clocksource: improve sh_cmt clocksource overflow handling
[linux-2.6.git] / drivers / net / pppol2tp.c
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 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                 dst_release(skb->dst);
437                 skb->dst = NULL;
438                 nf_reset(skb);
439
440                 po = pppox_sk(session_sock);
441                 ppp_input(&po->chan, skb);
442         } else {
443                 PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_INFO,
444                        "%s: socket not bound\n", session->name);
445
446                 /* Not bound. Nothing we can do, so discard. */
447                 session->stats.rx_errors++;
448                 kfree_skb(skb);
449         }
450
451         sock_put(session->sock);
452 }
453
454 /* Dequeue skbs from the session's reorder_q, subject to packet order.
455  * Skbs that have been in the queue for too long are simply discarded.
456  */
457 static void pppol2tp_recv_dequeue(struct pppol2tp_session *session)
458 {
459         struct sk_buff *skb;
460         struct sk_buff *tmp;
461
462         /* If the pkt at the head of the queue has the nr that we
463          * expect to send up next, dequeue it and any other
464          * in-sequence packets behind it.
465          */
466         spin_lock_bh(&session->reorder_q.lock);
467         skb_queue_walk_safe(&session->reorder_q, skb, tmp) {
468                 if (time_after(jiffies, PPPOL2TP_SKB_CB(skb)->expires)) {
469                         session->stats.rx_seq_discards++;
470                         session->stats.rx_errors++;
471                         PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
472                                "%s: oos pkt %hu len %d discarded (too old), "
473                                "waiting for %hu, reorder_q_len=%d\n",
474                                session->name, PPPOL2TP_SKB_CB(skb)->ns,
475                                PPPOL2TP_SKB_CB(skb)->length, session->nr,
476                                skb_queue_len(&session->reorder_q));
477                         __skb_unlink(skb, &session->reorder_q);
478                         kfree_skb(skb);
479                         sock_put(session->sock);
480                         continue;
481                 }
482
483                 if (PPPOL2TP_SKB_CB(skb)->has_seq) {
484                         if (PPPOL2TP_SKB_CB(skb)->ns != session->nr) {
485                                 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
486                                        "%s: holding oos pkt %hu len %d, "
487                                        "waiting for %hu, reorder_q_len=%d\n",
488                                        session->name, PPPOL2TP_SKB_CB(skb)->ns,
489                                        PPPOL2TP_SKB_CB(skb)->length, session->nr,
490                                        skb_queue_len(&session->reorder_q));
491                                 goto out;
492                         }
493                 }
494                 __skb_unlink(skb, &session->reorder_q);
495
496                 /* Process the skb. We release the queue lock while we
497                  * do so to let other contexts process the queue.
498                  */
499                 spin_unlock_bh(&session->reorder_q.lock);
500                 pppol2tp_recv_dequeue_skb(session, skb);
501                 spin_lock_bh(&session->reorder_q.lock);
502         }
503
504 out:
505         spin_unlock_bh(&session->reorder_q.lock);
506 }
507
508 static inline int pppol2tp_verify_udp_checksum(struct sock *sk,
509                                                struct sk_buff *skb)
510 {
511         struct udphdr *uh = udp_hdr(skb);
512         u16 ulen = ntohs(uh->len);
513         struct inet_sock *inet;
514         __wsum psum;
515
516         if (sk->sk_no_check || skb_csum_unnecessary(skb) || !uh->check)
517                 return 0;
518
519         inet = inet_sk(sk);
520         psum = csum_tcpudp_nofold(inet->saddr, inet->daddr, ulen,
521                                   IPPROTO_UDP, 0);
522
523         if ((skb->ip_summed == CHECKSUM_COMPLETE) &&
524             !csum_fold(csum_add(psum, skb->csum)))
525                 return 0;
526
527         skb->csum = psum;
528
529         return __skb_checksum_complete(skb);
530 }
531
532 /* Internal receive frame. Do the real work of receiving an L2TP data frame
533  * here. The skb is not on a list when we get here.
534  * Returns 0 if the packet was a data packet and was successfully passed on.
535  * Returns 1 if the packet was not a good data packet and could not be
536  * forwarded.  All such packets are passed up to userspace to deal with.
537  */
538 static int pppol2tp_recv_core(struct sock *sock, struct sk_buff *skb)
539 {
540         struct pppol2tp_session *session = NULL;
541         struct pppol2tp_tunnel *tunnel;
542         unsigned char *ptr, *optr;
543         u16 hdrflags;
544         u16 tunnel_id, session_id;
545         int length;
546         int offset;
547
548         tunnel = pppol2tp_sock_to_tunnel(sock);
549         if (tunnel == NULL)
550                 goto no_tunnel;
551
552         if (tunnel->sock && pppol2tp_verify_udp_checksum(tunnel->sock, skb))
553                 goto discard_bad_csum;
554
555         /* UDP always verifies the packet length. */
556         __skb_pull(skb, sizeof(struct udphdr));
557
558         /* Short packet? */
559         if (!pskb_may_pull(skb, 12)) {
560                 PRINTK(tunnel->debug, PPPOL2TP_MSG_DATA, KERN_INFO,
561                        "%s: recv short packet (len=%d)\n", tunnel->name, skb->len);
562                 goto error;
563         }
564
565         /* Point to L2TP header */
566         optr = ptr = skb->data;
567
568         /* Get L2TP header flags */
569         hdrflags = ntohs(*(__be16*)ptr);
570
571         /* Trace packet contents, if enabled */
572         if (tunnel->debug & PPPOL2TP_MSG_DATA) {
573                 length = min(16u, skb->len);
574                 if (!pskb_may_pull(skb, length))
575                         goto error;
576
577                 printk(KERN_DEBUG "%s: recv: ", tunnel->name);
578
579                 offset = 0;
580                 do {
581                         printk(" %02X", ptr[offset]);
582                 } while (++offset < length);
583
584                 printk("\n");
585         }
586
587         /* Get length of L2TP packet */
588         length = skb->len;
589
590         /* If type is control packet, it is handled by userspace. */
591         if (hdrflags & L2TP_HDRFLAG_T) {
592                 PRINTK(tunnel->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
593                        "%s: recv control packet, len=%d\n", tunnel->name, length);
594                 goto error;
595         }
596
597         /* Skip flags */
598         ptr += 2;
599
600         /* If length is present, skip it */
601         if (hdrflags & L2TP_HDRFLAG_L)
602                 ptr += 2;
603
604         /* Extract tunnel and session ID */
605         tunnel_id = ntohs(*(__be16 *) ptr);
606         ptr += 2;
607         session_id = ntohs(*(__be16 *) ptr);
608         ptr += 2;
609
610         /* Find the session context */
611         session = pppol2tp_session_find(tunnel, session_id);
612         if (!session) {
613                 /* Not found? Pass to userspace to deal with */
614                 PRINTK(tunnel->debug, PPPOL2TP_MSG_DATA, KERN_INFO,
615                        "%s: no socket found (%hu/%hu). Passing up.\n",
616                        tunnel->name, tunnel_id, session_id);
617                 goto error;
618         }
619         sock_hold(session->sock);
620
621         /* The ref count on the socket was increased by the above call since
622          * we now hold a pointer to the session. Take care to do sock_put()
623          * when exiting this function from now on...
624          */
625
626         /* Handle the optional sequence numbers.  If we are the LAC,
627          * enable/disable sequence numbers under the control of the LNS.  If
628          * no sequence numbers present but we were expecting them, discard
629          * frame.
630          */
631         if (hdrflags & L2TP_HDRFLAG_S) {
632                 u16 ns, nr;
633                 ns = ntohs(*(__be16 *) ptr);
634                 ptr += 2;
635                 nr = ntohs(*(__be16 *) ptr);
636                 ptr += 2;
637
638                 /* Received a packet with sequence numbers. If we're the LNS,
639                  * check if we sre sending sequence numbers and if not,
640                  * configure it so.
641                  */
642                 if ((!session->lns_mode) && (!session->send_seq)) {
643                         PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_INFO,
644                                "%s: requested to enable seq numbers by LNS\n",
645                                session->name);
646                         session->send_seq = -1;
647                 }
648
649                 /* Store L2TP info in the skb */
650                 PPPOL2TP_SKB_CB(skb)->ns = ns;
651                 PPPOL2TP_SKB_CB(skb)->nr = nr;
652                 PPPOL2TP_SKB_CB(skb)->has_seq = 1;
653
654                 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
655                        "%s: recv data ns=%hu, nr=%hu, session nr=%hu\n",
656                        session->name, ns, nr, session->nr);
657         } else {
658                 /* No sequence numbers.
659                  * If user has configured mandatory sequence numbers, discard.
660                  */
661                 if (session->recv_seq) {
662                         PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_WARNING,
663                                "%s: recv data has no seq numbers when required. "
664                                "Discarding\n", session->name);
665                         session->stats.rx_seq_discards++;
666                         goto discard;
667                 }
668
669                 /* If we're the LAC and we're sending sequence numbers, the
670                  * LNS has requested that we no longer send sequence numbers.
671                  * If we're the LNS and we're sending sequence numbers, the
672                  * LAC is broken. Discard the frame.
673                  */
674                 if ((!session->lns_mode) && (session->send_seq)) {
675                         PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_INFO,
676                                "%s: requested to disable seq numbers by LNS\n",
677                                session->name);
678                         session->send_seq = 0;
679                 } else if (session->send_seq) {
680                         PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_WARNING,
681                                "%s: recv data has no seq numbers when required. "
682                                "Discarding\n", session->name);
683                         session->stats.rx_seq_discards++;
684                         goto discard;
685                 }
686
687                 /* Store L2TP info in the skb */
688                 PPPOL2TP_SKB_CB(skb)->has_seq = 0;
689         }
690
691         /* If offset bit set, skip it. */
692         if (hdrflags & L2TP_HDRFLAG_O) {
693                 offset = ntohs(*(__be16 *)ptr);
694                 ptr += 2 + offset;
695         }
696
697         offset = ptr - optr;
698         if (!pskb_may_pull(skb, offset))
699                 goto discard;
700
701         __skb_pull(skb, offset);
702
703         /* Skip PPP header, if present.  In testing, Microsoft L2TP clients
704          * don't send the PPP header (PPP header compression enabled), but
705          * other clients can include the header. So we cope with both cases
706          * here. The PPP header is always FF03 when using L2TP.
