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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/dlm
[deliverable/linux.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 * Based on linux/net/ipv4/ip_output.c
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * as published by the Free Software Foundation; either version
13 * 2 of the License, or (at your option) any later version.
14 *
15 * Changes:
16 * A.N.Kuznetsov : airthmetics in fragmentation.
17 * extension headers are implemented.
18 * route changes now work.
19 * ip6_forward does not confuse sniffers.
20 * etc.
21 *
22 * H. von Brand : Added missing #include <linux/string.h>
23 * Imran Patel : frag id should be in NBO
24 * Kazunori MIYAZAWA @USAGI
25 * : add ip6_append_data and related functions
26 * for datagram xmit
27 */
28
29 #include <linux/errno.h>
30 #include <linux/kernel.h>
31 #include <linux/string.h>
32 #include <linux/socket.h>
33 #include <linux/net.h>
34 #include <linux/netdevice.h>
35 #include <linux/if_arp.h>
36 #include <linux/in6.h>
37 #include <linux/tcp.h>
38 #include <linux/route.h>
39 #include <linux/module.h>
40
41 #include <linux/netfilter.h>
42 #include <linux/netfilter_ipv6.h>
43
44 #include <net/sock.h>
45 #include <net/snmp.h>
46
47 #include <net/ipv6.h>
48 #include <net/ndisc.h>
49 #include <net/protocol.h>
50 #include <net/ip6_route.h>
51 #include <net/addrconf.h>
52 #include <net/rawv6.h>
53 #include <net/icmp.h>
54 #include <net/xfrm.h>
55 #include <net/checksum.h>
56 #include <linux/mroute6.h>
57
58 static int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *));
59
60 static __inline__ void ipv6_select_ident(struct sk_buff *skb, struct frag_hdr *fhdr)
61 {
62 static u32 ipv6_fragmentation_id = 1;
63 static DEFINE_SPINLOCK(ip6_id_lock);
64
65 spin_lock_bh(&ip6_id_lock);
66 fhdr->identification = htonl(ipv6_fragmentation_id);
67 if (++ipv6_fragmentation_id == 0)
68 ipv6_fragmentation_id = 1;
69 spin_unlock_bh(&ip6_id_lock);
70 }
71
72 int __ip6_local_out(struct sk_buff *skb)
73 {
74 int len;
75
76 len = skb->len - sizeof(struct ipv6hdr);
77 if (len > IPV6_MAXPLEN)
78 len = 0;
79 ipv6_hdr(skb)->payload_len = htons(len);
80
81 return nf_hook(PF_INET6, NF_INET_LOCAL_OUT, skb, NULL, skb_dst(skb)->dev,
82 dst_output);
83 }
84
85 int ip6_local_out(struct sk_buff *skb)
86 {
87 int err;
88
89 err = __ip6_local_out(skb);
90 if (likely(err == 1))
91 err = dst_output(skb);
92
93 return err;
94 }
95 EXPORT_SYMBOL_GPL(ip6_local_out);
96
97 static int ip6_output_finish(struct sk_buff *skb)
98 {
99 struct dst_entry *dst = skb_dst(skb);
100
101 if (dst->hh)
102 return neigh_hh_output(dst->hh, skb);
103 else if (dst->neighbour)
104 return dst->neighbour->output(skb);
105
106 IP6_INC_STATS_BH(dev_net(dst->dev),
107 ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
108 kfree_skb(skb);
109 return -EINVAL;
110
111 }
112
113 /* dev_loopback_xmit for use with netfilter. */
114 static int ip6_dev_loopback_xmit(struct sk_buff *newskb)
115 {
116 skb_reset_mac_header(newskb);
117 __skb_pull(newskb, skb_network_offset(newskb));
118 newskb->pkt_type = PACKET_LOOPBACK;
119 newskb->ip_summed = CHECKSUM_UNNECESSARY;
120 WARN_ON(!skb_dst(newskb));
121
122 netif_rx(newskb);
123 return 0;
124 }
125
126
127 static int ip6_output2(struct sk_buff *skb)
128 {
129 struct dst_entry *dst = skb_dst(skb);
130 struct net_device *dev = dst->dev;
131
132 skb->protocol = htons(ETH_P_IPV6);
133 skb->dev = dev;
134
135 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) {
136 struct ipv6_pinfo* np = skb->sk ? inet6_sk(skb->sk) : NULL;
137 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
138
139 if (!(dev->flags & IFF_LOOPBACK) && (!np || np->mc_loop) &&
140 ((mroute6_socket(dev_net(dev)) &&
141 !(IP6CB(skb)->flags & IP6SKB_FORWARDED)) ||
142 ipv6_chk_mcast_addr(dev, &ipv6_hdr(skb)->daddr,
143 &ipv6_hdr(skb)->saddr))) {
144 struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC);
145
146 /* Do not check for IFF_ALLMULTI; multicast routing
147 is not supported in any case.
148 */
149 if (newskb)
150 NF_HOOK(PF_INET6, NF_INET_POST_ROUTING, newskb,
151 NULL, newskb->dev,
152 ip6_dev_loopback_xmit);
153
154 if (ipv6_hdr(skb)->hop_limit == 0) {
155 IP6_INC_STATS(dev_net(dev), idev,
156 IPSTATS_MIB_OUTDISCARDS);
157 kfree_skb(skb);
158 return 0;
159 }
160 }
161
162 IP6_UPD_PO_STATS(dev_net(dev), idev, IPSTATS_MIB_OUTMCAST,
163 skb->len);
164 }
165
166 return NF_HOOK(PF_INET6, NF_INET_POST_ROUTING, skb, NULL, skb->dev,
167 ip6_output_finish);
168 }
169
170 static inline int ip6_skb_dst_mtu(struct sk_buff *skb)
171 {
172 struct ipv6_pinfo *np = skb->sk ? inet6_sk(skb->sk) : NULL;
173
174 return (np && np->pmtudisc == IPV6_PMTUDISC_PROBE) ?
