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Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
[mirror_ubuntu-zesty-kernel.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 #include <linux/slab.h>
41
42 #include <linux/netfilter.h>
43 #include <linux/netfilter_ipv6.h>
44
45 #include <net/sock.h>
46 #include <net/snmp.h>
47
48 #include <net/ipv6.h>
49 #include <net/ndisc.h>
50 #include <net/protocol.h>
51 #include <net/ip6_route.h>
52 #include <net/addrconf.h>
53 #include <net/rawv6.h>
54 #include <net/icmp.h>
55 #include <net/xfrm.h>
56 #include <net/checksum.h>
57 #include <linux/mroute6.h>
58
59 int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *));
60
61 int __ip6_local_out(struct sk_buff *skb)
62 {
63 int len;
64
65 len = skb->len - sizeof(struct ipv6hdr);
66 if (len > IPV6_MAXPLEN)
67 len = 0;
68 ipv6_hdr(skb)->payload_len = htons(len);
69
70 return nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, skb, NULL,
71 skb_dst(skb)->dev, dst_output);
72 }
73
74 int ip6_local_out(struct sk_buff *skb)
75 {
76 int err;
77
78 err = __ip6_local_out(skb);
79 if (likely(err == 1))
80 err = dst_output(skb);
81
82 return err;
83 }
84 EXPORT_SYMBOL_GPL(ip6_local_out);
85
86 /* dev_loopback_xmit for use with netfilter. */
87 static int ip6_dev_loopback_xmit(struct sk_buff *newskb)
88 {
89 skb_reset_mac_header(newskb);
90 __skb_pull(newskb, skb_network_offset(newskb));
91 newskb->pkt_type = PACKET_LOOPBACK;
92 newskb->ip_summed = CHECKSUM_UNNECESSARY;
93 WARN_ON(!skb_dst(newskb));
94
95 netif_rx_ni(newskb);
96 return 0;
97 }
98
99 static int ip6_finish_output2(struct sk_buff *skb)
100 {
101 struct dst_entry *dst = skb_dst(skb);
102 struct net_device *dev = dst->dev;
103 struct neighbour *neigh;
104
105 skb->protocol = htons(ETH_P_IPV6);
106 skb->dev = dev;
107
108 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) {
109 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
110
111 if (!(dev->flags & IFF_LOOPBACK) && sk_mc_loop(skb->sk) &&
112 ((mroute6_socket(dev_net(dev), skb) &&
113 !(IP6CB(skb)->flags & IP6SKB_FORWARDED)) ||
114 ipv6_chk_mcast_addr(dev, &ipv6_hdr(skb)->daddr,
115 &ipv6_hdr(skb)->saddr))) {
116 struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC);
117
118 /* Do not check for IFF_ALLMULTI; multicast routing
119 is not supported in any case.
120 */
121 if (newskb)
122 NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING,
123 newskb, NULL, newskb->dev,
124 ip6_dev_loopback_xmit);
125
126 if (ipv6_hdr(skb)->hop_limit == 0) {
127 IP6_INC_STATS(dev_net(dev), idev,
128 IPSTATS_MIB_OUTDISCARDS);
129 kfree_skb(skb);
130 return 0;
131 }
132 }
133
134 IP6_UPD_PO_STATS(dev_net(dev), idev, IPSTATS_MIB_OUTMCAST,
135 skb->len);
136 }
137
138 rcu_read_lock();
139 neigh = dst_get_neighbour_noref(dst);
140 if (neigh) {
141 int res = neigh_output(neigh, skb);
142
143 rcu_read_unlock();
144 return res;
145 }
146 rcu_read_unlock();
147 IP6_INC_STATS_BH(dev_net(dst->dev),
148 ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
149 kfree_skb(skb);
150 return -EINVAL;
151 }
152
153 static int ip6_finish_output(struct sk_buff *skb)
154 {
155 if ((skb->len > ip6_skb_dst_mtu(skb) && !skb_is_gso(skb)) ||
156 dst_allfrag(skb_dst(skb)))
157 return ip6_fragment(skb, ip6_finish_output2);
158 else
159 return ip6_finish_output2(skb);
160 }
161
162 int ip6_output(struct sk_buff *skb)
163 {
164 struct net_device *dev = skb_dst(skb)->dev;
165 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
166 if (unlikely(idev->cnf.disable_ipv6)) {
167 IP6_INC_STATS(dev_net(dev), idev,
168 IPSTATS_MIB_OUTDISCARDS);
169 kfree_skb(skb);
170 return 0;
171 }
172
173 return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING, skb, NULL, dev,
174 ip6_finish_output,
175 !(IP6CB(skb)->flags & IP6SKB_REROUTED));
176 }
177
178 /*
179 * xmit an sk_buff (used by TCP, SCTP and DCCP)
180 */
181
182 int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
183 struct ipv6_txoptions *opt, int tclass)
184 {
185 struct net *net = sock_net(sk);
186 struct ipv6_pinfo *np = inet6_sk(sk);
187 struct in6_addr *first_hop = &fl6->daddr;
188 struct dst_entry *dst = skb_dst(skb);
189 struct ipv6hdr *hdr;
190 u8 proto = fl6->flowi6_proto;
191 int seg_len = skb->len;
192 int hlimit = -1;
193 u32 mtu;
194
195 if (opt) {
196 unsigned int head_room;
197
198 /* First: exthdrs may take lots of space (~8K for now)
