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