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ipv6: ip6_sk_dst_check() must not assume ipv6 dst
[linux-2.6/btrfs-unstable.git] / net / ipv6 / ip6_output.c
blobd5d20cde8d92808387e171fb25b2fa701a06f275
1 /*
2 * IPv6 output functions
3 * Linux INET6 implementation
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 *
8 * Based on linux/net/ipv4/ip_output.c
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * as published by the Free Software Foundation; either version
13 * 2 of the License, or (at your option) any later version.
14 *
15 * Changes:
16 * A.N.Kuznetsov : airthmetics in fragmentation.
17 * extension headers are implemented.
18 * route changes now work.
19 * ip6_forward does not confuse sniffers.
20 * etc.
21 *
22 * H. von Brand : Added missing #include <linux/string.h>
23 * Imran Patel : frag id should be in NBO
24 * Kazunori MIYAZAWA @USAGI
25 * : add ip6_append_data and related functions
26 * for datagram xmit
27 */
28
29 #include <linux/errno.h>
30 #include <linux/kernel.h>
31 #include <linux/string.h>
32 #include <linux/socket.h>
33 #include <linux/net.h>
34 #include <linux/netdevice.h>
35 #include <linux/if_arp.h>
36 #include <linux/in6.h>
37 #include <linux/tcp.h>
38 #include <linux/route.h>
39 #include <linux/module.h>
40 #include <linux/slab.h>
41
42 #include <linux/netfilter.h>
43 #include <linux/netfilter_ipv6.h>
44
45 #include <net/sock.h>
46 #include <net/snmp.h>
47
48 #include <net/ipv6.h>
49 #include <net/ndisc.h>
50 #include <net/protocol.h>
51 #include <net/ip6_route.h>
52 #include <net/addrconf.h>
53 #include <net/rawv6.h>
54 #include <net/icmp.h>
55 #include <net/xfrm.h>
56 #include <net/checksum.h>
57 #include <linux/mroute6.h>
58
59 int __ip6_local_out(struct sk_buff *skb)
60 {
61 int len;
62
63 len = skb->len - sizeof(struct ipv6hdr);
64 if (len > IPV6_MAXPLEN)
65 len = 0;
66 ipv6_hdr(skb)->payload_len = htons(len);
67
68 return nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, skb, NULL,
69 skb_dst(skb)->dev, dst_output);
70 }
71
72 int ip6_local_out(struct sk_buff *skb)
73 {
74 int err;
75
76 err = __ip6_local_out(skb);
77 if (likely(err == 1))
78 err = dst_output(skb);
79
80 return err;
81 }
82 EXPORT_SYMBOL_GPL(ip6_local_out);
83
84 static int ip6_finish_output2(struct sk_buff *skb)
85 {
86 struct dst_entry *dst = skb_dst(skb);
87 struct net_device *dev = dst->dev;
88 struct neighbour *neigh;
89 struct in6_addr *nexthop;
90 int ret;
91
92 skb->protocol = htons(ETH_P_IPV6);
93 skb->dev = dev;
94
95 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) {
96 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
97
98 if (!(dev->flags & IFF_LOOPBACK) && sk_mc_loop(skb->sk) &&
99 ((mroute6_socket(dev_net(dev), skb) &&
100 !(IP6CB(skb)->flags & IP6SKB_FORWARDED)) ||
101 ipv6_chk_mcast_addr(dev, &ipv6_hdr(skb)->daddr,
102 &ipv6_hdr(skb)->saddr))) {
103 struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC);
104
105 /* Do not check for IFF_ALLMULTI; multicast routing
106 is not supported in any case.
107 */
108 if (newskb)
109 NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING,
110 newskb, NULL, newskb->dev,
111 dev_loopback_xmit);
112
113 if (ipv6_hdr(skb)->hop_limit == 0) {
114 IP6_INC_STATS(dev_net(dev), idev,
115 IPSTATS_MIB_OUTDISCARDS);
116 kfree_skb(skb);
117 return 0;
118 }
119 }
120
121 IP6_UPD_PO_STATS(dev_net(dev), idev, IPSTATS_MIB_OUTMCAST,
122 skb->len);
123
124 if (IPV6_ADDR_MC_SCOPE(&ipv6_hdr(skb)->daddr) <=
125 IPV6_ADDR_SCOPE_NODELOCAL &&
126 !(dev->flags & IFF_LOOPBACK)) {
127 kfree_skb(skb);
128 return 0;
129 }
130 }
131
132 rcu_read_lock_bh();
133 nexthop = rt6_nexthop((struct rt6_info *)dst, &ipv6_hdr(skb)->daddr);
134 neigh = __ipv6_neigh_lookup_noref(dst->dev, nexthop);
135 if (unlikely(!neigh))
136 neigh = __neigh_create(&nd_tbl, nexthop, dst->dev, false);
137 if (!IS_ERR(neigh)) {
138 ret = dst_neigh_output(dst, neigh, skb);
139 rcu_read_unlock_bh();
140 return ret;
141 }
142 rcu_read_unlock_bh();
143
144 IP6_INC_STATS_BH(dev_net(dst->dev),
145 ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
146 kfree_skb(skb);
147 return -EINVAL;
148 }
149
150 static int ip6_finish_output(struct sk_buff *skb)
151 {
152 if ((skb->len > ip6_skb_dst_mtu(skb) && !skb_is_gso(skb)) ||
153 dst_allfrag(skb_dst(skb)))
154 return ip6_fragment(skb, ip6_finish_output2);
155 else
156 return ip6_finish_output2(skb);
157 }
158
159 int ip6_output(struct sk_buff *skb)
160 {
161 struct net_device *dev = skb_dst(skb)->dev;
162 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
163 if (unlikely(idev->cnf.disable_ipv6)) {
164 IP6_INC_STATS(dev_net(dev), idev,
165 IPSTATS_MIB_OUTDISCARDS);
166 kfree_skb(skb);
167 return 0;
168 }
169
170 return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING, skb, NULL, dev,
171 ip6_finish_output,
172 !(IP6CB(skb)->flags & IP6SKB_REROUTED));
173 }
174
175 /*
176 * xmit an sk_buff (used by TCP, SCTP and DCCP)
177 */
178
179 int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
180 struct ipv6_txoptions *opt, int tclass)
181 {
182 struct net *net = sock_net(sk);
183 struct ipv6_pinfo *np = inet6_sk(sk);
184 struct in6_addr *first_hop = &fl6->daddr;
185 struct dst_entry *dst = skb_dst(skb);
186 struct ipv6hdr *hdr;
187 u8 proto = fl6->flowi6_proto;
188 int seg_len = skb->len;
189 int hlimit = -1;
190 u32 mtu;
191
192 if (opt) {
193 unsigned int head_room;
194
195 /* First: exthdrs may take lots of space (~8K for now)
