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ipv6: replace min/casting by min_t
[deliverable/linux.git] / net / ipv6 / exthdrs.c
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CommitLineData
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 IS_ENABLED(CONFIG_IPV6_MIP6)
47#include <net/xfrm.h>
48#endif
49
50#include <asm/uaccess.h>
51
52/*
53 * Parsing tlv encoded headers.
54 *
55 * Parsing function "func" returns true, if parsing succeed
56 * and false, if it failed.
57 * It MUST NOT touch skb->h.
58 */
59
60struct tlvtype_proc {
61 int type;
62 bool (*func)(struct sk_buff *skb, int offset);
63};
64
65/*********************
66 Generic functions
67 *********************/
68
69/* An unknown option is detected, decide what to do */
70
71static bool ip6_tlvopt_unknown(struct sk_buff *skb, int optoff)
72{
73 switch ((skb_network_header(skb)[optoff] & 0xC0) >> 6) {
74 case 0: /* ignore */
75 return true;
76
77 case 1: /* drop packet */
78 break;
79
80 case 3: /* Send ICMP if not a multicast address and drop packet */
81 /* Actually, it is redundant check. icmp_send
82 will recheck in any case.
83 */
84 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr))
85 break;
86 case 2: /* send ICMP PARM PROB regardless and drop packet */
87 icmpv6_param_prob(skb, ICMPV6_UNK_OPTION, optoff);
88 return false;
89 }
90
91 kfree_skb(skb);
92 return false;
93}
94
95/* Parse tlv encoded option header (hop-by-hop or destination) */
96
97static bool ip6_parse_tlv(const struct tlvtype_proc *procs, struct sk_buff *skb)
98{
99 const struct tlvtype_proc *curr;
100 const unsigned char *nh = skb_network_header(skb);
101 int off = skb_network_header_len(skb);
102 int len = (skb_transport_header(skb)[1] + 1) << 3;
103 int padlen = 0;
104
105 if (skb_transport_offset(skb) + len > skb_headlen(skb))
106 goto bad;
107
108 off += 2;
109 len -= 2;
110
111 while (len > 0) {
112 int optlen = nh[off + 1] + 2;
113 int i;
114
115 switch (nh[off]) {
116 case IPV6_TLV_PAD1:
117 optlen = 1;
118 padlen++;
119 if (padlen > 7)
120 goto bad;
121 break;
122
123 case IPV6_TLV_PADN:
124 /* RFC 2460 states that the purpose of PadN is
125 * to align the containing header to multiples
126 * of 8. 7 is therefore the highest valid value.
127 * See also RFC 4942, Section 2.1.9.5.
128 */
129 padlen += optlen;
130 if (padlen > 7)
131 goto bad;
132 /* RFC 4942 recommends receiving hosts to
133 * actively check PadN payload to contain
134 * only zeroes.
135 */
136 for (i = 2; i < optlen; i++) {
137 if (nh[off + i] != 0)
138 goto bad;
139 }
140 break;
141
142 default: /* Other TLV code so scan list */
143 if (optlen > len)
144 goto bad;
145 for (curr = procs; curr->type >= 0; curr++) {
146 if (curr->type == nh[off]) {
147 /* type specific length/alignment
148 checks will be performed in the
149 func(). */
150 if (curr->func(skb, off) == false)
151 return false;
152 break;
153 }
154 }
155 if (curr->type < 0) {
156 if (ip6_tlvopt_unknown(skb, off) == 0)
157 return false;
158 }
159 padlen = 0;
160 break;
161 }
162 off += optlen;
163 len -= optlen;
164 }
165
166 if (len == 0)
167 return true;
168bad:
169 kfree_skb(skb);
170 return false;
