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)
79 switch ((skb_network_header(skb)[optoff] & 0xC0) >> 6) {
83 case 1: /* drop packet */
86 case 3: /* Send ICMP if not a multicast address and drop packet */
87 /* Actually, it is redundant check. icmp_send
88 will recheck in any case.
90 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr))
92 case 2: /* send ICMP PARM PROB regardless and drop packet */
93 icmpv6_param_prob(skb, ICMPV6_UNK_OPTION, optoff);
101 /* Parse tlv encoded option header (hop-by-hop or destination) */
103 static bool ip6_parse_tlv(const struct tlvtype_proc *procs, struct sk_buff *skb)
105 const struct tlvtype_proc *curr;
106 const unsigned char *nh = skb_network_header(skb);
107 int off = skb_network_header_len(skb);
108 int len = (skb_transport_header(skb)[1] + 1) << 3;
111 if (skb_transport_offset(skb) + len > skb_headlen(skb))
118 int optlen = nh[off + 1] + 2;
130 /* RFC 2460 states that the purpose of PadN is
131 * to align the containing header to multiples
132 * of 8. 7 is therefore the highest valid value.
133 * See also RFC 4942, Section 2.1.9.5.
138 /* RFC 4942 recommends receiving hosts to
139 * actively check PadN payload to contain
142 for (i = 2; i < optlen; i++) {
143 if (nh[off + i] != 0)
148 default: /* Other TLV code so scan list */
151 for (curr = procs; curr->type >= 0; curr++) {
152 if (curr->type == nh[off]) {
153 /* type specific length/alignment
154 checks will be performed in the
156 if (curr->func(skb, off) == false)
161 if (curr->type < 0) {
162 if (ip6_tlvopt_unknown(skb, off) == 0)
179 /*****************************
180 Destination options header.
181 *****************************/
183 #if IS_ENABLED(CONFIG_IPV6_MIP6)
184 static bool ipv6_dest_hao(struct sk_buff *skb, int optoff)
186 struct ipv6_destopt_hao *hao;
187 struct inet6_skb_parm *opt = IP6CB(skb);
188 struct ipv6hdr *ipv6h = ipv6_hdr(skb);
189 struct in6_addr tmp_addr;
193 net_dbg_ratelimited("hao duplicated\n");
196 opt->dsthao = opt->dst1;
199 hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) + optoff);
201 if (hao->length != 16) {
202 net_dbg_ratelimited("hao invalid option length = %d\n",
207 if (!(ipv6_addr_type(&hao->addr) & IPV6_ADDR_UNICAST)) {
208 net_dbg_ratelimited("hao is not an unicast addr: %pI6\n",
213 ret = xfrm6_input_addr(skb, (xfrm_address_t *)&ipv6h->daddr,
214 (xfrm_address_t *)&hao->addr, IPPROTO_DSTOPTS);
215 if (unlikely(ret < 0))
218 if (skb_cloned(skb)) {
219 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
222 /* update all variable using below by copied skbuff */
223 hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) +
225 ipv6h = ipv6_hdr(skb);
228 if (skb->ip_summed == CHECKSUM_COMPLETE)
229 skb->ip_summed = CHECKSUM_NONE;
231 tmp_addr = ipv6h->saddr;
232 ipv6h->saddr = hao->addr;
233 hao->addr = tmp_addr;
235 if (skb->tstamp == 0)
236 __net_timestamp(skb);
246 static const struct tlvtype_proc tlvprocdestopt_lst[] = {
247 #if IS_ENABLED(CONFIG_IPV6_MIP6)
249 .type = IPV6_TLV_HAO,
250 .func = ipv6_dest_hao,
256 static int ipv6_destopt_rcv(struct sk_buff *skb)
258 struct inet6_skb_parm *opt = IP6CB(skb);
259 #if IS_ENABLED(CONFIG_IPV6_MIP6)
262 struct dst_entry *dst = skb_dst(skb);
264 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
265 !pskb_may_pull(skb, (skb_transport_offset(skb) +
266 ((skb_transport_header(skb)[1] + 1) << 3)))) {
267 __IP6_INC_STATS(dev_net(dst->dev), ip6_dst_idev(dst),
268 IPSTATS_MIB_INHDRERRORS);
273 opt->lastopt = opt->dst1 = skb_network_header_len(skb);
274 #if IS_ENABLED(CONFIG_IPV6_MIP6)
