3 * Linux INET6 implementation
6 * Pedro Roque <roque@di.fc.ul.pt>
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
14 #include <linux/capability.h>
15 #include <linux/errno.h>
16 #include <linux/types.h>
17 #include <linux/kernel.h>
18 #include <linux/interrupt.h>
19 #include <linux/socket.h>
20 #include <linux/sockios.h>
21 #include <linux/in6.h>
22 #include <linux/ipv6.h>
23 #include <linux/route.h>
24 #include <linux/slab.h>
27 #include <net/ndisc.h>
28 #include <net/addrconf.h>
29 #include <net/transp_v6.h>
30 #include <net/ip6_route.h>
31 #include <net/tcp_states.h>
33 #include <linux/errqueue.h>
34 #include <asm/uaccess.h>
36 static inline int ipv6_mapped_addr_any(const struct in6_addr *a)
38 return (ipv6_addr_v4mapped(a) && (a->s6_addr32[3] == 0));
41 static int __ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
43 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
44 struct inet_sock *inet = inet_sk(sk);
45 struct ipv6_pinfo *np = inet6_sk(sk);
46 struct in6_addr *daddr, *final_p, final;
47 struct dst_entry *dst;
49 struct ip6_flowlabel *flowlabel = NULL;
50 struct ipv6_txoptions *opt;
54 if (usin->sin6_family == AF_INET) {
55 if (__ipv6_only_sock(sk))
57 err = __ip4_datagram_connect(sk, uaddr, addr_len);
61 if (addr_len < SIN6_LEN_RFC2133)
64 if (usin->sin6_family != AF_INET6)
67 memset(&fl6, 0, sizeof(fl6));
69 fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
70 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
71 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
72 if (flowlabel == NULL)
74 ipv6_addr_copy(&usin->sin6_addr, &flowlabel->dst);
78 addr_type = ipv6_addr_type(&usin->sin6_addr);
80 if (addr_type == IPV6_ADDR_ANY) {
84 usin->sin6_addr.s6_addr[15] = 0x01;
87 daddr = &usin->sin6_addr;
89 if (addr_type == IPV6_ADDR_MAPPED) {
90 struct sockaddr_in sin;
92 if (__ipv6_only_sock(sk)) {
96 sin.sin_family = AF_INET;
97 sin.sin_addr.s_addr = daddr->s6_addr32[3];
98 sin.sin_port = usin->sin6_port;
100 err = __ip4_datagram_connect(sk,
101 (struct sockaddr *) &sin,
108 ipv6_addr_set_v4mapped(inet->inet_daddr, &np->daddr);
110 if (ipv6_addr_any(&np->saddr) ||
111 ipv6_mapped_addr_any(&np->saddr))
112 ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
114 if (ipv6_addr_any(&np->rcv_saddr) ||
115 ipv6_mapped_addr_any(&np->rcv_saddr)) {
116 ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
118 if (sk->sk_prot->rehash)
119 sk->sk_prot->rehash(sk);
125 if (addr_type&IPV6_ADDR_LINKLOCAL) {
126 if (addr_len >= sizeof(struct sockaddr_in6) &&
127 usin->sin6_scope_id) {
128 if (sk->sk_bound_dev_if &&
129 sk->sk_bound_dev_if != usin->sin6_scope_id) {
133 sk->sk_bound_dev_if = usin->sin6_scope_id;
136 if (!sk->sk_bound_dev_if && (addr_type & IPV6_ADDR_MULTICAST))
137 sk->sk_bound_dev_if = np->mcast_oif;
139 /* Connect to link-local address requires an interface */
140 if (!sk->sk_bound_dev_if) {
146 ipv6_addr_copy(&np->daddr, daddr);
147 np->flow_label = fl6.flowlabel;
149 inet->inet_dport = usin->sin6_port;
152 * Check for a route to destination an obtain the
153 * destination cache for it.
156 fl6.flowi6_proto = sk->sk_protocol;
157 ipv6_addr_copy(&fl6.daddr, &np->daddr);
158 ipv6_addr_copy(&fl6.saddr, &np->saddr);
159 fl6.flowi6_oif = sk->sk_bound_dev_if;
160 fl6.flowi6_mark = sk->sk_mark;
161 fl6.fl6_dport = inet->inet_dport;
162 fl6.fl6_sport = inet->inet_sport;
164 if (!fl6.flowi6_oif && (addr_type&IPV6_ADDR_MULTICAST))
165 fl6.flowi6_oif = np->mcast_oif;
167 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
169 opt = flowlabel ? flowlabel->opt : np->opt;
170 final_p = fl6_update_dst(&fl6, opt, &final);
172 dst = ip6_dst_lookup_flow(sk, &fl6, final_p, true);
179 /* source address lookup done in ip6_dst_lookup */
181 if (ipv6_addr_any(&np->saddr))
182 ipv6_addr_copy(&np->saddr, &fl6.saddr);
184 if (ipv6_addr_any(&np->rcv_saddr)) {
185 ipv6_addr_copy(&np->rcv_saddr, &fl6.saddr);
186 inet->inet_rcv_saddr = LOOPBACK4_IPV6;
187 if (sk->sk_prot->rehash)
188 sk->sk_prot->rehash(sk);
191 ip6_dst_store(sk, dst,
192 ipv6_addr_equal(&fl6.daddr, &np->daddr) ?
