2 * L2TPv3 IP encapsulation support for IPv6
4 * Copyright (c) 2012 Katalix Systems Ltd
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14 #include <linux/icmp.h>
15 #include <linux/module.h>
16 #include <linux/skbuff.h>
17 #include <linux/random.h>
18 #include <linux/socket.h>
19 #include <linux/l2tp.h>
21 #include <linux/in6.h>
26 #include <net/inet_common.h>
27 #include <net/tcp_states.h>
28 #include <net/protocol.h>
31 #include <net/transp_v6.h>
32 #include <net/addrconf.h>
33 #include <net/ip6_route.h>
35 #include "l2tp_core.h"
37 struct l2tp_ip6_sock {
38 /* inet_sock has to be the first member of l2tp_ip6_sock */
39 struct inet_sock inet;
44 /* ipv6_pinfo has to be the last member of l2tp_ip6_sock, see
46 struct ipv6_pinfo inet6;
49 static DEFINE_RWLOCK(l2tp_ip6_lock);
50 static struct hlist_head l2tp_ip6_table;
51 static struct hlist_head l2tp_ip6_bind_table;
53 static inline struct l2tp_ip6_sock *l2tp_ip6_sk(const struct sock *sk)
55 return (struct l2tp_ip6_sock *)sk;
58 static struct sock *__l2tp_ip6_bind_lookup(const struct net *net,
59 const struct in6_addr *laddr,
60 const struct in6_addr *raddr,
61 int dif, u32 tunnel_id)
65 sk_for_each_bound(sk, &l2tp_ip6_bind_table) {
66 const struct in6_addr *sk_laddr = inet6_rcv_saddr(sk);
67 const struct in6_addr *sk_raddr = &sk->sk_v6_daddr;
68 const struct l2tp_ip6_sock *l2tp = l2tp_ip6_sk(sk);
70 if (!net_eq(sock_net(sk), net))
73 if (sk->sk_bound_dev_if && dif && sk->sk_bound_dev_if != dif)
76 if (sk_laddr && !ipv6_addr_any(sk_laddr) &&
77 !ipv6_addr_any(laddr) && !ipv6_addr_equal(sk_laddr, laddr))
80 if (!ipv6_addr_any(sk_raddr) && raddr &&
81 !ipv6_addr_any(raddr) && !ipv6_addr_equal(sk_raddr, raddr))
84 if (l2tp->conn_id != tunnel_id)
95 /* When processing receive frames, there are two cases to
96 * consider. Data frames consist of a non-zero session-id and an
97 * optional cookie. Control frames consist of a regular L2TP header
98 * preceded by 32-bits of zeros.
100 * L2TPv3 Session Header Over IP
103 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
104 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
106 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
107 * | Cookie (optional, maximum 64 bits)...
108 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
110 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
112 * L2TPv3 Control Message Header Over IP
115 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
116 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
117 * | (32 bits of zeros) |
118 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
119 * |T|L|x|x|S|x|x|x|x|x|x|x| Ver | Length |
120 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
121 * | Control Connection ID |
122 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
124 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
126 * All control frames are passed to userspace.
128 static int l2tp_ip6_recv(struct sk_buff *skb)
130 struct net *net = dev_net(skb->dev);
134 unsigned char *ptr, *optr;
135 struct l2tp_session *session;
136 struct l2tp_tunnel *tunnel = NULL;
140 if (!pskb_may_pull(skb, 4))
143 /* Point to L2TP header */
144 optr = ptr = skb->data;
145 session_id = ntohl(*((__be32 *) ptr));
148 /* RFC3931: L2TP/IP packets have the first 4 bytes containing
149 * the session_id. If it is 0, the packet is a L2TP control
150 * frame and the session_id value can be discarded.
