[IPV6]: SNMPv2 "ipv6IfStatsInHdrErrors" counter error
[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 inline int ip6_forward_finish(struct sk_buff *skb)
312 {
313         return dst_output(skb);
314 }
315
316 int ip6_forward(struct sk_buff *skb)
317 {
318         struct dst_entry *dst = skb->dst;
319         struct ipv6hdr *hdr = skb->nh.ipv6h;
320         struct inet6_skb_parm *opt = IP6CB(skb);
321         
322         if (ipv6_devconf.forwarding == 0)
323                 goto error;
324
325         if (!xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) {
326                 IP6_INC_STATS(IPSTATS_MIB_INDISCARDS);
327                 goto drop;
328         }
329
330         skb->ip_summed = CHECKSUM_NONE;
331
332         /*
333          *      We DO NOT make any processing on
334          *      RA packets, pushing them to user level AS IS
335          *      without ane WARRANTY that application will be able
336          *      to interpret them. The reason is that we
337          *      cannot make anything clever here.
338          *
339          *      We are not end-node, so that if packet contains
340          *      AH/ESP, we cannot make anything.
341          *      Defragmentation also would be mistake, RA packets
342          *      cannot be fragmented, because there is no warranty
343          *      that different fragments will go along one path. --ANK
344          */
345         if (opt->ra) {
346                 u8 *ptr = skb->nh.raw + opt->ra;
347                 if (ip6_call_ra_chain(skb, (ptr[2]<<8) + ptr[3]))
348                         return 0;
349         }
350
351         /*
352          *      check and decrement ttl
353          */
354         if (hdr->hop_limit <= 1) {
355                 /* Force OUTPUT device used as source address */
356                 skb->dev = dst->dev;
357                 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
358                             0, skb->dev);
359                 IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
360
361                 kfree_skb(skb);
362                 return -ETIMEDOUT;
363         }
364
365         if (!xfrm6_route_forward(skb)) {
366                 IP6_INC_STATS(IPSTATS_MIB_INDISCARDS);
367                 goto drop;
368         }
369         dst = skb->dst;
370
371         /* IPv6 specs say nothing about it, but it is clear that we cannot
372            send redirects to source routed frames.
373          */
374         if (skb->dev == dst->dev && dst->neighbour && opt->srcrt == 0) {
375                 struct in6_addr *target = NULL;
376                 struct rt6_info *rt;
377                 struct neighbour *n = dst->neighbour;
378
379                 /*
380                  *      incoming and outgoing devices are the same
381                  *      send a redirect.
382                  */
383
384                 rt = (struct rt6_info *) dst;
385                 if ((rt->rt6i_flags & RTF_GATEWAY))
386                         target = (struct in6_addr*)&n->primary_key;
387                 else
388                         target = &hdr->daddr;
389
390                 /* Limit redirects both by destination (here)
391                    and by source (inside ndisc_send_redirect)
392                  */
393                 if (xrlim_allow(dst, 1*HZ))
394                         ndisc_send_redirect(skb, n, target);
395         } else if (ipv6_addr_type(&hdr->saddr)&(IPV6_ADDR_MULTICAST|IPV6_ADDR_LOOPBACK
396                                                 |IPV6_ADDR_LINKLOCAL)) {
397                 /* This check is security critical. */
398                 goto error;
399         }
400
401         if (skb->len > dst_mtu(dst)) {
402                 /* Again, force OUTPUT device used as source address */
403                 skb->dev = dst->dev;
404                 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, dst_mtu(dst), skb->dev);
405                 IP6_INC_STATS_BH(IPSTATS_MIB_INTOOBIGERRORS);
406                 IP6_INC_STATS_BH(IPSTATS_MIB_FRAGFAILS);
407                 kfree_skb(skb);
408                 return -EMSGSIZE;
409         }
410
411         if (skb_cow(skb, dst->dev->hard_header_len)) {
412                 IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
413                 goto drop;
414         }
415
416         hdr = skb->nh.ipv6h;
417
418         /* Mangling hops number delayed to point after skb COW */
419  
420         hdr->hop_limit--;
421
422         IP6_INC_STATS_BH(IPSTATS_MIB_OUTFORWDATAGRAMS);
423         return NF_HOOK(PF_INET6,NF_IP6_FORWARD, skb, skb->dev, dst->dev, ip6_forward_finish);
424
425 error:
426         IP6_INC_STATS_BH(IPSTATS_MIB_INADDRERRORS);
427 drop:
428         kfree_skb(skb);
429         return -EINVAL;
430 }
431
432 static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from)
433 {
434         to->pkt_type = from->pkt_type;
435         to->priority = from->priority;
436         to->protocol = from->protocol;
