1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * IPv6 output functions
4 * Linux INET6 implementation
5 *
6 * Authors:
7 * Pedro Roque <roque@di.fc.ul.pt>
8 *
9 * Based on linux/net/ipv4/ip_output.c
10 *
11 * Changes:
12 * A.N.Kuznetsov : airthmetics in fragmentation.
13 * extension headers are implemented.
14 * route changes now work.
15 * ip6_forward does not confuse sniffers.
16 * etc.
17 *
18 * H. von Brand : Added missing #include <linux/string.h>
19 * Imran Patel : frag id should be in NBO
20 * Kazunori MIYAZAWA @USAGI
21 * : add ip6_append_data and related functions
22 * for datagram xmit
23 */
24
25 #include <linux/errno.h>
26 #include <linux/kernel.h>
27 #include <linux/string.h>
28 #include <linux/socket.h>
29 #include <linux/net.h>
30 #include <linux/netdevice.h>
31 #include <linux/if_arp.h>
32 #include <linux/in6.h>
33 #include <linux/tcp.h>
34 #include <linux/route.h>
35 #include <linux/module.h>
36 #include <linux/slab.h>
37
38 #include <linux/bpf-cgroup.h>
39 #include <linux/netfilter.h>
40 #include <linux/netfilter_ipv6.h>
41
42 #include <net/sock.h>
43 #include <net/snmp.h>
44
45 #include <net/ipv6.h>
46 #include <net/ndisc.h>
47 #include <net/protocol.h>
48 #include <net/ip6_route.h>
49 #include <net/addrconf.h>
50 #include <net/rawv6.h>
51 #include <net/icmp.h>
52 #include <net/xfrm.h>
53 #include <net/checksum.h>
54 #include <linux/mroute6.h>
55 #include <net/l3mdev.h>
56 #include <net/lwtunnel.h>
57
ip6_finish_output2(struct net * net,struct sock * sk,struct sk_buff * skb)58 static int ip6_finish_output2(struct net *net, struct sock *sk, struct sk_buff *skb)
59 {
60 struct dst_entry *dst = skb_dst(skb);
61 struct net_device *dev = dst->dev;
62 const struct in6_addr *nexthop;
63 struct neighbour *neigh;
64 int ret;
65
66 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) {
67 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
68
69 if (!(dev->flags & IFF_LOOPBACK) && sk_mc_loop(sk) &&
70 ((mroute6_is_socket(net, skb) &&
71 !(IP6CB(skb)->flags & IP6SKB_FORWARDED)) ||
72 ipv6_chk_mcast_addr(dev, &ipv6_hdr(skb)->daddr,
73 &ipv6_hdr(skb)->saddr))) {
74 struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC);
75
76 /* Do not check for IFF_ALLMULTI; multicast routing
77 is not supported in any case.
78 */
79 if (newskb)
80 NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING,
81 net, sk, newskb, NULL, newskb->dev,
82 dev_loopback_xmit);
83
84 if (ipv6_hdr(skb)->hop_limit == 0) {
85 IP6_INC_STATS(net, idev,
86 IPSTATS_MIB_OUTDISCARDS);
87 kfree_skb(skb);
88 return 0;
89 }
90 }
91
92 IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUTMCAST, skb->len);
93
94 if (IPV6_ADDR_MC_SCOPE(&ipv6_hdr(skb)->daddr) <=
95 IPV6_ADDR_SCOPE_NODELOCAL &&
96 !(dev->flags & IFF_LOOPBACK)) {
97 kfree_skb(skb);
98 return 0;
99 }
100 }
101
102 if (lwtunnel_xmit_redirect(dst->lwtstate)) {
103 int res = lwtunnel_xmit(skb);
104
105 if (res < 0 || res == LWTUNNEL_XMIT_DONE)
106 return res;
107 }
108
109 rcu_read_lock_bh();
110 nexthop = rt6_nexthop((struct rt6_info *)dst, &ipv6_hdr(skb)->daddr);
111 neigh = __ipv6_neigh_lookup_noref(dst->dev, nexthop);
112 if (unlikely(!neigh))
113 neigh = __neigh_create(&nd_tbl, nexthop, dst->dev, false);
114 if (!IS_ERR(neigh)) {
115 sock_confirm_neigh(skb, neigh);
116 ret = neigh_output(neigh, skb, false);
117 rcu_read_unlock_bh();
118 return ret;
119 }
120 rcu_read_unlock_bh();
121
122 IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
123 kfree_skb(skb);
124 return -EINVAL;
125 }
126
__ip6_finish_output(struct net * net,struct sock * sk,struct sk_buff * skb)127 static int __ip6_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb)
128 {
129 #if defined(CONFIG_NETFILTER) && defined(CONFIG_XFRM)
130 /* Policy lookup after SNAT yielded a new policy */
131 if (skb_dst(skb)->xfrm) {
132 IPCB(skb)->flags |= IPSKB_REROUTED;
133 return dst_output(net, sk, skb);
134 }
135 #endif
136
137 if ((skb->len > ip6_skb_dst_mtu(skb) && !skb_is_gso(skb)) ||
138 dst_allfrag(skb_dst(skb)) ||
139 (IP6CB(skb)->frag_max_size && skb->len > IP6CB(skb)->frag_max_size))
140 return ip6_fragment(net, sk, skb, ip6_finish_output2);
141 else
142 return ip6_finish_output2(net, sk, skb);
143 }
144
ip6_finish_output(struct net * net,struct sock * sk,struct sk_buff * skb)145 static int ip6_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb)
146 {
147 int ret;
148
149 ret = BPF_CGROUP_RUN_PROG_INET_EGRESS(sk, skb);
150 switch (ret) {
151 case NET_XMIT_SUCCESS:
152 return __ip6_finish_output(net, sk, skb);
153 case NET_XMIT_CN:
154 return __ip6_finish_output(net, sk, skb) ? : ret;
155 default:
156 kfree_skb(skb);
157 return ret;
158 }
159 }
160
ip6_output(struct net * net,struct sock * sk,struct sk_buff * skb)161 int ip6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
162 {
163 struct net_device *dev = skb_dst(skb)->dev;
164 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
165
166 skb->protocol = htons(ETH_P_IPV6);
167 skb->dev = dev;
168
169 if (unlikely(idev->cnf.disable_ipv6)) {
170 IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTDISCARDS);
171 kfree_skb(skb);
172 return 0;
173 }
174
175 return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING,
176 net, sk, skb, NULL, dev,
177 ip6_finish_output,
178 !(IP6CB(skb)->flags & IP6SKB_REROUTED));
179 }
180
ip6_autoflowlabel(struct net * net,const struct ipv6_pinfo * np)181 bool ip6_autoflowlabel(struct net *net, const struct ipv6_pinfo *np)
182 {
183 if (!np->autoflowlabel_set)
184 return ip6_default_np_autolabel(net);
185 else
186 return np->autoflowlabel;
187 }
188
189 /*
190 * xmit an sk_buff (used by TCP, SCTP and DCCP)
191 * Note : socket lock is not held for SYNACK packets, but might be modified
192 * by calls to skb_set_owner_w() and ipv6_local_error(),
193 * which are using proper atomic operations or spinlocks.
194 */
ip6_xmit(const struct sock * sk,struct sk_buff * skb,struct flowi6 * fl6,__u32 mark,struct ipv6_txoptions * opt,int tclass,u32 priority)195 int ip6_xmit(const struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
196 __u32 mark, struct ipv6_txoptions *opt, int tclass, u32 priority)
197 {
198 struct net *net = sock_net(sk);
199 const struct ipv6_pinfo *np = inet6_sk(sk);
200 struct in6_addr *first_hop = &fl6->daddr;
201 struct dst_entry *dst = skb_dst(skb);
202 unsigned int head_room;
203 struct ipv6hdr *hdr;
204 u8 proto = fl6->flowi6_proto;
205 int seg_len = skb->len;
206 int hlimit = -1;
207 u32 mtu;
208
209 head_room = sizeof(struct ipv6hdr) + LL_RESERVED_SPACE(dst->dev);
210 if (opt)
211 head_room += opt->opt_nflen + opt->opt_flen;
212
213 if (unlikely(skb_headroom(skb) < head_room)) {
214 struct sk_buff *skb2 = skb_realloc_headroom(skb, head_room);
215 if (!skb2) {
216 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
217 IPSTATS_MIB_OUTDISCARDS);
218 kfree_skb(skb);
219 return -ENOBUFS;
220 }
221 if (skb->sk)
222 skb_set_owner_w(skb2, skb->sk);
223 consume_skb(skb);
224 skb = skb2;
225 }
226
227 if (opt) {
228 seg_len += opt->opt_nflen + opt->opt_flen;
229
230 if (opt->opt_flen)
231 ipv6_push_frag_opts(skb, opt, &proto);
232
233 if (opt->opt_nflen)
234 ipv6_push_nfrag_opts(skb, opt, &proto, &first_hop,
235 &fl6->saddr);
236 }
237
238 skb_push(skb, sizeof(struct ipv6hdr));
239 skb_reset_network_header(skb);
240 hdr = ipv6_hdr(skb);
241
242 /*
243 * Fill in the IPv6 header
244 */
245 if (np)
246 hlimit = np->hop_limit;
247 if (hlimit < 0)
248 hlimit = ip6_dst_hoplimit(dst);
249
250 ip6_flow_hdr(hdr, tclass, ip6_make_flowlabel(net, skb, fl6->flowlabel,
251 ip6_autoflowlabel(net, np), fl6));
252
253 hdr->payload_len = htons(seg_len);
254 hdr->nexthdr = proto;
255 hdr->hop_limit = hlimit;
256
257 hdr->saddr = fl6->saddr;
258 hdr->daddr = *first_hop;
259
260 skb->protocol = htons(ETH_P_IPV6);
261 skb->priority = priority;
262 skb->mark = mark;
263
264 mtu = dst_mtu(dst);
265 if ((skb->len <= mtu) || skb->ignore_df || skb_is_gso(skb)) {
266 IP6_UPD_PO_STATS(net, ip6_dst_idev(skb_dst(skb)),
267 IPSTATS_MIB_OUT, skb->len);
268
269 /* if egress device is enslaved to an L3 master device pass the
270 * skb to its handler for processing
271 */
272 skb = l3mdev_ip6_out((struct sock *)sk, skb);
273 if (unlikely(!skb))
274 return 0;
275
276 /* hooks should never assume socket lock is held.
