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[XFRM]: Fix wildcard as tunnel source
[hh.org.git] / net / ipv6 / ip6_output.c
blobc14ea1ecf37927ef149d4fcb76d7fe20967d9c3f
1 /*
2 * IPv6 output functions
3 * Linux INET6 implementation
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 *
8 * $Id: ip6_output.c,v 1.34 2002/02/01 22:01:04 davem Exp $
9 *
10 * Based on linux/net/ipv4/ip_output.c
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; either version
15 * 2 of the License, or (at your option) any later version.
16 *
17 * Changes:
18 * A.N.Kuznetsov : airthmetics in fragmentation.
19 * extension headers are implemented.
20 * route changes now work.
21 * ip6_forward does not confuse sniffers.
22 * etc.
23 *
24 * H. von Brand : Added missing #include <linux/string.h>
25 * Imran Patel : frag id should be in NBO
26 * Kazunori MIYAZAWA @USAGI
27 * : add ip6_append_data and related functions
28 * for datagram xmit
29 */
30
31 #include <linux/errno.h>
32 #include <linux/types.h>
33 #include <linux/string.h>
34 #include <linux/socket.h>
35 #include <linux/net.h>
36 #include <linux/netdevice.h>
37 #include <linux/if_arp.h>
38 #include <linux/in6.h>
39 #include <linux/tcp.h>
40 #include <linux/route.h>
41 #include <linux/module.h>
42
43 #include <linux/netfilter.h>
44 #include <linux/netfilter_ipv6.h>
45
46 #include <net/sock.h>
47 #include <net/snmp.h>
48
49 #include <net/ipv6.h>
50 #include <net/ndisc.h>
51 #include <net/protocol.h>
52 #include <net/ip6_route.h>
53 #include <net/addrconf.h>
54 #include <net/rawv6.h>
55 #include <net/icmp.h>
56 #include <net/xfrm.h>
57 #include <net/checksum.h>
58
59 static int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *));
60
61 static __inline__ void ipv6_select_ident(struct sk_buff *skb, struct frag_hdr *fhdr)
62 {
63 static u32 ipv6_fragmentation_id = 1;
64 static DEFINE_SPINLOCK(ip6_id_lock);
65
66 spin_lock_bh(&ip6_id_lock);
67 fhdr->identification = htonl(ipv6_fragmentation_id);
68 if (++ipv6_fragmentation_id == 0)
69 ipv6_fragmentation_id = 1;
70 spin_unlock_bh(&ip6_id_lock);
71 }
72
73 static inline int ip6_output_finish(struct sk_buff *skb)
74 {
75
76 struct dst_entry *dst = skb->dst;
77 struct hh_cache *hh = dst->hh;
78
79 if (hh) {
80 int hh_alen;
81
82 read_lock_bh(&hh->hh_lock);
83 hh_alen = HH_DATA_ALIGN(hh->hh_len);
84 memcpy(skb->data - hh_alen, hh->hh_data, hh_alen);
85 read_unlock_bh(&hh->hh_lock);
86 skb_push(skb, hh->hh_len);
87 return hh->hh_output(skb);
88 } else if (dst->neighbour)
89 return dst->neighbour->output(skb);
90
91 IP6_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES);
92 kfree_skb(skb);
93 return -EINVAL;
94
95 }
96
97 /* dev_loopback_xmit for use with netfilter. */
98 static int ip6_dev_loopback_xmit(struct sk_buff *newskb)
99 {
100 newskb->mac.raw = newskb->data;
101 __skb_pull(newskb, newskb->nh.raw - newskb->data);
102 newskb->pkt_type = PACKET_LOOPBACK;
103 newskb->ip_summed = CHECKSUM_UNNECESSARY;
104 BUG_TRAP(newskb->dst);
105
106 netif_rx(newskb);
107 return 0;
108 }
109
110
111 static int ip6_output2(struct sk_buff *skb)
112 {
113 struct dst_entry *dst = skb->dst;
114 struct net_device *dev = dst->dev;
115
116 skb->protocol = htons(ETH_P_IPV6);
117 skb->dev = dev;
118
119 if (ipv6_addr_is_multicast(&skb->nh.ipv6h->daddr)) {
120 struct ipv6_pinfo* np = skb->sk ? inet6_sk(skb->sk) : NULL;
121
122 if (!(dev->flags & IFF_LOOPBACK) && (!np || np->mc_loop) &&
123 ipv6_chk_mcast_addr(dev, &skb->nh.ipv6h->daddr,
124 &skb->nh.ipv6h->saddr)) {
125 struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC);
126
127 /* Do not check for IFF_ALLMULTI; multicast routing
128 is not supported in any case.
129 */
130 if (newskb)
131 NF_HOOK(PF_INET6, NF_IP6_POST_ROUTING, newskb, NULL,
132 newskb->dev,
133 ip6_dev_loopback_xmit);
134
135 if (skb->nh.ipv6h->hop_limit == 0) {
136 IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
137 kfree_skb(skb);
138 return 0;
139 }
140 }
141
142 IP6_INC_STATS(IPSTATS_MIB_OUTMCASTPKTS);
143 }
144
145 return NF_HOOK(PF_INET6, NF_IP6_POST_ROUTING, skb,NULL, skb->dev,ip6_output_finish);
146 }
147
148 int ip6_output(struct sk_buff *skb)
149 {
150 if ((skb->len > dst_mtu(skb->dst) && !skb_is_gso(skb)) ||
151 dst_allfrag(skb->dst))
152 return ip6_fragment(skb, ip6_output2);
153 else
154 return ip6_output2(skb);
155 }
156
157 /*
158 * xmit an sk_buff (used by TCP)
159 */
160
161 int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl,
162 struct ipv6_txoptions *opt, int ipfragok)
163 {
164 struct ipv6_pinfo *np = inet6_sk(sk);
165 struct in6_addr *first_hop = &fl->fl6_dst;
166 struct dst_entry *dst = skb->dst;
167 struct ipv6hdr *hdr;
168 u8 proto = fl->proto;
169 int seg_len = skb->len;
170 int hlimit, tclass;
171 u32 mtu;
172
173 if (opt) {
174 int head_room;
175
176 /* First: exthdrs may take lots of space (~8K for now)