175 skb_dst(skb)->dev->mtu : dst_mtu(skb_dst(skb));
176 }
177
178 int ip6_output(struct sk_buff *skb)
179 {
180 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
181 if (unlikely(idev->cnf.disable_ipv6)) {
182 IP6_INC_STATS(dev_net(skb_dst(skb)->dev), idev,
183 IPSTATS_MIB_OUTDISCARDS);
184 kfree_skb(skb);
185 return 0;
186 }
187
188 if ((skb->len > ip6_skb_dst_mtu(skb) && !skb_is_gso(skb)) ||
189 dst_allfrag(skb_dst(skb)))
190 return ip6_fragment(skb, ip6_output2);
191 else
192 return ip6_output2(skb);
193 }
194
195 /*
196 * xmit an sk_buff (used by TCP)
197 */
198
199 int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl,
200 struct ipv6_txoptions *opt, int ipfragok)
201 {
202 struct net *net = sock_net(sk);
203 struct ipv6_pinfo *np = inet6_sk(sk);
204 struct in6_addr *first_hop = &fl->fl6_dst;
205 struct dst_entry *dst = skb_dst(skb);
206 struct ipv6hdr *hdr;
207 u8 proto = fl->proto;
208 int seg_len = skb->len;
209 int hlimit, tclass;
210 u32 mtu;
211
212 if (opt) {
213 unsigned int head_room;
214
215 /* First: exthdrs may take lots of space (~8K for now)
216 MAX_HEADER is not enough.
217 */
218 head_room = opt->opt_nflen + opt->opt_flen;
219 seg_len += head_room;
220 head_room += sizeof(struct ipv6hdr) + LL_RESERVED_SPACE(dst->dev);
221
222 if (skb_headroom(skb) < head_room) {
223 struct sk_buff *skb2 = skb_realloc_headroom(skb, head_room);
224 if (skb2 == NULL) {
225 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
226 IPSTATS_MIB_OUTDISCARDS);
227 kfree_skb(skb);
228 return -ENOBUFS;
229 }
230 kfree_skb(skb);
231 skb = skb2;
232 if (sk)
233 skb_set_owner_w(skb, sk);
234 }
235 if (opt->opt_flen)
236 ipv6_push_frag_opts(skb, opt, &proto);
237 if (opt->opt_nflen)
238 ipv6_push_nfrag_opts(skb, opt, &proto, &first_hop);
239 }
240
241 skb_push(skb, sizeof(struct ipv6hdr));
242 skb_reset_network_header(skb);
243 hdr = ipv6_hdr(skb);
244
245 /* Allow local fragmentation. */
246 if (ipfragok)
247 skb->local_df = 1;
248
249 /*
250 * Fill in the IPv6 header
251 */
252
253 hlimit = -1;
254 if (np)
255 hlimit = np->hop_limit;
256 if (hlimit < 0)
257 hlimit = ip6_dst_hoplimit(dst);
258
259 tclass = -1;
260 if (np)
261 tclass = np->tclass;
262 if (tclass < 0)
263 tclass = 0;
264
265 *(__be32 *)hdr = htonl(0x60000000 | (tclass << 20)) | fl->fl6_flowlabel;
266
267 hdr->payload_len = htons(seg_len);
268 hdr->nexthdr = proto;
269 hdr->hop_limit = hlimit;
270
271 ipv6_addr_copy(&hdr->saddr, &fl->fl6_src);
272 ipv6_addr_copy(&hdr->daddr, first_hop);
273
274 skb->priority = sk->sk_priority;
275 skb->mark = sk->sk_mark;
276
277 mtu = dst_mtu(dst);
278 if ((skb->len <= mtu) || skb->local_df || skb_is_gso(skb)) {
279 IP6_UPD_PO_STATS(net, ip6_dst_idev(skb_dst(skb)),
280 IPSTATS_MIB_OUT, skb->len);
281 return NF_HOOK(PF_INET6, NF_INET_LOCAL_OUT, skb, NULL, dst->dev,
282 dst_output);
283 }
284
285 if (net_ratelimit())
286 printk(KERN_DEBUG "IPv6: sending pkt_too_big to self\n");
287 skb->dev = dst->dev;
288 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, skb->dev);
289 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_FRAGFAILS);
290 kfree_skb(skb);
291 return -EMSGSIZE;
292 }
293
294 EXPORT_SYMBOL(ip6_xmit);
295
296 /*
297 * To avoid extra problems ND packets are send through this
298 * routine. It's code duplication but I really want to avoid
299 * extra checks since ipv6_build_header is used by TCP (which
300 * is for us performance critical)
301 */
302
303 int ip6_nd_hdr(struct sock *sk, struct sk_buff *skb, struct net_device *dev,
304 const struct in6_addr *saddr, const struct in6_addr *daddr,
305 int proto, int len)
306 {
307 struct ipv6_pinfo *np = inet6_sk(sk);
308 struct ipv6hdr *hdr;
309 int totlen;
310
311 skb->protocol = htons(ETH_P_IPV6);
312 skb->dev = dev;
313
314 totlen = len + sizeof(struct ipv6hdr);
315
316 skb_reset_network_header(skb);
317 skb_put(skb, sizeof(struct ipv6hdr));
318 hdr = ipv6_hdr(skb);
319
320 *(__be32*)hdr = htonl(0x60000000);
321
322 hdr->payload_len = htons(len);
323 hdr->nexthdr = proto;
324 hdr->hop_limit = np->hop_limit;
325
326 ipv6_addr_copy(&hdr->saddr, saddr);
327 ipv6_addr_copy(&hdr->daddr, daddr);
328
329 return 0;
330 }
331
332 static int ip6_call_ra_chain(struct sk_buff *skb, int sel)
333 {
334 struct ip6_ra_chain *ra;
335 struct sock *last = NULL;
336
337 read_lock(&ip6_ra_lock);
338 for (ra = ip6_ra_chain; ra; ra = ra->next) {
339 struct sock *sk = ra->sk;
340 if (sk && ra->sel == sel &&
341 (!sk->sk_bound_dev_if ||
342 sk->sk_bound_dev_if == skb->dev->ifindex)) {
343 if (last) {
344 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
345 if (skb2)
346 rawv6_rcv(last, skb2);
347 }
348 last = sk;
349 }
350 }
351
352 if (last) {
353 rawv6_rcv(last, skb);
354 read_unlock(&ip6_ra_lock);
355 return 1;
356 }
357 read_unlock(&ip6_ra_lock);
358 return 0;
359 }
360
361 static int ip6_forward_proxy_check(struct sk_buff *skb)
362 {
363 struct ipv6hdr *hdr = ipv6_hdr(skb);
364 u8 nexthdr = hdr->nexthdr;
365 int offset;
366
367 if (ipv6_ext_hdr(nexthdr)) {
368 offset = ipv6_skip_exthdr(skb, sizeof(*hdr), &nexthdr);
369 if (offset < 0)
370 return 0;
371 } else
372 offset = sizeof(struct ipv6hdr);
373
374 if (nexthdr == IPPROTO_ICMPV6) {
375 struct icmp6hdr *icmp6;
376
377 if (!pskb_may_pull(skb, (skb_network_header(skb) +
378 offset + 1 - skb->data)))
379 return 0;
380
381 icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset);
382
383 switch (icmp6->icmp6_type) {
384 case NDISC_ROUTER_SOLICITATION:
385 case NDISC_ROUTER_ADVERTISEMENT:
386 case NDISC_NEIGHBOUR_SOLICITATION:
387 case NDISC_NEIGHBOUR_ADVERTISEMENT:
388 case NDISC_REDIRECT:
389 /* For reaction involving unicast neighbor discovery
390 * message destined to the proxied address, pass it to
391 * input function.
