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Merge tag 'gfs2-4.7.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2...
[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 #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_network_seglen(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 /* The correct way to handle this would be to do
914 * ip6_route_get_saddr, and then ip6_route_output; however,
915 * the route-specific preferred source forces the
916 * ip6_route_output call _before_ ip6_route_get_saddr.
917 *
918 * In source specific routing (no src=any default route),
919 * ip6_route_output will fail given src=any saddr, though, so
920 * that's why we try it again later.
921 */
922 if (ipv6_addr_any(&fl6->saddr) && (!*dst || !(*dst)->error)) {
923 struct rt6_info *rt;
924 bool had_dst = *dst != NULL;
925
926 if (!had_dst)
927 *dst = ip6_route_output(net, sk, fl6);
928 rt = (*dst)->error ? NULL : (struct rt6_info *)*dst;
929 err = ip6_route_get_saddr(net, rt, &fl6->daddr,
930 sk ? inet6_sk(sk)->srcprefs : 0,
931 &fl6->saddr);
932 if (err)
933 goto out_err_release;
934
935 /* If we had an erroneous initial result, pretend it
936 * never existed and let the SA-enabled version take
937 * over.
938 */
939 if (!had_dst && (*dst)->error) {
940 dst_release(*dst);
941 *dst = NULL;
942 }
943
944 if (fl6->flowi6_oif)
945 flags |= RT6_LOOKUP_F_IFACE;
946 }
947
948 if (!*dst)
949 *dst = ip6_route_output_flags(net, sk, fl6, flags);
950
951 err = (*dst)->error;
952 if (err)
953 goto out_err_release;
954
955 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
956 /*
957 * Here if the dst entry we've looked up
958 * has a neighbour entry that is in the INCOMPLETE
959 * state and the src address from the flow is
960 * marked as OPTIMISTIC, we release the found
961 * dst entry and replace it instead with the
962 * dst entry of the nexthop router
963 */
964 rt = (struct rt6_info *) *dst;
965 rcu_read_lock_bh();
966 n = __ipv6_neigh_lookup_noref(rt->dst.dev,
967 rt6_nexthop(rt, &fl6->daddr));
968 err = n && !(n->nud_state & NUD_VALID) ? -EINVAL : 0;
969 rcu_read_unlock_bh();
970
971 if (err) {
972 struct inet6_ifaddr *ifp;
973 struct flowi6 fl_gw6;
974 int redirect;
975
976 ifp = ipv6_get_ifaddr(net, &fl6->saddr,
977 (*dst)->dev, 1);
978
979 redirect = (ifp && ifp->flags & IFA_F_OPTIMISTIC);
980 if (ifp)
981 in6_ifa_put(ifp);
982
983 if (redirect) {
984 /*
985 * We need to get the dst entry for the
986 * default router instead
987 */
988 dst_release(*dst);
989 memcpy(&fl_gw6, fl6, sizeof(struct flowi6));
990 memset(&fl_gw6.daddr, 0, sizeof(struct in6_addr));
991 *dst = ip6_route_output(net, sk, &fl_gw6);
992 err = (*dst)->error;
993 if (err)
994 goto out_err_release;
995 }
996 }
997 #endif
998
999 return 0;
1000
1001 out_err_release:
1002 if (err == -ENETUNREACH)
1003 IP6_INC_STATS(net, NULL, IPSTATS_MIB_OUTNOROUTES);
1004 dst_release(*dst);
1005 *dst = NULL;
1006 return err;
1007 }
1008
1009 /**
1010 * ip6_dst_lookup - perform route lookup on flow
1011 * @sk: socket which provides route info
1012 * @dst: pointer to dst_entry * for result
1013 * @fl6: flow to lookup
1014 *
1015 * This function performs a route lookup on the given flow.
1016 *
1017 * It returns zero on success, or a standard errno code on error.
1018 */
1019 int ip6_dst_lookup(struct net *net, struct sock *sk, struct dst_entry **dst,
1020 struct flowi6 *fl6)
1021 {
1022 *dst = NULL;
1023 return ip6_dst_lookup_tail(net, sk, dst, fl6);
1024 }
1025 EXPORT_SYMBOL_GPL(ip6_dst_lookup);
1026
1027 /**
1028 * ip6_dst_lookup_flow - perform route lookup on flow with ipsec
1029 * @sk: socket which provides route info
1030 * @fl6: flow to lookup
1031 * @final_dst: final destination address for ipsec lookup
1032 *
1033 * This function performs a route lookup on the given flow.
