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