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ipv6: Switch to using new offload infrastructure.
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / ipv6 / exthdrs.c
1 /*
2 * Extension Header handling for IPv6
3 * Linux INET6 implementation
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 * Andi Kleen <ak@muc.de>
8 * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * as published by the Free Software Foundation; either version
13 * 2 of the License, or (at your option) any later version.
14 */
15
16 /* Changes:
17 * yoshfuji : ensure not to overrun while parsing
18 * tlv options.
19 * Mitsuru KANDA @USAGI and: Remove ipv6_parse_exthdrs().
20 * YOSHIFUJI Hideaki @USAGI Register inbound extension header
21 * handlers as inet6_protocol{}.
22 */
23
24 #include <linux/errno.h>
25 #include <linux/types.h>
26 #include <linux/socket.h>
27 #include <linux/sockios.h>
28 #include <linux/net.h>
29 #include <linux/netdevice.h>
30 #include <linux/in6.h>
31 #include <linux/icmpv6.h>
32 #include <linux/slab.h>
33 #include <linux/export.h>
34
35 #include <net/dst.h>
36 #include <net/sock.h>
37 #include <net/snmp.h>
38
39 #include <net/ipv6.h>
40 #include <net/protocol.h>
41 #include <net/transp_v6.h>
42 #include <net/rawv6.h>
43 #include <net/ndisc.h>
44 #include <net/ip6_route.h>
45 #include <net/addrconf.h>
46 #if IS_ENABLED(CONFIG_IPV6_MIP6)
47 #include <net/xfrm.h>
48 #endif
49
50 #include <asm/uaccess.h>
51
52 int ipv6_find_tlv(struct sk_buff *skb, int offset, int type)
53 {
54 const unsigned char *nh = skb_network_header(skb);
55 int packet_len = skb->tail - skb->network_header;
56 struct ipv6_opt_hdr *hdr;
57 int len;
58
59 if (offset + 2 > packet_len)
60 goto bad;
61 hdr = (struct ipv6_opt_hdr *)(nh + offset);
62 len = ((hdr->hdrlen + 1) << 3);
63
64 if (offset + len > packet_len)
65 goto bad;
66
67 offset += 2;
68 len -= 2;
69
70 while (len > 0) {
71 int opttype = nh[offset];
72 int optlen;
73
74 if (opttype == type)
75 return offset;
76
77 switch (opttype) {
78 case IPV6_TLV_PAD1:
79 optlen = 1;
80 break;
81 default:
82 optlen = nh[offset + 1] + 2;
83 if (optlen > len)
84 goto bad;
85 break;
86 }
87 offset += optlen;
88 len -= optlen;
89 }
90 /* not_found */
91 bad:
92 return -1;
93 }
94 EXPORT_SYMBOL_GPL(ipv6_find_tlv);
95
96 /*
97 * Parsing tlv encoded headers.
98 *
99 * Parsing function "func" returns true, if parsing succeed
100 * and false, if it failed.
101 * It MUST NOT touch skb->h.
102 */
103
104 struct tlvtype_proc {
105 int type;
106 bool (*func)(struct sk_buff *skb, int offset);
107 };
108
109 /*********************
110 Generic functions
111 *********************/
112
113 /* An unknown option is detected, decide what to do */
114
115 static bool ip6_tlvopt_unknown(struct sk_buff *skb, int optoff)
116 {
117 switch ((skb_network_header(skb)[optoff] & 0xC0) >> 6) {
118 case 0: /* ignore */
119 return true;
120
121 case 1: /* drop packet */
122 break;
123
124 case 3: /* Send ICMP if not a multicast address and drop packet */
125 /* Actually, it is redundant check. icmp_send
126 will recheck in any case.
