1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Extension Header handling for IPv6
4 * Linux INET6 implementation
7 * Pedro Roque <roque@di.fc.ul.pt>
8 * Andi Kleen <ak@muc.de>
9 * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
13 * yoshfuji : ensure not to overrun while parsing
15 * Mitsuru KANDA @USAGI and: Remove ipv6_parse_exthdrs().
16 * YOSHIFUJI Hideaki @USAGI Register inbound extension header
17 * handlers as inet6_protocol{}.
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>
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)
46 #include <linux/seg6.h>
48 #ifdef CONFIG_IPV6_SEG6_HMAC
49 #include <net/seg6_hmac.h>
53 #include <linux/uaccess.h>
56 * Parsing tlv encoded headers.
58 * Parsing function "func" returns true, if parsing succeed
59 * and false, if it failed.
60 * It MUST NOT touch skb->h.
65 bool (*func
)(struct sk_buff
*skb
, int offset
);
68 /*********************
70 *********************/
72 /* An unknown option is detected, decide what to do */
74 static bool ip6_tlvopt_unknown(struct sk_buff
*skb
, int optoff
,
75 bool disallow_unknowns
)
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
88 switch ((skb_network_header(skb
)[optoff
] & 0xC0) >> 6) {
92 case 1: /* drop packet */
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.
99 if (ipv6_addr_is_multicast(&ipv6_hdr(skb
)->daddr
))
102 case 2: /* send ICMP PARM PROB regardless and drop packet */
103 icmpv6_param_prob(skb
, ICMPV6_UNK_OPTION
, optoff
);
112 /* Parse tlv encoded option header (hop-by-hop or destination) */
114 static bool ip6_parse_tlv(const struct tlvtype_proc
*procs
,
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;
126 if (unlikely(max_count
< 0)) {
127 disallow_unknowns
= true;
128 max_count
= -max_count
;
131 if (skb_transport_offset(skb
) + len
> skb_headlen(skb
))
138 int optlen
= nh
[off
+ 1] + 2;
150 /* RFC 2460 states that the purpose of PadN is
151 * to align the containing header to multiples
152 * of 8. 7 is therefore the highest valid value.
153 * See also RFC 4942, Section 2.1.9.5.
158 /* RFC 4942 recommends receiving hosts to
159 * actively check PadN payload to contain
162 for (i
= 2; i
< optlen
; i
++) {
163 if (nh
[off
+ i
] != 0)
168 default: /* Other TLV code so scan list */
173 if (tlv_count
> max_count
)
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
181 if (curr
->func(skb
, off
) == false)
186 if (curr
->type
< 0 &&
187 !ip6_tlvopt_unknown(skb
, off
, disallow_unknowns
))
204 /*****************************
205 Destination options header.
206 *****************************/
208 #if IS_ENABLED(CONFIG_IPV6_MIP6)
209 static bool ipv6_dest_hao(struct sk_buff
*skb
, int optoff
)
211 struct ipv6_destopt_hao
*hao
;
212 struct inet6_skb_parm
*opt
= IP6CB(skb
);
213 struct ipv6hdr
*ipv6h
= ipv6_hdr(skb
);
217 net_dbg_ratelimited("hao duplicated\n");
220 opt
->dsthao
= opt
->dst1
;
223 hao
= (struct ipv6_destopt_hao
*)(skb_network_header(skb
) + optoff
);
225 if (hao
->length
!= 16) {
226 net_dbg_ratelimited("hao invalid option length = %d\n",
231 if (!(ipv6_addr_type(&hao
->addr
) & IPV6_ADDR_UNICAST
)) {
232 net_dbg_ratelimited("hao is not an unicast addr: %pI6\n",
237 ret
= xfrm6_input_addr(skb
, (xfrm_address_t
*)&ipv6h
->daddr
,
238 (xfrm_address_t
*)&hao
->addr
, IPPROTO_DSTOPTS
);
239 if (unlikely(ret
< 0))
242 if (skb_cloned(skb
)) {
243 if (pskb_expand_head(skb
, 0, 0, GFP_ATOMIC
))
246 /* update all variable using below by copied skbuff */
247 hao
= (struct ipv6_destopt_hao
*)(skb_network_header(skb
) +
249 ipv6h
= ipv6_hdr(skb
);