1034 *
1035 * It returns a valid dst pointer on success, or a pointer encoded
1036 * error code.
1037 */
1038 struct dst_entry *ip6_dst_lookup_flow(const struct sock *sk, struct flowi6 *fl6,
1039 const struct in6_addr *final_dst)
1040 {
1041 struct dst_entry *dst = NULL;
1042 int err;
1043
1044 err = ip6_dst_lookup_tail(sock_net(sk), sk, &dst, fl6);
1045 if (err)
1046 return ERR_PTR(err);
1047 if (final_dst)
1048 fl6->daddr = *final_dst;
1049 if (!fl6->flowi6_oif)
1050 fl6->flowi6_oif = l3mdev_fib_oif(dst->dev);
1051
1052 return xfrm_lookup_route(sock_net(sk), dst, flowi6_to_flowi(fl6), sk, 0);
1053 }
1054 EXPORT_SYMBOL_GPL(ip6_dst_lookup_flow);
1055
1056 /**
1057 * ip6_sk_dst_lookup_flow - perform socket cached route lookup on flow
1058 * @sk: socket which provides the dst cache and route info
1059 * @fl6: flow to lookup
1060 * @final_dst: final destination address for ipsec lookup
1061 *
1062 * This function performs a route lookup on the given flow with the
1063 * possibility of using the cached route in the socket if it is valid.
1064 * It will take the socket dst lock when operating on the dst cache.
1065 * As a result, this function can only be used in process context.
1066 *
1067 * It returns a valid dst pointer on success, or a pointer encoded
1068 * error code.
1069 */
1070 struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
1071 const struct in6_addr *final_dst)
1072 {
1073 struct dst_entry *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie);
1074
1075 dst = ip6_sk_dst_check(sk, dst, fl6);
1076 if (!dst)
1077 dst = ip6_dst_lookup_flow(sk, fl6, final_dst);
1078
1079 return dst;
1080 }
1081 EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup_flow);
1082
1083 static inline int ip6_ufo_append_data(struct sock *sk,
1084 struct sk_buff_head *queue,
1085 int getfrag(void *from, char *to, int offset, int len,
1086 int odd, struct sk_buff *skb),
1087 void *from, int length, int hh_len, int fragheaderlen,
1088 int exthdrlen, int transhdrlen, int mtu,
1089 unsigned int flags, const struct flowi6 *fl6)
1090
1091 {
1092 struct sk_buff *skb;
1093 int err;
1094
1095 /* There is support for UDP large send offload by network
1096 * device, so create one single skb packet containing complete
1097 * udp datagram
1098 */
1099 skb = skb_peek_tail(queue);
1100 if (!skb) {
1101 skb = sock_alloc_send_skb(sk,
1102 hh_len + fragheaderlen + transhdrlen + 20,
1103 (flags & MSG_DONTWAIT), &err);
1104 if (!skb)
1105 return err;
1106
1107 /* reserve space for Hardware header */
1108 skb_reserve(skb, hh_len);
1109
1110 /* create space for UDP/IP header */
1111 skb_put(skb, fragheaderlen + transhdrlen);
1112
1113 /* initialize network header pointer */
1114 skb_set_network_header(skb, exthdrlen);
1115
1116 /* initialize protocol header pointer */
1117 skb->transport_header = skb->network_header + fragheaderlen;
1118
1119 skb->protocol = htons(ETH_P_IPV6);
1120 skb->csum = 0;
1121
1122 __skb_queue_tail(queue, skb);
1123 } else if (skb_is_gso(skb)) {
1124 goto append;
1125 }
1126
1127 skb->ip_summed = CHECKSUM_PARTIAL;
1128 /* Specify the length of each IPv6 datagram fragment.
1129 * It has to be a multiple of 8.
