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 34static DEFINE_PER_CPU(struct list_head, xskmap_flush_list); 35 36void 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} 44EXPORT_SYMBOL(xsk_set_rx_need_wakeup); 45 46void 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} 61EXPORT_SYMBOL(xsk_set_tx_need_wakeup); 62 63void 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} 71EXPORT_SYMBOL(xsk_clear_rx_need_wakeup); 72 73void 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} 88EXPORT_SYMBOL(xsk_clear_tx_need_wakeup); 89 90bool xsk_uses_need_wakeup(struct xsk_buff_pool *pool) 91{ 92 return pool->uses_need_wakeup; 93} 94EXPORT_SYMBOL(xsk_uses_need_wakeup); 95 96struct 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} 106EXPORT_SYMBOL(xsk_get_pool_from_qid); 107 108void xsk_clear_pool_at_qid(struct net_device *dev, u16 queue_id) 109{ 110 if (queue_id < dev->num_rx_queues) 111 dev->_rx[queue_id].pool = NULL; 112 if (queue_id < dev->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 */ 120int 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 136void xp_release(struct xdp_buff_xsk *xskb) 137{ 138 xskb->pool->free_heads[xskb->pool->free_heads_cnt++] = xskb; 139} 140 141static 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 151static 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 168static 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 186static 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 214static 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 222static 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 232static 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 250static 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 257int 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 268int __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 283void __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 294void xsk_tx_completed(struct xsk_buff_pool *pool, u32 nb_entries) 295{ 296 xskq_prod_submit_n(pool->cq, nb_entries); 297} 298EXPORT_SYMBOL(xsk_tx_completed); 299 300void 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} 312EXPORT_SYMBOL(xsk_tx_release); 313 314bool 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 338out: 339 rcu_read_unlock(); 340 return false; 341} 342EXPORT_SYMBOL(xsk_tx_peek_desc); 343 344static 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 356static int xsk_zc_xmit(struct xdp_sock *xs) 357{ 358 return xsk_wakeup(xs, XDP_WAKEUP_TX); 359} 360 361static 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->pool->cq_lock, flags); 368 xskq_prod_submit_addr(xs->pool->cq, addr); 369 spin_unlock_irqrestore(&xs->pool->cq_lock, flags); 370 371 sock_wfree(skb); 372} 373 374static 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 unsigned long flags; 382 int err = 0; 383 u32 hr, tr; 384 385 mutex_lock(&xs->mutex); 386 387 if (xs->queue_id >= xs->dev->real_num_tx_queues) 388 goto out; 389 390 hr = max(NET_SKB_PAD, L1_CACHE_ALIGN(xs->dev->needed_headroom)); 391 tr = xs->dev->needed_tailroom; 392 393 while (xskq_cons_peek_desc(xs->tx, &desc, xs->pool)) { 394 char *buffer; 395 u64 addr; 396 u32 len; 397 398 if (max_batch-- == 0) { 399 