707          *
708          * Note that skb->data[] isn't dereferenced from a u16 ptr here since
709          * the field may be unaligned.
710          */
711         if (!pskb_may_pull(skb, 2))
712                 goto discard;
713
714         if ((skb->data[0] == 0xff) && (skb->data[1] == 0x03))
715                 skb_pull(skb, 2);
716
717         /* Prepare skb for adding to the session's reorder_q.  Hold
718          * packets for max reorder_timeout or 1 second if not
719          * reordering.
720          */
721         PPPOL2TP_SKB_CB(skb)->length = length;
722         PPPOL2TP_SKB_CB(skb)->expires = jiffies +
723                 (session->reorder_timeout ? session->reorder_timeout : HZ);
724
725         /* Add packet to the session's receive queue. Reordering is done here, if
726          * enabled. Saved L2TP protocol info is stored in skb->sb[].
727          */
728         if (PPPOL2TP_SKB_CB(skb)->has_seq) {
729                 if (session->reorder_timeout != 0) {
730                         /* Packet reordering enabled. Add skb to session's
731                          * reorder queue, in order of ns.
732                          */
733                         pppol2tp_recv_queue_skb(session, skb);
734                 } else {
735                         /* Packet reordering disabled. Discard out-of-sequence
736                          * packets
737                          */
738                         if (PPPOL2TP_SKB_CB(skb)->ns != session->nr) {
739                                 session->stats.rx_seq_discards++;
740                                 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
741                                        "%s: oos pkt %hu len %d discarded, "
742                                        "waiting for %hu, reorder_q_len=%d\n",
743                                        session->name, PPPOL2TP_SKB_CB(skb)->ns,
744                                        PPPOL2TP_SKB_CB(skb)->length, session->nr,
745                                        skb_queue_len(&session->reorder_q));
746                                 goto discard;
747                         }
748                         skb_queue_tail(&session->reorder_q, skb);
749                 }
750         } else {
751                 /* No sequence numbers. Add the skb to the tail of the
752                  * reorder queue. This ensures that it will be
753                  * delivered after all previous sequenced skbs.
754                  */
755                 skb_queue_tail(&session->reorder_q, skb);
756         }
757
758         /* Try to dequeue as many skbs from reorder_q as we can. */
759         pppol2tp_recv_dequeue(session);
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
777         return 0;
778
779 error:
780         /* Put UDP header back */
781         __skb_push(skb, sizeof(struct udphdr));
782         sock_put(sock);
783
784 no_tunnel:
785         return 1;
786 }
787
788 /* UDP encapsulation receive handler. See net/ipv4/udp.c.
789  * Return codes:
790  * 0 : success.
791  * <0: error
792  * >0: skb should be passed up to userspace as UDP.
793  */
794 static int pppol2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
795 {
796         struct pppol2tp_tunnel *tunnel;
797
798         tunnel = pppol2tp_sock_to_tunnel(sk);
799         if (tunnel == NULL)
800                 goto pass_up;
801
802         PRINTK(tunnel->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
803                "%s: received %d bytes\n", tunnel->name, skb->len);
804
805         if (pppol2tp_recv_core(sk, skb))
806                 goto pass_up_put;
807
808         sock_put(sk);
809         return 0;
810
811 pass_up_put:
812         sock_put(sk);
813 pass_up:
814         return 1;
815 }
816
817 /* Receive message. This is the recvmsg for the PPPoL2TP socket.
818  */
819 static int pppol2tp_recvmsg(struct kiocb *iocb, struct socket *sock,
820                             struct msghdr *msg, size_t len,
821                             int flags)
822 {
823         int err;
824         struct sk_buff *skb;
825         struct sock *sk = sock->sk;
826
827         err = -EIO;
828         if (sk->sk_state & PPPOX_BOUND)
829                 goto end;
830
831         msg->msg_namelen = 0;
832
833         err = 0;
834         skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
835                                 flags & MSG_DONTWAIT, &err);
836         if (!skb)
837                 goto end;
838
839         if (len > skb->len)
840                 len = skb->len;
841         else if (len < skb->len)
842                 msg->msg_flags |= MSG_TRUNC;
843
844         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len);
845         if (likely(err == 0))
846                 err = len;
847
848         kfree_skb(skb);
849 end:
850         return err;
851 }
852
853 /************************************************************************
854  * Transmit handling
855  ***********************************************************************/
856
857 /* Tell how big L2TP headers are for a particular session. This
858  * depends on whether sequence numbers are being used.
859  */
860 static inline int pppol2tp_l2tp_header_len(struct pppol2tp_session *session)
861 {
862         if (session->send_seq)
863                 return PPPOL2TP_L2TP_HDR_SIZE_SEQ;
864
865         return PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
866 }
867
868 /* Build an L2TP header for the session into the buffer provided.
869  */
870 static void pppol2tp_build_l2tp_header(struct pppol2tp_session *session,
871                                        void *buf)
872 {
873         __be16 *bufp = buf;
874         u16 flags = L2TP_HDR_VER;
875
876         if (session->send_seq)
877                 flags |= L2TP_HDRFLAG_S;
878
879         /* Setup L2TP header.
880          * FIXME: Can this ever be unaligned? Is direct dereferencing of
881          * 16-bit header fields safe here for all architectures?
882          */
883         *bufp++ = htons(flags);
884         *bufp++ = htons(session->tunnel_addr.d_tunnel);
885         *bufp++ = htons(session->tunnel_addr.d_session);
886         if (session->send_seq) {
887                 *bufp++ = htons(session->ns);
888                 *bufp++ = 0;
889                 session->ns++;
890                 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
891                        "%s: updated ns to %hu\n", session->name, session->ns);
892         }
893 }
894
895 /* This is the sendmsg for the PPPoL2TP pppol2tp_session socket.  We come here
896  * when a user application does a sendmsg() on the session socket. L2TP and
897  * PPP headers must be inserted into the user's data.
898  */
899 static int pppol2tp_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
900                             size_t total_len)
901 {
902         static const unsigned char ppph[2] = { 0xff, 0x03 };
903         struct sock *sk = sock->sk;
904         struct inet_sock *inet;
905         __wsum csum;
906         struct sk_buff *skb;
907         int error;
908         int hdr_len;
909         struct pppol2tp_session *session;
910         struct pppol2tp_tunnel *tunnel;
911         struct udphdr *uh;
912         unsigned int len;
913         struct sock *sk_tun;
914         u16 udp_len;
915
916         error = -ENOTCONN;
917         if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
918                 goto error;
919
920         /* Get session and tunnel contexts */
921         error = -EBADF;
922         session = pppol2tp_sock_to_session(sk);
923         if (session == NULL)
924                 goto error;
925
926         sk_tun = session->tunnel_sock;
927         tunnel = pppol2tp_sock_to_tunnel(sk_tun);
928         if (tunnel == NULL)
929                 goto error_put_sess;
930
931         /* What header length is configured for this session? */
932         hdr_len = pppol2tp_l2tp_header_len(session);
933
934         /* Allocate a socket buffer */
935         error = -ENOMEM;
936         skb = sock_wmalloc(sk, NET_SKB_PAD + sizeof(struct iphdr) +
937                            sizeof(struct udphdr) + hdr_len +
938                            sizeof(ppph) + total_len,
939                            0, GFP_KERNEL);
940         if (!skb)
941                 goto error_put_sess_tun;
942
943         /* Reserve space for headers. */
944         skb_reserve(skb, NET_SKB_PAD);
945         skb_reset_network_header(skb);
946         skb_reserve(skb, sizeof(struct iphdr));
947         skb_reset_transport_header(skb);
948
949         /* Build UDP header */
950         inet = inet_sk(sk_tun);
951         udp_len = hdr_len + sizeof(ppph) + total_len;
952         uh = (struct udphdr *) skb->data;
953         uh->source = inet->sport;
954         uh->dest = inet->dport;
955         uh->len = htons(udp_len);
956         uh->check = 0;
957         skb_put(skb, sizeof(struct udphdr));
958
959         /* Build L2TP header */
960         pppol2tp_build_l2tp_header(session, skb->data);
961         skb_put(skb, hdr_len);
962
963         /* Add PPP header */
964         skb->data[0] = ppph[0];
965         skb->data[1] = ppph[1];
966         skb_put(skb, 2);
967
968         /* Copy user data into skb */
969         error = memcpy_fromiovec(skb->data, m->msg_iov, total_len);
970         if (error < 0) {
971                 kfree_skb(skb);
972                 goto error_put_sess_tun;
973         }
974         skb_put(skb, total_len);
975
976         /* Calculate UDP checksum if configured to do so */
977         if (sk_tun->sk_no_check == UDP_CSUM_NOXMIT)
978                 skb->ip_summed = CHECKSUM_NONE;
979         else if (!(skb->dst->dev->features & NETIF_F_V4_CSUM)) {
980                 skb->ip_summed = CHECKSUM_COMPLETE;
981                 csum = skb_checksum(skb, 0, udp_len, 0);
982                 uh->check = csum_tcpudp_magic(inet->saddr, inet->daddr,
983                                               udp_len, IPPROTO_UDP, csum);
984                 if (uh->check == 0)
985                         uh->check = CSUM_MANGLED_0;
986         } else {
987                 skb->ip_summed = CHECKSUM_PARTIAL;
988                 skb->csum_start = skb_transport_header(skb) - skb->head;
989                 skb->csum_offset = offsetof(struct udphdr, check);
990                 uh->check = ~csum_tcpudp_magic(inet->saddr, inet->daddr,
991                                                udp_len, IPPROTO_UDP, 0);
992         }
993
994         /* Debug */
995         if (session->send_seq)
996                 PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
997                        "%s: send %Zd bytes, ns=%hu\n", session->name,
998                        total_len, session->ns - 1);
999         else
1000                 PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
1001                        "%s: send %Zd bytes\n", session->name, total_len);
1002
1003         if (session->debug & PPPOL2TP_MSG_DATA) {
1004                 int i;
1005                 unsigned char *datap = skb->data;
1006
1007                 printk(KERN_DEBUG "%s: xmit:", session->name);
1008                 for (i = 0; i < total_len; i++) {
1009                         printk(" %02X", *datap++);
1010                         if (i == 15) {
1011                                 printk(" ...");
1012                                 break;
1013                         }
1014                 }
1015                 printk("\n");
1016         }
1017
1018         /* Queue the packet to IP for output */
1019         len = skb->len;
1020         error = ip_queue_xmit(skb, 1);
1021
1022         /* Update stats */
1023         if (error >= 0) {
1024                 tunnel->stats.tx_packets++;
1025                 tunnel->stats.tx_bytes += len;
1026                 session->stats.tx_packets++;
1027                 session->stats.tx_bytes += len;
1028         } else {
1029                 tunnel->stats.tx_errors++;
1030                 session->stats.tx_errors++;
1031         }
1032
1033         return error;
1034
1035 error_put_sess_tun:
1036         sock_put(session->tunnel_sock);
1037 error_put_sess:
1038         sock_put(sk);
1039 error:
1040         return error;
1041 }
1042
1043 /* Automatically called when the skb is freed.
