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/gro.h> 11 #include <net/udp.h> 12 #include <net/protocol.h> 13 #include <net/inet_common.h> 14 15 static struct sk_buff *__skb_udp_tunnel_segment(struct sk_buff *skb, 16 netdev_features_t features, 17 struct sk_buff *(*gso_inner_segment)(struct sk_buff *skb, 18 netdev_features_t features), 19 __be16 new_protocol, bool is_ipv6) 20 { 21 int tnl_hlen = skb_inner_mac_header(skb) - skb_transport_header(skb); 22 bool remcsum, need_csum, offload_csum, gso_partial; 23 struct sk_buff *segs = ERR_PTR(-EINVAL); 24 struct udphdr *uh = udp_hdr(skb); 25 u16 mac_offset = skb->mac_header; 26 __be16 protocol = skb->protocol; 27 u16 mac_len = skb->mac_len; 28 int udp_offset, outer_hlen; 29 __wsum partial; 30 bool need_ipsec; 31 32 if (unlikely(!pskb_may_pull(skb, tnl_hlen))) 33 goto out; 34 35 /* Adjust partial header checksum to negate old length. 36 * We cannot rely on the value contained in uh->len as it is 37 * possible that the actual value exceeds the boundaries of the 38 * 16 bit length field due to the header being added outside of an 39 * IP or IPv6 frame that was already limited to 64K - 1. 40 */ 41 if (skb_shinfo(skb)->gso_type & SKB_GSO_PARTIAL) 42 partial = (__force __wsum)uh->len; 43 else 44 partial = (__force __wsum)htonl(skb->len); 45 partial = csum_sub(csum_unfold(uh->check), partial); 46 47 /* setup inner skb. */ 48 skb->encapsulation = 0; 49 SKB_GSO_CB(skb)->encap_level = 0; 50 __skb_pull(skb, tnl_hlen); 51 skb_reset_mac_header(skb); 52 skb_set_network_header(skb, skb_inner_network_offset(skb)); 53 skb_set_transport_header(skb, skb_inner_transport_offset(skb)); 54 skb->mac_len = skb_inner_network_offset(skb); 55 skb->protocol = new_protocol; 56 57 need_csum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL_CSUM); 58 skb->encap_hdr_csum = need_csum; 59 60 remcsum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TUNNEL_REMCSUM); 61 skb->remcsum_offload = remcsum; 62 63 need_ipsec = skb_dst(skb) && dst_xfrm(skb_dst(skb)); 64 /* Try to offload checksum if possible */ 65 offload_csum = !!(need_csum && 66 !need_ipsec && 67 (skb->dev->features & 68 (is_ipv6 ? (NETIF_F_HW_CSUM | NETIF_F_IPV6_CSUM) : 69 (NETIF_F_HW_CSUM | NETIF_F_IP_CSUM)))); 70 71 features &= skb->dev->hw_enc_features; 72 if (need_csum) 73 features &= ~NETIF_F_SCTP_CRC; 74 75 /* The only checksum offload we care about from here on out is the 76 * outer one so strip the existing checksum feature flags and 77 * instead set the flag based on our outer checksum offload value. 78 */ 79 if (remcsum) { 80 features &= ~NETIF_F_CSUM_MASK; 81 if (!need_csum || offload_csum) 82 features |= NETIF_F_HW_CSUM; 83 } 84 85 /* segment inner packet. */ 86 segs = gso_inner_segment(skb, features); 87 if (IS_ERR_OR_NULL(segs)) { 88 skb_gso_error_unwind(skb, protocol, tnl_hlen, mac_offset, 89 mac_len); 90 goto out; 91 } 92 93 gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL); 94 95 outer_hlen = skb_tnl_header_len(skb); 96 udp_offset = outer_hlen - tnl_hlen; 97 skb = segs; 98 do { 99 unsigned int len; 100 101 if (remcsum) 102 skb->ip_summed = CHECKSUM_NONE; 103 104 /* Set up inner headers if we are offloading inner checksum */ 105 if (skb->ip_summed == CHECKSUM_PARTIAL) { 106 skb_reset_inner_headers(skb); 107 skb->encapsulation = 1; 108 } 109 110 skb->mac_len = mac_len; 111 skb->protocol = protocol; 112 113 __skb_push(skb, outer_hlen); 114 skb_reset_mac_header(skb); 115 skb_set_network_header(skb, mac_len); 116 skb_set_transport_header(skb, udp_offset); 117 len = skb->len - udp_offset; 118 uh = udp_hdr(skb); 119 120 /* If we are only performing partial GSO the inner header 121 * will be using a length value equal to only one MSS sized 122 * segment instead of the entire frame. 123 */ 124 if (gso_partial && skb_is_gso(skb)) { 125 uh->len = htons(skb_shinfo(skb)->gso_size + 126 SKB_GSO_CB(skb)->data_offset + 127 skb->head - (unsigned char *)uh); 128 } else { 129 uh->len = htons(len); 130 } 131 132 if (!need_csum) 133 continue; 134 135 uh->check = ~csum_fold(csum_add(partial, 136 (__force __wsum)htonl(len))); 137 138 if (skb->encapsulation || !offload_csum) { 139 uh->check = gso_make_checksum(skb, ~uh->check); 140 if (uh->check == 0) 141 uh->check = CSUM_MANGLED_0; 142 } else { 143 skb->ip_summed = CHECKSUM_PARTIAL; 144 skb->csum_start = skb_transport_header(skb) - skb->head; 145 skb->csum_offset = offsetof(struct udphdr, check); 146 } 147 } while ((skb = skb->next)); 148 out: 149 return segs; 150 } 151 152 struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb, 153 netdev_features_t features, 154 bool is_ipv6) 155 { 156 const struct net_offload __rcu **offloads; 157 __be16 protocol = skb->protocol; 158 const struct net_offload *ops; 159 struct sk_buff *segs = ERR_PTR(-EINVAL); 160 struct sk_buff *(*gso_inner_segment)(struct sk_buff *skb, 161 netdev_features_t features); 162 163 rcu_read_lock(); 164 165 switch (skb->inner_protocol_type) { 166 case ENCAP_TYPE_ETHER: 167 protocol = skb->inner_protocol; 168 gso_inner_segment = skb_mac_gso_segment; 169 break; 170 case ENCAP_TYPE_IPPROTO: 171 offloads = is_ipv6 ? inet6_offloads : inet_offloads; 172 ops = rcu_dereference(offloads[skb->inner_ipproto]); 173 if (!ops || !ops->callbacks.gso_segment) 174 goto out_unlock; 175 gso_inner_segment = ops->callbacks.gso_segment; 176 break; 177 default: 178 goto out_unlock; 179 } 180 181 segs = __skb_udp_tunnel_segment(skb, features, gso_inner_segment, 182 protocol, is_ipv6); 183 184 out_unlock: 185 rcu_read_unlock(); 186 187 return segs; 188 } 189 EXPORT_SYMBOL(skb_udp_tunnel_segment); 190 191 static void __udpv4_gso_segment_csum(struct sk_buff *seg, 192 __be32 *oldip, __be32 *newip, 193 __be16 *oldport, __be16 *newport) 194 { 195 struct udphdr *uh; 196 struct iphdr *iph; 197 198 if (*oldip == *newip && *oldport == *newport) 199 return; 200 201 uh = udp_hdr(seg); 202 iph = ip_hdr(seg); 203 204 if (uh->check) { 205 inet_proto_csum_replace4(&uh->check, seg, *oldip, *newip, 206 true); 207 