1130 */
1131 skb_shinfo(skb)->gso_size = (mtu - fragheaderlen -
1132 sizeof(struct frag_hdr)) & ~7;
1133 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
1134 skb_shinfo(skb)->ip6_frag_id = ipv6_select_ident(sock_net(sk),
1135 &fl6->daddr,
1136 &fl6->saddr);
1137
1138 append:
1139 return skb_append_datato_frags(sk, skb, getfrag, from,
1140 (length - transhdrlen));
1141 }
1142
1143 static inline struct ipv6_opt_hdr *ip6_opt_dup(struct ipv6_opt_hdr *src,
1144 gfp_t gfp)
1145 {
1146 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL;
1147 }
1148
1149 static inline struct ipv6_rt_hdr *ip6_rthdr_dup(struct ipv6_rt_hdr *src,
1150 gfp_t gfp)
1151 {
1152 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL;
1153 }
1154
1155 static void ip6_append_data_mtu(unsigned int *mtu,
1156 int *maxfraglen,
1157 unsigned int fragheaderlen,
1158 struct sk_buff *skb,
1159 struct rt6_info *rt,
1160 unsigned int orig_mtu)
1161 {
1162 if (!(rt->dst.flags & DST_XFRM_TUNNEL)) {
1163 if (!skb) {
1164 /* first fragment, reserve header_len */
1165 *mtu = orig_mtu - rt->dst.header_len;
1166
1167 } else {
1168 /*
1169 * this fragment is not first, the headers
1170 * space is regarded as data space.
1171 */
1172 *mtu = orig_mtu;
1173 }
1174 *maxfraglen = ((*mtu - fragheaderlen) & ~7)
1175 + fragheaderlen - sizeof(struct frag_hdr);
1176 }
1177 }
1178
1179 static int ip6_setup_cork(struct sock *sk, struct inet_cork_full *cork,
1180 struct inet6_cork *v6_cork, struct ipcm6_cookie *ipc6,
1181 struct rt6_info *rt, struct flowi6 *fl6)
1182 {
1183 struct ipv6_pinfo *np = inet6_sk(sk);
1184 unsigned int mtu;
1185 struct ipv6_txoptions *opt = ipc6->opt;
1186
1187 /*
1188 * setup for corking
1189 */
1190 if (opt) {
1191 if (WARN_ON(v6_cork->opt))
1192 return -EINVAL;
1193
1194 v6_cork->opt = kzalloc(opt->tot_len, sk->sk_allocation);
1195 if (unlikely(!v6_cork->opt))
1196 return -ENOBUFS;
1197
1198 v6_cork->opt->tot_len = opt->tot_len;
1199 v6_cork->opt->opt_flen = opt->opt_flen;
1200 v6_cork->opt->opt_nflen = opt->opt_nflen;
1201
1202 v6_cork->opt->dst0opt = ip6_opt_dup(opt->dst0opt,
1203 sk->sk_allocation);
1204 if (opt->dst0opt && !v6_cork->opt->dst0opt)
1205 return -ENOBUFS;
1206
1207 v6_cork->opt->dst1opt = ip6_opt_dup(opt->dst1opt,
1208 sk->sk_allocation);
1209 if (opt->dst1opt && !v6_cork->opt->dst1opt)
1210 return -ENOBUFS;
1211
1212 v6_cork->opt->hopopt = ip6_opt_dup(opt->hopopt,
1213 sk->sk_allocation);
1214 if (opt->hopopt && !v6_cork->opt->hopopt)
1215 return -ENOBUFS;
1216
1217 v6_cork->opt->srcrt = ip6_rthdr_dup(opt->srcrt,
1218 sk->sk_allocation);
1219 if (opt->srcrt && !v6_cork->opt->srcrt)
1220 return -ENOBUFS;
1221
1222 /* need source address above miyazawa*/
1223 }
1224 dst_hold(&rt->dst);
1225 cork->base.dst = &rt->dst;
1226 cork->fl.u.ip6 = *fl6;
1227 v6_cork->hop_limit = ipc6->hlimit;
1228 v6_cork->tclass = ipc6->tclass;
1229 if (rt->dst.flags & DST_XFRM_TUNNEL)
1230 mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ?
1231 rt->dst.dev->mtu : dst_mtu(&rt->dst);
1232 else
1233 mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ?