392 */
393 return 1;
394 default:
395 break;
396 }
397 }
398
399 /*
400 * The proxying router can't forward traffic sent to a link-local
401 * address, so signal the sender and discard the packet. This
402 * behavior is clarified by the MIPv6 specification.
403 */
404 if (ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) {
405 dst_link_failure(skb);
406 return -1;
407 }
408
409 return 0;
410 }
411
412 static inline int ip6_forward_finish(struct sk_buff *skb)
413 {
414 return dst_output(skb);
415 }
416
417 int ip6_forward(struct sk_buff *skb)
418 {
419 struct dst_entry *dst = skb_dst(skb);
420 struct ipv6hdr *hdr = ipv6_hdr(skb);
421 struct inet6_skb_parm *opt = IP6CB(skb);
422 struct net *net = dev_net(dst->dev);
423
424 if (net->ipv6.devconf_all->forwarding == 0)
425 goto error;
426
427 if (skb_warn_if_lro(skb))
428 goto drop;
429
430 if (!xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) {
431 IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS);
432 goto drop;
433 }
434
435 skb_forward_csum(skb);
436
437 /*
438 * We DO NOT make any processing on
439 * RA packets, pushing them to user level AS IS
440 * without ane WARRANTY that application will be able
441 * to interpret them. The reason is that we
442 * cannot make anything clever here.
443 *
444 * We are not end-node, so that if packet contains
445 * AH/ESP, we cannot make anything.
446 * Defragmentation also would be mistake, RA packets
447 * cannot be fragmented, because there is no warranty
448 * that different fragments will go along one path. --ANK
449 */
450 if (opt->ra) {
451 u8 *ptr = skb_network_header(skb) + opt->ra;
452 if (ip6_call_ra_chain(skb, (ptr[2]<<8) + ptr[3]))
453 return 0;
454 }
455
456 /*
457 * check and decrement ttl
458 */
459 if (hdr->hop_limit <= 1) {
460 /* Force OUTPUT device used as source address */
461 skb->dev = dst->dev;
462 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
463 0, skb->dev);
464 IP6_INC_STATS_BH(net,
465 ip6_dst_idev(dst), IPSTATS_MIB_INHDRERRORS);
466
467 kfree_skb(skb);
468 return -ETIMEDOUT;
469 }
470
471 /* XXX: idev->cnf.proxy_ndp? */
472 if (net->ipv6.devconf_all->proxy_ndp &&
473 pneigh_lookup(&nd_tbl, net, &hdr->daddr, skb->dev, 0)) {
474 int proxied = ip6_forward_proxy_check(skb);
475 if (proxied > 0)
476 return ip6_input(skb);
477 else if (proxied < 0) {
478 IP6_INC_STATS(net, ip6_dst_idev(dst),
479 IPSTATS_MIB_INDISCARDS);
480 goto drop;
481 }
482 }
483
484 if (!xfrm6_route_forward(skb)) {
485 IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS);
486 goto drop;
487 }
488 dst = skb_dst(skb);
489
490 /* IPv6 specs say nothing about it, but it is clear that we cannot
491 send redirects to source routed frames.
492 We don't send redirects to frames decapsulated from IPsec.
493 */
494 if (skb->dev == dst->dev && dst->neighbour && opt->srcrt == 0 &&
495 !skb_sec_path(skb)) {
496 struct in6_addr *target = NULL;
497 struct rt6_info *rt;
498 struct neighbour *n = dst->neighbour;
499
500 /*
501 * incoming and outgoing devices are the same
502 * send a redirect.
503 */
504
505 rt = (struct rt6_info *) dst;
506 if ((rt->rt6i_flags & RTF_GATEWAY))
507 target = (struct in6_addr*)&n->primary_key;
508 else
509 target = &hdr->daddr;
510
511 /* Limit redirects both by destination (here)
512 and by source (inside ndisc_send_redirect)
513 */
514 if (xrlim_allow(dst, 1*HZ))
515 ndisc_send_redirect(skb, n, target);
516 } else {
517 int addrtype = ipv6_addr_type(&hdr->saddr);
518
519 /* This check is security critical. */
520 if (addrtype == IPV6_ADDR_ANY ||
521 addrtype & (IPV6_ADDR_MULTICAST | IPV6_ADDR_LOOPBACK))
522 goto error;
523 if (addrtype & IPV6_ADDR_LINKLOCAL) {
524 icmpv6_send(skb, ICMPV6_DEST_UNREACH,
525 ICMPV6_NOT_NEIGHBOUR, 0, skb->dev);
526 goto error;
527 }
528 }
529
530 if (skb->len > dst_mtu(dst)) {
531 /* Again, force OUTPUT device used as source address */
532 skb->dev = dst->dev;
533 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, dst_mtu(dst), skb->dev);
534 IP6_INC_STATS_BH(net,
535 ip6_dst_idev(dst), IPSTATS_MIB_INTOOBIGERRORS);
536 IP6_INC_STATS_BH(net,
537 ip6_dst_idev(dst), IPSTATS_MIB_FRAGFAILS);
538 kfree_skb(skb);
539 return -EMSGSIZE;
540 }
541
542 if (skb_cow(skb, dst->dev->hard_header_len)) {
543 IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTDISCARDS);
544 goto drop;
545 }
546
547 hdr = ipv6_hdr(skb);
548
549 /* Mangling hops number delayed to point after skb COW */
550
551 hdr->hop_limit--;
552
553 IP6_INC_STATS_BH(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTFORWDATAGRAMS);
554 return NF_HOOK(PF_INET6, NF_INET_FORWARD, skb, skb->dev, dst->dev,
555 ip6_forward_finish);
556
557 error:
558 IP6_INC_STATS_BH(net, ip6_dst_idev(dst), IPSTATS_MIB_INADDRERRORS);
559 drop:
560 kfree_skb(skb);
561 return -EINVAL;
562 }
563
564 static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from)
565 {
566 to->pkt_type = from->pkt_type;
567 to->priority = from->priority;
568 to->protocol = from->protocol;
569 skb_dst_drop(to);
570 skb_dst_set(to, dst_clone(skb_dst(from)));
571 to->dev = from->dev;
572 to->mark = from->mark;
573
574 #ifdef CONFIG_NET_SCHED
575 to->tc_index = from->tc_index;
576 #endif
577 nf_copy(to, from);
578 #if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \
579 defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE)
580 to->nf_trace = from->nf_trace;
581 #endif
582 skb_copy_secmark(to, from);
583 }
584
585 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr)
586 {
587 u16 offset = sizeof(struct ipv6hdr);
588 struct ipv6_opt_hdr *exthdr =
589 (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
590 unsigned int packet_len = skb->tail - skb->network_header;
591 int found_rhdr = 0;
592 *nexthdr = &ipv6_hdr(skb)->nexthdr;
593
594 while (offset + 1 <= packet_len) {
595
596 switch (**nexthdr) {
597
598 case NEXTHDR_HOP:
599 break;
600 case NEXTHDR_ROUTING:
601 found_rhdr = 1;
602 break;
603 case NEXTHDR_DEST:
604 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
605 if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
606 break;
607 #endif
608 if (found_rhdr)
609 return offset;
610 break;
611 default :
612 return offset;
613 }
614
615 offset += ipv6_optlen(exthdr);
616 *nexthdr = &exthdr->nexthdr;
617 exthdr = (struct ipv6_opt_hdr *)(skb_network_header(skb) +
618 offset);
619 }
620
621 return offset;
622 }
623
624 static int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *))
625 {
626 struct sk_buff *frag;
627 struct rt6_info *rt = (struct rt6_info*)skb_dst(skb);
628 struct ipv6_pinfo *np = skb->sk ? inet6_sk(skb->sk) : NULL;
629 struct ipv6hdr *tmp_hdr;
630 struct frag_hdr *fh;
631 unsigned int mtu, hlen, left, len;
632 __be32 frag_id = 0;
633 int ptr, offset = 0, err=0;
634 u8 *prevhdr, nexthdr = 0;
635 struct net *net = dev_net(skb_dst(skb)->dev);
636
637 hlen = ip6_find_1stfragopt(skb, &prevhdr);
638 nexthdr = *prevhdr;
639
640 mtu = ip6_skb_dst_mtu(skb);
641
642 /* We must not fragment if the socket is set to force MTU discovery
643 * or if the skb it not generated by a local socket. (This last
644 * check should be redundant, but it's free.)
