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