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Commit | Line | Data |
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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 | ||
41 | #include <linux/netfilter.h> | |
42 | #include <linux/netfilter_ipv6.h> | |
43 | ||
44 | #include <net/sock.h> | |
45 | #include <net/snmp.h> | |
46 | ||
47 | #include <net/ipv6.h> | |
48 | #include <net/ndisc.h> | |
49 | #include <net/protocol.h> | |
50 | #include <net/ip6_route.h> | |
51 | #include <net/addrconf.h> | |
52 | #include <net/rawv6.h> | |
53 | #include <net/icmp.h> | |
54 | #include <net/xfrm.h> | |
55 | #include <net/checksum.h> | |
56 | #include <linux/mroute6.h> | |
57 | ||
58 | static int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *)); | |
59 | ||
60 | int __ip6_local_out(struct sk_buff *skb) | |
61 | { | |
62 | int len; | |
63 | ||
64 | len = skb->len - sizeof(struct ipv6hdr); | |
65 | if (len > IPV6_MAXPLEN) | |
66 | len = 0; | |
67 | ipv6_hdr(skb)->payload_len = htons(len); | |
68 | ||
69 | return nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, skb, NULL, | |
70 | skb_dst(skb)->dev, dst_output); | |
71 | } | |
72 | ||
73 | int ip6_local_out(struct sk_buff *skb) | |
74 | { | |
75 | int err; | |
76 | ||
77 | err = __ip6_local_out(skb); | |
78 | if (likely(err == 1)) | |
79 | err = dst_output(skb); | |
80 | ||
81 | return err; | |
82 | } | |
83 | EXPORT_SYMBOL_GPL(ip6_local_out); | |
84 | ||
85 | /* dev_loopback_xmit for use with netfilter. */ | |
86 | static int ip6_dev_loopback_xmit(struct sk_buff *newskb) | |
87 | { | |
88 | skb_reset_mac_header(newskb); | |
89 | __skb_pull(newskb, skb_network_offset(newskb)); | |
90 | newskb->pkt_type = PACKET_LOOPBACK; | |
91 | newskb->ip_summed = CHECKSUM_UNNECESSARY; | |
92 | WARN_ON(!skb_dst(newskb)); | |
93 | ||
94 | netif_rx(newskb); | |
95 | return 0; | |
96 | } | |
97 | ||
98 | static int ip6_finish_output2(struct sk_buff *skb) | |
99 | { | |
100 | struct dst_entry *dst = skb_dst(skb); | |
101 | struct net_device *dev = dst->dev; | |
102 | ||
103 | skb->protocol = htons(ETH_P_IPV6); | |
104 | skb->dev = dev; | |
105 | ||
106 | if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) { | |
107 | struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); | |
108 | ||
109 | if (!(dev->flags & IFF_LOOPBACK) && sk_mc_loop(skb->sk) && | |
110 | ((mroute6_socket(dev_net(dev)) && | |
111 | !(IP6CB(skb)->flags & IP6SKB_FORWARDED)) || | |
112 | ipv6_chk_mcast_addr(dev, &ipv6_hdr(skb)->daddr, | |
113 | &ipv6_hdr(skb)->saddr))) { | |
114 | struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); | |
115 | ||
116 | /* Do not check for IFF_ALLMULTI; multicast routing | |
117 | is not supported in any case. | |
118 | */ | |
119 | if (newskb) | |
120 | NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING, | |
121 | newskb, NULL, newskb->dev, | |
122 | ip6_dev_loopback_xmit); | |
123 | ||
124 | if (ipv6_hdr(skb)->hop_limit == 0) { | |
125 | IP6_INC_STATS(dev_net(dev), idev, | |
126 | IPSTATS_MIB_OUTDISCARDS); | |
127 | kfree_skb(skb); | |
128 | return 0; | |
129 | } | |
130 | } | |
131 | ||
132 | IP6_UPD_PO_STATS(dev_net(dev), idev, IPSTATS_MIB_OUTMCAST, | |
133 | skb->len); | |
134 | } | |
135 | ||
136 | if (dst->hh) | |
137 | return neigh_hh_output(dst->hh, skb); | |
138 | else if (dst->neighbour) | |
139 | return dst->neighbour->output(skb); | |
140 | ||
141 | IP6_INC_STATS_BH(dev_net(dst->dev), | |
142 | ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES); | |
143 | kfree_skb(skb); | |
144 | return -EINVAL; | |
145 | } | |
146 | ||
147 | static inline int ip6_skb_dst_mtu(struct sk_buff *skb) | |
148 | { | |
149 | struct ipv6_pinfo *np = skb->sk ? inet6_sk(skb->sk) : NULL; | |
150 | ||
151 | return (np && np->pmtudisc == IPV6_PMTUDISC_PROBE) ? | |
152 | skb_dst(skb)->dev->mtu : dst_mtu(skb_dst(skb)); | |
153 | } | |
154 | ||
155 | static int ip6_finish_output(struct sk_buff *skb) | |
156 | { | |
157 | if ((skb->len > ip6_skb_dst_mtu(skb) && !skb_is_gso(skb)) || | |
158 | dst_allfrag(skb_dst(skb))) | |
159 | return ip6_fragment(skb, ip6_finish_output2); | |
160 | else | |
161 | return ip6_finish_output2(skb); | |
162 | } | |
163 | ||
164 | int ip6_output(struct sk_buff *skb) | |
165 | { | |
166 | struct net_device *dev = skb_dst(skb)->dev; | |
167 | struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); | |
168 | if (unlikely(idev->cnf.disable_ipv6)) { | |
169 | IP6_INC_STATS(dev_net(dev), idev, | |
170 | IPSTATS_MIB_OUTDISCARDS); | |
171 | kfree_skb(skb); | |
172 | return 0; | |
173 | } | |
174 | ||
175 | return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING, skb, NULL, dev, | |
176 | ip6_finish_output, | |
177 | !(IP6CB(skb)->flags & IP6SKB_REROUTED)); | |
178 | } | |
179 | EXPORT_SYMBOL_GPL(ip6_output); | |
180 | ||
181 | /* | |
182 | * xmit an sk_buff (used by TCP) | |
183 | */ | |
184 | ||
185 | int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl, | |
186 | struct ipv6_txoptions *opt, int ipfragok) | |
187 | { | |
188 | struct net *net = sock_net(sk); | |
189 | struct ipv6_pinfo *np = inet6_sk(sk); | |
190 | struct in6_addr *first_hop = &fl->fl6_dst; | |
191 | struct dst_entry *dst = skb_dst(skb); | |
192 | struct ipv6hdr *hdr; | |
193 | u8 proto = fl->proto; | |
194 | int seg_len = skb->len; | |
195 | int hlimit = -1; | |
196 | int tclass = 0; | |
197 | u32 mtu; | |
198 | ||
199 | if (opt) { | |
200 | unsigned int head_room; | |
201 | ||
202 | /* First: exthdrs may take lots of space (~8K for now) | |
203 | MAX_HEADER is not enough. | |
204 | */ | |
205 | head_room = opt->opt_nflen + opt->opt_flen; | |
206 | seg_len += head_room; | |
207 | head_room += sizeof(struct ipv6hdr) + LL_RESERVED_SPACE(dst->dev); | |
208 | ||
209 | if (skb_headroom(skb) < head_room) { | |
210 | struct sk_buff *skb2 = skb_realloc_headroom(skb, head_room); | |
211 | if (skb2 == NULL) { | |
212 | IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), | |
213 | IPSTATS_MIB_OUTDISCARDS); | |
214 | kfree_skb(skb); | |
215 | return -ENOBUFS; | |
216 | } | |
217 | kfree_skb(skb); | |
218 | skb = skb2; | |
219 | if (sk) | |
220 | skb_set_owner_w(skb, sk); | |
221 | } | |
222 | if (opt->opt_flen) | |
223 | ipv6_push_frag_opts(skb, opt, &proto); | |
224 | if (opt->opt_nflen) | |
225 | ipv6_push_nfrag_opts(skb, opt, &proto, &first_hop); | |
226 | } | |