196 MAX_HEADER is not enough.
197 */
198 head_room = opt->opt_nflen + opt->opt_flen;
199 seg_len += head_room;
200 head_room += sizeof(struct ipv6hdr) + LL_RESERVED_SPACE(dst->dev);
201
202 if (skb_headroom(skb) < head_room) {
203 struct sk_buff *skb2 = skb_realloc_headroom(skb, head_room);
204 if (skb2 == NULL) {
205 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
206 IPSTATS_MIB_OUTDISCARDS);
207 kfree_skb(skb);
208 return -ENOBUFS;
209 }
210 consume_skb(skb);
211 skb = skb2;
212 skb_set_owner_w(skb, sk);
213 }
214 if (opt->opt_flen)
215 ipv6_push_frag_opts(skb, opt, &proto);
216 if (opt->opt_nflen)
217 ipv6_push_nfrag_opts(skb, opt, &proto, &first_hop);
218 }
219
220 skb_push(skb, sizeof(struct ipv6hdr));
221 skb_reset_network_header(skb);
222 hdr = ipv6_hdr(skb);
223
224 /*
225 * Fill in the IPv6 header
226 */
227 if (np)
228 hlimit = np->hop_limit;
229 if (hlimit < 0)
230 hlimit = ip6_dst_hoplimit(dst);
231
232 ip6_flow_hdr(hdr, tclass, fl6->flowlabel);
233
234 hdr->payload_len = htons(seg_len);
235 hdr->nexthdr = proto;
236 hdr->hop_limit = hlimit;
237
238 hdr->saddr = fl6->saddr;
239 hdr->daddr = *first_hop;
240
241 skb->priority = sk->sk_priority;
242 skb->mark = sk->sk_mark;
243
244 mtu = dst_mtu(dst);
245 if ((skb->len <= mtu) || skb->local_df || skb_is_gso(skb)) {
246 IP6_UPD_PO_STATS(net, ip6_dst_idev(skb_dst(skb)),
247 IPSTATS_MIB_OUT, skb->len);
248 return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, skb, NULL,
249 dst->dev, dst_output);
250 }
251
252 skb->dev = dst->dev;
253 ipv6_local_error(sk, EMSGSIZE, fl6, mtu);
254 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_FRAGFAILS);
255 kfree_skb(skb);
256 return -EMSGSIZE;
257 }
258
259 EXPORT_SYMBOL(ip6_xmit);
260
261 static int ip6_call_ra_chain(struct sk_buff *skb, int sel)
262 {
263 struct ip6_ra_chain *ra;
264 struct sock *last = NULL;
265
266 read_lock(&ip6_ra_lock);
267 for (ra = ip6_ra_chain; ra; ra = ra->next) {
268 struct sock *sk = ra->sk;
269 if (sk && ra->sel == sel &&
270 (!sk->sk_bound_dev_if ||
271 sk->sk_bound_dev_if == skb->dev->ifindex)) {
272 if (last) {
273 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
274 if (skb2)
275 rawv6_rcv(last, skb2);
276 }
277 last = sk;
278 }
279 }
280
281 if (last) {
282 rawv6_rcv(last, skb);
283 read_unlock(&ip6_ra_lock);
284 return 1;
285 }
286 read_unlock(&ip6_ra_lock);
287 return 0;
288 }
289
290 static int ip6_forward_proxy_check(struct sk_buff *skb)
291 {
292 struct ipv6hdr *hdr = ipv6_hdr(skb);
293 u8 nexthdr = hdr->nexthdr;
294 __be16 frag_off;
295 int offset;
296
297 if (ipv6_ext_hdr(nexthdr)) {
298 offset = ipv6_skip_exthdr(skb, sizeof(*hdr), &nexthdr, &frag_off);
299 if (offset < 0)
300 return 0;
301 } else
302 offset = sizeof(struct ipv6hdr);
303
304 if (nexthdr == IPPROTO_ICMPV6) {
305 struct icmp6hdr *icmp6;
306
307 if (!pskb_may_pull(skb, (skb_network_header(skb) +
308 offset + 1 - skb->data)))
309 return 0;
310
311 icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset);
312
313 switch (icmp6->icmp6_type) {
314 case NDISC_ROUTER_SOLICITATION:
315 case NDISC_ROUTER_ADVERTISEMENT:
316 case NDISC_NEIGHBOUR_SOLICITATION:
317 case NDISC_NEIGHBOUR_ADVERTISEMENT:
318 case NDISC_REDIRECT:
319 /* For reaction involving unicast neighbor discovery
320 * message destined to the proxied address, pass it to
321 * input function.
322 */
323 return 1;
324 default:
325 break;
326 }
327 }
328
329 /*
330 * The proxying router can't forward traffic sent to a link-local
331 * address, so signal the sender and discard the packet. This
332 * behavior is clarified by the MIPv6 specification.
333 */
334 if (ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) {
335 dst_link_failure(skb);
336 return -1;
337 }
338
339 return 0;
340 }
341
342 static inline int ip6_forward_finish(struct sk_buff *skb)
343 {
344 return dst_output(skb);
345 }
346
347 int ip6_forward(struct sk_buff *skb)
348 {
349 struct dst_entry *dst = skb_dst(skb);
350 struct ipv6hdr *hdr = ipv6_hdr(skb);
351 struct inet6_skb_parm *opt = IP6CB(skb);
352 struct net *net = dev_net(dst->dev);
353 u32 mtu;
354
355 if (net->ipv6.devconf_all->forwarding == 0)
356 goto error;
357
358 if (skb_warn_if_lro(skb))
359 goto drop;
360
361 if (!xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) {
362 IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS);
363 goto drop;
364 }
365
366 if (skb->pkt_type != PACKET_HOST)
367 goto drop;
368
369 skb_forward_csum(skb);
370
371 /*
372 * We DO NOT make any processing on
373 * RA packets, pushing them to user level AS IS
374 * without ane WARRANTY that application will be able
375 * to interpret them. The reason is that we
376 * cannot make anything clever here.
377 *
378 * We are not end-node, so that if packet contains
379 * AH/ESP, we cannot make anything.
380 * Defragmentation also would be mistake, RA packets
381 * cannot be fragmented, because there is no warranty
382 * that different fragments will go along one path. --ANK
383 */
384 if (unlikely(opt->flags & IP6SKB_ROUTERALERT)) {
385 if (ip6_call_ra_chain(skb, ntohs(opt->ra)))
386 return 0;
387 }
388
389 /*
390 * check and decrement ttl
391 */
392 if (hdr->hop_limit <= 1) {
393 /* Force OUTPUT device used as source address */
394 skb->dev = dst->dev;
395 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 0);
396 IP6_INC_STATS_BH(net,
397 ip6_dst_idev(dst), IPSTATS_MIB_INHDRERRORS);
398
399 kfree_skb(skb);
400 return -ETIMEDOUT;
401 }
402
403 /* XXX: idev->cnf.proxy_ndp? */
404 if (net->ipv6.devconf_all->proxy_ndp &&
405 pneigh_lookup(&nd_tbl, net, &hdr->daddr, skb->dev, 0)) {
406 int proxied = ip6_forward_proxy_check(skb);
407 if (proxied > 0)
408 return ip6_input(skb);
409 else if (proxied < 0) {
410 IP6_INC_STATS(net, ip6_dst_idev(dst),
411 IPSTATS_MIB_INDISCARDS);
412 goto drop;
413 }
414 }
415
416 if (!xfrm6_route_forward(skb)) {
417 IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS);
418 goto drop;
419 }
420 dst = skb_dst(skb);
421
422 /* IPv6 specs say nothing about it, but it is clear that we cannot
423 send redirects to source routed frames.