127 */
128 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr))
129 break;
130 case 2: /* send ICMP PARM PROB regardless and drop packet */
131 icmpv6_param_prob(skb, ICMPV6_UNK_OPTION, optoff);
132 return false;
133 }
134
135 kfree_skb(skb);
136 return false;
137 }
138
139 /* Parse tlv encoded option header (hop-by-hop or destination) */
140
141 static bool ip6_parse_tlv(const struct tlvtype_proc *procs, struct sk_buff *skb)
142 {
143 const struct tlvtype_proc *curr;
144 const unsigned char *nh = skb_network_header(skb);
145 int off = skb_network_header_len(skb);
146 int len = (skb_transport_header(skb)[1] + 1) << 3;
147 int padlen = 0;
148
149 if (skb_transport_offset(skb) + len > skb_headlen(skb))
150 goto bad;
151
152 off += 2;
153 len -= 2;
154
155 while (len > 0) {
156 int optlen = nh[off + 1] + 2;
157 int i;
158
159 switch (nh[off]) {
160 case IPV6_TLV_PAD1:
161 optlen = 1;
162 padlen++;
163 if (padlen > 7)
164 goto bad;
165 break;
166
167 case IPV6_TLV_PADN:
168 /* RFC 2460 states that the purpose of PadN is
169 * to align the containing header to multiples
170 * of 8. 7 is therefore the highest valid value.
171 * See also RFC 4942, Section 2.1.9.5.
172 */
173 padlen += optlen;
174 if (padlen > 7)
175 goto bad;
176 /* RFC 4942 recommends receiving hosts to
177 * actively check PadN payload to contain
178 * only zeroes.
179 */
180 for (i = 2; i < optlen; i++) {
181 if (nh[off + i] != 0)
182 goto bad;
183 }
184 break;
185
186 default: /* Other TLV code so scan list */
187 if (optlen > len)
188 goto bad;
189 for (curr=procs; curr->type >= 0; curr++) {
190 if (curr->type == nh[off]) {
191 /* type specific length/alignment
192 checks will be performed in the
193 func(). */
194 if (curr->func(skb, off) == false)
195 return false;
196 break;
197 }
198 }
199 if (curr->type < 0) {
200 if (ip6_tlvopt_unknown(skb, off) == 0)
201 return false;
202 }
203 padlen = 0;
204 break;
205 }
206 off += optlen;
207 len -= optlen;
208 }
209 /* This case will not be caught by above check since its padding
210 * length is smaller than 7:
211 * 1 byte NH + 1 byte Length + 6 bytes Padding
212 */
213 if ((padlen == 6) && ((off - skb_network_header_len(skb)) == 8))
214 goto bad;
215
216 if (len == 0)
217 return true;
218 bad:
219 kfree_skb(skb);
220 return false;
221 }
222
223 /*****************************
224 Destination options header.
225 *****************************/
226
227 #if IS_ENABLED(CONFIG_IPV6_MIP6)
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 struct in6_addr tmp_addr;
234 int ret;
235
236 if (opt->dsthao) {
237 LIMIT_NETDEBUG(KERN_DEBUG "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 LIMIT_NETDEBUG(
247 KERN_DEBUG "hao invalid option length = %d\n", hao->length);
248 goto discard;
249 }
250
251 if (!(ipv6_addr_type(&hao->addr) & IPV6_ADDR_UNICAST)) {
252 LIMIT_NETDEBUG(
253 KERN_DEBUG "hao is not an unicast addr: %pI6\n", &hao->addr);
254 goto discard;
255 }
256
257 ret = xfrm6_input_addr(skb, (xfrm_address_t *)&ipv6h->daddr,
258 (xfrm_address_t *)&hao->addr, IPPROTO_DSTOPTS);
259 if (unlikely(ret < 0))
260 goto discard;
261
262 if (skb_cloned(skb)) {
263 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
264 goto discard;
265
266 /* update all variable using below by copied skbuff */
267 hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) +
268 optoff);
269 ipv6h = ipv6_hdr(skb);
270 }
271
272 if (skb->ip_summed == CHECKSUM_COMPLETE)
273 skb->ip_summed = CHECKSUM_NONE;
274
275 tmp_addr = ipv6h->saddr;
276 ipv6h->saddr = hao->addr;
277 hao->addr = tmp_addr;
278
279 if (skb->tstamp.tv64 == 0)
280 __net_timestamp(skb);
