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); 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, 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 goto err; 181 list_del(&pos->xskb_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 struct list_head *flush_list = bpf_net_ctx_get_xskmap_flush_list(); 374 int err; 375 376 err = xsk_rcv(xs, xdp); 377 if (err) 378 return err; 379 380 if (!xs->flush_node.prev) 381 list_add(&xs->flush_node, flush_list); 382 383 return 0; 384 } 385 386 void __xsk_map_flush(void) 387 { 388 struct list_head *flush_list = bpf_net_ctx_get_xskmap_flush_list(); 389 struct xdp_sock *xs, *tmp; 390 391 list_for_each_entry_safe(xs, tmp, flush_list, flush_node) { 392 xsk_flush(xs); 393 __list_del_clearprev(&xs->flush_node); 394 } 395 } 396 397 #ifdef CONFIG_DEBUG_NET 398 bool xsk_map_check_flush(void) 399 { 400 if (list_empty(bpf_net_ctx_get_xskmap_flush_list())) 401 return false; 402 __xsk_map_flush(); 403 return true; 404 } 405 #endif 406 407 void xsk_tx_completed(struct xsk_buff_pool *pool, u32 nb_entries) 408 { 409 xskq_prod_submit_n(pool->cq, nb_entries); 410 } 411 EXPORT_SYMBOL(xsk_tx_completed); 412 413 void xsk_tx_release(struct xsk_buff_pool *pool) 414 { 415 struct xdp_sock *xs; 416 417 rcu_read_lock(); 418 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) { 419 __xskq_cons_release(xs->tx); 420 if (xsk_tx_writeable(xs)) 421 xs->sk.sk_write_space(&xs->sk); 422 } 423 rcu_read_unlock(); 424 } 425 EXPORT_SYMBOL(xsk_tx_release); 426 427 bool xsk_tx_peek_desc(struct xsk_buff_pool *pool, struct xdp_desc *desc) 428 { 429 bool budget_exhausted = false; 430 struct xdp_sock *xs; 431 432 rcu_read_lock(); 433 again: 434 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) { 435 if (xs->tx_budget_spent >= MAX_PER_SOCKET_BUDGET) { 436 budget_exhausted = true; 437 continue; 438 } 439 440 if (!xskq_cons_peek_desc(xs->tx, desc, pool)) { 441 if (xskq_has_descs(xs->tx)) 442 xskq_cons_release(xs->tx); 443 continue; 444 } 445 446 xs->tx_budget_spent++; 447 448 /* This is the backpressure mechanism for the Tx path. 449 * Reserve space in the completion queue and only proceed 450 * if there is space in it. This avoids having to implement 451 * any buffering in the Tx path. 452 */ 453 if (xskq_prod_reserve_addr(pool->cq, desc->addr)) 454 goto out; 455 456 xskq_cons_release(xs->tx); 457 rcu_read_unlock(); 458 return true; 459 } 460 461 if (budget_exhausted) { 462 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) 463 xs->tx_budget_spent = 0; 464 465 budget_exhausted = false; 466 goto again; 467 } 468 469 out: 470 rcu_read_unlock(); 471 return false; 472 } 473 EXPORT_SYMBOL(xsk_tx_peek_desc); 474 475 static u32 xsk_tx_peek_release_fallback(struct xsk_buff_pool *pool, u32 max_entries) 476 { 477 struct xdp_desc *descs = pool->tx_descs; 478 u32 nb_pkts = 0; 479 480 while (nb_pkts < max_entries && xsk_tx_peek_desc(pool, &descs[nb_pkts])) 481 nb_pkts++; 482 483 xsk_tx_release(pool); 484 return nb_pkts; 485 } 486 487 u32 xsk_tx_peek_release_desc_batch(struct xsk_buff_pool *pool, u32 nb_pkts) 488 { 489 struct xdp_sock *xs; 490 491 rcu_read_lock(); 492 if (!list_is_singular(&pool->xsk_tx_list)) { 493 /* Fallback to the non-batched version */ 494 rcu_read_unlock(); 495 return xsk_tx_peek_release_fallback(pool, nb_pkts); 496 } 497 498 xs = list_first_or_null_rcu(&pool->xsk_tx_list, struct xdp_sock, tx_list); 499 if (!xs) { 500 nb_pkts = 0; 501 goto out; 502 } 503 504 nb_pkts = xskq_cons_nb_entries(xs->tx, nb_pkts); 505 506 /* This is the backpressure mechanism for the Tx path. Try to 507 * reserve space in the completion queue for all packets, but 508 * if there are fewer slots available, just process that many 509 * packets. This avoids having to implement any buffering in 510 * the Tx path. 511 */ 512 nb_pkts = xskq_prod_nb_free(pool->cq, nb_pkts); 513 if (!nb_pkts) 514 goto out; 515 516 nb_pkts = xskq_cons_read_desc_batch(xs->tx, pool, nb_pkts); 517 if (!nb_pkts) { 518 xs->tx->queue_empty_descs++; 519 goto out; 520 } 521 522 __xskq_cons_release(xs->tx); 523 xskq_prod_write_addr_batch(pool->cq, pool->tx_descs, nb_pkts); 524 xs->sk.sk_write_space(&xs->sk); 525 526 out: 527 rcu_read_unlock(); 528 return nb_pkts; 529 } 530 EXPORT_SYMBOL(xsk_tx_peek_release_desc_batch); 531 532 static int xsk_wakeup(struct xdp_sock *xs, u8 flags) 533 { 534 struct net_device *dev = xs->dev; 535 536 return dev->netdev_ops->ndo_xsk_wakeup(dev, xs->queue_id, flags); 537 } 538 539 static int xsk_cq_reserve_addr_locked(struct xdp_sock *xs, u64 addr) 540 { 541 unsigned long