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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 IS_ENABLED(CONFIG_IPV6_MIP6)
47#include <net/xfrm.h>
48#endif
49
50#include <linux/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 net_dbg_ratelimited("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 net_dbg_ratelimited("hao invalid option length = %d\n",
197 hao->length);
198 goto discard;
199 }
200
201 if (!(ipv6_addr_type(&hao->addr) & IPV6_ADDR_UNICAST)) {
202 net_dbg_ratelimited("hao is not an unicast addr: %pI6\n",
203 &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 net_dbg_ratelimited("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 net_dbg_ratelimited("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->flags |= IP6SKB_HOPBYHOP;
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 atomic_set(&opt2->refcnt, 1);
731 }
732 return opt2;
733}
734EXPORT_SYMBOL_GPL(ipv6_dup_options);
735
736static int ipv6_renew_option(void *ohdr,
737 struct ipv6_opt_hdr __user *newopt, int newoptlen,
738 int inherit,
739 struct ipv6_opt_hdr **hdr,
740 char **p)
741{
742 if (inherit) {
743 if (ohdr) {
744 memcpy(*p, ohdr, ipv6_optlen((struct ipv6_opt_hdr *)ohdr));
745 *hdr = (struct ipv6_opt_hdr *)*p;
746 *p += CMSG_ALIGN(ipv6_optlen(*hdr));
747 }
748 } else {
749 if (newopt) {
750 if (copy_from_user(*p, newopt, newoptlen))
751 return -EFAULT;
752 *hdr = (struct ipv6_opt_hdr *)*p;
753 if (ipv6_optlen(*hdr) > newoptlen)
754 return -EINVAL;
755 *p += CMSG_ALIGN(newoptlen);
756 }
757 }
758 return 0;
759}
760
761struct ipv6_txoptions *
762ipv6_renew_options(struct sock *sk, struct ipv6_txoptions *opt,
763 int newtype,
764 struct ipv6_opt_hdr __user *newopt, int newoptlen)
765{
766 int tot_len = 0;
767 char *p;
768 struct ipv6_txoptions *opt2;
769 int err;
770
771 if (opt) {
772 if (newtype != IPV6_HOPOPTS && opt->hopopt)
773 tot_len += CMSG_ALIGN(ipv6_optlen(opt->hopopt));
774 if (newtype != IPV6_RTHDRDSTOPTS && opt->dst0opt)
775 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst0opt));
776 if (newtype != IPV6_RTHDR && opt->srcrt)
777 tot_len += CMSG_ALIGN(ipv6_optlen(opt->srcrt));
778 if (newtype != IPV6_DSTOPTS && opt->dst1opt)
779 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst1opt));
780 }
781
782 if (newopt && newoptlen)
783 tot_len += CMSG_ALIGN(newoptlen);
784
785 if (!tot_len)
786 return NULL;
787
788 tot_len += sizeof(*opt2);
789 opt2 = sock_kmalloc(sk, tot_len, GFP_ATOMIC);
790 if (!opt2)
791 return ERR_PTR(-ENOBUFS);
792
793 memset(opt2, 0, tot_len);
794 atomic_set(&opt2->refcnt, 1);
795 opt2->tot_len = tot_len;
796 p = (char *)(opt2 + 1);
797
798 err = ipv6_renew_option(opt ? opt->hopopt : NULL, newopt, newoptlen,
799 newtype != IPV6_HOPOPTS,
800 &opt2->hopopt, &p);
801 if (err)
802 goto out;
803
804 err = ipv6_renew_option(opt ? opt->dst0opt : NULL, newopt, newoptlen,
805 newtype != IPV6_RTHDRDSTOPTS,
806 &opt2->dst0opt, &p);
807 if (err)
808 goto out;
809
810 err = ipv6_renew_option(opt ? opt->srcrt : NULL, newopt, newoptlen,
811 newtype != IPV6_RTHDR,
812 (struct ipv6_opt_hdr **)&opt2->srcrt, &p);
813 if (err)
814 goto out;
815
816 err = ipv6_renew_option(opt ? opt->dst1opt : NULL, newopt, newoptlen,
817 newtype != IPV6_DSTOPTS,
818 &opt2->dst1opt, &p);
819 if (err)
820 goto out;
821
822 opt2->opt_nflen = (opt2->hopopt ? ipv6_optlen(opt2->hopopt) : 0) +
823 (opt2->dst0opt ? ipv6_optlen(opt2->dst0opt) : 0) +
824 (opt2->srcrt ? ipv6_optlen(opt2->srcrt) : 0);
825 opt2->opt_flen = (opt2->dst1opt ? ipv6_optlen(opt2->dst1opt) : 0);
826
827 return opt2;
828out:
829 sock_kfree_s(sk, opt2, opt2->tot_len);
830 return ERR_PTR(err);
831}
832
833struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space,
834 struct ipv6_txoptions *opt)
835{
836 /*
837 * ignore the dest before srcrt unless srcrt is being included.
838 * --yoshfuji
839 */
840 if (opt && opt->dst0opt && !opt->srcrt) {
841 if (opt_space != opt) {
842 memcpy(opt_space, opt, sizeof(*opt_space));
843 opt = opt_space;
844 }
845 opt->opt_nflen -= ipv6_optlen(opt->dst0opt);
846 opt->dst0opt = NULL;
847 }
848
849 return opt;
850}
851EXPORT_SYMBOL_GPL(ipv6_fixup_options);
852
853/**
854 * fl6_update_dst - update flowi destination address with info given
855 * by srcrt option, if any.
856 *
857 * @fl6: flowi6 for which daddr is to be updated
858 * @opt: struct ipv6_txoptions in which to look for srcrt opt
859 * @orig: copy of original daddr address if modified
860 *
861 * Returns NULL if no txoptions or no srcrt, otherwise returns orig
862 * and initial value of fl6->daddr set in orig
863 */
864struct in6_addr *fl6_update_dst(struct flowi6 *fl6,
865 const struct ipv6_txoptions *opt,
866 struct in6_addr *orig)
867{
868 if (!opt || !opt->srcrt)
869 return NULL;
870
871 *orig = fl6->daddr;
872 fl6->daddr = *((struct rt0_hdr *)opt->srcrt)->addr;
873 return orig;
874}
875EXPORT_SYMBOL_GPL(fl6_update_dst);
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Extension Header handling for IPv6
4 * Linux INET6 implementation
5 *
6 * Authors:
7 * Pedro Roque <roque@di.fc.ul.pt>
8 * Andi Kleen <ak@muc.de>
9 * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
10 */
11
12/* Changes:
13 * yoshfuji : ensure not to overrun while parsing
14 * tlv options.
15 * Mitsuru KANDA @USAGI and: Remove ipv6_parse_exthdrs().
16 * YOSHIFUJI Hideaki @USAGI Register inbound extension header
17 * handlers as inet6_protocol{}.