277 * we promote our socket to non const
278 */
279 return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
280 net, (struct sock *)sk, skb, NULL, dst->dev,
281 dst_output);
282 }
283
284 skb->dev = dst->dev;
285 /* ipv6_local_error() does not require socket lock,
286 * we promote our socket to non const
287 */
288 ipv6_local_error((struct sock *)sk, EMSGSIZE, fl6, mtu);
289
290 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_FRAGFAILS);
291 kfree_skb(skb);
292 return -EMSGSIZE;
293 }
294 EXPORT_SYMBOL(ip6_xmit);
295
ip6_call_ra_chain(struct sk_buff * skb,int sel)296 static int ip6_call_ra_chain(struct sk_buff *skb, int sel)
297 {
298 struct ip6_ra_chain *ra;
299 struct sock *last = NULL;
300
301 read_lock(&ip6_ra_lock);
302 for (ra = ip6_ra_chain; ra; ra = ra->next) {
303 struct sock *sk = ra->sk;
304 if (sk && ra->sel == sel &&
305 (!sk->sk_bound_dev_if ||
306 sk->sk_bound_dev_if == skb->dev->ifindex)) {
307 struct ipv6_pinfo *np = inet6_sk(sk);
308
309 if (np && np->rtalert_isolate &&
310 !net_eq(sock_net(sk), dev_net(skb->dev))) {
311 continue;
312 }
313 if (last) {
314 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
315 if (skb2)
316 rawv6_rcv(last, skb2);
317 }
318 last = sk;
319 }
320 }
321
322 if (last) {
323 rawv6_rcv(last, skb);
324 read_unlock(&ip6_ra_lock);
325 return 1;
326 }
327 read_unlock(&ip6_ra_lock);
328 return 0;
329 }
330
ip6_forward_proxy_check(struct sk_buff * skb)331 static int ip6_forward_proxy_check(struct sk_buff *skb)
332 {
333 struct ipv6hdr *hdr = ipv6_hdr(skb);
334 u8 nexthdr = hdr->nexthdr;
335 __be16 frag_off;
336 int offset;
337
338 if (ipv6_ext_hdr(nexthdr)) {
339 offset = ipv6_skip_exthdr(skb, sizeof(*hdr), &nexthdr, &frag_off);
340 if (offset < 0)
341 return 0;
342 } else
343 offset = sizeof(struct ipv6hdr);
344
345 if (nexthdr == IPPROTO_ICMPV6) {
346 struct icmp6hdr *icmp6;
347
348 if (!pskb_may_pull(skb, (skb_network_header(skb) +
349 offset + 1 - skb->data)))
350 return 0;
351
352 icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset);
353
354 switch (icmp6->icmp6_type) {
355 case NDISC_ROUTER_SOLICITATION:
356 case NDISC_ROUTER_ADVERTISEMENT:
357 case NDISC_NEIGHBOUR_SOLICITATION:
358 case NDISC_NEIGHBOUR_ADVERTISEMENT:
359 case NDISC_REDIRECT:
360 /* For reaction involving unicast neighbor discovery
361 * message destined to the proxied address, pass it to
362 * input function.
363 */
364 return 1;
365 default:
366 break;
367 }
368 }
369
370 /*
371 * The proxying router can't forward traffic sent to a link-local
372 * address, so signal the sender and discard the packet. This
373 * behavior is clarified by the MIPv6 specification.
374 */
375 if (ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) {
376 dst_link_failure(skb);
377 return -1;
378 }
379
380 return 0;
381 }
382
ip6_forward_finish(struct net * net,struct sock * sk,struct sk_buff * skb)383 static inline int ip6_forward_finish(struct net *net, struct sock *sk,
384 struct sk_buff *skb)
385 {
386 struct dst_entry *dst = skb_dst(skb);
387
388 __IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTFORWDATAGRAMS);
389 __IP6_ADD_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTOCTETS, skb->len);
390
391 #ifdef CONFIG_NET_SWITCHDEV
392 if (skb->offload_l3_fwd_mark) {
393 consume_skb(skb);
394 return 0;
395 }
396 #endif
397
398 skb->tstamp = 0;
399 return dst_output(net, sk, skb);
400 }
401
ip6_pkt_too_big(const struct sk_buff * skb,unsigned int mtu)402 static bool ip6_pkt_too_big(const struct sk_buff *skb, unsigned int mtu)
403 {
404 if (skb->len <= mtu)
405 return false;
406
407 /* ipv6 conntrack defrag sets max_frag_size + ignore_df */
408 if (IP6CB(skb)->frag_max_size && IP6CB(skb)->frag_max_size > mtu)
409 return true;
410
411 if (skb->ignore_df)
412 return false;
413
414 if (skb_is_gso(skb) && skb_gso_validate_network_len(skb, mtu))
415 return false;
416
417 return true;
418 }
419
ip6_forward(struct sk_buff * skb)420 int ip6_forward(struct sk_buff *skb)
421 {
422 struct inet6_dev *idev = __in6_dev_get_safely(skb->dev);
423 struct dst_entry *dst = skb_dst(skb);
424 struct ipv6hdr *hdr = ipv6_hdr(skb);
425 struct inet6_skb_parm *opt = IP6CB(skb);
426 struct net *net = dev_net(dst->dev);
427 u32 mtu;
428
429 if (net->ipv6.devconf_all->forwarding == 0)
430 goto error;
431
432 if (skb->pkt_type != PACKET_HOST)
433 goto drop;
434
435 if (unlikely(skb->sk))
436 goto drop;
437
438 if (skb_warn_if_lro(skb))
439 goto drop;
440
441 if (!xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) {
442 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS);
443 goto drop;
444 }
445
446 skb_forward_csum(skb);
447
448 /*
449 * We DO NOT make any processing on
450 * RA packets, pushing them to user level AS IS
451 * without ane WARRANTY that application will be able
452 * to interpret them. The reason is that we
453 * cannot make anything clever here.
454 *
455 * We are not end-node, so that if packet contains
456 * AH/ESP, we cannot make anything.
457 * Defragmentation also would be mistake, RA packets
458 * cannot be fragmented, because there is no warranty
459 * that different fragments will go along one path. --ANK
460 */
461 if (unlikely(opt->flags & IP6SKB_ROUTERALERT)) {
462 if (ip6_call_ra_chain(skb, ntohs(opt->ra)))
463 return 0;
464 }
465
466 /*
467 * check and decrement ttl
468 */
469 if (hdr->hop_limit <= 1) {
470 /* Force OUTPUT device used as source address */
471 skb->dev = dst->dev;
472 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 0);
473 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
474
475 kfree_skb(skb);
476 return -ETIMEDOUT;
477 }
478
479 /* XXX: idev->cnf.proxy_ndp? */
480 if (net->ipv6.devconf_all->proxy_ndp &&
481 pneigh_lookup(&nd_tbl, net, &hdr->daddr, skb->dev, 0)) {
482 int proxied = ip6_forward_proxy_check(skb);
483 if (proxied > 0)
484 return ip6_input(skb);
485 else if (proxied < 0) {
486 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS);
487 goto drop;
488 }
489 }
490
491 if (!xfrm6_route_forward(skb)) {
492 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS);
493 goto drop;
494 }
495 dst = skb_dst(skb);
496
497 /* IPv6 specs say nothing about it, but it is clear that we cannot
498 send redirects to source routed frames.
499 We don't send redirects to frames decapsulated from IPsec.
500 */
501 if (IP6CB(skb)->iif == dst->dev->ifindex &&
502 opt->srcrt == 0 && !skb_sec_path(skb)) {
503 struct in6_addr *target = NULL;
504 struct inet_peer *peer;
505 struct rt6_info *rt;
506
507 /*
508 * incoming and outgoing devices are the same
509 * send a redirect.
