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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, 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(&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         skb_push(skb, sizeof(struct ipv6hdr));
 195         skb_reset_network_header(skb);
 196         hdr = skb->nh.ipv6h;
 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         hdr = (struct ipv6hdr *) skb_put(skb, sizeof(struct ipv6hdr));
 267         skb->nh.ipv6h = hdr;
 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 = skb->nh.ipv6h;
 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 = skb->nh.ipv6h;
 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 = skb->nh.ipv6h;
 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 #ifdef CONFIG_NETFILTER
 508         /* Connection association is same as pre-frag packet */
 509         nf_conntrack_put(to->nfct);
 510         to->nfct = from->nfct;
 511         nf_conntrack_get(to->nfct);
 512         to->nfctinfo = from->nfctinfo;
 513 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
 514         nf_conntrack_put_reasm(to->nfct_reasm);
 515         to->nfct_reasm = from->nfct_reasm;
 516         nf_conntrack_get_reasm(to->nfct_reasm);
 517 #endif
 518 #ifdef CONFIG_BRIDGE_NETFILTER
 519         nf_bridge_put(to->nf_bridge);
 520         to->nf_bridge = from->nf_bridge;
 521         nf_bridge_get(to->nf_bridge);
 522 #endif
 523 #endif
 524         skb_copy_secmark(to, from);
 525 }
 526
 527 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr)
 528 {
 529         u16 offset = sizeof(struct ipv6hdr);
 530         struct ipv6_opt_hdr *exthdr = (struct ipv6_opt_hdr*)(skb->nh.ipv6h + 1);
 531         unsigned int packet_len = skb->tail - skb_network_header(skb);
 532         int found_rhdr = 0;
 533         *nexthdr = &skb->nh.ipv6h->nexthdr;
 534
 535         while (offset + 1 <= packet_len) {
 536
 537                 switch (**nexthdr) {
 538
 539                 case NEXTHDR_HOP:
 540                         break;
 541                 case NEXTHDR_ROUTING:
 542                         found_rhdr = 1;
 543                         break;
 544                 case NEXTHDR_DEST:
 545 #ifdef CONFIG_IPV6_MIP6
 546                         if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
 547                                 break;
 548 #endif
 549                         if (found_rhdr)
 550                                 return offset;
 551                         break;
 552                 default :
 553                         return offset;
 554                 }
 555
 556                 offset += ipv6_optlen(exthdr);
 557                 *nexthdr = &exthdr->nexthdr;
 558                 exthdr = (struct ipv6_opt_hdr *)(skb_network_header(skb) +
 559                                                  offset);
 560         }
 561
 562         return offset;
 563 }
 564 EXPORT_SYMBOL_GPL(ip6_find_1stfragopt);
 565
 566 static int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *))
 567 {
 568         struct net_device *dev;
 569         struct sk_buff *frag;
 570         struct rt6_info *rt = (struct rt6_info*)skb->dst;
 571         struct ipv6_pinfo *np = skb->sk ? inet6_sk(skb->sk) : NULL;
 572         struct ipv6hdr *tmp_hdr;
 573         struct frag_hdr *fh;
 574         unsigned int mtu, hlen, left, len;
 575         __be32 frag_id = 0;
 576         int ptr, offset = 0, err=0;
 577         u8 *prevhdr, nexthdr = 0;
 578
 579         dev = rt->u.dst.dev;
 580         hlen = ip6_find_1stfragopt(skb, &prevhdr);
 581         nexthdr = *prevhdr;
 582
 583         mtu = dst_mtu(&rt->u.dst);
 584         if (np && np->frag_size < mtu) {
 585                 if (np->frag_size)
 586                         mtu = np->frag_size;
 587         }
 588         mtu -= hlen + sizeof(struct frag_hdr);
 589
 590         if (skb_shinfo(skb)->frag_list) {
 591                 int first_len = skb_pagelen(skb);
 592
 593                 if (first_len - hlen > mtu ||
 594                     ((first_len - hlen) & 7) ||
 595                     skb_cloned(skb))
 596                         goto slow_path;
 597
 598                 for (frag = skb_shinfo(skb)->frag_list; frag; frag = frag->next) {
 599                         /* Correct geometry. */
 600                         if (frag->len > mtu ||
 601                             ((frag->len & 7) && frag->next) ||
 602                             skb_headroom(frag) < hlen)
 603                             goto slow_path;
 604
 605                         /* Partially cloned skb? */
 606                         if (skb_shared(frag))
 607                                 goto slow_path;
 608
 609                         BUG_ON(frag->sk);
 610                         if (skb->sk) {
 611                                 sock_hold(skb->sk);
 612                                 frag->sk = skb->sk;
 613                                 frag->destructor = sock_wfree;
