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
ip6_tlvopt_unknown(struct sk_buff * skb,int optoff,bool disallow_unknowns)64 static 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
98 drop:
99 kfree_skb_reason(skb, SKB_DROP_REASON_UNHANDLED_PROTO);
100 return false;
101 }
102
103 static bool ipv6_hop_ra(struct sk_buff *skb, int optoff);
104 static bool ipv6_hop_ioam(struct sk_buff *skb, int optoff);
105 static bool ipv6_hop_jumbo(struct sk_buff *skb, int optoff);
106 static bool ipv6_hop_calipso(struct sk_buff *skb, int optoff);
107 #if IS_ENABLED(CONFIG_IPV6_MIP6)
108 static 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
ip6_parse_tlv(bool hopbyhop,struct sk_buff * skb,int max_count)113 static 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 off += 2;
130 len -= 2;
131
132 while (len > 0) {
133 int optlen, i;
134
135 if (nh[off] == IPV6_TLV_PAD1) {
136 padlen++;
137 if (padlen > 7)
138 goto bad;
139 off++;
140 len--;
141 continue;
142 }
143 if (len < 2)
144 goto bad;
145 optlen = nh[off + 1] + 2;
146 if (optlen > len)
147 goto bad;
148
149 if (nh[off] == IPV6_TLV_PADN) {
150 /* RFC 2460 states that the purpose of PadN is
151 * to align the containing header to multiples
152 * of 8. 7 is therefore the highest valid value.
153 * See also RFC 4942, Section 2.1.9.5.
154 */
155 padlen += optlen;
156 if (padlen > 7)
157 goto bad;
158 /* RFC 4942 recommends receiving hosts to
159 * actively check PadN payload to contain
160 * only zeroes.
161 */
162 for (i = 2; i < optlen; i++) {
163 if (nh[off + i] != 0)
164 goto bad;
165 }
166 } else {
167 tlv_count++;
168 if (tlv_count > max_count)
169 goto bad;
170
171 if (hopbyhop) {
172 switch (nh[off]) {
173 case IPV6_TLV_ROUTERALERT:
174 if (!ipv6_hop_ra(skb, off))
175 return false;
176 break;
177 case IPV6_TLV_IOAM:
178 if (!ipv6_hop_ioam(skb, off))
179 return false;
180 break;
181 case IPV6_TLV_JUMBO:
182 if (!ipv6_hop_jumbo(skb, off))
183 return false;
184 break;
185 case IPV6_TLV_CALIPSO:
186 if (!ipv6_hop_calipso(skb, off))
187 return false;
188 break;
189 default:
190 if (!ip6_tlvopt_unknown(skb, off,
191 disallow_unknowns))
192 return false;
193 break;
194 }
195 } else {
196 switch (nh[off]) {
197 #if IS_ENABLED(CONFIG_IPV6_MIP6)
198 case IPV6_TLV_HAO:
199 if (!ipv6_dest_hao(skb, off))
200 return false;
201 break;
202 #endif
203 default:
204 if (!ip6_tlvopt_unknown(skb, off,
205 disallow_unknowns))
206 return false;
207 break;
208 }
209 }
210 padlen = 0;
211 }
212 off += optlen;
213 len -= optlen;
214 }
215
216 if (len == 0)
217 return true;
218 bad:
219 kfree_skb_reason(skb, SKB_DROP_REASON_IP_INHDR);
220 return false;
221 }
222
223 /*****************************
224 Destination options header.
225 *****************************/
226
227 #if IS_ENABLED(CONFIG_IPV6_MIP6)
ipv6_dest_hao(struct sk_buff * skb,int optoff)228 static 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 SKB_DR(reason);
234 int ret;
235
236 if (opt->dsthao) {
237 net_dbg_ratelimited("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 net_dbg_ratelimited("hao invalid option length = %d\n",
247 hao->length);
248 SKB_DR_SET(reason, IP_INHDR);
249 goto discard;
250 }
251
252 if (!(ipv6_addr_type(&hao->addr) & IPV6_ADDR_UNICAST)) {
253 net_dbg_ratelimited("hao is not an unicast addr: %pI6\n",
254 &hao->addr);
255 SKB_DR_SET(reason, INVALID_PROTO);
256 goto discard;
257 }
258
259 ret = xfrm6_input_addr(skb, (xfrm_address_t *)&ipv6h->daddr,
260 (xfrm_address_t *)&hao->addr, IPPROTO_DSTOPTS);
261 if (unlikely(ret < 0)) {
262 SKB_DR_SET(reason, XFRM_POLICY);
263 goto discard;
264 }
265
266 if (skb_cloned(skb)) {
267 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
268 goto discard;
269
270 /* update all variable using below by copied skbuff */
271 hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) +
272 optoff);
273 ipv6h = ipv6_hdr(skb);
274 }
275
276 if (skb->ip_summed == CHECKSUM_COMPLETE)
277 skb->ip_summed = CHECKSUM_NONE;
278
279 swap(ipv6h->saddr, hao->addr);
280
281 if (skb->tstamp == 0)
282 __net_timestamp(skb);
283
284 return true;
285
286 discard:
287 kfree_skb_reason(skb, reason);
288 return false;
289 }
290 #endif
291
ipv6_destopt_rcv(struct sk_buff * skb)292 static int ipv6_destopt_rcv(struct sk_buff *skb)
293 {
294 struct inet6_dev *idev = __in6_dev_get(skb->dev);
295 struct inet6_skb_parm *opt = IP6CB(skb);
296 #if IS_ENABLED(CONFIG_IPV6_MIP6)
297 __u16 dstbuf;
298 #endif
299 struct dst_entry *dst = skb_dst(skb);
300 struct net *net = dev_net(skb->dev);
301 int extlen;