510 */
511
512 rt = (struct rt6_info *) dst;
513 if (rt->rt6i_flags & RTF_GATEWAY)
514 target = &rt->rt6i_gateway;
515 else
516 target = &hdr->daddr;
517
518 peer = inet_getpeer_v6(net->ipv6.peers, &hdr->daddr, 1);
519
520 /* Limit redirects both by destination (here)
521 and by source (inside ndisc_send_redirect)
522 */
523 if (inet_peer_xrlim_allow(peer, 1*HZ))
524 ndisc_send_redirect(skb, target);
525 if (peer)
526 inet_putpeer(peer);
527 } else {
528 int addrtype = ipv6_addr_type(&hdr->saddr);
529
530 /* This check is security critical. */
531 if (addrtype == IPV6_ADDR_ANY ||
532 addrtype & (IPV6_ADDR_MULTICAST | IPV6_ADDR_LOOPBACK))
533 goto error;
534 if (addrtype & IPV6_ADDR_LINKLOCAL) {
535 icmpv6_send(skb, ICMPV6_DEST_UNREACH,
536 ICMPV6_NOT_NEIGHBOUR, 0);
537 goto error;
538 }
539 }
540
541 mtu = ip6_dst_mtu_forward(dst);
542 if (mtu < IPV6_MIN_MTU)
543 mtu = IPV6_MIN_MTU;
544
545 if (ip6_pkt_too_big(skb, mtu)) {
546 /* Again, force OUTPUT device used as source address */
547 skb->dev = dst->dev;
548 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
549 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INTOOBIGERRORS);
550 __IP6_INC_STATS(net, ip6_dst_idev(dst),
551 IPSTATS_MIB_FRAGFAILS);
552 kfree_skb(skb);
553 return -EMSGSIZE;
554 }
555
556 if (skb_cow(skb, dst->dev->hard_header_len)) {
557 __IP6_INC_STATS(net, ip6_dst_idev(dst),
558 IPSTATS_MIB_OUTDISCARDS);
559 goto drop;
560 }
561
562 hdr = ipv6_hdr(skb);
563
564 /* Mangling hops number delayed to point after skb COW */
565
566 hdr->hop_limit--;
567
568 return NF_HOOK(NFPROTO_IPV6, NF_INET_FORWARD,
569 net, NULL, skb, skb->dev, dst->dev,
570 ip6_forward_finish);
571
572 error:
573 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
574 drop:
575 kfree_skb(skb);
576 return -EINVAL;
577 }
578
ip6_copy_metadata(struct sk_buff * to,struct sk_buff * from)579 static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from)
580 {
581 to->pkt_type = from->pkt_type;
582 to->priority = from->priority;
583 to->protocol = from->protocol;
584 skb_dst_drop(to);
585 skb_dst_set(to, dst_clone(skb_dst(from)));
586 to->dev = from->dev;
587 to->mark = from->mark;
588
589 skb_copy_hash(to, from);
590
591 #ifdef CONFIG_NET_SCHED
592 to->tc_index = from->tc_index;
593 #endif
594 nf_copy(to, from);
595 skb_ext_copy(to, from);
596 skb_copy_secmark(to, from);
597 }
598
ip6_fraglist_init(struct sk_buff * skb,unsigned int hlen,u8 * prevhdr,u8 nexthdr,__be32 frag_id,struct ip6_fraglist_iter * iter)599 int ip6_fraglist_init(struct sk_buff *skb, unsigned int hlen, u8 *prevhdr,
600 u8 nexthdr, __be32 frag_id,
601 struct ip6_fraglist_iter *iter)
602 {
603 unsigned int first_len;
604 struct frag_hdr *fh;
605
606 /* BUILD HEADER */
607 *prevhdr = NEXTHDR_FRAGMENT;
608 iter->tmp_hdr = kmemdup(skb_network_header(skb), hlen, GFP_ATOMIC);
609 if (!iter->tmp_hdr)
610 return -ENOMEM;
611
612 iter->frag = skb_shinfo(skb)->frag_list;
613 skb_frag_list_init(skb);
614
615 iter->offset = 0;
616 iter->hlen = hlen;
617 iter->frag_id = frag_id;
618 iter->nexthdr = nexthdr;
619
620 __skb_pull(skb, hlen);
621 fh = __skb_push(skb, sizeof(struct frag_hdr));
622 __skb_push(skb, hlen);
623 skb_reset_network_header(skb);
624 memcpy(skb_network_header(skb), iter->tmp_hdr, hlen);
625
626 fh->nexthdr = nexthdr;
627 fh->reserved = 0;
628 fh->frag_off = htons(IP6_MF);
629 fh->identification = frag_id;
630
631 first_len = skb_pagelen(skb);
632 skb->data_len = first_len - skb_headlen(skb);
633 skb->len = first_len;
634 ipv6_hdr(skb)->payload_len = htons(first_len - sizeof(struct ipv6hdr));
635
636 return 0;
637 }
638 EXPORT_SYMBOL(ip6_fraglist_init);
639
ip6_fraglist_prepare(struct sk_buff * skb,struct ip6_fraglist_iter * iter)640 void ip6_fraglist_prepare(struct sk_buff *skb,
641 struct ip6_fraglist_iter *iter)
642 {
643 struct sk_buff *frag = iter->frag;
644 unsigned int hlen = iter->hlen;
645 struct frag_hdr *fh;
646
647 frag->ip_summed = CHECKSUM_NONE;
648 skb_reset_transport_header(frag);
649 fh = __skb_push(frag, sizeof(struct frag_hdr));
650 __skb_push(frag, hlen);
651 skb_reset_network_header(frag);
652 memcpy(skb_network_header(frag), iter->tmp_hdr, hlen);
653 iter->offset += skb->len - hlen - sizeof(struct frag_hdr);
654 fh->nexthdr = iter->nexthdr;
655 fh->reserved = 0;
656 fh->frag_off = htons(iter->offset);
657 if (frag->next)
658 fh->frag_off |= htons(IP6_MF);
659 fh->identification = iter->frag_id;
660 ipv6_hdr(frag)->payload_len = htons(frag->len - sizeof(struct ipv6hdr));
661 ip6_copy_metadata(frag, skb);
662 }
663 EXPORT_SYMBOL(ip6_fraglist_prepare);
664
ip6_frag_init(struct sk_buff * skb,unsigned int hlen,unsigned int mtu,unsigned short needed_tailroom,int hdr_room,u8 * prevhdr,u8 nexthdr,__be32 frag_id,struct ip6_frag_state * state)665 void ip6_frag_init(struct sk_buff *skb, unsigned int hlen, unsigned int mtu,
666 unsigned short needed_tailroom, int hdr_room, u8 *prevhdr,
667 u8 nexthdr, __be32 frag_id, struct ip6_frag_state *state)
668 {
669 state->prevhdr = prevhdr;
670 state->nexthdr = nexthdr;
671 state->frag_id = frag_id;
672
673 state->hlen = hlen;
674 state->mtu = mtu;
675
676 state->left = skb->len - hlen; /* Space per frame */
677 state->ptr = hlen; /* Where to start from */
678
679 state->hroom = hdr_room;
680 state->troom = needed_tailroom;
681
682 state->offset = 0;
683 }
684 EXPORT_SYMBOL(ip6_frag_init);
685
ip6_frag_next(struct sk_buff * skb,struct ip6_frag_state * state)686 struct sk_buff *ip6_frag_next(struct sk_buff *skb, struct ip6_frag_state *state)
687 {
688 u8 *prevhdr = state->prevhdr, *fragnexthdr_offset;
689 struct sk_buff *frag;
690 struct frag_hdr *fh;
691 unsigned int len;
692
693 len = state->left;
694 /* IF: it doesn't fit, use 'mtu' - the data space left */
695 if (len > state->mtu)
696 len = state->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 < state->left)
700 len &= ~7;
701
702 /* Allocate buffer */
703 frag = alloc_skb(len + state->hlen + sizeof(struct frag_hdr) +
704 state->hroom + state->troom, GFP_ATOMIC);
705 if (!frag)
706 return ERR_PTR(-ENOMEM);
707
708 /*
709 * Set up data on packet
710 */
711
712 ip6_copy_metadata(frag, skb);
713 skb_reserve(frag, state->hroom);
714 skb_put(frag, len + state->hlen + sizeof(struct frag_hdr));
715 skb_reset_network_header(frag);
716 fh = (struct frag_hdr *)(skb_network_header(frag) + state->hlen);
717 frag->transport_header = (frag->network_header + state->hlen +
718 sizeof(struct frag_hdr));
719
720 /*
721 * Charge the memory for the fragment to any owner
722 * it might possess
723 */
724 if (skb->sk)
725 skb_set_owner_w(frag, skb->sk);
726
727 /*
728 * Copy the packet header into the new buffer.
729 */
730 skb_copy_from_linear_data(skb, skb_network_header(frag), state->hlen);
731
732 fragnexthdr_offset = skb_network_header(frag);
733 fragnexthdr_offset += prevhdr - skb_network_header(skb);
734 *fragnexthdr_offset = NEXTHDR_FRAGMENT;
735
736 /*
737 * Build fragment header.
738 */
739 fh->nexthdr = state->nexthdr;
740 fh->reserved = 0;
741 fh->identification = state->frag_id;
742
743 /*
744 * Copy a block of the IP datagram.
