[SK_BUFF]: Introduce skb_reset_transport_header(skb)
[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         struct dst_entry *dst = skb->dst;
76
77         if (dst->hh)
78                 return neigh_hh_output(dst->hh, skb);
79         else if (dst->neighbour)
80                 return dst->neighbour->output(skb);
81
82         IP6_INC_STATS_BH(ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
83         kfree_skb(skb);
84         return -EINVAL;
85
86 }
87
88 /* dev_loopback_xmit for use with netfilter. */
89 static int ip6_dev_loopback_xmit(struct sk_buff *newskb)
90 {
91         skb_reset_mac_header(newskb);
92         __skb_pull(newskb, skb_network_offset(newskb));
93         newskb->pkt_type = PACKET_LOOPBACK;
94         newskb->ip_summed = CHECKSUM_UNNECESSARY;
95         BUG_TRAP(newskb->dst);
96
97         netif_rx(newskb);
98         return 0;
99 }
100
101
102 static int ip6_output2(struct sk_buff *skb)
103 {
104         struct dst_entry *dst = skb->dst;
105         struct net_device *dev = dst->dev;
106
107         skb->protocol = htons(ETH_P_IPV6);
108         skb->dev = dev;
109
110         if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) {
111                 struct ipv6_pinfo* np = skb->sk ? inet6_sk(skb->sk) : NULL;
112                 struct inet6_dev *idev = ip6_dst_idev(skb->dst);
113
114                 if (!(dev->flags & IFF_LOOPBACK) && (!np || np->mc_loop) &&
115                     ipv6_chk_mcast_addr(dev, &ipv6_hdr(skb)->daddr,
116                                         &ipv6_hdr(skb)->saddr)) {
117                         struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC);
118
119                         /* Do not check for IFF_ALLMULTI; multicast routing
120                            is not supported in any case.
121                          */
122                         if (newskb)
123                                 NF_HOOK(PF_INET6, NF_IP6_POST_ROUTING, newskb, NULL,
124                                         newskb->dev,
125                                         ip6_dev_loopback_xmit);
126
127                         if (ipv6_hdr(skb)->hop_limit == 0) {
128                                 IP6_INC_STATS(idev, IPSTATS_MIB_OUTDISCARDS);
129                                 kfree_skb(skb);
130                                 return 0;
131                         }
132                 }
133
134                 IP6_INC_STATS(idev, IPSTATS_MIB_OUTMCASTPKTS);
135         }
136
137         return NF_HOOK(PF_INET6, NF_IP6_POST_ROUTING, skb,NULL, skb->dev,ip6_output_finish);
138 }
139
140 int ip6_output(struct sk_buff *skb)
141 {
142         if ((skb->len > dst_mtu(skb->dst) && !skb_is_gso(skb)) ||
143                                 dst_allfrag(skb->dst))
144                 return ip6_fragment(skb, ip6_output2);
145         else
146                 return ip6_output2(skb);
147 }
148
149 /*
150  *      xmit an sk_buff (used by TCP)
151  */
152
153 int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl,
154              struct ipv6_txoptions *opt, int ipfragok)
155 {
156         struct ipv6_pinfo *np = inet6_sk(sk);
157         struct in6_addr *first_hop = &fl->fl6_dst;
158         struct dst_entry *dst = skb->dst;
159         struct ipv6hdr *hdr;
160         u8  proto = fl->proto;
161         int seg_len = skb->len;
162         int hlimit, tclass;
163         u32 mtu;
164
165         if (opt) {
166                 int head_room;
167
168                 /* First: exthdrs may take lots of space (~8K for now)
169                    MAX_HEADER is not enough.
170                  */
171                 head_room = opt->opt_nflen + opt->opt_flen;
172                 seg_len += head_room;
173                 head_room += sizeof(struct ipv6hdr) + LL_RESERVED_SPACE(dst->dev);
174
175                 if (skb_headroom(skb) < head_room) {
176                         struct sk_buff *skb2 = skb_realloc_headroom(skb, head_room);
177                         if (skb2 == NULL) {
178                                 IP6_INC_STATS(ip6_dst_idev(skb->dst),
179                                               IPSTATS_MIB_OUTDISCARDS);
180                                 kfree_skb(skb);
181                                 return -ENOBUFS;
182                         }
183                         kfree_skb(skb);
184                         skb = skb2;
185                         if (sk)
186                                 skb_set_owner_w(skb, sk);
187                 }
188                 if (opt->opt_flen)
189                         ipv6_push_frag_opts(skb, opt, &proto);
190                 if (opt->opt_nflen)
191                         ipv6_push_nfrag_opts(skb, opt, &proto, &first_hop);
192         }
193
194         skb_push(skb, sizeof(struct ipv6hdr));
195         skb_reset_network_header(skb);
196         hdr = ipv6_hdr(skb);
197
198         /*
199          *      Fill in the IPv6 header
200          */
201
202         hlimit = -1;
203         if (np)
204                 hlimit = np->hop_limit;
205         if (hlimit < 0)
206                 hlimit = dst_metric(dst, RTAX_HOPLIMIT);
207         if (hlimit < 0)
208                 hlimit = ipv6_get_hoplimit(dst->dev);
209
210         tclass = -1;
211         if (np)
212                 tclass = np->tclass;
213         if (tclass < 0)
214                 tclass = 0;
215
216         *(__be32 *)hdr = htonl(0x60000000 | (tclass << 20)) | fl->fl6_flowlabel;
217
218         hdr->payload_len = htons(seg_len);
219         hdr->nexthdr = proto;
220         hdr->hop_limit = hlimit;
221
222         ipv6_addr_copy(&hdr->saddr, &fl->fl6_src);
223         ipv6_addr_copy(&hdr->daddr, first_hop);
224
225         skb->priority = sk->sk_priority;
226
227         mtu = dst_mtu(dst);
228         if ((skb->len <= mtu) || ipfragok || skb_is_gso(skb)) {
229                 IP6_INC_STATS(ip6_dst_idev(skb->dst),
230                               IPSTATS_MIB_OUTREQUESTS);
231                 return NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, dst->dev,
232                                 dst_output);
233         }
234
235         if (net_ratelimit())
236                 printk(KERN_DEBUG "IPv6: sending pkt_too_big to self\n");
237         skb->dev = dst->dev;
238         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, skb->dev);
239         IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_FRAGFAILS);
240         kfree_skb(skb);
241         return -EMSGSIZE;
242 }
243
244 EXPORT_SYMBOL(ip6_xmit);
245
246 /*
247  *      To avoid extra problems ND packets are send through this
248  *      routine. It's code duplication but I really want to avoid
249  *      extra checks since ipv6_build_header is used by TCP (which
250  *      is for us performance critical)
251  */
252
