2
* Extension Header handling for IPv6
3
* Linux INET6 implementation
6
* Pedro Roque <roque@di.fc.ul.pt>
7
* Andi Kleen <ak@muc.de>
8
* Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
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.
17
* yoshfuji : ensure not to overrun while parsing
19
* Mitsuru KANDA @USAGI and: Remove ipv6_parse_exthdrs().
20
* YOSHIFUJI Hideaki @USAGI Register inbound extension header
21
* handlers as inet6_protocol{}.
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>
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 defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
50
#include <asm/uaccess.h>
52
int ipv6_find_tlv(struct sk_buff *skb, int offset, int type)
54
const unsigned char *nh = skb_network_header(skb);
55
int packet_len = skb->tail - skb->network_header;
56
struct ipv6_opt_hdr *hdr;
59
if (offset + 2 > packet_len)
61
hdr = (struct ipv6_opt_hdr *)(nh + offset);
62
len = ((hdr->hdrlen + 1) << 3);
64
if (offset + len > packet_len)
71
int opttype = nh[offset];
82
optlen = nh[offset + 1] + 2;
94
EXPORT_SYMBOL_GPL(ipv6_find_tlv);
97
* Parsing tlv encoded headers.
99
* Parsing function "func" returns 1, if parsing succeed
100
* and 0, if it failed.
101
* It MUST NOT touch skb->h.
104
struct tlvtype_proc {
106
int (*func)(struct sk_buff *skb, int offset);
109
/*********************
111
*********************/
113
/* An unknown option is detected, decide what to do */
115
static int ip6_tlvopt_unknown(struct sk_buff *skb, int optoff)
117
switch ((skb_network_header(skb)[optoff] & 0xC0) >> 6) {
121
case 1: /* drop packet */
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.
128
if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr))
130
case 2: /* send ICMP PARM PROB regardless and drop packet */
131
icmpv6_param_prob(skb, ICMPV6_UNK_OPTION, optoff);
139
/* Parse tlv encoded option header (hop-by-hop or destination) */
141
static int ip6_parse_tlv(struct tlvtype_proc *procs, struct sk_buff *skb)
143
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;
148
if (skb_transport_offset(skb) + len > skb_headlen(skb))
155
int optlen = nh[off + 1] + 2;
165
default: /* Other TLV code so scan list */
168
for (curr=procs; curr->type >= 0; curr++) {
169
if (curr->type == nh[off]) {
170
/* type specific length/alignment
171
checks will be performed in the
173
if (curr->func(skb, off) == 0)
178
if (curr->type < 0) {
179
if (ip6_tlvopt_unknown(skb, off) == 0)
194
/*****************************
195
Destination options header.
196
*****************************/
198
#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
199
static int ipv6_dest_hao(struct sk_buff *skb, int optoff)
201
struct ipv6_destopt_hao *hao;
202
struct inet6_skb_parm *opt = IP6CB(skb);
203
struct ipv6hdr *ipv6h = ipv6_hdr(skb);
204
struct in6_addr tmp_addr;
208
LIMIT_NETDEBUG(KERN_DEBUG "hao duplicated\n");
211
opt->dsthao = opt->dst1;
214
hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) + optoff);
216
if (hao->length != 16) {
218
KERN_DEBUG "hao invalid option length = %d\n", hao->length);
222
if (!(ipv6_addr_type(&hao->addr) & IPV6_ADDR_UNICAST)) {
224
KERN_DEBUG "hao is not an unicast addr: %pI6\n", &hao->addr);
228
ret = xfrm6_input_addr(skb, (xfrm_address_t *)&ipv6h->daddr,
229
(xfrm_address_t *)&hao->addr, IPPROTO_DSTOPTS);
230
if (unlikely(ret < 0))
233
if (skb_cloned(skb)) {
234
if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
237
/* update all variable using below by copied skbuff */
238
hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) +
240
ipv6h = ipv6_hdr(skb);
243
if (skb->ip_summed == CHECKSUM_COMPLETE)
