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 /* make sure to check flush flag and to not merge */ 233 if (unlikely(p->len + skb->len >= 65536 || 234 NAPI_GRO_CB(skb)->flush)) 235 return -E2BIG; 236 237 if (!pskb_may_pull(skb, skb_gro_offset(skb))) { 238 NAPI_GRO_CB(skb)->flush = 1; 239 return -ENOMEM; 240 } 241 242 if (NAPI_GRO_CB(p)->last == p) 243 skb_shinfo(p)->frag_list = skb; 244 else 245 NAPI_GRO_CB(p)->last->next = skb; 246 247 skb_pull(skb, skb_gro_offset(skb)); 248 249 NAPI_GRO_CB(p)->last = skb; 250 NAPI_GRO_CB(p)->count++; 251 p->data_len += skb->len; 252 253 /* sk ownership - if any - completely transferred to the aggregated packet */ 254 skb->destructor = NULL; 255 skb->sk = NULL; 256 p->truesize += skb->truesize; 257 p->len += skb->len; 258 259 skb_shinfo(p)->flags |= skb_shinfo(skb)->flags & SKBFL_SHARED_FRAG; 260 261 NAPI_GRO_CB(skb)->same_flow = 1; 262 263 return 0; 264 } 265 266 static void gro_complete(struct gro_node *gro, struct sk_buff *skb) 267 { 268 struct list_head *head = &net_hotdata.offload_base; 269 struct packet_offload *ptype; 270 __be16 type = skb->protocol; 271 int err = -ENOENT; 272 273 BUILD_BUG_ON(sizeof(struct napi_gro_cb) > sizeof(skb->cb)); 274 275 if (NAPI_GRO_CB(skb)->count == 1) { 276 skb_shinfo(skb)->gso_size = 0; 277 goto out; 278 } 279 280 /* NICs can feed encapsulated packets into GRO */ 281 skb->encapsulation = 0; 282 rcu_read_lock(); 283 list_for_each_entry_rcu(ptype, head, list) { 284 if (ptype->type != type || !ptype->callbacks.gro_complete) 285 continue; 286 287 err = INDIRECT_CALL_INET(ptype->callbacks.gro_complete, 288 ipv6_gro_complete, inet_gro_complete, 289 skb, 0); 290 break; 291 } 292 rcu_read_unlock(); 293 294 if (err) { 295 WARN_ON(&ptype->list == head); 296 kfree_skb(skb); 297 return; 298 } 299 300 out: 301 gro_normal_one(gro, skb, NAPI_GRO_CB(skb)->count); 302 } 303 304 static void __gro_flush_chain(struct gro_node *gro, u32 index, bool flush_old) 305 { 306 struct list_head *head = &gro->hash[index].list; 307 struct sk_buff *skb, *p; 308 309 list_for_each_entry_safe_reverse(skb, p, head, list) { 310 if (flush_old && NAPI_GRO_CB(skb)->age == jiffies) 311 return; 312 skb_list_del_init(skb); 313 gro_complete(gro, skb); 314 gro->hash[index].count--; 315 } 316 317 if (!gro->hash[index].count) 318 __clear_bit(index, &gro->bitmask); 319 } 320 321 /* 322 * gro->hash[].list contains packets ordered by age. 323 * youngest packets at the head of it. 324 * Complete skbs in reverse order to reduce latencies. 325 */ 326 void __gro_flush(struct gro_node *gro, bool flush_old) 327 { 328 unsigned long bitmask = gro->bitmask; 329 unsigned int i, base = ~0U; 330 331 while ((i = ffs(bitmask)) != 0) { 332 bitmask >>= i; 333 base += i; 334 __gro_flush_chain(gro, base, flush_old); 335 } 336 } 337 EXPORT_SYMBOL(__gro_flush); 338 339 static unsigned long gro_list_prepare_tc_ext(const struct sk_buff *skb, 340 const struct sk_buff *p, 341 unsigned long diffs) 342 { 343 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT) 344 struct tc_skb_ext *skb_ext; 345 struct tc_skb_ext *p_ext; 346 347 skb_ext = skb_ext_find(skb, TC_SKB_EXT); 348 p_ext = skb_ext_find(p, TC_SKB_EXT); 349 350 diffs |= (!!p_ext) ^ (!!skb_ext); 351 if (!diffs && unlikely(skb_ext)) 352 diffs |= p_ext->chain ^ skb_ext->chain; 353 #endif 