253 int ip6_nd_hdr(struct sock *sk, struct sk_buff *skb, struct net_device *dev,
254                struct in6_addr *saddr, struct in6_addr *daddr,
255                int proto, int len)
256 {
257         struct ipv6_pinfo *np = inet6_sk(sk);
258         struct ipv6hdr *hdr;
259         int totlen;
260
261         skb->protocol = htons(ETH_P_IPV6);
262         skb->dev = dev;
263
264         totlen = len + sizeof(struct ipv6hdr);
265
266         skb->nh.raw = skb_put(skb, sizeof(struct ipv6hdr));
267         hdr = ipv6_hdr(skb);
268
269         *(__be32*)hdr = htonl(0x60000000);
270
271         hdr->payload_len = htons(len);
272         hdr->nexthdr = proto;
273         hdr->hop_limit = np->hop_limit;
274
275         ipv6_addr_copy(&hdr->saddr, saddr);
276         ipv6_addr_copy(&hdr->daddr, daddr);
277
278         return 0;
279 }
280
281 static int ip6_call_ra_chain(struct sk_buff *skb, int sel)
282 {
283         struct ip6_ra_chain *ra;
284         struct sock *last = NULL;
285
286         read_lock(&ip6_ra_lock);
287         for (ra = ip6_ra_chain; ra; ra = ra->next) {
288                 struct sock *sk = ra->sk;
289                 if (sk && ra->sel == sel &&
290                     (!sk->sk_bound_dev_if ||
291                      sk->sk_bound_dev_if == skb->dev->ifindex)) {
292                         if (last) {
293                                 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
294                                 if (skb2)
295                                         rawv6_rcv(last, skb2);
296                         }
297                         last = sk;
298                 }
299         }
300
301         if (last) {
302                 rawv6_rcv(last, skb);
303                 read_unlock(&ip6_ra_lock);
304                 return 1;
305         }
306         read_unlock(&ip6_ra_lock);
307         return 0;
308 }
309
310 static int ip6_forward_proxy_check(struct sk_buff *skb)
311 {
312         struct ipv6hdr *hdr = ipv6_hdr(skb);
313         u8 nexthdr = hdr->nexthdr;
314         int offset;
315
316         if (ipv6_ext_hdr(nexthdr)) {
317                 offset = ipv6_skip_exthdr(skb, sizeof(*hdr), &nexthdr);
318                 if (offset < 0)
319                         return 0;
320         } else
321                 offset = sizeof(struct ipv6hdr);
322
323         if (nexthdr == IPPROTO_ICMPV6) {
324                 struct icmp6hdr *icmp6;
325
326                 if (!pskb_may_pull(skb, (skb_network_header(skb) +
327                                          offset + 1 - skb->data)))
328                         return 0;
329
330                 icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset);
331
332                 switch (icmp6->icmp6_type) {
333                 case NDISC_ROUTER_SOLICITATION:
334                 case NDISC_ROUTER_ADVERTISEMENT:
335                 case NDISC_NEIGHBOUR_SOLICITATION:
336                 case NDISC_NEIGHBOUR_ADVERTISEMENT:
337                 case NDISC_REDIRECT:
338                         /* For reaction involving unicast neighbor discovery
339                          * message destined to the proxied address, pass it to
340                          * input function.
341                          */
342                         return 1;
343                 default:
344                         break;
345                 }
346         }
347
348         /*
349          * The proxying router can't forward traffic sent to a link-local
350          * address, so signal the sender and discard the packet. This
351          * behavior is clarified by the MIPv6 specification.
352          */
353         if (ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) {
354                 dst_link_failure(skb);
355                 return -1;
356         }
357
358         return 0;
359 }
360
361 static inline int ip6_forward_finish(struct sk_buff *skb)
362 {
363         return dst_output(skb);
364 }
365
366 int ip6_forward(struct sk_buff *skb)
367 {
368         struct dst_entry *dst = skb->dst;
369         struct ipv6hdr *hdr = ipv6_hdr(skb);
370         struct inet6_skb_parm *opt = IP6CB(skb);
371
372         if (ipv6_devconf.forwarding == 0)
373                 goto error;
374
375         if (!xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) {
376                 IP6_INC_STATS(ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS);
377                 goto drop;
378         }
379
380         skb->ip_summed = CHECKSUM_NONE;
381
382         /*
383          *      We DO NOT make any processing on
384          *      RA packets, pushing them to user level AS IS
385          *      without ane WARRANTY that application will be able
386          *      to interpret them. The reason is that we
387          *      cannot make anything clever here.
388          *
389          *      We are not end-node, so that if packet contains
390          *      AH/ESP, we cannot make anything.
391          *      Defragmentation also would be mistake, RA packets
392          *      cannot be fragmented, because there is no warranty
393          *      that different fragments will go along one path. --ANK
394          */
395         if (opt->ra) {
396                 u8 *ptr = skb_network_header(skb) + opt->ra;
397                 if (ip6_call_ra_chain(skb, (ptr[2]<<8) + ptr[3]))
398                         return 0;
399         }
400
401         /*
402          *      check and decrement ttl
403          */
404         if (hdr->hop_limit <= 1) {
405                 /* Force OUTPUT device used as source address */
406                 skb->dev = dst->dev;
407                 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
408                             0, skb->dev);
409                 IP6_INC_STATS_BH(ip6_dst_idev(dst), IPSTATS_MIB_INHDRERRORS);
410
411                 kfree_skb(skb);
412                 return -ETIMEDOUT;
413         }
414
415         /* XXX: idev->cnf.proxy_ndp? */
416         if (ipv6_devconf.proxy_ndp &&
417             pneigh_lookup(&nd_tbl, &hdr->daddr, skb->dev, 0)) {
418                 int proxied = ip6_forward_proxy_check(skb);
419                 if (proxied > 0)
420                         return ip6_input(skb);
421                 else if (proxied < 0) {
422                         IP6_INC_STATS(ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS);
423                         goto drop;
424                 }
425         }
426
427         if (!xfrm6_route_forward(skb)) {
428                 IP6_INC_STATS(ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS);
429                 goto drop;
430         }
431         dst = skb->dst;
432
433         /* IPv6 specs say nothing about it, but it is clear that we cannot
434            send redirects to source routed frames.
