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1/*
2 * Extension Header handling for IPv6
3 * Linux INET6 implementation
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 * Andi Kleen <ak@muc.de>
8 * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
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
16/* Changes:
17 * yoshfuji : ensure not to overrun while parsing
18 * tlv options.
19 * Mitsuru KANDA @USAGI and: Remove ipv6_parse_exthdrs().
20 * YOSHIFUJI Hideaki @USAGI Register inbound extension header
21 * handlers as inet6_protocol{}.
22 */
23
24#include <linux/errno.h>
25#include <linux/types.h>
26#include <linux/socket.h>
27#include <linux/sockios.h>
28#include <linux/net.h>
29#include <linux/netdevice.h>
30#include <linux/in6.h>
31#include <linux/icmpv6.h>
32#include <linux/slab.h>
33#include <linux/export.h>
34
35#include <net/dst.h>
36#include <net/sock.h>
37#include <net/snmp.h>
38
39#include <net/ipv6.h>
40#include <net/protocol.h>
41#include <net/transp_v6.h>
42#include <net/rawv6.h>
43#include <net/ndisc.h>
44#include <net/ip6_route.h>
45#include <net/addrconf.h>
46#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
47#include <net/xfrm.h>
48#endif
49
50#include <asm/uaccess.h>
51
52int ipv6_find_tlv(struct sk_buff *skb, int offset, int type)
53{
54 const unsigned char *nh = skb_network_header(skb);
55 int packet_len = skb->tail - skb->network_header;
56 struct ipv6_opt_hdr *hdr;
57 int len;
58
59 if (offset + 2 > packet_len)
60 goto bad;
61 hdr = (struct ipv6_opt_hdr *)(nh + offset);
62 len = ((hdr->hdrlen + 1) << 3);
63
64 if (offset + len > packet_len)
65 goto bad;
66
67 offset += 2;
68 len -= 2;
69
70 while (len > 0) {
71 int opttype = nh[offset];
72 int optlen;
73
74 if (opttype == type)
75 return offset;
76
77 switch (opttype) {
78 case IPV6_TLV_PAD1:
79 optlen = 1;
80 break;
81 default:
82 optlen = nh[offset + 1] + 2;
83 if (optlen > len)
84 goto bad;
85 break;
86 }
87 offset += optlen;
88 len -= optlen;
89 }
90 /* not_found */
91 bad:
92 return -1;
93}
94EXPORT_SYMBOL_GPL(ipv6_find_tlv);
95
96/*
97 * Parsing tlv encoded headers.
98 *
99 * Parsing function "func" returns true, if parsing succeed
100 * and false, if it failed.
101 * It MUST NOT touch skb->h.
102 */
103
104struct tlvtype_proc {
105 int type;
106 bool (*func)(struct sk_buff *skb, int offset);
107};
108
109/*********************
110 Generic functions
111 *********************/
112
113/* An unknown option is detected, decide what to do */
114
115static bool ip6_tlvopt_unknown(struct sk_buff *skb, int optoff)
116{
117 switch ((skb_network_header(skb)[optoff] & 0xC0) >> 6) {
118 case 0: /* ignore */
119 return true;
120
121 case 1: /* drop packet */
122 break;
123
124 case 3: /* Send ICMP if not a multicast address and drop packet */
125 /* Actually, it is redundant check. icmp_send
126 will recheck in any case.
127 */
128 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr))
129 break;
130 case 2: /* send ICMP PARM PROB regardless and drop packet */
131 icmpv6_param_prob(skb, ICMPV6_UNK_OPTION, optoff);
132 return false;
133 }
134
135 kfree_skb(skb);
136 return false;
137}
138
139/* Parse tlv encoded option header (hop-by-hop or destination) */
140
141static bool ip6_parse_tlv(const struct tlvtype_proc *procs, struct sk_buff *skb)
142{
143 const struct tlvtype_proc *curr;
144 const unsigned char *nh = skb_network_header(skb);
145 int off = skb_network_header_len(skb);
146 int len = (skb_transport_header(skb)[1] + 1) << 3;
147 int padlen = 0;
148
149 if (skb_transport_offset(skb) + len > skb_headlen(skb))
150 goto bad;
151
152 off += 2;
153 len -= 2;
154
155 while (len > 0) {
156 int optlen = nh[off + 1] + 2;
157 int i;
158
159 switch (nh[off]) {
160 case IPV6_TLV_PAD1:
161 optlen = 1;
162 padlen++;
163 if (padlen > 7)
164 goto bad;
165 break;
166
167 case IPV6_TLV_PADN:
168 /* RFC 2460 states that the purpose of PadN is
169 * to align the containing header to multiples
170 * of 8. 7 is therefore the highest valid value.
171 * See also RFC 4942, Section 2.1.9.5.
172 */
173 padlen += optlen;
174 if (padlen > 7)
175 goto bad;
176 /* RFC 4942 recommends receiving hosts to
177 * actively check PadN payload to contain
178 * only zeroes.
179 */
180 for (i = 2; i < optlen; i++) {
181 if (nh[off + i] != 0)
182 goto bad;
183 }
184 break;
185
186 default: /* Other TLV code so scan list */
187 if (optlen > len)
188 goto bad;
189 for (curr=procs; curr->type >= 0; curr++) {
190 if (curr->type == nh[off]) {
191 /* type specific length/alignment
192 checks will be performed in the
193 func(). */
194 if (curr->func(skb, off) == false)
195 return false;
196 break;
197 }
198 }
199 if (curr->type < 0) {
200 if (ip6_tlvopt_unknown(skb, off) == 0)
201 return false;
202 }
203 padlen = 0;
204 break;
205 }
206 off += optlen;
207 len -= optlen;
208 }
209 /* This case will not be caught by above check since its padding
210 * length is smaller than 7:
211 * 1 byte NH + 1 byte Length + 6 bytes Padding
212 */
213 if ((padlen == 6) && ((off - skb_network_header_len(skb)) == 8))
214 goto bad;
215
216 if (len == 0)
217 return true;
218bad:
219 kfree_skb(skb);
220 return false;
