?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
Merge git://git.infradead.org/mtd-2.6
[linux-2.6/zen-sources.git] / drivers / net / pppol2tp.c
blobe98d9773158d287ba1ae35052dca968fc6cf5735
1 /*****************************************************************************
2 * Linux PPP over L2TP (PPPoX/PPPoL2TP) Sockets
3 *
4 * PPPoX --- Generic PPP encapsulation socket family
5 * PPPoL2TP --- PPP over L2TP (RFC 2661)
6 *
7 * Version: 1.0.0
8 *
9 * Authors: Martijn van Oosterhout <kleptog@svana.org>
10 * James Chapman (jchapman@katalix.com)
11 * Contributors:
12 * Michal Ostrowski <mostrows@speakeasy.net>
13 * Arnaldo Carvalho de Melo <acme@xconectiva.com.br>
14 * David S. Miller (davem@redhat.com)
15 *
16 * License:
17 * This program is free software; you can redistribute it and/or
18 * modify it under the terms of the GNU General Public License
19 * as published by the Free Software Foundation; either version
20 * 2 of the License, or (at your option) any later version.
21 *
22 */
23
24 /* This driver handles only L2TP data frames; control frames are handled by a
25 * userspace application.
26 *
27 * To send data in an L2TP session, userspace opens a PPPoL2TP socket and
28 * attaches it to a bound UDP socket with local tunnel_id / session_id and
29 * peer tunnel_id / session_id set. Data can then be sent or received using
30 * regular socket sendmsg() / recvmsg() calls. Kernel parameters of the socket
31 * can be read or modified using ioctl() or [gs]etsockopt() calls.
32 *
33 * When a PPPoL2TP socket is connected with local and peer session_id values
34 * zero, the socket is treated as a special tunnel management socket.
35 *
36 * Here's example userspace code to create a socket for sending/receiving data
37 * over an L2TP session:-
38 *
39 * struct sockaddr_pppol2tp sax;
40 * int fd;
41 * int session_fd;
42 *
43 * fd = socket(AF_PPPOX, SOCK_DGRAM, PX_PROTO_OL2TP);
44 *
45 * sax.sa_family = AF_PPPOX;
46 * sax.sa_protocol = PX_PROTO_OL2TP;
47 * sax.pppol2tp.fd = tunnel_fd; // bound UDP socket
48 * sax.pppol2tp.addr.sin_addr.s_addr = addr->sin_addr.s_addr;
49 * sax.pppol2tp.addr.sin_port = addr->sin_port;
50 * sax.pppol2tp.addr.sin_family = AF_INET;
51 * sax.pppol2tp.s_tunnel = tunnel_id;
52 * sax.pppol2tp.s_session = session_id;
53 * sax.pppol2tp.d_tunnel = peer_tunnel_id;
54 * sax.pppol2tp.d_session = peer_session_id;
55 *
56 * session_fd = connect(fd, (struct sockaddr *)&sax, sizeof(sax));
57 *
58 * A pppd plugin that allows PPP traffic to be carried over L2TP using
59 * this driver is available from the OpenL2TP project at
60 * http://openl2tp.sourceforge.net.
61 */
62
63 #include <linux/module.h>
64 #include <linux/string.h>
65 #include <linux/list.h>
66 #include <asm/uaccess.h>
67
68 #include <linux/kernel.h>
69 #include <linux/spinlock.h>
70 #include <linux/kthread.h>
71 #include <linux/sched.h>
72 #include <linux/slab.h>
73 #include <linux/errno.h>
74 #include <linux/jiffies.h>
75
76 #include <linux/netdevice.h>
77 #include <linux/net.h>
78 #include <linux/inetdevice.h>
79 #include <linux/skbuff.h>
80 #include <linux/init.h>
81 #include <linux/ip.h>
82 #include <linux/udp.h>
83 #include <linux/if_pppox.h>
84 #include <linux/if_pppol2tp.h>
85 #include <net/sock.h>
86 #include <linux/ppp_channel.h>
87 #include <linux/ppp_defs.h>
88 #include <linux/if_ppp.h>
89 #include <linux/file.h>
90 #include <linux/hash.h>
91 #include <linux/sort.h>
92 #include <linux/proc_fs.h>
93 #include <net/net_namespace.h>
94 #include <net/dst.h>
95 #include <net/ip.h>
96 #include <net/udp.h>
97 #include <net/xfrm.h>
98
99 #include <asm/byteorder.h>
100 #include <asm/atomic.h>
101
102
103 #define PPPOL2TP_DRV_VERSION "V1.0"
104
105 /* L2TP header constants */
106 #define L2TP_HDRFLAG_T 0x8000
107 #define L2TP_HDRFLAG_L 0x4000
108 #define L2TP_HDRFLAG_S 0x0800
109 #define L2TP_HDRFLAG_O 0x0200
110 #define L2TP_HDRFLAG_P 0x0100
111
112 #define L2TP_HDR_VER_MASK 0x000F
113 #define L2TP_HDR_VER 0x0002
114
115 /* Space for UDP, L2TP and PPP headers */
116 #define PPPOL2TP_HEADER_OVERHEAD 40
117
118 /* Just some random numbers */
119 #define L2TP_TUNNEL_MAGIC 0x42114DDA
120 #define L2TP_SESSION_MAGIC 0x0C04EB7D
121
122 #define PPPOL2TP_HASH_BITS 4
123 #define PPPOL2TP_HASH_SIZE (1 << PPPOL2TP_HASH_BITS)
124
125 /* Default trace flags */
126 #define PPPOL2TP_DEFAULT_DEBUG_FLAGS 0
127
128 #define PRINTK(_mask, _type, _lvl, _fmt, args...) \
129 do { \
130 if ((_mask) & (_type)) \
131 printk(_lvl "PPPOL2TP: " _fmt, ##args); \
132 } while(0)
133
134 /* Number of bytes to build transmit L2TP headers.
135 * Unfortunately the size is different depending on whether sequence numbers
136 * are enabled.
137 */
138 #define PPPOL2TP_L2TP_HDR_SIZE_SEQ 10
139 #define PPPOL2TP_L2TP_HDR_SIZE_NOSEQ 6
140
141 struct pppol2tp_tunnel;
142
143 /* Describes a session. It is the sk_user_data field in the PPPoL2TP
144 * socket. Contains information to determine incoming packets and transmit
145 * outgoing ones.
146 */
147 struct pppol2tp_session
148 {
149 int magic; /* should be
150 * L2TP_SESSION_MAGIC */
151 int owner; /* pid that opened the socket */
152
153 struct sock *sock; /* Pointer to the session
154 * PPPoX socket */
155 struct sock *tunnel_sock; /* Pointer to the tunnel UDP
156 * socket */
157
158 struct pppol2tp_addr tunnel_addr; /* Description of tunnel */
159
160 struct pppol2tp_tunnel *tunnel; /* back pointer to tunnel
161 * context */
162
163 char name[20]; /* "sess xxxxx/yyyyy", where
164 * x=tunnel_id, y=session_id */
165 int mtu;
166 int mru;
167 int flags; /* accessed by PPPIOCGFLAGS.
168 * Unused. */
169 unsigned recv_seq:1; /* expect receive packets with
170 * sequence numbers? */
171 unsigned send_seq:1; /* send packets with sequence
172 * numbers? */
173 unsigned lns_mode:1; /* behave as LNS? LAC enables
174 * sequence numbers under
175 * control of LNS. */
176 int debug; /* bitmask of debug message
177 * categories */
178 int reorder_timeout; /* configured reorder timeout
179 * (in jiffies) */
180 u16 nr; /* session NR state (receive) */
181 u16 ns; /* session NR state (send) */
182 struct sk_buff_head reorder_q; /* receive reorder queue */
183 struct pppol2tp_ioc_stats stats;
184 struct hlist_node hlist; /* Hash list node */
185 };
186
187 /* The sk_user_data field of the tunnel's UDP socket. It contains info to track
188 * all the associated sessions so incoming packets can be sorted out
189 */
190 struct pppol2tp_tunnel
191 {
192 int magic; /* Should be L2TP_TUNNEL_MAGIC */
193 rwlock_t hlist_lock; /* protect session_hlist */
194 struct hlist_head session_hlist[PPPOL2TP_HASH_SIZE];
195 /* hashed list of sessions,
196 * hashed by id */
197 int debug; /* bitmask of debug message
198 * categories */
199 char name[12]; /* "tunl xxxxx" */
200 struct pppol2tp_ioc_stats stats;
201
202 void (*old_sk_destruct)(struct sock *);
203
204 struct sock *sock; /* Parent socket */
205 struct list_head list; /* Keep a list of all open
206 * prepared sockets */
207
208 atomic_t ref_count;
209 };
210
211 /* Private data stored for received packets in the skb.
212 */
213 struct pppol2tp_skb_cb {
214 u16 ns;
215 u16 nr;
216 u16 has_seq;
217 u16 length;
218 unsigned long expires;
219 };
220
221 #define PPPOL2TP_SKB_CB(skb) ((struct pppol2tp_skb_cb *) &skb->cb[sizeof(struct inet_skb_parm)])
222
223 static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb);
224 static void pppol2tp_tunnel_free(struct pppol2tp_tunnel *tunnel);
225
226 static atomic_t pppol2tp_tunnel_count;
227 static atomic_t pppol2tp_session_count;
228 static struct ppp_channel_ops pppol2tp_chan_ops = { pppol2tp_xmit , NULL };
229 static struct proto_ops pppol2tp_ops;
230 static LIST_HEAD(pppol2tp_tunnel_list);
231 static DEFINE_RWLOCK(pppol2tp_tunnel_list_lock);
232
233 /* Helpers to obtain tunnel/session contexts from sockets.
234 */
235 static inline struct pppol2tp_session *pppol2tp_sock_to_session(struct sock *sk)
236 {
237 struct pppol2tp_session *session;
238
239 if (sk == NULL)
240 return NULL;
241
242 sock_hold(sk);
243 session = (struct pppol2tp_session *)(sk->sk_user_data);
244 if (session == NULL) {
245 sock_put(sk);
246 goto out;
247 }
248
249 BUG_ON(session->magic != L2TP_SESSION_MAGIC);
250 out:
251 return session;
252 }
253
254 static inline struct pppol2tp_tunnel *pppol2tp_sock_to_tunnel(struct sock *sk)
255 {
256 struct pppol2tp_tunnel *tunnel;
257
258 if (sk == NULL)
259 return NULL;
260
261 sock_hold(sk);
262 tunnel = (struct pppol2tp_tunnel *)(sk->sk_user_data);
263 if (tunnel == NULL) {
264 sock_put(sk);
265 goto out;
266 }
267
268 BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);
269 out:
270 return tunnel;
271 }
272
273 /* Tunnel reference counts. Incremented per session that is added to
274 * the tunnel.
275 */
276 static inline void pppol2tp_tunnel_inc_refcount(struct pppol2tp_tunnel *tunnel)
277 {
278 atomic_inc(&tunnel->ref_count);
279 }
280
281 static inline void pppol2tp_tunnel_dec_refcount(struct pppol2tp_tunnel *tunnel)
282 {
283 if (atomic_dec_and_test(&tunnel->ref_count))
284 pppol2tp_tunnel_free(tunnel);
285 }
286
287 /* Session hash list.
288 * The session_id SHOULD be random according to RFC2661, but several
289 * L2TP implementations (Cisco and Microsoft) use incrementing
290 * session_ids. So we do a real hash on the session_id, rather than a
291 * simple bitmask.
