err.no Git - linux-2.6/blob - net/ipv6/ip6_output.c

   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, skb_network_offset(newskb));
  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(&ipv6_hdr(skb)->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, &ipv6_hdr(skb)->daddr,
 116                                         &ipv6_hdr(skb)->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 (ipv6_hdr(skb)->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         skb_push(skb, sizeof(struct ipv6hdr));
 195         skb_reset_network_header(skb);
 196         hdr = ipv6_hdr(skb);
 197
 198         /*
 199          *      Fill in the IPv6 header
 200          */
 201
 202         hlimit = -1;
 203         if (np)
 204                 hlimit = np->hop_limit;
 205         if (hlimit < 0)
 206                 hlimit = dst_metric(dst, RTAX_HOPLIMIT);
 207         if (hlimit < 0)
 208                 hlimit = ipv6_get_hoplimit(dst->dev);
 209
 210         tclass = -1;
 211         if (np)
 212                 tclass = np->tclass;
 213         if (tclass < 0)
 214                 tclass = 0;
 215
 216         *(__be32 *)hdr = htonl(0x60000000 | (tclass << 20)) | fl->fl6_flowlabel;
 217
 218         hdr->payload_len = htons(seg_len);
 219         hdr->nexthdr = proto;
 220         hdr->hop_limit = hlimit;
 221
 222         ipv6_addr_copy(&hdr->saddr, &fl->fl6_src);
 223         ipv6_addr_copy(&hdr->daddr, first_hop);
 224
 225         skb->priority = sk->sk_priority;
 226
 227         mtu = dst_mtu(dst);
 228         if ((skb->len <= mtu) || ipfragok || skb_is_gso(skb)) {
 229                 IP6_INC_STATS(ip6_dst_idev(skb->dst),
 230                               IPSTATS_MIB_OUTREQUESTS);
 231                 return NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, dst->dev,
 232                                 dst_output);
 233         }
 234
 235         if (net_ratelimit())
 236                 printk(KERN_DEBUG "IPv6: sending pkt_too_big to self\n");
 237         skb->dev = dst->dev;
 238         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, skb->dev);
 239         IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_FRAGFAILS);
 240         kfree_skb(skb);
 241         return -EMSGSIZE;
 242 }
 243
 244 EXPORT_SYMBOL(ip6_xmit);
 245
 246 /*
 247  *      To avoid extra problems ND packets are send through this
 248  *      routine. It's code duplication but I really want to avoid
 249  *      extra checks since ipv6_build_header is used by TCP (which
 250  *      is for us performance critical)
 251  */
 252
 253 int ip6_nd_hdr(struct sock *sk, struct sk_buff *skb, struct net_device *dev,
 254                struct in6_addr *saddr, struct in6_addr *daddr,
 255                int proto, int len)
 256 {
 257         struct ipv6_pinfo *np = inet6_sk(sk);
 258         struct ipv6hdr *hdr;
 259         int totlen;
 260
 261         skb->protocol = htons(ETH_P_IPV6);
 262         skb->dev = dev;
 263
 264         totlen = len + sizeof(struct ipv6hdr);
 265
 266         skb->nh.raw = skb_put(skb, sizeof(struct ipv6hdr));
 267         hdr = ipv6_hdr(skb);
 268
 269         *(__be32*)hdr = htonl(0x60000000);
 270
 271         hdr->payload_len = htons(len);
 272         hdr->nexthdr = proto;
 273         hdr->hop_limit = np->hop_limit;
 274
 275         ipv6_addr_copy(&hdr->saddr, saddr);
 276         ipv6_addr_copy(&hdr->daddr, daddr);
 277
 278         return 0;
 279 }
 280
 281 static int ip6_call_ra_chain(struct sk_buff *skb, int sel)
 282 {
 283         struct ip6_ra_chain *ra;
 284         struct sock *last = NULL;
 285
 286         read_lock(&ip6_ra_lock);
 287         for (ra = ip6_ra_chain; ra; ra = ra->next) {
 288                 struct sock *sk = ra->sk;
 289                 if (sk && ra->sel == sel &&
 290                     (!sk->sk_bound_dev_if ||
 291                      sk->sk_bound_dev_if == skb->dev->ifindex)) {
 292                         if (last) {
 293                                 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
 294                                 if (skb2)
 295                                         rawv6_rcv(last, skb2);
 296                         }
 297                         last = sk;
 298                 }
 299         }
 300
 301         if (last) {
 302                 rawv6_rcv(last, skb);
 303                 read_unlock(&ip6_ra_lock);
 304                 return 1;
 305         }
 306         read_unlock(&ip6_ra_lock);
 307         return 0;
 308 }
 309
 310 static int ip6_forward_proxy_check(struct sk_buff *skb)
 311 {
 312         struct ipv6hdr *hdr = ipv6_hdr(skb);
 313         u8 nexthdr = hdr->nexthdr;
 314         int offset;
 315
 316         if (ipv6_ext_hdr(nexthdr)) {
 317                 offset = ipv6_skip_exthdr(skb, sizeof(*hdr), &nexthdr);
 318                 if (offset < 0)
 319                         return 0;
 320         } else
 321                 offset = sizeof(struct ipv6hdr);
 322
 323         if (nexthdr == IPPROTO_ICMPV6) {
 324                 struct icmp6hdr *icmp6;
 325
 326                 if (!pskb_may_pull(skb, (skb_network_header(skb) +
 327                                          offset + 1 - skb->data)))
 328                         return 0;
 329
 330                 icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset);
 331
 332                 switch (icmp6->icmp6_type) {
 333                 case NDISC_ROUTER_SOLICITATION:
 334                 case NDISC_ROUTER_ADVERTISEMENT:
 335                 case NDISC_NEIGHBOUR_SOLICITATION:
 336                 case NDISC_NEIGHBOUR_ADVERTISEMENT:
 337                 case NDISC_REDIRECT:
 338                         /* For reaction involving unicast neighbor discovery
 339                          * message destined to the proxied address, pass it to
 340                          * input function.
