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drivers/char/Kconfig: don't mess it up for everyone else
[linux-2.6.32.60-moxart.git] / drivers / net / pppol2tp.c
blob92359019991af5aa91497a322852dc16653d635a
1 /*****************************************************************************
2 * Linux PPP over L2TP (PPPoX/PPPoL2TP) Sockets
3 *
4 * PPPoX --- Generic PPP encapsulation socket family
5 * PPPoL2TP --- PPP over L2TP (RFC 2661)
6 *
7 * Version: 1.0.0
8 *
9 * Authors: Martijn van Oosterhout <kleptog@svana.org>
10 * James Chapman (jchapman@katalix.com)
11 * Contributors:
12 * Michal Ostrowski <mostrows@speakeasy.net>
13 * Arnaldo Carvalho de Melo <acme@xconectiva.com.br>
14 * David S. Miller (davem@redhat.com)
15 *
16 * License:
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.
21 *
22 */
23
24 /* This driver handles only L2TP data frames; control frames are handled by a
25 * userspace application.
26 *
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.
32 *
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.
35 *
36 * Here's example userspace code to create a socket for sending/receiving data
37 * over an L2TP session:-
38 *
39 * struct sockaddr_pppol2tp sax;
40 * int fd;
41 * int session_fd;
42 *
43 * fd = socket(AF_PPPOX, SOCK_DGRAM, PX_PROTO_OL2TP);
44 *
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;
55 *
56 * session_fd = connect(fd, (struct sockaddr *)&sax, sizeof(sax));
57 *
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.
61 */
62
63 #include <linux/module.h>
64 #include <linux/string.h>
65 #include <linux/list.h>
66 #include <asm/uaccess.h>
67
68 #include <linux/kernel.h>
69 #include <linux/spinlock.h>
70 #include <linux/kthread.h>
71 #include <linux/sched.h>
72 #include <linux/slab.h>
73 #include <linux/errno.h>
74 #include <linux/jiffies.h>
75
76 #include <linux/netdevice.h>
77 #include <linux/net.h>
78 #include <linux/inetdevice.h>
79 #include <linux/skbuff.h>
80 #include <linux/init.h>
81 #include <linux/ip.h>
82 #include <linux/udp.h>
83 #include <linux/if_pppox.h>
84 #include <linux/if_pppol2tp.h>
85 #include <net/sock.h>
86 #include <linux/ppp_channel.h>
87 #include <linux/ppp_defs.h>
88 #include <linux/if_ppp.h>
89 #include <linux/file.h>
90 #include <linux/hash.h>
91 #include <linux/sort.h>
92 #include <linux/proc_fs.h>
93 #include <linux/nsproxy.h>
94 #include <net/net_namespace.h>
95 #include <net/netns/generic.h>
96 #include <net/dst.h>
97 #include <net/ip.h>
98 #include <net/udp.h>
99 #include <net/xfrm.h>
100
101 #include <asm/byteorder.h>
102 #include <asm/atomic.h>
103
104
105 #define PPPOL2TP_DRV_VERSION "V1.0"
106
107 /* L2TP header constants */
108 #define L2TP_HDRFLAG_T 0x8000
109 #define L2TP_HDRFLAG_L 0x4000
110 #define L2TP_HDRFLAG_S 0x0800
111 #define L2TP_HDRFLAG_O 0x0200
112 #define L2TP_HDRFLAG_P 0x0100
113
114 #define L2TP_HDR_VER_MASK 0x000F
115 #define L2TP_HDR_VER 0x0002
116
117 /* Space for UDP, L2TP and PPP headers */
118 #define PPPOL2TP_HEADER_OVERHEAD 40
119
120 /* Just some random numbers */
121 #define L2TP_TUNNEL_MAGIC 0x42114DDA
122 #define L2TP_SESSION_MAGIC 0x0C04EB7D
123
124 #define PPPOL2TP_HASH_BITS 4
125 #define PPPOL2TP_HASH_SIZE (1 << PPPOL2TP_HASH_BITS)
126
127 /* Default trace flags */
128 #define PPPOL2TP_DEFAULT_DEBUG_FLAGS 0
129
130 #define PRINTK(_mask, _type, _lvl, _fmt, args...) \
131 do { \
132 if ((_mask) & (_type)) \
133 printk(_lvl "PPPOL2TP: " _fmt, ##args); \
134 } while(0)
135
136 /* Number of bytes to build transmit L2TP headers.
137 * Unfortunately the size is different depending on whether sequence numbers
138 * are enabled.
139 */
140 #define PPPOL2TP_L2TP_HDR_SIZE_SEQ 10
141 #define PPPOL2TP_L2TP_HDR_SIZE_NOSEQ 6
142
143 struct pppol2tp_tunnel;
144
145 /* Describes a session. It is the sk_user_data field in the PPPoL2TP
146 * socket. Contains information to determine incoming packets and transmit
147 * outgoing ones.
148 */
149 struct pppol2tp_session
150 {
151 int magic; /* should be
152 * L2TP_SESSION_MAGIC */
153 int owner; /* pid that opened the socket */
154
155 struct sock *sock; /* Pointer to the session
156 * PPPoX socket */
157 struct sock *tunnel_sock; /* Pointer to the tunnel UDP
158 * socket */
159
160 struct pppol2tp_addr tunnel_addr; /* Description of tunnel */
161
162 struct pppol2tp_tunnel *tunnel; /* back pointer to tunnel
163 * context */
164
165 char name[20]; /* "sess xxxxx/yyyyy", where
166 * x=tunnel_id, y=session_id */
167 int mtu;
168 int mru;
169 int flags; /* accessed by PPPIOCGFLAGS.
170 * Unused. */
171 unsigned recv_seq:1; /* expect receive packets with
172 * sequence numbers? */
173 unsigned send_seq:1; /* send packets with sequence
174 * numbers? */
175 unsigned lns_mode:1; /* behave as LNS? LAC enables
176 * sequence numbers under
177 * control of LNS. */
178 int debug; /* bitmask of debug message
179 * categories */
180 int reorder_timeout; /* configured reorder timeout
181 * (in jiffies) */
182 u16 nr; /* session NR state (receive) */
183 u16 ns; /* session NR state (send) */
184 struct sk_buff_head reorder_q; /* receive reorder queue */
185 struct pppol2tp_ioc_stats stats;
186 struct hlist_node hlist; /* Hash list node */
187 };
188
189 /* The sk_user_data field of the tunnel's UDP socket. It contains info to track
190 * all the associated sessions so incoming packets can be sorted out
191 */
192 struct pppol2tp_tunnel
193 {
194 int magic; /* Should be L2TP_TUNNEL_MAGIC */
195 rwlock_t hlist_lock; /* protect session_hlist */
196 struct hlist_head session_hlist[PPPOL2TP_HASH_SIZE];
197 /* hashed list of sessions,
198 * hashed by id */
199 int debug; /* bitmask of debug message
200 * categories */
201 char name[12]; /* "tunl xxxxx" */
202 struct pppol2tp_ioc_stats stats;
203
204 void (*old_sk_destruct)(struct sock *);
205
206 struct sock *sock; /* Parent socket */
207 struct list_head list; /* Keep a list of all open
208 * prepared sockets */
209 struct net *pppol2tp_net; /* the net we belong to */
210
211 atomic_t ref_count;
212 };
213
214 /* Private data stored for received packets in the skb.
215 */
216 struct pppol2tp_skb_cb {
217 u16 ns;
218 u16 nr;
219 u16 has_seq;
220 u16 length;
221 unsigned long expires;
222 };
223
224 #define PPPOL2TP_SKB_CB(skb) ((struct pppol2tp_skb_cb *) &skb->cb[sizeof(struct inet_skb_parm)])
225
226 static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb);
227 static void pppol2tp_tunnel_free(struct pppol2tp_tunnel *tunnel);
228
229 static atomic_t pppol2tp_tunnel_count;
230 static atomic_t pppol2tp_session_count;
231 static struct ppp_channel_ops pppol2tp_chan_ops = { pppol2tp_xmit , NULL };
232 static const struct proto_ops pppol2tp_ops;
233
234 /* per-net private data for this module */
235 static int pppol2tp_net_id;
236 struct pppol2tp_net {
237 struct list_head pppol2tp_tunnel_list;
238 rwlock_t pppol2tp_tunnel_list_lock;
239 };
240
241 static inline struct pppol2tp_net *pppol2tp_pernet(struct net *net)
242 {
243 BUG_ON(!net);
244
245 return net_generic(net, pppol2tp_net_id);
246 }
247
248 /* Helpers to obtain tunnel/session contexts from sockets.
249 */
250 static inline struct pppol2tp_session *pppol2tp_sock_to_session(struct sock *sk)
251 {
252 struct pppol2tp_session *session;
253
254 if (sk == NULL)
255 return NULL;
256
257 sock_hold(sk);
258 session = (struct pppol2tp_session *)(sk->sk_user_data);
259 if (session == NULL) {
260 sock_put(sk);
261 goto out;
262 }
263
264 BUG_ON(session->magic != L2TP_SESSION_MAGIC);
265 out:
266 return session;
267 }
268
269 static inline struct pppol2tp_tunnel *pppol2tp_sock_to_tunnel(struct sock *sk)
270 {
271 struct pppol2tp_tunnel *tunnel;
272
273 if (sk == NULL)
274 return NULL;
275
276 sock_hold(sk);
277 tunnel = (struct pppol2tp_tunnel *)(sk->sk_user_data);
278 if (tunnel == NULL) {
279 sock_put(sk);
280 goto out;
281 }
282
283 BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);
284 out:
285 return tunnel;
286 }
287
288 /* Tunnel reference counts. Incremented per session that is added to
289 * the tunnel.
290 */
291 static inline void pppol2tp_tunnel_inc_refcount(struct pppol2tp_tunnel *tunnel)
292 {
293 atomic_inc(&tunnel->ref_count);
294 }
295
296 static inline void pppol2tp_tunnel_dec_refcount(struct pppol2tp_tunnel *tunnel)
297 {
298 if (atomic_dec_and_test(&tunnel->ref_count))
299 pppol2tp_tunnel_free(tunnel);
300 }
301
302 /* Session hash list.
303 * The session_id SHOULD be random according to RFC2661, but several
304 * L2TP implementations (Cisco and Microsoft) use incrementing
305 * session_ids. So we do a real hash on the session_id, rather than a
306 * simple bitmask.
307 */
308 static inline struct hlist_head *
309 pppol2tp_session_id_hash(struct pppol2tp_tunnel *tunnel, u16 session_id)
310 {
311 unsigned long hash_val = (unsigned long) session_id;
312 return &tunnel->session_hlist[hash_long(hash_val, PPPOL2TP_HASH_BITS)];
313 }
314
315 /* Lookup a session by id
316 */
317 static struct pppol2tp_session *
318 pppol2tp_session_find(struct pppol2tp_tunnel *tunnel, u16 session_id)
319 {
320 struct hlist_head *session_list =
321 pppol2tp_session_id_hash(tunnel, session_id);
322 struct pppol2tp_session *session;
323 struct hlist_node *walk;
324
325 read_lock_bh(&tunnel->hlist_lock);
326 hlist_for_each_entry(session, walk, session_list, hlist) {
327 if (session->tunnel_addr.s_session == session_id) {
328 read_unlock_bh(&tunnel->hlist_lock);
329 return session;
330 }
331 }
332 read_unlock_bh(&tunnel->hlist_lock);
333
334 return NULL;
335 }
336
337 /* Lookup a tunnel by id
338 */
339 static struct pppol2tp_tunnel *pppol2tp_tunnel_find(struct net *net, u16 tunnel_id)
340 {
341 struct pppol2tp_tunnel *tunnel;
342 struct pppol2tp_net *pn = pppol2tp_pernet(net);
343
344 read_lock_bh(&pn->pppol2tp_tunnel_list_lock);
345 list_for_each_entry(tunnel, &pn->pppol2tp_tunnel_list, list) {
346 if (tunnel->stats.tunnel_id == tunnel_id) {
347 read_unlock_bh(&pn->pppol2tp_tunnel_list_lock);
348 return tunnel;
349 }
350 }
351 read_unlock_bh(&pn->pppol2tp_tunnel_list_lock);
352
353 return NULL;
354 }
355
356 /*****************************************************************************
357 * Receive data handling
358 *****************************************************************************/
359
360 /* Queue a skb in order. We come here only if the skb has an L2TP sequence
361 * number.