 614                                 skb->truesize -= frag->truesize;
 615                         }
 616                 }
 617
 618                 err = 0;
 619                 offset = 0;
 620                 frag = skb_shinfo(skb)->frag_list;
 621                 skb_shinfo(skb)->frag_list = NULL;
 622                 /* BUILD HEADER */
 623
 624                 *prevhdr = NEXTHDR_FRAGMENT;
 625                 tmp_hdr = kmemdup(skb_network_header(skb), hlen, GFP_ATOMIC);
 626                 if (!tmp_hdr) {
 627                         IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_FRAGFAILS);
 628                         return -ENOMEM;
 629                 }
 630
 631                 __skb_pull(skb, hlen);
 632                 fh = (struct frag_hdr*)__skb_push(skb, sizeof(struct frag_hdr));
 633                 __skb_push(skb, hlen);
 634                 skb_reset_network_header(skb);
 635                 memcpy(skb_network_header(skb), tmp_hdr, hlen);
 636
 637                 ipv6_select_ident(skb, fh);
 638                 fh->nexthdr = nexthdr;
 639                 fh->reserved = 0;
 640                 fh->frag_off = htons(IP6_MF);
 641                 frag_id = fh->identification;
 642
 643                 first_len = skb_pagelen(skb);
 644                 skb->data_len = first_len - skb_headlen(skb);
 645                 skb->len = first_len;
 646                 skb->nh.ipv6h->payload_len = htons(first_len - sizeof(struct ipv6hdr));
 647
 648                 dst_hold(&rt->u.dst);
 649
 650                 for (;;) {
 651                         /* Prepare header of the next frame,
 652                          * before previous one went down. */
 653                         if (frag) {
 654                                 frag->ip_summed = CHECKSUM_NONE;
 655                                 frag->h.raw = frag->data;
 656                                 fh = (struct frag_hdr*)__skb_push(frag, sizeof(struct frag_hdr));
 657                                 __skb_push(frag, hlen);
 658                                 skb_reset_network_header(frag);
 659                                 memcpy(skb_network_header(frag), tmp_hdr,
 660                                        hlen);
 661                                 offset += skb->len - hlen - sizeof(struct frag_hdr);
 662                                 fh->nexthdr = nexthdr;
 663                                 fh->reserved = 0;
 664                                 fh->frag_off = htons(offset);
 665                                 if (frag->next != NULL)
 666                                         fh->frag_off |= htons(IP6_MF);
 667                                 fh->identification = frag_id;
 668                                 frag->nh.ipv6h->payload_len = htons(frag->len - sizeof(struct ipv6hdr));
 669                                 ip6_copy_metadata(frag, skb);
 670                         }
 671
 672                         err = output(skb);
 673                         if(!err)
 674                                 IP6_INC_STATS(ip6_dst_idev(&rt->u.dst), IPSTATS_MIB_FRAGCREATES);
 675
 676                         if (err || !frag)
 677                                 break;
 678
 679                         skb = frag;
 680                         frag = skb->next;
 681                         skb->next = NULL;
 682                 }
 683
 684                 kfree(tmp_hdr);
 685
 686                 if (err == 0) {
 687                         IP6_INC_STATS(ip6_dst_idev(&rt->u.dst), IPSTATS_MIB_FRAGOKS);
 688                         dst_release(&rt->u.dst);
 689                         return 0;
 690                 }
 691
 692                 while (frag) {
 693                         skb = frag->next;
 694                         kfree_skb(frag);
 695                         frag = skb;
 696                 }
 697
 698                 IP6_INC_STATS(ip6_dst_idev(&rt->u.dst), IPSTATS_MIB_FRAGFAILS);
 699                 dst_release(&rt->u.dst);
 700                 return err;
 701         }
 702
 703 slow_path:
 704         left = skb->len - hlen;         /* Space per frame */
 705         ptr = hlen;                     /* Where to start from */
 706
 707         /*
 708          *      Fragment the datagram.
 709          */
 710
 711         *prevhdr = NEXTHDR_FRAGMENT;
 712
 713         /*
 714          *      Keep copying data until we run out.
 715          */
 716         while(left > 0) {
 717                 len = left;
 718                 /* IF: it doesn't fit, use 'mtu' - the data space left */
 719                 if (len > mtu)
 720                         len = mtu;
 721                 /* IF: we are not sending upto and including the packet end
 722                    then align the next start on an eight byte boundary */
 723                 if (len < left) {
 724                         len &= ~7;
 725                 }
 726                 /*
 727                  *      Allocate buffer.
