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ia64/kvm: compilation fix. export account_system_vtime.
[pv_ops_mirror.git] / drivers / net / pppol2tp.c
blob79359919335b466d5408e82e33c6d4eae452097e
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/version.h>
65 #include <linux/string.h>
66 #include <linux/list.h>
67 #include <asm/uaccess.h>
68
69 #include <linux/kernel.h>
70 #include <linux/spinlock.h>
71 #include <linux/kthread.h>
72 #include <linux/sched.h>
73 #include <linux/slab.h>
74 #include <linux/errno.h>
75 #include <linux/jiffies.h>
76
77 #include <linux/netdevice.h>
78 #include <linux/net.h>
79 #include <linux/inetdevice.h>
80 #include <linux/skbuff.h>
81 #include <linux/init.h>
82 #include <linux/ip.h>
83 #include <linux/udp.h>
84 #include <linux/if_pppox.h>
85 #include <linux/if_pppol2tp.h>
86 #include <net/sock.h>
87 #include <linux/ppp_channel.h>
88 #include <linux/ppp_defs.h>
89 #include <linux/if_ppp.h>
90 #include <linux/file.h>
91 #include <linux/hash.h>
92 #include <linux/sort.h>
93 #include <linux/proc_fs.h>
94 #include <net/net_namespace.h>
95 #include <net/dst.h>
96 #include <net/ip.h>
97 #include <net/udp.h>
98 #include <net/xfrm.h>
99
100 #include <asm/byteorder.h>
101 #include <asm/atomic.h>
102
103
104 #define PPPOL2TP_DRV_VERSION "V1.0"
105
106 /* L2TP header constants */
107 #define L2TP_HDRFLAG_T 0x8000
108 #define L2TP_HDRFLAG_L 0x4000
109 #define L2TP_HDRFLAG_S 0x0800
110 #define L2TP_HDRFLAG_O 0x0200
111 #define L2TP_HDRFLAG_P 0x0100
112
113 #define L2TP_HDR_VER_MASK 0x000F
114 #define L2TP_HDR_VER 0x0002
115
116 /* Space for UDP, L2TP and PPP headers */
117 #define PPPOL2TP_HEADER_OVERHEAD 40
118
119 /* Just some random numbers */
120 #define L2TP_TUNNEL_MAGIC 0x42114DDA
121 #define L2TP_SESSION_MAGIC 0x0C04EB7D
122
123 #define PPPOL2TP_HASH_BITS 4
124 #define PPPOL2TP_HASH_SIZE (1 << PPPOL2TP_HASH_BITS)
125
126 /* Default trace flags */
127 #define PPPOL2TP_DEFAULT_DEBUG_FLAGS 0
128
129 #define PRINTK(_mask, _type, _lvl, _fmt, args...) \
130 do { \
131 if ((_mask) & (_type)) \
132 printk(_lvl "PPPOL2TP: " _fmt, ##args); \
133 } while(0)
134
135 /* Number of bytes to build transmit L2TP headers.
136 * Unfortunately the size is different depending on whether sequence numbers
137 * are enabled.
138 */
139 #define PPPOL2TP_L2TP_HDR_SIZE_SEQ 10
140 #define PPPOL2TP_L2TP_HDR_SIZE_NOSEQ 6
141
142 struct pppol2tp_tunnel;
143
144 /* Describes a session. It is the sk_user_data field in the PPPoL2TP
145 * socket. Contains information to determine incoming packets and transmit
146 * outgoing ones.
147 */
148 struct pppol2tp_session
149 {
150 int magic; /* should be
151 * L2TP_SESSION_MAGIC */
152 int owner; /* pid that opened the socket */
153
154 struct sock *sock; /* Pointer to the session
155 * PPPoX socket */
156 struct sock *tunnel_sock; /* Pointer to the tunnel UDP
157 * socket */
158
159 struct pppol2tp_addr tunnel_addr; /* Description of tunnel */
160
161 struct pppol2tp_tunnel *tunnel; /* back pointer to tunnel
162 * context */
163
164 char name[20]; /* "sess xxxxx/yyyyy", where
165 * x=tunnel_id, y=session_id */
166 int mtu;
167 int mru;
168 int flags; /* accessed by PPPIOCGFLAGS.
169 * Unused. */
170 unsigned recv_seq:1; /* expect receive packets with
171 * sequence numbers? */
172 unsigned send_seq:1; /* send packets with sequence
173 * numbers? */
174 unsigned lns_mode:1; /* behave as LNS? LAC enables
175 * sequence numbers under
176 * control of LNS. */
177 int debug; /* bitmask of debug message
178 * categories */
179 int reorder_timeout; /* configured reorder timeout
180 * (in jiffies) */
181 u16 nr; /* session NR state (receive) */
182 u16 ns; /* session NR state (send) */
183 struct sk_buff_head reorder_q; /* receive reorder queue */
184 struct pppol2tp_ioc_stats stats;
185 struct hlist_node hlist; /* Hash list node */
186 };
187
188 /* The sk_user_data field of the tunnel's UDP socket. It contains info to track
189 * all the associated sessions so incoming packets can be sorted out
190 */
191 struct pppol2tp_tunnel
192 {
193 int magic; /* Should be L2TP_TUNNEL_MAGIC */
194 rwlock_t hlist_lock; /* protect session_hlist */
195 struct hlist_head session_hlist[PPPOL2TP_HASH_SIZE];
196 /* hashed list of sessions,
197 * hashed by id */
198 int debug; /* bitmask of debug message
199 * categories */
200 char name[12]; /* "tunl xxxxx" */
201 struct pppol2tp_ioc_stats stats;
202
203 void (*old_sk_destruct)(struct sock *);
204
205 struct sock *sock; /* Parent socket */
206 struct list_head list; /* Keep a list of all open
207 * prepared sockets */
208
209 atomic_t ref_count;
210 };
211
212 /* Private data stored for received packets in the skb.
213 */
214 struct pppol2tp_skb_cb {
215 u16 ns;
216 u16 nr;
217 u16 has_seq;
218 u16 length;
219 unsigned long expires;
220 };
221
222 #define PPPOL2TP_SKB_CB(skb) ((struct pppol2tp_skb_cb *) &skb->cb[sizeof(struct inet_skb_parm)])
223
224 static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb);
225 static void pppol2tp_tunnel_free(struct pppol2tp_tunnel *tunnel);
226
227 static atomic_t pppol2tp_tunnel_count;
228 static atomic_t pppol2tp_session_count;
229 static struct ppp_channel_ops pppol2tp_chan_ops = { pppol2tp_xmit , NULL };
230 static struct proto_ops pppol2tp_ops;
231 static LIST_HEAD(pppol2tp_tunnel_list);
232 static DEFINE_RWLOCK(pppol2tp_tunnel_list_lock);
233
234 /* Helpers to obtain tunnel/session contexts from sockets.
235 */
236 static inline struct pppol2tp_session *pppol2tp_sock_to_session(struct sock *sk)
237 {
238 struct pppol2tp_session *session;
239
240 if (sk == NULL)
241 return NULL;
242
243 session = (struct pppol2tp_session *)(sk->sk_user_data);
244 if (session == NULL)
245 return NULL;
246
247 BUG_ON(session->magic != L2TP_SESSION_MAGIC);
248
249 return session;
250 }
251
252 static inline struct pppol2tp_tunnel *pppol2tp_sock_to_tunnel(struct sock *sk)
253 {
254 struct pppol2tp_tunnel *tunnel;
255
256 if (sk == NULL)
257 return NULL;
258
259 tunnel = (struct pppol2tp_tunnel *)(sk->sk_user_data);
260 if (tunnel == NULL)
261 return NULL;
262
263 BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);
264
265 return tunnel;
266 }
267
268 /* Tunnel reference counts. Incremented per session that is added to
269 * the tunnel.
270 */
271 static inline void pppol2tp_tunnel_inc_refcount(struct pppol2tp_tunnel *tunnel)
272 {
273 atomic_inc(&tunnel->ref_count);
274 }
275
276 static inline void pppol2tp_tunnel_dec_refcount(struct pppol2tp_tunnel *tunnel)
277 {
278 if (atomic_dec_and_test(&tunnel->ref_count))
279 pppol2tp_tunnel_free(tunnel);
280 }
281
282 /* Session hash list.
283 * The session_id SHOULD be random according to RFC2661, but several
284 * L2TP implementations (Cisco and Microsoft) use incrementing
285 * session_ids. So we do a real hash on the session_id, rather than a
286 * simple bitmask.
287 */
288 static inline struct hlist_head *
289 pppol2tp_session_id_hash(struct pppol2tp_tunnel *tunnel, u16 session_id)
290 {
291 unsigned long hash_val = (unsigned long) session_id;
292 return &tunnel->session_hlist[hash_long(hash_val, PPPOL2TP_HASH_BITS)];
293 }
294
295 /* Lookup a session by id
296 */
297 static struct pppol2tp_session *
298 pppol2tp_session_find(struct pppol2tp_tunnel *tunnel, u16 session_id)
299 {
300 struct hlist_head *session_list =
301 pppol2tp_session_id_hash(tunnel, session_id);
302 struct pppol2tp_session *session;
303 struct hlist_node *walk;
304
305 read_lock_bh(&tunnel->hlist_lock);
306 hlist_for_each_entry(session, walk, session_list, hlist) {
307 if (session->tunnel_addr.s_session == session_id) {
308 read_unlock_bh(&tunnel->hlist_lock);
309 return session;
310 }
311 }
312 read_unlock_bh(&tunnel->hlist_lock);
313
314 return NULL;
315 }
316
317 /* Lookup a tunnel by id
318 */
319 static struct pppol2tp_tunnel *pppol2tp_tunnel_find(u16 tunnel_id)
320 {
321 struct pppol2tp_tunnel *tunnel = NULL;
322
323 read_lock_bh(&pppol2tp_tunnel_list_lock);
324 list_for_each_entry(tunnel, &pppol2tp_tunnel_list, list) {
325 if (tunnel->stats.tunnel_id == tunnel_id) {
326 read_unlock_bh(&pppol2tp_tunnel_list_lock);
327 return tunnel;
328 }
329 }
330 read_unlock_bh(&pppol2tp_tunnel_list_lock);
331
332 return NULL;
333 }
334
335 /*****************************************************************************
336 * Receive data handling
337 *****************************************************************************/
338
339 /* Queue a skb in order. We come here only if the skb has an L2TP sequence
340 * number.
