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1 | /* |
2 | * IPv6 output functions |
3 | * Linux INET6 implementation |
4 | * |
5 | * Authors: |
6 | * Pedro Roque <roque@di.fc.ul.pt> |
7 | * |
8 | * Based on linux/net/ipv4/ip_output.c |
9 | * |
10 | * This program is free software; you can redistribute it and/or |
11 | * modify it under the terms of the GNU General Public License |
12 | * as published by the Free Software Foundation; either version |
13 | * 2 of the License, or (at your option) any later version. |
14 | * |
15 | * Changes: |
16 | * A.N.Kuznetsov : airthmetics in fragmentation. |
17 | * extension headers are implemented. |
18 | * route changes now work. |
19 | * ip6_forward does not confuse sniffers. |
20 | * etc. |
21 | * |
22 | * H. von Brand : Added missing #include <linux/string.h> |
23 | * Imran Patel : frag id should be in NBO |
24 | * Kazunori MIYAZAWA @USAGI |
25 | * : add ip6_append_data and related functions |
26 | * for datagram xmit |
27 | */ |
28 | |
29 | #include <linux/errno.h> |
30 | #include <linux/kernel.h> |
31 | #include <linux/string.h> |
32 | #include <linux/socket.h> |
33 | #include <linux/net.h> |
34 | #include <linux/netdevice.h> |
35 | #include <linux/if_arp.h> |
36 | #include <linux/in6.h> |
37 | #include <linux/tcp.h> |
38 | #include <linux/route.h> |
39 | #include <linux/module.h> |
40 | #include <linux/slab.h> |
41 | |
42 | #include <linux/netfilter.h> |
43 | #include <linux/netfilter_ipv6.h> |
44 | |
45 | #include <net/sock.h> |
46 | #include <net/snmp.h> |
47 | |
48 | #include <net/ipv6.h> |
49 | #include <net/ndisc.h> |
50 | #include <net/protocol.h> |
51 | #include <net/ip6_route.h> |
52 | #include <net/addrconf.h> |
53 | #include <net/rawv6.h> |
54 | #include <net/icmp.h> |
55 | #include <net/xfrm.h> |
56 | #include <net/checksum.h> |
57 | #include <linux/mroute6.h> |
58 | |
59 | static int ip6_finish_output2(struct sk_buff *skb) |
60 | { |
61 | struct dst_entry *dst = skb_dst(skb); |
62 | struct net_device *dev = dst->dev; |
63 | struct neighbour *neigh; |
64 | struct in6_addr *nexthop; |
65 | int ret; |
66 | |
67 | skb->protocol = htons(ETH_P_IPV6); |
68 | skb->dev = dev; |
69 | |
70 | if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) { |
71 | struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); |
72 | |
73 | if (!(dev->flags & IFF_LOOPBACK) && sk_mc_loop(skb->sk) && |
74 | ((mroute6_socket(dev_net(dev), skb) && |
75 | !(IP6CB(skb)->flags & IP6SKB_FORWARDED)) || |
76 | ipv6_chk_mcast_addr(dev, &ipv6_hdr(skb)->daddr, |
77 | &ipv6_hdr(skb)->saddr))) { |
78 | struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); |
79 | |
80 | /* Do not check for IFF_ALLMULTI; multicast routing |
81 | is not supported in any case. |
82 | */ |
83 | if (newskb) |
84 | NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING, |
85 | newskb, NULL, newskb->dev, |
86 | dev_loopback_xmit); |
87 | |
88 | if (ipv6_hdr(skb)->hop_limit == 0) { |
89 | IP6_INC_STATS(dev_net(dev), idev, |
90 | IPSTATS_MIB_OUTDISCARDS); |
91 | kfree_skb(skb); |
92 | return 0; |
93 | } |
94 | } |
95 | |
96 | IP6_UPD_PO_STATS(dev_net(dev), idev, IPSTATS_MIB_OUTMCAST, |
97 | skb->len); |
98 | |
99 | if (IPV6_ADDR_MC_SCOPE(&ipv6_hdr(skb)->daddr) <= |
100 | IPV6_ADDR_SCOPE_NODELOCAL && |
101 | !(dev->flags & IFF_LOOPBACK)) { |
102 | kfree_skb(skb); |
103 | return 0; |
104 | } |
105 | } |
106 | |
107 | rcu_read_lock_bh(); |
108 | nexthop = rt6_nexthop((struct rt6_info *)dst); |
109 | neigh = __ipv6_neigh_lookup_noref(dst->dev, nexthop); |
110 | if (unlikely(!neigh)) |
111 | neigh = __neigh_create(&nd_tbl, nexthop, dst->dev, false); |
112 | if (!IS_ERR(neigh)) { |
113 | ret = dst_neigh_output(dst, neigh, skb); |
114 | rcu_read_unlock_bh(); |
115 | return ret; |
116 | } |
117 | rcu_read_unlock_bh(); |
118 | |
119 | IP6_INC_STATS(dev_net(dst->dev), |
120 | ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES); |
121 | kfree_skb(skb); |
122 | return -EINVAL; |
123 | } |
124 | |
125 | static int ip6_finish_output(struct sk_buff *skb) |
126 | { |
127 | if ((skb->len > ip6_skb_dst_mtu(skb) && !skb_is_gso(skb)) || |
128 | dst_allfrag(skb_dst(skb)) || |
129 | (IP6CB(skb)->frag_max_size && skb->len > IP6CB(skb)->frag_max_size)) |
130 | return ip6_fragment(skb, ip6_finish_output2); |
131 | else |
132 | return ip6_finish_output2(skb); |
133 | } |
134 | |
135 | int ip6_output(struct sock *sk, struct sk_buff *skb) |
136 | { |
137 | struct net_device *dev = skb_dst(skb)->dev; |
138 | struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); |
139 | if (unlikely(idev->cnf.disable_ipv6)) { |
140 | IP6_INC_STATS(dev_net(dev), idev, |
141 | IPSTATS_MIB_OUTDISCARDS); |
142 | kfree_skb(skb); |
143 | return 0; |
144 | } |
145 | |
146 | return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING, skb, NULL, dev, |
147 | ip6_finish_output, |
148 | !(IP6CB(skb)->flags & IP6SKB_REROUTED)); |
149 | } |
150 | |
151 | /* |
152 | * xmit an sk_buff (used by TCP, SCTP and DCCP) |
153 | */ |
154 | |
155 | int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6, |
156 | struct ipv6_txoptions *opt, int tclass) |
157 | { |
158 | struct net *net = sock_net(sk); |
159 | struct ipv6_pinfo *np = inet6_sk(sk); |
160 | struct in6_addr *first_hop = &fl6->daddr; |
161 | struct dst_entry *dst = skb_dst(skb); |
162 | struct ipv6hdr *hdr; |
163 | u8 proto = fl6->flowi6_proto; |
164 | int seg_len = skb->len; |
165 | int hlimit = -1; |
166 | u32 mtu; |
167 | |
168 | if (opt) { |
169 | unsigned int head_room; |
170 | |
171 | /* First: exthdrs may take lots of space (~8K for now) |
172 | MAX_HEADER is not enough. |
173 | */ |
174 | head_room = opt->opt_nflen + opt->opt_flen; |
175 | seg_len += head_room; |
176 | head_room += sizeof(struct ipv6hdr) + LL_RESERVED_SPACE(dst->dev); |
177 | |
178 | if (skb_headroom(skb) < head_room) { |
179 | struct sk_buff *skb2 = skb_realloc_headroom(skb, head_room); |
180 | if (skb2 == NULL) { |
181 | IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), |
182 | IPSTATS_MIB_OUTDISCARDS); |
183 | kfree_skb(skb); |
184 | return -ENOBUFS; |
185 | } |
186 | consume_skb(skb); |
187 | skb = skb2; |
188 | skb_set_owner_w(skb, sk); |
189 | } |
190 | if (opt->opt_flen) |
191 | ipv6_push_frag_opts(skb, opt, &proto); |
192 | if (opt->opt_nflen) |
193 | ipv6_push_nfrag_opts(skb, opt, &proto, &first_hop); |
194 | } |
195 | |
196 | skb_push(skb, sizeof(struct ipv6hdr)); |
197 | skb_reset_network_header(skb); |