292 */
293 static inline struct hlist_head *
294 pppol2tp_session_id_hash(struct pppol2tp_tunnel *tunnel, u16 session_id)
295 {
296 unsigned long hash_val = (unsigned long) session_id;
297 return &tunnel->session_hlist[hash_long(hash_val, PPPOL2TP_HASH_BITS)];
298 }
299
300 /* Lookup a session by id
301 */
302 static struct pppol2tp_session *
303 pppol2tp_session_find(struct pppol2tp_tunnel *tunnel, u16 session_id)
304 {
305 struct hlist_head *session_list =
306 pppol2tp_session_id_hash(tunnel, session_id);
307 struct pppol2tp_session *session;
308 struct hlist_node *walk;
309
310 read_lock_bh(&tunnel->hlist_lock);
311 hlist_for_each_entry(session, walk, session_list, hlist) {
312 if (session->tunnel_addr.s_session == session_id) {
313 read_unlock_bh(&tunnel->hlist_lock);
314 return session;
315 }
316 }
317 read_unlock_bh(&tunnel->hlist_lock);
318
319 return NULL;
320 }
321
322 /* Lookup a tunnel by id
323 */
324 static struct pppol2tp_tunnel *pppol2tp_tunnel_find(u16 tunnel_id)
325 {
326 struct pppol2tp_tunnel *tunnel = NULL;
327
328 read_lock_bh(&pppol2tp_tunnel_list_lock);
329 list_for_each_entry(tunnel, &pppol2tp_tunnel_list, list) {
330 if (tunnel->stats.tunnel_id == tunnel_id) {
331 read_unlock_bh(&pppol2tp_tunnel_list_lock);
332 return tunnel;
333 }
334 }
335 read_unlock_bh(&pppol2tp_tunnel_list_lock);
336
337 return NULL;
338 }
339
340 /*****************************************************************************
341 * Receive data handling
342 *****************************************************************************/
343
344 /* Queue a skb in order. We come here only if the skb has an L2TP sequence
345 * number.
346 */
347 static void pppol2tp_recv_queue_skb(struct pppol2tp_session *session, struct sk_buff *skb)
348 {
349 struct sk_buff *skbp;
350 struct sk_buff *tmp;
351 u16 ns = PPPOL2TP_SKB_CB(skb)->ns;
352
353 spin_lock_bh(&session->reorder_q.lock);
354 skb_queue_walk_safe(&session->reorder_q, skbp, tmp) {
355 if (PPPOL2TP_SKB_CB(skbp)->ns > ns) {
356 __skb_queue_before(&session->reorder_q, skbp, skb);
357 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
358 "%s: pkt %hu, inserted before %hu, reorder_q len=%d\n",
359 session->name, ns, PPPOL2TP_SKB_CB(skbp)->ns,
360 skb_queue_len(&session->reorder_q));
361 session->stats.rx_oos_packets++;
362 goto out;
363 }
364 }
365
366 __skb_queue_tail(&session->reorder_q, skb);
367
368 out:
369 spin_unlock_bh(&session->reorder_q.lock);
370 }
371
372 /* Dequeue a single skb.
373 */
374 static void pppol2tp_recv_dequeue_skb(struct pppol2tp_session *session, struct sk_buff *skb)
375 {
376 struct pppol2tp_tunnel *tunnel = session->tunnel;
377 int length = PPPOL2TP_SKB_CB(skb)->length;
378 struct sock *session_sock = NULL;
379
380 /* We're about to requeue the skb, so return resources
381 * to its current owner (a socket receive buffer).
382 */
383 skb_orphan(skb);
384
385 tunnel->stats.rx_packets++;
386 tunnel->stats.rx_bytes += length;
387 session->stats.rx_packets++;
388 session->stats.rx_bytes += length;
389
390 if (PPPOL2TP_SKB_CB(skb)->has_seq) {
391 /* Bump our Nr */
392 session->nr++;
393 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
394 "%s: updated nr to %hu\n", session->name, session->nr);
395 }
396
397 /* If the socket is bound, send it in to PPP's input queue. Otherwise
398 * queue it on the session socket.
399 */
400 session_sock = session->sock;
401 if (session_sock->sk_state & PPPOX_BOUND) {
402 struct pppox_sock *po;
403 PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
404 "%s: recv %d byte data frame, passing to ppp\n",
405 session->name, length);
406
407 /* We need to forget all info related to the L2TP packet
408 * gathered in the skb as we are going to reuse the same
409 * skb for the inner packet.
410 * Namely we need to:
411 * - reset xfrm (IPSec) information as it applies to
412 * the outer L2TP packet and not to the inner one
413 * - release the dst to force a route lookup on the inner
414 * IP packet since skb->dst currently points to the dst
415 * of the UDP tunnel
416 * - reset netfilter information as it doesn't apply
417 * to the inner packet either
418 */
419 secpath_reset(skb);
420 dst_release(skb->dst);
421 skb->dst = NULL;
422 nf_reset(skb);
423
424 po = pppox_sk(session_sock);
425 ppp_input(&po->chan, skb);
426 } else {
427 PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_INFO,
428 "%s: socket not bound\n", session->name);
429
430 /* Not bound. Nothing we can do, so discard. */
431 session->stats.rx_errors++;
432 kfree_skb(skb);
433 }
434
435 sock_put(session->sock);
436 }
437
438 /* Dequeue skbs from the session's reorder_q, subject to packet order.
439 * Skbs that have been in the queue for too long are simply discarded.
440 */
441 static void pppol2tp_recv_dequeue(struct pppol2tp_session *session)
442 {
443 struct sk_buff *skb;
444 struct sk_buff *tmp;
445
446 /* If the pkt at the head of the queue has the nr that we
447 * expect to send up next, dequeue it and any other
448 * in-sequence packets behind it.
449 */
450 spin_lock_bh(&session->reorder_q.lock);
451 skb_queue_walk_safe(&session->reorder_q, skb, tmp) {
452 if (time_after(jiffies, PPPOL2TP_SKB_CB(skb)->expires)) {
453 session->stats.rx_seq_discards++;
454 session->stats.rx_errors++;
455 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
456 "%s: oos pkt %hu len %d discarded (too old), "
457 "waiting for %hu, reorder_q_len=%d\n",
458 session->name, PPPOL2TP_SKB_CB(skb)->ns,
459 PPPOL2TP_SKB_CB(skb)->length, session->nr,
460 skb_queue_len(&session->reorder_q));
461 __skb_unlink(skb, &session->reorder_q);
462 kfree_skb(skb);
463 sock_put(session->sock);
464 continue;
465 }
466
467 if (PPPOL2TP_SKB_CB(skb)->has_seq) {
468 if (PPPOL2TP_SKB_CB(skb)->ns != session->nr) {
469 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
470 "%s: holding oos pkt %hu len %d, "
471 "waiting for %hu, reorder_q_len=%d\n",
472 session->name, PPPOL2TP_SKB_CB(skb)->ns,
473 PPPOL2TP_SKB_CB(skb)->length, session->nr,
474 skb_queue_len(&session->reorder_q));
475 goto out;
476 }
477 }
478 __skb_unlink(skb, &session->reorder_q);
479
480 /* Process the skb. We release the queue lock while we
481 * do so to let other contexts process the queue.
482 */
483 spin_unlock_bh(&session->reorder_q.lock);
484 pppol2tp_recv_dequeue_skb(session, skb);
485 spin_lock_bh(&session->reorder_q.lock);
486 }
487
488 out:
489 spin_unlock_bh(&session->reorder_q.lock);
490 }
491
492 /* Internal receive frame. Do the real work of receiving an L2TP data frame
493 * here. The skb is not on a list when we get here.
494 * Returns 0 if the packet was a data packet and was successfully passed on.
495 * Returns 1 if the packet was not a good data packet and could not be
496 * forwarded. All such packets are passed up to userspace to deal with.
497 */
498 static int pppol2tp_recv_core(struct sock *sock, struct sk_buff *skb)
499 {
500 struct pppol2tp_session *session = NULL;
501 struct pppol2tp_tunnel *tunnel;
502 unsigned char *ptr, *optr;
503 u16 hdrflags;
504 u16 tunnel_id, session_id;
505 int length;
506 int offset;
507
508 tunnel = pppol2tp_sock_to_tunnel(sock);
509 if (tunnel == NULL)
510 goto no_tunnel;
511
512 /* UDP always verifies the packet length. */
513 __skb_pull(skb, sizeof(struct udphdr));
514
515 /* Short packet? */
516 if (!pskb_may_pull(skb, 12)) {
517 PRINTK(tunnel->debug, PPPOL2TP_MSG_DATA, KERN_INFO,
518 "%s: recv short packet (len=%d)\n", tunnel->name, skb->len);
519 goto error;
520 }
521
522 /* Point to L2TP header */
523 optr = ptr = skb->data;
524
525 /* Get L2TP header flags */
526 hdrflags = ntohs(*(__be16*)ptr);
527
528 /* Trace packet contents, if enabled */
529 if (tunnel->debug & PPPOL2TP_MSG_DATA) {
530 length = min(16u, skb->len);
531 if (!pskb_may_pull(skb, length))
532 goto error;
533
534 printk(KERN_DEBUG "%s: recv: ", tunnel->name);
535
536 offset = 0;
537 do {
538 printk(" %02X", ptr[offset]);
539 } while (++offset < length);
540
541 printk("\n");
542 }
543
544 /* Get length of L2TP packet */
545 length = skb->len;
546
547 /* If type is control packet, it is handled by userspace. */
548 if (hdrflags & L2TP_HDRFLAG_T) {
549 PRINTK(tunnel->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
550 "%s: recv control packet, len=%d\n", tunnel->name, length);
551 goto error;
552 }
553
554 /* Skip flags */
555 ptr += 2;
556
557 /* If length is present, skip it */
558 if (hdrflags & L2TP_HDRFLAG_L)
559 ptr += 2;
560
561 /* Extract tunnel and session ID */
562 tunnel_id = ntohs(*(__be16 *) ptr);
563 ptr += 2;
564 session_id = ntohs(*(__be16 *) ptr);
565 ptr += 2;
566
567 /* Find the session context */
568 session = pppol2tp_session_find(tunnel, session_id);
569 if (!session) {
570 /* Not found? Pass to userspace to deal with */
571 PRINTK(tunnel->debug, PPPOL2TP_MSG_DATA, KERN_INFO,
572 "%s: no socket found (%hu/%hu). Passing up.\n",
573 tunnel->name, tunnel_id, session_id);
574 goto error;
575 }
576 sock_hold(session->sock);
577
578 /* The ref count on the socket was increased by the above call since
579 * we now hold a pointer to the session. Take care to do sock_put()
580 * when exiting this function from now on...
581 */
582
583 /* Handle the optional sequence numbers. If we are the LAC,
584 * enable/disable sequence numbers under the control of the LNS. If
585 * no sequence numbers present but we were expecting them, discard
586 * frame.
587 */
588 if (hdrflags & L2TP_HDRFLAG_S) {
589 u16 ns, nr;
590 ns = ntohs(*(__be16 *) ptr);
591 ptr += 2;
592 nr = ntohs(*(__be16 *) ptr);
593 ptr += 2;
594
595 /* Received a packet with sequence numbers. If we're the LNS,
596 * check if we sre sending sequence numbers and if not,
597 * configure it so.