199 MAX_HEADER is not enough.
200 */
201 head_room = opt->opt_nflen + opt->opt_flen;
202 seg_len += head_room;
203 head_room += sizeof(struct ipv6hdr) + LL_RESERVED_SPACE(dst->dev);
204
205 if (skb_headroom(skb) < head_room) {
206 struct sk_buff *skb2 = skb_realloc_headroom(skb, head_room);
207 if (skb2 == NULL) {
208 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
209 IPSTATS_MIB_OUTDISCARDS);
210 kfree_skb(skb);
211 return -ENOBUFS;
212 }
213 consume_skb(skb);
214 skb = skb2;
215 skb_set_owner_w(skb, sk);
216 }
217 if (opt->opt_flen)
218 ipv6_push_frag_opts(skb, opt, &proto);
219 if (opt->opt_nflen)
220 ipv6_push_nfrag_opts(skb, opt, &proto, &first_hop);
221 }
222
223 skb_push(skb, sizeof(struct ipv6hdr));
224 skb_reset_network_header(skb);
225 hdr = ipv6_hdr(skb);
226
227 /*
228 * Fill in the IPv6 header
229 */
230 if (np)
231 hlimit = np->hop_limit;
232 if (hlimit < 0)
233 hlimit = ip6_dst_hoplimit(dst);
234
235 *(__be32 *)hdr = htonl(0x60000000 | (tclass << 20)) | fl6->flowlabel;
236
237 hdr->payload_len = htons(seg_len);
238 hdr->nexthdr = proto;
239 hdr->hop_limit = hlimit;
240
241 hdr->saddr = fl6->saddr;
242 hdr->daddr = *first_hop;
243
244 skb->priority = sk->sk_priority;
245 skb->mark = sk->sk_mark;
246
247 mtu = dst_mtu(dst);
248 if ((skb->len <= mtu) || skb->local_df || skb_is_gso(skb)) {
249 IP6_UPD_PO_STATS(net, ip6_dst_idev(skb_dst(skb)),
250 IPSTATS_MIB_OUT, skb->len);
251 return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, skb, NULL,
252 dst->dev, dst_output);
253 }
254
255 net_dbg_ratelimited("IPv6: sending pkt_too_big to self\n");
256 skb->dev = dst->dev;
257 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
258 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_FRAGFAILS);
259 kfree_skb(skb);
260 return -EMSGSIZE;
261 }
262
263 EXPORT_SYMBOL(ip6_xmit);
264
265 /*
266 * To avoid extra problems ND packets are send through this
267 * routine. It's code duplication but I really want to avoid
268 * extra checks since ipv6_build_header is used by TCP (which
269 * is for us performance critical)
270 */
271
272 int ip6_nd_hdr(struct sock *sk, struct sk_buff *skb, struct net_device *dev,
273 const struct in6_addr *saddr, const struct in6_addr *daddr,
274 int proto, int len)
275 {
276 struct ipv6_pinfo *np = inet6_sk(sk);
277 struct ipv6hdr *hdr;
278
279 skb->protocol = htons(ETH_P_IPV6);
280 skb->dev = dev;
281
282 skb_reset_network_header(skb);
283 skb_put(skb, sizeof(struct ipv6hdr));
284 hdr = ipv6_hdr(skb);
285
286 *(__be32*)hdr = htonl(0x60000000);
287
288 hdr->payload_len = htons(len);
289 hdr->nexthdr = proto;
290 hdr->hop_limit = np->hop_limit;
291
292 hdr->saddr = *saddr;
293 hdr->daddr = *daddr;
294
295 return 0;
296 }
297
298 static int ip6_call_ra_chain(struct sk_buff *skb, int sel)
299 {
300 struct ip6_ra_chain *ra;
301 struct sock *last = NULL;
302
303 read_lock(&ip6_ra_lock);
304 for (ra = ip6_ra_chain; ra; ra = ra->next) {
305 struct sock *sk = ra->sk;
306 if (sk && ra->sel == sel &&
307 (!sk->sk_bound_dev_if ||
308 sk->sk_bound_dev_if == skb->dev->ifindex)) {
309 if (last) {
310 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
311 if (skb2)
312 rawv6_rcv(last, skb2);
313 }
314 last = sk;
315 }
316 }
317
318 if (last) {
319 rawv6_rcv(last, skb);
320 read_unlock(&ip6_ra_lock);
321 return 1;
322 }
323 read_unlock(&ip6_ra_lock);
324 return 0;
325 }
326
327 static int ip6_forward_proxy_check(struct sk_buff *skb)
328 {
329 struct ipv6hdr *hdr = ipv6_hdr(skb);
330 u8 nexthdr = hdr->nexthdr;
331 __be16 frag_off;
332 int offset;
333
334 if (ipv6_ext_hdr(nexthdr)) {
335 offset = ipv6_skip_exthdr(skb, sizeof(*hdr), &nexthdr, &frag_off);
336 if (offset < 0)
337 return 0;
338 } else
339 offset = sizeof(struct ipv6hdr);
340
341 if (nexthdr == IPPROTO_ICMPV6) {
342 struct icmp6hdr *icmp6;
343
344 if (!pskb_may_pull(skb, (skb_network_header(skb) +
345 offset + 1 - skb->data)))
346 return 0;
347
348 icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset);
349
350 switch (icmp6->icmp6_type) {
351 case NDISC_ROUTER_SOLICITATION:
352 case NDISC_ROUTER_ADVERTISEMENT:
353 case NDISC_NEIGHBOUR_SOLICITATION:
354 case NDISC_NEIGHBOUR_ADVERTISEMENT:
355 case NDISC_REDIRECT:
356 /* For reaction involving unicast neighbor discovery
357 * message destined to the proxied address, pass it to
358 * input function.
359 */
360 return 1;
361 default:
362 break;
363 }
364 }
365
366 /*
367 * The proxying router can't forward traffic sent to a link-local
368 * address, so signal the sender and discard the packet. This
369 * behavior is clarified by the MIPv6 specification.
370 */
371 if (ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) {
372 dst_link_failure(skb);
373 return -1;
374 }
375
376 return 0;
377 }
378
379 static inline int ip6_forward_finish(struct sk_buff *skb)
380 {
381 return dst_output(skb);
382 }
383
384 int ip6_forward(struct sk_buff *skb)
385 {
386 struct dst_entry *dst = skb_dst(skb);
387 struct ipv6hdr *hdr = ipv6_hdr(skb);
388 struct inet6_skb_parm *opt = IP6CB(skb);
389 struct net *net = dev_net(dst->dev);
390 u32 mtu;
391
392 if (net->ipv6.devconf_all->forwarding == 0)
393 goto error;
394
395 if (skb_warn_if_lro(skb))
396 goto drop;
397
398 if (!xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) {
399 IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS);
400 goto drop;
401 }
402
403 if (skb->pkt_type != PACKET_HOST)
404 goto drop;
405
406 skb_forward_csum(skb);
407
408 /*
409 * We DO NOT make any processing on
410 * RA packets, pushing them to user level AS IS
411 * without ane WARRANTY that application will be able
412 * to interpret them. The reason is that we
413 * cannot make anything clever here.
414 *
415 * We are not end-node, so that if packet contains
416 * AH/ESP, we cannot make anything.
417 * Defragmentation also would be mistake, RA packets
418 * cannot be fragmented, because there is no warranty
419 * that different fragments will go along one path. --ANK
420 */
421 if (opt->ra) {
422 u8 *ptr = skb_network_header(skb) + opt->ra;
423 if (ip6_call_ra_chain(skb, (ptr[2]<<8) + ptr[3]))
424 return 0;
425 }
426
427 /*
428 * check and decrement ttl
429 */
430 if (hdr->hop_limit <= 1) {
431 /* Force OUTPUT device used as source address */
432 skb->dev = dst->dev;
433 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 0);
434 IP6_INC_STATS_BH(net,
435 ip6_dst_idev(dst), IPSTATS_MIB_INHDRERRORS);
436
437 kfree_skb(skb);
438 return -ETIMEDOUT;
439 }
440
441 /* XXX: idev->cnf.proxy_ndp? */
442 if (net->ipv6.devconf_all->proxy_ndp &&
443 pneigh_lookup(&nd_tbl, net, &hdr->daddr, skb->dev, 0)) {
444 int proxied = ip6_forward_proxy_check(skb);
445 if (proxied > 0)
446 return ip6_input(skb);
447 else if (proxied < 0) {
448 IP6_INC_STATS(net, ip6_dst_idev(dst),
449 IPSTATS_MIB_INDISCARDS);
450 goto drop;
451 }
452 }
453
454 if (!xfrm6_route_forward(skb)) {
455 IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS);
456 goto drop;
457 }
458 dst = skb_dst(skb);
459
460 /* IPv6 specs say nothing about it, but it is clear that we cannot
461 send redirects to source routed frames.
462 We don't send redirects to frames decapsulated from IPsec.
463 */
464 if (skb->dev == dst->dev && opt->srcrt == 0 && !skb_sec_path(skb)) {
465 struct in6_addr *target = NULL;
466 struct rt6_info *rt;
467
468 /*
469 * incoming and outgoing devices are the same
470 * send a redirect.
