[IPV6] NDISC: Add proxy_ndp sysctl.
[linux-2.6.git] / 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 int ip6_forward_proxy_check(struct sk_buff *skb)
312 {
313         struct ipv6hdr *hdr = skb->nh.ipv6h;
314         u8 nexthdr = hdr->nexthdr;
315         int offset;
316
317         if (ipv6_ext_hdr(nexthdr)) {
318                 offset = ipv6_skip_exthdr(skb, sizeof(*hdr), &nexthdr);
319                 if (offset < 0)
320                         return 0;
321         } else
322                 offset = sizeof(struct ipv6hdr);
323
324         if (nexthdr == IPPROTO_ICMPV6) {
325                 struct icmp6hdr *icmp6;
326
327                 if (!pskb_may_pull(skb, skb->nh.raw + offset + 1 - skb->data))
328                         return 0;
329
330                 icmp6 = (struct icmp6hdr *)(skb->nh.raw + 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(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->nh.raw + 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(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(IPSTATS_MIB_INDISCARDS);
423                         goto drop;
424                 }
425         }
426
427         if (!xfrm6_route_forward(skb)) {
428                 IP6_INC_STATS(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(IPSTATS_MIB_INTOOBIGERRORS);
468                 IP6_INC_STATS_BH(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(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(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(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
503 #ifdef CONFIG_NET_SCHED
504         to->tc_index = from->tc_index;
505 #endif
506 #ifdef CONFIG_NETFILTER
507         to->nfmark = from->nfmark;
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->nh.raw;
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->nh.raw + offset);
559         }
560
561         return offset;
562 }
563 EXPORT_SYMBOL_GPL(ip6_find_1stfragopt);
564
565 static int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *))
566 {
567         struct net_device *dev;
568         struct sk_buff *frag;
569         struct rt6_info *rt = (struct rt6_info*)skb->dst;
570         struct ipv6_pinfo *np = skb->sk ? inet6_sk(skb->sk) : NULL;
571         struct ipv6hdr *tmp_hdr;
572         struct frag_hdr *fh;
573         unsigned int mtu, hlen, left, len;
574         u32 frag_id = 0;
575         int ptr, offset = 0, err=0;
576         u8 *prevhdr, nexthdr = 0;
577
578         dev = rt->u.dst.dev;
579         hlen = ip6_find_1stfragopt(skb, &prevhdr);
580         nexthdr = *prevhdr;
581
582         mtu = dst_mtu(&rt->u.dst);
583         if (np && np->frag_size < mtu) {
584                 if (np->frag_size)
585                         mtu = np->frag_size;
586         }
587         mtu -= hlen + sizeof(struct frag_hdr);
588
589         if (skb_shinfo(skb)->frag_list) {
590                 int first_len = skb_pagelen(skb);
591
592                 if (first_len - hlen > mtu ||
593                     ((first_len - hlen) & 7) ||
594                     skb_cloned(skb))
595                         goto slow_path;
596
597                 for (frag = skb_shinfo(skb)->frag_list; frag; frag = frag->next) {
598                         /* Correct geometry. */
599                         if (frag->len > mtu ||
600                             ((frag->len & 7) && frag->next) ||
601                             skb_headroom(frag) < hlen)
602                             goto slow_path;
603
604                         /* Partially cloned skb? */
605                         if (skb_shared(frag))
606                                 goto slow_path;
607
608                         BUG_ON(frag->sk);
609                         if (skb->sk) {
610                                 sock_hold(skb->sk);
611                                 frag->sk = skb->sk;
612                                 frag->destructor = sock_wfree;
613                                 skb->truesize -= frag->truesize;
614                         }
615                 }
616
617                 err = 0;
618                 offset = 0;
619                 frag = skb_shinfo(skb)->frag_list;
620                 skb_shinfo(skb)->frag_list = NULL;
621                 /* BUILD HEADER */
622
623                 tmp_hdr = kmalloc(hlen, GFP_ATOMIC);
624                 if (!tmp_hdr) {
625                         IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
626                         return -ENOMEM;
627                 }
628
629                 *prevhdr = NEXTHDR_FRAGMENT;
630                 memcpy(tmp_hdr, skb->nh.raw, hlen);
631                 __skb_pull(skb, hlen);
632                 fh = (struct frag_hdr*)__skb_push(skb, sizeof(struct frag_hdr));
633                 skb->nh.raw = __skb_push(skb, hlen);
634                 memcpy(skb->nh.raw, tmp_hdr, hlen);
635
636                 ipv6_select_ident(skb, fh);