177 MAX_HEADER is not enough.
178 */
179 head_room = opt->opt_nflen + opt->opt_flen;
180 seg_len += head_room;
181 head_room += sizeof(struct ipv6hdr) + LL_RESERVED_SPACE(dst->dev);
182
183 if (skb_headroom(skb) < head_room) {
184 struct sk_buff *skb2 = skb_realloc_headroom(skb, head_room);
185 kfree_skb(skb);
186 skb = skb2;
187 if (skb == NULL) {
188 IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
189 return -ENOBUFS;
190 }
191 if (sk)
192 skb_set_owner_w(skb, sk);
193 }
194 if (opt->opt_flen)
195 ipv6_push_frag_opts(skb, opt, &proto);
196 if (opt->opt_nflen)
197 ipv6_push_nfrag_opts(skb, opt, &proto, &first_hop);
198 }
199
200 hdr = skb->nh.ipv6h = (struct ipv6hdr*)skb_push(skb, sizeof(struct ipv6hdr));
201
202 /*
203 * Fill in the IPv6 header
204 */
205
206 hlimit = -1;
207 if (np)
208 hlimit = np->hop_limit;
209 if (hlimit < 0)
210 hlimit = dst_metric(dst, RTAX_HOPLIMIT);
211 if (hlimit < 0)
212 hlimit = ipv6_get_hoplimit(dst->dev);
213
214 tclass = -1;
215 if (np)
216 tclass = np->tclass;
217 if (tclass < 0)
218 tclass = 0;
219
220 *(u32 *)hdr = htonl(0x60000000 | (tclass << 20)) | fl->fl6_flowlabel;
221
222 hdr->payload_len = htons(seg_len);
223 hdr->nexthdr = proto;
224 hdr->hop_limit = hlimit;
225
226 ipv6_addr_copy(&hdr->saddr, &fl->fl6_src);
227 ipv6_addr_copy(&hdr->daddr, first_hop);
228
229 skb->priority = sk->sk_priority;
230
231 mtu = dst_mtu(dst);
232 if ((skb->len <= mtu) || ipfragok || skb_is_gso(skb)) {
233 IP6_INC_STATS(IPSTATS_MIB_OUTREQUESTS);
234 return NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, dst->dev,
235 dst_output);
236 }
237
238 if (net_ratelimit())
239 printk(KERN_DEBUG "IPv6: sending pkt_too_big to self\n");
240 skb->dev = dst->dev;
241 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, skb->dev);
242 IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
243 kfree_skb(skb);
244 return -EMSGSIZE;
245 }
246
247 /*
248 * To avoid extra problems ND packets are send through this
249 * routine. It's code duplication but I really want to avoid
250 * extra checks since ipv6_build_header is used by TCP (which
251 * is for us performance critical)
252 */
253
254 int ip6_nd_hdr(struct sock *sk, struct sk_buff *skb, struct net_device *dev,
255 struct in6_addr *saddr, struct in6_addr *daddr,
256 int proto, int len)
257 {
258 struct ipv6_pinfo *np = inet6_sk(sk);
259 struct ipv6hdr *hdr;
260 int totlen;
261
262 skb->protocol = htons(ETH_P_IPV6);
263 skb->dev = dev;
264
265 totlen = len + sizeof(struct ipv6hdr);
266
267 hdr = (struct ipv6hdr *) skb_put(skb, sizeof(struct ipv6hdr));
268 skb->nh.ipv6h = hdr;
269
270 *(u32*)hdr = htonl(0x60000000);
271
272 hdr->payload_len = htons(len);
273 hdr->nexthdr = proto;
274 hdr->hop_limit = np->hop_limit;
275
276 ipv6_addr_copy(&hdr->saddr, saddr);
277 ipv6_addr_copy(&hdr->daddr, daddr);
278
279 return 0;
280 }
281
282 static int ip6_call_ra_chain(struct sk_buff *skb, int sel)
283 {
284 struct ip6_ra_chain *ra;
285 struct sock *last = NULL;
286
287 read_lock(&ip6_ra_lock);
288 for (ra = ip6_ra_chain; ra; ra = ra->next) {
289 struct sock *sk = ra->sk;
290 if (sk && ra->sel == sel &&
291 (!sk->sk_bound_dev_if ||
292 sk->sk_bound_dev_if == skb->dev->ifindex)) {
293 if (last) {
294 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
295 if (skb2)
296 rawv6_rcv(last, skb2);
297 }
298 last = sk;
299 }
300 }
301
302 if (last) {
303 rawv6_rcv(last, skb);
304 read_unlock(&ip6_ra_lock);
305 return 1;
306 }
307 read_unlock(&ip6_ra_lock);
308 return 0;
309 }
310
311 static inline int ip6_forward_finish(struct sk_buff *skb)
312 {
313 return dst_output(skb);
314 }
315
316 int ip6_forward(struct sk_buff *skb)
317 {
318 struct dst_entry *dst = skb->dst;
319 struct ipv6hdr *hdr = skb->nh.ipv6h;
320 struct inet6_skb_parm *opt = IP6CB(skb);
321
322 if (ipv6_devconf.forwarding == 0)
323 goto error;
324
325 if (!xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) {
326 IP6_INC_STATS(IPSTATS_MIB_INDISCARDS);
327 goto drop;
328 }
329
330 skb->ip_summed = CHECKSUM_NONE;
331
332 /*
333 * We DO NOT make any processing on
334 * RA packets, pushing them to user level AS IS
335 * without ane WARRANTY that application will be able
336 * to interpret them. The reason is that we
337 * cannot make anything clever here.
