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Linux 4.8.3
[linux/fpc-iii.git] / net / ipv6 / ip6_output.c
blob1dfc402d9ad1ebbf70aa8af6c613bff7fd632c66
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 #include <net/l3mdev.h>
59
60 static int ip6_finish_output2(struct net *net, struct sock *sk, struct sk_buff *skb)
61 {
62 struct dst_entry *dst = skb_dst(skb);
63 struct net_device *dev = dst->dev;
64 struct neighbour *neigh;
65 struct in6_addr *nexthop;
66 int ret;
67
68 skb->protocol = htons(ETH_P_IPV6);
69 skb->dev = dev;
70
71 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) {
72 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
73
74 if (!(dev->flags & IFF_LOOPBACK) && sk_mc_loop(sk) &&
75 ((mroute6_socket(net, skb) &&
76 !(IP6CB(skb)->flags & IP6SKB_FORWARDED)) ||
77 ipv6_chk_mcast_addr(dev, &ipv6_hdr(skb)->daddr,
78 &ipv6_hdr(skb)->saddr))) {
79 struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC);
80
81 /* Do not check for IFF_ALLMULTI; multicast routing
82 is not supported in any case.
83 */
84 if (newskb)
85 NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING,
86 net, sk, newskb, NULL, newskb->dev,
87 dev_loopback_xmit);
88
89 if (ipv6_hdr(skb)->hop_limit == 0) {
90 IP6_INC_STATS(net, idev,
91 IPSTATS_MIB_OUTDISCARDS);
92 kfree_skb(skb);
93 return 0;
94 }
95 }
96
97 IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUTMCAST, 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(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
120 kfree_skb(skb);
121 return -EINVAL;
122 }
123
124 static int ip6_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb)
125 {
126 if ((skb->len > ip6_skb_dst_mtu(skb) && !skb_is_gso(skb)) ||
127 dst_allfrag(skb_dst(skb)) ||
128 (IP6CB(skb)->frag_max_size && skb->len > IP6CB(skb)->frag_max_size))
129 return ip6_fragment(net, sk, skb, ip6_finish_output2);
130 else
131 return ip6_finish_output2(net, sk, skb);
132 }
133
134 int ip6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
135 {
136 struct net_device *dev = skb_dst(skb)->dev;
137 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
138
139 if (unlikely(idev->cnf.disable_ipv6)) {
140 IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTDISCARDS);
141 kfree_skb(skb);
142 return 0;
143 }
144
145 return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING,
146 net, sk, skb, NULL, dev,
147 ip6_finish_output,
148 !(IP6CB(skb)->flags & IP6SKB_REROUTED));
149 }
150
151 /*
152 * xmit an sk_buff (used by TCP, SCTP and DCCP)
153 * Note : socket lock is not held for SYNACK packets, but might be modified
154 * by calls to skb_set_owner_w() and ipv6_local_error(),
155 * which are using proper atomic operations or spinlocks.
156 */
157 int ip6_xmit(const struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
158 struct ipv6_txoptions *opt, int tclass)
159 {
160 struct net *net = sock_net(sk);
161 const struct ipv6_pinfo *np = inet6_sk(sk);
162 struct in6_addr *first_hop = &fl6->daddr;
163 struct dst_entry *dst = skb_dst(skb);
164 struct ipv6hdr *hdr;
165 u8 proto = fl6->flowi6_proto;
166 int seg_len = skb->len;
167 int hlimit = -1;
168 u32 mtu;
169
170 if (opt) {
171 unsigned int head_room;
172
173 /* First: exthdrs may take lots of space (~8K for now)
174 MAX_HEADER is not enough.
175 */
176 head_room = opt->opt_nflen + opt->opt_flen;
177 seg_len += head_room;
178 head_room += sizeof(struct ipv6hdr) + LL_RESERVED_SPACE(dst->dev);
179
180 if (skb_headroom(skb) < head_room) {
181 struct sk_buff *skb2 = skb_realloc_headroom(skb, head_room);
182 if (!skb2) {
183 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
184 IPSTATS_MIB_OUTDISCARDS);
185 kfree_skb(skb);
186 return -ENOBUFS;
187 }
188 consume_skb(skb);
189 skb = skb2;
190 /* skb_set_owner_w() changes sk->sk_wmem_alloc atomically,
191 * it is safe to call in our context (socket lock not held)
192 */
193 skb_set_owner_w(skb, (struct sock *)sk);
194 }
195 if (opt->opt_flen)
196 ipv6_push_frag_opts(skb, opt, &proto);
197 if (opt->opt_nflen)
198 ipv6_push_nfrag_opts(skb, opt, &proto, &first_hop);
199 }
200
201 skb_push(skb, sizeof(struct ipv6hdr));
202 skb_reset_network_header(skb);
203 hdr = ipv6_hdr(skb);
204
205 /*
206 * Fill in the IPv6 header
207 */
208 if (np)
209 hlimit = np->hop_limit;
210 if (hlimit < 0)
211 hlimit = ip6_dst_hoplimit(dst);
212
213 ip6_flow_hdr(hdr, tclass, ip6_make_flowlabel(net, skb, fl6->flowlabel,
214 np->autoflowlabel, fl6));
215
216 hdr->payload_len = htons(seg_len);
217 hdr->nexthdr = proto;
218 hdr->hop_limit = hlimit;
219
220 hdr->saddr = fl6->saddr;
221 hdr->daddr = *first_hop;
222
223 skb->protocol = htons(ETH_P_IPV6);
224 skb->priority = sk->sk_priority;
225 skb->mark = sk->sk_mark;
226
227 mtu = dst_mtu(dst);
228 if ((skb->len <= mtu) || skb->ignore_df || skb_is_gso(skb)) {
229 IP6_UPD_PO_STATS(net, ip6_dst_idev(skb_dst(skb)),
230 IPSTATS_MIB_OUT, skb->len);
231 /* hooks should never assume socket lock is held.
232 * we promote our socket to non const
233 */
234 return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
235 net, (struct sock *)sk, skb, NULL, dst->dev,
236 dst_output);
237 }
238
239 skb->dev = dst->dev;
240 /* ipv6_local_error() does not require socket lock,
241 * we promote our socket to non const
242 */
243 ipv6_local_error((struct sock *)sk, EMSGSIZE, fl6, mtu);
244
245 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_FRAGFAILS);
246 kfree_skb(skb);
247 return -EMSGSIZE;
248 }
249 EXPORT_SYMBOL(ip6_xmit);
250
251 static int ip6_call_ra_chain(struct sk_buff *skb, int sel)
252 {
253 struct ip6_ra_chain *ra;
254 struct sock *last = NULL;
255
256 read_lock(&ip6_ra_lock);
257 for (ra = ip6_ra_chain; ra; ra = ra->next) {
258 struct sock *sk = ra->sk;
259 if (sk && ra->sel == sel &&
260 (!sk->sk_bound_dev_if ||
261 sk->sk_bound_dev_if == skb->dev->ifindex)) {
262 if (last) {
263 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
264 if (skb2)
265 rawv6_rcv(last, skb2);
266 }
267 last = sk;
268 }
269 }
270
271 if (last) {
272 rawv6_rcv(last, skb);
273 read_unlock(&ip6_ra_lock);
274 return 1;
275 }
276 read_unlock(&ip6_ra_lock);
277 return 0;
278 }
279
280 static int ip6_forward_proxy_check(struct sk_buff *skb)
281 {
282 struct ipv6hdr *hdr = ipv6_hdr(skb);
283 u8 nexthdr = hdr->nexthdr;
284 __be16 frag_off;
285 int offset;
286
287 if (ipv6_ext_hdr(nexthdr)) {
288 offset = ipv6_skip_exthdr(skb, sizeof(*hdr), &nexthdr, &frag_off);
289 if (offset < 0)
290 return 0;
291 } else
292 offset = sizeof(struct ipv6hdr);
293
294 if (nexthdr == IPPROTO_ICMPV6) {
295 struct icmp6hdr *icmp6;
296
297 if (!pskb_may_pull(skb, (skb_network_header(skb) +
298 offset + 1 - skb->data)))
299 return 0;
300
301 icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset);
302
303 switch (icmp6->icmp6_type) {
304 case NDISC_ROUTER_SOLICITATION:
305 case NDISC_ROUTER_ADVERTISEMENT:
306 case NDISC_NEIGHBOUR_SOLICITATION:
307 case NDISC_NEIGHBOUR_ADVERTISEMENT:
308 case NDISC_REDIRECT:
309 /* For reaction involving unicast neighbor discovery
310 * message destined to the proxied address, pass it to
311 * input function.