637                 fh->nexthdr = nexthdr;
638                 fh->reserved = 0;
639                 fh->frag_off = htons(IP6_MF);
640                 frag_id = fh->identification;
641
642                 first_len = skb_pagelen(skb);
643                 skb->data_len = first_len - skb_headlen(skb);
644                 skb->len = first_len;
645                 skb->nh.ipv6h->payload_len = htons(first_len - sizeof(struct ipv6hdr));
646  
647
648                 for (;;) {
649                         /* Prepare header of the next frame,
650                          * before previous one went down. */
651                         if (frag) {
652                                 frag->ip_summed = CHECKSUM_NONE;
653                                 frag->h.raw = frag->data;
654                                 fh = (struct frag_hdr*)__skb_push(frag, sizeof(struct frag_hdr));
655                                 frag->nh.raw = __skb_push(frag, hlen);
656                                 memcpy(frag->nh.raw, tmp_hdr, hlen);
657                                 offset += skb->len - hlen - sizeof(struct frag_hdr);
658                                 fh->nexthdr = nexthdr;
659                                 fh->reserved = 0;
660                                 fh->frag_off = htons(offset);
661                                 if (frag->next != NULL)
662                                         fh->frag_off |= htons(IP6_MF);
663                                 fh->identification = frag_id;
664                                 frag->nh.ipv6h->payload_len = htons(frag->len - sizeof(struct ipv6hdr));
665                                 ip6_copy_metadata(frag, skb);
666                         }
667                         
668                         err = output(skb);
669                         if(!err)
670                                 IP6_INC_STATS(IPSTATS_MIB_FRAGCREATES);
671
672                         if (err || !frag)
673                                 break;
674
675                         skb = frag;
676                         frag = skb->next;
677                         skb->next = NULL;
678                 }
679
680                 kfree(tmp_hdr);
681
682                 if (err == 0) {
683                         IP6_INC_STATS(IPSTATS_MIB_FRAGOKS);
684                         return 0;
685                 }
686
687                 while (frag) {
688                         skb = frag->next;
689                         kfree_skb(frag);
690                         frag = skb;
691                 }
692
693                 IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
694                 return err;
695         }
696
697 slow_path:
698         left = skb->len - hlen;         /* Space per frame */
699         ptr = hlen;                     /* Where to start from */
700
701         /*
702          *      Fragment the datagram.
703          */
704
705         *prevhdr = NEXTHDR_FRAGMENT;
706
707         /*
708          *      Keep copying data until we run out.
709          */
710         while(left > 0) {
711                 len = left;
712                 /* IF: it doesn't fit, use 'mtu' - the data space left */
713                 if (len > mtu)
714                         len = mtu;
715                 /* IF: we are not sending upto and including the packet end
716                    then align the next start on an eight byte boundary */
717                 if (len < left) {
718                         len &= ~7;
719                 }
720                 /*
721                  *      Allocate buffer.
722                  */
723
724                 if ((frag = alloc_skb(len+hlen+sizeof(struct frag_hdr)+LL_RESERVED_SPACE(rt->u.dst.dev), GFP_ATOMIC)) == NULL) {
725                         NETDEBUG(KERN_INFO "IPv6: frag: no memory for new fragment!\n");
726                         IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
727                         err = -ENOMEM;
728                         goto fail;
729                 }
730
731                 /*
732                  *      Set up data on packet
733                  */
734
735                 ip6_copy_metadata(frag, skb);
736                 skb_reserve(frag, LL_RESERVED_SPACE(rt->u.dst.dev));
737                 skb_put(frag, len + hlen + sizeof(struct frag_hdr));
738                 frag->nh.raw = frag->data;
739                 fh = (struct frag_hdr*)(frag->data + hlen);
740                 frag->h.raw = frag->data + hlen + sizeof(struct frag_hdr);
741
742                 /*
743                  *      Charge the memory for the fragment to any owner
744                  *      it might possess
745                  */
746                 if (skb->sk)
747                         skb_set_owner_w(frag, skb->sk);
748
749                 /*
750                  *      Copy the packet header into the new buffer.