338 *
339 * We are not end-node, so that if packet contains
340 * AH/ESP, we cannot make anything.
341 * Defragmentation also would be mistake, RA packets
342 * cannot be fragmented, because there is no warranty
343 * that different fragments will go along one path. --ANK
344 */
345 if (opt->ra) {
346 u8 *ptr = skb->nh.raw + opt->ra;
347 if (ip6_call_ra_chain(skb, (ptr[2]<<8) + ptr[3]))
348 return 0;
349 }
350
351 /*
352 * check and decrement ttl
353 */
354 if (hdr->hop_limit <= 1) {
355 /* Force OUTPUT device used as source address */
356 skb->dev = dst->dev;
357 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
358 0, skb->dev);
359 IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
360
361 kfree_skb(skb);
362 return -ETIMEDOUT;
363 }
364
365 if (!xfrm6_route_forward(skb)) {
366 IP6_INC_STATS(IPSTATS_MIB_INDISCARDS);
367 goto drop;
368 }
369 dst = skb->dst;
370
371 /* IPv6 specs say nothing about it, but it is clear that we cannot
372 send redirects to source routed frames.
373 */
374 if (skb->dev == dst->dev && dst->neighbour && opt->srcrt == 0) {
375 struct in6_addr *target = NULL;
376 struct rt6_info *rt;
377 struct neighbour *n = dst->neighbour;
378
379 /*
380 * incoming and outgoing devices are the same
381 * send a redirect.
382 */
383
384 rt = (struct rt6_info *) dst;
385 if ((rt->rt6i_flags & RTF_GATEWAY))
386 target = (struct in6_addr*)&n->primary_key;
387 else
388 target = &hdr->daddr;
389
390 /* Limit redirects both by destination (here)
391 and by source (inside ndisc_send_redirect)
392 */
393 if (xrlim_allow(dst, 1*HZ))
394 ndisc_send_redirect(skb, n, target);
395 } else if (ipv6_addr_type(&hdr->saddr)&(IPV6_ADDR_MULTICAST|IPV6_ADDR_LOOPBACK
396 |IPV6_ADDR_LINKLOCAL)) {
397 /* This check is security critical. */
398 goto error;
399 }
400
401 if (skb->len > dst_mtu(dst)) {
402 /* Again, force OUTPUT device used as source address */
403 skb->dev = dst->dev;
404 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, dst_mtu(dst), skb->dev);
405 IP6_INC_STATS_BH(IPSTATS_MIB_INTOOBIGERRORS);
406 IP6_INC_STATS_BH(IPSTATS_MIB_FRAGFAILS);
407 kfree_skb(skb);
408 return -EMSGSIZE;
409 }
410
411 if (skb_cow(skb, dst->dev->hard_header_len)) {
412 IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
413 goto drop;
414 }
415
416 hdr = skb->nh.ipv6h;
417
418 /* Mangling hops number delayed to point after skb COW */
419
420 hdr->hop_limit--;
421
422 IP6_INC_STATS_BH(IPSTATS_MIB_OUTFORWDATAGRAMS);
423 return NF_HOOK(PF_INET6,NF_IP6_FORWARD, skb, skb->dev, dst->dev, ip6_forward_finish);
424
425 error:
426 IP6_INC_STATS_BH(IPSTATS_MIB_INADDRERRORS);
427 drop:
428 kfree_skb(skb);
429 return -EINVAL;
430 }
431
432 static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from)
433 {
434 to->pkt_type = from->pkt_type;
435 to->priority = from->priority;
436 to->protocol = from->protocol;
437 dst_release(to->dst);
438 to->dst = dst_clone(from->dst);
439 to->dev = from->dev;
440
441 #ifdef CONFIG_NET_SCHED
442 to->tc_index = from->tc_index;
443 #endif
444 #ifdef CONFIG_NETFILTER
445 to->nfmark = from->nfmark;
446 /* Connection association is same as pre-frag packet */
447 nf_conntrack_put(to->nfct);
448 to->nfct = from->nfct;
449 nf_conntrack_get(to->nfct);
450 to->nfctinfo = from->nfctinfo;
451 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
452 nf_conntrack_put_reasm(to->nfct_reasm);
453 to->nfct_reasm = from->nfct_reasm;
454 nf_conntrack_get_reasm(to->nfct_reasm);
455 #endif
456 #ifdef CONFIG_BRIDGE_NETFILTER
457 nf_bridge_put(to->nf_bridge);
458 to->nf_bridge = from->nf_bridge;
459 nf_bridge_get(to->nf_bridge);
460 #endif
461 #endif
462 skb_copy_secmark(to, from);
463 }
464
465 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr)
466 {
467 u16 offset = sizeof(struct ipv6hdr);
468 struct ipv6_opt_hdr *exthdr = (struct ipv6_opt_hdr*)(skb->nh.ipv6h + 1);
469 unsigned int packet_len = skb->tail - skb->nh.raw;
470 int found_rhdr = 0;
471 *nexthdr = &skb->nh.ipv6h->nexthdr;
472
473 while (offset + 1 <= packet_len) {
474
475 switch (**nexthdr) {
476
477 case NEXTHDR_HOP:
478 break;
479 case NEXTHDR_ROUTING:
480 found_rhdr = 1;
481 break;
482 case NEXTHDR_DEST:
483 #ifdef CONFIG_IPV6_MIP6
484 if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
485 break;
486 #endif
487 if (found_rhdr)