312 */
313 return 1;
314 default:
315 break;
316 }
317 }
318
319 /*
320 * The proxying router can't forward traffic sent to a link-local
321 * address, so signal the sender and discard the packet. This
322 * behavior is clarified by the MIPv6 specification.
323 */
324 if (ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) {
325 dst_link_failure(skb);
326 return -1;
327 }
328
329 return 0;
330 }
331
332 static inline int ip6_forward_finish(struct net *net, struct sock *sk,
333 struct sk_buff *skb)
334 {
335 return dst_output(net, sk, skb);
336 }
337
338 static unsigned int ip6_dst_mtu_forward(const struct dst_entry *dst)
339 {
340 unsigned int mtu;
341 struct inet6_dev *idev;
342
343 if (dst_metric_locked(dst, RTAX_MTU)) {
344 mtu = dst_metric_raw(dst, RTAX_MTU);
345 if (mtu)
346 return mtu;
347 }
348
349 mtu = IPV6_MIN_MTU;
350 rcu_read_lock();
351 idev = __in6_dev_get(dst->dev);
352 if (idev)
353 mtu = idev->cnf.mtu6;
354 rcu_read_unlock();
355
356 return mtu;
357 }
358
359 static bool ip6_pkt_too_big(const struct sk_buff *skb, unsigned int mtu)
360 {
361 if (skb->len <= mtu)
362 return false;
363
364 /* ipv6 conntrack defrag sets max_frag_size + ignore_df */
365 if (IP6CB(skb)->frag_max_size && IP6CB(skb)->frag_max_size > mtu)
366 return true;
367
368 if (skb->ignore_df)
369 return false;
370
371 if (skb_is_gso(skb) && skb_gso_validate_mtu(skb, mtu))
372 return false;
373
374 return true;
375 }
376
377 int ip6_forward(struct sk_buff *skb)
378 {
379 struct dst_entry *dst = skb_dst(skb);
380 struct ipv6hdr *hdr = ipv6_hdr(skb);
381 struct inet6_skb_parm *opt = IP6CB(skb);
382 struct net *net = dev_net(dst->dev);
383 u32 mtu;
384
385 if (net->ipv6.devconf_all->forwarding == 0)
386 goto error;
387
388 if (skb->pkt_type != PACKET_HOST)
389 goto drop;
390
391 if (unlikely(skb->sk))
392 goto drop;
393
394 if (skb_warn_if_lro(skb))
395 goto drop;
396
397 if (!xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) {
398 __IP6_INC_STATS(net, ip6_dst_idev(dst),
399 IPSTATS_MIB_INDISCARDS);
400 goto drop;
401 }
402
403 skb_forward_csum(skb);
404
405 /*
406 * We DO NOT make any processing on
407 * RA packets, pushing them to user level AS IS
408 * without ane WARRANTY that application will be able
409 * to interpret them. The reason is that we
410 * cannot make anything clever here.
411 *
412 * We are not end-node, so that if packet contains
413 * AH/ESP, we cannot make anything.
414 * Defragmentation also would be mistake, RA packets
415 * cannot be fragmented, because there is no warranty
416 * that different fragments will go along one path. --ANK
417 */
418 if (unlikely(opt->flags & IP6SKB_ROUTERALERT)) {
419 if (ip6_call_ra_chain(skb, ntohs(opt->ra)))
420 return 0;
421 }
422
423 /*
424 * check and decrement ttl
425 */
426 if (hdr->hop_limit <= 1) {
427 /* Force OUTPUT device used as source address */
428 skb->dev = dst->dev;
429 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 0);
430 __IP6_INC_STATS(net, ip6_dst_idev(dst),
431 IPSTATS_MIB_INHDRERRORS);
432
433 kfree_skb(skb);
434 return -ETIMEDOUT;
435 }
436
437 /* XXX: idev->cnf.proxy_ndp? */
438 if (net->ipv6.devconf_all->proxy_ndp &&
439 pneigh_lookup(&nd_tbl, net, &hdr->daddr, skb->dev, 0)) {
440 int proxied = ip6_forward_proxy_check(skb);
441 if (proxied > 0)
442 return ip6_input(skb);
443 else if (proxied < 0) {
444 __IP6_INC_STATS(net, ip6_dst_idev(dst),
445 IPSTATS_MIB_INDISCARDS);
446 goto drop;
447 }
448 }
449
450 if (!xfrm6_route_forward(skb)) {
451 __IP6_INC_STATS(net, ip6_dst_idev(dst),
452 IPSTATS_MIB_INDISCARDS);
453 goto drop;
454 }
455 dst = skb_dst(skb);
456
457 /* IPv6 specs say nothing about it, but it is clear that we cannot
458 send redirects to source routed frames.
459 We don't send redirects to frames decapsulated from IPsec.
460 */
461 if (skb->dev == dst->dev && opt->srcrt == 0 && !skb_sec_path(skb)) {
462 struct in6_addr *target = NULL;
463 struct inet_peer *peer;
464 struct rt6_info *rt;
465
466 /*
467 * incoming and outgoing devices are the same
468 * send a redirect.
469 */
470
471 rt = (struct rt6_info *) dst;
472 if (rt->rt6i_flags & RTF_GATEWAY)
473 target = &rt->rt6i_gateway;
474 else
475 target = &hdr->daddr;
476
477 peer = inet_getpeer_v6(net->ipv6.peers, &hdr->daddr, 1);
478
479 /* Limit redirects both by destination (here)
480 and by source (inside ndisc_send_redirect)
481 */
482 if (inet_peer_xrlim_allow(peer, 1*HZ))
483 ndisc_send_redirect(skb, target);
484 if (peer)
485 inet_putpeer(peer);
486 } else {
487 int addrtype = ipv6_addr_type(&hdr->saddr);
488
489 /* This check is security critical. */
490 if (addrtype == IPV6_ADDR_ANY ||
491 addrtype & (IPV6_ADDR_MULTICAST | IPV6_ADDR_LOOPBACK))
492 goto error;
493 if (addrtype & IPV6_ADDR_LINKLOCAL) {
494 icmpv6_send(skb, ICMPV6_DEST_UNREACH,
495 ICMPV6_NOT_NEIGHBOUR, 0);
496 goto error;
497 }
498 }
499
500 mtu = ip6_dst_mtu_forward(dst);
501 if (mtu < IPV6_MIN_MTU)
502 mtu = IPV6_MIN_MTU;
503
504 if (ip6_pkt_too_big(skb, mtu)) {
505 /* Again, force OUTPUT device used as source address */
506 skb->dev = dst->dev;
507 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
508 __IP6_INC_STATS(net, ip6_dst_idev(dst),
509 IPSTATS_MIB_INTOOBIGERRORS);
510 __IP6_INC_STATS(net, ip6_dst_idev(dst),
511 IPSTATS_MIB_FRAGFAILS);
512 kfree_skb(skb);
513 return -EMSGSIZE;
514 }
515
516 if (skb_cow(skb, dst->dev->hard_header_len)) {
517 __IP6_INC_STATS(net, ip6_dst_idev(dst),
518 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(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTFORWDATAGRAMS);
529 __IP6_ADD_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTOCTETS, skb->len);
530 return NF_HOOK(NFPROTO_IPV6, NF_INET_FORWARD,
531 net, NULL, skb, skb->dev, dst->dev,
532 ip6_forward_finish);
533
534 error:
535 __IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_INADDRERRORS);
536 drop:
537 kfree_skb(skb);
538 return -EINVAL;
539 }
540
541 static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from)
542 {
543 to->pkt_type = from->pkt_type;
544 to->priority = from->priority;
545 to->protocol = from->protocol;
546 skb_dst_drop(to);
547 skb_dst_set(to, dst_clone(skb_dst(from)));
548 to->dev = from->dev;
549 to->mark = from->mark;
550
551 #ifdef CONFIG_NET_SCHED
552 to->tc_index = from->tc_index;
553 #endif
554 nf_copy(to, from);
555 skb_copy_secmark(to, from);
556 }
557
558 int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
559 int (*output)(struct net *, struct sock *, struct sk_buff *))
560 {
561 struct sk_buff *frag;
562 struct rt6_info *rt = (struct rt6_info *)skb_dst(skb);
563 struct ipv6_pinfo *np = skb->sk && !dev_recursion_level() ?