171}
172
173/*****************************
174 Destination options header.
175 *****************************/
176
177#if IS_ENABLED(CONFIG_IPV6_MIP6)
178static bool ipv6_dest_hao(struct sk_buff *skb, int optoff)
179{
180 struct ipv6_destopt_hao *hao;
181 struct inet6_skb_parm *opt = IP6CB(skb);
182 struct ipv6hdr *ipv6h = ipv6_hdr(skb);
183 struct in6_addr tmp_addr;
184 int ret;
185
186 if (opt->dsthao) {
187 LIMIT_NETDEBUG(KERN_DEBUG "hao duplicated\n");
188 goto discard;
189 }
190 opt->dsthao = opt->dst1;
191 opt->dst1 = 0;
192
193 hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) + optoff);
194
195 if (hao->length != 16) {
196 LIMIT_NETDEBUG(
197 KERN_DEBUG "hao invalid option length = %d\n", hao->length);
198 goto discard;
199 }
200
201 if (!(ipv6_addr_type(&hao->addr) & IPV6_ADDR_UNICAST)) {
202 LIMIT_NETDEBUG(
203 KERN_DEBUG "hao is not an unicast addr: %pI6\n", &hao->addr);
204 goto discard;
205 }
206
207 ret = xfrm6_input_addr(skb, (xfrm_address_t *)&ipv6h->daddr,
208 (xfrm_address_t *)&hao->addr, IPPROTO_DSTOPTS);
209 if (unlikely(ret < 0))
210 goto discard;
211
212 if (skb_cloned(skb)) {
213 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
214 goto discard;
215
216 /* update all variable using below by copied skbuff */
217 hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) +
218 optoff);
219 ipv6h = ipv6_hdr(skb);
220 }
221
222 if (skb->ip_summed == CHECKSUM_COMPLETE)
223 skb->ip_summed = CHECKSUM_NONE;
224
225 tmp_addr = ipv6h->saddr;
226 ipv6h->saddr = hao->addr;
227 hao->addr = tmp_addr;
228
229 if (skb->tstamp.tv64 == 0)
230 __net_timestamp(skb);
231
232 return true;
233
234 discard:
235 kfree_skb(skb);
236 return false;
237}
238#endif
239
240static const struct tlvtype_proc tlvprocdestopt_lst[] = {
241#if IS_ENABLED(CONFIG_IPV6_MIP6)
242 {
243 .type = IPV6_TLV_HAO,
244 .func = ipv6_dest_hao,
245 },
246#endif
247 {-1, NULL}
248};
249
250static int ipv6_destopt_rcv(struct sk_buff *skb)
251{
252 struct inet6_skb_parm *opt = IP6CB(skb);
253#if IS_ENABLED(CONFIG_IPV6_MIP6)
254 __u16 dstbuf;
255#endif
256 struct dst_entry *dst = skb_dst(skb);
257
258 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
259 !pskb_may_pull(skb, (skb_transport_offset(skb) +
260 ((skb_transport_header(skb)[1] + 1) << 3)))) {
261 IP6_INC_STATS_BH(dev_net(dst->dev), ip6_dst_idev(dst),
262 IPSTATS_MIB_INHDRERRORS);
263 kfree_skb(skb);
264 return -1;
265 }
266
267 opt->lastopt = opt->dst1 = skb_network_header_len(skb);
268#if IS_ENABLED(CONFIG_IPV6_MIP6)
269 dstbuf = opt->dst1;
270#endif
271
272 if (ip6_parse_tlv(tlvprocdestopt_lst, skb)) {
273 skb->transport_header += (skb_transport_header(skb)[1] + 1) << 3;
274 opt = IP6CB(skb);
275#if IS_ENABLED(CONFIG_IPV6_MIP6)
276 opt->nhoff = dstbuf;
277#else
278 opt->nhoff = opt->dst1;
279#endif
280 return 1;
281 }
282
283 IP6_INC_STATS_BH(dev_net(dst->dev),
284 ip6_dst_idev(dst), IPSTATS_MIB_INHDRERRORS);
285 return -1;