341 */
342 static void pppol2tp_recv_queue_skb(struct pppol2tp_session *session, struct sk_buff *skb)
343 {
344 struct sk_buff *skbp;
345 struct sk_buff *tmp;
346 u16 ns = PPPOL2TP_SKB_CB(skb)->ns;
347
348 spin_lock_bh(&session->reorder_q.lock);
349 skb_queue_walk_safe(&session->reorder_q, skbp, tmp) {
350 if (PPPOL2TP_SKB_CB(skbp)->ns > ns) {
351 __skb_insert(skb, skbp->prev, skbp, &session->reorder_q);
352 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
353 "%s: pkt %hu, inserted before %hu, reorder_q len=%d\n",
354 session->name, ns, PPPOL2TP_SKB_CB(skbp)->ns,
355 skb_queue_len(&session->reorder_q));
356 session->stats.rx_oos_packets++;
357 goto out;
358 }
359 }
360
361 __skb_queue_tail(&session->reorder_q, skb);
362
363 out:
364 spin_unlock_bh(&session->reorder_q.lock);
365 }
366
367 /* Dequeue a single skb.
368 */
369 static void pppol2tp_recv_dequeue_skb(struct pppol2tp_session *session, struct sk_buff *skb)
370 {
371 struct pppol2tp_tunnel *tunnel = session->tunnel;
372 int length = PPPOL2TP_SKB_CB(skb)->length;
373 struct sock *session_sock = NULL;
374
375 /* We're about to requeue the skb, so return resources
376 * to its current owner (a socket receive buffer).
377 */
378 skb_orphan(skb);
379
380 tunnel->stats.rx_packets++;
381 tunnel->stats.rx_bytes += length;
382 session->stats.rx_packets++;
383 session->stats.rx_bytes += length;
384
385 if (PPPOL2TP_SKB_CB(skb)->has_seq) {
386 /* Bump our Nr */
387 session->nr++;
388 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
389 "%s: updated nr to %hu\n", session->name, session->nr);
390 }
391
392 /* If the socket is bound, send it in to PPP's input queue. Otherwise
393 * queue it on the session socket.
394 */
395 session_sock = session->sock;
396 if (session_sock->sk_state & PPPOX_BOUND) {
397 struct pppox_sock *po;
398 PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
399 "%s: recv %d byte data frame, passing to ppp\n",
400 session->name, length);
401
402 /* We need to forget all info related to the L2TP packet
403 * gathered in the skb as we are going to reuse the same
404 * skb for the inner packet.
405 * Namely we need to:
406 * - reset xfrm (IPSec) information as it applies to
407 * the outer L2TP packet and not to the inner one
408 * - release the dst to force a route lookup on the inner
409 * IP packet since skb->dst currently points to the dst
410 * of the UDP tunnel
411 * - reset netfilter information as it doesn't apply
412 * to the inner packet either
413 */
414 secpath_reset(skb);
415 dst_release(skb->dst);
416 skb->dst = NULL;
417 nf_reset(skb);
418
419 po = pppox_sk(session_sock);
420 ppp_input(&po->chan, skb);
421 } else {
422 PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_INFO,
423 "%s: socket not bound\n", session->name);
424
425 /* Not bound. Nothing we can do, so discard. */
426 session->stats.rx_errors++;
427 kfree_skb(skb);
428 }
429
430 sock_put(session->sock);
431 }
432
433 /* Dequeue skbs from the session's reorder_q, subject to packet order.
434 * Skbs that have been in the queue for too long are simply discarded.
435 */
436 static void pppol2tp_recv_dequeue(struct pppol2tp_session *session)
437 {
438 struct sk_buff *skb;
439 struct sk_buff *tmp;
440
441 /* If the pkt at the head of the queue has the nr that we
442 * expect to send up next, dequeue it and any other
443 * in-sequence packets behind it.
444 */
445 spin_lock_bh(&session->reorder_q.lock);
446 skb_queue_walk_safe(&session->reorder_q, skb, tmp) {
447 if (time_after(jiffies, PPPOL2TP_SKB_CB(skb)->expires)) {
448 session->stats.rx_seq_discards++;
449 session->stats.rx_errors++;
450 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
451 "%s: oos pkt %hu len %d discarded (too old), "
452 "waiting for %hu, reorder_q_len=%d\n",
453 session->name, PPPOL2TP_SKB_CB(skb)->ns,
454 PPPOL2TP_SKB_CB(skb)->length, session->nr,
455 skb_queue_len(&session->reorder_q));
456 __skb_unlink(skb, &session->reorder_q);
457 kfree_skb(skb);
458 sock_put(session->sock);
459 continue;
460 }
461
462 if (PPPOL2TP_SKB_CB(skb)->has_seq) {
463 if (PPPOL2TP_SKB_CB(skb)->ns != session->nr) {
464 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
465 "%s: holding oos pkt %hu len %d, "
466 "waiting for %hu, reorder_q_len=%d\n",
467 session->name, PPPOL2TP_SKB_CB(skb)->ns,
468 PPPOL2TP_SKB_CB(skb)->length, session->nr,
469 skb_queue_len(&session->reorder_q));
470 goto out;
471 }
472 }
473 __skb_unlink(skb, &session->reorder_q);
474
475 /* Process the skb. We release the queue lock while we
476 * do so to let other contexts process the queue.
477 */
478 spin_unlock_bh(&session->reorder_q.lock);
479 pppol2tp_recv_dequeue_skb(session, skb);
480 spin_lock_bh(&session->reorder_q.lock);
481 }
482
483 out:
484 spin_unlock_bh(&session->reorder_q.lock);
485 }
486
487 /* Internal receive frame. Do the real work of receiving an L2TP data frame
488 * here. The skb is not on a list when we get here.
489 * Returns 0 if the packet was a data packet and was successfully passed on.
490 * Returns 1 if the packet was not a good data packet and could not be
491 * forwarded. All such packets are passed up to userspace to deal with.
492 */
493 static int pppol2tp_recv_core(struct sock *sock, struct sk_buff *skb)
494 {
495 struct pppol2tp_session *session = NULL;
496 struct pppol2tp_tunnel *tunnel;
497 unsigned char *ptr, *optr;
498 u16 hdrflags;
499 u16 tunnel_id, session_id;
500 int length;
501 int offset;
502
503 tunnel = pppol2tp_sock_to_tunnel(sock);
504 if (tunnel == NULL)
505 goto no_tunnel;
506
507 /* UDP always verifies the packet length. */
508 __skb_pull(skb, sizeof(struct udphdr));
509
510 /* Short packet? */
511 if (!pskb_may_pull(skb, 12)) {
512 PRINTK(tunnel->debug, PPPOL2TP_MSG_DATA, KERN_INFO,
513 "%s: recv short packet (len=%d)\n", tunnel->name, skb->len);
514 goto error;
515 }
516
517 /* Point to L2TP header */
518 optr = ptr = skb->data;
519
520 /* Get L2TP header flags */
521 hdrflags = ntohs(*(__be16*)ptr);
522
523 /* Trace packet contents, if enabled */
524 if (tunnel->debug & PPPOL2TP_MSG_DATA) {
525 length = min(16u, skb->len);
526 if (!pskb_may_pull(skb, length))
527 goto error;
528
529 printk(KERN_DEBUG "%s: recv: ", tunnel->name);
530
531 offset = 0;
532 do {
533 printk(" %02X", ptr[offset]);
534 } while (++offset < length);
535
536 printk("\n");
537 }
538
539 /* Get length of L2TP packet */
540 length = skb->len;
541
542 /* If type is control packet, it is handled by userspace. */
543 if (hdrflags & L2TP_HDRFLAG_T) {
544 PRINTK(tunnel->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
545 "%s: recv control packet, len=%d\n", tunnel->name, length);
546 goto error;
547 }
548
549 /* Skip flags */
550 ptr += 2;
551
552 /* If length is present, skip it */
553 if (hdrflags & L2TP_HDRFLAG_L)
554 ptr += 2;
555
556 /* Extract tunnel and session ID */
557 tunnel_id = ntohs(*(__be16 *) ptr);
558 ptr += 2;
559 session_id = ntohs(*(__be16 *) ptr);
560 ptr += 2;
561
562 /* Find the session context */
563 session = pppol2tp_session_find(tunnel, session_id);
564 if (!session) {
565 /* Not found? Pass to userspace to deal with */
566 PRINTK(tunnel->debug, PPPOL2TP_MSG_DATA, KERN_INFO,
567 "%s: no socket found (%hu/%hu). Passing up.\n",
568 tunnel->name, tunnel_id, session_id);
569 goto error;
570 }
571 sock_hold(session->sock);
572
573 /* The ref count on the socket was increased by the above call since
574 * we now hold a pointer to the session. Take care to do sock_put()
575 * when exiting this function from now on...
576 */
577
578 /* Handle the optional sequence numbers. If we are the LAC,
579 * enable/disable sequence numbers under the control of the LNS. If
580 * no sequence numbers present but we were expecting them, discard
581 * frame.
582 */
583 if (hdrflags & L2TP_HDRFLAG_S) {
584 u16 ns, nr;
585 ns = ntohs(*(__be16 *) ptr);
586 ptr += 2;
587 nr = ntohs(*(__be16 *) ptr);
588 ptr += 2;
589
590 /* Received a packet with sequence numbers. If we're the LNS,
591 * check if we sre sending sequence numbers and if not,
592 * configure it so.
593 */
594 if ((!session->lns_mode) && (!session->send_seq)) {
595 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_INFO,
596 "%s: requested to enable seq numbers by LNS\n",
597 session->name);
598 session->send_seq = -1;
599 }
600
601 /* Store L2TP info in the skb */
602 PPPOL2TP_SKB_CB(skb)->ns = ns;
603 PPPOL2TP_SKB_CB(skb)->nr = nr;
604 PPPOL2TP_SKB_CB(skb)->has_seq = 1;
605
606 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
607 "%s: recv data ns=%hu, nr=%hu, session nr=%hu\n",
608 session->name, ns, nr, session->nr);
609 } else {
610 /* No sequence numbers.
611 * If user has configured mandatory sequence numbers, discard.
612 */
613 if (session->recv_seq) {
614 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_WARNING,
615 "%s: recv data has no seq numbers when required. "
616 "Discarding\n", session->name);
617 session->stats.rx_seq_discards++;
618 goto discard;
619 }
620
621 /* If we're the LAC and we're sending sequence numbers, the
622 * LNS has requested that we no longer send sequence numbers.
623 * If we're the LNS and we're sending sequence numbers, the
624 * LAC is broken. Discard the frame.
625 */
626 if ((!session->lns_mode) && (session->send_seq)) {
627 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_INFO,
628 "%s: requested to disable seq numbers by LNS\n",
629 session->name);
630 session->send_seq = 0;
631 } else if (session->send_seq) {
632 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_WARNING,
633 "%s: recv data has no seq numbers when required. "
634 "Discarding\n", session->name);
635 session->stats.rx_seq_discards++;
636 goto discard;
637 }
638
639 /* Store L2TP info in the skb */
640 PPPOL2TP_SKB_CB(skb)->has_seq = 0;
641 }
642
643 /* If offset bit set, skip it. */
644 if (hdrflags & L2TP_HDRFLAG_O) {
645 offset = ntohs(*(__be16 *)ptr);
646 ptr += 2 + offset;
647 }
648
649 offset = ptr - optr;
650 if (!pskb_may_pull(skb, offset))
651 goto discard;
652
653 __skb_pull(skb, offset);
654
655 /* Skip PPP header, if present. In testing, Microsoft L2TP clients
656 * don't send the PPP header (PPP header compression enabled), but
657 * other clients can include the header. So we cope with both cases
658 * here. The PPP header is always FF03 when using L2TP.