278 if (ip6_parse_tlv(tlvprocdestopt_lst, skb)) {
279 skb->transport_header += (skb_transport_header(skb)[1] + 1) << 3;
281 #if IS_ENABLED(CONFIG_IPV6_MIP6)
284 opt->nhoff = opt->dst1;
289 __IP6_INC_STATS(dev_net(dst->dev),
290 ip6_dst_idev(dst), IPSTATS_MIB_INHDRERRORS);
294 static void seg6_update_csum(struct sk_buff *skb)
296 struct ipv6_sr_hdr *hdr;
297 struct in6_addr *addr;
300 /* srh is at transport offset and seg_left is already decremented
301 * but daddr is not yet updated with next segment
304 hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb);
305 addr = hdr->segments + hdr->segments_left;
307 hdr->segments_left++;
308 from = *(__be32 *)hdr;
310 hdr->segments_left--;
313 /* update skb csum with diff resulting from seg_left decrement */
315 update_csum_diff4(skb, from, to);
317 /* compute csum diff between current and next segment and update */
319 update_csum_diff16(skb, (__be32 *)(&ipv6_hdr(skb)->daddr),
323 static int ipv6_srh_rcv(struct sk_buff *skb)
325 struct inet6_skb_parm *opt = IP6CB(skb);
326 struct net *net = dev_net(skb->dev);
327 struct ipv6_sr_hdr *hdr;
328 struct inet6_dev *idev;
329 struct in6_addr *addr;
332 hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb);
334 idev = __in6_dev_get(skb->dev);
336 accept_seg6 = net->ipv6.devconf_all->seg6_enabled;
337 if (accept_seg6 > idev->cnf.seg6_enabled)
338 accept_seg6 = idev->cnf.seg6_enabled;
345 #ifdef CONFIG_IPV6_SEG6_HMAC
346 if (!seg6_hmac_validate_skb(skb)) {
353 if (hdr->segments_left == 0) {
354 if (hdr->nexthdr == NEXTHDR_IPV6) {
355 int offset = (hdr->hdrlen + 1) << 3;
357 skb_postpull_rcsum(skb, skb_network_header(skb),
358 skb_network_header_len(skb));
360 if (!pskb_pull(skb, offset)) {
364 skb_postpull_rcsum(skb, skb_transport_header(skb),
367 skb_reset_network_header(skb);
368 skb_reset_transport_header(skb);
369 skb->encapsulation = 0;
371 __skb_tunnel_rx(skb, skb->dev, net);
377 opt->srcrt = skb_network_header_len(skb);
378 opt->lastopt = opt->srcrt;
379 skb->transport_header += (hdr->hdrlen + 1) << 3;
380 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb);
385 if (hdr->segments_left >= (hdr->hdrlen >> 1)) {
386 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
387 IPSTATS_MIB_INHDRERRORS);
388 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
389 ((&hdr->segments_left) -
390 skb_network_header(skb)));
395 if (skb_cloned(skb)) {
396 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) {
397 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
398 IPSTATS_MIB_OUTDISCARDS);
404 hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb);
406 hdr->segments_left--;
407 addr = hdr->segments + hdr->segments_left;
409 skb_push(skb, sizeof(struct ipv6hdr));
411 if (skb->ip_summed == CHECKSUM_COMPLETE)
412 seg6_update_csum(skb);
414 ipv6_hdr(skb)->daddr = *addr;
418 ip6_route_input(skb);
420 if (skb_dst(skb)->error) {
425 if (skb_dst(skb)->dev->flags & IFF_LOOPBACK) {
426 if (ipv6_hdr(skb)->hop_limit <= 1) {
427 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
428 IPSTATS_MIB_INHDRERRORS);
429 icmpv6_send(skb, ICMPV6_TIME_EXCEED,
430 ICMPV6_EXC_HOPLIMIT, 0);
434 ipv6_hdr(skb)->hop_limit--;
436 skb_pull(skb, sizeof(struct ipv6hdr));
445 /********************************
447 ********************************/
449 /* called with rcu_read_lock() */
450 static int ipv6_rthdr_rcv(struct sk_buff *skb)
452 struct inet6_skb_parm *opt = IP6CB(skb);
453 struct in6_addr *addr = NULL;
454 struct in6_addr daddr;
455 struct inet6_dev *idev;
457 struct ipv6_rt_hdr *hdr;
458 struct rt0_hdr *rthdr;
459 struct net *net = dev_net(skb->dev);