362 */
363 static void pppol2tp_recv_queue_skb(struct pppol2tp_session *session, struct sk_buff *skb)
364 {
365 struct sk_buff *skbp;
366 struct sk_buff *tmp;
367 u16 ns = PPPOL2TP_SKB_CB(skb)->ns;
368
369 spin_lock_bh(&session->reorder_q.lock);
370 skb_queue_walk_safe(&session->reorder_q, skbp, tmp) {
371 if (PPPOL2TP_SKB_CB(skbp)->ns > ns) {
372 __skb_queue_before(&session->reorder_q, skbp, skb);
373 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
374 "%s: pkt %hu, inserted before %hu, reorder_q len=%d\n",
375 session->name, ns, PPPOL2TP_SKB_CB(skbp)->ns,
376 skb_queue_len(&session->reorder_q));
377 session->stats.rx_oos_packets++;
378 goto out;
379 }
380 }
381
382 __skb_queue_tail(&session->reorder_q, skb);
383
384 out:
385 spin_unlock_bh(&session->reorder_q.lock);
386 }
387
388 /* Dequeue a single skb.
389 */
390 static void pppol2tp_recv_dequeue_skb(struct pppol2tp_session *session, struct sk_buff *skb)
391 {
392 struct pppol2tp_tunnel *tunnel = session->tunnel;
393 int length = PPPOL2TP_SKB_CB(skb)->length;
394 struct sock *session_sock = NULL;
395
396 /* We're about to requeue the skb, so return resources
397 * to its current owner (a socket receive buffer).
398 */
399 skb_orphan(skb);
400
401 tunnel->stats.rx_packets++;
402 tunnel->stats.rx_bytes += length;
403 session->stats.rx_packets++;
404 session->stats.rx_bytes += length;
405
406 if (PPPOL2TP_SKB_CB(skb)->has_seq) {
407 /* Bump our Nr */
408 session->nr++;
409 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
410 "%s: updated nr to %hu\n", session->name, session->nr);
411 }
412
413 /* If the socket is bound, send it in to PPP's input queue. Otherwise
414 * queue it on the session socket.
415 */
416 session_sock = session->sock;
417 if (session_sock->sk_state & PPPOX_BOUND) {
418 struct pppox_sock *po;
419 PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
420 "%s: recv %d byte data frame, passing to ppp\n",
421 session->name, length);
422
423 /* We need to forget all info related to the L2TP packet
424 * gathered in the skb as we are going to reuse the same
425 * skb for the inner packet.
426 * Namely we need to:
427 * - reset xfrm (IPSec) information as it applies to
428 * the outer L2TP packet and not to the inner one
429 * - release the dst to force a route lookup on the inner
430 * IP packet since skb->dst currently points to the dst
431 * of the UDP tunnel
432 * - reset netfilter information as it doesn't apply
433 * to the inner packet either
434 */
435 secpath_reset(skb);
436 skb_dst_drop(skb);
437 nf_reset(skb);
438
439 po = pppox_sk(session_sock);
440 ppp_input(&po->chan, skb);
441 } else {
442 PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_INFO,
443 "%s: socket not bound\n", session->name);
444
445 /* Not bound. Nothing we can do, so discard. */
446 session->stats.rx_errors++;
447 kfree_skb(skb);
448 }
449
450 sock_put(session->sock);
451 }
452
453 /* Dequeue skbs from the session's reorder_q, subject to packet order.
454 * Skbs that have been in the queue for too long are simply discarded.
455 */
456 static void pppol2tp_recv_dequeue(struct pppol2tp_session *session)
457 {
458 struct sk_buff *skb;
459 struct sk_buff *tmp;
460
461 /* If the pkt at the head of the queue has the nr that we
462 * expect to send up next, dequeue it and any other
463 * in-sequence packets behind it.
464 */
465 spin_lock_bh(&session->reorder_q.lock);
466 skb_queue_walk_safe(&session->reorder_q, skb, tmp) {
467 if (time_after(jiffies, PPPOL2TP_SKB_CB(skb)->expires)) {
468 session->stats.rx_seq_discards++;
469 session->stats.rx_errors++;
470 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
471 "%s: oos pkt %hu len %d discarded (too old), "
472 "waiting for %hu, reorder_q_len=%d\n",
473 session->name, PPPOL2TP_SKB_CB(skb)->ns,
474 PPPOL2TP_SKB_CB(skb)->length, session->nr,
475 skb_queue_len(&session->reorder_q));
476 __skb_unlink(skb, &session->reorder_q);
477 kfree_skb(skb);
478 sock_put(session->sock);
479 continue;
480 }
481
482 if (PPPOL2TP_SKB_CB(skb)->has_seq) {
483 if (PPPOL2TP_SKB_CB(skb)->ns != session->nr) {
484 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
485 "%s: holding oos pkt %hu len %d, "
486 "waiting for %hu, reorder_q_len=%d\n",
487 session->name, PPPOL2TP_SKB_CB(skb)->ns,
488 PPPOL2TP_SKB_CB(skb)->length, session->nr,
489 skb_queue_len(&session->reorder_q));
490 goto out;
491 }
492 }
493 __skb_unlink(skb, &session->reorder_q);
494
495 /* Process the skb. We release the queue lock while we
496 * do so to let other contexts process the queue.
497 */
498 spin_unlock_bh(&session->reorder_q.lock);
499 pppol2tp_recv_dequeue_skb(session, skb);
500 spin_lock_bh(&session->reorder_q.lock);
501 }
502
503 out:
504 spin_unlock_bh(&session->reorder_q.lock);
505 }
506
507 static inline int pppol2tp_verify_udp_checksum(struct sock *sk,
508 struct sk_buff *skb)
509 {
510 struct udphdr *uh = udp_hdr(skb);
511 u16 ulen = ntohs(uh->len);
512 struct inet_sock *inet;
513 __wsum psum;
514
515 if (sk->sk_no_check || skb_csum_unnecessary(skb) || !uh->check)
516 return 0;
517
518 inet = inet_sk(sk);
519 psum = csum_tcpudp_nofold(inet->saddr, inet->daddr, ulen,
520 IPPROTO_UDP, 0);
521
522 if ((skb->ip_summed == CHECKSUM_COMPLETE) &&
523 !csum_fold(csum_add(psum, skb->csum)))
524 return 0;
525
526 skb->csum = psum;
527
528 return __skb_checksum_complete(skb);
529 }
530
531 /* Internal receive frame. Do the real work of receiving an L2TP data frame
532 * here. The skb is not on a list when we get here.
533 * Returns 0 if the packet was a data packet and was successfully passed on.
534 * Returns 1 if the packet was not a good data packet and could not be
535 * forwarded. All such packets are passed up to userspace to deal with.
536 */
537 static int pppol2tp_recv_core(struct sock *sock, struct sk_buff *skb)
538 {
539 struct pppol2tp_session *session = NULL;
540 struct pppol2tp_tunnel *tunnel;
541 unsigned char *ptr, *optr;
542 u16 hdrflags;
543 u16 tunnel_id, session_id;
544 int length;
545 int offset;
546
547 tunnel = pppol2tp_sock_to_tunnel(sock);
548 if (tunnel == NULL)
549 goto no_tunnel;
550
551 if (tunnel->sock && pppol2tp_verify_udp_checksum(tunnel->sock, skb))
552 goto discard_bad_csum;
553
554 /* UDP always verifies the packet length. */
555 __skb_pull(skb, sizeof(struct udphdr));
556
557 /* Short packet? */
558 if (!pskb_may_pull(skb, 12)) {
559 PRINTK(tunnel->debug, PPPOL2TP_MSG_DATA, KERN_INFO,
560 "%s: recv short packet (len=%d)\n", tunnel->name, skb->len);
561 goto error;
562 }
563
564 /* Point to L2TP header */
565 optr = ptr = skb->data;
566
567 /* Get L2TP header flags */
568 hdrflags = ntohs(*(__be16*)ptr);
569
570 /* Trace packet contents, if enabled */
571 if (tunnel->debug & PPPOL2TP_MSG_DATA) {
572 length = min(16u, skb->len);
573 if (!pskb_may_pull(skb, length))
574 goto error;
575
576 printk(KERN_DEBUG "%s: recv: ", tunnel->name);
577
578 offset = 0;
579 do {
580 printk(" %02X", ptr[offset]);
581 } while (++offset < length);
582
583 printk("\n");
584 }
585
586 /* Get length of L2TP packet */
587 length = skb->len;
588
589 /* If type is control packet, it is handled by userspace. */
590 if (hdrflags & L2TP_HDRFLAG_T) {
591 PRINTK(tunnel->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
592 "%s: recv control packet, len=%d\n", tunnel->name, length);
593 goto error;
594 }
595
596 /* Skip flags */
597 ptr += 2;
598
599 /* If length is present, skip it */
600 if (hdrflags & L2TP_HDRFLAG_L)
601 ptr += 2;
602
603 /* Extract tunnel and session ID */
604 tunnel_id = ntohs(*(__be16 *) ptr);
605 ptr += 2;
606 session_id = ntohs(*(__be16 *) ptr);
607 ptr += 2;
608
609 /* Find the session context */
610 session = pppol2tp_session_find(tunnel, session_id);
611 if (!session) {
612 /* Not found? Pass to userspace to deal with */
613 PRINTK(tunnel->debug, PPPOL2TP_MSG_DATA, KERN_INFO,
614 "%s: no socket found (%hu/%hu). Passing up.\n",
615 tunnel->name, tunnel_id, session_id);
616 goto error;
617 }
618 sock_hold(session->sock);
619
620 /* The ref count on the socket was increased by the above call since
621 * we now hold a pointer to the session. Take care to do sock_put()
622 * when exiting this function from now on...
623 */
624
625 /* Handle the optional sequence numbers. If we are the LAC,
626 * enable/disable sequence numbers under the control of the LNS. If
627 * no sequence numbers present but we were expecting them, discard
628 * frame.
629 */
630 if (hdrflags & L2TP_HDRFLAG_S) {
631 u16 ns, nr;
632 ns = ntohs(*(__be16 *) ptr);
633 ptr += 2;
634 nr = ntohs(*(__be16 *) ptr);
635 ptr += 2;
636
637 /* Received a packet with sequence numbers. If we're the LNS,
638 * check if we sre sending sequence numbers and if not,
639 * configure it so.
640 */
641 if ((!session->lns_mode) && (!session->send_seq)) {
642 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_INFO,
643 "%s: requested to enable seq numbers by LNS\n",
644 session->name);
645 session->send_seq = -1;
646 }
647
648 /* Store L2TP info in the skb */
649 PPPOL2TP_SKB_CB(skb)->ns = ns;
650 PPPOL2TP_SKB_CB(skb)->nr = nr;
651 PPPOL2TP_SKB_CB(skb)->has_seq = 1;
652
653 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
654 "%s: recv data ns=%hu, nr=%hu, session nr=%hu\n",
655 session->name, ns, nr, session->nr);
656 } else {
657 /* No sequence numbers.
658 * If user has configured mandatory sequence numbers, discard.
659 */
660 if (session->recv_seq) {
661 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_WARNING,
662 "%s: recv data has no seq numbers when required. "
663 "Discarding\n", session->name);
664 session->stats.rx_seq_discards++;
665 goto discard;
666 }
667
668 /* If we're the LAC and we're sending sequence numbers, the
669 * LNS has requested that we no longer send sequence numbers.
