1 // SPDX-License-Identifier: GPL-2.0-only 2 /* net/core/xdp.c 3 * 4 * Copyright (c) 2017 Jesper Dangaard Brouer, Red Hat Inc. 5 */ 6 #include <linux/bpf.h> 7 #include <linux/filter.h> 8 #include <linux/types.h> 9 #include <linux/mm.h> 10 #include <linux/netdevice.h> 11 #include <linux/slab.h> 12 #include <linux/idr.h> 13 #include <linux/rhashtable.h> 14 #include <linux/bug.h> 15 #include <net/page_pool.h> 16 17 #include <net/xdp.h> 18 #include <net/xdp_priv.h> /* struct xdp_mem_allocator */ 19 #include <trace/events/xdp.h> 20 #include <net/xdp_sock_drv.h> 21 22 #define REG_STATE_NEW 0x0 23 #define REG_STATE_REGISTERED 0x1 24 #define REG_STATE_UNREGISTERED 0x2 25 #define REG_STATE_UNUSED 0x3 26 27 static DEFINE_IDA(mem_id_pool); 28 static DEFINE_MUTEX(mem_id_lock); 29 #define MEM_ID_MAX 0xFFFE 30 #define MEM_ID_MIN 1 31 static int mem_id_next = MEM_ID_MIN; 32 33 static bool mem_id_init; /* false */ 34 static struct rhashtable *mem_id_ht; 35 36 static u32 xdp_mem_id_hashfn(const void *data, u32 len, u32 seed) 37 { 38 const u32 *k = data; 39 const u32 key = *k; 40 41 BUILD_BUG_ON(sizeof_field(struct xdp_mem_allocator, mem.id) 42 != sizeof(u32)); 43 44 /* Use cyclic increasing ID as direct hash key */ 45 return key; 46 } 47 48 static int xdp_mem_id_cmp(struct rhashtable_compare_arg *arg, 49 const void *ptr) 50 { 51 const struct xdp_mem_allocator *xa = ptr; 52 u32 mem_id = *(u32 *)arg->key; 53 54 return xa->mem.id != mem_id; 55 } 56 57 static const struct rhashtable_params mem_id_rht_params = { 58 .nelem_hint = 64, 59 .head_offset = offsetof(struct xdp_mem_allocator, node), 60 .key_offset = offsetof(struct xdp_mem_allocator, mem.id), 61 .key_len = sizeof_field(struct xdp_mem_allocator, mem.id), 62 .max_size = MEM_ID_MAX, 63 .min_size = 8, 64 .automatic_shrinking = true, 65 .hashfn = xdp_mem_id_hashfn, 66 .obj_cmpfn = xdp_mem_id_cmp, 67 }; 68 69 static void __xdp_mem_allocator_rcu_free(struct rcu_head *rcu) 70 { 71 struct xdp_mem_allocator *xa; 72 73 xa = container_of(rcu, struct xdp_mem_allocator, rcu); 74 75 /* Allow this ID to be reused */ 76 ida_simple_remove(&mem_id_pool, xa->mem.id); 77 78 kfree(xa); 79 } 80 81 static void mem_xa_remove(struct xdp_mem_allocator *xa) 82 { 83 trace_mem_disconnect(xa); 84 85 if (!rhashtable_remove_fast(mem_id_ht, &xa->node, mem_id_rht_params)) 86 call_rcu(&xa->rcu, __xdp_mem_allocator_rcu_free); 87 } 88 89 static void mem_allocator_disconnect(void *allocator) 90 { 91 struct xdp_mem_allocator *xa; 92 struct rhashtable_iter iter; 93 94 mutex_lock(&mem_id_lock); 95 96 rhashtable_walk_enter(mem_id_ht, &iter); 97 do { 98 rhashtable_walk_start(&iter); 99 100 while ((xa = rhashtable_walk_next(&iter)) && !IS_ERR(xa)) { 101 if (xa->allocator == allocator) 102 mem_xa_remove(xa); 