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.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 bool xsk_is_setup_for_bpf_map(struct xdp_sock *xs) 35 { 36 return READ_ONCE(xs->rx) && READ_ONCE(xs->umem) && 37 READ_ONCE(xs->umem->fq); 38 } 39 40 bool xsk_umem_has_addrs(struct xdp_umem *umem, u32 cnt) 41 { 42 return xskq_has_addrs(umem->fq, cnt); 43 } 44 EXPORT_SYMBOL(xsk_umem_has_addrs); 45 46 u64 *xsk_umem_peek_addr(struct xdp_umem *umem, u64 *addr) 47 { 48 return xskq_peek_addr(umem->fq, addr, umem); 49 } 50 EXPORT_SYMBOL(xsk_umem_peek_addr); 51 52 void xsk_umem_discard_addr(struct xdp_umem *umem) 53 { 54 xskq_discard_addr(umem->fq); 55 } 56 EXPORT_SYMBOL(xsk_umem_discard_addr); 57 58 void xsk_set_rx_need_wakeup(struct xdp_umem *umem) 59 { 60 if (umem->need_wakeup & XDP_WAKEUP_RX) 61 return; 62 63 umem->fq->ring->flags |= XDP_RING_NEED_WAKEUP; 64 umem->need_wakeup |= XDP_WAKEUP_RX; 65 } 66 EXPORT_SYMBOL(xsk_set_rx_need_wakeup); 67 68 void xsk_set_tx_need_wakeup(struct xdp_umem *umem) 69 { 70 struct xdp_sock *xs; 71 72 if (umem->need_wakeup & XDP_WAKEUP_TX) 73 return; 74 75 rcu_read_lock(); 76 list_for_each_entry_rcu(xs, &umem->xsk_list, list) { 77 xs->tx->ring->flags |= XDP_RING_NEED_WAKEUP; 78 } 79 rcu_read_unlock(); 80 81 umem->need_wakeup |= XDP_WAKEUP_TX; 82 } 83 EXPORT_SYMBOL(xsk_set_tx_need_wakeup); 84 85 void xsk_clear_rx_need_wakeup(struct xdp_umem *umem) 86 { 87 if (!(umem->need_wakeup & XDP_WAKEUP_RX)) 88 return; 89 90 umem->fq->ring->flags &= ~XDP_RING_NEED_WAKEUP; 91 umem->need_wakeup &= ~XDP_WAKEUP_RX; 92 } 93 EXPORT_SYMBOL(xsk_clear_rx_need_wakeup); 94 95 void xsk_clear_tx_need_wakeup(struct xdp_umem *umem) 96 { 97 struct xdp_sock *xs; 98 99 if (!(umem->need_wakeup & XDP_WAKEUP_TX)) 100 return; 101 102 rcu_read_lock(); 103 list_for_each_entry_rcu(xs, &umem->xsk_list, list) { 104 xs->tx->ring->flags &= ~XDP_RING_NEED_WAKEUP; 105 } 106 rcu_read_unlock(); 107 108 umem->need_wakeup &= ~XDP_WAKEUP_TX; 109 } 110 EXPORT_SYMBOL(xsk_clear_tx_need_wakeup); 111 112 bool xsk_umem_uses_need_wakeup(struct xdp_umem *umem) 113 { 114 return umem->flags & XDP_UMEM_USES_NEED_WAKEUP; 115 } 116 EXPORT_SYMBOL(xsk_umem_uses_need_wakeup); 117 118 /* If a buffer crosses a page boundary, we need to do 2 memcpy's, one for 119 * each page. This is only required in copy mode. 120 */ 121 static void __xsk_rcv_memcpy(struct xdp_umem *umem, u64 addr, void *from_buf, 122 u32 len, u32 metalen) 123 { 124 void *to_buf = xdp_umem_get_data(umem, addr); 125 126 addr = xsk_umem_add_offset_to_addr(addr); 127 if (xskq_crosses_non_contig_pg(umem, addr, len + metalen)) { 128 void *next_pg_addr = umem->pages[(addr >> PAGE_SHIFT) + 1].addr; 129 u64 page_start = addr & ~(PAGE_SIZE - 1); 130 u64 first_len = PAGE_SIZE - (addr - page_start); 131 132 memcpy(to_buf, from_buf, first_len + metalen); 133 memcpy(next_pg_addr, from_buf + first_len, len - first_len); 134 135 return; 136 } 137 138 memcpy(to_buf, from_buf, len + metalen); 139 } 140 141 static int __xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len) 142 { 143 u64 offset = xs->umem->headroom; 144 u64 addr, memcpy_addr; 145 void *from_buf; 146 u32 metalen; 147 int err; 148 149 if (!xskq_peek_addr(xs->umem->fq, &addr, xs->umem) || 150 len > xs->umem->chunk_size_nohr - XDP_PACKET_HEADROOM) { 151 xs->rx_dropped++; 152 return -ENOSPC; 153 } 154 155 if (unlikely(xdp_data_meta_unsupported(xdp))) { 156 from_buf = xdp->data; 157 metalen = 0; 158 } else { 159 from_buf = xdp->data_meta; 160 metalen = xdp->data - xdp->data_meta; 161 } 162 163 memcpy_addr = xsk_umem_adjust_offset(xs->umem, addr, offset); 