 341                          */
 342                         return 1;
 343                 default:
 344                         break;
 345                 }
 346         }
 347
 348         /*
 349          * The proxying router can't forward traffic sent to a link-local
 350          * address, so signal the sender and discard the packet. This
 351          * behavior is clarified by the MIPv6 specification.
 352          */
 353         if (ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) {
 354                 dst_link_failure(skb);
 355                 return -1;
 356         }
 357
 358         return 0;
 359 }
 360
 361 static inline int ip6_forward_finish(struct sk_buff *skb)
 362 {
 363         return dst_output(skb);
 364 }
 365
 366 int ip6_forward(struct sk_buff *skb)
 367 {
 368         struct dst_entry *dst = skb->dst;
 369         struct ipv6hdr *hdr = ipv6_hdr(skb);
 370         struct inet6_skb_parm *opt = IP6CB(skb);
 371
 372         if (ipv6_devconf.forwarding == 0)
 373                 goto error;
 374
 375         if (!xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) {
 376                 IP6_INC_STATS(ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS);
 377                 goto drop;
 378         }
 379
 380         skb->ip_summed = CHECKSUM_NONE;
 381
 382         /*
 383          *      We DO NOT make any processing on
 384          *      RA packets, pushing them to user level AS IS
 385          *      without ane WARRANTY that application will be able
 386          *      to interpret them. The reason is that we
 387          *      cannot make anything clever here.
 388          *
 389          *      We are not end-node, so that if packet contains
 390          *      AH/ESP, we cannot make anything.
 391          *      Defragmentation also would be mistake, RA packets
 392          *      cannot be fragmented, because there is no warranty
 393          *      that different fragments will go along one path. --ANK
 394          */
 395         if (opt->ra) {
 396                 u8 *ptr = skb_network_header(skb) + opt->ra;
 397                 if (ip6_call_ra_chain(skb, (ptr[2]<<8) + ptr[3]))
 398                         return 0;
 399         }
 400
 401         /*
 402          *      check and decrement ttl
 403          */
 404         if (hdr->hop_limit <= 1) {
 405                 /* Force OUTPUT device used as source address */
 406                 skb->dev = dst->dev;
 407                 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
 408                             0, skb->dev);
 409                 IP6_INC_STATS_BH(ip6_dst_idev(dst), IPSTATS_MIB_INHDRERRORS);
 410
 411                 kfree_skb(skb);
 412                 return -ETIMEDOUT;
 413         }
 414
 415         /* XXX: idev->cnf.proxy_ndp? */
 416         if (ipv6_devconf.proxy_ndp &&
 417             pneigh_lookup(&nd_tbl, &hdr->daddr, skb->dev, 0)) {
 418                 int proxied = ip6_forward_proxy_check(skb);
 419                 if (proxied > 0)
 420                         return ip6_input(skb);
 421                 else if (proxied < 0) {
 422                         IP6_INC_STATS(ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS);
 423                         goto drop;
 424                 }
 425         }
 426
 427         if (!xfrm6_route_forward(skb)) {
 428                 IP6_INC_STATS(ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS);
 429                 goto drop;
 430         }
 431         dst = skb->dst;
 432
 433         /* IPv6 specs say nothing about it, but it is clear that we cannot
 434            send redirects to source routed frames.
 435          */
 436         if (skb->dev == dst->dev && dst->neighbour && opt->srcrt == 0) {
 437                 struct in6_addr *target = NULL;
 438                 struct rt6_info *rt;
 439                 struct neighbour *n = dst->neighbour;
 440
 441                 /*
 442                  *      incoming and outgoing devices are the same
 443                  *      send a redirect.
 444                  */
 445
 446                 rt = (struct rt6_info *) dst;
 447                 if ((rt->rt6i_flags & RTF_GATEWAY))
 448                         target = (struct in6_addr*)&n->primary_key;
 449                 else
 450                         target = &hdr->daddr;
 451
 452                 /* Limit redirects both by destination (here)
 453                    and by source (inside ndisc_send_redirect)
 454                  */
 455                 if (xrlim_allow(dst, 1*HZ))
 456                         ndisc_send_redirect(skb, n, target);
 457         } else if (ipv6_addr_type(&hdr->saddr)&(IPV6_ADDR_MULTICAST|IPV6_ADDR_LOOPBACK
 458                                                 |IPV6_ADDR_LINKLOCAL)) {
 459                 /* This check is security critical. */
 460                 goto error;
 461         }
 462
 463         if (skb->len > dst_mtu(dst)) {
 464                 /* Again, force OUTPUT device used as source address */
 465                 skb->dev = dst->dev;
 466                 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, dst_mtu(dst), skb->dev);
 467                 IP6_INC_STATS_BH(ip6_dst_idev(dst), IPSTATS_MIB_INTOOBIGERRORS);
 468                 IP6_INC_STATS_BH(ip6_dst_idev(dst), IPSTATS_MIB_FRAGFAILS);
 469                 kfree_skb(skb);
 470                 return -EMSGSIZE;
 471         }
 472
 473         if (skb_cow(skb, dst->dev->hard_header_len)) {
 474                 IP6_INC_STATS(ip6_dst_idev(dst), IPSTATS_MIB_OUTDISCARDS);
 475                 goto drop;
 476         }
 477
 478         hdr = ipv6_hdr(skb);
 479
 480         /* Mangling hops number delayed to point after skb COW */
 481
 482         hdr->hop_limit--;
 483
 484         IP6_INC_STATS_BH(ip6_dst_idev(dst), IPSTATS_MIB_OUTFORWDATAGRAMS);
 485         return NF_HOOK(PF_INET6,NF_IP6_FORWARD, skb, skb->dev, dst->dev, ip6_forward_finish);
 486
 487 error:
 488         IP6_INC_STATS_BH(ip6_dst_idev(dst), IPSTATS_MIB_INADDRERRORS);
 489 drop:
 490         kfree_skb(skb);
 491         return -EINVAL;
 492 }
 493
 494 static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from)
 495 {
 496         to->pkt_type = from->pkt_type;
 497         to->priority = from->priority;
 498         to->protocol = from->protocol;
 499         dst_release(to->dst);
 500         to->dst = dst_clone(from->dst);
 501         to->dev = from->dev;
 502         to->mark = from->mark;
 503
 504 #ifdef CONFIG_NET_SCHED
 505         to->tc_index = from->tc_index;