302
303 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
304 !pskb_may_pull(skb, (skb_transport_offset(skb) +
305 ((skb_transport_header(skb)[1] + 1) << 3)))) {
306 __IP6_INC_STATS(dev_net(dst->dev), idev,
307 IPSTATS_MIB_INHDRERRORS);
308 fail_and_free:
309 kfree_skb(skb);
310 return -1;
311 }
312
313 extlen = (skb_transport_header(skb)[1] + 1) << 3;
314 if (extlen > net->ipv6.sysctl.max_dst_opts_len)
315 goto fail_and_free;
316
317 opt->lastopt = opt->dst1 = skb_network_header_len(skb);
318 #if IS_ENABLED(CONFIG_IPV6_MIP6)
319 dstbuf = opt->dst1;
320 #endif
321
322 if (ip6_parse_tlv(false, skb, net->ipv6.sysctl.max_dst_opts_cnt)) {
323 skb->transport_header += extlen;
324 opt = IP6CB(skb);
325 #if IS_ENABLED(CONFIG_IPV6_MIP6)
326 opt->nhoff = dstbuf;
327 #else
328 opt->nhoff = opt->dst1;
329 #endif
330 return 1;
331 }
332
333 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
334 return -1;
335 }
336
seg6_update_csum(struct sk_buff * skb)337 static void seg6_update_csum(struct sk_buff *skb)
338 {
339 struct ipv6_sr_hdr *hdr;
340 struct in6_addr *addr;
341 __be32 from, to;
342
343 /* srh is at transport offset and seg_left is already decremented
344 * but daddr is not yet updated with next segment
345 */
346
347 hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb);
348 addr = hdr->segments + hdr->segments_left;
349
350 hdr->segments_left++;
351 from = *(__be32 *)hdr;
352
353 hdr->segments_left--;
354 to = *(__be32 *)hdr;
355
356 /* update skb csum with diff resulting from seg_left decrement */
357
358 update_csum_diff4(skb, from, to);
359
360 /* compute csum diff between current and next segment and update */
361
362 update_csum_diff16(skb, (__be32 *)(&ipv6_hdr(skb)->daddr),
363 (__be32 *)addr);
364 }
365
ipv6_srh_rcv(struct sk_buff * skb)366 static int ipv6_srh_rcv(struct sk_buff *skb)
367 {
368 struct inet6_skb_parm *opt = IP6CB(skb);
369 struct net *net = dev_net(skb->dev);
370 struct ipv6_sr_hdr *hdr;
371 struct inet6_dev *idev;
372 struct in6_addr *addr;
373 int accept_seg6;
374
375 hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb);
376
377 idev = __in6_dev_get(skb->dev);
378
379 accept_seg6 = net->ipv6.devconf_all->seg6_enabled;
380 if (accept_seg6 > idev->cnf.seg6_enabled)
381 accept_seg6 = idev->cnf.seg6_enabled;
382
383 if (!accept_seg6) {
384 kfree_skb(skb);
385 return -1;
386 }
387
388 #ifdef CONFIG_IPV6_SEG6_HMAC
389 if (!seg6_hmac_validate_skb(skb)) {
390 kfree_skb(skb);
391 return -1;
392 }
393 #endif
394
395 looped_back:
396 if (hdr->segments_left == 0) {
397 if (hdr->nexthdr == NEXTHDR_IPV6 || hdr->nexthdr == NEXTHDR_IPV4) {
398 int offset = (hdr->hdrlen + 1) << 3;
399
400 skb_postpull_rcsum(skb, skb_network_header(skb),
401 skb_network_header_len(skb));
402 skb_pull(skb, offset);
403 skb_postpull_rcsum(skb, skb_transport_header(skb),
404 offset);
405
406 skb_reset_network_header(skb);
407 skb_reset_transport_header(skb);
408 skb->encapsulation = 0;
409 if (hdr->nexthdr == NEXTHDR_IPV4)
410 skb->protocol = htons(ETH_P_IP);
411 __skb_tunnel_rx(skb, skb->dev, net);
412
413 netif_rx(skb);
414 return -1;
415 }
416
417 opt->srcrt = skb_network_header_len(skb);
418 opt->lastopt = opt->srcrt;
419 skb->transport_header += (hdr->hdrlen + 1) << 3;
420 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb);
421
422 return 1;
423 }
424
425 if (hdr->segments_left >= (hdr->hdrlen >> 1)) {
426 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
427 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
428 ((&hdr->segments_left) -
429 skb_network_header(skb)));
430 return -1;
431 }
432
433 if (skb_cloned(skb)) {
434 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) {
435 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
436 IPSTATS_MIB_OUTDISCARDS);
437 kfree_skb(skb);
438 return -1;
439 }
440
441 hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb);
442 }
443
444 hdr->segments_left--;
445 addr = hdr->segments + hdr->segments_left;
446
447 skb_push(skb, sizeof(struct ipv6hdr));
448
449 if (skb->ip_summed == CHECKSUM_COMPLETE)
450 seg6_update_csum(skb);
451
452 ipv6_hdr(skb)->daddr = *addr;
453
454 ip6_route_input(skb);
455
456 if (skb_dst(skb)->error) {
457 dst_input(skb);
458 return -1;
459 }
460
461 if (skb_dst(skb)->dev->flags & IFF_LOOPBACK) {
462 if (ipv6_hdr(skb)->hop_limit <= 1) {
463 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
464 icmpv6_send(skb, ICMPV6_TIME_EXCEED,
465 ICMPV6_EXC_HOPLIMIT, 0);
466 kfree_skb(skb);
467 return -1;
468 }
469 ipv6_hdr(skb)->hop_limit--;
