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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 | #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_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *)); | |
60 | ||
61 | int __ip6_local_out(struct sk_buff *skb) | |
62 | { | |
63 | int len; | |
64 | ||
65 | len = skb->len - sizeof(struct ipv6hdr); | |
66 | if (len > IPV6_MAXPLEN) | |
67 | len = 0; | |
68 | ipv6_hdr(skb)->payload_len = htons(len); | |
69 | ||
70 | return nf_hook(PF_INET6, NF_INET_LOCAL_OUT, skb, NULL, skb_dst(skb)->dev, | |
71 | dst_output); | |
72 | } | |
73 | ||
74 | int ip6_local_out(struct sk_buff *skb) | |
75 | { | |
76 | int err; | |
77 | ||
78 | err = __ip6_local_out(skb); | |
79 | if (likely(err == 1)) | |
80 | err = dst_output(skb); | |
81 | ||
82 | return err; | |
83 | } | |
84 | EXPORT_SYMBOL_GPL(ip6_local_out); | |
85 | ||
86 | static int ip6_output_finish(struct sk_buff *skb) | |
87 | { | |
88 | struct dst_entry *dst = skb_dst(skb); | |
89 | ||
90 | if (dst->hh) | |
91 | return neigh_hh_output(dst->hh, skb); | |
92 | else if (dst->neighbour) | |
93 | return dst->neighbour->output(skb); | |
94 | ||
95 | IP6_INC_STATS_BH(dev_net(dst->dev), | |
96 | ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES); | |
97 | kfree_skb(skb); | |
98 | return -EINVAL; | |
99 | ||
100 | } | |
101 | ||
102 | /* dev_loopback_xmit for use with netfilter. */ | |
103 | static int ip6_dev_loopback_xmit(struct sk_buff *newskb) | |
104 | { | |
105 | skb_reset_mac_header(newskb); | |
106 | __skb_pull(newskb, skb_network_offset(newskb)); | |
107 | newskb->pkt_type = PACKET_LOOPBACK; | |
108 | newskb->ip_summed = CHECKSUM_UNNECESSARY; | |
109 | WARN_ON(!skb_dst(newskb)); | |
110 | ||
111 | netif_rx_ni(newskb); | |
112 | return 0; | |
113 | } | |
114 | ||
115 | ||
116 | static int ip6_output2(struct sk_buff *skb) | |
117 | { | |
118 | struct dst_entry *dst = skb_dst(skb); | |
119 | struct net_device *dev = dst->dev; | |
120 | ||
121 | skb->protocol = htons(ETH_P_IPV6); | |
122 | skb->dev = dev; | |
123 | ||
124 | if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) { | |
125 | struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); | |
126 | ||
127 | if (!(dev->flags & IFF_LOOPBACK) && sk_mc_loop(skb->sk) && | |
128 | ((mroute6_socket(dev_net(dev)) && | |
129 | !(IP6CB(skb)->flags & IP6SKB_FORWARDED)) || | |
130 | ipv6_chk_mcast_addr(dev, &ipv6_hdr(skb)->daddr, | |
131 | &ipv6_hdr(skb)->saddr))) { | |
132 | struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); | |
133 | ||
134 | /* Do not check for IFF_ALLMULTI; multicast routing | |
135 | is not supported in any case. | |
136 | */ | |
137 | if (newskb) | |
138 | NF_HOOK(PF_INET6, NF_INET_POST_ROUTING, newskb, | |
139 | NULL, newskb->dev, | |
140 | ip6_dev_loopback_xmit); | |
141 | ||
142 | if (ipv6_hdr(skb)->hop_limit == 0) { | |
143 | IP6_INC_STATS(dev_net(dev), idev, | |
144 | IPSTATS_MIB_OUTDISCARDS); | |
145 | kfree_skb(skb); | |
146 | return 0; | |
147 | } | |
148 | } | |
149 | ||
150 | IP6_UPD_PO_STATS(dev_net(dev), idev, IPSTATS_MIB_OUTMCAST, | |
151 | skb->len); | |
152 | } | |
153 | ||
154 | return NF_HOOK(PF_INET6, NF_INET_POST_ROUTING, skb, NULL, skb->dev, | |
155 | ip6_output_finish); | |
156 | } | |
157 | ||
158 | static inline int ip6_skb_dst_mtu(struct sk_buff *skb) | |
159 | { | |
160 | struct ipv6_pinfo *np = skb->sk ? inet6_sk(skb->sk) : NULL; | |
161 | ||
162 | return (np && np->pmtudisc == IPV6_PMTUDISC_PROBE) ? | |
163 | skb_dst(skb)->dev->mtu : dst_mtu(skb_dst(skb)); | |
164 | } | |
165 | ||
166 | int ip6_output(struct sk_buff *skb) | |
167 | { | |
168 | struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); | |
169 | if (unlikely(idev->cnf.disable_ipv6)) { | |
170 | IP6_INC_STATS(dev_net(skb_dst(skb)->dev), idev, | |
171 | IPSTATS_MIB_OUTDISCARDS); | |
172 | kfree_skb(skb); | |
173 | return 0; | |
174 | } | |
175 | ||
176 | if ((skb->len > ip6_skb_dst_mtu(skb) && !skb_is_gso(skb)) || | |
177 | dst_allfrag(skb_dst(skb))) | |
178 | return ip6_fragment(skb, ip6_output2); | |
179 | else | |
180 | return ip6_output2(skb); | |
181 | } | |
182 | ||
183 | /* | |
184 | * xmit an sk_buff (used by TCP, SCTP and DCCP) | |
185 | */ | |
186 | ||
187 | int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl, | |
188 | struct ipv6_txoptions *opt) | |
189 | { | |
190 | struct net *net = sock_net(sk); | |
191 | struct ipv6_pinfo *np = inet6_sk(sk); | |
192 | struct in6_addr *first_hop = &fl->fl6_dst; | |
193 | struct dst_entry *dst = skb_dst(skb); | |
194 | struct ipv6hdr *hdr; | |
195 | u8 proto = fl->proto; | |
196 | int seg_len = skb->len; | |
197 | int hlimit = -1; | |
198 | int tclass = 0; | |
199 | u32 mtu; | |
200 | ||
201 | if (opt) { | |
202 | unsigned int head_room; | |
203 | ||
204 | /* First: exthdrs may take lots of space (~8K for now) | |
205 | MAX_HEADER is not enough. | |
206 | */ | |
207 | head_room = opt->opt_nflen + opt->opt_flen; | |
208 | seg_len += head_room; | |
209 | head_room += sizeof(struct ipv6hdr) + LL_RESERVED_SPACE(dst->dev); | |
210 | ||
211 | if (skb_headroom(skb) < head_room) { | |
212 | struct sk_buff *skb2 = skb_realloc_headroom(skb, head_room); | |
213 | if (skb2 == NULL) { | |
214 | IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), | |
215 | IPSTATS_MIB_OUTDISCARDS); | |
216 | kfree_skb(skb); | |
217 | return -ENOBUFS; | |
218 | } | |
219 | kfree_skb(skb); | |
220 | skb = skb2; | |
221 | if (sk) | |
222 | skb_set_owner_w(skb, sk); | |
223 | } | |
224 | if (opt->opt_flen) | |
225 | ipv6_push_frag_opts(skb, opt, &proto); | |
226 | if (opt->opt_nflen) | |
227 | ipv6_push_nfrag_opts(skb, opt, &proto, &first_hop); | |
228 | } | |
229 | ||
230 | skb_push(skb, sizeof(struct ipv6hdr)); | |
231 | skb_reset_network_header(skb); | |
232 | hdr = ipv6_hdr(skb); | |
233 | ||
234 | /* | |
235 | * Fill in the IPv6 header | |
236 | */ | |
237 | if (np) { | |
238 | tclass = np->tclass; | |
239 | hlimit = np->hop_limit; | |
240 | } | |
241 | if (hlimit < 0) | |
242 | hlimit = ip6_dst_hoplimit(dst); | |
243 | ||
244 | *(__be32 *)hdr = htonl(0x60000000 | (tclass << 20)) | fl->fl6_flowlabel; | |
245 | ||
246 | hdr->payload_len = htons(seg_len); | |
247 | hdr->nexthdr = proto; | |
248 | hdr->hop_limit = hlimit; | |
