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
53 #include <linux/uaccess.h>
54
55 /*
56 * Parsing tlv encoded headers.
57 *
58 * Parsing function "func" returns true, if parsing succeed
59 * and false, if it failed.
60 * It MUST NOT touch skb->h.
61 */
62
63 struct tlvtype_proc {
64 int type;
65 bool (*func)(struct sk_buff *skb, int offset);
66 };
67
68 /*********************
69 Generic functions
70 *********************/
71
72 /* An unknown option is detected, decide what to do */
73
ip6_tlvopt_unknown(struct sk_buff * skb,int optoff,bool disallow_unknowns)74 static bool ip6_tlvopt_unknown(struct sk_buff *skb, int optoff,
75 bool disallow_unknowns)
76 {
77 if (disallow_unknowns) {
78 /* If unknown TLVs are disallowed by configuration
79 * then always silently drop packet. Note this also
80 * means no ICMP parameter problem is sent which
81 * could be a good property to mitigate a reflection DOS
82 * attack.
83 */
84
85 goto drop;
86 }
87
88 switch ((skb_network_header(skb)[optoff] & 0xC0) >> 6) {
89 case 0: /* ignore */
90 return true;
91
92 case 1: /* drop packet */
93 break;
94
95 case 3: /* Send ICMP if not a multicast address and drop packet */
96 /* Actually, it is redundant check. icmp_send
97 will recheck in any case.
98 */
99 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr))
100 break;
101 fallthrough;
102 case 2: /* send ICMP PARM PROB regardless and drop packet */
103 icmpv6_param_prob(skb, ICMPV6_UNK_OPTION, optoff);
104 return false;
105 }
106
107 drop:
108 kfree_skb(skb);
109 return false;
110 }
111
112 /* Parse tlv encoded option header (hop-by-hop or destination) */
113
ip6_parse_tlv(const struct tlvtype_proc * procs,struct sk_buff * skb,int max_count)114 static bool ip6_parse_tlv(const struct tlvtype_proc *procs,
115 struct sk_buff *skb,
116 int max_count)
117 {
118 int len = (skb_transport_header(skb)[1] + 1) << 3;
119 const unsigned char *nh = skb_network_header(skb);
120 int off = skb_network_header_len(skb);
121 const struct tlvtype_proc *curr;
122 bool disallow_unknowns = false;
123 int tlv_count = 0;
124 int padlen = 0;
125
126 if (unlikely(max_count < 0)) {
127 disallow_unknowns = true;
128 max_count = -max_count;
129 }
130
131 if (skb_transport_offset(skb) + len > skb_headlen(skb))
132 goto bad;
133
134 off += 2;
135 len -= 2;
136
137 while (len > 0) {
138 int optlen, i;
139
140 if (nh[off] == IPV6_TLV_PAD1) {
141 padlen++;
142 if (padlen > 7)
143 goto bad;
144 off++;
145 len--;
146 continue;
147 }
148 if (len < 2)
149 goto bad;
150 optlen = nh[off + 1] + 2;
151 if (optlen > len)
152 goto bad;
153
154 if (nh[off] == IPV6_TLV_PADN) {
155 /* RFC 2460 states that the purpose of PadN is
156 * to align the containing header to multiples
157 * of 8. 7 is therefore the highest valid value.
158 * See also RFC 4942, Section 2.1.9.5.
159 */
160 padlen += optlen;
161 if (padlen > 7)
162 goto bad;
163 /* RFC 4942 recommends receiving hosts to
164 * actively check PadN payload to contain
165 * only zeroes.
166 */
167 for (i = 2; i < optlen; i++) {
168 if (nh[off + i] != 0)
169 goto bad;
170 }
171 } else {
172 tlv_count++;
173 if (tlv_count > max_count)
174 goto bad;
175
176 for (curr = procs; curr->type >= 0; curr++) {
177 if (curr->type == nh[off]) {
178 /* type specific length/alignment
179 checks will be performed in the
180 func(). */
181 if (curr->func(skb, off) == false)
182 return false;
183 break;
184 }
185 }
186 if (curr->type < 0 &&
187 !ip6_tlvopt_unknown(skb, off, disallow_unknowns))
188 return false;
189
190 padlen = 0;
191 }
192 off += optlen;
193 len -= optlen;
194 }
195
196 if (len == 0)
197 return true;
198 bad:
199 kfree_skb(skb);
200 return false;
