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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         struct dst_entry *dst = skb->dst;
  76
  77         if (dst->hh)
  78                 return neigh_hh_output(dst->hh, skb);
  79         else if (dst->neighbour)
  80                 return dst->neighbour->output(skb);
  81
  82         IP6_INC_STATS_BH(ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
  83         kfree_skb(skb);
  84         return -EINVAL;
  85
  86 }
  87
  88 /* dev_loopback_xmit for use with netfilter. */
  89 static int ip6_dev_loopback_xmit(struct sk_buff *newskb)
  90 {
  91         skb_reset_mac_header(newskb);
  92         __skb_pull(newskb, newskb->nh.raw - newskb->data);
  93         newskb->pkt_type = PACKET_LOOPBACK;
  94         newskb->ip_summed = CHECKSUM_UNNECESSARY;
  95         BUG_TRAP(newskb->dst);
  96
  97         netif_rx(newskb);
  98         return 0;
  99 }
 100
 101
 102 static int ip6_output2(struct sk_buff *skb)
 103 {
 104         struct dst_entry *dst = skb->dst;
 105         struct net_device *dev = dst->dev;
 106
 107         skb->protocol = htons(ETH_P_IPV6);
 108         skb->dev = dev;
 109
 110         if (ipv6_addr_is_multicast(&skb->nh.ipv6h->daddr)) {
 111                 struct ipv6_pinfo* np = skb->sk ? inet6_sk(skb->sk) : NULL;
 112                 struct inet6_dev *idev = ip6_dst_idev(skb->dst);
 113
 114                 if (!(dev->flags & IFF_LOOPBACK) && (!np || np->mc_loop) &&
 115                     ipv6_chk_mcast_addr(dev, &skb->nh.ipv6h->daddr,
 116                                 &skb->nh.ipv6h->saddr)) {
 117                         struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC);
 118
 119                         /* Do not check for IFF_ALLMULTI; multicast routing
 120                            is not supported in any case.
 121                          */
 122                         if (newskb)
 123                                 NF_HOOK(PF_INET6, NF_IP6_POST_ROUTING, newskb, NULL,
 124                                         newskb->dev,
 125                                         ip6_dev_loopback_xmit);
 126
 127                         if (skb->nh.ipv6h->hop_limit == 0) {
 128                                 IP6_INC_STATS(idev, IPSTATS_MIB_OUTDISCARDS);
 129                                 kfree_skb(skb);
 130                                 return 0;
 131                         }
 132                 }
 133
 134                 IP6_INC_STATS(idev, IPSTATS_MIB_OUTMCASTPKTS);
 135         }
 136
 137         return NF_HOOK(PF_INET6, NF_IP6_POST_ROUTING, skb,NULL, skb->dev,ip6_output_finish);
 138 }
 139
 140 int ip6_output(struct sk_buff *skb)
 141 {
 142         if ((skb->len > dst_mtu(skb->dst) && !skb_is_gso(skb)) ||
 143                                 dst_allfrag(skb->dst))
 144                 return ip6_fragment(skb, ip6_output2);
 145         else
 146                 return ip6_output2(skb);
 147 }
 148
 149 /*
 150  *      xmit an sk_buff (used by TCP)
 151  */
 152
 153 int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl,
 154              struct ipv6_txoptions *opt, int ipfragok)
 155 {
 156         struct ipv6_pinfo *np = inet6_sk(sk);
 157         struct in6_addr *first_hop = &fl->fl6_dst;
 158         struct dst_entry *dst = skb->dst;
 159         struct ipv6hdr *hdr;
 160         u8  proto = fl->proto;
 161         int seg_len = skb->len;
 162         int hlimit, tclass;
 163         u32 mtu;
 164
 165         if (opt) {
 166                 int head_room;
 167
 168                 /* First: exthdrs may take lots of space (~8K for now)
 169                    MAX_HEADER is not enough.
 170                  */
 171                 head_room = opt->opt_nflen + opt->opt_flen;
 172                 seg_len += head_room;
 173                 head_room += sizeof(struct ipv6hdr) + LL_RESERVED_SPACE(dst->dev);
 174
 175                 if (skb_headroom(skb) < head_room) {
 176                         struct sk_buff *skb2 = skb_realloc_headroom(skb, head_room);
 177                         if (skb2 == NULL) {
 178                                 IP6_INC_STATS(ip6_dst_idev(skb->dst),
 179                                               IPSTATS_MIB_OUTDISCARDS);
 180                                 kfree_skb(skb);
 181                                 return -ENOBUFS;
 182                         }
 183                         kfree_skb(skb);
 184                         skb = skb2;
 185                         if (sk)
 186                                 skb_set_owner_w(skb, sk);
 187                 }
 188                 if (opt->opt_flen)
 189                         ipv6_push_frag_opts(skb, opt, &proto);
 190                 if (opt->opt_nflen)
 191                         ipv6_push_nfrag_opts(skb, opt, &proto, &first_hop);
 192         }
 193
 194         hdr = skb->nh.ipv6h = (struct ipv6hdr*)skb_push(skb, sizeof(struct ipv6hdr));
 195
 196         /*
 197          *      Fill in the IPv6 header
 198          */
 199
 200         hlimit = -1;
 201         if (np)
 202                 hlimit = np->hop_limit;
 203         if (hlimit < 0)
 204                 hlimit = dst_metric(dst, RTAX_HOPLIMIT);
 205         if (hlimit < 0)
 206                 hlimit = ipv6_get_hoplimit(dst->dev);
 207
 208         tclass = -1;
 209         if (np)
 210                 tclass = np->tclass;
 211         if (tclass < 0)
 212                 tclass = 0;
 213
 214         *(__be32 *)hdr = htonl(0x60000000 | (tclass << 20)) | fl->fl6_flowlabel;
 215
 216         hdr->payload_len = htons(seg_len);
 217         hdr->nexthdr = proto;
 218         hdr->hop_limit = hlimit;
 219
 220         ipv6_addr_copy(&hdr->saddr, &fl->fl6_src);
 221         ipv6_addr_copy(&hdr->daddr, first_hop);
 222
 223         skb->priority = sk->sk_priority;
 224
 225         mtu = dst_mtu(dst);
 226         if ((skb->len <= mtu) || ipfragok || skb_is_gso(skb)) {
 227                 IP6_INC_STATS(ip6_dst_idev(skb->dst),
 228                               IPSTATS_MIB_OUTREQUESTS);
 229                 return NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, dst->dev,
 230                                 dst_output);
 231         }
 232
 233         if (net_ratelimit())
 234                 printk(KERN_DEBUG "IPv6: sending pkt_too_big to self\n");
 235         skb->dev = dst->dev;
 236         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, skb->dev);
 237         IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_FRAGFAILS);
 238         kfree_skb(skb);
 239         return -EMSGSIZE;
 240 }
 241
 242 EXPORT_SYMBOL(ip6_xmit);
 243
 244 /*
 245  *      To avoid extra problems ND packets are send through this
 246  *      routine. It's code duplication but I really want to avoid
 247  *      extra checks since ipv6_build_header is used by TCP (which
 248  *      is for us performance critical)