227 | ||
228 | skb_push(skb, sizeof(struct ipv6hdr)); | |
229 | skb_reset_network_header(skb); | |
230 | hdr = ipv6_hdr(skb); | |
231 | ||
232 | /* Allow local fragmentation. */ | |
233 | if (ipfragok) | |
234 | skb->local_df = 1; | |
235 | ||
236 | /* | |
237 | * Fill in the IPv6 header | |
238 | */ | |
239 | if (np) { | |
240 | tclass = np->tclass; | |
241 | hlimit = np->hop_limit; | |
242 | } | |
243 | if (hlimit < 0) | |
244 | hlimit = ip6_dst_hoplimit(dst); | |
245 | ||
246 | *(__be32 *)hdr = htonl(0x60000000 | (tclass << 20)) | fl->fl6_flowlabel; | |
247 | ||
248 | hdr->payload_len = htons(seg_len); | |
249 | hdr->nexthdr = proto; | |
250 | hdr->hop_limit = hlimit; | |
251 | ||
252 | ipv6_addr_copy(&hdr->saddr, &fl->fl6_src); | |
253 | ipv6_addr_copy(&hdr->daddr, first_hop); | |
254 | ||
255 | skb->priority = sk->sk_priority; | |
256 | skb->mark = sk->sk_mark; | |
257 | ||
258 | mtu = dst_mtu(dst); | |
259 | if ((skb->len <= mtu) || skb->local_df || skb_is_gso(skb)) { | |
260 | IP6_UPD_PO_STATS(net, ip6_dst_idev(skb_dst(skb)), | |
261 | IPSTATS_MIB_OUT, skb->len); | |
262 | return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, skb, NULL, | |
263 | dst->dev, dst_output); | |
264 | } | |
265 | ||
266 | if (net_ratelimit()) | |
267 | printk(KERN_DEBUG "IPv6: sending pkt_too_big to self\n"); | |
268 | skb->dev = dst->dev; | |
269 | icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); | |
270 | IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_FRAGFAILS); | |
271 | kfree_skb(skb); | |
272 | return -EMSGSIZE; | |
273 | } | |
274 | ||
275 | EXPORT_SYMBOL(ip6_xmit); | |
276 | ||
277 | /* | |
278 | * To avoid extra problems ND packets are send through this | |
279 | * routine. It's code duplication but I really want to avoid | |
280 | * extra checks since ipv6_build_header is used by TCP (which | |
281 | * is for us performance critical) | |
282 | */ | |
283 | ||
284 | int ip6_nd_hdr(struct sock *sk, struct sk_buff *skb, struct net_device *dev, | |
285 | const struct in6_addr *saddr, const struct in6_addr *daddr, | |
286 | int proto, int len) | |
287 | { | |
288 | struct ipv6_pinfo *np = inet6_sk(sk); | |
289 | struct ipv6hdr *hdr; | |
290 | int totlen; | |
291 | ||
292 | skb->protocol = htons(ETH_P_IPV6); | |
293 | skb->dev = dev; | |
294 | ||
295 | totlen = len + sizeof(struct ipv6hdr); | |
296 | ||
297 | skb_reset_network_header(skb); | |
298 | skb_put(skb, sizeof(struct ipv6hdr)); | |
299 | hdr = ipv6_hdr(skb); | |
300 | ||
301 | *(__be32*)hdr = htonl(0x60000000); | |
302 | ||
303 | hdr->payload_len = htons(len); | |
304 | hdr->nexthdr = proto; | |
305 | hdr->hop_limit = np->hop_limit; | |
306 | ||
307 | ipv6_addr_copy(&hdr->saddr, saddr); | |
308 | ipv6_addr_copy(&hdr->daddr, daddr); | |
309 | ||
310 | return 0; | |
311 | } | |
312 | ||
313 | static int ip6_call_ra_chain(struct sk_buff *skb, int sel) | |
314 | { | |
315 | struct ip6_ra_chain *ra; | |
316 | struct sock *last = NULL; | |
317 | ||
318 | read_lock(&ip6_ra_lock); | |
319 | for (ra = ip6_ra_chain; ra; ra = ra->next) { | |
320 | struct sock *sk = ra->sk; | |
321 | if (sk && ra->sel == sel && | |
322 | (!sk->sk_bound_dev_if || | |
323 | sk->sk_bound_dev_if == skb->dev->ifindex)) { | |
324 | if (last) { | |
325 | struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); | |
326 | if (skb2) | |
327 | rawv6_rcv(last, skb2); | |
328 | } | |
329 | last = sk; | |
330 | } | |
331 | } | |
332 | ||
333 | if (last) { | |
334 | rawv6_rcv(last, skb); | |
335 | read_unlock(&ip6_ra_lock); | |
336 | return 1; | |
337 | } | |
338 | read_unlock(&ip6_ra_lock); | |
339 | return 0; | |
340 | } | |
341 | ||
342 | static int ip6_forward_proxy_check(struct sk_buff *skb) | |
343 | { | |
344 | struct ipv6hdr *hdr = ipv6_hdr(skb); | |
345 | u8 nexthdr = hdr->nexthdr; | |
346 | int offset; | |
347 | ||
348 | if (ipv6_ext_hdr(nexthdr)) { | |
349 | offset = ipv6_skip_exthdr(skb, sizeof(*hdr), &nexthdr); | |
350 | if (offset < 0) | |
351 | return 0; | |
352 | } else | |
353 | offset = sizeof(struct ipv6hdr); | |
354 | ||
355 | if (nexthdr == IPPROTO_ICMPV6) { | |
356 | struct icmp6hdr *icmp6; | |
357 | ||
358 | if (!pskb_may_pull(skb, (skb_network_header(skb) + | |
359 | offset + 1 - skb->data))) | |
360 | return 0; | |
361 | ||
362 | icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset); | |
363 | ||
364 | switch (icmp6->icmp6_type) { | |
365 | case NDISC_ROUTER_SOLICITATION: | |
366 | case NDISC_ROUTER_ADVERTISEMENT: | |
367 | case NDISC_NEIGHBOUR_SOLICITATION: | |
368 | case NDISC_NEIGHBOUR_ADVERTISEMENT: | |
369 | case NDISC_REDIRECT: | |
370 | /* For reaction involving unicast neighbor discovery | |
371 | * message destined to the proxied address, pass it to | |
372 | * input function. | |
373 | */ | |
374 | return 1; | |
375 | default: | |
376 | break; | |
377 | } | |
378 | } | |
379 | ||
380 | /* | |
381 | * The proxying router can't forward traffic sent to a link-local | |
382 | * address, so signal the sender and discard the packet. This | |
383 | * behavior is clarified by the MIPv6 specification. | |
384 | */ | |
385 | if (ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) { | |
386 | dst_link_failure(skb); | |
387 | return -1; | |
388 | } | |
389 | ||
390 | return 0; | |
391 | } | |
392 | ||
393 | static inline int ip6_forward_finish(struct sk_buff *skb) | |
394 | { | |
395 | return dst_output(skb); | |
396 | } | |
397 | ||
398 | int ip6_forward(struct sk_buff *skb) | |
399 | { | |
400 | struct dst_entry *dst = skb_dst(skb); | |
401 | struct ipv6hdr *hdr = ipv6_hdr(skb); | |
402 | struct inet6_skb_parm *opt = IP6CB(skb); | |
403 | struct net *net = dev_net(dst->dev); | |
404 | u32 mtu; | |
405 | ||
406 | if (net->ipv6.devconf_all->forwarding == 0) | |
407 | goto error; | |
408 | ||
409 | if (skb_warn_if_lro(skb)) | |
410 | goto drop; | |
411 | ||
412 | if (!xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) { | |
413 | IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS); | |
414 | goto drop; | |
415 | } | |
416 | ||
417 | skb_forward_csum(skb); | |
418 | ||
419 | /* | |
420 | * We DO NOT make any processing on | |
421 | * RA packets, pushing them to user level AS IS | |
422 | * without ane WARRANTY that application will be able | |
423 | * to interpret them. The reason is that we | |
424 | * cannot make anything clever here. | |