201 }
202
203 /*****************************
204 Destination options header.
205 *****************************/
206
207 #if IS_ENABLED(CONFIG_IPV6_MIP6)
ipv6_dest_hao(struct sk_buff * skb,int optoff)208 static bool ipv6_dest_hao(struct sk_buff *skb, int optoff)
209 {
210 struct ipv6_destopt_hao *hao;
211 struct inet6_skb_parm *opt = IP6CB(skb);
212 struct ipv6hdr *ipv6h = ipv6_hdr(skb);
213 int ret;
214
215 if (opt->dsthao) {
216 net_dbg_ratelimited("hao duplicated\n");
217 goto discard;
218 }
219 opt->dsthao = opt->dst1;
220 opt->dst1 = 0;
221
222 hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) + optoff);
223
224 if (hao->length != 16) {
225 net_dbg_ratelimited("hao invalid option length = %d\n",
226 hao->length);
227 goto discard;
228 }
229
230 if (!(ipv6_addr_type(&hao->addr) & IPV6_ADDR_UNICAST)) {
231 net_dbg_ratelimited("hao is not an unicast addr: %pI6\n",
232 &hao->addr);
233 goto discard;
234 }
235
236 ret = xfrm6_input_addr(skb, (xfrm_address_t *)&ipv6h->daddr,
237 (xfrm_address_t *)&hao->addr, IPPROTO_DSTOPTS);
238 if (unlikely(ret < 0))
239 goto discard;
240
241 if (skb_cloned(skb)) {
242 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
243 goto discard;
244
245 /* update all variable using below by copied skbuff */
246 hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) +
247 optoff);
248 ipv6h = ipv6_hdr(skb);
249 }
250
251 if (skb->ip_summed == CHECKSUM_COMPLETE)
252 skb->ip_summed = CHECKSUM_NONE;
253
254 swap(ipv6h->saddr, hao->addr);
255
256 if (skb->tstamp == 0)
257 __net_timestamp(skb);
258
259 return true;
260
261 discard:
262 kfree_skb(skb);
263 return false;
264 }
265 #endif
266
267 static const struct tlvtype_proc tlvprocdestopt_lst[] = {
268 #if IS_ENABLED(CONFIG_IPV6_MIP6)
269 {
270 .type = IPV6_TLV_HAO,
271 .func = ipv6_dest_hao,
272 },
273 #endif
274 {-1, NULL}
275 };
276
ipv6_destopt_rcv(struct sk_buff * skb)277 static int ipv6_destopt_rcv(struct sk_buff *skb)
278 {
279 struct inet6_dev *idev = __in6_dev_get(skb->dev);
280 struct inet6_skb_parm *opt = IP6CB(skb);
281 #if IS_ENABLED(CONFIG_IPV6_MIP6)
282 __u16 dstbuf;
283 #endif
284 struct dst_entry *dst = skb_dst(skb);
285 struct net *net = dev_net(skb->dev);
286 int extlen;
287
288 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
289 !pskb_may_pull(skb, (skb_transport_offset(skb) +
290 ((skb_transport_header(skb)[1] + 1) << 3)))) {
291 __IP6_INC_STATS(dev_net(dst->dev), idev,
292 IPSTATS_MIB_INHDRERRORS);
293 fail_and_free:
294 kfree_skb(skb);
295 return -1;
296 }
297
298 extlen = (skb_transport_header(skb)[1] + 1) << 3;
299 if (extlen > net->ipv6.sysctl.max_dst_opts_len)
300 goto fail_and_free;
301
302 opt->lastopt = opt->dst1 = skb_network_header_len(skb);
303 #if IS_ENABLED(CONFIG_IPV6_MIP6)
304 dstbuf = opt->dst1;
305 #endif
306
307 if (ip6_parse_tlv(tlvprocdestopt_lst, skb,
308 net->ipv6.sysctl.max_dst_opts_cnt)) {
309 skb->transport_header += extlen;
310 opt = IP6CB(skb);
311 #if IS_ENABLED(CONFIG_IPV6_MIP6)
312 opt->nhoff = dstbuf;
313 #else
314 opt->nhoff = opt->dst1;
315 #endif
316 return 1;
317 }
318
319 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
320 return -1;
321 }
322
seg6_update_csum(struct sk_buff * skb)323 static void seg6_update_csum(struct sk_buff *skb)
324 {
325 struct ipv6_sr_hdr *hdr;
326 struct in6_addr *addr;
327 __be32 from, to;
328
329 /* srh is at transport offset and seg_left is already decremented
330 * but daddr is not yet updated with next segment
331 */
332
333 hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb);
334 addr = hdr->segments + hdr->segments_left;
335
336 hdr->segments_left++;
337 from = *(__be32 *)hdr;
338
339 hdr->segments_left--;
340 to = *(__be32 *)hdr;
341
342 /* update skb csum with diff resulting from seg_left decrement */
343
344 update_csum_diff4(skb, from, to);
345
346 /* compute csum diff between current and next segment and update */
347
348 update_csum_diff16(skb, (__be32 *)(&ipv6_hdr(skb)->daddr),
349 (__be32 *)addr);
350 }
351
ipv6_srh_rcv(struct sk_buff * skb)352 static int ipv6_srh_rcv(struct sk_buff *skb)
353 {
354 struct inet6_skb_parm *opt = IP6CB(skb);
355 struct net *net = dev_net(skb->dev);
356 struct ipv6_sr_hdr *hdr;
357 struct inet6_dev *idev;
358 struct in6_addr *addr;
359 int accept_seg6;
360
361 hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb);
362
363 idev = __in6_dev_get(skb->dev);
364
365 accept_seg6 = net->ipv6.devconf_all->seg6_enabled;
366 if (accept_seg6 > idev->cnf.seg6_enabled)
367 accept_seg6 = idev->cnf.seg6_enabled;
368
369 if (!accept_seg6) {
370 kfree_skb(skb);
371 return -1;
372 }
373
374 #ifdef CONFIG_IPV6_SEG6_HMAC
375 if (!seg6_hmac_validate_skb(skb)) {
376 kfree_skb(skb);
377 return -1;
378 }
379 #endif
380
381 looped_back:
382 if (hdr->segments_left == 0) {
383 if (hdr->nexthdr == NEXTHDR_IPV6) {
384 int offset = (hdr->hdrlen + 1) << 3;
385
386 skb_postpull_rcsum(skb, skb_network_header(skb),
