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1 /*
2 * IPv6 output functions
3 * Linux INET6 implementation
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 *
8 * $Id: ip6_output.c,v 1.34 2002/02/01 22:01:04 davem Exp $
9 *
10 * Based on linux/net/ipv4/ip_output.c
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; either version
15 * 2 of the License, or (at your option) any later version.
16 *
17 * Changes:
18 * A.N.Kuznetsov : airthmetics in fragmentation.
19 * extension headers are implemented.
20 * route changes now work.
21 * ip6_forward does not confuse sniffers.
22 * etc.
23 *
24 * H. von Brand : Added missing #include <linux/string.h>
25 * Imran Patel : frag id should be in NBO
26 * Kazunori MIYAZAWA @USAGI
27 * : add ip6_append_data and related functions
28 * for datagram xmit
29 */
30
31 #include <linux/errno.h>
32 #include <linux/types.h>
33 #include <linux/string.h>
34 #include <linux/socket.h>
35 #include <linux/net.h>
36 #include <linux/netdevice.h>
37 #include <linux/if_arp.h>
38 #include <linux/in6.h>
39 #include <linux/tcp.h>
40 #include <linux/route.h>
41 #include <linux/module.h>
42
43 #include <linux/netfilter.h>
44 #include <linux/netfilter_ipv6.h>
45
46 #include <net/sock.h>
47 #include <net/snmp.h>
48
49 #include <net/ipv6.h>
50 #include <net/ndisc.h>
51 #include <net/protocol.h>
52 #include <net/ip6_route.h>
53 #include <net/addrconf.h>
54 #include <net/rawv6.h>
55 #include <net/icmp.h>
56 #include <net/xfrm.h>
57 #include <net/checksum.h>
58
59 static int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *));
60
61 static __inline__ void ipv6_select_ident(struct sk_buff *skb, struct frag_hdr *fhdr)
62 {
63 static u32 ipv6_fragmentation_id = 1;
64 static DEFINE_SPINLOCK(ip6_id_lock);
65
66 spin_lock_bh(&ip6_id_lock);
67 fhdr->identification = htonl(ipv6_fragmentation_id);
68 if (++ipv6_fragmentation_id == 0)
69 ipv6_fragmentation_id = 1;
70 spin_unlock_bh(&ip6_id_lock);
71 }
72
73 static 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 static inline int ip6_skb_dst_mtu(struct sk_buff *skb)
141 {
142 struct ipv6_pinfo *np = skb->sk ? inet6_sk(skb->sk) : NULL;
143
144 return (np && np->pmtudisc == IPV6_PMTUDISC_PROBE) ?
145 skb->dst->dev->mtu : dst_mtu(skb->dst);
146 }
147
148 int ip6_output(struct sk_buff *skb)
149 {
150 if ((skb->len > ip6_skb_dst_mtu(skb) && !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 unsigned 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 if (skb2 == NULL) {
186 IP6_INC_STATS(ip6_dst_idev(skb->dst),
187 IPSTATS_MIB_OUTDISCARDS);
188 kfree_skb(skb);
189 return -ENOBUFS;
190 }
191 kfree_skb(skb);
192 skb = skb2;
193 if (sk)
194 skb_set_owner_w(skb, sk);
195 }
196 if (opt->opt_flen)
197 ipv6_push_frag_opts(skb, opt, &proto);
198 if (opt->opt_nflen)
199 ipv6_push_nfrag_opts(skb, opt, &proto, &first_hop);
200 }
201
202 skb_push(skb, sizeof(struct ipv6hdr));
203 skb_reset_network_header(skb);
204 hdr = ipv6_hdr(skb);
205
206 /*
207 * Fill in the IPv6 header
208 */
209
210 hlimit = -1;
211 if (np)
212 hlimit = np->hop_limit;
213 if (hlimit < 0)
214 hlimit = dst_metric(dst, RTAX_HOPLIMIT);
215 if (hlimit < 0)
216 hlimit = ipv6_get_hoplimit(dst->dev);
217
218 tclass = -1;
219 if (np)
220 tclass = np->tclass;
221 if (tclass < 0)
222 tclass = 0;
223
224 *(__be32 *)hdr = htonl(0x60000000 | (tclass << 20)) | fl->fl6_flowlabel;
225
226 hdr->payload_len = htons(seg_len);
227 hdr->nexthdr = proto;
228 hdr->hop_limit = hlimit;
229
230 ipv6_addr_copy(&hdr->saddr, &fl->fl6_src);
231 ipv6_addr_copy(&hdr->daddr, first_hop);
232
233 skb->priority = sk->sk_priority;
234
235 mtu = dst_mtu(dst);
236 if ((skb->len <= mtu) || ipfragok || skb_is_gso(skb)) {
237 IP6_INC_STATS(ip6_dst_idev(skb->dst),
238 IPSTATS_MIB_OUTREQUESTS);
239 return NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, dst->dev,
240 dst_output);
241 }
242
243 if (net_ratelimit())
244 printk(KERN_DEBUG "IPv6: sending pkt_too_big to self\n");
245 skb->dev = dst->dev;
246 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, skb->dev);
247 IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_FRAGFAILS);
248 kfree_skb(skb);
249 return -EMSGSIZE;
250 }
251
252 EXPORT_SYMBOL(ip6_xmit);
253
254 /*
255 * To avoid extra problems ND packets are send through this
256 * routine. It's code duplication but I really want to avoid
257 * extra checks since ipv6_build_header is used by TCP (which
258 * is for us performance critical)
259 */
260
261 int ip6_nd_hdr(struct sock *sk, struct sk_buff *skb, struct net_device *dev,
262 struct in6_addr *saddr, struct in6_addr *daddr,
263 int proto, int len)
264 {
265 struct ipv6_pinfo *np = inet6_sk(sk);
266 struct ipv6hdr *hdr;
267 int totlen;
268
269 skb->protocol = htons(ETH_P_IPV6);
270 skb->dev = dev;
271
272 totlen = len + sizeof(struct ipv6hdr);
273
274 skb_reset_network_header(skb);
