1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * IPv6 output functions 4 * Linux INET6 implementation 5 * 6 * Authors: 7 * Pedro Roque <roque@di.fc.ul.pt> 8 * 9 * Based on linux/net/ipv4/ip_output.c 10 * 11 * Changes: 12 * A.N.Kuznetsov : airthmetics in fragmentation. 13 * extension headers are implemented. 14 * route changes now work. 15 * ip6_forward does not confuse sniffers. 16 * etc. 17 * 18 * H. von Brand : Added missing #include <linux/string.h> 19 * Imran Patel : frag id should be in NBO 20 * Kazunori MIYAZAWA @USAGI 21 * : add ip6_append_data and related functions 22 * for datagram xmit 23 */ 24 25 #include <linux/errno.h> 26 #include <linux/kernel.h> 27 #include <linux/string.h> 28 #include <linux/socket.h> 29 #include <linux/net.h> 30 #include <linux/netdevice.h> 31 #include <linux/if_arp.h> 32 #include <linux/in6.h> 33 #include <linux/tcp.h> 34 #include <linux/route.h> 35 #include <linux/module.h> 36 #include <linux/slab.h> 37 38 #include <linux/bpf-cgroup.h> 39 #include <linux/netfilter.h> 40 #include <linux/netfilter_ipv6.h> 41 42 #include <net/sock.h> 43 #include <net/snmp.h> 44 45 #include <net/ipv6.h> 46 #include <net/ndisc.h> 47 #include <net/protocol.h> 48 #include <net/ip6_route.h> 49 #include <net/addrconf.h> 50 #include <net/rawv6.h> 51 #include <net/icmp.h> 52 #include <net/xfrm.h> 53 #include <net/checksum.h> 54 #include <linux/mroute6.h> 55 #include <net/l3mdev.h> 56 #include <net/lwtunnel.h> 57 #include <net/ip_tunnels.h> 58 59 static int ip6_finish_output2(struct net *net, struct sock *sk, struct sk_buff *skb) 60 { 61 struct dst_entry *dst = skb_dst(skb); 62 struct net_device *dev = dst->dev; 63 const struct in6_addr *nexthop; 64 struct neighbour *neigh; 65 int ret; 66 67 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) { 68 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); 69 70 if (!(dev->flags & IFF_LOOPBACK) && sk_mc_loop(sk) && 71 ((mroute6_is_socket(net, skb) && 72 !(IP6CB(skb)->flags & IP6SKB_FORWARDED)) || 73 ipv6_chk_mcast_addr(dev, &ipv6_hdr(skb)->daddr, 74 &ipv6_hdr(skb)->saddr))) { 75 struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); 76 77 /* Do not check for IFF_ALLMULTI; multicast routing 78 is not supported in any case. 79 */ 80 if (newskb) 81 NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING, 82 net, sk, newskb, NULL, newskb->dev, 83 dev_loopback_xmit); 84 85 if (ipv6_hdr(skb)->hop_limit == 0) { 86 IP6_INC_STATS(net, idev, 87 IPSTATS_MIB_OUTDISCARDS); 88 kfree_skb(skb); 89 return 0; 90 } 91 } 92 93 IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUTMCAST, skb->len); 94 95 if (IPV6_ADDR_MC_SCOPE(&ipv6_hdr(skb)->daddr) <= 96 IPV6_ADDR_SCOPE_NODELOCAL && 97 !(dev->flags & IFF_LOOPBACK)) { 98 kfree_skb(skb); 99 return 0; 100 } 101 } 102 103 if (lwtunnel_xmit_redirect(dst->lwtstate)) { 104 int res = lwtunnel_xmit(skb); 105 106 if (res < 0 || res == LWTUNNEL_XMIT_DONE) 107 return res; 108 } 109 110 rcu_read_lock_bh(); 111 nexthop = rt6_nexthop((struct rt6_info *)dst, &ipv6_hdr(skb)->daddr); 112 neigh = __ipv6_neigh_lookup_noref(dst->dev, nexthop); 113 if (unlikely(!neigh)) 114 neigh = __neigh_create(&nd_tbl, nexthop, dst->dev, false); 115 if (!IS_ERR(neigh)) { 116 sock_confirm_neigh(skb, neigh); 117 ret = neigh_output(neigh, skb, false); 118 rcu_read_unlock_bh(); 119 return ret; 120 } 121 rcu_read_unlock_bh(); 122 123 IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES); 124 kfree_skb(skb); 125 return -EINVAL; 126 } 127 128 static int __ip6_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb) 129 { 130 #if defined(CONFIG_NETFILTER) && defined(CONFIG_XFRM) 131 /* Policy lookup after SNAT yielded a new policy */ 132 if (skb_dst(skb)->xfrm) { 133 IPCB(skb)->flags |= IPSKB_REROUTED; 134 return dst_output(net, sk, skb); 135 } 136 #endif 137 138 if ((skb->len > ip6_skb_dst_mtu(skb) && !skb_is_gso(skb)) || 139 dst_allfrag(skb_dst(skb)) || 140 (IP6CB(skb)->frag_max_size && skb->len > IP6CB(skb)->frag_max_size)) 141 return ip6_fragment(net, sk, skb, ip6_finish_output2); 142 else 143 return ip6_finish_output2(net, sk, skb); 144 } 145 146 static int ip6_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb) 147 { 148 int ret; 149 150 ret = BPF_CGROUP_RUN_PROG_INET_EGRESS(sk, skb); 151 switch (ret) { 152 case NET_XMIT_SUCCESS: 153 return __ip6_finish_output(net, sk, skb); 154 case NET_XMIT_CN: 155 return __ip6_finish_output(net, sk, skb) ? : ret; 156 default: 157 kfree_skb(skb); 158 return ret; 159 } 160 } 161 162 int ip6_output(struct net *net, struct sock *sk, struct sk_buff *skb) 163 { 164 struct net_device *dev = skb_dst(skb)->dev, *indev = skb->dev; 165 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); 166 167 skb->protocol = htons(ETH_P_IPV6); 168 skb->dev = dev; 169 170 if (unlikely(idev->cnf.disable_ipv6)) { 171 IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTDISCARDS); 172 kfree_skb(skb); 173 return 0; 174 } 175 176 return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING, 177 net, sk, skb, indev, dev, 178 ip6_finish_output, 179 !(IP6CB(skb)->flags & IP6SKB_REROUTED)); 180 } 181 182 bool ip6_autoflowlabel(struct net *net, const struct ipv6_pinfo *np) 183 { 184 if (!np->autoflowlabel_set) 185 return ip6_default_np_autolabel(net); 186 else 187 return np->autoflowlabel; 188 } 189 190 /* 191 * xmit an sk_buff (used by TCP, SCTP and DCCP) 192 * Note : socket lock is not held for SYNACK packets, but might be modified 193 * by calls to skb_set_owner_w() and ipv6_local_error(), 194 * which are using proper atomic operations or spinlocks. 195 */ 196 int ip6_xmit(const struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6, 197 __u32 mark, struct ipv6_txoptions *opt, int tclass, u32 priority) 198 { 199 struct net *net = sock_net(sk); 200 const struct ipv6_pinfo *np = inet6_sk(sk); 201 struct in6_addr *first_hop = &fl6->daddr; 202 struct dst_entry *dst = skb_dst(skb); 203 unsigned int head_room; 204 struct ipv6hdr *hdr; 205 u8 proto = fl6->flowi6_proto; 206 int seg_len = skb->len; 207 int hlimit = -1; 208 u32 mtu; 209 210 head_room = sizeof(struct ipv6hdr) + LL_RESERVED_SPACE(dst->dev); 211 if (opt) 212 head_room += opt->opt_nflen + opt->opt_flen; 213 214 if (unlikely(skb_headroom(skb) < head_room)) { 215 struct sk_buff *skb2 = skb_realloc_headroom(skb, head_room); 216 if (!skb2) { 217 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 218 IPSTATS_MIB_OUTDISCARDS); 219 kfree_skb(skb); 220 return -ENOBUFS; 221 } 222 if (skb->sk) 223 skb_set_owner_w(skb2, skb->sk); 224 consume_skb(skb); 225 skb = skb2; 226 } 227 228 if (opt) { 229 seg_len += opt->opt_nflen + opt->opt_flen; 230 231 if (opt->opt_flen) 232 ipv6_push_frag_opts(skb, opt, &proto); 233 234 if (opt->opt_nflen) 235 ipv6_push_nfrag_opts(skb, opt, &proto, &first_hop, 236 &fl6->saddr); 237 } 238 239 skb_push(skb, sizeof(struct ipv6hdr)); 240 skb_reset_network_header(skb); 241 hdr = ipv6_hdr(skb); 242 243 /* 244 * Fill in the IPv6 header 245 */ 246 if (np) 247 hlimit = np->hop_limit; 248 if (hlimit < 0) 