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_tx_writeable(struct xdp_sock *xs) 215 { 216 if (xskq_cons_present_entries(xs->tx) > xs->tx->nentries / 2) 217 return false; 218 219 return true; 220 } 221 222 static bool xsk_is_bound(struct xdp_sock *xs) 223 { 224 if (READ_ONCE(xs->state) == XSK_BOUND) { 225 /* Matches smp_wmb() in bind(). */ 226 smp_rmb(); 227 return true; 228 } 229 return false; 230 } 231 232 static int xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp, 233 bool explicit_free) 234 { 235 u32 len; 236 237 if (!xsk_is_bound(xs)) 238 return -EINVAL; 239 240 if (xs->dev != xdp->rxq->dev || xs->queue_id != xdp->rxq->queue_index) 241 return -EINVAL; 242 243 len = xdp->data_end - xdp->data; 244 245 return xdp->rxq->mem.type == MEM_TYPE_XSK_BUFF_POOL ? 246 __xsk_rcv_zc(xs, xdp, len) : 247 __xsk_rcv(xs, xdp, len, explicit_free); 248 } 249 250 static void xsk_flush(struct xdp_sock *xs) 251 { 252 xskq_prod_submit(xs->rx); 253 __xskq_cons_release(xs->pool->fq); 254 sock_def_readable(&xs->sk); 255 } 256 257 int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp) 258 { 259 int err; 260 261 spin_lock_bh(&xs->rx_lock); 262 err = xsk_rcv(xs, xdp, false); 263 xsk_flush(xs); 264 spin_unlock_bh(&xs->rx_lock); 265 return err; 266 } 267 268 int __xsk_map_redirect(struct xdp_sock *xs, struct xdp_buff *xdp) 269 { 270 struct list_head *flush_list = this_cpu_ptr(&xskmap_flush_list); 271 int err; 272 273 err = xsk_rcv(xs, xdp, true); 274 if (err) 275 return err; 276 277 if (!xs->flush_node.prev) 278 list_add(&xs->flush_node, flush_list); 279 280 return 0; 281 } 282 283 void __xsk_map_flush(void) 284 { 285 struct list_head *flush_list = this_cpu_ptr(&xskmap_flush_list); 286 struct xdp_sock *xs, *tmp; 287 288 list_for_each_entry_safe(xs, tmp, flush_list, flush_node) { 289 xsk_flush(xs); 290 __list_del_clearprev(&xs->flush_node); 291 } 292 } 293 294 void xsk_tx_completed(struct xsk_buff_pool *pool, u32 nb_entries) 295 { 296 xskq_prod_submit_n(pool->cq, nb_entries); 297 } 298 EXPORT_SYMBOL(xsk_tx_completed); 299 300 void xsk_tx_release(struct xsk_buff_pool *pool) 301 { 302 struct xdp_sock *xs; 303 304 rcu_read_lock(); 305 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) { 306 __xskq_cons_release(xs->tx); 307 if (xsk_tx_writeable(xs)) 308 xs->sk.sk_write_space(&xs->sk); 309 } 310 rcu_read_unlock(); 311 } 312 EXPORT_SYMBOL(xsk_tx_release); 313 314 bool xsk_tx_peek_desc(struct xsk_buff_pool *pool, struct xdp_desc *desc) 315 { 316 struct xdp_sock *xs; 317 318 rcu_read_lock(); 319 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) { 320 if (!xskq_cons_peek_desc(xs->tx, desc, pool)) { 321 xs->tx->queue_empty_descs++; 322 continue; 323 } 324 325 /* This is the backpressure mechanism for the Tx path. 326 * Reserve space in the completion queue and only proceed 327 * if there is space in it. This avoids having to implement 328 * any buffering in the Tx path. 329 */ 330 if (xskq_prod_reserve_addr(pool->cq, desc->addr)) 331 goto out; 332 333 xskq_cons_release(xs->tx); 334 rcu_read_unlock(); 335 return true; 336 } 337 338 out: 339 rcu_read_unlock(); 340 return false; 341 } 342 EXPORT_SYMBOL(xsk_tx_peek_desc); 343 344 static int xsk_wakeup(struct xdp_sock *xs, u8 flags) 345 { 346 struct net_device *dev = xs->dev; 347 int err; 348 