275 skb_put(skb, sizeof(struct ipv6hdr));
276 hdr = ipv6_hdr(skb);
277
278 *(__be32*)hdr = htonl(0x60000000);
279
280 hdr->payload_len = htons(len);
281 hdr->nexthdr = proto;
282 hdr->hop_limit = np->hop_limit;
283
284 ipv6_addr_copy(&hdr->saddr, saddr);
285 ipv6_addr_copy(&hdr->daddr, daddr);
286
287 return 0;
288 }
289
290 static int ip6_call_ra_chain(struct sk_buff *skb, int sel)
291 {
292 struct ip6_ra_chain *ra;
293 struct sock *last = NULL;
294
295 read_lock(&ip6_ra_lock);
296 for (ra = ip6_ra_chain; ra; ra = ra->next) {
297 struct sock *sk = ra->sk;
298 if (sk && ra->sel == sel &&
299 (!sk->sk_bound_dev_if ||
300 sk->sk_bound_dev_if == skb->dev->ifindex)) {
301 if (last) {
302 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
303 if (skb2)
304 rawv6_rcv(last, skb2);
305 }
306 last = sk;
307 }
308 }
309
310 if (last) {
311 rawv6_rcv(last, skb);
312 read_unlock(&ip6_ra_lock);
313 return 1;
314 }
315 read_unlock(&ip6_ra_lock);
316 return 0;
317 }
318
319 static int ip6_forward_proxy_check(struct sk_buff *skb)
320 {
321 struct ipv6hdr *hdr = ipv6_hdr(skb);
322 u8 nexthdr = hdr->nexthdr;
323 int offset;
324
325 if (ipv6_ext_hdr(nexthdr)) {
326 offset = ipv6_skip_exthdr(skb, sizeof(*hdr), &nexthdr);
327 if (offset < 0)
328 return 0;
329 } else
330 offset = sizeof(struct ipv6hdr);
331
332 if (nexthdr == IPPROTO_ICMPV6) {
333 struct icmp6hdr *icmp6;
334
335 if (!pskb_may_pull(skb, (skb_network_header(skb) +
336 offset + 1 - skb->data)))
337 return 0;
338
339 icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset);
340
341 switch (icmp6->icmp6_type) {
342 case NDISC_ROUTER_SOLICITATION:
343 case NDISC_ROUTER_ADVERTISEMENT:
344 case NDISC_NEIGHBOUR_SOLICITATION:
345 case NDISC_NEIGHBOUR_ADVERTISEMENT:
346 case NDISC_REDIRECT:
347 /* For reaction involving unicast neighbor discovery
348 * message destined to the proxied address, pass it to
349 * input function.
350 */
351 return 1;
352 default:
353 break;
354 }
355 }
356
357 /*
358 * The proxying router can't forward traffic sent to a link-local
359 * address, so signal the sender and discard the packet. This
360 * behavior is clarified by the MIPv6 specification.
361 */
362 if (ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) {
363 dst_link_failure(skb);
364 return -1;
365 }
366
367 return 0;
368 }
369
370 static inline int ip6_forward_finish(struct sk_buff *skb)
371 {
372 return dst_output(skb);
373 }
374
375 int ip6_forward(struct sk_buff *skb)
376 {
377 struct dst_entry *dst = skb->dst;
378 struct ipv6hdr *hdr = ipv6_hdr(skb);
379 struct inet6_skb_parm *opt = IP6CB(skb);
380
381 if (ipv6_devconf.forwarding == 0)
382 goto error;
383
384 if (!xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) {
385 IP6_INC_STATS(ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS);
386 goto drop;
387 }
388
389 skb_forward_csum(skb);
390
391 /*
392 * We DO NOT make any processing on
393 * RA packets, pushing them to user level AS IS
394 * without ane WARRANTY that application will be able
395 * to interpret them. The reason is that we
396 * cannot make anything clever here.
397 *
398 * We are not end-node, so that if packet contains
399 * AH/ESP, we cannot make anything.
400 * Defragmentation also would be mistake, RA packets
401 * cannot be fragmented, because there is no warranty
402 * that different fragments will go along one path. --ANK
403 */
404 if (opt->ra) {
405 u8 *ptr = skb_network_header(skb) + opt->ra;
406 if (ip6_call_ra_chain(skb, (ptr[2]<<8) + ptr[3]))
407 return 0;
408 }
409
410 /*
411 * check and decrement ttl
412 */
413 if (hdr->hop_limit <= 1) {
414 /* Force OUTPUT device used as source address */
415 skb->dev = dst->dev;
416 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
417 0, skb->dev);
418 IP6_INC_STATS_BH(ip6_dst_idev(dst), IPSTATS_MIB_INHDRERRORS);
419
420 kfree_skb(skb);
421 return -ETIMEDOUT;
422 }
423
424 /* XXX: idev->cnf.proxy_ndp? */
425 if (ipv6_devconf.proxy_ndp &&
426 pneigh_lookup(&nd_tbl, &hdr->daddr, skb->dev, 0)) {
427 int proxied = ip6_forward_proxy_check(skb);
428 if (proxied > 0)
429 return ip6_input(skb);
430 else if (proxied < 0) {
431 IP6_INC_STATS(ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS);
432 goto drop;
433 }
434 }
435
436 if (!xfrm6_route_forward(skb)) {
437 IP6_INC_STATS(ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS);
438 goto drop;
439 }
440 dst = skb->dst;
441
442 /* IPv6 specs say nothing about it, but it is clear that we cannot
443 send redirects to source routed frames.
444 We don't send redirects to frames decapsulated from IPsec.
445 */
446 if (skb->dev == dst->dev && dst->neighbour && opt->srcrt == 0 &&
447 !skb->sp) {
448 struct in6_addr *target = NULL;
449 struct rt6_info *rt;
450 struct neighbour *n = dst->neighbour;
451
452 /*
453 * incoming and outgoing devices are the same
454 * send a redirect.
