1// SPDX-License-Identifier: GPL-2.0-or-later 2/* 3 * IPV4 GSO/GRO offload support 4 * Linux INET implementation 5 * 6 * UDPv4 GSO support 7 */ 8 9#include <linux/skbuff.h> 10#include <net/udp.h> 11#include <net/protocol.h> 12#include <net/inet_common.h> 13 14static struct sk_buff *__skb_udp_tunnel_segment(struct sk_buff *skb, 15 netdev_features_t features, 16 struct sk_buff *(*gso_inner_segment)(struct sk_buff *skb, 17 netdev_features_t features), 18 __be16 new_protocol, bool is_ipv6) 19{ 20 int tnl_hlen = skb_inner_mac_header(skb) - skb_transport_header(skb); 21 bool remcsum, need_csum, offload_csum, gso_partial; 22 struct sk_buff *segs = ERR_PTR(-EINVAL); 23 struct udphdr *uh = udp_hdr(skb); 24 u16 mac_offset = skb->mac_header; 25 __be16 protocol = skb->protocol; 26 u16 mac_len = skb->mac_len; 27 int udp_offset, outer_hlen; 28 __wsum partial; 29 bool need_ipsec; 30 31 if (unlikely(!pskb_may_pull(skb, tnl_hlen))) 32 goto out; 33 34 /* Adjust partial header checksum to negate old length. 35 * We cannot rely on the value contained in uh->len as it is 36 * possible that the actual value exceeds the boundaries of the 37 * 16 bit length field due to the header being added outside of an 38 * IP or IPv6 frame that was already limited to 64K - 1. 39 */ 40 if (skb_shinfo(skb)->gso_type & SKB_GSO_PARTIAL) 41 partial = (__force __wsum)uh->len; 42 else 43 partial = (__force __wsum)htonl(skb->len); 44 partial = csum_sub(csum_unfold(uh->check), partial); 45 46 /* setup inner skb. */ 47 skb->encapsulation = 0; 48 SKB_GSO_CB(skb)->encap_level = 0; 49 __skb_pull(skb, tnl_hlen); 50 skb_reset_mac_header(skb); 51 skb_set_network_header(skb, skb_inner_network_offset(skb)); 52 skb->mac_len = skb_inner_network_offset(skb); 53 skb->protocol = new_protocol; 54 55 need_csum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL_CSUM); 56 skb->encap_hdr_csum = need_csum; 57 58 remcsum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TUNNEL_REMCSUM); 59 skb->remcsum_offload = remcsum; 60 61 need_ipsec = skb_dst(skb) && dst_xfrm(skb_dst(skb)); 62 /* Try to offload checksum if possible */ 63 offload_csum = !!(need_csum && 64 !need_ipsec && 65 (skb->dev->features & 66 (is_ipv6 ? (NETIF_F_HW_CSUM | NETIF_F_IPV6_CSUM) : 67 (NETIF_F_HW_CSUM | NETIF_F_IP_CSUM)))); 68 69 features &= skb->dev->hw_enc_features; 70 71 /* The only checksum offload we care about from here on out is the 72 * outer one so strip the existing checksum feature flags and 73 * instead set the flag based on our outer checksum offload value. 74 */ 75 if (remcsum) { 76 features &= ~NETIF_F_CSUM_MASK; 77 if (!need_csum || offload_csum) 78 features |= NETIF_F_HW_CSUM; 79 } 80 81 /* segment inner packet. */ 82 segs = gso_inner_segment(skb, features); 83 if (IS_ERR_OR_NULL(segs)) { 84 skb_gso_error_unwind(skb, protocol, tnl_hlen, mac_offset, 85 mac_len); 86 goto out; 87 } 88 89 gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL); 90 91 outer_hlen = skb_tnl_header_len(skb); 92 udp_offset = outer_hlen - tnl_hlen; 93 skb = segs; 94 do { 95 unsigned int len; 96 97 if (remcsum) 98 skb->ip_summed = CHECKSUM_NONE; 99 100 /* Set up inner headers if we are offloading inner checksum */ 101 if (skb->ip_summed == CHECKSUM_PARTIAL) { 102 skb_reset_inner_headers(skb); 103 skb->encapsulation = 1; 104 } 105 106 skb->mac_len = mac_len; 107 skb->protocol = protocol; 108 109 __skb_push(skb, outer_hlen); 110 skb_reset_mac_header(skb); 111 skb_set_network_header(skb, mac_len); 112 skb_set_transport_header(skb, udp_offset); 113 len = skb->len - udp_offset; 114 uh = udp_hdr(skb); 115 116 /* If we are only performing partial GSO the inner header 117 * will be using a length value equal to only one MSS sized 118 * segment instead of the entire frame. 