1044  */
1045 static void pppol2tp_sock_wfree(struct sk_buff *skb)
1046 {
1047         sock_put(skb->sk);
1048 }
1049
1050 /* For data skbs that we transmit, we associate with the tunnel socket
1051  * but don't do accounting.
1052  */
1053 static inline void pppol2tp_skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
1054 {
1055         sock_hold(sk);
1056         skb->sk = sk;
1057         skb->destructor = pppol2tp_sock_wfree;
1058 }
1059
1060 /* Transmit function called by generic PPP driver.  Sends PPP frame
1061  * over PPPoL2TP socket.
1062  *
1063  * This is almost the same as pppol2tp_sendmsg(), but rather than
1064  * being called with a msghdr from userspace, it is called with a skb
1065  * from the kernel.
1066  *
1067  * The supplied skb from ppp doesn't have enough headroom for the
1068  * insertion of L2TP, UDP and IP headers so we need to allocate more
1069  * headroom in the skb. This will create a cloned skb. But we must be
1070  * careful in the error case because the caller will expect to free
1071  * the skb it supplied, not our cloned skb. So we take care to always
1072  * leave the original skb unfreed if we return an error.
1073  */
1074 static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
1075 {
1076         static const u8 ppph[2] = { 0xff, 0x03 };
1077         struct sock *sk = (struct sock *) chan->private;
1078         struct sock *sk_tun;
1079         int hdr_len;
1080         u16 udp_len;
1081         struct pppol2tp_session *session;
1082         struct pppol2tp_tunnel *tunnel;
1083         int rc;
1084         int headroom;
1085         int data_len = skb->len;
1086         struct inet_sock *inet;
1087         __wsum csum;
1088         struct udphdr *uh;
1089         unsigned int len;
1090         int old_headroom;
1091         int new_headroom;
1092
1093         if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
1094                 goto abort;
1095
1096         /* Get session and tunnel contexts from the socket */
1097         session = pppol2tp_sock_to_session(sk);
1098         if (session == NULL)
1099                 goto abort;
1100
1101         sk_tun = session->tunnel_sock;
1102         if (sk_tun == NULL)
1103                 goto abort_put_sess;
1104         tunnel = pppol2tp_sock_to_tunnel(sk_tun);
1105         if (tunnel == NULL)
1106                 goto abort_put_sess;
1107
1108         /* What header length is configured for this session? */
1109         hdr_len = pppol2tp_l2tp_header_len(session);
1110
1111         /* Check that there's enough headroom in the skb to insert IP,
1112          * UDP and L2TP and PPP headers. If not enough, expand it to
1113          * make room. Adjust truesize.
1114          */
1115         headroom = NET_SKB_PAD + sizeof(struct iphdr) +
1116                 sizeof(struct udphdr) + hdr_len + sizeof(ppph);
1117         old_headroom = skb_headroom(skb);
1118         if (skb_cow_head(skb, headroom))
1119                 goto abort_put_sess_tun;
1120
1121         new_headroom = skb_headroom(skb);
1122         skb_orphan(skb);
1123         skb->truesize += new_headroom - old_headroom;
1124
1125         /* Setup PPP header */
1126         __skb_push(skb, sizeof(ppph));
1127         skb->data[0] = ppph[0];
1128         skb->data[1] = ppph[1];
1129
1130         /* Setup L2TP header */
1131         pppol2tp_build_l2tp_header(session, __skb_push(skb, hdr_len));
1132
1133         udp_len = sizeof(struct udphdr) + hdr_len + sizeof(ppph) + data_len;
1134
1135         /* Setup UDP header */
1136         inet = inet_sk(sk_tun);
1137         __skb_push(skb, sizeof(*uh));
1138         skb_reset_transport_header(skb);
1139         uh = udp_hdr(skb);
1140         uh->source = inet->sport;
1141         uh->dest = inet->dport;
1142         uh->len = htons(udp_len);
1143         uh->check = 0;
1144
1145         /* Debug */
1146         if (session->send_seq)
1147                 PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
1148                        "%s: send %d bytes, ns=%hu\n", session->name,
1149                        data_len, session->ns - 1);
1150         else
1151                 PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
1152                        "%s: send %d bytes\n", session->name, data_len);
1153
1154         if (session->debug & PPPOL2TP_MSG_DATA) {
1155                 int i;
1156                 unsigned char *datap = skb->data;
1157
1158                 printk(KERN_DEBUG "%s: xmit:", session->name);
1159                 for (i = 0; i < data_len; i++) {
1160                         printk(" %02X", *datap++);
1161                         if (i == 31) {
1162                                 printk(" ...");
1163                                 break;
1164                         }
1165                 }
1166                 printk("\n");
1167         }
1168
1169         memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1170         IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED |
1171                               IPSKB_REROUTED);
1172         nf_reset(skb);
1173
1174         /* Get routing info from the tunnel socket */
1175         dst_release(skb->dst);
1176         skb->dst = dst_clone(__sk_dst_get(sk_tun));
1177         pppol2tp_skb_set_owner_w(skb, sk_tun);
1178
1179         /* Calculate UDP checksum if configured to do so */
1180         if (sk_tun->sk_no_check == UDP_CSUM_NOXMIT)
1181                 skb->ip_summed = CHECKSUM_NONE;
1182         else if (!(skb->dst->dev->features & NETIF_F_V4_CSUM)) {
1183                 skb->ip_summed = CHECKSUM_COMPLETE;
1184                 csum = skb_checksum(skb, 0, udp_len, 0);
1185                 uh->check = csum_tcpudp_magic(inet->saddr, inet->daddr,
1186                                               udp_len, IPPROTO_UDP, csum);
1187                 if (uh->check == 0)
1188                         uh->check = CSUM_MANGLED_0;
1189         } else {
1190                 skb->ip_summed = CHECKSUM_PARTIAL;
1191                 skb->csum_start = skb_transport_header(skb) - skb->head;
1192                 skb->csum_offset = offsetof(struct udphdr, check);
1193                 uh->check = ~csum_tcpudp_magic(inet->saddr, inet->daddr,
1194                                                udp_len, IPPROTO_UDP, 0);
1195         }
1196
1197         /* Queue the packet to IP for output */
1198         len = skb->len;
1199         rc = ip_queue_xmit(skb, 1);
1200
1201         /* Update stats */
1202         if (rc >= 0) {
1203                 tunnel->stats.tx_packets++;
1204                 tunnel->stats.tx_bytes += len;
1205                 session->stats.tx_packets++;
1206                 session->stats.tx_bytes += len;
1207         } else {
1208                 tunnel->stats.tx_errors++;
1209                 session->stats.tx_errors++;
1210         }
1211
1212         sock_put(sk_tun);
1213         sock_put(sk);
1214         return 1;
1215
1216 abort_put_sess_tun:
1217         sock_put(sk_tun);
1218 abort_put_sess:
1219         sock_put(sk);
1220 abort:
1221         /* Free the original skb */
1222         kfree_skb(skb);
1223         return 1;
1224 }
1225
1226 /*****************************************************************************
1227  * Session (and tunnel control) socket create/destroy.
1228  *****************************************************************************/
1229
1230 /* When the tunnel UDP socket is closed, all the attached sockets need to go
1231  * too.
1232  */
1233 static void pppol2tp_tunnel_closeall(struct pppol2tp_tunnel *tunnel)
1234 {
1235         int hash;
1236         struct hlist_node *walk;
1237         struct hlist_node *tmp;
1238         struct pppol2tp_session *session;
1239         struct sock *sk;
1240
1241         if (tunnel == NULL)
1242                 BUG();
1243
1244         PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1245                "%s: closing all sessions...\n", tunnel->name);
1246
1247         write_lock_bh(&tunnel->hlist_lock);
1248         for (hash = 0; hash < PPPOL2TP_HASH_SIZE; hash++) {
1249 again:
1250                 hlist_for_each_safe(walk, tmp, &tunnel->session_hlist[hash]) {
1251                         struct sk_buff *skb;
1252
1253                         session = hlist_entry(walk, struct pppol2tp_session, hlist);
1254
1255                         sk = session->sock;
1256
1257                         PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1258                                "%s: closing session\n", session->name);
1259
1260                         hlist_del_init(&session->hlist);
1261
1262                         /* Since we should hold the sock lock while
1263                          * doing any unbinding, we need to release the
1264                          * lock we're holding before taking that lock.
1265                          * Hold a reference to the sock so it doesn't
1266                          * disappear as we're jumping between locks.
1267                          */
1268                         sock_hold(sk);
1269                         write_unlock_bh(&tunnel->hlist_lock);
1270                         lock_sock(sk);
1271
1272                         if (sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND)) {
1273                                 pppox_unbind_sock(sk);
1274                                 sk->sk_state = PPPOX_DEAD;
1275                                 sk->sk_state_change(sk);
1276                         }
1277
1278                         /* Purge any queued data */
1279                         skb_queue_purge(&sk->sk_receive_queue);
1280                         skb_queue_purge(&sk->sk_write_queue);
1281                         while ((skb = skb_dequeue(&session->reorder_q))) {
1282                                 kfree_skb(skb);
1283                                 sock_put(sk);
1284                         }
1285
1286                         release_sock(sk);
1287                         sock_put(sk);
1288
1289                         /* Now restart from the beginning of this hash
1290                          * chain.  We always remove a session from the
1291                          * list so we are guaranteed to make forward
1292                          * progress.