221}
222
223/*****************************
224 Destination options header.
225 *****************************/
226
227#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
228static bool ipv6_dest_hao(struct sk_buff *skb, int optoff)
229{
230 struct ipv6_destopt_hao *hao;
231 struct inet6_skb_parm *opt = IP6CB(skb);
232 struct ipv6hdr *ipv6h = ipv6_hdr(skb);
233 struct in6_addr tmp_addr;
234 int ret;
235
236 if (opt->dsthao) {
237 LIMIT_NETDEBUG(KERN_DEBUG "hao duplicated\n");
238 goto discard;
239 }
240 opt->dsthao = opt->dst1;
241 opt->dst1 = 0;
242
243 hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) + optoff);
244
245 if (hao->length != 16) {
246 LIMIT_NETDEBUG(
247 KERN_DEBUG "hao invalid option length = %d\n", hao->length);
248 goto discard;
249 }
250
251 if (!(ipv6_addr_type(&hao->addr) & IPV6_ADDR_UNICAST)) {
252 LIMIT_NETDEBUG(
253 KERN_DEBUG "hao is not an unicast addr: %pI6\n", &hao->addr);
254 goto discard;
255 }
256
257 ret = xfrm6_input_addr(skb, (xfrm_address_t *)&ipv6h->daddr,
258 (xfrm_address_t *)&hao->addr, IPPROTO_DSTOPTS);
259 if (unlikely(ret < 0))
260 goto discard;
261
262 if (skb_cloned(skb)) {
263 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
264 goto discard;
265
266 /* update all variable using below by copied skbuff */
267 hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) +
268 optoff);
269 ipv6h = ipv6_hdr(skb);
270 }
271
272 if (skb->ip_summed == CHECKSUM_COMPLETE)
273 skb->ip_summed = CHECKSUM_NONE;
274
275 tmp_addr = ipv6h->saddr;
276 ipv6h->saddr = hao->addr;
277 hao->addr = tmp_addr;
278
279 if (skb->tstamp.tv64 == 0)
280 __net_timestamp(skb);
281
282 return true;
283
284 discard:
285 kfree_skb(skb);
286 return false;
287}
288#endif
289
290static const struct tlvtype_proc tlvprocdestopt_lst[] = {
291#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
292 {
293 .type = IPV6_TLV_HAO,
294 .func = ipv6_dest_hao,
295 },
296#endif
297 {-1, NULL}
298};
299
300static int ipv6_destopt_rcv(struct sk_buff *skb)
301{
302 struct inet6_skb_parm *opt = IP6CB(skb);
303#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
304 __u16 dstbuf;
305#endif
306 struct dst_entry *dst = skb_dst(skb);
307
308 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
309 !pskb_may_pull(skb, (skb_transport_offset(skb) +
310 ((skb_transport_header(skb)[1] + 1) << 3)))) {
311 IP6_INC_STATS_BH(dev_net(dst->dev), ip6_dst_idev(dst),
312 IPSTATS_MIB_INHDRERRORS);
313 kfree_skb(skb);
314 return -1;
315 }
316
317 opt->lastopt = opt->dst1 = skb_network_header_len(skb);
318#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
319 dstbuf = opt->dst1;
320#endif
321
322 if (ip6_parse_tlv(tlvprocdestopt_lst, skb)) {
323 skb->transport_header += (skb_transport_header(skb)[1] + 1) << 3;
324 opt = IP6CB(skb);
325#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
326 opt->nhoff = dstbuf;
327#else
328 opt->nhoff = opt->dst1;
329#endif
330 return 1;
331 }
332
333 IP6_INC_STATS_BH(dev_net(dst->dev),
334 ip6_dst_idev(dst), IPSTATS_MIB_INHDRERRORS);
335 return -1;
336}
337
338/********************************
339 Routing header.
340 ********************************/
341
342/* called with rcu_read_lock() */
343static int ipv6_rthdr_rcv(struct sk_buff *skb)
344{
345 struct inet6_skb_parm *opt = IP6CB(skb);
346 struct in6_addr *addr = NULL;
347 struct in6_addr daddr;
348 struct inet6_dev *idev;
349 int n, i;
350 struct ipv6_rt_hdr *hdr;
351 struct rt0_hdr *rthdr;
352 struct net *net = dev_net(skb->dev);
353 int accept_source_route = net->ipv6.devconf_all->accept_source_route;
354
355 idev = __in6_dev_get(skb->dev);
356 if (idev && accept_source_route > idev->cnf.accept_source_route)
357 accept_source_route = idev->cnf.accept_source_route;
358
359 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
360 !pskb_may_pull(skb, (skb_transport_offset(skb) +
361 ((skb_transport_header(skb)[1] + 1) << 3)))) {
362 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
363 IPSTATS_MIB_INHDRERRORS);
364 kfree_skb(skb);
365 return -1;
366 }
367
368 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb);
369
370 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) ||
371 skb->pkt_type != PACKET_HOST) {
372 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
373 IPSTATS_MIB_INADDRERRORS);
374 kfree_skb(skb);
375 return -1;
376 }
377
378looped_back:
379 if (hdr->segments_left == 0) {
380 switch (hdr->type) {
381#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
382 case IPV6_SRCRT_TYPE_2:
383 /* Silently discard type 2 header unless it was
384 * processed by own
385 */
386 if (!addr) {
387 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
388 IPSTATS_MIB_INADDRERRORS);
389 kfree_skb(skb);
390 return -1;
391 }
392 break;
393#endif
394 default:
395 break;
396 }
397
398 opt->lastopt = opt->srcrt = skb_network_header_len(skb);
399 skb->transport_header += (hdr->hdrlen + 1) << 3;
400 opt->dst0 = opt->dst1;
401 opt->dst1 = 0;
402 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb);
403 return 1;
404 }
405
406 switch (hdr->type) {
407#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
408 case IPV6_SRCRT_TYPE_2:
409 if (accept_source_route < 0)
410 goto unknown_rh;
411 /* Silently discard invalid RTH type 2 */
412 if (hdr->hdrlen != 2 || hdr->segments_left != 1) {
413 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
414 IPSTATS_MIB_INHDRERRORS);
415 kfree_skb(skb);
416 return -1;
417 }
418 break;
419#endif
420 default:
421 goto unknown_rh;
422 }
423
424 /*
425 * This is the routing header forwarding algorithm from
426 * RFC 2460, page 16.
427 */
428
429 n = hdr->hdrlen >> 1;
430
431 if (hdr->segments_left > n) {
432 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
433 IPSTATS_MIB_INHDRERRORS);
434 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
435 ((&hdr->segments_left) -
436 skb_network_header(skb)));
437 return -1;
438 }
439
440 /* We are about to mangle packet header. Be careful!
