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   1 /*
   2  *      IPv6 output functions
   3  *      Linux INET6 implementation
   4  *
   5  *      Authors:
   6  *      Pedro Roque             <roque@di.fc.ul.pt>
   7  *
   8  *      $Id: ip6_output.c,v 1.34 2002/02/01 22:01:04 davem Exp $
   9  *
  10  *      Based on linux/net/ipv4/ip_output.c
  11  *
  12  *      This program is free software; you can redistribute it and/or
  13  *      modify it under the terms of the GNU General Public License
  14  *      as published by the Free Software Foundation; either version
  15  *      2 of the License, or (at your option) any later version.
  16  *
  17  *      Changes:
  18  *      A.N.Kuznetsov   :       airthmetics in fragmentation.
  19  *                              extension headers are implemented.
  20  *                              route changes now work.
  21  *                              ip6_forward does not confuse sniffers.
  22  *                              etc.
  23  *
  24  *      H. von Brand    :       Added missing #include <linux/string.h>
  25  *      Imran Patel     :       frag id should be in NBO
  26  *      Kazunori MIYAZAWA @USAGI
  27  *                      :       add ip6_append_data and related functions
  28  *                              for datagram xmit
  29  */
  30
  31 #include <linux/errno.h>
  32 #include <linux/types.h>
  33 #include <linux/string.h>
  34 #include <linux/socket.h>
  35 #include <linux/net.h>
  36 #include <linux/netdevice.h>
  37 #include <linux/if_arp.h>
  38 #include <linux/in6.h>
  39 #include <linux/tcp.h>
  40 #include <linux/route.h>
  41 #include <linux/module.h>
  42
  43 #include <linux/netfilter.h>
  44 #include <linux/netfilter_ipv6.h>
  45
  46 #include <net/sock.h>
  47 #include <net/snmp.h>
  48
  49 #include <net/ipv6.h>
  50 #include <net/ndisc.h>
  51 #include <net/protocol.h>
  52 #include <net/ip6_route.h>
  53 #include <net/addrconf.h>
  54 #include <net/rawv6.h>
  55 #include <net/icmp.h>
  56 #include <net/xfrm.h>
  57 #include <net/checksum.h>
  58
  59 static int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *));
  60
  61 static __inline__ void ipv6_select_ident(struct sk_buff *skb, struct frag_hdr *fhdr)
  62 {
  63         static u32 ipv6_fragmentation_id = 1;
  64         static DEFINE_SPINLOCK(ip6_id_lock);
  65
  66         spin_lock_bh(&ip6_id_lock);
  67         fhdr->identification = htonl(ipv6_fragmentation_id);
  68         if (++ipv6_fragmentation_id == 0)
  69                 ipv6_fragmentation_id = 1;
  70         spin_unlock_bh(&ip6_id_lock);
  71 }
  72
  73 static inline int ip6_output_finish(struct sk_buff *skb)
  74 {
  75
  76         struct dst_entry *dst = skb->dst;
  77         struct hh_cache *hh = dst->hh;
  78
  79         if (hh) {
  80                 int hh_alen;
  81
  82                 read_lock_bh(&hh->hh_lock);
  83                 hh_alen = HH_DATA_ALIGN(hh->hh_len);
  84                 memcpy(skb->data - hh_alen, hh->hh_data, hh_alen);
  85                 read_unlock_bh(&hh->hh_lock);
  86                 skb_push(skb, hh->hh_len);
  87                 return hh->hh_output(skb);
  88         } else if (dst->neighbour)
  89                 return dst->neighbour->output(skb);
  90
  91         IP6_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES);
  92         kfree_skb(skb);
  93         return -EINVAL;
  94
  95 }
  96
  97 /* dev_loopback_xmit for use with netfilter. */
  98 static int ip6_dev_loopback_xmit(struct sk_buff *newskb)
  99 {
 100         newskb->mac.raw = newskb->data;
 101         __skb_pull(newskb, newskb->nh.raw - newskb->data);
 102         newskb->pkt_type = PACKET_LOOPBACK;
 103         newskb->ip_summed = CHECKSUM_UNNECESSARY;
 104         BUG_TRAP(newskb->dst);
 105
 106         netif_rx(newskb);
 107         return 0;
 108 }
 109
 110
 111 static int ip6_output2(struct sk_buff *skb)
 112 {
 113         struct dst_entry *dst = skb->dst;
 114         struct net_device *dev = dst->dev;
 115
 116         skb->protocol = htons(ETH_P_IPV6);
 117         skb->dev = dev;
 118
 119         if (ipv6_addr_is_multicast(&skb->nh.ipv6h->daddr)) {
 120                 struct ipv6_pinfo* np = skb->sk ? inet6_sk(skb->sk) : NULL;
 121
 122                 if (!(dev->flags & IFF_LOOPBACK) && (!np || np->mc_loop) &&
 123                     ipv6_chk_mcast_addr(dev, &skb->nh.ipv6h->daddr,
 124                                 &skb->nh.ipv6h->saddr)) {
 125                         struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC);
 126
 127                         /* Do not check for IFF_ALLMULTI; multicast routing
 128                            is not supported in any case.
 129                          */
 130                         if (newskb)
 131                                 NF_HOOK(PF_INET6, NF_IP6_POST_ROUTING, newskb, NULL,
 132                                         newskb->dev,
 133                                         ip6_dev_loopback_xmit);
 134
 135                         if (skb->nh.ipv6h->hop_limit == 0) {
 136                                 IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
 137                                 kfree_skb(skb);
 138                                 return 0;
 139                         }
 140                 }
 141
 142                 IP6_INC_STATS(IPSTATS_MIB_OUTMCASTPKTS);
 143         }
 144
 145         return NF_HOOK(PF_INET6, NF_IP6_POST_ROUTING, skb,NULL, skb->dev,ip6_output_finish);
 146 }
 147
 148 int ip6_output(struct sk_buff *skb)
 149 {
 150         if ((skb->len > dst_mtu(skb->dst) && !skb_is_gso(skb)) ||
 151                                 dst_allfrag(skb->dst))
 152                 return ip6_fragment(skb, ip6_output2);
 153         else
 154                 return ip6_output2(skb);
 155 }
 156
 157 /*
 158  *      xmit an sk_buff (used by TCP)
 159  */
 160
 161 int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl,
 162              struct ipv6_txoptions *opt, int ipfragok)
 163 {
 164         struct ipv6_pinfo *np = inet6_sk(sk);
 165         struct in6_addr *first_hop = &fl->fl6_dst;
 166         struct dst_entry *dst = skb->dst;
 167         struct ipv6hdr *hdr;
 168         u8  proto = fl->proto;
 169         int seg_len = skb->len;
 170         int hlimit, tclass;
 171         u32 mtu;
 172
 173         if (opt) {
 174                 int head_room;
 175
 176                 /* First: exthdrs may take lots of space (~8K for now)
