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/gso.h> 12 #include <net/udp.h> 13 #include <net/protocol.h> 14 #include <net/inet_common.h> 15 16 static struct sk_buff *__skb_udp_tunnel_segment(struct sk_buff *skb, 17 netdev_features_t features, 18 struct sk_buff *(*gso_inner_segment)(struct sk_buff *skb, 19 netdev_features_t features), 20 __be16 new_protocol, bool is_ipv6) 21 { 22 int tnl_hlen = skb_inner_mac_header(skb) - skb_transport_header(skb); 23 bool remcsum, need_csum, offload_csum, gso_partial; 24 struct sk_buff *segs = ERR_PTR(-EINVAL); 25 struct udphdr *uh = udp_hdr(skb); 26 u16 mac_offset = skb->mac_header; 27 __be16 protocol = skb->protocol; 28 u16 mac_len = skb->mac_len; 29 int udp_offset, outer_hlen; 30 __wsum partial; 31 bool need_ipsec; 32 33 if (unlikely(!pskb_may_pull(skb, tnl_hlen))) 34 goto out; 35 36 /* Adjust partial header checksum to negate old length. 37 * We cannot rely on the value contained in uh->len as it is 38 * possible that the actual value exceeds the boundaries of the 39 * 16 bit length field due to the header being added outside of an 40 * IP or IPv6 frame that was already limited to 64K - 1. 41 */ 42 if (skb_shinfo(skb)->gso_type & SKB_GSO_PARTIAL) 43 partial = (__force __wsum)uh->len; 44 else 45 partial = (__force __wsum)htonl(skb->len); 46 partial = csum_sub(csum_unfold(uh->check), partial); 47 48 /* setup inner skb. */ 49 skb->encapsulation = 0; 50 SKB_GSO_CB(skb)->encap_level = 0; 51 __skb_pull(skb, tnl_hlen); 52 skb_reset_mac_header(skb); 53 skb_set_network_header(skb, skb_inner_network_offset(skb)); 54 skb_set_transport_header(skb, skb_inner_transport_offset(skb)); 55 skb->mac_len = skb_inner_network_offset(skb); 56 skb->protocol = new_protocol; 57 58 need_csum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL_CSUM); 59 skb->encap_hdr_csum = need_csum; 60 61 remcsum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TUNNEL_REMCSUM); 62 skb->remcsum_offload = remcsum; 63 64 need_ipsec = skb_dst(skb) && dst_xfrm(skb_dst(skb)); 65 /* Try to offload checksum if possible */ 66 offload_csum = !!(need_csum && 67 !need_ipsec && 68 (skb->dev->features & 69 (is_ipv6 ? (NETIF_F_HW_CSUM | NETIF_F_IPV6_CSUM) : 70 (NETIF_F_HW_CSUM | NETIF_F_IP_CSUM)))); 71 72 features &= skb->dev->hw_enc_features; 73 if (need_csum) 74 features &= ~NETIF_F_SCTP_CRC; 75 76 /* The only checksum offload we care about from here on out is the 77 * outer one so strip the existing checksum feature flags and 78 * instead set the flag based on our outer checksum offload value. 79 */ 80 if (remcsum) { 81 features &= ~NETIF_F_CSUM_MASK; 82 if (!need_csum || offload_csum) 83 features |= NETIF_F_HW_CSUM; 84 } 85 86 /* segment inner packet. */ 87 segs = gso_inner_segment(skb, features); 88 if (IS_ERR_OR_NULL(segs)) { 89 skb_gso_error_unwind(skb, protocol, tnl_hlen, mac_offset, 90 mac_len); 91 goto out; 92 } 93 94 gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL); 95 96 outer_hlen = skb_tnl_header_len(skb); 97 udp_offset = outer_hlen - tnl_hlen; 