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 (unlikely(skb_checksum_start(gso_skb) != 282 skb_transport_header(gso_skb))) 283 return ERR_PTR(-EINVAL); 284 285 if (skb_gso_ok(gso_skb, features | NETIF_F_GSO_ROBUST)) { 286 /* Packet is from an untrusted source, reset gso_segs. */ 287 skb_shinfo(gso_skb)->gso_segs = DIV_ROUND_UP(gso_skb->len - sizeof(*uh), 288 mss); 289 return NULL; 290 } 291 292 if (skb_shinfo(gso_skb)->gso_type & SKB_GSO_FRAGLIST) 293 return __udp_gso_segment_list(gso_skb, features, is_ipv6); 294 295 skb_pull(gso_skb, sizeof(*uh)); 296 297 /* clear destructor to avoid skb_segment assigning it to tail */ 298 copy_dtor = gso_skb->destructor == sock_wfree; 299 if (copy_dtor) 300 gso_skb->destructor = NULL; 301 302 segs = skb_segment(gso_skb, features); 303 if (IS_ERR_OR_NULL(segs)) { 304 if (copy_dtor) 305 gso_skb->destructor = sock_wfree; 306 return segs; 307 } 308 309 /* GSO partial and frag_list segmentation only requires splitting 310 * the frame into an MSS multiple and possibly a remainder, both 311 * cases return a GSO skb. So update the mss now. 312 */ 313 if (skb_is_gso(segs)) 314 mss *= skb_shinfo(segs)->gso_segs; 315 316 seg = segs; 317 uh = udp_hdr(seg); 318 319 /* preserve TX timestamp flags and TS key for first segment */ 320 skb_shinfo(seg)->tskey = skb_shinfo(gso_skb)->tskey; 321 skb_shinfo(seg)->tx_flags |= 322 (skb_shinfo(gso_skb)->tx_flags & SKBTX_ANY_TSTAMP); 323 324 /* compute checksum adjustment based on old length versus new */ 325 newlen = htons(sizeof(*uh) + mss); 326 check = csum16_add(csum16_sub(uh->check, uh->len), newlen); 327 328 for (;;) { 329 if (copy_dtor) { 330 seg->destructor = sock_wfree; 331 seg->sk = sk; 332 sum_truesize += seg->truesize; 333 } 334 335 if (!seg->next) 336 break; 337 338 uh->len = newlen; 339 uh->check = check; 340 341 if (seg->ip_summed == CHECKSUM_PARTIAL) 342 gso_reset_checksum(seg, ~check); 343 else 344 uh->check = gso_make_checksum(seg, ~check) ? : 345 CSUM_MANGLED_0; 346 347 seg = seg->next; 348 uh = udp_hdr(seg); 349 } 350 351 /* last packet can be partial gso_size, account for that in checksum */ 352 newlen = htons(skb_tail_pointer(seg) - skb_transport_header(seg) + 353 seg->data_len); 354 check = csum16_add(csum16_sub(uh->check, uh->len), newlen); 355 356 uh->len = newlen; 357 uh->check = check; 358 359 if (seg->ip_summed == CHECKSUM_PARTIAL) 360 gso_reset_checksum(seg, ~check); 361 else 362 uh->check = gso_make_checksum(seg, ~check) ? : CSUM_MANGLED_0; 363 364 /* On the TX path, CHECKSUM_NONE and CHECKSUM_UNNECESSARY have the same 365 * meaning. However, check for bad offloads in the GSO stack expects the 366 * latter, if the checksum was calculated in software. To vouch for the 367 * segment skbs we actually need to set it on the gso_skb. 368 */ 369 if (gso_skb->ip_summed == CHECKSUM_NONE) 370 gso_skb->ip_summed = CHECKSUM_UNNECESSARY; 371 372 /* update refcount for the packet */ 373 if (copy_dtor) { 374 int delta = sum_truesize - gso_skb->truesize; 375 376 /* In some pathological cases, delta can be negative. 