249 hlimit = ip6_dst_hoplimit(dst); 250 251 ip6_flow_hdr(hdr, tclass, ip6_make_flowlabel(net, skb, fl6->flowlabel, 252 ip6_autoflowlabel(net, np), fl6)); 253 254 hdr->payload_len = htons(seg_len); 255 hdr->nexthdr = proto; 256 hdr->hop_limit = hlimit; 257 258 hdr->saddr = fl6->saddr; 259 hdr->daddr = *first_hop; 260 261 skb->protocol = htons(ETH_P_IPV6); 262 skb->priority = priority; 263 skb->mark = mark; 264 265 mtu = dst_mtu(dst); 266 if ((skb->len <= mtu) || skb->ignore_df || skb_is_gso(skb)) { 267 IP6_UPD_PO_STATS(net, ip6_dst_idev(skb_dst(skb)), 268 IPSTATS_MIB_OUT, skb->len); 269 270 /* if egress device is enslaved to an L3 master device pass the 271 * skb to its handler for processing 272 */ 273 skb = l3mdev_ip6_out((struct sock *)sk, skb); 274 if (unlikely(!skb)) 275 return 0; 276 277 /* hooks should never assume socket lock is held. 278 * we promote our socket to non const 279 */ 280 return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, 281 net, (struct sock *)sk, skb, NULL, dst->dev, 282 dst_output); 283 } 284 285 skb->dev = dst->dev; 286 /* ipv6_local_error() does not require socket lock, 287 * we promote our socket to non const 288 */ 289 ipv6_local_error((struct sock *)sk, EMSGSIZE, fl6, mtu); 290 291 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_FRAGFAILS); 292 kfree_skb(skb); 293 return -EMSGSIZE; 294 } 295 EXPORT_SYMBOL(ip6_xmit); 296 297 static int ip6_call_ra_chain(struct sk_buff *skb, int sel) 298 { 299 struct ip6_ra_chain *ra; 300 struct sock *last = NULL; 301 302 read_lock(&ip6_ra_lock); 303 for (ra = ip6_ra_chain; ra; ra = ra->next) { 304 struct sock *sk = ra->sk; 305 if (sk && ra->sel == sel && 306 (!sk->sk_bound_dev_if || 307 sk->sk_bound_dev_if == skb->dev->ifindex)) { 308 struct ipv6_pinfo *np = inet6_sk(sk); 309 310 if (np && np->rtalert_isolate && 311 !net_eq(sock_net(sk), dev_net(skb->dev))) { 312 continue; 313 } 314 if (last) { 315 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); 316 if (skb2) 317 rawv6_rcv(last, skb2); 318 } 319 last = sk; 320 } 321 } 322 323 if (last) { 324 rawv6_rcv(last, skb); 325 read_unlock(&ip6_ra_lock); 326 return 1; 327 } 328 read_unlock(&ip6_ra_lock); 329 return 0; 330 } 331 332 static int ip6_forward_proxy_check(struct sk_buff *skb) 333 { 334 struct ipv6hdr *hdr = ipv6_hdr(skb); 335 u8 nexthdr = hdr->nexthdr; 336 __be16 frag_off; 337 int offset; 338 339 if (ipv6_ext_hdr(nexthdr)) { 340 offset = ipv6_skip_exthdr(skb, sizeof(*hdr), &nexthdr, &frag_off); 341 if (offset < 0) 342 return 0; 343 } else 344 offset = sizeof(struct ipv6hdr); 345 346 if (nexthdr == IPPROTO_ICMPV6) { 347 struct icmp6hdr *icmp6; 348 349 if (!pskb_may_pull(skb, (skb_network_header(skb) + 350 offset + 1 - skb->data))) 351 return 0; 352 353 icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset); 354 355 switch (icmp6->icmp6_type) { 356 case NDISC_ROUTER_SOLICITATION: 357 case NDISC_ROUTER_ADVERTISEMENT: 358 case NDISC_NEIGHBOUR_SOLICITATION: 359 case NDISC_NEIGHBOUR_ADVERTISEMENT: 360 case NDISC_REDIRECT: 361 /* For reaction involving unicast neighbor discovery 362 * message destined to the proxied address, pass it to 363 * input function. 364 */ 365 return 1; 366 default: 367 break; 368 } 369 } 370 371 /* 372 * The proxying router can't forward traffic sent to a link-local 373 * address, so signal the sender and discard the packet. This 374 * behavior is clarified by the MIPv6 specification. 375 */ 376 if (ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) { 377 dst_link_failure(skb); 378 return -1; 379 } 380 381 return 0; 382 } 383 384 static inline int ip6_forward_finish(struct net *net, struct sock *sk, 385 struct sk_buff *skb) 386 { 387 struct dst_entry *dst = skb_dst(skb); 388 389 __IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTFORWDATAGRAMS); 390 __IP6_ADD_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTOCTETS, skb->len); 391 392 #ifdef CONFIG_NET_SWITCHDEV 393 if (skb->offload_l3_fwd_mark) { 394 consume_skb(skb); 395 return 0; 396 } 397 #endif 398 399 skb->tstamp = 0; 400 return dst_output(net, sk, skb); 401 } 402 403 static bool ip6_pkt_too_big(const struct sk_buff *skb, unsigned int mtu) 404 { 405 if (skb->len <= mtu) 406 return false; 407 408 /* ipv6 conntrack defrag sets max_frag_size + ignore_df */ 409 if (IP6CB(skb)->frag_max_size && IP6CB(skb)->frag_max_size > mtu) 410 return true; 411 412 if (skb->ignore_df) 413 return false; 414 415 if (skb_is_gso(skb) && skb_gso_validate_network_len(skb, mtu)) 416 return false; 417 418 return true; 419 } 420 421 int ip6_forward(struct sk_buff *skb) 422 { 423 struct inet6_dev *idev = __in6_dev_get_safely(skb->dev); 424 struct dst_entry *dst = skb_dst(skb); 425 struct ipv6hdr *hdr = ipv6_hdr(skb); 426 struct inet6_skb_parm *opt = IP6CB(skb); 427 struct net *net = dev_net(dst->dev); 428 u32 mtu; 429 430 if (net->ipv6.devconf_all->forwarding == 0) 431 goto error; 432 433 if (skb->pkt_type != PACKET_HOST) 434 goto drop; 435 436 if (unlikely(skb->sk)) 437 goto drop; 438 439 if (skb_warn_if_lro(skb)) 440 goto drop; 441 442 if (!xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) { 443 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS); 444 goto drop; 445 } 446 447 skb_forward_csum(skb); 448 449 /* 450 * We DO NOT make any processing on 451 * RA packets, pushing them to user level AS IS 452 * without ane WARRANTY that application will be able 453 * to interpret them. The reason is that we 454 * cannot make anything clever here. 455 * 456 * We are not end-node, so that if packet contains 457 * AH/ESP, we cannot make anything. 458 * Defragmentation also would be mistake, RA packets 459 * cannot be fragmented, because there is no warranty 460 * that different fragments will go along one path. --ANK 461 */ 462 if (unlikely(opt->flags & IP6SKB_ROUTERALERT)) { 463 if (ip6_call_ra_chain(skb, ntohs(opt->ra))) 464 return 0; 465 } 466 467 /* 468 * check and decrement ttl 469 */ 470 if (hdr->hop_limit <= 1) { 471 /* Force OUTPUT device used as source address */ 472 skb->dev = dst->dev; 473 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 0); 474 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 475 476 kfree_skb(skb); 477 return -ETIMEDOUT; 478 } 479 480 /* XXX: idev->cnf.proxy_ndp? */ 481 if (net->ipv6.devconf_all->proxy_ndp && 482 pneigh_lookup(&nd_tbl, net, &hdr->daddr, skb->dev, 0)) { 483 int proxied = ip6_forward_proxy_check(skb); 484 if (proxied > 0) 485 return ip6_input(skb); 486 else if (proxied < 0) { 487 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS); 488 goto drop; 489 } 490 } 491 492 if (!xfrm6_route_forward(skb)) { 493 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS); 494 goto drop; 495 } 496 dst = skb_dst(skb); 497 498 /* IPv6 specs say nothing about it, but it is clear that we cannot 499 send redirects to source routed frames. 500 We don't send redirects to frames decapsulated from IPsec. 