425 | * | |
426 | * We are not end-node, so that if packet contains | |
427 | * AH/ESP, we cannot make anything. | |
428 | * Defragmentation also would be mistake, RA packets | |
429 | * cannot be fragmented, because there is no warranty | |
430 | * that different fragments will go along one path. --ANK | |
431 | */ | |
432 | if (opt->ra) { | |
433 | u8 *ptr = skb_network_header(skb) + opt->ra; | |
434 | if (ip6_call_ra_chain(skb, (ptr[2]<<8) + ptr[3])) | |
435 | return 0; | |
436 | } | |
437 | ||
438 | /* | |
439 | * check and decrement ttl | |
440 | */ | |
441 | if (hdr->hop_limit <= 1) { | |
442 | /* Force OUTPUT device used as source address */ | |
443 | skb->dev = dst->dev; | |
444 | icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 0); | |
445 | IP6_INC_STATS_BH(net, | |
446 | ip6_dst_idev(dst), IPSTATS_MIB_INHDRERRORS); | |
447 | ||
448 | kfree_skb(skb); | |
449 | return -ETIMEDOUT; | |
450 | } | |
451 | ||
452 | /* XXX: idev->cnf.proxy_ndp? */ | |
453 | if (net->ipv6.devconf_all->proxy_ndp && | |
454 | pneigh_lookup(&nd_tbl, net, &hdr->daddr, skb->dev, 0)) { | |
455 | int proxied = ip6_forward_proxy_check(skb); | |
456 | if (proxied > 0) | |
457 | return ip6_input(skb); | |
458 | else if (proxied < 0) { | |
459 | IP6_INC_STATS(net, ip6_dst_idev(dst), | |
460 | IPSTATS_MIB_INDISCARDS); | |
461 | goto drop; | |
462 | } | |
463 | } | |
464 | ||
465 | if (!xfrm6_route_forward(skb)) { | |
466 | IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS); | |
467 | goto drop; | |
468 | } | |
469 | dst = skb_dst(skb); | |
470 | ||
471 | /* IPv6 specs say nothing about it, but it is clear that we cannot | |
472 | send redirects to source routed frames. | |
473 | We don't send redirects to frames decapsulated from IPsec. | |
474 | */ | |
475 | if (skb->dev == dst->dev && dst->neighbour && opt->srcrt == 0 && | |
476 | !skb_sec_path(skb)) { | |
477 | struct in6_addr *target = NULL; | |
478 | struct rt6_info *rt; | |
479 | struct neighbour *n = dst->neighbour; | |
480 | ||
481 | /* | |
482 | * incoming and outgoing devices are the same | |
483 | * send a redirect. | |
484 | */ | |
485 | ||
486 | rt = (struct rt6_info *) dst; | |
487 | if ((rt->rt6i_flags & RTF_GATEWAY)) | |
488 | target = (struct in6_addr*)&n->primary_key; | |
489 | else | |
490 | target = &hdr->daddr; | |
491 | ||
492 | /* Limit redirects both by destination (here) | |
493 | and by source (inside ndisc_send_redirect) | |
494 | */ | |
495 | if (xrlim_allow(dst, 1*HZ)) | |
496 | ndisc_send_redirect(skb, n, target); | |
497 | } else { | |
498 | int addrtype = ipv6_addr_type(&hdr->saddr); | |
499 | ||
500 | /* This check is security critical. */ | |
501 | if (addrtype == IPV6_ADDR_ANY || | |
502 | addrtype & (IPV6_ADDR_MULTICAST | IPV6_ADDR_LOOPBACK)) | |
503 | goto error; | |
504 | if (addrtype & IPV6_ADDR_LINKLOCAL) { | |
505 | icmpv6_send(skb, ICMPV6_DEST_UNREACH, | |
506 | ICMPV6_NOT_NEIGHBOUR, 0); | |
507 | goto error; | |
508 | } | |
509 | } | |
510 | ||
511 | mtu = dst_mtu(dst); | |
512 | if (mtu < IPV6_MIN_MTU) | |
513 | mtu = IPV6_MIN_MTU; | |
514 | ||
515 | if (skb->len > mtu) { | |
516 | /* Again, force OUTPUT device used as source address */ | |
517 | skb->dev = dst->dev; | |
518 | icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); | |
519 | IP6_INC_STATS_BH(net, | |
520 | ip6_dst_idev(dst), IPSTATS_MIB_INTOOBIGERRORS); | |
521 | IP6_INC_STATS_BH(net, | |
522 | ip6_dst_idev(dst), IPSTATS_MIB_FRAGFAILS); | |
523 | kfree_skb(skb); | |
524 | return -EMSGSIZE; | |
525 | } | |
526 | ||
527 | if (skb_cow(skb, dst->dev->hard_header_len)) { | |
528 | IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTDISCARDS); | |
529 | goto drop; | |
530 | } | |
531 | ||
532 | hdr = ipv6_hdr(skb); | |
533 | ||
534 | /* Mangling hops number delayed to point after skb COW */ | |
535 | ||
536 | hdr->hop_limit--; | |
537 | ||
538 | IP6_INC_STATS_BH(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTFORWDATAGRAMS); | |
539 | return NF_HOOK(NFPROTO_IPV6, NF_INET_FORWARD, skb, skb->dev, dst->dev, | |
540 | ip6_forward_finish); | |
541 | ||
542 | error: | |
543 | IP6_INC_STATS_BH(net, ip6_dst_idev(dst), IPSTATS_MIB_INADDRERRORS); | |
544 | drop: | |
545 | kfree_skb(skb); | |
546 | return -EINVAL; | |
547 | } | |
548 | ||
549 | static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from) | |
550 | { | |
551 | to->pkt_type = from->pkt_type; | |
552 | to->priority = from->priority; | |
553 | to->protocol = from->protocol; | |
554 | skb_dst_drop(to); | |
555 | skb_dst_set(to, dst_clone(skb_dst(from))); | |
556 | to->dev = from->dev; | |
557 | to->mark = from->mark; | |
558 | ||
559 | #ifdef CONFIG_NET_SCHED | |
560 | to->tc_index = from->tc_index; | |
561 | #endif | |
562 | nf_copy(to, from); | |
563 | #if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \ | |
564 | defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE) | |
565 | to->nf_trace = from->nf_trace; | |
566 | #endif | |
567 | skb_copy_secmark(to, from); | |
568 | } | |
569 | ||
570 | int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr) | |
571 | { | |
572 | u16 offset = sizeof(struct ipv6hdr); | |
573 | struct ipv6_opt_hdr *exthdr = | |
574 | (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1); | |
575 | unsigned int packet_len = skb->tail - skb->network_header; | |
576 | int found_rhdr = 0; | |
577 | *nexthdr = &ipv6_hdr(skb)->nexthdr; | |
578 | ||
579 | while (offset + 1 <= packet_len) { | |
580 | ||
581 | switch (**nexthdr) { | |
582 | ||
583 | case NEXTHDR_HOP: | |
584 | break; | |
585 | case NEXTHDR_ROUTING: | |
586 | found_rhdr = 1; | |
587 | break; | |
588 | case NEXTHDR_DEST: | |
589 | #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) | |
590 | if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0) | |
591 | break; | |
592 | #endif | |
593 | if (found_rhdr) | |
594 | return offset; | |
595 | break; | |
596 | default : | |
597 | return offset; | |
598 | } | |
599 | ||
600 | offset += ipv6_optlen(exthdr); | |
601 | *nexthdr = &exthdr->nexthdr; | |
602 | exthdr = (struct ipv6_opt_hdr *)(skb_network_header(skb) + | |
603 | offset); | |
604 | } | |
605 | ||
606 | return offset; | |
607 | } | |
608 | ||
609 | static int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *)) | |
610 | { | |
611 | struct sk_buff *frag; | |
612 | struct rt6_info *rt = (struct rt6_info*)skb_dst(skb); | |