435          */
436         if (skb->dev == dst->dev && dst->neighbour && opt->srcrt == 0) {
437                 struct in6_addr *target = NULL;
438                 struct rt6_info *rt;
439                 struct neighbour *n = dst->neighbour;
440
441                 /*
442                  *      incoming and outgoing devices are the same
443                  *      send a redirect.
444                  */
445
446                 rt = (struct rt6_info *) dst;
447                 if ((rt->rt6i_flags & RTF_GATEWAY))
448                         target = (struct in6_addr*)&n->primary_key;
449                 else
450                         target = &hdr->daddr;
451
452                 /* Limit redirects both by destination (here)
453                    and by source (inside ndisc_send_redirect)
454                  */
455                 if (xrlim_allow(dst, 1*HZ))
456                         ndisc_send_redirect(skb, n, target);
457         } else if (ipv6_addr_type(&hdr->saddr)&(IPV6_ADDR_MULTICAST|IPV6_ADDR_LOOPBACK
458                                                 |IPV6_ADDR_LINKLOCAL)) {
459                 /* This check is security critical. */
460                 goto error;
461         }
462
463         if (skb->len > dst_mtu(dst)) {
464                 /* Again, force OUTPUT device used as source address */
465                 skb->dev = dst->dev;
466                 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, dst_mtu(dst), skb->dev);
467                 IP6_INC_STATS_BH(ip6_dst_idev(dst), IPSTATS_MIB_INTOOBIGERRORS);
468                 IP6_INC_STATS_BH(ip6_dst_idev(dst), IPSTATS_MIB_FRAGFAILS);
469                 kfree_skb(skb);
470                 return -EMSGSIZE;
471         }
472
473         if (skb_cow(skb, dst->dev->hard_header_len)) {
474                 IP6_INC_STATS(ip6_dst_idev(dst), IPSTATS_MIB_OUTDISCARDS);
475                 goto drop;
476         }
477
478         hdr = ipv6_hdr(skb);
479
480         /* Mangling hops number delayed to point after skb COW */
481
482         hdr->hop_limit--;
483
484         IP6_INC_STATS_BH(ip6_dst_idev(dst), IPSTATS_MIB_OUTFORWDATAGRAMS);
485         return NF_HOOK(PF_INET6,NF_IP6_FORWARD, skb, skb->dev, dst->dev, ip6_forward_finish);
486
487 error:
488         IP6_INC_STATS_BH(ip6_dst_idev(dst), IPSTATS_MIB_INADDRERRORS);
489 drop:
490         kfree_skb(skb);
491         return -EINVAL;
492 }
493
494 static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from)
495 {
496         to->pkt_type = from->pkt_type;
497         to->priority = from->priority;
498         to->protocol = from->protocol;
499         dst_release(to->dst);
500         to->dst = dst_clone(from->dst);
501         to->dev = from->dev;
502         to->mark = from->mark;
503
504 #ifdef CONFIG_NET_SCHED
505         to->tc_index = from->tc_index;
506 #endif
507 #ifdef CONFIG_NETFILTER
508         /* Connection association is same as pre-frag packet */
509         nf_conntrack_put(to->nfct);
510         to->nfct = from->nfct;
511         nf_conntrack_get(to->nfct);
512         to->nfctinfo = from->nfctinfo;
513 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
514         nf_conntrack_put_reasm(to->nfct_reasm);
515         to->nfct_reasm = from->nfct_reasm;
516         nf_conntrack_get_reasm(to->nfct_reasm);
517 #endif
518 #ifdef CONFIG_BRIDGE_NETFILTER
519         nf_bridge_put(to->nf_bridge);
520         to->nf_bridge = from->nf_bridge;
521         nf_bridge_get(to->nf_bridge);
522 #endif
523 #endif
524         skb_copy_secmark(to, from);
525 }
526
527 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr)
528 {
529         u16 offset = sizeof(struct ipv6hdr);
530         struct ipv6_opt_hdr *exthdr =
531                                 (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
532         unsigned int packet_len = skb->tail - skb_network_header(skb);
533         int found_rhdr = 0;
534         *nexthdr = &ipv6_hdr(skb)->nexthdr;
535
536         while (offset + 1 <= packet_len) {
537
538                 switch (**nexthdr) {
539
540                 case NEXTHDR_HOP:
541                         break;
542                 case NEXTHDR_ROUTING:
543                         found_rhdr = 1;
544                         break;
545                 case NEXTHDR_DEST:
546 #ifdef CONFIG_IPV6_MIP6
547                         if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
548                                 break;
549 #endif
550                         if (found_rhdr)
551                                 return offset;
552                         break;
553                 default :
554                         return offset;
555                 }
556
557                 offset += ipv6_optlen(exthdr);
558                 *nexthdr = &exthdr->nexthdr;
559                 exthdr = (struct ipv6_opt_hdr *)(skb_network_header(skb) +
560                                                  offset);
561         }
562
563         return offset;
564 }
565 EXPORT_SYMBOL_GPL(ip6_find_1stfragopt);
566
567 static int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *))
568 {
569         struct net_device *dev;
570         struct sk_buff *frag;
571         struct rt6_info *rt = (struct rt6_info*)skb->dst;
572         struct ipv6_pinfo *np = skb->sk ? inet6_sk(skb->sk) : NULL;
573         struct ipv6hdr *tmp_hdr;
574         struct frag_hdr *fh;
575         unsigned int mtu, hlen, left, len;
576         __be32 frag_id = 0;
577         int ptr, offset = 0, err=0;
578         u8 *prevhdr, nexthdr = 0;
579
580         dev = rt->u.dst.dev;
581         hlen = ip6_find_1stfragopt(skb, &prevhdr);
582         nexthdr = *prevhdr;
583
584         mtu = dst_mtu(&rt->u.dst);
585         if (np && np->frag_size < mtu) {
586                 if (np->frag_size)
587                         mtu = np->frag_size;
588         }
589         mtu -= hlen + sizeof(struct frag_hdr);
590
591         if (skb_shinfo(skb)->frag_list) {
592                 int first_len = skb_pagelen(skb);
593
594                 if (first_len - hlen > mtu ||
595                     ((first_len - hlen) & 7) ||
596                     skb_cloned(skb))
597                         goto slow_path;
598
599                 for (frag = skb_shinfo(skb)->frag_list; frag; frag = frag->next) {
600                         /* Correct geometry. */
601                         if (frag->len > mtu ||
602                             ((frag->len & 7) && frag->next) ||
603                             skb_headroom(frag) < hlen)
604                             goto slow_path;
605
606                         /* Partially cloned skb? */
607                         if (skb_shared(frag))
608                                 goto slow_path;