flags; 542 int ret; 543 544 spin_lock_irqsave(&xs->pool->cq_lock, flags); 545 ret = xskq_prod_reserve_addr(xs->pool->cq, addr); 546 spin_unlock_irqrestore(&xs->pool->cq_lock, flags); 547 548 return ret; 549 } 550 551 static void xsk_cq_submit_locked(struct xdp_sock *xs, u32 n) 552 { 553 unsigned long flags; 554 555 spin_lock_irqsave(&xs->pool->cq_lock, flags); 556 xskq_prod_submit_n(xs->pool->cq, n); 557 spin_unlock_irqrestore(&xs->pool->cq_lock, flags); 558 } 559 560 static void xsk_cq_cancel_locked(struct xdp_sock *xs, u32 n) 561 { 562 unsigned long flags; 563 564 spin_lock_irqsave(&xs->pool->cq_lock, flags); 565 xskq_prod_cancel_n(xs->pool->cq, n); 566 spin_unlock_irqrestore(&xs->pool->cq_lock, flags); 567 } 568 569 static u32 xsk_get_num_desc(struct sk_buff *skb) 570 { 571 return skb ? (long)skb_shinfo(skb)->destructor_arg : 0; 572 } 573 574 static void xsk_destruct_skb(struct sk_buff *skb) 575 { 576 struct xsk_tx_metadata_compl *compl = &skb_shinfo(skb)->xsk_meta; 577 578 if (compl->tx_timestamp) { 579 /* sw completion timestamp, not a real one */ 580 *compl->tx_timestamp = ktime_get_tai_fast_ns(); 581 } 582 583 xsk_cq_submit_locked(xdp_sk(skb->sk), xsk_get_num_desc(skb)); 584 sock_wfree(skb); 585 } 586 587 static void xsk_set_destructor_arg(struct sk_buff *skb) 588 { 589 long num = xsk_get_num_desc(xdp_sk(skb->sk)->skb) + 1; 590 591 skb_shinfo(skb)->destructor_arg = (void *)num; 592 } 593 594 static void xsk_consume_skb(struct sk_buff *skb) 595 { 596 struct xdp_sock *xs = xdp_sk(skb->sk); 597 598 skb->destructor = sock_wfree; 599 xsk_cq_cancel_locked(xs, xsk_get_num_desc(skb)); 600 /* Free skb without triggering the perf drop trace */ 601 consume_skb(skb); 602 xs->skb = NULL; 603 } 604 605 static void xsk_drop_skb(struct sk_buff *skb) 606 { 607 xdp_sk(skb->sk)->tx->invalid_descs += xsk_get_num_desc(skb); 608 xsk_consume_skb(skb); 609 } 610 611 static struct sk_buff *xsk_build_skb_zerocopy(struct xdp_sock *xs, 612 struct xdp_desc *desc) 613 { 614 struct xsk_buff_pool *pool = xs->pool; 615 u32 hr, len, ts, offset, copy, copied; 616 struct sk_buff *skb = xs->skb; 617 struct page *page; 618 void *buffer; 619 int err, i; 620 u64 addr; 621 622 if (!skb) { 623 hr = max(NET_SKB_PAD, L1_CACHE_ALIGN(xs->dev->needed_headroom)); 624 625 skb = sock_alloc_send_skb(&xs->sk, hr, 1, &err); 626 if (unlikely(!skb)) 627 return ERR_PTR(err); 628 629 skb_reserve(skb, hr); 630 } 631 632 addr = desc->addr; 633 len = desc->len; 634 ts = pool->unaligned ? len : pool->chunk_size; 635 636 buffer = xsk_buff_raw_get_data(pool, addr); 637 offset = offset_in_page(buffer); 638 addr = buffer - pool->addrs; 639 640 for (copied = 0, i = skb_shinfo(skb)->nr_frags; copied < len; i++) { 641 if (unlikely(i >= MAX_SKB_FRAGS)) 642 return ERR_PTR(-EOVERFLOW); 643 644 page = pool->umem->pgs[addr >> PAGE_SHIFT]; 645 get_page(page); 646 647 copy = min_t(u32, PAGE_SIZE - offset, len - copied); 648 skb_fill_page_desc(skb, i, page, offset, copy); 649 650 copied += copy; 651 addr += copy; 652 offset = 0; 653 } 654 655 skb->len += len; 656 skb->data_len += len; 657 skb->truesize += ts; 658 659 refcount_add(ts, &xs->sk.sk_wmem_alloc); 660 661 return skb; 662 } 663 664 static struct sk_buff *xsk_build_skb(struct xdp_sock *xs, 665 struct xdp_desc *desc) 666 { 667 struct xsk_tx_metadata *meta = NULL; 668 struct net_device *dev = xs->dev; 669 struct sk_buff *skb = xs->skb; 670 bool first_frag = false; 671 int err; 672 673 if (dev->priv_flags & IFF_TX_SKB_NO_LINEAR) { 674 skb = xsk_build_skb_zerocopy(xs, desc); 675 if (IS_ERR(skb)) { 676 err = PTR_ERR(skb); 677 goto free_err; 678 } 679 } else { 680 u32 hr, tr, len; 681 void *buffer; 682 683 buffer = xsk_buff_raw_get_data(xs->pool, desc->addr); 684 len = desc->len; 685 686 if (!skb) { 687 hr = max(NET_SKB_PAD, L1_CACHE_ALIGN(dev->needed_headroom)); 688 tr = dev->needed_tailroom; 689 skb = sock_alloc_send_skb(&xs->sk, hr + len + tr, 1, &err); 690 if (unlikely(!skb)) 691 goto free_err; 692 693 skb_reserve(skb, hr); 694 skb_put(skb, len); 695 696 err = skb_store_bits(skb, 0, buffer, len); 697 if (unlikely(err)) { 698 kfree_skb(skb); 699 goto free_err; 700 } 701 702 first_frag = true; 703 } else { 704 int nr_frags = skb_shinfo(skb)->nr_frags; 705 struct page *page; 706 u8 *vaddr; 707 708 if (unlikely(nr_frags == (MAX_SKB_FRAGS - 1) && xp_mb_desc(desc))) { 709 err = -EOVERFLOW; 710 goto free_err; 711 } 712 713 page = alloc_page(xs->sk.sk_allocation); 714 if (unlikely(!page)) { 715 err = -EAGAIN; 716 goto free_err; 717 } 718 719 vaddr = kmap_local_page(page); 720 