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 <linux/vmalloc.h> 26 #include <net/xdp_sock_drv.h> 27 #include <net/busy_poll.h> 28 #include <net/netdev_rx_queue.h> 29 #include <net/xdp.h> 30 31 #include "xsk_queue.h" 32 #include "xdp_umem.h" 33 #include "xsk.h" 34 35 #define TX_BATCH_SIZE 32 36 #define MAX_PER_SOCKET_BUDGET (TX_BATCH_SIZE) 37 38 static DEFINE_PER_CPU(struct list_head, xskmap_flush_list); 39 40 void xsk_set_rx_need_wakeup(struct xsk_buff_pool *pool) 41 { 42 if (pool->cached_need_wakeup & XDP_WAKEUP_RX) 43 return; 44 45 pool->fq->ring->flags |= XDP_RING_NEED_WAKEUP; 46 pool->cached_need_wakeup |= XDP_WAKEUP_RX; 47 } 48 EXPORT_SYMBOL(xsk_set_rx_need_wakeup); 49 50 void xsk_set_tx_need_wakeup(struct xsk_buff_pool *pool) 51 { 52 struct xdp_sock *xs; 53 54 if (pool->cached_need_wakeup & XDP_WAKEUP_TX) 55 return; 56 57 rcu_read_lock(); 58 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) { 59 xs->tx->ring->flags |= XDP_RING_NEED_WAKEUP; 60 } 61 rcu_read_unlock(); 62 63 pool->cached_need_wakeup |= XDP_WAKEUP_TX; 64 } 65 EXPORT_SYMBOL(xsk_set_tx_need_wakeup); 66 67 void xsk_clear_rx_need_wakeup(struct xsk_buff_pool *pool) 68 { 69 if (!(pool->cached_need_wakeup & XDP_WAKEUP_RX)) 70 return; 71 72 pool->fq->ring->flags &= ~XDP_RING_NEED_WAKEUP; 73 pool->cached_need_wakeup &= ~XDP_WAKEUP_RX; 74 } 75 EXPORT_SYMBOL(xsk_clear_rx_need_wakeup); 76 77 void xsk_clear_tx_need_wakeup(struct xsk_buff_pool *pool) 78 { 79 struct xdp_sock *xs; 80 81 if (!(pool->cached_need_wakeup & XDP_WAKEUP_TX)) 82 return; 83 84 rcu_read_lock(); 85 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) { 86 xs->tx->ring->flags &= ~XDP_RING_NEED_WAKEUP; 87 } 88 rcu_read_unlock(); 89 90 pool->cached_need_wakeup &= ~XDP_WAKEUP_TX; 91 } 92 EXPORT_SYMBOL(xsk_clear_tx_need_wakeup); 93 94 bool xsk_uses_need_wakeup(struct xsk_buff_pool *pool) 95 { 96 return pool->uses_need_wakeup; 97 } 98 EXPORT_SYMBOL(xsk_uses_need_wakeup); 99 100 struct xsk_buff_pool *xsk_get_pool_from_qid(struct net_device *dev, 101 u16 queue_id) 102 { 103 if (queue_id < dev->real_num_rx_queues) 104 return dev->_rx[queue_id].pool; 105 if (queue_id < dev->real_num_tx_queues) 106 return dev->_tx[queue_id].pool; 107 108 return NULL; 109 } 110 EXPORT_SYMBOL(xsk_get_pool_from_qid); 111 112 void xsk_clear_pool_at_qid(struct net_device *dev, u16 queue_id) 113 { 114 if (queue_id < dev->num_rx_queues) 115 dev->_rx[queue_id].pool = NULL; 116 if (queue_id < dev->num_tx_queues) 117 dev->_tx[queue_id].pool = NULL; 118 } 119 120 /* The buffer pool is stored both in the _rx struct and the _tx struct as we do 121 * not know if the device has more tx queues than rx, or the opposite. 122 * This might also change during run time. 123 */ 124 int xsk_reg_pool_at_qid(struct net_device *dev, struct xsk_buff_pool *pool, 125 u16 queue_id) 126 { 127 if (queue_id >= max_t(unsigned int, 128 dev->real_num_rx_queues, 129 dev->real_num_tx_queues)) 130 return -EINVAL; 131 132 if (queue_id < dev->real_num_rx_queues) 133 dev->_rx[queue_id].pool = pool; 134 if (queue_id < dev->real_num_tx_queues) 135 dev->_tx[queue_id].pool = pool; 136 137 return 0; 138 } 139 140 static int __xsk_rcv_zc(struct xdp_sock *xs, struct xdp_buff_xsk *xskb, u32 len, 141 u32 flags) 142 { 143 u64 addr; 144 int err; 145 146 addr = xp_get_handle(xskb); 147 err = xskq_prod_reserve_desc(xs->rx, addr, len, flags); 148 if (err) { 149 xs->rx_queue_full++; 150 return err; 151 } 152 153 xp_release(xskb); 154 return 0; 155 } 156 157 static int xsk_rcv_zc(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len) 158 { 159 struct xdp_buff_xsk *xskb = container_of(xdp, struct xdp_buff_xsk, xdp); 160 u32 frags = xdp_buff_has_frags(xdp); 161 struct xdp_buff_xsk *pos, *tmp; 162 struct list_head *xskb_list; 163 u32 contd = 0; 164 int err; 165 166 if (frags) 167 contd = XDP_PKT_CONTD; 168 169 err = __xsk_rcv_zc(xs, xskb, len, contd); 170 if (err || likely(!frags)) 171 goto out; 172 173 xskb_list = &xskb->pool->xskb_list; 174 list_for_each_entry_safe(pos, tmp, xskb_list, xskb_list_node) { 175 if (list_is_singular(xskb_list)) 176 contd = 0; 177 len = pos->xdp.data_end - pos->xdp.data; 178 err = __xsk_rcv_zc(xs, pos, len, contd); 179 if (err) 180 return err; 181 list_del(&pos->xskb_list_node); 182 } 183 184 out: 185 return err; 186 } 187 188 static void *xsk_copy_xdp_start(struct xdp_buff *from) 189 { 190 if (unlikely(xdp_data_meta_unsupported(from))) 191 return from->data; 192 else 193 return from->data_meta; 194 } 195 196 static u32 xsk_copy_xdp(void *to, void **from, u32 to_len, 197 u32 *from_len, skb_frag_t **frag, u32 rem) 198 { 199 u32 copied = 0; 200 201 while (1) { 202 u32 copy_len = min_t(u32, *from_len, to_len); 203 204 memcpy(to, *from, copy_len); 205 copied += copy_len; 206 if (rem == copied) 207 return copied; 208 209 if (*from_len == copy_len) { 210 *from = skb_frag_address(*frag); 211 *from_len = skb_frag_size((*frag)++); 212 } else { 213 *from += copy_len; 214 *from_len -= copy_len; 215 } 216 if (to_len == copy_len) 217 return copied; 218 219 to_len -= copy_len; 220 to += copy_len; 221 } 222 } 223 224 static int __xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len) 225 { 226 u32 frame_size = xsk_pool_get_rx_frame_size(xs->pool); 227 void *copy_from = xsk_copy_xdp_start(xdp), *copy_to; 228 u32 from_len, meta_len, rem, num_desc; 229 struct xdp_buff_xsk *xskb; 230 struct xdp_buff *xsk_xdp; 231 skb_frag_t *frag; 232 