471 */
472
473 rt = (struct rt6_info *) dst;
474 if (rt->rt6i_flags & RTF_GATEWAY)
475 target = &rt->rt6i_gateway;
476 else
477 target = &hdr->daddr;
478
479 if (!rt->rt6i_peer)
480 rt6_bind_peer(rt, 1);
481
482 /* Limit redirects both by destination (here)
483 and by source (inside ndisc_send_redirect)
484 */
485 if (inet_peer_xrlim_allow(rt->rt6i_peer, 1*HZ))
486 ndisc_send_redirect(skb, target);
487 } else {
488 int addrtype = ipv6_addr_type(&hdr->saddr);
489
490 /* This check is security critical. */
491 if (addrtype == IPV6_ADDR_ANY ||
492 addrtype & (IPV6_ADDR_MULTICAST | IPV6_ADDR_LOOPBACK))
493 goto error;
494 if (addrtype & IPV6_ADDR_LINKLOCAL) {
495 icmpv6_send(skb, ICMPV6_DEST_UNREACH,
496 ICMPV6_NOT_NEIGHBOUR, 0);
497 goto error;
498 }
499 }
500
501 mtu = dst_mtu(dst);
502 if (mtu < IPV6_MIN_MTU)
503 mtu = IPV6_MIN_MTU;
504
505 if (skb->len > mtu && !skb_is_gso(skb)) {
506 /* Again, force OUTPUT device used as source address */
507 skb->dev = dst->dev;
508 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
509 IP6_INC_STATS_BH(net,
510 ip6_dst_idev(dst), IPSTATS_MIB_INTOOBIGERRORS);
511 IP6_INC_STATS_BH(net,
512 ip6_dst_idev(dst), IPSTATS_MIB_FRAGFAILS);
513 kfree_skb(skb);
514 return -EMSGSIZE;
515 }
516
517 if (skb_cow(skb, dst->dev->hard_header_len)) {
518 IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTDISCARDS);
519 goto drop;
520 }
521
522 hdr = ipv6_hdr(skb);
523
524 /* Mangling hops number delayed to point after skb COW */
525
526 hdr->hop_limit--;
527
528 IP6_INC_STATS_BH(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTFORWDATAGRAMS);
529 IP6_ADD_STATS_BH(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTOCTETS, skb->len);
530 return NF_HOOK(NFPROTO_IPV6, NF_INET_FORWARD, skb, skb->dev, dst->dev,
531 ip6_forward_finish);
532
533 error:
534 IP6_INC_STATS_BH(net, ip6_dst_idev(dst), IPSTATS_MIB_INADDRERRORS);
535 drop:
536 kfree_skb(skb);
537 return -EINVAL;
538 }
539
540 static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from)
541 {
542 to->pkt_type = from->pkt_type;
543 to->priority = from->priority;
544 to->protocol = from->protocol;
545 skb_dst_drop(to);
546 skb_dst_set(to, dst_clone(skb_dst(from)));
547 to->dev = from->dev;
548 to->mark = from->mark;
549
550 #ifdef CONFIG_NET_SCHED
551 to->tc_index = from->tc_index;
552 #endif
553 nf_copy(to, from);
554 #if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \
555 defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE)
556 to->nf_trace = from->nf_trace;
557 #endif
558 skb_copy_secmark(to, from);
559 }
560
561 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr)
562 {
563 u16 offset = sizeof(struct ipv6hdr);
564 struct ipv6_opt_hdr *exthdr =
565 (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
566 unsigned int packet_len = skb->tail - skb->network_header;
567 int found_rhdr = 0;
568 *nexthdr = &ipv6_hdr(skb)->nexthdr;
569
570 while (offset + 1 <= packet_len) {
571
572 switch (**nexthdr) {
573
574 case NEXTHDR_HOP:
575 break;
576 case NEXTHDR_ROUTING:
577 found_rhdr = 1;
578 break;
579 case NEXTHDR_DEST:
580 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
581 if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
582 break;
583 #endif
584 if (found_rhdr)
585 return offset;
586 break;
587 default :
588 return offset;
589 }
590
591 offset += ipv6_optlen(exthdr);
592 *nexthdr = &exthdr->nexthdr;
593 exthdr = (struct ipv6_opt_hdr *)(skb_network_header(skb) +
594 offset);
595 }
596
597 return offset;
598 }
599
600 void ipv6_select_ident(struct frag_hdr *fhdr, struct rt6_info *rt)
601 {
602 static atomic_t ipv6_fragmentation_id;
603 int old, new;
604
605 if (rt && !(rt->dst.flags & DST_NOPEER)) {
606 struct inet_peer *peer;
607
608 if (!rt->rt6i_peer)
609 rt6_bind_peer(rt, 1);
610 peer = rt->rt6i_peer;
611 if (peer) {
612 fhdr->identification = htonl(inet_getid(peer, 0));
613 return;
614 }
615 }
616 do {
617 old = atomic_read(&ipv6_fragmentation_id);
618 new = old + 1;
619 if (!new)
620 new = 1;
621 } while (atomic_cmpxchg(&ipv6_fragmentation_id, old, new) != old);
622 fhdr->identification = htonl(new);
623 }
624
625 int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *))
626 {
627 struct sk_buff *frag;
628 struct rt6_info *rt = (struct rt6_info*)skb_dst(skb);
629 struct ipv6_pinfo *np = skb->sk ? inet6_sk(skb->sk) : NULL;
630 struct ipv6hdr *tmp_hdr;
631 struct frag_hdr *fh;
632 unsigned int mtu, hlen, left, len;
633 int hroom, troom;
634 __be32 frag_id = 0;
635 int ptr, offset = 0, err=0;
636 u8 *prevhdr, nexthdr = 0;
637 struct net *net = dev_net(skb_dst(skb)->dev);
638
639 hlen = ip6_find_1stfragopt(skb, &prevhdr);
640 nexthdr = *prevhdr;
641
642 mtu = ip6_skb_dst_mtu(skb);
643
644 /* We must not fragment if the socket is set to force MTU discovery
645 * or if the skb it not generated by a local socket.
