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 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 0); 472 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 473 474 kfree_skb(skb); 475 return -ETIMEDOUT; 476 } 477 478 /* XXX: idev->cnf.proxy_ndp? */ 479 if (net->ipv6.devconf_all->proxy_ndp && 480 pneigh_lookup(&nd_tbl, net, &hdr->daddr, skb->dev, 0)) { 481 int proxied = ip6_forward_proxy_check(skb); 482 if (proxied > 0) 483 return ip6_input(skb); 484 else if (proxied < 0) { 485 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS); 486 goto drop; 487 } 488 } 489 490 if (!xfrm6_route_forward(skb)) { 491 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS); 492 goto drop; 493 } 494 dst = skb_dst(skb); 495 496 /* IPv6 specs say nothing about it, but it is clear that we cannot 497 send redirects to source routed frames. 498 We don't send redirects to frames decapsulated from IPsec. 499 */ 500 if (IP6CB(skb)->iif == dst->dev->ifindex && 501 opt->srcrt == 0 && !skb_sec_path(skb)) { 502 struct in6_addr *target = NULL; 503 struct inet_peer *peer; 504 struct rt6_info *rt; 505 506 /* 507 * incoming and outgoing devices are the same 508 * send a redirect. 509 */ 510 511 rt = (struct rt6_info *) dst; 512 if (rt->rt6i_flags & RTF_GATEWAY) 513 target = &rt->rt6i_gateway; 514 else 515 target = &hdr->daddr; 516 517 peer = inet_getpeer_v6(net->ipv6.peers, &hdr->daddr, 1); 518 519 /* Limit redirects both by destination (here) 520 and by source (inside ndisc_send_redirect) 521 */ 522 if (inet_peer_xrlim_allow(peer, 1*HZ)) 523 ndisc_send_redirect(skb, target); 524 if (peer) 525 inet_putpeer(peer); 526 } else { 527 int addrtype = ipv6_addr_type(&hdr->saddr); 528 529 /* This check is security critical. */ 530 if (addrtype == IPV6_ADDR_ANY || 531 addrtype & (IPV6_ADDR_MULTICAST | IPV6_ADDR_LOOPBACK)) 532 goto error; 533 if (addrtype & IPV6_ADDR_LINKLOCAL) { 534 icmpv6_send(skb, ICMPV6_DEST_UNREACH, 535 ICMPV6_NOT_NEIGHBOUR, 0); 536 goto error; 537 } 538 } 539 540 mtu = ip6_dst_mtu_forward(dst); 541 if (mtu < IPV6_MIN_MTU) 542 mtu = IPV6_MIN_MTU; 543 544 if (ip6_pkt_too_big(skb, mtu)) { 545 /* Again, force OUTPUT device used as source address */ 546 skb->dev = dst->dev; 547 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 548 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INTOOBIGERRORS); 549 __IP6_INC_STATS(net, ip6_dst_idev(dst), 550 IPSTATS_MIB_FRAGFAILS); 551 kfree_skb(skb); 552 return -EMSGSIZE; 553 } 554 555 if (skb_cow(skb, dst->dev->hard_header_len)) { 556 __IP6_INC_STATS(net, ip6_dst_idev(dst), 557 IPSTATS_MIB_OUTDISCARDS); 558 goto drop; 559 } 560 561 hdr = ipv6_hdr(skb); 562 563 /* Mangling hops number delayed to point after skb COW */ 564 565 hdr->hop_limit--; 566 567 return NF_HOOK(NFPROTO_IPV6, NF_INET_FORWARD, 568 net, NULL, skb, skb->dev, dst->dev, 569 ip6_forward_finish); 570 571 error: 572 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); 573 drop: 574 kfree_skb(skb); 575 return -EINVAL; 576 } 577 578 static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from) 579 { 580 to->pkt_type = from->pkt_type; 581 to->priority = from->priority; 582 to->protocol = from->protocol; 583 skb_dst_drop(to); 584 skb_dst_set(to, dst_clone(skb_dst(from))); 585 to->dev = from->dev; 586 to->mark = from->mark; 587 588 skb_copy_hash(to, from); 589 590 #ifdef CONFIG_NET_SCHED 591 to->tc_index = from->tc_index; 592 #endif 593 nf_copy(to, from); 594 skb_ext_copy(to, from); 595 skb_copy_secmark(to, from); 596 } 597 598 int ip6_fraglist_init(struct sk_buff *skb, unsigned int hlen, u8 *prevhdr, 599 u8 nexthdr, __be32 frag_id, 600 struct ip6_fraglist_iter *iter) 601 { 602 unsigned int first_len; 603 struct frag_hdr *fh; 604 605 /* BUILD HEADER */ 606 *prevhdr = NEXTHDR_FRAGMENT; 607 iter->tmp_hdr = kmemdup(skb_network_header(skb), hlen, GFP_ATOMIC); 608 if (!iter->tmp_hdr) 609 return -ENOMEM; 610 611 iter->frag = skb_shinfo(skb)->frag_list; 612 skb_frag_list_init(skb); 613 614 iter->offset = 0; 615 iter->hlen = hlen; 616 iter->frag_id = frag_id; 617 iter->nexthdr = nexthdr; 618 619 __skb_pull(skb, hlen); 620 fh = __skb_push(skb, sizeof(struct frag_hdr)); 621 __skb_push(skb, hlen); 622 skb_reset_network_header(skb); 623 memcpy(skb_network_header(skb), iter->tmp_hdr, hlen); 624 625 fh->nexthdr = nexthdr; 626 fh->reserved = 0; 627 fh->frag_off = htons(IP6_MF); 628 fh->identification = frag_id; 629 630 first_len = skb_pagelen(skb); 631 skb->data_len = first_len - skb_headlen(skb); 632 skb->len = first_len; 633 ipv6_hdr(skb)->payload_len = htons(first_len - sizeof(struct ipv6hdr)); 634 635 return 0; 636 } 637 EXPORT_SYMBOL(ip6_fraglist_init); 638 639 void ip6_fraglist_prepare(struct sk_buff *skb, 640 struct ip6_fraglist_iter *iter) 641 { 642 struct sk_buff *frag = iter->frag; 643 unsigned int hlen = iter->hlen; 644 struct frag_hdr *fh; 645 646 frag->ip_summed = CHECKSUM_NONE; 647 skb_reset_transport_header(frag); 648 fh = __skb_push(frag, sizeof(struct frag_hdr)); 649 __skb_push(frag, hlen); 650 skb_reset_network_header(frag); 651 memcpy(skb_network_header(frag), iter->tmp_hdr, hlen); 652 iter->offset += skb->len - hlen - sizeof(struct frag_hdr); 653 fh->nexthdr = iter->nexthdr; 654 fh->reserved = 0; 655 fh->frag_off = htons(iter->offset); 656 if (frag->next) 657 fh->frag_off |= htons(IP6_MF); 658 fh->identification = iter->frag_id; 659 ipv6_hdr(frag)->payload_len = htons(frag->len - sizeof(struct ipv6hdr)); 660 ip6_copy_metadata(frag, skb); 661 } 662 EXPORT_SYMBOL(ip6_fraglist_prepare); 663 664 void ip6_frag_init(struct sk_buff *skb, unsigned int hlen, unsigned int mtu, 665 unsigned short needed_tailroom, int hdr_room, u8 *prevhdr, 666 u8 nexthdr, __be32 frag_id, struct ip6_frag_state *state) 667 { 668 state->prevhdr = prevhdr; 669 state->nexthdr = nexthdr; 670 state->frag_id = frag_id; 671 672 state->hlen = hlen; 673 state->mtu = mtu; 674 675 state->left = skb->len - hlen; /* Space per frame */ 676 state->ptr = hlen; /* Where to start from */ 677 678 state->hroom = hdr_room; 679 state->troom = needed_tailroom; 680 681 state->offset = 0; 682 } 683 EXPORT_SYMBOL(ip6_frag_init); 684 685 struct sk_buff *ip6_frag_next(struct sk_buff *skb, struct ip6_frag_state *state) 686 { 687 u8 *prevhdr = state->prevhdr, *fragnexthdr_offset; 688 struct sk_buff *frag; 689 struct frag_hdr *fh; 690 unsigned int len; 691 692 len = state->left; 693 /* IF: it doesn't fit, use 'mtu' - the data space left */ 694 if (len > state->mtu) 695 len = state->mtu; 696 /* IF: we are not sending up to and including the packet end 697 then align the next start on an eight byte boundary */ 698 if (len < state->left) 699 len &= ~7; 700 701 /* Allocate buffer */ 702 frag = alloc_skb(len + state->hlen + sizeof(struct frag_hdr) + 703 state->hroom + state->troom, GFP_ATOMIC); 704 if (!frag) 705 return ERR_PTR(-ENOMEM); 706 707 /* 708 * Set up data on packet 709 */ 710 711 ip6_copy_metadata(frag, skb); 712 skb_reserve(frag, state->hroom); 713 skb_put(frag, len + state->hlen + sizeof(struct frag_hdr)); 714 skb_reset_network_header(frag); 715 fh = (struct frag_hdr *)(skb_network_header(frag) + state->hlen); 716 frag->transport_header = (frag->network_header + state->hlen + 717 sizeof(struct frag_hdr)); 718 719 /* 720 * Charge the memory for the fragment to any owner 721 * it might possess 722 */ 723 if (skb->sk) 724 skb_set_owner_w(frag, skb->sk); 725 726 /* 727 * Copy the packet header into the new buffer. 728 */ 729 skb_copy_from_linear_data(skb, skb_network_header(frag), state->hlen); 730 731 fragnexthdr_offset = skb_network_header(frag); 732 fragnexthdr_offset += prevhdr - skb_network_header(skb); 733 *fragnexthdr_offset = NEXTHDR_FRAGMENT; 734 735 /* 736 * Build fragment header. 737 */ 738 fh->nexthdr = state->nexthdr; 739 fh->reserved = 0; 740 fh->identification = state->frag_id; 741 742 /* 743 * Copy a block of the IP datagram. 744 */ 745 BUG_ON(skb_copy_bits(skb, state->ptr, skb_transport_header(frag), 746 len)); 747 state->left -= len; 748 749 fh->frag_off = htons(state->offset); 750 if (state->left > 0) 751 fh->frag_off |= htons(IP6_MF); 752 ipv6_hdr(frag)->payload_len = htons(frag->len - sizeof(struct ipv6hdr)); 753 754 state->ptr += len; 755 state->offset += len; 756 757 return frag; 758 } 759 EXPORT_SYMBOL(ip6_frag_next); 760 761 int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, 762 int (*output)(struct net *, struct sock *, struct sk_buff *)) 763 { 764 struct sk_buff *frag; 765 struct rt6_info *rt = (struct rt6_info *)skb_dst(skb); 766 struct ipv6_pinfo *np = skb->sk && !dev_recursion_level() ? 767 inet6_sk(skb->sk) : NULL; 768 struct ip6_frag_state state; 769 unsigned int mtu, hlen, nexthdr_offset; 770 ktime_t tstamp = skb->tstamp; 771 int hroom, err = 0; 772 __be32 frag_id; 773 u8 *prevhdr, nexthdr = 0; 774 775 err = ip6_find_1stfragopt(skb, &prevhdr); 776 if (err < 0) 777 goto fail; 778 hlen = err; 779 nexthdr = *prevhdr; 780 nexthdr_offset = prevhdr - skb_network_header(skb); 781 782 mtu = ip6_skb_dst_mtu(skb); 783 784 /* We must not fragment if the socket is set to force MTU discovery 785 * or if the skb it not generated by a local socket. 786 */ 787 if (unlikely(!skb->ignore_df && skb->len > mtu)) 788 goto fail_toobig; 789 790 if (IP6CB(skb)->frag_max_size) { 791 if (IP6CB(skb)->frag_max_size > mtu) 792 goto fail_toobig; 793 794 /* don't send fragments larger than what we received */ 795 mtu = IP6CB(skb)->frag_max_size; 796 if (mtu < IPV6_MIN_MTU) 797 mtu = IPV6_MIN_MTU; 798 } 799 800 if (np && np->frag_size < mtu) { 801 if (np->frag_size) 802 mtu = np->frag_size; 803 } 804 if (mtu < hlen + sizeof(struct frag_hdr) + 8) 805 goto fail_toobig; 806 mtu -= hlen + sizeof(struct frag_hdr); 807 808 frag_id = ipv6_select_ident(net, &ipv6_hdr(skb)->daddr, 809 &ipv6_hdr(skb)->saddr); 810 811 if (skb->ip_summed == CHECKSUM_PARTIAL && 812 (err = skb_checksum_help(skb))) 813 goto fail; 814 815 prevhdr = skb_network_header(skb) + nexthdr_offset; 816 hroom = LL_RESERVED_SPACE(rt->dst.dev); 817 if (skb_has_frag_list(skb)) { 818 unsigned int first_len = skb_pagelen(skb); 819 struct ip6_fraglist_iter iter; 820 struct sk_buff *frag2; 821 822 if (first_len - hlen > mtu || 823 ((first_len - hlen) & 7) || 824 skb_cloned(skb) || 825 skb_headroom(skb) < (hroom + sizeof(struct frag_hdr))) 826 goto slow_path; 827 828 skb_walk_frags(skb, frag) { 829 /* Correct geometry. */ 830 if (frag->len > mtu || 831 ((frag->len & 7) && frag->next) || 832 skb_headroom(frag) < (hlen + hroom + sizeof(struct frag_hdr))) 833 goto slow_path_clean; 834 835 /* Partially cloned skb? */ 836 if (skb_shared(frag)) 837 goto slow_path_clean; 838 839 BUG_ON(frag->sk); 840 if (skb->sk) { 841 frag->sk = skb->sk; 842 frag->destructor = sock_wfree; 843 } 844 skb->truesize -= frag->truesize; 845 } 846 847 err = ip6_fraglist_init(skb, hlen, prevhdr, nexthdr, frag_id, 848 &iter); 849 if (err < 0) 850 goto fail; 851 852 for (;;) { 853 /* Prepare header of the next frame, 854 * before previous one went down. */ 855 if (iter.frag) 856 ip6_fraglist_prepare(skb, &iter); 857 858 skb->tstamp = tstamp; 859 err = output(net, sk, skb); 860 if (!err) 861 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst), 862 IPSTATS_MIB_FRAGCREATES); 863 864 if (err || !iter.frag) 865 break; 866 867 skb = ip6_fraglist_next(&iter); 868 } 869 870 kfree(iter.tmp_hdr); 871 872 if (err == 0) { 873 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst), 874 IPSTATS_MIB_FRAGOKS); 875 return 0; 876 } 877 878 kfree_skb_list(iter.frag); 879 880 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst), 881 IPSTATS_MIB_FRAGFAILS); 882 return err; 883 884 slow_path_clean: 885 skb_walk_frags(skb, frag2) { 886 if (frag2 == frag) 887 break; 888 frag2->sk = NULL; 889 frag2->destructor = NULL; 890 skb->truesize += frag2->truesize; 891 } 892 } 893 894 slow_path: 895 /* 896 * Fragment the datagram. 897 */ 898 899 ip6_frag_init(skb, hlen, mtu, rt->dst.dev->needed_tailroom, 900 LL_RESERVED_SPACE(rt->dst.dev), prevhdr, nexthdr, frag_id, 901 &state); 902 903 /* 904 * Keep copying data until we run out. 905 */ 906 907 while (state.left > 0) { 908 frag = ip6_frag_next(skb, &state); 909 if (IS_ERR(frag)) { 910 err = PTR_ERR(frag); 911 goto fail; 912 } 913 914 /* 915 * Put this fragment into the sending queue. 916 */ 917 frag->tstamp = tstamp; 918 err = output(net, sk, frag); 919 if (err) 920 goto fail; 921 922 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 923 IPSTATS_MIB_FRAGCREATES); 924 } 925 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 926 IPSTATS_MIB_FRAGOKS); 927 consume_skb(skb); 928 return err; 929 930 fail_toobig: 931 if (skb->sk && dst_allfrag(skb_dst(skb))) 932 sk_nocaps_add(skb->sk, NETIF_F_GSO_MASK); 933 934 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 935 err = -EMSGSIZE; 936 937 fail: 938 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 939 IPSTATS_MIB_FRAGFAILS); 940 kfree_skb(skb); 941 return err; 942 } 943 944 static inline int ip6_rt_check(const struct rt6key *rt_key, 945 const struct in6_addr *fl_addr, 946 const struct in6_addr *addr_cache) 947 { 948 return (rt_key->plen != 128 || !ipv6_addr_equal(fl_addr, &rt_key->addr)) && 949 (!addr_cache || !ipv6_addr_equal(fl_addr, addr_cache)); 950 } 951 952 static struct dst_entry *ip6_sk_dst_check(struct sock *sk, 953 struct dst_entry *dst, 954 const struct flowi6 *fl6) 955 { 956 struct ipv6_pinfo *np = inet6_sk(sk); 957 struct rt6_info *rt; 958 959 if (!dst) 960 goto out; 961 962 if (dst->ops->family != AF_INET6) { 963 dst_release(dst); 964 return NULL; 965 } 966 967 rt = (struct rt6_info *)dst; 968 /* Yes, checking route validity in not connected 969 * case is not very simple. Take into account, 970 * that we do not support routing by source, TOS, 971 * and MSG_DONTROUTE --ANK (980726) 972 * 973 * 1. ip6_rt_check(): If route was host route, 974 * check that cached destination is current. 975 * If it is network route, we still may 976 * check its validity using saved pointer 977 * to the last used address: daddr_cache. 978 * We do not want to save whole address now, 979 * (because main consumer of this service 980 * is tcp, which has not this problem), 981 * so that the last trick works only on connected 982 * sockets. 983 * 2. oif also should be the same. 984 */ 985 if (ip6_rt_check(&rt->rt6i_dst, &fl6->daddr, np->daddr_cache) || 986 #ifdef CONFIG_IPV6_SUBTREES 987 ip6_rt_check(&rt->rt6i_src, &fl6->saddr, np->saddr_cache) || 988 #endif 989 (!(fl6->flowi6_flags & FLOWI_FLAG_SKIP_NH_OIF) && 990 (fl6->flowi6_oif && fl6->flowi6_oif != dst->dev->ifindex))) { 991 dst_release(dst); 992 dst = NULL; 993 } 994 995 out: 996 return dst; 997 } 998 999 static int ip6_dst_lookup_tail(struct net *net, const struct sock *sk, 1000 struct dst_entry **dst, struct flowi6 *fl6) 1001 { 1002 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD 1003 struct neighbour *n; 1004 struct rt6_info *rt; 1005 #endif 1006 int err; 1007 int flags = 0; 1008 1009 /* The correct way to handle this would be to do 1010 * ip6_route_get_saddr, and then ip6_route_output; however, 1011 * the route-specific preferred source forces the 1012 * ip6_route_output call _before_ ip6_route_get_saddr. 1013 * 1014 * In source specific routing (no src=any default route), 1015 * ip6_route_output will fail given src=any saddr, though, so 1016 * that's why we try it again later. 1017 */ 1018 if (ipv6_addr_any(&fl6->saddr) && (!*dst || !(*dst)->error)) { 1019 struct fib6_info *from; 1020 struct rt6_info *rt; 1021 bool had_dst = *dst != NULL; 1022 1023 if (!had_dst) 1024 *dst = ip6_route_output(net, sk, fl6); 1025 rt = (*dst)->error ? NULL : (struct rt6_info *)*dst; 1026 1027 rcu_read_lock(); 1028 from = rt ? rcu_dereference(rt->from) : NULL; 1029 err = ip6_route_get_saddr(net, from, &fl6->daddr, 1030 sk ? inet6_sk(sk)->srcprefs : 0, 1031 &fl6->saddr); 1032 rcu_read_unlock(); 1033 1034 if (err) 1035 goto out_err_release; 1036 1037 /* If we had an erroneous initial result, pretend it 1038 * never existed and let the SA-enabled version take 1039 * over. 1040 */ 1041 if (!had_dst && (*dst)->error) { 1042 dst_release(*dst); 1043 *dst = NULL; 1044 } 1045 1046 if (fl6->flowi6_oif) 1047 flags |= RT6_LOOKUP_F_IFACE; 1048 } 1049 1050 if (!