470
471 skb_pull(skb, sizeof(struct ipv6hdr));
472 goto looped_back;
473 }
474
475 dst_input(skb);
476
477 return -1;
478 }
479
ipv6_rpl_srh_rcv(struct sk_buff * skb)480 static int ipv6_rpl_srh_rcv(struct sk_buff *skb)
481 {
482 struct ipv6_rpl_sr_hdr *hdr, *ohdr, *chdr;
483 struct inet6_skb_parm *opt = IP6CB(skb);
484 struct net *net = dev_net(skb->dev);
485 struct inet6_dev *idev;
486 struct ipv6hdr *oldhdr;
487 unsigned char *buf;
488 int accept_rpl_seg;
489 int i, err;
490 u64 n = 0;
491 u32 r;
492
493 idev = __in6_dev_get(skb->dev);
494
495 accept_rpl_seg = net->ipv6.devconf_all->rpl_seg_enabled;
496 if (accept_rpl_seg > idev->cnf.rpl_seg_enabled)
497 accept_rpl_seg = idev->cnf.rpl_seg_enabled;
498
499 if (!accept_rpl_seg) {
500 kfree_skb(skb);
501 return -1;
502 }
503
504 looped_back:
505 hdr = (struct ipv6_rpl_sr_hdr *)skb_transport_header(skb);
506
507 if (hdr->segments_left == 0) {
508 if (hdr->nexthdr == NEXTHDR_IPV6) {
509 int offset = (hdr->hdrlen + 1) << 3;
510
511 skb_postpull_rcsum(skb, skb_network_header(skb),
512 skb_network_header_len(skb));
513 skb_pull(skb, offset);
514 skb_postpull_rcsum(skb, skb_transport_header(skb),
515 offset);
516
517 skb_reset_network_header(skb);
518 skb_reset_transport_header(skb);
519 skb->encapsulation = 0;
520
521 __skb_tunnel_rx(skb, skb->dev, net);
522
523 netif_rx(skb);
524 return -1;
525 }
526
527 opt->srcrt = skb_network_header_len(skb);
528 opt->lastopt = opt->srcrt;
529 skb->transport_header += (hdr->hdrlen + 1) << 3;
530 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb);
531
532 return 1;
533 }
534
535 n = (hdr->hdrlen << 3) - hdr->pad - (16 - hdr->cmpre);
536 r = do_div(n, (16 - hdr->cmpri));
537 /* checks if calculation was without remainder and n fits into
538 * unsigned char which is segments_left field. Should not be
539 * higher than that.
540 */
541 if (r || (n + 1) > 255) {
542 kfree_skb(skb);
543 return -1;
544 }
545
546 if (hdr->segments_left > n + 1) {
547 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
548 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
549 ((&hdr->segments_left) -
550 skb_network_header(skb)));
551 return -1;
552 }
553
554 hdr->segments_left--;
555 i = n - hdr->segments_left;
556
557 buf = kcalloc(struct_size(hdr, segments.addr, n + 2), 2, GFP_ATOMIC);
558 if (unlikely(!buf)) {
559 kfree_skb(skb);
560 return -1;
561 }
562
563 ohdr = (struct ipv6_rpl_sr_hdr *)buf;
564 ipv6_rpl_srh_decompress(ohdr, hdr, &ipv6_hdr(skb)->daddr, n);
565 chdr = (struct ipv6_rpl_sr_hdr *)(buf + ((ohdr->hdrlen + 1) << 3));
566
567 if (ipv6_addr_is_multicast(&ohdr->rpl_segaddr[i])) {
568 kfree_skb(skb);
569 kfree(buf);
570 return -1;
571 }
572
573 err = ipv6_chk_rpl_srh_loop(net, ohdr->rpl_segaddr, n + 1);
574 if (err) {
575 icmpv6_send(skb, ICMPV6_PARAMPROB, 0, 0);
576 kfree_skb(skb);
577 kfree(buf);
578 return -1;
579 }
580
581 swap(ipv6_hdr(skb)->daddr, ohdr->rpl_segaddr[i]);
582
583 ipv6_rpl_srh_compress(chdr, ohdr, &ipv6_hdr(skb)->daddr, n);
584
585 oldhdr = ipv6_hdr(skb);
586
587 skb_pull(skb, ((hdr->hdrlen + 1) << 3));
588 skb_postpull_rcsum(skb, oldhdr,
589 sizeof(struct ipv6hdr) + ((hdr->hdrlen + 1) << 3));
590 if (unlikely(!hdr->segments_left)) {
591 if (pskb_expand_head(skb, sizeof(struct ipv6hdr) + ((chdr->hdrlen + 1) << 3), 0,
592 GFP_ATOMIC)) {
593 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_OUTDISCARDS);
594 kfree_skb(skb);
595 kfree(buf);
596 return -1;
597 }
598
599 oldhdr = ipv6_hdr(skb);
600 }
601 skb_push(skb, ((chdr->hdrlen + 1) << 3) + sizeof(struct ipv6hdr));
602 skb_reset_network_header(skb);
603 skb_mac_header_rebuild(skb);
604 skb_set_transport_header(skb, sizeof(struct ipv6hdr));
605
606 memmove(ipv6_hdr(skb), oldhdr, sizeof(struct ipv6hdr));
607 memcpy(skb_transport_header(skb), chdr, (chdr->hdrlen + 1) << 3);
608
609 ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
610 skb_postpush_rcsum(skb, ipv6_hdr(skb),
611 sizeof(struct ipv6hdr) + ((chdr->hdrlen + 1) << 3));
612
613 kfree(buf);
614
615 ip6_route_input(skb);
616
617 if (skb_dst(skb)->error) {
618 dst_input(skb);
619 return -1;
620 }
621
622 if (skb_dst(skb)->dev->flags & IFF_LOOPBACK) {
623 if (ipv6_hdr(skb)->hop_limit <= 1) {
624 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
625 icmpv6_send(skb, ICMPV6_TIME_EXCEED,
626 ICMPV6_EXC_HOPLIMIT, 0);
627 kfree_skb(skb);
628 return -1;
629 }
630 ipv6_hdr(skb)->hop_limit--;
631
632 skb_pull(skb, sizeof(struct ipv6hdr));
633 goto looped_back;
634 }
635
636 dst_input(skb);
637
638 return -1;