119 */ 120 if (gso_partial && skb_is_gso(skb)) { 121 uh->len = htons(skb_shinfo(skb)->gso_size + 122 SKB_GSO_CB(skb)->data_offset + 123 skb->head - (unsigned char *)uh); 124 } else { 125 uh->len = htons(len); 126 } 127 128 if (!need_csum) 129 continue; 130 131 uh->check = ~csum_fold(csum_add(partial, 132 (__force __wsum)htonl(len))); 133 134 if (skb->encapsulation || !offload_csum) { 135 uh->check = gso_make_checksum(skb, ~uh->check); 136 if (uh->check == 0) 137 uh->check = CSUM_MANGLED_0; 138 } else { 139 skb->ip_summed = CHECKSUM_PARTIAL; 140 skb->csum_start = skb_transport_header(skb) - skb->head; 141 skb->csum_offset = offsetof(struct udphdr, check); 142 } 143 } while ((skb = skb->next)); 144out: 145 return segs; 146} 147 148struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb, 149 netdev_features_t features, 150 bool is_ipv6) 151{ 152 __be16 protocol = skb->protocol; 153 const struct net_offload **offloads; 154 const struct net_offload *ops; 155 struct sk_buff *segs = ERR_PTR(-EINVAL); 156 struct sk_buff *(*gso_inner_segment)(struct sk_buff *skb, 157 netdev_features_t features); 158 159 rcu_read_lock(); 160 161 switch (skb->inner_protocol_type) { 162 case ENCAP_TYPE_ETHER: 163 protocol = skb->inner_protocol; 164 gso_inner_segment = skb_mac_gso_segment; 165 break; 166 case ENCAP_TYPE_IPPROTO: 167 offloads = is_ipv6 ? inet6_offloads : inet_offloads; 168 ops = rcu_dereference(offloads[skb->inner_ipproto]); 169 if (!ops || !ops->callbacks.gso_segment) 170 goto out_unlock; 171 gso_inner_segment = ops->callbacks.gso_segment; 172 break; 173 default: 174 goto out_unlock; 175 } 176 177 segs = __skb_udp_tunnel_segment(skb, features, gso_inner_segment, 178 protocol, is_ipv6); 179 180out_unlock: 181 rcu_read_unlock(); 182 183 return segs; 184} 185EXPORT_SYMBOL(skb_udp_tunnel_segment); 186 187static void __udpv4_gso_segment_csum(struct sk_buff *seg, 188 __be32 *oldip, __be32 *newip, 189 __be16 *oldport, __be16 *newport) 190{ 191 struct udphdr *uh; 192 struct iphdr *iph; 193 194 if (*oldip == *newip && *oldport == *newport) 195 return; 196 197 uh = udp_hdr(seg); 198 iph = ip_hdr(seg); 199 200 if (uh->check) { 201 inet_proto_csum_replace4(&uh->check, seg, *oldip, *newip, 202 true); 203 inet_proto_csum_replace2(&uh->check, seg, *oldport, *newport, 204 false); 205 if (!uh->check) 206 uh->check = CSUM_MANGLED_0; 207 } 208 *oldport = *newport; 209 210 csum_replace4(&iph->check, *oldip, *newip); 211 *oldip = *newip; 212} 213 214static struct sk_buff *__udpv4_gso_segment_list_csum(struct sk_buff *segs) 215{ 216 struct sk_buff *seg; 217 struct udphdr *uh, *uh2; 218 struct iphdr *iph, *iph2; 219 220 seg = segs; 221 uh = udp_hdr(seg); 222 iph = ip_hdr(seg); 223 224 if ((udp_hdr(seg)->dest == udp_hdr(seg->next)->dest) && 225 (udp_hdr(seg)->source == udp_hdr(seg->next)->source) && 226 (ip_hdr(seg)->daddr == ip_hdr(seg->next)->daddr) && 227 (ip_hdr(seg)->saddr == ip_hdr(seg->next)->saddr)) 228 return segs; 229 230 while ((seg = seg->next)) { 