103 } 104 105 rhashtable_walk_stop(&iter); 106 107 } while (xa == ERR_PTR(-EAGAIN)); 108 rhashtable_walk_exit(&iter); 109 110 mutex_unlock(&mem_id_lock); 111 } 112 113 void xdp_unreg_mem_model(struct xdp_mem_info *mem) 114 { 115 struct xdp_mem_allocator *xa; 116 int type = mem->type; 117 int id = mem->id; 118 119 /* Reset mem info to defaults */ 120 mem->id = 0; 121 mem->type = 0; 122 123 if (id == 0) 124 return; 125 126 if (type == MEM_TYPE_PAGE_POOL) { 127 rcu_read_lock(); 128 xa = rhashtable_lookup(mem_id_ht, &id, mem_id_rht_params); 129 page_pool_destroy(xa->page_pool); 130 rcu_read_unlock(); 131 } 132 } 133 EXPORT_SYMBOL_GPL(xdp_unreg_mem_model); 134 135 void xdp_rxq_info_unreg_mem_model(struct xdp_rxq_info *xdp_rxq) 136 { 137 if (xdp_rxq->reg_state != REG_STATE_REGISTERED) { 138 WARN(1, "Missing register, driver bug"); 139 return; 140 } 141 142 xdp_unreg_mem_model(&xdp_rxq->mem); 143 } 144 EXPORT_SYMBOL_GPL(xdp_rxq_info_unreg_mem_model); 145 146 void xdp_rxq_info_unreg(struct xdp_rxq_info *xdp_rxq) 147 { 148 /* Simplify driver cleanup code paths, allow unreg "unused" */ 149 if (xdp_rxq->reg_state == REG_STATE_UNUSED) 150 return; 151 152 xdp_rxq_info_unreg_mem_model(xdp_rxq); 153 154 xdp_rxq->reg_state = REG_STATE_UNREGISTERED; 155 xdp_rxq->dev = NULL; 156 } 157 EXPORT_SYMBOL_GPL(xdp_rxq_info_unreg); 158 159 static void xdp_rxq_info_init(struct xdp_rxq_info *xdp_rxq) 160 { 161 memset(xdp_rxq, 0, sizeof(*xdp_rxq)); 162 } 163 164 /* Returns 0 on success, negative on failure */ 165 int __xdp_rxq_info_reg(struct xdp_rxq_info *xdp_rxq, 166 struct net_device *dev, u32 queue_index, 167 unsigned int napi_id, u32 frag_size) 168 { 169 if (!dev) { 170 WARN(1, "Missing net_device from driver"); 171 return -ENODEV; 172 } 173 174 if (xdp_rxq->reg_state == REG_STATE_UNUSED) { 175 WARN(1, "Driver promised not to register this"); 176 return -EINVAL; 177 } 178 179 if (xdp_rxq->reg_state == REG_STATE_REGISTERED) { 180 WARN(1, "Missing unregister, handled but fix driver"); 181 xdp_rxq_info_unreg(xdp_rxq); 182 } 183 184 /* State either UNREGISTERED or NEW */ 185 xdp_rxq_info_init(xdp_rxq); 186 xdp_rxq->dev = dev; 187 xdp_rxq->queue_index = queue_index; 188 xdp_rxq->napi_id = napi_id; 189 xdp_rxq->frag_size = frag_size; 190 191 xdp_rxq->reg_state = REG_STATE_REGISTERED; 192 return 0; 193 } 194 EXPORT_SYMBOL_GPL(__xdp_rxq_info_reg); 195 196 void xdp_rxq_info_unused(struct xdp_rxq_info *xdp_rxq) 197 { 198 xdp_rxq->reg_state = REG_STATE_UNUSED; 199 } 200 EXPORT_SYMBOL_GPL(xdp_rxq_info_unused); 201 202 bool xdp_rxq_info_is_reg(struct xdp_rxq_info *xdp_rxq) 203 { 204 return (xdp_rxq->reg_state == REG_STATE_REGISTERED); 205 } 206 EXPORT_SYMBOL_GPL(xdp_rxq_info_is_reg); 207 208 static int __mem_id_init_hash_table(void) 