18 */
19
20#include <linux/errno.h>
21#include <linux/types.h>
22#include <linux/socket.h>
23#include <linux/sockios.h>
24#include <linux/net.h>
25#include <linux/netdevice.h>
26#include <linux/in6.h>
27#include <linux/icmpv6.h>
28#include <linux/slab.h>
29#include <linux/export.h>
30
31#include <net/dst.h>
32#include <net/sock.h>
33#include <net/snmp.h>
34
35#include <net/ipv6.h>
36#include <net/protocol.h>
37#include <net/transp_v6.h>
38#include <net/rawv6.h>
39#include <net/ndisc.h>
40#include <net/ip6_route.h>
41#include <net/addrconf.h>
42#include <net/calipso.h>
43#if IS_ENABLED(CONFIG_IPV6_MIP6)
44#include <net/xfrm.h>
45#endif
46#include <linux/seg6.h>
47#include <net/seg6.h>
48#ifdef CONFIG_IPV6_SEG6_HMAC
49#include <net/seg6_hmac.h>
50#endif
51#include <net/rpl.h>
52#include <linux/ioam6.h>
53#include <net/ioam6.h>
54#include <net/dst_metadata.h>
55
56#include <linux/uaccess.h>
57
58/*********************
59 Generic functions
60 *********************/
61
62/* An unknown option is detected, decide what to do */
63
64static bool ip6_tlvopt_unknown(struct sk_buff *skb, int optoff,
65 bool disallow_unknowns)
66{
67 if (disallow_unknowns) {
68 /* If unknown TLVs are disallowed by configuration
69 * then always silently drop packet. Note this also
70 * means no ICMP parameter problem is sent which
71 * could be a good property to mitigate a reflection DOS
72 * attack.
73 */
74
75 goto drop;
76 }
77
78 switch ((skb_network_header(skb)[optoff] & 0xC0) >> 6) {
79 case 0: /* ignore */
80 return true;
81
82 case 1: /* drop packet */
83 break;
84
85 case 3: /* Send ICMP if not a multicast address and drop packet */
86 /* Actually, it is redundant check. icmp_send
87 will recheck in any case.
88 */
89 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr))
90 break;
91 fallthrough;
92 case 2: /* send ICMP PARM PROB regardless and drop packet */
93 icmpv6_param_prob_reason(skb, ICMPV6_UNK_OPTION, optoff,
94 SKB_DROP_REASON_UNHANDLED_PROTO);
95 return false;
96 }
97
98drop:
99 kfree_skb_reason(skb, SKB_DROP_REASON_UNHANDLED_PROTO);
100 return false;
101}
102
103static bool ipv6_hop_ra(struct sk_buff *skb, int optoff);
104static bool ipv6_hop_ioam(struct sk_buff *skb, int optoff);
105static bool ipv6_hop_jumbo(struct sk_buff *skb, int optoff);
106static bool ipv6_hop_calipso(struct sk_buff *skb, int optoff);
107#if IS_ENABLED(CONFIG_IPV6_MIP6)
108static bool ipv6_dest_hao(struct sk_buff *skb, int optoff);
109#endif
110
111/* Parse tlv encoded option header (hop-by-hop or destination) */
112
113static bool ip6_parse_tlv(bool hopbyhop,
114 struct sk_buff *skb,
115 int max_count)
116{
117 int len = (skb_transport_header(skb)[1] + 1) << 3;
118 const unsigned char *nh = skb_network_header(skb);
119 int off = skb_network_header_len(skb);
120 bool disallow_unknowns = false;
121 int tlv_count = 0;
122 int padlen = 0;
123
124 if (unlikely(max_count < 0)) {
125 disallow_unknowns = true;
126 max_count = -max_count;
127 }
128
129 if (skb_transport_offset(skb) + len > skb_headlen(skb))
130 goto bad;
131
132 off += 2;
133 len -= 2;
134
135 while (len > 0) {
136 int optlen, i;
137
138 if (nh[off] == IPV6_TLV_PAD1) {
139 padlen++;
140 if (padlen > 7)
141 goto bad;
142 off++;
143 len--;
144 continue;
145 }
146 if (len < 2)
147 goto bad;
148 optlen = nh[off + 1] + 2;
149 if (optlen > len)
150 goto bad;
151
152 if (nh[off] == IPV6_TLV_PADN) {
153 /* RFC 2460 states that the purpose of PadN is
154 * to align the containing header to multiples
155 * of 8. 7 is therefore the highest valid value.
156 * See also RFC 4942, Section 2.1.9.5.
157 */
158 padlen += optlen;
159 if (padlen > 7)
160 goto bad;
161 /* RFC 4942 recommends receiving hosts to
162 * actively check PadN payload to contain
163 * only zeroes.
164 */
165 for (i = 2; i < optlen; i++) {
166 if (nh[off + i] != 0)
167 goto bad;
168 }
169 } else {
170 tlv_count++;
171 if (tlv_count > max_count)
172 goto bad;
173
174 if (hopbyhop) {
175 switch (nh[off]) {
176 case IPV6_TLV_ROUTERALERT:
177 if (!ipv6_hop_ra(skb, off))
178 return false;
179 break;
180 case IPV6_TLV_IOAM:
181 if (!ipv6_hop_ioam(skb, off))
182 return false;
183 break;
184 case IPV6_TLV_JUMBO:
185 if (!ipv6_hop_jumbo(skb, off))
186 return false;
187 break;
188 case IPV6_TLV_CALIPSO:
189 if (!ipv6_hop_calipso(skb, off))
190 return false;
191 break;
192 default:
193 if (!ip6_tlvopt_unknown(skb, off,
194 disallow_unknowns))
195 return false;
196 break;
197 }
198 } else {
199 switch (nh[off]) {
200#if IS_ENABLED(CONFIG_IPV6_MIP6)
201 case IPV6_TLV_HAO:
202 if (!ipv6_dest_hao(skb, off))
203 return false;
204 break;
205#endif
206 default:
207 if (!ip6_tlvopt_unknown(skb, off,
208 disallow_unknowns))
209 return false;
210 break;
211 }
212 }
213 padlen = 0;
214 }
215 off += optlen;
216 len -= optlen;
217 }
218
219 if (len == 0)
220 return true;
221bad:
222 kfree_skb_reason(skb, SKB_DROP_REASON_IP_INHDR);
223 return false;