164 __xsk_rcv_memcpy(xs->umem, memcpy_addr, from_buf, len, metalen); 165 166 offset += metalen; 167 addr = xsk_umem_adjust_offset(xs->umem, addr, offset); 168 err = xskq_produce_batch_desc(xs->rx, addr, len); 169 if (!err) { 170 xskq_discard_addr(xs->umem->fq); 171 xdp_return_buff(xdp); 172 return 0; 173 } 174 175 xs->rx_dropped++; 176 return err; 177 } 178 179 static int __xsk_rcv_zc(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len) 180 { 181 int err = xskq_produce_batch_desc(xs->rx, (u64)xdp->handle, len); 182 183 if (err) 184 xs->rx_dropped++; 185 186 return err; 187 } 188 189 static bool xsk_is_bound(struct xdp_sock *xs) 190 { 191 if (READ_ONCE(xs->state) == XSK_BOUND) { 192 /* Matches smp_wmb() in bind(). */ 193 smp_rmb(); 194 return true; 195 } 196 return false; 197 } 198 199 int xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp) 200 { 201 u32 len; 202 203 if (!xsk_is_bound(xs)) 204 return -EINVAL; 205 206 if (xs->dev != xdp->rxq->dev || xs->queue_id != xdp->rxq->queue_index) 207 return -EINVAL; 208 209 len = xdp->data_end - xdp->data; 210 211 return (xdp->rxq->mem.type == MEM_TYPE_ZERO_COPY) ? 212 __xsk_rcv_zc(xs, xdp, len) : __xsk_rcv(xs, xdp, len); 213 } 214 215 void xsk_flush(struct xdp_sock *xs) 216 { 217 xskq_produce_flush_desc(xs->rx); 218 xs->sk.sk_data_ready(&xs->sk); 219 } 220 221 int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp) 222 { 223 u32 metalen = xdp->data - xdp->data_meta; 224 u32 len = xdp->data_end - xdp->data; 225 u64 offset = xs->umem->headroom; 226 void *buffer; 227 u64 addr; 228 int err; 229 230 spin_lock_bh(&xs->rx_lock); 231 232 if (xs->dev != xdp->rxq->dev || xs->queue_id != xdp->rxq->queue_index) { 233 err = -EINVAL; 234 goto out_unlock; 235 } 236 237 if (!xskq_peek_addr(xs->umem->fq, &addr, xs->umem) || 238 len > xs->umem->chunk_size_nohr - XDP_PACKET_HEADROOM) { 239 err = -ENOSPC; 240 goto out_drop; 241 } 242 243 addr = xsk_umem_adjust_offset(xs->umem, addr, offset); 244 buffer = xdp_umem_get_data(xs->umem, addr); 245 memcpy(buffer, xdp->data_meta, len + metalen); 246 247 addr = xsk_umem_adjust_offset(xs->umem, addr, metalen); 248 err = xskq_produce_batch_desc(xs->rx, addr, len); 249 if (err) 250 goto out_drop; 251 252 xskq_discard_addr(xs->umem->fq); 253 xskq_produce_flush_desc(xs->rx); 254 255 spin_unlock_bh(&xs->rx_lock); 256 257 xs->sk.sk_data_ready(&xs->sk); 258 return 0; 259 260 out_drop: 261 xs->rx_dropped++; 262 out_unlock: 263 spin_unlock_bh(&xs->rx_lock); 264 return err; 265 } 266 267 void xsk_umem_complete_tx(struct xdp_umem *umem, u32 nb_entries) 268 { 269 xskq_produce_flush_addr_n(umem->cq, nb_entries); 270 } 271 EXPORT_SYMBOL(xsk_umem_complete_tx); 272 273 void xsk_umem_consume_tx_done(struct xdp_umem *umem) 274 { 275 struct xdp_sock *xs; 276 277 rcu_read_lock(); 278 list_for_each_entry_rcu(xs, &umem->xsk_list, list) { 279 xs->sk.sk_write_space(&xs->sk); 280 } 281 rcu_read_unlock(); 282 } 283 EXPORT_SYMBOL(xsk_umem_consume_tx_done); 284 285 bool xsk_umem_consume_tx(struct xdp_umem *umem, struct xdp_desc *desc) 286 { 287 struct xdp_sock *xs; 288 289 rcu_read_lock(); 290 list_for_each_entry_rcu(xs, &umem->xsk_list, list) { 291 if (!xskq_peek_desc(xs->tx, desc, umem)) 292 continue; 293 294 if (xskq_produce_addr_lazy(umem->cq, desc->addr)) 295 goto out; 296 297 xskq_discard_desc(xs->tx); 298 rcu_read_unlock(); 299 return true; 300 } 301 302 out: 303 rcu_read_unlock(); 304 return false; 305 } 306 EXPORT_SYMBOL(xsk_umem_consume_tx); 307 308 static int xsk_zc_xmit(struct sock *sk) 309 { 310 struct xdp_sock *xs = xdp_sk(sk); 311 struct net_device *dev = xs->dev; 312 313 return dev->netdev_ops->ndo_xsk_wakeup(dev, xs->queue_id, 314 XDP_WAKEUP_TX); 315 } 316 317 static void xsk_destruct_skb(struct sk_buff *skb) 318 { 319 u64 addr = (u64)(long)skb_shinfo(skb)->destructor_arg; 320 struct xdp_sock *xs = xdp_sk(skb->sk); 321 unsigned long flags; 322 323 spin_lock_irqsave(&xs->tx_completion_lock, flags); 324 WARN_ON_ONCE(xskq_produce_addr(xs->umem->cq, addr)); 325 spin_unlock_irqrestore(&xs->tx_completion_lock, flags); 326 327 sock_wfree(skb); 328 } 329 330 static int xsk_generic_xmit(struct sock *sk, struct msghdr *m, 331 size_t total_len) 332 { 333 u32 max_batch = TX_BATCH_SIZE; 334 struct xdp_sock *xs = xdp_sk(sk); 335 bool sent_frame = false; 336 struct xdp_desc desc; 337 struct sk_buff *skb; 338 int err = 0; 339 340 mutex_lock(&xs->mutex); 341 342 if (xs->queue_id >= xs->dev->real_num_tx_queues) 343 goto out; 344 345 while (xskq_peek_desc(xs->tx, &desc, xs->umem)) { 346 char *buffer; 347 u64 addr; 348 u32 len; 349 350 if (max_batch-- == 0) { 351 err = -EAGAIN; 352 goto out; 353 } 354 355 len = desc.len; 356 skb = sock_alloc_send_skb(sk, len, 1, &err); 357 if (unlikely(!skb)) { 358 err = -EAGAIN; 359 goto out; 360 } 361 362 skb_put(skb, len); 363 addr = desc.addr; 364 buffer = xdp_umem_get_data(xs->umem, addr); 365 err = skb_store_bits(skb, 0, buffer, len); 366 if (unlikely(err) || xskq_reserve_addr(xs->umem->cq)) { 367 kfree_skb(skb); 368 goto out; 369 } 370 371 skb->dev = xs->dev; 372 skb->priority = sk->sk_priority; 373 skb->mark = sk->sk_mark; 374 skb_shinfo(skb)->destructor_arg = (void *)(long)desc.addr; 375 skb->destructor = xsk_destruct_skb; 376 377 err = dev_direct_xmit(skb, xs->queue_id); 378 xskq_discard_desc(xs->tx); 379 /* Ignore NET_XMIT_CN as packet might have been sent */ 380 if (err == NET_XMIT_DROP || err == NETDEV_TX_BUSY) { 381 /* SKB completed but not sent */ 382 err = -EBUSY; 383 goto out; 384 } 385 386 sent_frame = true; 387 } 388 389 out: 390 if (sent_frame) 391 sk->sk_write_space(sk); 392 393 mutex_unlock(&xs->mutex); 394 return err; 395 } 396 397 static int xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len) 398 { 399 bool need_wait = !(m->msg_flags & MSG_DONTWAIT); 400 struct sock *sk = sock->sk; 401 struct xdp_sock *xs = xdp_sk(sk); 402 403 if (unlikely(!xsk_is_bound(xs))) 404 return -ENXIO; 405 if (unlikely(!(xs->dev->flags & IFF_UP))) 406 return -ENETDOWN; 407 if (unlikely(!xs->tx)) 408 return -ENOBUFS; 409 if (need_wait) 410 return -EOPNOTSUPP; 411 412 return (xs->zc) ? xsk_zc_xmit(sk) : xsk_generic_xmit(sk, m, total_len); 413 } 414 415 static unsigned int xsk_poll(struct file *file, struct socket *sock, 416 struct poll_table_struct *wait) 417 { 418 unsigned int mask = datagram_poll(file, sock, wait); 419 struct xdp_sock *xs = xdp_sk(sock->sk); 420 struct net_device *dev; 421 struct xdp_umem *umem; 422 423 if (unlikely(!xsk_is_bound(xs))) 424 return mask; 425 426 dev = xs->dev; 427 umem = xs->umem; 428 429 if (umem->need_wakeup) 430 dev->netdev_ops->ndo_xsk_wakeup(dev, xs->queue_id, 431 umem->need_wakeup); 432 433 if (xs->rx && !xskq_empty_desc(xs->rx)) 434 mask |= POLLIN | POLLRDNORM; 435 if (xs->tx && !xskq_full_desc(xs->tx)) 436 mask |= POLLOUT | POLLWRNORM; 437 438 return mask; 439 } 440 441 static int xsk_init_queue(u32 entries, struct xsk_queue **queue, 442 bool umem_queue) 443 { 444 struct xsk_queue *q; 445 446 if (entries == 0 || *queue || !is_power_of_2(entries)) 447 return -EINVAL; 448 449 q = xskq_create(entries, umem_queue); 450 if (!q) 451 return -ENOMEM; 452 453 /* Make sure queue is ready before it can be seen by