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 /* We don't know if egress device can segment and checksum the packet 286 * when IPv6 extension headers are present. Fall back to software GSO. 287 */ 288 if (gso_skb->ip_summed != CHECKSUM_PARTIAL) 289 features &= ~(NETIF_F_GSO_UDP_L4 | NETIF_F_CSUM_MASK); 290 291 if (skb_gso_ok(gso_skb, features | NETIF_F_GSO_ROBUST)) { 292 /* Packet is from an untrusted source, reset gso_segs. */ 293 skb_shinfo(gso_skb)->gso_segs = DIV_ROUND_UP(gso_skb->len - sizeof(*uh), 294 mss); 295 return NULL; 296 } 297 298 if (skb_shinfo(gso_skb)->gso_type & SKB_GSO_FRAGLIST) 299 return __udp_gso_segment_list(gso_skb, features, is_ipv6); 300 301 skb_pull(gso_skb, sizeof(*uh)); 302 303 /* clear destructor to avoid skb_segment assigning it to tail */ 304 copy_dtor = gso_skb->destructor == sock_wfree; 305 if (copy_dtor) 306 gso_skb->destructor = NULL; 307 308 segs = skb_segment(gso_skb, features); 309 if (IS_ERR_OR_NULL(segs)) { 310 if (copy_dtor) 311 gso_skb->destructor = sock_wfree; 312 return segs; 313 } 314 315 /* GSO partial and frag_list segmentation only requires splitting 316 * the frame into an MSS multiple and possibly a remainder, both 317 * cases return a GSO skb. So update the mss now. 318 */ 319 if (skb_is_gso(segs)) 320 mss *= skb_shinfo(segs)->gso_segs; 321 322 seg = segs; 323 uh = udp_hdr(seg); 324 325 /* preserve TX timestamp flags and TS key for first segment */ 326 skb_shinfo(seg)->tskey = skb_shinfo(gso_skb)->tskey; 327 skb_shinfo(seg)->tx_flags |= 328 (skb_shinfo(gso_skb)->tx_flags & SKBTX_ANY_TSTAMP); 329 330 /* compute checksum adjustment based on old length versus new */ 331 newlen = htons(sizeof(*uh) + mss); 332 check = csum16_add(csum16_sub(uh->check, uh->len), newlen); 333 334 for (;;) { 335 if (copy_dtor) { 336 seg->destructor = sock_wfree; 337 seg->sk = sk; 338 sum_truesize += seg->truesize; 339 } 340 341 if (!seg->next) 342 break; 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) ? : 351 CSUM_MANGLED_0; 352 353 seg = seg->next; 354 uh = udp_hdr(seg); 355 } 356 357 /* last packet can be partial gso_size, account for that in checksum */ 358 newlen = htons(skb_tail_pointer(seg) - skb_transport_header(seg) + 359 seg->data_len); 360 check = csum16_add(csum16_sub(uh->check, uh->len), newlen); 361 362 uh->len = newlen; 363 uh->check = check; 364 365 if (seg->ip_summed == CHECKSUM_PARTIAL) 366 gso_reset_checksum(seg, ~check); 367 else 368 uh->check = gso_make_checksum(seg, ~check) ? : CSUM_MANGLED_0; 369 370 /* On the TX path, CHECKSUM_NONE and CHECKSUM_UNNECESSARY have the same 371 * meaning. However, check for bad offloads in the GSO stack expects the 372 * latter, if the checksum was calculated in software. To vouch for the 373 * segment skbs we actually need to set it on the gso_skb. 374 */ 375 if (gso_skb->ip_summed == CHECKSUM_NONE) 376 gso_skb->ip_summed = CHECKSUM_UNNECESSARY; 377 378 /* update refcount for the packet */ 379 if (copy_dtor) { 380 int delta = sum_truesize - gso_skb->truesize; 381 382 /* In some pathological cases, delta can be negative. 