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 mss = skb_shinfo(gso_skb)->gso_size; 278 if (gso_skb->len <= sizeof(*uh) + mss) 279 return ERR_PTR(-EINVAL); 280 281 if (skb_gso_ok(gso_skb, features | NETIF_F_GSO_ROBUST)) { 282 /* Packet is from an untrusted source, reset gso_segs. */ 283 skb_shinfo(gso_skb)->gso_segs = DIV_ROUND_UP(gso_skb->len - sizeof(*uh), 284 mss); 285 return NULL; 286 } 287 288 if (skb_shinfo(gso_skb)->gso_type & SKB_GSO_FRAGLIST) 289 return __udp_gso_segment_list(gso_skb, features, is_ipv6); 290 291 skb_pull(gso_skb, sizeof(*uh)); 292 293 /* clear destructor to avoid skb_segment assigning it to tail */ 294 copy_dtor = gso_skb->destructor == sock_wfree; 295 if (copy_dtor) 296 gso_skb->destructor = NULL; 297 298 segs = skb_segment(gso_skb, features); 299 if (IS_ERR_OR_NULL(segs)) { 300 if (copy_dtor) 301 gso_skb->destructor = sock_wfree; 302 return segs; 303 } 304 305 /* GSO partial and frag_list segmentation only requires splitting 306 * the frame into an MSS multiple and possibly a remainder, both 307 * cases return a GSO skb. So update the mss now. 308 */ 309 if (skb_is_gso(segs)) 310 mss *= skb_shinfo(segs)->gso_segs; 311 312 seg = segs; 313 uh = udp_hdr(seg); 314 315 /* preserve TX timestamp flags and TS key for first segment */ 316 skb_shinfo(seg)->tskey = skb_shinfo(gso_skb)->tskey; 317 skb_shinfo(seg)->tx_flags |= 318 (skb_shinfo(gso_skb)->tx_flags & SKBTX_ANY_TSTAMP); 319 320 /* compute checksum adjustment based on old length versus new */ 321 newlen = htons(sizeof(*uh) + mss); 322 check = csum16_add(csum16_sub(uh->check, uh->len), newlen); 323 324 for (;;) { 325 if (copy_dtor) { 326 seg->destructor = sock_wfree; 327 seg->sk = sk; 328 sum_truesize += seg->truesize; 329 } 330 331 if (!seg->next) 332 break; 333 334 uh->len = newlen; 335 uh->check = check; 336 337 if (seg->ip_summed == CHECKSUM_PARTIAL) 338 gso_reset_checksum(seg, ~check); 339 else 340 uh->check = gso_make_checksum(seg, ~check) ? : 341 CSUM_MANGLED_0; 342 343 seg = seg->next; 344 uh = udp_hdr(seg); 345 } 346 347 /* last packet can be partial gso_size, account for that in checksum */ 348 newlen = htons(skb_tail_pointer(seg) - skb_transport_header(seg) + 349 seg->data_len); 350 check = csum16_add(csum16_sub(uh->check, uh->len), newlen); 351 352 uh->len = newlen; 353 uh->check = check; 354 355 if (seg->ip_summed == CHECKSUM_PARTIAL) 356 gso_reset_checksum(seg, ~check); 357 else 358 uh->check = gso_make_checksum(seg, ~check) ? : CSUM_MANGLED_0; 359 360 /* update refcount for the packet */ 361 if (copy_dtor) { 362 int delta = sum_truesize - gso_skb->truesize; 363 364 /* In some pathological cases, delta can be negative. 365 * We need to either use refcount_add() or refcount_sub_and_test() 366 */ 367 if (likely(delta >= 0)) 368 refcount_add(delta, &sk->sk_wmem_alloc); 369 else 370 WARN_ON_ONCE(refcount_sub_and_test(-delta, &sk->sk_wmem_alloc)); 371 } 372 return segs; 373 } 374 EXPORT_SYMBOL_GPL(__udp_gso_segment); 375 376 static struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb, 377 netdev_features_t features) 378 { 379 struct sk_buff *segs = ERR_PTR(-EINVAL); 380 unsigned int mss; 381 __wsum csum; 382 struct udphdr *uh; 383 struct iphdr *iph; 384 385 if (skb->encapsulation && 386 (skb_shinfo(skb)->gso_type & 387 (SKB_GSO_UDP_TUNNEL|SKB_GSO_UDP_TUNNEL_CSUM))) { 388 segs = skb_udp_tunnel_segment(skb, features, false); 389 goto out; 390 } 391 392 if (!