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(skb, ICMPV6_UNK_OPTION, optoff);
94 return false;
95 }
96
97 drop:
98 kfree_skb(skb);
99 return false;
100 }
101
102 static bool ipv6_hop_ra(struct sk_buff *skb, int optoff);
103 static bool ipv6_hop_ioam(struct sk_buff *skb, int optoff);
104 static bool ipv6_hop_jumbo(struct sk_buff *skb, int optoff);
105 static bool ipv6_hop_calipso(struct sk_buff *skb, int optoff);
106 #if IS_ENABLED(CONFIG_IPV6_MIP6)
107 static bool ipv6_dest_hao(struct sk_buff *skb, int optoff);
108 #endif
109
110 /* Parse tlv encoded option header (hop-by-hop or destination) */
111
ip6_parse_tlv(bool hopbyhop,struct sk_buff * skb,int max_count)112 static bool ip6_parse_tlv(bool hopbyhop,
113 struct sk_buff *skb,
114 int max_count)
115 {
116 int len = (skb_transport_header(skb)[1] + 1) << 3;
117 const unsigned char *nh = skb_network_header(skb);
118 int off = skb_network_header_len(skb);
119 bool disallow_unknowns = false;
120 int tlv_count = 0;
121 int padlen = 0;
122
123 if (unlikely(max_count < 0)) {
124 disallow_unknowns = true;
125 max_count = -max_count;
126 }
127
128 if (skb_transport_offset(skb) + len > skb_headlen(skb))
129 goto bad;
130
131 off += 2;
132 len -= 2;
133
134 while (len > 0) {
135 int optlen, i;
136
137 if (nh[off] == IPV6_TLV_PAD1) {
138 padlen++;
139 if (padlen > 7)
140 goto bad;
141 off++;
142 len--;
143 continue;
144 }
145 if (len < 2)
146 goto bad;
147 optlen = nh[off + 1] + 2;
148 if (optlen > len)
149 goto bad;
150
151 if (nh[off] == IPV6_TLV_PADN) {
152 /* RFC 2460 states that the purpose of PadN is
153 * to align the containing header to multiples
154 * of 8. 7 is therefore the highest valid value.
155 * See also RFC 4942, Section 2.1.9.5.
156 */
157 padlen += optlen;
158 if (padlen > 7)
159 goto bad;
160 /* RFC 4942 recommends receiving hosts to
161 * actively check PadN payload to contain
162 * only zeroes.
163 */
164 for (i = 2; i < optlen; i++) {
165 if (nh[off + i] != 0)
166 goto bad;
167 }
168 } else {
169 tlv_count++;
170 if (tlv_count > max_count)
171 goto bad;
172
173 if (hopbyhop) {
174 switch (nh[off]) {
175 case IPV6_TLV_ROUTERALERT:
176 if (!ipv6_hop_ra(skb, off))
177 return false;
178 break;
179 case IPV6_TLV_IOAM:
180 if (!ipv6_hop_ioam(skb, off))
181 return false;
182 break;
183 case IPV6_TLV_JUMBO:
184 if (!ipv6_hop_jumbo(skb, off))
185 return false;
186 break;
187 case IPV6_TLV_CALIPSO:
188 if (!ipv6_hop_calipso(skb, off))
189 return false;
190 break;
191 default:
192 if (!ip6_tlvopt_unknown(skb, off,
193 disallow_unknowns))
194 return false;
195 break;
196 }
197 } else {
198 switch (nh[off]) {
199 #if IS_ENABLED(CONFIG_IPV6_MIP6)
200 case IPV6_TLV_HAO:
201 if (!ipv6_dest_hao(skb, off))
202 return false;
203 break;
204 #endif
205 default:
206 if (!ip6_tlvopt_unknown(skb, off,
207 disallow_unknowns))
208 return false;
209 break;
210 }
211 }
212 padlen = 0;
213 }
214 off += optlen;
215 len -= optlen;
216 }
217
218 if (len == 0)
219 return true;
220 bad:
221 kfree_skb(skb);
222 return false;
223 }
224
225 /*****************************
226 Destination options header.
227 *****************************/
228
229 #if IS_ENABLED(CONFIG_IPV6_MIP6)
ipv6_dest_hao(struct sk_buff * skb,int optoff)230 static bool ipv6_dest_hao(struct sk_buff *skb, int optoff)
231 {
232 struct ipv6_destopt_hao *hao;
233 struct inet6_skb_parm *opt = IP6CB(skb);
234 struct ipv6hdr *ipv6h = ipv6_hdr(skb);
235 int ret;
236
237 if (opt->dsthao) {
238 net_dbg_ratelimited("hao duplicated\n");
239 goto discard;
240 }
241 opt->dsthao = opt->dst1;
242 opt->dst1 = 0;
243
244 hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) + optoff);
245
246 if (hao->length != 16) {
247 net_dbg_ratelimited("hao invalid option length = %d\n",
248 hao->length);
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 goto discard;
256 }
257
258 ret = xfrm6_input_addr(skb, (xfrm_address_t *)&ipv6h->daddr,
259 (xfrm_address_t *)&hao->addr, IPPROTO_DSTOPTS);
260 if (unlikely(ret < 0))
261 goto discard;
262
263 if (skb_cloned(skb)) {
264 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
265 goto discard;
266
267 /* update all variable using below by copied skbuff */
268 hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) +
269 optoff);
270 ipv6h = ipv6_hdr(skb);
271 }
272
273 if (skb->ip_summed == CHECKSUM_COMPLETE)
274 skb->ip_summed = CHECKSUM_NONE;
275
276 swap(ipv6h->saddr, hao->addr);
277
278 if (skb->tstamp == 0)
279 __net_timestamp(skb);
280
281 return true;
282
283 discard:
284 kfree_skb(skb);
285 return false;
286 }
287 #endif
288
ipv6_destopt_rcv(struct sk_buff * skb)289 static int ipv6_destopt_rcv(struct sk_buff *skb)
290 {
291 struct inet6_dev *idev = __in6_dev_get(skb->dev);
292 struct inet6_skb_parm *opt = IP6CB(skb);
293 #if IS_ENABLED(CONFIG_IPV6_MIP6)
294 __u16 dstbuf;
295 #endif
296 struct dst_entry *dst = skb_dst(skb);