383 * We need to either use refcount_add() or refcount_sub_and_test() 384 */ 385 if (likely(delta >= 0)) 386 refcount_add(delta, &sk->sk_wmem_alloc); 387 else 388 WARN_ON_ONCE(refcount_sub_and_test(-delta, &sk->sk_wmem_alloc)); 389 } 390 return segs; 391 } 392 EXPORT_SYMBOL_GPL(__udp_gso_segment); 393 394 static struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb, 395 netdev_features_t features) 396 { 397 struct sk_buff *segs = ERR_PTR(-EINVAL); 398 unsigned int mss; 399 __wsum csum; 400 struct udphdr *uh; 401 struct iphdr *iph; 402 403 if (skb->encapsulation && 404 (skb_shinfo(skb)->gso_type & 405 (SKB_GSO_UDP_TUNNEL|SKB_GSO_UDP_TUNNEL_CSUM))) { 406 segs = skb_udp_tunnel_segment(skb, features, false); 407 goto out; 408 } 409 410 if (!(skb_shinfo(skb)->gso_type & (SKB_GSO_UDP | SKB_GSO_UDP_L4))) 411 goto out; 412 413 if (!pskb_may_pull(skb, sizeof(struct udphdr))) 414 goto out; 415 416 if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) 417 return __udp_gso_segment(skb, features, false); 418 419 mss = skb_shinfo(skb)->gso_size; 420 if (unlikely(skb->len <= mss)) 421 goto out; 422 423 /* Do software UFO. Complete and fill in the UDP checksum as 424 * HW cannot do checksum of UDP packets sent as multiple 425 * IP fragments. 426 */ 427 428 uh = udp_hdr(skb); 429 iph = ip_hdr(skb); 430 431 uh->check = 0; 432 csum = skb_checksum(skb, 0, skb->len, 0); 433 uh->check = udp_v4_check(skb->len, iph->saddr, iph->daddr, csum); 434 if (uh->check == 0) 435 uh->check = CSUM_MANGLED_0; 436 437 skb->ip_summed = CHECKSUM_UNNECESSARY; 438 439 /* If there is no outer header we can fake a checksum offload 440 * due to the fact that we have already done the checksum in 441 * software prior to segmenting the frame. 442 */ 443 if (!skb->encap_hdr_csum) 444 features |= NETIF_F_HW_CSUM; 445 446 /* Fragment the skb. IP headers of the fragments are updated in 447 * inet_gso_segment() 448 */ 449 segs = skb_segment(skb, features); 450 out: 451 return segs; 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 int flush; 466 467 /* requires non zero csum, for symmetry with GSO */ 468 if (!uh->check) { 469 NAPI_GRO_CB(skb)->flush = 1; 470 return NULL; 471 } 472 473 /* Do not deal with padded or malicious packets, sorry ! */ 474 ulen = ntohs(uh->len); 475 if (ulen <= sizeof(*uh) || ulen != skb_gro_len(skb)) { 476 NAPI_GRO_CB(skb)->flush = 1; 477 return NULL; 478 } 479 /* pull encapsulating udp header */ 480 skb_gro_pull(skb, sizeof(struct udphdr)); 481 482 list_for_each_entry(p, head, list) { 483 if (!NAPI_GRO_CB(p)->same_flow) 484 continue; 485 486 uh2 = udp_hdr(p); 487 488 /* Match ports only, as csum is always non zero */ 489 if ((*(u32 *)&uh->source != *(u32 *)&uh2->source)) { 490 NAPI_GRO_CB(p)->same_flow = 0; 491 continue; 492 } 493 494 if (NAPI_GRO_CB(skb)->is_flist != NAPI_GRO_CB(p)->is_flist) { 495 NAPI_GRO_CB(skb)->flush = 1; 496 return p; 497 } 498 499 flush = gro_receive_network_flush(uh, uh2, p); 500 501 /* Terminate the flow on len mismatch or if it grow "too much". 502 * Under small packet flood GRO count could elsewhere grow a lot 503 * leading to excessive truesize values. 504 * On len mismatch merge the first packet shorter than gso_size, 505 * otherwise complete the GRO packet. 