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Diffstat (limited to 'drivers/net/pppol2tp.c')
-rw-r--r--drivers/net/pppol2tp.c2486
1 files changed, 2486 insertions, 0 deletions
diff --git a/drivers/net/pppol2tp.c b/drivers/net/pppol2tp.c
new file mode 100644
index 000000000000..8a6bff5c3849
--- /dev/null
+++ b/drivers/net/pppol2tp.c
@@ -0,0 +1,2486 @@
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/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
141struct 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 */
147struct 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 */
190struct 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 */
213struct 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
223static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb);
224static void pppol2tp_tunnel_free(struct pppol2tp_tunnel *tunnel);
225
226static atomic_t pppol2tp_tunnel_count;
227static atomic_t pppol2tp_session_count;
228static struct ppp_channel_ops pppol2tp_chan_ops = { pppol2tp_xmit , NULL };
229static struct proto_ops pppol2tp_ops;
230static LIST_HEAD(pppol2tp_tunnel_list);
231static DEFINE_RWLOCK(pppol2tp_tunnel_list_lock);
232
233/* Helpers to obtain tunnel/session contexts from sockets.
234 */
235static 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 session = (struct pppol2tp_session *)(sk->sk_user_data);
243 if (session == NULL)
244 return NULL;
245
246 BUG_ON(session->magic != L2TP_SESSION_MAGIC);
247
248 return session;
249}
250
251static inline struct pppol2tp_tunnel *pppol2tp_sock_to_tunnel(struct sock *sk)
252{
253 struct pppol2tp_tunnel *tunnel;
254
255 if (sk == NULL)
256 return NULL;
257
258 tunnel = (struct pppol2tp_tunnel *)(sk->sk_user_data);
259 if (tunnel == NULL)
260 return NULL;
261
262 BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);
263
264 return tunnel;
265}
266
267/* Tunnel reference counts. Incremented per session that is added to
268 * the tunnel.
269 */
270static inline void pppol2tp_tunnel_inc_refcount(struct pppol2tp_tunnel *tunnel)
271{
272 atomic_inc(&tunnel->ref_count);
273}
274
275static inline void pppol2tp_tunnel_dec_refcount(struct pppol2tp_tunnel *tunnel)
276{
277 if (atomic_dec_and_test(&tunnel->ref_count))
278 pppol2tp_tunnel_free(tunnel);
279}
280
281/* Session hash list.
282 * The session_id SHOULD be random according to RFC2661, but several
283 * L2TP implementations (Cisco and Microsoft) use incrementing
284 * session_ids. So we do a real hash on the session_id, rather than a
285 * simple bitmask.
286 */
287static inline struct hlist_head *
288pppol2tp_session_id_hash(struct pppol2tp_tunnel *tunnel, u16 session_id)
289{
290 unsigned long hash_val = (unsigned long) session_id;
291 return &tunnel->session_hlist[hash_long(hash_val, PPPOL2TP_HASH_BITS)];
292}
293
294/* Lookup a session by id
295 */
296static struct pppol2tp_session *
297pppol2tp_session_find(struct pppol2tp_tunnel *tunnel, u16 session_id)
298{
299 struct hlist_head *session_list =
300 pppol2tp_session_id_hash(tunnel, session_id);
301 struct pppol2tp_session *session;
302 struct hlist_node *walk;
303
304 read_lock(&tunnel->hlist_lock);
305 hlist_for_each_entry(session, walk, session_list, hlist) {
306 if (session->tunnel_addr.s_session == session_id) {
307 read_unlock(&tunnel->hlist_lock);
308 return session;
309 }
310 }
311 read_unlock(&tunnel->hlist_lock);
312
313 return NULL;
314}
315
316/* Lookup a tunnel by id
317 */
318static struct pppol2tp_tunnel *pppol2tp_tunnel_find(u16 tunnel_id)
319{
320 struct pppol2tp_tunnel *tunnel = NULL;
321
322 read_lock(&pppol2tp_tunnel_list_lock);
323 list_for_each_entry(tunnel, &pppol2tp_tunnel_list, list) {
324 if (tunnel->stats.tunnel_id == tunnel_id) {
325 read_unlock(&pppol2tp_tunnel_list_lock);
326 return tunnel;
327 }
328 }
329 read_unlock(&pppol2tp_tunnel_list_lock);
330
331 return NULL;
332}
333
334/*****************************************************************************
335 * Receive data handling
336 *****************************************************************************/
337
338/* Queue a skb in order. We come here only if the skb has an L2TP sequence
339 * number.
340 */
341static void pppol2tp_recv_queue_skb(struct pppol2tp_session *session, struct sk_buff *skb)
342{
343 struct sk_buff *skbp;
344 u16 ns = PPPOL2TP_SKB_CB(skb)->ns;
345
346 spin_lock(&session->reorder_q.lock);
347 skb_queue_walk(&session->reorder_q, skbp) {
348 if (PPPOL2TP_SKB_CB(skbp)->ns > ns) {
349 __skb_insert(skb, skbp->prev, skbp, &session->reorder_q);
350 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
351 "%s: pkt %hu, inserted before %hu, reorder_q len=%d\n",
352 session->name, ns, PPPOL2TP_SKB_CB(skbp)->ns,
353 skb_queue_len(&session->reorder_q));
354 session->stats.rx_oos_packets++;
355 goto out;
356 }
357 }
358
359 __skb_queue_tail(&session->reorder_q, skb);
360
361out:
362 spin_unlock(&session->reorder_q.lock);
363}
364
365/* Dequeue a single skb.
366 */
367static void pppol2tp_recv_dequeue_skb(struct pppol2tp_session *session, struct sk_buff *skb)
368{
369 struct pppol2tp_tunnel *tunnel = session->tunnel;
370 int length = PPPOL2TP_SKB_CB(skb)->length;
371 struct sock *session_sock = NULL;
372
373 /* We're about to requeue the skb, so unlink it and return resources
374 * to its current owner (a socket receive buffer).
375 */
376 skb_unlink(skb, &session->reorder_q);
377 skb_orphan(skb);
378
379 tunnel->stats.rx_packets++;
380 tunnel->stats.rx_bytes += length;
381 session->stats.rx_packets++;
382 session->stats.rx_bytes += length;
383
384 if (PPPOL2TP_SKB_CB(skb)->has_seq) {
385 /* Bump our Nr */
386 session->nr++;
387 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
388 "%s: updated nr to %hu\n", session->name, session->nr);
389 }
390
391 /* If the socket is bound, send it in to PPP's input queue. Otherwise
392 * queue it on the session socket.
393 */
394 session_sock = session->sock;
395 if (session_sock->sk_state & PPPOX_BOUND) {
396 struct pppox_sock *po;
397 PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
398 "%s: recv %d byte data frame, passing to ppp\n",
399 session->name, length);
400
401 /* We need to forget all info related to the L2TP packet
402 * gathered in the skb as we are going to reuse the same
403 * skb for the inner packet.
404 * Namely we need to:
405 * - reset xfrm (IPSec) information as it applies to
406 * the outer L2TP packet and not to the inner one
407 * - release the dst to force a route lookup on the inner
408 * IP packet since skb->dst currently points to the dst
409 * of the UDP tunnel
410 * - reset netfilter information as it doesn't apply
411 * to the inner packet either
412 */
413 secpath_reset(skb);
414 dst_release(skb->dst);
415 skb->dst = NULL;
416 nf_reset(skb);
417
418 po = pppox_sk(session_sock);
419 ppp_input(&po->chan, skb);
420 } else {
421 PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_INFO,
422 "%s: socket not bound\n", session->name);
423
424 /* Not bound. Nothing we can do, so discard. */
425 session->stats.rx_errors++;
426 kfree_skb(skb);
427 }
428
429 sock_put(session->sock);
430}
431
432/* Dequeue skbs from the session's reorder_q, subject to packet order.
433 * Skbs that have been in the queue for too long are simply discarded.
434 */
435static void pppol2tp_recv_dequeue(struct pppol2tp_session *session)
436{
437 struct sk_buff *skb;
438 struct sk_buff *tmp;
439
440 /* If the pkt at the head of the queue has the nr that we
441 * expect to send up next, dequeue it and any other
442 * in-sequence packets behind it.
443 */
444 spin_lock(&session->reorder_q.lock);
445 skb_queue_walk_safe(&session->reorder_q, skb, tmp) {
446 if (time_after(jiffies, PPPOL2TP_SKB_CB(skb)->expires)) {
447 session->stats.rx_seq_discards++;
448 session->stats.rx_errors++;
449 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
450 "%s: oos pkt %hu len %d discarded (too old), "
451 "waiting for %hu, reorder_q_len=%d\n",
452 session->name, PPPOL2TP_SKB_CB(skb)->ns,
453 PPPOL2TP_SKB_CB(skb)->length, session->nr,
454 skb_queue_len(&session->reorder_q));
455 __skb_unlink(skb, &session->reorder_q);
456 kfree_skb(skb);
457 continue;
458 }
459
460 if (PPPOL2TP_SKB_CB(skb)->has_seq) {
461 if (PPPOL2TP_SKB_CB(skb)->ns != session->nr) {
462 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
463 "%s: holding oos pkt %hu len %d, "
464 "waiting for %hu, reorder_q_len=%d\n",
465 session->name, PPPOL2TP_SKB_CB(skb)->ns,
466 PPPOL2TP_SKB_CB(skb)->length, session->nr,
467 skb_queue_len(&session->reorder_q));
468 goto out;
469 }
470 }
471 spin_unlock(&session->reorder_q.lock);
472 pppol2tp_recv_dequeue_skb(session, skb);
473 spin_lock(&session->reorder_q.lock);
474 }
475
476out:
477 spin_unlock(&session->reorder_q.lock);
478}
479
480/* Internal receive frame. Do the real work of receiving an L2TP data frame
481 * here. The skb is not on a list when we get here.
482 * Returns 0 if the packet was a data packet and was successfully passed on.