(skb_shinfo(skb)->gso_type & (SKB_GSO_UDP | SKB_GSO_UDP_L4))) 393 goto out; 394 395 if (!pskb_may_pull(skb, sizeof(struct udphdr))) 396 goto out; 397 398 if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) 399 return __udp_gso_segment(skb, features, false); 400 401 mss = skb_shinfo(skb)->gso_size; 402 if (unlikely(skb->len <= mss)) 403 goto out; 404 405 /* Do software UFO. Complete and fill in the UDP checksum as 406 * HW cannot do checksum of UDP packets sent as multiple 407 * IP fragments. 408 */ 409 410 uh = udp_hdr(skb); 411 iph = ip_hdr(skb); 412 413 uh->check = 0; 414 csum = skb_checksum(skb, 0, skb->len, 0); 415 uh->check = udp_v4_check(skb->len, iph->saddr, iph->daddr, csum); 416 if (uh->check == 0) 417 uh->check = CSUM_MANGLED_0; 418 419 skb->ip_summed = CHECKSUM_UNNECESSARY; 420 421 /* If there is no outer header we can fake a checksum offload 422 * due to the fact that we have already done the checksum in 423 * software prior to segmenting the frame. 424 */ 425 if (!skb->encap_hdr_csum) 426 features |= NETIF_F_HW_CSUM; 427 428 /* Fragment the skb. IP headers of the fragments are updated in 429 * inet_gso_segment() 430 */ 431 segs = skb_segment(skb, features); 432 out: 433 return segs; 434 } 435 436 static int skb_gro_receive_list(struct sk_buff *p, struct sk_buff *skb) 437 { 438 if (unlikely(p->len + skb->len >= 65536)) 439 return -E2BIG; 440 441 if (NAPI_GRO_CB(p)->last == p) 442 skb_shinfo(p)->frag_list = skb; 443 else 444 NAPI_GRO_CB(p)->last->next = skb; 445 446 skb_pull(skb, skb_gro_offset(skb)); 447 448 NAPI_GRO_CB(p)->last = skb; 449 NAPI_GRO_CB(p)->count++; 450 p->data_len += skb->len; 451 452 /* sk owenrship - if any - completely transferred to the aggregated packet */ 453 skb->destructor = NULL; 454 p->truesize += skb->truesize; 455 p->len += skb->len; 456 457 NAPI_GRO_CB(skb)->same_flow = 1; 458 459 return 0; 460 } 461 462 463 #define UDP_GRO_CNT_MAX 64 464 static struct sk_buff *udp_gro_receive_segment(struct list_head *head, 465 struct sk_buff *skb) 466 { 467 struct udphdr *uh = udp_gro_udphdr(skb); 468 struct sk_buff *pp = NULL; 469 struct udphdr *uh2; 470 struct sk_buff *p; 471 unsigned int ulen; 472 int ret = 0; 473 474 /* requires non zero csum, for symmetry with GSO */ 475 if (!uh->check) { 476 NAPI_GRO_CB(skb)->flush = 1; 477 return NULL; 478 } 479 480 /* Do not deal with padded or malicious packets, sorry ! */ 481 ulen = ntohs(uh->len); 482 if (ulen <= sizeof(*uh) || ulen != skb_gro_len(skb)) { 483 NAPI_GRO_CB(skb)->flush = 1; 484 return NULL; 485 } 486 /* pull encapsulating udp header */ 487 skb_gro_pull(skb, sizeof(struct udphdr)); 488 489 list_for_each_entry(p, head, list) { 490 if (!NAPI_GRO_CB(p)->same_flow) 491 continue; 492 493 uh2 = udp_hdr(p); 494 495 /* Match ports only, as csum is always non zero */ 496 if ((*(u32 *)&uh->source != *(u32 *)&uh2->source)) { 497 NAPI_GRO_CB(p)->same_flow = 0; 498 continue; 499 } 500 501 if (NAPI_GRO_CB(skb)->is_flist != NAPI_GRO_CB(p)->is_flist) { 502 NAPI_GRO_CB(skb)->flush = 1; 503 return p; 504 } 505 506 /* Terminate the flow on len mismatch or if it grow "too much". 507 * Under small packet flood GRO count could elsewhere grow a lot 508 * leading to excessive truesize values. 509 * On len mismatch merge the first packet shorter than gso_size, 510 * otherwise complete the GRO packet. 