 249  */
 250
 251 int ip6_nd_hdr(struct sock *sk, struct sk_buff *skb, struct net_device *dev,
 252                struct in6_addr *saddr, struct in6_addr *daddr,
 253                int proto, int len)
 254 {
 255         struct ipv6_pinfo *np = inet6_sk(sk);
 256         struct ipv6hdr *hdr;
 257         int totlen;
 258
 259         skb->protocol = htons(ETH_P_IPV6);
 260         skb->dev = dev;
 261
 262         totlen = len + sizeof(struct ipv6hdr);
 263
 264         hdr = (struct ipv6hdr *) skb_put(skb, sizeof(struct ipv6hdr));
 265         skb->nh.ipv6h = hdr;
 266
 267         *(__be32*)hdr = htonl(0x60000000);
 268
 269         hdr->payload_len = htons(len);
 270         hdr->nexthdr = proto;
 271         hdr->hop_limit = np->hop_limit;
 272
 273         ipv6_addr_copy(&hdr->saddr, saddr);
 274         ipv6_addr_copy(&hdr->daddr, daddr);
 275
 276         return 0;
 277 }
 278
 279 static int ip6_call_ra_chain(struct sk_buff *skb, int sel)
 280 {
 281         struct ip6_ra_chain *ra;
 282         struct sock *last = NULL;
 283
 284         read_lock(&ip6_ra_lock);
 285         for (ra = ip6_ra_chain; ra; ra = ra->next) {
 286                 struct sock *sk = ra->sk;
 287                 if (sk && ra->sel == sel &&
 288                     (!sk->sk_bound_dev_if ||
 289                      sk->sk_bound_dev_if == skb->dev->ifindex)) {
 290                         if (last) {
 291                                 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
 292                                 if (skb2)
 293                                         rawv6_rcv(last, skb2);
 294                         }
 295                         last = sk;
 296                 }
 297         }
 298
 299         if (last) {
 300                 rawv6_rcv(last, skb);
 301                 read_unlock(&ip6_ra_lock);
 302                 return 1;
 303         }
 304         read_unlock(&ip6_ra_lock);
 305         return 0;
 306 }
 307
 308 static int ip6_forward_proxy_check(struct sk_buff *skb)
 309 {
 310         struct ipv6hdr *hdr = skb->nh.ipv6h;
 311         u8 nexthdr = hdr->nexthdr;
 312         int offset;
 313
 314         if (ipv6_ext_hdr(nexthdr)) {
 315                 offset = ipv6_skip_exthdr(skb, sizeof(*hdr), &nexthdr);
 316                 if (offset < 0)
 317                         return 0;
 318         } else
 319                 offset = sizeof(struct ipv6hdr);
 320
 321         if (nexthdr == IPPROTO_ICMPV6) {
 322                 struct icmp6hdr *icmp6;
 323
 324                 if (!pskb_may_pull(skb, skb->nh.raw + offset + 1 - skb->data))
 325                         return 0;
 326
 327                 icmp6 = (struct icmp6hdr *)(skb->nh.raw + offset);
 328
 329                 switch (icmp6->icmp6_type) {
 330                 case NDISC_ROUTER_SOLICITATION:
 331                 case NDISC_ROUTER_ADVERTISEMENT:
 332                 case NDISC_NEIGHBOUR_SOLICITATION:
 333                 case NDISC_NEIGHBOUR_ADVERTISEMENT:
 334                 case NDISC_REDIRECT:
 335                         /* For reaction involving unicast neighbor discovery
 336                          * message destined to the proxied address, pass it to
 337                          * input function.
 338                          */
 339                         return 1;
 340                 default:
 341                         break;
 342                 }
 343         }
 344
 345         /*
 346          * The proxying router can't forward traffic sent to a link-local
 347          * address, so signal the sender and discard the packet. This
 348          * behavior is clarified by the MIPv6 specification.
 349          */
 350         if (ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) {
 351                 dst_link_failure(skb);
 352                 return -1;
 353         }
 354
 355         return 0;
 356 }
 357
 358 static inline int ip6_forward_finish(struct sk_buff *skb)
 359 {
 360         return dst_output(skb);
 361 }
 362
 363 int ip6_forward(struct sk_buff *skb)
 364 {
 365         struct dst_entry *dst = skb->dst;
 366         struct ipv6hdr *hdr = skb->nh.ipv6h;
 367         struct inet6_skb_parm *opt = IP6CB(skb);
 368
 369         if (ipv6_devconf.forwarding == 0)
 370                 goto error;
 371
 372         if (!xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) {
 373                 IP6_INC_STATS(ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS);
 374                 goto drop;
 375         }
 376
 377         skb->ip_summed = CHECKSUM_NONE;
 378
 379         /*
 380          *      We DO NOT make any processing on
 381          *      RA packets, pushing them to user level AS IS
 382          *      without ane WARRANTY that application will be able
 383          *      to interpret them. The reason is that we
 384          *      cannot make anything clever here.
 385          *
 386          *      We are not end-node, so that if packet contains
 387          *      AH/ESP, we cannot make anything.
 388          *      Defragmentation also would be mistake, RA packets
 389          *      cannot be fragmented, because there is no warranty
 390          *      that different fragments will go along one path. --ANK
 391          */
 392         if (opt->ra) {
 393                 u8 *ptr = skb->nh.raw + opt->ra;
 394                 if (ip6_call_ra_chain(skb, (ptr[2]<<8) + ptr[3]))
 395                         return 0;
 396         }
 397
 398         /*
 399          *      check and decrement ttl
 400          */
 401         if (hdr->hop_limit <= 1) {
 402                 /* Force OUTPUT device used as source address */
 403                 skb->dev = dst->dev;
 404                 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
 405                             0, skb->dev);
 406                 IP6_INC_STATS_BH(ip6_dst_idev(dst), IPSTATS_MIB_INHDRERRORS);
 407
 408                 kfree_skb(skb);
 409                 return -ETIMEDOUT;
 410         }
 411
 412         /* XXX: idev->cnf.proxy_ndp? */
 413         if (ipv6_devconf.proxy_ndp &&
 414             pneigh_lookup(&nd_tbl, &hdr->daddr, skb->dev, 0)) {
 415                 int proxied = ip6_forward_proxy_check(skb);
 416                 if (proxied > 0)
 417                         return ip6_input(skb);
 418                 else if (proxied < 0) {
 419                         IP6_INC_STATS(ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS);
 420                         goto drop;
 421                 }
 422         }
 423
 424         if (!xfrm6_route_forward(skb)) {
 425                 IP6_INC_STATS(ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS);
 426                 goto drop;
 427         }
 428         dst = skb->dst;
 429
 430         /* IPv6 specs say nothing about it, but it is clear that we cannot
 431            send redirects to source routed frames.
