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ARM: dts: imx51: Add M4IF support
[linux/fpc-iii.git] / net / l2tp / l2tp_ppp.c
blob55188382845c310c98eb86cdfc3b78e1d03e8e0f
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: 2.0.0
8 *
9 * Authors: James Chapman (jchapman@katalix.com)
10 *
11 * Based on original work by Martijn van Oosterhout <kleptog@svana.org>
12 *
13 * License:
14 * This program is free software; you can redistribute it and/or
15 * modify it under the terms of the GNU General Public License
16 * as published by the Free Software Foundation; either version
17 * 2 of the License, or (at your option) any later version.
18 *
19 */
20
21 /* This driver handles only L2TP data frames; control frames are handled by a
22 * userspace application.
23 *
24 * To send data in an L2TP session, userspace opens a PPPoL2TP socket and
25 * attaches it to a bound UDP socket with local tunnel_id / session_id and
26 * peer tunnel_id / session_id set. Data can then be sent or received using
27 * regular socket sendmsg() / recvmsg() calls. Kernel parameters of the socket
28 * can be read or modified using ioctl() or [gs]etsockopt() calls.
29 *
30 * When a PPPoL2TP socket is connected with local and peer session_id values
31 * zero, the socket is treated as a special tunnel management socket.
32 *
33 * Here's example userspace code to create a socket for sending/receiving data
34 * over an L2TP session:-
35 *
36 * struct sockaddr_pppol2tp sax;
37 * int fd;
38 * int session_fd;
39 *
40 * fd = socket(AF_PPPOX, SOCK_DGRAM, PX_PROTO_OL2TP);
41 *
42 * sax.sa_family = AF_PPPOX;
43 * sax.sa_protocol = PX_PROTO_OL2TP;
44 * sax.pppol2tp.fd = tunnel_fd; // bound UDP socket
45 * sax.pppol2tp.addr.sin_addr.s_addr = addr->sin_addr.s_addr;
46 * sax.pppol2tp.addr.sin_port = addr->sin_port;
47 * sax.pppol2tp.addr.sin_family = AF_INET;
48 * sax.pppol2tp.s_tunnel = tunnel_id;
49 * sax.pppol2tp.s_session = session_id;
50 * sax.pppol2tp.d_tunnel = peer_tunnel_id;
51 * sax.pppol2tp.d_session = peer_session_id;
52 *
53 * session_fd = connect(fd, (struct sockaddr *)&sax, sizeof(sax));
54 *
55 * A pppd plugin that allows PPP traffic to be carried over L2TP using
56 * this driver is available from the OpenL2TP project at
57 * http://openl2tp.sourceforge.net.
58 */
59
60 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
61
62 #include <linux/module.h>
63 #include <linux/string.h>
64 #include <linux/list.h>
65 #include <linux/uaccess.h>
66
67 #include <linux/kernel.h>
68 #include <linux/spinlock.h>
69 #include <linux/kthread.h>
70 #include <linux/sched.h>
71 #include <linux/slab.h>
72 #include <linux/errno.h>
73 #include <linux/jiffies.h>
74
75 #include <linux/netdevice.h>
76 #include <linux/net.h>
77 #include <linux/inetdevice.h>
78 #include <linux/skbuff.h>
79 #include <linux/init.h>
80 #include <linux/ip.h>
81 #include <linux/udp.h>
82 #include <linux/if_pppox.h>
83 #include <linux/if_pppol2tp.h>
84 #include <net/sock.h>
85 #include <linux/ppp_channel.h>
86 #include <linux/ppp_defs.h>
87 #include <linux/ppp-ioctl.h>
88 #include <linux/file.h>
89 #include <linux/hash.h>
90 #include <linux/sort.h>
91 #include <linux/proc_fs.h>
92 #include <linux/l2tp.h>
93 #include <linux/nsproxy.h>
94 #include <net/net_namespace.h>
95 #include <net/netns/generic.h>
96 #include <net/dst.h>
97 #include <net/ip.h>
98 #include <net/udp.h>
99 #include <net/xfrm.h>
100 #include <net/inet_common.h>
101
102 #include <asm/byteorder.h>
103 #include <linux/atomic.h>
104
105 #include "l2tp_core.h"
106
107 #define PPPOL2TP_DRV_VERSION "V2.0"
108
109 /* Space for UDP, L2TP and PPP headers */
110 #define PPPOL2TP_HEADER_OVERHEAD 40
111
112 /* Number of bytes to build transmit L2TP headers.
113 * Unfortunately the size is different depending on whether sequence numbers
114 * are enabled.
115 */
116 #define PPPOL2TP_L2TP_HDR_SIZE_SEQ 10
117 #define PPPOL2TP_L2TP_HDR_SIZE_NOSEQ 6
118
119 /* Private data of each session. This data lives at the end of struct
120 * l2tp_session, referenced via session->priv[].
121 */
122 struct pppol2tp_session {
123 int owner; /* pid that opened the socket */
124
125 struct mutex sk_lock; /* Protects .sk */
126 struct sock __rcu *sk; /* Pointer to the session
127 * PPPoX socket */
128 struct sock *__sk; /* Copy of .sk, for cleanup */
129 struct rcu_head rcu; /* For asynchronous release */
130 int flags; /* accessed by PPPIOCGFLAGS.
131 * Unused. */
132 };
133
134 static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb);
135
136 static const struct ppp_channel_ops pppol2tp_chan_ops = {
137 .start_xmit = pppol2tp_xmit,
138 };
139
140 static const struct proto_ops pppol2tp_ops;
141
142 /* Retrieves the pppol2tp socket associated to a session.
143 * A reference is held on the returned socket, so this function must be paired
144 * with sock_put().
145 */
146 static struct sock *pppol2tp_session_get_sock(struct l2tp_session *session)
147 {
148 struct pppol2tp_session *ps = l2tp_session_priv(session);
149 struct sock *sk;
150
151 rcu_read_lock();
152 sk = rcu_dereference(ps->sk);
153 if (sk)
154 sock_hold(sk);
155 rcu_read_unlock();
156
157 return sk;
158 }
159
160 /* Helpers to obtain tunnel/session contexts from sockets.
161 */
162 static inline struct l2tp_session *pppol2tp_sock_to_session(struct sock *sk)
163 {
164 struct l2tp_session *session;
165
166 if (sk == NULL)
167 return NULL;
168
169 sock_hold(sk);
170 session = (struct l2tp_session *)(sk->sk_user_data);
171 if (session == NULL) {
172 sock_put(sk);
173 goto out;
174 }
175
176 BUG_ON(session->magic != L2TP_SESSION_MAGIC);
177
178 out:
179 return session;
180 }
181
182 /*****************************************************************************
183 * Receive data handling
184 *****************************************************************************/
185
186 static int pppol2tp_recv_payload_hook(struct sk_buff *skb)
187 {
188 /* Skip PPP header, if present. In testing, Microsoft L2TP clients
189 * don't send the PPP header (PPP header compression enabled), but
190 * other clients can include the header. So we cope with both cases
191 * here. The PPP header is always FF03 when using L2TP.
192 *
193 * Note that skb->data[] isn't dereferenced from a u16 ptr here since
194 * the field may be unaligned.
