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