 177                    MAX_HEADER is not enough.
 178                  */
 179                 head_room = opt->opt_nflen + opt->opt_flen;
 180                 seg_len += head_room;
 181                 head_room += sizeof(struct ipv6hdr) + LL_RESERVED_SPACE(dst->dev);
 182
 183                 if (skb_headroom(skb) < head_room) {
 184                         struct sk_buff *skb2 = skb_realloc_headroom(skb, head_room);
 185                         kfree_skb(skb);
 186                         skb = skb2;
 187                         if (skb == NULL) {
 188                                 IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
 189                                 return -ENOBUFS;
 190                         }
 191                         if (sk)
 192                                 skb_set_owner_w(skb, sk);
 193                 }
 194                 if (opt->opt_flen)
 195                         ipv6_push_frag_opts(skb, opt, &proto);
 196                 if (opt->opt_nflen)
 197                         ipv6_push_nfrag_opts(skb, opt, &proto, &first_hop);
 198         }
 199
 200         hdr = skb->nh.ipv6h = (struct ipv6hdr*)skb_push(skb, sizeof(struct ipv6hdr));
 201
 202         /*
 203          *      Fill in the IPv6 header
 204          */
 205
 206         hlimit = -1;
 207         if (np)
 208                 hlimit = np->hop_limit;
 209         if (hlimit < 0)
 210                 hlimit = dst_metric(dst, RTAX_HOPLIMIT);
 211         if (hlimit < 0)
 212                 hlimit = ipv6_get_hoplimit(dst->dev);
 213
 214         tclass = -1;
 215         if (np)
 216                 tclass = np->tclass;
 217         if (tclass < 0)
 218                 tclass = 0;
 219
 220         *(u32 *)hdr = htonl(0x60000000 | (tclass << 20)) | fl->fl6_flowlabel;
 221
 222         hdr->payload_len = htons(seg_len);
 223         hdr->nexthdr = proto;
 224         hdr->hop_limit = hlimit;
 225
 226         ipv6_addr_copy(&hdr->saddr, &fl->fl6_src);
 227         ipv6_addr_copy(&hdr->daddr, first_hop);
 228
 229         skb->priority = sk->sk_priority;
 230
 231         mtu = dst_mtu(dst);
 232         if ((skb->len <= mtu) || ipfragok || skb_is_gso(skb)) {
 233                 IP6_INC_STATS(IPSTATS_MIB_OUTREQUESTS);
 234                 return NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, dst->dev,
 235                                 dst_output);
 236         }
 237
 238         if (net_ratelimit())
 239                 printk(KERN_DEBUG "IPv6: sending pkt_too_big to self\n");
 240         skb->dev = dst->dev;
 241         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, skb->dev);
 242         IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
 243         kfree_skb(skb);
 244         return -EMSGSIZE;
 245 }
 246
 247 /*
 248  *      To avoid extra problems ND packets are send through this
 249  *      routine. It's code duplication but I really want to avoid
 250  *      extra checks since ipv6_build_header is used by TCP (which
 251  *      is for us performance critical)
 252  */
 253
 254 int ip6_nd_hdr(struct sock *sk, struct sk_buff *skb, struct net_device *dev,
 255                struct in6_addr *saddr, struct in6_addr *daddr,
 256                int proto, int len)
 257 {
 258         struct ipv6_pinfo *np = inet6_sk(sk);
 259         struct ipv6hdr *hdr;
 260         int totlen;
 261
 262         skb->protocol = htons(ETH_P_IPV6);
 263         skb->dev = dev;
 264
 265         totlen = len + sizeof(struct ipv6hdr);
 266
 267         hdr = (struct ipv6hdr *) skb_put(skb, sizeof(struct ipv6hdr));
 268         skb->nh.ipv6h = hdr;
 269
 270         *(u32*)hdr = htonl(0x60000000);
 271
 272         hdr->payload_len = htons(len);
 273         hdr->nexthdr = proto;
 274         hdr->hop_limit = np->hop_limit;
 275
 276         ipv6_addr_copy(&hdr->saddr, saddr);
 277         ipv6_addr_copy(&hdr->daddr, daddr);
 278
 279         return 0;
 280 }
 281
 282 static int ip6_call_ra_chain(struct sk_buff *skb, int sel)
 283 {
 284         struct ip6_ra_chain *ra;
 285         struct sock *last = NULL;
 286
 287         read_lock(&ip6_ra_lock);
 288         for (ra = ip6_ra_chain; ra; ra = ra->next) {
 289                 struct sock *sk = ra->sk;
 290                 if (sk && ra->sel == sel &&
 291                     (!sk->sk_bound_dev_if ||
 292                      sk->sk_bound_dev_if == skb->dev->ifindex)) {
 293                         if (last) {
 294                                 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
 295                                 if (skb2)
 296                                         rawv6_rcv(last, skb2);
 297                         }
 298                         last = sk;
 299                 }
 300         }
 301
 302         if (last) {
 303                 rawv6_rcv(last, skb);
 304                 read_unlock(&ip6_ra_lock);
 305                 return 1;
 306         }
 307         read_unlock(&ip6_ra_lock);
 308         return 0;
 309 }
 310
 311 static inline int ip6_forward_finish(struct sk_buff *skb)
 312 {
 313         return dst_output(skb);
 314 }
 315
 316 int ip6_forward(struct sk_buff *skb)
 317 {
 318         struct dst_entry *dst = skb->dst;
 319         struct ipv6hdr *hdr = skb->nh.ipv6h;
 320         struct inet6_skb_parm *opt = IP6CB(skb);
 321
 322         if (ipv6_devconf.forwarding == 0)
 323                 goto error;
 324
 325         if (!xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) {
 326                 IP6_INC_STATS(IPSTATS_MIB_INDISCARDS);
 327                 goto drop;
 328         }
 329
 330         skb->ip_summed = CHECKSUM_NONE;
 331
 332         /*
 333          *      We DO NOT make any processing on
 334          *      RA packets, pushing them to user level AS IS
 335          *      without ane WARRANTY that application will be able
 336          *      to interpret them. The reason is that we
 337          *      cannot make anything clever here.