195 */
196 if (!pskb_may_pull(skb, 2))
197 return 1;
198
199 if ((skb->data[0] == PPP_ALLSTATIONS) && (skb->data[1] == PPP_UI))
200 skb_pull(skb, 2);
201
202 return 0;
203 }
204
205 /* Receive message. This is the recvmsg for the PPPoL2TP socket.
206 */
207 static int pppol2tp_recvmsg(struct socket *sock, struct msghdr *msg,
208 size_t len, int flags)
209 {
210 int err;
211 struct sk_buff *skb;
212 struct sock *sk = sock->sk;
213
214 err = -EIO;
215 if (sk->sk_state & PPPOX_BOUND)
216 goto end;
217
218 err = 0;
219 skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
220 flags & MSG_DONTWAIT, &err);
221 if (!skb)
222 goto end;
223
224 if (len > skb->len)
225 len = skb->len;
226 else if (len < skb->len)
227 msg->msg_flags |= MSG_TRUNC;
228
229 err = skb_copy_datagram_msg(skb, 0, msg, len);
230 if (likely(err == 0))
231 err = len;
232
233 kfree_skb(skb);
234 end:
235 return err;
236 }
237
238 static void pppol2tp_recv(struct l2tp_session *session, struct sk_buff *skb, int data_len)
239 {
240 struct pppol2tp_session *ps = l2tp_session_priv(session);
241 struct sock *sk = NULL;
242
243 /* If the socket is bound, send it in to PPP's input queue. Otherwise
244 * queue it on the session socket.
245 */
246 rcu_read_lock();
247 sk = rcu_dereference(ps->sk);
248 if (sk == NULL)
249 goto no_sock;
250
251 if (sk->sk_state & PPPOX_BOUND) {
252 struct pppox_sock *po;
253
254 l2tp_dbg(session, L2TP_MSG_DATA,
255 "%s: recv %d byte data frame, passing to ppp\n",
256 session->name, data_len);
257
258 po = pppox_sk(sk);
259 ppp_input(&po->chan, skb);
260 } else {
261 l2tp_dbg(session, L2TP_MSG_DATA,
262 "%s: recv %d byte data frame, passing to L2TP socket\n",
263 session->name, data_len);
264
265 if (sock_queue_rcv_skb(sk, skb) < 0) {
266 atomic_long_inc(&session->stats.rx_errors);
267 kfree_skb(skb);
268 }
269 }
270 rcu_read_unlock();
271
272 return;
273
274 no_sock:
275 rcu_read_unlock();
276 l2tp_info(session, L2TP_MSG_DATA, "%s: no socket\n", session->name);
277 kfree_skb(skb);
278 }
279
280 /************************************************************************
281 * Transmit handling
282 ***********************************************************************/
283
284 /* This is the sendmsg for the PPPoL2TP pppol2tp_session socket. We come here
285 * when a user application does a sendmsg() on the session socket. L2TP and
286 * PPP headers must be inserted into the user's data.
287 */
288 static int pppol2tp_sendmsg(struct socket *sock, struct msghdr *m,
289 size_t total_len)
290 {
291 struct sock *sk = sock->sk;
292 struct sk_buff *skb;
293 int error;
294 struct l2tp_session *session;
295 struct l2tp_tunnel *tunnel;
296 int uhlen;
297
298 error = -ENOTCONN;
299 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
300 goto error;
301
302 /* Get session and tunnel contexts */
303 error = -EBADF;
304 session = pppol2tp_sock_to_session(sk);
305 if (session == NULL)
306 goto error;
307
308 tunnel = session->tunnel;
309
310 uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0;
311
312 /* Allocate a socket buffer */
313 error = -ENOMEM;
314 skb = sock_wmalloc(sk, NET_SKB_PAD + sizeof(struct iphdr) +
315 uhlen + session->hdr_len +
316 2 + total_len, /* 2 bytes for PPP_ALLSTATIONS & PPP_UI */
317 0, GFP_KERNEL);
318 if (!skb)
319 goto error_put_sess;
320
321 /* Reserve space for headers. */
322 skb_reserve(skb, NET_SKB_PAD);
323 skb_reset_network_header(skb);
324 skb_reserve(skb, sizeof(struct iphdr));
325 skb_reset_transport_header(skb);
326 skb_reserve(skb, uhlen);
327
328 /* Add PPP header */
329 skb->data[0] = PPP_ALLSTATIONS;
330 skb->data[1] = PPP_UI;
331 skb_put(skb, 2);
332
333 /* Copy user data into skb */
334 error = memcpy_from_msg(skb_put(skb, total_len), m, total_len);
335 if (error < 0) {
336 kfree_skb(skb);
337 goto error_put_sess;
338 }
339
340 local_bh_disable();
341 l2tp_xmit_skb(session, skb, session->hdr_len);
342 local_bh_enable();
343
344 sock_put(sk);
345
346 return total_len;
347
348 error_put_sess:
349 sock_put(sk);
350 error:
351 return error;
352 }
353
354 /* Transmit function called by generic PPP driver. Sends PPP frame
355 * over PPPoL2TP socket.
356 *
357 * This is almost the same as pppol2tp_sendmsg(), but rather than
358 * being called with a msghdr from userspace, it is called with a skb
359 * from the kernel.
360 *
361 * The supplied skb from ppp doesn't have enough headroom for the
362 * insertion of L2TP, UDP and IP headers so we need to allocate more
363 * headroom in the skb. This will create a cloned skb. But we must be
364 * careful in the error case because the caller will expect to free
365 * the skb it supplied, not our cloned skb. So we take care to always
366 * leave the original skb unfreed if we return an error.
367 */
368 static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
369 {
370 struct sock *sk = (struct sock *) chan->private;
371 struct l2tp_session *session;
372 struct l2tp_tunnel *tunnel;
373 int uhlen, headroom;
374
375 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
376 goto abort;
377
378 /* Get session and tunnel contexts from the socket */
379 session = pppol2tp_sock_to_session(sk);
380 if (session == NULL)
381 goto abort;
382
383 tunnel = session->tunnel;
384
385 uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0;
386 headroom = NET_SKB_PAD +
387 sizeof(struct iphdr) + /* IP header */
388 uhlen + /* UDP header (if L2TP_ENCAPTYPE_UDP) */
389 session->hdr_len + /* L2TP header */
390 2; /* 2 bytes for PPP_ALLSTATIONS & PPP_UI */
391 if (skb_cow_head(skb, headroom))
392 goto abort_put_sess;
393
394 /* Setup PPP header */
395 __skb_push(skb, 2);
396 skb->data[0] = PPP_ALLSTATIONS;
397 skb->data[1] = PPP_UI;
398
399 local_bh_disable();
400 l2tp_xmit_skb(session, skb, session->hdr_len);
401 local_bh_enable();
402
403 sock_put(sk);
404
405 return 1;
406
407 abort_put_sess:
408 sock_put(sk);
409 abort:
410 /* Free the original skb */
411 kfree_skb(skb);
412 return 1;
413 }
414
415 /*****************************************************************************
416 * Session (and tunnel control) socket create/destroy.
