1 // SPDX-License-Identifier: GPL-2.0-or-later 2 #include <net/psp.h> 3 #include <net/gro.h> 4 #include <net/dst_metadata.h> 5 #include <net/busy_poll.h> 6 #include <trace/events/net.h> 7 #include <linux/skbuff_ref.h> 8 9 #define MAX_GRO_SKBS 8 10 11 static DEFINE_SPINLOCK(offload_lock); 12 13 /** 14 * dev_add_offload - register offload handlers 15 * @po: protocol offload declaration 16 * 17 * Add protocol offload handlers to the networking stack. The passed 18 * &proto_offload is linked into kernel lists and may not be freed until 19 * it has been removed from the kernel lists. 20 * 21 * This call does not sleep therefore it can not 22 * guarantee all CPU's that are in middle of receiving packets 23 * will see the new offload handlers (until the next received packet). 24 */ 25 void dev_add_offload(struct packet_offload *po) 26 { 27 struct packet_offload *elem; 28 29 spin_lock(&offload_lock); 30 list_for_each_entry(elem, &net_hotdata.offload_base, list) { 31 if (po->priority < elem->priority) 32 break; 33 } 34 list_add_rcu(&po->list, elem->list.prev); 35 spin_unlock(&offload_lock); 36 } 37 EXPORT_SYMBOL(dev_add_offload); 38 39 /** 40 * __dev_remove_offload - remove offload handler 41 * @po: packet offload declaration 42 * 43 * Remove a protocol offload handler that was previously added to the 44 * kernel offload handlers by dev_add_offload(). The passed &offload_type 45 * is removed from the kernel lists and can be freed or reused once this 46 * function returns. 47 * 48 * The packet type might still be in use by receivers 49 * and must not be freed until after all the CPU's have gone 50 * through a quiescent state. 51 */ 52 static void __dev_remove_offload(struct packet_offload *po) 53 { 54 struct list_head *head = &net_hotdata.offload_base; 55 struct packet_offload *po1; 56 57 spin_lock(&offload_lock); 58 59 list_for_each_entry(po1, head, list) { 60 if (po == po1) { 61 list_del_rcu(&po->list); 62 goto out; 63 } 64 } 65 66 pr_warn("dev_remove_offload: %p not found\n", po); 67 out: 68 spin_unlock(&offload_lock); 69 } 70 71 /** 72 * dev_remove_offload - remove packet offload handler 73 * @po: packet offload declaration 74 * 75 * Remove a packet offload handler that was previously added to the kernel 76 * offload handlers by dev_add_offload(). The passed &offload_type is 77 * removed from the kernel lists and can be freed or reused once this 78 * function returns. 79 * 80 * This call sleeps to guarantee that no CPU is looking at the packet 81 * type after return. 