1 /*****************************************************************************
2 * Linux PPP over L2TP (PPPoX/PPPoL2TP) Sockets
4 * PPPoX --- Generic PPP encapsulation socket family
5 * PPPoL2TP --- PPP over L2TP (RFC 2661)
9 * Authors: Martijn van Oosterhout <kleptog@svana.org>
10 * James Chapman (jchapman@katalix.com)
12 * Michal Ostrowski <mostrows@speakeasy.net>
13 * Arnaldo Carvalho de Melo <acme@xconectiva.com.br>
14 * David S. Miller (davem@redhat.com)
17 * This program is free software; you can redistribute it and/or
18 * modify it under the terms of the GNU General Public License
19 * as published by the Free Software Foundation; either version
20 * 2 of the License, or (at your option) any later version.
24 /* This driver handles only L2TP data frames; control frames are handled by a
25 * userspace application.
27 * To send data in an L2TP session, userspace opens a PPPoL2TP socket and
28 * attaches it to a bound UDP socket with local tunnel_id / session_id and
29 * peer tunnel_id / session_id set. Data can then be sent or received using
30 * regular socket sendmsg() / recvmsg() calls. Kernel parameters of the socket
31 * can be read or modified using ioctl() or [gs]etsockopt() calls.
33 * When a PPPoL2TP socket is connected with local and peer session_id values
34 * zero, the socket is treated as a special tunnel management socket.
36 * Here's example userspace code to create a socket for sending/receiving data
37 * over an L2TP session:-
39 * struct sockaddr_pppol2tp sax;
43 * fd = socket(AF_PPPOX, SOCK_DGRAM, PX_PROTO_OL2TP);
45 * sax.sa_family = AF_PPPOX;
46 * sax.sa_protocol = PX_PROTO_OL2TP;
47 * sax.pppol2tp.fd = tunnel_fd; // bound UDP socket
48 * sax.pppol2tp.addr.sin_addr.s_addr = addr->sin_addr.s_addr;
49 * sax.pppol2tp.addr.sin_port = addr->sin_port;
50 * sax.pppol2tp.addr.sin_family = AF_INET;
51 * sax.pppol2tp.s_tunnel = tunnel_id;
52 * sax.pppol2tp.s_session = session_id;
53 * sax.pppol2tp.d_tunnel = peer_tunnel_id;
54 * sax.pppol2tp.d_session = peer_session_id;
56 * session_fd = connect(fd, (struct sockaddr *)&sax, sizeof(sax));
58 * A pppd plugin that allows PPP traffic to be carried over L2TP using
59 * this driver is available from the OpenL2TP project at
60 * http://openl2tp.sourceforge.net.
63 #include <linux/module.h>
64 #include <linux/version.h>
65 #include <linux/string.h>
66 #include <linux/list.h>
67 #include <asm/uaccess.h>
69 #include <linux/kernel.h>
70 #include <linux/spinlock.h>
71 #include <linux/kthread.h>
72 #include <linux/sched.h>
73 #include <linux/slab.h>
74 #include <linux/errno.h>
75 #include <linux/jiffies.h>
77 #include <linux/netdevice.h>
78 #include <linux/net.h>
79 #include <linux/inetdevice.h>
80 #include <linux/skbuff.h>
81 #include <linux/init.h>
83 #include <linux/udp.h>
84 #include <linux/if_pppox.h>
85 #include <linux/if_pppol2tp.h>
87 #include <linux/ppp_channel.h>
88 #include <linux/ppp_defs.h>
89 #include <linux/if_ppp.h>
90 #include <linux/file.h>
91 #include <linux/hash.h>
92 #include <linux/sort.h>
93 #include <linux/proc_fs.h>
94 #include <net/net_namespace.h>
100 #include <asm/byteorder.h>
101 #include <asm/atomic.h>
104 #define PPPOL2TP_DRV_VERSION "V1.0"
106 /* L2TP header constants */
107 #define L2TP_HDRFLAG_T 0x8000
108 #define L2TP_HDRFLAG_L 0x4000
109 #define L2TP_HDRFLAG_S 0x0800
110 #define L2TP_HDRFLAG_O 0x0200
111 #define L2TP_HDRFLAG_P 0x0100
113 #define L2TP_HDR_VER_MASK 0x000F
114 #define L2TP_HDR_VER 0x0002
116 /* Space for UDP, L2TP and PPP headers */
117 #define PPPOL2TP_HEADER_OVERHEAD 40
119 /* Just some random numbers */
120 #define L2TP_TUNNEL_MAGIC 0x42114DDA
121 #define L2TP_SESSION_MAGIC 0x0C04EB7D
123 #define PPPOL2TP_HASH_BITS 4
124 #define PPPOL2TP_HASH_SIZE (1 << PPPOL2TP_HASH_BITS)
126 /* Default trace flags */
127 #define PPPOL2TP_DEFAULT_DEBUG_FLAGS 0
129 #define PRINTK(_mask, _type, _lvl, _fmt, args...) \
131 if ((_mask) & (_type)) \
132 printk(_lvl "PPPOL2TP: " _fmt, ##args); \
135 /* Number of bytes to build transmit L2TP headers.
136 * Unfortunately the size is different depending on whether sequence numbers
139 #define PPPOL2TP_L2TP_HDR_SIZE_SEQ 10
140 #define PPPOL2TP_L2TP_HDR_SIZE_NOSEQ 6
142 struct pppol2tp_tunnel;
144 /* Describes a session. It is the sk_user_data field in the PPPoL2TP
145 * socket. Contains information to determine incoming packets and transmit
148 struct pppol2tp_session
150 int magic; /* should be
151 * L2TP_SESSION_MAGIC */
152 int owner; /* pid that opened the socket */
154 struct sock *sock; /* Pointer to the session
156 struct sock *tunnel_sock; /* Pointer to the tunnel UDP
159 struct pppol2tp_addr tunnel_addr; /* Description of tunnel */
161 struct pppol2tp_tunnel *tunnel; /* back pointer to tunnel
164 char name[20]; /* "sess xxxxx/yyyyy", where
165 * x=tunnel_id, y=session_id */
168 int flags; /* accessed by PPPIOCGFLAGS.
170 unsigned recv_seq:1; /* expect receive packets with
171 * sequence numbers? */
172 unsigned send_seq:1; /* send packets with sequence
174 unsigned lns_mode:1; /* behave as LNS? LAC enables
175 * sequence numbers under
177 int debug; /* bitmask of debug message
179 int reorder_timeout; /* configured reorder timeout
181 u16 nr; /* session NR state (receive) */
182 u16 ns; /* session NR state (send) */
183 struct sk_buff_head reorder_q; /* receive reorder queue */
184 struct pppol2tp_ioc_stats stats;
185 struct hlist_node hlist; /* Hash list node */
188 /* The sk_user_data field of the tunnel's UDP socket. It contains info to track
189 * all the associated sessions so incoming packets can be sorted out
191 struct pppol2tp_tunnel
193 int magic; /* Should be L2TP_TUNNEL_MAGIC */
194 rwlock_t hlist_lock; /* protect session_hlist */
195 struct hlist_head session_hlist[PPPOL2TP_HASH_SIZE];
196 /* hashed list of sessions,
198 int debug; /* bitmask of debug message
200 char name[12]; /* "tunl xxxxx" */
201 struct pppol2tp_ioc_stats stats;
203 void (*old_sk_destruct)(struct sock *);
205 struct sock *sock; /* Parent socket */
206 struct list_head list; /* Keep a list of all open
207 * prepared sockets */
212 /* Private data stored for received packets in the skb.
214 struct pppol2tp_skb_cb {
219 unsigned long expires;
222 #define PPPOL2TP_SKB_CB(skb) ((struct pppol2tp_skb_cb *) &skb->cb[sizeof(struct inet_skb_parm)])
224 static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb);
225 static void pppol2tp_tunnel_free(struct pppol2tp_tunnel *tunnel);
227 static atomic_t pppol2tp_tunnel_count;
228 static atomic_t pppol2tp_session_count;
229 static struct ppp_channel_ops pppol2tp_chan_ops = { pppol2tp_xmit , NULL };
230 static struct proto_ops pppol2tp_ops;
231 static LIST_HEAD(pppol2tp_tunnel_list);
232 static DEFINE_RWLOCK(pppol2tp_tunnel_list_lock);
234 /* Helpers to obtain tunnel/session contexts from sockets.