483 * Returns 1 if the packet was not a good data packet and could not be
484 * forwarded. All such packets are passed up to userspace to deal with.
485 */
486static int pppol2tp_recv_core(struct sock *sock, struct sk_buff *skb)
487{
488 struct pppol2tp_session *session = NULL;
489 struct pppol2tp_tunnel *tunnel;
490 unsigned char *ptr;
491 u16 hdrflags;
492 u16 tunnel_id, session_id;
493 int length;
494 struct udphdr *uh;
495
496 tunnel = pppol2tp_sock_to_tunnel(sock);
497 if (tunnel == NULL)
498 goto error;
499
500 /* Short packet? */
501 if (skb->len < sizeof(struct udphdr)) {
502 PRINTK(tunnel->debug, PPPOL2TP_MSG_DATA, KERN_INFO,
503 "%s: recv short packet (len=%d)\n", tunnel->name, skb->len);
504 goto error;
505 }
506
507 /* Point to L2TP header */
508 ptr = skb->data + sizeof(struct udphdr);
509
510 /* Get L2TP header flags */
511 hdrflags = ntohs(*(__be16*)ptr);
512
513 /* Trace packet contents, if enabled */
514 if (tunnel->debug & PPPOL2TP_MSG_DATA) {
515 printk(KERN_DEBUG "%s: recv: ", tunnel->name);
516
517 for (length = 0; length < 16; length++)
518 printk(" %02X", ptr[length]);
519 printk("\n");
520 }
521
522 /* Get length of L2TP packet */
523 uh = (struct udphdr *) skb_transport_header(skb);
524 length = ntohs(uh->len) - sizeof(struct udphdr);
525
526 /* Too short? */
527 if (length < 12) {
528 PRINTK(tunnel->debug, PPPOL2TP_MSG_DATA, KERN_INFO,
529 "%s: recv short L2TP packet (len=%d)\n", tunnel->name, length);
530 goto error;
531 }
532
533 /* If type is control packet, it is handled by userspace. */
534 if (hdrflags & L2TP_HDRFLAG_T) {
535 PRINTK(tunnel->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
536 "%s: recv control packet, len=%d\n", tunnel->name, length);
537 goto error;
538 }
539
540 /* Skip flags */
541 ptr += 2;
542
543 /* If length is present, skip it */
544 if (hdrflags & L2TP_HDRFLAG_L)
545 ptr += 2;
546
547 /* Extract tunnel and session ID */
548 tunnel_id = ntohs(*(__be16 *) ptr);
549 ptr += 2;
550 session_id = ntohs(*(__be16 *) ptr);
551 ptr += 2;
552
553 /* Find the session context */
554 session = pppol2tp_session_find(tunnel, session_id);
555 if (!session) {
556 /* Not found? Pass to userspace to deal with */
557 PRINTK(tunnel->debug, PPPOL2TP_MSG_DATA, KERN_INFO,
558 "%s: no socket found (%hu/%hu). Passing up.\n",
559 tunnel->name, tunnel_id, session_id);
560 goto error;
561 }
562 sock_hold(session->sock);
563
564 /* The ref count on the socket was increased by the above call since
565 * we now hold a pointer to the session. Take care to do sock_put()
566 * when exiting this function from now on...
567 */
568
569 /* Handle the optional sequence numbers. If we are the LAC,
570 * enable/disable sequence numbers under the control of the LNS. If
571 * no sequence numbers present but we were expecting them, discard
572 * frame.
573 */
574 if (hdrflags & L2TP_HDRFLAG_S) {
575 u16 ns, nr;
576 ns = ntohs(*(__be16 *) ptr);
577 ptr += 2;
578 nr = ntohs(*(__be16 *) ptr);
579 ptr += 2;
580
581 /* Received a packet with sequence numbers. If we're the LNS,
582 * check if we sre sending sequence numbers and if not,
583 * configure it so.
584 */
585 if ((!session->lns_mode) && (!session->send_seq)) {
586 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_INFO,
587 "%s: requested to enable seq numbers by LNS\n",
588 session->name);
589 session->send_seq = -1;
590 }
591
592 /* Store L2TP info in the skb */
593 PPPOL2TP_SKB_CB(skb)->ns = ns;
594 PPPOL2TP_SKB_CB(skb)->nr = nr;
595 PPPOL2TP_SKB_CB(skb)->has_seq = 1;
596
597 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
598 "%s: recv data ns=%hu, nr=%hu, session nr=%hu\n",
599 session->name, ns, nr, session->nr);
600 } else {
601 /* No sequence numbers.
602 * If user has configured mandatory sequence numbers, discard.
603 */
604 if (session->recv_seq) {
605 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_WARNING,
606 "%s: recv data has no seq numbers when required. "
607 "Discarding\n", session->name);
608 session->stats.rx_seq_discards++;
609 session->stats.rx_errors++;
610 goto discard;
611 }
612
613 /* If we're the LAC and we're sending sequence numbers, the
614 * LNS has requested that we no longer send sequence numbers.
615 * If we're the LNS and we're sending sequence numbers, the
616 * LAC is broken. Discard the frame.
617 */
618 if ((!session->lns_mode) && (session->send_seq)) {
619 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_INFO,
620 "%s: requested to disable seq numbers by LNS\n",
621 session->name);
622 session->send_seq = 0;
623 } else if (session->send_seq) {
624 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_WARNING,
625 "%s: recv data has no seq numbers when required. "
626 "Discarding\n", session->name);
627 session->stats.rx_seq_discards++;
628 session->stats.rx_errors++;
629 goto discard;
630 }
631
632 /* Store L2TP info in the skb */
633 PPPOL2TP_SKB_CB(skb)->has_seq = 0;
634 }
635
636 /* If offset bit set, skip it. */
637 if (hdrflags & L2TP_HDRFLAG_O)
638 ptr += 2 + ntohs(*(__be16 *) ptr);
639
640 skb_pull(skb, ptr - skb->data);
641
642 /* Skip PPP header, if present. In testing, Microsoft L2TP clients
643 * don't send the PPP header (PPP header compression enabled), but
644 * other clients can include the header. So we cope with both cases
645 * here. The PPP header is always FF03 when using L2TP.
646 *
647 * Note that skb->data[] isn't dereferenced from a u16 ptr here since
648 * the field may be unaligned.
649 */
650 if ((skb->data[0] == 0xff) && (skb->data[1] == 0x03))
651 skb_pull(skb, 2);
652
653 /* Prepare skb for adding to the session's reorder_q. Hold
654 * packets for max reorder_timeout or 1 second if not
655 * reordering.
656 */
657 PPPOL2TP_SKB_CB(skb)->length = length;
658 PPPOL2TP_SKB_CB(skb)->expires = jiffies +
659 (session->reorder_timeout ? session->reorder_timeout : HZ);
660
661 /* Add packet to the session's receive queue. Reordering is done here, if
662 * enabled. Saved L2TP protocol info is stored in skb->sb[].
663 */
664 if (PPPOL2TP_SKB_CB(skb)->has_seq) {
665 if (session->reorder_timeout != 0) {
666 /* Packet reordering enabled. Add skb to session's
667 * reorder queue, in order of ns.
668 */
669 pppol2tp_recv_queue_skb(session, skb);
670 } else {
671 /* Packet reordering disabled. Discard out-of-sequence
672 * packets
673 */
674 if (PPPOL2TP_SKB_CB(skb)->ns != session->nr) {
675 session->stats.rx_seq_discards++;
676 session->stats.rx_errors++;
677 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
678 "%s: oos pkt %hu len %d discarded, "
679 "waiting for %hu, reorder_q_len=%d\n",
680 session->name, PPPOL2TP_SKB_CB(skb)->ns,
681 PPPOL2TP_SKB_CB(skb)->length, session->nr,
682 skb_queue_len(&session->reorder_q));
683 goto discard;
684 }
685 skb_queue_tail(&session->reorder_q, skb);
686 }
687 } else {
688 /* No sequence numbers. Add the skb to the tail of the
689 * reorder queue. This ensures that it will be
690 * delivered after all previous sequenced skbs.
691 */
692 skb_queue_tail(&session->reorder_q, skb);
693 }
694
695 /* Try to dequeue as many skbs from reorder_q as we can. */
696 pppol2tp_recv_dequeue(session);
697
698 return 0;
699
700discard:
701 kfree_skb(skb);
702 sock_put(session->sock);
703
704 return 0;
705
706error:
707 return 1;
708}
709
710/* UDP encapsulation receive handler. See net/ipv4/udp.c.
711 * Return codes:
712 * 0 : success.
713 * <0: error
714 * >0: skb should be passed up to userspace as UDP.
715 */
716static int pppol2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
717{
718 struct pppol2tp_tunnel *tunnel;
719
720 tunnel = pppol2tp_sock_to_tunnel(sk);
721 if (tunnel == NULL)
722 goto pass_up;
723
724 PRINTK(tunnel->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
725 "%s: received %d bytes\n", tunnel->name, skb->len);
726
727 if (pppol2tp_recv_core(sk, skb))
728 goto pass_up;
729
730 return 0;
731
732pass_up:
733 return 1;
734}
735
736/* Receive message. This is the recvmsg for the PPPoL2TP socket.
737 */
738static int pppol2tp_recvmsg(struct kiocb *iocb, struct socket *sock,
739 struct msghdr *msg, size_t len,
740 int flags)
741{
742 int err;
743 struct sk_buff *skb;
744 struct sock *sk = sock->sk;
745
746 err = -EIO;
747 if (sk->sk_state & PPPOX_BOUND)
748 goto end;
749
750 msg->msg_namelen = 0;
751
752 err = 0;
753 skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
754 flags & MSG_DONTWAIT, &err);
755 if (skb) {
756 err = memcpy_toiovec(msg->msg_iov, (unsigned char *) skb->data,
757 skb->len);
758 if (err < 0)
759 goto do_skb_free;
760 err = skb->len;
761 }
762do_skb_free:
763 kfree_skb(skb);
764end:
765 return err;
766}
767
768/************************************************************************
769 * Transmit handling
770 ***********************************************************************/
771
772/* Tell how big L2TP headers are for a particular session. This
773 * depends on whether sequence numbers are being used.