441 Do not damage packets queued somewhere.
442 */
443 if (skb_cloned(skb)) {
444 /* the copy is a forwarded packet */
445 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) {
446 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
447 IPSTATS_MIB_OUTDISCARDS);
448 kfree_skb(skb);
449 return -1;
450 }
451 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb);
452 }
453
454 if (skb->ip_summed == CHECKSUM_COMPLETE)
455 skb->ip_summed = CHECKSUM_NONE;
456
457 i = n - --hdr->segments_left;
458
459 rthdr = (struct rt0_hdr *) hdr;
460 addr = rthdr->addr;
461 addr += i - 1;
462
463 switch (hdr->type) {
464#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
465 case IPV6_SRCRT_TYPE_2:
466 if (xfrm6_input_addr(skb, (xfrm_address_t *)addr,
467 (xfrm_address_t *)&ipv6_hdr(skb)->saddr,
468 IPPROTO_ROUTING) < 0) {
469 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
470 IPSTATS_MIB_INADDRERRORS);
471 kfree_skb(skb);
472 return -1;
473 }
474 if (!ipv6_chk_home_addr(dev_net(skb_dst(skb)->dev), addr)) {
475 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
476 IPSTATS_MIB_INADDRERRORS);
477 kfree_skb(skb);
478 return -1;
479 }
480 break;
481#endif
482 default:
483 break;
484 }
485
486 if (ipv6_addr_is_multicast(addr)) {
487 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
488 IPSTATS_MIB_INADDRERRORS);
489 kfree_skb(skb);
490 return -1;
491 }
492
493 daddr = *addr;
494 *addr = ipv6_hdr(skb)->daddr;
495 ipv6_hdr(skb)->daddr = daddr;
496
497 skb_dst_drop(skb);
498 ip6_route_input(skb);
499 if (skb_dst(skb)->error) {
500 skb_push(skb, skb->data - skb_network_header(skb));
501 dst_input(skb);
502 return -1;
503 }
504
505 if (skb_dst(skb)->dev->flags&IFF_LOOPBACK) {
506 if (ipv6_hdr(skb)->hop_limit <= 1) {
507 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
508 IPSTATS_MIB_INHDRERRORS);
509 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
510 0);
511 kfree_skb(skb);
512 return -1;
513 }
514 ipv6_hdr(skb)->hop_limit--;
515 goto looped_back;
516 }
517
518 skb_push(skb, skb->data - skb_network_header(skb));
519 dst_input(skb);
520 return -1;
521
522unknown_rh:
523 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INHDRERRORS);
524 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
525 (&hdr->type) - skb_network_header(skb));
526 return -1;
527}
528
529static const struct inet6_protocol rthdr_protocol = {
530 .handler = ipv6_rthdr_rcv,
531 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_GSO_EXTHDR,
532};
533
534static const struct inet6_protocol destopt_protocol = {
535 .handler = ipv6_destopt_rcv,
536 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_GSO_EXTHDR,
537};
538
539static const struct inet6_protocol nodata_protocol = {
540 .handler = dst_discard,
541 .flags = INET6_PROTO_NOPOLICY,
542};
543
544int __init ipv6_exthdrs_init(void)
545{
546 int ret;
547
548 ret = inet6_add_protocol(&rthdr_protocol, IPPROTO_ROUTING);
549 if (ret)
550 goto out;
551
552 ret = inet6_add_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
553 if (ret)
554 goto out_rthdr;
555
556 ret = inet6_add_protocol(&nodata_protocol, IPPROTO_NONE);
557 if (ret)
558 goto out_destopt;
559
560out:
561 return ret;
562out_rthdr:
563 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING);
564out_destopt:
565 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
566 goto out;
567};
568
569void ipv6_exthdrs_exit(void)
570{
571 inet6_del_protocol(&nodata_protocol, IPPROTO_NONE);
572 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
573 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING);
574}
575
576/**********************************
577 Hop-by-hop options.
578 **********************************/
579
580/*
581 * Note: we cannot rely on skb_dst(skb) before we assign it in ip6_route_input().
582 */
583static inline struct inet6_dev *ipv6_skb_idev(struct sk_buff *skb)
584{
585 return skb_dst(skb) ? ip6_dst_idev(skb_dst(skb)) : __in6_dev_get(skb->dev);
586}
587
588static inline struct net *ipv6_skb_net(struct sk_buff *skb)
589{
590 return skb_dst(skb) ? dev_net(skb_dst(skb)->dev) : dev_net(skb->dev);
591}
592
593/* Router Alert as of RFC 2711 */
594
595static bool ipv6_hop_ra(struct sk_buff *skb, int optoff)
596{
597 const unsigned char *nh = skb_network_header(skb);
598
599 if (nh[optoff + 1] == 2) {
600 IP6CB(skb)->ra = optoff;
601 return true;
602 }
603 LIMIT_NETDEBUG(KERN_DEBUG "ipv6_hop_ra: wrong RA length %d\n",
604 nh[optoff + 1]);
605 kfree_skb(skb);
606 return false;
607}
608
609/* Jumbo payload */
610
611static bool ipv6_hop_jumbo(struct sk_buff *skb, int optoff)
612{
613 const unsigned char *nh = skb_network_header(skb);
614 struct net *net = ipv6_skb_net(skb);
615 u32 pkt_len;
616
617 if (nh[optoff + 1] != 4 || (optoff & 3) != 2) {
618 LIMIT_NETDEBUG(KERN_DEBUG "ipv6_hop_jumbo: wrong jumbo opt length/alignment %d\n",
619 nh[optoff+1]);
620 IP6_INC_STATS_BH(net, ipv6_skb_idev(skb),
621 IPSTATS_MIB_INHDRERRORS);
622 goto drop;
623 }
624
625 pkt_len = ntohl(*(__be32 *)(nh + optoff + 2));
626 if (pkt_len <= IPV6_MAXPLEN) {
627 IP6_INC_STATS_BH(net, ipv6_skb_idev(skb),
628 IPSTATS_MIB_INHDRERRORS);
629 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff+2);
630 return false;
631 }
632 if (ipv6_hdr(skb)->payload_len) {
633 IP6_INC_STATS_BH(net, ipv6_skb_idev(skb),
634 IPSTATS_MIB_INHDRERRORS);
635 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff);
636 return false;
637 }
638
639 if (pkt_len > skb->len - sizeof(struct ipv6hdr)) {
640 IP6_INC_STATS_BH(net, ipv6_skb_idev(skb),
641 IPSTATS_MIB_INTRUNCATEDPKTS);
642 goto drop;
643 }
644
645 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr)))
646 goto drop;
647
648 return true;
649
650drop:
651 kfree_skb(skb);
652 return false;
653}
654
655static const struct tlvtype_proc tlvprochopopt_lst[] = {
656 {
657 .type = IPV6_TLV_ROUTERALERT,
658 .func = ipv6_hop_ra,
659 },
660 {
661 .type = IPV6_TLV_JUMBO,
662 .func = ipv6_hop_jumbo,
663 },
664 { -1, }
665};
666
667int ipv6_parse_hopopts(struct sk_buff *skb)
668{
669 struct inet6_skb_parm *opt = IP6CB(skb);
670
671 /*
672 * skb_network_header(skb) is equal to skb->data, and
673 * skb_network_header_len(skb) is always equal to
674 * sizeof(struct ipv6hdr) by definition of
675 * hop-by-hop options.
676 */
677 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + 8) ||
678 !pskb_may_pull(skb, (sizeof(struct ipv6hdr) +
679 ((skb_transport_header(skb)[1] + 1) << 3)))) {
680 kfree_skb(skb);
681 return -1;
682 }
683
684 opt->hop = sizeof(struct ipv6hdr);
685 if (ip6_parse_tlv(tlvprochopopt_lst, skb)) {
686 skb->transport_header += (skb_transport_header(skb)[1] + 1) << 3;
687 opt = IP6CB(skb);
688 opt->nhoff = sizeof(struct ipv6hdr);
689 return 1;
690 }
691 return -1;
692}
693
694/*
695 * Creating outbound headers.
696 *
697 * "build" functions work when skb is filled from head to tail (datagram)
698 * "push" functions work when headers are added from tail to head (tcp)
699 *
700 * In both cases we assume, that caller reserved enough room
701 * for headers.
702 */
703
704static void ipv6_push_rthdr(struct sk_buff *skb, u8 *proto,
705 struct ipv6_rt_hdr *opt,
706 struct in6_addr **addr_p)
707{
708 struct rt0_hdr *phdr, *ihdr;
709 int hops;
710
711 ihdr = (struct rt0_hdr *) opt;
712
713 phdr = (struct rt0_hdr *) skb_push(skb, (ihdr->rt_hdr.hdrlen + 1) << 3);
714 memcpy(phdr, ihdr, sizeof(struct rt0_hdr));
715
716 hops = ihdr->rt_hdr.hdrlen >> 1;
717
718 if (hops > 1)
719 memcpy(phdr->addr, ihdr->addr + 1,
720 (hops - 1) * sizeof(struct in6_addr));
721
722 phdr->addr[hops - 1] = **addr_p;
723 *addr_p = ihdr->addr;
724
725 phdr->rt_hdr.nexthdr = *proto;
726 *proto = NEXTHDR_ROUTING;
727}
728
729static void ipv6_push_exthdr(struct sk_buff *skb, u8 *proto, u8 type, struct ipv6_opt_hdr *opt)
730{
731 struct ipv6_opt_hdr *h = (struct ipv6_opt_hdr *)skb_push(skb, ipv6_optlen(opt));
732
733 memcpy(h, opt, ipv6_optlen(opt));
734 h->nexthdr = *proto;
735 *proto = type;
736}
737
738void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
739 u8 *proto,
740 struct in6_addr **daddr)
741{
742 if (opt->srcrt) {
743 ipv6_push_rthdr(skb, proto, opt->srcrt, daddr);
744 /*
745 * IPV6_RTHDRDSTOPTS is ignored
746 * unless IPV6_RTHDR is set (RFC3542).