 506 #endif
 507         nf_copy(to, from);
 508         skb_copy_secmark(to, from);
 509 }
 510
 511 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr)
 512 {
 513         u16 offset = sizeof(struct ipv6hdr);
 514         struct ipv6_opt_hdr *exthdr =
 515                                 (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
 516         unsigned int packet_len = skb->tail - skb_network_header(skb);
 517         int found_rhdr = 0;
 518         *nexthdr = &ipv6_hdr(skb)->nexthdr;
 519
 520         while (offset + 1 <= packet_len) {
 521
 522                 switch (**nexthdr) {
 523
 524                 case NEXTHDR_HOP:
 525                         break;
 526                 case NEXTHDR_ROUTING:
 527                         found_rhdr = 1;
 528                         break;
 529                 case NEXTHDR_DEST:
 530 #ifdef CONFIG_IPV6_MIP6
 531                         if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
 532                                 break;
 533 #endif
 534                         if (found_rhdr)
 535                                 return offset;
 536                         break;
 537                 default :
 538                         return offset;
 539                 }
 540
 541                 offset += ipv6_optlen(exthdr);
 542                 *nexthdr = &exthdr->nexthdr;
 543                 exthdr = (struct ipv6_opt_hdr *)(skb_network_header(skb) +
 544                                                  offset);
 545         }
 546
 547         return offset;
 548 }
 549 EXPORT_SYMBOL_GPL(ip6_find_1stfragopt);
 550
 551 static int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *))
 552 {
 553         struct net_device *dev;
 554         struct sk_buff *frag;
 555         struct rt6_info *rt = (struct rt6_info*)skb->dst;
 556         struct ipv6_pinfo *np = skb->sk ? inet6_sk(skb->sk) : NULL;
 557         struct ipv6hdr *tmp_hdr;
 558         struct frag_hdr *fh;
 559         unsigned int mtu, hlen, left, len;
 560         __be32 frag_id = 0;
 561         int ptr, offset = 0, err=0;
 562         u8 *prevhdr, nexthdr = 0;
 563
 564         dev = rt->u.dst.dev;
 565         hlen = ip6_find_1stfragopt(skb, &prevhdr);
 566         nexthdr = *prevhdr;
 567
 568         mtu = dst_mtu(&rt->u.dst);
 569         if (np && np->frag_size < mtu) {
 570                 if (np->frag_size)
 571                         mtu = np->frag_size;
 572         }
 573         mtu -= hlen + sizeof(struct frag_hdr);
 574
 575         if (skb_shinfo(skb)->frag_list) {
 576                 int first_len = skb_pagelen(skb);
 577
 578                 if (first_len - hlen > mtu ||
 579                     ((first_len - hlen) & 7) ||
 580                     skb_cloned(skb))
 581                         goto slow_path;
 582
 583                 for (frag = skb_shinfo(skb)->frag_list; frag; frag = frag->next) {
 584                         /* Correct geometry. */
 585                         if (frag->len > mtu ||
 586                             ((frag->len & 7) && frag->next) ||
 587                             skb_headroom(frag) < hlen)
 588                             goto slow_path;
 589
 590                         /* Partially cloned skb? */
 591                         if (skb_shared(frag))
 592                                 goto slow_path;
 593
 594                         BUG_ON(frag->sk);
 595                         if (skb->sk) {
 596                                 sock_hold(skb->sk);
 597                                 frag->sk = skb->sk;
 598                                 frag->destructor = sock_wfree;
 599                                 skb->truesize -= frag->truesize;
 600                         }
 601                 }
 602
 603                 err = 0;
 604                 offset = 0;
 605                 frag = skb_shinfo(skb)->frag_list;
 606                 skb_shinfo(skb)->frag_list = NULL;
 607                 /* BUILD HEADER */
 608
 609                 *prevhdr = NEXTHDR_FRAGMENT;
 610                 tmp_hdr = kmemdup(skb_network_header(skb), hlen, GFP_ATOMIC);
 611                 if (!tmp_hdr) {
 612                         IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_FRAGFAILS);
 613                         return -ENOMEM;
 614                 }
 615
 616                 __skb_pull(skb, hlen);
 617                 fh = (struct frag_hdr*)__skb_push(skb, sizeof(struct frag_hdr));
 618                 __skb_push(skb, hlen);
 619                 skb_reset_network_header(skb);
 620                 memcpy(skb_network_header(skb), tmp_hdr, hlen);
 621
 622                 ipv6_select_ident(skb, fh);
 623                 fh->nexthdr = nexthdr;
 624                 fh->reserved = 0;
 625                 fh->frag_off = htons(IP6_MF);
 626                 frag_id = fh->identification;
 627
 628                 first_len = skb_pagelen(skb);
 629                 skb->data_len = first_len - skb_headlen(skb);
 630                 skb->len = first_len;
 631                 ipv6_hdr(skb)->payload_len = htons(first_len -
 632                                                    sizeof(struct ipv6hdr));
 633
 634                 dst_hold(&rt->u.dst);
 635
 636                 for (;;) {
 637                         /* Prepare header of the next frame,
 638                          * before previous one went down. */
 639                         if (frag) {
 640                                 frag->ip_summed = CHECKSUM_NONE;
 641                                 skb_reset_transport_header(frag);
 642                                 fh = (struct frag_hdr*)__skb_push(frag, sizeof(struct frag_hdr));
 643                                 __skb_push(frag, hlen);
 644                                 skb_reset_network_header(frag);
 645                                 memcpy(skb_network_header(frag), tmp_hdr,
 646                                        hlen);
 647                                 offset += skb->len - hlen - sizeof(struct frag_hdr);
 648                                 fh->nexthdr = nexthdr;
 649                                 fh->reserved = 0;
 650                                 fh->frag_off = htons(offset);
 651                                 if (frag->next != NULL)
 652                                         fh->frag_off |= htons(IP6_MF);
 653                                 fh->identification = frag_id;
 654                                 ipv6_hdr(frag)->payload_len =
 655                                                 htons(frag->len -