1234 rt->dst.dev->mtu : dst_mtu(rt->dst.path);
1235 if (np->frag_size < mtu) {
1236 if (np->frag_size)
1237 mtu = np->frag_size;
1238 }
1239 cork->base.fragsize = mtu;
1240 if (dst_allfrag(rt->dst.path))
1241 cork->base.flags |= IPCORK_ALLFRAG;
1242 cork->base.length = 0;
1243
1244 return 0;
1245 }
1246
1247 static int __ip6_append_data(struct sock *sk,
1248 struct flowi6 *fl6,
1249 struct sk_buff_head *queue,
1250 struct inet_cork *cork,
1251 struct inet6_cork *v6_cork,
1252 struct page_frag *pfrag,
1253 int getfrag(void *from, char *to, int offset,
1254 int len, int odd, struct sk_buff *skb),
1255 void *from, int length, int transhdrlen,
1256 unsigned int flags, struct ipcm6_cookie *ipc6,
1257 const struct sockcm_cookie *sockc)
1258 {
1259 struct sk_buff *skb, *skb_prev = NULL;
1260 unsigned int maxfraglen, fragheaderlen, mtu, orig_mtu;
1261 int exthdrlen = 0;
1262 int dst_exthdrlen = 0;
1263 int hh_len;
1264 int copy;
1265 int err;
1266 int offset = 0;
1267 __u8 tx_flags = 0;
1268 u32 tskey = 0;
1269 struct rt6_info *rt = (struct rt6_info *)cork->dst;
1270 struct ipv6_txoptions *opt = v6_cork->opt;
1271 int csummode = CHECKSUM_NONE;
1272 unsigned int maxnonfragsize, headersize;
1273
1274 skb = skb_peek_tail(queue);
1275 if (!skb) {
1276 exthdrlen = opt ? opt->opt_flen : 0;
1277 dst_exthdrlen = rt->dst.header_len - rt->rt6i_nfheader_len;
1278 }
1279
1280 mtu = cork->fragsize;
1281 orig_mtu = mtu;
1282
1283 hh_len = LL_RESERVED_SPACE(rt->dst.dev);
1284
1285 fragheaderlen = sizeof(struct ipv6hdr) + rt->rt6i_nfheader_len +
1286 (opt ? opt->opt_nflen : 0);
1287 maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen -
1288 sizeof(struct frag_hdr);
1289
1290 headersize = sizeof(struct ipv6hdr) +
1291 (opt ? opt->opt_flen + opt->opt_nflen : 0) +
1292 (dst_allfrag(&rt->dst) ?
1293 sizeof(struct frag_hdr) : 0) +
1294 rt->rt6i_nfheader_len;
1295
1296 if (cork->length + length > mtu - headersize && ipc6->dontfrag &&
1297 (sk->sk_protocol == IPPROTO_UDP ||
1298 sk->sk_protocol == IPPROTO_RAW)) {
1299 ipv6_local_rxpmtu(sk, fl6, mtu - headersize +
1300 sizeof(struct ipv6hdr));
1301 goto emsgsize;
1302 }
1303
1304 if (ip6_sk_ignore_df(sk))
1305 maxnonfragsize = sizeof(struct ipv6hdr) + IPV6_MAXPLEN;
1306 else
1307 maxnonfragsize = mtu;
1308
1309 if (cork->length + length > maxnonfragsize - headersize) {
1310 emsgsize:
1311 ipv6_local_error(sk, EMSGSIZE, fl6,
1312 mtu - headersize +
1313 sizeof(struct ipv6hdr));
1314 return -EMSGSIZE;
1315 }
1316
1317 /* CHECKSUM_PARTIAL only with no extension headers and when
1318 * we are not going to fragment
1319 */
1320 if (transhdrlen && sk->sk_protocol == IPPROTO_UDP &&
1321 headersize == sizeof(struct ipv6hdr) &&
1322 length < mtu - headersize &&
1323 !(flags & MSG_MORE) &&
1324 rt->dst.dev->features & (NETIF_F_IPV6_CSUM | NETIF_F_HW_CSUM))
1325 csummode = CHECKSUM_PARTIAL;
1326
1327 if (sk->sk_type == SOCK_DGRAM || sk->sk_type == SOCK_RAW) {
1328 sock_tx_timestamp(sk, sockc->tsflags, &tx_flags);
1329 if (tx_flags & SKBTX_ANY_SW_TSTAMP &&
1330 sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)
1331 tskey = sk->sk_tskey++;
1332 }
1333
1334 /*
1335 * Let's try using as much space as possible.
1336 * Use MTU if total length of the message fits into the MTU.