645 */
646 if (!skb->local_df) {
647 skb->dev = skb_dst(skb)->dev;
648 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, skb->dev);
649 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
650 IPSTATS_MIB_FRAGFAILS);
651 kfree_skb(skb);
652 return -EMSGSIZE;
653 }
654
655 if (np && np->frag_size < mtu) {
656 if (np->frag_size)
657 mtu = np->frag_size;
658 }
659 mtu -= hlen + sizeof(struct frag_hdr);
660
661 if (skb_has_frags(skb)) {
662 int first_len = skb_pagelen(skb);
663 int truesizes = 0;
664
665 if (first_len - hlen > mtu ||
666 ((first_len - hlen) & 7) ||
667 skb_cloned(skb))
668 goto slow_path;
669
670 skb_walk_frags(skb, frag) {
671 /* Correct geometry. */
672 if (frag->len > mtu ||
673 ((frag->len & 7) && frag->next) ||
674 skb_headroom(frag) < hlen)
675 goto slow_path;
676
677 /* Partially cloned skb? */
678 if (skb_shared(frag))
679 goto slow_path;
680
681 BUG_ON(frag->sk);
682 if (skb->sk) {
683 frag->sk = skb->sk;
684 frag->destructor = sock_wfree;
685 truesizes += frag->truesize;
686 }
687 }
688
689 err = 0;
690 offset = 0;
691 frag = skb_shinfo(skb)->frag_list;
692 skb_frag_list_init(skb);
693 /* BUILD HEADER */
694
695 *prevhdr = NEXTHDR_FRAGMENT;
696 tmp_hdr = kmemdup(skb_network_header(skb), hlen, GFP_ATOMIC);
697 if (!tmp_hdr) {
698 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
699 IPSTATS_MIB_FRAGFAILS);
700 return -ENOMEM;
701 }
702
703 __skb_pull(skb, hlen);
704 fh = (struct frag_hdr*)__skb_push(skb, sizeof(struct frag_hdr));
705 __skb_push(skb, hlen);
706 skb_reset_network_header(skb);
707 memcpy(skb_network_header(skb), tmp_hdr, hlen);
708
709 ipv6_select_ident(skb, fh);
710 fh->nexthdr = nexthdr;
711 fh->reserved = 0;
712 fh->frag_off = htons(IP6_MF);
713 frag_id = fh->identification;
714
715 first_len = skb_pagelen(skb);
716 skb->data_len = first_len - skb_headlen(skb);
717 skb->truesize -= truesizes;
718 skb->len = first_len;
719 ipv6_hdr(skb)->payload_len = htons(first_len -
720 sizeof(struct ipv6hdr));
721
722 dst_hold(&rt->u.dst);
723
724 for (;;) {
725 /* Prepare header of the next frame,
726 * before previous one went down. */
727 if (frag) {
728 frag->ip_summed = CHECKSUM_NONE;
729 skb_reset_transport_header(frag);
730 fh = (struct frag_hdr*)__skb_push(frag, sizeof(struct frag_hdr));
731 __skb_push(frag, hlen);
732 skb_reset_network_header(frag);
733 memcpy(skb_network_header(frag), tmp_hdr,
734 hlen);
735 offset += skb->len - hlen - sizeof(struct frag_hdr);
736 fh->nexthdr = nexthdr;
737 fh->reserved = 0;
738 fh->frag_off = htons(offset);
739 if (frag->next != NULL)
740 fh->frag_off |= htons(IP6_MF);
741 fh->identification = frag_id;
742 ipv6_hdr(frag)->payload_len =
743 htons(frag->len -
744 sizeof(struct ipv6hdr));
745 ip6_copy_metadata(frag, skb);
746 }
747
748 err = output(skb);
749 if(!err)
750 IP6_INC_STATS(net, ip6_dst_idev(&rt->u.dst),
751 IPSTATS_MIB_FRAGCREATES);
752
753 if (err || !frag)
754 break;
755
756 skb = frag;
757 frag = skb->next;
758 skb->next = NULL;
759 }
760
761 kfree(tmp_hdr);
762
763 if (err == 0) {
764 IP6_INC_STATS(net, ip6_dst_idev(&rt->u.dst),
765 IPSTATS_MIB_FRAGOKS);
766 dst_release(&rt->u.dst);
767 return 0;
768 }
769
770 while (frag) {
771 skb = frag->next;
772 kfree_skb(frag);
773 frag = skb;
774 }
775
776 IP6_INC_STATS(net, ip6_dst_idev(&rt->u.dst),
777 IPSTATS_MIB_FRAGFAILS);
778 dst_release(&rt->u.dst);
779 return err;
780 }
781
782 slow_path:
783 left = skb->len - hlen; /* Space per frame */
784 ptr = hlen; /* Where to start from */
785
786 /*
787 * Fragment the datagram.
788 */
789
790 *prevhdr = NEXTHDR_FRAGMENT;
791
792 /*
793 * Keep copying data until we run out.
794 */
795 while(left > 0) {
796 len = left;
797 /* IF: it doesn't fit, use 'mtu' - the data space left */
798 if (len > mtu)
799 len = mtu;
800 /* IF: we are not sending upto and including the packet end
801 then align the next start on an eight byte boundary */
802 if (len < left) {
803 len &= ~7;
804 }
805 /*
806 * Allocate buffer.