659 *
660 * Note that skb->data[] isn't dereferenced from a u16 ptr here since
661 * the field may be unaligned.
662 */
663 if (!pskb_may_pull(skb, 2))
664 goto discard;
665
666 if ((skb->data[0] == 0xff) && (skb->data[1] == 0x03))
667 skb_pull(skb, 2);
668
669 /* Prepare skb for adding to the session's reorder_q. Hold
670 * packets for max reorder_timeout or 1 second if not
671 * reordering.
672 */
673 PPPOL2TP_SKB_CB(skb)->length = length;
674 PPPOL2TP_SKB_CB(skb)->expires = jiffies +
675 (session->reorder_timeout ? session->reorder_timeout : HZ);
676
677 /* Add packet to the session's receive queue. Reordering is done here, if
678 * enabled. Saved L2TP protocol info is stored in skb->sb[].
679 */
680 if (PPPOL2TP_SKB_CB(skb)->has_seq) {
681 if (session->reorder_timeout != 0) {
682 /* Packet reordering enabled. Add skb to session's
683 * reorder queue, in order of ns.
684 */
685 pppol2tp_recv_queue_skb(session, skb);
686 } else {
687 /* Packet reordering disabled. Discard out-of-sequence
688 * packets
689 */
690 if (PPPOL2TP_SKB_CB(skb)->ns != session->nr) {
691 session->stats.rx_seq_discards++;
692 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
693 "%s: oos pkt %hu len %d discarded, "
694 "waiting for %hu, reorder_q_len=%d\n",
695 session->name, PPPOL2TP_SKB_CB(skb)->ns,
696 PPPOL2TP_SKB_CB(skb)->length, session->nr,
697 skb_queue_len(&session->reorder_q));
698 goto discard;
699 }
700 skb_queue_tail(&session->reorder_q, skb);
701 }
702 } else {
703 /* No sequence numbers. Add the skb to the tail of the
704 * reorder queue. This ensures that it will be
705 * delivered after all previous sequenced skbs.
706 */
707 skb_queue_tail(&session->reorder_q, skb);
708 }
709
710 /* Try to dequeue as many skbs from reorder_q as we can. */
711 pppol2tp_recv_dequeue(session);
712
713 return 0;
714
715 discard:
716 session->stats.rx_errors++;
717 kfree_skb(skb);
718 sock_put(session->sock);
719
720 return 0;
721
722 error:
723 /* Put UDP header back */
724 __skb_push(skb, sizeof(struct udphdr));
725
726 no_tunnel:
727 return 1;
728 }
729
730 /* UDP encapsulation receive handler. See net/ipv4/udp.c.
731 * Return codes:
732 * 0 : success.
733 * <0: error
734 * >0: skb should be passed up to userspace as UDP.
735 */
736 static int pppol2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
737 {
738 struct pppol2tp_tunnel *tunnel;
739
740 tunnel = pppol2tp_sock_to_tunnel(sk);
741 if (tunnel == NULL)
742 goto pass_up;
743
744 PRINTK(tunnel->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
745 "%s: received %d bytes\n", tunnel->name, skb->len);
746
747 if (pppol2tp_recv_core(sk, skb))
748 goto pass_up;
749
750 return 0;
751
752 pass_up:
753 return 1;
754 }
755
756 /* Receive message. This is the recvmsg for the PPPoL2TP socket.
757 */
758 static int pppol2tp_recvmsg(struct kiocb *iocb, struct socket *sock,
759 struct msghdr *msg, size_t len,
760 int flags)
761 {
762 int err;
763 struct sk_buff *skb;
764 struct sock *sk = sock->sk;
765
766 err = -EIO;
767 if (sk->sk_state & PPPOX_BOUND)
768 goto end;
769
770 msg->msg_namelen = 0;
771
772 err = 0;
773 skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
774 flags & MSG_DONTWAIT, &err);
775 if (skb) {
776 err = memcpy_toiovec(msg->msg_iov, (unsigned char *) skb->data,
777 skb->len);
778 if (err < 0)
779 goto do_skb_free;
780 err = skb->len;
781 }
782 do_skb_free:
783 kfree_skb(skb);
784 end:
785 return err;
786 }
787
788 /************************************************************************
789 * Transmit handling
790 ***********************************************************************/
791
792 /* Tell how big L2TP headers are for a particular session. This
793 * depends on whether sequence numbers are being used.
794 */
795 static inline int pppol2tp_l2tp_header_len(struct pppol2tp_session *session)
796 {
797 if (session->send_seq)
798 return PPPOL2TP_L2TP_HDR_SIZE_SEQ;
799
800 return PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
801 }
802
803 /* Build an L2TP header for the session into the buffer provided.
804 */
805 static void pppol2tp_build_l2tp_header(struct pppol2tp_session *session,
806 void *buf)
807 {
808 __be16 *bufp = buf;
809 u16 flags = L2TP_HDR_VER;
810
811 if (session->send_seq)
812 flags |= L2TP_HDRFLAG_S;
813
814 /* Setup L2TP header.
815 * FIXME: Can this ever be unaligned? Is direct dereferencing of
816 * 16-bit header fields safe here for all architectures?
817 */
818 *bufp++ = htons(flags);
819 *bufp++ = htons(session->tunnel_addr.d_tunnel);
820 *bufp++ = htons(session->tunnel_addr.d_session);
821 if (session->send_seq) {
822 *bufp++ = htons(session->ns);
823 *bufp++ = 0;
824 session->ns++;
825 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
826 "%s: updated ns to %hu\n", session->name, session->ns);
827 }
828 }
829
830 /* This is the sendmsg for the PPPoL2TP pppol2tp_session socket. We come here
831 * when a user application does a sendmsg() on the session socket. L2TP and
832 * PPP headers must be inserted into the user's data.
833 */
834 static int pppol2tp_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
835 size_t total_len)
836 {
837 static const unsigned char ppph[2] = { 0xff, 0x03 };
838 struct sock *sk = sock->sk;
839 struct inet_sock *inet;
840 __wsum csum = 0;
841 struct sk_buff *skb;
842 int error;
843 int hdr_len;
844 struct pppol2tp_session *session;
845 struct pppol2tp_tunnel *tunnel;
846 struct udphdr *uh;
847 unsigned int len;
848
849 error = -ENOTCONN;
850 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
851 goto error;
852
853 /* Get session and tunnel contexts */
854 error = -EBADF;
855 session = pppol2tp_sock_to_session(sk);
856 if (session == NULL)
857 goto error;
858
859 tunnel = pppol2tp_sock_to_tunnel(session->tunnel_sock);
860 if (tunnel == NULL)
861 goto error;
862
863 /* What header length is configured for this session? */
864 hdr_len = pppol2tp_l2tp_header_len(session);
865
866 /* Allocate a socket buffer */
867 error = -ENOMEM;
868 skb = sock_wmalloc(sk, NET_SKB_PAD + sizeof(struct iphdr) +
869 sizeof(struct udphdr) + hdr_len +
870 sizeof(ppph) + total_len,
871 0, GFP_KERNEL);
872 if (!skb)
873 goto error;
874
875 /* Reserve space for headers. */
876 skb_reserve(skb, NET_SKB_PAD);
877 skb_reset_network_header(skb);
878 skb_reserve(skb, sizeof(struct iphdr));
879 skb_reset_transport_header(skb);
880
881 /* Build UDP header */
882 inet = inet_sk(session->tunnel_sock);
883 uh = (struct udphdr *) skb->data;
884 uh->source = inet->sport;
885 uh->dest = inet->dport;
886 uh->len = htons(hdr_len + sizeof(ppph) + total_len);
887 uh->check = 0;
888 skb_put(skb, sizeof(struct udphdr));
889
890 /* Build L2TP header */
891 pppol2tp_build_l2tp_header(session, skb->data);
892 skb_put(skb, hdr_len);
893
894 /* Add PPP header */
895 skb->data[0] = ppph[0];
896 skb->data[1] = ppph[1];
897 skb_put(skb, 2);
898
899 /* Copy user data into skb */
900 error = memcpy_fromiovec(skb->data, m->msg_iov, total_len);
901 if (error < 0) {
902 kfree_skb(skb);
903 goto error;
904 }
905 skb_put(skb, total_len);
906
907 /* Calculate UDP checksum if configured to do so */
908 if (session->tunnel_sock->sk_no_check != UDP_CSUM_NOXMIT)
909 csum = udp_csum_outgoing(sk, skb);
910
911 /* Debug */
912 if (session->send_seq)
913 PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
914 "%s: send %Zd bytes, ns=%hu\n", session->name,
915 total_len, session->ns - 1);
916 else
917 PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
918 "%s: send %Zd bytes\n", session->name, total_len);
919
920 if (session->debug & PPPOL2TP_MSG_DATA) {
921 int i;
922 unsigned char *datap = skb->data;
923
924 printk(KERN_DEBUG "%s: xmit:", session->name);
925 for (i = 0; i < total_len; i++) {
926 printk(" %02X", *datap++);
927 if (i == 15) {
928 printk(" ...");
929 break;
930 }
931 }
932 printk("\n");
933 }
934
935 /* Queue the packet to IP for output */
936 len = skb->len;
937 error = ip_queue_xmit(skb, 1);
938
939 /* Update stats */
940 if (error >= 0) {
941 tunnel->stats.tx_packets++;
942 tunnel->stats.tx_bytes += len;
943 session->stats.tx_packets++;
944 session->stats.tx_bytes += len;
945 } else {
946 tunnel->stats.tx_errors++;
947 session->stats.tx_errors++;
948 }
949
950 error:
951 return error;
952 }
953
954 /* Transmit function called by generic PPP driver. Sends PPP frame
955 * over PPPoL2TP socket.
956 *
957 * This is almost the same as pppol2tp_sendmsg(), but rather than
958 * being called with a msghdr from userspace, it is called with a skb
959 * from the kernel.
960 *
961 * The supplied skb from ppp doesn't have enough headroom for the
962 * insertion of L2TP, UDP and IP headers so we need to allocate more
963 * headroom in the skb. This will create a cloned skb. But we must be
964 * careful in the error case because the caller will expect to free
965 * the skb it supplied, not our cloned skb. So we take care to always
966 * leave the original skb unfreed if we return an error.