 432          */
 433         if (skb->dev == dst->dev && dst->neighbour && opt->srcrt == 0) {
 434                 struct in6_addr *target = NULL;
 435                 struct rt6_info *rt;
 436                 struct neighbour *n = dst->neighbour;
 437
 438                 /*
 439                  *      incoming and outgoing devices are the same
 440                  *      send a redirect.
 441                  */
 442
 443                 rt = (struct rt6_info *) dst;
 444                 if ((rt->rt6i_flags & RTF_GATEWAY))
 445                         target = (struct in6_addr*)&n->primary_key;
 446                 else
 447                         target = &hdr->daddr;
 448
 449                 /* Limit redirects both by destination (here)
 450                    and by source (inside ndisc_send_redirect)
 451                  */
 452                 if (xrlim_allow(dst, 1*HZ))
 453                         ndisc_send_redirect(skb, n, target);
 454         } else if (ipv6_addr_type(&hdr->saddr)&(IPV6_ADDR_MULTICAST|IPV6_ADDR_LOOPBACK
 455                                                 |IPV6_ADDR_LINKLOCAL)) {
 456                 /* This check is security critical. */
 457                 goto error;
 458         }
 459
 460         if (skb->len > dst_mtu(dst)) {
 461                 /* Again, force OUTPUT device used as source address */
 462                 skb->dev = dst->dev;
 463                 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, dst_mtu(dst), skb->dev);
 464                 IP6_INC_STATS_BH(ip6_dst_idev(dst), IPSTATS_MIB_INTOOBIGERRORS);
 465                 IP6_INC_STATS_BH(ip6_dst_idev(dst), IPSTATS_MIB_FRAGFAILS);
 466                 kfree_skb(skb);
 467                 return -EMSGSIZE;
 468         }
 469
 470         if (skb_cow(skb, dst->dev->hard_header_len)) {
 471                 IP6_INC_STATS(ip6_dst_idev(dst), IPSTATS_MIB_OUTDISCARDS);
 472                 goto drop;
 473         }
 474
 475         hdr = skb->nh.ipv6h;
 476
 477         /* Mangling hops number delayed to point after skb COW */
 478
 479         hdr->hop_limit--;
 480
 481         IP6_INC_STATS_BH(ip6_dst_idev(dst), IPSTATS_MIB_OUTFORWDATAGRAMS);
 482         return NF_HOOK(PF_INET6,NF_IP6_FORWARD, skb, skb->dev, dst->dev, ip6_forward_finish);
 483
 484 error:
 485         IP6_INC_STATS_BH(ip6_dst_idev(dst), IPSTATS_MIB_INADDRERRORS);
 486 drop:
 487         kfree_skb(skb);
 488         return -EINVAL;
 489 }
 490
 491 static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from)
 492 {
 493         to->pkt_type = from->pkt_type;
 494         to->priority = from->priority;
 495         to->protocol = from->protocol;
 496         dst_release(to->dst);
 497         to->dst = dst_clone(from->dst);
 498         to->dev = from->dev;
 499         to->mark = from->mark;
 500
 501 #ifdef CONFIG_NET_SCHED
 502         to->tc_index = from->tc_index;
 503 #endif
 504 #ifdef CONFIG_NETFILTER
 505         /* Connection association is same as pre-frag packet */
 506         nf_conntrack_put(to->nfct);
 507         to->nfct = from->nfct;
 508         nf_conntrack_get(to->nfct);
 509         to->nfctinfo = from->nfctinfo;
 510 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
 511         nf_conntrack_put_reasm(to->nfct_reasm);
 512         to->nfct_reasm = from->nfct_reasm;
 513         nf_conntrack_get_reasm(to->nfct_reasm);
 514 #endif
 515 #ifdef CONFIG_BRIDGE_NETFILTER
 516         nf_bridge_put(to->nf_bridge);
 517         to->nf_bridge = from->nf_bridge;
 518         nf_bridge_get(to->nf_bridge);
 519 #endif
 520 #endif
 521         skb_copy_secmark(to, from);
 522 }
 523
 524 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr)
 525 {
 526         u16 offset = sizeof(struct ipv6hdr);
 527         struct ipv6_opt_hdr *exthdr = (struct ipv6_opt_hdr*)(skb->nh.ipv6h + 1);
 528         unsigned int packet_len = skb->tail - skb->nh.raw;
 529         int found_rhdr = 0;
 530         *nexthdr = &skb->nh.ipv6h->nexthdr;
 531
 532         while (offset + 1 <= packet_len) {
 533
 534                 switch (**nexthdr) {
 535
 536                 case NEXTHDR_HOP:
 537                         break;
 538                 case NEXTHDR_ROUTING:
 539                         found_rhdr = 1;
 540                         break;
 541                 case NEXTHDR_DEST:
 542 #ifdef CONFIG_IPV6_MIP6
 543                         if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
 544                                 break;
 545 #endif
 546                         if (found_rhdr)
 547                                 return offset;
 548                         break;
 549                 default :
 550                         return offset;
 551                 }
 552
 553                 offset += ipv6_optlen(exthdr);
 554                 *nexthdr = &exthdr->nexthdr;
 555                 exthdr = (struct ipv6_opt_hdr*)(skb->nh.raw + offset);
 556         }
 557
 558         return offset;
 559 }
 560 EXPORT_SYMBOL_GPL(ip6_find_1stfragopt);
 561
 562 static int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *))
 563 {
 564         struct net_device *dev;
 565         struct sk_buff *frag;
 566         struct rt6_info *rt = (struct rt6_info*)skb->dst;
 567         struct ipv6_pinfo *np = skb->sk ? inet6_sk(skb->sk) : NULL;
 568         struct ipv6hdr *tmp_hdr;
 569         struct frag_hdr *fh;
 570         unsigned int mtu, hlen, left, len;
 571         __be32 frag_id = 0;
 572         int ptr, offset = 0, err=0;
 573         u8 *prevhdr, nexthdr = 0;
 574
 575         dev = rt->u.dst.dev;
 576         hlen = ip6_find_1stfragopt(skb, &prevhdr);
 577         nexthdr = *prevhdr;
 578
 579         mtu = dst_mtu(&rt->u.dst);
 580         if (np && np->frag_size < mtu) {
 581                 if (np->frag_size)
 582                         mtu = np->frag_size;
 583         }
 584         mtu -= hlen + sizeof(struct frag_hdr);
 585
 586         if (skb_shinfo(skb)->frag_list) {
 587                 int first_len = skb_pagelen(skb);
 588
 589                 if (first_len - hlen > mtu ||
 590                     ((first_len - hlen) & 7) ||
 591                     skb_cloned(skb))
 592                         goto slow_path;
 593
 594                 for (frag = skb_shinfo(skb)->frag_list; frag; frag = frag->next) {
 595                         /* Correct geometry. */
 596                         if (frag->len > mtu ||
 597                             ((frag->len & 7) && frag->next) ||
 598                             skb_headroom(frag) < hlen)
 599                             goto slow_path;
 600