609
610                         BUG_ON(frag->sk);
611                         if (skb->sk) {
612                                 sock_hold(skb->sk);
613                                 frag->sk = skb->sk;
614                                 frag->destructor = sock_wfree;
615                                 skb->truesize -= frag->truesize;
616                         }
617                 }
618
619                 err = 0;
620                 offset = 0;
621                 frag = skb_shinfo(skb)->frag_list;
622                 skb_shinfo(skb)->frag_list = NULL;
623                 /* BUILD HEADER */
624
625                 *prevhdr = NEXTHDR_FRAGMENT;
626                 tmp_hdr = kmemdup(skb_network_header(skb), hlen, GFP_ATOMIC);
627                 if (!tmp_hdr) {
628                         IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_FRAGFAILS);
629                         return -ENOMEM;
630                 }
631
632                 __skb_pull(skb, hlen);
633                 fh = (struct frag_hdr*)__skb_push(skb, sizeof(struct frag_hdr));
634                 __skb_push(skb, hlen);
635                 skb_reset_network_header(skb);
636                 memcpy(skb_network_header(skb), tmp_hdr, hlen);
637
638                 ipv6_select_ident(skb, fh);
639                 fh->nexthdr = nexthdr;
640                 fh->reserved = 0;
641                 fh->frag_off = htons(IP6_MF);
642                 frag_id = fh->identification;
643
644                 first_len = skb_pagelen(skb);
645                 skb->data_len = first_len - skb_headlen(skb);
646                 skb->len = first_len;
647                 ipv6_hdr(skb)->payload_len = htons(first_len -
648                                                    sizeof(struct ipv6hdr));
649
650                 dst_hold(&rt->u.dst);
651
652                 for (;;) {
653                         /* Prepare header of the next frame,
654                          * before previous one went down. */
655                         if (frag) {
656                                 frag->ip_summed = CHECKSUM_NONE;
657                                 skb_reset_transport_header(frag);
658                                 fh = (struct frag_hdr*)__skb_push(frag, sizeof(struct frag_hdr));
659                                 __skb_push(frag, hlen);
660                                 skb_reset_network_header(frag);
661                                 memcpy(skb_network_header(frag), tmp_hdr,
662                                        hlen);
663                                 offset += skb->len - hlen - sizeof(struct frag_hdr);
664                                 fh->nexthdr = nexthdr;
665                                 fh->reserved = 0;
666                                 fh->frag_off = htons(offset);
667                                 if (frag->next != NULL)
668                                         fh->frag_off |= htons(IP6_MF);
669                                 fh->identification = frag_id;
670                                 ipv6_hdr(frag)->payload_len =
671                                                 htons(frag->len -
672                                                       sizeof(struct ipv6hdr));
673                                 ip6_copy_metadata(frag, skb);
674                         }
675
676                         err = output(skb);
677                         if(!err)
678                                 IP6_INC_STATS(ip6_dst_idev(&rt->u.dst), IPSTATS_MIB_FRAGCREATES);
679
680                         if (err || !frag)
681                                 break;
682
683                         skb = frag;
684                         frag = skb->next;
685                         skb->next = NULL;
686                 }
687
688                 kfree(tmp_hdr);
689
690                 if (err == 0) {
691                         IP6_INC_STATS(ip6_dst_idev(&rt->u.dst), IPSTATS_MIB_FRAGOKS);
692                         dst_release(&rt->u.dst);
693                         return 0;
694                 }
695
696                 while (frag) {
697                         skb = frag->next;
698                         kfree_skb(frag);
699                         frag = skb;
700                 }
701
702                 IP6_INC_STATS(ip6_dst_idev(&rt->u.dst), IPSTATS_MIB_FRAGFAILS);
703                 dst_release(&rt->u.dst);
704                 return err;
705         }
706
707 slow_path:
708         left = skb->len - hlen;         /* Space per frame */
709         ptr = hlen;                     /* Where to start from */
710
711         /*
712          *      Fragment the datagram.
713          */
714
715         *prevhdr = NEXTHDR_FRAGMENT;
716
717         /*
718          *      Keep copying data until we run out.
719          */
720         while(left > 0) {
721                 len = left;
722                 /* IF: it doesn't fit, use 'mtu' - the data space left */
723                 if (len > mtu)
724                         len = mtu;
725                 /* IF: we are not sending upto and including the packet end
726                    then align the next start on an eight byte boundary */
727                 if (len < left) {
728                         len &= ~7;
729                 }
730                 /*
731                  *      Allocate buffer.
732                  */
733
734                 if ((frag = alloc_skb(len+hlen+sizeof(struct frag_hdr)+LL_RESERVED_SPACE(rt->u.dst.dev), GFP_ATOMIC)) == NULL) {
735                         NETDEBUG(KERN_INFO "IPv6: frag: no memory for new fragment!\n");
736                         IP6_INC_STATS(ip6_dst_idev(skb->dst),
737                                       IPSTATS_MIB_FRAGFAILS);
738                         err = -ENOMEM;
739                         goto fail;
740                 }
741
742                 /*
743                  *      Set up data on packet
744                  */
745
746                 ip6_copy_metadata(frag, skb);
747                 skb_reserve(frag, LL_RESERVED_SPACE(rt->u.dst.dev));
748                 skb_put(frag, len + hlen + sizeof(struct frag_hdr));
749                 skb_reset_network_header(frag);
750                 fh = (struct frag_hdr *)(skb_network_header(frag) + hlen);
751                 frag->h.raw = frag->nh.raw + hlen + sizeof(struct frag_hdr);
752
753                 /*
754                  *      Charge the memory for the fragment to any owner
755                  *      it might possess
756                  */
757                 if (skb->sk)
758                         skb_set_owner_w(frag, skb->sk);
759
760                 /*
761                  *      Copy the packet header into the new buffer.