249 | ||
250 | ipv6_addr_copy(&hdr->saddr, &fl->fl6_src); | |
251 | ipv6_addr_copy(&hdr->daddr, first_hop); | |
252 | ||
253 | skb->priority = sk->sk_priority; | |
254 | skb->mark = sk->sk_mark; | |
255 | ||
256 | mtu = dst_mtu(dst); | |
257 | if ((skb->len <= mtu) || skb->local_df || skb_is_gso(skb)) { | |
258 | IP6_UPD_PO_STATS(net, ip6_dst_idev(skb_dst(skb)), | |
259 | IPSTATS_MIB_OUT, skb->len); | |
260 | return NF_HOOK(PF_INET6, NF_INET_LOCAL_OUT, skb, NULL, dst->dev, | |
261 | dst_output); | |
262 | } | |
263 | ||
264 | if (net_ratelimit()) | |
265 | printk(KERN_DEBUG "IPv6: sending pkt_too_big to self\n"); | |
266 | skb->dev = dst->dev; | |
267 | icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); | |
268 | IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_FRAGFAILS); | |
269 | kfree_skb(skb); | |
270 | return -EMSGSIZE; | |
271 | } | |
272 | ||
273 | EXPORT_SYMBOL(ip6_xmit); | |
274 | ||
275 | /* | |
276 | * To avoid extra problems ND packets are send through this | |
277 | * routine. It's code duplication but I really want to avoid | |
278 | * extra checks since ipv6_build_header is used by TCP (which | |
279 | * is for us performance critical) | |
280 | */ | |
281 | ||
282 | int ip6_nd_hdr(struct sock *sk, struct sk_buff *skb, struct net_device *dev, | |
283 | const struct in6_addr *saddr, const struct in6_addr *daddr, | |
284 | int proto, int len) | |
285 | { | |
286 | struct ipv6_pinfo *np = inet6_sk(sk); | |
287 | struct ipv6hdr *hdr; | |
288 | int totlen; | |
289 | ||
290 | skb->protocol = htons(ETH_P_IPV6); | |
291 | skb->dev = dev; | |
292 | ||
293 | totlen = len + sizeof(struct ipv6hdr); | |
294 | ||
295 | skb_reset_network_header(skb); | |
296 | skb_put(skb, sizeof(struct ipv6hdr)); | |
297 | hdr = ipv6_hdr(skb); | |
298 | ||
299 | *(__be32*)hdr = htonl(0x60000000); | |
300 | ||
301 | hdr->payload_len = htons(len); | |
302 | hdr->nexthdr = proto; | |
303 | hdr->hop_limit = np->hop_limit; | |
304 | ||
305 | ipv6_addr_copy(&hdr->saddr, saddr); | |
306 | ipv6_addr_copy(&hdr->daddr, daddr); | |
307 | ||
308 | return 0; | |
309 | } | |
310 | ||
311 | static int ip6_call_ra_chain(struct sk_buff *skb, int sel) | |
312 | { | |
313 | struct ip6_ra_chain *ra; | |
314 | struct sock *last = NULL; | |
315 | ||
316 | read_lock(&ip6_ra_lock); | |
317 | for (ra = ip6_ra_chain; ra; ra = ra->next) { | |
318 | struct sock *sk = ra->sk; | |
319 | if (sk && ra->sel == sel && | |
320 | (!sk->sk_bound_dev_if || | |
321 | sk->sk_bound_dev_if == skb->dev->ifindex)) { | |
322 | if (last) { | |
323 | struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); | |
324 | if (skb2) | |
325 | rawv6_rcv(last, skb2); | |
326 | } | |
327 | last = sk; | |
328 | } | |
329 | } | |
330 | ||
331 | if (last) { | |
332 | rawv6_rcv(last, skb); | |
333 | read_unlock(&ip6_ra_lock); | |
334 | return 1; | |
335 | } | |
336 | read_unlock(&ip6_ra_lock); | |
337 | return 0; | |
338 | } | |
339 | ||
340 | static int ip6_forward_proxy_check(struct sk_buff *skb) | |
341 | { | |
342 | struct ipv6hdr *hdr = ipv6_hdr(skb); | |
343 | u8 nexthdr = hdr->nexthdr; | |
344 | int offset; | |
345 | ||
346 | if (ipv6_ext_hdr(nexthdr)) { | |
347 | offset = ipv6_skip_exthdr(skb, sizeof(*hdr), &nexthdr); | |
348 | if (offset < 0) | |
349 | return 0; | |
350 | } else | |
351 | offset = sizeof(struct ipv6hdr); | |
352 | ||
353 | if (nexthdr == IPPROTO_ICMPV6) { | |
354 | struct icmp6hdr *icmp6; | |
355 | ||
356 | if (!pskb_may_pull(skb, (skb_network_header(skb) + | |
357 | offset + 1 - skb->data))) | |
358 | return 0; | |
359 | ||
360 | icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset); | |
361 | ||
362 | switch (icmp6->icmp6_type) { | |
363 | case NDISC_ROUTER_SOLICITATION: | |
364 | case NDISC_ROUTER_ADVERTISEMENT: | |
365 | case NDISC_NEIGHBOUR_SOLICITATION: | |
366 | case NDISC_NEIGHBOUR_ADVERTISEMENT: | |
367 | case NDISC_REDIRECT: | |
368 | /* For reaction involving unicast neighbor discovery | |
369 | * message destined to the proxied address, pass it to | |
370 | * input function. | |
371 | */ | |
372 | return 1; | |
373 | default: | |
374 | break; | |
375 | } | |
376 | } | |
377 | ||
378 | /* | |
379 | * The proxying router can't forward traffic sent to a link-local | |
380 | * address, so signal the sender and discard the packet. This | |
381 | * behavior is clarified by the MIPv6 specification. | |
382 | */ | |
383 | if (ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) { | |
384 | dst_link_failure(skb); | |
385 | return -1; | |
386 | } | |
387 | ||
388 | return 0; | |
389 | } | |
390 | ||
391 | static inline int ip6_forward_finish(struct sk_buff *skb) | |
392 | { | |
393 | return dst_output(skb); | |
394 | } | |
395 | ||
396 | int ip6_forward(struct sk_buff *skb) | |
397 | { | |
398 | struct dst_entry *dst = skb_dst(skb); | |
399 | struct ipv6hdr *hdr = ipv6_hdr(skb); | |
400 | struct inet6_skb_parm *opt = IP6CB(skb); | |
401 | struct net *net = dev_net(dst->dev); | |
402 | u32 mtu; | |
403 | ||
404 | if (net->ipv6.devconf_all->forwarding == 0) | |
405 | goto error; | |
406 | ||
407 | if (skb_warn_if_lro(skb)) | |
408 | goto drop; | |
409 | ||
410 | if (!xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) { | |
411 | IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS); | |
412 | goto drop; | |
413 | } | |
414 | ||
415 | skb_forward_csum(skb); | |
416 | ||
417 | /* | |
418 | * We DO NOT make any processing on | |
419 | * RA packets, pushing them to user level AS IS | |
420 | * without ane WARRANTY that application will be able | |
421 | * to interpret them. The reason is that we | |
422 | * cannot make anything clever here. | |
423 | * | |
424 | * We are not end-node, so that if packet contains | |
425 | * AH/ESP, we cannot make anything. | |
426 | * Defragmentation also would be mistake, RA packets | |
427 | * cannot be fragmented, because there is no warranty | |
428 | * that different fragments will go along one path. --ANK | |
429 | */ | |
430 | if (opt->ra) { | |
431 | u8 *ptr = skb_network_header(skb) + opt->ra; | |
432 | if (ip6_call_ra_chain(skb, (ptr[2]<<8) + ptr[3])) | |
433 | return 0; | |
434 | } | |
435 | ||
436 | /* | |
437 | * check and decrement ttl | |
438 | */ | |
439 | if (hdr->hop_limit <= 1) { | |