err = -EAGAIN; 400 goto out; 401 } 402 403 len = desc.len; 404 skb = sock_alloc_send_skb(sk, hr + len + tr, 1, &err); 405 if (unlikely(!skb)) 406 goto out; 407 408 skb_reserve(skb, hr); 409 skb_put(skb, len); 410 411 addr = desc.addr; 412 buffer = xsk_buff_raw_get_data(xs->pool, addr); 413 err = skb_store_bits(skb, 0, buffer, len); 414 /* This is the backpressure mechanism for the Tx path. 415 * Reserve space in the completion queue and only proceed 416 * if there is space in it. This avoids having to implement 417 * any buffering in the Tx path. 418 */ 419 spin_lock_irqsave(&xs->pool->cq_lock, flags); 420 if (unlikely(err) || xskq_prod_reserve(xs->pool->cq)) { 421 spin_unlock_irqrestore(&xs->pool->cq_lock, flags); 422 kfree_skb(skb); 423 goto out; 424 } 425 spin_unlock_irqrestore(&xs->pool->cq_lock, flags); 426 427 skb->dev = xs->dev; 428 skb->priority = sk->sk_priority; 429 skb->mark = sk->sk_mark; 430 skb_shinfo(skb)->destructor_arg = (void *)(long)desc.addr; 431 skb->destructor = xsk_destruct_skb; 432 433 err = __dev_direct_xmit(skb, xs->queue_id); 434 if (err == NETDEV_TX_BUSY) { 435 /* Tell user-space to retry the send */ 436 skb->destructor = sock_wfree; 437 spin_lock_irqsave(&xs->pool->cq_lock, flags); 438 xskq_prod_cancel(xs->pool->cq); 439 spin_unlock_irqrestore(&xs->pool->cq_lock, flags); 440 /* Free skb without triggering the perf drop trace */ 441 consume_skb(skb); 442 err = -EAGAIN; 443 goto out; 444 } 445 446 xskq_cons_release(xs->tx); 447 /* Ignore NET_XMIT_CN as packet might have been sent */ 448 if (err == NET_XMIT_DROP) { 449 /* SKB completed but not sent */ 450 err = -EBUSY; 451 goto out; 452 } 453 454 sent_frame = true; 455 } 456 457 xs->tx->queue_empty_descs++; 458 459out: 460 if (sent_frame) 461 if (xsk_tx_writeable(xs)) 462 sk->sk_write_space(sk); 463 464 mutex_unlock(&xs->mutex); 465 return err; 466} 467 468static int __xsk_sendmsg(struct sock *sk) 469{ 470 struct xdp_sock *xs = xdp_sk(sk); 471 472 if (unlikely(!(xs->dev->flags & IFF_UP))) 473 return -ENETDOWN; 474 if (unlikely(!xs->tx)) 475 return -ENOBUFS; 476 477 return xs->zc ? xsk_zc_xmit(xs) : xsk_generic_xmit(sk); 478} 479 480static int xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len) 481{ 482 bool need_wait = !(m->msg_flags & MSG_DONTWAIT); 483 struct sock *sk = sock->sk; 484 struct xdp_sock *xs = xdp_sk(sk); 485 486 if (unlikely(!xsk_is_bound(xs))) 487 return -ENXIO; 488 if (unlikely(need_wait)) 489 return -EOPNOTSUPP; 490 491 return __xsk_sendmsg(sk); 492} 493 494static __poll_t xsk_poll(struct file *file, struct socket *sock, 495 struct poll_table_struct *wait) 496{ 497 __poll_t mask = 0; 498 struct sock *sk = sock->sk; 499 struct xdp_sock *xs = xdp_sk(sk); 500 struct xsk_buff_pool *pool; 501 502 sock_poll_wait(file, sock, wait); 503 504 if (unlikely(!xsk_is_bound(xs))) 505 return mask; 506 507 pool = xs->pool; 508 509 if (pool->cached_need_wakeup) { 510 if (xs->zc) 511 xsk_wakeup(xs, pool->cached_need_wakeup); 512 else 513 /* Poll needs to drive Tx also in copy mode */ 514 __xsk_sendmsg(sk); 515 } 516 517 if (xs->rx && !xskq_prod_is_empty(xs->rx)) 518 mask |= EPOLLIN | EPOLLRDNORM; 519 if (xs->tx && xsk_tx_writeable(xs)) 520 mask |= EPOLLOUT | EPOLLWRNORM; 521 522 return mask; 523} 524 525static int xsk_init_queue(u32 entries, struct xsk_queue **queue, 526 bool umem_queue) 527{ 528 struct xsk_queue *q; 529 530 if (entries == 0 || *queue || !is_power_of_2(entries)) 531 return -EINVAL; 532 533 q = xskq_create(entries, umem_queue); 534 if (!q) 535 return -ENOMEM; 536 537 /* Make sure queue is ready before it can be seen by others */ 538 smp_wmb(); 539 WRITE_ONCE(*queue, q); 540 return 0; 541} 542 543static void xsk_unbind_dev(struct xdp_sock *xs) 544{ 545 struct net_device *dev = xs->dev; 546 547 if (xs->state != XSK_BOUND) 548 return; 549 WRITE_ONCE(xs->state, XSK_UNBOUND); 550 551 /* Wait for driver to stop using the xdp socket. */ 552 xp_del_xsk(xs->pool, xs); 553 xs->dev = NULL; 554 synchronize_net(); 555 dev_put(dev); 556} 557 558static struct xsk_map *xsk_get_map_list_entry(struct xdp_sock *xs, 559 struct xdp_sock ***map_entry) 560{ 561 struct xsk_map *map = NULL; 562 struct xsk_map_node *node; 563 564 *map_entry = NULL; 565 566 spin_lock_bh(&xs->map_list_lock); 567 node = list_first_entry_or_null(&xs->map_list, struct xsk_map_node, 568 node); 569 if (node) { 570 WARN_ON(xsk_map_inc(node->map)); 571 map = node->map; 572 *map_entry = node->map_entry; 573 } 574 spin_unlock_bh(&xs->map_list_lock); 575 return map; 576} 577 578static void xsk_delete_from_maps(struct xdp_sock *xs) 579{ 580 /* This function removes the current XDP socket from all the 581 * maps it resides in. We need to take extra care here, due to 582 * the two locks involved. Each map has a lock synchronizing 583 * updates to the entries, and each socket has a lock that 584 * synchronizes access to the list of maps (map_list). For 585 * deadlock avoidance the locks need to be taken in the order 586 * "map lock"->"socket map list lock". We start off by 587 * accessing the socket map list, and take a reference to the 588 * map to guarantee existence between the 589 * xsk_get_map_list_entry() and xsk_map_try_sock_delete() 590 * calls. Then we ask the map to remove the socket, which 591 * tries to remove the socket from the map. Note that there 592 * might be updates to the map between 593 * xsk_get_map_list_entry() and xsk_map_try_sock_delete(). 594 */ 595 struct xdp_sock **map_entry = NULL; 596 struct xsk_map *map; 597 598 while ((map = xsk_get_map_list_entry(xs, &map_entry))) { 599 xsk_map_try_sock_delete(map, xs, map_entry); 600 xsk_map_put(map); 601 } 602} 603 604static int xsk_release(struct socket *sock) 605{ 606 struct sock *sk = sock->sk; 607 struct xdp_sock *xs = xdp_sk(sk); 608 struct net *net; 609 610 if (!sk) 611 return 0; 612 613 net = sock_net(sk); 614 615 mutex_lock(&net->xdp.lock); 616 sk_del_node_init_rcu(sk); 617 mutex_unlock(&net->xdp.lock); 618 619 local_bh_disable(); 620 sock_prot_inuse_add(net, sk->sk_prot, -1); 621 local_bh_enable(); 622 623 xsk_delete_from_maps(xs); 624 mutex_lock(&xs->mutex); 625 xsk_unbind_dev(xs); 626 mutex_unlock(&xs->mutex); 627 628 xskq_destroy(xs->rx); 629 xskq_destroy(xs->tx); 630 xskq_destroy(xs->fq_tmp); 631 xskq_destroy(xs->cq_tmp); 632 633 sock_orphan(sk); 634 sock->sk = NULL; 635 636 sk_refcnt_debug_release(sk); 637 sock_put(sk); 638 639 return 0; 640} 641 642static