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 if (!xsk_is_bound(xs)) 317 return -ENXIO; 318 319 if (xs->dev != xdp->rxq->dev || xs->queue_id != xdp->rxq->queue_index) 320 return -EINVAL; 321 322 if (len > xsk_pool_get_rx_frame_size(xs->pool) && !xs->sg) { 323 xs->rx_dropped++; 324 return -ENOSPC; 325 } 326 327 sk_mark_napi_id_once_xdp(&xs->sk, xdp); 328 return 0; 329} 330 331static void xsk_flush(struct xdp_sock *xs) 332{ 333 xskq_prod_submit(xs->rx); 334 __xskq_cons_release(xs->pool->fq); 335 sock_def_readable(&xs->sk); 336} 337 338int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp) 339{ 340 u32 len = xdp_get_buff_len(xdp); 341 int err; 342 343 spin_lock_bh(&xs->rx_lock); 344 err = xsk_rcv_check(xs, xdp, len); 345 if (!err) { 346 err = __xsk_rcv(xs, xdp, len); 347 xsk_flush(xs); 348 } 349 spin_unlock_bh(&xs->rx_lock); 350 return err; 351} 352 353static int xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp) 354{ 355 u32 len = xdp_get_buff_len(xdp); 356 int err; 357 358 err = xsk_rcv_check(xs, xdp, len); 359 if (err) 360 return err; 361 362 if (xdp->rxq->mem.type == MEM_TYPE_XSK_BUFF_POOL) { 363 len = xdp->data_end - xdp->data; 364 return xsk_rcv_zc(xs, xdp, len); 365 } 366 367 err = __xsk_rcv(xs, xdp, len); 368 if (!err) 369 xdp_return_buff(xdp); 370 return err; 371} 372 373int __xsk_map_redirect(struct xdp_sock *xs, struct xdp_buff *xdp) 374{ 375 struct list_head *flush_list = this_cpu_ptr(&xskmap_flush_list); 376 int err; 377 378 err = xsk_rcv(xs, xdp); 379 if (err) 380 return err; 381 382 if (!xs->flush_node.prev) 383 list_add(&xs->flush_node, flush_list); 384 385 return 0; 386} 387 388void __xsk_map_flush(void) 389{ 390 struct list_head *flush_list = this_cpu_ptr(&xskmap_flush_list); 391 struct xdp_sock *xs, *tmp; 392 393 list_for_each_entry_safe(xs, tmp, flush_list, flush_node) { 394 xsk_flush(xs); 395 __list_del_clearprev(&xs->flush_node); 396 } 397} 398 399#ifdef CONFIG_DEBUG_NET 400bool xsk_map_check_flush(void) 401{ 402 if (list_empty(this_cpu_ptr(&xskmap_flush_list))) 403 return false; 404 __xsk_map_flush(); 405 return true; 406} 407#endif 408 409void xsk_tx_completed(struct xsk_buff_pool *pool, u32 nb_entries) 410{ 411 xskq_prod_submit_n(pool->cq, nb_entries); 412} 413EXPORT_SYMBOL(xsk_tx_completed); 414 415void xsk_tx_release(struct xsk_buff_pool *pool) 416{ 417 struct xdp_sock *xs; 418 419 rcu_read_lock(); 420 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) { 421 __xskq_cons_release(xs->tx); 422 if (xsk_tx_writeable(xs)) 423 xs->sk.sk_write_space(&xs->sk); 424 } 425 rcu_read_unlock(); 426} 427EXPORT_SYMBOL(xsk_tx_release); 428 429bool xsk_tx_peek_desc(struct xsk_buff_pool *pool, struct xdp_desc *desc) 430{ 431 bool budget_exhausted = false; 432 struct xdp_sock *xs; 433 434 rcu_read_lock(); 435again: 436 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) { 437 if (xs->tx_budget_spent >= MAX_PER_SOCKET_BUDGET) { 438 budget_exhausted = true; 439 continue; 440 } 441 442 if (!xskq_cons_peek_desc(xs->tx, desc, pool)) { 443 if (xskq_has_descs(xs->tx)) 444 xskq_cons_release(xs->tx); 445 continue; 446 } 447 448 xs->tx_budget_spent++; 449 450 /* This is the backpressure mechanism for the Tx path. 451 * Reserve space in the completion queue and only proceed 452 * if there is space in it. This avoids having to implement 453 * any buffering in the Tx path. 454 */ 455 if (xskq_prod_reserve_addr(pool->cq, desc->addr)) 456 goto out; 457 458 xskq_cons_release(xs->tx); 459 rcu_read_unlock(); 460 return true; 461 } 462 463 if (budget_exhausted) { 464 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) 465 xs->tx_budget_spent = 0; 466 467 budget_exhausted = false; 468 goto again; 469 } 470 471out: 472 rcu_read_unlock(); 473 return false; 474} 475EXPORT_SYMBOL(xsk_tx_peek_desc); 476 477static u32 xsk_tx_peek_release_fallback(struct xsk_buff_pool *pool, u32 max_entries) 478{ 479 struct xdp_desc *descs = pool->tx_descs; 480 u32 nb_pkts = 0; 481 482 while (nb_pkts < max_entries && xsk_tx_peek_desc(pool, &descs[nb_pkts])) 483 nb_pkts++; 484 485 xsk_tx_release(pool); 486 return nb_pkts; 487} 488 489u32 xsk_tx_peek_release_desc_batch(struct xsk_buff_pool *pool, u32 nb_pkts) 490{ 491 struct xdp_sock *xs; 492 493 rcu_read_lock(); 494 if (!list_is_singular(&pool->xsk_tx_list)) { 495 /* Fallback to the non-batched version */ 496 rcu_read_unlock(); 497 return xsk_tx_peek_release_fallback(pool, nb_pkts); 498 } 499 500 xs = list_first_or_null_rcu(&pool->xsk_tx_list, struct xdp_sock, tx_list); 501 if (!xs) { 502 nb_pkts = 0; 503 goto out; 504 } 505 506 nb_pkts = xskq_cons_nb_entries(xs->tx, nb_pkts); 507 508 /* This is the backpressure mechanism for the Tx path. Try to 509 * reserve