281
282 return true;
283
284 discard:
285 kfree_skb(skb);
286 return false;
287 }
288 #endif
289
290 static const struct tlvtype_proc tlvprocdestopt_lst[] = {
291 #if IS_ENABLED(CONFIG_IPV6_MIP6)
292 {
293 .type = IPV6_TLV_HAO,
294 .func = ipv6_dest_hao,
295 },
296 #endif
297 {-1, NULL}
298 };
299
300 static int ipv6_destopt_rcv(struct sk_buff *skb)
301 {
302 struct inet6_skb_parm *opt = IP6CB(skb);
303 #if IS_ENABLED(CONFIG_IPV6_MIP6)
304 __u16 dstbuf;
305 #endif
306 struct dst_entry *dst = skb_dst(skb);
307
308 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
309 !pskb_may_pull(skb, (skb_transport_offset(skb) +
310 ((skb_transport_header(skb)[1] + 1) << 3)))) {
311 IP6_INC_STATS_BH(dev_net(dst->dev), ip6_dst_idev(dst),
312 IPSTATS_MIB_INHDRERRORS);
313 kfree_skb(skb);
314 return -1;
315 }
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(tlvprocdestopt_lst, skb)) {
323 skb->transport_header += (skb_transport_header(skb)[1] + 1) << 3;
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_BH(dev_net(dst->dev),
334 ip6_dst_idev(dst), IPSTATS_MIB_INHDRERRORS);
335 return -1;
336 }
337
338 /********************************
339 Routing header.
340 ********************************/
341
342 /* called with rcu_read_lock() */
343 static int ipv6_rthdr_rcv(struct sk_buff *skb)
344 {
345 struct inet6_skb_parm *opt = IP6CB(skb);
346 struct in6_addr *addr = NULL;
347 struct in6_addr daddr;
348 struct inet6_dev *idev;
349 int n, i;
350 struct ipv6_rt_hdr *hdr;
351 struct rt0_hdr *rthdr;
352 struct net *net = dev_net(skb->dev);
353 int accept_source_route = net->ipv6.devconf_all->accept_source_route;
354
355 idev = __in6_dev_get(skb->dev);
356 if (idev && accept_source_route > idev->cnf.accept_source_route)
357 accept_source_route = idev->cnf.accept_source_route;
358
359 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
360 !pskb_may_pull(skb, (skb_transport_offset(skb) +
361 ((skb_transport_header(skb)[1] + 1) << 3)))) {
362 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
363 IPSTATS_MIB_INHDRERRORS);
364 kfree_skb(skb);
365 return -1;
366 }
367
368 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb);
369
370 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) ||
371 skb->pkt_type != PACKET_HOST) {
372 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
373 IPSTATS_MIB_INADDRERRORS);
374 kfree_skb(skb);
375 return -1;
376 }
377
378 looped_back:
379 if (hdr->segments_left == 0) {
380 switch (hdr->type) {
381 #if IS_ENABLED(CONFIG_IPV6_MIP6)
382 case IPV6_SRCRT_TYPE_2:
383 /* Silently discard type 2 header unless it was
384 * processed by own
385 */
386 if (!addr) {
387 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
388 IPSTATS_MIB_INADDRERRORS);
389 kfree_skb(skb);
390 return -1;
391 }
392 break;
393 #endif
394 default:
395 break;
396 }
397
398 opt->lastopt = opt->srcrt = skb_network_header_len(skb);
399 skb->transport_header += (hdr->hdrlen + 1) << 3;
400 opt->dst0 = opt->dst1;
401 opt->dst1 = 0;
402 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb);
403 return 1;
404 }
405
406 switch (hdr->type) {
407 #if IS_ENABLED(CONFIG_IPV6_MIP6)
408 case IPV6_SRCRT_TYPE_2:
409 if (accept_source_route < 0)
410 goto unknown_rh;
411 /* Silently discard invalid RTH type 2 */
412 if (hdr->hdrlen != 2 || hdr->segments_left != 1) {
413 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
414 IPSTATS_MIB_INHDRERRORS);
415 kfree_skb(skb);
416 return -1;
417 }
418 break;
419 #endif
420 default:
421 goto unknown_rh;
422 }
423
424 /*
425 * This is the routing header forwarding algorithm from
426 * RFC 2460, page 16.