252 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
253 skb
->ip_summed
= CHECKSUM_NONE
;
255 swap(ipv6h
->saddr
, hao
->addr
);
257 if (skb
->tstamp
== 0)
258 __net_timestamp(skb
);
268 static const struct tlvtype_proc tlvprocdestopt_lst
[] = {
269 #if IS_ENABLED(CONFIG_IPV6_MIP6)
271 .type
= IPV6_TLV_HAO
,
272 .func
= ipv6_dest_hao
,
278 static int ipv6_destopt_rcv(struct sk_buff
*skb
)
280 struct inet6_dev
*idev
= __in6_dev_get(skb
->dev
);
281 struct inet6_skb_parm
*opt
= IP6CB(skb
);
282 #if IS_ENABLED(CONFIG_IPV6_MIP6)
285 struct dst_entry
*dst
= skb_dst(skb
);
286 struct net
*net
= dev_net(skb
->dev
);
289 if (!pskb_may_pull(skb
, skb_transport_offset(skb
) + 8) ||
290 !pskb_may_pull(skb
, (skb_transport_offset(skb
) +
291 ((skb_transport_header(skb
)[1] + 1) << 3)))) {
292 __IP6_INC_STATS(dev_net(dst
->dev
), idev
,
293 IPSTATS_MIB_INHDRERRORS
);
299 extlen
= (skb_transport_header(skb
)[1] + 1) << 3;
300 if (extlen
> net
->ipv6
.sysctl
.max_dst_opts_len
)
303 opt
->lastopt
= opt
->dst1
= skb_network_header_len(skb
);
304 #if IS_ENABLED(CONFIG_IPV6_MIP6)
308 if (ip6_parse_tlv(tlvprocdestopt_lst
, skb
,
309 init_net
.ipv6
.sysctl
.max_dst_opts_cnt
)) {
310 skb
->transport_header
+= extlen
;
312 #if IS_ENABLED(CONFIG_IPV6_MIP6)
315 opt
->nhoff
= opt
->dst1
;
320 __IP6_INC_STATS(net
, idev
, IPSTATS_MIB_INHDRERRORS
);
324 static void seg6_update_csum(struct sk_buff
*skb
)
326 struct ipv6_sr_hdr
*hdr
;
327 struct in6_addr
*addr
;
330 /* srh is at transport offset and seg_left is already decremented
331 * but daddr is not yet updated with next segment
334 hdr
= (struct ipv6_sr_hdr
*)skb_transport_header(skb
);
335 addr
= hdr
->segments
+ hdr
->segments_left
;
337 hdr
->segments_left
++;
338 from
= *(__be32
*)hdr
;
340 hdr
->segments_left
--;
343 /* update skb csum with diff resulting from seg_left decrement */
345 update_csum_diff4(skb
, from
, to
);
347 /* compute csum diff between current and next segment and update */
349 update_csum_diff16(skb
, (__be32
*)(&ipv6_hdr(skb
)->daddr
),
353 static int ipv6_srh_rcv(struct sk_buff
*skb
)
355 struct inet6_skb_parm
*opt
= IP6CB(skb
);
356 struct net
*net
= dev_net(skb
->dev
);
357 struct ipv6_sr_hdr
*hdr
;
358 struct inet6_dev
*idev
;
359 struct in6_addr
*addr
;
362 hdr
= (struct ipv6_sr_hdr
*)skb_transport_header(skb
);
364 idev
= __in6_dev_get(skb
->dev
);
366 accept_seg6
= net
->ipv6
.devconf_all
->seg6_enabled
;
367 if (accept_seg6
> idev
->cnf
.seg6_enabled
)
368 accept_seg6
= idev
->cnf
.seg6_enabled
;
375 #ifdef CONFIG_IPV6_SEG6_HMAC
376 if (!seg6_hmac_validate_skb(skb
)) {
383 if (hdr
->segments_left
== 0) {
384 if (hdr
->nexthdr
== NEXTHDR_IPV6
) {
385 int offset
= (hdr
->hdrlen
+ 1) << 3;
387 skb_postpull_rcsum(skb
, skb_network_header(skb
),
388 skb_network_header_len(skb
));
390 if (!pskb_pull(skb
, offset
)) {
394 skb_postpull_rcsum(skb
, skb_transport_header(skb
),
397 skb_reset_network_header(skb
);
398 skb_reset_transport_header(skb
);
399 skb
->encapsulation
= 0;
401 __skb_tunnel_rx(skb
, skb
->dev
, net
);
407 opt
->srcrt
= skb_network_header_len(skb
);
408 opt
->lastopt
= opt
->srcrt
;
409 skb
->transport_header
+= (hdr
->hdrlen
+ 1) << 3;
410 opt
->nhoff
= (&hdr
->nexthdr
) - skb_network_header(skb
);
415 if (hdr
->segments_left
>= (hdr
->hdrlen
>> 1)) {
416 __IP6_INC_STATS(net
, idev
, IPSTATS_MIB_INHDRERRORS
);
417 icmpv6_param_prob(skb
, ICMPV6_HDR_FIELD
,
418 ((&hdr
->segments_left
) -
419 skb_network_header(skb
)));
423 if (skb_cloned(skb
)) {
424 if (pskb_expand_head(skb
, 0, 0, GFP_ATOMIC
)) {
425 __IP6_INC_STATS(net