440 | /* Force OUTPUT device used as source address */ | |
441 | skb->dev = dst->dev; | |
442 | icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 0); | |
443 | IP6_INC_STATS_BH(net, | |
444 | ip6_dst_idev(dst), IPSTATS_MIB_INHDRERRORS); | |
445 | ||
446 | kfree_skb(skb); | |
447 | return -ETIMEDOUT; | |
448 | } | |
449 | ||
450 | /* XXX: idev->cnf.proxy_ndp? */ | |
451 | if (net->ipv6.devconf_all->proxy_ndp && | |
452 | pneigh_lookup(&nd_tbl, net, &hdr->daddr, skb->dev, 0)) { | |
453 | int proxied = ip6_forward_proxy_check(skb); | |
454 | if (proxied > 0) | |
455 | return ip6_input(skb); | |
456 | else if (proxied < 0) { | |
457 | IP6_INC_STATS(net, ip6_dst_idev(dst), | |
458 | IPSTATS_MIB_INDISCARDS); | |
459 | goto drop; | |
460 | } | |
461 | } | |
462 | ||
463 | if (!xfrm6_route_forward(skb)) { | |
464 | IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS); | |
465 | goto drop; | |
466 | } | |
467 | dst = skb_dst(skb); | |
468 | ||
469 | /* IPv6 specs say nothing about it, but it is clear that we cannot | |
470 | send redirects to source routed frames. | |
471 | We don't send redirects to frames decapsulated from IPsec. | |
472 | */ | |
473 | if (skb->dev == dst->dev && dst->neighbour && opt->srcrt == 0 && | |
474 | !skb_sec_path(skb)) { | |
475 | struct in6_addr *target = NULL; | |
476 | struct rt6_info *rt; | |
477 | struct neighbour *n = dst->neighbour; | |
478 | ||
479 | /* | |
480 | * incoming and outgoing devices are the same | |
481 | * send a redirect. | |
482 | */ | |
483 | ||
484 | rt = (struct rt6_info *) dst; | |
485 | if ((rt->rt6i_flags & RTF_GATEWAY)) | |
486 | target = (struct in6_addr*)&n->primary_key; | |
487 | else | |
488 | target = &hdr->daddr; | |
489 | ||
490 | /* Limit redirects both by destination (here) | |
491 | and by source (inside ndisc_send_redirect) | |
492 | */ | |
493 | if (xrlim_allow(dst, 1*HZ)) | |
494 | ndisc_send_redirect(skb, n, target); | |
495 | } else { | |
496 | int addrtype = ipv6_addr_type(&hdr->saddr); | |
497 | ||
498 | /* This check is security critical. */ | |
499 | if (addrtype == IPV6_ADDR_ANY || | |
500 | addrtype & (IPV6_ADDR_MULTICAST | IPV6_ADDR_LOOPBACK)) | |
501 | goto error; | |
502 | if (addrtype & IPV6_ADDR_LINKLOCAL) { | |
503 | icmpv6_send(skb, ICMPV6_DEST_UNREACH, | |
504 | ICMPV6_NOT_NEIGHBOUR, 0); | |
505 | goto error; | |
506 | } | |
507 | } | |
508 | ||
509 | mtu = dst_mtu(dst); | |
510 | if (mtu < IPV6_MIN_MTU) | |
511 | mtu = IPV6_MIN_MTU; | |
512 | ||
513 | if (skb->len > mtu) { | |
514 | /* Again, force OUTPUT device used as source address */ | |
515 | skb->dev = dst->dev; | |
516 | icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); | |
517 | IP6_INC_STATS_BH(net, | |
518 | ip6_dst_idev(dst), IPSTATS_MIB_INTOOBIGERRORS); | |
519 | IP6_INC_STATS_BH(net, | |
520 | ip6_dst_idev(dst), IPSTATS_MIB_FRAGFAILS); | |
521 | kfree_skb(skb); | |
522 | return -EMSGSIZE; | |
523 | } | |
524 | ||
525 | if (skb_cow(skb, dst->dev->hard_header_len)) { | |
526 | IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTDISCARDS); | |
527 | goto drop; | |
528 | } | |
529 | ||
530 | hdr = ipv6_hdr(skb); | |
531 | ||
532 | /* Mangling hops number delayed to point after skb COW */ | |
533 | ||
534 | hdr->hop_limit--; | |
535 | ||
536 | IP6_INC_STATS_BH(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTFORWDATAGRAMS); | |
537 | return NF_HOOK(PF_INET6, NF_INET_FORWARD, skb, skb->dev, dst->dev, | |
538 | ip6_forward_finish); | |
539 | ||
540 | error: | |
541 | IP6_INC_STATS_BH(net, ip6_dst_idev(dst), IPSTATS_MIB_INADDRERRORS); | |
542 | drop: | |
543 | kfree_skb(skb); | |
544 | return -EINVAL; | |
545 | } | |
546 | ||
547 | static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from) | |
548 | { | |
549 | to->pkt_type = from->pkt_type; | |
550 | to->priority = from->priority; | |
551 | to->protocol = from->protocol; | |
552 | skb_dst_drop(to); | |
553 | skb_dst_set(to, dst_clone(skb_dst(from))); | |
554 | to->dev = from->dev; | |
555 | to->mark = from->mark; | |
556 | ||
557 | #ifdef CONFIG_NET_SCHED | |
558 | to->tc_index = from->tc_index; | |
559 | #endif | |
560 | nf_copy(to, from); | |
561 | #if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \ | |
562 | defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE) | |
563 | to->nf_trace = from->nf_trace; | |
564 | #endif | |
565 | skb_copy_secmark(to, from); | |
566 | } | |
567 | ||
568 | int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr) | |
569 | { | |
570 | u16 offset = sizeof(struct ipv6hdr); | |
571 | struct ipv6_opt_hdr *exthdr = | |
572 | (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1); | |
573 | unsigned int packet_len = skb->tail - skb->network_header; | |
574 | int found_rhdr = 0; | |
575 | *nexthdr = &ipv6_hdr(skb)->nexthdr; | |
576 | ||
577 | while (offset + 1 <= packet_len) { | |
578 | ||
579 | switch (**nexthdr) { | |
580 | ||
581 | case NEXTHDR_HOP: | |
582 | break; | |
583 | case NEXTHDR_ROUTING: | |
584 | found_rhdr = 1; | |
585 | break; | |
586 | case NEXTHDR_DEST: | |
587 | #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) | |
588 | if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0) | |
589 | break; | |
590 | #endif | |
591 | if (found_rhdr) | |
592 | return offset; | |
593 | break; | |
594 | default : | |
595 | return offset; | |
596 | } | |
597 | ||
598 | offset += ipv6_optlen(exthdr); | |
599 | *nexthdr = &exthdr->nexthdr; | |
600 | exthdr = (struct ipv6_opt_hdr *)(skb_network_header(skb) + | |
601 | offset); | |
602 | } | |
603 | ||
604 | return offset; | |
605 | } | |
606 | ||
607 | static int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *)) | |
608 | { | |
609 | struct sk_buff *frag; | |
610 | struct rt6_info *rt = (struct rt6_info*)skb_dst(skb); | |
611 | struct ipv6_pinfo *np = skb->sk ? inet6_sk(skb->sk) : NULL; | |
612 | struct ipv6hdr *tmp_hdr; | |
613 | struct frag_hdr *fh; | |
614 | unsigned int mtu, hlen, left, len; | |
615 | __be32 frag_id = 0; | |
616 | int ptr, offset = 0, err=0; | |
617 | u8 *prevhdr, nexthdr = 0; | |
618 | struct net *net = dev_net(skb_dst(skb)->dev); | |
619 | ||
620 | hlen = ip6_find_1stfragopt(skb, &prevhdr); | |
621 | nexthdr = *prevhdr; | |
622 | ||
623 | mtu = ip6_skb_dst_mtu(skb); | |