424 We don't send redirects to frames decapsulated from IPsec.
425 */
426 if (skb->dev == dst->dev && opt->srcrt == 0 && !skb_sec_path(skb)) {
427 struct in6_addr *target = NULL;
428 struct inet_peer *peer;
429 struct rt6_info *rt;
430
431 /*
432 * incoming and outgoing devices are the same
433 * send a redirect.
434 */
435
436 rt = (struct rt6_info *) dst;
437 if (rt->rt6i_flags & RTF_GATEWAY)
438 target = &rt->rt6i_gateway;
439 else
440 target = &hdr->daddr;
441
442 peer = inet_getpeer_v6(net->ipv6.peers, &rt->rt6i_dst.addr, 1);
443
444 /* Limit redirects both by destination (here)
445 and by source (inside ndisc_send_redirect)
446 */
447 if (inet_peer_xrlim_allow(peer, 1*HZ))
448 ndisc_send_redirect(skb, target);
449 if (peer)
450 inet_putpeer(peer);
451 } else {
452 int addrtype = ipv6_addr_type(&hdr->saddr);
453
454 /* This check is security critical. */
455 if (addrtype == IPV6_ADDR_ANY ||
456 addrtype & (IPV6_ADDR_MULTICAST | IPV6_ADDR_LOOPBACK))
457 goto error;
458 if (addrtype & IPV6_ADDR_LINKLOCAL) {
459 icmpv6_send(skb, ICMPV6_DEST_UNREACH,
460 ICMPV6_NOT_NEIGHBOUR, 0);
461 goto error;
462 }
463 }
464
465 mtu = dst_mtu(dst);
466 if (mtu < IPV6_MIN_MTU)
467 mtu = IPV6_MIN_MTU;
468
469 if ((!skb->local_df && skb->len > mtu && !skb_is_gso(skb)) ||
470 (IP6CB(skb)->frag_max_size && IP6CB(skb)->frag_max_size > mtu)) {
471 /* Again, force OUTPUT device used as source address */
472 skb->dev = dst->dev;
473 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
474 IP6_INC_STATS_BH(net,
475 ip6_dst_idev(dst), IPSTATS_MIB_INTOOBIGERRORS);
476 IP6_INC_STATS_BH(net,
477 ip6_dst_idev(dst), IPSTATS_MIB_FRAGFAILS);
478 kfree_skb(skb);
479 return -EMSGSIZE;
480 }
481
482 if (skb_cow(skb, dst->dev->hard_header_len)) {
483 IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTDISCARDS);
484 goto drop;
485 }
486
487 hdr = ipv6_hdr(skb);
488
489 /* Mangling hops number delayed to point after skb COW */
490
491 hdr->hop_limit--;
492
493 IP6_INC_STATS_BH(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTFORWDATAGRAMS);
494 IP6_ADD_STATS_BH(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTOCTETS, skb->len);
495 return NF_HOOK(NFPROTO_IPV6, NF_INET_FORWARD, skb, skb->dev, dst->dev,
496 ip6_forward_finish);
497
498 error:
499 IP6_INC_STATS_BH(net, ip6_dst_idev(dst), IPSTATS_MIB_INADDRERRORS);
500 drop:
501 kfree_skb(skb);
502 return -EINVAL;
503 }
504
505 static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from)
506 {
507 to->pkt_type = from->pkt_type;
508 to->priority = from->priority;
509 to->protocol = from->protocol;
510 skb_dst_drop(to);
511 skb_dst_set(to, dst_clone(skb_dst(from)));
512 to->dev = from->dev;
513 to->mark = from->mark;
514
515 #ifdef CONFIG_NET_SCHED
516 to->tc_index = from->tc_index;
517 #endif
518 nf_copy(to, from);
519 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE)
520 to->nf_trace = from->nf_trace;
521 #endif
522 skb_copy_secmark(to, from);
523 }
524
525 int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *))
526 {
527 struct sk_buff *frag;
528 struct rt6_info *rt = (struct rt6_info*)skb_dst(skb);
529 struct ipv6_pinfo *np = skb->sk ? inet6_sk(skb->sk) : NULL;
530 struct ipv6hdr *tmp_hdr;
531 struct frag_hdr *fh;
532 unsigned int mtu, hlen, left, len;
533 int hroom, troom;
534 __be32 frag_id = 0;
535 int ptr, offset = 0, err=0;
536 u8 *prevhdr, nexthdr = 0;
537 struct net *net = dev_net(skb_dst(skb)->dev);
538
539 hlen = ip6_find_1stfragopt(skb, &prevhdr);
540 nexthdr = *prevhdr;
541
542 mtu = ip6_skb_dst_mtu(skb);
543
544 /* We must not fragment if the socket is set to force MTU discovery
545 * or if the skb it not generated by a local socket.