224}
225
226/*****************************
227 Destination options header.
228 *****************************/
229
230#if IS_ENABLED(CONFIG_IPV6_MIP6)
231static bool ipv6_dest_hao(struct sk_buff *skb, int optoff)
232{
233 struct ipv6_destopt_hao *hao;
234 struct inet6_skb_parm *opt = IP6CB(skb);
235 struct ipv6hdr *ipv6h = ipv6_hdr(skb);
236 SKB_DR(reason);
237 int ret;
238
239 if (opt->dsthao) {
240 net_dbg_ratelimited("hao duplicated\n");
241 goto discard;
242 }
243 opt->dsthao = opt->dst1;
244 opt->dst1 = 0;
245
246 hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) + optoff);
247
248 if (hao->length != 16) {
249 net_dbg_ratelimited("hao invalid option length = %d\n",
250 hao->length);
251 SKB_DR_SET(reason, IP_INHDR);
252 goto discard;
253 }
254
255 if (!(ipv6_addr_type(&hao->addr) & IPV6_ADDR_UNICAST)) {
256 net_dbg_ratelimited("hao is not an unicast addr: %pI6\n",
257 &hao->addr);
258 SKB_DR_SET(reason, INVALID_PROTO);
259 goto discard;
260 }
261
262 ret = xfrm6_input_addr(skb, (xfrm_address_t *)&ipv6h->daddr,
263 (xfrm_address_t *)&hao->addr, IPPROTO_DSTOPTS);
264 if (unlikely(ret < 0)) {
265 SKB_DR_SET(reason, XFRM_POLICY);
266 goto discard;
267 }
268
269 if (skb_cloned(skb)) {
270 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
271 goto discard;
272
273 /* update all variable using below by copied skbuff */
274 hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) +
275 optoff);
276 ipv6h = ipv6_hdr(skb);
277 }
278
279 if (skb->ip_summed == CHECKSUM_COMPLETE)
280 skb->ip_summed = CHECKSUM_NONE;
281
282 swap(ipv6h->saddr, hao->addr);
283
284 if (skb->tstamp == 0)
285 __net_timestamp(skb);
286
287 return true;
288
289 discard:
290 kfree_skb_reason(skb, reason);
291 return false;
292}
293#endif
294
295static int ipv6_destopt_rcv(struct sk_buff *skb)
296{
297 struct inet6_dev *idev = __in6_dev_get(skb->dev);
298 struct inet6_skb_parm *opt = IP6CB(skb);
299#if IS_ENABLED(CONFIG_IPV6_MIP6)
300 __u16 dstbuf;
301#endif
302 struct dst_entry *dst = skb_dst(skb);
303 struct net *net = dev_net(skb->dev);
304 int extlen;
305
306 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
307 !pskb_may_pull(skb, (skb_transport_offset(skb) +
308 ((skb_transport_header(skb)[1] + 1) << 3)))) {
309 __IP6_INC_STATS(dev_net(dst->dev), idev,
310 IPSTATS_MIB_INHDRERRORS);
311fail_and_free:
312 kfree_skb(skb);
313 return -1;
314 }
315
316 extlen = (skb_transport_header(skb)[1] + 1) << 3;
317 if (extlen > net->ipv6.sysctl.max_dst_opts_len)
318 goto fail_and_free;
319
320 opt->lastopt = opt->dst1 = skb_network_header_len(skb);
321#if IS_ENABLED(CONFIG_IPV6_MIP6)
322 dstbuf = opt->dst1;
323#endif
324
325 if (ip6_parse_tlv(false, skb, net->ipv6.sysctl.max_dst_opts_cnt)) {
326 skb->transport_header += extlen;
327 opt = IP6CB(skb);
328#if IS_ENABLED(CONFIG_IPV6_MIP6)
329 opt->nhoff = dstbuf;
330#else
331 opt->nhoff = opt->dst1;
332#endif
333 return 1;
334 }
335
336 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
337 return -1;
338}
339
340static void seg6_update_csum(struct sk_buff *skb)
341{
342 struct ipv6_sr_hdr *hdr;
343 struct in6_addr *addr;
344 __be32 from, to;
345
346 /* srh is at transport offset and seg_left is already decremented
347 * but daddr is not yet updated with next segment
348 */
349
350 hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb);
351 addr = hdr->segments + hdr->segments_left;
352
353 hdr->segments_left++;
354 from = *(__be32 *)hdr;
355
356 hdr->segments_left--;
357 to = *(__be32 *)hdr;
358
359 /* update skb csum with diff resulting from seg_left decrement */
360
361 update_csum_diff4(skb, from, to);
362
363 /* compute csum diff between current and next segment and update */
364
365 update_csum_diff16(skb, (__be32 *)(&ipv6_hdr(skb)->daddr),
366 (__be32 *)addr);
367}
368
369static int ipv6_srh_rcv(struct sk_buff *skb)
370{
371 struct inet6_skb_parm *opt = IP6CB(skb);
372 struct net *net = dev_net(skb->dev);
373 struct ipv6_sr_hdr *hdr;
374 struct inet6_dev *idev;
375 struct in6_addr *addr;
376 int accept_seg6;
377
378 hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb);
379
380 idev = __in6_dev_get(skb->dev);
381
382 accept_seg6 = net->ipv6.devconf_all->seg6_enabled;
383 if (accept_seg6 > idev->cnf.seg6_enabled)
384 accept_seg6 = idev->cnf.seg6_enabled;
385
386 if (!accept_seg6) {
387 kfree_skb(skb);
388 return -1;
389 }
390
391#ifdef CONFIG_IPV6_SEG6_HMAC
392 if (!seg6_hmac_validate_skb(skb)) {
393 kfree_skb(skb);
394 return -1;
395 }
396#endif
397
398looped_back:
399 if (hdr->segments_left == 0) {
400 if (hdr->nexthdr == NEXTHDR_IPV6 || hdr->nexthdr == NEXTHDR_IPV4) {
401 int offset = (hdr->hdrlen + 1) << 3;
402
403 skb_postpull_rcsum(skb, skb_network_header(skb),
404 skb_network_header_len(skb));
405
406 if (!pskb_pull(skb, offset)) {
407 kfree_skb(skb);
408 return -1;
409 }
410 skb_postpull_rcsum(skb, skb_transport_header(skb),
411 offset);
412
413 skb_reset_network_header(skb);
414 skb_reset_transport_header(skb);
415 skb->encapsulation = 0;
416 if (hdr->nexthdr == NEXTHDR_IPV4)
417 skb->protocol = htons(ETH_P_IP);
418 __skb_tunnel_rx(skb, skb->dev, net);
419
420 netif_rx(skb);
421 return -1;
422 }
423
424 opt->srcrt = skb_network_header_len(skb);
425 opt->lastopt = opt->srcrt;
426 skb->transport_header += (hdr->hdrlen + 1) << 3;
427 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb);
428
429 return 1;
430 }
431
432 if (hdr->segments_left >= (hdr->hdrlen >> 1)) {
433 __IP6_INC_STATS(net, idev, 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 if (skb_cloned(skb)) {
441 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) {
442 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
443 IPSTATS_MIB_OUTDISCARDS);
444 kfree_skb(skb);
445 return -1;
446 }
447 }