745 */
746 BUG_ON(skb_copy_bits(skb, state->ptr, skb_transport_header(frag),
747 len));
748 state->left -= len;
749
750 fh->frag_off = htons(state->offset);
751 if (state->left > 0)
752 fh->frag_off |= htons(IP6_MF);
753 ipv6_hdr(frag)->payload_len = htons(frag->len - sizeof(struct ipv6hdr));
754
755 state->ptr += len;
756 state->offset += len;
757
758 return frag;
759 }
760 EXPORT_SYMBOL(ip6_frag_next);
761
ip6_fragment(struct net * net,struct sock * sk,struct sk_buff * skb,int (* output)(struct net *,struct sock *,struct sk_buff *))762 int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
763 int (*output)(struct net *, struct sock *, struct sk_buff *))
764 {
765 struct sk_buff *frag;
766 struct rt6_info *rt = (struct rt6_info *)skb_dst(skb);
767 struct ipv6_pinfo *np = skb->sk && !dev_recursion_level() ?
768 inet6_sk(skb->sk) : NULL;
769 struct ip6_frag_state state;
770 unsigned int mtu, hlen, nexthdr_offset;
771 ktime_t tstamp = skb->tstamp;
772 int hroom, err = 0;
773 __be32 frag_id;
774 u8 *prevhdr, nexthdr = 0;
775
776 err = ip6_find_1stfragopt(skb, &prevhdr);
777 if (err < 0)
778 goto fail;
779 hlen = err;
780 nexthdr = *prevhdr;
781 nexthdr_offset = prevhdr - skb_network_header(skb);
782
783 mtu = ip6_skb_dst_mtu(skb);
784
785 /* We must not fragment if the socket is set to force MTU discovery
786 * or if the skb it not generated by a local socket.
787 */
788 if (unlikely(!skb->ignore_df && skb->len > mtu))
789 goto fail_toobig;
790
791 if (IP6CB(skb)->frag_max_size) {
792 if (IP6CB(skb)->frag_max_size > mtu)
793 goto fail_toobig;
794
795 /* don't send fragments larger than what we received */
796 mtu = IP6CB(skb)->frag_max_size;
797 if (mtu < IPV6_MIN_MTU)
798 mtu = IPV6_MIN_MTU;
799 }
800
801 if (np && np->frag_size < mtu) {
802 if (np->frag_size)
803 mtu = np->frag_size;
804 }
805 if (mtu < hlen + sizeof(struct frag_hdr) + 8)
806 goto fail_toobig;
807 mtu -= hlen + sizeof(struct frag_hdr);
808
809 frag_id = ipv6_select_ident(net, &ipv6_hdr(skb)->daddr,
810 &ipv6_hdr(skb)->saddr);
811
812 if (skb->ip_summed == CHECKSUM_PARTIAL &&
813 (err = skb_checksum_help(skb)))
814 goto fail;
815
816 prevhdr = skb_network_header(skb) + nexthdr_offset;
817 hroom = LL_RESERVED_SPACE(rt->dst.dev);
818 if (skb_has_frag_list(skb)) {
819 unsigned int first_len = skb_pagelen(skb);
820 struct ip6_fraglist_iter iter;
821 struct sk_buff *frag2;
822
823 if (first_len - hlen > mtu ||
824 ((first_len - hlen) & 7) ||
825 skb_cloned(skb) ||
826 skb_headroom(skb) < (hroom + sizeof(struct frag_hdr)))
827 goto slow_path;
828
829 skb_walk_frags(skb, frag) {
830 /* Correct geometry. */
831 if (frag->len > mtu ||
832 ((frag->len & 7) && frag->next) ||
833 skb_headroom(frag) < (hlen + hroom + sizeof(struct frag_hdr)))
834 goto slow_path_clean;
835
836 /* Partially cloned skb? */
837 if (skb_shared(frag))
838 goto slow_path_clean;
839
840 BUG_ON(frag->sk);
841 if (skb->sk) {
842 frag->sk = skb->sk;
843 frag->destructor = sock_wfree;
844 }
845 skb->truesize -= frag->truesize;
846 }
847
848 err = ip6_fraglist_init(skb, hlen, prevhdr, nexthdr, frag_id,
849 &iter);
850 if (err < 0)
851 goto fail;
852
853 for (;;) {
854 /* Prepare header of the next frame,
855 * before previous one went down. */
856 if (iter.frag)
857 ip6_fraglist_prepare(skb, &iter);
858
859 skb->tstamp = tstamp;
860 err = output(net, sk, skb);
861 if (!err)
862 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
863 IPSTATS_MIB_FRAGCREATES);
864
865 if (err || !iter.frag)
866 break;
867
868 skb = ip6_fraglist_next(&iter);
869 }
870
871 kfree(iter.tmp_hdr);
872
873 if (err == 0) {
874 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
875 IPSTATS_MIB_FRAGOKS);
876 return 0;
877 }
878
879 kfree_skb_list(iter.frag);
880
881 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
882 IPSTATS_MIB_FRAGFAILS);
883 return err;
884
885 slow_path_clean:
886 skb_walk_frags(skb, frag2) {
887 if (frag2 == frag)
888 break;
889 frag2->sk = NULL;
890 frag2->destructor = NULL;
891 skb->truesize += frag2->truesize;
892 }
893 }
894
895 slow_path:
896 /*
897 * Fragment the datagram.
898 */
899
900 ip6_frag_init(skb, hlen, mtu, rt->dst.dev->needed_tailroom,
901 LL_RESERVED_SPACE(rt->dst.dev), prevhdr, nexthdr, frag_id,
902 &state);
903
904 /*
905 * Keep copying data until we run out.
906 */
907
908 while (state.left > 0) {
909 frag = ip6_frag_next(skb, &state);
910 if (IS_ERR(frag)) {
911 err = PTR_ERR(frag);
912 goto fail;
913 }
914
915 /*
916 * Put this fragment into the sending queue.
917 */
918 frag->tstamp = tstamp;
919 err = output(net, sk, frag);
920 if (err)
921 goto fail;
922
923 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
924 IPSTATS_MIB_FRAGCREATES);
925 }
926 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
927 IPSTATS_MIB_FRAGOKS);
928 consume_skb(skb);
929 return err;
930
931 fail_toobig:
932 if (skb->sk && dst_allfrag(skb_dst(skb)))
933 sk_nocaps_add(skb->sk, NETIF_F_GSO_MASK);
934
935 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
936 err = -EMSGSIZE;
937
938 fail:
939 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
940 IPSTATS_MIB_FRAGFAILS);
941 kfree_skb(skb);
942 return err;
943 }
944
ip6_rt_check(const struct rt6key * rt_key,const struct in6_addr * fl_addr,const struct in6_addr * addr_cache)945 static inline int ip6_rt_check(const struct rt6key *rt_key,
946 const struct in6_addr *fl_addr,
947 const struct in6_addr *addr_cache)
948 {
949 return (rt_key->plen != 128 || !ipv6_addr_equal(fl_addr, &rt_key->addr)) &&
950 (!addr_cache || !ipv6_addr_equal(fl_addr, addr_cache));
951 }
952
ip6_sk_dst_check(struct sock * sk,struct dst_entry * dst,const struct flowi6 * fl6)953 static struct dst_entry *ip6_sk_dst_check(struct sock *sk,
954 struct dst_entry *dst,
955 const struct flowi6 *fl6)
956 {
957 struct ipv6_pinfo *np = inet6_sk(sk);
958 struct rt6_info *rt;
959
960 if (!dst)
961 goto out;
962
963 if (dst->ops->family != AF_INET6) {
964 dst_release(dst);
965 return NULL;
966 }
967
968 rt = (struct rt6_info *)dst;
969 /* Yes, checking route validity in not connected
970 * case is not very simple. Take into account,
971 * that we do not support routing by source, TOS,
972 * and MSG_DONTROUTE --ANK (980726)
973 *
974 * 1. ip6_rt_check(): If route was host route,
975 * check that cached destination is current.
976 * If it is network route, we still may
977 * check its validity using saved pointer
978 * to the last used address: daddr_cache.
979 * We do not want to save whole address now,
980 * (because main consumer of this service
981 * is tcp, which has not this problem),
982 * so that the last trick works only on connected
983 * sockets.
984 * 2. oif also should be the same.
985 */
986 if (ip6_rt_check(&rt->rt6i_dst, &fl6->daddr, np->daddr_cache) ||
987 #ifdef CONFIG_IPV6_SUBTREES
988 ip6_rt_check(&rt->rt6i_src, &fl6->saddr, np->saddr_cache) ||
989 #endif
990 (!(fl6->flowi6_flags & FLOWI_FLAG_SKIP_NH_OIF) &&
991 (fl6->flowi6_oif && fl6->flowi6_oif != dst->dev->ifindex))) {
992 dst_release(dst);
993 dst = NULL;
994 }
995
996 out:
997 return dst;
998 }
999
ip6_dst_lookup_tail(struct net * net,const struct sock * sk,struct dst_entry ** dst,struct flowi6 * fl6)1000 static int ip6_dst_lookup_tail(struct net *net, const struct sock *sk,
1001 struct dst_entry **dst, struct flowi6 *fl6)
1002 {
1003 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
1004 struct neighbour *n;
1005 struct rt6_info *rt;
1006 #endif
1007 int err;
1008 int flags = 0;
1009
1010 /* The correct way to handle this would be to do
1011 * ip6_route_get_saddr, and then ip6_route_output; however,
1012 * the route-specific preferred source forces the
1013 * ip6_route_output call _before_ ip6_route_get_saddr.