546 */
547 if (unlikely(!skb->local_df && skb->len > mtu) ||
548 (IP6CB(skb)->frag_max_size &&
549 IP6CB(skb)->frag_max_size > mtu)) {
550 if (skb->sk && dst_allfrag(skb_dst(skb)))
551 sk_nocaps_add(skb->sk, NETIF_F_GSO_MASK);
552
553 skb->dev = skb_dst(skb)->dev;
554 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
555 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
556 IPSTATS_MIB_FRAGFAILS);
557 kfree_skb(skb);
558 return -EMSGSIZE;
559 }
560
561 if (np && np->frag_size < mtu) {
562 if (np->frag_size)
563 mtu = np->frag_size;
564 }
565 mtu -= hlen + sizeof(struct frag_hdr);
566
567 if (skb_has_frag_list(skb)) {
568 int first_len = skb_pagelen(skb);
569 struct sk_buff *frag2;
570
571 if (first_len - hlen > mtu ||
572 ((first_len - hlen) & 7) ||
573 skb_cloned(skb))
574 goto slow_path;
575
576 skb_walk_frags(skb, frag) {
577 /* Correct geometry. */
578 if (frag->len > mtu ||
579 ((frag->len & 7) && frag->next) ||
580 skb_headroom(frag) < hlen)
581 goto slow_path_clean;
582
583 /* Partially cloned skb? */
584 if (skb_shared(frag))
585 goto slow_path_clean;
586
587 BUG_ON(frag->sk);
588 if (skb->sk) {
589 frag->sk = skb->sk;
590 frag->destructor = sock_wfree;
591 }
592 skb->truesize -= frag->truesize;
593 }
594
595 err = 0;
596 offset = 0;
597 frag = skb_shinfo(skb)->frag_list;
598 skb_frag_list_init(skb);
599 /* BUILD HEADER */
600
601 *prevhdr = NEXTHDR_FRAGMENT;
602 tmp_hdr = kmemdup(skb_network_header(skb), hlen, GFP_ATOMIC);
603 if (!tmp_hdr) {
604 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
605 IPSTATS_MIB_FRAGFAILS);
606 return -ENOMEM;
607 }
608
609 __skb_pull(skb, hlen);
610 fh = (struct frag_hdr*)__skb_push(skb, sizeof(struct frag_hdr));
611 __skb_push(skb, hlen);
612 skb_reset_network_header(skb);
613 memcpy(skb_network_header(skb), tmp_hdr, hlen);
614
615 ipv6_select_ident(fh, rt);
616 fh->nexthdr = nexthdr;
617 fh->reserved = 0;
618 fh->frag_off = htons(IP6_MF);
619 frag_id = fh->identification;
620
621 first_len = skb_pagelen(skb);
622 skb->data_len = first_len - skb_headlen(skb);
623 skb->len = first_len;
624 ipv6_hdr(skb)->payload_len = htons(first_len -
625 sizeof(struct ipv6hdr));
626
627 dst_hold(&rt->dst);
628
629 for (;;) {
630 /* Prepare header of the next frame,
631 * before previous one went down. */
632 if (frag) {
633 frag->ip_summed = CHECKSUM_NONE;
634 skb_reset_transport_header(frag);
635 fh = (struct frag_hdr*)__skb_push(frag, sizeof(struct frag_hdr));
636 __skb_push(frag, hlen);
637 skb_reset_network_header(frag);
638 memcpy(skb_network_header(frag), tmp_hdr,
639 hlen);
640 offset += skb->len - hlen - sizeof(struct frag_hdr);
641 fh->nexthdr = nexthdr;
642 fh->reserved = 0;
643 fh->frag_off = htons(offset);
644 if (frag->next != NULL)
645 fh->frag_off |= htons(IP6_MF);
646 fh->identification = frag_id;
647 ipv6_hdr(frag)->payload_len =
648 htons(frag->len -
649 sizeof(struct ipv6hdr));
650 ip6_copy_metadata(frag, skb);
651 }
652
653 err = output(skb);
654 if(!err)
655 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
656 IPSTATS_MIB_FRAGCREATES);
657
658 if (err || !frag)
659 break;
660
661 skb = frag;
662 frag = skb->next;
663 skb->next = NULL;
664 }
665
666 kfree(tmp_hdr);
667
668 if (err == 0) {
669 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
670 IPSTATS_MIB_FRAGOKS);
671 ip6_rt_put(rt);
672 return 0;
673 }
674
675 while (frag) {
676 skb = frag->next;
677 kfree_skb(frag);
678 frag = skb;
679 }
680
681 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
682 IPSTATS_MIB_FRAGFAILS);
683 ip6_rt_put(rt);
684 return err;
685
686 slow_path_clean:
687 skb_walk_frags(skb, frag2) {
688 if (frag2 == frag)
689 break;
690 frag2->sk = NULL;
691 frag2->destructor = NULL;
692 skb->truesize += frag2->truesize;
693 }
694 }
695
696 slow_path:
697 if ((skb->ip_summed == CHECKSUM_PARTIAL) &&
698 skb_checksum_help(skb))
699 goto fail;
700
701 left = skb->len - hlen; /* Space per frame */
702 ptr = hlen; /* Where to start from */
703
704 /*
705 * Fragment the datagram.
706 */
707
708 *prevhdr = NEXTHDR_FRAGMENT;
709 hroom = LL_RESERVED_SPACE(rt->dst.dev);
710 troom = rt->dst.dev->needed_tailroom;
711
712 /*
713 * Keep copying data until we run out.
714 */
715 while(left > 0) {
716 len = left;
717 /* IF: it doesn't fit, use 'mtu' - the data space left */
718 if (len > mtu)
719 len = mtu;
720 /* IF: we are not sending up to and including the packet end
721 then align the next start on an eight byte boundary */
722 if (len < left) {
723 len &= ~7;
724 }
725 /*
726 * Allocate buffer.
727 */
728
729 if ((frag = alloc_skb(len + hlen + sizeof(struct frag_hdr) +
730 hroom + troom, GFP_ATOMIC)) == NULL) {
731 NETDEBUG(KERN_INFO "IPv6: frag: no memory for new fragment!\n");
732 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
733 IPSTATS_MIB_FRAGFAILS);
734 err = -ENOMEM;
735 goto fail;
736 }
737
738 /*
739 * Set up data on packet
740 */
741
742 ip6_copy_metadata(frag, skb);
743 skb_reserve(frag, hroom);
744 skb_put(frag, len + hlen + sizeof(struct frag_hdr));
745 skb_reset_network_header(frag);
746 fh = (struct frag_hdr *)(skb_network_header(frag) + hlen);
747 frag->transport_header = (frag->network_header + hlen +
748 sizeof(struct frag_hdr));
749
750 /*
751 * Charge the memory for the fragment to any owner
752 * it might possess
753 */
754 if (skb->sk)
755 skb_set_owner_w(frag, skb->sk);
756
757 /*
758 * Copy the packet header into the new buffer.
759 */
760 skb_copy_from_linear_data(skb, skb_network_header(frag), hlen);
761
762 /*
763 * Build fragment header.
764 */
765 fh->nexthdr = nexthdr;
766 fh->reserved = 0;
767 if (!frag_id) {
768 ipv6_select_ident(fh, rt);
769 frag_id = fh->identification;
770 } else
771 fh->identification = frag_id;
772
773 /*
774 * Copy a block of the IP datagram.
775 */
776 if (skb_copy_bits(skb, ptr, skb_transport_header(frag), len))
777 BUG();
778 left -= len;
779
780 fh->frag_off = htons(offset);
781 if (left > 0)
782 fh->frag_off |= htons(IP6_MF);
783 ipv6_hdr(frag)->payload_len = htons(frag->len -
784 sizeof(struct ipv6hdr));
785
786 ptr += len;
787 offset += len;
788
789 /*
790 * Put this fragment into the sending queue.
791 */
792 err = output(frag);
793 if (err)
794 goto fail;
795
796 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
797 IPSTATS_MIB_FRAGCREATES);
798 }
799 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
800 IPSTATS_MIB_FRAGOKS);
801 consume_skb(skb);
802 return err;
803
804 fail:
805 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
806 IPSTATS_MIB_FRAGFAILS);
807 kfree_skb(skb);
808 return err;
809 }
810
811 static inline int ip6_rt_check(const struct rt6key *rt_key,
812 const struct in6_addr *fl_addr,
813 const struct in6_addr *addr_cache)
814 {
815 return (rt_key->plen != 128 || !ipv6_addr_equal(fl_addr, &rt_key->addr)) &&
816 (addr_cache == NULL || !ipv6_addr_equal(fl_addr, addr_cache));
817 }
818
819 static struct dst_entry *ip6_sk_dst_check(struct sock *sk,
820 struct dst_entry *dst,
821 const struct flowi6 *fl6)
822 {
823 struct ipv6_pinfo *np = inet6_sk(sk);
824 struct rt6_info *rt;
825
826 if (!dst)
827 goto out;
828
829 if (dst->ops->family != AF_INET6) {
830 dst_release(dst);
831 return NULL;
832 }
833
834 rt = (struct rt6_info *)dst;
835 /* Yes, checking route validity in not connected
836 * case is not very simple. Take into account,
837 * that we do not support routing by source, TOS,
838 * and MSG_DONTROUTE --ANK (980726)
839 *
840 * 1. ip6_rt_check(): If route was host route,
841 * check that cached destination is current.