98 skb = segs; 99 do { 100 unsigned int len; 101 102 if (remcsum) 103 skb->ip_summed = CHECKSUM_NONE; 104 105 /* Set up inner headers if we are offloading inner checksum */ 106 if (skb->ip_summed == CHECKSUM_PARTIAL) { 107 skb_reset_inner_headers(skb); 108 skb->encapsulation = 1; 109 } 110 111 skb->mac_len = mac_len; 112 skb->protocol = protocol; 113 114 __skb_push(skb, outer_hlen); 115 skb_reset_mac_header(skb); 116 skb_set_network_header(skb, mac_len); 117 skb_set_transport_header(skb, udp_offset); 118 len = skb->len - udp_offset; 119 uh = udp_hdr(skb); 120 121 /* If we are only performing partial GSO the inner header 122 * will be using a length value equal to only one MSS sized 123 * segment instead of the entire frame. 124 */ 125 if (gso_partial && skb_is_gso(skb)) { 126 uh->len = htons(skb_shinfo(skb)->gso_size + 127 SKB_GSO_CB(skb)->data_offset + 128 skb->head - (unsigned char *)uh); 129 } else { 130 uh->len = htons(len); 131 } 132 133 if (!need_csum) 134 continue; 135 136 uh->check = ~csum_fold(csum_add(partial, 137 (__force __wsum)htonl(len))); 138 139 if (skb->encapsulation || !offload_csum) { 140 uh->check = gso_make_checksum(skb, ~uh->check); 141 if (uh->check == 0) 142 uh->check = CSUM_MANGLED_0; 143 } else { 144 skb->ip_summed = CHECKSUM_PARTIAL; 145 skb->csum_start = skb_transport_header(skb) - skb->head; 146 skb->csum_offset = offsetof(struct udphdr, check); 147 } 148 } while ((skb = skb->next)); 149 out: 150 return segs; 151 } 152 153 struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb, 154 netdev_features_t features, 155 bool is_ipv6) 156 { 157 const struct net_offload __rcu **offloads; 158 __be16 protocol = skb->protocol; 159 const struct net_offload *ops; 160 struct sk_buff *segs = ERR_PTR(-EINVAL); 161 struct sk_buff *(*gso_inner_segment)(struct sk_buff *skb, 162 netdev_features_t features); 163 164 rcu_read_lock(); 165 166 switch (skb->inner_protocol_type) { 167 case ENCAP_TYPE_ETHER: 168 protocol = skb->inner_protocol; 169 gso_inner_segment = skb_mac_gso_segment; 170 break; 171 case ENCAP_TYPE_IPPROTO: 172 offloads = is_ipv6 ? inet6_offloads : inet_offloads; 173 ops = rcu_dereference(offloads[skb->inner_ipproto]); 174 if (!ops || !ops->callbacks.gso_segment) 175 goto out_unlock; 176 gso_inner_segment = ops->callbacks.gso_segment; 177 break; 178 default: 179 goto out_unlock; 180 } 181 182 segs = __skb_udp_tunnel_segment(skb, features, gso_inner_segment, 183 protocol, is_ipv6); 184 185 out_unlock: 186 rcu_read_unlock(); 187 188 return segs; 189 } 190 EXPORT_SYMBOL(skb_udp_tunnel_segment); 191 192 static void __udpv4_gso_segment_csum(struct sk_buff *seg, 193 __be32 *oldip, __be32 *newip, 194 __be16 *oldport, __be16 *newport) 195 { 196 struct udphdr *uh; 197 struct iphdr *iph; 198 199 if (*oldip == *newip && *oldport == *newport) 200 return; 201 202 uh = udp_hdr(seg); 203 iph = ip_hdr(seg); 204 205 if (uh->check) { 206 inet_proto_csum_replace4(&uh->check, seg, *oldip, *newip, 207 true); 208 inet_proto_csum_replace2(&uh->check, seg, *oldport, *newport, 