198 | hdr = ipv6_hdr(skb); |
199 | |
200 | /* |
201 | * Fill in the IPv6 header |
202 | */ |
203 | if (np) |
204 | hlimit = np->hop_limit; |
205 | if (hlimit < 0) |
206 | hlimit = ip6_dst_hoplimit(dst); |
207 | |
208 | ip6_flow_hdr(hdr, tclass, fl6->flowlabel); |
209 | |
210 | hdr->payload_len = htons(seg_len); |
211 | hdr->nexthdr = proto; |
212 | hdr->hop_limit = hlimit; |
213 | |
214 | hdr->saddr = fl6->saddr; |
215 | hdr->daddr = *first_hop; |
216 | |
217 | skb->protocol = htons(ETH_P_IPV6); |
218 | skb->priority = sk->sk_priority; |
219 | skb->mark = sk->sk_mark; |
220 | |
221 | mtu = dst_mtu(dst); |
222 | if ((skb->len <= mtu) || skb->local_df || skb_is_gso(skb)) { |
223 | IP6_UPD_PO_STATS(net, ip6_dst_idev(skb_dst(skb)), |
224 | IPSTATS_MIB_OUT, skb->len); |
225 | return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, skb, NULL, |
226 | dst->dev, dst_output); |
227 | } |
228 | |
229 | skb->dev = dst->dev; |
230 | ipv6_local_error(sk, EMSGSIZE, fl6, mtu); |
231 | IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_FRAGFAILS); |
232 | kfree_skb(skb); |
233 | return -EMSGSIZE; |
234 | } |
235 | |
236 | EXPORT_SYMBOL(ip6_xmit); |
237 | |
238 | static int ip6_call_ra_chain(struct sk_buff *skb, int sel) |
239 | { |
240 | struct ip6_ra_chain *ra; |
241 | struct sock *last = NULL; |
242 | |
243 | read_lock(&ip6_ra_lock); |
244 | for (ra = ip6_ra_chain; ra; ra = ra->next) { |
245 | struct sock *sk = ra->sk; |
246 | if (sk && ra->sel == sel && |
247 | (!sk->sk_bound_dev_if || |
248 | sk->sk_bound_dev_if == skb->dev->ifindex)) { |
249 | if (last) { |
250 | struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); |
251 | if (skb2) |
252 | rawv6_rcv(last, skb2); |
253 | } |
254 | last = sk; |
255 | } |
256 | } |
257 | |
258 | if (last) { |
259 | rawv6_rcv(last, skb); |
260 | read_unlock(&ip6_ra_lock); |
261 | return 1; |
262 | } |
263 | read_unlock(&ip6_ra_lock); |
264 | return 0; |
265 | } |
266 | |
267 | static int ip6_forward_proxy_check(struct sk_buff *skb) |
268 | { |
269 | struct ipv6hdr *hdr = ipv6_hdr(skb); |
270 | u8 nexthdr = hdr->nexthdr; |
271 | __be16 frag_off; |
272 | int offset; |
273 | |
274 | if (ipv6_ext_hdr(nexthdr)) { |
275 | offset = ipv6_skip_exthdr(skb, sizeof(*hdr), &nexthdr, &frag_off); |
276 | if (offset < 0) |
277 | return 0; |
278 | } else |
279 | offset = sizeof(struct ipv6hdr); |
280 | |
281 | if (nexthdr == IPPROTO_ICMPV6) { |
282 | struct icmp6hdr *icmp6; |
283 | |
284 | if (!pskb_may_pull(skb, (skb_network_header(skb) + |
285 | offset + 1 - skb->data))) |
286 | return 0; |
287 | |
288 | icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset); |
289 | |
290 | switch (icmp6->icmp6_type) { |
291 | case NDISC_ROUTER_SOLICITATION: |
292 | case NDISC_ROUTER_ADVERTISEMENT: |
293 | case NDISC_NEIGHBOUR_SOLICITATION: |
294 | case NDISC_NEIGHBOUR_ADVERTISEMENT: |
295 | case NDISC_REDIRECT: |
296 | /* For reaction involving unicast neighbor discovery |
297 | * message destined to the proxied address, pass it to |
298 | * input function. |
299 | */ |
300 | return 1; |
301 | default: |
302 | break; |
303 | } |
304 | } |
305 | |
306 | /* |
307 | * The proxying router can't forward traffic sent to a link-local |
308 | * address, so signal the sender and discard the packet. This |
309 | * behavior is clarified by the MIPv6 specification. |
310 | */ |
311 | if (ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) { |
312 | dst_link_failure(skb); |
313 | return -1; |
314 | } |
315 | |
316 | return 0; |
317 | } |
318 | |
319 | static inline int ip6_forward_finish(struct sk_buff *skb) |
320 | { |
321 | return dst_output(skb); |
322 | } |
323 | |
324 | static unsigned int ip6_dst_mtu_forward(const struct dst_entry *dst) |
325 | { |
326 | unsigned int mtu; |
327 | struct inet6_dev *idev; |
328 | |
329 | if (dst_metric_locked(dst, RTAX_MTU)) { |
330 | mtu = dst_metric_raw(dst, RTAX_MTU); |
331 | if (mtu) |
332 | return mtu; |
333 | } |
334 | |
335 | mtu = IPV6_MIN_MTU; |
336 | rcu_read_lock(); |
337 | idev = __in6_dev_get(dst->dev); |
338 | if (idev) |
339 | mtu = idev->cnf.mtu6; |
340 | rcu_read_unlock(); |
341 | |
342 | return mtu; |
343 | } |
344 | |
345 | static bool ip6_pkt_too_big(const struct sk_buff *skb, unsigned int mtu) |
346 | { |
347 | if (skb->len <= mtu) |
348 | return false; |
349 | |
350 | /* ipv6 conntrack defrag sets max_frag_size + local_df */ |
351 | if (IP6CB(skb)->frag_max_size && IP6CB(skb)->frag_max_size > mtu) |
352 | return true; |
353 | |
354 | if (skb->local_df) |
355 | return false; |
356 | |
357 | if (skb_is_gso(skb) && skb_gso_network_seglen(skb) <= mtu) |
358 | return false; |
359 | |
360 | return true; |
361 | } |
362 | |
363 | int ip6_forward(struct sk_buff *skb) |
364 | { |
365 | struct dst_entry *dst = skb_dst(skb); |
366 | struct ipv6hdr *hdr = ipv6_hdr(skb); |
367 | struct inet6_skb_parm *opt = IP6CB(skb); |
368 | struct net *net = dev_net(dst->dev); |
369 | u32 mtu; |
370 | |
371 | if (net->ipv6.devconf_all->forwarding == 0) |
372 | goto error; |
373 | |
374 | if (skb->pkt_type != PACKET_HOST) |
375 | goto drop; |
376 | |
377 | if (skb_warn_if_lro(skb)) |
378 | goto drop; |
379 | |
380 | if (!xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) { |
381 | IP6_INC_STATS_BH(net, ip6_dst_idev(dst), |
382 | IPSTATS_MIB_INDISCARDS); |
383 | goto drop; |
384 | } |
385 | |
386 | skb_forward_csum(skb); |
387 | |
388 | /* |
389 | * We DO NOT make any processing on |
390 | * RA packets, pushing them to user level AS IS |
391 | * without ane WARRANTY that application will be able |
392 | * to interpret them. The reason is that we |
393 | * cannot make anything clever here. |
394 | * |
395 | * We are not end-node, so that if packet contains |
396 | * AH/ESP, we cannot make anything. |
397 | * Defragmentation also would be mistake, RA packets |
398 | * cannot be fragmented, because there is no warranty |
399 | * that different fragments will go along one path. --ANK |
400 | */ |
401 | if (unlikely(opt->flags & IP6SKB_ROUTERALERT)) { |
402 | if (ip6_call_ra_chain(skb, ntohs(opt->ra))) |
403 | return 0; |
404 | } |
405 | |
406 | /* |
407 | * check and decrement ttl |
408 | */ |
409 | if (hdr->hop_limit <= 1) { |
410 | /* Force OUTPUT device used as source address */ |
411 | skb->dev = dst->dev; |
412 | icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 0); |
413 | IP6_INC_STATS_BH(net, ip6_dst_idev(dst), |
414 | IPSTATS_MIB_INHDRERRORS); |
