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 #include <net/calipso.h>
47 #if IS_ENABLED(CONFIG_IPV6_MIP6)
50 #include <linux/seg6.h>
52 #ifdef CONFIG_IPV6_SEG6_HMAC
53 #include <net/seg6_hmac.h>
56 #include <linux/uaccess.h>
59 * Parsing tlv encoded headers.
61 * Parsing function "func" returns true, if parsing succeed
62 * and false, if it failed.
63 * It MUST NOT touch skb->h.
68 bool (*func)(struct sk_buff *skb, int offset);
71 /*********************
73 *********************/
75 /* An unknown option is detected, decide what to do */
77 static bool ip6_tlvopt_unknown(struct sk_buff *skb, int optoff,
78 bool disallow_unknowns)
80 if (disallow_unknowns) {
81 /* If unknown TLVs are disallowed by configuration
82 * then always silently drop packet. Note this also
83 * means no ICMP parameter problem is sent which
84 * could be a good property to mitigate a reflection DOS
91 switch ((skb_network_header(skb)[optoff] & 0xC0) >> 6) {
95 case 1: /* drop packet */
98 case 3: /* Send ICMP if not a multicast address and drop packet */
99 /* Actually, it is redundant check. icmp_send
100 will recheck in any case.
102 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr))
105 case 2: /* send ICMP PARM PROB regardless and drop packet */
106 icmpv6_param_prob(skb, ICMPV6_UNK_OPTION, optoff);
115 /* Parse tlv encoded option header (hop-by-hop or destination) */
117 static bool ip6_parse_tlv(const struct tlvtype_proc *procs,
121 int len = (skb_transport_header(skb)[1] + 1) << 3;
122 const unsigned char *nh = skb_network_header(skb);
123 int off = skb_network_header_len(skb);
124 const struct tlvtype_proc *curr;
125 bool disallow_unknowns = false;
129 if (unlikely(max_count < 0)) {
130 disallow_unknowns = true;
131 max_count = -max_count;
134 if (skb_transport_offset(skb) + len > skb_headlen(skb))
143 if (nh[off] == IPV6_TLV_PAD1) {
153 optlen = nh[off + 1] + 2;
157 if (nh[off] == IPV6_TLV_PADN) {
158 /* RFC 2460 states that the purpose of PadN is
159 * to align the containing header to multiples
160 * of 8. 7 is therefore the highest valid value.
161 * See also RFC 4942, Section 2.1.9.5.
166 /* RFC 4942 recommends receiving hosts to
167 * actively check PadN payload to contain
170 for (i = 2; i < optlen; i++) {
171 if (nh[off + i] != 0)
176 if (tlv_count > max_count)
179 for (curr = procs; curr->type >= 0; curr++) {
180 if (curr->type == nh[off]) {
181 /* type specific length/alignment
182 checks will be performed in the
184 if (curr->func(skb, off) == false)
189 if (curr->type < 0 &&
190 !ip6_tlvopt_unknown(skb, off, disallow_unknowns))