751                  */
752                 memcpy(frag->nh.raw, skb->data, hlen);
753
754                 /*
755                  *      Build fragment header.
756                  */
757                 fh->nexthdr = nexthdr;
758                 fh->reserved = 0;
759                 if (!frag_id) {
760                         ipv6_select_ident(skb, fh);
761                         frag_id = fh->identification;
762                 } else
763                         fh->identification = frag_id;
764
765                 /*
766                  *      Copy a block of the IP datagram.
767                  */
768                 if (skb_copy_bits(skb, ptr, frag->h.raw, len))
769                         BUG();
770                 left -= len;
771
772                 fh->frag_off = htons(offset);
773                 if (left > 0)
774                         fh->frag_off |= htons(IP6_MF);
775                 frag->nh.ipv6h->payload_len = htons(frag->len - sizeof(struct ipv6hdr));
776
777                 ptr += len;
778                 offset += len;
779
780                 /*
781                  *      Put this fragment into the sending queue.
782                  */
783                 err = output(frag);
784                 if (err)
785                         goto fail;
786
787                 IP6_INC_STATS(IPSTATS_MIB_FRAGCREATES);
788         }
789         kfree_skb(skb);
790         IP6_INC_STATS(IPSTATS_MIB_FRAGOKS);
791         return err;
792
793 fail:
794         kfree_skb(skb); 
795         IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
796         return err;
797 }
798
799 static inline int ip6_rt_check(struct rt6key *rt_key,
800                                struct in6_addr *fl_addr,
801                                struct in6_addr *addr_cache)
802 {
803         return ((rt_key->plen != 128 || !ipv6_addr_equal(fl_addr, &rt_key->addr)) &&
804                 (addr_cache == NULL || !ipv6_addr_equal(fl_addr, addr_cache)));
805 }
806
807 static struct dst_entry *ip6_sk_dst_check(struct sock *sk,
808                                           struct dst_entry *dst,
809                                           struct flowi *fl)
810 {
811         struct ipv6_pinfo *np = inet6_sk(sk);
812         struct rt6_info *rt = (struct rt6_info *)dst;
813
814         if (!dst)
815                 goto out;
816
817         /* Yes, checking route validity in not connected
818          * case is not very simple. Take into account,
819          * that we do not support routing by source, TOS,
820          * and MSG_DONTROUTE            --ANK (980726)
821          *
822          * 1. ip6_rt_check(): If route was host route,
823          *    check that cached destination is current.
824          *    If it is network route, we still may
825          *    check its validity using saved pointer
826          *    to the last used address: daddr_cache.
827          *    We do not want to save whole address now,
828          *    (because main consumer of this service
829          *    is tcp, which has not this problem),
830          *    so that the last trick works only on connected
831          *    sockets.
832          * 2. oif also should be the same.
833          */
834         if (ip6_rt_check(&rt->rt6i_dst, &fl->fl6_dst, np->daddr_cache) ||
835 #ifdef CONFIG_IPV6_SUBTREES
836             ip6_rt_check(&rt->rt6i_src, &fl->fl6_src, np->saddr_cache) ||
837 #endif
838             (fl->oif && fl->oif != dst->dev->ifindex)) {
839                 dst_release(dst);
840                 dst = NULL;
841         }
842
843 out:
844         return dst;
845 }
846
847 static int ip6_dst_lookup_tail(struct sock *sk,
848                                struct dst_entry **dst, struct flowi *fl)
849 {
850         int err;
851
852         if (*dst == NULL)
853                 *dst = ip6_route_output(sk, fl);
854
855         if ((err = (*dst)->error))
856                 goto out_err_release;
857
858         if (ipv6_addr_any(&fl->fl6_src)) {
859                 err = ipv6_get_saddr(*dst, &fl->fl6_dst, &fl->fl6_src);
860                 if (err)
861                         goto out_err_release;
862         }
863
864         return 0;
865
866 out_err_release:
867         dst_release(*dst);
868         *dst = NULL;
869         return err;
870 }
871
872 /**
873  *      ip6_dst_lookup - perform route lookup on flow
874  *      @sk: socket which provides route info
875  *      @dst: pointer to dst_entry * for result
876  *      @fl: flow to lookup
877  *
878  *      This function performs a route lookup on the given flow.