354 return diffs; 355 } 356 357 static void gro_list_prepare(const struct list_head *head, 358 const struct sk_buff *skb) 359 { 360 unsigned int maclen = skb->dev->hard_header_len; 361 u32 hash = skb_get_hash_raw(skb); 362 struct sk_buff *p; 363 364 list_for_each_entry(p, head, list) { 365 unsigned long diffs; 366 367 if (hash != skb_get_hash_raw(p)) { 368 NAPI_GRO_CB(p)->same_flow = 0; 369 continue; 370 } 371 372 diffs = (unsigned long)p->dev ^ (unsigned long)skb->dev; 373 diffs |= p->vlan_all ^ skb->vlan_all; 374 diffs |= skb_metadata_differs(p, skb); 375 if (maclen == ETH_HLEN) 376 diffs |= compare_ether_header(skb_mac_header(p), 377 skb_mac_header(skb)); 378 else if (!diffs) 379 diffs = memcmp(skb_mac_header(p), 380 skb_mac_header(skb), 381 maclen); 382 383 /* in most common scenarios 'slow_gro' is 0 384 * otherwise we are already on some slower paths 385 * either skip all the infrequent tests altogether or 386 * avoid trying too hard to skip each of them individually 387 */ 388 if (!diffs && unlikely(skb->slow_gro | p->slow_gro)) { 389 diffs |= p->sk != skb->sk; 390 diffs |= skb_metadata_dst_cmp(p, skb); 391 diffs |= skb_get_nfct(p) ^ skb_get_nfct(skb); 392 393 diffs |= gro_list_prepare_tc_ext(skb, p, diffs); 394 diffs |= __psp_skb_coalesce_diff(skb, p, diffs); 395 } 396 397 NAPI_GRO_CB(p)->same_flow = !diffs; 398 } 399 } 400 401 static inline void skb_gro_reset_offset(struct sk_buff *skb, u32 nhoff) 402 { 403 const struct skb_shared_info *pinfo; 404 const skb_frag_t *frag0; 405 unsigned int headlen; 406 407 NAPI_GRO_CB(skb)->network_offset = 0; 408 NAPI_GRO_CB(skb)->data_offset = 0; 409 headlen = skb_headlen(skb); 410 NAPI_GRO_CB(skb)->frag0 = skb->data; 411 NAPI_GRO_CB(skb)->frag0_len = headlen; 412 if (headlen) 413 return; 414 415 pinfo = skb_shinfo(skb); 416 frag0 = &pinfo->frags[0]; 417 418 if (pinfo->nr_frags && skb_frag_page(frag0) && 419 !PageHighMem(skb_frag_page(frag0)) && 420 (!NET_IP_ALIGN || !((skb_frag_off(frag0) + nhoff) & 3))) { 421 NAPI_GRO_CB(skb)->frag0 = skb_frag_address(frag0); 422 NAPI_GRO_CB(skb)->frag0_len = min_t(unsigned int, 423 skb_frag_size(frag0), 424 skb->end - skb->tail); 425 } 426 } 427 428 static void gro_pull_from_frag0(struct sk_buff *skb, int grow) 429 { 430 struct skb_shared_info *pinfo = skb_shinfo(skb); 431 432 DEBUG_NET_WARN_ON_ONCE(skb->end - skb->tail < grow); 433 434 memcpy(skb_tail_pointer(skb), NAPI_GRO_CB(skb)->frag0, grow); 435 436 skb->data_len -= grow; 437 skb->tail += grow; 438 439 skb_frag_off_add(&pinfo->frags[0], grow); 440 skb_frag_size_sub(&pinfo->frags[0], grow); 441 442 if (unlikely(!skb_frag_size(&pinfo->frags[0]))) { 443 skb_frag_unref(skb, 0); 444 memmove(pinfo->frags, pinfo->frags + 1, 445 --pinfo->nr_frags * sizeof(pinfo->frags[0])); 446 } 447 } 448 449 static void gro_try_pull_from_frag0(struct sk_buff *skb) 450 { 451 int grow = skb_gro_offset(skb) - skb_headlen(skb); 452 453 if (grow > 0) 454 gro_pull_from_frag0(skb, grow); 455 } 456 457 static void gro_flush_oldest(struct gro_node *gro, struct list_head *head) 458 { 459 struct sk_buff *oldest; 460 461 oldest = list_last_entry(head, struct sk_buff, list); 462 463 /* We are called with head length >= MAX_GRO_SKBS, so this is 464 * impossible. 465 */ 466 if (WARN_ON_ONCE(!oldest)) 467 return; 468 469 /* Do not adjust napi->gro_hash[].count, caller is adding a new 470 * SKB to the chain. 