82 */ 83 void dev_remove_offload(struct packet_offload *po) 84 { 85 __dev_remove_offload(po); 86 87 synchronize_net(); 88 } 89 EXPORT_SYMBOL(dev_remove_offload); 90 91 92 int skb_gro_receive(struct sk_buff *p, struct sk_buff *skb) 93 { 94 struct skb_shared_info *pinfo, *skbinfo = skb_shinfo(skb); 95 unsigned int offset = skb_gro_offset(skb); 96 unsigned int headlen = skb_headlen(skb); 97 unsigned int len = skb_gro_len(skb); 98 unsigned int delta_truesize; 99 unsigned int new_truesize; 100 struct sk_buff *lp; 101 int segs; 102 103 /* Do not splice page pool based packets w/ non-page pool 104 * packets. This can result in reference count issues as page 105 * pool pages will not decrement the reference count and will 106 * instead be immediately returned to the pool or have frag 107 * count decremented. 108 */ 109 if (p->pp_recycle != skb->pp_recycle) 110 return -ETOOMANYREFS; 111 112 if (skb_zcopy(p) || skb_zcopy(skb)) 113 return -ETOOMANYREFS; 114 115 if (unlikely(p->len + len >= netif_get_gro_max_size(p->dev, p) || 116 NAPI_GRO_CB(skb)->flush)) 117 return -E2BIG; 118 119 if (unlikely(p->len + len >= GRO_LEGACY_MAX_SIZE)) { 120 if (NAPI_GRO_CB(skb)->proto != IPPROTO_TCP || 121 p->encapsulation) 122 return -E2BIG; 123 } 124 125 segs = NAPI_GRO_CB(skb)->count; 126 lp = NAPI_GRO_CB(p)->last; 127 pinfo = skb_shinfo(lp); 128 129 if (headlen <= offset) { 130 skb_frag_t *frag; 131 skb_frag_t *frag2; 132 int i = skbinfo->nr_frags; 133 int nr_frags = pinfo->nr_frags + i; 134 135 if (nr_frags > MAX_SKB_FRAGS) 136 goto merge; 137 138 offset -= headlen; 139 pinfo->nr_frags = nr_frags; 140 skbinfo->nr_frags = 0; 141 142 frag = pinfo->frags + nr_frags; 143 frag2 = skbinfo->frags + i; 144 do { 145 *--frag = *--frag2; 146 } while (--i); 147 148 skb_frag_off_add(frag, offset); 149 skb_frag_size_sub(frag, offset); 150 151 /* all fragments truesize : remove (head size + sk_buff) */ 152 new_truesize = SKB_TRUESIZE(skb_end_offset(skb)); 153 delta_truesize = skb->truesize - new_truesize; 154 155 skb->truesize = new_truesize; 156 skb->len -= skb->data_len; 157 skb->data_len = 0; 158 159 NAPI_GRO_CB(skb)->free = NAPI_GRO_FREE; 160 goto done; 161 } else if (skb->head_frag) { 162 int nr_frags = pinfo->nr_frags; 163 skb_frag_t *frag = pinfo->frags + nr_frags; 164 struct page *page = virt_to_head_page(skb->head); 165 unsigned int first_size = headlen - offset; 166 unsigned int first_offset; 167 168 if (nr_frags + 1 + skbinfo->nr_frags > MAX_SKB_FRAGS) 169 goto merge; 170 171 first_offset = skb->data - 172 (unsigned char *)page_address(page) + 173 offset; 174 175 pinfo->nr_frags = nr_frags + 1 + skbinfo->nr_frags; 176 177 skb_frag_fill_page_desc(frag, page, first_offset, first_size); 178 179 memcpy(frag + 1, skbinfo->frags, sizeof(*frag) * skbinfo->nr_frags); 180 /* We dont need to clear skbinfo->nr_frags here */ 181 182 new_truesize = SKB_DATA_ALIGN(sizeof(struct sk_buff)); 183 delta_truesize = skb->truesize - new_truesize; 184 skb->truesize = new_truesize; 185 NAPI_GRO_CB(skb)->free = NAPI_GRO_FREE_STOLEN_HEAD; 186 goto done; 187 } 188 189 merge: 190 /* sk ownership - if any - completely transferred to the aggregated packet */ 191 skb->destructor = NULL; 192 skb->sk = NULL; 193 delta_truesize = skb->truesize; 194 if (offset > headlen) { 