]> git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blob - net/ipv6/ip6_output.c
projects / mirror_ubuntu-artful-kernel.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
quota: correct space limit check
[mirror_ubuntu-artful-kernel.git] / net / ipv6 / ip6_output.c
1 /*
2 * IPv6 output functions
3 * Linux INET6 implementation
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 *
8 * Based on linux/net/ipv4/ip_output.c
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * as published by the Free Software Foundation; either version
13 * 2 of the License, or (at your option) any later version.
14 *
15 * Changes:
16 * A.N.Kuznetsov : airthmetics in fragmentation.
17 * extension headers are implemented.
18 * route changes now work.
19 * ip6_forward does not confuse sniffers.
20 * etc.
21 *
22 * H. von Brand : Added missing #include <linux/string.h>
23 * Imran Patel : frag id should be in NBO
24 * Kazunori MIYAZAWA @USAGI
25 * : add ip6_append_data and related functions
26 * for datagram xmit
27 */
28
29 #include <linux/errno.h>
30 #include <linux/kernel.h>
31 #include <linux/string.h>
32 #include <linux/socket.h>
33 #include <linux/net.h>
34 #include <linux/netdevice.h>
35 #include <linux/if_arp.h>
36 #include <linux/in6.h>
37 #include <linux/tcp.h>
38 #include <linux/route.h>
39 #include <linux/module.h>
40 #include <linux/slab.h>
41
42 #include <linux/bpf-cgroup.h>
43 #include <linux/netfilter.h>
44 #include <linux/netfilter_ipv6.h>
45
46 #include <net/sock.h>
47 #include <net/snmp.h>
48
49 #include <net/ipv6.h>
50 #include <net/ndisc.h>
51 #include <net/protocol.h>
52 #include <net/ip6_route.h>
53 #include <net/addrconf.h>
54 #include <net/rawv6.h>
55 #include <net/icmp.h>
56 #include <net/xfrm.h>
57 #include <net/checksum.h>
58 #include <linux/mroute6.h>
59 #include <net/l3mdev.h>
60 #include <net/lwtunnel.h>
61
62 static int ip6_finish_output2(struct net *net, struct sock *sk, struct sk_buff *skb)
63 {
64 struct dst_entry *dst = skb_dst(skb);
65 struct net_device *dev = dst->dev;
66 struct neighbour *neigh;
67 struct in6_addr *nexthop;
68 int ret;
69
70 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) {
71 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
72
73 if (!(dev->flags & IFF_LOOPBACK) && sk_mc_loop(sk) &&
74 ((mroute6_socket(net, skb) &&
75 !(IP6CB(skb)->flags & IP6SKB_FORWARDED)) ||
76 ipv6_chk_mcast_addr(dev, &ipv6_hdr(skb)->daddr,
77 &ipv6_hdr(skb)->saddr))) {
78 struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC);
79
80 /* Do not check for IFF_ALLMULTI; multicast routing
81 is not supported in any case.
82 */
83 if (newskb)
84 NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING,
85 net, sk, newskb, NULL, newskb->dev,
86 dev_loopback_xmit);
87
88 if (ipv6_hdr(skb)->hop_limit == 0) {
89 IP6_INC_STATS(net, idev,
90 IPSTATS_MIB_OUTDISCARDS);
91 kfree_skb(skb);
92 return 0;
93 }
94 }
95
96 IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUTMCAST, skb->len);
97
98 if (IPV6_ADDR_MC_SCOPE(&ipv6_hdr(skb)->daddr) <=
99 IPV6_ADDR_SCOPE_NODELOCAL &&
100 !(dev->flags & IFF_LOOPBACK)) {
101 kfree_skb(skb);
102 return 0;
103 }
104 }
105
106 if (lwtunnel_xmit_redirect(dst->lwtstate)) {
107 int res = lwtunnel_xmit(skb);
108
109 if (res < 0 || res == LWTUNNEL_XMIT_DONE)
110 return res;
111 }
112
113 rcu_read_lock_bh();
114 nexthop = rt6_nexthop((struct rt6_info *)dst, &ipv6_hdr(skb)->daddr);
115 neigh = __ipv6_neigh_lookup_noref(dst->dev, nexthop);
116 if (unlikely(!neigh))
117 neigh = __neigh_create(&nd_tbl, nexthop, dst->dev, false);
118 if (!IS_ERR(neigh)) {
119 sock_confirm_neigh(skb, neigh);
120 ret = neigh_output(neigh, skb);
121 rcu_read_unlock_bh();
122 return ret;
123 }
124 rcu_read_unlock_bh();
125
126 IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
127 kfree_skb(skb);
128 return -EINVAL;
129 }
130
131 static int ip6_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb)
132 {
133 int ret;
134
135 ret = BPF_CGROUP_RUN_PROG_INET_EGRESS(sk, skb);
136 if (ret) {
137 kfree_skb(skb);
138 return ret;
139 }
140
141 if ((skb->len > ip6_skb_dst_mtu(skb) && !skb_is_gso(skb)) ||
142 dst_allfrag(skb_dst(skb)) ||
143 (IP6CB(skb)->frag_max_size && skb->len > IP6CB(skb)->frag_max_size))
144 return ip6_fragment(net, sk, skb, ip6_finish_output2);
145 else
146 return ip6_finish_output2(net, sk, skb);
147 }
148
149 int ip6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
150 {
151 struct net_device *dev = skb_dst(skb)->dev;
152 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
153
154 skb->protocol = htons(ETH_P_IPV6);
155 skb->dev = dev;
156
157 if (unlikely(idev->cnf.disable_ipv6)) {
158 IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTDISCARDS);
159 kfree_skb(skb);
160 return 0;
161 }
162
163 return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING,
164 net, sk, skb, NULL, dev,
165 ip6_finish_output,
166 !(IP6CB(skb)->flags & IP6SKB_REROUTED));
167 }
168
169 /*
170 * xmit an sk_buff (used by TCP, SCTP and DCCP)
171 * Note : socket lock is not held for SYNACK packets, but might be modified
172 * by calls to skb_set_owner_w() and ipv6_local_error(),
173 * which are using proper atomic operations or spinlocks.
174 */
175 int ip6_xmit(const struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
176 __u32 mark, struct ipv6_txoptions *opt, int tclass)
177 {
178 struct net *net = sock_net(sk);
179 const struct ipv6_pinfo *np = inet6_sk(sk);
180 struct in6_addr *first_hop = &fl6->daddr;
181 struct dst_entry *dst = skb_dst(skb);
182 struct ipv6hdr *hdr;
183 u8 proto = fl6->flowi6_proto;
184 int seg_len = skb->len;
185 int hlimit = -1;
186 u32 mtu;
187
188 if (opt) {
189 unsigned int head_room;
190
191 /* First: exthdrs may take lots of space (~8K for now)
192 MAX_HEADER is not enough.
193 */
194 head_room = opt->opt_nflen + opt->opt_flen;
195 seg_len += head_room;
196 head_room += sizeof(struct ipv6hdr) + LL_RESERVED_SPACE(dst->dev);
197
198 if (skb_headroom(skb) < head_room) {
199 struct sk_buff *skb2 = skb_realloc_headroom(skb, head_room);
200 if (!skb2) {
201 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
202 IPSTATS_MIB_OUTDISCARDS);
203 kfree_skb(skb);
204 return -ENOBUFS;
205 }
206 consume_skb(skb);
207 skb = skb2;
208 /* skb_set_owner_w() changes sk->sk_wmem_alloc atomically,
209 * it is safe to call in our context (socket lock not held)
210 */
211 skb_set_owner_w(skb, (struct sock *)sk);
212 }
213 if (opt->opt_flen)
214 ipv6_push_frag_opts(skb, opt, &proto);
215 if (opt->opt_nflen)
216 ipv6_push_nfrag_opts(skb, opt, &proto, &first_hop,
217 &fl6->saddr);
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, ip6_make_flowlabel(net, skb, fl6->flowlabel,
233 np->autoflowlabel, fl6));
234
235 hdr->payload_len = htons(seg_len);
236 hdr->nexthdr = proto;
237 hdr->hop_limit = hlimit;
238
239 hdr->saddr = fl6->saddr;
240 hdr->daddr = *first_hop;
241
242 skb->protocol = htons(ETH_P_IPV6);
243 skb->priority = sk->sk_priority;
244 skb->mark = mark;
245
246 mtu = dst_mtu(dst);
247 if ((skb->len <= mtu) || skb->ignore_df || skb_is_gso(skb)) {
248 IP6_UPD_PO_STATS(net, ip6_dst_idev(skb_dst(skb)),
249 IPSTATS_MIB_OUT, skb->len);
250
251 /* if egress device is enslaved to an L3 master device pass the
252 * skb to its handler for processing
253 */
254 skb = l3mdev_ip6_out((struct sock *)sk, skb);
255 if (unlikely(!skb))
256 return 0;
257
258 /* hooks should never assume socket lock is held.