memcpy(vaddr, buffer, len); 721 kunmap_local(vaddr); 722 723 skb_add_rx_frag(skb, nr_frags, page, 0, len, PAGE_SIZE); 724 refcount_add(PAGE_SIZE, &xs->sk.sk_wmem_alloc); 725 } 726 727 if (first_frag && desc->options & XDP_TX_METADATA) { 728 if (unlikely(xs->pool->tx_metadata_len == 0)) { 729 err = -EINVAL; 730 goto free_err; 731 } 732 733 meta = buffer - xs->pool->tx_metadata_len; 734 if (unlikely(!xsk_buff_valid_tx_metadata(meta))) { 735 err = -EINVAL; 736 goto free_err; 737 } 738 739 if (meta->flags & XDP_TXMD_FLAGS_CHECKSUM) { 740 if (unlikely(meta->request.csum_start + 741 meta->request.csum_offset + 742 sizeof(__sum16) > len)) { 743 err = -EINVAL; 744 goto free_err; 745 } 746 747 skb->csum_start = hr + meta->request.csum_start; 748 skb->csum_offset = meta->request.csum_offset; 749 skb->ip_summed = CHECKSUM_PARTIAL; 750 751 if (unlikely(xs->pool->tx_sw_csum)) { 752 err = skb_checksum_help(skb); 753 if (err) 754 goto free_err; 755 } 756 } 757 } 758 } 759 760 skb->dev = dev; 761 skb->priority = READ_ONCE(xs->sk.sk_priority); 762 skb->mark = READ_ONCE(xs->sk.sk_mark); 763 skb->destructor = xsk_destruct_skb; 764 xsk_tx_metadata_to_compl(meta, &skb_shinfo(skb)->xsk_meta); 765 xsk_set_destructor_arg(skb); 766 767 return skb; 768 769 free_err: 770 if (err == -EOVERFLOW) { 771 /* Drop the packet */ 772 xsk_set_destructor_arg(xs->skb); 773 xsk_drop_skb(xs->skb); 774 xskq_cons_release(xs->tx); 775 } else { 776 /* Let application retry */ 777 xsk_cq_cancel_locked(xs, 1); 778 } 779 780 return ERR_PTR(err); 781 } 782 783 static int __xsk_generic_xmit(struct sock *sk) 784 { 785 struct xdp_sock *xs = xdp_sk(sk); 786 u32 max_batch = TX_BATCH_SIZE; 787 bool sent_frame = false; 788 struct xdp_desc desc; 789 struct sk_buff *skb; 790 int err = 0; 791 792 mutex_lock(&xs->mutex); 793 794 /* Since we dropped the RCU read lock, the socket state might have changed. */ 795 if (unlikely(!xsk_is_bound(xs))) { 796 err = -ENXIO; 797 goto out; 798 } 799 800 if (xs->queue_id >= xs->dev->real_num_tx_queues) 801 goto out; 802 803 while (xskq_cons_peek_desc(xs->tx, &desc, xs->pool)) { 804 if (max_batch-- == 0) { 805 err = -EAGAIN; 806 goto out; 807 } 808 809 /* This is the backpressure mechanism for the Tx path. 810 * Reserve space in the completion queue and only proceed 811 * if there is space in it. This avoids having to implement 812 * any buffering in the Tx path. 813 */ 814 if (xsk_cq_reserve_addr_locked(xs, desc.addr)) 815 goto out; 816 817 skb = xsk_build_skb(xs, &desc); 818 if (IS_ERR(skb)) { 819 err = PTR_ERR(skb); 820 if (err != -EOVERFLOW) 821 goto out; 822 err = 0; 823 continue; 824 } 825 826 xskq_cons_release(xs->tx); 827 828 if (xp_mb_desc(&desc)) { 829 xs->skb = skb; 830 continue; 831 } 832 833 err = __dev_direct_xmit(skb, xs->queue_id); 834 if (err == NETDEV_TX_BUSY) { 835 /* Tell user-space to retry the send */ 836 xskq_cons_cancel_n(xs->tx, xsk_get_num_desc(skb)); 837 xsk_consume_skb(skb); 838 err = -EAGAIN; 839 goto out; 840 } 841 842 /* Ignore NET_XMIT_CN as packet might have been sent */ 843 if (err == NET_XMIT_DROP) { 844 /* SKB completed but not sent */ 845 err = -EBUSY; 846 xs->skb = NULL; 847 goto out; 848 } 849 850 sent_frame = true; 851 xs->skb = NULL; 852 } 853 854 if (xskq_has_descs(xs->tx)) { 855 if (xs->skb) 856 xsk_drop_skb(xs->skb); 857 xskq_cons_release(xs->tx); 858 } 859 860 out: 861 if (sent_frame) 862 if (xsk_tx_writeable(xs)) 863 sk->sk_write_space(sk); 864 865 mutex_unlock(&xs->mutex); 866 return err; 867 } 868 869 static int xsk_generic_xmit(struct sock *sk) 870 { 871 int ret; 872 873 /* Drop the RCU lock since the SKB path might sleep. */ 874 rcu_read_unlock(); 875 ret = __xsk_generic_xmit(sk); 876 /* Reaquire RCU lock before going into common code. */ 877 rcu_read_lock(); 878 879 return ret; 880 } 881 882 static bool xsk_no_wakeup(struct sock *sk) 883 { 884 #ifdef CONFIG_NET_RX_BUSY_POLL 885 /* Prefer busy-polling, skip the wakeup. */ 886 return READ_ONCE(sk->sk_prefer_busy_poll) && READ_ONCE(sk->sk_ll_usec) && 887 READ_ONCE(sk->sk_napi_id) >= MIN_NAPI_ID; 888 #else 889 return false; 890 #endif 891 } 892 893 static int xsk_check_common(struct xdp_sock *xs) 894 { 895 if (unlikely(!xsk_is_bound(xs))) 896 return -ENXIO; 897 if (unlikely(!(xs->dev->flags & IFF_UP))) 898 return -ENETDOWN; 899 900 return 0; 901 } 902 903 static int __xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len) 904 { 905 bool need_wait = !