774 */
775static inline int pppol2tp_l2tp_header_len(struct pppol2tp_session *session)
776{
777 if (session->send_seq)
778 return PPPOL2TP_L2TP_HDR_SIZE_SEQ;
779
780 return PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
781}
782
783/* Build an L2TP header for the session into the buffer provided.
784 */
785static void pppol2tp_build_l2tp_header(struct pppol2tp_session *session,
786 void *buf)
787{
788 __be16 *bufp = buf;
789 u16 flags = L2TP_HDR_VER;
790
791 if (session->send_seq)
792 flags |= L2TP_HDRFLAG_S;
793
794 /* Setup L2TP header.
795 * FIXME: Can this ever be unaligned? Is direct dereferencing of
796 * 16-bit header fields safe here for all architectures?
797 */
798 *bufp++ = htons(flags);
799 *bufp++ = htons(session->tunnel_addr.d_tunnel);
800 *bufp++ = htons(session->tunnel_addr.d_session);
801 if (session->send_seq) {
802 *bufp++ = htons(session->ns);
803 *bufp++ = 0;
804 session->ns++;
805 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
806 "%s: updated ns to %hu\n", session->name, session->ns);
807 }
808}
809
810/* This is the sendmsg for the PPPoL2TP pppol2tp_session socket. We come here
811 * when a user application does a sendmsg() on the session socket. L2TP and
812 * PPP headers must be inserted into the user's data.
813 */
814static int pppol2tp_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
815 size_t total_len)
816{
817 static const unsigned char ppph[2] = { 0xff, 0x03 };
818 struct sock *sk = sock->sk;
819 struct inet_sock *inet;
820 __wsum csum = 0;
821 struct sk_buff *skb;
822 int error;
823 int hdr_len;
824 struct pppol2tp_session *session;
825 struct pppol2tp_tunnel *tunnel;
826 struct udphdr *uh;
827
828 error = -ENOTCONN;
829 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
830 goto error;
831
832 /* Get session and tunnel contexts */
833 error = -EBADF;
834 session = pppol2tp_sock_to_session(sk);
835 if (session == NULL)
836 goto error;
837
838 tunnel = pppol2tp_sock_to_tunnel(session->tunnel_sock);
839 if (tunnel == NULL)
840 goto error;
841
842 /* What header length is configured for this session? */
843 hdr_len = pppol2tp_l2tp_header_len(session);
844
845 /* Allocate a socket buffer */
846 error = -ENOMEM;
847 skb = sock_wmalloc(sk, NET_SKB_PAD + sizeof(struct iphdr) +
848 sizeof(struct udphdr) + hdr_len +
849 sizeof(ppph) + total_len,
850 0, GFP_KERNEL);
851 if (!skb)
852 goto error;
853
854 /* Reserve space for headers. */
855 skb_reserve(skb, NET_SKB_PAD);
856 skb_reset_network_header(skb);
857 skb_reserve(skb, sizeof(struct iphdr));
858 skb_reset_transport_header(skb);
859
860 /* Build UDP header */
861 inet = inet_sk(session->tunnel_sock);
862 uh = (struct udphdr *) skb->data;
863 uh->source = inet->sport;
864 uh->dest = inet->dport;
865 uh->len = htons(hdr_len + sizeof(ppph) + total_len);
866 uh->check = 0;
867 skb_put(skb, sizeof(struct udphdr));
868
869 /* Build L2TP header */
870 pppol2tp_build_l2tp_header(session, skb->data);
871 skb_put(skb, hdr_len);
872
873 /* Add PPP header */
874 skb->data[0] = ppph[0];
875 skb->data[1] = ppph[1];
876 skb_put(skb, 2);
877
878 /* Copy user data into skb */
879 error = memcpy_fromiovec(skb->data, m->msg_iov, total_len);
880 if (error < 0) {
881 kfree_skb(skb);
882 goto error;
883 }
884 skb_put(skb, total_len);
885
886 /* Calculate UDP checksum if configured to do so */
887 if (session->tunnel_sock->sk_no_check != UDP_CSUM_NOXMIT)
888 csum = udp_csum_outgoing(sk, skb);
889
890 /* Debug */
891 if (session->send_seq)
892 PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
893 "%s: send %d bytes, ns=%hu\n", session->name,
894 total_len, session->ns - 1);
895 else
896 PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
897 "%s: send %d bytes\n", session->name, total_len);
898
899 if (session->debug & PPPOL2TP_MSG_DATA) {
900 int i;
901 unsigned char *datap = skb->data;
902
903 printk(KERN_DEBUG "%s: xmit:", session->name);
904 for (i = 0; i < total_len; i++) {
905 printk(" %02X", *datap++);
906 if (i == 15) {
907 printk(" ...");
908 break;
909 }
910 }
911 printk("\n");
912 }
913
914 /* Queue the packet to IP for output */
915 error = ip_queue_xmit(skb, 1);
916
917 /* Update stats */
918 if (error >= 0) {
919 tunnel->stats.tx_packets++;
920 tunnel->stats.tx_bytes += skb->len;
921 session->stats.tx_packets++;
922 session->stats.tx_bytes += skb->len;
923 } else {
924 tunnel->stats.tx_errors++;
925 session->stats.tx_errors++;
926 }
927
928error:
929 return error;
930}
931
932/* Transmit function called by generic PPP driver. Sends PPP frame
933 * over PPPoL2TP socket.
934 *
935 * This is almost the same as pppol2tp_sendmsg(), but rather than
936 * being called with a msghdr from userspace, it is called with a skb
937 * from the kernel.
938 *
939 * The supplied skb from ppp doesn't have enough headroom for the
940 * insertion of L2TP, UDP and IP headers so we need to allocate more
941 * headroom in the skb. This will create a cloned skb. But we must be
942 * careful in the error case because the caller will expect to free
943 * the skb it supplied, not our cloned skb. So we take care to always
944 * leave the original skb unfreed if we return an error.
945 */
946static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
947{
948 static const u8 ppph[2] = { 0xff, 0x03 };
949 struct sock *sk = (struct sock *) chan->private;
950 struct sock *sk_tun;
951 int hdr_len;
952 struct pppol2tp_session *session;
953 struct pppol2tp_tunnel *tunnel;
954 int rc;
955 int headroom;
956 int data_len = skb->len;
957 struct inet_sock *inet;
958 __wsum csum = 0;
959 struct sk_buff *skb2 = NULL;
960 struct udphdr *uh;
961
962 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
963 goto abort;
964
965 /* Get session and tunnel contexts from the socket */
966 session = pppol2tp_sock_to_session(sk);
967 if (session == NULL)
968 goto abort;
969
970 sk_tun = session->tunnel_sock;
971 if (sk_tun == NULL)
972 goto abort;
973 tunnel = pppol2tp_sock_to_tunnel(sk_tun);
974 if (tunnel == NULL)
975 goto abort;
976
977 /* What header length is configured for this session? */
978 hdr_len = pppol2tp_l2tp_header_len(session);
979
980 /* Check that there's enough headroom in the skb to insert IP,
981 * UDP and L2TP and PPP headers. If not enough, expand it to
982 * make room. Note that a new skb (or a clone) is
983 * allocated. If we return an error from this point on, make
984 * sure we free the new skb but do not free the original skb
985 * since that is done by the caller for the error case.
986 */
987 headroom = NET_SKB_PAD + sizeof(struct iphdr) +
988 sizeof(struct udphdr) + hdr_len + sizeof(ppph);
989 if (skb_headroom(skb) < headroom) {
990 skb2 = skb_realloc_headroom(skb, headroom);
991 if (skb2 == NULL)
992 goto abort;
993 } else
994 skb2 = skb;
995
996 /* Check that the socket has room */
997 if (atomic_read(&sk_tun->sk_wmem_alloc) < sk_tun->sk_sndbuf)
998 skb_set_owner_w(skb2, sk_tun);
999 else
1000 goto discard;
1001
1002 /* Setup PPP header */
1003 skb_push(skb2, sizeof(ppph));
1004 skb2->data[0] = ppph[0];
1005 skb2->data[1] = ppph[1];
1006
1007 /* Setup L2TP header */
1008 skb_push(skb2, hdr_len);
1009 pppol2tp_build_l2tp_header(session, skb2->data);
1010
1011 /* Setup UDP header */
1012 inet = inet_sk(sk_tun);
1013 skb_push(skb2, sizeof(struct udphdr));
1014 skb_reset_transport_header(skb2);
1015 uh = (struct udphdr *) skb2->data;
1016 uh->source = inet->sport;
1017 uh->dest = inet->dport;
1018 uh->len = htons(sizeof(struct udphdr) + hdr_len + sizeof(ppph) + data_len);
1019 uh->check = 0;
1020
1021 /* Calculate UDP checksum if configured to do so */
1022 if (sk_tun->sk_no_check != UDP_CSUM_NOXMIT)
1023 csum = udp_csum_outgoing(sk_tun, skb2);
1024
1025 /* Debug */
1026 if (session->send_seq)
1027 PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
1028 "%s: send %d bytes, ns=%hu\n", session->name,
1029 data_len, session->ns - 1);
1030 else
1031 PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
1032 "%s: send %d bytes\n", session->name, data_len);
1033
1034 if (session->debug & PPPOL2TP_MSG_DATA) {
1035 int i;
1036 unsigned char *datap = skb2->data;
1037
1038 printk(KERN_DEBUG "%s: xmit:", session->name);
1039 for (i = 0; i < data_len; i++) {
1040 printk(" %02X", *datap++);
1041 if (i == 31) {
1042 printk(" ...");
1043 break;
1044 }
1045 }
1046 printk("\n");
1047 }
1048
1049 /* Get routing info from the tunnel socket */
1050 skb2->dst = sk_dst_get(sk_tun);
1051
1052 /* Queue the packet to IP for output */
1053 rc = ip_queue_xmit(skb2, 1);
1054
1055 /* Update stats */
1056 if (rc >= 0) {
1057 tunnel->stats.tx_packets++;
1058 tunnel->stats.tx_bytes += skb2->len;
1059 session->stats.tx_packets++;
1060 session->stats.tx_bytes += skb2->len;
1061 } else {
1062 tunnel->stats.tx_errors++;
1063 session->stats.tx_errors++;
1064 }
1065
1066 /* Free the original skb */
1067 kfree_skb(skb);
1068
1069 return 1;
1070
1071discard:
1072 /* Free the new skb. Caller will free original skb. */
1073 if (skb2 != skb)
1074 kfree_skb(skb2);
1075abort:
1076 return 0;
1077}
1078
1079/*****************************************************************************
1080 * Session (and tunnel control) socket create/destroy.