415 | |
416 | kfree_skb(skb); |
417 | return -ETIMEDOUT; |
418 | } |
419 | |
420 | /* XXX: idev->cnf.proxy_ndp? */ |
421 | if (net->ipv6.devconf_all->proxy_ndp && |
422 | pneigh_lookup(&nd_tbl, net, &hdr->daddr, skb->dev, 0)) { |
423 | int proxied = ip6_forward_proxy_check(skb); |
424 | if (proxied > 0) |
425 | return ip6_input(skb); |
426 | else if (proxied < 0) { |
427 | IP6_INC_STATS_BH(net, ip6_dst_idev(dst), |
428 | IPSTATS_MIB_INDISCARDS); |
429 | goto drop; |
430 | } |
431 | } |
432 | |
433 | if (!xfrm6_route_forward(skb)) { |
434 | IP6_INC_STATS_BH(net, ip6_dst_idev(dst), |
435 | IPSTATS_MIB_INDISCARDS); |
436 | goto drop; |
437 | } |
438 | dst = skb_dst(skb); |
439 | |
440 | /* IPv6 specs say nothing about it, but it is clear that we cannot |
441 | send redirects to source routed frames. |
442 | We don't send redirects to frames decapsulated from IPsec. |
443 | */ |
444 | if (skb->dev == dst->dev && opt->srcrt == 0 && !skb_sec_path(skb)) { |
445 | struct in6_addr *target = NULL; |
446 | struct inet_peer *peer; |
447 | struct rt6_info *rt; |
448 | |
449 | /* |
450 | * incoming and outgoing devices are the same |
451 | * send a redirect. |
452 | */ |
453 | |
454 | rt = (struct rt6_info *) dst; |
455 | if (rt->rt6i_flags & RTF_GATEWAY) |
456 | target = &rt->rt6i_gateway; |
457 | else |
458 | target = &hdr->daddr; |
459 | |
460 | peer = inet_getpeer_v6(net->ipv6.peers, &rt->rt6i_dst.addr, 1); |
461 | |
462 | /* Limit redirects both by destination (here) |
463 | and by source (inside ndisc_send_redirect) |
464 | */ |
465 | if (inet_peer_xrlim_allow(peer, 1*HZ)) |
466 | ndisc_send_redirect(skb, target); |
467 | if (peer) |
468 | inet_putpeer(peer); |
469 | } else { |
470 | int addrtype = ipv6_addr_type(&hdr->saddr); |
471 | |
472 | /* This check is security critical. */ |
473 | if (addrtype == IPV6_ADDR_ANY || |
474 | addrtype & (IPV6_ADDR_MULTICAST | IPV6_ADDR_LOOPBACK)) |
475 | goto error; |
476 | if (addrtype & IPV6_ADDR_LINKLOCAL) { |
477 | icmpv6_send(skb, ICMPV6_DEST_UNREACH, |
478 | ICMPV6_NOT_NEIGHBOUR, 0); |
479 | goto error; |
480 | } |
481 | } |
482 | |
483 | mtu = ip6_dst_mtu_forward(dst); |
484 | if (mtu < IPV6_MIN_MTU) |
485 | mtu = IPV6_MIN_MTU; |
486 | |
487 | if (ip6_pkt_too_big(skb, mtu)) { |
488 | /* Again, force OUTPUT device used as source address */ |
489 | skb->dev = dst->dev; |
490 | icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); |
491 | IP6_INC_STATS_BH(net, ip6_dst_idev(dst), |
492 | IPSTATS_MIB_INTOOBIGERRORS); |
493 | IP6_INC_STATS_BH(net, ip6_dst_idev(dst), |
494 | IPSTATS_MIB_FRAGFAILS); |
495 | kfree_skb(skb); |
496 | return -EMSGSIZE; |
497 | } |
498 | |
499 | if (skb_cow(skb, dst->dev->hard_header_len)) { |
500 | IP6_INC_STATS_BH(net, ip6_dst_idev(dst), |
501 | IPSTATS_MIB_OUTDISCARDS); |
502 | goto drop; |
503 | } |
504 | |
505 | hdr = ipv6_hdr(skb); |
506 | |
507 | /* Mangling hops number delayed to point after skb COW */ |
508 | |
509 | hdr->hop_limit--; |
510 | |
511 | IP6_INC_STATS_BH(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTFORWDATAGRAMS); |
512 | IP6_ADD_STATS_BH(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTOCTETS, skb->len); |
513 | return NF_HOOK(NFPROTO_IPV6, NF_INET_FORWARD, skb, skb->dev, dst->dev, |
514 | ip6_forward_finish); |
515 | |
516 | error: |
517 | IP6_INC_STATS_BH(net, ip6_dst_idev(dst), IPSTATS_MIB_INADDRERRORS); |
518 | drop: |
519 | kfree_skb(skb); |
520 | return -EINVAL; |
521 | } |
522 | |
523 | static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from) |
524 | { |
525 | to->pkt_type = from->pkt_type; |
526 | to->priority = from->priority; |
527 | to->protocol = from->protocol; |
528 | skb_dst_drop(to); |
529 | skb_dst_set(to, dst_clone(skb_dst(from))); |
530 | to->dev = from->dev; |
531 | to->mark = from->mark; |
532 | |
533 | #ifdef CONFIG_NET_SCHED |
534 | to->tc_index = from->tc_index; |
535 | #endif |
536 | nf_copy(to, from); |
537 | skb_copy_secmark(to, from); |
538 | } |
539 | |
540 | int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *)) |
541 | { |
542 | struct sk_buff *frag; |
543 | struct rt6_info *rt = (struct rt6_info*)skb_dst(skb); |
544 | struct ipv6_pinfo *np = skb->sk ? inet6_sk(skb->sk) : NULL; |
545 | struct ipv6hdr *tmp_hdr; |
546 | struct frag_hdr *fh; |
547 | unsigned int mtu, hlen, left, len; |
548 | int hroom, troom; |
549 | __be32 frag_id = 0; |
550 | int ptr, offset = 0, err=0; |
551 | u8 *prevhdr, nexthdr = 0; |
552 | struct net *net = dev_net(skb_dst(skb)->dev); |
553 | |
554 | hlen = ip6_find_1stfragopt(skb, &prevhdr); |
555 | nexthdr = *prevhdr; |
556 | |
557 | mtu = ip6_skb_dst_mtu(skb); |
558 | |
559 | /* We must not fragment if the socket is set to force MTU discovery |
560 | * or if the skb it not generated by a local socket. |
561 | */ |
562 | if (unlikely(!skb->local_df && skb->len > mtu) || |
563 | (IP6CB(skb)->frag_max_size && |
564 | IP6CB(skb)->frag_max_size > mtu)) { |
565 | if (skb->sk && dst_allfrag(skb_dst(skb))) |
566 | sk_nocaps_add(skb->sk, NETIF_F_GSO_MASK); |
567 | |
568 | skb->dev = skb_dst(skb)->dev; |
569 | icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); |
570 | IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), |
571 | IPSTATS_MIB_FRAGFAILS); |
572 | kfree_skb(skb); |
573 | return -EMSGSIZE; |
574 | } |
575 | |
576 | if (np && np->frag_size < mtu) { |
577 | if (np->frag_size) |
578 | mtu = np->frag_size; |
579 | } |
580 | mtu -= hlen + sizeof(struct frag_hdr); |
581 | |
582 | if (skb_has_frag_list(skb)) { |
583 | int first_len = skb_pagelen(skb); |
584 | struct sk_buff *frag2; |
585 | |
586 | if (first_len - hlen > mtu || |
587 | ((first_len - hlen) & 7) || |
588 | skb_cloned(skb)) |
589 | goto slow_path; |
590 | |
591 | skb_walk_frags(skb, frag) { |
592 | /* Correct geometry. */ |
593 | if (frag->len > mtu || |
594 | ((frag->len & 7) && frag->next) || |
595 | skb_headroom(frag) < hlen) |
596 | goto slow_path_clean; |
597 | |
598 | /* Partially cloned skb? */ |
599 | if (skb_shared(frag)) |
600 | goto slow_path_clean; |
601 | |
602 | BUG_ON(frag->sk); |
603 | if (skb->sk) { |
604 | frag->sk = skb->sk; |
605 | frag->destructor = sock_wfree; |
606 | } |
607 | skb->truesize -= frag->truesize; |
608 | } |
609 | |
610 | err = 0; |
611 | offset = 0; |
612 | frag = skb_shinfo(skb)->frag_list; |
613 | skb_frag_list_init(skb); |
614 | /* BUILD HEADER */ |
615 | |
616 | *prevhdr = NEXTHDR_FRAGMENT; |
617 | tmp_hdr = kmemdup(skb_network_header(skb), hlen, GFP_ATOMIC); |