209 false); 210 if (!uh->check) 211 uh->check = CSUM_MANGLED_0; 212 } 213 *oldport = *newport; 214 215 csum_replace4(&iph->check, *oldip, *newip); 216 *oldip = *newip; 217 } 218 219 static struct sk_buff *__udpv4_gso_segment_list_csum(struct sk_buff *segs) 220 { 221 struct sk_buff *seg; 222 struct udphdr *uh, *uh2; 223 struct iphdr *iph, *iph2; 224 225 seg = segs; 226 uh = udp_hdr(seg); 227 iph = ip_hdr(seg); 228 229 if ((udp_hdr(seg)->dest == udp_hdr(seg->next)->dest) && 230 (udp_hdr(seg)->source == udp_hdr(seg->next)->source) && 231 (ip_hdr(seg)->daddr == ip_hdr(seg->next)->daddr) && 232 (ip_hdr(seg)->saddr == ip_hdr(seg->next)->saddr)) 233 return segs; 234 235 while ((seg = seg->next)) { 236 uh2 = udp_hdr(seg); 237 iph2 = ip_hdr(seg); 238 239 __udpv4_gso_segment_csum(seg, 240 &iph2->saddr, &iph->saddr, 241 &uh2->source, &uh->source); 242 __udpv4_gso_segment_csum(seg, 243 &iph2->daddr, &iph->daddr, 244 &uh2->dest, &uh->dest); 245 } 246 247 return segs; 248 } 249 250 static struct sk_buff *__udp_gso_segment_list(struct sk_buff *skb, 251 netdev_features_t features, 252 bool is_ipv6) 253 { 254 unsigned int mss = skb_shinfo(skb)->gso_size; 255 256 skb = skb_segment_list(skb, features, skb_mac_header_len(skb)); 257 if (IS_ERR(skb)) 258 return skb; 259 260 udp_hdr(skb)->len = htons(sizeof(struct udphdr) + mss); 261 262 return is_ipv6 ? skb : __udpv4_gso_segment_list_csum(skb); 263 } 264 265 struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb, 266 netdev_features_t features, bool is_ipv6) 267 { 268 struct sock *sk = gso_skb->sk; 269 unsigned int sum_truesize = 0; 270 struct sk_buff *segs, *seg; 271 struct udphdr *uh; 272 unsigned int mss; 273 bool copy_dtor; 274 __sum16 check; 275 __be16 newlen; 276 277 if (skb_shinfo(gso_skb)->gso_type & SKB_GSO_FRAGLIST) 278 return __udp_gso_segment_list(gso_skb, features, is_ipv6); 279 280 mss = skb_shinfo(gso_skb)->gso_size; 281 if (gso_skb->len <= sizeof(*uh) + mss) 282 return ERR_PTR(-EINVAL); 283 284 skb_pull(gso_skb, sizeof(*uh)); 285 286 /* clear destructor to avoid skb_segment assigning it to tail */ 287 copy_dtor = gso_skb->destructor == sock_wfree; 288 if (copy_dtor) 289 gso_skb->destructor = NULL; 290 291 segs = skb_segment(gso_skb, features); 292 if (IS_ERR_OR_NULL(segs)) { 293 if (copy_dtor) 294 gso_skb->destructor = sock_wfree; 295 return segs; 296 } 297 298 /* GSO partial and frag_list segmentation only requires splitting 299 * the frame into an MSS multiple and possibly a remainder, both 300 * cases return a GSO skb. So update the mss now. 301 */ 302 if (skb_is_gso(segs)) 303 mss *= skb_shinfo(segs)->gso_segs; 304 305 seg = segs; 306 uh = udp_hdr(seg); 307 308 /* preserve TX timestamp flags and TS key for first segment */ 309 skb_shinfo(seg)->tskey = skb_shinfo(gso_skb)->tskey; 310 skb_shinfo(seg)->tx_flags |= 311 (skb_shinfo(gso_skb)->tx_flags & SKBTX_ANY_TSTAMP); 312 313 /* compute checksum adjustment based on old length versus new */ 314 newlen = htons(sizeof(*uh) + mss); 