 338          *
 339          *      We are not end-node, so that if packet contains
 340          *      AH/ESP, we cannot make anything.
 341          *      Defragmentation also would be mistake, RA packets
 342          *      cannot be fragmented, because there is no warranty
 343          *      that different fragments will go along one path. --ANK
 344          */
 345         if (opt->ra) {
 346                 u8 *ptr = skb->nh.raw + opt->ra;
 347                 if (ip6_call_ra_chain(skb, (ptr[2]<<8) + ptr[3]))
 348                         return 0;
 349         }
 350
 351         /*
 352          *      check and decrement ttl
 353          */
 354         if (hdr->hop_limit <= 1) {
 355                 /* Force OUTPUT device used as source address */
 356                 skb->dev = dst->dev;
 357                 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
 358                             0, skb->dev);
 359                 IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
 360
 361                 kfree_skb(skb);
 362                 return -ETIMEDOUT;
 363         }
 364
 365         if (!xfrm6_route_forward(skb)) {
 366                 IP6_INC_STATS(IPSTATS_MIB_INDISCARDS);
 367                 goto drop;
 368         }
 369         dst = skb->dst;
 370
 371         /* IPv6 specs say nothing about it, but it is clear that we cannot
 372            send redirects to source routed frames.
 373          */
 374         if (skb->dev == dst->dev && dst->neighbour && opt->srcrt == 0) {
 375                 struct in6_addr *target = NULL;
 376                 struct rt6_info *rt;
 377                 struct neighbour *n = dst->neighbour;
 378
 379                 /*
 380                  *      incoming and outgoing devices are the same
 381                  *      send a redirect.
 382                  */
 383
 384                 rt = (struct rt6_info *) dst;
 385                 if ((rt->rt6i_flags & RTF_GATEWAY))
 386                         target = (struct in6_addr*)&n->primary_key;
 387                 else
 388                         target = &hdr->daddr;
 389
 390                 /* Limit redirects both by destination (here)
 391                    and by source (inside ndisc_send_redirect)
 392                  */
 393                 if (xrlim_allow(dst, 1*HZ))
 394                         ndisc_send_redirect(skb, n, target);
 395         } else if (ipv6_addr_type(&hdr->saddr)&(IPV6_ADDR_MULTICAST|IPV6_ADDR_LOOPBACK
 396                                                 |IPV6_ADDR_LINKLOCAL)) {
 397                 /* This check is security critical. */
 398                 goto error;
 399         }
 400
 401         if (skb->len > dst_mtu(dst)) {
 402                 /* Again, force OUTPUT device used as source address */
 403                 skb->dev = dst->dev;
 404                 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, dst_mtu(dst), skb->dev);
 405                 IP6_INC_STATS_BH(IPSTATS_MIB_INTOOBIGERRORS);
 406                 IP6_INC_STATS_BH(IPSTATS_MIB_FRAGFAILS);
 407                 kfree_skb(skb);
 408                 return -EMSGSIZE;
 409         }
 410
 411         if (skb_cow(skb, dst->dev->hard_header_len)) {
 412                 IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
 413                 goto drop;
 414         }
 415
 416         hdr = skb->nh.ipv6h;
 417
 418         /* Mangling hops number delayed to point after skb COW */
 419
 420         hdr->hop_limit--;
 421
 422         IP6_INC_STATS_BH(IPSTATS_MIB_OUTFORWDATAGRAMS);
 423         return NF_HOOK(PF_INET6,NF_IP6_FORWARD, skb, skb->dev, dst->dev, ip6_forward_finish);
 424
 425 error:
 426         IP6_INC_STATS_BH(IPSTATS_MIB_INADDRERRORS);
 427 drop:
 428         kfree_skb(skb);
 429         return -EINVAL;
 430 }
 431
 432 static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from)
 433 {
 434         to->pkt_type = from->pkt_type;
 435         to->priority = from->priority;
 436         to->protocol = from->protocol;
 437         dst_release(to->dst);
 438         to->dst = dst_clone(from->dst);
 439         to->dev = from->dev;
 440
 441 #ifdef CONFIG_NET_SCHED
 442         to->tc_index = from->tc_index;
 443 #endif
 444 #ifdef CONFIG_NETFILTER
 445         to->nfmark = from->nfmark;
 446         /* Connection association is same as pre-frag packet */
 447         nf_conntrack_put(to->nfct);
 448         to->nfct = from->nfct;
 449         nf_conntrack_get(to->nfct);
 450         to->nfctinfo = from->nfctinfo;
 451 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
 452         nf_conntrack_put_reasm(to->nfct_reasm);
 453         to->nfct_reasm = from->nfct_reasm;
 454         nf_conntrack_get_reasm(to->nfct_reasm);
 455 #endif
 456 #ifdef CONFIG_BRIDGE_NETFILTER
 457         nf_bridge_put(to->nf_bridge);
 458         to->nf_bridge = from->nf_bridge;
 459         nf_bridge_get(to->nf_bridge);
 460 #endif
 461 #endif
 462         skb_copy_secmark(to, from);
 463 }
 464
 465 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr)
 466 {
 467         u16 offset = sizeof(struct ipv6hdr);
 468         struct ipv6_opt_hdr *exthdr = (struct ipv6_opt_hdr*)(skb->nh.ipv6h + 1);
 469         unsigned int packet_len = skb->tail - skb->nh.raw;
 470         int found_rhdr = 0;
 471         *nexthdr = &skb->nh.ipv6h->nexthdr;
 472
 473         while (offset + 1 <= packet_len) {
 474
 475                 switch (**nexthdr) {
 476
 477                 case NEXTHDR_HOP:
 478                 case NEXTHDR_ROUTING:
 479                 case NEXTHDR_DEST:
 480                         if (**nexthdr == NEXTHDR_ROUTING) found_rhdr = 1;
 481                         if (**nexthdr == NEXTHDR_DEST && found_rhdr) return offset;
 482                         offset += ipv6_optlen(exthdr);
 483                         *nexthdr = &exthdr->nexthdr;
 484                         exthdr = (struct ipv6_opt_hdr*)(skb->nh.raw + offset);
 485                         break;
 486                 default :
 487                         return offset;
 488                 }
 489         }
 490
 491         return offset;
 492 }
 493 EXPORT_SYMBOL_GPL(ip6_find_1stfragopt);
 494
 495 static int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *))
 496 {
 497         struct net_device *dev;
 498         struct sk_buff *frag;
 499         struct rt6_info *rt = (struct rt6_info*)skb->dst;