 728                  */
 729
 730                 if ((frag = alloc_skb(len+hlen+sizeof(struct frag_hdr)+LL_RESERVED_SPACE(rt->u.dst.dev), GFP_ATOMIC)) == NULL) {
 731                         NETDEBUG(KERN_INFO "IPv6: frag: no memory for new fragment!\n");
 732                         IP6_INC_STATS(ip6_dst_idev(skb->dst),
 733                                       IPSTATS_MIB_FRAGFAILS);
 734                         err = -ENOMEM;
 735                         goto fail;
 736                 }
 737
 738                 /*
 739                  *      Set up data on packet
 740                  */
 741
 742                 ip6_copy_metadata(frag, skb);
 743                 skb_reserve(frag, LL_RESERVED_SPACE(rt->u.dst.dev));
 744                 skb_put(frag, len + hlen + sizeof(struct frag_hdr));
 745                 skb_reset_network_header(frag);
 746                 fh = (struct frag_hdr*)(frag->data + hlen);
 747                 frag->h.raw = frag->data + hlen + sizeof(struct frag_hdr);
 748
 749                 /*
 750                  *      Charge the memory for the fragment to any owner
 751                  *      it might possess
 752                  */
 753                 if (skb->sk)
 754                         skb_set_owner_w(frag, skb->sk);
 755
 756                 /*
 757                  *      Copy the packet header into the new buffer.
 758                  */
 759                 memcpy(skb_network_header(frag), skb->data, hlen);
 760
 761                 /*
 762                  *      Build fragment header.
 763                  */
 764                 fh->nexthdr = nexthdr;
 765                 fh->reserved = 0;
 766                 if (!frag_id) {
 767                         ipv6_select_ident(skb, fh);
 768                         frag_id = fh->identification;
 769                 } else
 770                         fh->identification = frag_id;
 771
 772                 /*
 773                  *      Copy a block of the IP datagram.
 774                  */
 775                 if (skb_copy_bits(skb, ptr, frag->h.raw, len))
 776                         BUG();
 777                 left -= len;
 778
 779                 fh->frag_off = htons(offset);
 780                 if (left > 0)
 781                         fh->frag_off |= htons(IP6_MF);
 782                 frag->nh.ipv6h->payload_len = htons(frag->len - sizeof(struct ipv6hdr));
 783
 784                 ptr += len;
 785                 offset += len;
 786
 787                 /*
 788                  *      Put this fragment into the sending queue.
 789                  */
 790                 err = output(frag);
 791                 if (err)
 792                         goto fail;
 793
 794                 IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_FRAGCREATES);
 795         }
 796         IP6_INC_STATS(ip6_dst_idev(skb->dst),
 797                       IPSTATS_MIB_FRAGOKS);
 798         kfree_skb(skb);
 799         return err;
 800
 801 fail:
 802         IP6_INC_STATS(ip6_dst_idev(skb->dst),
 803                       IPSTATS_MIB_FRAGFAILS);
 804         kfree_skb(skb);
 805         return err;
 806 }
 807
 808 static inline int ip6_rt_check(struct rt6key *rt_key,
 809                                struct in6_addr *fl_addr,
 810                                struct in6_addr *addr_cache)
 811 {
 812         return ((rt_key->plen != 128 || !ipv6_addr_equal(fl_addr, &rt_key->addr)) &&
 813                 (addr_cache == NULL || !ipv6_addr_equal(fl_addr, addr_cache)));
 814 }
 815
 816 static struct dst_entry *ip6_sk_dst_check(struct sock *sk,
 817                                           struct dst_entry *dst,
 818                                           struct flowi *fl)
 819 {
 820         struct ipv6_pinfo *np = inet6_sk(sk);
 821         struct rt6_info *rt = (struct rt6_info *)dst;
 822
 823         if (!dst)
 824                 goto out;
 825
 826         /* Yes, checking route validity in not connected
 827          * case is not very simple. Take into account,
 828          * that we do not support routing by source, TOS,
 829          * and MSG_DONTROUTE            --ANK (980726)
 830          *
 831          * 1. ip6_rt_check(): If route was host route,
 832          *    check that cached destination is current.
 833          *    If it is network route, we still may
 834          *    check its validity using saved pointer
 835          *    to the last used address: daddr_cache.
 836          *    We do not want to save whole address now,
 837          *    (because main consumer of this service
 838          *    is tcp, which has not this problem),
 839          *    so that the last trick works only on connected
 840          *    sockets.
 841          * 2. oif also should be the same.