206 /*****************************
207 Destination options header.
208 *****************************/
210 #if IS_ENABLED(CONFIG_IPV6_MIP6)
211 static bool ipv6_dest_hao(struct sk_buff *skb, int optoff)
213 struct ipv6_destopt_hao *hao;
214 struct inet6_skb_parm *opt = IP6CB(skb);
215 struct ipv6hdr *ipv6h = ipv6_hdr(skb);
219 net_dbg_ratelimited("hao duplicated\n");
222 opt->dsthao = opt->dst1;
225 hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) + optoff);
227 if (hao->length != 16) {
228 net_dbg_ratelimited("hao invalid option length = %d\n",
233 if (!(ipv6_addr_type(&hao->addr) & IPV6_ADDR_UNICAST)) {
234 net_dbg_ratelimited("hao is not an unicast addr: %pI6\n",
239 ret = xfrm6_input_addr(skb, (xfrm_address_t *)&ipv6h->daddr,
240 (xfrm_address_t *)&hao->addr, IPPROTO_DSTOPTS);
241 if (unlikely(ret < 0))
244 if (skb_cloned(skb)) {
245 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
248 /* update all variable using below by copied skbuff */
249 hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) +
251 ipv6h = ipv6_hdr(skb);
254 if (skb->ip_summed == CHECKSUM_COMPLETE)
255 skb->ip_summed = CHECKSUM_NONE;
257 swap(ipv6h->saddr, hao->addr);
259 if (skb->tstamp == 0)
260 __net_timestamp(skb);
270 static const struct tlvtype_proc tlvprocdestopt_lst[] = {
271 #if IS_ENABLED(CONFIG_IPV6_MIP6)
273 .type = IPV6_TLV_HAO,
274 .func = ipv6_dest_hao,
280 static int ipv6_destopt_rcv(struct sk_buff *skb)
282 struct inet6_dev *idev = __in6_dev_get(skb->dev);
283 struct inet6_skb_parm *opt = IP6CB(skb);
284 #if IS_ENABLED(CONFIG_IPV6_MIP6)
287 struct dst_entry *dst = skb_dst(skb);
288 struct net *net = dev_net(skb->dev);
291 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
292 !pskb_may_pull(skb, (skb_transport_offset(skb) +
293 ((skb_transport_header(skb)[1] + 1) << 3)))) {
294 __IP6_INC_STATS(dev_net(dst->dev), idev,
295 IPSTATS_MIB_INHDRERRORS);
301 extlen = (skb_transport_header(skb)[1] + 1) << 3;
302 if (extlen > net->ipv6.sysctl.max_dst_opts_len)
305 opt->lastopt = opt->dst1 = skb_network_header_len(skb);
306 #if IS_ENABLED(CONFIG_IPV6_MIP6)
310 if (ip6_parse_tlv(tlvprocdestopt_lst, skb,
311 net->ipv6.sysctl.max_dst_opts_cnt)) {
312 skb->transport_header += extlen;
314 #if IS_ENABLED(CONFIG_IPV6_MIP6)
317 opt->nhoff = opt->dst1;
322 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
326 static void seg6_update_csum(struct sk_buff *skb)
328 struct ipv6_sr_hdr *hdr;
329 struct in6_addr *addr;
332 /* srh is at transport offset and seg_left is already decremented
333 * but daddr is not yet updated with next segment
336 hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb);
337 addr = hdr->segments + hdr->segments_left;
339 hdr->segments_left++;
340 from = *(__be32 *)hdr;
342 hdr->segments_left--;
345 /* update skb csum with diff resulting from seg_left decrement */
347 update_csum_diff4(skb, from, to);
349 /* compute csum diff between current and next segment and update */
351 update_csum_diff16(skb, (__be32 *)(&ipv6_hdr(skb)->daddr),
355 static int ipv6_srh_rcv(struct sk_buff *skb)
357 struct inet6_skb_parm *opt = IP6CB(skb);
358 struct net *net = dev_net(skb->dev);
359 struct ipv6_sr_hdr *hdr;
360 struct inet6_dev *idev;
361 struct in6_addr *addr;
364 hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb);
366 idev = __in6_dev_get(skb->dev);
368 accept_seg6 = net->ipv6.devconf_all->seg6_enabled;
369 if (accept_seg6 > idev->cnf.seg6_enabled)
370 accept_seg6 = idev->cnf.seg6_enabled;
377 #ifdef CONFIG_IPV6_SEG6_HMAC
378 if (!seg6_hmac_validate_skb(skb)) {
385 if (hdr->segments_left == 0) {
386 if (hdr->nexthdr == NEXTHDR_IPV6) {
387 int offset = (hdr->hdrlen + 1) << 3;
389 skb_postpull_rcsum(skb, skb_network_header(skb),
