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Merge tag 'for-f2fs-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk...
[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 #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 static int ip6_finish_output2(struct sock *sk, struct sk_buff *skb)
60 {
61 struct dst_entry *dst = skb_dst(skb);
62 struct net_device *dev = dst->dev;
63 struct neighbour *neigh;
64 struct in6_addr *nexthop;
65 int ret;
66
67 skb->protocol = htons(ETH_P_IPV6);
68 skb->dev = dev;
69
70 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) {
71 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
72
73 if (!(dev->flags & IFF_LOOPBACK) && sk_mc_loop(sk) &&
74 ((mroute6_socket(dev_net(dev), skb) &&
75 !(IP6CB(skb)->flags & IP6SKB_FORWARDED)) ||
76 ipv6_chk_mcast_addr(dev, &ipv6_hdr(skb)->daddr,
77 &ipv6_hdr(skb)->saddr))) {
78 struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC);
79
80 /* Do not check for IFF_ALLMULTI; multicast routing
81 is not supported in any case.
82 */
83 if (newskb)
84 NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING,
85 sk, newskb, NULL, newskb->dev,
86 dev_loopback_xmit);
87
88 if (ipv6_hdr(skb)->hop_limit == 0) {
89 IP6_INC_STATS(dev_net(dev), idev,
90 IPSTATS_MIB_OUTDISCARDS);
91 kfree_skb(skb);
92 return 0;
93 }
94 }
95
96 IP6_UPD_PO_STATS(dev_net(dev), idev, IPSTATS_MIB_OUTMCAST,
97 skb->len);
98
99 if (IPV6_ADDR_MC_SCOPE(&ipv6_hdr(skb)->daddr) <=
100 IPV6_ADDR_SCOPE_NODELOCAL &&
101 !(dev->flags & IFF_LOOPBACK)) {
102 kfree_skb(skb);
103 return 0;
104 }
105 }
106
107 rcu_read_lock_bh();
108 nexthop = rt6_nexthop((struct rt6_info *)dst, &ipv6_hdr(skb)->daddr);
109 neigh = __ipv6_neigh_lookup_noref(dst->dev, nexthop);
110 if (unlikely(!neigh))
111 neigh = __neigh_create(&nd_tbl, nexthop, dst->dev, false);
112 if (!IS_ERR(neigh)) {
113 ret = dst_neigh_output(dst, neigh, skb);
114 rcu_read_unlock_bh();
115 return ret;
116 }
117 rcu_read_unlock_bh();
118
119 IP6_INC_STATS(dev_net(dst->dev),
120 ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
121 kfree_skb(skb);
122 return -EINVAL;
123 }
124
125 static int ip6_finish_output(struct sock *sk, struct sk_buff *skb)
126 {
127 if ((skb->len > ip6_skb_dst_mtu(skb) && !skb_is_gso(skb)) ||
128 dst_allfrag(skb_dst(skb)) ||
129 (IP6CB(skb)->frag_max_size && skb->len > IP6CB(skb)->frag_max_size))
130 return ip6_fragment(sk, skb, ip6_finish_output2);
131 else
132 return ip6_finish_output2(sk, skb);
133 }
134
135 int ip6_output(struct sock *sk, struct sk_buff *skb)
136 {
137 struct net_device *dev = skb_dst(skb)->dev;
138 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
139 if (unlikely(idev->cnf.disable_ipv6)) {
140 IP6_INC_STATS(dev_net(dev), idev,
141 IPSTATS_MIB_OUTDISCARDS);
142 kfree_skb(skb);
143 return 0;
144 }
145
146 return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING, sk, skb,
147 NULL, dev,
148 ip6_finish_output,
149 !(IP6CB(skb)->flags & IP6SKB_REROUTED));
150 }
151
152 /*
153 * xmit an sk_buff (used by TCP, SCTP and DCCP)
154 */
155
156 int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
157 struct ipv6_txoptions *opt, int tclass)
158 {
159 struct net *net = sock_net(sk);
160 struct ipv6_pinfo *np = inet6_sk(sk);
161 struct in6_addr *first_hop = &fl6->daddr;
162 struct dst_entry *dst = skb_dst(skb);
163 struct ipv6hdr *hdr;
164 u8 proto = fl6->flowi6_proto;
165 int seg_len = skb->len;
166 int hlimit = -1;
167 u32 mtu;
168
169 if (opt) {
170 unsigned int head_room;
171
172 /* First: exthdrs may take lots of space (~8K for now)
173 MAX_HEADER is not enough.
174 */
175 head_room = opt->opt_nflen + opt->opt_flen;
176 seg_len += head_room;
177 head_room += sizeof(struct ipv6hdr) + LL_RESERVED_SPACE(dst->dev);
178
179 if (skb_headroom(skb) < head_room) {
180 struct sk_buff *skb2 = skb_realloc_headroom(skb, head_room);
181 if (!skb2) {
182 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
183 IPSTATS_MIB_OUTDISCARDS);
184 kfree_skb(skb);
185 return -ENOBUFS;
186 }
187 consume_skb(skb);
188 skb = skb2;
189 skb_set_owner_w(skb, sk);
190 }
191 if (opt->opt_flen)
192 ipv6_push_frag_opts(skb, opt, &proto);
193 if (opt->opt_nflen)
194 ipv6_push_nfrag_opts(skb, opt, &proto, &first_hop);
195 }
196
197 skb_push(skb, sizeof(struct ipv6hdr));
198 skb_reset_network_header(skb);
199 hdr = ipv6_hdr(skb);
200
201 /*
202 * Fill in the IPv6 header
203 */
204 if (np)
205 hlimit = np->hop_limit;
206 if (hlimit < 0)
207 hlimit = ip6_dst_hoplimit(dst);
208
209 ip6_flow_hdr(hdr, tclass, ip6_make_flowlabel(net, skb, fl6->flowlabel,
210 np->autoflowlabel, fl6));
211
212 hdr->payload_len = htons(seg_len);
213 hdr->nexthdr = proto;
214 hdr->hop_limit = hlimit;
215
216 hdr->saddr = fl6->saddr;
217 hdr->daddr = *first_hop;
218
219 skb->protocol = htons(ETH_P_IPV6);
220 skb->priority = sk->sk_priority;
221 skb->mark = sk->sk_mark;
222
223 mtu = dst_mtu(dst);
224 if ((skb->len <= mtu) || skb->ignore_df || skb_is_gso(skb)) {
225 IP6_UPD_PO_STATS(net, ip6_dst_idev(skb_dst(skb)),
226 IPSTATS_MIB_OUT, skb->len);
227 return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, sk, skb,
228 NULL, dst->dev, dst_output_sk);
229 }
230
231 skb->dev = dst->dev;
232 ipv6_local_error(sk, EMSGSIZE, fl6, mtu);
233 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_FRAGFAILS);
234 kfree_skb(skb);
235 return -EMSGSIZE;
236 }
237 EXPORT_SYMBOL(ip6_xmit);
238
239 static int ip6_call_ra_chain(struct sk_buff *skb, int sel)
240 {
241 struct ip6_ra_chain *ra;
242 struct sock *last = NULL;
243
244 read_lock(&ip6_ra_lock);
245 for (ra = ip6_ra_chain; ra; ra = ra->next) {
246 struct sock *sk = ra->sk;
247 if (sk && ra->sel == sel &&
248 (!sk->sk_bound_dev_if ||
249 sk->sk_bound_dev_if == skb->dev->ifindex)) {
250 if (last) {
251 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
252 if (skb2)
253 rawv6_rcv(last, skb2);
254 }
255 last = sk;
256 }
257 }
258
259 if (last) {
260 rawv6_rcv(last, skb);
261 read_unlock(&ip6_ra_lock);
262 return 1;
263 }
264 read_unlock(&ip6_ra_lock);
265 return 0;
266 }
267
268 static int ip6_forward_proxy_check(struct sk_buff *skb)
269 {
270 struct ipv6hdr *hdr = ipv6_hdr(skb);
271 u8 nexthdr = hdr->nexthdr;
272 __be16 frag_off;
273 int offset;
274
275 if (ipv6_ext_hdr(nexthdr)) {
276 offset = ipv6_skip_exthdr(skb, sizeof(*hdr), &nexthdr, &frag_off);
277 if (offset < 0)
278 return 0;
279 } else
280 offset = sizeof(struct ipv6hdr);
281
282 if (nexthdr == IPPROTO_ICMPV6) {
283 struct icmp6hdr *icmp6;
284
285 if (!pskb_may_pull(skb, (skb_network_header(skb) +
286 offset + 1 - skb->data)))
287 return 0;
288
289 icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset);
290
291 switch (icmp6->icmp6_type) {
292 case NDISC_ROUTER_SOLICITATION:
293 case NDISC_ROUTER_ADVERTISEMENT:
294 case NDISC_NEIGHBOUR_SOLICITATION:
295 case NDISC_NEIGHBOUR_ADVERTISEMENT:
296 case NDISC_REDIRECT:
297 /* For reaction involving unicast neighbor discovery
298 * message destined to the proxied address, pass it to
299 * input function.