670 * If we're the LNS and we're sending sequence numbers, the
671 * LAC is broken. Discard the frame.
672 */
673 if ((!session->lns_mode) && (session->send_seq)) {
674 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_INFO,
675 "%s: requested to disable seq numbers by LNS\n",
676 session->name);
677 session->send_seq = 0;
678 } else if (session->send_seq) {
679 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_WARNING,
680 "%s: recv data has no seq numbers when required. "
681 "Discarding\n", session->name);
682 session->stats.rx_seq_discards++;
683 goto discard;
684 }
685
686 /* Store L2TP info in the skb */
687 PPPOL2TP_SKB_CB(skb)->has_seq = 0;
688 }
689
690 /* If offset bit set, skip it. */
691 if (hdrflags & L2TP_HDRFLAG_O) {
692 offset = ntohs(*(__be16 *)ptr);
693 ptr += 2 + offset;
694 }
695
696 offset = ptr - optr;
697 if (!pskb_may_pull(skb, offset))
698 goto discard;
699
700 __skb_pull(skb, offset);
701
702 /* Skip PPP header, if present. In testing, Microsoft L2TP clients
703 * don't send the PPP header (PPP header compression enabled), but
704 * other clients can include the header. So we cope with both cases
705 * here. The PPP header is always FF03 when using L2TP.
706 *
707 * Note that skb->data[] isn't dereferenced from a u16 ptr here since
708 * the field may be unaligned.
709 */
710 if (!pskb_may_pull(skb, 2))
711 goto discard;
712
713 if ((skb->data[0] == 0xff) && (skb->data[1] == 0x03))
714 skb_pull(skb, 2);
715
716 /* Prepare skb for adding to the session's reorder_q. Hold
717 * packets for max reorder_timeout or 1 second if not
718 * reordering.
719 */
720 PPPOL2TP_SKB_CB(skb)->length = length;
721 PPPOL2TP_SKB_CB(skb)->expires = jiffies +
722 (session->reorder_timeout ? session->reorder_timeout : HZ);
723
724 /* Add packet to the session's receive queue. Reordering is done here, if
725 * enabled. Saved L2TP protocol info is stored in skb->sb[].
726 */
727 if (PPPOL2TP_SKB_CB(skb)->has_seq) {
728 if (session->reorder_timeout != 0) {
729 /* Packet reordering enabled. Add skb to session's
730 * reorder queue, in order of ns.
731 */
732 pppol2tp_recv_queue_skb(session, skb);
733 } else {
734 /* Packet reordering disabled. Discard out-of-sequence
735 * packets
736 */
737 if (PPPOL2TP_SKB_CB(skb)->ns != session->nr) {
738 session->stats.rx_seq_discards++;
739 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
740 "%s: oos pkt %hu len %d discarded, "
741 "waiting for %hu, reorder_q_len=%d\n",
742 session->name, PPPOL2TP_SKB_CB(skb)->ns,
743 PPPOL2TP_SKB_CB(skb)->length, session->nr,
744 skb_queue_len(&session->reorder_q));
745 goto discard;
746 }
747 skb_queue_tail(&session->reorder_q, skb);
748 }
749 } else {
750 /* No sequence numbers. Add the skb to the tail of the
751 * reorder queue. This ensures that it will be
752 * delivered after all previous sequenced skbs.
753 */
754 skb_queue_tail(&session->reorder_q, skb);
755 }
756
757 /* Try to dequeue as many skbs from reorder_q as we can. */
758 pppol2tp_recv_dequeue(session);
759 sock_put(sock);
760
761 return 0;
762
763 discard:
764 session->stats.rx_errors++;
765 kfree_skb(skb);
766 sock_put(session->sock);
767 sock_put(sock);
768
769 return 0;
770
771 discard_bad_csum:
772 LIMIT_NETDEBUG("%s: UDP: bad checksum\n", tunnel->name);
773 UDP_INC_STATS_USER(&init_net, UDP_MIB_INERRORS, 0);
774 tunnel->stats.rx_errors++;
775 kfree_skb(skb);
776 sock_put(sock);
777
778 return 0;
779
780 error:
781 /* Put UDP header back */
782 __skb_push(skb, sizeof(struct udphdr));
783 sock_put(sock);
784
785 no_tunnel:
786 return 1;
787 }
788
789 /* UDP encapsulation receive handler. See net/ipv4/udp.c.
790 * Return codes:
791 * 0 : success.
792 * <0: error
793 * >0: skb should be passed up to userspace as UDP.
794 */
795 static int pppol2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
796 {
797 struct pppol2tp_tunnel *tunnel;
798
799 tunnel = pppol2tp_sock_to_tunnel(sk);
800 if (tunnel == NULL)
801 goto pass_up;
802
803 PRINTK(tunnel->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
804 "%s: received %d bytes\n", tunnel->name, skb->len);
805
806 if (pppol2tp_recv_core(sk, skb))
807 goto pass_up_put;
808
809 sock_put(sk);
810 return 0;
811
812 pass_up_put:
813 sock_put(sk);
814 pass_up:
815 return 1;
816 }
817
818 /* Receive message. This is the recvmsg for the PPPoL2TP socket.
819 */
820 static int pppol2tp_recvmsg(struct kiocb *iocb, struct socket *sock,
821 struct msghdr *msg, size_t len,
822 int flags)
823 {
824 int err;
825 struct sk_buff *skb;
826 struct sock *sk = sock->sk;
827
828 err = -EIO;
829 if (sk->sk_state & PPPOX_BOUND)
830 goto end;
831
832 msg->msg_namelen = 0;
833
834 err = 0;
835 skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
836 flags & MSG_DONTWAIT, &err);
837 if (!skb)
838 goto end;
839
840 if (len > skb->len)
841 len = skb->len;
842 else if (len < skb->len)
843 msg->msg_flags |= MSG_TRUNC;
844
845 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len);
846 if (likely(err == 0))
847 err = len;
848
849 kfree_skb(skb);
850 end:
851 return err;
852 }
853
854 /************************************************************************
855 * Transmit handling
856 ***********************************************************************/
857
858 /* Tell how big L2TP headers are for a particular session. This
859 * depends on whether sequence numbers are being used.
860 */
861 static inline int pppol2tp_l2tp_header_len(struct pppol2tp_session *session)
862 {
863 if (session->send_seq)
864 return PPPOL2TP_L2TP_HDR_SIZE_SEQ;
865
866 return PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
867 }
868
869 /* Build an L2TP header for the session into the buffer provided.
870 */
871 static void pppol2tp_build_l2tp_header(struct pppol2tp_session *session,
872 void *buf)
873 {
874 __be16 *bufp = buf;
875 u16 flags = L2TP_HDR_VER;
876
877 if (session->send_seq)
878 flags |= L2TP_HDRFLAG_S;
879
880 /* Setup L2TP header.
881 * FIXME: Can this ever be unaligned? Is direct dereferencing of
882 * 16-bit header fields safe here for all architectures?
883 */
884 *bufp++ = htons(flags);
885 *bufp++ = htons(session->tunnel_addr.d_tunnel);
886 *bufp++ = htons(session->tunnel_addr.d_session);
887 if (session->send_seq) {
888 *bufp++ = htons(session->ns);
889 *bufp++ = 0;
890 session->ns++;
891 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
892 "%s: updated ns to %hu\n", session->name, session->ns);
893 }
894 }
895
896 /* This is the sendmsg for the PPPoL2TP pppol2tp_session socket. We come here
897 * when a user application does a sendmsg() on the session socket. L2TP and
898 * PPP headers must be inserted into the user's data.
899 */
900 static int pppol2tp_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
901 size_t total_len)
902 {
903 static const unsigned char ppph[2] = { 0xff, 0x03 };
904 struct sock *sk = sock->sk;
905 struct inet_sock *inet;
906 __wsum csum;
907 struct sk_buff *skb;
908 int error;
909 int hdr_len;
910 struct pppol2tp_session *session;
911 struct pppol2tp_tunnel *tunnel;
912 struct udphdr *uh;
913 unsigned int len;
914 struct sock *sk_tun;
915 u16 udp_len;
916
917 error = -ENOTCONN;
918 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
919 goto error;
920
921 /* Get session and tunnel contexts */
922 error = -EBADF;
923 session = pppol2tp_sock_to_session(sk);
924 if (session == NULL)
925 goto error;
926
927 sk_tun = session->tunnel_sock;
928 tunnel = pppol2tp_sock_to_tunnel(sk_tun);
929 if (tunnel == NULL)
930 goto error_put_sess;
931
932 /* What header length is configured for this session? */
933 hdr_len = pppol2tp_l2tp_header_len(session);
934
935 /* Allocate a socket buffer */
936 error = -ENOMEM;
937 skb = sock_wmalloc(sk, NET_SKB_PAD + sizeof(struct iphdr) +
938 sizeof(struct udphdr) + hdr_len +
939 sizeof(ppph) + total_len,
940 0, GFP_KERNEL);
941 if (!skb)
942 goto error_put_sess_tun;
943
944 /* Reserve space for headers. */
945 skb_reserve(skb, NET_SKB_PAD);
946 skb_reset_network_header(skb);
947 skb_reserve(skb, sizeof(struct iphdr));
948 skb_reset_transport_header(skb);
949
950 /* Build UDP header */
951 inet = inet_sk(sk_tun);
952 udp_len = hdr_len + sizeof(ppph) + total_len;
953 uh = (struct udphdr *) skb->data;
954 uh->source = inet->sport;
955 uh->dest = inet->dport;
956 uh->len = htons(udp_len);
957 uh->check = 0;
958 skb_put(skb, sizeof(struct udphdr));
959
960 /* Build L2TP header */
961 pppol2tp_build_l2tp_header(session, skb->data);
962 skb_put(skb, hdr_len);
963
964 /* Add PPP header */
965 skb->data[0] = ppph[0];
966 skb->data[1] = ppph[1];
967 skb_put(skb, 2);
968
969 /* Copy user data into skb */
970 error = memcpy_fromiovec(skb->data, m->msg_iov, total_len);
971 if (error < 0) {
972 kfree_skb(skb);
973 goto error_put_sess_tun;
974 }
975 skb_put(skb, total_len);
976
977 /* Calculate UDP checksum if configured to do so */
978 if (sk_tun->sk_no_check == UDP_CSUM_NOXMIT)
979 skb->ip_summed = CHECKSUM_NONE;
980 else if (!(skb_dst(skb)->dev->features & NETIF_F_V4_CSUM)) {
981 skb->ip_summed = CHECKSUM_COMPLETE;
982 csum = skb_checksum(skb, 0, udp_len, 0);
983 uh->check = csum_tcpudp_magic(inet->saddr, inet->daddr,
984 udp_len, IPPROTO_UDP, csum);
985 if (uh->check == 0)
986 uh->check = CSUM_MANGLED_0;
987 } else {
988 skb->ip_summed = CHECKSUM_PARTIAL;
989 skb->csum_start = skb_transport_header(skb) - skb->head;
990 skb->csum_offset = offsetof(struct udphdr, check);
991 uh->check = ~csum_tcpudp_magic(inet->saddr, inet->daddr,
992 udp_len, IPPROTO_UDP, 0);
993 }
994
995 /* Debug */
996 if (session->send_seq)
997 PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
998 "%s: send %Zd bytes, ns=%hu\n", session->name,
999 total_len, session->ns - 1);
1000 else
1001 PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
1002 "%s: send %Zd bytes\n", session->name, total_len);
1003
1004 if (session->debug & PPPOL2TP_MSG_DATA) {
1005 int i;
1006 unsigned char *datap = skb->data;
1007
1008 printk(KERN_DEBUG "%s: xmit:", session->name);
1009 for (i = 0; i < total_len; i++) {
1010 printk(" %02X", *datap++);
1011 if (i == 15) {
1012 printk(" ...");
1013 break;
1014 }
1015 }
1016 printk("\n");
1017 }
1018
1019 /* Queue the packet to IP for output */
1020 len = skb->len;
1021 error = ip_queue_xmit(skb, 1);
1022
1023 /* Update stats */
1024 if (error >= 0) {
1025 tunnel->stats.tx_packets++;
1026 tunnel->stats.tx_bytes += len;
1027 session->stats.tx_packets++;
1028 session->stats.tx_bytes += len;
1029 } else {
1030 tunnel->stats.tx_errors++;
1031 session->stats.tx_errors++;
1032 }
1033
1034 return error;
1035
1036 error_put_sess_tun:
1037 sock_put(session->tunnel_sock);
1038 error_put_sess:
1039 sock_put(sk);
1040 error:
1041 return error;
1042 }
1043
1044 /* Automatically called when the skb is freed.