618 | if (!tmp_hdr) { |
619 | IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), |
620 | IPSTATS_MIB_FRAGFAILS); |
621 | return -ENOMEM; |
622 | } |
623 | |
624 | __skb_pull(skb, hlen); |
625 | fh = (struct frag_hdr*)__skb_push(skb, sizeof(struct frag_hdr)); |
626 | __skb_push(skb, hlen); |
627 | skb_reset_network_header(skb); |
628 | memcpy(skb_network_header(skb), tmp_hdr, hlen); |
629 | |
630 | ipv6_select_ident(fh, rt); |
631 | fh->nexthdr = nexthdr; |
632 | fh->reserved = 0; |
633 | fh->frag_off = htons(IP6_MF); |
634 | frag_id = fh->identification; |
635 | |
636 | first_len = skb_pagelen(skb); |
637 | skb->data_len = first_len - skb_headlen(skb); |
638 | skb->len = first_len; |
639 | ipv6_hdr(skb)->payload_len = htons(first_len - |
640 | sizeof(struct ipv6hdr)); |
641 | |
642 | dst_hold(&rt->dst); |
643 | |
644 | for (;;) { |
645 | /* Prepare header of the next frame, |
646 | * before previous one went down. */ |
647 | if (frag) { |
648 | frag->ip_summed = CHECKSUM_NONE; |
649 | skb_reset_transport_header(frag); |
650 | fh = (struct frag_hdr*)__skb_push(frag, sizeof(struct frag_hdr)); |
651 | __skb_push(frag, hlen); |
652 | skb_reset_network_header(frag); |
653 | memcpy(skb_network_header(frag), tmp_hdr, |
654 | hlen); |
655 | offset += skb->len - hlen - sizeof(struct frag_hdr); |
656 | fh->nexthdr = nexthdr; |
657 | fh->reserved = 0; |
658 | fh->frag_off = htons(offset); |
659 | if (frag->next != NULL) |
660 | fh->frag_off |= htons(IP6_MF); |
661 | fh->identification = frag_id; |
662 | ipv6_hdr(frag)->payload_len = |
663 | htons(frag->len - |
664 | sizeof(struct ipv6hdr)); |
665 | ip6_copy_metadata(frag, skb); |
666 | } |
667 | |
668 | err = output(skb); |
669 | if(!err) |
670 | IP6_INC_STATS(net, ip6_dst_idev(&rt->dst), |
671 | IPSTATS_MIB_FRAGCREATES); |
672 | |
673 | if (err || !frag) |
674 | break; |
675 | |
676 | skb = frag; |
677 | frag = skb->next; |
678 | skb->next = NULL; |
679 | } |
680 | |
681 | kfree(tmp_hdr); |
682 | |
683 | if (err == 0) { |
684 | IP6_INC_STATS(net, ip6_dst_idev(&rt->dst), |
685 | IPSTATS_MIB_FRAGOKS); |
686 | ip6_rt_put(rt); |
687 | return 0; |
688 | } |
689 | |
690 | while (frag) { |
691 | skb = frag->next; |
692 | kfree_skb(frag); |
693 | frag = skb; |
694 | } |
695 | |
696 | IP6_INC_STATS(net, ip6_dst_idev(&rt->dst), |
697 | IPSTATS_MIB_FRAGFAILS); |
698 | ip6_rt_put(rt); |
699 | return err; |
700 | |
701 | slow_path_clean: |
702 | skb_walk_frags(skb, frag2) { |
703 | if (frag2 == frag) |
704 | break; |
705 | frag2->sk = NULL; |
706 | frag2->destructor = NULL; |
707 | skb->truesize += frag2->truesize; |
708 | } |
709 | } |
710 | |
711 | slow_path: |
712 | if ((skb->ip_summed == CHECKSUM_PARTIAL) && |
713 | skb_checksum_help(skb)) |
714 | goto fail; |
715 | |
716 | left = skb->len - hlen; /* Space per frame */ |
717 | ptr = hlen; /* Where to start from */ |
718 | |
719 | /* |
720 | * Fragment the datagram. |
721 | */ |
722 | |
723 | *prevhdr = NEXTHDR_FRAGMENT; |
724 | hroom = LL_RESERVED_SPACE(rt->dst.dev); |
725 | troom = rt->dst.dev->needed_tailroom; |
726 | |
727 | /* |
728 | * Keep copying data until we run out. |
729 | */ |
730 | while(left > 0) { |
731 | len = left; |
732 | /* IF: it doesn't fit, use 'mtu' - the data space left */ |
733 | if (len > mtu) |
734 | len = mtu; |
735 | /* IF: we are not sending up to and including the packet end |
736 | then align the next start on an eight byte boundary */ |
737 | if (len < left) { |
738 | len &= ~7; |
739 | } |
740 | /* |
741 | * Allocate buffer. |
742 | */ |
743 | |
744 | if ((frag = alloc_skb(len + hlen + sizeof(struct frag_hdr) + |
745 | hroom + troom, GFP_ATOMIC)) == NULL) { |
746 | NETDEBUG(KERN_INFO "IPv6: frag: no memory for new fragment!\n"); |
747 | IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), |
748 | IPSTATS_MIB_FRAGFAILS); |
749 | err = -ENOMEM; |
750 | goto fail; |
751 | } |
752 | |
753 | /* |
754 | * Set up data on packet |
755 | */ |
756 | |
757 | ip6_copy_metadata(frag, skb); |
758 | skb_reserve(frag, hroom); |
759 | skb_put(frag, len + hlen + sizeof(struct frag_hdr)); |
760 | skb_reset_network_header(frag); |
761 | fh = (struct frag_hdr *)(skb_network_header(frag) + hlen); |
762 | frag->transport_header = (frag->network_header + hlen + |
763 | sizeof(struct frag_hdr)); |
764 | |
765 | /* |
766 | * Charge the memory for the fragment to any owner |
767 | * it might possess |
768 | */ |
769 | if (skb->sk) |
770 | skb_set_owner_w(frag, skb->sk); |
771 | |
772 | /* |
773 | * Copy the packet header into the new buffer. |
774 | */ |
775 | skb_copy_from_linear_data(skb, skb_network_header(frag), hlen); |
776 | |
777 | /* |
778 | * Build fragment header. |
779 | */ |
780 | fh->nexthdr = nexthdr; |
781 | fh->reserved = 0; |
782 | if (!frag_id) { |
783 | ipv6_select_ident(fh, rt); |
784 | frag_id = fh->identification; |
785 | } else |
786 | fh->identification = frag_id; |
787 | |
788 | /* |
789 | * Copy a block of the IP datagram. |
790 | */ |
791 | if (skb_copy_bits(skb, ptr, skb_transport_header(frag), len)) |
792 | BUG(); |
793 | left -= len; |
794 | |
795 | fh->frag_off = htons(offset); |
796 | if (left > 0) |
797 | fh->frag_off |= htons(IP6_MF); |
798 | ipv6_hdr(frag)->payload_len = htons(frag->len - |
799 | sizeof(struct ipv6hdr)); |
800 | |
801 | ptr += len; |
802 | offset += len; |
803 | |
804 | /* |
805 | * Put this fragment into the sending queue. |
806 | */ |
807 | err = output(frag); |
808 | if (err) |
809 | goto fail; |
810 | |
811 | IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), |
812 | IPSTATS_MIB_FRAGCREATES); |
813 | } |
814 | IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), |
815 | IPSTATS_MIB_FRAGOKS); |
816 | consume_skb(skb); |
817 | return err; |
818 | |
819 | fail: |
820 | IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), |
821 | IPSTATS_MIB_FRAGFAILS); |
822 | kfree_skb(skb); |
823 | return err; |
824 | } |
825 | |
826 | static inline int ip6_rt_check(const struct rt6key *rt_key, |
827 | const struct in6_addr *fl_addr, |
828 | const struct in6_addr *addr_cache) |
829 | { |
830 | return (rt_key->plen != 128 || !ipv6_addr_equal(fl_addr, &rt_key->addr)) && |
831 | (addr_cache == NULL || !ipv6_addr_equal(fl_addr, addr_cache)); |
832 | } |
833 | |
834 | static struct dst_entry *ip6_sk_dst_check(struct sock *sk, |
835 | struct dst_entry *dst, |
836 | const struct flowi6 *fl6) |
837 | { |
838 | struct ipv6_pinfo *np = inet6_sk(sk); |