231 uh2 = udp_hdr(seg); 232 iph2 = ip_hdr(seg); 233 234 __udpv4_gso_segment_csum(seg, 235 &iph2->saddr, &iph->saddr, 236 &uh2->source, &uh->source); 237 __udpv4_gso_segment_csum(seg, 238 &iph2->daddr, &iph->daddr, 239 &uh2->dest, &uh->dest); 240 } 241 242 return segs; 243} 244 245static struct sk_buff *__udp_gso_segment_list(struct sk_buff *skb, 246 netdev_features_t features, 247 bool is_ipv6) 248{ 249 unsigned int mss = skb_shinfo(skb)->gso_size; 250 251 skb = skb_segment_list(skb, features, skb_mac_header_len(skb)); 252 if (IS_ERR(skb)) 253 return skb; 254 255 udp_hdr(skb)->len = htons(sizeof(struct udphdr) + mss); 256 257 return is_ipv6 ? skb : __udpv4_gso_segment_list_csum(skb); 258} 259 260struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb, 261 netdev_features_t features, bool is_ipv6) 262{ 263 struct sock *sk = gso_skb->sk; 264 unsigned int sum_truesize = 0; 265 struct sk_buff *segs, *seg; 266 struct udphdr *uh; 267 unsigned int mss; 268 bool copy_dtor; 269 __sum16 check; 270 __be16 newlen; 271 272 if (skb_shinfo(gso_skb)->gso_type & SKB_GSO_FRAGLIST) 273 return __udp_gso_segment_list(gso_skb, features, is_ipv6); 274 275 mss = skb_shinfo(gso_skb)->gso_size; 276 if (gso_skb->len <= sizeof(*uh) + mss) 277 return ERR_PTR(-EINVAL); 278 279 skb_pull(gso_skb, sizeof(*uh)); 280 281 /* clear destructor to avoid skb_segment assigning it to tail */ 282 copy_dtor = gso_skb->destructor == sock_wfree; 283 if (copy_dtor) 284 gso_skb->destructor = NULL; 285 286 segs = skb_segment(gso_skb, features); 287 if (IS_ERR_OR_NULL(segs)) { 288 if (copy_dtor) 289 gso_skb->destructor = sock_wfree; 290 return segs; 291 } 292 293 /* GSO partial and frag_list segmentation only requires splitting 294 * the frame into an MSS multiple and possibly a remainder, both 295 * cases return a GSO skb. So update the mss now. 296 */ 297 if (skb_is_gso(segs)) 298 mss *= skb_shinfo(segs)->gso_segs; 299 300 seg = segs; 301 uh = udp_hdr(seg); 302 303 /* preserve TX timestamp flags and TS key for first segment */ 304 skb_shinfo(seg)->tskey = skb_shinfo(gso_skb)->tskey; 305 skb_shinfo(seg)->tx_flags |= 306 (skb_shinfo(gso_skb)->tx_flags & SKBTX_ANY_TSTAMP); 307 308 /* compute checksum adjustment based on old length versus new */ 309 newlen = htons(sizeof(*uh) + mss); 310 check = csum16_add(csum16_sub(uh->check, uh->len), newlen); 311 312 for (;;) { 313 if (copy_dtor) { 314 seg->destructor = sock_wfree; 315 seg->sk = sk; 316 sum_truesize += seg->truesize; 317 } 318 319 if (!seg->next) 320 break; 321 322 uh->len = newlen; 323 uh->check = check; 324 325 if (seg->ip_summed == CHECKSUM_PARTIAL) 326 gso_reset_checksum(seg, ~check); 327 else 328 uh->check = gso_make_checksum(seg, ~check) ? : 329 CSUM_MANGLED_0; 330 331 seg = seg->next; 332 uh = udp_hdr(seg); 333 } 334 335 /* last packet can be partial gso_size, account for that in checksum */ 336 newlen = htons(skb_tail_pointer(seg) - skb_transport_header(seg) + 337 seg->data_len); 338 check = csum16_add(csum16_sub(uh->check, uh->len), newlen); 339 340 uh->len = newlen; 341 uh->check = check; 342 343 if (seg->ip_summed == CHECKSUM_PARTIAL) 344 gso_reset_checksum(seg, ~check); 345 else 346 uh->check = gso_make_checksum(seg, ~check) ? : CSUM_MANGLED_0; 347 348 /* update refcount for the packet */ 349 if (copy_dtor) { 350 int delta = sum_truesize - gso_skb->truesize; 351 352 /* In some pathological cases, delta can be negative. 