1045 */
1046 static void pppol2tp_sock_wfree(struct sk_buff *skb)
1047 {
1048 sock_put(skb->sk);
1049 }
1050
1051 /* For data skbs that we transmit, we associate with the tunnel socket
1052 * but don't do accounting.
1053 */
1054 static inline void pppol2tp_skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
1055 {
1056 sock_hold(sk);
1057 skb->sk = sk;
1058 skb->destructor = pppol2tp_sock_wfree;
1059 }
1060
1061 /* Transmit function called by generic PPP driver. Sends PPP frame
1062 * over PPPoL2TP socket.
1063 *
1064 * This is almost the same as pppol2tp_sendmsg(), but rather than
1065 * being called with a msghdr from userspace, it is called with a skb
1066 * from the kernel.
1067 *
1068 * The supplied skb from ppp doesn't have enough headroom for the
1069 * insertion of L2TP, UDP and IP headers so we need to allocate more
1070 * headroom in the skb. This will create a cloned skb. But we must be
1071 * careful in the error case because the caller will expect to free
1072 * the skb it supplied, not our cloned skb. So we take care to always
1073 * leave the original skb unfreed if we return an error.
1074 */
1075 static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
1076 {
1077 static const u8 ppph[2] = { 0xff, 0x03 };
1078 struct sock *sk = (struct sock *) chan->private;
1079 struct sock *sk_tun;
1080 int hdr_len;
1081 u16 udp_len;
1082 struct pppol2tp_session *session;
1083 struct pppol2tp_tunnel *tunnel;
1084 int rc;
1085 int headroom;
1086 int data_len = skb->len;
1087 struct inet_sock *inet;
1088 __wsum csum;
1089 struct udphdr *uh;
1090 unsigned int len;
1091 int old_headroom;
1092 int new_headroom;
1093
1094 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
1095 goto abort;
1096
1097 /* Get session and tunnel contexts from the socket */
1098 session = pppol2tp_sock_to_session(sk);
1099 if (session == NULL)
1100 goto abort;
1101
1102 sk_tun = session->tunnel_sock;
1103 if (sk_tun == NULL)
1104 goto abort_put_sess;
1105 tunnel = pppol2tp_sock_to_tunnel(sk_tun);
1106 if (tunnel == NULL)
1107 goto abort_put_sess;
1108
1109 /* What header length is configured for this session? */
1110 hdr_len = pppol2tp_l2tp_header_len(session);
1111
1112 /* Check that there's enough headroom in the skb to insert IP,
1113 * UDP and L2TP and PPP headers. If not enough, expand it to
1114 * make room. Adjust truesize.
1115 */
1116 headroom = NET_SKB_PAD + sizeof(struct iphdr) +
1117 sizeof(struct udphdr) + hdr_len + sizeof(ppph);
1118 old_headroom = skb_headroom(skb);
1119 if (skb_cow_head(skb, headroom))
1120 goto abort_put_sess_tun;
1121
1122 new_headroom = skb_headroom(skb);
1123 skb_orphan(skb);
1124 skb->truesize += new_headroom - old_headroom;
1125
1126 /* Setup PPP header */
1127 __skb_push(skb, sizeof(ppph));
1128 skb->data[0] = ppph[0];
1129 skb->data[1] = ppph[1];
1130
1131 /* Setup L2TP header */
1132 pppol2tp_build_l2tp_header(session, __skb_push(skb, hdr_len));
1133
1134 udp_len = sizeof(struct udphdr) + hdr_len + sizeof(ppph) + data_len;
1135
1136 /* Setup UDP header */
1137 inet = inet_sk(sk_tun);
1138 __skb_push(skb, sizeof(*uh));
1139 skb_reset_transport_header(skb);
1140 uh = udp_hdr(skb);
1141 uh->source = inet->sport;
1142 uh->dest = inet->dport;
1143 uh->len = htons(udp_len);
1144 uh->check = 0;
1145
1146 /* Debug */
1147 if (session->send_seq)
1148 PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
1149 "%s: send %d bytes, ns=%hu\n", session->name,
1150 data_len, session->ns - 1);
1151 else
1152 PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
1153 "%s: send %d bytes\n", session->name, data_len);
1154
1155 if (session->debug & PPPOL2TP_MSG_DATA) {
1156 int i;
1157 unsigned char *datap = skb->data;
1158
1159 printk(KERN_DEBUG "%s: xmit:", session->name);
1160 for (i = 0; i < data_len; i++) {
1161 printk(" %02X", *datap++);
1162 if (i == 31) {
1163 printk(" ...");
1164 break;
1165 }
1166 }
1167 printk("\n");
1168 }
1169
1170 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1171 IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED |
1172 IPSKB_REROUTED);
1173 nf_reset(skb);
1174
1175 /* Get routing info from the tunnel socket */
1176 skb_dst_drop(skb);
1177 skb_dst_set(skb, dst_clone(__sk_dst_get(sk_tun)));
1178 pppol2tp_skb_set_owner_w(skb, sk_tun);
1179
1180 /* Calculate UDP checksum if configured to do so */
1181 if (sk_tun->sk_no_check == UDP_CSUM_NOXMIT)
1182 skb->ip_summed = CHECKSUM_NONE;
1183 else if ((skb_dst(skb) && skb_dst(skb)->dev) &&
1184 (!(skb_dst(skb)->dev->features & NETIF_F_V4_CSUM))) {
1185 skb->ip_summed = CHECKSUM_COMPLETE;
1186 csum = skb_checksum(skb, 0, udp_len, 0);
1187 uh->check = csum_tcpudp_magic(inet->saddr, inet->daddr,
1188 udp_len, IPPROTO_UDP, csum);
1189 if (uh->check == 0)
1190 uh->check = CSUM_MANGLED_0;
1191 } else {
1192 skb->ip_summed = CHECKSUM_PARTIAL;
1193 skb->csum_start = skb_transport_header(skb) - skb->head;
1194 skb->csum_offset = offsetof(struct udphdr, check);
1195 uh->check = ~csum_tcpudp_magic(inet->saddr, inet->daddr,
1196 udp_len, IPPROTO_UDP, 0);
1197 }
1198
1199 /* Queue the packet to IP for output */
1200 len = skb->len;
1201 rc = ip_queue_xmit(skb, 1);
1202
1203 /* Update stats */
1204 if (rc >= 0) {
1205 tunnel->stats.tx_packets++;
1206 tunnel->stats.tx_bytes += len;
1207 session->stats.tx_packets++;
1208 session->stats.tx_bytes += len;
1209 } else {
1210 tunnel->stats.tx_errors++;
1211 session->stats.tx_errors++;
1212 }
1213
1214 sock_put(sk_tun);
1215 sock_put(sk);
1216 return 1;
1217
1218 abort_put_sess_tun:
1219 sock_put(sk_tun);
1220 abort_put_sess:
1221 sock_put(sk);
1222 abort:
1223 /* Free the original skb */
1224 kfree_skb(skb);
1225 return 1;
1226 }
1227
1228 /*****************************************************************************
1229 * Session (and tunnel control) socket create/destroy.
1230 *****************************************************************************/
1231
1232 /* When the tunnel UDP socket is closed, all the attached sockets need to go
1233 * too.
1234 */
1235 static void pppol2tp_tunnel_closeall(struct pppol2tp_tunnel *tunnel)
1236 {
1237 int hash;
1238 struct hlist_node *walk;
1239 struct hlist_node *tmp;
1240 struct pppol2tp_session *session;
1241 struct sock *sk;
1242
1243 BUG_ON(tunnel == NULL);
1244
1245 PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1246 "%s: closing all sessions...\n", tunnel->name);
1247
1248 write_lock_bh(&tunnel->hlist_lock);
1249 for (hash = 0; hash < PPPOL2TP_HASH_SIZE; hash++) {
1250 again:
1251 hlist_for_each_safe(walk, tmp, &tunnel->session_hlist[hash]) {
1252 struct sk_buff *skb;
1253
1254 session = hlist_entry(walk, struct pppol2tp_session, hlist);
1255
1256 sk = session->sock;
1257
1258 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1259 "%s: closing session\n", session->name);
1260
1261 hlist_del_init(&session->hlist);
1262
1263 /* Since we should hold the sock lock while
1264 * doing any unbinding, we need to release the
1265 * lock we're holding before taking that lock.
1266 * Hold a reference to the sock so it doesn't
1267 * disappear as we're jumping between locks.
1268 */
1269 sock_hold(sk);
1270 write_unlock_bh(&tunnel->hlist_lock);
1271 lock_sock(sk);
1272
1273 if (sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND)) {
1274 pppox_unbind_sock(sk);
1275 sk->sk_state = PPPOX_DEAD;
1276 sk->sk_state_change(sk);
1277 }
1278
1279 /* Purge any queued data */
1280 skb_queue_purge(&sk->sk_receive_queue);
1281 skb_queue_purge(&sk->sk_write_queue);
1282 while ((skb = skb_dequeue(&session->reorder_q))) {
1283 kfree_skb(skb);
1284 sock_put(sk);
1285 }
1286
1287 release_sock(sk);
1288 sock_put(sk);
1289
1290 /* Now restart from the beginning of this hash
1291 * chain. We always remove a session from the
1292 * list so we are guaranteed to make forward
1293 * progress.
1294 */
1295 write_lock_bh(&tunnel->hlist_lock);
1296 goto again;
1297 }
1298 }
1299 write_unlock_bh(&tunnel->hlist_lock);
1300 }
1301
1302 /* Really kill the tunnel.
1303 * Come here only when all sessions have been cleared from the tunnel.
1304 */
1305 static void pppol2tp_tunnel_free(struct pppol2tp_tunnel *tunnel)
1306 {
1307 struct pppol2tp_net *pn = pppol2tp_pernet(tunnel->pppol2tp_net);
1308
1309 /* Remove from socket list */
1310 write_lock_bh(&pn->pppol2tp_tunnel_list_lock);
1311 list_del_init(&tunnel->list);
1312 write_unlock_bh(&pn->pppol2tp_tunnel_list_lock);
1313
1314 atomic_dec(&pppol2tp_tunnel_count);
1315 kfree(tunnel);
1316 }
1317
1318 /* Tunnel UDP socket destruct hook.
1319 * The tunnel context is deleted only when all session sockets have been
1320 * closed.
1321 */
1322 static void pppol2tp_tunnel_destruct(struct sock *sk)
1323 {
1324 struct pppol2tp_tunnel *tunnel;
1325
1326 tunnel = sk->sk_user_data;
1327 if (tunnel == NULL)
1328 goto end;
1329
1330 PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1331 "%s: closing...\n", tunnel->name);
1332
1333 /* Close all sessions */
1334 pppol2tp_tunnel_closeall(tunnel);
1335
1336 /* No longer an encapsulation socket. See net/ipv4/udp.c */
1337 (udp_sk(sk))->encap_type = 0;
1338 (udp_sk(sk))->encap_rcv = NULL;
1339
1340 /* Remove hooks into tunnel socket */
1341 tunnel->sock = NULL;
1342 sk->sk_destruct = tunnel->old_sk_destruct;
1343 sk->sk_user_data = NULL;
1344
1345 /* Call original (UDP) socket descructor */
1346 if (sk->sk_destruct != NULL)
1347 (*sk->sk_destruct)(sk);
1348
1349 pppol2tp_tunnel_dec_refcount(tunnel);
1350
1351 end:
1352 return;
1353 }
1354
1355 /* Really kill the session socket. (Called from sock_put() if
1356 * refcnt == 0.)