460 int accept_source_route = net->ipv6.devconf_all->accept_source_route;
462 idev = __in6_dev_get(skb->dev);
463 if (idev && accept_source_route > idev->cnf.accept_source_route)
464 accept_source_route = idev->cnf.accept_source_route;
466 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
467 !pskb_may_pull(skb, (skb_transport_offset(skb) +
468 ((skb_transport_header(skb)[1] + 1) << 3)))) {
469 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
470 IPSTATS_MIB_INHDRERRORS);
475 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb);
477 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) ||
478 skb->pkt_type != PACKET_HOST) {
479 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
480 IPSTATS_MIB_INADDRERRORS);
485 /* segment routing */
486 if (hdr->type == IPV6_SRCRT_TYPE_4)
487 return ipv6_srh_rcv(skb);
490 if (hdr->segments_left == 0) {
492 #if IS_ENABLED(CONFIG_IPV6_MIP6)
493 case IPV6_SRCRT_TYPE_2:
494 /* Silently discard type 2 header unless it was
498 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
499 IPSTATS_MIB_INADDRERRORS);
509 opt->lastopt = opt->srcrt = skb_network_header_len(skb);
510 skb->transport_header += (hdr->hdrlen + 1) << 3;
511 opt->dst0 = opt->dst1;
513 opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb);
518 #if IS_ENABLED(CONFIG_IPV6_MIP6)
519 case IPV6_SRCRT_TYPE_2:
520 if (accept_source_route < 0)
522 /* Silently discard invalid RTH type 2 */
523 if (hdr->hdrlen != 2 || hdr->segments_left != 1) {
524 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
525 IPSTATS_MIB_INHDRERRORS);
536 * This is the routing header forwarding algorithm from
540 n = hdr->hdrlen >> 1;
542 if (hdr->segments_left > n) {
543 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
544 IPSTATS_MIB_INHDRERRORS);
545 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
546 ((&hdr->segments_left) -
547 skb_network_header(skb)));
551 /* We are about to mangle packet header. Be careful!
552 Do not damage packets queued somewhere.
554 if (skb_cloned(skb)) {
555 /* the copy is a forwarded packet */
556 if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) {
557 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
558 IPSTATS_MIB_OUTDISCARDS);
562 hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb);
565 if (skb->ip_summed == CHECKSUM_COMPLETE)
566 skb->ip_summed = CHECKSUM_NONE;
568 i = n - --hdr->segments_left;
570 rthdr = (struct rt0_hdr *) hdr;
575 #if IS_ENABLED(CONFIG_IPV6_MIP6)
576 case IPV6_SRCRT_TYPE_2:
577 if (xfrm6_input_addr(skb, (xfrm_address_t *)addr,
578 (xfrm_address_t *)&ipv6_hdr(skb)->saddr,
579 IPPROTO_ROUTING) < 0) {
580 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
581 IPSTATS_MIB_INADDRERRORS);
585 if (!ipv6_chk_home_addr(dev_net(skb_dst(skb)->dev), addr)) {
586 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
587 IPSTATS_MIB_INADDRERRORS);
597 if (ipv6_addr_is_multicast(addr)) {
598 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
599 IPSTATS_MIB_INADDRERRORS);
605 *addr = ipv6_hdr(skb)->daddr;
606 ipv6_hdr(skb)->daddr = daddr;
609 ip6_route_input(skb);
610 if (skb_dst(skb)->error) {
611 skb_push(skb, skb->data - skb_network_header(skb));
616 if (skb_dst(skb)->dev->flags&IFF_LOOPBACK) {
617 if (ipv6_hdr(skb)->hop_limit <= 1) {
618 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
619 IPSTATS_MIB_INHDRERRORS);
620 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
625 ipv6_hdr(skb)->hop_limit--;
629 skb_push(skb, skb->data - skb_network_header(skb));
634 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INHDRERRORS);