194 #ifdef CONFIG_IPV6_SUBTREES
195 ipv6_addr_equal(&fl6.saddr, &np->saddr) ?
200 sk->sk_state = TCP_ESTABLISHED;
202 fl6_sock_release(flowlabel);
206 int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
211 res = __ip6_datagram_connect(sk, uaddr, addr_len);
216 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
217 __be16 port, u32 info, u8 *payload)
219 struct ipv6_pinfo *np = inet6_sk(sk);
220 struct icmp6hdr *icmph = icmp6_hdr(skb);
221 struct sock_exterr_skb *serr;
226 skb = skb_clone(skb, GFP_ATOMIC);
230 skb->protocol = htons(ETH_P_IPV6);
232 serr = SKB_EXT_ERR(skb);
233 serr->ee.ee_errno = err;
234 serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
235 serr->ee.ee_type = icmph->icmp6_type;
236 serr->ee.ee_code = icmph->icmp6_code;
238 serr->ee.ee_info = info;
239 serr->ee.ee_data = 0;
240 serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
241 skb_network_header(skb);
244 __skb_pull(skb, payload - skb->data);
245 skb_reset_transport_header(skb);
247 if (sock_queue_err_skb(sk, skb))
251 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info)
253 struct ipv6_pinfo *np = inet6_sk(sk);
254 struct sock_exterr_skb *serr;
261 skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
265 skb->protocol = htons(ETH_P_IPV6);
267 skb_put(skb, sizeof(struct ipv6hdr));
268 skb_reset_network_header(skb);
270 ipv6_addr_copy(&iph->daddr, &fl6->daddr);
272 serr = SKB_EXT_ERR(skb);
273 serr->ee.ee_errno = err;
274 serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
275 serr->ee.ee_type = 0;
276 serr->ee.ee_code = 0;
278 serr->ee.ee_info = info;
279 serr->ee.ee_data = 0;
280 serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
281 serr->port = fl6->fl6_dport;
283 __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
284 skb_reset_transport_header(skb);
286 if (sock_queue_err_skb(sk, skb))
290 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
292 struct ipv6_pinfo *np = inet6_sk(sk);
295 struct ip6_mtuinfo *mtu_info;
297 if (!np->rxopt.bits.rxpmtu)
300 skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
304 skb_put(skb, sizeof(struct ipv6hdr));
305 skb_reset_network_header(skb);
307 ipv6_addr_copy(&iph->daddr, &fl6->daddr);
309 mtu_info = IP6CBMTU(skb);
311 mtu_info->ip6m_mtu = mtu;
312 mtu_info->ip6m_addr.sin6_family = AF_INET6;
313 mtu_info->ip6m_addr.sin6_port = 0;
314 mtu_info->ip6m_addr.sin6_flowinfo = 0;
315 mtu_info->ip6m_addr.sin6_scope_id = fl6->flowi6_oif;
316 ipv6_addr_copy(&mtu_info->ip6m_addr.sin6_addr, &ipv6_hdr(skb)->daddr);
318 __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
319 skb_reset_transport_header(skb);
321 skb = xchg(&np->rxpmtu, skb);
326 * Handle MSG_ERRQUEUE
328 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
330 struct ipv6_pinfo *np = inet6_sk(sk);
331 struct sock_exterr_skb *serr;
332 struct sk_buff *skb, *skb2;
333 struct sockaddr_in6 *sin;
335 struct sock_extended_err ee;
336 struct sockaddr_in6 offender;
342 skb = skb_dequeue(&sk->sk_error_queue);
348 msg->msg_flags |= MSG_TRUNC;
351 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
355 sock_recv_timestamp(msg, sk, skb);
357 serr = SKB_EXT_ERR(skb);
359 sin = (struct sockaddr_in6 *)msg->msg_name;
361 const unsigned char *nh = skb_network_header(skb);
362 sin->sin6_family = AF_INET6;
363 sin->sin6_flowinfo = 0;
364 sin->sin6_port = serr->port;
365 sin->sin6_scope_id = 0;
366 if (skb->protocol == htons(ETH_P_IPV6)) {
367 ipv6_addr_copy(&sin->sin6_addr,
368 (struct in6_addr *)(nh + serr->addr_offset));
371 (*(__be32 *)(nh + serr->addr_offset - 24) &
373 if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
374 sin->sin6_scope_id = IP6CB(skb)->iif;
376 ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
379 *addr_len = sizeof(*sin);
382 memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
383 sin = &errhdr.offender;
384 memset(sin, 0, sizeof(*sin));
386 if (serr->ee.ee_origin != SO_EE_ORIGIN_LOCAL) {
387 sin->sin6_family = AF_INET6;
388 if (skb->protocol == htons(ETH_P_IPV6)) {
389 ipv6_addr_copy(&sin->sin6_addr, &ipv6_hdr(skb)->saddr);
391 datagram_recv_ctl(sk, msg, skb);
392 if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
393 sin->sin6_scope_id = IP6CB(skb)->iif;
395 ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
397 if (inet_sk(sk)->cmsg_flags)
398 ip_cmsg_recv(msg, skb);
402 put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