236 static inline struct pppol2tp_session *pppol2tp_sock_to_session(struct sock *sk)
238 struct pppol2tp_session *session;
243 session = (struct pppol2tp_session *)(sk->sk_user_data);
247 BUG_ON(session->magic != L2TP_SESSION_MAGIC);
252 static inline struct pppol2tp_tunnel *pppol2tp_sock_to_tunnel(struct sock *sk)
254 struct pppol2tp_tunnel *tunnel;
259 tunnel = (struct pppol2tp_tunnel *)(sk->sk_user_data);
263 BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);
268 /* Tunnel reference counts. Incremented per session that is added to
271 static inline void pppol2tp_tunnel_inc_refcount(struct pppol2tp_tunnel *tunnel)
273 atomic_inc(&tunnel->ref_count);
276 static inline void pppol2tp_tunnel_dec_refcount(struct pppol2tp_tunnel *tunnel)
278 if (atomic_dec_and_test(&tunnel->ref_count))
279 pppol2tp_tunnel_free(tunnel);
282 /* Session hash list.
283 * The session_id SHOULD be random according to RFC2661, but several
284 * L2TP implementations (Cisco and Microsoft) use incrementing
285 * session_ids. So we do a real hash on the session_id, rather than a
288 static inline struct hlist_head *
289 pppol2tp_session_id_hash(struct pppol2tp_tunnel *tunnel, u16 session_id)
291 unsigned long hash_val = (unsigned long) session_id;
292 return &tunnel->session_hlist[hash_long(hash_val, PPPOL2TP_HASH_BITS)];
295 /* Lookup a session by id
297 static struct pppol2tp_session *
298 pppol2tp_session_find(struct pppol2tp_tunnel *tunnel, u16 session_id)
300 struct hlist_head *session_list =
301 pppol2tp_session_id_hash(tunnel, session_id);
302 struct pppol2tp_session *session;
303 struct hlist_node *walk;
305 read_lock_bh(&tunnel->hlist_lock);
306 hlist_for_each_entry(session, walk, session_list, hlist) {
307 if (session->tunnel_addr.s_session == session_id) {
308 read_unlock_bh(&tunnel->hlist_lock);
312 read_unlock_bh(&tunnel->hlist_lock);
317 /* Lookup a tunnel by id
319 static struct pppol2tp_tunnel *pppol2tp_tunnel_find(u16 tunnel_id)
321 struct pppol2tp_tunnel *tunnel = NULL;
323 read_lock_bh(&pppol2tp_tunnel_list_lock);
324 list_for_each_entry(tunnel, &pppol2tp_tunnel_list, list) {
325 if (tunnel->stats.tunnel_id == tunnel_id) {
326 read_unlock_bh(&pppol2tp_tunnel_list_lock);
330 read_unlock_bh(&pppol2tp_tunnel_list_lock);
335 /*****************************************************************************
336 * Receive data handling
337 *****************************************************************************/
339 /* Queue a skb in order. We come here only if the skb has an L2TP sequence
342 static void pppol2tp_recv_queue_skb(struct pppol2tp_session *session, struct sk_buff *skb)
344 struct sk_buff *skbp;
346 u16 ns = PPPOL2TP_SKB_CB(skb)->ns;
348 spin_lock_bh(&session->reorder_q.lock);
349 skb_queue_walk_safe(&session->reorder_q, skbp, tmp) {
350 if (PPPOL2TP_SKB_CB(skbp)->ns > ns) {
351 __skb_insert(skb, skbp->prev, skbp, &session->reorder_q);
352 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
353 "%s: pkt %hu, inserted before %hu, reorder_q len=%d\n",
354 session->name, ns, PPPOL2TP_SKB_CB(skbp)->ns,
355 skb_queue_len(&session->reorder_q));
356 session->stats.rx_oos_packets++;
361 __skb_queue_tail(&session->reorder_q, skb);
364 spin_unlock_bh(&session->reorder_q.lock);
367 /* Dequeue a single skb.
369 static void pppol2tp_recv_dequeue_skb(struct pppol2tp_session *session, struct sk_buff *skb)
371 struct pppol2tp_tunnel *tunnel = session->tunnel;
372 int length = PPPOL2TP_SKB_CB(skb)->length;
373 struct sock *session_sock = NULL;
375 /* We're about to requeue the skb, so return resources
376 * to its current owner (a socket receive buffer).
380 tunnel->stats.rx_packets++;
381 tunnel->stats.rx_bytes += length;
382 session->stats.rx_packets++;
383 session->stats.rx_bytes += length;
385 if (PPPOL2TP_SKB_CB(skb)->has_seq) {
388 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
389 "%s: updated nr to %hu\n", session->name, session->nr);
392 /* If the socket is bound, send it in to PPP's input queue. Otherwise
393 * queue it on the session socket.
395 session_sock = session->sock;
396 if (session_sock->sk_state & PPPOX_BOUND) {
397 struct pppox_sock *po;
398 PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
399 "%s: recv %d byte data frame, passing to ppp\n",
400 session->name, length);
402 /* We need to forget all info related to the L2TP packet
403 * gathered in the skb as we are going to reuse the same
404 * skb for the inner packet.
406 * - reset xfrm (IPSec) information as it applies to
407 * the outer L2TP packet and not to the inner one
408 * - release the dst to force a route lookup on the inner
409 * IP packet since skb->dst currently points to the dst
411 * - reset netfilter information as it doesn't apply
412 * to the inner packet either
415 dst_release(skb->dst);
419 po = pppox_sk(session_sock);
420 ppp_input(&po->chan, skb);
422 PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_INFO,
423 "%s: socket not bound\n", session->name);
425 /* Not bound. Nothing we can do, so discard. */
426 session->stats.rx_errors++;
430 sock_put(session->sock);
433 /* Dequeue skbs from the session's reorder_q, subject to packet order.
434 * Skbs that have been in the queue for too long are simply discarded.
436 static void pppol2tp_recv_dequeue(struct pppol2tp_session *session)
441 /* If the pkt at the head of the queue has the nr that we
442 * expect to send up next, dequeue it and any other
443 * in-sequence packets behind it.
445 spin_lock_bh(&session->reorder_q.lock);
446 skb_queue_walk_safe(&session->reorder_q, skb, tmp) {
447 if (time_after(jiffies, PPPOL2TP_SKB_CB(skb)->expires)) {
448 session->stats.rx_seq_discards++;
449 session->stats.rx_errors++;
450 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
451 "%s: oos pkt %hu len %d discarded (too old), "
452 "waiting for %hu, reorder_q_len=%d\n",
453 session->name, PPPOL2TP_SKB_CB(skb)->ns,
454 PPPOL2TP_SKB_CB(skb)->length, session->nr,
455 skb_queue_len(&session->reorder_q));
456 __skb_unlink(skb, &session->reorder_q);
458 sock_put(session->sock);
462 if (PPPOL2TP_SKB_CB(skb)->has_seq) {
463 if (PPPOL2TP_SKB_CB(skb)->ns != session->nr) {
464 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
465 "%s: holding oos pkt %hu len %d, "
466 "waiting for %hu, reorder_q_len=%d\n",
467 session->name, PPPOL2TP_SKB_CB(skb)->ns,
468 PPPOL2TP_SKB_CB(skb)->length, session->nr,
469 skb_queue_len(&session->reorder_q));
473 __skb_unlink(skb, &session->reorder_q);
475 /* Process the skb. We release the queue lock while we
476 * do so to let other contexts process the queue.
478 spin_unlock_bh(&session->reorder_q.lock);
479 pppol2tp_recv_dequeue_skb(session, skb);
480 spin_lock_bh(&session->reorder_q.lock);
484 spin_unlock_bh(&session->reorder_q.lock);
487 /* Internal receive frame. Do the real work of receiving an L2TP data frame
488 * here. The skb is not on a list when we get here.
489 * Returns 0 if the packet was a data packet and was successfully passed on.
490 * Returns 1 if the packet was not a good data packet and could not be
491 * forwarded. All such packets are passed up to userspace to deal with.