501 */ 502 if (IP6CB(skb)->iif == dst->dev->ifindex && 503 opt->srcrt == 0 && !skb_sec_path(skb)) { 504 struct in6_addr *target = NULL; 505 struct inet_peer *peer; 506 struct rt6_info *rt; 507 508 /* 509 * incoming and outgoing devices are the same 510 * send a redirect. 511 */ 512 513 rt = (struct rt6_info *) dst; 514 if (rt->rt6i_flags & RTF_GATEWAY) 515 target = &rt->rt6i_gateway; 516 else 517 target = &hdr->daddr; 518 519 peer = inet_getpeer_v6(net->ipv6.peers, &hdr->daddr, 1); 520 521 /* Limit redirects both by destination (here) 522 and by source (inside ndisc_send_redirect) 523 */ 524 if (inet_peer_xrlim_allow(peer, 1*HZ)) 525 ndisc_send_redirect(skb, target); 526 if (peer) 527 inet_putpeer(peer); 528 } else { 529 int addrtype = ipv6_addr_type(&hdr->saddr); 530 531 /* This check is security critical. */ 532 if (addrtype == IPV6_ADDR_ANY || 533 addrtype & (IPV6_ADDR_MULTICAST | IPV6_ADDR_LOOPBACK)) 534 goto error; 535 if (addrtype & IPV6_ADDR_LINKLOCAL) { 536 icmpv6_send(skb, ICMPV6_DEST_UNREACH, 537 ICMPV6_NOT_NEIGHBOUR, 0); 538 goto error; 539 } 540 } 541 542 mtu = ip6_dst_mtu_forward(dst); 543 if (mtu < IPV6_MIN_MTU) 544 mtu = IPV6_MIN_MTU; 545 546 if (ip6_pkt_too_big(skb, mtu)) { 547 /* Again, force OUTPUT device used as source address */ 548 skb->dev = dst->dev; 549 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 550 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INTOOBIGERRORS); 551 __IP6_INC_STATS(net, ip6_dst_idev(dst), 552 IPSTATS_MIB_FRAGFAILS); 553 kfree_skb(skb); 554 return -EMSGSIZE; 555 } 556 557 if (skb_cow(skb, dst->dev->hard_header_len)) { 558 __IP6_INC_STATS(net, ip6_dst_idev(dst), 559 IPSTATS_MIB_OUTDISCARDS); 560 goto drop; 561 } 562 563 hdr = ipv6_hdr(skb); 564 565 /* Mangling hops number delayed to point after skb COW */ 566 567 hdr->hop_limit--; 568 569 return NF_HOOK(NFPROTO_IPV6, NF_INET_FORWARD, 570 net, NULL, skb, skb->dev, dst->dev, 571 ip6_forward_finish); 572 573 error: 574 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); 575 drop: 576 kfree_skb(skb); 577 return -EINVAL; 578 } 579 580 static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from) 581 { 582 to->pkt_type = from->pkt_type; 583 to->priority = from->priority; 584 to->protocol = from->protocol; 585 skb_dst_drop(to); 586 skb_dst_set(to, dst_clone(skb_dst(from))); 587 to->dev = from->dev; 588 to->mark = from->mark; 589 590 skb_copy_hash(to, from); 591 592 #ifdef CONFIG_NET_SCHED 593 to->tc_index = from->tc_index; 594 #endif 595 nf_copy(to, from); 596 skb_ext_copy(to, from); 597 skb_copy_secmark(to, from); 598 } 599 600 int ip6_fraglist_init(struct sk_buff *skb, unsigned int hlen, u8 *prevhdr, 601 u8 nexthdr, __be32 frag_id, 602 struct ip6_fraglist_iter *iter) 603 { 604 unsigned int first_len; 605 struct frag_hdr *fh; 606 607 /* BUILD HEADER */ 608 *prevhdr = NEXTHDR_FRAGMENT; 609 iter->tmp_hdr = kmemdup(skb_network_header(skb), hlen, GFP_ATOMIC); 610 if (!iter->tmp_hdr) 611 return -ENOMEM; 612 613 iter->frag = skb_shinfo(skb)->frag_list; 614 skb_frag_list_init(skb); 615 616 iter->offset = 0; 617 iter->hlen = hlen; 618 iter->frag_id = frag_id; 619 iter->nexthdr = nexthdr; 620 621 __skb_pull(skb, hlen); 622 fh = __skb_push(skb, sizeof(struct frag_hdr)); 623 __skb_push(skb, hlen); 624 skb_reset_network_header(skb); 625 memcpy(skb_network_header(skb), iter->tmp_hdr, hlen); 626 627 fh->nexthdr = nexthdr; 628 fh->reserved = 0; 629 fh->frag_off = htons(IP6_MF); 630 fh->identification = frag_id; 631 632 first_len = skb_pagelen(skb); 633 skb->data_len = first_len - skb_headlen(skb); 634 skb->len = first_len; 635 ipv6_hdr(skb)->payload_len = htons(first_len - sizeof(struct ipv6hdr)); 636 637 return 0; 638 } 639 EXPORT_SYMBOL(ip6_fraglist_init); 640 641 void ip6_fraglist_prepare(struct sk_buff *skb, 642 struct ip6_fraglist_iter *iter) 643 { 644 struct sk_buff *frag = iter->frag; 645 unsigned int hlen = iter->hlen; 646 struct frag_hdr *fh; 647 648 frag->ip_summed = CHECKSUM_NONE; 649 skb_reset_transport_header(frag); 650 fh = __skb_push(frag, sizeof(struct frag_hdr)); 651 __skb_push(frag, hlen); 652 skb_reset_network_header(frag); 653 memcpy(skb_network_header(frag), iter->tmp_hdr, hlen); 654 iter->offset += skb->len - hlen - sizeof(struct frag_hdr); 655 fh->nexthdr = iter->nexthdr; 656 fh->reserved = 0; 657 fh->frag_off = htons(iter->offset); 658 if (frag->next) 659 fh->frag_off |= htons(IP6_MF); 660 fh->identification = iter->frag_id; 661 ipv6_hdr(frag)->payload_len = htons(frag->len - sizeof(struct ipv6hdr)); 662 ip6_copy_metadata(frag, skb); 663 } 664 EXPORT_SYMBOL(ip6_fraglist_prepare); 665 666 void ip6_frag_init(struct sk_buff *skb, unsigned int hlen, unsigned int mtu, 667 unsigned short needed_tailroom, int hdr_room, u8 *prevhdr, 668 u8 nexthdr, __be32 frag_id, struct ip6_frag_state *state) 669 { 670 state->prevhdr = prevhdr; 671 state->nexthdr = nexthdr; 672 state->frag_id = frag_id; 673 674 state->hlen = hlen; 675 state->mtu = mtu; 676 677 state->left = skb->len - hlen; /* Space per frame */ 678 state->ptr = hlen; /* Where to start from */ 679 680 state->hroom = hdr_room; 681 state->troom = needed_tailroom; 682 683 state->offset = 0; 684 } 685 EXPORT_SYMBOL(ip6_frag_init); 686 687 struct sk_buff *ip6_frag_next(struct sk_buff *skb, struct ip6_frag_state *state) 688 { 689 u8 *prevhdr = state->prevhdr, *fragnexthdr_offset; 690 struct sk_buff *frag; 691 struct frag_hdr *fh; 692 unsigned int len; 693 694 len = state->left; 695 /* IF: it doesn't fit, use 'mtu' - the data space left */ 696 if (len > state->mtu) 697 len = state->mtu; 698 /* IF: we are not sending up to and including the packet end 699 then align the next start on an eight byte boundary */ 700 if (len < state->left) 701 len &= ~7; 702 703 /* Allocate buffer */ 704 frag = alloc_skb(len + state->hlen + sizeof(struct frag_hdr) + 705 state->hroom + state->troom, GFP_ATOMIC); 706 if (!frag) 707 return ERR_PTR(-ENOMEM); 708 709 /* 710 * Set up data on packet 711 */ 712 713 ip6_copy_metadata(frag, skb); 714 skb_reserve(frag, state->hroom); 715 skb_put(frag, len + state->hlen + sizeof(struct frag_hdr)); 716 skb_reset_network_header(frag); 717 fh = (struct frag_hdr *)(skb_network_header(frag) + state->hlen); 718 frag->transport_header = (frag->network_header + state->hlen + 719 sizeof(struct frag_hdr)); 720 721 /* 722 * Charge the memory for the fragment to any owner 723 * it might possess 724 */ 725 if (skb->sk) 726 skb_set_owner_w(frag, skb->sk); 727 728 /* 729 * Copy the packet header into the new buffer. 730 */ 731 skb_copy_from_linear_data(skb, skb_network_header(frag), state->hlen); 732 733 fragnexthdr_offset = skb_network_header(frag); 734 fragnexthdr_offset += prevhdr - skb_network_header(skb); 735 *fragnexthdr_offset = NEXTHDR_FRAGMENT; 736 737 /* 738 * Build fragment header. 739 */ 740 fh->nexthdr = state->nexthdr; 741 fh->reserved = 0; 742 fh->identification = state->frag_id; 743 744 /* 745 * Copy a block of the IP datagram. 