space in the completion queue for all packets, but 510 * if there are fewer slots available, just process that many 511 * packets. This avoids having to implement any buffering in 512 * the Tx path. 513 */ 514 nb_pkts = xskq_prod_nb_free(pool->cq, nb_pkts); 515 if (!nb_pkts) 516 goto out; 517 518 nb_pkts = xskq_cons_read_desc_batch(xs->tx, pool, nb_pkts); 519 if (!nb_pkts) { 520 xs->tx->queue_empty_descs++; 521 goto out; 522 } 523 524 __xskq_cons_release(xs->tx); 525 xskq_prod_write_addr_batch(pool->cq, pool->tx_descs, nb_pkts); 526 xs->sk.sk_write_space(&xs->sk); 527 528out: 529 rcu_read_unlock(); 530 return nb_pkts; 531} 532EXPORT_SYMBOL(xsk_tx_peek_release_desc_batch); 533 534static int xsk_wakeup(struct xdp_sock *xs, u8 flags) 535{ 536 struct net_device *dev = xs->dev; 537 538 return dev->netdev_ops->ndo_xsk_wakeup(dev, xs->queue_id, flags); 539} 540 541static int xsk_cq_reserve_addr_locked(struct xdp_sock *xs, u64 addr) 542{ 543 unsigned long flags; 544 int ret; 545 546 spin_lock_irqsave(&xs->pool->cq_lock, flags); 547 ret = xskq_prod_reserve_addr(xs->pool->cq, addr); 548 spin_unlock_irqrestore(&xs->pool->cq_lock, flags); 549 550 return ret; 551} 552 553static void xsk_cq_submit_locked(struct xdp_sock *xs, u32 n) 554{ 555 unsigned long flags; 556 557 spin_lock_irqsave(&xs->pool->cq_lock, flags); 558 xskq_prod_submit_n(xs->pool->cq, n); 559 spin_unlock_irqrestore(&xs->pool->cq_lock, flags); 560} 561 562static void xsk_cq_cancel_locked(struct xdp_sock *xs, u32 n) 563{ 564 unsigned long flags; 565 566 spin_lock_irqsave(&xs->pool->cq_lock, flags); 567 xskq_prod_cancel_n(xs->pool->cq, n); 568 spin_unlock_irqrestore(&xs->pool->cq_lock, flags); 569} 570 571static u32 xsk_get_num_desc(struct sk_buff *skb) 572{ 573 return skb ? (long)skb_shinfo(skb)->destructor_arg : 0; 574} 575 576static void xsk_destruct_skb(struct sk_buff *skb) 577{ 578 struct xsk_tx_metadata_compl *compl = &skb_shinfo(skb)->xsk_meta; 579 580 if (compl->tx_timestamp) { 581 /* sw completion timestamp, not a real one */ 582 *compl->tx_timestamp = ktime_get_tai_fast_ns(); 583 } 584 585 xsk_cq_submit_locked(xdp_sk(skb->sk), xsk_get_num_desc(skb)); 586 sock_wfree(skb); 587} 588 589static void xsk_set_destructor_arg(struct sk_buff *skb) 590{ 591 long num = xsk_get_num_desc(xdp_sk(skb->sk)->skb) + 1; 592 593 skb_shinfo(skb)->destructor_arg = (void *)num; 594} 595 596static void xsk_consume_skb(struct sk_buff *skb) 597{ 598 struct xdp_sock *xs = xdp_sk(skb->sk); 599 600 skb->destructor = sock_wfree; 601 xsk_cq_cancel_locked(xs, xsk_get_num_desc(skb)); 602 /* Free skb without triggering the perf drop trace */ 603 consume_skb(skb); 604 xs->skb = NULL; 605} 606 607static void xsk_drop_skb(struct sk_buff *skb) 608{ 609 xdp_sk(skb->sk)->tx->invalid_descs += xsk_get_num_desc(skb); 610 xsk_consume_skb(skb); 611} 612 613static struct sk_buff *xsk_build_skb_zerocopy(struct xdp_sock *xs, 614 struct xdp_desc *desc) 615{ 616 struct xsk_buff_pool *pool = xs->pool; 617 u32 hr, len, ts, offset, copy, copied; 618 struct sk_buff *skb = xs->skb; 619 struct page *page; 620 void *buffer; 621 int err, i; 622 u64 addr; 623 624 if (!skb) { 625 hr = max(NET_SKB_PAD, L1_CACHE_ALIGN(xs->dev->needed_headroom)); 626 627 skb = sock_alloc_send_skb(&xs->sk, hr, 1, &err); 628 if (unlikely(!skb)) 629 return ERR_PTR(err); 630 631 skb_reserve(skb, hr); 632 } 633 634 addr = desc->addr; 635 len = desc->len; 636 ts = pool->unaligned ? len : pool->chunk_size; 637 638 buffer = xsk_buff_raw_get_data(pool, addr); 639 offset = offset_in_page(buffer); 640 addr = buffer - pool->addrs; 641 642 for (copied = 0, i = skb_shinfo(skb)->nr_frags; copied < len; i++) { 643 if (unlikely(i >= MAX_SKB_FRAGS)) 644 return ERR_PTR(-EOVERFLOW); 645 646 page = pool->umem->pgs[addr >> PAGE_SHIFT]; 647 get_page(page); 648 649 copy = min_t(u32, PAGE_SIZE - offset, len - copied); 650 skb_fill_page_desc(skb, i, page, offset, copy); 651 652 copied += copy; 653 addr += copy; 654 offset = 0; 655 } 656 657 skb->len += len; 658 skb->data_len += len; 659 skb->truesize += ts; 660 661 refcount_add(ts, &xs->sk.sk_wmem_alloc); 662 663 return skb; 664} 665 666static struct sk_buff *xsk_build_skb(struct xdp_sock *xs, 667 struct xdp_desc *desc) 668{ 669 struct xsk_tx_metadata *meta = NULL; 670 struct net_device *dev = xs->dev; 671 struct sk_buff *skb = xs->skb; 672 bool first_frag = false; 673 int err; 674 675 if (dev->priv_flags & IFF_TX_SKB_NO_LINEAR) { 676 skb = xsk_build_skb_zerocopy(xs, desc); 677 if (IS_ERR(skb)) { 678 err = PTR_ERR(skb); 679 goto free_err; 680 } 681 } else { 682 u32 hr, tr, len; 683 void *buffer; 684 685 buffer = xsk_buff_raw_get_data(xs->pool, desc->addr); 686 len = desc->len; 687 688 if (!skb) { 689 hr = max(NET_SKB_PAD, L1_CACHE_ALIGN(dev->needed_headroom)); 690 tr = dev->needed_tailroom; 691 skb = sock_alloc_send_skb(&xs->sk, hr + len + tr, 1, &err); 692 if (unlikely(!skb)) 693 goto free_err; 694 695 skb_reserve(skb, hr); 696 skb_put(skb, len); 697 698 err = skb_store_bits(skb, 0, buffer, len); 699 if (unlikely(err)) { 700 kfree_skb(skb); 701 goto free_err; 702 } 703 704 first_frag = true; 705 } else { 706 int nr_frags = skb_shinfo(skb)->nr_frags; 707 struct page *page; 708 u8 *vaddr; 709 710 if (unlikely(nr_frags == (MAX_SKB_FRAGS - 1) && xp_mb_desc(desc))) { 711 err = -EOVERFLOW; 712 goto free_err; 713 } 714 715 page = alloc_page(xs->sk.sk_allocation); 716 if (unlikely(!page)) { 717 err = -EAGAIN; 718 goto free_err; 719 } 720 721 vaddr = kmap_local_page(page); 722 memcpy(vaddr, buffer, len); 723 kunmap_local(vaddr); 724 725 skb_add_rx_frag(skb, nr_frags, page, 0, len, PAGE_SIZE); 726 refcount_add(PAGE_SIZE, &xs->sk.sk_wmem_alloc); 727 } 728 729 if (first_frag && desc->options & XDP_TX_METADATA) { 730 if (unlikely(xs->pool->tx_metadata_len == 0)) { 731 err = -EINVAL; 732 goto free_err; 733 } 734 735 meta = buffer - xs->pool->tx_metadata_len; 736 if (unlikely(!xsk_buff_valid_tx_metadata(meta))) { 737 err = -EINVAL; 738 goto free_err; 739 } 740 741 if (meta->flags & XDP_TXMD_FLAGS_CHECKSUM) { 742 if (unlikely(meta->request.csum_start + 743 meta->request.csum_offset + 744 sizeof(__sum16) > len)) { 745 err = -EINVAL; 746 goto free_err; 747 } 748 749 skb->csum_start = hr + meta->request.csum_start; 750 skb->csum_offset = meta->request.csum_offset; 751 skb->ip_summed = CHECKSUM_PARTIAL; 752 753 if (unlikely(xs->pool->tx_sw_csum)) { 754 err = skb_checksum_help(skb); 755 if (err) 756 goto free_err; 757 } 758 } 759 } 760 } 761 762 skb->dev = dev; 763 skb->priority = READ_ONCE(xs->sk.sk_priority); 764 skb->mark = READ_ONCE(xs->sk.sk_mark); 765 skb->destructor = xsk_destruct_skb; 766 xsk_tx_metadata_to_compl(meta, &skb_shinfo(skb)->xsk_meta); 767 xsk_set_destructor_arg(skb); 768 769 return skb; 770 771free_err: 772 if (err == -EOVERFLOW) { 773 /* Drop the packet */ 774 xsk_set_destructor_arg(xs->skb); 775 xsk_drop_skb(xs->skb); 776 xskq_cons_release(xs->tx); 777 } else { 778 /* Let application retry */ 779 xsk_cq_cancel_locked(xs, 1); 780 } 781 782 return ERR_PTR(err); 783} 784 785static int __xsk_generic_xmit(struct sock *sk) 786{ 787 struct xdp_sock *xs = xdp_sk(sk); 788 u32 max_batch = TX_BATCH_SIZE; 789 bool sent_frame = false; 790 struct xdp_desc desc; 791 struct sk_buff *skb; 792 int err = 0; 793 794 mutex_lock(&xs->mutex); 795 796 /* Since we dropped the RCU read lock, the socket state might have changed. */ 797 if (unlikely(!xsk_is_bound(xs))) { 798 err = -ENXIO; 799 goto out; 800 } 801 802 if (xs->queue_id >= xs->dev->real_num_tx_queues) 803 goto out; 804 805 while (xskq_cons_peek_desc(xs->tx, &desc, xs->pool)) { 806 if (max_batch-- == 0) { 807 err = -EAGAIN; 808 goto out; 809 } 810 811 /* This is the backpressure mechanism for the Tx path. 812 * Reserve space in the completion queue and only proceed 813 * if there is space in it. This avoids having to implement 814 * any buffering in the Tx path. 815 */ 816 if (xsk_cq_reserve_addr_locked(xs, desc.addr)) 817 goto out; 818 819 skb = xsk_build_skb(xs, &desc); 820 if (IS_ERR(skb)) { 821 err = PTR_ERR(skb); 822 if (err != -EOVERFLOW) 823 goto out; 824 err = 0; 825 continue; 826 } 827 828 xskq_cons_release(xs->tx); 829 830 if (xp_mb_desc(&desc)) { 831 xs->skb = skb; 832 continue; 833 } 834 835 err = __dev_direct_xmit(skb, xs->queue_id); 836 if (err == NETDEV_TX_BUSY) { 837 /* Tell user-space to retry the send */ 838 xskq_cons_cancel_n(xs->tx, xsk_get_num_desc(skb)); 839 xsk_consume_skb(skb); 840 err = -EAGAIN; 841 goto out; 842 } 843 844 /* Ignore NET_XMIT_CN as packet might have been sent */ 845 if (err == NET_XMIT_DROP) { 846 /* SKB completed but not sent */ 847 err = -EBUSY; 848 xs->skb = NULL; 849 goto out; 850 } 851 852 sent_frame = true; 853 xs->skb = NULL; 854 } 855 856 if (xskq_has_descs(xs->tx)) { 857 if (xs->skb) 858 xsk_drop_skb(xs->skb); 859 xskq_cons_release(xs->tx); 860 } 861 862out: 863 if (sent_frame) 864 if (xsk_tx_writeable(xs)) 865 sk->sk_write_space(sk); 866 867 mutex_unlock(&xs->mutex); 868 return err; 869} 870 871static int xsk_generic_xmit(struct sock *sk) 872{ 873 int ret; 874 875 /* Drop the RCU lock since the SKB path might sleep. */ 876 rcu_read_unlock(); 877 ret = __xsk_generic_xmit(sk); 878 /* Reaquire RCU lock before going into common code. */ 879 rcu_read_lock(); 880 881 return ret; 882} 883 884static bool xsk_no_wakeup(struct sock *sk) 885{ 886#ifdef CONFIG_NET_RX_BUSY_POLL 887 /* Prefer busy-polling, skip the wakeup. */ 888 return READ_ONCE(sk->sk_prefer_busy_poll) && READ_ONCE(sk->sk_ll_usec) && 889 READ_ONCE(sk->sk_napi_id) >= MIN_NAPI_ID; 890#else 891 return false; 892#endif 893} 894 895static int xsk_check_common(struct xdp_sock *xs) 896{ 897 if (unlikely(!xsk_is_bound(xs))) 898 return -ENXIO; 899 if (unlikely(!