195 unsigned int eat = offset - headlen; 196 197 skb_frag_off_add(&skbinfo->frags[0], eat); 198 skb_frag_size_sub(&skbinfo->frags[0], eat); 199 skb->data_len -= eat; 200 skb->len -= eat; 201 offset = headlen; 202 } 203 204 __skb_pull(skb, offset); 205 206 if (NAPI_GRO_CB(p)->last == p) 207 skb_shinfo(p)->frag_list = skb; 208 else 209 NAPI_GRO_CB(p)->last->next = skb; 210 NAPI_GRO_CB(p)->last = skb; 211 __skb_header_release(skb); 212 lp = p; 213 214 done: 215 NAPI_GRO_CB(p)->count += segs; 216 p->data_len += len; 217 p->truesize += delta_truesize; 218 p->len += len; 219 skb_shinfo(p)->flags |= skbinfo->flags & SKBFL_SHARED_FRAG; 220 if (lp != p) { 221 lp->data_len += len; 222 lp->truesize += delta_truesize; 223 lp->len += len; 224 skb_shinfo(lp)->flags |= skbinfo->flags & SKBFL_SHARED_FRAG; 225 } 226 NAPI_GRO_CB(skb)->same_flow = 1; 227 return 0; 228 } 229 230 int skb_gro_receive_list(struct sk_buff *p, struct sk_buff *skb) 231 { 232 if (unlikely(p->len + skb->len >= 65536)) 233 return -E2BIG; 234 235 if (!pskb_may_pull(skb, skb_gro_offset(skb))) { 236 NAPI_GRO_CB(skb)->flush = 1; 237 return -ENOMEM; 238 } 239 240 if (NAPI_GRO_CB(p)->last == p) 241 skb_shinfo(p)->frag_list = skb; 242 else 243 NAPI_GRO_CB(p)->last->next = skb; 244 245 skb_pull(skb, skb_gro_offset(skb)); 246 247 NAPI_GRO_CB(p)->last = skb; 248 NAPI_GRO_CB(p)->count++; 249 p->data_len += skb->len; 250 251 /* sk ownership - if any - completely transferred to the aggregated packet */ 252 skb->destructor = NULL; 253 skb->sk = NULL; 254 p->truesize += skb->truesize; 255 p->len += skb->len; 256 257 skb_shinfo(p)->flags |= skb_shinfo(skb)->flags & SKBFL_SHARED_FRAG; 258 259 NAPI_GRO_CB(skb)->same_flow = 1; 260 261 return 0; 262 } 263 264 static void gro_complete(struct gro_node *gro, struct sk_buff *skb) 265 { 266 struct list_head *head = &net_hotdata.offload_base; 267 struct packet_offload *ptype; 268 __be16 type = skb->protocol; 269 int err = -ENOENT; 270 271 BUILD_BUG_ON(sizeof(struct napi_gro_cb) > sizeof(skb->cb)); 272 273 if (NAPI_GRO_CB(skb)->count == 1) { 274 skb_shinfo(skb)->gso_size = 0; 275 goto out; 276 } 277 278 /* NICs can feed encapsulated packets into GRO */ 279 skb->encapsulation = 0; 280 rcu_read_lock(); 281 list_for_each_entry_rcu(ptype, head, list) { 282 if (ptype->type != type || !ptype->callbacks.gro_complete) 283 continue; 284 285 err = INDIRECT_CALL_INET(ptype->callbacks.gro_complete, 286 ipv6_gro_complete, inet_gro_complete, 287 skb, 0); 288 break; 289 } 290 rcu_read_unlock(); 291 292 if (err) { 293 WARN_ON(&ptype->list == head); 294 kfree_skb(skb); 295 return; 296 } 297 298 out: 299 gro_normal_one(gro, skb, NAPI_GRO_CB(skb)->count); 300 } 301 302 static void __gro_flush_chain(struct gro_node *gro, u32 index, bool flush_old) 303 { 304 struct list_head *head = &gro->hash[index].list; 305 struct sk_buff *skb, *p; 306 307 list_for_each_entry_safe_reverse(skb, p, head, list) { 308 if (flush_old && NAPI_GRO_CB(skb)->age == jiffies) 309 return; 310 skb_list_del_init(skb); 311 gro_complete(gro, skb); 312 gro->hash[index].count--; 313 } 314 315 if (!gro->hash[index].count) 316 __clear_bit(index, &gro->bitmask); 317 } 318 319 /* 320 * gro->hash[].list contains packets ordered by age. 321 * youngest packets at the head of it. 322 * Complete skbs in reverse order to reduce latencies. 