353 * We need to either use refcount_add() or refcount_sub_and_test() 354 */ 355 if (likely(delta >= 0)) 356 refcount_add(delta, &sk->sk_wmem_alloc); 357 else 358 WARN_ON_ONCE(refcount_sub_and_test(-delta, &sk->sk_wmem_alloc)); 359 } 360 return segs; 361} 362EXPORT_SYMBOL_GPL(__udp_gso_segment); 363 364static struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb, 365 netdev_features_t features) 366{ 367 struct sk_buff *segs = ERR_PTR(-EINVAL); 368 unsigned int mss; 369 __wsum csum; 370 struct udphdr *uh; 371 struct iphdr *iph; 372 373 if (skb->encapsulation && 374 (skb_shinfo(skb)->gso_type & 375 (SKB_GSO_UDP_TUNNEL|SKB_GSO_UDP_TUNNEL_CSUM))) { 376 segs = skb_udp_tunnel_segment(skb, features, false); 377 goto out; 378 } 379 380 if (!(skb_shinfo(skb)->gso_type & (SKB_GSO_UDP | SKB_GSO_UDP_L4))) 381 goto out; 382 383 if (!pskb_may_pull(skb, sizeof(struct udphdr))) 384 goto out; 385 386 if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) 387 return __udp_gso_segment(skb, features, false); 388 389 mss = skb_shinfo(skb)->gso_size; 390 if (unlikely(skb->len <= mss)) 391 goto out; 392 393 /* Do software UFO. Complete and fill in the UDP checksum as 394 * HW cannot do checksum of UDP packets sent as multiple 395 * IP fragments. 396 */ 397 398 uh = udp_hdr(skb); 399 iph = ip_hdr(skb); 400 401 uh->check = 0; 402 csum = skb_checksum(skb, 0, skb->len, 0); 403 uh->check = udp_v4_check(skb->len, iph->saddr, iph->daddr, csum); 404 if (uh->check == 0) 405 uh->check = CSUM_MANGLED_0; 406 407 skb->ip_summed = CHECKSUM_UNNECESSARY; 408 409 /* If there is no outer header we can fake a checksum offload 410 * due to the fact that we have already done the checksum in 411 * software prior to segmenting the frame. 412 */ 413 if (!skb->encap_hdr_csum) 414 features |= NETIF_F_HW_CSUM; 415 416 /* Fragment the skb. IP headers of the fragments are updated in 417 * inet_gso_segment() 418 */ 419 segs = skb_segment(skb, features); 420out: 421 return segs; 422} 423 424#define UDP_GRO_CNT_MAX 64 425static struct sk_buff *udp_gro_receive_segment(struct list_head *head, 426 struct sk_buff *skb) 427{ 428 struct udphdr *uh = udp_gro_udphdr(skb); 429 struct sk_buff *pp = NULL; 430 struct udphdr *uh2; 431 struct sk_buff *p; 432 unsigned int ulen; 433 int ret = 0; 434 435 /* requires non zero csum, for symmetry with GSO */ 436 if (!uh->check) { 437 NAPI_GRO_CB(skb)->flush = 1; 438 return NULL; 439 } 440 441 /* Do not deal with padded or malicious packets, sorry ! */ 442 ulen = ntohs(uh->len); 443 if (ulen <= sizeof(*uh) || ulen != skb_gro_len(skb)) { 444 NAPI_GRO_CB(skb)->flush = 1; 445 return NULL; 446 } 447 /* pull encapsulating udp header */ 448 skb_gro_pull(skb, sizeof(struct udphdr)); 449 450 list_for_each_entry(p, head, list) { 451 if (!NAPI_GRO_CB(p)->same_flow) 452 continue; 453 454 uh2 = udp_hdr(p); 455 456 /* Match ports only, as csum is always non zero */ 457 if ((*(u32 *)&uh->source != *(u32 *)&uh2->source)) { 458 NAPI_GRO_CB(p)->same_flow = 0; 459 continue; 460 } 461 462 if (NAPI_GRO_CB(skb)->is_flist != NAPI_GRO_CB(p)->is_flist) { 463 NAPI_GRO_CB(skb)->flush = 1; 464 return p; 465 } 466 467 /* Terminate the flow on len mismatch or if it grow "too much". 468 * Under small packet flood GRO count could elsewhere grow a lot 469 * leading to excessive truesize values. 