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