1014 *
1015 * In source specific routing (no src=any default route),
1016 * ip6_route_output will fail given src=any saddr, though, so
1017 * that's why we try it again later.
1018 */
1019 if (ipv6_addr_any(&fl6->saddr) && (!*dst || !(*dst)->error)) {
1020 struct fib6_info *from;
1021 struct rt6_info *rt;
1022 bool had_dst = *dst != NULL;
1023
1024 if (!had_dst)
1025 *dst = ip6_route_output(net, sk, fl6);
1026 rt = (*dst)->error ? NULL : (struct rt6_info *)*dst;
1027
1028 rcu_read_lock();
1029 from = rt ? rcu_dereference(rt->from) : NULL;
1030 err = ip6_route_get_saddr(net, from, &fl6->daddr,
1031 sk ? inet6_sk(sk)->srcprefs : 0,
1032 &fl6->saddr);
1033 rcu_read_unlock();
1034
1035 if (err)
1036 goto out_err_release;
1037
1038 /* If we had an erroneous initial result, pretend it
1039 * never existed and let the SA-enabled version take
1040 * over.
1041 */
1042 if (!had_dst && (*dst)->error) {
1043 dst_release(*dst);
1044 *dst = NULL;
1045 }
1046
1047 if (fl6->flowi6_oif)
1048 flags |= RT6_LOOKUP_F_IFACE;
1049 }
1050
1051 if (!*dst)
1052 *dst = ip6_route_output_flags(net, sk, fl6, flags);
1053
1054 err = (*dst)->error;
1055 if (err)
1056 goto out_err_release;
1057
1058 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
1059 /*
1060 * Here if the dst entry we've looked up
1061 * has a neighbour entry that is in the INCOMPLETE
1062 * state and the src address from the flow is
1063 * marked as OPTIMISTIC, we release the found
1064 * dst entry and replace it instead with the
1065 * dst entry of the nexthop router
1066 */
1067 rt = (struct rt6_info *) *dst;
1068 rcu_read_lock_bh();
1069 n = __ipv6_neigh_lookup_noref(rt->dst.dev,
1070 rt6_nexthop(rt, &fl6->daddr));
1071 err = n && !(n->nud_state & NUD_VALID) ? -EINVAL : 0;
1072 rcu_read_unlock_bh();
1073
1074 if (err) {
1075 struct inet6_ifaddr *ifp;
1076 struct flowi6 fl_gw6;
1077 int redirect;
1078
1079 ifp = ipv6_get_ifaddr(net, &fl6->saddr,
1080 (*dst)->dev, 1);
1081
1082 redirect = (ifp && ifp->flags & IFA_F_OPTIMISTIC);
1083 if (ifp)
1084 in6_ifa_put(ifp);
1085
1086 if (redirect) {
1087 /*
1088 * We need to get the dst entry for the
1089 * default router instead
1090 */
1091 dst_release(*dst);
1092 memcpy(&fl_gw6, fl6, sizeof(struct flowi6));
1093 memset(&fl_gw6.daddr, 0, sizeof(struct in6_addr));
1094 *dst = ip6_route_output(net, sk, &fl_gw6);
1095 err = (*dst)->error;
1096 if (err)
1097 goto out_err_release;
1098 }
1099 }
1100 #endif
1101 if (ipv6_addr_v4mapped(&fl6->saddr) &&
1102 !(ipv6_addr_v4mapped(&fl6->daddr) || ipv6_addr_any(&fl6->daddr))) {
1103 err = -EAFNOSUPPORT;
1104 goto out_err_release;
1105 }
1106
1107 return 0;
1108
1109 out_err_release:
1110 dst_release(*dst);
1111 *dst = NULL;
1112
1113 if (err == -ENETUNREACH)
1114 IP6_INC_STATS(net, NULL, IPSTATS_MIB_OUTNOROUTES);
1115 return err;
1116 }
1117
1118 /**
1119 * ip6_dst_lookup - perform route lookup on flow
1120 * @sk: socket which provides route info
1121 * @dst: pointer to dst_entry * for result
1122 * @fl6: flow to lookup
1123 *
1124 * This function performs a route lookup on the given flow.
1125 *
1126 * It returns zero on success, or a standard errno code on error.
1127 */
ip6_dst_lookup(struct net * net,struct sock * sk,struct dst_entry ** dst,struct flowi6 * fl6)1128 int ip6_dst_lookup(struct net *net, struct sock *sk, struct dst_entry **dst,
1129 struct flowi6 *fl6)
1130 {
1131 *dst = NULL;
1132 return ip6_dst_lookup_tail(net, sk, dst, fl6);
1133 }
1134 EXPORT_SYMBOL_GPL(ip6_dst_lookup);
1135
1136 /**
1137 * ip6_dst_lookup_flow - perform route lookup on flow with ipsec
1138 * @sk: socket which provides route info
1139 * @fl6: flow to lookup
1140 * @final_dst: final destination address for ipsec lookup
1141 *
1142 * This function performs a route lookup on the given flow.
1143 *
1144 * It returns a valid dst pointer on success, or a pointer encoded
1145 * error code.
1146 */
ip6_dst_lookup_flow(const struct sock * sk,struct flowi6 * fl6,const struct in6_addr * final_dst)1147 struct dst_entry *ip6_dst_lookup_flow(const struct sock *sk, struct flowi6 *fl6,
1148 const struct in6_addr *final_dst)
1149 {
1150 struct dst_entry *dst = NULL;
1151 int err;
1152
1153 err = ip6_dst_lookup_tail(sock_net(sk), sk, &dst, fl6);
1154 if (err)
1155 return ERR_PTR(err);
1156 if (final_dst)
1157 fl6->daddr = *final_dst;
1158
1159 return xfrm_lookup_route(sock_net(sk), dst, flowi6_to_flowi(fl6), sk, 0);
1160 }
1161 EXPORT_SYMBOL_GPL(ip6_dst_lookup_flow);
1162
1163 /**
1164 * ip6_sk_dst_lookup_flow - perform socket cached route lookup on flow
1165 * @sk: socket which provides the dst cache and route info
1166 * @fl6: flow to lookup
1167 * @final_dst: final destination address for ipsec lookup
1168 * @connected: whether @sk is connected or not
1169 *
1170 * This function performs a route lookup on the given flow with the
1171 * possibility of using the cached route in the socket if it is valid.
1172 * It will take the socket dst lock when operating on the dst cache.
1173 * As a result, this function can only be used in process context.
1174 *
1175 * In addition, for a connected socket, cache the dst in the socket
1176 * if the current cache is not valid.
1177 *
1178 * It returns a valid dst pointer on success, or a pointer encoded
1179 * error code.
1180 */
ip6_sk_dst_lookup_flow(struct sock * sk,struct flowi6 * fl6,const struct in6_addr * final_dst,bool connected)1181 struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
1182 const struct in6_addr *final_dst,
1183 bool connected)
1184 {
1185 struct dst_entry *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie);
1186
1187 dst = ip6_sk_dst_check(sk, dst, fl6);
1188 if (dst)
1189 return dst;
1190
1191 dst = ip6_dst_lookup_flow(sk, fl6, final_dst);
1192 if (connected && !IS_ERR(dst))
1193 ip6_sk_dst_store_flow(sk, dst_clone(dst), fl6);
1194
1195 return dst;
1196 }
1197 EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup_flow);
1198
ip6_opt_dup(struct ipv6_opt_hdr * src,gfp_t gfp)1199 static inline struct ipv6_opt_hdr *ip6_opt_dup(struct ipv6_opt_hdr *src,
1200 gfp_t gfp)
1201 {
1202 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL;
1203 }
1204
ip6_rthdr_dup(struct ipv6_rt_hdr * src,gfp_t gfp)1205 static inline struct ipv6_rt_hdr *ip6_rthdr_dup(struct ipv6_rt_hdr *src,
1206 gfp_t gfp)
1207 {
1208 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL;
1209 }
1210
ip6_append_data_mtu(unsigned int * mtu,int * maxfraglen,unsigned int fragheaderlen,struct sk_buff * skb,struct rt6_info * rt,unsigned int orig_mtu)1211 static void ip6_append_data_mtu(unsigned int *mtu,
1212 int *maxfraglen,
1213 unsigned int fragheaderlen,
1214 struct sk_buff *skb,
1215 struct rt6_info *rt,
1216 unsigned int orig_mtu)
1217 {
1218 if (!(rt->dst.flags & DST_XFRM_TUNNEL)) {
1219 if (!skb) {
1220 /* first fragment, reserve header_len */
1221 *mtu = orig_mtu - rt->dst.header_len;
1222
1223 } else {
1224 /*
1225 * this fragment is not first, the headers
1226 * space is regarded as data space.