387 skb_network_header_len(skb));
388
389 if (!pskb_pull(skb, offset)) {
390 kfree_skb(skb);
391 return -1;
392 }
393 skb_postpull_rcsum(skb, skb_transport_header(skb),
394 offset);
395
396 skb_reset_network_header(skb);
397 skb_reset_transport_header(skb);
398 skb->encapsulation = 0;
399
400 __skb_tunnel_rx(skb, skb->dev, net);
401
402 netif_rx(skb);
403 return -1;
404 }
405
406 opt->srcrt = skb_network_header_len(skb);
407 opt->lastopt = opt->srcrt;
408 skb->transport_header += (hdr->hdrlen + 1) << 3;
409 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb);
410
411 return 1;
412 }
413
414 if (hdr->segments_left >= (hdr->hdrlen >> 1)) {
415 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
416 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
417 ((&hdr->segments_left) -
418 skb_network_header(skb)));
419 return -1;
420 }
421
422 if (skb_cloned(skb)) {
423 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) {
424 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
425 IPSTATS_MIB_OUTDISCARDS);
426 kfree_skb(skb);
427 return -1;
428 }
429 }
430
431 hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb);
432
433 hdr->segments_left--;
434 addr = hdr->segments + hdr->segments_left;
435
436 skb_push(skb, sizeof(struct ipv6hdr));
437
438 if (skb->ip_summed == CHECKSUM_COMPLETE)
439 seg6_update_csum(skb);
440
441 ipv6_hdr(skb)->daddr = *addr;
442
443 skb_dst_drop(skb);
444
445 ip6_route_input(skb);
446
447 if (skb_dst(skb)->error) {
448 dst_input(skb);
449 return -1;
450 }
451
452 if (skb_dst(skb)->dev->flags & IFF_LOOPBACK) {
453 if (ipv6_hdr(skb)->hop_limit <= 1) {
454 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
455 icmpv6_send(skb, ICMPV6_TIME_EXCEED,
456 ICMPV6_EXC_HOPLIMIT, 0);
457 kfree_skb(skb);
458 return -1;
459 }
460 ipv6_hdr(skb)->hop_limit--;
461
462 skb_pull(skb, sizeof(struct ipv6hdr));
463 goto looped_back;
464 }
465
466 dst_input(skb);
467
468 return -1;
469 }
470
ipv6_rpl_srh_rcv(struct sk_buff * skb)471 static int ipv6_rpl_srh_rcv(struct sk_buff *skb)
472 {
473 struct ipv6_rpl_sr_hdr *hdr, *ohdr, *chdr;
474 struct inet6_skb_parm *opt = IP6CB(skb);
475 struct net *net = dev_net(skb->dev);
476 struct inet6_dev *idev;
477 struct ipv6hdr *oldhdr;
478 struct in6_addr addr;
479 unsigned char *buf;
480 int accept_rpl_seg;
481 int i, err;
482 u64 n = 0;
483 u32 r;
484
485 idev = __in6_dev_get(skb->dev);
486
487 accept_rpl_seg = net->ipv6.devconf_all->rpl_seg_enabled;
488 if (accept_rpl_seg > idev->cnf.rpl_seg_enabled)
489 accept_rpl_seg = idev->cnf.rpl_seg_enabled;
490
491 if (!accept_rpl_seg) {
492 kfree_skb(skb);
493 return -1;
494 }
495
496 looped_back:
497 hdr = (struct ipv6_rpl_sr_hdr *)skb_transport_header(skb);
498
499 if (hdr->segments_left == 0) {
500 if (hdr->nexthdr == NEXTHDR_IPV6) {
501 int offset = (hdr->hdrlen + 1) << 3;
502
503 skb_postpull_rcsum(skb, skb_network_header(skb),
504 skb_network_header_len(skb));
505
506 if (!pskb_pull(skb, offset)) {
507 kfree_skb(skb);
508 return -1;
509 }
510 skb_postpull_rcsum(skb, skb_transport_header(skb),
511 offset);
512
513 skb_reset_network_header(skb);
514 skb_reset_transport_header(skb);
515 skb->encapsulation = 0;
516
517 __skb_tunnel_rx(skb, skb->dev, net);
518
519 netif_rx(skb);
520 return -1;
521 }
522
523 opt->srcrt = skb_network_header_len(skb);
524 opt->lastopt = opt->srcrt;
525 skb->transport_header += (hdr->hdrlen + 1) << 3;
526 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb);
527
528 return 1;
529 }
530
531 if (!pskb_may_pull(skb, sizeof(*hdr))) {
532 kfree_skb(skb);
533 return -1;
534 }
535
536 n = (hdr->hdrlen << 3) - hdr->pad - (16 - hdr->cmpre);
537 r = do_div(n, (16 - hdr->cmpri));
538 /* checks if calculation was without remainder and n fits into
539 * unsigned char which is segments_left field. Should not be
540 * higher than that.
541 */
542 if (r || (n + 1) > 255) {
543 kfree_skb(skb);
544 return -1;
545 }
546
547 if (hdr->segments_left > n + 1) {
548 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
549 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
550 ((&hdr->segments_left) -
551 skb_network_header(skb)));
552 return -1;
553 }
554
555 if (!pskb_may_pull(skb, ipv6_rpl_srh_size(n, hdr->cmpri,
556 hdr->cmpre))) {
557 kfree_skb(skb);
558 return -1;
559 }
560
561 hdr->segments_left--;
562 i = n - hdr->segments_left;
563
564 buf = kcalloc(struct_size(hdr, segments.addr, n + 2), 2, GFP_ATOMIC);
565 if (unlikely(!buf)) {
566 kfree_skb(skb);
567 return -1;
568 }
569
570 ohdr = (struct ipv6_rpl_sr_hdr *)buf;
571 ipv6_rpl_srh_decompress(ohdr, hdr, &ipv6_hdr(skb)->daddr, n);
572 chdr = (struct ipv6_rpl_sr_hdr *)(buf + ((ohdr->hdrlen + 1) << 3));
573
574 if ((ipv6_addr_type(&ipv6_hdr(skb)->daddr) & IPV6_ADDR_MULTICAST) ||
575 (ipv6_addr_type(&ohdr->rpl_segaddr[i]) & IPV6_ADDR_MULTICAST)) {
576 kfree_skb(skb);
577 kfree(buf);
578 return -1;
579 }
580