635 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
636 (&hdr->type) - skb_network_header(skb));
640 static const struct inet6_protocol rthdr_protocol = {
641 .handler = ipv6_rthdr_rcv,
642 .flags = INET6_PROTO_NOPOLICY,
645 static const struct inet6_protocol destopt_protocol = {
646 .handler = ipv6_destopt_rcv,
647 .flags = INET6_PROTO_NOPOLICY,
650 static const struct inet6_protocol nodata_protocol = {
651 .handler = dst_discard,
652 .flags = INET6_PROTO_NOPOLICY,
655 int __init ipv6_exthdrs_init(void)
659 ret = inet6_add_protocol(&rthdr_protocol, IPPROTO_ROUTING);
663 ret = inet6_add_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
667 ret = inet6_add_protocol(&nodata_protocol, IPPROTO_NONE);
674 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
676 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING);
680 void ipv6_exthdrs_exit(void)
682 inet6_del_protocol(&nodata_protocol, IPPROTO_NONE);
683 inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
684 inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING);
687 /**********************************
689 **********************************/
692 * Note: we cannot rely on skb_dst(skb) before we assign it in ip6_route_input().
694 static inline struct inet6_dev *ipv6_skb_idev(struct sk_buff *skb)
696 return skb_dst(skb) ? ip6_dst_idev(skb_dst(skb)) : __in6_dev_get(skb->dev);
699 static inline struct net *ipv6_skb_net(struct sk_buff *skb)
701 return skb_dst(skb) ? dev_net(skb_dst(skb)->dev) : dev_net(skb->dev);
704 /* Router Alert as of RFC 2711 */
706 static bool ipv6_hop_ra(struct sk_buff *skb, int optoff)
708 const unsigned char *nh = skb_network_header(skb);
710 if (nh[optoff + 1] == 2) {
711 IP6CB(skb)->flags |= IP6SKB_ROUTERALERT;
712 memcpy(&IP6CB(skb)->ra, nh + optoff + 2, sizeof(IP6CB(skb)->ra));
715 net_dbg_ratelimited("ipv6_hop_ra: wrong RA length %d\n",
723 static bool ipv6_hop_jumbo(struct sk_buff *skb, int optoff)
725 const unsigned char *nh = skb_network_header(skb);
726 struct net *net = ipv6_skb_net(skb);
729 if (nh[optoff + 1] != 4 || (optoff & 3) != 2) {
730 net_dbg_ratelimited("ipv6_hop_jumbo: wrong jumbo opt length/alignment %d\n",
732 __IP6_INC_STATS(net, ipv6_skb_idev(skb),
733 IPSTATS_MIB_INHDRERRORS);
737 pkt_len = ntohl(*(__be32 *)(nh + optoff + 2));
738 if (pkt_len <= IPV6_MAXPLEN) {
739 __IP6_INC_STATS(net, ipv6_skb_idev(skb),
740 IPSTATS_MIB_INHDRERRORS);
741 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff+2);
744 if (ipv6_hdr(skb)->payload_len) {
745 __IP6_INC_STATS(net, ipv6_skb_idev(skb),
746 IPSTATS_MIB_INHDRERRORS);
747 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff);
751 if (pkt_len > skb->len - sizeof(struct ipv6hdr)) {
752 __IP6_INC_STATS(net, ipv6_skb_idev(skb),
753 IPSTATS_MIB_INTRUNCATEDPKTS);
757 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr)))
767 /* CALIPSO RFC 5570 */
769 static bool ipv6_hop_calipso(struct sk_buff *skb, int optoff)
771 const unsigned char *nh = skb_network_header(skb);
773 if (nh[optoff + 1] < 8)
776 if (nh[optoff + 6] * 4 + 8 > nh[optoff + 1])
779 if (!calipso_validate(skb, nh + optoff))
789 static const struct tlvtype_proc tlvprochopopt_lst[] = {
791 .type = IPV6_TLV_ROUTERALERT,
795 .type = IPV6_TLV_JUMBO,
796 .func = ipv6_hop_jumbo,
799 .type = IPV6_TLV_CALIPSO,
800 .func = ipv6_hop_calipso,
805 int ipv6_parse_hopopts(struct sk_buff *skb)
807 struct inet6_skb_parm *opt = IP6CB(skb);
810 * skb_network_header(skb) is equal to skb->data, and
811 * skb_network_header_len(skb) is always equal to
812 * sizeof(struct ipv6hdr) by definition of
813 * hop-by-hop options.
