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