(m->msg_flags & MSG_DONTWAIT); 906 struct sock *sk = sock->sk; 907 struct xdp_sock *xs = xdp_sk(sk); 908 struct xsk_buff_pool *pool; 909 int err; 910 911 err = xsk_check_common(xs); 912 if (err) 913 return err; 914 if (unlikely(need_wait)) 915 return -EOPNOTSUPP; 916 if (unlikely(!xs->tx)) 917 return -ENOBUFS; 918 919 if (sk_can_busy_loop(sk)) { 920 if (xs->zc) 921 __sk_mark_napi_id_once(sk, xsk_pool_get_napi_id(xs->pool)); 922 sk_busy_loop(sk, 1); /* only support non-blocking sockets */ 923 } 924 925 if (xs->zc && xsk_no_wakeup(sk)) 926 return 0; 927 928 pool = xs->pool; 929 if (pool->cached_need_wakeup & XDP_WAKEUP_TX) { 930 if (xs->zc) 931 return xsk_wakeup(xs, XDP_WAKEUP_TX); 932 return xsk_generic_xmit(sk); 933 } 934 return 0; 935 } 936 937 static int xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len) 938 { 939 int ret; 940 941 rcu_read_lock(); 942 ret = __xsk_sendmsg(sock, m, total_len); 943 rcu_read_unlock(); 944 945 return ret; 946 } 947 948 static int __xsk_recvmsg(struct socket *sock, struct msghdr *m, size_t len, int flags) 949 { 950 bool need_wait = !(flags & MSG_DONTWAIT); 951 struct sock *sk = sock->sk; 952 struct xdp_sock *xs = xdp_sk(sk); 953 int err; 954 955 err = xsk_check_common(xs); 956 if (err) 957 return err; 958 if (unlikely(!xs->rx)) 959 return -ENOBUFS; 960 if (unlikely(need_wait)) 961 return -EOPNOTSUPP; 962 963 if (sk_can_busy_loop(sk)) 964 sk_busy_loop(sk, 1); /* only support non-blocking sockets */ 965 966 if (xsk_no_wakeup(sk)) 967 return 0; 968 969 if (xs->pool->cached_need_wakeup & XDP_WAKEUP_RX && xs->zc) 970 return xsk_wakeup(xs, XDP_WAKEUP_RX); 971 return 0; 972 } 973 974 static int xsk_recvmsg(struct socket *sock, struct msghdr *m, size_t len, int flags) 975 { 976 int ret; 977 978 rcu_read_lock(); 979 ret = __xsk_recvmsg(sock, m, len, flags); 980 rcu_read_unlock(); 981 982 return ret; 983 } 984 985 static __poll_t xsk_poll(struct file *file, struct socket *sock, 986 struct poll_table_struct *wait) 987 { 988 __poll_t mask = 0; 989 struct sock *sk = sock->sk; 990 struct xdp_sock *xs = xdp_sk(sk); 991 struct xsk_buff_pool *pool; 992 993 sock_poll_wait(file, sock, wait); 994 995 rcu_read_lock(); 996 if (xsk_check_common(xs)) 997 goto out; 998 999 pool = xs->pool; 1000 1001 if (pool->cached_need_wakeup) { 1002 if (xs->zc) 1003 xsk_wakeup(xs, pool->cached_need_wakeup); 1004 else if (xs->tx) 1005 /* Poll needs to drive Tx also in copy mode */ 1006 xsk_generic_xmit(sk); 1007 } 1008 1009 if (xs->rx && !xskq_prod_is_empty(xs->rx)) 1010 mask |= EPOLLIN | EPOLLRDNORM; 1011 if (xs->tx && xsk_tx_writeable(xs)) 1012 mask |= EPOLLOUT | EPOLLWRNORM; 1013 out: 1014 rcu_read_unlock(); 1015 return mask; 1016 } 1017 1018 static int xsk_init_queue(u32 entries, struct xsk_queue **queue, 1019 bool umem_queue) 1020 { 1021 struct xsk_queue *q; 1022 1023 if (entries == 0 || *queue || !is_power_of_2(entries)) 1024 return -EINVAL; 1025 1026 q = xskq_create(entries, umem_queue); 1027 if (!q) 1028 return -ENOMEM; 1029 1030 /* Make sure queue is ready before it can be seen by others */ 1031 smp_wmb(); 1032 WRITE_ONCE(*queue, q); 1033 return 0; 1034 } 1035 1036 static void xsk_unbind_dev(struct xdp_sock *xs) 1037 { 1038 struct net_device *dev = xs->dev; 1039 1040 if (xs->state != XSK_BOUND) 1041 return; 1042 WRITE_ONCE(xs->state, XSK_UNBOUND); 1043 1044 /* Wait for driver to stop using the xdp socket. */ 1045 xp_del_xsk(xs->pool, xs); 1046 synchronize_net(); 1047 dev_put(dev); 1048 } 1049 1050 static struct xsk_map *xsk_get_map_list_entry(struct xdp_sock *xs, 1051 struct xdp_sock __rcu ***map_entry) 1052 { 1053 struct xsk_map *map = NULL; 1054 struct xsk_map_node *node; 1055 1056 *map_entry = NULL; 1057 1058 spin_lock_bh(&xs->map_list_lock); 1059 node = list_first_entry_or_null(&xs->map_list, struct xsk_map_node, 1060 node); 1061 if (node) { 1062 bpf_map_inc(&node->map->map); 1063 map = node->map; 1064 *map_entry = node->map_entry; 1065 } 1066 spin_unlock_bh(&xs->map_list_lock); 1067 return map; 1068 } 1069 1070 static void xsk_delete_from_maps(struct xdp_sock *xs) 1071 { 1072 /* This function removes the current XDP socket from all the 1073 * maps it resides in. We need to take extra care here, due to 1074 * the two locks involved. Each map has a lock synchronizing 1075 * updates to the entries, and each socket has a lock that 1076 * synchronizes access to the list of maps (map_list). For 1077 * deadlock avoidance the locks need to be taken in the order 1078 * "map lock"->"socket map list lock". We start off by 1079 * accessing the socket map list, and take a reference to the 1080 * map to guarantee existence between the 1081 * xsk_get_map_list_entry() and xsk_map_try_sock_delete() 1082 * calls. Then we ask the map to remove the socket, which 1083 * tries to remove the socket from the map. Note that there 1084 * might be updates to the map between 1085 * xsk_get_map_list_entry() and xsk_map_try_sock_delete(). 