564 inet6_sk(skb->sk) : NULL;
565 struct ipv6hdr *tmp_hdr;
566 struct frag_hdr *fh;
567 unsigned int mtu, hlen, left, len;
568 int hroom, troom;
569 __be32 frag_id;
570 int ptr, offset = 0, err = 0;
571 u8 *prevhdr, nexthdr = 0;
572
573 hlen = ip6_find_1stfragopt(skb, &prevhdr);
574 nexthdr = *prevhdr;
575
576 mtu = ip6_skb_dst_mtu(skb);
577
578 /* We must not fragment if the socket is set to force MTU discovery
579 * or if the skb it not generated by a local socket.
580 */
581 if (unlikely(!skb->ignore_df && skb->len > mtu))
582 goto fail_toobig;
583
584 if (IP6CB(skb)->frag_max_size) {
585 if (IP6CB(skb)->frag_max_size > mtu)
586 goto fail_toobig;
587
588 /* don't send fragments larger than what we received */
589 mtu = IP6CB(skb)->frag_max_size;
590 if (mtu < IPV6_MIN_MTU)
591 mtu = IPV6_MIN_MTU;
592 }
593
594 if (np && np->frag_size < mtu) {
595 if (np->frag_size)
596 mtu = np->frag_size;
597 }
598 if (mtu < hlen + sizeof(struct frag_hdr) + 8)
599 goto fail_toobig;
600 mtu -= hlen + sizeof(struct frag_hdr);
601
602 frag_id = ipv6_select_ident(net, &ipv6_hdr(skb)->daddr,
603 &ipv6_hdr(skb)->saddr);
604
605 if (skb->ip_summed == CHECKSUM_PARTIAL &&
606 (err = skb_checksum_help(skb)))
607 goto fail;
608
609 hroom = LL_RESERVED_SPACE(rt->dst.dev);
610 if (skb_has_frag_list(skb)) {
611 int first_len = skb_pagelen(skb);
612 struct sk_buff *frag2;
613
614 if (first_len - hlen > mtu ||
615 ((first_len - hlen) & 7) ||
616 skb_cloned(skb) ||
617 skb_headroom(skb) < (hroom + sizeof(struct frag_hdr)))
618 goto slow_path;
619
620 skb_walk_frags(skb, frag) {
621 /* Correct geometry. */
622 if (frag->len > mtu ||
623 ((frag->len & 7) && frag->next) ||
624 skb_headroom(frag) < (hlen + hroom + sizeof(struct frag_hdr)))
625 goto slow_path_clean;
626
627 /* Partially cloned skb? */
628 if (skb_shared(frag))
629 goto slow_path_clean;
630
631 BUG_ON(frag->sk);
632 if (skb->sk) {
633 frag->sk = skb->sk;
634 frag->destructor = sock_wfree;
635 }
636 skb->truesize -= frag->truesize;
637 }
638
639 err = 0;
640 offset = 0;
641 /* BUILD HEADER */
642
643 *prevhdr = NEXTHDR_FRAGMENT;
644 tmp_hdr = kmemdup(skb_network_header(skb), hlen, GFP_ATOMIC);
645 if (!tmp_hdr) {
646 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
647 IPSTATS_MIB_FRAGFAILS);
648 err = -ENOMEM;
649 goto fail;
650 }
651 frag = skb_shinfo(skb)->frag_list;
652 skb_frag_list_init(skb);
653
654 __skb_pull(skb, hlen);
655 fh = (struct frag_hdr *)__skb_push(skb, sizeof(struct frag_hdr));
656 __skb_push(skb, hlen);
657 skb_reset_network_header(skb);
658 memcpy(skb_network_header(skb), tmp_hdr, hlen);
659
660 fh->nexthdr = nexthdr;
661 fh->reserved = 0;
662 fh->frag_off = htons(IP6_MF);
663 fh->identification = frag_id;
664
665 first_len = skb_pagelen(skb);
666 skb->data_len = first_len - skb_headlen(skb);
667 skb->len = first_len;
668 ipv6_hdr(skb)->payload_len = htons(first_len -
669 sizeof(struct ipv6hdr));
670
671 dst_hold(&rt->dst);
672
673 for (;;) {
674 /* Prepare header of the next frame,
675 * before previous one went down. */
676 if (frag) {
677 frag->ip_summed = CHECKSUM_NONE;
678 skb_reset_transport_header(frag);
679 fh = (struct frag_hdr *)__skb_push(frag, sizeof(struct frag_hdr));
680 __skb_push(frag, hlen);
681 skb_reset_network_header(frag);
682 memcpy(skb_network_header(frag), tmp_hdr,
683 hlen);
684 offset += skb->len - hlen - sizeof(struct frag_hdr);
685 fh->nexthdr = nexthdr;
686 fh->reserved = 0;
687 fh->frag_off = htons(offset);
688 if (frag->next)
689 fh->frag_off |= htons(IP6_MF);
690 fh->identification = frag_id;
691 ipv6_hdr(frag)->payload_len =
692 htons(frag->len -
693 sizeof(struct ipv6hdr));
694 ip6_copy_metadata(frag, skb);
695 }
696
697 err = output(net, sk, skb);
698 if (!err)
699 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
700 IPSTATS_MIB_FRAGCREATES);
701
702 if (err || !frag)
703 break;
704
705 skb = frag;
706 frag = skb->next;
707 skb->next = NULL;
708 }
709
710 kfree(tmp_hdr);
711
712 if (err == 0) {
713 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
714 IPSTATS_MIB_FRAGOKS);
715 ip6_rt_put(rt);
716 return 0;
717 }
718
719 kfree_skb_list(frag);
720
721 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
722 IPSTATS_MIB_FRAGFAILS);
723 ip6_rt_put(rt);
724 return err;
725
726 slow_path_clean:
727 skb_walk_frags(skb, frag2) {
728 if (frag2 == frag)
729 break;
730 frag2->sk = NULL;
731 frag2->destructor = NULL;
732 skb->truesize += frag2->truesize;
733 }
734 }
735
736 slow_path:
737 left = skb->len - hlen; /* Space per frame */
738 ptr = hlen; /* Where to start from */
739
740 /*
741 * Fragment the datagram.
742 */
743
744 *prevhdr = NEXTHDR_FRAGMENT;
745 troom = rt->dst.dev->needed_tailroom;
746
747 /*
748 * Keep copying data until we run out.