others */ 454 smp_wmb(); 455 WRITE_ONCE(*queue, q); 456 return 0; 457 } 458 459 static void xsk_unbind_dev(struct xdp_sock *xs) 460 { 461 struct net_device *dev = xs->dev; 462 463 if (xs->state != XSK_BOUND) 464 return; 465 WRITE_ONCE(xs->state, XSK_UNBOUND); 466 467 /* Wait for driver to stop using the xdp socket. */ 468 xdp_del_sk_umem(xs->umem, xs); 469 xs->dev = NULL; 470 synchronize_net(); 471 dev_put(dev); 472 } 473 474 static struct xsk_map *xsk_get_map_list_entry(struct xdp_sock *xs, 475 struct xdp_sock ***map_entry) 476 { 477 struct xsk_map *map = NULL; 478 struct xsk_map_node *node; 479 480 *map_entry = NULL; 481 482 spin_lock_bh(&xs->map_list_lock); 483 node = list_first_entry_or_null(&xs->map_list, struct xsk_map_node, 484 node); 485 if (node) { 486 WARN_ON(xsk_map_inc(node->map)); 487 map = node->map; 488 *map_entry = node->map_entry; 489 } 490 spin_unlock_bh(&xs->map_list_lock); 491 return map; 492 } 493 494 static void xsk_delete_from_maps(struct xdp_sock *xs) 495 { 496 /* This function removes the current XDP socket from all the 497 * maps it resides in. We need to take extra care here, due to 498 * the two locks involved. Each map has a lock synchronizing 499 * updates to the entries, and each socket has a lock that 500 * synchronizes access to the list of maps (map_list). For 501 * deadlock avoidance the locks need to be taken in the order 502 * "map lock"->"socket map list lock". We start off by 503 * accessing the socket map list, and take a reference to the 504 * map to guarantee existence between the 505 * xsk_get_map_list_entry() and xsk_map_try_sock_delete() 506 * calls. Then we ask the map to remove the socket, which 507 * tries to remove the socket from the map. Note that there 508 * might be updates to the map between 509 * xsk_get_map_list_entry() and xsk_map_try_sock_delete(). 510 */ 511 struct xdp_sock **map_entry = NULL; 512 struct xsk_map *map; 513 514 while ((map = xsk_get_map_list_entry(xs, &map_entry))) { 515 xsk_map_try_sock_delete(map, xs, map_entry); 516 xsk_map_put(map); 517 } 518 } 519 520 static int xsk_release(struct socket *sock) 521 { 522 struct sock *sk = sock->sk; 523 struct xdp_sock *xs = xdp_sk(sk); 524 struct net *net; 525 526 if (!sk) 527 return 0; 528 529 net = sock_net(sk); 530 531 mutex_lock(&net->xdp.lock); 532 sk_del_node_init_rcu(sk); 533 mutex_unlock(&net->xdp.lock); 534 535 local_bh_disable(); 536 sock_prot_inuse_add(net, sk->sk_prot, -1); 537 local_bh_enable(); 538 539 xsk_delete_from_maps(xs); 540 mutex_lock(&xs->mutex); 541 xsk_unbind_dev(xs); 542 mutex_unlock(&xs->mutex); 543 544 xskq_destroy(xs->rx); 545 xskq_destroy(xs->tx); 546 547 sock_orphan(sk); 548 sock->sk = NULL; 549 550 sk_refcnt_debug_release(sk); 551 sock_put(sk); 552 553 return 0; 554 } 555 556 static struct socket *xsk_lookup_xsk_from_fd(int fd) 557 { 558 struct socket *sock; 559 int err; 560 561 sock = sockfd_lookup(fd, &err); 562 if (!sock) 563 return ERR_PTR(-ENOTSOCK); 564 565 if (sock->sk->sk_family != PF_XDP) { 566 sockfd_put(sock); 567 return ERR_PTR(-ENOPROTOOPT); 568 } 569 570 return sock; 571 } 572 573 /* Check if umem pages are contiguous. 574 * If zero-copy mode, use the DMA address to do the page contiguity check 575 * For all other modes we use addr (kernel virtual address) 576 * Store the result in the low bits of addr. 577 */ 578 static void xsk_check_page_contiguity(struct xdp_umem *umem, u32 flags) 579 { 580 struct xdp_umem_page *pgs = umem->pages; 581 int i, is_contig; 582 583 for (i = 0; i < umem->npgs - 1; i++) { 584 is_contig = (flags & XDP_ZEROCOPY) ? 