259 * we promote our socket to non const
260 */
261 return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
262 net, (struct sock *)sk, skb, NULL, dst->dev,
263 dst_output);
264 }
265
266 skb->dev = dst->dev;
267 /* ipv6_local_error() does not require socket lock,
268 * we promote our socket to non const
269 */
270 ipv6_local_error((struct sock *)sk, EMSGSIZE, fl6, mtu);
271
272 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_FRAGFAILS);
273 kfree_skb(skb);
274 return -EMSGSIZE;
275 }
276 EXPORT_SYMBOL(ip6_xmit);
277
278 static int ip6_call_ra_chain(struct sk_buff *skb, int sel)
279 {
280 struct ip6_ra_chain *ra;
281 struct sock *last = NULL;
282
283 read_lock(&ip6_ra_lock);
284 for (ra = ip6_ra_chain; ra; ra = ra->next) {
285 struct sock *sk = ra->sk;
286 if (sk && ra->sel == sel &&
287 (!sk->sk_bound_dev_if ||
288 sk->sk_bound_dev_if == skb->dev->ifindex)) {
289 if (last) {
290 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
291 if (skb2)
292 rawv6_rcv(last, skb2);
293 }
294 last = sk;
295 }
296 }
297
298 if (last) {
299 rawv6_rcv(last, skb);
300 read_unlock(&ip6_ra_lock);
301 return 1;
302 }
303 read_unlock(&ip6_ra_lock);
304 return 0;
305 }
306
307 static int ip6_forward_proxy_check(struct sk_buff *skb)
308 {
309 struct ipv6hdr *hdr = ipv6_hdr(skb);
310 u8 nexthdr = hdr->nexthdr;
311 __be16 frag_off;
312 int offset;
313
314 if (ipv6_ext_hdr(nexthdr)) {
315 offset = ipv6_skip_exthdr(skb, sizeof(*hdr), &nexthdr, &frag_off);
316 if (offset < 0)
317 return 0;
318 } else
319 offset = sizeof(struct ipv6hdr);
320
321 if (nexthdr == IPPROTO_ICMPV6) {
322 struct icmp6hdr *icmp6;
323
324 if (!pskb_may_pull(skb, (skb_network_header(skb) +
325 offset + 1 - skb->data)))
326 return 0;
327
328 icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset);
329
330 switch (icmp6->icmp6_type) {
331 case NDISC_ROUTER_SOLICITATION:
332 case NDISC_ROUTER_ADVERTISEMENT:
333 case NDISC_NEIGHBOUR_SOLICITATION:
334 case NDISC_NEIGHBOUR_ADVERTISEMENT:
335 case NDISC_REDIRECT:
336 /* For reaction involving unicast neighbor discovery
337 * message destined to the proxied address, pass it to
338 * input function.
339 */
340 return 1;
341 default:
342 break;
343 }
344 }
345
346 /*
347 * The proxying router can't forward traffic sent to a link-local
348 * address, so signal the sender and discard the packet. This
349 * behavior is clarified by the MIPv6 specification.
350 */
351 if (ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) {
352 dst_link_failure(skb);
353 return -1;
354 }
355
356 return 0;
357 }
358
359 static inline int ip6_forward_finish(struct net *net, struct sock *sk,
360 struct sk_buff *skb)
361 {
362 return dst_output(net, sk, skb);
363 }
364
365 static unsigned int ip6_dst_mtu_forward(const struct dst_entry *dst)
366 {
367 unsigned int mtu;
368 struct inet6_dev *idev;
369
370 if (dst_metric_locked(dst, RTAX_MTU)) {
371 mtu = dst_metric_raw(dst, RTAX_MTU);
372 if (mtu)
373 return mtu;
374 }
375
376 mtu = IPV6_MIN_MTU;
377 rcu_read_lock();
378 idev = __in6_dev_get(dst->dev);
379 if (idev)
380 mtu = idev->cnf.mtu6;
381 rcu_read_unlock();
382
383 return mtu;
384 }
385
386 static bool ip6_pkt_too_big(const struct sk_buff *skb, unsigned int mtu)
387 {
388 if (skb->len <= mtu)
389 return false;
390
391 /* ipv6 conntrack defrag sets max_frag_size + ignore_df */
392 if (IP6CB(skb)->frag_max_size && IP6CB(skb)->frag_max_size > mtu)
393 return true;
394
395 if (skb->ignore_df)
396 return false;
397
398 if (skb_is_gso(skb) && skb_gso_validate_mtu(skb, mtu))
399 return false;
400
401 return true;
402 }
403
404 int ip6_forward(struct sk_buff *skb)
405 {
406 struct dst_entry *dst = skb_dst(skb);
407 struct ipv6hdr *hdr = ipv6_hdr(skb);
408 struct inet6_skb_parm *opt = IP6CB(skb);
409 struct net *net = dev_net(dst->dev);
410 u32 mtu;
411
412 if (net->ipv6.devconf_all->forwarding == 0)
413 goto error;
414
415 if (skb->pkt_type != PACKET_HOST)
416 goto drop;
417
418 if (unlikely(skb->sk))
419 goto drop;
420
421 if (skb_warn_if_lro(skb))
422 goto drop;
423
424 if (!xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) {
425 __IP6_INC_STATS(net, ip6_dst_idev(dst),
426 IPSTATS_MIB_INDISCARDS);
427 goto drop;
428 }
429
430 skb_forward_csum(skb);
431
432 /*
433 * We DO NOT make any processing on
434 * RA packets, pushing them to user level AS IS
435 * without ane WARRANTY that application will be able
436 * to interpret them. The reason is that we
437 * cannot make anything clever here.
438 *
439 * We are not end-node, so that if packet contains
440 * AH/ESP, we cannot make anything.
441 * Defragmentation also would be mistake, RA packets
442 * cannot be fragmented, because there is no warranty
443 * that different fragments will go along one path. --ANK
444 */
445 if (unlikely(opt->flags & IP6SKB_ROUTERALERT)) {
446 if (ip6_call_ra_chain(skb, ntohs(opt->ra)))
447 return 0;
448 }
449
450 /*
451 * check and decrement ttl
452 */
453 if (hdr->hop_limit <= 1) {
454 /* Force OUTPUT device used as source address */
455 skb->dev = dst->dev;
456 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 0);
457 __IP6_INC_STATS(net, ip6_dst_idev(dst),
458 IPSTATS_MIB_INHDRERRORS);
459
460 kfree_skb(skb);
461 return -ETIMEDOUT;
462 }
463
464 /* XXX: idev->cnf.proxy_ndp? */
465 if (net->ipv6.devconf_all->proxy_ndp &&
466 pneigh_lookup(&nd_tbl, net, &hdr->daddr, skb->dev, 0)) {
467 int proxied = ip6_forward_proxy_check(skb);
468 if (proxied > 0)
469 return ip6_input(skb);
470 else if (proxied < 0) {
471 __IP6_INC_STATS(net, ip6_dst_idev(dst),
472 IPSTATS_MIB_INDISCARDS);
473 goto drop;
474 }
475 }
476
477 if (!xfrm6_route_forward(skb)) {
478 __IP6_INC_STATS(net, ip6_dst_idev(dst),
479 IPSTATS_MIB_INDISCARDS);
480 goto drop;
481 }
482 dst = skb_dst(skb);
483
484 /* IPv6 specs say nothing about it, but it is clear that we cannot
485 send redirects to source routed frames.
486 We don't send redirects to frames decapsulated from IPsec.
487 */
488 if (skb->dev == dst->dev && opt->srcrt == 0 && !skb_sec_path(skb)) {
489 struct in6_addr *target = NULL;
490 struct inet_peer *peer;
491 struct rt6_info *rt;
492
493 /*
494 * incoming and outgoing devices are the same
495 * send a redirect.