493 static int pppol2tp_recv_core(struct sock *sock, struct sk_buff *skb)
495 struct pppol2tp_session *session = NULL;
496 struct pppol2tp_tunnel *tunnel;
497 unsigned char *ptr, *optr;
499 u16 tunnel_id, session_id;
503 tunnel = pppol2tp_sock_to_tunnel(sock);
507 /* UDP always verifies the packet length. */
508 __skb_pull(skb, sizeof(struct udphdr));
511 if (!pskb_may_pull(skb, 12)) {
512 PRINTK(tunnel->debug, PPPOL2TP_MSG_DATA, KERN_INFO,
513 "%s: recv short packet (len=%d)\n", tunnel->name, skb->len);
517 /* Point to L2TP header */
518 optr = ptr = skb->data;
520 /* Get L2TP header flags */
521 hdrflags = ntohs(*(__be16*)ptr);
523 /* Trace packet contents, if enabled */
524 if (tunnel->debug & PPPOL2TP_MSG_DATA) {
525 length = min(16u, skb->len);
526 if (!pskb_may_pull(skb, length))
529 printk(KERN_DEBUG "%s: recv: ", tunnel->name);
533 printk(" %02X", ptr[offset]);
534 } while (++offset < length);
539 /* Get length of L2TP packet */
542 /* If type is control packet, it is handled by userspace. */
543 if (hdrflags & L2TP_HDRFLAG_T) {
544 PRINTK(tunnel->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
545 "%s: recv control packet, len=%d\n", tunnel->name, length);
552 /* If length is present, skip it */
553 if (hdrflags & L2TP_HDRFLAG_L)
556 /* Extract tunnel and session ID */
557 tunnel_id = ntohs(*(__be16 *) ptr);
559 session_id = ntohs(*(__be16 *) ptr);
562 /* Find the session context */
563 session = pppol2tp_session_find(tunnel, session_id);
565 /* Not found? Pass to userspace to deal with */
566 PRINTK(tunnel->debug, PPPOL2TP_MSG_DATA, KERN_INFO,
567 "%s: no socket found (%hu/%hu). Passing up.\n",
568 tunnel->name, tunnel_id, session_id);
571 sock_hold(session->sock);
573 /* The ref count on the socket was increased by the above call since
574 * we now hold a pointer to the session. Take care to do sock_put()
575 * when exiting this function from now on...
578 /* Handle the optional sequence numbers. If we are the LAC,
579 * enable/disable sequence numbers under the control of the LNS. If
580 * no sequence numbers present but we were expecting them, discard
583 if (hdrflags & L2TP_HDRFLAG_S) {
585 ns = ntohs(*(__be16 *) ptr);
587 nr = ntohs(*(__be16 *) ptr);
590 /* Received a packet with sequence numbers. If we're the LNS,
591 * check if we sre sending sequence numbers and if not,
594 if ((!session->lns_mode) && (!session->send_seq)) {
595 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_INFO,
596 "%s: requested to enable seq numbers by LNS\n",
598 session->send_seq = -1;
601 /* Store L2TP info in the skb */
602 PPPOL2TP_SKB_CB(skb)->ns = ns;
603 PPPOL2TP_SKB_CB(skb)->nr = nr;
604 PPPOL2TP_SKB_CB(skb)->has_seq = 1;
606 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
607 "%s: recv data ns=%hu, nr=%hu, session nr=%hu\n",
608 session->name, ns, nr, session->nr);
610 /* No sequence numbers.
611 * If user has configured mandatory sequence numbers, discard.
613 if (session->recv_seq) {
614 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_WARNING,
615 "%s: recv data has no seq numbers when required. "
616 "Discarding\n", session->name);
617 session->stats.rx_seq_discards++;
621 /* If we're the LAC and we're sending sequence numbers, the
622 * LNS has requested that we no longer send sequence numbers.
623 * If we're the LNS and we're sending sequence numbers, the
624 * LAC is broken. Discard the frame.
626 if ((!session->lns_mode) && (session->send_seq)) {
627 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_INFO,
628 "%s: requested to disable seq numbers by LNS\n",
630 session->send_seq = 0;
631 } else if (session->send_seq) {
632 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_WARNING,
633 "%s: recv data has no seq numbers when required. "
634 "Discarding\n", session->name);
635 session->stats.rx_seq_discards++;
639 /* Store L2TP info in the skb */
640 PPPOL2TP_SKB_CB(skb)->has_seq = 0;
643 /* If offset bit set, skip it. */
644 if (hdrflags & L2TP_HDRFLAG_O) {
645 offset = ntohs(*(__be16 *)ptr);
650 if (!pskb_may_pull(skb, offset))
653 __skb_pull(skb, offset);
655 /* Skip PPP header, if present. In testing, Microsoft L2TP clients
656 * don't send the PPP header (PPP header compression enabled), but
657 * other clients can include the header. So we cope with both cases
658 * here. The PPP header is always FF03 when using L2TP.
660 * Note that skb->data[] isn't dereferenced from a u16 ptr here since
661 * the field may be unaligned.
663 if (!pskb_may_pull(skb, 2))
666 if ((skb->data[0] == 0xff) && (skb->data[1] == 0x03))
669 /* Prepare skb for adding to the session's reorder_q. Hold
670 * packets for max reorder_timeout or 1 second if not
673 PPPOL2TP_SKB_CB(skb)->length = length;
674 PPPOL2TP_SKB_CB(skb)->expires = jiffies +
675 (session->reorder_timeout ? session->reorder_timeout : HZ);
677 /* Add packet to the session's receive queue. Reordering is done here, if
678 * enabled. Saved L2TP protocol info is stored in skb->sb[].
680 if (PPPOL2TP_SKB_CB(skb)->has_seq) {
681 if (session->reorder_timeout != 0) {
682 /* Packet reordering enabled. Add skb to session's
683 * reorder queue, in order of ns.
685 pppol2tp_recv_queue_skb(session, skb);
687 /* Packet reordering disabled. Discard out-of-sequence
690 if (PPPOL2TP_SKB_CB(skb)->ns != session->nr) {
691 session->stats.rx_seq_discards++;
692 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
693 "%s: oos pkt %hu len %d discarded, "
694 "waiting for %hu, reorder_q_len=%d\n",
695 session->name, PPPOL2TP_SKB_CB(skb)->ns,
696 PPPOL2TP_SKB_CB(skb)->length, session->nr,
697 skb_queue_len(&session->reorder_q));
700 skb_queue_tail(&session->reorder_q, skb);
703 /* No sequence numbers. Add the skb to the tail of the
704 * reorder queue. This ensures that it will be
705 * delivered after all previous sequenced skbs.
707 skb_queue_tail(&session->reorder_q, skb);
710 /* Try to dequeue as many skbs from reorder_q as we can. */
711 pppol2tp_recv_dequeue(session);
716 session->stats.rx_errors++;
718 sock_put(session->sock);
723 /* Put UDP header back */
724 __skb_push(skb, sizeof(struct udphdr));
730 /* UDP encapsulation receive handler. See net/ipv4/udp.c.
734 * >0: skb should be passed up to userspace as UDP.
736 static int pppol2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
738 struct pppol2tp_tunnel *tunnel;
740 tunnel = pppol2tp_sock_to_tunnel(sk);
744 PRINTK(tunnel->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
745 "%s: received %d bytes\n", tunnel->name, skb->len);
747 if (pppol2tp_recv_core(sk, skb))
756 /* Receive message. This is the recvmsg for the PPPoL2TP socket.
758 static int pppol2tp_recvmsg(struct kiocb *iocb, struct socket *sock,
759 struct msghdr *msg, size_t len,
764 struct sock *sk = sock->sk;
767 if (sk->sk_state & PPPOX_BOUND)
770 msg->msg_namelen = 0;
773 skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
774 flags & MSG_DONTWAIT, &err);
776 err = memcpy_toiovec(msg->msg_iov, (unsigned char *) skb->data,
788 /************************************************************************
790 ***********************************************************************/
792 /* Tell how big L2TP headers are for a particular session. This
793 * depends on whether sequence numbers are being used.
795 static inline int pppol2tp_l2tp_header_len(struct pppol2tp_session *session)
797 if (session->send_seq)
798 return PPPOL2TP_L2TP_HDR_SIZE_SEQ;
800 return PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
803 /* Build an L2TP header for the session into the buffer provided.
805 static void pppol2tp_build_l2tp_header(struct pppol2tp_session *session,
809 u16 flags = L2TP_HDR_VER;
811 if (session->send_seq)
812 flags |= L2TP_HDRFLAG_S;
814 /* Setup L2TP header.
815 * FIXME: Can this ever be unaligned? Is direct dereferencing of
816 * 16-bit header fields safe here for all architectures?
818 *bufp++ = htons(flags);
819 *bufp++ = htons(session->tunnel_addr.d_tunnel);
820 *bufp++ = htons(session->tunnel_addr.d_session);
821 if (session->send_seq) {
822 *bufp++ = htons(session->ns);
825 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
826 "%s: updated ns to %hu\n", session->name, session->ns);
830 /* This is the sendmsg for the PPPoL2TP pppol2tp_session socket. We come here
831 * when a user application does a sendmsg() on the session socket. L2TP and
832 * PPP headers must be inserted into the user's data.