297 struct net *net = dev_net(skb->dev);
298 int extlen;
299
300 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
301 !pskb_may_pull(skb, (skb_transport_offset(skb) +
302 ((skb_transport_header(skb)[1] + 1) << 3)))) {
303 __IP6_INC_STATS(dev_net(dst->dev), idev,
304 IPSTATS_MIB_INHDRERRORS);
305 fail_and_free:
306 kfree_skb(skb);
307 return -1;
308 }
309
310 extlen = (skb_transport_header(skb)[1] + 1) << 3;
311 if (extlen > net->ipv6.sysctl.max_dst_opts_len)
312 goto fail_and_free;
313
314 opt->lastopt = opt->dst1 = skb_network_header_len(skb);
315 #if IS_ENABLED(CONFIG_IPV6_MIP6)
316 dstbuf = opt->dst1;
317 #endif
318
319 if (ip6_parse_tlv(false, skb, net->ipv6.sysctl.max_dst_opts_cnt)) {
320 skb->transport_header += extlen;
321 opt = IP6CB(skb);
322 #if IS_ENABLED(CONFIG_IPV6_MIP6)
323 opt->nhoff = dstbuf;
324 #else
325 opt->nhoff = opt->dst1;
326 #endif
327 return 1;
328 }
329
330 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
331 return -1;
332 }
333
seg6_update_csum(struct sk_buff * skb)334 static void seg6_update_csum(struct sk_buff *skb)
335 {
336 struct ipv6_sr_hdr *hdr;
337 struct in6_addr *addr;
338 __be32 from, to;
339
340 /* srh is at transport offset and seg_left is already decremented
341 * but daddr is not yet updated with next segment
342 */
343
344 hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb);
345 addr = hdr->segments + hdr->segments_left;
346
347 hdr->segments_left++;
348 from = *(__be32 *)hdr;
349
350 hdr->segments_left--;
351 to = *(__be32 *)hdr;
352
353 /* update skb csum with diff resulting from seg_left decrement */
354
355 update_csum_diff4(skb, from, to);
356
357 /* compute csum diff between current and next segment and update */
358
359 update_csum_diff16(skb, (__be32 *)(&ipv6_hdr(skb)->daddr),
360 (__be32 *)addr);
361 }
362
ipv6_srh_rcv(struct sk_buff * skb)363 static int ipv6_srh_rcv(struct sk_buff *skb)
364 {
365 struct inet6_skb_parm *opt = IP6CB(skb);
366 struct net *net = dev_net(skb->dev);
367 struct ipv6_sr_hdr *hdr;
368 struct inet6_dev *idev;
369 struct in6_addr *addr;
370 int accept_seg6;
371
372 hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb);
373
374 idev = __in6_dev_get(skb->dev);
375
376 accept_seg6 = net->ipv6.devconf_all->seg6_enabled;
377 if (accept_seg6 > idev->cnf.seg6_enabled)
378 accept_seg6 = idev->cnf.seg6_enabled;
379
380 if (!accept_seg6) {
381 kfree_skb(skb);
382 return -1;
383 }
384
385 #ifdef CONFIG_IPV6_SEG6_HMAC
386 if (!seg6_hmac_validate_skb(skb)) {
387 kfree_skb(skb);
388 return -1;
389 }
390 #endif
391
392 looped_back:
393 if (hdr->segments_left == 0) {
394 if (hdr->nexthdr == NEXTHDR_IPV6 || hdr->nexthdr == NEXTHDR_IPV4) {
395 int offset = (hdr->hdrlen + 1) << 3;
396
397 skb_postpull_rcsum(skb, skb_network_header(skb),
398 skb_network_header_len(skb));
399
400 if (!pskb_pull(skb, offset)) {
401 kfree_skb(skb);
402 return -1;
403 }
404 skb_postpull_rcsum(skb, skb_transport_header(skb),
405 offset);
406
407 skb_reset_network_header(skb);
408 skb_reset_transport_header(skb);
409 skb->encapsulation = 0;
410 if (hdr->nexthdr == NEXTHDR_IPV4)
411 skb->protocol = htons(ETH_P_IP);
412 __skb_tunnel_rx(skb, skb->dev, net);
413
414 netif_rx(skb);
415 return -1;
416 }
417
418 opt->srcrt = skb_network_header_len(skb);
419 opt->lastopt = opt->srcrt;
420 skb->transport_header += (hdr->hdrlen + 1) << 3;
421 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb);
422
423 return 1;
424 }
425
426 if (hdr->segments_left >= (hdr->hdrlen >> 1)) {
427 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
428 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
429 ((&hdr->segments_left) -
430 skb_network_header(skb)));
431 return -1;
432 }
433
434 if (skb_cloned(skb)) {
435 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) {
436 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
437 IPSTATS_MIB_OUTDISCARDS);
438 kfree_skb(skb);
439 return -1;
440 }
441 }
442
443 hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb);
444
445 hdr->segments_left--;
446 addr = hdr->segments + hdr->segments_left;
447
448 skb_push(skb, sizeof(struct ipv6hdr));
449
450 if (skb->ip_summed == CHECKSUM_COMPLETE)
451 seg6_update_csum(skb);
452
453 ipv6_hdr(skb)->daddr = *addr;
454
455 skb_dst_drop(skb);
456
457 ip6_route_input(skb);
458
459 if (skb_dst(skb)->error) {
460 dst_input(skb);
461 return -1;
462 }
463
464 if (skb_dst(skb)->dev->flags & IFF_LOOPBACK) {
465 if (ipv6_hdr(skb)->hop_limit <= 1) {
466 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
467 icmpv6_send(skb, ICMPV6_TIME_EXCEED,
468 ICMPV6_EXC_HOPLIMIT, 0);
469 kfree_skb(skb);
470 return -1;
471 }
472 ipv6_hdr(skb)->hop_limit--;
473
474 skb_pull(skb, sizeof(struct ipv6hdr));
475 goto looped_back;
476 }
477
478 dst_input(skb);
479
480 return -1;
481 }
482
ipv6_rpl_srh_rcv(struct sk_buff * skb)483 static int ipv6_rpl_srh_rcv(struct sk_buff *skb)
484 {