1337 * Otherwise, we need to reserve fragment header and
1338 * fragment alignment (= 8-15 octects, in total).
1339 *
1340 * Note that we may need to "move" the data from the tail of
1341 * of the buffer to the new fragment when we split
1342 * the message.
1343 *
1344 * FIXME: It may be fragmented into multiple chunks
1345 * at once if non-fragmentable extension headers
1346 * are too large.
1347 * --yoshfuji
1348 */
1349
1350 cork->length += length;
1351 if (((length > mtu) ||
1352 (skb && skb_is_gso(skb))) &&
1353 (sk->sk_protocol == IPPROTO_UDP) &&
1354 (rt->dst.dev->features & NETIF_F_UFO) &&
1355 (sk->sk_type == SOCK_DGRAM) && !udp_get_no_check6_tx(sk)) {
1356 err = ip6_ufo_append_data(sk, queue, getfrag, from, length,
1357 hh_len, fragheaderlen, exthdrlen,
1358 transhdrlen, mtu, flags, fl6);
1359 if (err)
1360 goto error;
1361 return 0;
1362 }
1363
1364 if (!skb)
1365 goto alloc_new_skb;
1366
1367 while (length > 0) {
1368 /* Check if the remaining data fits into current packet. */
1369 copy = (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len;
1370 if (copy < length)
1371 copy = maxfraglen - skb->len;
1372
1373 if (copy <= 0) {
1374 char *data;
1375 unsigned int datalen;
1376 unsigned int fraglen;
1377 unsigned int fraggap;
1378 unsigned int alloclen;
1379 alloc_new_skb:
1380 /* There's no room in the current skb */
1381 if (skb)
1382 fraggap = skb->len - maxfraglen;
1383 else
1384 fraggap = 0;
1385 /* update mtu and maxfraglen if necessary */
1386 if (!skb || !skb_prev)
1387 ip6_append_data_mtu(&mtu, &maxfraglen,
1388 fragheaderlen, skb, rt,
1389 orig_mtu);
1390
1391 skb_prev = skb;
1392
1393 /*
1394 * If remaining data exceeds the mtu,
1395 * we know we need more fragment(s).
1396 */
1397 datalen = length + fraggap;
1398
1399 if (datalen > (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen)
1400 datalen = maxfraglen - fragheaderlen - rt->dst.trailer_len;
1401 if ((flags & MSG_MORE) &&
1402 !(rt->dst.dev->features&NETIF_F_SG))
1403 alloclen = mtu;
1404 else
1405 alloclen = datalen + fragheaderlen;
1406
1407 alloclen += dst_exthdrlen;
1408
1409 if (datalen != length + fraggap) {
1410 /*
1411 * this is not the last fragment, the trailer
1412 * space is regarded as data space.
1413 */
1414 datalen += rt->dst.trailer_len;
1415 }
1416
1417 alloclen += rt->dst.trailer_len;
1418 fraglen = datalen + fragheaderlen;
1419
1420 /*
1421 * We just reserve space for fragment header.
1422 * Note: this may be overallocation if the message
1423 * (without MSG_MORE) fits into the MTU.
