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): Bj��rn T��pel <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 38static DEFINE_PER_CPU(struct list_head, xskmap_flush_list); 39 40void 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} 48EXPORT_SYMBOL(xsk_set_rx_need_wakeup); 49 50void 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} 65EXPORT_SYMBOL(xsk_set_tx_need_wakeup); 66 67void 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} 75EXPORT_SYMBOL(xsk_clear_rx_need_wakeup); 76 77void 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} 92EXPORT_SYMBOL(xsk_clear_tx_need_wakeup); 93 94bool xsk_uses_need_wakeup(struct xsk_buff_pool *pool) 95{ 96 return pool->uses_need_wakeup; 97} 98EXPORT_SYMBOL(xsk_uses_need_wakeup); 99 100struct 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} 110EXPORT_SYMBOL(xsk_get_pool_from_qid); 111 112void 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 */ 124int 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 140static 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 157static 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) 171 goto err; 172 if (likely(!frags)) 173 return 0; 174 175 xskb_list = &xskb->pool->xskb_list; 176 list_for_each_entry_safe(pos, tmp, xskb_list, xskb_list_node) { 177 if (list_is_singular(xskb_list)) 178 contd = 0; 179 len = pos->xdp.data_end - pos->xdp.data; 180 err = __xsk_rcv_zc(xs, pos, len, contd); 181 if (err) 182 goto err; 183 list_del(&pos->xskb_list_node); 184 } 185 186 return 0; 187err: 188 xsk_buff_free(xdp); 189 return err; 190} 191 192static void *xsk_copy_xdp_start(struct xdp_buff *from) 193{ 194 if (unlikely(xdp_data_meta_unsupported(from))) 195 return from->data; 196 else 197 return from->data_meta; 198} 199 200static u32 xsk_copy_xdp(void *to, void **from, u32 to_len, 201 u32 *from_len, skb_frag_t **frag, u32 rem) 202{ 203 u32 copied = 0; 204 205 while (1) { 206 u32 copy_len = min_t(u32, *from_len, to_len); 207 208 memcpy(to, *from, copy_len); 209 copied += copy_len; 210 if (rem == copied) 211 return copied; 212 213 if (*from_len == copy_len) { 214 *from = skb_frag_address(*frag); 215 *from_len = skb_frag_size((*frag)++); 216 } else { 217 *from += copy_len; 218 *from_len -= copy_len; 219 } 220 if (to_len == copy_len) 221 return copied; 222 223 to_len -= copy_len; 224 to += copy_len; 225 } 226} 227 228static int __xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len) 229{ 230 u32 frame_size = xsk_pool_get_rx_frame_size(xs->pool); 231 void *copy_from = xsk_copy_xdp_start(xdp), *copy_to; 232 u32 from_len, meta_len, rem, num_desc; 233 struct xdp_buff_xsk *xskb; 234 struct xdp_buff *xsk_xdp; 235 skb_frag_t *frag; 236 237 from_len = xdp->data_end - copy_from; 238 meta_len = xdp->data - copy_from; 239 rem = len + meta_len; 240 241 if (len <= frame_size && !xdp_buff_has_frags(xdp)) { 242 int err; 243 244 xsk_xdp = xsk_buff_alloc(xs->pool); 245 if (!xsk_xdp) { 246 xs->rx_dropped++; 247 return -ENOMEM; 248 } 249 memcpy(xsk_xdp->data - meta_len, copy_from, rem); 250 xskb = container_of(xsk_xdp, struct xdp_buff_xsk, xdp); 251 err = __xsk_rcv_zc(xs, xskb, len, 0); 252 if (err) { 253 xsk_buff_free(xsk_xdp); 254 return err; 255 } 256 257 return 0; 258 } 259 260 num_desc = (len - 1) / frame_size + 1; 261 262 if (!xsk_buff_can_alloc(xs->pool, num_desc)) { 263 xs->rx_dropped++; 264 return -ENOMEM; 265 } 266 if (xskq_prod_nb_free(xs->rx, num_desc) < num_desc) { 267 xs->rx_queue_full++; 268 return -ENOBUFS; 269 } 270 271 if (xdp_buff_has_frags(xdp)) { 272 struct skb_shared_info *sinfo; 273 274 sinfo = xdp_get_shared_info_from_buff(xdp); 275 frag = &sinfo->frags[0]; 276 } 277 278 do { 279 u32 to_len = frame_size + meta_len; 280 u32 copied; 281 282 xsk_xdp = xsk_buff_alloc(xs->pool); 283 copy_to = xsk_xdp->data - meta_len; 284 285 copied = xsk_copy_xdp(copy_to, ©_from, to_len, &from_len, &frag, rem); 286 rem -= copied; 287 288 xskb = container_of(xsk_xdp, struct xdp_buff_xsk, xdp); 289 __xsk_rcv_zc(xs, xskb, copied - meta_len, rem ? XDP_PKT_CONTD : 0); 290 meta_len = 0; 291 } while (rem); 292 293 return 0; 294} 295 296static bool xsk_tx_writeable(struct xdp_sock *xs) 297{ 298 if (xskq_cons_present_entries(xs->tx) > xs->tx->nentries / 2) 299 return false; 300 301 return true; 302} 303 304static bool xsk_is_bound(struct xdp_sock *xs) 305{ 306 if (READ_ONCE(xs->state) == XSK_BOUND) { 307 /* Matches smp_wmb() in bind(). */ 308 smp_rmb(); 309 return true; 310 } 311 return false; 312} 313 314static int xsk_rcv_check(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len) 315{ 316 struct net_device *dev = xdp->rxq->dev; 317 u32 qid = xdp->rxq->queue_index; 318 319 if (!xsk_is_bound(xs)) 320 return -ENXIO; 321 322 if (!dev->_rx[qid].pool || xs->umem != dev->_rx[qid].pool->umem) 323 return -EINVAL; 324 325 if (len > xsk_pool_get_rx_frame_size(xs->pool) && !xs->sg) { 326 xs->rx_dropped++; 327 return -ENOSPC; 328 } 329 330 sk_mark_napi_id_once_xdp(&xs->sk, xdp); 331 return 0; 332} 333 334static void xsk_flush(struct xdp_sock *xs) 335{ 336 xskq_prod_submit(xs->rx); 337 __xskq_cons_release(xs->pool->fq); 338 sock_def_readable(&xs->sk); 339} 340 341int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp) 342{ 343 u32 len = xdp_get_buff_len(xdp); 344 int err; 