152 if (session_id == 0) {
157 /* Ok, this is a data packet. Lookup the session. */
158 session = l2tp_session_get(net, NULL, session_id, true);
162 tunnel = session->tunnel;
166 /* Trace packet contents, if enabled */
167 if (tunnel->debug & L2TP_MSG_DATA) {
168 length = min(32u, skb->len);
169 if (!pskb_may_pull(skb, length))
172 /* Point to L2TP header */
173 optr = ptr = skb->data;
175 pr_debug("%s: ip recv\n", tunnel->name);
176 print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, ptr, length);
179 if (l2tp_v3_ensure_opt_in_linear(session, skb, &ptr, &optr))
182 l2tp_recv_common(session, skb, ptr, optr, 0, skb->len,
183 tunnel->recv_payload_hook);
184 l2tp_session_dec_refcount(session);
189 /* Get the tunnel_id from the L2TP header */
190 if (!pskb_may_pull(skb, 12))
193 if ((skb->data[0] & 0xc0) != 0xc0)
196 tunnel_id = ntohl(*(__be32 *) &skb->data[4]);
199 read_lock_bh(&l2tp_ip6_lock);
200 sk = __l2tp_ip6_bind_lookup(net, &iph->daddr, &iph->saddr,
201 inet6_iif(skb), tunnel_id);
203 read_unlock_bh(&l2tp_ip6_lock);
207 read_unlock_bh(&l2tp_ip6_lock);
209 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
214 return sk_receive_skb(sk, skb, 1);
218 session->deref(session);
219 l2tp_session_dec_refcount(session);
230 static int l2tp_ip6_hash(struct sock *sk)
232 if (sk_unhashed(sk)) {
233 write_lock_bh(&l2tp_ip6_lock);
234 sk_add_node(sk, &l2tp_ip6_table);
235 write_unlock_bh(&l2tp_ip6_lock);
240 static void l2tp_ip6_unhash(struct sock *sk)
244 write_lock_bh(&l2tp_ip6_lock);
245 sk_del_node_init(sk);
246 write_unlock_bh(&l2tp_ip6_lock);
249 static int l2tp_ip6_open(struct sock *sk)
251 /* Prevent autobind. We don't have ports. */
252 inet_sk(sk)->inet_num = IPPROTO_L2TP;
258 static void l2tp_ip6_close(struct sock *sk, long timeout)
260 write_lock_bh(&l2tp_ip6_lock);
261 hlist_del_init(&sk->sk_bind_node);
262 sk_del_node_init(sk);
263 write_unlock_bh(&l2tp_ip6_lock);
265 sk_common_release(sk);
268 static void l2tp_ip6_destroy_sock(struct sock *sk)
270 struct l2tp_tunnel *tunnel = l2tp_sock_to_tunnel(sk);
273 ip6_flush_pending_frames(sk);
277 l2tp_tunnel_closeall(tunnel);
282 static int l2tp_ip6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
284 struct inet_sock *inet = inet_sk(sk);
285 struct ipv6_pinfo *np = inet6_sk(sk);
286 struct sockaddr_l2tpip6 *addr = (struct sockaddr_l2tpip6 *) uaddr;
287 struct net *net = sock_net(sk);
293 if (addr->l2tp_family != AF_INET6)
295 if (addr_len < sizeof(*addr))
298 addr_type = ipv6_addr_type(&addr->l2tp_addr);
300 /* l2tp_ip6 sockets are IPv6 only */
301 if (addr_type == IPV6_ADDR_MAPPED)
302 return -EADDRNOTAVAIL;
304 /* L2TP is point-point, not multicast */
305 if (addr_type & IPV6_ADDR_MULTICAST)
306 return -EADDRNOTAVAIL;
311 if (!sock_flag(sk, SOCK_ZAPPED))
314 if (sk->sk_state != TCP_CLOSE)
317 bound_dev_if = sk->sk_bound_dev_if;
319 /* Check if the address belongs to the host. */
321 if (addr_type != IPV6_ADDR_ANY) {
322 struct net_device *dev = NULL;
324 if (addr_type & IPV6_ADDR_LINKLOCAL) {
325 if (addr->l2tp_scope_id)
326 bound_dev_if = addr->l2tp_scope_id;
328 /* Binding to link-local address requires an
335 dev = dev_get_by_index_rcu(sock_net(sk), bound_dev_if);
340 /* ipv4 addr of the socket is invalid. Only the
341 * unspecified and mapped address have a v4 equivalent.