815 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + 8) ||
816 !pskb_may_pull(skb, (sizeof(struct ipv6hdr) +
817 ((skb_transport_header(skb)[1] + 1) << 3)))) {
822 opt->flags |= IP6SKB_HOPBYHOP;
823 if (ip6_parse_tlv(tlvprochopopt_lst, skb)) {
824 skb->transport_header += (skb_transport_header(skb)[1] + 1) << 3;
826 opt->nhoff = sizeof(struct ipv6hdr);
833 * Creating outbound headers.
835 * "build" functions work when skb is filled from head to tail (datagram)
836 * "push" functions work when headers are added from tail to head (tcp)
838 * In both cases we assume, that caller reserved enough room
842 static void ipv6_push_rthdr0(struct sk_buff *skb, u8 *proto,
843 struct ipv6_rt_hdr *opt,
844 struct in6_addr **addr_p, struct in6_addr *saddr)
846 struct rt0_hdr *phdr, *ihdr;
849 ihdr = (struct rt0_hdr *) opt;
851 phdr = (struct rt0_hdr *) skb_push(skb, (ihdr->rt_hdr.hdrlen + 1) << 3);
852 memcpy(phdr, ihdr, sizeof(struct rt0_hdr));
854 hops = ihdr->rt_hdr.hdrlen >> 1;
857 memcpy(phdr->addr, ihdr->addr + 1,
858 (hops - 1) * sizeof(struct in6_addr));
860 phdr->addr[hops - 1] = **addr_p;
861 *addr_p = ihdr->addr;
863 phdr->rt_hdr.nexthdr = *proto;
864 *proto = NEXTHDR_ROUTING;
867 static void ipv6_push_rthdr4(struct sk_buff *skb, u8 *proto,
868 struct ipv6_rt_hdr *opt,
869 struct in6_addr **addr_p, struct in6_addr *saddr)
871 struct ipv6_sr_hdr *sr_phdr, *sr_ihdr;
874 sr_ihdr = (struct ipv6_sr_hdr *)opt;
875 plen = (sr_ihdr->hdrlen + 1) << 3;
877 sr_phdr = (struct ipv6_sr_hdr *)skb_push(skb, plen);
878 memcpy(sr_phdr, sr_ihdr, sizeof(struct ipv6_sr_hdr));
880 hops = sr_ihdr->first_segment + 1;
881 memcpy(sr_phdr->segments + 1, sr_ihdr->segments + 1,
882 (hops - 1) * sizeof(struct in6_addr));
884 sr_phdr->segments[0] = **addr_p;
885 *addr_p = &sr_ihdr->segments[hops - 1];
887 #ifdef CONFIG_IPV6_SEG6_HMAC
888 if (sr_has_hmac(sr_phdr)) {
889 struct net *net = NULL;
892 net = dev_net(skb->dev);
894 net = sock_net(skb->sk);
899 seg6_push_hmac(net, saddr, sr_phdr);
903 sr_phdr->nexthdr = *proto;
904 *proto = NEXTHDR_ROUTING;
907 static void ipv6_push_rthdr(struct sk_buff *skb, u8 *proto,
908 struct ipv6_rt_hdr *opt,
909 struct in6_addr **addr_p, struct in6_addr *saddr)
912 case IPV6_SRCRT_TYPE_0:
913 ipv6_push_rthdr0(skb, proto, opt, addr_p, saddr);
915 case IPV6_SRCRT_TYPE_4:
916 ipv6_push_rthdr4(skb, proto, opt, addr_p, saddr);
923 static void ipv6_push_exthdr(struct sk_buff *skb, u8 *proto, u8 type, struct ipv6_opt_hdr *opt)
925 struct ipv6_opt_hdr *h = (struct ipv6_opt_hdr *)skb_push(skb, ipv6_optlen(opt));
927 memcpy(h, opt, ipv6_optlen(opt));
932 void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
934 struct in6_addr **daddr, struct in6_addr *saddr)
937 ipv6_push_rthdr(skb, proto, opt->srcrt, daddr, saddr);
939 * IPV6_RTHDRDSTOPTS is ignored
940 * unless IPV6_RTHDR is set (RFC3542).