*dst) 1051 *dst = ip6_route_output_flags(net, sk, fl6, flags); 1052 1053 err = (*dst)->error; 1054 if (err) 1055 goto out_err_release; 1056 1057 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD 1058 /* 1059 * Here if the dst entry we've looked up 1060 * has a neighbour entry that is in the INCOMPLETE 1061 * state and the src address from the flow is 1062 * marked as OPTIMISTIC, we release the found 1063 * dst entry and replace it instead with the 1064 * dst entry of the nexthop router 1065 */ 1066 rt = (struct rt6_info *) *dst; 1067 rcu_read_lock_bh(); 1068 n = __ipv6_neigh_lookup_noref(rt->dst.dev, 1069 rt6_nexthop(rt, &fl6->daddr)); 1070 err = n && !(n->nud_state & NUD_VALID) ? -EINVAL : 0; 1071 rcu_read_unlock_bh(); 1072 1073 if (err) { 1074 struct inet6_ifaddr *ifp; 1075 struct flowi6 fl_gw6; 1076 int redirect; 1077 1078 ifp = ipv6_get_ifaddr(net, &fl6->saddr, 1079 (*dst)->dev, 1); 1080 1081 redirect = (ifp && ifp->flags & IFA_F_OPTIMISTIC); 1082 if (ifp) 1083 in6_ifa_put(ifp); 1084 1085 if (redirect) { 1086 /* 1087 * We need to get the dst entry for the 1088 * default router instead 1089 */ 1090 dst_release(*dst); 1091 memcpy(&fl_gw6, fl6, sizeof(struct flowi6)); 1092 memset(&fl_gw6.daddr, 0, sizeof(struct in6_addr)); 1093 *dst = ip6_route_output(net, sk, &fl_gw6); 1094 err = (*dst)->error; 1095 if (err) 1096 goto out_err_release; 1097 } 1098 } 1099 #endif 1100 if (ipv6_addr_v4mapped(&fl6->saddr) && 1101 !(ipv6_addr_v4mapped(&fl6->daddr) || ipv6_addr_any(&fl6->daddr))) { 1102 err = -EAFNOSUPPORT; 1103 goto out_err_release; 1104 } 1105 1106 return 0; 1107 1108 out_err_release: 1109 dst_release(*dst); 1110 *dst = NULL; 1111 1112 if (err == -ENETUNREACH) 1113 IP6_INC_STATS(net, NULL, IPSTATS_MIB_OUTNOROUTES); 1114 return err; 1115 } 1116 1117 /** 1118 * ip6_dst_lookup - perform route lookup on flow 1119 * @net: Network namespace to perform lookup in 1120 * @sk: socket which provides route info 1121 * @dst: pointer to dst_entry * for result 1122 * @fl6: flow to lookup 1123 * 1124 * This function performs a route lookup on the given flow. 1125 * 1126 * It returns zero on success, or a standard errno code on error. 1127 */ 1128 int ip6_dst_lookup(struct net *net, struct sock *sk, struct dst_entry **dst, 1129 struct flowi6 *fl6) 1130 { 1131 *dst = NULL; 1132 return ip6_dst_lookup_tail(net, sk, dst, fl6); 1133 } 1134 EXPORT_SYMBOL_GPL(ip6_dst_lookup); 1135 1136 /** 1137 * ip6_dst_lookup_flow - perform route lookup on flow with ipsec 1138 * @net: Network namespace to perform lookup in 1139 * @sk: socket which provides route info 1140 * @fl6: flow to lookup 1141 * @final_dst: final destination address for ipsec lookup 1142 * 1143 * This function performs a route lookup on the given flow. 1144 * 1145 * It returns a valid dst pointer on success, or a pointer encoded 1146 * error code. 1147 */ 1148 struct dst_entry *ip6_dst_lookup_flow(struct net *net, const struct sock *sk, struct flowi6 *fl6, 1149 const struct in6_addr *final_dst) 1150 { 1151 struct dst_entry *dst = NULL; 1152 int err; 1153 1154 err = ip6_dst_lookup_tail(net, sk, &dst, fl6); 1155 if (err) 1156 return ERR_PTR(err); 1157 if (final_dst) 1158 fl6->daddr = *final_dst; 1159 1160 return xfrm_lookup_route(net, dst, flowi6_to_flowi(fl6), sk, 0); 1161 } 1162 EXPORT_SYMBOL_GPL(ip6_dst_lookup_flow); 1163 1164 /** 1165 * ip6_sk_dst_lookup_flow - perform socket cached route lookup on flow 1166 * @sk: socket which provides the dst cache and route info 1167 * @fl6: flow to lookup 1168 * @final_dst: final destination address for ipsec lookup 1169 * @connected: whether @sk is connected or not 1170 * 1171 * This function performs a route lookup on the given flow with the 1172 * possibility of using the cached route in the socket if it is valid. 1173 * It will take the socket dst lock when operating on the dst cache. 1174 * As a result, this function can only be used in process context. 1175 * 1176 * In addition, for a connected socket, cache the dst in the socket 1177 * if the current cache is not valid. 1178 * 1179 * It returns a valid dst pointer on success, or a pointer encoded 1180 * error code. 1181 */ 1182 struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6, 1183 const struct in6_addr *final_dst, 1184 bool connected) 1185 { 1186 struct dst_entry *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie); 1187 1188 dst = ip6_sk_dst_check(sk, dst, fl6); 1189 if (dst) 1190 return dst; 1191 1192 dst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_dst); 1193 if (connected && !IS_ERR(dst)) 1194 ip6_sk_dst_store_flow(sk, dst_clone(dst), fl6); 1195 1196 return dst; 1197 } 1198 EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup_flow); 1199 1200 /** 1201 * ip6_dst_lookup_tunnel - perform route lookup on tunnel 1202 * @skb: Packet for which lookup is done 1203 * @dev: Tunnel device 1204 * @net: Network namespace of tunnel device 1205 * @sock: Socket which provides route info 1206 * @saddr: Memory to store the src ip address 1207 * @info: Tunnel information 1208 * @protocol: IP protocol 1209 * @use_cache: Flag to enable cache usage 1210 * This function performs a route lookup on a tunnel 1211 * 1212 * It returns a valid dst pointer and stores src address to be used in 1213 * tunnel in param saddr on success, else a pointer encoded error code. 1214 */ 1215 1216 struct