749 */
750 while (left > 0) {
751 len = left;
752 /* IF: it doesn't fit, use 'mtu' - the data space left */
753 if (len > mtu)
754 len = mtu;
755 /* IF: we are not sending up to and including the packet end
756 then align the next start on an eight byte boundary */
757 if (len < left) {
758 len &= ~7;
759 }
760
761 /* Allocate buffer */
762 frag = alloc_skb(len + hlen + sizeof(struct frag_hdr) +
763 hroom + troom, GFP_ATOMIC);
764 if (!frag) {
765 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
766 IPSTATS_MIB_FRAGFAILS);
767 err = -ENOMEM;
768 goto fail;
769 }
770
771 /*
772 * Set up data on packet
773 */
774
775 ip6_copy_metadata(frag, skb);
776 skb_reserve(frag, hroom);
777 skb_put(frag, len + hlen + sizeof(struct frag_hdr));
778 skb_reset_network_header(frag);
779 fh = (struct frag_hdr *)(skb_network_header(frag) + hlen);
780 frag->transport_header = (frag->network_header + hlen +
781 sizeof(struct frag_hdr));
782
783 /*
784 * Charge the memory for the fragment to any owner
785 * it might possess
786 */
787 if (skb->sk)
788 skb_set_owner_w(frag, skb->sk);
789
790 /*
791 * Copy the packet header into the new buffer.
792 */
793 skb_copy_from_linear_data(skb, skb_network_header(frag), hlen);
794
795 /*
796 * Build fragment header.
797 */
798 fh->nexthdr = nexthdr;
799 fh->reserved = 0;
800 fh->identification = frag_id;
801
802 /*
803 * Copy a block of the IP datagram.
804 */
805 BUG_ON(skb_copy_bits(skb, ptr, skb_transport_header(frag),
806 len));
807 left -= len;
808
809 fh->frag_off = htons(offset);
810 if (left > 0)
811 fh->frag_off |= htons(IP6_MF);
812 ipv6_hdr(frag)->payload_len = htons(frag->len -
813 sizeof(struct ipv6hdr));
814
815 ptr += len;
816 offset += len;
817
818 /*
819 * Put this fragment into the sending queue.
820 */
821 err = output(net, sk, frag);
822 if (err)
823 goto fail;
824
825 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
826 IPSTATS_MIB_FRAGCREATES);
827 }
828 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
829 IPSTATS_MIB_FRAGOKS);
830 consume_skb(skb);
831 return err;
832
833 fail_toobig:
834 if (skb->sk && dst_allfrag(skb_dst(skb)))
835 sk_nocaps_add(skb->sk, NETIF_F_GSO_MASK);
836
837 skb->dev = skb_dst(skb)->dev;
838 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
839 err = -EMSGSIZE;
840
841 fail:
842 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
843 IPSTATS_MIB_FRAGFAILS);
844 kfree_skb(skb);
845 return err;
846 }
847
848 static inline int ip6_rt_check(const struct rt6key *rt_key,
849 const struct in6_addr *fl_addr,
850 const struct in6_addr *addr_cache)
851 {
852 return (rt_key->plen != 128 || !ipv6_addr_equal(fl_addr, &rt_key->addr)) &&
853 (!addr_cache || !ipv6_addr_equal(fl_addr, addr_cache));
854 }
855
856 static struct dst_entry *ip6_sk_dst_check(struct sock *sk,
857 struct dst_entry *dst,
858 const struct flowi6 *fl6)
859 {
860 struct ipv6_pinfo *np = inet6_sk(sk);
861 struct rt6_info *rt;
862
863 if (!dst)
864 goto out;
865
866 if (dst->ops->family != AF_INET6) {
867 dst_release(dst);
868 return NULL;
869 }
870
871 rt = (struct rt6_info *)dst;
872 /* Yes, checking route validity in not connected
873 * case is not very simple. Take into account,
874 * that we do not support routing by source, TOS,
875 * and MSG_DONTROUTE --ANK (980726)
876 *
877 * 1. ip6_rt_check(): If route was host route,
878 * check that cached destination is current.
879 * If it is network route, we still may
880 * check its validity using saved pointer
881 * to the last used address: daddr_cache.
882 * We do not want to save whole address now,
883 * (because main consumer of this service
884 * is tcp, which has not this problem),
885 * so that the last trick works only on connected
886 * sockets.
887 * 2. oif also should be the same.
888 */
889 if (ip6_rt_check(&rt->rt6i_dst, &fl6->daddr, np->daddr_cache) ||
890 #ifdef CONFIG_IPV6_SUBTREES
891 ip6_rt_check(&rt->rt6i_src, &fl6->saddr, np->saddr_cache) ||
892 #endif
893 (!(fl6->flowi6_flags & FLOWI_FLAG_SKIP_NH_OIF) &&
894 (fl6->flowi6_oif && fl6->flowi6_oif != dst->dev->ifindex))) {
895 dst_release(dst);
896 dst = NULL;
897 }
898
899 out:
900 return dst;
901 }
902
903 static int ip6_dst_lookup_tail(struct net *net, const struct sock *sk,
904 struct dst_entry **dst, struct flowi6 *fl6)
905 {
906 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
907 struct neighbour *n;
908 struct rt6_info *rt;
909 #endif
910 int err;
911 int flags = 0;
912
913 if (ipv6_addr_any(&fl6->saddr) && fl6->flowi6_oif &&
914 (!*dst || !(*dst)->error)) {
915 err = l3mdev_get_saddr6(net, sk, fl6);
916 if (err)
917 goto out_err;
918 }
919
920 /* The correct way to handle this would be to do
921 * ip6_route_get_saddr, and then ip6_route_output; however,
922 * the route-specific preferred source forces the
923 * ip6_route_output call _before_ ip6_route_get_saddr.
924 *
925 * In source specific routing (no src=any default route),
926 * ip6_route_output will fail given src=any saddr, though, so
927 * that's why we try it again later.
928 */
929 if (ipv6_addr_any(&fl6->saddr) && (!*dst || !(*dst)->error)) {
930 struct rt6_info *rt;
931 bool had_dst = *dst != NULL;
932
933 if (!had_dst)
934 *dst = ip6_route_output(net, sk, fl6);
935 rt = (*dst)->error ? NULL : (struct rt6_info *)*dst;
936 err = ip6_route_get_saddr(net, rt, &fl6->daddr,
937 sk ? inet6_sk(sk)->srcprefs : 0,
938 &fl6->saddr);
939 if (err)
940 goto out_err_release;
941
942 /* If we had an erroneous initial result, pretend it
943 * never existed and let the SA-enabled version take
944 * over.
945 */
946 if (!had_dst && (*dst)->error) {
947 dst_release(*dst);
948 *dst = NULL;
949 }
950
951 if (fl6->flowi6_oif)
952 flags |= RT6_LOOKUP_F_IFACE;
953 }
954
955 if (!*dst)
956 *dst = ip6_route_output_flags(net, sk, fl6, flags);
957
958 err = (*dst)->error;
959 if (err)
960 goto out_err_release;
961
962 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
963 /*
964 * Here if the dst entry we've looked up
965 * has a neighbour entry that is in the INCOMPLETE
966 * state and the src address from the flow is
967 * marked as OPTIMISTIC, we release the found
968 * dst entry and replace it instead with the
969 * dst entry of the nexthop router
970 */
971 rt = (struct rt6_info *) *dst;
972 rcu_read_lock_bh();
973 n = __ipv6_neigh_lookup_noref(rt->dst.dev,
974 rt6_nexthop(rt, &fl6->daddr));
975 err = n && !(n->nud_state & NUD_VALID) ? -EINVAL : 0;
976 rcu_read_unlock_bh();
977
978 if (err) {
979 struct inet6_ifaddr *ifp;
980 struct flowi6 fl_gw6;
981 int redirect;
982
983 ifp = ipv6_get_ifaddr(net, &fl6->saddr,
984 (*dst)->dev, 1);
985
986 redirect = (ifp && ifp->flags & IFA_F_OPTIMISTIC);
987 if (ifp)
988 in6_ifa_put(ifp);
989
990 if (redirect) {
991 /*
992 * We need to get the dst entry for the
993 * default router instead
994 */
995 dst_release(*dst);
996 memcpy(&fl_gw6, fl6, sizeof(struct flowi6));
997 memset(&fl_gw6.daddr, 0, sizeof(struct in6_addr));
998 *dst = ip6_route_output(net, sk, &fl_gw6);
999 err = (*dst)->error;
1000 if (err)
1001 goto out_err_release;
1002 }
1003 }
1004 #endif
1005
1006 return 0;
1007
1008 out_err_release:
1009 dst_release(*dst);
1010 *dst = NULL;
1011 out_err:
1012 if (err == -ENETUNREACH)
1013 IP6_INC_STATS(net, NULL, IPSTATS_MIB_OUTNOROUTES);
1014 return err;
1015 }
1016
1017 /**
1018 * ip6_dst_lookup - perform route lookup on flow
1019 * @sk: socket which provides route info
1020 * @dst: pointer to dst_entry * for result
1021 * @fl6: flow to lookup
1022 *
1023 * This function performs a route lookup on the given flow.