(xs->dev->flags & IFF_UP))) 900 return -ENETDOWN; 901 902 return 0; 903} 904 905static int __xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len) 906{ 907 bool need_wait = !(m->msg_flags & MSG_DONTWAIT); 908 struct sock *sk = sock->sk; 909 struct xdp_sock *xs = xdp_sk(sk); 910 struct xsk_buff_pool *pool; 911 int err; 912 913 err = xsk_check_common(xs); 914 if (err) 915 return err; 916 if (unlikely(need_wait)) 917 return -EOPNOTSUPP; 918 if (unlikely(!xs->tx)) 919 return -ENOBUFS; 920 921 if (sk_can_busy_loop(sk)) { 922 if (xs->zc) 923 __sk_mark_napi_id_once(sk, xsk_pool_get_napi_id(xs->pool)); 924 sk_busy_loop(sk, 1); /* only support non-blocking sockets */ 925 } 926 927 if (xs->zc && xsk_no_wakeup(sk)) 928 return 0; 929 930 pool = xs->pool; 931 if (pool->cached_need_wakeup & XDP_WAKEUP_TX) { 932 if (xs->zc) 933 return xsk_wakeup(xs, XDP_WAKEUP_TX); 934 return xsk_generic_xmit(sk); 935 } 936 return 0; 937} 938 939static int xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len) 940{ 941 int ret; 942 943 rcu_read_lock(); 944 ret = __xsk_sendmsg(sock, m, total_len); 945 rcu_read_unlock(); 946 947 return ret; 948} 949 950static int __xsk_recvmsg(struct socket *sock, struct msghdr *m, size_t len, int flags) 951{ 952 bool need_wait = !(flags & MSG_DONTWAIT); 953 struct sock *sk = sock->sk; 954 struct xdp_sock *xs = xdp_sk(sk); 955 int err; 956 957 err = xsk_check_common(xs); 958 if (err) 959 return err; 960 if (unlikely(!xs->rx)) 961 return -ENOBUFS; 962 if (unlikely(need_wait)) 963 return -EOPNOTSUPP; 964 965 if (sk_can_busy_loop(sk)) 966 sk_busy_loop(sk, 1); /* only support non-blocking sockets */ 967 968 if (xsk_no_wakeup(sk)) 969 return 0; 970 971 if (xs->pool->cached_need_wakeup & XDP_WAKEUP_RX && xs->zc) 972 return xsk_wakeup(xs, XDP_WAKEUP_RX); 973 return 0; 974} 975 976static int xsk_recvmsg(struct socket *sock, struct msghdr *m, size_t len, int flags) 977{ 978 int ret; 979 980 rcu_read_lock(); 981 ret = __xsk_recvmsg(sock, m, len, flags); 982 rcu_read_unlock(); 983 984 return ret; 985} 986 987static __poll_t xsk_poll(struct file *file, struct socket *sock, 988 struct poll_table_struct *wait) 989{ 990 __poll_t mask = 0; 991 struct sock *sk = sock->sk; 992 struct xdp_sock *xs = xdp_sk(sk); 993 struct xsk_buff_pool *pool; 994 995 sock_poll_wait(file, sock, wait); 996 997 rcu_read_lock(); 998 if (xsk_check_common(xs)) 999 goto out; 1000 1001 pool = xs->pool; 1002 1003 if (pool->cached_need_wakeup) { 1004 if (xs->zc) 1005 xsk_wakeup(xs, pool->cached_need_wakeup); 1006 else if (xs->tx) 1007 /* Poll needs to drive Tx also in copy mode */ 1008 xsk_generic_xmit(sk); 1009 } 1010 1011 if (xs->rx && !xskq_prod_is_empty(xs->rx)) 1012 mask |= EPOLLIN | EPOLLRDNORM; 1013 if (xs->tx && xsk_tx_writeable(xs)) 1014 mask |= EPOLLOUT | EPOLLWRNORM; 1015out: 1016 rcu_read_unlock(); 1017 return mask; 1018} 1019 1020static int xsk_init_queue(u32 entries, struct xsk_queue **queue, 1021 bool umem_queue) 1022{ 1023 struct xsk_queue *q; 1024 1025 if (entries == 0 || *queue || !is_power_of_2(entries)) 1026 return -EINVAL; 1027 1028 q = xskq_create(entries, umem_queue); 1029 if (!q) 1030 return -ENOMEM; 1031 1032 /* Make sure queue is ready before it can be seen by others */ 1033 smp_wmb(); 1034 WRITE_ONCE(*queue, q); 1035 return 0; 1036} 1037 1038static void xsk_unbind_dev(struct xdp_sock *xs) 1039{ 1040 struct net_device *dev = xs->dev; 1041 1042 if (xs->state != XSK_BOUND) 1043 return; 1044 WRITE_ONCE(xs->state, XSK_UNBOUND); 1045 1046 /* Wait for driver to stop using the xdp socket. */ 1047 xp_del_xsk(xs->pool, xs); 1048 synchronize_net(); 1049 dev_put(dev); 1050} 1051 1052static struct xsk_map *xsk_get_map_list_entry(struct xdp_sock *xs, 1053 struct xdp_sock __rcu ***map_entry) 1054{ 1055 struct xsk_map *map = NULL; 1056 struct xsk_map_node *node; 1057 1058 *map_entry = NULL; 1059 1060 spin_lock_bh(&xs->map_list_lock); 1061 node = list_first_entry_or_null(&xs->map_list, struct xsk_map_node, 1062 node); 1063 if (node) { 1064 bpf_map_inc(&node->map->map); 1065 map = node->map; 1066 *map_entry = node->map_entry; 1067 } 1068 spin_unlock_bh(&xs->map_list_lock); 1069 return map; 1070} 1071 1072static void xsk_delete_from_maps(struct xdp_sock *xs) 1073{ 1074 /* This function removes the current XDP socket from all the 1075 * maps it resides in. We need to take extra care here, due to 1076 * the