209 { 210 struct rhashtable *rht; 211 int ret; 212 213 if (unlikely(mem_id_init)) 214 return 0; 215 216 rht = kzalloc(sizeof(*rht), GFP_KERNEL); 217 if (!rht) 218 return -ENOMEM; 219 220 ret = rhashtable_init(rht, &mem_id_rht_params); 221 if (ret < 0) { 222 kfree(rht); 223 return ret; 224 } 225 mem_id_ht = rht; 226 smp_mb(); /* mutex lock should provide enough pairing */ 227 mem_id_init = true; 228 229 return 0; 230 } 231 232 /* Allocate a cyclic ID that maps to allocator pointer. 233 * See: https://www.kernel.org/doc/html/latest/core-api/idr.html 234 * 235 * Caller must lock mem_id_lock. 236 */ 237 static int __mem_id_cyclic_get(gfp_t gfp) 238 { 239 int retries = 1; 240 int id; 241 242 again: 243 id = ida_simple_get(&mem_id_pool, mem_id_next, MEM_ID_MAX, gfp); 244 if (id < 0) { 245 if (id == -ENOSPC) { 246 /* Cyclic allocator, reset next id */ 247 if (retries--) { 248 mem_id_next = MEM_ID_MIN; 249 goto again; 250 } 251 } 252 return id; /* errno */ 253 } 254 mem_id_next = id + 1; 255 256 return id; 257 } 258 259 static bool __is_supported_mem_type(enum xdp_mem_type type) 260 { 261 if (type == MEM_TYPE_PAGE_POOL) 262 return is_page_pool_compiled_in(); 263 264 if (type >= MEM_TYPE_MAX) 265 return false; 266 267 return true; 268 } 269 270 static struct xdp_mem_allocator *__xdp_reg_mem_model(struct xdp_mem_info *mem, 271 enum xdp_mem_type type, 272 void *allocator) 273 { 274 struct xdp_mem_allocator *xdp_alloc; 275 gfp_t gfp = GFP_KERNEL; 276 int id, errno, ret; 277 void *ptr; 278 279 if (!__is_supported_mem_type(type)) 280 return ERR_PTR(-EOPNOTSUPP); 281 282 mem->type = type; 283 284 if (!allocator) { 285 if (type == MEM_TYPE_PAGE_POOL) 286 return ERR_PTR(-EINVAL); /* Setup time check page_pool req */ 287 return NULL; 288 } 289 290 /* Delay init of rhashtable to save memory if feature isn't used */ 291 if (!mem_id_init) { 292 mutex_lock(&mem_id_lock); 293 ret = __mem_id_init_hash_table(); 294 mutex_unlock(&mem_id_lock); 295 if (ret < 0) { 296 WARN_ON(1); 297 return ERR_PTR(ret); 298 } 299 } 300 301 xdp_alloc = kzalloc(sizeof(*xdp_alloc), gfp); 302 if (!xdp_alloc) 303 return ERR_PTR(-ENOMEM); 304 305 mutex_lock(&mem_id_lock); 306 id = __mem_id_cyclic_get(gfp); 307 if (id < 0) { 308 errno = id; 309 goto err; 310 } 311 mem->id = id; 312 xdp_alloc->mem = *mem; 313 xdp_alloc->allocator = allocator; 314 315 /* Insert allocator into ID lookup table */ 316 ptr = rhashtable_insert_slow(mem_id_ht, &id, &xdp_alloc->node); 317 if (IS_ERR(ptr)) { 318 ida_simple_remove(&mem_id_pool, mem->id); 319 mem->id = 0; 320 errno = PTR_ERR(ptr); 321 goto err; 322 } 323 324 if (type == MEM_TYPE_PAGE_POOL) 325 page_pool_use_xdp_mem(allocator, mem_allocator_disconnect, mem); 326 327 mutex_unlock(&mem_id_lock); 328 329 return