496 */
497
498 rt = (struct rt6_info *) dst;
499 if (rt->rt6i_flags & RTF_GATEWAY)
500 target = &rt->rt6i_gateway;
501 else
502 target = &hdr->daddr;
503
504 peer = inet_getpeer_v6(net->ipv6.peers, &hdr->daddr, 1);
505
506 /* Limit redirects both by destination (here)
507 and by source (inside ndisc_send_redirect)
508 */
509 if (inet_peer_xrlim_allow(peer, 1*HZ))
510 ndisc_send_redirect(skb, target);
511 if (peer)
512 inet_putpeer(peer);
513 } else {
514 int addrtype = ipv6_addr_type(&hdr->saddr);
515
516 /* This check is security critical. */
517 if (addrtype == IPV6_ADDR_ANY ||
518 addrtype & (IPV6_ADDR_MULTICAST | IPV6_ADDR_LOOPBACK))
519 goto error;
520 if (addrtype & IPV6_ADDR_LINKLOCAL) {
521 icmpv6_send(skb, ICMPV6_DEST_UNREACH,
522 ICMPV6_NOT_NEIGHBOUR, 0);
523 goto error;
524 }
525 }
526
527 mtu = ip6_dst_mtu_forward(dst);
528 if (mtu < IPV6_MIN_MTU)
529 mtu = IPV6_MIN_MTU;
530
531 if (ip6_pkt_too_big(skb, mtu)) {
532 /* Again, force OUTPUT device used as source address */
533 skb->dev = dst->dev;
534 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
535 __IP6_INC_STATS(net, ip6_dst_idev(dst),
536 IPSTATS_MIB_INTOOBIGERRORS);
537 __IP6_INC_STATS(net, ip6_dst_idev(dst),
538 IPSTATS_MIB_FRAGFAILS);
539 kfree_skb(skb);
540 return -EMSGSIZE;
541 }
542
543 if (skb_cow(skb, dst->dev->hard_header_len)) {
544 __IP6_INC_STATS(net, ip6_dst_idev(dst),
545 IPSTATS_MIB_OUTDISCARDS);
546 goto drop;
547 }
548
549 hdr = ipv6_hdr(skb);
550
551 /* Mangling hops number delayed to point after skb COW */
552
553 hdr->hop_limit--;
554
555 __IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTFORWDATAGRAMS);
556 __IP6_ADD_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTOCTETS, skb->len);
557 return NF_HOOK(NFPROTO_IPV6, NF_INET_FORWARD,
558 net, NULL, skb, skb->dev, dst->dev,
559 ip6_forward_finish);
560
561 error:
562 __IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_INADDRERRORS);
563 drop:
564 kfree_skb(skb);
565 return -EINVAL;
566 }
567
568 static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from)
569 {
570 to->pkt_type = from->pkt_type;
571 to->priority = from->priority;
572 to->protocol = from->protocol;
573 skb_dst_drop(to);
574 skb_dst_set(to, dst_clone(skb_dst(from)));
575 to->dev = from->dev;
576 to->mark = from->mark;
577
578 #ifdef CONFIG_NET_SCHED
579 to->tc_index = from->tc_index;
580 #endif
581 nf_copy(to, from);
582 skb_copy_secmark(to, from);
583 }
584
585 int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
586 int (*output)(struct net *, struct sock *, struct sk_buff *))
587 {
588 struct sk_buff *frag;
589 struct rt6_info *rt = (struct rt6_info *)skb_dst(skb);
590 struct ipv6_pinfo *np = skb->sk && !dev_recursion_level() ?
591 inet6_sk(skb->sk) : NULL;
592 struct ipv6hdr *tmp_hdr;
593 struct frag_hdr *fh;
594 unsigned int mtu, hlen, left, len;
595 int hroom, troom;
596 __be32 frag_id;
597 int ptr, offset = 0, err = 0;
598 u8 *prevhdr, nexthdr = 0;
599
600 err = ip6_find_1stfragopt(skb, &prevhdr);
601 if (err < 0)
602 goto fail;
603 hlen = err;
604 nexthdr = *prevhdr;
605
606 mtu = ip6_skb_dst_mtu(skb);
607
608 /* We must not fragment if the socket is set to force MTU discovery
609 * or if the skb it not generated by a local socket.
610 */
611 if (unlikely(!skb->ignore_df && skb->len > mtu))
612 goto fail_toobig;
613
614 if (IP6CB(skb)->frag_max_size) {
615 if (IP6CB(skb)->frag_max_size > mtu)
616 goto fail_toobig;
617
618 /* don't send fragments larger than what we received */
619 mtu = IP6CB(skb)->frag_max_size;
620 if (mtu < IPV6_MIN_MTU)
621 mtu = IPV6_MIN_MTU;
622 }
623
624 if (np && np->frag_size < mtu) {
625 if (np->frag_size)
626 mtu = np->frag_size;
627 }
628 if (mtu < hlen + sizeof(struct frag_hdr) + 8)
629 goto fail_toobig;
630 mtu -= hlen + sizeof(struct frag_hdr);
631
632 frag_id = ipv6_select_ident(net, &ipv6_hdr(skb)->daddr,
633 &ipv6_hdr(skb)->saddr);
634
635 if (skb->ip_summed == CHECKSUM_PARTIAL &&
636 (err = skb_checksum_help(skb)))
637 goto fail;
638
639 hroom = LL_RESERVED_SPACE(rt->dst.dev);
640 if (skb_has_frag_list(skb)) {
641 unsigned int first_len = skb_pagelen(skb);
642 struct sk_buff *frag2;
643
644 if (first_len - hlen > mtu ||
645 ((first_len - hlen) & 7) ||
646 skb_cloned(skb) ||
647 skb_headroom(skb) < (hroom + sizeof(struct frag_hdr)))
648 goto slow_path;
649
650 skb_walk_frags(skb, frag) {
651 /* Correct geometry. */
652 if (frag->len > mtu ||
653 ((frag->len & 7) && frag->next) ||
654 skb_headroom(frag) < (hlen + hroom + sizeof(struct frag_hdr)))
655 goto slow_path_clean;
656
657 /* Partially cloned skb? */
658 if (skb_shared(frag))
659 goto slow_path_clean;
660
661 BUG_ON(frag->sk);
662 if (skb->sk) {
663 frag->sk = skb->sk;
664 frag->destructor = sock_wfree;
665 }
666 skb->truesize -= frag->truesize;
667 }
668
669 err = 0;
670 offset = 0;
671 /* BUILD HEADER */
672
673 *prevhdr = NEXTHDR_FRAGMENT;
674 tmp_hdr = kmemdup(skb_network_header(skb), hlen, GFP_ATOMIC);
675 if (!tmp_hdr) {
676 err = -ENOMEM;
677 goto fail;
678 }
679 frag = skb_shinfo(skb)->frag_list;
680 skb_frag_list_init(skb);
681
682 __skb_pull(skb, hlen);
683 fh = __skb_push(skb, sizeof(struct frag_hdr));
684 __skb_push(skb, hlen);
685 skb_reset_network_header(skb);
686 memcpy(skb_network_header(skb), tmp_hdr, hlen);
687
688 fh->nexthdr = nexthdr;
689 fh->reserved = 0;
690 fh->frag_off = htons(IP6_MF);
691 fh->identification = frag_id;
692
693 first_len = skb_pagelen(skb);
694 skb->data_len = first_len - skb_headlen(skb);
695 skb->len = first_len;
696 ipv6_hdr(skb)->payload_len = htons(first_len -
697 sizeof(struct ipv6hdr));
698
699 for (;;) {
700 /* Prepare header of the next frame,
701 * before previous one went down. */
702 if (frag) {
703 frag->ip_summed = CHECKSUM_NONE;
704 skb_reset_transport_header(frag);
705 fh = __skb_push(frag, sizeof(struct frag_hdr));
706 __skb_push(frag, hlen);
707 skb_reset_network_header(frag);
708 memcpy(skb_network_header(frag), tmp_hdr,
709 hlen);
710 offset += skb->len - hlen - sizeof(struct frag_hdr);
711 fh->nexthdr = nexthdr;
712 fh->reserved = 0;
713 fh->frag_off = htons(offset);
714 if (frag->next)
715 fh->frag_off |= htons(IP6_MF);
716 fh->identification = frag_id;
717 ipv6_hdr(frag)->payload_len =
718 htons(frag->len -
719 sizeof(struct ipv6hdr));
720 ip6_copy_metadata(frag, skb);
721 }
722
723 err = output(net, sk, skb);
724 if (!err)
725 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
726 IPSTATS_MIB_FRAGCREATES);
727
728 if (err || !frag)
729 break;
730
731 skb = frag;
732 frag = skb->next;
733 skb->next = NULL;
734 }
735
736 kfree(tmp_hdr);
737
738 if (err == 0) {
739 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
740 IPSTATS_MIB_FRAGOKS);
741 return 0;
742 }
743
744 kfree_skb_list(frag);
745
746 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
747 IPSTATS_MIB_FRAGFAILS);
748 return err;
749
750 slow_path_clean:
751 skb_walk_frags(skb, frag2) {
752 if (frag2 == frag)
753 break;
754 frag2->sk = NULL;
755 frag2->destructor = NULL;
756 skb->truesize += frag2->truesize;
757 }
758 }
759
760 slow_path:
761 left = skb->len - hlen; /* Space per frame */
762 ptr = hlen; /* Where to start from */
763
764 /*
765 * Fragment the datagram.