470 * On len mismatch merge the first packet shorter than gso_size, 471 * otherwise complete the GRO packet. 472 */ 473 if (ulen > ntohs(uh2->len)) { 474 pp = p; 475 } else { 476 if (NAPI_GRO_CB(skb)->is_flist) { 477 if (!pskb_may_pull(skb, skb_gro_offset(skb))) { 478 NAPI_GRO_CB(skb)->flush = 1; 479 return NULL; 480 } 481 if ((skb->ip_summed != p->ip_summed) || 482 (skb->csum_level != p->csum_level)) { 483 NAPI_GRO_CB(skb)->flush = 1; 484 return NULL; 485 } 486 ret = skb_gro_receive_list(p, skb); 487 } else { 488 skb_gro_postpull_rcsum(skb, uh, 489 sizeof(struct udphdr)); 490 491 ret = skb_gro_receive(p, skb); 492 } 493 } 494 495 if (ret || ulen != ntohs(uh2->len) || 496 NAPI_GRO_CB(p)->count >= UDP_GRO_CNT_MAX) 497 pp = p; 498 499 return pp; 500 } 501 502 /* mismatch, but we never need to flush */ 503 return NULL; 504} 505 506struct sk_buff *udp_gro_receive(struct list_head *head, struct sk_buff *skb, 507 struct udphdr *uh, struct sock *sk) 508{ 509 struct sk_buff *pp = NULL; 510 struct sk_buff *p; 511 struct udphdr *uh2; 512 unsigned int off = skb_gro_offset(skb); 513 int flush = 1; 514 515 /* We can do L4 aggregation only if the packet can't land in a tunnel 516 * otherwise we could corrupt the inner stream. Detecting such packets 517 * cannot be foolproof and the aggregation might still happen in some 518 * cases. Such packets should be caught in udp_unexpected_gso later. 519 */ 520 NAPI_GRO_CB(skb)->is_flist = 0; 521 if (skb->dev->features & NETIF_F_GRO_FRAGLIST) 522 NAPI_GRO_CB(skb)->is_flist = sk ? !udp_sk(sk)->gro_enabled: 1; 523 524 if ((sk && udp_sk(sk)->gro_enabled) || NAPI_GRO_CB(skb)->is_flist) { 525 pp = call_gro_receive(udp_gro_receive_segment, head, skb); 526 return pp; 527 } 528 529 if (!sk || NAPI_GRO_CB(skb)->encap_mark || 530 (uh->check && skb->ip_summed != CHECKSUM_PARTIAL && 531 NAPI_GRO_CB(skb)->csum_cnt == 0 && 532 !NAPI_GRO_CB(skb)->csum_valid) || 533 !udp_sk(sk)->gro_receive) 534 goto out; 535 536 /* mark that this skb passed once through the tunnel gro layer */ 537 NAPI_GRO_CB(skb)->encap_mark = 1; 538 539 flush = 0; 540 541 list_for_each_entry(p, head, list) { 542 if (!NAPI_GRO_CB(p)->same_flow) 543 continue; 544 545 uh2 = (struct udphdr *)(p->data + off); 546 547 /* Match ports and either checksums are either both zero 548 * or nonzero. 549 */ 550 if ((*(u32 *)&uh->source != *(u32 *)&uh2->source) || 551 (!uh->check ^ !uh2->check)) { 552 NAPI_GRO_CB(p)->same_flow = 0; 553 continue; 554 } 555 } 556 557 skb_gro_pull(skb, sizeof(struct udphdr)); /* pull encapsulating udp header */ 558 skb_gro_postpull_rcsum(skb, uh, sizeof(struct udphdr)); 559 pp = call_gro_receive_sk(udp_sk(sk)->gro_receive, sk, head, skb); 560 561out: 562 skb_gro_flush_final(skb, pp, flush); 563 return pp; 564} 565EXPORT_SYMBOL(udp_gro_receive); 566 567static struct sock *udp4_gro_lookup_skb(struct sk_buff *skb, __be16 sport, 568 __be16 dport) 569{ 570 const struct iphdr *iph = skb_gro_network_header(skb); 571 572 return __udp4_lib_lookup(dev_net(skb->dev), iph->saddr, sport, 573 iph->daddr, dport, inet_iif(skb), 574 inet_sdif(skb), &udp_table, NULL); 575} 576 577INDIRECT_CALLABLE_SCOPE 578struct sk_buff *udp4_gro_receive(struct list_head *head, struct sk_buff *skb) 579{ 580 struct udphdr *uh = udp_gro_udphdr(skb); 581 struct sock *sk = NULL; 582 struct sk_buff *pp; 583 584 if (unlikely(!uh)) 585 goto