585 (pgs[i].dma + PAGE_SIZE == pgs[i + 1].dma) : 586 (pgs[i].addr + PAGE_SIZE == pgs[i + 1].addr); 587 pgs[i].addr += is_contig << XSK_NEXT_PG_CONTIG_SHIFT; 588 } 589 } 590 591 static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len) 592 { 593 struct sockaddr_xdp *sxdp = (struct sockaddr_xdp *)addr; 594 struct sock *sk = sock->sk; 595 struct xdp_sock *xs = xdp_sk(sk); 596 struct net_device *dev; 597 u32 flags, qid; 598 int err = 0; 599 600 if (addr_len < sizeof(struct sockaddr_xdp)) 601 return -EINVAL; 602 if (sxdp->sxdp_family != AF_XDP) 603 return -EINVAL; 604 605 flags = sxdp->sxdp_flags; 606 if (flags & ~(XDP_SHARED_UMEM | XDP_COPY | XDP_ZEROCOPY | 607 XDP_USE_NEED_WAKEUP)) 608 return -EINVAL; 609 610 rtnl_lock(); 611 mutex_lock(&xs->mutex); 612 if (xs->state != XSK_READY) { 613 err = -EBUSY; 614 goto out_release; 615 } 616 617 dev = dev_get_by_index(sock_net(sk), sxdp->sxdp_ifindex); 618 if (!dev) { 619 err = -ENODEV; 620 goto out_release; 621 } 622 623 if (!xs->rx && !xs->tx) { 624 err = -EINVAL; 625 goto out_unlock; 626 } 627 628 qid = sxdp->sxdp_queue_id; 629 630 if (flags & XDP_SHARED_UMEM) { 631 struct xdp_sock *umem_xs; 632 struct socket *sock; 633 634 if ((flags & XDP_COPY) || (flags & XDP_ZEROCOPY) || 635 (flags & XDP_USE_NEED_WAKEUP)) { 636 /* Cannot specify flags for shared sockets. */ 637 err = -EINVAL; 638 goto out_unlock; 639 } 640 641 if (xs->umem) { 642 /* We have already our own. */ 643 err = -EINVAL; 644 goto out_unlock; 645 } 646 647 sock = xsk_lookup_xsk_from_fd(sxdp->sxdp_shared_umem_fd); 648 if (IS_ERR(sock)) { 649 err = PTR_ERR(sock); 650 goto out_unlock; 651 } 652 653 umem_xs = xdp_sk(sock->sk); 654 if (!xsk_is_bound(umem_xs)) { 655 err = -EBADF; 656 sockfd_put(sock); 657 goto out_unlock; 658 } 659 if (umem_xs->dev != dev || umem_xs->queue_id != qid) { 660 err = -EINVAL; 661 sockfd_put(sock); 662 goto out_unlock; 663 } 664 665 xdp_get_umem(umem_xs->umem); 666 WRITE_ONCE(xs->umem, umem_xs->umem); 667 sockfd_put(sock); 668 } else if (!xs->umem || !xdp_umem_validate_queues(xs->umem)) { 669 err = -EINVAL; 670 goto out_unlock; 671 } else { 672 /* This xsk has its own umem. */ 673 xskq_set_umem(xs->umem->fq, xs->umem->size, 674 xs->umem->chunk_mask); 675 xskq_set_umem(xs->umem->cq, xs->umem->size, 676 xs->umem->chunk_mask); 677 678 err = xdp_umem_assign_dev(xs->umem, dev, qid, flags); 679 if (err) 680 goto out_unlock; 681 682 xsk_check_page_contiguity(xs->umem, flags); 683 } 684 685 xs->dev = dev; 686 xs->zc = xs->umem->zc; 687 xs->queue_id = qid; 688 xskq_set_umem(xs->rx, xs->umem->size, xs->umem->chunk_mask); 689 xskq_set_umem(xs->tx, xs->umem->size, xs->umem->chunk_mask); 690 xdp_add_sk_umem(xs->umem, xs); 691 692 out_unlock: 693 if (err) { 694 dev_put(dev); 695 } else { 696 /* Matches smp_rmb() in bind() for shared umem 697 * sockets, and xsk_is_bound(). 698 */ 699 smp_wmb(); 700 WRITE_ONCE(xs->state, XSK_BOUND); 701 } 702 out_release: 703 mutex_unlock(&xs->mutex); 704 rtnl_unlock(); 705 return err; 706 } 707 708 struct xdp_umem_reg_v1 { 709 __u64 addr; /* Start of packet data area */ 710 __u64 len; /* Length of packet data area */ 711 __u32 chunk_size; 712 __u32 headroom; 713 }; 714 715 static int xsk_setsockopt(struct socket *sock, int level, int optname, 716 char __user *optval, unsigned int optlen) 717 { 718 struct sock *sk = sock->sk; 719 struct xdp_sock *xs = xdp_sk(sk); 720 int err; 721 722 if (level != SOL_XDP) 723 return -ENOPROTOOPT; 724 725 switch (optname) { 726 case XDP_RX_RING: 727 case XDP_TX_RING: 728 { 729 struct xsk_queue **q; 730 int entries; 731 732 if (optlen < sizeof(entries)) 733 return -EINVAL; 734 if (copy_from_user(&entries, optval, sizeof(entries))) 735 return -EFAULT; 736 737 mutex_lock(&xs->mutex); 738 if (xs->state != XSK_READY) { 739 mutex_unlock(&xs->mutex); 740 return -EBUSY; 741 } 742 q = (optname == XDP_TX_RING) ? &xs->tx : &xs->rx; 743 err = xsk_init_queue(entries, q, false); 744 if (!err && optname == XDP_TX_RING) 745 /* Tx needs to be explicitly woken up the first time */ 746 xs->tx->ring->flags |= XDP_RING_NEED_WAKEUP; 747 mutex_unlock(&xs->mutex); 748 return err; 749 } 750 case XDP_UMEM_REG: 751 { 752 size_t mr_size = sizeof(struct xdp_umem_reg); 753 struct xdp_umem_reg mr = {}; 754 struct xdp_umem *umem; 755 756 if (optlen < sizeof(struct xdp_umem_reg_v1)) 757 return -EINVAL; 758 else if (optlen < sizeof(mr)) 759 mr_size = sizeof(struct xdp_umem_reg_v1); 760 761 if (copy_from_user(&mr, optval, mr_size)) 762 return -EFAULT; 763 764 mutex_lock(&xs->mutex); 765 if (xs->state != XSK_READY || xs->umem) { 766 mutex_unlock(&xs->mutex); 767 return -EBUSY; 768 } 769 770 umem = xdp_umem_create(&mr); 771 if (IS_ERR(umem)) { 772 mutex_unlock(&xs->mutex); 773 return PTR_ERR(umem); 774 } 775 776 /* Make sure umem is ready before it can be seen by others */ 777 smp_wmb(); 778 WRITE_ONCE(xs->umem, umem); 779 mutex_unlock(&xs->mutex); 780 return 0; 781 } 782 case XDP_UMEM_FILL_RING: 783 case XDP_UMEM_COMPLETION_RING: 784 { 785 struct xsk_queue **q; 786 int entries; 787 788 if (copy_from_user(&entries, optval, sizeof(entries))) 789 return -EFAULT; 790 791 mutex_lock(&xs->mutex); 792 if (xs->state != XSK_READY) { 793 mutex_unlock(&xs->mutex); 794 return -EBUSY; 795 } 796 if (!xs->umem) { 797 mutex_unlock(&xs->mutex); 798 return -EINVAL; 799 } 800 801 q = (optname == XDP_UMEM_FILL_RING) ? &xs->umem->fq : 802 &xs->umem->cq; 803 err = xsk_init_queue(entries, q, true); 804 mutex_unlock(&xs->mutex); 805 return err; 806 } 807 default: 808 break; 809 } 810 811 return -ENOPROTOOPT; 812 } 813 814 static void xsk_enter_rxtx_offsets(struct xdp_ring_offset_v1 *ring) 815 { 816 ring->producer = offsetof(struct xdp_rxtx_ring, ptrs.producer); 817 ring->consumer = offsetof(struct xdp_rxtx_ring, ptrs.consumer); 818 ring->desc = offsetof(struct xdp_rxtx_ring, desc); 819 } 820 821 static void xsk_enter_umem_offsets(struct xdp_ring_offset_v1 *ring) 822 { 823 ring->producer = offsetof(struct xdp_umem_ring, ptrs.producer); 824 ring->consumer = offsetof(struct xdp_umem_ring, ptrs.consumer); 825 ring->desc = offsetof(struct xdp_umem_ring, desc); 826 } 827 828 static int xsk_getsockopt(struct socket *sock, int level, int optname, 829 char __user *optval, int __user *optlen) 830 { 831 struct sock *sk = sock->sk; 832 struct xdp_sock *xs = xdp_sk(sk); 833 int len; 834 835 if (level != SOL_XDP) 836 return -ENOPROTOOPT; 837 838 if (get_user(len, optlen)) 839 return -EFAULT; 840 if (len < 0) 841 return -EINVAL; 842 843 switch (optname) { 844 case XDP_STATISTICS: 845 { 846 struct xdp_statistics stats; 847 848 if (len < sizeof(stats)) 849 return -EINVAL; 850 851 mutex_lock(&xs->mutex); 852 stats.rx_dropped = xs->rx_dropped; 853 stats.rx_invalid_descs = xskq_nb_invalid_descs(xs->rx); 854 stats.tx_invalid_descs = xskq_nb_invalid_descs(xs->tx); 855 mutex_unlock(&xs->mutex); 856 857 if (copy_to_user(optval, &stats, sizeof(stats))) 858 return -EFAULT; 859 if (put_user(sizeof(stats), optlen)) 860 return -EFAULT; 861 862 return 0; 863 } 864 case XDP_MMAP_OFFSETS: 865 { 866 struct xdp_mmap_offsets off; 867 struct xdp_mmap_offsets_v1 off_v1; 868 bool flags_supported = true; 869 void *to_copy; 870 871 if (len < sizeof(off_v1)) 872 return -EINVAL; 873 