 601                         /* Partially cloned skb? */
 602                         if (skb_shared(frag))
 603                                 goto slow_path;
 604
 605                         BUG_ON(frag->sk);
 606                         if (skb->sk) {
 607                                 sock_hold(skb->sk);
 608                                 frag->sk = skb->sk;
 609                                 frag->destructor = sock_wfree;
 610                                 skb->truesize -= frag->truesize;
 611                         }
 612                 }
 613
 614                 err = 0;
 615                 offset = 0;
 616                 frag = skb_shinfo(skb)->frag_list;
 617                 skb_shinfo(skb)->frag_list = NULL;
 618                 /* BUILD HEADER */
 619
 620                 *prevhdr = NEXTHDR_FRAGMENT;
 621                 tmp_hdr = kmemdup(skb->nh.raw, hlen, GFP_ATOMIC);
 622                 if (!tmp_hdr) {
 623                         IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_FRAGFAILS);
 624                         return -ENOMEM;
 625                 }
 626
 627                 __skb_pull(skb, hlen);
 628                 fh = (struct frag_hdr*)__skb_push(skb, sizeof(struct frag_hdr));
 629                 skb->nh.raw = __skb_push(skb, hlen);
 630                 memcpy(skb->nh.raw, tmp_hdr, hlen);
 631
 632                 ipv6_select_ident(skb, fh);
 633                 fh->nexthdr = nexthdr;
 634                 fh->reserved = 0;
 635                 fh->frag_off = htons(IP6_MF);
 636                 frag_id = fh->identification;
 637
 638                 first_len = skb_pagelen(skb);
 639                 skb->data_len = first_len - skb_headlen(skb);
 640                 skb->len = first_len;
 641                 skb->nh.ipv6h->payload_len = htons(first_len - sizeof(struct ipv6hdr));
 642
 643                 dst_hold(&rt->u.dst);
 644
 645                 for (;;) {
 646                         /* Prepare header of the next frame,
 647                          * before previous one went down. */
 648                         if (frag) {
 649                                 frag->ip_summed = CHECKSUM_NONE;
 650                                 frag->h.raw = frag->data;
 651                                 fh = (struct frag_hdr*)__skb_push(frag, sizeof(struct frag_hdr));
 652                                 frag->nh.raw = __skb_push(frag, hlen);
 653                                 memcpy(frag->nh.raw, tmp_hdr, hlen);
 654                                 offset += skb->len - hlen - sizeof(struct frag_hdr);
 655                                 fh->nexthdr = nexthdr;
 656                                 fh->reserved = 0;
 657                                 fh->frag_off = htons(offset);
 658                                 if (frag->next != NULL)
 659                                         fh->frag_off |= htons(IP6_MF);
 660                                 fh->identification = frag_id;
 661                                 frag->nh.ipv6h->payload_len = htons(frag->len - sizeof(struct ipv6hdr));
 662                                 ip6_copy_metadata(frag, skb);
 663                         }
 664
 665                         err = output(skb);
 666                         if(!err)
 667                                 IP6_INC_STATS(ip6_dst_idev(&rt->u.dst), IPSTATS_MIB_FRAGCREATES);
 668
 669                         if (err || !frag)
 670                                 break;
 671
 672                         skb = frag;
 673                         frag = skb->next;
 674                         skb->next = NULL;
 675                 }
 676
 677                 kfree(tmp_hdr);
 678
 679                 if (err == 0) {
 680                         IP6_INC_STATS(ip6_dst_idev(&rt->u.dst), IPSTATS_MIB_FRAGOKS);
 681                         dst_release(&rt->u.dst);
 682                         return 0;
 683                 }
 684
 685                 while (frag) {
 686                         skb = frag->next;
 687                         kfree_skb(frag);
 688                         frag = skb;
 689                 }
 690
 691                 IP6_INC_STATS(ip6_dst_idev(&rt->u.dst), IPSTATS_MIB_FRAGFAILS);
 692                 dst_release(&rt->u.dst);
 693                 return err;
 694         }
 695
 696 slow_path:
 697         left = skb->len - hlen;         /* Space per frame */
 698         ptr = hlen;                     /* Where to start from */
 699
 700         /*
 701          *      Fragment the datagram.
 702          */
 703
 704         *prevhdr = NEXTHDR_FRAGMENT;
 705
 706         /*
 707          *      Keep copying data until we run out.
 708          */
 709         while(left > 0) {
 710                 len = left;
 711                 /* IF: it doesn't fit, use 'mtu' - the data space left */
 712                 if (len > mtu)
 713                         len = mtu;
 714                 /* IF: we are not sending upto and including the packet end
 715                    then align the next start on an eight byte boundary */
 716                 if (len < left) {
 717                         len &= ~7;
 718                 }
 719                 /*
 720                  *      Allocate buffer.
 721                  */
 722
 723                 if ((frag = alloc_skb(len+hlen+sizeof(struct frag_hdr)+LL_RESERVED_SPACE(rt->u.dst.dev), GFP_ATOMIC)) == NULL) {
 724                         NETDEBUG(KERN_INFO "IPv6: frag: no memory for new fragment!\n");
 725                         IP6_INC_STATS(ip6_dst_idev(skb->dst),
 726                                       IPSTATS_MIB_FRAGFAILS);
 727                         err = -ENOMEM;
 728                         goto fail;
 729                 }
 730
 731                 /*
 732                  *      Set up data on packet
 733                  */
 734
 735                 ip6_copy_metadata(frag, skb);
 736                 skb_reserve(frag, LL_RESERVED_SPACE(rt->u.dst.dev));
 737                 skb_put(frag, len + hlen + sizeof(struct frag_hdr));
 738                 frag->nh.raw = frag->data;
 739                 fh = (struct frag_hdr*)(frag->data + hlen);
 740                 frag->h.raw = frag->data + hlen + sizeof(struct frag_hdr);
 741
 742                 /*
 743                  *      Charge the memory for the fragment to any owner
 744                  *      it might possess
 745                  */
 746                 if (skb->sk)
 747                         skb_set_owner_w(frag, skb->sk);
 748
 749                 /*
 750                  *      Copy the packet header into the new buffer.