639 }
640
641 /********************************
642 Routing header.
643 ********************************/
644
645 /* called with rcu_read_lock() */
ipv6_rthdr_rcv(struct sk_buff * skb)646 static int ipv6_rthdr_rcv(struct sk_buff *skb)
647 {
648 struct inet6_dev *idev = __in6_dev_get(skb->dev);
649 struct inet6_skb_parm *opt = IP6CB(skb);
650 struct in6_addr *addr = NULL;
651 int n, i;
652 struct ipv6_rt_hdr *hdr;
653 struct rt0_hdr *rthdr;
654 struct net *net = dev_net(skb->dev);
655 int accept_source_route = net->ipv6.devconf_all->accept_source_route;
656
657 if (idev && accept_source_route > idev->cnf.accept_source_route)
658 accept_source_route = idev->cnf.accept_source_route;
659
660 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
661 !pskb_may_pull(skb, (skb_transport_offset(skb) +
662 ((skb_transport_header(skb)[1] + 1) << 3)))) {
663 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
664 kfree_skb(skb);
665 return -1;
666 }
667
668 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb);
669
670 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) ||
671 skb->pkt_type != PACKET_HOST) {
672 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
673 kfree_skb(skb);
674 return -1;
675 }
676
677 switch (hdr->type) {
678 case IPV6_SRCRT_TYPE_4:
679 /* segment routing */
680 return ipv6_srh_rcv(skb);
681 case IPV6_SRCRT_TYPE_3:
682 /* rpl segment routing */
683 return ipv6_rpl_srh_rcv(skb);
684 default:
685 break;
686 }
687
688 looped_back:
689 if (hdr->segments_left == 0) {
690 switch (hdr->type) {
691 #if IS_ENABLED(CONFIG_IPV6_MIP6)
692 case IPV6_SRCRT_TYPE_2:
693 /* Silently discard type 2 header unless it was
694 * processed by own
695 */
696 if (!addr) {
697 __IP6_INC_STATS(net, idev,
698 IPSTATS_MIB_INADDRERRORS);
699 kfree_skb(skb);
700 return -1;
701 }
702 break;
703 #endif
704 default:
705 break;
706 }
707
708 opt->lastopt = opt->srcrt = skb_network_header_len(skb);
709 skb->transport_header += (hdr->hdrlen + 1) << 3;
710 opt->dst0 = opt->dst1;
711 opt->dst1 = 0;
712 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb);
713 return 1;
714 }
715
716 switch (hdr->type) {
717 #if IS_ENABLED(CONFIG_IPV6_MIP6)
718 case IPV6_SRCRT_TYPE_2:
719 if (accept_source_route < 0)
720 goto unknown_rh;
721 /* Silently discard invalid RTH type 2 */
722 if (hdr->hdrlen != 2 || hdr->segments_left != 1) {
723 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
724 kfree_skb(skb);
725 return -1;
726 }
727 break;
728 #endif
729 default:
730 goto unknown_rh;
731 }
732
733 /*
734 * This is the routing header forwarding algorithm from
735 * RFC 2460, page 16.
736 */
737
738 n = hdr->hdrlen >> 1;
739
740 if (hdr->segments_left > n) {
741 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
742 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
743 ((&hdr->segments_left) -
744 skb_network_header(skb)));
745 return -1;
746 }
747
748 /* We are about to mangle packet header. Be careful!
749 Do not damage packets queued somewhere.
750 */
751 if (skb_cloned(skb)) {
752 /* the copy is a forwarded packet */
753 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) {
754 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
755 IPSTATS_MIB_OUTDISCARDS);
756 kfree_skb(skb);
757 return -1;
758 }
759 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb);
760 }
761
762 if (skb->ip_summed == CHECKSUM_COMPLETE)
763 skb->ip_summed = CHECKSUM_NONE;
764
765 i = n - --hdr->segments_left;
766
767 rthdr = (struct rt0_hdr *) hdr;
768 addr = rthdr->addr;
769 addr += i - 1;
770
771 switch (hdr->type) {
772 #if IS_ENABLED(CONFIG_IPV6_MIP6)
773 case IPV6_SRCRT_TYPE_2:
774 if (xfrm6_input_addr(skb, (xfrm_address_t *)addr,
775 (xfrm_address_t *)&ipv6_hdr(skb)->saddr,
776 IPPROTO_ROUTING) < 0) {
777 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
778 kfree_skb(skb);
779 return -1;
780 }
781 if (!ipv6_chk_home_addr(dev_net(skb_dst(skb)->dev), addr)) {
782 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
783 kfree_skb(skb);
784 return -1;
785 }
786 break;
787 #endif
788 default:
789 break;
790 }
791
792 if (ipv6_addr_is_multicast(addr)) {
793 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
794 kfree_skb(skb);
795 return -1;
796 }
797
798 swap(*addr, ipv6_hdr(skb)->daddr);
799
800 ip6_route_input(skb);
801 if (skb_dst(skb)->error) {
802 skb_push(skb, skb->data - skb_network_header(skb));
803 dst_input(skb);
804 return -1;
805 }
806
807 if (skb_dst(skb)->dev->flags&IFF_LOOPBACK) {
808 if (ipv6_hdr(skb)->hop_limit <= 1) {
809 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
810 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
811 0);
812 kfree_skb(skb);
813 return -1;
814 }
815 ipv6_hdr(skb)->hop_limit--;
816 goto looped_back;
817 }
818
819 skb_push(skb, skb->data - skb_network_header(skb));
820 dst_input(skb);
821 return -1;
822
823 unknown_rh:
824 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
825 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
826 (&hdr->type) - skb_network_header(skb));
827 return -1;
828 }
829
830 static const struct inet6_protocol rthdr_protocol = {
831 .handler = ipv6_rthdr_rcv,
832 .flags = INET6_PROTO_NOPOLICY,
833 };
834
835 static const struct inet6_protocol destopt_protocol = {
836 .handler = ipv6_destopt_rcv,
837 .flags = INET6_PROTO_NOPOLICY,
838 };
839
840 static const struct inet6_protocol nodata_protocol = {
841 .handler = dst_discard,
842 .flags = INET6_PROTO_NOPOLICY,
843 };
844
ipv6_exthdrs_init(void)845 int __init ipv6_exthdrs_init(void)
846 {
847 int ret;
848
849 ret = inet6_add_protocol(&rthdr_protocol, IPPROTO_ROUTING);
850 if (ret)
851 goto out;
852
853 ret = inet6_add_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
854 if (ret)
855 goto out_rthdr;
856
857 ret = inet6_add_protocol(&nodata_protocol, IPPROTO_NONE);
858 if (ret)
859 goto out_destopt;
860
861 out:
862 return ret;
863 out_destopt:
864 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
865 out_rthdr:
866 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING);
867 goto out;
868 };
869
ipv6_exthdrs_exit(void)870 void ipv6_exthdrs_exit(void)
871 {
872 inet6_del_protocol(&nodata_protocol, IPPROTO_NONE);
873 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
874 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING);