1081 *****************************************************************************/
1082
1083/* When the tunnel UDP socket is closed, all the attached sockets need to go
1084 * too.
1085 */
1086static void pppol2tp_tunnel_closeall(struct pppol2tp_tunnel *tunnel)
1087{
1088 int hash;
1089 struct hlist_node *walk;
1090 struct hlist_node *tmp;
1091 struct pppol2tp_session *session;
1092 struct sock *sk;
1093
1094 if (tunnel == NULL)
1095 BUG();
1096
1097 PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1098 "%s: closing all sessions...\n", tunnel->name);
1099
1100 write_lock(&tunnel->hlist_lock);
1101 for (hash = 0; hash < PPPOL2TP_HASH_SIZE; hash++) {
1102again:
1103 hlist_for_each_safe(walk, tmp, &tunnel->session_hlist[hash]) {
1104 session = hlist_entry(walk, struct pppol2tp_session, hlist);
1105
1106 sk = session->sock;
1107
1108 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1109 "%s: closing session\n", session->name);
1110
1111 hlist_del_init(&session->hlist);
1112
1113 /* Since we should hold the sock lock while
1114 * doing any unbinding, we need to release the
1115 * lock we're holding before taking that lock.
1116 * Hold a reference to the sock so it doesn't
1117 * disappear as we're jumping between locks.
1118 */
1119 sock_hold(sk);
1120 write_unlock(&tunnel->hlist_lock);
1121 lock_sock(sk);
1122
1123 if (sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND)) {
1124 pppox_unbind_sock(sk);
1125 sk->sk_state = PPPOX_DEAD;
1126 sk->sk_state_change(sk);
1127 }
1128
1129 /* Purge any queued data */
1130 skb_queue_purge(&sk->sk_receive_queue);
1131 skb_queue_purge(&sk->sk_write_queue);
1132 skb_queue_purge(&session->reorder_q);
1133
1134 release_sock(sk);
1135 sock_put(sk);
1136
1137 /* Now restart from the beginning of this hash
1138 * chain. We always remove a session from the
1139 * list so we are guaranteed to make forward
1140 * progress.
1141 */
1142 write_lock(&tunnel->hlist_lock);
1143 goto again;
1144 }
1145 }
1146 write_unlock(&tunnel->hlist_lock);
1147}
1148
1149/* Really kill the tunnel.
1150 * Come here only when all sessions have been cleared from the tunnel.
1151 */
1152static void pppol2tp_tunnel_free(struct pppol2tp_tunnel *tunnel)
1153{
1154 /* Remove from socket list */
1155 write_lock(&pppol2tp_tunnel_list_lock);
1156 list_del_init(&tunnel->list);
1157 write_unlock(&pppol2tp_tunnel_list_lock);
1158
1159 atomic_dec(&pppol2tp_tunnel_count);
1160 kfree(tunnel);
1161}
1162
1163/* Tunnel UDP socket destruct hook.
1164 * The tunnel context is deleted only when all session sockets have been
1165 * closed.
1166 */
1167static void pppol2tp_tunnel_destruct(struct sock *sk)
1168{
1169 struct pppol2tp_tunnel *tunnel;
1170
1171 tunnel = pppol2tp_sock_to_tunnel(sk);
1172 if (tunnel == NULL)
1173 goto end;
1174
1175 PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1176 "%s: closing...\n", tunnel->name);
1177
1178 /* Close all sessions */
1179 pppol2tp_tunnel_closeall(tunnel);
1180
1181 /* No longer an encapsulation socket. See net/ipv4/udp.c */
1182 (udp_sk(sk))->encap_type = 0;
1183 (udp_sk(sk))->encap_rcv = NULL;
1184
1185 /* Remove hooks into tunnel socket */
1186 tunnel->sock = NULL;
1187 sk->sk_destruct = tunnel->old_sk_destruct;
1188 sk->sk_user_data = NULL;
1189
1190 /* Call original (UDP) socket descructor */
1191 if (sk->sk_destruct != NULL)
1192 (*sk->sk_destruct)(sk);
1193
1194 pppol2tp_tunnel_dec_refcount(tunnel);
1195
1196end:
1197 return;
1198}
1199
1200/* Really kill the session socket. (Called from sock_put() if
1201 * refcnt == 0.)
1202 */
1203static void pppol2tp_session_destruct(struct sock *sk)
1204{
1205 struct pppol2tp_session *session = NULL;
1206
1207 if (sk->sk_user_data != NULL) {
1208 struct pppol2tp_tunnel *tunnel;
1209
1210 session = pppol2tp_sock_to_session(sk);
1211 if (session == NULL)
1212 goto out;
1213
1214 /* Don't use pppol2tp_sock_to_tunnel() here to
1215 * get the tunnel context because the tunnel
1216 * socket might have already been closed (its
1217 * sk->sk_user_data will be NULL) so use the
1218 * session's private tunnel ptr instead.
1219 */
1220 tunnel = session->tunnel;
1221 if (tunnel != NULL) {
1222 BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);
1223
1224 /* If session_id is zero, this is a null
1225 * session context, which was created for a
1226 * socket that is being used only to manage
1227 * tunnels.
1228 */
1229 if (session->tunnel_addr.s_session != 0) {
1230 /* Delete the session socket from the
1231 * hash
1232 */
1233 write_lock(&tunnel->hlist_lock);
1234 hlist_del_init(&session->hlist);
1235 write_unlock(&tunnel->hlist_lock);
1236
1237 atomic_dec(&pppol2tp_session_count);
1238 }
1239
1240 /* This will delete the tunnel context if this
1241 * is the last session on the tunnel.
1242 */
1243 session->tunnel = NULL;
1244 session->tunnel_sock = NULL;
1245 pppol2tp_tunnel_dec_refcount(tunnel);
1246 }
1247 }
1248
1249 kfree(session);
1250out:
1251 return;
1252}
1253
1254/* Called when the PPPoX socket (session) is closed.
1255 */
1256static int pppol2tp_release(struct socket *sock)
1257{
1258 struct sock *sk = sock->sk;
1259 int error;
1260
1261 if (!sk)
1262 return 0;
1263
1264 error = -EBADF;
1265 lock_sock(sk);
1266 if (sock_flag(sk, SOCK_DEAD) != 0)
1267 goto error;
1268
1269 pppox_unbind_sock(sk);
1270
1271 /* Signal the death of the socket. */
1272 sk->sk_state = PPPOX_DEAD;
1273 sock_orphan(sk);
1274 sock->sk = NULL;
1275
1276 /* Purge any queued data */
1277 skb_queue_purge(&sk->sk_receive_queue);
1278 skb_queue_purge(&sk->sk_write_queue);
1279
1280 release_sock(sk);
1281
1282 /* This will delete the session context via
1283 * pppol2tp_session_destruct() if the socket's refcnt drops to
1284 * zero.
1285 */
1286 sock_put(sk);
1287
1288 return 0;
1289
1290error:
1291 release_sock(sk);
1292 return error;
1293}
1294
1295/* Internal function to prepare a tunnel (UDP) socket to have PPPoX
1296 * sockets attached to it.
1297 */
1298static struct sock *pppol2tp_prepare_tunnel_socket(int fd, u16 tunnel_id,
1299 int *error)
1300{
1301 int err;
1302 struct socket *sock = NULL;
1303 struct sock *sk;
1304 struct pppol2tp_tunnel *tunnel;
1305 struct sock *ret = NULL;
1306
1307 /* Get the tunnel UDP socket from the fd, which was opened by
1308 * the userspace L2TP daemon.
1309 */
1310 err = -EBADF;
1311 sock = sockfd_lookup(fd, &err);
1312 if (!sock) {
1313 PRINTK(-1, PPPOL2TP_MSG_CONTROL, KERN_ERR,
1314 "tunl %hu: sockfd_lookup(fd=%d) returned %d\n",
1315 tunnel_id, fd, err);
1316 goto err;
1317 }
1318
1319 /* Quick sanity checks */
1320 err = -ESOCKTNOSUPPORT;
1321 if (sock->type != SOCK_DGRAM) {
1322 PRINTK(-1, PPPOL2TP_MSG_CONTROL, KERN_ERR,
1323 "tunl %hu: fd %d wrong type, got %d, expected %d\n",
1324 tunnel_id, fd, sock->type, SOCK_DGRAM);
1325 goto err;
1326 }
1327 err = -EAFNOSUPPORT;
1328 if (sock->ops->family != AF_INET) {
1329 PRINTK(-1, PPPOL2TP_MSG_CONTROL, KERN_ERR,
1330 "tunl %hu: fd %d wrong family, got %d, expected %d\n",
1331 tunnel_id, fd, sock->ops->family, AF_INET);
1332 goto err;
1333 }
1334
1335 err = -ENOTCONN;
1336 sk = sock->sk;
1337
1338 /* Check if this socket has already been prepped */
1339 tunnel = (struct pppol2tp_tunnel *)sk->sk_user_data;
1340 if (tunnel != NULL) {
1341 /* User-data field already set */
1342 err = -EBUSY;
1343 BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);
1344
1345 /* This socket has already been prepped */
1346 ret = tunnel->sock;
1347 goto out;
1348 }
1349
1350 /* This socket is available and needs prepping. Create a new tunnel
1351 * context and init it.