 751                  */
 752                 memcpy(frag->nh.raw, skb->data, hlen);
 753
 754                 /*
 755                  *      Build fragment header.
 756                  */
 757                 fh->nexthdr = nexthdr;
 758                 fh->reserved = 0;
 759                 if (!frag_id) {
 760                         ipv6_select_ident(skb, fh);
 761                         frag_id = fh->identification;
 762                 } else
 763                         fh->identification = frag_id;
 764
 765                 /*
 766                  *      Copy a block of the IP datagram.
 767                  */
 768                 if (skb_copy_bits(skb, ptr, frag->h.raw, len))
 769                         BUG();
 770                 left -= len;
 771
 772                 fh->frag_off = htons(offset);
 773                 if (left > 0)
 774                         fh->frag_off |= htons(IP6_MF);
 775                 frag->nh.ipv6h->payload_len = htons(frag->len - sizeof(struct ipv6hdr));
 776
 777                 ptr += len;
 778                 offset += len;
 779
 780                 /*
 781                  *      Put this fragment into the sending queue.
 782                  */
 783                 err = output(frag);
 784                 if (err)
 785                         goto fail;
 786
 787                 IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_FRAGCREATES);
 788         }
 789         IP6_INC_STATS(ip6_dst_idev(skb->dst),
 790                       IPSTATS_MIB_FRAGOKS);
 791         kfree_skb(skb);
 792         return err;
 793
 794 fail:
 795         IP6_INC_STATS(ip6_dst_idev(skb->dst),
 796                       IPSTATS_MIB_FRAGFAILS);
 797         kfree_skb(skb);
 798         return err;
 799 }
 800
 801 static inline int ip6_rt_check(struct rt6key *rt_key,
 802                                struct in6_addr *fl_addr,
 803                                struct in6_addr *addr_cache)
 804 {
 805         return ((rt_key->plen != 128 || !ipv6_addr_equal(fl_addr, &rt_key->addr)) &&
 806                 (addr_cache == NULL || !ipv6_addr_equal(fl_addr, addr_cache)));
 807 }
 808
 809 static struct dst_entry *ip6_sk_dst_check(struct sock *sk,
 810                                           struct dst_entry *dst,
 811                                           struct flowi *fl)
 812 {
 813         struct ipv6_pinfo *np = inet6_sk(sk);
 814         struct rt6_info *rt = (struct rt6_info *)dst;
 815
 816         if (!dst)
 817                 goto out;
 818
 819         /* Yes, checking route validity in not connected
 820          * case is not very simple. Take into account,
 821          * that we do not support routing by source, TOS,
 822          * and MSG_DONTROUTE            --ANK (980726)
 823          *
 824          * 1. ip6_rt_check(): If route was host route,
 825          *    check that cached destination is current.
 826          *    If it is network route, we still may
 827          *    check its validity using saved pointer
 828          *    to the last used address: daddr_cache.
 829          *    We do not want to save whole address now,
 830          *    (because main consumer of this service
 831          *    is tcp, which has not this problem),
 832          *    so that the last trick works only on connected
 833          *    sockets.
 834          * 2. oif also should be the same.
 835          */
 836         if (ip6_rt_check(&rt->rt6i_dst, &fl->fl6_dst, np->daddr_cache) ||
 837 #ifdef CONFIG_IPV6_SUBTREES
 838             ip6_rt_check(&rt->rt6i_src, &fl->fl6_src, np->saddr_cache) ||
 839 #endif
 840             (fl->oif && fl->oif != dst->dev->ifindex)) {
 841                 dst_release(dst);
 842                 dst = NULL;
 843         }
 844
 845 out:
 846         return dst;
 847 }
 848
 849 static int ip6_dst_lookup_tail(struct sock *sk,
 850                                struct dst_entry **dst, struct flowi *fl)
 851 {
 852         int err;
 853
 854         if (*dst == NULL)
 855                 *dst = ip6_route_output(sk, fl);
 856
 857         if ((err = (*dst)->error))
 858                 goto out_err_release;
 859
 860         if (ipv6_addr_any(&fl->fl6_src)) {
 861                 err = ipv6_get_saddr(*dst, &fl->fl6_dst, &fl->fl6_src);
 862                 if (err)
 863                         goto out_err_release;
 864         }
 865
 866 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
 867                 /*
 868                  * Here if the dst entry we've looked up
 869                  * has a neighbour entry that is in the INCOMPLETE
 870                  * state and the src address from the flow is
 871                  * marked as OPTIMISTIC, we release the found
 872                  * dst entry and replace it instead with the
 873                  * dst entry of the nexthop router
 874                  */
 875                 if (!((*dst)->neighbour->nud_state & NUD_VALID)) {
 876                         struct inet6_ifaddr *ifp;
 877                         struct flowi fl_gw;
 878                         int redirect;
 879
 880                         ifp = ipv6_get_ifaddr(&fl->fl6_src, (*dst)->dev, 1);
 881
 882                         redirect = (ifp && ifp->flags & IFA_F_OPTIMISTIC);
 883                         if (ifp)
 884                                 in6_ifa_put(ifp);
 885
 886                         if (redirect) {
 887                                 /*
 888                                  * We need to get the dst entry for the
 889                                  * default router instead
 890                                  */
 891                                 dst_release(*dst);
 892                                 memcpy(&fl_gw, fl, sizeof(struct flowi));
 893                                 memset(&fl_gw.fl6_dst, 0, sizeof(struct in6_addr));
 894                                 *dst = ip6_route_output(sk, &fl_gw);
 895                                 if ((err = (*dst)->error))
 896                                         goto out_err_release;
 897                         }
 898                 }
 899 #endif
 900
 901         return 0;
 902
 903 out_err_release:
 904         dst_release(*dst);
 905         *dst = NULL;
 906         return err;
 907 }
 908
 909 /**
 910  *      ip6_dst_lookup - perform route lookup on flow
 911  *      @sk: socket which provides route info
 912  *      @dst: pointer to dst_entry * for result
 913  *      @fl: flow to lookup
 914  *
 915  *      This function performs a route lookup on the given flow.
 916  *
 917  *      It returns zero on success, or a standard errno code on error.