807 */
808
809 if ((frag = alloc_skb(len+hlen+sizeof(struct frag_hdr)+LL_ALLOCATED_SPACE(rt->u.dst.dev), GFP_ATOMIC)) == NULL) {
810 NETDEBUG(KERN_INFO "IPv6: frag: no memory for new fragment!\n");
811 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
812 IPSTATS_MIB_FRAGFAILS);
813 err = -ENOMEM;
814 goto fail;
815 }
816
817 /*
818 * Set up data on packet
819 */
820
821 ip6_copy_metadata(frag, skb);
822 skb_reserve(frag, LL_RESERVED_SPACE(rt->u.dst.dev));
823 skb_put(frag, len + hlen + sizeof(struct frag_hdr));
824 skb_reset_network_header(frag);
825 fh = (struct frag_hdr *)(skb_network_header(frag) + hlen);
826 frag->transport_header = (frag->network_header + hlen +
827 sizeof(struct frag_hdr));
828
829 /*
830 * Charge the memory for the fragment to any owner
831 * it might possess
832 */
833 if (skb->sk)
834 skb_set_owner_w(frag, skb->sk);
835
836 /*
837 * Copy the packet header into the new buffer.
838 */
839 skb_copy_from_linear_data(skb, skb_network_header(frag), hlen);
840
841 /*
842 * Build fragment header.
843 */
844 fh->nexthdr = nexthdr;
845 fh->reserved = 0;
846 if (!frag_id) {
847 ipv6_select_ident(skb, fh);
848 frag_id = fh->identification;
849 } else
850 fh->identification = frag_id;
851
852 /*
853 * Copy a block of the IP datagram.
854 */
855 if (skb_copy_bits(skb, ptr, skb_transport_header(frag), len))
856 BUG();
857 left -= len;
858
859 fh->frag_off = htons(offset);
860 if (left > 0)
861 fh->frag_off |= htons(IP6_MF);
862 ipv6_hdr(frag)->payload_len = htons(frag->len -
863 sizeof(struct ipv6hdr));
864
865 ptr += len;
866 offset += len;
867
868 /*
869 * Put this fragment into the sending queue.
870 */
871 err = output(frag);
872 if (err)
873 goto fail;
874
875 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
876 IPSTATS_MIB_FRAGCREATES);
877 }
878 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
879 IPSTATS_MIB_FRAGOKS);
880 kfree_skb(skb);
881 return err;
882
883 fail:
884 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
885 IPSTATS_MIB_FRAGFAILS);
886 kfree_skb(skb);
887 return err;
888 }
889
890 static inline int ip6_rt_check(struct rt6key *rt_key,
891 struct in6_addr *fl_addr,
892 struct in6_addr *addr_cache)
893 {
894 return ((rt_key->plen != 128 || !ipv6_addr_equal(fl_addr, &rt_key->addr)) &&
895 (addr_cache == NULL || !ipv6_addr_equal(fl_addr, addr_cache)));
896 }
897
898 static struct dst_entry *ip6_sk_dst_check(struct sock *sk,
899 struct dst_entry *dst,
900 struct flowi *fl)
901 {
902 struct ipv6_pinfo *np = inet6_sk(sk);
903 struct rt6_info *rt = (struct rt6_info *)dst;
904
905 if (!dst)
906 goto out;
907
908 /* Yes, checking route validity in not connected
909 * case is not very simple. Take into account,
910 * that we do not support routing by source, TOS,
911 * and MSG_DONTROUTE --ANK (980726)
912 *
913 * 1. ip6_rt_check(): If route was host route,
914 * check that cached destination is current.
915 * If it is network route, we still may
916 * check its validity using saved pointer
917 * to the last used address: daddr_cache.
918 * We do not want to save whole address now,
919 * (because main consumer of this service
920 * is tcp, which has not this problem),
921 * so that the last trick works only on connected
922 * sockets.
923 * 2. oif also should be the same.
924 */
925 if (ip6_rt_check(&rt->rt6i_dst, &fl->fl6_dst, np->daddr_cache) ||
926 #ifdef CONFIG_IPV6_SUBTREES
927 ip6_rt_check(&rt->rt6i_src, &fl->fl6_src, np->saddr_cache) ||
928 #endif
929 (fl->oif && fl->oif != dst->dev->ifindex)) {
930 dst_release(dst);
931 dst = NULL;
932 }
933
934 out:
935 return dst;
936 }
937
938 static int ip6_dst_lookup_tail(struct sock *sk,
939 struct dst_entry **dst, struct flowi *fl)
940 {
941 int err;
942 struct net *net = sock_net(sk);
943
944 if (*dst == NULL)
945 *dst = ip6_route_output(net, sk, fl);
946
947 if ((err = (*dst)->error))
948 goto out_err_release;
949
950 if (ipv6_addr_any(&fl->fl6_src)) {
951 err = ipv6_dev_get_saddr(net, ip6_dst_idev(*dst)->dev,
952 &fl->fl6_dst,
953 sk ? inet6_sk(sk)->srcprefs : 0,
954 &fl->fl6_src);
955 if (err)
956 goto out_err_release;
957 }
958
959 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
960 /*
961 * Here if the dst entry we've looked up
962 * has a neighbour entry that is in the INCOMPLETE
963 * state and the src address from the flow is
964 * marked as OPTIMISTIC, we release the found
965 * dst entry and replace it instead with the
966 * dst entry of the nexthop router
967 */
968 if ((*dst)->neighbour && !((*dst)->neighbour->nud_state & NUD_VALID)) {
969 struct inet6_ifaddr *ifp;
970 struct flowi fl_gw;
971 int redirect;
972
973 ifp = ipv6_get_ifaddr(net, &fl->fl6_src,
974 (*dst)->dev, 1);
975
976 redirect = (ifp && ifp->flags & IFA_F_OPTIMISTIC);
977 if (ifp)
978 in6_ifa_put(ifp);
979
980 if (redirect) {
981 /*
982 * We need to get the dst entry for the
983 * default router instead
984 */
985 dst_release(*dst);
986 memcpy(&fl_gw, fl, sizeof(struct flowi));
987 memset(&fl_gw.fl6_dst, 0, sizeof(struct in6_addr));
988 *dst = ip6_route_output(net, sk, &fl_gw);
989 if ((err = (*dst)->error))
990 goto out_err_release;
991 }
992 }
993 #endif
994
995 return 0;
996
997 out_err_release:
998 if (err == -ENETUNREACH)
999 IP6_INC_STATS_BH(net, NULL, IPSTATS_MIB_OUTNOROUTES);
1000 dst_release(*dst);
1001 *dst = NULL;
1002 return err;
1003 }
1004
1005 /**
1006 * ip6_dst_lookup - perform route lookup on flow
1007 * @sk: socket which provides route info
1008 * @dst: pointer to dst_entry * for result
1009 * @fl: flow to lookup
1010 *
1011 * This function performs a route lookup on the given flow.
1012 *
1013 * It returns zero on success, or a standard errno code on error.