 842          */
 843         if (ip6_rt_check(&rt->rt6i_dst, &fl->fl6_dst, np->daddr_cache) ||
 844 #ifdef CONFIG_IPV6_SUBTREES
 845             ip6_rt_check(&rt->rt6i_src, &fl->fl6_src, np->saddr_cache) ||
 846 #endif
 847             (fl->oif && fl->oif != dst->dev->ifindex)) {
 848                 dst_release(dst);
 849                 dst = NULL;
 850         }
 851
 852 out:
 853         return dst;
 854 }
 855
 856 static int ip6_dst_lookup_tail(struct sock *sk,
 857                                struct dst_entry **dst, struct flowi *fl)
 858 {
 859         int err;
 860
 861         if (*dst == NULL)
 862                 *dst = ip6_route_output(sk, fl);
 863
 864         if ((err = (*dst)->error))
 865                 goto out_err_release;
 866
 867         if (ipv6_addr_any(&fl->fl6_src)) {
 868                 err = ipv6_get_saddr(*dst, &fl->fl6_dst, &fl->fl6_src);
 869                 if (err)
 870                         goto out_err_release;
 871         }
 872
 873 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
 874                 /*
 875                  * Here if the dst entry we've looked up
 876                  * has a neighbour entry that is in the INCOMPLETE
 877                  * state and the src address from the flow is
 878                  * marked as OPTIMISTIC, we release the found
 879                  * dst entry and replace it instead with the
 880                  * dst entry of the nexthop router
 881                  */
 882                 if (!((*dst)->neighbour->nud_state & NUD_VALID)) {
 883                         struct inet6_ifaddr *ifp;
 884                         struct flowi fl_gw;
 885                         int redirect;
 886
 887                         ifp = ipv6_get_ifaddr(&fl->fl6_src, (*dst)->dev, 1);
 888
 889                         redirect = (ifp && ifp->flags & IFA_F_OPTIMISTIC);
 890                         if (ifp)
 891                                 in6_ifa_put(ifp);
 892
 893                         if (redirect) {
 894                                 /*
 895                                  * We need to get the dst entry for the
 896                                  * default router instead
 897                                  */
 898                                 dst_release(*dst);
 899                                 memcpy(&fl_gw, fl, sizeof(struct flowi));
 900                                 memset(&fl_gw.fl6_dst, 0, sizeof(struct in6_addr));
 901                                 *dst = ip6_route_output(sk, &fl_gw);
 902                                 if ((err = (*dst)->error))
 903                                         goto out_err_release;
 904                         }
 905                 }
 906 #endif
 907
 908         return 0;
 909
 910 out_err_release:
 911         dst_release(*dst);
 912         *dst = NULL;
 913         return err;
 914 }
 915
 916 /**
 917  *      ip6_dst_lookup - perform route lookup on flow
 918  *      @sk: socket which provides route info
 919  *      @dst: pointer to dst_entry * for result
 920  *      @fl: flow to lookup
 921  *
 922  *      This function performs a route lookup on the given flow.
 923  *
 924  *      It returns zero on success, or a standard errno code on error.
 925  */
 926 int ip6_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi *fl)
 927 {
 928         *dst = NULL;
 929         return ip6_dst_lookup_tail(sk, dst, fl);
 930 }
 931 EXPORT_SYMBOL_GPL(ip6_dst_lookup);
 932
 933 /**
 934  *      ip6_sk_dst_lookup - perform socket cached route lookup on flow
 935  *      @sk: socket which provides the dst cache and route info
 936  *      @dst: pointer to dst_entry * for result
 937  *      @fl: flow to lookup
 938  *
 939  *      This function performs a route lookup on the given flow with the
 940  *      possibility of using the cached route in the socket if it is valid.
 941  *      It will take the socket dst lock when operating on the dst cache.
 942  *      As a result, this function can only be used in process context.
 943  *
 944  *      It returns zero on success, or a standard errno code on error.