dst_entry *ip6_dst_lookup_tunnel(struct sk_buff *skb, 1217 struct net_device *dev, 1218 struct net *net, 1219 struct socket *sock, 1220 struct in6_addr *saddr, 1221 const struct ip_tunnel_info *info, 1222 u8 protocol, 1223 bool use_cache) 1224 { 1225 struct dst_entry *dst = NULL; 1226 #ifdef CONFIG_DST_CACHE 1227 struct dst_cache *dst_cache; 1228 #endif 1229 struct flowi6 fl6; 1230 __u8 prio; 1231 1232 #ifdef CONFIG_DST_CACHE 1233 dst_cache = (struct dst_cache *)&info->dst_cache; 1234 if (use_cache) { 1235 dst = dst_cache_get_ip6(dst_cache, saddr); 1236 if (dst) 1237 return dst; 1238 } 1239 #endif 1240 memset(&fl6, 0, sizeof(fl6)); 1241 fl6.flowi6_mark = skb->mark; 1242 fl6.flowi6_proto = protocol; 1243 fl6.daddr = info->key.u.ipv6.dst; 1244 fl6.saddr = info->key.u.ipv6.src; 1245 prio = info->key.tos; 1246 fl6.flowlabel = ip6_make_flowinfo(RT_TOS(prio), 1247 info->key.label); 1248 1249 dst = ipv6_stub->ipv6_dst_lookup_flow(net, sock->sk, &fl6, 1250 NULL); 1251 if (IS_ERR(dst)) { 1252 netdev_dbg(dev, "no route to %pI6\n", &fl6.daddr); 1253 return ERR_PTR(-ENETUNREACH); 1254 } 1255 if (dst->dev == dev) { /* is this necessary? */ 1256 netdev_dbg(dev, "circular route to %pI6\n", &fl6.daddr); 1257 dst_release(dst); 1258 return ERR_PTR(-ELOOP); 1259 } 1260 #ifdef CONFIG_DST_CACHE 1261 if (use_cache) 1262 dst_cache_set_ip6(dst_cache, dst, &fl6.saddr); 1263 #endif 1264 *saddr = fl6.saddr; 1265 return dst; 1266 } 1267 EXPORT_SYMBOL_GPL(ip6_dst_lookup_tunnel); 1268 1269 static inline struct ipv6_opt_hdr *ip6_opt_dup(struct ipv6_opt_hdr *src, 1270 gfp_t gfp) 1271 { 1272 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL; 1273 } 1274 1275 static inline struct ipv6_rt_hdr *ip6_rthdr_dup(struct ipv6_rt_hdr *src, 1276 gfp_t gfp) 1277 { 1278 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL; 1279 } 1280 1281 static void ip6_append_data_mtu(unsigned int *mtu, 1282 int *maxfraglen, 1283 unsigned int fragheaderlen, 1284 struct sk_buff *skb, 1285 struct rt6_info *rt, 1286 unsigned int orig_mtu) 1287 { 1288 if (!(rt->dst.flags & DST_XFRM_TUNNEL)) { 1289 if (!skb) { 1290 /* first fragment, reserve header_len */ 1291 *mtu = orig_mtu - rt->dst.header_len; 1292 1293 } else { 1294 /* 1295 * this fragment is not first, the headers 1296 * space is regarded as data space. 1297 */ 1298 *mtu = orig_mtu; 1299 } 1300 *maxfraglen = ((*mtu - fragheaderlen) & ~7) 1301 + fragheaderlen - sizeof(struct frag_hdr); 1302 } 1303 } 1304 1305 static int ip6_setup_cork(struct sock *sk, struct inet_cork_full *cork, 1306 struct inet6_cork *v6_cork, struct ipcm6_cookie *ipc6, 1307 struct rt6_info *rt, struct flowi6 *fl6) 1308 { 1309 struct ipv6_pinfo *np = inet6_sk(sk); 1310 unsigned int mtu; 1311 struct ipv6_txoptions *opt = ipc6->opt; 1312 1313 /* 1314 * setup for corking 1315 */ 1316 if (opt) { 1317 if (WARN_ON(v6_cork->opt)) 1318 return -EINVAL; 1319 1320 v6_cork->opt = kzalloc(sizeof(*opt), sk->sk_allocation); 1321 if (unlikely(!v6_cork->opt)) 1322 return -ENOBUFS; 1323 1324 v6_cork->opt->tot_len = sizeof(*opt); 1325 v6_cork->opt->opt_flen = opt->opt_flen; 1326 v6_cork->opt->opt_nflen = opt->opt_nflen; 1327 1328 v6_cork->opt->dst0opt = ip6_opt_dup(opt->dst0opt, 1329 sk->sk_allocation); 1330 if (opt->dst0opt && !v6_cork->opt->dst0opt) 1331 return -ENOBUFS; 1332 1333 v6_cork->opt->dst1opt = ip6_opt_dup(opt->dst1opt, 1334 sk->sk_allocation); 1335 if (opt->dst1opt && !v6_cork->opt->dst1opt) 1336 return -ENOBUFS; 1337 1338 v6_cork->opt->hopopt = ip6_opt_dup(opt->hopopt, 1339 sk->sk_allocation); 1340 if (opt->hopopt && !v6_cork->opt->hopopt) 1341 return -ENOBUFS; 1342 1343 v6_cork->opt->srcrt = ip6_rthdr_dup(opt->srcrt, 1344 sk->sk_allocation); 1345 if (opt->srcrt && !v6_cork->opt->srcrt) 1346 return -ENOBUFS; 1347 1348 /* need source address above miyazawa*/ 1349 } 1350 dst_hold(&rt->dst); 1351 cork->base.dst = &rt->dst; 1352 cork->fl.u.ip6 = *fl6; 1353 v6_cork->hop_limit = ipc6->hlimit; 1354 v6_cork->tclass = ipc6->tclass; 1355 if (rt->dst.flags & DST_XFRM_TUNNEL) 1356 mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ? 1357 READ_ONCE(rt->dst.dev->mtu) : dst_mtu(&rt->dst); 1358 else 1359 mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ? 1360 READ_ONCE(rt->dst.dev->mtu) : dst_mtu(xfrm_dst_path(&rt->dst)); 1361 if (np->frag_size < mtu) { 1362 if (np->frag_size) 1363 mtu = np->frag_size; 1364 } 1365 if (mtu < IPV6_MIN_MTU) 1366 return -EINVAL; 1367 cork->base.fragsize = mtu; 1368 cork->base.gso_size = ipc6->gso_size; 1369 cork->base.tx_flags = 0; 1370 cork->base.mark = ipc6->sockc.mark; 1371 sock_tx_timestamp(sk, ipc6->sockc.tsflags, &cork->base.tx_flags); 1372 1373 if (dst_allfrag(xfrm_dst_path(&rt->dst))) 1374 cork->base.flags |= IPCORK_ALLFRAG; 1375 cork->base.length = 0; 1376 1377 cork->base.transmit_time = ipc6->sockc.transmit_time; 1378 1379 return 0; 1380 } 1381 1382 static int __ip6_append_data(struct sock *sk, 1383 struct flowi6 *fl6, 1384 struct sk_buff_head *queue, 1385 struct inet_cork *cork, 1386 struct inet6_cork *v6_cork, 1387 struct page_frag *pfrag, 1388 int getfrag(void *from, char *to, int offset, 1389 int len, int odd, struct sk_buff *skb), 1390 void *from, int length, int transhdrlen, 1391 unsigned int flags, struct ipcm6_cookie *ipc6) 1392 { 1393 struct sk_buff *skb, *skb_prev = NULL; 1394 unsigned int maxfraglen, fragheaderlen, mtu, orig_mtu, pmtu; 1395 struct ubuf_info *uarg = NULL; 1396 int exthdrlen = 0; 1397 int dst_exthdrlen = 0; 1398 int hh_len; 1399 int copy; 1400 int err; 1401 int offset = 0; 1402 u32 tskey = 0; 1403 struct rt6_info *rt = (struct rt6_info *)cork->dst; 1404 struct ipv6_txoptions *opt = v6_cork->opt; 1405 int csummode = CHECKSUM_NONE; 1406 unsigned int maxnonfragsize, headersize; 1407 unsigned int wmem_alloc_delta = 0; 1408 bool paged, extra_uref = false; 1409 1410 skb = skb_peek_tail(queue); 1411 if (!skb) { 1412 exthdrlen = opt ? opt->opt_flen : 0; 1413 dst_exthdrlen = rt->dst.header_len - rt->rt6i_nfheader_len; 1414 } 1415 1416 paged = !!cork->gso_size; 1417 mtu = cork->gso_size ? IP6_MAX_MTU : cork->fragsize; 1418 orig_mtu = mtu; 1419 1420 if (cork->tx_flags & SKBTX_ANY_SW_TSTAMP && 1421 sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID) 1422 tskey = sk->sk_tskey++; 1423 1424 hh_len = LL_RESERVED_SPACE(rt->dst.dev); 1425 1426 fragheaderlen = sizeof(struct ipv6hdr) + rt->rt6i_nfheader_len + 1427 (opt ? opt->opt_nflen : 0); 1428 maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - 1429 sizeof(struct frag_hdr); 1430 1431 headersize = sizeof(struct ipv6hdr) + 1432 (opt ? opt->opt_flen + opt->opt_nflen : 0) + 1433 (dst_allfrag(&rt->dst) ? 1434 sizeof(struct frag_hdr) : 0) + 1435 rt->rt6i_nfheader_len; 1436 1437 /* as per RFC 7112 section 5, the entire IPv6 Header Chain must fit 1438 * the first fragment 1439 */ 1440 if (headersize + transhdrlen > mtu) 1441 goto emsgsize; 1442 1443 if (cork->length + length > mtu - headersize && ipc6->dontfrag && 1444 (sk->sk_protocol == IPPROTO_UDP || 1445 sk->sk_protocol == IPPROTO_RAW)) { 1446 ipv6_local_rxpmtu(sk, fl6, mtu - headersize + 1447 sizeof(struct ipv6hdr)); 1448 goto emsgsize; 1449 } 1450 1451 if (ip6_sk_ignore_df(sk)) 1452 maxnonfragsize = sizeof(struct ipv6hdr) + IPV6_MAXPLEN; 1453 else 1454 maxnonfragsize = mtu; 1455 1456 if (cork->length + length > maxnonfragsize - headersize) { 1457 emsgsize: 1458 pmtu = max_t(int, mtu - headersize + sizeof(struct ipv6hdr), 0); 1459 ipv6_local_error(sk, EMSGSIZE, fl6, pmtu); 1460 return -EMSGSIZE; 1461 } 1462 1463 /* CHECKSUM_PARTIAL only with no extension headers and when 1464 * we are not going to fragment 1465 */ 1466 if (transhdrlen && sk->sk_protocol == IPPROTO_UDP && 1467 headersize == sizeof(struct ipv6hdr) && 1468 length <= mtu - headersize && 1469 (!(flags & MSG_MORE) || cork->gso_size) && 1470 rt->dst.dev->features & (NETIF_F_IPV6_CSUM | NETIF_F_HW_CSUM)) 1471 csummode = CHECKSUM_PARTIAL; 1472 1473 if (flags & MSG_ZEROCOPY && length && sock_flag(sk, SOCK_ZEROCOPY)) { 1474 uarg = sock_zerocopy_realloc(sk, length, skb_zcopy(skb)); 1475 if (!uarg) 1476 return -ENOBUFS; 1477 extra_uref = !skb_zcopy(skb); /* only ref on new uarg */ 1478 if (rt->dst.dev->features & NETIF_F_SG && 1479 csummode == CHECKSUM_PARTIAL) { 1480 paged = true; 1481 } else { 1482 uarg->zerocopy = 0; 1483 skb_zcopy_set(skb, uarg, &extra_uref); 1484 } 1485 } 1486 1487 /* 1488 * Let's try using as much space as possible. 1489 * Use MTU if total length of the message fits into the MTU. 1490 * Otherwise, we need to reserve fragment header and 1491 * fragment alignment (= 8-15 octects, in total). 1492 * 1493 * Note that we may need to "move" the data from the tail 1494 * of the buffer to the new fragment when we split 1495 * the message. 1496 * 1497 * FIXME: It may be fragmented into multiple chunks 1498 * at once if non-fragmentable extension headers 1499 * are too large. 1500 * --yoshfuji 1501 */ 1502 1503 cork->length += length; 1504 if (!skb) 1505 goto alloc_new_skb; 1506 1507 while (length > 0) { 1508 /* Check if the remaining data fits into current packet. */ 1509 copy = (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len; 1510 if (copy < length) 1511 copy = maxfraglen - skb->len; 1512 1513 if (copy <= 0) { 1514 char *data; 1515 unsigned int datalen; 1516 unsigned int fraglen; 1517 unsigned int fraggap; 1518 unsigned int alloclen; 1519 unsigned int pagedlen; 1520 alloc_new_skb: 1521 /* There's no room in the current skb */ 1522 if (skb) 1523 fraggap = skb->len - maxfraglen; 1524 else 1525 fraggap = 0; 1526 /* update mtu and maxfraglen if necessary */ 1527 if (!skb || !skb_prev) 1528 ip6_append_data_mtu(&mtu, &maxfraglen, 1529 fragheaderlen, skb, rt, 1530 orig_mtu); 1531 1532 skb_prev = skb; 1533 1534 /* 1535 * If remaining data exceeds the mtu, 1536 * we know we need more fragment(s). 1537 */ 1538 datalen = length + fraggap; 1539 1540 if (datalen > (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen) 1541 datalen = maxfraglen - fragheaderlen - rt->dst.trailer_len; 1542 fraglen = datalen + fragheaderlen; 1543 pagedlen = 0; 1544 1545 if ((flags & MSG_MORE) && 1546 !(rt->dst.dev->features&NETIF_F_SG)) 1547 alloclen = mtu; 1548 else if (!paged) 1549 alloclen = fraglen; 1550 else { 1551 alloclen = min_t(int, fraglen, MAX_HEADER); 1552 pagedlen = fraglen - alloclen; 1553 } 1554 1555 alloclen += dst_exthdrlen; 1556 1557 if (datalen != length + fraggap) { 1558 /* 1559 * this is not the last fragment, the trailer 1560 * space is regarded as data space. 1561 */ 1562 datalen += rt->dst.trailer_len; 1563 } 1564 1565 alloclen += rt->dst.trailer_len; 1566 fraglen = datalen + fragheaderlen; 1567 1568 /* 1569 * We just reserve space for fragment header. 