struct socket *xsk_lookup_xsk_from_fd(int fd) 643{ 644 struct socket *sock; 645 int err; 646 647 sock = sockfd_lookup(fd, &err); 648 if (!sock) 649 return ERR_PTR(-ENOTSOCK); 650 651 if (sock->sk->sk_family != PF_XDP) { 652 sockfd_put(sock); 653 return ERR_PTR(-ENOPROTOOPT); 654 } 655 656 return sock; 657} 658 659static bool xsk_validate_queues(struct xdp_sock *xs) 660{ 661 return xs->fq_tmp && xs->cq_tmp; 662} 663 664static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len) 665{ 666 struct sockaddr_xdp *sxdp = (struct sockaddr_xdp *)addr; 667 struct sock *sk = sock->sk; 668 struct xdp_sock *xs = xdp_sk(sk); 669 struct net_device *dev; 670 int bound_dev_if; 671 u32 flags, qid; 672 int err = 0; 673 674 if (addr_len < sizeof(struct sockaddr_xdp)) 675 return -EINVAL; 676 if (sxdp->sxdp_family != AF_XDP) 677 return -EINVAL; 678 679 flags = sxdp->sxdp_flags; 680 if (flags & ~(XDP_SHARED_UMEM | XDP_COPY | XDP_ZEROCOPY | 681 XDP_USE_NEED_WAKEUP)) 682 return -EINVAL; 683 684 bound_dev_if = READ_ONCE(sk->sk_bound_dev_if); 685 if (bound_dev_if && bound_dev_if != sxdp->sxdp_ifindex) 686 return -EINVAL; 687 688 rtnl_lock(); 689 mutex_lock(&xs->mutex); 690 if (xs->state != XSK_READY) { 691 err = -EBUSY; 692 goto out_release; 693 } 694 695 dev = dev_get_by_index(sock_net(sk), sxdp->sxdp_ifindex); 696 if (!dev) { 697 err = -ENODEV; 698 goto out_release; 699 } 700 701 if (!xs->rx && !xs->tx) { 702 err = -EINVAL; 703 goto out_unlock; 704 } 705 706 qid = sxdp->sxdp_queue_id; 707 708 if (flags & XDP_SHARED_UMEM) { 709 struct xdp_sock *umem_xs; 710 struct socket *sock; 711 712 if ((flags & XDP_COPY) || (flags & XDP_ZEROCOPY) || 713 (flags & XDP_USE_NEED_WAKEUP)) { 714 /* Cannot specify flags for shared sockets. */ 715 err = -EINVAL; 716 goto out_unlock; 717 } 718 719 if (xs->umem) { 720 /* We have already our own. */ 721 err = -EINVAL; 722 goto out_unlock; 723 } 724 725 sock = xsk_lookup_xsk_from_fd(sxdp->sxdp_shared_umem_fd); 726 if (IS_ERR(sock)) { 727 err = PTR_ERR(sock); 728 goto out_unlock; 729 } 730 731 umem_xs = xdp_sk(sock->sk); 732 if (!xsk_is_bound(umem_xs)) { 733 err = -EBADF; 734 sockfd_put(sock); 735 goto out_unlock; 736 } 737 738 if (umem_xs->queue_id != qid || umem_xs->dev != dev) { 739 /* Share the umem with another socket on another qid 740 * and/or device. 741 */ 742 xs->pool = xp_create_and_assign_umem(xs, 743 umem_xs->umem); 744 if (!xs->pool) { 745 err = -ENOMEM; 746 sockfd_put(sock); 747 goto out_unlock; 748 } 749 750 err = xp_assign_dev_shared(xs->pool, umem_xs, dev, 751 qid); 752 if (err) { 753 xp_destroy(xs->pool); 754 xs->pool = NULL; 755 sockfd_put(sock); 756 goto out_unlock; 757 } 758 } else { 759 /* Share the buffer pool with the other socket. */ 760 if (xs->fq_tmp || xs->cq_tmp) { 761 /* Do not allow setting your own fq or cq. */ 762 err = -EINVAL; 763 sockfd_put(sock); 764 goto out_unlock; 765 } 766 767 xp_get_pool(umem_xs->pool); 768 xs->pool = umem_xs->pool; 769 } 770 771 xdp_get_umem(umem_xs->umem); 772 WRITE_ONCE(xs->umem, umem_xs->umem); 773 sockfd_put(sock); 774 } else if (!xs->umem || !xsk_validate_queues(xs)) { 775 err = -EINVAL; 776 goto out_unlock; 777 } else { 778 /* This xsk has its own umem. */ 779 xs->pool = xp_create_and_assign_umem(xs, xs->umem); 780 if (!xs->pool) { 781 err = -ENOMEM; 782 goto out_unlock; 783 } 784 785 err = xp_assign_dev(xs->pool, dev, qid, flags); 786 if (err) { 787 xp_destroy(xs->pool); 788 xs->pool = NULL; 789 goto out_unlock; 790 } 791 } 792 793 /* FQ and CQ are now owned by the buffer pool and cleaned up with it. */ 794 xs->fq_tmp = NULL; 795 xs->cq_tmp = NULL; 796 797 xs->dev = dev; 798 xs->zc = xs->umem->zc; 799 xs->queue_id = qid; 800 xp_add_xsk(xs->pool, xs); 801 802out_unlock: 803 if (err) { 804 dev_put(dev); 805 } else { 806 /* Matches smp_rmb() in bind() for shared umem 807 * sockets, and xsk_is_bound(). 808 */ 809 smp_wmb(); 810 WRITE_ONCE(xs->state, XSK_BOUND); 811 } 812out_release: 813 mutex_unlock(&xs->mutex); 814 rtnl_unlock(); 815 return err; 816} 817 818struct xdp_umem_reg_v1 { 819 __u64 addr; /* Start of packet data area */ 820 __u64 len; /* Length of packet data area */ 821 __u32 chunk_size; 822 __u32 headroom; 823}; 824 825static int xsk_setsockopt(struct socket *sock, int level, int optname, 826 sockptr_t optval, unsigned int optlen) 827{ 828 struct sock *sk = sock->sk; 829 struct xdp_sock *xs = xdp_sk(sk); 830 int err; 831 832 if (level != SOL_XDP) 833 return -ENOPROTOOPT; 834 835 switch (optname) { 836 case XDP_RX_RING: 837 case XDP_TX_RING: 838 { 839 struct xsk_queue **q; 840 int entries; 841 842 if (optlen < sizeof(entries)) 843 return -EINVAL; 844 if (copy_from_sockptr(&entries, optval, sizeof(entries))) 845 return -EFAULT; 846 847 mutex_lock(&xs->mutex); 848 if (xs->state != XSK_READY) { 849 mutex_unlock(&xs->mutex); 850 return -EBUSY; 851 } 852 q = (optname == XDP_TX_RING) ? &xs->tx : &xs->rx; 853 err = xsk_init_queue(entries, q, false); 854 if (!err && optname == XDP_TX_RING) 855 /* Tx needs to be explicitly woken up the first time */ 856 xs->tx->ring->flags |= XDP_RING_NEED_WAKEUP; 857 mutex_unlock(&xs->mutex); 858 return err; 859 } 860 case XDP_UMEM_REG: 861 { 862 size_t mr_size = sizeof(struct xdp_umem_reg); 863 struct xdp_umem_reg mr = {}; 864 struct xdp_umem *umem; 865 866 if (optlen < sizeof(struct xdp_umem_reg_v1)) 867 return -EINVAL; 868 else if (optlen < sizeof(mr)) 869 mr_size = sizeof(struct xdp_umem_reg_v1); 870 871 if (copy_from_sockptr(&mr, optval, mr_size)) 872 return -EFAULT; 873 874 mutex_lock(&xs->mutex); 875 if (xs->state != XSK_READY || xs->umem) { 876 mutex_unlock(&xs->mutex); 877 return -EBUSY; 878 } 879 880 umem = xdp_umem_create(&mr); 881 if (IS_ERR(umem)) { 882 mutex_unlock(&xs->mutex); 883 return PTR_ERR(umem); 884 } 885 886 /* Make sure umem is ready before it can be seen by others */ 887 smp_wmb(); 888 WRITE_ONCE(xs->umem, umem); 889 mutex_unlock(&xs->mutex); 890 return 0; 891 } 892 case XDP_UMEM_FILL_RING: 893 case XDP_UMEM_COMPLETION_RING: 894 { 895 struct xsk_queue **q; 896 int entries; 897 898 if (copy_from_sockptr(&entries, optval, sizeof(entries))) 899 return -EFAULT; 900 901 mutex_lock(&xs->mutex); 902 if (xs->state != XSK_READY) { 903 mutex_unlock(&xs->mutex); 904 return -EBUSY; 905 } 906 907 q = (optname == XDP_UMEM_FILL_RING) ? &xs->fq_tmp : 908 &xs->cq_tmp; 909 err = xsk_init_queue(entries, q, true); 910 mutex_unlock(&xs->mutex); 911 return err; 912 } 913 