 945  */
 946 int ip6_sk_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi *fl)
 947 {
 948         *dst = NULL;
 949         if (sk) {
 950                 *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie);
 951                 *dst = ip6_sk_dst_check(sk, *dst, fl);
 952         }
 953
 954         return ip6_dst_lookup_tail(sk, dst, fl);
 955 }
 956 EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup);
 957
 958 static inline int ip6_ufo_append_data(struct sock *sk,
 959                         int getfrag(void *from, char *to, int offset, int len,
 960                         int odd, struct sk_buff *skb),
 961                         void *from, int length, int hh_len, int fragheaderlen,
 962                         int transhdrlen, int mtu,unsigned int flags)
 963
 964 {
 965         struct sk_buff *skb;
 966         int err;
 967
 968         /* There is support for UDP large send offload by network
 969          * device, so create one single skb packet containing complete
 970          * udp datagram
 971          */
 972         if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) {
 973                 skb = sock_alloc_send_skb(sk,
 974                         hh_len + fragheaderlen + transhdrlen + 20,
 975                         (flags & MSG_DONTWAIT), &err);
 976                 if (skb == NULL)
 977                         return -ENOMEM;
 978
 979                 /* reserve space for Hardware header */
 980                 skb_reserve(skb, hh_len);
 981
 982                 /* create space for UDP/IP header */
 983                 skb_put(skb,fragheaderlen + transhdrlen);
 984
 985                 /* initialize network header pointer */
 986                 skb_reset_network_header(skb);
 987
 988                 /* initialize protocol header pointer */
 989                 skb->h.raw = skb->data + fragheaderlen;
 990
 991                 skb->ip_summed = CHECKSUM_PARTIAL;
 992                 skb->csum = 0;
 993                 sk->sk_sndmsg_off = 0;
 994         }
 995
 996         err = skb_append_datato_frags(sk,skb, getfrag, from,
 997                                       (length - transhdrlen));
 998         if (!err) {
 999                 struct frag_hdr fhdr;
1000
1001                 /* specify the length of each IP datagram fragment*/
1002                 skb_shinfo(skb)->gso_size = mtu - fragheaderlen -
1003                                             sizeof(struct frag_hdr);
1004                 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
1005                 ipv6_select_ident(skb, &fhdr);
1006                 skb_shinfo(skb)->ip6_frag_id = fhdr.identification;
1007                 __skb_queue_tail(&sk->sk_write_queue, skb);
1008
1009                 return 0;
1010         }
1011         /* There is not enough support do UPD LSO,
1012          * so follow normal path
1013          */
1014         kfree_skb(skb);
1015
1016         return err;
1017 }
1018
1019 int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
1020         int offset, int len, int odd, struct sk_buff *skb),
1021         void *from, int length, int transhdrlen,
1022         int hlimit, int tclass, struct ipv6_txoptions *opt, struct flowi *fl,
1023         struct rt6_info *rt, unsigned int flags)
1024 {
1025         struct inet_sock *inet = inet_sk(sk);
1026         struct ipv6_pinfo *np = inet6_sk(sk);
1027         struct sk_buff *skb;
1028         unsigned int maxfraglen, fragheaderlen;
1029         int exthdrlen;
1030         int hh_len;
1031         int mtu;
1032         int copy;
1033         int err;
1034         int offset = 0;
1035         int csummode = CHECKSUM_NONE;
1036
1037         if (flags&MSG_PROBE)
1038                 return 0;
1039         if (skb_queue_empty(&sk->sk_write_queue)) {
1040                 /*
1041                  * setup for corking
1042                  */
1043                 if (opt) {
1044                         if (np->cork.opt == NULL) {
1045                                 np->cork.opt = kmalloc(opt->tot_len,
1046                                                        sk->sk_allocation);
1047                                 if (unlikely(np->cork.opt == NULL))
1048                                         return -ENOBUFS;
1049                         } else if (np->cork.opt->tot_len < opt->tot_len) {
1050                                 printk(KERN_DEBUG "ip6_append_data: invalid option length\n");
1051                                 return -EINVAL;
1052                         }
1053                         memcpy(np->cork.opt, opt, opt->tot_len);
1054                         inet->cork.flags |= IPCORK_OPT;
1055                         /* need source address above miyazawa*/
1056                 }
1057                 dst_hold(&rt->u.dst);
1058                 np->cork.rt = rt;
1059                 inet->cork.fl = *fl;
1060                 np->cork.hop_limit = hlimit;
1061                 np->cork.tclass = tclass;
1062                 mtu = dst_mtu(rt->u.dst.path);
1063                 if (np->frag_size < mtu) {
1064                         if (np->frag_size)
1065                                 mtu = np->frag_size;
1066                 }
1067                 inet->cork.fragsize = mtu;
1068                 if (dst_allfrag(rt->u.dst.path))
1069                         inet->cork.flags |= IPCORK_ALLFRAG;
1070                 inet->cork.length = 0;
1071                 sk->sk_sndmsg_page = NULL;
1072                 sk->sk_sndmsg_off = 0;
1073                 exthdrlen = rt->u.dst.header_len + (opt ? opt->opt_flen : 0);
1074                 length += exthdrlen;
1075                 transhdrlen += exthdrlen;
1076         } else {
1077                 rt = np->cork.rt;
1078                 fl = &inet->cork.fl;
1079                 if (inet->cork.flags & IPCORK_OPT)
1080                         opt = np->cork.opt;
1081                 transhdrlen = 0;
1082                 exthdrlen = 0;
1083                 mtu = inet->cork.fragsize;
1084         }
1085
1086         hh_len = LL_RESERVED_SPACE(rt->u.dst.dev);
1087
1088         fragheaderlen = sizeof(struct ipv6hdr) + rt->u.dst.nfheader_len + (opt ? opt->opt_nflen : 0);
1089         maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - sizeof(struct frag_hdr);
1090
1091         if (mtu <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN) {
1092                 if (inet->cork.length + length > sizeof(struct ipv6hdr) + IPV6_MAXPLEN - fragheaderlen) {
1093                         ipv6_local_error(sk, EMSGSIZE, fl, mtu-exthdrlen);
1094                         return -EMSGSIZE;
1095                 }
1096         }
1097
1098         /*
1099          * Let's try using as much space as possible.