1570 * Note: this may be overallocation if the message 1571 * (without MSG_MORE) fits into the MTU. 1572 */ 1573 alloclen += sizeof(struct frag_hdr); 1574 1575 copy = datalen - transhdrlen - fraggap - pagedlen; 1576 if (copy < 0) { 1577 err = -EINVAL; 1578 goto error; 1579 } 1580 if (transhdrlen) { 1581 skb = sock_alloc_send_skb(sk, 1582 alloclen + hh_len, 1583 (flags & MSG_DONTWAIT), &err); 1584 } else { 1585 skb = NULL; 1586 if (refcount_read(&sk->sk_wmem_alloc) + wmem_alloc_delta <= 1587 2 * sk->sk_sndbuf) 1588 skb = alloc_skb(alloclen + hh_len, 1589 sk->sk_allocation); 1590 if (unlikely(!skb)) 1591 err = -ENOBUFS; 1592 } 1593 if (!skb) 1594 goto error; 1595 /* 1596 * Fill in the control structures 1597 */ 1598 skb->protocol = htons(ETH_P_IPV6); 1599 skb->ip_summed = csummode; 1600 skb->csum = 0; 1601 /* reserve for fragmentation and ipsec header */ 1602 skb_reserve(skb, hh_len + sizeof(struct frag_hdr) + 1603 dst_exthdrlen); 1604 1605 /* 1606 * Find where to start putting bytes 1607 */ 1608 data = skb_put(skb, fraglen - pagedlen); 1609 skb_set_network_header(skb, exthdrlen); 1610 data += fragheaderlen; 1611 skb->transport_header = (skb->network_header + 1612 fragheaderlen); 1613 if (fraggap) { 1614 skb->csum = skb_copy_and_csum_bits( 1615 skb_prev, maxfraglen, 1616 data + transhdrlen, fraggap); 1617 skb_prev->csum = csum_sub(skb_prev->csum, 1618 skb->csum); 1619 data += fraggap; 1620 pskb_trim_unique(skb_prev, maxfraglen); 1621 } 1622 if (copy > 0 && 1623 getfrag(from, data + transhdrlen, offset, 1624 copy, fraggap, skb) < 0) { 1625 err = -EFAULT; 1626 kfree_skb(skb); 1627 goto error; 1628 } 1629 1630 offset += copy; 1631 length -= copy + transhdrlen; 1632 transhdrlen = 0; 1633 exthdrlen = 0; 1634 dst_exthdrlen = 0; 1635 1636 /* Only the initial fragment is time stamped */ 1637 skb_shinfo(skb)->tx_flags = cork->tx_flags; 1638 cork->tx_flags = 0; 1639 skb_shinfo(skb)->tskey = tskey; 1640 tskey = 0; 1641 skb_zcopy_set(skb, uarg, &extra_uref); 1642 1643 if ((flags & MSG_CONFIRM) && !skb_prev) 1644 skb_set_dst_pending_confirm(skb, 1); 1645 1646 /* 1647 * Put the packet on the pending queue 1648 */ 1649 if (!skb->destructor) { 1650 skb->destructor = sock_wfree; 1651 skb->sk = sk; 1652 wmem_alloc_delta += skb->truesize; 1653 } 1654 __skb_queue_tail(queue, skb); 1655 continue; 1656 } 1657 1658 if (copy > length) 1659 copy = length; 1660 1661 if (!(rt->dst.dev->features&NETIF_F_SG) && 1662 skb_tailroom(skb) >= copy) { 1663 unsigned int off; 1664 1665 off = skb->len; 1666 if (getfrag(from, skb_put(skb, copy), 1667 offset, copy, off, skb) < 0) { 1668 __skb_trim(skb, off); 1669 err = -EFAULT; 1670 goto error; 1671 } 1672 } else if (!uarg || !uarg->zerocopy) { 1673 int i = skb_shinfo(skb)->nr_frags; 1674 1675 err = -ENOMEM; 1676 if (!sk_page_frag_refill(sk, pfrag)) 1677 goto error; 1678 1679 if (!skb_can_coalesce(skb, i, pfrag->page, 1680 pfrag->offset)) { 1681 err = -EMSGSIZE; 1682 if (i == MAX_SKB_FRAGS) 1683 goto error; 1684 1685 __skb_fill_page_desc(skb, i, pfrag->page, 1686 pfrag->offset, 0); 1687 skb_shinfo(skb)->nr_frags = ++i; 1688 get_page(pfrag->page); 1689 } 1690 copy = min_t(int, copy, pfrag->size - pfrag->offset); 1691 if (getfrag(from, 1692 page_address(pfrag->page) + pfrag->offset, 1693 offset, copy, skb->len, skb) < 0) 1694 goto error_efault; 1695 1696 pfrag->offset += copy; 1697 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); 1698 skb->len += copy; 1699 skb->data_len += copy; 1700 skb->truesize += copy; 1701 wmem_alloc_delta += copy; 1702 } else { 1703 err = skb_zerocopy_iter_dgram(skb, from, copy); 1704 if (err < 0) 1705 goto error; 1706 } 1707 offset += copy; 1708 length -= copy; 1709 } 1710 1711 if (wmem_alloc_delta) 1712 refcount_add(wmem_alloc_delta, &sk->sk_wmem_alloc); 1713 return 0; 1714 1715 error_efault: 1716 err = -EFAULT; 1717 error: 1718 if (uarg) 1719 sock_zerocopy_put_abort(uarg, extra_uref); 1720 cork->length -= length; 1721 IP6_INC_STATS(sock_net(sk), rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS); 1722 refcount_add(wmem_alloc_delta, &sk->sk_wmem_alloc); 1723 return err; 1724 } 1725 1726 int ip6_append_data(struct sock *sk, 1727 int getfrag(void *from, char *to, int offset, int len, 1728 int odd, struct sk_buff *skb), 1729 void *from, int length, int transhdrlen, 1730 struct ipcm6_cookie *ipc6, struct flowi6 *fl6, 1731 struct rt6_info *rt, unsigned int flags) 1732 { 1733 struct inet_sock *inet = inet_sk(sk); 1734 struct ipv6_pinfo *np = inet6_sk(sk); 1735 int exthdrlen; 1736 int err; 1737 1738 if (flags&MSG_PROBE) 1739 return 0; 1740 if (skb_queue_empty(&sk->sk_write_queue)) { 1741 /* 1742 * setup for corking 1743 */ 1744 err = ip6_setup_cork(sk, &inet->cork, &np->cork, 1745 ipc6, rt, fl6); 1746 if (err) 1747 return err; 1748 1749 exthdrlen = (ipc6->opt ? ipc6->opt->opt_flen : 0); 1750 length += exthdrlen; 1751 transhdrlen += exthdrlen; 1752 } else { 1753 fl6 = &inet->cork.fl.u.ip6; 1754 transhdrlen = 0; 1755 } 1756 1757 return __ip6_append_data(sk, fl6, &sk->sk_write_queue, &inet->cork.base, 1758 &np->cork, sk_page_frag(sk), getfrag, 1759 from, length, transhdrlen, flags, ipc6); 1760 } 1761 EXPORT_SYMBOL_GPL(ip6_append_data); 1762 1763 static void ip6_cork_release(struct inet_cork_full *cork, 1764 struct inet6_cork *v6_cork) 1765 { 1766 if (v6_cork->opt) { 1767 kfree(v6_cork->opt->dst0opt); 1768 kfree(v6_cork->opt->dst1opt); 1769 kfree(v6_cork->opt->hopopt); 1770 kfree(v6_cork->opt->srcrt); 1771 kfree(v6_cork->opt); 1772 