485 struct ipv6_rpl_sr_hdr *hdr, *ohdr, *chdr;
486 struct inet6_skb_parm *opt = IP6CB(skb);
487 struct net *net = dev_net(skb->dev);
488 struct inet6_dev *idev;
489 struct ipv6hdr *oldhdr;
490 struct in6_addr addr;
491 unsigned char *buf;
492 int accept_rpl_seg;
493 int i, err;
494 u64 n = 0;
495 u32 r;
496
497 idev = __in6_dev_get(skb->dev);
498
499 accept_rpl_seg = net->ipv6.devconf_all->rpl_seg_enabled;
500 if (accept_rpl_seg > idev->cnf.rpl_seg_enabled)
501 accept_rpl_seg = idev->cnf.rpl_seg_enabled;
502
503 if (!accept_rpl_seg) {
504 kfree_skb(skb);
505 return -1;
506 }
507
508 looped_back:
509 hdr = (struct ipv6_rpl_sr_hdr *)skb_transport_header(skb);
510
511 if (hdr->segments_left == 0) {
512 if (hdr->nexthdr == NEXTHDR_IPV6) {
513 int offset = (hdr->hdrlen + 1) << 3;
514
515 skb_postpull_rcsum(skb, skb_network_header(skb),
516 skb_network_header_len(skb));
517
518 if (!pskb_pull(skb, offset)) {
519 kfree_skb(skb);
520 return -1;
521 }
522 skb_postpull_rcsum(skb, skb_transport_header(skb),
523 offset);
524
525 skb_reset_network_header(skb);
526 skb_reset_transport_header(skb);
527 skb->encapsulation = 0;
528
529 __skb_tunnel_rx(skb, skb->dev, net);
530
531 netif_rx(skb);
532 return -1;
533 }
534
535 opt->srcrt = skb_network_header_len(skb);
536 opt->lastopt = opt->srcrt;
537 skb->transport_header += (hdr->hdrlen + 1) << 3;
538 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb);
539
540 return 1;
541 }
542
543 if (!pskb_may_pull(skb, sizeof(*hdr))) {
544 kfree_skb(skb);
545 return -1;
546 }
547
548 n = (hdr->hdrlen << 3) - hdr->pad - (16 - hdr->cmpre);
549 r = do_div(n, (16 - hdr->cmpri));
550 /* checks if calculation was without remainder and n fits into
551 * unsigned char which is segments_left field. Should not be
552 * higher than that.
553 */
554 if (r || (n + 1) > 255) {
555 kfree_skb(skb);
556 return -1;
557 }
558
559 if (hdr->segments_left > n + 1) {
560 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
561 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
562 ((&hdr->segments_left) -
563 skb_network_header(skb)));
564 return -1;
565 }
566
567 if (skb_cloned(skb)) {
568 if (pskb_expand_head(skb, IPV6_RPL_SRH_WORST_SWAP_SIZE, 0,
569 GFP_ATOMIC)) {
570 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
571 IPSTATS_MIB_OUTDISCARDS);
572 kfree_skb(skb);
573 return -1;
574 }
575 } else {
576 err = skb_cow_head(skb, IPV6_RPL_SRH_WORST_SWAP_SIZE);
577 if (unlikely(err)) {
578 kfree_skb(skb);
579 return -1;
580 }
581 }
582
583 hdr = (struct ipv6_rpl_sr_hdr *)skb_transport_header(skb);
584
585 if (!pskb_may_pull(skb, ipv6_rpl_srh_size(n, hdr->cmpri,
586 hdr->cmpre))) {
587 kfree_skb(skb);
588 return -1;
589 }
590
591 hdr->segments_left--;
592 i = n - hdr->segments_left;
593
594 buf = kcalloc(struct_size(hdr, segments.addr, n + 2), 2, GFP_ATOMIC);
595 if (unlikely(!buf)) {
596 kfree_skb(skb);
597 return -1;
598 }
599
600 ohdr = (struct ipv6_rpl_sr_hdr *)buf;
601 ipv6_rpl_srh_decompress(ohdr, hdr, &ipv6_hdr(skb)->daddr, n);
602 chdr = (struct ipv6_rpl_sr_hdr *)(buf + ((ohdr->hdrlen + 1) << 3));
603
604 if ((ipv6_addr_type(&ipv6_hdr(skb)->daddr) & IPV6_ADDR_MULTICAST) ||
605 (ipv6_addr_type(&ohdr->rpl_segaddr[i]) & IPV6_ADDR_MULTICAST)) {
606 kfree_skb(skb);
607 kfree(buf);
608 return -1;
609 }
610
611 err = ipv6_chk_rpl_srh_loop(net, ohdr->rpl_segaddr, n + 1);
612 if (err) {
613 icmpv6_send(skb, ICMPV6_PARAMPROB, 0, 0);
614 kfree_skb(skb);
615 kfree(buf);
616 return -1;
617 }
618
619 addr = ipv6_hdr(skb)->daddr;
620 ipv6_hdr(skb)->daddr = ohdr->rpl_segaddr[i];
621 ohdr->rpl_segaddr[i] = addr;
622
623 ipv6_rpl_srh_compress(chdr, ohdr, &ipv6_hdr(skb)->daddr, n);
624
625 oldhdr = ipv6_hdr(skb);
626
627 skb_pull(skb, ((hdr->hdrlen + 1) << 3));
628 skb_postpull_rcsum(skb, oldhdr,
629 sizeof(struct ipv6hdr) + ((hdr->hdrlen + 1) << 3));
630 skb_push(skb, ((chdr->hdrlen + 1) << 3) + sizeof(struct ipv6hdr));
631 skb_reset_network_header(skb);
632 skb_mac_header_rebuild(skb);
633 skb_set_transport_header(skb, sizeof(struct ipv6hdr));
634
635 memmove(ipv6_hdr(skb), oldhdr, sizeof(struct ipv6hdr));
636 memcpy(skb_transport_header(skb), chdr, (chdr->hdrlen + 1) << 3);
637
638 ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
639 skb_postpush_rcsum(skb, ipv6_hdr(skb),
640 sizeof(struct ipv6hdr) + ((chdr->hdrlen + 1) << 3));
641
642 kfree(buf);
643
644 skb_dst_drop(skb);
645
646 ip6_route_input(skb);
647
648 if (skb_dst(skb)->error) {
649 dst_input(skb);
650 return -1;
651 }
652
653 if (skb_dst(skb)->dev->flags & IFF_LOOPBACK) {
654 if (ipv6_hdr(skb)->hop_limit <= 1) {
655 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
656 icmpv6_send(skb, ICMPV6_TIME_EXCEED,
657 ICMPV6_EXC_HOPLIMIT, 0);
658 kfree_skb(skb);
659 return -1;
660 }
661 ipv6_hdr(skb)->hop_limit--;
662
663 skb_pull(skb, sizeof(struct ipv6hdr));
664 goto looped_back;
665 }
666
667 dst_input(skb);
668
669 return -1;