xdp_alloc; 330 err: 331 mutex_unlock(&mem_id_lock); 332 kfree(xdp_alloc); 333 return ERR_PTR(errno); 334 } 335 336 int xdp_reg_mem_model(struct xdp_mem_info *mem, 337 enum xdp_mem_type type, void *allocator) 338 { 339 struct xdp_mem_allocator *xdp_alloc; 340 341 xdp_alloc = __xdp_reg_mem_model(mem, type, allocator); 342 if (IS_ERR(xdp_alloc)) 343 return PTR_ERR(xdp_alloc); 344 return 0; 345 } 346 EXPORT_SYMBOL_GPL(xdp_reg_mem_model); 347 348 int xdp_rxq_info_reg_mem_model(struct xdp_rxq_info *xdp_rxq, 349 enum xdp_mem_type type, void *allocator) 350 { 351 struct xdp_mem_allocator *xdp_alloc; 352 353 if (xdp_rxq->reg_state != REG_STATE_REGISTERED) { 354 WARN(1, "Missing register, driver bug"); 355 return -EFAULT; 356 } 357 358 xdp_alloc = __xdp_reg_mem_model(&xdp_rxq->mem, type, allocator); 359 if (IS_ERR(xdp_alloc)) 360 return PTR_ERR(xdp_alloc); 361 362 if (trace_mem_connect_enabled() && xdp_alloc) 363 trace_mem_connect(xdp_alloc, xdp_rxq); 364 return 0; 365 } 366 367 EXPORT_SYMBOL_GPL(xdp_rxq_info_reg_mem_model); 368 369 /* XDP RX runs under NAPI protection, and in different delivery error 370 * scenarios (e.g. queue full), it is possible to return the xdp_frame 371 * while still leveraging this protection. The @napi_direct boolean 372 * is used for those calls sites. Thus, allowing for faster recycling 373 * of xdp_frames/pages in those cases. 374 */ 375 void __xdp_return(void *data, struct xdp_mem_info *mem, bool napi_direct, 376 struct xdp_buff *xdp) 377 { 378 struct xdp_mem_allocator *xa; 379 struct page *page; 380 381 switch (mem->type) { 382 case MEM_TYPE_PAGE_POOL: 383 rcu_read_lock(); 384 /* mem->id is valid, checked in xdp_rxq_info_reg_mem_model() */ 385 xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params); 386 page = virt_to_head_page(data); 387 if (napi_direct && xdp_return_frame_no_direct()) 388 napi_direct = false; 389 page_pool_put_full_page(xa->page_pool, page, napi_direct); 390 rcu_read_unlock(); 391 break; 392 case MEM_TYPE_PAGE_SHARED: 393 page_frag_free(data); 394 break; 395 case MEM_TYPE_PAGE_ORDER0: 396 page = virt_to_page(data); /* Assumes order0 page*/ 397 put_page(page); 398 break; 399 case MEM_TYPE_XSK_BUFF_POOL: 400 /* NB! Only valid from an xdp_buff! */ 401 xsk_buff_free(xdp); 402 break; 403 default: 404 /* Not possible, checked in xdp_rxq_info_reg_mem_model() */ 405 WARN(1, "Incorrect XDP memory type (%d) usage", mem->type); 406 break; 407 } 408 } 409 410 void xdp_return_frame(struct xdp_frame *xdpf) 411 { 412 struct skb_shared_info *sinfo; 413 int i; 414 415 if (likely(!xdp_frame_has_frags(xdpf))) 416 goto out; 417 418 sinfo = xdp_get_shared_info_from_frame(xdpf); 419 for (i = 0; i < sinfo->nr_frags; i++) { 420 struct page *page = skb_frag_page(&sinfo->frags[i]); 