624 | ||
625 | /* We must not fragment if the socket is set to force MTU discovery | |
626 | * or if the skb it not generated by a local socket. | |
627 | */ | |
628 | if (!skb->local_df) { | |
629 | skb->dev = skb_dst(skb)->dev; | |
630 | icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); | |
631 | IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), | |
632 | IPSTATS_MIB_FRAGFAILS); | |
633 | kfree_skb(skb); | |
634 | return -EMSGSIZE; | |
635 | } | |
636 | ||
637 | if (np && np->frag_size < mtu) { | |
638 | if (np->frag_size) | |
639 | mtu = np->frag_size; | |
640 | } | |
641 | mtu -= hlen + sizeof(struct frag_hdr); | |
642 | ||
643 | if (skb_has_frags(skb)) { | |
644 | int first_len = skb_pagelen(skb); | |
645 | int truesizes = 0; | |
646 | ||
647 | if (first_len - hlen > mtu || | |
648 | ((first_len - hlen) & 7) || | |
649 | skb_cloned(skb)) | |
650 | goto slow_path; | |
651 | ||
652 | skb_walk_frags(skb, frag) { | |
653 | /* Correct geometry. */ | |
654 | if (frag->len > mtu || | |
655 | ((frag->len & 7) && frag->next) || | |
656 | skb_headroom(frag) < hlen) | |
657 | goto slow_path; | |
658 | ||
659 | /* Partially cloned skb? */ | |
660 | if (skb_shared(frag)) | |
661 | goto slow_path; | |
662 | ||
663 | BUG_ON(frag->sk); | |
664 | if (skb->sk) { | |
665 | frag->sk = skb->sk; | |
666 | frag->destructor = sock_wfree; | |
667 | truesizes += frag->truesize; | |
668 | } | |
669 | } | |
670 | ||
671 | err = 0; | |
672 | offset = 0; | |
673 | frag = skb_shinfo(skb)->frag_list; | |
674 | skb_frag_list_init(skb); | |
675 | /* BUILD HEADER */ | |
676 | ||
677 | *prevhdr = NEXTHDR_FRAGMENT; | |
678 | tmp_hdr = kmemdup(skb_network_header(skb), hlen, GFP_ATOMIC); | |
679 | if (!tmp_hdr) { | |
680 | IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), | |
681 | IPSTATS_MIB_FRAGFAILS); | |
682 | return -ENOMEM; | |
683 | } | |
684 | ||
685 | __skb_pull(skb, hlen); | |
686 | fh = (struct frag_hdr*)__skb_push(skb, sizeof(struct frag_hdr)); | |
687 | __skb_push(skb, hlen); | |
688 | skb_reset_network_header(skb); | |
689 | memcpy(skb_network_header(skb), tmp_hdr, hlen); | |
690 | ||
691 | ipv6_select_ident(fh); | |
692 | fh->nexthdr = nexthdr; | |
693 | fh->reserved = 0; | |
694 | fh->frag_off = htons(IP6_MF); | |
695 | frag_id = fh->identification; | |
696 | ||
697 | first_len = skb_pagelen(skb); | |
698 | skb->data_len = first_len - skb_headlen(skb); | |
699 | skb->truesize -= truesizes; | |
700 | skb->len = first_len; | |
701 | ipv6_hdr(skb)->payload_len = htons(first_len - | |
702 | sizeof(struct ipv6hdr)); | |
703 | ||
704 | dst_hold(&rt->u.dst); | |
705 | ||
706 | for (;;) { | |
707 | /* Prepare header of the next frame, | |
708 | * before previous one went down. */ | |
709 | if (frag) { | |
710 | frag->ip_summed = CHECKSUM_NONE; | |
711 | skb_reset_transport_header(frag); | |
712 | fh = (struct frag_hdr*)__skb_push(frag, sizeof(struct frag_hdr)); | |
713 | __skb_push(frag, hlen); | |
714 | skb_reset_network_header(frag); | |
715 | memcpy(skb_network_header(frag), tmp_hdr, | |
716 | hlen); | |
717 | offset += skb->len - hlen - sizeof(struct frag_hdr); | |
718 | fh->nexthdr = nexthdr; | |
719 | fh->reserved = 0; | |
720 | fh->frag_off = htons(offset); | |
721 | if (frag->next != NULL) | |
722 | fh->frag_off |= htons(IP6_MF); | |
723 | fh->identification = frag_id; | |
724 | ipv6_hdr(frag)->payload_len = | |
725 | htons(frag->len - | |
726 | sizeof(struct ipv6hdr)); | |
727 | ip6_copy_metadata(frag, skb); | |
728 | } | |
729 | ||
730 | err = output(skb); | |
731 | if(!err) | |
732 | IP6_INC_STATS(net, ip6_dst_idev(&rt->u.dst), | |
733 | IPSTATS_MIB_FRAGCREATES); | |
734 | ||
735 | if (err || !frag) | |
736 | break; | |
737 | ||
738 | skb = frag; | |
739 | frag = skb->next; | |
740 | skb->next = NULL; | |
741 | } | |
742 | ||
743 | kfree(tmp_hdr); | |
744 | ||
745 | if (err == 0) { | |
746 | IP6_INC_STATS(net, ip6_dst_idev(&rt->u.dst), | |
747 | IPSTATS_MIB_FRAGOKS); | |
748 | dst_release(&rt->u.dst); | |
749 | return 0; | |
750 | } | |
751 | ||
752 | while (frag) { | |
753 | skb = frag->next; | |
754 | kfree_skb(frag); | |
755 | frag = skb; | |
756 | } | |
757 | ||
758 | IP6_INC_STATS(net, ip6_dst_idev(&rt->u.dst), | |
759 | IPSTATS_MIB_FRAGFAILS); | |
760 | dst_release(&rt->u.dst); | |
761 | return err; | |
762 | } | |
763 | ||
764 | slow_path: | |
765 | left = skb->len - hlen; /* Space per frame */ | |
766 | ptr = hlen; /* Where to start from */ | |
767 | ||
768 | /* | |
769 | * Fragment the datagram. | |
770 | */ | |
771 | ||
772 | *prevhdr = NEXTHDR_FRAGMENT; | |
773 | ||
774 | /* | |
775 | * Keep copying data until we run out. | |
776 | */ | |
777 | while(left > 0) { | |
778 | len = left; | |
779 | /* IF: it doesn't fit, use 'mtu' - the data space left */ | |
780 | if (len > mtu) | |
781 | len = mtu; | |
782 | /* IF: we are not sending upto and including the packet end | |
783 | then align the next start on an eight byte boundary */ | |
784 | if (len < left) { | |
785 | len &= ~7; | |
786 | } | |
787 | /* | |
788 | * Allocate buffer. | |
789 | */ | |
790 | ||
791 | if ((frag = alloc_skb(len+hlen+sizeof(struct frag_hdr)+LL_ALLOCATED_SPACE(rt->u.dst.dev), GFP_ATOMIC)) == NULL) { | |
792 | NETDEBUG(KERN_INFO "IPv6: frag: no memory for new fragment!\n"); | |
793 | IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), | |
794 | IPSTATS_MIB_FRAGFAILS); | |
795 | err = -ENOMEM; | |
796 | goto fail; | |
797 | } | |
798 | ||
799 | /* | |
800 | * Set up data on packet | |
801 | */ | |
802 | ||
803 | ip6_copy_metadata(frag, skb); | |
804 | skb_reserve(frag, LL_RESERVED_SPACE(rt->u.dst.dev)); | |
805 | skb_put(frag, len + hlen + sizeof(struct frag_hdr)); | |
806 | skb_reset_network_header(frag); | |
807 | fh = (struct frag_hdr *)(skb_network_header(frag) + hlen); | |
808 | frag->transport_header = (frag->network_header + hlen + | |
809 | sizeof(struct frag_hdr)); | |
810 | ||
811 | /* | |
812 | * Charge the memory for the fragment to any owner | |
813 | * it might possess | |
814 | */ | |
815 | if (skb->sk) | |
816 | skb_set_owner_w(frag, skb->sk); | |
817 | ||
818 | /* | |
819 | * Copy the packet header into the new buffer. | |
820 | */ | |
821 | skb_copy_from_linear_data(skb, skb_network_header(frag), hlen); | |