349 rcu_read_lock(); 350 err = dev->netdev_ops->ndo_xsk_wakeup(dev, xs->queue_id, flags); 351 rcu_read_unlock(); 352 353 return err; 354 } 355 356 static int xsk_zc_xmit(struct xdp_sock *xs) 357 { 358 return xsk_wakeup(xs, XDP_WAKEUP_TX); 359 } 360 361 static void xsk_destruct_skb(struct sk_buff *skb) 362 { 363 u64 addr = (u64)(long)skb_shinfo(skb)->destructor_arg; 364 struct xdp_sock *xs = xdp_sk(skb->sk); 365 unsigned long flags; 366 367 spin_lock_irqsave(&xs->tx_completion_lock, flags); 368 xskq_prod_submit_addr(xs->pool->cq, addr); 369 spin_unlock_irqrestore(&xs->tx_completion_lock, flags); 370 371 sock_wfree(skb); 372 } 373 374 static int xsk_generic_xmit(struct sock *sk) 375 { 376 struct xdp_sock *xs = xdp_sk(sk); 377 u32 max_batch = TX_BATCH_SIZE; 378 bool sent_frame = false; 379 struct xdp_desc desc; 380 struct sk_buff *skb; 381 int err = 0; 382 383 mutex_lock(&xs->mutex); 384 385 if (xs->queue_id >= xs->dev->real_num_tx_queues) 386 goto out; 387 388 while (xskq_cons_peek_desc(xs->tx, &desc, xs->pool)) { 389 char *buffer; 390 u64 addr; 391 u32 len; 392 393 if (max_batch-- == 0) { 394 err = -EAGAIN; 395 goto out; 396 } 397 398 len = desc.len; 399 skb = sock_alloc_send_skb(sk, len, 1, &err); 400 if (unlikely(!skb)) 401 goto out; 402 403 skb_put(skb, len); 404 addr = desc.addr; 405 buffer = xsk_buff_raw_get_data(xs->pool, addr); 406 err = skb_store_bits(skb, 0, buffer, len); 407 /* This is the backpressure mechanism for the Tx path. 408 * Reserve space in the completion queue and only proceed 409 * if there is space in it. This avoids having to implement 410 * any buffering in the Tx path. 411 */ 412 if (unlikely(err) || xskq_prod_reserve(xs->pool->cq)) { 413 kfree_skb(skb); 414 goto out; 415 } 416 417 skb->dev = xs->dev; 418 skb->priority = sk->sk_priority; 419 skb->mark = sk->sk_mark; 420 skb_shinfo(skb)->destructor_arg = (void *)(long)desc.addr; 421 skb->destructor = xsk_destruct_skb; 422 423 err = __dev_direct_xmit(skb, xs->queue_id); 424 if (err == NETDEV_TX_BUSY) { 425 /* Tell user-space to retry the send */ 426 skb->destructor = sock_wfree; 427 /* Free skb without triggering the perf drop trace */ 428 consume_skb(skb); 429 err = -EAGAIN; 430 goto out; 431 } 432 433 xskq_cons_release(xs->tx); 434 /* Ignore NET_XMIT_CN as packet might have been sent */ 435 if (err == NET_XMIT_DROP) { 436 /* SKB completed but not sent */ 437 err = -EBUSY; 438 goto out; 439 } 440 441 sent_frame = true; 442 } 443 444 xs->tx->queue_empty_descs++; 445 446 out: 447 if (sent_frame) 448 if (xsk_tx_writeable(xs)) 449 sk->sk_write_space(sk); 450 451 mutex_unlock(&xs->mutex); 452 return err; 453 } 454 455 static int __xsk_sendmsg(struct sock *sk) 456 { 457 struct xdp_sock *xs = xdp_sk(sk); 458 459 if (unlikely(!(xs->dev->flags & IFF_UP))) 460 return -ENETDOWN; 461 if (unlikely(!xs->tx)) 462 return -ENOBUFS; 463 464 return xs->zc ? xsk_zc_xmit(xs) : xsk_generic_xmit(sk); 465 } 466 467 static int xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len) 468 { 469 bool need_wait = !