233 from_len = xdp->data_end - copy_from; 234 meta_len = xdp->data - copy_from; 235 rem = len + meta_len; 236 237 if (len <= frame_size && !xdp_buff_has_frags(xdp)) { 238 int err; 239 240 xsk_xdp = xsk_buff_alloc(xs->pool); 241 if (!xsk_xdp) { 242 xs->rx_dropped++; 243 return -ENOMEM; 244 } 245 memcpy(xsk_xdp->data - meta_len, copy_from, rem); 246 xskb = container_of(xsk_xdp, struct xdp_buff_xsk, xdp); 247 err = __xsk_rcv_zc(xs, xskb, len, 0); 248 if (err) { 249 xsk_buff_free(xsk_xdp); 250 return err; 251 } 252 253 return 0; 254 } 255 256 num_desc = (len - 1) / frame_size + 1; 257 258 if (!xsk_buff_can_alloc(xs->pool, num_desc)) { 259 xs->rx_dropped++; 260 return -ENOMEM; 261 } 262 if (xskq_prod_nb_free(xs->rx, num_desc) < num_desc) { 263 xs->rx_queue_full++; 264 return -ENOBUFS; 265 } 266 267 if (xdp_buff_has_frags(xdp)) { 268 struct skb_shared_info *sinfo; 269 270 sinfo = xdp_get_shared_info_from_buff(xdp); 271 frag = &sinfo->frags[0]; 272 } 273 274 do { 275 u32 to_len = frame_size + meta_len; 276 u32 copied; 277 278 xsk_xdp = xsk_buff_alloc(xs->pool); 279 copy_to = xsk_xdp->data - meta_len; 280 281 copied = xsk_copy_xdp(copy_to, ©_from, to_len, &from_len, &frag, rem); 282 rem -= copied; 283 284 xskb = container_of(xsk_xdp, struct xdp_buff_xsk, xdp); 285 __xsk_rcv_zc(xs, xskb, copied - meta_len, rem ? XDP_PKT_CONTD : 0); 286 meta_len = 0; 287 } while (rem); 288 289 return 0; 290 } 291 292 static bool xsk_tx_writeable(struct xdp_sock *xs) 293 { 294 if (xskq_cons_present_entries(xs->tx) > xs->tx->nentries / 2) 295 return false; 296 297 return true; 298 } 299 300 static bool xsk_is_bound(struct xdp_sock *xs) 301 { 302 if (READ_ONCE(xs->state) == XSK_BOUND) { 303 /* Matches smp_wmb() in bind(). */ 304 smp_rmb(); 305 return true; 306 } 307 return false; 308 } 309 310 static int xsk_rcv_check(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len) 311 { 312 if (!xsk_is_bound(xs)) 313 return -ENXIO; 314 315 if (xs->dev != xdp->rxq->dev || xs->queue_id != xdp->rxq->queue_index) 316 return -EINVAL; 317 318 if (len > xsk_pool_get_rx_frame_size(xs->pool) && !xs->sg) { 319 xs->rx_dropped++; 320 return -ENOSPC; 321 } 322 323 sk_mark_napi_id_once_xdp(&xs->sk, xdp); 324 return 0; 325 } 326 327 static void xsk_flush(struct xdp_sock *xs) 328 { 329 xskq_prod_submit(xs->rx); 330 __xskq_cons_release(xs->pool->fq); 331 sock_def_readable(&xs->sk); 332 } 333 334 int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp) 335 { 336 u32 len = xdp_get_buff_len(xdp); 337 int err; 338 339 spin_lock_bh(&xs->rx_lock); 340 err = xsk_rcv_check(xs, xdp, len); 341 if (!err) { 342 err = __xsk_rcv(xs, xdp, len); 343 xsk_flush(xs); 344 } 345 spin_unlock_bh(&xs->rx_lock); 346 return err; 347 } 348 349 static int xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp) 350 { 351 u32 len = xdp_get_buff_len(xdp); 352 int err; 353 354 err = xsk_rcv_check(xs, xdp, len); 355 if (err) 356 return err; 357 358 if (xdp->rxq->mem.type == MEM_TYPE_XSK_BUFF_POOL) { 359 len = xdp->data_end - xdp->data; 360 return xsk_rcv_zc(xs, xdp, len); 361 } 362 363 err = __xsk_rcv(xs, xdp, len); 364 if (!err) 365 xdp_return_buff(xdp); 366 return err; 367 } 368 369 int __xsk_map_redirect(struct xdp_sock *xs, struct xdp_buff *xdp) 370 { 371 struct list_head *flush_list = this_cpu_ptr(&xskmap_flush_list); 372 int err; 373 374 err = xsk_rcv(xs, xdp); 375 if (err) 376 return err; 377 378 if (!xs->flush_node.prev) 379 list_add(&xs->flush_node, flush_list); 380 381 return 0; 382 } 383 384 void __xsk_map_flush(void) 385 { 386 struct list_head *flush_list = this_cpu_ptr(&xskmap_flush_list); 387 struct xdp_sock *xs, *tmp; 388 389 list_for_each_entry_safe(xs, tmp, flush_list, flush_node) { 390 xsk_flush(xs); 391 __list_del_clearprev(&xs->flush_node); 392 } 393 } 394 395 #ifdef CONFIG_DEBUG_NET 396 bool xsk_map_check_flush(void) 397 { 398 if (list_empty(this_cpu_ptr(&xskmap_flush_list))) 399 return false; 400 __xsk_map_flush(); 401 return true; 402 } 403 #endif 404 405 void xsk_tx_completed(struct xsk_buff_pool *pool, u32 nb_entries) 406 { 407 xskq_prod_submit_n(pool->cq, nb_entries); 408 } 409 EXPORT_SYMBOL(xsk_tx_completed); 410 411 void xsk_tx_release(struct xsk_buff_pool *pool) 412 { 413 struct xdp_sock *xs; 414 415 rcu_read_lock(); 416 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) { 417 __xskq_cons_release(xs->tx); 418 if (xsk_tx_writeable(xs)) 419 xs->sk.sk_write_space(&xs->sk); 420 } 421 rcu_read_unlock(); 422 } 423 EXPORT_SYMBOL(xsk_tx_release); 424 425 bool xsk_tx_peek_desc(struct xsk_buff_pool *pool, struct xdp_desc *desc) 426 { 427 bool budget_exhausted = false; 428 struct xdp_sock *xs; 429 430 rcu_read_lock(); 431 again: 432 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) { 433 if (xs->tx_budget_spent >= MAX_PER_SOCKET_BUDGET) { 434 budget_exhausted = true; 435 continue; 436 } 437 438 if (!xskq_cons_peek_desc(xs->tx, desc, pool)) { 439 if (xskq_has_descs(xs->tx)) 440 xskq_cons_release(xs->tx); 441 continue; 442 } 443 444 xs->tx_budget_spent++; 445 446 /* This is the backpressure mechanism for the Tx path. 447 * Reserve space in the completion queue and only proceed 448 * if there is space in it. This avoids having to implement 449 * any buffering in the Tx path. 450 */ 451 if (xskq_prod_reserve_addr(pool->cq, desc->addr)) 452 goto out; 453 454 xskq_cons_release(xs->tx); 455 rcu_read_unlock(); 456 return true; 457 } 458 459 if (budget_exhausted) { 460 