437         dst_release(to->dst);
438         to->dst = dst_clone(from->dst);
439         to->dev = from->dev;
440
441 #ifdef CONFIG_NET_SCHED
442         to->tc_index = from->tc_index;
443 #endif
444 #ifdef CONFIG_NETFILTER
445         to->nfmark = from->nfmark;
446         /* Connection association is same as pre-frag packet */
447         nf_conntrack_put(to->nfct);
448         to->nfct = from->nfct;
449         nf_conntrack_get(to->nfct);
450         to->nfctinfo = from->nfctinfo;
451 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
452         nf_conntrack_put_reasm(to->nfct_reasm);
453         to->nfct_reasm = from->nfct_reasm;
454         nf_conntrack_get_reasm(to->nfct_reasm);
455 #endif
456 #ifdef CONFIG_BRIDGE_NETFILTER
457         nf_bridge_put(to->nf_bridge);
458         to->nf_bridge = from->nf_bridge;
459         nf_bridge_get(to->nf_bridge);
460 #endif
461 #endif
462         skb_copy_secmark(to, from);
463 }
464
465 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr)
466 {
467         u16 offset = sizeof(struct ipv6hdr);
468         struct ipv6_opt_hdr *exthdr = (struct ipv6_opt_hdr*)(skb->nh.ipv6h + 1);
469         unsigned int packet_len = skb->tail - skb->nh.raw;
470         int found_rhdr = 0;
471         *nexthdr = &skb->nh.ipv6h->nexthdr;
472
473         while (offset + 1 <= packet_len) {
474
475                 switch (**nexthdr) {
476
477                 case NEXTHDR_HOP:
478                 case NEXTHDR_ROUTING:
479                 case NEXTHDR_DEST:
480                         if (**nexthdr == NEXTHDR_ROUTING) found_rhdr = 1;
481                         if (**nexthdr == NEXTHDR_DEST && found_rhdr) return offset;
482                         offset += ipv6_optlen(exthdr);
483                         *nexthdr = &exthdr->nexthdr;
484                         exthdr = (struct ipv6_opt_hdr*)(skb->nh.raw + offset);
485                         break;
486                 default :
487                         return offset;
488                 }
489         }
490
491         return offset;
492 }
493 EXPORT_SYMBOL_GPL(ip6_find_1stfragopt);
494
495 static int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *))
496 {
497         struct net_device *dev;
498         struct sk_buff *frag;
499         struct rt6_info *rt = (struct rt6_info*)skb->dst;
500         struct ipv6_pinfo *np = skb->sk ? inet6_sk(skb->sk) : NULL;
501         struct ipv6hdr *tmp_hdr;
502         struct frag_hdr *fh;
503         unsigned int mtu, hlen, left, len;
504         u32 frag_id = 0;
505         int ptr, offset = 0, err=0;
506         u8 *prevhdr, nexthdr = 0;
507
508         dev = rt->u.dst.dev;
509         hlen = ip6_find_1stfragopt(skb, &prevhdr);
510         nexthdr = *prevhdr;
511
512         mtu = dst_mtu(&rt->u.dst);
513         if (np && np->frag_size < mtu) {
514                 if (np->frag_size)
515                         mtu = np->frag_size;
516         }
517         mtu -= hlen + sizeof(struct frag_hdr);
518
519         if (skb_shinfo(skb)->frag_list) {
520                 int first_len = skb_pagelen(skb);
521
522                 if (first_len - hlen > mtu ||
523                     ((first_len - hlen) & 7) ||
524                     skb_cloned(skb))
525                         goto slow_path;
526
527                 for (frag = skb_shinfo(skb)->frag_list; frag; frag = frag->next) {
528                         /* Correct geometry. */
529                         if (frag->len > mtu ||
530                             ((frag->len & 7) && frag->next) ||
531                             skb_headroom(frag) < hlen)
532                             goto slow_path;
533
534                         /* Partially cloned skb? */
535                         if (skb_shared(frag))
536                                 goto slow_path;
537
538                         BUG_ON(frag->sk);
539                         if (skb->sk) {
540                                 sock_hold(skb->sk);
541                                 frag->sk = skb->sk;
542                                 frag->destructor = sock_wfree;
543                                 skb->truesize -= frag->truesize;
544                         }
545                 }
546
547                 err = 0;
548                 offset = 0;
549                 frag = skb_shinfo(skb)->frag_list;
550                 skb_shinfo(skb)->frag_list = NULL;
551                 /* BUILD HEADER */
552
553                 tmp_hdr = kmalloc(hlen, GFP_ATOMIC);
554                 if (!tmp_hdr) {
555                         IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
556                         return -ENOMEM;
557                 }
558
559                 *prevhdr = NEXTHDR_FRAGMENT;
560                 memcpy(tmp_hdr, skb->nh.raw, hlen);
561                 __skb_pull(skb, hlen);
562                 fh = (struct frag_hdr*)__skb_push(skb, sizeof(struct frag_hdr));
563                 skb->nh.raw = __skb_push(skb, hlen);
564                 memcpy(skb->nh.raw, tmp_hdr, hlen);