1227 */
1228 *mtu = orig_mtu;
1229 }
1230 *maxfraglen = ((*mtu - fragheaderlen) & ~7)
1231 + fragheaderlen - sizeof(struct frag_hdr);
1232 }
1233 }
1234
ip6_setup_cork(struct sock * sk,struct inet_cork_full * cork,struct inet6_cork * v6_cork,struct ipcm6_cookie * ipc6,struct rt6_info * rt,struct flowi6 * fl6)1235 static int ip6_setup_cork(struct sock *sk, struct inet_cork_full *cork,
1236 struct inet6_cork *v6_cork, struct ipcm6_cookie *ipc6,
1237 struct rt6_info *rt, struct flowi6 *fl6)
1238 {
1239 struct ipv6_pinfo *np = inet6_sk(sk);
1240 unsigned int mtu;
1241 struct ipv6_txoptions *opt = ipc6->opt;
1242
1243 /*
1244 * setup for corking
1245 */
1246 if (opt) {
1247 if (WARN_ON(v6_cork->opt))
1248 return -EINVAL;
1249
1250 v6_cork->opt = kzalloc(sizeof(*opt), sk->sk_allocation);
1251 if (unlikely(!v6_cork->opt))
1252 return -ENOBUFS;
1253
1254 v6_cork->opt->tot_len = sizeof(*opt);
1255 v6_cork->opt->opt_flen = opt->opt_flen;
1256 v6_cork->opt->opt_nflen = opt->opt_nflen;
1257
1258 v6_cork->opt->dst0opt = ip6_opt_dup(opt->dst0opt,
1259 sk->sk_allocation);
1260 if (opt->dst0opt && !v6_cork->opt->dst0opt)
1261 return -ENOBUFS;
1262
1263 v6_cork->opt->dst1opt = ip6_opt_dup(opt->dst1opt,
1264 sk->sk_allocation);
1265 if (opt->dst1opt && !v6_cork->opt->dst1opt)
1266 return -ENOBUFS;
1267
1268 v6_cork->opt->hopopt = ip6_opt_dup(opt->hopopt,
1269 sk->sk_allocation);
1270 if (opt->hopopt && !v6_cork->opt->hopopt)
1271 return -ENOBUFS;
1272
1273 v6_cork->opt->srcrt = ip6_rthdr_dup(opt->srcrt,
1274 sk->sk_allocation);
1275 if (opt->srcrt && !v6_cork->opt->srcrt)
1276 return -ENOBUFS;
1277
1278 /* need source address above miyazawa*/
1279 }
1280 dst_hold(&rt->dst);
1281 cork->base.dst = &rt->dst;
1282 cork->fl.u.ip6 = *fl6;
1283 v6_cork->hop_limit = ipc6->hlimit;
1284 v6_cork->tclass = ipc6->tclass;
1285 if (rt->dst.flags & DST_XFRM_TUNNEL)
1286 mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ?
1287 READ_ONCE(rt->dst.dev->mtu) : dst_mtu(&rt->dst);
1288 else
1289 mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ?
1290 READ_ONCE(rt->dst.dev->mtu) : dst_mtu(xfrm_dst_path(&rt->dst));
1291 if (np->frag_size < mtu) {
1292 if (np->frag_size)
1293 mtu = np->frag_size;
1294 }
1295 if (mtu < IPV6_MIN_MTU)
1296 return -EINVAL;
1297 cork->base.fragsize = mtu;
1298 cork->base.gso_size = ipc6->gso_size;
1299 cork->base.tx_flags = 0;
1300 cork->base.mark = ipc6->sockc.mark;
1301 sock_tx_timestamp(sk, ipc6->sockc.tsflags, &cork->base.tx_flags);
1302
1303 if (dst_allfrag(xfrm_dst_path(&rt->dst)))
1304 cork->base.flags |= IPCORK_ALLFRAG;
1305 cork->base.length = 0;
1306
1307 cork->base.transmit_time = ipc6->sockc.transmit_time;
1308
1309 return 0;
1310 }
1311
__ip6_append_data(struct sock * sk,struct flowi6 * fl6,struct sk_buff_head * queue,struct inet_cork * cork,struct inet6_cork * v6_cork,struct page_frag * pfrag,int getfrag (void * from,char * to,int offset,int len,int odd,struct sk_buff * skb),void * from,int length,int transhdrlen,unsigned int flags,struct ipcm6_cookie * ipc6)1312 static int __ip6_append_data(struct sock *sk,
1313 struct flowi6 *fl6,
1314 struct sk_buff_head *queue,
1315 struct inet_cork *cork,
1316 struct inet6_cork *v6_cork,
1317 struct page_frag *pfrag,
1318 int getfrag(void *from, char *to, int offset,
1319 int len, int odd, struct sk_buff *skb),
1320 void *from, int length, int transhdrlen,
1321 unsigned int flags, struct ipcm6_cookie *ipc6)
1322 {
1323 struct sk_buff *skb, *skb_prev = NULL;
1324 unsigned int maxfraglen, fragheaderlen, mtu, orig_mtu, pmtu;
1325 struct ubuf_info *uarg = NULL;
1326 int exthdrlen = 0;
1327 int dst_exthdrlen = 0;
1328 int hh_len;
1329 int copy;
1330 int err;
1331 int offset = 0;
1332 u32 tskey = 0;
1333 struct rt6_info *rt = (struct rt6_info *)cork->dst;
1334 struct ipv6_txoptions *opt = v6_cork->opt;
1335 int csummode = CHECKSUM_NONE;
1336 unsigned int maxnonfragsize, headersize;
1337 unsigned int wmem_alloc_delta = 0;
1338 bool paged, extra_uref = false;
1339
1340 skb = skb_peek_tail(queue);
1341 if (!skb) {
1342 exthdrlen = opt ? opt->opt_flen : 0;
1343 dst_exthdrlen = rt->dst.header_len - rt->rt6i_nfheader_len;
1344 }
1345
1346 paged = !!cork->gso_size;
1347 mtu = cork->gso_size ? IP6_MAX_MTU : cork->fragsize;
1348 orig_mtu = mtu;
1349
1350 if (cork->tx_flags & SKBTX_ANY_SW_TSTAMP &&
1351 sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)
1352 tskey = sk->sk_tskey++;
1353
1354 hh_len = LL_RESERVED_SPACE(rt->dst.dev);
1355
1356 fragheaderlen = sizeof(struct ipv6hdr) + rt->rt6i_nfheader_len +
1357 (opt ? opt->opt_nflen : 0);
1358 maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen -
1359 sizeof(struct frag_hdr);
1360
1361 headersize = sizeof(struct ipv6hdr) +
1362 (opt ? opt->opt_flen + opt->opt_nflen : 0) +
1363 (dst_allfrag(&rt->dst) ?
1364 sizeof(struct frag_hdr) : 0) +
1365 rt->rt6i_nfheader_len;
1366
1367 /* as per RFC 7112 section 5, the entire IPv6 Header Chain must fit
1368 * the first fragment
1369 */
1370 if (headersize + transhdrlen > mtu)
1371 goto emsgsize;
1372
1373 if (cork->length + length > mtu - headersize && ipc6->dontfrag &&
1374 (sk->sk_protocol == IPPROTO_UDP ||
1375 sk->sk_protocol == IPPROTO_RAW)) {
1376 ipv6_local_rxpmtu(sk, fl6, mtu - headersize +
1377 sizeof(struct ipv6hdr));
1378 goto emsgsize;
1379 }
1380
1381 if (ip6_sk_ignore_df(sk))
1382 maxnonfragsize = sizeof(struct ipv6hdr) + IPV6_MAXPLEN;
1383 else
1384 maxnonfragsize = mtu;
1385
1386 if (cork->length + length > maxnonfragsize - headersize) {
1387 emsgsize:
1388 pmtu = max_t(int, mtu - headersize + sizeof(struct ipv6hdr), 0);
1389 ipv6_local_error(sk, EMSGSIZE, fl6, pmtu);
1390 return -EMSGSIZE;
1391 }
1392
1393 /* CHECKSUM_PARTIAL only with no extension headers and when
1394 * we are not going to fragment
1395 */
1396 if (transhdrlen && sk->sk_protocol == IPPROTO_UDP &&
1397 headersize == sizeof(struct ipv6hdr) &&
1398 length <= mtu - headersize &&
1399 (!(flags & MSG_MORE) || cork->gso_size) &&
1400 rt->dst.dev->features & (NETIF_F_IPV6_CSUM | NETIF_F_HW_CSUM))
1401 csummode = CHECKSUM_PARTIAL;
1402
1403 if (flags & MSG_ZEROCOPY && length && sock_flag(sk, SOCK_ZEROCOPY)) {
1404 uarg = sock_zerocopy_realloc(sk, length, skb_zcopy(skb));
1405 if (!uarg)
1406 return -ENOBUFS;
1407 extra_uref = !skb_zcopy(skb); /* only ref on new uarg */
1408 if (rt->dst.dev->features & NETIF_F_SG &&
1409 csummode == CHECKSUM_PARTIAL) {
1410 paged = true;
1411 } else {
1412 uarg->zerocopy = 0;
1413 skb_zcopy_set(skb, uarg, &extra_uref);
1414 }
1415 }
1416
1417 /*
1418 * Let's try using as much space as possible.
1419 * Use MTU if total length of the message fits into the MTU.
1420 * Otherwise, we need to reserve fragment header and
1421 * fragment alignment (= 8-15 octects, in total).
1422 *
1423 * Note that we may need to "move" the data from the tail of
1424 * of the buffer to the new fragment when we split
1425 * the message.
1426 *
1427 * FIXME: It may be fragmented into multiple chunks
1428 * at once if non-fragmentable extension headers
1429 * are too large.