834 static int pppol2tp_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
837 static const unsigned char ppph[2] = { 0xff, 0x03 };
838 struct sock *sk = sock->sk;
839 struct inet_sock *inet;
844 struct pppol2tp_session *session;
845 struct pppol2tp_tunnel *tunnel;
850 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
853 /* Get session and tunnel contexts */
855 session = pppol2tp_sock_to_session(sk);
859 tunnel = pppol2tp_sock_to_tunnel(session->tunnel_sock);
863 /* What header length is configured for this session? */
864 hdr_len = pppol2tp_l2tp_header_len(session);
866 /* Allocate a socket buffer */
868 skb = sock_wmalloc(sk, NET_SKB_PAD + sizeof(struct iphdr) +
869 sizeof(struct udphdr) + hdr_len +
870 sizeof(ppph) + total_len,
875 /* Reserve space for headers. */
876 skb_reserve(skb, NET_SKB_PAD);
877 skb_reset_network_header(skb);
878 skb_reserve(skb, sizeof(struct iphdr));
879 skb_reset_transport_header(skb);
881 /* Build UDP header */
882 inet = inet_sk(session->tunnel_sock);
883 uh = (struct udphdr *) skb->data;
884 uh->source = inet->sport;
885 uh->dest = inet->dport;
886 uh->len = htons(hdr_len + sizeof(ppph) + total_len);
888 skb_put(skb, sizeof(struct udphdr));
890 /* Build L2TP header */
891 pppol2tp_build_l2tp_header(session, skb->data);
892 skb_put(skb, hdr_len);
895 skb->data[0] = ppph[0];
896 skb->data[1] = ppph[1];
899 /* Copy user data into skb */
900 error = memcpy_fromiovec(skb->data, m->msg_iov, total_len);
905 skb_put(skb, total_len);
907 /* Calculate UDP checksum if configured to do so */
908 if (session->tunnel_sock->sk_no_check != UDP_CSUM_NOXMIT)
909 csum = udp_csum_outgoing(sk, skb);
912 if (session->send_seq)
913 PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
914 "%s: send %Zd bytes, ns=%hu\n", session->name,
915 total_len, session->ns - 1);
917 PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
918 "%s: send %Zd bytes\n", session->name, total_len);
920 if (session->debug & PPPOL2TP_MSG_DATA) {
922 unsigned char *datap = skb->data;
924 printk(KERN_DEBUG "%s: xmit:", session->name);
925 for (i = 0; i < total_len; i++) {
926 printk(" %02X", *datap++);
935 /* Queue the packet to IP for output */
937 error = ip_queue_xmit(skb, 1);
941 tunnel->stats.tx_packets++;
942 tunnel->stats.tx_bytes += len;
943 session->stats.tx_packets++;
944 session->stats.tx_bytes += len;
946 tunnel->stats.tx_errors++;
947 session->stats.tx_errors++;
954 /* Transmit function called by generic PPP driver. Sends PPP frame
955 * over PPPoL2TP socket.
957 * This is almost the same as pppol2tp_sendmsg(), but rather than
958 * being called with a msghdr from userspace, it is called with a skb
961 * The supplied skb from ppp doesn't have enough headroom for the
962 * insertion of L2TP, UDP and IP headers so we need to allocate more
963 * headroom in the skb. This will create a cloned skb. But we must be
964 * careful in the error case because the caller will expect to free
965 * the skb it supplied, not our cloned skb. So we take care to always
966 * leave the original skb unfreed if we return an error.
968 static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
970 static const u8 ppph[2] = { 0xff, 0x03 };
971 struct sock *sk = (struct sock *) chan->private;
974 struct pppol2tp_session *session;
975 struct pppol2tp_tunnel *tunnel;
978 int data_len = skb->len;
979 struct inet_sock *inet;
986 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
989 /* Get session and tunnel contexts from the socket */
990 session = pppol2tp_sock_to_session(sk);
994 sk_tun = session->tunnel_sock;
997 tunnel = pppol2tp_sock_to_tunnel(sk_tun);
1001 /* What header length is configured for this session? */
1002 hdr_len = pppol2tp_l2tp_header_len(session);
1004 /* Check that there's enough headroom in the skb to insert IP,
1005 * UDP and L2TP and PPP headers. If not enough, expand it to
1006 * make room. Adjust truesize.
1008 headroom = NET_SKB_PAD + sizeof(struct iphdr) +
1009 sizeof(struct udphdr) + hdr_len + sizeof(ppph);
1010 old_headroom = skb_headroom(skb);
1011 if (skb_cow_head(skb, headroom))
1014 new_headroom = skb_headroom(skb);
1016 skb->truesize += new_headroom - old_headroom;
1018 /* Setup PPP header */
1019 __skb_push(skb, sizeof(ppph));
1020 skb->data[0] = ppph[0];
1021 skb->data[1] = ppph[1];
1023 /* Setup L2TP header */
1024 pppol2tp_build_l2tp_header(session, __skb_push(skb, hdr_len));
1026 /* Setup UDP header */
1027 inet = inet_sk(sk_tun);
1028 __skb_push(skb, sizeof(*uh));
1029 skb_reset_transport_header(skb);
1031 uh->source = inet->sport;
1032 uh->dest = inet->dport;
1033 uh->len = htons(sizeof(struct udphdr) + hdr_len + sizeof(ppph) + data_len);
1036 /* *BROKEN* Calculate UDP checksum if configured to do so */
1037 if (sk_tun->sk_no_check != UDP_CSUM_NOXMIT)
1038 csum = udp_csum_outgoing(sk_tun, skb);
1041 if (session->send_seq)
1042 PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
1043 "%s: send %d bytes, ns=%hu\n", session->name,
1044 data_len, session->ns - 1);
1046 PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
1047 "%s: send %d bytes\n", session->name, data_len);
1049 if (session->debug & PPPOL2TP_MSG_DATA) {
1051 unsigned char *datap = skb->data;
1053 printk(KERN_DEBUG "%s: xmit:", session->name);
1054 for (i = 0; i < data_len; i++) {
1055 printk(" %02X", *datap++);
1064 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1065 IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED |
1069 /* Get routing info from the tunnel socket */
1070 dst_release(skb->dst);
1071 skb->dst = dst_clone(__sk_dst_get(sk_tun));
1074 /* Queue the packet to IP for output */
1076 rc = ip_queue_xmit(skb, 1);
1080 tunnel->stats.tx_packets++;
1081 tunnel->stats.tx_bytes += len;
1082 session->stats.tx_packets++;
1083 session->stats.tx_bytes += len;
1085 tunnel->stats.tx_errors++;
1086 session->stats.tx_errors++;
1092 /* Free the original skb */
1097 /*****************************************************************************
1098 * Session (and tunnel control) socket create/destroy.
1099 *****************************************************************************/
1101 /* When the tunnel UDP socket is closed, all the attached sockets need to go
1104 static void pppol2tp_tunnel_closeall(struct pppol2tp_tunnel *tunnel)
1107 struct hlist_node *walk;
1108 struct hlist_node *tmp;
1109 struct pppol2tp_session *session;
1115 PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1116 "%s: closing all sessions...\n", tunnel->name);
1118 write_lock_bh(&tunnel->hlist_lock);
1119 for (hash = 0; hash < PPPOL2TP_HASH_SIZE; hash++) {
1121 hlist_for_each_safe(walk, tmp, &tunnel->session_hlist[hash]) {
1122 struct sk_buff *skb;
1124 session = hlist_entry(walk, struct pppol2tp_session, hlist);
1128 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1129 "%s: closing session\n", session->name);
1131 hlist_del_init(&session->hlist);
1133 /* Since we should hold the sock lock while
1134 * doing any unbinding, we need to release the
1135 * lock we're holding before taking that lock.
1136 * Hold a reference to the sock so it doesn't
1137 * disappear as we're jumping between locks.
1140 write_unlock_bh(&tunnel->hlist_lock);
1143 if (sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND)) {
1144 pppox_unbind_sock(sk);
1145 sk->sk_state = PPPOX_DEAD;
1146 sk->sk_state_change(sk);
1149 /* Purge any queued data */
1150 skb_queue_purge(&sk->sk_receive_queue);
1151 skb_queue_purge(&sk->sk_write_queue);
1152 while ((skb = skb_dequeue(&session->reorder_q))) {
1160 /* Now restart from the beginning of this hash
1161 * chain. We always remove a session from the
1162 * list so we are guaranteed to make forward
1165 write_lock_bh(&tunnel->hlist_lock);
1169 write_unlock_bh(&tunnel->hlist_lock);
1172 /* Really kill the tunnel.
1173 * Come here only when all sessions have been cleared from the tunnel.
1175 static void pppol2tp_tunnel_free(struct pppol2tp_tunnel *tunnel)
1177 /* Remove from socket list */
1178 write_lock_bh(&pppol2tp_tunnel_list_lock);
1179 list_del_init(&tunnel->list);
1180 write_unlock_bh(&pppol2tp_tunnel_list_lock);
1182 atomic_dec(&pppol2tp_tunnel_count);
1186 /* Tunnel UDP socket destruct hook.
