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/busy_poll.h> 27 #include <net/xdp.h> 28 29 #include "xsk_queue.h" 30 #include "xdp_umem.h" 31 #include "xsk.h" 32 33 #define TX_BATCH_SIZE 16 34 35 static DEFINE_PER_CPU(struct list_head, xskmap_flush_list); 36 37 void xsk_set_rx_need_wakeup(struct xsk_buff_pool *pool) 38 { 39 if (pool->cached_need_wakeup & XDP_WAKEUP_RX) 40 return; 41 42 pool->fq->ring->flags |= XDP_RING_NEED_WAKEUP; 43 pool->cached_need_wakeup |= XDP_WAKEUP_RX; 44 } 45 EXPORT_SYMBOL(xsk_set_rx_need_wakeup); 46 47 void xsk_set_tx_need_wakeup(struct xsk_buff_pool *pool) 48 { 49 struct xdp_sock *xs; 50 51 if (pool->cached_need_wakeup & XDP_WAKEUP_TX) 52 return; 53 54 rcu_read_lock(); 55 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) { 56 xs->tx->ring->flags |= XDP_RING_NEED_WAKEUP; 57 } 58 rcu_read_unlock(); 59 60 pool->cached_need_wakeup |= XDP_WAKEUP_TX; 61 } 62 EXPORT_SYMBOL(xsk_set_tx_need_wakeup); 63 64 void xsk_clear_rx_need_wakeup(struct xsk_buff_pool *pool) 65 { 66 if (!(pool->cached_need_wakeup & XDP_WAKEUP_RX)) 67 return; 68 69 pool->fq->ring->flags &= ~XDP_RING_NEED_WAKEUP; 70 pool->cached_need_wakeup &= ~XDP_WAKEUP_RX; 71 } 72 EXPORT_SYMBOL(xsk_clear_rx_need_wakeup); 73 74 void xsk_clear_tx_need_wakeup(struct xsk_buff_pool *pool) 75 { 76 struct xdp_sock *xs; 77 78 if (!(pool->cached_need_wakeup & XDP_WAKEUP_TX)) 79 return; 80 81 rcu_read_lock(); 82 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) { 83 xs->tx->ring->flags &= ~XDP_RING_NEED_WAKEUP; 84 } 85 rcu_read_unlock(); 86 87 pool->cached_need_wakeup &= ~XDP_WAKEUP_TX; 88 } 89 EXPORT_SYMBOL(xsk_clear_tx_need_wakeup); 90 91 bool xsk_uses_need_wakeup(struct xsk_buff_pool *pool) 92 { 93 return pool->uses_need_wakeup; 94 } 95 EXPORT_SYMBOL(xsk_uses_need_wakeup); 96 97 struct xsk_buff_pool *xsk_get_pool_from_qid(struct net_device *dev, 98 u16 queue_id) 99 { 100 if (queue_id < dev->real_num_rx_queues) 101 return dev->_rx[queue_id].pool; 102 if (queue_id < dev->real_num_tx_queues) 103 return dev->_tx[queue_id].pool; 104 105 return NULL; 106 } 107 EXPORT_SYMBOL(xsk_get_pool_from_qid); 108 109 void xsk_clear_pool_at_qid(struct net_device *dev, u16 queue_id) 110 { 111 if (queue_id < dev->real_num_rx_queues) 112 dev->_rx[queue_id].pool = NULL; 113 if (queue_id < dev->real_num_tx_queues) 114 dev->_tx[queue_id].pool = NULL; 115 } 116 117 /* The buffer pool is stored both in the _rx struct and the _tx struct as we do 118 * not know if the device has more tx queues than rx, or the opposite. 119 * This might also change during run time. 120 */ 121 int xsk_reg_pool_at_qid(struct net_device *dev, struct xsk_buff_pool *pool, 122 u16 queue_id) 123 { 124 if (queue_id >= max_t(unsigned int, 125 dev->real_num_rx_queues, 126 dev->real_num_tx_queues)) 127 return -EINVAL; 128 129 if (queue_id < dev->real_num_rx_queues) 130 dev->_rx[queue_id].pool = pool; 131 if (queue_id < dev->real_num_tx_queues) 132 dev->_tx[queue_id].pool = pool; 133 134 return 0; 135 } 136 137 void xp_release(struct xdp_buff_xsk *xskb) 138 { 139 xskb->pool->free_heads[xskb->pool->free_heads_cnt++] = xskb; 140 } 141 142 static u64 xp_get_handle(struct xdp_buff_xsk *xskb) 143 { 144 u64 offset = xskb->xdp.data - xskb->xdp.data_hard_start; 145 146 offset += xskb->pool->headroom; 147 if (!xskb->pool->unaligned) 148 return xskb->orig_addr + offset; 149 return xskb->orig_addr + (offset << XSK_UNALIGNED_BUF_OFFSET_SHIFT); 150 } 151 152 static int __xsk_rcv_zc(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len) 153 { 154 struct xdp_buff_xsk *xskb = container_of(xdp, struct xdp_buff_xsk, xdp); 155 u64 addr; 156 int err; 157 158 addr = xp_get_handle(xskb); 159 err = xskq_prod_reserve_desc(xs->rx, addr, len); 160 if (err) { 161 xs->rx_queue_full++; 162 return err; 163 } 164 165 xp_release(xskb); 166 return 0; 167 } 168 169 static void xsk_copy_xdp(struct xdp_buff *to, struct xdp_buff *from, u32 len) 170 { 171 void *from_buf, *to_buf; 172 u32 metalen; 173 174 if (unlikely(xdp_data_meta_unsupported(from))) { 175 from_buf = from->data; 176 to_buf = to->data; 177 metalen = 0; 178 } else { 179 from_buf = from->data_meta; 180 metalen = from->data - from->data_meta; 181 to_buf = to->data - metalen; 182 } 183 184 memcpy(to_buf, from_buf, len + metalen); 185 } 186 187 static int __xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len, 188 bool explicit_free) 189 { 190 struct xdp_buff *xsk_xdp; 191 int err; 192 193 if (len > xsk_pool_get_rx_frame_size(xs->pool)) { 194 xs->rx_dropped++; 195 return -ENOSPC; 196 } 197 198 xsk_xdp = xsk_buff_alloc(xs->pool); 199 if (!xsk_xdp) { 200 xs->rx_dropped++; 201 return -ENOSPC; 202 } 203 204 xsk_copy_xdp(xsk_xdp, xdp, len); 205 err = __xsk_rcv_zc(xs, xsk_xdp, len); 206 if (err) { 207 xsk_buff_free(xsk_xdp); 208 return err; 209 } 210 if (explicit_free) 211 xdp_return_buff(xdp); 212 return 0; 213 } 214 215 static bool xsk_is_bound(struct xdp_sock *xs) 216 { 217 if (READ_ONCE(xs->state) == XSK_BOUND) { 218 /* Matches smp_wmb() in bind(). */ 219 smp_rmb(); 220 return true; 221 } 222 return false; 223 } 224 225 static int xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp, 226 bool explicit_free) 227 { 228 u32 len; 229 230 if (!xsk_is_bound(xs)) 231 return -EINVAL; 232 233 if (xs->dev != xdp->rxq->dev || xs->queue_id != xdp->rxq->queue_index) 234 return -EINVAL; 235 236 sk_mark_napi_id_once_xdp(&xs->sk, xdp); 237 len = xdp->data_end - xdp->data; 238 239 return xdp->rxq->mem.type == MEM_TYPE_XSK_BUFF_POOL ? 240 __xsk_rcv_zc(xs, xdp, len) : 241 __xsk_rcv(xs, xdp, len, explicit_free); 242 } 243 244 static void xsk_flush(struct xdp_sock *xs) 245 { 246 xskq_prod_submit(xs->rx); 247 __xskq_cons_release(xs->pool->fq); 248 sock_def_readable(&xs->sk); 249 } 250 251 int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp) 252 { 253 int err; 254 255 spin_lock_bh(&xs->rx_lock); 256 err = xsk_rcv(xs, xdp, false); 257 xsk_flush(xs); 258 spin_unlock_bh(&xs->rx_lock); 259 return err; 260 } 261 262 int __xsk_map_redirect(struct xdp_sock *xs, struct xdp_buff *xdp) 263 { 264 struct list_head *flush_list = this_cpu_ptr(&xskmap_flush_list); 265 int err; 266 267 err = xsk_rcv(xs, xdp, true); 268 if (err) 269 return err; 270 271 if (!xs->flush_node.prev) 272 list_add(&xs->flush_node, flush_list); 273 274 return 0; 275 } 276 277 void __xsk_map_flush(void) 278 { 279 struct list_head *flush_list = this_cpu_ptr(&xskmap_flush_list); 280 struct xdp_sock *xs, *tmp; 281 282 list_for_each_entry_safe(xs, tmp, flush_list, flush_node) { 283 xsk_flush(xs); 284 __list_del_clearprev(&xs->flush_node); 285 } 286 } 287 288 void xsk_tx_completed(struct xsk_buff_pool *pool, u32 nb_entries) 289 { 290 xskq_prod_submit_n(pool->cq, nb_entries); 291 } 292 EXPORT_SYMBOL(xsk_tx_completed); 293 294 void xsk_tx_release(struct xsk_buff_pool *pool) 295 { 296 struct xdp_sock *xs; 297 298 rcu_read_lock(); 299 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) { 300 __xskq_cons_release(xs->tx); 301 xs->sk.sk_write_space(&xs->sk); 302 } 303 rcu_read_unlock(); 304 } 305 EXPORT_SYMBOL(xsk_tx_release); 306 307 bool xsk_tx_peek_desc(struct xsk_buff_pool *pool, struct xdp_desc *desc) 308 { 309 struct xdp_sock *xs; 310 311 rcu_read_lock(); 312 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) { 313 if (!xskq_cons_peek_desc(xs->tx, desc, pool)) { 314 xs->tx->queue_empty_descs++; 315 continue; 316 } 317 318 /* This is the backpressure mechanism for the Tx path. 319 * Reserve space in the completion queue and only proceed 320 * if there is space in it. This avoids having to implement 321 * any buffering in the Tx path. 322 */ 323 if (xskq_prod_reserve_addr(pool->cq, desc->addr)) 324 goto out; 325 326 xskq_cons_release(xs->tx); 327 rcu_read_unlock(); 328 return true; 329 } 330 331 out: 332 rcu_read_unlock(); 333 return false; 334 } 335 EXPORT_SYMBOL(xsk_tx_peek_desc); 336 337 static u32 xsk_tx_peek_release_fallback(struct xsk_buff_pool *pool, struct xdp_desc *descs, 338 u32 max_entries) 339 { 340 u32 nb_pkts = 0; 341 342 while (nb_pkts < max_entries && xsk_tx_peek_desc(pool, &descs[nb_pkts])) 343 nb_pkts++; 344 345 xsk_tx_release(pool); 346 return nb_pkts; 347 } 348 349 u32 xsk_tx_peek_release_desc_batch(struct xsk_buff_pool *pool, struct xdp_desc *descs, 350 u32 max_entries) 351 { 352 struct xdp_sock *xs; 353 u32 nb_pkts; 354 355 rcu_read_lock(); 356 if (!list_is_singular(&pool->xsk_tx_list)) { 357 /* Fallback to the non-batched version */ 358 rcu_read_unlock(); 359 return