377 * We need to either use refcount_add() or refcount_sub_and_test() 378 */ 379 if (likely(delta >= 0)) 380 refcount_add(delta, &sk->sk_wmem_alloc); 381 else 382 WARN_ON_ONCE(refcount_sub_and_test(-delta, &sk->sk_wmem_alloc)); 383 } 384 return segs; 385 } 386 EXPORT_SYMBOL_GPL(__udp_gso_segment); 387 388 static struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb, 389 netdev_features_t features) 390 { 391 struct sk_buff *segs = ERR_PTR(-EINVAL); 392 unsigned int mss; 393 __wsum csum; 394 struct udphdr *uh; 395 struct iphdr *iph; 396 397 if (skb->encapsulation && 398 (skb_shinfo(skb)->gso_type & 399 (SKB_GSO_UDP_TUNNEL|SKB_GSO_UDP_TUNNEL_CSUM))) { 400 segs = skb_udp_tunnel_segment(skb, features, false); 401 goto out; 402 } 403 404 if (!(skb_shinfo(skb)->gso_type & (SKB_GSO_UDP | SKB_GSO_UDP_L4))) 405 goto out; 406 407 if (!pskb_may_pull(skb, sizeof(struct udphdr))) 408 goto out; 409 410 if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) 411 return __udp_gso_segment(skb, features, false); 412 413 mss = skb_shinfo(skb)->gso_size; 414 if (unlikely(skb->len <= mss)) 415 goto out; 416 417 /* Do software UFO. Complete and fill in the UDP checksum as 418 * HW cannot do checksum of UDP packets sent as multiple 419 * IP fragments. 420 */ 421 422 uh = udp_hdr(skb); 423 iph = ip_hdr(skb); 424 425 uh->check = 0; 426 csum = skb_checksum(skb, 0, skb->len, 0); 427 uh->check = udp_v4_check(skb->len, iph->saddr, iph->daddr, csum); 428 if (uh->check == 0) 429 uh->check = CSUM_MANGLED_0; 430 431 skb->ip_summed = CHECKSUM_UNNECESSARY; 432 433 /* If there is no outer header we can fake a checksum offload 434 * due to the fact that we have already done the checksum in 435 * software prior to segmenting the frame. 436 */ 437 if (!skb->encap_hdr_csum) 438 features |= NETIF_F_HW_CSUM; 439 440 /* Fragment the skb. IP headers of the fragments are updated in 441 * inet_gso_segment() 442 */ 443 segs = skb_segment(skb, features); 444 out: 445 return segs; 446 } 447 448 449 #define UDP_GRO_CNT_MAX 64 450 static struct sk_buff *udp_gro_receive_segment(struct list_head *head, 451 struct sk_buff *skb) 452 { 453 struct udphdr *uh = udp_gro_udphdr(skb); 454 struct sk_buff *pp = NULL; 455 struct udphdr *uh2; 456 struct sk_buff *p; 457 unsigned int ulen; 458 int ret = 0; 459 int flush; 460 461 /* requires non zero csum, for symmetry with GSO */ 462 if (!uh->check) { 463 NAPI_GRO_CB(skb)->flush = 1; 464 return NULL; 465 } 466 467 /* Do not deal with padded or malicious packets, sorry ! */ 468 ulen = ntohs(uh->len); 469 if (ulen <= sizeof(*uh) || ulen != skb_gro_len(skb)) { 470 NAPI_GRO_CB(skb)->flush = 1; 471 return NULL; 472 } 473 /* pull encapsulating udp header */ 474 skb_gro_pull(skb, sizeof(struct udphdr)); 475 476 list_for_each_entry(p, head, list) { 477 if (!NAPI_GRO_CB(p)->same_flow) 478 continue; 479 480 uh2 = udp_hdr(p); 481 482 /* Match ports only, as csum is always non zero */ 483 if ((*(u32 *)&uh->source != *(u32 *)&uh2->source)) { 484 NAPI_GRO_CB(p)->same_flow = 0; 485 continue; 486 } 487 488 if (NAPI_GRO_CB(skb)->is_flist != NAPI_GRO_CB(p)->is_flist) { 489 NAPI_GRO_CB(skb)->flush = 1; 490 return p; 491 } 492 493 flush = gro_receive_network_flush(uh, uh2, p); 494 495 /* Terminate the flow on len mismatch or if it grow "too much". 496 * Under small packet flood GRO count could elsewhere grow a lot 497 * leading to excessive truesize values. 498 * On len mismatch merge the first packet shorter than gso_size, 499 * otherwise complete the GRO packet. 