967 */
968 static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
969 {
970 static const u8 ppph[2] = { 0xff, 0x03 };
971 struct sock *sk = (struct sock *) chan->private;
972 struct sock *sk_tun;
973 int hdr_len;
974 struct pppol2tp_session *session;
975 struct pppol2tp_tunnel *tunnel;
976 int rc;
977 int headroom;
978 int data_len = skb->len;
979 struct inet_sock *inet;
980 __wsum csum = 0;
981 struct udphdr *uh;
982 unsigned int len;
983
984 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
985 goto abort;
986
987 /* Get session and tunnel contexts from the socket */
988 session = pppol2tp_sock_to_session(sk);
989 if (session == NULL)
990 goto abort;
991
992 sk_tun = session->tunnel_sock;
993 if (sk_tun == NULL)
994 goto abort;
995 tunnel = pppol2tp_sock_to_tunnel(sk_tun);
996 if (tunnel == NULL)
997 goto abort;
998
999 /* What header length is configured for this session? */
1000 hdr_len = pppol2tp_l2tp_header_len(session);
1001
1002 /* Check that there's enough headroom in the skb to insert IP,
1003 * UDP and L2TP and PPP headers. If not enough, expand it to
1004 * make room. Note that a new skb (or a clone) is
1005 * allocated. If we return an error from this point on, make
1006 * sure we free the new skb but do not free the original skb
1007 * since that is done by the caller for the error case.
1008 */
1009 headroom = NET_SKB_PAD + sizeof(struct iphdr) +
1010 sizeof(struct udphdr) + hdr_len + sizeof(ppph);
1011 if (skb_cow_head(skb, headroom))
1012 goto abort;
1013
1014 /* Setup PPP header */
1015 __skb_push(skb, sizeof(ppph));
1016 skb->data[0] = ppph[0];
1017 skb->data[1] = ppph[1];
1018
1019 /* Setup L2TP header */
1020 pppol2tp_build_l2tp_header(session, __skb_push(skb, hdr_len));
1021
1022 /* Setup UDP header */
1023 inet = inet_sk(sk_tun);
1024 __skb_push(skb, sizeof(*uh));
1025 skb_reset_transport_header(skb);
1026 uh = udp_hdr(skb);
1027 uh->source = inet->sport;
1028 uh->dest = inet->dport;
1029 uh->len = htons(sizeof(struct udphdr) + hdr_len + sizeof(ppph) + data_len);
1030 uh->check = 0;
1031
1032 /* *BROKEN* Calculate UDP checksum if configured to do so */
1033 if (sk_tun->sk_no_check != UDP_CSUM_NOXMIT)
1034 csum = udp_csum_outgoing(sk_tun, skb);
1035
1036 /* Debug */
1037 if (session->send_seq)
1038 PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
1039 "%s: send %d bytes, ns=%hu\n", session->name,
1040 data_len, session->ns - 1);
1041 else
1042 PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
1043 "%s: send %d bytes\n", session->name, data_len);
1044
1045 if (session->debug & PPPOL2TP_MSG_DATA) {
1046 int i;
1047 unsigned char *datap = skb->data;
1048
1049 printk(KERN_DEBUG "%s: xmit:", session->name);
1050 for (i = 0; i < data_len; i++) {
1051 printk(" %02X", *datap++);
1052 if (i == 31) {
1053 printk(" ...");
1054 break;
1055 }
1056 }
1057 printk("\n");
1058 }
1059
1060 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1061 IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED |
1062 IPSKB_REROUTED);
1063 nf_reset(skb);
1064
1065 /* Get routing info from the tunnel socket */
1066 dst_release(skb->dst);
1067 skb->dst = dst_clone(__sk_dst_get(sk_tun));
1068 skb_orphan(skb);
1069 skb->sk = sk_tun;
1070
1071 /* Queue the packet to IP for output */
1072 len = skb->len;
1073 rc = ip_queue_xmit(skb, 1);
1074
1075 /* Update stats */
1076 if (rc >= 0) {
1077 tunnel->stats.tx_packets++;
1078 tunnel->stats.tx_bytes += len;
1079 session->stats.tx_packets++;
1080 session->stats.tx_bytes += len;
1081 } else {
1082 tunnel->stats.tx_errors++;
1083 session->stats.tx_errors++;
1084 }
1085
1086 return 1;
1087
1088 abort:
1089 /* Free the original skb */
1090 kfree_skb(skb);
1091 return 1;
1092 }
1093
1094 /*****************************************************************************
1095 * Session (and tunnel control) socket create/destroy.
1096 *****************************************************************************/
1097
1098 /* When the tunnel UDP socket is closed, all the attached sockets need to go
1099 * too.
1100 */
1101 static void pppol2tp_tunnel_closeall(struct pppol2tp_tunnel *tunnel)
1102 {
1103 int hash;
1104 struct hlist_node *walk;
1105 struct hlist_node *tmp;
1106 struct pppol2tp_session *session;
1107 struct sock *sk;
1108
1109 if (tunnel == NULL)
1110 BUG();
1111
1112 PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1113 "%s: closing all sessions...\n", tunnel->name);
1114
1115 write_lock_bh(&tunnel->hlist_lock);
1116 for (hash = 0; hash < PPPOL2TP_HASH_SIZE; hash++) {
1117 again:
1118 hlist_for_each_safe(walk, tmp, &tunnel->session_hlist[hash]) {
1119 struct sk_buff *skb;
1120
1121 session = hlist_entry(walk, struct pppol2tp_session, hlist);
1122
1123 sk = session->sock;
1124
1125 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1126 "%s: closing session\n", session->name);
1127
1128 hlist_del_init(&session->hlist);
1129
1130 /* Since we should hold the sock lock while
1131 * doing any unbinding, we need to release the
1132 * lock we're holding before taking that lock.
1133 * Hold a reference to the sock so it doesn't
1134 * disappear as we're jumping between locks.
1135 */
1136 sock_hold(sk);
1137 write_unlock_bh(&tunnel->hlist_lock);
1138 lock_sock(sk);
1139
1140 if (sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND)) {
1141 pppox_unbind_sock(sk);
1142 sk->sk_state = PPPOX_DEAD;
1143 sk->sk_state_change(sk);
1144 }
1145
1146 /* Purge any queued data */
1147 skb_queue_purge(&sk->sk_receive_queue);
1148 skb_queue_purge(&sk->sk_write_queue);
1149 while ((skb = skb_dequeue(&session->reorder_q))) {
1150 kfree_skb(skb);
1151 sock_put(sk);
1152 }
1153
1154 release_sock(sk);
1155 sock_put(sk);
1156
1157 /* Now restart from the beginning of this hash
1158 * chain. We always remove a session from the
1159 * list so we are guaranteed to make forward
1160 * progress.
1161 */
1162 write_lock_bh(&tunnel->hlist_lock);
1163 goto again;
1164 }
1165 }
1166 write_unlock_bh(&tunnel->hlist_lock);
1167 }
1168
1169 /* Really kill the tunnel.
1170 * Come here only when all sessions have been cleared from the tunnel.
1171 */
1172 static void pppol2tp_tunnel_free(struct pppol2tp_tunnel *tunnel)
1173 {
1174 /* Remove from socket list */
1175 write_lock_bh(&pppol2tp_tunnel_list_lock);
1176 list_del_init(&tunnel->list);
1177 write_unlock_bh(&pppol2tp_tunnel_list_lock);
1178
1179 atomic_dec(&pppol2tp_tunnel_count);
1180 kfree(tunnel);
1181 }
1182
1183 /* Tunnel UDP socket destruct hook.
1184 * The tunnel context is deleted only when all session sockets have been
1185 * closed.
1186 */
1187 static void pppol2tp_tunnel_destruct(struct sock *sk)
1188 {
1189 struct pppol2tp_tunnel *tunnel;
1190
1191 tunnel = pppol2tp_sock_to_tunnel(sk);
1192 if (tunnel == NULL)
1193 goto end;
1194
1195 PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1196 "%s: closing...\n", tunnel->name);
1197
1198 /* Close all sessions */
1199 pppol2tp_tunnel_closeall(tunnel);
1200
1201 /* No longer an encapsulation socket. See net/ipv4/udp.c */
1202 (udp_sk(sk))->encap_type = 0;
1203 (udp_sk(sk))->encap_rcv = NULL;
1204
1205 /* Remove hooks into tunnel socket */
1206 tunnel->sock = NULL;
1207 sk->sk_destruct = tunnel->old_sk_destruct;
1208 sk->sk_user_data = NULL;
1209
1210 /* Call original (UDP) socket descructor */
1211 if (sk->sk_destruct != NULL)
1212 (*sk->sk_destruct)(sk);
1213
1214 pppol2tp_tunnel_dec_refcount(tunnel);
1215
1216 end:
1217 return;
1218 }
1219
1220 /* Really kill the session socket. (Called from sock_put() if
1221 * refcnt == 0.)
1222 */
1223 static void pppol2tp_session_destruct(struct sock *sk)
1224 {
1225 struct pppol2tp_session *session = NULL;
1226
1227 if (sk->sk_user_data != NULL) {
1228 struct pppol2tp_tunnel *tunnel;
1229
1230 session = pppol2tp_sock_to_session(sk);
1231 if (session == NULL)
1232 goto out;
1233
1234 /* Don't use pppol2tp_sock_to_tunnel() here to
1235 * get the tunnel context because the tunnel
1236 * socket might have already been closed (its
1237 * sk->sk_user_data will be NULL) so use the
1238 * session's private tunnel ptr instead.
1239 */
1240 tunnel = session->tunnel;
1241 if (tunnel != NULL) {
1242 BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);
1243
1244 /* If session_id is zero, this is a null
1245 * session context, which was created for a
1246 * socket that is being used only to manage
1247 * tunnels.
1248 */
1249 if (session->tunnel_addr.s_session != 0) {
1250 /* Delete the session socket from the
1251 * hash
1252 */
1253 write_lock_bh(&tunnel->hlist_lock);
1254 hlist_del_init(&session->hlist);
1255 write_unlock_bh(&tunnel->hlist_lock);
1256
1257 atomic_dec(&pppol2tp_session_count);
1258 }
1259
1260 /* This will delete the tunnel context if this
1261 * is the last session on the tunnel.
1262 */
1263 session->tunnel = NULL;
1264 session->tunnel_sock = NULL;
1265 pppol2tp_tunnel_dec_refcount(tunnel);
1266 }
1267 }
1268
1269 kfree(session);
1270 out:
1271 return;
1272 }
1273
1274 /* Called when the PPPoX socket (session) is closed.