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) 461 xs->tx_budget_spent = 0; 462 463 budget_exhausted = false; 464 goto again; 465 } 466 467 out: 468 rcu_read_unlock(); 469 return false; 470 } 471 EXPORT_SYMBOL(xsk_tx_peek_desc); 472 473 static u32 xsk_tx_peek_release_fallback(struct xsk_buff_pool *pool, u32 max_entries) 474 { 475 struct xdp_desc *descs = pool->tx_descs; 476 u32 nb_pkts = 0; 477 478 while (nb_pkts < max_entries && xsk_tx_peek_desc(pool, &descs[nb_pkts])) 479 nb_pkts++; 480 481 xsk_tx_release(pool); 482 return nb_pkts; 483 } 484 485 u32 xsk_tx_peek_release_desc_batch(struct xsk_buff_pool *pool, u32 nb_pkts) 486 { 487 struct xdp_sock *xs; 488 489 rcu_read_lock(); 490 if (!list_is_singular(&pool->xsk_tx_list)) { 491 /* Fallback to the non-batched version */ 492 rcu_read_unlock(); 493 return xsk_tx_peek_release_fallback(pool, nb_pkts); 494 } 495 496 xs = list_first_or_null_rcu(&pool->xsk_tx_list, struct xdp_sock, tx_list); 497 if (!xs) { 498 nb_pkts = 0; 499 goto out; 500 } 501 502 nb_pkts = xskq_cons_nb_entries(xs->tx, nb_pkts); 503 504 /* This is the backpressure mechanism for the Tx path. Try to 505 * reserve space in the completion queue for all packets, but 506 * if there are fewer slots available, just process that many 507 * packets. This avoids having to implement any buffering in 508 * the Tx path. 509 */ 510 nb_pkts = xskq_prod_nb_free(pool->cq, nb_pkts); 511 if (!nb_pkts) 512 goto out; 513 514 nb_pkts = xskq_cons_read_desc_batch(xs->tx, pool, nb_pkts); 515 if (!nb_pkts) { 516 xs->tx->queue_empty_descs++; 517 goto out; 518 } 519 520 __xskq_cons_release(xs->tx); 521 xskq_prod_write_addr_batch(pool->cq, pool->tx_descs, nb_pkts); 522 xs->sk.sk_write_space(&xs->sk); 523 524 out: 525 rcu_read_unlock(); 526 return nb_pkts; 527 } 528 EXPORT_SYMBOL(xsk_tx_peek_release_desc_batch); 529 530 static int xsk_wakeup(struct xdp_sock *xs, u8 flags) 531 { 532 struct net_device *dev = xs->dev; 533 534 return dev->netdev_ops->ndo_xsk_wakeup(dev, xs->queue_id, flags); 535 } 536 537 static int xsk_cq_reserve_addr_locked(struct xdp_sock *xs, u64 addr) 538 { 539 unsigned long flags; 540 int ret; 541 542 spin_lock_irqsave(&xs->pool->cq_lock, flags); 543 ret = xskq_prod_reserve_addr(xs->pool->cq, addr); 544 spin_unlock_irqrestore(&xs->pool->cq_lock, flags); 545 546 return ret; 547 } 548 549 static void xsk_cq_submit_locked(struct xdp_sock *xs, u32 n) 550 { 551 unsigned long flags; 552 553 spin_lock_irqsave(&xs->pool->cq_lock, flags); 554 xskq_prod_submit_n(xs->pool->cq, n); 555 spin_unlock_irqrestore(&xs->pool->cq_lock, flags); 556 } 557 558 static void xsk_cq_cancel_locked(struct xdp_sock *xs, u32 n) 559 { 560 unsigned long flags; 561 562 spin_lock_irqsave(&xs->pool->cq_lock, flags); 563 xskq_prod_cancel_n(xs->pool->cq, n); 564 spin_unlock_irqrestore(&xs->pool->cq_lock, flags); 565 } 566 567 static u32 xsk_get_num_desc(struct sk_buff *skb) 568 { 569 return skb ? (long)skb_shinfo(skb)->destructor_arg : 0; 570 } 571 572 static void xsk_destruct_skb(struct sk_buff *skb) 573 { 574 xsk_cq_submit_locked(xdp_sk(skb->sk), xsk_get_num_desc(skb)); 575 sock_wfree(skb); 576 } 577 578 static void xsk_set_destructor_arg(struct sk_buff *skb) 579 { 580 long num = xsk_get_num_desc(xdp_sk(skb->sk)->skb) + 1; 581 582 skb_shinfo(skb)->destructor_arg = (void *)num; 583 } 584 585 static void xsk_consume_skb(struct sk_buff *skb) 586 { 587 struct xdp_sock *xs = xdp_sk(skb->sk); 588 589 skb->destructor = sock_wfree; 590 xsk_cq_cancel_locked(xs, xsk_get_num_desc(skb)); 591 /* Free skb without triggering the perf drop trace */ 592 consume_skb(skb); 593 xs->skb = NULL; 594 } 595 596 static void xsk_drop_skb(struct sk_buff *skb) 597 { 598 xdp_sk(skb->sk)->tx->invalid_descs += xsk_get_num_desc(skb); 599 xsk_consume_skb(skb); 600 } 601 602 static struct sk_buff *xsk_build_skb_zerocopy(struct xdp_sock *xs, 603 struct xdp_desc *desc) 604 { 605 struct xsk_buff_pool *pool = xs->pool; 606 u32 hr, len, ts, offset, copy, copied; 607 struct sk_buff *skb = xs->skb; 608 struct page *page; 609 void *buffer; 610 int err, i; 611 u64 addr; 612 613 if (!skb) { 614 hr = max(NET_SKB_PAD, L1_CACHE_ALIGN(xs->dev->needed_headroom)); 615 616 skb = sock_alloc_send_skb(&xs->sk, hr, 1, &err); 617 if (unlikely(!skb)) 618 return ERR_PTR(err); 619 620 skb_reserve(skb, hr); 621 } 622 623 addr = desc->addr; 624 len = desc->len; 625 ts = pool->unaligned ? len : pool->chunk_size; 626 627 buffer = xsk_buff_raw_get_data(pool, addr); 628 offset = offset_in_page(buffer); 629 addr = buffer - pool->addrs; 630 631 for (copied = 0, i = skb_shinfo(skb)->nr_frags; copied < len; i++) { 632 if (unlikely(i >= MAX_SKB_FRAGS)) 633 return ERR_PTR(-EOVERFLOW); 634 635 page = pool->umem->pgs[addr >> PAGE_SHIFT]; 636 get_page(page); 637 638 copy = min_t(u32, PAGE_SIZE - offset, len - copied); 639 skb_fill_page_desc(skb, i, page, offset, copy); 640 641 copied += copy; 642 addr += copy; 643 offset = 0; 644 } 645 646 skb->len += len; 647 skb->data_len += len; 648 skb->truesize += ts; 649 650 refcount_add(ts, &xs->sk.sk_wmem_alloc); 651 652 return skb; 653 } 654 655 static struct sk_buff *xsk_build_skb(struct xdp_sock *xs, 656 struct xdp_desc *desc) 657 { 658 struct net_device *dev = xs->dev; 659 struct sk_buff *skb = xs->skb; 660 int err; 661 662 if (dev->priv_flags & IFF_TX_SKB_NO_LINEAR) { 663 skb = xsk_build_skb_zerocopy(xs, desc); 664 if (IS_ERR(skb)) { 665 err = PTR_ERR(skb); 