 918  */
 919 int ip6_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi *fl)
 920 {
 921         *dst = NULL;
 922         return ip6_dst_lookup_tail(sk, dst, fl);
 923 }
 924 EXPORT_SYMBOL_GPL(ip6_dst_lookup);
 925
 926 /**
 927  *      ip6_sk_dst_lookup - perform socket cached route lookup on flow
 928  *      @sk: socket which provides the dst cache and route info
 929  *      @dst: pointer to dst_entry * for result
 930  *      @fl: flow to lookup
 931  *
 932  *      This function performs a route lookup on the given flow with the
 933  *      possibility of using the cached route in the socket if it is valid.
 934  *      It will take the socket dst lock when operating on the dst cache.
 935  *      As a result, this function can only be used in process context.
 936  *
 937  *      It returns zero on success, or a standard errno code on error.
 938  */
 939 int ip6_sk_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi *fl)
 940 {
 941         *dst = NULL;
 942         if (sk) {
 943                 *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie);
 944                 *dst = ip6_sk_dst_check(sk, *dst, fl);
 945         }
 946
 947         return ip6_dst_lookup_tail(sk, dst, fl);
 948 }
 949 EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup);
 950
 951 static inline int ip6_ufo_append_data(struct sock *sk,
 952                         int getfrag(void *from, char *to, int offset, int len,
 953                         int odd, struct sk_buff *skb),
 954                         void *from, int length, int hh_len, int fragheaderlen,
 955                         int transhdrlen, int mtu,unsigned int flags)
 956
 957 {
 958         struct sk_buff *skb;
 959         int err;
 960
 961         /* There is support for UDP large send offload by network
 962          * device, so create one single skb packet containing complete
 963          * udp datagram
 964          */
 965         if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) {
 966                 skb = sock_alloc_send_skb(sk,
 967                         hh_len + fragheaderlen + transhdrlen + 20,
 968                         (flags & MSG_DONTWAIT), &err);
 969                 if (skb == NULL)
 970                         return -ENOMEM;
 971
 972                 /* reserve space for Hardware header */
 973                 skb_reserve(skb, hh_len);
 974
 975                 /* create space for UDP/IP header */
 976                 skb_put(skb,fragheaderlen + transhdrlen);
 977
 978                 /* initialize network header pointer */
 979                 skb->nh.raw = skb->data;
 980
 981                 /* initialize protocol header pointer */
 982                 skb->h.raw = skb->data + fragheaderlen;
 983
 984                 skb->ip_summed = CHECKSUM_PARTIAL;
 985                 skb->csum = 0;
 986                 sk->sk_sndmsg_off = 0;
 987         }
 988
 989         err = skb_append_datato_frags(sk,skb, getfrag, from,
 990                                       (length - transhdrlen));
 991         if (!err) {
 992                 struct frag_hdr fhdr;
 993
 994                 /* specify the length of each IP datagram fragment*/
 995                 skb_shinfo(skb)->gso_size = mtu - fragheaderlen -
 996                                             sizeof(struct frag_hdr);
 997                 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
 998                 ipv6_select_ident(skb, &fhdr);
 999                 skb_shinfo(skb)->ip6_frag_id = fhdr.identification;
1000                 __skb_queue_tail(&sk->sk_write_queue, skb);
1001
1002                 return 0;
1003         }
1004         /* There is not enough support do UPD LSO,
1005          * so follow normal path
1006          */
1007         kfree_skb(skb);
1008
1009         return err;
1010 }
1011
1012 int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
1013         int offset, int len, int odd, struct sk_buff *skb),
1014         void *from, int length, int transhdrlen,
1015         int hlimit, int tclass, struct ipv6_txoptions *opt, struct flowi *fl,
1016         struct rt6_info *rt, unsigned int flags)
1017 {
1018         struct inet_sock *inet = inet_sk(sk);
1019         struct ipv6_pinfo *np = inet6_sk(sk);
1020         struct sk_buff *skb;
1021         unsigned int maxfraglen, fragheaderlen;
1022         int exthdrlen;
1023         int hh_len;
1024         int mtu;
1025         int copy;
1026         int err;
1027         int offset = 0;
1028         int csummode = CHECKSUM_NONE;
1029
1030         if (flags&MSG_PROBE)
1031                 return 0;
1032         if (skb_queue_empty(&sk->sk_write_queue)) {
1033                 /*
1034                  * setup for corking
1035                  */
1036                 if (opt) {
1037                         if (np->cork.opt == NULL) {
1038                                 np->cork.opt = kmalloc(opt->tot_len,
1039                                                        sk->sk_allocation);
1040                                 if (unlikely(np->cork.opt == NULL))
1041                                         return -ENOBUFS;
1042                         } else if (np->cork.opt->tot_len < opt->tot_len) {
1043                                 printk(KERN_DEBUG "ip6_append_data: invalid option length\n");
1044                                 return -EINVAL;
1045                         }
1046                         memcpy(np->cork.opt, opt, opt->tot_len);
1047                         inet->cork.flags |= IPCORK_OPT;
1048                         /* need source address above miyazawa*/
1049                 }
1050                 dst_hold(&rt->u.dst);
1051                 np->cork.rt = rt;
1052                 inet->cork.fl = *fl;
1053                 np->cork.hop_limit = hlimit;
1054                 np->cork.tclass = tclass;
1055                 mtu = dst_mtu(rt->u.dst.path);
1056                 if (np->frag_size < mtu) {
1057                         if (np->frag_size)
1058                                 mtu = np->frag_size;
1059                 }
1060                 inet->cork.fragsize = mtu;
1061                 if (dst_allfrag(rt->u.dst.path))
1062                         inet->cork.flags |= IPCORK_ALLFRAG;
1063                 inet->cork.length = 0;
1064                 sk->sk_sndmsg_page = NULL;
1065                 sk->sk_sndmsg_off = 0;
1066                 exthdrlen = rt->u.dst.header_len + (opt ? opt->opt_flen : 0);
1067                 length += exthdrlen;
1068                 transhdrlen += exthdrlen;
1069         } else {
1070                 rt = np->cork.rt;
1071                 fl = &inet->cork.fl;
1072                 if (inet->cork.flags & IPCORK_OPT)
1073                         opt = np->cork.opt;
1074                 transhdrlen = 0;
1075                 exthdrlen = 0;
1076                 mtu = inet->cork.fragsize;
1077         }
1078
1079         hh_len = LL_RESERVED_SPACE(rt->u.dst.dev);
1080
1081         fragheaderlen = sizeof(struct ipv6hdr) + rt->u.dst.nfheader_len + (opt ? opt->opt_nflen : 0);
1082         maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - sizeof(struct frag_hdr);
1083
1084         if (mtu <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN) {
1085                 if (inet->cork.length + length > sizeof(struct ipv6hdr) + IPV6_MAXPLEN - fragheaderlen) {
1086                         ipv6_local_error(sk, EMSGSIZE, fl, mtu-exthdrlen);
1087                         return -EMSGSIZE;
1088                 }
1089         }
1090
1091         /*
1092          * Let's try using as much space as possible.