315 check = csum16_add(csum16_sub(uh->check, uh->len), newlen); 316 317 for (;;) { 318 if (copy_dtor) { 319 seg->destructor = sock_wfree; 320 seg->sk = sk; 321 sum_truesize += seg->truesize; 322 } 323 324 if (!seg->next) 325 break; 326 327 uh->len = newlen; 328 uh->check = check; 329 330 if (seg->ip_summed == CHECKSUM_PARTIAL) 331 gso_reset_checksum(seg, ~check); 332 else 333 uh->check = gso_make_checksum(seg, ~check) ? : 334 CSUM_MANGLED_0; 335 336 seg = seg->next; 337 uh = udp_hdr(seg); 338 } 339 340 /* last packet can be partial gso_size, account for that in checksum */ 341 newlen = htons(skb_tail_pointer(seg) - skb_transport_header(seg) + 342 seg->data_len); 343 check = csum16_add(csum16_sub(uh->check, uh->len), newlen); 344 345 uh->len = newlen; 346 uh->check = check; 347 348 if (seg->ip_summed == CHECKSUM_PARTIAL) 349 gso_reset_checksum(seg, ~check); 350 else 351 uh->check = gso_make_checksum(seg, ~check) ? : CSUM_MANGLED_0; 352 353 /* update refcount for the packet */ 354 if (copy_dtor) { 355 int delta = sum_truesize - gso_skb->truesize; 356 357 /* In some pathological cases, delta can be negative. 358 * We need to either use refcount_add() or refcount_sub_and_test() 359 */ 360 if (likely(delta >= 0)) 361 refcount_add(delta, &sk->sk_wmem_alloc); 362 else 363 WARN_ON_ONCE(refcount_sub_and_test(-delta, &sk->sk_wmem_alloc)); 364 } 365 return segs; 366 } 367 EXPORT_SYMBOL_GPL(__udp_gso_segment); 368 369 static struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb, 370 netdev_features_t features) 371 { 372 struct sk_buff *segs = ERR_PTR(-EINVAL); 373 unsigned int mss; 374 __wsum csum; 375 struct udphdr *uh; 376 struct iphdr *iph; 377 378 if (skb->encapsulation && 379 (skb_shinfo(skb)->gso_type & 380 (SKB_GSO_UDP_TUNNEL|SKB_GSO_UDP_TUNNEL_CSUM))) { 381 segs = skb_udp_tunnel_segment(skb, features, false); 382 goto out; 383 } 384 385 if (!(skb_shinfo(skb)->gso_type & (SKB_GSO_UDP | SKB_GSO_UDP_L4))) 386 goto out; 387 388 if (!pskb_may_pull(skb, sizeof(struct udphdr))) 389 goto out; 390 391 if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4 && 392 !skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) 393 return __udp_gso_segment(skb, features, false); 394 395 mss = skb_shinfo(skb)->gso_size; 396 if (unlikely(skb->len <= mss)) 397 goto out; 398 399 /* Do software UFO. Complete and fill in the UDP checksum as 400 * HW cannot do checksum of UDP packets sent as multiple 401 * IP fragments. 402 */ 403 404 uh = udp_hdr(skb); 405 iph = ip_hdr(skb); 406 407 uh->check = 0; 408 csum = skb_checksum(skb, 0, skb->len, 0); 409 uh->check = udp_v4_check(skb->len, iph->saddr, iph->daddr, csum); 410 if (uh->check == 0) 411 uh->check = CSUM_MANGLED_0; 412 413 skb->ip_summed = CHECKSUM_UNNECESSARY; 414 415 /* If there is no outer header we can fake a checksum offload 416 * due to the fact that we have already done the checksum in 417 * software prior to segmenting the frame. 