two locks involved. Each map has a lock synchronizing 1077 * updates to the entries, and each socket has a lock that 1078 * synchronizes access to the list of maps (map_list). For 1079 * deadlock avoidance the locks need to be taken in the order 1080 * "map lock"->"socket map list lock". We start off by 1081 * accessing the socket map list, and take a reference to the 1082 * map to guarantee existence between the 1083 * xsk_get_map_list_entry() and xsk_map_try_sock_delete() 1084 * calls. Then we ask the map to remove the socket, which 1085 * tries to remove the socket from the map. Note that there 1086 * might be updates to the map between 1087 * xsk_get_map_list_entry() and xsk_map_try_sock_delete(). 1088 */ 1089 struct xdp_sock __rcu **map_entry = NULL; 1090 struct xsk_map *map; 1091 1092 while ((map = xsk_get_map_list_entry(xs, &map_entry))) { 1093 xsk_map_try_sock_delete(map, xs, map_entry); 1094 bpf_map_put(&map->map); 1095 } 1096} 1097 1098static int xsk_release(struct socket *sock) 1099{ 1100 struct sock *sk = sock->sk; 1101 struct xdp_sock *xs = xdp_sk(sk); 1102 struct net *net; 1103 1104 if (!sk) 1105 return 0; 1106 1107 net = sock_net(sk); 1108 1109 if (xs->skb) 1110 xsk_drop_skb(xs->skb); 1111 1112 mutex_lock(&net->xdp.lock); 1113 sk_del_node_init_rcu(sk); 1114 mutex_unlock(&net->xdp.lock); 1115 1116 sock_prot_inuse_add(net, sk->sk_prot, -1); 1117 1118 xsk_delete_from_maps(xs); 1119 mutex_lock(&xs->mutex); 1120 xsk_unbind_dev(xs); 1121 mutex_unlock(&xs->mutex); 1122 1123 xskq_destroy(xs->rx); 1124 xskq_destroy(xs->tx); 1125 xskq_destroy(xs->fq_tmp); 1126 xskq_destroy(xs->cq_tmp); 1127 1128 sock_orphan(sk); 1129 sock->sk = NULL; 1130 1131 sock_put(sk); 1132 1133 return 0; 1134} 1135 1136static struct socket *xsk_lookup_xsk_from_fd(int fd) 1137{ 1138 struct socket *sock; 1139 int err; 1140 1141 sock = sockfd_lookup(fd, &err); 1142 if (!sock) 1143 return ERR_PTR(-ENOTSOCK); 1144 1145 if (sock->sk->sk_family != PF_XDP) { 1146 sockfd_put(sock); 1147 return ERR_PTR(-ENOPROTOOPT); 1148 } 1149 1150 return sock; 1151} 1152 1153static bool xsk_validate_queues(struct xdp_sock *xs) 1154{ 1155 return xs->fq_tmp && xs->cq_tmp; 1156} 1157 1158static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len) 1159{ 1160 struct sockaddr_xdp *sxdp = (struct sockaddr_xdp *)addr; 1161 struct sock *sk = sock->sk; 1162 struct xdp_sock *xs = xdp_sk(sk); 1163 struct net_device *dev; 1164 int bound_dev_if; 1165 u32 flags, qid; 1166 int err = 0; 1167 1168 if (addr_len < sizeof(struct sockaddr_xdp)) 1169 return -EINVAL; 1170 if (sxdp->sxdp_family != AF_XDP) 1171 return -EINVAL; 1172 1173 flags = sxdp->sxdp_flags; 1174 if (flags & ~(XDP_SHARED_UMEM | XDP_COPY | XDP_ZEROCOPY | 1175 XDP_USE_NEED_WAKEUP | XDP_USE_SG)) 1176 return -EINVAL; 1177 1178 bound_dev_if = READ_ONCE(sk->sk_bound_dev_if); 1179 if (bound_dev_if && bound_dev_if != sxdp->sxdp_ifindex) 1180 return -EINVAL; 1181 1182 rtnl_lock(); 1183 mutex_lock(&xs->mutex); 1184 if (xs->state != XSK_READY) { 1185 err = -EBUSY; 1186 goto out_release; 1187 } 1188 1189 dev = dev_get_by_index(sock_net(sk), sxdp->sxdp_ifindex); 1190 if (!dev) { 1191 err = -ENODEV; 1192 goto out_release; 1193 } 1194 1195 if (!xs->rx && !xs->tx) { 1196 err = -EINVAL; 1197 goto out_unlock; 1198 } 1199 1200 qid = sxdp->sxdp_queue_id; 1201 1202 if (flags & XDP_SHARED_UMEM) { 1203 struct xdp_sock *umem_xs; 1204 struct socket *sock; 1205 1206 if ((flags & XDP_COPY) || (flags & XDP_ZEROCOPY) || 1207 (flags & XDP_USE_NEED_WAKEUP) || (flags & XDP_USE_SG)) { 1208 /* Cannot specify flags for shared sockets. */ 1209 err = -EINVAL; 1210 goto out_unlock; 1211 } 1212 1213 if (xs->umem) { 1214 /* We have already our own. */ 1215 err = -EINVAL; 1216 goto out_unlock; 1217 } 1218 1219 sock = xsk_lookup_xsk_from_fd(sxdp->sxdp_shared_umem_fd); 1220 if (IS_ERR(sock)) { 1221 err = PTR_ERR(sock); 1222 goto out_unlock; 1223 } 1224 1225 umem_xs = xdp_sk(sock->sk); 1226 if (!xsk_is_bound(umem_xs)) { 1227 err = -EBADF; 1228 sockfd_put(sock); 1229 goto out_unlock; 1230 } 1231 1232 if (umem_xs->queue_id != qid || umem_xs->dev != dev) { 1233 /* Share the umem with another socket on another qid 1234 * and/or device. 