417 *****************************************************************************/
418
419 static void pppol2tp_put_sk(struct rcu_head *head)
420 {
421 struct pppol2tp_session *ps;
422
423 ps = container_of(head, typeof(*ps), rcu);
424 sock_put(ps->__sk);
425 }
426
427 /* Called by l2tp_core when a session socket is being closed.
428 */
429 static void pppol2tp_session_close(struct l2tp_session *session)
430 {
431 }
432
433 /* Really kill the session socket. (Called from sock_put() if
434 * refcnt == 0.)
435 */
436 static void pppol2tp_session_destruct(struct sock *sk)
437 {
438 struct l2tp_session *session = sk->sk_user_data;
439
440 skb_queue_purge(&sk->sk_receive_queue);
441 skb_queue_purge(&sk->sk_write_queue);
442
443 if (session) {
444 sk->sk_user_data = NULL;
445 BUG_ON(session->magic != L2TP_SESSION_MAGIC);
446 l2tp_session_dec_refcount(session);
447 }
448 }
449
450 /* Called when the PPPoX socket (session) is closed.
451 */
452 static int pppol2tp_release(struct socket *sock)
453 {
454 struct sock *sk = sock->sk;
455 struct l2tp_session *session;
456 int error;
457
458 if (!sk)
459 return 0;
460
461 error = -EBADF;
462 lock_sock(sk);
463 if (sock_flag(sk, SOCK_DEAD) != 0)
464 goto error;
465
466 pppox_unbind_sock(sk);
467
468 /* Signal the death of the socket. */
469 sk->sk_state = PPPOX_DEAD;
470 sock_orphan(sk);
471 sock->sk = NULL;
472
473 session = pppol2tp_sock_to_session(sk);
474 if (session) {
475 struct pppol2tp_session *ps;
476
477 l2tp_session_delete(session);
478
479 ps = l2tp_session_priv(session);
480 mutex_lock(&ps->sk_lock);
481 ps->__sk = rcu_dereference_protected(ps->sk,
482 lockdep_is_held(&ps->sk_lock));
483 RCU_INIT_POINTER(ps->sk, NULL);
484 mutex_unlock(&ps->sk_lock);
485 call_rcu(&ps->rcu, pppol2tp_put_sk);
486
487 /* Rely on the sock_put() call at the end of the function for
488 * dropping the reference held by pppol2tp_sock_to_session().
489 * The last reference will be dropped by pppol2tp_put_sk().
490 */
491 }
492
493 release_sock(sk);
494
495 /* This will delete the session context via
496 * pppol2tp_session_destruct() if the socket's refcnt drops to
497 * zero.
498 */
499 sock_put(sk);
500
501 return 0;
502
503 error:
504 release_sock(sk);
505 return error;
506 }
507
508 static struct proto pppol2tp_sk_proto = {
509 .name = "PPPOL2TP",
510 .owner = THIS_MODULE,
511 .obj_size = sizeof(struct pppox_sock),
512 };
513
514 static int pppol2tp_backlog_recv(struct sock *sk, struct sk_buff *skb)
515 {
516 int rc;
517
518 rc = l2tp_udp_encap_recv(sk, skb);
519 if (rc)
520 kfree_skb(skb);
521
522 return NET_RX_SUCCESS;
523 }
524
525 /* socket() handler. Initialize a new struct sock.
526 */
527 static int pppol2tp_create(struct net *net, struct socket *sock, int kern)
528 {
529 int error = -ENOMEM;
530 struct sock *sk;
531
532 sk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, &pppol2tp_sk_proto, kern);
533 if (!sk)
534 goto out;
535
536 sock_init_data(sock, sk);
537
538 sock->state = SS_UNCONNECTED;
539 sock->ops = &pppol2tp_ops;
540
541 sk->sk_backlog_rcv = pppol2tp_backlog_recv;
542 sk->sk_protocol = PX_PROTO_OL2TP;
543 sk->sk_family = PF_PPPOX;
544 sk->sk_state = PPPOX_NONE;
545 sk->sk_type = SOCK_STREAM;
546 sk->sk_destruct = pppol2tp_session_destruct;
547
548 error = 0;
549
550 out:
551 return error;
552 }
553
554 #if IS_ENABLED(CONFIG_L2TP_DEBUGFS)
555 static void pppol2tp_show(struct seq_file *m, void *arg)
556 {
557 struct l2tp_session *session = arg;
558 struct sock *sk;
559
560 sk = pppol2tp_session_get_sock(session);
561 if (sk) {
562 struct pppox_sock *po = pppox_sk(sk);
563
564 seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan));
565 sock_put(sk);
566 }
567 }
568 #endif
569
570 static void pppol2tp_session_init(struct l2tp_session *session)
571 {
572 struct pppol2tp_session *ps;
573 struct dst_entry *dst;
574
575 session->recv_skb = pppol2tp_recv;
576 session->session_close = pppol2tp_session_close;
577 #if IS_ENABLED(CONFIG_L2TP_DEBUGFS)
578 session->show = pppol2tp_show;
579 #endif
580
581 ps = l2tp_session_priv(session);
582 mutex_init(&ps->sk_lock);
583 ps->owner = current->pid;
584
585 /* If PMTU discovery was enabled, use the MTU that was discovered */
586 dst = sk_dst_get(session->tunnel->sock);
587 if (dst) {
588 u32 pmtu = dst_mtu(dst);
589
590 if (pmtu) {
591 session->mtu = pmtu - PPPOL2TP_HEADER_OVERHEAD;
592 session->mru = pmtu - PPPOL2TP_HEADER_OVERHEAD;
593 }
594 dst_release(dst);
595 }
596 }
597
598 /* connect() handler. Attach a PPPoX socket to a tunnel UDP socket
599 */
600 static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr,
601 int sockaddr_len, int flags)
602 {
603 struct sock *sk = sock->sk;
604 struct sockaddr_pppol2tp *sp = (struct sockaddr_pppol2tp *) uservaddr;
605 struct pppox_sock *po = pppox_sk(sk);
606 struct l2tp_session *session = NULL;
607 struct l2tp_tunnel *tunnel;
608 struct pppol2tp_session *ps;
609 struct l2tp_session_cfg cfg = { 0, };
610 int error = 0;
611 u32 tunnel_id, peer_tunnel_id;
612 u32 session_id, peer_session_id;
613 bool drop_refcnt = false;
614 bool drop_tunnel = false;
615 bool new_session = false;
616 bool new_tunnel = false;
617 int ver = 2;
618 int fd;
619
620 lock_sock(sk);
621
622 error = -EINVAL;
623
624 if (sockaddr_len != sizeof(struct sockaddr_pppol2tp) &&
625 sockaddr_len != sizeof(struct sockaddr_pppol2tpv3) &&
626 sockaddr_len != sizeof(struct sockaddr_pppol2tpin6) &&
627 sockaddr_len != sizeof(struct sockaddr_pppol2tpv3in6))
628 goto end;
629
630 if (sp->sa_protocol != PX_PROTO_OL2TP)
631 goto end;
632
633 /* Check for already bound sockets */
634 error = -EBUSY;
635 if (sk->sk_state & PPPOX_CONNECTED)
636 goto end;
637
638 /* We don't supporting rebinding anyway */
639 error = -EALREADY;
640 if (sk->sk_user_data)
641 goto end; /* socket is already attached */
642
643 /* Get params from socket address. Handle L2TPv2 and L2TPv3.