488 return offset;
489 break;
490 default :
491 return offset;
492 }
493
494 offset += ipv6_optlen(exthdr);
495 *nexthdr = &exthdr->nexthdr;
496 exthdr = (struct ipv6_opt_hdr*)(skb->nh.raw + offset);
497 }
498
499 return offset;
500 }
501 EXPORT_SYMBOL_GPL(ip6_find_1stfragopt);
502
503 static int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *))
504 {
505 struct net_device *dev;
506 struct sk_buff *frag;
507 struct rt6_info *rt = (struct rt6_info*)skb->dst;
508 struct ipv6_pinfo *np = skb->sk ? inet6_sk(skb->sk) : NULL;
509 struct ipv6hdr *tmp_hdr;
510 struct frag_hdr *fh;
511 unsigned int mtu, hlen, left, len;
512 u32 frag_id = 0;
513 int ptr, offset = 0, err=0;
514 u8 *prevhdr, nexthdr = 0;
515
516 dev = rt->u.dst.dev;
517 hlen = ip6_find_1stfragopt(skb, &prevhdr);
518 nexthdr = *prevhdr;
519
520 mtu = dst_mtu(&rt->u.dst);
521 if (np && np->frag_size < mtu) {
522 if (np->frag_size)
523 mtu = np->frag_size;
524 }
525 mtu -= hlen + sizeof(struct frag_hdr);
526
527 if (skb_shinfo(skb)->frag_list) {
528 int first_len = skb_pagelen(skb);
529
530 if (first_len - hlen > mtu ||
531 ((first_len - hlen) & 7) ||
532 skb_cloned(skb))
533 goto slow_path;
534
535 for (frag = skb_shinfo(skb)->frag_list; frag; frag = frag->next) {
536 /* Correct geometry. */
537 if (frag->len > mtu ||
538 ((frag->len & 7) && frag->next) ||
539 skb_headroom(frag) < hlen)
540 goto slow_path;
541
542 /* Partially cloned skb? */
543 if (skb_shared(frag))
544 goto slow_path;
545
546 BUG_ON(frag->sk);
547 if (skb->sk) {
548 sock_hold(skb->sk);
549 frag->sk = skb->sk;
550 frag->destructor = sock_wfree;
551 skb->truesize -= frag->truesize;
552 }
553 }
554
555 err = 0;
556 offset = 0;
557 frag = skb_shinfo(skb)->frag_list;
558 skb_shinfo(skb)->frag_list = NULL;
559 /* BUILD HEADER */
560
561 tmp_hdr = kmalloc(hlen, GFP_ATOMIC);
562 if (!tmp_hdr) {
563 IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
564 return -ENOMEM;
565 }
566
567 *prevhdr = NEXTHDR_FRAGMENT;
568 memcpy(tmp_hdr, skb->nh.raw, hlen);
569 __skb_pull(skb, hlen);
570 fh = (struct frag_hdr*)__skb_push(skb, sizeof(struct frag_hdr));
571 skb->nh.raw = __skb_push(skb, hlen);
572 memcpy(skb->nh.raw, tmp_hdr, hlen);
573
574 ipv6_select_ident(skb, fh);
575 fh->nexthdr = nexthdr;
576 fh->reserved = 0;
577 fh->frag_off = htons(IP6_MF);
578 frag_id = fh->identification;
579
580 first_len = skb_pagelen(skb);
581 skb->data_len = first_len - skb_headlen(skb);
582 skb->len = first_len;
583 skb->nh.ipv6h->payload_len = htons(first_len - sizeof(struct ipv6hdr));
584
585
586 for (;;) {
587 /* Prepare header of the next frame,
588 * before previous one went down. */
589 if (frag) {
590 frag->ip_summed = CHECKSUM_NONE;
591 frag->h.raw = frag->data;
592 fh = (struct frag_hdr*)__skb_push(frag, sizeof(struct frag_hdr));
593 frag->nh.raw = __skb_push(frag, hlen);
594 memcpy(frag->nh.raw, tmp_hdr, hlen);
595 offset += skb->len - hlen - sizeof(struct frag_hdr);
596 fh->nexthdr = nexthdr;
597 fh->reserved = 0;
598 fh->frag_off = htons(offset);
599 if (frag->next != NULL)
600 fh->frag_off |= htons(IP6_MF);
601 fh->identification = frag_id;
602 frag->nh.ipv6h->payload_len = htons(frag->len - sizeof(struct ipv6hdr));
603 ip6_copy_metadata(frag, skb);
604 }
605
606 err = output(skb);
607 if(!err)
608 IP6_INC_STATS(IPSTATS_MIB_FRAGCREATES);
609
610 if (err || !frag)
611 break;
612
613 skb = frag;
614 frag = skb->next;
615 skb->next = NULL;
616 }
617
618 kfree(tmp_hdr);
619
620 if (err == 0) {
621 IP6_INC_STATS(IPSTATS_MIB_FRAGOKS);
622 return 0;
623 }
624
625 while (frag) {
626 skb = frag->next;
627 kfree_skb(frag);
628 frag = skb;
629 }
630
631 IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
632 return err;
633 }
634
635 slow_path:
636 left = skb->len - hlen; /* Space per frame */
637 ptr = hlen; /* Where to start from */
638
639 /*
640 * Fragment the datagram.
641 */
642
643 *prevhdr = NEXTHDR_FRAGMENT;
644
645 /*
646 * Keep copying data until we run out.
647 */
648 while(left > 0) {
649 len = left;
650 /* IF: it doesn't fit, use 'mtu' - the data space left */
651 if (len > mtu)
652 len = mtu;
653 /* IF: we are not sending upto and including the packet end
654 then align the next start on an eight byte boundary */
655 if (len < left) {
656 len &= ~7;
657 }
658 /*
659 * Allocate buffer.
