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