1293                          */
1294                         write_lock_bh(&tunnel->hlist_lock);
1295                         goto again;
1296                 }
1297         }
1298         write_unlock_bh(&tunnel->hlist_lock);
1299 }
1300
1301 /* Really kill the tunnel.
1302  * Come here only when all sessions have been cleared from the tunnel.
1303  */
1304 static void pppol2tp_tunnel_free(struct pppol2tp_tunnel *tunnel)
1305 {
1306         struct pppol2tp_net *pn = pppol2tp_pernet(tunnel->pppol2tp_net);
1307
1308         /* Remove from socket list */
1309         write_lock_bh(&pn->pppol2tp_tunnel_list_lock);
1310         list_del_init(&tunnel->list);
1311         write_unlock_bh(&pn->pppol2tp_tunnel_list_lock);
1312
1313         atomic_dec(&pppol2tp_tunnel_count);
1314         kfree(tunnel);
1315 }
1316
1317 /* Tunnel UDP socket destruct hook.
1318  * The tunnel context is deleted only when all session sockets have been
1319  * closed.
1320  */
1321 static void pppol2tp_tunnel_destruct(struct sock *sk)
1322 {
1323         struct pppol2tp_tunnel *tunnel;
1324
1325         tunnel = sk->sk_user_data;
1326         if (tunnel == NULL)
1327                 goto end;
1328
1329         PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1330                "%s: closing...\n", tunnel->name);
1331
1332         /* Close all sessions */
1333         pppol2tp_tunnel_closeall(tunnel);
1334
1335         /* No longer an encapsulation socket. See net/ipv4/udp.c */
1336         (udp_sk(sk))->encap_type = 0;
1337         (udp_sk(sk))->encap_rcv = NULL;
1338
1339         /* Remove hooks into tunnel socket */
1340         tunnel->sock = NULL;
1341         sk->sk_destruct = tunnel->old_sk_destruct;
1342         sk->sk_user_data = NULL;
1343
1344         /* Call original (UDP) socket descructor */
1345         if (sk->sk_destruct != NULL)
1346                 (*sk->sk_destruct)(sk);
1347
1348         pppol2tp_tunnel_dec_refcount(tunnel);
1349
1350 end:
1351         return;
1352 }
1353
1354 /* Really kill the session socket. (Called from sock_put() if
1355  * refcnt == 0.)
1356  */
1357 static void pppol2tp_session_destruct(struct sock *sk)
1358 {
1359         struct pppol2tp_session *session = NULL;
1360
1361         if (sk->sk_user_data != NULL) {
1362                 struct pppol2tp_tunnel *tunnel;
1363
1364                 session = sk->sk_user_data;
1365                 if (session == NULL)
1366                         goto out;
1367
1368                 BUG_ON(session->magic != L2TP_SESSION_MAGIC);
1369
1370                 /* Don't use pppol2tp_sock_to_tunnel() here to
1371                  * get the tunnel context because the tunnel
1372                  * socket might have already been closed (its
1373                  * sk->sk_user_data will be NULL) so use the
1374                  * session's private tunnel ptr instead.
1375                  */
1376                 tunnel = session->tunnel;
1377                 if (tunnel != NULL) {
1378                         BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);
1379
1380                         /* If session_id is zero, this is a null
1381                          * session context, which was created for a
1382                          * socket that is being used only to manage
1383                          * tunnels.
1384                          */
1385                         if (session->tunnel_addr.s_session != 0) {
1386                                 /* Delete the session socket from the
1387                                  * hash
1388                                  */
1389                                 write_lock_bh(&tunnel->hlist_lock);
1390                                 hlist_del_init(&session->hlist);
1391                                 write_unlock_bh(&tunnel->hlist_lock);
1392
1393                                 atomic_dec(&pppol2tp_session_count);
1394                         }
1395
1396                         /* This will delete the tunnel context if this
1397                          * is the last session on the tunnel.
1398                          */
1399                         session->tunnel = NULL;
1400                         session->tunnel_sock = NULL;
1401                         pppol2tp_tunnel_dec_refcount(tunnel);
1402                 }
1403         }
1404
1405         kfree(session);
1406 out:
1407         return;
1408 }
1409
1410 /* Called when the PPPoX socket (session) is closed.
1411  */
1412 static int pppol2tp_release(struct socket *sock)
1413 {
1414         struct sock *sk = sock->sk;
1415         struct pppol2tp_session *session;
1416         int error;
1417
1418         if (!sk)
1419                 return 0;
1420
1421         error = -EBADF;
1422         lock_sock(sk);
1423         if (sock_flag(sk, SOCK_DEAD) != 0)
1424                 goto error;
1425
1426         pppox_unbind_sock(sk);
1427
1428         /* Signal the death of the socket. */
1429         sk->sk_state = PPPOX_DEAD;
1430         sock_orphan(sk);
1431         sock->sk = NULL;
1432
1433         session = pppol2tp_sock_to_session(sk);
1434
1435         /* Purge any queued data */
1436         skb_queue_purge(&sk->sk_receive_queue);
1437         skb_queue_purge(&sk->sk_write_queue);
1438         if (session != NULL) {
1439                 struct sk_buff *skb;
1440                 while ((skb = skb_dequeue(&session->reorder_q))) {
1441                         kfree_skb(skb);
1442                         sock_put(sk);
1443                 }
1444                 sock_put(sk);
1445         }
1446
1447         release_sock(sk);
1448
1449         /* This will delete the session context via
1450          * pppol2tp_session_destruct() if the socket's refcnt drops to
1451          * zero.
1452          */
1453         sock_put(sk);
1454
1455         return 0;
1456
1457 error:
1458         release_sock(sk);
1459         return error;
1460 }
1461
1462 /* Internal function to prepare a tunnel (UDP) socket to have PPPoX
1463  * sockets attached to it.
1464  */
1465 static struct sock *pppol2tp_prepare_tunnel_socket(struct net *net,
1466                                         int fd, u16 tunnel_id, int *error)
1467 {
1468         int err;
1469         struct socket *sock = NULL;
1470         struct sock *sk;
1471         struct pppol2tp_tunnel *tunnel;
1472         struct pppol2tp_net *pn;
1473         struct sock *ret = NULL;
1474
1475         /* Get the tunnel UDP socket from the fd, which was opened by
1476          * the userspace L2TP daemon.
1477          */
1478         err = -EBADF;
1479         sock = sockfd_lookup(fd, &err);
1480         if (!sock) {
1481                 PRINTK(-1, PPPOL2TP_MSG_CONTROL, KERN_ERR,
1482                        "tunl %hu: sockfd_lookup(fd=%d) returned %d\n",
1483                        tunnel_id, fd, err);
1484                 goto err;
1485         }
1486
1487         sk = sock->sk;
1488
1489         /* Quick sanity checks */
1490         err = -EPROTONOSUPPORT;
1491         if (sk->sk_protocol != IPPROTO_UDP) {
1492                 PRINTK(-1, PPPOL2TP_MSG_CONTROL, KERN_ERR,
1493                        "tunl %hu: fd %d wrong protocol, got %d, expected %d\n",
1494                        tunnel_id, fd, sk->sk_protocol, IPPROTO_UDP);
1495                 goto err;
1496         }
1497         err = -EAFNOSUPPORT;
1498         if (sock->ops->family != AF_INET) {
1499                 PRINTK(-1, PPPOL2TP_MSG_CONTROL, KERN_ERR,
1500                        "tunl %hu: fd %d wrong family, got %d, expected %d\n",
1501                        tunnel_id, fd, sock->ops->family, AF_INET);
1502                 goto err;
1503         }
1504
1505         err = -ENOTCONN;
1506
1507         /* Check if this socket has already been prepped */
1508         tunnel = (struct pppol2tp_tunnel *)sk->sk_user_data;
1509         if (tunnel != NULL) {
1510                 /* User-data field already set */
1511                 err = -EBUSY;
1512                 BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);
1513
1514                 /* This socket has already been prepped */
1515                 ret = tunnel->sock;
1516                 goto out;
1517         }
1518
1519         /* This socket is available and needs prepping. Create a new tunnel
1520          * context and init it.
1521          */
1522         sk->sk_user_data = tunnel = kzalloc(sizeof(struct pppol2tp_tunnel), GFP_KERNEL);
1523         if (sk->sk_user_data == NULL) {
1524                 err = -ENOMEM;
1525                 goto err;
1526         }
1527
1528         tunnel->magic = L2TP_TUNNEL_MAGIC;
1529         sprintf(&tunnel->name[0], "tunl %hu", tunnel_id);
1530
1531         tunnel->stats.tunnel_id = tunnel_id;
1532         tunnel->debug = PPPOL2TP_DEFAULT_DEBUG_FLAGS;
1533
1534         /* Hook on the tunnel socket destructor so that we can cleanup
1535          * if the tunnel socket goes away.
1536          */
1537         tunnel->old_sk_destruct = sk->sk_destruct;
1538         sk->sk_destruct = &pppol2tp_tunnel_destruct;
1539
1540         tunnel->sock = sk;
1541         sk->sk_allocation = GFP_ATOMIC;
1542
1543         /* Misc init */
1544         rwlock_init(&tunnel->hlist_lock);
1545
1546         /* The net we belong to */
1547         tunnel->pppol2tp_net = net;
1548         pn = pppol2tp_pernet(net);
1549
1550         /* Add tunnel to our list */
1551         INIT_LIST_HEAD(&tunnel->list);
1552         write_lock_bh(&pn->pppol2tp_tunnel_list_lock);
1553         list_add(&tunnel->list, &pn->pppol2tp_tunnel_list);
1554         write_unlock_bh(&pn->pppol2tp_tunnel_list_lock);
1555         atomic_inc(&pppol2tp_tunnel_count);
1556
1557         /* Bump the reference count. The tunnel context is deleted
1558          * only when this drops to zero.