 656                                                       sizeof(struct ipv6hdr));
 657                                 ip6_copy_metadata(frag, skb);
 658                         }
 659
 660                         err = output(skb);
 661                         if(!err)
 662                                 IP6_INC_STATS(ip6_dst_idev(&rt->u.dst), IPSTATS_MIB_FRAGCREATES);
 663
 664                         if (err || !frag)
 665                                 break;
 666
 667                         skb = frag;
 668                         frag = skb->next;
 669                         skb->next = NULL;
 670                 }
 671
 672                 kfree(tmp_hdr);
 673
 674                 if (err == 0) {
 675                         IP6_INC_STATS(ip6_dst_idev(&rt->u.dst), IPSTATS_MIB_FRAGOKS);
 676                         dst_release(&rt->u.dst);
 677                         return 0;
 678                 }
 679
 680                 while (frag) {
 681                         skb = frag->next;
 682                         kfree_skb(frag);
 683                         frag = skb;
 684                 }
 685
 686                 IP6_INC_STATS(ip6_dst_idev(&rt->u.dst), IPSTATS_MIB_FRAGFAILS);
 687                 dst_release(&rt->u.dst);
 688                 return err;
 689         }
 690
 691 slow_path:
 692         left = skb->len - hlen;         /* Space per frame */
 693         ptr = hlen;                     /* Where to start from */
 694
 695         /*
 696          *      Fragment the datagram.
 697          */
 698
 699         *prevhdr = NEXTHDR_FRAGMENT;
 700
 701         /*
 702          *      Keep copying data until we run out.
 703          */
 704         while(left > 0) {
 705                 len = left;
 706                 /* IF: it doesn't fit, use 'mtu' - the data space left */
 707                 if (len > mtu)
 708                         len = mtu;
 709                 /* IF: we are not sending upto and including the packet end
 710                    then align the next start on an eight byte boundary */
 711                 if (len < left) {
 712                         len &= ~7;
 713                 }
 714                 /*
 715                  *      Allocate buffer.
 716                  */
 717
 718                 if ((frag = alloc_skb(len+hlen+sizeof(struct frag_hdr)+LL_RESERVED_SPACE(rt->u.dst.dev), GFP_ATOMIC)) == NULL) {
 719                         NETDEBUG(KERN_INFO "IPv6: frag: no memory for new fragment!\n");
 720                         IP6_INC_STATS(ip6_dst_idev(skb->dst),
 721                                       IPSTATS_MIB_FRAGFAILS);
 722                         err = -ENOMEM;
 723                         goto fail;
 724                 }
 725
 726                 /*
 727                  *      Set up data on packet
 728                  */
 729
 730                 ip6_copy_metadata(frag, skb);
 731                 skb_reserve(frag, LL_RESERVED_SPACE(rt->u.dst.dev));
 732                 skb_put(frag, len + hlen + sizeof(struct frag_hdr));
 733                 skb_reset_network_header(frag);
 734                 fh = (struct frag_hdr *)(skb_network_header(frag) + hlen);
 735                 frag->h.raw = frag->nh.raw + hlen + sizeof(struct frag_hdr);
 736
 737                 /*
 738                  *      Charge the memory for the fragment to any owner
 739                  *      it might possess
 740                  */
 741                 if (skb->sk)
 742                         skb_set_owner_w(frag, skb->sk);
 743
 744                 /*
 745                  *      Copy the packet header into the new buffer.
 746                  */
 747                 memcpy(skb_network_header(frag), skb->data, hlen);
 748
 749                 /*
 750                  *      Build fragment header.
 751                  */
 752                 fh->nexthdr = nexthdr;
 753                 fh->reserved = 0;
 754                 if (!frag_id) {
 755                         ipv6_select_ident(skb, fh);
 756                         frag_id = fh->identification;
 757                 } else
 758                         fh->identification = frag_id;
 759
 760                 /*
 761                  *      Copy a block of the IP datagram.
 762                  */
 763                 if (skb_copy_bits(skb, ptr, frag->h.raw, len))
 764                         BUG();
 765                 left -= len;
 766
 767                 fh->frag_off = htons(offset);
 768                 if (left > 0)
 769                         fh->frag_off |= htons(IP6_MF);
 770                 ipv6_hdr(frag)->payload_len = htons(frag->len -
 771                                                     sizeof(struct ipv6hdr));
 772
 773                 ptr += len;
 774                 offset += len;
 775
 776                 /*
 777                  *      Put this fragment into the sending queue.
 778                  */
 779                 err = output(frag);
 780                 if (err)
 781                         goto fail;
 782
 783                 IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_FRAGCREATES);
 784         }
 785         IP6_INC_STATS(ip6_dst_idev(skb->dst),
 786                       IPSTATS_MIB_FRAGOKS);
 787         kfree_skb(skb);
 788         return err;
 789
 790 fail:
 791         IP6_INC_STATS(ip6_dst_idev(skb->dst),
 792                       IPSTATS_MIB_FRAGFAILS);
 793         kfree_skb(skb);
 794         return err;
 795 }
 796
 797 static inline int ip6_rt_check(struct rt6key *rt_key,
 798                                struct in6_addr *fl_addr,
 799                                struct in6_addr *addr_cache)
 800 {
 801         return ((rt_key->plen != 128 || !ipv6_addr_equal(fl_addr, &rt_key->addr)) &&
 802                 (addr_cache == NULL || !ipv6_addr_equal(fl_addr, addr_cache)));
 803 }
 804
 805 static struct dst_entry *ip6_sk_dst_check(struct sock *sk,
 806                                           struct dst_entry *dst,
 807                                           struct flowi *fl)
 808 {
 809         struct ipv6_pinfo *np = inet6_sk(sk);
 810         struct rt6_info *rt = (struct rt6_info *)dst;
 811
 812         if (!dst)
 813                 goto out;
 814
 815         /* Yes, checking route validity in not connected
 816          * case is not very simple. Take into account,
 817          * that we do not support routing by source, TOS,
 818          * and MSG_DONTROUTE            --ANK (980726)
 819          *
 820          * 1. ip6_rt_check(): If route was host route,
 821          *    check that cached destination is current.