455 */
456
457 rt = (struct rt6_info *) dst;
458 if ((rt->rt6i_flags & RTF_GATEWAY))
459 target = (struct in6_addr*)&n->primary_key;
460 else
461 target = &hdr->daddr;
462
463 /* Limit redirects both by destination (here)
464 and by source (inside ndisc_send_redirect)
465 */
466 if (xrlim_allow(dst, 1*HZ))
467 ndisc_send_redirect(skb, n, target);
468 } else {
469 int addrtype = ipv6_addr_type(&hdr->saddr);
470
471 /* This check is security critical. */
472 if (addrtype & (IPV6_ADDR_MULTICAST|IPV6_ADDR_LOOPBACK))
473 goto error;
474 if (addrtype & IPV6_ADDR_LINKLOCAL) {
475 icmpv6_send(skb, ICMPV6_DEST_UNREACH,
476 ICMPV6_NOT_NEIGHBOUR, 0, skb->dev);
477 goto error;
478 }
479 }
480
481 if (skb->len > dst_mtu(dst)) {
482 /* Again, force OUTPUT device used as source address */
483 skb->dev = dst->dev;
484 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, dst_mtu(dst), skb->dev);
485 IP6_INC_STATS_BH(ip6_dst_idev(dst), IPSTATS_MIB_INTOOBIGERRORS);
486 IP6_INC_STATS_BH(ip6_dst_idev(dst), IPSTATS_MIB_FRAGFAILS);
487 kfree_skb(skb);
488 return -EMSGSIZE;
489 }
490
491 if (skb_cow(skb, dst->dev->hard_header_len)) {
492 IP6_INC_STATS(ip6_dst_idev(dst), IPSTATS_MIB_OUTDISCARDS);
493 goto drop;
494 }
495
496 hdr = ipv6_hdr(skb);
497
498 /* Mangling hops number delayed to point after skb COW */
499
500 hdr->hop_limit--;
501
502 IP6_INC_STATS_BH(ip6_dst_idev(dst), IPSTATS_MIB_OUTFORWDATAGRAMS);
503 return NF_HOOK(PF_INET6,NF_IP6_FORWARD, skb, skb->dev, dst->dev, ip6_forward_finish);
504
505 error:
506 IP6_INC_STATS_BH(ip6_dst_idev(dst), IPSTATS_MIB_INADDRERRORS);
507 drop:
508 kfree_skb(skb);
509 return -EINVAL;
510 }
511
512 static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from)
513 {
514 to->pkt_type = from->pkt_type;
515 to->priority = from->priority;
516 to->protocol = from->protocol;
517 dst_release(to->dst);
518 to->dst = dst_clone(from->dst);
519 to->dev = from->dev;
520 to->mark = from->mark;
521
522 #ifdef CONFIG_NET_SCHED
523 to->tc_index = from->tc_index;
524 #endif
525 nf_copy(to, from);
526 #if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \
527 defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE)
528 to->nf_trace = from->nf_trace;
529 #endif
530 skb_copy_secmark(to, from);
531 }
532
533 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr)
534 {
535 u16 offset = sizeof(struct ipv6hdr);
536 struct ipv6_opt_hdr *exthdr =
537 (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
538 unsigned int packet_len = skb->tail - skb->network_header;
539 int found_rhdr = 0;
540 *nexthdr = &ipv6_hdr(skb)->nexthdr;
541
542 while (offset + 1 <= packet_len) {
543
544 switch (**nexthdr) {
545
546 case NEXTHDR_HOP:
547 break;
548 case NEXTHDR_ROUTING:
549 found_rhdr = 1;
550 break;
551 case NEXTHDR_DEST:
552 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
553 if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
554 break;
555 #endif
556 if (found_rhdr)
557 return offset;
558 break;
559 default :
560 return offset;
561 }
562
563 offset += ipv6_optlen(exthdr);
564 *nexthdr = &exthdr->nexthdr;
565 exthdr = (struct ipv6_opt_hdr *)(skb_network_header(skb) +
566 offset);
567 }
568
569 return offset;
570 }
571 EXPORT_SYMBOL_GPL(ip6_find_1stfragopt);
572
573 static int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *))
574 {
575 struct net_device *dev;
576 struct sk_buff *frag;
577 struct rt6_info *rt = (struct rt6_info*)skb->dst;
578 struct ipv6_pinfo *np = skb->sk ? inet6_sk(skb->sk) : NULL;
579 struct ipv6hdr *tmp_hdr;
580 struct frag_hdr *fh;
581 unsigned int mtu, hlen, left, len;
582 __be32 frag_id = 0;
583 int ptr, offset = 0, err=0;
584 u8 *prevhdr, nexthdr = 0;
585
586 dev = rt->u.dst.dev;
587 hlen = ip6_find_1stfragopt(skb, &prevhdr);
588 nexthdr = *prevhdr;
589
590 mtu = ip6_skb_dst_mtu(skb);
591
592 /* We must not fragment if the socket is set to force MTU discovery
593 * or if the skb it not generated by a local socket. (This last
594 * check should be redundant, but it's free.)