644 * This is nasty because there are different sockaddr_pppol2tp
645 * structs for L2TPv2, L2TPv3, over IPv4 and IPv6. We use
646 * the sockaddr size to determine which structure the caller
647 * is using.
648 */
649 peer_tunnel_id = 0;
650 if (sockaddr_len == sizeof(struct sockaddr_pppol2tp)) {
651 fd = sp->pppol2tp.fd;
652 tunnel_id = sp->pppol2tp.s_tunnel;
653 peer_tunnel_id = sp->pppol2tp.d_tunnel;
654 session_id = sp->pppol2tp.s_session;
655 peer_session_id = sp->pppol2tp.d_session;
656 } else if (sockaddr_len == sizeof(struct sockaddr_pppol2tpv3)) {
657 struct sockaddr_pppol2tpv3 *sp3 =
658 (struct sockaddr_pppol2tpv3 *) sp;
659 ver = 3;
660 fd = sp3->pppol2tp.fd;
661 tunnel_id = sp3->pppol2tp.s_tunnel;
662 peer_tunnel_id = sp3->pppol2tp.d_tunnel;
663 session_id = sp3->pppol2tp.s_session;
664 peer_session_id = sp3->pppol2tp.d_session;
665 } else if (sockaddr_len == sizeof(struct sockaddr_pppol2tpin6)) {
666 struct sockaddr_pppol2tpin6 *sp6 =
667 (struct sockaddr_pppol2tpin6 *) sp;
668 fd = sp6->pppol2tp.fd;
669 tunnel_id = sp6->pppol2tp.s_tunnel;
670 peer_tunnel_id = sp6->pppol2tp.d_tunnel;
671 session_id = sp6->pppol2tp.s_session;
672 peer_session_id = sp6->pppol2tp.d_session;
673 } else if (sockaddr_len == sizeof(struct sockaddr_pppol2tpv3in6)) {
674 struct sockaddr_pppol2tpv3in6 *sp6 =
675 (struct sockaddr_pppol2tpv3in6 *) sp;
676 ver = 3;
677 fd = sp6->pppol2tp.fd;
678 tunnel_id = sp6->pppol2tp.s_tunnel;
679 peer_tunnel_id = sp6->pppol2tp.d_tunnel;
680 session_id = sp6->pppol2tp.s_session;
681 peer_session_id = sp6->pppol2tp.d_session;
682 } else {
683 error = -EINVAL;
684 goto end; /* bad socket address */
685 }
686
687 /* Don't bind if tunnel_id is 0 */
688 error = -EINVAL;
689 if (tunnel_id == 0)
690 goto end;
691
692 tunnel = l2tp_tunnel_get(sock_net(sk), tunnel_id);
693 if (tunnel)
694 drop_tunnel = true;
695
696 /* Special case: create tunnel context if session_id and
697 * peer_session_id is 0. Otherwise look up tunnel using supplied
698 * tunnel id.
699 */
700 if ((session_id == 0) && (peer_session_id == 0)) {
701 if (tunnel == NULL) {
702 struct l2tp_tunnel_cfg tcfg = {
703 .encap = L2TP_ENCAPTYPE_UDP,
704 .debug = 0,
705 };
706
707 /* Prevent l2tp_tunnel_register() from trying to set up
708 * a kernel socket.
709 */
710 if (fd < 0) {
711 error = -EBADF;
712 goto end;
713 }
714
715 error = l2tp_tunnel_create(sock_net(sk), fd, ver, tunnel_id, peer_tunnel_id, &tcfg, &tunnel);
716 if (error < 0)
717 goto end;
718
719 l2tp_tunnel_inc_refcount(tunnel);
720 error = l2tp_tunnel_register(tunnel, sock_net(sk),
721 &tcfg);
722 if (error < 0) {
723 kfree(tunnel);
724 goto end;
725 }
726 drop_tunnel = true;
727 new_tunnel = true;
728 }
729 } else {
730 /* Error if we can't find the tunnel */
731 error = -ENOENT;
732 if (tunnel == NULL)
733 goto end;
734
735 /* Error if socket is not prepped */
736 if (tunnel->sock == NULL)
737 goto end;
738 }
739
740 if (tunnel->recv_payload_hook == NULL)
741 tunnel->recv_payload_hook = pppol2tp_recv_payload_hook;
742
743 if (tunnel->peer_tunnel_id == 0)
744 tunnel->peer_tunnel_id = peer_tunnel_id;
745
746 session = l2tp_session_get(sock_net(sk), tunnel, session_id);
747 if (session) {
748 drop_refcnt = true;
749
750 if (session->pwtype != L2TP_PWTYPE_PPP) {
751 error = -EPROTOTYPE;
752 goto end;
753 }
754
755 ps = l2tp_session_priv(session);
756
757 /* Using a pre-existing session is fine as long as it hasn't
758 * been connected yet.
759 */
760 mutex_lock(&ps->sk_lock);
761 if (rcu_dereference_protected(ps->sk,
762 lockdep_is_held(&ps->sk_lock)) ||
763 ps->__sk) {
764 mutex_unlock(&ps->sk_lock);
765 error = -EEXIST;
766 goto end;
767 }
768 } else {
769 /* Default MTU must allow space for UDP/L2TP/PPP headers */
770 cfg.mtu = 1500 - PPPOL2TP_HEADER_OVERHEAD;
771 cfg.mru = cfg.mtu;
772 cfg.pw_type = L2TP_PWTYPE_PPP;
773
774 session = l2tp_session_create(sizeof(struct pppol2tp_session),
775 tunnel, session_id,
776 peer_session_id, &cfg);
777 if (IS_ERR(session)) {
778 error = PTR_ERR(session);
779 goto end;
780 }
781
782 pppol2tp_session_init(session);
783 ps = l2tp_session_priv(session);
784 l2tp_session_inc_refcount(session);
785
786 mutex_lock(&ps->sk_lock);
787 error = l2tp_session_register(session, tunnel);
788 if (error < 0) {
789 mutex_unlock(&ps->sk_lock);
790 kfree(session);
791 goto end;
792 }
793 drop_refcnt = true;
794 new_session = true;
795 }
796
797 /* Special case: if source & dest session_id == 0x0000, this
798 * socket is being created to manage the tunnel. Just set up
799 * the internal context for use by ioctl() and sockopt()
800 * handlers.
801 */
802 if ((session->session_id == 0) &&
803 (session->peer_session_id == 0)) {
804 error = 0;
805 goto out_no_ppp;
806 }
807
808 /* The only header we need to worry about is the L2TP
809 * header. This size is different depending on whether
810 * sequence numbers are enabled for the data channel.