613 | struct ipv6_pinfo *np = skb->sk ? inet6_sk(skb->sk) : NULL; | |
614 | struct ipv6hdr *tmp_hdr; | |
615 | struct frag_hdr *fh; | |
616 | unsigned int mtu, hlen, left, len; | |
617 | __be32 frag_id = 0; | |
618 | int ptr, offset = 0, err=0; | |
619 | u8 *prevhdr, nexthdr = 0; | |
620 | struct net *net = dev_net(skb_dst(skb)->dev); | |
621 | ||
622 | hlen = ip6_find_1stfragopt(skb, &prevhdr); | |
623 | nexthdr = *prevhdr; | |
624 | ||
625 | mtu = ip6_skb_dst_mtu(skb); | |
626 | ||
627 | /* We must not fragment if the socket is set to force MTU discovery | |
628 | * or if the skb it not generated by a local socket. | |
629 | */ | |
630 | if (!skb->local_df) { | |
631 | skb->dev = skb_dst(skb)->dev; | |
632 | icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); | |
633 | IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), | |
634 | IPSTATS_MIB_FRAGFAILS); | |
635 | kfree_skb(skb); | |
636 | return -EMSGSIZE; | |
637 | } | |
638 | ||
639 | if (np && np->frag_size < mtu) { | |
640 | if (np->frag_size) | |
641 | mtu = np->frag_size; | |
642 | } | |
643 | mtu -= hlen + sizeof(struct frag_hdr); | |
644 | ||
645 | if (skb_has_frags(skb)) { | |
646 | int first_len = skb_pagelen(skb); | |
647 | int truesizes = 0; | |
648 | ||
649 | if (first_len - hlen > mtu || | |
650 | ((first_len - hlen) & 7) || | |
651 | skb_cloned(skb)) | |
652 | goto slow_path; | |
653 | ||
654 | skb_walk_frags(skb, frag) { | |
655 | /* Correct geometry. */ | |
656 | if (frag->len > mtu || | |
657 | ((frag->len & 7) && frag->next) || | |
658 | skb_headroom(frag) < hlen) | |
659 | goto slow_path; | |
660 | ||
661 | /* Partially cloned skb? */ | |
662 | if (skb_shared(frag)) | |
663 | goto slow_path; | |
664 | ||
665 | BUG_ON(frag->sk); | |
666 | if (skb->sk) { | |
667 | frag->sk = skb->sk; | |
668 | frag->destructor = sock_wfree; | |
669 | truesizes += frag->truesize; | |
670 | } | |
671 | } | |
672 | ||
673 | err = 0; | |
674 | offset = 0; | |
675 | frag = skb_shinfo(skb)->frag_list; | |
676 | skb_frag_list_init(skb); | |
677 | /* BUILD HEADER */ | |
678 | ||
679 | *prevhdr = NEXTHDR_FRAGMENT; | |
680 | tmp_hdr = kmemdup(skb_network_header(skb), hlen, GFP_ATOMIC); | |
681 | if (!tmp_hdr) { | |
682 | IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), | |
683 | IPSTATS_MIB_FRAGFAILS); | |
684 | return -ENOMEM; | |
685 | } | |
686 | ||
687 | __skb_pull(skb, hlen); | |
688 | fh = (struct frag_hdr*)__skb_push(skb, sizeof(struct frag_hdr)); | |
689 | __skb_push(skb, hlen); | |
690 | skb_reset_network_header(skb); | |
691 | memcpy(skb_network_header(skb), tmp_hdr, hlen); | |
692 | ||
693 | ipv6_select_ident(fh); | |
694 | fh->nexthdr = nexthdr; | |
695 | fh->reserved = 0; | |
696 | fh->frag_off = htons(IP6_MF); | |
697 | frag_id = fh->identification; | |
698 | ||
699 | first_len = skb_pagelen(skb); | |
700 | skb->data_len = first_len - skb_headlen(skb); | |
701 | skb->truesize -= truesizes; | |
702 | skb->len = first_len; | |
703 | ipv6_hdr(skb)->payload_len = htons(first_len - | |
704 | sizeof(struct ipv6hdr)); | |
705 | ||
706 | dst_hold(&rt->u.dst); | |
707 | ||
708 | for (;;) { | |
709 | /* Prepare header of the next frame, | |
710 | * before previous one went down. */ | |
711 | if (frag) { | |
712 | frag->ip_summed = CHECKSUM_NONE; | |
713 | skb_reset_transport_header(frag); | |
714 | fh = (struct frag_hdr*)__skb_push(frag, sizeof(struct frag_hdr)); | |
715 | __skb_push(frag, hlen); | |
716 | skb_reset_network_header(frag); | |
717 | memcpy(skb_network_header(frag), tmp_hdr, | |
718 | hlen); | |
719 | offset += skb->len - hlen - sizeof(struct frag_hdr); | |
720 | fh->nexthdr = nexthdr; | |
721 | fh->reserved = 0; | |
722 | fh->frag_off = htons(offset); | |
723 | if (frag->next != NULL) | |
724 | fh->frag_off |= htons(IP6_MF); | |
725 | fh->identification = frag_id; | |
726 | ipv6_hdr(frag)->payload_len = | |
727 | htons(frag->len - | |
728 | sizeof(struct ipv6hdr)); | |
729 | ip6_copy_metadata(frag, skb); | |
730 | } | |
731 | ||
732 | err = output(skb); | |
733 | if(!err) | |
734 | IP6_INC_STATS(net, ip6_dst_idev(&rt->u.dst), | |
735 | IPSTATS_MIB_FRAGCREATES); | |
736 | ||
737 | if (err || !frag) | |
738 | break; | |
739 | ||
740 | skb = frag; | |
741 | frag = skb->next; | |
742 | skb->next = NULL; | |
743 | } | |
744 | ||
745 | kfree(tmp_hdr); | |
746 | ||
747 | if (err == 0) { | |
748 | IP6_INC_STATS(net, ip6_dst_idev(&rt->u.dst), | |
749 | IPSTATS_MIB_FRAGOKS); | |
750 | dst_release(&rt->u.dst); | |
751 | return 0; | |
752 | } | |
753 | ||
754 | while (frag) { | |
755 | skb = frag->next; | |
756 | kfree_skb(frag); | |
757 | frag = skb; | |
758 | } | |
759 | ||
760 | IP6_INC_STATS(net, ip6_dst_idev(&rt->u.dst), | |
761 | IPSTATS_MIB_FRAGFAILS); | |
762 | dst_release(&rt->u.dst); | |
763 | return err; | |
764 | } | |
765 | ||
766 | slow_path: | |
767 | left = skb->len - hlen; /* Space per frame */ | |
768 | ptr = hlen; /* Where to start from */ | |
769 | ||
770 | /* | |
771 | * Fragment the datagram. | |
772 | */ | |
773 | ||
774 | *prevhdr = NEXTHDR_FRAGMENT; | |
775 | ||
776 | /* | |
777 | * Keep copying data until we run out. | |
778 | */ | |
779 | while(left > 0) { | |
780 | len = left; | |
781 | /* IF: it doesn't fit, use 'mtu' - the data space left */ | |
782 | if (len > mtu) | |
783 | len = mtu; | |
784 | /* IF: we are not sending upto and including the packet end | |
785 | then align the next start on an eight byte boundary */ | |
786 | if (len < left) { | |
787 | len &= ~7; | |
788 | } | |
789 | /* | |
790 | * Allocate buffer. | |
791 | */ | |
792 | ||
793 | if ((frag = alloc_skb(len+hlen+sizeof(struct frag_hdr)+LL_ALLOCATED_SPACE(rt->u.dst.dev), GFP_ATOMIC)) == NULL) { | |
794 | NETDEBUG(KERN_INFO "IPv6: frag: no memory for new fragment!\n"); | |
795 | IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), | |
796 | IPSTATS_MIB_FRAGFAILS); | |
797 | err = -ENOMEM; | |
798 | goto fail; | |
799 | } | |
800 | ||
801 | /* | |
802 | * Set up data on packet | |
803 | */ | |
804 | ||
805 | ip6_copy_metadata(frag, skb); | |
806 | skb_reserve(frag, LL_RESERVED_SPACE(rt->u.dst.dev)); | |
807 | skb_put(frag, len + hlen + sizeof(struct frag_hdr)); | |
808 | skb_reset_network_header(frag); | |
809 | fh = (struct frag_hdr *)(skb_network_header(frag) + hlen); | |
810 | frag->transport_header = (frag->network_header + hlen + | |