default: 914 break; 915 } 916 917 return -ENOPROTOOPT; 918} 919 920static void xsk_enter_rxtx_offsets(struct xdp_ring_offset_v1 *ring) 921{ 922 ring->producer = offsetof(struct xdp_rxtx_ring, ptrs.producer); 923 ring->consumer = offsetof(struct xdp_rxtx_ring, ptrs.consumer); 924 ring->desc = offsetof(struct xdp_rxtx_ring, desc); 925} 926 927static void xsk_enter_umem_offsets(struct xdp_ring_offset_v1 *ring) 928{ 929 ring->producer = offsetof(struct xdp_umem_ring, ptrs.producer); 930 ring->consumer = offsetof(struct xdp_umem_ring, ptrs.consumer); 931 ring->desc = offsetof(struct xdp_umem_ring, desc); 932} 933 934struct xdp_statistics_v1 { 935 __u64 rx_dropped; 936 __u64 rx_invalid_descs; 937 __u64 tx_invalid_descs; 938}; 939 940static int xsk_getsockopt(struct socket *sock, int level, int optname, 941 char __user *optval, int __user *optlen) 942{ 943 struct sock *sk = sock->sk; 944 struct xdp_sock *xs = xdp_sk(sk); 945 int len; 946 947 if (level != SOL_XDP) 948 return -ENOPROTOOPT; 949 950 if (get_user(len, optlen)) 951 return -EFAULT; 952 if (len < 0) 953 return -EINVAL; 954 955 switch (optname) { 956 case XDP_STATISTICS: 957 { 958 struct xdp_statistics stats = {}; 959 bool extra_stats = true; 960 size_t stats_size; 961 962 if (len < sizeof(struct xdp_statistics_v1)) { 963 return -EINVAL; 964 } else if (len < sizeof(stats)) { 965 extra_stats = false; 966 stats_size = sizeof(struct xdp_statistics_v1); 967 } else { 968 stats_size = sizeof(stats); 969 } 970 971 mutex_lock(&xs->mutex); 972 stats.rx_dropped = xs->rx_dropped; 973 if (extra_stats) { 974 stats.rx_ring_full = xs->rx_queue_full; 975 stats.rx_fill_ring_empty_descs = 976 xs->pool ? xskq_nb_queue_empty_descs(xs->pool->fq) : 0; 977 stats.tx_ring_empty_descs = xskq_nb_queue_empty_descs(xs->tx); 978 } else { 979 stats.rx_dropped += xs->rx_queue_full; 980 } 981 stats.rx_invalid_descs = xskq_nb_invalid_descs(xs->rx); 982 stats.tx_invalid_descs = xskq_nb_invalid_descs(xs->tx); 983 mutex_unlock(&xs->mutex); 984 985 if (copy_to_user(optval, &stats, stats_size)) 986 return -EFAULT; 987 if (put_user(stats_size, optlen)) 988 return -EFAULT; 989 990 return 0; 991 } 992 case XDP_MMAP_OFFSETS: 993 { 994 struct xdp_mmap_offsets off; 995 struct xdp_mmap_offsets_v1 off_v1; 996 bool flags_supported = true; 997 void *to_copy; 998 999 if (len < sizeof(off_v1)) 1000 return -EINVAL; 1001 else if (len < sizeof(off)) 1002 flags_supported = false; 1003 1004 if (flags_supported) { 1005 /* xdp_ring_offset is identical to xdp_ring_offset_v1 1006 * except for the flags field added to the end. 1007 */ 1008 xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *) 1009 &off.rx); 1010 xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *) 1011 &off.tx); 1012 xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *) 1013 &off.fr); 1014 xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *) 1015 &off.cr); 1016 off.rx.flags = offsetof(struct xdp_rxtx_ring, 1017 ptrs.flags); 1018 off.tx.flags = offsetof(struct xdp_rxtx_ring, 1019 ptrs.flags); 1020 off.fr.flags = offsetof(struct xdp_umem_ring, 1021 ptrs.flags); 1022 off.cr.flags = offsetof(struct xdp_umem_ring, 1023 ptrs.flags); 1024 1025 len = sizeof(off); 1026 to_copy = &off; 