 500         struct ipv6_pinfo *np = skb->sk ? inet6_sk(skb->sk) : NULL;
 501         struct ipv6hdr *tmp_hdr;
 502         struct frag_hdr *fh;
 503         unsigned int mtu, hlen, left, len;
 504         u32 frag_id = 0;
 505         int ptr, offset = 0, err=0;
 506         u8 *prevhdr, nexthdr = 0;
 507
 508         dev = rt->u.dst.dev;
 509         hlen = ip6_find_1stfragopt(skb, &prevhdr);
 510         nexthdr = *prevhdr;
 511
 512         mtu = dst_mtu(&rt->u.dst);
 513         if (np && np->frag_size < mtu) {
 514                 if (np->frag_size)
 515                         mtu = np->frag_size;
 516         }
 517         mtu -= hlen + sizeof(struct frag_hdr);
 518
 519         if (skb_shinfo(skb)->frag_list) {
 520                 int first_len = skb_pagelen(skb);
 521
 522                 if (first_len - hlen > mtu ||
 523                     ((first_len - hlen) & 7) ||
 524                     skb_cloned(skb))
 525                         goto slow_path;
 526
 527                 for (frag = skb_shinfo(skb)->frag_list; frag; frag = frag->next) {
 528                         /* Correct geometry. */
 529                         if (frag->len > mtu ||
 530                             ((frag->len & 7) && frag->next) ||
 531                             skb_headroom(frag) < hlen)
 532                             goto slow_path;
 533
 534                         /* Partially cloned skb? */
 535                         if (skb_shared(frag))
 536                                 goto slow_path;
 537
 538                         BUG_ON(frag->sk);
 539                         if (skb->sk) {
 540                                 sock_hold(skb->sk);
 541                                 frag->sk = skb->sk;
 542                                 frag->destructor = sock_wfree;
 543                                 skb->truesize -= frag->truesize;
 544                         }
 545                 }
 546
 547                 err = 0;
 548                 offset = 0;
 549                 frag = skb_shinfo(skb)->frag_list;
 550                 skb_shinfo(skb)->frag_list = NULL;
 551                 /* BUILD HEADER */
 552
 553                 tmp_hdr = kmalloc(hlen, GFP_ATOMIC);
 554                 if (!tmp_hdr) {
 555                         IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
 556                         return -ENOMEM;
 557                 }
 558
 559                 *prevhdr = NEXTHDR_FRAGMENT;
 560                 memcpy(tmp_hdr, skb->nh.raw, hlen);
 561                 __skb_pull(skb, hlen);
 562                 fh = (struct frag_hdr*)__skb_push(skb, sizeof(struct frag_hdr));
 563                 skb->nh.raw = __skb_push(skb, hlen);
 564                 memcpy(skb->nh.raw, tmp_hdr, hlen);
 565
 566                 ipv6_select_ident(skb, fh);
 567                 fh->nexthdr = nexthdr;
 568                 fh->reserved = 0;
 569                 fh->frag_off = htons(IP6_MF);
 570                 frag_id = fh->identification;
 571
 572                 first_len = skb_pagelen(skb);
 573                 skb->data_len = first_len - skb_headlen(skb);
 574                 skb->len = first_len;
 575                 skb->nh.ipv6h->payload_len = htons(first_len - sizeof(struct ipv6hdr));
 576
 577
 578                 for (;;) {
 579                         /* Prepare header of the next frame,
 580                          * before previous one went down. */
 581                         if (frag) {
 582                                 frag->ip_summed = CHECKSUM_NONE;
 583                                 frag->h.raw = frag->data;
 584                                 fh = (struct frag_hdr*)__skb_push(frag, sizeof(struct frag_hdr));
 585                                 frag->nh.raw = __skb_push(frag, hlen);
 586                                 memcpy(frag->nh.raw, tmp_hdr, hlen);
 587                                 offset += skb->len - hlen - sizeof(struct frag_hdr);
 588                                 fh->nexthdr = nexthdr;
 589                                 fh->reserved = 0;
 590                                 fh->frag_off = htons(offset);
 591                                 if (frag->next != NULL)
 592                                         fh->frag_off |= htons(IP6_MF);
 593                                 fh->identification = frag_id;
 594                                 frag->nh.ipv6h->payload_len = htons(frag->len - sizeof(struct ipv6hdr));
 595                                 ip6_copy_metadata(frag, skb);
 596                         }
 597
 598                         err = output(skb);
 599                         if(!err)
 600                                 IP6_INC_STATS(IPSTATS_MIB_FRAGCREATES);
 601
 602                         if (err || !frag)
 603                                 break;
 604
 605                         skb = frag;
 606                         frag = skb->next;
 607                         skb->next = NULL;
 608                 }
 609
 610                 kfree(tmp_hdr);
 611
 612                 if (err == 0) {
 613                         IP6_INC_STATS(IPSTATS_MIB_FRAGOKS);
 614                         return 0;
 615                 }
 616
 617                 while (frag) {
 618                         skb = frag->next;
 619                         kfree_skb(frag);
 620                         frag = skb;
 621                 }
 622
 623                 IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
 624                 return err;
 625         }
 626
 627 slow_path:
 628         left = skb->len - hlen;         /* Space per frame */
 629         ptr = hlen;                     /* Where to start from */
 630
 631         /*
 632          *      Fragment the datagram.
 633          */
 634
 635         *prevhdr = NEXTHDR_FRAGMENT;
 636
 637         /*
 638          *      Keep copying data until we run out.
 639          */
 640         while(left > 0) {
 641                 len = left;
 642                 /* IF: it doesn't fit, use 'mtu' - the data space left */
 643                 if (len > mtu)
 644                         len = mtu;
 645                 /* IF: we are not sending upto and including the packet end
 646                    then align the next start on an eight byte boundary */
 647                 if (len < left) {
 648                         len &= ~7;
 649                 }
 650                 /*
 651                  *      Allocate buffer.