343 v4addr = LOOPBACK4_IPV6;
344 err = -EADDRNOTAVAIL;
345 if (!ipv6_chk_addr(sock_net(sk), &addr->l2tp_addr, dev, 0))
350 write_lock_bh(&l2tp_ip6_lock);
351 if (__l2tp_ip6_bind_lookup(net, &addr->l2tp_addr, NULL, bound_dev_if,
352 addr->l2tp_conn_id)) {
353 write_unlock_bh(&l2tp_ip6_lock);
358 inet->inet_saddr = v4addr;
359 inet->inet_rcv_saddr = v4addr;
360 sk->sk_bound_dev_if = bound_dev_if;
361 sk->sk_v6_rcv_saddr = addr->l2tp_addr;
362 np->saddr = addr->l2tp_addr;
364 l2tp_ip6_sk(sk)->conn_id = addr->l2tp_conn_id;
366 sk_add_bind_node(sk, &l2tp_ip6_bind_table);
367 sk_del_node_init(sk);
368 write_unlock_bh(&l2tp_ip6_lock);
370 sock_reset_flag(sk, SOCK_ZAPPED);
382 static int l2tp_ip6_connect(struct sock *sk, struct sockaddr *uaddr,
385 struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *) uaddr;
386 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
387 struct in6_addr *daddr;
391 if (addr_len < sizeof(*lsa))
394 if (usin->sin6_family != AF_INET6)
397 addr_type = ipv6_addr_type(&usin->sin6_addr);
398 if (addr_type & IPV6_ADDR_MULTICAST)
401 if (addr_type & IPV6_ADDR_MAPPED) {
402 daddr = &usin->sin6_addr;
403 if (ipv4_is_multicast(daddr->s6_addr32[3]))
409 /* Must bind first - autobinding does not work */
410 if (sock_flag(sk, SOCK_ZAPPED)) {
415 rc = __ip6_datagram_connect(sk, uaddr, addr_len);
419 l2tp_ip6_sk(sk)->peer_conn_id = lsa->l2tp_conn_id;
421 write_lock_bh(&l2tp_ip6_lock);
422 hlist_del_init(&sk->sk_bind_node);
423 sk_add_bind_node(sk, &l2tp_ip6_bind_table);
424 write_unlock_bh(&l2tp_ip6_lock);
432 static int l2tp_ip6_disconnect(struct sock *sk, int flags)
434 if (sock_flag(sk, SOCK_ZAPPED))
437 return __udp_disconnect(sk, flags);
440 static int l2tp_ip6_getname(struct socket *sock, struct sockaddr *uaddr,
441 int *uaddr_len, int peer)
443 struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *)uaddr;
444 struct sock *sk = sock->sk;
445 struct ipv6_pinfo *np = inet6_sk(sk);
446 struct l2tp_ip6_sock *lsk = l2tp_ip6_sk(sk);
448 lsa->l2tp_family = AF_INET6;
449 lsa->l2tp_flowinfo = 0;
450 lsa->l2tp_scope_id = 0;
451 lsa->l2tp_unused = 0;
453 if (!lsk->peer_conn_id)
455 lsa->l2tp_conn_id = lsk->peer_conn_id;
456 lsa->l2tp_addr = sk->sk_v6_daddr;
458 lsa->l2tp_flowinfo = np->flow_label;
460 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr))
461 lsa->l2tp_addr = np->saddr;
463 lsa->l2tp_addr = sk->sk_v6_rcv_saddr;
465 lsa->l2tp_conn_id = lsk->conn_id;
467 if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL)
468 lsa->l2tp_scope_id = sk->sk_bound_dev_if;
469 *uaddr_len = sizeof(*lsa);
473 static int l2tp_ip6_backlog_recv(struct sock *sk, struct sk_buff *skb)
477 /* Charge it to the socket, dropping if the queue is full. */
478 rc = sock_queue_rcv_skb(sk, skb);
485 IP_INC_STATS(sock_net(sk), IPSTATS_MIB_INDISCARDS);
490 static int l2tp_ip6_push_pending_frames(struct sock *sk)
493 __be32 *transhdr = NULL;
496 skb = skb_peek(&sk->sk_write_queue);
500 transhdr = (__be32 *)skb_transport_header(skb);
503 err = ip6_push_pending_frames(sk);
509 /* Userspace will call sendmsg() on the tunnel socket to send L2TP
512 static int l2tp_ip6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
514 struct ipv6_txoptions opt_space;
515 DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name);
516 struct in6_addr *daddr, *final_p, final;
517 struct ipv6_pinfo *np = inet6_sk(sk);
518 struct ipv6_txoptions *opt_to_free = NULL;
519 struct ipv6_txoptions *opt = NULL;
520 struct ip6_flowlabel *flowlabel = NULL;
521 struct dst_entry *dst = NULL;
523 struct sockcm_cookie sockc_unused = {0};
524 struct ipcm6_cookie ipc6;
525 int addr_len = msg->msg_namelen;
526 int transhdrlen = 4; /* zero session-id */
530 /* Rough check on arithmetic overflow,
531 better check is made in ip6_append_data().