323 */ 324 void __gro_flush(struct gro_node *gro, bool flush_old) 325 { 326 unsigned long bitmask = gro->bitmask; 327 unsigned int i, base = ~0U; 328 329 while ((i = ffs(bitmask)) != 0) { 330 bitmask >>= i; 331 base += i; 332 __gro_flush_chain(gro, base, flush_old); 333 } 334 } 335 EXPORT_SYMBOL(__gro_flush); 336 337 static unsigned long gro_list_prepare_tc_ext(const struct sk_buff *skb, 338 const struct sk_buff *p, 339 unsigned long diffs) 340 { 341 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT) 342 struct tc_skb_ext *skb_ext; 343 struct tc_skb_ext *p_ext; 344 345 skb_ext = skb_ext_find(skb, TC_SKB_EXT); 346 p_ext = skb_ext_find(p, TC_SKB_EXT); 347 348 diffs |= (!!p_ext) ^ (!!skb_ext); 349 if (!diffs && unlikely(skb_ext)) 350 diffs |= p_ext->chain ^ skb_ext->chain; 351 #endif 352 return diffs; 353 } 354 355 static void gro_list_prepare(const struct list_head *head, 356 const struct sk_buff *skb) 357 { 358 unsigned int maclen = skb->dev->hard_header_len; 359 u32 hash = skb_get_hash_raw(skb); 360 struct sk_buff *p; 361 362 list_for_each_entry(p, head, list) { 363 unsigned long diffs; 364 365 if (hash != skb_get_hash_raw(p)) { 366 NAPI_GRO_CB(p)->same_flow = 0; 367 continue; 368 } 369 370 diffs = (unsigned long)p->dev ^ (unsigned long)skb->dev; 371 diffs |= p->vlan_all ^ skb->vlan_all; 372 diffs |= skb_metadata_differs(p, skb); 373 if (maclen == ETH_HLEN) 374 diffs |= compare_ether_header(skb_mac_header(p), 375 skb_mac_header(skb)); 376 else if (!diffs) 377 diffs = memcmp(skb_mac_header(p), 378 skb_mac_header(skb), 379 maclen); 380 381 /* in most common scenarios 'slow_gro' is 0 382 * otherwise we are already on some slower paths 383 * either skip all the infrequent tests altogether or 384 * avoid trying too hard to skip each of them individually 385 */ 386 if (!diffs && unlikely(skb->slow_gro | p->slow_gro)) { 387 diffs |= p->sk != skb->sk; 388 diffs |= skb_metadata_dst_cmp(p, skb); 389 diffs |= skb_get_nfct(p) ^ skb_get_nfct(skb); 390 391 diffs |= gro_list_prepare_tc_ext(skb, p, diffs); 392 diffs |= __psp_skb_coalesce_diff(skb, p, diffs); 393 } 394 395 NAPI_GRO_CB(p)->same_flow = !diffs; 396 } 397 } 398 399 static inline void skb_gro_reset_offset(struct sk_buff *skb, u32 nhoff) 400 { 401 const struct skb_shared_info *pinfo; 402 const skb_frag_t *frag0; 403 unsigned int headlen; 404 405 NAPI_GRO_CB(skb)->network_offset = 0; 406 NAPI_GRO_CB(skb)->data_offset = 0; 407 headlen = skb_headlen(skb); 408 NAPI_GRO_CB(skb)->frag0 = skb->data; 409 NAPI_GRO_CB(skb)->frag0_len = headlen; 410 if (headlen) 411 return; 412 413 pinfo = skb_shinfo(skb); 414 frag0 = &pinfo->frags[0]; 415 416 if (pinfo->nr_frags && skb_frag_page(frag0) && 417 !PageHighMem(skb_frag_page(frag0)) && 418 (!NET_IP_ALIGN || !