, ip6_dst_idev(skb_dst(skb
)),
426 IPSTATS_MIB_OUTDISCARDS
);
432 hdr
= (struct ipv6_sr_hdr
*)skb_transport_header(skb
);
434 hdr
->segments_left
--;
435 addr
= hdr
->segments
+ hdr
->segments_left
;
437 skb_push(skb
, sizeof(struct ipv6hdr
));
439 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
440 seg6_update_csum(skb
);
442 ipv6_hdr(skb
)->daddr
= *addr
;
446 ip6_route_input(skb
);
448 if (skb_dst(skb
)->error
) {
453 if (skb_dst(skb
)->dev
->flags
& IFF_LOOPBACK
) {
454 if (ipv6_hdr(skb
)->hop_limit
<= 1) {
455 __IP6_INC_STATS(net
, idev
, IPSTATS_MIB_INHDRERRORS
);
456 icmpv6_send(skb
, ICMPV6_TIME_EXCEED
,
457 ICMPV6_EXC_HOPLIMIT
, 0);
461 ipv6_hdr(skb
)->hop_limit
--;
463 skb_pull(skb
, sizeof(struct ipv6hdr
));
472 static int ipv6_rpl_srh_rcv(struct sk_buff
*skb
)
474 struct ipv6_rpl_sr_hdr
*hdr
, *ohdr
, *chdr
;
475 struct inet6_skb_parm
*opt
= IP6CB(skb
);
476 struct net
*net
= dev_net(skb
->dev
);
477 struct inet6_dev
*idev
;
478 struct ipv6hdr
*oldhdr
;
479 struct in6_addr addr
;
486 idev
= __in6_dev_get(skb
->dev
);
488 accept_rpl_seg
= net
->ipv6
.devconf_all
->rpl_seg_enabled
;
489 if (accept_rpl_seg
> idev
->cnf
.rpl_seg_enabled
)
490 accept_rpl_seg
= idev
->cnf
.rpl_seg_enabled
;
492 if (!accept_rpl_seg
) {
498 hdr
= (struct ipv6_rpl_sr_hdr
*)skb_transport_header(skb
);
500 if (hdr
->segments_left
== 0) {
501 if (hdr
->nexthdr
== NEXTHDR_IPV6
) {
502 int offset
= (hdr
->hdrlen
+ 1) << 3;
504 skb_postpull_rcsum(skb
, skb_network_header(skb
),
505 skb_network_header_len(skb
));
507 if (!pskb_pull(skb
, offset
)) {
511 skb_postpull_rcsum(skb
, skb_transport_header(skb
),
514 skb_reset_network_header(skb
);
515 skb_reset_transport_header(skb
);
516 skb
->encapsulation
= 0;
518 __skb_tunnel_rx(skb
, skb
->dev
, net
);
524 opt
->srcrt
= skb_network_header_len(skb
);
525 opt
->lastopt
= opt
->srcrt
;
526 skb
->transport_header
+= (hdr
->hdrlen
+ 1) << 3;
527 opt
->nhoff
= (&hdr
->nexthdr
) - skb_network_header(skb
);
532 if (!pskb_may_pull(skb
, sizeof(*hdr
))) {
537 n
= (hdr
->hdrlen
<< 3) - hdr
->pad
- (16 - hdr
->cmpre
);
538 r
= do_div(n
, (16 - hdr
->cmpri
));
539 /* checks if calculation was without remainder and n fits into
540 * unsigned char which is segments_left field. Should not be
543 if (r
|| (n
+ 1) > 255) {
548 if (hdr
->segments_left
> n
+ 1) {
549 __IP6_INC_STATS(net
, idev
, IPSTATS_MIB_INHDRERRORS
);
550 icmpv6_param_prob(skb
, ICMPV6_HDR_FIELD
,
551 ((&hdr
->segments_left
) -
552 skb_network_header(skb
)));
556 if (skb_cloned(skb
)) {
557 if (pskb_expand_head(skb
, IPV6_RPL_SRH_WORST_SWAP_SIZE
, 0,
559 __IP6_INC_STATS(net
, ip6_dst_idev(skb_dst(skb
)),
560 IPSTATS_MIB_OUTDISCARDS
);
565 err
= skb_cow_head(skb
, IPV6_RPL_SRH_WORST_SWAP_SIZE
);
572 hdr
= (struct ipv6_rpl_sr_hdr
*)skb_transport_header(skb
);
574 if (!pskb_may_pull(skb
, ipv6_rpl_srh_size(n
, hdr
->cmpri
,
580 hdr
->segments_left
--;
581 i
= n
- hdr
->segments_left
;
583 buf
= kcalloc(struct_size(hdr
, segments
.addr
, n
+ 2), 2, GFP_ATOMIC
);
584 if (unlikely(!buf
)) {
589 ohdr
= (struct ipv6_rpl_sr_hdr
*)buf
;
590 ipv6_rpl_srh_decompress(ohdr
, hdr
, &ipv6_hdr(skb
)->daddr
, n
);
591 chdr
= (struct ipv6_rpl_sr_hdr
*)(buf
+ ((ohdr
->hdrlen
+ 1) << 3));
593 if ((ipv6_addr_type(&ipv6_hdr(skb
)->daddr
) & IPV6_ADDR_MULTICAST
) ||
594 (ipv6_addr_type(&ohdr
->rpl_segaddr
[i
]) & IPV6_ADDR_MULTICAST
)) {
600 err
= ipv6_chk_rpl_srh_loop(net
, ohdr
->rpl_segaddr
, n
+ 1);
602 icmpv6_send(skb
, ICMPV6_PARAMPROB
, 0, 0);
608 addr
= ipv6_hdr(skb
)->daddr
;
609 ipv6_hdr(skb
)->daddr