1559          */
1560         pppol2tp_tunnel_inc_refcount(tunnel);
1561
1562         /* Mark socket as an encapsulation socket. See net/ipv4/udp.c */
1563         (udp_sk(sk))->encap_type = UDP_ENCAP_L2TPINUDP;
1564         (udp_sk(sk))->encap_rcv = pppol2tp_udp_encap_recv;
1565
1566         ret = tunnel->sock;
1567
1568         *error = 0;
1569 out:
1570         if (sock)
1571                 sockfd_put(sock);
1572
1573         return ret;
1574
1575 err:
1576         *error = err;
1577         goto out;
1578 }
1579
1580 static struct proto pppol2tp_sk_proto = {
1581         .name     = "PPPOL2TP",
1582         .owner    = THIS_MODULE,
1583         .obj_size = sizeof(struct pppox_sock),
1584 };
1585
1586 /* socket() handler. Initialize a new struct sock.
1587  */
1588 static int pppol2tp_create(struct net *net, struct socket *sock)
1589 {
1590         int error = -ENOMEM;
1591         struct sock *sk;
1592
1593         sk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, &pppol2tp_sk_proto);
1594         if (!sk)
1595                 goto out;
1596
1597         sock_init_data(sock, sk);
1598
1599         sock->state  = SS_UNCONNECTED;
1600         sock->ops    = &pppol2tp_ops;
1601
1602         sk->sk_backlog_rcv = pppol2tp_recv_core;
1603         sk->sk_protocol    = PX_PROTO_OL2TP;
1604         sk->sk_family      = PF_PPPOX;
1605         sk->sk_state       = PPPOX_NONE;
1606         sk->sk_type        = SOCK_STREAM;
1607         sk->sk_destruct    = pppol2tp_session_destruct;
1608
1609         error = 0;
1610
1611 out:
1612         return error;
1613 }
1614
1615 /* connect() handler. Attach a PPPoX socket to a tunnel UDP socket
1616  */
1617 static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr,
1618                             int sockaddr_len, int flags)
1619 {
1620         struct sock *sk = sock->sk;
1621         struct sockaddr_pppol2tp *sp = (struct sockaddr_pppol2tp *) uservaddr;
1622         struct pppox_sock *po = pppox_sk(sk);
1623         struct sock *tunnel_sock = NULL;
1624         struct pppol2tp_session *session = NULL;
1625         struct pppol2tp_tunnel *tunnel;
1626         struct dst_entry *dst;
1627         int error = 0;
1628
1629         lock_sock(sk);
1630
1631         error = -EINVAL;
1632         if (sp->sa_protocol != PX_PROTO_OL2TP)
1633                 goto end;
1634
1635         /* Check for already bound sockets */
1636         error = -EBUSY;
1637         if (sk->sk_state & PPPOX_CONNECTED)
1638                 goto end;
1639
1640         /* We don't supporting rebinding anyway */
1641         error = -EALREADY;
1642         if (sk->sk_user_data)
1643                 goto end; /* socket is already attached */
1644
1645         /* Don't bind if s_tunnel is 0 */
1646         error = -EINVAL;
1647         if (sp->pppol2tp.s_tunnel == 0)
1648                 goto end;
1649
1650         /* Special case: prepare tunnel socket if s_session and
1651          * d_session is 0. Otherwise look up tunnel using supplied
1652          * tunnel id.
1653          */
1654         if ((sp->pppol2tp.s_session == 0) && (sp->pppol2tp.d_session == 0)) {
1655                 tunnel_sock = pppol2tp_prepare_tunnel_socket(sock_net(sk),
1656                                                              sp->pppol2tp.fd,
1657                                                              sp->pppol2tp.s_tunnel,
1658                                                              &error);
1659                 if (tunnel_sock == NULL)
1660                         goto end;
1661
1662                 tunnel = tunnel_sock->sk_user_data;
1663         } else {
1664                 tunnel = pppol2tp_tunnel_find(sock_net(sk), sp->pppol2tp.s_tunnel);
1665
1666                 /* Error if we can't find the tunnel */
1667                 error = -ENOENT;
1668                 if (tunnel == NULL)
1669                         goto end;
1670
1671                 tunnel_sock = tunnel->sock;
1672         }
1673
1674         /* Check that this session doesn't already exist */
1675         error = -EEXIST;
1676         session = pppol2tp_session_find(tunnel, sp->pppol2tp.s_session);
1677         if (session != NULL)
1678                 goto end;
1679
1680         /* Allocate and initialize a new session context. */
1681         session = kzalloc(sizeof(struct pppol2tp_session), GFP_KERNEL);
1682         if (session == NULL) {
1683                 error = -ENOMEM;
1684                 goto end;
1685         }
1686
1687         skb_queue_head_init(&session->reorder_q);
1688
1689         session->magic       = L2TP_SESSION_MAGIC;
1690         session->owner       = current->pid;
1691         session->sock        = sk;
1692         session->tunnel      = tunnel;
1693         session->tunnel_sock = tunnel_sock;
1694         session->tunnel_addr = sp->pppol2tp;
1695         sprintf(&session->name[0], "sess %hu/%hu",
1696                 session->tunnel_addr.s_tunnel,
1697                 session->tunnel_addr.s_session);
1698
1699         session->stats.tunnel_id  = session->tunnel_addr.s_tunnel;
1700         session->stats.session_id = session->tunnel_addr.s_session;
1701
1702         INIT_HLIST_NODE(&session->hlist);
1703
1704         /* Inherit debug options from tunnel */
1705         session->debug = tunnel->debug;
1706
1707         /* Default MTU must allow space for UDP/L2TP/PPP
1708          * headers.
1709          */
1710         session->mtu = session->mru = 1500 - PPPOL2TP_HEADER_OVERHEAD;
1711
1712         /* If PMTU discovery was enabled, use the MTU that was discovered */
1713         dst = sk_dst_get(sk);
1714         if (dst != NULL) {
1715                 u32 pmtu = dst_mtu(__sk_dst_get(sk));
1716                 if (pmtu != 0)
1717                         session->mtu = session->mru = pmtu -
1718                                 PPPOL2TP_HEADER_OVERHEAD;
1719                 dst_release(dst);
1720         }
1721
1722         /* Special case: if source & dest session_id == 0x0000, this socket is
1723          * being created to manage the tunnel. Don't add the session to the
1724          * session hash list, just set up the internal context for use by
1725          * ioctl() and sockopt() handlers.
1726          */
1727         if ((session->tunnel_addr.s_session == 0) &&
1728             (session->tunnel_addr.d_session == 0)) {
1729                 error = 0;
1730                 sk->sk_user_data = session;
1731                 goto out_no_ppp;
1732         }
1733
1734         /* Get tunnel context from the tunnel socket */
1735         tunnel = pppol2tp_sock_to_tunnel(tunnel_sock);
1736         if (tunnel == NULL) {
1737                 error = -EBADF;
1738                 goto end;
1739         }
1740
1741         /* Right now, because we don't have a way to push the incoming skb's
1742          * straight through the UDP layer, the only header we need to worry
1743          * about is the L2TP header. This size is different depending on
1744          * whether sequence numbers are enabled for the data channel.
1745          */
1746         po->chan.hdrlen = PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
1747
1748         po->chan.private = sk;
1749         po->chan.ops     = &pppol2tp_chan_ops;
1750         po->chan.mtu     = session->mtu;
1751
1752         error = ppp_register_net_channel(sock_net(sk), &po->chan);
1753         if (error)
1754                 goto end_put_tun;
1755
1756         /* This is how we get the session context from the socket. */
1757         sk->sk_user_data = session;
1758
1759         /* Add session to the tunnel's hash list */
1760         write_lock_bh(&tunnel->hlist_lock);
1761         hlist_add_head(&session->hlist,
1762                        pppol2tp_session_id_hash(tunnel,
1763                                                 session->tunnel_addr.s_session));
1764         write_unlock_bh(&tunnel->hlist_lock);
1765
1766         atomic_inc(&pppol2tp_session_count);
1767
1768 out_no_ppp:
1769         pppol2tp_tunnel_inc_refcount(tunnel);
1770         sk->sk_state = PPPOX_CONNECTED;
1771         PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1772                "%s: created\n", session->name);
1773
1774 end_put_tun:
1775         sock_put(tunnel_sock);
1776 end:
1777         release_sock(sk);
1778
1779         if (error != 0) {
1780                 if (session)
1781                         PRINTK(session->debug,
1782                                 PPPOL2TP_MSG_CONTROL, KERN_WARNING,
1783                                 "%s: connect failed: %d\n",
1784                                 session->name, error);
1785                 else
1786                         PRINTK(-1, PPPOL2TP_MSG_CONTROL, KERN_WARNING,
1787                                 "connect failed: %d\n", error);
1788         }
1789
1790         return error;
1791 }
1792
1793 /* getname() support.
1794  */
1795 static int pppol2tp_getname(struct socket *sock, struct sockaddr *uaddr,
1796                             int *usockaddr_len, int peer)
1797 {
1798         int len = sizeof(struct sockaddr_pppol2tp);
1799         struct sockaddr_pppol2tp sp;
1800         int error = 0;
1801         struct pppol2tp_session *session;
1802
1803         error = -ENOTCONN;
1804         if (sock->sk->sk_state != PPPOX_CONNECTED)
1805                 goto end;
1806
1807         session = pppol2tp_sock_to_session(sock->sk);
1808         if (session == NULL) {
1809                 error = -EBADF;
1810                 goto end;
1811         }
1812
1813         sp.sa_family    = AF_PPPOX;
1814         sp.sa_protocol  = PX_PROTO_OL2TP;
1815         memcpy(&sp.pppol2tp, &session->tunnel_addr,
1816                sizeof(struct pppol2tp_addr));
1817
1818         memcpy(uaddr, &sp, len);
1819
1820         *usockaddr_len = len;
1821
1822         error = 0;
1823         sock_put(sock->sk);
1824
1825 end:
1826         return error;
1827 }
1828
1829 /****************************************************************************
1830  * ioctl() handlers.
1831  *
1832  * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
1833  * sockets. However, in order to control kernel tunnel features, we allow
1834  * userspace to create a special "tunnel" PPPoX socket which is used for
1835  * control only.  Tunnel PPPoX sockets have session_id == 0 and simply allow
1836  * the user application to issue L2TP setsockopt(), getsockopt() and ioctl()
1837  * calls.