598 */
599 if ((!session->lns_mode) && (!session->send_seq)) {
600 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_INFO,
601 "%s: requested to enable seq numbers by LNS\n",
602 session->name);
603 session->send_seq = -1;
604 }
605
606 /* Store L2TP info in the skb */
607 PPPOL2TP_SKB_CB(skb)->ns = ns;
608 PPPOL2TP_SKB_CB(skb)->nr = nr;
609 PPPOL2TP_SKB_CB(skb)->has_seq = 1;
610
611 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
612 "%s: recv data ns=%hu, nr=%hu, session nr=%hu\n",
613 session->name, ns, nr, session->nr);
614 } else {
615 /* No sequence numbers.
616 * If user has configured mandatory sequence numbers, discard.
617 */
618 if (session->recv_seq) {
619 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_WARNING,
620 "%s: recv data has no seq numbers when required. "
621 "Discarding\n", session->name);
622 session->stats.rx_seq_discards++;
623 goto discard;
624 }
625
626 /* If we're the LAC and we're sending sequence numbers, the
627 * LNS has requested that we no longer send sequence numbers.
628 * If we're the LNS and we're sending sequence numbers, the
629 * LAC is broken. Discard the frame.
630 */
631 if ((!session->lns_mode) && (session->send_seq)) {
632 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_INFO,
633 "%s: requested to disable seq numbers by LNS\n",
634 session->name);
635 session->send_seq = 0;
636 } else if (session->send_seq) {
637 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_WARNING,
638 "%s: recv data has no seq numbers when required. "
639 "Discarding\n", session->name);
640 session->stats.rx_seq_discards++;
641 goto discard;
642 }
643
644 /* Store L2TP info in the skb */
645 PPPOL2TP_SKB_CB(skb)->has_seq = 0;
646 }
647
648 /* If offset bit set, skip it. */
649 if (hdrflags & L2TP_HDRFLAG_O) {
650 offset = ntohs(*(__be16 *)ptr);
651 ptr += 2 + offset;
652 }
653
654 offset = ptr - optr;
655 if (!pskb_may_pull(skb, offset))
656 goto discard;
657
658 __skb_pull(skb, offset);
659
660 /* Skip PPP header, if present. In testing, Microsoft L2TP clients
661 * don't send the PPP header (PPP header compression enabled), but
662 * other clients can include the header. So we cope with both cases
663 * here. The PPP header is always FF03 when using L2TP.
664 *
665 * Note that skb->data[] isn't dereferenced from a u16 ptr here since
666 * the field may be unaligned.
667 */
668 if (!pskb_may_pull(skb, 2))
669 goto discard;
670
671 if ((skb->data[0] == 0xff) && (skb->data[1] == 0x03))
672 skb_pull(skb, 2);
673
674 /* Prepare skb for adding to the session's reorder_q. Hold
675 * packets for max reorder_timeout or 1 second if not
676 * reordering.
677 */
678 PPPOL2TP_SKB_CB(skb)->length = length;
679 PPPOL2TP_SKB_CB(skb)->expires = jiffies +
680 (session->reorder_timeout ? session->reorder_timeout : HZ);
681
682 /* Add packet to the session's receive queue. Reordering is done here, if
683 * enabled. Saved L2TP protocol info is stored in skb->sb[].
684 */
685 if (PPPOL2TP_SKB_CB(skb)->has_seq) {
686 if (session->reorder_timeout != 0) {
687 /* Packet reordering enabled. Add skb to session's
688 * reorder queue, in order of ns.
689 */
690 pppol2tp_recv_queue_skb(session, skb);
691 } else {
692 /* Packet reordering disabled. Discard out-of-sequence
693 * packets
694 */
695 if (PPPOL2TP_SKB_CB(skb)->ns != session->nr) {
696 session->stats.rx_seq_discards++;
697 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
698 "%s: oos pkt %hu len %d discarded, "
699 "waiting for %hu, reorder_q_len=%d\n",
700 session->name, PPPOL2TP_SKB_CB(skb)->ns,
701 PPPOL2TP_SKB_CB(skb)->length, session->nr,
702 skb_queue_len(&session->reorder_q));
703 goto discard;
704 }
705 skb_queue_tail(&session->reorder_q, skb);
706 }
707 } else {
708 /* No sequence numbers. Add the skb to the tail of the
709 * reorder queue. This ensures that it will be
710 * delivered after all previous sequenced skbs.
711 */
712 skb_queue_tail(&session->reorder_q, skb);
713 }
714
715 /* Try to dequeue as many skbs from reorder_q as we can. */
716 pppol2tp_recv_dequeue(session);
717
718 return 0;
719
720 discard:
721 session->stats.rx_errors++;
722 kfree_skb(skb);
723 sock_put(session->sock);
724 sock_put(sock);
725
726 return 0;
727
728 error:
729 /* Put UDP header back */
730 __skb_push(skb, sizeof(struct udphdr));
731 sock_put(sock);
732
733 no_tunnel:
734 return 1;
735 }
736
737 /* UDP encapsulation receive handler. See net/ipv4/udp.c.
738 * Return codes:
739 * 0 : success.
740 * <0: error
741 * >0: skb should be passed up to userspace as UDP.
742 */
743 static int pppol2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
744 {
745 struct pppol2tp_tunnel *tunnel;
746
747 tunnel = pppol2tp_sock_to_tunnel(sk);
748 if (tunnel == NULL)
749 goto pass_up;
750
751 PRINTK(tunnel->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
752 "%s: received %d bytes\n", tunnel->name, skb->len);
753
754 if (pppol2tp_recv_core(sk, skb))
755 goto pass_up_put;
756
757 sock_put(sk);
758 return 0;
759
760 pass_up_put:
761 sock_put(sk);
762 pass_up:
763 return 1;
764 }
765
766 /* Receive message. This is the recvmsg for the PPPoL2TP socket.
767 */
768 static int pppol2tp_recvmsg(struct kiocb *iocb, struct socket *sock,
769 struct msghdr *msg, size_t len,
770 int flags)
771 {
772 int err;
773 struct sk_buff *skb;
774 struct sock *sk = sock->sk;
775
776 err = -EIO;
777 if (sk->sk_state & PPPOX_BOUND)
778 goto end;
779
780 msg->msg_namelen = 0;
781
782 err = 0;
783 skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
784 flags & MSG_DONTWAIT, &err);
785 if (!skb)
786 goto end;
787
788 if (len > skb->len)
789 len = skb->len;
790 else if (len < skb->len)
791 msg->msg_flags |= MSG_TRUNC;
792
793 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len);
794 if (likely(err == 0))
795 err = len;
796
797 kfree_skb(skb);
798 end:
799 return err;
800 }
801
802 /************************************************************************
803 * Transmit handling
804 ***********************************************************************/
805
806 /* Tell how big L2TP headers are for a particular session. This
807 * depends on whether sequence numbers are being used.
808 */
809 static inline int pppol2tp_l2tp_header_len(struct pppol2tp_session *session)
810 {
811 if (session->send_seq)
812 return PPPOL2TP_L2TP_HDR_SIZE_SEQ;
813
814 return PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
815 }
816
817 /* Build an L2TP header for the session into the buffer provided.
818 */
819 static void pppol2tp_build_l2tp_header(struct pppol2tp_session *session,
820 void *buf)
821 {
822 __be16 *bufp = buf;
823 u16 flags = L2TP_HDR_VER;
824
825 if (session->send_seq)
826 flags |= L2TP_HDRFLAG_S;
827
828 /* Setup L2TP header.
829 * FIXME: Can this ever be unaligned? Is direct dereferencing of
830 * 16-bit header fields safe here for all architectures?
831 */
832 *bufp++ = htons(flags);
833 *bufp++ = htons(session->tunnel_addr.d_tunnel);
834 *bufp++ = htons(session->tunnel_addr.d_session);
835 if (session->send_seq) {
836 *bufp++ = htons(session->ns);
837 *bufp++ = 0;
838 session->ns++;
839 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
840 "%s: updated ns to %hu\n", session->name, session->ns);
841 }
842 }
843
844 /* This is the sendmsg for the PPPoL2TP pppol2tp_session socket. We come here
845 * when a user application does a sendmsg() on the session socket. L2TP and
846 * PPP headers must be inserted into the user's data.
847 */
848 static int pppol2tp_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
849 size_t total_len)
850 {
851 static const unsigned char ppph[2] = { 0xff, 0x03 };
852 struct sock *sk = sock->sk;
853 struct inet_sock *inet;
854 __wsum csum = 0;
855 struct sk_buff *skb;
856 int error;
857 int hdr_len;
858 struct pppol2tp_session *session;
859 struct pppol2tp_tunnel *tunnel;
860 struct udphdr *uh;
861 unsigned int len;
862
863 error = -ENOTCONN;
864 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
865 goto error;
866
867 /* Get session and tunnel contexts */
868 error = -EBADF;
869 session = pppol2tp_sock_to_session(sk);
870 if (session == NULL)
871 goto error;
872
873 tunnel = pppol2tp_sock_to_tunnel(session->tunnel_sock);
874 if (tunnel == NULL)
875 goto error_put_sess;
876
877 /* What header length is configured for this session? */
878 hdr_len = pppol2tp_l2tp_header_len(session);
879
880 /* Allocate a socket buffer */
881 error = -ENOMEM;
882 skb = sock_wmalloc(sk, NET_SKB_PAD + sizeof(struct iphdr) +
883 sizeof(struct udphdr) + hdr_len +
884 sizeof(ppph) + total_len,
885 0, GFP_KERNEL);
886 if (!skb)
887 goto error_put_sess_tun;
888
889 /* Reserve space for headers. */
890 skb_reserve(skb, NET_SKB_PAD);
891 skb_reset_network_header(skb);
892 skb_reserve(skb, sizeof(struct iphdr));
893 skb_reset_transport_header(skb);
894
895 /* Build UDP header */
896 inet = inet_sk(session->tunnel_sock);
897 uh = (struct udphdr *) skb->data;
898 uh->source = inet->sport;
899 uh->dest = inet->dport;
900 uh->len = htons(hdr_len + sizeof(ppph) + total_len);
901 uh->check = 0;
902 skb_put(skb, sizeof(struct udphdr));
903
904 /* Build L2TP header */
905 pppol2tp_build_l2tp_header(session, skb->data);
906 skb_put(skb, hdr_len);
907
908 /* Add PPP header */
909 skb->data[0] = ppph[0];
910 skb->data[1] = ppph[1];
911 skb_put(skb, 2);
912
913 /* Copy user data into skb */
914 error = memcpy_fromiovec(skb->data, m->msg_iov, total_len);
915 if (error < 0) {
916 kfree_skb(skb);
917 goto error_put_sess_tun;
918 }
919 skb_put(skb, total_len);
920
921 /* Calculate UDP checksum if configured to do so */
922 if (session->tunnel_sock->sk_no_check != UDP_CSUM_NOXMIT)
923 csum = udp_csum_outgoing(sk, skb);
924
925 /* Debug */
926 if (session->send_seq)
927 PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
928 "%s: send %Zd bytes, ns=%hu\n", session->name,
929 total_len, session->ns - 1);
930 else
931 PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
932 "%s: send %Zd bytes\n", session->name, total_len);
933
934 if (session->debug & PPPOL2TP_MSG_DATA) {
935 int i;
936 unsigned char *datap = skb->data;
937
938 printk(KERN_DEBUG "%s: xmit:", session->name);
939 for (i = 0; i < total_len; i++) {
940 printk(" %02X", *datap++);
941 if (i == 15) {
942 printk(" ...");
943 break;
944 }
945 }
946 printk("\n");
947 }
948
949 /* Queue the packet to IP for output */
950 len = skb->len;
951 error = ip_queue_xmit(skb, 1);
952
953 /* Update stats */
954 if (error >= 0) {
955 tunnel->stats.tx_packets++;
956 tunnel->stats.tx_bytes += len;
957 session->stats.tx_packets++;
958 session->stats.tx_bytes += len;
959 } else {
960 tunnel->stats.tx_errors++;
961 session->stats.tx_errors++;
962 }
963
964 return error;
965
966 error_put_sess_tun:
967 sock_put(session->tunnel_sock);
968 error_put_sess:
969 sock_put(sk);
970 error:
971 return error;
972 }
973
974 /* Automatically called when the skb is freed.