390 skb_network_header_len(skb));
392 if (!pskb_pull(skb, offset)) {
396 skb_postpull_rcsum(skb, skb_transport_header(skb),
399 skb_reset_network_header(skb);
400 skb_reset_transport_header(skb);
401 skb->encapsulation = 0;
403 __skb_tunnel_rx(skb, skb->dev, net);
409 opt->srcrt = skb_network_header_len(skb);
410 opt->lastopt = opt->srcrt;
411 skb->transport_header += (hdr->hdrlen + 1) << 3;
412 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb);
417 if (hdr->segments_left >= (hdr->hdrlen >> 1)) {
418 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
419 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
420 ((&hdr->segments_left) -
421 skb_network_header(skb)));
425 if (skb_cloned(skb)) {
426 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) {
427 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
428 IPSTATS_MIB_OUTDISCARDS);
434 hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb);
436 hdr->segments_left--;
437 addr = hdr->segments + hdr->segments_left;
439 skb_push(skb, sizeof(struct ipv6hdr));
441 if (skb->ip_summed == CHECKSUM_COMPLETE)
442 seg6_update_csum(skb);
444 ipv6_hdr(skb)->daddr = *addr;
448 ip6_route_input(skb);
450 if (skb_dst(skb)->error) {
455 if (skb_dst(skb)->dev->flags & IFF_LOOPBACK) {
456 if (ipv6_hdr(skb)->hop_limit <= 1) {
457 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
458 icmpv6_send(skb, ICMPV6_TIME_EXCEED,
459 ICMPV6_EXC_HOPLIMIT, 0);
463 ipv6_hdr(skb)->hop_limit--;
465 skb_pull(skb, sizeof(struct ipv6hdr));
474 /********************************
476 ********************************/
478 /* called with rcu_read_lock() */
479 static int ipv6_rthdr_rcv(struct sk_buff *skb)
481 struct inet6_dev *idev = __in6_dev_get(skb->dev);
482 struct inet6_skb_parm *opt = IP6CB(skb);
483 struct in6_addr *addr = NULL;
484 struct in6_addr daddr;
486 struct ipv6_rt_hdr *hdr;
487 struct rt0_hdr *rthdr;
488 struct net *net = dev_net(skb->dev);
489 int accept_source_route = net->ipv6.devconf_all->accept_source_route;
491 idev = __in6_dev_get(skb->dev);
492 if (idev && accept_source_route > idev->cnf.accept_source_route)
493 accept_source_route = idev->cnf.accept_source_route;
495 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
496 !pskb_may_pull(skb, (skb_transport_offset(skb) +
497 ((skb_transport_header(skb)[1] + 1) << 3)))) {
498 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
503 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb);
505 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) ||
506 skb->pkt_type != PACKET_HOST) {
507 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
512 /* segment routing */
513 if (hdr->type == IPV6_SRCRT_TYPE_4)
514 return ipv6_srh_rcv(skb);
517 if (hdr->segments_left == 0) {
519 #if IS_ENABLED(CONFIG_IPV6_MIP6)
520 case IPV6_SRCRT_TYPE_2:
521 /* Silently discard type 2 header unless it was
525 __IP6_INC_STATS(net, idev,
526 IPSTATS_MIB_INADDRERRORS);
536 opt->lastopt = opt->srcrt = skb_network_header_len(skb);
537 skb->transport_header += (hdr->hdrlen + 1) << 3;
538 opt->dst0 = opt->dst1;
540 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb);
545 #if IS_ENABLED(CONFIG_IPV6_MIP6)
546 case IPV6_SRCRT_TYPE_2:
547 if (accept_source_route < 0)
549 /* Silently discard invalid RTH type 2 */
550 if (hdr->hdrlen != 2 || hdr->segments_left != 1) {
551 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
562 * This is the routing header forwarding algorithm from
566 n = hdr->hdrlen >> 1;
568 if (hdr->segments_left > n) {
569 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
570 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
571 ((&hdr->segments_left) -
572 skb_network_header(skb)));
576 /* We are about to mangle packet header. Be careful!