1027 } else { 1028 xsk_enter_rxtx_offsets(&off_v1.rx); 1029 xsk_enter_rxtx_offsets(&off_v1.tx); 1030 xsk_enter_umem_offsets(&off_v1.fr); 1031 xsk_enter_umem_offsets(&off_v1.cr); 1032 1033 len = sizeof(off_v1); 1034 to_copy = &off_v1; 1035 } 1036 1037 if (copy_to_user(optval, to_copy, len)) 1038 return -EFAULT; 1039 if (put_user(len, optlen)) 1040 return -EFAULT; 1041 1042 return 0; 1043 } 1044 case XDP_OPTIONS: 1045 { 1046 struct xdp_options opts = {}; 1047 1048 if (len < sizeof(opts)) 1049 return -EINVAL; 1050 1051 mutex_lock(&xs->mutex); 1052 if (xs->zc) 1053 opts.flags |= XDP_OPTIONS_ZEROCOPY; 1054 mutex_unlock(&xs->mutex); 1055 1056 len = sizeof(opts); 1057 if (copy_to_user(optval, &opts, len)) 1058 return -EFAULT; 1059 if (put_user(len, optlen)) 1060 return -EFAULT; 1061 1062 return 0; 1063 } 1064 default: 1065 break; 1066 } 1067 1068 return -EOPNOTSUPP; 1069} 1070 1071static int xsk_mmap(struct file *file, struct socket *sock, 1072 struct vm_area_struct *vma) 1073{ 1074 loff_t offset = (loff_t)vma->vm_pgoff << PAGE_SHIFT; 1075 unsigned long size = vma->vm_end - vma->vm_start; 1076 struct xdp_sock *xs = xdp_sk(sock->sk); 1077 struct xsk_queue *q = NULL; 1078 unsigned long pfn; 1079 struct page *qpg; 1080 1081 if (READ_ONCE(xs->state) != XSK_READY) 1082 return -EBUSY; 1083 1084 if (offset == XDP_PGOFF_RX_RING) { 1085 q = READ_ONCE(xs->rx); 1086 } else if (offset == XDP_PGOFF_TX_RING) { 1087 q = READ_ONCE(xs->tx); 1088 } else { 1089 /* Matches the smp_wmb() in XDP_UMEM_REG */ 1090 smp_rmb(); 1091 if (offset == XDP_UMEM_PGOFF_FILL_RING) 1092 q = READ_ONCE(xs->fq_tmp); 1093 else if (offset == XDP_UMEM_PGOFF_COMPLETION_RING) 1094 q = READ_ONCE(xs->cq_tmp); 1095 } 1096 1097 if (!q) 1098 return -EINVAL; 1099 1100 /* Matches the smp_wmb() in xsk_init_queue */ 1101 smp_rmb(); 1102 qpg = virt_to_head_page(q->ring); 1103 if (size > page_size(qpg)) 1104 return -EINVAL; 1105 1106 pfn = virt_to_phys(q->ring) >> PAGE_SHIFT; 1107 return remap_pfn_range(vma, vma->vm_start, pfn, 1108 size, vma->vm_page_prot); 1109} 1110 1111static int xsk_notifier(struct notifier_block *this, 1112 unsigned long msg, void *ptr) 1113{ 1114 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1115 struct net *net = dev_net(dev); 1116 struct sock *sk; 1117 1118 switch (msg) { 1119 case NETDEV_UNREGISTER: 1120 mutex_lock(&net->xdp.lock); 1121 sk_for_each(sk, &net->xdp.list) { 1122 struct xdp_sock *xs = xdp_sk(sk); 1123 1124 mutex_lock(&xs->mutex); 1125 if (xs->dev == dev) { 1126 sk->sk_err = ENETDOWN; 1127 if (!sock_flag(sk, SOCK_DEAD)) 1128 sk->sk_error_report(sk); 1129 1130 xsk_unbind_dev(xs); 1131 1132 /* Clear device references. */ 1133 xp_clear_dev(xs->pool); 1134 } 1135 mutex_unlock(&xs->mutex); 1136 } 1137 mutex_unlock(&net->xdp.lock); 1138 break; 1139 } 1140 return NOTIFY_DONE; 1141} 1142 1143static struct proto xsk_proto = { 1144 .name = "XDP", 1145 .owner = THIS_MODULE, 1146 .obj_size = sizeof(struct xdp_sock), 1147}; 1148 1149static const struct proto_ops xsk_proto_ops = { 1150 .family = PF_XDP, 1151 .owner = THIS_MODULE, 1152 .release = xsk_release, 1153 .bind = xsk_bind, 1154 .connect = sock_no_connect, 1155 .socketpair = sock_no_socketpair, 1156 .accept = sock_no_accept, 1157 .getname = sock_no_getname, 1158 .poll = xsk_poll, 1159 .ioctl = sock_no_ioctl, 1160 .listen = sock_no_listen, 1161 .shutdown = sock_no_shutdown, 1162 .setsockopt = xsk_setsockopt, 1163 .getsockopt = xsk_getsockopt, 1164 .sendmsg = xsk_sendmsg, 1165 .recvmsg = sock_no_recvmsg, 1166 .mmap = xsk_mmap, 1167 .sendpage = sock_no_sendpage, 1168}; 1169 1170static void xsk_destruct(struct sock *sk) 1171{ 1172 struct xdp_sock *xs = xdp_sk(sk); 1173 1174 if (!sock_flag(sk, SOCK_DEAD)) 1175 return; 1176 1177 if (!xp_put_pool(xs->pool)) 1178 xdp_put_umem(xs->umem, !xs->pool); 1179 1180 sk_refcnt_debug_dec(sk); 1181} 1182 1183static int xsk_create(struct net *net, struct socket *sock, int protocol, 1184 int kern) 1185{ 1186 struct xdp_sock *xs; 1187 struct sock *sk; 1188 1189 if (!ns_capable(net->user_ns, CAP_NET_RAW)) 1190 return -EPERM; 1191 if (sock->type != SOCK_RAW) 1192 return -ESOCKTNOSUPPORT; 1193 1194 if (protocol) 1195 return -EPROTONOSUPPORT; 1196 1197 sock->state = SS_UNCONNECTED; 1198 1199 sk = sk_alloc(net, PF_XDP, GFP_KERNEL, &xsk_proto, kern); 1200 if (!sk) 1201 return -ENOBUFS; 1202 1203 sock->ops = &xsk_proto_ops; 1204 1205 sock_init_data(sock, sk); 1206 1207 sk->sk_family = PF_XDP; 1208 1209 sk->sk_destruct = xsk_destruct; 1210 sk_refcnt_debug_inc(sk); 1211 1212 sock_set_flag(sk, SOCK_RCU_FREE); 1213 1214 xs = xdp_sk(sk); 1215 xs->state = XSK_READY; 1216 mutex_init(&xs->mutex); 1217 spin_lock_init(&xs->rx_lock); 1218 1219 INIT_LIST_HEAD(&xs->map_list); 1220 spin_lock_init(&xs->map_list_lock); 1221 1222 mutex_lock(&net->xdp.lock); 1223 sk_add_node_rcu(sk, &net->xdp.list); 1224 mutex_unlock(&net->xdp.lock); 1225 1226 local_bh_disable(); 1227 sock_prot_inuse_add(net, &xsk_proto, 1); 1228 local_bh_enable(); 1229 1230 return 0; 1231} 1232 1233static const struct net_proto_family xsk_family_ops = { 1234 .family = PF_XDP, 1235 .create = xsk_create, 1236 .owner = THIS_MODULE, 1237}; 1238 1239static struct notifier_block xsk_netdev_notifier = { 1240 .notifier_call = xsk_notifier, 1241}; 1242 1243static int __net_init xsk_net_init(struct net *net) 1244{ 1245 mutex_init(&net->xdp.lock); 1246 INIT_HLIST_HEAD(&net->xdp.list); 1247 return 0; 1248} 1249 1250static void __net_exit xsk_net_exit(struct net *net) 1251{ 1252 WARN_ON_ONCE(!hlist_empty(&net->xdp.list)); 1253} 1254 1255static struct pernet_operations xsk_net_ops = { 1256 .init = xsk_net_init, 1257 .exit = xsk_net_exit, 1258}; 1259 1260static int __init xsk_init(void) 1261{ 1262 int err, cpu; 1263 1264 err = proto_register(&xsk_proto, 0 /* no slab */); 1265 if (err) 1266 goto out; 1267 1268 err = sock_register(&xsk_family_ops); 1269 if (err) 1270 goto out_proto; 1271 1272 err = register_pernet_subsys(&xsk_net_ops); 1273 if (err) 1274 goto out_sk; 1275 1276 err = register_netdevice_notifier(&xsk_netdev_notifier); 1277 if (err) 1278 goto out_pernet; 1279 1280 for_each_possible_cpu(cpu) 1281 INIT_LIST_HEAD(&per_cpu(xskmap_flush_list, cpu)); 1282 return 0; 1283 1284out_pernet: 1285 unregister_pernet_subsys(&xsk_net_ops); 1286out_sk: 1287 sock_unregister(PF_XDP); 1288out_proto: 1289 proto_unregister(&xsk_proto); 1290out: 1291 return err; 1292} 1293 1294fs_initcall(xsk_init); 1295