975 */
976 static void pppol2tp_sock_wfree(struct sk_buff *skb)
977 {
978 sock_put(skb->sk);
979 }
980
981 /* For data skbs that we transmit, we associate with the tunnel socket
982 * but don't do accounting.
983 */
984 static inline void pppol2tp_skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
985 {
986 sock_hold(sk);
987 skb->sk = sk;
988 skb->destructor = pppol2tp_sock_wfree;
989 }
990
991 /* Transmit function called by generic PPP driver. Sends PPP frame
992 * over PPPoL2TP socket.
993 *
994 * This is almost the same as pppol2tp_sendmsg(), but rather than
995 * being called with a msghdr from userspace, it is called with a skb
996 * from the kernel.
997 *
998 * The supplied skb from ppp doesn't have enough headroom for the
999 * insertion of L2TP, UDP and IP headers so we need to allocate more
1000 * headroom in the skb. This will create a cloned skb. But we must be
1001 * careful in the error case because the caller will expect to free
1002 * the skb it supplied, not our cloned skb. So we take care to always
1003 * leave the original skb unfreed if we return an error.
1004 */
1005 static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
1006 {
1007 static const u8 ppph[2] = { 0xff, 0x03 };
1008 struct sock *sk = (struct sock *) chan->private;
1009 struct sock *sk_tun;
1010 int hdr_len;
1011 struct pppol2tp_session *session;
1012 struct pppol2tp_tunnel *tunnel;
1013 int rc;
1014 int headroom;
1015 int data_len = skb->len;
1016 struct inet_sock *inet;
1017 __wsum csum = 0;
1018 struct udphdr *uh;
1019 unsigned int len;
1020 int old_headroom;
1021 int new_headroom;
1022
1023 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
1024 goto abort;
1025
1026 /* Get session and tunnel contexts from the socket */
1027 session = pppol2tp_sock_to_session(sk);
1028 if (session == NULL)
1029 goto abort;
1030
1031 sk_tun = session->tunnel_sock;
1032 if (sk_tun == NULL)
1033 goto abort_put_sess;
1034 tunnel = pppol2tp_sock_to_tunnel(sk_tun);
1035 if (tunnel == NULL)
1036 goto abort_put_sess;
1037
1038 /* What header length is configured for this session? */
1039 hdr_len = pppol2tp_l2tp_header_len(session);
1040
1041 /* Check that there's enough headroom in the skb to insert IP,
1042 * UDP and L2TP and PPP headers. If not enough, expand it to
1043 * make room. Adjust truesize.
1044 */
1045 headroom = NET_SKB_PAD + sizeof(struct iphdr) +
1046 sizeof(struct udphdr) + hdr_len + sizeof(ppph);
1047 old_headroom = skb_headroom(skb);
1048 if (skb_cow_head(skb, headroom))
1049 goto abort_put_sess_tun;
1050
1051 new_headroom = skb_headroom(skb);
1052 skb_orphan(skb);
1053 skb->truesize += new_headroom - old_headroom;
1054
1055 /* Setup PPP header */
1056 __skb_push(skb, sizeof(ppph));
1057 skb->data[0] = ppph[0];
1058 skb->data[1] = ppph[1];
1059
1060 /* Setup L2TP header */
1061 pppol2tp_build_l2tp_header(session, __skb_push(skb, hdr_len));
1062
1063 /* Setup UDP header */
1064 inet = inet_sk(sk_tun);
1065 __skb_push(skb, sizeof(*uh));
1066 skb_reset_transport_header(skb);
1067 uh = udp_hdr(skb);
1068 uh->source = inet->sport;
1069 uh->dest = inet->dport;
1070 uh->len = htons(sizeof(struct udphdr) + hdr_len + sizeof(ppph) + data_len);
1071 uh->check = 0;
1072
1073 /* *BROKEN* Calculate UDP checksum if configured to do so */
1074 if (sk_tun->sk_no_check != UDP_CSUM_NOXMIT)
1075 csum = udp_csum_outgoing(sk_tun, skb);
1076
1077 /* Debug */
1078 if (session->send_seq)
1079 PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
1080 "%s: send %d bytes, ns=%hu\n", session->name,
1081 data_len, session->ns - 1);
1082 else
1083 PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
1084 "%s: send %d bytes\n", session->name, data_len);
1085
1086 if (session->debug & PPPOL2TP_MSG_DATA) {
1087 int i;
1088 unsigned char *datap = skb->data;
1089
1090 printk(KERN_DEBUG "%s: xmit:", session->name);
1091 for (i = 0; i < data_len; i++) {
1092 printk(" %02X", *datap++);
1093 if (i == 31) {
1094 printk(" ...");
1095 break;
1096 }
1097 }
1098 printk("\n");
1099 }
1100
1101 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1102 IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED |
1103 IPSKB_REROUTED);
1104 nf_reset(skb);
1105
1106 /* Get routing info from the tunnel socket */
1107 dst_release(skb->dst);
1108 skb->dst = dst_clone(__sk_dst_get(sk_tun));
1109 pppol2tp_skb_set_owner_w(skb, sk_tun);
1110
1111 /* Queue the packet to IP for output */
1112 len = skb->len;
1113 rc = ip_queue_xmit(skb, 1);
1114
1115 /* Update stats */
1116 if (rc >= 0) {
1117 tunnel->stats.tx_packets++;
1118 tunnel->stats.tx_bytes += len;
1119 session->stats.tx_packets++;
1120 session->stats.tx_bytes += len;
1121 } else {
1122 tunnel->stats.tx_errors++;
1123 session->stats.tx_errors++;
1124 }
1125
1126 sock_put(sk_tun);
1127 sock_put(sk);
1128 return 1;
1129
1130 abort_put_sess_tun:
1131 sock_put(sk_tun);
1132 abort_put_sess:
1133 sock_put(sk);
1134 abort:
1135 /* Free the original skb */
1136 kfree_skb(skb);
1137 return 1;
1138 }
1139
1140 /*****************************************************************************
1141 * Session (and tunnel control) socket create/destroy.
1142 *****************************************************************************/
1143
1144 /* When the tunnel UDP socket is closed, all the attached sockets need to go
1145 * too.
1146 */
1147 static void pppol2tp_tunnel_closeall(struct pppol2tp_tunnel *tunnel)
1148 {
1149 int hash;
1150 struct hlist_node *walk;
1151 struct hlist_node *tmp;
1152 struct pppol2tp_session *session;
1153 struct sock *sk;
1154
1155 if (tunnel == NULL)
1156 BUG();
1157
1158 PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1159 "%s: closing all sessions...\n", tunnel->name);
1160
1161 write_lock_bh(&tunnel->hlist_lock);
1162 for (hash = 0; hash < PPPOL2TP_HASH_SIZE; hash++) {
1163 again:
1164 hlist_for_each_safe(walk, tmp, &tunnel->session_hlist[hash]) {
1165 struct sk_buff *skb;
1166
1167 session = hlist_entry(walk, struct pppol2tp_session, hlist);
1168
1169 sk = session->sock;
1170
1171 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1172 "%s: closing session\n", session->name);
1173
1174 hlist_del_init(&session->hlist);
1175
1176 /* Since we should hold the sock lock while
1177 * doing any unbinding, we need to release the
1178 * lock we're holding before taking that lock.
1179 * Hold a reference to the sock so it doesn't
1180 * disappear as we're jumping between locks.
1181 */
1182 sock_hold(sk);
1183 write_unlock_bh(&tunnel->hlist_lock);
1184 lock_sock(sk);
1185
1186 if (sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND)) {
1187 pppox_unbind_sock(sk);
1188 sk->sk_state = PPPOX_DEAD;
1189 sk->sk_state_change(sk);
1190 }
1191
1192 /* Purge any queued data */
1193 skb_queue_purge(&sk->sk_receive_queue);
1194 skb_queue_purge(&sk->sk_write_queue);
1195 while ((skb = skb_dequeue(&session->reorder_q))) {
1196 kfree_skb(skb);
1197 sock_put(sk);
1198 }
1199
1200 release_sock(sk);
1201 sock_put(sk);
1202
1203 /* Now restart from the beginning of this hash
1204 * chain. We always remove a session from the
1205 * list so we are guaranteed to make forward
1206 * progress.
1207 */
1208 write_lock_bh(&tunnel->hlist_lock);
1209 goto again;
1210 }
1211 }
1212 write_unlock_bh(&tunnel->hlist_lock);
1213 }
1214
1215 /* Really kill the tunnel.
1216 * Come here only when all sessions have been cleared from the tunnel.
1217 */
1218 static void pppol2tp_tunnel_free(struct pppol2tp_tunnel *tunnel)
1219 {
1220 /* Remove from socket list */
1221 write_lock_bh(&pppol2tp_tunnel_list_lock);
1222 list_del_init(&tunnel->list);
1223 write_unlock_bh(&pppol2tp_tunnel_list_lock);
1224
1225 atomic_dec(&pppol2tp_tunnel_count);
1226 kfree(tunnel);
1227 }
1228
1229 /* Tunnel UDP socket destruct hook.
1230 * The tunnel context is deleted only when all session sockets have been
1231 * closed.
1232 */
1233 static void pppol2tp_tunnel_destruct(struct sock *sk)
1234 {
1235 struct pppol2tp_tunnel *tunnel;
1236
1237 tunnel = sk->sk_user_data;
1238 if (tunnel == NULL)
1239 goto end;
1240
1241 PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1242 "%s: closing...\n", tunnel->name);
1243
1244 /* Close all sessions */
1245 pppol2tp_tunnel_closeall(tunnel);
1246
1247 /* No longer an encapsulation socket. See net/ipv4/udp.c */
1248 (udp_sk(sk))->encap_type = 0;
1249 (udp_sk(sk))->encap_rcv = NULL;
1250
1251 /* Remove hooks into tunnel socket */
1252 tunnel->sock = NULL;
1253 sk->sk_destruct = tunnel->old_sk_destruct;
1254 sk->sk_user_data = NULL;
1255
1256 /* Call original (UDP) socket descructor */
1257 if (sk->sk_destruct != NULL)
1258 (*sk->sk_destruct)(sk);
1259
1260 pppol2tp_tunnel_dec_refcount(tunnel);
1261
1262 end:
1263 return;
1264 }
1265
1266 /* Really kill the session socket. (Called from sock_put() if
1267 * refcnt == 0.)
1268 */
1269 static void pppol2tp_session_destruct(struct sock *sk)
1270 {
1271 struct pppol2tp_session *session = NULL;
1272
1273 if (sk->sk_user_data != NULL) {
1274 struct pppol2tp_tunnel *tunnel;
1275
1276 session = sk->sk_user_data;
1277 if (session == NULL)
1278 goto out;
1279
1280 BUG_ON(session->magic != L2TP_SESSION_MAGIC);
1281
1282 /* Don't use pppol2tp_sock_to_tunnel() here to
1283 * get the tunnel context because the tunnel
1284 * socket might have already been closed (its
1285 * sk->sk_user_data will be NULL) so use the
1286 * session's private tunnel ptr instead.