1187 * The tunnel context is deleted only when all session sockets have been
1190 static void pppol2tp_tunnel_destruct(struct sock *sk)
1192 struct pppol2tp_tunnel *tunnel;
1194 tunnel = pppol2tp_sock_to_tunnel(sk);
1198 PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1199 "%s: closing...\n", tunnel->name);
1201 /* Close all sessions */
1202 pppol2tp_tunnel_closeall(tunnel);
1204 /* No longer an encapsulation socket. See net/ipv4/udp.c */
1205 (udp_sk(sk))->encap_type = 0;
1206 (udp_sk(sk))->encap_rcv = NULL;
1208 /* Remove hooks into tunnel socket */
1209 tunnel->sock = NULL;
1210 sk->sk_destruct = tunnel->old_sk_destruct;
1211 sk->sk_user_data = NULL;
1213 /* Call original (UDP) socket descructor */
1214 if (sk->sk_destruct != NULL)
1215 (*sk->sk_destruct)(sk);
1217 pppol2tp_tunnel_dec_refcount(tunnel);
1223 /* Really kill the session socket. (Called from sock_put() if
1226 static void pppol2tp_session_destruct(struct sock *sk)
1228 struct pppol2tp_session *session = NULL;
1230 if (sk->sk_user_data != NULL) {
1231 struct pppol2tp_tunnel *tunnel;
1233 session = pppol2tp_sock_to_session(sk);
1234 if (session == NULL)
1237 /* Don't use pppol2tp_sock_to_tunnel() here to
1238 * get the tunnel context because the tunnel
1239 * socket might have already been closed (its
1240 * sk->sk_user_data will be NULL) so use the
1241 * session's private tunnel ptr instead.
1243 tunnel = session->tunnel;
1244 if (tunnel != NULL) {
1245 BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);
1247 /* If session_id is zero, this is a null
1248 * session context, which was created for a
1249 * socket that is being used only to manage
1252 if (session->tunnel_addr.s_session != 0) {
1253 /* Delete the session socket from the
1256 write_lock_bh(&tunnel->hlist_lock);
1257 hlist_del_init(&session->hlist);
1258 write_unlock_bh(&tunnel->hlist_lock);
1260 atomic_dec(&pppol2tp_session_count);
1263 /* This will delete the tunnel context if this
1264 * is the last session on the tunnel.
1266 session->tunnel = NULL;
1267 session->tunnel_sock = NULL;
1268 pppol2tp_tunnel_dec_refcount(tunnel);
1277 /* Called when the PPPoX socket (session) is closed.
1279 static int pppol2tp_release(struct socket *sock)
1281 struct sock *sk = sock->sk;
1289 if (sock_flag(sk, SOCK_DEAD) != 0)
1292 pppox_unbind_sock(sk);
1294 /* Signal the death of the socket. */
1295 sk->sk_state = PPPOX_DEAD;
1299 /* Purge any queued data */
1300 skb_queue_purge(&sk->sk_receive_queue);
1301 skb_queue_purge(&sk->sk_write_queue);
1305 /* This will delete the session context via
1306 * pppol2tp_session_destruct() if the socket's refcnt drops to
1318 /* Internal function to prepare a tunnel (UDP) socket to have PPPoX
1319 * sockets attached to it.
1321 static struct sock *pppol2tp_prepare_tunnel_socket(int fd, u16 tunnel_id,
1325 struct socket *sock = NULL;
1327 struct pppol2tp_tunnel *tunnel;
1328 struct sock *ret = NULL;
1330 /* Get the tunnel UDP socket from the fd, which was opened by
1331 * the userspace L2TP daemon.
1334 sock = sockfd_lookup(fd, &err);
1336 PRINTK(-1, PPPOL2TP_MSG_CONTROL, KERN_ERR,
1337 "tunl %hu: sockfd_lookup(fd=%d) returned %d\n",
1338 tunnel_id, fd, err);
1344 /* Quick sanity checks */
1345 err = -EPROTONOSUPPORT;
1346 if (sk->sk_protocol != IPPROTO_UDP) {
1347 PRINTK(-1, PPPOL2TP_MSG_CONTROL, KERN_ERR,
1348 "tunl %hu: fd %d wrong protocol, got %d, expected %d\n",
1349 tunnel_id, fd, sk->sk_protocol, IPPROTO_UDP);
1352 err = -EAFNOSUPPORT;
1353 if (sock->ops->family != AF_INET) {
1354 PRINTK(-1, PPPOL2TP_MSG_CONTROL, KERN_ERR,
1355 "tunl %hu: fd %d wrong family, got %d, expected %d\n",
1356 tunnel_id, fd, sock->ops->family, AF_INET);
1362 /* Check if this socket has already been prepped */
1363 tunnel = (struct pppol2tp_tunnel *)sk->sk_user_data;
1364 if (tunnel != NULL) {
1365 /* User-data field already set */
1367 BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);
1369 /* This socket has already been prepped */
1374 /* This socket is available and needs prepping. Create a new tunnel
1375 * context and init it.
1377 sk->sk_user_data = tunnel = kzalloc(sizeof(struct pppol2tp_tunnel), GFP_KERNEL);
1378 if (sk->sk_user_data == NULL) {
1383 tunnel->magic = L2TP_TUNNEL_MAGIC;
1384 sprintf(&tunnel->name[0], "tunl %hu", tunnel_id);
1386 tunnel->stats.tunnel_id = tunnel_id;
1387 tunnel->debug = PPPOL2TP_DEFAULT_DEBUG_FLAGS;
1389 /* Hook on the tunnel socket destructor so that we can cleanup
1390 * if the tunnel socket goes away.
1392 tunnel->old_sk_destruct = sk->sk_destruct;
1393 sk->sk_destruct = &pppol2tp_tunnel_destruct;
1396 sk->sk_allocation = GFP_ATOMIC;
1399 rwlock_init(&tunnel->hlist_lock);
1401 /* Add tunnel to our list */
1402 INIT_LIST_HEAD(&tunnel->list);
1403 write_lock_bh(&pppol2tp_tunnel_list_lock);
1404 list_add(&tunnel->list, &pppol2tp_tunnel_list);
1405 write_unlock_bh(&pppol2tp_tunnel_list_lock);
1406 atomic_inc(&pppol2tp_tunnel_count);
1408 /* Bump the reference count. The tunnel context is deleted
1409 * only when this drops to zero.
1411 pppol2tp_tunnel_inc_refcount(tunnel);
1413 /* Mark socket as an encapsulation socket. See net/ipv4/udp.c */
1414 (udp_sk(sk))->encap_type = UDP_ENCAP_L2TPINUDP;
1415 (udp_sk(sk))->encap_rcv = pppol2tp_udp_encap_recv;
1431 static struct proto pppol2tp_sk_proto = {
1433 .owner = THIS_MODULE,
1434 .obj_size = sizeof(struct pppox_sock),
1437 /* socket() handler. Initialize a new struct sock.
1439 static int pppol2tp_create(struct net *net, struct socket *sock)
1441 int error = -ENOMEM;
1444 sk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, &pppol2tp_sk_proto);
1448 sock_init_data(sock, sk);
1450 sock->state = SS_UNCONNECTED;
1451 sock->ops = &pppol2tp_ops;
1453 sk->sk_backlog_rcv = pppol2tp_recv_core;
1454 sk->sk_protocol = PX_PROTO_OL2TP;
1455 sk->sk_family = PF_PPPOX;
1456 sk->sk_state = PPPOX_NONE;
1457 sk->sk_type = SOCK_STREAM;
1458 sk->sk_destruct = pppol2tp_session_destruct;
1466 /* connect() handler. Attach a PPPoX socket to a tunnel UDP socket
1468 static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr,
1469 int sockaddr_len, int flags)
1471 struct sock *sk = sock->sk;
1472 struct sockaddr_pppol2tp *sp = (struct sockaddr_pppol2tp *) uservaddr;
1473 struct pppox_sock *po = pppox_sk(sk);
1474 struct sock *tunnel_sock = NULL;
1475 struct pppol2tp_session *session = NULL;
1476 struct pppol2tp_tunnel *tunnel;
1477 struct dst_entry *dst;
1483 if (sp->sa_protocol != PX_PROTO_OL2TP)
1486 /* Check for already bound sockets */
1488 if (sk->sk_state & PPPOX_CONNECTED)
1491 /* We don't supporting rebinding anyway */
1493 if (sk->sk_user_data)
1494 goto end; /* socket is already attached */
1496 /* Don't bind if s_tunnel is 0 */
1498 if (sp->pppol2tp.s_tunnel == 0)
1501 /* Special case: prepare tunnel socket if s_session and
1502 * d_session is 0. Otherwise look up tunnel using supplied
1505 if ((sp->pppol2tp.s_session == 0) && (sp->pppol2tp.d_session == 0)) {
1506 tunnel_sock = pppol2tp_prepare_tunnel_socket(sp->pppol2tp.fd,
1507 sp->pppol2tp.s_tunnel,
1509 if (tunnel_sock == NULL)
1512 tunnel = tunnel_sock->sk_user_data;
1514 tunnel = pppol2tp_tunnel_find(sp->pppol2tp.s_tunnel);
1516 /* Error if we can't find the tunnel */
1521 tunnel_sock = tunnel->sock;
1524 /* Check that this session doesn't already exist */
1526 session = pppol2tp_session_find(tunnel, sp->pppol2tp.s_session);
1527 if (session != NULL)
1530 /* Allocate and initialize a new session context. */
1531 session = kzalloc(sizeof(struct pppol2tp_session), GFP_KERNEL);
1532 if (session == NULL) {
1537 skb_queue_head_init(&session->reorder_q);
1539 session->magic = L2TP_SESSION_MAGIC;
1540 session->owner = current->pid;
1542 session->tunnel = tunnel;
1543 session->tunnel_sock = tunnel_sock;
1544 session->tunnel_addr = sp->pppol2tp;
1545 sprintf(&session->name[0], "sess %hu/%hu",
1546 session->tunnel_addr.s_tunnel,
1547 session->tunnel_addr.s_session);
1549 session->stats.tunnel_id = session->tunnel_addr.s_tunnel;
1550 session->stats.session_id = session->tunnel_addr.s_session;
1552 INIT_HLIST_NODE(&session->hlist);
1554 /* Inherit debug options from tunnel */
1555 session->debug = tunnel->debug;
1557 /* Default MTU must allow space for UDP/L2TP/PPP
1560 session->mtu = session->mru = 1500 - PPPOL2TP_HEADER_OVERHEAD;
1562 /* If PMTU discovery was enabled, use the MTU that was discovered */
1563 dst = sk_dst_get(sk);
1565 u32 pmtu = dst_mtu(__sk_dst_get(sk));
1567 session->mtu = session->mru = pmtu -
1568 PPPOL2TP_HEADER_OVERHEAD;
1572 /* Special case: if source & dest session_id == 0x0000, this socket is
1573 * being created to manage the tunnel. Don't add the session to the
1574 * session hash list, just set up the internal context for use by
1575 * ioctl() and sockopt() handlers.
