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