811 | sizeof(struct frag_hdr)); | |
812 | ||
813 | /* | |
814 | * Charge the memory for the fragment to any owner | |
815 | * it might possess | |
816 | */ | |
817 | if (skb->sk) | |
818 | skb_set_owner_w(frag, skb->sk); | |
819 | ||
820 | /* | |
821 | * Copy the packet header into the new buffer. | |
822 | */ | |
823 | skb_copy_from_linear_data(skb, skb_network_header(frag), hlen); | |
824 | ||
825 | /* | |
826 | * Build fragment header. | |
827 | */ | |
828 | fh->nexthdr = nexthdr; | |
829 | fh->reserved = 0; | |
830 | if (!frag_id) { | |
831 | ipv6_select_ident(fh); | |
832 | frag_id = fh->identification; | |
833 | } else | |
834 | fh->identification = frag_id; | |
835 | ||
836 | /* | |
837 | * Copy a block of the IP datagram. | |
838 | */ | |
839 | if (skb_copy_bits(skb, ptr, skb_transport_header(frag), len)) | |
840 | BUG(); | |
841 | left -= len; | |
842 | ||
843 | fh->frag_off = htons(offset); | |
844 | if (left > 0) | |
845 | fh->frag_off |= htons(IP6_MF); | |
846 | ipv6_hdr(frag)->payload_len = htons(frag->len - | |
847 | sizeof(struct ipv6hdr)); | |
848 | ||
849 | ptr += len; | |
850 | offset += len; | |
851 | ||
852 | /* | |
853 | * Put this fragment into the sending queue. | |
854 | */ | |
855 | err = output(frag); | |
856 | if (err) | |
857 | goto fail; | |
858 | ||
859 | IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), | |
860 | IPSTATS_MIB_FRAGCREATES); | |
861 | } | |
862 | IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), | |
863 | IPSTATS_MIB_FRAGOKS); | |
864 | kfree_skb(skb); | |
865 | return err; | |
866 | ||
867 | fail: | |
868 | IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), | |
869 | IPSTATS_MIB_FRAGFAILS); | |
870 | kfree_skb(skb); | |
871 | return err; | |
872 | } | |
873 | ||
874 | static inline int ip6_rt_check(struct rt6key *rt_key, | |
875 | struct in6_addr *fl_addr, | |
876 | struct in6_addr *addr_cache) | |
877 | { | |
878 | return ((rt_key->plen != 128 || !ipv6_addr_equal(fl_addr, &rt_key->addr)) && | |
879 | (addr_cache == NULL || !ipv6_addr_equal(fl_addr, addr_cache))); | |
880 | } | |
881 | ||
882 | static struct dst_entry *ip6_sk_dst_check(struct sock *sk, | |
883 | struct dst_entry *dst, | |
884 | struct flowi *fl) | |
885 | { | |
886 | struct ipv6_pinfo *np = inet6_sk(sk); | |
887 | struct rt6_info *rt = (struct rt6_info *)dst; | |
888 | ||
889 | if (!dst) | |
890 | goto out; | |
891 | ||
892 | /* Yes, checking route validity in not connected | |
893 | * case is not very simple. Take into account, | |
894 | * that we do not support routing by source, TOS, | |
895 | * and MSG_DONTROUTE --ANK (980726) | |
896 | * | |
897 | * 1. ip6_rt_check(): If route was host route, | |
898 | * check that cached destination is current. | |
899 | * If it is network route, we still may | |
900 | * check its validity using saved pointer | |
901 | * to the last used address: daddr_cache. | |
902 | * We do not want to save whole address now, | |
903 | * (because main consumer of this service | |
904 | * is tcp, which has not this problem), | |
905 | * so that the last trick works only on connected | |
906 | * sockets. | |
907 | * 2. oif also should be the same. | |
908 | */ | |
909 | if (ip6_rt_check(&rt->rt6i_dst, &fl->fl6_dst, np->daddr_cache) || | |
910 | #ifdef CONFIG_IPV6_SUBTREES | |
911 | ip6_rt_check(&rt->rt6i_src, &fl->fl6_src, np->saddr_cache) || | |
912 | #endif | |
913 | (fl->oif && fl->oif != dst->dev->ifindex)) { | |
914 | dst_release(dst); | |
915 | dst = NULL; | |
916 | } | |
917 | ||
918 | out: | |
919 | return dst; | |
920 | } | |
921 | ||
922 | static int ip6_dst_lookup_tail(struct sock *sk, | |
923 | struct dst_entry **dst, struct flowi *fl) | |
924 | { | |
925 | int err; | |
926 | struct net *net = sock_net(sk); | |
927 | ||
928 | if (*dst == NULL) | |
929 | *dst = ip6_route_output(net, sk, fl); | |
930 | ||
931 | if ((err = (*dst)->error)) | |
932 | goto out_err_release; | |
933 | ||
934 | if (ipv6_addr_any(&fl->fl6_src)) { | |
935 | err = ipv6_dev_get_saddr(net, ip6_dst_idev(*dst)->dev, | |
936 | &fl->fl6_dst, | |
937 | sk ? inet6_sk(sk)->srcprefs : 0, | |
938 | &fl->fl6_src); | |
939 | if (err) | |
940 | goto out_err_release; | |
941 | } | |
942 | ||
943 | #ifdef CONFIG_IPV6_OPTIMISTIC_DAD | |
944 | /* | |
945 | * Here if the dst entry we've looked up | |
946 | * has a neighbour entry that is in the INCOMPLETE | |
947 | * state and the src address from the flow is | |
948 | * marked as OPTIMISTIC, we release the found | |
949 | * dst entry and replace it instead with the | |
950 | * dst entry of the nexthop router | |
951 | */ | |
952 | if ((*dst)->neighbour && !((*dst)->neighbour->nud_state & NUD_VALID)) { | |
953 | struct inet6_ifaddr *ifp; | |
954 | struct flowi fl_gw; | |
955 | int redirect; | |
956 | ||
957 | ifp = ipv6_get_ifaddr(net, &fl->fl6_src, | |
958 | (*dst)->dev, 1); | |
959 | ||
960 | redirect = (ifp && ifp->flags & IFA_F_OPTIMISTIC); | |
961 | if (ifp) | |
962 | in6_ifa_put(ifp); | |
963 | ||
964 | if (redirect) { | |
965 | /* | |
966 | * We need to get the dst entry for the | |
967 | * default router instead | |
968 | */ | |
969 | dst_release(*dst); | |
970 | memcpy(&fl_gw, fl, sizeof(struct flowi)); | |
971 | memset(&fl_gw.fl6_dst, 0, sizeof(struct in6_addr)); | |
972 | *dst = ip6_route_output(net, sk, &fl_gw); | |
973 | if ((err = (*dst)->error)) | |
974 | goto out_err_release; | |
975 | } | |
976 | } | |
977 | #endif | |
978 | ||
979 | return 0; | |
980 | ||
981 | out_err_release: | |
982 | if (err == -ENETUNREACH) | |
983 | IP6_INC_STATS_BH(net, NULL, IPSTATS_MIB_OUTNOROUTES); | |
984 | dst_release(*dst); | |
985 | *dst = NULL; | |
986 | return err; | |
987 | } | |
988 | ||
989 | /** | |
990 | * ip6_dst_lookup - perform route lookup on flow | |
991 | * @sk: socket which provides route info | |
992 | * @dst: pointer to dst_entry * for result | |
993 | * @fl: flow to lookup | |
994 | * | |
995 | * This function performs a route lookup on the given flow. | |
996 | * | |
997 | * It returns zero on success, or a standard errno code on error. | |
998 | */ | |
999 | int ip6_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi *fl) | |
1000 | { | |
1001 | *dst = NULL; | |
1002 | return ip6_dst_lookup_tail(sk, dst, fl); | |
1003 | } | |
1004 | EXPORT_SYMBOL_GPL(ip6_dst_lookup); | |
1005 | ||
1006 | /** | |