345 346 spin_lock_bh(&xs->rx_lock); 347 err = xsk_rcv_check(xs, xdp, len); 348 if (!err) { 349 err = __xsk_rcv(xs, xdp, len); 350 xsk_flush(xs); 351 } 352 spin_unlock_bh(&xs->rx_lock); 353 return err; 354} 355 356static int xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp) 357{ 358 u32 len = xdp_get_buff_len(xdp); 359 int err; 360 361 err = xsk_rcv_check(xs, xdp, len); 362 if (err) 363 return err; 364 365 if (xdp->rxq->mem.type == MEM_TYPE_XSK_BUFF_POOL) { 366 len = xdp->data_end - xdp->data; 367 return xsk_rcv_zc(xs, xdp, len); 368 } 369 370 err = __xsk_rcv(xs, xdp, len); 371 if (!err) 372 xdp_return_buff(xdp); 373 return err; 374} 375 376int __xsk_map_redirect(struct xdp_sock *xs, struct xdp_buff *xdp) 377{ 378 struct list_head *flush_list = this_cpu_ptr(&xskmap_flush_list); 379 int err; 380 381 err = xsk_rcv(xs, xdp); 382 if (err) 383 return err; 384 385 if (!xs->flush_node.prev) 386 list_add(&xs->flush_node, flush_list); 387 388 return 0; 389} 390 391void __xsk_map_flush(void) 392{ 393 struct list_head *flush_list = this_cpu_ptr(&xskmap_flush_list); 394 struct xdp_sock *xs, *tmp; 395 396 list_for_each_entry_safe(xs, tmp, flush_list, flush_node) { 397 xsk_flush(xs); 398 __list_del_clearprev(&xs->flush_node); 399 } 400} 401 402#ifdef CONFIG_DEBUG_NET 403bool xsk_map_check_flush(void) 404{ 405 if (list_empty(this_cpu_ptr(&xskmap_flush_list))) 406 return false; 407 __xsk_map_flush(); 408 return true; 409} 410#endif 411 412void xsk_tx_completed(struct xsk_buff_pool *pool, u32 nb_entries) 413{ 414 xskq_prod_submit_n(pool->cq, nb_entries); 415} 416EXPORT_SYMBOL(xsk_tx_completed); 417 418void xsk_tx_release(struct xsk_buff_pool *pool) 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 __xskq_cons_release(xs->tx); 425 if (xsk_tx_writeable(xs)) 426 xs->sk.sk_write_space(&xs->sk); 427 } 428 rcu_read_unlock(); 429} 430EXPORT_SYMBOL(xsk_tx_release); 431 432bool xsk_tx_peek_desc(struct xsk_buff_pool *pool, struct xdp_desc *desc) 433{ 434 bool budget_exhausted = false; 435 struct xdp_sock *xs; 436 437 rcu_read_lock(); 438again: 439 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) { 440 if (xs->tx_budget_spent >= MAX_PER_SOCKET_BUDGET) { 441 budget_exhausted = true; 442 continue; 443 } 444 445 if (!xskq_cons_peek_desc(xs->tx, desc, pool)) { 446 if (xskq_has_descs(xs->tx)) 447 xskq_cons_release(xs->tx); 448 continue; 449 } 450 451 xs->tx_budget_spent++; 452 453 /* This is the backpressure mechanism for the Tx path. 454 * Reserve space in the completion queue and only proceed 455 * if there is space in it. This avoids having to implement 456 * any buffering in the Tx path. 457 */ 458 if (xskq_prod_reserve_addr(pool->cq, desc->addr)) 459 goto out; 460 461 xskq_cons_release(xs->tx); 462 rcu_read_unlock(); 463 return true; 464 } 465 466 if (budget_exhausted) { 467 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) 468 xs->tx_budget_spent = 0; 469 470 budget_exhausted = false; 471 goto again; 472 } 473 474out: 475 rcu_read_unlock(); 476 return false; 477} 478EXPORT_SYMBOL(xsk_tx_peek_desc); 479 480static u32 xsk_tx_peek_release_fallback(struct xsk_buff_pool *pool, u32 max_entries) 481{ 482 struct xdp_desc *descs = pool->tx_descs; 483 u32 nb_pkts = 0; 484 485 while (nb_pkts < max_entries && xsk_tx_peek_desc(pool, &descs[nb_pkts])) 486 nb_pkts++; 487 488 xsk_tx_release(pool); 489 return nb_pkts; 490} 491 492u32 xsk_tx_peek_release_desc_batch(struct xsk_buff_pool *pool, u32 nb_pkts) 493{ 494 struct xdp_sock *xs; 495 496 rcu_read_lock(); 497 if (!list_is_singular(&pool->xsk_tx_list)) { 498 /* Fallback to the non-batched version */ 499 rcu_read_unlock(); 500 return xsk_tx_peek_release_fallback(pool, nb_pkts); 501 } 502 503 xs = list_first_or_null_rcu(&pool->xsk_tx_list, struct xdp_sock, tx_list); 504 if (!xs) { 505 nb_pkts = 0; 506 goto out; 507 } 508 509 nb_pkts = xskq_cons_nb_entries(xs->tx, nb_pkts); 510 511 /* This is the backpressure mechanism for the Tx path. Try to 512 * reserve space in the completion queue for all packets, but 513 * if there are fewer slots available, just process that many 514 * packets. This avoids having to implement any buffering in 515 * the Tx path. 516 */ 517 nb_pkts = xskq_prod_nb_free(pool->cq, nb_pkts); 518 if (!nb_pkts) 519 goto out; 520 521 nb_pkts = xskq_cons_read_desc_batch(xs->tx, pool, nb_pkts); 522 if (!nb_pkts) { 523 xs->tx->queue_empty_descs++; 524 goto out; 525 } 526 527 __xskq_cons_release(xs->tx); 528 xskq_prod_write_addr_batch(pool->cq, pool->tx_descs, nb_pkts); 529 xs->sk.sk_write_space(&xs->sk); 530 531out: 532 rcu_read_unlock(); 533 return nb_pkts; 534} 535EXPORT_SYMBOL(xsk_tx_peek_release_desc_batch); 536 537static int xsk_wakeup(struct xdp_sock *xs, u8 flags) 538{ 539 struct net_device *dev = xs->dev; 540 541 return dev->netdev_ops->ndo_xsk_wakeup(dev, xs->queue_id, flags); 542} 543 544static int xsk_cq_reserve_addr_locked(struct xdp_sock *xs, u64 addr) 545{ 546 unsigned long flags; 547 int ret; 548 549 spin_lock_irqsave(&xs->pool->cq_lock, flags); 550 ret = xskq_prod_reserve_addr(xs->pool->cq, addr); 551 spin_unlock_irqrestore(&xs->pool->cq_lock, flags); 552 553 return ret; 554} 555 556static void xsk_cq_submit_locked(struct xdp_sock *xs, u32 n) 557{ 558 unsigned long flags; 559 560 