1093          * Use MTU if total length of the message fits into the MTU.
1094          * Otherwise, we need to reserve fragment header and
1095          * fragment alignment (= 8-15 octects, in total).
1096          *
1097          * Note that we may need to "move" the data from the tail of
1098          * of the buffer to the new fragment when we split
1099          * the message.
1100          *
1101          * FIXME: It may be fragmented into multiple chunks
1102          *        at once if non-fragmentable extension headers
1103          *        are too large.
1104          * --yoshfuji
1105          */
1106
1107         inet->cork.length += length;
1108         if (((length > mtu) && (sk->sk_protocol == IPPROTO_UDP)) &&
1109             (rt->u.dst.dev->features & NETIF_F_UFO)) {
1110
1111                 err = ip6_ufo_append_data(sk, getfrag, from, length, hh_len,
1112                                           fragheaderlen, transhdrlen, mtu,
1113                                           flags);
1114                 if (err)
1115                         goto error;
1116                 return 0;
1117         }
1118
1119         if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL)
1120                 goto alloc_new_skb;
1121
1122         while (length > 0) {
1123                 /* Check if the remaining data fits into current packet. */
1124                 copy = (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len;
1125                 if (copy < length)
1126                         copy = maxfraglen - skb->len;
1127
1128                 if (copy <= 0) {
1129                         char *data;
1130                         unsigned int datalen;
1131                         unsigned int fraglen;
1132                         unsigned int fraggap;
1133                         unsigned int alloclen;
1134                         struct sk_buff *skb_prev;
1135 alloc_new_skb:
1136                         skb_prev = skb;
1137
1138                         /* There's no room in the current skb */
1139                         if (skb_prev)
1140                                 fraggap = skb_prev->len - maxfraglen;
1141                         else
1142                                 fraggap = 0;
1143
1144                         /*
1145                          * If remaining data exceeds the mtu,
1146                          * we know we need more fragment(s).
1147                          */
1148                         datalen = length + fraggap;
1149                         if (datalen > (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen)
1150                                 datalen = maxfraglen - fragheaderlen;
1151
1152                         fraglen = datalen + fragheaderlen;
1153                         if ((flags & MSG_MORE) &&
1154                             !(rt->u.dst.dev->features&NETIF_F_SG))
1155                                 alloclen = mtu;
1156                         else
1157                                 alloclen = datalen + fragheaderlen;
1158
1159                         /*
1160                          * The last fragment gets additional space at tail.
1161                          * Note: we overallocate on fragments with MSG_MODE
1162                          * because we have no idea if we're the last one.
1163                          */
1164                         if (datalen == length + fraggap)
1165                                 alloclen += rt->u.dst.trailer_len;
1166
1167                         /*
1168                          * We just reserve space for fragment header.
1169                          * Note: this may be overallocation if the message
1170                          * (without MSG_MORE) fits into the MTU.
1171                          */
1172                         alloclen += sizeof(struct frag_hdr);
1173
1174                         if (transhdrlen) {
1175                                 skb = sock_alloc_send_skb(sk,
1176                                                 alloclen + hh_len,
1177                                                 (flags & MSG_DONTWAIT), &err);
1178                         } else {
1179                                 skb = NULL;
1180                                 if (atomic_read(&sk->sk_wmem_alloc) <=
1181                                     2 * sk->sk_sndbuf)
1182                                         skb = sock_wmalloc(sk,
1183                                                            alloclen + hh_len, 1,
1184                                                            sk->sk_allocation);
1185                                 if (unlikely(skb == NULL))
1186                                         err = -ENOBUFS;
1187                         }
1188                         if (skb == NULL)
1189                                 goto error;
1190                         /*
1191                          *      Fill in the control structures
1192                          */
1193                         skb->ip_summed = csummode;
1194                         skb->csum = 0;
1195                         /* reserve for fragmentation */
1196                         skb_reserve(skb, hh_len+sizeof(struct frag_hdr));
1197
1198                         /*
1199                          *      Find where to start putting bytes
1200                          */
1201                         data = skb_put(skb, fraglen);
1202                         skb->nh.raw = data + exthdrlen;
1203                         data += fragheaderlen;
1204                         skb->h.raw = data + exthdrlen;
1205
1206                         if (fraggap) {
1207                                 skb->csum = skb_copy_and_csum_bits(
1208                                         skb_prev, maxfraglen,
1209                                         data + transhdrlen, fraggap, 0);
1210                                 skb_prev->csum = csum_sub(skb_prev->csum,
1211                                                           skb->csum);
1212                                 data += fraggap;
1213                                 pskb_trim_unique(skb_prev, maxfraglen);
1214                         }
1215                         copy = datalen - transhdrlen - fraggap;
1216                         if (copy < 0) {
1217                                 err = -EINVAL;
1218                                 kfree_skb(skb);
1219                                 goto error;
1220                         } else if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) {
1221                                 err = -EFAULT;
1222                                 kfree_skb(skb);
1223                                 goto error;
1224                         }
1225
1226                         offset += copy;
1227                         length -= datalen - fraggap;
1228                         transhdrlen = 0;
1229                         exthdrlen = 0;
1230                         csummode = CHECKSUM_NONE;
1231
1232                         /*
1233                          * Put the packet on the pending queue
1234                          */
1235                         __skb_queue_tail(&sk->sk_write_queue, skb);
1236                         continue;
1237                 }
1238
1239                 if (copy > length)
1240                         copy = length;
1241
1242                 if (!(rt->u.dst.dev->features&NETIF_F_SG)) {
1243                         unsigned int off;
1244
1245                         off = skb->len;