595 */
596 if (!np || np->pmtudisc >= IPV6_PMTUDISC_DO) {
597 skb->dev = skb->dst->dev;
598 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, skb->dev);
599 IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_FRAGFAILS);
600 kfree_skb(skb);
601 return -EMSGSIZE;
602 }
603
604 if (np && np->frag_size < mtu) {
605 if (np->frag_size)
606 mtu = np->frag_size;
607 }
608 mtu -= hlen + sizeof(struct frag_hdr);
609
610 if (skb_shinfo(skb)->frag_list) {
611 int first_len = skb_pagelen(skb);
612
613 if (first_len - hlen > mtu ||
614 ((first_len - hlen) & 7) ||
615 skb_cloned(skb))
616 goto slow_path;
617
618 for (frag = skb_shinfo(skb)->frag_list; frag; frag = frag->next) {
619 /* Correct geometry. */
620 if (frag->len > mtu ||
621 ((frag->len & 7) && frag->next) ||
622 skb_headroom(frag) < hlen)
623 goto slow_path;
624
625 /* Partially cloned skb? */
626 if (skb_shared(frag))
627 goto slow_path;
628
629 BUG_ON(frag->sk);
630 if (skb->sk) {
631 sock_hold(skb->sk);
632 frag->sk = skb->sk;
633 frag->destructor = sock_wfree;
634 skb->truesize -= frag->truesize;
635 }
636 }
637
638 err = 0;
639 offset = 0;
640 frag = skb_shinfo(skb)->frag_list;
641 skb_shinfo(skb)->frag_list = NULL;
642 /* BUILD HEADER */
643
644 *prevhdr = NEXTHDR_FRAGMENT;
645 tmp_hdr = kmemdup(skb_network_header(skb), hlen, GFP_ATOMIC);
646 if (!tmp_hdr) {
647 IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_FRAGFAILS);
648 return -ENOMEM;
649 }
650
651 __skb_pull(skb, hlen);
652 fh = (struct frag_hdr*)__skb_push(skb, sizeof(struct frag_hdr));
653 __skb_push(skb, hlen);
654 skb_reset_network_header(skb);
655 memcpy(skb_network_header(skb), tmp_hdr, hlen);
656
657 ipv6_select_ident(skb, fh);
658 fh->nexthdr = nexthdr;
659 fh->reserved = 0;
660 fh->frag_off = htons(IP6_MF);
661 frag_id = fh->identification;
662
663 first_len = skb_pagelen(skb);
664 skb->data_len = first_len - skb_headlen(skb);
665 skb->len = first_len;
666 ipv6_hdr(skb)->payload_len = htons(first_len -
667 sizeof(struct ipv6hdr));
668
669 dst_hold(&rt->u.dst);
670
671 for (;;) {
672 /* Prepare header of the next frame,
673 * before previous one went down. */
674 if (frag) {
675 frag->ip_summed = CHECKSUM_NONE;
676 skb_reset_transport_header(frag);
677 fh = (struct frag_hdr*)__skb_push(frag, sizeof(struct frag_hdr));
678 __skb_push(frag, hlen);
679 skb_reset_network_header(frag);
680 memcpy(skb_network_header(frag), tmp_hdr,
681 hlen);
682 offset += skb->len - hlen - sizeof(struct frag_hdr);
683 fh->nexthdr = nexthdr;
684 fh->reserved = 0;
685 fh->frag_off = htons(offset);
686 if (frag->next != NULL)
687 fh->frag_off |= htons(IP6_MF);
688 fh->identification = frag_id;
689 ipv6_hdr(frag)->payload_len =
690 htons(frag->len -
691 sizeof(struct ipv6hdr));
692 ip6_copy_metadata(frag, skb);
693 }
694
695 err = output(skb);
696 if(!err)
697 IP6_INC_STATS(ip6_dst_idev(&rt->u.dst), IPSTATS_MIB_FRAGCREATES);
698
699 if (err || !frag)
700 break;
701
702 skb = frag;
703 frag = skb->next;
704 skb->next = NULL;
705 }
706
707 kfree(tmp_hdr);
708
709 if (err == 0) {
710 IP6_INC_STATS(ip6_dst_idev(&rt->u.dst), IPSTATS_MIB_FRAGOKS);
711 dst_release(&rt->u.dst);
712 return 0;
713 }
714
715 while (frag) {
716 skb = frag->next;
717 kfree_skb(frag);
718 frag = skb;
719 }
720
721 IP6_INC_STATS(ip6_dst_idev(&rt->u.dst), IPSTATS_MIB_FRAGFAILS);
722 dst_release(&rt->u.dst);
723 return err;
724 }
725
726 slow_path:
727 left = skb->len - hlen; /* Space per frame */
728 ptr = hlen; /* Where to start from */
729
730 /*
731 * Fragment the datagram.
732 */
733
734 *prevhdr = NEXTHDR_FRAGMENT;
735
736 /*
737 * Keep copying data until we run out.
738 */
739 while(left > 0) {
740 len = left;
741 /* IF: it doesn't fit, use 'mtu' - the data space left */
742 if (len > mtu)
743 len = mtu;
744 /* IF: we are not sending upto and including the packet end
745 then align the next start on an eight byte boundary */
746 if (len < left) {
747 len &= ~7;
748 }
749 /*
750 * Allocate buffer.
751 */
752
753 if ((frag = alloc_skb(len+hlen+sizeof(struct frag_hdr)+LL_RESERVED_SPACE(rt->u.dst.dev), GFP_ATOMIC)) == NULL) {
754 NETDEBUG(KERN_INFO "IPv6: frag: no memory for new fragment!\n");
755 IP6_INC_STATS(ip6_dst_idev(skb->dst),
756 IPSTATS_MIB_FRAGFAILS);
757 err = -ENOMEM;
758 goto fail;
759 }
760
761 /*
762 * Set up data on packet
763 */
764
765 ip6_copy_metadata(frag, skb);
766 skb_reserve(frag, LL_RESERVED_SPACE(rt->u.dst.dev));
767 skb_put(frag, len + hlen + sizeof(struct frag_hdr));
768 skb_reset_network_header(frag);
769 fh = (struct frag_hdr *)(skb_network_header(frag) + hlen);
770 frag->transport_header = (frag->network_header + hlen +
771 sizeof(struct frag_hdr));
772
773 /*
774 * Charge the memory for the fragment to any owner
775 * it might possess
776 */
777 if (skb->sk)
778 skb_set_owner_w(frag, skb->sk);
779
780 /*
781 * Copy the packet header into the new buffer.
782 */
783 skb_copy_from_linear_data(skb, skb_network_header(frag), hlen);
784
785 /*
786 * Build fragment header.
787 */
788 fh->nexthdr = nexthdr;
789 fh->reserved = 0;
790 if (!frag_id) {
791 ipv6_select_ident(skb, fh);
792 frag_id = fh->identification;
793 } else
794 fh->identification = frag_id;
795
796 /*
797 * Copy a block of the IP datagram.