747 */
748 if (opt->dst0opt)
749 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst0opt);
750 }
751 if (opt->hopopt)
752 ipv6_push_exthdr(skb, proto, NEXTHDR_HOP, opt->hopopt);
753}
754EXPORT_SYMBOL(ipv6_push_nfrag_opts);
755
756void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, u8 *proto)
757{
758 if (opt->dst1opt)
759 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst1opt);
760}
761
762struct ipv6_txoptions *
763ipv6_dup_options(struct sock *sk, struct ipv6_txoptions *opt)
764{
765 struct ipv6_txoptions *opt2;
766
767 opt2 = sock_kmalloc(sk, opt->tot_len, GFP_ATOMIC);
768 if (opt2) {
769 long dif = (char *)opt2 - (char *)opt;
770 memcpy(opt2, opt, opt->tot_len);
771 if (opt2->hopopt)
772 *((char **)&opt2->hopopt) += dif;
773 if (opt2->dst0opt)
774 *((char **)&opt2->dst0opt) += dif;
775 if (opt2->dst1opt)
776 *((char **)&opt2->dst1opt) += dif;
777 if (opt2->srcrt)
778 *((char **)&opt2->srcrt) += dif;
779 }
780 return opt2;
781}
782EXPORT_SYMBOL_GPL(ipv6_dup_options);
783
784static int ipv6_renew_option(void *ohdr,
785 struct ipv6_opt_hdr __user *newopt, int newoptlen,
786 int inherit,
787 struct ipv6_opt_hdr **hdr,
788 char **p)
789{
790 if (inherit) {
791 if (ohdr) {
792 memcpy(*p, ohdr, ipv6_optlen((struct ipv6_opt_hdr *)ohdr));
793 *hdr = (struct ipv6_opt_hdr *)*p;
794 *p += CMSG_ALIGN(ipv6_optlen(*(struct ipv6_opt_hdr **)hdr));
795 }
796 } else {
797 if (newopt) {
798 if (copy_from_user(*p, newopt, newoptlen))
799 return -EFAULT;
800 *hdr = (struct ipv6_opt_hdr *)*p;
801 if (ipv6_optlen(*(struct ipv6_opt_hdr **)hdr) > newoptlen)
802 return -EINVAL;
803 *p += CMSG_ALIGN(newoptlen);
804 }
805 }
806 return 0;
807}
808
809struct ipv6_txoptions *
810ipv6_renew_options(struct sock *sk, struct ipv6_txoptions *opt,
811 int newtype,
812 struct ipv6_opt_hdr __user *newopt, int newoptlen)
813{
814 int tot_len = 0;
815 char *p;
816 struct ipv6_txoptions *opt2;
817 int err;
818
819 if (opt) {
820 if (newtype != IPV6_HOPOPTS && opt->hopopt)
821 tot_len += CMSG_ALIGN(ipv6_optlen(opt->hopopt));
822 if (newtype != IPV6_RTHDRDSTOPTS && opt->dst0opt)
823 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst0opt));
824 if (newtype != IPV6_RTHDR && opt->srcrt)
825 tot_len += CMSG_ALIGN(ipv6_optlen(opt->srcrt));
826 if (newtype != IPV6_DSTOPTS && opt->dst1opt)
827 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst1opt));
828 }
829
830 if (newopt && newoptlen)
831 tot_len += CMSG_ALIGN(newoptlen);
832
833 if (!tot_len)
834 return NULL;
835
836 tot_len += sizeof(*opt2);
837 opt2 = sock_kmalloc(sk, tot_len, GFP_ATOMIC);
838 if (!opt2)
839 return ERR_PTR(-ENOBUFS);
840
841 memset(opt2, 0, tot_len);
842
843 opt2->tot_len = tot_len;
844 p = (char *)(opt2 + 1);
845
846 err = ipv6_renew_option(opt ? opt->hopopt : NULL, newopt, newoptlen,
847 newtype != IPV6_HOPOPTS,
848 &opt2->hopopt, &p);
849 if (err)
850 goto out;
851
852 err = ipv6_renew_option(opt ? opt->dst0opt : NULL, newopt, newoptlen,
853 newtype != IPV6_RTHDRDSTOPTS,
854 &opt2->dst0opt, &p);
855 if (err)
856 goto out;
857
858 err = ipv6_renew_option(opt ? opt->srcrt : NULL, newopt, newoptlen,
859 newtype != IPV6_RTHDR,
860 (struct ipv6_opt_hdr **)&opt2->srcrt, &p);
861 if (err)
862 goto out;
863
864 err = ipv6_renew_option(opt ? opt->dst1opt : NULL, newopt, newoptlen,
865 newtype != IPV6_DSTOPTS,
866 &opt2->dst1opt, &p);
867 if (err)
868 goto out;
869
870 opt2->opt_nflen = (opt2->hopopt ? ipv6_optlen(opt2->hopopt) : 0) +
871 (opt2->dst0opt ? ipv6_optlen(opt2->dst0opt) : 0) +
872 (opt2->srcrt ? ipv6_optlen(opt2->srcrt) : 0);
873 opt2->opt_flen = (opt2->dst1opt ? ipv6_optlen(opt2->dst1opt) : 0);
874
875 return opt2;
876out:
877 sock_kfree_s(sk, opt2, opt2->tot_len);
878 return ERR_PTR(err);
879}
880
881struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space,
882 struct ipv6_txoptions *opt)
883{
884 /*
885 * ignore the dest before srcrt unless srcrt is being included.
886 * --yoshfuji
887 */
888 if (opt && opt->dst0opt && !opt->srcrt) {
889 if (opt_space != opt) {
890 memcpy(opt_space, opt, sizeof(*opt_space));
891 opt = opt_space;
892 }
893 opt->opt_nflen -= ipv6_optlen(opt->dst0opt);
894 opt->dst0opt = NULL;
895 }
896
897 return opt;
898}
899EXPORT_SYMBOL_GPL(ipv6_fixup_options);
900
901/**
902 * fl6_update_dst - update flowi destination address with info given
903 * by srcrt option, if any.