471 */ 472 skb_list_del_init(oldest); 473 gro_complete(gro, oldest); 474 } 475 476 static enum gro_result dev_gro_receive(struct gro_node *gro, 477 struct sk_buff *skb) 478 { 479 u32 bucket = skb_get_hash_raw(skb) & (GRO_HASH_BUCKETS - 1); 480 struct list_head *head = &net_hotdata.offload_base; 481 struct gro_list *gro_list = &gro->hash[bucket]; 482 struct packet_offload *ptype; 483 __be16 type = skb->protocol; 484 struct sk_buff *pp = NULL; 485 enum gro_result ret; 486 int same_flow; 487 488 if (netif_elide_gro(skb->dev)) 489 goto normal; 490 491 gro_list_prepare(&gro_list->list, skb); 492 493 rcu_read_lock(); 494 list_for_each_entry_rcu(ptype, head, list) { 495 if (ptype->type == type && ptype->callbacks.gro_receive) 496 goto found_ptype; 497 } 498 rcu_read_unlock(); 499 goto normal; 500 501 found_ptype: 502 skb_set_network_header(skb, skb_gro_offset(skb)); 503 skb_reset_mac_len(skb); 504 BUILD_BUG_ON(sizeof_field(struct napi_gro_cb, zeroed) != sizeof(u32)); 505 BUILD_BUG_ON(!IS_ALIGNED(offsetof(struct napi_gro_cb, zeroed), 506 sizeof(u32))); /* Avoid slow unaligned acc */ 507 *(u32 *)&NAPI_GRO_CB(skb)->zeroed = 0; 508 NAPI_GRO_CB(skb)->flush = skb_has_frag_list(skb); 509 NAPI_GRO_CB(skb)->count = 1; 510 if (unlikely(skb_is_gso(skb))) { 511 NAPI_GRO_CB(skb)->count = skb_shinfo(skb)->gso_segs; 512 /* Only support TCP and non DODGY users. */ 513 if (!skb_is_gso_tcp(skb) || 514 (skb_shinfo(skb)->gso_type & SKB_GSO_DODGY)) 515 NAPI_GRO_CB(skb)->flush = 1; 516 } 517 518 /* Setup for GRO checksum validation */ 519 switch (skb->ip_summed) { 520 case CHECKSUM_COMPLETE: 521 NAPI_GRO_CB(skb)->csum = skb->csum; 522 NAPI_GRO_CB(skb)->csum_valid = 1; 523 break; 524 case CHECKSUM_UNNECESSARY: 525 NAPI_GRO_CB(skb)->csum_cnt = skb->csum_level + 1; 526 break; 527 } 528 529 pp = INDIRECT_CALL_INET(ptype->callbacks.gro_receive, 530 ipv6_gro_receive, inet_gro_receive, 531 &gro_list->list, skb); 532 533 rcu_read_unlock(); 534 535 if (PTR_ERR(pp) == -EINPROGRESS) { 536 ret = GRO_CONSUMED; 537 goto ok; 538 } 539 540 same_flow = NAPI_GRO_CB(skb)->same_flow; 541 ret = NAPI_GRO_CB(skb)->free ? GRO_MERGED_FREE : GRO_MERGED; 542 543 if (pp) { 544 skb_list_del_init(pp); 545 gro_complete(gro, pp); 546 gro_list->count--; 547 } 548 549 if (same_flow) 550 goto ok; 551 552 if (NAPI_GRO_CB(skb)->flush) 553 goto normal; 554 555 if (unlikely(gro_list->count >= MAX_GRO_SKBS)) 556 gro_flush_oldest(gro, &gro_list->list); 557 else 558 gro_list->count++; 559 560 /* Must be called before setting NAPI_GRO_CB(skb)->{age|last} */ 561 gro_try_pull_from_frag0(skb); 562 NAPI_GRO_CB(skb)->age = jiffies; 563 NAPI_GRO_CB(skb)->last = skb; 564 if (!skb_is_gso(skb)) 565 skb_shinfo(skb)->gso_size = skb_gro_len(skb); 566 list_add(&skb->list, &gro_list->list); 567 ret = GRO_HELD; 568 ok: 569 if (gro_list->count) { 570 if (!test_bit(bucket, &gro->bitmask)) 571 __set_bit(bucket, &gro->bitmask); 572 } else if (test_bit(bucket, &gro->bitmask)) { 573 __clear_bit(bucket, &gro->bitmask); 574 } 575 576 return ret; 577 578 normal: 579 ret = GRO_NORMAL; 580 gro_try_pull_from_frag0(skb); 581 goto ok; 582 } 583 584 struct packet_offload *gro_find_receive_by_type(__be16 type) 585 { 586 struct list_head *offload_head = &net_hotdata.offload_base; 587 