506 */ 507 if (ulen > ntohs(uh2->len) || flush) { 508 pp = p; 509 } else { 510 if (NAPI_GRO_CB(skb)->is_flist) { 511 if (!pskb_may_pull(skb, skb_gro_offset(skb))) { 512 NAPI_GRO_CB(skb)->flush = 1; 513 return NULL; 514 } 515 if ((skb->ip_summed != p->ip_summed) || 516 (skb->csum_level != p->csum_level)) { 517 NAPI_GRO_CB(skb)->flush = 1; 518 return NULL; 519 } 520 ret = skb_gro_receive_list(p, skb); 521 } else { 522 skb_gro_postpull_rcsum(skb, uh, 523 sizeof(struct udphdr)); 524 525 ret = skb_gro_receive(p, skb); 526 } 527 } 528 529 if (ret || ulen != ntohs(uh2->len) || 530 NAPI_GRO_CB(p)->count >= UDP_GRO_CNT_MAX) 531 pp = p; 532 533 return pp; 534 } 535 536 /* mismatch, but we never need to flush */ 537 return NULL; 538 } 539 540 struct sk_buff *udp_gro_receive(struct list_head *head, struct sk_buff *skb, 541 struct udphdr *uh, struct sock *sk) 542 { 543 struct sk_buff *pp = NULL; 544 struct sk_buff *p; 545 struct udphdr *uh2; 546 unsigned int off = skb_gro_offset(skb); 547 int flush = 1; 548 549 /* We can do L4 aggregation only if the packet can't land in a tunnel 550 * otherwise we could corrupt the inner stream. Detecting such packets 551 * cannot be foolproof and the aggregation might still happen in some 552 * cases. Such packets should be caught in udp_unexpected_gso later. 553 */ 554 NAPI_GRO_CB(skb)->is_flist = 0; 555 if (!sk || !udp_sk(sk)->gro_receive) { 556 /* If the packet was locally encapsulated in a UDP tunnel that 557 * wasn't detected above, do not GRO. 558 */ 559 if (skb->encapsulation) 560 goto out; 561 562 if (skb->dev->features & NETIF_F_GRO_FRAGLIST) 563 NAPI_GRO_CB(skb)->is_flist = sk ? !udp_test_bit(GRO_ENABLED, sk) : 1; 564 565 if ((!sk && (skb->dev->features & NETIF_F_GRO_UDP_FWD)) || 566 (sk && udp_test_bit(GRO_ENABLED, sk)) || NAPI_GRO_CB(skb)->is_flist) 567 return call_gro_receive(udp_gro_receive_segment, head, skb); 568 569 /* no GRO, be sure flush the current packet */ 570 goto out; 571 } 572 573 if (NAPI_GRO_CB(skb)->encap_mark || 574 (uh->check && skb->ip_summed != CHECKSUM_PARTIAL && 575 NAPI_GRO_CB(skb)->csum_cnt == 0 && 576 !NAPI_GRO_CB(skb)->csum_valid)) 577 goto out; 578 579 /* mark that this skb passed once through the tunnel gro layer */ 580 NAPI_GRO_CB(skb)->encap_mark = 1; 581 582 flush = 0; 583 584 list_for_each_entry(p, head, list) { 585 if (!NAPI_GRO_CB(p)->same_flow) 586 continue; 587 588 uh2 = (struct udphdr *)(p->data + off); 589 590 /* Match ports and either checksums are either both zero 591 * or nonzero. 592 */ 593 if ((*(u32 *)&uh->source != *(u32 *)&uh2->source) || 594 (!uh->check ^ !uh2->check)) { 595 NAPI_GRO_CB(p)->same_flow = 0; 596 continue; 597 } 598 } 599 600 skb_gro_pull(skb, sizeof(struct udphdr)); /* pull encapsulating udp header */ 601 skb_gro_postpull_rcsum(skb, uh, sizeof(struct udphdr)); 602 pp = call_gro_receive_sk(udp_sk(sk)->gro_receive, sk, head, skb); 603 604 out: 605 skb_gro_flush_final(skb, pp, flush); 606 return pp; 607 } 608 EXPORT_SYMBOL(udp_gro_receive); 609 610 static struct sock *udp4_gro_lookup_skb(struct sk_buff *skb, __be16 sport, 611 __be16 dport) 612 { 613 const struct iphdr *iph = skb_gro_network_header(skb); 614 struct net *net = dev_net(skb->dev); 615 int iif, sdif; 616 617 inet_get_iif_sdif(skb, &iif, &sdif); 618 619 return __udp4_lib_lookup(net, iph->saddr, sport, 620 iph->daddr, dport, iif, 621 sdif, net->ipv4.udp_table, NULL); 622 } 623 624 INDIRECT_CALLABLE_SCOPE 625 struct sk_buff *udp4_gro_receive(struct list_head *head, struct sk_buff *skb) 626 { 627 struct udphdr *uh = udp_gro_udphdr(skb); 628 struct sock *sk = NULL; 629 struct sk_buff *pp; 630 631 if (unlikely(!uh)) 632 goto flush; 633 634 /* Don't bother verifying checksum if we're going to flush anyway. */ 635 if (NAPI_GRO_CB(skb)->flush) 636 goto