904 *
905 * @fl6: flowi6 for which daddr is to be updated
906 * @opt: struct ipv6_txoptions in which to look for srcrt opt
907 * @orig: copy of original daddr address if modified
908 *
909 * Returns NULL if no txoptions or no srcrt, otherwise returns orig
910 * and initial value of fl6->daddr set in orig
911 */
912struct in6_addr *fl6_update_dst(struct flowi6 *fl6,
913 const struct ipv6_txoptions *opt,
914 struct in6_addr *orig)
915{
916 if (!opt || !opt->srcrt)
917 return NULL;
918
919 *orig = fl6->daddr;
920 fl6->daddr = *((struct rt0_hdr *)opt->srcrt)->addr;
921 return orig;
922}
923EXPORT_SYMBOL_GPL(fl6_update_dst);
1/*
2 * Extension Header handling for IPv6
3 * Linux INET6 implementation
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 * Andi Kleen <ak@muc.de>
8 * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
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
16/* Changes:
17 * yoshfuji : ensure not to overrun while parsing
18 * tlv options.
19 * Mitsuru KANDA @USAGI and: Remove ipv6_parse_exthdrs().
20 * YOSHIFUJI Hideaki @USAGI Register inbound extension header
21 * handlers as inet6_protocol{}.
22 */
23
24#include <linux/errno.h>
25#include <linux/types.h>
26#include <linux/socket.h>
27#include <linux/sockios.h>
28#include <linux/net.h>
29#include <linux/netdevice.h>
30#include <linux/in6.h>
31#include <linux/icmpv6.h>
32#include <linux/slab.h>
33
34#include <net/dst.h>
35#include <net/sock.h>
36#include <net/snmp.h>
37
38#include <net/ipv6.h>
39#include <net/protocol.h>
40#include <net/transp_v6.h>
41#include <net/rawv6.h>
42#include <net/ndisc.h>
43#include <net/ip6_route.h>
44#include <net/addrconf.h>
45#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
46#include <net/xfrm.h>
47#endif
48
49#include <asm/uaccess.h>
50
51int ipv6_find_tlv(struct sk_buff *skb, int offset, int type)
52{
53 const unsigned char *nh = skb_network_header(skb);
54 int packet_len = skb->tail - skb->network_header;
55 struct ipv6_opt_hdr *hdr;
56 int len;
57
58 if (offset + 2 > packet_len)
59 goto bad;
60 hdr = (struct ipv6_opt_hdr *)(nh + offset);
61 len = ((hdr->hdrlen + 1) << 3);
62
63 if (offset + len > packet_len)
64 goto bad;
65
66 offset += 2;
67 len -= 2;
68
69 while (len > 0) {
70 int opttype = nh[offset];
71 int optlen;
72
73 if (opttype == type)
74 return offset;
75
76 switch (opttype) {
77 case IPV6_TLV_PAD0:
78 optlen = 1;
79 break;
80 default:
81 optlen = nh[offset + 1] + 2;
82 if (optlen > len)
83 goto bad;
84 break;
85 }
86 offset += optlen;
87 len -= optlen;
88 }
89 /* not_found */
90 bad:
91 return -1;
92}
93EXPORT_SYMBOL_GPL(ipv6_find_tlv);
94
95/*
96 * Parsing tlv encoded headers.
97 *
98 * Parsing function "func" returns 1, if parsing succeed
99 * and 0, if it failed.
100 * It MUST NOT touch skb->h.
101 */
102
103struct tlvtype_proc {
104 int type;
105 int (*func)(struct sk_buff *skb, int offset);
106};
107
108/*********************
109 Generic functions
110 *********************/
111
112/* An unknown option is detected, decide what to do */
113
114static int ip6_tlvopt_unknown(struct sk_buff *skb, int optoff)
115{
116 switch ((skb_network_header(skb)[optoff] & 0xC0) >> 6) {
117 case 0: /* ignore */
118 return 1;
119
120 case 1: /* drop packet */
121 break;
122
123 case 3: /* Send ICMP if not a multicast address and drop packet */
124 /* Actually, it is redundant check. icmp_send
125 will recheck in any case.
126 */
127 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr))
128 break;
129 case 2: /* send ICMP PARM PROB regardless and drop packet */
130 icmpv6_param_prob(skb, ICMPV6_UNK_OPTION, optoff);
131 return 0;
132 }
133
134 kfree_skb(skb);
135 return 0;
136}
137
138/* Parse tlv encoded option header (hop-by-hop or destination) */
139
140static int ip6_parse_tlv(struct tlvtype_proc *procs, struct sk_buff *skb)
141{
142 struct tlvtype_proc *curr;
143 const unsigned char *nh = skb_network_header(skb);
144 int off = skb_network_header_len(skb);
145 int len = (skb_transport_header(skb)[1] + 1) << 3;
146
147 if (skb_transport_offset(skb) + len > skb_headlen(skb))
148 goto bad;
149
150 off += 2;
151 len -= 2;
152
153 while (len > 0) {
154 int optlen = nh[off + 1] + 2;
155
156 switch (nh[off]) {
157 case IPV6_TLV_PAD0:
158 optlen = 1;
159 break;
160
161 case IPV6_TLV_PADN:
162 break;
163
164 default: /* Other TLV code so scan list */
165 if (optlen > len)
166 goto bad;
167 for (curr=procs; curr->type >= 0; curr++) {
168 if (curr->type == nh[off]) {
169 /* type specific length/alignment
170 checks will be performed in the
171 func(). */
172 if (curr->func(skb, off) == 0)
173 return 0;
174 break;
175 }
176 }
177 if (curr->type < 0) {
178 if (ip6_tlvopt_unknown(skb, off) == 0)
179 return 0;
180 }
181 break;
182 }
183 off += optlen;
184 len -= optlen;
185 }
186 if (len == 0)
187 return 1;
188bad:
189 kfree_skb(skb);
190 return 0;
