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 #include <net/ip_tunnels.h>
58
ip6_finish_output2(struct net * net,struct sock * sk,struct sk_buff * skb)59 static int ip6_finish_output2(struct net *net, struct sock *sk, struct sk_buff *skb)
60 {
61 struct dst_entry *dst = skb_dst(skb);
62 struct net_device *dev = dst->dev;
63 struct inet6_dev *idev = ip6_dst_idev(dst);
64 unsigned int hh_len = LL_RESERVED_SPACE(dev);
65 const struct in6_addr *daddr, *nexthop;
66 struct ipv6hdr *hdr;
67 struct neighbour *neigh;
68 int ret;
69
70 /* Be paranoid, rather than too clever. */
71 if (unlikely(hh_len > skb_headroom(skb)) && dev->header_ops) {
72 skb = skb_expand_head(skb, hh_len);
73 if (!skb) {
74 IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTDISCARDS);
75 return -ENOMEM;
76 }
77 }
78
79 hdr = ipv6_hdr(skb);
80 daddr = &hdr->daddr;
81 if (ipv6_addr_is_multicast(daddr)) {
82 if (!(dev->flags & IFF_LOOPBACK) && sk_mc_loop(sk) &&
83 ((mroute6_is_socket(net, skb) &&
84 !(IP6CB(skb)->flags & IP6SKB_FORWARDED)) ||
85 ipv6_chk_mcast_addr(dev, daddr, &hdr->saddr))) {
86 struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC);
87
88 /* Do not check for IFF_ALLMULTI; multicast routing
89 is not supported in any case.
90 */
91 if (newskb)
92 NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING,
93 net, sk, newskb, NULL, newskb->dev,
94 dev_loopback_xmit);
95
96 if (hdr->hop_limit == 0) {
97 IP6_INC_STATS(net, idev,
98 IPSTATS_MIB_OUTDISCARDS);
99 kfree_skb(skb);
100 return 0;
101 }
102 }
103
104 IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUTMCAST, skb->len);
105 if (IPV6_ADDR_MC_SCOPE(daddr) <= IPV6_ADDR_SCOPE_NODELOCAL &&
106 !(dev->flags & IFF_LOOPBACK)) {
107 kfree_skb(skb);
108 return 0;
109 }
110 }
111
112 if (lwtunnel_xmit_redirect(dst->lwtstate)) {
113 int res = lwtunnel_xmit(skb);
114
115 if (res < 0 || res == LWTUNNEL_XMIT_DONE)
116 return res;
117 }
118
119 rcu_read_lock_bh();
120 nexthop = rt6_nexthop((struct rt6_info *)dst, daddr);
121 neigh = __ipv6_neigh_lookup_noref(dev, nexthop);
122 if (unlikely(!neigh))
123 neigh = __neigh_create(&nd_tbl, nexthop, dev, false);
124 if (!IS_ERR(neigh)) {
125 sock_confirm_neigh(skb, neigh);
126 ret = neigh_output(neigh, skb, false);
127 rcu_read_unlock_bh();
128 return ret;
129 }
130 rcu_read_unlock_bh();
131
132 IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTNOROUTES);
133 kfree_skb(skb);
134 return -EINVAL;
135 }
136
137 static int
ip6_finish_output_gso_slowpath_drop(struct net * net,struct sock * sk,struct sk_buff * skb,unsigned int mtu)138 ip6_finish_output_gso_slowpath_drop(struct net *net, struct sock *sk,
139 struct sk_buff *skb, unsigned int mtu)
140 {
141 struct sk_buff *segs, *nskb;
142 netdev_features_t features;
143 int ret = 0;
144
145 /* Please see corresponding comment in ip_finish_output_gso
146 * describing the cases where GSO segment length exceeds the
147 * egress MTU.
148 */
149 features = netif_skb_features(skb);
150 segs = skb_gso_segment(skb, features & ~NETIF_F_GSO_MASK);
151 if (IS_ERR_OR_NULL(segs)) {
152 kfree_skb(skb);
153 return -ENOMEM;
154 }
155
156 consume_skb(skb);
157
158 skb_list_walk_safe(segs, segs, nskb) {
159 int err;
160
161 skb_mark_not_on_list(segs);
162 err = ip6_fragment(net, sk, segs, ip6_finish_output2);
163 if (err && ret == 0)
164 ret = err;
165 }
166
167 return ret;
168 }
169
__ip6_finish_output(struct net * net,struct sock * sk,struct sk_buff * skb)170 static int __ip6_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb)
171 {
172 unsigned int mtu;
173
174 #if defined(CONFIG_NETFILTER) && defined(CONFIG_XFRM)
175 /* Policy lookup after SNAT yielded a new policy */
176 if (skb_dst(skb)->xfrm) {
177 IPCB(skb)->flags |= IPSKB_REROUTED;
178 return dst_output(net, sk, skb);
179 }
180 #endif
181
182 mtu = ip6_skb_dst_mtu(skb);
183 if (skb_is_gso(skb) && !skb_gso_validate_network_len(skb, mtu))
184 return ip6_finish_output_gso_slowpath_drop(net, sk, skb, mtu);
185
186 if ((skb->len > mtu && !skb_is_gso(skb)) ||
187 dst_allfrag(skb_dst(skb)) ||
188 (IP6CB(skb)->frag_max_size && skb->len > IP6CB(skb)->frag_max_size))
189 return ip6_fragment(net, sk, skb, ip6_finish_output2);
190 else
191 return ip6_finish_output2(net, sk, skb);
192 }
193
ip6_finish_output(struct net * net,struct sock * sk,struct sk_buff * skb)194 static int ip6_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb)
195 {
196 int ret;
197
198 ret = BPF_CGROUP_RUN_PROG_INET_EGRESS(sk, skb);
199 switch (ret) {
200 case NET_XMIT_SUCCESS:
201 return __ip6_finish_output(net, sk, skb);
202 case NET_XMIT_CN:
203 return __ip6_finish_output(net, sk, skb) ? : ret;
204 default:
205 kfree_skb(skb);
206 return ret;
207 }
208 }
209
ip6_output(struct net * net,struct sock * sk,struct sk_buff * skb)210 int ip6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
211 {
212 struct net_device *dev = skb_dst(skb)->dev, *indev = skb->dev;
213 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
214
215 skb->protocol = htons(ETH_P_IPV6);
216 skb->dev = dev;
217
218 if (unlikely(idev->cnf.disable_ipv6)) {
219 IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTDISCARDS);
220 kfree_skb(skb);
221 return 0;
222 }
223
224 return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING,
225 net, sk, skb, indev, dev,
226 ip6_finish_output,
227 !(IP6CB(skb)->flags & IP6SKB_REROUTED));
228 }
229 EXPORT_SYMBOL(ip6_output);
230
ip6_autoflowlabel(struct net * net,const struct ipv6_pinfo * np)231 bool ip6_autoflowlabel(struct net *net, const struct ipv6_pinfo *np)
232 {
233 if (!np->autoflowlabel_set)
234 return ip6_default_np_autolabel(net);
235 else
236 return np->autoflowlabel;
237 }
238
239 /*
240 * xmit an sk_buff (used by TCP, SCTP and DCCP)
241 * Note : socket lock is not held for SYNACK packets, but might be modified
242 * by calls to skb_set_owner_w() and ipv6_local_error(),
243 * which are using proper atomic operations or spinlocks.
244 */
ip6_xmit(const struct sock * sk,struct sk_buff * skb,struct flowi6 * fl6,__u32 mark,struct ipv6_txoptions * opt,int tclass,u32 priority)245 int ip6_xmit(const struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
246 __u32 mark, struct ipv6_txoptions *opt, int tclass, u32 priority)
247 {
248 struct net *net = sock_net(sk);
249 const struct ipv6_pinfo *np = inet6_sk(sk);
250 struct in6_addr *first_hop = &fl6->daddr;
251 struct dst_entry *dst = skb_dst(skb);
252 struct net_device *dev = dst->dev;
253 struct inet6_dev *idev = ip6_dst_idev(dst);
254 unsigned int head_room;
255 struct ipv6hdr *hdr;
256 u8 proto = fl6->flowi6_proto;
257 int seg_len = skb->len;
258 int hlimit = -1;
259 u32 mtu;
260
261 head_room = sizeof(struct ipv6hdr) + LL_RESERVED_SPACE(dev);
262 if (opt)
263 head_room += opt->opt_nflen + opt->opt_flen;
264
265 if (unlikely(head_room > skb_headroom(skb))) {
266 skb = skb_expand_head(skb, head_room);
267 if (!skb) {
268 IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTDISCARDS);
269 return -ENOBUFS;
270 }
271 }
272
273 if (opt) {
274 seg_len += opt->opt_nflen + opt->opt_flen;
275
276 if (opt->opt_flen)
277 ipv6_push_frag_opts(skb, opt, &proto);
278
279 if (opt->opt_nflen)
280 ipv6_push_nfrag_opts(skb, opt, &proto, &first_hop,
281 &fl6->saddr);
282 }
283
284 skb_push(skb, sizeof(struct ipv6hdr));
285 skb_reset_network_header(skb);
286 hdr = ipv6_hdr(skb);
287
288 /*
289 * Fill in the IPv6 header
290 */
291 if (np)
292 hlimit = np->hop_limit;
293 if (hlimit < 0)
294 hlimit = ip6_dst_hoplimit(dst);
295
296 ip6_flow_hdr(hdr, tclass, ip6_make_flowlabel(net, skb, fl6->flowlabel,
297 ip6_autoflowlabel(net, np), fl6));
298
299 hdr->payload_len = htons(seg_len);
300 hdr->nexthdr = proto;
301 hdr->hop_limit = hlimit;
302
303 hdr->saddr = fl6->saddr;
304 hdr->daddr = *first_hop;
305
306 skb->protocol = htons(ETH_P_IPV6);
307 skb->priority = priority;
308 skb->mark = mark;
309
310 mtu = dst_mtu(dst);
311 if ((skb->len <= mtu) || skb->ignore_df || skb_is_gso(skb)) {
312 IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
313
314 /* if egress device is enslaved to an L3 master device pass the
315 * skb to its handler for processing
316 */
317 skb = l3mdev_ip6_out((struct sock *)sk, skb);
318 if (unlikely(!skb))
319 return 0;
320
321 /* hooks should never assume socket lock is held.