448
449 hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb);
450
451 hdr->segments_left--;
452 addr = hdr->segments + hdr->segments_left;
453
454 skb_push(skb, sizeof(struct ipv6hdr));
455
456 if (skb->ip_summed == CHECKSUM_COMPLETE)
457 seg6_update_csum(skb);
458
459 ipv6_hdr(skb)->daddr = *addr;
460
461 skb_dst_drop(skb);
462
463 ip6_route_input(skb);
464
465 if (skb_dst(skb)->error) {
466 dst_input(skb);
467 return -1;
468 }
469
470 if (skb_dst(skb)->dev->flags & IFF_LOOPBACK) {
471 if (ipv6_hdr(skb)->hop_limit <= 1) {
472 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
473 icmpv6_send(skb, ICMPV6_TIME_EXCEED,
474 ICMPV6_EXC_HOPLIMIT, 0);
475 kfree_skb(skb);
476 return -1;
477 }
478 ipv6_hdr(skb)->hop_limit--;
479
480 skb_pull(skb, sizeof(struct ipv6hdr));
481 goto looped_back;
482 }
483
484 dst_input(skb);
485
486 return -1;
487}
488
489static int ipv6_rpl_srh_rcv(struct sk_buff *skb)
490{
491 struct ipv6_rpl_sr_hdr *hdr, *ohdr, *chdr;
492 struct inet6_skb_parm *opt = IP6CB(skb);
493 struct net *net = dev_net(skb->dev);
494 struct inet6_dev *idev;
495 struct ipv6hdr *oldhdr;
496 unsigned char *buf;
497 int accept_rpl_seg;
498 int i, err;
499 u64 n = 0;
500 u32 r;
501
502 idev = __in6_dev_get(skb->dev);
503
504 accept_rpl_seg = net->ipv6.devconf_all->rpl_seg_enabled;
505 if (accept_rpl_seg > idev->cnf.rpl_seg_enabled)
506 accept_rpl_seg = idev->cnf.rpl_seg_enabled;
507
508 if (!accept_rpl_seg) {
509 kfree_skb(skb);
510 return -1;
511 }
512
513looped_back:
514 hdr = (struct ipv6_rpl_sr_hdr *)skb_transport_header(skb);
515
516 if (hdr->segments_left == 0) {
517 if (hdr->nexthdr == NEXTHDR_IPV6) {
518 int offset = (hdr->hdrlen + 1) << 3;
519
520 skb_postpull_rcsum(skb, skb_network_header(skb),
521 skb_network_header_len(skb));
522
523 if (!pskb_pull(skb, offset)) {
524 kfree_skb(skb);
525 return -1;
526 }
527 skb_postpull_rcsum(skb, skb_transport_header(skb),
528 offset);
529
530 skb_reset_network_header(skb);
531 skb_reset_transport_header(skb);
532 skb->encapsulation = 0;
533
534 __skb_tunnel_rx(skb, skb->dev, net);
535
536 netif_rx(skb);
537 return -1;
538 }
539
540 opt->srcrt = skb_network_header_len(skb);
541 opt->lastopt = opt->srcrt;
542 skb->transport_header += (hdr->hdrlen + 1) << 3;
543 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb);
544
545 return 1;
546 }
547
548 if (!pskb_may_pull(skb, sizeof(*hdr))) {
549 kfree_skb(skb);
550 return -1;
551 }
552
553 n = (hdr->hdrlen << 3) - hdr->pad - (16 - hdr->cmpre);
554 r = do_div(n, (16 - hdr->cmpri));
555 /* checks if calculation was without remainder and n fits into
556 * unsigned char which is segments_left field. Should not be
557 * higher than that.
558 */
559 if (r || (n + 1) > 255) {
560 kfree_skb(skb);
561 return -1;
562 }
563
564 if (hdr->segments_left > n + 1) {
565 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
566 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
567 ((&hdr->segments_left) -
568 skb_network_header(skb)));
569 return -1;
570 }
571
572 if (skb_cloned(skb)) {
573 if (pskb_expand_head(skb, IPV6_RPL_SRH_WORST_SWAP_SIZE, 0,
574 GFP_ATOMIC)) {
575 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
576 IPSTATS_MIB_OUTDISCARDS);
577 kfree_skb(skb);
578 return -1;
579 }
580 } else {
581 err = skb_cow_head(skb, IPV6_RPL_SRH_WORST_SWAP_SIZE);
582 if (unlikely(err)) {
583 kfree_skb(skb);
584 return -1;
585 }
586 }
587
588 hdr = (struct ipv6_rpl_sr_hdr *)skb_transport_header(skb);
589
590 if (!pskb_may_pull(skb, ipv6_rpl_srh_size(n, hdr->cmpri,
591 hdr->cmpre))) {
592 kfree_skb(skb);
593 return -1;
594 }
595
596 hdr->segments_left--;
597 i = n - hdr->segments_left;
598
599 buf = kcalloc(struct_size(hdr, segments.addr, n + 2), 2, GFP_ATOMIC);
600 if (unlikely(!buf)) {
601 kfree_skb(skb);
602 return -1;
603 }
604
605 ohdr = (struct ipv6_rpl_sr_hdr *)buf;
606 ipv6_rpl_srh_decompress(ohdr, hdr, &ipv6_hdr(skb)->daddr, n);
607 chdr = (struct ipv6_rpl_sr_hdr *)(buf + ((ohdr->hdrlen + 1) << 3));
608
609 if ((ipv6_addr_type(&ipv6_hdr(skb)->daddr) & IPV6_ADDR_MULTICAST) ||
610 (ipv6_addr_type(&ohdr->rpl_segaddr[i]) & IPV6_ADDR_MULTICAST)) {
611 kfree_skb(skb);
612 kfree(buf);
613 return -1;
614 }
615
616 err = ipv6_chk_rpl_srh_loop(net, ohdr->rpl_segaddr, n + 1);
617 if (err) {
618 icmpv6_send(skb, ICMPV6_PARAMPROB, 0, 0);
619 kfree_skb(skb);
620 kfree(buf);
621 return -1;
622 }
623
624 swap(ipv6_hdr(skb)->daddr, ohdr->rpl_segaddr[i]);
625
626 ipv6_rpl_srh_compress(chdr, ohdr, &ipv6_hdr(skb)->daddr, n);
627
628 oldhdr = ipv6_hdr(skb);
629
630 skb_pull(skb, ((hdr->hdrlen + 1) << 3));
631 skb_postpull_rcsum(skb, oldhdr,
632 sizeof(struct ipv6hdr) + ((hdr->hdrlen + 1) << 3));
633 skb_push(skb, ((chdr->hdrlen + 1) << 3) + sizeof(struct ipv6hdr));
634 skb_reset_network_header(skb);
635 skb_mac_header_rebuild(skb);
636 skb_set_transport_header(skb, sizeof(struct ipv6hdr));
637
638 memmove(ipv6_hdr(skb), oldhdr, sizeof(struct ipv6hdr));
639 memcpy(skb_transport_header(skb), chdr, (chdr->hdrlen + 1) << 3);
640
641 ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
642 skb_postpush_rcsum(skb, ipv6_hdr(skb),
643 sizeof(struct ipv6hdr) + ((chdr->hdrlen + 1) << 3));
644
645 kfree(buf);
646
647 skb_dst_drop(skb);
648
649 ip6_route_input(skb);
650
651 if (skb_dst(skb)->error) {
652 dst_input(skb);
653 return -1;
654 }
655
656 if (skb_dst(skb)->dev->flags & IFF_LOOPBACK) {
657 if (ipv6_hdr(skb)->hop_limit <= 1) {
658 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
659 icmpv6_send(skb, ICMPV6_TIME_EXCEED,
660 ICMPV6_EXC_HOPLIMIT, 0);
661 kfree_skb(skb);
662 return -1;
663 }
664 ipv6_hdr(skb)->hop_limit--;
665
666 skb_pull(skb, sizeof(struct ipv6hdr));
667 goto looped_back;
668 }
669
670 dst_input(skb);
671
672 return -1;