1235 */ 1236 xs->pool = xp_create_and_assign_umem(xs, 1237 umem_xs->umem); 1238 if (!xs->pool) { 1239 err = -ENOMEM; 1240 sockfd_put(sock); 1241 goto out_unlock; 1242 } 1243 1244 err = xp_assign_dev_shared(xs->pool, umem_xs, dev, 1245 qid); 1246 if (err) { 1247 xp_destroy(xs->pool); 1248 xs->pool = NULL; 1249 sockfd_put(sock); 1250 goto out_unlock; 1251 } 1252 } else { 1253 /* Share the buffer pool with the other socket. */ 1254 if (xs->fq_tmp || xs->cq_tmp) { 1255 /* Do not allow setting your own fq or cq. */ 1256 err = -EINVAL; 1257 sockfd_put(sock); 1258 goto out_unlock; 1259 } 1260 1261 xp_get_pool(umem_xs->pool); 1262 xs->pool = umem_xs->pool; 1263 1264 /* If underlying shared umem was created without Tx 1265 * ring, allocate Tx descs array that Tx batching API 1266 * utilizes 1267 */ 1268 if (xs->tx && !xs->pool->tx_descs) { 1269 err = xp_alloc_tx_descs(xs->pool, xs); 1270 if (err) { 1271 xp_put_pool(xs->pool); 1272 xs->pool = NULL; 1273 sockfd_put(sock); 1274 goto out_unlock; 1275 } 1276 } 1277 } 1278 1279 xdp_get_umem(umem_xs->umem); 1280 WRITE_ONCE(xs->umem, umem_xs->umem); 1281 sockfd_put(sock); 1282 } else if (!xs->umem || !xsk_validate_queues(xs)) { 1283 err = -EINVAL; 1284 goto out_unlock; 1285 } else { 1286 /* This xsk has its own umem. */ 1287 xs->pool = xp_create_and_assign_umem(xs, xs->umem); 1288 if (!xs->pool) { 1289 err = -ENOMEM; 1290 goto out_unlock; 1291 } 1292 1293 err = xp_assign_dev(xs->pool, dev, qid, flags); 1294 if (err) { 1295 xp_destroy(xs->pool); 1296 xs->pool = NULL; 1297 goto out_unlock; 1298 } 1299 } 1300 1301 /* FQ and CQ are now owned by the buffer pool and cleaned up with it. */ 1302 xs->fq_tmp = NULL; 1303 xs->cq_tmp = NULL; 1304 1305 xs->dev = dev; 1306 xs->zc = xs->umem->zc; 1307 xs->sg = !!(xs->umem->flags & XDP_UMEM_SG_FLAG); 1308 xs->queue_id = qid; 1309 xp_add_xsk(xs->pool, xs); 1310 1311out_unlock: 1312 if (err) { 1313 dev_put(dev); 1314 } else { 1315 /* Matches smp_rmb() in bind() for shared umem 1316 * sockets, and xsk_is_bound(). 1317 */ 1318 smp_wmb(); 1319 WRITE_ONCE(xs->state, XSK_BOUND); 1320 } 1321out_release: 1322 mutex_unlock(&xs->mutex); 1323 rtnl_unlock(); 1324 return err; 1325} 1326 1327struct xdp_umem_reg_v1 { 1328 __u64 addr; /* Start of packet data area */ 1329 __u64 len; /* Length of packet data area */ 1330 __u32 chunk_size; 1331 __u32 headroom; 1332}; 1333 1334struct xdp_umem_reg_v2 { 1335 __u64 addr; /* Start of packet data area */ 1336 __u64 len; /* Length of packet data area */ 1337 __u32 chunk_size; 1338 __u32 headroom; 1339 __u32 flags; 1340}; 1341 1342static int xsk_setsockopt(struct socket *sock, int level, int optname, 1343 sockptr_t optval, unsigned int optlen) 1344{ 1345 struct sock *sk = sock->sk; 1346 struct xdp_sock *xs = xdp_sk(sk); 1347 int err; 1348 1349 if (level != SOL_XDP) 1350 return -ENOPROTOOPT; 1351 1352 switch (optname) { 1353 case XDP_RX_RING: 1354 case XDP_TX_RING: 1355 { 1356 struct xsk_queue **q; 1357 int entries; 1358 1359 if (optlen < sizeof(entries)) 1360 return -EINVAL; 1361 if (copy_from_sockptr(&entries, optval, sizeof(entries))) 1362 return -EFAULT; 1363 1364 mutex_lock(&xs->mutex); 1365 if (xs->state != XSK_READY) { 1366 mutex_unlock(&xs->mutex); 1367 return -EBUSY; 1368 } 1369 q = (optname == XDP_TX_RING) ? &xs->tx : &xs->rx; 1370 err = xsk_init_queue(entries, q, false); 1371 if (!err && optname == XDP_TX_RING) 1372 /* Tx needs to be explicitly woken up the first time */ 1373 xs->tx->ring->flags |= XDP_RING_NEED_WAKEUP; 1374 mutex_unlock(&xs->mutex); 1375 return err; 1376 } 1377 case XDP_UMEM_REG: 1378 { 1379 size_t mr_size = sizeof(struct xdp_umem_reg); 1380 struct xdp_umem_reg mr = {}; 1381 struct xdp_umem *umem; 1382 1383 if (optlen < sizeof(struct xdp_umem_reg_v1)) 1384 return -EINVAL; 1385 else if (optlen < sizeof(struct xdp_umem_reg_v2)) 1386 mr_size = sizeof(struct xdp_umem_reg_v1); 1387 else if (optlen < sizeof(mr)) 1388 mr_size = sizeof(struct xdp_umem_reg_v2); 1389 1390 if (copy_from_sockptr(&mr, optval, mr_size)) 1391 return -EFAULT; 1392 1393 mutex_lock(&xs->mutex); 1394 if (xs->state != XSK_READY || xs->umem) { 1395 mutex_unlock(&xs->mutex); 1396 return -EBUSY; 1397 } 1398 1399 umem = xdp_umem_create(&mr); 1400 if (IS_ERR(umem)) { 1401 mutex_unlock(&xs->mutex); 1402 return PTR_ERR(umem); 1403 } 1404 1405 /* Make sure umem is ready before it can be seen by others */ 1406 smp_wmb(); 1407 WRITE_ONCE(xs->umem, umem); 1408 mutex_unlock(&xs->mutex); 1409 return 0; 1410 } 1411 case XDP_UMEM_FILL_RING: 1412 case XDP_UMEM_COMPLETION_RING: 1413 { 1414 struct xsk_queue **q; 1415 int entries; 1416 1417 if (optlen < sizeof(entries)) 1418 return -EINVAL; 1419 if (copy_from_sockptr(&entries, optval, sizeof(entries))) 1420 return -EFAULT; 1421 1422 mutex_lock(&xs->mutex); 1423 if (xs->state != XSK_READY) { 1424 mutex_unlock(&xs->mutex); 1425 return -EBUSY; 1426 } 1427 1428 q = (optname == XDP_UMEM_FILL_RING) ? &xs->fq_tmp : 1429 &xs->cq_tmp; 1430 err = xsk_init_queue(entries, q, true); 1431 mutex_unlock(&xs->mutex); 1432 return err; 1433 } 1434 default: 1435 break; 1436 } 1437 1438 return -ENOPROTOOPT; 1439} 1440 1441static void xsk_enter_rxtx_offsets(struct xdp_ring_offset_v1 *ring) 1442{ 1443 