766 */
767
768 troom = rt->dst.dev->needed_tailroom;
769
770 /*
771 * Keep copying data until we run out.
772 */
773 while (left > 0) {
774 u8 *fragnexthdr_offset;
775
776 len = left;
777 /* IF: it doesn't fit, use 'mtu' - the data space left */
778 if (len > mtu)
779 len = mtu;
780 /* IF: we are not sending up to and including the packet end
781 then align the next start on an eight byte boundary */
782 if (len < left) {
783 len &= ~7;
784 }
785
786 /* Allocate buffer */
787 frag = alloc_skb(len + hlen + sizeof(struct frag_hdr) +
788 hroom + troom, GFP_ATOMIC);
789 if (!frag) {
790 err = -ENOMEM;
791 goto fail;
792 }
793
794 /*
795 * Set up data on packet
796 */
797
798 ip6_copy_metadata(frag, skb);
799 skb_reserve(frag, hroom);
800 skb_put(frag, len + hlen + sizeof(struct frag_hdr));
801 skb_reset_network_header(frag);
802 fh = (struct frag_hdr *)(skb_network_header(frag) + hlen);
803 frag->transport_header = (frag->network_header + hlen +
804 sizeof(struct frag_hdr));
805
806 /*
807 * Charge the memory for the fragment to any owner
808 * it might possess
809 */
810 if (skb->sk)
811 skb_set_owner_w(frag, skb->sk);
812
813 /*
814 * Copy the packet header into the new buffer.
815 */
816 skb_copy_from_linear_data(skb, skb_network_header(frag), hlen);
817
818 fragnexthdr_offset = skb_network_header(frag);
819 fragnexthdr_offset += prevhdr - skb_network_header(skb);
820 *fragnexthdr_offset = NEXTHDR_FRAGMENT;
821
822 /*
823 * Build fragment header.
824 */
825 fh->nexthdr = nexthdr;
826 fh->reserved = 0;
827 fh->identification = frag_id;
828
829 /*
830 * Copy a block of the IP datagram.
831 */
832 BUG_ON(skb_copy_bits(skb, ptr, skb_transport_header(frag),
833 len));
834 left -= len;
835
836 fh->frag_off = htons(offset);
837 if (left > 0)
838 fh->frag_off |= htons(IP6_MF);
839 ipv6_hdr(frag)->payload_len = htons(frag->len -
840 sizeof(struct ipv6hdr));
841
842 ptr += len;
843 offset += len;
844
845 /*
846 * Put this fragment into the sending queue.
847 */
848 err = output(net, sk, frag);
849 if (err)
850 goto fail;
851
852 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
853 IPSTATS_MIB_FRAGCREATES);
854 }
855 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
856 IPSTATS_MIB_FRAGOKS);
857 consume_skb(skb);
858 return err;
859
860 fail_toobig:
861 if (skb->sk && dst_allfrag(skb_dst(skb)))
862 sk_nocaps_add(skb->sk, NETIF_F_GSO_MASK);
863
864 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
865 err = -EMSGSIZE;
866
867 fail:
868 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
869 IPSTATS_MIB_FRAGFAILS);
870 kfree_skb(skb);
871 return err;
872 }
873
874 static inline int ip6_rt_check(const struct rt6key *rt_key,
875 const struct in6_addr *fl_addr,
876 const struct in6_addr *addr_cache)
877 {
878 return (rt_key->plen != 128 || !ipv6_addr_equal(fl_addr, &rt_key->addr)) &&
879 (!addr_cache || !ipv6_addr_equal(fl_addr, addr_cache));
880 }
881
882 static struct dst_entry *ip6_sk_dst_check(struct sock *sk,
883 struct dst_entry *dst,
884 const struct flowi6 *fl6)
885 {
886 struct ipv6_pinfo *np = inet6_sk(sk);
887 struct rt6_info *rt;
888
889 if (!dst)
890 goto out;
891
892 if (dst->ops->family != AF_INET6) {
893 dst_release(dst);
894 return NULL;
895 }
896
897 rt = (struct rt6_info *)dst;
898 /* Yes, checking route validity in not connected
899 * case is not very simple. Take into account,
900 * that we do not support routing by source, TOS,
901 * and MSG_DONTROUTE --ANK (980726)
902 *
903 * 1. ip6_rt_check(): If route was host route,
904 * check that cached destination is current.
905 * If it is network route, we still may
906 * check its validity using saved pointer
907 * to the last used address: daddr_cache.
908 * We do not want to save whole address now,
909 * (because main consumer of this service
910 * is tcp, which has not this problem),
911 * so that the last trick works only on connected
912 * sockets.
913 * 2. oif also should be the same.
914 */
915 if (ip6_rt_check(&rt->rt6i_dst, &fl6->daddr, np->daddr_cache) ||
916 #ifdef CONFIG_IPV6_SUBTREES
917 ip6_rt_check(&rt->rt6i_src, &fl6->saddr, np->saddr_cache) ||
918 #endif
919 (!(fl6->flowi6_flags & FLOWI_FLAG_SKIP_NH_OIF) &&
920 (fl6->flowi6_oif && fl6->flowi6_oif != dst->dev->ifindex))) {
921 dst_release(dst);
922 dst = NULL;
923 }
924
925 out:
926 return dst;
927 }
928
929 static int ip6_dst_lookup_tail(struct net *net, const struct sock *sk,
930 struct dst_entry **dst, struct flowi6 *fl6)
931 {
932 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
933 struct neighbour *n;
934 struct rt6_info *rt;
935 #endif
936 int err;
937 int flags = 0;
938
939 /* The correct way to handle this would be to do
940 * ip6_route_get_saddr, and then ip6_route_output; however,
941 * the route-specific preferred source forces the
942 * ip6_route_output call _before_ ip6_route_get_saddr.
943 *
944 * In source specific routing (no src=any default route),
945 * ip6_route_output will fail given src=any saddr, though, so
946 * that's why we try it again later.
947 */
948 if (ipv6_addr_any(&fl6->saddr) && (!*dst || !(*dst)->error)) {
949 struct rt6_info *rt;
950 bool had_dst = *dst != NULL;
951
952 if (!had_dst)
953 *dst = ip6_route_output(net, sk, fl6);
954 rt = (*dst)->error ? NULL : (struct rt6_info *)*dst;
955 err = ip6_route_get_saddr(net, rt, &fl6->daddr,
956 sk ? inet6_sk(sk)->srcprefs : 0,
957 &fl6->saddr);
958 if (err)
959 goto out_err_release;
960
961 /* If we had an erroneous initial result, pretend it
962 * never existed and let the SA-enabled version take
963 * over.