xsk_tx_peek_release_fallback(pool, descs, max_entries); 360 } 361 362 xs = list_first_or_null_rcu(&pool->xsk_tx_list, struct xdp_sock, tx_list); 363 if (!xs) { 364 nb_pkts = 0; 365 goto out; 366 } 367 368 nb_pkts = xskq_cons_peek_desc_batch(xs->tx, descs, pool, max_entries); 369 if (!nb_pkts) { 370 xs->tx->queue_empty_descs++; 371 goto out; 372 } 373 374 /* This is the backpressure mechanism for the Tx path. Try to 375 * reserve space in the completion queue for all packets, but 376 * if there are fewer slots available, just process that many 377 * packets. This avoids having to implement any buffering in 378 * the Tx path. 379 */ 380 nb_pkts = xskq_prod_reserve_addr_batch(pool->cq, descs, nb_pkts); 381 if (!nb_pkts) 382 goto out; 383 384 xskq_cons_release_n(xs->tx, nb_pkts); 385 __xskq_cons_release(xs->tx); 386 xs->sk.sk_write_space(&xs->sk); 387 388 out: 389 rcu_read_unlock(); 390 return nb_pkts; 391 } 392 EXPORT_SYMBOL(xsk_tx_peek_release_desc_batch); 393 394 static int xsk_wakeup(struct xdp_sock *xs, u8 flags) 395 { 396 struct net_device *dev = xs->dev; 397 int err; 398 399 rcu_read_lock(); 400 err = dev->netdev_ops->ndo_xsk_wakeup(dev, xs->queue_id, flags); 401 rcu_read_unlock(); 402 403 return err; 404 } 405 406 static int xsk_zc_xmit(struct xdp_sock *xs) 407 { 408 return xsk_wakeup(xs, XDP_WAKEUP_TX); 409 } 410 411 static void xsk_destruct_skb(struct sk_buff *skb) 412 { 413 u64 addr = (u64)(long)skb_shinfo(skb)->destructor_arg; 414 struct xdp_sock *xs = xdp_sk(skb->sk); 415 unsigned long flags; 416 417 spin_lock_irqsave(&xs->tx_completion_lock, flags); 418 xskq_prod_submit_addr(xs->pool->cq, addr); 419 spin_unlock_irqrestore(&xs->tx_completion_lock, flags); 420 421 sock_wfree(skb); 422 } 423 424 static int xsk_generic_xmit(struct sock *sk) 425 { 426 struct xdp_sock *xs = xdp_sk(sk); 427 u32 max_batch = TX_BATCH_SIZE; 428 bool sent_frame = false; 429 struct xdp_desc desc; 430 struct sk_buff *skb; 431 int err = 0; 432 433 mutex_lock(&xs->mutex); 434 435 if (xs->queue_id >= xs->dev->real_num_tx_queues) 436 goto out; 437 438 while (xskq_cons_peek_desc(xs->tx, &desc, xs->pool)) { 439 char *buffer; 440 u64 addr; 441 u32 len; 442 443 if (max_batch-- == 0) { 444 err = -EAGAIN; 445 goto out; 446 } 447 448 len = desc.len; 449 skb = sock_alloc_send_skb(sk, len, 1, &err); 450 if (unlikely(!skb)) 451 goto out; 452 453 skb_put(skb, len); 454 addr = desc.addr; 455 buffer = xsk_buff_raw_get_data(xs->pool, addr); 456 err = skb_store_bits(skb, 0, buffer, len); 457 /* This is the backpressure mechanism for the Tx path. 458 * Reserve space in the completion queue and only proceed 459 * if there is space in it. This avoids having to implement 460 * any buffering in the Tx path. 461 */ 462 if (unlikely(err) || xskq_prod_reserve(xs->pool->cq)) { 463 kfree_skb(skb); 464 goto out; 465 } 466 467 skb->dev = xs->dev; 468 skb->priority = sk->sk_priority; 469 skb->mark = sk->sk_mark; 470 skb_shinfo(skb)->destructor_arg = (void *)(long)desc.addr; 471 skb->destructor = xsk_destruct_skb; 472 473 err = __dev_direct_xmit(skb, xs->queue_id); 474 if (err == NETDEV_TX_BUSY) { 475 /* Tell user-space to retry the send */ 476 skb->destructor = sock_wfree; 477 /* Free skb without triggering the perf drop trace */ 478 consume_skb(skb); 479 err = -EAGAIN; 480 goto out; 481 } 482 483 xskq_cons_release(xs->tx); 484 /* Ignore NET_XMIT_CN as packet might have been sent */ 485 if (err == NET_XMIT_DROP) { 486 /* SKB completed but not sent */ 487 err = -EBUSY; 488 goto out; 489 } 490 491 sent_frame = true; 492 } 493 494 xs->tx->queue_empty_descs++; 495 496 out: 497 if (sent_frame) 498 sk->sk_write_space(sk); 499 500 mutex_unlock(&xs->mutex); 501 return err; 502 } 503 504 static int __xsk_sendmsg(struct sock *sk) 505 { 506 struct xdp_sock *xs = xdp_sk(sk); 507 508 if (unlikely(!(xs->dev->flags & IFF_UP))) 509 return -ENETDOWN; 510 if (unlikely(!xs->tx)) 511 return -ENOBUFS; 512 513 return xs->zc ? xsk_zc_xmit(xs) : xsk_generic_xmit(sk); 514 } 515 516 static bool xsk_no_wakeup(struct sock *sk) 517 { 518 #ifdef CONFIG_NET_RX_BUSY_POLL 519 /* Prefer busy-polling, skip the wakeup. */ 520 return READ_ONCE(sk->sk_prefer_busy_poll) && READ_ONCE(sk->sk_ll_usec) && 521 READ_ONCE(sk->sk_napi_id) >= MIN_NAPI_ID; 522 #else 523 return false; 524 #endif 525 } 526 527 static int xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len) 528 { 529 bool need_wait = !