646 */
647 if (unlikely(!skb->local_df && skb->len > mtu)) {
648 if (skb->sk && dst_allfrag(skb_dst(skb)))
649 sk_nocaps_add(skb->sk, NETIF_F_GSO_MASK);
650
651 skb->dev = skb_dst(skb)->dev;
652 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
653 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
654 IPSTATS_MIB_FRAGFAILS);
655 kfree_skb(skb);
656 return -EMSGSIZE;
657 }
658
659 if (np && np->frag_size < mtu) {
660 if (np->frag_size)
661 mtu = np->frag_size;
662 }
663 mtu -= hlen + sizeof(struct frag_hdr);
664
665 if (skb_has_frag_list(skb)) {
666 int first_len = skb_pagelen(skb);
667 struct sk_buff *frag2;
668
669 if (first_len - hlen > mtu ||
670 ((first_len - hlen) & 7) ||
671 skb_cloned(skb))
672 goto slow_path;
673
674 skb_walk_frags(skb, frag) {
675 /* Correct geometry. */
676 if (frag->len > mtu ||
677 ((frag->len & 7) && frag->next) ||
678 skb_headroom(frag) < hlen)
679 goto slow_path_clean;
680
681 /* Partially cloned skb? */
682 if (skb_shared(frag))
683 goto slow_path_clean;
684
685 BUG_ON(frag->sk);
686 if (skb->sk) {
687 frag->sk = skb->sk;
688 frag->destructor = sock_wfree;
689 }
690 skb->truesize -= frag->truesize;
691 }
692
693 err = 0;
694 offset = 0;
695 frag = skb_shinfo(skb)->frag_list;
696 skb_frag_list_init(skb);
697 /* BUILD HEADER */
698
699 *prevhdr = NEXTHDR_FRAGMENT;
700 tmp_hdr = kmemdup(skb_network_header(skb), hlen, GFP_ATOMIC);
701 if (!tmp_hdr) {
702 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
703 IPSTATS_MIB_FRAGFAILS);
704 return -ENOMEM;
705 }
706
707 __skb_pull(skb, hlen);
708 fh = (struct frag_hdr*)__skb_push(skb, sizeof(struct frag_hdr));
709 __skb_push(skb, hlen);
710 skb_reset_network_header(skb);
711 memcpy(skb_network_header(skb), tmp_hdr, hlen);
712
713 ipv6_select_ident(fh, rt);
714 fh->nexthdr = nexthdr;
715 fh->reserved = 0;
716 fh->frag_off = htons(IP6_MF);
717 frag_id = fh->identification;
718
719 first_len = skb_pagelen(skb);
720 skb->data_len = first_len - skb_headlen(skb);
721 skb->len = first_len;
722 ipv6_hdr(skb)->payload_len = htons(first_len -
723 sizeof(struct ipv6hdr));
724
725 dst_hold(&rt->dst);
726
727 for (;;) {
728 /* Prepare header of the next frame,
729 * before previous one went down. */
730 if (frag) {
731 frag->ip_summed = CHECKSUM_NONE;
732 skb_reset_transport_header(frag);
733 fh = (struct frag_hdr*)__skb_push(frag, sizeof(struct frag_hdr));
734 __skb_push(frag, hlen);
735 skb_reset_network_header(frag);
736 memcpy(skb_network_header(frag), tmp_hdr,
737 hlen);
738 offset += skb->len - hlen - sizeof(struct frag_hdr);
739 fh->nexthdr = nexthdr;
740 fh->reserved = 0;
741 fh->frag_off = htons(offset);
742 if (frag->next != NULL)
743 fh->frag_off |= htons(IP6_MF);
744 fh->identification = frag_id;
745 ipv6_hdr(frag)->payload_len =
746 htons(frag->len -
747 sizeof(struct ipv6hdr));
748 ip6_copy_metadata(frag, skb);
749 }
750
751 err = output(skb);
752 if(!err)
753 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
754 IPSTATS_MIB_FRAGCREATES);
755
756 if (err || !frag)
757 break;
758
759 skb = frag;
760 frag = skb->next;
761 skb->next = NULL;
762 }
763
764 kfree(tmp_hdr);
765
766 if (err == 0) {
767 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
768 IPSTATS_MIB_FRAGOKS);
769 dst_release(&rt->dst);
770 return 0;
771 }
772
773 while (frag) {
774 skb = frag->next;
775 kfree_skb(frag);
776 frag = skb;
777 }
778
779 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
780 IPSTATS_MIB_FRAGFAILS);
781 dst_release(&rt->dst);
782 return err;
783
784 slow_path_clean:
785 skb_walk_frags(skb, frag2) {
786 if (frag2 == frag)
787 break;
788 frag2->sk = NULL;
789 frag2->destructor = NULL;
790 skb->truesize += frag2->truesize;
791 }
792 }
793
794 slow_path:
795 if ((skb->ip_summed == CHECKSUM_PARTIAL) &&
796 skb_checksum_help(skb))
797 goto fail;
798
799 left = skb->len - hlen; /* Space per frame */
800 ptr = hlen; /* Where to start from */
801
802 /*
803 * Fragment the datagram.
804 */
805
806 *prevhdr = NEXTHDR_FRAGMENT;
807 hroom = LL_RESERVED_SPACE(rt->dst.dev);
808 troom = rt->dst.dev->needed_tailroom;
809
810 /*
811 * Keep copying data until we run out.
812 */
813 while(left > 0) {
814 len = left;
815 /* IF: it doesn't fit, use 'mtu' - the data space left */
816 if (len > mtu)
817 len = mtu;
818 /* IF: we are not sending up to and including the packet end
819 then align the next start on an eight byte boundary */
820 if (len < left) {
821 len &= ~7;
822 }
823 /*
824 * Allocate buffer.
825 */
826
827 if ((frag = alloc_skb(len + hlen + sizeof(struct frag_hdr) +
828 hroom + troom, GFP_ATOMIC)) == NULL) {
829 NETDEBUG(KERN_INFO "IPv6: frag: no memory for new fragment!\n");
830 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
831 IPSTATS_MIB_FRAGFAILS);
832 err = -ENOMEM;
833 goto fail;
834 }
835
836 /*
837 * Set up data on packet
838 */
839
840 ip6_copy_metadata(frag, skb);
841 skb_reserve(frag, hroom);
842 skb_put(frag, len + hlen + sizeof(struct frag_hdr));
843 skb_reset_network_header(frag);
844 fh = (struct frag_hdr *)(skb_network_header(frag) + hlen);
845 frag->transport_header = (frag->network_header + hlen +
846 sizeof(struct frag_hdr));
847
848 /*
849 * Charge the memory for the fragment to any owner
850 * it might possess
851 */
852 if (skb->sk)
853 skb_set_owner_w(frag, skb->sk);
854
855 /*
856 * Copy the packet header into the new buffer.
857 */
858 skb_copy_from_linear_data(skb, skb_network_header(frag), hlen);
859
860 /*
861 * Build fragment header.
862 */
863 fh->nexthdr = nexthdr;
864 fh->reserved = 0;
865 if (!frag_id) {
866 ipv6_select_ident(fh, rt);
867 frag_id = fh->identification;
868 } else
869 fh->identification = frag_id;
870
871 /*
872 * Copy a block of the IP datagram.
873 */
874 if (skb_copy_bits(skb, ptr, skb_transport_header(frag), len))
875 BUG();
876 left -= len;
877
878 fh->frag_off = htons(offset);
879 if (left > 0)
880 fh->frag_off |= htons(IP6_MF);
881 ipv6_hdr(frag)->payload_len = htons(frag->len -
882 sizeof(struct ipv6hdr));
883
884 ptr += len;
885 offset += len;
886
887 /*
888 * Put this fragment into the sending queue.
889 */
890 err = output(frag);
891 if (err)
892 goto fail;
893
894 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
895 IPSTATS_MIB_FRAGCREATES);
896 }
897 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
898 IPSTATS_MIB_FRAGOKS);
899 consume_skb(skb);
900 return err;
901
902 fail:
903 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
904 IPSTATS_MIB_FRAGFAILS);
905 kfree_skb(skb);
906 return err;
907 }
908
909 static inline int ip6_rt_check(const struct rt6key *rt_key,
910 const struct in6_addr *fl_addr,
911 const struct in6_addr *addr_cache)
912 {
913 return (rt_key->plen != 128 || !ipv6_addr_equal(fl_addr, &rt_key->addr)) &&
914 (addr_cache == NULL || !ipv6_addr_equal(fl_addr, addr_cache));
915 }
916
917 static struct dst_entry *ip6_sk_dst_check(struct sock *sk,
918 struct dst_entry *dst,
919 const struct flowi6 *fl6)
920 {
921 struct ipv6_pinfo *np = inet6_sk(sk);
922 struct rt6_info *rt = (struct rt6_info *)dst;
923
924 if (!dst)
925 goto out;
926
927 /* Yes, checking route validity in not connected
928 * case is not very simple. Take into account,
929 * that we do not support routing by source, TOS,
930 * and MSG_DONTROUTE --ANK (980726)
931 *
932 * 1. ip6_rt_check(): If route was host route,
933 * check that cached destination is current.
