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 16static 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)); 149out: 150 return segs; 151} 152 153struct 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 185out_unlock: 186 rcu_read_unlock(); 187 188 return segs; 189} 190EXPORT_SYMBOL(skb_udp_tunnel_segment); 191 192static 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 219static 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 250static 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 265struct 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} 374EXPORT_SYMBOL_GPL(__udp_gso_segment); 375 376static 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); 432out: 433 return segs; 434} 435 436static 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 ownership - if any - completely transferred to the aggregated packet */ 453 skb->destructor = NULL; 454 skb->sk = NULL; 455 p->truesize += skb->truesize; 456 p->len += skb->len; 457 458 NAPI_GRO_CB(skb)->same_flow = 1; 459 460 return 0; 461} 462 463 464#define UDP_GRO_CNT_MAX 64 465static struct sk_buff *udp_gro_receive_segment(struct list_head *head, 466 struct sk_buff *skb) 467{ 468 struct udphdr *uh = udp_gro_udphdr(skb); 469 struct sk_buff *pp = NULL; 470 struct udphdr *uh2; 471 struct sk_buff *p; 472 unsigned int ulen; 473 int ret = 0; 474 475 /* requires non zero csum, for symmetry with GSO */ 476 if (!uh->check) { 477 NAPI_GRO_CB(skb)->flush = 1; 478 return NULL; 479 } 480 481 /* Do not deal with padded or malicious packets, sorry ! */ 482 ulen = ntohs(uh->len); 483 if (ulen <= sizeof(*uh) || ulen != skb_gro_len(skb)) { 484 NAPI_GRO_CB(skb)->flush = 1; 485 return NULL; 486 } 487 /* pull encapsulating udp header */ 488 skb_gro_pull(skb, sizeof(struct udphdr)); 489 490 list_for_each_entry(p, head, list) { 491 if (!NAPI_GRO_CB(p)->same_flow) 492 continue; 493 494 uh2 = udp_hdr(p); 495 496 /* Match ports only, as csum is always non zero */ 497 if ((*(u32 *)&uh->source != *(u32 *)&uh2->source)) { 498 NAPI_GRO_CB(p)->same_flow = 0; 499 continue; 500 } 501 502 if (NAPI_GRO_CB(skb)->is_flist != NAPI_GRO_CB(p)->is_flist) { 503 NAPI_GRO_CB(skb)->flush = 1; 504 return p; 505 } 506 507 /* Terminate the flow on len mismatch or if it grow "too much". 508 * Under small packet flood GRO count could elsewhere grow a lot 509 * leading to excessive truesize values. 510 * On len mismatch merge the first packet shorter than gso_size, 511 * otherwise complete the GRO packet. 512 */ 513 if (ulen > ntohs(uh2->len)) { 514 pp = p; 515 } else { 516 if (NAPI_GRO_CB(skb)->is_flist) { 517 if (!pskb_may_pull(skb, skb_gro_offset(skb))) { 518 NAPI_GRO_CB(skb)->flush = 1; 519 return NULL; 520 } 521 if ((skb->ip_summed != p->ip_summed) || 522 (skb->csum_level != p->csum_level)) { 523 NAPI_GRO_CB(skb)->flush = 1; 524 return NULL; 525 } 526 ret = skb_gro_receive_list(p, skb); 527 } else { 528 skb_gro_postpull_rcsum(skb, uh, 529 sizeof(struct udphdr)); 530 531 ret = skb_gro_receive(p, skb); 532 } 533 } 534 535 if (ret || ulen != ntohs(uh2->len) || 536 NAPI_GRO_CB(p)->count >= UDP_GRO_CNT_MAX) 537 pp = p; 538 539 return pp; 540 } 541 542 /* mismatch, but