= ohdr
->rpl_segaddr
[i
];
610 ohdr
->rpl_segaddr
[i
] = addr
;
612 ipv6_rpl_srh_compress(chdr
, ohdr
, &ipv6_hdr(skb
)->daddr
, n
);
614 oldhdr
= ipv6_hdr(skb
);
616 skb_pull(skb
, ((hdr
->hdrlen
+ 1) << 3));
617 skb_postpull_rcsum(skb
, oldhdr
,
618 sizeof(struct ipv6hdr
) + ((hdr
->hdrlen
+ 1) << 3));
619 skb_push(skb
, ((chdr
->hdrlen
+ 1) << 3) + sizeof(struct ipv6hdr
));
620 skb_reset_network_header(skb
);
621 skb_mac_header_rebuild(skb
);
622 skb_set_transport_header(skb
, sizeof(struct ipv6hdr
));
624 memmove(ipv6_hdr(skb
), oldhdr
, sizeof(struct ipv6hdr
));
625 memcpy(skb_transport_header(skb
), chdr
, (chdr
->hdrlen
+ 1) << 3);
627 ipv6_hdr(skb
)->payload_len
= htons(skb
->len
- sizeof(struct ipv6hdr
));
628 skb_postpush_rcsum(skb
, ipv6_hdr(skb
),
629 sizeof(struct ipv6hdr
) + ((chdr
->hdrlen
+ 1) << 3));
635 ip6_route_input(skb
);
637 if (skb_dst(skb
)->error
) {
642 if (skb_dst(skb
)->dev
->flags
& IFF_LOOPBACK
) {
643 if (ipv6_hdr(skb
)->hop_limit
<= 1) {
644 __IP6_INC_STATS(net
, idev
, IPSTATS_MIB_INHDRERRORS
);
645 icmpv6_send(skb
, ICMPV6_TIME_EXCEED
,
646 ICMPV6_EXC_HOPLIMIT
, 0);
650 ipv6_hdr(skb
)->hop_limit
--;
652 skb_pull(skb
, sizeof(struct ipv6hdr
));
661 /********************************
663 ********************************/
665 /* called with rcu_read_lock() */
666 static int ipv6_rthdr_rcv(struct sk_buff
*skb
)
668 struct inet6_dev
*idev
= __in6_dev_get(skb
->dev
);
669 struct inet6_skb_parm
*opt
= IP6CB(skb
);
670 struct in6_addr
*addr
= NULL
;
671 struct in6_addr daddr
;
673 struct ipv6_rt_hdr
*hdr
;
674 struct rt0_hdr
*rthdr
;
675 struct net
*net
= dev_net(skb
->dev
);
676 int accept_source_route
= net
->ipv6
.devconf_all
->accept_source_route
;
678 idev
= __in6_dev_get(skb
->dev
);
679 if (idev
&& accept_source_route
> idev
->cnf
.accept_source_route
)
680 accept_source_route
= idev
->cnf
.accept_source_route
;
682 if (!pskb_may_pull(skb
, skb_transport_offset(skb
) + 8) ||
683 !pskb_may_pull(skb
, (skb_transport_offset(skb
) +
684 ((skb_transport_header(skb
)[1] + 1) << 3)))) {
685 __IP6_INC_STATS(net
, idev
, IPSTATS_MIB_INHDRERRORS
);
690 hdr
= (struct ipv6_rt_hdr
*)skb_transport_header(skb
);
692 if (ipv6_addr_is_multicast(&ipv6_hdr(skb
)->daddr
) ||
693 skb
->pkt_type
!= PACKET_HOST
) {
694 __IP6_INC_STATS(net
, idev
, IPSTATS_MIB_INADDRERRORS
);
700 case IPV6_SRCRT_TYPE_4
:
701 /* segment routing */
702 return ipv6_srh_rcv(skb
);
703 case IPV6_SRCRT_TYPE_3
:
704 /* rpl segment routing */
705 return ipv6_rpl_srh_rcv(skb
);
711 if (hdr
->segments_left
== 0) {
713 #if IS_ENABLED(CONFIG_IPV6_MIP6)
714 case IPV6_SRCRT_TYPE_2
:
715 /* Silently discard type 2 header unless it was
719 __IP6_INC_STATS(net
, idev
,
720 IPSTATS_MIB_INADDRERRORS
);
730 opt
->lastopt
= opt
->srcrt
= skb_network_header_len(skb
);
731 skb
->transport_header
+= (hdr
->hdrlen
+ 1) << 3;
732 opt
->dst0
= opt
->dst1
;
734 opt
->nhoff
= (&hdr
->nexthdr
) - skb_network_header(skb
);
739 #if IS_ENABLED(CONFIG_IPV6_MIP6)
740 case IPV6_SRCRT_TYPE_2
:
741 if (accept_source_route
< 0)
743 /* Silently discard invalid RTH type 2 */
744 if (hdr
->hdrlen
!= 2 || hdr
->segments_left
!= 1) {
745 __IP6_INC_STATS(net
, idev
, IPSTATS_MIB_INHDRERRORS
);
756 * This is the routing header forwarding algorithm from
760 n
= hdr
->hdrlen
>> 1;
762 if (hdr
->segments_left
> n
) {
763 __IP6_INC_STATS(net
, idev
, IPSTATS_MIB_INHDRERRORS
);
764 icmpv6_param_prob(skb
, ICMPV6_HDR_FIELD
,
765 ((&hdr
->segments_left
) -
766 skb_network_header(skb
)));
770 /* We are about to mangle packet header. Be careful!