822 | ||
823 | /* | |
824 | * Build fragment header. | |
825 | */ | |
826 | fh->nexthdr = nexthdr; | |
827 | fh->reserved = 0; | |
828 | if (!frag_id) { | |
829 | ipv6_select_ident(fh); | |
830 | frag_id = fh->identification; | |
831 | } else | |
832 | fh->identification = frag_id; | |
833 | ||
834 | /* | |
835 | * Copy a block of the IP datagram. | |
836 | */ | |
837 | if (skb_copy_bits(skb, ptr, skb_transport_header(frag), len)) | |
838 | BUG(); | |
839 | left -= len; | |
840 | ||
841 | fh->frag_off = htons(offset); | |
842 | if (left > 0) | |
843 | fh->frag_off |= htons(IP6_MF); | |
844 | ipv6_hdr(frag)->payload_len = htons(frag->len - | |
845 | sizeof(struct ipv6hdr)); | |
846 | ||
847 | ptr += len; | |
848 | offset += len; | |
849 | ||
850 | /* | |
851 | * Put this fragment into the sending queue. | |
852 | */ | |
853 | err = output(frag); | |
854 | if (err) | |
855 | goto fail; | |
856 | ||
857 | IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), | |
858 | IPSTATS_MIB_FRAGCREATES); | |
859 | } | |
860 | IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), | |
861 | IPSTATS_MIB_FRAGOKS); | |
862 | kfree_skb(skb); | |
863 | return err; | |
864 | ||
865 | fail: | |
866 | IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), | |
867 | IPSTATS_MIB_FRAGFAILS); | |
868 | kfree_skb(skb); | |
869 | return err; | |
870 | } | |
871 | ||
872 | static inline int ip6_rt_check(struct rt6key *rt_key, | |
873 | struct in6_addr *fl_addr, | |
874 | struct in6_addr *addr_cache) | |
875 | { | |
876 | return ((rt_key->plen != 128 || !ipv6_addr_equal(fl_addr, &rt_key->addr)) && | |
877 | (addr_cache == NULL || !ipv6_addr_equal(fl_addr, addr_cache))); | |
878 | } | |
879 | ||
880 | static struct dst_entry *ip6_sk_dst_check(struct sock *sk, | |
881 | struct dst_entry *dst, | |
882 | struct flowi *fl) | |
883 | { | |
884 | struct ipv6_pinfo *np = inet6_sk(sk); | |
885 | struct rt6_info *rt = (struct rt6_info *)dst; | |
886 | ||
887 | if (!dst) | |
888 | goto out; | |
889 | ||
890 | /* Yes, checking route validity in not connected | |
891 | * case is not very simple. Take into account, | |
892 | * that we do not support routing by source, TOS, | |
893 | * and MSG_DONTROUTE --ANK (980726) | |
894 | * | |
895 | * 1. ip6_rt_check(): If route was host route, | |
896 | * check that cached destination is current. | |
897 | * If it is network route, we still may | |
898 | * check its validity using saved pointer | |
899 | * to the last used address: daddr_cache. | |
900 | * We do not want to save whole address now, | |
901 | * (because main consumer of this service | |
902 | * is tcp, which has not this problem), | |
903 | * so that the last trick works only on connected | |
904 | * sockets. | |
905 | * 2. oif also should be the same. | |
906 | */ | |
907 | if (ip6_rt_check(&rt->rt6i_dst, &fl->fl6_dst, np->daddr_cache) || | |
908 | #ifdef CONFIG_IPV6_SUBTREES | |
909 | ip6_rt_check(&rt->rt6i_src, &fl->fl6_src, np->saddr_cache) || | |
910 | #endif | |
911 | (fl->oif && fl->oif != dst->dev->ifindex)) { | |
912 | dst_release(dst); | |
913 | dst = NULL; | |
914 | } | |
915 | ||
916 | out: | |
917 | return dst; | |
918 | } | |
919 | ||
920 | static int ip6_dst_lookup_tail(struct sock *sk, | |
921 | struct dst_entry **dst, struct flowi *fl) | |
922 | { | |
923 | int err; | |
924 | struct net *net = sock_net(sk); | |
925 | ||
926 | if (*dst == NULL) | |
927 | *dst = ip6_route_output(net, sk, fl); | |
928 | ||
929 | if ((err = (*dst)->error)) | |
930 | goto out_err_release; | |
931 | ||
932 | if (ipv6_addr_any(&fl->fl6_src)) { | |
933 | err = ipv6_dev_get_saddr(net, ip6_dst_idev(*dst)->dev, | |
934 | &fl->fl6_dst, | |
935 | sk ? inet6_sk(sk)->srcprefs : 0, | |
936 | &fl->fl6_src); | |
937 | if (err) | |
938 | goto out_err_release; | |
939 | } | |
940 | ||
941 | #ifdef CONFIG_IPV6_OPTIMISTIC_DAD | |
942 | /* | |
943 | * Here if the dst entry we've looked up | |
944 | * has a neighbour entry that is in the INCOMPLETE | |
945 | * state and the src address from the flow is | |
946 | * marked as OPTIMISTIC, we release the found | |
947 | * dst entry and replace it instead with the | |
948 | * dst entry of the nexthop router | |
949 | */ | |
950 | if ((*dst)->neighbour && !((*dst)->neighbour->nud_state & NUD_VALID)) { | |
951 | struct inet6_ifaddr *ifp; | |
952 | struct flowi fl_gw; | |
953 | int redirect; | |
954 | ||
955 | ifp = ipv6_get_ifaddr(net, &fl->fl6_src, | |
956 | (*dst)->dev, 1); | |
957 | ||
958 | redirect = (ifp && ifp->flags & IFA_F_OPTIMISTIC); | |
959 | if (ifp) | |
960 | in6_ifa_put(ifp); | |
961 | ||
962 | if (redirect) { | |
963 | /* | |
964 | * We need to get the dst entry for the | |
965 | * default router instead | |
966 | */ | |
967 | dst_release(*dst); | |
968 | memcpy(&fl_gw, fl, sizeof(struct flowi)); | |
969 | memset(&fl_gw.fl6_dst, 0, sizeof(struct in6_addr)); | |
970 | *dst = ip6_route_output(net, sk, &fl_gw); | |
971 | if ((err = (*dst)->error)) | |
972 | goto out_err_release; | |
973 | } | |
974 | } | |
975 | #endif | |
976 | ||
977 | return 0; | |
978 | ||
979 | out_err_release: | |
980 | if (err == -ENETUNREACH) | |
981 | IP6_INC_STATS_BH(net, NULL, IPSTATS_MIB_OUTNOROUTES); | |
982 | dst_release(*dst); | |
983 | *dst = NULL; | |
984 | return err; | |
985 | } | |
986 | ||
987 | /** | |
988 | * ip6_dst_lookup - perform route lookup on flow | |
989 | * @sk: socket which provides route info | |
990 | * @dst: pointer to dst_entry * for result | |
991 | * @fl: flow to lookup | |
992 | * | |
993 | * This function performs a route lookup on the given flow. | |
994 | * | |
995 | * It returns zero on success, or a standard errno code on error. | |
996 | */ | |
997 | int ip6_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi *fl) | |
998 | { | |
999 | *dst = NULL; | |
1000 | return ip6_dst_lookup_tail(sk, dst, fl); | |
1001 | } | |
1002 | EXPORT_SYMBOL_GPL(ip6_dst_lookup); | |
1003 | ||
1004 | /** | |
1005 | * ip6_sk_dst_lookup - perform socket cached route lookup on flow | |
1006 | * @sk: socket which provides the dst cache and route info | |
1007 | * @dst: pointer to dst_entry * for result | |
1008 | * @fl: flow to lookup | |
1009 | * | |
1010 | * This function performs a route lookup on the given flow with the | |