427 */
428
429 n = hdr->hdrlen >> 1;
430
431 if (hdr->segments_left > n) {
432 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
433 IPSTATS_MIB_INHDRERRORS);
434 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
435 ((&hdr->segments_left) -
436 skb_network_header(skb)));
437 return -1;
438 }
439
440 /* We are about to mangle packet header. Be careful!
441 Do not damage packets queued somewhere.
442 */
443 if (skb_cloned(skb)) {
444 /* the copy is a forwarded packet */
445 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) {
446 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
447 IPSTATS_MIB_OUTDISCARDS);
448 kfree_skb(skb);
449 return -1;
450 }
451 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb);
452 }
453
454 if (skb->ip_summed == CHECKSUM_COMPLETE)
455 skb->ip_summed = CHECKSUM_NONE;
456
457 i = n - --hdr->segments_left;
458
459 rthdr = (struct rt0_hdr *) hdr;
460 addr = rthdr->addr;
461 addr += i - 1;
462
463 switch (hdr->type) {
464 #if IS_ENABLED(CONFIG_IPV6_MIP6)
465 case IPV6_SRCRT_TYPE_2:
466 if (xfrm6_input_addr(skb, (xfrm_address_t *)addr,
467 (xfrm_address_t *)&ipv6_hdr(skb)->saddr,
468 IPPROTO_ROUTING) < 0) {
469 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
470 IPSTATS_MIB_INADDRERRORS);
471 kfree_skb(skb);
472 return -1;
473 }
474 if (!ipv6_chk_home_addr(dev_net(skb_dst(skb)->dev), addr)) {
475 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
476 IPSTATS_MIB_INADDRERRORS);
477 kfree_skb(skb);
478 return -1;
479 }
480 break;
481 #endif
482 default:
483 break;
484 }
485
486 if (ipv6_addr_is_multicast(addr)) {
487 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
488 IPSTATS_MIB_INADDRERRORS);
489 kfree_skb(skb);
490 return -1;
491 }
492
493 daddr = *addr;
494 *addr = ipv6_hdr(skb)->daddr;
495 ipv6_hdr(skb)->daddr = daddr;
496
497 skb_dst_drop(skb);
498 ip6_route_input(skb);
499 if (skb_dst(skb)->error) {
500 skb_push(skb, skb->data - skb_network_header(skb));
501 dst_input(skb);
502 return -1;
503 }
504
505 if (skb_dst(skb)->dev->flags&IFF_LOOPBACK) {
506 if (ipv6_hdr(skb)->hop_limit <= 1) {
507 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
508 IPSTATS_MIB_INHDRERRORS);
509 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
510 0);
511 kfree_skb(skb);
512 return -1;
513 }
514 ipv6_hdr(skb)->hop_limit--;
515 goto looped_back;
516 }
517
518 skb_push(skb, skb->data - skb_network_header(skb));
519 dst_input(skb);
520 return -1;
521
522 unknown_rh:
523 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INHDRERRORS);
524 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
525 (&hdr->type) - skb_network_header(skb));
526 return -1;
527 }
528
529 static const struct inet6_protocol rthdr_protocol = {
530 .handler = ipv6_rthdr_rcv,
531 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_GSO_EXTHDR,
532 };
533
534 static const struct net_offload rthdr_offload = {
535 .flags = INET6_PROTO_GSO_EXTHDR,
536 };
537
538 static const struct inet6_protocol destopt_protocol = {
539 .handler = ipv6_destopt_rcv,
540 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_GSO_EXTHDR,
541 };
542
543 static const struct net_offload dstopt_offload = {