879  *
880  *      It returns zero on success, or a standard errno code on error.
881  */
882 int ip6_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi *fl)
883 {
884         *dst = NULL;
885         return ip6_dst_lookup_tail(sk, dst, fl);
886 }
887 EXPORT_SYMBOL_GPL(ip6_dst_lookup);
888
889 /**
890  *      ip6_sk_dst_lookup - perform socket cached route lookup on flow
891  *      @sk: socket which provides the dst cache and route info
892  *      @dst: pointer to dst_entry * for result
893  *      @fl: flow to lookup
894  *
895  *      This function performs a route lookup on the given flow with the
896  *      possibility of using the cached route in the socket if it is valid.
897  *      It will take the socket dst lock when operating on the dst cache.
898  *      As a result, this function can only be used in process context.
899  *
900  *      It returns zero on success, or a standard errno code on error.
901  */
902 int ip6_sk_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi *fl)
903 {
904         *dst = NULL;
905         if (sk) {
906                 *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie);
907                 *dst = ip6_sk_dst_check(sk, *dst, fl);
908         }
909
910         return ip6_dst_lookup_tail(sk, dst, fl);
911 }
912 EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup);
913
914 static inline int ip6_ufo_append_data(struct sock *sk,
915                         int getfrag(void *from, char *to, int offset, int len,
916                         int odd, struct sk_buff *skb),
917                         void *from, int length, int hh_len, int fragheaderlen,
918                         int transhdrlen, int mtu,unsigned int flags)
919
920 {
921         struct sk_buff *skb;
922         int err;
923
924         /* There is support for UDP large send offload by network
925          * device, so create one single skb packet containing complete
926          * udp datagram
927          */
928         if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) {
929                 skb = sock_alloc_send_skb(sk,
930                         hh_len + fragheaderlen + transhdrlen + 20,
931                         (flags & MSG_DONTWAIT), &err);
932                 if (skb == NULL)
933                         return -ENOMEM;
934
935                 /* reserve space for Hardware header */
936                 skb_reserve(skb, hh_len);
937
938                 /* create space for UDP/IP header */
939                 skb_put(skb,fragheaderlen + transhdrlen);
940
941                 /* initialize network header pointer */
942                 skb->nh.raw = skb->data;
943
944                 /* initialize protocol header pointer */
945                 skb->h.raw = skb->data + fragheaderlen;
946
947                 skb->ip_summed = CHECKSUM_PARTIAL;
948                 skb->csum = 0;
949                 sk->sk_sndmsg_off = 0;
950         }
951
952         err = skb_append_datato_frags(sk,skb, getfrag, from,
953                                       (length - transhdrlen));
954         if (!err) {
955                 struct frag_hdr fhdr;
956
957                 /* specify the length of each IP datagram fragment*/
958                 skb_shinfo(skb)->gso_size = mtu - fragheaderlen - 
959                                             sizeof(struct frag_hdr);
960                 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
961                 ipv6_select_ident(skb, &fhdr);
962                 skb_shinfo(skb)->ip6_frag_id = fhdr.identification;
963                 __skb_queue_tail(&sk->sk_write_queue, skb);
964
965                 return 0;
966         }
967         /* There is not enough support do UPD LSO,
968          * so follow normal path
969          */
970         kfree_skb(skb);
971
972         return err;
973 }
974
975 int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
976         int offset, int len, int odd, struct sk_buff *skb),
977         void *from, int length, int transhdrlen,
978         int hlimit, int tclass, struct ipv6_txoptions *opt, struct flowi *fl,