1011 | * possibility of using the cached route in the socket if it is valid. | |
1012 | * It will take the socket dst lock when operating on the dst cache. | |
1013 | * As a result, this function can only be used in process context. | |
1014 | * | |
1015 | * It returns zero on success, or a standard errno code on error. | |
1016 | */ | |
1017 | int ip6_sk_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi *fl) | |
1018 | { | |
1019 | *dst = NULL; | |
1020 | if (sk) { | |
1021 | *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie); | |
1022 | *dst = ip6_sk_dst_check(sk, *dst, fl); | |
1023 | } | |
1024 | ||
1025 | return ip6_dst_lookup_tail(sk, dst, fl); | |
1026 | } | |
1027 | EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup); | |
1028 | ||
1029 | static inline int ip6_ufo_append_data(struct sock *sk, | |
1030 | int getfrag(void *from, char *to, int offset, int len, | |
1031 | int odd, struct sk_buff *skb), | |
1032 | void *from, int length, int hh_len, int fragheaderlen, | |
1033 | int transhdrlen, int mtu,unsigned int flags) | |
1034 | ||
1035 | { | |
1036 | struct sk_buff *skb; | |
1037 | int err; | |
1038 | ||
1039 | /* There is support for UDP large send offload by network | |
1040 | * device, so create one single skb packet containing complete | |
1041 | * udp datagram | |
1042 | */ | |
1043 | if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) { | |
1044 | skb = sock_alloc_send_skb(sk, | |
1045 | hh_len + fragheaderlen + transhdrlen + 20, | |
1046 | (flags & MSG_DONTWAIT), &err); | |
1047 | if (skb == NULL) | |
1048 | return -ENOMEM; | |
1049 | ||
1050 | /* reserve space for Hardware header */ | |
1051 | skb_reserve(skb, hh_len); | |
1052 | ||
1053 | /* create space for UDP/IP header */ | |
1054 | skb_put(skb,fragheaderlen + transhdrlen); | |
1055 | ||
1056 | /* initialize network header pointer */ | |
1057 | skb_reset_network_header(skb); | |
1058 | ||
1059 | /* initialize protocol header pointer */ | |
1060 | skb->transport_header = skb->network_header + fragheaderlen; | |
1061 | ||
1062 | skb->ip_summed = CHECKSUM_PARTIAL; | |
1063 | skb->csum = 0; | |
1064 | sk->sk_sndmsg_off = 0; | |
1065 | } | |
1066 | ||
1067 | err = skb_append_datato_frags(sk,skb, getfrag, from, | |
1068 | (length - transhdrlen)); | |
1069 | if (!err) { | |
1070 | struct frag_hdr fhdr; | |
1071 | ||
1072 | /* Specify the length of each IPv6 datagram fragment. | |
1073 | * It has to be a multiple of 8. | |
1074 | */ | |
1075 | skb_shinfo(skb)->gso_size = (mtu - fragheaderlen - | |
1076 | sizeof(struct frag_hdr)) & ~7; | |
1077 | skb_shinfo(skb)->gso_type = SKB_GSO_UDP; | |
1078 | ipv6_select_ident(&fhdr); | |
1079 | skb_shinfo(skb)->ip6_frag_id = fhdr.identification; | |
1080 | __skb_queue_tail(&sk->sk_write_queue, skb); | |
1081 | ||
1082 | return 0; | |
1083 | } | |
1084 | /* There is not enough support do UPD LSO, | |
1085 | * so follow normal path | |
1086 | */ | |
1087 | kfree_skb(skb); | |
1088 | ||
1089 | return err; | |
1090 | } | |
1091 | ||
1092 | static inline struct ipv6_opt_hdr *ip6_opt_dup(struct ipv6_opt_hdr *src, | |
1093 | gfp_t gfp) | |
1094 | { | |
1095 | return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL; | |
1096 | } | |
1097 | ||
1098 | static inline struct ipv6_rt_hdr *ip6_rthdr_dup(struct ipv6_rt_hdr *src, | |
1099 | gfp_t gfp) | |
1100 | { | |
1101 | return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL; | |
1102 | } | |
1103 | ||
1104 | int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to, | |
1105 | int offset, int len, int odd, struct sk_buff *skb), | |
1106 | void *from, int length, int transhdrlen, | |
1107 | int hlimit, int tclass, struct ipv6_txoptions *opt, struct flowi *fl, | |
1108 | struct rt6_info *rt, unsigned int flags, int dontfrag) | |
1109 | { | |
1110 | struct inet_sock *inet = inet_sk(sk); | |
1111 | struct ipv6_pinfo *np = inet6_sk(sk); | |
1112 | struct sk_buff *skb; | |
1113 | unsigned int maxfraglen, fragheaderlen; | |
1114 | int exthdrlen; | |
1115 | int hh_len; | |
1116 | int mtu; | |
1117 | int copy; | |
1118 | int err; | |
1119 | int offset = 0; | |
1120 | int csummode = CHECKSUM_NONE; | |
1121 | ||
1122 | if (flags&MSG_PROBE) | |
1123 | return 0; | |
1124 | if (skb_queue_empty(&sk->sk_write_queue)) { | |
1125 | /* | |
1126 | * setup for corking | |
1127 | */ | |
1128 | if (opt) { | |
1129 | if (WARN_ON(np->cork.opt)) | |
1130 | return -EINVAL; | |
1131 | ||
1132 | np->cork.opt = kmalloc(opt->tot_len, sk->sk_allocation); | |
1133 | if (unlikely(np->cork.opt == NULL)) | |
1134 | return -ENOBUFS; | |
1135 | ||
1136 | np->cork.opt->tot_len = opt->tot_len; | |
1137 | np->cork.opt->opt_flen = opt->opt_flen; | |
1138 | np->cork.opt->opt_nflen = opt->opt_nflen; | |
1139 | ||
1140 | np->cork.opt->dst0opt = ip6_opt_dup(opt->dst0opt, | |
1141 | sk->sk_allocation); | |
1142 | if (opt->dst0opt && !np->cork.opt->dst0opt) | |
1143 | return -ENOBUFS; | |
1144 | ||
1145 | np->cork.opt->dst1opt = ip6_opt_dup(opt->dst1opt, | |
1146 | sk->sk_allocation); | |
1147 | if (opt->dst1opt && !np->cork.opt->dst1opt) | |
1148 | return -ENOBUFS; | |
1149 | ||
1150 | np->cork.opt->hopopt = ip6_opt_dup(opt->hopopt, | |
1151 | sk->sk_allocation); | |
1152 | if (opt->hopopt && !np->cork.opt->hopopt) | |
1153 | return -ENOBUFS; | |
1154 | ||
1155 | np->cork.opt->srcrt = ip6_rthdr_dup(opt->srcrt, | |
1156 | sk->sk_allocation); | |
1157 | if (opt->srcrt && !np->cork.opt->srcrt) | |
1158 | return -ENOBUFS; | |
1159 | ||
1160 | /* need source address above miyazawa*/ | |
1161 | } | |
1162 | dst_hold(&rt->u.dst); | |
1163 | inet->cork.dst = &rt->u.dst; | |
1164 | inet->cork.fl = *fl; | |
1165 | np->cork.hop_limit = hlimit; | |
1166 | np->cork.tclass = tclass; | |
1167 | mtu = np->pmtudisc == IPV6_PMTUDISC_PROBE ? | |
1168 | rt->u.dst.dev->mtu : dst_mtu(rt->u.dst.path); | |
1169 | if (np->frag_size < mtu) { | |
1170 | if (np->frag_size) | |
1171 | mtu = np->frag_size; | |
1172 | } | |
1173 | inet->cork.fragsize = mtu; | |
1174 | if (dst_allfrag(rt->u.dst.path)) | |
1175 | inet->cork.flags |= IPCORK_ALLFRAG; | |
1176 | inet->cork.length = 0; | |
1177 | sk->sk_sndmsg_page = NULL; | |
1178 | sk->sk_sndmsg_off = 0; | |
1179 | exthdrlen = rt->u.dst.header_len + (opt ? opt->opt_flen : 0) - | |