875 }
876
877 /**********************************
878 Hop-by-hop options.
879 **********************************/
880
881 /*
882 * Note: we cannot rely on skb_dst(skb) before we assign it in ip6_route_input().
883 */
ipv6_skb_net(struct sk_buff * skb)884 static inline struct net *ipv6_skb_net(struct sk_buff *skb)
885 {
886 return skb_dst(skb) ? dev_net(skb_dst(skb)->dev) : dev_net(skb->dev);
887 }
888
889 /* Router Alert as of RFC 2711 */
890
ipv6_hop_ra(struct sk_buff * skb,int optoff)891 static bool ipv6_hop_ra(struct sk_buff *skb, int optoff)
892 {
893 const unsigned char *nh = skb_network_header(skb);
894
895 if (nh[optoff + 1] == 2) {
896 IP6CB(skb)->flags |= IP6SKB_ROUTERALERT;
897 memcpy(&IP6CB(skb)->ra, nh + optoff + 2, sizeof(IP6CB(skb)->ra));
898 return true;
899 }
900 net_dbg_ratelimited("ipv6_hop_ra: wrong RA length %d\n",
901 nh[optoff + 1]);
902 kfree_skb_reason(skb, SKB_DROP_REASON_IP_INHDR);
903 return false;
904 }
905
906 /* IOAM */
907
ipv6_hop_ioam(struct sk_buff * skb,int optoff)908 static bool ipv6_hop_ioam(struct sk_buff *skb, int optoff)
909 {
910 struct ioam6_trace_hdr *trace;
911 struct ioam6_namespace *ns;
912 struct ioam6_hdr *hdr;
913
914 /* Bad alignment (must be 4n-aligned) */
915 if (optoff & 3)
916 goto drop;
917
918 /* Ignore if IOAM is not enabled on ingress */
919 if (!__in6_dev_get(skb->dev)->cnf.ioam6_enabled)
920 goto ignore;
921
922 /* Truncated Option header */
923 hdr = (struct ioam6_hdr *)(skb_network_header(skb) + optoff);
924 if (hdr->opt_len < 2)
925 goto drop;
926
927 switch (hdr->type) {
928 case IOAM6_TYPE_PREALLOC:
929 /* Truncated Pre-allocated Trace header */
930 if (hdr->opt_len < 2 + sizeof(*trace))
931 goto drop;
932
933 /* Malformed Pre-allocated Trace header */
934 trace = (struct ioam6_trace_hdr *)((u8 *)hdr + sizeof(*hdr));
935 if (hdr->opt_len < 2 + sizeof(*trace) + trace->remlen * 4)
936 goto drop;
937
938 /* Ignore if the IOAM namespace is unknown */
939 ns = ioam6_namespace(ipv6_skb_net(skb), trace->namespace_id);
940 if (!ns)
941 goto ignore;
942
943 if (!skb_valid_dst(skb))
944 ip6_route_input(skb);
945
946 ioam6_fill_trace_data(skb, ns, trace, true);
947 break;
948 default:
949 break;
950 }
951
952 ignore:
953 return true;
954
955 drop:
956 kfree_skb_reason(skb, SKB_DROP_REASON_IP_INHDR);
957 return false;
958 }
959
960 /* Jumbo payload */
961
ipv6_hop_jumbo(struct sk_buff * skb,int optoff)962 static bool ipv6_hop_jumbo(struct sk_buff *skb, int optoff)
963 {
964 const unsigned char *nh = skb_network_header(skb);
965 SKB_DR(reason);
966 u32 pkt_len;
967
968 if (nh[optoff + 1] != 4 || (optoff & 3) != 2) {
969 net_dbg_ratelimited("ipv6_hop_jumbo: wrong jumbo opt length/alignment %d\n",
970 nh[optoff+1]);
971 SKB_DR_SET(reason, IP_INHDR);
972 goto drop;
973 }
974
975 pkt_len = ntohl(*(__be32 *)(nh + optoff + 2));
976 if (pkt_len <= IPV6_MAXPLEN) {
977 icmpv6_param_prob_reason(skb, ICMPV6_HDR_FIELD, optoff + 2,
978 SKB_DROP_REASON_IP_INHDR);
979 return false;
980 }
981 if (ipv6_hdr(skb)->payload_len) {
982 icmpv6_param_prob_reason(skb, ICMPV6_HDR_FIELD, optoff,
983 SKB_DROP_REASON_IP_INHDR);
984 return false;
985 }
986
987 if (pkt_len > skb->len - sizeof(struct ipv6hdr)) {
988 SKB_DR_SET(reason, PKT_TOO_SMALL);
989 goto drop;
990 }
991
992 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr)))
993 goto drop;
994
995 IP6CB(skb)->flags |= IP6SKB_JUMBOGRAM;
996 return true;
997
998 drop:
999 kfree_skb_reason(skb, reason);
1000 return false;
1001 }
1002
1003 /* CALIPSO RFC 5570 */
1004
ipv6_hop_calipso(struct sk_buff * skb,int optoff)1005 static bool ipv6_hop_calipso(struct sk_buff *skb, int optoff)
1006 {
1007 const unsigned char *nh = skb_network_header(skb);
1008
1009 if (nh[optoff + 1] < 8)
1010 goto drop;
1011
1012 if (nh[optoff + 6] * 4 + 8 > nh[optoff + 1])