244
skb->ip_summed = CHECKSUM_NONE;
246
ipv6_addr_copy(&tmp_addr, &ipv6h->saddr);
247
ipv6_addr_copy(&ipv6h->saddr, &hao->addr);
248
ipv6_addr_copy(&hao->addr, &tmp_addr);
250
if (skb->tstamp.tv64 == 0)
251
__net_timestamp(skb);
261
static struct tlvtype_proc tlvprocdestopt_lst[] = {
262
#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
264
.type = IPV6_TLV_HAO,
265
.func = ipv6_dest_hao,
271
static int ipv6_destopt_rcv(struct sk_buff *skb)
273
struct inet6_skb_parm *opt = IP6CB(skb);
274
#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
277
struct dst_entry *dst = skb_dst(skb);
279
if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
280
!pskb_may_pull(skb, (skb_transport_offset(skb) +
281
((skb_transport_header(skb)[1] + 1) << 3)))) {
282
IP6_INC_STATS_BH(dev_net(dst->dev), ip6_dst_idev(dst),
283
IPSTATS_MIB_INHDRERRORS);
288
opt->lastopt = opt->dst1 = skb_network_header_len(skb);
289
#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
293
if (ip6_parse_tlv(tlvprocdestopt_lst, skb)) {
294
skb->transport_header += (skb_transport_header(skb)[1] + 1) << 3;
296
#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
299
opt->nhoff = opt->dst1;
304
IP6_INC_STATS_BH(dev_net(dst->dev),
305
ip6_dst_idev(dst), IPSTATS_MIB_INHDRERRORS);
309
/********************************
311
********************************/
313
/* called with rcu_read_lock() */
314
static int ipv6_rthdr_rcv(struct sk_buff *skb)
316
struct inet6_skb_parm *opt = IP6CB(skb);
317
struct in6_addr *addr = NULL;
318
struct in6_addr daddr;
319
struct inet6_dev *idev;
321
struct ipv6_rt_hdr *hdr;
322
struct rt0_hdr *rthdr;
323
struct net *net = dev_net(skb->dev);
324
int accept_source_route = net->ipv6.devconf_all->accept_source_route;
326
idev = __in6_dev_get(skb->dev);
327
if (idev && accept_source_route > idev->cnf.accept_source_route)
328
accept_source_route = idev->cnf.accept_source_route;
330
if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
331
!pskb_may_pull(skb, (skb_transport_offset(skb) +
332
((skb_transport_header(skb)[1] + 1) << 3)))) {
333
IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
334
IPSTATS_MIB_INHDRERRORS);
339
hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb);
341
if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) ||
342
skb->pkt_type != PACKET_HOST) {
343
IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
344
IPSTATS_MIB_INADDRERRORS);
350
if (hdr->segments_left == 0) {
352
#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
353
case IPV6_SRCRT_TYPE_2:
354
/* Silently discard type 2 header unless it was
358
IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
359
IPSTATS_MIB_INADDRERRORS);
369
opt->lastopt = opt->srcrt = skb_network_header_len(skb);
370
skb->transport_header += (hdr->hdrlen + 1) << 3;
371
opt->dst0 = opt->dst1;
373
opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb);
378
#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
379
case IPV6_SRCRT_TYPE_2:
380
if (accept_source_route < 0)
382
/* Silently discard invalid RTH type 2 */
383
if (hdr->hdrlen != 2 || hdr->segments_left != 1) {
384
IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
385
IPSTATS_MIB_INHDRERRORS);
396
* This is the routing header forwarding algorithm from
400
n = hdr->hdrlen >> 1;
402
if (hdr->segments_left > n) {
403
IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
404
IPSTATS_MIB_INHDRERRORS);
405
icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
406
((&hdr->segments_left) -
407
skb_network_header(skb)));
411
/* We are about to mangle packet header. Be careful!
412
Do not damage packets queued somewhere.