964 */
965 if (!had_dst && (*dst)->error) {
966 dst_release(*dst);
967 *dst = NULL;
968 }
969
970 if (fl6->flowi6_oif)
971 flags |= RT6_LOOKUP_F_IFACE;
972 }
973
974 if (!*dst)
975 *dst = ip6_route_output_flags(net, sk, fl6, flags);
976
977 err = (*dst)->error;
978 if (err)
979 goto out_err_release;
980
981 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
982 /*
983 * Here if the dst entry we've looked up
984 * has a neighbour entry that is in the INCOMPLETE
985 * state and the src address from the flow is
986 * marked as OPTIMISTIC, we release the found
987 * dst entry and replace it instead with the
988 * dst entry of the nexthop router
989 */
990 rt = (struct rt6_info *) *dst;
991 rcu_read_lock_bh();
992 n = __ipv6_neigh_lookup_noref(rt->dst.dev,
993 rt6_nexthop(rt, &fl6->daddr));
994 err = n && !(n->nud_state & NUD_VALID) ? -EINVAL : 0;
995 rcu_read_unlock_bh();
996
997 if (err) {
998 struct inet6_ifaddr *ifp;
999 struct flowi6 fl_gw6;
1000 int redirect;
1001
1002 ifp = ipv6_get_ifaddr(net, &fl6->saddr,
1003 (*dst)->dev, 1);
1004
1005 redirect = (ifp && ifp->flags & IFA_F_OPTIMISTIC);
1006 if (ifp)
1007 in6_ifa_put(ifp);
1008
1009 if (redirect) {
1010 /*
1011 * We need to get the dst entry for the
1012 * default router instead
1013 */
1014 dst_release(*dst);
1015 memcpy(&fl_gw6, fl6, sizeof(struct flowi6));
1016 memset(&fl_gw6.daddr, 0, sizeof(struct in6_addr));
1017 *dst = ip6_route_output(net, sk, &fl_gw6);
1018 err = (*dst)->error;
1019 if (err)
1020 goto out_err_release;
1021 }
1022 }
1023 #endif
1024 if (ipv6_addr_v4mapped(&fl6->saddr) &&
1025 !(ipv6_addr_v4mapped(&fl6->daddr) || ipv6_addr_any(&fl6->daddr))) {
1026 err = -EAFNOSUPPORT;
1027 goto out_err_release;
1028 }
1029
1030 return 0;
1031
1032 out_err_release:
1033 dst_release(*dst);
1034 *dst = NULL;
1035
1036 if (err == -ENETUNREACH)
1037 IP6_INC_STATS(net, NULL, IPSTATS_MIB_OUTNOROUTES);
1038 return err;
1039 }
1040
1041 /**
1042 * ip6_dst_lookup - perform route lookup on flow
1043 * @sk: socket which provides route info
1044 * @dst: pointer to dst_entry * for result
1045 * @fl6: flow to lookup
1046 *
1047 * This function performs a route lookup on the given flow.
1048 *
1049 * It returns zero on success, or a standard errno code on error.
1050 */
1051 int ip6_dst_lookup(struct net *net, struct sock *sk, struct dst_entry **dst,
1052 struct flowi6 *fl6)
1053 {
1054 *dst = NULL;
1055 return ip6_dst_lookup_tail(net, sk, dst, fl6);
1056 }
1057 EXPORT_SYMBOL_GPL(ip6_dst_lookup);
1058
1059 /**
1060 * ip6_dst_lookup_flow - perform route lookup on flow with ipsec
1061 * @sk: socket which provides route info
1062 * @fl6: flow to lookup
1063 * @final_dst: final destination address for ipsec lookup
1064 *
1065 * This function performs a route lookup on the given flow.
1066 *
1067 * It returns a valid dst pointer on success, or a pointer encoded
1068 * error code.
1069 */
1070 struct dst_entry *ip6_dst_lookup_flow(const struct sock *sk, struct flowi6 *fl6,
1071 const struct in6_addr *final_dst)
1072 {
1073 struct dst_entry *dst = NULL;
1074 int err;
1075
1076 err = ip6_dst_lookup_tail(sock_net(sk), sk, &dst, fl6);
1077 if (err)
1078 return ERR_PTR(err);
1079 if (final_dst)
1080 fl6->daddr = *final_dst;
1081
1082 return xfrm_lookup_route(sock_net(sk), dst, flowi6_to_flowi(fl6), sk, 0);
1083 }
1084 EXPORT_SYMBOL_GPL(ip6_dst_lookup_flow);
1085
1086 /**
1087 * ip6_sk_dst_lookup_flow - perform socket cached route lookup on flow
1088 * @sk: socket which provides the dst cache and route info
1089 * @fl6: flow to lookup
1090 * @final_dst: final destination address for ipsec lookup
1091 *
1092 * This function performs a route lookup on the given flow with the
1093 * possibility of using the cached route in the socket if it is valid.
1094 * It will take the socket dst lock when operating on the dst cache.
1095 * As a result, this function can only be used in process context.
1096 *
1097 * It returns a valid dst pointer on success, or a pointer encoded
1098 * error code.
1099 */
1100 struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
1101 const struct in6_addr *final_dst)
1102 {
1103 struct dst_entry *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie);
1104
1105 dst = ip6_sk_dst_check(sk, dst, fl6);
1106 if (!dst)
1107 dst = ip6_dst_lookup_flow(sk, fl6, final_dst);
1108
1109 return dst;
1110 }
1111 EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup_flow);
1112
1113 static inline int ip6_ufo_append_data(struct sock *sk,
1114 struct sk_buff_head *queue,
1115 int getfrag(void *from, char *to, int offset, int len,
1116 int odd, struct sk_buff *skb),
1117 void *from, int length, int hh_len, int fragheaderlen,
1118 int exthdrlen, int transhdrlen, int mtu,
1119 unsigned int flags, const struct flowi6 *fl6)
1120
1121 {
1122 struct sk_buff *skb;
1123 int err;
1124
1125 /* There is support for UDP large send offload by network
1126 * device, so create one single skb packet containing complete
1127 * udp datagram
1128 */
1129 skb = skb_peek_tail(queue);
1130 if (!skb) {
1131 skb = sock_alloc_send_skb(sk,
1132 hh_len + fragheaderlen + transhdrlen + 20,
1133 (flags & MSG_DONTWAIT), &err);
1134 if (!skb)
1135 return err;
1136
1137 /* reserve space for Hardware header */
1138 skb_reserve(skb, hh_len);
1139
1140 /* create space for UDP/IP header */
1141 skb_put(skb, fragheaderlen + transhdrlen);
1142
1143 /* initialize network header pointer */
1144 skb_set_network_header(skb, exthdrlen);
1145
1146 /* initialize protocol header pointer */
1147 skb->transport_header = skb->network_header + fragheaderlen;
1148
1149 skb->protocol = htons(ETH_P_IPV6);
1150 skb->csum = 0;
1151
1152 if (flags & MSG_CONFIRM)
1153 skb_set_dst_pending_confirm(skb, 1);
1154
1155 __skb_queue_tail(queue, skb);
1156 } else if (skb_is_gso(skb)) {
1157 goto append;
1158 }
1159
1160 skb->ip_summed = CHECKSUM_PARTIAL;
1161 /* Specify the length of each IPv6 datagram fragment.
1162 * It has to be a multiple of 8.
1163 */
1164 skb_shinfo(skb)->gso_size = (mtu - fragheaderlen -
1165 sizeof(struct frag_hdr)) & ~7;
1166 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
1167 skb_shinfo(skb)->ip6_frag_id = ipv6_select_ident(sock_net(sk),
1168 &fl6->daddr,
1169 &fl6->saddr);
1170
1171 append:
1172 return skb_append_datato_frags(sk, skb, getfrag, from,
1173 (length - transhdrlen));
1174 }
1175
1176 static inline struct ipv6_opt_hdr *ip6_opt_dup(struct ipv6_opt_hdr *src,
1177 gfp_t gfp)
1178 {
1179 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL;
1180 }
1181
1182 static inline struct ipv6_rt_hdr *ip6_rthdr_dup(struct ipv6_rt_hdr *src,
1183 gfp_t gfp)
1184 {
1185 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL;
1186 }
1187
1188 static void ip6_append_data_mtu(unsigned int *mtu,
1189 int *maxfraglen,
1190 unsigned int fragheaderlen,
1191 struct sk_buff *skb,
1192 struct rt6_info *rt,
1193 unsigned int orig_mtu)
1194 {
1195 if (!(rt->dst.flags & DST_XFRM_TUNNEL)) {
1196 if (!skb) {
1197 /* first fragment, reserve header_len */
1198 *mtu = orig_mtu - rt->dst.header_len;
1199
1200 } else {
1201 /*
1202 * this fragment is not first, the headers
1203 * space is regarded as data space.