666 goto free_err; 667 } 668 } else { 669 u32 hr, tr, len; 670 void *buffer; 671 672 buffer = xsk_buff_raw_get_data(xs->pool, desc->addr); 673 len = desc->len; 674 675 if (!skb) { 676 hr = max(NET_SKB_PAD, L1_CACHE_ALIGN(dev->needed_headroom)); 677 tr = dev->needed_tailroom; 678 skb = sock_alloc_send_skb(&xs->sk, hr + len + tr, 1, &err); 679 if (unlikely(!skb)) 680 goto free_err; 681 682 skb_reserve(skb, hr); 683 skb_put(skb, len); 684 685 err = skb_store_bits(skb, 0, buffer, len); 686 if (unlikely(err)) { 687 kfree_skb(skb); 688 goto free_err; 689 } 690 } else { 691 int nr_frags = skb_shinfo(skb)->nr_frags; 692 struct page *page; 693 u8 *vaddr; 694 695 if (unlikely(nr_frags == (MAX_SKB_FRAGS - 1) && xp_mb_desc(desc))) { 696 err = -EOVERFLOW; 697 goto free_err; 698 } 699 700 page = alloc_page(xs->sk.sk_allocation); 701 if (unlikely(!page)) { 702 err = -EAGAIN; 703 goto free_err; 704 } 705 706 vaddr = kmap_local_page(page); 707 memcpy(vaddr, buffer, len); 708 kunmap_local(vaddr); 709 710 skb_add_rx_frag(skb, nr_frags, page, 0, len, 0); 711 } 712 } 713 714 skb->dev = dev; 715 skb->priority = READ_ONCE(xs->sk.sk_priority); 716 skb->mark = READ_ONCE(xs->sk.sk_mark); 717 skb->destructor = xsk_destruct_skb; 718 xsk_set_destructor_arg(skb); 719 720 return skb; 721 722 free_err: 723 if (err == -EOVERFLOW) { 724 /* Drop the packet */ 725 xsk_set_destructor_arg(xs->skb); 726 xsk_drop_skb(xs->skb); 727 xskq_cons_release(xs->tx); 728 } else { 729 /* Let application retry */ 730 xsk_cq_cancel_locked(xs, 1); 731 } 732 733 return ERR_PTR(err); 734 } 735 736 static int __xsk_generic_xmit(struct sock *sk) 737 { 738 struct xdp_sock *xs = xdp_sk(sk); 739 u32 max_batch = TX_BATCH_SIZE; 740 bool sent_frame = false; 741 struct xdp_desc desc; 742 struct sk_buff *skb; 743 int err = 0; 744 745 mutex_lock(&xs->mutex); 746 747 /* Since we dropped the RCU read lock, the socket state might have changed. */ 748 if (unlikely(!xsk_is_bound(xs))) { 749 err = -ENXIO; 750 goto out; 751 } 752 753 if (xs->queue_id >= xs->dev->real_num_tx_queues) 754 goto out; 755 756 while (xskq_cons_peek_desc(xs->tx, &desc, xs->pool)) { 757 if (max_batch-- == 0) { 758 err = -EAGAIN; 759 goto out; 760 } 761 762 /* This is the backpressure mechanism for the Tx path. 763 * Reserve space in the completion queue and only proceed 764 * if there is space in it. This avoids having to implement 765 * any buffering in the Tx path. 766 */ 767 if (xsk_cq_reserve_addr_locked(xs, desc.addr)) 768 goto out; 769 770 skb = xsk_build_skb(xs, &desc); 771 if (IS_ERR(skb)) { 772 err = PTR_ERR(skb); 773 if (err != -EOVERFLOW) 774 goto out; 775 err = 0; 776 continue; 777 } 778 779 xskq_cons_release(xs->tx); 780 781 if (xp_mb_desc(&desc)) { 782 xs->skb = skb; 783 continue; 784 } 785 786 err = __dev_direct_xmit(skb, xs->queue_id); 787 if (err == NETDEV_TX_BUSY) { 788 /* Tell user-space to retry the send */ 789 xskq_cons_cancel_n(xs->tx, xsk_get_num_desc(skb)); 790 xsk_consume_skb(skb); 791 err = -EAGAIN; 792 goto out; 793 } 794 795 /* Ignore NET_XMIT_CN as packet might have been sent */ 796 if (err == NET_XMIT_DROP) { 797 /* SKB completed but not sent */ 798 err = -EBUSY; 799 xs->skb = NULL; 800 goto out; 801 } 802 803 sent_frame = true; 804 xs->skb = NULL; 805 } 806 807 if (xskq_has_descs(xs->tx)) { 808 if (xs->skb) 809 xsk_drop_skb(xs->skb); 810 xskq_cons_release(xs->tx); 811 } 812 813 out: 814 if (sent_frame) 815 if (xsk_tx_writeable(xs)) 816 sk->sk_write_space(sk); 817 818 mutex_unlock(&xs->mutex); 819 return err; 820 } 821 822 static int xsk_generic_xmit(struct sock *sk) 823 { 824 int ret; 825 826 /* Drop the RCU lock since the SKB path might sleep. */ 827 rcu_read_unlock(); 828 ret = __xsk_generic_xmit(sk); 829 /* Reaquire RCU lock before going into common code. */ 830 rcu_read_lock(); 831 832 return ret; 833 } 834 835 static bool xsk_no_wakeup(struct sock *sk) 836 { 837 #ifdef CONFIG_NET_RX_BUSY_POLL 838 /* Prefer busy-polling, skip the wakeup. */ 839 return READ_ONCE(sk->sk_prefer_busy_poll) && READ_ONCE(sk->sk_ll_usec) && 840 READ_ONCE(sk->sk_napi_id) >= MIN_NAPI_ID; 841 #else 842 return false; 843 #endif 844 } 845 846 static int xsk_check_common(struct xdp_sock *xs) 847 { 848 if (unlikely(!xsk_is_bound(xs))) 849 return -ENXIO; 850 if (unlikely(!(xs->dev->flags & IFF_UP))) 851 return -ENETDOWN; 852 853 return 0; 854 } 855 856 static int __xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len) 857 { 858 bool need_wait = !(m->msg_flags & MSG_DONTWAIT); 859 struct sock *sk = sock->sk; 860 struct xdp_sock *xs = xdp_sk(sk); 861 struct xsk_buff_pool *pool; 862 int err; 863 864 err = xsk_check_common(xs); 865 if (err) 866 return err; 867 if (unlikely(need_wait)) 868 return -EOPNOTSUPP; 869 if (unlikely(!xs->tx)) 870 return -ENOBUFS; 871 872 if (sk_can_busy_loop(sk)) { 873 if (xs->zc) 874 __sk_mark_napi_id_once(sk, xsk_pool_get_napi_id(xs->pool)); 875 sk_busy_loop(sk, 1); /* only support non-blocking sockets */ 876 } 877 878 if (xs->zc && xsk_no_wakeup(sk)) 879 return 0; 880 881 pool = xs->pool; 882 if (pool->cached_need_wakeup & XDP_WAKEUP_TX) { 883 if (xs->zc) 884 return xsk_wakeup(xs, XDP_WAKEUP_TX); 885 return xsk_generic_xmit(sk); 886 } 887 return 0; 888 } 889 890 static int xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len) 891 { 892 int ret; 893 894 rcu_read_lock(); 895 ret = __xsk_sendmsg(sock, m, total_len); 896 rcu_read_unlock(); 897 898 return ret; 899 } 900 901 static int __xsk_recvmsg(struct socket *sock, struct msghdr *m, size_t len, int flags) 902 { 903 bool need_wait = !