286}
287
288/********************************
289 Routing header.
290 ********************************/
291
292/* called with rcu_read_lock() */
293static int ipv6_rthdr_rcv(struct sk_buff *skb)
294{
295 struct inet6_skb_parm *opt = IP6CB(skb);
296 struct in6_addr *addr = NULL;
297 struct in6_addr daddr;
298 struct inet6_dev *idev;
299 int n, i;
300 struct ipv6_rt_hdr *hdr;
301 struct rt0_hdr *rthdr;
302 struct net *net = dev_net(skb->dev);
303 int accept_source_route = net->ipv6.devconf_all->accept_source_route;
304
305 idev = __in6_dev_get(skb->dev);
306 if (idev && accept_source_route > idev->cnf.accept_source_route)
307 accept_source_route = idev->cnf.accept_source_route;
308
309 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
310 !pskb_may_pull(skb, (skb_transport_offset(skb) +
311 ((skb_transport_header(skb)[1] + 1) << 3)))) {
312 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
313 IPSTATS_MIB_INHDRERRORS);
314 kfree_skb(skb);
315 return -1;
316 }
317
318 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb);
319
320 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) ||
321 skb->pkt_type != PACKET_HOST) {
322 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
323 IPSTATS_MIB_INADDRERRORS);
324 kfree_skb(skb);
325 return -1;
326 }
327
328looped_back:
329 if (hdr->segments_left == 0) {
330 switch (hdr->type) {
331#if IS_ENABLED(CONFIG_IPV6_MIP6)
332 case IPV6_SRCRT_TYPE_2:
333 /* Silently discard type 2 header unless it was
334 * processed by own
335 */
336 if (!addr) {
337 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
338 IPSTATS_MIB_INADDRERRORS);
339 kfree_skb(skb);
340 return -1;
341 }
342 break;
343#endif
344 default:
345 break;
346 }
347
348 opt->lastopt = opt->srcrt = skb_network_header_len(skb);
349 skb->transport_header += (hdr->hdrlen + 1) << 3;
350 opt->dst0 = opt->dst1;
351 opt->dst1 = 0;
352 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb);
353 return 1;
354 }
355
356 switch (hdr->type) {
357#if IS_ENABLED(CONFIG_IPV6_MIP6)
358 case IPV6_SRCRT_TYPE_2:
359 if (accept_source_route < 0)
360 goto unknown_rh;
361 /* Silently discard invalid RTH type 2 */
362 if (hdr->hdrlen != 2 || hdr->segments_left != 1) {
363 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
364 IPSTATS_MIB_INHDRERRORS);
365 kfree_skb(skb);
366 return -1;
367 }
368 break;
369#endif
370 default:
371 goto unknown_rh;
372 }
373
374 /*
375 * This is the routing header forwarding algorithm from
376 * RFC 2460, page 16.
377 */
378
379 n = hdr->hdrlen >> 1;
380
381 if (hdr->segments_left > n) {
382 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
383 IPSTATS_MIB_INHDRERRORS);
384 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
385 ((&hdr->segments_left) -
386 skb_network_header(skb)));
387 return -1;
388 }
389
390 /* We are about to mangle packet header. Be careful!