300 */
301 return 1;
302 default:
303 break;
304 }
305 }
306
307 /*
308 * The proxying router can't forward traffic sent to a link-local
309 * address, so signal the sender and discard the packet. This
310 * behavior is clarified by the MIPv6 specification.
311 */
312 if (ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) {
313 dst_link_failure(skb);
314 return -1;
315 }
316
317 return 0;
318 }
319
320 static inline int ip6_forward_finish(struct sock *sk, struct sk_buff *skb)
321 {
322 skb_sender_cpu_clear(skb);
323 return dst_output_sk(sk, skb);
324 }
325
326 static unsigned int ip6_dst_mtu_forward(const struct dst_entry *dst)
327 {
328 unsigned int mtu;
329 struct inet6_dev *idev;
330
331 if (dst_metric_locked(dst, RTAX_MTU)) {
332 mtu = dst_metric_raw(dst, RTAX_MTU);
333 if (mtu)
334 return mtu;
335 }
336
337 mtu = IPV6_MIN_MTU;
338 rcu_read_lock();
339 idev = __in6_dev_get(dst->dev);
340 if (idev)
341 mtu = idev->cnf.mtu6;
342 rcu_read_unlock();
343
344 return mtu;
345 }
346
347 static bool ip6_pkt_too_big(const struct sk_buff *skb, unsigned int mtu)
348 {
349 if (skb->len <= mtu)
350 return false;
351
352 /* ipv6 conntrack defrag sets max_frag_size + ignore_df */
353 if (IP6CB(skb)->frag_max_size && IP6CB(skb)->frag_max_size > mtu)
354 return true;
355
356 if (skb->ignore_df)
357 return false;
358
359 if (skb_is_gso(skb) && skb_gso_network_seglen(skb) <= mtu)
360 return false;
361
362 return true;
363 }
364
365 int ip6_forward(struct sk_buff *skb)
366 {
367 struct dst_entry *dst = skb_dst(skb);
368 struct ipv6hdr *hdr = ipv6_hdr(skb);
369 struct inet6_skb_parm *opt = IP6CB(skb);
370 struct net *net = dev_net(dst->dev);
371 u32 mtu;
372
373 if (net->ipv6.devconf_all->forwarding == 0)
374 goto error;
375
376 if (skb->pkt_type != PACKET_HOST)
377 goto drop;
378
379 if (skb_warn_if_lro(skb))
380 goto drop;
381
382 if (!xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) {
383 IP6_INC_STATS_BH(net, ip6_dst_idev(dst),
384 IPSTATS_MIB_INDISCARDS);
385 goto drop;
386 }
387
388 skb_forward_csum(skb);
389
390 /*
391 * We DO NOT make any processing on
392 * RA packets, pushing them to user level AS IS
393 * without ane WARRANTY that application will be able
394 * to interpret them. The reason is that we
395 * cannot make anything clever here.
396 *
397 * We are not end-node, so that if packet contains
398 * AH/ESP, we cannot make anything.
399 * Defragmentation also would be mistake, RA packets
400 * cannot be fragmented, because there is no warranty
401 * that different fragments will go along one path. --ANK
402 */
403 if (unlikely(opt->flags & IP6SKB_ROUTERALERT)) {
404 if (ip6_call_ra_chain(skb, ntohs(opt->ra)))
405 return 0;
406 }
407
408 /*
409 * check and decrement ttl
410 */
411 if (hdr->hop_limit <= 1) {
412 /* Force OUTPUT device used as source address */
413 skb->dev = dst->dev;
414 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 0);
415 IP6_INC_STATS_BH(net, ip6_dst_idev(dst),
416 IPSTATS_MIB_INHDRERRORS);
417
418 kfree_skb(skb);
419 return -ETIMEDOUT;
420 }
421
422 /* XXX: idev->cnf.proxy_ndp? */
423 if (net->ipv6.devconf_all->proxy_ndp &&
424 pneigh_lookup(&nd_tbl, net, &hdr->daddr, skb->dev, 0)) {
425 int proxied = ip6_forward_proxy_check(skb);
426 if (proxied > 0)
427 return ip6_input(skb);
428 else if (proxied < 0) {
429 IP6_INC_STATS_BH(net, ip6_dst_idev(dst),
430 IPSTATS_MIB_INDISCARDS);
431 goto drop;
432 }
433 }
434
435 if (!xfrm6_route_forward(skb)) {
436 IP6_INC_STATS_BH(net, ip6_dst_idev(dst),
437 IPSTATS_MIB_INDISCARDS);
438 goto drop;
439 }
440 dst = skb_dst(skb);
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 && opt->srcrt == 0 && !skb_sec_path(skb)) {
447 struct in6_addr *target = NULL;
448 struct inet_peer *peer;
449 struct rt6_info *rt;
450
451 /*
452 * incoming and outgoing devices are the same
453 * send a redirect.