943 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst0opt);
946 ipv6_push_exthdr(skb, proto, NEXTHDR_HOP, opt->hopopt);
948 EXPORT_SYMBOL(ipv6_push_nfrag_opts);
950 void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, u8 *proto)
953 ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst1opt);
956 struct ipv6_txoptions *
957 ipv6_dup_options(struct sock *sk, struct ipv6_txoptions *opt)
959 struct ipv6_txoptions *opt2;
961 opt2 = sock_kmalloc(sk, opt->tot_len, GFP_ATOMIC);
963 long dif = (char *)opt2 - (char *)opt;
964 memcpy(opt2, opt, opt->tot_len);
966 *((char **)&opt2->hopopt) += dif;
968 *((char **)&opt2->dst0opt) += dif;
970 *((char **)&opt2->dst1opt) += dif;
972 *((char **)&opt2->srcrt) += dif;
973 atomic_set(&opt2->refcnt, 1);
977 EXPORT_SYMBOL_GPL(ipv6_dup_options);
979 static int ipv6_renew_option(void *ohdr,
980 struct ipv6_opt_hdr __user *newopt, int newoptlen,
982 struct ipv6_opt_hdr **hdr,
987 memcpy(*p, ohdr, ipv6_optlen((struct ipv6_opt_hdr *)ohdr));
988 *hdr = (struct ipv6_opt_hdr *)*p;
989 *p += CMSG_ALIGN(ipv6_optlen(*hdr));
993 if (copy_from_user(*p, newopt, newoptlen))
995 *hdr = (struct ipv6_opt_hdr *)*p;
996 if (ipv6_optlen(*hdr) > newoptlen)
998 *p += CMSG_ALIGN(newoptlen);
1005 * ipv6_renew_options - replace a specific ext hdr with a new one.
1007 * @sk: sock from which to allocate memory
1008 * @opt: original options
1009 * @newtype: option type to replace in @opt
1010 * @newopt: new option of type @newtype to replace (user-mem)
1011 * @newoptlen: length of @newopt
1013 * Returns a new set of options which is a copy of @opt with the
1014 * option type @newtype replaced with @newopt.
1016 * @opt may be NULL, in which case a new set of options is returned
1017 * containing just @newopt.
1019 * @newopt may be NULL, in which case the specified option type is
1020 * not copied into the new set of options.