544 .flags = INET6_PROTO_GSO_EXTHDR,
545 };
546
547 static const struct inet6_protocol nodata_protocol = {
548 .handler = dst_discard,
549 .flags = INET6_PROTO_NOPOLICY,
550 };
551
552 static int ipv6_exthdrs_offload_init(void)
553 {
554 int ret;
555
556 ret = inet6_add_offload(&rthdr_offload, IPPROTO_ROUTING);
557 if (!ret)
558 goto out;
559
560 ret = inet6_add_offload(&dstopt_offload, IPPROTO_DSTOPTS);
561 if (!ret)
562 goto out_rt;
563
564 out:
565 return ret;
566
567 out_rt:
568 inet_del_offload(&rthdr_offload, IPPROTO_ROUTING);
569 goto out;
570 }
571
572 static void ipv6_exthdrs_offload_exit(void)
573 {
574 inet_del_offload(&rthdr_offload, IPPROTO_ROUTING);
575 inet_del_offload(&rthdr_offload, IPPROTO_DSTOPTS);
576 }
577
578 int __init ipv6_exthdrs_init(void)
579 {
580 int ret;
581
582 ret = ipv6_exthdrs_offload_init();
583 if (ret)
584 goto out;
585
586 ret = inet6_add_protocol(&rthdr_protocol, IPPROTO_ROUTING);
587 if (ret)
588 goto out_offload;
589
590 ret = inet6_add_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
591 if (ret)
592 goto out_rthdr;
593
594 ret = inet6_add_protocol(&nodata_protocol, IPPROTO_NONE);
595 if (ret)
596 goto out_destopt;
597
598 out:
599 return ret;
600 out_destopt:
601 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
602 out_rthdr:
603 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING);
604 out_offload:
605 ipv6_exthdrs_offload_exit();
606 goto out;
607 };
608
609 void ipv6_exthdrs_exit(void)
610 {
611 inet6_del_protocol(&nodata_protocol, IPPROTO_NONE);
612 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
613 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING);
614 }
615
616 /**********************************
617 Hop-by-hop options.
618 **********************************/
619
620 /*
621 * Note: we cannot rely on skb_dst(skb) before we assign it in ip6_route_input().
622 */
623 static inline struct inet6_dev *ipv6_skb_idev(struct sk_buff *skb)
624 {
625 return skb_dst(skb) ? ip6_dst_idev(skb_dst(skb)) : __in6_dev_get(skb->dev);
626 }
627
628 static inline struct net *ipv6_skb_net(struct sk_buff *skb)
629 {
630 return skb_dst(skb) ? dev_net(skb_dst(skb)->dev) : dev_net(skb->dev);
631 }
632
633 /* Router Alert as of RFC 2711 */
634
635 static bool ipv6_hop_ra(struct sk_buff *skb, int optoff)
636 {
637 const unsigned char *nh = skb_network_header(skb);
638
639 if (nh[optoff + 1] == 2) {
640 IP6CB(skb)->ra = optoff;
641 return true;
642 }
643 LIMIT_NETDEBUG(KERN_DEBUG "ipv6_hop_ra: wrong RA length %d\n",
644 nh[optoff + 1]);
645 kfree_skb(skb);
646 return false;
647 }
648
649 /* Jumbo payload */
650
651 static bool ipv6_hop_jumbo(struct sk_buff *skb, int optoff)
652 {
653 const unsigned char *nh = skb_network_header(skb);
654 struct net *net = ipv6_skb_net(skb);
655 u32 pkt_len;
656
657 if (nh[optoff + 1] != 4 || (optoff & 3) != 2) {
658 LIMIT_NETDEBUG(KERN_DEBUG "ipv6_hop_jumbo: wrong jumbo opt length/alignment %d\n",
659 nh[optoff+1]);
660 IP6_INC_STATS_BH(net, ipv6_skb_idev(skb),
661 IPSTATS_MIB_INHDRERRORS);
662 goto drop;
663 }
664
665 pkt_len = ntohl(*(__be32 *)(nh + optoff + 2));
666 if (pkt_len <= IPV6_MAXPLEN) {