670 }
671
672 /********************************
673 Routing header.
674 ********************************/
675
676 /* called with rcu_read_lock() */
ipv6_rthdr_rcv(struct sk_buff * skb)677 static int ipv6_rthdr_rcv(struct sk_buff *skb)
678 {
679 struct inet6_dev *idev = __in6_dev_get(skb->dev);
680 struct inet6_skb_parm *opt = IP6CB(skb);
681 struct in6_addr *addr = NULL;
682 struct in6_addr daddr;
683 int n, i;
684 struct ipv6_rt_hdr *hdr;
685 struct rt0_hdr *rthdr;
686 struct net *net = dev_net(skb->dev);
687 int accept_source_route = net->ipv6.devconf_all->accept_source_route;
688
689 idev = __in6_dev_get(skb->dev);
690 if (idev && accept_source_route > idev->cnf.accept_source_route)
691 accept_source_route = idev->cnf.accept_source_route;
692
693 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
694 !pskb_may_pull(skb, (skb_transport_offset(skb) +
695 ((skb_transport_header(skb)[1] + 1) << 3)))) {
696 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
697 kfree_skb(skb);
698 return -1;
699 }
700
701 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb);
702
703 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) ||
704 skb->pkt_type != PACKET_HOST) {
705 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
706 kfree_skb(skb);
707 return -1;
708 }
709
710 switch (hdr->type) {
711 case IPV6_SRCRT_TYPE_4:
712 /* segment routing */
713 return ipv6_srh_rcv(skb);
714 case IPV6_SRCRT_TYPE_3:
715 /* rpl segment routing */
716 return ipv6_rpl_srh_rcv(skb);
717 default:
718 break;
719 }
720
721 looped_back:
722 if (hdr->segments_left == 0) {
723 switch (hdr->type) {
724 #if IS_ENABLED(CONFIG_IPV6_MIP6)
725 case IPV6_SRCRT_TYPE_2:
726 /* Silently discard type 2 header unless it was
727 * processed by own
728 */
729 if (!addr) {
730 __IP6_INC_STATS(net, idev,
731 IPSTATS_MIB_INADDRERRORS);
732 kfree_skb(skb);
733 return -1;
734 }
735 break;
736 #endif
737 default:
738 break;
739 }
740
741 opt->lastopt = opt->srcrt = skb_network_header_len(skb);
742 skb->transport_header += (hdr->hdrlen + 1) << 3;
743 opt->dst0 = opt->dst1;
744 opt->dst1 = 0;
745 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb);
746 return 1;
747 }
748
749 switch (hdr->type) {
750 #if IS_ENABLED(CONFIG_IPV6_MIP6)
751 case IPV6_SRCRT_TYPE_2:
752 if (accept_source_route < 0)
753 goto unknown_rh;
754 /* Silently discard invalid RTH type 2 */
755 if (hdr->hdrlen != 2 || hdr->segments_left != 1) {
756 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
757 kfree_skb(skb);
758 return -1;
759 }
760 break;
761 #endif
762 default:
763 goto unknown_rh;
764 }
765
766 /*
767 * This is the routing header forwarding algorithm from
768 * RFC 2460, page 16.
769 */
770
771 n = hdr->hdrlen >> 1;
772
773 if (hdr->segments_left > n) {
774 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
775 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
776 ((&hdr->segments_left) -
777 skb_network_header(skb)));
778 return -1;
779 }
780
781 /* We are about to mangle packet header. Be careful!