1013 goto drop;
1014
1015 if (!calipso_validate(skb, nh + optoff))
1016 goto drop;
1017
1018 return true;
1019
1020 drop:
1021 kfree_skb_reason(skb, SKB_DROP_REASON_IP_INHDR);
1022 return false;
1023 }
1024
ipv6_parse_hopopts(struct sk_buff * skb)1025 int ipv6_parse_hopopts(struct sk_buff *skb)
1026 {
1027 struct inet6_skb_parm *opt = IP6CB(skb);
1028 struct net *net = dev_net(skb->dev);
1029 int extlen;
1030
1031 /*
1032 * skb_network_header(skb) is equal to skb->data, and
1033 * skb_network_header_len(skb) is always equal to
1034 * sizeof(struct ipv6hdr) by definition of
1035 * hop-by-hop options.
1036 */
1037 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + 8) ||
1038 !pskb_may_pull(skb, (sizeof(struct ipv6hdr) +
1039 ((skb_transport_header(skb)[1] + 1) << 3)))) {
1040 fail_and_free:
1041 kfree_skb(skb);
1042 return -1;
1043 }
1044
1045 extlen = (skb_transport_header(skb)[1] + 1) << 3;
1046 if (extlen > net->ipv6.sysctl.max_hbh_opts_len)
1047 goto fail_and_free;
1048
1049 opt->flags |= IP6SKB_HOPBYHOP;
1050 if (ip6_parse_tlv(true, skb, net->ipv6.sysctl.max_hbh_opts_cnt)) {
1051 skb->transport_header += extlen;
1052 opt = IP6CB(skb);
1053 opt->nhoff = sizeof(struct ipv6hdr);
1054 return 1;
1055 }
1056 return -1;
1057 }
1058
1059 /*
1060 * Creating outbound headers.
1061 *
1062 * "build" functions work when skb is filled from head to tail (datagram)
1063 * "push" functions work when headers are added from tail to head (tcp)
1064 *
1065 * In both cases we assume, that caller reserved enough room
1066 * for headers.
1067 */
1068
ipv6_push_rthdr0(struct sk_buff * skb,u8 * proto,struct ipv6_rt_hdr * opt,struct in6_addr ** addr_p,struct in6_addr * saddr)1069 static void ipv6_push_rthdr0(struct sk_buff *skb, u8 *proto,
1070 struct ipv6_rt_hdr *opt,
1071 struct in6_addr **addr_p, struct in6_addr *saddr)
1072 {
1073 struct rt0_hdr *phdr, *ihdr;
1074 int hops;
1075
1076 ihdr = (struct rt0_hdr *) opt;
1077
1078 phdr = skb_push(skb, (ihdr->rt_hdr.hdrlen + 1) << 3);
1079 memcpy(phdr, ihdr, sizeof(struct rt0_hdr));
1080
1081 hops = ihdr->rt_hdr.hdrlen >> 1;
1082
1083 if (hops > 1)
1084 memcpy(phdr->addr, ihdr->addr + 1,
1085 (hops - 1) * sizeof(struct in6_addr));
1086
1087 phdr->addr[hops - 1] = **addr_p;
1088 *addr_p = ihdr->addr;
1089
1090 phdr->rt_hdr.nexthdr = *proto;
1091 *proto = NEXTHDR_ROUTING;
1092 }
1093
ipv6_push_rthdr4(struct sk_buff * skb,u8 * proto,struct ipv6_rt_hdr * opt,struct in6_addr ** addr_p,struct in6_addr * saddr)1094 static void ipv6_push_rthdr4(struct sk_buff *skb, u8 *proto,
1095 struct ipv6_rt_hdr *opt,
1096 struct in6_addr **addr_p, struct in6_addr *saddr)
1097 {
1098 struct ipv6_sr_hdr *sr_phdr, *sr_ihdr;
1099 int plen, hops;
1100
1101 sr_ihdr = (struct ipv6_sr_hdr *)opt;
1102 plen = (sr_ihdr->hdrlen + 1) << 3;
1103
1104 sr_phdr = skb_push(skb, plen);
1105 memcpy(sr_phdr, sr_ihdr, sizeof(struct ipv6_sr_hdr));
1106
1107 hops = sr_ihdr->first_segment + 1;
1108 memcpy(sr_phdr->segments + 1, sr_ihdr->segments + 1,
1109 (hops - 1) * sizeof(struct in6_addr));
1110
1111 sr_phdr->segments[0] = **addr_p;
1112 *addr_p = &sr_ihdr->segments[sr_ihdr->segments_left];
1113
1114 if (sr_ihdr->hdrlen > hops * 2) {
1115 int tlvs_offset, tlvs_length;
1116
1117 tlvs_offset = (1 + hops * 2) << 3;
1118 tlvs_length = (sr_ihdr->hdrlen - hops * 2) << 3;
1119 memcpy((char *)sr_phdr + tlvs_offset,
1120 (char *)sr_ihdr + tlvs_offset, tlvs_length);
1121 }
1122
1123 #ifdef CONFIG_IPV6_SEG6_HMAC
1124 if (sr_has_hmac(sr_phdr)) {
1125 struct net *net = NULL;
1126
1127 if (skb->dev)
1128 net = dev_net(skb->dev);
1129 else if (skb->sk)
1130 net = sock_net(skb->sk);
1131
1132 WARN_ON(!net);
1133
1134 if (net)
1135 seg6_push_hmac(net, saddr, sr_phdr);
1136 }
1137 #endif
1138