762                  */
763                 memcpy(skb_network_header(frag), skb->data, hlen);
764
765                 /*
766                  *      Build fragment header.
767                  */
768                 fh->nexthdr = nexthdr;
769                 fh->reserved = 0;
770                 if (!frag_id) {
771                         ipv6_select_ident(skb, fh);
772                         frag_id = fh->identification;
773                 } else
774                         fh->identification = frag_id;
775
776                 /*
777                  *      Copy a block of the IP datagram.
778                  */
779                 if (skb_copy_bits(skb, ptr, frag->h.raw, len))
780                         BUG();
781                 left -= len;
782
783                 fh->frag_off = htons(offset);
784                 if (left > 0)
785                         fh->frag_off |= htons(IP6_MF);
786                 ipv6_hdr(frag)->payload_len = htons(frag->len -
787                                                     sizeof(struct ipv6hdr));
788
789                 ptr += len;
790                 offset += len;
791
792                 /*
793                  *      Put this fragment into the sending queue.
794                  */
795                 err = output(frag);
796                 if (err)
797                         goto fail;
798
799                 IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_FRAGCREATES);
800         }
801         IP6_INC_STATS(ip6_dst_idev(skb->dst),
802                       IPSTATS_MIB_FRAGOKS);
803         kfree_skb(skb);
804         return err;
805
806 fail:
807         IP6_INC_STATS(ip6_dst_idev(skb->dst),
808                       IPSTATS_MIB_FRAGFAILS);
809         kfree_skb(skb);
810         return err;
811 }
812
813 static inline int ip6_rt_check(struct rt6key *rt_key,
814                                struct in6_addr *fl_addr,
815                                struct in6_addr *addr_cache)
816 {
817         return ((rt_key->plen != 128 || !ipv6_addr_equal(fl_addr, &rt_key->addr)) &&
818                 (addr_cache == NULL || !ipv6_addr_equal(fl_addr, addr_cache)));
819 }
820
821 static struct dst_entry *ip6_sk_dst_check(struct sock *sk,
822                                           struct dst_entry *dst,
823                                           struct flowi *fl)
824 {
825         struct ipv6_pinfo *np = inet6_sk(sk);
826         struct rt6_info *rt = (struct rt6_info *)dst;
827
828         if (!dst)
829                 goto out;
830
831         /* Yes, checking route validity in not connected
832          * case is not very simple. Take into account,
833          * that we do not support routing by source, TOS,
834          * and MSG_DONTROUTE            --ANK (980726)
835          *
836          * 1. ip6_rt_check(): If route was host route,
837          *    check that cached destination is current.
838          *    If it is network route, we still may
839          *    check its validity using saved pointer
840          *    to the last used address: daddr_cache.
841          *    We do not want to save whole address now,
842          *    (because main consumer of this service
843          *    is tcp, which has not this problem),
844          *    so that the last trick works only on connected
845          *    sockets.
846          * 2. oif also should be the same.
847          */
848         if (ip6_rt_check(&rt->rt6i_dst, &fl->fl6_dst, np->daddr_cache) ||
849 #ifdef CONFIG_IPV6_SUBTREES
850             ip6_rt_check(&rt->rt6i_src, &fl->fl6_src, np->saddr_cache) ||
851 #endif
852             (fl->oif && fl->oif != dst->dev->ifindex)) {
853                 dst_release(dst);
854                 dst = NULL;
855         }
856
857 out:
858         return dst;
859 }
860
861 static int ip6_dst_lookup_tail(struct sock *sk,
862                                struct dst_entry **dst, struct flowi *fl)
863 {
864         int err;
865
866         if (*dst == NULL)
867                 *dst = ip6_route_output(sk, fl);
868
869         if ((err = (*dst)->error))
870                 goto out_err_release;
871
872         if (ipv6_addr_any(&fl->fl6_src)) {
873                 err = ipv6_get_saddr(*dst, &fl->fl6_dst, &fl->fl6_src);
874                 if (err)
875                         goto out_err_release;
876         }
877
878 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
879                 /*
880                  * Here if the dst entry we've looked up
881                  * has a neighbour entry that is in the INCOMPLETE
882                  * state and the src address from the flow is
883                  * marked as OPTIMISTIC, we release the found
884                  * dst entry and replace it instead with the
885                  * dst entry of the nexthop router
886                  */
887                 if (!((*dst)->neighbour->nud_state & NUD_VALID)) {
888                         struct inet6_ifaddr *ifp;
889                         struct flowi fl_gw;
890                         int redirect;
891
892                         ifp = ipv6_get_ifaddr(&fl->fl6_src, (*dst)->dev, 1);
893
894                         redirect = (ifp && ifp->flags & IFA_F_OPTIMISTIC);
895                         if (ifp)
896                                 in6_ifa_put(ifp);
897
898                         if (redirect) {
899                                 /*
900                                  * We need to get the dst entry for the
901                                  * default router instead
902                                  */
903                                 dst_release(*dst);
904                                 memcpy(&fl_gw, fl, sizeof(struct flowi));
905                                 memset(&fl_gw.fl6_dst, 0, sizeof(struct in6_addr));
906                                 *dst = ip6_route_output(sk, &fl_gw);
907                                 if ((err = (*dst)->error))
908                                         goto out_err_release;
909                         }
910                 }
911 #endif
912
913         return 0;
914
915 out_err_release:
916         dst_release(*dst);
917         *dst = NULL;
918         return err;
919 }
920
921 /**
922  *      ip6_dst_lookup - perform route lookup on flow
923  *      @sk: socket which provides route info
924  *      @dst: pointer to dst_entry * for result
925  *      @fl: flow to lookup
926  *
927  *      This function performs a route lookup on the given flow.
928  *
929  *      It returns zero on success, or a standard errno code on error.
930  */
931 int ip6_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi *fl)
932 {
933         *dst = NULL;
934         return ip6_dst_lookup_tail(sk, dst, fl);
935 }
936 EXPORT_SYMBOL_GPL(ip6_dst_lookup);
937
938 /**
939  *      ip6_sk_dst_lookup - perform socket cached route lookup on flow
940  *      @sk: socket which provides the dst cache and route info
941  *      @dst: pointer to dst_entry * for result
942  *      @fl: flow to lookup
943  *
944  *      This function performs a route lookup on the given flow with the
945  *      possibility of using the cached route in the socket if it is valid.
946  *      It will take the socket dst lock when operating on the dst cache.