533 if (len > INT_MAX - transhdrlen)
536 /* Mirror BSD error message compatibility */
537 if (msg->msg_flags & MSG_OOB)
541 * Get and verify the address.
543 memset(&fl6, 0, sizeof(fl6));
545 fl6.flowi6_mark = sk->sk_mark;
546 fl6.flowi6_uid = sk->sk_uid;
553 if (addr_len < SIN6_LEN_RFC2133)
556 if (lsa->l2tp_family && lsa->l2tp_family != AF_INET6)
557 return -EAFNOSUPPORT;
559 daddr = &lsa->l2tp_addr;
561 fl6.flowlabel = lsa->l2tp_flowinfo & IPV6_FLOWINFO_MASK;
562 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
563 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
564 if (flowlabel == NULL)
570 * Otherwise it will be difficult to maintain
573 if (sk->sk_state == TCP_ESTABLISHED &&
574 ipv6_addr_equal(daddr, &sk->sk_v6_daddr))
575 daddr = &sk->sk_v6_daddr;
577 if (addr_len >= sizeof(struct sockaddr_in6) &&
578 lsa->l2tp_scope_id &&
579 ipv6_addr_type(daddr) & IPV6_ADDR_LINKLOCAL)
580 fl6.flowi6_oif = lsa->l2tp_scope_id;
582 if (sk->sk_state != TCP_ESTABLISHED)
583 return -EDESTADDRREQ;
585 daddr = &sk->sk_v6_daddr;
586 fl6.flowlabel = np->flow_label;
589 if (fl6.flowi6_oif == 0)
590 fl6.flowi6_oif = sk->sk_bound_dev_if;
592 if (msg->msg_controllen) {
594 memset(opt, 0, sizeof(struct ipv6_txoptions));
595 opt->tot_len = sizeof(struct ipv6_txoptions);
598 err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6,
601 fl6_sock_release(flowlabel);
604 if ((fl6.flowlabel & IPV6_FLOWLABEL_MASK) && !flowlabel) {
605 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
606 if (flowlabel == NULL)
609 if (!(opt->opt_nflen|opt->opt_flen))
618 opt = fl6_merge_options(&opt_space, flowlabel, opt);
619 opt = ipv6_fixup_options(&opt_space, opt);
622 fl6.flowi6_proto = sk->sk_protocol;
623 if (!ipv6_addr_any(daddr))
626 fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */
627 if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr))
628 fl6.saddr = np->saddr;
630 final_p = fl6_update_dst(&fl6, opt, &final);
632 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
633 fl6.flowi6_oif = np->mcast_oif;
634 else if (!fl6.flowi6_oif)
635 fl6.flowi6_oif = np->ucast_oif;
637 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
640 ipc6.tclass = np->tclass;
642 fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
644 dst = ip6_dst_lookup_flow(sock_net(sk), sk, &fl6, final_p);
651 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
653 if (ipc6.dontfrag < 0)
654 ipc6.dontfrag = np->dontfrag;
656 if (msg->msg_flags & MSG_CONFIRM)
661 ulen = len + skb_queue_empty(&sk->sk_write_queue) ? transhdrlen : 0;
662 err = ip6_append_data(sk, ip_generic_getfrag, msg,
663 ulen, transhdrlen, &ipc6,
664 &fl6, (struct rt6_info *)dst,
665 msg->msg_flags, &sockc_unused);
667 ip6_flush_pending_frames(sk);
668 else if (!(msg->msg_flags & MSG_MORE))
669 err = l2tp_ip6_push_pending_frames(sk);
674 fl6_sock_release(flowlabel);
675 txopt_put(opt_to_free);
677 return err < 0 ? err : len;
680 if (msg->msg_flags & MSG_PROBE)
681 dst_confirm_neigh(dst, &fl6.daddr);
682 if (!(msg->msg_flags & MSG_PROBE) || len)
683 goto back_from_confirm;
688 static int l2tp_ip6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
689 int noblock, int flags, int *addr_len)
691 struct ipv6_pinfo *np = inet6_sk(sk);
692 DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name);