1275 */
1276 static int pppol2tp_release(struct socket *sock)
1277 {
1278 struct sock *sk = sock->sk;
1279 int error;
1280
1281 if (!sk)
1282 return 0;
1283
1284 error = -EBADF;
1285 lock_sock(sk);
1286 if (sock_flag(sk, SOCK_DEAD) != 0)
1287 goto error;
1288
1289 pppox_unbind_sock(sk);
1290
1291 /* Signal the death of the socket. */
1292 sk->sk_state = PPPOX_DEAD;
1293 sock_orphan(sk);
1294 sock->sk = NULL;
1295
1296 /* Purge any queued data */
1297 skb_queue_purge(&sk->sk_receive_queue);
1298 skb_queue_purge(&sk->sk_write_queue);
1299
1300 release_sock(sk);
1301
1302 /* This will delete the session context via
1303 * pppol2tp_session_destruct() if the socket's refcnt drops to
1304 * zero.
1305 */
1306 sock_put(sk);
1307
1308 return 0;
1309
1310 error:
1311 release_sock(sk);
1312 return error;
1313 }
1314
1315 /* Internal function to prepare a tunnel (UDP) socket to have PPPoX
1316 * sockets attached to it.
1317 */
1318 static struct sock *pppol2tp_prepare_tunnel_socket(int fd, u16 tunnel_id,
1319 int *error)
1320 {
1321 int err;
1322 struct socket *sock = NULL;
1323 struct sock *sk;
1324 struct pppol2tp_tunnel *tunnel;
1325 struct sock *ret = NULL;
1326
1327 /* Get the tunnel UDP socket from the fd, which was opened by
1328 * the userspace L2TP daemon.
1329 */
1330 err = -EBADF;
1331 sock = sockfd_lookup(fd, &err);
1332 if (!sock) {
1333 PRINTK(-1, PPPOL2TP_MSG_CONTROL, KERN_ERR,
1334 "tunl %hu: sockfd_lookup(fd=%d) returned %d\n",
1335 tunnel_id, fd, err);
1336 goto err;
1337 }
1338
1339 sk = sock->sk;
1340
1341 /* Quick sanity checks */
1342 err = -EPROTONOSUPPORT;
1343 if (sk->sk_protocol != IPPROTO_UDP) {
1344 PRINTK(-1, PPPOL2TP_MSG_CONTROL, KERN_ERR,
1345 "tunl %hu: fd %d wrong protocol, got %d, expected %d\n",
1346 tunnel_id, fd, sk->sk_protocol, IPPROTO_UDP);
1347 goto err;
1348 }
1349 err = -EAFNOSUPPORT;
1350 if (sock->ops->family != AF_INET) {
1351 PRINTK(-1, PPPOL2TP_MSG_CONTROL, KERN_ERR,
1352 "tunl %hu: fd %d wrong family, got %d, expected %d\n",
1353 tunnel_id, fd, sock->ops->family, AF_INET);
1354 goto err;
1355 }
1356
1357 err = -ENOTCONN;
1358
1359 /* Check if this socket has already been prepped */
1360 tunnel = (struct pppol2tp_tunnel *)sk->sk_user_data;
1361 if (tunnel != NULL) {
1362 /* User-data field already set */
1363 err = -EBUSY;
1364 BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);
1365
1366 /* This socket has already been prepped */
1367 ret = tunnel->sock;
1368 goto out;
1369 }
1370
1371 /* This socket is available and needs prepping. Create a new tunnel
1372 * context and init it.
1373 */
1374 sk->sk_user_data = tunnel = kzalloc(sizeof(struct pppol2tp_tunnel), GFP_KERNEL);
1375 if (sk->sk_user_data == NULL) {
1376 err = -ENOMEM;
1377 goto err;
1378 }
1379
1380 tunnel->magic = L2TP_TUNNEL_MAGIC;
1381 sprintf(&tunnel->name[0], "tunl %hu", tunnel_id);
1382
1383 tunnel->stats.tunnel_id = tunnel_id;
1384 tunnel->debug = PPPOL2TP_DEFAULT_DEBUG_FLAGS;
1385
1386 /* Hook on the tunnel socket destructor so that we can cleanup
1387 * if the tunnel socket goes away.
1388 */
1389 tunnel->old_sk_destruct = sk->sk_destruct;
1390 sk->sk_destruct = &pppol2tp_tunnel_destruct;
1391
1392 tunnel->sock = sk;
1393 sk->sk_allocation = GFP_ATOMIC;
1394
1395 /* Misc init */
1396 rwlock_init(&tunnel->hlist_lock);
1397
1398 /* Add tunnel to our list */
1399 INIT_LIST_HEAD(&tunnel->list);
1400 write_lock_bh(&pppol2tp_tunnel_list_lock);
1401 list_add(&tunnel->list, &pppol2tp_tunnel_list);
1402 write_unlock_bh(&pppol2tp_tunnel_list_lock);
1403 atomic_inc(&pppol2tp_tunnel_count);
1404
1405 /* Bump the reference count. The tunnel context is deleted
1406 * only when this drops to zero.
1407 */
1408 pppol2tp_tunnel_inc_refcount(tunnel);
1409
1410 /* Mark socket as an encapsulation socket. See net/ipv4/udp.c */
1411 (udp_sk(sk))->encap_type = UDP_ENCAP_L2TPINUDP;
1412 (udp_sk(sk))->encap_rcv = pppol2tp_udp_encap_recv;
1413
1414 ret = tunnel->sock;
1415
1416 *error = 0;
1417 out:
1418 if (sock)
1419 sockfd_put(sock);
1420
1421 return ret;
1422
1423 err:
1424 *error = err;
1425 goto out;
1426 }
1427
1428 static struct proto pppol2tp_sk_proto = {
1429 .name = "PPPOL2TP",
1430 .owner = THIS_MODULE,
1431 .obj_size = sizeof(struct pppox_sock),
1432 };
1433
1434 /* socket() handler. Initialize a new struct sock.
1435 */
1436 static int pppol2tp_create(struct net *net, struct socket *sock)
1437 {
1438 int error = -ENOMEM;
1439 struct sock *sk;
1440
1441 sk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, &pppol2tp_sk_proto);
1442 if (!sk)
1443 goto out;
1444
1445 sock_init_data(sock, sk);
1446
1447 sock->state = SS_UNCONNECTED;
1448 sock->ops = &pppol2tp_ops;
1449
1450 sk->sk_backlog_rcv = pppol2tp_recv_core;
1451 sk->sk_protocol = PX_PROTO_OL2TP;
1452 sk->sk_family = PF_PPPOX;
1453 sk->sk_state = PPPOX_NONE;
1454 sk->sk_type = SOCK_STREAM;
1455 sk->sk_destruct = pppol2tp_session_destruct;
1456
1457 error = 0;
1458
1459 out:
1460 return error;
1461 }
1462
1463 /* connect() handler. Attach a PPPoX socket to a tunnel UDP socket
1464 */
1465 static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr,
1466 int sockaddr_len, int flags)
1467 {
1468 struct sock *sk = sock->sk;
1469 struct sockaddr_pppol2tp *sp = (struct sockaddr_pppol2tp *) uservaddr;
1470 struct pppox_sock *po = pppox_sk(sk);
1471 struct sock *tunnel_sock = NULL;
1472 struct pppol2tp_session *session = NULL;
1473 struct pppol2tp_tunnel *tunnel;
1474 struct dst_entry *dst;
1475 int error = 0;
1476
1477 lock_sock(sk);
1478
1479 error = -EINVAL;
1480 if (sp->sa_protocol != PX_PROTO_OL2TP)
1481 goto end;
1482
1483 /* Check for already bound sockets */
1484 error = -EBUSY;
1485 if (sk->sk_state & PPPOX_CONNECTED)
1486 goto end;
1487
1488 /* We don't supporting rebinding anyway */
1489 error = -EALREADY;
1490 if (sk->sk_user_data)
1491 goto end; /* socket is already attached */
1492
1493 /* Don't bind if s_tunnel is 0 */
1494 error = -EINVAL;
1495 if (sp->pppol2tp.s_tunnel == 0)
1496 goto end;
1497
1498 /* Special case: prepare tunnel socket if s_session and
1499 * d_session is 0. Otherwise look up tunnel using supplied
1500 * tunnel id.
1501 */
1502 if ((sp->pppol2tp.s_session == 0) && (sp->pppol2tp.d_session == 0)) {
1503 tunnel_sock = pppol2tp_prepare_tunnel_socket(sp->pppol2tp.fd,
1504 sp->pppol2tp.s_tunnel,
1505 &error);
1506 if (tunnel_sock == NULL)
1507 goto end;
1508
1509 tunnel = tunnel_sock->sk_user_data;
1510 } else {
1511 tunnel = pppol2tp_tunnel_find(sp->pppol2tp.s_tunnel);
1512
1513 /* Error if we can't find the tunnel */
1514 error = -ENOENT;
1515 if (tunnel == NULL)
1516 goto end;
1517
1518 tunnel_sock = tunnel->sock;
1519 }
1520
1521 /* Check that this session doesn't already exist */
1522 error = -EEXIST;
1523 session = pppol2tp_session_find(tunnel, sp->pppol2tp.s_session);
1524 if (session != NULL)
1525 goto end;
1526
1527 /* Allocate and initialize a new session context. */
1528 session = kzalloc(sizeof(struct pppol2tp_session), GFP_KERNEL);
1529 if (session == NULL) {
1530 error = -ENOMEM;
1531 goto end;
1532 }
1533
1534 skb_queue_head_init(&session->reorder_q);
1535
1536 session->magic = L2TP_SESSION_MAGIC;
1537 session->owner = current->pid;
1538 session->sock = sk;
1539 session->tunnel = tunnel;
1540 session->tunnel_sock = tunnel_sock;
1541 session->tunnel_addr = sp->pppol2tp;
1542 sprintf(&session->name[0], "sess %hu/%hu",
1543 session->tunnel_addr.s_tunnel,
1544 session->tunnel_addr.s_session);
1545
1546 session->stats.tunnel_id = session->tunnel_addr.s_tunnel;
1547 session->stats.session_id = session->tunnel_addr.s_session;
1548
1549 INIT_HLIST_NODE(&session->hlist);
1550
1551 /* Inherit debug options from tunnel */
1552 session->debug = tunnel->debug;
1553
1554 /* Default MTU must allow space for UDP/L2TP/PPP
1555 * headers.
1556 */
1557 session->mtu = session->mru = 1500 - PPPOL2TP_HEADER_OVERHEAD;
1558
1559 /* If PMTU discovery was enabled, use the MTU that was discovered */
1560 dst = sk_dst_get(sk);
1561 if (dst != NULL) {
1562 u32 pmtu = dst_mtu(__sk_dst_get(sk));
1563 if (pmtu != 0)
1564 session->mtu = session->mru = pmtu -
1565 PPPOL2TP_HEADER_OVERHEAD;
1566 dst_release(dst);
1567 }
1568
1569 /* Special case: if source & dest session_id == 0x0000, this socket is
1570 * being created to manage the tunnel. Don't add the session to the
1571 * session hash list, just set up the internal context for use by
1572 * ioctl() and sockopt() handlers.