322 * we promote our socket to non const
323 */
324 return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
325 net, (struct sock *)sk, skb, NULL, dev,
326 dst_output);
327 }
328
329 skb->dev = dev;
330 /* ipv6_local_error() does not require socket lock,
331 * we promote our socket to non const
332 */
333 ipv6_local_error((struct sock *)sk, EMSGSIZE, fl6, mtu);
334
335 IP6_INC_STATS(net, idev, IPSTATS_MIB_FRAGFAILS);
336 kfree_skb(skb);
337 return -EMSGSIZE;
338 }
339 EXPORT_SYMBOL(ip6_xmit);
340
ip6_call_ra_chain(struct sk_buff * skb,int sel)341 static int ip6_call_ra_chain(struct sk_buff *skb, int sel)
342 {
343 struct ip6_ra_chain *ra;
344 struct sock *last = NULL;
345
346 read_lock(&ip6_ra_lock);
347 for (ra = ip6_ra_chain; ra; ra = ra->next) {
348 struct sock *sk = ra->sk;
349 if (sk && ra->sel == sel &&
350 (!sk->sk_bound_dev_if ||
351 sk->sk_bound_dev_if == skb->dev->ifindex)) {
352 struct ipv6_pinfo *np = inet6_sk(sk);
353
354 if (np && np->rtalert_isolate &&
355 !net_eq(sock_net(sk), dev_net(skb->dev))) {
356 continue;
357 }
358 if (last) {
359 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
360 if (skb2)
361 rawv6_rcv(last, skb2);
362 }
363 last = sk;
364 }
365 }
366
367 if (last) {
368 rawv6_rcv(last, skb);
369 read_unlock(&ip6_ra_lock);
370 return 1;
371 }
372 read_unlock(&ip6_ra_lock);
373 return 0;
374 }
375
ip6_forward_proxy_check(struct sk_buff * skb)376 static int ip6_forward_proxy_check(struct sk_buff *skb)
377 {
378 struct ipv6hdr *hdr = ipv6_hdr(skb);
379 u8 nexthdr = hdr->nexthdr;
380 __be16 frag_off;
381 int offset;
382
383 if (ipv6_ext_hdr(nexthdr)) {
384 offset = ipv6_skip_exthdr(skb, sizeof(*hdr), &nexthdr, &frag_off);
385 if (offset < 0)
386 return 0;
387 } else
388 offset = sizeof(struct ipv6hdr);
389
390 if (nexthdr == IPPROTO_ICMPV6) {
391 struct icmp6hdr *icmp6;
392
393 if (!pskb_may_pull(skb, (skb_network_header(skb) +
394 offset + 1 - skb->data)))
395 return 0;
396
397 icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset);
398
399 switch (icmp6->icmp6_type) {
400 case NDISC_ROUTER_SOLICITATION:
401 case NDISC_ROUTER_ADVERTISEMENT:
402 case NDISC_NEIGHBOUR_SOLICITATION:
403 case NDISC_NEIGHBOUR_ADVERTISEMENT:
404 case NDISC_REDIRECT:
405 /* For reaction involving unicast neighbor discovery
406 * message destined to the proxied address, pass it to
407 * input function.
408 */
409 return 1;
410 default:
411 break;
412 }
413 }
414
415 /*
416 * The proxying router can't forward traffic sent to a link-local
417 * address, so signal the sender and discard the packet. This
418 * behavior is clarified by the MIPv6 specification.
419 */
420 if (ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) {
421 dst_link_failure(skb);
422 return -1;
423 }
424
425 return 0;
426 }
427
ip6_forward_finish(struct net * net,struct sock * sk,struct sk_buff * skb)428 static inline int ip6_forward_finish(struct net *net, struct sock *sk,
429 struct sk_buff *skb)
430 {
431 struct dst_entry *dst = skb_dst(skb);
432
433 __IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTFORWDATAGRAMS);
434 __IP6_ADD_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTOCTETS, skb->len);
435
436 #ifdef CONFIG_NET_SWITCHDEV
437 if (skb->offload_l3_fwd_mark) {
438 consume_skb(skb);
439 return 0;
440 }
441 #endif
442
443 skb->tstamp = 0;
444 return dst_output(net, sk, skb);
445 }
446
ip6_pkt_too_big(const struct sk_buff * skb,unsigned int mtu)447 static bool ip6_pkt_too_big(const struct sk_buff *skb, unsigned int mtu)
448 {
449 if (skb->len <= mtu)
450 return false;
451
452 /* ipv6 conntrack defrag sets max_frag_size + ignore_df */
453 if (IP6CB(skb)->frag_max_size && IP6CB(skb)->frag_max_size > mtu)
454 return true;
455
456 if (skb->ignore_df)
457 return false;
458
459 if (skb_is_gso(skb) && skb_gso_validate_network_len(skb, mtu))
460 return false;
461
462 return true;
463 }
464
ip6_forward(struct sk_buff * skb)465 int ip6_forward(struct sk_buff *skb)
466 {
467 struct dst_entry *dst = skb_dst(skb);
468 struct ipv6hdr *hdr = ipv6_hdr(skb);
469 struct inet6_skb_parm *opt = IP6CB(skb);
470 struct net *net = dev_net(dst->dev);
471 struct inet6_dev *idev;
472 u32 mtu;
473
474 idev = __in6_dev_get_safely(dev_get_by_index_rcu(net, IP6CB(skb)->iif));
475 if (net->ipv6.devconf_all->forwarding == 0)
476 goto error;
477
478 if (skb->pkt_type != PACKET_HOST)
479 goto drop;
480
481 if (unlikely(skb->sk))
482 goto drop;
483
484 if (skb_warn_if_lro(skb))
485 goto drop;
486
487 if (!net->ipv6.devconf_all->disable_policy &&
488 !idev->cnf.disable_policy &&
489 !xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) {
490 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS);
491 goto drop;
492 }
493
494 skb_forward_csum(skb);
495
496 /*
497 * We DO NOT make any processing on
498 * RA packets, pushing them to user level AS IS
499 * without ane WARRANTY that application will be able
500 * to interpret them. The reason is that we
501 * cannot make anything clever here.
502 *
503 * We are not end-node, so that if packet contains
504 * AH/ESP, we cannot make anything.
505 * Defragmentation also would be mistake, RA packets
506 * cannot be fragmented, because there is no warranty
507 * that different fragments will go along one path. --ANK
508 */
509 if (unlikely(opt->flags & IP6SKB_ROUTERALERT)) {
510 if (ip6_call_ra_chain(skb, ntohs(opt->ra)))
511 return 0;
512 }
513
514 /*
515 * check and decrement ttl
516 */
517 if (hdr->hop_limit <= 1) {
518 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 0);
519 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
520
521 kfree_skb(skb);
522 return -ETIMEDOUT;
523 }
524
525 /* XXX: idev->cnf.proxy_ndp? */
526 if (net->ipv6.devconf_all->proxy_ndp &&
527 pneigh_lookup(&nd_tbl, net, &hdr->daddr, skb->dev, 0)) {
528 int proxied = ip6_forward_proxy_check(skb);
529 if (proxied > 0) {
530 hdr->hop_limit--;
531 return ip6_input(skb);
532 } else if (proxied < 0) {
533 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS);
534 goto drop;
535 }
536 }
537
538 if (!xfrm6_route_forward(skb)) {
539 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS);
540 goto drop;
541 }
542 dst = skb_dst(skb);
543
544 /* IPv6 specs say nothing about it, but it is clear that we cannot
545 send redirects to source routed frames.
546 We don't send redirects to frames decapsulated from IPsec.
547 */
548 if (IP6CB(skb)->iif == dst->dev->ifindex &&
549 opt->srcrt == 0 && !skb_sec_path(skb)) {
550 struct in6_addr *target = NULL;
551 struct inet_peer *peer;
552 struct rt6_info *rt;
553
554 /*
555 * incoming and outgoing devices are the same
556 * send a redirect.