191}
192
193/*****************************
194 Destination options header.
195 *****************************/
196
197#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
198static int ipv6_dest_hao(struct sk_buff *skb, int optoff)
199{
200 struct ipv6_destopt_hao *hao;
201 struct inet6_skb_parm *opt = IP6CB(skb);
202 struct ipv6hdr *ipv6h = ipv6_hdr(skb);
203 struct in6_addr tmp_addr;
204 int ret;
205
206 if (opt->dsthao) {
207 LIMIT_NETDEBUG(KERN_DEBUG "hao duplicated\n");
208 goto discard;
209 }
210 opt->dsthao = opt->dst1;
211 opt->dst1 = 0;
212
213 hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) + optoff);
214
215 if (hao->length != 16) {
216 LIMIT_NETDEBUG(
217 KERN_DEBUG "hao invalid option length = %d\n", hao->length);
218 goto discard;
219 }
220
221 if (!(ipv6_addr_type(&hao->addr) & IPV6_ADDR_UNICAST)) {
222 LIMIT_NETDEBUG(
223 KERN_DEBUG "hao is not an unicast addr: %pI6\n", &hao->addr);
224 goto discard;
225 }
226
227 ret = xfrm6_input_addr(skb, (xfrm_address_t *)&ipv6h->daddr,
228 (xfrm_address_t *)&hao->addr, IPPROTO_DSTOPTS);
229 if (unlikely(ret < 0))
230 goto discard;
231
232 if (skb_cloned(skb)) {
233 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
234 goto discard;
235
236 /* update all variable using below by copied skbuff */
237 hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) +
238 optoff);
239 ipv6h = ipv6_hdr(skb);
240 }
241
242 if (skb->ip_summed == CHECKSUM_COMPLETE)
243 skb->ip_summed = CHECKSUM_NONE;
244
245 ipv6_addr_copy(&tmp_addr, &ipv6h->saddr);
246 ipv6_addr_copy(&ipv6h->saddr, &hao->addr);
247 ipv6_addr_copy(&hao->addr, &tmp_addr);
248
249 if (skb->tstamp.tv64 == 0)
250 __net_timestamp(skb);
251
252 return 1;
253
254 discard:
255 kfree_skb(skb);
256 return 0;
257}
258#endif
259
260static struct tlvtype_proc tlvprocdestopt_lst[] = {
261#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
262 {
263 .type = IPV6_TLV_HAO,
264 .func = ipv6_dest_hao,
265 },
266#endif
267 {-1, NULL}
268};
269
270static int ipv6_destopt_rcv(struct sk_buff *skb)
271{
272 struct inet6_skb_parm *opt = IP6CB(skb);
273#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
274 __u16 dstbuf;
275#endif
276 struct dst_entry *dst;
277
278 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
279 !pskb_may_pull(skb, (skb_transport_offset(skb) +
280 ((skb_transport_header(skb)[1] + 1) << 3)))) {
281 IP6_INC_STATS_BH(dev_net(skb_dst(skb)->dev), ip6_dst_idev(skb_dst(skb)),
282 IPSTATS_MIB_INHDRERRORS);
283 kfree_skb(skb);
284 return -1;
285 }
286
287 opt->lastopt = opt->dst1 = skb_network_header_len(skb);
288#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
289 dstbuf = opt->dst1;
290#endif
291
292 dst = dst_clone(skb_dst(skb));
293 if (ip6_parse_tlv(tlvprocdestopt_lst, skb)) {
294 dst_release(dst);
295 skb->transport_header += (skb_transport_header(skb)[1] + 1) << 3;
296 opt = IP6CB(skb);
297#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
298 opt->nhoff = dstbuf;
299#else
300 opt->nhoff = opt->dst1;
301#endif
302 return 1;
303 }
304
305 IP6_INC_STATS_BH(dev_net(dst->dev),
306 ip6_dst_idev(dst), IPSTATS_MIB_INHDRERRORS);
307 dst_release(dst);
308 return -1;
309}
310
311/********************************
312 Routing header.
313 ********************************/
314
315/* called with rcu_read_lock() */
316static int ipv6_rthdr_rcv(struct sk_buff *skb)
317{
318 struct inet6_skb_parm *opt = IP6CB(skb);
319 struct in6_addr *addr = NULL;
320 struct in6_addr daddr;
321 struct inet6_dev *idev;
322 int n, i;
323 struct ipv6_rt_hdr *hdr;
324 struct rt0_hdr *rthdr;
325 struct net *net = dev_net(skb->dev);
326 int accept_source_route = net->ipv6.devconf_all->accept_source_route;
327
328 idev = __in6_dev_get(skb->dev);
329 if (idev && accept_source_route > idev->cnf.accept_source_route)
330 accept_source_route = idev->cnf.accept_source_route;
331
332 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
333 !pskb_may_pull(skb, (skb_transport_offset(skb) +
334 ((skb_transport_header(skb)[1] + 1) << 3)))) {
335 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
336 IPSTATS_MIB_INHDRERRORS);
337 kfree_skb(skb);
338 return -1;
339 }
340
341 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb);
342
343 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) ||
344 skb->pkt_type != PACKET_HOST) {
345 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
346 IPSTATS_MIB_INADDRERRORS);
347 kfree_skb(skb);
348 return -1;
349 }
350
351looped_back:
352 if (hdr->segments_left == 0) {
353 switch (hdr->type) {
354#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
355 case IPV6_SRCRT_TYPE_2:
356 /* Silently discard type 2 header unless it was
357 * processed by own
358 */
359 if (!addr) {
360 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
361 IPSTATS_MIB_INADDRERRORS);
362 kfree_skb(skb);
363 return -1;
364 }
365 break;
366#endif
367 default:
368 break;
369 }
370
371 opt->lastopt = opt->srcrt = skb_network_header_len(skb);
372 skb->transport_header += (hdr->hdrlen + 1) << 3;
373 opt->dst0 = opt->dst1;
374 opt->dst1 = 0;
375 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb);
376 return 1;
377 }
378
379 switch (hdr->type) {
380#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
381 case IPV6_SRCRT_TYPE_2:
382 if (accept_source_route < 0)
383 goto unknown_rh;
384 /* Silently discard invalid RTH type 2 */
385 if (hdr->hdrlen != 2 || hdr->segments_left != 1) {
386 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
387 IPSTATS_MIB_INHDRERRORS);
388 kfree_skb(skb);
389 return -1;
390 }
391 break;
392#endif
393 default:
394 goto unknown_rh;
395 }
396
397 /*
398 * This is the routing header forwarding algorithm from
399 * RFC 2460, page 16.
400 */
401
402 n = hdr->hdrlen >> 1;
403
404 if (hdr->segments_left > n) {
405 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
406 IPSTATS_MIB_INHDRERRORS);
407 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
408 ((&hdr->segments_left) -
409 skb_network_header(skb)));
410 return -1;
411 }
412
413 /* We are about to mangle packet header. Be careful!
414 Do not damage packets queued somewhere.
415 */
416 if (skb_cloned(skb)) {
417 /* the copy is a forwarded packet */
418 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) {
419 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
420 IPSTATS_MIB_OUTDISCARDS);
421 kfree_skb(skb);
422 return -1;
423 }
424 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb);
425 }
426
427 if (skb->ip_summed == CHECKSUM_COMPLETE)
428 skb->ip_summed = CHECKSUM_NONE;
429
430 i = n - --hdr->segments_left;
431
432 rthdr = (struct rt0_hdr *) hdr;
433 addr = rthdr->addr;
434 addr += i - 1;
435
436 switch (hdr->type) {
437#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
438 case IPV6_SRCRT_TYPE_2:
439 if (xfrm6_input_addr(skb, (xfrm_address_t *)addr,
440 (xfrm_address_t *)&ipv6_hdr(skb)->saddr,
441 IPPROTO_ROUTING) < 0) {
442 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
443 IPSTATS_MIB_INADDRERRORS);
444 kfree_skb(skb);
445 return -1;
446 }
447 if (!ipv6_chk_home_addr(dev_net(skb_dst(skb)->dev), addr)) {
448 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
449 IPSTATS_MIB_INADDRERRORS);
450 kfree_skb(skb);
451 return -1;
452 }
453 break;
454#endif
455 default:
456 break;
457 }
458
459 if (ipv6_addr_is_multicast(addr)) {
460 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
461 IPSTATS_MIB_INADDRERRORS);
462 kfree_skb(skb);
463 return -1;
464 }
465
466 ipv6_addr_copy(&daddr, addr);
467 ipv6_addr_copy(addr, &ipv6_hdr(skb)->daddr);
468 ipv6_addr_copy(&ipv6_hdr(skb)->daddr, &daddr);
469
470 skb_dst_drop(skb);
471 ip6_route_input(skb);
472 if (skb_dst(skb)->error) {
473 skb_push(skb, skb->data - skb_network_header(skb));
474 dst_input(skb);
475 return -1;
476 }
477
478 if (skb_dst(skb)->dev->flags&IFF_LOOPBACK) {
479 if (ipv6_hdr(skb)->hop_limit <= 1) {
480 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
481 IPSTATS_MIB_INHDRERRORS);
482 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
483 0);
484 kfree_skb(skb);
485 return -1;
486 }
487 ipv6_hdr(skb)->hop_limit--;
488 goto looped_back;
489 }
490
491 skb_push(skb, skb->data - skb_network_header(skb));
492 dst_input(skb);
493 return -1;
494
495unknown_rh:
496 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INHDRERRORS);
497 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
498 (&hdr->type) - skb_network_header(skb));
499 return -1;
500}
501
502static const struct inet6_protocol rthdr_protocol = {
503 .handler = ipv6_rthdr_rcv,
504 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_GSO_EXTHDR,
505};
506
507static const struct inet6_protocol destopt_protocol = {
508 .handler = ipv6_destopt_rcv,
509 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_GSO_EXTHDR,
510};
511
512static const struct inet6_protocol nodata_protocol = {
513 .handler = dst_discard,
514 .flags = INET6_PROTO_NOPOLICY,
515};
516
517int __init ipv6_exthdrs_init(void)
518{
519 int ret;
520
521 ret = inet6_add_protocol(&rthdr_protocol, IPPROTO_ROUTING);
522 if (ret)
523 goto out;
524
525 ret = inet6_add_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
526 if (ret)
527 goto out_rthdr;
528
529 ret = inet6_add_protocol(&nodata_protocol, IPPROTO_NONE);
530 if (ret)
531 goto out_destopt;
532
533out:
534 return ret;
535out_rthdr:
536 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING);
537out_destopt:
538 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
539 goto out;
540};
541
542void ipv6_exthdrs_exit(void)
543{
544 inet6_del_protocol(&nodata_protocol, IPPROTO_NONE);
545 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
546 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING);