1573 */
1574 if ((session->tunnel_addr.s_session == 0) &&
1575 (session->tunnel_addr.d_session == 0)) {
1576 error = 0;
1577 sk->sk_user_data = session;
1578 goto out_no_ppp;
1579 }
1580
1581 /* Get tunnel context from the tunnel socket */
1582 tunnel = pppol2tp_sock_to_tunnel(tunnel_sock);
1583 if (tunnel == NULL) {
1584 error = -EBADF;
1585 goto end;
1586 }
1587
1588 /* Right now, because we don't have a way to push the incoming skb's
1589 * straight through the UDP layer, the only header we need to worry
1590 * about is the L2TP header. This size is different depending on
1591 * whether sequence numbers are enabled for the data channel.
1592 */
1593 po->chan.hdrlen = PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
1594
1595 po->chan.private = sk;
1596 po->chan.ops = &pppol2tp_chan_ops;
1597 po->chan.mtu = session->mtu;
1598
1599 error = ppp_register_channel(&po->chan);
1600 if (error)
1601 goto end;
1602
1603 /* This is how we get the session context from the socket. */
1604 sk->sk_user_data = session;
1605
1606 /* Add session to the tunnel's hash list */
1607 write_lock_bh(&tunnel->hlist_lock);
1608 hlist_add_head(&session->hlist,
1609 pppol2tp_session_id_hash(tunnel,
1610 session->tunnel_addr.s_session));
1611 write_unlock_bh(&tunnel->hlist_lock);
1612
1613 atomic_inc(&pppol2tp_session_count);
1614
1615 out_no_ppp:
1616 pppol2tp_tunnel_inc_refcount(tunnel);
1617 sk->sk_state = PPPOX_CONNECTED;
1618 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1619 "%s: created\n", session->name);
1620
1621 end:
1622 release_sock(sk);
1623
1624 if (error != 0) {
1625 if (session)
1626 PRINTK(session->debug,
1627 PPPOL2TP_MSG_CONTROL, KERN_WARNING,
1628 "%s: connect failed: %d\n",
1629 session->name, error);
1630 else
1631 PRINTK(-1, PPPOL2TP_MSG_CONTROL, KERN_WARNING,
1632 "connect failed: %d\n", error);
1633 }
1634
1635 return error;
1636 }
1637
1638 /* getname() support.
1639 */
1640 static int pppol2tp_getname(struct socket *sock, struct sockaddr *uaddr,
1641 int *usockaddr_len, int peer)
1642 {
1643 int len = sizeof(struct sockaddr_pppol2tp);
1644 struct sockaddr_pppol2tp sp;
1645 int error = 0;
1646 struct pppol2tp_session *session;
1647
1648 error = -ENOTCONN;
1649 if (sock->sk->sk_state != PPPOX_CONNECTED)
1650 goto end;
1651
1652 session = pppol2tp_sock_to_session(sock->sk);
1653 if (session == NULL) {
1654 error = -EBADF;
1655 goto end;
1656 }
1657
1658 sp.sa_family = AF_PPPOX;
1659 sp.sa_protocol = PX_PROTO_OL2TP;
1660 memcpy(&sp.pppol2tp, &session->tunnel_addr,
1661 sizeof(struct pppol2tp_addr));
1662
1663 memcpy(uaddr, &sp, len);
1664
1665 *usockaddr_len = len;
1666
1667 error = 0;
1668
1669 end:
1670 return error;
1671 }
1672
1673 /****************************************************************************
1674 * ioctl() handlers.
1675 *
1676 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
1677 * sockets. However, in order to control kernel tunnel features, we allow
1678 * userspace to create a special "tunnel" PPPoX socket which is used for
1679 * control only. Tunnel PPPoX sockets have session_id == 0 and simply allow
1680 * the user application to issue L2TP setsockopt(), getsockopt() and ioctl()
1681 * calls.
1682 ****************************************************************************/
1683
1684 /* Session ioctl helper.
1685 */
1686 static int pppol2tp_session_ioctl(struct pppol2tp_session *session,
1687 unsigned int cmd, unsigned long arg)
1688 {
1689 struct ifreq ifr;
1690 int err = 0;
1691 struct sock *sk = session->sock;
1692 int val = (int) arg;
1693
1694 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_DEBUG,
1695 "%s: pppol2tp_session_ioctl(cmd=%#x, arg=%#lx)\n",
1696 session->name, cmd, arg);
1697
1698 sock_hold(sk);
1699
1700 switch (cmd) {
1701 case SIOCGIFMTU:
1702 err = -ENXIO;
1703 if (!(sk->sk_state & PPPOX_CONNECTED))
1704 break;
1705
1706 err = -EFAULT;
1707 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq)))
1708 break;
1709 ifr.ifr_mtu = session->mtu;
1710 if (copy_to_user((void __user *) arg, &ifr, sizeof(struct ifreq)))
1711 break;
1712
1713 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1714 "%s: get mtu=%d\n", session->name, session->mtu);
1715 err = 0;
1716 break;
1717
1718 case SIOCSIFMTU:
1719 err = -ENXIO;
1720 if (!(sk->sk_state & PPPOX_CONNECTED))
1721 break;
1722
1723 err = -EFAULT;
1724 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq)))
1725 break;
1726
1727 session->mtu = ifr.ifr_mtu;
1728
1729 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1730 "%s: set mtu=%d\n", session->name, session->mtu);
1731 err = 0;
1732 break;
1733
1734 case PPPIOCGMRU:
1735 err = -ENXIO;
1736 if (!(sk->sk_state & PPPOX_CONNECTED))
1737 break;
1738
1739 err = -EFAULT;
1740 if (put_user(session->mru, (int __user *) arg))
1741 break;
1742
1743 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1744 "%s: get mru=%d\n", session->name, session->mru);
1745 err = 0;
1746 break;
1747
1748 case PPPIOCSMRU:
1749 err = -ENXIO;
1750 if (!(sk->sk_state & PPPOX_CONNECTED))
1751 break;
1752
1753 err = -EFAULT;
1754 if (get_user(val,(int __user *) arg))
1755 break;
1756
1757 session->mru = val;
1758 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1759 "%s: set mru=%d\n", session->name, session->mru);
1760 err = 0;
1761 break;
1762
1763 case PPPIOCGFLAGS:
1764 err = -EFAULT;
1765 if (put_user(session->flags, (int __user *) arg))
1766 break;
1767
1768 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1769 "%s: get flags=%d\n", session->name, session->flags);
1770 err = 0;
1771 break;
1772
1773 case PPPIOCSFLAGS:
1774 err = -EFAULT;
1775 if (get_user(val, (int __user *) arg))
1776 break;
1777 session->flags = val;
1778 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1779 "%s: set flags=%d\n", session->name, session->flags);
1780 err = 0;
1781 break;
1782
1783 case PPPIOCGL2TPSTATS:
1784 err = -ENXIO;
1785 if (!(sk->sk_state & PPPOX_CONNECTED))
1786 break;
1787
1788 if (copy_to_user((void __user *) arg, &session->stats,
1789 sizeof(session->stats)))
1790 break;
1791 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1792 "%s: get L2TP stats\n", session->name);
1793 err = 0;
1794 break;
1795
1796 default:
1797 err = -ENOSYS;
1798 break;
1799 }
1800
1801 sock_put(sk);
1802
1803 return err;
1804 }
1805
1806 /* Tunnel ioctl helper.
1807 *
1808 * Note the special handling for PPPIOCGL2TPSTATS below. If the ioctl data
1809 * specifies a session_id, the session ioctl handler is called. This allows an
1810 * application to retrieve session stats via a tunnel socket.
1811 */
1812 static int pppol2tp_tunnel_ioctl(struct pppol2tp_tunnel *tunnel,
1813 unsigned int cmd, unsigned long arg)
1814 {
1815 int err = 0;
1816 struct sock *sk = tunnel->sock;
1817 struct pppol2tp_ioc_stats stats_req;
1818
1819 PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_DEBUG,
1820 "%s: pppol2tp_tunnel_ioctl(cmd=%#x, arg=%#lx)\n", tunnel->name,
1821 cmd, arg);
1822
1823 sock_hold(sk);
1824
1825 switch (cmd) {
1826 case PPPIOCGL2TPSTATS:
1827 err = -ENXIO;
1828 if (!(sk->sk_state & PPPOX_CONNECTED))
1829 break;
1830
1831 if (copy_from_user(&stats_req, (void __user *) arg,
1832 sizeof(stats_req))) {
1833 err = -EFAULT;
1834 break;
1835 }
1836 if (stats_req.session_id != 0) {
1837 /* resend to session ioctl handler */
1838 struct pppol2tp_session *session =
1839 pppol2tp_session_find(tunnel, stats_req.session_id);
1840 if (session != NULL)
1841 err = pppol2tp_session_ioctl(session, cmd, arg);
1842 else
1843 err = -EBADR;
1844 break;
1845 }
1846 #ifdef CONFIG_XFRM
1847 tunnel->stats.using_ipsec = (sk->sk_policy[0] || sk->sk_policy[1]) ? 1 : 0;
1848 #endif
1849 if (copy_to_user((void __user *) arg, &tunnel->stats,
1850 sizeof(tunnel->stats))) {
1851 err = -EFAULT;
1852 break;
1853 }
1854 PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1855 "%s: get L2TP stats\n", tunnel->name);
1856 err = 0;
1857 break;
1858
1859 default:
1860 err = -ENOSYS;
1861 break;
1862 }
1863
1864 sock_put(sk);
1865
1866 return err;
1867 }
1868
1869 /* Main ioctl() handler.
1870 * Dispatch to tunnel or session helpers depending on the socket.
1871 */
1872 static int pppol2tp_ioctl(struct socket *sock, unsigned int cmd,
1873 unsigned long arg)
1874 {
1875 struct sock *sk = sock->sk;
1876 struct pppol2tp_session *session;
1877 struct pppol2tp_tunnel *tunnel;
1878 int err;
1879
1880 if (!sk)
1881 return 0;
1882
1883 err = -EBADF;
1884 if (sock_flag(sk, SOCK_DEAD) != 0)
1885 goto end;
1886
1887 err = -ENOTCONN;
1888 if ((sk->sk_user_data == NULL) ||
1889 (!(sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND))))
1890 goto end;
1891
1892 /* Get session context from the socket */
1893 err = -EBADF;
1894 session = pppol2tp_sock_to_session(sk);
1895 if (session == NULL)
1896 goto end;
1897
1898 /* Special case: if session's session_id is zero, treat ioctl as a
1899 * tunnel ioctl
1900 */
1901 if ((session->tunnel_addr.s_session == 0) &&
1902 (session->tunnel_addr.d_session == 0)) {
1903 err = -EBADF;
1904 tunnel = pppol2tp_sock_to_tunnel(session->tunnel_sock);
1905 if (tunnel == NULL)
1906 goto end;
1907
1908 err = pppol2tp_tunnel_ioctl(tunnel, cmd, arg);
1909 goto end;
1910 }
1911
1912 err = pppol2tp_session_ioctl(session, cmd, arg);
1913
1914 end:
1915 return err;
1916 }
1917
1918 /*****************************************************************************
1919 * setsockopt() / getsockopt() support.