(flags & MSG_DONTWAIT); 904 struct sock *sk = sock->sk; 905 struct xdp_sock *xs = xdp_sk(sk); 906 int err; 907 908 err = xsk_check_common(xs); 909 if (err) 910 return err; 911 if (unlikely(!xs->rx)) 912 return -ENOBUFS; 913 if (unlikely(need_wait)) 914 return -EOPNOTSUPP; 915 916 if (sk_can_busy_loop(sk)) 917 sk_busy_loop(sk, 1); /* only support non-blocking sockets */ 918 919 if (xsk_no_wakeup(sk)) 920 return 0; 921 922 if (xs->pool->cached_need_wakeup & XDP_WAKEUP_RX && xs->zc) 923 return xsk_wakeup(xs, XDP_WAKEUP_RX); 924 return 0; 925 } 926 927 static int xsk_recvmsg(struct socket *sock, struct msghdr *m, size_t len, int flags) 928 { 929 int ret; 930 931 rcu_read_lock(); 932 ret = __xsk_recvmsg(sock, m, len, flags); 933 rcu_read_unlock(); 934 935 return ret; 936 } 937 938 static __poll_t xsk_poll(struct file *file, struct socket *sock, 939 struct poll_table_struct *wait) 940 { 941 __poll_t mask = 0; 942 struct sock *sk = sock->sk; 943 struct xdp_sock *xs = xdp_sk(sk); 944 struct xsk_buff_pool *pool; 945 946 sock_poll_wait(file, sock, wait); 947 948 rcu_read_lock(); 949 if (xsk_check_common(xs)) 950 goto skip_tx; 951 952 pool = xs->pool; 953 954 if (pool->cached_need_wakeup) { 955 if (xs->zc) 956 xsk_wakeup(xs, pool->cached_need_wakeup); 957 else if (xs->tx) 958 /* Poll needs to drive Tx also in copy mode */ 959 xsk_generic_xmit(sk); 960 } 961 962 skip_tx: 963 if (xs->rx && !xskq_prod_is_empty(xs->rx)) 964 mask |= EPOLLIN | EPOLLRDNORM; 965 if (xs->tx && xsk_tx_writeable(xs)) 966 mask |= EPOLLOUT | EPOLLWRNORM; 967 968 rcu_read_unlock(); 969 return mask; 970 } 971 972 static int xsk_init_queue(u32 entries, struct xsk_queue **queue, 973 bool umem_queue) 974 { 975 struct xsk_queue *q; 976 977 if (entries == 0 || *queue || !is_power_of_2(entries)) 978 return -EINVAL; 979 980 q = xskq_create(entries, umem_queue); 981 if (!q) 982 return -ENOMEM; 983 984 /* Make sure queue is ready before it can be seen by others */ 985 smp_wmb(); 986 WRITE_ONCE(*queue, q); 987 return 0; 988 } 989 990 static void xsk_unbind_dev(struct xdp_sock *xs) 991 { 992 struct net_device *dev = xs->dev; 993 994 if (xs->state != XSK_BOUND) 995 return; 996 WRITE_ONCE(xs->state, XSK_UNBOUND); 997 998 /* Wait for driver to stop using the xdp socket. */ 999 xp_del_xsk(xs->pool, xs); 1000 synchronize_net(); 1001 dev_put(dev); 1002 } 1003 1004 static struct xsk_map *xsk_get_map_list_entry(struct xdp_sock *xs, 1005 struct xdp_sock __rcu ***map_entry) 1006 { 1007 struct xsk_map *map = NULL; 1008 struct xsk_map_node *node; 1009 1010 *map_entry = NULL; 1011 1012 spin_lock_bh(&xs->map_list_lock); 1013 node = list_first_entry_or_null(&xs->map_list, struct xsk_map_node, 1014 node); 1015 if (node) { 1016 bpf_map_inc(&node->map->map); 1017 map = node->map; 1018 *map_entry = node->map_entry; 1019 } 1020 spin_unlock_bh(&xs->map_list_lock); 1021 return map; 1022 } 1023 1024 static void xsk_delete_from_maps(struct xdp_sock *xs) 1025 { 1026 /* This function removes the current XDP socket from all the 1027 * maps it resides in. We need to take extra care here, due to 1028 * the two locks involved. Each map has a lock synchronizing 1029 * updates to the entries, and each socket has a lock that 1030 * synchronizes access to the list of maps (map_list). For 1031 * deadlock avoidance the locks need to be taken in the order 1032 * "map lock"->"socket map list lock". We start off by 1033 * accessing the socket map list, and take a reference to the 1034 * map to guarantee existence between the 1035 * xsk_get_map_list_entry() and xsk_map_try_sock_delete() 1036 * calls. Then we ask the map to remove the socket, which 1037 * tries to remove the socket from the map. Note that there 1038 * might be updates to the map between 1039 * xsk_get_map_list_entry() and xsk_map_try_sock_delete(). 1040 */ 1041 struct xdp_sock __rcu **map_entry = NULL; 1042 struct xsk_map *map; 1043 1044 while ((map = xsk_get_map_list_entry(xs, &map_entry))) { 1045 xsk_map_try_sock_delete(map, xs, map_entry); 1046 bpf_map_put(&map->map); 1047 } 1048 } 1049 1050 static int xsk_release(struct socket *sock) 1051 { 1052 struct sock *sk = sock->sk; 1053 struct xdp_sock *xs = xdp_sk(sk); 1054 struct net *net; 1055 1056 if (!sk) 1057 return 0; 1058 1059 net = sock_net(sk); 1060 1061 if (xs->skb) 1062 xsk_drop_skb(xs->skb); 1063 1064 mutex_lock(&net->xdp.lock); 1065 sk_del_node_init_rcu(sk); 1066 mutex_unlock(&net->xdp.lock); 1067 1068 sock_prot_inuse_add(net, sk->sk_prot, -1); 1069 1070 xsk_delete_from_maps(xs); 1071 mutex_lock(&xs->mutex); 1072 xsk_unbind_dev(xs); 1073 mutex_unlock(&xs->mutex); 1074 1075 xskq_destroy(xs->rx); 1076 xskq_destroy(xs->tx); 1077 xskq_destroy(xs->fq_tmp); 1078 xskq_destroy(xs->cq_tmp); 1079 1080 sock_orphan(sk); 1081 sock->sk = NULL; 1082 1083 sock_put(sk); 1084 1085 return 0; 1086 } 1087 1088 static struct socket *xsk_lookup_xsk_from_fd(int fd) 1089 { 1090 struct socket *sock; 1091 int err; 1092 1093 sock = sockfd_lookup(fd, &err); 1094 if (!sock) 1095 return ERR_PTR(-ENOTSOCK); 1096 1097 if (sock->sk->sk_family != PF_XDP) { 1098 sockfd_put(sock); 1099 return ERR_PTR(-ENOPROTOOPT); 1100 } 1101 1102 return sock; 1103 } 1104 1105 static bool xsk_validate_queues(struct xdp_sock *xs) 1106 { 1107 return xs->fq_tmp && xs->cq_tmp; 1108 } 1109 1110 