577 Do not damage packets queued somewhere.
579 if (skb_cloned(skb)) {
580 /* the copy is a forwarded packet */
581 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) {
582 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
583 IPSTATS_MIB_OUTDISCARDS);
587 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb);
590 if (skb->ip_summed == CHECKSUM_COMPLETE)
591 skb->ip_summed = CHECKSUM_NONE;
593 i = n - --hdr->segments_left;
595 rthdr = (struct rt0_hdr *) hdr;
600 #if IS_ENABLED(CONFIG_IPV6_MIP6)
601 case IPV6_SRCRT_TYPE_2:
602 if (xfrm6_input_addr(skb, (xfrm_address_t *)addr,
603 (xfrm_address_t *)&ipv6_hdr(skb)->saddr,
604 IPPROTO_ROUTING) < 0) {
605 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
609 if (!ipv6_chk_home_addr(dev_net(skb_dst(skb)->dev), addr)) {
610 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
620 if (ipv6_addr_is_multicast(addr)) {
621 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
627 *addr = ipv6_hdr(skb)->daddr;
628 ipv6_hdr(skb)->daddr = daddr;
631 ip6_route_input(skb);
632 if (skb_dst(skb)->error) {
633 skb_push(skb, skb->data - skb_network_header(skb));
638 if (skb_dst(skb)->dev->flags&IFF_LOOPBACK) {
639 if (ipv6_hdr(skb)->hop_limit <= 1) {
640 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
641 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
646 ipv6_hdr(skb)->hop_limit--;
650 skb_push(skb, skb->data - skb_network_header(skb));
655 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
656 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
657 (&hdr->type) - skb_network_header(skb));
661 static const struct inet6_protocol rthdr_protocol = {
662 .handler = ipv6_rthdr_rcv,
663 .flags = INET6_PROTO_NOPOLICY,
666 static const struct inet6_protocol destopt_protocol = {
667 .handler = ipv6_destopt_rcv,
668 .flags = INET6_PROTO_NOPOLICY,
671 static const struct inet6_protocol nodata_protocol = {
672 .handler = dst_discard,
673 .flags = INET6_PROTO_NOPOLICY,
676 int __init ipv6_exthdrs_init(void)
680 ret = inet6_add_protocol(&rthdr_protocol, IPPROTO_ROUTING);
684 ret = inet6_add_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
688 ret = inet6_add_protocol(&nodata_protocol, IPPROTO_NONE);
695 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
697 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING);
701 void ipv6_exthdrs_exit(void)
703 inet6_del_protocol(&nodata_protocol, IPPROTO_NONE);
704 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
705 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING);
708 /**********************************
710 **********************************/
713 * Note: we cannot rely on skb_dst(skb) before we assign it in ip6_route_input().
715 static inline struct inet6_dev *ipv6_skb_idev(struct sk_buff *skb)
717 return skb_dst(skb) ? ip6_dst_idev(skb_dst(skb)) : __in6_dev_get(skb->dev);
720 static inline struct net *ipv6_skb_net(struct sk_buff *skb)
722 return skb_dst(skb) ? dev_net(skb_dst(skb)->dev) : dev_net(skb->dev);
725 /* Router Alert as of RFC 2711 */
727 static bool ipv6_hop_ra(struct sk_buff *skb, int optoff)
729 const unsigned char *nh = skb_network_header(skb);
731 if (nh[optoff + 1] == 2) {
732 IP6CB(skb)->flags |= IP6SKB_ROUTERALERT;
733 memcpy(&IP6CB(skb)->ra, nh + optoff + 2, sizeof(IP6CB(skb)->ra));
736 net_dbg_ratelimited("ipv6_hop_ra: wrong RA length %d\n",
744 static bool ipv6_hop_jumbo(struct sk_buff *skb, int optoff)
746 const unsigned char *nh = skb_network_header(skb);
747 struct inet6_dev *idev = __in6_dev_get_safely(skb->dev);
748 struct net *net = ipv6_skb_net(skb);
751 if (nh[optoff + 1] != 4 || (optoff & 3) != 2) {
752 net_dbg_ratelimited("ipv6_hop_jumbo: wrong jumbo opt length/alignment %d\n",
754 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
758 pkt_len = ntohl(*(__be32 *)(nh + optoff + 2));
759 if (pkt_len <= IPV6_MAXPLEN) {
760 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
761 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff+2);
764 if (ipv6_hdr(skb)->payload_len) {
765 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
766 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff);
770 if (pkt_len > skb->len - sizeof(struct ipv6hdr)) {
771 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INTRUNCATEDPKTS);
775 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr)))
778 IP6CB(skb)->flags |= IP6SKB_JUMBOGRAM;
786 /* CALIPSO RFC 5570 */
788 static bool ipv6_hop_calipso(struct sk_buff *skb, int optoff)
790 const unsigned char *nh = skb_network_header(skb);
792 if (nh[optoff + 1] < 8)
795 if (nh[optoff + 6] * 4 + 8 > nh[optoff + 1])
798 if (!calipso_validate(skb, nh + optoff))
808 static const struct tlvtype_proc tlvprochopopt_lst[] = {
810 .type = IPV6_TLV_ROUTERALERT,
814 .type = IPV6_TLV_JUMBO,
815 .func = ipv6_hop_jumbo,
818 .type = IPV6_TLV_CALIPSO,
819 .func = ipv6_hop_calipso,
824 int ipv6_parse_hopopts(struct sk_buff *skb)
826 struct inet6_skb_parm *opt = IP6CB(skb);
827 struct net *net = dev_net(skb->dev);
831 * skb_network_header(skb) is equal to skb->data, and
832 * skb_network_header_len(skb) is always equal to
833 * sizeof(struct ipv6hdr) by definition of
834 * hop-by-hop options.