934 * If it is network route, we still may
935 * check its validity using saved pointer
936 * to the last used address: daddr_cache.
937 * We do not want to save whole address now,
938 * (because main consumer of this service
939 * is tcp, which has not this problem),
940 * so that the last trick works only on connected
941 * sockets.
942 * 2. oif also should be the same.
943 */
944 if (ip6_rt_check(&rt->rt6i_dst, &fl6->daddr, np->daddr_cache) ||
945 #ifdef CONFIG_IPV6_SUBTREES
946 ip6_rt_check(&rt->rt6i_src, &fl6->saddr, np->saddr_cache) ||
947 #endif
948 (fl6->flowi6_oif && fl6->flowi6_oif != dst->dev->ifindex)) {
949 dst_release(dst);
950 dst = NULL;
951 }
952
953 out:
954 return dst;
955 }
956
957 static int ip6_dst_lookup_tail(struct sock *sk,
958 struct dst_entry **dst, struct flowi6 *fl6)
959 {
960 struct net *net = sock_net(sk);
961 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
962 struct neighbour *n;
963 #endif
964 int err;
965
966 if (*dst == NULL)
967 *dst = ip6_route_output(net, sk, fl6);
968
969 if ((err = (*dst)->error))
970 goto out_err_release;
971
972 if (ipv6_addr_any(&fl6->saddr)) {
973 struct rt6_info *rt = (struct rt6_info *) *dst;
974 err = ip6_route_get_saddr(net, rt, &fl6->daddr,
975 sk ? inet6_sk(sk)->srcprefs : 0,
976 &fl6->saddr);
977 if (err)
978 goto out_err_release;
979 }
980
981 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
982 /*
983 * Here if the dst entry we've looked up
984 * has a neighbour entry that is in the INCOMPLETE
985 * state and the src address from the flow is
986 * marked as OPTIMISTIC, we release the found
987 * dst entry and replace it instead with the
988 * dst entry of the nexthop router
989 */
990 rcu_read_lock();
991 n = dst_get_neighbour_noref(*dst);
992 if (n && !(n->nud_state & NUD_VALID)) {
993 struct inet6_ifaddr *ifp;
994 struct flowi6 fl_gw6;
995 int redirect;
996
997 rcu_read_unlock();
998 ifp = ipv6_get_ifaddr(net, &fl6->saddr,
999 (*dst)->dev, 1);
1000
1001 redirect = (ifp && ifp->flags & IFA_F_OPTIMISTIC);
1002 if (ifp)
1003 in6_ifa_put(ifp);
1004
1005 if (redirect) {
1006 /*
1007 * We need to get the dst entry for the
1008 * default router instead
1009 */
1010 dst_release(*dst);
1011 memcpy(&fl_gw6, fl6, sizeof(struct flowi6));
1012 memset(&fl_gw6.daddr, 0, sizeof(struct in6_addr));
1013 *dst = ip6_route_output(net, sk, &fl_gw6);
1014 if ((err = (*dst)->error))
1015 goto out_err_release;
1016 }
1017 } else {
1018 rcu_read_unlock();
1019 }
1020 #endif
1021
1022 return 0;
1023
1024 out_err_release:
1025 if (err == -ENETUNREACH)
1026 IP6_INC_STATS_BH(net, NULL, IPSTATS_MIB_OUTNOROUTES);
1027 dst_release(*dst);
1028 *dst = NULL;
1029 return err;
1030 }
1031
1032 /**
1033 * ip6_dst_lookup - perform route lookup on flow
1034 * @sk: socket which provides route info
1035 * @dst: pointer to dst_entry * for result
1036 * @fl6: flow to lookup
1037 *
1038 * This function performs a route lookup on the given flow.
1039 *
1040 * It returns zero on success, or a standard errno code on error.
1041 */
1042 int ip6_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi6 *fl6)
1043 {
1044 *dst = NULL;
1045 return ip6_dst_lookup_tail(sk, dst, fl6);
1046 }
1047 EXPORT_SYMBOL_GPL(ip6_dst_lookup);
1048
1049 /**
1050 * ip6_dst_lookup_flow - perform route lookup on flow with ipsec
1051 * @sk: socket which provides route info
1052 * @fl6: flow to lookup
1053 * @final_dst: final destination address for ipsec lookup
1054 * @can_sleep: we are in a sleepable context
1055 *
1056 * This function performs a route lookup on the given flow.
1057 *
1058 * It returns a valid dst pointer on success, or a pointer encoded
1059 * error code.
1060 */
1061 struct dst_entry *ip6_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
1062 const struct in6_addr *final_dst,
1063 bool can_sleep)
1064 {
1065 struct dst_entry *dst = NULL;
1066 int err;
1067
1068 err = ip6_dst_lookup_tail(sk, &dst, fl6);
1069 if (err)
1070 return ERR_PTR(err);
1071 if (final_dst)
1072 fl6->daddr = *final_dst;
1073 if (can_sleep)
1074 fl6->flowi6_flags |= FLOWI_FLAG_CAN_SLEEP;
1075
1076 return xfrm_lookup(sock_net(sk), dst, flowi6_to_flowi(fl6), sk, 0);
1077 }
1078 EXPORT_SYMBOL_GPL(ip6_dst_lookup_flow);
1079
1080 /**
1081 * ip6_sk_dst_lookup_flow - perform socket cached route lookup on flow
1082 * @sk: socket which provides the dst cache and route info
1083 * @fl6: flow to lookup
1084 * @final_dst: final destination address for ipsec lookup
1085 * @can_sleep: we are in a sleepable context
1086 *
1087 * This function performs a route lookup on the given flow with the
1088 * possibility of using the cached route in the socket if it is valid.
1089 * It will take the socket dst lock when operating on the dst cache.
1090 * As a result, this function can only be used in process context.
1091 *
1092 * It returns a valid dst pointer on success, or a pointer encoded
1093 * error code.