660 */
661
662 if ((frag = alloc_skb(len+hlen+sizeof(struct frag_hdr)+LL_RESERVED_SPACE(rt->u.dst.dev), GFP_ATOMIC)) == NULL) {
663 NETDEBUG(KERN_INFO "IPv6: frag: no memory for new fragment!\n");
664 IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
665 err = -ENOMEM;
666 goto fail;
667 }
668
669 /*
670 * Set up data on packet
671 */
672
673 ip6_copy_metadata(frag, skb);
674 skb_reserve(frag, LL_RESERVED_SPACE(rt->u.dst.dev));
675 skb_put(frag, len + hlen + sizeof(struct frag_hdr));
676 frag->nh.raw = frag->data;
677 fh = (struct frag_hdr*)(frag->data + hlen);
678 frag->h.raw = frag->data + hlen + sizeof(struct frag_hdr);
679
680 /*
681 * Charge the memory for the fragment to any owner
682 * it might possess
683 */
684 if (skb->sk)
685 skb_set_owner_w(frag, skb->sk);
686
687 /*
688 * Copy the packet header into the new buffer.
689 */
690 memcpy(frag->nh.raw, skb->data, hlen);
691
692 /*
693 * Build fragment header.
694 */
695 fh->nexthdr = nexthdr;
696 fh->reserved = 0;
697 if (!frag_id) {
698 ipv6_select_ident(skb, fh);
699 frag_id = fh->identification;
700 } else
701 fh->identification = frag_id;
702
703 /*
704 * Copy a block of the IP datagram.
705 */
706 if (skb_copy_bits(skb, ptr, frag->h.raw, len))
707 BUG();
708 left -= len;
709
710 fh->frag_off = htons(offset);
711 if (left > 0)
712 fh->frag_off |= htons(IP6_MF);
713 frag->nh.ipv6h->payload_len = htons(frag->len - sizeof(struct ipv6hdr));
714
715 ptr += len;
716 offset += len;
717
718 /*
719 * Put this fragment into the sending queue.
720 */
721 err = output(frag);
722 if (err)
723 goto fail;
724
725 IP6_INC_STATS(IPSTATS_MIB_FRAGCREATES);
726 }
727 kfree_skb(skb);
728 IP6_INC_STATS(IPSTATS_MIB_FRAGOKS);
729 return err;
730
731 fail:
732 kfree_skb(skb);
733 IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
734 return err;
735 }
736
737 static inline int ip6_rt_check(struct rt6key *rt_key,
738 struct in6_addr *fl_addr,
739 struct in6_addr *addr_cache)
740 {
741 return ((rt_key->plen != 128 || !ipv6_addr_equal(fl_addr, &rt_key->addr)) &&
742 (addr_cache == NULL || !ipv6_addr_equal(fl_addr, addr_cache)));
743 }
744
745 static struct dst_entry *ip6_sk_dst_check(struct sock *sk,
746 struct dst_entry *dst,
747 struct flowi *fl)
748 {
749 struct ipv6_pinfo *np = inet6_sk(sk);
750 struct rt6_info *rt = (struct rt6_info *)dst;
751
752 if (!dst)
753 goto out;
754
755 /* Yes, checking route validity in not connected
756 * case is not very simple. Take into account,
757 * that we do not support routing by source, TOS,
758 * and MSG_DONTROUTE --ANK (980726)
759 *
760 * 1. ip6_rt_check(): If route was host route,
761 * check that cached destination is current.
762 * If it is network route, we still may
763 * check its validity using saved pointer
764 * to the last used address: daddr_cache.
765 * We do not want to save whole address now,
766 * (because main consumer of this service
767 * is tcp, which has not this problem),
768 * so that the last trick works only on connected
769 * sockets.
770 * 2. oif also should be the same.
771 */
772 if (ip6_rt_check(&rt->rt6i_dst, &fl->fl6_dst, np->daddr_cache) ||
773 #ifdef CONFIG_IPV6_SUBTREES
774 ip6_rt_check(&rt->rt6i_src, &fl->fl6_src, np->saddr_cache) ||
775 #endif
776 (fl->oif && fl->oif != dst->dev->ifindex)) {
777 dst_release(dst);
778 dst = NULL;
779 }
780
781 out:
782 return dst;
783 }
784
785 static int ip6_dst_lookup_tail(struct sock *sk,
786 struct dst_entry **dst, struct flowi *fl)
787 {
788 int err;
789
790 if (*dst == NULL)
791 *dst = ip6_route_output(sk, fl);
792
793 if ((err = (*dst)->error))
794 goto out_err_release;
795
796 if (ipv6_addr_any(&fl->fl6_src)) {
797 err = ipv6_get_saddr(*dst, &fl->fl6_dst, &fl->fl6_src);
798 if (err)
799 goto out_err_release;
800 }
801
802 return 0;
803
804 out_err_release:
805 dst_release(*dst);
806 *dst = NULL;
807 return err;
808 }
809
810 /**
811 * ip6_dst_lookup - perform route lookup on flow
812 * @sk: socket which provides route info
813 * @dst: pointer to dst_entry * for result
814 * @fl: flow to lookup
815 *
816 * This function performs a route lookup on the given flow.
817 *
818 * It returns zero on success, or a standard errno code on error.
819 */
820 int ip6_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi *fl)
821 {
822 *dst = NULL;
823 return ip6_dst_lookup_tail(sk, dst, fl);
824 }
825 EXPORT_SYMBOL_GPL(ip6_dst_lookup);
826
827 /**
828 * ip6_sk_dst_lookup - perform socket cached route lookup on flow
829 * @sk: socket which provides the dst cache and route info
830 * @dst: pointer to dst_entry * for result
831 * @fl: flow to lookup
832 *
833 * This function performs a route lookup on the given flow with the
834 * possibility of using the cached route in the socket if it is valid.
835 * It will take the socket dst lock when operating on the dst cache.
836 * As a result, this function can only be used in process context.
837 *
838 * It returns zero on success, or a standard errno code on error.