581 err = ipv6_chk_rpl_srh_loop(net, ohdr->rpl_segaddr, n + 1);
582 if (err) {
583 icmpv6_send(skb, ICMPV6_PARAMPROB, 0, 0);
584 kfree_skb(skb);
585 kfree(buf);
586 return -1;
587 }
588
589 addr = ipv6_hdr(skb)->daddr;
590 ipv6_hdr(skb)->daddr = ohdr->rpl_segaddr[i];
591 ohdr->rpl_segaddr[i] = addr;
592
593 ipv6_rpl_srh_compress(chdr, ohdr, &ipv6_hdr(skb)->daddr, n);
594
595 oldhdr = ipv6_hdr(skb);
596
597 skb_pull(skb, ((hdr->hdrlen + 1) << 3));
598 skb_postpull_rcsum(skb, oldhdr,
599 sizeof(struct ipv6hdr) + ((hdr->hdrlen + 1) << 3));
600 if (unlikely(!hdr->segments_left)) {
601 if (pskb_expand_head(skb, sizeof(struct ipv6hdr) + ((chdr->hdrlen + 1) << 3), 0,
602 GFP_ATOMIC)) {
603 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_OUTDISCARDS);
604 kfree_skb(skb);
605 kfree(buf);
606 return -1;
607 }
608
609 oldhdr = ipv6_hdr(skb);
610 }
611 skb_push(skb, ((chdr->hdrlen + 1) << 3) + sizeof(struct ipv6hdr));
612 skb_reset_network_header(skb);
613 skb_mac_header_rebuild(skb);
614 skb_set_transport_header(skb, sizeof(struct ipv6hdr));
615
616 memmove(ipv6_hdr(skb), oldhdr, sizeof(struct ipv6hdr));
617 memcpy(skb_transport_header(skb), chdr, (chdr->hdrlen + 1) << 3);
618
619 ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
620 skb_postpush_rcsum(skb, ipv6_hdr(skb),
621 sizeof(struct ipv6hdr) + ((chdr->hdrlen + 1) << 3));
622
623 kfree(buf);
624
625 skb_dst_drop(skb);
626
627 ip6_route_input(skb);
628
629 if (skb_dst(skb)->error) {
630 dst_input(skb);
631 return -1;
632 }
633
634 if (skb_dst(skb)->dev->flags & IFF_LOOPBACK) {
635 if (ipv6_hdr(skb)->hop_limit <= 1) {
636 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
637 icmpv6_send(skb, ICMPV6_TIME_EXCEED,
638 ICMPV6_EXC_HOPLIMIT, 0);
639 kfree_skb(skb);
640 return -1;
641 }
642 ipv6_hdr(skb)->hop_limit--;
643
644 skb_pull(skb, sizeof(struct ipv6hdr));
645 goto looped_back;
646 }
647
648 dst_input(skb);
649
650 return -1;
651 }
652
653 /********************************
654 Routing header.
655 ********************************/
656
657 /* called with rcu_read_lock() */
ipv6_rthdr_rcv(struct sk_buff * skb)658 static int ipv6_rthdr_rcv(struct sk_buff *skb)
659 {
660 struct inet6_dev *idev = __in6_dev_get(skb->dev);
661 struct inet6_skb_parm *opt = IP6CB(skb);
662 struct in6_addr *addr = NULL;
663 struct in6_addr daddr;
664 int n, i;
665 struct ipv6_rt_hdr *hdr;
666 struct rt0_hdr *rthdr;
667 struct net *net = dev_net(skb->dev);
668 int accept_source_route = net->ipv6.devconf_all->accept_source_route;
669
670 idev = __in6_dev_get(skb->dev);
671 if (idev && accept_source_route > idev->cnf.accept_source_route)
672 accept_source_route = idev->cnf.accept_source_route;
673
674 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
675 !pskb_may_pull(skb, (skb_transport_offset(skb) +
676 ((skb_transport_header(skb)[1] + 1) << 3)))) {
677 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
678 kfree_skb(skb);
679 return -1;
680 }
681
682 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb);
683
684 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) ||
685 skb->pkt_type != PACKET_HOST) {
686 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
687 kfree_skb(skb);
688 return -1;
689 }
690
691 switch (hdr->type) {
692 case IPV6_SRCRT_TYPE_4:
693 /* segment routing */
694 return ipv6_srh_rcv(skb);
695 case IPV6_SRCRT_TYPE_3:
696 /* rpl segment routing */
697 return ipv6_rpl_srh_rcv(skb);
698 default:
699 break;
700 }
701
702 looped_back:
703 if (hdr->segments_left == 0) {
704 switch (hdr->type) {
705 #if IS_ENABLED(CONFIG_IPV6_MIP6)
706 case IPV6_SRCRT_TYPE_2:
707 /* Silently discard type 2 header unless it was
708 * processed by own
709 */
710 if (!addr) {
711 __IP6_INC_STATS(net, idev,
712 IPSTATS_MIB_INADDRERRORS);
713 kfree_skb(skb);
714 return -1;
715 }
716 break;
717 #endif
718 default:
719 break;
720 }
721
722 opt->lastopt = opt->srcrt = skb_network_header_len(skb);
723 skb->transport_header += (hdr->hdrlen + 1) << 3;
724 opt->dst0 = opt->dst1;
725 opt->dst1 = 0;
726 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb);
727 return 1;
728 }
729
730 switch (hdr->type) {
731 #if IS_ENABLED(CONFIG_IPV6_MIP6)
732 case IPV6_SRCRT_TYPE_2:
733 if (accept_source_route < 0)
734 goto unknown_rh;
735 /* Silently discard invalid RTH type 2 */
736 if (hdr->hdrlen != 2 || hdr->segments_left != 1) {
737 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
738 kfree_skb(skb);
739 return -1;
740 }
741 break;
742 #endif
743 default:
744 goto unknown_rh;
745 }
746
747 /*
748 * This is the routing header forwarding algorithm from
749 * RFC 2460, page 16.
750 */
751
752 n = hdr->hdrlen >> 1;
753
754 if (hdr->segments_left > n) {
755 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
756 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
757 ((&hdr->segments_left) -
758 skb_network_header(skb)));
759 return -1;
760 }
761
762 /* We are about to mangle packet header. Be careful!