(m->msg_flags & MSG_DONTWAIT); 470 struct sock *sk = sock->sk; 471 struct xdp_sock *xs = xdp_sk(sk); 472 473 if (unlikely(!xsk_is_bound(xs))) 474 return -ENXIO; 475 if (unlikely(need_wait)) 476 return -EOPNOTSUPP; 477 478 return __xsk_sendmsg(sk); 479 } 480 481 static __poll_t xsk_poll(struct file *file, struct socket *sock, 482 struct poll_table_struct *wait) 483 { 484 __poll_t mask = 0; 485 struct sock *sk = sock->sk; 486 struct xdp_sock *xs = xdp_sk(sk); 487 struct xsk_buff_pool *pool; 488 489 sock_poll_wait(file, sock, wait); 490 491 if (unlikely(!xsk_is_bound(xs))) 492 return mask; 493 494 pool = xs->pool; 495 496 if (pool->cached_need_wakeup) { 497 if (xs->zc) 498 xsk_wakeup(xs, pool->cached_need_wakeup); 499 else 500 /* Poll needs to drive Tx also in copy mode */ 501 __xsk_sendmsg(sk); 502 } 503 504 if (xs->rx && !xskq_prod_is_empty(xs->rx)) 505 mask |= EPOLLIN | EPOLLRDNORM; 506 if (xs->tx && xsk_tx_writeable(xs)) 507 mask |= EPOLLOUT | EPOLLWRNORM; 508 509 return mask; 510 } 511 512 static int xsk_init_queue(u32 entries, struct xsk_queue **queue, 513 bool umem_queue) 514 { 515 struct xsk_queue *q; 516 517 if (entries == 0 || *queue || !is_power_of_2(entries)) 518 return -EINVAL; 519 520 q = xskq_create(entries, umem_queue); 521 if (!q) 522 return -ENOMEM; 523 524 /* Make sure queue is ready before it can be seen by others */ 525 smp_wmb(); 526 WRITE_ONCE(*queue, q); 527 return 0; 528 } 529 530 static void xsk_unbind_dev(struct xdp_sock *xs) 531 { 532 struct net_device *dev = xs->dev; 533 534 if (xs->state != XSK_BOUND) 535 return; 536 WRITE_ONCE(xs->state, XSK_UNBOUND); 537 538 /* Wait for driver to stop using the xdp socket. */ 539 xp_del_xsk(xs->pool, xs); 540 xs->dev = NULL; 541 synchronize_net(); 542 dev_put(dev); 543 } 544 545 static struct xsk_map *xsk_get_map_list_entry(struct xdp_sock *xs, 546 struct xdp_sock ***map_entry) 547 { 548 struct xsk_map *map = NULL; 549 struct xsk_map_node *node; 550 551 *map_entry = NULL; 552 553 spin_lock_bh(&xs->map_list_lock); 554 node = list_first_entry_or_null(&xs->map_list, struct xsk_map_node, 555 node); 556 if (node) { 557 WARN_ON(xsk_map_inc(node->map)); 558 map = node->map; 559 *map_entry = node->map_entry; 560 } 561 spin_unlock_bh(&xs->map_list_lock); 562 return map; 563 } 564 565 static void xsk_delete_from_maps(struct xdp_sock *xs) 566 { 567 /* This function removes the current XDP socket from all the 568 * maps it resides in. We need to take extra care here, due to 569 * the two locks involved. Each map has a lock synchronizing 570 * updates to the entries, and each socket has a lock that 571 * synchronizes access to the list of maps (map_list). For 572 * deadlock avoidance the locks need to be taken in the order 573 * "map lock"->"socket map list lock". We start off by 574 * accessing the socket map list, and take a reference to the 575 * map to guarantee existence between the 576 * xsk_get_map_list_entry() and xsk_map_try_sock_delete() 577 * calls. Then we ask the map to remove the socket, which 578 * tries to remove the socket from the map. Note that there 579 * might be updates to the map between 580 * xsk_get_map_list_entry() and xsk_map_try_sock_delete(). 