spin_lock_irqsave(&xs->pool->cq_lock, flags); 561 xskq_prod_submit_n(xs->pool->cq, n); 562 spin_unlock_irqrestore(&xs->pool->cq_lock, flags); 563} 564 565static void xsk_cq_cancel_locked(struct xdp_sock *xs, u32 n) 566{ 567 unsigned long flags; 568 569 spin_lock_irqsave(&xs->pool->cq_lock, flags); 570 xskq_prod_cancel_n(xs->pool->cq, n); 571 spin_unlock_irqrestore(&xs->pool->cq_lock, flags); 572} 573 574static u32 xsk_get_num_desc(struct sk_buff *skb) 575{ 576 return skb ? (long)skb_shinfo(skb)->destructor_arg : 0; 577} 578 579static void xsk_destruct_skb(struct sk_buff *skb) 580{ 581 struct xsk_tx_metadata_compl *compl = &skb_shinfo(skb)->xsk_meta; 582 583 if (compl->tx_timestamp) { 584 /* sw completion timestamp, not a real one */ 585 *compl->tx_timestamp = ktime_get_tai_fast_ns(); 586 } 587 588 xsk_cq_submit_locked(xdp_sk(skb->sk), xsk_get_num_desc(skb)); 589 sock_wfree(skb); 590} 591 592static void xsk_set_destructor_arg(struct sk_buff *skb) 593{ 594 long num = xsk_get_num_desc(xdp_sk(skb->sk)->skb) + 1; 595 596 skb_shinfo(skb)->destructor_arg = (void *)num; 597} 598 599static void xsk_consume_skb(struct sk_buff *skb) 600{ 601 struct xdp_sock *xs = xdp_sk(skb->sk); 602 603 skb->destructor = sock_wfree; 604 xsk_cq_cancel_locked(xs, xsk_get_num_desc(skb)); 605 /* Free skb without triggering the perf drop trace */ 606 consume_skb(skb); 607 xs->skb = NULL; 608} 609 610static void xsk_drop_skb(struct sk_buff *skb) 611{ 612 xdp_sk(skb->sk)->tx->invalid_descs += xsk_get_num_desc(skb); 613 xsk_consume_skb(skb); 614} 615 616static struct sk_buff *xsk_build_skb_zerocopy(struct xdp_sock *xs, 617 struct xdp_desc *desc) 618{ 619 struct xsk_buff_pool *pool = xs->pool; 620 u32 hr, len, ts, offset, copy, copied; 621 struct sk_buff *skb = xs->skb; 622 struct page *page; 623 void *buffer; 624 int err, i; 625 u64 addr; 626 627 if (!skb) { 628 hr = max(NET_SKB_PAD, L1_CACHE_ALIGN(xs->dev->needed_headroom)); 629 630 skb = sock_alloc_send_skb(&xs->sk, hr, 1, &err); 631 if (unlikely(!skb)) 632 return ERR_PTR(err); 633 634 skb_reserve(skb, hr); 635 } 636 637 addr = desc->addr; 638 len = desc->len; 639 ts = pool->unaligned ? len : pool->chunk_size; 640 641 buffer = xsk_buff_raw_get_data(pool, addr); 642 offset = offset_in_page(buffer); 643 addr = buffer - pool->addrs; 644 645 for (copied = 0, i = skb_shinfo(skb)->nr_frags; copied < len; i++) { 646 if (unlikely(i >= MAX_SKB_FRAGS)) 647 return ERR_PTR(-EOVERFLOW); 648 649 page = pool->umem->pgs[addr >> PAGE_SHIFT]; 650 get_page(page); 651 652 copy = min_t(u32, PAGE_SIZE - offset, len - copied); 653 skb_fill_page_desc(skb, i, page, offset, copy); 654 655 copied += copy; 656 addr += copy; 657 offset = 0; 658 } 659 660 skb->len += len; 661 skb->data_len += len; 662 skb->truesize += ts; 663 664 refcount_add(ts, &xs->sk.sk_wmem_alloc); 665 666 return skb; 667} 668 669static struct sk_buff *xsk_build_skb(struct xdp_sock *xs, 670 struct xdp_desc *desc) 671{ 672 struct xsk_tx_metadata *meta = NULL; 673 struct net_device *dev = xs->dev; 674 struct sk_buff *skb = xs->skb; 675 bool first_frag = false; 676 int err; 677 678 if (dev->priv_flags & IFF_TX_SKB_NO_LINEAR) { 679 skb = xsk_build_skb_zerocopy(xs, desc); 680 if (IS_ERR(skb)) { 681 err = PTR_ERR(skb); 682 goto free_err; 683 } 684 } else { 685 u32 hr, tr, len; 686 void *buffer; 687 688 buffer = xsk_buff_raw_get_data(xs->pool, desc->addr); 689 len = desc->len; 690 691 if (!skb) { 692 hr = max(NET_SKB_PAD, L1_CACHE_ALIGN(dev->needed_headroom)); 693 tr = dev->needed_tailroom; 694 skb = sock_alloc_send_skb(&xs->sk, hr + len + tr, 1, &err); 695 if (unlikely(!skb)) 696 goto free_err; 697 698 skb_reserve(skb, hr); 699 skb_put(skb, len); 700 701 err = skb_store_bits(skb, 0, buffer, len); 702 if (unlikely(err)) { 703 kfree_skb(skb); 704 goto free_err; 705 } 706 707 first_frag = true; 708 } else { 709 int nr_frags = skb_shinfo(skb)->nr_frags; 710 struct page *page; 711 u8 *vaddr; 712 713 if (unlikely(nr_frags == (MAX_SKB_FRAGS - 1) && xp_mb_desc(desc))) { 714 err = -EOVERFLOW; 715 goto free_err; 716 } 717 718 page = alloc_page(xs->sk.sk_allocation); 719 if (unlikely(!page)) { 720 err = -EAGAIN; 721 goto free_err; 722 } 723 724 vaddr = kmap_local_page(page); 725 memcpy(vaddr, buffer, len); 726 kunmap_local(vaddr); 727 728 skb_add_rx_frag(skb, nr_frags, page, 0, len, PAGE_SIZE); 729 refcount_add(PAGE_SIZE, &xs->sk.sk_wmem_alloc); 730 } 731 732 if (first_frag && desc->options & XDP_TX_METADATA) { 733 if (unlikely(xs->pool->tx_metadata_len == 0)) { 734 err = -EINVAL; 735 goto free_err; 736 } 737 738 meta = buffer - xs->pool->tx_metadata_len; 739 if (unlikely(!xsk_buff_valid_tx_metadata(meta))) { 740 err = -EINVAL; 741 goto free_err; 742 } 743 744 if (meta->flags & XDP_TXMD_FLAGS_CHECKSUM) { 745 if (unlikely(meta->request.csum_start + 746 meta->request.csum_offset + 747 sizeof(__sum16) > len)) { 748 err = -EINVAL; 749 goto free_err; 750 } 751 752 skb->csum_start = hr + meta->request.csum_start; 753 skb->csum_offset = meta->request.csum_offset; 754 skb->ip_summed = CHECKSUM_PARTIAL; 755 756 if (unlikely(xs->pool->tx_sw_csum)) { 757 err = skb_checksum_help(skb); 758 if (err) 759 goto free_err; 760 } 761 } 762 } 763 } 764 765 skb->dev = dev; 766 skb->priority = READ_ONCE(xs->sk.sk_priority); 767 skb->mark = READ_ONCE(xs->sk.sk_mark); 768 skb->destructor = xsk_destruct_skb; 769 xsk_tx_metadata_to_compl(meta, &skb_shinfo(skb)->xsk_meta); 770 xsk_set_destructor_arg(skb); 771 772 return skb; 773 774free_err: 775 if (err == -EOVERFLOW) { 776 /* Drop the packet */ 777 xsk_set_destructor_arg(xs->skb); 778 xsk_drop_skb(xs->skb); 779 xskq_cons_release(xs->tx); 780 } else { 781 /* Let application retry */ 782 xsk_cq_cancel_locked(xs, 1); 783 } 784 785 return ERR_PTR(err); 786} 787 788static int __xsk_generic_xmit(struct sock *sk) 789{ 790 struct xdp_sock *xs = xdp_sk(sk); 791 u32 max_batch = TX_BATCH_SIZE; 792 bool sent_frame = false; 793 struct xdp_desc desc; 794 struct sk_buff *skb; 795 int err = 0; 796 797 mutex_lock(&xs->mutex); 798 799 /* Since we dropped the RCU read lock, the socket state might have changed. */ 800 if (unlikely(!xsk_is_bound(xs))) { 801 err = -ENXIO; 802 goto out; 803 } 804 805 if (xs->queue_id >= xs->dev->real_num_tx_queues) 806 goto out; 807 808 while (xskq_cons_peek_desc(xs->tx, &desc, xs->pool)) { 809 if (max_batch-- == 0) { 810 err = -EAGAIN; 811 goto out; 812 } 813 814 /* This is the backpressure mechanism for the Tx path. 815 * Reserve space in the completion queue and only proceed 816 * if there is space in it. This avoids having to implement 817 * any buffering in the Tx path. 818 */ 819 if (xsk_cq_reserve_addr_locked(xs, desc.addr)) 820 goto out; 821 822 skb = xsk_build_skb(xs, &desc); 823 if (IS_ERR(skb)) { 824 err = PTR_ERR(skb); 825 if (err != -EOVERFLOW) 826 goto out; 827 err = 0; 828 continue; 829 } 830 831 xskq_cons_release(xs->tx); 832 833 if (xp_mb_desc(&desc)) { 834 xs->skb = skb; 835 continue; 836 } 837 838 err = __dev_direct_xmit(skb, xs->queue_id); 839 if (err == NETDEV_TX_BUSY) { 840 /* Tell user-space to retry the send */ 841 xskq_cons_cancel_n(xs->tx, xsk_get_num_desc(skb)); 842 xsk_consume_skb(skb); 843 err = -EAGAIN; 844 goto out; 845 } 846 847 /* Ignore NET_XMIT_CN as packet might have been sent */ 848 if (err == NET_XMIT_DROP) { 849 /* SKB completed but not sent */ 850 err = -EBUSY; 851 xs->skb = NULL; 852 goto out; 853 } 854 855 sent_frame = true; 856 xs->skb = NULL; 857 } 858 859 if (xskq_has_descs(xs->tx)) { 860 if (xs->skb) 861 xsk_drop_skb(xs->skb); 862 xskq_cons_release(xs->tx); 863 } 864 865out: 866 if (sent_frame) 867 if (xsk_tx_writeable(xs)) 868 sk->sk_write_space(sk); 869 870 mutex_unlock(&xs->mutex); 871 return err; 872} 873 874static int xsk_generic_xmit(struct sock *sk) 875{ 876 int ret; 877 878 /* Drop the RCU lock since the SKB path might sleep. */ 879 rcu_read_unlock(); 880 ret = __xsk_generic_xmit(sk); 881 /* Reaquire RCU lock before going into common code. */ 882 rcu_read_lock(); 883 884 return ret; 885} 886 887static bool xsk_no_wakeup(struct sock *sk) 888{ 889#ifdef CONFIG_NET_RX_BUSY_POLL 890 /* Prefer busy-polling, skip the wakeup. */ 891 return READ_ONCE(sk->sk_prefer_busy_poll) && READ_ONCE(sk->sk_ll_usec) && 892 READ_ONCE(sk->sk_napi_id) >= MIN_NAPI_ID; 893#else 894 return false; 895#endif 896} 897 898static int xsk_check_common(struct xdp_sock *xs) 899{ 900 if (unlikely(!xsk_is_bound(xs))) 901 return -ENXIO; 902 if (unlikely(!(xs->dev->flags & IFF_UP))) 903 return -ENETDOWN; 904 905 return 0; 906} 907 908static int __xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len) 909{ 910 bool need_wait = !(m->msg_flags & MSG_DONTWAIT); 911 struct sock *sk = sock->sk; 912 struct xdp_sock *xs = xdp_sk(sk); 913 struct xsk_buff_pool *pool; 914 int err; 915 916 err = xsk_check_common(xs); 917 if (err) 918 return err; 919 if (unlikely(need_wait)) 920 return -EOPNOTSUPP; 921 if (unlikely(!xs->tx)) 922 return -ENOBUFS; 923 924 if (sk_can_busy_loop(sk)) { 925 if (xs->zc) 926 __sk_mark_napi_id_once(sk, xsk_pool_get_napi_id(xs->pool)); 927 sk_busy_loop(sk, 1); /* only support non-blocking sockets */ 928 } 929 930 if (xs->zc && xsk_no_wakeup(sk)) 931 return 0; 932 933 pool = xs->pool; 934 if (pool->cached_need_wakeup & XDP_WAKEUP_TX) { 935 if (xs->zc) 936 return xsk_wakeup(xs, XDP_WAKEUP_TX); 937 return xsk_generic_xmit(sk); 938 } 939 return 0; 940} 941 942static int xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len) 943{ 944 int ret; 945 946 rcu_read_lock(); 947 ret = __xsk_sendmsg(sock, m, total_len); 948 rcu_read_unlock(); 949 950 return ret; 951} 952 953static int __xsk_recvmsg(struct socket *sock, struct msghdr *m, size_t len, int flags) 954{ 955 bool need_wait = !(flags & MSG_DONTWAIT); 956 struct sock *sk = sock->sk; 957 struct xdp_sock *xs = xdp_sk(sk); 958 int err; 959 960 err = xsk_check_common(xs); 961 if (err) 962 return err; 963 if (unlikely(!xs->rx)) 964 return -ENOBUFS; 965 if (unlikely(need_wait)) 966 return -EOPNOTSUPP; 967 968 if (sk_can_busy_loop(sk)) 969 sk_busy_loop(sk, 1); /* only support non-blocking sockets */ 970 971 if (xsk_no_wakeup(sk)) 972 return 0; 973 974 if (xs->pool->cached_need_wakeup & XDP_WAKEUP_RX && xs->zc) 975 return xsk_wakeup(xs, XDP_WAKEUP_RX); 976 return 0; 977} 978 979static int xsk_recvmsg(struct socket *sock, struct msghdr *m, size_t len, int flags) 980{ 981 int ret; 982 983 rcu_read_lock(); 984 ret = __xsk_recvmsg(sock, m, len, flags); 985 rcu_read_unlock(); 986 987 return ret; 988} 989 990static __poll_t xsk_poll(struct file *file, struct socket *sock, 991 struct poll_table_struct *wait) 992{ 993 __poll_t mask = 0; 994 struct sock *sk = sock->sk; 995 struct xdp_sock *xs = xdp_sk(sk); 996 struct xsk_buff_pool *pool; 997 998 sock_poll_wait(file, sock, wait); 999 1000 rcu_read_lock(); 1001 if (xsk_check_common(xs)) 1002 goto out; 1003 1004 pool = xs->pool; 1005 1006 if (pool->cached_need_wakeup) { 1007 if (xs->zc) 1008 xsk_wakeup(xs, pool->cached_need_wakeup); 1009 else if (xs->tx) 1010 /* Poll needs to drive Tx also in copy mode */ 1011 xsk_generic_xmit(sk); 1012 } 1013 1014 if (xs->rx && !xskq_prod_is_empty(xs->rx)) 1015 mask |= EPOLLIN | EPOLLRDNORM; 1016 if (xs->tx && xsk_tx_writeable(xs)) 1017 mask |= EPOLLOUT | EPOLLWRNORM; 1018out: 1019 rcu_read_unlock(); 1020 return mask; 1021} 1022 1023static int xsk_init_queue(u32 entries, struct xsk_queue **queue, 1024 bool umem_queue) 1025{ 1026 struct xsk_queue *q; 1027 1028 if (entries == 0 || *queue || !is_power_of_2(entries)) 1029 return -EINVAL; 1030 1031 q = xskq_create(entries, umem_queue); 1032 if (!q) 1033 return -ENOMEM; 1034 1035 /* Make sure queue is ready before it can be seen by others */ 1036 smp_wmb(); 1037 WRITE_ONCE(*queue, q); 1038 return 0; 1039} 1040 1041static void xsk_unbind_dev(struct xdp_sock *xs) 1042{ 1043 struct net_device *dev = xs->dev; 1044 1045 if (xs->state != XSK_BOUND) 1046 return; 1047 WRITE_ONCE(xs->state, XSK_UNBOUND); 1048 1049 /* Wait for driver to stop using the xdp socket. */ 1050 xp_del_xsk(xs->pool, xs); 1051 synchronize_net(); 1052 dev_put(dev); 1053} 1054 1055static struct xsk_map *xsk_get_map_list_entry(struct xdp_sock *xs, 1056 struct xdp_sock __rcu ***map_entry) 1057{ 1058 struct xsk_map *map = NULL; 1059 struct xsk_map_node *node; 1060 1061 *map_entry = NULL; 1062 1063 spin_lock_bh(&xs->map_list_lock); 1064 node = list_first_entry_or_null(&xs->map_list, struct xsk_map_node, 1065 node); 1066 if (node) { 1067 bpf_map_inc(&node->map->map); 1068 map = node->map; 1069 *map_entry = node->map_entry; 1070 } 1071 spin_unlock_bh(&xs->map_list_lock); 1072 return map; 1073} 1074 1075static void xsk_delete_from_maps(struct xdp_sock *xs) 1076{ 1077 /* This function removes the current XDP socket from all the 1078 * maps it resides in. We need to take extra care here, due to 1079 * the two locks involved. Each map has a lock synchronizing 1080 * updates to the entries, and each socket has a lock that 1081 * synchronizes access to the list of maps (map_list). For 1082 * deadlock avoidance the locks need to be taken in the order 1083 * "map lock"->"socket map list lock". We start off by 1084 * accessing the socket map list, and take a reference to the 1085 * map to guarantee existence between the 1086 * xsk_get_map_list_entry() and xsk_map_try_sock_delete() 1087 * calls. Then we ask the map to remove the socket, which 1088 * tries to remove the socket from the map. Note that there 1089 * might be updates to the map between 1090 * xsk_get_map_list_entry() and xsk_map_try_sock_delete(). 1091 */ 1092 struct xdp_sock __rcu **map_entry = NULL; 1093 struct xsk_map *map; 1094 1095 while ((map = xsk_get_map_list_entry(xs, &map_entry))) { 1096 xsk_map_try_sock_delete(map, xs, map_entry); 1097 bpf_map_put(&map->map); 1098 } 1099} 1100 1101static int xsk_release(struct socket *sock) 1102{ 1103 struct sock *sk = sock->sk; 1104 struct xdp_sock *xs = xdp_sk(sk); 1105 struct net *net; 1106 1107 if (!sk) 1108 return 0; 1109 1110 net = sock_net(sk); 1111 1112 if (xs->skb) 1113 xsk_drop_skb(xs->skb); 1114 1115 mutex_lock(&net->xdp.lock); 1116 sk_del_node_init_rcu(sk); 1117 mutex_unlock(&net->xdp.lock); 1118 1119 sock_prot_inuse_add(net, sk->sk_prot, -1); 1120 1121 xsk_delete_from_maps(xs); 1122 mutex_lock(&xs->mutex); 1123 xsk_unbind_dev(xs); 1124 mutex_unlock(&xs->mutex); 1125 1126 xskq_destroy(xs->rx); 1127 xskq_destroy(xs->tx); 1128 xskq_destroy(xs->fq_tmp); 1129 xskq_destroy(xs->cq_tmp); 1130 1131 sock_orphan(sk); 1132 sock->sk = NULL; 1133 1134 sock_put(sk); 1135 1136 return 0; 1137} 1138 1139static struct socket *xsk_lookup_xsk_from_fd(int fd) 1140{ 1141 struct socket *sock; 1142 int err; 1143 1144 sock = sockfd_lookup(fd, &err); 1145 if (!sock) 1146 return ERR_PTR(-ENOTSOCK); 1147 1148 if (sock->sk->sk_family != PF_XDP) { 1149 sockfd_put(sock); 1150 return ERR_PTR(-ENOPROTOOPT); 1151 } 1152 1153 return sock; 1154} 1155 1156static bool xsk_validate_queues(struct xdp_sock *xs) 1157{ 1158 return xs->fq_tmp && xs->cq_tmp; 1159} 1160 1161static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len) 1162{ 1163 struct sockaddr_xdp *sxdp = (struct sockaddr_xdp *)addr; 1164 struct sock *sk = sock->sk; 1165 struct xdp_sock *xs = xdp_sk(sk); 1166 struct net_device *dev; 1167 int bound_dev_if; 1168 u32 flags, qid; 1169 int err = 0; 1170 1171 if (addr_len < sizeof(struct sockaddr_xdp)) 1172 return -EINVAL; 1173 if (sxdp->sxdp_family != AF_XDP) 1174 return -EINVAL; 1175 1176 flags = sxdp->sxdp_flags; 1177 if (flags & ~(XDP_SHARED_UMEM | XDP_COPY | XDP_ZEROCOPY | 1178 XDP_USE_NEED_WAKEUP | XDP_USE_SG)) 1179 return -EINVAL; 1180 1181 bound_dev_if = READ_ONCE(sk->sk_bound_dev_if); 1182 if (bound_dev_if && bound_dev_if != sxdp->sxdp_ifindex) 1183 return -EINVAL; 1184 1185 rtnl_lock(); 1186 mutex_lock(&xs->mutex); 1187 if (xs->state != XSK_READY) { 1188 err = -EBUSY; 1189 goto out_release; 1190 } 1191 1192 dev = dev_get_by_index(sock_net(sk), sxdp->sxdp_ifindex); 1193 if (!dev) { 1194 err = -ENODEV; 1195 goto out_release; 1196 } 1197 1198 if (!xs->rx && !xs->tx) { 1199 err = -EINVAL; 1200 goto out_unlock; 1201 } 1202 1203 qid = sxdp->sxdp_queue_id; 1204 1205 if (flags & XDP_SHARED_UMEM) { 1206 struct xdp_sock *umem_xs; 1207 struct socket *sock; 1208 1209 if ((flags & XDP_COPY) || (flags & XDP_ZEROCOPY) || 1210 (flags & XDP_USE_NEED_WAKEUP) || (flags & XDP_USE_SG)) { 1211 /* Cannot specify flags for shared sockets. */ 1212 err = -EINVAL; 1213 goto out_unlock; 1214 } 1215 1216 if (xs->umem) { 1217 /* We have already our own. */ 1218 err = -EINVAL; 1219 goto out_unlock; 1220 } 1221 1222 sock = xsk_lookup_xsk_from_fd(sxdp->sxdp_shared_umem_fd); 1223 if (IS_ERR(sock)) { 1224 err = PTR_ERR(sock); 1225 goto out_unlock; 1226 } 1227 1228 umem_xs = xdp_sk(sock->sk); 1229 if (!xsk_is_bound(umem_xs)) { 1230 err = -EBADF; 1231 sockfd_put(sock); 1232 goto out_unlock; 1233 } 1234 1235 if (umem_xs->queue_id != qid || umem_xs->dev != dev) { 1236 /* Share the umem with another socket on another qid 1237 * and/or device. 1238 */ 1239 xs->pool = xp_create_and_assign_umem(xs, 1240 umem_xs->umem); 1241 if (!xs->pool) { 1242 err = -ENOMEM; 1243 sockfd_put(sock); 1244 goto out_unlock; 1245 } 1246 1247 err = xp_assign_dev_shared(xs->pool, umem_xs, dev, 1248 qid); 1249 if (err) { 1250 xp_destroy(xs->pool); 1251 xs->pool = NULL; 1252 sockfd_put(sock); 1253 goto out_unlock; 1254 } 1255 } else { 1256 /* Share the buffer pool with the other socket. */ 1257 if (xs->fq_tmp || xs->cq_tmp) { 1258 /* Do not allow setting your own fq or cq. */ 1259 err = -EINVAL; 1260 sockfd_put(sock); 1261 goto out_unlock; 1262 } 1263 1264 xp_get_pool(umem_xs->pool); 1265 xs->pool = umem_xs->pool; 1266 1267 /* If underlying shared umem was created without Tx 1268 * ring, allocate Tx descs array that Tx batching API 1269 * utilizes 1270 */ 1271 if (xs->tx && !xs->pool->tx_descs) { 1272 err = xp_alloc_tx_descs(xs->pool, xs); 1273 if (err) { 1274 xp_put_pool(xs->pool); 1275 xs->pool = NULL; 1276 sockfd_put(sock); 1277 goto out_unlock; 1278 } 1279 } 1280 } 1281 1282 xdp_get_umem(umem_xs->umem); 1283 WRITE_ONCE(xs->umem, umem_xs->umem); 1284 sockfd_put(sock); 1285 } else if (!xs->umem || !xsk_validate_queues(xs)) { 1286 err = -EINVAL; 1287 goto out_unlock; 1288 } else { 1289 /* This xsk has its own umem. */ 1290 xs->pool = xp_create_and_assign_umem(xs, xs->umem); 1291 if (!xs->pool) { 1292 err = -ENOMEM; 1293 goto out_unlock; 1294 } 1295 1296 err = xp_assign_dev(xs->pool, dev, qid, flags); 1297 if (err) { 1298 xp_destroy(xs->pool); 1299 xs->pool = NULL; 1300 goto out_unlock; 1301 } 1302 } 1303 1304 /* FQ and CQ are now owned by the buffer pool and cleaned up with it. */ 1305 xs->fq_tmp = NULL; 1306 xs->cq_tmp = NULL; 1307 1308 xs->dev = dev; 1309 xs->zc = xs->umem->zc; 1310 xs->sg = !!(xs->umem->flags & XDP_UMEM_SG_FLAG); 1311 xs->queue_id = qid; 1312 xp_add_xsk(xs->pool, xs); 1313 1314out_unlock: 1315 if (err) { 1316 dev_put(dev); 1317 } else { 1318 /* Matches smp_rmb() in bind() for shared umem 1319 * sockets, and xsk_is_bound(). 1320 */ 1321 smp_wmb(); 1322 WRITE_ONCE(xs->state, XSK_BOUND); 1323 } 1324out_release: 1325 mutex_unlock(&xs->mutex); 1326 rtnl_unlock(); 1327 return err; 1328} 1329 1330struct xdp_umem_reg_v1 { 1331 __u64 addr; /* Start of packet data area */ 1332 __u64 len; /* Length of packet data area */ 1333 __u32 chunk_size; 1334 __u32 headroom; 1335}; 1336 1337struct xdp_umem_reg_v2 { 1338 __u64 addr; /* Start of packet data area */ 1339 __u64 len; /* Length of packet data area */ 1340 __u32 chunk_size; 1341 __u32 headroom; 1342 __u32 flags; 1343}; 1344 1345static int xsk_setsockopt(struct socket *sock, int level, int optname, 1346 sockptr_t optval, unsigned int optlen) 1347{ 1348 struct sock *sk = sock->sk; 1349 struct xdp_sock *xs = xdp_sk(sk); 1350 int err; 1351 1352 if (level != SOL_XDP) 1353 return -ENOPROTOOPT; 1354 1355 switch (optname) { 1356 case XDP_RX_RING: 1357 case XDP_TX_RING: 1358 { 1359 struct xsk_queue **q; 1360 int entries; 1361 1362 if (optlen < sizeof(entries)) 1363 return -EINVAL; 1364 if (copy_from_sockptr(&entries, optval, sizeof(entries))) 1365 return -EFAULT; 1366 1367 mutex_lock(&xs->mutex); 1368 if (xs->state != XSK_READY) { 1369 mutex_unlock(&xs->mutex); 1370 return -EBUSY; 1371 } 1372 q = (optname == XDP_TX_RING) ? &xs->tx : &xs->rx; 1373 err = xsk_init_queue(entries, q, false); 1374 if (!err && optname == XDP_TX_RING) 1375 /* Tx needs to be explicitly woken up the first time */ 1376 xs->tx->ring->flags |= XDP_RING_NEED_WAKEUP; 1377 mutex_unlock(&xs->mutex); 1378 return err; 1379 } 1380 case XDP_UMEM_REG: 1381 { 1382 size_t mr_size = sizeof(struct xdp_umem_reg); 1383 struct xdp_umem_reg mr = {}; 1384 struct xdp_umem *umem; 1385 1386 if (optlen < sizeof(struct xdp_umem_reg_v1)) 1387 return -EINVAL; 1388 else if (optlen < sizeof(struct xdp_umem_reg_v2)) 1389 mr_size = sizeof(struct xdp_umem_reg_v1); 1390 else if (optlen < sizeof(mr)) 1391 mr_size = sizeof(struct xdp_umem_reg_v2); 1392 1393 if (copy_from_sockptr(&mr, optval, mr_size)) 1394 return -EFAULT; 1395 1396 mutex_lock(&xs->mutex); 1397 if (xs->state != XSK_READY || xs->umem) { 1398 mutex_unlock(&xs->mutex); 1399 return -EBUSY; 1400 } 1401 1402 umem = xdp_umem_create(&mr); 1403 if (IS_ERR(umem)) { 1404 mutex_unlock(&xs->mutex); 1405 return PTR_ERR(umem); 1406 } 1407 1408 /* Make sure umem is ready before it can be seen by others */ 1409 smp_wmb(); 1410 WRITE_ONCE(xs->umem, umem); 1411 mutex_unlock(&xs->mutex); 1412 return 0; 1413 } 1414 case XDP_UMEM_FILL_RING: 1415 case XDP_UMEM_COMPLETION_RING: 1416 { 1417 struct xsk_queue **q; 1418 int entries; 1419 1420 if (optlen < sizeof(entries)) 1421 return -EINVAL; 1422 if (copy_from_sockptr(&entries, optval, sizeof(entries))) 1423 return -EFAULT; 1424 1425 mutex_lock(&xs->mutex); 1426 if (xs->state != XSK_READY) { 1427 mutex_unlock(&xs->mutex); 1428 return -EBUSY; 1429 } 1430 1431 q = (optname == XDP_UMEM_FILL_RING) ? &xs->fq_tmp : 1432 &xs->cq_tmp; 1433 err = xsk_init_queue(entries, q, true); 1434 mutex_unlock(&xs->mutex); 1435 return err; 1436 } 1437 default: 1438 break; 1439 } 1440 1441 return -ENOPROTOOPT; 1442} 1443 1444static void xsk_enter_rxtx_offsets(struct xdp_ring_offset_v1 *ring) 1445{ 1446 ring->producer = offsetof(struct xdp_rxtx_ring, ptrs.producer); 1447 ring->consumer = offsetof(struct xdp_rxtx_ring, ptrs.consumer); 1448 ring->desc = offsetof(struct xdp_rxtx_ring, desc); 1449} 1450 1451static void xsk_enter_umem_offsets(struct xdp_ring_offset_v1 *ring) 1452{ 1453 ring->producer = offsetof(struct xdp_umem_ring, ptrs.producer); 1454 ring->consumer = offsetof(struct xdp_umem_ring, ptrs.consumer); 1455 ring->desc = offsetof(struct xdp_umem_ring, desc); 1456} 1457 1458struct xdp_statistics_v1 { 1459 __u64 rx_dropped; 1460 __u64 rx_invalid_descs; 1461 __u64 tx_invalid_descs; 1462}; 1463 1464static int xsk_getsockopt(struct socket *sock, int level, int optname, 1465 char __user *optval, int __user *optlen) 1466{ 1467 struct sock *sk = sock->sk; 1468 struct xdp_sock *xs = xdp_sk(sk); 1469 int len; 1470 1471 if (level != SOL_XDP) 1472 return -ENOPROTOOPT; 1473 1474 if (get_user(len, optlen)) 1475 return -EFAULT; 1476 if (len < 0) 1477 return -EINVAL; 1478 1479 switch (optname) { 1480 case XDP_STATISTICS: 1481 { 1482 struct xdp_statistics stats = {}; 1483 bool extra_stats = true; 1484 size_t stats_size; 1485 1486 if (len < sizeof(struct xdp_statistics_v1)) { 1487 return -EINVAL; 1488 } else if (len < sizeof(stats)) { 1489 extra_stats = false; 1490 stats_size = sizeof(struct xdp_statistics_v1); 1491 } else { 1492 stats_size = sizeof(stats); 1493 } 1494 1495 mutex_lock(&xs->mutex); 1496 stats.rx_dropped = xs->rx_dropped; 1497 if (extra_stats) { 1498 stats.rx_ring_full = xs->rx_queue_full; 1499 stats.rx_fill_ring_empty_descs = 1500 xs->pool ? xskq_nb_queue_empty_descs(xs->pool->fq) : 0; 1501 stats.tx_ring_empty_descs = xskq_nb_queue_empty_descs(xs->tx); 1502 } else { 1503 stats.rx_dropped += xs->rx_queue_full; 1504 } 1505 stats.rx_invalid_descs = xskq_nb_invalid_descs(xs->rx); 1506 stats.tx_invalid_descs = xskq_nb_invalid_descs(xs->tx); 1507 mutex_unlock(&xs->mutex); 1508 1509 if (copy_to_user(optval, &stats, stats_size)) 1510 return -EFAULT; 1511 if (put_user(stats_size, optlen)) 1512 return -EFAULT; 1513 1514 return 0; 1515 } 1516 case XDP_MMAP_OFFSETS: 1517 { 1518 struct xdp_mmap_offsets off; 1519 struct xdp_mmap_offsets_v1 off_v1; 1520 bool flags_supported = true; 1521 void *to_copy; 1522 1523 if (len < sizeof(off_v1)) 1524 return -EINVAL; 1525 else if (len < sizeof(off)) 1526 flags_supported = false; 1527 1528 if (flags_supported) { 1529 /* xdp_ring_offset is identical to xdp_ring_offset_v1 1530 * except for the flags field added to the end. 1531 */ 1532 xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *) 1533 &off.rx); 1534 xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *) 1535 &off.tx); 1536 xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *) 1537 &off.fr); 1538 xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *) 1539 &off.cr); 1540 off.rx.flags = offsetof(struct xdp_rxtx_ring, 1541 ptrs.flags); 1542 off.tx.flags = offsetof(struct xdp_rxtx_ring, 1543 ptrs.flags); 1544 off.fr.flags = offsetof(struct xdp_umem_ring, 1545 ptrs.flags); 1546 off.cr.flags = offsetof(struct xdp_umem_ring, 1547 ptrs.flags); 1548 1549 len = sizeof(off); 1550 to_copy = &off; 1551 } else { 1552 xsk_enter_rxtx_offsets(&off_v1.rx); 1553 xsk_enter_rxtx_offsets(&off_v1.tx); 1554 xsk_enter_umem_offsets(&off_v1.fr); 1555 xsk_enter_umem_offsets(&off_v1.cr); 1556 1557 len = sizeof(off_v1); 1558 to_copy = &off_v1; 1559 } 1560 1561 if (copy_to_user(optval, to_copy, len)) 1562 return -EFAULT; 1563 if (put_user(len, optlen)) 1564 return -EFAULT; 1565 1566 return 0; 1567 } 1568 case XDP_OPTIONS: 1569 { 1570 struct xdp_options opts = {}; 1571 1572 if (len < sizeof(opts)) 1573 return -EINVAL; 1574 1575 mutex_lock(&xs->mutex); 1576 if (xs->zc) 1577 opts.flags |= XDP_OPTIONS_ZEROCOPY; 1578 mutex_unlock(&xs->mutex); 1579 1580 len = sizeof(opts); 1581 if (copy_to_user(optval, &opts, len)) 1582 return -EFAULT; 1583 if (put_user(len, optlen)) 1584 return -EFAULT; 1585 1586 return 0; 1587 } 1588 default: 1589 break; 1590 } 1591 1592 return -EOPNOTSUPP; 1593} 1594 1595static int xsk_mmap(struct file *file, struct socket *sock, 1596 struct vm_area_struct *vma) 