782 Do not damage packets queued somewhere.
783 */
784 if (skb_cloned(skb)) {
785 /* the copy is a forwarded packet */
786 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) {
787 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
788 IPSTATS_MIB_OUTDISCARDS);
789 kfree_skb(skb);
790 return -1;
791 }
792 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb);
793 }
794
795 if (skb->ip_summed == CHECKSUM_COMPLETE)
796 skb->ip_summed = CHECKSUM_NONE;
797
798 i = n - --hdr->segments_left;
799
800 rthdr = (struct rt0_hdr *) hdr;
801 addr = rthdr->addr;
802 addr += i - 1;
803
804 switch (hdr->type) {
805 #if IS_ENABLED(CONFIG_IPV6_MIP6)
806 case IPV6_SRCRT_TYPE_2:
807 if (xfrm6_input_addr(skb, (xfrm_address_t *)addr,
808 (xfrm_address_t *)&ipv6_hdr(skb)->saddr,
809 IPPROTO_ROUTING) < 0) {
810 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
811 kfree_skb(skb);
812 return -1;
813 }
814 if (!ipv6_chk_home_addr(dev_net(skb_dst(skb)->dev), addr)) {
815 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
816 kfree_skb(skb);
817 return -1;
818 }
819 break;
820 #endif
821 default:
822 break;
823 }
824
825 if (ipv6_addr_is_multicast(addr)) {
826 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
827 kfree_skb(skb);
828 return -1;
829 }
830
831 daddr = *addr;
832 *addr = ipv6_hdr(skb)->daddr;
833 ipv6_hdr(skb)->daddr = daddr;
834
835 skb_dst_drop(skb);
836 ip6_route_input(skb);
837 if (skb_dst(skb)->error) {
838 skb_push(skb, skb->data - skb_network_header(skb));
839 dst_input(skb);
840 return -1;
841 }
842
843 if (skb_dst(skb)->dev->flags&IFF_LOOPBACK) {
844 if (ipv6_hdr(skb)->hop_limit <= 1) {
845 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
846 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
847 0);
848 kfree_skb(skb);
849 return -1;
850 }
851 ipv6_hdr(skb)->hop_limit--;
852 goto looped_back;
853 }
854
855 skb_push(skb, skb->data - skb_network_header(skb));
856 dst_input(skb);
857 return -1;
858
859 unknown_rh:
860 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
861 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
862 (&hdr->type) - skb_network_header(skb));
863 return -1;
864 }
865
866 static const struct inet6_protocol rthdr_protocol = {
867 .handler = ipv6_rthdr_rcv,
868 .flags = INET6_PROTO_NOPOLICY,
869 };
870
871 static const struct inet6_protocol destopt_protocol = {
872 .handler = ipv6_destopt_rcv,
873 .flags = INET6_PROTO_NOPOLICY,
874 };
875
876 static const struct inet6_protocol nodata_protocol = {
877 .handler = dst_discard,
878 .flags = INET6_PROTO_NOPOLICY,
879 };
880
ipv6_exthdrs_init(void)881 int __init ipv6_exthdrs_init(void)
882 {
883 int ret;
884
885 ret = inet6_add_protocol(&rthdr_protocol, IPPROTO_ROUTING);
886 if (ret)
887 goto out;
888
889 ret = inet6_add_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
890 if (ret)
891 goto out_rthdr;
892
893 ret = inet6_add_protocol(&nodata_protocol, IPPROTO_NONE);
894 if (ret)
895 goto out_destopt;
896
897 out:
898 return ret;
899 out_destopt:
900 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
901 out_rthdr:
902 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING);
903 goto out;
904 };
905
ipv6_exthdrs_exit(void)906 void ipv6_exthdrs_exit(void)
907 {
908 inet6_del_protocol(&nodata_protocol, IPPROTO_NONE);
909 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
910 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING);
911 }
912
913 /**********************************
914 Hop-by-hop options.
915 **********************************/
916
917 /*
918 * Note: we cannot rely on skb_dst(skb) before we assign it in ip6_route_input().
919 */
ipv6_skb_net(struct sk_buff * skb)920 static inline struct net *ipv6_skb_net(struct sk_buff *skb)
921 {
922 return skb_dst(skb) ? dev_net(skb_dst(skb)->dev) : dev_net(skb->dev);
923 }
924
925 /* Router Alert as of RFC 2711 */
926
ipv6_hop_ra(struct sk_buff * skb,int optoff)927 static bool ipv6_hop_ra(struct sk_buff *skb, int optoff)
928 {
929 const unsigned char *nh = skb_network_header(skb);
930
931 if (nh[optoff + 1] == 2) {
932 IP6CB(skb)->flags |= IP6SKB_ROUTERALERT;
933 memcpy(&IP6CB(skb)->ra, nh + optoff + 2, sizeof(IP6CB(skb)->ra));
934 return true;
935 }
936 net_dbg_ratelimited("ipv6_hop_ra: wrong RA length %d\n",
937 nh[optoff + 1]);
938 kfree_skb(skb);
939 return false;
940 }
941
942 /* IOAM */
943
ipv6_hop_ioam(struct sk_buff * skb,int optoff)944 static bool ipv6_hop_ioam(struct sk_buff *skb, int optoff)
945 {
946 struct ioam6_trace_hdr *trace;
947 struct ioam6_namespace *ns;
948 struct ioam6_hdr *hdr;
949
950 /* Bad alignment (must be 4n-aligned) */
951 if (optoff & 3)
952 goto drop;
953
954 /* Ignore if IOAM is not enabled on ingress */
955 if (!__in6_dev_get(skb->dev)->cnf.ioam6_enabled)
956 goto ignore;
957
958 /* Truncated Option header */