839 */
840 int ip6_sk_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi *fl)
841 {
842 *dst = NULL;
843 if (sk) {
844 *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie);
845 *dst = ip6_sk_dst_check(sk, *dst, fl);
846 }
847
848 return ip6_dst_lookup_tail(sk, dst, fl);
849 }
850 EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup);
851
852 static inline int ip6_ufo_append_data(struct sock *sk,
853 int getfrag(void *from, char *to, int offset, int len,
854 int odd, struct sk_buff *skb),
855 void *from, int length, int hh_len, int fragheaderlen,
856 int transhdrlen, int mtu,unsigned int flags)
857
858 {
859 struct sk_buff *skb;
860 int err;
861
862 /* There is support for UDP large send offload by network
863 * device, so create one single skb packet containing complete
864 * udp datagram
865 */
866 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) {
867 skb = sock_alloc_send_skb(sk,
868 hh_len + fragheaderlen + transhdrlen + 20,
869 (flags & MSG_DONTWAIT), &err);
870 if (skb == NULL)
871 return -ENOMEM;
872
873 /* reserve space for Hardware header */
874 skb_reserve(skb, hh_len);
875
876 /* create space for UDP/IP header */
877 skb_put(skb,fragheaderlen + transhdrlen);
878
879 /* initialize network header pointer */
880 skb->nh.raw = skb->data;
881
882 /* initialize protocol header pointer */
883 skb->h.raw = skb->data + fragheaderlen;
884
885 skb->ip_summed = CHECKSUM_PARTIAL;
886 skb->csum = 0;
887 sk->sk_sndmsg_off = 0;
888 }
889
890 err = skb_append_datato_frags(sk,skb, getfrag, from,
891 (length - transhdrlen));
892 if (!err) {
893 struct frag_hdr fhdr;
894
895 /* specify the length of each IP datagram fragment*/
896 skb_shinfo(skb)->gso_size = mtu - fragheaderlen -
897 sizeof(struct frag_hdr);
898 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
899 ipv6_select_ident(skb, &fhdr);
900 skb_shinfo(skb)->ip6_frag_id = fhdr.identification;
901 __skb_queue_tail(&sk->sk_write_queue, skb);
902
903 return 0;
904 }
905 /* There is not enough support do UPD LSO,
906 * so follow normal path
907 */
908 kfree_skb(skb);
909
910 return err;
911 }
912
913 int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
914 int offset, int len, int odd, struct sk_buff *skb),
915 void *from, int length, int transhdrlen,
916 int hlimit, int tclass, struct ipv6_txoptions *opt, struct flowi *fl,
917 struct rt6_info *rt, unsigned int flags)
918 {
919 struct inet_sock *inet = inet_sk(sk);
920 struct ipv6_pinfo *np = inet6_sk(sk);
921 struct sk_buff *skb;
922 unsigned int maxfraglen, fragheaderlen;
923 int exthdrlen;
924 int hh_len;
925 int mtu;
926 int copy;
927 int err;
928 int offset = 0;
929 int csummode = CHECKSUM_NONE;
930
931 if (flags&MSG_PROBE)
932 return 0;
933 if (skb_queue_empty(&sk->sk_write_queue)) {
934 /*
935 * setup for corking
936 */
937 if (opt) {
938 if (np->cork.opt == NULL) {
939 np->cork.opt = kmalloc(opt->tot_len,
940 sk->sk_allocation);
941 if (unlikely(np->cork.opt == NULL))
942 return -ENOBUFS;
943 } else if (np->cork.opt->tot_len < opt->tot_len) {
944 printk(KERN_DEBUG "ip6_append_data: invalid option length\n");
945 return -EINVAL;
946 }
947 memcpy(np->cork.opt, opt, opt->tot_len);
948 inet->cork.flags |= IPCORK_OPT;
949 /* need source address above miyazawa*/
950 }
951 dst_hold(&rt->u.dst);
952 np->cork.rt = rt;
953 inet->cork.fl = *fl;
954 np->cork.hop_limit = hlimit;
955 np->cork.tclass = tclass;
956 mtu = dst_mtu(rt->u.dst.path);
957 if (np->frag_size < mtu) {
958 if (np->frag_size)
959 mtu = np->frag_size;
960 }
961 inet->cork.fragsize = mtu;
962 if (dst_allfrag(rt->u.dst.path))
963 inet->cork.flags |= IPCORK_ALLFRAG;
964 inet->cork.length = 0;
965 sk->sk_sndmsg_page = NULL;
966 sk->sk_sndmsg_off = 0;
967 exthdrlen = rt->u.dst.header_len + (opt ? opt->opt_flen : 0);
968 length += exthdrlen;
969 transhdrlen += exthdrlen;
970 } else {
971 rt = np->cork.rt;
972 fl = &inet->cork.fl;
973 if (inet->cork.flags & IPCORK_OPT)
974 opt = np->cork.opt;
975 transhdrlen = 0;
976 exthdrlen = 0;
977 mtu = inet->cork.fragsize;
978 }
979
980 hh_len = LL_RESERVED_SPACE(rt->u.dst.dev);
981
982 fragheaderlen = sizeof(struct ipv6hdr) + rt->u.dst.nfheader_len + (opt ? opt->opt_nflen : 0);
983 maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - sizeof(struct frag_hdr);
984
985 if (mtu <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN) {
986 if (inet->cork.length + length > sizeof(struct ipv6hdr) + IPV6_MAXPLEN - fragheaderlen) {
987 ipv6_local_error(sk, EMSGSIZE, fl, mtu-exthdrlen);
988 return -EMSGSIZE;
989 }
990 }
991
992 /*
993 * Let's try using as much space as possible.
994 * Use MTU if total length of the message fits into the MTU.
995 * Otherwise, we need to reserve fragment header and
996 * fragment alignment (= 8-15 octects, in total).
997 *
998 * Note that we may need to "move" the data from the tail of
999 * of the buffer to the new fragment when we split
1000 * the message.