836 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + 8) ||
837 !pskb_may_pull(skb, (sizeof(struct ipv6hdr) +
838 ((skb_transport_header(skb)[1] + 1) << 3)))) {
844 extlen = (skb_transport_header(skb)[1] + 1) << 3;
845 if (extlen > net->ipv6.sysctl.max_hbh_opts_len)
848 opt->flags |= IP6SKB_HOPBYHOP;
849 if (ip6_parse_tlv(tlvprochopopt_lst, skb,
850 net->ipv6.sysctl.max_hbh_opts_cnt)) {
851 skb->transport_header += extlen;
853 opt->nhoff = sizeof(struct ipv6hdr);
860 * Creating outbound headers.
862 * "build" functions work when skb is filled from head to tail (datagram)
863 * "push" functions work when headers are added from tail to head (tcp)
865 * In both cases we assume, that caller reserved enough room
869 static void ipv6_push_rthdr0(struct sk_buff *skb, u8 *proto,
870 struct ipv6_rt_hdr *opt,
871 struct in6_addr **addr_p, struct in6_addr *saddr)
873 struct rt0_hdr *phdr, *ihdr;
876 ihdr = (struct rt0_hdr *) opt;
878 phdr = skb_push(skb, (ihdr->rt_hdr.hdrlen + 1) << 3);
879 memcpy(phdr, ihdr, sizeof(struct rt0_hdr));
881 hops = ihdr->rt_hdr.hdrlen >> 1;
884 memcpy(phdr->addr, ihdr->addr + 1,
885 (hops - 1) * sizeof(struct in6_addr));
887 phdr->addr[hops - 1] = **addr_p;
888 *addr_p = ihdr->addr;
890 phdr->rt_hdr.nexthdr = *proto;
891 *proto = NEXTHDR_ROUTING;
894 static void ipv6_push_rthdr4(struct sk_buff *skb, u8 *proto,
895 struct ipv6_rt_hdr *opt,
896 struct in6_addr **addr_p, struct in6_addr *saddr)
898 struct ipv6_sr_hdr *sr_phdr, *sr_ihdr;
901 sr_ihdr = (struct ipv6_sr_hdr *)opt;
902 plen = (sr_ihdr->hdrlen + 1) << 3;
904 sr_phdr = skb_push(skb, plen);
905 memcpy(sr_phdr, sr_ihdr, sizeof(struct ipv6_sr_hdr));
907 hops = sr_ihdr->first_segment + 1;
908 memcpy(sr_phdr->segments + 1, sr_ihdr->segments + 1,
909 (hops - 1) * sizeof(struct in6_addr));
911 sr_phdr->segments[0] = **addr_p;
912 *addr_p = &sr_ihdr->segments[sr_ihdr->segments_left];
914 if (sr_ihdr->hdrlen > hops * 2) {
915 int tlvs_offset, tlvs_length;
917 tlvs_offset = (1 + hops * 2) << 3;
918 tlvs_length = (sr_ihdr->hdrlen - hops * 2) << 3;
919 memcpy((char *)sr_phdr + tlvs_offset,
920 (char *)sr_ihdr + tlvs_offset, tlvs_length);
923 #ifdef CONFIG_IPV6_SEG6_HMAC
924 if (sr_has_hmac(sr_phdr)) {
925 struct net *net = NULL;
928 net = dev_net(skb->dev);
930 net = sock_net(skb->sk);
935 seg6_push_hmac(net, saddr, sr_phdr);
939 sr_phdr->nexthdr = *proto;
940 *proto = NEXTHDR_ROUTING;
943 static void ipv6_push_rthdr(struct sk_buff *skb, u8 *proto,
944 struct ipv6_rt_hdr *opt,
945 struct in6_addr **addr_p, struct in6_addr *saddr)