1352 */
1353 sk->sk_user_data = tunnel = kzalloc(sizeof(struct pppol2tp_tunnel), GFP_KERNEL);
1354 if (sk->sk_user_data == NULL) {
1355 err = -ENOMEM;
1356 goto err;
1357 }
1358
1359 tunnel->magic = L2TP_TUNNEL_MAGIC;
1360 sprintf(&tunnel->name[0], "tunl %hu", tunnel_id);
1361
1362 tunnel->stats.tunnel_id = tunnel_id;
1363 tunnel->debug = PPPOL2TP_DEFAULT_DEBUG_FLAGS;
1364
1365 /* Hook on the tunnel socket destructor so that we can cleanup
1366 * if the tunnel socket goes away.
1367 */
1368 tunnel->old_sk_destruct = sk->sk_destruct;
1369 sk->sk_destruct = &pppol2tp_tunnel_destruct;
1370
1371 tunnel->sock = sk;
1372 sk->sk_allocation = GFP_ATOMIC;
1373
1374 /* Misc init */
1375 rwlock_init(&tunnel->hlist_lock);
1376
1377 /* Add tunnel to our list */
1378 INIT_LIST_HEAD(&tunnel->list);
1379 write_lock(&pppol2tp_tunnel_list_lock);
1380 list_add(&tunnel->list, &pppol2tp_tunnel_list);
1381 write_unlock(&pppol2tp_tunnel_list_lock);
1382 atomic_inc(&pppol2tp_tunnel_count);
1383
1384 /* Bump the reference count. The tunnel context is deleted
1385 * only when this drops to zero.
1386 */
1387 pppol2tp_tunnel_inc_refcount(tunnel);
1388
1389 /* Mark socket as an encapsulation socket. See net/ipv4/udp.c */
1390 (udp_sk(sk))->encap_type = UDP_ENCAP_L2TPINUDP;
1391 (udp_sk(sk))->encap_rcv = pppol2tp_udp_encap_recv;
1392
1393 ret = tunnel->sock;
1394
1395 *error = 0;
1396out:
1397 if (sock)
1398 sockfd_put(sock);
1399
1400 return ret;
1401
1402err:
1403 *error = err;
1404 goto out;
1405}
1406
1407static struct proto pppol2tp_sk_proto = {
1408 .name = "PPPOL2TP",
1409 .owner = THIS_MODULE,
1410 .obj_size = sizeof(struct pppox_sock),
1411};
1412
1413/* socket() handler. Initialize a new struct sock.
1414 */
1415static int pppol2tp_create(struct socket *sock)
1416{
1417 int error = -ENOMEM;
1418 struct sock *sk;
1419
1420 sk = sk_alloc(PF_PPPOX, GFP_KERNEL, &pppol2tp_sk_proto, 1);
1421 if (!sk)
1422 goto out;
1423
1424 sock_init_data(sock, sk);
1425
1426 sock->state = SS_UNCONNECTED;
1427 sock->ops = &pppol2tp_ops;
1428
1429 sk->sk_backlog_rcv = pppol2tp_recv_core;
1430 sk->sk_protocol = PX_PROTO_OL2TP;
1431 sk->sk_family = PF_PPPOX;
1432 sk->sk_state = PPPOX_NONE;
1433 sk->sk_type = SOCK_STREAM;
1434 sk->sk_destruct = pppol2tp_session_destruct;
1435
1436 error = 0;
1437
1438out:
1439 return error;
1440}
1441
1442/* connect() handler. Attach a PPPoX socket to a tunnel UDP socket
1443 */
1444static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr,
1445 int sockaddr_len, int flags)
1446{
1447 struct sock *sk = sock->sk;
1448 struct sockaddr_pppol2tp *sp = (struct sockaddr_pppol2tp *) uservaddr;
1449 struct pppox_sock *po = pppox_sk(sk);
1450 struct sock *tunnel_sock = NULL;
1451 struct pppol2tp_session *session = NULL;
1452 struct pppol2tp_tunnel *tunnel;
1453 struct dst_entry *dst;
1454 int error = 0;
1455
1456 lock_sock(sk);
1457
1458 error = -EINVAL;
1459 if (sp->sa_protocol != PX_PROTO_OL2TP)
1460 goto end;
1461
1462 /* Check for already bound sockets */
1463 error = -EBUSY;
1464 if (sk->sk_state & PPPOX_CONNECTED)
1465 goto end;
1466
1467 /* We don't supporting rebinding anyway */
1468 error = -EALREADY;
1469 if (sk->sk_user_data)
1470 goto end; /* socket is already attached */
1471
1472 /* Don't bind if s_tunnel is 0 */
1473 error = -EINVAL;
1474 if (sp->pppol2tp.s_tunnel == 0)
1475 goto end;
1476
1477 /* Special case: prepare tunnel socket if s_session and
1478 * d_session is 0. Otherwise look up tunnel using supplied
1479 * tunnel id.
1480 */
1481 if ((sp->pppol2tp.s_session == 0) && (sp->pppol2tp.d_session == 0)) {
1482 tunnel_sock = pppol2tp_prepare_tunnel_socket(sp->pppol2tp.fd,
1483 sp->pppol2tp.s_tunnel,
1484 &error);
1485 if (tunnel_sock == NULL)
1486 goto end;
1487
1488 tunnel = tunnel_sock->sk_user_data;
1489 } else {
1490 tunnel = pppol2tp_tunnel_find(sp->pppol2tp.s_tunnel);
1491
1492 /* Error if we can't find the tunnel */
1493 error = -ENOENT;
1494 if (tunnel == NULL)
1495 goto end;
1496
1497 tunnel_sock = tunnel->sock;
1498 }
1499
1500 /* Check that this session doesn't already exist */
1501 error = -EEXIST;
1502 session = pppol2tp_session_find(tunnel, sp->pppol2tp.s_session);
1503 if (session != NULL)
1504 goto end;
1505
1506 /* Allocate and initialize a new session context. */
1507 session = kzalloc(sizeof(struct pppol2tp_session), GFP_KERNEL);
1508 if (session == NULL) {
1509 error = -ENOMEM;
1510 goto end;
1511 }
1512
1513 skb_queue_head_init(&session->reorder_q);
1514
1515 session->magic = L2TP_SESSION_MAGIC;
1516 session->owner = current->pid;
1517 session->sock = sk;
1518 session->tunnel = tunnel;
1519 session->tunnel_sock = tunnel_sock;
1520 session->tunnel_addr = sp->pppol2tp;
1521 sprintf(&session->name[0], "sess %hu/%hu",
1522 session->tunnel_addr.s_tunnel,
1523 session->tunnel_addr.s_session);
1524
1525 session->stats.tunnel_id = session->tunnel_addr.s_tunnel;
1526 session->stats.session_id = session->tunnel_addr.s_session;
1527
1528 INIT_HLIST_NODE(&session->hlist);
1529
1530 /* Inherit debug options from tunnel */
1531 session->debug = tunnel->debug;
1532
1533 /* Default MTU must allow space for UDP/L2TP/PPP
1534 * headers.
1535 */
1536 session->mtu = session->mru = 1500 - PPPOL2TP_HEADER_OVERHEAD;
1537
1538 /* If PMTU discovery was enabled, use the MTU that was discovered */
1539 dst = sk_dst_get(sk);
1540 if (dst != NULL) {
1541 u32 pmtu = dst_mtu(__sk_dst_get(sk));
1542 if (pmtu != 0)
1543 session->mtu = session->mru = pmtu -
1544 PPPOL2TP_HEADER_OVERHEAD;
1545 dst_release(dst);
1546 }
1547
1548 /* Special case: if source & dest session_id == 0x0000, this socket is
1549 * being created to manage the tunnel. Don't add the session to the
1550 * session hash list, just set up the internal context for use by
1551 * ioctl() and sockopt() handlers.
1552 */
1553 if ((session->tunnel_addr.s_session == 0) &&
1554 (session->tunnel_addr.d_session == 0)) {
1555 error = 0;
1556 sk->sk_user_data = session;
1557 goto out_no_ppp;
1558 }
1559
1560 /* Get tunnel context from the tunnel socket */
1561 tunnel = pppol2tp_sock_to_tunnel(tunnel_sock);
1562 if (tunnel == NULL) {
1563 error = -EBADF;
1564 goto end;
1565 }
1566
1567 /* Right now, because we don't have a way to push the incoming skb's
1568 * straight through the UDP layer, the only header we need to worry
1569 * about is the L2TP header. This size is different depending on
1570 * whether sequence numbers are enabled for the data channel.
1571 */
1572 po->chan.hdrlen = PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
1573
1574 po->chan.private = sk;
1575 po->chan.ops = &pppol2tp_chan_ops;
1576 po->chan.mtu = session->mtu;
1577
1578 error = ppp_register_channel(&po->chan);
1579 if (error)
1580 goto end;
1581
1582 /* This is how we get the session context from the socket. */
1583 sk->sk_user_data = session;
1584
1585 /* Add session to the tunnel's hash list */
1586 write_lock(&tunnel->hlist_lock);
1587 hlist_add_head(&session->hlist,
1588 pppol2tp_session_id_hash(tunnel,
1589 session->tunnel_addr.s_session));
1590 write_unlock(&tunnel->hlist_lock);
1591
1592 atomic_inc(&pppol2tp_session_count);
1593
1594out_no_ppp:
1595 pppol2tp_tunnel_inc_refcount(tunnel);
1596 sk->sk_state = PPPOX_CONNECTED;
1597 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1598 "%s: created\n", session->name);
1599
1600end:
1601 release_sock(sk);
1602
1603 if (error != 0)
1604 PRINTK(session ? session->debug : -1, PPPOL2TP_MSG_CONTROL, KERN_WARNING,
1605 "%s: connect failed: %d\n", session->name, error);
1606
1607 return error;
1608}
1609
1610/* getname() support.