771 Do not damage packets queued somewhere.
773 if (skb_cloned(skb
)) {
774 /* the copy is a forwarded packet */
775 if (pskb_expand_head(skb
, 0, 0, GFP_ATOMIC
)) {
776 __IP6_INC_STATS(net
, ip6_dst_idev(skb_dst(skb
)),
777 IPSTATS_MIB_OUTDISCARDS
);
781 hdr
= (struct ipv6_rt_hdr
*)skb_transport_header(skb
);
784 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
785 skb
->ip_summed
= CHECKSUM_NONE
;
787 i
= n
- --hdr
->segments_left
;
789 rthdr
= (struct rt0_hdr
*) hdr
;
794 #if IS_ENABLED(CONFIG_IPV6_MIP6)
795 case IPV6_SRCRT_TYPE_2
:
796 if (xfrm6_input_addr(skb
, (xfrm_address_t
*)addr
,
797 (xfrm_address_t
*)&ipv6_hdr(skb
)->saddr
,
798 IPPROTO_ROUTING
) < 0) {
799 __IP6_INC_STATS(net
, idev
, IPSTATS_MIB_INADDRERRORS
);
803 if (!ipv6_chk_home_addr(dev_net(skb_dst(skb
)->dev
), addr
)) {
804 __IP6_INC_STATS(net
, idev
, IPSTATS_MIB_INADDRERRORS
);
814 if (ipv6_addr_is_multicast(addr
)) {
815 __IP6_INC_STATS(net
, idev
, IPSTATS_MIB_INADDRERRORS
);
821 *addr
= ipv6_hdr(skb
)->daddr
;
822 ipv6_hdr(skb
)->daddr
= daddr
;
825 ip6_route_input(skb
);
826 if (skb_dst(skb
)->error
) {
827 skb_push(skb
, skb
->data
- skb_network_header(skb
));
832 if (skb_dst(skb
)->dev
->flags
&IFF_LOOPBACK
) {
833 if (ipv6_hdr(skb
)->hop_limit
<= 1) {
834 __IP6_INC_STATS(net
, idev
, IPSTATS_MIB_INHDRERRORS
);
835 icmpv6_send(skb
, ICMPV6_TIME_EXCEED
, ICMPV6_EXC_HOPLIMIT
,
840 ipv6_hdr(skb
)->hop_limit
--;
844 skb_push(skb
, skb
->data
- skb_network_header(skb
));
849 __IP6_INC_STATS(net
, idev
, IPSTATS_MIB_INHDRERRORS
);
850 icmpv6_param_prob(skb
, ICMPV6_HDR_FIELD
,
851 (&hdr
->type
) - skb_network_header(skb
));
855 static const struct inet6_protocol rthdr_protocol
= {
856 .handler
= ipv6_rthdr_rcv
,
857 .flags
= INET6_PROTO_NOPOLICY
,
860 static const struct inet6_protocol destopt_protocol
= {
861 .handler
= ipv6_destopt_rcv
,
862 .flags
= INET6_PROTO_NOPOLICY
,
865 static const struct inet6_protocol nodata_protocol
= {
866 .handler
= dst_discard
,
867 .flags
= INET6_PROTO_NOPOLICY
,
870 int __init
ipv6_exthdrs_init(void)
874 ret
= inet6_add_protocol(&rthdr_protocol
, IPPROTO_ROUTING
);
878 ret
= inet6_add_protocol(&destopt_protocol
, IPPROTO_DSTOPTS
);
882 ret
= inet6_add_protocol(&nodata_protocol
, IPPROTO_NONE
);
889 inet6_del_protocol(&destopt_protocol
, IPPROTO_DSTOPTS
);
891 inet6_del_protocol(&rthdr_protocol
, IPPROTO_ROUTING
);
895 void ipv6_exthdrs_exit(void)
897 inet6_del_protocol(&nodata_protocol
, IPPROTO_NONE
);
898 inet6_del_protocol(&destopt_protocol
, IPPROTO_DSTOPTS
);
899 inet6_del_protocol(&rthdr_protocol
, IPPROTO_ROUTING
);
902 /**********************************
904 **********************************/
907 * Note: we cannot rely on skb_dst(skb) before we assign it in ip6_route_input().