1577 if ((session->tunnel_addr.s_session == 0) &&
1578 (session->tunnel_addr.d_session == 0)) {
1580 sk->sk_user_data = session;
1584 /* Get tunnel context from the tunnel socket */
1585 tunnel = pppol2tp_sock_to_tunnel(tunnel_sock);
1586 if (tunnel == NULL) {
1591 /* Right now, because we don't have a way to push the incoming skb's
1592 * straight through the UDP layer, the only header we need to worry
1593 * about is the L2TP header. This size is different depending on
1594 * whether sequence numbers are enabled for the data channel.
1596 po->chan.hdrlen = PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
1598 po->chan.private = sk;
1599 po->chan.ops = &pppol2tp_chan_ops;
1600 po->chan.mtu = session->mtu;
1602 error = ppp_register_channel(&po->chan);
1606 /* This is how we get the session context from the socket. */
1607 sk->sk_user_data = session;
1609 /* Add session to the tunnel's hash list */
1610 write_lock_bh(&tunnel->hlist_lock);
1611 hlist_add_head(&session->hlist,
1612 pppol2tp_session_id_hash(tunnel,
1613 session->tunnel_addr.s_session));
1614 write_unlock_bh(&tunnel->hlist_lock);
1616 atomic_inc(&pppol2tp_session_count);
1619 pppol2tp_tunnel_inc_refcount(tunnel);
1620 sk->sk_state = PPPOX_CONNECTED;
1621 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1622 "%s: created\n", session->name);
1629 PRINTK(session->debug,
1630 PPPOL2TP_MSG_CONTROL, KERN_WARNING,
1631 "%s: connect failed: %d\n",
1632 session->name, error);
1634 PRINTK(-1, PPPOL2TP_MSG_CONTROL, KERN_WARNING,
1635 "connect failed: %d\n", error);
1641 /* getname() support.
1643 static int pppol2tp_getname(struct socket *sock, struct sockaddr *uaddr,
1644 int *usockaddr_len, int peer)
1646 int len = sizeof(struct sockaddr_pppol2tp);
1647 struct sockaddr_pppol2tp sp;
1649 struct pppol2tp_session *session;
1652 if (sock->sk->sk_state != PPPOX_CONNECTED)
1655 session = pppol2tp_sock_to_session(sock->sk);
1656 if (session == NULL) {
1661 sp.sa_family = AF_PPPOX;
1662 sp.sa_protocol = PX_PROTO_OL2TP;
1663 memcpy(&sp.pppol2tp, &session->tunnel_addr,
1664 sizeof(struct pppol2tp_addr));
1666 memcpy(uaddr, &sp, len);
1668 *usockaddr_len = len;
1676 /****************************************************************************
1679 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
1680 * sockets. However, in order to control kernel tunnel features, we allow
1681 * userspace to create a special "tunnel" PPPoX socket which is used for
1682 * control only. Tunnel PPPoX sockets have session_id == 0 and simply allow
1683 * the user application to issue L2TP setsockopt(), getsockopt() and ioctl()
1685 ****************************************************************************/
1687 /* Session ioctl helper.
1689 static int pppol2tp_session_ioctl(struct pppol2tp_session *session,
1690 unsigned int cmd, unsigned long arg)
1694 struct sock *sk = session->sock;
1695 int val = (int) arg;
1697 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_DEBUG,
1698 "%s: pppol2tp_session_ioctl(cmd=%#x, arg=%#lx)\n",
1699 session->name, cmd, arg);
1706 if (!(sk->sk_state & PPPOX_CONNECTED))
1710 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq)))
1712 ifr.ifr_mtu = session->mtu;
1713 if (copy_to_user((void __user *) arg, &ifr, sizeof(struct ifreq)))
1716 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1717 "%s: get mtu=%d\n", session->name, session->mtu);
1723 if (!(sk->sk_state & PPPOX_CONNECTED))
1727 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq)))
1730 session->mtu = ifr.ifr_mtu;
1732 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1733 "%s: set mtu=%d\n", session->name, session->mtu);
1739 if (!(sk->sk_state & PPPOX_CONNECTED))
1743 if (put_user(session->mru, (int __user *) arg))
1746 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1747 "%s: get mru=%d\n", session->name, session->mru);
1753 if (!(sk->sk_state & PPPOX_CONNECTED))
1757 if (get_user(val,(int __user *) arg))
1761 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1762 "%s: set mru=%d\n", session->name, session->mru);
1768 if (put_user(session->flags, (int __user *) arg))
1771 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1772 "%s: get flags=%d\n", session->name, session->flags);
1778 if (get_user(val, (int __user *) arg))
1780 session->flags = val;
1781 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1782 "%s: set flags=%d\n", session->name, session->flags);
1786 case PPPIOCGL2TPSTATS:
1788 if (!(sk->sk_state & PPPOX_CONNECTED))
1791 if (copy_to_user((void __user *) arg, &session->stats,
1792 sizeof(session->stats)))
1794 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1795 "%s: get L2TP stats\n", session->name);
1809 /* Tunnel ioctl helper.
1811 * Note the special handling for PPPIOCGL2TPSTATS below. If the ioctl data
1812 * specifies a session_id, the session ioctl handler is called. This allows an
1813 * application to retrieve session stats via a tunnel socket.
1815 static int pppol2tp_tunnel_ioctl(struct pppol2tp_tunnel *tunnel,
1816 unsigned int cmd, unsigned long arg)
1819 struct sock *sk = tunnel->sock;
1820 struct pppol2tp_ioc_stats stats_req;
1822 PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_DEBUG,
1823 "%s: pppol2tp_tunnel_ioctl(cmd=%#x, arg=%#lx)\n", tunnel->name,
1829 case PPPIOCGL2TPSTATS:
1831 if (!(sk->sk_state & PPPOX_CONNECTED))
1834 if (copy_from_user(&stats_req, (void __user *) arg,
1835 sizeof(stats_req))) {
1839 if (stats_req.session_id != 0) {
1840 /* resend to session ioctl handler */
1841 struct pppol2tp_session *session =
1842 pppol2tp_session_find(tunnel, stats_req.session_id);
1843 if (session != NULL)
1844 err = pppol2tp_session_ioctl(session, cmd, arg);
1850 tunnel->stats.using_ipsec = (sk->sk_policy[0] || sk->sk_policy[1]) ? 1 : 0;
1852 if (copy_to_user((void __user *) arg, &tunnel->stats,
1853 sizeof(tunnel->stats))) {
1857 PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1858 "%s: get L2TP stats\n", tunnel->name);
1872 /* Main ioctl() handler.
1873 * Dispatch to tunnel or session helpers depending on the socket.