(m->msg_flags & MSG_DONTWAIT); 530 struct sock *sk = sock->sk; 531 struct xdp_sock *xs = xdp_sk(sk); 532 struct xsk_buff_pool *pool; 533 534 if (unlikely(!xsk_is_bound(xs))) 535 return -ENXIO; 536 if (unlikely(need_wait)) 537 return -EOPNOTSUPP; 538 539 if (sk_can_busy_loop(sk)) 540 sk_busy_loop(sk, 1); /* only support non-blocking sockets */ 541 542 if (xsk_no_wakeup(sk)) 543 return 0; 544 545 pool = xs->pool; 546 if (pool->cached_need_wakeup & XDP_WAKEUP_TX) 547 return __xsk_sendmsg(sk); 548 return 0; 549 } 550 551 static int xsk_recvmsg(struct socket *sock, struct msghdr *m, size_t len, int flags) 552 { 553 bool need_wait = !(flags & MSG_DONTWAIT); 554 struct sock *sk = sock->sk; 555 struct xdp_sock *xs = xdp_sk(sk); 556 557 if (unlikely(!(xs->dev->flags & IFF_UP))) 558 return -ENETDOWN; 559 if (unlikely(!xs->rx)) 560 return -ENOBUFS; 561 if (unlikely(!xsk_is_bound(xs))) 562 return -ENXIO; 563 if (unlikely(need_wait)) 564 return -EOPNOTSUPP; 565 566 if (sk_can_busy_loop(sk)) 567 sk_busy_loop(sk, 1); /* only support non-blocking sockets */ 568 569 if (xsk_no_wakeup(sk)) 570 return 0; 571 572 if (xs->pool->cached_need_wakeup & XDP_WAKEUP_RX && xs->zc) 573 return xsk_wakeup(xs, XDP_WAKEUP_RX); 574 return 0; 575 } 576 577 static __poll_t xsk_poll(struct file *file, struct socket *sock, 578 struct poll_table_struct *wait) 579 { 580 __poll_t mask = datagram_poll(file, sock, wait); 581 struct sock *sk = sock->sk; 582 struct xdp_sock *xs = xdp_sk(sk); 583 struct xsk_buff_pool *pool; 584 585 if (unlikely(!xsk_is_bound(xs))) 586 return mask; 587 588 pool = xs->pool; 589 590 if (pool->cached_need_wakeup) { 591 if (xs->zc) 592 xsk_wakeup(xs, pool->cached_need_wakeup); 593 else 594 /* Poll needs to drive Tx also in copy mode */ 595 __xsk_sendmsg(sk); 596 } 597 598 if (xs->rx && !xskq_prod_is_empty(xs->rx)) 599 mask |= EPOLLIN | EPOLLRDNORM; 600 if (xs->tx && !xskq_cons_is_full(xs->tx)) 601 mask |= EPOLLOUT | EPOLLWRNORM; 602 603 return mask; 604 } 605 606 static int xsk_init_queue(u32 entries, struct xsk_queue **queue, 607 bool umem_queue) 608 { 609 struct xsk_queue *q; 610 611 if (entries == 0 || *queue || !is_power_of_2(entries)) 612 return -EINVAL; 613 614 q = xskq_create(entries, umem_queue); 615 if (!q) 616 return -ENOMEM; 617 618 /* Make sure queue is ready before it can be seen by others */ 619 smp_wmb(); 620 WRITE_ONCE(*queue, q); 621 return 0; 622 } 623 624 static void xsk_unbind_dev(struct xdp_sock *xs) 625 { 626 struct net_device *dev = xs->dev; 627 628 if (xs->state != XSK_BOUND) 629 return; 630 WRITE_ONCE(xs->state, XSK_UNBOUND); 631 632 /* Wait for driver to stop using the xdp socket. */ 633 xp_del_xsk(xs->pool, xs); 634 xs->dev = NULL; 635 synchronize_net(); 636 dev_put(dev); 637 } 638 639 static struct xsk_map *xsk_get_map_list_entry(struct xdp_sock *xs, 640 struct xdp_sock ***map_entry) 641 { 642 struct xsk_map *map = NULL; 643 struct xsk_map_node *node; 644 645 *map_entry = NULL; 646 647 spin_lock_bh(&xs->map_list_lock); 648 node = list_first_entry_or_null(&xs->map_list, struct xsk_map_node, 649 node); 650 if (node) { 651 bpf_map_inc(&node->map->map); 652 map = node->map; 653 *map_entry = node->map_entry; 654 } 655 spin_unlock_bh(&xs->map_list_lock); 656 return map; 657 } 658 659 static void xsk_delete_from_maps(struct xdp_sock *xs) 660 { 661 /* This function removes the current XDP socket from all the 662 * maps it resides in. We need to take extra care here, due to 663 * the two locks involved. Each map has a lock synchronizing 664 * updates to the entries, and each socket has a lock that 665 * synchronizes access to the list of maps (map_list). For 666 * deadlock avoidance the locks need to be taken in the order 667 * "map lock"->"socket map list lock". We start off by 668 * accessing the socket map list, and take a reference to the 669 * map to guarantee existence between the 670 * xsk_get_map_list_entry() and xsk_map_try_sock_delete() 671 * calls. Then we ask the map to remove the socket, which 672 * tries to remove the socket from the map. Note that there 673 * might be updates to the map between 674 * xsk_get_map_list_entry() and xsk_map_try_sock_delete(). 