547}
548
549/**********************************
550 Hop-by-hop options.
551 **********************************/
552
553/*
554 * Note: we cannot rely on skb_dst(skb) before we assign it in ip6_route_input().
555 */
556static inline struct inet6_dev *ipv6_skb_idev(struct sk_buff *skb)
557{
558 return skb_dst(skb) ? ip6_dst_idev(skb_dst(skb)) : __in6_dev_get(skb->dev);
559}
560
561static inline struct net *ipv6_skb_net(struct sk_buff *skb)
562{
563 return skb_dst(skb) ? dev_net(skb_dst(skb)->dev) : dev_net(skb->dev);
564}
565
566/* Router Alert as of RFC 2711 */
567
568static int ipv6_hop_ra(struct sk_buff *skb, int optoff)
569{
570 const unsigned char *nh = skb_network_header(skb);
571
572 if (nh[optoff + 1] == 2) {
573 IP6CB(skb)->ra = optoff;
574 return 1;
575 }
576 LIMIT_NETDEBUG(KERN_DEBUG "ipv6_hop_ra: wrong RA length %d\n",
577 nh[optoff + 1]);
578 kfree_skb(skb);
579 return 0;
580}
581
582/* Jumbo payload */
583
584static int ipv6_hop_jumbo(struct sk_buff *skb, int optoff)
585{
586 const unsigned char *nh = skb_network_header(skb);
587 struct net *net = ipv6_skb_net(skb);
588 u32 pkt_len;
589
590 if (nh[optoff + 1] != 4 || (optoff & 3) != 2) {
591 LIMIT_NETDEBUG(KERN_DEBUG "ipv6_hop_jumbo: wrong jumbo opt length/alignment %d\n",
592 nh[optoff+1]);
593 IP6_INC_STATS_BH(net, ipv6_skb_idev(skb),
594 IPSTATS_MIB_INHDRERRORS);
595 goto drop;
596 }
597
598 pkt_len = ntohl(*(__be32 *)(nh + optoff + 2));
599 if (pkt_len <= IPV6_MAXPLEN) {
600 IP6_INC_STATS_BH(net, ipv6_skb_idev(skb),
601 IPSTATS_MIB_INHDRERRORS);
602 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff+2);
603 return 0;
604 }
605 if (ipv6_hdr(skb)->payload_len) {
606 IP6_INC_STATS_BH(net, ipv6_skb_idev(skb),
607 IPSTATS_MIB_INHDRERRORS);
608 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff);
609 return 0;
610 }
611
612 if (pkt_len > skb->len - sizeof(struct ipv6hdr)) {
613 IP6_INC_STATS_BH(net, ipv6_skb_idev(skb),
614 IPSTATS_MIB_INTRUNCATEDPKTS);
615 goto drop;
616 }
617
618 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr)))
619 goto drop;
620
621 return 1;
622
623drop:
624 kfree_skb(skb);
625 return 0;
626}
627
628static struct tlvtype_proc tlvprochopopt_lst[] = {
629 {
630 .type = IPV6_TLV_ROUTERALERT,
631 .func = ipv6_hop_ra,
632 },
633 {
634 .type = IPV6_TLV_JUMBO,
635 .func = ipv6_hop_jumbo,
636 },
637 { -1, }
638};
639
640int ipv6_parse_hopopts(struct sk_buff *skb)
641{
642 struct inet6_skb_parm *opt = IP6CB(skb);
643
644 /*
645 * skb_network_header(skb) is equal to skb->data, and
646 * skb_network_header_len(skb) is always equal to
647 * sizeof(struct ipv6hdr) by definition of
648 * hop-by-hop options.
649 */
650 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + 8) ||
651 !pskb_may_pull(skb, (sizeof(struct ipv6hdr) +
652 ((skb_transport_header(skb)[1] + 1) << 3)))) {
653 kfree_skb(skb);
654 return -1;
655 }
656
657 opt->hop = sizeof(struct ipv6hdr);
658 if (ip6_parse_tlv(tlvprochopopt_lst, skb)) {
659 skb->transport_header += (skb_transport_header(skb)[1] + 1) << 3;
660 opt = IP6CB(skb);
661 opt->nhoff = sizeof(struct ipv6hdr);
662 return 1;
663 }
664 return -1;
665}
666
667/*
668 * Creating outbound headers.
669 *
670 * "build" functions work when skb is filled from head to tail (datagram)
671 * "push" functions work when headers are added from tail to head (tcp)
672 *
673 * In both cases we assume, that caller reserved enough room
674 * for headers.
675 */
676
677static void ipv6_push_rthdr(struct sk_buff *skb, u8 *proto,
678 struct ipv6_rt_hdr *opt,
679 struct in6_addr **addr_p)
680{
681 struct rt0_hdr *phdr, *ihdr;
682 int hops;
683
684 ihdr = (struct rt0_hdr *) opt;
685
686 phdr = (struct rt0_hdr *) skb_push(skb, (ihdr->rt_hdr.hdrlen + 1) << 3);
687 memcpy(phdr, ihdr, sizeof(struct rt0_hdr));
688
689 hops = ihdr->rt_hdr.hdrlen >> 1;
690
691 if (hops > 1)
692 memcpy(phdr->addr, ihdr->addr + 1,
693 (hops - 1) * sizeof(struct in6_addr));
694
695 ipv6_addr_copy(phdr->addr + (hops - 1), *addr_p);
696 *addr_p = ihdr->addr;
697
698 phdr->rt_hdr.nexthdr = *proto;
699 *proto = NEXTHDR_ROUTING;
700}
701
702static void ipv6_push_exthdr(struct sk_buff *skb, u8 *proto, u8 type, struct ipv6_opt_hdr *opt)
703{
704 struct ipv6_opt_hdr *h = (struct ipv6_opt_hdr *)skb_push(skb, ipv6_optlen(opt));
705
706 memcpy(h, opt, ipv6_optlen(opt));
707 h->nexthdr = *proto;
708 *proto = type;
709}
710
711void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
712 u8 *proto,
713 struct in6_addr **daddr)
714{
715 if (opt->srcrt) {
716 ipv6_push_rthdr(skb, proto, opt->srcrt, daddr);
717 /*
718 * IPV6_RTHDRDSTOPTS is ignored
719 * unless IPV6_RTHDR is set (RFC3542).