1357 */
1358 static void pppol2tp_session_destruct(struct sock *sk)
1359 {
1360 struct pppol2tp_session *session = NULL;
1361
1362 if (sk->sk_user_data != NULL) {
1363 struct pppol2tp_tunnel *tunnel;
1364
1365 session = sk->sk_user_data;
1366 if (session == NULL)
1367 goto out;
1368
1369 BUG_ON(session->magic != L2TP_SESSION_MAGIC);
1370
1371 /* Don't use pppol2tp_sock_to_tunnel() here to
1372 * get the tunnel context because the tunnel
1373 * socket might have already been closed (its
1374 * sk->sk_user_data will be NULL) so use the
1375 * session's private tunnel ptr instead.
1376 */
1377 tunnel = session->tunnel;
1378 if (tunnel != NULL) {
1379 BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);
1380
1381 /* If session_id is zero, this is a null
1382 * session context, which was created for a
1383 * socket that is being used only to manage
1384 * tunnels.
1385 */
1386 if (session->tunnel_addr.s_session != 0) {
1387 /* Delete the session socket from the
1388 * hash
1389 */
1390 write_lock_bh(&tunnel->hlist_lock);
1391 hlist_del_init(&session->hlist);
1392 write_unlock_bh(&tunnel->hlist_lock);
1393
1394 atomic_dec(&pppol2tp_session_count);
1395 }
1396
1397 /* This will delete the tunnel context if this
1398 * is the last session on the tunnel.
1399 */
1400 session->tunnel = NULL;
1401 session->tunnel_sock = NULL;
1402 pppol2tp_tunnel_dec_refcount(tunnel);
1403 }
1404 }
1405
1406 kfree(session);
1407 out:
1408 return;
1409 }
1410
1411 /* Called when the PPPoX socket (session) is closed.
1412 */
1413 static int pppol2tp_release(struct socket *sock)
1414 {
1415 struct sock *sk = sock->sk;
1416 struct pppol2tp_session *session;
1417 int error;
1418
1419 if (!sk)
1420 return 0;
1421
1422 error = -EBADF;
1423 lock_sock(sk);
1424 if (sock_flag(sk, SOCK_DEAD) != 0)
1425 goto error;
1426
1427 pppox_unbind_sock(sk);
1428
1429 /* Signal the death of the socket. */
1430 sk->sk_state = PPPOX_DEAD;
1431 sock_orphan(sk);
1432 sock->sk = NULL;
1433
1434 session = pppol2tp_sock_to_session(sk);
1435
1436 /* Purge any queued data */
1437 skb_queue_purge(&sk->sk_receive_queue);
1438 skb_queue_purge(&sk->sk_write_queue);
1439 if (session != NULL) {
1440 struct sk_buff *skb;
1441 while ((skb = skb_dequeue(&session->reorder_q))) {
1442 kfree_skb(skb);
1443 sock_put(sk);
1444 }
1445 sock_put(sk);
1446 }
1447
1448 release_sock(sk);
1449
1450 /* This will delete the session context via
1451 * pppol2tp_session_destruct() if the socket's refcnt drops to
1452 * zero.
1453 */
1454 sock_put(sk);
1455
1456 return 0;
1457
1458 error:
1459 release_sock(sk);
1460 return error;
1461 }
1462
1463 /* Internal function to prepare a tunnel (UDP) socket to have PPPoX
1464 * sockets attached to it.
1465 */
1466 static struct sock *pppol2tp_prepare_tunnel_socket(struct net *net,
1467 int fd, u16 tunnel_id, int *error)
1468 {
1469 int err;
1470 struct socket *sock = NULL;
1471 struct sock *sk;
1472 struct pppol2tp_tunnel *tunnel;
1473 struct pppol2tp_net *pn;
1474 struct sock *ret = NULL;
1475
1476 /* Get the tunnel UDP socket from the fd, which was opened by
1477 * the userspace L2TP daemon.
1478 */
1479 err = -EBADF;
1480 sock = sockfd_lookup(fd, &err);
1481 if (!sock) {
1482 PRINTK(-1, PPPOL2TP_MSG_CONTROL, KERN_ERR,
1483 "tunl %hu: sockfd_lookup(fd=%d) returned %d\n",
1484 tunnel_id, fd, err);
1485 goto err;
1486 }
1487
1488 sk = sock->sk;
1489
1490 /* Quick sanity checks */
1491 err = -EPROTONOSUPPORT;
1492 if (sk->sk_protocol != IPPROTO_UDP) {
1493 PRINTK(-1, PPPOL2TP_MSG_CONTROL, KERN_ERR,
1494 "tunl %hu: fd %d wrong protocol, got %d, expected %d\n",
1495 tunnel_id, fd, sk->sk_protocol, IPPROTO_UDP);
1496 goto err;
1497 }
1498 err = -EAFNOSUPPORT;
1499 if (sock->ops->family != AF_INET) {
1500 PRINTK(-1, PPPOL2TP_MSG_CONTROL, KERN_ERR,
1501 "tunl %hu: fd %d wrong family, got %d, expected %d\n",
1502 tunnel_id, fd, sock->ops->family, AF_INET);
1503 goto err;
1504 }
1505
1506 err = -ENOTCONN;
1507
1508 /* Check if this socket has already been prepped */
1509 tunnel = (struct pppol2tp_tunnel *)sk->sk_user_data;
1510 if (tunnel != NULL) {
1511 /* User-data field already set */
1512 err = -EBUSY;
1513 BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);
1514
1515 /* This socket has already been prepped */
1516 ret = tunnel->sock;
1517 goto out;
1518 }
1519
1520 /* This socket is available and needs prepping. Create a new tunnel
1521 * context and init it.
1522 */
1523 sk->sk_user_data = tunnel = kzalloc(sizeof(struct pppol2tp_tunnel), GFP_KERNEL);
1524 if (sk->sk_user_data == NULL) {
1525 err = -ENOMEM;
1526 goto err;
1527 }
1528
1529 tunnel->magic = L2TP_TUNNEL_MAGIC;
1530 sprintf(&tunnel->name[0], "tunl %hu", tunnel_id);
1531
1532 tunnel->stats.tunnel_id = tunnel_id;
1533 tunnel->debug = PPPOL2TP_DEFAULT_DEBUG_FLAGS;
1534
1535 /* Hook on the tunnel socket destructor so that we can cleanup
1536 * if the tunnel socket goes away.
1537 */
1538 tunnel->old_sk_destruct = sk->sk_destruct;
1539 sk->sk_destruct = &pppol2tp_tunnel_destruct;
1540
1541 tunnel->sock = sk;
1542 sk->sk_allocation = GFP_ATOMIC;
1543
1544 /* Misc init */
1545 rwlock_init(&tunnel->hlist_lock);
1546
1547 /* The net we belong to */
1548 tunnel->pppol2tp_net = net;
1549 pn = pppol2tp_pernet(net);
1550
1551 /* Add tunnel to our list */
1552 INIT_LIST_HEAD(&tunnel->list);
1553 write_lock_bh(&pn->pppol2tp_tunnel_list_lock);
1554 list_add(&tunnel->list, &pn->pppol2tp_tunnel_list);
1555 write_unlock_bh(&pn->pppol2tp_tunnel_list_lock);
1556 atomic_inc(&pppol2tp_tunnel_count);
1557
1558 /* Bump the reference count. The tunnel context is deleted
1559 * only when this drops to zero.
1560 */
1561 pppol2tp_tunnel_inc_refcount(tunnel);
1562
1563 /* Mark socket as an encapsulation socket. See net/ipv4/udp.c */
1564 (udp_sk(sk))->encap_type = UDP_ENCAP_L2TPINUDP;
1565 (udp_sk(sk))->encap_rcv = pppol2tp_udp_encap_recv;
1566
1567 ret = tunnel->sock;
1568
1569 *error = 0;
1570 out:
1571 if (sock)
1572 sockfd_put(sock);
1573
1574 return ret;
1575
1576 err:
1577 *error = err;
1578 goto out;
1579 }
1580
1581 static struct proto pppol2tp_sk_proto = {
1582 .name = "PPPOL2TP",
1583 .owner = THIS_MODULE,
1584 .obj_size = sizeof(struct pppox_sock),
1585 };
1586
1587 /* socket() handler. Initialize a new struct sock.
1588 */
1589 static int pppol2tp_create(struct net *net, struct socket *sock)
1590 {
1591 int error = -ENOMEM;
1592 struct sock *sk;
1593
1594 sk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, &pppol2tp_sk_proto);
1595 if (!sk)
1596 goto out;
1597
1598 sock_init_data(sock, sk);
1599
1600 sock->state = SS_UNCONNECTED;
1601 sock->ops = &pppol2tp_ops;
1602
1603 sk->sk_backlog_rcv = pppol2tp_recv_core;
1604 sk->sk_protocol = PX_PROTO_OL2TP;
1605 sk->sk_family = PF_PPPOX;
1606 sk->sk_state = PPPOX_NONE;
1607 sk->sk_type = SOCK_STREAM;
1608 sk->sk_destruct = pppol2tp_session_destruct;
1609
1610 error = 0;
1611
1612 out:
1613 return error;
1614 }
1615
1616 /* connect() handler. Attach a PPPoX socket to a tunnel UDP socket
1617 */
1618 static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr,
1619 int sockaddr_len, int flags)
1620 {
1621 struct sock *sk = sock->sk;
1622 struct sockaddr_pppol2tp *sp = (struct sockaddr_pppol2tp *) uservaddr;
1623 struct pppox_sock *po = pppox_sk(sk);
1624 struct sock *tunnel_sock = NULL;
1625 struct pppol2tp_session *session = NULL;
1626 struct pppol2tp_tunnel *tunnel;
1627 struct dst_entry *dst;
1628 int error = 0;
1629
1630 lock_sock(sk);
1631
1632 error = -EINVAL;
1633 if (sp->sa_protocol != PX_PROTO_OL2TP)
1634 goto end;
1635
1636 /* Check for already bound sockets */
1637 error = -EBUSY;
1638 if (sk->sk_state & PPPOX_CONNECTED)
1639 goto end;
1640
1641 /* We don't supporting rebinding anyway */
1642 error = -EALREADY;
1643 if (sk->sk_user_data)
1644 goto end; /* socket is already attached */
1645
1646 /* Don't bind if s_tunnel is 0 */
1647 error = -EINVAL;
1648 if (sp->pppol2tp.s_tunnel == 0)
1649 goto end;
1650
1651 /* Special case: prepare tunnel socket if s_session and
1652 * d_session is 0. Otherwise look up tunnel using supplied
1653 * tunnel id.