811 */
812 po->chan.hdrlen = PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
813
814 po->chan.private = sk;
815 po->chan.ops = &pppol2tp_chan_ops;
816 po->chan.mtu = session->mtu;
817
818 error = ppp_register_net_channel(sock_net(sk), &po->chan);
819 if (error) {
820 mutex_unlock(&ps->sk_lock);
821 goto end;
822 }
823
824 out_no_ppp:
825 /* This is how we get the session context from the socket. */
826 sk->sk_user_data = session;
827 rcu_assign_pointer(ps->sk, sk);
828 mutex_unlock(&ps->sk_lock);
829
830 /* Keep the reference we've grabbed on the session: sk doesn't expect
831 * the session to disappear. pppol2tp_session_destruct() is responsible
832 * for dropping it.
833 */
834 drop_refcnt = false;
835
836 sk->sk_state = PPPOX_CONNECTED;
837 l2tp_info(session, L2TP_MSG_CONTROL, "%s: created\n",
838 session->name);
839
840 end:
841 if (error) {
842 if (new_session)
843 l2tp_session_delete(session);
844 if (new_tunnel)
845 l2tp_tunnel_delete(tunnel);
846 }
847 if (drop_refcnt)
848 l2tp_session_dec_refcount(session);
849 if (drop_tunnel)
850 l2tp_tunnel_dec_refcount(tunnel);
851 release_sock(sk);
852
853 return error;
854 }
855
856 #ifdef CONFIG_L2TP_V3
857
858 /* Called when creating sessions via the netlink interface. */
859 static int pppol2tp_session_create(struct net *net, struct l2tp_tunnel *tunnel,
860 u32 session_id, u32 peer_session_id,
861 struct l2tp_session_cfg *cfg)
862 {
863 int error;
864 struct l2tp_session *session;
865
866 /* Error if tunnel socket is not prepped */
867 if (!tunnel->sock) {
868 error = -ENOENT;
869 goto err;
870 }
871
872 /* Default MTU values. */
873 if (cfg->mtu == 0)
874 cfg->mtu = 1500 - PPPOL2TP_HEADER_OVERHEAD;
875 if (cfg->mru == 0)
876 cfg->mru = cfg->mtu;
877
878 /* Allocate and initialize a new session context. */
879 session = l2tp_session_create(sizeof(struct pppol2tp_session),
880 tunnel, session_id,
881 peer_session_id, cfg);
882 if (IS_ERR(session)) {
883 error = PTR_ERR(session);
884 goto err;
885 }
886
887 pppol2tp_session_init(session);
888
889 error = l2tp_session_register(session, tunnel);
890 if (error < 0)
891 goto err_sess;
892
893 return 0;
894
895 err_sess:
896 kfree(session);
897 err:
898 return error;
899 }
900
901 #endif /* CONFIG_L2TP_V3 */
902
903 /* getname() support.
904 */
905 static int pppol2tp_getname(struct socket *sock, struct sockaddr *uaddr,
906 int peer)
907 {
908 int len = 0;
909 int error = 0;
910 struct l2tp_session *session;
911 struct l2tp_tunnel *tunnel;
912 struct sock *sk = sock->sk;
913 struct inet_sock *inet;
914 struct pppol2tp_session *pls;
915
916 error = -ENOTCONN;
917 if (sk == NULL)
918 goto end;
919 if (!(sk->sk_state & PPPOX_CONNECTED))
920 goto end;
921
922 error = -EBADF;
923 session = pppol2tp_sock_to_session(sk);
924 if (session == NULL)
925 goto end;
926
927 pls = l2tp_session_priv(session);
928 tunnel = session->tunnel;
929
930 inet = inet_sk(tunnel->sock);
931 if ((tunnel->version == 2) && (tunnel->sock->sk_family == AF_INET)) {
932 struct sockaddr_pppol2tp sp;
933 len = sizeof(sp);
934 memset(&sp, 0, len);
935 sp.sa_family = AF_PPPOX;
936 sp.sa_protocol = PX_PROTO_OL2TP;
937 sp.pppol2tp.fd = tunnel->fd;
938 sp.pppol2tp.pid = pls->owner;
939 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
940 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
941 sp.pppol2tp.s_session = session->session_id;
942 sp.pppol2tp.d_session = session->peer_session_id;
943 sp.pppol2tp.addr.sin_family = AF_INET;
944 sp.pppol2tp.addr.sin_port = inet->inet_dport;
945 sp.pppol2tp.addr.sin_addr.s_addr = inet->inet_daddr;
946 memcpy(uaddr, &sp, len);
947 #if IS_ENABLED(CONFIG_IPV6)
948 } else if ((tunnel->version == 2) &&
949 (tunnel->sock->sk_family == AF_INET6)) {
950 struct sockaddr_pppol2tpin6 sp;
951
952 len = sizeof(sp);
953 memset(&sp, 0, len);
954 sp.sa_family = AF_PPPOX;
955 sp.sa_protocol = PX_PROTO_OL2TP;
956 sp.pppol2tp.fd = tunnel->fd;
957 sp.pppol2tp.pid = pls->owner;
958 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
959 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
960 sp.pppol2tp.s_session = session->session_id;
961 sp.pppol2tp.d_session = session->peer_session_id;
962 sp.pppol2tp.addr.sin6_family = AF_INET6;
963 sp.pppol2tp.addr.sin6_port = inet->inet_dport;
964 memcpy(&sp.pppol2tp.addr.sin6_addr, &tunnel->sock->sk_v6_daddr,
965 sizeof(tunnel->sock->sk_v6_daddr));
966 memcpy(uaddr, &sp, len);
967 } else if ((tunnel->version == 3) &&
968 (tunnel->sock->sk_family == AF_INET6)) {
969 struct sockaddr_pppol2tpv3in6 sp;
970
971 len = sizeof(sp);
972 memset(&sp, 0, len);
973 sp.sa_family = AF_PPPOX;
974 sp.sa_protocol = PX_PROTO_OL2TP;
975 sp.pppol2tp.fd = tunnel->fd;
976 sp.pppol2tp.pid = pls->owner;
977 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
978 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
979 sp.pppol2tp.s_session = session->session_id;
980 sp.pppol2tp.d_session = session->peer_session_id;
981 sp.pppol2tp.addr.sin6_family = AF_INET6;
982 sp.pppol2tp.addr.sin6_port = inet->inet_dport;
983 memcpy(&sp.pppol2tp.addr.sin6_addr, &tunnel->sock->sk_v6_daddr,
984 sizeof(tunnel->sock->sk_v6_daddr));
985 memcpy(uaddr, &sp, len);
986 #endif
987 } else if (tunnel->version == 3) {
988 struct sockaddr_pppol2tpv3 sp;
989 len = sizeof(sp);
990 memset(&sp, 0, len);
991 sp.sa_family = AF_PPPOX;
992 sp.sa_protocol = PX_PROTO_OL2TP;
993 sp.pppol2tp.fd = tunnel->fd;
994 sp.pppol2tp.pid = pls->owner;
995 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
996 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
997 sp.pppol2tp.s_session = session->session_id;
998 sp.pppol2tp.d_session = session->peer_session_id;
999 sp.pppol2tp.addr.sin_family = AF_INET;
1000 sp.pppol2tp.addr.sin_port = inet->inet_dport;
1001 sp.pppol2tp.addr.sin_addr.s_addr = inet->inet_daddr;
1002 memcpy(uaddr, &sp, len);
1003 }
1004
1005 error = len;
1006
1007 sock_put(sk);
1008 end:
1009 return error;
1010 }
1011
1012 /****************************************************************************
1013 * ioctl() handlers.