1100          * Use MTU if total length of the message fits into the MTU.
1101          * Otherwise, we need to reserve fragment header and
1102          * fragment alignment (= 8-15 octects, in total).
1103          *
1104          * Note that we may need to "move" the data from the tail of
1105          * of the buffer to the new fragment when we split
1106          * the message.
1107          *
1108          * FIXME: It may be fragmented into multiple chunks
1109          *        at once if non-fragmentable extension headers
1110          *        are too large.
1111          * --yoshfuji
1112          */
1113
1114         inet->cork.length += length;
1115         if (((length > mtu) && (sk->sk_protocol == IPPROTO_UDP)) &&
1116             (rt->u.dst.dev->features & NETIF_F_UFO)) {
1117
1118                 err = ip6_ufo_append_data(sk, getfrag, from, length, hh_len,
1119                                           fragheaderlen, transhdrlen, mtu,
1120                                           flags);
1121                 if (err)
1122                         goto error;
1123                 return 0;
1124         }
1125
1126         if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL)
1127                 goto alloc_new_skb;
1128
1129         while (length > 0) {
1130                 /* Check if the remaining data fits into current packet. */
1131                 copy = (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len;
1132                 if (copy < length)
1133                         copy = maxfraglen - skb->len;
1134
1135                 if (copy <= 0) {
1136                         char *data;
1137                         unsigned int datalen;
1138                         unsigned int fraglen;
1139                         unsigned int fraggap;
1140                         unsigned int alloclen;
1141                         struct sk_buff *skb_prev;
1142 alloc_new_skb:
1143                         skb_prev = skb;
1144
1145                         /* There's no room in the current skb */
1146                         if (skb_prev)
1147                                 fraggap = skb_prev->len - maxfraglen;
1148                         else
1149                                 fraggap = 0;
1150
1151                         /*
1152                          * If remaining data exceeds the mtu,
1153                          * we know we need more fragment(s).
1154                          */
1155                         datalen = length + fraggap;
1156                         if (datalen > (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen)
1157                                 datalen = maxfraglen - fragheaderlen;
1158
1159                         fraglen = datalen + fragheaderlen;
1160                         if ((flags & MSG_MORE) &&
1161                             !(rt->u.dst.dev->features&NETIF_F_SG))
1162                                 alloclen = mtu;
1163                         else
1164                                 alloclen = datalen + fragheaderlen;
1165
1166                         /*
1167                          * The last fragment gets additional space at tail.
1168                          * Note: we overallocate on fragments with MSG_MODE
1169                          * because we have no idea if we're the last one.
1170                          */
1171                         if (datalen == length + fraggap)
1172                                 alloclen += rt->u.dst.trailer_len;
1173
1174                         /*
1175                          * We just reserve space for fragment header.
1176                          * Note: this may be overallocation if the message
1177                          * (without MSG_MORE) fits into the MTU.