1204 */
1205 *mtu = orig_mtu;
1206 }
1207 *maxfraglen = ((*mtu - fragheaderlen) & ~7)
1208 + fragheaderlen - sizeof(struct frag_hdr);
1209 }
1210 }
1211
1212 static int ip6_setup_cork(struct sock *sk, struct inet_cork_full *cork,
1213 struct inet6_cork *v6_cork, struct ipcm6_cookie *ipc6,
1214 struct rt6_info *rt, struct flowi6 *fl6)
1215 {
1216 struct ipv6_pinfo *np = inet6_sk(sk);
1217 unsigned int mtu;
1218 struct ipv6_txoptions *opt = ipc6->opt;
1219
1220 /*
1221 * setup for corking
1222 */
1223 if (opt) {
1224 if (WARN_ON(v6_cork->opt))
1225 return -EINVAL;
1226
1227 v6_cork->opt = kzalloc(opt->tot_len, sk->sk_allocation);
1228 if (unlikely(!v6_cork->opt))
1229 return -ENOBUFS;
1230
1231 v6_cork->opt->tot_len = opt->tot_len;
1232 v6_cork->opt->opt_flen = opt->opt_flen;
1233 v6_cork->opt->opt_nflen = opt->opt_nflen;
1234
1235 v6_cork->opt->dst0opt = ip6_opt_dup(opt->dst0opt,
1236 sk->sk_allocation);
1237 if (opt->dst0opt && !v6_cork->opt->dst0opt)
1238 return -ENOBUFS;
1239
1240 v6_cork->opt->dst1opt = ip6_opt_dup(opt->dst1opt,
1241 sk->sk_allocation);
1242 if (opt->dst1opt && !v6_cork->opt->dst1opt)
1243 return -ENOBUFS;
1244
1245 v6_cork->opt->hopopt = ip6_opt_dup(opt->hopopt,
1246 sk->sk_allocation);
1247 if (opt->hopopt && !v6_cork->opt->hopopt)
1248 return -ENOBUFS;
1249
1250 v6_cork->opt->srcrt = ip6_rthdr_dup(opt->srcrt,
1251 sk->sk_allocation);
1252 if (opt->srcrt && !v6_cork->opt->srcrt)
1253 return -ENOBUFS;
1254
1255 /* need source address above miyazawa*/
1256 }
1257 dst_hold(&rt->dst);
1258 cork->base.dst = &rt->dst;
1259 cork->fl.u.ip6 = *fl6;
1260 v6_cork->hop_limit = ipc6->hlimit;
1261 v6_cork->tclass = ipc6->tclass;
1262 if (rt->dst.flags & DST_XFRM_TUNNEL)
1263 mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ?
1264 rt->dst.dev->mtu : dst_mtu(&rt->dst);
1265 else
1266 mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ?
1267 rt->dst.dev->mtu : dst_mtu(rt->dst.path);
1268 if (np->frag_size < mtu) {
1269 if (np->frag_size)
1270 mtu = np->frag_size;
1271 }
1272 cork->base.fragsize = mtu;
1273 if (dst_allfrag(rt->dst.path))
1274 cork->base.flags |= IPCORK_ALLFRAG;
1275 cork->base.length = 0;
1276
1277 return 0;
1278 }
1279
1280 static int __ip6_append_data(struct sock *sk,
1281 struct flowi6 *fl6,
1282 struct sk_buff_head *queue,
1283 struct inet_cork *cork,
1284 struct inet6_cork *v6_cork,
1285 struct page_frag *pfrag,
1286 int getfrag(void *from, char *to, int offset,
1287 int len, int odd, struct sk_buff *skb),
1288 void *from, int length, int transhdrlen,
1289 unsigned int flags, struct ipcm6_cookie *ipc6,
1290 const struct sockcm_cookie *sockc)
1291 {
1292 struct sk_buff *skb, *skb_prev = NULL;
1293 unsigned int maxfraglen, fragheaderlen, mtu, orig_mtu;
1294 int exthdrlen = 0;
1295 int dst_exthdrlen = 0;
1296 int hh_len;
1297 int copy;
1298 int err;
1299 int offset = 0;
1300 __u8 tx_flags = 0;
1301 u32 tskey = 0;
1302 struct rt6_info *rt = (struct rt6_info *)cork->dst;
1303 struct ipv6_txoptions *opt = v6_cork->opt;
1304 int csummode = CHECKSUM_NONE;
1305 unsigned int maxnonfragsize, headersize;
1306
1307 skb = skb_peek_tail(queue);
1308 if (!skb) {
1309 exthdrlen = opt ? opt->opt_flen : 0;
1310 dst_exthdrlen = rt->dst.header_len - rt->rt6i_nfheader_len;
1311 }
1312
1313 mtu = cork->fragsize;
1314 orig_mtu = mtu;
1315
1316 hh_len = LL_RESERVED_SPACE(rt->dst.dev);
1317
1318 fragheaderlen = sizeof(struct ipv6hdr) + rt->rt6i_nfheader_len +
1319 (opt ? opt->opt_nflen : 0);
1320 maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen -
1321 sizeof(struct frag_hdr);
1322
1323 headersize = sizeof(struct ipv6hdr) +
1324 (opt ? opt->opt_flen + opt->opt_nflen : 0) +
1325 (dst_allfrag(&rt->dst) ?
1326 sizeof(struct frag_hdr) : 0) +
1327 rt->rt6i_nfheader_len;
1328
1329 if (cork->length + length > mtu - headersize && ipc6->dontfrag &&
1330 (sk->sk_protocol == IPPROTO_UDP ||
1331 sk->sk_protocol == IPPROTO_RAW)) {
1332 ipv6_local_rxpmtu(sk, fl6, mtu - headersize +
1333 sizeof(struct ipv6hdr));
1334 goto emsgsize;
1335 }
1336
1337 if (ip6_sk_ignore_df(sk))
1338 maxnonfragsize = sizeof(struct ipv6hdr) + IPV6_MAXPLEN;
1339 else
1340 maxnonfragsize = mtu;
1341
1342 if (cork->length + length > maxnonfragsize - headersize) {
1343 emsgsize:
1344 ipv6_local_error(sk, EMSGSIZE, fl6,
1345 mtu - headersize +
1346 sizeof(struct ipv6hdr));
1347 return -EMSGSIZE;
1348 }
1349
1350 /* CHECKSUM_PARTIAL only with no extension headers and when
1351 * we are not going to fragment
1352 */
1353 if (transhdrlen && sk->sk_protocol == IPPROTO_UDP &&
1354 headersize == sizeof(struct ipv6hdr) &&
1355 length <= mtu - headersize &&
1356 !(flags & MSG_MORE) &&
1357 rt->dst.dev->features & (NETIF_F_IPV6_CSUM | NETIF_F_HW_CSUM))
1358 csummode = CHECKSUM_PARTIAL;
1359
1360 if (sk->sk_type == SOCK_DGRAM || sk->sk_type == SOCK_RAW) {
1361 sock_tx_timestamp(sk, sockc->tsflags, &tx_flags);
1362 if (tx_flags & SKBTX_ANY_SW_TSTAMP &&
1363 sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)
1364 tskey = sk->sk_tskey++;
1365 }
1366
1367 /*
1368 * Let's try using as much space as possible.
1369 * Use MTU if total length of the message fits into the MTU.
1370 * Otherwise, we need to reserve fragment header and
1371 * fragment alignment (= 8-15 octects, in total).
1372 *
1373 * Note that we may need to "move" the data from the tail of
1374 * of the buffer to the new fragment when we split
1375 * the message.
1376 *
1377 * FIXME: It may be fragmented into multiple chunks
1378 * at once if non-fragmentable extension headers
1379 * are too large.