454 */
455
456 rt = (struct rt6_info *) dst;
457 if (rt->rt6i_flags & RTF_GATEWAY)
458 target = &rt->rt6i_gateway;
459 else
460 target = &hdr->daddr;
461
462 peer = inet_getpeer_v6(net->ipv6.peers, &hdr->daddr, 1);
463
464 /* Limit redirects both by destination (here)
465 and by source (inside ndisc_send_redirect)
466 */
467 if (inet_peer_xrlim_allow(peer, 1*HZ))
468 ndisc_send_redirect(skb, target);
469 if (peer)
470 inet_putpeer(peer);
471 } else {
472 int addrtype = ipv6_addr_type(&hdr->saddr);
473
474 /* This check is security critical. */
475 if (addrtype == IPV6_ADDR_ANY ||
476 addrtype & (IPV6_ADDR_MULTICAST | IPV6_ADDR_LOOPBACK))
477 goto error;
478 if (addrtype & IPV6_ADDR_LINKLOCAL) {
479 icmpv6_send(skb, ICMPV6_DEST_UNREACH,
480 ICMPV6_NOT_NEIGHBOUR, 0);
481 goto error;
482 }
483 }
484
485 mtu = ip6_dst_mtu_forward(dst);
486 if (mtu < IPV6_MIN_MTU)
487 mtu = IPV6_MIN_MTU;
488
489 if (ip6_pkt_too_big(skb, mtu)) {
490 /* Again, force OUTPUT device used as source address */
491 skb->dev = dst->dev;
492 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
493 IP6_INC_STATS_BH(net, ip6_dst_idev(dst),
494 IPSTATS_MIB_INTOOBIGERRORS);
495 IP6_INC_STATS_BH(net, ip6_dst_idev(dst),
496 IPSTATS_MIB_FRAGFAILS);
497 kfree_skb(skb);
498 return -EMSGSIZE;
499 }
500
501 if (skb_cow(skb, dst->dev->hard_header_len)) {
502 IP6_INC_STATS_BH(net, ip6_dst_idev(dst),
503 IPSTATS_MIB_OUTDISCARDS);
504 goto drop;
505 }
506
507 hdr = ipv6_hdr(skb);
508
509 /* Mangling hops number delayed to point after skb COW */
510
511 hdr->hop_limit--;
512
513 IP6_INC_STATS_BH(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTFORWDATAGRAMS);
514 IP6_ADD_STATS_BH(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTOCTETS, skb->len);
515 return NF_HOOK(NFPROTO_IPV6, NF_INET_FORWARD, NULL, skb,
516 skb->dev, dst->dev,
517 ip6_forward_finish);
518
519 error:
520 IP6_INC_STATS_BH(net, ip6_dst_idev(dst), IPSTATS_MIB_INADDRERRORS);
521 drop:
522 kfree_skb(skb);
523 return -EINVAL;
524 }
525
526 static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from)
527 {
528 to->pkt_type = from->pkt_type;
529 to->priority = from->priority;
530 to->protocol = from->protocol;
531 skb_dst_drop(to);
532 skb_dst_set(to, dst_clone(skb_dst(from)));
533 to->dev = from->dev;
534 to->mark = from->mark;
535
536 #ifdef CONFIG_NET_SCHED
537 to->tc_index = from->tc_index;
538 #endif
539 nf_copy(to, from);
540 skb_copy_secmark(to, from);
541 }
542
543 int ip6_fragment(struct sock *sk, struct sk_buff *skb,
544 int (*output)(struct sock *, struct sk_buff *))
545 {
546 struct sk_buff *frag;
547 struct rt6_info *rt = (struct rt6_info *)skb_dst(skb);
548 struct ipv6_pinfo *np = skb->sk && !dev_recursion_level() ?
549 inet6_sk(skb->sk) : NULL;
550 struct ipv6hdr *tmp_hdr;
551 struct frag_hdr *fh;
552 unsigned int mtu, hlen, left, len;
553 int hroom, troom;
554 __be32 frag_id;
555 int ptr, offset = 0, err = 0;
556 u8 *prevhdr, nexthdr = 0;
557 struct net *net = dev_net(skb_dst(skb)->dev);
558
559 hlen = ip6_find_1stfragopt(skb, &prevhdr);
560 nexthdr = *prevhdr;
561
562 mtu = ip6_skb_dst_mtu(skb);
563
564 /* We must not fragment if the socket is set to force MTU discovery
565 * or if the skb it not generated by a local socket.
566 */
567 if (unlikely(!skb->ignore_df && skb->len > mtu))
568 goto fail_toobig;
569
570 if (IP6CB(skb)->frag_max_size) {
571 if (IP6CB(skb)->frag_max_size > mtu)
572 goto fail_toobig;
573
574 /* don't send fragments larger than what we received */
575 mtu = IP6CB(skb)->frag_max_size;
576 if (mtu < IPV6_MIN_MTU)
577 mtu = IPV6_MIN_MTU;
578 }
579
580 if (np && np->frag_size < mtu) {
581 if (np->frag_size)
582 mtu = np->frag_size;
583 }
584 mtu -= hlen + sizeof(struct frag_hdr);
585
586 frag_id = ipv6_select_ident(net, &ipv6_hdr(skb)->daddr,
587 &ipv6_hdr(skb)->saddr);
588
589 if (skb_has_frag_list(skb)) {
590 int first_len = skb_pagelen(skb);
591 struct sk_buff *frag2;
592
593 if (first_len - hlen > mtu ||
594 ((first_len - hlen) & 7) ||
595 skb_cloned(skb))
596 goto slow_path;
597
598 skb_walk_frags(skb, frag) {
599 /* Correct geometry. */
600 if (frag->len > mtu ||
601 ((frag->len & 7) && frag->next) ||
602 skb_headroom(frag) < hlen)
603 goto slow_path_clean;
604
605 /* Partially cloned skb? */
606 if (skb_shared(frag))
607 goto slow_path_clean;
608
609 BUG_ON(frag->sk);
610 if (skb->sk) {
611 frag->sk = skb->sk;
612 frag->destructor = sock_wfree;
613 }
614 skb->truesize -= frag->truesize;
615 }
616
617 err = 0;
618 offset = 0;
619 frag = skb_shinfo(skb)->frag_list;
620 skb_frag_list_init(skb);
621 /* BUILD HEADER */
622
623 *prevhdr = NEXTHDR_FRAGMENT;
624 tmp_hdr = kmemdup(skb_network_header(skb), hlen, GFP_ATOMIC);
625 if (!tmp_hdr) {
626 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
627 IPSTATS_MIB_FRAGFAILS);
628 return -ENOMEM;
629 }
630
631 __skb_pull(skb, hlen);
632 fh = (struct frag_hdr *)__skb_push(skb, sizeof(struct frag_hdr));
633 __skb_push(skb, hlen);
634 skb_reset_network_header(skb);
635 memcpy(skb_network_header(skb), tmp_hdr, hlen);
636
637 fh->nexthdr = nexthdr;
638 fh->reserved = 0;
639 fh->frag_off = htons(IP6_MF);
640 fh->identification = frag_id;
641
642 first_len = skb_pagelen(skb);
643 skb->data_len = first_len - skb_headlen(skb);
644 skb->len = first_len;
645 ipv6_hdr(skb)->payload_len = htons(first_len -
646 sizeof(struct ipv6hdr));
647
648 dst_hold(&rt->dst);
649
650 for (;;) {
651 /* Prepare header of the next frame,
652 * before previous one went down. */
653 if (frag) {
654 frag->ip_summed = CHECKSUM_NONE;
655 skb_reset_transport_header(frag);
656 fh = (struct frag_hdr *)__skb_push(frag, sizeof(struct frag_hdr));
657 __skb_push(frag, hlen);
658 skb_reset_network_header(frag);
659 memcpy(skb_network_header(frag), tmp_hdr,
660 hlen);
661 offset += skb->len - hlen - sizeof(struct frag_hdr);
662 fh->nexthdr = nexthdr;
663 fh->reserved = 0;
664 fh->frag_off = htons(offset);
665 if (frag->next)
666 fh->frag_off |= htons(IP6_MF);
667 fh->identification = frag_id;
668 ipv6_hdr(frag)->payload_len =
669 htons(frag->len -
670 sizeof(struct ipv6hdr));
671 ip6_copy_metadata(frag, skb);
672 }
673
674 err = output(sk, skb);
675 if (!err)
676 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
677 IPSTATS_MIB_FRAGCREATES);
678
679 if (err || !frag)
680 break;
681
682 skb = frag;
683 frag = skb->next;
684 skb->next = NULL;
685 }
686
687 kfree(tmp_hdr);
688
689 if (err == 0) {
690 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
691 IPSTATS_MIB_FRAGOKS);
692 ip6_rt_put(rt);
693 return 0;
694 }
695
696 kfree_skb_list(frag);
697
698 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
699 IPSTATS_MIB_FRAGFAILS);
700 ip6_rt_put(rt);
701 return err;
702
703 slow_path_clean:
704 skb_walk_frags(skb, frag2) {
705 if (frag2 == frag)
706 break;
707 frag2->sk = NULL;
708 frag2->destructor = NULL;
709 skb->truesize += frag2->truesize;
710 }
711 }
712
713 slow_path:
714 if ((skb->ip_summed == CHECKSUM_PARTIAL) &&
715 skb_checksum_help(skb))
716 goto fail;
717
718 left = skb->len - hlen; /* Space per frame */
719 ptr = hlen; /* Where to start from */
720
721 /*
722 * Fragment the datagram.