557 */
558
559 rt = (struct rt6_info *) dst;
560 if (rt->rt6i_flags & RTF_GATEWAY)
561 target = &rt->rt6i_gateway;
562 else
563 target = &hdr->daddr;
564
565 peer = inet_getpeer_v6(net->ipv6.peers, &hdr->daddr, 1);
566
567 /* Limit redirects both by destination (here)
568 and by source (inside ndisc_send_redirect)
569 */
570 if (inet_peer_xrlim_allow(peer, 1*HZ))
571 ndisc_send_redirect(skb, target);
572 if (peer)
573 inet_putpeer(peer);
574 } else {
575 int addrtype = ipv6_addr_type(&hdr->saddr);
576
577 /* This check is security critical. */
578 if (addrtype == IPV6_ADDR_ANY ||
579 addrtype & (IPV6_ADDR_MULTICAST | IPV6_ADDR_LOOPBACK))
580 goto error;
581 if (addrtype & IPV6_ADDR_LINKLOCAL) {
582 icmpv6_send(skb, ICMPV6_DEST_UNREACH,
583 ICMPV6_NOT_NEIGHBOUR, 0);
584 goto error;
585 }
586 }
587
588 mtu = ip6_dst_mtu_maybe_forward(dst, true);
589 if (mtu < IPV6_MIN_MTU)
590 mtu = IPV6_MIN_MTU;
591
592 if (ip6_pkt_too_big(skb, mtu)) {
593 /* Again, force OUTPUT device used as source address */
594 skb->dev = dst->dev;
595 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
596 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INTOOBIGERRORS);
597 __IP6_INC_STATS(net, ip6_dst_idev(dst),
598 IPSTATS_MIB_FRAGFAILS);
599 kfree_skb(skb);
600 return -EMSGSIZE;
601 }
602
603 if (skb_cow(skb, dst->dev->hard_header_len)) {
604 __IP6_INC_STATS(net, ip6_dst_idev(dst),
605 IPSTATS_MIB_OUTDISCARDS);
606 goto drop;
607 }
608
609 hdr = ipv6_hdr(skb);
610
611 /* Mangling hops number delayed to point after skb COW */
612
613 hdr->hop_limit--;
614
615 return NF_HOOK(NFPROTO_IPV6, NF_INET_FORWARD,
616 net, NULL, skb, skb->dev, dst->dev,
617 ip6_forward_finish);
618
619 error:
620 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
621 drop:
622 kfree_skb(skb);
623 return -EINVAL;
624 }
625
ip6_copy_metadata(struct sk_buff * to,struct sk_buff * from)626 static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from)
627 {
628 to->pkt_type = from->pkt_type;
629 to->priority = from->priority;
630 to->protocol = from->protocol;
631 skb_dst_drop(to);
632 skb_dst_set(to, dst_clone(skb_dst(from)));
633 to->dev = from->dev;
634 to->mark = from->mark;
635
636 skb_copy_hash(to, from);
637
638 #ifdef CONFIG_NET_SCHED
639 to->tc_index = from->tc_index;
640 #endif
641 nf_copy(to, from);
642 skb_ext_copy(to, from);
643 skb_copy_secmark(to, from);
644 }
645
ip6_fraglist_init(struct sk_buff * skb,unsigned int hlen,u8 * prevhdr,u8 nexthdr,__be32 frag_id,struct ip6_fraglist_iter * iter)646 int ip6_fraglist_init(struct sk_buff *skb, unsigned int hlen, u8 *prevhdr,
647 u8 nexthdr, __be32 frag_id,
648 struct ip6_fraglist_iter *iter)
649 {
650 unsigned int first_len;
651 struct frag_hdr *fh;
652
653 /* BUILD HEADER */
654 *prevhdr = NEXTHDR_FRAGMENT;
655 iter->tmp_hdr = kmemdup(skb_network_header(skb), hlen, GFP_ATOMIC);
656 if (!iter->tmp_hdr)
657 return -ENOMEM;
658
659 iter->frag = skb_shinfo(skb)->frag_list;
660 skb_frag_list_init(skb);
661
662 iter->offset = 0;
663 iter->hlen = hlen;
664 iter->frag_id = frag_id;
665 iter->nexthdr = nexthdr;
666
667 __skb_pull(skb, hlen);
668 fh = __skb_push(skb, sizeof(struct frag_hdr));
669 __skb_push(skb, hlen);
670 skb_reset_network_header(skb);
671 memcpy(skb_network_header(skb), iter->tmp_hdr, hlen);
672
673 fh->nexthdr = nexthdr;
674 fh->reserved = 0;
675 fh->frag_off = htons(IP6_MF);
676 fh->identification = frag_id;
677
678 first_len = skb_pagelen(skb);
679 skb->data_len = first_len - skb_headlen(skb);
680 skb->len = first_len;
681 ipv6_hdr(skb)->payload_len = htons(first_len - sizeof(struct ipv6hdr));
682
683 return 0;
684 }
685 EXPORT_SYMBOL(ip6_fraglist_init);
686
ip6_fraglist_prepare(struct sk_buff * skb,struct ip6_fraglist_iter * iter)687 void ip6_fraglist_prepare(struct sk_buff *skb,
688 struct ip6_fraglist_iter *iter)
689 {
690 struct sk_buff *frag = iter->frag;
691 unsigned int hlen = iter->hlen;
692 struct frag_hdr *fh;
693
694 frag->ip_summed = CHECKSUM_NONE;
695 skb_reset_transport_header(frag);
696 fh = __skb_push(frag, sizeof(struct frag_hdr));
697 __skb_push(frag, hlen);
698 skb_reset_network_header(frag);
699 memcpy(skb_network_header(frag), iter->tmp_hdr, hlen);
700 iter->offset += skb->len - hlen - sizeof(struct frag_hdr);
701 fh->nexthdr = iter->nexthdr;
702 fh->reserved = 0;
703 fh->frag_off = htons(iter->offset);
704 if (frag->next)
705 fh->frag_off |= htons(IP6_MF);
706 fh->identification = iter->frag_id;
707 ipv6_hdr(frag)->payload_len = htons(frag->len - sizeof(struct ipv6hdr));
708 ip6_copy_metadata(frag, skb);
709 }
710 EXPORT_SYMBOL(ip6_fraglist_prepare);
711
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)712 void ip6_frag_init(struct sk_buff *skb, unsigned int hlen, unsigned int mtu,
713 unsigned short needed_tailroom, int hdr_room, u8 *prevhdr,
714 u8 nexthdr, __be32 frag_id, struct ip6_frag_state *state)
715 {
716 state->prevhdr = prevhdr;
717 state->nexthdr = nexthdr;
718 state->frag_id = frag_id;
719
720 state->hlen = hlen;
721 state->mtu = mtu;
722
723 state->left = skb->len - hlen; /* Space per frame */
724 state->ptr = hlen; /* Where to start from */
725
726 state->hroom = hdr_room;
727 state->troom = needed_tailroom;
728
729 state->offset = 0;
730 }
731 EXPORT_SYMBOL(ip6_frag_init);
732
ip6_frag_next(struct sk_buff * skb,struct ip6_frag_state * state)733 struct sk_buff *ip6_frag_next(struct sk_buff *skb, struct ip6_frag_state *state)
734 {
735 u8 *prevhdr = state->prevhdr, *fragnexthdr_offset;
736 struct sk_buff *frag;
737 struct frag_hdr *fh;
738 unsigned int len;
739
740 len = state->left;
741 /* IF: it doesn't fit, use 'mtu' - the data space left */
742 if (len > state->mtu)
743 len = state->mtu;
744 /* IF: we are not sending up to and including the packet end
745 then align the next start on an eight byte boundary */
746 if (len < state->left)
747 len &= ~7;
748
749 /* Allocate buffer */
750 frag = alloc_skb(len + state->hlen + sizeof(struct frag_hdr) +
751 state->hroom + state->troom, GFP_ATOMIC);
752 if (!frag)
753 return ERR_PTR(-ENOMEM);
754
755 /*
756 * Set up data on packet
757 */
758
759 ip6_copy_metadata(frag, skb);
760 skb_reserve(frag, state->hroom);
761 skb_put(frag, len + state->hlen + sizeof(struct frag_hdr));
762 skb_reset_network_header(frag);
763 fh = (struct frag_hdr *)(skb_network_header(frag) + state->hlen);
764 frag->transport_header = (frag->network_header + state->hlen +
765 sizeof(struct frag_hdr));
766
767 /*
768 * Charge the memory for the fragment to any owner
769 * it might possess
770 */
771 if (skb->sk)
772 skb_set_owner_w(frag, skb->sk);
773
774 /*
775 * Copy the packet header into the new buffer.
776 */
777 skb_copy_from_linear_data(skb, skb_network_header(frag), state->hlen);
778
779 fragnexthdr_offset = skb_network_header(frag);
780 fragnexthdr_offset += prevhdr - skb_network_header(skb);
781 *fragnexthdr_offset = NEXTHDR_FRAGMENT;
782
783 /*
784 * Build fragment header.
785 */
786 fh->nexthdr = state->nexthdr;
787 fh->reserved = 0;
788 fh->identification = state->frag_id;
789
790 /*
791 * Copy a block of the IP datagram.
792 */
793 BUG_ON(skb_copy_bits(skb, state->ptr, skb_transport_header(frag),
794 len));
795 state->left -= len;
796
797 fh->frag_off = htons(state->offset);
798 if (state->left > 0)
799 fh->frag_off |= htons(IP6_MF);
800 ipv6_hdr(frag)->payload_len = htons(frag->len - sizeof(struct ipv6hdr));
801
802 state->ptr += len;
803 state->offset += len;
804
805 return frag;
806 }
807 EXPORT_SYMBOL(ip6_frag_next);
808
ip6_fragment(struct net * net,struct sock * sk,struct sk_buff * skb,int (* output)(struct net *,struct sock *,struct sk_buff *))809 int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
810 int (*output)(struct net *, struct sock *, struct sk_buff *))
811 {
812 struct sk_buff *frag;
813 struct rt6_info *rt = (struct rt6_info *)skb_dst(skb);
814 struct ipv6_pinfo *np = skb->sk && !dev_recursion_level() ?