798 */
799 if (skb_copy_bits(skb, ptr, skb_transport_header(frag), len))
800 BUG();
801 left -= len;
802
803 fh->frag_off = htons(offset);
804 if (left > 0)
805 fh->frag_off |= htons(IP6_MF);
806 ipv6_hdr(frag)->payload_len = htons(frag->len -
807 sizeof(struct ipv6hdr));
808
809 ptr += len;
810 offset += len;
811
812 /*
813 * Put this fragment into the sending queue.
814 */
815 err = output(frag);
816 if (err)
817 goto fail;
818
819 IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_FRAGCREATES);
820 }
821 IP6_INC_STATS(ip6_dst_idev(skb->dst),
822 IPSTATS_MIB_FRAGOKS);
823 kfree_skb(skb);
824 return err;
825
826 fail:
827 IP6_INC_STATS(ip6_dst_idev(skb->dst),
828 IPSTATS_MIB_FRAGFAILS);
829 kfree_skb(skb);
830 return err;
831 }
832
833 static inline int ip6_rt_check(struct rt6key *rt_key,
834 struct in6_addr *fl_addr,
835 struct in6_addr *addr_cache)
836 {
837 return ((rt_key->plen != 128 || !ipv6_addr_equal(fl_addr, &rt_key->addr)) &&
838 (addr_cache == NULL || !ipv6_addr_equal(fl_addr, addr_cache)));
839 }
840
841 static struct dst_entry *ip6_sk_dst_check(struct sock *sk,
842 struct dst_entry *dst,
843 struct flowi *fl)
844 {
845 struct ipv6_pinfo *np = inet6_sk(sk);
846 struct rt6_info *rt = (struct rt6_info *)dst;
847
848 if (!dst)
849 goto out;
850
851 /* Yes, checking route validity in not connected
852 * case is not very simple. Take into account,
853 * that we do not support routing by source, TOS,
854 * and MSG_DONTROUTE --ANK (980726)
855 *
856 * 1. ip6_rt_check(): If route was host route,
857 * check that cached destination is current.
858 * If it is network route, we still may
859 * check its validity using saved pointer
860 * to the last used address: daddr_cache.
861 * We do not want to save whole address now,
862 * (because main consumer of this service
863 * is tcp, which has not this problem),
864 * so that the last trick works only on connected
865 * sockets.
866 * 2. oif also should be the same.
867 */
868 if (ip6_rt_check(&rt->rt6i_dst, &fl->fl6_dst, np->daddr_cache) ||
869 #ifdef CONFIG_IPV6_SUBTREES
870 ip6_rt_check(&rt->rt6i_src, &fl->fl6_src, np->saddr_cache) ||
871 #endif
872 (fl->oif && fl->oif != dst->dev->ifindex)) {
873 dst_release(dst);
874 dst = NULL;
875 }
876
877 out:
878 return dst;
879 }
880
881 static int ip6_dst_lookup_tail(struct sock *sk,
882 struct dst_entry **dst, struct flowi *fl)
883 {
884 int err;
885
886 if (*dst == NULL)
887 *dst = ip6_route_output(sk, fl);
888
889 if ((err = (*dst)->error))
890 goto out_err_release;
891
892 if (ipv6_addr_any(&fl->fl6_src)) {
893 err = ipv6_get_saddr(*dst, &fl->fl6_dst, &fl->fl6_src);
894 if (err)
895 goto out_err_release;
896 }
897
898 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
899 /*
900 * Here if the dst entry we've looked up
901 * has a neighbour entry that is in the INCOMPLETE
902 * state and the src address from the flow is
903 * marked as OPTIMISTIC, we release the found
904 * dst entry and replace it instead with the
905 * dst entry of the nexthop router
906 */
907 if (!((*dst)->neighbour->nud_state & NUD_VALID)) {
908 struct inet6_ifaddr *ifp;
909 struct flowi fl_gw;
910 int redirect;
911
912 ifp = ipv6_get_ifaddr(&fl->fl6_src, (*dst)->dev, 1);
913
914 redirect = (ifp && ifp->flags & IFA_F_OPTIMISTIC);
915 if (ifp)
916 in6_ifa_put(ifp);
917
918 if (redirect) {
919 /*
920 * We need to get the dst entry for the
921 * default router instead
922 */
923 dst_release(*dst);
924 memcpy(&fl_gw, fl, sizeof(struct flowi));
925 memset(&fl_gw.fl6_dst, 0, sizeof(struct in6_addr));
926 *dst = ip6_route_output(sk, &fl_gw);
927 if ((err = (*dst)->error))
928 goto out_err_release;
929 }
930 }
931 #endif
932
933 return 0;
934
935 out_err_release:
936 dst_release(*dst);
937 *dst = NULL;
938 return err;
939 }
940
941 /**
942 * ip6_dst_lookup - perform route lookup on flow
943 * @sk: socket which provides route info
944 * @dst: pointer to dst_entry * for result
945 * @fl: flow to lookup
946 *
947 * This function performs a route lookup on the given flow.
948 *
949 * It returns zero on success, or a standard errno code on error.
950 */
951 int ip6_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi *fl)
952 {
953 *dst = NULL;
954 return ip6_dst_lookup_tail(sk, dst, fl);
955 }
956 EXPORT_SYMBOL_GPL(ip6_dst_lookup);
957
958 /**
959 * ip6_sk_dst_lookup - perform socket cached route lookup on flow
960 * @sk: socket which provides the dst cache and route info
961 * @dst: pointer to dst_entry * for result
962 * @fl: flow to lookup
963 *
964 * This function performs a route lookup on the given flow with the
965 * possibility of using the cached route in the socket if it is valid.
966 * It will take the socket dst lock when operating on the dst cache.
967 * As a result, this function can only be used in process context.
968 *
969 * It returns zero on success, or a standard errno code on error.