 652                  */
 653
 654                 if ((frag = alloc_skb(len+hlen+sizeof(struct frag_hdr)+LL_RESERVED_SPACE(rt->u.dst.dev), GFP_ATOMIC)) == NULL) {
 655                         NETDEBUG(KERN_INFO "IPv6: frag: no memory for new fragment!\n");
 656                         IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
 657                         err = -ENOMEM;
 658                         goto fail;
 659                 }
 660
 661                 /*
 662                  *      Set up data on packet
 663                  */
 664
 665                 ip6_copy_metadata(frag, skb);
 666                 skb_reserve(frag, LL_RESERVED_SPACE(rt->u.dst.dev));
 667                 skb_put(frag, len + hlen + sizeof(struct frag_hdr));
 668                 frag->nh.raw = frag->data;
 669                 fh = (struct frag_hdr*)(frag->data + hlen);
 670                 frag->h.raw = frag->data + hlen + sizeof(struct frag_hdr);
 671
 672                 /*
 673                  *      Charge the memory for the fragment to any owner
 674                  *      it might possess
 675                  */
 676                 if (skb->sk)
 677                         skb_set_owner_w(frag, skb->sk);
 678
 679                 /*
 680                  *      Copy the packet header into the new buffer.
 681                  */
 682                 memcpy(frag->nh.raw, skb->data, hlen);
 683
 684                 /*
 685                  *      Build fragment header.
 686                  */
 687                 fh->nexthdr = nexthdr;
 688                 fh->reserved = 0;
 689                 if (!frag_id) {
 690                         ipv6_select_ident(skb, fh);
 691                         frag_id = fh->identification;
 692                 } else
 693                         fh->identification = frag_id;
 694
 695                 /*
 696                  *      Copy a block of the IP datagram.
 697                  */
 698                 if (skb_copy_bits(skb, ptr, frag->h.raw, len))
 699                         BUG();
 700                 left -= len;
 701
 702                 fh->frag_off = htons(offset);
 703                 if (left > 0)
 704                         fh->frag_off |= htons(IP6_MF);
 705                 frag->nh.ipv6h->payload_len = htons(frag->len - sizeof(struct ipv6hdr));
 706
 707                 ptr += len;
 708                 offset += len;
 709
 710                 /*
 711                  *      Put this fragment into the sending queue.
 712                  */
 713                 err = output(frag);
 714                 if (err)
 715                         goto fail;
 716
 717                 IP6_INC_STATS(IPSTATS_MIB_FRAGCREATES);
 718         }
 719         kfree_skb(skb);
 720         IP6_INC_STATS(IPSTATS_MIB_FRAGOKS);
 721         return err;
 722
 723 fail:
 724         kfree_skb(skb);
 725         IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
 726         return err;
 727 }
 728
 729 static inline int ip6_rt_check(struct rt6key *rt_key,
 730                                struct in6_addr *fl_addr,
 731                                struct in6_addr *addr_cache)
 732 {
 733         return ((rt_key->plen != 128 || !ipv6_addr_equal(fl_addr, &rt_key->addr)) &&
 734                 (addr_cache == NULL || !ipv6_addr_equal(fl_addr, addr_cache)));
 735 }
 736
 737 static struct dst_entry *ip6_sk_dst_check(struct sock *sk,
 738                                           struct dst_entry *dst,
 739                                           struct flowi *fl)
 740 {
 741         struct ipv6_pinfo *np = inet6_sk(sk);
 742         struct rt6_info *rt = (struct rt6_info *)dst;
 743
 744         if (!dst)
 745                 goto out;
 746
 747         /* Yes, checking route validity in not connected
 748          * case is not very simple. Take into account,
 749          * that we do not support routing by source, TOS,
 750          * and MSG_DONTROUTE            --ANK (980726)
 751          *
 752          * 1. ip6_rt_check(): If route was host route,
 753          *    check that cached destination is current.
 754          *    If it is network route, we still may
 755          *    check its validity using saved pointer
 756          *    to the last used address: daddr_cache.
 757          *    We do not want to save whole address now,
 758          *    (because main consumer of this service
 759          *    is tcp, which has not this problem),
 760          *    so that the last trick works only on connected
 761          *    sockets.
 762          * 2. oif also should be the same.
 763          */
 764         if (ip6_rt_check(&rt->rt6i_dst, &fl->fl6_dst, np->daddr_cache) ||
 765             (fl->oif && fl->oif != dst->dev->ifindex)) {
 766                 dst_release(dst);
 767                 dst = NULL;
 768         }
 769
 770 out:
 771         return dst;
 772 }
 773
 774 static int ip6_dst_lookup_tail(struct sock *sk,
 775                                struct dst_entry **dst, struct flowi *fl)
 776 {
 777         int err;
 778
 779         if (*dst == NULL)
 780                 *dst = ip6_route_output(sk, fl);
 781
 782         if ((err = (*dst)->error))
 783                 goto out_err_release;
 784
 785         if (ipv6_addr_any(&fl->fl6_src)) {
 786                 err = ipv6_get_saddr(*dst, &fl->fl6_dst, &fl->fl6_src);
 787                 if (err)
 788                         goto out_err_release;
 789         }
 790
 791         return 0;
 792
 793 out_err_release:
 794         dst_release(*dst);
 795         *dst = NULL;
 796         return err;
 797 }
 798
 799 /**
 800  *      ip6_dst_lookup - perform route lookup on flow
 801  *      @sk: socket which provides route info
 802  *      @dst: pointer to dst_entry * for result
 803  *      @fl: flow to lookup
 804  *
 805  *      This function performs a route lookup on the given flow.
 806  *
 807  *      It returns zero on success, or a standard errno code on error.
 808  */
 809 int ip6_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi *fl)
 810 {
 811         *dst = NULL;
 812         return ip6_dst_lookup_tail(sk, dst, fl);
 813 }
 814 EXPORT_SYMBOL_GPL(ip6_dst_lookup);
 815
 816 /**
 817  *      ip6_sk_dst_lookup - perform socket cached route lookup on flow
 818  *      @sk: socket which provides the dst cache and route info
 819  *      @dst: pointer to dst_entry * for result
 820  *      @fl: flow to lookup
 821  *
 822  *      This function performs a route lookup on the given flow with the
 823  *      possibility of using the cached route in the socket if it is valid.