1920 *
1921 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
1922 * sockets. In order to control kernel tunnel features, we allow userspace to
1923 * create a special "tunnel" PPPoX socket which is used for control only.
1924 * Tunnel PPPoX sockets have session_id == 0 and simply allow the user
1925 * application to issue L2TP setsockopt(), getsockopt() and ioctl() calls.
1926 *****************************************************************************/
1927
1928 /* Tunnel setsockopt() helper.
1929 */
1930 static int pppol2tp_tunnel_setsockopt(struct sock *sk,
1931 struct pppol2tp_tunnel *tunnel,
1932 int optname, int val)
1933 {
1934 int err = 0;
1935
1936 switch (optname) {
1937 case PPPOL2TP_SO_DEBUG:
1938 tunnel->debug = val;
1939 PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1940 "%s: set debug=%x\n", tunnel->name, tunnel->debug);
1941 break;
1942
1943 default:
1944 err = -ENOPROTOOPT;
1945 break;
1946 }
1947
1948 return err;
1949 }
1950
1951 /* Session setsockopt helper.
1952 */
1953 static int pppol2tp_session_setsockopt(struct sock *sk,
1954 struct pppol2tp_session *session,
1955 int optname, int val)
1956 {
1957 int err = 0;
1958
1959 switch (optname) {
1960 case PPPOL2TP_SO_RECVSEQ:
1961 if ((val != 0) && (val != 1)) {
1962 err = -EINVAL;
1963 break;
1964 }
1965 session->recv_seq = val ? -1 : 0;
1966 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1967 "%s: set recv_seq=%d\n", session->name,
1968 session->recv_seq);
1969 break;
1970
1971 case PPPOL2TP_SO_SENDSEQ:
1972 if ((val != 0) && (val != 1)) {
1973 err = -EINVAL;
1974 break;
1975 }
1976 session->send_seq = val ? -1 : 0;
1977 {
1978 struct sock *ssk = session->sock;
1979 struct pppox_sock *po = pppox_sk(ssk);
1980 po->chan.hdrlen = val ? PPPOL2TP_L2TP_HDR_SIZE_SEQ :
1981 PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
1982 }
1983 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1984 "%s: set send_seq=%d\n", session->name, session->send_seq);
1985 break;
1986
1987 case PPPOL2TP_SO_LNSMODE:
1988 if ((val != 0) && (val != 1)) {
1989 err = -EINVAL;
1990 break;
1991 }
1992 session->lns_mode = val ? -1 : 0;
1993 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1994 "%s: set lns_mode=%d\n", session->name,
1995 session->lns_mode);
1996 break;
1997
1998 case PPPOL2TP_SO_DEBUG:
1999 session->debug = val;
2000 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2001 "%s: set debug=%x\n", session->name, session->debug);
2002 break;
2003
2004 case PPPOL2TP_SO_REORDERTO:
2005 session->reorder_timeout = msecs_to_jiffies(val);
2006 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2007 "%s: set reorder_timeout=%d\n", session->name,
2008 session->reorder_timeout);
2009 break;
2010
2011 default:
2012 err = -ENOPROTOOPT;
2013 break;
2014 }
2015
2016 return err;
2017 }
2018
2019 /* Main setsockopt() entry point.
2020 * Does API checks, then calls either the tunnel or session setsockopt
2021 * handler, according to whether the PPPoL2TP socket is a for a regular
2022 * session or the special tunnel type.
2023 */
2024 static int pppol2tp_setsockopt(struct socket *sock, int level, int optname,
2025 char __user *optval, int optlen)
2026 {
2027 struct sock *sk = sock->sk;
2028 struct pppol2tp_session *session = sk->sk_user_data;
2029 struct pppol2tp_tunnel *tunnel;
2030 int val;
2031 int err;
2032
2033 if (level != SOL_PPPOL2TP)
2034 return udp_prot.setsockopt(sk, level, optname, optval, optlen);
2035
2036 if (optlen < sizeof(int))
2037 return -EINVAL;
2038
2039 if (get_user(val, (int __user *)optval))
2040 return -EFAULT;
2041
2042 err = -ENOTCONN;
2043 if (sk->sk_user_data == NULL)
2044 goto end;
2045
2046 /* Get session context from the socket */
2047 err = -EBADF;
2048 session = pppol2tp_sock_to_session(sk);
2049 if (session == NULL)
2050 goto end;
2051
2052 /* Special case: if session_id == 0x0000, treat as operation on tunnel
2053 */
2054 if ((session->tunnel_addr.s_session == 0) &&
2055 (session->tunnel_addr.d_session == 0)) {
2056 err = -EBADF;
2057 tunnel = pppol2tp_sock_to_tunnel(session->tunnel_sock);
2058 if (tunnel == NULL)
2059 goto end;
2060
2061 err = pppol2tp_tunnel_setsockopt(sk, tunnel, optname, val);
2062 } else
2063 err = pppol2tp_session_setsockopt(sk, session, optname, val);
2064
2065 err = 0;
2066
2067 end:
2068 return err;
2069 }
2070
2071 /* Tunnel getsockopt helper. Called with sock locked.
2072 */
2073 static int pppol2tp_tunnel_getsockopt(struct sock *sk,
2074 struct pppol2tp_tunnel *tunnel,
2075 int optname, int *val)
2076 {
2077 int err = 0;
2078
2079 switch (optname) {
2080 case PPPOL2TP_SO_DEBUG:
2081 *val = tunnel->debug;
2082 PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2083 "%s: get debug=%x\n", tunnel->name, tunnel->debug);
2084 break;
2085
2086 default:
2087 err = -ENOPROTOOPT;
2088 break;
2089 }
2090
2091 return err;
2092 }
2093
2094 /* Session getsockopt helper. Called with sock locked.
2095 */
2096 static int pppol2tp_session_getsockopt(struct sock *sk,
2097 struct pppol2tp_session *session,
2098 int optname, int *val)
2099 {
2100 int err = 0;
2101
2102 switch (optname) {
2103 case PPPOL2TP_SO_RECVSEQ:
2104 *val = session->recv_seq;
2105 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2106 "%s: get recv_seq=%d\n", session->name, *val);
2107 break;
2108
2109 case PPPOL2TP_SO_SENDSEQ:
2110 *val = session->send_seq;
2111 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2112 "%s: get send_seq=%d\n", session->name, *val);
2113 break;
2114
2115 case PPPOL2TP_SO_LNSMODE:
2116 *val = session->lns_mode;
2117 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2118 "%s: get lns_mode=%d\n", session->name, *val);
2119 break;
2120
2121 case PPPOL2TP_SO_DEBUG:
2122 *val = session->debug;
2123 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2124 "%s: get debug=%d\n", session->name, *val);
2125 break;
2126
2127 case PPPOL2TP_SO_REORDERTO:
2128 *val = (int) jiffies_to_msecs(session->reorder_timeout);
2129 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2130 "%s: get reorder_timeout=%d\n", session->name, *val);
2131 break;
2132
2133 default:
2134 err = -ENOPROTOOPT;
2135 }
2136
2137 return err;
2138 }
2139
2140 /* Main getsockopt() entry point.
2141 * Does API checks, then calls either the tunnel or session getsockopt
2142 * handler, according to whether the PPPoX socket is a for a regular session
2143 * or the special tunnel type.
2144 */
2145 static int pppol2tp_getsockopt(struct socket *sock, int level,
2146 int optname, char __user *optval, int __user *optlen)
2147 {
2148 struct sock *sk = sock->sk;
2149 struct pppol2tp_session *session = sk->sk_user_data;
2150 struct pppol2tp_tunnel *tunnel;
2151 int val, len;
2152 int err;
2153
2154 if (level != SOL_PPPOL2TP)
2155 return udp_prot.getsockopt(sk, level, optname, optval, optlen);
2156
2157 if (get_user(len, (int __user *) optlen))
2158 return -EFAULT;
2159
2160 len = min_t(unsigned int, len, sizeof(int));
2161
2162 if (len < 0)
2163 return -EINVAL;
2164
2165 err = -ENOTCONN;
2166 if (sk->sk_user_data == NULL)
2167 goto end;
2168
2169 /* Get the session context */
2170 err = -EBADF;
2171 session = pppol2tp_sock_to_session(sk);
2172 if (session == NULL)
2173 goto end;
2174
2175 /* Special case: if session_id == 0x0000, treat as operation on tunnel */
2176 if ((session->tunnel_addr.s_session == 0) &&
2177 (session->tunnel_addr.d_session == 0)) {
2178 err = -EBADF;
2179 tunnel = pppol2tp_sock_to_tunnel(session->tunnel_sock);
2180 if (tunnel == NULL)
2181 goto end;
2182
2183 err = pppol2tp_tunnel_getsockopt(sk, tunnel, optname, &val);
2184 } else
2185 err = pppol2tp_session_getsockopt(sk, session, optname, &val);
2186
2187 err = -EFAULT;
2188 if (put_user(len, (int __user *) optlen))
2189 goto end;
2190
2191 if (copy_to_user((void __user *) optval, &val, len))
2192 goto end;
2193
2194 err = 0;
2195 end:
2196 return err;
2197 }
2198
2199 /*****************************************************************************
2200 * /proc filesystem for debug
2201 *****************************************************************************/
2202
2203 #ifdef CONFIG_PROC_FS
2204
2205 #include <linux/seq_file.h>
2206
2207 struct pppol2tp_seq_data {
2208 struct pppol2tp_tunnel *tunnel; /* current tunnel */
2209 struct pppol2tp_session *session; /* NULL means get first session in tunnel */
2210 };
2211
2212 static struct pppol2tp_session *next_session(struct pppol2tp_tunnel *tunnel, struct pppol2tp_session *curr)
2213 {
2214 struct pppol2tp_session *session = NULL;
2215 struct hlist_node *walk;
2216 int found = 0;
2217 int next = 0;
2218 int i;
2219
2220 read_lock_bh(&tunnel->hlist_lock);