v6_cork->opt = NULL; 1773 } 1774 1775 if (cork->base.dst) { 1776 dst_release(cork->base.dst); 1777 cork->base.dst = NULL; 1778 cork->base.flags &= ~IPCORK_ALLFRAG; 1779 } 1780 memset(&cork->fl, 0, sizeof(cork->fl)); 1781 } 1782 1783 struct sk_buff *__ip6_make_skb(struct sock *sk, 1784 struct sk_buff_head *queue, 1785 struct inet_cork_full *cork, 1786 struct inet6_cork *v6_cork) 1787 { 1788 struct sk_buff *skb, *tmp_skb; 1789 struct sk_buff **tail_skb; 1790 struct in6_addr final_dst_buf, *final_dst = &final_dst_buf; 1791 struct ipv6_pinfo *np = inet6_sk(sk); 1792 struct net *net = sock_net(sk); 1793 struct ipv6hdr *hdr; 1794 struct ipv6_txoptions *opt = v6_cork->opt; 1795 struct rt6_info *rt = (struct rt6_info *)cork->base.dst; 1796 struct flowi6 *fl6 = &cork->fl.u.ip6; 1797 unsigned char proto = fl6->flowi6_proto; 1798 1799 skb = __skb_dequeue(queue); 1800 if (!skb) 1801 goto out; 1802 tail_skb = &(skb_shinfo(skb)->frag_list); 1803 1804 /* move skb->data to ip header from ext header */ 1805 if (skb->data < skb_network_header(skb)) 1806 __skb_pull(skb, skb_network_offset(skb)); 1807 while ((tmp_skb = __skb_dequeue(queue)) != NULL) { 1808 __skb_pull(tmp_skb, skb_network_header_len(skb)); 1809 *tail_skb = tmp_skb; 1810 tail_skb = &(tmp_skb->next); 1811 skb->len += tmp_skb->len; 1812 skb->data_len += tmp_skb->len; 1813 skb->truesize += tmp_skb->truesize; 1814 tmp_skb->destructor = NULL; 1815 tmp_skb->sk = NULL; 1816 } 1817 1818 /* Allow local fragmentation. */ 1819 skb->ignore_df = ip6_sk_ignore_df(sk); 1820 1821 *final_dst = fl6->daddr; 1822 __skb_pull(skb, skb_network_header_len(skb)); 1823 if (opt && opt->opt_flen) 1824 ipv6_push_frag_opts(skb, opt, &proto); 1825 if (opt && opt->opt_nflen) 1826 ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst, &fl6->saddr); 1827 1828 skb_push(skb, sizeof(struct ipv6hdr)); 1829 skb_reset_network_header(skb); 1830 hdr = ipv6_hdr(skb); 1831 1832 ip6_flow_hdr(hdr, v6_cork->tclass, 1833 ip6_make_flowlabel(net, skb, fl6->flowlabel, 1834 ip6_autoflowlabel(net, np), fl6)); 1835 hdr->hop_limit = v6_cork->hop_limit; 1836 hdr->nexthdr = proto; 1837 hdr->saddr = fl6->saddr; 1838 hdr->daddr = *final_dst; 1839 1840 skb->priority = sk->sk_priority; 1841 skb->mark = cork->base.mark; 1842 1843 skb->tstamp = cork->base.transmit_time; 1844 1845 skb_dst_set(skb, dst_clone(&rt->dst)); 1846 IP6_UPD_PO_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUT, skb->len); 1847 if (proto == IPPROTO_ICMPV6) { 1848 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); 1849 1850 ICMP6MSGOUT_INC_STATS(net, idev, icmp6_hdr(skb)->icmp6_type); 1851 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS); 1852 } 1853 1854 ip6_cork_release(cork, v6_cork); 1855 out: 1856 return skb; 1857 } 1858 1859 int ip6_send_skb(struct sk_buff *skb) 1860 { 1861 struct net *net = sock_net(skb->sk); 1862 struct rt6_info *rt = (struct rt6_info *)skb_dst(skb); 1863 int err; 1864 1865 err = ip6_local_out(net, skb->sk, skb); 1866 if (err) { 1867 if (err > 0) 1868 err = net_xmit_errno(err); 1869 if (err) 1870 IP6_INC_STATS(net, rt->rt6i_idev, 1871 IPSTATS_MIB_OUTDISCARDS); 1872 } 1873 1874 return err; 1875 } 1876 1877 int ip6_push_pending_frames(struct sock *sk) 1878 { 1879 struct sk_buff *skb; 1880 1881 skb = ip6_finish_skb(sk); 1882 if (!skb) 1883 return 0; 1884 1885 return ip6_send_skb(skb); 1886 } 1887 EXPORT_SYMBOL_GPL(ip6_push_pending_frames); 1888 1889 static void __ip6_flush_pending_frames(struct sock *sk, 1890 struct sk_buff_head *queue, 1891 struct inet_cork_full *cork, 1892 struct inet6_cork *v6_cork) 1893 { 1894 struct sk_buff *skb; 1895 1896 while ((skb = __skb_dequeue_tail(queue)) != NULL) { 1897 if (skb_dst(skb)) 1898 IP6_INC_STATS(sock_net(sk), ip6_dst_idev(skb_dst(skb)), 1899 IPSTATS_MIB_OUTDISCARDS); 1900 kfree_skb(skb); 1901 } 1902 1903 ip6_cork_release(cork, v6_cork); 1904 } 1905 1906 void ip6_flush_pending_frames(struct sock *sk) 1907 { 1908 __ip6_flush_pending_frames(sk, &sk->sk_write_queue, 1909 &inet_sk(sk)->cork, &inet6_sk(sk)->cork); 1910 } 1911 EXPORT_SYMBOL_GPL(ip6_flush_pending_frames); 1912 1913 struct sk_buff *ip6_make_skb(struct sock *sk, 1914 int getfrag(void *from, char *to, int offset, 1915 int len, int odd, struct sk_buff *skb), 1916 void *from, int length, int transhdrlen, 1917 struct ipcm6_cookie *ipc6, struct flowi6 *fl6, 1918 struct rt6_info *rt, unsigned int flags, 1919 struct inet_cork_full *cork) 1920 { 1921 struct inet6_cork v6_cork; 1922 struct sk_buff_head queue; 1923 int exthdrlen = (ipc6->opt ? ipc6->opt->opt_flen : 0); 1924 int err; 1925 1926 if (flags & MSG_PROBE) 1927 return NULL; 1928 1929 __skb_queue_head_init(&queue); 1930 1931 cork->base.flags = 0; 1932 cork->base.addr = 0; 1933 cork->base.opt = NULL; 1934 cork->base.dst = NULL; 1935 v6_cork.opt = NULL; 1936 err = ip6_setup_cork(sk, cork, &v6_cork, ipc6, rt, fl6); 1937 if (err) { 1938 ip6_cork_release(cork, &v6_cork); 1939 return ERR_PTR(err); 1940 } 1941 if (ipc6->dontfrag < 0) 1942 ipc6->dontfrag = inet6_sk(sk)->dontfrag; 1943 1944 err = __ip6_append_data(sk, fl6, &queue, &cork->base, &v6_cork, 1945 ¤t->task_frag, getfrag, from, 1946 length + exthdrlen, transhdrlen + exthdrlen, 1947 flags, ipc6); 1948 if (err) { 1949 __ip6_flush_pending_frames(sk, &queue, cork, &v6_cork); 1950 return ERR_PTR(err); 1951 } 1952 1953 return __ip6_make_skb(sk, &queue, cork, &v6_cork); 1954 } 1955