948 case IPV6_SRCRT_TYPE_0:
949 case IPV6_SRCRT_STRICT:
950 case IPV6_SRCRT_TYPE_2:
951 ipv6_push_rthdr0(skb, proto, opt, addr_p, saddr);
953 case IPV6_SRCRT_TYPE_4:
954 ipv6_push_rthdr4(skb, proto, opt, addr_p, saddr);
961 static void ipv6_push_exthdr(struct sk_buff *skb, u8 *proto, u8 type, struct ipv6_opt_hdr *opt)
963 struct ipv6_opt_hdr *h = skb_push(skb, ipv6_optlen(opt));
965 memcpy(h, opt, ipv6_optlen(opt));
970 void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
972 struct in6_addr **daddr, struct in6_addr *saddr)
975 ipv6_push_rthdr(skb, proto, opt->srcrt, daddr, saddr);
977 * IPV6_RTHDRDSTOPTS is ignored
978 * unless IPV6_RTHDR is set (RFC3542).
981 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst0opt);
984 ipv6_push_exthdr(skb, proto, NEXTHDR_HOP, opt->hopopt);
987 void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, u8 *proto)
990 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst1opt);
992 EXPORT_SYMBOL(ipv6_push_frag_opts);
994 struct ipv6_txoptions *
995 ipv6_dup_options(struct sock *sk, struct ipv6_txoptions *opt)
997 struct ipv6_txoptions *opt2;
999 opt2 = sock_kmalloc(sk, opt->tot_len, GFP_ATOMIC);
1001 long dif = (char *)opt2 - (char *)opt;
1002 memcpy(opt2, opt, opt->tot_len);
1004 *((char **)&opt2->hopopt) += dif;
1006 *((char **)&opt2->dst0opt) += dif;
1008 *((char **)&opt2->dst1opt) += dif;
1010 *((char **)&opt2->srcrt) += dif;
1011 refcount_set(&opt2->refcnt, 1);
1015 EXPORT_SYMBOL_GPL(ipv6_dup_options);
1017 static void ipv6_renew_option(int renewtype,
1018 struct ipv6_opt_hdr **dest,
1019 struct ipv6_opt_hdr *old,
1020 struct ipv6_opt_hdr *new,
1021 int newtype, char **p)
1023 struct ipv6_opt_hdr *src;
1025 src = (renewtype == newtype ? new : old);
1029 memcpy(*p, src, ipv6_optlen(src));
1030 *dest = (struct ipv6_opt_hdr *)*p;
1031 *p += CMSG_ALIGN(ipv6_optlen(*dest));
1035 * ipv6_renew_options - replace a specific ext hdr with a new one.
1037 * @sk: sock from which to allocate memory
1038 * @opt: original options
1039 * @newtype: option type to replace in @opt
1040 * @newopt: new option of type @newtype to replace (user-mem)
1041 * @newoptlen: length of @newopt
1043 * Returns a new set of options which is a copy of @opt with the
1044 * option type @newtype replaced with @newopt.
1046 * @opt may be NULL, in which case a new set of options is returned
1047 * containing just @newopt.
1049 * @newopt may be NULL, in which case the specified option type is
1050 * not copied into the new set of options.