723 */
724
725 *prevhdr = NEXTHDR_FRAGMENT;
726 hroom = LL_RESERVED_SPACE(rt->dst.dev);
727 troom = rt->dst.dev->needed_tailroom;
728
729 /*
730 * Keep copying data until we run out.
731 */
732 while (left > 0) {
733 len = left;
734 /* IF: it doesn't fit, use 'mtu' - the data space left */
735 if (len > mtu)
736 len = mtu;
737 /* IF: we are not sending up to and including the packet end
738 then align the next start on an eight byte boundary */
739 if (len < left) {
740 len &= ~7;
741 }
742
743 /* Allocate buffer */
744 frag = alloc_skb(len + hlen + sizeof(struct frag_hdr) +
745 hroom + troom, GFP_ATOMIC);
746 if (!frag) {
747 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
748 IPSTATS_MIB_FRAGFAILS);
749 err = -ENOMEM;
750 goto fail;
751 }
752
753 /*
754 * Set up data on packet
755 */
756
757 ip6_copy_metadata(frag, skb);
758 skb_reserve(frag, hroom);
759 skb_put(frag, len + hlen + sizeof(struct frag_hdr));
760 skb_reset_network_header(frag);
761 fh = (struct frag_hdr *)(skb_network_header(frag) + hlen);
762 frag->transport_header = (frag->network_header + hlen +
763 sizeof(struct frag_hdr));
764
765 /*
766 * Charge the memory for the fragment to any owner
767 * it might possess
768 */
769 if (skb->sk)
770 skb_set_owner_w(frag, skb->sk);
771
772 /*
773 * Copy the packet header into the new buffer.
774 */
775 skb_copy_from_linear_data(skb, skb_network_header(frag), hlen);
776
777 /*
778 * Build fragment header.
779 */
780 fh->nexthdr = nexthdr;
781 fh->reserved = 0;
782 fh->identification = frag_id;
783
784 /*
785 * Copy a block of the IP datagram.
786 */
787 BUG_ON(skb_copy_bits(skb, ptr, skb_transport_header(frag),
788 len));
789 left -= len;
790
791 fh->frag_off = htons(offset);
792 if (left > 0)
793 fh->frag_off |= htons(IP6_MF);
794 ipv6_hdr(frag)->payload_len = htons(frag->len -
795 sizeof(struct ipv6hdr));
796
797 ptr += len;
798 offset += len;
799
800 /*
801 * Put this fragment into the sending queue.
802 */
803 err = output(sk, frag);
804 if (err)
805 goto fail;
806
807 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
808 IPSTATS_MIB_FRAGCREATES);
809 }
810 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
811 IPSTATS_MIB_FRAGOKS);
812 consume_skb(skb);
813 return err;
814
815 fail_toobig:
816 if (skb->sk && dst_allfrag(skb_dst(skb)))
817 sk_nocaps_add(skb->sk, NETIF_F_GSO_MASK);
818
819 skb->dev = skb_dst(skb)->dev;
820 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
821 err = -EMSGSIZE;
822
823 fail:
824 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
825 IPSTATS_MIB_FRAGFAILS);
826 kfree_skb(skb);
827 return err;
828 }
829
830 static inline int ip6_rt_check(const struct rt6key *rt_key,
831 const struct in6_addr *fl_addr,
832 const struct in6_addr *addr_cache)
833 {
834 return (rt_key->plen != 128 || !ipv6_addr_equal(fl_addr, &rt_key->addr)) &&
835 (!addr_cache || !ipv6_addr_equal(fl_addr, addr_cache));
836 }
837
838 static struct dst_entry *ip6_sk_dst_check(struct sock *sk,
839 struct dst_entry *dst,
840 const struct flowi6 *fl6)
841 {
842 struct ipv6_pinfo *np = inet6_sk(sk);
843 struct rt6_info *rt;
844
845 if (!dst)
846 goto out;
847
848 if (dst->ops->family != AF_INET6) {
849 dst_release(dst);
850 return NULL;
851 }
852
853 rt = (struct rt6_info *)dst;
854 /* Yes, checking route validity in not connected
855 * case is not very simple. Take into account,
856 * that we do not support routing by source, TOS,
857 * and MSG_DONTROUTE --ANK (980726)
858 *
859 * 1. ip6_rt_check(): If route was host route,
860 * check that cached destination is current.
861 * If it is network route, we still may
862 * check its validity using saved pointer
863 * to the last used address: daddr_cache.
864 * We do not want to save whole address now,
865 * (because main consumer of this service
866 * is tcp, which has not this problem),
867 * so that the last trick works only on connected
868 * sockets.
869 * 2. oif also should be the same.
870 */
871 if (ip6_rt_check(&rt->rt6i_dst, &fl6->daddr, np->daddr_cache) ||
872 #ifdef CONFIG_IPV6_SUBTREES
873 ip6_rt_check(&rt->rt6i_src, &fl6->saddr, np->saddr_cache) ||
874 #endif
875 (fl6->flowi6_oif && fl6->flowi6_oif != dst->dev->ifindex)) {
876 dst_release(dst);
877 dst = NULL;
878 }
879
880 out:
881 return dst;
882 }
883
884 static int ip6_dst_lookup_tail(struct net *net, struct sock *sk,
885 struct dst_entry **dst, struct flowi6 *fl6)
886 {
887 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
888 struct neighbour *n;
889 struct rt6_info *rt;
890 #endif
891 int err;
892
893 /* The correct way to handle this would be to do
894 * ip6_route_get_saddr, and then ip6_route_output; however,
895 * the route-specific preferred source forces the
896 * ip6_route_output call _before_ ip6_route_get_saddr.
897 *
898 * In source specific routing (no src=any default route),
899 * ip6_route_output will fail given src=any saddr, though, so
900 * that's why we try it again later.
901 */
902 if (ipv6_addr_any(&fl6->saddr) && (!*dst || !(*dst)->error)) {
903 struct rt6_info *rt;
904 bool had_dst = *dst != NULL;
905
906 if (!had_dst)
907 *dst = ip6_route_output(net, sk, fl6);
908 rt = (*dst)->error ? NULL : (struct rt6_info *)*dst;
909 err = ip6_route_get_saddr(net, rt, &fl6->daddr,
910 sk ? inet6_sk(sk)->srcprefs : 0,
911 &fl6->saddr);
912 if (err)
913 goto out_err_release;
914
915 /* If we had an erroneous initial result, pretend it
916 * never existed and let the SA-enabled version take
917 * over.
918 */
919 if (!had_dst && (*dst)->error) {
920 dst_release(*dst);
921 *dst = NULL;
922 }
923 }
924
925 if (!*dst)
926 *dst = ip6_route_output(net, sk, fl6);
927
928 err = (*dst)->error;
929 if (err)
930 goto out_err_release;
931
932 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
933 /*
934 * Here if the dst entry we've looked up
935 * has a neighbour entry that is in the INCOMPLETE
936 * state and the src address from the flow is
937 * marked as OPTIMISTIC, we release the found
938 * dst entry and replace it instead with the
939 * dst entry of the nexthop router
940 */
941 rt = (struct rt6_info *) *dst;
942 rcu_read_lock_bh();
943 n = __ipv6_neigh_lookup_noref(rt->dst.dev,
944 rt6_nexthop(rt, &fl6->daddr));
945 err = n && !(n->nud_state & NUD_VALID) ? -EINVAL : 0;
946 rcu_read_unlock_bh();
947
948 if (err) {
949 struct inet6_ifaddr *ifp;
950 struct flowi6 fl_gw6;
951 int redirect;
952
953 ifp = ipv6_get_ifaddr(net, &fl6->saddr,
954 (*dst)->dev, 1);
955
956 redirect = (ifp && ifp->flags & IFA_F_OPTIMISTIC);
957 if (ifp)
958 in6_ifa_put(ifp);
959
960 if (redirect) {
961 /*
962 * We need to get the dst entry for the
963 * default router instead
964 */
965 dst_release(*dst);
966 memcpy(&fl_gw6, fl6, sizeof(struct flowi6));
967 memset(&fl_gw6.daddr, 0, sizeof(struct in6_addr));
968 *dst = ip6_route_output(net, sk, &fl_gw6);
969 err = (*dst)->error;
970 if (err)
971 goto out_err_release;
972 }
973 }
974 #endif
975
976 return 0;
977
978 out_err_release:
979 if (err == -ENETUNREACH)
980 IP6_INC_STATS(net, NULL, IPSTATS_MIB_OUTNOROUTES);
981 dst_release(*dst);
982 *dst = NULL;
983 return err;
984 }
985
986 /**
987 * ip6_dst_lookup - perform route lookup on flow
988 * @sk: socket which provides route info
989 * @dst: pointer to dst_entry * for result
990 * @fl6: flow to lookup
991 *
992 * This function performs a route lookup on the given flow.