565
566                 ipv6_select_ident(skb, fh);
567                 fh->nexthdr = nexthdr;
568                 fh->reserved = 0;
569                 fh->frag_off = htons(IP6_MF);
570                 frag_id = fh->identification;
571
572                 first_len = skb_pagelen(skb);
573                 skb->data_len = first_len - skb_headlen(skb);
574                 skb->len = first_len;
575                 skb->nh.ipv6h->payload_len = htons(first_len - sizeof(struct ipv6hdr));
576  
577
578                 for (;;) {
579                         /* Prepare header of the next frame,
580                          * before previous one went down. */
581                         if (frag) {
582                                 frag->ip_summed = CHECKSUM_NONE;
583                                 frag->h.raw = frag->data;
584                                 fh = (struct frag_hdr*)__skb_push(frag, sizeof(struct frag_hdr));
585                                 frag->nh.raw = __skb_push(frag, hlen);
586                                 memcpy(frag->nh.raw, tmp_hdr, hlen);
587                                 offset += skb->len - hlen - sizeof(struct frag_hdr);
588                                 fh->nexthdr = nexthdr;
589                                 fh->reserved = 0;
590                                 fh->frag_off = htons(offset);
591                                 if (frag->next != NULL)
592                                         fh->frag_off |= htons(IP6_MF);
593                                 fh->identification = frag_id;
594                                 frag->nh.ipv6h->payload_len = htons(frag->len - sizeof(struct ipv6hdr));
595                                 ip6_copy_metadata(frag, skb);
596                         }
597                         
598                         err = output(skb);
599                         if (err || !frag)
600                                 break;
601
602                         skb = frag;
603                         frag = skb->next;
604                         skb->next = NULL;
605                 }
606
607                 kfree(tmp_hdr);
608
609                 if (err == 0) {
610                         IP6_INC_STATS(IPSTATS_MIB_FRAGOKS);
611                         return 0;
612                 }
613
614                 while (frag) {
615                         skb = frag->next;
616                         kfree_skb(frag);
617                         frag = skb;
618                 }
619
620                 IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
621                 return err;
622         }
623
624 slow_path:
625         left = skb->len - hlen;         /* Space per frame */
626         ptr = hlen;                     /* Where to start from */
627
628         /*
629          *      Fragment the datagram.
630          */
631
632         *prevhdr = NEXTHDR_FRAGMENT;
633
634         /*
635          *      Keep copying data until we run out.
636          */
637         while(left > 0) {
638                 len = left;
639                 /* IF: it doesn't fit, use 'mtu' - the data space left */
640                 if (len > mtu)
641                         len = mtu;
642                 /* IF: we are not sending upto and including the packet end
643                    then align the next start on an eight byte boundary */
644                 if (len < left) {
645                         len &= ~7;
646                 }
647                 /*
648                  *      Allocate buffer.
649                  */
650
651                 if ((frag = alloc_skb(len+hlen+sizeof(struct frag_hdr)+LL_RESERVED_SPACE(rt->u.dst.dev), GFP_ATOMIC)) == NULL) {
652                         NETDEBUG(KERN_INFO "IPv6: frag: no memory for new fragment!\n");
653                         IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
654                         err = -ENOMEM;
655                         goto fail;
656                 }
657
658                 /*
659                  *      Set up data on packet
660                  */
661
662                 ip6_copy_metadata(frag, skb);
663                 skb_reserve(frag, LL_RESERVED_SPACE(rt->u.dst.dev));
664                 skb_put(frag, len + hlen + sizeof(struct frag_hdr));
665                 frag->nh.raw = frag->data;
666                 fh = (struct frag_hdr*)(frag->data + hlen);
667                 frag->h.raw = frag->data + hlen + sizeof(struct frag_hdr);
668
669                 /*
670                  *      Charge the memory for the fragment to any owner
671                  *      it might possess
672                  */
673                 if (skb->sk)
674                         skb_set_owner_w(frag, skb->sk);
675
676                 /*
677                  *      Copy the packet header into the new buffer.
678                  */
679                 memcpy(frag->nh.raw, skb->data, hlen);
680
681                 /*
682                  *      Build fragment header.