1014 *
1015 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
1016 * sockets. However, in order to control kernel tunnel features, we allow
1017 * userspace to create a special "tunnel" PPPoX socket which is used for
1018 * control only. Tunnel PPPoX sockets have session_id == 0 and simply allow
1019 * the user application to issue L2TP setsockopt(), getsockopt() and ioctl()
1020 * calls.
1021 ****************************************************************************/
1022
1023 static void pppol2tp_copy_stats(struct pppol2tp_ioc_stats *dest,
1024 struct l2tp_stats *stats)
1025 {
1026 dest->tx_packets = atomic_long_read(&stats->tx_packets);
1027 dest->tx_bytes = atomic_long_read(&stats->tx_bytes);
1028 dest->tx_errors = atomic_long_read(&stats->tx_errors);
1029 dest->rx_packets = atomic_long_read(&stats->rx_packets);
1030 dest->rx_bytes = atomic_long_read(&stats->rx_bytes);
1031 dest->rx_seq_discards = atomic_long_read(&stats->rx_seq_discards);
1032 dest->rx_oos_packets = atomic_long_read(&stats->rx_oos_packets);
1033 dest->rx_errors = atomic_long_read(&stats->rx_errors);
1034 }
1035
1036 /* Session ioctl helper.
1037 */
1038 static int pppol2tp_session_ioctl(struct l2tp_session *session,
1039 unsigned int cmd, unsigned long arg)
1040 {
1041 struct ifreq ifr;
1042 int err = 0;
1043 struct sock *sk;
1044 int val = (int) arg;
1045 struct pppol2tp_session *ps = l2tp_session_priv(session);
1046 struct l2tp_tunnel *tunnel = session->tunnel;
1047 struct pppol2tp_ioc_stats stats;
1048
1049 l2tp_dbg(session, L2TP_MSG_CONTROL,
1050 "%s: pppol2tp_session_ioctl(cmd=%#x, arg=%#lx)\n",
1051 session->name, cmd, arg);
1052
1053 sk = pppol2tp_session_get_sock(session);
1054 if (!sk)
1055 return -EBADR;
1056
1057 switch (cmd) {
1058 case SIOCGIFMTU:
1059 err = -ENXIO;
1060 if (!(sk->sk_state & PPPOX_CONNECTED))
1061 break;
1062
1063 err = -EFAULT;
1064 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq)))
1065 break;
1066 ifr.ifr_mtu = session->mtu;
1067 if (copy_to_user((void __user *) arg, &ifr, sizeof(struct ifreq)))
1068 break;
1069
1070 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get mtu=%d\n",
1071 session->name, session->mtu);
1072 err = 0;
1073 break;
1074
1075 case SIOCSIFMTU:
1076 err = -ENXIO;
1077 if (!(sk->sk_state & PPPOX_CONNECTED))
1078 break;
1079
1080 err = -EFAULT;
1081 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq)))
1082 break;
1083
1084 session->mtu = ifr.ifr_mtu;
1085
1086 l2tp_info(session, L2TP_MSG_CONTROL, "%s: set mtu=%d\n",
1087 session->name, session->mtu);
1088 err = 0;
1089 break;
1090
1091 case PPPIOCGMRU:
1092 err = -ENXIO;
1093 if (!(sk->sk_state & PPPOX_CONNECTED))
1094 break;
1095
1096 err = -EFAULT;
1097 if (put_user(session->mru, (int __user *) arg))
1098 break;
1099
1100 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get mru=%d\n",
1101 session->name, session->mru);
1102 err = 0;
1103 break;
1104
1105 case PPPIOCSMRU:
1106 err = -ENXIO;
1107 if (!(sk->sk_state & PPPOX_CONNECTED))
1108 break;
1109
1110 err = -EFAULT;
1111 if (get_user(val, (int __user *) arg))
1112 break;
1113
1114 session->mru = val;
1115 l2tp_info(session, L2TP_MSG_CONTROL, "%s: set mru=%d\n",
1116 session->name, session->mru);
1117 err = 0;
1118 break;
1119
1120 case PPPIOCGFLAGS:
1121 err = -EFAULT;
1122 if (put_user(ps->flags, (int __user *) arg))
1123 break;
1124
1125 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get flags=%d\n",
1126 session->name, ps->flags);
1127 err = 0;
1128 break;
1129
1130 case PPPIOCSFLAGS:
1131 err = -EFAULT;
1132 if (get_user(val, (int __user *) arg))
1133 break;
1134 ps->flags = val;
1135 l2tp_info(session, L2TP_MSG_CONTROL, "%s: set flags=%d\n",
1136 session->name, ps->flags);
1137 err = 0;
1138 break;
1139
1140 case PPPIOCGL2TPSTATS:
1141 err = -ENXIO;
1142 if (!(sk->sk_state & PPPOX_CONNECTED))
1143 break;
1144
1145 memset(&stats, 0, sizeof(stats));
1146 stats.tunnel_id = tunnel->tunnel_id;
1147 stats.session_id = session->session_id;
1148 pppol2tp_copy_stats(&stats, &session->stats);
1149 if (copy_to_user((void __user *) arg, &stats,
1150 sizeof(stats)))
1151 break;
1152 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get L2TP stats\n",
1153 session->name);
1154 err = 0;
1155 break;
1156
1157 default:
1158 err = -ENOSYS;
1159 break;
1160 }
1161
1162 sock_put(sk);
1163
1164 return err;
1165 }
1166
1167 /* Tunnel ioctl helper.
1168 *
1169 * Note the special handling for PPPIOCGL2TPSTATS below. If the ioctl data
1170 * specifies a session_id, the session ioctl handler is called. This allows an
1171 * application to retrieve session stats via a tunnel socket.
1172 */
1173 static int pppol2tp_tunnel_ioctl(struct l2tp_tunnel *tunnel,
1174 unsigned int cmd, unsigned long arg)
1175 {
1176 int err = 0;
1177 struct sock *sk;
1178 struct pppol2tp_ioc_stats stats;
1179
1180 l2tp_dbg(tunnel, L2TP_MSG_CONTROL,
1181 "%s: pppol2tp_tunnel_ioctl(cmd=%#x, arg=%#lx)\n",
1182 tunnel->name, cmd, arg);
1183
1184 sk = tunnel->sock;
1185 sock_hold(sk);
1186
1187 switch (cmd) {
1188 case PPPIOCGL2TPSTATS:
1189 err = -ENXIO;
1190 if (!(sk->sk_state & PPPOX_CONNECTED))
1191 break;
1192
1193 if (copy_from_user(&stats, (void __user *) arg,
1194 sizeof(stats))) {
1195 err = -EFAULT;
1196 break;
1197 }
1198 if (stats.session_id != 0) {
1199 /* resend to session ioctl handler */
1200 struct l2tp_session *session =
1201 l2tp_session_get(sock_net(sk), tunnel,
1202 stats.session_id);
1203
1204 if (session && session->pwtype == L2TP_PWTYPE_PPP) {
1205 err = pppol2tp_session_ioctl(session, cmd,
1206 arg);
1207 l2tp_session_dec_refcount(session);
1208 } else {
1209 err = -EBADR;
1210 }
1211 break;
1212 }
1213 #ifdef CONFIG_XFRM
1214 stats.using_ipsec = (sk->sk_policy[0] || sk->sk_policy[1]) ? 1 : 0;
1215 #endif
1216 pppol2tp_copy_stats(&stats, &tunnel->stats);
1217 if (copy_to_user((void __user *) arg, &stats, sizeof(stats))) {
1218 err = -EFAULT;
1219 break;
1220 }
1221 l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: get L2TP stats\n",
1222 tunnel->name);
1223 err = 0;
1224 break;
1225
1226 default:
1227 err = -ENOSYS;
1228 break;
1229 }
1230
1231 sock_put(sk);
1232
1233 return err;
1234 }
1235
1236 /* Main ioctl() handler.
