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