 822          *    If it is network route, we still may
 823          *    check its validity using saved pointer
 824          *    to the last used address: daddr_cache.
 825          *    We do not want to save whole address now,
 826          *    (because main consumer of this service
 827          *    is tcp, which has not this problem),
 828          *    so that the last trick works only on connected
 829          *    sockets.
 830          * 2. oif also should be the same.
 831          */
 832         if (ip6_rt_check(&rt->rt6i_dst, &fl->fl6_dst, np->daddr_cache) ||
 833 #ifdef CONFIG_IPV6_SUBTREES
 834             ip6_rt_check(&rt->rt6i_src, &fl->fl6_src, np->saddr_cache) ||
 835 #endif
 836             (fl->oif && fl->oif != dst->dev->ifindex)) {
 837                 dst_release(dst);
 838                 dst = NULL;
 839         }
 840
 841 out:
 842         return dst;
 843 }
 844
 845 static int ip6_dst_lookup_tail(struct sock *sk,
 846                                struct dst_entry **dst, struct flowi *fl)
 847 {
 848         int err;
 849
 850         if (*dst == NULL)
 851                 *dst = ip6_route_output(sk, fl);
 852
 853         if ((err = (*dst)->error))
 854                 goto out_err_release;
 855
 856         if (ipv6_addr_any(&fl->fl6_src)) {
 857                 err = ipv6_get_saddr(*dst, &fl->fl6_dst, &fl->fl6_src);
 858                 if (err)
 859                         goto out_err_release;
 860         }
 861
 862 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
 863                 /*
 864                  * Here if the dst entry we've looked up
 865                  * has a neighbour entry that is in the INCOMPLETE
 866                  * state and the src address from the flow is
 867                  * marked as OPTIMISTIC, we release the found
 868                  * dst entry and replace it instead with the
 869                  * dst entry of the nexthop router
 870                  */
 871                 if (!((*dst)->neighbour->nud_state & NUD_VALID)) {
 872                         struct inet6_ifaddr *ifp;
 873                         struct flowi fl_gw;
 874                         int redirect;
 875
 876                         ifp = ipv6_get_ifaddr(&fl->fl6_src, (*dst)->dev, 1);
 877
 878                         redirect = (ifp && ifp->flags & IFA_F_OPTIMISTIC);
 879                         if (ifp)
 880                                 in6_ifa_put(ifp);
 881
 882                         if (redirect) {
 883                                 /*
 884                                  * We need to get the dst entry for the
 885                                  * default router instead
 886                                  */
 887                                 dst_release(*dst);
 888                                 memcpy(&fl_gw, fl, sizeof(struct flowi));
 889                                 memset(&fl_gw.fl6_dst, 0, sizeof(struct in6_addr));
 890                                 *dst = ip6_route_output(sk, &fl_gw);
 891                                 if ((err = (*dst)->error))
 892                                         goto out_err_release;
 893                         }
 894                 }
 895 #endif
 896
 897         return 0;
 898
 899 out_err_release:
 900         dst_release(*dst);
 901         *dst = NULL;
 902         return err;
 903 }
 904
 905 /**
 906  *      ip6_dst_lookup - perform route lookup on flow
 907  *      @sk: socket which provides route info
 908  *      @dst: pointer to dst_entry * for result
 909  *      @fl: flow to lookup
 910  *
 911  *      This function performs a route lookup on the given flow.
 912  *
 913  *      It returns zero on success, or a standard errno code on error.
 914  */
 915 int ip6_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi *fl)
 916 {
 917         *dst = NULL;
 918         return ip6_dst_lookup_tail(sk, dst, fl);
 919 }
 920 EXPORT_SYMBOL_GPL(ip6_dst_lookup);
 921
 922 /**
 923  *      ip6_sk_dst_lookup - perform socket cached route lookup on flow
 924  *      @sk: socket which provides the dst cache and route info
 925  *      @dst: pointer to dst_entry * for result
 926  *      @fl: flow to lookup
 927  *
 928  *      This function performs a route lookup on the given flow with the
 929  *      possibility of using the cached route in the socket if it is valid.
 930  *      It will take the socket dst lock when operating on the dst cache.
 931  *      As a result, this function can only be used in process context.
 932  *
 933  *      It returns zero on success, or a standard errno code on error.