1287 */
1288 tunnel = session->tunnel;
1289 if (tunnel != NULL) {
1290 BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);
1291
1292 /* If session_id is zero, this is a null
1293 * session context, which was created for a
1294 * socket that is being used only to manage
1295 * tunnels.
1296 */
1297 if (session->tunnel_addr.s_session != 0) {
1298 /* Delete the session socket from the
1299 * hash
1300 */
1301 write_lock_bh(&tunnel->hlist_lock);
1302 hlist_del_init(&session->hlist);
1303 write_unlock_bh(&tunnel->hlist_lock);
1304
1305 atomic_dec(&pppol2tp_session_count);
1306 }
1307
1308 /* This will delete the tunnel context if this
1309 * is the last session on the tunnel.
1310 */
1311 session->tunnel = NULL;
1312 session->tunnel_sock = NULL;
1313 pppol2tp_tunnel_dec_refcount(tunnel);
1314 }
1315 }
1316
1317 kfree(session);
1318 out:
1319 return;
1320 }
1321
1322 /* Called when the PPPoX socket (session) is closed.
1323 */
1324 static int pppol2tp_release(struct socket *sock)
1325 {
1326 struct sock *sk = sock->sk;
1327 struct pppol2tp_session *session;
1328 int error;
1329
1330 if (!sk)
1331 return 0;
1332
1333 error = -EBADF;
1334 lock_sock(sk);
1335 if (sock_flag(sk, SOCK_DEAD) != 0)
1336 goto error;
1337
1338 pppox_unbind_sock(sk);
1339
1340 /* Signal the death of the socket. */
1341 sk->sk_state = PPPOX_DEAD;
1342 sock_orphan(sk);
1343 sock->sk = NULL;
1344
1345 session = pppol2tp_sock_to_session(sk);
1346
1347 /* Purge any queued data */
1348 skb_queue_purge(&sk->sk_receive_queue);
1349 skb_queue_purge(&sk->sk_write_queue);
1350 if (session != NULL) {
1351 struct sk_buff *skb;
1352 while ((skb = skb_dequeue(&session->reorder_q))) {
1353 kfree_skb(skb);
1354 sock_put(sk);
1355 }
1356 sock_put(sk);
1357 }
1358
1359 release_sock(sk);
1360
1361 /* This will delete the session context via
1362 * pppol2tp_session_destruct() if the socket's refcnt drops to
1363 * zero.
1364 */
1365 sock_put(sk);
1366
1367 return 0;
1368
1369 error:
1370 release_sock(sk);
1371 return error;
1372 }
1373
1374 /* Internal function to prepare a tunnel (UDP) socket to have PPPoX
1375 * sockets attached to it.
1376 */
1377 static struct sock *pppol2tp_prepare_tunnel_socket(int fd, u16 tunnel_id,
1378 int *error)
1379 {
1380 int err;
1381 struct socket *sock = NULL;
1382 struct sock *sk;
1383 struct pppol2tp_tunnel *tunnel;
1384 struct sock *ret = NULL;
1385
1386 /* Get the tunnel UDP socket from the fd, which was opened by
1387 * the userspace L2TP daemon.
1388 */
1389 err = -EBADF;
1390 sock = sockfd_lookup(fd, &err);
1391 if (!sock) {
1392 PRINTK(-1, PPPOL2TP_MSG_CONTROL, KERN_ERR,
1393 "tunl %hu: sockfd_lookup(fd=%d) returned %d\n",
1394 tunnel_id, fd, err);
1395 goto err;
1396 }
1397
1398 sk = sock->sk;
1399
1400 /* Quick sanity checks */
1401 err = -EPROTONOSUPPORT;
1402 if (sk->sk_protocol != IPPROTO_UDP) {
1403 PRINTK(-1, PPPOL2TP_MSG_CONTROL, KERN_ERR,
1404 "tunl %hu: fd %d wrong protocol, got %d, expected %d\n",
1405 tunnel_id, fd, sk->sk_protocol, IPPROTO_UDP);
1406 goto err;
1407 }
1408 err = -EAFNOSUPPORT;
1409 if (sock->ops->family != AF_INET) {
1410 PRINTK(-1, PPPOL2TP_MSG_CONTROL, KERN_ERR,
1411 "tunl %hu: fd %d wrong family, got %d, expected %d\n",
1412 tunnel_id, fd, sock->ops->family, AF_INET);
1413 goto err;
1414 }
1415
1416 err = -ENOTCONN;
1417
1418 /* Check if this socket has already been prepped */
1419 tunnel = (struct pppol2tp_tunnel *)sk->sk_user_data;
1420 if (tunnel != NULL) {
1421 /* User-data field already set */
1422 err = -EBUSY;
1423 BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);
1424
1425 /* This socket has already been prepped */
1426 ret = tunnel->sock;
1427 goto out;
1428 }
1429
1430 /* This socket is available and needs prepping. Create a new tunnel
1431 * context and init it.
1432 */
1433 sk->sk_user_data = tunnel = kzalloc(sizeof(struct pppol2tp_tunnel), GFP_KERNEL);
1434 if (sk->sk_user_data == NULL) {
1435 err = -ENOMEM;
1436 goto err;
1437 }
1438
1439 tunnel->magic = L2TP_TUNNEL_MAGIC;
1440 sprintf(&tunnel->name[0], "tunl %hu", tunnel_id);
1441
1442 tunnel->stats.tunnel_id = tunnel_id;
1443 tunnel->debug = PPPOL2TP_DEFAULT_DEBUG_FLAGS;
1444
1445 /* Hook on the tunnel socket destructor so that we can cleanup
1446 * if the tunnel socket goes away.
1447 */
1448 tunnel->old_sk_destruct = sk->sk_destruct;
1449 sk->sk_destruct = &pppol2tp_tunnel_destruct;
1450
1451 tunnel->sock = sk;
1452 sk->sk_allocation = GFP_ATOMIC;
1453
1454 /* Misc init */
1455 rwlock_init(&tunnel->hlist_lock);
1456
1457 /* Add tunnel to our list */
1458 INIT_LIST_HEAD(&tunnel->list);
1459 write_lock_bh(&pppol2tp_tunnel_list_lock);
1460 list_add(&tunnel->list, &pppol2tp_tunnel_list);
1461 write_unlock_bh(&pppol2tp_tunnel_list_lock);
1462 atomic_inc(&pppol2tp_tunnel_count);
1463
1464 /* Bump the reference count. The tunnel context is deleted
1465 * only when this drops to zero.
1466 */
1467 pppol2tp_tunnel_inc_refcount(tunnel);
1468
1469 /* Mark socket as an encapsulation socket. See net/ipv4/udp.c */
1470 (udp_sk(sk))->encap_type = UDP_ENCAP_L2TPINUDP;
1471 (udp_sk(sk))->encap_rcv = pppol2tp_udp_encap_recv;
1472
1473 ret = tunnel->sock;
1474
1475 *error = 0;
1476 out:
1477 if (sock)
1478 sockfd_put(sock);
1479
1480 return ret;
1481
1482 err:
1483 *error = err;
1484 goto out;
1485 }
1486
1487 static struct proto pppol2tp_sk_proto = {
1488 .name = "PPPOL2TP",
1489 .owner = THIS_MODULE,
1490 .obj_size = sizeof(struct pppox_sock),
1491 };
1492
1493 /* socket() handler. Initialize a new struct sock.
1494 */
1495 static int pppol2tp_create(struct net *net, struct socket *sock)
1496 {
1497 int error = -ENOMEM;
1498 struct sock *sk;
1499
1500 sk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, &pppol2tp_sk_proto);
1501 if (!sk)
1502 goto out;
1503
1504 sock_init_data(sock, sk);
1505
1506 sock->state = SS_UNCONNECTED;
1507 sock->ops = &pppol2tp_ops;
1508
1509 sk->sk_backlog_rcv = pppol2tp_recv_core;
1510 sk->sk_protocol = PX_PROTO_OL2TP;
1511 sk->sk_family = PF_PPPOX;
1512 sk->sk_state = PPPOX_NONE;
1513 sk->sk_type = SOCK_STREAM;
1514 sk->sk_destruct = pppol2tp_session_destruct;
1515
1516 error = 0;
1517
1518 out:
1519 return error;
1520 }
1521
1522 /* connect() handler. Attach a PPPoX socket to a tunnel UDP socket
1523 */
1524 static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr,
1525 int sockaddr_len, int flags)
1526 {
1527 struct sock *sk = sock->sk;
1528 struct sockaddr_pppol2tp *sp = (struct sockaddr_pppol2tp *) uservaddr;
1529 struct pppox_sock *po = pppox_sk(sk);
1530 struct sock *tunnel_sock = NULL;
1531 struct pppol2tp_session *session = NULL;
1532 struct pppol2tp_tunnel *tunnel;
1533 struct dst_entry *dst;
1534 int error = 0;
1535
1536 lock_sock(sk);
1537
1538 error = -EINVAL;
1539 if (sp->sa_protocol != PX_PROTO_OL2TP)
1540 goto end;
1541
1542 /* Check for already bound sockets */
1543 error = -EBUSY;
1544 if (sk->sk_state & PPPOX_CONNECTED)
1545 goto end;
1546
1547 /* We don't supporting rebinding anyway */
1548 error = -EALREADY;
1549 if (sk->sk_user_data)
1550 goto end; /* socket is already attached */
1551
1552 /* Don't bind if s_tunnel is 0 */
1553 error = -EINVAL;
1554 if (sp->pppol2tp.s_tunnel == 0)
1555 goto end;
1556
1557 /* Special case: prepare tunnel socket if s_session and
1558 * d_session is 0. Otherwise look up tunnel using supplied
1559 * tunnel id.
1560 */
1561 if ((sp->pppol2tp.s_session == 0) && (sp->pppol2tp.d_session == 0)) {
1562 tunnel_sock = pppol2tp_prepare_tunnel_socket(sp->pppol2tp.fd,
1563 sp->pppol2tp.s_tunnel,
1564 &error);
1565 if (tunnel_sock == NULL)
1566 goto end;
1567
1568 tunnel = tunnel_sock->sk_user_data;
1569 } else {
1570 tunnel = pppol2tp_tunnel_find(sp->pppol2tp.s_tunnel);
1571
1572 /* Error if we can't find the tunnel */
1573 error = -ENOENT;
1574 if (tunnel == NULL)
1575 goto end;
1576
1577 tunnel_sock = tunnel->sock;
1578 }
1579
1580 /* Check that this session doesn't already exist */
1581 error = -EEXIST;
1582 session = pppol2tp_session_find(tunnel, sp->pppol2tp.s_session);
1583 if (session != NULL)
1584 goto end;
1585
1586 /* Allocate and initialize a new session context. */
1587 session = kzalloc(sizeof(struct pppol2tp_session), GFP_KERNEL);
1588 if (session == NULL) {
1589 error = -ENOMEM;
1590 goto end;
1591 }
1592
1593 skb_queue_head_init(&session->reorder_q);
1594
1595 session->magic = L2TP_SESSION_MAGIC;
1596 session->owner = current->pid;
1597 session->sock = sk;
1598 session->tunnel = tunnel;
1599 session->tunnel_sock = tunnel_sock;
1600 session->tunnel_addr = sp->pppol2tp;
1601 sprintf(&session->name[0], "sess %hu/%hu",
1602 session->tunnel_addr.s_tunnel,
1603 session->tunnel_addr.s_session);
1604
1605 session->stats.tunnel_id = session->tunnel_addr.s_tunnel;
1606 session->stats.session_id = session->tunnel_addr.s_session;
1607
1608 INIT_HLIST_NODE(&session->hlist);
1609
1610 /* Inherit debug options from tunnel */
1611 session->debug = tunnel->debug;
1612
1613 /* Default MTU must allow space for UDP/L2TP/PPP
1614 * headers.