1094 */
1095 struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
1096 const struct in6_addr *final_dst,
1097 bool can_sleep)
1098 {
1099 struct dst_entry *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie);
1100 int err;
1101
1102 dst = ip6_sk_dst_check(sk, dst, fl6);
1103
1104 err = ip6_dst_lookup_tail(sk, &dst, fl6);
1105 if (err)
1106 return ERR_PTR(err);
1107 if (final_dst)
1108 fl6->daddr = *final_dst;
1109 if (can_sleep)
1110 fl6->flowi6_flags |= FLOWI_FLAG_CAN_SLEEP;
1111
1112 return xfrm_lookup(sock_net(sk), dst, flowi6_to_flowi(fl6), sk, 0);
1113 }
1114 EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup_flow);
1115
1116 static inline int ip6_ufo_append_data(struct sock *sk,
1117 int getfrag(void *from, char *to, int offset, int len,
1118 int odd, struct sk_buff *skb),
1119 void *from, int length, int hh_len, int fragheaderlen,
1120 int transhdrlen, int mtu,unsigned int flags,
1121 struct rt6_info *rt)
1122
1123 {
1124 struct sk_buff *skb;
1125 int err;
1126
1127 /* There is support for UDP large send offload by network
1128 * device, so create one single skb packet containing complete
1129 * udp datagram
1130 */
1131 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) {
1132 skb = sock_alloc_send_skb(sk,
1133 hh_len + fragheaderlen + transhdrlen + 20,
1134 (flags & MSG_DONTWAIT), &err);
1135 if (skb == NULL)
1136 return err;
1137
1138 /* reserve space for Hardware header */
1139 skb_reserve(skb, hh_len);
1140
1141 /* create space for UDP/IP header */
1142 skb_put(skb,fragheaderlen + transhdrlen);
1143
1144 /* initialize network header pointer */
1145 skb_reset_network_header(skb);
1146
1147 /* initialize protocol header pointer */
1148 skb->transport_header = skb->network_header + fragheaderlen;
1149
1150 skb->ip_summed = CHECKSUM_PARTIAL;
1151 skb->csum = 0;
1152 }
1153
1154 err = skb_append_datato_frags(sk,skb, getfrag, from,
1155 (length - transhdrlen));
1156 if (!err) {
1157 struct frag_hdr fhdr;
1158
1159 /* Specify the length of each IPv6 datagram fragment.
1160 * It has to be a multiple of 8.
1161 */
1162 skb_shinfo(skb)->gso_size = (mtu - fragheaderlen -
1163 sizeof(struct frag_hdr)) & ~7;
1164 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
1165 ipv6_select_ident(&fhdr, rt);
1166 skb_shinfo(skb)->ip6_frag_id = fhdr.identification;
1167 __skb_queue_tail(&sk->sk_write_queue, skb);
1168
1169 return 0;
1170 }
1171 /* There is not enough support do UPD LSO,
1172 * so follow normal path
1173 */
1174 kfree_skb(skb);
1175
1176 return err;
1177 }
1178
1179 static inline struct ipv6_opt_hdr *ip6_opt_dup(struct ipv6_opt_hdr *src,
1180 gfp_t gfp)
1181 {
1182 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL;
1183 }
1184
1185 static inline struct ipv6_rt_hdr *ip6_rthdr_dup(struct ipv6_rt_hdr *src,
1186 gfp_t gfp)
1187 {
1188 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL;
1189 }
1190
1191 static void ip6_append_data_mtu(int *mtu,
1192 int *maxfraglen,
1193 unsigned int fragheaderlen,
1194 struct sk_buff *skb,
1195 struct rt6_info *rt)
1196 {
1197 if (!(rt->dst.flags & DST_XFRM_TUNNEL)) {
1198 if (skb == NULL) {
1199 /* first fragment, reserve header_len */
1200 *mtu = *mtu - rt->dst.header_len;
1201
1202 } else {
1203 /*
1204 * this fragment is not first, the headers
1205 * space is regarded as data space.
1206 */
1207 *mtu = dst_mtu(rt->dst.path);
1208 }
1209 *maxfraglen = ((*mtu - fragheaderlen) & ~7)
1210 + fragheaderlen - sizeof(struct frag_hdr);
1211 }
1212 }
1213
1214 int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
1215 int offset, int len, int odd, struct sk_buff *skb),
1216 void *from, int length, int transhdrlen,
1217 int hlimit, int tclass, struct ipv6_txoptions *opt, struct flowi6 *fl6,
1218 struct rt6_info *rt, unsigned int flags, int dontfrag)
1219 {
1220 struct inet_sock *inet = inet_sk(sk);
1221 struct ipv6_pinfo *np = inet6_sk(sk);
1222 struct inet_cork *cork;
1223 struct sk_buff *skb, *skb_prev = NULL;
1224 unsigned int maxfraglen, fragheaderlen;
1225 int exthdrlen;
1226 int dst_exthdrlen;
1227 int hh_len;
1228 int mtu;
1229 int copy;
1230 int err;
1231 int offset = 0;
1232 __u8 tx_flags = 0;
1233
1234 if (flags&MSG_PROBE)
1235 return 0;
1236 cork = &inet->cork.base;
1237 if (skb_queue_empty(&sk->sk_write_queue)) {
1238 /*
1239 * setup for corking
1240 */
1241 if (opt) {
1242 if (WARN_ON(np->cork.opt))
1243 return -EINVAL;
1244
1245 np->cork.opt = kmalloc(opt->tot_len, sk->sk_allocation);
1246 if (unlikely(np->cork.opt == NULL))
1247 return -ENOBUFS;
1248
1249 np->cork.opt->tot_len = opt->tot_len;
1250 np->cork.opt->opt_flen = opt->opt_flen;
1251 np->cork.opt->opt_nflen = opt->opt_nflen;
1252
1253 np->cork.opt->dst0opt = ip6_opt_dup(opt->dst0opt,
1254 sk->sk_allocation);
1255 if (opt->dst0opt && !np->cork.opt->dst0opt)
1256 return -ENOBUFS;
1257
1258 np->cork.opt->dst1opt = ip6_opt_dup(opt->dst1opt,
1259 sk->sk_allocation);
1260 if (opt->dst1opt && !np->cork.opt->dst1opt)
1261 return -ENOBUFS;
1262
1263 np->cork.opt->hopopt = ip6_opt_dup(opt->hopopt,
1264 sk->sk_allocation);
1265 if (opt->hopopt && !np->cork.opt->hopopt)
1266 return -ENOBUFS;
1267
1268 np->cork.opt->srcrt = ip6_rthdr_dup(opt->srcrt,
1269 sk->sk_allocation);
1270 if (opt->srcrt && !np->cork.opt->srcrt)
1271 return -ENOBUFS;
1272
1273 /* need source address above miyazawa*/
1274 }
1275 dst_hold(&rt->dst);
1276 cork->dst = &rt->dst;
1277 inet->cork.fl.u.ip6 = *fl6;
1278 np->cork.hop_limit = hlimit;
1279 np->cork.tclass = tclass;
1280 if (rt->dst.flags & DST_XFRM_TUNNEL)
1281 mtu = np->pmtudisc == IPV6_PMTUDISC_PROBE ?
1282 rt->dst.dev->mtu : dst_mtu(&rt->dst);
1283 else
1284 mtu = np->pmtudisc == IPV6_PMTUDISC_PROBE ?