1424 */
1425 alloclen += sizeof(struct frag_hdr);
1426
1427 if (transhdrlen) {
1428 skb = sock_alloc_send_skb(sk,
1429 alloclen + hh_len,
1430 (flags & MSG_DONTWAIT), &err);
1431 } else {
1432 skb = NULL;
1433 if (atomic_read(&sk->sk_wmem_alloc) <=
1434 2 * sk->sk_sndbuf)
1435 skb = sock_wmalloc(sk,
1436 alloclen + hh_len, 1,
1437 sk->sk_allocation);
1438 if (unlikely(!skb))
1439 err = -ENOBUFS;
1440 }
1441 if (!skb)
1442 goto error;
1443 /*
1444 * Fill in the control structures
1445 */
1446 skb->protocol = htons(ETH_P_IPV6);
1447 skb->ip_summed = csummode;
1448 skb->csum = 0;
1449 /* reserve for fragmentation and ipsec header */
1450 skb_reserve(skb, hh_len + sizeof(struct frag_hdr) +
1451 dst_exthdrlen);
1452
1453 /* Only the initial fragment is time stamped */
1454 skb_shinfo(skb)->tx_flags = tx_flags;
1455 tx_flags = 0;
1456 skb_shinfo(skb)->tskey = tskey;
1457 tskey = 0;
1458
1459 /*
1460 * Find where to start putting bytes
1461 */
1462 data = skb_put(skb, fraglen);
1463 skb_set_network_header(skb, exthdrlen);
1464 data += fragheaderlen;
1465 skb->transport_header = (skb->network_header +
1466 fragheaderlen);
1467 if (fraggap) {
1468 skb->csum = skb_copy_and_csum_bits(
1469 skb_prev, maxfraglen,
1470 data + transhdrlen, fraggap, 0);
1471 skb_prev->csum = csum_sub(skb_prev->csum,
1472 skb->csum);
1473 data += fraggap;
1474 pskb_trim_unique(skb_prev, maxfraglen);
1475 }
1476 copy = datalen - transhdrlen - fraggap;
1477
1478 if (copy < 0) {
1479 err = -EINVAL;
1480 kfree_skb(skb);
1481 goto error;
1482 } else if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) {
1483 err = -EFAULT;
1484 kfree_skb(skb);
1485 goto error;
1486 }
1487
1488 offset += copy;
1489 length -= datalen - fraggap;
1490 transhdrlen = 0;
1491 exthdrlen = 0;
1492 dst_exthdrlen = 0;
1493
1494 /*
1495 * Put the packet on the pending queue
1496 */
1497 __skb_queue_tail(queue, skb);
1498 continue;
1499 }
1500
1501 if (copy > length)
1502 copy = length;
1503
1504 if (!(rt->dst.dev->features&NETIF_F_SG)) {
1505 unsigned int off;
1506
1507 off = skb->len;
1508 if (getfrag(from, skb_put(skb, copy),
1509 offset, copy, off, skb) < 0) {
1510 __skb_trim(skb, off);
1511 err = -EFAULT;
1512 goto error;
1513 }
1514 } else {
1515 int i = skb_shinfo(skb)->nr_frags;
1516
1517 err = -ENOMEM;
1518 if (!sk_page_frag_refill(sk, pfrag))
1519 goto error;
1520
1521 if (!skb_can_coalesce(skb, i, pfrag->page,
1522 pfrag->offset)) {
1523 err = -EMSGSIZE;
1524 if (i == MAX_SKB_FRAGS)
1525 goto error;
1526
1527 __skb_fill_page_desc(skb, i, pfrag->page,
1528 pfrag->offset, 0);
1529 skb_shinfo(skb)->nr_frags = ++i;
1530 get_page(pfrag->page);
1531 }
1532 copy = min_t(int, copy, pfrag->size - pfrag->offset);
1533 if (getfrag(from,
1534 page_address(pfrag->page) + pfrag->offset,
1535 offset, copy, skb->len, skb) < 0)
1536 goto error_efault;
1537
1538 pfrag->offset += copy;
1539 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
1540 skb->len += copy;
1541 skb->data_len += copy;
1542 skb->truesize += copy;
1543 atomic_add(copy, &sk->sk_wmem_alloc);
1544 }
1545 offset += copy;
1546 length -= copy;
1547 }
1548
1549 return 0;
1550
1551 error_efault:
1552 err = -EFAULT;
1553 error:
1554 cork->length -= length;
1555 IP6_INC_STATS(sock_net(sk), rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS);
1556 return err;
1557 }
1558
1559 int ip6_append_data(struct sock *sk,