763 Do not damage packets queued somewhere.
764 */
765 if (skb_cloned(skb)) {
766 /* the copy is a forwarded packet */
767 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) {
768 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
769 IPSTATS_MIB_OUTDISCARDS);
770 kfree_skb(skb);
771 return -1;
772 }
773 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb);
774 }
775
776 if (skb->ip_summed == CHECKSUM_COMPLETE)
777 skb->ip_summed = CHECKSUM_NONE;
778
779 i = n - --hdr->segments_left;
780
781 rthdr = (struct rt0_hdr *) hdr;
782 addr = rthdr->addr;
783 addr += i - 1;
784
785 switch (hdr->type) {
786 #if IS_ENABLED(CONFIG_IPV6_MIP6)
787 case IPV6_SRCRT_TYPE_2:
788 if (xfrm6_input_addr(skb, (xfrm_address_t *)addr,
789 (xfrm_address_t *)&ipv6_hdr(skb)->saddr,
790 IPPROTO_ROUTING) < 0) {
791 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
792 kfree_skb(skb);
793 return -1;
794 }
795 if (!ipv6_chk_home_addr(dev_net(skb_dst(skb)->dev), addr)) {
796 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
797 kfree_skb(skb);
798 return -1;
799 }
800 break;
801 #endif
802 default:
803 break;
804 }
805
806 if (ipv6_addr_is_multicast(addr)) {
807 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
808 kfree_skb(skb);
809 return -1;
810 }
811
812 daddr = *addr;
813 *addr = ipv6_hdr(skb)->daddr;
814 ipv6_hdr(skb)->daddr = daddr;
815
816 skb_dst_drop(skb);
817 ip6_route_input(skb);
818 if (skb_dst(skb)->error) {
819 skb_push(skb, skb->data - skb_network_header(skb));
820 dst_input(skb);
821 return -1;
822 }
823
824 if (skb_dst(skb)->dev->flags&IFF_LOOPBACK) {
825 if (ipv6_hdr(skb)->hop_limit <= 1) {
826 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
827 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
828 0);
829 kfree_skb(skb);
830 return -1;
831 }
832 ipv6_hdr(skb)->hop_limit--;
833 goto looped_back;
834 }
835
836 skb_push(skb, skb->data - skb_network_header(skb));
837 dst_input(skb);
838 return -1;
839
840 unknown_rh:
841 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
842 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
843 (&hdr->type) - skb_network_header(skb));
844 return -1;
845 }
846
847 static const struct inet6_protocol rthdr_protocol = {
848 .handler = ipv6_rthdr_rcv,
849 .flags = INET6_PROTO_NOPOLICY,
850 };
851
852 static const struct inet6_protocol destopt_protocol = {
853 .handler = ipv6_destopt_rcv,
854 .flags = INET6_PROTO_NOPOLICY,
855 };
856
857 static const struct inet6_protocol nodata_protocol = {
858 .handler = dst_discard,
859 .flags = INET6_PROTO_NOPOLICY,
860 };
861
ipv6_exthdrs_init(void)862 int __init ipv6_exthdrs_init(void)
863 {
864 int ret;
865
866 ret = inet6_add_protocol(&rthdr_protocol, IPPROTO_ROUTING);
867 if (ret)
868 goto out;
869
870 ret = inet6_add_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
871 if (ret)
872 goto out_rthdr;
873
874 ret = inet6_add_protocol(&nodata_protocol, IPPROTO_NONE);
875 if (ret)
876 goto out_destopt;
877
878 out:
879 return ret;
880 out_destopt:
881 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
882 out_rthdr:
883 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING);
884 goto out;
885 };
886
ipv6_exthdrs_exit(void)887 void ipv6_exthdrs_exit(void)
888 {
889 inet6_del_protocol(&nodata_protocol, IPPROTO_NONE);
890 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
891 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING);
892 }
893
894 /**********************************
895 Hop-by-hop options.
896 **********************************/
897
898 /*
899 * Note: we cannot rely on skb_dst(skb) before we assign it in ip6_route_input().
900 */
ipv6_skb_idev(struct sk_buff * skb)901 static inline struct inet6_dev *ipv6_skb_idev(struct sk_buff *skb)
902 {
903 return skb_dst(skb) ? ip6_dst_idev(skb_dst(skb)) : __in6_dev_get(skb->dev);
904 }
905
ipv6_skb_net(struct sk_buff * skb)906 static inline struct net *ipv6_skb_net(struct sk_buff *skb)
907 {
908 return skb_dst(skb) ? dev_net(skb_dst(skb)->dev) : dev_net(skb->dev);
909 }
910
911 /* Router Alert as of RFC 2711 */
912
ipv6_hop_ra(struct sk_buff * skb,int optoff)913 static bool ipv6_hop_ra(struct sk_buff *skb, int optoff)
914 {
915 const unsigned char *nh = skb_network_header(skb);
916
917 if (nh[optoff + 1] == 2) {
918 IP6CB(skb)->flags |= IP6SKB_ROUTERALERT;
919 memcpy(&IP6CB(skb)->ra, nh + optoff + 2, sizeof(IP6CB(skb)->ra));
920 return true;
921 }
922 net_dbg_ratelimited("ipv6_hop_ra: wrong RA length %d\n",
923 nh[optoff + 1]);
924 kfree_skb(skb);
925 return false;
926 }
927
928 /* Jumbo payload */
929
ipv6_hop_jumbo(struct sk_buff * skb,int optoff)930 static bool ipv6_hop_jumbo(struct sk_buff *skb, int optoff)