1180 | rt->rt6i_nfheader_len; | |
1181 | length += exthdrlen; | |
1182 | transhdrlen += exthdrlen; | |
1183 | } else { | |
1184 | rt = (struct rt6_info *)inet->cork.dst; | |
1185 | fl = &inet->cork.fl; | |
1186 | opt = np->cork.opt; | |
1187 | transhdrlen = 0; | |
1188 | exthdrlen = 0; | |
1189 | mtu = inet->cork.fragsize; | |
1190 | } | |
1191 | ||
1192 | hh_len = LL_RESERVED_SPACE(rt->u.dst.dev); | |
1193 | ||
1194 | fragheaderlen = sizeof(struct ipv6hdr) + rt->rt6i_nfheader_len + | |
1195 | (opt ? opt->opt_nflen : 0); | |
1196 | maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - sizeof(struct frag_hdr); | |
1197 | ||
1198 | if (mtu <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN) { | |
1199 | if (inet->cork.length + length > sizeof(struct ipv6hdr) + IPV6_MAXPLEN - fragheaderlen) { | |
1200 | ipv6_local_error(sk, EMSGSIZE, fl, mtu-exthdrlen); | |
1201 | return -EMSGSIZE; | |
1202 | } | |
1203 | } | |
1204 | ||
1205 | /* | |
1206 | * Let's try using as much space as possible. | |
1207 | * Use MTU if total length of the message fits into the MTU. | |
1208 | * Otherwise, we need to reserve fragment header and | |
1209 | * fragment alignment (= 8-15 octects, in total). | |
1210 | * | |
1211 | * Note that we may need to "move" the data from the tail of | |
1212 | * of the buffer to the new fragment when we split | |
1213 | * the message. | |
1214 | * | |
1215 | * FIXME: It may be fragmented into multiple chunks | |
1216 | * at once if non-fragmentable extension headers | |
1217 | * are too large. | |
1218 | * --yoshfuji | |
1219 | */ | |
1220 | ||
1221 | inet->cork.length += length; | |
1222 | if (((length > mtu) && (sk->sk_protocol == IPPROTO_UDP)) && | |
1223 | (rt->u.dst.dev->features & NETIF_F_UFO)) { | |
1224 | ||
1225 | err = ip6_ufo_append_data(sk, getfrag, from, length, hh_len, | |
1226 | fragheaderlen, transhdrlen, mtu, | |
1227 | flags); | |
1228 | if (err) | |
1229 | goto error; | |
1230 | return 0; | |
1231 | } | |
1232 | ||
1233 | if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) | |
1234 | goto alloc_new_skb; | |
1235 | ||
1236 | while (length > 0) { | |
1237 | /* Check if the remaining data fits into current packet. */ | |
1238 | copy = (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len; | |
1239 | if (copy < length) | |
1240 | copy = maxfraglen - skb->len; | |
1241 | ||
1242 | if (copy <= 0) { | |
1243 | char *data; | |
1244 | unsigned int datalen; | |
1245 | unsigned int fraglen; | |
1246 | unsigned int fraggap; | |
1247 | unsigned int alloclen; | |
1248 | struct sk_buff *skb_prev; | |
1249 | alloc_new_skb: | |
1250 | skb_prev = skb; | |
1251 | ||
1252 | /* There's no room in the current skb */ | |
1253 | if (skb_prev) | |
1254 | fraggap = skb_prev->len - maxfraglen; | |
1255 | else | |
1256 | fraggap = 0; | |
1257 | ||
1258 | /* | |
1259 | * If remaining data exceeds the mtu, | |
1260 | * we know we need more fragment(s). | |
1261 | */ | |
1262 | datalen = length + fraggap; | |
1263 | if (datalen > (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen) | |
1264 | datalen = maxfraglen - fragheaderlen; | |
1265 | ||
1266 | fraglen = datalen + fragheaderlen; | |
1267 | if ((flags & MSG_MORE) && | |
1268 | !(rt->u.dst.dev->features&NETIF_F_SG)) | |
1269 | alloclen = mtu; | |
1270 | else | |
1271 | alloclen = datalen + fragheaderlen; | |
1272 | ||
1273 | /* | |
1274 | * The last fragment gets additional space at tail. | |
1275 | * Note: we overallocate on fragments with MSG_MODE | |
1276 | * because we have no idea if we're the last one. | |
1277 | */ | |
1278 | if (datalen == length + fraggap) | |
1279 | alloclen += rt->u.dst.trailer_len; | |
1280 | ||
1281 | /* | |
1282 | * We just reserve space for fragment header. | |
1283 | * Note: this may be overallocation if the message | |
1284 | * (without MSG_MORE) fits into the MTU. | |
1285 | */ | |
1286 | alloclen += sizeof(struct frag_hdr); | |
1287 | ||
1288 | if (transhdrlen) { | |
1289 | skb = sock_alloc_send_skb(sk, | |
1290 | alloclen + hh_len, | |
1291 | (flags & MSG_DONTWAIT), &err); | |
1292 | } else { | |
1293 | skb = NULL; | |
1294 | if (atomic_read(&sk->sk_wmem_alloc) <= | |
1295 | 2 * sk->sk_sndbuf) | |
1296 | skb = sock_wmalloc(sk, | |
1297 | alloclen + hh_len, 1, | |
1298 | sk->sk_allocation); | |
1299 | if (unlikely(skb == NULL)) | |
1300 | err = -ENOBUFS; | |
1301 | } | |
1302 | if (skb == NULL) | |
1303 | goto error; | |
1304 | /* | |
1305 | * Fill in the control structures | |
1306 | */ | |
1307 | skb->ip_summed = csummode; | |
1308 | skb->csum = 0; | |
1309 | /* reserve for fragmentation */ | |
1310 | skb_reserve(skb, hh_len+sizeof(struct frag_hdr)); | |
1311 | ||
1312 | /* | |
1313 | * Find where to start putting bytes | |
1314 | */ | |
1315 | data = skb_put(skb, fraglen); | |
1316 | skb_set_network_header(skb, exthdrlen); | |
1317 | data += fragheaderlen; | |
1318 | skb->transport_header = (skb->network_header + | |
1319 | fragheaderlen); | |
1320 | if (fraggap) { | |
1321 | skb->csum = skb_copy_and_csum_bits( | |
1322 | skb_prev, maxfraglen, | |
1323 | data + transhdrlen, fraggap, 0); | |
1324 | skb_prev->csum = csum_sub(skb_prev->csum, | |
1325 | skb->csum); | |
1326 | data += fraggap; | |
1327 | pskb_trim_unique(skb_prev, maxfraglen); | |
1328 | } | |
1329 | copy = datalen - transhdrlen - fraggap; | |
1330 | if (copy < 0) { | |
1331 | err = -EINVAL; | |
1332 | kfree_skb(skb); | |
1333 | goto error; | |
1334 | } else if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) { | |
1335 | err = -EFAULT; | |
1336 | kfree_skb(skb); | |
1337 | goto error; | |
1338 | } | |
1339 | ||
1340 | offset += copy; | |
1341 | length -= datalen - fraggap; | |
1342 | transhdrlen = 0; | |
1343 | exthdrlen = 0; | |
1344 | csummode = CHECKSUM_NONE; | |
1345 | ||
1346 | /* | |
1347 | * Put the packet on the pending queue | |
1348 | */ | |
1349 | __skb_queue_tail(&sk->sk_write_queue, skb); | |
1350 | continue; | |
1351 | } | |
1352 | ||
1353 | if (copy > length) | |
1354 | copy = length; | |
1355 | ||
1356 | if (!(rt->u.dst.dev->features&NETIF_F_SG)) { | |
1357 | unsigned int off; | |
1358 | ||
1359 | off = skb->len; | |
1360 | if (getfrag(from, skb_put(skb, copy), | |
1361 | offset, copy, off, skb) < 0) { | |