842 * If it is network route, we still may
843 * check its validity using saved pointer
844 * to the last used address: daddr_cache.
845 * We do not want to save whole address now,
846 * (because main consumer of this service
847 * is tcp, which has not this problem),
848 * so that the last trick works only on connected
849 * sockets.
850 * 2. oif also should be the same.
851 */
852 if (ip6_rt_check(&rt->rt6i_dst, &fl6->daddr, np->daddr_cache) ||
853 #ifdef CONFIG_IPV6_SUBTREES
854 ip6_rt_check(&rt->rt6i_src, &fl6->saddr, np->saddr_cache) ||
855 #endif
856 (fl6->flowi6_oif && fl6->flowi6_oif != dst->dev->ifindex)) {
857 dst_release(dst);
858 dst = NULL;
859 }
860
861 out:
862 return dst;
863 }
864
865 static int ip6_dst_lookup_tail(struct sock *sk,
866 struct dst_entry **dst, struct flowi6 *fl6)
867 {
868 struct net *net = sock_net(sk);
869 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
870 struct neighbour *n;
871 struct rt6_info *rt;
872 #endif
873 int err;
874
875 if (*dst == NULL)
876 *dst = ip6_route_output(net, sk, fl6);
877
878 if ((err = (*dst)->error))
879 goto out_err_release;
880
881 if (ipv6_addr_any(&fl6->saddr)) {
882 struct rt6_info *rt = (struct rt6_info *) *dst;
883 err = ip6_route_get_saddr(net, rt, &fl6->daddr,
884 sk ? inet6_sk(sk)->srcprefs : 0,
885 &fl6->saddr);
886 if (err)
887 goto out_err_release;
888 }
889
890 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
891 /*
892 * Here if the dst entry we've looked up
893 * has a neighbour entry that is in the INCOMPLETE
894 * state and the src address from the flow is
895 * marked as OPTIMISTIC, we release the found
896 * dst entry and replace it instead with the
897 * dst entry of the nexthop router
898 */
899 rt = (struct rt6_info *) *dst;
900 rcu_read_lock_bh();
901 n = __ipv6_neigh_lookup_noref(rt->dst.dev, rt6_nexthop(rt, &fl6->daddr));
902 err = n && !(n->nud_state & NUD_VALID) ? -EINVAL : 0;
903 rcu_read_unlock_bh();
904
905 if (err) {
906 struct inet6_ifaddr *ifp;
907 struct flowi6 fl_gw6;
908 int redirect;
909
910 ifp = ipv6_get_ifaddr(net, &fl6->saddr,
911 (*dst)->dev, 1);
912
913 redirect = (ifp && ifp->flags & IFA_F_OPTIMISTIC);
914 if (ifp)
915 in6_ifa_put(ifp);
916
917 if (redirect) {
918 /*
919 * We need to get the dst entry for the
920 * default router instead
921 */
922 dst_release(*dst);
923 memcpy(&fl_gw6, fl6, sizeof(struct flowi6));
924 memset(&fl_gw6.daddr, 0, sizeof(struct in6_addr));
925 *dst = ip6_route_output(net, sk, &fl_gw6);
926 if ((err = (*dst)->error))
927 goto out_err_release;
928 }
929 }
930 #endif
931
932 return 0;
933
934 out_err_release:
935 if (err == -ENETUNREACH)
936 IP6_INC_STATS_BH(net, NULL, IPSTATS_MIB_OUTNOROUTES);
937 dst_release(*dst);
938 *dst = NULL;
939 return err;
940 }
941
942 /**
943 * ip6_dst_lookup - perform route lookup on flow
944 * @sk: socket which provides route info
945 * @dst: pointer to dst_entry * for result
946 * @fl6: flow to lookup
947 *
948 * This function performs a route lookup on the given flow.
949 *
950 * It returns zero on success, or a standard errno code on error.
951 */
952 int ip6_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi6 *fl6)
953 {
954 *dst = NULL;
955 return ip6_dst_lookup_tail(sk, dst, fl6);
956 }
957 EXPORT_SYMBOL_GPL(ip6_dst_lookup);
958
959 /**
960 * ip6_dst_lookup_flow - perform route lookup on flow with ipsec
961 * @sk: socket which provides route info
962 * @fl6: flow to lookup
963 * @final_dst: final destination address for ipsec lookup
964 * @can_sleep: we are in a sleepable context
965 *
966 * This function performs a route lookup on the given flow.
967 *
968 * It returns a valid dst pointer on success, or a pointer encoded
969 * error code.
970 */
971 struct dst_entry *ip6_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
972 const struct in6_addr *final_dst,
973 bool can_sleep)
974 {
975 struct dst_entry *dst = NULL;
976 int err;
977
978 err = ip6_dst_lookup_tail(sk, &dst, fl6);
979 if (err)
980 return ERR_PTR(err);
981 if (final_dst)
982 fl6->daddr = *final_dst;
983 if (can_sleep)
984 fl6->flowi6_flags |= FLOWI_FLAG_CAN_SLEEP;
985
986 return xfrm_lookup(sock_net(sk), dst, flowi6_to_flowi(fl6), sk, 0);
987 }
988 EXPORT_SYMBOL_GPL(ip6_dst_lookup_flow);
989
990 /**
991 * ip6_sk_dst_lookup_flow - perform socket cached route lookup on flow
992 * @sk: socket which provides the dst cache and route info
993 * @fl6: flow to lookup
994 * @final_dst: final destination address for ipsec lookup
995 * @can_sleep: we are in a sleepable context
996 *
997 * This function performs a route lookup on the given flow with the
998 * possibility of using the cached route in the socket if it is valid.
999 * It will take the socket dst lock when operating on the dst cache.
1000 * As a result, this function can only be used in process context.
1001 *
1002 * It returns a valid dst pointer on success, or a pointer encoded
1003 * error code.