1014 */
1015 int ip6_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi *fl)
1016 {
1017 *dst = NULL;
1018 return ip6_dst_lookup_tail(sk, dst, fl);
1019 }
1020 EXPORT_SYMBOL_GPL(ip6_dst_lookup);
1021
1022 /**
1023 * ip6_sk_dst_lookup - perform socket cached route lookup on flow
1024 * @sk: socket which provides the dst cache and route info
1025 * @dst: pointer to dst_entry * for result
1026 * @fl: flow to lookup
1027 *
1028 * This function performs a route lookup on the given flow with the
1029 * possibility of using the cached route in the socket if it is valid.
1030 * It will take the socket dst lock when operating on the dst cache.
1031 * As a result, this function can only be used in process context.
1032 *
1033 * It returns zero on success, or a standard errno code on error.
1034 */
1035 int ip6_sk_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi *fl)
1036 {
1037 *dst = NULL;
1038 if (sk) {
1039 *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie);
1040 *dst = ip6_sk_dst_check(sk, *dst, fl);
1041 }
1042
1043 return ip6_dst_lookup_tail(sk, dst, fl);
1044 }
1045 EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup);
1046
1047 static inline int ip6_ufo_append_data(struct sock *sk,
1048 int getfrag(void *from, char *to, int offset, int len,
1049 int odd, struct sk_buff *skb),
1050 void *from, int length, int hh_len, int fragheaderlen,
1051 int transhdrlen, int mtu,unsigned int flags)
1052
1053 {
1054 struct sk_buff *skb;
1055 int err;
1056
1057 /* There is support for UDP large send offload by network
1058 * device, so create one single skb packet containing complete
1059 * udp datagram
1060 */
1061 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) {
1062 skb = sock_alloc_send_skb(sk,
1063 hh_len + fragheaderlen + transhdrlen + 20,
1064 (flags & MSG_DONTWAIT), &err);
1065 if (skb == NULL)
1066 return -ENOMEM;
1067
1068 /* reserve space for Hardware header */
1069 skb_reserve(skb, hh_len);
1070
1071 /* create space for UDP/IP header */
1072 skb_put(skb,fragheaderlen + transhdrlen);
1073
1074 /* initialize network header pointer */
1075 skb_reset_network_header(skb);
1076
1077 /* initialize protocol header pointer */
1078 skb->transport_header = skb->network_header + fragheaderlen;
1079
1080 skb->ip_summed = CHECKSUM_PARTIAL;
1081 skb->csum = 0;
1082 sk->sk_sndmsg_off = 0;
1083 }
1084
1085 err = skb_append_datato_frags(sk,skb, getfrag, from,
1086 (length - transhdrlen));
1087 if (!err) {
1088 struct frag_hdr fhdr;
1089
1090 /* specify the length of each IP datagram fragment*/
1091 skb_shinfo(skb)->gso_size = mtu - fragheaderlen -
1092 sizeof(struct frag_hdr);
1093 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
1094 ipv6_select_ident(skb, &fhdr);
1095 skb_shinfo(skb)->ip6_frag_id = fhdr.identification;
1096 __skb_queue_tail(&sk->sk_write_queue, skb);
1097
1098 return 0;
1099 }
1100 /* There is not enough support do UPD LSO,
1101 * so follow normal path
1102 */
1103 kfree_skb(skb);
1104
1105 return err;
1106 }
1107
1108 static inline struct ipv6_opt_hdr *ip6_opt_dup(struct ipv6_opt_hdr *src,
1109 gfp_t gfp)
1110 {
1111 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL;
1112 }
1113
1114 static inline struct ipv6_rt_hdr *ip6_rthdr_dup(struct ipv6_rt_hdr *src,
1115 gfp_t gfp)
1116 {
1117 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL;
1118 }
1119
1120 int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
1121 int offset, int len, int odd, struct sk_buff *skb),
1122 void *from, int length, int transhdrlen,
1123 int hlimit, int tclass, struct ipv6_txoptions *opt, struct flowi *fl,
1124 struct rt6_info *rt, unsigned int flags)
1125 {
1126 struct inet_sock *inet = inet_sk(sk);
1127 struct ipv6_pinfo *np = inet6_sk(sk);
1128 struct sk_buff *skb;
1129 unsigned int maxfraglen, fragheaderlen;
1130 int exthdrlen;
1131 int hh_len;
1132 int mtu;
1133 int copy;
1134 int err;
1135 int offset = 0;
1136 int csummode = CHECKSUM_NONE;
1137
1138 if (flags&MSG_PROBE)
1139 return 0;
1140 if (skb_queue_empty(&sk->sk_write_queue)) {
1141 /*
1142 * setup for corking
1143 */
1144 if (opt) {
1145 if (WARN_ON(np->cork.opt))
1146 return -EINVAL;
1147
1148 np->cork.opt = kmalloc(opt->tot_len, sk->sk_allocation);
1149 if (unlikely(np->cork.opt == NULL))
1150 return -ENOBUFS;
1151
1152 np->cork.opt->tot_len = opt->tot_len;
1153 np->cork.opt->opt_flen = opt->opt_flen;
1154 np->cork.opt->opt_nflen = opt->opt_nflen;
1155
1156 np->cork.opt->dst0opt = ip6_opt_dup(opt->dst0opt,
1157 sk->sk_allocation);
1158 if (opt->dst0opt && !np->cork.opt->dst0opt)
1159 return -ENOBUFS;
1160
1161 np->cork.opt->dst1opt = ip6_opt_dup(opt->dst1opt,
1162 sk->sk_allocation);
1163 if (opt->dst1opt && !np->cork.opt->dst1opt)
1164 return -ENOBUFS;
1165
1166 np->cork.opt->hopopt = ip6_opt_dup(opt->hopopt,
1167 sk->sk_allocation);
1168 if (opt->hopopt && !np->cork.opt->hopopt)
1169 return -ENOBUFS;
1170
1171 np->cork.opt->srcrt = ip6_rthdr_dup(opt->srcrt,
1172 sk->sk_allocation);
1173 if (opt->srcrt && !np->cork.opt->srcrt)
1174 return -ENOBUFS;
1175
1176 /* need source address above miyazawa*/
1177 }
1178 dst_hold(&rt->u.dst);
1179 inet->cork.dst = &rt->u.dst;
1180 inet->cork.fl = *fl;
1181 np->cork.hop_limit = hlimit;
1182 np->cork.tclass = tclass;
1183 mtu = np->pmtudisc == IPV6_PMTUDISC_PROBE ?