1285 rt->dst.dev->mtu : dst_mtu(rt->dst.path);
1286 if (np->frag_size < mtu) {
1287 if (np->frag_size)
1288 mtu = np->frag_size;
1289 }
1290 cork->fragsize = mtu;
1291 if (dst_allfrag(rt->dst.path))
1292 cork->flags |= IPCORK_ALLFRAG;
1293 cork->length = 0;
1294 sk->sk_sndmsg_page = NULL;
1295 sk->sk_sndmsg_off = 0;
1296 exthdrlen = (opt ? opt->opt_flen : 0) - rt->rt6i_nfheader_len;
1297 length += exthdrlen;
1298 transhdrlen += exthdrlen;
1299 dst_exthdrlen = rt->dst.header_len;
1300 } else {
1301 rt = (struct rt6_info *)cork->dst;
1302 fl6 = &inet->cork.fl.u.ip6;
1303 opt = np->cork.opt;
1304 transhdrlen = 0;
1305 exthdrlen = 0;
1306 dst_exthdrlen = 0;
1307 mtu = cork->fragsize;
1308 }
1309
1310 hh_len = LL_RESERVED_SPACE(rt->dst.dev);
1311
1312 fragheaderlen = sizeof(struct ipv6hdr) + rt->rt6i_nfheader_len +
1313 (opt ? opt->opt_nflen : 0);
1314 maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - sizeof(struct frag_hdr);
1315
1316 if (mtu <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN) {
1317 if (cork->length + length > sizeof(struct ipv6hdr) + IPV6_MAXPLEN - fragheaderlen) {
1318 ipv6_local_error(sk, EMSGSIZE, fl6, mtu-exthdrlen);
1319 return -EMSGSIZE;
1320 }
1321 }
1322
1323 /* For UDP, check if TX timestamp is enabled */
1324 if (sk->sk_type == SOCK_DGRAM) {
1325 err = sock_tx_timestamp(sk, &tx_flags);
1326 if (err)
1327 goto error;
1328 }
1329
1330 /*
1331 * Let's try using as much space as possible.
1332 * Use MTU if total length of the message fits into the MTU.
1333 * Otherwise, we need to reserve fragment header and
1334 * fragment alignment (= 8-15 octects, in total).
1335 *
1336 * Note that we may need to "move" the data from the tail of
1337 * of the buffer to the new fragment when we split
1338 * the message.
1339 *
1340 * FIXME: It may be fragmented into multiple chunks
1341 * at once if non-fragmentable extension headers
1342 * are too large.
1343 * --yoshfuji
1344 */
1345
1346 cork->length += length;
1347 if (length > mtu) {
1348 int proto = sk->sk_protocol;
1349 if (dontfrag && (proto == IPPROTO_UDP || proto == IPPROTO_RAW)){
1350 ipv6_local_rxpmtu(sk, fl6, mtu-exthdrlen);
1351 return -EMSGSIZE;
1352 }
1353
1354 if (proto == IPPROTO_UDP &&
1355 (rt->dst.dev->features & NETIF_F_UFO)) {
1356
1357 err = ip6_ufo_append_data(sk, getfrag, from, length,
1358 hh_len, fragheaderlen,
1359 transhdrlen, mtu, flags, rt);
1360 if (err)
1361 goto error;
1362 return 0;
1363 }
1364 }
1365
1366 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL)
1367 goto alloc_new_skb;
1368
1369 while (length > 0) {
1370 /* Check if the remaining data fits into current packet. */
1371 copy = (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len;
1372 if (copy < length)
1373 copy = maxfraglen - skb->len;
1374
1375 if (copy <= 0) {
1376 char *data;
1377 unsigned int datalen;
1378 unsigned int fraglen;
1379 unsigned int fraggap;
1380 unsigned int alloclen;
1381 alloc_new_skb:
1382 /* There's no room in the current skb */
1383 if (skb)
1384 fraggap = skb->len - maxfraglen;
1385 else
1386 fraggap = 0;
1387 /* update mtu and maxfraglen if necessary */
1388 if (skb == NULL || skb_prev == NULL)
1389 ip6_append_data_mtu(&mtu, &maxfraglen,
1390 fragheaderlen, skb, rt);
1391
1392 skb_prev = skb;
1393
1394 /*
1395 * If remaining data exceeds the mtu,
1396 * we know we need more fragment(s).
1397 */
1398 datalen = length + fraggap;
1399
1400 if (datalen > (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen)
1401 datalen = maxfraglen - fragheaderlen - rt->dst.trailer_len;
1402 if ((flags & MSG_MORE) &&
1403 !(rt->dst.dev->features&NETIF_F_SG))
1404 alloclen = mtu;
1405 else
1406 alloclen = datalen + fragheaderlen;
1407
1408 alloclen += dst_exthdrlen;
1409
1410 if (datalen != length + fraggap) {
1411 /*
1412 * this is not the last fragment, the trailer
1413 * space is regarded as data space.
1414 */
1415 datalen += rt->dst.trailer_len;
1416 }
1417
1418 alloclen += rt->dst.trailer_len;
1419 fraglen = datalen + fragheaderlen;
1420
1421 /*
1422 * We just reserve space for fragment header.
1423 * Note: this may be overallocation if the message
1424 * (without MSG_MORE) fits into the MTU.
1425 */
1426 alloclen += sizeof(struct frag_hdr);
1427
1428 if (transhdrlen) {
1429 skb = sock_alloc_send_skb(sk,
1430 alloclen + hh_len,
1431 (flags & MSG_DONTWAIT), &err);
1432 } else {
1433 skb = NULL;
1434 if (atomic_read(&sk->sk_wmem_alloc) <=
1435 2 * sk->sk_sndbuf)
1436 skb = sock_wmalloc(sk,
1437 alloclen + hh_len, 1,
1438 sk->sk_allocation);
1439 if (unlikely(skb == NULL))
1440 err = -ENOBUFS;
1441 else {
1442 /* Only the initial fragment
1443 * is time stamped.
1444 */
1445 tx_flags = 0;
1446 }
1447 }
1448 if (skb == NULL)
1449 goto error;
1450 /*
1451 * Fill in the control structures
1452 */
1453 skb->ip_summed = CHECKSUM_NONE;
1454 skb->csum = 0;
1455 /* reserve for fragmentation and ipsec header */
1456 skb_reserve(skb, hh_len + sizeof(struct frag_hdr) +
1457 dst_exthdrlen);
1458
1459 if (sk->sk_type == SOCK_DGRAM)
1460 skb_shinfo(skb)->tx_flags = tx_flags;
1461
1462 /*
1463 * Find where to start putting bytes
1464 */
1465 data = skb_put(skb, fraglen);
1466 skb_set_network_header(skb, exthdrlen);
1467 data += fragheaderlen;
1468 skb->transport_header = (skb->network_header +
1469 fragheaderlen);
1470 if (fraggap) {
1471 skb->csum = skb_copy_and_csum_bits(
1472 skb_prev, maxfraglen,
1473 data + transhdrlen, fraggap, 0);
1474 skb_prev->csum = csum_sub(skb_prev->csum,
1475 skb->csum);
1476 data += fraggap;
1477 pskb_trim_unique(skb_prev, maxfraglen);
1478 }
1479 copy = datalen - transhdrlen - fraggap;
1480
1481 if (copy < 0) {
1482 err = -EINVAL;
1483 kfree_skb(skb);
1484 goto error;
1485 } else if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) {
1486 err = -EFAULT;
1487 kfree_skb(skb);
1488 goto error;
1489 }
1490
1491 offset += copy;