675 */ 676 struct xdp_sock **map_entry = NULL; 677 struct xsk_map *map; 678 679 while ((map = xsk_get_map_list_entry(xs, &map_entry))) { 680 xsk_map_try_sock_delete(map, xs, map_entry); 681 bpf_map_put(&map->map); 682 } 683 } 684 685 static int xsk_release(struct socket *sock) 686 { 687 struct sock *sk = sock->sk; 688 struct xdp_sock *xs = xdp_sk(sk); 689 struct net *net; 690 691 if (!sk) 692 return 0; 693 694 net = sock_net(sk); 695 696 mutex_lock(&net->xdp.lock); 697 sk_del_node_init_rcu(sk); 698 mutex_unlock(&net->xdp.lock); 699 700 local_bh_disable(); 701 sock_prot_inuse_add(net, sk->sk_prot, -1); 702 local_bh_enable(); 703 704 xsk_delete_from_maps(xs); 705 mutex_lock(&xs->mutex); 706 xsk_unbind_dev(xs); 707 mutex_unlock(&xs->mutex); 708 709 xskq_destroy(xs->rx); 710 xskq_destroy(xs->tx); 711 xskq_destroy(xs->fq_tmp); 712 xskq_destroy(xs->cq_tmp); 713 714 sock_orphan(sk); 715 sock->sk = NULL; 716 717 sk_refcnt_debug_release(sk); 718 sock_put(sk); 719 720 return 0; 721 } 722 723 static struct socket *xsk_lookup_xsk_from_fd(int fd) 724 { 725 struct socket *sock; 726 int err; 727 728 sock = sockfd_lookup(fd, &err); 729 if (!sock) 730 return ERR_PTR(-ENOTSOCK); 731 732 if (sock->sk->sk_family != PF_XDP) { 733 sockfd_put(sock); 734 return ERR_PTR(-ENOPROTOOPT); 735 } 736 737 return sock; 738 } 739 740 static bool xsk_validate_queues(struct xdp_sock *xs) 741 { 742 return xs->fq_tmp && xs->cq_tmp; 743 } 744 745 static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len) 746 { 747 struct sockaddr_xdp *sxdp = (struct sockaddr_xdp *)addr; 748 struct sock *sk = sock->sk; 749 struct xdp_sock *xs = xdp_sk(sk); 750 struct net_device *dev; 751 u32 flags, qid; 752 int err = 0; 753 754 if (addr_len < sizeof(struct sockaddr_xdp)) 755 return -EINVAL; 756 if (sxdp->sxdp_family != AF_XDP) 757 return -EINVAL; 758 759 flags = sxdp->sxdp_flags; 760 if (flags & ~(XDP_SHARED_UMEM | XDP_COPY | XDP_ZEROCOPY | 761 XDP_USE_NEED_WAKEUP)) 762 return -EINVAL; 763 764 rtnl_lock(); 765 mutex_lock(&xs->mutex); 766 if (xs->state != XSK_READY) { 767 err = -EBUSY; 768 goto out_release; 769 } 770 771 dev = dev_get_by_index(sock_net(sk), sxdp->sxdp_ifindex); 772 if (!dev) { 773 err = -ENODEV; 774 goto out_release; 775 } 776 777 if (!xs->rx && !xs->tx) { 778 err = -EINVAL; 779 goto out_unlock; 780 } 781 782 qid = sxdp->sxdp_queue_id; 783 784 if (flags & XDP_SHARED_UMEM) { 785 struct xdp_sock *umem_xs; 786 struct socket *sock; 787 788 if ((flags & XDP_COPY) || (flags & XDP_ZEROCOPY) || 789 (flags & XDP_USE_NEED_WAKEUP)) { 790 /* Cannot specify flags for shared sockets. */ 791 err = -EINVAL; 792 goto out_unlock; 793 } 794 795 if (xs->umem) { 796 /* We have already our own. */ 797 err = -EINVAL; 798 goto out_unlock; 799 } 800 801 sock = xsk_lookup_xsk_from_fd(sxdp->sxdp_shared_umem_fd); 802 if (IS_ERR(sock)) { 803 err = PTR_ERR(sock); 804 goto out_unlock; 805 } 806 807 umem_xs = xdp_sk(sock->sk); 808 if (!xsk_is_bound(umem_xs)) { 809 err = -EBADF; 810 sockfd_put(sock); 811 goto out_unlock; 812 } 813 814 if (umem_xs->queue_id != qid || umem_xs->dev != dev) { 815 /* Share the umem with another socket on another qid 816 * and/or device. 817 */ 818 xs->pool = xp_create_and_assign_umem(xs, 819 umem_xs->umem); 820 if (!xs->pool) { 821 err = -ENOMEM; 822 sockfd_put(sock); 823 goto out_unlock; 824 } 825 826 err = xp_assign_dev_shared(xs->pool, umem_xs->umem, 827 dev, qid); 828 if (err) { 829 xp_destroy(xs->pool); 830 xs->pool = NULL; 831 sockfd_put(sock); 832 goto out_unlock; 833 } 834 } else { 835 /* Share the buffer pool with the other socket. */ 836 if (xs->fq_tmp || xs->cq_tmp) { 837 /* Do not allow setting your own fq or cq. */ 838 err = -EINVAL; 839 sockfd_put(sock); 840 goto out_unlock; 841 } 842 843 xp_get_pool(umem_xs->pool); 844 xs->pool = umem_xs->pool; 845 } 846 847 xdp_get_umem(umem_xs->umem); 848 WRITE_ONCE(xs->umem, umem_xs->umem); 849 sockfd_put(sock); 850 } else if (!xs->umem || !xsk_validate_queues(xs)) { 851 err = -EINVAL; 852 goto out_unlock; 853 } else { 854 /* This xsk has its own umem. */ 855 xs->pool = xp_create_and_assign_umem(xs, xs->umem); 856 if (!xs->pool) { 857 err = -ENOMEM; 858 goto out_unlock; 859 } 860 861 err = xp_assign_dev(xs->pool, dev, qid, flags); 862 if (err) { 863 xp_destroy(xs->pool); 864 xs->pool = NULL; 865 goto out_unlock; 866 } 867 } 868 869 xs->dev = dev; 870 xs->zc = xs->umem->zc; 871 xs->queue_id = qid; 872 xp_add_xsk(xs->pool, xs); 873 874 out_unlock: 875 if (err) { 876 dev_put(dev); 877 } else { 878 /* Matches smp_rmb() in bind() for shared umem 879 * sockets, and xsk_is_bound(). 