959 hdr = (struct ioam6_hdr *)(skb_network_header(skb) + optoff);
960 if (hdr->opt_len < 2)
961 goto drop;
962
963 switch (hdr->type) {
964 case IOAM6_TYPE_PREALLOC:
965 /* Truncated Pre-allocated Trace header */
966 if (hdr->opt_len < 2 + sizeof(*trace))
967 goto drop;
968
969 /* Malformed Pre-allocated Trace header */
970 trace = (struct ioam6_trace_hdr *)((u8 *)hdr + sizeof(*hdr));
971 if (hdr->opt_len < 2 + sizeof(*trace) + trace->remlen * 4)
972 goto drop;
973
974 /* Ignore if the IOAM namespace is unknown */
975 ns = ioam6_namespace(ipv6_skb_net(skb), trace->namespace_id);
976 if (!ns)
977 goto ignore;
978
979 if (!skb_valid_dst(skb))
980 ip6_route_input(skb);
981
982 ioam6_fill_trace_data(skb, ns, trace);
983 break;
984 default:
985 break;
986 }
987
988 ignore:
989 return true;
990
991 drop:
992 kfree_skb(skb);
993 return false;
994 }
995
996 /* Jumbo payload */
997
ipv6_hop_jumbo(struct sk_buff * skb,int optoff)998 static bool ipv6_hop_jumbo(struct sk_buff *skb, int optoff)
999 {
1000 const unsigned char *nh = skb_network_header(skb);
1001 struct inet6_dev *idev = __in6_dev_get_safely(skb->dev);
1002 struct net *net = ipv6_skb_net(skb);
1003 u32 pkt_len;
1004
1005 if (nh[optoff + 1] != 4 || (optoff & 3) != 2) {
1006 net_dbg_ratelimited("ipv6_hop_jumbo: wrong jumbo opt length/alignment %d\n",
1007 nh[optoff+1]);
1008 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
1009 goto drop;
1010 }
1011
1012 pkt_len = ntohl(*(__be32 *)(nh + optoff + 2));
1013 if (pkt_len <= IPV6_MAXPLEN) {
1014 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
1015 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff+2);
1016 return false;
1017 }
1018 if (ipv6_hdr(skb)->payload_len) {
1019 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
1020 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff);
1021 return false;
1022 }
1023
1024 if (pkt_len > skb->len - sizeof(struct ipv6hdr)) {
1025 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INTRUNCATEDPKTS);
1026 goto drop;
1027 }
1028
1029 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr)))
1030 goto drop;
1031
1032 IP6CB(skb)->flags |= IP6SKB_JUMBOGRAM;
1033 return true;
1034
1035 drop:
1036 kfree_skb(skb);
1037 return false;
1038 }
1039
1040 /* CALIPSO RFC 5570 */
1041
ipv6_hop_calipso(struct sk_buff * skb,int optoff)1042 static bool ipv6_hop_calipso(struct sk_buff *skb, int optoff)
1043 {
1044 const unsigned char *nh = skb_network_header(skb);
1045
1046 if (nh[optoff + 1] < 8)
1047 goto drop;
1048
1049 if (nh[optoff + 6] * 4 + 8 > nh[optoff + 1])
1050 goto drop;
1051
1052 if (!calipso_validate(skb, nh + optoff))
1053 goto drop;
1054
1055 return true;
1056
1057 drop:
1058 kfree_skb(skb);
1059 return false;
1060 }
1061
ipv6_parse_hopopts(struct sk_buff * skb)1062 int ipv6_parse_hopopts(struct sk_buff *skb)
1063 {
1064 struct inet6_skb_parm *opt = IP6CB(skb);
1065 struct net *net = dev_net(skb->dev);
1066 int extlen;
1067
1068 /*
1069 * skb_network_header(skb) is equal to skb->data, and
1070 * skb_network_header_len(skb) is always equal to
1071 * sizeof(struct ipv6hdr) by definition of
1072 * hop-by-hop options.
1073 */
1074 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + 8) ||
1075 !pskb_may_pull(skb, (sizeof(struct ipv6hdr) +
1076 ((skb_transport_header(skb)[1] + 1) << 3)))) {
1077 fail_and_free:
1078 kfree_skb(skb);
1079 return -1;
1080 }
1081
1082 extlen = (skb_transport_header(skb)[1] + 1) << 3;
1083 if (extlen > net->ipv6.sysctl.max_hbh_opts_len)
1084 goto fail_and_free;
1085
1086 opt->flags |= IP6SKB_HOPBYHOP;
1087 if (ip6_parse_tlv(true, skb, net->ipv6.sysctl.max_hbh_opts_cnt)) {
1088 skb->transport_header += extlen;
1089 opt = IP6CB(skb);
1090 opt->nhoff = sizeof(struct ipv6hdr);
1091 return 1;
1092 }
1093 return -1;
1094 }
1095
1096 /*
1097 * Creating outbound headers.
1098 *
1099 * "build" functions work when skb is filled from head to tail (datagram)
1100 * "push" functions work when headers are added from tail to head (tcp)
1101 *
1102 * In both cases we assume, that caller reserved enough room
1103 * for headers.
1104 */
1105
ipv6_push_rthdr0(struct sk_buff * skb,u8 * proto,struct ipv6_rt_hdr * opt,struct in6_addr ** addr_p,struct in6_addr * saddr)1106 static void ipv6_push_rthdr0(struct sk_buff *skb, u8 *proto,
1107 struct ipv6_rt_hdr *opt,
1108 struct in6_addr **addr_p, struct in6_addr *saddr)
1109 {
1110 struct rt0_hdr *phdr, *ihdr;
1111 int hops;
1112
1113 ihdr = (struct rt0_hdr *) opt;
1114
1115 phdr = skb_push(skb, (ihdr->rt_hdr.hdrlen + 1) << 3);
1116 memcpy(phdr, ihdr, sizeof(struct rt0_hdr));
1117
1118 hops = ihdr->rt_hdr.hdrlen >> 1;
1119
1120 if (hops > 1)
1121 memcpy(phdr->addr, ihdr->addr + 1,
1122 (hops - 1) * sizeof(struct in6_addr));
1123
1124 phdr->addr[hops - 1] = **addr_p;
1125 *addr_p = ihdr->addr;
1126