1838  ****************************************************************************/
1839
1840 /* Session ioctl helper.
1841  */
1842 static int pppol2tp_session_ioctl(struct pppol2tp_session *session,
1843                                   unsigned int cmd, unsigned long arg)
1844 {
1845         struct ifreq ifr;
1846         int err = 0;
1847         struct sock *sk = session->sock;
1848         int val = (int) arg;
1849
1850         PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_DEBUG,
1851                "%s: pppol2tp_session_ioctl(cmd=%#x, arg=%#lx)\n",
1852                session->name, cmd, arg);
1853
1854         sock_hold(sk);
1855
1856         switch (cmd) {
1857         case SIOCGIFMTU:
1858                 err = -ENXIO;
1859                 if (!(sk->sk_state & PPPOX_CONNECTED))
1860                         break;
1861
1862                 err = -EFAULT;
1863                 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq)))
1864                         break;
1865                 ifr.ifr_mtu = session->mtu;
1866                 if (copy_to_user((void __user *) arg, &ifr, sizeof(struct ifreq)))
1867                         break;
1868
1869                 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1870                        "%s: get mtu=%d\n", session->name, session->mtu);
1871                 err = 0;
1872                 break;
1873
1874         case SIOCSIFMTU:
1875                 err = -ENXIO;
1876                 if (!(sk->sk_state & PPPOX_CONNECTED))
1877                         break;
1878
1879                 err = -EFAULT;
1880                 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq)))
1881                         break;
1882
1883                 session->mtu = ifr.ifr_mtu;
1884
1885                 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1886                        "%s: set mtu=%d\n", session->name, session->mtu);
1887                 err = 0;
1888                 break;
1889
1890         case PPPIOCGMRU:
1891                 err = -ENXIO;
1892                 if (!(sk->sk_state & PPPOX_CONNECTED))
1893                         break;
1894
1895                 err = -EFAULT;
1896                 if (put_user(session->mru, (int __user *) arg))
1897                         break;
1898
1899                 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1900                        "%s: get mru=%d\n", session->name, session->mru);
1901                 err = 0;
1902                 break;
1903
1904         case PPPIOCSMRU:
1905                 err = -ENXIO;
1906                 if (!(sk->sk_state & PPPOX_CONNECTED))
1907                         break;
1908
1909                 err = -EFAULT;
1910                 if (get_user(val,(int __user *) arg))
1911                         break;
1912
1913                 session->mru = val;
1914                 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1915                        "%s: set mru=%d\n", session->name, session->mru);
1916                 err = 0;
1917                 break;
1918
1919         case PPPIOCGFLAGS:
1920                 err = -EFAULT;
1921                 if (put_user(session->flags, (int __user *) arg))
1922                         break;
1923
1924                 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1925                        "%s: get flags=%d\n", session->name, session->flags);
1926                 err = 0;
1927                 break;
1928
1929         case PPPIOCSFLAGS:
1930                 err = -EFAULT;
1931                 if (get_user(val, (int __user *) arg))
1932                         break;
1933                 session->flags = val;
1934                 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1935                        "%s: set flags=%d\n", session->name, session->flags);
1936                 err = 0;
1937                 break;
1938
1939         case PPPIOCGL2TPSTATS:
1940                 err = -ENXIO;
1941                 if (!(sk->sk_state & PPPOX_CONNECTED))
1942                         break;
1943
1944                 if (copy_to_user((void __user *) arg, &session->stats,
1945                                  sizeof(session->stats)))
1946                         break;
1947                 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1948                        "%s: get L2TP stats\n", session->name);
1949                 err = 0;
1950                 break;
1951
1952         default:
1953                 err = -ENOSYS;
1954                 break;
1955         }
1956
1957         sock_put(sk);
1958
1959         return err;
1960 }
1961
1962 /* Tunnel ioctl helper.
1963  *
1964  * Note the special handling for PPPIOCGL2TPSTATS below. If the ioctl data
1965  * specifies a session_id, the session ioctl handler is called. This allows an
1966  * application to retrieve session stats via a tunnel socket.
1967  */
1968 static int pppol2tp_tunnel_ioctl(struct pppol2tp_tunnel *tunnel,
1969                                  unsigned int cmd, unsigned long arg)
1970 {
1971         int err = 0;
1972         struct sock *sk = tunnel->sock;
1973         struct pppol2tp_ioc_stats stats_req;
1974
1975         PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_DEBUG,
1976                "%s: pppol2tp_tunnel_ioctl(cmd=%#x, arg=%#lx)\n", tunnel->name,
1977                cmd, arg);
1978
1979         sock_hold(sk);
1980
1981         switch (cmd) {
1982         case PPPIOCGL2TPSTATS:
1983                 err = -ENXIO;
1984                 if (!(sk->sk_state & PPPOX_CONNECTED))
1985                         break;
1986
1987                 if (copy_from_user(&stats_req, (void __user *) arg,
1988                                    sizeof(stats_req))) {
1989                         err = -EFAULT;
1990                         break;
1991                 }
1992                 if (stats_req.session_id != 0) {
1993                         /* resend to session ioctl handler */
1994                         struct pppol2tp_session *session =
1995                                 pppol2tp_session_find(tunnel, stats_req.session_id);
1996                         if (session != NULL)
1997                                 err = pppol2tp_session_ioctl(session, cmd, arg);
1998                         else
1999                                 err = -EBADR;
2000                         break;
2001                 }
2002 #ifdef CONFIG_XFRM
2003                 tunnel->stats.using_ipsec = (sk->sk_policy[0] || sk->sk_policy[1]) ? 1 : 0;
2004 #endif
2005                 if (copy_to_user((void __user *) arg, &tunnel->stats,
2006                                  sizeof(tunnel->stats))) {
2007                         err = -EFAULT;
2008                         break;
2009                 }
2010                 PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2011                        "%s: get L2TP stats\n", tunnel->name);
2012                 err = 0;
2013                 break;
2014
2015         default:
2016                 err = -ENOSYS;
2017                 break;
2018         }
2019
2020         sock_put(sk);
2021
2022         return err;
2023 }
2024
2025 /* Main ioctl() handler.
2026  * Dispatch to tunnel or session helpers depending on the socket.
2027  */
2028 static int pppol2tp_ioctl(struct socket *sock, unsigned int cmd,
2029                           unsigned long arg)
2030 {
2031         struct sock *sk = sock->sk;
2032         struct pppol2tp_session *session;
2033         struct pppol2tp_tunnel *tunnel;
2034         int err;
2035
2036         if (!sk)
2037                 return 0;
2038
2039         err = -EBADF;
2040         if (sock_flag(sk, SOCK_DEAD) != 0)
2041                 goto end;
2042
2043         err = -ENOTCONN;
2044         if ((sk->sk_user_data == NULL) ||
2045             (!(sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND))))
2046                 goto end;
2047
2048         /* Get session context from the socket */
2049         err = -EBADF;
2050         session = pppol2tp_sock_to_session(sk);
2051         if (session == NULL)
2052                 goto end;
2053
2054         /* Special case: if session's session_id is zero, treat ioctl as a
2055          * tunnel ioctl
2056          */
2057         if ((session->tunnel_addr.s_session == 0) &&
2058             (session->tunnel_addr.d_session == 0)) {
2059                 err = -EBADF;
2060                 tunnel = pppol2tp_sock_to_tunnel(session->tunnel_sock);
2061                 if (tunnel == NULL)
2062                         goto end_put_sess;
2063
2064                 err = pppol2tp_tunnel_ioctl(tunnel, cmd, arg);
2065                 sock_put(session->tunnel_sock);
2066                 goto end_put_sess;
2067         }
2068
2069         err = pppol2tp_session_ioctl(session, cmd, arg);
2070
2071 end_put_sess:
2072         sock_put(sk);
2073 end:
2074         return err;
2075 }
2076
2077 /*****************************************************************************
2078  * setsockopt() / getsockopt() support.
2079  *
2080  * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
2081  * sockets. In order to control kernel tunnel features, we allow userspace to
2082  * create a special "tunnel" PPPoX socket which is used for control only.
2083  * Tunnel PPPoX sockets have session_id == 0 and simply allow the user
2084  * application to issue L2TP setsockopt(), getsockopt() and ioctl() calls.
2085  *****************************************************************************/
2086
2087 /* Tunnel setsockopt() helper.
2088  */
2089 static int pppol2tp_tunnel_setsockopt(struct sock *sk,
2090                                       struct pppol2tp_tunnel *tunnel,
2091                                       int optname, int val)
2092 {
2093         int err = 0;
2094
2095         switch (optname) {
2096         case PPPOL2TP_SO_DEBUG:
2097                 tunnel->debug = val;
2098                 PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2099                        "%s: set debug=%x\n", tunnel->name, tunnel->debug);
2100                 break;
2101
2102         default:
2103                 err = -ENOPROTOOPT;
2104                 break;
2105         }
2106
2107         return err;
2108 }
2109
2110 /* Session setsockopt helper.
2111  */
2112 static int pppol2tp_session_setsockopt(struct sock *sk,
2113                                        struct pppol2tp_session *session,
2114                                        int optname, int val)
2115 {
2116         int err = 0;
2117
2118         switch (optname) {
2119         case PPPOL2TP_SO_RECVSEQ:
2120                 if ((val != 0) && (val != 1)) {
2121                         err = -EINVAL;
2122                         break;
2123                 }
2124                 session->recv_seq = val ? -1 : 0;
2125                 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2126                        "%s: set recv_seq=%d\n", session->name,
2127                        session->recv_seq);
2128                 break;
2129
2130         case PPPOL2TP_SO_SENDSEQ:
2131                 if ((val != 0) && (val != 1)) {
2132                         err = -EINVAL;
2133                         break;
2134                 }
2135                 session->send_seq = val ? -1 : 0;
2136                 {
2137                         struct sock *ssk      = session->sock;
2138                         struct pppox_sock *po = pppox_sk(ssk);
2139                         po->chan.hdrlen = val ? PPPOL2TP_L2TP_HDR_SIZE_SEQ :
2140                                 PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
2141                 }
2142                 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2143                        "%s: set send_seq=%d\n", session->name, session->send_seq);
2144                 break;
2145
2146         case PPPOL2TP_SO_LNSMODE:
2147                 if ((val != 0) && (val != 1)) {
2148                         err = -EINVAL;
2149                         break;
2150                 }
2151                 session->lns_mode = val ? -1 : 0;
2152                 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2153                        "%s: set lns_mode=%d\n", session->name,
2154                        session->lns_mode);
2155                 break;
2156
2157         case PPPOL2TP_SO_DEBUG:
2158                 session->debug = val;
2159                 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2160                        "%s: set debug=%x\n", session->name, session->debug);
2161                 break;
2162
2163         case PPPOL2TP_SO_REORDERTO:
2164                 session->reorder_timeout = msecs_to_jiffies(val);
2165                 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2166                        "%s: set reorder_timeout=%d\n", session->name,
2167                        session->reorder_timeout);
2168                 break;
2169
2170         default:
2171                 err = -ENOPROTOOPT;
2172                 break;
2173         }
2174
2175         return err;
2176 }
2177
2178 /* Main setsockopt() entry point.