391 Do not damage packets queued somewhere.
392 */
393 if (skb_cloned(skb)) {
394 /* the copy is a forwarded packet */
395 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) {
396 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
397 IPSTATS_MIB_OUTDISCARDS);
398 kfree_skb(skb);
399 return -1;
400 }
401 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb);
402 }
403
404 if (skb->ip_summed == CHECKSUM_COMPLETE)
405 skb->ip_summed = CHECKSUM_NONE;
406
407 i = n - --hdr->segments_left;
408
409 rthdr = (struct rt0_hdr *) hdr;
410 addr = rthdr->addr;
411 addr += i - 1;
412
413 switch (hdr->type) {
414#if IS_ENABLED(CONFIG_IPV6_MIP6)
415 case IPV6_SRCRT_TYPE_2:
416 if (xfrm6_input_addr(skb, (xfrm_address_t *)addr,
417 (xfrm_address_t *)&ipv6_hdr(skb)->saddr,
418 IPPROTO_ROUTING) < 0) {
419 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
420 IPSTATS_MIB_INADDRERRORS);
421 kfree_skb(skb);
422 return -1;
423 }
424 if (!ipv6_chk_home_addr(dev_net(skb_dst(skb)->dev), addr)) {
425 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
426 IPSTATS_MIB_INADDRERRORS);
427 kfree_skb(skb);
428 return -1;
429 }
430 break;
431#endif
432 default:
433 break;
434 }
435
436 if (ipv6_addr_is_multicast(addr)) {
437 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
438 IPSTATS_MIB_INADDRERRORS);
439 kfree_skb(skb);
440 return -1;
441 }
442
443 daddr = *addr;
444 *addr = ipv6_hdr(skb)->daddr;
445 ipv6_hdr(skb)->daddr = daddr;
446
447 skb_dst_drop(skb);
448 ip6_route_input(skb);
449 if (skb_dst(skb)->error) {
450 skb_push(skb, skb->data - skb_network_header(skb));
451 dst_input(skb);
452 return -1;
453 }
454
455 if (skb_dst(skb)->dev->flags&IFF_LOOPBACK) {
456 if (ipv6_hdr(skb)->hop_limit <= 1) {
457 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
458 IPSTATS_MIB_INHDRERRORS);
459 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
460 0);
461 kfree_skb(skb);
462 return -1;
463 }
464 ipv6_hdr(skb)->hop_limit--;
465 goto looped_back;
466 }
467
468 skb_push(skb, skb->data - skb_network_header(skb));
469 dst_input(skb);
470 return -1;
471
472unknown_rh:
473 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INHDRERRORS);
474 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
475 (&hdr->type) - skb_network_header(skb));
476 return -1;
477}
478
479static const struct inet6_protocol rthdr_protocol = {
480 .handler = ipv6_rthdr_rcv,
481 .flags = INET6_PROTO_NOPOLICY,
482};
483
484static const struct inet6_protocol destopt_protocol = {
485 .handler = ipv6_destopt_rcv,
486 .flags = INET6_PROTO_NOPOLICY,
487};
488
489static const struct inet6_protocol nodata_protocol = {
490 .handler = dst_discard,
491 .flags = INET6_PROTO_NOPOLICY,
492};
493
494int __init ipv6_exthdrs_init(void)
495{
496 int ret;
497
498 ret = inet6_add_protocol(&rthdr_protocol, IPPROTO_ROUTING);
499 if (ret)
500 goto out;
501
502 ret = inet6_add_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
503 if (ret)
504 goto out_rthdr;
505
506 ret = inet6_add_protocol(&nodata_protocol, IPPROTO_NONE);
507 if (ret)
508 goto out_destopt;
509
510out:
511 return ret;
512out_destopt:
513 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
514out_rthdr:
515 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING);
516 goto out;
517};
518
519void ipv6_exthdrs_exit(void)
520{
521 inet6_del_protocol(&nodata_protocol, IPPROTO_NONE);
522 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
523 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING);
524}
525
526/**********************************
527 Hop-by-hop options.
528 **********************************/
529
530/*
531 * Note: we cannot rely on skb_dst(skb) before we assign it in ip6_route_input().