993 *
994 * It returns zero on success, or a standard errno code on error.
995 */
996 int ip6_dst_lookup(struct net *net, struct sock *sk, struct dst_entry **dst,
997 struct flowi6 *fl6)
998 {
999 *dst = NULL;
1000 return ip6_dst_lookup_tail(net, sk, dst, fl6);
1001 }
1002 EXPORT_SYMBOL_GPL(ip6_dst_lookup);
1003
1004 /**
1005 * ip6_dst_lookup_flow - perform route lookup on flow with ipsec
1006 * @sk: socket which provides route info
1007 * @fl6: flow to lookup
1008 * @final_dst: final destination address for ipsec lookup
1009 *
1010 * This function performs a route lookup on the given flow.
1011 *
1012 * It returns a valid dst pointer on success, or a pointer encoded
1013 * error code.
1014 */
1015 struct dst_entry *ip6_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
1016 const struct in6_addr *final_dst)
1017 {
1018 struct dst_entry *dst = NULL;
1019 int err;
1020
1021 err = ip6_dst_lookup_tail(sock_net(sk), sk, &dst, fl6);
1022 if (err)
1023 return ERR_PTR(err);
1024 if (final_dst)
1025 fl6->daddr = *final_dst;
1026 if (!fl6->flowi6_oif)
1027 fl6->flowi6_oif = dst->dev->ifindex;
1028
1029 return xfrm_lookup_route(sock_net(sk), dst, flowi6_to_flowi(fl6), sk, 0);
1030 }
1031 EXPORT_SYMBOL_GPL(ip6_dst_lookup_flow);
1032
1033 /**
1034 * ip6_sk_dst_lookup_flow - perform socket cached route lookup on flow
1035 * @sk: socket which provides the dst cache and route info
1036 * @fl6: flow to lookup
1037 * @final_dst: final destination address for ipsec lookup
1038 *
1039 * This function performs a route lookup on the given flow with the
1040 * possibility of using the cached route in the socket if it is valid.
1041 * It will take the socket dst lock when operating on the dst cache.
1042 * As a result, this function can only be used in process context.
1043 *
1044 * It returns a valid dst pointer on success, or a pointer encoded
1045 * error code.
1046 */
1047 struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
1048 const struct in6_addr *final_dst)
1049 {
1050 struct dst_entry *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie);
1051 int err;
1052
1053 dst = ip6_sk_dst_check(sk, dst, fl6);
1054
1055 err = ip6_dst_lookup_tail(sock_net(sk), sk, &dst, fl6);
1056 if (err)
1057 return ERR_PTR(err);
1058 if (final_dst)
1059 fl6->daddr = *final_dst;
1060
1061 return xfrm_lookup_route(sock_net(sk), dst, flowi6_to_flowi(fl6), sk, 0);
1062 }
1063 EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup_flow);
1064
1065 static inline int ip6_ufo_append_data(struct sock *sk,
1066 struct sk_buff_head *queue,
1067 int getfrag(void *from, char *to, int offset, int len,
1068 int odd, struct sk_buff *skb),
1069 void *from, int length, int hh_len, int fragheaderlen,
1070 int transhdrlen, int mtu, unsigned int flags,
1071 const struct flowi6 *fl6)
1072
1073 {
1074 struct sk_buff *skb;
1075 int err;
1076
1077 /* There is support for UDP large send offload by network
1078 * device, so create one single skb packet containing complete
1079 * udp datagram
1080 */
1081 skb = skb_peek_tail(queue);
1082 if (!skb) {
1083 skb = sock_alloc_send_skb(sk,
1084 hh_len + fragheaderlen + transhdrlen + 20,
1085 (flags & MSG_DONTWAIT), &err);
1086 if (!skb)
1087 return err;
1088
1089 /* reserve space for Hardware header */
1090 skb_reserve(skb, hh_len);
1091
1092 /* create space for UDP/IP header */
1093 skb_put(skb, fragheaderlen + transhdrlen);
1094
1095 /* initialize network header pointer */
1096 skb_reset_network_header(skb);
1097
1098 /* initialize protocol header pointer */
1099 skb->transport_header = skb->network_header + fragheaderlen;
1100
1101 skb->protocol = htons(ETH_P_IPV6);
1102 skb->csum = 0;
1103
1104 __skb_queue_tail(queue, skb);
1105 } else if (skb_is_gso(skb)) {
1106 goto append;
1107 }
1108
1109 skb->ip_summed = CHECKSUM_PARTIAL;
1110 /* Specify the length of each IPv6 datagram fragment.
1111 * It has to be a multiple of 8.
1112 */
1113 skb_shinfo(skb)->gso_size = (mtu - fragheaderlen -
1114 sizeof(struct frag_hdr)) & ~7;
1115 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
1116 skb_shinfo(skb)->ip6_frag_id = ipv6_select_ident(sock_net(sk),
1117 &fl6->daddr,
1118 &fl6->saddr);
1119
1120 append:
1121 return skb_append_datato_frags(sk, skb, getfrag, from,
1122 (length - transhdrlen));
1123 }
1124
1125 static inline struct ipv6_opt_hdr *ip6_opt_dup(struct ipv6_opt_hdr *src,
1126 gfp_t gfp)
1127 {
1128 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL;
1129 }
1130
1131 static inline struct ipv6_rt_hdr *ip6_rthdr_dup(struct ipv6_rt_hdr *src,
1132 gfp_t gfp)
1133 {
1134 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL;
1135 }
1136
1137 static void ip6_append_data_mtu(unsigned int *mtu,
1138 int *maxfraglen,
1139 unsigned int fragheaderlen,
1140 struct sk_buff *skb,
1141 struct rt6_info *rt,
1142 unsigned int orig_mtu)
1143 {
1144 if (!(rt->dst.flags & DST_XFRM_TUNNEL)) {
1145 if (!skb) {
1146 /* first fragment, reserve header_len */
1147 *mtu = orig_mtu - rt->dst.header_len;
1148
1149 } else {
1150 /*
1151 * this fragment is not first, the headers
1152 * space is regarded as data space.