683                  */
684                 fh->nexthdr = nexthdr;
685                 fh->reserved = 0;
686                 if (!frag_id) {
687                         ipv6_select_ident(skb, fh);
688                         frag_id = fh->identification;
689                 } else
690                         fh->identification = frag_id;
691
692                 /*
693                  *      Copy a block of the IP datagram.
694                  */
695                 if (skb_copy_bits(skb, ptr, frag->h.raw, len))
696                         BUG();
697                 left -= len;
698
699                 fh->frag_off = htons(offset);
700                 if (left > 0)
701                         fh->frag_off |= htons(IP6_MF);
702                 frag->nh.ipv6h->payload_len = htons(frag->len - sizeof(struct ipv6hdr));
703
704                 ptr += len;
705                 offset += len;
706
707                 /*
708                  *      Put this fragment into the sending queue.
709                  */
710
711                 IP6_INC_STATS(IPSTATS_MIB_FRAGCREATES);
712
713                 err = output(frag);
714                 if (err)
715                         goto fail;
716         }
717         kfree_skb(skb);
718         IP6_INC_STATS(IPSTATS_MIB_FRAGOKS);
719         return err;
720
721 fail:
722         kfree_skb(skb); 
723         IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
724         return err;
725 }
726
727 static struct dst_entry *ip6_sk_dst_check(struct sock *sk,
728                                           struct dst_entry *dst,
729                                           struct flowi *fl)
730 {
731         struct ipv6_pinfo *np = inet6_sk(sk);
732         struct rt6_info *rt = (struct rt6_info *)dst;
733
734         if (!dst)
735                 goto out;
736
737         /* Yes, checking route validity in not connected
738          * case is not very simple. Take into account,
739          * that we do not support routing by source, TOS,
740          * and MSG_DONTROUTE            --ANK (980726)
741          *
742          * 1. If route was host route, check that
743          *    cached destination is current.
744          *    If it is network route, we still may
745          *    check its validity using saved pointer
746          *    to the last used address: daddr_cache.
747          *    We do not want to save whole address now,
748          *    (because main consumer of this service
749          *    is tcp, which has not this problem),
750          *    so that the last trick works only on connected
751          *    sockets.
752          * 2. oif also should be the same.
753          */
754         if (((rt->rt6i_dst.plen != 128 ||
755               !ipv6_addr_equal(&fl->fl6_dst, &rt->rt6i_dst.addr))
756              && (np->daddr_cache == NULL ||
757                  !ipv6_addr_equal(&fl->fl6_dst, np->daddr_cache)))
758             || (fl->oif && fl->oif != dst->dev->ifindex)) {
759                 dst_release(dst);
760                 dst = NULL;
761         }
762
763 out:
764         return dst;
765 }
766
767 static int ip6_dst_lookup_tail(struct sock *sk,
768                                struct dst_entry **dst, struct flowi *fl)
769 {
770         int err;
771
772         if (*dst == NULL)
773                 *dst = ip6_route_output(sk, fl);
774
775         if ((err = (*dst)->error))
776                 goto out_err_release;
777
778         if (ipv6_addr_any(&fl->fl6_src)) {
779                 err = ipv6_get_saddr(*dst, &fl->fl6_dst, &fl->fl6_src);
780                 if (err)
781                         goto out_err_release;
782         }
783
784         return 0;
785
786 out_err_release:
787         dst_release(*dst);
788         *dst = NULL;
789         return err;
790 }
791
792 /**
793  *      ip6_dst_lookup - perform route lookup on flow
794  *      @sk: socket which provides route info
795  *      @dst: pointer to dst_entry * for result
796  *      @fl: flow to lookup
797  *
798  *      This function performs a route lookup on the given flow.
799  *
800  *      It returns zero on success, or a standard errno code on error.
801  */
802 int ip6_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi *fl)
803 {
804         *dst = NULL;
805         return ip6_dst_lookup_tail(sk, dst, fl);
806 }
807 EXPORT_SYMBOL_GPL(ip6_dst_lookup);
808
809 /**
810  *      ip6_sk_dst_lookup - perform socket cached route lookup on flow
811  *      @sk: socket which provides the dst cache and route info
812  *      @dst: pointer to dst_entry * for result
813  *      @fl: flow to lookup
814  *
815  *      This function performs a route lookup on the given flow with the
816  *      possibility of using the cached route in the socket if it is valid.
817  *      It will take the socket dst lock when operating on the dst cache.
818  *      As a result, this function can only be used in process context.
819  *
820  *      It returns zero on success, or a standard errno code on error.