532 */
533static inline struct inet6_dev *ipv6_skb_idev(struct sk_buff *skb)
534{
535 return skb_dst(skb) ? ip6_dst_idev(skb_dst(skb)) : __in6_dev_get(skb->dev);
536}
537
538static inline struct net *ipv6_skb_net(struct sk_buff *skb)
539{
540 return skb_dst(skb) ? dev_net(skb_dst(skb)->dev) : dev_net(skb->dev);
541}
542
543/* Router Alert as of RFC 2711 */
544
545static bool ipv6_hop_ra(struct sk_buff *skb, int optoff)
546{
547 const unsigned char *nh = skb_network_header(skb);
548
549 if (nh[optoff + 1] == 2) {
550 IP6CB(skb)->flags |= IP6SKB_ROUTERALERT;
551 memcpy(&IP6CB(skb)->ra, nh + optoff + 2, sizeof(IP6CB(skb)->ra));
552 return true;
553 }
554 LIMIT_NETDEBUG(KERN_DEBUG "ipv6_hop_ra: wrong RA length %d\n",
555 nh[optoff + 1]);
556 kfree_skb(skb);
557 return false;
558}
559
560/* Jumbo payload */
561
562static bool ipv6_hop_jumbo(struct sk_buff *skb, int optoff)
563{
564 const unsigned char *nh = skb_network_header(skb);
565 struct net *net = ipv6_skb_net(skb);
566 u32 pkt_len;
567
568 if (nh[optoff + 1] != 4 || (optoff & 3) != 2) {
569 LIMIT_NETDEBUG(KERN_DEBUG "ipv6_hop_jumbo: wrong jumbo opt length/alignment %d\n",
570 nh[optoff+1]);
571 IP6_INC_STATS_BH(net, ipv6_skb_idev(skb),
572 IPSTATS_MIB_INHDRERRORS);
573 goto drop;
574 }
575
576 pkt_len = ntohl(*(__be32 *)(nh + optoff + 2));
577 if (pkt_len <= IPV6_MAXPLEN) {
578 IP6_INC_STATS_BH(net, ipv6_skb_idev(skb),
579 IPSTATS_MIB_INHDRERRORS);
580 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff+2);
581 return false;
582 }
583 if (ipv6_hdr(skb)->payload_len) {
584 IP6_INC_STATS_BH(net, ipv6_skb_idev(skb),
585 IPSTATS_MIB_INHDRERRORS);
586 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff);
587 return false;
588 }
589
590 if (pkt_len > skb->len - sizeof(struct ipv6hdr)) {
591 IP6_INC_STATS_BH(net, ipv6_skb_idev(skb),
592 IPSTATS_MIB_INTRUNCATEDPKTS);
593 goto drop;
594 }
595
596 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr)))
597 goto drop;
598
599 return true;
600
601drop:
602 kfree_skb(skb);
603 return false;
604}
605
606static const struct tlvtype_proc tlvprochopopt_lst[] = {
607 {
608 .type = IPV6_TLV_ROUTERALERT,
609 .func = ipv6_hop_ra,
610 },
611 {
612 .type = IPV6_TLV_JUMBO,
613 .func = ipv6_hop_jumbo,
614 },
615 { -1, }
616};
617
618int ipv6_parse_hopopts(struct sk_buff *skb)
619{
620 struct inet6_skb_parm *opt = IP6CB(skb);
621
622 /*
623 * skb_network_header(skb) is equal to skb->data, and
624 * skb_network_header_len(skb) is always equal to
625 * sizeof(struct ipv6hdr) by definition of
626 * hop-by-hop options.
627 */
628 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + 8) ||
629 !pskb_may_pull(skb, (sizeof(struct ipv6hdr) +
630 ((skb_transport_header(skb)[1] + 1) << 3)))) {
631 kfree_skb(skb);
632 return -1;
633 }
634
635 opt->hop = sizeof(struct ipv6hdr);
636 if (ip6_parse_tlv(tlvprochopopt_lst, skb)) {
637 skb->transport_header += (skb_transport_header(skb)[1] + 1) << 3;
638 opt = IP6CB(skb);
639 opt->nhoff = sizeof(struct ipv6hdr);
640 return 1;
641 }
642 return -1;
643}
644
645/*
646 * Creating outbound headers.
647 *
648 * "build" functions work when skb is filled from head to tail (datagram)
649 * "push" functions work when headers are added from tail to head (tcp)
650 *
651 * In both cases we assume, that caller reserved enough room
652 * for headers.