 824  *      It will take the socket dst lock when operating on the dst cache.
 825  *      As a result, this function can only be used in process context.
 826  *
 827  *      It returns zero on success, or a standard errno code on error.
 828  */
 829 int ip6_sk_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi *fl)
 830 {
 831         *dst = NULL;
 832         if (sk) {
 833                 *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie);
 834                 *dst = ip6_sk_dst_check(sk, *dst, fl);
 835         }
 836
 837         return ip6_dst_lookup_tail(sk, dst, fl);
 838 }
 839 EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup);
 840
 841 static inline int ip6_ufo_append_data(struct sock *sk,
 842                         int getfrag(void *from, char *to, int offset, int len,
 843                         int odd, struct sk_buff *skb),
 844                         void *from, int length, int hh_len, int fragheaderlen,
 845                         int transhdrlen, int mtu,unsigned int flags)
 846
 847 {
 848         struct sk_buff *skb;
 849         int err;
 850
 851         /* There is support for UDP large send offload by network
 852          * device, so create one single skb packet containing complete
 853          * udp datagram
 854          */
 855         if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) {
 856                 skb = sock_alloc_send_skb(sk,
 857                         hh_len + fragheaderlen + transhdrlen + 20,
 858                         (flags & MSG_DONTWAIT), &err);
 859                 if (skb == NULL)
 860                         return -ENOMEM;
 861
 862                 /* reserve space for Hardware header */
 863                 skb_reserve(skb, hh_len);
 864
 865                 /* create space for UDP/IP header */
 866                 skb_put(skb,fragheaderlen + transhdrlen);
 867
 868                 /* initialize network header pointer */
 869                 skb->nh.raw = skb->data;
 870
 871                 /* initialize protocol header pointer */
 872                 skb->h.raw = skb->data + fragheaderlen;
 873
 874                 skb->ip_summed = CHECKSUM_PARTIAL;
 875                 skb->csum = 0;
 876                 sk->sk_sndmsg_off = 0;
 877         }
 878
 879         err = skb_append_datato_frags(sk,skb, getfrag, from,
 880                                       (length - transhdrlen));
 881         if (!err) {
 882                 struct frag_hdr fhdr;
 883
 884                 /* specify the length of each IP datagram fragment*/
 885                 skb_shinfo(skb)->gso_size = mtu - fragheaderlen -
 886                                             sizeof(struct frag_hdr);
 887                 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
 888                 ipv6_select_ident(skb, &fhdr);
 889                 skb_shinfo(skb)->ip6_frag_id = fhdr.identification;
 890                 __skb_queue_tail(&sk->sk_write_queue, skb);
 891
 892                 return 0;
 893         }
 894         /* There is not enough support do UPD LSO,
 895          * so follow normal path
 896          */
 897         kfree_skb(skb);
 898
 899         return err;
 900 }
 901
 902 int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
 903         int offset, int len, int odd, struct sk_buff *skb),
 904         void *from, int length, int transhdrlen,
 905         int hlimit, int tclass, struct ipv6_txoptions *opt, struct flowi *fl,
 906         struct rt6_info *rt, unsigned int flags)
 907 {
 908         struct inet_sock *inet = inet_sk(sk);
 909         struct ipv6_pinfo *np = inet6_sk(sk);
 910         struct sk_buff *skb;
 911         unsigned int maxfraglen, fragheaderlen;
 912         int exthdrlen;
 913         int hh_len;
 914         int mtu;
 915         int copy;
 916         int err;
 917         int offset = 0;
 918         int csummode = CHECKSUM_NONE;
 919
 920         if (flags&MSG_PROBE)
 921                 return 0;
 922         if (skb_queue_empty(&sk->sk_write_queue)) {
 923                 /*
 924                  * setup for corking
 925                  */
 926                 if (opt) {
 927                         if (np->cork.opt == NULL) {
 928                                 np->cork.opt = kmalloc(opt->tot_len,
 929                                                        sk->sk_allocation);
 930                                 if (unlikely(np->cork.opt == NULL))
 931                                         return -ENOBUFS;
 932                         } else if (np->cork.opt->tot_len < opt->tot_len) {
 933                                 printk(KERN_DEBUG "ip6_append_data: invalid option length\n");
 934                                 return -EINVAL;
 935                         }
 936                         memcpy(np->cork.opt, opt, opt->tot_len);
 937                         inet->cork.flags |= IPCORK_OPT;
 938                         /* need source address above miyazawa*/
 939                 }
 940                 dst_hold(&rt->u.dst);
 941                 np->cork.rt = rt;
 942                 inet->cork.fl = *fl;
 943                 np->cork.hop_limit = hlimit;
 944                 np->cork.tclass = tclass;
 945                 mtu = dst_mtu(rt->u.dst.path);
 946                 if (np->frag_size < mtu) {
 947                         if (np->frag_size)
 948                                 mtu = np->frag_size;
 949                 }
 950                 inet->cork.fragsize = mtu;
 951                 if (dst_allfrag(rt->u.dst.path))
 952                         inet->cork.flags |= IPCORK_ALLFRAG;
 953                 inet->cork.length = 0;
 954                 sk->sk_sndmsg_page = NULL;
 955                 sk->sk_sndmsg_off = 0;
 956                 exthdrlen = rt->u.dst.header_len + (opt ? opt->opt_flen : 0);
 957                 length += exthdrlen;
 958                 transhdrlen += exthdrlen;
 959         } else {
 960                 rt = np->cork.rt;
 961                 fl = &inet->cork.fl;
 962                 if (inet->cork.flags & IPCORK_OPT)
 963                         opt = np->cork.opt;
 964                 transhdrlen = 0;
 965                 exthdrlen = 0;
 966                 mtu = inet->cork.fragsize;
 967         }
 968
 969         hh_len = LL_RESERVED_SPACE(rt->u.dst.dev);
 970
 971         fragheaderlen = sizeof(struct ipv6hdr) + (opt ? opt->opt_nflen : 0);
 972         maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - sizeof(struct frag_hdr);
 973
 974         if (mtu <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN) {
 975                 if (inet->cork.length + length > sizeof(struct ipv6hdr) + IPV6_MAXPLEN - fragheaderlen) {
 976                         ipv6_local_error(sk, EMSGSIZE, fl, mtu-exthdrlen);
 977                         return -EMSGSIZE;
 978                 }
 979         }
 980
 981         /*
 982          * Let's try using as much space as possible.