else if (len < sizeof(off)) 874 flags_supported = false; 875 876 if (flags_supported) { 877 /* xdp_ring_offset is identical to xdp_ring_offset_v1 878 * except for the flags field added to the end. 879 */ 880 xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *) 881 &off.rx); 882 xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *) 883 &off.tx); 884 xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *) 885 &off.fr); 886 xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *) 887 &off.cr); 888 off.rx.flags = offsetof(struct xdp_rxtx_ring, 889 ptrs.flags); 890 off.tx.flags = offsetof(struct xdp_rxtx_ring, 891 ptrs.flags); 892 off.fr.flags = offsetof(struct xdp_umem_ring, 893 ptrs.flags); 894 off.cr.flags = offsetof(struct xdp_umem_ring, 895 ptrs.flags); 896 897 len = sizeof(off); 898 to_copy = &off; 899 } else { 900 xsk_enter_rxtx_offsets(&off_v1.rx); 901 xsk_enter_rxtx_offsets(&off_v1.tx); 902 xsk_enter_umem_offsets(&off_v1.fr); 903 xsk_enter_umem_offsets(&off_v1.cr); 904 905 len = sizeof(off_v1); 906 to_copy = &off_v1; 907 } 908 909 if (copy_to_user(optval, to_copy, len)) 910 return -EFAULT; 911 if (put_user(len, optlen)) 912 return -EFAULT; 913 914 return 0; 915 } 916 case XDP_OPTIONS: 917 { 918 struct xdp_options opts = {}; 919 920 if (len < sizeof(opts)) 921 return -EINVAL; 922 923 mutex_lock(&xs->mutex); 924 if (xs->zc) 925 opts.flags |= XDP_OPTIONS_ZEROCOPY; 926 mutex_unlock(&xs->mutex); 927 928 len = sizeof(opts); 929 if (copy_to_user(optval, &opts, len)) 930 return -EFAULT; 931 if (put_user(len, optlen)) 932 return -EFAULT; 933 934 return 0; 935 } 936 default: 937 break; 938 } 939 940 return -EOPNOTSUPP; 941 } 942 943 static int xsk_mmap(struct file *file, struct socket *sock, 944 struct vm_area_struct *vma) 945 { 946 loff_t offset = (loff_t)vma->vm_pgoff << PAGE_SHIFT; 947 unsigned long size = vma->vm_end - vma->vm_start; 948 struct xdp_sock *xs = xdp_sk(sock->sk); 949 struct xsk_queue *q = NULL; 950 struct xdp_umem *umem; 951 unsigned long pfn; 952 struct page *qpg; 953 954 if (READ_ONCE(xs->state) != XSK_READY) 955 return -EBUSY; 956 957 if (offset == XDP_PGOFF_RX_RING) { 958 q = READ_ONCE(xs->rx); 959 } else if (offset == XDP_PGOFF_TX_RING) { 960 q = READ_ONCE(xs->tx); 961 } else { 962 umem = READ_ONCE(xs->umem); 963 if (!umem) 964 return -EINVAL; 965 966 /* Matches the smp_wmb() in XDP_UMEM_REG */ 967 smp_rmb(); 968 if (offset == XDP_UMEM_PGOFF_FILL_RING) 969 q = READ_ONCE(umem->fq); 970 else if (offset == XDP_UMEM_PGOFF_COMPLETION_RING) 971 q = READ_ONCE(umem->cq); 972 } 973 974 if (!q) 975 return -EINVAL; 976 977 /* Matches the smp_wmb() in xsk_init_queue */ 978 smp_rmb(); 979 qpg = virt_to_head_page(q->ring); 980 if (size > page_size(qpg)) 981 return -EINVAL; 982 983 pfn = virt_to_phys(q->ring) >> PAGE_SHIFT; 984 return remap_pfn_range(vma, vma->vm_start, pfn, 985 size, vma->vm_page_prot); 986 } 987 988 static int xsk_notifier(struct notifier_block *this, 989 unsigned long msg, void *ptr) 990 { 991 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 992 struct net *net = dev_net(dev); 993 struct sock *sk; 994 995 switch (msg) { 996 case NETDEV_UNREGISTER: 997 mutex_lock(&net->xdp.lock); 998 sk_for_each(sk, &net->xdp.list) { 999 struct xdp_sock *xs = xdp_sk(sk); 1000 1001 mutex_lock(&xs->mutex); 1002 if (xs->dev == dev) { 1003 sk->sk_err = ENETDOWN; 1004 if (!sock_flag(sk, SOCK_DEAD)) 1005 sk->sk_error_report(sk); 1006 1007 xsk_unbind_dev(xs); 1008 1009 /* Clear device references in umem. */ 1010 xdp_umem_clear_dev(xs->umem); 1011 } 1012 mutex_unlock(&xs->mutex); 1013 } 1014 mutex_unlock(&net->xdp.lock); 