1875 static int pppol2tp_ioctl(struct socket *sock, unsigned int cmd,
1878 struct sock *sk = sock->sk;
1879 struct pppol2tp_session *session;
1880 struct pppol2tp_tunnel *tunnel;
1887 if (sock_flag(sk, SOCK_DEAD) != 0)
1891 if ((sk->sk_user_data == NULL) ||
1892 (!(sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND))))
1895 /* Get session context from the socket */
1897 session = pppol2tp_sock_to_session(sk);
1898 if (session == NULL)
1901 /* Special case: if session's session_id is zero, treat ioctl as a
1904 if ((session->tunnel_addr.s_session == 0) &&
1905 (session->tunnel_addr.d_session == 0)) {
1907 tunnel = pppol2tp_sock_to_tunnel(session->tunnel_sock);
1911 err = pppol2tp_tunnel_ioctl(tunnel, cmd, arg);
1915 err = pppol2tp_session_ioctl(session, cmd, arg);
1921 /*****************************************************************************
1922 * setsockopt() / getsockopt() support.
1924 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
1925 * sockets. In order to control kernel tunnel features, we allow userspace to
1926 * create a special "tunnel" PPPoX socket which is used for control only.
1927 * Tunnel PPPoX sockets have session_id == 0 and simply allow the user
1928 * application to issue L2TP setsockopt(), getsockopt() and ioctl() calls.
1929 *****************************************************************************/
1931 /* Tunnel setsockopt() helper.
1933 static int pppol2tp_tunnel_setsockopt(struct sock *sk,
1934 struct pppol2tp_tunnel *tunnel,
1935 int optname, int val)
1940 case PPPOL2TP_SO_DEBUG:
1941 tunnel->debug = val;
1942 PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1943 "%s: set debug=%x\n", tunnel->name, tunnel->debug);
1954 /* Session setsockopt helper.
1956 static int pppol2tp_session_setsockopt(struct sock *sk,
1957 struct pppol2tp_session *session,
1958 int optname, int val)
1963 case PPPOL2TP_SO_RECVSEQ:
1964 if ((val != 0) && (val != 1)) {
1968 session->recv_seq = val ? -1 : 0;
1969 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1970 "%s: set recv_seq=%d\n", session->name,
1974 case PPPOL2TP_SO_SENDSEQ:
1975 if ((val != 0) && (val != 1)) {
1979 session->send_seq = val ? -1 : 0;
1981 struct sock *ssk = session->sock;
1982 struct pppox_sock *po = pppox_sk(ssk);
1983 po->chan.hdrlen = val ? PPPOL2TP_L2TP_HDR_SIZE_SEQ :
1984 PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
1986 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1987 "%s: set send_seq=%d\n", session->name, session->send_seq);
1990 case PPPOL2TP_SO_LNSMODE:
1991 if ((val != 0) && (val != 1)) {
1995 session->lns_mode = val ? -1 : 0;
1996 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1997 "%s: set lns_mode=%d\n", session->name,
2001 case PPPOL2TP_SO_DEBUG:
2002 session->debug = val;
2003 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2004 "%s: set debug=%x\n", session->name, session->debug);
2007 case PPPOL2TP_SO_REORDERTO:
2008 session->reorder_timeout = msecs_to_jiffies(val);
2009 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2010 "%s: set reorder_timeout=%d\n", session->name,
2011 session->reorder_timeout);
2022 /* Main setsockopt() entry point.
2023 * Does API checks, then calls either the tunnel or session setsockopt
2024 * handler, according to whether the PPPoL2TP socket is a for a regular
2025 * session or the special tunnel type.
2027 static int pppol2tp_setsockopt(struct socket *sock, int level, int optname,
2028 char __user *optval, int optlen)
2030 struct sock *sk = sock->sk;
2031 struct pppol2tp_session *session = sk->sk_user_data;
2032 struct pppol2tp_tunnel *tunnel;
2036 if (level != SOL_PPPOL2TP)
2037 return udp_prot.setsockopt(sk, level, optname, optval, optlen);
2039 if (optlen < sizeof(int))
2042 if (get_user(val, (int __user *)optval))
2046 if (sk->sk_user_data == NULL)
2049 /* Get session context from the socket */
2051 session = pppol2tp_sock_to_session(sk);
2052 if (session == NULL)
2055 /* Special case: if session_id == 0x0000, treat as operation on tunnel
2057 if ((session->tunnel_addr.s_session == 0) &&
2058 (session->tunnel_addr.d_session == 0)) {
2060 tunnel = pppol2tp_sock_to_tunnel(session->tunnel_sock);
2064 err = pppol2tp_tunnel_setsockopt(sk, tunnel, optname, val);
2066 err = pppol2tp_session_setsockopt(sk, session, optname, val);
2074 /* Tunnel getsockopt helper. Called with sock locked.
2076 static int pppol2tp_tunnel_getsockopt(struct sock *sk,
2077 struct pppol2tp_tunnel *tunnel,
2078 int optname, int *val)
2083 case PPPOL2TP_SO_DEBUG:
2084 *val = tunnel->debug;
2085 PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2086 "%s: get debug=%x\n", tunnel->name, tunnel->debug);
2097 /* Session getsockopt helper. Called with sock locked.
2099 static int pppol2tp_session_getsockopt(struct sock *sk,
2100 struct pppol2tp_session *session,
2101 int optname, int *val)
2106 case PPPOL2TP_SO_RECVSEQ:
2107 *val = session->recv_seq;
2108 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2109 "%s: get recv_seq=%d\n", session->name, *val);
2112 case PPPOL2TP_SO_SENDSEQ:
2113 *val = session->send_seq;
2114 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2115 "%s: get send_seq=%d\n", session->name, *val);
2118 case PPPOL2TP_SO_LNSMODE:
2119 *val = session->lns_mode;
2120 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2121 "%s: get lns_mode=%d\n", session->name, *val);
2124 case PPPOL2TP_SO_DEBUG:
2125 *val = session->debug;
2126 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2127 "%s: get debug=%d\n", session->name, *val);
2130 case PPPOL2TP_SO_REORDERTO:
2131 *val = (int) jiffies_to_msecs(session->reorder_timeout);
2132 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2133 "%s: get reorder_timeout=%d\n", session->name, *val);
2143 /* Main getsockopt() entry point.
2144 * Does API checks, then calls either the tunnel or session getsockopt
2145 * handler, according to whether the PPPoX socket is a for a regular session
2146 * or the special tunnel type.