1022 * The new set of options is allocated from the socket option memory
1025 struct ipv6_txoptions *
1026 ipv6_renew_options(struct sock *sk, struct ipv6_txoptions *opt,
1028 struct ipv6_opt_hdr __user *newopt, int newoptlen)
1032 struct ipv6_txoptions *opt2;
1036 if (newtype != IPV6_HOPOPTS && opt->hopopt)
1037 tot_len += CMSG_ALIGN(ipv6_optlen(opt->hopopt));
1038 if (newtype != IPV6_RTHDRDSTOPTS && opt->dst0opt)
1039 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst0opt));
1040 if (newtype != IPV6_RTHDR && opt->srcrt)
1041 tot_len += CMSG_ALIGN(ipv6_optlen(opt->srcrt));
1042 if (newtype != IPV6_DSTOPTS && opt->dst1opt)
1043 tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst1opt));
1046 if (newopt && newoptlen)
1047 tot_len += CMSG_ALIGN(newoptlen);
1052 tot_len += sizeof(*opt2);
1053 opt2 = sock_kmalloc(sk, tot_len, GFP_ATOMIC);
1055 return ERR_PTR(-ENOBUFS);
1057 memset(opt2, 0, tot_len);
1058 atomic_set(&opt2->refcnt, 1);
1059 opt2->tot_len = tot_len;
1060 p = (char *)(opt2 + 1);
1062 err = ipv6_renew_option(opt ? opt->hopopt : NULL, newopt, newoptlen,
1063 newtype != IPV6_HOPOPTS,
1068 err = ipv6_renew_option(opt ? opt->dst0opt : NULL, newopt, newoptlen,
1069 newtype != IPV6_RTHDRDSTOPTS,
1070 &opt2->dst0opt, &p);
1074 err = ipv6_renew_option(opt ? opt->srcrt : NULL, newopt, newoptlen,
1075 newtype != IPV6_RTHDR,
1076 (struct ipv6_opt_hdr **)&opt2->srcrt, &p);
1080 err = ipv6_renew_option(opt ? opt->dst1opt : NULL, newopt, newoptlen,
1081 newtype != IPV6_DSTOPTS,
1082 &opt2->dst1opt, &p);
1086 opt2->opt_nflen = (opt2->hopopt ? ipv6_optlen(opt2->hopopt) : 0) +
1087 (opt2->dst0opt ? ipv6_optlen(opt2->dst0opt) : 0) +
1088 (opt2->srcrt ? ipv6_optlen(opt2->srcrt) : 0);
1089 opt2->opt_flen = (opt2->dst1opt ? ipv6_optlen(opt2->dst1opt) : 0);
1093 sock_kfree_s(sk, opt2, opt2->tot_len);
1094 return ERR_PTR(err);
1098 * ipv6_renew_options_kern - replace a specific ext hdr with a new one.
1100 * @sk: sock from which to allocate memory
1101 * @opt: original options
1102 * @newtype: option type to replace in @opt
1103 * @newopt: new option of type @newtype to replace (kernel-mem)
1104 * @newoptlen: length of @newopt
1106 * See ipv6_renew_options(). The difference is that @newopt is
1107 * kernel memory, rather than user memory.
1109 struct ipv6_txoptions *
1110 ipv6_renew_options_kern(struct sock *sk, struct ipv6_txoptions *opt,
1111 int newtype, struct ipv6_opt_hdr *newopt,
1114 struct ipv6_txoptions *ret_val;
1115 const mm_segment_t old_fs = get_fs();
1118 ret_val = ipv6_renew_options(sk, opt, newtype,
1119 (struct ipv6_opt_hdr __user *)newopt,
1125 struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space,
1126 struct ipv6_txoptions *opt)
1129 * ignore the dest before srcrt unless srcrt is being included.
1132 if (opt && opt->dst0opt && !opt->srcrt) {
1133 if (opt_space != opt) {
1134 memcpy(opt_space, opt, sizeof(*opt_space));
1137 opt->opt_nflen -= ipv6_optlen(opt->dst0opt);
1138 opt->dst0opt = NULL;
1143 EXPORT_SYMBOL_GPL(ipv6_fixup_options);
1146 * fl6_update_dst - update flowi destination address with info given
1147 * by srcrt option, if any.
1149 * @fl6: flowi6 for which daddr is to be updated
1150 * @opt: struct ipv6_txoptions in which to look for srcrt opt
1151 * @orig: copy of original daddr address if modified
1153 * Returns NULL if no txoptions or no srcrt, otherwise returns orig
1154 * and initial value of fl6->daddr set in orig
1156 struct in6_addr *fl6_update_dst(struct flowi6 *fl6,
1157 const struct ipv6_txoptions *opt,
1158 struct in6_addr *orig)
1160 if (!opt || !opt->srcrt)
1165 switch (opt->srcrt->type) {
1166 case IPV6_SRCRT_TYPE_0:
1167 fl6->daddr = *((struct rt0_hdr *)opt->srcrt)->addr;
1169 case IPV6_SRCRT_TYPE_4:
1171 struct ipv6_sr_hdr *srh = (struct ipv6_sr_hdr *)opt->srcrt;
1173 fl6->daddr = srh->segments[srh->first_segment];
1182 EXPORT_SYMBOL_GPL(fl6_update_dst);