1004 */
1005 struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
1006 const struct in6_addr *final_dst,
1007 bool can_sleep)
1008 {
1009 struct dst_entry *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie);
1010 int err;
1011
1012 dst = ip6_sk_dst_check(sk, dst, fl6);
1013
1014 err = ip6_dst_lookup_tail(sk, &dst, fl6);
1015 if (err)
1016 return ERR_PTR(err);
1017 if (final_dst)
1018 fl6->daddr = *final_dst;
1019 if (can_sleep)
1020 fl6->flowi6_flags |= FLOWI_FLAG_CAN_SLEEP;
1021
1022 return xfrm_lookup(sock_net(sk), dst, flowi6_to_flowi(fl6), sk, 0);
1023 }
1024 EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup_flow);
1025
1026 static inline int ip6_ufo_append_data(struct sock *sk,
1027 int getfrag(void *from, char *to, int offset, int len,
1028 int odd, struct sk_buff *skb),
1029 void *from, int length, int hh_len, int fragheaderlen,
1030 int transhdrlen, int mtu,unsigned int flags,
1031 struct rt6_info *rt)
1032
1033 {
1034 struct sk_buff *skb;
1035 int err;
1036
1037 /* There is support for UDP large send offload by network
1038 * device, so create one single skb packet containing complete
1039 * udp datagram
1040 */
1041 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) {
1042 skb = sock_alloc_send_skb(sk,
1043 hh_len + fragheaderlen + transhdrlen + 20,
1044 (flags & MSG_DONTWAIT), &err);
1045 if (skb == NULL)
1046 return err;
1047
1048 /* reserve space for Hardware header */
1049 skb_reserve(skb, hh_len);
1050
1051 /* create space for UDP/IP header */
1052 skb_put(skb,fragheaderlen + transhdrlen);
1053
1054 /* initialize network header pointer */
1055 skb_reset_network_header(skb);
1056
1057 /* initialize protocol header pointer */
1058 skb->transport_header = skb->network_header + fragheaderlen;
1059
1060 skb->ip_summed = CHECKSUM_PARTIAL;
1061 skb->csum = 0;
1062 }
1063
1064 err = skb_append_datato_frags(sk,skb, getfrag, from,
1065 (length - transhdrlen));
1066 if (!err) {
1067 struct frag_hdr fhdr;
1068
1069 /* Specify the length of each IPv6 datagram fragment.
1070 * It has to be a multiple of 8.
1071 */
1072 skb_shinfo(skb)->gso_size = (mtu - fragheaderlen -
1073 sizeof(struct frag_hdr)) & ~7;
1074 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
1075 ipv6_select_ident(&fhdr, rt);
1076 skb_shinfo(skb)->ip6_frag_id = fhdr.identification;
1077 __skb_queue_tail(&sk->sk_write_queue, skb);
1078
1079 return 0;
1080 }
1081 /* There is not enough support do UPD LSO,
1082 * so follow normal path
1083 */
1084 kfree_skb(skb);
1085
1086 return err;
1087 }
1088
1089 static inline struct ipv6_opt_hdr *ip6_opt_dup(struct ipv6_opt_hdr *src,
1090 gfp_t gfp)
1091 {
1092 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL;
1093 }
1094
1095 static inline struct ipv6_rt_hdr *ip6_rthdr_dup(struct ipv6_rt_hdr *src,
1096 gfp_t gfp)
1097 {
1098 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL;
1099 }
1100
1101 static void ip6_append_data_mtu(int *mtu,
1102 int *maxfraglen,
1103 unsigned int fragheaderlen,
1104 struct sk_buff *skb,
1105 struct rt6_info *rt)
1106 {
1107 if (!(rt->dst.flags & DST_XFRM_TUNNEL)) {
1108 if (skb == NULL) {
1109 /* first fragment, reserve header_len */
1110 *mtu = *mtu - rt->dst.header_len;
1111
1112 } else {
1113 /*
1114 * this fragment is not first, the headers
1115 * space is regarded as data space.
1116 */
1117 *mtu = dst_mtu(rt->dst.path);
1118 }
1119 *maxfraglen = ((*mtu - fragheaderlen) & ~7)
1120 + fragheaderlen - sizeof(struct frag_hdr);
1121 }
1122 }
1123
1124 int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
1125 int offset, int len, int odd, struct sk_buff *skb),
1126 void *from, int length, int transhdrlen,
1127 int hlimit, int tclass, struct ipv6_txoptions *opt, struct flowi6 *fl6,
1128 struct rt6_info *rt, unsigned int flags, int dontfrag)
1129 {
1130 struct inet_sock *inet = inet_sk(sk);
1131 struct ipv6_pinfo *np = inet6_sk(sk);
1132 struct inet_cork *cork;
1133 struct sk_buff *skb, *skb_prev = NULL;
1134 unsigned int maxfraglen, fragheaderlen;
1135 int exthdrlen;
1136 int dst_exthdrlen;
1137 int hh_len;
1138 int mtu;
1139 int copy;
1140 int err;
1141 int offset = 0;
1142 __u8 tx_flags = 0;
1143
1144 if (flags&MSG_PROBE)
1145 return 0;
1146 cork = &inet->cork.base;
1147 if (skb_queue_empty(&sk->sk_write_queue)) {
1148 /*
1149 * setup for corking
1150 */
1151 if (opt) {
1152 if (WARN_ON(np->cork.opt))
1153 return -EINVAL;
1154
1155 np->cork.opt = kzalloc(opt->tot_len, sk->sk_allocation);
1156 if (unlikely(np->cork.opt == NULL))
1157 return -ENOBUFS;
1158
1159 np->cork.opt->tot_len = opt->tot_len;
1160 np->cork.opt->opt_flen = opt->opt_flen;
1161 np->cork.opt->opt_nflen = opt->opt_nflen;
1162
1163 np->cork.opt->dst0opt = ip6_opt_dup(opt->dst0opt,
1164 sk->sk_allocation);
1165 if (opt->dst0opt && !np->cork.opt->dst0opt)
1166 return -ENOBUFS;
1167
1168 np->cork.opt->dst1opt = ip6_opt_dup(opt->dst1opt,
1169 sk->sk_allocation);
1170 if (opt->dst1opt && !np->cork.opt->dst1opt)
1171 return -ENOBUFS;
1172
1173 np->cork.opt->hopopt = ip6_opt_dup(opt->hopopt,
1174 sk->sk_allocation);
1175 if (opt->hopopt && !np->cork.opt->hopopt)
1176 return -ENOBUFS;
1177
1178 np->cork.opt->srcrt = ip6_rthdr_dup(opt->srcrt,
1179 sk->sk_allocation);
1180 if (opt->srcrt && !np->cork.opt->srcrt)
1181 return -ENOBUFS;
1182
1183 /* need source address above miyazawa*/
1184 }
1185 dst_hold(&rt->dst);
1186 cork->dst = &rt->dst;
1187 inet->cork.fl.u.ip6 = *fl6;
1188 np->cork.hop_limit = hlimit;
1189 np->cork.tclass = tclass;
1190 if (rt->dst.flags & DST_XFRM_TUNNEL)
1191 mtu = np->pmtudisc == IPV6_PMTUDISC_PROBE ?
1192 rt->dst.dev->mtu : dst_mtu(&rt->dst);
1193 else
1194 mtu = np->pmtudisc == IPV6_PMTUDISC_PROBE ?