839 | struct rt6_info *rt; |
840 | |
841 | if (!dst) |
842 | goto out; |
843 | |
844 | if (dst->ops->family != AF_INET6) { |
845 | dst_release(dst); |
846 | return NULL; |
847 | } |
848 | |
849 | rt = (struct rt6_info *)dst; |
850 | /* Yes, checking route validity in not connected |
851 | * case is not very simple. Take into account, |
852 | * that we do not support routing by source, TOS, |
853 | * and MSG_DONTROUTE --ANK (980726) |
854 | * |
855 | * 1. ip6_rt_check(): If route was host route, |
856 | * check that cached destination is current. |
857 | * If it is network route, we still may |
858 | * check its validity using saved pointer |
859 | * to the last used address: daddr_cache. |
860 | * We do not want to save whole address now, |
861 | * (because main consumer of this service |
862 | * is tcp, which has not this problem), |
863 | * so that the last trick works only on connected |
864 | * sockets. |
865 | * 2. oif also should be the same. |
866 | */ |
867 | if (ip6_rt_check(&rt->rt6i_dst, &fl6->daddr, np->daddr_cache) || |
868 | #ifdef CONFIG_IPV6_SUBTREES |
869 | ip6_rt_check(&rt->rt6i_src, &fl6->saddr, np->saddr_cache) || |
870 | #endif |
871 | (fl6->flowi6_oif && fl6->flowi6_oif != dst->dev->ifindex)) { |
872 | dst_release(dst); |
873 | dst = NULL; |
874 | } |
875 | |
876 | out: |
877 | return dst; |
878 | } |
879 | |
880 | static int ip6_dst_lookup_tail(struct sock *sk, |
881 | struct dst_entry **dst, struct flowi6 *fl6) |
882 | { |
883 | struct net *net = sock_net(sk); |
884 | #ifdef CONFIG_IPV6_OPTIMISTIC_DAD |
885 | struct neighbour *n; |
886 | struct rt6_info *rt; |
887 | #endif |
888 | int err; |
889 | |
890 | if (*dst == NULL) |
891 | *dst = ip6_route_output(net, sk, fl6); |
892 | |
893 | if ((err = (*dst)->error)) |
894 | goto out_err_release; |
895 | |
896 | if (ipv6_addr_any(&fl6->saddr)) { |
897 | struct rt6_info *rt = (struct rt6_info *) *dst; |
898 | err = ip6_route_get_saddr(net, rt, &fl6->daddr, |
899 | sk ? inet6_sk(sk)->srcprefs : 0, |
900 | &fl6->saddr); |
901 | if (err) |
902 | goto out_err_release; |
903 | } |
904 | |
905 | #ifdef CONFIG_IPV6_OPTIMISTIC_DAD |
906 | /* |
907 | * Here if the dst entry we've looked up |
908 | * has a neighbour entry that is in the INCOMPLETE |
909 | * state and the src address from the flow is |
910 | * marked as OPTIMISTIC, we release the found |
911 | * dst entry and replace it instead with the |
912 | * dst entry of the nexthop router |
913 | */ |
914 | rt = (struct rt6_info *) *dst; |
915 | rcu_read_lock_bh(); |
916 | n = __ipv6_neigh_lookup_noref(rt->dst.dev, rt6_nexthop(rt)); |
917 | err = n && !(n->nud_state & NUD_VALID) ? -EINVAL : 0; |
918 | rcu_read_unlock_bh(); |
919 | |
920 | if (err) { |
921 | struct inet6_ifaddr *ifp; |
922 | struct flowi6 fl_gw6; |
923 | int redirect; |
924 | |
925 | ifp = ipv6_get_ifaddr(net, &fl6->saddr, |
926 | (*dst)->dev, 1); |
927 | |
928 | redirect = (ifp && ifp->flags & IFA_F_OPTIMISTIC); |
929 | if (ifp) |
930 | in6_ifa_put(ifp); |
931 | |
932 | if (redirect) { |
933 | /* |
934 | * We need to get the dst entry for the |
935 | * default router instead |
936 | */ |
937 | dst_release(*dst); |
938 | memcpy(&fl_gw6, fl6, sizeof(struct flowi6)); |
939 | memset(&fl_gw6.daddr, 0, sizeof(struct in6_addr)); |
940 | *dst = ip6_route_output(net, sk, &fl_gw6); |
941 | if ((err = (*dst)->error)) |
942 | goto out_err_release; |
943 | } |
944 | } |
945 | #endif |
946 | |
947 | return 0; |
948 | |
949 | out_err_release: |
950 | if (err == -ENETUNREACH) |
951 | IP6_INC_STATS(net, NULL, IPSTATS_MIB_OUTNOROUTES); |
952 | dst_release(*dst); |
953 | *dst = NULL; |
954 | return err; |
955 | } |
956 | |
957 | /** |
958 | * ip6_dst_lookup - perform route lookup on flow |
959 | * @sk: socket which provides route info |
960 | * @dst: pointer to dst_entry * for result |
961 | * @fl6: flow to lookup |
962 | * |
963 | * This function performs a route lookup on the given flow. |
964 | * |
965 | * It returns zero on success, or a standard errno code on error. |
966 | */ |
967 | int ip6_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi6 *fl6) |
968 | { |
969 | *dst = NULL; |
970 | return ip6_dst_lookup_tail(sk, dst, fl6); |
971 | } |
972 | EXPORT_SYMBOL_GPL(ip6_dst_lookup); |
973 | |
974 | /** |
975 | * ip6_dst_lookup_flow - perform route lookup on flow with ipsec |
976 | * @sk: socket which provides route info |
977 | * @fl6: flow to lookup |
978 | * @final_dst: final destination address for ipsec lookup |
979 | * |
980 | * This function performs a route lookup on the given flow. |
981 | * |
982 | * It returns a valid dst pointer on success, or a pointer encoded |
983 | * error code. |
984 | */ |
985 | struct dst_entry *ip6_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6, |
986 | const struct in6_addr *final_dst) |
987 | { |
988 | struct dst_entry *dst = NULL; |
989 | int err; |
990 | |
991 | err = ip6_dst_lookup_tail(sk, &dst, fl6); |
992 | if (err) |
993 | return ERR_PTR(err); |
994 | if (final_dst) |
995 | fl6->daddr = *final_dst; |
996 | |
997 | return xfrm_lookup(sock_net(sk), dst, flowi6_to_flowi(fl6), sk, 0); |
998 | } |
999 | EXPORT_SYMBOL_GPL(ip6_dst_lookup_flow); |
1000 | |
1001 | /** |
1002 | * ip6_sk_dst_lookup_flow - perform socket cached route lookup on flow |
1003 | * @sk: socket which provides the dst cache and route info |
1004 | * @fl6: flow to lookup |
1005 | * @final_dst: final destination address for ipsec lookup |
1006 | * |
1007 | * This function performs a route lookup on the given flow with the |
1008 | * possibility of using the cached route in the socket if it is valid. |
1009 | * It will take the socket dst lock when operating on the dst cache. |
1010 | * As a result, this function can only be used in process context. |
1011 | * |
1012 | * It returns a valid dst pointer on success, or a pointer encoded |
1013 | * error code. |
1014 | */ |
1015 | struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6, |
1016 | const struct in6_addr *final_dst) |
1017 | { |
1018 | struct dst_entry *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie); |
1019 | int err; |
1020 | |
1021 | dst = ip6_sk_dst_check(sk, dst, fl6); |
1022 | |
1023 | err = ip6_dst_lookup_tail(sk, &dst, fl6); |
1024 | if (err) |
1025 | return ERR_PTR(err); |
1026 | if (final_dst) |
1027 | fl6->daddr = *final_dst; |
1028 | |
1029 | return xfrm_lookup(sock_net(sk), dst, flowi6_to_flowi(fl6), sk, 0); |
1030 | } |