1024 *
1025 * It returns zero on success, or a standard errno code on error.
1026 */
1027 int ip6_dst_lookup(struct net *net, struct sock *sk, struct dst_entry **dst,
1028 struct flowi6 *fl6)
1029 {
1030 *dst = NULL;
1031 return ip6_dst_lookup_tail(net, sk, dst, fl6);
1032 }
1033 EXPORT_SYMBOL_GPL(ip6_dst_lookup);
1034
1035 /**
1036 * ip6_dst_lookup_flow - perform route lookup on flow with ipsec
1037 * @sk: socket which provides route info
1038 * @fl6: flow to lookup
1039 * @final_dst: final destination address for ipsec lookup
1040 *
1041 * This function performs a route lookup on the given flow.
1042 *
1043 * It returns a valid dst pointer on success, or a pointer encoded
1044 * error code.
1045 */
1046 struct dst_entry *ip6_dst_lookup_flow(const struct sock *sk, struct flowi6 *fl6,
1047 const struct in6_addr *final_dst)
1048 {
1049 struct dst_entry *dst = NULL;
1050 int err;
1051
1052 err = ip6_dst_lookup_tail(sock_net(sk), sk, &dst, fl6);
1053 if (err)
1054 return ERR_PTR(err);
1055 if (final_dst)
1056 fl6->daddr = *final_dst;
1057 if (!fl6->flowi6_oif)
1058 fl6->flowi6_oif = l3mdev_fib_oif(dst->dev);
1059
1060 return xfrm_lookup_route(sock_net(sk), dst, flowi6_to_flowi(fl6), sk, 0);
1061 }
1062 EXPORT_SYMBOL_GPL(ip6_dst_lookup_flow);
1063
1064 /**
1065 * ip6_sk_dst_lookup_flow - perform socket cached route lookup on flow
1066 * @sk: socket which provides the dst cache and route info
1067 * @fl6: flow to lookup
1068 * @final_dst: final destination address for ipsec lookup
1069 *
1070 * This function performs a route lookup on the given flow with the
1071 * possibility of using the cached route in the socket if it is valid.
1072 * It will take the socket dst lock when operating on the dst cache.
1073 * As a result, this function can only be used in process context.
1074 *
1075 * It returns a valid dst pointer on success, or a pointer encoded
1076 * error code.
1077 */
1078 struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
1079 const struct in6_addr *final_dst)
1080 {
1081 struct dst_entry *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie);
1082
1083 dst = ip6_sk_dst_check(sk, dst, fl6);
1084 if (!dst)
1085 dst = ip6_dst_lookup_flow(sk, fl6, final_dst);
1086
1087 return dst;
1088 }
1089 EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup_flow);
1090
1091 static inline int ip6_ufo_append_data(struct sock *sk,
1092 struct sk_buff_head *queue,
1093 int getfrag(void *from, char *to, int offset, int len,
1094 int odd, struct sk_buff *skb),
1095 void *from, int length, int hh_len, int fragheaderlen,
1096 int exthdrlen, int transhdrlen, int mtu,
1097 unsigned int flags, const struct flowi6 *fl6)
1098
1099 {
1100 struct sk_buff *skb;
1101 int err;
1102
1103 /* There is support for UDP large send offload by network
1104 * device, so create one single skb packet containing complete
1105 * udp datagram
1106 */
1107 skb = skb_peek_tail(queue);
1108 if (!skb) {
1109 skb = sock_alloc_send_skb(sk,
1110 hh_len + fragheaderlen + transhdrlen + 20,
1111 (flags & MSG_DONTWAIT), &err);
1112 if (!skb)
1113 return err;
1114
1115 /* reserve space for Hardware header */
1116 skb_reserve(skb, hh_len);
1117
1118 /* create space for UDP/IP header */
1119 skb_put(skb, fragheaderlen + transhdrlen);
1120
1121 /* initialize network header pointer */
1122 skb_set_network_header(skb, exthdrlen);
1123
1124 /* initialize protocol header pointer */
1125 skb->transport_header = skb->network_header + fragheaderlen;
1126
1127 skb->protocol = htons(ETH_P_IPV6);
1128 skb->csum = 0;
1129
1130 __skb_queue_tail(queue, skb);
1131 } else if (skb_is_gso(skb)) {
1132 goto append;
1133 }
1134
1135 skb->ip_summed = CHECKSUM_PARTIAL;
1136 /* Specify the length of each IPv6 datagram fragment.
1137 * It has to be a multiple of 8.
1138 */
1139 skb_shinfo(skb)->gso_size = (mtu - fragheaderlen -
1140 sizeof(struct frag_hdr)) & ~7;
1141 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
1142 skb_shinfo(skb)->ip6_frag_id = ipv6_select_ident(sock_net(sk),
1143 &fl6->daddr,
1144 &fl6->saddr);
1145
1146 append:
1147 return skb_append_datato_frags(sk, skb, getfrag, from,
1148 (length - transhdrlen));
1149 }
1150
1151 static inline struct ipv6_opt_hdr *ip6_opt_dup(struct ipv6_opt_hdr *src,
1152 gfp_t gfp)
1153 {
1154 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL;
1155 }
1156
1157 static inline struct ipv6_rt_hdr *ip6_rthdr_dup(struct ipv6_rt_hdr *src,
1158 gfp_t gfp)
1159 {
1160 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL;
1161 }
1162
1163 static void ip6_append_data_mtu(unsigned int *mtu,
1164 int *maxfraglen,
1165 unsigned int fragheaderlen,
1166 struct sk_buff *skb,
1167 struct rt6_info *rt,
1168 unsigned int orig_mtu)
1169 {
1170 if (!(rt->dst.flags & DST_XFRM_TUNNEL)) {
1171 if (!skb) {
1172 /* first fragment, reserve header_len */
1173 *mtu = orig_mtu - rt->dst.header_len;
1174
1175 } else {
1176 /*
1177 * this fragment is not first, the headers
1178 * space is regarded as data space.