979         struct rt6_info *rt, unsigned int flags)
980 {
981         struct inet_sock *inet = inet_sk(sk);
982         struct ipv6_pinfo *np = inet6_sk(sk);
983         struct sk_buff *skb;
984         unsigned int maxfraglen, fragheaderlen;
985         int exthdrlen;
986         int hh_len;
987         int mtu;
988         int copy;
989         int err;
990         int offset = 0;
991         int csummode = CHECKSUM_NONE;
992
993         if (flags&MSG_PROBE)
994                 return 0;
995         if (skb_queue_empty(&sk->sk_write_queue)) {
996                 /*
997                  * setup for corking
998                  */
999                 if (opt) {
1000                         if (np->cork.opt == NULL) {
1001                                 np->cork.opt = kmalloc(opt->tot_len,
1002                                                        sk->sk_allocation);
1003                                 if (unlikely(np->cork.opt == NULL))
1004                                         return -ENOBUFS;
1005                         } else if (np->cork.opt->tot_len < opt->tot_len) {
1006                                 printk(KERN_DEBUG "ip6_append_data: invalid option length\n");
1007                                 return -EINVAL;
1008                         }
1009                         memcpy(np->cork.opt, opt, opt->tot_len);
1010                         inet->cork.flags |= IPCORK_OPT;
1011                         /* need source address above miyazawa*/
1012                 }
1013                 dst_hold(&rt->u.dst);
1014                 np->cork.rt = rt;
1015                 inet->cork.fl = *fl;
1016                 np->cork.hop_limit = hlimit;
1017                 np->cork.tclass = tclass;
1018                 mtu = dst_mtu(rt->u.dst.path);
1019                 if (np->frag_size < mtu) {
1020                         if (np->frag_size)
1021                                 mtu = np->frag_size;
1022                 }
1023                 inet->cork.fragsize = mtu;
1024                 if (dst_allfrag(rt->u.dst.path))
1025                         inet->cork.flags |= IPCORK_ALLFRAG;
1026                 inet->cork.length = 0;
1027                 sk->sk_sndmsg_page = NULL;
1028                 sk->sk_sndmsg_off = 0;
1029                 exthdrlen = rt->u.dst.header_len + (opt ? opt->opt_flen : 0);
1030                 length += exthdrlen;
1031                 transhdrlen += exthdrlen;
1032         } else {
1033                 rt = np->cork.rt;
1034                 fl = &inet->cork.fl;
1035                 if (inet->cork.flags & IPCORK_OPT)
1036                         opt = np->cork.opt;
1037                 transhdrlen = 0;
1038                 exthdrlen = 0;
1039                 mtu = inet->cork.fragsize;
1040         }
1041
1042         hh_len = LL_RESERVED_SPACE(rt->u.dst.dev);
1043
1044         fragheaderlen = sizeof(struct ipv6hdr) + rt->u.dst.nfheader_len + (opt ? opt->opt_nflen : 0);
1045         maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - sizeof(struct frag_hdr);
1046
1047         if (mtu <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN) {
1048                 if (inet->cork.length + length > sizeof(struct ipv6hdr) + IPV6_MAXPLEN - fragheaderlen) {
1049                         ipv6_local_error(sk, EMSGSIZE, fl, mtu-exthdrlen);
1050                         return -EMSGSIZE;
1051                 }
1052         }
1053
1054         /*
1055          * Let's try using as much space as possible.
1056          * Use MTU if total length of the message fits into the MTU.
1057          * Otherwise, we need to reserve fragment header and
1058          * fragment alignment (= 8-15 octects, in total).
1059          *
1060          * Note that we may need to "move" the data from the tail of
1061          * of the buffer to the new fragment when we split 
1062          * the message.
1063          *
1064          * FIXME: It may be fragmented into multiple chunks 
1065          *        at once if non-fragmentable extension headers
1066          *        are too large.