we never need to flush */ 543 return NULL; 544} 545 546struct sk_buff *udp_gro_receive(struct list_head *head, struct sk_buff *skb, 547 struct udphdr *uh, struct sock *sk) 548{ 549 struct sk_buff *pp = NULL; 550 struct sk_buff *p; 551 struct udphdr *uh2; 552 unsigned int off = skb_gro_offset(skb); 553 int flush = 1; 554 555 /* We can do L4 aggregation only if the packet can't land in a tunnel 556 * otherwise we could corrupt the inner stream. Detecting such packets 557 * cannot be foolproof and the aggregation might still happen in some 558 * cases. Such packets should be caught in udp_unexpected_gso later. 559 */ 560 NAPI_GRO_CB(skb)->is_flist = 0; 561 if (!sk || !udp_sk(sk)->gro_receive) { 562 /* If the packet was locally encapsulated in a UDP tunnel that 563 * wasn't detected above, do not GRO. 564 */ 565 if (skb->encapsulation) 566 goto out; 567 568 if (skb->dev->features & NETIF_F_GRO_FRAGLIST) 569 NAPI_GRO_CB(skb)->is_flist = sk ? !udp_test_bit(GRO_ENABLED, sk) : 1; 570 571 if ((!sk && (skb->dev->features & NETIF_F_GRO_UDP_FWD)) || 572 (sk && udp_test_bit(GRO_ENABLED, sk)) || NAPI_GRO_CB(skb)->is_flist) 573 return call_gro_receive(udp_gro_receive_segment, head, skb); 574 575 /* no GRO, be sure flush the current packet */ 576 goto out; 577 } 578 579 if (NAPI_GRO_CB(skb)->encap_mark || 580 (uh->check && skb->ip_summed != CHECKSUM_PARTIAL && 581 NAPI_GRO_CB(skb)->csum_cnt == 0 && 582 !NAPI_GRO_CB(skb)->csum_valid)) 583 goto out; 584 585 /* mark that this skb passed once through the tunnel gro layer */ 586 NAPI_GRO_CB(skb)->encap_mark = 1; 587 588 flush = 0; 589 590 list_for_each_entry(p, head, list) { 591 if (!NAPI_GRO_CB(p)->same_flow) 592 continue; 593 594 uh2 = (struct udphdr *)(p->data + off); 595 596 /* Match ports and either checksums are either both zero 597 * or nonzero. 598 */ 599 if ((*(u32 *)&uh->source != *(u32 *)&uh2->source) || 600 (!uh->check ^ !uh2->check)) { 601 NAPI_GRO_CB(p)->same_flow = 0; 602 continue; 603 } 604 } 605 606 skb_gro_pull(skb, sizeof(struct udphdr)); /* pull encapsulating udp header */ 607 skb_gro_postpull_rcsum(skb, uh, sizeof(struct udphdr)); 608 pp = call_gro_receive_sk(udp_sk(sk)->gro_receive, sk, head, skb); 609 610out: 611 skb_gro_flush_final(skb, pp, flush); 612 return pp; 613} 614EXPORT_SYMBOL(udp_gro_receive); 615 616static struct sock *udp4_gro_lookup_skb(struct sk_buff *skb, __be16 sport, 617 __be16 dport) 618{ 619 const struct iphdr *iph = skb_gro_network_header(skb); 620 struct net *net = dev_net(skb->dev); 621 int iif, sdif; 622 623 inet_get_iif_sdif(skb, &iif, &sdif); 624 625 return __udp4_lib_lookup(net, iph->saddr, sport, 626 iph->daddr, dport, iif, 627 sdif, net->ipv4.udp_table, NULL); 628} 629 630INDIRECT_CALLABLE_SCOPE 631struct sk_buff *udp4_gro_receive(struct list_head *head, struct sk_buff *skb) 632{ 633 struct udphdr *uh = udp_gro_udphdr(skb); 634 struct sock *sk = NULL; 635 struct sk_buff *pp; 636 637 if (unlikely(!uh)) 638 goto flush; 639 640 /* Don't bother verifying checksum if we're going to flush anyway. */ 641 if (NAPI_GRO_CB(skb)->flush) 642 goto skip; 643 644 if (skb_gro_checksum_validate_zero_check(skb, IPPROTO_UDP, uh->check, 