1001 *
1002 * FIXME: It may be fragmented into multiple chunks
1003 * at once if non-fragmentable extension headers
1004 * are too large.
1005 * --yoshfuji
1006 */
1007
1008 inet->cork.length += length;
1009 if (((length > mtu) && (sk->sk_protocol == IPPROTO_UDP)) &&
1010 (rt->u.dst.dev->features & NETIF_F_UFO)) {
1011
1012 err = ip6_ufo_append_data(sk, getfrag, from, length, hh_len,
1013 fragheaderlen, transhdrlen, mtu,
1014 flags);
1015 if (err)
1016 goto error;
1017 return 0;
1018 }
1019
1020 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL)
1021 goto alloc_new_skb;
1022
1023 while (length > 0) {
1024 /* Check if the remaining data fits into current packet. */
1025 copy = (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len;
1026 if (copy < length)
1027 copy = maxfraglen - skb->len;
1028
1029 if (copy <= 0) {
1030 char *data;
1031 unsigned int datalen;
1032 unsigned int fraglen;
1033 unsigned int fraggap;
1034 unsigned int alloclen;
1035 struct sk_buff *skb_prev;
1036 alloc_new_skb:
1037 skb_prev = skb;
1038
1039 /* There's no room in the current skb */
1040 if (skb_prev)
1041 fraggap = skb_prev->len - maxfraglen;
1042 else
1043 fraggap = 0;
1044
1045 /*
1046 * If remaining data exceeds the mtu,
1047 * we know we need more fragment(s).
1048 */
1049 datalen = length + fraggap;
1050 if (datalen > (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen)
1051 datalen = maxfraglen - fragheaderlen;
1052
1053 fraglen = datalen + fragheaderlen;
1054 if ((flags & MSG_MORE) &&
1055 !(rt->u.dst.dev->features&NETIF_F_SG))
1056 alloclen = mtu;
1057 else
1058 alloclen = datalen + fragheaderlen;
1059
1060 /*
1061 * The last fragment gets additional space at tail.
1062 * Note: we overallocate on fragments with MSG_MODE
1063 * because we have no idea if we're the last one.
1064 */
1065 if (datalen == length + fraggap)
1066 alloclen += rt->u.dst.trailer_len;
1067
1068 /*
1069 * We just reserve space for fragment header.
1070 * Note: this may be overallocation if the message
1071 * (without MSG_MORE) fits into the MTU.
1072 */
1073 alloclen += sizeof(struct frag_hdr);
1074
1075 if (transhdrlen) {
1076 skb = sock_alloc_send_skb(sk,
1077 alloclen + hh_len,
1078 (flags & MSG_DONTWAIT), &err);
1079 } else {
1080 skb = NULL;
1081 if (atomic_read(&sk->sk_wmem_alloc) <=
1082 2 * sk->sk_sndbuf)
1083 skb = sock_wmalloc(sk,
1084 alloclen + hh_len, 1,
1085 sk->sk_allocation);
1086 if (unlikely(skb == NULL))
1087 err = -ENOBUFS;
1088 }
1089 if (skb == NULL)
1090 goto error;
1091 /*
1092 * Fill in the control structures
1093 */
1094 skb->ip_summed = csummode;
1095 skb->csum = 0;
1096 /* reserve for fragmentation */
1097 skb_reserve(skb, hh_len+sizeof(struct frag_hdr));
1098
1099 /*
1100 * Find where to start putting bytes
1101 */
1102 data = skb_put(skb, fraglen);
1103 skb->nh.raw = data + exthdrlen;
1104 data += fragheaderlen;
1105 skb->h.raw = data + exthdrlen;
1106
1107 if (fraggap) {
1108 skb->csum = skb_copy_and_csum_bits(
1109 skb_prev, maxfraglen,
1110 data + transhdrlen, fraggap, 0);
1111 skb_prev->csum = csum_sub(skb_prev->csum,
1112 skb->csum);
1113 data += fraggap;
1114 pskb_trim_unique(skb_prev, maxfraglen);
1115 }
1116 copy = datalen - transhdrlen - fraggap;
1117 if (copy < 0) {
1118 err = -EINVAL;
1119 kfree_skb(skb);
1120 goto error;
1121 } else if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) {
1122 err = -EFAULT;
1123 kfree_skb(skb);
1124 goto error;
1125 }
1126
1127 offset += copy;
1128 length -= datalen - fraggap;
1129 transhdrlen = 0;
1130 exthdrlen = 0;
1131 csummode = CHECKSUM_NONE;
1132
1133 /*
1134 * Put the packet on the pending queue
1135 */
1136 __skb_queue_tail(&sk->sk_write_queue, skb);
1137 continue;
1138 }
1139
1140 if (copy > length)
1141 copy = length;
1142
1143 if (!(rt->u.dst.dev->features&NETIF_F_SG)) {
1144 unsigned int off;
1145
1146 off = skb->len;
1147 if (getfrag(from, skb_put(skb, copy),
1148 offset, copy, off, skb) < 0) {
1149 __skb_trim(skb, off);
1150 err = -EFAULT;
1151 goto error;
1152 }
1153 } else {
1154 int i = skb_shinfo(skb)->nr_frags;
1155 skb_frag_t *frag = &skb_shinfo(skb)->frags[i-1];
1156 struct page *page = sk->sk_sndmsg_page;
1157 int off = sk->sk_sndmsg_off;
1158 unsigned int left;
1159
1160 if (page && (left = PAGE_SIZE - off) > 0) {
1161 if (copy >= left)
1162 copy = left;
1163 if (page != frag->page) {
1164 if (i == MAX_SKB_FRAGS) {
1165 err = -EMSGSIZE;
1166 goto error;
1167 }