931 {
932 const unsigned char *nh = skb_network_header(skb);
933 struct inet6_dev *idev = __in6_dev_get_safely(skb->dev);
934 struct net *net = ipv6_skb_net(skb);
935 u32 pkt_len;
936
937 if (nh[optoff + 1] != 4 || (optoff & 3) != 2) {
938 net_dbg_ratelimited("ipv6_hop_jumbo: wrong jumbo opt length/alignment %d\n",
939 nh[optoff+1]);
940 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
941 goto drop;
942 }
943
944 pkt_len = ntohl(*(__be32 *)(nh + optoff + 2));
945 if (pkt_len <= IPV6_MAXPLEN) {
946 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
947 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff+2);
948 return false;
949 }
950 if (ipv6_hdr(skb)->payload_len) {
951 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
952 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff);
953 return false;
954 }
955
956 if (pkt_len > skb->len - sizeof(struct ipv6hdr)) {
957 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INTRUNCATEDPKTS);
958 goto drop;
959 }
960
961 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr)))
962 goto drop;
963
964 IP6CB(skb)->flags |= IP6SKB_JUMBOGRAM;
965 return true;
966
967 drop:
968 kfree_skb(skb);
969 return false;
970 }
971
972 /* CALIPSO RFC 5570 */
973
ipv6_hop_calipso(struct sk_buff * skb,int optoff)974 static bool ipv6_hop_calipso(struct sk_buff *skb, int optoff)
975 {
976 const unsigned char *nh = skb_network_header(skb);
977
978 if (nh[optoff + 1] < 8)
979 goto drop;
980
981 if (nh[optoff + 6] * 4 + 8 > nh[optoff + 1])
982 goto drop;
983
984 if (!calipso_validate(skb, nh + optoff))
985 goto drop;
986
987 return true;
988
989 drop:
990 kfree_skb(skb);
991 return false;
992 }
993
994 static const struct tlvtype_proc tlvprochopopt_lst[] = {
995 {
996 .type = IPV6_TLV_ROUTERALERT,
997 .func = ipv6_hop_ra,
998 },
999 {
1000 .type = IPV6_TLV_JUMBO,
1001 .func = ipv6_hop_jumbo,
1002 },
1003 {
1004 .type = IPV6_TLV_CALIPSO,
1005 .func = ipv6_hop_calipso,
1006 },
1007 { -1, }
1008 };
1009
ipv6_parse_hopopts(struct sk_buff * skb)1010 int ipv6_parse_hopopts(struct sk_buff *skb)
1011 {
1012 struct inet6_skb_parm *opt = IP6CB(skb);
1013 struct net *net = dev_net(skb->dev);
1014 int extlen;
1015
1016 /*
1017 * skb_network_header(skb) is equal to skb->data, and
1018 * skb_network_header_len(skb) is always equal to
1019 * sizeof(struct ipv6hdr) by definition of
1020 * hop-by-hop options.
1021 */
1022 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + 8) ||
1023 !pskb_may_pull(skb, (sizeof(struct ipv6hdr) +
1024 ((skb_transport_header(skb)[1] + 1) << 3)))) {
1025 fail_and_free:
1026 kfree_skb(skb);
1027 return -1;
1028 }
1029
1030 extlen = (skb_transport_header(skb)[1] + 1) << 3;
1031 if (extlen > net->ipv6.sysctl.max_hbh_opts_len)
1032 goto fail_and_free;
1033
1034 opt->flags |= IP6SKB_HOPBYHOP;
1035 if (ip6_parse_tlv(tlvprochopopt_lst, skb,
1036 net->ipv6.sysctl.max_hbh_opts_cnt)) {
1037 skb->transport_header += extlen;
1038 opt = IP6CB(skb);
1039 opt->nhoff = sizeof(struct ipv6hdr);
1040 return 1;
1041 }
1042 return -1;
1043 }
1044
1045 /*
1046 * Creating outbound headers.
1047 *
1048 * "build" functions work when skb is filled from head to tail (datagram)
1049 * "push" functions work when headers are added from tail to head (tcp)
1050 *
1051 * In both cases we assume, that caller reserved enough room
1052 * for headers.
1053 */
1054
ipv6_push_rthdr0(struct sk_buff * skb,u8 * proto,struct ipv6_rt_hdr * opt,struct in6_addr ** addr_p,struct in6_addr * saddr)1055 static void ipv6_push_rthdr0(struct sk_buff *skb, u8 *proto,
1056 struct ipv6_rt_hdr *opt,
1057 struct in6_addr **addr_p, struct in6_addr *saddr)
1058 {
1059 struct rt0_hdr *phdr, *ihdr;
1060 int hops;
1061
1062 ihdr = (struct rt0_hdr *) opt;
1063
1064 phdr = skb_push(skb, (ihdr->rt_hdr.hdrlen + 1) << 3);
1065 memcpy(phdr, ihdr, sizeof(struct rt0_hdr));
1066
1067 hops = ihdr->rt_hdr.hdrlen >> 1;
1068
1069 if (hops > 1)
1070 memcpy(phdr->addr, ihdr->addr + 1,
1071 (hops - 1) * sizeof(struct in6_addr));
1072
1073 phdr->addr[hops - 1] = **addr_p;
1074 *addr_p = ihdr->addr;
1075
1076 phdr->rt_hdr.nexthdr = *proto;
1077 *proto = NEXTHDR_ROUTING;
1078 }
1079
ipv6_push_rthdr4(struct sk_buff * skb,u8 * proto,struct ipv6_rt_hdr * opt,struct in6_addr ** addr_p,struct in6_addr * saddr)1080 static void ipv6_push_rthdr4(struct sk_buff *skb, u8 *proto,
1081 struct ipv6_rt_hdr *opt,
1082 struct in6_addr **addr_p, struct in6_addr *saddr)
1083 {
1084 struct ipv6_sr_hdr *sr_phdr, *sr_ihdr;
1085 int plen, hops;
1086
1087 sr_ihdr = (struct ipv6_sr_hdr *)opt;
1088 plen = (sr_ihdr->hdrlen + 1) << 3;
1089