1007 | * ip6_sk_dst_lookup - perform socket cached route lookup on flow | |
1008 | * @sk: socket which provides the dst cache and route info | |
1009 | * @dst: pointer to dst_entry * for result | |
1010 | * @fl: flow to lookup | |
1011 | * | |
1012 | * This function performs a route lookup on the given flow with the | |
1013 | * possibility of using the cached route in the socket if it is valid. | |
1014 | * It will take the socket dst lock when operating on the dst cache. | |
1015 | * As a result, this function can only be used in process context. | |
1016 | * | |
1017 | * It returns zero on success, or a standard errno code on error. | |
1018 | */ | |
1019 | int ip6_sk_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi *fl) | |
1020 | { | |
1021 | *dst = NULL; | |
1022 | if (sk) { | |
1023 | *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie); | |
1024 | *dst = ip6_sk_dst_check(sk, *dst, fl); | |
1025 | } | |
1026 | ||
1027 | return ip6_dst_lookup_tail(sk, dst, fl); | |
1028 | } | |
1029 | EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup); | |
1030 | ||
1031 | static inline int ip6_ufo_append_data(struct sock *sk, | |
1032 | int getfrag(void *from, char *to, int offset, int len, | |
1033 | int odd, struct sk_buff *skb), | |
1034 | void *from, int length, int hh_len, int fragheaderlen, | |
1035 | int transhdrlen, int mtu,unsigned int flags) | |
1036 | ||
1037 | { | |
1038 | struct sk_buff *skb; | |
1039 | int err; | |
1040 | ||
1041 | /* There is support for UDP large send offload by network | |
1042 | * device, so create one single skb packet containing complete | |
1043 | * udp datagram | |
1044 | */ | |
1045 | if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) { | |
1046 | skb = sock_alloc_send_skb(sk, | |
1047 | hh_len + fragheaderlen + transhdrlen + 20, | |
1048 | (flags & MSG_DONTWAIT), &err); | |
1049 | if (skb == NULL) | |
1050 | return -ENOMEM; | |
1051 | ||
1052 | /* reserve space for Hardware header */ | |
1053 | skb_reserve(skb, hh_len); | |
1054 | ||
1055 | /* create space for UDP/IP header */ | |
1056 | skb_put(skb,fragheaderlen + transhdrlen); | |
1057 | ||
1058 | /* initialize network header pointer */ | |
1059 | skb_reset_network_header(skb); | |
1060 | ||
1061 | /* initialize protocol header pointer */ | |
1062 | skb->transport_header = skb->network_header + fragheaderlen; | |
1063 | ||
1064 | skb->ip_summed = CHECKSUM_PARTIAL; | |
1065 | skb->csum = 0; | |
1066 | sk->sk_sndmsg_off = 0; | |
1067 | } | |
1068 | ||
1069 | err = skb_append_datato_frags(sk,skb, getfrag, from, | |
1070 | (length - transhdrlen)); | |
1071 | if (!err) { | |
1072 | struct frag_hdr fhdr; | |
1073 | ||
1074 | /* Specify the length of each IPv6 datagram fragment. | |
1075 | * It has to be a multiple of 8. | |
1076 | */ | |
1077 | skb_shinfo(skb)->gso_size = (mtu - fragheaderlen - | |
1078 | sizeof(struct frag_hdr)) & ~7; | |
1079 | skb_shinfo(skb)->gso_type = SKB_GSO_UDP; | |
1080 | ipv6_select_ident(&fhdr); | |
1081 | skb_shinfo(skb)->ip6_frag_id = fhdr.identification; | |
1082 | __skb_queue_tail(&sk->sk_write_queue, skb); | |
1083 | ||
1084 | return 0; | |
1085 | } | |
1086 | /* There is not enough support do UPD LSO, | |
1087 | * so follow normal path | |
1088 | */ | |
1089 | kfree_skb(skb); | |
1090 | ||
1091 | return err; | |
1092 | } | |
1093 | ||
1094 | static inline struct ipv6_opt_hdr *ip6_opt_dup(struct ipv6_opt_hdr *src, | |
1095 | gfp_t gfp) | |
1096 | { | |
1097 | return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL; | |
1098 | } | |
1099 | ||
1100 | static inline struct ipv6_rt_hdr *ip6_rthdr_dup(struct ipv6_rt_hdr *src, | |
1101 | gfp_t gfp) | |
1102 | { | |
1103 | return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL; | |
1104 | } | |
1105 | ||
1106 | int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to, | |
1107 | int offset, int len, int odd, struct sk_buff *skb), | |
1108 | void *from, int length, int transhdrlen, | |
1109 | int hlimit, int tclass, struct ipv6_txoptions *opt, struct flowi *fl, | |
1110 | struct rt6_info *rt, unsigned int flags) | |
1111 | { | |
1112 | struct inet_sock *inet = inet_sk(sk); | |
1113 | struct ipv6_pinfo *np = inet6_sk(sk); | |
1114 | struct sk_buff *skb; | |
1115 | unsigned int maxfraglen, fragheaderlen; | |
1116 | int exthdrlen; | |
1117 | int hh_len; | |
1118 | int mtu; | |
1119 | int copy; | |
1120 | int err; | |
1121 | int offset = 0; | |
1122 | int csummode = CHECKSUM_NONE; | |
1123 | ||
1124 | if (flags&MSG_PROBE) | |
1125 | return 0; | |
1126 | if (skb_queue_empty(&sk->sk_write_queue)) { | |
1127 | /* | |
1128 | * setup for corking | |
1129 | */ | |
1130 | if (opt) { | |
1131 | if (WARN_ON(np->cork.opt)) | |
1132 | return -EINVAL; | |
1133 | ||
1134 | np->cork.opt = kmalloc(opt->tot_len, sk->sk_allocation); | |
1135 | if (unlikely(np->cork.opt == NULL)) | |
1136 | return -ENOBUFS; | |
1137 | ||
1138 | np->cork.opt->tot_len = opt->tot_len; | |
1139 | np->cork.opt->opt_flen = opt->opt_flen; | |
1140 | np->cork.opt->opt_nflen = opt->opt_nflen; | |
1141 | ||
1142 | np->cork.opt->dst0opt = ip6_opt_dup(opt->dst0opt, | |
1143 | sk->sk_allocation); | |
1144 | if (opt->dst0opt && !np->cork.opt->dst0opt) | |
1145 | return -ENOBUFS; | |
1146 | ||
1147 | np->cork.opt->dst1opt = ip6_opt_dup(opt->dst1opt, | |
1148 | sk->sk_allocation); | |
1149 | if (opt->dst1opt && !np->cork.opt->dst1opt) | |
1150 | return -ENOBUFS; | |
1151 | ||
1152 | np->cork.opt->hopopt = ip6_opt_dup(opt->hopopt, | |
1153 | sk->sk_allocation); | |
1154 | if (opt->hopopt && !np->cork.opt->hopopt) | |
1155 | return -ENOBUFS; | |
1156 | ||
1157 | np->cork.opt->srcrt = ip6_rthdr_dup(opt->srcrt, | |
1158 | sk->sk_allocation); | |
1159 | if (opt->srcrt && !np->cork.opt->srcrt) | |
1160 | return -ENOBUFS; | |
1161 | ||
1162 | /* need source address above miyazawa*/ | |
1163 | } | |
1164 | dst_hold(&rt->u.dst); | |
1165 | inet->cork.dst = &rt->u.dst; | |
1166 | inet->cork.fl = *fl; | |
1167 | np->cork.hop_limit = hlimit; | |
1168 | np->cork.tclass = tclass; | |
1169 | mtu = np->pmtudisc == IPV6_PMTUDISC_PROBE ? | |
1170 | rt->u.dst.dev->mtu : dst_mtu(rt->u.dst.path); | |
1171 | if (np->frag_size < mtu) { | |
1172 | if (np->frag_size) | |
1173 | mtu = np->frag_size; | |
1174 | } | |
1175 | inet->cork.fragsize = mtu; | |
1176 | if (dst_allfrag(rt->u.dst.path)) | |