1178                          */
1179                         alloclen += sizeof(struct frag_hdr);
1180
1181                         if (transhdrlen) {
1182                                 skb = sock_alloc_send_skb(sk,
1183                                                 alloclen + hh_len,
1184                                                 (flags & MSG_DONTWAIT), &err);
1185                         } else {
1186                                 skb = NULL;
1187                                 if (atomic_read(&sk->sk_wmem_alloc) <=
1188                                     2 * sk->sk_sndbuf)
1189                                         skb = sock_wmalloc(sk,
1190                                                            alloclen + hh_len, 1,
1191                                                            sk->sk_allocation);
1192                                 if (unlikely(skb == NULL))
1193                                         err = -ENOBUFS;
1194                         }
1195                         if (skb == NULL)
1196                                 goto error;
1197                         /*
1198                          *      Fill in the control structures
1199                          */
1200                         skb->ip_summed = csummode;
1201                         skb->csum = 0;
1202                         /* reserve for fragmentation */
1203                         skb_reserve(skb, hh_len+sizeof(struct frag_hdr));
1204
1205                         /*
1206                          *      Find where to start putting bytes
1207                          */
1208                         data = skb_put(skb, fraglen);
1209                         skb_set_network_header(skb, exthdrlen);
1210                         data += fragheaderlen;
1211                         skb->h.raw = skb->nh.raw + fragheaderlen;
1212
1213                         if (fraggap) {
1214                                 skb->csum = skb_copy_and_csum_bits(
1215                                         skb_prev, maxfraglen,
1216                                         data + transhdrlen, fraggap, 0);
1217                                 skb_prev->csum = csum_sub(skb_prev->csum,
1218                                                           skb->csum);
1219                                 data += fraggap;
1220                                 pskb_trim_unique(skb_prev, maxfraglen);
1221                         }
1222                         copy = datalen - transhdrlen - fraggap;
1223                         if (copy < 0) {
1224                                 err = -EINVAL;
1225                                 kfree_skb(skb);
1226                                 goto error;
1227                         } else if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) {
1228                                 err = -EFAULT;
1229                                 kfree_skb(skb);
1230                                 goto error;
1231                         }
1232
1233                         offset += copy;
1234                         length -= datalen - fraggap;
1235                         transhdrlen = 0;
1236                         exthdrlen = 0;
1237                         csummode = CHECKSUM_NONE;
1238
1239                         /*
1240                          * Put the packet on the pending queue
1241                          */
1242                         __skb_queue_tail(&sk->sk_write_queue, skb);
1243                         continue;
1244                 }
1245
1246                 if (copy > length)
1247                         copy = length;
1248
1249                 if (!(rt->u.dst.dev->features&NETIF_F_SG)) {
1250                         unsigned int off;
1251
1252                         off = skb->len;
1253                         if (getfrag(from, skb_put(skb, copy),
1254                                                 offset, copy, off, skb) < 0) {
1255                                 __skb_trim(skb, off);
1256                                 err = -EFAULT;
1257                                 goto error;
1258                         }
1259                 } else {
1260                         int i = skb_shinfo(skb)->nr_frags;
1261                         skb_frag_t *frag = &skb_shinfo(skb)->frags[i-1];
1262                         struct page *page = sk->sk_sndmsg_page;
1263                         int off = sk->sk_sndmsg_off;
1264                         unsigned int left;
1265
1266                         if (page && (left = PAGE_SIZE - off) > 0) {
1267                                 if (copy >= left)
1268                                         copy = left;
1269                                 if (page != frag->page) {
1270                                         if (i == MAX_SKB_FRAGS) {
1271                                                 err = -EMSGSIZE;
1272                                                 goto error;
1273                                         }
1274                                         get_page(page);
1275                                         skb_fill_page_desc(skb, i, page, sk->sk_sndmsg_off, 0);
1276                                         frag = &skb_shinfo(skb)->frags[i];
1277                                 }
1278                         } else if(i < MAX_SKB_FRAGS) {
1279                                 if (copy > PAGE_SIZE)
1280                                         copy = PAGE_SIZE;
1281                                 page = alloc_pages(sk->sk_allocation, 0);
1282                                 if (page == NULL) {
1283                                         err = -ENOMEM;
1284                                         goto error;