667 IP6_INC_STATS_BH(net, ipv6_skb_idev(skb),
668 IPSTATS_MIB_INHDRERRORS);
669 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff+2);
670 return false;
671 }
672 if (ipv6_hdr(skb)->payload_len) {
673 IP6_INC_STATS_BH(net, ipv6_skb_idev(skb),
674 IPSTATS_MIB_INHDRERRORS);
675 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff);
676 return false;
677 }
678
679 if (pkt_len > skb->len - sizeof(struct ipv6hdr)) {
680 IP6_INC_STATS_BH(net, ipv6_skb_idev(skb),
681 IPSTATS_MIB_INTRUNCATEDPKTS);
682 goto drop;
683 }
684
685 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr)))
686 goto drop;
687
688 return true;
689
690 drop:
691 kfree_skb(skb);
692 return false;
693 }
694
695 static const struct tlvtype_proc tlvprochopopt_lst[] = {
696 {
697 .type = IPV6_TLV_ROUTERALERT,
698 .func = ipv6_hop_ra,
699 },
700 {
701 .type = IPV6_TLV_JUMBO,
702 .func = ipv6_hop_jumbo,
703 },
704 { -1, }
705 };
706
707 int ipv6_parse_hopopts(struct sk_buff *skb)
708 {
709 struct inet6_skb_parm *opt = IP6CB(skb);
710
711 /*
712 * skb_network_header(skb) is equal to skb->data, and
713 * skb_network_header_len(skb) is always equal to
714 * sizeof(struct ipv6hdr) by definition of
715 * hop-by-hop options.
716 */
717 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + 8) ||
718 !pskb_may_pull(skb, (sizeof(struct ipv6hdr) +
719 ((skb_transport_header(skb)[1] + 1) << 3)))) {
720 kfree_skb(skb);
721 return -1;
722 }
723
724 opt->hop = sizeof(struct ipv6hdr);
725 if (ip6_parse_tlv(tlvprochopopt_lst, skb)) {
726 skb->transport_header += (skb_transport_header(skb)[1] + 1) << 3;
727 opt = IP6CB(skb);
728 opt->nhoff = sizeof(struct ipv6hdr);
729 return 1;
730 }
731 return -1;
732 }
733
734 /*
735 * Creating outbound headers.
736 *
737 * "build" functions work when skb is filled from head to tail (datagram)
738 * "push" functions work when headers are added from tail to head (tcp)
739 *
740 * In both cases we assume, that caller reserved enough room
741 * for headers.
742 */
743
744 static void ipv6_push_rthdr(struct sk_buff *skb, u8 *proto,
745 struct ipv6_rt_hdr *opt,
746 struct in6_addr **addr_p)
747 {
748 struct rt0_hdr *phdr, *ihdr;
749 int hops;
750
751 ihdr = (struct rt0_hdr *) opt;
752
753 phdr = (struct rt0_hdr *) skb_push(skb, (ihdr->rt_hdr.hdrlen + 1) << 3);
754 memcpy(phdr, ihdr, sizeof(struct rt0_hdr));
755
756 hops = ihdr->rt_hdr.hdrlen >> 1;
757
758 if (hops > 1)
759 memcpy(phdr->addr, ihdr->addr + 1,
760 (hops - 1) * sizeof(struct in6_addr));
761
762 phdr->addr[hops - 1] = **addr_p;
763 *addr_p = ihdr->addr;
764
765 phdr->rt_hdr.nexthdr = *proto;
766 *proto = NEXTHDR_ROUTING;
767 }
768
769 static void ipv6_push_exthdr(struct sk_buff *skb, u8 *proto, u8 type, struct ipv6_opt_hdr *opt)
770 {
771 struct ipv6_opt_hdr *h = (struct ipv6_opt_hdr *)skb_push(skb, ipv6_optlen(opt));
772
773 memcpy(h, opt, ipv6_optlen(opt));
774 h->nexthdr = *proto;
775 *proto = type;
776 }
777
778 void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
779 u8 *proto,
780 struct in6_addr **daddr)
781 {
782 if (opt->srcrt) {
783 ipv6_push_rthdr(skb, proto, opt->srcrt, daddr);
784 /*
785 * IPV6_RTHDRDSTOPTS is ignored
786 * unless IPV6_RTHDR is set (RFC3542).