1615 */
1616 session->mtu = session->mru = 1500 - PPPOL2TP_HEADER_OVERHEAD;
1617
1618 /* If PMTU discovery was enabled, use the MTU that was discovered */
1619 dst = sk_dst_get(sk);
1620 if (dst != NULL) {
1621 u32 pmtu = dst_mtu(__sk_dst_get(sk));
1622 if (pmtu != 0)
1623 session->mtu = session->mru = pmtu -
1624 PPPOL2TP_HEADER_OVERHEAD;
1625 dst_release(dst);
1626 }
1627
1628 /* Special case: if source & dest session_id == 0x0000, this socket is
1629 * being created to manage the tunnel. Don't add the session to the
1630 * session hash list, just set up the internal context for use by
1631 * ioctl() and sockopt() handlers.
1632 */
1633 if ((session->tunnel_addr.s_session == 0) &&
1634 (session->tunnel_addr.d_session == 0)) {
1635 error = 0;
1636 sk->sk_user_data = session;
1637 goto out_no_ppp;
1638 }
1639
1640 /* Get tunnel context from the tunnel socket */
1641 tunnel = pppol2tp_sock_to_tunnel(tunnel_sock);
1642 if (tunnel == NULL) {
1643 error = -EBADF;
1644 goto end;
1645 }
1646
1647 /* Right now, because we don't have a way to push the incoming skb's
1648 * straight through the UDP layer, the only header we need to worry
1649 * about is the L2TP header. This size is different depending on
1650 * whether sequence numbers are enabled for the data channel.
1651 */
1652 po->chan.hdrlen = PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
1653
1654 po->chan.private = sk;
1655 po->chan.ops = &pppol2tp_chan_ops;
1656 po->chan.mtu = session->mtu;
1657
1658 error = ppp_register_channel(&po->chan);
1659 if (error)
1660 goto end_put_tun;
1661
1662 /* This is how we get the session context from the socket. */
1663 sk->sk_user_data = session;
1664
1665 /* Add session to the tunnel's hash list */
1666 write_lock_bh(&tunnel->hlist_lock);
1667 hlist_add_head(&session->hlist,
1668 pppol2tp_session_id_hash(tunnel,
1669 session->tunnel_addr.s_session));
1670 write_unlock_bh(&tunnel->hlist_lock);
1671
1672 atomic_inc(&pppol2tp_session_count);
1673
1674 out_no_ppp:
1675 pppol2tp_tunnel_inc_refcount(tunnel);
1676 sk->sk_state = PPPOX_CONNECTED;
1677 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1678 "%s: created\n", session->name);
1679
1680 end_put_tun:
1681 sock_put(tunnel_sock);
1682 end:
1683 release_sock(sk);
1684
1685 if (error != 0) {
1686 if (session)
1687 PRINTK(session->debug,
1688 PPPOL2TP_MSG_CONTROL, KERN_WARNING,
1689 "%s: connect failed: %d\n",
1690 session->name, error);
1691 else
1692 PRINTK(-1, PPPOL2TP_MSG_CONTROL, KERN_WARNING,
1693 "connect failed: %d\n", error);
1694 }
1695
1696 return error;
1697 }
1698
1699 /* getname() support.
1700 */
1701 static int pppol2tp_getname(struct socket *sock, struct sockaddr *uaddr,
1702 int *usockaddr_len, int peer)
1703 {
1704 int len = sizeof(struct sockaddr_pppol2tp);
1705 struct sockaddr_pppol2tp sp;
1706 int error = 0;
1707 struct pppol2tp_session *session;
1708
1709 error = -ENOTCONN;
1710 if (sock->sk->sk_state != PPPOX_CONNECTED)
1711 goto end;
1712
1713 session = pppol2tp_sock_to_session(sock->sk);
1714 if (session == NULL) {
1715 error = -EBADF;
1716 goto end;
1717 }
1718
1719 sp.sa_family = AF_PPPOX;
1720 sp.sa_protocol = PX_PROTO_OL2TP;
1721 memcpy(&sp.pppol2tp, &session->tunnel_addr,
1722 sizeof(struct pppol2tp_addr));
1723
1724 memcpy(uaddr, &sp, len);
1725
1726 *usockaddr_len = len;
1727
1728 error = 0;
1729 sock_put(sock->sk);
1730
1731 end:
1732 return error;
1733 }
1734
1735 /****************************************************************************
1736 * ioctl() handlers.
1737 *
1738 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
1739 * sockets. However, in order to control kernel tunnel features, we allow
1740 * userspace to create a special "tunnel" PPPoX socket which is used for
1741 * control only. Tunnel PPPoX sockets have session_id == 0 and simply allow
1742 * the user application to issue L2TP setsockopt(), getsockopt() and ioctl()
1743 * calls.
1744 ****************************************************************************/
1745
1746 /* Session ioctl helper.
1747 */
1748 static int pppol2tp_session_ioctl(struct pppol2tp_session *session,
1749 unsigned int cmd, unsigned long arg)
1750 {
1751 struct ifreq ifr;
1752 int err = 0;
1753 struct sock *sk = session->sock;
1754 int val = (int) arg;
1755
1756 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_DEBUG,
1757 "%s: pppol2tp_session_ioctl(cmd=%#x, arg=%#lx)\n",
1758 session->name, cmd, arg);
1759
1760 sock_hold(sk);
1761
1762 switch (cmd) {
1763 case SIOCGIFMTU:
1764 err = -ENXIO;
1765 if (!(sk->sk_state & PPPOX_CONNECTED))
1766 break;
1767
1768 err = -EFAULT;
1769 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq)))
1770 break;
1771 ifr.ifr_mtu = session->mtu;
1772 if (copy_to_user((void __user *) arg, &ifr, sizeof(struct ifreq)))
1773 break;
1774
1775 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1776 "%s: get mtu=%d\n", session->name, session->mtu);
1777 err = 0;
1778 break;
1779
1780 case SIOCSIFMTU:
1781 err = -ENXIO;
1782 if (!(sk->sk_state & PPPOX_CONNECTED))
1783 break;
1784
1785 err = -EFAULT;
1786 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq)))
1787 break;
1788
1789 session->mtu = ifr.ifr_mtu;
1790
1791 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1792 "%s: set mtu=%d\n", session->name, session->mtu);
1793 err = 0;
1794 break;
1795
1796 case PPPIOCGMRU:
1797 err = -ENXIO;
1798 if (!(sk->sk_state & PPPOX_CONNECTED))
1799 break;
1800
1801 err = -EFAULT;
1802 if (put_user(session->mru, (int __user *) arg))
1803 break;
1804
1805 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1806 "%s: get mru=%d\n", session->name, session->mru);
1807 err = 0;
1808 break;
1809
1810 case PPPIOCSMRU:
1811 err = -ENXIO;
1812 if (!(sk->sk_state & PPPOX_CONNECTED))
1813 break;
1814
1815 err = -EFAULT;
1816 if (get_user(val,(int __user *) arg))
1817 break;
1818
1819 session->mru = val;
1820 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1821 "%s: set mru=%d\n", session->name, session->mru);
1822 err = 0;
1823 break;
1824
1825 case PPPIOCGFLAGS:
1826 err = -EFAULT;
1827 if (put_user(session->flags, (int __user *) arg))
1828 break;
1829
1830 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1831 "%s: get flags=%d\n", session->name, session->flags);
1832 err = 0;
1833 break;
1834
1835 case PPPIOCSFLAGS:
1836 err = -EFAULT;
1837 if (get_user(val, (int __user *) arg))
1838 break;
1839 session->flags = val;
1840 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1841 "%s: set flags=%d\n", session->name, session->flags);
1842 err = 0;
1843 break;
1844
1845 case PPPIOCGL2TPSTATS:
1846 err = -ENXIO;
1847 if (!(sk->sk_state & PPPOX_CONNECTED))
1848 break;
1849
1850 if (copy_to_user((void __user *) arg, &session->stats,
1851 sizeof(session->stats)))
1852 break;
1853 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1854 "%s: get L2TP stats\n", session->name);
1855 err = 0;
1856 break;
1857
1858 default:
1859 err = -ENOSYS;
1860 break;
1861 }
1862
1863 sock_put(sk);
1864
1865 return err;
1866 }
1867
1868 /* Tunnel ioctl helper.
1869 *
1870 * Note the special handling for PPPIOCGL2TPSTATS below. If the ioctl data
1871 * specifies a session_id, the session ioctl handler is called. This allows an
1872 * application to retrieve session stats via a tunnel socket.
1873 */
1874 static int pppol2tp_tunnel_ioctl(struct pppol2tp_tunnel *tunnel,
1875 unsigned int cmd, unsigned long arg)
1876 {
1877 int err = 0;
1878 struct sock *sk = tunnel->sock;
1879 struct pppol2tp_ioc_stats stats_req;
1880
1881 PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_DEBUG,
1882 "%s: pppol2tp_tunnel_ioctl(cmd=%#x, arg=%#lx)\n", tunnel->name,
1883 cmd, arg);
1884
1885 sock_hold(sk);
1886
1887 switch (cmd) {
1888 case PPPIOCGL2TPSTATS:
1889 err = -ENXIO;
1890 if (!(sk->sk_state & PPPOX_CONNECTED))
1891 break;
1892
1893 if (copy_from_user(&stats_req, (void __user *) arg,
1894 sizeof(stats_req))) {
1895 err = -EFAULT;
1896 break;
1897 }
1898 if (stats_req.session_id != 0) {
1899 /* resend to session ioctl handler */
1900 struct pppol2tp_session *session =
1901 pppol2tp_session_find(tunnel, stats_req.session_id);
1902 if (session != NULL)
1903 err = pppol2tp_session_ioctl(session, cmd, arg);
1904 else
1905 err = -EBADR;
1906 break;
1907 }
1908 #ifdef CONFIG_XFRM
1909 tunnel->stats.using_ipsec = (sk->sk_policy[0] || sk->sk_policy[1]) ? 1 : 0;
1910 #endif
1911 if (copy_to_user((void __user *) arg, &tunnel->stats,
1912 sizeof(tunnel->stats))) {
1913 err = -EFAULT;
1914 break;
1915 }
1916 PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1917 "%s: get L2TP stats\n", tunnel->name);
1918 err = 0;
1919 break;
1920
1921 default:
1922 err = -ENOSYS;
1923 break;
1924 }
1925
1926 sock_put(sk);
1927
1928 return err;
1929 }
1930
1931 /* Main ioctl() handler.
1932 * Dispatch to tunnel or session helpers depending on the socket.