947  *      As a result, this function can only be used in process context.
948  *
949  *      It returns zero on success, or a standard errno code on error.
950  */
951 int ip6_sk_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi *fl)
952 {
953         *dst = NULL;
954         if (sk) {
955                 *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie);
956                 *dst = ip6_sk_dst_check(sk, *dst, fl);
957         }
958
959         return ip6_dst_lookup_tail(sk, dst, fl);
960 }
961 EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup);
962
963 static inline int ip6_ufo_append_data(struct sock *sk,
964                         int getfrag(void *from, char *to, int offset, int len,
965                         int odd, struct sk_buff *skb),
966                         void *from, int length, int hh_len, int fragheaderlen,
967                         int transhdrlen, int mtu,unsigned int flags)
968
969 {
970         struct sk_buff *skb;
971         int err;
972
973         /* There is support for UDP large send offload by network
974          * device, so create one single skb packet containing complete
975          * udp datagram
976          */
977         if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) {
978                 skb = sock_alloc_send_skb(sk,
979                         hh_len + fragheaderlen + transhdrlen + 20,
980                         (flags & MSG_DONTWAIT), &err);
981                 if (skb == NULL)
982                         return -ENOMEM;
983
984                 /* reserve space for Hardware header */
985                 skb_reserve(skb, hh_len);
986
987                 /* create space for UDP/IP header */
988                 skb_put(skb,fragheaderlen + transhdrlen);
989
990                 /* initialize network header pointer */
991                 skb_reset_network_header(skb);
992
993                 /* initialize protocol header pointer */
994                 skb->h.raw = skb->nh.raw + fragheaderlen;
995
996                 skb->ip_summed = CHECKSUM_PARTIAL;
997                 skb->csum = 0;
998                 sk->sk_sndmsg_off = 0;
999         }
1000
1001         err = skb_append_datato_frags(sk,skb, getfrag, from,
1002                                       (length - transhdrlen));
1003         if (!err) {
1004                 struct frag_hdr fhdr;
1005
1006                 /* specify the length of each IP datagram fragment*/
1007                 skb_shinfo(skb)->gso_size = mtu - fragheaderlen -
1008                                             sizeof(struct frag_hdr);
1009                 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
1010                 ipv6_select_ident(skb, &fhdr);
1011                 skb_shinfo(skb)->ip6_frag_id = fhdr.identification;
1012                 __skb_queue_tail(&sk->sk_write_queue, skb);
1013
1014                 return 0;
1015         }
1016         /* There is not enough support do UPD LSO,
1017          * so follow normal path
1018          */
1019         kfree_skb(skb);
1020
1021         return err;
1022 }
1023
1024 int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
1025         int offset, int len, int odd, struct sk_buff *skb),
1026         void *from, int length, int transhdrlen,
1027         int hlimit, int tclass, struct ipv6_txoptions *opt, struct flowi *fl,
1028         struct rt6_info *rt, unsigned int flags)
1029 {
1030         struct inet_sock *inet = inet_sk(sk);
1031         struct ipv6_pinfo *np = inet6_sk(sk);
1032         struct sk_buff *skb;
1033         unsigned int maxfraglen, fragheaderlen;
1034         int exthdrlen;
1035         int hh_len;
1036         int mtu;
1037         int copy;
1038         int err;
1039         int offset = 0;
1040         int csummode = CHECKSUM_NONE;
1041
1042         if (flags&MSG_PROBE)
1043                 return 0;
1044         if (skb_queue_empty(&sk->sk_write_queue)) {
1045                 /*
1046                  * setup for corking
1047                  */
1048                 if (opt) {
1049                         if (np->cork.opt == NULL) {
1050                                 np->cork.opt = kmalloc(opt->tot_len,
1051                                                        sk->sk_allocation);
1052                                 if (unlikely(np->cork.opt == NULL))
1053                                         return -ENOBUFS;
1054                         } else if (np->cork.opt->tot_len < opt->tot_len) {
1055                                 printk(KERN_DEBUG "ip6_append_data: invalid option length\n");
1056                                 return -EINVAL;
1057                         }
1058                         memcpy(np->cork.opt, opt, opt->tot_len);
1059                         inet->cork.flags |= IPCORK_OPT;
1060                         /* need source address above miyazawa*/
1061                 }
1062                 dst_hold(&rt->u.dst);
1063                 np->cork.rt = rt;
1064                 inet->cork.fl = *fl;
1065                 np->cork.hop_limit = hlimit;
1066                 np->cork.tclass = tclass;
1067                 mtu = dst_mtu(rt->u.dst.path);
1068                 if (np->frag_size < mtu) {
1069                         if (np->frag_size)
1070                                 mtu = np->frag_size;
1071                 }
1072                 inet->cork.fragsize = mtu;
1073                 if (dst_allfrag(rt->u.dst.path))
1074                         inet->cork.flags |= IPCORK_ALLFRAG;
1075                 inet->cork.length = 0;
1076                 sk->sk_sndmsg_page = NULL;
1077                 sk->sk_sndmsg_off = 0;
1078                 exthdrlen = rt->u.dst.header_len + (opt ? opt->opt_flen : 0);
1079                 length += exthdrlen;
1080                 transhdrlen += exthdrlen;
1081         } else {
1082                 rt = np->cork.rt;
1083                 fl = &inet->cork.fl;
1084                 if (inet->cork.flags & IPCORK_OPT)
1085                         opt = np->cork.opt;
1086                 transhdrlen = 0;
1087                 exthdrlen = 0;
1088                 mtu = inet->cork.fragsize;
1089         }
1090
1091         hh_len = LL_RESERVED_SPACE(rt->u.dst.dev);
1092
1093         fragheaderlen = sizeof(struct ipv6hdr) + rt->u.dst.nfheader_len + (opt ? opt->opt_nflen : 0);
1094         maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - sizeof(struct frag_hdr);
1095
1096         if (mtu <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN) {
1097                 if (inet->cork.length + length > sizeof(struct ipv6hdr) + IPV6_MAXPLEN - fragheaderlen) {
1098                         ipv6_local_error(sk, EMSGSIZE, fl, mtu-exthdrlen);
1099                         return -EMSGSIZE;
1100                 }
1101         }
1102
1103         /*
1104          * Let's try using as much space as possible.
1105          * Use MTU if total length of the message fits into the MTU.