1179 */
1180 *mtu = orig_mtu;
1181 }
1182 *maxfraglen = ((*mtu - fragheaderlen) & ~7)
1183 + fragheaderlen - sizeof(struct frag_hdr);
1184 }
1185 }
1186
1187 static int ip6_setup_cork(struct sock *sk, struct inet_cork_full *cork,
1188 struct inet6_cork *v6_cork, struct ipcm6_cookie *ipc6,
1189 struct rt6_info *rt, struct flowi6 *fl6)
1190 {
1191 struct ipv6_pinfo *np = inet6_sk(sk);
1192 unsigned int mtu;
1193 struct ipv6_txoptions *opt = ipc6->opt;
1194
1195 /*
1196 * setup for corking
1197 */
1198 if (opt) {
1199 if (WARN_ON(v6_cork->opt))
1200 return -EINVAL;
1201
1202 v6_cork->opt = kzalloc(opt->tot_len, sk->sk_allocation);
1203 if (unlikely(!v6_cork->opt))
1204 return -ENOBUFS;
1205
1206 v6_cork->opt->tot_len = opt->tot_len;
1207 v6_cork->opt->opt_flen = opt->opt_flen;
1208 v6_cork->opt->opt_nflen = opt->opt_nflen;
1209
1210 v6_cork->opt->dst0opt = ip6_opt_dup(opt->dst0opt,
1211 sk->sk_allocation);
1212 if (opt->dst0opt && !v6_cork->opt->dst0opt)
1213 return -ENOBUFS;
1214
1215 v6_cork->opt->dst1opt = ip6_opt_dup(opt->dst1opt,
1216 sk->sk_allocation);
1217 if (opt->dst1opt && !v6_cork->opt->dst1opt)
1218 return -ENOBUFS;
1219
1220 v6_cork->opt->hopopt = ip6_opt_dup(opt->hopopt,
1221 sk->sk_allocation);
1222 if (opt->hopopt && !v6_cork->opt->hopopt)
1223 return -ENOBUFS;
1224
1225 v6_cork->opt->srcrt = ip6_rthdr_dup(opt->srcrt,
1226 sk->sk_allocation);
1227 if (opt->srcrt && !v6_cork->opt->srcrt)
1228 return -ENOBUFS;
1229
1230 /* need source address above miyazawa*/
1231 }
1232 dst_hold(&rt->dst);
1233 cork->base.dst = &rt->dst;
1234 cork->fl.u.ip6 = *fl6;
1235 v6_cork->hop_limit = ipc6->hlimit;
1236 v6_cork->tclass = ipc6->tclass;
1237 if (rt->dst.flags & DST_XFRM_TUNNEL)
1238 mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ?
1239 rt->dst.dev->mtu : dst_mtu(&rt->dst);
1240 else
1241 mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ?
1242 rt->dst.dev->mtu : dst_mtu(rt->dst.path);
1243 if (np->frag_size < mtu) {
1244 if (np->frag_size)
1245 mtu = np->frag_size;
1246 }
1247 cork->base.fragsize = mtu;
1248 if (dst_allfrag(rt->dst.path))
1249 cork->base.flags |= IPCORK_ALLFRAG;
1250 cork->base.length = 0;
1251
1252 return 0;
1253 }
1254
1255 static int __ip6_append_data(struct sock *sk,
1256 struct flowi6 *fl6,
1257 struct sk_buff_head *queue,
1258 struct inet_cork *cork,
1259 struct inet6_cork *v6_cork,
1260 struct page_frag *pfrag,
1261 int getfrag(void *from, char *to, int offset,
1262 int len, int odd, struct sk_buff *skb),
1263 void *from, int length, int transhdrlen,
1264 unsigned int flags, struct ipcm6_cookie *ipc6,
1265 const struct sockcm_cookie *sockc)
1266 {
1267 struct sk_buff *skb, *skb_prev = NULL;
1268 unsigned int maxfraglen, fragheaderlen, mtu, orig_mtu;
1269 int exthdrlen = 0;
1270 int dst_exthdrlen = 0;
1271 int hh_len;
1272 int copy;
1273 int err;
1274 int offset = 0;
1275 __u8 tx_flags = 0;
1276 u32 tskey = 0;
1277 struct rt6_info *rt = (struct rt6_info *)cork->dst;
1278 struct ipv6_txoptions *opt = v6_cork->opt;
1279 int csummode = CHECKSUM_NONE;
1280 unsigned int maxnonfragsize, headersize;
1281
1282 skb = skb_peek_tail(queue);
1283 if (!skb) {
1284 exthdrlen = opt ? opt->opt_flen : 0;
1285 dst_exthdrlen = rt->dst.header_len - rt->rt6i_nfheader_len;
1286 }
1287
1288 mtu = cork->fragsize;
1289 orig_mtu = mtu;
1290
1291 hh_len = LL_RESERVED_SPACE(rt->dst.dev);
1292
1293 fragheaderlen = sizeof(struct ipv6hdr) + rt->rt6i_nfheader_len +
1294 (opt ? opt->opt_nflen : 0);
1295 maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen -
1296 sizeof(struct frag_hdr);
1297
1298 headersize = sizeof(struct ipv6hdr) +
1299 (opt ? opt->opt_flen + opt->opt_nflen : 0) +
1300 (dst_allfrag(&rt->dst) ?
1301 sizeof(struct frag_hdr) : 0) +
1302 rt->rt6i_nfheader_len;
1303
1304 if (cork->length + length > mtu - headersize && ipc6->dontfrag &&
1305 (sk->sk_protocol == IPPROTO_UDP ||
1306 sk->sk_protocol == IPPROTO_RAW)) {
1307 ipv6_local_rxpmtu(sk, fl6, mtu - headersize +
1308 sizeof(struct ipv6hdr));
1309 goto emsgsize;
1310 }
1311
1312 if (ip6_sk_ignore_df(sk))
1313 maxnonfragsize = sizeof(struct ipv6hdr) + IPV6_MAXPLEN;
1314 else
1315 maxnonfragsize = mtu;
1316
1317 if (cork->length + length > maxnonfragsize - headersize) {
1318 emsgsize:
1319 ipv6_local_error(sk, EMSGSIZE, fl6,
1320 mtu - headersize +
1321 sizeof(struct ipv6hdr));
1322 return -EMSGSIZE;
1323 }
1324
1325 /* CHECKSUM_PARTIAL only with no extension headers and when
1326 * we are not going to fragment
1327 */
1328 if (transhdrlen && sk->sk_protocol == IPPROTO_UDP &&
1329 headersize == sizeof(struct ipv6hdr) &&
1330 length < mtu - headersize &&
1331 !(flags & MSG_MORE) &&
1332 rt->dst.dev->features & (NETIF_F_IPV6_CSUM | NETIF_F_HW_CSUM))
1333 csummode = CHECKSUM_PARTIAL;
1334
1335 if (sk->sk_type == SOCK_DGRAM || sk->sk_type == SOCK_RAW) {
1336 sock_tx_timestamp(sk, sockc->tsflags, &tx_flags);
1337 if (tx_flags & SKBTX_ANY_SW_TSTAMP &&
1338 sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)
1339 tskey = sk->sk_tskey++;
1340 }
1341
1342 /*
1343 * Let's try using as much space as possible.
1344 * Use MTU if total length of the message fits into the MTU.
1345 * Otherwise, we need to reserve fragment header and
1346 * fragment alignment (= 8-15 octects, in total).
1347 *
1348 * Note that we may need to "move" the data from the tail of
1349 * of the buffer to the new fragment when we split
1350 * the message.
1351 *
1352 * FIXME: It may be fragmented into multiple chunks
1353 * at once if non-fragmentable extension headers
1354 * are too large.
1355 * --yoshfuji
1356 */
1357
1358 cork->length += length;
1359 if (((length > mtu) ||
1360 (skb && skb_is_gso(skb))) &&
1361 (sk->sk_protocol == IPPROTO_UDP) &&
1362 (rt->dst.dev->features & NETIF_F_UFO) &&
1363 (sk->sk_type == SOCK_DGRAM) && !udp_get_no_check6_tx(sk)) {
1364 err = ip6_ufo_append_data(sk, queue, getfrag, from, length,
1365 hh_len, fragheaderlen, exthdrlen,
1366 transhdrlen, mtu, flags, fl6);
1367 if (err)
1368 goto error;
1369 return 0;
1370 }
1371
1372 if (!skb)
1373 goto alloc_new_skb;
1374
1375 while (length > 0) {
1376 /* Check if the remaining data fits into current packet. */
1377 copy = (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len;
1378 if (copy < length)
1379 copy = maxfraglen - skb->len;
1380
1381 if (copy <= 0) {
1382 char *data;
1383 unsigned int datalen;
1384 unsigned int fraglen;
1385 unsigned int fraggap;
1386 unsigned int alloclen;
1387 alloc_new_skb:
1388 /* There's no room in the current skb */
1389 if (skb)
1390 fraggap = skb->len - maxfraglen;
1391 else
1392 fraggap = 0;
1393 /* update mtu and maxfraglen if necessary */
1394 if (!skb || !skb_prev)
1395 ip6_append_data_mtu(&mtu, &maxfraglen,
1396 fragheaderlen, skb, rt,
1397 orig_mtu);
1398
1399 skb_prev = skb;
1400
1401 /*
1402 * If remaining data exceeds the mtu,
1403 * we know we need more fragment(s).