static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len) 1111 { 1112 struct sockaddr_xdp *sxdp = (struct sockaddr_xdp *)addr; 1113 struct sock *sk = sock->sk; 1114 struct xdp_sock *xs = xdp_sk(sk); 1115 struct net_device *dev; 1116 int bound_dev_if; 1117 u32 flags, qid; 1118 int err = 0; 1119 1120 if (addr_len < sizeof(struct sockaddr_xdp)) 1121 return -EINVAL; 1122 if (sxdp->sxdp_family != AF_XDP) 1123 return -EINVAL; 1124 1125 flags = sxdp->sxdp_flags; 1126 if (flags & ~(XDP_SHARED_UMEM | XDP_COPY | XDP_ZEROCOPY | 1127 XDP_USE_NEED_WAKEUP | XDP_USE_SG)) 1128 return -EINVAL; 1129 1130 bound_dev_if = READ_ONCE(sk->sk_bound_dev_if); 1131 if (bound_dev_if && bound_dev_if != sxdp->sxdp_ifindex) 1132 return -EINVAL; 1133 1134 rtnl_lock(); 1135 mutex_lock(&xs->mutex); 1136 if (xs->state != XSK_READY) { 1137 err = -EBUSY; 1138 goto out_release; 1139 } 1140 1141 dev = dev_get_by_index(sock_net(sk), sxdp->sxdp_ifindex); 1142 if (!dev) { 1143 err = -ENODEV; 1144 goto out_release; 1145 } 1146 1147 if (!xs->rx && !xs->tx) { 1148 err = -EINVAL; 1149 goto out_unlock; 1150 } 1151 1152 qid = sxdp->sxdp_queue_id; 1153 1154 if (flags & XDP_SHARED_UMEM) { 1155 struct xdp_sock *umem_xs; 1156 struct socket *sock; 1157 1158 if ((flags & XDP_COPY) || (flags & XDP_ZEROCOPY) || 1159 (flags & XDP_USE_NEED_WAKEUP) || (flags & XDP_USE_SG)) { 1160 /* Cannot specify flags for shared sockets. */ 1161 err = -EINVAL; 1162 goto out_unlock; 1163 } 1164 1165 if (xs->umem) { 1166 /* We have already our own. */ 1167 err = -EINVAL; 1168 goto out_unlock; 1169 } 1170 1171 sock = xsk_lookup_xsk_from_fd(sxdp->sxdp_shared_umem_fd); 1172 if (IS_ERR(sock)) { 1173 err = PTR_ERR(sock); 1174 goto out_unlock; 1175 } 1176 1177 umem_xs = xdp_sk(sock->sk); 1178 if (!xsk_is_bound(umem_xs)) { 1179 err = -EBADF; 1180 sockfd_put(sock); 1181 goto out_unlock; 1182 } 1183 1184 if (umem_xs->queue_id != qid || umem_xs->dev != dev) { 1185 /* Share the umem with another socket on another qid 1186 * and/or device. 1187 */ 1188 xs->pool = xp_create_and_assign_umem(xs, 1189 umem_xs->umem); 1190 if (!xs->pool) { 1191 err = -ENOMEM; 1192 sockfd_put(sock); 1193 goto out_unlock; 1194 } 1195 1196 err = xp_assign_dev_shared(xs->pool, umem_xs, dev, 1197 qid); 1198 if (err) { 1199 xp_destroy(xs->pool); 1200 xs->pool = NULL; 1201 sockfd_put(sock); 1202 goto out_unlock; 1203 } 1204 } else { 1205 /* Share the buffer pool with the other socket. */ 1206 if (xs->fq_tmp || xs->cq_tmp) { 1207 /* Do not allow setting your own fq or cq. */ 1208 err = -EINVAL; 1209 sockfd_put(sock); 1210 goto out_unlock; 1211 } 1212 1213 xp_get_pool(umem_xs->pool); 1214 xs->pool = umem_xs->pool; 1215 1216 /* If underlying shared umem was created without Tx 1217 * ring, allocate Tx descs array that Tx batching API 1218 * utilizes 1219 */ 1220 if (xs->tx && !xs->pool->tx_descs) { 1221 err = xp_alloc_tx_descs(xs->pool, xs); 1222 if (err) { 1223 xp_put_pool(xs->pool); 1224 xs->pool = NULL; 1225 sockfd_put(sock); 1226 goto out_unlock; 1227 } 1228 } 1229 } 1230 1231 xdp_get_umem(umem_xs->umem); 1232 WRITE_ONCE(xs->umem, umem_xs->umem); 1233 sockfd_put(sock); 1234 } else if (!xs->umem || !xsk_validate_queues(xs)) { 1235 err = -EINVAL; 1236 goto out_unlock; 1237 } else { 1238 /* This xsk has its own umem. */ 1239 xs->pool = xp_create_and_assign_umem(xs, xs->umem); 1240 if (!xs->pool) { 1241 err = -ENOMEM; 1242 goto out_unlock; 1243 } 1244 1245 err = xp_assign_dev(xs->pool, dev, qid, flags); 1246 if (err) { 1247 xp_destroy(xs->pool); 1248 xs->pool = NULL; 1249 goto out_unlock; 1250 } 1251 } 1252 1253 /* FQ and CQ are now owned by the buffer pool and cleaned up with it. */ 1254 xs->fq_tmp = NULL; 1255 xs->cq_tmp = NULL; 1256 1257 xs->dev = dev; 1258 xs->zc = xs->umem->zc; 1259 xs->sg = !!(xs->umem->flags & XDP_UMEM_SG_FLAG); 1260 xs->queue_id = qid; 1261 xp_add_xsk(xs->pool, xs); 1262 1263 out_unlock: 1264 if (err) { 1265 dev_put(dev); 1266 } else { 1267 /* Matches smp_rmb() in bind() for shared umem 1268 * sockets, and xsk_is_bound(). 1269 */ 1270 smp_wmb(); 1271 WRITE_ONCE(xs->state, XSK_BOUND); 1272 } 1273 out_release: 1274 mutex_unlock(&xs->mutex); 1275 rtnl_unlock(); 1276 return err; 1277 } 1278 1279 struct xdp_umem_reg_v1 { 1280 __u64 addr; /* Start of packet data area */ 1281 __u64 len; /* Length of packet data area */ 1282 __u32 chunk_size; 1283 __u32 headroom; 1284 }; 1285 1286 static int xsk_setsockopt(struct socket *sock, int level, int optname, 1287 sockptr_t optval, unsigned int optlen) 1288 { 1289 struct sock *sk = sock->sk; 1290 struct xdp_sock *xs = xdp_sk(sk); 1291 int err; 1292 1293 if (level != SOL_XDP) 1294 return -ENOPROTOOPT; 1295 1296 switch (optname) { 1297 case XDP_RX_RING: 1298 case XDP_TX_RING: 1299 { 1300 struct xsk_queue **q; 1301 int entries; 1302 1303 if (optlen < sizeof(entries)) 1304 return -EINVAL; 1305 if (copy_from_sockptr(&entries, optval, sizeof(entries))) 1306 return -EFAULT; 1307 1308 mutex_lock(&xs->mutex); 1309 if (xs->state != XSK_READY) { 1310 mutex_unlock(&xs->mutex); 1311 return -EBUSY; 1312 } 1313 q = (optname == XDP_TX_RING) ? &xs->tx : &xs->rx; 1314 err = xsk_init_queue(entries, q, false); 1315 if (!err && optname == XDP_TX_RING) 1316 /* Tx needs to be explicitly woken up the first time */ 1317 xs->tx->ring->flags |= XDP_RING_NEED_WAKEUP; 1318 mutex_unlock(&xs->mutex); 1319 return err; 1320 } 1321 case XDP_UMEM_REG: 1322 { 1323 size_t mr_size = sizeof(struct xdp_umem_reg); 1324 struct