1106          * Otherwise, we need to reserve fragment header and
1107          * fragment alignment (= 8-15 octects, in total).
1108          *
1109          * Note that we may need to "move" the data from the tail of
1110          * of the buffer to the new fragment when we split
1111          * the message.
1112          *
1113          * FIXME: It may be fragmented into multiple chunks
1114          *        at once if non-fragmentable extension headers
1115          *        are too large.
1116          * --yoshfuji
1117          */
1118
1119         inet->cork.length += length;
1120         if (((length > mtu) && (sk->sk_protocol == IPPROTO_UDP)) &&
1121             (rt->u.dst.dev->features & NETIF_F_UFO)) {
1122
1123                 err = ip6_ufo_append_data(sk, getfrag, from, length, hh_len,
1124                                           fragheaderlen, transhdrlen, mtu,
1125                                           flags);
1126                 if (err)
1127                         goto error;
1128                 return 0;
1129         }
1130
1131         if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL)
1132                 goto alloc_new_skb;
1133
1134         while (length > 0) {
1135                 /* Check if the remaining data fits into current packet. */
1136                 copy = (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len;
1137                 if (copy < length)
1138                         copy = maxfraglen - skb->len;
1139
1140                 if (copy <= 0) {
1141                         char *data;
1142                         unsigned int datalen;
1143                         unsigned int fraglen;
1144                         unsigned int fraggap;
1145                         unsigned int alloclen;
1146                         struct sk_buff *skb_prev;
1147 alloc_new_skb:
1148                         skb_prev = skb;
1149
1150                         /* There's no room in the current skb */
1151                         if (skb_prev)
1152                                 fraggap = skb_prev->len - maxfraglen;
1153                         else
1154                                 fraggap = 0;
1155
1156                         /*
1157                          * If remaining data exceeds the mtu,
1158                          * we know we need more fragment(s).
1159                          */
1160                         datalen = length + fraggap;
1161                         if (datalen > (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen)
1162                                 datalen = maxfraglen - fragheaderlen;
1163
1164                         fraglen = datalen + fragheaderlen;
1165                         if ((flags & MSG_MORE) &&
1166                             !(rt->u.dst.dev->features&NETIF_F_SG))
1167                                 alloclen = mtu;
1168                         else
1169                                 alloclen = datalen + fragheaderlen;
1170
1171                         /*
1172                          * The last fragment gets additional space at tail.
1173                          * Note: we overallocate on fragments with MSG_MODE
1174                          * because we have no idea if we're the last one.
1175                          */
1176                         if (datalen == length + fraggap)
1177                                 alloclen += rt->u.dst.trailer_len;
1178
1179                         /*
1180                          * We just reserve space for fragment header.
1181                          * Note: this may be overallocation if the message
1182                          * (without MSG_MORE) fits into the MTU.
1183                          */
1184                         alloclen += sizeof(struct frag_hdr);
1185
1186                         if (transhdrlen) {
1187                                 skb = sock_alloc_send_skb(sk,
1188                                                 alloclen + hh_len,
1189                                                 (flags & MSG_DONTWAIT), &err);
1190                         } else {
1191                                 skb = NULL;
1192                                 if (atomic_read(&sk->sk_wmem_alloc) <=
1193                                     2 * sk->sk_sndbuf)
1194                                         skb = sock_wmalloc(sk,
1195                                                            alloclen + hh_len, 1,
1196                                                            sk->sk_allocation);
1197                                 if (unlikely(skb == NULL))
1198                                         err = -ENOBUFS;
1199                         }
1200                         if (skb == NULL)
1201                                 goto error;
1202                         /*
1203                          *      Fill in the control structures
1204                          */
1205                         skb->ip_summed = csummode;
1206                         skb->csum = 0;
1207                         /* reserve for fragmentation */
1208                         skb_reserve(skb, hh_len+sizeof(struct frag_hdr));
1209
1210                         /*
1211                          *      Find where to start putting bytes
1212                          */
1213                         data = skb_put(skb, fraglen);
1214                         skb_set_network_header(skb, exthdrlen);
1215                         data += fragheaderlen;
1216                         skb->h.raw = skb->nh.raw + fragheaderlen;
1217
1218                         if (fraggap) {
1219                                 skb->csum = skb_copy_and_csum_bits(
1220                                         skb_prev, maxfraglen,
1221                                         data + transhdrlen, fraggap, 0);
1222                                 skb_prev->csum = csum_sub(skb_prev->csum,
1223                                                           skb->csum);
1224                                 data += fraggap;
1225                                 pskb_trim_unique(skb_prev, maxfraglen);
1226                         }
1227                         copy = datalen - transhdrlen - fraggap;
1228                         if (copy < 0) {
1229                                 err = -EINVAL;
1230                                 kfree_skb(skb);
1231                                 goto error;
1232                         } else if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) {
1233                                 err = -EFAULT;
1234                                 kfree_skb(skb);
1235                                 goto error;
1236                         }
1237
1238                         offset += copy;
1239                         length -= datalen - fraggap;
1240                         transhdrlen = 0;
1241                         exthdrlen = 0;
1242                         csummode = CHECKSUM_NONE;
1243
1244                         /*
1245                          * Put the packet on the pending queue
1246                          */
1247                         __skb_queue_tail(&sk->sk_write_queue, skb);
1248                         continue;
1249                 }
1250
1251                 if (copy > length)
1252                         copy = length;
1253
1254                 if (!(rt->u.dst.dev->features&NETIF_F_SG)) {
1255                         unsigned int off;
1256
1257                         off = skb->len;
1258                         if (getfrag(from, skb_put(skb, copy),