653 */
654
655static void ipv6_push_rthdr(struct sk_buff *skb, u8 *proto,
656 struct ipv6_rt_hdr *opt,
657 struct in6_addr **addr_p)
658{
659 struct rt0_hdr *phdr, *ihdr;
660 int hops;
661
662 ihdr = (struct rt0_hdr *) opt;
663
664 phdr = (struct rt0_hdr *) skb_push(skb, (ihdr->rt_hdr.hdrlen + 1) << 3);
665 memcpy(phdr, ihdr, sizeof(struct rt0_hdr));
666
667 hops = ihdr->rt_hdr.hdrlen >> 1;
668
669 if (hops > 1)
670 memcpy(phdr->addr, ihdr->addr + 1,
671 (hops - 1) * sizeof(struct in6_addr));
672
673 phdr->addr[hops - 1] = **addr_p;
674 *addr_p = ihdr->addr;
675
676 phdr->rt_hdr.nexthdr = *proto;
677 *proto = NEXTHDR_ROUTING;
678}
679
680static void ipv6_push_exthdr(struct sk_buff *skb, u8 *proto, u8 type, struct ipv6_opt_hdr *opt)
681{
682 struct ipv6_opt_hdr *h = (struct ipv6_opt_hdr *)skb_push(skb, ipv6_optlen(opt));
683
684 memcpy(h, opt, ipv6_optlen(opt));
685 h->nexthdr = *proto;
686 *proto = type;
687}
688
689void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
690 u8 *proto,
691 struct in6_addr **daddr)
692{
693 if (opt->srcrt) {
694 ipv6_push_rthdr(skb, proto, opt->srcrt, daddr);
695 /*
696 * IPV6_RTHDRDSTOPTS is ignored
697 * unless IPV6_RTHDR is set (RFC3542).
698 */
699 if (opt->dst0opt)
700 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst0opt);
701 }
702 if (opt->hopopt)
703 ipv6_push_exthdr(skb, proto, NEXTHDR_HOP, opt->hopopt);
704}
705EXPORT_SYMBOL(ipv6_push_nfrag_opts);
706
707void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, u8 *proto)
708{
709 if (opt->dst1opt)
710 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst1opt);
711}
712
713struct ipv6_txoptions *
714ipv6_dup_options(struct sock *sk, struct ipv6_txoptions *opt)
715{
716 struct ipv6_txoptions *opt2;
717
718 opt2 = sock_kmalloc(sk, opt->tot_len, GFP_ATOMIC);
719 if (opt2) {
720 long dif = (char *)opt2 - (char *)opt;
721 memcpy(opt2, opt, opt->tot_len);
722 if (opt2->hopopt)
723 *((char **)&opt2->hopopt) += dif;
724 if (opt2->dst0opt)
725 *((char **)&opt2->dst0opt) += dif;
726 if (opt2->dst1opt)
727 *((char **)&opt2->dst1opt) += dif;
728 if (opt2->srcrt)
729 *((char **)&opt2->srcrt) += dif;
730 }
731 return opt2;
732}
733EXPORT_SYMBOL_GPL(ipv6_dup_options);
734
735static int ipv6_renew_option(void *ohdr,
736 struct ipv6_opt_hdr __user *newopt, int newoptlen,
737 int inherit,
738 struct ipv6_opt_hdr **hdr,
739 char **p)
740{
741 if (inherit) {
742 if (ohdr) {
743 memcpy(*p, ohdr, ipv6_optlen((struct ipv6_opt_hdr *)ohdr));
744 *hdr = (struct ipv6_opt_hdr *)*p;
745 *p += CMSG_ALIGN(ipv6_optlen(*hdr));
746 }
747 } else {
748 if (newopt) {
749 if (copy_from_user(*p, newopt, newoptlen))
750 return -EFAULT;
751 *hdr = (struct ipv6_opt_hdr *)*p;
752 if (ipv6_optlen(*hdr) > newoptlen)
753 return -EINVAL;
754 *p += CMSG_ALIGN(newoptlen);
755 }
756 }
757 return 0;
758}
759
760struct ipv6_txoptions *
761ipv6_renew_options(struct sock *sk, struct ipv6_txoptions *opt,
762 int newtype,
763 struct ipv6_opt_hdr __user *newopt, int newoptlen)
764{
765 int tot_len = 0;
766 char *p;
767 struct ipv6_txoptions *opt2;
768 int err;
769
770 if (opt) {