1380 * --yoshfuji
1381 */
1382
1383 cork->length += length;
1384 if ((((length + (skb ? skb->len : headersize)) > mtu) ||
1385 (skb && skb_is_gso(skb))) &&
1386 (sk->sk_protocol == IPPROTO_UDP) &&
1387 (rt->dst.dev->features & NETIF_F_UFO) && !dst_xfrm(&rt->dst) &&
1388 (sk->sk_type == SOCK_DGRAM) && !udp_get_no_check6_tx(sk)) {
1389 err = ip6_ufo_append_data(sk, queue, getfrag, from, length,
1390 hh_len, fragheaderlen, exthdrlen,
1391 transhdrlen, mtu, flags, fl6);
1392 if (err)
1393 goto error;
1394 return 0;
1395 }
1396
1397 if (!skb)
1398 goto alloc_new_skb;
1399
1400 while (length > 0) {
1401 /* Check if the remaining data fits into current packet. */
1402 copy = (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len;
1403 if (copy < length)
1404 copy = maxfraglen - skb->len;
1405
1406 if (copy <= 0) {
1407 char *data;
1408 unsigned int datalen;
1409 unsigned int fraglen;
1410 unsigned int fraggap;
1411 unsigned int alloclen;
1412 alloc_new_skb:
1413 /* There's no room in the current skb */
1414 if (skb)
1415 fraggap = skb->len - maxfraglen;
1416 else
1417 fraggap = 0;
1418 /* update mtu and maxfraglen if necessary */
1419 if (!skb || !skb_prev)
1420 ip6_append_data_mtu(&mtu, &maxfraglen,
1421 fragheaderlen, skb, rt,
1422 orig_mtu);
1423
1424 skb_prev = skb;
1425
1426 /*
1427 * If remaining data exceeds the mtu,
1428 * we know we need more fragment(s).
1429 */
1430 datalen = length + fraggap;
1431
1432 if (datalen > (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen)
1433 datalen = maxfraglen - fragheaderlen - rt->dst.trailer_len;
1434 if ((flags & MSG_MORE) &&
1435 !(rt->dst.dev->features&NETIF_F_SG))
1436 alloclen = mtu;
1437 else
1438 alloclen = datalen + fragheaderlen;
1439
1440 alloclen += dst_exthdrlen;
1441
1442 if (datalen != length + fraggap) {
1443 /*
1444 * this is not the last fragment, the trailer
1445 * space is regarded as data space.
1446 */
1447 datalen += rt->dst.trailer_len;
1448 }
1449
1450 alloclen += rt->dst.trailer_len;
1451 fraglen = datalen + fragheaderlen;
1452
1453 /*
1454 * We just reserve space for fragment header.
1455 * Note: this may be overallocation if the message
1456 * (without MSG_MORE) fits into the MTU.
1457 */
1458 alloclen += sizeof(struct frag_hdr);
1459
1460 copy = datalen - transhdrlen - fraggap;
1461 if (copy < 0) {
1462 err = -EINVAL;
1463 goto error;
1464 }
1465 if (transhdrlen) {
1466 skb = sock_alloc_send_skb(sk,
1467 alloclen + hh_len,
1468 (flags & MSG_DONTWAIT), &err);
1469 } else {
1470 skb = NULL;
1471 if (refcount_read(&sk->sk_wmem_alloc) <=
1472 2 * sk->sk_sndbuf)
1473 skb = sock_wmalloc(sk,
1474 alloclen + hh_len, 1,
1475 sk->sk_allocation);
1476 if (unlikely(!skb))
1477 err = -ENOBUFS;
1478 }
1479 if (!skb)
1480 goto error;
1481 /*
1482 * Fill in the control structures
1483 */
1484 skb->protocol = htons(ETH_P_IPV6);
1485 skb->ip_summed = csummode;
1486 skb->csum = 0;
1487 /* reserve for fragmentation and ipsec header */
1488 skb_reserve(skb, hh_len + sizeof(struct frag_hdr) +
1489 dst_exthdrlen);
1490
1491 /* Only the initial fragment is time stamped */
1492 skb_shinfo(skb)->tx_flags = tx_flags;
1493 tx_flags = 0;
1494 skb_shinfo(skb)->tskey = tskey;
1495 tskey = 0;
1496
1497 /*
1498 * Find where to start putting bytes
1499 */
1500 data = skb_put(skb, fraglen);
1501 skb_set_network_header(skb, exthdrlen);
1502 data += fragheaderlen;
1503 skb->transport_header = (skb->network_header +
1504 fragheaderlen);
1505 if (fraggap) {
1506 skb->csum = skb_copy_and_csum_bits(
1507 skb_prev, maxfraglen,
1508 data + transhdrlen, fraggap, 0);
1509 skb_prev->csum = csum_sub(skb_prev->csum,
1510 skb->csum);
1511 data += fraggap;
1512 pskb_trim_unique(skb_prev, maxfraglen);
1513 }
1514 if (copy > 0 &&
1515 getfrag(from, data + transhdrlen, offset,
1516 copy, fraggap, skb) < 0) {
1517 err = -EFAULT;
1518 kfree_skb(skb);
1519 goto error;
1520 }
1521
1522 offset += copy;
1523 length -= datalen - fraggap;
1524 transhdrlen = 0;
1525 exthdrlen = 0;
1526 dst_exthdrlen = 0;
1527
1528 if ((flags & MSG_CONFIRM) && !skb_prev)
1529 skb_set_dst_pending_confirm(skb, 1);
1530
1531 /*
1532 * Put the packet on the pending queue
1533 */
1534 __skb_queue_tail(queue, skb);
1535 continue;
1536 }
1537
1538 if (copy > length)
1539 copy = length;
1540
1541 if (!(rt->dst.dev->features&NETIF_F_SG)) {
1542 unsigned int off;
1543
1544 off = skb->len;
1545 if (getfrag(from, skb_put(skb, copy),
1546 offset, copy, off, skb) < 0) {
1547 __skb_trim(skb, off);
1548 err = -EFAULT;
1549 goto error;
1550 }
1551 } else {
1552 int i = skb_shinfo(skb)->nr_frags;
1553
1554 err = -ENOMEM;
1555 if (!sk_page_frag_refill(sk, pfrag))
1556 goto error;
1557
1558 if (!skb_can_coalesce(skb, i, pfrag->page,
1559 pfrag->offset)) {
1560 err = -EMSGSIZE;
1561 if (i == MAX_SKB_FRAGS)
1562 goto error;
1563
1564 __skb_fill_page_desc(skb, i, pfrag->page,
1565 pfrag->offset, 0);
1566 skb_shinfo(skb)->nr_frags = ++i;
1567 get_page(pfrag->page);
1568 }
1569 copy = min_t(int, copy, pfrag->size - pfrag->offset);
1570 if (getfrag(from,
1571 page_address(pfrag->page) + pfrag->offset,
1572 offset, copy, skb->len, skb) < 0)
1573 goto error_efault;
1574
1575 pfrag->offset += copy;
1576 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
1577 skb->len += copy;
1578 skb->data_len += copy;
1579 skb->truesize += copy;
1580 refcount_add(copy, &sk->sk_wmem_alloc);
1581 }
1582 offset += copy;
1583 length -= copy;
1584 }
1585
1586 return 0;
1587
1588 error_efault:
1589 err = -EFAULT;
1590 error:
1591 cork->length -= length;
1592 IP6_INC_STATS(sock_net(sk), rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS);
1593 return err;
1594 }
1595
1596 int ip6_append_data(struct sock *sk,
1597 int getfrag(void *from, char *to, int offset, int len,
1598 int odd, struct sk_buff *skb),
1599 void *from, int length, int transhdrlen,
1600 struct ipcm6_cookie *ipc6, struct flowi6 *fl6,
1601 struct rt6_info *rt, unsigned int flags,
1602 const struct sockcm_cookie *sockc)
1603 {
1604 struct inet_sock *inet = inet_sk(sk);
1605 struct ipv6_pinfo *np = inet6_sk(sk);
1606 int exthdrlen;
1607 int err;
1608
1609 if (flags&MSG_PROBE)
1610 return 0;
1611 if (skb_queue_empty(&sk->sk_write_queue)) {