1067          * --yoshfuji 
1068          */
1069
1070         inet->cork.length += length;
1071         if (((length > mtu) && (sk->sk_protocol == IPPROTO_UDP)) &&
1072             (rt->u.dst.dev->features & NETIF_F_UFO)) {
1073
1074                 err = ip6_ufo_append_data(sk, getfrag, from, length, hh_len,
1075                                           fragheaderlen, transhdrlen, mtu,
1076                                           flags);
1077                 if (err)
1078                         goto error;
1079                 return 0;
1080         }
1081
1082         if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL)
1083                 goto alloc_new_skb;
1084
1085         while (length > 0) {
1086                 /* Check if the remaining data fits into current packet. */
1087                 copy = (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len;
1088                 if (copy < length)
1089                         copy = maxfraglen - skb->len;
1090
1091                 if (copy <= 0) {
1092                         char *data;
1093                         unsigned int datalen;
1094                         unsigned int fraglen;
1095                         unsigned int fraggap;
1096                         unsigned int alloclen;
1097                         struct sk_buff *skb_prev;
1098 alloc_new_skb:
1099                         skb_prev = skb;
1100
1101                         /* There's no room in the current skb */
1102                         if (skb_prev)
1103                                 fraggap = skb_prev->len - maxfraglen;
1104                         else
1105                                 fraggap = 0;
1106
1107                         /*
1108                          * If remaining data exceeds the mtu,
1109                          * we know we need more fragment(s).
1110                          */
1111                         datalen = length + fraggap;
1112                         if (datalen > (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen)
1113                                 datalen = maxfraglen - fragheaderlen;
1114
1115                         fraglen = datalen + fragheaderlen;
1116                         if ((flags & MSG_MORE) &&
1117                             !(rt->u.dst.dev->features&NETIF_F_SG))
1118                                 alloclen = mtu;
1119                         else
1120                                 alloclen = datalen + fragheaderlen;
1121
1122                         /*
1123                          * The last fragment gets additional space at tail.
1124                          * Note: we overallocate on fragments with MSG_MODE
1125                          * because we have no idea if we're the last one.
1126                          */
1127                         if (datalen == length + fraggap)
1128                                 alloclen += rt->u.dst.trailer_len;
1129
1130                         /*
1131                          * We just reserve space for fragment header.
1132                          * Note: this may be overallocation if the message 
1133                          * (without MSG_MORE) fits into the MTU.
1134                          */
1135                         alloclen += sizeof(struct frag_hdr);
1136
1137                         if (transhdrlen) {
1138                                 skb = sock_alloc_send_skb(sk,
1139                                                 alloclen + hh_len,
1140                                                 (flags & MSG_DONTWAIT), &err);
1141                         } else {
1142                                 skb = NULL;
1143                                 if (atomic_read(&sk->sk_wmem_alloc) <=
1144                                     2 * sk->sk_sndbuf)
1145                                         skb = sock_wmalloc(sk,
1146                                                            alloclen + hh_len, 1,
1147                                                            sk->sk_allocation);
1148                                 if (unlikely(skb == NULL))
1149                                         err = -ENOBUFS;
1150                         }
1151                         if (skb == NULL)
1152                                 goto error;
1153                         /*
1154                          *      Fill in the control structures
1155                          */
1156                         skb->ip_summed = csummode;
1157                         skb->csum = 0;
1158                         /* reserve for fragmentation */
1159                         skb_reserve(skb, hh_len+sizeof(struct frag_hdr));
1160
1161                         /*
1162                          *      Find where to start putting bytes
1163                          */