inet_proto_csum_replace2(&uh->check, seg, *oldport, *newport, 208 false); 209 if (!uh->check) 210 uh->check = CSUM_MANGLED_0; 211 } 212 *oldport = *newport; 213 214 csum_replace4(&iph->check, *oldip, *newip); 215 *oldip = *newip; 216 } 217 218 static struct sk_buff *__udpv4_gso_segment_list_csum(struct sk_buff *segs) 219 { 220 struct sk_buff *seg; 221 struct udphdr *uh, *uh2; 222 struct iphdr *iph, *iph2; 223 224 seg = segs; 225 uh = udp_hdr(seg); 226 iph = ip_hdr(seg); 227 228 if ((udp_hdr(seg)->dest == udp_hdr(seg->next)->dest) && 229 (udp_hdr(seg)->source == udp_hdr(seg->next)->source) && 230 (ip_hdr(seg)->daddr == ip_hdr(seg->next)->daddr) && 231 (ip_hdr(seg)->saddr == ip_hdr(seg->next)->saddr)) 232 return segs; 233 234 while ((seg = seg->next)) { 235 uh2 = udp_hdr(seg); 236 iph2 = ip_hdr(seg); 237 238 __udpv4_gso_segment_csum(seg, 239 &iph2->saddr, &iph->saddr, 240 &uh2->source, &uh->source); 241 __udpv4_gso_segment_csum(seg, 242 &iph2->daddr, &iph->daddr, 243 &uh2->dest, &uh->dest); 244 } 245 246 return segs; 247 } 248 249 static struct sk_buff *__udp_gso_segment_list(struct sk_buff *skb, 250 netdev_features_t features, 251 bool is_ipv6) 252 { 253 unsigned int mss = skb_shinfo(skb)->gso_size; 254 255 skb = skb_segment_list(skb, features, skb_mac_header_len(skb)); 256 if (IS_ERR(skb)) 257 return skb; 258 259 udp_hdr(skb)->len = htons(sizeof(struct udphdr) + mss); 260 261 return is_ipv6 ? skb : __udpv4_gso_segment_list_csum(skb); 262 } 263 264 struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb, 265 netdev_features_t features, bool is_ipv6) 266 { 267 struct sock *sk = gso_skb->sk; 268 unsigned int sum_truesize = 0; 269 struct sk_buff *segs, *seg; 270 struct udphdr *uh; 271 unsigned int mss; 272 bool copy_dtor; 273 __sum16 check; 274 __be16 newlen; 275 276 if (skb_shinfo(gso_skb)->gso_type & SKB_GSO_FRAGLIST) 277 return __udp_gso_segment_list(gso_skb, features, is_ipv6); 278 279 mss = skb_shinfo(gso_skb)->gso_size; 280 if (gso_skb->len <= sizeof(*uh) + mss) 281 return ERR_PTR(-EINVAL); 282 283 skb_pull(gso_skb, sizeof(*uh)); 284 285 /* clear destructor to avoid skb_segment assigning it to tail */ 286 copy_dtor = gso_skb->destructor == sock_wfree; 287 if (copy_dtor) 288 gso_skb->destructor = NULL; 289 290 segs = skb_segment(gso_skb, features); 291 if (IS_ERR_OR_NULL(segs)) { 292 if (copy_dtor) 293 gso_skb->destructor = sock_wfree; 294 return segs; 295 } 296 297 /* GSO partial and frag_list segmentation only requires splitting 298 * the frame into an MSS multiple and possibly a remainder, both 299 * cases return a GSO skb. So update the mss now. 300 */ 301 if (skb_is_gso(segs)) 302 mss *= skb_shinfo(segs)->gso_segs; 303 304 seg = segs; 305 uh = udp_hdr(seg); 306 307 /* preserve TX timestamp flags and TS key for first segment */ 308 skb_shinfo(seg)->tskey = skb_shinfo(gso_skb)->tskey; 309 skb_shinfo(seg)->tx_flags |= 310 (skb_shinfo(gso_skb)->tx_flags & SKBTX_ANY_TSTAMP); 311 312 /* compute checksum adjustment based on old length versus new */ 313 newlen = htons(sizeof(*uh) + mss); 314 check = csum16_add(csum16_sub(uh->check, uh->len), newlen); 315 316 for (;;) { 317 if (copy_dtor) { 318 seg->destructor = sock_wfree; 319 seg->sk = sk; 320 sum_truesize += seg->truesize; 321 } 322 323 if (!seg->next) 324 break; 325 326 uh->len = newlen; 327 uh->check = check; 328 329 if (seg->ip_summed == CHECKSUM_PARTIAL) 330 gso_reset_checksum(seg, ~check); 331 else 332 uh->check = gso_make_checksum(seg, ~check) ? : 333 CSUM_MANGLED_0; 334 335 seg = seg->next; 336 uh = udp_hdr(seg); 337 } 338 339 /* last packet can be partial gso_size, account for that in checksum */ 340 newlen = htons(skb_tail_pointer(seg) - skb_transport_header(seg) + 341 seg->data_len); 342 check = csum16_add(csum16_sub(uh->check, uh->len), newlen); 343 344 uh->len = newlen; 345 uh->check = check; 346 347 if (seg->ip_summed == CHECKSUM_PARTIAL) 348 gso_reset_checksum(seg, ~check); 349 else 350 uh->check = gso_make_checksum(seg, ~check) ? : CSUM_MANGLED_0; 351 352 /* update refcount for the packet */ 353 if (copy_dtor) { 354 int delta = sum_truesize - gso_skb->truesize; 355 356 /* In some pathological cases, delta can be negative. 357 * We need to either use refcount_add() or refcount_sub_and_test() 358 */ 359 if (likely(delta >= 0)) 360 refcount_add(delta, &sk->sk_wmem_alloc); 361 else 362 WARN_ON_ONCE(refcount_sub_and_test(-delta, &sk->sk_wmem_alloc)); 363 } 364 return segs; 365 } 366 EXPORT_SYMBOL_GPL(__udp_gso_segment); 367 368 static struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb, 369 netdev_features_t features) 370 { 371 struct sk_buff *segs = ERR_PTR(-EINVAL); 372 unsigned int mss; 373 __wsum csum; 374 struct udphdr *uh; 375 struct iphdr *iph; 376 377 if (skb->encapsulation && 378 (skb_shinfo(skb)->gso_type & 379 (SKB_GSO_UDP_TUNNEL|SKB_GSO_UDP_TUNNEL_CSUM))) { 380 segs = skb_udp_tunnel_segment(skb, features, false); 381 goto out; 382 } 383 384 if (!(skb_shinfo(skb)->gso_type & (SKB_GSO_UDP | SKB_GSO_UDP_L4))) 385 goto out; 386 387 if (!pskb_may_pull(skb, sizeof(struct udphdr))) 388 goto out; 389 390 if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) 391 return __udp_gso_segment(skb, features, false); 392 393 mss = skb_shinfo(skb)->gso_size; 394 if (unlikely(skb->len <= mss)) 395 goto out; 396 397 /* Do software UFO. Complete and fill in the UDP checksum as 398 * HW cannot do checksum of UDP packets sent as multiple 399 * IP fragments. 400 */ 401 402 uh = udp_hdr(skb); 403 iph = ip_hdr(skb); 404 405 uh->check = 0; 406 csum = skb_checksum(skb, 0, skb->len, 0); 407 uh->check = udp_v4_check(skb->len, iph->saddr, iph->daddr, csum); 408 if (uh->check == 0) 409 uh->check = CSUM_MANGLED_0; 410 411 skb->ip_summed = CHECKSUM_UNNECESSARY; 412 413 /* If there is no outer header we can fake a checksum offload 414 * due to the fact that we have already done the checksum in 415 * software prior to segmenting the frame. 