815 inet6_sk(skb->sk) : NULL;
816 struct ip6_frag_state state;
817 unsigned int mtu, hlen, nexthdr_offset;
818 ktime_t tstamp = skb->tstamp;
819 int hroom, err = 0;
820 __be32 frag_id;
821 u8 *prevhdr, nexthdr = 0;
822
823 err = ip6_find_1stfragopt(skb, &prevhdr);
824 if (err < 0)
825 goto fail;
826 hlen = err;
827 nexthdr = *prevhdr;
828 nexthdr_offset = prevhdr - skb_network_header(skb);
829
830 mtu = ip6_skb_dst_mtu(skb);
831
832 /* We must not fragment if the socket is set to force MTU discovery
833 * or if the skb it not generated by a local socket.
834 */
835 if (unlikely(!skb->ignore_df && skb->len > mtu))
836 goto fail_toobig;
837
838 if (IP6CB(skb)->frag_max_size) {
839 if (IP6CB(skb)->frag_max_size > mtu)
840 goto fail_toobig;
841
842 /* don't send fragments larger than what we received */
843 mtu = IP6CB(skb)->frag_max_size;
844 if (mtu < IPV6_MIN_MTU)
845 mtu = IPV6_MIN_MTU;
846 }
847
848 if (np && np->frag_size < mtu) {
849 if (np->frag_size)
850 mtu = np->frag_size;
851 }
852 if (mtu < hlen + sizeof(struct frag_hdr) + 8)
853 goto fail_toobig;
854 mtu -= hlen + sizeof(struct frag_hdr);
855
856 frag_id = ipv6_select_ident(net, &ipv6_hdr(skb)->daddr,
857 &ipv6_hdr(skb)->saddr);
858
859 if (skb->ip_summed == CHECKSUM_PARTIAL &&
860 (err = skb_checksum_help(skb)))
861 goto fail;
862
863 prevhdr = skb_network_header(skb) + nexthdr_offset;
864 hroom = LL_RESERVED_SPACE(rt->dst.dev);
865 if (skb_has_frag_list(skb)) {
866 unsigned int first_len = skb_pagelen(skb);
867 struct ip6_fraglist_iter iter;
868 struct sk_buff *frag2;
869
870 if (first_len - hlen > mtu ||
871 ((first_len - hlen) & 7) ||
872 skb_cloned(skb) ||
873 skb_headroom(skb) < (hroom + sizeof(struct frag_hdr)))
874 goto slow_path;
875
876 skb_walk_frags(skb, frag) {
877 /* Correct geometry. */
878 if (frag->len > mtu ||
879 ((frag->len & 7) && frag->next) ||
880 skb_headroom(frag) < (hlen + hroom + sizeof(struct frag_hdr)))
881 goto slow_path_clean;
882
883 /* Partially cloned skb? */
884 if (skb_shared(frag))
885 goto slow_path_clean;
886
887 BUG_ON(frag->sk);
888 if (skb->sk) {
889 frag->sk = skb->sk;
890 frag->destructor = sock_wfree;
891 }
892 skb->truesize -= frag->truesize;
893 }
894
895 err = ip6_fraglist_init(skb, hlen, prevhdr, nexthdr, frag_id,
896 &iter);
897 if (err < 0)
898 goto fail;
899
900 for (;;) {
901 /* Prepare header of the next frame,
902 * before previous one went down. */
903 if (iter.frag)
904 ip6_fraglist_prepare(skb, &iter);
905
906 skb->tstamp = tstamp;
907 err = output(net, sk, skb);
908 if (!err)
909 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
910 IPSTATS_MIB_FRAGCREATES);
911
912 if (err || !iter.frag)
913 break;
914
915 skb = ip6_fraglist_next(&iter);
916 }
917
918 kfree(iter.tmp_hdr);
919
920 if (err == 0) {
921 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
922 IPSTATS_MIB_FRAGOKS);
923 return 0;
924 }
925
926 kfree_skb_list(iter.frag);
927
928 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
929 IPSTATS_MIB_FRAGFAILS);
930 return err;
931
932 slow_path_clean:
933 skb_walk_frags(skb, frag2) {
934 if (frag2 == frag)
935 break;
936 frag2->sk = NULL;
937 frag2->destructor = NULL;
938 skb->truesize += frag2->truesize;
939 }
940 }
941
942 slow_path:
943 /*
944 * Fragment the datagram.
945 */
946
947 ip6_frag_init(skb, hlen, mtu, rt->dst.dev->needed_tailroom,
948 LL_RESERVED_SPACE(rt->dst.dev), prevhdr, nexthdr, frag_id,
949 &state);
950
951 /*
952 * Keep copying data until we run out.
953 */
954
955 while (state.left > 0) {
956 frag = ip6_frag_next(skb, &state);
957 if (IS_ERR(frag)) {
958 err = PTR_ERR(frag);
959 goto fail;
960 }
961
962 /*
963 * Put this fragment into the sending queue.
964 */
965 frag->tstamp = tstamp;
966 err = output(net, sk, frag);
967 if (err)
968 goto fail;
969
970 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
971 IPSTATS_MIB_FRAGCREATES);
972 }
973 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
974 IPSTATS_MIB_FRAGOKS);
975 consume_skb(skb);
976 return err;
977
978 fail_toobig:
979 if (skb->sk && dst_allfrag(skb_dst(skb)))
980 sk_nocaps_add(skb->sk, NETIF_F_GSO_MASK);
981
982 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
983 err = -EMSGSIZE;
984
985 fail:
986 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
987 IPSTATS_MIB_FRAGFAILS);
988 kfree_skb(skb);
989 return err;
990 }
991
ip6_rt_check(const struct rt6key * rt_key,const struct in6_addr * fl_addr,const struct in6_addr * addr_cache)992 static inline int ip6_rt_check(const struct rt6key *rt_key,
993 const struct in6_addr *fl_addr,
994 const struct in6_addr *addr_cache)
995 {
996 return (rt_key->plen != 128 || !ipv6_addr_equal(fl_addr, &rt_key->addr)) &&
997 (!addr_cache || !ipv6_addr_equal(fl_addr, addr_cache));
998 }
999
ip6_sk_dst_check(struct sock * sk,struct dst_entry * dst,const struct flowi6 * fl6)1000 static struct dst_entry *ip6_sk_dst_check(struct sock *sk,
1001 struct dst_entry *dst,
1002 const struct flowi6 *fl6)
1003 {
1004 struct ipv6_pinfo *np = inet6_sk(sk);
1005 struct rt6_info *rt;
1006
1007 if (!dst)
1008 goto out;
1009
1010 if (dst->ops->family != AF_INET6) {
1011 dst_release(dst);
1012 return NULL;
1013 }
1014
1015 rt = (struct rt6_info *)dst;
1016 /* Yes, checking route validity in not connected
1017 * case is not very simple. Take into account,
1018 * that we do not support routing by source, TOS,
1019 * and MSG_DONTROUTE --ANK (980726)
1020 *
1021 * 1. ip6_rt_check(): If route was host route,
1022 * check that cached destination is current.
1023 * If it is network route, we still may
1024 * check its validity using saved pointer
1025 * to the last used address: daddr_cache.
1026 * We do not want to save whole address now,
1027 * (because main consumer of this service
1028 * is tcp, which has not this problem),
1029 * so that the last trick works only on connected
1030 * sockets.
1031 * 2. oif also should be the same.
1032 */
1033 if (ip6_rt_check(&rt->rt6i_dst, &fl6->daddr, np->daddr_cache) ||
1034 #ifdef CONFIG_IPV6_SUBTREES
1035 ip6_rt_check(&rt->rt6i_src, &fl6->saddr, np->saddr_cache) ||
1036 #endif
1037 (!(fl6->flowi6_flags & FLOWI_FLAG_SKIP_NH_OIF) &&
1038 (fl6->flowi6_oif && fl6->flowi6_oif != dst->dev->ifindex))) {
1039 dst_release(dst);
1040 dst = NULL;
1041 }
1042
1043 out:
1044 return dst;
1045 }
1046
ip6_dst_lookup_tail(struct net * net,const struct sock * sk,struct dst_entry ** dst,struct flowi6 * fl6)1047 static int ip6_dst_lookup_tail(struct net *net, const struct sock *sk,
1048 struct dst_entry **dst, struct flowi6 *fl6)
1049 {
1050 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
1051 struct neighbour *n;
1052 struct rt6_info *rt;
1053 #endif
1054 int err;
1055 int flags = 0;
1056
1057 /* The correct way to handle this would be to do
1058 * ip6_route_get_saddr, and then ip6_route_output; however,
1059 * the route-specific preferred source forces the
1060 * ip6_route_output call _before_ ip6_route_get_saddr.
1061 *
1062 * In source specific routing (no src=any default route),
1063 * ip6_route_output will fail given src=any saddr, though, so
1064 * that's why we try it again later.
1065 */
1066 if (ipv6_addr_any(&fl6->saddr)) {
1067 struct fib6_info *from;
1068 struct rt6_info *rt;
1069
1070 *dst = ip6_route_output(net, sk, fl6);
1071 rt = (*dst)->error ? NULL : (struct rt6_info *)*dst;
1072
1073 rcu_read_lock();
1074 from = rt ? rcu_dereference(rt->from) : NULL;
1075 err = ip6_route_get_saddr(net, from, &fl6->daddr,
1076 sk ? inet6_sk(sk)->srcprefs : 0,
1077 &fl6->saddr);
1078 rcu_read_unlock();
1079
1080 if (err)
1081 goto out_err_release;
1082
1083 /* If we had an erroneous initial result, pretend it
1084 * never existed and let the SA-enabled version take
1085 * over.