694 int err = -EOPNOTSUPP;
700 if (flags & MSG_ERRQUEUE)
701 return ipv6_recv_error(sk, msg, len, addr_len);
703 skb = skb_recv_datagram(sk, flags, noblock, &err);
709 msg->msg_flags |= MSG_TRUNC;
713 err = skb_copy_datagram_msg(skb, 0, msg, copied);
717 sock_recv_timestamp(msg, sk, skb);
719 /* Copy the address. */
721 lsa->l2tp_family = AF_INET6;
722 lsa->l2tp_unused = 0;
723 lsa->l2tp_addr = ipv6_hdr(skb)->saddr;
724 lsa->l2tp_flowinfo = 0;
725 lsa->l2tp_scope_id = 0;
726 lsa->l2tp_conn_id = 0;
727 if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL)
728 lsa->l2tp_scope_id = inet6_iif(skb);
729 *addr_len = sizeof(*lsa);
733 ip6_datagram_recv_ctl(sk, msg, skb);
735 if (flags & MSG_TRUNC)
738 skb_free_datagram(sk, skb);
740 return err ? err : copied;
743 static struct proto l2tp_ip6_prot = {
745 .owner = THIS_MODULE,
746 .init = l2tp_ip6_open,
747 .close = l2tp_ip6_close,
748 .bind = l2tp_ip6_bind,
749 .connect = l2tp_ip6_connect,
750 .disconnect = l2tp_ip6_disconnect,
752 .destroy = l2tp_ip6_destroy_sock,
753 .setsockopt = ipv6_setsockopt,
754 .getsockopt = ipv6_getsockopt,
755 .sendmsg = l2tp_ip6_sendmsg,
756 .recvmsg = l2tp_ip6_recvmsg,
757 .backlog_rcv = l2tp_ip6_backlog_recv,
758 .hash = l2tp_ip6_hash,
759 .unhash = l2tp_ip6_unhash,
760 .obj_size = sizeof(struct l2tp_ip6_sock),
762 .compat_setsockopt = compat_ipv6_setsockopt,
763 .compat_getsockopt = compat_ipv6_getsockopt,
767 static const struct proto_ops l2tp_ip6_ops = {
769 .owner = THIS_MODULE,
770 .release = inet6_release,
772 .connect = inet_dgram_connect,
773 .socketpair = sock_no_socketpair,
774 .accept = sock_no_accept,
775 .getname = l2tp_ip6_getname,
776 .poll = datagram_poll,
777 .ioctl = inet6_ioctl,
778 .listen = sock_no_listen,
779 .shutdown = inet_shutdown,
780 .setsockopt = sock_common_setsockopt,
781 .getsockopt = sock_common_getsockopt,
782 .sendmsg = inet_sendmsg,
783 .recvmsg = sock_common_recvmsg,
784 .mmap = sock_no_mmap,
785 .sendpage = sock_no_sendpage,
787 .compat_setsockopt = compat_sock_common_setsockopt,
788 .compat_getsockopt = compat_sock_common_getsockopt,
792 static struct inet_protosw l2tp_ip6_protosw = {
794 .protocol = IPPROTO_L2TP,
795 .prot = &l2tp_ip6_prot,
796 .ops = &l2tp_ip6_ops,
799 static struct inet6_protocol l2tp_ip6_protocol __read_mostly = {
800 .handler = l2tp_ip6_recv,
803 static int __init l2tp_ip6_init(void)
807 pr_info("L2TP IP encapsulation support for IPv6 (L2TPv3)\n");
809 err = proto_register(&l2tp_ip6_prot, 1);
813 err = inet6_add_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP);
817 inet6_register_protosw(&l2tp_ip6_protosw);
821 proto_unregister(&l2tp_ip6_prot);
826 static void __exit l2tp_ip6_exit(void)
828 inet6_unregister_protosw(&l2tp_ip6_protosw);
829 inet6_del_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP);
830 proto_unregister(&l2tp_ip6_prot);
833 module_init(l2tp_ip6_init);
834 module_exit(l2tp_ip6_exit);
836 MODULE_LICENSE("GPL");
837 MODULE_AUTHOR("Chris Elston <celston@katalix.com>");
838 MODULE_DESCRIPTION("L2TP IP encapsulation for IPv6");
839 MODULE_VERSION("1.0");
841 /* Use the value of SOCK_DGRAM (2) directory, because __stringify doesn't like
844 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 2, IPPROTO_L2TP);
845 MODULE_ALIAS_NET_PF_PROTO(PF_INET6, IPPROTO_L2TP);