1285                                 }
1286                                 sk->sk_sndmsg_page = page;
1287                                 sk->sk_sndmsg_off = 0;
1288
1289                                 skb_fill_page_desc(skb, i, page, 0, 0);
1290                                 frag = &skb_shinfo(skb)->frags[i];
1291                                 skb->truesize += PAGE_SIZE;
1292                                 atomic_add(PAGE_SIZE, &sk->sk_wmem_alloc);
1293                         } else {
1294                                 err = -EMSGSIZE;
1295                                 goto error;
1296                         }
1297                         if (getfrag(from, page_address(frag->page)+frag->page_offset+frag->size, offset, copy, skb->len, skb) < 0) {
1298                                 err = -EFAULT;
1299                                 goto error;
1300                         }
1301                         sk->sk_sndmsg_off += copy;
1302                         frag->size += copy;
1303                         skb->len += copy;
1304                         skb->data_len += copy;
1305                 }
1306                 offset += copy;
1307                 length -= copy;
1308         }
1309         return 0;
1310 error:
1311         inet->cork.length -= length;
1312         IP6_INC_STATS(rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS);
1313         return err;
1314 }
1315
1316 int ip6_push_pending_frames(struct sock *sk)
1317 {
1318         struct sk_buff *skb, *tmp_skb;
1319         struct sk_buff **tail_skb;
1320         struct in6_addr final_dst_buf, *final_dst = &final_dst_buf;
1321         struct inet_sock *inet = inet_sk(sk);
1322         struct ipv6_pinfo *np = inet6_sk(sk);
1323         struct ipv6hdr *hdr;
1324         struct ipv6_txoptions *opt = np->cork.opt;
1325         struct rt6_info *rt = np->cork.rt;
1326         struct flowi *fl = &inet->cork.fl;
1327         unsigned char proto = fl->proto;
1328         int err = 0;
1329
1330         if ((skb = __skb_dequeue(&sk->sk_write_queue)) == NULL)
1331                 goto out;
1332         tail_skb = &(skb_shinfo(skb)->frag_list);
1333
1334         /* move skb->data to ip header from ext header */
1335         if (skb->data < skb_network_header(skb))
1336                 __skb_pull(skb, skb_network_offset(skb));
1337         while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) {
1338                 __skb_pull(tmp_skb, skb->h.raw - skb->nh.raw);
1339                 *tail_skb = tmp_skb;
1340                 tail_skb = &(tmp_skb->next);
1341                 skb->len += tmp_skb->len;
1342                 skb->data_len += tmp_skb->len;
1343                 skb->truesize += tmp_skb->truesize;
1344                 __sock_put(tmp_skb->sk);
1345                 tmp_skb->destructor = NULL;
1346                 tmp_skb->sk = NULL;
1347         }
1348
1349         ipv6_addr_copy(final_dst, &fl->fl6_dst);
1350         __skb_pull(skb, skb->h.raw - skb->nh.raw);
1351         if (opt && opt->opt_flen)
1352                 ipv6_push_frag_opts(skb, opt, &proto);
1353         if (opt && opt->opt_nflen)
1354                 ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst);
1355
1356         skb_push(skb, sizeof(struct ipv6hdr));
1357         skb_reset_network_header(skb);
1358         hdr = skb->nh.ipv6h;
1359
1360         *(__be32*)hdr = fl->fl6_flowlabel |
1361                      htonl(0x60000000 | ((int)np->cork.tclass << 20));
1362
1363         if (skb->len <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN)
1364                 hdr->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
1365         else
1366                 hdr->payload_len = 0;
1367         hdr->hop_limit = np->cork.hop_limit;
1368         hdr->nexthdr = proto;
1369         ipv6_addr_copy(&hdr->saddr, &fl->fl6_src);
1370         ipv6_addr_copy(&hdr->daddr, final_dst);
1371
1372         skb->priority = sk->sk_priority;
1373
1374         skb->dst = dst_clone(&rt->u.dst);
1375         IP6_INC_STATS(rt->rt6i_idev, IPSTATS_MIB_OUTREQUESTS);
1376         err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, skb->dst->dev, dst_output);
1377         if (err) {
1378                 if (err > 0)
1379                         err = np->recverr ? net_xmit_errno(err) : 0;
1380                 if (err)
1381                         goto error;
1382         }
1383
1384 out:
1385         inet->cork.flags &= ~IPCORK_OPT;
1386         kfree(np->cork.opt);
1387         np->cork.opt = NULL;
1388         if (np->cork.rt) {
1389                 dst_release(&np->cork.rt->u.dst);
1390                 np->cork.rt = NULL;
1391                 inet->cork.flags &= ~IPCORK_ALLFRAG;
1392         }
1393         memset(&inet->cork.fl, 0, sizeof(inet->cork.fl));
1394         return err;
1395 error:
1396         goto out;
1397 }
1398
1399 void ip6_flush_pending_frames(struct sock *sk)
1400 {
1401         struct inet_sock *inet = inet_sk(sk);
1402         struct ipv6_pinfo *np = inet6_sk(sk);
1403         struct sk_buff *skb;
1404
1405         while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) {
1406                 IP6_INC_STATS(ip6_dst_idev(skb->dst),
1407                               IPSTATS_MIB_OUTDISCARDS);
1408                 kfree_skb(skb);
1409         }
1410
1411         inet->cork.flags &= ~IPCORK_OPT;
1412
1413         kfree(np->cork.opt);
1414         np->cork.opt = NULL;
1415         if (np->cork.rt) {
1416                 dst_release(&np->cork.rt->u.dst);
1417                 np->cork.rt = NULL;
1418                 inet->cork.flags &= ~IPCORK_ALLFRAG;
1419         }
1420         memset(&inet->cork.fl, 0, sizeof(inet->cork.fl));
1421 }