746 */ 747 BUG_ON(skb_copy_bits(skb, state->ptr, skb_transport_header(frag), 748 len)); 749 state->left -= len; 750 751 fh->frag_off = htons(state->offset); 752 if (state->left > 0) 753 fh->frag_off |= htons(IP6_MF); 754 ipv6_hdr(frag)->payload_len = htons(frag->len - sizeof(struct ipv6hdr)); 755 756 state->ptr += len; 757 state->offset += len; 758 759 return frag; 760 } 761 EXPORT_SYMBOL(ip6_frag_next); 762 763 int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, 764 int (*output)(struct net *, struct sock *, struct sk_buff *)) 765 { 766 struct sk_buff *frag; 767 struct rt6_info *rt = (struct rt6_info *)skb_dst(skb); 768 struct ipv6_pinfo *np = skb->sk && !dev_recursion_level() ? 769 inet6_sk(skb->sk) : NULL; 770 struct ip6_frag_state state; 771 unsigned int mtu, hlen, nexthdr_offset; 772 ktime_t tstamp = skb->tstamp; 773 int hroom, err = 0; 774 __be32 frag_id; 775 u8 *prevhdr, nexthdr = 0; 776 777 err = ip6_find_1stfragopt(skb, &prevhdr); 778 if (err < 0) 779 goto fail; 780 hlen = err; 781 nexthdr = *prevhdr; 782 nexthdr_offset = prevhdr - skb_network_header(skb); 783 784 mtu = ip6_skb_dst_mtu(skb); 785 786 /* We must not fragment if the socket is set to force MTU discovery 787 * or if the skb it not generated by a local socket. 788 */ 789 if (unlikely(!skb->ignore_df && skb->len > mtu)) 790 goto fail_toobig; 791 792 if (IP6CB(skb)->frag_max_size) { 793 if (IP6CB(skb)->frag_max_size > mtu) 794 goto fail_toobig; 795 796 /* don't send fragments larger than what we received */ 797 mtu = IP6CB(skb)->frag_max_size; 798 if (mtu < IPV6_MIN_MTU) 799 mtu = IPV6_MIN_MTU; 800 } 801 802 if (np && np->frag_size < mtu) { 803 if (np->frag_size) 804 mtu = np->frag_size; 805 } 806 if (mtu < hlen + sizeof(struct frag_hdr) + 8) 807 goto fail_toobig; 808 mtu -= hlen + sizeof(struct frag_hdr); 809 810 frag_id = ipv6_select_ident(net, &ipv6_hdr(skb)->daddr, 811 &ipv6_hdr(skb)->saddr); 812 813 if (skb->ip_summed == CHECKSUM_PARTIAL && 814 (err = skb_checksum_help(skb))) 815 goto fail; 816 817 prevhdr = skb_network_header(skb) + nexthdr_offset; 818 hroom = LL_RESERVED_SPACE(rt->dst.dev); 819 if (skb_has_frag_list(skb)) { 820 unsigned int first_len = skb_pagelen(skb); 821 struct ip6_fraglist_iter iter; 822 struct sk_buff *frag2; 823 824 if (first_len - hlen > mtu || 825 ((first_len - hlen) & 7) || 826 skb_cloned(skb) || 827 skb_headroom(skb) < (hroom + sizeof(struct frag_hdr))) 828 goto slow_path; 829 830 skb_walk_frags(skb, frag) { 831 /* Correct geometry. */ 832 if (frag->len > mtu || 833 ((frag->len & 7) && frag->next) || 834 skb_headroom(frag) < (hlen + hroom + sizeof(struct frag_hdr))) 835 goto slow_path_clean; 836 837 /* Partially cloned skb? */ 838 if (skb_shared(frag)) 839 goto slow_path_clean; 840 841 BUG_ON(frag->sk); 842 if (skb->sk) { 843 frag->sk = skb->sk; 844 frag->destructor = sock_wfree; 845 } 846 skb->truesize -= frag->truesize; 847 } 848 849 err = ip6_fraglist_init(skb, hlen, prevhdr, nexthdr, frag_id, 850 &iter); 851 if (err < 0) 852 goto fail; 853 854 for (;;) { 855 /* Prepare header of the next frame, 856 * before previous one went down. */ 857 if (iter.frag) 858 ip6_fraglist_prepare(skb, &iter); 859 860 skb->tstamp = tstamp; 861 err = output(net, sk, skb); 862 if (!err) 863 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst), 864 IPSTATS_MIB_FRAGCREATES); 865 866 if (err || !iter.frag) 867 break; 868 869 skb = ip6_fraglist_next(&iter); 870 } 871 872 kfree(iter.tmp_hdr); 873 874 if (err == 0) { 875 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst), 876 IPSTATS_MIB_FRAGOKS); 877 return 0; 878 } 879 880 kfree_skb_list(iter.frag); 881 882 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst), 883 IPSTATS_MIB_FRAGFAILS); 884 return err; 885 886 slow_path_clean: 887 skb_walk_frags(skb, frag2) { 888 if (frag2 == frag) 889 break; 890 frag2->sk = NULL; 891 frag2->destructor = NULL; 892 skb->truesize += frag2->truesize; 893 } 894 } 895 896 slow_path: 897 /* 898 * Fragment the datagram. 899 */ 900 901 ip6_frag_init(skb, hlen, mtu, rt->dst.dev->needed_tailroom, 902 LL_RESERVED_SPACE(rt->dst.dev), prevhdr, nexthdr, frag_id, 903 &state); 904 905 /* 906 * Keep copying data until we run out. 907 */ 908 909 while (state.left > 0) { 910 frag = ip6_frag_next(skb, &state); 911 if (IS_ERR(frag)) { 912 err = PTR_ERR(frag); 913 goto fail; 914 } 915 916 /* 917 * Put this fragment into the sending queue. 918 */ 919 frag->tstamp = tstamp; 920 err = output(net, sk, frag); 921 if (err) 922 goto fail; 923 924 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 925 IPSTATS_MIB_FRAGCREATES); 926 } 927 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 928 IPSTATS_MIB_FRAGOKS); 929 consume_skb(skb); 930 return err; 931 932 fail_toobig: 933 if (skb->sk && dst_allfrag(skb_dst(skb))) 934 sk_nocaps_add(skb->sk, NETIF_F_GSO_MASK); 935 936 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 937 err = -EMSGSIZE; 938 939 fail: 940 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 941 IPSTATS_MIB_FRAGFAILS); 942 kfree_skb(skb); 943 return err; 944 } 945 946 static inline int ip6_rt_check(const struct rt6key *rt_key, 947 const struct in6_addr *fl_addr, 948 const struct in6_addr *addr_cache) 949 { 950 return (rt_key->plen != 128 || !ipv6_addr_equal(fl_addr, &rt_key->addr)) && 951 (!addr_cache || !ipv6_addr_equal(fl_addr, addr_cache)); 952 } 953 954 static struct dst_entry *ip6_sk_dst_check(struct sock *sk, 955 struct dst_entry *dst, 956 const struct flowi6 *fl6) 957 { 958 struct ipv6_pinfo *np = inet6_sk(sk); 959 struct rt6_info *rt; 960 961 if (!dst) 962 goto out; 963 964 if (dst->ops->family != AF_INET6) { 965 dst_release(dst); 966 return NULL; 967 } 968 969 rt = (struct rt6_info *)dst; 970 /* Yes, checking route validity in not connected 971 * case is not very simple. Take into account, 972 * that we do not support routing by source, TOS, 973 * and MSG_DONTROUTE --ANK (980726) 974 * 975 * 1. ip6_rt_check(): If route was host route, 976 * check that cached destination is current. 977 * If it is network route, we still may 978 * check its validity using saved pointer 979 * to the last used address: daddr_cache. 980 * We do not want to save whole address now, 981 * (because main consumer of this service 982 * is tcp, which has not this problem), 983 * so that the last trick works only on connected 984 * sockets. 985 * 2. oif also should be the same. 986 */ 987 if (ip6_rt_check(&rt->rt6i_dst, &fl6->daddr, np->daddr_cache) || 988 #ifdef CONFIG_IPV6_SUBTREES 989 ip6_rt_check(&rt->rt6i_src, &fl6->saddr, np->saddr_cache) || 990 #endif 991 (!(fl6->flowi6_flags & FLOWI_FLAG_SKIP_NH_OIF) && 992 (fl6->flowi6_oif && fl6->flowi6_oif != dst->dev->ifindex))) { 993 dst_release(dst); 994 dst = NULL; 995 } 996 997 out: 998 return dst; 999 } 1000 1001 static int ip6_dst_lookup_tail(struct net *net, const struct sock *sk, 1002 struct dst_entry **dst, struct flowi6 *fl6) 1003 { 1004 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD 1005 struct neighbour *n; 1006 struct rt6_info *rt; 1007 #endif 1008 int err; 1009 int flags = 0; 1010 1011 /* The correct way to handle this would be to do 1012 * ip6_route_get_saddr, and then ip6_route_output; however, 1013 * the route-specific preferred source forces the 1014 * ip6_route_output call _before_ ip6_route_get_saddr. 