1086 */ 1087 struct xdp_sock __rcu **map_entry = NULL; 1088 struct xsk_map *map; 1089 1090 while ((map = xsk_get_map_list_entry(xs, &map_entry))) { 1091 xsk_map_try_sock_delete(map, xs, map_entry); 1092 bpf_map_put(&map->map); 1093 } 1094 } 1095 1096 static int xsk_release(struct socket *sock) 1097 { 1098 struct sock *sk = sock->sk; 1099 struct xdp_sock *xs = xdp_sk(sk); 1100 struct net *net; 1101 1102 if (!sk) 1103 return 0; 1104 1105 net = sock_net(sk); 1106 1107 if (xs->skb) 1108 xsk_drop_skb(xs->skb); 1109 1110 mutex_lock(&net->xdp.lock); 1111 sk_del_node_init_rcu(sk); 1112 mutex_unlock(&net->xdp.lock); 1113 1114 sock_prot_inuse_add(net, sk->sk_prot, -1); 1115 1116 xsk_delete_from_maps(xs); 1117 mutex_lock(&xs->mutex); 1118 xsk_unbind_dev(xs); 1119 mutex_unlock(&xs->mutex); 1120 1121 xskq_destroy(xs->rx); 1122 xskq_destroy(xs->tx); 1123 xskq_destroy(xs->fq_tmp); 1124 xskq_destroy(xs->cq_tmp); 1125 1126 sock_orphan(sk); 1127 sock->sk = NULL; 1128 1129 sock_put(sk); 1130 1131 return 0; 1132 } 1133 1134 static struct socket *xsk_lookup_xsk_from_fd(int fd) 1135 { 1136 struct socket *sock; 1137 int err; 1138 1139 sock = sockfd_lookup(fd, &err); 1140 if (!sock) 1141 return ERR_PTR(-ENOTSOCK); 1142 1143 if (sock->sk->sk_family != PF_XDP) { 1144 sockfd_put(sock); 1145 return ERR_PTR(-ENOPROTOOPT); 1146 } 1147 1148 return sock; 1149 } 1150 1151 static bool xsk_validate_queues(struct xdp_sock *xs) 1152 { 1153 return xs->fq_tmp && xs->cq_tmp; 1154 } 1155 1156 static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len) 1157 { 1158 struct sockaddr_xdp *sxdp = (struct sockaddr_xdp *)addr; 1159 struct sock *sk = sock->sk; 1160 struct xdp_sock *xs = xdp_sk(sk); 1161 struct net_device *dev; 1162 int bound_dev_if; 1163 u32 flags, qid; 1164 int err = 0; 1165 1166 if (addr_len < sizeof(struct sockaddr_xdp)) 1167 return -EINVAL; 1168 if (sxdp->sxdp_family != AF_XDP) 1169 return -EINVAL; 1170 1171 flags = sxdp->sxdp_flags; 1172 if (flags & ~(XDP_SHARED_UMEM | XDP_COPY | XDP_ZEROCOPY | 1173 XDP_USE_NEED_WAKEUP | XDP_USE_SG)) 1174 return -EINVAL; 1175 1176 bound_dev_if = READ_ONCE(sk->sk_bound_dev_if); 1177 if (bound_dev_if && bound_dev_if != sxdp->sxdp_ifindex) 1178 return -EINVAL; 1179 1180 rtnl_lock(); 1181 mutex_lock(&xs->mutex); 1182 if (xs->state != XSK_READY) { 1183 err = -EBUSY; 1184 goto out_release; 1185 } 1186 1187 dev = dev_get_by_index(sock_net(sk), sxdp->sxdp_ifindex); 1188 if (!dev) { 1189 err = -ENODEV; 1190 goto out_release; 1191 } 1192 1193 if (!xs->rx && !xs->tx) { 1194 err = -EINVAL; 1195 goto out_unlock; 1196 } 1197 1198 qid = sxdp->sxdp_queue_id; 1199 1200 if (flags & XDP_SHARED_UMEM) { 1201 struct xdp_sock *umem_xs; 1202 struct socket *sock; 1203 1204 if ((flags & XDP_COPY) || (flags & XDP_ZEROCOPY) || 1205 (flags & XDP_USE_NEED_WAKEUP) || (flags & XDP_USE_SG)) { 1206 /* Cannot specify flags for shared sockets. */ 1207 err = -EINVAL; 1208 goto out_unlock; 1209 } 1210 1211 if (xs->umem) { 1212 /* We have already our own. */ 1213 err = -EINVAL; 1214 goto out_unlock; 1215 } 1216 1217 sock = xsk_lookup_xsk_from_fd(sxdp->sxdp_shared_umem_fd); 1218 if (IS_ERR(sock)) { 1219 err = PTR_ERR(sock); 1220 goto out_unlock; 1221 } 1222 1223 umem_xs = xdp_sk(sock->sk); 1224 if (!xsk_is_bound(umem_xs)) { 1225 err = -EBADF; 1226 sockfd_put(sock); 1227 goto out_unlock; 1228 } 1229 1230 if (umem_xs->queue_id != qid || umem_xs->dev != dev) { 1231 /* Share the umem with another socket on another qid 1232 * and/or device. 1233 */ 1234 xs->pool = xp_create_and_assign_umem(xs, 1235 umem_xs->umem); 1236 if (!xs->pool) { 1237 err = -ENOMEM; 1238 sockfd_put(sock); 1239 goto out_unlock; 1240 } 1241 1242 err = xp_assign_dev_shared(xs->pool, umem_xs, dev, 1243 qid); 1244 if (err) { 1245 xp_destroy(xs->pool); 1246 xs->pool = NULL; 1247 sockfd_put(sock); 1248 goto out_unlock; 1249 } 1250 } else { 1251 /* Share the buffer pool with the other socket. */ 1252 if (xs->fq_tmp || xs->cq_tmp) { 1253 /* Do not allow setting your own fq or cq. */ 1254 err = -EINVAL; 1255 sockfd_put(sock); 1256 goto out_unlock; 1257 } 1258 1259 xp_get_pool(umem_xs->pool); 1260 xs->pool = umem_xs->pool; 1261 1262 /* If underlying shared umem was created without Tx 1263 * ring, allocate Tx descs array that Tx batching API 1264 * utilizes 1265 */ 1266 if (xs->tx && !xs->pool->tx_descs) { 1267 err = xp_alloc_tx_descs(xs->pool, xs); 1268 if (err) { 1269 xp_put_pool(xs->pool); 1270 xs->pool = NULL; 1271 sockfd_put(sock); 1272 goto out_unlock; 1273 } 1274 } 1275 } 1276 1277 xdp_get_umem(umem_xs->umem); 1278 WRITE_ONCE(xs->umem, umem_xs->umem); 1279 sockfd_put(sock); 1280 } else if (!xs->umem || !xsk_validate_queues(xs)) { 1281 err = -EINVAL; 1282 goto out_unlock; 1283 } else { 1284 /* This xsk has its own umem. */ 1285 xs->pool = xp_create_and_assign_umem(xs, xs->umem); 1286 if (!xs->pool) { 1287 err = -ENOMEM; 1288 goto out_unlock; 1289 } 1290 1291 err = xp_assign_dev(xs->pool, dev, qid, flags); 1292 if (err) { 1293 xp_destroy(xs->pool); 1294 xs->pool = NULL; 1295 goto out_unlock; 1296 } 1297 } 1298 1299 /* FQ and CQ are now owned by the buffer pool and cleaned up with it. */ 1300 xs->fq_tmp = NULL; 1301 xs->cq_tmp = NULL; 1302 1303 xs->dev = dev; 1304 xs->zc = xs->umem->zc; 1305 xs->sg = !!(xs->umem->flags & XDP_UMEM_SG_FLAG); 1306 xs->queue_id = qid; 1307 xp_add_xsk(xs->pool, xs); 1308 1309 out_unlock: 1310 if (err) { 1311 dev_put(dev); 1312 } else { 1313 /* Matches smp_rmb() in bind() for shared umem 1314 * sockets, and xsk_is_bound(). 1315 */ 1316 smp_wmb(); 1317 WRITE_ONCE(xs->state, XSK_BOUND); 1318 } 1319 out_release: 1320 mutex_unlock(&xs->mutex); 1321 rtnl_unlock(); 1322 return err; 1323 } 1324 1325 struct xdp_umem_reg_v1 { 1326 __u64 addr; /* Start of packet data area */ 1327 __u64 len; /* Length of packet data area */ 1328 __u32 chunk_size; 1329 __u32 headroom; 1330 }; 1331 1332 struct xdp_umem_reg_v2 { 1333 __u64 addr; /* Start of packet data area */ 1334 __u64 len; /* Length of packet data area */ 1335 __u32 chunk_size; 1336 __u32 headroom; 1337 __u32 flags; 1338 }; 1339 1340 static int xsk_setsockopt(struct socket *sock, int level, int optname, 1341 sockptr_t optval, unsigned int optlen) 1342 { 1343 struct sock *sk = sock->sk; 1344 struct xdp_sock *xs = xdp_sk(sk); 1345 int err; 1346 1347 if (level != SOL_XDP) 1348 return -ENOPROTOOPT; 1349 1350 switch (optname) { 1351 case XDP_RX_RING: 1352 case XDP_TX_RING: 1353 { 1354 struct xsk_queue **q; 1355 int entries; 1356 1357 if (optlen < sizeof(entries)) 1358 return -EINVAL; 1359 if (copy_from_sockptr(&entries, optval, sizeof(entries))) 1360 return -EFAULT; 1361 1362 mutex_lock(&xs->mutex); 1363 if (xs->state != XSK_READY) { 1364 mutex_unlock(&xs->mutex); 1365 return -EBUSY; 1366 } 1367 q = (optname == XDP_TX_RING) ? &xs->tx : &xs->rx; 1368 err = xsk_init_queue(entries, q, false); 1369 if (!err && optname == XDP_TX_RING) 1370 /* Tx needs to be explicitly woken up the first time */ 1371 xs->tx->ring->flags |= XDP_RING_NEED_WAKEUP; 1372 mutex_unlock(&xs->mutex); 1373 return err; 1374 } 1375 case XDP_UMEM_REG: 1376 { 1377 size_t mr_size = sizeof(struct xdp_umem_reg); 1378 struct xdp_umem_reg mr = {}; 1379 struct xdp_umem *umem; 1380 1381 if (optlen < sizeof(struct xdp_umem_reg_v1)) 1382 return -EINVAL; 1383 else if (optlen < sizeof(struct xdp_umem_reg_v2)) 1384 mr_size = sizeof(struct xdp_umem_reg_v1); 1385 else if (optlen < sizeof(mr)) 1386 mr_size = sizeof(struct xdp_umem_reg_v2); 1387 1388 if (copy_from_sockptr(&mr, optval, mr_size)) 1389 return -EFAULT; 1390 1391 mutex_lock(&xs->mutex); 1392 if (xs->state != XSK_READY || xs->umem) { 1393 mutex_unlock(&xs->mutex); 1394 return -EBUSY; 1395 } 1396 1397 umem = xdp_umem_create(&mr); 1398 if (IS_ERR(umem)) { 1399 mutex_unlock(&xs->mutex); 1400 return PTR_ERR(umem); 1401 } 1402 1403 /* Make sure umem is ready before it can be seen by others */ 1404 smp_wmb(); 1405 WRITE_ONCE(xs->umem, umem); 1406 mutex_unlock(&xs->mutex); 1407 return 0; 1408 } 1409 case XDP_UMEM_FILL_RING: 1410 case XDP_UMEM_COMPLETION_RING: 1411 { 1412 struct xsk_queue **q; 1413 int entries; 1414 1415 if (optlen < sizeof(entries)) 1416 return -EINVAL; 1417 if (copy_from_sockptr(&entries, optval, sizeof(entries))) 1418 return -EFAULT; 1419 1420 mutex_lock(&xs->mutex); 1421 if (xs->state != XSK_READY) { 1422 mutex_unlock(&xs->mutex); 1423 return -EBUSY; 1424 } 1425 1426 q = (optname == XDP_UMEM_FILL_RING) ? &xs->fq_tmp : 1427 &xs->cq_tmp; 1428 err = xsk_init_queue(entries, q, true); 1429 mutex_unlock(&xs->mutex); 1430 return err; 1431 } 1432 default: 1433 break; 1434 } 1435 1436 return -ENOPROTOOPT; 1437 } 1438 1439 static void xsk_enter_rxtx_offsets(struct xdp_ring_offset_v1 *ring) 1440 { 1441 ring->producer = offsetof(struct xdp_rxtx_ring, ptrs.producer); 1442 ring->consumer = offsetof(struct xdp_rxtx_ring, ptrs.consumer); 1443 ring->desc = offsetof(struct xdp_rxtx_ring, desc); 1444 } 1445 1446 static void