1246                         if (getfrag(from, skb_put(skb, copy),
1247                                                 offset, copy, off, skb) < 0) {
1248                                 __skb_trim(skb, off);
1249                                 err = -EFAULT;
1250                                 goto error;
1251                         }
1252                 } else {
1253                         int i = skb_shinfo(skb)->nr_frags;
1254                         skb_frag_t *frag = &skb_shinfo(skb)->frags[i-1];
1255                         struct page *page = sk->sk_sndmsg_page;
1256                         int off = sk->sk_sndmsg_off;
1257                         unsigned int left;
1258
1259                         if (page && (left = PAGE_SIZE - off) > 0) {
1260                                 if (copy >= left)
1261                                         copy = left;
1262                                 if (page != frag->page) {
1263                                         if (i == MAX_SKB_FRAGS) {
1264                                                 err = -EMSGSIZE;
1265                                                 goto error;
1266                                         }
1267                                         get_page(page);
1268                                         skb_fill_page_desc(skb, i, page, sk->sk_sndmsg_off, 0);
1269                                         frag = &skb_shinfo(skb)->frags[i];
1270                                 }
1271                         } else if(i < MAX_SKB_FRAGS) {
1272                                 if (copy > PAGE_SIZE)
1273                                         copy = PAGE_SIZE;
1274                                 page = alloc_pages(sk->sk_allocation, 0);
1275                                 if (page == NULL) {
1276                                         err = -ENOMEM;
1277                                         goto error;
1278                                 }
1279                                 sk->sk_sndmsg_page = page;
1280                                 sk->sk_sndmsg_off = 0;
1281
1282                                 skb_fill_page_desc(skb, i, page, 0, 0);
1283                                 frag = &skb_shinfo(skb)->frags[i];
1284                                 skb->truesize += PAGE_SIZE;
1285                                 atomic_add(PAGE_SIZE, &sk->sk_wmem_alloc);
1286                         } else {
1287                                 err = -EMSGSIZE;
1288                                 goto error;
1289                         }
1290                         if (getfrag(from, page_address(frag->page)+frag->page_offset+frag->size, offset, copy, skb->len, skb) < 0) {
1291                                 err = -EFAULT;
1292                                 goto error;
1293                         }
1294                         sk->sk_sndmsg_off += copy;
1295                         frag->size += copy;
1296                         skb->len += copy;
1297                         skb->data_len += copy;
1298                 }
1299                 offset += copy;
1300                 length -= copy;
1301         }
1302         return 0;
1303 error:
1304         inet->cork.length -= length;
1305         IP6_INC_STATS(rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS);
1306         return err;
1307 }
1308
1309 int ip6_push_pending_frames(struct sock *sk)
1310 {
1311         struct sk_buff *skb, *tmp_skb;
1312         struct sk_buff **tail_skb;
1313         struct in6_addr final_dst_buf, *final_dst = &final_dst_buf;
1314         struct inet_sock *inet = inet_sk(sk);
1315         struct ipv6_pinfo *np = inet6_sk(sk);
1316         struct ipv6hdr *hdr;
1317         struct ipv6_txoptions *opt = np->cork.opt;
1318         struct rt6_info *rt = np->cork.rt;
1319         struct flowi *fl = &inet->cork.fl;
1320         unsigned char proto = fl->proto;
1321         int err = 0;
1322
1323         if ((skb = __skb_dequeue(&sk->sk_write_queue)) == NULL)
1324                 goto out;
1325         tail_skb = &(skb_shinfo(skb)->frag_list);
1326
1327         /* move skb->data to ip header from ext header */
1328         if (skb->data < skb->nh.raw)
1329                 __skb_pull(skb, skb->nh.raw - skb->data);
1330         while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) {
1331                 __skb_pull(tmp_skb, skb->h.raw - skb->nh.raw);
1332                 *tail_skb = tmp_skb;
1333                 tail_skb = &(tmp_skb->next);
1334                 skb->len += tmp_skb->len;
1335                 skb->data_len += tmp_skb->len;
1336                 skb->truesize += tmp_skb->truesize;
1337                 __sock_put(tmp_skb->sk);
1338                 tmp_skb->destructor = NULL;
1339                 tmp_skb->sk = NULL;
1340         }
1341
1342         ipv6_addr_copy(final_dst, &fl->fl6_dst);
1343         __skb_pull(skb, skb->h.raw - skb->nh.raw);
1344         if (opt && opt->opt_flen)
1345                 ipv6_push_frag_opts(skb, opt, &proto);
1346         if (opt && opt->opt_nflen)
1347                 ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst);
1348
1349         skb->nh.ipv6h = hdr = (struct ipv6hdr*) skb_push(skb, sizeof(struct ipv6hdr));
1350
1351         *(__be32*)hdr = fl->fl6_flowlabel |
1352                      htonl(0x60000000 | ((int)np->cork.tclass << 20));
1353
1354         if (skb->len <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN)
1355                 hdr->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
1356         else
1357                 hdr->payload_len = 0;
1358         hdr->hop_limit = np->cork.hop_limit;
1359         hdr->nexthdr = proto;
1360         ipv6_addr_copy(&hdr->saddr, &fl->fl6_src);
1361         ipv6_addr_copy(&hdr->daddr, final_dst);
1362
1363         skb->priority = sk->sk_priority;
1364
1365         skb->dst = dst_clone(&rt->u.dst);
1366         IP6_INC_STATS(rt->rt6i_idev, IPSTATS_MIB_OUTREQUESTS);
1367         err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, skb->dst->dev, dst_output);
1368         if (err) {
1369                 if (err > 0)
1370                         err = np->recverr ? net_xmit_errno(err) : 0;
1371                 if (err)
1372                         goto error;
1373         }
1374
1375 out:
1376         inet->cork.flags &= ~IPCORK_OPT;
1377         kfree(np->cork.opt);
1378         np->cork.opt = NULL;
1379         if (np->cork.rt) {
1380                 dst_release(&np->cork.rt->u.dst);
1381                 np->cork.rt = NULL;
1382                 inet->cork.flags &= ~IPCORK_ALLFRAG;
1383         }
1384         memset(&inet->cork.fl, 0, sizeof(inet->cork.fl));
1385         return err;
1386 error:
1387         goto out;
1388 }
1389
1390 void ip6_flush_pending_frames(struct sock *sk)
1391 {
1392         struct inet_sock *inet = inet_sk(sk);
1393         struct ipv6_pinfo *np = inet6_sk(sk);
1394         struct sk_buff *skb;
1395
1396         while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) {
1397                 IP6_INC_STATS(ip6_dst_idev(skb->dst),
1398                               IPSTATS_MIB_OUTDISCARDS);
1399                 kfree_skb(skb);
1400         }
1401
1402         inet->cork.flags &= ~IPCORK_OPT;
1403
1404         kfree(np->cork.opt);
1405         np->cork.opt = NULL;
1406         if (np->cork.rt) {
1407                 dst_release(&np->cork.rt->u.dst);
1408                 np->cork.rt = NULL;
1409                 inet->cork.flags &= ~IPCORK_ALLFRAG;
1410         }
1411         memset(&inet->cork.fl, 0, sizeof(inet->cork.fl));
1412 }