1933 */
1934 static int pppol2tp_ioctl(struct socket *sock, unsigned int cmd,
1935 unsigned long arg)
1936 {
1937 struct sock *sk = sock->sk;
1938 struct pppol2tp_session *session;
1939 struct pppol2tp_tunnel *tunnel;
1940 int err;
1941
1942 if (!sk)
1943 return 0;
1944
1945 err = -EBADF;
1946 if (sock_flag(sk, SOCK_DEAD) != 0)
1947 goto end;
1948
1949 err = -ENOTCONN;
1950 if ((sk->sk_user_data == NULL) ||
1951 (!(sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND))))
1952 goto end;
1953
1954 /* Get session context from the socket */
1955 err = -EBADF;
1956 session = pppol2tp_sock_to_session(sk);
1957 if (session == NULL)
1958 goto end;
1959
1960 /* Special case: if session's session_id is zero, treat ioctl as a
1961 * tunnel ioctl
1962 */
1963 if ((session->tunnel_addr.s_session == 0) &&
1964 (session->tunnel_addr.d_session == 0)) {
1965 err = -EBADF;
1966 tunnel = pppol2tp_sock_to_tunnel(session->tunnel_sock);
1967 if (tunnel == NULL)
1968 goto end_put_sess;
1969
1970 err = pppol2tp_tunnel_ioctl(tunnel, cmd, arg);
1971 sock_put(session->tunnel_sock);
1972 goto end_put_sess;
1973 }
1974
1975 err = pppol2tp_session_ioctl(session, cmd, arg);
1976
1977 end_put_sess:
1978 sock_put(sk);
1979 end:
1980 return err;
1981 }
1982
1983 /*****************************************************************************
1984 * setsockopt() / getsockopt() support.
1985 *
1986 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
1987 * sockets. In order to control kernel tunnel features, we allow userspace to
1988 * create a special "tunnel" PPPoX socket which is used for control only.
1989 * Tunnel PPPoX sockets have session_id == 0 and simply allow the user
1990 * application to issue L2TP setsockopt(), getsockopt() and ioctl() calls.
1991 *****************************************************************************/
1992
1993 /* Tunnel setsockopt() helper.
1994 */
1995 static int pppol2tp_tunnel_setsockopt(struct sock *sk,
1996 struct pppol2tp_tunnel *tunnel,
1997 int optname, int val)
1998 {
1999 int err = 0;
2000
2001 switch (optname) {
2002 case PPPOL2TP_SO_DEBUG:
2003 tunnel->debug = val;
2004 PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2005 "%s: set debug=%x\n", tunnel->name, tunnel->debug);
2006 break;
2007
2008 default:
2009 err = -ENOPROTOOPT;
2010 break;
2011 }
2012
2013 return err;
2014 }
2015
2016 /* Session setsockopt helper.
2017 */
2018 static int pppol2tp_session_setsockopt(struct sock *sk,
2019 struct pppol2tp_session *session,
2020 int optname, int val)
2021 {
2022 int err = 0;
2023
2024 switch (optname) {
2025 case PPPOL2TP_SO_RECVSEQ:
2026 if ((val != 0) && (val != 1)) {
2027 err = -EINVAL;
2028 break;
2029 }
2030 session->recv_seq = val ? -1 : 0;
2031 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2032 "%s: set recv_seq=%d\n", session->name,
2033 session->recv_seq);
2034 break;
2035
2036 case PPPOL2TP_SO_SENDSEQ:
2037 if ((val != 0) && (val != 1)) {
2038 err = -EINVAL;
2039 break;
2040 }
2041 session->send_seq = val ? -1 : 0;
2042 {
2043 struct sock *ssk = session->sock;
2044 struct pppox_sock *po = pppox_sk(ssk);
2045 po->chan.hdrlen = val ? PPPOL2TP_L2TP_HDR_SIZE_SEQ :
2046 PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
2047 }
2048 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2049 "%s: set send_seq=%d\n", session->name, session->send_seq);
2050 break;
2051
2052 case PPPOL2TP_SO_LNSMODE:
2053 if ((val != 0) && (val != 1)) {
2054 err = -EINVAL;
2055 break;
2056 }
2057 session->lns_mode = val ? -1 : 0;
2058 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2059 "%s: set lns_mode=%d\n", session->name,
2060 session->lns_mode);
2061 break;
2062
2063 case PPPOL2TP_SO_DEBUG:
2064 session->debug = val;
2065 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2066 "%s: set debug=%x\n", session->name, session->debug);
2067 break;
2068
2069 case PPPOL2TP_SO_REORDERTO:
2070 session->reorder_timeout = msecs_to_jiffies(val);
2071 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2072 "%s: set reorder_timeout=%d\n", session->name,
2073 session->reorder_timeout);
2074 break;
2075
2076 default:
2077 err = -ENOPROTOOPT;
2078 break;
2079 }
2080
2081 return err;
2082 }
2083
2084 /* Main setsockopt() entry point.
2085 * Does API checks, then calls either the tunnel or session setsockopt
2086 * handler, according to whether the PPPoL2TP socket is a for a regular
2087 * session or the special tunnel type.
2088 */
2089 static int pppol2tp_setsockopt(struct socket *sock, int level, int optname,
2090 char __user *optval, int optlen)
2091 {
2092 struct sock *sk = sock->sk;
2093 struct pppol2tp_session *session = sk->sk_user_data;
2094 struct pppol2tp_tunnel *tunnel;
2095 int val;
2096 int err;
2097
2098 if (level != SOL_PPPOL2TP)
2099 return udp_prot.setsockopt(sk, level, optname, optval, optlen);
2100
2101 if (optlen < sizeof(int))
2102 return -EINVAL;
2103
2104 if (get_user(val, (int __user *)optval))
2105 return -EFAULT;
2106
2107 err = -ENOTCONN;
2108 if (sk->sk_user_data == NULL)
2109 goto end;
2110
2111 /* Get session context from the socket */
2112 err = -EBADF;
2113 session = pppol2tp_sock_to_session(sk);
2114 if (session == NULL)
2115 goto end;
2116
2117 /* Special case: if session_id == 0x0000, treat as operation on tunnel
2118 */
2119 if ((session->tunnel_addr.s_session == 0) &&
2120 (session->tunnel_addr.d_session == 0)) {
2121 err = -EBADF;
2122 tunnel = pppol2tp_sock_to_tunnel(session->tunnel_sock);
2123 if (tunnel == NULL)
2124 goto end_put_sess;
2125
2126 err = pppol2tp_tunnel_setsockopt(sk, tunnel, optname, val);
2127 sock_put(session->tunnel_sock);
2128 } else
2129 err = pppol2tp_session_setsockopt(sk, session, optname, val);
2130
2131 err = 0;
2132
2133 end_put_sess:
2134 sock_put(sk);
2135 end:
2136 return err;
2137 }
2138
2139 /* Tunnel getsockopt helper. Called with sock locked.
2140 */
2141 static int pppol2tp_tunnel_getsockopt(struct sock *sk,
2142 struct pppol2tp_tunnel *tunnel,
2143 int optname, int *val)
2144 {
2145 int err = 0;
2146
2147 switch (optname) {
2148 case PPPOL2TP_SO_DEBUG:
2149 *val = tunnel->debug;
2150 PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2151 "%s: get debug=%x\n", tunnel->name, tunnel->debug);
2152 break;
2153
2154 default:
2155 err = -ENOPROTOOPT;
2156 break;
2157 }
2158
2159 return err;
2160 }
2161
2162 /* Session getsockopt helper. Called with sock locked.
2163 */
2164 static int pppol2tp_session_getsockopt(struct sock *sk,
2165 struct pppol2tp_session *session,
2166 int optname, int *val)
2167 {
2168 int err = 0;
2169
2170 switch (optname) {
2171 case PPPOL2TP_SO_RECVSEQ:
2172 *val = session->recv_seq;
2173 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2174 "%s: get recv_seq=%d\n", session->name, *val);
2175 break;
2176
2177 case PPPOL2TP_SO_SENDSEQ:
2178 *val = session->send_seq;
2179 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2180 "%s: get send_seq=%d\n", session->name, *val);
2181 break;
2182
2183 case PPPOL2TP_SO_LNSMODE:
2184 *val = session->lns_mode;
2185 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2186 "%s: get lns_mode=%d\n", session->name, *val);
2187 break;
2188
2189 case PPPOL2TP_SO_DEBUG:
2190 *val = session->debug;
2191 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2192 "%s: get debug=%d\n", session->name, *val);
2193 break;
2194
2195 case PPPOL2TP_SO_REORDERTO:
2196 *val = (int) jiffies_to_msecs(session->reorder_timeout);
2197 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2198 "%s: get reorder_timeout=%d\n", session->name, *val);
2199 break;
2200
2201 default:
2202 err = -ENOPROTOOPT;
2203 }
2204
2205 return err;
2206 }
2207
2208 /* Main getsockopt() entry point.
2209 * Does API checks, then calls either the tunnel or session getsockopt
2210 * handler, according to whether the PPPoX socket is a for a regular session
2211 * or the special tunnel type.