500 */ 501 if (ulen > ntohs(uh2->len) || flush) { 502 pp = p; 503 } else { 504 if (NAPI_GRO_CB(skb)->is_flist) { 505 if (!pskb_may_pull(skb, skb_gro_offset(skb))) { 506 NAPI_GRO_CB(skb)->flush = 1; 507 return NULL; 508 } 509 if ((skb->ip_summed != p->ip_summed) || 510 (skb->csum_level != p->csum_level)) { 511 NAPI_GRO_CB(skb)->flush = 1; 512 return NULL; 513 } 514 ret = skb_gro_receive_list(p, skb); 515 } else { 516 skb_gro_postpull_rcsum(skb, uh, 517 sizeof(struct udphdr)); 518 519 ret = skb_gro_receive(p, skb); 520 } 521 } 522 523 if (ret || ulen != ntohs(uh2->len) || 524 NAPI_GRO_CB(p)->count >= UDP_GRO_CNT_MAX) 525 pp = p; 526 527 return pp; 528 } 529 530 /* mismatch, but we never need to flush */ 531 return NULL; 532 } 533 534 struct sk_buff *udp_gro_receive(struct list_head *head, struct sk_buff *skb, 535 struct udphdr *uh, struct sock *sk) 536 { 537 struct sk_buff *pp = NULL; 538 struct sk_buff *p; 539 struct udphdr *uh2; 540 unsigned int off = skb_gro_offset(skb); 541 int flush = 1; 542 543 /* We can do L4 aggregation only if the packet can't land in a tunnel 544 * otherwise we could corrupt the inner stream. Detecting such packets 545 * cannot be foolproof and the aggregation might still happen in some 546 * cases. Such packets should be caught in udp_unexpected_gso later. 547 */ 548 NAPI_GRO_CB(skb)->is_flist = 0; 549 if (!sk || !udp_sk(sk)->gro_receive) { 550 /* If the packet was locally encapsulated in a UDP tunnel that 551 * wasn't detected above, do not GRO. 552 */ 553 if (skb->encapsulation) 554 goto out; 555 556 if (skb->dev->features & NETIF_F_GRO_FRAGLIST) 557 NAPI_GRO_CB(skb)->is_flist = sk ? !udp_test_bit(GRO_ENABLED, sk) : 1; 558 559 if ((!sk && (skb->dev->features & NETIF_F_GRO_UDP_FWD)) || 560 (sk && udp_test_bit(GRO_ENABLED, sk)) || NAPI_GRO_CB(skb)->is_flist) 561 return call_gro_receive(udp_gro_receive_segment, head, skb); 562 563 /* no GRO, be sure flush the current packet */ 564 goto out; 565 } 566 567 if (NAPI_GRO_CB(skb)->encap_mark || 568 (uh->check && skb->ip_summed != CHECKSUM_PARTIAL && 569 NAPI_GRO_CB(skb)->csum_cnt == 0 && 570 !NAPI_GRO_CB(skb)->csum_valid)) 571 goto out; 572 573 /* mark that this skb passed once through the tunnel gro layer */ 574 NAPI_GRO_CB(skb)->encap_mark = 1; 575 576 flush = 0; 577 578 list_for_each_entry(p, head, list) { 579 if (!NAPI_GRO_CB(p)->same_flow) 580 continue; 581 582 uh2 = (struct udphdr *)(p->data + off); 583 584 /* Match ports and either checksums are either both zero 585 * or nonzero. 586 */ 587 if ((*(u32 *)&uh->source != *(u32 *)&uh2->source) || 588 (!uh->check ^ !uh2->check)) { 589 NAPI_GRO_CB(p)->same_flow = 0; 590 continue; 591 } 592 } 593 594 skb_gro_pull(skb, sizeof(struct udphdr)); /* pull encapsulating udp header */ 595 skb_gro_postpull_rcsum(skb, uh, sizeof(struct udphdr)); 596 pp = call_gro_receive_sk(udp_sk(sk)->gro_receive, sk, head, skb); 597 598 out: 599 skb_gro_flush_final(skb, pp, flush); 600 return pp; 601 } 602 EXPORT_SYMBOL(udp_gro_receive); 603 604 static struct sock *udp4_gro_lookup_skb(struct sk_buff *skb, __be16 sport, 605 __be16 dport) 606 { 607 const struct iphdr *iph = skb_gro_network_header(skb); 608 struct net *net = dev_net(skb->dev); 609 int iif, sdif; 610 611 inet_get_iif_sdif(skb, &iif, &sdif); 612 613 return __udp4_lib_lookup(net, iph->saddr, sport, 614 iph->daddr, dport, iif, 615 sdif, net->ipv4.udp_table, NULL); 616 } 617 618 INDIRECT_CALLABLE_SCOPE 619 struct sk_buff *udp4_gro_receive(struct list_head *head, struct sk_buff *skb) 620 { 621 struct udphdr *uh = udp_gro_udphdr(skb); 622 struct sock *sk = NULL; 623 struct sk_buff *pp; 624 625 if (unlikely(!uh)) 626 goto flush; 627 628 /* Don't bother verifying checksum if we're going