421 422 __xdp_return(page_address(page), &xdpf->mem, false, NULL); 423 } 424 out: 425 __xdp_return(xdpf->data, &xdpf->mem, false, NULL); 426 } 427 EXPORT_SYMBOL_GPL(xdp_return_frame); 428 429 void xdp_return_frame_rx_napi(struct xdp_frame *xdpf) 430 { 431 struct skb_shared_info *sinfo; 432 int i; 433 434 if (likely(!xdp_frame_has_frags(xdpf))) 435 goto out; 436 437 sinfo = xdp_get_shared_info_from_frame(xdpf); 438 for (i = 0; i < sinfo->nr_frags; i++) { 439 struct page *page = skb_frag_page(&sinfo->frags[i]); 440 441 __xdp_return(page_address(page), &xdpf->mem, true, NULL); 442 } 443 out: 444 __xdp_return(xdpf->data, &xdpf->mem, true, NULL); 445 } 446 EXPORT_SYMBOL_GPL(xdp_return_frame_rx_napi); 447 448 /* XDP bulk APIs introduce a defer/flush mechanism to return 449 * pages belonging to the same xdp_mem_allocator object 450 * (identified via the mem.id field) in bulk to optimize 451 * I-cache and D-cache. 452 * The bulk queue size is set to 16 to be aligned to how 453 * XDP_REDIRECT bulking works. The bulk is flushed when 454 * it is full or when mem.id changes. 455 * xdp_frame_bulk is usually stored/allocated on the function 456 * call-stack to avoid locking penalties. 457 */ 458 void xdp_flush_frame_bulk(struct xdp_frame_bulk *bq) 459 { 460 struct xdp_mem_allocator *xa = bq->xa; 461 462 if (unlikely(!xa || !bq->count)) 463 return; 464 465 page_pool_put_page_bulk(xa->page_pool, bq->q, bq->count); 466 /* bq->xa is not cleared to save lookup, if mem.id same in next bulk */ 467 bq->count = 0; 468 } 469 EXPORT_SYMBOL_GPL(xdp_flush_frame_bulk); 470 471 /* Must be called with rcu_read_lock held */ 472 void xdp_return_frame_bulk(struct xdp_frame *xdpf, 473 struct xdp_frame_bulk *bq) 474 { 475 struct xdp_mem_info *mem = &xdpf->mem; 476 struct xdp_mem_allocator *xa; 477 478 if (mem->type != MEM_TYPE_PAGE_POOL) { 479 xdp_return_frame(xdpf); 480 return; 481 } 482 483 xa = bq->xa; 484 if (unlikely(!xa)) { 485 xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params); 486 bq->count = 0; 487 bq->xa = xa; 488 } 489 490 if (bq->count == XDP_BULK_QUEUE_SIZE) 491 xdp_flush_frame_bulk(bq); 492 493 if (unlikely(mem->id != xa->mem.id)) { 494 xdp_flush_frame_bulk(bq); 495 bq->xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params); 496 } 497 498 if (unlikely(xdp_frame_has_frags(xdpf))) { 499 struct skb_shared_info *sinfo; 500 int i; 501 502 sinfo = xdp_get_shared_info_from_frame(xdpf); 503 for (i = 0; i < sinfo->nr_frags; i++) { 504 skb_frag_t *frag = &sinfo->frags[i]; 505 506 bq->q[bq->count++] = skb_frag_address(frag); 507 if (bq->count == XDP_BULK_QUEUE_SIZE) 508 xdp_flush_frame_bulk(bq); 509 } 510 } 511 bq->q[bq->count++] = xdpf->data; 512 } 513 EXPORT_SYMBOL_GPL(xdp_return_frame_bulk); 514 515 void