1654 */
1655 if ((sp->pppol2tp.s_session == 0) && (sp->pppol2tp.d_session == 0)) {
1656 tunnel_sock = pppol2tp_prepare_tunnel_socket(sock_net(sk),
1657 sp->pppol2tp.fd,
1658 sp->pppol2tp.s_tunnel,
1659 &error);
1660 if (tunnel_sock == NULL)
1661 goto end;
1662
1663 sock_hold(tunnel_sock);
1664 tunnel = tunnel_sock->sk_user_data;
1665 } else {
1666 tunnel = pppol2tp_tunnel_find(sock_net(sk), sp->pppol2tp.s_tunnel);
1667
1668 /* Error if we can't find the tunnel */
1669 error = -ENOENT;
1670 if (tunnel == NULL)
1671 goto end;
1672
1673 tunnel_sock = tunnel->sock;
1674 }
1675
1676 /* Check that this session doesn't already exist */
1677 error = -EEXIST;
1678 session = pppol2tp_session_find(tunnel, sp->pppol2tp.s_session);
1679 if (session != NULL)
1680 goto end;
1681
1682 /* Allocate and initialize a new session context. */
1683 session = kzalloc(sizeof(struct pppol2tp_session), GFP_KERNEL);
1684 if (session == NULL) {
1685 error = -ENOMEM;
1686 goto end;
1687 }
1688
1689 skb_queue_head_init(&session->reorder_q);
1690
1691 session->magic = L2TP_SESSION_MAGIC;
1692 session->owner = current->pid;
1693 session->sock = sk;
1694 session->tunnel = tunnel;
1695 session->tunnel_sock = tunnel_sock;
1696 session->tunnel_addr = sp->pppol2tp;
1697 sprintf(&session->name[0], "sess %hu/%hu",
1698 session->tunnel_addr.s_tunnel,
1699 session->tunnel_addr.s_session);
1700
1701 session->stats.tunnel_id = session->tunnel_addr.s_tunnel;
1702 session->stats.session_id = session->tunnel_addr.s_session;
1703
1704 INIT_HLIST_NODE(&session->hlist);
1705
1706 /* Inherit debug options from tunnel */
1707 session->debug = tunnel->debug;
1708
1709 /* Default MTU must allow space for UDP/L2TP/PPP
1710 * headers.
1711 */
1712 session->mtu = session->mru = 1500 - PPPOL2TP_HEADER_OVERHEAD;
1713
1714 /* If PMTU discovery was enabled, use the MTU that was discovered */
1715 dst = sk_dst_get(sk);
1716 if (dst != NULL) {
1717 u32 pmtu = dst_mtu(__sk_dst_get(sk));
1718 if (pmtu != 0)
1719 session->mtu = session->mru = pmtu -
1720 PPPOL2TP_HEADER_OVERHEAD;
1721 dst_release(dst);
1722 }
1723
1724 /* Special case: if source & dest session_id == 0x0000, this socket is
1725 * being created to manage the tunnel. Don't add the session to the
1726 * session hash list, just set up the internal context for use by
1727 * ioctl() and sockopt() handlers.
1728 */
1729 if ((session->tunnel_addr.s_session == 0) &&
1730 (session->tunnel_addr.d_session == 0)) {
1731 error = 0;
1732 sk->sk_user_data = session;
1733 goto out_no_ppp;
1734 }
1735
1736 /* Get tunnel context from the tunnel socket */
1737 tunnel = pppol2tp_sock_to_tunnel(tunnel_sock);
1738 if (tunnel == NULL) {
1739 error = -EBADF;
1740 goto end;
1741 }
1742
1743 /* Right now, because we don't have a way to push the incoming skb's
1744 * straight through the UDP layer, the only header we need to worry
1745 * about is the L2TP header. This size is different depending on
1746 * whether sequence numbers are enabled for the data channel.
1747 */
1748 po->chan.hdrlen = PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
1749
1750 po->chan.private = sk;
1751 po->chan.ops = &pppol2tp_chan_ops;
1752 po->chan.mtu = session->mtu;
1753
1754 error = ppp_register_net_channel(sock_net(sk), &po->chan);
1755 if (error)
1756 goto end_put_tun;
1757
1758 /* This is how we get the session context from the socket. */
1759 sk->sk_user_data = session;
1760
1761 /* Add session to the tunnel's hash list */
1762 write_lock_bh(&tunnel->hlist_lock);
1763 hlist_add_head(&session->hlist,
1764 pppol2tp_session_id_hash(tunnel,
1765 session->tunnel_addr.s_session));
1766 write_unlock_bh(&tunnel->hlist_lock);
1767
1768 atomic_inc(&pppol2tp_session_count);
1769
1770 out_no_ppp:
1771 pppol2tp_tunnel_inc_refcount(tunnel);
1772 sk->sk_state = PPPOX_CONNECTED;
1773 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1774 "%s: created\n", session->name);
1775
1776 end_put_tun:
1777 sock_put(tunnel_sock);
1778 end:
1779 release_sock(sk);
1780
1781 if (error != 0) {
1782 if (session)
1783 PRINTK(session->debug,
1784 PPPOL2TP_MSG_CONTROL, KERN_WARNING,
1785 "%s: connect failed: %d\n",
1786 session->name, error);
1787 else
1788 PRINTK(-1, PPPOL2TP_MSG_CONTROL, KERN_WARNING,
1789 "connect failed: %d\n", error);
1790 }
1791
1792 return error;
1793 }
1794
1795 /* getname() support.
1796 */
1797 static int pppol2tp_getname(struct socket *sock, struct sockaddr *uaddr,
1798 int *usockaddr_len, int peer)
1799 {
1800 int len = sizeof(struct sockaddr_pppol2tp);
1801 struct sockaddr_pppol2tp sp;
1802 int error = 0;
1803 struct pppol2tp_session *session;
1804
1805 error = -ENOTCONN;
1806 if (sock->sk->sk_state != PPPOX_CONNECTED)
1807 goto end;
1808
1809 session = pppol2tp_sock_to_session(sock->sk);
1810 if (session == NULL) {
1811 error = -EBADF;
1812 goto end;
1813 }
1814
1815 sp.sa_family = AF_PPPOX;
1816 sp.sa_protocol = PX_PROTO_OL2TP;
1817 memcpy(&sp.pppol2tp, &session->tunnel_addr,
1818 sizeof(struct pppol2tp_addr));
1819
1820 memcpy(uaddr, &sp, len);
1821
1822 *usockaddr_len = len;
1823
1824 error = 0;
1825 sock_put(sock->sk);
1826
1827 end:
1828 return error;
1829 }
1830
1831 /****************************************************************************
1832 * ioctl() handlers.
1833 *
1834 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
1835 * sockets. However, in order to control kernel tunnel features, we allow
1836 * userspace to create a special "tunnel" PPPoX socket which is used for
1837 * control only. Tunnel PPPoX sockets have session_id == 0 and simply allow
1838 * the user application to issue L2TP setsockopt(), getsockopt() and ioctl()
1839 * calls.
1840 ****************************************************************************/
1841
1842 /* Session ioctl helper.
1843 */
1844 static int pppol2tp_session_ioctl(struct pppol2tp_session *session,
1845 unsigned int cmd, unsigned long arg)
1846 {
1847 struct ifreq ifr;
1848 int err = 0;
1849 struct sock *sk = session->sock;
1850 int val = (int) arg;
1851
1852 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_DEBUG,
1853 "%s: pppol2tp_session_ioctl(cmd=%#x, arg=%#lx)\n",
1854 session->name, cmd, arg);
1855
1856 sock_hold(sk);
1857
1858 switch (cmd) {
1859 case SIOCGIFMTU:
1860 err = -ENXIO;
1861 if (!(sk->sk_state & PPPOX_CONNECTED))
1862 break;
1863
1864 err = -EFAULT;
1865 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq)))
1866 break;
1867 ifr.ifr_mtu = session->mtu;
1868 if (copy_to_user((void __user *) arg, &ifr, sizeof(struct ifreq)))
1869 break;
1870
1871 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1872 "%s: get mtu=%d\n", session->name, session->mtu);
1873 err = 0;
1874 break;
1875
1876 case SIOCSIFMTU:
1877 err = -ENXIO;
1878 if (!(sk->sk_state & PPPOX_CONNECTED))
1879 break;
1880
1881 err = -EFAULT;
1882 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq)))
1883 break;
1884
1885 session->mtu = ifr.ifr_mtu;
1886
1887 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1888 "%s: set mtu=%d\n", session->name, session->mtu);
1889 err = 0;
1890 break;
1891
1892 case PPPIOCGMRU:
1893 err = -ENXIO;
1894 if (!(sk->sk_state & PPPOX_CONNECTED))
1895 break;
1896
1897 err = -EFAULT;
1898 if (put_user(session->mru, (int __user *) arg))
1899 break;
1900
1901 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1902 "%s: get mru=%d\n", session->name, session->mru);
1903 err = 0;
1904 break;
1905
1906 case PPPIOCSMRU:
1907 err = -ENXIO;
1908 if (!(sk->sk_state & PPPOX_CONNECTED))
1909 break;
1910
1911 err = -EFAULT;
1912 if (get_user(val,(int __user *) arg))
1913 break;
1914
1915 session->mru = val;
1916 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1917 "%s: set mru=%d\n", session->name, session->mru);
1918 err = 0;
1919 break;
1920
1921 case PPPIOCGFLAGS:
1922 err = -EFAULT;
1923 if (put_user(session->flags, (int __user *) arg))
1924 break;
1925
1926 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1927 "%s: get flags=%d\n", session->name, session->flags);
1928 err = 0;
1929 break;
1930
1931 case PPPIOCSFLAGS:
1932 err = -EFAULT;
1933 if (get_user(val, (int __user *) arg))
1934 break;
1935 session->flags = val;
1936 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1937 "%s: set flags=%d\n", session->name, session->flags);
1938 err = 0;
1939 break;
1940
1941 case PPPIOCGL2TPSTATS:
1942 err = -ENXIO;
1943 if (!(sk->sk_state & PPPOX_CONNECTED))
1944 break;
1945
1946 if (copy_to_user((void __user *) arg, &session->stats,
1947 sizeof(session->stats)))
1948 break;
1949 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1950 "%s: get L2TP stats\n", session->name);
1951 err = 0;
1952 break;
1953
1954 default:
1955 err = -ENOSYS;
1956 break;
1957 }
1958
1959 sock_put(sk);
1960
1961 return err;
1962 }
1963
1964 /* Tunnel ioctl helper.
1965 *
1966 * Note the special handling for PPPIOCGL2TPSTATS below. If the ioctl data
1967 * specifies a session_id, the session ioctl handler is called. This allows an
1968 * application to retrieve session stats via a tunnel socket.
1969 */
1970 static int pppol2tp_tunnel_ioctl(struct pppol2tp_tunnel *tunnel,
1971 unsigned int cmd, unsigned long arg)
1972 {
1973 int err = 0;
1974 struct sock *sk = tunnel->sock;
1975 struct pppol2tp_ioc_stats stats_req;
1976
1977 PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_DEBUG,
1978 "%s: pppol2tp_tunnel_ioctl(cmd=%#x, arg=%#lx)\n", tunnel->name,
1979 cmd, arg);
1980
1981 sock_hold(sk);
1982
1983 switch (cmd) {
1984 case PPPIOCGL2TPSTATS:
1985 err = -ENXIO;
1986 if (!(sk->sk_state & PPPOX_CONNECTED))
1987 break;
1988
1989 if (copy_from_user(&stats_req, (void __user *) arg,
1990 sizeof(stats_req))) {
1991 err = -EFAULT;
1992 break;
1993 }
1994 if (stats_req.session_id != 0) {
1995 /* resend to session ioctl handler */
1996 struct pppol2tp_session *session =
1997 pppol2tp_session_find(tunnel, stats_req.session_id);
1998 if (session != NULL)
1999 err = pppol2tp_session_ioctl(session, cmd, arg);
2000 else
2001 err = -EBADR;
2002 break;
2003 }
2004 #ifdef CONFIG_XFRM
2005 tunnel->stats.using_ipsec = (sk->sk_policy[0] || sk->sk_policy[1]) ? 1 : 0;
2006 #endif
2007 if (copy_to_user((void __user *) arg, &tunnel->stats,
2008 sizeof(tunnel->stats))) {
2009 err = -EFAULT;
2010 break;
2011 }
2012 PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2013 "%s: get L2TP stats\n", tunnel->name);
2014 err = 0;
2015 break;
2016
2017 default:
2018 err = -ENOSYS;
2019 break;
2020 }
2021
2022 sock_put(sk);
2023
2024 return err;
2025 }
2026
2027 /* Main ioctl() handler.
2028 * Dispatch to tunnel or session helpers depending on the socket.