511 */ 512 if (ulen > ntohs(uh2->len)) { 513 pp = p; 514 } else { 515 if (NAPI_GRO_CB(skb)->is_flist) { 516 if (!pskb_may_pull(skb, skb_gro_offset(skb))) { 517 NAPI_GRO_CB(skb)->flush = 1; 518 return NULL; 519 } 520 if ((skb->ip_summed != p->ip_summed) || 521 (skb->csum_level != p->csum_level)) { 522 NAPI_GRO_CB(skb)->flush = 1; 523 return NULL; 524 } 525 ret = skb_gro_receive_list(p, skb); 526 } else { 527 skb_gro_postpull_rcsum(skb, uh, 528 sizeof(struct udphdr)); 529 530 ret = skb_gro_receive(p, skb); 531 } 532 } 533 534 if (ret || ulen != ntohs(uh2->len) || 535 NAPI_GRO_CB(p)->count >= UDP_GRO_CNT_MAX) 536 pp = p; 537 538 return pp; 539 } 540 541 /* mismatch, but we never need to flush */ 542 return NULL; 543 } 544 545 struct sk_buff *udp_gro_receive(struct list_head *head, struct sk_buff *skb, 546 struct udphdr *uh, struct sock *sk) 547 { 548 struct sk_buff *pp = NULL; 549 struct sk_buff *p; 550 struct udphdr *uh2; 551 unsigned int off = skb_gro_offset(skb); 552 int flush = 1; 553 554 /* we can do L4 aggregation only if the packet can't land in a tunnel 555 * otherwise we could corrupt the inner stream 556 */ 557 NAPI_GRO_CB(skb)->is_flist = 0; 558 if (!sk || !udp_sk(sk)->gro_receive) { 559 if (skb->dev->features & NETIF_F_GRO_FRAGLIST) 560 NAPI_GRO_CB(skb)->is_flist = sk ? !udp_test_bit(GRO_ENABLED, sk) : 1; 561 562 if ((!sk && (skb->dev->features & NETIF_F_GRO_UDP_FWD)) || 563 (sk && udp_test_bit(GRO_ENABLED, sk)) || NAPI_GRO_CB(skb)->is_flist) 564 return call_gro_receive(udp_gro_receive_segment, head, skb); 565 566 /* no GRO, be sure flush the current packet */ 567 goto out; 568 } 569 570 if (NAPI_GRO_CB(skb)->encap_mark || 571 (uh->check && skb->ip_summed != CHECKSUM_PARTIAL && 572 NAPI_GRO_CB(skb)->csum_cnt == 0 && 573 !NAPI_GRO_CB(skb)->csum_valid)) 574 goto out; 575 576 /* mark that this skb passed once through the tunnel gro layer */ 577 NAPI_GRO_CB(skb)->encap_mark = 1; 578 579 flush = 0; 580 581 list_for_each_entry(p, head, list) { 582 if (!NAPI_GRO_CB(p)->same_flow) 583 continue; 584 585 uh2 = (struct udphdr *)(p->data + off); 586 587 /* Match ports and either checksums are either both zero 588 * or nonzero. 589 */ 590 if ((*(u32 *)&uh->source != *(u32 *)&uh2->source) || 591 (!uh->check ^ !uh2->check)) { 592 NAPI_GRO_CB(p)->same_flow = 0; 593 continue; 594 } 595 } 596 597 skb_gro_pull(skb, sizeof(struct udphdr)); /* pull encapsulating udp header */ 598 skb_gro_postpull_rcsum(skb, uh, sizeof(struct udphdr)); 599 pp = call_gro_receive_sk(udp_sk(sk)->gro_receive, sk, head, skb); 600 601 out: 602 skb_gro_flush_final(skb, pp, flush); 603 return pp; 604 } 605 EXPORT_SYMBOL(udp_gro_receive); 606 607 static struct sock *udp4_gro_lookup_skb(struct sk_buff *skb, __be16 sport, 608 __be16 dport) 609 { 610 const struct iphdr *iph = skb_gro_network_header(skb); 611 struct net *net = dev_net(skb->dev); 612 int iif, sdif; 613 614 inet_get_iif_sdif(skb, &iif, &sdif); 615 616 return __udp4_lib_lookup(net, iph->saddr, sport, 617 iph->daddr, dport, iif, 618 sdif, net->ipv4.udp_table, NULL); 619 } 620 621 INDIRECT_CALLABLE_SCOPE 622 struct sk_buff *udp4_gro_receive(struct list_head *head, struct sk_buff *skb) 623 { 624 struct udphdr *uh = udp_gro_udphdr(skb); 625 struct sock *sk = NULL; 626 struct sk_buff *pp; 627 628 if (unlikely(!uh)) 629 goto flush; 630 631 /* Don't bother verifying checksum if we're going to flush anyway. */ 632 if (NAPI_GRO_CB(skb)->flush) 633 goto skip; 634 635 