581 */ 582 struct xdp_sock **map_entry = NULL; 583 struct xsk_map *map; 584 585 while ((map = xsk_get_map_list_entry(xs, &map_entry))) { 586 xsk_map_try_sock_delete(map, xs, map_entry); 587 xsk_map_put(map); 588 } 589 } 590 591 static int xsk_release(struct socket *sock) 592 { 593 struct sock *sk = sock->sk; 594 struct xdp_sock *xs = xdp_sk(sk); 595 struct net *net; 596 597 if (!sk) 598 return 0; 599 600 net = sock_net(sk); 601 602 mutex_lock(&net->xdp.lock); 603 sk_del_node_init_rcu(sk); 604 mutex_unlock(&net->xdp.lock); 605 606 local_bh_disable(); 607 sock_prot_inuse_add(net, sk->sk_prot, -1); 608 local_bh_enable(); 609 610 xsk_delete_from_maps(xs); 611 mutex_lock(&xs->mutex); 612 xsk_unbind_dev(xs); 613 mutex_unlock(&xs->mutex); 614 615 xskq_destroy(xs->rx); 616 xskq_destroy(xs->tx); 617 xskq_destroy(xs->fq_tmp); 618 xskq_destroy(xs->cq_tmp); 619 620 sock_orphan(sk); 621 sock->sk = NULL; 622 623 sk_refcnt_debug_release(sk); 624 sock_put(sk); 625 626 return 0; 627 } 628 629 static struct socket *xsk_lookup_xsk_from_fd(int fd) 630 { 631 struct socket *sock; 632 int err; 633 634 sock = sockfd_lookup(fd, &err); 635 if (!sock) 636 return ERR_PTR(-ENOTSOCK); 637 638 if (sock->sk->sk_family != PF_XDP) { 639 sockfd_put(sock); 640 return ERR_PTR(-ENOPROTOOPT); 641 } 642 643 return sock; 644 } 645 646 static bool xsk_validate_queues(struct xdp_sock *xs) 647 { 648 return xs->fq_tmp && xs->cq_tmp; 649 } 650 651 static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len) 652 { 653 struct sockaddr_xdp *sxdp = (struct sockaddr_xdp *)addr; 654 struct sock *sk = sock->sk; 655 struct xdp_sock *xs = xdp_sk(sk); 656 struct net_device *dev; 657 u32 flags, qid; 658 int err = 0; 659 660 if (addr_len < sizeof(struct sockaddr_xdp)) 661 return -EINVAL; 662 if (sxdp->sxdp_family != AF_XDP) 663 return -EINVAL; 664 665 flags = sxdp->sxdp_flags; 666 if (flags & ~(XDP_SHARED_UMEM | XDP_COPY | XDP_ZEROCOPY | 667 XDP_USE_NEED_WAKEUP)) 668 return -EINVAL; 669 670 rtnl_lock(); 671 mutex_lock(&xs->mutex); 672 if (xs->state != XSK_READY) { 673 err = -EBUSY; 674 goto out_release; 675 } 676 677 dev = dev_get_by_index(sock_net(sk), sxdp->sxdp_ifindex); 678 if (!dev) { 679 err = -ENODEV; 680 goto out_release; 681 } 682 683 if (!xs->rx && !xs->tx) { 684 err = -EINVAL; 685 goto out_unlock; 686 } 687 688 qid = sxdp->sxdp_queue_id; 689 690 if (flags & XDP_SHARED_UMEM) { 691 struct xdp_sock *umem_xs; 692 struct socket *sock; 693 694 if ((flags & XDP_COPY) || (flags & XDP_ZEROCOPY) || 695 (flags & XDP_USE_NEED_WAKEUP)) { 696 /* Cannot specify flags for shared sockets. */ 697 err = -EINVAL; 698 goto out_unlock; 699 } 700 701 if (xs->umem) { 702 /* We have already our own. */ 703 err = -EINVAL; 704 goto out_unlock; 705 } 706 707 sock = xsk_lookup_xsk_from_fd(sxdp->sxdp_shared_umem_fd); 708 if (IS_ERR(sock)) { 709 err = PTR_ERR(sock); 710 goto out_unlock; 711 } 712 713 umem_xs = xdp_sk(sock->sk); 714 if (!xsk_is_bound(umem_xs)) { 715 err = -EBADF; 716 sockfd_put(sock); 717 goto out_unlock; 718 } 719 720 if (umem_xs->queue_id != qid || umem_xs->dev != dev) { 721 /* Share the umem with another socket on another qid 722 * and/or device. 723 */ 724 xs->pool = xp_create_and_assign_umem(xs, 725 umem_xs->umem); 726 if (!xs->pool) { 727 err = -ENOMEM; 728 sockfd_put(sock); 729 goto out_unlock; 730 } 731 732 err = xp_assign_dev_shared(xs->pool, umem_xs->umem, 733 dev, qid); 734 if (err) { 735 xp_destroy(xs->pool); 736 xs->pool = NULL; 737 sockfd_put(sock); 738 goto out_unlock; 739 } 740 } else { 741 /* Share the buffer pool with the other socket. */ 742 if (xs->fq_tmp || xs->cq_tmp) { 743 /* Do not allow setting your own fq or cq. */ 744 err = -EINVAL; 745 sockfd_put(sock); 746 goto out_unlock; 747 } 748 749 xp_get_pool(umem_xs->pool); 750 xs->pool = umem_xs->pool; 751 } 752 753 xdp_get_umem(umem_xs->umem); 754 WRITE_ONCE(xs->umem, umem_xs->umem); 755 sockfd_put(sock); 756 } else if (!xs->umem || !xsk_validate_queues(xs)) { 757 err = -EINVAL; 758 goto out_unlock; 759 } else { 760 /* This xsk has its own umem. */ 761 xs->pool = xp_create_and_assign_umem(xs, xs->umem); 762 if (!xs->pool) { 763 err = -ENOMEM; 764 goto out_unlock; 765 } 766 767 err = xp_assign_dev(xs->pool, dev, qid, flags); 768 if (err) { 769 xp_destroy(xs->pool); 770 xs->pool = NULL; 771 goto out_unlock; 772 } 773 } 774 775 xs->dev = dev; 776 xs->zc = xs->umem->zc; 777 xs->queue_id = qid; 778 xp_add_xsk(xs->pool, xs); 779 780 out_unlock: 781 if (err) { 782 dev_put(dev); 783 } else { 784 /* Matches smp_rmb() in bind() for shared umem 785 * sockets, and xsk_is_bound(). 786 */ 787 smp_wmb(); 788 WRITE_ONCE(xs->state, XSK_BOUND); 789 } 790 out_release: 791 mutex_unlock(&xs->mutex); 792 rtnl_unlock(); 793 return err; 794 } 795 796 struct xdp_umem_reg_v1 { 797 __u64 addr; /* Start of packet data area */ 798 __u64 len; /* Length of packet data area */ 799 __u32 chunk_size; 800 __u32 headroom; 801 }; 802 803 static int xsk_setsockopt(struct socket *sock, int level, int optname, 804 sockptr_t optval, unsigned int optlen) 805 { 806 struct sock *sk = sock->sk; 807 struct xdp_sock *xs = xdp_sk(sk); 808 int err; 809 810 if (level != SOL_XDP) 811 return -ENOPROTOOPT; 812 813 switch (optname) { 814 case XDP_RX_RING: 815 case XDP_TX_RING: 816 { 817 struct xsk_queue **q; 818 int entries; 819 820 if (optlen < sizeof(entries)) 821 return -EINVAL; 822 if (copy_from_sockptr(&entries, optval, sizeof(entries))) 823 return -EFAULT; 824 825 mutex_lock(&xs->mutex); 826 if (xs->state != XSK_READY) { 827 mutex_unlock(&xs->mutex); 828 return -EBUSY; 829 } 830 q = (optname == XDP_TX_RING) ? &xs->tx : &xs->rx; 831 err = xsk_init_queue(entries, q, false); 832 if (!err && optname == XDP_TX_RING) 833 /* Tx needs to be explicitly woken up the first time */ 834 xs->tx->ring->flags |= XDP_RING_NEED_WAKEUP; 835 mutex_unlock(&xs->mutex); 836 return err; 837 } 838 case XDP_UMEM_REG: 839 { 840 size_t mr_size = sizeof(struct xdp_umem_reg); 841 struct xdp_umem_reg mr = {}; 842 struct xdp_umem *umem; 843 844 if (optlen < sizeof(struct xdp_umem_reg_v1)) 845 return -EINVAL; 846 else if (optlen < sizeof(mr)) 847 mr_size = sizeof(struct xdp_umem_reg_v1); 848 849 if (copy_from_sockptr(&mr, optval, mr_size)) 850 return -EFAULT; 851 852 mutex_lock(&xs->mutex); 853 if (xs->state != XSK_READY || xs->umem) { 854 mutex_unlock(&xs->mutex); 855 return -EBUSY; 856 } 857 858 umem = xdp_umem_create(&mr); 859 if (IS_ERR(umem)) { 860 mutex_unlock(&xs->mutex); 861 return PTR_ERR(umem); 862 } 863 864 /* Make sure umem is ready before it can be seen by others */ 865 smp_wmb(); 866 WRITE_ONCE(xs->umem, umem); 867 mutex_unlock(&xs->mutex); 868 return 0; 869 } 870 case XDP_UMEM_FILL_RING: 871 case XDP_UMEM_COMPLETION_RING: 872 { 873 struct xsk_queue **q; 874 int entries; 875 876 if (copy_from_sockptr(&entries, optval, sizeof(entries))) 877 return -EFAULT; 878 879 mutex_lock(&xs->mutex); 880 if (xs->state != XSK_READY) { 881 mutex_unlock(&xs->mutex); 882 return -EBUSY; 