416 */ 417 if (!skb->encap_hdr_csum) 418 features |= NETIF_F_HW_CSUM; 419 420 /* Fragment the skb. IP headers of the fragments are updated in 421 * inet_gso_segment() 422 */ 423 segs = skb_segment(skb, features); 424 out: 425 return segs; 426 } 427 428 static int skb_gro_receive_list(struct sk_buff *p, struct sk_buff *skb) 429 { 430 if (unlikely(p->len + skb->len >= 65536)) 431 return -E2BIG; 432 433 if (NAPI_GRO_CB(p)->last == p) 434 skb_shinfo(p)->frag_list = skb; 435 else 436 NAPI_GRO_CB(p)->last->next = skb; 437 438 skb_pull(skb, skb_gro_offset(skb)); 439 440 NAPI_GRO_CB(p)->last = skb; 441 NAPI_GRO_CB(p)->count++; 442 p->data_len += skb->len; 443 444 /* sk owenrship - if any - completely transferred to the aggregated packet */ 445 skb->destructor = NULL; 446 p->truesize += skb->truesize; 447 p->len += skb->len; 448 449 NAPI_GRO_CB(skb)->same_flow = 1; 450 451 return 0; 452 } 453 454 455 #define UDP_GRO_CNT_MAX 64 456 static struct sk_buff *udp_gro_receive_segment(struct list_head *head, 457 struct sk_buff *skb) 458 { 459 struct udphdr *uh = udp_gro_udphdr(skb); 460 struct sk_buff *pp = NULL; 461 struct udphdr *uh2; 462 struct sk_buff *p; 463 unsigned int ulen; 464 int ret = 0; 465 466 /* requires non zero csum, for symmetry with GSO */ 467 if (!uh->check) { 468 NAPI_GRO_CB(skb)->flush = 1; 469 return NULL; 470 } 471 472 /* Do not deal with padded or malicious packets, sorry ! */ 473 ulen = ntohs(uh->len); 474 if (ulen <= sizeof(*uh) || ulen != skb_gro_len(skb)) { 475 NAPI_GRO_CB(skb)->flush = 1; 476 return NULL; 477 } 478 /* pull encapsulating udp header */ 479 skb_gro_pull(skb, sizeof(struct udphdr)); 480 481 list_for_each_entry(p, head, list) { 482 if (!NAPI_GRO_CB(p)->same_flow) 483 continue; 484 485 uh2 = udp_hdr(p); 486 487 /* Match ports only, as csum is always non zero */ 488 if ((*(u32 *)&uh->source != *(u32 *)&uh2->source)) { 489 NAPI_GRO_CB(p)->same_flow = 0; 490 continue; 491 } 492 493 if (NAPI_GRO_CB(skb)->is_flist != NAPI_GRO_CB(p)->is_flist) { 494 NAPI_GRO_CB(skb)->flush = 1; 495 return p; 496 } 497 498 /* Terminate the flow on len mismatch or if it grow "too much". 499 * Under small packet flood GRO count could elsewhere grow a lot 500 * leading to excessive truesize values. 501 * On len mismatch merge the first packet shorter than gso_size, 502 * otherwise complete the GRO packet. 503 */ 504 if (ulen > ntohs(uh2->len)) { 505 pp = p; 506 } else { 507 if (NAPI_GRO_CB(skb)->is_flist) { 508 if (!pskb_may_pull(skb, skb_gro_offset(skb))) { 509 NAPI_GRO_CB(skb)->flush = 1; 510 return NULL; 511 } 512 if ((skb->ip_summed != p->ip_summed) || 513 (skb->csum_level != p->csum_level)) { 514 NAPI_GRO_CB(skb)->flush = 1; 515 return NULL; 516 } 517 ret = skb_gro_receive_list(p, skb); 518 } else { 519 skb_gro_postpull_rcsum(skb, uh, 520 sizeof(struct udphdr)); 521 522 ret = skb_gro_receive(p, skb); 523 } 524 } 525 526 if (ret || ulen != ntohs(uh2->len) || 527 NAPI_GRO_CB(p)->count >= UDP_GRO_CNT_MAX) 528 pp = p; 529 530 return pp; 531 } 532 533 /* mismatch, but we never need to flush */ 534 return NULL; 535 } 536 537 struct sk_buff *udp_gro_receive(struct list_head *head, struct sk_buff *skb, 538 struct udphdr *uh, struct sock *sk) 539 { 540 struct sk_buff *pp = NULL; 541 struct sk_buff *p; 542 struct udphdr *uh2; 543 unsigned int off = skb_gro_offset(skb); 544 int flush = 1; 545 546 /* we can do L4 aggregation only if the packet can't land in a tunnel 547 * otherwise we could corrupt the inner stream 548 */ 549 NAPI_GRO_CB(skb)->is_flist = 0; 550 if (!sk || !udp_sk(sk)->gro_receive) { 551 if (skb->dev->features & NETIF_F_GRO_FRAGLIST) 552 NAPI_GRO_CB(skb)->is_flist = sk ? !udp_sk(sk)->gro_enabled : 1; 553 554 if ((!sk && (skb->dev->features & NETIF_F_GRO_UDP_FWD)) || 555 (sk && udp_sk(sk)->gro_enabled) || NAPI_GRO_CB(skb)->is_flist) 556 return call_gro_receive(udp_gro_receive_segment, head, skb); 557 558 /* no GRO, be sure flush the current packet */ 559 goto out; 560 } 561 562 if (NAPI_GRO_CB(skb)->encap_mark || 563 (uh->check && skb->ip_summed != CHECKSUM_PARTIAL && 564 NAPI_GRO_CB(skb)->csum_cnt == 0 && 565 !NAPI_GRO_CB(skb)->csum_valid)) 566 goto out; 567 568 /* mark that this skb passed once through the tunnel gro layer */ 569 NAPI_GRO_CB(skb)->encap_mark = 1; 570 571 flush = 0; 572 573 list_for_each_entry(p, head, list) { 574 if (!NAPI_GRO_CB(p)->same_flow) 575 continue; 576 577 uh2 = (struct udphdr *)(p->data + off); 578 579 /* Match ports and either checksums are either both zero 580 * or nonzero. 581 */ 582 if ((*(u32 *)&uh->source != *(u32 *)&uh2->source) || 583 (!uh->check ^ !uh2->check)) { 584 NAPI_GRO_CB(p)->same_flow = 0; 585 continue; 586 } 587 } 588 589 skb_gro_pull(skb, sizeof(struct udphdr)); /* pull encapsulating udp header */ 590 skb_gro_postpull_rcsum(skb, uh, sizeof(struct udphdr)); 591 pp = call_gro_receive_sk(udp_sk(sk)->gro_receive, sk, head, skb); 592 593 out: 594 skb_gro_flush_final(skb, pp, flush); 595 return pp; 596 } 597 EXPORT_SYMBOL(udp_gro_receive); 598 599 static struct sock *udp4_gro_lookup_skb(struct sk_buff *skb, __be16 sport, 600 __be16 dport) 601 { 602 const struct iphdr *iph = skb_gro_network_header(skb); 603 604 return __udp4_lib_lookup(dev_net(skb->dev), iph->saddr, sport, 605 iph->daddr, dport, inet_iif(skb), 606 inet_sdif(skb), &udp_table, NULL); 607 } 608 609 INDIRECT_CALLABLE_SCOPE 610 struct sk_buff *udp4_gro_receive(struct list_head *head, struct sk_buff *skb) 611 { 612 struct udphdr *uh = udp_gro_udphdr(skb); 613 struct sock *sk = NULL; 614 struct sk_buff *pp; 615 616 if (unlikely(!uh)) 617 goto flush; 618 619 /* Don't bother verifying checksum if we're going to flush anyway. */ 620 if (NAPI_GRO_CB(skb)->flush) 621 goto skip; 622 623 if (skb_gro_checksum_validate_zero_check(skb, IPPROTO_UDP, uh->check, 624 inet_gro_compute_pseudo)) 625 goto flush; 626 else if (uh->check) 627 skb_gro_checksum_try_convert(skb, IPPROTO_UDP, 628 inet_gro_compute_pseudo); 629 skip: 630 NAPI_GRO_CB(skb)->is_ipv6 = 0; 631 632 if (static_branch_unlikely(&udp_encap_needed_key)) 633 sk = udp4_gro_lookup_skb(skb, uh->source, uh->dest); 634 635 pp = udp_gro_receive(head, skb, uh, sk); 636 return pp; 637 638 flush: 639 NAPI_GRO_CB(skb)->flush = 1; 640 return NULL; 641 } 642 643 static int udp_gro_complete_segment(struct sk_buff *skb) 644 { 645 struct udphdr *uh = udp_hdr(skb); 646 647 skb->csum_start = (unsigned char *)uh - skb->head; 648 skb->csum_offset = offsetof(struct udphdr, check); 649 skb->ip_summed = CHECKSUM_PARTIAL; 650 651 skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count; 652 skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_L4; 653 654 if (skb->encapsulation) 655 skb->inner_transport_header = skb->transport_header; 656 657 return 0; 658 } 659 660 int udp_gro_complete(struct sk_buff *skb, int nhoff, 661 udp_lookup_t lookup) 662 { 663 __be16 newlen = htons(skb->len - nhoff); 664 struct udphdr *uh = (struct udphdr *)(skb->data + nhoff); 665 struct sock *sk; 666 int err; 667 668 uh->len = newlen; 669 670 sk = INDIRECT_CALL_INET(lookup, udp6_lib_lookup_skb, 671 udp4_lib_lookup_skb, skb, uh->source, uh->dest); 672 if (sk && udp_sk(sk)->gro_complete) { 673 skb_shinfo(skb)->gso_type = uh->check ? SKB_GSO_UDP_TUNNEL_CSUM 674 : SKB_GSO_UDP_TUNNEL; 675 676 /* clear the encap mark, so that inner frag_list gro_complete 677 * can take place 678 */ 679 NAPI_GRO_CB(skb)->encap_mark = 0; 680 681 /* Set encapsulation before calling into inner gro_complete() 682 * functions to make them set up the inner offsets. 683 */ 684 skb->encapsulation = 1; 685 err = udp_sk(sk)->gro_complete(sk, skb, 686 nhoff + sizeof(struct udphdr)); 687 } else { 688 err = udp_gro_complete_segment(skb); 689 } 690 691 if (skb->remcsum_offload) 692 skb_shinfo(skb)->gso_type |= SKB_GSO_TUNNEL_REMCSUM; 693 694 return err; 695 } 696 EXPORT_SYMBOL(udp_gro_complete); 697 698 INDIRECT_CALLABLE_SCOPE int udp4_gro_complete(struct sk_buff *skb, int nhoff) 699 { 700 const struct iphdr *iph = ip_hdr(skb); 701 struct udphdr *uh = (struct udphdr *)(skb->data + nhoff); 702 703 /* do fraglist only if there is no outer UDP encap (or we already processed it) */ 704 if (NAPI_GRO_CB(skb)->is_flist && !NAPI_GRO_CB(skb)->encap_mark) { 705 uh->len = htons(skb->len - nhoff); 706 707 skb_shinfo(skb)->gso_type |= (SKB_GSO_FRAGLIST|SKB_GSO_UDP_L4); 708 skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count; 709 710 if (skb->ip_summed == CHECKSUM_UNNECESSARY) { 711 if (skb->csum_level < SKB_MAX_CSUM_LEVEL) 712 skb->csum_level++; 713 } else { 714 skb->ip_summed = CHECKSUM_UNNECESSARY; 715 skb->csum_level = 0; 716 } 717 718 return 0; 719 } 720 721 if (uh->check) 722 uh->check = ~udp_v4_check(skb->len - nhoff, iph->saddr, 723 iph->daddr, 0); 724 725 return udp_gro_complete(skb, nhoff, udp4_lib_lookup_skb); 726 } 727 728 static const struct net_offload udpv4_offload = { 729 .callbacks = { 730 .gso_segment = udp4_ufo_fragment, 731 .gro_receive = udp4_gro_receive, 732 .gro_complete = udp4_gro_complete, 733 }, 734 }; 735 736 int __init udpv4_offload_init(void) 737 { 738 return inet_add_offload(&udpv4_offload, IPPROTO_UDP); 739 } 740