404 /* Now we could try to dump offended packet options */
406 msg->msg_flags |= MSG_ERRQUEUE;
409 /* Reset and regenerate socket error */
410 spin_lock_bh(&sk->sk_error_queue.lock);
412 if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
413 sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
414 spin_unlock_bh(&sk->sk_error_queue.lock);
415 sk->sk_error_report(sk);
417 spin_unlock_bh(&sk->sk_error_queue.lock);
427 * Handle IPV6_RECVPATHMTU
429 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
432 struct ipv6_pinfo *np = inet6_sk(sk);
434 struct sockaddr_in6 *sin;
435 struct ip6_mtuinfo mtu_info;
440 skb = xchg(&np->rxpmtu, NULL);
446 msg->msg_flags |= MSG_TRUNC;
449 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
453 sock_recv_timestamp(msg, sk, skb);
455 memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
457 sin = (struct sockaddr_in6 *)msg->msg_name;
459 sin->sin6_family = AF_INET6;
460 sin->sin6_flowinfo = 0;
462 sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
463 ipv6_addr_copy(&sin->sin6_addr, &mtu_info.ip6m_addr.sin6_addr);
464 *addr_len = sizeof(*sin);
467 put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
478 int datagram_recv_ctl(struct sock *sk, struct msghdr *msg, struct sk_buff *skb)
480 struct ipv6_pinfo *np = inet6_sk(sk);
481 struct inet6_skb_parm *opt = IP6CB(skb);
482 unsigned char *nh = skb_network_header(skb);
484 if (np->rxopt.bits.rxinfo) {
485 struct in6_pktinfo src_info;
487 src_info.ipi6_ifindex = opt->iif;
488 ipv6_addr_copy(&src_info.ipi6_addr, &ipv6_hdr(skb)->daddr);
489 put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);
492 if (np->rxopt.bits.rxhlim) {
493 int hlim = ipv6_hdr(skb)->hop_limit;
494 put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
497 if (np->rxopt.bits.rxtclass) {
498 int tclass = (ntohl(*(__be32 *)ipv6_hdr(skb)) >> 20) & 0xff;
499 put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
502 if (np->rxopt.bits.rxflow && (*(__be32 *)nh & IPV6_FLOWINFO_MASK)) {
503 __be32 flowinfo = *(__be32 *)nh & IPV6_FLOWINFO_MASK;
504 put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
507 /* HbH is allowed only once */
508 if (np->rxopt.bits.hopopts && opt->hop) {
509 u8 *ptr = nh + opt->hop;
510 put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
514 (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
516 * Silly enough, but we need to reparse in order to
517 * report extension headers (except for HbH)
520 * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
521 * (and WILL NOT be) defined because
522 * IPV6_RECVDSTOPTS is more generic. --yoshfuji
524 unsigned int off = sizeof(struct ipv6hdr);
525 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
527 while (off <= opt->lastopt) {
532 case IPPROTO_DSTOPTS:
534 len = (ptr[1] + 1) << 3;
535 if (np->rxopt.bits.dstopts)
536 put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
538 case IPPROTO_ROUTING:
540 len = (ptr[1] + 1) << 3;
541 if (np->rxopt.bits.srcrt)
542 put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
546 len = (ptr[1] + 2) << 2;
550 len = (ptr[1] + 1) << 3;
558 /* socket options in old style */
559 if (np->rxopt.bits.rxoinfo) {
560 struct in6_pktinfo src_info;
562 src_info.ipi6_ifindex = opt->iif;
563 ipv6_addr_copy(&src_info.ipi6_addr, &ipv6_hdr(skb)->daddr);
564 put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
566 if (np->rxopt.bits.rxohlim) {
567 int hlim = ipv6_hdr(skb)->hop_limit;
568 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
570 if (np->rxopt.bits.ohopopts && opt->hop) {
571 u8 *ptr = nh + opt->hop;
572 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
574 if (np->rxopt.bits.odstopts && opt->dst0) {
575 u8 *ptr = nh + opt->dst0;
576 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
578 if (np->rxopt.bits.osrcrt && opt->srcrt) {
579 struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
580 put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
582 if (np->rxopt.bits.odstopts && opt->dst1) {
583 u8 *ptr = nh + opt->dst1;
584 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
586 if (np->rxopt.bits.rxorigdstaddr) {
587 struct sockaddr_in6 sin6;
588 u16 *ports = (u16 *) skb_transport_header(skb);
590 if (skb_transport_offset(skb) + 4 <= skb->len) {
591 /* All current transport protocols have the port numbers in the
592 * first four bytes of the transport header and this function is
593 * written with this assumption in mind.