struct packet_offload *ptype; 588 589 list_for_each_entry_rcu(ptype, offload_head, list) { 590 if (ptype->type != type || !ptype->callbacks.gro_receive) 591 continue; 592 return ptype; 593 } 594 return NULL; 595 } 596 EXPORT_SYMBOL(gro_find_receive_by_type); 597 598 struct packet_offload *gro_find_complete_by_type(__be16 type) 599 { 600 struct list_head *offload_head = &net_hotdata.offload_base; 601 struct packet_offload *ptype; 602 603 list_for_each_entry_rcu(ptype, offload_head, list) { 604 if (ptype->type != type || !ptype->callbacks.gro_complete) 605 continue; 606 return ptype; 607 } 608 return NULL; 609 } 610 EXPORT_SYMBOL(gro_find_complete_by_type); 611 612 static gro_result_t gro_skb_finish(struct gro_node *gro, struct sk_buff *skb, 613 gro_result_t ret) 614 { 615 switch (ret) { 616 case GRO_NORMAL: 617 gro_normal_one(gro, skb, 1); 618 break; 619 620 case GRO_MERGED_FREE: 621 if (NAPI_GRO_CB(skb)->free == NAPI_GRO_FREE_STOLEN_HEAD) 622 napi_skb_free_stolen_head(skb); 623 else if (skb->fclone != SKB_FCLONE_UNAVAILABLE) 624 __kfree_skb(skb); 625 else 626 __napi_kfree_skb(skb, SKB_CONSUMED); 627 break; 628 629 case GRO_HELD: 630 case GRO_MERGED: 631 case GRO_CONSUMED: 632 break; 633 } 634 635 return ret; 636 } 637 638 gro_result_t gro_receive_skb(struct gro_node *gro, struct sk_buff *skb) 639 { 640 gro_result_t ret; 641 642 __skb_mark_napi_id(skb, gro); 643 trace_napi_gro_receive_entry(skb); 644 645 skb_gro_reset_offset(skb, 0); 646 647 ret = gro_skb_finish(gro, skb, dev_gro_receive(gro, skb)); 648 trace_napi_gro_receive_exit(ret); 649 650 return ret; 651 } 652 EXPORT_SYMBOL(gro_receive_skb); 653 654 static void napi_reuse_skb(struct napi_struct *napi, struct sk_buff *skb) 655 { 656 struct skb_shared_info *shinfo; 657 658 if (unlikely(skb->pfmemalloc)) { 659 consume_skb(skb); 660 return; 661 } 662 __skb_pull(skb, skb_headlen(skb)); 663 /* restore the reserve we had after netdev_alloc_skb_ip_align() */ 664 skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN - skb_headroom(skb)); 665 __vlan_hwaccel_clear_tag(skb); 666 skb->dev = napi->dev; 667 skb->skb_iif = 0; 668 669 /* eth_type_trans() assumes pkt_type is PACKET_HOST */ 670 skb->pkt_type = PACKET_HOST; 671 672 skb->encapsulation = 0; 673 skb->ip_summed = CHECKSUM_NONE; 674 675 shinfo = skb_shinfo(skb); 676 shinfo->gso_type = 0; 677 shinfo->gso_size = 0; 678 shinfo->hwtstamps.hwtstamp = 0; 679 680 if (unlikely(skb->slow_gro)) { 681 skb_orphan(skb); 682 skb_ext_reset(skb); 683 nf_reset_ct(skb); 684 skb->slow_gro = 0; 685 } 686 687 napi->skb = skb; 688 } 689 690 struct sk_buff *napi_get_frags(struct napi_struct *napi) 691 { 692 struct sk_buff *skb = napi->skb; 693 694 if (!skb) { 695 skb = napi_alloc_skb(napi, GRO_MAX_HEAD); 696 if (skb) { 697 napi->skb = skb; 698 skb_mark_napi_id(skb, napi); 699 } 700 } 701 return skb; 702 } 703 EXPORT_SYMBOL(napi_get_frags); 704 705 static gro_result_t napi_frags_finish(struct napi_struct *napi, 706 struct sk_buff *skb, 707 gro_result_t ret) 708 { 709 switch (ret) { 710 case GRO_NORMAL: 711 case GRO_HELD: 712 __skb_push(skb, ETH_HLEN); 713 skb->protocol = eth_type_trans(skb, skb->dev); 714 if (ret == GRO_NORMAL) 715 gro_normal_one(&napi->gro, skb, 1); 716 break; 717 718 case GRO_MERGED_FREE: 719 if (NAPI_GRO_CB(skb)->free == NAPI_GRO_FREE_STOLEN_HEAD) 720 napi_skb_free_stolen_head(skb); 721 else 722 napi_reuse_skb(napi, skb); 723 break; 724 725 case GRO_MERGED: 726 case GRO_CONSUMED: 727 break; 728 } 729 730 return ret; 731 } 732 733 /* Upper GRO stack assumes network header starts at gro_offset=0 734 * Drivers could call both napi_gro_frags() and napi_gro_receive() 735 * We copy ethernet header into skb->data to have a common layout. 