1611 */
1612static int pppol2tp_getname(struct socket *sock, struct sockaddr *uaddr,
1613 int *usockaddr_len, int peer)
1614{
1615 int len = sizeof(struct sockaddr_pppol2tp);
1616 struct sockaddr_pppol2tp sp;
1617 int error = 0;
1618 struct pppol2tp_session *session;
1619
1620 error = -ENOTCONN;
1621 if (sock->sk->sk_state != PPPOX_CONNECTED)
1622 goto end;
1623
1624 session = pppol2tp_sock_to_session(sock->sk);
1625 if (session == NULL) {
1626 error = -EBADF;
1627 goto end;
1628 }
1629
1630 sp.sa_family = AF_PPPOX;
1631 sp.sa_protocol = PX_PROTO_OL2TP;
1632 memcpy(&sp.pppol2tp, &session->tunnel_addr,
1633 sizeof(struct pppol2tp_addr));
1634
1635 memcpy(uaddr, &sp, len);
1636
1637 *usockaddr_len = len;
1638
1639 error = 0;
1640
1641end:
1642 return error;
1643}
1644
1645/****************************************************************************
1646 * ioctl() handlers.
1647 *
1648 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
1649 * sockets. However, in order to control kernel tunnel features, we allow
1650 * userspace to create a special "tunnel" PPPoX socket which is used for
1651 * control only. Tunnel PPPoX sockets have session_id == 0 and simply allow
1652 * the user application to issue L2TP setsockopt(), getsockopt() and ioctl()
1653 * calls.
1654 ****************************************************************************/
1655
1656/* Session ioctl helper.
1657 */
1658static int pppol2tp_session_ioctl(struct pppol2tp_session *session,
1659 unsigned int cmd, unsigned long arg)
1660{
1661 struct ifreq ifr;
1662 int err = 0;
1663 struct sock *sk = session->sock;
1664 int val = (int) arg;
1665
1666 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_DEBUG,
1667 "%s: pppol2tp_session_ioctl(cmd=%#x, arg=%#lx)\n",
1668 session->name, cmd, arg);
1669
1670 sock_hold(sk);
1671
1672 switch (cmd) {
1673 case SIOCGIFMTU:
1674 err = -ENXIO;
1675 if (!(sk->sk_state & PPPOX_CONNECTED))
1676 break;
1677
1678 err = -EFAULT;
1679 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq)))
1680 break;
1681 ifr.ifr_mtu = session->mtu;
1682 if (copy_to_user((void __user *) arg, &ifr, sizeof(struct ifreq)))
1683 break;
1684
1685 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1686 "%s: get mtu=%d\n", session->name, session->mtu);
1687 err = 0;
1688 break;
1689
1690 case SIOCSIFMTU:
1691 err = -ENXIO;
1692 if (!(sk->sk_state & PPPOX_CONNECTED))
1693 break;
1694
1695 err = -EFAULT;
1696 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq)))
1697 break;
1698
1699 session->mtu = ifr.ifr_mtu;
1700
1701 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1702 "%s: set mtu=%d\n", session->name, session->mtu);
1703 err = 0;
1704 break;
1705
1706 case PPPIOCGMRU:
1707 err = -ENXIO;
1708 if (!(sk->sk_state & PPPOX_CONNECTED))
1709 break;
1710
1711 err = -EFAULT;
1712 if (put_user(session->mru, (int __user *) arg))
1713 break;
1714
1715 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1716 "%s: get mru=%d\n", session->name, session->mru);
1717 err = 0;
1718 break;
1719
1720 case PPPIOCSMRU:
1721 err = -ENXIO;
1722 if (!(sk->sk_state & PPPOX_CONNECTED))
1723 break;
1724
1725 err = -EFAULT;
1726 if (get_user(val,(int __user *) arg))
1727 break;
1728
1729 session->mru = val;
1730 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1731 "%s: set mru=%d\n", session->name, session->mru);
1732 err = 0;
1733 break;
1734
1735 case PPPIOCGFLAGS:
1736 err = -EFAULT;
1737 if (put_user(session->flags, (int __user *) arg))
1738 break;
1739
1740 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1741 "%s: get flags=%d\n", session->name, session->flags);
1742 err = 0;
1743 break;
1744
1745 case PPPIOCSFLAGS:
1746 err = -EFAULT;
1747 if (get_user(val, (int __user *) arg))
1748 break;
1749 session->flags = val;
1750 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1751 "%s: set flags=%d\n", session->name, session->flags);
1752 err = 0;
1753 break;
1754
1755 case PPPIOCGL2TPSTATS:
1756 err = -ENXIO;
1757 if (!(sk->sk_state & PPPOX_CONNECTED))
1758 break;
1759
1760 if (copy_to_user((void __user *) arg, &session->stats,
1761 sizeof(session->stats)))
1762 break;
1763 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1764 "%s: get L2TP stats\n", session->name);
1765 err = 0;
1766 break;
1767
1768 default:
1769 err = -ENOSYS;
1770 break;
1771 }
1772
1773 sock_put(sk);
1774
1775 return err;
1776}
1777
1778/* Tunnel ioctl helper.
1779 *
1780 * Note the special handling for PPPIOCGL2TPSTATS below. If the ioctl data
1781 * specifies a session_id, the session ioctl handler is called. This allows an
1782 * application to retrieve session stats via a tunnel socket.
1783 */
1784static int pppol2tp_tunnel_ioctl(struct pppol2tp_tunnel *tunnel,
1785 unsigned int cmd, unsigned long arg)
1786{
1787 int err = 0;
1788 struct sock *sk = tunnel->sock;
1789 struct pppol2tp_ioc_stats stats_req;
1790
1791 PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_DEBUG,
1792 "%s: pppol2tp_tunnel_ioctl(cmd=%#x, arg=%#lx)\n", tunnel->name,
1793 cmd, arg);
1794
1795 sock_hold(sk);
1796
1797 switch (cmd) {
1798 case PPPIOCGL2TPSTATS:
1799 err = -ENXIO;
1800 if (!(sk->sk_state & PPPOX_CONNECTED))
1801 break;
1802
1803 if (copy_from_user(&stats_req, (void __user *) arg,
1804 sizeof(stats_req))) {
1805 err = -EFAULT;
1806 break;
1807 }
1808 if (stats_req.session_id != 0) {
1809 /* resend to session ioctl handler */
1810 struct pppol2tp_session *session =
1811 pppol2tp_session_find(tunnel, stats_req.session_id);
1812 if (session != NULL)
1813 err = pppol2tp_session_ioctl(session, cmd, arg);
1814 else
1815 err = -EBADR;
1816 break;
1817 }
1818#ifdef CONFIG_XFRM
1819 tunnel->stats.using_ipsec = (sk->sk_policy[0] || sk->sk_policy[1]) ? 1 : 0;
1820#endif
1821 if (copy_to_user((void __user *) arg, &tunnel->stats,
1822 sizeof(tunnel->stats))) {
1823 err = -EFAULT;
1824 break;
1825 }
1826 PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1827 "%s: get L2TP stats\n", tunnel->name);
1828 err = 0;
1829 break;
1830
1831 default:
1832 err = -ENOSYS;
1833 break;
1834 }
1835
1836 sock_put(sk);
1837
1838 return err;
1839}
1840
1841/* Main ioctl() handler.
1842 * Dispatch to tunnel or session helpers depending on the socket.
1843 */
1844static int pppol2tp_ioctl(struct socket *sock, unsigned int cmd,
1845 unsigned long arg)
1846{
1847 struct sock *sk = sock->sk;
1848 struct pppol2tp_session *session;
1849 struct pppol2tp_tunnel *tunnel;
1850 int err;
1851
1852 if (!sk)
1853 return 0;
1854
1855 err = -EBADF;
1856 if (sock_flag(sk, SOCK_DEAD) != 0)
1857 goto end;
1858
1859 err = -ENOTCONN;
1860 if ((sk->sk_user_data == NULL) ||
1861 (!(sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND))))
1862 goto end;
1863
1864 /* Get session context from the socket */
1865 err = -EBADF;
1866 session = pppol2tp_sock_to_session(sk);
1867 if (session == NULL)
1868 goto end;
1869
1870 /* Special case: if session's session_id is zero, treat ioctl as a
1871 * tunnel ioctl
1872 */
1873 if ((session->tunnel_addr.s_session == 0) &&
1874 (session->tunnel_addr.d_session == 0)) {
1875 err = -EBADF;
1876 tunnel = pppol2tp_sock_to_tunnel(session->tunnel_sock);
1877 if (tunnel == NULL)
1878 goto end;
1879
1880 err = pppol2tp_tunnel_ioctl(tunnel, cmd, arg);
1881 goto end;
1882 }
1883
1884 err = pppol2tp_session_ioctl(session, cmd, arg);
1885
1886end:
1887 return err;
1888}
1889
1890/*****************************************************************************
1891 * setsockopt() / getsockopt() support.
1892 *
1893 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
1894 * sockets. In order to control kernel tunnel features, we allow userspace to
1895 * create a special "tunnel" PPPoX socket which is used for control only.
1896 * Tunnel PPPoX sockets have session_id == 0 and simply allow the user
1897 * application to issue L2TP setsockopt(), getsockopt() and ioctl() calls.
1898 *****************************************************************************/
1899
1900/* Tunnel setsockopt() helper.
1901 */
1902static int pppol2tp_tunnel_setsockopt(struct sock *sk,
1903 struct pppol2tp_tunnel *tunnel,
1904 int optname, int val)
1905{
1906 int err = 0;
1907
1908 switch (optname) {
1909 case PPPOL2TP_SO_DEBUG:
1910 tunnel->debug = val;
1911 PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1912 "%s: set debug=%x\n", tunnel->name, tunnel->debug);
1913 break;
1914
1915 default:
1916 err = -ENOPROTOOPT;
1917 break;
1918 }
1919
1920 return err;
1921}
1922
1923/* Session setsockopt helper.