1015 * 1016 * In source specific routing (no src=any default route), 1017 * ip6_route_output will fail given src=any saddr, though, so 1018 * that's why we try it again later. 1019 */ 1020 if (ipv6_addr_any(&fl6->saddr) && (!*dst || !(*dst)->error)) { 1021 struct fib6_info *from; 1022 struct rt6_info *rt; 1023 bool had_dst = *dst != NULL; 1024 1025 if (!had_dst) 1026 *dst = ip6_route_output(net, sk, fl6); 1027 rt = (*dst)->error ? NULL : (struct rt6_info *)*dst; 1028 1029 rcu_read_lock(); 1030 from = rt ? rcu_dereference(rt->from) : NULL; 1031 err = ip6_route_get_saddr(net, from, &fl6->daddr, 1032 sk ? inet6_sk(sk)->srcprefs : 0, 1033 &fl6->saddr); 1034 rcu_read_unlock(); 1035 1036 if (err) 1037 goto out_err_release; 1038 1039 /* If we had an erroneous initial result, pretend it 1040 * never existed and let the SA-enabled version take 1041 * over. 1042 */ 1043 if (!had_dst && (*dst)->error) { 1044 dst_release(*dst); 1045 *dst = NULL; 1046 } 1047 1048 if (fl6->flowi6_oif) 1049 flags |= RT6_LOOKUP_F_IFACE; 1050 } 1051 1052 if (!*dst) 1053 *dst = ip6_route_output_flags(net, sk, fl6, flags); 1054 1055 err = (*dst)->error; 1056 if (err) 1057 goto out_err_release; 1058 1059 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD 1060 /* 1061 * Here if the dst entry we've looked up 1062 * has a neighbour entry that is in the INCOMPLETE 1063 * state and the src address from the flow is 1064 * marked as OPTIMISTIC, we release the found 1065 * dst entry and replace it instead with the 1066 * dst entry of the nexthop router 1067 */ 1068 rt = (struct rt6_info *) *dst; 1069 rcu_read_lock_bh(); 1070 n = __ipv6_neigh_lookup_noref(rt->dst.dev, 1071 rt6_nexthop(rt, &fl6->daddr)); 1072 err = n && !(n->nud_state & NUD_VALID) ? -EINVAL : 0; 1073 rcu_read_unlock_bh(); 1074 1075 if (err) { 1076 struct inet6_ifaddr *ifp; 1077 struct flowi6 fl_gw6; 1078 int redirect; 1079 1080 ifp = ipv6_get_ifaddr(net, &fl6->saddr, 1081 (*dst)->dev, 1); 1082 1083 redirect = (ifp && ifp->flags & IFA_F_OPTIMISTIC); 1084 if (ifp) 1085 in6_ifa_put(ifp); 1086 1087 if (redirect) { 1088 /* 1089 * We need to get the dst entry for the 1090 * default router instead 1091 */ 1092 dst_release(*dst); 1093 memcpy(&fl_gw6, fl6, sizeof(struct flowi6)); 1094 memset(&fl_gw6.daddr, 0, sizeof(struct in6_addr)); 1095 *dst = ip6_route_output(net, sk, &fl_gw6); 1096 err = (*dst)->error; 1097 if (err) 1098 goto out_err_release; 1099 } 1100 } 1101 #endif 1102 if (ipv6_addr_v4mapped(&fl6->saddr) && 1103 !(ipv6_addr_v4mapped(&fl6->daddr) || ipv6_addr_any(&fl6->daddr))) { 1104 err = -EAFNOSUPPORT; 1105 goto out_err_release; 1106 } 1107 1108 return 0; 1109 1110 out_err_release: 1111 dst_release(*dst); 1112 *dst = NULL; 1113 1114 if (err == -ENETUNREACH) 1115 IP6_INC_STATS(net, NULL, IPSTATS_MIB_OUTNOROUTES); 1116 return err; 1117 } 1118 1119 /** 1120 * ip6_dst_lookup - perform route lookup on flow 1121 * @net: Network namespace to perform lookup in 1122 * @sk: socket which provides route info 1123 * @dst: pointer to dst_entry * for result 1124 * @fl6: flow to lookup 1125 * 1126 * This function performs a route lookup on the given flow. 1127 * 1128 * It returns zero on success, or a standard errno code on error. 1129 */ 1130 int ip6_dst_lookup(struct net *net, struct sock *sk, struct dst_entry **dst, 1131 struct flowi6 *fl6) 1132 { 1133 *dst = NULL; 1134 return ip6_dst_lookup_tail(net, sk, dst, fl6); 1135 } 1136 EXPORT_SYMBOL_GPL(ip6_dst_lookup); 1137 1138 /** 1139 * ip6_dst_lookup_flow - perform route lookup on flow with ipsec 1140 * @net: Network namespace to perform lookup in 1141 * @sk: socket which provides route info 1142 * @fl6: flow to lookup 1143 * @final_dst: final destination address for ipsec lookup 1144 * 1145 * This function performs a route lookup on the given flow. 1146 * 1147 * It returns a valid dst pointer on success, or a pointer encoded 1148 * error code. 1149 */ 1150 struct dst_entry *ip6_dst_lookup_flow(struct net *net, const struct sock *sk, struct flowi6 *fl6, 1151 const struct in6_addr *final_dst) 1152 { 1153 struct dst_entry *dst = NULL; 1154 int err; 1155 1156 err = ip6_dst_lookup_tail(net, sk, &dst, fl6); 1157 if (err) 1158 return ERR_PTR(err); 1159 if (final_dst) 1160 fl6->daddr = *final_dst; 1161 1162 return xfrm_lookup_route(net, dst, flowi6_to_flowi(fl6), sk, 0); 1163 } 1164 EXPORT_SYMBOL_GPL(ip6_dst_lookup_flow); 1165 1166 /** 1167 * ip6_sk_dst_lookup_flow - perform socket cached route lookup on flow 1168 * @sk: socket which provides the dst cache and route info 1169 * @fl6: flow to lookup 1170 * @final_dst: final destination address for ipsec lookup 1171 * @connected: whether @sk is connected or not 1172 * 1173 * This function performs a route lookup on the given flow with the 1174 * possibility of using the cached route in the socket if it is valid. 1175 * It will take the socket dst lock when operating on the dst cache. 1176 * As a result, this function can only be used in process context. 1177 * 1178 * In addition, for a connected socket, cache the dst in the socket 1179 * if the current cache is not valid. 1180 * 1181 * It returns a valid dst pointer on success, or a pointer encoded 1182 * error code. 1183 */ 1184 struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6, 1185 const struct in6_addr *final_dst, 1186 bool connected) 1187 { 1188 struct dst_entry *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie); 1189 1190 dst = ip6_sk_dst_check(sk, dst, fl6); 1191 if (dst) 1192 return dst; 1193 1194 dst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_dst); 1195 if (connected && !IS_ERR(dst)) 1196 ip6_sk_dst_store_flow(sk, dst_clone(dst), fl6); 1197 1198 return dst; 1199 } 1200 EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup_flow); 1201 1202 /** 1203 * ip6_dst_lookup_tunnel - perform route lookup on tunnel 1204 * @skb: Packet for which lookup is done 1205 * @dev: Tunnel device 1206 * @net: Network namespace of tunnel device 1207 * @sock: Socket which provides route info 1208 * @saddr: Memory to store the src ip address 1209 * @info: Tunnel information 1210 * @protocol: IP protocol 1211 * @use_cache: Flag to enable cache usage 1212 * This function performs a route lookup on a tunnel 1213 * 1214 * It returns a valid dst pointer and stores src address to be used in 1215 * tunnel in param saddr on success, else a pointer encoded error code. 1216 */ 1217 1218 struct dst_entry *ip6_dst_lookup_tunnel(struct sk_buff *skb, 1219 struct net_device *dev, 1220 struct net *net, 1221 struct socket *sock, 1222 struct in6_addr *saddr, 1223 const struct ip_tunnel_info *info, 1224 u8 protocol, 1225 bool use_cache) 1226 { 1227 struct dst_entry *dst = NULL; 1228 #ifdef CONFIG_DST_CACHE 1229 struct dst_cache *dst_cache; 1230 #endif 1231 struct flowi6 fl6; 1232 __u8 prio; 1233 1234 #ifdef CONFIG_DST_CACHE 1235 dst_cache = (struct dst_cache *)&info->dst_cache; 1236 if (use_cache) { 1237 dst = dst_cache_get_ip6(dst_cache, saddr); 1238 if (dst) 1239 return dst; 1240 } 1241 #endif 1242 memset(&fl6, 0, sizeof(fl6)); 1243 fl6.flowi6_mark = skb->mark; 1244 fl6.flowi6_proto = protocol; 1245 fl6.daddr = info->key.u.ipv6.dst; 1246 fl6.saddr = info->key.u.ipv6.src; 1247 prio = info->key.tos; 1248 fl6.flowlabel = ip6_make_flowinfo(RT_TOS(prio), 1249 info->key.label); 1250 1251 dst = ipv6_stub->ipv6_dst_lookup_flow(net, sock->sk, &fl6, 1252 NULL); 1253 if (IS_ERR(dst)) { 1254 netdev_dbg(dev, "no route to %pI6\n", &fl6.daddr); 1255 return ERR_PTR(-ENETUNREACH); 1256 } 1257 if (dst->dev == dev) { /* is this necessary? */ 1258 netdev_dbg(dev, "circular route to %pI6\n", &fl6.daddr); 1259 dst_release(dst); 1260 return ERR_PTR(-ELOOP); 1261 } 1262 #ifdef CONFIG_DST_CACHE 1263 if (use_cache) 1264 dst_cache_set_ip6(dst_cache, dst, &fl6.saddr); 1265 #endif 1266 *saddr = fl6.saddr; 1267 return dst; 1268 } 1269 EXPORT_SYMBOL_GPL(ip6_dst_lookup_tunnel); 1270 1271 static inline struct ipv6_opt_hdr *ip6_opt_dup(struct ipv6_opt_hdr *src, 1272 gfp_t gfp) 1273 { 1274 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL; 1275 } 1276 1277 static inline struct ipv6_rt_hdr *ip6_rthdr_dup(struct ipv6_rt_hdr *src, 1278 gfp_t gfp) 1279 { 1280 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL; 1281 } 1282 1283 static void ip6_append_data_mtu(unsigned int *mtu, 1284 int *maxfraglen, 1285 unsigned int fragheaderlen, 1286 struct sk_buff *skb, 1287 struct rt6_info *rt, 1288 unsigned int orig_mtu) 1289 { 1290 if (!(rt->dst.flags & DST_XFRM_TUNNEL)) { 1291 if (!skb) { 1292 /* first fragment, reserve header_len */ 1293 *mtu = orig_mtu - rt->dst.header_len; 1294 1295 } else { 1296 /* 1297 * this fragment is not first, the headers 1298 * space is regarded as data space. 1299 */ 1300 *mtu = orig_mtu; 1301 } 1302 *maxfraglen = ((*mtu - fragheaderlen) & ~7) 1303 + fragheaderlen - sizeof(struct frag_hdr); 1304 } 1305 } 1306 1307 static int ip6_setup_cork(struct sock *sk, struct inet_cork_full *cork, 1308 struct inet6_cork *v6_cork, struct ipcm6_cookie *ipc6, 1309 struct rt6_info *rt, struct flowi6 *fl6) 1310 { 1311 struct ipv6_pinfo *np = inet6_sk(sk); 1312 unsigned int mtu; 1313 struct ipv6_txoptions *opt = ipc6->opt; 1314 1315 /* 1316 * setup for corking 1317 */ 1318 if (opt) { 1319 if (WARN_ON(v6_cork->opt)) 1320 return -EINVAL; 1321 1322 v6_cork->opt = kzalloc(sizeof(*opt), sk->sk_allocation); 1323 if (unlikely(!v6_cork->opt)) 1324 return -ENOBUFS; 1325 1326 v6_cork->opt->tot_len = sizeof(*opt); 1327 v6_cork->opt->opt_flen = opt->opt_flen; 1328 v6_cork->opt->opt_nflen = opt->opt_nflen; 1329 1330 v6_cork->opt->dst0opt = ip6_opt_dup(opt->dst0opt, 1331 sk->sk_allocation); 1332 if (opt->dst0opt && !v6_cork->opt->dst0opt) 1333 return -ENOBUFS; 1334 1335 v6_cork->opt->dst1opt = ip6_opt_dup(opt->dst1opt, 1336 sk->sk_allocation); 1337 if (opt->dst1opt && !v6_cork->opt->dst1opt) 1338 return -ENOBUFS; 1339 1340 v6_cork->opt->hopopt = ip6_opt_dup(opt->hopopt, 1341 sk->sk_allocation); 1342 if (opt->hopopt && !v6_cork->opt->hopopt) 1343 return -ENOBUFS; 1344 1345 v6_cork->opt->srcrt = ip6_rthdr_dup(opt->srcrt, 1346 sk->sk_allocation); 1347 if (opt->srcrt && !v6_cork->opt->srcrt) 1348 return -ENOBUFS; 1349 1350 /* need source address above miyazawa*/ 1351 } 1352 dst_hold(&rt->dst); 1353 cork->base.dst = &rt->dst; 1354 cork->fl.u.ip6 = *fl6; 1355 v6_cork->hop_limit = ipc6->hlimit; 1356 v6_cork->tclass = ipc6->tclass; 1357 if (rt->dst.flags & DST_XFRM_TUNNEL) 1358 mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ? 1359 READ_ONCE(rt->dst.dev->mtu) : dst_mtu(&rt->dst); 1360 else 1361 mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ? 1362 READ_ONCE(rt->dst.dev->mtu) : dst_mtu(xfrm_dst_path(&rt->dst)); 1363 if (np->frag_size < mtu) { 1364 if (np->frag_size) 1365 mtu = np->frag_size; 1366 } 1367 if (mtu < IPV6_MIN_MTU) 1368 return -EINVAL; 1369 cork->base.fragsize = mtu; 1370 cork->base.gso_size = ipc6->gso_size; 1371 cork->base.tx_flags = 0; 1372 cork->base.mark = ipc6->sockc.mark; 1373 sock_tx_timestamp(sk, ipc6->sockc.tsflags, &cork->base.tx_flags); 1374 1375 if (dst_allfrag(xfrm_dst_path(&rt->dst))) 1376 cork->base.flags |= IPCORK_ALLFRAG; 1377 cork->base.length = 0; 1378 1379 cork->base.transmit_time = ipc6->sockc.transmit_time; 1380 1381 return 0; 1382 } 1383 1384 static int __ip6_append_data(struct sock *sk, 1385 struct flowi6 *fl6, 1386 struct sk_buff_head *queue, 1387 struct inet_cork *cork, 1388 struct inet6_cork *v6_cork, 1389 struct page_frag *pfrag, 1390 int getfrag(void *from, char *to, int offset, 1391 int len, int odd, struct sk_buff *skb), 1392 void *from, int length, int transhdrlen, 1393 unsigned int flags, struct ipcm6_cookie *ipc6) 1394 { 1395 struct sk_buff *skb, *skb_prev = NULL; 1396 unsigned int maxfraglen, fragheaderlen, mtu, orig_mtu, pmtu; 1397 struct ubuf_info *uarg = NULL; 1398 int exthdrlen = 0; 1399 int dst_exthdrlen = 0; 1400 int hh_len; 1401 int copy; 1402 int err; 1403 int offset = 0; 1404 u32 tskey = 0; 1405 struct rt6_info *rt = (struct rt6_info *)cork->dst; 1406 struct ipv6_txoptions *opt = v6_cork->opt; 1407 int csummode = CHECKSUM_NONE; 1408 unsigned int maxnonfragsize, headersize; 1409 unsigned int wmem_alloc_delta = 0; 1410 bool paged, extra_uref = false; 1411 1412 skb = skb_peek_tail(queue); 1413 if (!skb) { 1414 exthdrlen = opt ? opt->opt_flen : 0; 1415 dst_exthdrlen = rt->dst.header_len - rt->rt6i_nfheader_len; 1416 } 1417 1418 paged = !!cork->gso_size; 1419 mtu = cork->gso_size ? IP6_MAX_MTU : cork->fragsize; 1420 orig_mtu = mtu; 1421 1422 if (cork->tx_flags & SKBTX_ANY_SW_TSTAMP && 1423 sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID) 1424 tskey = sk->sk_tskey++; 1425 1426 hh_len = LL_RESERVED_SPACE(rt->dst.dev); 1427 1428 fragheaderlen = sizeof(struct ipv6hdr) + rt->rt6i_nfheader_len + 1429 (opt ? opt->opt_nflen : 0); 1430 maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - 1431 sizeof(struct frag_hdr); 1432 1433 headersize = sizeof(struct ipv6hdr) + 1434 (opt ? opt->opt_flen + opt->opt_nflen : 0) + 1435 (dst_allfrag(&rt->dst) ? 1436 sizeof(struct frag_hdr) : 0) + 1437 rt->rt6i_nfheader_len; 1438 1439 /* as per RFC 7112 section 5, the entire IPv6 Header Chain must fit 1440 * the first fragment 1441 */ 1442 if (headersize + transhdrlen > mtu) 1443 goto emsgsize; 1444 1445 if (cork->length + length > mtu - headersize && ipc6->dontfrag && 1446 (sk->sk_protocol == IPPROTO_UDP || 1447 sk->sk_protocol == IPPROTO_RAW)) { 1448 ipv6_local_rxpmtu(sk, fl6, mtu - headersize + 1449 sizeof(struct ipv6hdr)); 1450 goto emsgsize; 1451 } 1452 1453 if (ip6_sk_ignore_df(sk)) 1454 maxnonfragsize = sizeof(struct ipv6hdr) + IPV6_MAXPLEN; 1455 else 1456 maxnonfragsize = mtu; 1457 1458 if (cork->length + length > maxnonfragsize - headersize) { 1459 emsgsize: 1460 pmtu = max_t(int, mtu - headersize + sizeof(struct ipv6hdr), 0); 1461 ipv6_local_error(sk, EMSGSIZE, fl6, pmtu); 1462 return -EMSGSIZE; 1463 } 1464 1465 /* CHECKSUM_PARTIAL only with no extension headers and when 1466 * we are not going to fragment 1467 */ 1468 if (transhdrlen && sk->sk_protocol == IPPROTO_UDP && 1469 headersize == sizeof(struct ipv6hdr) && 1470 length <= mtu - headersize && 1471 (!