1237 * Dispatch to tunnel or session helpers depending on the socket.
1238 */
1239 static int pppol2tp_ioctl(struct socket *sock, unsigned int cmd,
1240 unsigned long arg)
1241 {
1242 struct sock *sk = sock->sk;
1243 struct l2tp_session *session;
1244 struct l2tp_tunnel *tunnel;
1245 int err;
1246
1247 if (!sk)
1248 return 0;
1249
1250 err = -EBADF;
1251 if (sock_flag(sk, SOCK_DEAD) != 0)
1252 goto end;
1253
1254 err = -ENOTCONN;
1255 if ((sk->sk_user_data == NULL) ||
1256 (!(sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND))))
1257 goto end;
1258
1259 /* Get session context from the socket */
1260 err = -EBADF;
1261 session = pppol2tp_sock_to_session(sk);
1262 if (session == NULL)
1263 goto end;
1264
1265 /* Special case: if session's session_id is zero, treat ioctl as a
1266 * tunnel ioctl
1267 */
1268 if ((session->session_id == 0) &&
1269 (session->peer_session_id == 0)) {
1270 tunnel = session->tunnel;
1271 err = pppol2tp_tunnel_ioctl(tunnel, cmd, arg);
1272 goto end_put_sess;
1273 }
1274
1275 err = pppol2tp_session_ioctl(session, cmd, arg);
1276
1277 end_put_sess:
1278 sock_put(sk);
1279 end:
1280 return err;
1281 }
1282
1283 /*****************************************************************************
1284 * setsockopt() / getsockopt() support.
1285 *
1286 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
1287 * sockets. In order to control kernel tunnel features, we allow userspace to
1288 * create a special "tunnel" PPPoX socket which is used for control only.
1289 * Tunnel PPPoX sockets have session_id == 0 and simply allow the user
1290 * application to issue L2TP setsockopt(), getsockopt() and ioctl() calls.
1291 *****************************************************************************/
1292
1293 /* Tunnel setsockopt() helper.
1294 */
1295 static int pppol2tp_tunnel_setsockopt(struct sock *sk,
1296 struct l2tp_tunnel *tunnel,
1297 int optname, int val)
1298 {
1299 int err = 0;
1300
1301 switch (optname) {
1302 case PPPOL2TP_SO_DEBUG:
1303 tunnel->debug = val;
1304 l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: set debug=%x\n",
1305 tunnel->name, tunnel->debug);
1306 break;
1307
1308 default:
1309 err = -ENOPROTOOPT;
1310 break;
1311 }
1312
1313 return err;
1314 }
1315
1316 /* Session setsockopt helper.
1317 */
1318 static int pppol2tp_session_setsockopt(struct sock *sk,
1319 struct l2tp_session *session,
1320 int optname, int val)
1321 {
1322 int err = 0;
1323
1324 switch (optname) {
1325 case PPPOL2TP_SO_RECVSEQ:
1326 if ((val != 0) && (val != 1)) {
1327 err = -EINVAL;
1328 break;
1329 }
1330 session->recv_seq = !!val;
1331 l2tp_info(session, L2TP_MSG_CONTROL,
1332 "%s: set recv_seq=%d\n",
1333 session->name, session->recv_seq);
1334 break;
1335
1336 case PPPOL2TP_SO_SENDSEQ:
1337 if ((val != 0) && (val != 1)) {
1338 err = -EINVAL;
1339 break;
1340 }
1341 session->send_seq = !!val;
1342 {
1343 struct pppox_sock *po = pppox_sk(sk);
1344
1345 po->chan.hdrlen = val ? PPPOL2TP_L2TP_HDR_SIZE_SEQ :
1346 PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
1347 }
1348 l2tp_session_set_header_len(session, session->tunnel->version);
1349 l2tp_info(session, L2TP_MSG_CONTROL,
1350 "%s: set send_seq=%d\n",
1351 session->name, session->send_seq);
1352 break;
1353
1354 case PPPOL2TP_SO_LNSMODE:
1355 if ((val != 0) && (val != 1)) {
1356 err = -EINVAL;
1357 break;
1358 }
1359 session->lns_mode = !!val;
1360 l2tp_info(session, L2TP_MSG_CONTROL,
1361 "%s: set lns_mode=%d\n",
1362 session->name, session->lns_mode);
1363 break;
1364
1365 case PPPOL2TP_SO_DEBUG:
1366 session->debug = val;
1367 l2tp_info(session, L2TP_MSG_CONTROL, "%s: set debug=%x\n",
1368 session->name, session->debug);
1369 break;
1370
1371 case PPPOL2TP_SO_REORDERTO:
1372 session->reorder_timeout = msecs_to_jiffies(val);
1373 l2tp_info(session, L2TP_MSG_CONTROL,
1374 "%s: set reorder_timeout=%d\n",
1375 session->name, session->reorder_timeout);
1376 break;
1377
1378 default:
1379 err = -ENOPROTOOPT;
1380 break;
1381 }
1382
1383 return err;
1384 }
1385
1386 /* Main setsockopt() entry point.
1387 * Does API checks, then calls either the tunnel or session setsockopt
1388 * handler, according to whether the PPPoL2TP socket is a for a regular
1389 * session or the special tunnel type.
1390 */
1391 static int pppol2tp_setsockopt(struct socket *sock, int level, int optname,
1392 char __user *optval, unsigned int optlen)
1393 {
1394 struct sock *sk = sock->sk;
1395 struct l2tp_session *session;
1396 struct l2tp_tunnel *tunnel;
1397 int val;
1398 int err;
1399
1400 if (level != SOL_PPPOL2TP)
1401 return -EINVAL;
1402
1403 if (optlen < sizeof(int))
1404 return -EINVAL;
1405
1406 if (get_user(val, (int __user *)optval))
1407 return -EFAULT;
1408
1409 err = -ENOTCONN;
1410 if (sk->sk_user_data == NULL)
1411 goto end;
1412
1413 /* Get session context from the socket */
1414 err = -EBADF;
1415 session = pppol2tp_sock_to_session(sk);
1416 if (session == NULL)
1417 goto end;
1418
1419 /* Special case: if session_id == 0x0000, treat as operation on tunnel
1420 */
1421 if ((session->session_id == 0) &&
1422 (session->peer_session_id == 0)) {
1423 tunnel = session->tunnel;
1424 err = pppol2tp_tunnel_setsockopt(sk, tunnel, optname, val);
1425 } else {
1426 err = pppol2tp_session_setsockopt(sk, session, optname, val);
1427 }
1428
1429 sock_put(sk);
1430 end:
1431 return err;
1432 }
1433
1434 /* Tunnel getsockopt helper. Called with sock locked.