1031 | EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup_flow); |
1032 | |
1033 | static inline int ip6_ufo_append_data(struct sock *sk, |
1034 | int getfrag(void *from, char *to, int offset, int len, |
1035 | int odd, struct sk_buff *skb), |
1036 | void *from, int length, int hh_len, int fragheaderlen, |
1037 | int transhdrlen, int mtu,unsigned int flags, |
1038 | struct rt6_info *rt) |
1039 | |
1040 | { |
1041 | struct sk_buff *skb; |
1042 | struct frag_hdr fhdr; |
1043 | int err; |
1044 | |
1045 | /* There is support for UDP large send offload by network |
1046 | * device, so create one single skb packet containing complete |
1047 | * udp datagram |
1048 | */ |
1049 | if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) { |
1050 | skb = sock_alloc_send_skb(sk, |
1051 | hh_len + fragheaderlen + transhdrlen + 20, |
1052 | (flags & MSG_DONTWAIT), &err); |
1053 | if (skb == NULL) |
1054 | return err; |
1055 | |
1056 | /* reserve space for Hardware header */ |
1057 | skb_reserve(skb, hh_len); |
1058 | |
1059 | /* create space for UDP/IP header */ |
1060 | skb_put(skb,fragheaderlen + transhdrlen); |
1061 | |
1062 | /* initialize network header pointer */ |
1063 | skb_reset_network_header(skb); |
1064 | |
1065 | /* initialize protocol header pointer */ |
1066 | skb->transport_header = skb->network_header + fragheaderlen; |
1067 | |
1068 | skb->protocol = htons(ETH_P_IPV6); |
1069 | skb->csum = 0; |
1070 | |
1071 | __skb_queue_tail(&sk->sk_write_queue, skb); |
1072 | } else if (skb_is_gso(skb)) { |
1073 | goto append; |
1074 | } |
1075 | |
1076 | skb->ip_summed = CHECKSUM_PARTIAL; |
1077 | /* Specify the length of each IPv6 datagram fragment. |
1078 | * It has to be a multiple of 8. |
1079 | */ |
1080 | skb_shinfo(skb)->gso_size = (mtu - fragheaderlen - |
1081 | sizeof(struct frag_hdr)) & ~7; |
1082 | skb_shinfo(skb)->gso_type = SKB_GSO_UDP; |
1083 | ipv6_select_ident(&fhdr, rt); |
1084 | skb_shinfo(skb)->ip6_frag_id = fhdr.identification; |
1085 | |
1086 | append: |
1087 | return skb_append_datato_frags(sk, skb, getfrag, from, |
1088 | (length - transhdrlen)); |
1089 | } |
1090 | |
1091 | static inline struct ipv6_opt_hdr *ip6_opt_dup(struct ipv6_opt_hdr *src, |
1092 | gfp_t gfp) |
1093 | { |
1094 | return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL; |
1095 | } |
1096 | |
1097 | static inline struct ipv6_rt_hdr *ip6_rthdr_dup(struct ipv6_rt_hdr *src, |
1098 | gfp_t gfp) |
1099 | { |
1100 | return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL; |
1101 | } |
1102 | |
1103 | static void ip6_append_data_mtu(unsigned int *mtu, |
1104 | int *maxfraglen, |
1105 | unsigned int fragheaderlen, |
1106 | struct sk_buff *skb, |
1107 | struct rt6_info *rt, |
1108 | unsigned int orig_mtu) |
1109 | { |
1110 | if (!(rt->dst.flags & DST_XFRM_TUNNEL)) { |
1111 | if (skb == NULL) { |
1112 | /* first fragment, reserve header_len */ |
1113 | *mtu = orig_mtu - rt->dst.header_len; |
1114 | |
1115 | } else { |
1116 | /* |
1117 | * this fragment is not first, the headers |
1118 | * space is regarded as data space. |
1119 | */ |
1120 | *mtu = orig_mtu; |
1121 | } |
1122 | *maxfraglen = ((*mtu - fragheaderlen) & ~7) |
1123 | + fragheaderlen - sizeof(struct frag_hdr); |
1124 | } |
1125 | } |
1126 | |
1127 | int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to, |
1128 | int offset, int len, int odd, struct sk_buff *skb), |
1129 | void *from, int length, int transhdrlen, |
1130 | int hlimit, int tclass, struct ipv6_txoptions *opt, struct flowi6 *fl6, |
1131 | struct rt6_info *rt, unsigned int flags, int dontfrag) |
1132 | { |
1133 | struct inet_sock *inet = inet_sk(sk); |
1134 | struct ipv6_pinfo *np = inet6_sk(sk); |
1135 | struct inet_cork *cork; |
1136 | struct sk_buff *skb, *skb_prev = NULL; |
1137 | unsigned int maxfraglen, fragheaderlen, mtu, orig_mtu; |
1138 | int exthdrlen; |
1139 | int dst_exthdrlen; |
1140 | int hh_len; |
1141 | int copy; |
1142 | int err; |
1143 | int offset = 0; |
1144 | __u8 tx_flags = 0; |
1145 | |
1146 | if (flags&MSG_PROBE) |
1147 | return 0; |
1148 | cork = &inet->cork.base; |
1149 | if (skb_queue_empty(&sk->sk_write_queue)) { |
1150 | /* |
1151 | * setup for corking |
1152 | */ |
1153 | if (opt) { |
1154 | if (WARN_ON(np->cork.opt)) |
1155 | return -EINVAL; |
1156 | |
1157 | np->cork.opt = kzalloc(opt->tot_len, sk->sk_allocation); |
1158 | if (unlikely(np->cork.opt == NULL)) |
1159 | return -ENOBUFS; |
1160 | |
1161 | np->cork.opt->tot_len = opt->tot_len; |
1162 | np->cork.opt->opt_flen = opt->opt_flen; |
1163 | np->cork.opt->opt_nflen = opt->opt_nflen; |
1164 | |
1165 | np->cork.opt->dst0opt = ip6_opt_dup(opt->dst0opt, |
1166 | sk->sk_allocation); |
1167 | if (opt->dst0opt && !np->cork.opt->dst0opt) |
1168 | return -ENOBUFS; |
1169 | |
1170 | np->cork.opt->dst1opt = ip6_opt_dup(opt->dst1opt, |
1171 | sk->sk_allocation); |
1172 | if (opt->dst1opt && !np->cork.opt->dst1opt) |
1173 | return -ENOBUFS; |
1174 | |
1175 | np->cork.opt->hopopt = ip6_opt_dup(opt->hopopt, |
1176 | sk->sk_allocation); |
1177 | if (opt->hopopt && !np->cork.opt->hopopt) |
1178 | return -ENOBUFS; |
1179 | |
1180 | np->cork.opt->srcrt = ip6_rthdr_dup(opt->srcrt, |
1181 | sk->sk_allocation); |
1182 | if (opt->srcrt && !np->cork.opt->srcrt) |
1183 | return -ENOBUFS; |
1184 | |
1185 | /* need source address above miyazawa*/ |
1186 | } |
1187 | dst_hold(&rt->dst); |
1188 | cork->dst = &rt->dst; |
1189 | inet->cork.fl.u.ip6 = *fl6; |
1190 | np->cork.hop_limit = hlimit; |
1191 | np->cork.tclass = tclass; |
1192 | if (rt->dst.flags & DST_XFRM_TUNNEL) |
1193 | mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ? |
1194 | rt->dst.dev->mtu : dst_mtu(&rt->dst); |
1195 | else |
1196 | mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ? |
1197 | rt->dst.dev->mtu : dst_mtu(rt->dst.path); |
1198 | if (np->frag_size < mtu) { |
1199 | if (np->frag_size) |
1200 | mtu = np->frag_size; |
1201 | } |
1202 | cork->fragsize = mtu; |
1203 | if (dst_allfrag(rt->dst.path)) |
1204 | cork->flags |= IPCORK_ALLFRAG; |
1205 | cork->length = 0; |
1206 | exthdrlen = (opt ? opt->opt_flen : 0); |
1207 | length += exthdrlen; |
1208 | transhdrlen += exthdrlen; |
1209 | dst_exthdrlen = rt->dst.header_len - rt->rt6i_nfheader_len; |
1210 | } else { |
1211 | rt = (struct rt6_info *)cork->dst; |
1212 | fl6 = &inet->cork.fl.u.ip6; |
1213 | opt = np->cork.opt; |
1214 | transhdrlen = 0; |
1215 | exthdrlen = 0; |
1216 | dst_exthdrlen = 0; |