1560 int getfrag(void *from, char *to, int offset, int len,
1561 int odd, struct sk_buff *skb),
1562 void *from, int length, int transhdrlen,
1563 struct ipcm6_cookie *ipc6, struct flowi6 *fl6,
1564 struct rt6_info *rt, unsigned int flags,
1565 const struct sockcm_cookie *sockc)
1566 {
1567 struct inet_sock *inet = inet_sk(sk);
1568 struct ipv6_pinfo *np = inet6_sk(sk);
1569 int exthdrlen;
1570 int err;
1571
1572 if (flags&MSG_PROBE)
1573 return 0;
1574 if (skb_queue_empty(&sk->sk_write_queue)) {
1575 /*
1576 * setup for corking
1577 */
1578 err = ip6_setup_cork(sk, &inet->cork, &np->cork,
1579 ipc6, rt, fl6);
1580 if (err)
1581 return err;
1582
1583 exthdrlen = (ipc6->opt ? ipc6->opt->opt_flen : 0);
1584 length += exthdrlen;
1585 transhdrlen += exthdrlen;
1586 } else {
1587 fl6 = &inet->cork.fl.u.ip6;
1588 transhdrlen = 0;
1589 }
1590
1591 return __ip6_append_data(sk, fl6, &sk->sk_write_queue, &inet->cork.base,
1592 &np->cork, sk_page_frag(sk), getfrag,
1593 from, length, transhdrlen, flags, ipc6, sockc);
1594 }
1595 EXPORT_SYMBOL_GPL(ip6_append_data);
1596
1597 static void ip6_cork_release(struct inet_cork_full *cork,
1598 struct inet6_cork *v6_cork)
1599 {
1600 if (v6_cork->opt) {
1601 kfree(v6_cork->opt->dst0opt);
1602 kfree(v6_cork->opt->dst1opt);
1603 kfree(v6_cork->opt->hopopt);
1604 kfree(v6_cork->opt->srcrt);
1605 kfree(v6_cork->opt);
1606 v6_cork->opt = NULL;
1607 }
1608
1609 if (cork->base.dst) {
1610 dst_release(cork->base.dst);
1611 cork->base.dst = NULL;
1612 cork->base.flags &= ~IPCORK_ALLFRAG;
1613 }
1614 memset(&cork->fl, 0, sizeof(cork->fl));
1615 }
1616
1617 struct sk_buff *__ip6_make_skb(struct sock *sk,
1618 struct sk_buff_head *queue,
1619 struct inet_cork_full *cork,
1620 struct inet6_cork *v6_cork)
1621 {
1622 struct sk_buff *skb, *tmp_skb;
1623 struct sk_buff **tail_skb;
1624 struct in6_addr final_dst_buf, *final_dst = &final_dst_buf;
1625 struct ipv6_pinfo *np = inet6_sk(sk);
1626 struct net *net = sock_net(sk);
1627 struct ipv6hdr *hdr;
1628 struct ipv6_txoptions *opt = v6_cork->opt;
1629 struct rt6_info *rt = (struct rt6_info *)cork->base.dst;
1630 struct flowi6 *fl6 = &cork->fl.u.ip6;
1631 unsigned char proto = fl6->flowi6_proto;
1632
1633 skb = __skb_dequeue(queue);
1634 if (!skb)
1635 goto out;
1636 tail_skb = &(skb_shinfo(skb)->frag_list);
1637
1638 /* move skb->data to ip header from ext header */
1639 if (skb->data < skb_network_header(skb))
1640 __skb_pull(skb, skb_network_offset(skb));
1641 while ((tmp_skb = __skb_dequeue(queue)) != NULL) {
1642 __skb_pull(tmp_skb, skb_network_header_len(skb));
1643 *tail_skb = tmp_skb;
1644 tail_skb = &(tmp_skb->next);
1645 skb->len += tmp_skb->len;
1646 skb->data_len += tmp_skb->len;
1647 skb->truesize += tmp_skb->truesize;
1648 tmp_skb->destructor = NULL;
1649 tmp_skb->sk = NULL;
1650 }
1651
1652 /* Allow local fragmentation. */
1653 skb->ignore_df = ip6_sk_ignore_df(sk);
1654
1655 *final_dst = fl6->daddr;
1656 __skb_pull(skb, skb_network_header_len(skb));
1657 if (opt && opt->opt_flen)
1658 ipv6_push_frag_opts(skb, opt, &proto);
1659 if (opt && opt->opt_nflen)
1660 ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst);
1661
1662 skb_push(skb, sizeof(struct ipv6hdr));
1663 skb_reset_network_header(skb);
1664 hdr = ipv6_hdr(skb);
1665
1666 ip6_flow_hdr(hdr, v6_cork->tclass,
1667 ip6_make_flowlabel(net, skb, fl6->flowlabel,