1139 sr_phdr->nexthdr = *proto;
1140 *proto = NEXTHDR_ROUTING;
1141 }
1142
ipv6_push_rthdr(struct sk_buff * skb,u8 * proto,struct ipv6_rt_hdr * opt,struct in6_addr ** addr_p,struct in6_addr * saddr)1143 static void ipv6_push_rthdr(struct sk_buff *skb, u8 *proto,
1144 struct ipv6_rt_hdr *opt,
1145 struct in6_addr **addr_p, struct in6_addr *saddr)
1146 {
1147 switch (opt->type) {
1148 case IPV6_SRCRT_TYPE_0:
1149 case IPV6_SRCRT_STRICT:
1150 case IPV6_SRCRT_TYPE_2:
1151 ipv6_push_rthdr0(skb, proto, opt, addr_p, saddr);
1152 break;
1153 case IPV6_SRCRT_TYPE_4:
1154 ipv6_push_rthdr4(skb, proto, opt, addr_p, saddr);
1155 break;
1156 default:
1157 break;
1158 }
1159 }
1160
ipv6_push_exthdr(struct sk_buff * skb,u8 * proto,u8 type,struct ipv6_opt_hdr * opt)1161 static void ipv6_push_exthdr(struct sk_buff *skb, u8 *proto, u8 type, struct ipv6_opt_hdr *opt)
1162 {
1163 struct ipv6_opt_hdr *h = skb_push(skb, ipv6_optlen(opt));
1164
1165 memcpy(h, opt, ipv6_optlen(opt));
1166 h->nexthdr = *proto;
1167 *proto = type;
1168 }
1169
ipv6_push_nfrag_opts(struct sk_buff * skb,struct ipv6_txoptions * opt,u8 * proto,struct in6_addr ** daddr,struct in6_addr * saddr)1170 void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
1171 u8 *proto,
1172 struct in6_addr **daddr, struct in6_addr *saddr)
1173 {
1174 if (opt->srcrt) {
1175 ipv6_push_rthdr(skb, proto, opt->srcrt, daddr, saddr);
1176 /*
1177 * IPV6_RTHDRDSTOPTS is ignored
1178 * unless IPV6_RTHDR is set (RFC3542).
1179 */
1180 if (opt->dst0opt)
1181 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst0opt);
1182 }
1183 if (opt->hopopt)
1184 ipv6_push_exthdr(skb, proto, NEXTHDR_HOP, opt->hopopt);
1185 }
1186
ipv6_push_frag_opts(struct sk_buff * skb,struct ipv6_txoptions * opt,u8 * proto)1187 void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, u8 *proto)
1188 {
1189 if (opt->dst1opt)
1190 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst1opt);
1191 }
1192 EXPORT_SYMBOL(ipv6_push_frag_opts);
1193
1194 struct ipv6_txoptions *
ipv6_dup_options(struct sock * sk,struct ipv6_txoptions * opt)1195 ipv6_dup_options(struct sock *sk, struct ipv6_txoptions *opt)
1196 {
1197 struct ipv6_txoptions *opt2;
1198
1199 opt2 = sock_kmalloc(sk, opt->tot_len, GFP_ATOMIC);
1200 if (opt2) {
1201 long dif = (char *)opt2 - (char *)opt;
1202 memcpy(opt2, opt, opt->tot_len);
1203 if (opt2->hopopt)
1204 *((char **)&opt2->hopopt) += dif;
1205 if (opt2->dst0opt)
1206 *((char **)&opt2->dst0opt) += dif;
1207 if (opt2->dst1opt)
1208 *((char **)&opt2->dst1opt) += dif;
1209 if (opt2->srcrt)
1210 *((char **)&opt2->srcrt) += dif;
1211 refcount_set(&opt2->refcnt, 1);
1212 }
1213 return opt2;
1214 }
1215 EXPORT_SYMBOL_GPL(ipv6_dup_options);
1216
ipv6_renew_option(int renewtype,struct ipv6_opt_hdr ** dest,struct ipv6_opt_hdr * old,struct ipv6_opt_hdr * new,int newtype,char ** p)1217 static void ipv6_renew_option(int renewtype,
1218 struct ipv6_opt_hdr **dest,
1219 struct ipv6_opt_hdr *old,
1220 struct ipv6_opt_hdr *new,
1221 int newtype, char **p)
1222 {
1223 struct ipv6_opt_hdr *src;
1224
1225 src = (renewtype == newtype ? new : old);
1226 if (!src)
1227 return;
1228
1229 memcpy(*p, src, ipv6_optlen(src));
1230 *dest = (struct ipv6_opt_hdr *)*p;
1231 *p += CMSG_ALIGN(ipv6_optlen(*dest));
1232 }
1233
1234 /**
1235 * ipv6_renew_options - replace a specific ext hdr with a new one.
1236 *
1237 * @sk: sock from which to allocate memory
1238 * @opt: original options
1239 * @newtype: option type to replace in @opt
1240 * @newopt: new option of type @newtype to replace (user-mem)
1241 *
1242 * Returns a new set of options which is a copy of @opt with the
1243 * option type @newtype replaced with @newopt.
1244 *
1245 * @opt may be NULL, in which case a new set of options is returned
1246 * containing just @newopt.