673}
674
675/********************************
676 Routing header.
677 ********************************/
678
679/* called with rcu_read_lock() */
680static int ipv6_rthdr_rcv(struct sk_buff *skb)
681{
682 struct inet6_dev *idev = __in6_dev_get(skb->dev);
683 struct inet6_skb_parm *opt = IP6CB(skb);
684 struct in6_addr *addr = NULL;
685 struct in6_addr daddr;
686 int n, i;
687 struct ipv6_rt_hdr *hdr;
688 struct rt0_hdr *rthdr;
689 struct net *net = dev_net(skb->dev);
690 int accept_source_route = net->ipv6.devconf_all->accept_source_route;
691
692 if (idev && accept_source_route > idev->cnf.accept_source_route)
693 accept_source_route = idev->cnf.accept_source_route;
694
695 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
696 !pskb_may_pull(skb, (skb_transport_offset(skb) +
697 ((skb_transport_header(skb)[1] + 1) << 3)))) {
698 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
699 kfree_skb(skb);
700 return -1;
701 }
702
703 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb);
704
705 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) ||
706 skb->pkt_type != PACKET_HOST) {
707 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
708 kfree_skb(skb);
709 return -1;
710 }
711
712 switch (hdr->type) {
713 case IPV6_SRCRT_TYPE_4:
714 /* segment routing */
715 return ipv6_srh_rcv(skb);
716 case IPV6_SRCRT_TYPE_3:
717 /* rpl segment routing */
718 return ipv6_rpl_srh_rcv(skb);
719 default:
720 break;
721 }
722
723looped_back:
724 if (hdr->segments_left == 0) {
725 switch (hdr->type) {
726#if IS_ENABLED(CONFIG_IPV6_MIP6)
727 case IPV6_SRCRT_TYPE_2:
728 /* Silently discard type 2 header unless it was
729 * processed by own
730 */
731 if (!addr) {
732 __IP6_INC_STATS(net, idev,
733 IPSTATS_MIB_INADDRERRORS);
734 kfree_skb(skb);
735 return -1;
736 }
737 break;
738#endif
739 default:
740 break;
741 }
742
743 opt->lastopt = opt->srcrt = skb_network_header_len(skb);
744 skb->transport_header += (hdr->hdrlen + 1) << 3;
745 opt->dst0 = opt->dst1;
746 opt->dst1 = 0;
747 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb);
748 return 1;
749 }
750
751 switch (hdr->type) {
752#if IS_ENABLED(CONFIG_IPV6_MIP6)
753 case IPV6_SRCRT_TYPE_2:
754 if (accept_source_route < 0)
755 goto unknown_rh;
756 /* Silently discard invalid RTH type 2 */
757 if (hdr->hdrlen != 2 || hdr->segments_left != 1) {
758 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
759 kfree_skb(skb);
760 return -1;
761 }
762 break;
763#endif
764 default:
765 goto unknown_rh;
766 }
767
768 /*
769 * This is the routing header forwarding algorithm from
770 * RFC 2460, page 16.
771 */
772
773 n = hdr->hdrlen >> 1;
774
775 if (hdr->segments_left > n) {
776 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
777 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
778 ((&hdr->segments_left) -
779 skb_network_header(skb)));
780 return -1;
781 }
782
783 /* We are about to mangle packet header. Be careful!
784 Do not damage packets queued somewhere.
785 */
786 if (skb_cloned(skb)) {
787 /* the copy is a forwarded packet */
788 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) {
789 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
790 IPSTATS_MIB_OUTDISCARDS);
791 kfree_skb(skb);
792 return -1;
793 }
794 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb);
795 }
796
797 if (skb->ip_summed == CHECKSUM_COMPLETE)
798 skb->ip_summed = CHECKSUM_NONE;
799
800 i = n - --hdr->segments_left;
801
802 rthdr = (struct rt0_hdr *) hdr;
803 addr = rthdr->addr;
804 addr += i - 1;
805
806 switch (hdr->type) {
807#if IS_ENABLED(CONFIG_IPV6_MIP6)
808 case IPV6_SRCRT_TYPE_2:
809 if (xfrm6_input_addr(skb, (xfrm_address_t *)addr,
810 (xfrm_address_t *)&ipv6_hdr(skb)->saddr,
811 IPPROTO_ROUTING) < 0) {
812 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
813 kfree_skb(skb);
814 return -1;
815 }
816 if (!ipv6_chk_home_addr(dev_net(skb_dst(skb)->dev), addr)) {
817 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
818 kfree_skb(skb);
819 return -1;
820 }
821 break;
822#endif
823 default:
824 break;
825 }
826
827 if (ipv6_addr_is_multicast(addr)) {
828 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
829 kfree_skb(skb);
830 return -1;
831 }
832
833 daddr = *addr;
834 *addr = ipv6_hdr(skb)->daddr;
835 ipv6_hdr(skb)->daddr = daddr;
836
837 skb_dst_drop(skb);
838 ip6_route_input(skb);
839 if (skb_dst(skb)->error) {
840 skb_push(skb, skb->data - skb_network_header(skb));
841 dst_input(skb);
842 return -1;
843 }
844
845 if (skb_dst(skb)->dev->flags&IFF_LOOPBACK) {
846 if (ipv6_hdr(skb)->hop_limit <= 1) {
847 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
848 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
849 0);
850 kfree_skb(skb);
851 return -1;
852 }
853 ipv6_hdr(skb)->hop_limit--;
854 goto looped_back;
855 }
856
857 skb_push(skb, skb->data - skb_network_header(skb));
858 dst_input(skb);
859 return -1;
860
861unknown_rh:
862 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
863 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
864 (&hdr->type) - skb_network_header(skb));
865 return -1;
866}
867
868static const struct inet6_protocol rthdr_protocol = {
869 .handler = ipv6_rthdr_rcv,
870 .flags = INET6_PROTO_NOPOLICY,
871};
872
873static const struct inet6_protocol destopt_protocol = {
874 .handler = ipv6_destopt_rcv,
875 .flags = INET6_PROTO_NOPOLICY,
876};
877
878static const struct inet6_protocol nodata_protocol = {
879 .handler = dst_discard,
880 .flags = INET6_PROTO_NOPOLICY,
881};
882
883int __init ipv6_exthdrs_init(void)
884{
885 int ret;
886
887 ret = inet6_add_protocol(&rthdr_protocol, IPPROTO_ROUTING);
888 if (ret)
889 goto out;
890
891 ret = inet6_add_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
892 if (ret)
893 goto out_rthdr;
894
895 ret = inet6_add_protocol(&nodata_protocol, IPPROTO_NONE);
896 if (ret)
897 goto out_destopt;
898
899out:
900 return ret;
901out_destopt:
902 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
903out_rthdr:
904 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING);
905 goto out;
906};
907
908void ipv6_exthdrs_exit(void)
909{
910 inet6_del_protocol(&nodata_protocol, IPPROTO_NONE);
911 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
912 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING);