736 */ 737 static struct sk_buff *napi_frags_skb(struct napi_struct *napi) 738 { 739 struct sk_buff *skb = napi->skb; 740 const struct ethhdr *eth; 741 unsigned int hlen = sizeof(*eth); 742 743 napi->skb = NULL; 744 745 skb_reset_mac_header(skb); 746 skb_gro_reset_offset(skb, hlen); 747 748 if (unlikely(!skb_gro_may_pull(skb, hlen))) { 749 eth = skb_gro_header_slow(skb, hlen, 0); 750 if (unlikely(!eth)) { 751 net_warn_ratelimited("%s: dropping impossible skb from %s\n", 752 __func__, napi->dev->name); 753 napi_reuse_skb(napi, skb); 754 return NULL; 755 } 756 } else { 757 eth = (const struct ethhdr *)skb->data; 758 759 if (NAPI_GRO_CB(skb)->frag0 != skb->data) 760 gro_pull_from_frag0(skb, hlen); 761 762 NAPI_GRO_CB(skb)->frag0 += hlen; 763 NAPI_GRO_CB(skb)->frag0_len -= hlen; 764 } 765 __skb_pull(skb, hlen); 766 767 /* 768 * This works because the only protocols we care about don't require 769 * special handling. 770 * We'll fix it up properly in napi_frags_finish() 771 */ 772 skb->protocol = eth->h_proto; 773 774 return skb; 775 } 776 777 gro_result_t napi_gro_frags(struct napi_struct *napi) 778 { 779 gro_result_t ret; 780 struct sk_buff *skb = napi_frags_skb(napi); 781 782 trace_napi_gro_frags_entry(skb); 783 784 ret = napi_frags_finish(napi, skb, dev_gro_receive(&napi->gro, skb)); 785 trace_napi_gro_frags_exit(ret); 786 787 return ret; 788 } 789 EXPORT_SYMBOL(napi_gro_frags); 790 791 /* Compute the checksum from gro_offset and return the folded value 792 * after adding in any pseudo checksum. 793 */ 794 __sum16 __skb_gro_checksum_complete(struct sk_buff *skb) 795 { 796 __wsum wsum; 797 __sum16 sum; 798 799 wsum = skb_checksum(skb, skb_gro_offset(skb), skb_gro_len(skb), 0); 800 801 /* NAPI_GRO_CB(skb)->csum holds pseudo checksum */ 802 sum = csum_fold(csum_add(NAPI_GRO_CB(skb)->csum, wsum)); 803 /* See comments in __skb_checksum_complete(). */ 804 if (likely(!sum)) { 805 if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE) && 806 !skb->csum_complete_sw) 807 netdev_rx_csum_fault(skb->dev, skb); 808 } 809 810 NAPI_GRO_CB(skb)->csum = wsum; 811 NAPI_GRO_CB(skb)->csum_valid = 1; 812 813 return sum; 814 } 815 EXPORT_SYMBOL(__skb_gro_checksum_complete); 816 817 void gro_init(struct gro_node *gro) 818 { 819 for (u32 i = 0; i < GRO_HASH_BUCKETS; i++) { 820 INIT_LIST_HEAD(&gro->hash[i].list); 821 gro->hash[i].count = 0; 822 } 823 824 gro->bitmask = 0; 825 gro->cached_napi_id = 0; 826 827 INIT_LIST_HEAD(&gro->rx_list); 828 gro->rx_count = 0; 829 } 830 831 void gro_cleanup(struct gro_node *gro) 832 { 833 struct sk_buff *skb, *n; 834 835 for (u32 i = 0; i < GRO_HASH_BUCKETS; i++) { 836 list_for_each_entry_safe(skb, n, &gro->hash[i].list, list) 837 kfree_skb(skb); 838 839 gro->hash[i].count = 0; 840 } 841 842 gro->bitmask = 0; 843 gro->cached_napi_id = 0; 844 845 list_for_each_entry_safe(skb, n, &gro->rx_list, list) 846 kfree_skb(skb); 847 848 gro->rx_count = 0; 849 } 850