1177 | inet->cork.flags |= IPCORK_ALLFRAG; | |
1178 | inet->cork.length = 0; | |
1179 | sk->sk_sndmsg_page = NULL; | |
1180 | sk->sk_sndmsg_off = 0; | |
1181 | exthdrlen = rt->u.dst.header_len + (opt ? opt->opt_flen : 0) - | |
1182 | rt->rt6i_nfheader_len; | |
1183 | length += exthdrlen; | |
1184 | transhdrlen += exthdrlen; | |
1185 | } else { | |
1186 | rt = (struct rt6_info *)inet->cork.dst; | |
1187 | fl = &inet->cork.fl; | |
1188 | opt = np->cork.opt; | |
1189 | transhdrlen = 0; | |
1190 | exthdrlen = 0; | |
1191 | mtu = inet->cork.fragsize; | |
1192 | } | |
1193 | ||
1194 | hh_len = LL_RESERVED_SPACE(rt->u.dst.dev); | |
1195 | ||
1196 | fragheaderlen = sizeof(struct ipv6hdr) + rt->rt6i_nfheader_len + | |
1197 | (opt ? opt->opt_nflen : 0); | |
1198 | maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - sizeof(struct frag_hdr); | |
1199 | ||
1200 | if (mtu <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN) { | |
1201 | if (inet->cork.length + length > sizeof(struct ipv6hdr) + IPV6_MAXPLEN - fragheaderlen) { | |
1202 | ipv6_local_error(sk, EMSGSIZE, fl, mtu-exthdrlen); | |
1203 | return -EMSGSIZE; | |
1204 | } | |
1205 | } | |
1206 | ||
1207 | /* | |
1208 | * Let's try using as much space as possible. | |
1209 | * Use MTU if total length of the message fits into the MTU. | |
1210 | * Otherwise, we need to reserve fragment header and | |
1211 | * fragment alignment (= 8-15 octects, in total). | |
1212 | * | |
1213 | * Note that we may need to "move" the data from the tail of | |
1214 | * of the buffer to the new fragment when we split | |
1215 | * the message. | |
1216 | * | |
1217 | * FIXME: It may be fragmented into multiple chunks | |
1218 | * at once if non-fragmentable extension headers | |
1219 | * are too large. | |
1220 | * --yoshfuji | |
1221 | */ | |
1222 | ||
1223 | inet->cork.length += length; | |
1224 | if (((length > mtu) && (sk->sk_protocol == IPPROTO_UDP)) && | |
1225 | (rt->u.dst.dev->features & NETIF_F_UFO)) { | |
1226 | ||
1227 | err = ip6_ufo_append_data(sk, getfrag, from, length, hh_len, | |
1228 | fragheaderlen, transhdrlen, mtu, | |
1229 | flags); | |
1230 | if (err) | |
1231 | goto error; | |
1232 | return 0; | |
1233 | } | |
1234 | ||
1235 | if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) | |
1236 | goto alloc_new_skb; | |
1237 | ||
1238 | while (length > 0) { | |
1239 | /* Check if the remaining data fits into current packet. */ | |
1240 | copy = (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len; | |
1241 | if (copy < length) | |
1242 | copy = maxfraglen - skb->len; | |
1243 | ||
1244 | if (copy <= 0) { | |
1245 | char *data; | |
1246 | unsigned int datalen; | |
1247 | unsigned int fraglen; | |
1248 | unsigned int fraggap; | |
1249 | unsigned int alloclen; | |
1250 | struct sk_buff *skb_prev; | |
1251 | alloc_new_skb: | |
1252 | skb_prev = skb; | |
1253 | ||
1254 | /* There's no room in the current skb */ | |
1255 | if (skb_prev) | |
1256 | fraggap = skb_prev->len - maxfraglen; | |
1257 | else | |
1258 | fraggap = 0; | |
1259 | ||
1260 | /* | |
1261 | * If remaining data exceeds the mtu, | |
1262 | * we know we need more fragment(s). | |
1263 | */ | |
1264 | datalen = length + fraggap; | |
1265 | if (datalen > (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen) | |
1266 | datalen = maxfraglen - fragheaderlen; | |
1267 | ||
1268 | fraglen = datalen + fragheaderlen; | |
1269 | if ((flags & MSG_MORE) && | |
1270 | !(rt->u.dst.dev->features&NETIF_F_SG)) | |
1271 | alloclen = mtu; | |
1272 | else | |
1273 | alloclen = datalen + fragheaderlen; | |
1274 | ||
1275 | /* | |
1276 | * The last fragment gets additional space at tail. | |
1277 | * Note: we overallocate on fragments with MSG_MODE | |
1278 | * because we have no idea if we're the last one. | |
1279 | */ | |
1280 | if (datalen == length + fraggap) | |
1281 | alloclen += rt->u.dst.trailer_len; | |
1282 | ||
1283 | /* | |
1284 | * We just reserve space for fragment header. | |
1285 | * Note: this may be overallocation if the message | |
1286 | * (without MSG_MORE) fits into the MTU. | |
1287 | */ | |
1288 | alloclen += sizeof(struct frag_hdr); | |
1289 | ||
1290 | if (transhdrlen) { | |
1291 | skb = sock_alloc_send_skb(sk, | |
1292 | alloclen + hh_len, | |
1293 | (flags & MSG_DONTWAIT), &err); | |
1294 | } else { | |
1295 | skb = NULL; | |
1296 | if (atomic_read(&sk->sk_wmem_alloc) <= | |
1297 | 2 * sk->sk_sndbuf) | |
1298 | skb = sock_wmalloc(sk, | |
1299 | alloclen + hh_len, 1, | |
1300 | sk->sk_allocation); | |
1301 | if (unlikely(skb == NULL)) | |
1302 | err = -ENOBUFS; | |
1303 | } | |
1304 | if (skb == NULL) | |
1305 | goto error; | |
1306 | /* | |
1307 | * Fill in the control structures | |
1308 | */ | |
1309 | skb->ip_summed = csummode; | |
1310 | skb->csum = 0; | |
1311 | /* reserve for fragmentation */ | |
1312 | skb_reserve(skb, hh_len+sizeof(struct frag_hdr)); | |
1313 | ||
1314 | /* | |
1315 | * Find where to start putting bytes | |
1316 | */ | |
1317 | data = skb_put(skb, fraglen); | |
1318 | skb_set_network_header(skb, exthdrlen); | |
1319 | data += fragheaderlen; | |
1320 | skb->transport_header = (skb->network_header + | |
1321 | fragheaderlen); | |
1322 | if (fraggap) { | |
1323 | skb->csum = skb_copy_and_csum_bits( | |
1324 | skb_prev, maxfraglen, | |
1325 | data + transhdrlen, fraggap, 0); | |
1326 | skb_prev->csum = csum_sub(skb_prev->csum, | |
1327 | skb->csum); | |
1328 | data += fraggap; | |
1329 | pskb_trim_unique(skb_prev, maxfraglen); | |
1330 | } | |
1331 | copy = datalen - transhdrlen - fraggap; | |
1332 | if (copy < 0) { | |
1333 | err = -EINVAL; | |
1334 | kfree_skb(skb); | |
1335 | goto error; | |
1336 | } else if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) { | |
1337 | err = -EFAULT; | |
1338 | kfree_skb(skb); | |
1339 | goto error; | |
1340 | } | |
1341 | ||
1342 | offset += copy; | |
1343 | length -= datalen - fraggap; | |
1344 | transhdrlen = 0; | |
1345 | exthdrlen = 0; | |
1346 | csummode = CHECKSUM_NONE; | |
1347 | ||
1348 | /* | |
1349 | * Put the packet on the pending queue | |
1350 | */ | |
1351 | __skb_queue_tail(&sk->sk_write_queue, skb); | |
1352 | continue; | |
1353 | } | |
1354 | ||
1355 | if (copy > length) | |
1356 | copy = length; | |
1357 | ||
1358 | if (!(rt->u.dst.dev->features&NETIF_F_SG)) { | |
1359 | unsigned int off; | |
1360 | ||
1361 | off = skb->len; | |