((skb_frag_off(frag0) + nhoff) & 3))) { 419 NAPI_GRO_CB(skb)->frag0 = skb_frag_address(frag0); 420 NAPI_GRO_CB(skb)->frag0_len = min_t(unsigned int, 421 skb_frag_size(frag0), 422 skb->end - skb->tail); 423 } 424 } 425 426 static void gro_pull_from_frag0(struct sk_buff *skb, int grow) 427 { 428 struct skb_shared_info *pinfo = skb_shinfo(skb); 429 430 DEBUG_NET_WARN_ON_ONCE(skb->end - skb->tail < grow); 431 432 memcpy(skb_tail_pointer(skb), NAPI_GRO_CB(skb)->frag0, grow); 433 434 skb->data_len -= grow; 435 skb->tail += grow; 436 437 skb_frag_off_add(&pinfo->frags[0], grow); 438 skb_frag_size_sub(&pinfo->frags[0], grow); 439 440 if (unlikely(!skb_frag_size(&pinfo->frags[0]))) { 441 skb_frag_unref(skb, 0); 442 memmove(pinfo->frags, pinfo->frags + 1, 443 --pinfo->nr_frags * sizeof(pinfo->frags[0])); 444 } 445 } 446 447 static void gro_try_pull_from_frag0(struct sk_buff *skb) 448 { 449 int grow = skb_gro_offset(skb) - skb_headlen(skb); 450 451 if (grow > 0) 452 gro_pull_from_frag0(skb, grow); 453 } 454 455 static void gro_flush_oldest(struct gro_node *gro, struct list_head *head) 456 { 457 struct sk_buff *oldest; 458 459 oldest = list_last_entry(head, struct sk_buff, list); 460 461 /* We are called with head length >= MAX_GRO_SKBS, so this is 462 * impossible. 463 */ 464 if (WARN_ON_ONCE(!oldest)) 465 return; 466 467 /* Do not adjust napi->gro_hash[].count, caller is adding a new 468 * SKB to the chain. 469 */ 470 skb_list_del_init(oldest); 471 gro_complete(gro, oldest); 472 } 473 474 static enum gro_result dev_gro_receive(struct gro_node *gro, 475 struct sk_buff *skb) 476 { 477 u32 bucket = skb_get_hash_raw(skb) & (GRO_HASH_BUCKETS - 1); 478 struct list_head *head = &net_hotdata.offload_base; 479 struct gro_list *gro_list = &gro->hash[bucket]; 480 struct packet_offload *ptype; 481 __be16 type = skb->protocol; 482 struct sk_buff *pp = NULL; 483 enum gro_result ret; 484 int same_flow; 485 486 if (netif_elide_gro(skb->dev)) 487 goto normal; 488 489 gro_list_prepare(&gro_list->list, skb); 490 491 rcu_read_lock(); 492 list_for_each_entry_rcu(ptype, head, list) { 493 if (ptype->type == type && ptype->callbacks.gro_receive) 494 goto found_ptype; 495 } 496 rcu_read_unlock(); 497 goto normal; 498 499 found_ptype: 500 skb_set_network_header(skb, skb_gro_offset(skb)); 501 skb_reset_mac_len(skb); 502 BUILD_BUG_ON(sizeof_field(struct napi_gro_cb, zeroed) != sizeof(u32)); 503 BUILD_BUG_ON(!IS_ALIGNED(offsetof(struct napi_gro_cb, zeroed), 504 sizeof(u32))); /* Avoid slow unaligned acc */ 505 *(u32 *)&NAPI_GRO_CB(skb)->zeroed = 0; 506 NAPI_GRO_CB(skb)->flush = skb_has_frag_list(skb); 