418 */ 419 if (!skb->encap_hdr_csum) 420 features |= NETIF_F_HW_CSUM; 421 422 /* Fragment the skb. IP headers of the fragments are updated in 423 * inet_gso_segment() 424 */ 425 segs = skb_segment(skb, features); 426 out: 427 return segs; 428 } 429 430 static int skb_gro_receive_list(struct sk_buff *p, struct sk_buff *skb) 431 { 432 if (unlikely(p->len + skb->len >= 65536)) 433 return -E2BIG; 434 435 if (NAPI_GRO_CB(p)->last == p) 436 skb_shinfo(p)->frag_list = skb; 437 else 438 NAPI_GRO_CB(p)->last->next = skb; 439 440 skb_pull(skb, skb_gro_offset(skb)); 441 442 NAPI_GRO_CB(p)->last = skb; 443 NAPI_GRO_CB(p)->count++; 444 p->data_len += skb->len; 445 446 /* sk owenrship - if any - completely transferred to the aggregated packet */ 447 skb->destructor = NULL; 448 p->truesize += skb->truesize; 449 p->len += skb->len; 450 451 NAPI_GRO_CB(skb)->same_flow = 1; 452 453 return 0; 454 } 455 456 457 #define UDP_GRO_CNT_MAX 64 458 static struct sk_buff *udp_gro_receive_segment(struct list_head *head, 459 struct sk_buff *skb) 460 { 461 struct udphdr *uh = udp_gro_udphdr(skb); 462 struct sk_buff *pp = NULL; 463 struct udphdr *uh2; 464 struct sk_buff *p; 465 unsigned int ulen; 466 int ret = 0; 467 468 /* requires non zero csum, for symmetry with GSO */ 469 if (!uh->check) { 470 NAPI_GRO_CB(skb)->flush = 1; 471 return NULL; 472 } 473 474 /* Do not deal with padded or malicious packets, sorry ! */ 475 ulen = ntohs(uh->len); 476 if (ulen <= sizeof(*uh) || ulen != skb_gro_len(skb)) { 477 NAPI_GRO_CB(skb)->flush = 1; 478 return NULL; 479 } 480 /* pull encapsulating udp header */ 481 skb_gro_pull(skb, sizeof(struct udphdr)); 482 483 list_for_each_entry(p, head, list) { 484 if (!NAPI_GRO_CB(p)->same_flow) 485 continue; 486 487 uh2 = udp_hdr(p); 488 489 /* Match ports only, as csum is always non zero */ 490 if ((*(u32 *)&uh->source != *(u32 *)&uh2->source)) { 491 NAPI_GRO_CB(p)->same_flow = 0; 492 continue; 493 } 494 495 if (NAPI_GRO_CB(skb)->is_flist != NAPI_GRO_CB(p)->is_flist) { 496 NAPI_GRO_CB(skb)->flush = 1; 497 return p; 498 } 499 500 /* Terminate the flow on len mismatch or if it grow "too much". 501 * Under small packet flood GRO count could elsewhere grow a lot 502 * leading to excessive truesize values. 503 * On len mismatch merge the first packet shorter than gso_size, 504 * otherwise complete the GRO packet. 505 */ 506 if (ulen > ntohs(uh2->len)) { 507 pp = p; 508 } else { 509 if (NAPI_GRO_CB(skb)->is_flist) { 510 if (!pskb_may_pull(skb, skb_gro_offset(skb))) { 511 NAPI_GRO_CB(skb)->flush = 1; 512 return NULL; 513 } 514 if ((skb->ip_summed != p->ip_summed) || 515 (skb->csum_level != p->csum_level)) { 516 NAPI_GRO_CB(skb)->flush = 1; 517 return NULL; 518 } 519 ret = skb_gro_receive_list(p, skb); 520 } else { 521 skb_gro_postpull_rcsum(skb, uh, 522 sizeof(struct udphdr)); 523 524 ret = skb_gro_receive(p, skb); 525 } 526 } 527 528 if (ret || ulen != ntohs(uh2->len) || 529 NAPI_GRO_CB(p)->count >= UDP_GRO_CNT_MAX) 530 pp = p; 531 532 return pp; 533 } 534 535 /* mismatch, but we never need to flush */ 536 return NULL; 537 } 538 539 struct sk_buff *udp_gro_receive(struct list_head *head, struct sk_buff *skb, 540 struct udphdr *uh, struct sock *sk) 541 { 542 struct sk_buff *pp = NULL; 543 struct sk_buff *p; 544 struct udphdr *uh2; 545 unsigned int off = skb_gro_offset(skb); 546 int flush = 1; 547 548 /* we can do L4 aggregation only if the packet can't land in a tunnel 549 * otherwise we could corrupt the inner stream 550 */ 551 NAPI_GRO_CB(skb)->is_flist = 0; 552 if (!sk || !udp_sk(sk)->gro_receive) { 553 if (skb->dev->features & NETIF_F_GRO_FRAGLIST) 554 NAPI_GRO_CB(skb)->is_flist = sk ? !udp_sk(sk)->gro_enabled : 1; 555 556 if ((!sk && (skb->dev->features & NETIF_F_GRO_UDP_FWD)) || 557 (sk && udp_sk(sk)->gro_enabled) || NAPI_GRO_CB(skb)->is_flist) 558 return call_gro_receive(udp_gro_receive_segment, head, skb); 559 560 /* no GRO, be sure flush the current packet */ 561 goto out; 562 } 563 564 if (NAPI_GRO_CB(skb)->encap_mark || 565 (uh->check && skb->ip_summed != CHECKSUM_PARTIAL && 566 NAPI_GRO_CB(skb)->csum_cnt == 0 && 567 !NAPI_GRO_CB(skb)->csum_valid)) 568 goto out; 569 570 /* mark that this skb passed once through the tunnel gro layer */ 571 NAPI_GRO_CB(skb)->encap_mark = 1; 572 573 flush = 0; 574 575 list_for_each_entry(p, head, list) { 576 if (!NAPI_GRO_CB(p)->same_flow) 577 continue; 578 579 uh2 = (struct udphdr *)(p->data + off); 580 581 /* Match ports and either checksums are either both zero 582 * or nonzero. 583 */ 584 if ((*(u32 *)&uh->source != *(u32 *)&uh2->source) || 585 (!uh->check ^ !uh2->check)) { 586 NAPI_GRO_CB(p)->same_flow = 0; 587 continue; 588 } 589 } 590 591 skb_gro_pull(skb, sizeof(struct udphdr)); /* pull encapsulating udp header */ 592 skb_gro_postpull_rcsum(skb, uh, sizeof(struct udphdr)); 593 pp = call_gro_receive_sk(udp_sk(sk)->gro_receive, sk, head, skb); 594 595 out: 596 skb_gro_flush_final(skb, pp, flush); 597 return pp; 598 } 599 EXPORT_SYMBOL(udp_gro_receive); 600 601 static struct sock *udp4_gro_lookup_skb(struct sk_buff *skb, __be16 sport, 602 __be16 dport) 603 { 604 const struct iphdr *iph = skb_gro_network_header(skb); 605 struct net *net = dev_net(skb->dev); 606 607 return __udp4_lib_lookup(net, iph->saddr, sport, 608 iph->daddr, dport, inet_iif(skb), 609 inet_sdif(skb), net->ipv4.udp_table, NULL); 610 } 611 612 INDIRECT_CALLABLE_SCOPE 613 struct sk_buff *udp4_gro_receive(struct list_head *head, struct sk_buff *skb) 614 { 615 struct udphdr *uh = udp_gro_udphdr(skb); 616 struct sock *sk = NULL; 617 struct sk_buff *pp; 618 619 if (unlikely(!uh)) 620 goto flush; 621 622 /* Don't bother verifying checksum if we're going to flush anyway. */ 623 if (NAPI_GRO_CB(skb)->flush) 624 goto skip; 625 626 if (skb_gro_checksum_validate_zero_check(skb, IPPROTO_UDP, uh->check, 627 inet_gro_compute_pseudo)) 628 goto flush; 629 else if (uh->check) 630 skb_gro_checksum_try_convert(skb, IPPROTO_UDP, 631 inet_gro_compute_pseudo); 632 skip: 633 NAPI_GRO_CB(skb)->is_ipv6 = 0; 634 635 if (static_branch_unlikely(&udp_encap_needed_key)) 636 sk = udp4_gro_lookup_skb(skb, uh->source, uh->dest); 