 934  */
 935 int ip6_sk_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi *fl)
 936 {
 937         *dst = NULL;
 938         if (sk) {
 939                 *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie);
 940                 *dst = ip6_sk_dst_check(sk, *dst, fl);
 941         }
 942
 943         return ip6_dst_lookup_tail(sk, dst, fl);
 944 }
 945 EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup);
 946
 947 static inline int ip6_ufo_append_data(struct sock *sk,
 948                         int getfrag(void *from, char *to, int offset, int len,
 949                         int odd, struct sk_buff *skb),
 950                         void *from, int length, int hh_len, int fragheaderlen,
 951                         int transhdrlen, int mtu,unsigned int flags)
 952
 953 {
 954         struct sk_buff *skb;
 955         int err;
 956
 957         /* There is support for UDP large send offload by network
 958          * device, so create one single skb packet containing complete
 959          * udp datagram
 960          */
 961         if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) {
 962                 skb = sock_alloc_send_skb(sk,
 963                         hh_len + fragheaderlen + transhdrlen + 20,
 964                         (flags & MSG_DONTWAIT), &err);
 965                 if (skb == NULL)
 966                         return -ENOMEM;
 967
 968                 /* reserve space for Hardware header */
 969                 skb_reserve(skb, hh_len);
 970
 971                 /* create space for UDP/IP header */
 972                 skb_put(skb,fragheaderlen + transhdrlen);
 973
 974                 /* initialize network header pointer */
 975                 skb_reset_network_header(skb);
 976
 977                 /* initialize protocol header pointer */
 978                 skb->h.raw = skb->nh.raw + fragheaderlen;
 979
 980                 skb->ip_summed = CHECKSUM_PARTIAL;
 981                 skb->csum = 0;
 982                 sk->sk_sndmsg_off = 0;
 983         }
 984
 985         err = skb_append_datato_frags(sk,skb, getfrag, from,
 986                                       (length - transhdrlen));
 987         if (!err) {
 988                 struct frag_hdr fhdr;
 989
 990                 /* specify the length of each IP datagram fragment*/
 991                 skb_shinfo(skb)->gso_size = mtu - fragheaderlen -
 992                                             sizeof(struct frag_hdr);
 993                 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
 994                 ipv6_select_ident(skb, &fhdr);
 995                 skb_shinfo(skb)->ip6_frag_id = fhdr.identification;
 996                 __skb_queue_tail(&sk->sk_write_queue, skb);
 997
 998                 return 0;
 999         }
1000         /* There is not enough support do UPD LSO,
1001          * so follow normal path
1002          */
1003         kfree_skb(skb);
1004
1005         return err;
1006 }
1007
1008 int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
1009         int offset, int len, int odd, struct sk_buff *skb),
1010         void *from, int length, int transhdrlen,
1011         int hlimit, int tclass, struct ipv6_txoptions *opt, struct flowi *fl,
1012         struct rt6_info *rt, unsigned int flags)
1013 {
1014         struct inet_sock *inet = inet_sk(sk);
1015         struct ipv6_pinfo *np = inet6_sk(sk);
1016         struct sk_buff *skb;
1017         unsigned int maxfraglen, fragheaderlen;
1018         int exthdrlen;
1019         int hh_len;
1020         int mtu;
1021         int copy;
1022         int err;
1023         int offset = 0;
1024         int csummode = CHECKSUM_NONE;
1025
1026         if (flags&MSG_PROBE)
1027                 return 0;
1028         if (skb_queue_empty(&sk->sk_write_queue)) {
1029                 /*
1030                  * setup for corking
1031                  */
1032                 if (opt) {
1033                         if (np->cork.opt == NULL) {
1034                                 np->cork.opt = kmalloc(opt->tot_len,
1035                                                        sk->sk_allocation);
1036                                 if (unlikely(np->cork.opt == NULL))
1037                                         return -ENOBUFS;
1038                         } else if (np->cork.opt->tot_len < opt->tot_len) {
1039                                 printk(KERN_DEBUG "ip6_append_data: invalid option length\n");
1040                                 return -EINVAL;
1041                         }
1042                         memcpy(np->cork.opt, opt, opt->tot_len);
1043                         inet->cork.flags |= IPCORK_OPT;
1044                         /* need source address above miyazawa*/
1045                 }
1046                 dst_hold(&rt->u.dst);
1047                 np->cork.rt = rt;
1048                 inet->cork.fl = *fl;
1049                 np->cork.hop_limit = hlimit;
1050                 np->cork.tclass = tclass;
1051                 mtu = dst_mtu(rt->u.dst.path);
1052                 if (np->frag_size < mtu) {
1053                         if (np->frag_size)
1054                                 mtu = np->frag_size;
1055                 }
1056                 inet->cork.fragsize = mtu;
1057                 if (dst_allfrag(rt->u.dst.path))
1058                         inet->cork.flags |= IPCORK_ALLFRAG;
1059                 inet->cork.length = 0;
1060                 sk->sk_sndmsg_page = NULL;
1061                 sk->sk_sndmsg_off = 0;
1062                 exthdrlen = rt->u.dst.header_len + (opt ? opt->opt_flen : 0);
1063                 length += exthdrlen;
1064                 transhdrlen += exthdrlen;
1065         } else {
1066                 rt = np->cork.rt;
1067                 fl = &inet->cork.fl;
1068                 if (inet->cork.flags & IPCORK_OPT)
1069                         opt = np->cork.opt;
1070                 transhdrlen = 0;
1071                 exthdrlen = 0;
1072                 mtu = inet->cork.fragsize;
1073         }
1074
1075         hh_len = LL_RESERVED_SPACE(rt->u.dst.dev);
1076
1077         fragheaderlen = sizeof(struct ipv6hdr) + rt->u.dst.nfheader_len + (opt ? opt->opt_nflen : 0);
1078         maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - sizeof(struct frag_hdr);
1079
1080         if (mtu <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN) {
1081                 if (inet->cork.length + length > sizeof(struct ipv6hdr) + IPV6_MAXPLEN - fragheaderlen) {
1082                         ipv6_local_error(sk, EMSGSIZE, fl, mtu-exthdrlen);
1083                         return -EMSGSIZE;
1084                 }
1085         }
1086
1087         /*
1088          * Let's try using as much space as possible.
1089          * Use MTU if total length of the message fits into the MTU.
1090          * Otherwise, we need to reserve fragment header and
1091          * fragment alignment (= 8-15 octects, in total).
1092          *
1093          * Note that we may need to "move" the data from the tail of
1094          * of the buffer to the new fragment when we split
1095          * the message.
1096          *
1097          * FIXME: It may be fragmented into multiple chunks
1098          *        at once if non-fragmentable extension headers
1099          *        are too large.