883 } 884 885 q = (optname == XDP_UMEM_FILL_RING) ? &xs->fq_tmp : 886 &xs->cq_tmp; 887 err = xsk_init_queue(entries, q, true); 888 mutex_unlock(&xs->mutex); 889 return err; 890 } 891 default: 892 break; 893 } 894 895 return -ENOPROTOOPT; 896 } 897 898 static void xsk_enter_rxtx_offsets(struct xdp_ring_offset_v1 *ring) 899 { 900 ring->producer = offsetof(struct xdp_rxtx_ring, ptrs.producer); 901 ring->consumer = offsetof(struct xdp_rxtx_ring, ptrs.consumer); 902 ring->desc = offsetof(struct xdp_rxtx_ring, desc); 903 } 904 905 static void xsk_enter_umem_offsets(struct xdp_ring_offset_v1 *ring) 906 { 907 ring->producer = offsetof(struct xdp_umem_ring, ptrs.producer); 908 ring->consumer = offsetof(struct xdp_umem_ring, ptrs.consumer); 909 ring->desc = offsetof(struct xdp_umem_ring, desc); 910 } 911 912 struct xdp_statistics_v1 { 913 __u64 rx_dropped; 914 __u64 rx_invalid_descs; 915 __u64 tx_invalid_descs; 916 }; 917 918 static int xsk_getsockopt(struct socket *sock, int level, int optname, 919 char __user *optval, int __user *optlen) 920 { 921 struct sock *sk = sock->sk; 922 struct xdp_sock *xs = xdp_sk(sk); 923 int len; 924 925 if (level != SOL_XDP) 926 return -ENOPROTOOPT; 927 928 if (get_user(len, optlen)) 929 return -EFAULT; 930 if (len < 0) 931 return -EINVAL; 932 933 switch (optname) { 934 case XDP_STATISTICS: 935 { 936 struct xdp_statistics stats = {}; 937 bool extra_stats = true; 938 size_t stats_size; 939 940 if (len < sizeof(struct xdp_statistics_v1)) { 941 return -EINVAL; 942 } else if (len < sizeof(stats)) { 943 extra_stats = false; 944 stats_size = sizeof(struct xdp_statistics_v1); 945 } else { 946 stats_size = sizeof(stats); 947 } 948 949 mutex_lock(&xs->mutex); 950 stats.rx_dropped = xs->rx_dropped; 951 if (extra_stats) { 952 stats.rx_ring_full = xs->rx_queue_full; 953 stats.rx_fill_ring_empty_descs = 954 xs->pool ? xskq_nb_queue_empty_descs(xs->pool->fq) : 0; 955 stats.tx_ring_empty_descs = xskq_nb_queue_empty_descs(xs->tx); 956 } else { 957 stats.rx_dropped += xs->rx_queue_full; 958 } 959 stats.rx_invalid_descs = xskq_nb_invalid_descs(xs->rx); 960 stats.tx_invalid_descs = xskq_nb_invalid_descs(xs->tx); 961 mutex_unlock(&xs->mutex); 962 963 if (copy_to_user(optval, &stats, stats_size)) 964 return -EFAULT; 965 if (put_user(stats_size, optlen)) 966 return -EFAULT; 967 968 return 0; 969 } 970 case XDP_MMAP_OFFSETS: 971 { 972 struct xdp_mmap_offsets off; 973 struct xdp_mmap_offsets_v1 off_v1; 974 bool flags_supported = true; 975 void *to_copy; 976 977 if (len < sizeof(off_v1)) 978 return -EINVAL; 979 else if (len < sizeof(off)) 980 flags_supported = false; 981 982 if (flags_supported) { 983 /* xdp_ring_offset is identical to xdp_ring_offset_v1 984 * except for the flags field added to the end. 985 */ 986 xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *) 987 &off.rx); 988 xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *) 989 &off.tx); 990 xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *) 991 &off.fr); 992 xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *) 993 &off.cr); 994 off.rx.flags = offsetof(struct xdp_rxtx_ring, 995 ptrs.flags); 996 off.tx.flags = offsetof(struct xdp_rxtx_ring, 997 ptrs.flags); 998 off.fr.flags = offsetof(struct xdp_umem_ring, 999 ptrs.flags); 1000 off.cr.flags = offsetof(struct xdp_umem_ring, 1001 ptrs.flags); 1002 1003 len = sizeof(off); 1004 to_copy = &off; 1005 } else { 1006 xsk_enter_rxtx_offsets(&off_v1.rx); 1007 xsk_enter_rxtx_offsets(&off_v1.tx); 1008 xsk_enter_umem_offsets(&off_v1.fr); 1009 xsk_enter_umem_offsets(&off_v1.cr); 1010 1011 len = sizeof(off_v1); 1012 to_copy = &off_v1; 1013 } 1014 1015 if (copy_to_user(optval, to_copy, len)) 1016 return -EFAULT; 1017 if (put_user(len, optlen)) 1018 return -EFAULT; 1019 1020 return 0; 1021 } 1022 case XDP_OPTIONS: 1023 { 1024 struct xdp_options opts = {}; 1025 1026 if (len < sizeof(opts)) 1027 return -EINVAL; 1028 1029 mutex_lock(&xs->mutex); 1030 if (xs->zc) 1031 opts.flags |= XDP_OPTIONS_ZEROCOPY; 1032 mutex_unlock(&xs->mutex); 1033 1034 len = sizeof(opts); 1035 if (copy_to_user(optval, &opts, len)) 1036 return -EFAULT; 1037 if (put_user(len, optlen)) 1038 return -EFAULT; 1039 1040 return 0; 1041 } 1042 default: 1043 break; 1044 } 1045 1046 return -EOPNOTSUPP; 1047 } 1048 1049 static int xsk_mmap(struct file *file, struct socket *sock, 1050 struct vm_area_struct *vma) 1051 { 1052 loff_t offset = (loff_t)vma->vm_pgoff << PAGE_SHIFT; 1053 unsigned long size = vma->vm_end - vma->vm_start; 1054 struct xdp_sock *xs = xdp_sk(sock->sk); 1055 struct xsk_queue *q = NULL; 1056 unsigned long pfn; 1057 struct page *qpg; 1058 1059 if (READ_ONCE(xs->state) != XSK_READY) 1060 return -EBUSY; 1061 1062 if (offset == XDP_PGOFF_RX_RING) { 1063 q = READ_ONCE(xs->rx); 1064 } else if (offset == XDP_PGOFF_TX_RING) { 1065 q = READ_ONCE(xs->tx); 1066 } else { 1067 /* Matches the smp_wmb() in XDP_UMEM_REG */ 1068 smp_rmb(); 1069 if (offset == XDP_UMEM_PGOFF_FILL_RING) 1070 q = READ_ONCE(xs->fq_tmp); 1071 else if (offset == XDP_UMEM_PGOFF_COMPLETION_RING) 1072 q = READ_ONCE(xs->cq_tmp); 1073 } 1074 1075 if (!q) 1076 return -EINVAL; 1077 1078 /* Matches the smp_wmb() in xsk_init_queue */ 1079 smp_rmb(); 1080 qpg = virt_to_head_page(q->ring); 1081 if (size > page_size(qpg)) 1082 return -EINVAL; 1083 1084 pfn = virt_to_phys(q->ring) >> PAGE_SHIFT; 1085 return remap_pfn_range(vma, vma->vm_start, pfn, 1086 size, vma->vm_page_prot); 1087 } 1088 1089 static int xsk_notifier(struct notifier_block *this, 1090 unsigned long msg, void *ptr) 1091 { 1092 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1093 struct net *net = dev_net(dev); 1094 struct sock *sk; 1095 1096 switch (msg) { 1097 case NETDEV_UNREGISTER: 1098 mutex_lock(&net->xdp.lock); 1099 sk_for_each(sk, &net->xdp.list) { 1100 struct xdp_sock *xs = xdp_sk(sk); 1101 1102 mutex_lock(&xs->mutex); 1103 if (xs->dev == dev) { 1104 sk->sk_err = ENETDOWN; 1105 if (!sock_flag(sk, SOCK_DEAD)) 1106 sk->sk_error_report(sk); 1107 1108 xsk_unbind_dev(xs); 1109 1110 /* Clear device references. */ 1111 xp_clear_dev(xs->pool); 1112 } 1113 mutex_unlock(&xs->mutex); 1114 } 1115 mutex_unlock(&net->xdp.lock); 1116 break; 1117 } 1118 return NOTIFY_DONE; 1119 } 1120 1121 static struct proto xsk_proto = { 1122 .name = "XDP", 1123 .owner = THIS_MODULE, 1124 .obj_size = sizeof(struct xdp_sock), 1125 }; 1126 1127 static const struct proto_ops xsk_proto_ops = { 1128 .family = PF_XDP, 1129 .owner = THIS_MODULE, 1130 .release = xsk_release, 1131 .bind = xsk_bind, 1132 .connect = sock_no_connect, 1133 .socketpair = sock_no_socketpair, 1134 .accept = sock_no_accept, 1135 .getname = sock_no_getname, 1136 .poll = xsk_poll, 1137 .ioctl = sock_no_ioctl, 1138 .listen = sock_no_listen, 1139 .shutdown = sock_no_shutdown, 1140 .setsockopt = xsk_setsockopt, 1141 .getsockopt = xsk_getsockopt, 1142 .sendmsg = xsk_sendmsg, 1143 .recvmsg = sock_no_recvmsg, 1144 .mmap = xsk_mmap, 1145 .sendpage = sock_no_sendpage, 1146 }; 1147 1148 static void xsk_destruct(struct sock *sk) 1149 { 1150 struct xdp_sock *xs = xdp_sk(sk); 1151 1152 if (!sock_flag(sk, SOCK_DEAD)) 1153 return; 1154 1155 if (!xp_put_pool(xs->pool)) 1156 xdp_put_umem(xs->umem, !xs->pool); 1157 1158 sk_refcnt_debug_dec(sk); 1159 } 1160 1161 static int xsk_create(struct net *net, struct socket *sock, int protocol, 1162 int kern) 1163 { 1164 struct xdp_sock *xs; 1165 struct sock *sk; 1166 1167 if (!ns_capable(net->user_ns, CAP_NET_RAW)) 1168 return -EPERM; 1169 if (sock->type != SOCK_RAW) 1170 return -ESOCKTNOSUPPORT; 1171 1172 if (protocol) 1173 return -EPROTONOSUPPORT; 1174 1175 sock->state = SS_UNCONNECTED; 1176 1177 sk = sk_alloc(net, PF_XDP, GFP_KERNEL, &xsk_proto, kern); 1178 if (!sk) 1179 return -ENOBUFS; 1180 1181 sock->ops = &xsk_proto_ops; 1182 1183 sock_init_data(sock, sk); 1184 1185 sk->sk_family = PF_XDP; 1186 1187 sk->sk_destruct = xsk_destruct; 1188 sk_refcnt_debug_inc(sk); 1189 1190 sock_set_flag(sk, SOCK_RCU_FREE); 1191 1192 xs = xdp_sk(sk); 1193 xs->state = XSK_READY; 1194 mutex_init(&xs->mutex); 1195 spin_lock_init(&xs->rx_lock); 1196 spin_lock_init(&xs->tx_completion_lock); 1197 1198 INIT_LIST_HEAD(&xs->map_list); 1199 spin_lock_init(&xs->map_list_lock); 1200 1201 mutex_lock(&net->xdp.lock); 1202 sk_add_node_rcu(sk, &net->xdp.list); 1203 mutex_unlock(&net->xdp.lock); 1204 1205 local_bh_disable(); 1206 sock_prot_inuse_add(net, &xsk_proto, 1); 1207 local_bh_enable(); 1208 1209 return 0; 1210 } 1211 1212 static const struct net_proto_family xsk_family_ops = { 1213 .family = PF_XDP, 1214 .create = xsk_create, 1215 .owner = THIS_MODULE, 1216 }; 1217 1218 static struct notifier_block xsk_netdev_notifier = { 1219 .notifier_call = xsk_notifier, 1220 }; 1221 1222 static int __net_init xsk_net_init(struct net *net) 1223 { 1224 mutex_init(&net->xdp.lock); 1225 INIT_HLIST_HEAD(&net->xdp.list); 1226 return 0; 1227 } 1228 1229 static void __net_exit xsk_net_exit(struct net *net) 1230 { 1231 WARN_ON_ONCE(!hlist_empty(&net->xdp.list)); 1232 } 1233 1234 static struct pernet_operations xsk_net_ops = { 1235 .init = xsk_net_init, 1236 .exit = xsk_net_exit, 1237 }; 1238 1239 static int __init xsk_init(void) 1240 { 1241 int err, cpu; 1242 1243 err = proto_register(&xsk_proto, 0 /* no slab */); 1244 if (err) 1245 goto out; 1246 1247 err = sock_register(&xsk_family_ops); 1248 if (err) 1249 goto out_proto; 1250 1251 err = register_pernet_subsys(&xsk_net_ops); 1252 if (err) 1253 goto out_sk; 1254 1255 err = register_netdevice_notifier(&xsk_netdev_notifier); 1256 if (err) 1257 goto out_pernet; 1258 1259 for_each_possible_cpu(cpu) 1260 INIT_LIST_HEAD(&per_cpu(xskmap_flush_list, cpu)); 1261 return 0; 1262 1263 out_pernet: 1264 unregister_pernet_subsys(&xsk_net_ops); 1265 out_sk: 1266 sock_unregister(PF_XDP); 1267 out_proto: 1268 proto_unregister(&xsk_proto); 1269 out: 1270 return err; 1271 } 1272 1273 fs_initcall(xsk_init); 1274