(flags & MSG_MORE) || cork->gso_size) && 1472 rt->dst.dev->features & (NETIF_F_IPV6_CSUM | NETIF_F_HW_CSUM)) 1473 csummode = CHECKSUM_PARTIAL; 1474 1475 if (flags & MSG_ZEROCOPY && length && sock_flag(sk, SOCK_ZEROCOPY)) { 1476 uarg = sock_zerocopy_realloc(sk, length, skb_zcopy(skb)); 1477 if (!uarg) 1478 return -ENOBUFS; 1479 extra_uref = !skb_zcopy(skb); /* only ref on new uarg */ 1480 if (rt->dst.dev->features & NETIF_F_SG && 1481 csummode == CHECKSUM_PARTIAL) { 1482 paged = true; 1483 } else { 1484 uarg->zerocopy = 0; 1485 skb_zcopy_set(skb, uarg, &extra_uref); 1486 } 1487 } 1488 1489 /* 1490 * Let's try using as much space as possible. 1491 * Use MTU if total length of the message fits into the MTU. 1492 * Otherwise, we need to reserve fragment header and 1493 * fragment alignment (= 8-15 octects, in total). 1494 * 1495 * Note that we may need to "move" the data from the tail of 1496 * of the buffer to the new fragment when we split 1497 * the message. 1498 * 1499 * FIXME: It may be fragmented into multiple chunks 1500 * at once if non-fragmentable extension headers 1501 * are too large. 1502 * --yoshfuji 1503 */ 1504 1505 cork->length += length; 1506 if (!skb) 1507 goto alloc_new_skb; 1508 1509 while (length > 0) { 1510 /* Check if the remaining data fits into current packet. */ 1511 copy = (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len; 1512 if (copy < length) 1513 copy = maxfraglen - skb->len; 1514 1515 if (copy <= 0) { 1516 char *data; 1517 unsigned int datalen; 1518 unsigned int fraglen; 1519 unsigned int fraggap; 1520 unsigned int alloclen; 1521 unsigned int pagedlen; 1522 alloc_new_skb: 1523 /* There's no room in the current skb */ 1524 if (skb) 1525 fraggap = skb->len - maxfraglen; 1526 else 1527 fraggap = 0; 1528 /* update mtu and maxfraglen if necessary */ 1529 if (!skb || !skb_prev) 1530 ip6_append_data_mtu(&mtu, &maxfraglen, 1531 fragheaderlen, skb, rt, 1532 orig_mtu); 1533 1534 skb_prev = skb; 1535 1536 /* 1537 * If remaining data exceeds the mtu, 1538 * we know we need more fragment(s). 1539 */ 1540 datalen = length + fraggap; 1541 1542 if (datalen > (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen) 1543 datalen = maxfraglen - fragheaderlen - rt->dst.trailer_len; 1544 fraglen = datalen + fragheaderlen; 1545 pagedlen = 0; 1546 1547 if ((flags & MSG_MORE) && 1548 !(rt->dst.dev->features&NETIF_F_SG)) 1549 alloclen = mtu; 1550 else if (!paged) 1551 alloclen = fraglen; 1552 else { 1553 alloclen = min_t(int, fraglen, MAX_HEADER); 1554 pagedlen = fraglen - alloclen; 1555 } 1556 1557 alloclen += dst_exthdrlen; 1558 1559 if (datalen != length + fraggap) { 1560 /* 1561 * this is not the last fragment, the trailer 1562 * space is regarded as data space. 1563 */ 1564 datalen += rt->dst.trailer_len; 1565 } 1566 1567 alloclen += rt->dst.trailer_len; 1568 fraglen = datalen + fragheaderlen; 1569 1570 /* 1571 * We just reserve space for fragment header. 1572 * Note: this may be overallocation if the message 1573 * (without MSG_MORE) fits into the MTU. 1574 */ 1575 alloclen += sizeof(struct frag_hdr); 1576 1577 copy = datalen - transhdrlen - fraggap - pagedlen; 1578 if (copy < 0) { 1579 err = -EINVAL; 1580 goto error; 1581 } 1582 if (transhdrlen) { 1583 skb = sock_alloc_send_skb(sk, 1584 alloclen + hh_len, 1585 (flags & MSG_DONTWAIT), &err); 1586 } else { 1587 skb = NULL; 1588 if (refcount_read(&sk->sk_wmem_alloc) + wmem_alloc_delta <= 1589 2 * sk->sk_sndbuf) 1590 skb = alloc_skb(alloclen + hh_len, 1591 sk->sk_allocation); 1592 if (unlikely(!skb)) 1593 err = -ENOBUFS; 1594 } 1595 if (!skb) 1596 goto error; 1597 /* 1598 * Fill in the control structures 1599 */ 1600 skb->protocol = htons(ETH_P_IPV6); 1601 skb->ip_summed = csummode; 1602 skb->csum = 0; 1603 /* reserve for fragmentation and ipsec header */ 1604 skb_reserve(skb, hh_len + sizeof(struct frag_hdr) + 1605 dst_exthdrlen); 1606 1607 /* 1608 * Find where to start putting bytes 1609 */ 1610 data = skb_put(skb, fraglen - pagedlen); 1611 skb_set_network_header(skb, exthdrlen); 1612 data += fragheaderlen; 1613 skb->transport_header = (skb->network_header + 1614 fragheaderlen); 1615 if (fraggap) { 1616 skb->csum = skb_copy_and_csum_bits( 1617 skb_prev, maxfraglen, 1618 data + transhdrlen, fraggap, 0); 1619 skb_prev->csum = csum_sub(skb_prev->csum, 1620 skb->csum); 1621 data += fraggap; 1622 pskb_trim_unique(skb_prev, maxfraglen); 1623 } 1624 if (copy > 0 && 1625 getfrag(from, data + transhdrlen, offset, 1626 copy, fraggap, skb) < 0) { 1627 err = -EFAULT; 1628 kfree_skb(skb); 1629 goto error; 1630 } 1631 1632 offset += copy; 1633 length -= copy + transhdrlen; 1634 transhdrlen = 0; 1635 exthdrlen = 0; 1636 dst_exthdrlen = 0; 1637 1638 /* Only the initial fragment is time stamped */ 1639 skb_shinfo(skb)->tx_flags = cork->tx_flags; 1640 cork->tx_flags = 0; 1641 skb_shinfo(skb)->tskey = tskey; 1642 tskey = 0; 1643 skb_zcopy_set(skb, uarg, &extra_uref); 1644 1645 if ((flags & MSG_CONFIRM) && !skb_prev) 1646 skb_set_dst_pending_confirm(skb, 1); 1647 1648 /* 1649 * Put the packet on the pending queue 1650 */ 1651 if (!skb->destructor) { 1652 skb->destructor = sock_wfree; 1653 skb->sk = sk; 1654 wmem_alloc_delta += skb->truesize; 1655 } 1656 __skb_queue_tail(queue, skb); 1657 continue; 1658 } 1659 1660 if (copy > length) 1661 copy = length; 1662 1663 if (!(rt->dst.dev->features&NETIF_F_SG) && 1664 skb_tailroom(skb) >= copy) { 1665 unsigned int off; 1666 1667 off = skb->len; 1668 if (getfrag(from, skb_put(skb, copy), 1669 offset, copy, off, skb) < 0) { 1670 __skb_trim(skb, off); 1671 err = -EFAULT; 1672 goto error; 1673 } 1674 } else if (!uarg || !uarg->zerocopy) { 1675 int i = skb_shinfo(skb)->nr_frags; 1676 1677 err = -ENOMEM; 1678 if (!sk_page_frag_refill(sk, pfrag)) 1679 goto error; 1680 1681 if (!skb_can_coalesce(skb, i, pfrag->page, 1682 pfrag->offset)) { 1683 err = -EMSGSIZE; 1684 if (i == MAX_SKB_FRAGS) 1685 goto error; 1686 1687 __skb_fill_page_desc(skb, i, pfrag->page, 1688 pfrag->offset, 0); 1689 skb_shinfo(skb)->nr_frags = ++i; 1690 get_page(pfrag->page); 1691 } 1692 copy = min_t(int, copy, pfrag->size - pfrag->offset); 1693 if (getfrag(from, 1694 page_address(pfrag->page) + pfrag->offset, 1695 offset, copy, skb->len, skb) < 0) 1696 goto error_efault; 1697 1698 pfrag->offset += copy; 1699 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); 1700 skb->len += copy; 1701 skb->data_len += copy; 1702 skb->truesize += copy; 1703 wmem_alloc_delta += copy; 1704 } else { 1705 err = skb_zerocopy_iter_dgram(skb, from, copy); 1706 if (err < 0) 1707 goto error; 1708 } 1709 offset += copy; 1710 length -= copy; 1711 } 1712 1713 if (wmem_alloc_delta) 1714 refcount_add(wmem_alloc_delta, &sk->sk_wmem_alloc); 1715 return 0; 1716 1717 error_efault: 1718 err = -EFAULT; 1719 error: 1720 if (uarg) 