1086 */
1087 if ((*dst)->error) {
1088 dst_release(*dst);
1089 *dst = NULL;
1090 }
1091
1092 if (fl6->flowi6_oif)
1093 flags |= RT6_LOOKUP_F_IFACE;
1094 }
1095
1096 if (!*dst)
1097 *dst = ip6_route_output_flags(net, sk, fl6, flags);
1098
1099 err = (*dst)->error;
1100 if (err)
1101 goto out_err_release;
1102
1103 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
1104 /*
1105 * Here if the dst entry we've looked up
1106 * has a neighbour entry that is in the INCOMPLETE
1107 * state and the src address from the flow is
1108 * marked as OPTIMISTIC, we release the found
1109 * dst entry and replace it instead with the
1110 * dst entry of the nexthop router
1111 */
1112 rt = (struct rt6_info *) *dst;
1113 rcu_read_lock_bh();
1114 n = __ipv6_neigh_lookup_noref(rt->dst.dev,
1115 rt6_nexthop(rt, &fl6->daddr));
1116 err = n && !(n->nud_state & NUD_VALID) ? -EINVAL : 0;
1117 rcu_read_unlock_bh();
1118
1119 if (err) {
1120 struct inet6_ifaddr *ifp;
1121 struct flowi6 fl_gw6;
1122 int redirect;
1123
1124 ifp = ipv6_get_ifaddr(net, &fl6->saddr,
1125 (*dst)->dev, 1);
1126
1127 redirect = (ifp && ifp->flags & IFA_F_OPTIMISTIC);
1128 if (ifp)
1129 in6_ifa_put(ifp);
1130
1131 if (redirect) {
1132 /*
1133 * We need to get the dst entry for the
1134 * default router instead
1135 */
1136 dst_release(*dst);
1137 memcpy(&fl_gw6, fl6, sizeof(struct flowi6));
1138 memset(&fl_gw6.daddr, 0, sizeof(struct in6_addr));
1139 *dst = ip6_route_output(net, sk, &fl_gw6);
1140 err = (*dst)->error;
1141 if (err)
1142 goto out_err_release;
1143 }
1144 }
1145 #endif
1146 if (ipv6_addr_v4mapped(&fl6->saddr) &&
1147 !(ipv6_addr_v4mapped(&fl6->daddr) || ipv6_addr_any(&fl6->daddr))) {
1148 err = -EAFNOSUPPORT;
1149 goto out_err_release;
1150 }
1151
1152 return 0;
1153
1154 out_err_release:
1155 dst_release(*dst);
1156 *dst = NULL;
1157
1158 if (err == -ENETUNREACH)
1159 IP6_INC_STATS(net, NULL, IPSTATS_MIB_OUTNOROUTES);
1160 return err;
1161 }
1162
1163 /**
1164 * ip6_dst_lookup - perform route lookup on flow
1165 * @net: Network namespace to perform lookup in
1166 * @sk: socket which provides route info
1167 * @dst: pointer to dst_entry * for result
1168 * @fl6: flow to lookup
1169 *
1170 * This function performs a route lookup on the given flow.
1171 *
1172 * It returns zero on success, or a standard errno code on error.
1173 */
ip6_dst_lookup(struct net * net,struct sock * sk,struct dst_entry ** dst,struct flowi6 * fl6)1174 int ip6_dst_lookup(struct net *net, struct sock *sk, struct dst_entry **dst,
1175 struct flowi6 *fl6)
1176 {
1177 *dst = NULL;
1178 return ip6_dst_lookup_tail(net, sk, dst, fl6);
1179 }
1180 EXPORT_SYMBOL_GPL(ip6_dst_lookup);
1181
1182 /**
1183 * ip6_dst_lookup_flow - perform route lookup on flow with ipsec
1184 * @net: Network namespace to perform lookup in
1185 * @sk: socket which provides route info
1186 * @fl6: flow to lookup
1187 * @final_dst: final destination address for ipsec lookup
1188 *
1189 * This function performs a route lookup on the given flow.
1190 *
1191 * It returns a valid dst pointer on success, or a pointer encoded
1192 * error code.
1193 */
ip6_dst_lookup_flow(struct net * net,const struct sock * sk,struct flowi6 * fl6,const struct in6_addr * final_dst)1194 struct dst_entry *ip6_dst_lookup_flow(struct net *net, const struct sock *sk, struct flowi6 *fl6,
1195 const struct in6_addr *final_dst)
1196 {
1197 struct dst_entry *dst = NULL;
1198 int err;
1199
1200 err = ip6_dst_lookup_tail(net, sk, &dst, fl6);
1201 if (err)
1202 return ERR_PTR(err);
1203 if (final_dst)
1204 fl6->daddr = *final_dst;
1205
1206 return xfrm_lookup_route(net, dst, flowi6_to_flowi(fl6), sk, 0);
1207 }
1208 EXPORT_SYMBOL_GPL(ip6_dst_lookup_flow);
1209
1210 /**
1211 * ip6_sk_dst_lookup_flow - perform socket cached route lookup on flow
1212 * @sk: socket which provides the dst cache and route info
1213 * @fl6: flow to lookup
1214 * @final_dst: final destination address for ipsec lookup
1215 * @connected: whether @sk is connected or not
1216 *
1217 * This function performs a route lookup on the given flow with the
1218 * possibility of using the cached route in the socket if it is valid.
1219 * It will take the socket dst lock when operating on the dst cache.
1220 * As a result, this function can only be used in process context.
1221 *
1222 * In addition, for a connected socket, cache the dst in the socket
1223 * if the current cache is not valid.
1224 *
1225 * It returns a valid dst pointer on success, or a pointer encoded
1226 * error code.
1227 */
ip6_sk_dst_lookup_flow(struct sock * sk,struct flowi6 * fl6,const struct in6_addr * final_dst,bool connected)1228 struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
1229 const struct in6_addr *final_dst,
1230 bool connected)
1231 {
1232 struct dst_entry *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie);
1233
1234 dst = ip6_sk_dst_check(sk, dst, fl6);
1235 if (dst)
1236 return dst;
1237
1238 dst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_dst);
1239 if (connected && !IS_ERR(dst))
1240 ip6_sk_dst_store_flow(sk, dst_clone(dst), fl6);
1241
1242 return dst;
1243 }
1244 EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup_flow);
1245
1246 /**
1247 * ip6_dst_lookup_tunnel - perform route lookup on tunnel
1248 * @skb: Packet for which lookup is done
1249 * @dev: Tunnel device
1250 * @net: Network namespace of tunnel device
1251 * @sock: Socket which provides route info
1252 * @saddr: Memory to store the src ip address
1253 * @info: Tunnel information
1254 * @protocol: IP protocol
1255 * @use_cache: Flag to enable cache usage
1256 * This function performs a route lookup on a tunnel
1257 *
1258 * It returns a valid dst pointer and stores src address to be used in
1259 * tunnel in param saddr on success, else a pointer encoded error code.
1260 */
1261
ip6_dst_lookup_tunnel(struct sk_buff * skb,struct net_device * dev,struct net * net,struct socket * sock,struct in6_addr * saddr,const struct ip_tunnel_info * info,u8 protocol,bool use_cache)1262 struct dst_entry *ip6_dst_lookup_tunnel(struct sk_buff *skb,
1263 struct net_device *dev,
1264 struct net *net,
1265 struct socket *sock,
1266 struct in6_addr *saddr,
1267 const struct ip_tunnel_info *info,
1268 u8 protocol,
1269 bool use_cache)
1270 {
1271 struct dst_entry *dst = NULL;
1272 #ifdef CONFIG_DST_CACHE
1273 struct dst_cache *dst_cache;
1274 #endif
1275 struct flowi6 fl6;
1276 __u8 prio;
1277
1278 #ifdef CONFIG_DST_CACHE
1279 dst_cache = (struct dst_cache *)&info->dst_cache;
1280 if (use_cache) {
1281 dst = dst_cache_get_ip6(dst_cache, saddr);
1282 if (dst)
1283 return dst;
1284 }
1285 #endif
1286 memset(&fl6, 0, sizeof(fl6));
1287 fl6.flowi6_mark = skb->mark;
1288 fl6.flowi6_proto = protocol;
1289 fl6.daddr = info->key.u.ipv6.dst;
1290 fl6.saddr = info->key.u.ipv6.src;
1291 prio = info->key.tos;
1292 fl6.flowlabel = ip6_make_flowinfo(RT_TOS(prio),
1293 info->key.label);
1294
1295 dst = ipv6_stub->ipv6_dst_lookup_flow(net, sock->sk, &fl6,
1296 NULL);
1297 if (IS_ERR(dst)) {
1298 netdev_dbg(dev, "no route to %pI6\n", &fl6.daddr);
1299 return ERR_PTR(-ENETUNREACH);
1300 }
1301 if (dst->dev == dev) { /* is this necessary? */
1302 netdev_dbg(dev, "circular route to %pI6\n", &fl6.daddr);
1303 dst_release(dst);
1304 return ERR_PTR(-ELOOP);
1305 }
1306 #ifdef CONFIG_DST_CACHE
1307 if (use_cache)
1308 dst_cache_set_ip6(dst_cache, dst, &fl6.saddr);
1309 #endif
1310 *saddr = fl6.saddr;
1311 return dst;
1312 }
1313 EXPORT_SYMBOL_GPL(ip6_dst_lookup_tunnel);
1314
ip6_opt_dup(struct ipv6_opt_hdr * src,gfp_t gfp)1315 static inline struct ipv6_opt_hdr *ip6_opt_dup(struct ipv6_opt_hdr *src,
1316 gfp_t gfp)
1317 {
1318 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL;
1319 }
1320
ip6_rthdr_dup(struct ipv6_rt_hdr * src,gfp_t gfp)1321 static inline struct ipv6_rt_hdr *ip6_rthdr_dup(struct ipv6_rt_hdr *src,
1322 gfp_t gfp)
1323 {
1324 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL;
1325 }
1326
ip6_append_data_mtu(unsigned int * mtu,int * maxfraglen,unsigned int fragheaderlen,struct sk_buff * skb,struct rt6_info * rt,unsigned int orig_mtu)1327 static void ip6_append_data_mtu(unsigned int *mtu,
1328 int *maxfraglen,
1329 unsigned int fragheaderlen,
1330 struct sk_buff *skb,
1331 struct rt6_info *rt,
1332 unsigned int orig_mtu)
1333 {
1334 if (!(rt->dst.flags & DST_XFRM_TUNNEL)) {
1335 if (!skb) {
1336 /* first fragment, reserve header_len */
1337 *mtu = orig_mtu - rt->dst.header_len;
1338
1339 } else {
1340 /*
1341 * this fragment is not first, the headers
1342 * space is regarded as data space.