1168 get_page(page);
1169 skb_fill_page_desc(skb, i, page, sk->sk_sndmsg_off, 0);
1170 frag = &skb_shinfo(skb)->frags[i];
1171 }
1172 } else if(i < MAX_SKB_FRAGS) {
1173 if (copy > PAGE_SIZE)
1174 copy = PAGE_SIZE;
1175 page = alloc_pages(sk->sk_allocation, 0);
1176 if (page == NULL) {
1177 err = -ENOMEM;
1178 goto error;
1179 }
1180 sk->sk_sndmsg_page = page;
1181 sk->sk_sndmsg_off = 0;
1182
1183 skb_fill_page_desc(skb, i, page, 0, 0);
1184 frag = &skb_shinfo(skb)->frags[i];
1185 skb->truesize += PAGE_SIZE;
1186 atomic_add(PAGE_SIZE, &sk->sk_wmem_alloc);
1187 } else {
1188 err = -EMSGSIZE;
1189 goto error;
1190 }
1191 if (getfrag(from, page_address(frag->page)+frag->page_offset+frag->size, offset, copy, skb->len, skb) < 0) {
1192 err = -EFAULT;
1193 goto error;
1194 }
1195 sk->sk_sndmsg_off += copy;
1196 frag->size += copy;
1197 skb->len += copy;
1198 skb->data_len += copy;
1199 }
1200 offset += copy;
1201 length -= copy;
1202 }
1203 return 0;
1204 error:
1205 inet->cork.length -= length;
1206 IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
1207 return err;
1208 }
1209
1210 int ip6_push_pending_frames(struct sock *sk)
1211 {
1212 struct sk_buff *skb, *tmp_skb;
1213 struct sk_buff **tail_skb;
1214 struct in6_addr final_dst_buf, *final_dst = &final_dst_buf;
1215 struct inet_sock *inet = inet_sk(sk);
1216 struct ipv6_pinfo *np = inet6_sk(sk);
1217 struct ipv6hdr *hdr;
1218 struct ipv6_txoptions *opt = np->cork.opt;
1219 struct rt6_info *rt = np->cork.rt;
1220 struct flowi *fl = &inet->cork.fl;
1221 unsigned char proto = fl->proto;
1222 int err = 0;
1223
1224 if ((skb = __skb_dequeue(&sk->sk_write_queue)) == NULL)
1225 goto out;
1226 tail_skb = &(skb_shinfo(skb)->frag_list);
1227
1228 /* move skb->data to ip header from ext header */
1229 if (skb->data < skb->nh.raw)
1230 __skb_pull(skb, skb->nh.raw - skb->data);
1231 while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) {
1232 __skb_pull(tmp_skb, skb->h.raw - skb->nh.raw);
1233 *tail_skb = tmp_skb;
1234 tail_skb = &(tmp_skb->next);
1235 skb->len += tmp_skb->len;
1236 skb->data_len += tmp_skb->len;
1237 skb->truesize += tmp_skb->truesize;
1238 __sock_put(tmp_skb->sk);
1239 tmp_skb->destructor = NULL;
1240 tmp_skb->sk = NULL;
1241 }
1242
1243 ipv6_addr_copy(final_dst, &fl->fl6_dst);
1244 __skb_pull(skb, skb->h.raw - skb->nh.raw);
1245 if (opt && opt->opt_flen)
1246 ipv6_push_frag_opts(skb, opt, &proto);
1247 if (opt && opt->opt_nflen)
1248 ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst);
1249
1250 skb->nh.ipv6h = hdr = (struct ipv6hdr*) skb_push(skb, sizeof(struct ipv6hdr));
1251
1252 *(u32*)hdr = fl->fl6_flowlabel |
1253 htonl(0x60000000 | ((int)np->cork.tclass << 20));
1254
1255 if (skb->len <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN)
1256 hdr->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
1257 else
1258 hdr->payload_len = 0;
1259 hdr->hop_limit = np->cork.hop_limit;
1260 hdr->nexthdr = proto;
1261 ipv6_addr_copy(&hdr->saddr, &fl->fl6_src);
1262 ipv6_addr_copy(&hdr->daddr, final_dst);
1263
1264 skb->priority = sk->sk_priority;
1265
1266 skb->dst = dst_clone(&rt->u.dst);
1267 IP6_INC_STATS(IPSTATS_MIB_OUTREQUESTS);
1268 err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, skb->dst->dev, dst_output);
1269 if (err) {
1270 if (err > 0)
1271 err = np->recverr ? net_xmit_errno(err) : 0;
1272 if (err)
1273 goto error;
1274 }
1275
1276 out:
1277 inet->cork.flags &= ~IPCORK_OPT;
1278 kfree(np->cork.opt);
1279 np->cork.opt = NULL;
1280 if (np->cork.rt) {
1281 dst_release(&np->cork.rt->u.dst);
1282 np->cork.rt = NULL;
1283 inet->cork.flags &= ~IPCORK_ALLFRAG;
1284 }
1285 memset(&inet->cork.fl, 0, sizeof(inet->cork.fl));
1286 return err;
1287 error:
1288 goto out;
1289 }
1290
1291 void ip6_flush_pending_frames(struct sock *sk)
1292 {
1293 struct inet_sock *inet = inet_sk(sk);
1294 struct ipv6_pinfo *np = inet6_sk(sk);
1295 struct sk_buff *skb;
1296
1297 while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) {
1298 IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
1299 kfree_skb(skb);
1300 }
1301
1302 inet->cork.flags &= ~IPCORK_OPT;
1303
1304 kfree(np->cork.opt);
1305 np->cork.opt = NULL;
1306 if (np->cork.rt) {
1307 dst_release(&np->cork.rt->u.dst);
1308 np->cork.rt = NULL;
1309 inet->cork.flags &= ~IPCORK_ALLFRAG;
1310 }
1311 memset(&inet->cork.fl, 0, sizeof(inet->cork.fl));
1312 }
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