1052 * The new set of options is allocated from the socket option memory
1055 struct ipv6_txoptions *
1056 ipv6_renew_options(struct sock *sk, struct ipv6_txoptions *opt,
1057 int newtype, struct ipv6_opt_hdr *newopt)
1061 struct ipv6_txoptions *opt2;
1064 if (newtype != IPV6_HOPOPTS && opt->hopopt)
1065 tot_len += CMSG_ALIGN(ipv6_optlen(opt->hopopt));
1066 if (newtype != IPV6_RTHDRDSTOPTS && opt->dst0opt)
1067 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst0opt));
1068 if (newtype != IPV6_RTHDR && opt->srcrt)
1069 tot_len += CMSG_ALIGN(ipv6_optlen(opt->srcrt));
1070 if (newtype != IPV6_DSTOPTS && opt->dst1opt)
1071 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst1opt));
1075 tot_len += CMSG_ALIGN(ipv6_optlen(newopt));
1080 tot_len += sizeof(*opt2);
1081 opt2 = sock_kmalloc(sk, tot_len, GFP_ATOMIC);
1083 return ERR_PTR(-ENOBUFS);
1085 memset(opt2, 0, tot_len);
1086 refcount_set(&opt2->refcnt, 1);
1087 opt2->tot_len = tot_len;
1088 p = (char *)(opt2 + 1);
1090 ipv6_renew_option(IPV6_HOPOPTS, &opt2->hopopt,
1091 (opt ? opt->hopopt : NULL),
1092 newopt, newtype, &p);
1093 ipv6_renew_option(IPV6_RTHDRDSTOPTS, &opt2->dst0opt,
1094 (opt ? opt->dst0opt : NULL),
1095 newopt, newtype, &p);
1096 ipv6_renew_option(IPV6_RTHDR,
1097 (struct ipv6_opt_hdr **)&opt2->srcrt,
1098 (opt ? (struct ipv6_opt_hdr *)opt->srcrt : NULL),
1099 newopt, newtype, &p);
1100 ipv6_renew_option(IPV6_DSTOPTS, &opt2->dst1opt,
1101 (opt ? opt->dst1opt : NULL),
1102 newopt, newtype, &p);
1104 opt2->opt_nflen = (opt2->hopopt ? ipv6_optlen(opt2->hopopt) : 0) +
1105 (opt2->dst0opt ? ipv6_optlen(opt2->dst0opt) : 0) +
1106 (opt2->srcrt ? ipv6_optlen(opt2->srcrt) : 0);
1107 opt2->opt_flen = (opt2->dst1opt ? ipv6_optlen(opt2->dst1opt) : 0);
1112 struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space,
1113 struct ipv6_txoptions *opt)
1116 * ignore the dest before srcrt unless srcrt is being included.
1119 if (opt && opt->dst0opt && !opt->srcrt) {
1120 if (opt_space != opt) {
1121 memcpy(opt_space, opt, sizeof(*opt_space));
1124 opt->opt_nflen -= ipv6_optlen(opt->dst0opt);
1125 opt->dst0opt = NULL;
1130 EXPORT_SYMBOL_GPL(ipv6_fixup_options);
1133 * fl6_update_dst - update flowi destination address with info given
1134 * by srcrt option, if any.
1136 * @fl6: flowi6 for which daddr is to be updated
1137 * @opt: struct ipv6_txoptions in which to look for srcrt opt
1138 * @orig: copy of original daddr address if modified
1140 * Returns NULL if no txoptions or no srcrt, otherwise returns orig
1141 * and initial value of fl6->daddr set in orig
1143 struct in6_addr *fl6_update_dst(struct flowi6 *fl6,
1144 const struct ipv6_txoptions *opt,
1145 struct in6_addr *orig)
1147 if (!opt || !opt->srcrt)
1152 switch (opt->srcrt->type) {
1153 case IPV6_SRCRT_TYPE_0:
1154 case IPV6_SRCRT_STRICT:
1155 case IPV6_SRCRT_TYPE_2:
1156 fl6->daddr = *((struct rt0_hdr *)opt->srcrt)->addr;
1158 case IPV6_SRCRT_TYPE_4:
1160 struct ipv6_sr_hdr *srh = (struct ipv6_sr_hdr *)opt->srcrt;
1162 fl6->daddr = srh->segments[srh->segments_left];
1171 EXPORT_SYMBOL_GPL(fl6_update_dst);