skip; 637 638 if (skb_gro_checksum_validate_zero_check(skb, IPPROTO_UDP, uh->check, 639 inet_gro_compute_pseudo)) 640 goto flush; 641 else if (uh->check) 642 skb_gro_checksum_try_convert(skb, IPPROTO_UDP, 643 inet_gro_compute_pseudo); 644 skip: 645 NAPI_GRO_CB(skb)->is_ipv6 = 0; 646 647 if (static_branch_unlikely(&udp_encap_needed_key)) 648 sk = udp4_gro_lookup_skb(skb, uh->source, uh->dest); 649 650 pp = udp_gro_receive(head, skb, uh, sk); 651 return pp; 652 653 flush: 654 NAPI_GRO_CB(skb)->flush = 1; 655 return NULL; 656 } 657 658 static int udp_gro_complete_segment(struct sk_buff *skb) 659 { 660 struct udphdr *uh = udp_hdr(skb); 661 662 skb->csum_start = (unsigned char *)uh - skb->head; 663 skb->csum_offset = offsetof(struct udphdr, check); 664 skb->ip_summed = CHECKSUM_PARTIAL; 665 666 skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count; 667 skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_L4; 668 669 if (skb->encapsulation) 670 skb->inner_transport_header = skb->transport_header; 671 672 return 0; 673 } 674 675 int udp_gro_complete(struct sk_buff *skb, int nhoff, 676 udp_lookup_t lookup) 677 { 678 __be16 newlen = htons(skb->len - nhoff); 679 struct udphdr *uh = (struct udphdr *)(skb->data + nhoff); 680 struct sock *sk; 681 int err; 682 683 uh->len = newlen; 684 685 sk = INDIRECT_CALL_INET(lookup, udp6_lib_lookup_skb, 686 udp4_lib_lookup_skb, skb, uh->source, uh->dest); 687 if (sk && udp_sk(sk)->gro_complete) { 688 skb_shinfo(skb)->gso_type = uh->check ? SKB_GSO_UDP_TUNNEL_CSUM 689 : SKB_GSO_UDP_TUNNEL; 690 691 /* clear the encap mark, so that inner frag_list gro_complete 692 * can take place 693 */ 694 NAPI_GRO_CB(skb)->encap_mark = 0; 695 696 /* Set encapsulation before calling into inner gro_complete() 697 * functions to make them set up the inner offsets. 698 */ 699 skb->encapsulation = 1; 700 err = udp_sk(sk)->gro_complete(sk, skb, 701 nhoff + sizeof(struct udphdr)); 702 } else { 703 err = udp_gro_complete_segment(skb); 704 } 705 706 if (skb->remcsum_offload) 707 skb_shinfo(skb)->gso_type |= SKB_GSO_TUNNEL_REMCSUM; 708 709 return err; 710 } 711 EXPORT_SYMBOL(udp_gro_complete); 712 713 INDIRECT_CALLABLE_SCOPE int udp4_gro_complete(struct sk_buff *skb, int nhoff) 714 { 715 const u16 offset = NAPI_GRO_CB(skb)->network_offsets[skb->encapsulation]; 716 const struct iphdr *iph = (struct iphdr *)(skb->data + offset); 717 struct udphdr *uh = (struct udphdr *)(skb->data + nhoff); 718 719 /* do fraglist only if there is no outer UDP encap (or we already processed it) */ 720 if (NAPI_GRO_CB(skb)->is_flist && !NAPI_GRO_CB(skb)->encap_mark) { 721 uh->len = htons(skb->len - nhoff); 722 723 skb_shinfo(skb)->gso_type |= (SKB_GSO_FRAGLIST|SKB_GSO_UDP_L4); 724 skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count; 725 726 __skb_incr_checksum_unnecessary(skb); 727 728 return 0; 729 } 730 731 if (uh->check) 732 uh->check = ~udp_v4_check(skb->len - nhoff, iph->saddr, 733 iph->daddr, 0); 734 735 return udp_gro_complete(skb, nhoff, udp4_lib_lookup_skb); 736 } 737 738 int __init udpv4_offload_init(void) 739 { 740 net_hotdata.udpv4_offload = (struct net_offload) { 741 .callbacks = { 742 .gso_segment = udp4_ufo_fragment, 743 .gro_receive = udp4_gro_receive, 744 .gro_complete = udp4_gro_complete, 745 }, 746 }; 747 return inet_add_offload(&net_hotdata.udpv4_offload, IPPROTO_UDP); 748 } 749