1 // SPDX-License-Identifier: GPL-2.0 2 /* XDP sockets 3 * 4 * AF_XDP sockets allows a channel between XDP programs and userspace 5 * applications. 6 * Copyright(c) 2018 Intel Corporation. 7 * 8 * Author(s): Björn Töpel <bjorn.topel@intel.com> 9 * Magnus Karlsson <magnus.karlsson@intel.com> 10 */ 11 12 #define pr_fmt(fmt) "AF_XDP: %s: " fmt, __func__ 13 14 #include <linux/if_xdp.h> 15 #include <linux/init.h> 16 #include <linux/sched/mm.h> 17 #include <linux/sched/signal.h> 18 #include <linux/sched/task.h> 19 #include <linux/socket.h> 20 #include <linux/file.h> 21 #include <linux/uaccess.h> 22 #include <linux/net.h> 23 #include <linux/netdevice.h> 24 #include <linux/rculist.h> 25 #include <linux/vmalloc.h> 26 #include <net/xdp_sock_drv.h> 27 #include <net/busy_poll.h> 28 #include <net/netdev_rx_queue.h> 29 #include <net/xdp.h> 30 31 #include "xsk_queue.h" 32 #include "xdp_umem.h" 33 #include "xsk.h" 34 35 #define TX_BATCH_SIZE 32 36 #define MAX_PER_SOCKET_BUDGET (TX_BATCH_SIZE) 37 38 static DEFINE_PER_CPU(struct list_head, xskmap_flush_list); 39 40 void xsk_set_rx_need_wakeup(struct xsk_buff_pool *pool) 41 { 42 if (pool->cached_need_wakeup & XDP_WAKEUP_RX) 43 return; 44 45 pool->fq->ring->flags |= XDP_RING_NEED_WAKEUP; 46 pool->cached_need_wakeup |= XDP_WAKEUP_RX; 47 } 48 EXPORT_SYMBOL(xsk_set_rx_need_wakeup); 49 50 void xsk_set_tx_need_wakeup(struct xsk_buff_pool *pool) 51 { 52 struct xdp_sock *xs; 53 54 if (pool->cached_need_wakeup & XDP_WAKEUP_TX) 55 return; 56 57 rcu_read_lock(); 58 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) { 59 xs->tx->ring->flags |= XDP_RING_NEED_WAKEUP; 60 } 61 rcu_read_unlock(); 62 63 pool->cached_need_wakeup |= XDP_WAKEUP_TX; 64 } 65 EXPORT_SYMBOL(xsk_set_tx_need_wakeup); 66 67 void xsk_clear_rx_need_wakeup(struct xsk_buff_pool *pool) 68 { 69 if (!(pool->cached_need_wakeup & XDP_WAKEUP_RX)) 70 return; 71 72 pool->fq->ring->flags &= ~XDP_RING_NEED_WAKEUP; 73 pool->cached_need_wakeup &= ~XDP_WAKEUP_RX; 74 } 75 EXPORT_SYMBOL(xsk_clear_rx_need_wakeup); 76 77 void xsk_clear_tx_need_wakeup(struct xsk_buff_pool *pool) 78 { 79 struct xdp_sock *xs; 80 81 if (!(pool->cached_need_wakeup & XDP_WAKEUP_TX)) 82 return; 83 84 rcu_read_lock(); 85 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) { 86 xs->tx->ring->flags &= ~XDP_RING_NEED_WAKEUP; 87 } 88 rcu_read_unlock(); 89 90 pool->cached_need_wakeup &= ~XDP_WAKEUP_TX; 91 } 92 EXPORT_SYMBOL(xsk_clear_tx_need_wakeup); 93 94 bool xsk_uses_need_wakeup(struct xsk_buff_pool *pool) 95 { 96 return pool->uses_need_wakeup; 97 } 98 EXPORT_SYMBOL(xsk_uses_need_wakeup); 99 100 struct xsk_buff_pool *xsk_get_pool_from_qid(struct net_device *dev, 101 u16 queue_id) 102 { 103 if (queue_id < dev->real_num_rx_queues) 104 return dev->_rx[queue_id].pool; 105 if (queue_id < dev->real_num_tx_queues) 106 return dev->_tx[queue_id].pool; 107 108 return NULL; 109 } 110 EXPORT_SYMBOL(xsk_get_pool_from_qid); 111 112 void xsk_clear_pool_at_qid(struct net_device *dev, u16 queue_id) 113 { 114 if (queue_id < dev->num_rx_queues) 115 dev->_rx[queue_id].pool = NULL; 116 if (queue_id < dev->num_tx_queues) 117 dev->_tx[queue_id].pool = NULL; 118 } 119 120 /* The buffer pool is stored both in the _rx struct and the _tx struct as we do 121 * not know if the device has more tx queues than rx, or the opposite. 122 * This might also change during run time. 123 */ 124 int xsk_reg_pool_at_qid(struct net_device *dev, struct xsk_buff_pool *pool, 125 u16 queue_id) 126 { 127 if (queue_id >= max_t(unsigned int, 128 dev->real_num_rx_queues, 129 dev->real_num_tx_queues)) 130 return -EINVAL; 131 132 if (queue_id < dev->real_num_rx_queues) 133 dev->_rx[queue_id].pool = pool; 134 if (queue_id < dev->real_num_tx_queues) 135 dev->_tx[queue_id].pool = pool; 136 137 return 0; 138 } 139 140 static int __xsk_rcv_zc(struct xdp_sock *xs, struct xdp_buff_xsk *xskb, u32 len, 141 u32 flags) 142 { 143 u64 addr; 144 int err; 145 146 addr = xp_get_handle(xskb); 147 err = xskq_prod_reserve_desc(xs->rx, addr, len, flags); 148 if (err) { 149 xs->rx_queue_full++; 150 return err; 151 } 152 153 xp_release(xskb); 154 return 0; 155 } 156 157 static int xsk_rcv_zc(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len) 158 { 159 struct xdp_buff_xsk *xskb = container_of(xdp, struct xdp_buff_xsk, xdp); 160 u32 frags = xdp_buff_has_frags(xdp); 161 struct xdp_buff_xsk *pos, *tmp; 162 struct list_head *xskb_list; 163 u32 contd = 0; 164 int err; 165 166 if (frags) 167 contd = XDP_PKT_CONTD; 168 169 err = __xsk_rcv_zc(xs, xskb, len, contd); 170 if (err || likely(!frags)) 171 goto out; 172 173 xskb_list = &xskb->pool->xskb_list; 174 list_for_each_entry_safe(pos, tmp, xskb_list, xskb_list_node) { 175 if (list_is_singular(xskb_list)) 176 contd = 0; 177 len = pos->xdp.data_end - pos->xdp.data; 178 err = __xsk_rcv_zc(xs, pos, len, contd); 179 if (err) 180 return err; 181 list_del(&pos->xskb_list_node); 182 } 183 184 out: 185 return err; 186 } 187 188 static void *xsk_copy_xdp_start(struct xdp_buff *from) 189 { 190 if (unlikely(xdp_data_meta_unsupported(from))) 191 return from->data; 192 else 193 return from->data_meta; 194 } 195 196 static u32 xsk_copy_xdp(void *to, void **from, u32 to_len, 197 u32 *from_len, skb_frag_t **frag, u32 rem) 198 { 199 u32 copied = 0; 200 201 while (1) { 202 u32 copy_len = min_t(u32, *from_len, to_len); 203 204 memcpy(to, *from, copy_len); 205 copied += copy_len; 206 if (rem == copied) 207 return copied; 208 209 if (*from_len == copy_len) { 210 *from = skb_frag_address(*frag); 211 *from_len = skb_frag_size((*frag)++); 212 } else { 213 *from += copy_len; 214 *from_len -= copy_len; 215 } 216 if (to_len == copy_len) 217 return copied; 218 219 to_len -= copy_len; 220 to += copy_len; 221 } 222 } 223 224 static int __xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len) 225 { 226 u32 frame_size = xsk_pool_get_rx_frame_size(xs->pool); 227 void *copy_from = xsk_copy_xdp_start(xdp), *copy_to; 228 u32 from_len, meta_len, rem, num_desc; 229 struct xdp_buff_xsk *xskb; 230 struct xdp_buff *xsk_xdp; 231 skb_frag_t *frag; 232 233 from_len = xdp->data_end - copy_from; 234 meta_len = xdp->data - copy_from; 235 rem = len + meta_len; 236 237 if (len <= frame_size && !xdp_buff_has_frags(xdp)) { 238 int err; 239 240 xsk_xdp = xsk_buff_alloc(xs->pool); 241 if (!xsk_xdp) { 242 xs->rx_dropped++; 243 return -ENOMEM; 244 } 245 memcpy(xsk_xdp->data - meta_len, copy_from, rem); 246 xskb = container_of(xsk_xdp, struct xdp_buff_xsk, xdp); 247 err = __xsk_rcv_zc(xs, xskb, len, 0); 248 if (err) { 249 xsk_buff_free(xsk_xdp); 250 return err; 251 } 252 253 return 0; 254 } 255 256 num_desc = (len - 1) / frame_size + 1; 257 258 if (!xsk_buff_can_alloc(xs->pool, num_desc)) { 259 xs->rx_dropped++; 260 return -ENOMEM; 261 } 262 if (xskq_prod_nb_free(xs->rx, num_desc) < num_desc) { 263 xs->rx_queue_full++; 264 return -ENOBUFS; 265 } 266 267 if (xdp_buff_has_frags(xdp)) { 268 struct skb_shared_info *sinfo; 269 270 sinfo = xdp_get_shared_info_from_buff(xdp); 271 frag = &sinfo->frags[0]; 272 } 273 274 do { 275 u32 to_len = frame_size + meta_len; 276 u32 copied; 277 278 xsk_xdp = xsk_buff_alloc(xs->pool); 279 copy_to = xsk_xdp->data - meta_len; 280 281 copied = xsk_copy_xdp(copy_to, ©_from, to_len, &from_len, &frag, rem); 282 rem -= copied; 283 284 xskb = container_of(xsk_xdp, struct xdp_buff_xsk, xdp); 285 __xsk_rcv_zc(xs, xskb, copied - meta_len, rem ? XDP_PKT_CONTD : 0); 286 meta_len = 0; 287 } while (rem); 288 289 return 0; 290 } 291 292 static bool xsk_tx_writeable(struct xdp_sock *xs) 293 { 294 if (xskq_cons_present_entries(xs->tx) > xs->tx->nentries / 2) 295 return false; 296 297 return true; 298 } 299 300 static bool xsk_is_bound(struct xdp_sock *xs) 301 { 302 if (READ_ONCE(xs->state) == XSK_BOUND) { 303 /* Matches smp_wmb() in bind(). */ 304 smp_rmb(); 305 return true; 306 } 307 return false; 308 } 309 310 static int xsk_rcv_check(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len) 311 { 312 if (!xsk_is_bound(xs)) 313 return -ENXIO; 314 315 if (xs->dev != xdp->rxq->dev || xs->queue_id != xdp->rxq->queue_index) 316 return -EINVAL; 317 318 if (len > xsk_pool_get_rx_frame_size(xs->pool) && !xs->sg) { 319 xs->rx_dropped++; 320 return -ENOSPC; 321 } 322 323 sk_mark_napi_id_once_xdp(&xs->sk, xdp); 324 return 0; 325 } 326 327 static void xsk_flush(struct xdp_sock *xs) 328 { 329 xskq_prod_submit(xs->rx); 330 __xskq_cons_release(xs->pool->fq); 331 sock_def_readable(&xs->sk); 332 } 333 334 int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp) 335 { 336 u32 len = xdp_get_buff_len(xdp); 337 int err; 338 339 spin_lock_bh(&xs->rx_lock); 340 err = xsk_rcv_check(xs, xdp, len); 341 if (!err) { 342 err = __xsk_rcv(xs, xdp, len); 343 xsk_flush(xs); 344 } 345 spin_unlock_bh(&xs->rx_lock); 346 return err; 347 } 348 349 static int xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp) 350 { 351 u32 len = xdp_get_buff_len(xdp); 352 int err; 353 354 err = xsk_rcv_check(xs, xdp, len); 355 if (err) 356 return err; 357 358 if (xdp->rxq->mem.type == MEM_TYPE_XSK_BUFF_POOL) { 359 len = xdp->data_end - xdp->data; 360 return xsk_rcv_zc(xs, xdp, len); 361 } 362 363 err = __xsk_rcv(xs, xdp, len); 364 if (!err) 365 xdp_return_buff(xdp); 366 return err; 367 } 368 369 int __xsk_map_redirect(struct xdp_sock *xs, struct xdp_buff *xdp) 370 { 371 struct list_head *flush_list = this_cpu_ptr(&xskmap_flush_list); 372 int err; 373 374 err = xsk_rcv(xs, xdp); 375 if (err) 376 return err; 377 378 if (!xs->flush_node.prev) 379 list_add(&xs->flush_node, flush_list); 380 381 return 0; 382 } 383 384 void __xsk_map_flush(void) 385 { 386 struct list_head *flush_list = this_cpu_ptr(&xskmap_flush_list); 387 struct xdp_sock *xs, *tmp; 388 389 list_for_each_entry_safe(xs, tmp, flush_list, flush_node) { 390 xsk_flush(xs); 391 __list_del_clearprev(&xs->flush_node); 392 } 393 } 394 395 #ifdef CONFIG_DEBUG_NET 396 bool xsk_map_check_flush(void) 397 { 398 if (list_empty(this_cpu_ptr(&xskmap_flush_list))) 399 return false; 400 __xsk_map_flush(); 401 return true; 402 } 403 #endif 404 405 void xsk_tx_completed(struct xsk_buff_pool *pool, u32 nb_entries) 406 { 407 xskq_prod_submit_n(pool->cq, nb_entries); 408 } 409 EXPORT_SYMBOL(xsk_tx_completed); 410 411 void xsk_tx_release(struct xsk_buff_pool *pool) 412 { 413 struct xdp_sock *xs; 414 415 rcu_read_lock(); 416 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) { 417 __xskq_cons_release(xs->tx); 418 if (xsk_tx_writeable(xs)) 419 xs->sk.sk_write_space(&xs->sk); 420 } 421 rcu_read_unlock(); 422 } 423 EXPORT_SYMBOL(xsk_tx_release); 424 425 bool xsk_tx_peek_desc(struct xsk_buff_pool *pool, struct xdp_desc *desc) 426 { 427 bool budget_exhausted = false; 428 struct xdp_sock *xs; 429 430 rcu_read_lock(); 431 again: 432 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) { 433 if (xs->tx_budget_spent >= MAX_PER_SOCKET_BUDGET) { 434 budget_exhausted = true; 435 continue; 436 } 437 438 if (!xskq_cons_peek_desc(xs->tx, desc, pool)) { 439 if (xskq_has_descs(xs->tx)) 440 xskq_cons_release(xs->tx); 441 continue; 442 } 443 444 xs->tx_budget_spent++; 445 446 /* This is the backpressure mechanism for the Tx path. 447 * Reserve space in the completion queue and only proceed 448 * if there is space in it. This avoids having to implement 449 * any buffering in the Tx path. 450 */ 451 if (xskq_prod_reserve_addr(pool->cq, desc->addr)) 452 goto out; 453 454 