1153 */
1154 *mtu = orig_mtu;
1155 }
1156 *maxfraglen = ((*mtu - fragheaderlen) & ~7)
1157 + fragheaderlen - sizeof(struct frag_hdr);
1158 }
1159 }
1160
1161 static int ip6_setup_cork(struct sock *sk, struct inet_cork_full *cork,
1162 struct inet6_cork *v6_cork,
1163 int hlimit, int tclass, struct ipv6_txoptions *opt,
1164 struct rt6_info *rt, struct flowi6 *fl6)
1165 {
1166 struct ipv6_pinfo *np = inet6_sk(sk);
1167 unsigned int mtu;
1168
1169 /*
1170 * setup for corking
1171 */
1172 if (opt) {
1173 if (WARN_ON(v6_cork->opt))
1174 return -EINVAL;
1175
1176 v6_cork->opt = kzalloc(opt->tot_len, sk->sk_allocation);
1177 if (unlikely(!v6_cork->opt))
1178 return -ENOBUFS;
1179
1180 v6_cork->opt->tot_len = opt->tot_len;
1181 v6_cork->opt->opt_flen = opt->opt_flen;
1182 v6_cork->opt->opt_nflen = opt->opt_nflen;
1183
1184 v6_cork->opt->dst0opt = ip6_opt_dup(opt->dst0opt,
1185 sk->sk_allocation);
1186 if (opt->dst0opt && !v6_cork->opt->dst0opt)
1187 return -ENOBUFS;
1188
1189 v6_cork->opt->dst1opt = ip6_opt_dup(opt->dst1opt,
1190 sk->sk_allocation);
1191 if (opt->dst1opt && !v6_cork->opt->dst1opt)
1192 return -ENOBUFS;
1193
1194 v6_cork->opt->hopopt = ip6_opt_dup(opt->hopopt,
1195 sk->sk_allocation);
1196 if (opt->hopopt && !v6_cork->opt->hopopt)
1197 return -ENOBUFS;
1198
1199 v6_cork->opt->srcrt = ip6_rthdr_dup(opt->srcrt,
1200 sk->sk_allocation);
1201 if (opt->srcrt && !v6_cork->opt->srcrt)
1202 return -ENOBUFS;
1203
1204 /* need source address above miyazawa*/
1205 }
1206 dst_hold(&rt->dst);
1207 cork->base.dst = &rt->dst;
1208 cork->fl.u.ip6 = *fl6;
1209 v6_cork->hop_limit = hlimit;
1210 v6_cork->tclass = tclass;
1211 if (rt->dst.flags & DST_XFRM_TUNNEL)
1212 mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ?
1213 rt->dst.dev->mtu : dst_mtu(&rt->dst);
1214 else
1215 mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ?
1216 rt->dst.dev->mtu : dst_mtu(rt->dst.path);
1217 if (np->frag_size < mtu) {
1218 if (np->frag_size)
1219 mtu = np->frag_size;
1220 }
1221 cork->base.fragsize = mtu;
1222 if (dst_allfrag(rt->dst.path))
1223 cork->base.flags |= IPCORK_ALLFRAG;
1224 cork->base.length = 0;
1225
1226 return 0;
1227 }
1228
1229 static int __ip6_append_data(struct sock *sk,
1230 struct flowi6 *fl6,
1231 struct sk_buff_head *queue,
1232 struct inet_cork *cork,
1233 struct inet6_cork *v6_cork,
1234 struct page_frag *pfrag,
1235 int getfrag(void *from, char *to, int offset,
1236 int len, int odd, struct sk_buff *skb),
1237 void *from, int length, int transhdrlen,
1238 unsigned int flags, int dontfrag)
1239 {
1240 struct sk_buff *skb, *skb_prev = NULL;
1241 unsigned int maxfraglen, fragheaderlen, mtu, orig_mtu;
1242 int exthdrlen = 0;
1243 int dst_exthdrlen = 0;
1244 int hh_len;
1245 int copy;
1246 int err;
1247 int offset = 0;
1248 __u8 tx_flags = 0;
1249 u32 tskey = 0;
1250 struct rt6_info *rt = (struct rt6_info *)cork->dst;
1251 struct ipv6_txoptions *opt = v6_cork->opt;
1252 int csummode = CHECKSUM_NONE;
1253
1254 skb = skb_peek_tail(queue);
1255 if (!skb) {
1256 exthdrlen = opt ? opt->opt_flen : 0;
1257 dst_exthdrlen = rt->dst.header_len - rt->rt6i_nfheader_len;
1258 }
1259
1260 mtu = cork->fragsize;
1261 orig_mtu = mtu;
1262
1263 hh_len = LL_RESERVED_SPACE(rt->dst.dev);
1264
1265 fragheaderlen = sizeof(struct ipv6hdr) + rt->rt6i_nfheader_len +
1266 (opt ? opt->opt_nflen : 0);
1267 maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen -
1268 sizeof(struct frag_hdr);
1269
1270 if (mtu <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN) {
1271 unsigned int maxnonfragsize, headersize;
1272
1273 headersize = sizeof(struct ipv6hdr) +
1274 (opt ? opt->opt_flen + opt->opt_nflen : 0) +
1275 (dst_allfrag(&rt->dst) ?
1276 sizeof(struct frag_hdr) : 0) +
1277 rt->rt6i_nfheader_len;
1278
1279 if (ip6_sk_ignore_df(sk))
1280 maxnonfragsize = sizeof(struct ipv6hdr) + IPV6_MAXPLEN;
1281 else
1282 maxnonfragsize = mtu;
1283
1284 /* dontfrag active */
1285 if ((cork->length + length > mtu - headersize) && dontfrag &&
1286 (sk->sk_protocol == IPPROTO_UDP ||
1287 sk->sk_protocol == IPPROTO_RAW)) {
1288 ipv6_local_rxpmtu(sk, fl6, mtu - headersize +
1289 sizeof(struct ipv6hdr));
1290 goto emsgsize;
1291 }
1292
1293 if (cork->length + length > maxnonfragsize - headersize) {
1294 emsgsize:
1295 ipv6_local_error(sk, EMSGSIZE, fl6,
1296 mtu - headersize +
1297 sizeof(struct ipv6hdr));
1298 return -EMSGSIZE;
1299 }
1300 }
1301
1302 if (sk->sk_type == SOCK_DGRAM || sk->sk_type == SOCK_RAW) {
1303 sock_tx_timestamp(sk, &tx_flags);
1304 if (tx_flags & SKBTX_ANY_SW_TSTAMP &&
1305 sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)
1306 tskey = sk->sk_tskey++;
1307 }
1308
1309 /* If this is the first and only packet and device
1310 * supports checksum offloading, let's use it.
1311 * Use transhdrlen, same as IPv4, because partial
1312 * sums only work when transhdrlen is set.
1313 */
1314 if (transhdrlen && sk->sk_protocol == IPPROTO_UDP &&
1315 length + fragheaderlen < mtu &&
1316 rt->dst.dev->features & NETIF_F_V6_CSUM &&
1317 !exthdrlen)
1318 csummode = CHECKSUM_PARTIAL;
1319 /*
1320 * Let's try using as much space as possible.
1321 * Use MTU if total length of the message fits into the MTU.
1322 * Otherwise, we need to reserve fragment header and
1323 * fragment alignment (= 8-15 octects, in total).
1324 *
1325 * Note that we may need to "move" the data from the tail of
1326 * of the buffer to the new fragment when we split
1327 * the message.
1328 *
1329 * FIXME: It may be fragmented into multiple chunks
1330 * at once if non-fragmentable extension headers
1331 * are too large.
1332 * --yoshfuji
1333 */
1334
1335 cork->length += length;
1336 if (((length > mtu) ||
1337 (skb && skb_is_gso(skb))) &&
1338 (sk->sk_protocol == IPPROTO_UDP) &&
1339 (rt->dst.dev->features & NETIF_F_UFO) &&
1340 (sk->sk_type == SOCK_DGRAM)) {
1341 err = ip6_ufo_append_data(sk, queue, getfrag, from, length,
1342 hh_len, fragheaderlen,
1343 transhdrlen, mtu, flags, fl6);
1344 if (err)
1345 goto error;
1346 return 0;
1347 }
1348
1349 if (!skb)
1350 goto alloc_new_skb;
1351
1352 while (length > 0) {
1353 /* Check if the remaining data fits into current packet. */
1354 copy = (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len;
1355 if (copy < length)
1356 copy = maxfraglen - skb->len;
1357
1358 if (copy <= 0) {
1359 char *data;
1360 unsigned int datalen;
1361 unsigned int fraglen;
1362 unsigned int fraggap;
1363 unsigned int alloclen;
1364 alloc_new_skb:
1365 /* There's no room in the current skb */
1366 if (skb)
1367 fraggap = skb->len - maxfraglen;
1368 else
1369 fraggap = 0;
1370 /* update mtu and maxfraglen if necessary */
1371 if (!skb || !skb_prev)
1372 ip6_append_data_mtu(&mtu, &maxfraglen,
1373 fragheaderlen, skb, rt,
1374 orig_mtu);
1375
1376 skb_prev = skb;
1377
1378 /*
1379 * If remaining data exceeds the mtu,
1380 * we know we need more fragment(s).