913}
914
915/**********************************
916 Hop-by-hop options.
917 **********************************/
918
919/*
920 * Note: we cannot rely on skb_dst(skb) before we assign it in ip6_route_input().
921 */
922static inline struct net *ipv6_skb_net(struct sk_buff *skb)
923{
924 return skb_dst(skb) ? dev_net(skb_dst(skb)->dev) : dev_net(skb->dev);
925}
926
927/* Router Alert as of RFC 2711 */
928
929static bool ipv6_hop_ra(struct sk_buff *skb, int optoff)
930{
931 const unsigned char *nh = skb_network_header(skb);
932
933 if (nh[optoff + 1] == 2) {
934 IP6CB(skb)->flags |= IP6SKB_ROUTERALERT;
935 memcpy(&IP6CB(skb)->ra, nh + optoff + 2, sizeof(IP6CB(skb)->ra));
936 return true;
937 }
938 net_dbg_ratelimited("ipv6_hop_ra: wrong RA length %d\n",
939 nh[optoff + 1]);
940 kfree_skb_reason(skb, SKB_DROP_REASON_IP_INHDR);
941 return false;
942}
943
944/* IOAM */
945
946static bool ipv6_hop_ioam(struct sk_buff *skb, int optoff)
947{
948 struct ioam6_trace_hdr *trace;
949 struct ioam6_namespace *ns;
950 struct ioam6_hdr *hdr;
951
952 /* Bad alignment (must be 4n-aligned) */
953 if (optoff & 3)
954 goto drop;
955
956 /* Ignore if IOAM is not enabled on ingress */
957 if (!__in6_dev_get(skb->dev)->cnf.ioam6_enabled)
958 goto ignore;
959
960 /* Truncated Option header */
961 hdr = (struct ioam6_hdr *)(skb_network_header(skb) + optoff);
962 if (hdr->opt_len < 2)
963 goto drop;
964
965 switch (hdr->type) {
966 case IOAM6_TYPE_PREALLOC:
967 /* Truncated Pre-allocated Trace header */
968 if (hdr->opt_len < 2 + sizeof(*trace))
969 goto drop;
970
971 /* Malformed Pre-allocated Trace header */
972 trace = (struct ioam6_trace_hdr *)((u8 *)hdr + sizeof(*hdr));
973 if (hdr->opt_len < 2 + sizeof(*trace) + trace->remlen * 4)
974 goto drop;
975
976 /* Ignore if the IOAM namespace is unknown */
977 ns = ioam6_namespace(ipv6_skb_net(skb), trace->namespace_id);
978 if (!ns)
979 goto ignore;
980
981 if (!skb_valid_dst(skb))
982 ip6_route_input(skb);
983
984 ioam6_fill_trace_data(skb, ns, trace, true);
985 break;
986 default:
987 break;
988 }
989
990ignore:
991 return true;
992
993drop:
994 kfree_skb_reason(skb, SKB_DROP_REASON_IP_INHDR);
995 return false;
996}
997
998/* Jumbo payload */
999
1000static bool ipv6_hop_jumbo(struct sk_buff *skb, int optoff)
1001{
1002 const unsigned char *nh = skb_network_header(skb);
1003 SKB_DR(reason);
1004 u32 pkt_len;
1005
1006 if (nh[optoff + 1] != 4 || (optoff & 3) != 2) {
1007 net_dbg_ratelimited("ipv6_hop_jumbo: wrong jumbo opt length/alignment %d\n",
1008 nh[optoff+1]);
1009 SKB_DR_SET(reason, IP_INHDR);
1010 goto drop;
1011 }
1012
1013 pkt_len = ntohl(*(__be32 *)(nh + optoff + 2));
1014 if (pkt_len <= IPV6_MAXPLEN) {
1015 icmpv6_param_prob_reason(skb, ICMPV6_HDR_FIELD, optoff + 2,
1016 SKB_DROP_REASON_IP_INHDR);
1017 return false;
1018 }
1019 if (ipv6_hdr(skb)->payload_len) {
1020 icmpv6_param_prob_reason(skb, ICMPV6_HDR_FIELD, optoff,
1021 SKB_DROP_REASON_IP_INHDR);
1022 return false;
1023 }
1024
1025 if (pkt_len > skb->len - sizeof(struct ipv6hdr)) {
1026 SKB_DR_SET(reason, PKT_TOO_SMALL);
1027 goto drop;
1028 }
1029
1030 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr)))
1031 goto drop;
1032
1033 IP6CB(skb)->flags |= IP6SKB_JUMBOGRAM;
1034 return true;
1035
1036drop:
1037 kfree_skb_reason(skb, reason);
1038 return false;
1039}
1040
1041/* CALIPSO RFC 5570 */
1042
1043static bool ipv6_hop_calipso(struct sk_buff *skb, int optoff)
1044{
1045 const unsigned char *nh = skb_network_header(skb);
1046
1047 if (nh[optoff + 1] < 8)
1048 goto drop;
1049
1050 if (nh[optoff + 6] * 4 + 8 > nh[optoff + 1])
1051 goto drop;
1052
1053 if (!calipso_validate(skb, nh + optoff))
1054 goto drop;
1055
1056 return true;
1057
1058drop:
1059 kfree_skb_reason(skb, SKB_DROP_REASON_IP_INHDR);
1060 return false;
1061}
1062
1063int ipv6_parse_hopopts(struct sk_buff *skb)
1064{
1065 struct inet6_skb_parm *opt = IP6CB(skb);
1066 struct net *net = dev_net(skb->dev);
1067 int extlen;
1068
1069 /*
1070 * skb_network_header(skb) is equal to skb->data, and
1071 * skb_network_header_len(skb) is always equal to
1072 * sizeof(struct ipv6hdr) by definition of
1073 * hop-by-hop options.