821  */
822 int ip6_sk_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi *fl)
823 {
824         *dst = NULL;
825         if (sk) {
826                 *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie);
827                 *dst = ip6_sk_dst_check(sk, *dst, fl);
828         }
829
830         return ip6_dst_lookup_tail(sk, dst, fl);
831 }
832 EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup);
833
834 static inline int ip6_ufo_append_data(struct sock *sk,
835                         int getfrag(void *from, char *to, int offset, int len,
836                         int odd, struct sk_buff *skb),
837                         void *from, int length, int hh_len, int fragheaderlen,
838                         int transhdrlen, int mtu,unsigned int flags)
839
840 {
841         struct sk_buff *skb;
842         int err;
843
844         /* There is support for UDP large send offload by network
845          * device, so create one single skb packet containing complete
846          * udp datagram
847          */
848         if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) {
849                 skb = sock_alloc_send_skb(sk,
850                         hh_len + fragheaderlen + transhdrlen + 20,
851                         (flags & MSG_DONTWAIT), &err);
852                 if (skb == NULL)
853                         return -ENOMEM;
854
855                 /* reserve space for Hardware header */
856                 skb_reserve(skb, hh_len);
857
858                 /* create space for UDP/IP header */
859                 skb_put(skb,fragheaderlen + transhdrlen);
860
861                 /* initialize network header pointer */
862                 skb->nh.raw = skb->data;
863
864                 /* initialize protocol header pointer */
865                 skb->h.raw = skb->data + fragheaderlen;
866
867                 skb->ip_summed = CHECKSUM_HW;
868                 skb->csum = 0;
869                 sk->sk_sndmsg_off = 0;
870         }
871
872         err = skb_append_datato_frags(sk,skb, getfrag, from,
873                                       (length - transhdrlen));
874         if (!err) {
875                 struct frag_hdr fhdr;
876
877                 /* specify the length of each IP datagram fragment*/
878                 skb_shinfo(skb)->gso_size = mtu - fragheaderlen - 
879                                             sizeof(struct frag_hdr);
880                 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
881                 ipv6_select_ident(skb, &fhdr);
882                 skb_shinfo(skb)->ip6_frag_id = fhdr.identification;
883                 __skb_queue_tail(&sk->sk_write_queue, skb);
884
885                 return 0;
886         }
887         /* There is not enough support do UPD LSO,
888          * so follow normal path
889          */
890         kfree_skb(skb);
891
892         return err;
893 }
894
895 int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
896         int offset, int len, int odd, struct sk_buff *skb),
897         void *from, int length, int transhdrlen,
898         int hlimit, int tclass, struct ipv6_txoptions *opt, struct flowi *fl,
899         struct rt6_info *rt, unsigned int flags)
900 {
901         struct inet_sock *inet = inet_sk(sk);
902         struct ipv6_pinfo *np = inet6_sk(sk);
903         struct sk_buff *skb;
904         unsigned int maxfraglen, fragheaderlen;
905         int exthdrlen;
906         int hh_len;
907         int mtu;
908         int copy;
909         int err;
910         int offset = 0;
911         int csummode = CHECKSUM_NONE;
912
913         if (flags&MSG_PROBE)
914                 return 0;
915         if (skb_queue_empty(&sk->sk_write_queue)) {
916                 /*
917                  * setup for corking
918                  */
919                 if (opt) {
920                         if (np->cork.opt == NULL) {
921                                 np->cork.opt = kmalloc(opt->tot_len,
922                                                        sk->sk_allocation);
923                                 if (unlikely(np->cork.opt == NULL))
924                                         return -ENOBUFS;
925                         } else if (np->cork.opt->tot_len < opt->tot_len) {
926                                 printk(KERN_DEBUG "ip6_append_data: invalid option length\n");
927                                 return -EINVAL;
928                         }
929                         memcpy(np->cork.opt, opt, opt->tot_len);
930                         inet->cork.flags |= IPCORK_OPT;
931                         /* need source address above miyazawa*/
932                 }
933                 dst_hold(&rt->u.dst);
934                 np->cork.rt = rt;
935                 inet->cork.fl = *fl;
936                 np->cork.hop_limit = hlimit;
937                 np->cork.tclass = tclass;
938                 mtu = dst_mtu(rt->u.dst.path);
939                 if (np->frag_size < mtu) {
940                         if (np->frag_size)
941                                 mtu = np->frag_size;
942                 }
943                 inet->cork.fragsize = mtu;
944                 if (dst_allfrag(rt->u.dst.path))
945                         inet->cork.flags |= IPCORK_ALLFRAG;
946                 inet->cork.length = 0;
947                 sk->sk_sndmsg_page = NULL;
948                 sk->sk_sndmsg_off = 0;
949                 exthdrlen = rt->u.dst.header_len + (opt ? opt->opt_flen : 0);
950                 length += exthdrlen;
951                 transhdrlen += exthdrlen;
952         } else {
953                 rt = np->cork.rt;
954                 fl = &inet->cork.fl;
955                 if (inet->cork.flags & IPCORK_OPT)
956                         opt = np->cork.opt;
957                 transhdrlen = 0;
958                 exthdrlen = 0;
959                 mtu = inet->cork.fragsize;
960         }
961
962         hh_len = LL_RESERVED_SPACE(rt->u.dst.dev);
963
964         fragheaderlen = sizeof(struct ipv6hdr) + (opt ? opt->opt_nflen : 0);
965         maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - sizeof(struct frag_hdr);
966
967         if (mtu <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN) {
968                 if (inet->cork.length + length > sizeof(struct ipv6hdr) + IPV6_MAXPLEN - fragheaderlen) {
969                         ipv6_local_error(sk, EMSGSIZE, fl, mtu-exthdrlen);
970                         return -EMSGSIZE;
971                 }
972         }
973
974         /*
975          * Let's try using as much space as possible.