1343 */
1344 *mtu = orig_mtu;
1345 }
1346 *maxfraglen = ((*mtu - fragheaderlen) & ~7)
1347 + fragheaderlen - sizeof(struct frag_hdr);
1348 }
1349 }
1350
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)1351 static int ip6_setup_cork(struct sock *sk, struct inet_cork_full *cork,
1352 struct inet6_cork *v6_cork, struct ipcm6_cookie *ipc6,
1353 struct rt6_info *rt, struct flowi6 *fl6)
1354 {
1355 struct ipv6_pinfo *np = inet6_sk(sk);
1356 unsigned int mtu;
1357 struct ipv6_txoptions *opt = ipc6->opt;
1358
1359 /*
1360 * setup for corking
1361 */
1362 if (opt) {
1363 if (WARN_ON(v6_cork->opt))
1364 return -EINVAL;
1365
1366 v6_cork->opt = kzalloc(sizeof(*opt), sk->sk_allocation);
1367 if (unlikely(!v6_cork->opt))
1368 return -ENOBUFS;
1369
1370 v6_cork->opt->tot_len = sizeof(*opt);
1371 v6_cork->opt->opt_flen = opt->opt_flen;
1372 v6_cork->opt->opt_nflen = opt->opt_nflen;
1373
1374 v6_cork->opt->dst0opt = ip6_opt_dup(opt->dst0opt,
1375 sk->sk_allocation);
1376 if (opt->dst0opt && !v6_cork->opt->dst0opt)
1377 return -ENOBUFS;
1378
1379 v6_cork->opt->dst1opt = ip6_opt_dup(opt->dst1opt,
1380 sk->sk_allocation);
1381 if (opt->dst1opt && !v6_cork->opt->dst1opt)
1382 return -ENOBUFS;
1383
1384 v6_cork->opt->hopopt = ip6_opt_dup(opt->hopopt,
1385 sk->sk_allocation);
1386 if (opt->hopopt && !v6_cork->opt->hopopt)
1387 return -ENOBUFS;
1388
1389 v6_cork->opt->srcrt = ip6_rthdr_dup(opt->srcrt,
1390 sk->sk_allocation);
1391 if (opt->srcrt && !v6_cork->opt->srcrt)
1392 return -ENOBUFS;
1393
1394 /* need source address above miyazawa*/
1395 }
1396 dst_hold(&rt->dst);
1397 cork->base.dst = &rt->dst;
1398 cork->fl.u.ip6 = *fl6;
1399 v6_cork->hop_limit = ipc6->hlimit;
1400 v6_cork->tclass = ipc6->tclass;
1401 if (rt->dst.flags & DST_XFRM_TUNNEL)
1402 mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ?
1403 READ_ONCE(rt->dst.dev->mtu) : dst_mtu(&rt->dst);
1404 else
1405 mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ?
1406 READ_ONCE(rt->dst.dev->mtu) : dst_mtu(xfrm_dst_path(&rt->dst));
1407 if (np->frag_size < mtu) {
1408 if (np->frag_size)
1409 mtu = np->frag_size;
1410 }
1411 if (mtu < IPV6_MIN_MTU)
1412 return -EINVAL;
1413 cork->base.fragsize = mtu;
1414 cork->base.gso_size = ipc6->gso_size;
1415 cork->base.tx_flags = 0;
1416 cork->base.mark = ipc6->sockc.mark;
1417 sock_tx_timestamp(sk, ipc6->sockc.tsflags, &cork->base.tx_flags);
1418
1419 if (dst_allfrag(xfrm_dst_path(&rt->dst)))
1420 cork->base.flags |= IPCORK_ALLFRAG;
1421 cork->base.length = 0;
1422
1423 cork->base.transmit_time = ipc6->sockc.transmit_time;
1424
1425 return 0;
1426 }
1427
__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)1428 static int __ip6_append_data(struct sock *sk,
1429 struct flowi6 *fl6,
1430 struct sk_buff_head *queue,
1431 struct inet_cork *cork,
1432 struct inet6_cork *v6_cork,
1433 struct page_frag *pfrag,
1434 int getfrag(void *from, char *to, int offset,
1435 int len, int odd, struct sk_buff *skb),
1436 void *from, int length, int transhdrlen,
1437 unsigned int flags, struct ipcm6_cookie *ipc6)
1438 {
1439 struct sk_buff *skb, *skb_prev = NULL;
1440 unsigned int maxfraglen, fragheaderlen, mtu, orig_mtu, pmtu;
1441 struct ubuf_info *uarg = NULL;
1442 int exthdrlen = 0;
1443 int dst_exthdrlen = 0;
1444 int hh_len;
1445 int copy;
1446 int err;
1447 int offset = 0;
1448 u32 tskey = 0;
1449 struct rt6_info *rt = (struct rt6_info *)cork->dst;
1450 struct ipv6_txoptions *opt = v6_cork->opt;
1451 int csummode = CHECKSUM_NONE;
1452 unsigned int maxnonfragsize, headersize;
1453 unsigned int wmem_alloc_delta = 0;
1454 bool paged, extra_uref = false;
1455
1456 skb = skb_peek_tail(queue);
1457 if (!skb) {
1458 exthdrlen = opt ? opt->opt_flen : 0;
1459 dst_exthdrlen = rt->dst.header_len - rt->rt6i_nfheader_len;
1460 }
1461
1462 paged = !!cork->gso_size;
1463 mtu = cork->gso_size ? IP6_MAX_MTU : cork->fragsize;
1464 orig_mtu = mtu;
1465
1466 if (cork->tx_flags & SKBTX_ANY_SW_TSTAMP &&
1467 sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)
1468 tskey = sk->sk_tskey++;
1469
1470 hh_len = LL_RESERVED_SPACE(rt->dst.dev);
1471
1472 fragheaderlen = sizeof(struct ipv6hdr) + rt->rt6i_nfheader_len +
1473 (opt ? opt->opt_nflen : 0);
1474 maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen -
1475 sizeof(struct frag_hdr);
1476
1477 headersize = sizeof(struct ipv6hdr) +
1478 (opt ? opt->opt_flen + opt->opt_nflen : 0) +
1479 (dst_allfrag(&rt->dst) ?
1480 sizeof(struct frag_hdr) : 0) +
1481 rt->rt6i_nfheader_len;
1482
1483 /* as per RFC 7112 section 5, the entire IPv6 Header Chain must fit
1484 * the first fragment
1485 */
1486 if (headersize + transhdrlen > mtu)
1487 goto emsgsize;
1488
1489 if (cork->length + length > mtu - headersize && ipc6->dontfrag &&
1490 (sk->sk_protocol == IPPROTO_UDP ||
1491 sk->sk_protocol == IPPROTO_RAW)) {
1492 ipv6_local_rxpmtu(sk, fl6, mtu - headersize +
1493 sizeof(struct ipv6hdr));
1494 goto emsgsize;
1495 }
1496
1497 if (ip6_sk_ignore_df(sk))
1498 maxnonfragsize = sizeof(struct ipv6hdr) + IPV6_MAXPLEN;
1499 else
1500 maxnonfragsize = mtu;
1501
1502 if (cork->length + length > maxnonfragsize - headersize) {
1503 emsgsize:
1504 pmtu = max_t(int, mtu - headersize + sizeof(struct ipv6hdr), 0);
1505 ipv6_local_error(sk, EMSGSIZE, fl6, pmtu);
1506 return -EMSGSIZE;
1507 }
1508
1509 /* CHECKSUM_PARTIAL only with no extension headers and when
1510 * we are not going to fragment
1511 */
1512 if (transhdrlen && sk->sk_protocol == IPPROTO_UDP &&
1513 headersize == sizeof(struct ipv6hdr) &&
1514 length <= mtu - headersize &&
1515 (!(flags & MSG_MORE) || cork->gso_size) &&
1516 rt->dst.dev->features & (NETIF_F_IPV6_CSUM | NETIF_F_HW_CSUM))
1517 csummode = CHECKSUM_PARTIAL;
1518
1519 if (flags & MSG_ZEROCOPY && length && sock_flag(sk, SOCK_ZEROCOPY)) {
1520 uarg = msg_zerocopy_realloc(sk, length, skb_zcopy(skb));
1521 if (!uarg)
1522 return -ENOBUFS;
1523 extra_uref = !skb_zcopy(skb); /* only ref on new uarg */
1524 if (rt->dst.dev->features & NETIF_F_SG &&
1525 csummode == CHECKSUM_PARTIAL) {
1526 paged = true;
1527 } else {
1528 uarg->zerocopy = 0;
1529 skb_zcopy_set(skb, uarg, &extra_uref);
1530 }
1531 }
1532
1533 /*
1534 * Let's try using as much space as possible.