596 sin6.sin6_family = AF_INET6;
597 ipv6_addr_copy(&sin6.sin6_addr, &ipv6_hdr(skb)->daddr);
598 sin6.sin6_port = ports[1];
599 sin6.sin6_flowinfo = 0;
600 sin6.sin6_scope_id = 0;
602 put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
608 int datagram_send_ctl(struct net *net, struct sock *sk,
609 struct msghdr *msg, struct flowi6 *fl6,
610 struct ipv6_txoptions *opt,
611 int *hlimit, int *tclass, int *dontfrag)
613 struct in6_pktinfo *src_info;
614 struct cmsghdr *cmsg;
615 struct ipv6_rt_hdr *rthdr;
616 struct ipv6_opt_hdr *hdr;
620 for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
623 if (!CMSG_OK(msg, cmsg)) {
628 if (cmsg->cmsg_level != SOL_IPV6)
631 switch (cmsg->cmsg_type) {
633 case IPV6_2292PKTINFO:
635 struct net_device *dev = NULL;
637 if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
642 src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
644 if (src_info->ipi6_ifindex) {
645 if (fl6->flowi6_oif &&
646 src_info->ipi6_ifindex != fl6->flowi6_oif)
648 fl6->flowi6_oif = src_info->ipi6_ifindex;
651 addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
654 if (fl6->flowi6_oif) {
655 dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
660 } else if (addr_type & IPV6_ADDR_LINKLOCAL) {
665 if (addr_type != IPV6_ADDR_ANY) {
666 int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
667 if (!inet_sk(sk)->transparent &&
668 !ipv6_chk_addr(net, &src_info->ipi6_addr,
669 strict ? dev : NULL, 0))
672 ipv6_addr_copy(&fl6->saddr, &src_info->ipi6_addr);
684 if (cmsg->cmsg_len < CMSG_LEN(4)) {
689 if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
690 if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
695 fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
698 case IPV6_2292HOPOPTS:
700 if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
705 hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
706 len = ((hdr->hdrlen + 1) << 3);
707 if (cmsg->cmsg_len < CMSG_LEN(len)) {
711 if (!capable(CAP_NET_RAW)) {
715 opt->opt_nflen += len;
719 case IPV6_2292DSTOPTS:
720 if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
725 hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
726 len = ((hdr->hdrlen + 1) << 3);
727 if (cmsg->cmsg_len < CMSG_LEN(len)) {
731 if (!capable(CAP_NET_RAW)) {
739 opt->opt_flen += len;
744 case IPV6_RTHDRDSTOPTS:
745 if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
750 hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
751 len = ((hdr->hdrlen + 1) << 3);
752 if (cmsg->cmsg_len < CMSG_LEN(len)) {
756 if (!capable(CAP_NET_RAW)) {
760 if (cmsg->cmsg_type == IPV6_DSTOPTS) {
761 opt->opt_flen += len;
764 opt->opt_nflen += len;
771 if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
776 rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
778 switch (rthdr->type) {
779 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
780 case IPV6_SRCRT_TYPE_2:
781 if (rthdr->hdrlen != 2 ||
782 rthdr->segments_left != 1) {
793 len = ((rthdr->hdrlen + 1) << 3);
795 if (cmsg->cmsg_len < CMSG_LEN(len)) {
800 /* segments left must also match */
801 if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
806 opt->opt_nflen += len;
809 if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
810 int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
812 opt->opt_nflen += dsthdrlen;
813 opt->dst0opt = opt->dst1opt;
815 opt->opt_flen -= dsthdrlen;
820 case IPV6_2292HOPLIMIT:
822 if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
827 *hlimit = *(int *)CMSG_DATA(cmsg);
828 if (*hlimit < -1 || *hlimit > 0xff) {
840 if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
844 tc = *(int *)CMSG_DATA(cmsg);
845 if (tc < -1 || tc > 0xff)
859 if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
863 df = *(int *)CMSG_DATA(cmsg);
864 if (df < 0 || df > 1)
873 LIMIT_NETDEBUG(KERN_DEBUG "invalid cmsg type: %d\n",