1090 sr_phdr = skb_push(skb, plen);
1091 memcpy(sr_phdr, sr_ihdr, sizeof(struct ipv6_sr_hdr));
1092
1093 hops = sr_ihdr->first_segment + 1;
1094 memcpy(sr_phdr->segments + 1, sr_ihdr->segments + 1,
1095 (hops - 1) * sizeof(struct in6_addr));
1096
1097 sr_phdr->segments[0] = **addr_p;
1098 *addr_p = &sr_ihdr->segments[sr_ihdr->segments_left];
1099
1100 if (sr_ihdr->hdrlen > hops * 2) {
1101 int tlvs_offset, tlvs_length;
1102
1103 tlvs_offset = (1 + hops * 2) << 3;
1104 tlvs_length = (sr_ihdr->hdrlen - hops * 2) << 3;
1105 memcpy((char *)sr_phdr + tlvs_offset,
1106 (char *)sr_ihdr + tlvs_offset, tlvs_length);
1107 }
1108
1109 #ifdef CONFIG_IPV6_SEG6_HMAC
1110 if (sr_has_hmac(sr_phdr)) {
1111 struct net *net = NULL;
1112
1113 if (skb->dev)
1114 net = dev_net(skb->dev);
1115 else if (skb->sk)
1116 net = sock_net(skb->sk);
1117
1118 WARN_ON(!net);
1119
1120 if (net)
1121 seg6_push_hmac(net, saddr, sr_phdr);
1122 }
1123 #endif
1124
1125 sr_phdr->nexthdr = *proto;
1126 *proto = NEXTHDR_ROUTING;
1127 }
1128
ipv6_push_rthdr(struct sk_buff * skb,u8 * proto,struct ipv6_rt_hdr * opt,struct in6_addr ** addr_p,struct in6_addr * saddr)1129 static void ipv6_push_rthdr(struct sk_buff *skb, u8 *proto,
1130 struct ipv6_rt_hdr *opt,
1131 struct in6_addr **addr_p, struct in6_addr *saddr)
1132 {
1133 switch (opt->type) {
1134 case IPV6_SRCRT_TYPE_0:
1135 case IPV6_SRCRT_STRICT:
1136 case IPV6_SRCRT_TYPE_2:
1137 ipv6_push_rthdr0(skb, proto, opt, addr_p, saddr);
1138 break;
1139 case IPV6_SRCRT_TYPE_4:
1140 ipv6_push_rthdr4(skb, proto, opt, addr_p, saddr);
1141 break;
1142 default:
1143 break;
1144 }
1145 }
1146
ipv6_push_exthdr(struct sk_buff * skb,u8 * proto,u8 type,struct ipv6_opt_hdr * opt)1147 static void ipv6_push_exthdr(struct sk_buff *skb, u8 *proto, u8 type, struct ipv6_opt_hdr *opt)
1148 {
1149 struct ipv6_opt_hdr *h = skb_push(skb, ipv6_optlen(opt));
1150
1151 memcpy(h, opt, ipv6_optlen(opt));
1152 h->nexthdr = *proto;
1153 *proto = type;
1154 }
1155
ipv6_push_nfrag_opts(struct sk_buff * skb,struct ipv6_txoptions * opt,u8 * proto,struct in6_addr ** daddr,struct in6_addr * saddr)1156 void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
1157 u8 *proto,
1158 struct in6_addr **daddr, struct in6_addr *saddr)
1159 {
1160 if (opt->srcrt) {
1161 ipv6_push_rthdr(skb, proto, opt->srcrt, daddr, saddr);
1162 /*
1163 * IPV6_RTHDRDSTOPTS is ignored
1164 * unless IPV6_RTHDR is set (RFC3542).
1165 */
1166 if (opt->dst0opt)
1167 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst0opt);
1168 }
1169 if (opt->hopopt)
1170 ipv6_push_exthdr(skb, proto, NEXTHDR_HOP, opt->hopopt);
1171 }
1172
ipv6_push_frag_opts(struct sk_buff * skb,struct ipv6_txoptions * opt,u8 * proto)1173 void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, u8 *proto)
1174 {
1175 if (opt->dst1opt)
1176 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst1opt);
1177 }
1178 EXPORT_SYMBOL(ipv6_push_frag_opts);
1179
1180 struct ipv6_txoptions *
ipv6_dup_options(struct sock * sk,struct ipv6_txoptions * opt)1181 ipv6_dup_options(struct sock *sk, struct ipv6_txoptions *opt)
1182 {
1183 struct ipv6_txoptions *opt2;
1184
1185 opt2 = sock_kmalloc(sk, opt->tot_len, GFP_ATOMIC);
1186 if (opt2) {
1187 long dif = (char *)opt2 - (char *)opt;
1188 memcpy(opt2, opt, opt->tot_len);
1189 if (opt2->hopopt)
1190 *((char **)&opt2->hopopt) += dif;
1191 if (opt2->dst0opt)
1192 *((char **)&opt2->dst0opt) += dif;
1193 if (opt2->dst1opt)
1194 *((char **)&opt2->dst1opt) += dif;
1195 if (opt2->srcrt)
1196 *((char **)&opt2->srcrt) += dif;
1197 refcount_set(&opt2->refcnt, 1);
1198 }
1199 return opt2;
1200 }
1201 EXPORT_SYMBOL_GPL(ipv6_dup_options);
1202
ipv6_renew_option(int renewtype,struct ipv6_opt_hdr ** dest,struct ipv6_opt_hdr * old,struct ipv6_opt_hdr * new,int newtype,char ** p)1203 static void ipv6_renew_option(int renewtype,
1204 struct ipv6_opt_hdr **dest,
1205 struct ipv6_opt_hdr *old,
1206 struct ipv6_opt_hdr *new,
1207 int newtype, char **p)
1208 {
1209 struct ipv6_opt_hdr *src;
1210
1211 src = (renewtype == newtype ? new : old);
1212 if (!src)
1213 return;
1214
1215 memcpy(*p, src, ipv6_optlen(src));
1216 *dest = (struct ipv6_opt_hdr *)*p;
1217 *p += CMSG_ALIGN(ipv6_optlen(*dest));
1218 }
1219
1220 /**
1221 * ipv6_renew_options - replace a specific ext hdr with a new one.
1222 *
1223 * @sk: sock from which to allocate memory
1224 * @opt: original options
1225 * @newtype: option type to replace in @opt
1226 * @newopt: new option of type @newtype to replace (user-mem)
1227 *
1228 * Returns a new set of options which is a copy of @opt with the
1229 * option type @newtype replaced with @newopt.