1668 np->autoflowlabel, fl6));
1669 hdr->hop_limit = v6_cork->hop_limit;
1670 hdr->nexthdr = proto;
1671 hdr->saddr = fl6->saddr;
1672 hdr->daddr = *final_dst;
1673
1674 skb->priority = sk->sk_priority;
1675 skb->mark = sk->sk_mark;
1676
1677 skb_dst_set(skb, dst_clone(&rt->dst));
1678 IP6_UPD_PO_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUT, skb->len);
1679 if (proto == IPPROTO_ICMPV6) {
1680 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
1681
1682 ICMP6MSGOUT_INC_STATS(net, idev, icmp6_hdr(skb)->icmp6_type);
1683 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
1684 }
1685
1686 ip6_cork_release(cork, v6_cork);
1687 out:
1688 return skb;
1689 }
1690
1691 int ip6_send_skb(struct sk_buff *skb)
1692 {
1693 struct net *net = sock_net(skb->sk);
1694 struct rt6_info *rt = (struct rt6_info *)skb_dst(skb);
1695 int err;
1696
1697 err = ip6_local_out(net, skb->sk, skb);
1698 if (err) {
1699 if (err > 0)
1700 err = net_xmit_errno(err);
1701 if (err)
1702 IP6_INC_STATS(net, rt->rt6i_idev,
1703 IPSTATS_MIB_OUTDISCARDS);
1704 }
1705
1706 return err;
1707 }
1708
1709 int ip6_push_pending_frames(struct sock *sk)
1710 {
1711 struct sk_buff *skb;
1712
1713 skb = ip6_finish_skb(sk);
1714 if (!skb)
1715 return 0;
1716
1717 return ip6_send_skb(skb);
1718 }
1719 EXPORT_SYMBOL_GPL(ip6_push_pending_frames);
1720
1721 static void __ip6_flush_pending_frames(struct sock *sk,
1722 struct sk_buff_head *queue,
1723 struct inet_cork_full *cork,
1724 struct inet6_cork *v6_cork)
1725 {
1726 struct sk_buff *skb;
1727
1728 while ((skb = __skb_dequeue_tail(queue)) != NULL) {
1729 if (skb_dst(skb))
1730 IP6_INC_STATS(sock_net(sk), ip6_dst_idev(skb_dst(skb)),
1731 IPSTATS_MIB_OUTDISCARDS);
1732 kfree_skb(skb);
1733 }
1734
1735 ip6_cork_release(cork, v6_cork);
1736 }
1737
1738 void ip6_flush_pending_frames(struct sock *sk)
1739 {
1740 __ip6_flush_pending_frames(sk, &sk->sk_write_queue,
1741 &inet_sk(sk)->cork, &inet6_sk(sk)->cork);
1742 }
1743 EXPORT_SYMBOL_GPL(ip6_flush_pending_frames);
1744
1745 struct sk_buff *ip6_make_skb(struct sock *sk,
1746 int getfrag(void *from, char *to, int offset,
1747 int len, int odd, struct sk_buff *skb),
1748 void *from, int length, int transhdrlen,
1749 struct ipcm6_cookie *ipc6, struct flowi6 *fl6,
1750 struct rt6_info *rt, unsigned int flags,
1751 const struct sockcm_cookie *sockc)
1752 {
1753 struct inet_cork_full cork;
1754 struct inet6_cork v6_cork;
1755 struct sk_buff_head queue;
1756 int exthdrlen = (ipc6->opt ? ipc6->opt->opt_flen : 0);
1757 int err;
1758
1759 if (flags & MSG_PROBE)
1760 return NULL;
1761
1762 __skb_queue_head_init(&queue);
1763
1764 cork.base.flags = 0;
1765 cork.base.addr = 0;
1766 cork.base.opt = NULL;
1767 v6_cork.opt = NULL;
1768 err = ip6_setup_cork(sk, &cork, &v6_cork, ipc6, rt, fl6);
1769 if (err)
1770 return ERR_PTR(err);
1771
1772 if (ipc6->dontfrag < 0)
1773 ipc6->dontfrag = inet6_sk(sk)->dontfrag;
1774
1775 err = __ip6_append_data(sk, fl6, &queue, &cork.base, &v6_cork,
1776 &current->task_frag, getfrag, from,
1777 length + exthdrlen, transhdrlen + exthdrlen,
1778 flags, ipc6, sockc);
1779 if (err) {
1780 __ip6_flush_pending_frames(sk, &queue, &cork, &v6_cork);
1781 return ERR_PTR(err);
1782 }
1783
1784 return __ip6_make_skb(sk, &queue, &cork, &v6_cork);
1785 }
Linux kernel - Deliverables
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