1195 rt->dst.dev->mtu : dst_mtu(rt->dst.path);
1196 if (np->frag_size < mtu) {
1197 if (np->frag_size)
1198 mtu = np->frag_size;
1199 }
1200 cork->fragsize = mtu;
1201 if (dst_allfrag(rt->dst.path))
1202 cork->flags |= IPCORK_ALLFRAG;
1203 cork->length = 0;
1204 exthdrlen = (opt ? opt->opt_flen : 0);
1205 length += exthdrlen;
1206 transhdrlen += exthdrlen;
1207 dst_exthdrlen = rt->dst.header_len - rt->rt6i_nfheader_len;
1208 } else {
1209 rt = (struct rt6_info *)cork->dst;
1210 fl6 = &inet->cork.fl.u.ip6;
1211 opt = np->cork.opt;
1212 transhdrlen = 0;
1213 exthdrlen = 0;
1214 dst_exthdrlen = 0;
1215 mtu = cork->fragsize;
1216 }
1217
1218 hh_len = LL_RESERVED_SPACE(rt->dst.dev);
1219
1220 fragheaderlen = sizeof(struct ipv6hdr) + rt->rt6i_nfheader_len +
1221 (opt ? opt->opt_nflen : 0);
1222 maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - sizeof(struct frag_hdr);
1223
1224 if (mtu <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN) {
1225 if (cork->length + length > sizeof(struct ipv6hdr) + IPV6_MAXPLEN - fragheaderlen) {
1226 ipv6_local_error(sk, EMSGSIZE, fl6, mtu-exthdrlen);
1227 return -EMSGSIZE;
1228 }
1229 }
1230
1231 /* For UDP, check if TX timestamp is enabled */
1232 if (sk->sk_type == SOCK_DGRAM)
1233 sock_tx_timestamp(sk, &tx_flags);
1234
1235 /*
1236 * Let's try using as much space as possible.
1237 * Use MTU if total length of the message fits into the MTU.
1238 * Otherwise, we need to reserve fragment header and
1239 * fragment alignment (= 8-15 octects, in total).
1240 *
1241 * Note that we may need to "move" the data from the tail of
1242 * of the buffer to the new fragment when we split
1243 * the message.
1244 *
1245 * FIXME: It may be fragmented into multiple chunks
1246 * at once if non-fragmentable extension headers
1247 * are too large.
1248 * --yoshfuji
1249 */
1250
1251 cork->length += length;
1252 if (length > mtu) {
1253 int proto = sk->sk_protocol;
1254 if (dontfrag && (proto == IPPROTO_UDP || proto == IPPROTO_RAW)){
1255 ipv6_local_rxpmtu(sk, fl6, mtu-exthdrlen);
1256 return -EMSGSIZE;
1257 }
1258
1259 if (proto == IPPROTO_UDP &&
1260 (rt->dst.dev->features & NETIF_F_UFO)) {
1261
1262 err = ip6_ufo_append_data(sk, getfrag, from, length,
1263 hh_len, fragheaderlen,
1264 transhdrlen, mtu, flags, rt);
1265 if (err)
1266 goto error;
1267 return 0;
1268 }
1269 }
1270
1271 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL)
1272 goto alloc_new_skb;
1273
1274 while (length > 0) {
1275 /* Check if the remaining data fits into current packet. */
1276 copy = (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len;
1277 if (copy < length)
1278 copy = maxfraglen - skb->len;
1279
1280 if (copy <= 0) {
1281 char *data;
1282 unsigned int datalen;
1283 unsigned int fraglen;
1284 unsigned int fraggap;
1285 unsigned int alloclen;
1286 alloc_new_skb:
1287 /* There's no room in the current skb */
1288 if (skb)
1289 fraggap = skb->len - maxfraglen;
1290 else
1291 fraggap = 0;
1292 /* update mtu and maxfraglen if necessary */
1293 if (skb == NULL || skb_prev == NULL)
1294 ip6_append_data_mtu(&mtu, &maxfraglen,
1295 fragheaderlen, skb, rt);
1296
1297 skb_prev = skb;
1298
1299 /*
1300 * If remaining data exceeds the mtu,
1301 * we know we need more fragment(s).
1302 */
1303 datalen = length + fraggap;
1304
1305 if (datalen > (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen)
1306 datalen = maxfraglen - fragheaderlen - rt->dst.trailer_len;
1307 if ((flags & MSG_MORE) &&
1308 !(rt->dst.dev->features&NETIF_F_SG))
1309 alloclen = mtu;
1310 else
1311 alloclen = datalen + fragheaderlen;
1312
1313 alloclen += dst_exthdrlen;
1314
1315 if (datalen != length + fraggap) {
1316 /*
1317 * this is not the last fragment, the trailer
1318 * space is regarded as data space.
1319 */
1320 datalen += rt->dst.trailer_len;
1321 }
1322
1323 alloclen += rt->dst.trailer_len;
1324 fraglen = datalen + fragheaderlen;
1325
1326 /*
1327 * We just reserve space for fragment header.
1328 * Note: this may be overallocation if the message
1329 * (without MSG_MORE) fits into the MTU.
1330 */
1331 alloclen += sizeof(struct frag_hdr);
1332
1333 if (transhdrlen) {
1334 skb = sock_alloc_send_skb(sk,
1335 alloclen + hh_len,
1336 (flags & MSG_DONTWAIT), &err);
1337 } else {
1338 skb = NULL;
1339 if (atomic_read(&sk->sk_wmem_alloc) <=
1340 2 * sk->sk_sndbuf)
1341 skb = sock_wmalloc(sk,
1342 alloclen + hh_len, 1,
1343 sk->sk_allocation);
1344 if (unlikely(skb == NULL))
1345 err = -ENOBUFS;
1346 else {
1347 /* Only the initial fragment
1348 * is time stamped.