1164                         data = skb_put(skb, fraglen);
1165                         skb->nh.raw = data + exthdrlen;
1166                         data += fragheaderlen;
1167                         skb->h.raw = data + exthdrlen;
1168
1169                         if (fraggap) {
1170                                 skb->csum = skb_copy_and_csum_bits(
1171                                         skb_prev, maxfraglen,
1172                                         data + transhdrlen, fraggap, 0);
1173                                 skb_prev->csum = csum_sub(skb_prev->csum,
1174                                                           skb->csum);
1175                                 data += fraggap;
1176                                 pskb_trim_unique(skb_prev, maxfraglen);
1177                         }
1178                         copy = datalen - transhdrlen - fraggap;
1179                         if (copy < 0) {
1180                                 err = -EINVAL;
1181                                 kfree_skb(skb);
1182                                 goto error;
1183                         } else if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) {
1184                                 err = -EFAULT;
1185                                 kfree_skb(skb);
1186                                 goto error;
1187                         }
1188
1189                         offset += copy;
1190                         length -= datalen - fraggap;
1191                         transhdrlen = 0;
1192                         exthdrlen = 0;
1193                         csummode = CHECKSUM_NONE;
1194
1195                         /*
1196                          * Put the packet on the pending queue
1197                          */
1198                         __skb_queue_tail(&sk->sk_write_queue, skb);
1199                         continue;
1200                 }
1201
1202                 if (copy > length)
1203                         copy = length;
1204
1205                 if (!(rt->u.dst.dev->features&NETIF_F_SG)) {
1206                         unsigned int off;
1207
1208                         off = skb->len;
1209                         if (getfrag(from, skb_put(skb, copy),
1210                                                 offset, copy, off, skb) < 0) {
1211                                 __skb_trim(skb, off);
1212                                 err = -EFAULT;
1213                                 goto error;
1214                         }
1215                 } else {
1216                         int i = skb_shinfo(skb)->nr_frags;
1217                         skb_frag_t *frag = &skb_shinfo(skb)->frags[i-1];
1218                         struct page *page = sk->sk_sndmsg_page;
1219                         int off = sk->sk_sndmsg_off;
1220                         unsigned int left;
1221
1222                         if (page && (left = PAGE_SIZE - off) > 0) {
1223                                 if (copy >= left)
1224                                         copy = left;
1225                                 if (page != frag->page) {
1226                                         if (i == MAX_SKB_FRAGS) {
1227                                                 err = -EMSGSIZE;
1228                                                 goto error;
1229                                         }
1230                                         get_page(page);
1231                                         skb_fill_page_desc(skb, i, page, sk->sk_sndmsg_off, 0);
1232                                         frag = &skb_shinfo(skb)->frags[i];
1233                                 }
1234                         } else if(i < MAX_SKB_FRAGS) {
1235                                 if (copy > PAGE_SIZE)
1236                                         copy = PAGE_SIZE;
1237                                 page = alloc_pages(sk->sk_allocation, 0);
1238                                 if (page == NULL) {
1239                                         err = -ENOMEM;
1240                                         goto error;
1241                                 }
1242                                 sk->sk_sndmsg_page = page;
1243                                 sk->sk_sndmsg_off = 0;
1244
1245                                 skb_fill_page_desc(skb, i, page, 0, 0);
1246                                 frag = &skb_shinfo(skb)->frags[i];
1247                                 skb->truesize += PAGE_SIZE;
1248                                 atomic_add(PAGE_SIZE, &sk->sk_wmem_alloc);
1249                         } else {
1250                                 err = -EMSGSIZE;
1251                                 goto error;
1252                         }
1253                         if (getfrag(from, page_address(frag->page)+frag->page_offset+frag->size, offset, copy, skb->len, skb) < 0) {