xdp_return_buff(struct xdp_buff *xdp) 516 { 517 struct skb_shared_info *sinfo; 518 int i; 519 520 if (likely(!xdp_buff_has_frags(xdp))) 521 goto out; 522 523 sinfo = xdp_get_shared_info_from_buff(xdp); 524 for (i = 0; i < sinfo->nr_frags; i++) { 525 struct page *page = skb_frag_page(&sinfo->frags[i]); 526 527 __xdp_return(page_address(page), &xdp->rxq->mem, true, xdp); 528 } 529 out: 530 __xdp_return(xdp->data, &xdp->rxq->mem, true, xdp); 531 } 532 EXPORT_SYMBOL_GPL(xdp_return_buff); 533 534 /* Only called for MEM_TYPE_PAGE_POOL see xdp.h */ 535 void __xdp_release_frame(void *data, struct xdp_mem_info *mem) 536 { 537 struct xdp_mem_allocator *xa; 538 struct page *page; 539 540 rcu_read_lock(); 541 xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params); 542 page = virt_to_head_page(data); 543 if (xa) 544 page_pool_release_page(xa->page_pool, page); 545 rcu_read_unlock(); 546 } 547 EXPORT_SYMBOL_GPL(__xdp_release_frame); 548 549 void xdp_attachment_setup(struct xdp_attachment_info *info, 550 struct netdev_bpf *bpf) 551 { 552 if (info->prog) 553 bpf_prog_put(info->prog); 554 info->prog = bpf->prog; 555 info->flags = bpf->flags; 556 } 557 EXPORT_SYMBOL_GPL(xdp_attachment_setup); 558 559 struct xdp_frame *xdp_convert_zc_to_xdp_frame(struct xdp_buff *xdp) 560 { 561 unsigned int metasize, totsize; 562 void *addr, *data_to_copy; 563 struct xdp_frame *xdpf; 564 struct page *page; 565 566 /* Clone into a MEM_TYPE_PAGE_ORDER0 xdp_frame. */ 567 metasize = xdp_data_meta_unsupported(xdp) ? 0 : 568 xdp->data - xdp->data_meta; 569 totsize = xdp->data_end - xdp->data + metasize; 570 571 if (sizeof(*xdpf) + totsize > PAGE_SIZE) 572 return NULL; 573 574 page = dev_alloc_page(); 575 if (!page) 576 return NULL; 577 578 addr = page_to_virt(page); 579 xdpf = addr; 580 memset(xdpf, 0, sizeof(*xdpf)); 581 582 addr += sizeof(*xdpf); 583 data_to_copy = metasize ? xdp->data_meta : xdp->data; 584 memcpy(addr, data_to_copy, totsize); 585 586 xdpf->data = addr + metasize; 587 xdpf->len = totsize - metasize; 588 xdpf->headroom = 0; 589 xdpf->metasize = metasize; 590 xdpf->frame_sz = PAGE_SIZE; 591 xdpf->mem.type = MEM_TYPE_PAGE_ORDER0; 592 593 xsk_buff_free(xdp); 594 return xdpf; 595 } 596 EXPORT_SYMBOL_GPL(xdp_convert_zc_to_xdp_frame); 597 598 /* Used by XDP_WARN macro, to avoid inlining WARN() in fast-path */ 599 void xdp_warn(const char *msg, const char *func, const int line) 600 { 601 WARN(1, "XDP_WARN: %s(line:%d): %s\n", func, line, msg); 602 }; 603 EXPORT_SYMBOL_GPL(xdp_warn); 604 605 int xdp_alloc_skb_bulk(void **skbs, int n_skb, gfp_t gfp) 606 { 607 n_skb = kmem_cache_alloc_bulk(skbuff_head_cache, gfp, 608 n_skb, skbs); 609 if (unlikely(!n_skb)) 610 return -ENOMEM; 611 612 return 0; 613 } 614 