1127 phdr->rt_hdr.nexthdr = *proto;
1128 *proto = NEXTHDR_ROUTING;
1129 }
1130
ipv6_push_rthdr4(struct sk_buff * skb,u8 * proto,struct ipv6_rt_hdr * opt,struct in6_addr ** addr_p,struct in6_addr * saddr)1131 static void ipv6_push_rthdr4(struct sk_buff *skb, u8 *proto,
1132 struct ipv6_rt_hdr *opt,
1133 struct in6_addr **addr_p, struct in6_addr *saddr)
1134 {
1135 struct ipv6_sr_hdr *sr_phdr, *sr_ihdr;
1136 int plen, hops;
1137
1138 sr_ihdr = (struct ipv6_sr_hdr *)opt;
1139 plen = (sr_ihdr->hdrlen + 1) << 3;
1140
1141 sr_phdr = skb_push(skb, plen);
1142 memcpy(sr_phdr, sr_ihdr, sizeof(struct ipv6_sr_hdr));
1143
1144 hops = sr_ihdr->first_segment + 1;
1145 memcpy(sr_phdr->segments + 1, sr_ihdr->segments + 1,
1146 (hops - 1) * sizeof(struct in6_addr));
1147
1148 sr_phdr->segments[0] = **addr_p;
1149 *addr_p = &sr_ihdr->segments[sr_ihdr->segments_left];
1150
1151 if (sr_ihdr->hdrlen > hops * 2) {
1152 int tlvs_offset, tlvs_length;
1153
1154 tlvs_offset = (1 + hops * 2) << 3;
1155 tlvs_length = (sr_ihdr->hdrlen - hops * 2) << 3;
1156 memcpy((char *)sr_phdr + tlvs_offset,
1157 (char *)sr_ihdr + tlvs_offset, tlvs_length);
1158 }
1159
1160 #ifdef CONFIG_IPV6_SEG6_HMAC
1161 if (sr_has_hmac(sr_phdr)) {
1162 struct net *net = NULL;
1163
1164 if (skb->dev)
1165 net = dev_net(skb->dev);
1166 else if (skb->sk)
1167 net = sock_net(skb->sk);
1168
1169 WARN_ON(!net);
1170
1171 if (net)
1172 seg6_push_hmac(net, saddr, sr_phdr);
1173 }
1174 #endif
1175
1176 sr_phdr->nexthdr = *proto;
1177 *proto = NEXTHDR_ROUTING;
1178 }
1179
ipv6_push_rthdr(struct sk_buff * skb,u8 * proto,struct ipv6_rt_hdr * opt,struct in6_addr ** addr_p,struct in6_addr * saddr)1180 static void ipv6_push_rthdr(struct sk_buff *skb, u8 *proto,
1181 struct ipv6_rt_hdr *opt,
1182 struct in6_addr **addr_p, struct in6_addr *saddr)
1183 {
1184 switch (opt->type) {
1185 case IPV6_SRCRT_TYPE_0:
1186 case IPV6_SRCRT_STRICT:
1187 case IPV6_SRCRT_TYPE_2:
1188 ipv6_push_rthdr0(skb, proto, opt, addr_p, saddr);
1189 break;
1190 case IPV6_SRCRT_TYPE_4:
1191 ipv6_push_rthdr4(skb, proto, opt, addr_p, saddr);
1192 break;
1193 default:
1194 break;
1195 }
1196 }
1197
ipv6_push_exthdr(struct sk_buff * skb,u8 * proto,u8 type,struct ipv6_opt_hdr * opt)1198 static void ipv6_push_exthdr(struct sk_buff *skb, u8 *proto, u8 type, struct ipv6_opt_hdr *opt)
1199 {
1200 struct ipv6_opt_hdr *h = skb_push(skb, ipv6_optlen(opt));
1201
1202 memcpy(h, opt, ipv6_optlen(opt));
1203 h->nexthdr = *proto;
1204 *proto = type;
1205 }
1206
ipv6_push_nfrag_opts(struct sk_buff * skb,struct ipv6_txoptions * opt,u8 * proto,struct in6_addr ** daddr,struct in6_addr * saddr)1207 void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
1208 u8 *proto,
1209 struct in6_addr **daddr, struct in6_addr *saddr)
1210 {
1211 if (opt->srcrt) {
1212 ipv6_push_rthdr(skb, proto, opt->srcrt, daddr, saddr);
1213 /*
1214 * IPV6_RTHDRDSTOPTS is ignored
1215 * unless IPV6_RTHDR is set (RFC3542).
1216 */
1217 if (opt->dst0opt)
1218 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst0opt);
1219 }
1220 if (opt->hopopt)
1221 ipv6_push_exthdr(skb, proto, NEXTHDR_HOP, opt->hopopt);
1222 }
1223
ipv6_push_frag_opts(struct sk_buff * skb,struct ipv6_txoptions * opt,u8 * proto)1224 void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, u8 *proto)
1225 {
1226 if (opt->dst1opt)
1227 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst1opt);
1228 }
1229 EXPORT_SYMBOL(ipv6_push_frag_opts);
1230
1231 struct ipv6_txoptions *
ipv6_dup_options(struct sock * sk,struct ipv6_txoptions * opt)1232 ipv6_dup_options(struct sock *sk, struct ipv6_txoptions *opt)
1233 {
1234 struct ipv6_txoptions *opt2;
1235
1236 opt2 = sock_kmalloc(sk, opt->tot_len, GFP_ATOMIC);
1237 if (opt2) {
1238 long dif = (char *)opt2 - (char *)opt;
1239 memcpy(opt2, opt, opt->tot_len);
1240 if (opt2->hopopt)
1241 *((char **)&opt2->hopopt) += dif;
1242 if (opt2->dst0opt)
1243 *((char **)&opt2->dst0opt) += dif;
1244 if (opt2->dst1opt)
1245 *((char **)&opt2->dst1opt) += dif;
1246 if (opt2->srcrt)
1247 *((char **)&opt2->srcrt) += dif;
1248 refcount_set(&opt2->refcnt, 1);
1249 }
1250 return opt2;
1251 }
1252 EXPORT_SYMBOL_GPL(ipv6_dup_options);
1253
ipv6_renew_option(int renewtype,struct ipv6_opt_hdr ** dest,struct ipv6_opt_hdr * old,struct ipv6_opt_hdr * new,int newtype,char ** p)1254 static void ipv6_renew_option(int renewtype,
1255 struct ipv6_opt_hdr **dest,
1256 struct ipv6_opt_hdr *old,
1257 struct ipv6_opt_hdr *new,
1258 int newtype, char **p)
1259 {
1260 struct ipv6_opt_hdr *src;
1261
1262 src = (renewtype == newtype ? new : old);
1263 if (!src)
1264 return;
1265
1266 memcpy(*p, src, ipv6_optlen(src));
1267 *dest = (struct ipv6_opt_hdr *)*p;
1268 *p += CMSG_ALIGN(ipv6_optlen(*dest));
1269 }
1270
1271 /**
1272 * ipv6_renew_options - replace a specific ext hdr with a new one.