414
if (skb_cloned(skb)) {
415
/* the copy is a forwarded packet */
416
if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) {
417
IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
418
IPSTATS_MIB_OUTDISCARDS);
422
hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb);
425
if (skb->ip_summed == CHECKSUM_COMPLETE)
426
skb->ip_summed = CHECKSUM_NONE;
428
i = n - --hdr->segments_left;
430
rthdr = (struct rt0_hdr *) hdr;
435
#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
436
case IPV6_SRCRT_TYPE_2:
437
if (xfrm6_input_addr(skb, (xfrm_address_t *)addr,
438
(xfrm_address_t *)&ipv6_hdr(skb)->saddr,
439
IPPROTO_ROUTING) < 0) {
440
IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
441
IPSTATS_MIB_INADDRERRORS);
445
if (!ipv6_chk_home_addr(dev_net(skb_dst(skb)->dev), addr)) {
446
IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
447
IPSTATS_MIB_INADDRERRORS);
457
if (ipv6_addr_is_multicast(addr)) {
458
IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
459
IPSTATS_MIB_INADDRERRORS);
464
ipv6_addr_copy(&daddr, addr);
465
ipv6_addr_copy(addr, &ipv6_hdr(skb)->daddr);
466
ipv6_addr_copy(&ipv6_hdr(skb)->daddr, &daddr);
469
ip6_route_input(skb);
470
if (skb_dst(skb)->error) {
471
skb_push(skb, skb->data - skb_network_header(skb));
476
if (skb_dst(skb)->dev->flags&IFF_LOOPBACK) {
477
if (ipv6_hdr(skb)->hop_limit <= 1) {
478
IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
479
IPSTATS_MIB_INHDRERRORS);
480
icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
485
ipv6_hdr(skb)->hop_limit--;
489
skb_push(skb, skb->data - skb_network_header(skb));
494
IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INHDRERRORS);
495
icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
496
(&hdr->type) - skb_network_header(skb));
500
static const struct inet6_protocol rthdr_protocol = {
501
.handler = ipv6_rthdr_rcv,
502
.flags = INET6_PROTO_NOPOLICY | INET6_PROTO_GSO_EXTHDR,
505
static const struct inet6_protocol destopt_protocol = {
506
.handler = ipv6_destopt_rcv,
507
.flags = INET6_PROTO_NOPOLICY | INET6_PROTO_GSO_EXTHDR,
510
static const struct inet6_protocol nodata_protocol = {
511
.handler = dst_discard,
512
.flags = INET6_PROTO_NOPOLICY,
515
int __init ipv6_exthdrs_init(void)
519
ret = inet6_add_protocol(&rthdr_protocol, IPPROTO_ROUTING);
523
ret = inet6_add_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
527
ret = inet6_add_protocol(&nodata_protocol, IPPROTO_NONE);
534
inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING);
536
inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
540
void ipv6_exthdrs_exit(void)
542
inet6_del_protocol(&nodata_protocol, IPPROTO_NONE);
543
inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
544
inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING);
547
/**********************************
549
**********************************/
552
* Note: we cannot rely on skb_dst(skb) before we assign it in ip6_route_input().
554
static inline struct inet6_dev *ipv6_skb_idev(struct sk_buff *skb)
556
return skb_dst(skb) ? ip6_dst_idev(skb_dst(skb)) : __in6_dev_get(skb->dev);
559
static inline struct net *ipv6_skb_net(struct sk_buff *skb)
561
return skb_dst(skb) ? dev_net(skb_dst(skb)->dev) : dev_net(skb->dev);
564
/* Router Alert as of RFC 2711 */
566
static int ipv6_hop_ra(struct sk_buff *skb, int optoff)
568
const unsigned char *nh = skb_network_header(skb);
570
if (nh[optoff + 1] == 2) {
571
IP6CB(skb)->ra = optoff;
574
LIMIT_NETDEBUG(KERN_DEBUG "ipv6_hop_ra: wrong RA length %d\n",
582
static int ipv6_hop_jumbo(struct sk_buff *skb, int optoff)
584
const unsigned char *nh = skb_network_header(skb);
585
struct net *net = ipv6_skb_net(skb);
588
if (nh[optoff + 1] != 4 || (optoff & 3) != 2) {
589
LIMIT_NETDEBUG(KERN_DEBUG "ipv6_hop_jumbo: wrong jumbo opt length/alignment %d\n",
591
IP6_INC_STATS_BH(net, ipv6_skb_idev(skb),
592
IPSTATS_MIB_INHDRERRORS);
596
pkt_len = ntohl(*(__be32 *)(nh + optoff + 2));
597
if (pkt_len <= IPV6_MAXPLEN) {
598
IP6_INC_STATS_BH(net, ipv6_skb_idev(skb),
599
IPSTATS_MIB_INHDRERRORS);
600
icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff+2);
603
if (ipv6_hdr(skb)->payload_len) {
604
IP6_INC_STATS_BH(net, ipv6_skb_idev(skb),
605
IPSTATS_MIB_INHDRERRORS);
606
icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff);
610
if (pkt_len > skb->len - sizeof(struct ipv6hdr)) {
611
IP6_INC_STATS_BH(net, ipv6_skb_idev(skb),
612
IPSTATS_MIB_INTRUNCATEDPKTS);
616
if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr)))
626
static struct tlvtype_proc tlvprochopopt_lst[] = {
628
.type = IPV6_TLV_ROUTERALERT,
632
.type = IPV6_TLV_JUMBO,
633
.func = ipv6_hop_jumbo,
638
int ipv6_parse_hopopts(struct sk_buff *skb)
640
struct inet6_skb_parm *opt = IP6CB(skb);
643
* skb_network_header(skb) is equal to skb->data, and
644
* skb_network_header_len(skb) is always equal to
645
* sizeof(struct ipv6hdr) by definition of
646
* hop-by-hop options.