880 */ 881 smp_wmb(); 882 WRITE_ONCE(xs->state, XSK_BOUND); 883 } 884 out_release: 885 mutex_unlock(&xs->mutex); 886 rtnl_unlock(); 887 return err; 888 } 889 890 struct xdp_umem_reg_v1 { 891 __u64 addr; /* Start of packet data area */ 892 __u64 len; /* Length of packet data area */ 893 __u32 chunk_size; 894 __u32 headroom; 895 }; 896 897 static int xsk_setsockopt(struct socket *sock, int level, int optname, 898 sockptr_t optval, unsigned int optlen) 899 { 900 struct sock *sk = sock->sk; 901 struct xdp_sock *xs = xdp_sk(sk); 902 int err; 903 904 if (level != SOL_XDP) 905 return -ENOPROTOOPT; 906 907 switch (optname) { 908 case XDP_RX_RING: 909 case XDP_TX_RING: 910 { 911 struct xsk_queue **q; 912 int entries; 913 914 if (optlen < sizeof(entries)) 915 return -EINVAL; 916 if (copy_from_sockptr(&entries, optval, sizeof(entries))) 917 return -EFAULT; 918 919 mutex_lock(&xs->mutex); 920 if (xs->state != XSK_READY) { 921 mutex_unlock(&xs->mutex); 922 return -EBUSY; 923 } 924 q = (optname == XDP_TX_RING) ? &xs->tx : &xs->rx; 925 err = xsk_init_queue(entries, q, false); 926 if (!err && optname == XDP_TX_RING) 927 /* Tx needs to be explicitly woken up the first time */ 928 xs->tx->ring->flags |= XDP_RING_NEED_WAKEUP; 929 mutex_unlock(&xs->mutex); 930 return err; 931 } 932 case XDP_UMEM_REG: 933 { 934 size_t mr_size = sizeof(struct xdp_umem_reg); 935 struct xdp_umem_reg mr = {}; 936 struct xdp_umem *umem; 937 938 if (optlen < sizeof(struct xdp_umem_reg_v1)) 939 return -EINVAL; 940 else if (optlen < sizeof(mr)) 941 mr_size = sizeof(struct xdp_umem_reg_v1); 942 943 if (copy_from_sockptr(&mr, optval, mr_size)) 944 return -EFAULT; 945 946 mutex_lock(&xs->mutex); 947 if (xs->state != XSK_READY || xs->umem) { 948 mutex_unlock(&xs->mutex); 949 return -EBUSY; 950 } 951 952 umem = xdp_umem_create(&mr); 953 if (IS_ERR(umem)) { 954 mutex_unlock(&xs->mutex); 955 return PTR_ERR(umem); 956 } 957 958 /* Make sure umem is ready before it can be seen by others */ 959 smp_wmb(); 960 WRITE_ONCE(xs->umem, umem); 961 mutex_unlock(&xs->mutex); 962 return 0; 963 } 964 case XDP_UMEM_FILL_RING: 965 case XDP_UMEM_COMPLETION_RING: 966 { 967 struct xsk_queue **q; 968 int entries; 969 970 if (copy_from_sockptr(&entries, optval, sizeof(entries))) 971 return -EFAULT; 972 973 mutex_lock(&xs->mutex); 974 if (xs->state != XSK_READY) { 975 mutex_unlock(&xs->mutex); 976 return -EBUSY; 977 } 978 979 q = (optname == XDP_UMEM_FILL_RING) ? &xs->fq_tmp : 980 &xs->cq_tmp; 981 err = xsk_init_queue(entries, q, true); 982 mutex_unlock(&xs->mutex); 983 return err; 984 } 985 default: 986 break; 987 } 988 989 return -ENOPROTOOPT; 990 } 991 992 static void xsk_enter_rxtx_offsets(struct xdp_ring_offset_v1 *ring) 993 { 994 ring->producer = offsetof(struct xdp_rxtx_ring, ptrs.producer); 995 ring->consumer = offsetof(struct xdp_rxtx_ring, ptrs.consumer); 996 ring->desc = offsetof(struct xdp_rxtx_ring, desc); 997 } 998 999 static void xsk_enter_umem_offsets(struct xdp_ring_offset_v1 *ring) 1000 { 1001 ring->producer = offsetof(struct xdp_umem_ring, ptrs.producer); 1002 ring->consumer = offsetof(struct xdp_umem_ring, ptrs.consumer); 1003 ring->desc = offsetof(struct xdp_umem_ring, desc); 1004 } 1005 1006 struct xdp_statistics_v1 { 1007 __u64 rx_dropped; 1008 __u64 rx_invalid_descs; 1009 __u64 tx_invalid_descs; 1010 }; 1011 1012 static int xsk_getsockopt(struct socket *sock, int level, int optname, 1013 char __user *optval, int __user *optlen) 1014 { 1015 struct sock *sk = sock->sk; 1016 struct xdp_sock *xs = xdp_sk(sk); 1017 int len; 1018 1019 if (level != SOL_XDP) 1020 return -ENOPROTOOPT; 1021 1022 if (get_user(len, optlen)) 1023 return -EFAULT; 1024 if (len < 0) 1025 return -EINVAL; 1026 1027 switch (optname) { 1028 case XDP_STATISTICS: 1029 { 1030 struct xdp_statistics stats = {}; 1031 bool extra_stats = true; 1032 size_t stats_size; 1033 1034 if (len < sizeof(struct xdp_statistics_v1)) { 1035 return -EINVAL; 1036 } else if (len < sizeof(stats)) { 1037 extra_stats = false; 1038 stats_size = sizeof(struct xdp_statistics_v1); 1039 } else { 1040 stats_size = sizeof(stats); 1041 } 1042 1043 mutex_lock(&xs->mutex); 1044 stats.rx_dropped = xs->rx_dropped; 1045 if (extra_stats) { 1046 stats.rx_ring_full = xs->rx_queue_full; 1047 stats.rx_fill_ring_empty_descs = 1048 xs->pool ? xskq_nb_queue_empty_descs(xs->pool->fq) : 0; 1049 stats.tx_ring_empty_descs = xskq_nb_queue_empty_descs(xs->tx); 1050 } else { 1051 stats.rx_dropped += xs->rx_queue_full; 1052 } 1053 stats.rx_invalid_descs = xskq_nb_invalid_descs(xs->rx); 1054 stats.tx_invalid_descs = xskq_nb_invalid_descs(xs->tx); 1055 mutex_unlock(&xs->mutex); 1056 1057 if (copy_to_user(optval, &stats, stats_size)) 1058 return -EFAULT; 1059 if (put_user(stats_size, optlen)) 1060 return -EFAULT; 1061 1062 return 0; 1063 } 1064 case XDP_MMAP_OFFSETS: 1065 { 1066 struct xdp_mmap_offsets off; 1067 struct xdp_mmap_offsets_v1 off_v1; 1068 bool flags_supported = true; 1069 void *to_copy; 1070 1071 if (len < sizeof(off_v1)) 1072 return -EINVAL; 1073 else if (len < sizeof(off)) 1074 flags_supported = false; 1075 1076 if (flags_supported) { 1077 /* xdp_ring_offset is identical to xdp_ring_offset_v1 1078 * except for the flags field added to the end. 1079 */ 1080 xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *) 1081 &off.rx); 1082 xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *) 1083 &off.tx); 1084 xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *) 1085 &off.fr); 1086 xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *) 1087 &off.cr); 1088 off.rx.flags = offsetof(struct xdp_rxtx_ring, 1089 ptrs.flags); 1090 off.tx.flags = offsetof(struct xdp_rxtx_ring, 1091 ptrs.flags); 1092 off.fr.flags = offsetof(struct xdp_umem_ring, 1093 ptrs.flags); 1094 off.cr.flags = offsetof(struct xdp_umem_ring, 1095 ptrs.flags); 1096 1097 len = sizeof(off); 1098 to_copy = &off; 1099 } else { 1100 xsk_enter_rxtx_offsets(&off_v1.rx); 1101 xsk_enter_rxtx_offsets(&off_v1.tx); 1102 xsk_enter_umem_offsets(&off_v1.fr); 1103 xsk_enter_umem_offsets(&off_v1.cr); 1104 1105 len = sizeof(off_v1); 1106 to_copy = &off_v1; 1107 } 1108 1109 if (copy_to_user(optval, to_copy, len)) 1110 return -EFAULT; 1111 if (put_user(len, optlen)) 1112 return -EFAULT; 1113 1114 return 0; 1115 } 1116 case XDP_OPTIONS: 1117 { 1118 struct xdp_options opts = {}; 1119 1120 if (len < sizeof(opts)) 1121 return -EINVAL; 1122 1123 mutex_lock(&xs->mutex); 1124 if (xs->zc) 1125 opts.flags |= XDP_OPTIONS_ZEROCOPY; 1126 mutex_unlock(&xs->mutex); 1127 1128 len = sizeof(opts); 1129 if (copy_to_user(optval, &opts, len)) 1130 return -EFAULT; 1131 if (put_user(len, optlen)) 1132 return -EFAULT; 1133 1134 return 0; 1135 } 1136 default: 1137 break; 1138 } 1139 1140 return -EOPNOTSUPP; 1141 } 1142 1143 static int xsk_mmap(struct file *file, struct socket *sock, 1144 struct vm_area_struct *vma) 1145 { 1146 loff_t offset = (loff_t)vma->vm_pgoff << PAGE_SHIFT; 1147 unsigned long size = vma->vm_end - vma->vm_start; 1148 struct xdp_sock *xs = xdp_sk(sock->sk); 1149 struct xsk_queue *q = NULL; 1150 unsigned long pfn; 1151 struct page *qpg; 1152 1153 if (READ_ONCE(xs->state) != XSK_READY) 1154 return -EBUSY; 1155 1156 if (offset == XDP_PGOFF_RX_RING) { 1157 q = READ_ONCE(xs->rx); 1158 } else if (offset == XDP_PGOFF_TX_RING) { 1159 q = READ_ONCE(xs->tx); 1160 } else { 1161 /* Matches the smp_wmb() in XDP_UMEM_REG */ 1162 smp_rmb(); 1163 if (offset == XDP_UMEM_PGOFF_FILL_RING) 1164 q = READ_ONCE(xs->fq_tmp); 1165 else if (offset == XDP_UMEM_PGOFF_COMPLETION_RING) 1166 q = READ_ONCE(xs->cq_tmp); 1167 } 1168 1169 if (!q) 1170 return -EINVAL; 1171 1172 /* Matches the smp_wmb() in xsk_init_queue */ 1173 smp_rmb(); 1174 qpg = virt_to_head_page(q->ring); 1175 if (size > page_size(qpg)) 1176 return -EINVAL; 1177 1178 pfn = virt_to_phys(q->ring) >> PAGE_SHIFT; 1179 return remap_pfn_range(vma, vma->vm_start, pfn, 1180 size, vma->vm_page_prot); 1181 } 1182 1183 static int xsk_notifier(struct notifier_block *this, 1184 unsigned long msg, void *ptr) 1185 { 1186 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1187 struct net *net = dev_net(dev); 