutex_init(&xs->mutex); 1183 spin_lock_init(&xs->rx_lock); 1184 spin_lock_init(&xs->tx_completion_lock); 1185 1186 INIT_LIST_HEAD(&xs->map_list); 1187 spin_lock_init(&xs->map_list_lock); 1188 1189 mutex_lock(&net->xdp.lock); 1190 sk_add_node_rcu(sk, &net->xdp.list); 1191 mutex_unlock(&net->xdp.lock); 1192 1193 local_bh_disable(); 1194 sock_prot_inuse_add(net, &xsk_proto, 1); 1195 local_bh_enable(); 1196 1197 return 0; 1198 } 1199 1200 static const struct net_proto_family xsk_family_ops = { 1201 .family = PF_XDP, 1202 .create = xsk_create, 1203 .owner = THIS_MODULE, 1204 }; 1205 1206 static struct notifier_block xsk_netdev_notifier = { 1207 .notifier_call = xsk_notifier, 1208 }; 1209 1210 static int __net_init xsk_net_init(struct net *net) 1211 { 1212 mutex_init(&net->xdp.lock); 1213 INIT_HLIST_HEAD(&net->xdp.list); 1214 return 0; 1215 } 1216 1217 static void __net_exit xsk_net_exit(struct net *net) 1218 { 1219 WARN_ON_ONCE(!hlist_empty(&net->xdp.list)); 1220 } 1221 1222 static struct pernet_operations xsk_net_ops = { 1223 .init = xsk_net_init, 1224 .exit = xsk_net_exit, 1225 }; 1226 1227 static int __init xsk_init(void) 1228 { 1229 int err, cpu; 1230 1231 err = proto_register(&xsk_proto, 0 /* no slab */); 1232 if (err) 1233 goto out; 1234 1235 err = sock_register(&xsk_family_ops); 1236 if (err) 1237 goto out_proto; 1238 1239 err = register_pernet_subsys(&xsk_net_ops); 1240 if (err) 1241 goto out_sk; 1242 1243 err = register_netdevice_notifier(&xsk_netdev_notifier); 1244 if (err) 1245 goto out_pernet; 1246 1247 for_each_possible_cpu(cpu) 1248 INIT_LIST_HEAD(&per_cpu(xskmap_flush_list, cpu)); 1249 return 0; 1250 1251 out_pernet: 1252 unregister_pernet_subsys(&xsk_net_ops); 1253 out_sk: 1254 sock_unregister(PF_XDP); 1255 out_proto: 1256 proto_unregister(&xsk_proto); 1257 out: 1258 return err; 1259 } 1260 1261 fs_initcall(xsk_init); 1262