1217 | mtu = cork->fragsize; |
1218 | } |
1219 | orig_mtu = mtu; |
1220 | |
1221 | hh_len = LL_RESERVED_SPACE(rt->dst.dev); |
1222 | |
1223 | fragheaderlen = sizeof(struct ipv6hdr) + rt->rt6i_nfheader_len + |
1224 | (opt ? opt->opt_nflen : 0); |
1225 | maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - |
1226 | sizeof(struct frag_hdr); |
1227 | |
1228 | if (mtu <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN) { |
1229 | unsigned int maxnonfragsize, headersize; |
1230 | |
1231 | headersize = sizeof(struct ipv6hdr) + |
1232 | (opt ? opt->opt_flen + opt->opt_nflen : 0) + |
1233 | (dst_allfrag(&rt->dst) ? |
1234 | sizeof(struct frag_hdr) : 0) + |
1235 | rt->rt6i_nfheader_len; |
1236 | |
1237 | if (ip6_sk_local_df(sk)) |
1238 | maxnonfragsize = sizeof(struct ipv6hdr) + IPV6_MAXPLEN; |
1239 | else |
1240 | maxnonfragsize = mtu; |
1241 | |
1242 | /* dontfrag active */ |
1243 | if ((cork->length + length > mtu - headersize) && dontfrag && |
1244 | (sk->sk_protocol == IPPROTO_UDP || |
1245 | sk->sk_protocol == IPPROTO_RAW)) { |
1246 | ipv6_local_rxpmtu(sk, fl6, mtu - headersize + |
1247 | sizeof(struct ipv6hdr)); |
1248 | goto emsgsize; |
1249 | } |
1250 | |
1251 | if (cork->length + length > maxnonfragsize - headersize) { |
1252 | emsgsize: |
1253 | ipv6_local_error(sk, EMSGSIZE, fl6, |
1254 | mtu - headersize + |
1255 | sizeof(struct ipv6hdr)); |
1256 | return -EMSGSIZE; |
1257 | } |
1258 | } |
1259 | |
1260 | /* For UDP, check if TX timestamp is enabled */ |
1261 | if (sk->sk_type == SOCK_DGRAM) |
1262 | sock_tx_timestamp(sk, &tx_flags); |
1263 | |
1264 | /* |
1265 | * Let's try using as much space as possible. |
1266 | * Use MTU if total length of the message fits into the MTU. |
1267 | * Otherwise, we need to reserve fragment header and |
1268 | * fragment alignment (= 8-15 octects, in total). |
1269 | * |
1270 | * Note that we may need to "move" the data from the tail of |
1271 | * of the buffer to the new fragment when we split |
1272 | * the message. |
1273 | * |
1274 | * FIXME: It may be fragmented into multiple chunks |
1275 | * at once if non-fragmentable extension headers |
1276 | * are too large. |
1277 | * --yoshfuji |
1278 | */ |
1279 | |
1280 | skb = skb_peek_tail(&sk->sk_write_queue); |
1281 | cork->length += length; |
1282 | if (((length > mtu) || |
1283 | (skb && skb_is_gso(skb))) && |
1284 | (sk->sk_protocol == IPPROTO_UDP) && |
1285 | (rt->dst.dev->features & NETIF_F_UFO)) { |
1286 | err = ip6_ufo_append_data(sk, getfrag, from, length, |
1287 | hh_len, fragheaderlen, |
1288 | transhdrlen, mtu, flags, rt); |
1289 | if (err) |
1290 | goto error; |
1291 | return 0; |
1292 | } |
1293 | |
1294 | if (!skb) |
1295 | goto alloc_new_skb; |
1296 | |
1297 | while (length > 0) { |
1298 | /* Check if the remaining data fits into current packet. */ |
1299 | copy = (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len; |
1300 | if (copy < length) |
1301 | copy = maxfraglen - skb->len; |
1302 | |
1303 | if (copy <= 0) { |
1304 | char *data; |
1305 | unsigned int datalen; |
1306 | unsigned int fraglen; |
1307 | unsigned int fraggap; |
1308 | unsigned int alloclen; |
1309 | alloc_new_skb: |
1310 | /* There's no room in the current skb */ |
1311 | if (skb) |
1312 | fraggap = skb->len - maxfraglen; |
1313 | else |
1314 | fraggap = 0; |
1315 | /* update mtu and maxfraglen if necessary */ |
1316 | if (skb == NULL || skb_prev == NULL) |
1317 | ip6_append_data_mtu(&mtu, &maxfraglen, |
1318 | fragheaderlen, skb, rt, |
1319 | orig_mtu); |
1320 | |
1321 | skb_prev = skb; |
1322 | |
1323 | /* |
1324 | * If remaining data exceeds the mtu, |
1325 | * we know we need more fragment(s). |
1326 | */ |
1327 | datalen = length + fraggap; |
1328 | |
1329 | if (datalen > (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen) |
1330 | datalen = maxfraglen - fragheaderlen - rt->dst.trailer_len; |
1331 | if ((flags & MSG_MORE) && |
1332 | !(rt->dst.dev->features&NETIF_F_SG)) |
1333 | alloclen = mtu; |
1334 | else |
1335 | alloclen = datalen + fragheaderlen; |
1336 | |
1337 | alloclen += dst_exthdrlen; |
1338 | |
1339 | if (datalen != length + fraggap) { |
1340 | /* |
1341 | * this is not the last fragment, the trailer |
1342 | * space is regarded as data space. |
1343 | */ |
1344 | datalen += rt->dst.trailer_len; |
1345 | } |
1346 | |
1347 | alloclen += rt->dst.trailer_len; |
1348 | fraglen = datalen + fragheaderlen; |
1349 | |
1350 | /* |
1351 | * We just reserve space for fragment header. |
1352 | * Note: this may be overallocation if the message |
1353 | * (without MSG_MORE) fits into the MTU. |
1354 | */ |
1355 | alloclen += sizeof(struct frag_hdr); |
1356 | |
1357 | if (transhdrlen) { |
1358 | skb = sock_alloc_send_skb(sk, |
1359 | alloclen + hh_len, |
1360 | (flags & MSG_DONTWAIT), &err); |
1361 | } else { |
1362 | skb = NULL; |
1363 | if (atomic_read(&sk->sk_wmem_alloc) <= |
1364 | 2 * sk->sk_sndbuf) |
1365 | skb = sock_wmalloc(sk, |
1366 | alloclen + hh_len, 1, |
1367 | sk->sk_allocation); |
1368 | if (unlikely(skb == NULL)) |
1369 | err = -ENOBUFS; |
1370 | else { |
1371 | /* Only the initial fragment |
1372 | * is time stamped. |
1373 | */ |
1374 | tx_flags = 0; |
1375 | } |
1376 | } |
1377 | if (skb == NULL) |
1378 | goto error; |
1379 | /* |
1380 | * Fill in the control structures |
1381 | */ |
1382 | skb->protocol = htons(ETH_P_IPV6); |
1383 | skb->ip_summed = CHECKSUM_NONE; |
1384 | skb->csum = 0; |
1385 | /* reserve for fragmentation and ipsec header */ |
1386 | skb_reserve(skb, hh_len + sizeof(struct frag_hdr) + |
1387 | dst_exthdrlen); |
1388 | |
1389 | if (sk->sk_type == SOCK_DGRAM) |
1390 | skb_shinfo(skb)->tx_flags = tx_flags; |
1391 | |
1392 | /* |
1393 | * Find where to start putting bytes |
1394 | */ |
1395 | data = skb_put(skb, fraglen); |
1396 | skb_set_network_header(skb, exthdrlen); |
1397 | data += fragheaderlen; |
1398 | skb->transport_header = (skb->network_header + |
1399 | fragheaderlen); |
1400 | if (fraggap) { |
1401 | skb->csum = skb_copy_and_csum_bits( |
1402 | skb_prev, maxfraglen, |
1403 | data + transhdrlen, fraggap, 0); |
1404 | skb_prev->csum = csum_sub(skb_prev->csum, |
1405 | skb->csum); |
1406 | data += fraggap; |
1407 | pskb_trim_unique(skb_prev, maxfraglen); |
1408 | } |
1409 | copy = datalen - transhdrlen - fraggap; |
1410 | |
1411 | if (copy < 0) { |
1412 | err = -EINVAL; |
1413 | kfree_skb(skb); |
1414 | goto error; |
1415 | } else if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) { |