1535 * Use MTU if total length of the message fits into the MTU.
1536 * Otherwise, we need to reserve fragment header and
1537 * fragment alignment (= 8-15 octects, in total).
1538 *
1539 * Note that we may need to "move" the data from the tail
1540 * of the buffer to the new fragment when we split
1541 * the message.
1542 *
1543 * FIXME: It may be fragmented into multiple chunks
1544 * at once if non-fragmentable extension headers
1545 * are too large.
1546 * --yoshfuji
1547 */
1548
1549 cork->length += length;
1550 if (!skb)
1551 goto alloc_new_skb;
1552
1553 while (length > 0) {
1554 /* Check if the remaining data fits into current packet. */
1555 copy = (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len;
1556 if (copy < length)
1557 copy = maxfraglen - skb->len;
1558
1559 if (copy <= 0) {
1560 char *data;
1561 unsigned int datalen;
1562 unsigned int fraglen;
1563 unsigned int fraggap;
1564 unsigned int alloclen, alloc_extra;
1565 unsigned int pagedlen;
1566 alloc_new_skb:
1567 /* There's no room in the current skb */
1568 if (skb)
1569 fraggap = skb->len - maxfraglen;
1570 else
1571 fraggap = 0;
1572 /* update mtu and maxfraglen if necessary */
1573 if (!skb || !skb_prev)
1574 ip6_append_data_mtu(&mtu, &maxfraglen,
1575 fragheaderlen, skb, rt,
1576 orig_mtu);
1577
1578 skb_prev = skb;
1579
1580 /*
1581 * If remaining data exceeds the mtu,
1582 * we know we need more fragment(s).
1583 */
1584 datalen = length + fraggap;
1585
1586 if (datalen > (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen)
1587 datalen = maxfraglen - fragheaderlen - rt->dst.trailer_len;
1588 fraglen = datalen + fragheaderlen;
1589 pagedlen = 0;
1590
1591 alloc_extra = hh_len;
1592 alloc_extra += dst_exthdrlen;
1593 alloc_extra += rt->dst.trailer_len;
1594
1595 /* We just reserve space for fragment header.
1596 * Note: this may be overallocation if the message
1597 * (without MSG_MORE) fits into the MTU.
1598 */
1599 alloc_extra += sizeof(struct frag_hdr);
1600
1601 if ((flags & MSG_MORE) &&
1602 !(rt->dst.dev->features&NETIF_F_SG))
1603 alloclen = mtu;
1604 else if (!paged &&
1605 (fraglen + alloc_extra < SKB_MAX_ALLOC ||
1606 !(rt->dst.dev->features & NETIF_F_SG)))
1607 alloclen = fraglen;
1608 else {
1609 alloclen = min_t(int, fraglen, MAX_HEADER);
1610 pagedlen = fraglen - alloclen;
1611 }
1612 alloclen += alloc_extra;
1613
1614 if (datalen != length + fraggap) {
1615 /*
1616 * this is not the last fragment, the trailer
1617 * space is regarded as data space.
1618 */
1619 datalen += rt->dst.trailer_len;
1620 }
1621
1622 fraglen = datalen + fragheaderlen;
1623
1624 copy = datalen - transhdrlen - fraggap - pagedlen;
1625 if (copy < 0) {
1626 err = -EINVAL;
1627 goto error;
1628 }
1629 if (transhdrlen) {
1630 skb = sock_alloc_send_skb(sk, alloclen,
1631 (flags & MSG_DONTWAIT), &err);
1632 } else {
1633 skb = NULL;
1634 if (refcount_read(&sk->sk_wmem_alloc) + wmem_alloc_delta <=
1635 2 * sk->sk_sndbuf)
1636 skb = alloc_skb(alloclen,
1637 sk->sk_allocation);
1638 if (unlikely(!skb))
1639 err = -ENOBUFS;
1640 }
1641 if (!skb)
1642 goto error;
1643 /*
1644 * Fill in the control structures
1645 */
1646 skb->protocol = htons(ETH_P_IPV6);
1647 skb->ip_summed = csummode;
1648 skb->csum = 0;
1649 /* reserve for fragmentation and ipsec header */
1650 skb_reserve(skb, hh_len + sizeof(struct frag_hdr) +
1651 dst_exthdrlen);
1652
1653 /*
1654 * Find where to start putting bytes
1655 */
1656 data = skb_put(skb, fraglen - pagedlen);
1657 skb_set_network_header(skb, exthdrlen);
1658 data += fragheaderlen;
1659 skb->transport_header = (skb->network_header +
1660 fragheaderlen);
1661 if (fraggap) {
1662 skb->csum = skb_copy_and_csum_bits(
1663 skb_prev, maxfraglen,
1664 data + transhdrlen, fraggap);
1665 skb_prev->csum = csum_sub(skb_prev->csum,
1666 skb->csum);
1667 data += fraggap;
1668 pskb_trim_unique(skb_prev, maxfraglen);
1669 }
1670 if (copy > 0 &&
1671 getfrag(from, data + transhdrlen, offset,
1672 copy, fraggap, skb) < 0) {
1673 err = -EFAULT;
1674 kfree_skb(skb);
1675 goto error;
1676 }
1677
1678 offset += copy;
1679 length -= copy + transhdrlen;
1680 transhdrlen = 0;
1681 exthdrlen = 0;
1682 dst_exthdrlen = 0;
1683
1684 /* Only the initial fragment is time stamped */
1685 skb_shinfo(skb)->tx_flags = cork->tx_flags;
1686 cork->tx_flags = 0;
1687 skb_shinfo(skb)->tskey = tskey;
1688 tskey = 0;
1689 skb_zcopy_set(skb, uarg, &extra_uref);
1690
1691 if ((flags & MSG_CONFIRM) && !skb_prev)
1692 skb_set_dst_pending_confirm(skb, 1);
1693
1694 /*
1695 * Put the packet on the pending queue
1696 */
1697 if (!skb->destructor) {
1698 skb->destructor = sock_wfree;
1699 skb->sk = sk;
1700 wmem_alloc_delta += skb->truesize;
1701 }
1702 __skb_queue_tail(queue, skb);
1703 continue;
1704 }
1705
1706 if (copy > length)
1707 copy = length;
1708
1709 if (!(rt->dst.dev->features&NETIF_F_SG) &&
1710 skb_tailroom(skb) >= copy) {
1711 unsigned int off;
1712
1713 off = skb->len;
1714 if (getfrag(from, skb_put(skb, copy),
1715 offset, copy, off, skb) < 0) {
1716 __skb_trim(skb, off);
1717 err = -EFAULT;
1718 goto error;
1719 }
1720 } else if (!uarg || !uarg->zerocopy) {
1721 int i = skb_shinfo(skb)->nr_frags;
1722
1723 err = -ENOMEM;
1724 if (!sk_page_frag_refill(sk, pfrag))
1725 goto error;
1726
1727 if (!skb_can_coalesce(skb, i, pfrag->page,
1728 pfrag->offset)) {
1729 err = -EMSGSIZE;
1730 if (i == MAX_SKB_FRAGS)
1731 goto error;
1732
1733 __skb_fill_page_desc(skb, i, pfrag->page,
1734 pfrag->offset, 0);
1735 skb_shinfo(skb)->nr_frags = ++i;
1736 get_page(pfrag->page);
1737 }
1738 copy = min_t(int, copy, pfrag->size - pfrag->offset);
1739 if (getfrag(from,
1740 page_address(pfrag->page) + pfrag->offset,
1741 offset, copy, skb->len, skb) < 0)
1742 goto error_efault;
1743
1744 pfrag->offset += copy;
1745 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
1746 skb->len += copy;
1747 skb->data_len += copy;
1748 skb->truesize += copy;
1749 wmem_alloc_delta += copy;
1750 } else {
1751 err = skb_zerocopy_iter_dgram(skb, from, copy);
1752 if (err < 0)
1753 goto error;
1754 }
1755 offset += copy;
1756 length -= copy;
1757 }
1758
1759 if (wmem_alloc_delta)
1760 refcount_add(wmem_alloc_delta, &sk->sk_wmem_alloc);
1761 return 0;
1762
1763 error_efault:
1764 err = -EFAULT;
1765 error:
1766 net_zcopy_put_abort(uarg, extra_uref);
1767 cork->length -= length;
1768 IP6_INC_STATS(sock_net(sk), rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS);
1769 refcount_add(wmem_alloc_delta, &sk->sk_wmem_alloc);
1770 return err;
1771 }
1772
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)1773 int ip6_append_data(struct sock *sk,
1774 int getfrag(void *from, char *to, int offset, int len,
1775 int odd, struct sk_buff *skb),
1776 void *from, int length, int transhdrlen,
1777 struct ipcm6_cookie *ipc6, struct flowi6 *fl6,
1778 struct rt6_info *rt, unsigned int flags)
1779 {
1780 struct inet_sock *inet = inet_sk(sk);