1381 */
1382 datalen = length + fraggap;
1383
1384 if (datalen > (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen)
1385 datalen = maxfraglen - fragheaderlen - rt->dst.trailer_len;
1386 if ((flags & MSG_MORE) &&
1387 !(rt->dst.dev->features&NETIF_F_SG))
1388 alloclen = mtu;
1389 else
1390 alloclen = datalen + fragheaderlen;
1391
1392 alloclen += dst_exthdrlen;
1393
1394 if (datalen != length + fraggap) {
1395 /*
1396 * this is not the last fragment, the trailer
1397 * space is regarded as data space.
1398 */
1399 datalen += rt->dst.trailer_len;
1400 }
1401
1402 alloclen += rt->dst.trailer_len;
1403 fraglen = datalen + fragheaderlen;
1404
1405 /*
1406 * We just reserve space for fragment header.
1407 * Note: this may be overallocation if the message
1408 * (without MSG_MORE) fits into the MTU.
1409 */
1410 alloclen += sizeof(struct frag_hdr);
1411
1412 if (transhdrlen) {
1413 skb = sock_alloc_send_skb(sk,
1414 alloclen + hh_len,
1415 (flags & MSG_DONTWAIT), &err);
1416 } else {
1417 skb = NULL;
1418 if (atomic_read(&sk->sk_wmem_alloc) <=
1419 2 * sk->sk_sndbuf)
1420 skb = sock_wmalloc(sk,
1421 alloclen + hh_len, 1,
1422 sk->sk_allocation);
1423 if (unlikely(!skb))
1424 err = -ENOBUFS;
1425 }
1426 if (!skb)
1427 goto error;
1428 /*
1429 * Fill in the control structures
1430 */
1431 skb->protocol = htons(ETH_P_IPV6);
1432 skb->ip_summed = csummode;
1433 skb->csum = 0;
1434 /* reserve for fragmentation and ipsec header */
1435 skb_reserve(skb, hh_len + sizeof(struct frag_hdr) +
1436 dst_exthdrlen);
1437
1438 /* Only the initial fragment is time stamped */
1439 skb_shinfo(skb)->tx_flags = tx_flags;
1440 tx_flags = 0;
1441 skb_shinfo(skb)->tskey = tskey;
1442 tskey = 0;
1443
1444 /*
1445 * Find where to start putting bytes
1446 */
1447 data = skb_put(skb, fraglen);
1448 skb_set_network_header(skb, exthdrlen);
1449 data += fragheaderlen;
1450 skb->transport_header = (skb->network_header +
1451 fragheaderlen);
1452 if (fraggap) {
1453 skb->csum = skb_copy_and_csum_bits(
1454 skb_prev, maxfraglen,
1455 data + transhdrlen, fraggap, 0);
1456 skb_prev->csum = csum_sub(skb_prev->csum,
1457 skb->csum);
1458 data += fraggap;
1459 pskb_trim_unique(skb_prev, maxfraglen);
1460 }
1461 copy = datalen - transhdrlen - fraggap;
1462
1463 if (copy < 0) {
1464 err = -EINVAL;
1465 kfree_skb(skb);
1466 goto error;
1467 } else if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) {
1468 err = -EFAULT;
1469 kfree_skb(skb);
1470 goto error;
1471 }
1472
1473 offset += copy;
1474 length -= datalen - fraggap;
1475 transhdrlen = 0;
1476 exthdrlen = 0;
1477 dst_exthdrlen = 0;
1478
1479 /*
1480 * Put the packet on the pending queue
1481 */
1482 __skb_queue_tail(queue, skb);
1483 continue;
1484 }
1485
1486 if (copy > length)
1487 copy = length;
1488
1489 if (!(rt->dst.dev->features&NETIF_F_SG)) {
1490 unsigned int off;
1491
1492 off = skb->len;
1493 if (getfrag(from, skb_put(skb, copy),
1494 offset, copy, off, skb) < 0) {
1495 __skb_trim(skb, off);
1496 err = -EFAULT;
1497 goto error;
1498 }
1499 } else {
1500 int i = skb_shinfo(skb)->nr_frags;
1501
1502 err = -ENOMEM;
1503 if (!sk_page_frag_refill(sk, pfrag))
1504 goto error;
1505
1506 if (!skb_can_coalesce(skb, i, pfrag->page,
1507 pfrag->offset)) {
1508 err = -EMSGSIZE;
1509 if (i == MAX_SKB_FRAGS)
1510 goto error;
1511
1512 __skb_fill_page_desc(skb, i, pfrag->page,
1513 pfrag->offset, 0);
1514 skb_shinfo(skb)->nr_frags = ++i;
1515 get_page(pfrag->page);
1516 }
1517 copy = min_t(int, copy, pfrag->size - pfrag->offset);
1518 if (getfrag(from,
1519 page_address(pfrag->page) + pfrag->offset,
1520 offset, copy, skb->len, skb) < 0)
1521 goto error_efault;
1522
1523 pfrag->offset += copy;
1524 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
1525 skb->len += copy;
1526 skb->data_len += copy;
1527 skb->truesize += copy;
1528 atomic_add(copy, &sk->sk_wmem_alloc);
1529 }
1530 offset += copy;
1531 length -= copy;
1532 }
1533
1534 return 0;
1535
1536 error_efault:
1537 err = -EFAULT;
1538 error:
1539 cork->length -= length;
1540 IP6_INC_STATS(sock_net(sk), rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS);
1541 return err;
1542 }
1543
1544 int ip6_append_data(struct sock *sk,
1545 int getfrag(void *from, char *to, int offset, int len,
1546 int odd, struct sk_buff *skb),
1547 void *from, int length, int transhdrlen, int hlimit,
1548 int tclass, struct ipv6_txoptions *opt, struct flowi6 *fl6,
1549 struct rt6_info *rt, unsigned int flags, int dontfrag)
1550 {
1551 struct inet_sock *inet = inet_sk(sk);
1552 struct ipv6_pinfo *np = inet6_sk(sk);
1553 int exthdrlen;
1554 int err;
1555
1556 if (flags&MSG_PROBE)
1557 return 0;
1558 if (skb_queue_empty(&sk->sk_write_queue)) {
1559 /*
1560 * setup for corking
1561 */
1562 err = ip6_setup_cork(sk, &inet->cork, &np->cork, hlimit,
1563 tclass, opt, rt, fl6);
1564 if (err)
1565 return err;
1566
1567 exthdrlen = (opt ? opt->opt_flen : 0);
1568 length += exthdrlen;
1569 transhdrlen += exthdrlen;
1570 } else {
1571 fl6 = &inet->cork.fl.u.ip6;
1572 transhdrlen = 0;
1573 }
1574
1575 return __ip6_append_data(sk, fl6, &sk->sk_write_queue, &inet->cork.base,
1576 &np->cork, sk_page_frag(sk), getfrag,
1577 from, length, transhdrlen, flags, dontfrag);
1578 }
1579 EXPORT_SYMBOL_GPL(ip6_append_data);
1580
1581 static void ip6_cork_release(struct inet_cork_full *cork,
1582 struct inet6_cork *v6_cork)
1583 {
1584 if (v6_cork->opt) {
1585 kfree(v6_cork->opt->dst0opt);
1586 kfree(v6_cork->opt->dst1opt);