1100          * --yoshfuji
1101          */
1102
1103         inet->cork.length += length;
1104         if (((length > mtu) && (sk->sk_protocol == IPPROTO_UDP)) &&
1105             (rt->u.dst.dev->features & NETIF_F_UFO)) {
1106
1107                 err = ip6_ufo_append_data(sk, getfrag, from, length, hh_len,
1108                                           fragheaderlen, transhdrlen, mtu,
1109                                           flags);
1110                 if (err)
1111                         goto error;
1112                 return 0;
1113         }
1114
1115         if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL)
1116                 goto alloc_new_skb;
1117
1118         while (length > 0) {
1119                 /* Check if the remaining data fits into current packet. */
1120                 copy = (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len;
1121                 if (copy < length)
1122                         copy = maxfraglen - skb->len;
1123
1124                 if (copy <= 0) {
1125                         char *data;
1126                         unsigned int datalen;
1127                         unsigned int fraglen;
1128                         unsigned int fraggap;
1129                         unsigned int alloclen;
1130                         struct sk_buff *skb_prev;
1131 alloc_new_skb:
1132                         skb_prev = skb;
1133
1134                         /* There's no room in the current skb */
1135                         if (skb_prev)
1136                                 fraggap = skb_prev->len - maxfraglen;
1137                         else
1138                                 fraggap = 0;
1139
1140                         /*
1141                          * If remaining data exceeds the mtu,
1142                          * we know we need more fragment(s).
1143                          */
1144                         datalen = length + fraggap;
1145                         if (datalen > (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen)
1146                                 datalen = maxfraglen - fragheaderlen;
1147
1148                         fraglen = datalen + fragheaderlen;
1149                         if ((flags & MSG_MORE) &&
1150                             !(rt->u.dst.dev->features&NETIF_F_SG))
1151                                 alloclen = mtu;
1152                         else
1153                                 alloclen = datalen + fragheaderlen;
1154
1155                         /*
1156                          * The last fragment gets additional space at tail.
1157                          * Note: we overallocate on fragments with MSG_MODE
1158                          * because we have no idea if we're the last one.
1159                          */
1160                         if (datalen == length + fraggap)
1161                                 alloclen += rt->u.dst.trailer_len;
1162
1163                         /*
1164                          * We just reserve space for fragment header.
1165                          * Note: this may be overallocation if the message
1166                          * (without MSG_MORE) fits into the MTU.
1167                          */
1168                         alloclen += sizeof(struct frag_hdr);
1169
1170                         if (transhdrlen) {
1171                                 skb = sock_alloc_send_skb(sk,
1172                                                 alloclen + hh_len,
1173                                                 (flags & MSG_DONTWAIT), &err);
1174                         } else {
1175                                 skb = NULL;
1176                                 if (atomic_read(&sk->sk_wmem_alloc) <=
1177                                     2 * sk->sk_sndbuf)
1178                                         skb = sock_wmalloc(sk,
1179                                                            alloclen + hh_len, 1,
1180                                                            sk->sk_allocation);
1181                                 if (unlikely(skb == NULL))
1182                                         err = -ENOBUFS;
1183                         }
1184                         if (skb == NULL)
1185                                 goto error;
1186                         /*
1187                          *      Fill in the control structures
1188                          */
1189                         skb->ip_summed = csummode;
1190                         skb->csum = 0;
1191                         /* reserve for fragmentation */
1192                         skb_reserve(skb, hh_len+sizeof(struct frag_hdr));
1193
1194                         /*
1195                          *      Find where to start putting bytes
1196                          */
1197                         data = skb_put(skb, fraglen);
1198                         skb_set_network_header(skb, exthdrlen);
1199                         data += fragheaderlen;
1200                         skb->h.raw = skb->nh.raw + fragheaderlen;
1201
1202                         if (fraggap) {
1203                                 skb->csum = skb_copy_and_csum_bits(
1204                                         skb_prev, maxfraglen,
1205                                         data + transhdrlen, fraggap, 0);
1206                                 skb_prev->csum = csum_sub(skb_prev->csum,
1207                                                           skb->csum);
1208                                 data += fraggap;
1209                                 pskb_trim_unique(skb_prev, maxfraglen);
1210                         }
1211                         copy = datalen - transhdrlen - fraggap;
1212                         if (copy < 0) {
1213                                 err = -EINVAL;
1214                                 kfree_skb(skb);
1215                                 goto error;
1216                         } else if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) {
1217                                 err = -EFAULT;
1218                                 kfree_skb(skb);
1219                                 goto error;
1220                         }
1221
1222                         offset += copy;
1223                         length -= datalen - fraggap;
1224                         transhdrlen = 0;
1225                         exthdrlen = 0;
1226                         csummode = CHECKSUM_NONE;
1227
1228                         /*
1229                          * Put the packet on the pending queue
1230                          */
1231                         __skb_queue_tail(&sk->sk_write_queue, skb);
1232                         continue;
1233                 }
1234
1235                 if (copy > length)
1236                         copy = length;
1237
1238                 if (!(rt->u.dst.dev->features&NETIF_F_SG)) {
1239                         unsigned int off;
1240
1241                         off = skb->len;
1242                         if (getfrag(from, skb_put(skb, copy),
1243                                                 offset, copy, off, skb) < 0) {
1244                                 __skb_trim(skb, off);
1245                                 err = -EFAULT;
1246                                 goto error;
1247                         }