970 */
971 int ip6_sk_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi *fl)
972 {
973 *dst = NULL;
974 if (sk) {
975 *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie);
976 *dst = ip6_sk_dst_check(sk, *dst, fl);
977 }
978
979 return ip6_dst_lookup_tail(sk, dst, fl);
980 }
981 EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup);
982
983 static inline int ip6_ufo_append_data(struct sock *sk,
984 int getfrag(void *from, char *to, int offset, int len,
985 int odd, struct sk_buff *skb),
986 void *from, int length, int hh_len, int fragheaderlen,
987 int transhdrlen, int mtu,unsigned int flags)
988
989 {
990 struct sk_buff *skb;
991 int err;
992
993 /* There is support for UDP large send offload by network
994 * device, so create one single skb packet containing complete
995 * udp datagram
996 */
997 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) {
998 skb = sock_alloc_send_skb(sk,
999 hh_len + fragheaderlen + transhdrlen + 20,
1000 (flags & MSG_DONTWAIT), &err);
1001 if (skb == NULL)
1002 return -ENOMEM;
1003
1004 /* reserve space for Hardware header */
1005 skb_reserve(skb, hh_len);
1006
1007 /* create space for UDP/IP header */
1008 skb_put(skb,fragheaderlen + transhdrlen);
1009
1010 /* initialize network header pointer */
1011 skb_reset_network_header(skb);
1012
1013 /* initialize protocol header pointer */
1014 skb->transport_header = skb->network_header + fragheaderlen;
1015
1016 skb->ip_summed = CHECKSUM_PARTIAL;
1017 skb->csum = 0;
1018 sk->sk_sndmsg_off = 0;
1019 }
1020
1021 err = skb_append_datato_frags(sk,skb, getfrag, from,
1022 (length - transhdrlen));
1023 if (!err) {
1024 struct frag_hdr fhdr;
1025
1026 /* specify the length of each IP datagram fragment*/
1027 skb_shinfo(skb)->gso_size = mtu - fragheaderlen -
1028 sizeof(struct frag_hdr);
1029 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
1030 ipv6_select_ident(skb, &fhdr);
1031 skb_shinfo(skb)->ip6_frag_id = fhdr.identification;
1032 __skb_queue_tail(&sk->sk_write_queue, skb);
1033
1034 return 0;
1035 }
1036 /* There is not enough support do UPD LSO,
1037 * so follow normal path
1038 */
1039 kfree_skb(skb);
1040
1041 return err;
1042 }
1043
1044 int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
1045 int offset, int len, int odd, struct sk_buff *skb),
1046 void *from, int length, int transhdrlen,
1047 int hlimit, int tclass, struct ipv6_txoptions *opt, struct flowi *fl,
1048 struct rt6_info *rt, unsigned int flags)
1049 {
1050 struct inet_sock *inet = inet_sk(sk);
1051 struct ipv6_pinfo *np = inet6_sk(sk);
1052 struct sk_buff *skb;
1053 unsigned int maxfraglen, fragheaderlen;
1054 int exthdrlen;
1055 int hh_len;
1056 int mtu;
1057 int copy;
1058 int err;
1059 int offset = 0;
1060 int csummode = CHECKSUM_NONE;
1061
1062 if (flags&MSG_PROBE)
1063 return 0;
1064 if (skb_queue_empty(&sk->sk_write_queue)) {
1065 /*
1066 * setup for corking
1067 */
1068 if (opt) {
1069 if (np->cork.opt == NULL) {
1070 np->cork.opt = kmalloc(opt->tot_len,
1071 sk->sk_allocation);
1072 if (unlikely(np->cork.opt == NULL))
1073 return -ENOBUFS;
1074 } else if (np->cork.opt->tot_len < opt->tot_len) {
1075 printk(KERN_DEBUG "ip6_append_data: invalid option length\n");
1076 return -EINVAL;
1077 }
1078 memcpy(np->cork.opt, opt, opt->tot_len);
1079 inet->cork.flags |= IPCORK_OPT;
1080 /* need source address above miyazawa*/
1081 }
1082 dst_hold(&rt->u.dst);
1083 np->cork.rt = rt;
1084 inet->cork.fl = *fl;
1085 np->cork.hop_limit = hlimit;
1086 np->cork.tclass = tclass;
1087 mtu = np->pmtudisc == IPV6_PMTUDISC_PROBE ?
1088 rt->u.dst.dev->mtu : dst_mtu(rt->u.dst.path);
1089 if (np->frag_size < mtu) {
1090 if (np->frag_size)
1091 mtu = np->frag_size;
1092 }
1093 inet->cork.fragsize = mtu;
1094 if (dst_allfrag(rt->u.dst.path))
1095 inet->cork.flags |= IPCORK_ALLFRAG;
1096 inet->cork.length = 0;
1097 sk->sk_sndmsg_page = NULL;
1098 sk->sk_sndmsg_off = 0;
1099 exthdrlen = rt->u.dst.header_len + (opt ? opt->opt_flen : 0);
1100 length += exthdrlen;
1101 transhdrlen += exthdrlen;
1102 } else {
1103 rt = np->cork.rt;
1104 fl = &inet->cork.fl;
1105 if (inet->cork.flags & IPCORK_OPT)
1106 opt = np->cork.opt;
1107 transhdrlen = 0;
1108 exthdrlen = 0;
1109 mtu = inet->cork.fragsize;
1110 }
1111
1112 hh_len = LL_RESERVED_SPACE(rt->u.dst.dev);
1113
1114 fragheaderlen = sizeof(struct ipv6hdr) + rt->u.dst.nfheader_len + (opt ? opt->opt_nflen : 0);
1115 maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - sizeof(struct frag_hdr);
1116
1117 if (mtu <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN) {
1118 if (inet->cork.length + length > sizeof(struct ipv6hdr) + IPV6_MAXPLEN - fragheaderlen) {
1119 ipv6_local_error(sk, EMSGSIZE, fl, mtu-exthdrlen);
1120 return -EMSGSIZE;
1121 }
1122 }
1123
1124 /*
1125 * Let's try using as much space as possible.
1126 * Use MTU if total length of the message fits into the MTU.
1127 * Otherwise, we need to reserve fragment header and
1128 * fragment alignment (= 8-15 octects, in total).
1129 *
1130 * Note that we may need to "move" the data from the tail of
1131 * of the buffer to the new fragment when we split
1132 * the message.
1133 *
1134 * FIXME: It may be fragmented into multiple chunks
1135 * at once if non-fragmentable extension headers
1136 * are too large.