976          * Use MTU if total length of the message fits into the MTU.
977          * Otherwise, we need to reserve fragment header and
978          * fragment alignment (= 8-15 octects, in total).
979          *
980          * Note that we may need to "move" the data from the tail of
981          * of the buffer to the new fragment when we split 
982          * the message.
983          *
984          * FIXME: It may be fragmented into multiple chunks 
985          *        at once if non-fragmentable extension headers
986          *        are too large.
987          * --yoshfuji 
988          */
989
990         inet->cork.length += length;
991         if (((length > mtu) && (sk->sk_protocol == IPPROTO_UDP)) &&
992             (rt->u.dst.dev->features & NETIF_F_UFO)) {
993
994                 err = ip6_ufo_append_data(sk, getfrag, from, length, hh_len,
995                                           fragheaderlen, transhdrlen, mtu,
996                                           flags);
997                 if (err)
998                         goto error;
999                 return 0;
1000         }
1001
1002         if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL)
1003                 goto alloc_new_skb;
1004
1005         while (length > 0) {
1006                 /* Check if the remaining data fits into current packet. */
1007                 copy = (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len;
1008                 if (copy < length)
1009                         copy = maxfraglen - skb->len;
1010
1011                 if (copy <= 0) {
1012                         char *data;
1013                         unsigned int datalen;
1014                         unsigned int fraglen;
1015                         unsigned int fraggap;
1016                         unsigned int alloclen;
1017                         struct sk_buff *skb_prev;
1018 alloc_new_skb:
1019                         skb_prev = skb;
1020
1021                         /* There's no room in the current skb */
1022                         if (skb_prev)
1023                                 fraggap = skb_prev->len - maxfraglen;
1024                         else
1025                                 fraggap = 0;
1026
1027                         /*
1028                          * If remaining data exceeds the mtu,
1029                          * we know we need more fragment(s).
1030                          */
1031                         datalen = length + fraggap;
1032                         if (datalen > (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen)
1033                                 datalen = maxfraglen - fragheaderlen;
1034
1035                         fraglen = datalen + fragheaderlen;
1036                         if ((flags & MSG_MORE) &&
1037                             !(rt->u.dst.dev->features&NETIF_F_SG))
1038                                 alloclen = mtu;
1039                         else
1040                                 alloclen = datalen + fragheaderlen;
1041
1042                         /*
1043                          * The last fragment gets additional space at tail.
1044                          * Note: we overallocate on fragments with MSG_MODE
1045                          * because we have no idea if we're the last one.
1046                          */
1047                         if (datalen == length + fraggap)
1048                                 alloclen += rt->u.dst.trailer_len;
1049
1050                         /*
1051                          * We just reserve space for fragment header.
1052                          * Note: this may be overallocation if the message 
1053                          * (without MSG_MORE) fits into the MTU.