1362 | if (getfrag(from, skb_put(skb, copy), | |
1363 | offset, copy, off, skb) < 0) { | |
1364 | __skb_trim(skb, off); | |
1365 | err = -EFAULT; | |
1366 | goto error; | |
1367 | } | |
1368 | } else { | |
1369 | int i = skb_shinfo(skb)->nr_frags; | |
1370 | skb_frag_t *frag = &skb_shinfo(skb)->frags[i-1]; | |
1371 | struct page *page = sk->sk_sndmsg_page; | |
1372 | int off = sk->sk_sndmsg_off; | |
1373 | unsigned int left; | |
1374 | ||
1375 | if (page && (left = PAGE_SIZE - off) > 0) { | |
1376 | if (copy >= left) | |
1377 | copy = left; | |
1378 | if (page != frag->page) { | |
1379 | if (i == MAX_SKB_FRAGS) { | |
1380 | err = -EMSGSIZE; | |
1381 | goto error; | |
1382 | } | |
1383 | get_page(page); | |
1384 | skb_fill_page_desc(skb, i, page, sk->sk_sndmsg_off, 0); | |
1385 | frag = &skb_shinfo(skb)->frags[i]; | |
1386 | } | |
1387 | } else if(i < MAX_SKB_FRAGS) { | |
1388 | if (copy > PAGE_SIZE) | |
1389 | copy = PAGE_SIZE; | |
1390 | page = alloc_pages(sk->sk_allocation, 0); | |
1391 | if (page == NULL) { | |
1392 | err = -ENOMEM; | |
1393 | goto error; | |
1394 | } | |
1395 | sk->sk_sndmsg_page = page; | |
1396 | sk->sk_sndmsg_off = 0; | |
1397 | ||
1398 | skb_fill_page_desc(skb, i, page, 0, 0); | |
1399 | frag = &skb_shinfo(skb)->frags[i]; | |
1400 | } else { | |
1401 | err = -EMSGSIZE; | |
1402 | goto error; | |
1403 | } | |
1404 | if (getfrag(from, page_address(frag->page)+frag->page_offset+frag->size, offset, copy, skb->len, skb) < 0) { | |
1405 | err = -EFAULT; | |
1406 | goto error; | |
1407 | } | |
1408 | sk->sk_sndmsg_off += copy; | |
1409 | frag->size += copy; | |
1410 | skb->len += copy; | |
1411 | skb->data_len += copy; | |
1412 | skb->truesize += copy; | |
1413 | atomic_add(copy, &sk->sk_wmem_alloc); | |
1414 | } | |
1415 | offset += copy; | |
1416 | length -= copy; | |
1417 | } | |
1418 | return 0; | |
1419 | error: | |
1420 | inet->cork.length -= length; | |
1421 | IP6_INC_STATS(sock_net(sk), rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS); | |
1422 | return err; | |
1423 | } | |
1424 | ||
1425 | static void ip6_cork_release(struct inet_sock *inet, struct ipv6_pinfo *np) | |
1426 | { | |
1427 | if (np->cork.opt) { | |
1428 | kfree(np->cork.opt->dst0opt); | |
1429 | kfree(np->cork.opt->dst1opt); | |
1430 | kfree(np->cork.opt->hopopt); | |
1431 | kfree(np->cork.opt->srcrt); | |
1432 | kfree(np->cork.opt); | |
1433 | np->cork.opt = NULL; | |
1434 | } | |
1435 | ||
1436 | if (inet->cork.dst) { | |
1437 | dst_release(inet->cork.dst); | |
1438 | inet->cork.dst = NULL; | |
1439 | inet->cork.flags &= ~IPCORK_ALLFRAG; | |
1440 | } | |
1441 | memset(&inet->cork.fl, 0, sizeof(inet->cork.fl)); | |
1442 | } | |
1443 | ||
1444 | int ip6_push_pending_frames(struct sock *sk) | |
1445 | { | |
1446 | struct sk_buff *skb, *tmp_skb; | |
1447 | struct sk_buff **tail_skb; | |
1448 | struct in6_addr final_dst_buf, *final_dst = &final_dst_buf; | |
1449 | struct inet_sock *inet = inet_sk(sk); | |
1450 | struct ipv6_pinfo *np = inet6_sk(sk); | |
1451 | struct net *net = sock_net(sk); | |
1452 | struct ipv6hdr *hdr; | |
1453 | struct ipv6_txoptions *opt = np->cork.opt; | |
1454 | struct rt6_info *rt = (struct rt6_info *)inet->cork.dst; | |
1455 | struct flowi *fl = &inet->cork.fl; | |
1456 | unsigned char proto = fl->proto; | |
1457 | int err = 0; | |
1458 | ||
1459 | if ((skb = __skb_dequeue(&sk->sk_write_queue)) == NULL) | |
1460 | goto out; | |
1461 | tail_skb = &(skb_shinfo(skb)->frag_list); | |
1462 | ||
1463 | /* move skb->data to ip header from ext header */ | |
1464 | if (skb->data < skb_network_header(skb)) | |
1465 | __skb_pull(skb, skb_network_offset(skb)); | |
1466 | while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) { | |
1467 | __skb_pull(tmp_skb, skb_network_header_len(skb)); | |
1468 | *tail_skb = tmp_skb; | |
1469 | tail_skb = &(tmp_skb->next); | |
1470 | skb->len += tmp_skb->len; | |
1471 | skb->data_len += tmp_skb->len; | |
1472 | skb->truesize += tmp_skb->truesize; | |
1473 | tmp_skb->destructor = NULL; | |
1474 | tmp_skb->sk = NULL; | |
1475 | } | |
1476 | ||
1477 | /* Allow local fragmentation. */ | |
1478 | if (np->pmtudisc < IPV6_PMTUDISC_DO) | |
1479 | skb->local_df = 1; | |
1480 | ||
1481 | ipv6_addr_copy(final_dst, &fl->fl6_dst); | |
1482 | __skb_pull(skb, skb_network_header_len(skb)); | |
1483 | if (opt && opt->opt_flen) | |
1484 | ipv6_push_frag_opts(skb, opt, &proto); | |
1485 | if (opt && opt->opt_nflen) | |
1486 | ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst); | |
1487 | ||
1488 | skb_push(skb, sizeof(struct ipv6hdr)); | |
1489 | skb_reset_network_header(skb); | |
1490 | hdr = ipv6_hdr(skb); | |
1491 | ||
1492 | *(__be32*)hdr = fl->fl6_flowlabel | | |
1493 | htonl(0x60000000 | ((int)np->cork.tclass << 20)); | |
1494 | ||
1495 | hdr->hop_limit = np->cork.hop_limit; | |
1496 | hdr->nexthdr = proto; | |
1497 | ipv6_addr_copy(&hdr->saddr, &fl->fl6_src); | |
1498 | ipv6_addr_copy(&hdr->daddr, final_dst); | |
1499 | ||
1500 | skb->priority = sk->sk_priority; | |
1501 | skb->mark = sk->sk_mark; | |
1502 | ||
1503 | skb_dst_set(skb, dst_clone(&rt->u.dst)); | |
1504 | IP6_UPD_PO_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUT, skb->len); | |
1505 | if (proto == IPPROTO_ICMPV6) { | |
1506 | struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); | |
1507 | ||
1508 | ICMP6MSGOUT_INC_STATS_BH(net, idev, icmp6_hdr(skb)->icmp6_type); | |
1509 | ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTMSGS); | |
1510 | } | |
1511 | ||
1512 | err = ip6_local_out(skb); | |
1513 | if (err) { | |
1514 | if (err > 0) | |
1515 | err = net_xmit_errno(err); | |
1516 | if (err) | |
1517 | goto error; | |
1518 | } | |
1519 | ||
1520 | out: | |
1521 | ip6_cork_release(inet, np); | |
1522 | return err; | |
1523 | error: | |
1524 | IP6_INC_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS); | |
1525 | goto out; | |
1526 | } | |
1527 | ||
1528 | void ip6_flush_pending_frames(struct sock *sk) | |
1529 | { | |
1530 | struct sk_buff *skb; | |
1531 | ||
1532 | while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) { | |
1533 | if (skb_dst(skb)) | |
1534 | IP6_INC_STATS(sock_net(sk), ip6_dst_idev(skb_dst(skb)), | |
1535 | IPSTATS_MIB_OUTDISCARDS); | |
1536 | kfree_skb(skb); | |
1537 | } | |
1538 | ||
1539 | ip6_cork_release(inet_sk(sk), inet6_sk(sk)); | |
1540 | } |