xskq_cons_release(xs->tx); 455 rcu_read_unlock(); 456 return true; 457 } 458 459 if (budget_exhausted) { 460 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) 461 xs->tx_budget_spent = 0; 462 463 budget_exhausted = false; 464 goto again; 465 } 466 467 out: 468 rcu_read_unlock(); 469 return false; 470 } 471 EXPORT_SYMBOL(xsk_tx_peek_desc); 472 473 static u32 xsk_tx_peek_release_fallback(struct xsk_buff_pool *pool, u32 max_entries) 474 { 475 struct xdp_desc *descs = pool->tx_descs; 476 u32 nb_pkts = 0; 477 478 while (nb_pkts < max_entries && xsk_tx_peek_desc(pool, &descs[nb_pkts])) 479 nb_pkts++; 480 481 xsk_tx_release(pool); 482 return nb_pkts; 483 } 484 485 u32 xsk_tx_peek_release_desc_batch(struct xsk_buff_pool *pool, u32 nb_pkts) 486 { 487 struct xdp_sock *xs; 488 489 rcu_read_lock(); 490 if (!list_is_singular(&pool->xsk_tx_list)) { 491 /* Fallback to the non-batched version */ 492 rcu_read_unlock(); 493 return xsk_tx_peek_release_fallback(pool, nb_pkts); 494 } 495 496 xs = list_first_or_null_rcu(&pool->xsk_tx_list, struct xdp_sock, tx_list); 497 if (!xs) { 498 nb_pkts = 0; 499 goto out; 500 } 501 502 nb_pkts = xskq_cons_nb_entries(xs->tx, nb_pkts); 503 504 /* This is the backpressure mechanism for the Tx path. Try to 505 * reserve space in the completion queue for all packets, but 506 * if there are fewer slots available, just process that many 507 * packets. This avoids having to implement any buffering in 508 * the Tx path. 509 */ 510 nb_pkts = xskq_prod_nb_free(pool->cq, nb_pkts); 511 if (!nb_pkts) 512 goto out; 513 514 nb_pkts = xskq_cons_read_desc_batch(xs->tx, pool, nb_pkts); 515 if (!nb_pkts) { 516 xs->tx->queue_empty_descs++; 517 goto out; 518 } 519 520 __xskq_cons_release(xs->tx); 521 xskq_prod_write_addr_batch(pool->cq, pool->tx_descs, nb_pkts); 522 xs->sk.sk_write_space(&xs->sk); 523 524 out: 525 rcu_read_unlock(); 526 return nb_pkts; 527 } 528 EXPORT_SYMBOL(xsk_tx_peek_release_desc_batch); 529 530 static int xsk_wakeup(struct xdp_sock *xs, u8 flags) 531 { 532 struct net_device *dev = xs->dev; 533 534 return dev->netdev_ops->ndo_xsk_wakeup(dev, xs->queue_id, flags); 535 } 536 537 static int xsk_cq_reserve_addr_locked(struct xdp_sock *xs, u64 addr) 538 { 539 unsigned long flags; 540 int ret; 541 542 spin_lock_irqsave(&xs->pool->cq_lock, flags); 543 ret = xskq_prod_reserve_addr(xs->pool->cq, addr); 544 spin_unlock_irqrestore(&xs->pool->cq_lock, flags); 545 546 return ret; 547 } 548 549 static void xsk_cq_submit_locked(struct xdp_sock *xs, u32 n) 550 { 551 unsigned long flags; 552 553 spin_lock_irqsave(&xs->pool->cq_lock, flags); 554 xskq_prod_submit_n(xs->pool->cq, n); 555 spin_unlock_irqrestore(&xs->pool->cq_lock, flags); 556 } 557 558 static void xsk_cq_cancel_locked(struct xdp_sock *xs, u32 n) 559 { 560 unsigned long flags; 561 562 spin_lock_irqsave(&xs->pool->cq_lock, flags); 563 xskq_prod_cancel_n(xs->pool->cq, n); 564 spin_unlock_irqrestore(&xs->pool->cq_lock, flags); 565 } 566 567 static u32 xsk_get_num_desc(struct sk_buff *skb) 568 { 569 return skb ? (long)skb_shinfo(skb)->destructor_arg : 0; 570 } 571 572 static void xsk_destruct_skb(struct sk_buff *skb) 573 { 574 struct xsk_tx_metadata_compl *compl = &skb_shinfo(skb)->xsk_meta; 575 576 if (compl->tx_timestamp) { 577 /* sw completion timestamp, not a real one */ 578 *compl->tx_timestamp = ktime_get_tai_fast_ns(); 579 } 580 581 xsk_cq_submit_locked(xdp_sk(skb->sk), xsk_get_num_desc(skb)); 582 sock_wfree(skb); 583 } 584 585 static void xsk_set_destructor_arg(struct sk_buff *skb) 586 { 587 long num = xsk_get_num_desc(xdp_sk(skb->sk)->skb) + 1; 588 589 skb_shinfo(skb)->destructor_arg = (void *)num; 590 } 591 592 static void xsk_consume_skb(struct sk_buff *skb) 593 { 594 struct xdp_sock *xs = xdp_sk(skb->sk); 595 596 skb->destructor = sock_wfree; 597 xsk_cq_cancel_locked(xs, xsk_get_num_desc(skb)); 598 /* Free skb without triggering the perf drop trace */ 599 consume_skb(skb); 600 xs->skb = NULL; 601 } 602 603 static void xsk_drop_skb(struct sk_buff *skb) 604 { 605 xdp_sk(skb->sk)->tx->invalid_descs += xsk_get_num_desc(skb); 606 xsk_consume_skb(skb); 607 } 608 609 static struct sk_buff *xsk_build_skb_zerocopy(struct xdp_sock *xs, 610 struct xdp_desc *desc) 611 { 612 struct xsk_buff_pool *pool = xs->pool; 613 u32 hr, len, ts, offset, copy, copied; 614 struct sk_buff *skb = xs->skb; 615 struct page *page; 616 void *buffer; 617 int err, i; 618 u64 addr; 619 620 if (!skb) { 621 hr = max(NET_SKB_PAD, L1_CACHE_ALIGN(xs->dev->needed_headroom)); 622 623 skb = sock_alloc_send_skb(&xs->sk, hr, 1, &err); 624 if (unlikely(!skb)) 625 return ERR_PTR(err); 626 627 skb_reserve(skb, hr); 628 } 629 630 addr = desc->addr; 631 len = desc->len; 632 ts = pool->unaligned ? len : pool->chunk_size; 633 634 buffer = xsk_buff_raw_get_data(pool, addr); 635 offset = offset_in_page(buffer); 636 addr = buffer - pool->addrs; 637 638 for (copied = 0, i = skb_shinfo(skb)->nr_frags; copied < len; i++) { 639 if (unlikely(i >= MAX_SKB_FRAGS)) 640 return ERR_PTR(-EOVERFLOW); 641 642 page = pool->umem->pgs[addr >> PAGE_SHIFT]; 643 get_page(page); 644 645 copy = min_t(u32, PAGE_SIZE - offset, len - copied); 646 skb_fill_page_desc(skb, i, page, offset, copy); 647 648 copied += copy; 649 addr += copy; 650 offset = 0; 651 } 652 653 skb->len += len; 654 skb->data_len += len; 655 skb->truesize += ts; 656 657 refcount_add(ts, &xs->sk.sk_wmem_alloc); 658 659 return skb; 660 } 661 662 static struct sk_buff *xsk_build_skb(struct xdp_sock *xs, 663 struct xdp_desc *desc) 664 { 665 struct xsk_tx_metadata *meta = NULL; 666 struct net_device *dev = xs->dev; 667 struct sk_buff *skb = xs->skb; 668 bool first_frag = false; 669 int err; 670 671 if (dev->priv_flags & IFF_TX_SKB_NO_LINEAR) { 672 skb = xsk_build_skb_zerocopy(xs, desc); 673 if (IS_ERR(skb)) { 674 err = PTR_ERR(skb); 675 goto free_err; 676 } 677 } else { 678 u32 hr, tr, len; 679 void *buffer; 680 681 buffer = xsk_buff_raw_get_data(xs->pool, desc->addr); 682 len = desc->len; 683 684 if (!skb) { 685 hr = max(NET_SKB_PAD, L1_CACHE_ALIGN(dev->needed_headroom)); 686 tr = dev->needed_tailroom; 687 skb = sock_alloc_send_skb(&xs->sk, hr + len + tr, 1, &err); 688 if (unlikely(!skb)) 689 goto free_err; 690 691 skb_reserve(skb, hr); 692 skb_put(skb, len); 693 694 err = skb_store_bits(skb, 0, buffer, len); 695 if (unlikely(err)) { 696 kfree_skb(skb); 697 goto free_err; 698 } 699 700 first_frag = true; 701 } else { 702 int nr_frags = skb_shinfo(skb)->nr_frags; 703 struct page *page; 704 u8 *vaddr; 705 706 if (unlikely(nr_frags == (MAX_SKB_FRAGS - 1) && xp_mb_desc(desc))) { 707 err = -EOVERFLOW; 708 goto free_err; 709 } 710 711 page = alloc_page(xs->sk.sk_allocation); 712 if (unlikely(!page)) { 713 err = -EAGAIN; 714 goto free_err; 715 } 716 717 vaddr = kmap_local_page(page); 718 memcpy(vaddr, buffer, len); 719 kunmap_local(vaddr); 720 721 skb_add_rx_frag(skb, nr_frags, page, 0, len, 0); 722 } 723 724 if (first_frag && desc->options & XDP_TX_METADATA) { 725 if (unlikely(xs->pool->tx_metadata_len == 0)) { 726 err = -EINVAL; 727 goto free_err; 728 } 729 730 meta = buffer - xs->pool->tx_metadata_len; 731 if (unlikely(!xsk_buff_valid_tx_metadata(meta))) { 732 err = -EINVAL; 733 goto free_err; 734 } 735 736 if (meta->flags & XDP_TXMD_FLAGS_CHECKSUM) { 737 if (unlikely(meta->request.csum_start + 738 meta->request.csum_offset + 739 sizeof(__sum16) > len)) { 740 err = -EINVAL; 741 goto free_err; 742 } 743 744 skb->csum_start = hr + meta->request.csum_start; 745 skb->csum_offset = meta->request.csum_offset; 746 skb->ip_summed = CHECKSUM_PARTIAL; 747 748 if (unlikely(xs->pool->tx_sw_csum)) { 749 err = skb_checksum_help(skb); 750 if (err) 751 goto free_err; 752 } 753 } 754 } 755 } 756 757 skb->dev = dev; 758 skb->priority = READ_ONCE(xs->sk.sk_priority); 759 skb->mark = READ_ONCE(xs->sk.sk_mark); 760 skb->destructor = xsk_destruct_skb; 761 xsk_tx_metadata_to_compl(meta, &skb_shinfo(skb)->xsk_meta); 762 xsk_set_destructor_arg(skb); 763 764 return skb; 765 766 free_err: 767 if (err == -EOVERFLOW) { 768 /* Drop the packet */ 769 xsk_set_destructor_arg(xs->skb); 770 xsk_drop_skb(xs->skb); 771 xskq_cons_release(xs->tx); 772 } else { 773 /* Let application retry */ 774 xsk_cq_cancel_locked(xs, 1); 775 } 776 777 return ERR_PTR(err); 778 } 779 780 static int __xsk_generic_xmit(struct sock *sk) 781 { 782 struct xdp_sock *xs = xdp_sk(sk); 783 u32 max_batch = TX_BATCH_SIZE; 784 bool sent_frame = false; 785 struct xdp_desc desc; 786 struct sk_buff *skb; 787 int err = 0; 788 789 mutex_lock(&xs->mutex); 790 791 /* Since we dropped the RCU read lock, the socket state might have changed. */ 792 if (unlikely(!xsk_is_bound(xs))) { 793 err = -ENXIO; 794 goto out; 795 } 796 797 if (xs->queue_id >= xs->dev->real_num_tx_queues) 798 goto out; 799 800 while (xskq_cons_peek_desc(xs->tx, &desc, xs->pool)) { 801 if (max_batch-- == 0) { 802 err = -EAGAIN; 803 goto out; 804 } 805 806 /* This is the backpressure mechanism for the Tx path. 807 * Reserve space in the completion queue and only proceed 808 * if there is space in it. This avoids having to implement 809 * any buffering in the Tx path. 810 */ 811 if (xsk_cq_reserve_addr_locked(xs, desc.addr)) 812 goto out; 813 814 skb = xsk_build_skb(xs, &desc); 815 if (IS_ERR(skb)) { 816 err = PTR_ERR(skb); 817 if (err != -EOVERFLOW) 818 goto out; 819 err = 0; 820 continue; 821 } 822 823 xskq_cons_release(xs->tx); 824 825 if (xp_mb_desc(&desc)) { 826 xs->skb = skb; 827 continue; 828 } 829 830 err = __dev_direct_xmit(skb, xs->queue_id); 831 if (err == NETDEV_TX_BUSY) { 832 /* Tell user-space to retry the send */ 833 xskq_cons_cancel_n(xs->tx, xsk_get_num_desc(skb)); 834 xsk_consume_skb(skb); 835 err = -EAGAIN; 836 goto out; 837 } 838 839 /* Ignore NET_XMIT_CN as packet might have been sent */ 840 if (err == NET_XMIT_DROP) { 841 /* SKB completed but not sent */ 842 err = -EBUSY; 843 xs->skb = NULL; 844 goto out; 845 } 846 847 sent_frame = true; 848 xs->skb = NULL; 849 } 850 851 if (xskq_has_descs(xs->tx)) { 852 if (xs->skb) 853 xsk_drop_skb(xs->skb); 854 xskq_cons_release(xs->tx); 855 } 856 857 out: 858 if (sent_frame) 859 if (xsk_tx_writeable(xs)) 860 sk->sk_write_space(sk); 861 862 mutex_unlock(&xs->mutex); 863 return err; 864 } 865 866 static int xsk_generic_xmit(struct sock *sk) 867 { 868 int ret; 869 870 /* Drop the RCU lock since the SKB path might sleep. */ 871 rcu_read_unlock(); 872 ret = __xsk_generic_xmit(sk); 873 /* Reaquire RCU lock before going into common code. */ 874 rcu_read_lock(); 875 876 return ret; 877 } 878 879 static bool xsk_no_wakeup(struct sock *sk) 880 { 881 #ifdef CONFIG_NET_RX_BUSY_POLL 882 /* Prefer busy-polling, skip the wakeup. */ 883 return READ_ONCE(sk->sk_prefer_busy_poll) && READ_ONCE(sk->sk_ll_usec) && 884 READ_ONCE(sk->sk_napi_id) >= MIN_NAPI_ID; 885 #else 886 return false; 887 #endif 888 } 889 890 static int xsk_check_common(struct xdp_sock *xs) 891 { 892 if (unlikely(!xsk_is_bound(xs))) 893 return -ENXIO; 894 if (unlikely(!(xs->dev->flags & IFF_UP))) 895 return -ENETDOWN; 896 897 return 0; 898 } 899 900 static int __xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len) 901 { 902 bool need_wait = !