1188 struct sock *sk; 1189 1190 switch (msg) { 1191 case NETDEV_UNREGISTER: 1192 mutex_lock(&net->xdp.lock); 1193 sk_for_each(sk, &net->xdp.list) { 1194 struct xdp_sock *xs = xdp_sk(sk); 1195 1196 mutex_lock(&xs->mutex); 1197 if (xs->dev == dev) { 1198 sk->sk_err = ENETDOWN; 1199 if (!sock_flag(sk, SOCK_DEAD)) 1200 sk->sk_error_report(sk); 1201 1202 xsk_unbind_dev(xs); 1203 1204 /* Clear device references. */ 1205 xp_clear_dev(xs->pool); 1206 } 1207 mutex_unlock(&xs->mutex); 1208 } 1209 mutex_unlock(&net->xdp.lock); 1210 break; 1211 } 1212 return NOTIFY_DONE; 1213 } 1214 1215 static struct proto xsk_proto = { 1216 .name = "XDP", 1217 .owner = THIS_MODULE, 1218 .obj_size = sizeof(struct xdp_sock), 1219 }; 1220 1221 static const struct proto_ops xsk_proto_ops = { 1222 .family = PF_XDP, 1223 .owner = THIS_MODULE, 1224 .release = xsk_release, 1225 .bind = xsk_bind, 1226 .connect = sock_no_connect, 1227 .socketpair = sock_no_socketpair, 1228 .accept = sock_no_accept, 1229 .getname = sock_no_getname, 1230 .poll = xsk_poll, 1231 .ioctl = sock_no_ioctl, 1232 .listen = sock_no_listen, 1233 .shutdown = sock_no_shutdown, 1234 .setsockopt = xsk_setsockopt, 1235 .getsockopt = xsk_getsockopt, 1236 .sendmsg = xsk_sendmsg, 1237 .recvmsg = xsk_recvmsg, 1238 .mmap = xsk_mmap, 1239 .sendpage = sock_no_sendpage, 1240 }; 1241 1242 static void xsk_destruct(struct sock *sk) 1243 { 1244 struct xdp_sock *xs = xdp_sk(sk); 1245 1246 if (!sock_flag(sk, SOCK_DEAD)) 1247 return; 1248 1249 if (!xp_put_pool(xs->pool)) 1250 xdp_put_umem(xs->umem, !xs->pool); 1251 1252 sk_refcnt_debug_dec(sk); 1253 } 1254 1255 static int xsk_create(struct net *net, struct socket *sock, int protocol, 1256 int kern) 1257 { 1258 struct xdp_sock *xs; 1259 struct sock *sk; 1260 1261 if (!ns_capable(net->user_ns, CAP_NET_RAW)) 1262 return -EPERM; 1263 if (sock->type != SOCK_RAW) 1264 return -ESOCKTNOSUPPORT; 1265 1266 if (protocol) 1267 return -EPROTONOSUPPORT; 1268 1269 sock->state = SS_UNCONNECTED; 1270 1271 sk = sk_alloc(net, PF_XDP, GFP_KERNEL, &xsk_proto, kern); 1272 if (!sk) 1273 return -ENOBUFS; 1274 1275 sock->ops = &xsk_proto_ops; 1276 1277 sock_init_data(sock, sk); 1278 1279 sk->sk_family = PF_XDP; 1280 1281 sk->sk_destruct = xsk_destruct; 1282 sk_refcnt_debug_inc(sk); 1283 1284 sock_set_flag(sk, SOCK_RCU_FREE); 1285 1286 xs = xdp_sk(sk); 1287 xs->state = XSK_READY; 1288 mutex_init(&xs->mutex); 1289 spin_lock_init(&xs->rx_lock); 1290 spin_lock_init(&xs->tx_completion_lock); 1291 1292 INIT_LIST_HEAD(&xs->map_list); 1293 spin_lock_init(&xs->map_list_lock); 1294 1295 mutex_lock(&net->xdp.lock); 1296 sk_add_node_rcu(sk, &net->xdp.list); 1297 mutex_unlock(&net->xdp.lock); 1298 1299 local_bh_disable(); 1300 sock_prot_inuse_add(net, &xsk_proto, 1); 1301 local_bh_enable(); 1302 1303 return 0; 1304 } 1305 1306 static const struct net_proto_family xsk_family_ops = { 1307 .family = PF_XDP, 1308 .create = xsk_create, 1309 .owner = THIS_MODULE, 1310 }; 1311 1312 static struct notifier_block xsk_netdev_notifier = { 1313 .notifier_call = xsk_notifier, 1314 }; 1315 1316 static int __net_init xsk_net_init(struct net *net) 1317 { 1318 mutex_init(&net->xdp.lock); 1319 INIT_HLIST_HEAD(&net->xdp.list); 1320 return 0; 1321 } 1322 1323 static void __net_exit xsk_net_exit(struct net *net) 1324 { 1325 WARN_ON_ONCE(!hlist_empty(&net->xdp.list)); 1326 } 1327 1328 static struct pernet_operations xsk_net_ops = { 1329 .init = xsk_net_init, 1330 .exit = xsk_net_exit, 1331 }; 1332 1333 static int __init xsk_init(void) 1334 { 1335 int err, cpu; 1336 1337 err = proto_register(&xsk_proto, 0 /* no slab */); 1338 if (err) 1339 goto out; 1340 1341 err = sock_register(&xsk_family_ops); 1342 if (err) 1343 goto out_proto; 1344 1345 err = register_pernet_subsys(&xsk_net_ops); 1346 if (err) 1347 goto out_sk; 1348 1349 err = register_netdevice_notifier(&xsk_netdev_notifier); 1350 if (err) 1351 goto out_pernet; 1352 1353 for_each_possible_cpu(cpu) 1354 INIT_LIST_HEAD(&per_cpu(xskmap_flush_list, cpu)); 1355 return 0; 1356 1357 out_pernet: 1358 unregister_pernet_subsys(&xsk_net_ops); 1359 out_sk: 1360 sock_unregister(PF_XDP); 1361 out_proto: 1362 proto_unregister(&xsk_proto); 1363 out: 1364 return err; 1365 } 1366 1367 fs_initcall(xsk_init); 1368