771 if (newtype != IPV6_HOPOPTS && opt->hopopt)
772 tot_len += CMSG_ALIGN(ipv6_optlen(opt->hopopt));
773 if (newtype != IPV6_RTHDRDSTOPTS && opt->dst0opt)
774 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst0opt));
775 if (newtype != IPV6_RTHDR && opt->srcrt)
776 tot_len += CMSG_ALIGN(ipv6_optlen(opt->srcrt));
777 if (newtype != IPV6_DSTOPTS && opt->dst1opt)
778 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst1opt));
779 }
780
781 if (newopt && newoptlen)
782 tot_len += CMSG_ALIGN(newoptlen);
783
784 if (!tot_len)
785 return NULL;
786
787 tot_len += sizeof(*opt2);
788 opt2 = sock_kmalloc(sk, tot_len, GFP_ATOMIC);
789 if (!opt2)
790 return ERR_PTR(-ENOBUFS);
791
792 memset(opt2, 0, tot_len);
793
794 opt2->tot_len = tot_len;
795 p = (char *)(opt2 + 1);
796
797 err = ipv6_renew_option(opt ? opt->hopopt : NULL, newopt, newoptlen,
798 newtype != IPV6_HOPOPTS,
799 &opt2->hopopt, &p);
800 if (err)
801 goto out;
802
803 err = ipv6_renew_option(opt ? opt->dst0opt : NULL, newopt, newoptlen,
804 newtype != IPV6_RTHDRDSTOPTS,
805 &opt2->dst0opt, &p);
806 if (err)
807 goto out;
808
809 err = ipv6_renew_option(opt ? opt->srcrt : NULL, newopt, newoptlen,
810 newtype != IPV6_RTHDR,
811 (struct ipv6_opt_hdr **)&opt2->srcrt, &p);
812 if (err)
813 goto out;
814
815 err = ipv6_renew_option(opt ? opt->dst1opt : NULL, newopt, newoptlen,
816 newtype != IPV6_DSTOPTS,
817 &opt2->dst1opt, &p);
818 if (err)
819 goto out;
820
821 opt2->opt_nflen = (opt2->hopopt ? ipv6_optlen(opt2->hopopt) : 0) +
822 (opt2->dst0opt ? ipv6_optlen(opt2->dst0opt) : 0) +
823 (opt2->srcrt ? ipv6_optlen(opt2->srcrt) : 0);
824 opt2->opt_flen = (opt2->dst1opt ? ipv6_optlen(opt2->dst1opt) : 0);
825
826 return opt2;
827out:
828 sock_kfree_s(sk, opt2, opt2->tot_len);
829 return ERR_PTR(err);
830}
831
832struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space,
833 struct ipv6_txoptions *opt)
834{
835 /*
836 * ignore the dest before srcrt unless srcrt is being included.
837 * --yoshfuji
838 */
839 if (opt && opt->dst0opt && !opt->srcrt) {
840 if (opt_space != opt) {
841 memcpy(opt_space, opt, sizeof(*opt_space));
842 opt = opt_space;
843 }
844 opt->opt_nflen -= ipv6_optlen(opt->dst0opt);
845 opt->dst0opt = NULL;
846 }
847
848 return opt;
849}
850EXPORT_SYMBOL_GPL(ipv6_fixup_options);
851
852/**
853 * fl6_update_dst - update flowi destination address with info given
854 * by srcrt option, if any.
855 *
856 * @fl6: flowi6 for which daddr is to be updated
857 * @opt: struct ipv6_txoptions in which to look for srcrt opt
858 * @orig: copy of original daddr address if modified
859 *
860 * Returns NULL if no txoptions or no srcrt, otherwise returns orig
861 * and initial value of fl6->daddr set in orig
862 */
863struct in6_addr *fl6_update_dst(struct flowi6 *fl6,
864 const struct ipv6_txoptions *opt,
865 struct in6_addr *orig)
866{
867 if (!opt || !opt->srcrt)
868 return NULL;
869
870 *orig = fl6->daddr;
871 fl6->daddr = *((struct rt0_hdr *)opt->srcrt)->addr;
872 return orig;
873}
874EXPORT_SYMBOL_GPL(fl6_update_dst);
Linux kernel - Deliverables
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