637 638 pp = udp_gro_receive(head, skb, uh, sk); 639 return pp; 640 641 flush: 642 NAPI_GRO_CB(skb)->flush = 1; 643 return NULL; 644 } 645 646 static int udp_gro_complete_segment(struct sk_buff *skb) 647 { 648 struct udphdr *uh = udp_hdr(skb); 649 650 skb->csum_start = (unsigned char *)uh - skb->head; 651 skb->csum_offset = offsetof(struct udphdr, check); 652 skb->ip_summed = CHECKSUM_PARTIAL; 653 654 skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count; 655 skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_L4; 656 657 if (skb->encapsulation) 658 skb->inner_transport_header = skb->transport_header; 659 660 return 0; 661 } 662 663 int udp_gro_complete(struct sk_buff *skb, int nhoff, 664 udp_lookup_t lookup) 665 { 666 __be16 newlen = htons(skb->len - nhoff); 667 struct udphdr *uh = (struct udphdr *)(skb->data + nhoff); 668 struct sock *sk; 669 int err; 670 671 uh->len = newlen; 672 673 sk = INDIRECT_CALL_INET(lookup, udp6_lib_lookup_skb, 674 udp4_lib_lookup_skb, skb, uh->source, uh->dest); 675 if (sk && udp_sk(sk)->gro_complete) { 676 skb_shinfo(skb)->gso_type = uh->check ? SKB_GSO_UDP_TUNNEL_CSUM 677 : SKB_GSO_UDP_TUNNEL; 678 679 /* clear the encap mark, so that inner frag_list gro_complete 680 * can take place 681 */ 682 NAPI_GRO_CB(skb)->encap_mark = 0; 683 684 /* Set encapsulation before calling into inner gro_complete() 685 * functions to make them set up the inner offsets. 686 */ 687 skb->encapsulation = 1; 688 err = udp_sk(sk)->gro_complete(sk, skb, 689 nhoff + sizeof(struct udphdr)); 690 } else { 691 err = udp_gro_complete_segment(skb); 692 } 693 694 if (skb->remcsum_offload) 695 skb_shinfo(skb)->gso_type |= SKB_GSO_TUNNEL_REMCSUM; 696 697 return err; 698 } 699 EXPORT_SYMBOL(udp_gro_complete); 700 701 INDIRECT_CALLABLE_SCOPE int udp4_gro_complete(struct sk_buff *skb, int nhoff) 702 { 703 const struct iphdr *iph = ip_hdr(skb); 704 struct udphdr *uh = (struct udphdr *)(skb->data + nhoff); 705 706 /* do fraglist only if there is no outer UDP encap (or we already processed it) */ 707 if (NAPI_GRO_CB(skb)->is_flist && !NAPI_GRO_CB(skb)->encap_mark) { 708 uh->len = htons(skb->len - nhoff); 709 710 skb_shinfo(skb)->gso_type |= (SKB_GSO_FRAGLIST|SKB_GSO_UDP_L4); 711 skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count; 712 713 if (skb->ip_summed == CHECKSUM_UNNECESSARY) { 714 if (skb->csum_level < SKB_MAX_CSUM_LEVEL) 715 skb->csum_level++; 716 } else { 717 skb->ip_summed = CHECKSUM_UNNECESSARY; 718 skb->csum_level = 0; 719 } 720 721 return 0; 722 } 723 724 if (uh->check) 725 uh->check = ~udp_v4_check(skb->len - nhoff, iph->saddr, 726 iph->daddr, 0); 727 728 return udp_gro_complete(skb, nhoff, udp4_lib_lookup_skb); 729 } 730 731 static const struct net_offload udpv4_offload = { 732 .callbacks = { 733 .gso_segment = udp4_ufo_fragment, 734 .gro_receive = udp4_gro_receive, 735 .gro_complete = udp4_gro_complete, 736 }, 737 }; 738 739 int __init udpv4_offload_init(void) 740 { 741 return inet_add_offload(&udpv4_offload, IPPROTO_UDP); 742 } 743