1137 * --yoshfuji
1138 */
1139
1140 inet->cork.length += length;
1141 if (((length > mtu) && (sk->sk_protocol == IPPROTO_UDP)) &&
1142 (rt->u.dst.dev->features & NETIF_F_UFO)) {
1143
1144 err = ip6_ufo_append_data(sk, getfrag, from, length, hh_len,
1145 fragheaderlen, transhdrlen, mtu,
1146 flags);
1147 if (err)
1148 goto error;
1149 return 0;
1150 }
1151
1152 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL)
1153 goto alloc_new_skb;
1154
1155 while (length > 0) {
1156 /* Check if the remaining data fits into current packet. */
1157 copy = (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len;
1158 if (copy < length)
1159 copy = maxfraglen - skb->len;
1160
1161 if (copy <= 0) {
1162 char *data;
1163 unsigned int datalen;
1164 unsigned int fraglen;
1165 unsigned int fraggap;
1166 unsigned int alloclen;
1167 struct sk_buff *skb_prev;
1168 alloc_new_skb:
1169 skb_prev = skb;
1170
1171 /* There's no room in the current skb */
1172 if (skb_prev)
1173 fraggap = skb_prev->len - maxfraglen;
1174 else
1175 fraggap = 0;
1176
1177 /*
1178 * If remaining data exceeds the mtu,
1179 * we know we need more fragment(s).
1180 */
1181 datalen = length + fraggap;
1182 if (datalen > (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen)
1183 datalen = maxfraglen - fragheaderlen;
1184
1185 fraglen = datalen + fragheaderlen;
1186 if ((flags & MSG_MORE) &&
1187 !(rt->u.dst.dev->features&NETIF_F_SG))
1188 alloclen = mtu;
1189 else
1190 alloclen = datalen + fragheaderlen;
1191
1192 /*
1193 * The last fragment gets additional space at tail.
1194 * Note: we overallocate on fragments with MSG_MODE
1195 * because we have no idea if we're the last one.
1196 */
1197 if (datalen == length + fraggap)
1198 alloclen += rt->u.dst.trailer_len;
1199
1200 /*
1201 * We just reserve space for fragment header.
1202 * Note: this may be overallocation if the message
1203 * (without MSG_MORE) fits into the MTU.
1204 */
1205 alloclen += sizeof(struct frag_hdr);
1206
1207 if (transhdrlen) {
1208 skb = sock_alloc_send_skb(sk,
1209 alloclen + hh_len,
1210 (flags & MSG_DONTWAIT), &err);
1211 } else {
1212 skb = NULL;
1213 if (atomic_read(&sk->sk_wmem_alloc) <=
1214 2 * sk->sk_sndbuf)
1215 skb = sock_wmalloc(sk,
1216 alloclen + hh_len, 1,
1217 sk->sk_allocation);
1218 if (unlikely(skb == NULL))
1219 err = -ENOBUFS;
1220 }
1221 if (skb == NULL)
1222 goto error;
1223 /*
1224 * Fill in the control structures
1225 */
1226 skb->ip_summed = csummode;
1227 skb->csum = 0;
1228 /* reserve for fragmentation */
1229 skb_reserve(skb, hh_len+sizeof(struct frag_hdr));
1230
1231 /*
1232 * Find where to start putting bytes
1233 */
1234 data = skb_put(skb, fraglen);
1235 skb_set_network_header(skb, exthdrlen);
1236 data += fragheaderlen;
1237 skb->transport_header = (skb->network_header +
1238 fragheaderlen);
1239 if (fraggap) {
1240 skb->csum = skb_copy_and_csum_bits(
1241 skb_prev, maxfraglen,
1242 data + transhdrlen, fraggap, 0);
1243 skb_prev->csum = csum_sub(skb_prev->csum,
1244 skb->csum);
1245 data += fraggap;
1246 pskb_trim_unique(skb_prev, maxfraglen);
1247 }
1248 copy = datalen - transhdrlen - fraggap;
1249 if (copy < 0) {
1250 err = -EINVAL;
1251 kfree_skb(skb);
1252 goto error;
1253 } else if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) {
1254 err = -EFAULT;
1255 kfree_skb(skb);
1256 goto error;
1257 }
1258
1259 offset += copy;
1260 length -= datalen - fraggap;
1261 transhdrlen = 0;
1262 exthdrlen = 0;
1263 csummode = CHECKSUM_NONE;
1264
1265 /*
1266 * Put the packet on the pending queue
1267 */
1268 __skb_queue_tail(&sk->sk_write_queue, skb);
1269 continue;
1270 }
1271
1272 if (copy > length)
1273 copy = length;
1274
1275 if (!(rt->u.dst.dev->features&NETIF_F_SG)) {
1276 unsigned int off;
1277
1278 off = skb->len;
1279 if (getfrag(from, skb_put(skb, copy),
1280 offset, copy, off, skb) < 0) {
1281 __skb_trim(skb, off);
1282 err = -EFAULT;
1283 goto error;
1284 }
1285 } else {
1286 int i = skb_shinfo(skb)->nr_frags;
1287 skb_frag_t *frag = &skb_shinfo(skb)->frags[i-1];
1288 struct page *page = sk->sk_sndmsg_page;
1289 int off = sk->sk_sndmsg_off;
1290 unsigned int left;
1291
1292 if (page && (left = PAGE_SIZE - off) > 0) {
1293 if (copy >= left)
1294 copy = left;
1295 if (page != frag->page) {
1296 if (i == MAX_SKB_FRAGS) {
1297 err = -EMSGSIZE;
1298 goto error;
1299 }
1300 get_page(page);
1301 skb_fill_page_desc(skb, i, page, sk->sk_sndmsg_off, 0);
1302 frag = &skb_shinfo(skb)->frags[i];
1303 }
1304 } else if(i < MAX_SKB_FRAGS) {
1305 if (copy > PAGE_SIZE)