2221 for (i = 0; i < PPPOL2TP_HASH_SIZE; i++) {
2222 hlist_for_each_entry(session, walk, &tunnel->session_hlist[i], hlist) {
2223 if (curr == NULL) {
2224 found = 1;
2225 goto out;
2226 }
2227 if (session == curr) {
2228 next = 1;
2229 continue;
2230 }
2231 if (next) {
2232 found = 1;
2233 goto out;
2234 }
2235 }
2236 }
2237 out:
2238 read_unlock_bh(&tunnel->hlist_lock);
2239 if (!found)
2240 session = NULL;
2241
2242 return session;
2243 }
2244
2245 static struct pppol2tp_tunnel *next_tunnel(struct pppol2tp_tunnel *curr)
2246 {
2247 struct pppol2tp_tunnel *tunnel = NULL;
2248
2249 read_lock_bh(&pppol2tp_tunnel_list_lock);
2250 if (list_is_last(&curr->list, &pppol2tp_tunnel_list)) {
2251 goto out;
2252 }
2253 tunnel = list_entry(curr->list.next, struct pppol2tp_tunnel, list);
2254 out:
2255 read_unlock_bh(&pppol2tp_tunnel_list_lock);
2256
2257 return tunnel;
2258 }
2259
2260 static void *pppol2tp_seq_start(struct seq_file *m, loff_t *offs)
2261 {
2262 struct pppol2tp_seq_data *pd = SEQ_START_TOKEN;
2263 loff_t pos = *offs;
2264
2265 if (!pos)
2266 goto out;
2267
2268 BUG_ON(m->private == NULL);
2269 pd = m->private;
2270
2271 if (pd->tunnel == NULL) {
2272 if (!list_empty(&pppol2tp_tunnel_list))
2273 pd->tunnel = list_entry(pppol2tp_tunnel_list.next, struct pppol2tp_tunnel, list);
2274 } else {
2275 pd->session = next_session(pd->tunnel, pd->session);
2276 if (pd->session == NULL) {
2277 pd->tunnel = next_tunnel(pd->tunnel);
2278 }
2279 }
2280
2281 /* NULL tunnel and session indicates end of list */
2282 if ((pd->tunnel == NULL) && (pd->session == NULL))
2283 pd = NULL;
2284
2285 out:
2286 return pd;
2287 }
2288
2289 static void *pppol2tp_seq_next(struct seq_file *m, void *v, loff_t *pos)
2290 {
2291 (*pos)++;
2292 return NULL;
2293 }
2294
2295 static void pppol2tp_seq_stop(struct seq_file *p, void *v)
2296 {
2297 /* nothing to do */
2298 }
2299
2300 static void pppol2tp_seq_tunnel_show(struct seq_file *m, void *v)
2301 {
2302 struct pppol2tp_tunnel *tunnel = v;
2303
2304 seq_printf(m, "\nTUNNEL '%s', %c %d\n",
2305 tunnel->name,
2306 (tunnel == tunnel->sock->sk_user_data) ? 'Y':'N',
2307 atomic_read(&tunnel->ref_count) - 1);
2308 seq_printf(m, " %08x %llu/%llu/%llu %llu/%llu/%llu\n",
2309 tunnel->debug,
2310 (unsigned long long)tunnel->stats.tx_packets,
2311 (unsigned long long)tunnel->stats.tx_bytes,
2312 (unsigned long long)tunnel->stats.tx_errors,
2313 (unsigned long long)tunnel->stats.rx_packets,
2314 (unsigned long long)tunnel->stats.rx_bytes,
2315 (unsigned long long)tunnel->stats.rx_errors);
2316 }
2317
2318 static void pppol2tp_seq_session_show(struct seq_file *m, void *v)
2319 {
2320 struct pppol2tp_session *session = v;
2321
2322 seq_printf(m, " SESSION '%s' %08X/%d %04X/%04X -> "
2323 "%04X/%04X %d %c\n",
2324 session->name,
2325 ntohl(session->tunnel_addr.addr.sin_addr.s_addr),
2326 ntohs(session->tunnel_addr.addr.sin_port),
2327 session->tunnel_addr.s_tunnel,
2328 session->tunnel_addr.s_session,
2329 session->tunnel_addr.d_tunnel,
2330 session->tunnel_addr.d_session,
2331 session->sock->sk_state,
2332 (session == session->sock->sk_user_data) ?
2333 'Y' : 'N');
2334 seq_printf(m, " %d/%d/%c/%c/%s %08x %u\n",
2335 session->mtu, session->mru,
2336 session->recv_seq ? 'R' : '-',
2337 session->send_seq ? 'S' : '-',
2338 session->lns_mode ? "LNS" : "LAC",
2339 session->debug,
2340 jiffies_to_msecs(session->reorder_timeout));
2341 seq_printf(m, " %hu/%hu %llu/%llu/%llu %llu/%llu/%llu\n",
2342 session->nr, session->ns,
2343 (unsigned long long)session->stats.tx_packets,
2344 (unsigned long long)session->stats.tx_bytes,
2345 (unsigned long long)session->stats.tx_errors,
2346 (unsigned long long)session->stats.rx_packets,
2347 (unsigned long long)session->stats.rx_bytes,
2348 (unsigned long long)session->stats.rx_errors);
2349 }
2350
2351 static int pppol2tp_seq_show(struct seq_file *m, void *v)
2352 {
2353 struct pppol2tp_seq_data *pd = v;
2354
2355 /* display header on line 1 */
2356 if (v == SEQ_START_TOKEN) {
2357 seq_puts(m, "PPPoL2TP driver info, " PPPOL2TP_DRV_VERSION "\n");
2358 seq_puts(m, "TUNNEL name, user-data-ok session-count\n");
2359 seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
2360 seq_puts(m, " SESSION name, addr/port src-tid/sid "
2361 "dest-tid/sid state user-data-ok\n");
2362 seq_puts(m, " mtu/mru/rcvseq/sendseq/lns debug reorderto\n");
2363 seq_puts(m, " nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
2364 goto out;
2365 }
2366
2367 /* Show the tunnel or session context.
2368 */
2369 if (pd->session == NULL)
2370 pppol2tp_seq_tunnel_show(m, pd->tunnel);
2371 else
2372 pppol2tp_seq_session_show(m, pd->session);
2373
2374 out:
2375 return 0;
2376 }
2377
2378 static struct seq_operations pppol2tp_seq_ops = {
2379 .start = pppol2tp_seq_start,
2380 .next = pppol2tp_seq_next,
2381 .stop = pppol2tp_seq_stop,
2382 .show = pppol2tp_seq_show,
2383 };
2384
2385 /* Called when our /proc file is opened. We allocate data for use when
2386 * iterating our tunnel / session contexts and store it in the private
2387 * data of the seq_file.
2388 */
2389 static int pppol2tp_proc_open(struct inode *inode, struct file *file)
2390 {
2391 struct seq_file *m;
2392 struct pppol2tp_seq_data *pd;
2393 int ret = 0;
2394
2395 ret = seq_open(file, &pppol2tp_seq_ops);
2396 if (ret < 0)
2397 goto out;
2398
2399 m = file->private_data;
2400
2401 /* Allocate and fill our proc_data for access later */
2402 ret = -ENOMEM;
2403 m->private = kzalloc(sizeof(struct pppol2tp_seq_data), GFP_KERNEL);
2404 if (m->private == NULL)
2405 goto out;
2406
2407 pd = m->private;
2408 ret = 0;
2409
2410 out:
2411 return ret;
2412 }
2413
2414 /* Called when /proc file access completes.
2415 */
2416 static int pppol2tp_proc_release(struct inode *inode, struct file *file)
2417 {
2418 struct seq_file *m = (struct seq_file *)file->private_data;
2419
2420 kfree(m->private);
2421 m->private = NULL;
2422
2423 return seq_release(inode, file);
2424 }
2425
2426 static struct file_operations pppol2tp_proc_fops = {
2427 .owner = THIS_MODULE,
2428 .open = pppol2tp_proc_open,
2429 .read = seq_read,
2430 .llseek = seq_lseek,
2431 .release = pppol2tp_proc_release,
2432 };
2433
2434 static struct proc_dir_entry *pppol2tp_proc;
2435
2436 #endif /* CONFIG_PROC_FS */
2437
2438 /*****************************************************************************
2439 * Init and cleanup
2440 *****************************************************************************/
2441
2442 static struct proto_ops pppol2tp_ops = {
2443 .family = AF_PPPOX,
2444 .owner = THIS_MODULE,
2445 .release = pppol2tp_release,
2446 .bind = sock_no_bind,
2447 .connect = pppol2tp_connect,
2448 .socketpair = sock_no_socketpair,
2449 .accept = sock_no_accept,
2450 .getname = pppol2tp_getname,
2451 .poll = datagram_poll,
2452 .listen = sock_no_listen,
2453 .shutdown = sock_no_shutdown,
2454 .setsockopt = pppol2tp_setsockopt,
2455 .getsockopt = pppol2tp_getsockopt,
2456 .sendmsg = pppol2tp_sendmsg,
2457 .recvmsg = pppol2tp_recvmsg,
2458 .mmap = sock_no_mmap,
2459 .ioctl = pppox_ioctl,
2460 };
2461
2462 static struct pppox_proto pppol2tp_proto = {
2463 .create = pppol2tp_create,
2464 .ioctl = pppol2tp_ioctl
2465 };
2466
2467 static int __init pppol2tp_init(void)
2468 {
2469 int err;
2470
2471 err = proto_register(&pppol2tp_sk_proto, 0);
2472 if (err)
2473 goto out;
2474 err = register_pppox_proto(PX_PROTO_OL2TP, &pppol2tp_proto);
2475 if (err)
2476 goto out_unregister_pppol2tp_proto;
2477
2478 #ifdef CONFIG_PROC_FS
2479 pppol2tp_proc = proc_net_fops_create(&init_net, "pppol2tp", 0,
2480 &pppol2tp_proc_fops);
2481 if (!pppol2tp_proc) {
2482 err = -ENOMEM;
2483 goto out_unregister_pppox_proto;
2484 }
2485 #endif /* CONFIG_PROC_FS */
2486 printk(KERN_INFO "PPPoL2TP kernel driver, %s\n",
2487 PPPOL2TP_DRV_VERSION);
2488
2489 out:
2490 return err;
2491 #ifdef CONFIG_PROC_FS
2492 out_unregister_pppox_proto:
2493 unregister_pppox_proto(PX_PROTO_OL2TP);
2494 #endif
2495 out_unregister_pppol2tp_proto:
2496 proto_unregister(&pppol2tp_sk_proto);
2497 goto out;
2498 }
2499
2500 static void __exit pppol2tp_exit(void)
2501 {
2502 unregister_pppox_proto(PX_PROTO_OL2TP);
2503
2504 #ifdef CONFIG_PROC_FS
2505 remove_proc_entry("pppol2tp", init_net.proc_net);
2506 #endif
2507 proto_unregister(&pppol2tp_sk_proto);
2508 }
2509
2510 module_init(pppol2tp_init);
2511 module_exit(pppol2tp_exit);
2512
2513 MODULE_AUTHOR("Martijn van Oosterhout <kleptog@svana.org>, "
2514 "James Chapman <jchapman@katalix.com>");
2515 MODULE_DESCRIPTION("PPP over L2TP over UDP");
2516 MODULE_LICENSE("GPL");
2517 MODULE_VERSION(PPPOL2TP_DRV_VERSION);
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