xsk_enter_umem_offsets(struct xdp_ring_offset_v1 *ring) 1447 { 1448 ring->producer = offsetof(struct xdp_umem_ring, ptrs.producer); 1449 ring->consumer = offsetof(struct xdp_umem_ring, ptrs.consumer); 1450 ring->desc = offsetof(struct xdp_umem_ring, desc); 1451 } 1452 1453 struct xdp_statistics_v1 { 1454 __u64 rx_dropped; 1455 __u64 rx_invalid_descs; 1456 __u64 tx_invalid_descs; 1457 }; 1458 1459 static int xsk_getsockopt(struct socket *sock, int level, int optname, 1460 char __user *optval, int __user *optlen) 1461 { 1462 struct sock *sk = sock->sk; 1463 struct xdp_sock *xs = xdp_sk(sk); 1464 int len; 1465 1466 if (level != SOL_XDP) 1467 return -ENOPROTOOPT; 1468 1469 if (get_user(len, optlen)) 1470 return -EFAULT; 1471 if (len < 0) 1472 return -EINVAL; 1473 1474 switch (optname) { 1475 case XDP_STATISTICS: 1476 { 1477 struct xdp_statistics stats = {}; 1478 bool extra_stats = true; 1479 size_t stats_size; 1480 1481 if (len < sizeof(struct xdp_statistics_v1)) { 1482 return -EINVAL; 1483 } else if (len < sizeof(stats)) { 1484 extra_stats = false; 1485 stats_size = sizeof(struct xdp_statistics_v1); 1486 } else { 1487 stats_size = sizeof(stats); 1488 } 1489 1490 mutex_lock(&xs->mutex); 1491 stats.rx_dropped = xs->rx_dropped; 1492 if (extra_stats) { 1493 stats.rx_ring_full = xs->rx_queue_full; 1494 stats.rx_fill_ring_empty_descs = 1495 xs->pool ? xskq_nb_queue_empty_descs(xs->pool->fq) : 0; 1496 stats.tx_ring_empty_descs = xskq_nb_queue_empty_descs(xs->tx); 1497 } else { 1498 stats.rx_dropped += xs->rx_queue_full; 1499 } 1500 stats.rx_invalid_descs = xskq_nb_invalid_descs(xs->rx); 1501 stats.tx_invalid_descs = xskq_nb_invalid_descs(xs->tx); 1502 mutex_unlock(&xs->mutex); 1503 1504 if (copy_to_user(optval, &stats, stats_size)) 1505 return -EFAULT; 1506 if (put_user(stats_size, optlen)) 1507 return -EFAULT; 1508 1509 return 0; 1510 } 1511 case XDP_MMAP_OFFSETS: 1512 { 1513 struct xdp_mmap_offsets off; 1514 struct xdp_mmap_offsets_v1 off_v1; 1515 bool flags_supported = true; 1516 void *to_copy; 1517 1518 if (len < sizeof(off_v1)) 1519 return -EINVAL; 1520 else if (len < sizeof(off)) 1521 flags_supported = false; 1522 1523 if (flags_supported) { 1524 /* xdp_ring_offset is identical to xdp_ring_offset_v1 1525 * except for the flags field added to the end. 1526 */ 1527 xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *) 1528 &off.rx); 1529 xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *) 1530 &off.tx); 1531 xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *) 1532 &off.fr); 1533 xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *) 1534 &off.cr); 1535 off.rx.flags = offsetof(struct xdp_rxtx_ring, 1536 ptrs.flags); 1537 off.tx.flags = offsetof(struct xdp_rxtx_ring, 1538 ptrs.flags); 1539 off.fr.flags = offsetof(struct xdp_umem_ring, 1540 ptrs.flags); 1541 off.cr.flags = offsetof(struct xdp_umem_ring, 1542 ptrs.flags); 1543 1544 len = sizeof(off); 1545 to_copy = &off; 1546 } else { 1547 xsk_enter_rxtx_offsets(&off_v1.rx); 1548 xsk_enter_rxtx_offsets(&off_v1.tx); 1549 xsk_enter_umem_offsets(&off_v1.fr); 1550 xsk_enter_umem_offsets(&off_v1.cr); 1551 1552 len = sizeof(off_v1); 1553 to_copy = &off_v1; 1554 } 1555 1556 if (copy_to_user(optval, to_copy, len)) 1557 return -EFAULT; 1558 if (put_user(len, optlen)) 1559 return -EFAULT; 1560 1561 return 0; 1562 } 1563 case XDP_OPTIONS: 1564 { 1565 struct xdp_options opts = {}; 1566 1567 if (len < sizeof(opts)) 1568 return -EINVAL; 1569 1570 mutex_lock(&xs->mutex); 1571 if (xs->zc) 1572 opts.flags |= XDP_OPTIONS_ZEROCOPY; 1573 mutex_unlock(&xs->mutex); 1574 1575 len = sizeof(opts); 1576 if (copy_to_user(optval, &opts, len)) 1577 return -EFAULT; 1578 if (put_user(len, optlen)) 1579 return -EFAULT; 1580 1581 return 0; 1582 } 1583 default: 1584 break; 1585 } 1586 1587 return -EOPNOTSUPP; 1588 } 1589 1590 static int xsk_mmap(struct file *file, struct socket *sock, 1591 struct vm_area_struct *vma) 1592 { 1593 loff_t offset = (loff_t)vma->vm_pgoff << PAGE_SHIFT; 1594 unsigned long size = vma->vm_end - vma->vm_start; 1595 struct xdp_sock *xs = xdp_sk(sock->sk); 1596 int state = READ_ONCE(xs->state); 1597 struct xsk_queue *q = NULL; 1598 1599 if (state != XSK_READY && state != XSK_BOUND) 1600 return -EBUSY; 1601 1602 if (offset == XDP_PGOFF_RX_RING) { 1603 q = READ_ONCE(xs->rx); 1604 } else if (offset == XDP_PGOFF_TX_RING) { 1605 q = READ_ONCE(xs->tx); 1606 } else { 1607 /* Matches the smp_wmb() in XDP_UMEM_REG */ 1608 smp_rmb(); 1609 if (offset == XDP_UMEM_PGOFF_FILL_RING) 1610 q = state == XSK_READY ? READ_ONCE(xs->fq_tmp) : 