1430 * --yoshfuji
1431 */
1432
1433 cork->length += length;
1434 if (!skb)
1435 goto alloc_new_skb;
1436
1437 while (length > 0) {
1438 /* Check if the remaining data fits into current packet. */
1439 copy = (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len;
1440 if (copy < length)
1441 copy = maxfraglen - skb->len;
1442
1443 if (copy <= 0) {
1444 char *data;
1445 unsigned int datalen;
1446 unsigned int fraglen;
1447 unsigned int fraggap;
1448 unsigned int alloclen;
1449 unsigned int pagedlen;
1450 alloc_new_skb:
1451 /* There's no room in the current skb */
1452 if (skb)
1453 fraggap = skb->len - maxfraglen;
1454 else
1455 fraggap = 0;
1456 /* update mtu and maxfraglen if necessary */
1457 if (!skb || !skb_prev)
1458 ip6_append_data_mtu(&mtu, &maxfraglen,
1459 fragheaderlen, skb, rt,
1460 orig_mtu);
1461
1462 skb_prev = skb;
1463
1464 /*
1465 * If remaining data exceeds the mtu,
1466 * we know we need more fragment(s).
1467 */
1468 datalen = length + fraggap;
1469
1470 if (datalen > (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen)
1471 datalen = maxfraglen - fragheaderlen - rt->dst.trailer_len;
1472 fraglen = datalen + fragheaderlen;
1473 pagedlen = 0;
1474
1475 if ((flags & MSG_MORE) &&
1476 !(rt->dst.dev->features&NETIF_F_SG))
1477 alloclen = mtu;
1478 else if (!paged)
1479 alloclen = fraglen;
1480 else {
1481 alloclen = min_t(int, fraglen, MAX_HEADER);
1482 pagedlen = fraglen - alloclen;
1483 }
1484
1485 alloclen += dst_exthdrlen;
1486
1487 if (datalen != length + fraggap) {
1488 /*
1489 * this is not the last fragment, the trailer
1490 * space is regarded as data space.
1491 */
1492 datalen += rt->dst.trailer_len;
1493 }
1494
1495 alloclen += rt->dst.trailer_len;
1496 fraglen = datalen + fragheaderlen;
1497
1498 /*
1499 * We just reserve space for fragment header.
1500 * Note: this may be overallocation if the message
1501 * (without MSG_MORE) fits into the MTU.
1502 */
1503 alloclen += sizeof(struct frag_hdr);
1504
1505 copy = datalen - transhdrlen - fraggap - pagedlen;
1506 if (copy < 0) {
1507 err = -EINVAL;
1508 goto error;
1509 }
1510 if (transhdrlen) {
1511 skb = sock_alloc_send_skb(sk,
1512 alloclen + hh_len,
1513 (flags & MSG_DONTWAIT), &err);
1514 } else {
1515 skb = NULL;
1516 if (refcount_read(&sk->sk_wmem_alloc) + wmem_alloc_delta <=
1517 2 * sk->sk_sndbuf)
1518 skb = alloc_skb(alloclen + hh_len,
1519 sk->sk_allocation);
1520 if (unlikely(!skb))
1521 err = -ENOBUFS;
1522 }
1523 if (!skb)
1524 goto error;
1525 /*
1526 * Fill in the control structures
1527 */
1528 skb->protocol = htons(ETH_P_IPV6);
1529 skb->ip_summed = csummode;
1530 skb->csum = 0;
1531 /* reserve for fragmentation and ipsec header */
1532 skb_reserve(skb, hh_len + sizeof(struct frag_hdr) +
1533 dst_exthdrlen);
1534
1535 /*
1536 * Find where to start putting bytes
1537 */
1538 data = skb_put(skb, fraglen - pagedlen);
1539 skb_set_network_header(skb, exthdrlen);
1540 data += fragheaderlen;
1541 skb->transport_header = (skb->network_header +
1542 fragheaderlen);
1543 if (fraggap) {
1544 skb->csum = skb_copy_and_csum_bits(
1545 skb_prev, maxfraglen,
1546 data + transhdrlen, fraggap, 0);
1547 skb_prev->csum = csum_sub(skb_prev->csum,
1548 skb->csum);
1549 data += fraggap;
1550 pskb_trim_unique(skb_prev, maxfraglen);
1551 }
1552 if (copy > 0 &&
1553 getfrag(from, data + transhdrlen, offset,
1554 copy, fraggap, skb) < 0) {
1555 err = -EFAULT;
1556 kfree_skb(skb);
1557 goto error;
1558 }
1559
1560 offset += copy;
1561 length -= copy + transhdrlen;
1562 transhdrlen = 0;
1563 exthdrlen = 0;
1564 dst_exthdrlen = 0;
1565
1566 /* Only the initial fragment is time stamped */
1567 skb_shinfo(skb)->tx_flags = cork->tx_flags;
1568 cork->tx_flags = 0;
1569 skb_shinfo(skb)->tskey = tskey;
1570 tskey = 0;
1571 skb_zcopy_set(skb, uarg, &extra_uref);
1572
1573 if ((flags & MSG_CONFIRM) && !skb_prev)
1574 skb_set_dst_pending_confirm(skb, 1);
1575
1576 /*
1577 * Put the packet on the pending queue
1578 */
1579 if (!skb->destructor) {
1580 skb->destructor = sock_wfree;
1581 skb->sk = sk;
1582 wmem_alloc_delta += skb->truesize;
1583 }
1584 __skb_queue_tail(queue, skb);
1585 continue;
1586 }
1587
1588 if (copy > length)
1589 copy = length;
1590
1591 if (!(rt->dst.dev->features&NETIF_F_SG) &&
1592 skb_tailroom(skb) >= copy) {
1593 unsigned int off;
1594
1595 off = skb->len;
1596 if (getfrag(from, skb_put(skb, copy),
1597 offset, copy, off, skb) < 0) {
1598 __skb_trim(skb, off);
1599 err = -EFAULT;
1600 goto error;
1601 }
1602 } else if (!uarg || !uarg->zerocopy) {
1603 int i = skb_shinfo(skb)->nr_frags;
1604
1605 err = -ENOMEM;
1606 if (!sk_page_frag_refill(sk, pfrag))
1607 goto error;
1608
1609 if (!skb_can_coalesce(skb, i, pfrag->page,
1610 pfrag->offset)) {
1611 err = -EMSGSIZE;
1612 if (i == MAX_SKB_FRAGS)
1613 goto error;
1614
1615 __skb_fill_page_desc(skb, i, pfrag->page,
1616 pfrag->offset, 0);
1617 skb_shinfo(skb)->nr_frags = ++i;
1618 get_page(pfrag->page);
1619 }
1620 copy = min_t(int, copy, pfrag->size - pfrag->offset);
1621 if (getfrag(from,
1622 page_address(pfrag->page) + pfrag->offset,
1623 offset, copy, skb->len, skb) < 0)
1624 goto error_efault;
1625
1626 pfrag->offset += copy;
1627 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
1628 skb->len += copy;
1629 skb->data_len += copy;
1630 skb->truesize += copy;
1631 wmem_alloc_delta += copy;
1632 } else {
1633 err = skb_zerocopy_iter_dgram(skb, from, copy);
1634 if (err < 0)
1635 goto error;
1636 }
1637 offset += copy;
1638 length -= copy;
1639 }
1640
1641 if (wmem_alloc_delta)
1642 refcount_add(wmem_alloc_delta, &sk->sk_wmem_alloc);
1643 return 0;
1644
1645 error_efault:
1646 err = -EFAULT;
1647 error:
1648 if (uarg)
1649 sock_zerocopy_put_abort(uarg, extra_uref);
1650 cork->length -= length;
1651 IP6_INC_STATS(sock_net(sk), rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS);
1652 refcount_add(wmem_alloc_delta, &sk->sk_wmem_alloc);
1653 return err;
1654 }
1655
ip6_append_data(struct sock * sk,int getfrag (void * from,char * to,int offset,int len,int odd,struct sk_buff * skb),void * from,int length,int transhdrlen,struct ipcm6_cookie * ipc6,struct flowi6 * fl6,struct rt6_info * rt,unsigned int flags)1656 int ip6_append_data(struct sock *sk,
1657 int getfrag(void *from, char *to, int offset, int len,
1658 int odd, struct sk_buff *skb),
1659 void *from, int length, int transhdrlen,
1660 struct ipcm6_cookie *ipc6, struct flowi6 *fl6,
1661 struct rt6_info *rt, unsigned int flags)
1662 {
1663 struct inet_sock *inet = inet_sk(sk);
1664 struct ipv6_pinfo *np = inet6_sk(sk);
1665 int exthdrlen;
1666 int err;
1667
1668 if (flags&MSG_PROBE)
1669 return 0;
1670 if (skb_queue_empty(&sk->sk_write_queue)) {
1671 /*
1672 * setup for corking
1673 */
1674 err = ip6_setup_cork(sk, &inet->cork, &np->cork,
1675 ipc6, rt, fl6);
1676 if (err)