1054                          */
1055                         alloclen += sizeof(struct frag_hdr);
1056
1057                         if (transhdrlen) {
1058                                 skb = sock_alloc_send_skb(sk,
1059                                                 alloclen + hh_len,
1060                                                 (flags & MSG_DONTWAIT), &err);
1061                         } else {
1062                                 skb = NULL;
1063                                 if (atomic_read(&sk->sk_wmem_alloc) <=
1064                                     2 * sk->sk_sndbuf)
1065                                         skb = sock_wmalloc(sk,
1066                                                            alloclen + hh_len, 1,
1067                                                            sk->sk_allocation);
1068                                 if (unlikely(skb == NULL))
1069                                         err = -ENOBUFS;
1070                         }
1071                         if (skb == NULL)
1072                                 goto error;
1073                         /*
1074                          *      Fill in the control structures
1075                          */
1076                         skb->ip_summed = csummode;
1077                         skb->csum = 0;
1078                         /* reserve for fragmentation */
1079                         skb_reserve(skb, hh_len+sizeof(struct frag_hdr));
1080
1081                         /*
1082                          *      Find where to start putting bytes
1083                          */
1084                         data = skb_put(skb, fraglen);
1085                         skb->nh.raw = data + exthdrlen;
1086                         data += fragheaderlen;
1087                         skb->h.raw = data + exthdrlen;
1088
1089                         if (fraggap) {
1090                                 skb->csum = skb_copy_and_csum_bits(
1091                                         skb_prev, maxfraglen,
1092                                         data + transhdrlen, fraggap, 0);
1093                                 skb_prev->csum = csum_sub(skb_prev->csum,
1094                                                           skb->csum);
1095                                 data += fraggap;
1096                                 skb_trim(skb_prev, maxfraglen);
1097                         }
1098                         copy = datalen - transhdrlen - fraggap;
1099                         if (copy < 0) {
1100                                 err = -EINVAL;
1101                                 kfree_skb(skb);
1102                                 goto error;
1103                         } else if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) {
1104                                 err = -EFAULT;
1105                                 kfree_skb(skb);
1106                                 goto error;
1107                         }
1108
1109                         offset += copy;
1110                         length -= datalen - fraggap;
1111                         transhdrlen = 0;
1112                         exthdrlen = 0;
1113                         csummode = CHECKSUM_NONE;
1114
1115                         /*
1116                          * Put the packet on the pending queue
1117                          */
1118                         __skb_queue_tail(&sk->sk_write_queue, skb);
1119                         continue;
1120                 }
1121
1122                 if (copy > length)
1123                         copy = length;
1124
1125                 if (!(rt->u.dst.dev->features&NETIF_F_SG)) {
1126                         unsigned int off;
1127
1128                         off = skb->len;
1129                         if (getfrag(from, skb_put(skb, copy),
1130                                                 offset, copy, off, skb) < 0) {
1131                                 __skb_trim(skb, off);
1132                                 err = -EFAULT;
1133                                 goto error;
1134                         }
1135                 } else {
1136                         int i = skb_shinfo(skb)->nr_frags;
1137                         skb_frag_t *frag = &skb_shinfo(skb)->frags[i-1];
1138                         struct page *page = sk->sk_sndmsg_page;
1139                         int off = sk->sk_sndmsg_off;
1140                         unsigned int left;
1141
1142                         if (page && (left = PAGE_SIZE - off) > 0) {
1143                                 if (copy >= left)
1144                                         copy = left;
1145                                 if (page != frag->page) {
1146                                         if (i == MAX_SKB_FRAGS) {
1147                                                 err = -EMSGSIZE;
1148                                                 goto error;
1149                                         }
1150                                         get_page(page);
1151                                         skb_fill_page_desc(skb, i, page, sk->sk_sndmsg_off, 0);
1152                                         frag = &skb_shinfo(skb)->frags[i];
1153                                 }
1154                         } else if(i < MAX_SKB_FRAGS) {
1155                                 if (copy > PAGE_SIZE)
1156                                         copy = PAGE_SIZE;
1157                                 page = alloc_pages(sk->sk_allocation, 0);
1158                                 if (page == NULL) {
1159                                         err = -ENOMEM;