648
if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + 8) ||
649
!pskb_may_pull(skb, (sizeof(struct ipv6hdr) +
650
((skb_transport_header(skb)[1] + 1) << 3)))) {
655
opt->hop = sizeof(struct ipv6hdr);
656
if (ip6_parse_tlv(tlvprochopopt_lst, skb)) {
657
skb->transport_header += (skb_transport_header(skb)[1] + 1) << 3;
659
opt->nhoff = sizeof(struct ipv6hdr);
666
* Creating outbound headers.
668
* "build" functions work when skb is filled from head to tail (datagram)
669
* "push" functions work when headers are added from tail to head (tcp)
671
* In both cases we assume, that caller reserved enough room
675
static void ipv6_push_rthdr(struct sk_buff *skb, u8 *proto,
676
struct ipv6_rt_hdr *opt,
677
struct in6_addr **addr_p)
679
struct rt0_hdr *phdr, *ihdr;
682
ihdr = (struct rt0_hdr *) opt;
684
phdr = (struct rt0_hdr *) skb_push(skb, (ihdr->rt_hdr.hdrlen + 1) << 3);
685
memcpy(phdr, ihdr, sizeof(struct rt0_hdr));
687
hops = ihdr->rt_hdr.hdrlen >> 1;
690
memcpy(phdr->addr, ihdr->addr + 1,
691
(hops - 1) * sizeof(struct in6_addr));
693
ipv6_addr_copy(phdr->addr + (hops - 1), *addr_p);
694
*addr_p = ihdr->addr;
696
phdr->rt_hdr.nexthdr = *proto;
697
*proto = NEXTHDR_ROUTING;
700
static void ipv6_push_exthdr(struct sk_buff *skb, u8 *proto, u8 type, struct ipv6_opt_hdr *opt)
702
struct ipv6_opt_hdr *h = (struct ipv6_opt_hdr *)skb_push(skb, ipv6_optlen(opt));
704
memcpy(h, opt, ipv6_optlen(opt));
709
void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
711
struct in6_addr **daddr)
714
ipv6_push_rthdr(skb, proto, opt->srcrt, daddr);
716
* IPV6_RTHDRDSTOPTS is ignored
717
* unless IPV6_RTHDR is set (RFC3542).