1015 break; 1016 } 1017 return NOTIFY_DONE; 1018 } 1019 1020 static struct proto xsk_proto = { 1021 .name = "XDP", 1022 .owner = THIS_MODULE, 1023 .obj_size = sizeof(struct xdp_sock), 1024 }; 1025 1026 static const struct proto_ops xsk_proto_ops = { 1027 .family = PF_XDP, 1028 .owner = THIS_MODULE, 1029 .release = xsk_release, 1030 .bind = xsk_bind, 1031 .connect = sock_no_connect, 1032 .socketpair = sock_no_socketpair, 1033 .accept = sock_no_accept, 1034 .getname = sock_no_getname, 1035 .poll = xsk_poll, 1036 .ioctl = sock_no_ioctl, 1037 .listen = sock_no_listen, 1038 .shutdown = sock_no_shutdown, 1039 .setsockopt = xsk_setsockopt, 1040 .getsockopt = xsk_getsockopt, 1041 .sendmsg = xsk_sendmsg, 1042 .recvmsg = sock_no_recvmsg, 1043 .mmap = xsk_mmap, 1044 .sendpage = sock_no_sendpage, 1045 }; 1046 1047 static void xsk_destruct(struct sock *sk) 1048 { 1049 struct xdp_sock *xs = xdp_sk(sk); 1050 1051 if (!sock_flag(sk, SOCK_DEAD)) 1052 return; 1053 1054 xdp_put_umem(xs->umem); 1055 1056 sk_refcnt_debug_dec(sk); 1057 } 1058 1059 static int xsk_create(struct net *net, struct socket *sock, int protocol, 1060 int kern) 1061 { 1062 struct sock *sk; 1063 struct xdp_sock *xs; 1064 1065 if (!ns_capable(net->user_ns, CAP_NET_RAW)) 1066 return -EPERM; 1067 if (sock->type != SOCK_RAW) 1068 return -ESOCKTNOSUPPORT; 1069 1070 if (protocol) 1071 return -EPROTONOSUPPORT; 1072 1073 sock->state = SS_UNCONNECTED; 1074 1075 sk = sk_alloc(net, PF_XDP, GFP_KERNEL, &xsk_proto, kern); 1076 if (!sk) 1077 return -ENOBUFS; 1078 1079 sock->ops = &xsk_proto_ops; 1080 1081 sock_init_data(sock, sk); 1082 1083 sk->sk_family = PF_XDP; 1084 1085 sk->sk_destruct = xsk_destruct; 1086 sk_refcnt_debug_inc(sk); 1087 1088 sock_set_flag(sk, SOCK_RCU_FREE); 1089 1090 xs = xdp_sk(sk); 1091 xs->state = XSK_READY; 1092 mutex_init(&xs->mutex); 1093 spin_lock_init(&xs->rx_lock); 1094 spin_lock_init(&xs->tx_completion_lock); 1095 1096 INIT_LIST_HEAD(&xs->map_list); 1097 spin_lock_init(&xs->map_list_lock); 1098 1099 mutex_lock(&net->xdp.lock); 1100 sk_add_node_rcu(sk, &net->xdp.list); 1101 mutex_unlock(&net->xdp.lock); 1102 1103 local_bh_disable(); 1104 sock_prot_inuse_add(net, &xsk_proto, 1); 1105 local_bh_enable(); 1106 1107 return 0; 1108 } 1109 1110 static const struct net_proto_family xsk_family_ops = { 1111 .family = PF_XDP, 1112 .create = xsk_create, 1113 .owner = THIS_MODULE, 1114 }; 1115 1116 static struct notifier_block xsk_netdev_notifier = { 1117 .notifier_call = xsk_notifier, 1118 }; 1119 1120 static int __net_init xsk_net_init(struct net *net) 1121 { 1122 mutex_init(&net->xdp.lock); 1123 INIT_HLIST_HEAD(&net->xdp.list); 1124 return 0; 1125 } 1126 1127 static void __net_exit xsk_net_exit(struct net *net) 1128 { 1129 WARN_ON_ONCE(!hlist_empty(&net->xdp.list)); 1130 } 1131 1132 static struct pernet_operations xsk_net_ops = { 1133 .init = xsk_net_init, 1134 .exit = xsk_net_exit, 1135 }; 1136 1137 static int __init xsk_init(void) 1138 { 1139 int err; 1140 1141 err = proto_register(&xsk_proto, 0 /* no slab */); 1142 if (err) 1143 goto out; 1144 1145 err = sock_register(&xsk_family_ops); 1146 if (err) 1147 goto out_proto; 1148 1149 err = register_pernet_subsys(&xsk_net_ops); 1150 if (err) 1151 goto out_sk; 1152 1153 err = register_netdevice_notifier(&xsk_netdev_notifier); 1154 if (err) 1155 goto out_pernet; 1156 1157 return 0; 1158 1159 out_pernet: 1160 unregister_pernet_subsys(&xsk_net_ops); 1161 out_sk: 1162 sock_unregister(PF_XDP); 1163 out_proto: 1164 proto_unregister(&xsk_proto); 1165 out: 1166 return err; 1167 } 1168 1169 fs_initcall(xsk_init); 1170