1160                                         goto error;
1161                                 }
1162                                 sk->sk_sndmsg_page = page;
1163                                 sk->sk_sndmsg_off = 0;
1164
1165                                 skb_fill_page_desc(skb, i, page, 0, 0);
1166                                 frag = &skb_shinfo(skb)->frags[i];
1167                                 skb->truesize += PAGE_SIZE;
1168                                 atomic_add(PAGE_SIZE, &sk->sk_wmem_alloc);
1169                         } else {
1170                                 err = -EMSGSIZE;
1171                                 goto error;
1172                         }
1173                         if (getfrag(from, page_address(frag->page)+frag->page_offset+frag->size, offset, copy, skb->len, skb) < 0) {
1174                                 err = -EFAULT;
1175                                 goto error;
1176                         }
1177                         sk->sk_sndmsg_off += copy;
1178                         frag->size += copy;
1179                         skb->len += copy;
1180                         skb->data_len += copy;
1181                 }
1182                 offset += copy;
1183                 length -= copy;
1184         }
1185         return 0;
1186 error:
1187         inet->cork.length -= length;
1188         IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
1189         return err;
1190 }
1191
1192 int ip6_push_pending_frames(struct sock *sk)
1193 {
1194         struct sk_buff *skb, *tmp_skb;
1195         struct sk_buff **tail_skb;
1196         struct in6_addr final_dst_buf, *final_dst = &final_dst_buf;
1197         struct inet_sock *inet = inet_sk(sk);
1198         struct ipv6_pinfo *np = inet6_sk(sk);
1199         struct ipv6hdr *hdr;
1200         struct ipv6_txoptions *opt = np->cork.opt;
1201         struct rt6_info *rt = np->cork.rt;
1202         struct flowi *fl = &inet->cork.fl;
1203         unsigned char proto = fl->proto;
1204         int err = 0;
1205
1206         if ((skb = __skb_dequeue(&sk->sk_write_queue)) == NULL)
1207                 goto out;
1208         tail_skb = &(skb_shinfo(skb)->frag_list);
1209
1210         /* move skb->data to ip header from ext header */
1211         if (skb->data < skb->nh.raw)
1212                 __skb_pull(skb, skb->nh.raw - skb->data);
1213         while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) {
1214                 __skb_pull(tmp_skb, skb->h.raw - skb->nh.raw);
1215                 *tail_skb = tmp_skb;
1216                 tail_skb = &(tmp_skb->next);
1217                 skb->len += tmp_skb->len;
1218                 skb->data_len += tmp_skb->len;
1219                 skb->truesize += tmp_skb->truesize;
1220                 __sock_put(tmp_skb->sk);
1221                 tmp_skb->destructor = NULL;
1222                 tmp_skb->sk = NULL;
1223         }
1224
1225         ipv6_addr_copy(final_dst, &fl->fl6_dst);
1226         __skb_pull(skb, skb->h.raw - skb->nh.raw);
1227         if (opt && opt->opt_flen)
1228                 ipv6_push_frag_opts(skb, opt, &proto);
1229         if (opt && opt->opt_nflen)
1230                 ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst);
1231
1232         skb->nh.ipv6h = hdr = (struct ipv6hdr*) skb_push(skb, sizeof(struct ipv6hdr));
1233         
1234         *(u32*)hdr = fl->fl6_flowlabel |
1235                      htonl(0x60000000 | ((int)np->cork.tclass << 20));
1236
1237         if (skb->len <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN)
1238                 hdr->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
1239         else
1240                 hdr->payload_len = 0;
1241         hdr->hop_limit = np->cork.hop_limit;
1242         hdr->nexthdr = proto;
1243         ipv6_addr_copy(&hdr->saddr, &fl->fl6_src);
1244         ipv6_addr_copy(&hdr->daddr, final_dst);
1245
1246         skb->priority = sk->sk_priority;
1247
1248         skb->dst = dst_clone(&rt->u.dst);
1249         IP6_INC_STATS(IPSTATS_MIB_OUTREQUESTS); 
1250         err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, skb->dst->dev, dst_output);
1251         if (err) {
1252                 if (err > 0)
1253                         err = np->recverr ? net_xmit_errno(err) : 0;
1254                 if (err)
1255                         goto error;
1256         }
1257
1258 out:
1259         inet->cork.flags &= ~IPCORK_OPT;
1260         kfree(np->cork.opt);
1261         np->cork.opt = NULL;
1262         if (np->cork.rt) {
1263                 dst_release(&np->cork.rt->u.dst);
1264                 np->cork.rt = NULL;
1265                 inet->cork.flags &= ~IPCORK_ALLFRAG;
1266         }
1267         memset(&inet->cork.fl, 0, sizeof(inet->cork.fl));
1268         return err;
1269 error:
1270         goto out;
1271 }
1272
1273 void ip6_flush_pending_frames(struct sock *sk)
1274 {
1275         struct inet_sock *inet = inet_sk(sk);
1276         struct ipv6_pinfo *np = inet6_sk(sk);
1277         struct sk_buff *skb;
1278
1279         while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) {
1280                 IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
1281                 kfree_skb(skb);
1282         }
1283
1284         inet->cork.flags &= ~IPCORK_OPT;
1285
1286         kfree(np->cork.opt);
1287         np->cork.opt = NULL;
1288         if (np->cork.rt) {
1289                 dst_release(&np->cork.rt->u.dst);
1290                 np->cork.rt = NULL;
1291                 inet->cork.flags &= ~IPCORK_ALLFRAG;
1292         }
1293         memset(&inet->cork.fl, 0, sizeof(inet->cork.fl));
1294 }