909 static inline struct net
*ipv6_skb_net(struct sk_buff
*skb
)
911 return skb_dst(skb
) ? dev_net(skb_dst(skb
)->dev
) : dev_net(skb
->dev
);
914 /* Router Alert as of RFC 2711 */
916 static bool ipv6_hop_ra(struct sk_buff
*skb
, int optoff
)
918 const unsigned char *nh
= skb_network_header(skb
);
920 if (nh
[optoff
+ 1] == 2) {
921 IP6CB(skb
)->flags
|= IP6SKB_ROUTERALERT
;
922 memcpy(&IP6CB(skb
)->ra
, nh
+ optoff
+ 2, sizeof(IP6CB(skb
)->ra
));
925 net_dbg_ratelimited("ipv6_hop_ra: wrong RA length %d\n",
933 static bool ipv6_hop_jumbo(struct sk_buff
*skb
, int optoff
)
935 const unsigned char *nh
= skb_network_header(skb
);
936 struct inet6_dev
*idev
= __in6_dev_get_safely(skb
->dev
);
937 struct net
*net
= ipv6_skb_net(skb
);
940 if (nh
[optoff
+ 1] != 4 || (optoff
& 3) != 2) {
941 net_dbg_ratelimited("ipv6_hop_jumbo: wrong jumbo opt length/alignment %d\n",
943 __IP6_INC_STATS(net
, idev
, IPSTATS_MIB_INHDRERRORS
);
947 pkt_len
= ntohl(*(__be32
*)(nh
+ optoff
+ 2));
948 if (pkt_len
<= IPV6_MAXPLEN
) {
949 __IP6_INC_STATS(net
, idev
, IPSTATS_MIB_INHDRERRORS
);
950 icmpv6_param_prob(skb
, ICMPV6_HDR_FIELD
, optoff
+2);
953 if (ipv6_hdr(skb
)->payload_len
) {
954 __IP6_INC_STATS(net
, idev
, IPSTATS_MIB_INHDRERRORS
);
955 icmpv6_param_prob(skb
, ICMPV6_HDR_FIELD
, optoff
);
959 if (pkt_len
> skb
->len
- sizeof(struct ipv6hdr
)) {
960 __IP6_INC_STATS(net
, idev
, IPSTATS_MIB_INTRUNCATEDPKTS
);
964 if (pskb_trim_rcsum(skb
, pkt_len
+ sizeof(struct ipv6hdr
)))
967 IP6CB(skb
)->flags
|= IP6SKB_JUMBOGRAM
;
975 /* CALIPSO RFC 5570 */
977 static bool ipv6_hop_calipso(struct sk_buff
*skb
, int optoff
)
979 const unsigned char *nh
= skb_network_header(skb
);
981 if (nh
[optoff
+ 1] < 8)
984 if (nh
[optoff
+ 6] * 4 + 8 > nh
[optoff
+ 1])
987 if (!calipso_validate(skb
, nh
+ optoff
))
997 static const struct tlvtype_proc tlvprochopopt_lst
[] = {
999 .type
= IPV6_TLV_ROUTERALERT
,
1000 .func
= ipv6_hop_ra
,
1003 .type
= IPV6_TLV_JUMBO
,
1004 .func
= ipv6_hop_jumbo
,
1007 .type
= IPV6_TLV_CALIPSO
,
1008 .func
= ipv6_hop_calipso
,
1013 int ipv6_parse_hopopts(struct sk_buff
*skb
)
1015 struct inet6_skb_parm
*opt
= IP6CB(skb
);
1016 struct net
*net
= dev_net(skb
->dev
);
1020 * skb_network_header(skb) is equal to skb->data, and
1021 * skb_network_header_len(skb) is always equal to
1022 * sizeof(struct ipv6hdr) by definition of
1023 * hop-by-hop options.
1025 if (!pskb_may_pull(skb
, sizeof(struct ipv6hdr
) + 8) ||
1026 !pskb_may_pull(skb
, (sizeof(struct ipv6hdr
) +
1027 ((skb_transport_header(skb
)[1] + 1) << 3)))) {
1033 extlen
= (skb_transport_header(skb
)[1] + 1) << 3;
1034 if (extlen
> net
->ipv6
.sysctl
.max_hbh_opts_len
)
1037 opt
->flags
|= IP6SKB_HOPBYHOP
;
1038 if (ip6_parse_tlv(tlvprochopopt_lst
, skb
,
1039 init_net
.ipv6
.sysctl
.max_hbh_opts_cnt
)) {
1040 skb
->transport_header
+= extlen
;
1042 opt
->nhoff
= sizeof(struct ipv6hdr
);
1049 * Creating outbound headers.
1051 * "build" functions work when skb is filled from head to tail (datagram)
1052 * "push" functions work when headers are added from tail to head (tcp)
1054 * In both cases we assume, that caller reserved enough room
1058 static void ipv6_push_rthdr0(struct sk_buff
*skb
, u8
*proto
,
1059 struct ipv6_rt_hdr
*opt
,
1060 struct in6_addr
**addr_p
, struct in6_addr
*saddr
)
1062 struct rt0_hdr
*phdr
, *ihdr
;
1065 ihdr
= (struct rt0_hdr
*) opt
;
1067 phdr
= skb_push(skb
, (ihdr
->rt_hdr
.hdrlen
+ 1) << 3);
1068 memcpy(phdr
, ihdr
, sizeof(struct rt0_hdr
));
1070 hops
= ihdr
->rt_hdr
.hdrlen
>> 1;
1073 memcpy(phdr
->addr
, ihdr
->addr
+ 1,
1074 (hops
- 1) * sizeof(struct in6_addr
));
1076 phdr
->addr
[hops
- 1] = **addr_p
;
1077 *addr_p
= ihdr
->addr
;
1079 phdr
->rt_hdr
.nexthdr
= *proto
;
1080 *proto
= NEXTHDR_ROUTING
;