1611 READ_ONCE(xs->pool->fq); 1612 else if (offset == XDP_UMEM_PGOFF_COMPLETION_RING) 1613 q = state == XSK_READY ? READ_ONCE(xs->cq_tmp) : 1614 READ_ONCE(xs->pool->cq); 1615 } 1616 1617 if (!q) 1618 return -EINVAL; 1619 1620 /* Matches the smp_wmb() in xsk_init_queue */ 1621 smp_rmb(); 1622 if (size > q->ring_vmalloc_size) 1623 return -EINVAL; 1624 1625 return remap_vmalloc_range(vma, q->ring, 0); 1626 } 1627 1628 static int xsk_notifier(struct notifier_block *this, 1629 unsigned long msg, void *ptr) 1630 { 1631 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1632 struct net *net = dev_net(dev); 1633 struct sock *sk; 1634 1635 switch (msg) { 1636 case NETDEV_UNREGISTER: 1637 mutex_lock(&net->xdp.lock); 1638 sk_for_each(sk, &net->xdp.list) { 1639 struct xdp_sock *xs = xdp_sk(sk); 1640 1641 mutex_lock(&xs->mutex); 1642 if (xs->dev == dev) { 1643 sk->sk_err = ENETDOWN; 1644 if (!sock_flag(sk, SOCK_DEAD)) 1645 sk_error_report(sk); 1646 1647 xsk_unbind_dev(xs); 1648 1649 /* Clear device references. */ 1650 xp_clear_dev(xs->pool); 1651 } 1652 mutex_unlock(&xs->mutex); 1653 } 1654 mutex_unlock(&net->xdp.lock); 1655 break; 1656 } 1657 return NOTIFY_DONE; 1658 } 1659 1660 static struct proto xsk_proto = { 1661 .name = "XDP", 1662 .owner = THIS_MODULE, 1663 .obj_size = sizeof(struct xdp_sock), 1664 }; 1665 1666 static const struct proto_ops xsk_proto_ops = { 1667 .family = PF_XDP, 1668 .owner = THIS_MODULE, 1669 .release = xsk_release, 1670 .bind = xsk_bind, 1671 .connect = sock_no_connect, 1672 .socketpair = sock_no_socketpair, 1673 .accept = sock_no_accept, 1674 .getname = sock_no_getname, 1675 .poll = xsk_poll, 1676 .ioctl = sock_no_ioctl, 1677 .listen = sock_no_listen, 1678 .shutdown = sock_no_shutdown, 1679 .setsockopt = xsk_setsockopt, 1680 .getsockopt = xsk_getsockopt, 1681 .sendmsg = xsk_sendmsg, 1682 .recvmsg = xsk_recvmsg, 1683 .mmap = xsk_mmap, 1684 }; 1685 1686 static void xsk_destruct(struct sock *sk) 1687 { 1688 struct xdp_sock *xs = xdp_sk(sk); 1689 1690 if (!sock_flag(sk, SOCK_DEAD)) 1691 return; 1692 1693 if (!xp_put_pool(xs->pool)) 1694 xdp_put_umem(xs->umem, !xs->pool); 1695 } 1696 1697 static int xsk_create(struct net *net, struct socket *sock, int protocol, 1698 int kern) 1699 { 1700 struct xdp_sock *xs; 1701 struct sock *sk; 1702 1703 if (!ns_capable(net->user_ns, CAP_NET_RAW)) 1704 return -EPERM; 1705 if (sock->type != SOCK_RAW) 1706 return -ESOCKTNOSUPPORT; 1707 1708 if (protocol) 1709 return -EPROTONOSUPPORT; 1710 1711 sock->state = SS_UNCONNECTED; 1712 1713 sk = sk_alloc(net, PF_XDP, GFP_KERNEL, &xsk_proto, kern); 1714 if (!sk) 1715 return -ENOBUFS; 1716 1717 sock->ops = &xsk_proto_ops; 1718 1719 sock_init_data(sock, sk); 1720 1721 sk->sk_family = PF_XDP; 1722 1723 sk->sk_destruct = xsk_destruct; 1724 1725 sock_set_flag(sk, SOCK_RCU_FREE); 1726 1727 xs = xdp_sk(sk); 1728 xs->state = XSK_READY; 1729 mutex_init(&xs->mutex); 1730 spin_lock_init(&xs->rx_lock); 1731 1732 INIT_LIST_HEAD(&xs->map_list); 1733 spin_lock_init(&xs->map_list_lock); 1734 1735 mutex_lock(&net->xdp.lock); 1736 sk_add_node_rcu(sk, &net->xdp.list); 1737 mutex_unlock(&net->xdp.lock); 1738 1739 sock_prot_inuse_add(net, &xsk_proto, 1); 1740 1741 return 0; 1742 } 1743 1744 static const struct net_proto_family xsk_family_ops = { 1745 .family = PF_XDP, 1746 .create = xsk_create, 1747 .owner = THIS_MODULE, 1748 }; 1749 1750 static struct notifier_block xsk_netdev_notifier = { 1751 .notifier_call = xsk_notifier, 1752 }; 1753 1754 static int __net_init xsk_net_init(struct net *net) 1755 { 1756 mutex_init(&net->xdp.lock); 1757 INIT_HLIST_HEAD(&net->xdp.list); 1758 return 0; 1759 } 1760 1761 static void __net_exit xsk_net_exit(struct net *net) 1762 { 1763 WARN_ON_ONCE(!hlist_empty(&net->xdp.list)); 1764 } 1765 1766 static struct pernet_operations xsk_net_ops = { 1767 .init = xsk_net_init, 1768 .exit = xsk_net_exit, 1769 }; 1770 1771 static int __init xsk_init(void) 1772 { 1773 int err; 1774 1775 err = proto_register(&xsk_proto, 0 /* no slab */); 1776 if (err) 1777 goto out; 1778 1779 err = sock_register(&xsk_family_ops); 1780 if (err) 1781 goto out_proto; 1782 1783 err = register_pernet_subsys(&xsk_net_ops); 1784 if (err) 1785 goto out_sk; 1786 1787 err = register_netdevice_notifier(&xsk_netdev_notifier); 1788 if (err) 1789 goto out_pernet; 1790 1791 return 0; 1792 1793 out_pernet: 1794 unregister_pernet_subsys(&xsk_net_ops); 1795 out_sk: 1796 sock_unregister(PF_XDP); 1797 out_proto: 1798 proto_unregister(&xsk_proto); 1799 out: 1800 return err; 1801 } 1802 1803 fs_initcall(xsk_init); 1804