1612 /*
1613 * setup for corking
1614 */
1615 err = ip6_setup_cork(sk, &inet->cork, &np->cork,
1616 ipc6, rt, fl6);
1617 if (err)
1618 return err;
1619
1620 exthdrlen = (ipc6->opt ? ipc6->opt->opt_flen : 0);
1621 length += exthdrlen;
1622 transhdrlen += exthdrlen;
1623 } else {
1624 fl6 = &inet->cork.fl.u.ip6;
1625 transhdrlen = 0;
1626 }
1627
1628 return __ip6_append_data(sk, fl6, &sk->sk_write_queue, &inet->cork.base,
1629 &np->cork, sk_page_frag(sk), getfrag,
1630 from, length, transhdrlen, flags, ipc6, sockc);
1631 }
1632 EXPORT_SYMBOL_GPL(ip6_append_data);
1633
1634 static void ip6_cork_release(struct inet_cork_full *cork,
1635 struct inet6_cork *v6_cork)
1636 {
1637 if (v6_cork->opt) {
1638 kfree(v6_cork->opt->dst0opt);
1639 kfree(v6_cork->opt->dst1opt);
1640 kfree(v6_cork->opt->hopopt);
1641 kfree(v6_cork->opt->srcrt);
1642 kfree(v6_cork->opt);
1643 v6_cork->opt = NULL;
1644 }
1645
1646 if (cork->base.dst) {
1647 dst_release(cork->base.dst);
1648 cork->base.dst = NULL;
1649 cork->base.flags &= ~IPCORK_ALLFRAG;
1650 }
1651 memset(&cork->fl, 0, sizeof(cork->fl));
1652 }
1653
1654 struct sk_buff *__ip6_make_skb(struct sock *sk,
1655 struct sk_buff_head *queue,
1656 struct inet_cork_full *cork,
1657 struct inet6_cork *v6_cork)
1658 {
1659 struct sk_buff *skb, *tmp_skb;
1660 struct sk_buff **tail_skb;
1661 struct in6_addr final_dst_buf, *final_dst = &final_dst_buf;
1662 struct ipv6_pinfo *np = inet6_sk(sk);
1663 struct net *net = sock_net(sk);
1664 struct ipv6hdr *hdr;
1665 struct ipv6_txoptions *opt = v6_cork->opt;
1666 struct rt6_info *rt = (struct rt6_info *)cork->base.dst;
1667 struct flowi6 *fl6 = &cork->fl.u.ip6;
1668 unsigned char proto = fl6->flowi6_proto;
1669
1670 skb = __skb_dequeue(queue);
1671 if (!skb)
1672 goto out;
1673 tail_skb = &(skb_shinfo(skb)->frag_list);
1674
1675 /* move skb->data to ip header from ext header */
1676 if (skb->data < skb_network_header(skb))
1677 __skb_pull(skb, skb_network_offset(skb));
1678 while ((tmp_skb = __skb_dequeue(queue)) != NULL) {
1679 __skb_pull(tmp_skb, skb_network_header_len(skb));
1680 *tail_skb = tmp_skb;
1681 tail_skb = &(tmp_skb->next);
1682 skb->len += tmp_skb->len;
1683 skb->data_len += tmp_skb->len;
1684 skb->truesize += tmp_skb->truesize;
1685 tmp_skb->destructor = NULL;
1686 tmp_skb->sk = NULL;
1687 }
1688
1689 /* Allow local fragmentation. */
1690 skb->ignore_df = ip6_sk_ignore_df(sk);
1691
1692 *final_dst = fl6->daddr;
1693 __skb_pull(skb, skb_network_header_len(skb));
1694 if (opt && opt->opt_flen)
1695 ipv6_push_frag_opts(skb, opt, &proto);
1696 if (opt && opt->opt_nflen)
1697 ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst, &fl6->saddr);
1698
1699 skb_push(skb, sizeof(struct ipv6hdr));
1700 skb_reset_network_header(skb);
1701 hdr = ipv6_hdr(skb);
1702
1703 ip6_flow_hdr(hdr, v6_cork->tclass,
1704 ip6_make_flowlabel(net, skb, fl6->flowlabel,
1705 np->autoflowlabel, fl6));
1706 hdr->hop_limit = v6_cork->hop_limit;
1707 hdr->nexthdr = proto;
1708 hdr->saddr = fl6->saddr;
1709 hdr->daddr = *final_dst;
1710
1711 skb->priority = sk->sk_priority;
1712 skb->mark = sk->sk_mark;
1713
1714 skb_dst_set(skb, dst_clone(&rt->dst));
1715 IP6_UPD_PO_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUT, skb->len);
1716 if (proto == IPPROTO_ICMPV6) {
1717 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
1718
1719 ICMP6MSGOUT_INC_STATS(net, idev, icmp6_hdr(skb)->icmp6_type);
1720 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
1721 }
1722
1723 ip6_cork_release(cork, v6_cork);
1724 out:
1725 return skb;
1726 }
1727
1728 int ip6_send_skb(struct sk_buff *skb)
1729 {
1730 struct net *net = sock_net(skb->sk);
1731 struct rt6_info *rt = (struct rt6_info *)skb_dst(skb);
1732 int err;
1733
1734 err = ip6_local_out(net, skb->sk, skb);
1735 if (err) {
1736 if (err > 0)
1737 err = net_xmit_errno(err);
1738 if (err)
1739 IP6_INC_STATS(net, rt->rt6i_idev,
1740 IPSTATS_MIB_OUTDISCARDS);
1741 }
1742
1743 return err;
1744 }
1745
1746 int ip6_push_pending_frames(struct sock *sk)
1747 {
1748 struct sk_buff *skb;
1749
1750 skb = ip6_finish_skb(sk);
1751 if (!skb)
1752 return 0;
1753
1754 return ip6_send_skb(skb);
1755 }
1756 EXPORT_SYMBOL_GPL(ip6_push_pending_frames);
1757
1758 static void __ip6_flush_pending_frames(struct sock *sk,
1759 struct sk_buff_head *queue,
1760 struct inet_cork_full *cork,
1761 struct inet6_cork *v6_cork)
1762 {
1763 struct sk_buff *skb;
1764
1765 while ((skb = __skb_dequeue_tail(queue)) != NULL) {
1766 if (skb_dst(skb))
1767 IP6_INC_STATS(sock_net(sk), ip6_dst_idev(skb_dst(skb)),
1768 IPSTATS_MIB_OUTDISCARDS);
1769 kfree_skb(skb);
1770 }
1771
1772 ip6_cork_release(cork, v6_cork);
1773 }
1774
1775 void ip6_flush_pending_frames(struct sock *sk)
1776 {
1777 __ip6_flush_pending_frames(sk, &sk->sk_write_queue,
1778 &inet_sk(sk)->cork, &inet6_sk(sk)->cork);
1779 }
1780 EXPORT_SYMBOL_GPL(ip6_flush_pending_frames);
1781
1782 struct sk_buff *ip6_make_skb(struct sock *sk,
1783 int getfrag(void *from, char *to, int offset,
1784 int len, int odd, struct sk_buff *skb),
1785 void *from, int length, int transhdrlen,
1786 struct ipcm6_cookie *ipc6, struct flowi6 *fl6,
1787 struct rt6_info *rt, unsigned int flags,
1788 const struct sockcm_cookie *sockc)
1789 {
1790 struct inet_cork_full cork;
1791 struct inet6_cork v6_cork;
1792 struct sk_buff_head queue;
1793 int exthdrlen = (ipc6->opt ? ipc6->opt->opt_flen : 0);
1794 int err;
1795
1796 if (flags & MSG_PROBE)
1797 return NULL;
1798
1799 __skb_queue_head_init(&queue);
1800
1801 cork.base.flags = 0;
1802 cork.base.addr = 0;
1803 cork.base.opt = NULL;
1804 v6_cork.opt = NULL;
1805 err = ip6_setup_cork(sk, &cork, &v6_cork, ipc6, rt, fl6);
1806 if (err)
1807 return ERR_PTR(err);
1808
1809 if (ipc6->dontfrag < 0)
1810 ipc6->dontfrag = inet6_sk(sk)->dontfrag;
1811
1812 err = __ip6_append_data(sk, fl6, &queue, &cork.base, &v6_cork,
1813 &current->task_frag, getfrag, from,
1814 length + exthdrlen, transhdrlen + exthdrlen,
1815 flags, ipc6, sockc);
1816 if (err) {
1817 __ip6_flush_pending_frames(sk, &queue, &cork, &v6_cork);
1818 return ERR_PTR(err);
1819 }
1820
1821 return __ip6_make_skb(sk, &queue, &cork, &v6_cork);
1822 }
Ubuntu Artful kernel mirror