1416 | err = -EFAULT; |
1417 | kfree_skb(skb); |
1418 | goto error; |
1419 | } |
1420 | |
1421 | offset += copy; |
1422 | length -= datalen - fraggap; |
1423 | transhdrlen = 0; |
1424 | exthdrlen = 0; |
1425 | dst_exthdrlen = 0; |
1426 | |
1427 | /* |
1428 | * Put the packet on the pending queue |
1429 | */ |
1430 | __skb_queue_tail(&sk->sk_write_queue, skb); |
1431 | continue; |
1432 | } |
1433 | |
1434 | if (copy > length) |
1435 | copy = length; |
1436 | |
1437 | if (!(rt->dst.dev->features&NETIF_F_SG)) { |
1438 | unsigned int off; |
1439 | |
1440 | off = skb->len; |
1441 | if (getfrag(from, skb_put(skb, copy), |
1442 | offset, copy, off, skb) < 0) { |
1443 | __skb_trim(skb, off); |
1444 | err = -EFAULT; |
1445 | goto error; |
1446 | } |
1447 | } else { |
1448 | int i = skb_shinfo(skb)->nr_frags; |
1449 | struct page_frag *pfrag = sk_page_frag(sk); |
1450 | |
1451 | err = -ENOMEM; |
1452 | if (!sk_page_frag_refill(sk, pfrag)) |
1453 | goto error; |
1454 | |
1455 | if (!skb_can_coalesce(skb, i, pfrag->page, |
1456 | pfrag->offset)) { |
1457 | err = -EMSGSIZE; |
1458 | if (i == MAX_SKB_FRAGS) |
1459 | goto error; |
1460 | |
1461 | __skb_fill_page_desc(skb, i, pfrag->page, |
1462 | pfrag->offset, 0); |
1463 | skb_shinfo(skb)->nr_frags = ++i; |
1464 | get_page(pfrag->page); |
1465 | } |
1466 | copy = min_t(int, copy, pfrag->size - pfrag->offset); |
1467 | if (getfrag(from, |
1468 | page_address(pfrag->page) + pfrag->offset, |
1469 | offset, copy, skb->len, skb) < 0) |
1470 | goto error_efault; |
1471 | |
1472 | pfrag->offset += copy; |
1473 | skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); |
1474 | skb->len += copy; |
1475 | skb->data_len += copy; |
1476 | skb->truesize += copy; |
1477 | atomic_add(copy, &sk->sk_wmem_alloc); |
1478 | } |
1479 | offset += copy; |
1480 | length -= copy; |
1481 | } |
1482 | |
1483 | return 0; |
1484 | |
1485 | error_efault: |
1486 | err = -EFAULT; |
1487 | error: |
1488 | cork->length -= length; |
1489 | IP6_INC_STATS(sock_net(sk), rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS); |
1490 | return err; |
1491 | } |
1492 | EXPORT_SYMBOL_GPL(ip6_append_data); |
1493 | |
1494 | static void ip6_cork_release(struct inet_sock *inet, struct ipv6_pinfo *np) |
1495 | { |
1496 | if (np->cork.opt) { |
1497 | kfree(np->cork.opt->dst0opt); |
1498 | kfree(np->cork.opt->dst1opt); |
1499 | kfree(np->cork.opt->hopopt); |
1500 | kfree(np->cork.opt->srcrt); |
1501 | kfree(np->cork.opt); |
1502 | np->cork.opt = NULL; |
1503 | } |
1504 | |
1505 | if (inet->cork.base.dst) { |
1506 | dst_release(inet->cork.base.dst); |
1507 | inet->cork.base.dst = NULL; |
1508 | inet->cork.base.flags &= ~IPCORK_ALLFRAG; |
1509 | } |
1510 | memset(&inet->cork.fl, 0, sizeof(inet->cork.fl)); |
1511 | } |
1512 | |
1513 | int ip6_push_pending_frames(struct sock *sk) |
1514 | { |
1515 | struct sk_buff *skb, *tmp_skb; |
1516 | struct sk_buff **tail_skb; |
1517 | struct in6_addr final_dst_buf, *final_dst = &final_dst_buf; |
1518 | struct inet_sock *inet = inet_sk(sk); |
1519 | struct ipv6_pinfo *np = inet6_sk(sk); |
1520 | struct net *net = sock_net(sk); |
1521 | struct ipv6hdr *hdr; |
1522 | struct ipv6_txoptions *opt = np->cork.opt; |
1523 | struct rt6_info *rt = (struct rt6_info *)inet->cork.base.dst; |
1524 | struct flowi6 *fl6 = &inet->cork.fl.u.ip6; |
1525 | unsigned char proto = fl6->flowi6_proto; |
1526 | int err = 0; |
1527 | |
1528 | if ((skb = __skb_dequeue(&sk->sk_write_queue)) == NULL) |
1529 | goto out; |
1530 | tail_skb = &(skb_shinfo(skb)->frag_list); |
1531 | |
1532 | /* move skb->data to ip header from ext header */ |
1533 | if (skb->data < skb_network_header(skb)) |
1534 | __skb_pull(skb, skb_network_offset(skb)); |
1535 | while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) { |
1536 | __skb_pull(tmp_skb, skb_network_header_len(skb)); |
1537 | *tail_skb = tmp_skb; |
1538 | tail_skb = &(tmp_skb->next); |
1539 | skb->len += tmp_skb->len; |
1540 | skb->data_len += tmp_skb->len; |
1541 | skb->truesize += tmp_skb->truesize; |
1542 | tmp_skb->destructor = NULL; |
1543 | tmp_skb->sk = NULL; |
1544 | } |
1545 | |
1546 | /* Allow local fragmentation. */ |
1547 | skb->local_df = ip6_sk_local_df(sk); |
1548 | |
1549 | *final_dst = fl6->daddr; |
1550 | __skb_pull(skb, skb_network_header_len(skb)); |
1551 | if (opt && opt->opt_flen) |
1552 | ipv6_push_frag_opts(skb, opt, &proto); |
1553 | if (opt && opt->opt_nflen) |
1554 | ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst); |
1555 | |
1556 | skb_push(skb, sizeof(struct ipv6hdr)); |
1557 | skb_reset_network_header(skb); |
1558 | hdr = ipv6_hdr(skb); |
1559 | |
1560 | ip6_flow_hdr(hdr, np->cork.tclass, fl6->flowlabel); |
1561 | hdr->hop_limit = np->cork.hop_limit; |
1562 | hdr->nexthdr = proto; |
1563 | hdr->saddr = fl6->saddr; |
1564 | hdr->daddr = *final_dst; |
1565 | |
1566 | skb->priority = sk->sk_priority; |
1567 | skb->mark = sk->sk_mark; |
1568 | |
1569 | skb_dst_set(skb, dst_clone(&rt->dst)); |
1570 | IP6_UPD_PO_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUT, skb->len); |
1571 | if (proto == IPPROTO_ICMPV6) { |
1572 | struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); |
1573 | |
1574 | ICMP6MSGOUT_INC_STATS(net, idev, icmp6_hdr(skb)->icmp6_type); |
1575 | ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS); |
1576 | } |
1577 | |
1578 | err = ip6_local_out(skb); |
1579 | if (err) { |
1580 | if (err > 0) |
1581 | err = net_xmit_errno(err); |
1582 | if (err) |
1583 | goto error; |
1584 | } |
1585 | |
1586 | out: |
1587 | ip6_cork_release(inet, np); |
1588 | return err; |
1589 | error: |
1590 | IP6_INC_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS); |
1591 | goto out; |
1592 | } |
1593 | EXPORT_SYMBOL_GPL(ip6_push_pending_frames); |
1594 | |
1595 | void ip6_flush_pending_frames(struct sock *sk) |
1596 | { |
1597 | struct sk_buff *skb; |
1598 | |
1599 | while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) { |
1600 | if (skb_dst(skb)) |
1601 | IP6_INC_STATS(sock_net(sk), ip6_dst_idev(skb_dst(skb)), |
1602 | IPSTATS_MIB_OUTDISCARDS); |
1603 | kfree_skb(skb); |
1604 | } |
1605 | |
1606 | ip6_cork_release(inet_sk(sk), inet6_sk(sk)); |
1607 | } |
1608 | EXPORT_SYMBOL_GPL(ip6_flush_pending_frames); |
1609 |
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Tags:
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v2.6.34-rc5
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