1404 */
1405 datalen = length + fraggap;
1406
1407 if (datalen > (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen)
1408 datalen = maxfraglen - fragheaderlen - rt->dst.trailer_len;
1409 if ((flags & MSG_MORE) &&
1410 !(rt->dst.dev->features&NETIF_F_SG))
1411 alloclen = mtu;
1412 else
1413 alloclen = datalen + fragheaderlen;
1414
1415 alloclen += dst_exthdrlen;
1416
1417 if (datalen != length + fraggap) {
1418 /*
1419 * this is not the last fragment, the trailer
1420 * space is regarded as data space.
1421 */
1422 datalen += rt->dst.trailer_len;
1423 }
1424
1425 alloclen += rt->dst.trailer_len;
1426 fraglen = datalen + fragheaderlen;
1427
1428 /*
1429 * We just reserve space for fragment header.
1430 * Note: this may be overallocation if the message
1431 * (without MSG_MORE) fits into the MTU.
1432 */
1433 alloclen += sizeof(struct frag_hdr);
1434
1435 if (transhdrlen) {
1436 skb = sock_alloc_send_skb(sk,
1437 alloclen + hh_len,
1438 (flags & MSG_DONTWAIT), &err);
1439 } else {
1440 skb = NULL;
1441 if (atomic_read(&sk->sk_wmem_alloc) <=
1442 2 * sk->sk_sndbuf)
1443 skb = sock_wmalloc(sk,
1444 alloclen + hh_len, 1,
1445 sk->sk_allocation);
1446 if (unlikely(!skb))
1447 err = -ENOBUFS;
1448 }
1449 if (!skb)
1450 goto error;
1451 /*
1452 * Fill in the control structures
1453 */
1454 skb->protocol = htons(ETH_P_IPV6);
1455 skb->ip_summed = csummode;
1456 skb->csum = 0;
1457 /* reserve for fragmentation and ipsec header */
1458 skb_reserve(skb, hh_len + sizeof(struct frag_hdr) +
1459 dst_exthdrlen);
1460
1461 /* Only the initial fragment is time stamped */
1462 skb_shinfo(skb)->tx_flags = tx_flags;
1463 tx_flags = 0;
1464 skb_shinfo(skb)->tskey = tskey;
1465 tskey = 0;
1466
1467 /*
1468 * Find where to start putting bytes
1469 */
1470 data = skb_put(skb, fraglen);
1471 skb_set_network_header(skb, exthdrlen);
1472 data += fragheaderlen;
1473 skb->transport_header = (skb->network_header +
1474 fragheaderlen);
1475 if (fraggap) {
1476 skb->csum = skb_copy_and_csum_bits(
1477 skb_prev, maxfraglen,
1478 data + transhdrlen, fraggap, 0);
1479 skb_prev->csum = csum_sub(skb_prev->csum,
1480 skb->csum);
1481 data += fraggap;
1482 pskb_trim_unique(skb_prev, maxfraglen);
1483 }
1484 copy = datalen - transhdrlen - fraggap;
1485
1486 if (copy < 0) {
1487 err = -EINVAL;
1488 kfree_skb(skb);
1489 goto error;
1490 } else if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) {
1491 err = -EFAULT;
1492 kfree_skb(skb);
1493 goto error;
1494 }
1495
1496 offset += copy;
1497 length -= datalen - fraggap;
1498 transhdrlen = 0;
1499 exthdrlen = 0;
1500 dst_exthdrlen = 0;
1501
1502 /*
1503 * Put the packet on the pending queue
1504 */
1505 __skb_queue_tail(queue, skb);
1506 continue;
1507 }
1508
1509 if (copy > length)
1510 copy = length;
1511
1512 if (!(rt->dst.dev->features&NETIF_F_SG)) {
1513 unsigned int off;
1514
1515 off = skb->len;
1516 if (getfrag(from, skb_put(skb, copy),
1517 offset, copy, off, skb) < 0) {
1518 __skb_trim(skb, off);
1519 err = -EFAULT;
1520 goto error;
1521 }
1522 } else {
1523 int i = skb_shinfo(skb)->nr_frags;
1524
1525 err = -ENOMEM;
1526 if (!sk_page_frag_refill(sk, pfrag))
1527 goto error;
1528
1529 if (!skb_can_coalesce(skb, i, pfrag->page,
1530 pfrag->offset)) {
1531 err = -EMSGSIZE;
1532 if (i == MAX_SKB_FRAGS)
1533 goto error;
1534
1535 __skb_fill_page_desc(skb, i, pfrag->page,
1536 pfrag->offset, 0);
1537 skb_shinfo(skb)->nr_frags = ++i;
1538 get_page(pfrag->page);
1539 }
1540 copy = min_t(int, copy, pfrag->size - pfrag->offset);
1541 if (getfrag(from,
1542 page_address(pfrag->page) + pfrag->offset,
1543 offset, copy, skb->len, skb) < 0)
1544 goto error_efault;
1545
1546 pfrag->offset += copy;
1547 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
1548 skb->len += copy;
1549 skb->data_len += copy;
1550 skb->truesize += copy;
1551 atomic_add(copy, &sk->sk_wmem_alloc);
1552 }
1553 offset += copy;
1554 length -= copy;
1555 }
1556
1557 return 0;
1558
1559 error_efault:
1560 err = -EFAULT;
1561 error:
1562 cork->length -= length;
1563 IP6_INC_STATS(sock_net(sk), rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS);
1564 return err;
1565 }
1566
1567 int ip6_append_data(struct sock *sk,
1568 int getfrag(void *from, char *to, int offset, int len,
1569 int odd, struct sk_buff *skb),
1570 void *from, int length, int transhdrlen,
1571 struct ipcm6_cookie *ipc6, struct flowi6 *fl6,
1572 struct rt6_info *rt, unsigned int flags,
1573 const struct sockcm_cookie *sockc)
1574 {
1575 struct inet_sock *inet = inet_sk(sk);
1576 struct ipv6_pinfo *np = inet6_sk(sk);
1577 int exthdrlen;
1578 int err;
1579
1580 if (flags&MSG_PROBE)
1581 return 0;
1582 if (skb_queue_empty(&sk->sk_write_queue)) {
1583 /*
1584 * setup for corking
1585 */
1586 err = ip6_setup_cork(sk, &inet->cork, &np->cork,
1587 ipc6, rt, fl6);
1588 if (err)
1589 return err;
1590
1591 exthdrlen = (ipc6->opt ? ipc6->opt->opt_flen : 0);
1592 length += exthdrlen;
1593 transhdrlen += exthdrlen;
1594 } else {
1595 fl6 = &inet->cork.fl.u.ip6;
1596 transhdrlen = 0;
1597 }
1598
1599 return __ip6_append_data(sk, fl6, &sk->sk_write_queue, &inet->cork.base,
1600 &np->cork, sk_page_frag(sk), getfrag,
1601 from, length, transhdrlen, flags, ipc6, sockc);
1602 }
1603 EXPORT_SYMBOL_GPL(ip6_append_data);
1604
1605 static void ip6_cork_release(struct inet_cork_full *cork,
1606 struct inet6_cork *v6_cork)
1607 {
1608 if (v6_cork->opt) {
1609 kfree(v6_cork->opt->dst0opt);