1781 struct ipv6_pinfo *np = inet6_sk(sk);
1782 int exthdrlen;
1783 int err;
1784
1785 if (flags&MSG_PROBE)
1786 return 0;
1787 if (skb_queue_empty(&sk->sk_write_queue)) {
1788 /*
1789 * setup for corking
1790 */
1791 err = ip6_setup_cork(sk, &inet->cork, &np->cork,
1792 ipc6, rt, fl6);
1793 if (err)
1794 return err;
1795
1796 exthdrlen = (ipc6->opt ? ipc6->opt->opt_flen : 0);
1797 length += exthdrlen;
1798 transhdrlen += exthdrlen;
1799 } else {
1800 fl6 = &inet->cork.fl.u.ip6;
1801 transhdrlen = 0;
1802 }
1803
1804 return __ip6_append_data(sk, fl6, &sk->sk_write_queue, &inet->cork.base,
1805 &np->cork, sk_page_frag(sk), getfrag,
1806 from, length, transhdrlen, flags, ipc6);
1807 }
1808 EXPORT_SYMBOL_GPL(ip6_append_data);
1809
ip6_cork_release(struct inet_cork_full * cork,struct inet6_cork * v6_cork)1810 static void ip6_cork_release(struct inet_cork_full *cork,
1811 struct inet6_cork *v6_cork)
1812 {
1813 if (v6_cork->opt) {
1814 kfree(v6_cork->opt->dst0opt);
1815 kfree(v6_cork->opt->dst1opt);
1816 kfree(v6_cork->opt->hopopt);
1817 kfree(v6_cork->opt->srcrt);
1818 kfree(v6_cork->opt);
1819 v6_cork->opt = NULL;
1820 }
1821
1822 if (cork->base.dst) {
1823 dst_release(cork->base.dst);
1824 cork->base.dst = NULL;
1825 cork->base.flags &= ~IPCORK_ALLFRAG;
1826 }
1827 memset(&cork->fl, 0, sizeof(cork->fl));
1828 }
1829
__ip6_make_skb(struct sock * sk,struct sk_buff_head * queue,struct inet_cork_full * cork,struct inet6_cork * v6_cork)1830 struct sk_buff *__ip6_make_skb(struct sock *sk,
1831 struct sk_buff_head *queue,
1832 struct inet_cork_full *cork,
1833 struct inet6_cork *v6_cork)
1834 {
1835 struct sk_buff *skb, *tmp_skb;
1836 struct sk_buff **tail_skb;
1837 struct in6_addr final_dst_buf, *final_dst = &final_dst_buf;
1838 struct ipv6_pinfo *np = inet6_sk(sk);
1839 struct net *net = sock_net(sk);
1840 struct ipv6hdr *hdr;
1841 struct ipv6_txoptions *opt = v6_cork->opt;
1842 struct rt6_info *rt = (struct rt6_info *)cork->base.dst;
1843 struct flowi6 *fl6 = &cork->fl.u.ip6;
1844 unsigned char proto = fl6->flowi6_proto;
1845
1846 skb = __skb_dequeue(queue);
1847 if (!skb)
1848 goto out;
1849 tail_skb = &(skb_shinfo(skb)->frag_list);
1850
1851 /* move skb->data to ip header from ext header */
1852 if (skb->data < skb_network_header(skb))
1853 __skb_pull(skb, skb_network_offset(skb));
1854 while ((tmp_skb = __skb_dequeue(queue)) != NULL) {
1855 __skb_pull(tmp_skb, skb_network_header_len(skb));
1856 *tail_skb = tmp_skb;
1857 tail_skb = &(tmp_skb->next);
1858 skb->len += tmp_skb->len;
1859 skb->data_len += tmp_skb->len;
1860 skb->truesize += tmp_skb->truesize;
1861 tmp_skb->destructor = NULL;
1862 tmp_skb->sk = NULL;
1863 }
1864
1865 /* Allow local fragmentation. */
1866 skb->ignore_df = ip6_sk_ignore_df(sk);
1867
1868 *final_dst = fl6->daddr;
1869 __skb_pull(skb, skb_network_header_len(skb));
1870 if (opt && opt->opt_flen)
1871 ipv6_push_frag_opts(skb, opt, &proto);
1872 if (opt && opt->opt_nflen)
1873 ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst, &fl6->saddr);
1874
1875 skb_push(skb, sizeof(struct ipv6hdr));
1876 skb_reset_network_header(skb);
1877 hdr = ipv6_hdr(skb);
1878
1879 ip6_flow_hdr(hdr, v6_cork->tclass,
1880 ip6_make_flowlabel(net, skb, fl6->flowlabel,
1881 ip6_autoflowlabel(net, np), fl6));
1882 hdr->hop_limit = v6_cork->hop_limit;
1883 hdr->nexthdr = proto;
1884 hdr->saddr = fl6->saddr;
1885 hdr->daddr = *final_dst;
1886
1887 skb->priority = sk->sk_priority;
1888 skb->mark = cork->base.mark;
1889
1890 skb->tstamp = cork->base.transmit_time;
1891
1892 skb_dst_set(skb, dst_clone(&rt->dst));
1893 IP6_UPD_PO_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUT, skb->len);
1894 if (proto == IPPROTO_ICMPV6) {
1895 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
1896
1897 ICMP6MSGOUT_INC_STATS(net, idev, icmp6_hdr(skb)->icmp6_type);
1898 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
1899 }
1900
1901 ip6_cork_release(cork, v6_cork);
1902 out:
1903 return skb;
1904 }
1905
ip6_send_skb(struct sk_buff * skb)1906 int ip6_send_skb(struct sk_buff *skb)
1907 {
1908 struct net *net = sock_net(skb->sk);
1909 struct rt6_info *rt = (struct rt6_info *)skb_dst(skb);
1910 int err;
1911
1912 err = ip6_local_out(net, skb->sk, skb);
1913 if (err) {
1914 if (err > 0)
1915 err = net_xmit_errno(err);
1916 if (err)
1917 IP6_INC_STATS(net, rt->rt6i_idev,
1918 IPSTATS_MIB_OUTDISCARDS);
1919 }
1920
1921 return err;
1922 }
1923
ip6_push_pending_frames(struct sock * sk)1924 int ip6_push_pending_frames(struct sock *sk)
1925 {
1926 struct sk_buff *skb;
1927
1928 skb = ip6_finish_skb(sk);
1929 if (!skb)
1930 return 0;
1931
1932 return ip6_send_skb(skb);
1933 }
1934 EXPORT_SYMBOL_GPL(ip6_push_pending_frames);
1935
__ip6_flush_pending_frames(struct sock * sk,struct sk_buff_head * queue,struct inet_cork_full * cork,struct inet6_cork * v6_cork)1936 static void __ip6_flush_pending_frames(struct sock *sk,
1937 struct sk_buff_head *queue,
1938 struct inet_cork_full *cork,
1939 struct inet6_cork *v6_cork)
1940 {
1941 struct sk_buff *skb;
1942
1943 while ((skb = __skb_dequeue_tail(queue)) != NULL) {
1944 if (skb_dst(skb))
1945 IP6_INC_STATS(sock_net(sk), ip6_dst_idev(skb_dst(skb)),
1946 IPSTATS_MIB_OUTDISCARDS);
1947 kfree_skb(skb);
1948 }
1949
1950 ip6_cork_release(cork, v6_cork);
1951 }
1952
ip6_flush_pending_frames(struct sock * sk)1953 void ip6_flush_pending_frames(struct sock *sk)
1954 {
1955 __ip6_flush_pending_frames(sk, &sk->sk_write_queue,
1956 &inet_sk(sk)->cork, &inet6_sk(sk)->cork);
1957 }
1958 EXPORT_SYMBOL_GPL(ip6_flush_pending_frames);
1959
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)1960 struct sk_buff *ip6_make_skb(struct sock *sk,
1961 int getfrag(void *from, char *to, int offset,
1962 int len, int odd, struct sk_buff *skb),
1963 void *from, int length, int transhdrlen,
1964 struct ipcm6_cookie *ipc6, struct flowi6 *fl6,
1965 struct rt6_info *rt, unsigned int flags,
1966 struct inet_cork_full *cork)
1967 {
1968 struct inet6_cork v6_cork;
1969 struct sk_buff_head queue;
1970 int exthdrlen = (ipc6->opt ? ipc6->opt->opt_flen : 0);
1971 int err;
1972
1973 if (flags & MSG_PROBE)
1974 return NULL;
1975
1976 __skb_queue_head_init(&queue);
1977
1978 cork->base.flags = 0;
1979 cork->base.addr = 0;
1980 cork->base.opt = NULL;
1981 cork->base.dst = NULL;
1982 v6_cork.opt = NULL;
1983 err = ip6_setup_cork(sk, cork, &v6_cork, ipc6, rt, fl6);
1984 if (err) {
1985 ip6_cork_release(cork, &v6_cork);
1986 return ERR_PTR(err);
1987 }
1988 if (ipc6->dontfrag < 0)
1989 ipc6->dontfrag = inet6_sk(sk)->dontfrag;
1990
1991 err = __ip6_append_data(sk, fl6, &queue, &cork->base, &v6_cork,
1992 ¤t->task_frag, getfrag, from,
1993 length + exthdrlen, transhdrlen + exthdrlen,
1994 flags, ipc6);
1995 if (err) {
1996 __ip6_flush_pending_frames(sk, &queue, cork, &v6_cork);
1997 return ERR_PTR(err);
1998 }
1999
2000 return __ip6_make_skb(sk, &queue, cork, &v6_cork);
2001 }
2002