(m->msg_flags & MSG_DONTWAIT); 903 struct sock *sk = sock->sk; 904 struct xdp_sock *xs = xdp_sk(sk); 905 struct xsk_buff_pool *pool; 906 int err; 907 908 err = xsk_check_common(xs); 909 if (err) 910 return err; 911 if (unlikely(need_wait)) 912 return -EOPNOTSUPP; 913 if (unlikely(!xs->tx)) 914 return -ENOBUFS; 915 916 if (sk_can_busy_loop(sk)) { 917 if (xs->zc) 918 __sk_mark_napi_id_once(sk, xsk_pool_get_napi_id(xs->pool)); 919 sk_busy_loop(sk, 1); /* only support non-blocking sockets */ 920 } 921 922 if (xs->zc && xsk_no_wakeup(sk)) 923 return 0; 924 925 pool = xs->pool; 926 if (pool->cached_need_wakeup & XDP_WAKEUP_TX) { 927 if (xs->zc) 928 return xsk_wakeup(xs, XDP_WAKEUP_TX); 929 return xsk_generic_xmit(sk); 930 } 931 return 0; 932 } 933 934 static int xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len) 935 { 936 int ret; 937 938 rcu_read_lock(); 939 ret = __xsk_sendmsg(sock, m, total_len); 940 rcu_read_unlock(); 941 942 return ret; 943 } 944 945 static int __xsk_recvmsg(struct socket *sock, struct msghdr *m, size_t len, int flags) 946 { 947 bool need_wait = !(flags & MSG_DONTWAIT); 948 struct sock *sk = sock->sk; 949 struct xdp_sock *xs = xdp_sk(sk); 950 int err; 951 952 err = xsk_check_common(xs); 953 if (err) 954 return err; 955 if (unlikely(!xs->rx)) 956 return -ENOBUFS; 957 if (unlikely(need_wait)) 958 return -EOPNOTSUPP; 959 960 if (sk_can_busy_loop(sk)) 961 sk_busy_loop(sk, 1); /* only support non-blocking sockets */ 962 963 if (xsk_no_wakeup(sk)) 964 return 0; 965 966 if (xs->pool->cached_need_wakeup & XDP_WAKEUP_RX && xs->zc) 967 return xsk_wakeup(xs, XDP_WAKEUP_RX); 968 return 0; 969 } 970 971 static int xsk_recvmsg(struct socket *sock, struct msghdr *m, size_t len, int flags) 972 { 973 int ret; 974 975 rcu_read_lock(); 976 ret = __xsk_recvmsg(sock, m, len, flags); 977 rcu_read_unlock(); 978 979 return ret; 980 } 981 982 static __poll_t xsk_poll(struct file *file, struct socket *sock, 983 struct poll_table_struct *wait) 984 { 985 __poll_t mask = 0; 986 struct sock *sk = sock->sk; 987 struct xdp_sock *xs = xdp_sk(sk); 988 struct xsk_buff_pool *pool; 989 990 sock_poll_wait(file, sock, wait); 991 992 rcu_read_lock(); 993 if (xsk_check_common(xs)) 994 goto out; 995 996 pool = xs->pool; 997 998 if (pool->cached_need_wakeup) { 999 if (xs->zc) 1000 xsk_wakeup(xs, pool->cached_need_wakeup); 1001 else if (xs->tx) 1002 /* Poll needs to drive Tx also in copy mode */ 1003 xsk_generic_xmit(sk); 1004 } 1005 1006 if (xs->rx && !xskq_prod_is_empty(xs->rx)) 1007 mask |= EPOLLIN | EPOLLRDNORM; 1008 if (xs->tx && xsk_tx_writeable(xs)) 1009 mask |= EPOLLOUT | EPOLLWRNORM; 1010 out: 1011 rcu_read_unlock(); 1012 return mask; 1013 } 1014 1015 static int xsk_init_queue(u32 entries, struct xsk_queue **queue, 1016 bool umem_queue) 1017 { 1018 struct xsk_queue *q; 1019 1020 if (entries == 0 || *queue || !is_power_of_2(entries)) 1021 return -EINVAL; 1022 1023 q = xskq_create(entries, umem_queue); 1024 if (!q) 1025 return -ENOMEM; 1026 1027 /* Make sure queue is ready before it can be seen by others */ 1028 smp_wmb(); 1029 WRITE_ONCE(*queue, q); 1030 return 0; 1031 } 1032 1033 static void xsk_unbind_dev(struct xdp_sock *xs) 1034 { 1035 struct net_device *dev = xs->dev; 1036 1037 if (xs->state != XSK_BOUND) 1038 return; 1039 WRITE_ONCE(xs->state, XSK_UNBOUND); 1040 1041 /* Wait for driver to stop using the xdp socket. */ 1042 xp_del_xsk(xs->pool, xs); 1043 synchronize_net(); 1044 dev_put(dev); 1045 } 1046 1047 static struct xsk_map *xsk_get_map_list_entry(struct xdp_sock *xs, 1048 struct xdp_sock __rcu ***map_entry) 1049 { 1050 struct xsk_map *map = NULL; 1051 struct xsk_map_node *node; 1052 1053 *map_entry = NULL; 1054 1055 spin_lock_bh(&xs->map_list_lock); 1056 node = list_first_entry_or_null(&xs->map_list, struct xsk_map_node, 1057 node); 1058 if (node) { 1059 bpf_map_inc(&node->map->map); 1060 map = node->map; 1061 *map_entry = node->map_entry; 1062 } 1063 spin_unlock_bh(&xs->map_list_lock); 1064 return map; 1065 } 1066 1067 static void xsk_delete_from_maps(struct xdp_sock *xs) 1068 { 1069 /* This function removes the current XDP socket from all the 1070 * maps it resides in. We need to take extra care here, due to 1071 * the two locks involved. Each map has a lock synchronizing 1072 * updates to the entries, and each socket has a lock that 1073 * synchronizes access to the list of maps (map_list). For 1074 * deadlock avoidance the locks need to be taken in the order 1075 * "map lock"->"socket map list lock". We start off by 1076 * accessing the socket map list, and take a reference to the 1077 * map to guarantee existence between the 1078 * xsk_get_map_list_entry() and xsk_map_try_sock_delete() 1079 * calls. Then we ask the map to remove the socket, which 1080 * tries to remove the socket from the map. Note that there 1081 * might be updates to the map between 1082 * xsk_get_map_list_entry() and xsk_map_try_sock_delete(). 1083 */ 1084 struct xdp_sock __rcu **map_entry = NULL; 1085 struct xsk_map *map; 1086 1087 while ((map = xsk_get_map_list_entry(xs, &map_entry))) { 1088 xsk_map_try_sock_delete(map, xs, map_entry); 1089 bpf_map_put(&map->map); 1090 } 1091 } 1092 1093 static int xsk_release(struct socket *sock) 1094 { 1095 struct sock *sk = sock->sk; 1096 struct xdp_sock *xs = xdp_sk(sk); 1097 struct net *net; 1098 1099 if (!sk) 1100 return 0; 1101 1102 net = sock_net(sk); 1103 1104 if (xs->skb) 1105 xsk_drop_skb(xs->skb); 1106 1107 mutex_lock(&net->xdp.lock); 1108 sk_del_node_init_rcu(sk); 1109 mutex_unlock(&net->xdp.lock); 1110 1111 sock_prot_inuse_add(net, sk->sk_prot, -1); 1112 1113 xsk_delete_from_maps(xs); 1114 mutex_lock(&xs->mutex); 1115 xsk_unbind_dev(xs); 1116 mutex_unlock(&xs->mutex); 1117 1118 xskq_destroy(xs->rx); 1119 xskq_destroy(xs->tx); 1120 xskq_destroy(xs->fq_tmp); 1121 xskq_destroy(xs->cq_tmp); 1122 1123 sock_orphan(sk); 1124 sock->sk = NULL; 1125 1126 sock_put(sk); 1127 1128 return 