2212 */
2213 static int pppol2tp_getsockopt(struct socket *sock, int level,
2214 int optname, char __user *optval, int __user *optlen)
2215 {
2216 struct sock *sk = sock->sk;
2217 struct pppol2tp_session *session = sk->sk_user_data;
2218 struct pppol2tp_tunnel *tunnel;
2219 int val, len;
2220 int err;
2221
2222 if (level != SOL_PPPOL2TP)
2223 return udp_prot.getsockopt(sk, level, optname, optval, optlen);
2224
2225 if (get_user(len, (int __user *) optlen))
2226 return -EFAULT;
2227
2228 len = min_t(unsigned int, len, sizeof(int));
2229
2230 if (len < 0)
2231 return -EINVAL;
2232
2233 err = -ENOTCONN;
2234 if (sk->sk_user_data == NULL)
2235 goto end;
2236
2237 /* Get the session context */
2238 err = -EBADF;
2239 session = pppol2tp_sock_to_session(sk);
2240 if (session == NULL)
2241 goto end;
2242
2243 /* Special case: if session_id == 0x0000, treat as operation on tunnel */
2244 if ((session->tunnel_addr.s_session == 0) &&
2245 (session->tunnel_addr.d_session == 0)) {
2246 err = -EBADF;
2247 tunnel = pppol2tp_sock_to_tunnel(session->tunnel_sock);
2248 if (tunnel == NULL)
2249 goto end_put_sess;
2250
2251 err = pppol2tp_tunnel_getsockopt(sk, tunnel, optname, &val);
2252 sock_put(session->tunnel_sock);
2253 } else
2254 err = pppol2tp_session_getsockopt(sk, session, optname, &val);
2255
2256 err = -EFAULT;
2257 if (put_user(len, (int __user *) optlen))
2258 goto end_put_sess;
2259
2260 if (copy_to_user((void __user *) optval, &val, len))
2261 goto end_put_sess;
2262
2263 err = 0;
2264
2265 end_put_sess:
2266 sock_put(sk);
2267 end:
2268 return err;
2269 }
2270
2271 /*****************************************************************************
2272 * /proc filesystem for debug
2273 *****************************************************************************/
2274
2275 #ifdef CONFIG_PROC_FS
2276
2277 #include <linux/seq_file.h>
2278
2279 struct pppol2tp_seq_data {
2280 struct pppol2tp_tunnel *tunnel; /* current tunnel */
2281 struct pppol2tp_session *session; /* NULL means get first session in tunnel */
2282 };
2283
2284 static struct pppol2tp_session *next_session(struct pppol2tp_tunnel *tunnel, struct pppol2tp_session *curr)
2285 {
2286 struct pppol2tp_session *session = NULL;
2287 struct hlist_node *walk;
2288 int found = 0;
2289 int next = 0;
2290 int i;
2291
2292 read_lock_bh(&tunnel->hlist_lock);
2293 for (i = 0; i < PPPOL2TP_HASH_SIZE; i++) {
2294 hlist_for_each_entry(session, walk, &tunnel->session_hlist[i], hlist) {
2295 if (curr == NULL) {
2296 found = 1;
2297 goto out;
2298 }
2299 if (session == curr) {
2300 next = 1;
2301 continue;
2302 }
2303 if (next) {
2304 found = 1;
2305 goto out;
2306 }
2307 }
2308 }
2309 out:
2310 read_unlock_bh(&tunnel->hlist_lock);
2311 if (!found)
2312 session = NULL;
2313
2314 return session;
2315 }
2316
2317 static struct pppol2tp_tunnel *next_tunnel(struct pppol2tp_tunnel *curr)
2318 {
2319 struct pppol2tp_tunnel *tunnel = NULL;
2320
2321 read_lock_bh(&pppol2tp_tunnel_list_lock);
2322 if (list_is_last(&curr->list, &pppol2tp_tunnel_list)) {
2323 goto out;
2324 }
2325 tunnel = list_entry(curr->list.next, struct pppol2tp_tunnel, list);
2326 out:
2327 read_unlock_bh(&pppol2tp_tunnel_list_lock);
2328
2329 return tunnel;
2330 }
2331
2332 static void *pppol2tp_seq_start(struct seq_file *m, loff_t *offs)
2333 {
2334 struct pppol2tp_seq_data *pd = SEQ_START_TOKEN;
2335 loff_t pos = *offs;
2336
2337 if (!pos)
2338 goto out;
2339
2340 BUG_ON(m->private == NULL);
2341 pd = m->private;
2342
2343 if (pd->tunnel == NULL) {
2344 if (!list_empty(&pppol2tp_tunnel_list))
2345 pd->tunnel = list_entry(pppol2tp_tunnel_list.next, struct pppol2tp_tunnel, list);
2346 } else {
2347 pd->session = next_session(pd->tunnel, pd->session);
2348 if (pd->session == NULL) {
2349 pd->tunnel = next_tunnel(pd->tunnel);
2350 }
2351 }
2352
2353 /* NULL tunnel and session indicates end of list */
2354 if ((pd->tunnel == NULL) && (pd->session == NULL))
2355 pd = NULL;
2356
2357 out:
2358 return pd;
2359 }
2360
2361 static void *pppol2tp_seq_next(struct seq_file *m, void *v, loff_t *pos)
2362 {
2363 (*pos)++;
2364 return NULL;
2365 }
2366
2367 static void pppol2tp_seq_stop(struct seq_file *p, void *v)
2368 {
2369 /* nothing to do */
2370 }
2371
2372 static void pppol2tp_seq_tunnel_show(struct seq_file *m, void *v)
2373 {
2374 struct pppol2tp_tunnel *tunnel = v;
2375
2376 seq_printf(m, "\nTUNNEL '%s', %c %d\n",
2377 tunnel->name,
2378 (tunnel == tunnel->sock->sk_user_data) ? 'Y':'N',
2379 atomic_read(&tunnel->ref_count) - 1);
2380 seq_printf(m, " %08x %llu/%llu/%llu %llu/%llu/%llu\n",
2381 tunnel->debug,
2382 (unsigned long long)tunnel->stats.tx_packets,
2383 (unsigned long long)tunnel->stats.tx_bytes,
2384 (unsigned long long)tunnel->stats.tx_errors,
2385 (unsigned long long)tunnel->stats.rx_packets,
2386 (unsigned long long)tunnel->stats.rx_bytes,
2387 (unsigned long long)tunnel->stats.rx_errors);
2388 }
2389
2390 static void pppol2tp_seq_session_show(struct seq_file *m, void *v)
2391 {
2392 struct pppol2tp_session *session = v;
2393
2394 seq_printf(m, " SESSION '%s' %08X/%d %04X/%04X -> "
2395 "%04X/%04X %d %c\n",
2396 session->name,
2397 ntohl(session->tunnel_addr.addr.sin_addr.s_addr),
2398 ntohs(session->tunnel_addr.addr.sin_port),
2399 session->tunnel_addr.s_tunnel,
2400 session->tunnel_addr.s_session,
2401 session->tunnel_addr.d_tunnel,
2402 session->tunnel_addr.d_session,
2403 session->sock->sk_state,
2404 (session == session->sock->sk_user_data) ?
2405 'Y' : 'N');
2406 seq_printf(m, " %d/%d/%c/%c/%s %08x %u\n",
2407 session->mtu, session->mru,
2408 session->recv_seq ? 'R' : '-',
2409 session->send_seq ? 'S' : '-',
2410 session->lns_mode ? "LNS" : "LAC",
2411 session->debug,
2412 jiffies_to_msecs(session->reorder_timeout));
2413 seq_printf(m, " %hu/%hu %llu/%llu/%llu %llu/%llu/%llu\n",
2414 session->nr, session->ns,
2415 (unsigned long long)session->stats.tx_packets,
2416 (unsigned long long)session->stats.tx_bytes,
2417 (unsigned long long)session->stats.tx_errors,
2418 (unsigned long long)session->stats.rx_packets,
2419 (unsigned long long)session->stats.rx_bytes,
2420 (unsigned long long)session->stats.rx_errors);
2421 }
2422
2423 static int pppol2tp_seq_show(struct seq_file *m, void *v)
2424 {
2425 struct pppol2tp_seq_data *pd = v;
2426
2427 /* display header on line 1 */
2428 if (v == SEQ_START_TOKEN) {
2429 seq_puts(m, "PPPoL2TP driver info, " PPPOL2TP_DRV_VERSION "\n");
2430 seq_puts(m, "TUNNEL name, user-data-ok session-count\n");
2431 seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
2432 seq_puts(m, " SESSION name, addr/port src-tid/sid "
2433 "dest-tid/sid state user-data-ok\n");
2434 seq_puts(m, " mtu/mru/rcvseq/sendseq/lns debug reorderto\n");
2435 seq_puts(m, " nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
2436 goto out;
2437 }
2438
2439 /* Show the tunnel or session context.
2440 */
2441 if (pd->session == NULL)
2442 pppol2tp_seq_tunnel_show(m, pd->tunnel);
2443 else
2444 pppol2tp_seq_session_show(m, pd->session);
2445
2446 out:
2447 return 0;
2448 }
2449
2450 static struct seq_operations pppol2tp_seq_ops = {
2451 .start = pppol2tp_seq_start,
2452 .next = pppol2tp_seq_next,
2453 .stop = pppol2tp_seq_stop,
2454 .show = pppol2tp_seq_show,
2455 };
2456
2457 /* Called when our /proc file is opened. We allocate data for use when
2458 * iterating our tunnel / session contexts and store it in the private
2459 * data of the seq_file.
2460 */
2461 static int pppol2tp_proc_open(struct inode *inode, struct file *file)
2462 {
2463 struct seq_file *m;
2464 struct pppol2tp_seq_data *pd;
2465 int ret = 0;
2466
2467 ret = seq_open(file, &pppol2tp_seq_ops);
2468 if (ret < 0)
2469 goto out;
2470
2471 m = file->private_data;
2472
2473 /* Allocate and fill our proc_data for access later */
2474 ret = -ENOMEM;
2475 m->private = kzalloc(sizeof(struct pppol2tp_seq_data), GFP_KERNEL);
2476 if (m->private == NULL)
2477 goto out;
2478
2479 pd = m->private;
2480 ret = 0;
2481
2482 out:
2483 return ret;
2484 }
2485
2486 /* Called when /proc file access completes.
2487 */
2488 static int pppol2tp_proc_release(struct inode *inode, struct file *file)
2489 {
2490 struct seq_file *m = (struct seq_file *)file->private_data;
2491
2492 kfree(m->private);
2493 m->private = NULL;
2494
2495 return seq_release(inode, file);
2496 }
2497
2498 static struct file_operations pppol2tp_proc_fops = {
2499 .owner = THIS_MODULE,
2500 .open = pppol2tp_proc_open,
2501 .read = seq_read,
2502 .llseek = seq_lseek,
2503 .release = pppol2tp_proc_release,
2504 };
2505
2506 static struct proc_dir_entry *pppol2tp_proc;
2507
2508 #endif /* CONFIG_PROC_FS */
2509
2510 /*****************************************************************************
2511 * Init and cleanup
2512 *****************************************************************************/
2513
2514 static struct proto_ops pppol2tp_ops = {
2515 .family = AF_PPPOX,
2516 .owner = THIS_MODULE,
2517 .release = pppol2tp_release,
2518 .bind = sock_no_bind,
2519 .connect = pppol2tp_connect,
2520 .socketpair = sock_no_socketpair,
2521 .accept = sock_no_accept,
2522 .getname = pppol2tp_getname,
2523 .poll = datagram_poll,
2524 .listen = sock_no_listen,
2525 .shutdown = sock_no_shutdown,
2526 .setsockopt = pppol2tp_setsockopt,
2527 .getsockopt = pppol2tp_getsockopt,
2528 .sendmsg = pppol2tp_sendmsg,
2529 .recvmsg = pppol2tp_recvmsg,
2530 .mmap = sock_no_mmap,
2531 .ioctl = pppox_ioctl,
2532 };
2533
2534 static struct pppox_proto pppol2tp_proto = {
2535 .create = pppol2tp_create,
2536 .ioctl = pppol2tp_ioctl
2537 };
2538
2539 static int __init pppol2tp_init(void)
2540 {
2541 int err;
2542
2543 err = proto_register(&pppol2tp_sk_proto, 0);
2544 if (err)
2545 goto out;
2546 err = register_pppox_proto(PX_PROTO_OL2TP, &pppol2tp_proto);
2547 if (err)
2548 goto out_unregister_pppol2tp_proto;
2549
2550 #ifdef CONFIG_PROC_FS
2551 pppol2tp_proc = proc_net_fops_create(&init_net, "pppol2tp", 0,
2552 &pppol2tp_proc_fops);
2553 if (!pppol2tp_proc) {
2554 err = -ENOMEM;
2555 goto out_unregister_pppox_proto;
2556 }
2557 #endif /* CONFIG_PROC_FS */
2558 printk(KERN_INFO "PPPoL2TP kernel driver, %s\n",
2559 PPPOL2TP_DRV_VERSION);
2560
2561 out:
2562 return err;
2563 #ifdef CONFIG_PROC_FS
2564 out_unregister_pppox_proto:
2565 unregister_pppox_proto(PX_PROTO_OL2TP);
2566 #endif
2567 out_unregister_pppol2tp_proto:
2568 proto_unregister(&pppol2tp_sk_proto);
2569 goto out;
2570 }
2571
2572 static void __exit pppol2tp_exit(void)
2573 {
2574 unregister_pppox_proto(PX_PROTO_OL2TP);
2575
2576 #ifdef CONFIG_PROC_FS
2577 remove_proc_entry("pppol2tp", init_net.proc_net);
2578 #endif
2579 proto_unregister(&pppol2tp_sk_proto);
2580 }
2581
2582 module_init(pppol2tp_init);
2583 module_exit(pppol2tp_exit);
2584
2585 MODULE_AUTHOR("Martijn van Oosterhout <kleptog@svana.org>, "
2586 "James Chapman <jchapman@katalix.com>");
2587 MODULE_DESCRIPTION("PPP over L2TP over UDP");
2588 MODULE_LICENSE("GPL");
2589 MODULE_VERSION(PPPOL2TP_DRV_VERSION);
Stable & featurefull patchset based on Linus's git branch