1924 */
1925static int pppol2tp_session_setsockopt(struct sock *sk,
1926 struct pppol2tp_session *session,
1927 int optname, int val)
1928{
1929 int err = 0;
1930
1931 switch (optname) {
1932 case PPPOL2TP_SO_RECVSEQ:
1933 if ((val != 0) && (val != 1)) {
1934 err = -EINVAL;
1935 break;
1936 }
1937 session->recv_seq = val ? -1 : 0;
1938 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1939 "%s: set recv_seq=%d\n", session->name,
1940 session->recv_seq);
1941 break;
1942
1943 case PPPOL2TP_SO_SENDSEQ:
1944 if ((val != 0) && (val != 1)) {
1945 err = -EINVAL;
1946 break;
1947 }
1948 session->send_seq = val ? -1 : 0;
1949 {
1950 struct sock *ssk = session->sock;
1951 struct pppox_sock *po = pppox_sk(ssk);
1952 po->chan.hdrlen = val ? PPPOL2TP_L2TP_HDR_SIZE_SEQ :
1953 PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
1954 }
1955 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1956 "%s: set send_seq=%d\n", session->name, session->send_seq);
1957 break;
1958
1959 case PPPOL2TP_SO_LNSMODE:
1960 if ((val != 0) && (val != 1)) {
1961 err = -EINVAL;
1962 break;
1963 }
1964 session->lns_mode = val ? -1 : 0;
1965 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1966 "%s: set lns_mode=%d\n", session->name,
1967 session->lns_mode);
1968 break;
1969
1970 case PPPOL2TP_SO_DEBUG:
1971 session->debug = val;
1972 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1973 "%s: set debug=%x\n", session->name, session->debug);
1974 break;
1975
1976 case PPPOL2TP_SO_REORDERTO:
1977 session->reorder_timeout = msecs_to_jiffies(val);
1978 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1979 "%s: set reorder_timeout=%d\n", session->name,
1980 session->reorder_timeout);
1981 break;
1982
1983 default:
1984 err = -ENOPROTOOPT;
1985 break;
1986 }
1987
1988 return err;
1989}
1990
1991/* Main setsockopt() entry point.
1992 * Does API checks, then calls either the tunnel or session setsockopt
1993 * handler, according to whether the PPPoL2TP socket is a for a regular
1994 * session or the special tunnel type.
1995 */
1996static int pppol2tp_setsockopt(struct socket *sock, int level, int optname,
1997 char __user *optval, int optlen)
1998{
1999 struct sock *sk = sock->sk;
2000 struct pppol2tp_session *session = sk->sk_user_data;
2001 struct pppol2tp_tunnel *tunnel;
2002 int val;
2003 int err;
2004
2005 if (level != SOL_PPPOL2TP)
2006 return udp_prot.setsockopt(sk, level, optname, optval, optlen);
2007
2008 if (optlen < sizeof(int))
2009 return -EINVAL;
2010
2011 if (get_user(val, (int __user *)optval))
2012 return -EFAULT;
2013
2014 err = -ENOTCONN;
2015 if (sk->sk_user_data == NULL)
2016 goto end;
2017
2018 /* Get session context from the socket */
2019 err = -EBADF;
2020 session = pppol2tp_sock_to_session(sk);
2021 if (session == NULL)
2022 goto end;
2023
2024 /* Special case: if session_id == 0x0000, treat as operation on tunnel
2025 */
2026 if ((session->tunnel_addr.s_session == 0) &&
2027 (session->tunnel_addr.d_session == 0)) {
2028 err = -EBADF;
2029 tunnel = pppol2tp_sock_to_tunnel(session->tunnel_sock);
2030 if (tunnel == NULL)
2031 goto end;
2032
2033 err = pppol2tp_tunnel_setsockopt(sk, tunnel, optname, val);
2034 } else
2035 err = pppol2tp_session_setsockopt(sk, session, optname, val);
2036
2037 err = 0;
2038
2039end:
2040 return err;
2041}
2042
2043/* Tunnel getsockopt helper. Called with sock locked.
2044 */
2045static int pppol2tp_tunnel_getsockopt(struct sock *sk,
2046 struct pppol2tp_tunnel *tunnel,
2047 int optname, int __user *val)
2048{
2049 int err = 0;
2050
2051 switch (optname) {
2052 case PPPOL2TP_SO_DEBUG:
2053 *val = tunnel->debug;
2054 PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2055 "%s: get debug=%x\n", tunnel->name, tunnel->debug);
2056 break;
2057
2058 default:
2059 err = -ENOPROTOOPT;
2060 break;
2061 }
2062
2063 return err;
2064}
2065
2066/* Session getsockopt helper. Called with sock locked.
2067 */
2068static int pppol2tp_session_getsockopt(struct sock *sk,
2069 struct pppol2tp_session *session,
2070 int optname, int __user *val)
2071{
2072 int err = 0;
2073
2074 switch (optname) {
2075 case PPPOL2TP_SO_RECVSEQ:
2076 *val = session->recv_seq;
2077 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2078 "%s: get recv_seq=%d\n", session->name, *val);
2079 break;
2080
2081 case PPPOL2TP_SO_SENDSEQ:
2082 *val = session->send_seq;
2083 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2084 "%s: get send_seq=%d\n", session->name, *val);
2085 break;
2086
2087 case PPPOL2TP_SO_LNSMODE:
2088 *val = session->lns_mode;
2089 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2090 "%s: get lns_mode=%d\n", session->name, *val);
2091 break;
2092
2093 case PPPOL2TP_SO_DEBUG:
2094 *val = session->debug;
2095 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2096 "%s: get debug=%d\n", session->name, *val);
2097 break;
2098
2099 case PPPOL2TP_SO_REORDERTO:
2100 *val = (int) jiffies_to_msecs(session->reorder_timeout);
2101 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2102 "%s: get reorder_timeout=%d\n", session->name, *val);
2103 break;
2104
2105 default:
2106 err = -ENOPROTOOPT;
2107 }
2108
2109 return err;
2110}
2111
2112/* Main getsockopt() entry point.
2113 * Does API checks, then calls either the tunnel or session getsockopt
2114 * handler, according to whether the PPPoX socket is a for a regular session
2115 * or the special tunnel type.
2116 */
2117static int pppol2tp_getsockopt(struct socket *sock, int level,
2118 int optname, char __user *optval, int __user *optlen)
2119{
2120 struct sock *sk = sock->sk;
2121 struct pppol2tp_session *session = sk->sk_user_data;
2122 struct pppol2tp_tunnel *tunnel;
2123 int val, len;
2124 int err;
2125
2126 if (level != SOL_PPPOL2TP)
2127 return udp_prot.getsockopt(sk, level, optname, optval, optlen);
2128
2129 if (get_user(len, (int __user *) optlen))
2130 return -EFAULT;
2131
2132 len = min_t(unsigned int, len, sizeof(int));
2133
2134 if (len < 0)
2135 return -EINVAL;
2136
2137 err = -ENOTCONN;
2138 if (sk->sk_user_data == NULL)
2139 goto end;
2140
2141 /* Get the session context */
2142 err = -EBADF;
2143 session = pppol2tp_sock_to_session(sk);
2144 if (session == NULL)
2145 goto end;
2146
2147 /* Special case: if session_id == 0x0000, treat as operation on tunnel */
2148 if ((session->tunnel_addr.s_session == 0) &&
2149 (session->tunnel_addr.d_session == 0)) {
2150 err = -EBADF;
2151 tunnel = pppol2tp_sock_to_tunnel(session->tunnel_sock);
2152 if (tunnel == NULL)
2153 goto end;
2154
2155 err = pppol2tp_tunnel_getsockopt(sk, tunnel, optname, &val);
2156 } else
2157 err = pppol2tp_session_getsockopt(sk, session, optname, &val);
2158
2159 err = -EFAULT;
2160 if (put_user(len, (int __user *) optlen))
2161 goto end;
2162
2163 if (copy_to_user((void __user *) optval, &val, len))
2164 goto end;
2165
2166 err = 0;
2167end:
2168 return err;
2169}
2170
2171/*****************************************************************************
2172 * /proc filesystem for debug
2173 *****************************************************************************/
2174
2175#ifdef CONFIG_PROC_FS
2176
2177#include <linux/seq_file.h>
2178
2179struct pppol2tp_seq_data {
2180 struct pppol2tp_tunnel *tunnel; /* current tunnel */
2181 struct pppol2tp_session *session; /* NULL means get first session in tunnel */
2182};
2183
2184static struct pppol2tp_session *next_session(struct pppol2tp_tunnel *tunnel, struct pppol2tp_session *curr)
2185{
2186 struct pppol2tp_session *session = NULL;
2187 struct hlist_node *walk;
2188 int found = 0;
2189 int next = 0;
2190 int i;
2191
2192 read_lock(&tunnel->hlist_lock);
2193 for (i = 0; i < PPPOL2TP_HASH_SIZE; i++) {
2194 hlist_for_each_entry(session, walk, &tunnel->session_hlist[i], hlist) {
2195 if (curr == NULL) {
2196 found = 1;
2197 goto out;
2198 }
2199 if (session == curr) {
2200 next = 1;
2201 continue;
2202 }
2203 if (next) {
2204 found = 1;
2205 goto out;
2206 }
2207 }
2208 }
2209out:
2210 read_unlock(&tunnel->hlist_lock);