0; 1129 } 1130 1131 static struct socket *xsk_lookup_xsk_from_fd(int fd) 1132 { 1133 struct socket *sock; 1134 int err; 1135 1136 sock = sockfd_lookup(fd, &err); 1137 if (!sock) 1138 return ERR_PTR(-ENOTSOCK); 1139 1140 if (sock->sk->sk_family != PF_XDP) { 1141 sockfd_put(sock); 1142 return ERR_PTR(-ENOPROTOOPT); 1143 } 1144 1145 return sock; 1146 } 1147 1148 static bool xsk_validate_queues(struct xdp_sock *xs) 1149 { 1150 return xs->fq_tmp && xs->cq_tmp; 1151 } 1152 1153 static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len) 1154 { 1155 struct sockaddr_xdp *sxdp = (struct sockaddr_xdp *)addr; 1156 struct sock *sk = sock->sk; 1157 struct xdp_sock *xs = xdp_sk(sk); 1158 struct net_device *dev; 1159 int bound_dev_if; 1160 u32 flags, qid; 1161 int err = 0; 1162 1163 if (addr_len < sizeof(struct sockaddr_xdp)) 1164 return -EINVAL; 1165 if (sxdp->sxdp_family != AF_XDP) 1166 return -EINVAL; 1167 1168 flags = sxdp->sxdp_flags; 1169 if (flags & ~(XDP_SHARED_UMEM | XDP_COPY | XDP_ZEROCOPY | 1170 XDP_USE_NEED_WAKEUP | XDP_USE_SG)) 1171 return -EINVAL; 1172 1173 bound_dev_if = READ_ONCE(sk->sk_bound_dev_if); 1174 if (bound_dev_if && bound_dev_if != sxdp->sxdp_ifindex) 1175 return -EINVAL; 1176 1177 rtnl_lock(); 1178 mutex_lock(&xs->mutex); 1179 if (xs->state != XSK_READY) { 1180 err = -EBUSY; 1181 goto out_release; 1182 } 1183 1184 dev = dev_get_by_index(sock_net(sk), sxdp->sxdp_ifindex); 1185 if (!dev) { 1186 err = -ENODEV; 1187 goto out_release; 1188 } 1189 1190 if (!xs->rx && !xs->tx) { 1191 err = -EINVAL; 1192 goto out_unlock; 1193 } 1194 1195 qid = sxdp->sxdp_queue_id; 1196 1197 if (flags & XDP_SHARED_UMEM) { 1198 struct xdp_sock *umem_xs; 1199 struct socket *sock; 1200 1201 if ((flags & XDP_COPY) || (flags & XDP_ZEROCOPY) || 1202 (flags & XDP_USE_NEED_WAKEUP) || (flags & XDP_USE_SG)) { 1203 /* Cannot specify flags for shared sockets. */ 1204 err = -EINVAL; 1205 goto out_unlock; 1206 } 1207 1208 if (xs->umem) { 1209 /* We have already our own. */ 1210 err = -EINVAL; 1211 goto out_unlock; 1212 } 1213 1214 sock = xsk_lookup_xsk_from_fd(sxdp->sxdp_shared_umem_fd); 1215 if (IS_ERR(sock)) { 1216 err = PTR_ERR(sock); 1217 goto out_unlock; 1218 } 1219 1220 umem_xs = xdp_sk(sock->sk); 1221 if (!xsk_is_bound(umem_xs)) { 1222 err = -EBADF; 1223 sockfd_put(sock); 1224 goto out_unlock; 1225 } 1226 1227 if (umem_xs->queue_id != qid || umem_xs->dev != dev) { 1228 /* Share the umem with another socket on another qid 1229 * and/or device. 1230 */ 1231 xs->pool = xp_create_and_assign_umem(xs, 1232 umem_xs->umem); 1233 if (!xs->pool) { 1234 err = -ENOMEM; 1235 sockfd_put(sock); 1236 goto out_unlock; 1237 } 1238 1239 err = xp_assign_dev_shared(xs->pool, umem_xs, dev, 1240 qid); 1241 if (err) { 1242 xp_destroy(xs->pool); 1243 xs->pool = NULL; 1244 sockfd_put(sock); 1245 goto out_unlock; 1246 } 1247 } else { 1248 /* Share the buffer pool with the other socket. */ 1249 if (xs->fq_tmp || xs->cq_tmp) { 1250 /* Do not allow setting your own fq or cq. */ 1251 err = -EINVAL; 1252 sockfd_put(sock); 1253 goto out_unlock; 1254 } 1255 1256 xp_get_pool(umem_xs->pool); 1257 xs->pool = umem_xs->pool; 1258 1259 /* If underlying shared umem was created without Tx 1260 * ring, allocate Tx descs array that Tx batching API 1261 * utilizes 1262 */ 1263 if (xs->tx && !xs->pool->tx_descs) { 1264 err = xp_alloc_tx_descs(xs->pool, xs); 1265 if (err) { 1266 xp_put_pool(xs->pool); 1267 xs->pool = NULL; 1268 sockfd_put(sock); 1269 goto out_unlock; 1270 } 1271 } 1272 } 1273 1274 xdp_get_umem(umem_xs->umem); 1275 WRITE_ONCE(xs->umem, umem_xs->umem); 1276 sockfd_put(sock); 1277 } else if (!xs->umem || !xsk_validate_queues(xs)) { 1278 err = -EINVAL; 1279 goto out_unlock; 1280 } else { 1281 /* This xsk has its own umem. */ 1282 xs->pool = xp_create_and_assign_umem(xs, xs->umem); 1283 if (!xs->pool) { 1284 err = -ENOMEM; 1285 goto out_unlock; 1286 } 1287 1288 err = xp_assign_dev(xs->pool, dev, qid, flags); 1289 if (err) { 1290 xp_destroy(xs->pool); 1291 xs->pool = NULL; 1292 goto out_unlock; 1293 } 1294 } 1295 1296 /* FQ and CQ are now owned by the buffer pool and cleaned up with it. */ 1297 xs->fq_tmp = NULL; 1298 xs->cq_tmp = NULL; 1299 1300 xs->dev = dev; 1301 xs->zc = xs->umem->zc; 1302 xs->sg = !!(xs->umem->flags & XDP_UMEM_SG_FLAG); 1303 xs->queue_id = qid; 1304 xp_add_xsk(xs->pool, xs); 1305 1306 out_unlock: 1307 if (err) { 1308 dev_put(dev); 1309 } else { 1310 /* Matches smp_rmb() in bind() for shared umem 1311 * sockets, and xsk_is_bound(). 1312 */ 1313 smp_wmb(); 1314 WRITE_ONCE(xs->state, XSK_BOUND); 1315 } 1316 out_release: 1317 mutex_unlock(&xs->mutex); 1318 rtnl_unlock(); 1319 return err; 1320 } 1321 1322 struct xdp_umem_reg_v1 { 1323 __u64 addr; /* Start of packet data area */ 1324 __u64 len; /* Length of packet data area */ 1325 __u32 chunk_size; 1326 __u32 headroom; 1327 }; 1328 1329 struct xdp_umem_reg_v2 { 1330 __u64 addr; /* Start of packet data area */ 1331 __u64 len; /* Length of packet data area */ 1332 __u32 chunk_size; 1333 __u32 headroom; 1334 __u32 flags; 1335 }; 1336 1337 static int xsk_setsockopt(struct socket *sock, int level, int optname, 1338 sockptr_t optval, unsigned int optlen) 1339 { 1340 struct sock *sk = sock->sk; 1341 struct xdp_sock *xs = xdp_sk(sk); 1342 int err; 1343 1344 if (level != SOL_XDP) 1345 return -ENOPROTOOPT; 1346 1347 switch (optname) { 1348 case XDP_RX_RING: 1349 case XDP_TX_RING: 1350 { 1351 struct xsk_queue **q; 1352 int entries; 1353 1354 if (optlen < sizeof(entries)) 1355 return -EINVAL; 1356 if (copy_from_sockptr(&entries, optval, sizeof(entries))) 1357 return -EFAULT; 1358 1359 mutex_lock(&xs->mutex); 1360 if (xs->state != XSK_READY) { 1361 mutex_unlock(&xs->mutex); 