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