1362 | __skb_trim(skb, off); | |
1363 | err = -EFAULT; | |
1364 | goto error; | |
1365 | } | |
1366 | } else { | |
1367 | int i = skb_shinfo(skb)->nr_frags; | |
1368 | skb_frag_t *frag = &skb_shinfo(skb)->frags[i-1]; | |
1369 | struct page *page = sk->sk_sndmsg_page; | |
1370 | int off = sk->sk_sndmsg_off; | |
1371 | unsigned int left; | |
1372 | ||
1373 | if (page && (left = PAGE_SIZE - off) > 0) { | |
1374 | if (copy >= left) | |
1375 | copy = left; | |
1376 | if (page != frag->page) { | |
1377 | if (i == MAX_SKB_FRAGS) { | |
1378 | err = -EMSGSIZE; | |
1379 | goto error; | |
1380 | } | |
1381 | get_page(page); | |
1382 | skb_fill_page_desc(skb, i, page, sk->sk_sndmsg_off, 0); | |
1383 | frag = &skb_shinfo(skb)->frags[i]; | |
1384 | } | |
1385 | } else if(i < MAX_SKB_FRAGS) { | |
1386 | if (copy > PAGE_SIZE) | |
1387 | copy = PAGE_SIZE; | |
1388 | page = alloc_pages(sk->sk_allocation, 0); | |
1389 | if (page == NULL) { | |
1390 | err = -ENOMEM; | |
1391 | goto error; | |
1392 | } | |
1393 | sk->sk_sndmsg_page = page; | |
1394 | sk->sk_sndmsg_off = 0; | |
1395 | ||
1396 | skb_fill_page_desc(skb, i, page, 0, 0); | |
1397 | frag = &skb_shinfo(skb)->frags[i]; | |
1398 | } else { | |
1399 | err = -EMSGSIZE; | |
1400 | goto error; | |
1401 | } | |
1402 | if (getfrag(from, page_address(frag->page)+frag->page_offset+frag->size, offset, copy, skb->len, skb) < 0) { | |
1403 | err = -EFAULT; | |
1404 | goto error; | |
1405 | } | |
1406 | sk->sk_sndmsg_off += copy; | |
1407 | frag->size += copy; | |
1408 | skb->len += copy; | |
1409 | skb->data_len += copy; | |
1410 | skb->truesize += copy; | |
1411 | atomic_add(copy, &sk->sk_wmem_alloc); | |
1412 | } | |
1413 | offset += copy; | |
1414 | length -= copy; | |
1415 | } | |
1416 | return 0; | |
1417 | error: | |
1418 | inet->cork.length -= length; | |
1419 | IP6_INC_STATS(sock_net(sk), rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS); | |
1420 | return err; | |
1421 | } | |
1422 | ||
1423 | static void ip6_cork_release(struct inet_sock *inet, struct ipv6_pinfo *np) | |
1424 | { | |
1425 | if (np->cork.opt) { | |
1426 | kfree(np->cork.opt->dst0opt); | |
1427 | kfree(np->cork.opt->dst1opt); | |
1428 | kfree(np->cork.opt->hopopt); | |
1429 | kfree(np->cork.opt->srcrt); | |
1430 | kfree(np->cork.opt); | |
1431 | np->cork.opt = NULL; | |
1432 | } | |
1433 | ||
1434 | if (inet->cork.dst) { | |
1435 | dst_release(inet->cork.dst); | |
1436 | inet->cork.dst = NULL; | |
1437 | inet->cork.flags &= ~IPCORK_ALLFRAG; | |
1438 | } | |
1439 | memset(&inet->cork.fl, 0, sizeof(inet->cork.fl)); | |
1440 | } | |
1441 | ||
1442 | int ip6_push_pending_frames(struct sock *sk) | |
1443 | { | |
1444 | struct sk_buff *skb, *tmp_skb; | |
1445 | struct sk_buff **tail_skb; | |
1446 | struct in6_addr final_dst_buf, *final_dst = &final_dst_buf; | |
1447 | struct inet_sock *inet = inet_sk(sk); | |
1448 | struct ipv6_pinfo *np = inet6_sk(sk); | |
1449 | struct net *net = sock_net(sk); | |
1450 | struct ipv6hdr *hdr; | |
1451 | struct ipv6_txoptions *opt = np->cork.opt; | |
1452 | struct rt6_info *rt = (struct rt6_info *)inet->cork.dst; | |
1453 | struct flowi *fl = &inet->cork.fl; | |
1454 | unsigned char proto = fl->proto; | |
1455 | int err = 0; | |
1456 | ||
1457 | if ((skb = __skb_dequeue(&sk->sk_write_queue)) == NULL) | |
1458 | goto out; | |
1459 | tail_skb = &(skb_shinfo(skb)->frag_list); | |
1460 | ||
1461 | /* move skb->data to ip header from ext header */ | |
1462 | if (skb->data < skb_network_header(skb)) | |
1463 | __skb_pull(skb, skb_network_offset(skb)); | |
1464 | while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) { | |
1465 | __skb_pull(tmp_skb, skb_network_header_len(skb)); | |
1466 | *tail_skb = tmp_skb; | |
1467 | tail_skb = &(tmp_skb->next); | |
1468 | skb->len += tmp_skb->len; | |
1469 | skb->data_len += tmp_skb->len; | |
1470 | skb->truesize += tmp_skb->truesize; | |
1471 | tmp_skb->destructor = NULL; | |
1472 | tmp_skb->sk = NULL; | |
1473 | } | |
1474 | ||
1475 | /* Allow local fragmentation. */ | |
1476 | if (np->pmtudisc < IPV6_PMTUDISC_DO) | |
1477 | skb->local_df = 1; | |
1478 | ||
1479 | ipv6_addr_copy(final_dst, &fl->fl6_dst); | |
1480 | __skb_pull(skb, skb_network_header_len(skb)); | |
1481 | if (opt && opt->opt_flen) | |
1482 | ipv6_push_frag_opts(skb, opt, &proto); | |
1483 | if (opt && opt->opt_nflen) | |
1484 | ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst); | |
1485 | ||
1486 | skb_push(skb, sizeof(struct ipv6hdr)); | |
1487 | skb_reset_network_header(skb); | |
1488 | hdr = ipv6_hdr(skb); | |
1489 | ||
1490 | *(__be32*)hdr = fl->fl6_flowlabel | | |
1491 | htonl(0x60000000 | ((int)np->cork.tclass << 20)); | |
1492 | ||
1493 | hdr->hop_limit = np->cork.hop_limit; | |
1494 | hdr->nexthdr = proto; | |
1495 | ipv6_addr_copy(&hdr->saddr, &fl->fl6_src); | |
1496 | ipv6_addr_copy(&hdr->daddr, final_dst); | |
1497 | ||
1498 | skb->priority = sk->sk_priority; | |
1499 | skb->mark = sk->sk_mark; | |
1500 | ||
1501 | skb_dst_set(skb, dst_clone(&rt->u.dst)); | |
1502 | IP6_UPD_PO_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUT, skb->len); | |
1503 | if (proto == IPPROTO_ICMPV6) { | |
1504 | struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); | |
1505 | ||
1506 | ICMP6MSGOUT_INC_STATS_BH(net, idev, icmp6_hdr(skb)->icmp6_type); | |
1507 | ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTMSGS); | |
1508 | } | |
1509 | ||
1510 | err = ip6_local_out(skb); | |
1511 | if (err) { | |
1512 | if (err > 0) | |
1513 | err = net_xmit_errno(err); | |
1514 | if (err) | |
1515 | goto error; | |
1516 | } | |
1517 | ||
1518 | out: | |
1519 | ip6_cork_release(inet, np); | |
1520 | return err; | |
1521 | error: | |
1522 | IP6_INC_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS); | |
1523 | goto out; | |
1524 | } | |
1525 | ||
1526 | void ip6_flush_pending_frames(struct sock *sk) | |
1527 | { | |
1528 | struct sk_buff *skb; | |
1529 | ||
1530 | while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) { | |
1531 | if (skb_dst(skb)) | |
1532 | IP6_INC_STATS(sock_net(sk), ip6_dst_idev(skb_dst(skb)), | |
1533 | IPSTATS_MIB_OUTDISCARDS); | |
1534 | kfree_skb(skb); | |
1535 | } | |
1536 | ||
1537 | ip6_cork_release(inet_sk(sk), inet6_sk(sk)); | |
1538 | } |