720 */
721 if (opt->dst0opt)
722 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst0opt);
723 }
724 if (opt->hopopt)
725 ipv6_push_exthdr(skb, proto, NEXTHDR_HOP, opt->hopopt);
726}
727
728EXPORT_SYMBOL(ipv6_push_nfrag_opts);
729
730void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, u8 *proto)
731{
732 if (opt->dst1opt)
733 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst1opt);
734}
735
736struct ipv6_txoptions *
737ipv6_dup_options(struct sock *sk, struct ipv6_txoptions *opt)
738{
739 struct ipv6_txoptions *opt2;
740
741 opt2 = sock_kmalloc(sk, opt->tot_len, GFP_ATOMIC);
742 if (opt2) {
743 long dif = (char*)opt2 - (char*)opt;
744 memcpy(opt2, opt, opt->tot_len);
745 if (opt2->hopopt)
746 *((char**)&opt2->hopopt) += dif;
747 if (opt2->dst0opt)
748 *((char**)&opt2->dst0opt) += dif;
749 if (opt2->dst1opt)
750 *((char**)&opt2->dst1opt) += dif;
751 if (opt2->srcrt)
752 *((char**)&opt2->srcrt) += dif;
753 }
754 return opt2;
755}
756
757EXPORT_SYMBOL_GPL(ipv6_dup_options);
758
759static int ipv6_renew_option(void *ohdr,
760 struct ipv6_opt_hdr __user *newopt, int newoptlen,
761 int inherit,
762 struct ipv6_opt_hdr **hdr,
763 char **p)
764{
765 if (inherit) {
766 if (ohdr) {
767 memcpy(*p, ohdr, ipv6_optlen((struct ipv6_opt_hdr *)ohdr));
768 *hdr = (struct ipv6_opt_hdr *)*p;
769 *p += CMSG_ALIGN(ipv6_optlen(*(struct ipv6_opt_hdr **)hdr));
770 }
771 } else {
772 if (newopt) {
773 if (copy_from_user(*p, newopt, newoptlen))
774 return -EFAULT;
775 *hdr = (struct ipv6_opt_hdr *)*p;
776 if (ipv6_optlen(*(struct ipv6_opt_hdr **)hdr) > newoptlen)
777 return -EINVAL;
778 *p += CMSG_ALIGN(newoptlen);
779 }
780 }
781 return 0;
782}
783
784struct ipv6_txoptions *
785ipv6_renew_options(struct sock *sk, struct ipv6_txoptions *opt,
786 int newtype,
787 struct ipv6_opt_hdr __user *newopt, int newoptlen)
788{
789 int tot_len = 0;
790 char *p;
791 struct ipv6_txoptions *opt2;
792 int err;
793
794 if (opt) {
795 if (newtype != IPV6_HOPOPTS && opt->hopopt)
796 tot_len += CMSG_ALIGN(ipv6_optlen(opt->hopopt));
797 if (newtype != IPV6_RTHDRDSTOPTS && opt->dst0opt)
798 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst0opt));
799 if (newtype != IPV6_RTHDR && opt->srcrt)
800 tot_len += CMSG_ALIGN(ipv6_optlen(opt->srcrt));
801 if (newtype != IPV6_DSTOPTS && opt->dst1opt)
802 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst1opt));
803 }
804
805 if (newopt && newoptlen)
806 tot_len += CMSG_ALIGN(newoptlen);
807
808 if (!tot_len)
809 return NULL;
810
811 tot_len += sizeof(*opt2);
812 opt2 = sock_kmalloc(sk, tot_len, GFP_ATOMIC);
813 if (!opt2)
814 return ERR_PTR(-ENOBUFS);
815
816 memset(opt2, 0, tot_len);
817
818 opt2->tot_len = tot_len;
819 p = (char *)(opt2 + 1);
820
821 err = ipv6_renew_option(opt ? opt->hopopt : NULL, newopt, newoptlen,
822 newtype != IPV6_HOPOPTS,
823 &opt2->hopopt, &p);
824 if (err)
825 goto out;
826
827 err = ipv6_renew_option(opt ? opt->dst0opt : NULL, newopt, newoptlen,
828 newtype != IPV6_RTHDRDSTOPTS,
829 &opt2->dst0opt, &p);
830 if (err)
831 goto out;
832
833 err = ipv6_renew_option(opt ? opt->srcrt : NULL, newopt, newoptlen,
834 newtype != IPV6_RTHDR,
835 (struct ipv6_opt_hdr **)&opt2->srcrt, &p);
836 if (err)
837 goto out;
838
839 err = ipv6_renew_option(opt ? opt->dst1opt : NULL, newopt, newoptlen,
840 newtype != IPV6_DSTOPTS,
841 &opt2->dst1opt, &p);
842 if (err)
843 goto out;
844
845 opt2->opt_nflen = (opt2->hopopt ? ipv6_optlen(opt2->hopopt) : 0) +
846 (opt2->dst0opt ? ipv6_optlen(opt2->dst0opt) : 0) +
847 (opt2->srcrt ? ipv6_optlen(opt2->srcrt) : 0);
848 opt2->opt_flen = (opt2->dst1opt ? ipv6_optlen(opt2->dst1opt) : 0);
849
850 return opt2;
851out:
852 sock_kfree_s(sk, opt2, opt2->tot_len);
853 return ERR_PTR(err);
854}
855
856struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space,
857 struct ipv6_txoptions *opt)
858{
859 /*
860 * ignore the dest before srcrt unless srcrt is being included.
861 * --yoshfuji
862 */
863 if (opt && opt->dst0opt && !opt->srcrt) {
864 if (opt_space != opt) {
865 memcpy(opt_space, opt, sizeof(*opt_space));
866 opt = opt_space;
867 }
868 opt->opt_nflen -= ipv6_optlen(opt->dst0opt);
869 opt->dst0opt = NULL;
870 }
871
872 return opt;
873}
874
875/**
876 * fl6_update_dst - update flowi destination address with info given
877 * by srcrt option, if any.
878 *
879 * @fl6: flowi6 for which daddr is to be updated
880 * @opt: struct ipv6_txoptions in which to look for srcrt opt
881 * @orig: copy of original daddr address if modified
882 *
883 * Returns NULL if no txoptions or no srcrt, otherwise returns orig
884 * and initial value of fl6->daddr set in orig
885 */
886struct in6_addr *fl6_update_dst(struct flowi6 *fl6,
887 const struct ipv6_txoptions *opt,
888 struct in6_addr *orig)
889{
890 if (!opt || !opt->srcrt)
891 return NULL;
892
893 ipv6_addr_copy(orig, &fl6->daddr);
894 ipv6_addr_copy(&fl6->daddr, ((struct rt0_hdr *)opt->srcrt)->addr);
895 return orig;
896}
897
898EXPORT_SYMBOL_GPL(fl6_update_dst);