1184 rt->u.dst.dev->mtu : dst_mtu(rt->u.dst.path);
1185 if (np->frag_size < mtu) {
1186 if (np->frag_size)
1187 mtu = np->frag_size;
1188 }
1189 inet->cork.fragsize = mtu;
1190 if (dst_allfrag(rt->u.dst.path))
1191 inet->cork.flags |= IPCORK_ALLFRAG;
1192 inet->cork.length = 0;
1193 sk->sk_sndmsg_page = NULL;
1194 sk->sk_sndmsg_off = 0;
1195 exthdrlen = rt->u.dst.header_len + (opt ? opt->opt_flen : 0) -
1196 rt->rt6i_nfheader_len;
1197 length += exthdrlen;
1198 transhdrlen += exthdrlen;
1199 } else {
1200 rt = (struct rt6_info *)inet->cork.dst;
1201 fl = &inet->cork.fl;
1202 opt = np->cork.opt;
1203 transhdrlen = 0;
1204 exthdrlen = 0;
1205 mtu = inet->cork.fragsize;
1206 }
1207
1208 hh_len = LL_RESERVED_SPACE(rt->u.dst.dev);
1209
1210 fragheaderlen = sizeof(struct ipv6hdr) + rt->rt6i_nfheader_len +
1211 (opt ? opt->opt_nflen : 0);
1212 maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - sizeof(struct frag_hdr);
1213
1214 if (mtu <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN) {
1215 if (inet->cork.length + length > sizeof(struct ipv6hdr) + IPV6_MAXPLEN - fragheaderlen) {
1216 ipv6_local_error(sk, EMSGSIZE, fl, mtu-exthdrlen);
1217 return -EMSGSIZE;
1218 }
1219 }
1220
1221 /*
1222 * Let's try using as much space as possible.
1223 * Use MTU if total length of the message fits into the MTU.
1224 * Otherwise, we need to reserve fragment header and
1225 * fragment alignment (= 8-15 octects, in total).
1226 *
1227 * Note that we may need to "move" the data from the tail of
1228 * of the buffer to the new fragment when we split
1229 * the message.
1230 *
1231 * FIXME: It may be fragmented into multiple chunks
1232 * at once if non-fragmentable extension headers
1233 * are too large.
1234 * --yoshfuji
1235 */
1236
1237 inet->cork.length += length;
1238 if (((length > mtu) && (sk->sk_protocol == IPPROTO_UDP)) &&
1239 (rt->u.dst.dev->features & NETIF_F_UFO)) {
1240
1241 err = ip6_ufo_append_data(sk, getfrag, from, length, hh_len,
1242 fragheaderlen, transhdrlen, mtu,
1243 flags);
1244 if (err)
1245 goto error;
1246 return 0;
1247 }
1248
1249 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL)
1250 goto alloc_new_skb;
1251
1252 while (length > 0) {
1253 /* Check if the remaining data fits into current packet. */
1254 copy = (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len;
1255 if (copy < length)
1256 copy = maxfraglen - skb->len;
1257
1258 if (copy <= 0) {
1259 char *data;
1260 unsigned int datalen;
1261 unsigned int fraglen;
1262 unsigned int fraggap;
1263 unsigned int alloclen;
1264 struct sk_buff *skb_prev;
1265 alloc_new_skb:
1266 skb_prev = skb;
1267
1268 /* There's no room in the current skb */
1269 if (skb_prev)
1270 fraggap = skb_prev->len - maxfraglen;
1271 else
1272 fraggap = 0;
1273
1274 /*
1275 * If remaining data exceeds the mtu,
1276 * we know we need more fragment(s).
1277 */
1278 datalen = length + fraggap;
1279 if (datalen > (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen)
1280 datalen = maxfraglen - fragheaderlen;
1281
1282 fraglen = datalen + fragheaderlen;
1283 if ((flags & MSG_MORE) &&
1284 !(rt->u.dst.dev->features&NETIF_F_SG))
1285 alloclen = mtu;
1286 else
1287 alloclen = datalen + fragheaderlen;
1288
1289 /*
1290 * The last fragment gets additional space at tail.
1291 * Note: we overallocate on fragments with MSG_MODE
1292 * because we have no idea if we're the last one.
1293 */
1294 if (datalen == length + fraggap)
1295 alloclen += rt->u.dst.trailer_len;
1296
1297 /*
1298 * We just reserve space for fragment header.
1299 * Note: this may be overallocation if the message
1300 * (without MSG_MORE) fits into the MTU.
1301 */
1302 alloclen += sizeof(struct frag_hdr);
1303
1304 if (transhdrlen) {
1305 skb = sock_alloc_send_skb(sk,
1306 alloclen + hh_len,
1307 (flags & MSG_DONTWAIT), &err);
1308 } else {
1309 skb = NULL;
1310 if (atomic_read(&sk->sk_wmem_alloc) <=
1311 2 * sk->sk_sndbuf)
1312 skb = sock_wmalloc(sk,
1313 alloclen + hh_len, 1,
1314 sk->sk_allocation);
1315 if (unlikely(skb == NULL))
1316 err = -ENOBUFS;
1317 }
1318 if (skb == NULL)
1319 goto error;
1320 /*
1321 * Fill in the control structures
1322 */
1323 skb->ip_summed = csummode;
1324 skb->csum = 0;
1325 /* reserve for fragmentation */
1326 skb_reserve(skb, hh_len+sizeof(struct frag_hdr));
1327
1328 /*
1329 * Find where to start putting bytes
1330 */
1331 data = skb_put(skb, fraglen);
1332 skb_set_network_header(skb, exthdrlen);
1333 data += fragheaderlen;
1334 skb->transport_header = (skb->network_header +
1335 fragheaderlen);
1336 if (fraggap) {
1337 skb->csum = skb_copy_and_csum_bits(
1338 skb_prev, maxfraglen,
1339 data + transhdrlen, fraggap, 0);
1340 skb_prev->csum = csum_sub(skb_prev->csum,
1341 skb->csum);
1342 data += fraggap;
1343 pskb_trim_unique(skb_prev, maxfraglen);
1344 }
1345 copy = datalen - transhdrlen - fraggap;
1346 if (copy < 0) {
1347 err = -EINVAL;
1348 kfree_skb(skb);
1349 goto error;
1350 } else if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) {
1351 err = -EFAULT;
1352 kfree_skb(skb);
1353 goto error;
1354 }
1355
1356 offset += copy;
1357 length -= datalen - fraggap;
1358 transhdrlen = 0;
1359 exthdrlen = 0;
1360 csummode = CHECKSUM_NONE;
1361
1362 /*
1363 * Put the packet on the pending queue
1364 */
1365 __skb_queue_tail(&sk->sk_write_queue, skb);
1366 continue;
1367 }
1368
1369 if (copy > length)
1370 copy = length;
1371