1074 */
1075 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + 8) ||
1076 !pskb_may_pull(skb, (sizeof(struct ipv6hdr) +
1077 ((skb_transport_header(skb)[1] + 1) << 3)))) {
1078fail_and_free:
1079 kfree_skb(skb);
1080 return -1;
1081 }
1082
1083 extlen = (skb_transport_header(skb)[1] + 1) << 3;
1084 if (extlen > net->ipv6.sysctl.max_hbh_opts_len)
1085 goto fail_and_free;
1086
1087 opt->flags |= IP6SKB_HOPBYHOP;
1088 if (ip6_parse_tlv(true, skb, net->ipv6.sysctl.max_hbh_opts_cnt)) {
1089 skb->transport_header += extlen;
1090 opt = IP6CB(skb);
1091 opt->nhoff = sizeof(struct ipv6hdr);
1092 return 1;
1093 }
1094 return -1;
1095}
1096
1097/*
1098 * Creating outbound headers.
1099 *
1100 * "build" functions work when skb is filled from head to tail (datagram)
1101 * "push" functions work when headers are added from tail to head (tcp)
1102 *
1103 * In both cases we assume, that caller reserved enough room
1104 * for headers.
1105 */
1106
1107static void ipv6_push_rthdr0(struct sk_buff *skb, u8 *proto,
1108 struct ipv6_rt_hdr *opt,
1109 struct in6_addr **addr_p, struct in6_addr *saddr)
1110{
1111 struct rt0_hdr *phdr, *ihdr;
1112 int hops;
1113
1114 ihdr = (struct rt0_hdr *) opt;
1115
1116 phdr = skb_push(skb, (ihdr->rt_hdr.hdrlen + 1) << 3);
1117 memcpy(phdr, ihdr, sizeof(struct rt0_hdr));
1118
1119 hops = ihdr->rt_hdr.hdrlen >> 1;
1120
1121 if (hops > 1)
1122 memcpy(phdr->addr, ihdr->addr + 1,
1123 (hops - 1) * sizeof(struct in6_addr));
1124
1125 phdr->addr[hops - 1] = **addr_p;
1126 *addr_p = ihdr->addr;
1127
1128 phdr->rt_hdr.nexthdr = *proto;
1129 *proto = NEXTHDR_ROUTING;
1130}
1131
1132static void ipv6_push_rthdr4(struct sk_buff *skb, u8 *proto,
1133 struct ipv6_rt_hdr *opt,
1134 struct in6_addr **addr_p, struct in6_addr *saddr)
1135{
1136 struct ipv6_sr_hdr *sr_phdr, *sr_ihdr;
1137 int plen, hops;
1138
1139 sr_ihdr = (struct ipv6_sr_hdr *)opt;
1140 plen = (sr_ihdr->hdrlen + 1) << 3;
1141
1142 sr_phdr = skb_push(skb, plen);
1143 memcpy(sr_phdr, sr_ihdr, sizeof(struct ipv6_sr_hdr));
1144
1145 hops = sr_ihdr->first_segment + 1;
1146 memcpy(sr_phdr->segments + 1, sr_ihdr->segments + 1,
1147 (hops - 1) * sizeof(struct in6_addr));
1148
1149 sr_phdr->segments[0] = **addr_p;
1150 *addr_p = &sr_ihdr->segments[sr_ihdr->segments_left];
1151
1152 if (sr_ihdr->hdrlen > hops * 2) {
1153 int tlvs_offset, tlvs_length;
1154
1155 tlvs_offset = (1 + hops * 2) << 3;
1156 tlvs_length = (sr_ihdr->hdrlen - hops * 2) << 3;
1157 memcpy((char *)sr_phdr + tlvs_offset,
1158 (char *)sr_ihdr + tlvs_offset, tlvs_length);
1159 }
1160
1161#ifdef CONFIG_IPV6_SEG6_HMAC
1162 if (sr_has_hmac(sr_phdr)) {
1163 struct net *net = NULL;
1164
1165 if (skb->dev)
1166 net = dev_net(skb->dev);
1167 else if (skb->sk)
1168 net = sock_net(skb->sk);
1169
1170 WARN_ON(!net);
1171
1172 if (net)
1173 seg6_push_hmac(net, saddr, sr_phdr);
1174 }
1175#endif
1176
1177 sr_phdr->nexthdr = *proto;
1178 *proto = NEXTHDR_ROUTING;
1179}
1180
1181static void ipv6_push_rthdr(struct sk_buff *skb, u8 *proto,
1182 struct ipv6_rt_hdr *opt,
1183 struct in6_addr **addr_p, struct in6_addr *saddr)
1184{
1185 switch (opt->type) {
1186 case IPV6_SRCRT_TYPE_0:
1187 case IPV6_SRCRT_STRICT:
1188 case IPV6_SRCRT_TYPE_2:
1189 ipv6_push_rthdr0(skb, proto, opt, addr_p, saddr);
1190 break;
1191 case IPV6_SRCRT_TYPE_4:
1192 ipv6_push_rthdr4(skb, proto, opt, addr_p, saddr);
1193 break;
1194 default:
1195 break;
1196 }
1197}
1198
1199static void ipv6_push_exthdr(struct sk_buff *skb, u8 *proto, u8 type, struct ipv6_opt_hdr *opt)
1200{
1201 struct ipv6_opt_hdr *h = skb_push(skb, ipv6_optlen(opt));
1202
1203 memcpy(h, opt, ipv6_optlen(opt));
1204 h->nexthdr = *proto;
1205 *proto = type;
1206}
1207
1208void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
1209 u8 *proto,
1210 struct in6_addr **daddr, struct in6_addr *saddr)
1211{
1212 if (opt->srcrt) {
1213 ipv6_push_rthdr(skb, proto, opt->srcrt, daddr, saddr);
1214 /*
1215 * IPV6_RTHDRDSTOPTS is ignored
1216 * unless IPV6_RTHDR is set (RFC3542).