507 NAPI_GRO_CB(skb)->count = 1; 508 if (unlikely(skb_is_gso(skb))) { 509 NAPI_GRO_CB(skb)->count = skb_shinfo(skb)->gso_segs; 510 /* Only support TCP and non DODGY users. */ 511 if (!skb_is_gso_tcp(skb) || 512 (skb_shinfo(skb)->gso_type & SKB_GSO_DODGY)) 513 NAPI_GRO_CB(skb)->flush = 1; 514 } 515 516 /* Setup for GRO checksum validation */ 517 switch (skb->ip_summed) { 518 case CHECKSUM_COMPLETE: 519 NAPI_GRO_CB(skb)->csum = skb->csum; 520 NAPI_GRO_CB(skb)->csum_valid = 1; 521 break; 522 case CHECKSUM_UNNECESSARY: 523 NAPI_GRO_CB(skb)->csum_cnt = skb->csum_level + 1; 524 break; 525 } 526 527 pp = INDIRECT_CALL_INET(ptype->callbacks.gro_receive, 528 ipv6_gro_receive, inet_gro_receive, 529 &gro_list->list, skb); 530 531 rcu_read_unlock(); 532 533 if (PTR_ERR(pp) == -EINPROGRESS) { 534 ret = GRO_CONSUMED; 535 goto ok; 536 } 537 538 same_flow = NAPI_GRO_CB(skb)->same_flow; 539 ret = NAPI_GRO_CB(skb)->free ? GRO_MERGED_FREE : GRO_MERGED; 540 541 if (pp) { 542 skb_list_del_init(pp); 543 gro_complete(gro, pp); 544 gro_list->count--; 545 } 546 547 if (same_flow) 548 goto ok; 549 550 if (NAPI_GRO_CB(skb)->flush) 551 goto normal; 552 553 if (unlikely(gro_list->count >= MAX_GRO_SKBS)) 554 gro_flush_oldest(gro, &gro_list->list); 555 else 556 gro_list->count++; 557 558 /* Must be called before setting NAPI_GRO_CB(skb)->{age|last} */ 559 gro_try_pull_from_frag0(skb); 560 NAPI_GRO_CB(skb)->age = jiffies; 561 NAPI_GRO_CB(skb)->last = skb; 562 if (!skb_is_gso(skb)) 563 skb_shinfo(skb)->gso_size = skb_gro_len(skb); 564 list_add(&skb->list, &gro_list->list); 565 ret = GRO_HELD; 566 ok: 567 if (gro_list->count) { 568 if (!test_bit(bucket, &gro->bitmask)) 569 __set_bit(bucket, &gro->bitmask); 570 } else if (test_bit(bucket, &gro->bitmask)) { 571 __clear_bit(bucket, &gro->bitmask); 572 } 573 574 return ret; 575 576 normal: 577 ret = GRO_NORMAL; 578 gro_try_pull_from_frag0(skb); 579 goto ok; 580 } 581 582 struct packet_offload *gro_find_receive_by_type(__be16 type) 583 { 584 struct list_head *offload_head = &net_hotdata.offload_base; 585 struct packet_offload *ptype; 586 587 list_for_each_entry_rcu(ptype, offload_head, list) { 588 if (ptype->type != type || !ptype->callbacks.gro_receive) 589 continue; 590 return ptype; 591 } 592 return NULL; 593 } 594 EXPORT_SYMBOL(gro_find_receive_by_type); 595 596 struct packet_offload *gro_find_complete_by_type(__be16 type) 597 { 598 struct list_head *offload_head = &net_hotdata.offload_base; 599 struct packet_offload *ptype; 600 601 list_for_each_entry_rcu(ptype, offload_head, list) { 602 if (ptype->type != type || !ptype->callbacks.gro_complete) 603 continue; 604 return ptype; 605 } 606 return NULL; 607 } 608 EXPORT_SYMBOL(gro_find_complete_by_type); 609 610 static gro_result_t gro_skb_finish(struct gro_node *gro, struct sk_buff *skb, 611 gro_result_t ret) 612 { 613 switch (ret) { 614 case GRO_NORMAL: 615 gro_normal_one(gro, skb, 