1587 kfree(v6_cork->opt->hopopt);
1588 kfree(v6_cork->opt->srcrt);
1589 kfree(v6_cork->opt);
1590 v6_cork->opt = NULL;
1591 }
1592
1593 if (cork->base.dst) {
1594 dst_release(cork->base.dst);
1595 cork->base.dst = NULL;
1596 cork->base.flags &= ~IPCORK_ALLFRAG;
1597 }
1598 memset(&cork->fl, 0, sizeof(cork->fl));
1599 }
1600
1601 struct sk_buff *__ip6_make_skb(struct sock *sk,
1602 struct sk_buff_head *queue,
1603 struct inet_cork_full *cork,
1604 struct inet6_cork *v6_cork)
1605 {
1606 struct sk_buff *skb, *tmp_skb;
1607 struct sk_buff **tail_skb;
1608 struct in6_addr final_dst_buf, *final_dst = &final_dst_buf;
1609 struct ipv6_pinfo *np = inet6_sk(sk);
1610 struct net *net = sock_net(sk);
1611 struct ipv6hdr *hdr;
1612 struct ipv6_txoptions *opt = v6_cork->opt;
1613 struct rt6_info *rt = (struct rt6_info *)cork->base.dst;
1614 struct flowi6 *fl6 = &cork->fl.u.ip6;
1615 unsigned char proto = fl6->flowi6_proto;
1616
1617 skb = __skb_dequeue(queue);
1618 if (!skb)
1619 goto out;
1620 tail_skb = &(skb_shinfo(skb)->frag_list);
1621
1622 /* move skb->data to ip header from ext header */
1623 if (skb->data < skb_network_header(skb))
1624 __skb_pull(skb, skb_network_offset(skb));
1625 while ((tmp_skb = __skb_dequeue(queue)) != NULL) {
1626 __skb_pull(tmp_skb, skb_network_header_len(skb));
1627 *tail_skb = tmp_skb;
1628 tail_skb = &(tmp_skb->next);
1629 skb->len += tmp_skb->len;
1630 skb->data_len += tmp_skb->len;
1631 skb->truesize += tmp_skb->truesize;
1632 tmp_skb->destructor = NULL;
1633 tmp_skb->sk = NULL;
1634 }
1635
1636 /* Allow local fragmentation. */
1637 skb->ignore_df = ip6_sk_ignore_df(sk);
1638
1639 *final_dst = fl6->daddr;
1640 __skb_pull(skb, skb_network_header_len(skb));
1641 if (opt && opt->opt_flen)
1642 ipv6_push_frag_opts(skb, opt, &proto);
1643 if (opt && opt->opt_nflen)
1644 ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst);
1645
1646 skb_push(skb, sizeof(struct ipv6hdr));
1647 skb_reset_network_header(skb);
1648 hdr = ipv6_hdr(skb);
1649
1650 ip6_flow_hdr(hdr, v6_cork->tclass,
1651 ip6_make_flowlabel(net, skb, fl6->flowlabel,
1652 np->autoflowlabel, fl6));
1653 hdr->hop_limit = v6_cork->hop_limit;
1654 hdr->nexthdr = proto;
1655 hdr->saddr = fl6->saddr;
1656 hdr->daddr = *final_dst;
1657
1658 skb->priority = sk->sk_priority;
1659 skb->mark = sk->sk_mark;
1660
1661 skb_dst_set(skb, dst_clone(&rt->dst));
1662 IP6_UPD_PO_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUT, skb->len);
1663 if (proto == IPPROTO_ICMPV6) {
1664 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
1665
1666 ICMP6MSGOUT_INC_STATS(net, idev, icmp6_hdr(skb)->icmp6_type);
1667 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
1668 }
1669
1670 ip6_cork_release(cork, v6_cork);
1671 out:
1672 return skb;
1673 }
1674
1675 int ip6_send_skb(struct sk_buff *skb)
1676 {
1677 struct net *net = sock_net(skb->sk);
1678 struct rt6_info *rt = (struct rt6_info *)skb_dst(skb);
1679 int err;
1680
1681 err = ip6_local_out(skb);
1682 if (err) {
1683 if (err > 0)
1684 err = net_xmit_errno(err);
1685 if (err)
1686 IP6_INC_STATS(net, rt->rt6i_idev,
1687 IPSTATS_MIB_OUTDISCARDS);
1688 }
1689
1690 return err;
1691 }
1692
1693 int ip6_push_pending_frames(struct sock *sk)
1694 {
1695 struct sk_buff *skb;
1696
1697 skb = ip6_finish_skb(sk);
1698 if (!skb)
1699 return 0;
1700
1701 return ip6_send_skb(skb);
1702 }
1703 EXPORT_SYMBOL_GPL(ip6_push_pending_frames);
1704
1705 static void __ip6_flush_pending_frames(struct sock *sk,
1706 struct sk_buff_head *queue,
1707 struct inet_cork_full *cork,
1708 struct inet6_cork *v6_cork)
1709 {
1710 struct sk_buff *skb;
1711
1712 while ((skb = __skb_dequeue_tail(queue)) != NULL) {
1713 if (skb_dst(skb))
1714 IP6_INC_STATS(sock_net(sk), ip6_dst_idev(skb_dst(skb)),
1715 IPSTATS_MIB_OUTDISCARDS);
1716 kfree_skb(skb);
1717 }
1718
1719 ip6_cork_release(cork, v6_cork);
1720 }
1721
1722 void ip6_flush_pending_frames(struct sock *sk)
1723 {
1724 __ip6_flush_pending_frames(sk, &sk->sk_write_queue,
1725 &inet_sk(sk)->cork, &inet6_sk(sk)->cork);
1726 }
1727 EXPORT_SYMBOL_GPL(ip6_flush_pending_frames);
1728
1729 struct sk_buff *ip6_make_skb(struct sock *sk,
1730 int getfrag(void *from, char *to, int offset,
1731 int len, int odd, struct sk_buff *skb),
1732 void *from, int length, int transhdrlen,
1733 int hlimit, int tclass,
1734 struct ipv6_txoptions *opt, struct flowi6 *fl6,
1735 struct rt6_info *rt, unsigned int flags,
1736 int dontfrag)
1737 {
1738 struct inet_cork_full cork;
1739 struct inet6_cork v6_cork;
1740 struct sk_buff_head queue;
1741 int exthdrlen = (opt ? opt->opt_flen : 0);
1742 int err;
1743
1744 if (flags & MSG_PROBE)
1745 return NULL;
1746
1747 __skb_queue_head_init(&queue);
1748
1749 cork.base.flags = 0;
1750 cork.base.addr = 0;
1751 cork.base.opt = NULL;
1752 v6_cork.opt = NULL;
1753 err = ip6_setup_cork(sk, &cork, &v6_cork, hlimit, tclass, opt, rt, fl6);
1754 if (err)
1755 return ERR_PTR(err);
1756
1757 if (dontfrag < 0)
1758 dontfrag = inet6_sk(sk)->dontfrag;
1759
1760 err = __ip6_append_data(sk, fl6, &queue, &cork.base, &v6_cork,
1761 &current->task_frag, getfrag, from,
1762 length + exthdrlen, transhdrlen + exthdrlen,
1763 flags, dontfrag);
1764 if (err) {
1765 __ip6_flush_pending_frames(sk, &queue, &cork, &v6_cork);
1766 return ERR_PTR(err);
1767 }
1768
1769 return __ip6_make_skb(sk, &queue, &cork, &v6_cork);
1770 }
Linux kernel - Deliverables
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