1083 static void ipv6_push_rthdr4(struct sk_buff
*skb
, u8
*proto
,
1084 struct ipv6_rt_hdr
*opt
,
1085 struct in6_addr
**addr_p
, struct in6_addr
*saddr
)
1087 struct ipv6_sr_hdr
*sr_phdr
, *sr_ihdr
;
1090 sr_ihdr
= (struct ipv6_sr_hdr
*)opt
;
1091 plen
= (sr_ihdr
->hdrlen
+ 1) << 3;
1093 sr_phdr
= skb_push(skb
, plen
);
1094 memcpy(sr_phdr
, sr_ihdr
, sizeof(struct ipv6_sr_hdr
));
1096 hops
= sr_ihdr
->first_segment
+ 1;
1097 memcpy(sr_phdr
->segments
+ 1, sr_ihdr
->segments
+ 1,
1098 (hops
- 1) * sizeof(struct in6_addr
));
1100 sr_phdr
->segments
[0] = **addr_p
;
1101 *addr_p
= &sr_ihdr
->segments
[sr_ihdr
->segments_left
];
1103 if (sr_ihdr
->hdrlen
> hops
* 2) {
1104 int tlvs_offset
, tlvs_length
;
1106 tlvs_offset
= (1 + hops
* 2) << 3;
1107 tlvs_length
= (sr_ihdr
->hdrlen
- hops
* 2) << 3;
1108 memcpy((char *)sr_phdr
+ tlvs_offset
,
1109 (char *)sr_ihdr
+ tlvs_offset
, tlvs_length
);
1112 #ifdef CONFIG_IPV6_SEG6_HMAC
1113 if (sr_has_hmac(sr_phdr
)) {
1114 struct net
*net
= NULL
;
1117 net
= dev_net(skb
->dev
);
1119 net
= sock_net(skb
->sk
);
1124 seg6_push_hmac(net
, saddr
, sr_phdr
);
1128 sr_phdr
->nexthdr
= *proto
;
1129 *proto
= NEXTHDR_ROUTING
;
1132 static void ipv6_push_rthdr(struct sk_buff
*skb
, u8
*proto
,
1133 struct ipv6_rt_hdr
*opt
,
1134 struct in6_addr
**addr_p
, struct in6_addr
*saddr
)
1136 switch (opt
->type
) {
1137 case IPV6_SRCRT_TYPE_0
:
1138 case IPV6_SRCRT_STRICT
:
1139 case IPV6_SRCRT_TYPE_2
:
1140 ipv6_push_rthdr0(skb
, proto
, opt
, addr_p
, saddr
);
1142 case IPV6_SRCRT_TYPE_4
:
1143 ipv6_push_rthdr4(skb
, proto
, opt
, addr_p
, saddr
);
1150 static void ipv6_push_exthdr(struct sk_buff
*skb
, u8
*proto
, u8 type
, struct ipv6_opt_hdr
*opt
)
1152 struct ipv6_opt_hdr
*h
= skb_push(skb
, ipv6_optlen(opt
));
1154 memcpy(h
, opt
, ipv6_optlen(opt
));
1155 h
->nexthdr
= *proto
;
1159 void ipv6_push_nfrag_opts(struct sk_buff
*skb
, struct ipv6_txoptions
*opt
,
1161 struct in6_addr
**daddr
, struct in6_addr
*saddr
)
1164 ipv6_push_rthdr(skb
, proto
, opt
->srcrt
, daddr
, saddr
);
1166 * IPV6_RTHDRDSTOPTS is ignored
1167 * unless IPV6_RTHDR is set (RFC3542).
1170 ipv6_push_exthdr(skb
, proto
, NEXTHDR_DEST
, opt
->dst0opt
);
1173 ipv6_push_exthdr(skb
, proto
, NEXTHDR_HOP
, opt
->hopopt
);
1176 void ipv6_push_frag_opts(struct sk_buff
*skb
, struct ipv6_txoptions
*opt
, u8
*proto
)
1179 ipv6_push_exthdr(skb
, proto
, NEXTHDR_DEST
, opt
->dst1opt
);
1181 EXPORT_SYMBOL(ipv6_push_frag_opts
);
1183 struct ipv6_txoptions
*
1184 ipv6_dup_options(struct sock
*sk
, struct ipv6_txoptions
*opt
)
1186 struct ipv6_txoptions
*opt2
;
1188 opt2
= sock_kmalloc(sk
, opt
->tot_len
, GFP_ATOMIC
);
1190 long dif
= (char *)opt2
- (char *)opt
;
1191 memcpy(opt2
, opt
, opt
->tot_len
);
1193 *((char **)&opt2
->hopopt
) += dif
;
1195 *((char **)&opt2
->dst0opt
) += dif
;
1197 *((char **)&opt2
->dst1opt
) += dif
;
1199 *((char **)&opt2
->srcrt
) += dif
;
1200 refcount_set(&opt2
->refcnt
, 1);
1204 EXPORT_SYMBOL_GPL(ipv6_dup_options
);
1206 static void ipv6_renew_option(int renewtype
,
1207 struct ipv6_opt_hdr
**dest
,
1208 struct ipv6_opt_hdr
*old
,
1209 struct ipv6_opt_hdr
*new,
1210 int newtype
, char **p
)
1212 struct ipv6_opt_hdr
*src
;
1214 src
= (renewtype
== newtype
? new : old
);
1218 memcpy(*p
, src
, ipv6_optlen(src
));
1219 *dest
= (struct ipv6_opt_hdr
*)*p
;
1220 *p
+= CMSG_ALIGN(ipv6_optlen(*dest
));
1224 * ipv6_renew_options - replace a specific ext hdr with a new one.
1226 * @sk: sock from which to allocate memory
1227 * @opt: original options
1228 * @newtype: option type to replace in @opt
1229 * @newopt: new option of type @newtype to replace (user-mem)
1231 * Returns a new set of options which is a copy of @opt with the
1232 * option type @newtype replaced with @newopt.