2211 if (!found)
2212 session = NULL;
2213
2214 return session;
2215}
2216
2217static struct pppol2tp_tunnel *next_tunnel(struct pppol2tp_tunnel *curr)
2218{
2219 struct pppol2tp_tunnel *tunnel = NULL;
2220
2221 read_lock(&pppol2tp_tunnel_list_lock);
2222 if (list_is_last(&curr->list, &pppol2tp_tunnel_list)) {
2223 goto out;
2224 }
2225 tunnel = list_entry(curr->list.next, struct pppol2tp_tunnel, list);
2226out:
2227 read_unlock(&pppol2tp_tunnel_list_lock);
2228
2229 return tunnel;
2230}
2231
2232static void *pppol2tp_seq_start(struct seq_file *m, loff_t *offs)
2233{
2234 struct pppol2tp_seq_data *pd = SEQ_START_TOKEN;
2235 loff_t pos = *offs;
2236
2237 if (!pos)
2238 goto out;
2239
2240 BUG_ON(m->private == NULL);
2241 pd = m->private;
2242
2243 if (pd->tunnel == NULL) {
2244 if (!list_empty(&pppol2tp_tunnel_list))
2245 pd->tunnel = list_entry(pppol2tp_tunnel_list.next, struct pppol2tp_tunnel, list);
2246 } else {
2247 pd->session = next_session(pd->tunnel, pd->session);
2248 if (pd->session == NULL) {
2249 pd->tunnel = next_tunnel(pd->tunnel);
2250 }
2251 }
2252
2253 /* NULL tunnel and session indicates end of list */
2254 if ((pd->tunnel == NULL) && (pd->session == NULL))
2255 pd = NULL;
2256
2257out:
2258 return pd;
2259}
2260
2261static void *pppol2tp_seq_next(struct seq_file *m, void *v, loff_t *pos)
2262{
2263 (*pos)++;
2264 return NULL;
2265}
2266
2267static void pppol2tp_seq_stop(struct seq_file *p, void *v)
2268{
2269 /* nothing to do */
2270}
2271
2272static void pppol2tp_seq_tunnel_show(struct seq_file *m, void *v)
2273{
2274 struct pppol2tp_tunnel *tunnel = v;
2275
2276 seq_printf(m, "\nTUNNEL '%s', %c %d\n",
2277 tunnel->name,
2278 (tunnel == tunnel->sock->sk_user_data) ? 'Y':'N',
2279 atomic_read(&tunnel->ref_count) - 1);
2280 seq_printf(m, " %08x %llu/%llu/%llu %llu/%llu/%llu\n",
2281 tunnel->debug,
2282 tunnel->stats.tx_packets, tunnel->stats.tx_bytes,
2283 tunnel->stats.tx_errors,
2284 tunnel->stats.rx_packets, tunnel->stats.rx_bytes,
2285 tunnel->stats.rx_errors);
2286}
2287
2288static void pppol2tp_seq_session_show(struct seq_file *m, void *v)
2289{
2290 struct pppol2tp_session *session = v;
2291
2292 seq_printf(m, " SESSION '%s' %08X/%d %04X/%04X -> "
2293 "%04X/%04X %d %c\n",
2294 session->name,
2295 ntohl(session->tunnel_addr.addr.sin_addr.s_addr),
2296 ntohs(session->tunnel_addr.addr.sin_port),
2297 session->tunnel_addr.s_tunnel,
2298 session->tunnel_addr.s_session,
2299 session->tunnel_addr.d_tunnel,
2300 session->tunnel_addr.d_session,
2301 session->sock->sk_state,
2302 (session == session->sock->sk_user_data) ?
2303 'Y' : 'N');
2304 seq_printf(m, " %d/%d/%c/%c/%s %08x %u\n",
2305 session->mtu, session->mru,
2306 session->recv_seq ? 'R' : '-',
2307 session->send_seq ? 'S' : '-',
2308 session->lns_mode ? "LNS" : "LAC",
2309 session->debug,
2310 jiffies_to_msecs(session->reorder_timeout));
2311 seq_printf(m, " %hu/%hu %llu/%llu/%llu %llu/%llu/%llu\n",
2312 session->nr, session->ns,
2313 session->stats.tx_packets,
2314 session->stats.tx_bytes,
2315 session->stats.tx_errors,
2316 session->stats.rx_packets,
2317 session->stats.rx_bytes,
2318 session->stats.rx_errors);
2319}
2320
2321static int pppol2tp_seq_show(struct seq_file *m, void *v)
2322{
2323 struct pppol2tp_seq_data *pd = v;
2324
2325 /* display header on line 1 */
2326 if (v == SEQ_START_TOKEN) {
2327 seq_puts(m, "PPPoL2TP driver info, " PPPOL2TP_DRV_VERSION "\n");
2328 seq_puts(m, "TUNNEL name, user-data-ok session-count\n");
2329 seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
2330 seq_puts(m, " SESSION name, addr/port src-tid/sid "
2331 "dest-tid/sid state user-data-ok\n");
2332 seq_puts(m, " mtu/mru/rcvseq/sendseq/lns debug reorderto\n");
2333 seq_puts(m, " nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
2334 goto out;
2335 }
2336
2337 /* Show the tunnel or session context.
2338 */
2339 if (pd->session == NULL)
2340 pppol2tp_seq_tunnel_show(m, pd->tunnel);
2341 else
2342 pppol2tp_seq_session_show(m, pd->session);
2343
2344out:
2345 return 0;
2346}
2347
2348static struct seq_operations pppol2tp_seq_ops = {
2349 .start = pppol2tp_seq_start,
2350 .next = pppol2tp_seq_next,
2351 .stop = pppol2tp_seq_stop,
2352 .show = pppol2tp_seq_show,
2353};
2354
2355/* Called when our /proc file is opened. We allocate data for use when
2356 * iterating our tunnel / session contexts and store it in the private
2357 * data of the seq_file.
2358 */
2359static int pppol2tp_proc_open(struct inode *inode, struct file *file)
2360{
2361 struct seq_file *m;
2362 struct pppol2tp_seq_data *pd;
2363 int ret = 0;
2364
2365 ret = seq_open(file, &pppol2tp_seq_ops);
2366 if (ret < 0)
2367 goto out;
2368
2369 m = file->private_data;
2370
2371 /* Allocate and fill our proc_data for access later */
2372 ret = -ENOMEM;
2373 m->private = kzalloc(sizeof(struct pppol2tp_seq_data), GFP_KERNEL);
2374 if (m->private == NULL)
2375 goto out;
2376
2377 pd = m->private;
2378 ret = 0;
2379
2380out:
2381 return ret;
2382}
2383
2384/* Called when /proc file access completes.
2385 */
2386static int pppol2tp_proc_release(struct inode *inode, struct file *file)
2387{
2388 struct seq_file *m = (struct seq_file *)file->private_data;
2389
2390 kfree(m->private);
2391 m->private = NULL;
2392
2393 return seq_release(inode, file);
2394}
2395
2396static struct file_operations pppol2tp_proc_fops = {
2397 .owner = THIS_MODULE,
2398 .open = pppol2tp_proc_open,
2399 .read = seq_read,
2400 .llseek = seq_lseek,
2401 .release = pppol2tp_proc_release,
2402};
2403
2404static struct proc_dir_entry *pppol2tp_proc;
2405
2406#endif /* CONFIG_PROC_FS */
2407
2408/*****************************************************************************
2409 * Init and cleanup
2410 *****************************************************************************/
2411
2412static struct proto_ops pppol2tp_ops = {
2413 .family = AF_PPPOX,
2414 .owner = THIS_MODULE,
2415 .release = pppol2tp_release,
2416 .bind = sock_no_bind,
2417 .connect = pppol2tp_connect,
2418 .socketpair = sock_no_socketpair,
2419 .accept = sock_no_accept,
2420 .getname = pppol2tp_getname,
2421 .poll = datagram_poll,
2422 .listen = sock_no_listen,
2423 .shutdown = sock_no_shutdown,
2424 .setsockopt = pppol2tp_setsockopt,
2425 .getsockopt = pppol2tp_getsockopt,
2426 .sendmsg = pppol2tp_sendmsg,
2427 .recvmsg = pppol2tp_recvmsg,
2428 .mmap = sock_no_mmap,
2429 .ioctl = pppox_ioctl,
2430};
2431
2432static struct pppox_proto pppol2tp_proto = {
2433 .create = pppol2tp_create,
2434 .ioctl = pppol2tp_ioctl
2435};
2436
2437static int __init pppol2tp_init(void)
2438{
2439 int err;
2440
2441 err = proto_register(&pppol2tp_sk_proto, 0);
2442 if (err)
2443 goto out;
2444 err = register_pppox_proto(PX_PROTO_OL2TP, &pppol2tp_proto);
2445 if (err)
2446 goto out_unregister_pppol2tp_proto;
2447
2448#ifdef CONFIG_PROC_FS
2449 pppol2tp_proc = create_proc_entry("pppol2tp", 0, proc_net);
2450 if (!pppol2tp_proc) {
2451 err = -ENOMEM;
2452 goto out_unregister_pppox_proto;
2453 }
2454 pppol2tp_proc->proc_fops = &pppol2tp_proc_fops;
2455#endif /* CONFIG_PROC_FS */
2456 printk(KERN_INFO "PPPoL2TP kernel driver, %s\n",
2457 PPPOL2TP_DRV_VERSION);
2458
2459out:
2460 return err;
2461
2462out_unregister_pppox_proto:
2463 unregister_pppox_proto(PX_PROTO_OL2TP);
2464out_unregister_pppol2tp_proto:
2465 proto_unregister(&pppol2tp_sk_proto);
2466 goto out;
2467}
2468
2469static void __exit pppol2tp_exit(void)
2470{
2471 unregister_pppox_proto(PX_PROTO_OL2TP);
2472
2473#ifdef CONFIG_PROC_FS
2474 remove_proc_entry("pppol2tp", proc_net);
2475#endif
2476 proto_unregister(&pppol2tp_sk_proto);
2477}
2478
2479module_init(pppol2tp_init);
2480module_exit(pppol2tp_exit);
2481
2482MODULE_AUTHOR("Martijn van Oosterhout <kleptog@svana.org>,"
2483 "James Chapman <jchapman@katalix.com>");
2484MODULE_DESCRIPTION("PPP over L2TP over UDP");
2485MODULE_LICENSE("GPL");
2486MODULE_VERSION(PPPOL2TP_DRV_VERSION);
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-01 21:50:15 -0500