2179  * Does API checks, then calls either the tunnel or session setsockopt
2180  * handler, according to whether the PPPoL2TP socket is a for a regular
2181  * session or the special tunnel type.
2182  */
2183 static int pppol2tp_setsockopt(struct socket *sock, int level, int optname,
2184                                char __user *optval, int optlen)
2185 {
2186         struct sock *sk = sock->sk;
2187         struct pppol2tp_session *session = sk->sk_user_data;
2188         struct pppol2tp_tunnel *tunnel;
2189         int val;
2190         int err;
2191
2192         if (level != SOL_PPPOL2TP)
2193                 return udp_prot.setsockopt(sk, level, optname, optval, optlen);
2194
2195         if (optlen < sizeof(int))
2196                 return -EINVAL;
2197
2198         if (get_user(val, (int __user *)optval))
2199                 return -EFAULT;
2200
2201         err = -ENOTCONN;
2202         if (sk->sk_user_data == NULL)
2203                 goto end;
2204
2205         /* Get session context from the socket */
2206         err = -EBADF;
2207         session = pppol2tp_sock_to_session(sk);
2208         if (session == NULL)
2209                 goto end;
2210
2211         /* Special case: if session_id == 0x0000, treat as operation on tunnel
2212          */
2213         if ((session->tunnel_addr.s_session == 0) &&
2214             (session->tunnel_addr.d_session == 0)) {
2215                 err = -EBADF;
2216                 tunnel = pppol2tp_sock_to_tunnel(session->tunnel_sock);
2217                 if (tunnel == NULL)
2218                         goto end_put_sess;
2219
2220                 err = pppol2tp_tunnel_setsockopt(sk, tunnel, optname, val);
2221                 sock_put(session->tunnel_sock);
2222         } else
2223                 err = pppol2tp_session_setsockopt(sk, session, optname, val);
2224
2225         err = 0;
2226
2227 end_put_sess:
2228         sock_put(sk);
2229 end:
2230         return err;
2231 }
2232
2233 /* Tunnel getsockopt helper. Called with sock locked.
2234  */
2235 static int pppol2tp_tunnel_getsockopt(struct sock *sk,
2236                                       struct pppol2tp_tunnel *tunnel,
2237                                       int optname, int *val)
2238 {
2239         int err = 0;
2240
2241         switch (optname) {
2242         case PPPOL2TP_SO_DEBUG:
2243                 *val = tunnel->debug;
2244                 PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2245                        "%s: get debug=%x\n", tunnel->name, tunnel->debug);
2246                 break;
2247
2248         default:
2249                 err = -ENOPROTOOPT;
2250                 break;
2251         }
2252
2253         return err;
2254 }
2255
2256 /* Session getsockopt helper. Called with sock locked.
2257  */
2258 static int pppol2tp_session_getsockopt(struct sock *sk,
2259                                        struct pppol2tp_session *session,
2260                                        int optname, int *val)
2261 {
2262         int err = 0;
2263
2264         switch (optname) {
2265         case PPPOL2TP_SO_RECVSEQ:
2266                 *val = session->recv_seq;
2267                 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2268                        "%s: get recv_seq=%d\n", session->name, *val);
2269                 break;
2270
2271         case PPPOL2TP_SO_SENDSEQ:
2272                 *val = session->send_seq;
2273                 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2274                        "%s: get send_seq=%d\n", session->name, *val);
2275                 break;
2276
2277         case PPPOL2TP_SO_LNSMODE:
2278                 *val = session->lns_mode;
2279                 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2280                        "%s: get lns_mode=%d\n", session->name, *val);
2281                 break;
2282
2283         case PPPOL2TP_SO_DEBUG:
2284                 *val = session->debug;
2285                 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2286                        "%s: get debug=%d\n", session->name, *val);
2287                 break;
2288
2289         case PPPOL2TP_SO_REORDERTO:
2290                 *val = (int) jiffies_to_msecs(session->reorder_timeout);
2291                 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2292                        "%s: get reorder_timeout=%d\n", session->name, *val);
2293                 break;
2294
2295         default:
2296                 err = -ENOPROTOOPT;
2297         }
2298
2299         return err;
2300 }
2301
2302 /* Main getsockopt() entry point.
2303  * Does API checks, then calls either the tunnel or session getsockopt
2304  * handler, according to whether the PPPoX socket is a for a regular session
2305  * or the special tunnel type.
2306  */
2307 static int pppol2tp_getsockopt(struct socket *sock, int level,
2308                                int optname, char __user *optval, int __user *optlen)
2309 {
2310         struct sock *sk = sock->sk;
2311         struct pppol2tp_session *session = sk->sk_user_data;
2312         struct pppol2tp_tunnel *tunnel;
2313         int val, len;
2314         int err;
2315
2316         if (level != SOL_PPPOL2TP)
2317                 return udp_prot.getsockopt(sk, level, optname, optval, optlen);
2318
2319         if (get_user(len, (int __user *) optlen))
2320                 return -EFAULT;
2321
2322         len = min_t(unsigned int, len, sizeof(int));
2323
2324         if (len < 0)
2325                 return -EINVAL;
2326
2327         err = -ENOTCONN;
2328         if (sk->sk_user_data == NULL)
2329                 goto end;
2330
2331         /* Get the session context */
2332         err = -EBADF;
2333         session = pppol2tp_sock_to_session(sk);
2334         if (session == NULL)
2335                 goto end;
2336
2337         /* Special case: if session_id == 0x0000, treat as operation on tunnel */
2338         if ((session->tunnel_addr.s_session == 0) &&
2339             (session->tunnel_addr.d_session == 0)) {
2340                 err = -EBADF;
2341                 tunnel = pppol2tp_sock_to_tunnel(session->tunnel_sock);
2342                 if (tunnel == NULL)
2343                         goto end_put_sess;
2344
2345                 err = pppol2tp_tunnel_getsockopt(sk, tunnel, optname, &val);
2346                 sock_put(session->tunnel_sock);
2347         } else
2348                 err = pppol2tp_session_getsockopt(sk, session, optname, &val);
2349
2350         err = -EFAULT;
2351         if (put_user(len, (int __user *) optlen))
2352                 goto end_put_sess;
2353
2354         if (copy_to_user((void __user *) optval, &val, len))
2355                 goto end_put_sess;
2356
2357         err = 0;
2358
2359 end_put_sess:
2360         sock_put(sk);
2361 end:
2362         return err;
2363 }
2364
2365 /*****************************************************************************
2366  * /proc filesystem for debug
2367  *****************************************************************************/
2368
2369 #ifdef CONFIG_PROC_FS
2370
2371 #include <linux/seq_file.h>
2372
2373 struct pppol2tp_seq_data {
2374         struct seq_net_private p;
2375         struct pppol2tp_tunnel *tunnel;         /* current tunnel */
2376         struct pppol2tp_session *session;       /* NULL means get first session in tunnel */
2377 };
2378
2379 static struct pppol2tp_session *next_session(struct pppol2tp_tunnel *tunnel, struct pppol2tp_session *curr)
2380 {
2381         struct pppol2tp_session *session = NULL;
2382         struct hlist_node *walk;
2383         int found = 0;
2384         int next = 0;
2385         int i;
2386
2387         read_lock_bh(&tunnel->hlist_lock);
2388         for (i = 0; i < PPPOL2TP_HASH_SIZE; i++) {
2389                 hlist_for_each_entry(session, walk, &tunnel->session_hlist[i], hlist) {
2390                         if (curr == NULL) {
2391                                 found = 1;
2392                                 goto out;
2393                         }
2394                         if (session == curr) {
2395                                 next = 1;
2396                                 continue;
2397                         }
2398                         if (next) {
2399                                 found = 1;
2400                                 goto out;
2401                         }
2402                 }
2403         }
2404 out:
2405         read_unlock_bh(&tunnel->hlist_lock);
2406         if (!found)
2407                 session = NULL;
2408
2409         return session;
2410 }
2411
2412 static struct pppol2tp_tunnel *next_tunnel(struct pppol2tp_net *pn,
2413                                            struct pppol2tp_tunnel *curr)
2414 {
2415         struct pppol2tp_tunnel *tunnel = NULL;
2416
2417         read_lock_bh(&pn->pppol2tp_tunnel_list_lock);
2418         if (list_is_last(&curr->list, &pn->pppol2tp_tunnel_list)) {
2419                 goto out;
2420         }
2421         tunnel = list_entry(curr->list.next, struct pppol2tp_tunnel, list);
2422 out:
2423         read_unlock_bh(&pn->pppol2tp_tunnel_list_lock);
2424
2425         return tunnel;
2426 }
2427
2428 static void *pppol2tp_seq_start(struct seq_file *m, loff_t *offs)
2429 {
2430         struct pppol2tp_seq_data *pd = SEQ_START_TOKEN;
2431         struct pppol2tp_net *pn;
2432         loff_t pos = *offs;
2433
2434         if (!pos)
2435                 goto out;
2436
2437         BUG_ON(m->private == NULL);
2438         pd = m->private;
2439         pn = pppol2tp_pernet(seq_file_net(m));
2440
2441         if (pd->tunnel == NULL) {
2442                 if (!list_empty(&pn->pppol2tp_tunnel_list))
2443                         pd->tunnel = list_entry(pn->pppol2tp_tunnel_list.next, struct pppol2tp_tunnel, list);
2444         } else {
2445                 pd->session = next_session(pd->tunnel, pd->session);
2446                 if (pd->session == NULL) {
2447                         pd->tunnel = next_tunnel(pn, pd->tunnel);
2448                 }
2449         }
2450
2451         /* NULL tunnel and session indicates end of list */
2452         if ((pd->tunnel == NULL) && (pd->session == NULL))
2453                 pd = NULL;
2454
2455 out:
2456         return pd;
2457 }
2458
2459 static void *pppol2tp_seq_next(struct seq_file *m, void *v, loff_t *pos)
2460 {
2461         (*pos)++;
2462         return NULL;
2463 }
2464
2465 static void pppol2tp_seq_stop(struct seq_file *p, void *v)
2466 {
2467         /* nothing to do */
2468 }
2469
2470 static void pppol2tp_seq_tunnel_show(struct seq_file *m, void *v)
2471 {
2472         struct pppol2tp_tunnel *tunnel = v;
2473
2474         seq_printf(m, "\nTUNNEL '%s', %c %d\n",
2475                    tunnel->name,
2476                    (tunnel == tunnel->sock->sk_user_data) ? 'Y':'N',
2477                    atomic_read(&tunnel->ref_count) - 1);
2478         seq_printf(m, " %08x %llu/%llu/%llu %llu/%llu/%llu\n",
2479                    tunnel->debug,
2480                    (unsigned long long)tunnel->stats.tx_packets,
2481                    (unsigned long long)tunnel->stats.tx_bytes,
2482                    (unsigned long long)tunnel->stats.tx_errors,
2483                    (unsigned long long)tunnel->stats.rx_packets,
2484                    (unsigned long long)tunnel->stats.rx_bytes,
2485                    (unsigned long long)tunnel->stats.rx_errors);
2486 }
2487
2488 static void pppol2tp_seq_session_show(struct seq_file *m, void *v)
2489 {
2490         struct pppol2tp_session *session = v;
2491
2492         seq_printf(m, "  SESSION '%s' %08X/%d %04X/%04X -> "
2493                    "%04X/%04X %d %c\n",
2494                    session->name,
2495                    ntohl(session->tunnel_addr.addr.sin_addr.s_addr),
2496                    ntohs(session->tunnel_addr.addr.sin_port),
2497                    session->tunnel_addr.s_tunnel,
2498                    session->tunnel_addr.s_session,
2499                    session->tunnel_addr.d_tunnel,
2500                    session->tunnel_addr.d_session,
2501                    session->sock->sk_state,
2502                    (session == session->sock->sk_user_data) ?