1273 *
1274 * @sk: sock from which to allocate memory
1275 * @opt: original options
1276 * @newtype: option type to replace in @opt
1277 * @newopt: new option of type @newtype to replace (user-mem)
1278 *
1279 * Returns a new set of options which is a copy of @opt with the
1280 * option type @newtype replaced with @newopt.
1281 *
1282 * @opt may be NULL, in which case a new set of options is returned
1283 * containing just @newopt.
1284 *
1285 * @newopt may be NULL, in which case the specified option type is
1286 * not copied into the new set of options.
1287 *
1288 * The new set of options is allocated from the socket option memory
1289 * buffer of @sk.
1290 */
1291 struct ipv6_txoptions *
ipv6_renew_options(struct sock * sk,struct ipv6_txoptions * opt,int newtype,struct ipv6_opt_hdr * newopt)1292 ipv6_renew_options(struct sock *sk, struct ipv6_txoptions *opt,
1293 int newtype, struct ipv6_opt_hdr *newopt)
1294 {
1295 int tot_len = 0;
1296 char *p;
1297 struct ipv6_txoptions *opt2;
1298
1299 if (opt) {
1300 if (newtype != IPV6_HOPOPTS && opt->hopopt)
1301 tot_len += CMSG_ALIGN(ipv6_optlen(opt->hopopt));
1302 if (newtype != IPV6_RTHDRDSTOPTS && opt->dst0opt)
1303 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst0opt));
1304 if (newtype != IPV6_RTHDR && opt->srcrt)
1305 tot_len += CMSG_ALIGN(ipv6_optlen(opt->srcrt));
1306 if (newtype != IPV6_DSTOPTS && opt->dst1opt)
1307 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst1opt));
1308 }
1309
1310 if (newopt)
1311 tot_len += CMSG_ALIGN(ipv6_optlen(newopt));
1312
1313 if (!tot_len)
1314 return NULL;
1315
1316 tot_len += sizeof(*opt2);
1317 opt2 = sock_kmalloc(sk, tot_len, GFP_ATOMIC);
1318 if (!opt2)
1319 return ERR_PTR(-ENOBUFS);
1320
1321 memset(opt2, 0, tot_len);
1322 refcount_set(&opt2->refcnt, 1);
1323 opt2->tot_len = tot_len;
1324 p = (char *)(opt2 + 1);
1325
1326 ipv6_renew_option(IPV6_HOPOPTS, &opt2->hopopt,
1327 (opt ? opt->hopopt : NULL),
1328 newopt, newtype, &p);
1329 ipv6_renew_option(IPV6_RTHDRDSTOPTS, &opt2->dst0opt,
1330 (opt ? opt->dst0opt : NULL),
1331 newopt, newtype, &p);
1332 ipv6_renew_option(IPV6_RTHDR,
1333 (struct ipv6_opt_hdr **)&opt2->srcrt,
1334 (opt ? (struct ipv6_opt_hdr *)opt->srcrt : NULL),
1335 newopt, newtype, &p);
1336 ipv6_renew_option(IPV6_DSTOPTS, &opt2->dst1opt,
1337 (opt ? opt->dst1opt : NULL),
1338 newopt, newtype, &p);
1339
1340 opt2->opt_nflen = (opt2->hopopt ? ipv6_optlen(opt2->hopopt) : 0) +
1341 (opt2->dst0opt ? ipv6_optlen(opt2->dst0opt) : 0) +
1342 (opt2->srcrt ? ipv6_optlen(opt2->srcrt) : 0);
1343 opt2->opt_flen = (opt2->dst1opt ? ipv6_optlen(opt2->dst1opt) : 0);
1344
1345 return opt2;
1346 }
1347
ipv6_fixup_options(struct ipv6_txoptions * opt_space,struct ipv6_txoptions * opt)1348 struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space,
1349 struct ipv6_txoptions *opt)
1350 {
1351 /*
1352 * ignore the dest before srcrt unless srcrt is being included.
1353 * --yoshfuji
1354 */
1355 if (opt && opt->dst0opt && !opt->srcrt) {
1356 if (opt_space != opt) {
1357 memcpy(opt_space, opt, sizeof(*opt_space));
1358 opt = opt_space;
1359 }
1360 opt->opt_nflen -= ipv6_optlen(opt->dst0opt);
1361 opt->dst0opt = NULL;
1362 }
1363
1364 return opt;
1365 }
1366 EXPORT_SYMBOL_GPL(ipv6_fixup_options);
1367
1368 /**
1369 * fl6_update_dst - update flowi destination address with info given
1370 * by srcrt option, if any.
1371 *
1372 * @fl6: flowi6 for which daddr is to be updated
1373 * @opt: struct ipv6_txoptions in which to look for srcrt opt
1374 * @orig: copy of original daddr address if modified
1375 *
1376 * Returns NULL if no txoptions or no srcrt, otherwise returns orig
1377 * and initial value of fl6->daddr set in orig
1378 */
fl6_update_dst(struct flowi6 * fl6,const struct ipv6_txoptions * opt,struct in6_addr * orig)1379 struct in6_addr *fl6_update_dst(struct flowi6 *fl6,
1380 const struct ipv6_txoptions *opt,
1381 struct in6_addr *orig)
1382 {
1383 if (!opt || !opt->srcrt)
1384 return NULL;
1385
1386 *orig = fl6->daddr;
1387
1388 switch (opt->srcrt->type) {
1389 case IPV6_SRCRT_TYPE_0:
1390 case IPV6_SRCRT_STRICT:
1391 case IPV6_SRCRT_TYPE_2:
1392 fl6->daddr = *((struct rt0_hdr *)opt->srcrt)->addr;
1393 break;
1394 case IPV6_SRCRT_TYPE_4:
1395 {
1396 struct ipv6_sr_hdr *srh = (struct ipv6_sr_hdr *)opt->srcrt;
1397
1398 fl6->daddr = srh->segments[srh->segments_left];
1399 break;
1400 }
1401 default:
1402 return NULL;
1403 }
1404
1405 return orig;
1406 }
1407 EXPORT_SYMBOL_GPL(fl6_update_dst);
1408