ring->producer = offsetof(struct xdp_rxtx_ring, ptrs.producer); 1444 ring->consumer = offsetof(struct xdp_rxtx_ring, ptrs.consumer); 1445 ring->desc = offsetof(struct xdp_rxtx_ring, desc); 1446} 1447 1448static void xsk_enter_umem_offsets(struct xdp_ring_offset_v1 *ring) 1449{ 1450 ring->producer = offsetof(struct xdp_umem_ring, ptrs.producer); 1451 ring->consumer = offsetof(struct xdp_umem_ring, ptrs.consumer); 1452 ring->desc = offsetof(struct xdp_umem_ring, desc); 1453} 1454 1455struct xdp_statistics_v1 { 1456 __u64 rx_dropped; 1457 __u64 rx_invalid_descs; 1458 __u64 tx_invalid_descs; 1459}; 1460 1461static int xsk_getsockopt(struct socket *sock, int level, int optname, 1462 char __user *optval, int __user *optlen) 1463{ 1464 struct sock *sk = sock->sk; 1465 struct xdp_sock *xs = xdp_sk(sk); 1466 int len; 1467 1468 if (level != SOL_XDP) 1469 return -ENOPROTOOPT; 1470 1471 if (get_user(len, optlen)) 1472 return -EFAULT; 1473 if (len < 0) 1474 return -EINVAL; 1475 1476 switch (optname) { 1477 case XDP_STATISTICS: 1478 { 1479 struct xdp_statistics stats = {}; 1480 bool extra_stats = true; 1481 size_t stats_size; 1482 1483 if (len < sizeof(struct xdp_statistics_v1)) { 1484 return -EINVAL; 1485 } else if (len < sizeof(stats)) { 1486 extra_stats = false; 1487 stats_size = sizeof(struct xdp_statistics_v1); 1488 } else { 1489 stats_size = sizeof(stats); 1490 } 1491 1492 mutex_lock(&xs->mutex); 1493 stats.rx_dropped = xs->rx_dropped; 1494 if (extra_stats) { 1495 stats.rx_ring_full = xs->rx_queue_full; 1496 stats.rx_fill_ring_empty_descs = 1497 xs->pool ? xskq_nb_queue_empty_descs(xs->pool->fq) : 0; 1498 stats.tx_ring_empty_descs = xskq_nb_queue_empty_descs(xs->tx); 1499 } else { 1500 stats.rx_dropped += xs->rx_queue_full; 1501 } 1502 stats.rx_invalid_descs = xskq_nb_invalid_descs(xs->rx); 1503 stats.tx_invalid_descs = xskq_nb_invalid_descs(xs->tx); 1504 mutex_unlock(&xs->mutex); 1505 1506 if (copy_to_user(optval, &stats, stats_size)) 1507 return -EFAULT; 1508 if (put_user(stats_size, optlen)) 1509 return -EFAULT; 1510 1511 return 0; 1512 } 1513 case XDP_MMAP_OFFSETS: 1514 { 1515 struct xdp_mmap_offsets off; 1516 struct xdp_mmap_offsets_v1 off_v1; 1517 bool flags_supported = true; 1518 void *to_copy; 1519 1520 if (len < sizeof(off_v1)) 1521 return -EINVAL; 1522 else if (len < sizeof(off)) 1523 flags_supported = false; 1524 1525 if (flags_supported) { 1526 /* xdp_ring_offset is identical to xdp_ring_offset_v1 1527 * except for the flags field added to the end. 1528 */ 1529 xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *) 1530 &off.rx); 1531 xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *) 1532 &off.tx); 1533 xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *) 1534 &off.fr); 1535 xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *) 1536 &off.cr); 1537 off.rx.flags = offsetof(struct xdp_rxtx_ring, 1538 ptrs.flags); 1539 off.tx.flags = offsetof(struct xdp_rxtx_ring, 1540 ptrs.flags); 1541 off.fr.flags = offsetof(struct xdp_umem_ring, 1542 ptrs.flags); 1543 off.cr.flags = offsetof(struct xdp_umem_ring, 1544 ptrs.flags); 1545 1546 len = sizeof(off); 1547 to_copy = &off; 1548 } else { 1549 xsk_enter_rxtx_offsets(&off_v1.rx); 1550 xsk_enter_rxtx_offsets(&off_v1.tx); 1551 xsk_enter_umem_offsets(&off_v1.fr); 1552 xsk_enter_umem_offsets(&off_v1.cr); 1553 1554 len = sizeof(off_v1); 1555 to_copy = &off_v1; 1556 } 1557 1558 if (copy_to_user(optval, to_copy, len)) 1559 return -EFAULT; 1560 if (put_user(len, optlen)) 1561 return -EFAULT; 1562 1563 return 0; 1564 } 1565 case XDP_OPTIONS: 1566 { 1567 struct xdp_options opts = {}; 1568 1569 if (len < sizeof(opts)) 1570 return -EINVAL; 1571 1572 mutex_lock(&xs->mutex); 1573 if (xs->zc) 1574 opts.flags |= XDP_OPTIONS_ZEROCOPY; 1575 mutex_unlock(&xs->mutex); 1576 1577 len = sizeof(opts); 1578 if (copy_to_user(optval, &opts, len)) 1579 return -EFAULT; 1580 if (put_user(len, optlen)) 1581 return -EFAULT; 1582 1583 return 0; 1584 } 1585 default: 1586 break; 1587 } 1588 1589 return -EOPNOTSUPP; 1590} 1591 1592static int xsk_mmap(struct file *file, struct socket *sock, 1593 struct vm_area_struct *vma) 1594{ 1595 loff_t offset = (loff_t)vma->vm_pgoff << PAGE_SHIFT; 1596 unsigned long size = vma->vm_end - vma->vm_start; 1597 struct xdp_sock *xs = xdp_sk(sock->sk); 1598 int state = READ_ONCE(xs->state); 1599 struct xsk_queue *q = NULL; 1600 1601 if (state != XSK_READY && state != XSK_BOUND) 1602 return -EBUSY; 1603 1604 if (offset == XDP_PGOFF_RX_RING) { 1605 q = READ_ONCE(xs->rx); 1606 } else if (offset == XDP_PGOFF_TX_RING) { 1607 q = READ_ONCE(xs->tx); 1608 } else { 1609 /* Matches the smp_wmb() in XDP_UMEM_REG */ 1610 smp_rmb(); 1611 if (offset == XDP_UMEM_PGOFF_FILL_RING) 1612 q = state == XSK_READY ? READ_ONCE(xs->fq_tmp) : 1613 READ_ONCE(xs->pool->fq); 1614 else if (offset == XDP_UMEM_PGOFF_COMPLETION_RING) 1615 q = state == XSK_READY ? READ_ONCE(xs->cq_tmp) : 1616 READ_ONCE(xs->pool->cq); 1617 } 1618 1619 if (!q) 1620 return -EINVAL; 1621 1622 /* Matches the smp_wmb() in xsk_init_queue */ 1623 smp_rmb(); 1624 if (size > q->ring_vmalloc_size) 1625 return -EINVAL; 1626 1627 return remap_vmalloc_range(vma, q->ring, 0); 1628} 1629 1630static int xsk_notifier(struct notifier_block *this, 1631 unsigned long msg, void *ptr) 1632{ 1633 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1634 struct net *net = dev_net(dev); 1635 struct sock *sk; 1636 1637 switch (msg) { 1638 case NETDEV_UNREGISTER: 1639 mutex_lock(&net->xdp.lock); 1640 sk_for_each(sk, &net->xdp.list) { 1641 struct xdp_sock *xs = xdp_sk(sk); 1642 1643 mutex_lock(&xs->mutex); 1644 if (xs->dev == dev) { 1645 sk->sk_err = ENETDOWN; 1646 if (!sock_flag(sk, SOCK_DEAD)) 1647 sk_error_report(sk); 1648 1649 xsk_unbind_dev(xs); 1650 1651 /* Clear device references. */ 1652 xp_clear_dev(xs->pool); 1653 } 1654 mutex_unlock(&xs->mutex); 1655 } 1656 mutex_unlock(&net->xdp.lock); 1657 break; 1658 } 1659 return NOTIFY_DONE; 1660} 1661 1662static struct proto xsk_proto = { 1663 .name = "XDP", 1664 .owner = THIS_MODULE, 1665 .obj_size = sizeof(struct xdp_sock), 1666}; 1667 1668static const struct proto_ops xsk_proto_ops = { 1669 .family = PF_XDP, 1670 .owner = THIS_MODULE, 1671 .release = xsk_release, 1672 .bind = xsk_bind, 1673 .connect = sock_no_connect, 1674 .socketpair = sock_no_socketpair, 1675 .accept = sock_no_accept, 1676 .getname = sock_no_getname, 1677 .poll = xsk_poll, 1678 .ioctl = sock_no_ioctl, 1679 .listen = sock_no_listen, 1680 .shutdown = sock_no_shutdown, 1681 .setsockopt = xsk_setsockopt, 1682 .getsockopt = xsk_getsockopt, 1683 .sendmsg = xsk_sendmsg, 1684 .recvmsg = xsk_recvmsg, 1685 .mmap = xsk_mmap, 1686}; 1687 1688static void xsk_destruct(struct sock *sk) 1689{ 1690 struct xdp_sock *xs = xdp_sk(sk); 1691 1692 if (!sock_flag(sk, SOCK_DEAD)) 1693 return; 1694 1695 if (!xp_put_pool(xs->pool)) 1696 xdp_put_umem(xs->umem, !xs->pool); 1697} 1698 1699static int xsk_create(struct net *net, struct socket *sock, int protocol, 1700 int kern) 1701{ 1702 struct xdp_sock *xs; 1703 struct sock *sk; 1704 1705 if (!ns_capable(net->user_ns, CAP_NET_RAW)) 1706 return -EPERM; 1707 if (sock->type != SOCK_RAW) 1708 return -ESOCKTNOSUPPORT; 1709 1710 if (protocol) 1711 return -EPROTONOSUPPORT; 1712 1713 sock->state = SS_UNCONNECTED; 1714 1715 sk = sk_alloc(net, PF_XDP, GFP_KERNEL, &xsk_proto, kern); 1716 if (!sk) 1717 return -ENOBUFS; 1718 1719 sock->ops = &xsk_proto_ops; 1720 1721 sock_init_data(sock, sk); 1722 1723 sk->sk_family = PF_XDP; 1724 1725 sk->sk_destruct = xsk_destruct; 1726 1727 sock_set_flag(sk, SOCK_RCU_FREE); 1728 1729 xs = xdp_sk(sk); 1730 xs->state = XSK_READY; 1731 mutex_init(&xs->mutex); 1732 spin_lock_init(&xs->rx_lock); 1733 1734 INIT_LIST_HEAD(&xs->map_list); 1735 spin_lock_init(&xs->map_list_lock); 1736 1737 mutex_lock(&net->xdp.lock); 1738 sk_add_node_rcu(sk, &net->xdp.list); 1739 mutex_unlock(&net->xdp.lock); 1740 1741 sock_prot_inuse_add(net, &xsk_proto, 1); 1742 1743 return 0; 1744} 1745 1746static const struct net_proto_family xsk_family_ops = { 1747 .family = PF_XDP, 1748 .create = xsk_create, 1749 .owner = THIS_MODULE, 1750}; 1751 1752static struct notifier_block xsk_netdev_notifier = { 1753 .notifier_call = xsk_notifier, 1754}; 1755 1756static int __net_init xsk_net_init(struct net *net) 1757{ 1758 mutex_init(&net->xdp.lock); 1759 INIT_HLIST_HEAD(&net->xdp.list); 1760 return 0; 1761} 1762 1763static void __net_exit xsk_net_exit(struct net *net) 1764{ 1765 WARN_ON_ONCE(!hlist_empty(&net->xdp.list)); 1766} 1767 1768static struct pernet_operations xsk_net_ops = { 1769 .init = xsk_net_init, 1770 .exit = xsk_net_exit, 1771}; 1772 1773static int __init xsk_init(void) 1774{ 1775 int err, cpu; 1776 1777 err = proto_register(&xsk_proto, 0 /* no slab */); 1778 if (err) 1779 goto out; 1780 1781 err = sock_register(&xsk_family_ops); 1782 if (err) 1783 goto out_proto; 1784 1785 err = register_pernet_subsys(&xsk_net_ops); 1786 if (err) 1787 goto out_sk; 1788 1789 err = register_netdevice_notifier(&xsk_netdev_notifier); 1790 if (err) 1791 goto out_pernet; 1792 1793 for_each_possible_cpu(cpu) 1794 INIT_LIST_HEAD(&per_cpu(xskmap_flush_list, cpu)); 1795 return 0; 1796 1797out_pernet: 1798 unregister_pernet_subsys(&xsk_net_ops); 1799out_sk: 1800 sock_unregister(PF_XDP); 1801out_proto: 1802 proto_unregister(&xsk_proto); 1803out: 1804 return err; 1805} 1806 1807fs_initcall(xsk_init); 1808