to flush anyway. */ 629 if (NAPI_GRO_CB(skb)->flush) 630 goto skip; 631 632 if (skb_gro_checksum_validate_zero_check(skb, IPPROTO_UDP, uh->check, 633 inet_gro_compute_pseudo)) 634 goto flush; 635 else if (uh->check) 636 skb_gro_checksum_try_convert(skb, IPPROTO_UDP, 637 inet_gro_compute_pseudo); 638 skip: 639 NAPI_GRO_CB(skb)->is_ipv6 = 0; 640 641 if (static_branch_unlikely(&udp_encap_needed_key)) 642 sk = udp4_gro_lookup_skb(skb, uh->source, uh->dest); 643 644 pp = udp_gro_receive(head, skb, uh, sk); 645 return pp; 646 647 flush: 648 NAPI_GRO_CB(skb)->flush = 1; 649 return NULL; 650 } 651 652 static int udp_gro_complete_segment(struct sk_buff *skb) 653 { 654 struct udphdr *uh = udp_hdr(skb); 655 656 skb->csum_start = (unsigned char *)uh - skb->head; 657 skb->csum_offset = offsetof(struct udphdr, check); 658 skb->ip_summed = CHECKSUM_PARTIAL; 659 660 skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count; 661 skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_L4; 662 663 if (skb->encapsulation) 664 skb->inner_transport_header = skb->transport_header; 665 666 return 0; 667 } 668 669 int udp_gro_complete(struct sk_buff *skb, int nhoff, 670 udp_lookup_t lookup) 671 { 672 __be16 newlen = htons(skb->len - nhoff); 673 struct udphdr *uh = (struct udphdr *)(skb->data + nhoff); 674 struct sock *sk; 675 int err; 676 677 uh->len = newlen; 678 679 sk = INDIRECT_CALL_INET(lookup, udp6_lib_lookup_skb, 680 udp4_lib_lookup_skb, skb, uh->source, uh->dest); 681 if (sk && udp_sk(sk)->gro_complete) { 682 skb_shinfo(skb)->gso_type = uh->check ? SKB_GSO_UDP_TUNNEL_CSUM 683 : SKB_GSO_UDP_TUNNEL; 684 685 /* clear the encap mark, so that inner frag_list gro_complete 686 * can take place 687 */ 688 NAPI_GRO_CB(skb)->encap_mark = 0; 689 690 /* Set encapsulation before calling into inner gro_complete() 691 * functions to make them set up the inner offsets. 692 */ 693 skb->encapsulation = 1; 694 err = udp_sk(sk)->gro_complete(sk, skb, 695 nhoff + sizeof(struct udphdr)); 696 } else { 697 err = udp_gro_complete_segment(skb); 698 } 699 700 if (skb->remcsum_offload) 701 skb_shinfo(skb)->gso_type |= SKB_GSO_TUNNEL_REMCSUM; 702 703 return err; 704 } 705 EXPORT_SYMBOL(udp_gro_complete); 706 707 INDIRECT_CALLABLE_SCOPE int udp4_gro_complete(struct sk_buff *skb, int nhoff) 708 { 709 const u16 offset = NAPI_GRO_CB(skb)->network_offsets[skb->encapsulation]; 710 const struct iphdr *iph = (struct iphdr *)(skb->data + offset); 711 struct udphdr *uh = (struct udphdr *)(skb->data + nhoff); 712 713 /* do fraglist only if there is no outer UDP encap (or we already processed it) */ 714 if (NAPI_GRO_CB(skb)->is_flist && !NAPI_GRO_CB(skb)->encap_mark) { 715 uh->len = htons(skb->len - nhoff); 716 717 skb_shinfo(skb)->gso_type |= (SKB_GSO_FRAGLIST|SKB_GSO_UDP_L4); 718 skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count; 719 720 __skb_incr_checksum_unnecessary(skb); 721 722 return 0; 723 } 724 725 if (uh->check) 726 uh->check = ~udp_v4_check(skb->len - nhoff, iph->saddr, 727 iph->daddr, 0); 728 729 return udp_gro_complete(skb, nhoff, udp4_lib_lookup_skb); 730 } 731 732 int __init udpv4_offload_init(void) 733 { 734 net_hotdata.udpv4_offload = (struct net_offload) { 735 .callbacks = { 736 .gso_segment = udp4_ufo_fragment, 737 .gro_receive = udp4_gro_receive, 738 .gro_complete = udp4_gro_complete, 739 }, 740 }; 741 return inet_add_offload(&net_hotdata.udpv4_offload, IPPROTO_UDP); 742 } 743