645 inet_gro_compute_pseudo)) 646 goto flush; 647 else if (uh->check) 648 skb_gro_checksum_try_convert(skb, IPPROTO_UDP, 649 inet_gro_compute_pseudo); 650skip: 651 NAPI_GRO_CB(skb)->is_ipv6 = 0; 652 653 if (static_branch_unlikely(&udp_encap_needed_key)) 654 sk = udp4_gro_lookup_skb(skb, uh->source, uh->dest); 655 656 pp = udp_gro_receive(head, skb, uh, sk); 657 return pp; 658 659flush: 660 NAPI_GRO_CB(skb)->flush = 1; 661 return NULL; 662} 663 664static int udp_gro_complete_segment(struct sk_buff *skb) 665{ 666 struct udphdr *uh = udp_hdr(skb); 667 668 skb->csum_start = (unsigned char *)uh - skb->head; 669 skb->csum_offset = offsetof(struct udphdr, check); 670 skb->ip_summed = CHECKSUM_PARTIAL; 671 672 skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count; 673 skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_L4; 674 675 if (skb->encapsulation) 676 skb->inner_transport_header = skb->transport_header; 677 678 return 0; 679} 680 681int udp_gro_complete(struct sk_buff *skb, int nhoff, 682 udp_lookup_t lookup) 683{ 684 __be16 newlen = htons(skb->len - nhoff); 685 struct udphdr *uh = (struct udphdr *)(skb->data + nhoff); 686 struct sock *sk; 687 int err; 688 689 uh->len = newlen; 690 691 sk = INDIRECT_CALL_INET(lookup, udp6_lib_lookup_skb, 692 udp4_lib_lookup_skb, skb, uh->source, uh->dest); 693 if (sk && udp_sk(sk)->gro_complete) { 694 skb_shinfo(skb)->gso_type = uh->check ? SKB_GSO_UDP_TUNNEL_CSUM 695 : SKB_GSO_UDP_TUNNEL; 696 697 /* clear the encap mark, so that inner frag_list gro_complete 698 * can take place 699 */ 700 NAPI_GRO_CB(skb)->encap_mark = 0; 701 702 /* Set encapsulation before calling into inner gro_complete() 703 * functions to make them set up the inner offsets. 704 */ 705 skb->encapsulation = 1; 706 err = udp_sk(sk)->gro_complete(sk, skb, 707 nhoff + sizeof(struct udphdr)); 708 } else { 709 err = udp_gro_complete_segment(skb); 710 } 711 712 if (skb->remcsum_offload) 713 skb_shinfo(skb)->gso_type |= SKB_GSO_TUNNEL_REMCSUM; 714 715 return err; 716} 717EXPORT_SYMBOL(udp_gro_complete); 718 719INDIRECT_CALLABLE_SCOPE int udp4_gro_complete(struct sk_buff *skb, int nhoff) 720{ 721 const struct iphdr *iph = ip_hdr(skb); 722 struct udphdr *uh = (struct udphdr *)(skb->data + nhoff); 723 724 /* do fraglist only if there is no outer UDP encap (or we already processed it) */ 725 if (NAPI_GRO_CB(skb)->is_flist && !NAPI_GRO_CB(skb)->encap_mark) { 726 uh->len = htons(skb->len - nhoff); 727 728 skb_shinfo(skb)->gso_type |= (SKB_GSO_FRAGLIST|SKB_GSO_UDP_L4); 729 skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count; 730 731 __skb_incr_checksum_unnecessary(skb); 732 733 return 0; 734 } 735 736 if (uh->check) 737 uh->check = ~udp_v4_check(skb->len - nhoff, iph->saddr, 738 iph->daddr, 0); 739 740 return udp_gro_complete(skb, nhoff, udp4_lib_lookup_skb); 741} 742 743int __init udpv4_offload_init(void) 744{ 745 net_hotdata.udpv4_offload = (struct net_offload) { 746 .callbacks = { 747 .gso_segment = udp4_ufo_fragment, 748 .gro_receive = udp4_gro_receive, 749 .gro_complete = udp4_gro_complete, 750 }, 751 }; 752 return inet_add_offload(&net_hotdata.udpv4_offload, IPPROTO_UDP); 753} 754