2029 */
2030 static int pppol2tp_ioctl(struct socket *sock, unsigned int cmd,
2031 unsigned long arg)
2032 {
2033 struct sock *sk = sock->sk;
2034 struct pppol2tp_session *session;
2035 struct pppol2tp_tunnel *tunnel;
2036 int err;
2037
2038 if (!sk)
2039 return 0;
2040
2041 err = -EBADF;
2042 if (sock_flag(sk, SOCK_DEAD) != 0)
2043 goto end;
2044
2045 err = -ENOTCONN;
2046 if ((sk->sk_user_data == NULL) ||
2047 (!(sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND))))
2048 goto end;
2049
2050 /* Get session context from the socket */
2051 err = -EBADF;
2052 session = pppol2tp_sock_to_session(sk);
2053 if (session == NULL)
2054 goto end;
2055
2056 /* Special case: if session's session_id is zero, treat ioctl as a
2057 * tunnel ioctl
2058 */
2059 if ((session->tunnel_addr.s_session == 0) &&
2060 (session->tunnel_addr.d_session == 0)) {
2061 err = -EBADF;
2062 tunnel = pppol2tp_sock_to_tunnel(session->tunnel_sock);
2063 if (tunnel == NULL)
2064 goto end_put_sess;
2065
2066 err = pppol2tp_tunnel_ioctl(tunnel, cmd, arg);
2067 sock_put(session->tunnel_sock);
2068 goto end_put_sess;
2069 }
2070
2071 err = pppol2tp_session_ioctl(session, cmd, arg);
2072
2073 end_put_sess:
2074 sock_put(sk);
2075 end:
2076 return err;
2077 }
2078
2079 /*****************************************************************************
2080 * setsockopt() / getsockopt() support.
2081 *
2082 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
2083 * sockets. In order to control kernel tunnel features, we allow userspace to
2084 * create a special "tunnel" PPPoX socket which is used for control only.
2085 * Tunnel PPPoX sockets have session_id == 0 and simply allow the user
2086 * application to issue L2TP setsockopt(), getsockopt() and ioctl() calls.
2087 *****************************************************************************/
2088
2089 /* Tunnel setsockopt() helper.
2090 */
2091 static int pppol2tp_tunnel_setsockopt(struct sock *sk,
2092 struct pppol2tp_tunnel *tunnel,
2093 int optname, int val)
2094 {
2095 int err = 0;
2096
2097 switch (optname) {
2098 case PPPOL2TP_SO_DEBUG:
2099 tunnel->debug = val;
2100 PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2101 "%s: set debug=%x\n", tunnel->name, tunnel->debug);
2102 break;
2103
2104 default:
2105 err = -ENOPROTOOPT;
2106 break;
2107 }
2108
2109 return err;
2110 }
2111
2112 /* Session setsockopt helper.
2113 */
2114 static int pppol2tp_session_setsockopt(struct sock *sk,
2115 struct pppol2tp_session *session,
2116 int optname, int val)
2117 {
2118 int err = 0;
2119
2120 switch (optname) {
2121 case PPPOL2TP_SO_RECVSEQ:
2122 if ((val != 0) && (val != 1)) {
2123 err = -EINVAL;
2124 break;
2125 }
2126 session->recv_seq = val ? -1 : 0;
2127 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2128 "%s: set recv_seq=%d\n", session->name,
2129 session->recv_seq);
2130 break;
2131
2132 case PPPOL2TP_SO_SENDSEQ:
2133 if ((val != 0) && (val != 1)) {
2134 err = -EINVAL;
2135 break;
2136 }
2137 session->send_seq = val ? -1 : 0;
2138 {
2139 struct sock *ssk = session->sock;
2140 struct pppox_sock *po = pppox_sk(ssk);
2141 po->chan.hdrlen = val ? PPPOL2TP_L2TP_HDR_SIZE_SEQ :
2142 PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
2143 }
2144 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2145 "%s: set send_seq=%d\n", session->name, session->send_seq);
2146 break;
2147
2148 case PPPOL2TP_SO_LNSMODE:
2149 if ((val != 0) && (val != 1)) {
2150 err = -EINVAL;
2151 break;
2152 }
2153 session->lns_mode = val ? -1 : 0;
2154 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2155 "%s: set lns_mode=%d\n", session->name,
2156 session->lns_mode);
2157 break;
2158
2159 case PPPOL2TP_SO_DEBUG:
2160 session->debug = val;
2161 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2162 "%s: set debug=%x\n", session->name, session->debug);
2163 break;
2164
2165 case PPPOL2TP_SO_REORDERTO:
2166 session->reorder_timeout = msecs_to_jiffies(val);
2167 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2168 "%s: set reorder_timeout=%d\n", session->name,
2169 session->reorder_timeout);
2170 break;
2171
2172 default:
2173 err = -ENOPROTOOPT;
2174 break;
2175 }
2176
2177 return err;
2178 }
2179
2180 /* Main setsockopt() entry point.
2181 * Does API checks, then calls either the tunnel or session setsockopt
2182 * handler, according to whether the PPPoL2TP socket is a for a regular
2183 * session or the special tunnel type.
2184 */
2185 static int pppol2tp_setsockopt(struct socket *sock, int level, int optname,
2186 char __user *optval, unsigned int optlen)
2187 {
2188 struct sock *sk = sock->sk;
2189 struct pppol2tp_session *session = sk->sk_user_data;
2190 struct pppol2tp_tunnel *tunnel;
2191 int val;
2192 int err;
2193
2194 if (level != SOL_PPPOL2TP)
2195 return udp_prot.setsockopt(sk, level, optname, optval, optlen);
2196
2197 if (optlen < sizeof(int))
2198 return -EINVAL;
2199
2200 if (get_user(val, (int __user *)optval))
2201 return -EFAULT;
2202
2203 err = -ENOTCONN;
2204 if (sk->sk_user_data == NULL)
2205 goto end;
2206
2207 /* Get session context from the socket */
2208 err = -EBADF;
2209 session = pppol2tp_sock_to_session(sk);
2210 if (session == NULL)
2211 goto end;
2212
2213 /* Special case: if session_id == 0x0000, treat as operation on tunnel
2214 */
2215 if ((session->tunnel_addr.s_session == 0) &&
2216 (session->tunnel_addr.d_session == 0)) {
2217 err = -EBADF;
2218 tunnel = pppol2tp_sock_to_tunnel(session->tunnel_sock);
2219 if (tunnel == NULL)
2220 goto end_put_sess;
2221
2222 err = pppol2tp_tunnel_setsockopt(sk, tunnel, optname, val);
2223 sock_put(session->tunnel_sock);
2224 } else
2225 err = pppol2tp_session_setsockopt(sk, session, optname, val);
2226
2227 err = 0;
2228
2229 end_put_sess:
2230 sock_put(sk);
2231 end:
2232 return err;
2233 }
2234
2235 /* Tunnel getsockopt helper. Called with sock locked.
2236 */
2237 static int pppol2tp_tunnel_getsockopt(struct sock *sk,
2238 struct pppol2tp_tunnel *tunnel,
2239 int optname, int *val)
2240 {
2241 int err = 0;
2242
2243 switch (optname) {
2244 case PPPOL2TP_SO_DEBUG:
2245 *val = tunnel->debug;
2246 PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2247 "%s: get debug=%x\n", tunnel->name, tunnel->debug);
2248 break;
2249
2250 default:
2251 err = -ENOPROTOOPT;
2252 break;
2253 }
2254
2255 return err;
2256 }
2257
2258 /* Session getsockopt helper. Called with sock locked.
2259 */
2260 static int pppol2tp_session_getsockopt(struct sock *sk,
2261 struct pppol2tp_session *session,
2262 int optname, int *val)
2263 {
2264 int err = 0;
2265
2266 switch (optname) {
2267 case PPPOL2TP_SO_RECVSEQ:
2268 *val = session->recv_seq;
2269 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2270 "%s: get recv_seq=%d\n", session->name, *val);
2271 break;
2272
2273 case PPPOL2TP_SO_SENDSEQ:
2274 *val = session->send_seq;
2275 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2276 "%s: get send_seq=%d\n", session->name, *val);
2277 break;
2278
2279 case PPPOL2TP_SO_LNSMODE:
2280 *val = session->lns_mode;
2281 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2282 "%s: get lns_mode=%d\n", session->name, *val);
2283 break;
2284
2285 case PPPOL2TP_SO_DEBUG:
2286 *val = session->debug;
2287 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2288 "%s: get debug=%d\n", session->name, *val);
2289 break;
2290
2291 case PPPOL2TP_SO_REORDERTO:
2292 *val = (int) jiffies_to_msecs(session->reorder_timeout);
2293 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2294 "%s: get reorder_timeout=%d\n", session->name, *val);
2295 break;
2296
2297 default:
2298 err = -ENOPROTOOPT;
2299 }
2300
2301 return err;
2302 }
2303
2304 /* Main getsockopt() entry point.
2305 * Does API checks, then calls either the tunnel or session getsockopt
2306 * handler, according to whether the PPPoX socket is a for a regular session
2307 * or the special tunnel type.