1610 kfree(v6_cork->opt->dst1opt);
1611 kfree(v6_cork->opt->hopopt);
1612 kfree(v6_cork->opt->srcrt);
1613 kfree(v6_cork->opt);
1614 v6_cork->opt = NULL;
1615 }
1616
1617 if (cork->base.dst) {
1618 dst_release(cork->base.dst);
1619 cork->base.dst = NULL;
1620 cork->base.flags &= ~IPCORK_ALLFRAG;
1621 }
1622 memset(&cork->fl, 0, sizeof(cork->fl));
1623 }
1624
1625 struct sk_buff *__ip6_make_skb(struct sock *sk,
1626 struct sk_buff_head *queue,
1627 struct inet_cork_full *cork,
1628 struct inet6_cork *v6_cork)
1629 {
1630 struct sk_buff *skb, *tmp_skb;
1631 struct sk_buff **tail_skb;
1632 struct in6_addr final_dst_buf, *final_dst = &final_dst_buf;
1633 struct ipv6_pinfo *np = inet6_sk(sk);
1634 struct net *net = sock_net(sk);
1635 struct ipv6hdr *hdr;
1636 struct ipv6_txoptions *opt = v6_cork->opt;
1637 struct rt6_info *rt = (struct rt6_info *)cork->base.dst;
1638 struct flowi6 *fl6 = &cork->fl.u.ip6;
1639 unsigned char proto = fl6->flowi6_proto;
1640
1641 skb = __skb_dequeue(queue);
1642 if (!skb)
1643 goto out;
1644 tail_skb = &(skb_shinfo(skb)->frag_list);
1645
1646 /* move skb->data to ip header from ext header */
1647 if (skb->data < skb_network_header(skb))
1648 __skb_pull(skb, skb_network_offset(skb));
1649 while ((tmp_skb = __skb_dequeue(queue)) != NULL) {
1650 __skb_pull(tmp_skb, skb_network_header_len(skb));
1651 *tail_skb = tmp_skb;
1652 tail_skb = &(tmp_skb->next);
1653 skb->len += tmp_skb->len;
1654 skb->data_len += tmp_skb->len;
1655 skb->truesize += tmp_skb->truesize;
1656 tmp_skb->destructor = NULL;
1657 tmp_skb->sk = NULL;
1658 }
1659
1660 /* Allow local fragmentation. */
1661 skb->ignore_df = ip6_sk_ignore_df(sk);
1662
1663 *final_dst = fl6->daddr;
1664 __skb_pull(skb, skb_network_header_len(skb));
1665 if (opt && opt->opt_flen)
1666 ipv6_push_frag_opts(skb, opt, &proto);
1667 if (opt && opt->opt_nflen)
1668 ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst);
1669
1670 skb_push(skb, sizeof(struct ipv6hdr));
1671 skb_reset_network_header(skb);
1672 hdr = ipv6_hdr(skb);
1673
1674 ip6_flow_hdr(hdr, v6_cork->tclass,
1675 ip6_make_flowlabel(net, skb, fl6->flowlabel,
1676 np->autoflowlabel, fl6));
1677 hdr->hop_limit = v6_cork->hop_limit;
1678 hdr->nexthdr = proto;
1679 hdr->saddr = fl6->saddr;
1680 hdr->daddr = *final_dst;
1681
1682 skb->priority = sk->sk_priority;
1683 skb->mark = sk->sk_mark;
1684
1685 skb_dst_set(skb, dst_clone(&rt->dst));
1686 IP6_UPD_PO_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUT, skb->len);
1687 if (proto == IPPROTO_ICMPV6) {
1688 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
1689
1690 ICMP6MSGOUT_INC_STATS(net, idev, icmp6_hdr(skb)->icmp6_type);
1691 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
1692 }
1693
1694 ip6_cork_release(cork, v6_cork);
1695 out:
1696 return skb;
1697 }
1698
1699 int ip6_send_skb(struct sk_buff *skb)
1700 {
1701 struct net *net = sock_net(skb->sk);
1702 struct rt6_info *rt = (struct rt6_info *)skb_dst(skb);
1703 int err;
1704
1705 err = ip6_local_out(net, skb->sk, skb);
1706 if (err) {
1707 if (err > 0)
1708 err = net_xmit_errno(err);
1709 if (err)
1710 IP6_INC_STATS(net, rt->rt6i_idev,
1711 IPSTATS_MIB_OUTDISCARDS);
1712 }
1713
1714 return err;
1715 }
1716
1717 int ip6_push_pending_frames(struct sock *sk)
1718 {
1719 struct sk_buff *skb;
1720
1721 skb = ip6_finish_skb(sk);
1722 if (!skb)
1723 return 0;
1724
1725 return ip6_send_skb(skb);
1726 }
1727 EXPORT_SYMBOL_GPL(ip6_push_pending_frames);
1728
1729 static void __ip6_flush_pending_frames(struct sock *sk,
1730 struct sk_buff_head *queue,
1731 struct inet_cork_full *cork,
1732 struct inet6_cork *v6_cork)
1733 {
1734 struct sk_buff *skb;
1735
1736 while ((skb = __skb_dequeue_tail(queue)) != NULL) {
1737 if (skb_dst(skb))
1738 IP6_INC_STATS(sock_net(sk), ip6_dst_idev(skb_dst(skb)),
1739 IPSTATS_MIB_OUTDISCARDS);
1740 kfree_skb(skb);
1741 }
1742
1743 ip6_cork_release(cork, v6_cork);
1744 }
1745
1746 void ip6_flush_pending_frames(struct sock *sk)
1747 {
1748 __ip6_flush_pending_frames(sk, &sk->sk_write_queue,
1749 &inet_sk(sk)->cork, &inet6_sk(sk)->cork);
1750 }
1751 EXPORT_SYMBOL_GPL(ip6_flush_pending_frames);
1752
1753 struct sk_buff *ip6_make_skb(struct sock *sk,
1754 int getfrag(void *from, char *to, int offset,
1755 int len, int odd, struct sk_buff *skb),
1756 void *from, int length, int transhdrlen,
1757 struct ipcm6_cookie *ipc6, struct flowi6 *fl6,
1758 struct rt6_info *rt, unsigned int flags,
1759 const struct sockcm_cookie *sockc)
1760 {
1761 struct inet_cork_full cork;
1762 struct inet6_cork v6_cork;
1763 struct sk_buff_head queue;
1764 int exthdrlen = (ipc6->opt ? ipc6->opt->opt_flen : 0);
1765 int err;
1766
1767 if (flags & MSG_PROBE)
1768 return NULL;
1769
1770 __skb_queue_head_init(&queue);
1771
1772 cork.base.flags = 0;
1773 cork.base.addr = 0;
1774 cork.base.opt = NULL;
1775 v6_cork.opt = NULL;
1776 err = ip6_setup_cork(sk, &cork, &v6_cork, ipc6, rt, fl6);
1777 if (err)
1778 return ERR_PTR(err);
1779
1780 if (ipc6->dontfrag < 0)
1781 ipc6->dontfrag = inet6_sk(sk)->dontfrag;
1782
1783 err = __ip6_append_data(sk, fl6, &queue, &cork.base, &v6_cork,
1784 &current->task_frag, getfrag, from,
1785 length + exthdrlen, transhdrlen + exthdrlen,
1786 flags, ipc6, sockc);
1787 if (err) {
1788 __ip6_flush_pending_frames(sk, &queue, &cork, &v6_cork);
1789 return ERR_PTR(err);
1790 }
1791
1792 return __ip6_make_skb(sk, &queue, &cork, &v6_cork);
1793 }
Linux with added FPC-III support