1234 * @opt may be NULL, in which case a new set of options is returned
1235 * containing just @newopt.
1237 * @newopt may be NULL, in which case the specified option type is
1238 * not copied into the new set of options.
1240 * The new set of options is allocated from the socket option memory
1243 struct ipv6_txoptions
*
1244 ipv6_renew_options(struct sock
*sk
, struct ipv6_txoptions
*opt
,
1245 int newtype
, struct ipv6_opt_hdr
*newopt
)
1249 struct ipv6_txoptions
*opt2
;
1252 if (newtype
!= IPV6_HOPOPTS
&& opt
->hopopt
)
1253 tot_len
+= CMSG_ALIGN(ipv6_optlen(opt
->hopopt
));
1254 if (newtype
!= IPV6_RTHDRDSTOPTS
&& opt
->dst0opt
)
1255 tot_len
+= CMSG_ALIGN(ipv6_optlen(opt
->dst0opt
));
1256 if (newtype
!= IPV6_RTHDR
&& opt
->srcrt
)
1257 tot_len
+= CMSG_ALIGN(ipv6_optlen(opt
->srcrt
));
1258 if (newtype
!= IPV6_DSTOPTS
&& opt
->dst1opt
)
1259 tot_len
+= CMSG_ALIGN(ipv6_optlen(opt
->dst1opt
));
1263 tot_len
+= CMSG_ALIGN(ipv6_optlen(newopt
));
1268 tot_len
+= sizeof(*opt2
);
1269 opt2
= sock_kmalloc(sk
, tot_len
, GFP_ATOMIC
);
1271 return ERR_PTR(-ENOBUFS
);
1273 memset(opt2
, 0, tot_len
);
1274 refcount_set(&opt2
->refcnt
, 1);
1275 opt2
->tot_len
= tot_len
;
1276 p
= (char *)(opt2
+ 1);
1278 ipv6_renew_option(IPV6_HOPOPTS
, &opt2
->hopopt
,
1279 (opt
? opt
->hopopt
: NULL
),
1280 newopt
, newtype
, &p
);
1281 ipv6_renew_option(IPV6_RTHDRDSTOPTS
, &opt2
->dst0opt
,
1282 (opt
? opt
->dst0opt
: NULL
),
1283 newopt
, newtype
, &p
);
1284 ipv6_renew_option(IPV6_RTHDR
,
1285 (struct ipv6_opt_hdr
**)&opt2
->srcrt
,
1286 (opt
? (struct ipv6_opt_hdr
*)opt
->srcrt
: NULL
),
1287 newopt
, newtype
, &p
);
1288 ipv6_renew_option(IPV6_DSTOPTS
, &opt2
->dst1opt
,
1289 (opt
? opt
->dst1opt
: NULL
),
1290 newopt
, newtype
, &p
);
1292 opt2
->opt_nflen
= (opt2
->hopopt
? ipv6_optlen(opt2
->hopopt
) : 0) +
1293 (opt2
->dst0opt
? ipv6_optlen(opt2
->dst0opt
) : 0) +
1294 (opt2
->srcrt
? ipv6_optlen(opt2
->srcrt
) : 0);
1295 opt2
->opt_flen
= (opt2
->dst1opt
? ipv6_optlen(opt2
->dst1opt
) : 0);
1300 struct ipv6_txoptions
*ipv6_fixup_options(struct ipv6_txoptions
*opt_space
,
1301 struct ipv6_txoptions
*opt
)
1304 * ignore the dest before srcrt unless srcrt is being included.
1307 if (opt
&& opt
->dst0opt
&& !opt
->srcrt
) {
1308 if (opt_space
!= opt
) {
1309 memcpy(opt_space
, opt
, sizeof(*opt_space
));
1312 opt
->opt_nflen
-= ipv6_optlen(opt
->dst0opt
);
1313 opt
->dst0opt
= NULL
;
1318 EXPORT_SYMBOL_GPL(ipv6_fixup_options
);
1321 * fl6_update_dst - update flowi destination address with info given
1322 * by srcrt option, if any.
1324 * @fl6: flowi6 for which daddr is to be updated
1325 * @opt: struct ipv6_txoptions in which to look for srcrt opt
1326 * @orig: copy of original daddr address if modified
1328 * Returns NULL if no txoptions or no srcrt, otherwise returns orig
1329 * and initial value of fl6->daddr set in orig
1331 struct in6_addr
*fl6_update_dst(struct flowi6
*fl6
,
1332 const struct ipv6_txoptions
*opt
,
1333 struct in6_addr
*orig
)
1335 if (!opt
|| !opt
->srcrt
)
1340 switch (opt
->srcrt
->type
) {
1341 case IPV6_SRCRT_TYPE_0
:
1342 case IPV6_SRCRT_STRICT
:
1343 case IPV6_SRCRT_TYPE_2
:
1344 fl6
->daddr
= *((struct rt0_hdr
*)opt
->srcrt
)->addr
;
1346 case IPV6_SRCRT_TYPE_4
:
1348 struct ipv6_sr_hdr
*srh
= (struct ipv6_sr_hdr
*)opt
->srcrt
;
1350 fl6
->daddr
= srh
->segments
[srh
->segments_left
];
1359 EXPORT_SYMBOL_GPL(fl6_update_dst
);