1306 copy = PAGE_SIZE;
1307 page = alloc_pages(sk->sk_allocation, 0);
1308 if (page == NULL) {
1309 err = -ENOMEM;
1310 goto error;
1311 }
1312 sk->sk_sndmsg_page = page;
1313 sk->sk_sndmsg_off = 0;
1314
1315 skb_fill_page_desc(skb, i, page, 0, 0);
1316 frag = &skb_shinfo(skb)->frags[i];
1317 skb->truesize += PAGE_SIZE;
1318 atomic_add(PAGE_SIZE, &sk->sk_wmem_alloc);
1319 } else {
1320 err = -EMSGSIZE;
1321 goto error;
1322 }
1323 if (getfrag(from, page_address(frag->page)+frag->page_offset+frag->size, offset, copy, skb->len, skb) < 0) {
1324 err = -EFAULT;
1325 goto error;
1326 }
1327 sk->sk_sndmsg_off += copy;
1328 frag->size += copy;
1329 skb->len += copy;
1330 skb->data_len += copy;
1331 }
1332 offset += copy;
1333 length -= copy;
1334 }
1335 return 0;
1336 error:
1337 inet->cork.length -= length;
1338 IP6_INC_STATS(rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS);
1339 return err;
1340 }
1341
1342 int ip6_push_pending_frames(struct sock *sk)
1343 {
1344 struct sk_buff *skb, *tmp_skb;
1345 struct sk_buff **tail_skb;
1346 struct in6_addr final_dst_buf, *final_dst = &final_dst_buf;
1347 struct inet_sock *inet = inet_sk(sk);
1348 struct ipv6_pinfo *np = inet6_sk(sk);
1349 struct ipv6hdr *hdr;
1350 struct ipv6_txoptions *opt = np->cork.opt;
1351 struct rt6_info *rt = np->cork.rt;
1352 struct flowi *fl = &inet->cork.fl;
1353 unsigned char proto = fl->proto;
1354 int err = 0;
1355
1356 if ((skb = __skb_dequeue(&sk->sk_write_queue)) == NULL)
1357 goto out;
1358 tail_skb = &(skb_shinfo(skb)->frag_list);
1359
1360 /* move skb->data to ip header from ext header */
1361 if (skb->data < skb_network_header(skb))
1362 __skb_pull(skb, skb_network_offset(skb));
1363 while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) {
1364 __skb_pull(tmp_skb, skb_network_header_len(skb));
1365 *tail_skb = tmp_skb;
1366 tail_skb = &(tmp_skb->next);
1367 skb->len += tmp_skb->len;
1368 skb->data_len += tmp_skb->len;
1369 skb->truesize += tmp_skb->truesize;
1370 __sock_put(tmp_skb->sk);
1371 tmp_skb->destructor = NULL;
1372 tmp_skb->sk = NULL;
1373 }
1374
1375 ipv6_addr_copy(final_dst, &fl->fl6_dst);
1376 __skb_pull(skb, skb_network_header_len(skb));
1377 if (opt && opt->opt_flen)
1378 ipv6_push_frag_opts(skb, opt, &proto);
1379 if (opt && opt->opt_nflen)
1380 ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst);
1381
1382 skb_push(skb, sizeof(struct ipv6hdr));
1383 skb_reset_network_header(skb);
1384 hdr = ipv6_hdr(skb);
1385
1386 *(__be32*)hdr = fl->fl6_flowlabel |
1387 htonl(0x60000000 | ((int)np->cork.tclass << 20));
1388
1389 if (skb->len <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN)
1390 hdr->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
1391 else
1392 hdr->payload_len = 0;
1393 hdr->hop_limit = np->cork.hop_limit;
1394 hdr->nexthdr = proto;
1395 ipv6_addr_copy(&hdr->saddr, &fl->fl6_src);
1396 ipv6_addr_copy(&hdr->daddr, final_dst);
1397
1398 skb->priority = sk->sk_priority;
1399
1400 skb->dst = dst_clone(&rt->u.dst);
1401 IP6_INC_STATS(rt->rt6i_idev, IPSTATS_MIB_OUTREQUESTS);
1402 if (proto == IPPROTO_ICMPV6) {
1403 struct inet6_dev *idev = ip6_dst_idev(skb->dst);
1404
1405 ICMP6MSGOUT_INC_STATS_BH(idev, icmp6_hdr(skb)->icmp6_type);
1406 ICMP6_INC_STATS_BH(idev, ICMP6_MIB_OUTMSGS);
1407 }
1408
1409 err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, skb->dst->dev, dst_output);
1410 if (err) {
1411 if (err > 0)
1412 err = np->recverr ? net_xmit_errno(err) : 0;
1413 if (err)
1414 goto error;
1415 }
1416
1417 out:
1418 inet->cork.flags &= ~IPCORK_OPT;
1419 kfree(np->cork.opt);
1420 np->cork.opt = NULL;
1421 if (np->cork.rt) {
1422 dst_release(&np->cork.rt->u.dst);
1423 np->cork.rt = NULL;
1424 inet->cork.flags &= ~IPCORK_ALLFRAG;
1425 }
1426 memset(&inet->cork.fl, 0, sizeof(inet->cork.fl));
1427 return err;
1428 error:
1429 goto out;
1430 }
1431
1432 void ip6_flush_pending_frames(struct sock *sk)
1433 {
1434 struct inet_sock *inet = inet_sk(sk);
1435 struct ipv6_pinfo *np = inet6_sk(sk);
1436 struct sk_buff *skb;
1437
1438 while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) {
1439 if (skb->dst)
1440 IP6_INC_STATS(ip6_dst_idev(skb->dst),
1441 IPSTATS_MIB_OUTDISCARDS);
1442 kfree_skb(skb);
1443 }
1444
1445 inet->cork.flags &= ~IPCORK_OPT;
1446
1447 kfree(np->cork.opt);
1448 np->cork.opt = NULL;
1449 if (np->cork.rt) {
1450 dst_release(&np->cork.rt->u.dst);
1451 np->cork.rt = NULL;
1452 inet->cork.flags &= ~IPCORK_ALLFRAG;
1453 }
1454 memset(&inet->cork.fl, 0, sizeof(inet->cork.fl));
1455 }