2308 */
2309 static int pppol2tp_getsockopt(struct socket *sock, int level,
2310 int optname, char __user *optval, int __user *optlen)
2311 {
2312 struct sock *sk = sock->sk;
2313 struct pppol2tp_session *session = sk->sk_user_data;
2314 struct pppol2tp_tunnel *tunnel;
2315 int val, len;
2316 int err;
2317
2318 if (level != SOL_PPPOL2TP)
2319 return udp_prot.getsockopt(sk, level, optname, optval, optlen);
2320
2321 if (get_user(len, (int __user *) optlen))
2322 return -EFAULT;
2323
2324 len = min_t(unsigned int, len, sizeof(int));
2325
2326 if (len < 0)
2327 return -EINVAL;
2328
2329 err = -ENOTCONN;
2330 if (sk->sk_user_data == NULL)
2331 goto end;
2332
2333 /* Get the session context */
2334 err = -EBADF;
2335 session = pppol2tp_sock_to_session(sk);
2336 if (session == NULL)
2337 goto end;
2338
2339 /* Special case: if session_id == 0x0000, treat as operation on tunnel */
2340 if ((session->tunnel_addr.s_session == 0) &&
2341 (session->tunnel_addr.d_session == 0)) {
2342 err = -EBADF;
2343 tunnel = pppol2tp_sock_to_tunnel(session->tunnel_sock);
2344 if (tunnel == NULL)
2345 goto end_put_sess;
2346
2347 err = pppol2tp_tunnel_getsockopt(sk, tunnel, optname, &val);
2348 sock_put(session->tunnel_sock);
2349 } else
2350 err = pppol2tp_session_getsockopt(sk, session, optname, &val);
2351
2352 err = -EFAULT;
2353 if (put_user(len, (int __user *) optlen))
2354 goto end_put_sess;
2355
2356 if (copy_to_user((void __user *) optval, &val, len))
2357 goto end_put_sess;
2358
2359 err = 0;
2360
2361 end_put_sess:
2362 sock_put(sk);
2363 end:
2364 return err;
2365 }
2366
2367 /*****************************************************************************
2368 * /proc filesystem for debug
2369 *****************************************************************************/
2370
2371 #ifdef CONFIG_PROC_FS
2372
2373 #include <linux/seq_file.h>
2374
2375 struct pppol2tp_seq_data {
2376 struct seq_net_private p;
2377 struct pppol2tp_tunnel *tunnel; /* current tunnel */
2378 struct pppol2tp_session *session; /* NULL means get first session in tunnel */
2379 };
2380
2381 static struct pppol2tp_session *next_session(struct pppol2tp_tunnel *tunnel, struct pppol2tp_session *curr)
2382 {
2383 struct pppol2tp_session *session = NULL;
2384 struct hlist_node *walk;
2385 int found = 0;
2386 int next = 0;
2387 int i;
2388
2389 read_lock_bh(&tunnel->hlist_lock);
2390 for (i = 0; i < PPPOL2TP_HASH_SIZE; i++) {
2391 hlist_for_each_entry(session, walk, &tunnel->session_hlist[i], hlist) {
2392 if (curr == NULL) {
2393 found = 1;
2394 goto out;
2395 }
2396 if (session == curr) {
2397 next = 1;
2398 continue;
2399 }
2400 if (next) {
2401 found = 1;
2402 goto out;
2403 }
2404 }
2405 }
2406 out:
2407 read_unlock_bh(&tunnel->hlist_lock);
2408 if (!found)
2409 session = NULL;
2410
2411 return session;
2412 }
2413
2414 static struct pppol2tp_tunnel *next_tunnel(struct pppol2tp_net *pn,
2415 struct pppol2tp_tunnel *curr)
2416 {
2417 struct pppol2tp_tunnel *tunnel = NULL;
2418
2419 read_lock_bh(&pn->pppol2tp_tunnel_list_lock);
2420 if (list_is_last(&curr->list, &pn->pppol2tp_tunnel_list)) {
2421 goto out;
2422 }
2423 tunnel = list_entry(curr->list.next, struct pppol2tp_tunnel, list);
2424 out:
2425 read_unlock_bh(&pn->pppol2tp_tunnel_list_lock);
2426
2427 return tunnel;
2428 }
2429
2430 static void *pppol2tp_seq_start(struct seq_file *m, loff_t *offs)
2431 {
2432 struct pppol2tp_seq_data *pd = SEQ_START_TOKEN;
2433 struct pppol2tp_net *pn;
2434 loff_t pos = *offs;
2435
2436 if (!pos)
2437 goto out;
2438
2439 BUG_ON(m->private == NULL);
2440 pd = m->private;
2441 pn = pppol2tp_pernet(seq_file_net(m));
2442
2443 if (pd->tunnel == NULL) {
2444 if (!list_empty(&pn->pppol2tp_tunnel_list))
2445 pd->tunnel = list_entry(pn->pppol2tp_tunnel_list.next, struct pppol2tp_tunnel, list);
2446 } else {
2447 pd->session = next_session(pd->tunnel, pd->session);
2448 if (pd->session == NULL) {
2449 pd->tunnel = next_tunnel(pn, pd->tunnel);
2450 }
2451 }
2452
2453 /* NULL tunnel and session indicates end of list */
2454 if ((pd->tunnel == NULL) && (pd->session == NULL))
2455 pd = NULL;
2456
2457 out:
2458 return pd;
2459 }
2460
2461 static void *pppol2tp_seq_next(struct seq_file *m, void *v, loff_t *pos)
2462 {
2463 (*pos)++;
2464 return NULL;
2465 }
2466
2467 static void pppol2tp_seq_stop(struct seq_file *p, void *v)
2468 {
2469 /* nothing to do */
2470 }
2471
2472 static void pppol2tp_seq_tunnel_show(struct seq_file *m, void *v)
2473 {
2474 struct pppol2tp_tunnel *tunnel = v;
2475
2476 seq_printf(m, "\nTUNNEL '%s', %c %d\n",
2477 tunnel->name,
2478 (tunnel == tunnel->sock->sk_user_data) ? 'Y':'N',
2479 atomic_read(&tunnel->ref_count) - 1);
2480 seq_printf(m, " %08x %llu/%llu/%llu %llu/%llu/%llu\n",
2481 tunnel->debug,
2482 (unsigned long long)tunnel->stats.tx_packets,
2483 (unsigned long long)tunnel->stats.tx_bytes,
2484 (unsigned long long)tunnel->stats.tx_errors,
2485 (unsigned long long)tunnel->stats.rx_packets,
2486 (unsigned long long)tunnel->stats.rx_bytes,
2487 (unsigned long long)tunnel->stats.rx_errors);
2488 }
2489
2490 static void pppol2tp_seq_session_show(struct seq_file *m, void *v)
2491 {
2492 struct pppol2tp_session *session = v;
2493
2494 seq_printf(m, " SESSION '%s' %08X/%d %04X/%04X -> "
2495 "%04X/%04X %d %c\n",
2496 session->name,
2497 ntohl(session->tunnel_addr.addr.sin_addr.s_addr),
2498 ntohs(session->tunnel_addr.addr.sin_port),
2499 session->tunnel_addr.s_tunnel,
2500 session->tunnel_addr.s_session,
2501 session->tunnel_addr.d_tunnel,
2502 session->tunnel_addr.d_session,
2503 session->sock->sk_state,
2504 (session == session->sock->sk_user_data) ?
2505 'Y' : 'N');
2506 seq_printf(m, " %d/%d/%c/%c/%s %08x %u\n",
2507 session->mtu, session->mru,
2508 session->recv_seq ? 'R' : '-',
2509 session->send_seq ? 'S' : '-',
2510 session->lns_mode ? "LNS" : "LAC",
2511 session->debug,
2512 jiffies_to_msecs(session->reorder_timeout));
2513 seq_printf(m, " %hu/%hu %llu/%llu/%llu %llu/%llu/%llu\n",
2514 session->nr, session->ns,
2515 (unsigned long long)session->stats.tx_packets,
2516 (unsigned long long)session->stats.tx_bytes,
2517 (unsigned long long)session->stats.tx_errors,
2518 (unsigned long long)session->stats.rx_packets,
2519 (unsigned long long)session->stats.rx_bytes,
2520 (unsigned long long)session->stats.rx_errors);
2521 }
2522
2523 static int pppol2tp_seq_show(struct seq_file *m, void *v)
2524 {
2525 struct pppol2tp_seq_data *pd = v;
2526
2527 /* display header on line 1 */
2528 if (v == SEQ_START_TOKEN) {
2529 seq_puts(m, "PPPoL2TP driver info, " PPPOL2TP_DRV_VERSION "\n");
2530 seq_puts(m, "TUNNEL name, user-data-ok session-count\n");
2531 seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
2532 seq_puts(m, " SESSION name, addr/port src-tid/sid "
2533 "dest-tid/sid state user-data-ok\n");
2534 seq_puts(m, " mtu/mru/rcvseq/sendseq/lns debug reorderto\n");
2535 seq_puts(m, " nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
2536 goto out;
2537 }
2538
2539 /* Show the tunnel or session context.
2540 */
2541 if (pd->session == NULL)
2542 pppol2tp_seq_tunnel_show(m, pd->tunnel);
2543 else
2544 pppol2tp_seq_session_show(m, pd->session);
2545
2546 out:
2547 return 0;
2548 }
2549
2550 static const struct seq_operations pppol2tp_seq_ops = {
2551 .start = pppol2tp_seq_start,
2552 .next = pppol2tp_seq_next,
2553 .stop = pppol2tp_seq_stop,
2554 .show = pppol2tp_seq_show,
2555 };
2556
2557 /* Called when our /proc file is opened. We allocate data for use when
2558 * iterating our tunnel / session contexts and store it in the private
2559 * data of the seq_file.
2560 */
2561 static int pppol2tp_proc_open(struct inode *inode, struct file *file)
2562 {
2563 return seq_open_net(inode, file, &pppol2tp_seq_ops,
2564 sizeof(struct pppol2tp_seq_data));
2565 }
2566
2567 static const struct file_operations pppol2tp_proc_fops = {
2568 .owner = THIS_MODULE,
2569 .open = pppol2tp_proc_open,
2570 .read = seq_read,
2571 .llseek = seq_lseek,
2572 .release = seq_release_net,
2573 };
2574
2575 #endif /* CONFIG_PROC_FS */
2576
2577 /*****************************************************************************
2578 * Init and cleanup
2579 *****************************************************************************/
2580
2581 static const struct proto_ops pppol2tp_ops = {
2582 .family = AF_PPPOX,
2583 .owner = THIS_MODULE,
2584 .release = pppol2tp_release,
2585 .bind = sock_no_bind,
2586 .connect = pppol2tp_connect,
2587 .socketpair = sock_no_socketpair,
2588 .accept = sock_no_accept,
2589 .getname = pppol2tp_getname,
2590 .poll = datagram_poll,
2591 .listen = sock_no_listen,
2592 .shutdown = sock_no_shutdown,
2593 .setsockopt = pppol2tp_setsockopt,
2594 .getsockopt = pppol2tp_getsockopt,
2595 .sendmsg = pppol2tp_sendmsg,
2596 .recvmsg = pppol2tp_recvmsg,
2597 .mmap = sock_no_mmap,
2598 .ioctl = pppox_ioctl,
2599 };
2600
2601 static struct pppox_proto pppol2tp_proto = {
2602 .create = pppol2tp_create,
2603 .ioctl = pppol2tp_ioctl
2604 };
2605
2606 static __net_init int pppol2tp_init_net(struct net *net)
2607 {
2608 struct pppol2tp_net *pn;
2609 struct proc_dir_entry *pde;
2610 int err;
2611
2612 pn = kzalloc(sizeof(*pn), GFP_KERNEL);
2613 if (!pn)
2614 return -ENOMEM;
2615
2616 INIT_LIST_HEAD(&pn->pppol2tp_tunnel_list);
2617 rwlock_init(&pn->pppol2tp_tunnel_list_lock);
2618
2619 err = net_assign_generic(net, pppol2tp_net_id, pn);
2620 if (err)
2621 goto out;
2622
2623 pde = proc_net_fops_create(net, "pppol2tp", S_IRUGO, &pppol2tp_proc_fops);
2624 #ifdef CONFIG_PROC_FS
2625 if (!pde) {
2626 err = -ENOMEM;
2627 goto out;
2628 }
2629 #endif
2630
2631 return 0;
2632
2633 out:
2634 kfree(pn);
2635 return err;
2636 }
2637
2638 static __net_exit void pppol2tp_exit_net(struct net *net)
2639 {
2640 struct pppoe_net *pn;
2641
2642 proc_net_remove(net, "pppol2tp");
2643 pn = net_generic(net, pppol2tp_net_id);
2644 /*
2645 * if someone has cached our net then
2646 * further net_generic call will return NULL
2647 */
2648 net_assign_generic(net, pppol2tp_net_id, NULL);
2649 kfree(pn);
2650 }
2651
2652 static struct pernet_operations pppol2tp_net_ops = {
2653 .init = pppol2tp_init_net,
2654 .exit = pppol2tp_exit_net,
2655 };
2656
2657 static int __init pppol2tp_init(void)
2658 {
2659 int err;
2660
2661 err = proto_register(&pppol2tp_sk_proto, 0);
2662 if (err)
2663 goto out;
2664 err = register_pppox_proto(PX_PROTO_OL2TP, &pppol2tp_proto);
2665 if (err)
2666 goto out_unregister_pppol2tp_proto;
2667
2668 err = register_pernet_gen_device(&pppol2tp_net_id, &pppol2tp_net_ops);
2669 if (err)
2670 goto out_unregister_pppox_proto;
2671
2672 printk(KERN_INFO "PPPoL2TP kernel driver, %s\n",
2673 PPPOL2TP_DRV_VERSION);
2674
2675 out:
2676 return err;
2677 out_unregister_pppox_proto:
2678 unregister_pppox_proto(PX_PROTO_OL2TP);
2679 out_unregister_pppol2tp_proto:
2680 proto_unregister(&pppol2tp_sk_proto);
2681 goto out;
2682 }
2683
2684 static void __exit pppol2tp_exit(void)
2685 {
2686 unregister_pppox_proto(PX_PROTO_OL2TP);
2687 unregister_pernet_gen_device(pppol2tp_net_id, &pppol2tp_net_ops);
2688 proto_unregister(&pppol2tp_sk_proto);
2689 }
2690
2691 module_init(pppol2tp_init);
2692 module_exit(pppol2tp_exit);
2693
2694 MODULE_AUTHOR("Martijn van Oosterhout <kleptog@svana.org>, "
2695 "James Chapman <jchapman@katalix.com>");
2696 MODULE_DESCRIPTION("PPP over L2TP over UDP");
2697 MODULE_LICENSE("GPL");
2698 MODULE_VERSION(PPPOL2TP_DRV_VERSION);
Linux ARM platform port for MOXA ART SoC