1362 return -EBUSY; 1363 } 1364 q = (optname == XDP_TX_RING) ? &xs->tx : &xs->rx; 1365 err = xsk_init_queue(entries, q, false); 1366 if (!err && optname == XDP_TX_RING) 1367 /* Tx needs to be explicitly woken up the first time */ 1368 xs->tx->ring->flags |= XDP_RING_NEED_WAKEUP; 1369 mutex_unlock(&xs->mutex); 1370 return err; 1371 } 1372 case XDP_UMEM_REG: 1373 { 1374 size_t mr_size = sizeof(struct xdp_umem_reg); 1375 struct xdp_umem_reg mr = {}; 1376 struct xdp_umem *umem; 1377 1378 if (optlen < sizeof(struct xdp_umem_reg_v1)) 1379 return -EINVAL; 1380 else if (optlen < sizeof(struct xdp_umem_reg_v2)) 1381 mr_size = sizeof(struct xdp_umem_reg_v1); 1382 else if (optlen < sizeof(mr)) 1383 mr_size = sizeof(struct xdp_umem_reg_v2); 1384 1385 if (copy_from_sockptr(&mr, optval, mr_size)) 1386 return -EFAULT; 1387 1388 mutex_lock(&xs->mutex); 1389 if (xs->state != XSK_READY || xs->umem) { 1390 mutex_unlock(&xs->mutex); 1391 return -EBUSY; 1392 } 1393 1394 umem = xdp_umem_create(&mr); 1395 if (IS_ERR(umem)) { 1396 mutex_unlock(&xs->mutex); 1397 return PTR_ERR(umem); 1398 } 1399 1400 /* Make sure umem is ready before it can be seen by others */ 1401 smp_wmb(); 1402 WRITE_ONCE(xs->umem, umem); 1403 mutex_unlock(&xs->mutex); 1404 return 0; 1405 } 1406 case XDP_UMEM_FILL_RING: 1407 case XDP_UMEM_COMPLETION_RING: 1408 { 1409 struct xsk_queue **q; 1410 int entries; 1411 1412 if (copy_from_sockptr(&entries, optval, sizeof(entries))) 1413 return -EFAULT; 1414 1415 mutex_lock(&xs->mutex); 1416 if (xs->state != XSK_READY) { 1417 mutex_unlock(&xs->mutex); 1418 return -EBUSY; 1419 } 1420 1421 q = (optname == XDP_UMEM_FILL_RING) ? &xs->fq_tmp : 1422 &xs->cq_tmp; 1423 err = xsk_init_queue(entries, q, true); 1424 mutex_unlock(&xs->mutex); 1425 return err; 1426 } 1427 default: 1428 break; 1429 } 1430 1431 return -ENOPROTOOPT; 1432 } 1433 1434 static void xsk_enter_rxtx_offsets(struct xdp_ring_offset_v1 *ring) 1435 { 1436 ring->producer = offsetof(struct xdp_rxtx_ring, ptrs.producer); 1437 ring->consumer = offsetof(struct xdp_rxtx_ring, ptrs.consumer); 1438 ring->desc = offsetof(struct xdp_rxtx_ring, desc); 1439 } 1440 1441 static void xsk_enter_umem_offsets(struct xdp_ring_offset_v1 *ring) 1442 { 1443 ring->producer = offsetof(struct xdp_umem_ring, ptrs.producer); 1444 ring->consumer = offsetof(struct xdp_umem_ring, ptrs.consumer); 1445 ring->desc = offsetof(struct xdp_umem_ring, desc); 1446 } 1447 1448 struct xdp_statistics_v1 { 1449 __u64 rx_dropped; 1450 __u64 rx_invalid_descs; 1451 __u64 tx_invalid_descs; 1452 }; 1453 1454 static int xsk_getsockopt(struct socket *sock, int level, int optname, 1455 char __user *optval, int __user *optlen) 1456 { 1457 struct sock *sk = sock->sk; 1458 struct xdp_sock *xs = xdp_sk(sk); 1459 int len; 1460 1461 if (level != SOL_XDP) 1462 return -ENOPROTOOPT; 1463 1464 if (get_user(len, optlen)) 1465 return -EFAULT; 1466 if (len < 0) 1467 return -EINVAL; 1468 1469 switch (optname) { 1470 case XDP_STATISTICS: 1471 { 1472 struct xdp_statistics stats = {}; 1473 bool extra_stats = true; 1474 size_t stats_size; 1475 1476 if (len < sizeof(struct xdp_statistics_v1)) { 1477 return -EINVAL; 1478 } else if (len < sizeof(stats)) { 1479 extra_stats = false; 1480 stats_size = sizeof(struct xdp_statistics_v1); 1481 } else { 1482 stats_size = sizeof(stats); 1483 } 1484 1485 mutex_lock(&xs->mutex); 1486 stats.rx_dropped = xs->rx_dropped; 1487 if (extra_stats) { 1488 stats.rx_ring_full = xs->rx_queue_full; 1489 stats.rx_fill_ring_empty_descs = 1490 xs->pool ? xskq_nb_queue_empty_descs(xs->pool->fq) : 0; 1491 stats.tx_ring_empty_descs = xskq_nb_queue_empty_descs(xs->tx); 1492 } else { 1493 stats.rx_dropped += xs->rx_queue_full; 1494 } 1495 stats.rx_invalid_descs = xskq_nb_invalid_descs(xs->rx); 1496 stats.tx_invalid_descs = xskq_nb_invalid_descs(xs->tx); 1497 mutex_unlock(&xs->mutex); 1498 1499 if (copy_to_user(optval, &stats, stats_size)) 1500 return -EFAULT; 1501 if (put_user(stats_size, optlen)) 1502 return -EFAULT; 1503 1504 return 0; 1505 } 1506 case XDP_MMAP_OFFSETS: 1507 { 1508 struct xdp_mmap_offsets off; 1509 struct xdp_mmap_offsets_v1 off_v1; 1510 bool flags_supported = true; 1511 void *to_copy; 1512 1513 if (len < sizeof(off_v1)) 1514 return -EINVAL; 1515 else if (len < sizeof(off)) 1516 flags_supported = false; 1517 1518 if (flags_supported) { 1519 /* xdp_ring_offset is identical to xdp_ring_offset_v1 1520 * except for the flags field added to the end. 1521 */ 1522 xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *) 1523 &off.rx); 1524 xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *) 1525 &off.tx); 1526 xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *) 1527 &off.fr); 1528 xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *) 1529 &off.cr); 1530 off.rx.flags = offsetof(struct xdp_rxtx_ring, 1531 ptrs.flags); 1532 off.tx.flags = offsetof(struct xdp_rxtx_ring, 1533 ptrs.flags); 1534 off.fr.flags = offsetof(struct xdp_umem_ring, 1535 ptrs.flags); 1536 off.cr.flags = offsetof(struct xdp_umem_ring, 1537 ptrs.flags); 1538 1539 len = sizeof(off); 1540 to_copy = &off; 1541 } else { 1542 xsk_enter_rxtx_offsets(&off_v1.rx); 1543 xsk_enter_rxtx_offsets(&off_v1.tx); 1544 xsk_enter_umem_offsets(&off_v1.fr); 1545 xsk_enter_umem_offsets(&off_v1.cr); 1546 1547 len = sizeof(off_v1); 1548 to_copy = &off_v1; 1549 } 1550 1551 if (copy_to_user(optval, to_copy, len)) 1552 return -EFAULT; 1553 if (put_user(len, optlen)) 1554 return -EFAULT; 1555 1556 return 0; 1557 } 1558 case XDP_OPTIONS: 1559 { 1560 struct xdp_options opts = {}; 1561 1562 if (len < sizeof(opts)) 1563 return -EINVAL; 1564 1565 mutex_lock(&xs->mutex); 1566 if (xs->zc) 1567 opts.flags |= XDP_OPTIONS_ZEROCOPY; 1568 mutex_unlock(&xs->mutex); 1569 1570 len = sizeof(opts); 1571 if (copy_to_user(optval, &opts, len)) 1572 return -EFAULT; 1573 if (put_user(len, optlen)) 1574 return -EFAULT; 1575 1576 return 0; 1577 } 1578 default: 1579 break; 1580 } 1581 1582 return -EOPNOTSUPP; 1583 } 1584 1585 static int xsk_mmap(struct file *file, struct socket *sock, 1586 struct vm_area_struct *vma) 1587 { 1588 loff_t offset = (loff_t)vma->vm_pgoff << PAGE_SHIFT; 1589 unsigned long size = vma->vm_end - vma->vm_start; 1590 struct xdp_sock *xs = xdp_sk(sock->sk); 1591 int state = READ_ONCE(xs->state); 1592 struct xsk_queue *q = NULL; 1593 1594 if (state != XSK_READY && state != XSK_BOUND) 1595 return -EBUSY; 1596 1597 if (offset == XDP_PGOFF_RX_RING) { 1598 q = READ_ONCE(xs->rx); 1599 } else if (offset == XDP_PGOFF_TX_RING) { 1600 q = READ_ONCE(xs->tx); 1601 } else { 1602 /* Matches the smp_wmb() in XDP_UMEM_REG */ 1603 smp_rmb(); 1604 if (offset == XDP_UMEM_PGOFF_FILL_RING) 1605 q = state == XSK_READY ? READ_ONCE(xs->fq_tmp) : 1606 READ_ONCE(xs->pool->fq); 1607 else if (offset == XDP_UMEM_PGOFF_COMPLETION_RING) 1608 q = state == XSK_READY ? READ_ONCE(xs->cq_tmp) : 1609 READ_ONCE(xs->pool->cq); 1610 } 1611 1612 if (!q) 1613 return -EINVAL; 1614 1615 /* Matches the smp_wmb() in xsk_init_queue */ 1616 smp_rmb(); 1617 if (size > q->ring_vmalloc_size) 1618 return -EINVAL; 1619 1620 return remap_vmalloc_range(vma, q->ring, 0); 1621 } 1622 1623 static int xsk_notifier(struct notifier_block *this, 1624 unsigned long msg, void *ptr) 1625 { 1626 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1627 struct net *net = dev_net(dev); 1628 struct sock *sk; 1629 1630 switch (msg) { 1631 case NETDEV_UNREGISTER: 1632 mutex_lock(&net->xdp.lock); 1633 sk_for_each(sk, &net->xdp.list) { 1634 struct xdp_sock *xs = xdp_sk(sk); 1635 1636 mutex_lock(&xs->mutex); 1637 if (xs->dev == dev) { 1638 sk->sk_err = ENETDOWN; 1639 if (!sock_flag(sk, SOCK_DEAD)) 1640 sk_error_report(sk); 1641 1642 xsk_unbind_dev(xs); 1643 1644 /* Clear device references. */ 1645 xp_clear_dev(xs->pool); 1646 } 1647 mutex_unlock(&xs->mutex); 1648 } 1649 mutex_unlock(&net->xdp.lock); 1650 break; 1651 } 1652 return NOTIFY_DONE; 1653 } 1654 1655 static struct proto xsk_proto = { 1656 .name = "XDP", 1657 .owner = THIS_MODULE, 1658 .obj_size = sizeof(struct xdp_sock), 1659 }; 1660 1661 static const struct proto_ops xsk_proto_ops = { 1662 .family = PF_XDP, 1663 .owner = THIS_MODULE, 1664 .release = xsk_release, 1665 .bind = xsk_bind, 1666 .connect = sock_no_connect, 1667 .socketpair = sock_no_socketpair, 1668 .accept = sock_no_accept, 1669 .getname = sock_no_getname, 1670 .poll = xsk_poll, 1671 .ioctl = sock_no_ioctl, 1672 .listen = sock_no_listen, 1673 .shutdown = sock_no_shutdown, 1674 .setsockopt = xsk_setsockopt, 1675 .getsockopt = xsk_getsockopt, 1676 .sendmsg = xsk_sendmsg, 1677 .recvmsg = xsk_recvmsg, 1678 .mmap = xsk_mmap, 1679 }; 1680 1681 static void xsk_destruct(struct sock *sk) 1682 { 1683 struct xdp_sock *xs = xdp_sk(sk); 1684 1685 if (!sock_flag(sk, SOCK_DEAD)) 1686 return; 1687 1688 if (!xp_put_pool(xs->pool)) 1689 xdp_put_umem(xs->umem, !xs->pool); 1690 } 1691 1692 static int xsk_create(struct net *net, struct socket *sock, int protocol, 1693 int kern) 1694 { 1695 struct xdp_sock *xs; 1696 struct sock *sk; 1697 1698 if (!ns_capable(net->user_ns, CAP_NET_RAW)) 1699 return -EPERM; 1700 if (sock->type != SOCK_RAW) 1701 return -ESOCKTNOSUPPORT; 1702 1703 if (protocol) 1704 return -EPROTONOSUPPORT; 1705 1706 sock->state = SS_UNCONNECTED; 1707 1708 sk = sk_alloc(net, PF_XDP, GFP_KERNEL, &xsk_proto, kern); 1709 if (!sk) 1710 return -ENOBUFS; 1711 1712 sock->ops = &xsk_proto_ops; 1713 1714 sock_init_data(sock, sk); 1715 1716 sk->sk_family = PF_XDP; 1717 1718 sk->sk_destruct = xsk_destruct; 1719 1720 sock_set_flag(sk, SOCK_RCU_FREE); 1721 1722 xs = xdp_sk(sk); 1723 xs->state = XSK_READY; 1724 mutex_init(&xs->mutex); 1725 spin_lock_init(&xs->rx_lock); 1726 1727 INIT_LIST_HEAD(&xs->map_list); 1728 spin_lock_init(&xs->map_list_lock); 1729 1730 mutex_lock(&net->xdp.lock); 1731 sk_add_node_rcu(sk, &net->xdp.list); 1732 mutex_unlock(&net->xdp.lock); 1733 1734 sock_prot_inuse_add(net, &xsk_proto, 1); 1735 1736 return 0; 1737 } 1738 1739 static const struct net_proto_family xsk_family_ops = { 1740 .family = PF_XDP, 1741 .create = xsk_create, 1742 .owner = THIS_MODULE, 1743 }; 1744 1745 static struct notifier_block xsk_netdev_notifier = { 1746 .notifier_call = xsk_notifier, 1747 }; 1748 1749 static int __net_init xsk_net_init(struct net *net) 1750 { 1751 mutex_init(&net->xdp.lock); 1752 INIT_HLIST_HEAD(&net->xdp.list); 1753 return 0; 1754 } 1755 1756 static void __net_exit xsk_net_exit(struct net *net) 1757 { 1758 WARN_ON_ONCE(!hlist_empty(&net->xdp.list)); 1759 } 1760 1761 static struct pernet_operations xsk_net_ops = { 1762 .init = xsk_net_init, 1763 .exit = xsk_net_exit, 1764 }; 1765 1766 static int __init xsk_init(void) 1767 { 1768 int err, cpu; 1769 1770 err = proto_register(&xsk_proto, 0 /* no slab */); 1771 if (err) 1772 goto out; 1773 1774 err = sock_register(&xsk_family_ops); 1775 if (err) 1776 goto out_proto; 1777 1778 err = register_pernet_subsys(&xsk_net_ops); 1779 if (err) 1780 goto out_sk; 1781 1782 err = register_netdevice_notifier(&xsk_netdev_notifier); 1783 if (err) 1784 goto out_pernet; 1785 1786 for_each_possible_cpu(cpu) 1787 INIT_LIST_HEAD(&per_cpu(xskmap_flush_list, cpu)); 1788 return 0; 1789 1790 out_pernet: 1791 unregister_pernet_subsys(&xsk_net_ops); 1792 out_sk: 1793 sock_unregister(PF_XDP); 1794 out_proto: 1795 proto_unregister(&xsk_proto); 1796 out: 1797 return err; 1798 } 1799 1800 fs_initcall(xsk_init); 1801