2503                    'Y' : 'N');
2504         seq_printf(m, "   %d/%d/%c/%c/%s %08x %u\n",
2505                    session->mtu, session->mru,
2506                    session->recv_seq ? 'R' : '-',
2507                    session->send_seq ? 'S' : '-',
2508                    session->lns_mode ? "LNS" : "LAC",
2509                    session->debug,
2510                    jiffies_to_msecs(session->reorder_timeout));
2511         seq_printf(m, "   %hu/%hu %llu/%llu/%llu %llu/%llu/%llu\n",
2512                    session->nr, session->ns,
2513                    (unsigned long long)session->stats.tx_packets,
2514                    (unsigned long long)session->stats.tx_bytes,
2515                    (unsigned long long)session->stats.tx_errors,
2516                    (unsigned long long)session->stats.rx_packets,
2517                    (unsigned long long)session->stats.rx_bytes,
2518                    (unsigned long long)session->stats.rx_errors);
2519 }
2520
2521 static int pppol2tp_seq_show(struct seq_file *m, void *v)
2522 {
2523         struct pppol2tp_seq_data *pd = v;
2524
2525         /* display header on line 1 */
2526         if (v == SEQ_START_TOKEN) {
2527                 seq_puts(m, "PPPoL2TP driver info, " PPPOL2TP_DRV_VERSION "\n");
2528                 seq_puts(m, "TUNNEL name, user-data-ok session-count\n");
2529                 seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
2530                 seq_puts(m, "  SESSION name, addr/port src-tid/sid "
2531                          "dest-tid/sid state user-data-ok\n");
2532                 seq_puts(m, "   mtu/mru/rcvseq/sendseq/lns debug reorderto\n");
2533                 seq_puts(m, "   nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
2534                 goto out;
2535         }
2536
2537         /* Show the tunnel or session context.
2538          */
2539         if (pd->session == NULL)
2540                 pppol2tp_seq_tunnel_show(m, pd->tunnel);
2541         else
2542                 pppol2tp_seq_session_show(m, pd->session);
2543
2544 out:
2545         return 0;
2546 }
2547
2548 static const struct seq_operations pppol2tp_seq_ops = {
2549         .start          = pppol2tp_seq_start,
2550         .next           = pppol2tp_seq_next,
2551         .stop           = pppol2tp_seq_stop,
2552         .show           = pppol2tp_seq_show,
2553 };
2554
2555 /* Called when our /proc file is opened. We allocate data for use when
2556  * iterating our tunnel / session contexts and store it in the private
2557  * data of the seq_file.
2558  */
2559 static int pppol2tp_proc_open(struct inode *inode, struct file *file)
2560 {
2561         return seq_open_net(inode, file, &pppol2tp_seq_ops,
2562                             sizeof(struct pppol2tp_seq_data));
2563 }
2564
2565 static const struct file_operations pppol2tp_proc_fops = {
2566         .owner          = THIS_MODULE,
2567         .open           = pppol2tp_proc_open,
2568         .read           = seq_read,
2569         .llseek         = seq_lseek,
2570         .release        = seq_release_net,
2571 };
2572
2573 #endif /* CONFIG_PROC_FS */
2574
2575 /*****************************************************************************
2576  * Init and cleanup
2577  *****************************************************************************/
2578
2579 static struct proto_ops pppol2tp_ops = {
2580         .family         = AF_PPPOX,
2581         .owner          = THIS_MODULE,
2582         .release        = pppol2tp_release,
2583         .bind           = sock_no_bind,
2584         .connect        = pppol2tp_connect,
2585         .socketpair     = sock_no_socketpair,
2586         .accept         = sock_no_accept,
2587         .getname        = pppol2tp_getname,
2588         .poll           = datagram_poll,
2589         .listen         = sock_no_listen,
2590         .shutdown       = sock_no_shutdown,
2591         .setsockopt     = pppol2tp_setsockopt,
2592         .getsockopt     = pppol2tp_getsockopt,
2593         .sendmsg        = pppol2tp_sendmsg,
2594         .recvmsg        = pppol2tp_recvmsg,
2595         .mmap           = sock_no_mmap,
2596         .ioctl          = pppox_ioctl,
2597 };
2598
2599 static struct pppox_proto pppol2tp_proto = {
2600         .create         = pppol2tp_create,
2601         .ioctl          = pppol2tp_ioctl
2602 };
2603
2604 static __net_init int pppol2tp_init_net(struct net *net)
2605 {
2606         struct pppol2tp_net *pn;
2607         struct proc_dir_entry *pde;
2608         int err;
2609
2610         pn = kzalloc(sizeof(*pn), GFP_KERNEL);
2611         if (!pn)
2612                 return -ENOMEM;
2613
2614         INIT_LIST_HEAD(&pn->pppol2tp_tunnel_list);
2615         rwlock_init(&pn->pppol2tp_tunnel_list_lock);
2616
2617         err = net_assign_generic(net, pppol2tp_net_id, pn);
2618         if (err)
2619                 goto out;
2620
2621         pde = proc_net_fops_create(net, "pppol2tp", S_IRUGO, &pppol2tp_proc_fops);
2622 #ifdef CONFIG_PROC_FS
2623         if (!pde) {
2624                 err = -ENOMEM;
2625                 goto out;
2626         }
2627 #endif
2628
2629         return 0;
2630
2631 out:
2632         kfree(pn);
2633         return err;
2634 }
2635
2636 static __net_exit void pppol2tp_exit_net(struct net *net)
2637 {
2638         struct pppoe_net *pn;
2639
2640         proc_net_remove(net, "pppol2tp");
2641         pn = net_generic(net, pppol2tp_net_id);
2642         /*
2643          * if someone has cached our net then
2644          * further net_generic call will return NULL
2645          */
2646         net_assign_generic(net, pppol2tp_net_id, NULL);
2647         kfree(pn);
2648 }
2649
2650 static struct pernet_operations pppol2tp_net_ops = {
2651         .init = pppol2tp_init_net,
2652         .exit = pppol2tp_exit_net,
2653 };
2654
2655 static int __init pppol2tp_init(void)
2656 {
2657         int err;
2658
2659         err = proto_register(&pppol2tp_sk_proto, 0);
2660         if (err)
2661                 goto out;
2662         err = register_pppox_proto(PX_PROTO_OL2TP, &pppol2tp_proto);
2663         if (err)
2664                 goto out_unregister_pppol2tp_proto;
2665
2666         err = register_pernet_gen_device(&pppol2tp_net_id, &pppol2tp_net_ops);
2667         if (err)
2668                 goto out_unregister_pppox_proto;
2669
2670         printk(KERN_INFO "PPPoL2TP kernel driver, %s\n",
2671                PPPOL2TP_DRV_VERSION);
2672
2673 out:
2674         return err;
2675 out_unregister_pppox_proto:
2676         unregister_pppox_proto(PX_PROTO_OL2TP);
2677 out_unregister_pppol2tp_proto:
2678         proto_unregister(&pppol2tp_sk_proto);
2679         goto out;
2680 }
2681
2682 static void __exit pppol2tp_exit(void)
2683 {
2684         unregister_pppox_proto(PX_PROTO_OL2TP);
2685         proto_unregister(&pppol2tp_sk_proto);
2686 }
2687
2688 module_init(pppol2tp_init);
2689 module_exit(pppol2tp_exit);
2690
2691 MODULE_AUTHOR("Martijn van Oosterhout <kleptog@svana.org>, "
2692               "James Chapman <jchapman@katalix.com>");
2693 MODULE_DESCRIPTION("PPP over L2TP over UDP");
2694 MODULE_LICENSE("GPL");
2695 MODULE_VERSION(PPPOL2TP_DRV_VERSION);