787 */
788 if (opt->dst0opt)
789 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst0opt);
790 }
791 if (opt->hopopt)
792 ipv6_push_exthdr(skb, proto, NEXTHDR_HOP, opt->hopopt);
793 }
794 EXPORT_SYMBOL(ipv6_push_nfrag_opts);
795
796 void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, u8 *proto)
797 {
798 if (opt->dst1opt)
799 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst1opt);
800 }
801
802 struct ipv6_txoptions *
803 ipv6_dup_options(struct sock *sk, struct ipv6_txoptions *opt)
804 {
805 struct ipv6_txoptions *opt2;
806
807 opt2 = sock_kmalloc(sk, opt->tot_len, GFP_ATOMIC);
808 if (opt2) {
809 long dif = (char *)opt2 - (char *)opt;
810 memcpy(opt2, opt, opt->tot_len);
811 if (opt2->hopopt)
812 *((char **)&opt2->hopopt) += dif;
813 if (opt2->dst0opt)
814 *((char **)&opt2->dst0opt) += dif;
815 if (opt2->dst1opt)
816 *((char **)&opt2->dst1opt) += dif;
817 if (opt2->srcrt)
818 *((char **)&opt2->srcrt) += dif;
819 }
820 return opt2;
821 }
822 EXPORT_SYMBOL_GPL(ipv6_dup_options);
823
824 static int ipv6_renew_option(void *ohdr,
825 struct ipv6_opt_hdr __user *newopt, int newoptlen,
826 int inherit,
827 struct ipv6_opt_hdr **hdr,
828 char **p)
829 {
830 if (inherit) {
831 if (ohdr) {
832 memcpy(*p, ohdr, ipv6_optlen((struct ipv6_opt_hdr *)ohdr));
833 *hdr = (struct ipv6_opt_hdr *)*p;
834 *p += CMSG_ALIGN(ipv6_optlen(*hdr));
835 }
836 } else {
837 if (newopt) {
838 if (copy_from_user(*p, newopt, newoptlen))
839 return -EFAULT;
840 *hdr = (struct ipv6_opt_hdr *)*p;
841 if (ipv6_optlen(*hdr) > newoptlen)
842 return -EINVAL;
843 *p += CMSG_ALIGN(newoptlen);
844 }
845 }
846 return 0;
847 }
848
849 struct ipv6_txoptions *
850 ipv6_renew_options(struct sock *sk, struct ipv6_txoptions *opt,
851 int newtype,
852 struct ipv6_opt_hdr __user *newopt, int newoptlen)
853 {
854 int tot_len = 0;
855 char *p;
856 struct ipv6_txoptions *opt2;
857 int err;
858
859 if (opt) {
860 if (newtype != IPV6_HOPOPTS && opt->hopopt)
861 tot_len += CMSG_ALIGN(ipv6_optlen(opt->hopopt));
862 if (newtype != IPV6_RTHDRDSTOPTS && opt->dst0opt)
863 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst0opt));
864 if (newtype != IPV6_RTHDR && opt->srcrt)
865 tot_len += CMSG_ALIGN(ipv6_optlen(opt->srcrt));
866 if (newtype != IPV6_DSTOPTS && opt->dst1opt)
867 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst1opt));
868 }
869
870 if (newopt && newoptlen)
871 tot_len += CMSG_ALIGN(newoptlen);
872
873 if (!tot_len)
874 return NULL;
875
876 tot_len += sizeof(*opt2);