 983          * Use MTU if total length of the message fits into the MTU.
 984          * Otherwise, we need to reserve fragment header and
 985          * fragment alignment (= 8-15 octects, in total).
 986          *
 987          * Note that we may need to "move" the data from the tail of
 988          * of the buffer to the new fragment when we split
 989          * the message.
 990          *
 991          * FIXME: It may be fragmented into multiple chunks
 992          *        at once if non-fragmentable extension headers
 993          *        are too large.
 994          * --yoshfuji
 995          */
 996
 997         inet->cork.length += length;
 998         if (((length > mtu) && (sk->sk_protocol == IPPROTO_UDP)) &&
 999             (rt->u.dst.dev->features & NETIF_F_UFO)) {
1000
1001                 err = ip6_ufo_append_data(sk, getfrag, from, length, hh_len,
1002                                           fragheaderlen, transhdrlen, mtu,
1003                                           flags);
1004                 if (err)
1005                         goto error;
1006                 return 0;
1007         }
1008
1009         if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL)
1010                 goto alloc_new_skb;
1011
1012         while (length > 0) {
1013                 /* Check if the remaining data fits into current packet. */
1014                 copy = (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len;
1015                 if (copy < length)
1016                         copy = maxfraglen - skb->len;
1017
1018                 if (copy <= 0) {
1019                         char *data;
1020                         unsigned int datalen;
1021                         unsigned int fraglen;
1022                         unsigned int fraggap;
1023                         unsigned int alloclen;
1024                         struct sk_buff *skb_prev;
1025 alloc_new_skb:
1026                         skb_prev = skb;
1027
1028                         /* There's no room in the current skb */
1029                         if (skb_prev)
1030                                 fraggap = skb_prev->len - maxfraglen;
1031                         else
1032                                 fraggap = 0;
1033
1034                         /*
1035                          * If remaining data exceeds the mtu,
1036                          * we know we need more fragment(s).
1037                          */
1038                         datalen = length + fraggap;
1039                         if (datalen > (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen)
1040                                 datalen = maxfraglen - fragheaderlen;
1041
1042                         fraglen = datalen + fragheaderlen;
1043                         if ((flags & MSG_MORE) &&
1044                             !(rt->u.dst.dev->features&NETIF_F_SG))
1045                                 alloclen = mtu;
1046                         else
1047                                 alloclen = datalen + fragheaderlen;
1048
1049                         /*
1050                          * The last fragment gets additional space at tail.
1051                          * Note: we overallocate on fragments with MSG_MODE
1052                          * because we have no idea if we're the last one.
1053                          */
1054                         if (datalen == length + fraggap)
1055                                 alloclen += rt->u.dst.trailer_len;
1056
1057                         /*
1058                          * We just reserve space for fragment header.
1059                          * Note: this may be overallocation if the message
1060                          * (without MSG_MORE) fits into the MTU.
1061                          */
1062                         alloclen += sizeof(struct frag_hdr);
1063
1064                         if (transhdrlen) {
1065                                 skb = sock_alloc_send_skb(sk,
1066                                                 alloclen + hh_len,
1067                                                 (flags & MSG_DONTWAIT), &err);
1068                         } else {
1069                                 skb = NULL;
1070                                 if (atomic_read(&sk->sk_wmem_alloc) <=
1071                                     2 * sk->sk_sndbuf)
1072                                         skb = sock_wmalloc(sk,
1073                                                            alloclen + hh_len, 1,
1074                                                            sk->sk_allocation);
1075                                 if (unlikely(skb == NULL))
1076                                         err = -ENOBUFS;
1077                         }
1078                         if (skb == NULL)
1079                                 goto error;
1080                         /*
1081                          *      Fill in the control structures
1082                          */
1083                         skb->ip_summed = csummode;
1084                         skb->csum = 0;
1085                         /* reserve for fragmentation */
1086                         skb_reserve(skb, hh_len+sizeof(struct frag_hdr));
1087
1088                         /*
1089                          *      Find where to start putting bytes
1090                          */
1091                         data = skb_put(skb, fraglen);
1092                         skb->nh.raw = data + exthdrlen;
1093                         data += fragheaderlen;
1094                         skb->h.raw = data + exthdrlen;
1095
1096                         if (fraggap) {
1097                                 skb->csum = skb_copy_and_csum_bits(
1098                                         skb_prev, maxfraglen,
1099                                         data + transhdrlen, fraggap, 0);
1100                                 skb_prev->csum = csum_sub(skb_prev->csum,
1101                                                           skb->csum);
1102                                 data += fraggap;
1103                                 pskb_trim_unique(skb_prev, maxfraglen);
1104                         }
1105                         copy = datalen - transhdrlen - fraggap;
1106                         if (copy < 0) {
1107                                 err = -EINVAL;
1108                                 kfree_skb(skb);
1109                                 goto error;
1110                         } else if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) {
1111                                 err = -EFAULT;
1112                                 kfree_skb(skb);
1113                                 goto error;
1114                         }
1115
1116                         offset += copy;
1117                         length -= datalen - fraggap;
1118                         transhdrlen = 0;
1119                         exthdrlen = 0;
1120                         csummode = CHECKSUM_NONE;
1121
1122                         /*
1123                          * Put the packet on the pending queue
1124                          */
1125                         __skb_queue_tail(&sk->sk_write_queue, skb);
1126                         continue;
1127                 }
1128
1129                 if (copy > length)
1130                         copy = length;
1131
1132                 if (!(rt->u.dst.dev->features&NETIF_F_SG)) {
1133                         unsigned int off;
1134
1135                         off = skb->len;