if (skb_gro_checksum_validate_zero_check(skb, IPPROTO_UDP, uh->check, 636 inet_gro_compute_pseudo)) 637 goto flush; 638 else if (uh->check) 639 skb_gro_checksum_try_convert(skb, IPPROTO_UDP, 640 inet_gro_compute_pseudo); 641 skip: 642 NAPI_GRO_CB(skb)->is_ipv6 = 0; 643 644 if (static_branch_unlikely(&udp_encap_needed_key)) 645 sk = udp4_gro_lookup_skb(skb, uh->source, uh->dest); 646 647 pp = udp_gro_receive(head, skb, uh, sk); 648 return pp; 649 650 flush: 651 NAPI_GRO_CB(skb)->flush = 1; 652 return NULL; 653 } 654 655 static int udp_gro_complete_segment(struct sk_buff *skb) 656 { 657 struct udphdr *uh = udp_hdr(skb); 658 659 skb->csum_start = (unsigned char *)uh - skb->head; 660 skb->csum_offset = offsetof(struct udphdr, check); 661 skb->ip_summed = CHECKSUM_PARTIAL; 662 663 skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count; 664 skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_L4; 665 666 if (skb->encapsulation) 667 skb->inner_transport_header = skb->transport_header; 668 669 return 0; 670 } 671 672 int udp_gro_complete(struct sk_buff *skb, int nhoff, 673 udp_lookup_t lookup) 674 { 675 __be16 newlen = htons(skb->len - nhoff); 676 struct udphdr *uh = (struct udphdr *)(skb->data + nhoff); 677 struct sock *sk; 678 int err; 679 680 uh->len = newlen; 681 682 sk = INDIRECT_CALL_INET(lookup, udp6_lib_lookup_skb, 683 udp4_lib_lookup_skb, skb, uh->source, uh->dest); 684 if (sk && udp_sk(sk)->gro_complete) { 685 skb_shinfo(skb)->gso_type = uh->check ? SKB_GSO_UDP_TUNNEL_CSUM 686 : SKB_GSO_UDP_TUNNEL; 687 688 /* clear the encap mark, so that inner frag_list gro_complete 689 * can take place 690 */ 691 NAPI_GRO_CB(skb)->encap_mark = 0; 692 693 /* Set encapsulation before calling into inner gro_complete() 694 * functions to make them set up the inner offsets. 695 */ 696 skb->encapsulation = 1; 697 err = udp_sk(sk)->gro_complete(sk, skb, 698 nhoff + sizeof(struct udphdr)); 699 } else { 700 err = udp_gro_complete_segment(skb); 701 } 702 703 if (skb->remcsum_offload) 704 skb_shinfo(skb)->gso_type |= SKB_GSO_TUNNEL_REMCSUM; 705 706 return err; 707 } 708 EXPORT_SYMBOL(udp_gro_complete); 709 710 INDIRECT_CALLABLE_SCOPE int udp4_gro_complete(struct sk_buff *skb, int nhoff) 711 { 712 const struct iphdr *iph = ip_hdr(skb); 713 struct udphdr *uh = (struct udphdr *)(skb->data + nhoff); 714 715 /* do fraglist only if there is no outer UDP encap (or we already processed it) */ 716 if (NAPI_GRO_CB(skb)->is_flist && !NAPI_GRO_CB(skb)->encap_mark) { 717 uh->len = htons(skb->len - nhoff); 718 719 skb_shinfo(skb)->gso_type |= (SKB_GSO_FRAGLIST|SKB_GSO_UDP_L4); 720 skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count; 721 722 if (skb->ip_summed == CHECKSUM_UNNECESSARY) { 723 if (skb->csum_level < SKB_MAX_CSUM_LEVEL) 724 skb->csum_level++; 725 } else { 726 skb->ip_summed = CHECKSUM_UNNECESSARY; 727 skb->csum_level = 0; 728 } 729 730 return 0; 731 } 732 733 if (uh->check) 734 uh->check = ~udp_v4_check(skb->len - nhoff, iph->saddr, 735 iph->daddr, 0); 736 737 return udp_gro_complete(skb, nhoff, udp4_lib_lookup_skb); 738 } 739 740 static const struct net_offload udpv4_offload = { 741 .callbacks = { 742 .gso_segment = udp4_ufo_fragment, 743 .gro_receive = udp4_gro_receive, 744 .gro_complete = udp4_gro_complete, 745 }, 746 }; 747 748 int __init udpv4_offload_init(void) 749 { 750 return inet_add_offload(&udpv4_offload, IPPROTO_UDP); 751 } 752