1492 length -= datalen - fraggap;
1493 transhdrlen = 0;
1494 exthdrlen = 0;
1495 dst_exthdrlen = 0;
1496
1497 /*
1498 * Put the packet on the pending queue
1499 */
1500 __skb_queue_tail(&sk->sk_write_queue, skb);
1501 continue;
1502 }
1503
1504 if (copy > length)
1505 copy = length;
1506
1507 if (!(rt->dst.dev->features&NETIF_F_SG)) {
1508 unsigned int off;
1509
1510 off = skb->len;
1511 if (getfrag(from, skb_put(skb, copy),
1512 offset, copy, off, skb) < 0) {
1513 __skb_trim(skb, off);
1514 err = -EFAULT;
1515 goto error;
1516 }
1517 } else {
1518 int i = skb_shinfo(skb)->nr_frags;
1519 skb_frag_t *frag = &skb_shinfo(skb)->frags[i-1];
1520 struct page *page = sk->sk_sndmsg_page;
1521 int off = sk->sk_sndmsg_off;
1522 unsigned int left;
1523
1524 if (page && (left = PAGE_SIZE - off) > 0) {
1525 if (copy >= left)
1526 copy = left;
1527 if (page != skb_frag_page(frag)) {
1528 if (i == MAX_SKB_FRAGS) {
1529 err = -EMSGSIZE;
1530 goto error;
1531 }
1532 skb_fill_page_desc(skb, i, page, sk->sk_sndmsg_off, 0);
1533 skb_frag_ref(skb, i);
1534 frag = &skb_shinfo(skb)->frags[i];
1535 }
1536 } else if(i < MAX_SKB_FRAGS) {
1537 if (copy > PAGE_SIZE)
1538 copy = PAGE_SIZE;
1539 page = alloc_pages(sk->sk_allocation, 0);
1540 if (page == NULL) {
1541 err = -ENOMEM;
1542 goto error;
1543 }
1544 sk->sk_sndmsg_page = page;
1545 sk->sk_sndmsg_off = 0;
1546
1547 skb_fill_page_desc(skb, i, page, 0, 0);
1548 frag = &skb_shinfo(skb)->frags[i];
1549 } else {
1550 err = -EMSGSIZE;
1551 goto error;
1552 }
1553 if (getfrag(from,
1554 skb_frag_address(frag) + skb_frag_size(frag),
1555 offset, copy, skb->len, skb) < 0) {
1556 err = -EFAULT;
1557 goto error;
1558 }
1559 sk->sk_sndmsg_off += copy;
1560 skb_frag_size_add(frag, copy);
1561 skb->len += copy;
1562 skb->data_len += copy;
1563 skb->truesize += copy;
1564 atomic_add(copy, &sk->sk_wmem_alloc);
1565 }
1566 offset += copy;
1567 length -= copy;
1568 }
1569 return 0;
1570 error:
1571 cork->length -= length;
1572 IP6_INC_STATS(sock_net(sk), rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS);
1573 return err;
1574 }
1575 EXPORT_SYMBOL_GPL(ip6_append_data);
1576
1577 static void ip6_cork_release(struct inet_sock *inet, struct ipv6_pinfo *np)
1578 {
1579 if (np->cork.opt) {
1580 kfree(np->cork.opt->dst0opt);
1581 kfree(np->cork.opt->dst1opt);
1582 kfree(np->cork.opt->hopopt);
1583 kfree(np->cork.opt->srcrt);
1584 kfree(np->cork.opt);
1585 np->cork.opt = NULL;
1586 }
1587
1588 if (inet->cork.base.dst) {
1589 dst_release(inet->cork.base.dst);
1590 inet->cork.base.dst = NULL;
1591 inet->cork.base.flags &= ~IPCORK_ALLFRAG;
1592 }
1593 memset(&inet->cork.fl, 0, sizeof(inet->cork.fl));
1594 }
1595
1596 int ip6_push_pending_frames(struct sock *sk)
1597 {
1598 struct sk_buff *skb, *tmp_skb;
1599 struct sk_buff **tail_skb;
1600 struct in6_addr final_dst_buf, *final_dst = &final_dst_buf;
1601 struct inet_sock *inet = inet_sk(sk);
1602 struct ipv6_pinfo *np = inet6_sk(sk);
1603 struct net *net = sock_net(sk);
1604 struct ipv6hdr *hdr;
1605 struct ipv6_txoptions *opt = np->cork.opt;
1606 struct rt6_info *rt = (struct rt6_info *)inet->cork.base.dst;
1607 struct flowi6 *fl6 = &inet->cork.fl.u.ip6;
1608 unsigned char proto = fl6->flowi6_proto;
1609 int err = 0;
1610
1611 if ((skb = __skb_dequeue(&sk->sk_write_queue)) == NULL)
1612 goto out;
1613 tail_skb = &(skb_shinfo(skb)->frag_list);
1614
1615 /* move skb->data to ip header from ext header */
1616 if (skb->data < skb_network_header(skb))
1617 __skb_pull(skb, skb_network_offset(skb));
1618 while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) {
1619 __skb_pull(tmp_skb, skb_network_header_len(skb));
1620 *tail_skb = tmp_skb;
1621 tail_skb = &(tmp_skb->next);
1622 skb->len += tmp_skb->len;
1623 skb->data_len += tmp_skb->len;
1624 skb->truesize += tmp_skb->truesize;
1625 tmp_skb->destructor = NULL;
1626 tmp_skb->sk = NULL;
1627 }
1628
1629 /* Allow local fragmentation. */
1630 if (np->pmtudisc < IPV6_PMTUDISC_DO)
1631 skb->local_df = 1;
1632
1633 *final_dst = fl6->daddr;
1634 __skb_pull(skb, skb_network_header_len(skb));
1635 if (opt && opt->opt_flen)
1636 ipv6_push_frag_opts(skb, opt, &proto);
1637 if (opt && opt->opt_nflen)
1638 ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst);
1639
1640 skb_push(skb, sizeof(struct ipv6hdr));
1641 skb_reset_network_header(skb);
1642 hdr = ipv6_hdr(skb);
1643
1644 *(__be32*)hdr = fl6->flowlabel |
1645 htonl(0x60000000 | ((int)np->cork.tclass << 20));
1646
1647 hdr->hop_limit = np->cork.hop_limit;
1648 hdr->nexthdr = proto;
1649 hdr->saddr = fl6->saddr;
1650 hdr->daddr = *final_dst;
1651
1652 skb->priority = sk->sk_priority;
1653 skb->mark = sk->sk_mark;
1654
1655 skb_dst_set(skb, dst_clone(&rt->dst));
1656 IP6_UPD_PO_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUT, skb->len);
1657 if (proto == IPPROTO_ICMPV6) {
1658 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
1659
1660 ICMP6MSGOUT_INC_STATS_BH(net, idev, icmp6_hdr(skb)->icmp6_type);
1661 ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTMSGS);
1662 }
1663
1664 err = ip6_local_out(skb);
1665 if (err) {
1666 if (err > 0)
1667 err = net_xmit_errno(err);
1668 if (err)
1669 goto error;
1670 }
1671
1672 out:
1673 ip6_cork_release(inet, np);
1674 return err;
1675 error:
1676 IP6_INC_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS);
1677 goto out;
1678 }
1679 EXPORT_SYMBOL_GPL(ip6_push_pending_frames);
1680
1681 void ip6_flush_pending_frames(struct sock *sk)
1682 {
1683 struct sk_buff *skb;
1684
1685 while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) {
1686 if (skb_dst(skb))
1687 IP6_INC_STATS(sock_net(sk), ip6_dst_idev(skb_dst(skb)),
1688 IPSTATS_MIB_OUTDISCARDS);
1689 kfree_skb(skb);
1690 }
1691
1692 ip6_cork_release(inet_sk(sk), inet6_sk(sk));
1693 }
1694 EXPORT_SYMBOL_GPL(ip6_flush_pending_frames);
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