1721 sock_zerocopy_put_abort(uarg, extra_uref); 1722 cork->length -= length; 1723 IP6_INC_STATS(sock_net(sk), rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS); 1724 refcount_add(wmem_alloc_delta, &sk->sk_wmem_alloc); 1725 return err; 1726 } 1727 1728 int ip6_append_data(struct sock *sk, 1729 int getfrag(void *from, char *to, int offset, int len, 1730 int odd, struct sk_buff *skb), 1731 void *from, int length, int transhdrlen, 1732 struct ipcm6_cookie *ipc6, struct flowi6 *fl6, 1733 struct rt6_info *rt, unsigned int flags) 1734 { 1735 struct inet_sock *inet = inet_sk(sk); 1736 struct ipv6_pinfo *np = inet6_sk(sk); 1737 int exthdrlen; 1738 int err; 1739 1740 if (flags&MSG_PROBE) 1741 return 0; 1742 if (skb_queue_empty(&sk->sk_write_queue)) { 1743 /* 1744 * setup for corking 1745 */ 1746 err = ip6_setup_cork(sk, &inet->cork, &np->cork, 1747 ipc6, rt, fl6); 1748 if (err) 1749 return err; 1750 1751 exthdrlen = (ipc6->opt ? ipc6->opt->opt_flen : 0); 1752 length += exthdrlen; 1753 transhdrlen += exthdrlen; 1754 } else { 1755 fl6 = &inet->cork.fl.u.ip6; 1756 transhdrlen = 0; 1757 } 1758 1759 return __ip6_append_data(sk, fl6, &sk->sk_write_queue, &inet->cork.base, 1760 &np->cork, sk_page_frag(sk), getfrag, 1761 from, length, transhdrlen, flags, ipc6); 1762 } 1763 EXPORT_SYMBOL_GPL(ip6_append_data); 1764 1765 static void ip6_cork_release(struct inet_cork_full *cork, 1766 struct inet6_cork *v6_cork) 1767 { 1768 if (v6_cork->opt) { 1769 kfree(v6_cork->opt->dst0opt); 1770 kfree(v6_cork->opt->dst1opt); 1771 kfree(v6_cork->opt->hopopt); 1772 kfree(v6_cork->opt->srcrt); 1773 kfree(v6_cork->opt); 1774 v6_cork->opt = NULL; 1775 } 1776 1777 if (cork->base.dst) { 1778 dst_release(cork->base.dst); 1779 cork->base.dst = NULL; 1780 cork->base.flags &= ~IPCORK_ALLFRAG; 1781 } 1782 memset(&cork->fl, 0, sizeof(cork->fl)); 1783 } 1784 1785 struct sk_buff *__ip6_make_skb(struct sock *sk, 1786 struct sk_buff_head *queue, 1787 struct inet_cork_full *cork, 1788 struct inet6_cork *v6_cork) 1789 { 1790 struct sk_buff *skb, *tmp_skb; 1791 struct sk_buff **tail_skb; 1792 struct in6_addr final_dst_buf, *final_dst = &final_dst_buf; 1793 struct ipv6_pinfo *np = inet6_sk(sk); 1794 struct net *net = sock_net(sk); 1795 struct ipv6hdr *hdr; 1796 struct ipv6_txoptions *opt = v6_cork->opt; 1797 struct rt6_info *rt = (struct rt6_info *)cork->base.dst; 1798 struct flowi6 *fl6 = &cork->fl.u.ip6; 1799 unsigned char proto = fl6->flowi6_proto; 1800 1801 skb = __skb_dequeue(queue); 1802 if (!skb) 1803 goto out; 1804 tail_skb = &(skb_shinfo(skb)->frag_list); 1805 1806 /* move skb->data to ip header from ext header */ 1807 if (skb->data < skb_network_header(skb)) 1808 __skb_pull(skb, skb_network_offset(skb)); 1809 while ((tmp_skb = __skb_dequeue(queue)) != NULL) { 1810 __skb_pull(tmp_skb, skb_network_header_len(skb)); 1811 *tail_skb = tmp_skb; 1812 tail_skb = &(tmp_skb->next); 1813 skb->len += tmp_skb->len; 1814 skb->data_len += tmp_skb->len; 1815 skb->truesize += tmp_skb->truesize; 1816 tmp_skb->destructor = NULL; 1817 tmp_skb->sk = NULL; 1818 } 1819 1820 /* Allow local fragmentation. */ 1821 skb->ignore_df = ip6_sk_ignore_df(sk); 1822 1823 *final_dst = fl6->daddr; 1824 __skb_pull(skb, skb_network_header_len(skb)); 1825 if (opt && opt->opt_flen) 1826 ipv6_push_frag_opts(skb, opt, &proto); 1827 if (opt && opt->opt_nflen) 1828 ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst, &fl6->saddr); 1829 1830 skb_push(skb, sizeof(struct ipv6hdr)); 1831 skb_reset_network_header(skb); 1832 hdr = ipv6_hdr(skb); 1833 1834 ip6_flow_hdr(hdr, v6_cork->tclass, 1835 ip6_make_flowlabel(net, skb, fl6->flowlabel, 1836 ip6_autoflowlabel(net, np), fl6)); 1837 hdr->hop_limit = v6_cork->hop_limit; 1838 hdr->nexthdr = proto; 1839 hdr->saddr = fl6->saddr; 1840 hdr->daddr = *final_dst; 1841 1842 skb->priority = sk->sk_priority; 1843 skb->mark = cork->base.mark; 1844 1845 skb->tstamp = cork->base.transmit_time; 1846 1847 skb_dst_set(skb, dst_clone(&rt->dst)); 1848 IP6_UPD_PO_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUT, skb->len); 1849 if (proto == IPPROTO_ICMPV6) { 1850 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); 1851 1852 ICMP6MSGOUT_INC_STATS(net, idev, icmp6_hdr(skb)->icmp6_type); 1853 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS); 1854 } 1855 1856 ip6_cork_release(cork, v6_cork); 1857 out: 1858 return skb; 1859 } 1860 1861 int ip6_send_skb(struct sk_buff *skb) 1862 { 1863 struct net *net = sock_net(skb->sk); 1864 struct rt6_info *rt = (struct rt6_info *)skb_dst(skb); 1865 int err; 1866 1867 err = ip6_local_out(net, skb->sk, skb); 1868 if (err) { 1869 if (err > 0) 1870 err = net_xmit_errno(err); 1871 if (err) 1872 IP6_INC_STATS(net, rt->rt6i_idev, 1873 IPSTATS_MIB_OUTDISCARDS); 1874 } 1875 1876 return err; 1877 } 1878 1879 int ip6_push_pending_frames(struct sock *sk) 1880 { 1881 struct sk_buff *skb; 1882 1883 skb = ip6_finish_skb(sk); 1884 if (!skb) 1885 return 0; 1886 1887 return ip6_send_skb(skb); 1888 } 1889 EXPORT_SYMBOL_GPL(ip6_push_pending_frames); 1890 1891 static void __ip6_flush_pending_frames(struct sock *sk, 1892 struct sk_buff_head *queue, 1893 struct inet_cork_full *cork, 1894 struct inet6_cork *v6_cork) 1895 { 1896 struct sk_buff *skb; 1897 1898 while ((skb = __skb_dequeue_tail(queue)) != NULL) { 1899 if (skb_dst(skb)) 1900 IP6_INC_STATS(sock_net(sk), ip6_dst_idev(skb_dst(skb)), 1901 IPSTATS_MIB_OUTDISCARDS); 1902 kfree_skb(skb); 1903 } 1904 1905 ip6_cork_release(cork, v6_cork); 1906 } 1907 1908 void ip6_flush_pending_frames(struct sock *sk) 1909 { 1910 __ip6_flush_pending_frames(sk, &sk->sk_write_queue, 1911 &inet_sk(sk)->cork, &inet6_sk(sk)->cork); 1912 } 1913 EXPORT_SYMBOL_GPL(ip6_flush_pending_frames); 1914 1915 struct sk_buff *ip6_make_skb(struct sock *sk, 1916 int getfrag(void *from, char *to, int offset, 1917 int len, int odd, struct sk_buff *skb), 1918 void *from, int length, int transhdrlen, 1919 struct ipcm6_cookie *ipc6, struct flowi6 *fl6, 1920 struct rt6_info *rt, unsigned int flags, 1921 struct inet_cork_full *cork) 1922 { 1923 struct inet6_cork v6_cork; 1924 struct sk_buff_head queue; 1925 int exthdrlen = (ipc6->opt ? ipc6->opt->opt_flen : 0); 1926 int err; 1927 1928 if (flags & MSG_PROBE) 1929 return NULL; 1930 1931 __skb_queue_head_init(&queue); 1932 1933 cork->base.flags = 0; 1934 cork->base.addr = 0; 1935 cork->base.opt = NULL; 1936 cork->base.dst = NULL; 1937 v6_cork.opt = NULL; 1938 err = ip6_setup_cork(sk, cork, &v6_cork, ipc6, rt, fl6); 1939 if (err) { 1940 ip6_cork_release(cork, &v6_cork); 1941 return ERR_PTR(err); 1942 } 1943 if (ipc6->dontfrag < 0) 1944 ipc6->dontfrag = inet6_sk(sk)->dontfrag; 1945 1946 err = __ip6_append_data(sk, fl6, &queue, &cork->base, &v6_cork, 1947 ¤t->task_frag, getfrag, from, 1948 length + exthdrlen, transhdrlen + exthdrlen, 1949 flags, ipc6); 1950 if (err) { 1951 __ip6_flush_pending_frames(sk, &queue, cork, &v6_cork); 1952 return ERR_PTR(err); 1953 } 1954 1955 return __ip6_make_skb(sk, &queue, cork, &v6_cork); 1956 } 1957