1372 if (!(rt->u.dst.dev->features&NETIF_F_SG)) {
1373 unsigned int off;
1374
1375 off = skb->len;
1376 if (getfrag(from, skb_put(skb, copy),
1377 offset, copy, off, skb) < 0) {
1378 __skb_trim(skb, off);
1379 err = -EFAULT;
1380 goto error;
1381 }
1382 } else {
1383 int i = skb_shinfo(skb)->nr_frags;
1384 skb_frag_t *frag = &skb_shinfo(skb)->frags[i-1];
1385 struct page *page = sk->sk_sndmsg_page;
1386 int off = sk->sk_sndmsg_off;
1387 unsigned int left;
1388
1389 if (page && (left = PAGE_SIZE - off) > 0) {
1390 if (copy >= left)
1391 copy = left;
1392 if (page != frag->page) {
1393 if (i == MAX_SKB_FRAGS) {
1394 err = -EMSGSIZE;
1395 goto error;
1396 }
1397 get_page(page);
1398 skb_fill_page_desc(skb, i, page, sk->sk_sndmsg_off, 0);
1399 frag = &skb_shinfo(skb)->frags[i];
1400 }
1401 } else if(i < MAX_SKB_FRAGS) {
1402 if (copy > PAGE_SIZE)
1403 copy = PAGE_SIZE;
1404 page = alloc_pages(sk->sk_allocation, 0);
1405 if (page == NULL) {
1406 err = -ENOMEM;
1407 goto error;
1408 }
1409 sk->sk_sndmsg_page = page;
1410 sk->sk_sndmsg_off = 0;
1411
1412 skb_fill_page_desc(skb, i, page, 0, 0);
1413 frag = &skb_shinfo(skb)->frags[i];
1414 } else {
1415 err = -EMSGSIZE;
1416 goto error;
1417 }
1418 if (getfrag(from, page_address(frag->page)+frag->page_offset+frag->size, offset, copy, skb->len, skb) < 0) {
1419 err = -EFAULT;
1420 goto error;
1421 }
1422 sk->sk_sndmsg_off += copy;
1423 frag->size += copy;
1424 skb->len += copy;
1425 skb->data_len += copy;
1426 skb->truesize += copy;
1427 atomic_add(copy, &sk->sk_wmem_alloc);
1428 }
1429 offset += copy;
1430 length -= copy;
1431 }
1432 return 0;
1433 error:
1434 inet->cork.length -= length;
1435 IP6_INC_STATS(sock_net(sk), rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS);
1436 return err;
1437 }
1438
1439 static void ip6_cork_release(struct inet_sock *inet, struct ipv6_pinfo *np)
1440 {
1441 if (np->cork.opt) {
1442 kfree(np->cork.opt->dst0opt);
1443 kfree(np->cork.opt->dst1opt);
1444 kfree(np->cork.opt->hopopt);
1445 kfree(np->cork.opt->srcrt);
1446 kfree(np->cork.opt);
1447 np->cork.opt = NULL;
1448 }
1449
1450 if (inet->cork.dst) {
1451 dst_release(inet->cork.dst);
1452 inet->cork.dst = NULL;
1453 inet->cork.flags &= ~IPCORK_ALLFRAG;
1454 }
1455 memset(&inet->cork.fl, 0, sizeof(inet->cork.fl));
1456 }
1457
1458 int ip6_push_pending_frames(struct sock *sk)
1459 {
1460 struct sk_buff *skb, *tmp_skb;
1461 struct sk_buff **tail_skb;
1462 struct in6_addr final_dst_buf, *final_dst = &final_dst_buf;
1463 struct inet_sock *inet = inet_sk(sk);
1464 struct ipv6_pinfo *np = inet6_sk(sk);
1465 struct net *net = sock_net(sk);
1466 struct ipv6hdr *hdr;
1467 struct ipv6_txoptions *opt = np->cork.opt;
1468 struct rt6_info *rt = (struct rt6_info *)inet->cork.dst;
1469 struct flowi *fl = &inet->cork.fl;
1470 unsigned char proto = fl->proto;
1471 int err = 0;
1472
1473 if ((skb = __skb_dequeue(&sk->sk_write_queue)) == NULL)
1474 goto out;
1475 tail_skb = &(skb_shinfo(skb)->frag_list);
1476
1477 /* move skb->data to ip header from ext header */
1478 if (skb->data < skb_network_header(skb))
1479 __skb_pull(skb, skb_network_offset(skb));
1480 while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) {
1481 __skb_pull(tmp_skb, skb_network_header_len(skb));
1482 *tail_skb = tmp_skb;
1483 tail_skb = &(tmp_skb->next);
1484 skb->len += tmp_skb->len;
1485 skb->data_len += tmp_skb->len;
1486 skb->truesize += tmp_skb->truesize;
1487 tmp_skb->destructor = NULL;
1488 tmp_skb->sk = NULL;
1489 }
1490
1491 /* Allow local fragmentation. */
1492 if (np->pmtudisc < IPV6_PMTUDISC_DO)
1493 skb->local_df = 1;
1494
1495 ipv6_addr_copy(final_dst, &fl->fl6_dst);
1496 __skb_pull(skb, skb_network_header_len(skb));
1497 if (opt && opt->opt_flen)
1498 ipv6_push_frag_opts(skb, opt, &proto);
1499 if (opt && opt->opt_nflen)
1500 ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst);
1501
1502 skb_push(skb, sizeof(struct ipv6hdr));
1503 skb_reset_network_header(skb);
1504 hdr = ipv6_hdr(skb);
1505
1506 *(__be32*)hdr = fl->fl6_flowlabel |
1507 htonl(0x60000000 | ((int)np->cork.tclass << 20));
1508
1509 hdr->hop_limit = np->cork.hop_limit;
1510 hdr->nexthdr = proto;
1511 ipv6_addr_copy(&hdr->saddr, &fl->fl6_src);
1512 ipv6_addr_copy(&hdr->daddr, final_dst);
1513
1514 skb->priority = sk->sk_priority;
1515 skb->mark = sk->sk_mark;
1516
1517 skb_dst_set(skb, dst_clone(&rt->u.dst));
1518 IP6_UPD_PO_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUT, skb->len);
1519 if (proto == IPPROTO_ICMPV6) {
1520 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
1521
1522 ICMP6MSGOUT_INC_STATS_BH(net, idev, icmp6_hdr(skb)->icmp6_type);
1523 ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTMSGS);
1524 }
1525
1526 err = ip6_local_out(skb);
1527 if (err) {
1528 if (err > 0)
1529 err = np->recverr ? net_xmit_errno(err) : 0;
1530 if (err)
1531 goto error;
1532 }
1533
1534 out:
1535 ip6_cork_release(inet, np);
1536 return err;
1537 error:
1538 goto out;
1539 }
1540
1541 void ip6_flush_pending_frames(struct sock *sk)
1542 {
1543 struct sk_buff *skb;
1544
1545 while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) {
1546 if (skb_dst(skb))
1547 IP6_INC_STATS(sock_net(sk), ip6_dst_idev(skb_dst(skb)),
1548 IPSTATS_MIB_OUTDISCARDS);
1549 kfree_skb(skb);
1550 }
1551
1552 ip6_cork_release(inet_sk(sk), inet6_sk(sk));
1553 }
Linux kernel - Deliverables
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