1254                                 err = -EFAULT;
1255                                 goto error;
1256                         }
1257                         sk->sk_sndmsg_off += copy;
1258                         frag->size += copy;
1259                         skb->len += copy;
1260                         skb->data_len += copy;
1261                 }
1262                 offset += copy;
1263                 length -= copy;
1264         }
1265         return 0;
1266 error:
1267         inet->cork.length -= length;
1268         IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
1269         return err;
1270 }
1271
1272 int ip6_push_pending_frames(struct sock *sk)
1273 {
1274         struct sk_buff *skb, *tmp_skb;
1275         struct sk_buff **tail_skb;
1276         struct in6_addr final_dst_buf, *final_dst = &final_dst_buf;
1277         struct inet_sock *inet = inet_sk(sk);
1278         struct ipv6_pinfo *np = inet6_sk(sk);
1279         struct ipv6hdr *hdr;
1280         struct ipv6_txoptions *opt = np->cork.opt;
1281         struct rt6_info *rt = np->cork.rt;
1282         struct flowi *fl = &inet->cork.fl;
1283         unsigned char proto = fl->proto;
1284         int err = 0;
1285
1286         if ((skb = __skb_dequeue(&sk->sk_write_queue)) == NULL)
1287                 goto out;
1288         tail_skb = &(skb_shinfo(skb)->frag_list);
1289
1290         /* move skb->data to ip header from ext header */
1291         if (skb->data < skb->nh.raw)
1292                 __skb_pull(skb, skb->nh.raw - skb->data);
1293         while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) {
1294                 __skb_pull(tmp_skb, skb->h.raw - skb->nh.raw);
1295                 *tail_skb = tmp_skb;
1296                 tail_skb = &(tmp_skb->next);
1297                 skb->len += tmp_skb->len;
1298                 skb->data_len += tmp_skb->len;
1299                 skb->truesize += tmp_skb->truesize;
1300                 __sock_put(tmp_skb->sk);
1301                 tmp_skb->destructor = NULL;
1302                 tmp_skb->sk = NULL;
1303         }
1304
1305         ipv6_addr_copy(final_dst, &fl->fl6_dst);
1306         __skb_pull(skb, skb->h.raw - skb->nh.raw);
1307         if (opt && opt->opt_flen)
1308                 ipv6_push_frag_opts(skb, opt, &proto);
1309         if (opt && opt->opt_nflen)
1310                 ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst);
1311
1312         skb->nh.ipv6h = hdr = (struct ipv6hdr*) skb_push(skb, sizeof(struct ipv6hdr));
1313         
1314         *(u32*)hdr = fl->fl6_flowlabel |
1315                      htonl(0x60000000 | ((int)np->cork.tclass << 20));
1316
1317         if (skb->len <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN)
1318                 hdr->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
1319         else
1320                 hdr->payload_len = 0;
1321         hdr->hop_limit = np->cork.hop_limit;
1322         hdr->nexthdr = proto;
1323         ipv6_addr_copy(&hdr->saddr, &fl->fl6_src);
1324         ipv6_addr_copy(&hdr->daddr, final_dst);
1325
1326         skb->priority = sk->sk_priority;
1327
1328         skb->dst = dst_clone(&rt->u.dst);
1329         IP6_INC_STATS(IPSTATS_MIB_OUTREQUESTS); 
1330         err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, skb->dst->dev, dst_output);
1331         if (err) {
1332                 if (err > 0)
1333                         err = np->recverr ? net_xmit_errno(err) : 0;
1334                 if (err)
1335                         goto error;
1336         }
1337
1338 out:
1339         inet->cork.flags &= ~IPCORK_OPT;
1340         kfree(np->cork.opt);
1341         np->cork.opt = NULL;
1342         if (np->cork.rt) {
1343                 dst_release(&np->cork.rt->u.dst);
1344                 np->cork.rt = NULL;
1345                 inet->cork.flags &= ~IPCORK_ALLFRAG;
1346         }
1347         memset(&inet->cork.fl, 0, sizeof(inet->cork.fl));
1348         return err;
1349 error:
1350         goto out;
1351 }
1352
1353 void ip6_flush_pending_frames(struct sock *sk)
1354 {
1355         struct inet_sock *inet = inet_sk(sk);
1356         struct ipv6_pinfo *np = inet6_sk(sk);
1357         struct sk_buff *skb;
1358
1359         while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) {
1360                 IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
1361                 kfree_skb(skb);
1362         }
1363
1364         inet->cork.flags &= ~IPCORK_OPT;
1365
1366         kfree(np->cork.opt);
1367         np->cork.opt = NULL;
1368         if (np->cork.rt) {
1369                 dst_release(&np->cork.rt->u.dst);
1370                 np->cork.rt = NULL;
1371                 inet->cork.flags &= ~IPCORK_ALLFRAG;
1372         }
1373         memset(&inet->cork.fl, 0, sizeof(inet->cork.fl));
1374 }