1); 616 break; 617 618 case GRO_MERGED_FREE: 619 if (NAPI_GRO_CB(skb)->free == NAPI_GRO_FREE_STOLEN_HEAD) 620 napi_skb_free_stolen_head(skb); 621 else if (skb->fclone != SKB_FCLONE_UNAVAILABLE) 622 __kfree_skb(skb); 623 else 624 __napi_kfree_skb(skb, SKB_CONSUMED); 625 break; 626 627 case GRO_HELD: 628 case GRO_MERGED: 629 case GRO_CONSUMED: 630 break; 631 } 632 633 return ret; 634 } 635 636 gro_result_t gro_receive_skb(struct gro_node *gro, struct sk_buff *skb) 637 { 638 gro_result_t ret; 639 640 __skb_mark_napi_id(skb, gro); 641 trace_napi_gro_receive_entry(skb); 642 643 skb_gro_reset_offset(skb, 0); 644 645 ret = gro_skb_finish(gro, skb, dev_gro_receive(gro, skb)); 646 trace_napi_gro_receive_exit(ret); 647 648 return ret; 649 } 650 EXPORT_SYMBOL(gro_receive_skb); 651 652 static void napi_reuse_skb(struct napi_struct *napi, struct sk_buff *skb) 653 { 654 struct skb_shared_info *shinfo; 655 656 if (unlikely(skb->pfmemalloc)) { 657 consume_skb(skb); 658 return; 659 } 660 __skb_pull(skb, skb_headlen(skb)); 661 /* restore the reserve we had after netdev_alloc_skb_ip_align() */ 662 skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN - skb_headroom(skb)); 663 __vlan_hwaccel_clear_tag(skb); 664 skb->dev = napi->dev; 665 skb->skb_iif = 0; 666 667 /* eth_type_trans() assumes pkt_type is PACKET_HOST */ 668 skb->pkt_type = PACKET_HOST; 669 670 skb->encapsulation = 0; 671 skb->ip_summed = CHECKSUM_NONE; 672 673 shinfo = skb_shinfo(skb); 674 shinfo->gso_type = 0; 675 shinfo->gso_size = 0; 676 shinfo->hwtstamps.hwtstamp = 0; 677 678 if (unlikely(skb->slow_gro)) { 679 skb_orphan(skb); 680 skb_ext_reset(skb); 681 nf_reset_ct(skb); 682 skb->slow_gro = 0; 683 } 684 685 napi->skb = skb; 686 } 687 688 struct sk_buff *napi_get_frags(struct napi_struct *napi) 689 { 690 struct sk_buff *skb = napi->skb; 691 692 if (!skb) { 693 skb = napi_alloc_skb(napi, GRO_MAX_HEAD); 694 if (skb) { 695 napi->skb = skb; 696 skb_mark_napi_id(skb, napi); 697 } 698 } 699 return skb; 700 } 701 EXPORT_SYMBOL(napi_get_frags); 702 703 static gro_result_t napi_frags_finish(struct napi_struct *napi, 704 struct sk_buff *skb, 705 gro_result_t ret) 706 { 707 switch (ret) { 708 case GRO_NORMAL: 709 case GRO_HELD: 710 __skb_push(skb, ETH_HLEN); 711 skb->protocol = eth_type_trans(skb, skb->dev); 712 if (ret == GRO_NORMAL) 713 gro_normal_one(&napi->gro, skb, 1); 714 break; 715 716 case GRO_MERGED_FREE: 717 if (NAPI_GRO_CB(skb)->free == NAPI_GRO_FREE_STOLEN_HEAD) 718 napi_skb_free_stolen_head(skb); 719 else 720 napi_reuse_skb(napi, skb); 721 break; 722 723 case GRO_MERGED: 724 case GRO_CONSUMED: 725 break; 726 } 727 728 return ret; 729 } 730 731 /* Upper GRO stack assumes network header starts at gro_offset=0 732 * Drivers could call both napi_gro_frags() and napi_gro_receive() 733 * We copy ethernet header into skb->data to have a common layout. 