1259                                                 offset, copy, off, skb) < 0) {
1260                                 __skb_trim(skb, off);
1261                                 err = -EFAULT;
1262                                 goto error;
1263                         }
1264                 } else {
1265                         int i = skb_shinfo(skb)->nr_frags;
1266                         skb_frag_t *frag = &skb_shinfo(skb)->frags[i-1];
1267                         struct page *page = sk->sk_sndmsg_page;
1268                         int off = sk->sk_sndmsg_off;
1269                         unsigned int left;
1270
1271                         if (page && (left = PAGE_SIZE - off) > 0) {
1272                                 if (copy >= left)
1273                                         copy = left;
1274                                 if (page != frag->page) {
1275                                         if (i == MAX_SKB_FRAGS) {
1276                                                 err = -EMSGSIZE;
1277                                                 goto error;
1278                                         }
1279                                         get_page(page);
1280                                         skb_fill_page_desc(skb, i, page, sk->sk_sndmsg_off, 0);
1281                                         frag = &skb_shinfo(skb)->frags[i];
1282                                 }
1283                         } else if(i < MAX_SKB_FRAGS) {
1284                                 if (copy > PAGE_SIZE)
1285                                         copy = PAGE_SIZE;
1286                                 page = alloc_pages(sk->sk_allocation, 0);
1287                                 if (page == NULL) {
1288                                         err = -ENOMEM;
1289                                         goto error;
1290                                 }
1291                                 sk->sk_sndmsg_page = page;
1292                                 sk->sk_sndmsg_off = 0;
1293
1294                                 skb_fill_page_desc(skb, i, page, 0, 0);
1295                                 frag = &skb_shinfo(skb)->frags[i];
1296                                 skb->truesize += PAGE_SIZE;
1297                                 atomic_add(PAGE_SIZE, &sk->sk_wmem_alloc);
1298                         } else {
1299                                 err = -EMSGSIZE;
1300                                 goto error;
1301                         }
1302                         if (getfrag(from, page_address(frag->page)+frag->page_offset+frag->size, offset, copy, skb->len, skb) < 0) {
1303                                 err = -EFAULT;
1304                                 goto error;
1305                         }
1306                         sk->sk_sndmsg_off += copy;
1307                         frag->size += copy;
1308                         skb->len += copy;
1309                         skb->data_len += copy;
1310                 }
1311                 offset += copy;
1312                 length -= copy;
1313         }
1314         return 0;
1315 error:
1316         inet->cork.length -= length;
1317         IP6_INC_STATS(rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS);
1318         return err;
1319 }
1320
1321 int ip6_push_pending_frames(struct sock *sk)
1322 {
1323         struct sk_buff *skb, *tmp_skb;
1324         struct sk_buff **tail_skb;
1325         struct in6_addr final_dst_buf, *final_dst = &final_dst_buf;
1326         struct inet_sock *inet = inet_sk(sk);
1327         struct ipv6_pinfo *np = inet6_sk(sk);
1328         struct ipv6hdr *hdr;
1329         struct ipv6_txoptions *opt = np->cork.opt;
1330         struct rt6_info *rt = np->cork.rt;
1331         struct flowi *fl = &inet->cork.fl;
1332         unsigned char proto = fl->proto;
1333         int err = 0;
1334
1335         if ((skb = __skb_dequeue(&sk->sk_write_queue)) == NULL)
1336                 goto out;
1337         tail_skb = &(skb_shinfo(skb)->frag_list);
1338
1339         /* move skb->data to ip header from ext header */
1340         if (skb->data < skb_network_header(skb))
1341                 __skb_pull(skb, skb_network_offset(skb));
1342         while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) {
1343                 __skb_pull(tmp_skb, skb->h.raw - skb->nh.raw);
1344                 *tail_skb = tmp_skb;
1345                 tail_skb = &(tmp_skb->next);
1346                 skb->len += tmp_skb->len;
1347                 skb->data_len += tmp_skb->len;
1348                 skb->truesize += tmp_skb->truesize;
1349                 __sock_put(tmp_skb->sk);
1350                 tmp_skb->destructor = NULL;
1351                 tmp_skb->sk = NULL;
1352         }
1353
1354         ipv6_addr_copy(final_dst, &fl->fl6_dst);
1355         __skb_pull(skb, skb->h.raw - skb->nh.raw);
1356         if (opt && opt->opt_flen)
1357                 ipv6_push_frag_opts(skb, opt, &proto);
1358         if (opt && opt->opt_nflen)
1359                 ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst);
1360
1361         skb_push(skb, sizeof(struct ipv6hdr));
1362         skb_reset_network_header(skb);
1363         hdr = ipv6_hdr(skb);
1364
1365         *(__be32*)hdr = fl->fl6_flowlabel |
1366                      htonl(0x60000000 | ((int)np->cork.tclass << 20));
1367
1368         if (skb->len <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN)
1369                 hdr->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
1370         else
1371                 hdr->payload_len = 0;
1372         hdr->hop_limit = np->cork.hop_limit;
1373         hdr->nexthdr = proto;
1374         ipv6_addr_copy(&hdr->saddr, &fl->fl6_src);
1375         ipv6_addr_copy(&hdr->daddr, final_dst);
1376
1377         skb->priority = sk->sk_priority;
1378
1379         skb->dst = dst_clone(&rt->u.dst);
1380         IP6_INC_STATS(rt->rt6i_idev, IPSTATS_MIB_OUTREQUESTS);
1381         err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, skb->dst->dev, dst_output);
1382         if (err) {
1383                 if (err > 0)
1384                         err = np->recverr ? net_xmit_errno(err) : 0;
1385                 if (err)
1386                         goto error;
1387         }
1388
1389 out:
1390         inet->cork.flags &= ~IPCORK_OPT;
1391         kfree(np->cork.opt);
1392         np->cork.opt = NULL;
1393         if (np->cork.rt) {
1394                 dst_release(&np->cork.rt->u.dst);
1395                 np->cork.rt = NULL;
1396                 inet->cork.flags &= ~IPCORK_ALLFRAG;
1397         }
1398         memset(&inet->cork.fl, 0, sizeof(inet->cork.fl));
1399         return err;
1400 error:
1401         goto out;
1402 }
1403
1404 void ip6_flush_pending_frames(struct sock *sk)
1405 {
1406         struct inet_sock *inet = inet_sk(sk);
1407         struct ipv6_pinfo *np = inet6_sk(sk);
1408         struct sk_buff *skb;
1409
1410         while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) {
1411                 IP6_INC_STATS(ip6_dst_idev(skb->dst),
1412                               IPSTATS_MIB_OUTDISCARDS);
1413                 kfree_skb(skb);
1414         }
1415
1416         inet->cork.flags &= ~IPCORK_OPT;
1417
1418         kfree(np->cork.opt);
1419         np->cork.opt = NULL;
1420         if (np->cork.rt) {
1421                 dst_release(&np->cork.rt->u.dst);
1422                 np->cork.rt = NULL;
1423                 inet->cork.flags &= ~IPCORK_ALLFRAG;
1424         }
1425         memset(&inet->cork.fl, 0, sizeof(inet->cork.fl));
1426 }