xdp_umem_reg mr = {}; 1325 struct xdp_umem *umem; 1326 1327 if (optlen < sizeof(struct xdp_umem_reg_v1)) 1328 return -EINVAL; 1329 else if (optlen < sizeof(mr)) 1330 mr_size = sizeof(struct xdp_umem_reg_v1); 1331 1332 if (copy_from_sockptr(&mr, optval, mr_size)) 1333 return -EFAULT; 1334 1335 mutex_lock(&xs->mutex); 1336 if (xs->state != XSK_READY || xs->umem) { 1337 mutex_unlock(&xs->mutex); 1338 return -EBUSY; 1339 } 1340 1341 umem = xdp_umem_create(&mr); 1342 if (IS_ERR(umem)) { 1343 mutex_unlock(&xs->mutex); 1344 return PTR_ERR(umem); 1345 } 1346 1347 /* Make sure umem is ready before it can be seen by others */ 1348 smp_wmb(); 1349 WRITE_ONCE(xs->umem, umem); 1350 mutex_unlock(&xs->mutex); 1351 return 0; 1352 } 1353 case XDP_UMEM_FILL_RING: 1354 case XDP_UMEM_COMPLETION_RING: 1355 { 1356 struct xsk_queue **q; 1357 int entries; 1358 1359 if (copy_from_sockptr(&entries, optval, sizeof(entries))) 1360 return -EFAULT; 1361 1362 mutex_lock(&xs->mutex); 1363 if (xs->state != XSK_READY) { 1364 mutex_unlock(&xs->mutex); 1365 return -EBUSY; 1366 } 1367 1368 q = (optname == XDP_UMEM_FILL_RING) ? &xs->fq_tmp : 1369 &xs->cq_tmp; 1370 err = xsk_init_queue(entries, q, true); 1371 mutex_unlock(&xs->mutex); 1372 return err; 1373 } 1374 default: 1375 break; 1376 } 1377 1378 return -ENOPROTOOPT; 1379 } 1380 1381 static void xsk_enter_rxtx_offsets(struct xdp_ring_offset_v1 *ring) 1382 { 1383 ring->producer = offsetof(struct xdp_rxtx_ring, ptrs.producer); 1384 ring->consumer = offsetof(struct xdp_rxtx_ring, ptrs.consumer); 1385 ring->desc = offsetof(struct xdp_rxtx_ring, desc); 1386 } 1387 1388 static void xsk_enter_umem_offsets(struct xdp_ring_offset_v1 *ring) 1389 { 1390 ring->producer = offsetof(struct xdp_umem_ring, ptrs.producer); 1391 ring->consumer = offsetof(struct xdp_umem_ring, ptrs.consumer); 1392 ring->desc = offsetof(struct xdp_umem_ring, desc); 1393 } 1394 1395 struct xdp_statistics_v1 { 1396 __u64 rx_dropped; 1397 __u64 rx_invalid_descs; 1398 __u64 tx_invalid_descs; 1399 }; 1400 1401 static int xsk_getsockopt(struct socket *sock, int level, int optname, 1402 char __user *optval, int __user *optlen) 1403 { 1404 struct sock *sk = sock->sk; 1405 struct xdp_sock *xs = xdp_sk(sk); 1406 int len; 1407 1408 if (level != SOL_XDP) 1409 return -ENOPROTOOPT; 1410 1411 if (get_user(len, optlen)) 1412 return -EFAULT; 1413 if (len < 0) 1414 return -EINVAL; 1415 1416 switch (optname) { 1417 case XDP_STATISTICS: 1418 { 1419 struct xdp_statistics stats = {}; 1420 bool extra_stats = true; 1421 size_t stats_size; 1422 1423 if (len < sizeof(struct xdp_statistics_v1)) { 1424 return -EINVAL; 1425 } else if (len < sizeof(stats)) { 1426 extra_stats = false; 1427 stats_size = sizeof(struct xdp_statistics_v1); 1428 } else { 1429 stats_size = sizeof(stats); 1430 } 1431 1432 mutex_lock(&xs->mutex); 1433 stats.rx_dropped = xs->rx_dropped; 1434 if (extra_stats) { 1435 stats.rx_ring_full = xs->rx_queue_full; 1436 stats.rx_fill_ring_empty_descs = 1437 xs->pool ? xskq_nb_queue_empty_descs(xs->pool->fq) : 0; 1438 stats.tx_ring_empty_descs = xskq_nb_queue_empty_descs(xs->tx); 1439 } else { 1440 stats.rx_dropped += xs->rx_queue_full; 1441 } 1442 stats.rx_invalid_descs = xskq_nb_invalid_descs(xs->rx); 1443 stats.tx_invalid_descs = xskq_nb_invalid_descs(xs->tx); 1444 mutex_unlock(&xs->mutex); 1445 1446 if (copy_to_user(optval, &stats, stats_size)) 1447 return -EFAULT; 1448 if (put_user(stats_size, optlen)) 1449 return -EFAULT; 1450 1451 return 0; 1452 } 1453 case XDP_MMAP_OFFSETS: 1454 { 1455 struct xdp_mmap_offsets off; 1456 struct xdp_mmap_offsets_v1 off_v1; 1457 bool flags_supported = true; 1458 void *to_copy; 1459 1460 if (len < sizeof(off_v1)) 1461 return -EINVAL; 1462 else if (len < sizeof(off)) 1463 flags_supported = false; 1464 1465 if (flags_supported) { 1466 /* xdp_ring_offset is identical to xdp_ring_offset_v1 1467 * except for the flags field added to the end. 1468 */ 1469 xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *) 1470 &off.rx); 1471 xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *) 1472 &off.tx); 1473 xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *) 1474 &off.fr); 1475 xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *) 1476 &off.cr); 1477 off.rx.flags = offsetof(struct xdp_rxtx_ring, 1478 ptrs.flags); 1479 off.tx.flags = offsetof(struct xdp_rxtx_ring, 1480 ptrs.flags); 1481 off.fr.flags = offsetof(struct xdp_umem_ring, 1482 ptrs.flags); 1483 off.cr.flags = offsetof(struct xdp_umem_ring, 1484 ptrs.flags); 1485 1486 len = sizeof(off); 1487 to_copy = &off; 1488 } else { 1489 xsk_enter_rxtx_offsets(&off_v1.rx); 1490 xsk_enter_rxtx_offsets(&off_v1.tx); 1491 xsk_enter_umem_offsets(&off_v1.fr); 1492 xsk_enter_umem_offsets(&off_v1.cr); 1493 1494 len = sizeof(off_v1); 1495 to_copy = &off_v1; 1496 } 1497 1498 if (copy_to_user(optval, to_copy, len)) 1499 return -EFAULT; 1500 if (put_user(len, optlen)) 1501 return -EFAULT; 1502 1503 return 0; 1504 } 1505 case XDP_OPTIONS: 1506 { 1507 struct xdp_options opts = {}; 1508 1509 if (len < sizeof(opts)) 1510 return -EINVAL; 1511 1512 mutex_lock(&xs->mutex); 1513 if (xs->zc) 1514 opts.flags |= XDP_OPTIONS_ZEROCOPY; 1515 mutex_unlock(&xs->mutex); 1516 1517 len = sizeof(opts); 1518 if (copy_to_user(optval, &opts, len)) 1519 return -EFAULT; 1520 if (put_user(len, optlen)) 1521 return -EFAULT; 1522 1523 return 0; 1524 } 1525 default: 1526 break; 1527 } 1528 1529 return -EOPNOTSUPP; 1530 } 1531 1532 static int xsk_mmap(struct file *file, struct socket *sock, 1533 struct vm_area_struct *vma) 1534 { 1535 loff_t offset = (loff_t)vma->vm_pgoff << PAGE_SHIFT; 1536 unsigned long size = vma->vm_end - vma->vm_start; 1537 struct xdp_sock *xs = xdp_sk(sock->sk); 1538 int state = READ_ONCE(xs->state); 1539 struct xsk_queue *q = NULL; 1540 1541 if (state != XSK_READY && state != XSK_BOUND) 1542 return -EBUSY; 1543 1544 if (offset == XDP_PGOFF_RX_RING) { 1545 q = READ_ONCE(xs->rx); 1546 } else if (offset == XDP_PGOFF_TX_RING) { 1547 q = READ_ONCE(xs->tx); 1548 } else { 1549 /* Matches the smp_wmb() in XDP_UMEM_REG */ 1550 smp_rmb(); 1551 if (offset == XDP_UMEM_PGOFF_FILL_RING) 1552 q = state == XSK_READY ? READ_ONCE(xs->fq_tmp) : 1553 READ_ONCE(xs->pool->fq); 1554 else if (offset == XDP_UMEM_PGOFF_COMPLETION_RING) 1555 q = state == XSK_READY ? READ_ONCE(xs->cq_tmp) : 1556 READ_ONCE(xs->pool->cq); 1557 } 1558 1559 if (!q) 1560 return -EINVAL; 1561 1562 /* Matches the smp_wmb() in xsk_init_queue */ 1563 smp_rmb(); 1564 if (size > q->ring_vmalloc_size) 1565 return -EINVAL; 1566 1567 return remap_vmalloc_range(vma, q->ring, 0); 1568 } 1569 1570 static int xsk_notifier(struct notifier_block *this, 1571 unsigned long msg, void *ptr) 1572 { 1573 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1574 struct net *net = dev_net(dev); 1575 struct sock *sk; 1576 1577 switch (msg) { 1578 case NETDEV_UNREGISTER: 1579 mutex_lock(&net->xdp.lock); 1580 sk_for_each(sk, &net->xdp.list) { 1581 struct xdp_sock *xs = xdp_sk(sk); 1582 1583 mutex_lock(&xs->mutex); 1584 if (xs->dev == dev) { 1585 sk->sk_err = ENETDOWN; 1586 if (!sock_flag(sk, SOCK_DEAD)) 1587 sk_error_report(sk); 1588 1589 xsk_unbind_dev(xs); 1590 1591 /* Clear device references. */ 1592 xp_clear_dev(xs->pool); 1593 } 1594 mutex_unlock(&xs->mutex); 1595 } 1596 mutex_unlock(&net->xdp.lock); 1597 break; 1598 } 1599 return NOTIFY_DONE; 1600 } 1601 1602 static struct proto xsk_proto = { 1603 .name = "XDP", 1604 .owner = THIS_MODULE, 1605 .obj_size = sizeof(struct xdp_sock), 1606 }; 1607 1608 static const struct proto_ops xsk_proto_ops = { 1609 .family = PF_XDP, 1610 .owner = THIS_MODULE, 1611 .release = xsk_release, 1612 .bind = xsk_bind, 1613 .connect = sock_no_connect, 1614 .socketpair = sock_no_socketpair, 1615 .accept = sock_no_accept, 1616 .getname = sock_no_getname, 1617 .poll = xsk_poll, 1618 .ioctl = sock_no_ioctl, 1619 .listen = sock_no_listen, 1620 .shutdown = sock_no_shutdown, 1621 .setsockopt = xsk_setsockopt, 1622 .getsockopt = xsk_getsockopt, 1623 .sendmsg = xsk_sendmsg, 1624 .recvmsg = xsk_recvmsg, 1625 .mmap = xsk_mmap, 1626 }; 1627 1628 static void xsk_destruct(struct sock *sk) 1629 { 1630 struct xdp_sock *xs = xdp_sk(sk); 1631 1632 if (!sock_flag(sk, SOCK_DEAD)) 1633 return; 1634 1635 if (!xp_put_pool(xs->pool)) 1636 xdp_put_umem(xs->umem, !xs->pool); 1637 } 1638 1639 static int xsk_create(struct net *net, struct socket *sock, int protocol, 1640 int kern) 1641 { 1642 struct xdp_sock *xs; 1643 struct sock *sk; 1644 1645 if (!ns_capable(net->user_ns, CAP_NET_RAW)) 1646 return -EPERM; 1647 if (sock->type != SOCK_RAW) 1648 return -ESOCKTNOSUPPORT; 1649 1650 if (protocol) 1651 return -EPROTONOSUPPORT; 1652 1653 sock->state = SS_UNCONNECTED; 1654 1655 sk = sk_alloc(net, PF_XDP, GFP_KERNEL, &xsk_proto, kern); 1656 if (!sk) 1657 return -ENOBUFS; 1658 1659 sock->ops = &xsk_proto_ops; 1660 1661 sock_init_data(sock, sk); 1662 1663 sk->sk_family = PF_XDP; 1664 1665 sk->sk_destruct = xsk_destruct; 1666 1667 sock_set_flag(sk, SOCK_RCU_FREE); 1668 1669 xs = xdp_sk(sk); 1670 xs->state = XSK_READY; 1671 mutex_init(&xs->mutex); 1672 spin_lock_init(&xs->rx_lock); 1673 1674 INIT_LIST_HEAD(&xs->map_list); 1675 spin_lock_init(&xs->map_list_lock); 1676 1677 mutex_lock(&net->xdp.lock); 1678 sk_add_node_rcu(sk, &net->xdp.list); 1679 mutex_unlock(&net->xdp.lock); 1680 1681 sock_prot_inuse_add(net, &xsk_proto, 1); 1682 1683 return 0; 1684 } 1685 1686 static const struct net_proto_family xsk_family_ops = { 1687 .family = PF_XDP, 1688 .create = xsk_create, 1689 .owner = THIS_MODULE, 1690 }; 1691 1692 static struct notifier_block xsk_netdev_notifier = { 1693 .notifier_call = xsk_notifier, 1694 }; 1695 1696 static int __net_init xsk_net_init(struct net *net) 1697 { 1698 mutex_init(&net->xdp.lock); 1699 INIT_HLIST_HEAD(&net->xdp.list); 1700 return 0; 1701 } 1702 1703 static void __net_exit xsk_net_exit(struct net *net) 1704 { 1705 WARN_ON_ONCE(!hlist_empty(&net->xdp.list)); 1706 } 1707 1708 static struct pernet_operations xsk_net_ops = { 1709 .init = xsk_net_init, 1710 .exit = xsk_net_exit, 1711 }; 1712 1713 static int __init xsk_init(void) 1714 { 1715 int err, cpu; 1716 1717 err = proto_register(&xsk_proto, 0 /* no slab */); 1718 if (err) 1719 goto out; 1720 1721 err = sock_register(&xsk_family_ops); 1722 if (err) 1723 goto out_proto; 1724 1725 err = register_pernet_subsys(&xsk_net_ops); 1726 if (err) 1727 goto out_sk; 1728 1729 err = register_netdevice_notifier(&xsk_netdev_notifier); 1730 if (err) 1731 goto out_pernet; 1732 1733 for_each_possible_cpu(cpu) 1734 INIT_LIST_HEAD(&per_cpu(xskmap_flush_list, cpu)); 1735 return 0; 1736 1737 out_pernet: 1738 unregister_pernet_subsys(&xsk_net_ops); 1739 out_sk: 1740 sock_unregister(PF_XDP); 1741 out_proto: 1742 proto_unregister(&xsk_proto); 1743 out: 1744 return err; 1745 } 1746 1747 fs_initcall(xsk_init); 1748