1677 return err;
1678
1679 exthdrlen = (ipc6->opt ? ipc6->opt->opt_flen : 0);
1680 length += exthdrlen;
1681 transhdrlen += exthdrlen;
1682 } else {
1683 fl6 = &inet->cork.fl.u.ip6;
1684 transhdrlen = 0;
1685 }
1686
1687 return __ip6_append_data(sk, fl6, &sk->sk_write_queue, &inet->cork.base,
1688 &np->cork, sk_page_frag(sk), getfrag,
1689 from, length, transhdrlen, flags, ipc6);
1690 }
1691 EXPORT_SYMBOL_GPL(ip6_append_data);
1692
ip6_cork_release(struct inet_cork_full * cork,struct inet6_cork * v6_cork)1693 static void ip6_cork_release(struct inet_cork_full *cork,
1694 struct inet6_cork *v6_cork)
1695 {
1696 if (v6_cork->opt) {
1697 kfree(v6_cork->opt->dst0opt);
1698 kfree(v6_cork->opt->dst1opt);
1699 kfree(v6_cork->opt->hopopt);
1700 kfree(v6_cork->opt->srcrt);
1701 kfree(v6_cork->opt);
1702 v6_cork->opt = NULL;
1703 }
1704
1705 if (cork->base.dst) {
1706 dst_release(cork->base.dst);
1707 cork->base.dst = NULL;
1708 cork->base.flags &= ~IPCORK_ALLFRAG;
1709 }
1710 memset(&cork->fl, 0, sizeof(cork->fl));
1711 }
1712
__ip6_make_skb(struct sock * sk,struct sk_buff_head * queue,struct inet_cork_full * cork,struct inet6_cork * v6_cork)1713 struct sk_buff *__ip6_make_skb(struct sock *sk,
1714 struct sk_buff_head *queue,
1715 struct inet_cork_full *cork,
1716 struct inet6_cork *v6_cork)
1717 {
1718 struct sk_buff *skb, *tmp_skb;
1719 struct sk_buff **tail_skb;
1720 struct in6_addr final_dst_buf, *final_dst = &final_dst_buf;
1721 struct ipv6_pinfo *np = inet6_sk(sk);
1722 struct net *net = sock_net(sk);
1723 struct ipv6hdr *hdr;
1724 struct ipv6_txoptions *opt = v6_cork->opt;
1725 struct rt6_info *rt = (struct rt6_info *)cork->base.dst;
1726 struct flowi6 *fl6 = &cork->fl.u.ip6;
1727 unsigned char proto = fl6->flowi6_proto;
1728
1729 skb = __skb_dequeue(queue);
1730 if (!skb)
1731 goto out;
1732 tail_skb = &(skb_shinfo(skb)->frag_list);
1733
1734 /* move skb->data to ip header from ext header */
1735 if (skb->data < skb_network_header(skb))
1736 __skb_pull(skb, skb_network_offset(skb));
1737 while ((tmp_skb = __skb_dequeue(queue)) != NULL) {
1738 __skb_pull(tmp_skb, skb_network_header_len(skb));
1739 *tail_skb = tmp_skb;
1740 tail_skb = &(tmp_skb->next);
1741 skb->len += tmp_skb->len;
1742 skb->data_len += tmp_skb->len;
1743 skb->truesize += tmp_skb->truesize;
1744 tmp_skb->destructor = NULL;
1745 tmp_skb->sk = NULL;
1746 }
1747
1748 /* Allow local fragmentation. */
1749 skb->ignore_df = ip6_sk_ignore_df(sk);
1750
1751 *final_dst = fl6->daddr;
1752 __skb_pull(skb, skb_network_header_len(skb));
1753 if (opt && opt->opt_flen)
1754 ipv6_push_frag_opts(skb, opt, &proto);
1755 if (opt && opt->opt_nflen)
1756 ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst, &fl6->saddr);
1757
1758 skb_push(skb, sizeof(struct ipv6hdr));
1759 skb_reset_network_header(skb);
1760 hdr = ipv6_hdr(skb);
1761
1762 ip6_flow_hdr(hdr, v6_cork->tclass,
1763 ip6_make_flowlabel(net, skb, fl6->flowlabel,
1764 ip6_autoflowlabel(net, np), fl6));
1765 hdr->hop_limit = v6_cork->hop_limit;
1766 hdr->nexthdr = proto;
1767 hdr->saddr = fl6->saddr;
1768 hdr->daddr = *final_dst;
1769
1770 skb->priority = sk->sk_priority;
1771 skb->mark = cork->base.mark;
1772
1773 skb->tstamp = cork->base.transmit_time;
1774
1775 skb_dst_set(skb, dst_clone(&rt->dst));
1776 IP6_UPD_PO_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUT, skb->len);
1777 if (proto == IPPROTO_ICMPV6) {
1778 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
1779
1780 ICMP6MSGOUT_INC_STATS(net, idev, icmp6_hdr(skb)->icmp6_type);
1781 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
1782 }
1783
1784 ip6_cork_release(cork, v6_cork);
1785 out:
1786 return skb;
1787 }
1788
ip6_send_skb(struct sk_buff * skb)1789 int ip6_send_skb(struct sk_buff *skb)
1790 {
1791 struct net *net = sock_net(skb->sk);
1792 struct rt6_info *rt = (struct rt6_info *)skb_dst(skb);
1793 int err;
1794
1795 err = ip6_local_out(net, skb->sk, skb);
1796 if (err) {
1797 if (err > 0)
1798 err = net_xmit_errno(err);
1799 if (err)
1800 IP6_INC_STATS(net, rt->rt6i_idev,
1801 IPSTATS_MIB_OUTDISCARDS);
1802 }
1803
1804 return err;
1805 }
1806
ip6_push_pending_frames(struct sock * sk)1807 int ip6_push_pending_frames(struct sock *sk)
1808 {
1809 struct sk_buff *skb;
1810
1811 skb = ip6_finish_skb(sk);
1812 if (!skb)
1813 return 0;
1814
1815 return ip6_send_skb(skb);
1816 }
1817 EXPORT_SYMBOL_GPL(ip6_push_pending_frames);
1818
__ip6_flush_pending_frames(struct sock * sk,struct sk_buff_head * queue,struct inet_cork_full * cork,struct inet6_cork * v6_cork)1819 static void __ip6_flush_pending_frames(struct sock *sk,
1820 struct sk_buff_head *queue,
1821 struct inet_cork_full *cork,
1822 struct inet6_cork *v6_cork)
1823 {
1824 struct sk_buff *skb;
1825
1826 while ((skb = __skb_dequeue_tail(queue)) != NULL) {
1827 if (skb_dst(skb))
1828 IP6_INC_STATS(sock_net(sk), ip6_dst_idev(skb_dst(skb)),
1829 IPSTATS_MIB_OUTDISCARDS);
1830 kfree_skb(skb);
1831 }
1832
1833 ip6_cork_release(cork, v6_cork);
1834 }
1835
ip6_flush_pending_frames(struct sock * sk)1836 void ip6_flush_pending_frames(struct sock *sk)
1837 {
1838 __ip6_flush_pending_frames(sk, &sk->sk_write_queue,
1839 &inet_sk(sk)->cork, &inet6_sk(sk)->cork);
1840 }
1841 EXPORT_SYMBOL_GPL(ip6_flush_pending_frames);
1842
ip6_make_skb(struct sock * sk,int getfrag (void * from,char * to,int offset,int len,int odd,struct sk_buff * skb),void * from,int length,int transhdrlen,struct ipcm6_cookie * ipc6,struct flowi6 * fl6,struct rt6_info * rt,unsigned int flags,struct inet_cork_full * cork)1843 struct sk_buff *ip6_make_skb(struct sock *sk,
1844 int getfrag(void *from, char *to, int offset,
1845 int len, int odd, struct sk_buff *skb),
1846 void *from, int length, int transhdrlen,
1847 struct ipcm6_cookie *ipc6, struct flowi6 *fl6,
1848 struct rt6_info *rt, unsigned int flags,
1849 struct inet_cork_full *cork)
1850 {
1851 struct inet6_cork v6_cork;
1852 struct sk_buff_head queue;
1853 int exthdrlen = (ipc6->opt ? ipc6->opt->opt_flen : 0);
1854 int err;
1855
1856 if (flags & MSG_PROBE)
1857 return NULL;
1858
1859 __skb_queue_head_init(&queue);
1860
1861 cork->base.flags = 0;
1862 cork->base.addr = 0;
1863 cork->base.opt = NULL;
1864 cork->base.dst = NULL;
1865 v6_cork.opt = NULL;
1866 err = ip6_setup_cork(sk, cork, &v6_cork, ipc6, rt, fl6);
1867 if (err) {
1868 ip6_cork_release(cork, &v6_cork);
1869 return ERR_PTR(err);
1870 }
1871 if (ipc6->dontfrag < 0)
1872 ipc6->dontfrag = inet6_sk(sk)->dontfrag;
1873
1874 err = __ip6_append_data(sk, fl6, &queue, &cork->base, &v6_cork,
1875 ¤t->task_frag, getfrag, from,
1876 length + exthdrlen, transhdrlen + exthdrlen,
1877 flags, ipc6);
1878 if (err) {
1879 __ip6_flush_pending_frames(sk, &queue, cork, &v6_cork);
1880 return ERR_PTR(err);
1881 }
1882
1883 return __ip6_make_skb(sk, &queue, cork, &v6_cork);
1884 }
1885