2148 static int pppol2tp_getsockopt(struct socket *sock, int level,
2149 int optname, char __user *optval, int __user *optlen)
2151 struct sock *sk = sock->sk;
2152 struct pppol2tp_session *session = sk->sk_user_data;
2153 struct pppol2tp_tunnel *tunnel;
2157 if (level != SOL_PPPOL2TP)
2158 return udp_prot.getsockopt(sk, level, optname, optval, optlen);
2160 if (get_user(len, (int __user *) optlen))
2163 len = min_t(unsigned int, len, sizeof(int));
2169 if (sk->sk_user_data == NULL)
2172 /* Get the session context */
2174 session = pppol2tp_sock_to_session(sk);
2175 if (session == NULL)
2178 /* Special case: if session_id == 0x0000, treat as operation on tunnel */
2179 if ((session->tunnel_addr.s_session == 0) &&
2180 (session->tunnel_addr.d_session == 0)) {
2182 tunnel = pppol2tp_sock_to_tunnel(session->tunnel_sock);
2186 err = pppol2tp_tunnel_getsockopt(sk, tunnel, optname, &val);
2188 err = pppol2tp_session_getsockopt(sk, session, optname, &val);
2191 if (put_user(len, (int __user *) optlen))
2194 if (copy_to_user((void __user *) optval, &val, len))
2202 /*****************************************************************************
2203 * /proc filesystem for debug
2204 *****************************************************************************/
2206 #ifdef CONFIG_PROC_FS
2208 #include <linux/seq_file.h>
2210 struct pppol2tp_seq_data {
2211 struct pppol2tp_tunnel *tunnel; /* current tunnel */
2212 struct pppol2tp_session *session; /* NULL means get first session in tunnel */
2215 static struct pppol2tp_session *next_session(struct pppol2tp_tunnel *tunnel, struct pppol2tp_session *curr)
2217 struct pppol2tp_session *session = NULL;
2218 struct hlist_node *walk;
2223 read_lock_bh(&tunnel->hlist_lock);
2224 for (i = 0; i < PPPOL2TP_HASH_SIZE; i++) {
2225 hlist_for_each_entry(session, walk, &tunnel->session_hlist[i], hlist) {
2230 if (session == curr) {
2241 read_unlock_bh(&tunnel->hlist_lock);
2248 static struct pppol2tp_tunnel *next_tunnel(struct pppol2tp_tunnel *curr)
2250 struct pppol2tp_tunnel *tunnel = NULL;
2252 read_lock_bh(&pppol2tp_tunnel_list_lock);
2253 if (list_is_last(&curr->list, &pppol2tp_tunnel_list)) {
2256 tunnel = list_entry(curr->list.next, struct pppol2tp_tunnel, list);
2258 read_unlock_bh(&pppol2tp_tunnel_list_lock);
2263 static void *pppol2tp_seq_start(struct seq_file *m, loff_t *offs)
2265 struct pppol2tp_seq_data *pd = SEQ_START_TOKEN;
2271 BUG_ON(m->private == NULL);
2274 if (pd->tunnel == NULL) {
2275 if (!list_empty(&pppol2tp_tunnel_list))
2276 pd->tunnel = list_entry(pppol2tp_tunnel_list.next, struct pppol2tp_tunnel, list);
2278 pd->session = next_session(pd->tunnel, pd->session);
2279 if (pd->session == NULL) {
2280 pd->tunnel = next_tunnel(pd->tunnel);
2284 /* NULL tunnel and session indicates end of list */
2285 if ((pd->tunnel == NULL) && (pd->session == NULL))
2292 static void *pppol2tp_seq_next(struct seq_file *m, void *v, loff_t *pos)
2298 static void pppol2tp_seq_stop(struct seq_file *p, void *v)
2303 static void pppol2tp_seq_tunnel_show(struct seq_file *m, void *v)
2305 struct pppol2tp_tunnel *tunnel = v;
2307 seq_printf(m, "\nTUNNEL '%s', %c %d\n",
2309 (tunnel == tunnel->sock->sk_user_data) ? 'Y':'N',
2310 atomic_read(&tunnel->ref_count) - 1);
2311 seq_printf(m, " %08x %llu/%llu/%llu %llu/%llu/%llu\n",
2313 (unsigned long long)tunnel->stats.tx_packets,
2314 (unsigned long long)tunnel->stats.tx_bytes,
2315 (unsigned long long)tunnel->stats.tx_errors,
2316 (unsigned long long)tunnel->stats.rx_packets,
2317 (unsigned long long)tunnel->stats.rx_bytes,
2318 (unsigned long long)tunnel->stats.rx_errors);
2321 static void pppol2tp_seq_session_show(struct seq_file *m, void *v)
2323 struct pppol2tp_session *session = v;
2325 seq_printf(m, " SESSION '%s' %08X/%d %04X/%04X -> "
2326 "%04X/%04X %d %c\n",
2328 ntohl(session->tunnel_addr.addr.sin_addr.s_addr),
2329 ntohs(session->tunnel_addr.addr.sin_port),
2330 session->tunnel_addr.s_tunnel,
2331 session->tunnel_addr.s_session,
2332 session->tunnel_addr.d_tunnel,
2333 session->tunnel_addr.d_session,
2334 session->sock->sk_state,
2335 (session == session->sock->sk_user_data) ?
2337 seq_printf(m, " %d/%d/%c/%c/%s %08x %u\n",
2338 session->mtu, session->mru,
2339 session->recv_seq ? 'R' : '-',
2340 session->send_seq ? 'S' : '-',
2341 session->lns_mode ? "LNS" : "LAC",
2343 jiffies_to_msecs(session->reorder_timeout));
2344 seq_printf(m, " %hu/%hu %llu/%llu/%llu %llu/%llu/%llu\n",
2345 session->nr, session->ns,
2346 (unsigned long long)session->stats.tx_packets,
2347 (unsigned long long)session->stats.tx_bytes,
2348 (unsigned long long)session->stats.tx_errors,
2349 (unsigned long long)session->stats.rx_packets,
2350 (unsigned long long)session->stats.rx_bytes,
2351 (unsigned long long)session->stats.rx_errors);
2354 static int pppol2tp_seq_show(struct seq_file *m, void *v)
2356 struct pppol2tp_seq_data *pd = v;
2358 /* display header on line 1 */
2359 if (v == SEQ_START_TOKEN) {
2360 seq_puts(m, "PPPoL2TP driver info, " PPPOL2TP_DRV_VERSION "\n");
2361 seq_puts(m, "TUNNEL name, user-data-ok session-count\n");
2362 seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
2363 seq_puts(m, " SESSION name, addr/port src-tid/sid "
2364 "dest-tid/sid state user-data-ok\n");
2365 seq_puts(m, " mtu/mru/rcvseq/sendseq/lns debug reorderto\n");
2366 seq_puts(m, " nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
2370 /* Show the tunnel or session context.
2372 if (pd->session == NULL)
2373 pppol2tp_seq_tunnel_show(m, pd->tunnel);
2375 pppol2tp_seq_session_show(m, pd->session);
2381 static struct seq_operations pppol2tp_seq_ops = {
2382 .start = pppol2tp_seq_start,
2383 .next = pppol2tp_seq_next,
2384 .stop = pppol2tp_seq_stop,
2385 .show = pppol2tp_seq_show,
2388 /* Called when our /proc file is opened. We allocate data for use when
2389 * iterating our tunnel / session contexts and store it in the private
2390 * data of the seq_file.
2392 static int pppol2tp_proc_open(struct inode *inode, struct file *file)
2395 struct pppol2tp_seq_data *pd;
2398 ret = seq_open(file, &pppol2tp_seq_ops);
2402 m = file->private_data;
2404 /* Allocate and fill our proc_data for access later */
2406 m->private = kzalloc(sizeof(struct pppol2tp_seq_data), GFP_KERNEL);
2407 if (m->private == NULL)
2417 /* Called when /proc file access completes.
2419 static int pppol2tp_proc_release(struct inode *inode, struct file *file)
2421 struct seq_file *m = (struct seq_file *)file->private_data;
2426 return seq_release(inode, file);
2429 static struct file_operations pppol2tp_proc_fops = {
2430 .owner = THIS_MODULE,
2431 .open = pppol2tp_proc_open,
2433 .llseek = seq_lseek,
2434 .release = pppol2tp_proc_release,
2437 static struct proc_dir_entry *pppol2tp_proc;
2439 #endif /* CONFIG_PROC_FS */
2441 /*****************************************************************************
2443 *****************************************************************************/
2445 static struct proto_ops pppol2tp_ops = {
2447 .owner = THIS_MODULE,
2448 .release = pppol2tp_release,
2449 .bind = sock_no_bind,
2450 .connect = pppol2tp_connect,
2451 .socketpair = sock_no_socketpair,
2452 .accept = sock_no_accept,
2453 .getname = pppol2tp_getname,
2454 .poll = datagram_poll,
2455 .listen = sock_no_listen,
2456 .shutdown = sock_no_shutdown,
2457 .setsockopt = pppol2tp_setsockopt,
2458 .getsockopt = pppol2tp_getsockopt,
2459 .sendmsg = pppol2tp_sendmsg,
2460 .recvmsg = pppol2tp_recvmsg,
2461 .mmap = sock_no_mmap,
2462 .ioctl = pppox_ioctl,
2465 static struct pppox_proto pppol2tp_proto = {
2466 .create = pppol2tp_create,
2467 .ioctl = pppol2tp_ioctl
2470 static int __init pppol2tp_init(void)
2474 err = proto_register(&pppol2tp_sk_proto, 0);
2477 err = register_pppox_proto(PX_PROTO_OL2TP, &pppol2tp_proto);
2479 goto out_unregister_pppol2tp_proto;
2481 #ifdef CONFIG_PROC_FS
2482 pppol2tp_proc = proc_net_fops_create(&init_net, "pppol2tp", 0,
2483 &pppol2tp_proc_fops);
2484 if (!pppol2tp_proc) {
2486 goto out_unregister_pppox_proto;
2488 #endif /* CONFIG_PROC_FS */
2489 printk(KERN_INFO "PPPoL2TP kernel driver, %s\n",
2490 PPPOL2TP_DRV_VERSION);
2494 #ifdef CONFIG_PROC_FS
2495 out_unregister_pppox_proto:
2496 unregister_pppox_proto(PX_PROTO_OL2TP);
2498 out_unregister_pppol2tp_proto:
2499 proto_unregister(&pppol2tp_sk_proto);
2503 static void __exit pppol2tp_exit(void)
2505 unregister_pppox_proto(PX_PROTO_OL2TP);
2507 #ifdef CONFIG_PROC_FS
2508 remove_proc_entry("pppol2tp", init_net.proc_net);
2510 proto_unregister(&pppol2tp_sk_proto);
2513 module_init(pppol2tp_init);
2514 module_exit(pppol2tp_exit);
2516 MODULE_AUTHOR("Martijn van Oosterhout <kleptog@svana.org>, "
2517 "James Chapman <jchapman@katalix.com>");
2518 MODULE_DESCRIPTION("PPP over L2TP over UDP");
2519 MODULE_LICENSE("GPL");
2520 MODULE_VERSION(PPPOL2TP_DRV_VERSION);