1597{ 1598 loff_t offset = (loff_t)vma->vm_pgoff << PAGE_SHIFT; 1599 unsigned long size = vma->vm_end - vma->vm_start; 1600 struct xdp_sock *xs = xdp_sk(sock->sk); 1601 int state = READ_ONCE(xs->state); 1602 struct xsk_queue *q = NULL; 1603 1604 if (state != XSK_READY && state != XSK_BOUND) 1605 return -EBUSY; 1606 1607 if (offset == XDP_PGOFF_RX_RING) { 1608 q = READ_ONCE(xs->rx); 1609 } else if (offset == XDP_PGOFF_TX_RING) { 1610 q = READ_ONCE(xs->tx); 1611 } else { 1612 /* Matches the smp_wmb() in XDP_UMEM_REG */ 1613 smp_rmb(); 1614 if (offset == XDP_UMEM_PGOFF_FILL_RING) 1615 q = state == XSK_READY ? READ_ONCE(xs->fq_tmp) : 1616 READ_ONCE(xs->pool->fq); 1617 else if (offset == XDP_UMEM_PGOFF_COMPLETION_RING) 1618 q = state == XSK_READY ? READ_ONCE(xs->cq_tmp) : 1619 READ_ONCE(xs->pool->cq); 1620 } 1621 1622 if (!q) 1623 return -EINVAL; 1624 1625 /* Matches the smp_wmb() in xsk_init_queue */ 1626 smp_rmb(); 1627 if (size > q->ring_vmalloc_size) 1628 return -EINVAL; 1629 1630 return remap_vmalloc_range(vma, q->ring, 0); 1631} 1632 1633static int xsk_notifier(struct notifier_block *this, 1634 unsigned long msg, void *ptr) 1635{ 1636 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1637 struct net *net = dev_net(dev); 1638 struct sock *sk; 1639 1640 switch (msg) { 1641 case NETDEV_UNREGISTER: 1642 mutex_lock(&net->xdp.lock); 1643 sk_for_each(sk, &net->xdp.list) { 1644 struct xdp_sock *xs = xdp_sk(sk); 1645 1646 mutex_lock(&xs->mutex); 1647 if (xs->dev == dev) { 1648 sk->sk_err = ENETDOWN; 1649 if (!sock_flag(sk, SOCK_DEAD)) 1650 sk_error_report(sk); 1651 1652 xsk_unbind_dev(xs); 1653 1654 /* Clear device references. */ 1655 xp_clear_dev(xs->pool); 1656 } 1657 mutex_unlock(&xs->mutex); 1658 } 1659 mutex_unlock(&net->xdp.lock); 1660 break; 1661 } 1662 return NOTIFY_DONE; 1663} 1664 1665static struct proto xsk_proto = { 1666 .name = "XDP", 1667 .owner = THIS_MODULE, 1668 .obj_size = sizeof(struct xdp_sock), 1669}; 1670 1671static const struct proto_ops xsk_proto_ops = { 1672 .family = PF_XDP, 1673 .owner = THIS_MODULE, 1674 .release = xsk_release, 1675 .bind = xsk_bind, 1676 .connect = sock_no_connect, 1677 .socketpair = sock_no_socketpair, 1678 .accept = sock_no_accept, 1679 .getname = sock_no_getname, 1680 .poll = xsk_poll, 1681 .ioctl = sock_no_ioctl, 1682 .listen = sock_no_listen, 1683 .shutdown = sock_no_shutdown, 1684 .setsockopt = xsk_setsockopt, 1685 .getsockopt = xsk_getsockopt, 1686 .sendmsg = xsk_sendmsg, 1687 .recvmsg = xsk_recvmsg, 1688 .mmap = xsk_mmap, 1689}; 1690 1691static void xsk_destruct(struct sock *sk) 1692{ 1693 struct xdp_sock *xs = xdp_sk(sk); 1694 1695 if (!sock_flag(sk, SOCK_DEAD)) 1696 return; 1697 1698 if (!xp_put_pool(xs->pool)) 1699 xdp_put_umem(xs->umem, !xs->pool); 1700} 1701 1702static int xsk_create(struct net *net, struct socket *sock, int protocol, 1703 int kern) 1704{ 1705 struct xdp_sock *xs; 1706 struct sock *sk; 1707 1708 if (!ns_capable(net->user_ns, CAP_NET_RAW)) 1709 return -EPERM; 1710 if (sock->type != SOCK_RAW) 1711 return -ESOCKTNOSUPPORT; 1712 1713 if (protocol) 1714 return -EPROTONOSUPPORT; 1715 1716 sock->state = SS_UNCONNECTED; 1717 1718 sk = sk_alloc(net, PF_XDP, GFP_KERNEL, &xsk_proto, kern); 1719 if (!sk) 1720 return -ENOBUFS; 1721 1722 sock->ops = &xsk_proto_ops; 1723 1724 sock_init_data(sock, sk); 1725 1726 sk->sk_family = PF_XDP; 1727 1728 sk->sk_destruct = xsk_destruct; 1729 1730 sock_set_flag(sk, SOCK_RCU_FREE); 1731 1732 xs = xdp_sk(sk); 1733 xs->state = XSK_READY; 1734 mutex_init(&xs->mutex); 1735 spin_lock_init(&xs->rx_lock); 1736 1737 INIT_LIST_HEAD(&xs->map_list); 1738 spin_lock_init(&xs->map_list_lock); 1739 1740 mutex_lock(&net->xdp.lock); 1741 sk_add_node_rcu(sk, &net->xdp.list); 1742 mutex_unlock(&net->xdp.lock); 1743 1744 sock_prot_inuse_add(net, &xsk_proto, 1); 1745 1746 return 0; 1747} 1748 1749static const struct net_proto_family xsk_family_ops = { 1750 .family = PF_XDP, 1751 .create = xsk_create, 1752 .owner = THIS_MODULE, 1753}; 1754 1755static struct notifier_block xsk_netdev_notifier = { 1756 .notifier_call = xsk_notifier, 1757}; 1758 1759static int __net_init xsk_net_init(struct net *net) 1760{ 1761 mutex_init(&net->xdp.lock); 1762 INIT_HLIST_HEAD(&net->xdp.list); 1763 return 0; 1764} 1765 1766static void __net_exit xsk_net_exit(struct net *net) 1767{ 1768 WARN_ON_ONCE(!hlist_empty(&net->xdp.list)); 1769} 1770 1771static struct pernet_operations xsk_net_ops = { 1772 .init = xsk_net_init, 1773 .exit = xsk_net_exit, 1774}; 1775 1776static int __init xsk_init(void) 1777{ 1778 int err, cpu; 1779 1780 err = proto_register(&xsk_proto, 0 /* no slab */); 1781 if (err) 1782 goto out; 1783 1784 err = sock_register(&xsk_family_ops); 1785 if (err) 1786 goto out_proto; 1787 1788 err = register_pernet_subsys(&xsk_net_ops); 1789 if (err) 1790 goto out_sk; 1791 1792 err = register_netdevice_notifier(&xsk_netdev_notifier); 1793 if (err) 1794 goto out_pernet; 1795 1796 for_each_possible_cpu(cpu) 1797 INIT_LIST_HEAD(&per_cpu(xskmap_flush_list, cpu)); 1798 return 0; 1799 1800out_pernet: 1801 unregister_pernet_subsys(&xsk_net_ops); 1802out_sk: 1803 sock_unregister(PF_XDP); 1804out_proto: 1805 proto_unregister(&xsk_proto); 1806out: 1807 return err; 1808} 1809 1810fs_initcall(xsk_init); 1811