1349 */
1350 tx_flags = 0;
1351 }
1352 }
1353 if (skb == NULL)
1354 goto error;
1355 /*
1356 * Fill in the control structures
1357 */
1358 skb->ip_summed = CHECKSUM_NONE;
1359 skb->csum = 0;
1360 /* reserve for fragmentation and ipsec header */
1361 skb_reserve(skb, hh_len + sizeof(struct frag_hdr) +
1362 dst_exthdrlen);
1363
1364 if (sk->sk_type == SOCK_DGRAM)
1365 skb_shinfo(skb)->tx_flags = tx_flags;
1366
1367 /*
1368 * Find where to start putting bytes
1369 */
1370 data = skb_put(skb, fraglen);
1371 skb_set_network_header(skb, exthdrlen);
1372 data += fragheaderlen;
1373 skb->transport_header = (skb->network_header +
1374 fragheaderlen);
1375 if (fraggap) {
1376 skb->csum = skb_copy_and_csum_bits(
1377 skb_prev, maxfraglen,
1378 data + transhdrlen, fraggap, 0);
1379 skb_prev->csum = csum_sub(skb_prev->csum,
1380 skb->csum);
1381 data += fraggap;
1382 pskb_trim_unique(skb_prev, maxfraglen);
1383 }
1384 copy = datalen - transhdrlen - fraggap;
1385
1386 if (copy < 0) {
1387 err = -EINVAL;
1388 kfree_skb(skb);
1389 goto error;
1390 } else if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) {
1391 err = -EFAULT;
1392 kfree_skb(skb);
1393 goto error;
1394 }
1395
1396 offset += copy;
1397 length -= datalen - fraggap;
1398 transhdrlen = 0;
1399 exthdrlen = 0;
1400 dst_exthdrlen = 0;
1401
1402 /*
1403 * Put the packet on the pending queue
1404 */
1405 __skb_queue_tail(&sk->sk_write_queue, skb);
1406 continue;
1407 }
1408
1409 if (copy > length)
1410 copy = length;
1411
1412 if (!(rt->dst.dev->features&NETIF_F_SG)) {
1413 unsigned int off;
1414
1415 off = skb->len;
1416 if (getfrag(from, skb_put(skb, copy),
1417 offset, copy, off, skb) < 0) {
1418 __skb_trim(skb, off);
1419 err = -EFAULT;
1420 goto error;
1421 }
1422 } else {
1423 int i = skb_shinfo(skb)->nr_frags;
1424 struct page_frag *pfrag = sk_page_frag(sk);
1425
1426 err = -ENOMEM;
1427 if (!sk_page_frag_refill(sk, pfrag))
1428 goto error;
1429
1430 if (!skb_can_coalesce(skb, i, pfrag->page,
1431 pfrag->offset)) {
1432 err = -EMSGSIZE;
1433 if (i == MAX_SKB_FRAGS)
1434 goto error;
1435
1436 __skb_fill_page_desc(skb, i, pfrag->page,
1437 pfrag->offset, 0);
1438 skb_shinfo(skb)->nr_frags = ++i;
1439 get_page(pfrag->page);
1440 }
1441 copy = min_t(int, copy, pfrag->size - pfrag->offset);
1442 if (getfrag(from,
1443 page_address(pfrag->page) + pfrag->offset,
1444 offset, copy, skb->len, skb) < 0)
1445 goto error_efault;
1446
1447 pfrag->offset += copy;
1448 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
1449 skb->len += copy;
1450 skb->data_len += copy;
1451 skb->truesize += copy;
1452 atomic_add(copy, &sk->sk_wmem_alloc);
1453 }
1454 offset += copy;
1455 length -= copy;
1456 }
1457
1458 return 0;
1459
1460 error_efault:
1461 err = -EFAULT;
1462 error:
1463 cork->length -= length;
1464 IP6_INC_STATS(sock_net(sk), rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS);
1465 return err;
1466 }
1467 EXPORT_SYMBOL_GPL(ip6_append_data);
1468
1469 static void ip6_cork_release(struct inet_sock *inet, struct ipv6_pinfo *np)
1470 {
1471 if (np->cork.opt) {
1472 kfree(np->cork.opt->dst0opt);
1473 kfree(np->cork.opt->dst1opt);
1474 kfree(np->cork.opt->hopopt);
1475 kfree(np->cork.opt->srcrt);
1476 kfree(np->cork.opt);
1477 np->cork.opt = NULL;
1478 }
1479
1480 if (inet->cork.base.dst) {
1481 dst_release(inet->cork.base.dst);
1482 inet->cork.base.dst = NULL;
1483 inet->cork.base.flags &= ~IPCORK_ALLFRAG;
1484 }
1485 memset(&inet->cork.fl, 0, sizeof(inet->cork.fl));
1486 }
1487
1488 int ip6_push_pending_frames(struct sock *sk)
1489 {
1490 struct sk_buff *skb, *tmp_skb;
1491 struct sk_buff **tail_skb;
1492 struct in6_addr final_dst_buf, *final_dst = &final_dst_buf;
1493 struct inet_sock *inet = inet_sk(sk);
1494 struct ipv6_pinfo *np = inet6_sk(sk);
1495 struct net *net = sock_net(sk);
1496 struct ipv6hdr *hdr;
1497 struct ipv6_txoptions *opt = np->cork.opt;
1498 struct rt6_info *rt = (struct rt6_info *)inet->cork.base.dst;
1499 struct flowi6 *fl6 = &inet->cork.fl.u.ip6;
1500 unsigned char proto = fl6->flowi6_proto;
1501 int err = 0;
1502
1503 if ((skb = __skb_dequeue(&sk->sk_write_queue)) == NULL)
1504 goto out;
1505 tail_skb = &(skb_shinfo(skb)->frag_list);
1506
1507 /* move skb->data to ip header from ext header */
1508 if (skb->data < skb_network_header(skb))
1509 __skb_pull(skb, skb_network_offset(skb));
1510 while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) {
1511 __skb_pull(tmp_skb, skb_network_header_len(skb));
1512 *tail_skb = tmp_skb;
1513 tail_skb = &(tmp_skb->next);
1514 skb->len += tmp_skb->len;
1515 skb->data_len += tmp_skb->len;
1516 skb->truesize += tmp_skb->truesize;
1517 tmp_skb->destructor = NULL;
1518 tmp_skb->sk = NULL;
1519 }
1520
1521 /* Allow local fragmentation. */
1522 if (np->pmtudisc < IPV6_PMTUDISC_DO)
1523 skb->local_df = 1;
1524
1525 *final_dst = fl6->daddr;
1526 __skb_pull(skb, skb_network_header_len(skb));
1527 if (opt && opt->opt_flen)
1528 ipv6_push_frag_opts(skb, opt, &proto);
1529 if (opt && opt->opt_nflen)
1530 ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst);
1531
1532 skb_push(skb, sizeof(struct ipv6hdr));
1533 skb_reset_network_header(skb);
1534 hdr = ipv6_hdr(skb);
1535
1536 ip6_flow_hdr(hdr, np->cork.tclass, fl6->flowlabel);
1537 hdr->hop_limit = np->cork.hop_limit;
1538 hdr->nexthdr = proto;
1539 hdr->saddr = fl6->saddr;
1540 hdr->daddr = *final_dst;
1541
1542 skb->priority = sk->sk_priority;
1543 skb->mark = sk->sk_mark;
1544
1545 skb_dst_set(skb, dst_clone(&rt->dst));
1546 IP6_UPD_PO_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUT, skb->len);
1547 if (proto == IPPROTO_ICMPV6) {
1548 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
1549
1550 ICMP6MSGOUT_INC_STATS_BH(net, idev, icmp6_hdr(skb)->icmp6_type);
1551 ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTMSGS);
1552 }
1553
1554 err = ip6_local_out(skb);
1555 if (err) {
1556 if (err > 0)
1557 err = net_xmit_errno(err);
1558 if (err)
1559 goto error;
1560 }
1561
1562 out:
1563 ip6_cork_release(inet, np);
1564 return err;
1565 error:
1566 IP6_INC_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS);
1567 goto out;
1568 }
1569 EXPORT_SYMBOL_GPL(ip6_push_pending_frames);
1570
1571 void ip6_flush_pending_frames(struct sock *sk)
1572 {
1573 struct sk_buff *skb;
1574
1575 while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) {
1576 if (skb_dst(skb))
1577 IP6_INC_STATS(sock_net(sk), ip6_dst_idev(skb_dst(skb)),
1578 IPSTATS_MIB_OUTDISCARDS);
1579 kfree_skb(skb);
1580 }
1581
1582 ip6_cork_release(inet_sk(sk), inet6_sk(sk));
1583 }
1584 EXPORT_SYMBOL_GPL(ip6_flush_pending_frames);
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