EXPORT_SYMBOL_GPL(xdp_alloc_skb_bulk); 615 616 struct sk_buff *__xdp_build_skb_from_frame(struct xdp_frame *xdpf, 617 struct sk_buff *skb, 618 struct net_device *dev) 619 { 620 struct skb_shared_info *sinfo = xdp_get_shared_info_from_frame(xdpf); 621 unsigned int headroom, frame_size; 622 void *hard_start; 623 u8 nr_frags; 624 625 /* xdp frags frame */ 626 if (unlikely(xdp_frame_has_frags(xdpf))) 627 nr_frags = sinfo->nr_frags; 628 629 /* Part of headroom was reserved to xdpf */ 630 headroom = sizeof(*xdpf) + xdpf->headroom; 631 632 /* Memory size backing xdp_frame data already have reserved 633 * room for build_skb to place skb_shared_info in tailroom. 634 */ 635 frame_size = xdpf->frame_sz; 636 637 hard_start = xdpf->data - headroom; 638 skb = build_skb_around(skb, hard_start, frame_size); 639 if (unlikely(!skb)) 640 return NULL; 641 642 skb_reserve(skb, headroom); 643 __skb_put(skb, xdpf->len); 644 if (xdpf->metasize) 645 skb_metadata_set(skb, xdpf->metasize); 646 647 if (unlikely(xdp_frame_has_frags(xdpf))) 648 xdp_update_skb_shared_info(skb, nr_frags, 649 sinfo->xdp_frags_size, 650 nr_frags * xdpf->frame_sz, 651 xdp_frame_is_frag_pfmemalloc(xdpf)); 652 653 /* Essential SKB info: protocol and skb->dev */ 654 skb->protocol = eth_type_trans(skb, dev); 655 656 /* Optional SKB info, currently missing: 657 * - HW checksum info (skb->ip_summed) 658 * - HW RX hash (skb_set_hash) 659 * - RX ring dev queue index (skb_record_rx_queue) 660 */ 661 662 /* Until page_pool get SKB return path, release DMA here */ 663 xdp_release_frame(xdpf); 664 665 /* Allow SKB to reuse area used by xdp_frame */ 666 xdp_scrub_frame(xdpf); 667 668 return skb; 669 } 670 EXPORT_SYMBOL_GPL(__xdp_build_skb_from_frame); 671 672 struct sk_buff *xdp_build_skb_from_frame(struct xdp_frame *xdpf, 673 struct net_device *dev) 674 { 675 struct sk_buff *skb; 676 677 skb = kmem_cache_alloc(skbuff_head_cache, GFP_ATOMIC); 678 if (unlikely(!skb)) 679 return NULL; 680 681 memset(skb, 0, offsetof(struct sk_buff, tail)); 682 683 return __xdp_build_skb_from_frame(xdpf, skb, dev); 684 } 685 EXPORT_SYMBOL_GPL(xdp_build_skb_from_frame); 686 687 struct xdp_frame *xdpf_clone(struct xdp_frame *xdpf) 688 { 689 unsigned int headroom, totalsize; 690 struct xdp_frame *nxdpf; 691 struct page *page; 692 void *addr; 693 694 headroom = xdpf->headroom + sizeof(*xdpf); 695 totalsize = headroom + xdpf->len; 696 697 if (unlikely(totalsize > PAGE_SIZE)) 698 return NULL; 699 page = dev_alloc_page(); 700 if (!page) 701 return NULL; 702 addr = page_to_virt(page); 703 704 memcpy(addr, xdpf, totalsize); 705 706 nxdpf = addr; 707 nxdpf->data = addr + headroom; 708 nxdpf->frame_sz = PAGE_SIZE; 709 nxdpf->mem.type = MEM_TYPE_PAGE_ORDER0; 710 nxdpf->mem.id = 0; 711 712 return nxdpf; 713 } 714