1230 *
1231 * @opt may be NULL, in which case a new set of options is returned
1232 * containing just @newopt.
1233 *
1234 * @newopt may be NULL, in which case the specified option type is
1235 * not copied into the new set of options.
1236 *
1237 * The new set of options is allocated from the socket option memory
1238 * buffer of @sk.
1239 */
1240 struct ipv6_txoptions *
ipv6_renew_options(struct sock * sk,struct ipv6_txoptions * opt,int newtype,struct ipv6_opt_hdr * newopt)1241 ipv6_renew_options(struct sock *sk, struct ipv6_txoptions *opt,
1242 int newtype, struct ipv6_opt_hdr *newopt)
1243 {
1244 int tot_len = 0;
1245 char *p;
1246 struct ipv6_txoptions *opt2;
1247
1248 if (opt) {
1249 if (newtype != IPV6_HOPOPTS && opt->hopopt)
1250 tot_len += CMSG_ALIGN(ipv6_optlen(opt->hopopt));
1251 if (newtype != IPV6_RTHDRDSTOPTS && opt->dst0opt)
1252 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst0opt));
1253 if (newtype != IPV6_RTHDR && opt->srcrt)
1254 tot_len += CMSG_ALIGN(ipv6_optlen(opt->srcrt));
1255 if (newtype != IPV6_DSTOPTS && opt->dst1opt)
1256 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst1opt));
1257 }
1258
1259 if (newopt)
1260 tot_len += CMSG_ALIGN(ipv6_optlen(newopt));
1261
1262 if (!tot_len)
1263 return NULL;
1264
1265 tot_len += sizeof(*opt2);
1266 opt2 = sock_kmalloc(sk, tot_len, GFP_ATOMIC);
1267 if (!opt2)
1268 return ERR_PTR(-ENOBUFS);
1269
1270 memset(opt2, 0, tot_len);
1271 refcount_set(&opt2->refcnt, 1);
1272 opt2->tot_len = tot_len;
1273 p = (char *)(opt2 + 1);
1274
1275 ipv6_renew_option(IPV6_HOPOPTS, &opt2->hopopt,
1276 (opt ? opt->hopopt : NULL),
1277 newopt, newtype, &p);
1278 ipv6_renew_option(IPV6_RTHDRDSTOPTS, &opt2->dst0opt,
1279 (opt ? opt->dst0opt : NULL),
1280 newopt, newtype, &p);
1281 ipv6_renew_option(IPV6_RTHDR,
1282 (struct ipv6_opt_hdr **)&opt2->srcrt,
1283 (opt ? (struct ipv6_opt_hdr *)opt->srcrt : NULL),
1284 newopt, newtype, &p);
1285 ipv6_renew_option(IPV6_DSTOPTS, &opt2->dst1opt,
1286 (opt ? opt->dst1opt : NULL),
1287 newopt, newtype, &p);
1288
1289 opt2->opt_nflen = (opt2->hopopt ? ipv6_optlen(opt2->hopopt) : 0) +
1290 (opt2->dst0opt ? ipv6_optlen(opt2->dst0opt) : 0) +
1291 (opt2->srcrt ? ipv6_optlen(opt2->srcrt) : 0);
1292 opt2->opt_flen = (opt2->dst1opt ? ipv6_optlen(opt2->dst1opt) : 0);
1293
1294 return opt2;
1295 }
1296
ipv6_fixup_options(struct ipv6_txoptions * opt_space,struct ipv6_txoptions * opt)1297 struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space,
1298 struct ipv6_txoptions *opt)
1299 {
1300 /*
1301 * ignore the dest before srcrt unless srcrt is being included.
1302 * --yoshfuji
1303 */
1304 if (opt && opt->dst0opt && !opt->srcrt) {
1305 if (opt_space != opt) {
1306 memcpy(opt_space, opt, sizeof(*opt_space));
1307 opt = opt_space;
1308 }
1309 opt->opt_nflen -= ipv6_optlen(opt->dst0opt);
1310 opt->dst0opt = NULL;
1311 }
1312
1313 return opt;
1314 }
1315 EXPORT_SYMBOL_GPL(ipv6_fixup_options);
1316
1317 /**
1318 * fl6_update_dst - update flowi destination address with info given
1319 * by srcrt option, if any.
1320 *
1321 * @fl6: flowi6 for which daddr is to be updated
1322 * @opt: struct ipv6_txoptions in which to look for srcrt opt
1323 * @orig: copy of original daddr address if modified
1324 *
1325 * Returns NULL if no txoptions or no srcrt, otherwise returns orig
1326 * and initial value of fl6->daddr set in orig
1327 */
fl6_update_dst(struct flowi6 * fl6,const struct ipv6_txoptions * opt,struct in6_addr * orig)1328 struct in6_addr *fl6_update_dst(struct flowi6 *fl6,
1329 const struct ipv6_txoptions *opt,
1330 struct in6_addr *orig)
1331 {
1332 if (!opt || !opt->srcrt)
1333 return NULL;
1334
1335 *orig = fl6->daddr;
1336
1337 switch (opt->srcrt->type) {
1338 case IPV6_SRCRT_TYPE_0:
1339 case IPV6_SRCRT_STRICT:
1340 case IPV6_SRCRT_TYPE_2:
1341 fl6->daddr = *((struct rt0_hdr *)opt->srcrt)->addr;
1342 break;
1343 case IPV6_SRCRT_TYPE_4:
1344 {
1345 struct ipv6_sr_hdr *srh = (struct ipv6_sr_hdr *)opt->srcrt;
1346
1347 fl6->daddr = srh->segments[srh->segments_left];
1348 break;
1349 }
1350 default:
1351 return NULL;
1352 }
1353
1354 return orig;
1355 }
1356 EXPORT_SYMBOL_GPL(fl6_update_dst);
1357