720
ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst0opt);
723
ipv6_push_exthdr(skb, proto, NEXTHDR_HOP, opt->hopopt);
726
EXPORT_SYMBOL(ipv6_push_nfrag_opts);
728
void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, u8 *proto)
731
ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst1opt);
734
struct ipv6_txoptions *
735
ipv6_dup_options(struct sock *sk, struct ipv6_txoptions *opt)
737
struct ipv6_txoptions *opt2;
739
opt2 = sock_kmalloc(sk, opt->tot_len, GFP_ATOMIC);
741
long dif = (char*)opt2 - (char*)opt;
742
memcpy(opt2, opt, opt->tot_len);
744
*((char**)&opt2->hopopt) += dif;
746
*((char**)&opt2->dst0opt) += dif;
748
*((char**)&opt2->dst1opt) += dif;
750
*((char**)&opt2->srcrt) += dif;
755
EXPORT_SYMBOL_GPL(ipv6_dup_options);
757
static int ipv6_renew_option(void *ohdr,
758
struct ipv6_opt_hdr __user *newopt, int newoptlen,
760
struct ipv6_opt_hdr **hdr,
765
memcpy(*p, ohdr, ipv6_optlen((struct ipv6_opt_hdr *)ohdr));
766
*hdr = (struct ipv6_opt_hdr *)*p;
767
*p += CMSG_ALIGN(ipv6_optlen(*(struct ipv6_opt_hdr **)hdr));
771
if (copy_from_user(*p, newopt, newoptlen))
773
*hdr = (struct ipv6_opt_hdr *)*p;
774
if (ipv6_optlen(*(struct ipv6_opt_hdr **)hdr) > newoptlen)
776
*p += CMSG_ALIGN(newoptlen);
782
struct ipv6_txoptions *
783
ipv6_renew_options(struct sock *sk, struct ipv6_txoptions *opt,
785
struct ipv6_opt_hdr __user *newopt, int newoptlen)
789
struct ipv6_txoptions *opt2;
793
if (newtype != IPV6_HOPOPTS && opt->hopopt)
794
tot_len += CMSG_ALIGN(ipv6_optlen(opt->hopopt));
795
if (newtype != IPV6_RTHDRDSTOPTS && opt->dst0opt)
796
tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst0opt));
797
if (newtype != IPV6_RTHDR && opt->srcrt)
798
tot_len += CMSG_ALIGN(ipv6_optlen(opt->srcrt));
799
if (newtype != IPV6_DSTOPTS && opt->dst1opt)
800
tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst1opt));
803
if (newopt && newoptlen)
804
tot_len += CMSG_ALIGN(newoptlen);
809
tot_len += sizeof(*opt2);
810
opt2 = sock_kmalloc(sk, tot_len, GFP_ATOMIC);
812
return ERR_PTR(-ENOBUFS);
814
memset(opt2, 0, tot_len);
816
opt2->tot_len = tot_len;
817
p = (char *)(opt2 + 1);
819
err = ipv6_renew_option(opt ? opt->hopopt : NULL, newopt, newoptlen,
820
newtype != IPV6_HOPOPTS,
825
err = ipv6_renew_option(opt ? opt->dst0opt : NULL, newopt, newoptlen,
826
newtype != IPV6_RTHDRDSTOPTS,
831
err = ipv6_renew_option(opt ? opt->srcrt : NULL, newopt, newoptlen,
832
newtype != IPV6_RTHDR,
833
(struct ipv6_opt_hdr **)&opt2->srcrt, &p);
837
err = ipv6_renew_option(opt ? opt->dst1opt : NULL, newopt, newoptlen,
838
newtype != IPV6_DSTOPTS,
843
opt2->opt_nflen = (opt2->hopopt ? ipv6_optlen(opt2->hopopt) : 0) +
844
(opt2->dst0opt ? ipv6_optlen(opt2->dst0opt) : 0) +
845
(opt2->srcrt ? ipv6_optlen(opt2->srcrt) : 0);
846
opt2->opt_flen = (opt2->dst1opt ? ipv6_optlen(opt2->dst1opt) : 0);
850
sock_kfree_s(sk, opt2, opt2->tot_len);
854
struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space,
855
struct ipv6_txoptions *opt)
858
* ignore the dest before srcrt unless srcrt is being included.
861
if (opt && opt->dst0opt && !opt->srcrt) {
862
if (opt_space != opt) {
863
memcpy(opt_space, opt, sizeof(*opt_space));
866
opt->opt_nflen -= ipv6_optlen(opt->dst0opt);
874
* fl6_update_dst - update flowi destination address with info given
875
* by srcrt option, if any.
877
* @fl6: flowi6 for which daddr is to be updated
878
* @opt: struct ipv6_txoptions in which to look for srcrt opt
879
* @orig: copy of original daddr address if modified
881
* Returns NULL if no txoptions or no srcrt, otherwise returns orig
882
* and initial value of fl6->daddr set in orig
884
struct in6_addr *fl6_update_dst(struct flowi6 *fl6,
885
const struct ipv6_txoptions *opt,
886
struct in6_addr *orig)
888
if (!opt || !opt->srcrt)
891
ipv6_addr_copy(orig, &fl6->daddr);
892
ipv6_addr_copy(&fl6->daddr, ((struct rt0_hdr *)opt->srcrt)->addr);
896
EXPORT_SYMBOL_GPL(fl6_update_dst);