1136                         if (getfrag(from, skb_put(skb, copy),
1137                                                 offset, copy, off, skb) < 0) {
1138                                 __skb_trim(skb, off);
1139                                 err = -EFAULT;
1140                                 goto error;
1141                         }
1142                 } else {
1143                         int i = skb_shinfo(skb)->nr_frags;
1144                         skb_frag_t *frag = &skb_shinfo(skb)->frags[i-1];
1145                         struct page *page = sk->sk_sndmsg_page;
1146                         int off = sk->sk_sndmsg_off;
1147                         unsigned int left;
1148
1149                         if (page && (left = PAGE_SIZE - off) > 0) {
1150                                 if (copy >= left)
1151                                         copy = left;
1152                                 if (page != frag->page) {
1153                                         if (i == MAX_SKB_FRAGS) {
1154                                                 err = -EMSGSIZE;
1155                                                 goto error;
1156                                         }
1157                                         get_page(page);
1158                                         skb_fill_page_desc(skb, i, page, sk->sk_sndmsg_off, 0);
1159                                         frag = &skb_shinfo(skb)->frags[i];
1160                                 }
1161                         } else if(i < MAX_SKB_FRAGS) {
1162                                 if (copy > PAGE_SIZE)
1163                                         copy = PAGE_SIZE;
1164                                 page = alloc_pages(sk->sk_allocation, 0);
1165                                 if (page == NULL) {
1166                                         err = -ENOMEM;
1167                                         goto error;
1168                                 }
1169                                 sk->sk_sndmsg_page = page;
1170                                 sk->sk_sndmsg_off = 0;
1171
1172                                 skb_fill_page_desc(skb, i, page, 0, 0);
1173                                 frag = &skb_shinfo(skb)->frags[i];
1174                                 skb->truesize += PAGE_SIZE;
1175                                 atomic_add(PAGE_SIZE, &sk->sk_wmem_alloc);
1176                         } else {
1177                                 err = -EMSGSIZE;
1178                                 goto error;
1179                         }
1180                         if (getfrag(from, page_address(frag->page)+frag->page_offset+frag->size, offset, copy, skb->len, skb) < 0) {
1181                                 err = -EFAULT;
1182                                 goto error;
1183                         }
1184                         sk->sk_sndmsg_off += copy;
1185                         frag->size += copy;
1186                         skb->len += copy;
1187                         skb->data_len += copy;
1188                 }
1189                 offset += copy;
1190                 length -= copy;
1191         }
1192         return 0;
1193 error:
1194         inet->cork.length -= length;
1195         IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
1196         return err;
1197 }
1198
1199 int ip6_push_pending_frames(struct sock *sk)
1200 {
1201         struct sk_buff *skb, *tmp_skb;
1202         struct sk_buff **tail_skb;
1203         struct in6_addr final_dst_buf, *final_dst = &final_dst_buf;
1204         struct inet_sock *inet = inet_sk(sk);
1205         struct ipv6_pinfo *np = inet6_sk(sk);
1206         struct ipv6hdr *hdr;
1207         struct ipv6_txoptions *opt = np->cork.opt;
1208         struct rt6_info *rt = np->cork.rt;
1209         struct flowi *fl = &inet->cork.fl;
1210         unsigned char proto = fl->proto;
1211         int err = 0;
1212
1213         if ((skb = __skb_dequeue(&sk->sk_write_queue)) == NULL)
1214                 goto out;
1215         tail_skb = &(skb_shinfo(skb)->frag_list);
1216
1217         /* move skb->data to ip header from ext header */
1218         if (skb->data < skb->nh.raw)
1219                 __skb_pull(skb, skb->nh.raw - skb->data);
1220         while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) {
1221                 __skb_pull(tmp_skb, skb->h.raw - skb->nh.raw);
1222                 *tail_skb = tmp_skb;
1223                 tail_skb = &(tmp_skb->next);
1224                 skb->len += tmp_skb->len;
1225                 skb->data_len += tmp_skb->len;
1226                 skb->truesize += tmp_skb->truesize;
1227                 __sock_put(tmp_skb->sk);
1228                 tmp_skb->destructor = NULL;
1229                 tmp_skb->sk = NULL;
1230         }
1231
1232         ipv6_addr_copy(final_dst, &fl->fl6_dst);
1233         __skb_pull(skb, skb->h.raw - skb->nh.raw);
1234         if (opt && opt->opt_flen)
1235                 ipv6_push_frag_opts(skb, opt, &proto);
1236         if (opt && opt->opt_nflen)
1237                 ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst);
1238
1239         skb->nh.ipv6h = hdr = (struct ipv6hdr*) skb_push(skb, sizeof(struct ipv6hdr));
1240
1241         *(u32*)hdr = fl->fl6_flowlabel |
1242                      htonl(0x60000000 | ((int)np->cork.tclass << 20));
1243
1244         if (skb->len <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN)
1245                 hdr->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
1246         else
1247                 hdr->payload_len = 0;
1248         hdr->hop_limit = np->cork.hop_limit;
1249         hdr->nexthdr = proto;
1250         ipv6_addr_copy(&hdr->saddr, &fl->fl6_src);
1251         ipv6_addr_copy(&hdr->daddr, final_dst);
1252
1253         skb->priority = sk->sk_priority;
1254
1255         skb->dst = dst_clone(&rt->u.dst);
1256         IP6_INC_STATS(IPSTATS_MIB_OUTREQUESTS);
1257         err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, skb->dst->dev, dst_output);
1258         if (err) {
1259                 if (err > 0)
1260                         err = np->recverr ? net_xmit_errno(err) : 0;
1261                 if (err)
1262                         goto error;
1263         }
1264
1265 out:
1266         inet->cork.flags &= ~IPCORK_OPT;
1267         kfree(np->cork.opt);
1268         np->cork.opt = NULL;
1269         if (np->cork.rt) {
1270                 dst_release(&np->cork.rt->u.dst);
1271                 np->cork.rt = NULL;
1272                 inet->cork.flags &= ~IPCORK_ALLFRAG;
1273         }
1274         memset(&inet->cork.fl, 0, sizeof(inet->cork.fl));
1275         return err;
1276 error:
1277         goto out;
1278 }
1279
1280 void ip6_flush_pending_frames(struct sock *sk)
1281 {
1282         struct inet_sock *inet = inet_sk(sk);
1283         struct ipv6_pinfo *np = inet6_sk(sk);
1284         struct sk_buff *skb;
1285
1286         while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) {
1287                 IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
1288                 kfree_skb(skb);
1289         }
1290
1291         inet->cork.flags &= ~IPCORK_OPT;
1292
1293         kfree(np->cork.opt);
1294         np->cork.opt = NULL;
1295         if (np->cork.rt) {
1296                 dst_release(&np->cork.rt->u.dst);
1297                 np->cork.rt = NULL;
1298                 inet->cork.flags &= ~IPCORK_ALLFRAG;
1299         }
1300         memset(&inet->cork.fl, 0, sizeof(inet->cork.fl));
1301 }