734 */ 735 static struct sk_buff *napi_frags_skb(struct napi_struct *napi) 736 { 737 struct sk_buff *skb = napi->skb; 738 const struct ethhdr *eth; 739 unsigned int hlen = sizeof(*eth); 740 741 napi->skb = NULL; 742 743 skb_reset_mac_header(skb); 744 skb_gro_reset_offset(skb, hlen); 745 746 if (unlikely(!skb_gro_may_pull(skb, hlen))) { 747 eth = skb_gro_header_slow(skb, hlen, 0); 748 if (unlikely(!eth)) { 749 net_warn_ratelimited("%s: dropping impossible skb from %s\n", 750 __func__, napi->dev->name); 751 napi_reuse_skb(napi, skb); 752 return NULL; 753 } 754 } else { 755 eth = (const struct ethhdr *)skb->data; 756 757 if (NAPI_GRO_CB(skb)->frag0 != skb->data) 758 gro_pull_from_frag0(skb, hlen); 759 760 NAPI_GRO_CB(skb)->frag0 += hlen; 761 NAPI_GRO_CB(skb)->frag0_len -= hlen; 762 } 763 __skb_pull(skb, hlen); 764 765 /* 766 * This works because the only protocols we care about don't require 767 * special handling. 768 * We'll fix it up properly in napi_frags_finish() 769 */ 770 skb->protocol = eth->h_proto; 771 772 return skb; 773 } 774 775 gro_result_t napi_gro_frags(struct napi_struct *napi) 776 { 777 gro_result_t ret; 778 struct sk_buff *skb = napi_frags_skb(napi); 779 780 trace_napi_gro_frags_entry(skb); 781 782 ret = napi_frags_finish(napi, skb, dev_gro_receive(&napi->gro, skb)); 783 trace_napi_gro_frags_exit(ret); 784 785 return ret; 786 } 787 EXPORT_SYMBOL(napi_gro_frags); 788 789 /* Compute the checksum from gro_offset and return the folded value 790 * after adding in any pseudo checksum. 791 */ 792 __sum16 __skb_gro_checksum_complete(struct sk_buff *skb) 793 { 794 __wsum wsum; 795 __sum16 sum; 796 797 wsum = skb_checksum(skb, skb_gro_offset(skb), skb_gro_len(skb), 0); 798 799 /* NAPI_GRO_CB(skb)->csum holds pseudo checksum */ 800 sum = csum_fold(csum_add(NAPI_GRO_CB(skb)->csum, wsum)); 801 /* See comments in __skb_checksum_complete(). */ 802 if (likely(!sum)) { 803 if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE) && 804 !skb->csum_complete_sw) 805 netdev_rx_csum_fault(skb->dev, skb); 806 } 807 808 NAPI_GRO_CB(skb)->csum = wsum; 809 NAPI_GRO_CB(skb)->csum_valid = 1; 810 811 return sum; 812 } 813 EXPORT_SYMBOL(__skb_gro_checksum_complete); 814 815 void gro_init(struct gro_node *gro) 816 { 817 for (u32 i = 0; i < GRO_HASH_BUCKETS; i++) { 818 INIT_LIST_HEAD(&gro->hash[i].list); 819 gro->hash[i].count = 0; 820 } 821 822 gro->bitmask = 0; 823 gro->cached_napi_id = 0; 824 825 INIT_LIST_HEAD(&gro->rx_list); 826 gro->rx_count = 0; 827 } 828 829 void gro_cleanup(struct gro_node *gro) 830 { 831 struct sk_buff *skb, *n; 832 833 for (u32 i = 0; i < GRO_HASH_BUCKETS; i++) { 834 list_for_each_entry_safe(skb, n, &gro->hash[i].list, list) 835 kfree_skb(skb); 836 837 gro->hash[i].count = 0; 838 } 839 840 gro->bitmask = 0; 841 gro->cached_napi_id = 0; 842 843 list_for_each_entry_safe(skb, n, &gro->rx_list, list) 844 kfree_skb(skb); 845 846 gro->rx_count = 0; 847 } 848