877 opt2 = sock_kmalloc(sk, tot_len, GFP_ATOMIC);
878 if (!opt2)
879 return ERR_PTR(-ENOBUFS);
880
881 memset(opt2, 0, tot_len);
882
883 opt2->tot_len = tot_len;
884 p = (char *)(opt2 + 1);
885
886 err = ipv6_renew_option(opt ? opt->hopopt : NULL, newopt, newoptlen,
887 newtype != IPV6_HOPOPTS,
888 &opt2->hopopt, &p);
889 if (err)
890 goto out;
891
892 err = ipv6_renew_option(opt ? opt->dst0opt : NULL, newopt, newoptlen,
893 newtype != IPV6_RTHDRDSTOPTS,
894 &opt2->dst0opt, &p);
895 if (err)
896 goto out;
897
898 err = ipv6_renew_option(opt ? opt->srcrt : NULL, newopt, newoptlen,
899 newtype != IPV6_RTHDR,
900 (struct ipv6_opt_hdr **)&opt2->srcrt, &p);
901 if (err)
902 goto out;
903
904 err = ipv6_renew_option(opt ? opt->dst1opt : NULL, newopt, newoptlen,
905 newtype != IPV6_DSTOPTS,
906 &opt2->dst1opt, &p);
907 if (err)
908 goto out;
909
910 opt2->opt_nflen = (opt2->hopopt ? ipv6_optlen(opt2->hopopt) : 0) +
911 (opt2->dst0opt ? ipv6_optlen(opt2->dst0opt) : 0) +
912 (opt2->srcrt ? ipv6_optlen(opt2->srcrt) : 0);
913 opt2->opt_flen = (opt2->dst1opt ? ipv6_optlen(opt2->dst1opt) : 0);
914
915 return opt2;
916 out:
917 sock_kfree_s(sk, opt2, opt2->tot_len);
918 return ERR_PTR(err);
919 }
920
921 struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space,
922 struct ipv6_txoptions *opt)
923 {
924 /*
925 * ignore the dest before srcrt unless srcrt is being included.
926 * --yoshfuji
927 */
928 if (opt && opt->dst0opt && !opt->srcrt) {
929 if (opt_space != opt) {
930 memcpy(opt_space, opt, sizeof(*opt_space));
931 opt = opt_space;
932 }
933 opt->opt_nflen -= ipv6_optlen(opt->dst0opt);
934 opt->dst0opt = NULL;
935 }
936
937 return opt;
938 }
939 EXPORT_SYMBOL_GPL(ipv6_fixup_options);
940
941 /**
942 * fl6_update_dst - update flowi destination address with info given
943 * by srcrt option, if any.
944 *
945 * @fl6: flowi6 for which daddr is to be updated
946 * @opt: struct ipv6_txoptions in which to look for srcrt opt
947 * @orig: copy of original daddr address if modified
948 *
949 * Returns NULL if no txoptions or no srcrt, otherwise returns orig
950 * and initial value of fl6->daddr set in orig
951 */
952 struct in6_addr *fl6_update_dst(struct flowi6 *fl6,
953 const struct ipv6_txoptions *opt,
954 struct in6_addr *orig)
955 {
956 if (!opt || !opt->srcrt)
957 return NULL;
958
959 *orig = fl6->daddr;
960 fl6->daddr = *((struct rt0_hdr *)opt->srcrt)->addr;
961 return orig;
962 }
963 EXPORT_SYMBOL_GPL(fl6_update_dst);
kernel source for telekom puls (alcatel/mediatek)