1247 *
1248 * @newopt may be NULL, in which case the specified option type is
1249 * not copied into the new set of options.
1250 *
1251 * The new set of options is allocated from the socket option memory
1252 * buffer of @sk.
1253 */
1254 struct ipv6_txoptions *
ipv6_renew_options(struct sock * sk,struct ipv6_txoptions * opt,int newtype,struct ipv6_opt_hdr * newopt)1255 ipv6_renew_options(struct sock *sk, struct ipv6_txoptions *opt,
1256 int newtype, struct ipv6_opt_hdr *newopt)
1257 {
1258 int tot_len = 0;
1259 char *p;
1260 struct ipv6_txoptions *opt2;
1261
1262 if (opt) {
1263 if (newtype != IPV6_HOPOPTS && opt->hopopt)
1264 tot_len += CMSG_ALIGN(ipv6_optlen(opt->hopopt));
1265 if (newtype != IPV6_RTHDRDSTOPTS && opt->dst0opt)
1266 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst0opt));
1267 if (newtype != IPV6_RTHDR && opt->srcrt)
1268 tot_len += CMSG_ALIGN(ipv6_optlen(opt->srcrt));
1269 if (newtype != IPV6_DSTOPTS && opt->dst1opt)
1270 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst1opt));
1271 }
1272
1273 if (newopt)
1274 tot_len += CMSG_ALIGN(ipv6_optlen(newopt));
1275
1276 if (!tot_len)
1277 return NULL;
1278
1279 tot_len += sizeof(*opt2);
1280 opt2 = sock_kmalloc(sk, tot_len, GFP_ATOMIC);
1281 if (!opt2)
1282 return ERR_PTR(-ENOBUFS);
1283
1284 memset(opt2, 0, tot_len);
1285 refcount_set(&opt2->refcnt, 1);
1286 opt2->tot_len = tot_len;
1287 p = (char *)(opt2 + 1);
1288
1289 ipv6_renew_option(IPV6_HOPOPTS, &opt2->hopopt,
1290 (opt ? opt->hopopt : NULL),
1291 newopt, newtype, &p);
1292 ipv6_renew_option(IPV6_RTHDRDSTOPTS, &opt2->dst0opt,
1293 (opt ? opt->dst0opt : NULL),
1294 newopt, newtype, &p);
1295 ipv6_renew_option(IPV6_RTHDR,
1296 (struct ipv6_opt_hdr **)&opt2->srcrt,
1297 (opt ? (struct ipv6_opt_hdr *)opt->srcrt : NULL),
1298 newopt, newtype, &p);
1299 ipv6_renew_option(IPV6_DSTOPTS, &opt2->dst1opt,
1300 (opt ? opt->dst1opt : NULL),
1301 newopt, newtype, &p);
1302
1303 opt2->opt_nflen = (opt2->hopopt ? ipv6_optlen(opt2->hopopt) : 0) +
1304 (opt2->dst0opt ? ipv6_optlen(opt2->dst0opt) : 0) +
1305 (opt2->srcrt ? ipv6_optlen(opt2->srcrt) : 0);
1306 opt2->opt_flen = (opt2->dst1opt ? ipv6_optlen(opt2->dst1opt) : 0);
1307
1308 return opt2;
1309 }
1310
__ipv6_fixup_options(struct ipv6_txoptions * opt_space,struct ipv6_txoptions * opt)1311 struct ipv6_txoptions *__ipv6_fixup_options(struct ipv6_txoptions *opt_space,
1312 struct ipv6_txoptions *opt)
1313 {
1314 /*
1315 * ignore the dest before srcrt unless srcrt is being included.
1316 * --yoshfuji
1317 */
1318 if (opt->dst0opt && !opt->srcrt) {
1319 if (opt_space != opt) {
1320 memcpy(opt_space, opt, sizeof(*opt_space));
1321 opt = opt_space;
1322 }
1323 opt->opt_nflen -= ipv6_optlen(opt->dst0opt);
1324 opt->dst0opt = NULL;
1325 }
1326
1327 return opt;
1328 }
1329 EXPORT_SYMBOL_GPL(__ipv6_fixup_options);
1330
1331 /**
1332 * fl6_update_dst - update flowi destination address with info given
1333 * by srcrt option, if any.
1334 *
1335 * @fl6: flowi6 for which daddr is to be updated
1336 * @opt: struct ipv6_txoptions in which to look for srcrt opt
1337 * @orig: copy of original daddr address if modified
1338 *
1339 * Returns NULL if no txoptions or no srcrt, otherwise returns orig
1340 * and initial value of fl6->daddr set in orig
1341 */
fl6_update_dst(struct flowi6 * fl6,const struct ipv6_txoptions * opt,struct in6_addr * orig)1342 struct in6_addr *fl6_update_dst(struct flowi6 *fl6,
1343 const struct ipv6_txoptions *opt,
1344 struct in6_addr *orig)
1345 {
1346 if (!opt || !opt->srcrt)
1347 return NULL;
1348
1349 *orig = fl6->daddr;
1350
1351 switch (opt->srcrt->type) {
1352 case IPV6_SRCRT_TYPE_0:
1353 case IPV6_SRCRT_STRICT:
1354 case IPV6_SRCRT_TYPE_2:
1355 fl6->daddr = *((struct rt0_hdr *)opt->srcrt)->addr;
1356 break;
1357 case IPV6_SRCRT_TYPE_4:
1358 {
1359 struct ipv6_sr_hdr *srh = (struct ipv6_sr_hdr *)opt->srcrt;
1360
1361 fl6->daddr = srh->segments[srh->segments_left];
1362 break;
1363 }
1364 default:
1365 return NULL;
1366 }
1367
1368 return orig;
1369 }
1370 EXPORT_SYMBOL_GPL(fl6_update_dst);
1371