flush; 586 587 /* Don't bother verifying checksum if we're going to flush anyway. */ 588 if (NAPI_GRO_CB(skb)->flush) 589 goto skip; 590 591 if (skb_gro_checksum_validate_zero_check(skb, IPPROTO_UDP, uh->check, 592 inet_gro_compute_pseudo)) 593 goto flush; 594 else if (uh->check) 595 skb_gro_checksum_try_convert(skb, IPPROTO_UDP, 596 inet_gro_compute_pseudo); 597skip: 598 NAPI_GRO_CB(skb)->is_ipv6 = 0; 599 rcu_read_lock(); 600 601 if (static_branch_unlikely(&udp_encap_needed_key)) 602 sk = udp4_gro_lookup_skb(skb, uh->source, uh->dest); 603 604 pp = udp_gro_receive(head, skb, uh, sk); 605 rcu_read_unlock(); 606 return pp; 607 608flush: 609 NAPI_GRO_CB(skb)->flush = 1; 610 return NULL; 611} 612 613static int udp_gro_complete_segment(struct sk_buff *skb) 614{ 615 struct udphdr *uh = udp_hdr(skb); 616 617 skb->csum_start = (unsigned char *)uh - skb->head; 618 skb->csum_offset = offsetof(struct udphdr, check); 619 skb->ip_summed = CHECKSUM_PARTIAL; 620 621 skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count; 622 skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_L4; 623 624 if (skb->encapsulation) 625 skb->inner_transport_header = skb->transport_header; 626 627 return 0; 628} 629 630int udp_gro_complete(struct sk_buff *skb, int nhoff, 631 udp_lookup_t lookup) 632{ 633 __be16 newlen = htons(skb->len - nhoff); 634 struct udphdr *uh = (struct udphdr *)(skb->data + nhoff); 635 int err = -ENOSYS; 636 struct sock *sk; 637 638 uh->len = newlen; 639 640 rcu_read_lock(); 641 sk = INDIRECT_CALL_INET(lookup, udp6_lib_lookup_skb, 642 udp4_lib_lookup_skb, skb, uh->source, uh->dest); 643 if (sk && udp_sk(sk)->gro_complete) { 644 skb_shinfo(skb)->gso_type = uh->check ? SKB_GSO_UDP_TUNNEL_CSUM 645 : SKB_GSO_UDP_TUNNEL; 646 647 /* Set encapsulation before calling into inner gro_complete() 648 * functions to make them set up the inner offsets. 649 */ 650 skb->encapsulation = 1; 651 err = udp_sk(sk)->gro_complete(sk, skb, 652 nhoff + sizeof(struct udphdr)); 653 } else { 654 err = udp_gro_complete_segment(skb); 655 } 656 rcu_read_unlock(); 657 658 if (skb->remcsum_offload) 659 skb_shinfo(skb)->gso_type |= SKB_GSO_TUNNEL_REMCSUM; 660 661 return err; 662} 663EXPORT_SYMBOL(udp_gro_complete); 664 665INDIRECT_CALLABLE_SCOPE int udp4_gro_complete(struct sk_buff *skb, int nhoff) 666{ 667 const struct iphdr *iph = ip_hdr(skb); 668 struct udphdr *uh = (struct udphdr *)(skb->data + nhoff); 669 670 if (NAPI_GRO_CB(skb)->is_flist) { 671 uh->len = htons(skb->len - nhoff); 672 673 skb_shinfo(skb)->gso_type |= (SKB_GSO_FRAGLIST|SKB_GSO_UDP_L4); 674 skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count; 675 676 if (skb->ip_summed == CHECKSUM_UNNECESSARY) { 677 if (skb->csum_level < SKB_MAX_CSUM_LEVEL) 678 skb->csum_level++; 679 } else { 680 skb->ip_summed = CHECKSUM_UNNECESSARY; 681 skb->csum_level = 0; 682 } 683 684 return 0; 685 } 686 687 if (uh->check) 688 uh->check = ~udp_v4_check(skb->len - nhoff, iph->saddr, 689 iph->daddr, 0); 690 691 return udp_gro_complete(skb, nhoff, udp4_lib_lookup_skb); 692} 693 694static const struct net_offload udpv4_offload = { 695 .callbacks = { 696 .gso_segment = udp4_ufo_fragment, 697 .gro_receive = udp4_gro_receive, 698 .gro_complete = udp4_gro_complete, 699 }, 700}; 701 702int __init udpv4_offload_init(void) 703{ 704 return inet_add_offload(&udpv4_offload, IPPROTO_UDP); 705} 706