1248                 } else {
1249                         int i = skb_shinfo(skb)->nr_frags;
1250                         skb_frag_t *frag = &skb_shinfo(skb)->frags[i-1];
1251                         struct page *page = sk->sk_sndmsg_page;
1252                         int off = sk->sk_sndmsg_off;
1253                         unsigned int left;
1254
1255                         if (page && (left = PAGE_SIZE - off) > 0) {
1256                                 if (copy >= left)
1257                                         copy = left;
1258                                 if (page != frag->page) {
1259                                         if (i == MAX_SKB_FRAGS) {
1260                                                 err = -EMSGSIZE;
1261                                                 goto error;
1262                                         }
1263                                         get_page(page);
1264                                         skb_fill_page_desc(skb, i, page, sk->sk_sndmsg_off, 0);
1265                                         frag = &skb_shinfo(skb)->frags[i];
1266                                 }
1267                         } else if(i < MAX_SKB_FRAGS) {
1268                                 if (copy > PAGE_SIZE)
1269                                         copy = PAGE_SIZE;
1270                                 page = alloc_pages(sk->sk_allocation, 0);
1271                                 if (page == NULL) {
1272                                         err = -ENOMEM;
1273                                         goto error;
1274                                 }
1275                                 sk->sk_sndmsg_page = page;
1276                                 sk->sk_sndmsg_off = 0;
1277
1278                                 skb_fill_page_desc(skb, i, page, 0, 0);
1279                                 frag = &skb_shinfo(skb)->frags[i];
1280                                 skb->truesize += PAGE_SIZE;
1281                                 atomic_add(PAGE_SIZE, &sk->sk_wmem_alloc);
1282                         } else {
1283                                 err = -EMSGSIZE;
1284                                 goto error;
1285                         }
1286                         if (getfrag(from, page_address(frag->page)+frag->page_offset+frag->size, offset, copy, skb->len, skb) < 0) {
1287                                 err = -EFAULT;
1288                                 goto error;
1289                         }
1290                         sk->sk_sndmsg_off += copy;
1291                         frag->size += copy;
1292                         skb->len += copy;
1293                         skb->data_len += copy;
1294                 }
1295                 offset += copy;
1296                 length -= copy;
1297         }
1298         return 0;
1299 error:
1300         inet->cork.length -= length;
1301         IP6_INC_STATS(rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS);
1302         return err;
1303 }
1304
1305 int ip6_push_pending_frames(struct sock *sk)
1306 {
1307         struct sk_buff *skb, *tmp_skb;
1308         struct sk_buff **tail_skb;
1309         struct in6_addr final_dst_buf, *final_dst = &final_dst_buf;
1310         struct inet_sock *inet = inet_sk(sk);
1311         struct ipv6_pinfo *np = inet6_sk(sk);
1312         struct ipv6hdr *hdr;
1313         struct ipv6_txoptions *opt = np->cork.opt;
1314         struct rt6_info *rt = np->cork.rt;
1315         struct flowi *fl = &inet->cork.fl;
1316         unsigned char proto = fl->proto;
1317         int err = 0;
1318
1319         if ((skb = __skb_dequeue(&sk->sk_write_queue)) == NULL)
1320                 goto out;
1321         tail_skb = &(skb_shinfo(skb)->frag_list);
1322
1323         /* move skb->data to ip header from ext header */
1324         if (skb->data < skb_network_header(skb))
1325                 __skb_pull(skb, skb_network_offset(skb));
1326         while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) {
1327                 __skb_pull(tmp_skb, skb->h.raw - skb->nh.raw);
1328                 *tail_skb = tmp_skb;
1329                 tail_skb = &(tmp_skb->next);
1330                 skb->len += tmp_skb->len;
1331                 skb->data_len += tmp_skb->len;
1332                 skb->truesize += tmp_skb->truesize;
1333                 __sock_put(tmp_skb->sk);
1334                 tmp_skb->destructor = NULL;
1335                 tmp_skb->sk = NULL;
1336         }
1337
1338         ipv6_addr_copy(final_dst, &fl->fl6_dst);
1339         __skb_pull(skb, skb->h.raw - skb->nh.raw);
1340         if (opt && opt->opt_flen)
1341                 ipv6_push_frag_opts(skb, opt, &proto);
1342         if (opt && opt->opt_nflen)
1343                 ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst);
1344
1345         skb_push(skb, sizeof(struct ipv6hdr));
1346         skb_reset_network_header(skb);
1347         hdr = ipv6_hdr(skb);
1348
1349         *(__be32*)hdr = fl->fl6_flowlabel |
1350                      htonl(0x60000000 | ((int)np->cork.tclass << 20));
1351
1352         if (skb->len <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN)
1353                 hdr->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
1354         else
1355                 hdr->payload_len = 0;
1356         hdr->hop_limit = np->cork.hop_limit;
1357         hdr->nexthdr = proto;
1358         ipv6_addr_copy(&hdr->saddr, &fl->fl6_src);
1359         ipv6_addr_copy(&hdr->daddr, final_dst);
1360
1361         skb->priority = sk->sk_priority;
1362
1363         skb->dst = dst_clone(&rt->u.dst);
1364         IP6_INC_STATS(rt->rt6i_idev, IPSTATS_MIB_OUTREQUESTS);
1365         err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, skb->dst->dev, dst_output);
1366         if (err) {
1367                 if (err > 0)
1368                         err = np->recverr ? net_xmit_errno(err) : 0;
1369                 if (err)
1370                         goto error;
1371         }
1372
1373 out:
1374         inet->cork.flags &= ~IPCORK_OPT;
1375         kfree(np->cork.opt);
1376         np->cork.opt = NULL;
1377         if (np->cork.rt) {
1378                 dst_release(&np->cork.rt->u.dst);
1379                 np->cork.rt = NULL;
1380                 inet->cork.flags &= ~IPCORK_ALLFRAG;
1381         }
1382         memset(&inet->cork.fl, 0, sizeof(inet->cork.fl));
1383         return err;
1384 error:
1385         goto out;
1386 }
1387
1388 void ip6_flush_pending_frames(struct sock *sk)
1389 {
1390         struct inet_sock *inet = inet_sk(sk);
1391         struct ipv6_pinfo *np = inet6_sk(sk);
1392         struct sk_buff *skb;
1393
1394         while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) {
1395                 IP6_INC_STATS(ip6_dst_idev(skb->dst),
1396                               IPSTATS_MIB_OUTDISCARDS);
1397                 kfree_skb(skb);
1398         }
1399
1400         inet->cork.flags &= ~IPCORK_OPT;
1401
1402         kfree(np->cork.opt);
1403         np->cork.opt = NULL;
1404         if (np->cork.rt) {
1405                 dst_release(&np->cork.rt->u.dst);
1406                 np->cork.rt = NULL;
1407                 inet->cork.flags &= ~IPCORK_ALLFRAG;
1408         }
1409         memset(&inet->cork.fl, 0, sizeof(inet->cork.fl));
1410 }