1217 */
1218 if (opt->dst0opt)
1219 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst0opt);
1220 }
1221 if (opt->hopopt)
1222 ipv6_push_exthdr(skb, proto, NEXTHDR_HOP, opt->hopopt);
1223}
1224
1225void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, u8 *proto)
1226{
1227 if (opt->dst1opt)
1228 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst1opt);
1229}
1230EXPORT_SYMBOL(ipv6_push_frag_opts);
1231
1232struct ipv6_txoptions *
1233ipv6_dup_options(struct sock *sk, struct ipv6_txoptions *opt)
1234{
1235 struct ipv6_txoptions *opt2;
1236
1237 opt2 = sock_kmalloc(sk, opt->tot_len, GFP_ATOMIC);
1238 if (opt2) {
1239 long dif = (char *)opt2 - (char *)opt;
1240 memcpy(opt2, opt, opt->tot_len);
1241 if (opt2->hopopt)
1242 *((char **)&opt2->hopopt) += dif;
1243 if (opt2->dst0opt)
1244 *((char **)&opt2->dst0opt) += dif;
1245 if (opt2->dst1opt)
1246 *((char **)&opt2->dst1opt) += dif;
1247 if (opt2->srcrt)
1248 *((char **)&opt2->srcrt) += dif;
1249 refcount_set(&opt2->refcnt, 1);
1250 }
1251 return opt2;
1252}
1253EXPORT_SYMBOL_GPL(ipv6_dup_options);
1254
1255static void ipv6_renew_option(int renewtype,
1256 struct ipv6_opt_hdr **dest,
1257 struct ipv6_opt_hdr *old,
1258 struct ipv6_opt_hdr *new,
1259 int newtype, char **p)
1260{
1261 struct ipv6_opt_hdr *src;
1262
1263 src = (renewtype == newtype ? new : old);
1264 if (!src)
1265 return;
1266
1267 memcpy(*p, src, ipv6_optlen(src));
1268 *dest = (struct ipv6_opt_hdr *)*p;
1269 *p += CMSG_ALIGN(ipv6_optlen(*dest));
1270}
1271
1272/**
1273 * ipv6_renew_options - replace a specific ext hdr with a new one.
1274 *
1275 * @sk: sock from which to allocate memory
1276 * @opt: original options
1277 * @newtype: option type to replace in @opt
1278 * @newopt: new option of type @newtype to replace (user-mem)
1279 *
1280 * Returns a new set of options which is a copy of @opt with the
1281 * option type @newtype replaced with @newopt.
1282 *
1283 * @opt may be NULL, in which case a new set of options is returned
1284 * containing just @newopt.
1285 *
1286 * @newopt may be NULL, in which case the specified option type is
1287 * not copied into the new set of options.
1288 *
1289 * The new set of options is allocated from the socket option memory
1290 * buffer of @sk.
1291 */
1292struct ipv6_txoptions *
1293ipv6_renew_options(struct sock *sk, struct ipv6_txoptions *opt,
1294 int newtype, struct ipv6_opt_hdr *newopt)
1295{
1296 int tot_len = 0;
1297 char *p;
1298 struct ipv6_txoptions *opt2;
1299
1300 if (opt) {
1301 if (newtype != IPV6_HOPOPTS && opt->hopopt)
1302 tot_len += CMSG_ALIGN(ipv6_optlen(opt->hopopt));
1303 if (newtype != IPV6_RTHDRDSTOPTS && opt->dst0opt)
1304 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst0opt));
1305 if (newtype != IPV6_RTHDR && opt->srcrt)
1306 tot_len += CMSG_ALIGN(ipv6_optlen(opt->srcrt));
1307 if (newtype != IPV6_DSTOPTS && opt->dst1opt)
1308 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst1opt));
1309 }
1310
1311 if (newopt)
1312 tot_len += CMSG_ALIGN(ipv6_optlen(newopt));
1313
1314 if (!tot_len)
1315 return NULL;
1316
1317 tot_len += sizeof(*opt2);
1318 opt2 = sock_kmalloc(sk, tot_len, GFP_ATOMIC);
1319 if (!opt2)
1320 return ERR_PTR(-ENOBUFS);
1321
1322 memset(opt2, 0, tot_len);
1323 refcount_set(&opt2->refcnt, 1);
1324 opt2->tot_len = tot_len;
1325 p = (char *)(opt2 + 1);
1326
1327 ipv6_renew_option(IPV6_HOPOPTS, &opt2->hopopt,
1328 (opt ? opt->hopopt : NULL),
1329 newopt, newtype, &p);
1330 ipv6_renew_option(IPV6_RTHDRDSTOPTS, &opt2->dst0opt,
1331 (opt ? opt->dst0opt : NULL),
1332 newopt, newtype, &p);
1333 ipv6_renew_option(IPV6_RTHDR,
1334 (struct ipv6_opt_hdr **)&opt2->srcrt,
1335 (opt ? (struct ipv6_opt_hdr *)opt->srcrt : NULL),
1336 newopt, newtype, &p);
1337 ipv6_renew_option(IPV6_DSTOPTS, &opt2->dst1opt,
1338 (opt ? opt->dst1opt : NULL),
1339 newopt, newtype, &p);
1340
1341 opt2->opt_nflen = (opt2->hopopt ? ipv6_optlen(opt2->hopopt) : 0) +
1342 (opt2->dst0opt ? ipv6_optlen(opt2->dst0opt) : 0) +
1343 (opt2->srcrt ? ipv6_optlen(opt2->srcrt) : 0);
1344 opt2->opt_flen = (opt2->dst1opt ? ipv6_optlen(opt2->dst1opt) : 0);
1345
1346 return opt2;
1347}
1348
1349struct ipv6_txoptions *__ipv6_fixup_options(struct ipv6_txoptions *opt_space,
1350 struct ipv6_txoptions *opt)
1351{
1352 /*
1353 * ignore the dest before srcrt unless srcrt is being included.
1354 * --yoshfuji
1355 */
1356 if (opt->dst0opt && !opt->srcrt) {
1357 if (opt_space != opt) {
1358 memcpy(opt_space, opt, sizeof(*opt_space));
1359 opt = opt_space;
1360 }
1361 opt->opt_nflen -= ipv6_optlen(opt->dst0opt);
1362 opt->dst0opt = NULL;
1363 }
1364
1365 return opt;
1366}
1367EXPORT_SYMBOL_GPL(__ipv6_fixup_options);
1368
1369/**
1370 * fl6_update_dst - update flowi destination address with info given
1371 * by srcrt option, if any.
1372 *
1373 * @fl6: flowi6 for which daddr is to be updated
1374 * @opt: struct ipv6_txoptions in which to look for srcrt opt
1375 * @orig: copy of original daddr address if modified
1376 *
1377 * Returns NULL if no txoptions or no srcrt, otherwise returns orig
1378 * and initial value of fl6->daddr set in orig
1379 */
1380struct in6_addr *fl6_update_dst(struct flowi6 *fl6,
1381 const struct ipv6_txoptions *opt,
1382 struct in6_addr *orig)
1383{
1384 if (!opt || !opt->srcrt)
1385 return NULL;
1386
1387 *orig = fl6->daddr;
1388
1389 switch (opt->srcrt->type) {
1390 case IPV6_SRCRT_TYPE_0:
1391 case IPV6_SRCRT_STRICT:
1392 case IPV6_SRCRT_TYPE_2:
1393 fl6->daddr = *((struct rt0_hdr *)opt->srcrt)->addr;
1394 break;
1395 case IPV6_SRCRT_TYPE_4:
1396 {
1397 struct ipv6_sr_hdr *srh = (struct ipv6_sr_hdr *)opt->srcrt;
1398
1399 fl6->daddr = srh->segments[srh->segments_left];
1400 break;
1401 }
1402 default:
1403 return NULL;
1404 }
1405
1406 return orig;
1407}
1408EXPORT_SYMBOL_GPL(fl6_update_dst);