1435 */
1436 static int pppol2tp_tunnel_getsockopt(struct sock *sk,
1437 struct l2tp_tunnel *tunnel,
1438 int optname, int *val)
1439 {
1440 int err = 0;
1441
1442 switch (optname) {
1443 case PPPOL2TP_SO_DEBUG:
1444 *val = tunnel->debug;
1445 l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: get debug=%x\n",
1446 tunnel->name, tunnel->debug);
1447 break;
1448
1449 default:
1450 err = -ENOPROTOOPT;
1451 break;
1452 }
1453
1454 return err;
1455 }
1456
1457 /* Session getsockopt helper. Called with sock locked.
1458 */
1459 static int pppol2tp_session_getsockopt(struct sock *sk,
1460 struct l2tp_session *session,
1461 int optname, int *val)
1462 {
1463 int err = 0;
1464
1465 switch (optname) {
1466 case PPPOL2TP_SO_RECVSEQ:
1467 *val = session->recv_seq;
1468 l2tp_info(session, L2TP_MSG_CONTROL,
1469 "%s: get recv_seq=%d\n", session->name, *val);
1470 break;
1471
1472 case PPPOL2TP_SO_SENDSEQ:
1473 *val = session->send_seq;
1474 l2tp_info(session, L2TP_MSG_CONTROL,
1475 "%s: get send_seq=%d\n", session->name, *val);
1476 break;
1477
1478 case PPPOL2TP_SO_LNSMODE:
1479 *val = session->lns_mode;
1480 l2tp_info(session, L2TP_MSG_CONTROL,
1481 "%s: get lns_mode=%d\n", session->name, *val);
1482 break;
1483
1484 case PPPOL2TP_SO_DEBUG:
1485 *val = session->debug;
1486 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get debug=%d\n",
1487 session->name, *val);
1488 break;
1489
1490 case PPPOL2TP_SO_REORDERTO:
1491 *val = (int) jiffies_to_msecs(session->reorder_timeout);
1492 l2tp_info(session, L2TP_MSG_CONTROL,
1493 "%s: get reorder_timeout=%d\n", session->name, *val);
1494 break;
1495
1496 default:
1497 err = -ENOPROTOOPT;
1498 }
1499
1500 return err;
1501 }
1502
1503 /* Main getsockopt() entry point.
1504 * Does API checks, then calls either the tunnel or session getsockopt
1505 * handler, according to whether the PPPoX socket is a for a regular session
1506 * or the special tunnel type.
1507 */
1508 static int pppol2tp_getsockopt(struct socket *sock, int level, int optname,
1509 char __user *optval, int __user *optlen)
1510 {
1511 struct sock *sk = sock->sk;
1512 struct l2tp_session *session;
1513 struct l2tp_tunnel *tunnel;
1514 int val, len;
1515 int err;
1516
1517 if (level != SOL_PPPOL2TP)
1518 return -EINVAL;
1519
1520 if (get_user(len, optlen))
1521 return -EFAULT;
1522
1523 len = min_t(unsigned int, len, sizeof(int));
1524
1525 if (len < 0)
1526 return -EINVAL;
1527
1528 err = -ENOTCONN;
1529 if (sk->sk_user_data == NULL)
1530 goto end;
1531
1532 /* Get the session context */
1533 err = -EBADF;
1534 session = pppol2tp_sock_to_session(sk);
1535 if (session == NULL)
1536 goto end;
1537
1538 /* Special case: if session_id == 0x0000, treat as operation on tunnel */
1539 if ((session->session_id == 0) &&
1540 (session->peer_session_id == 0)) {
1541 tunnel = session->tunnel;
1542 err = pppol2tp_tunnel_getsockopt(sk, tunnel, optname, &val);
1543 if (err)
1544 goto end_put_sess;
1545 } else {
1546 err = pppol2tp_session_getsockopt(sk, session, optname, &val);
1547 if (err)
1548 goto end_put_sess;
1549 }
1550
1551 err = -EFAULT;
1552 if (put_user(len, optlen))
1553 goto end_put_sess;
1554
1555 if (copy_to_user((void __user *) optval, &val, len))
1556 goto end_put_sess;
1557
1558 err = 0;
1559
1560 end_put_sess:
1561 sock_put(sk);
1562 end:
1563 return err;
1564 }
1565
1566 /*****************************************************************************
1567 * /proc filesystem for debug
1568 * Since the original pppol2tp driver provided /proc/net/pppol2tp for
1569 * L2TPv2, we dump only L2TPv2 tunnels and sessions here.
1570 *****************************************************************************/
1571
1572 static unsigned int pppol2tp_net_id;
1573
1574 #ifdef CONFIG_PROC_FS
1575
1576 struct pppol2tp_seq_data {
1577 struct seq_net_private p;
1578 int tunnel_idx; /* current tunnel */
1579 int session_idx; /* index of session within current tunnel */
1580 struct l2tp_tunnel *tunnel;
1581 struct l2tp_session *session; /* NULL means get next tunnel */
1582 };
1583
1584 static void pppol2tp_next_tunnel(struct net *net, struct pppol2tp_seq_data *pd)
1585 {
1586 /* Drop reference taken during previous invocation */
1587 if (pd->tunnel)
1588 l2tp_tunnel_dec_refcount(pd->tunnel);
1589
1590 for (;;) {
1591 pd->tunnel = l2tp_tunnel_get_nth(net, pd->tunnel_idx);
1592 pd->tunnel_idx++;
1593
1594 /* Only accept L2TPv2 tunnels */
1595 if (!pd->tunnel || pd->tunnel->version == 2)
1596 return;
1597
1598 l2tp_tunnel_dec_refcount(pd->tunnel);
1599 }
1600 }
1601
1602 static void pppol2tp_next_session(struct net *net, struct pppol2tp_seq_data *pd)
1603 {
1604 /* Drop reference taken during previous invocation */
1605 if (pd->session)
1606 l2tp_session_dec_refcount(pd->session);
1607
1608 pd->session = l2tp_session_get_nth(pd->tunnel, pd->session_idx);
1609 pd->session_idx++;
1610
1611 if (pd->session == NULL) {
1612 pd->session_idx = 0;
1613 pppol2tp_next_tunnel(net, pd);
1614 }
1615 }
1616
1617 static void *pppol2tp_seq_start(struct seq_file *m, loff_t *offs)
1618 {
1619 struct pppol2tp_seq_data *pd = SEQ_START_TOKEN;
1620 loff_t pos = *offs;
1621 struct net *net;
1622
1623 if (!pos)
1624 goto out;
1625
1626 BUG_ON(m->private == NULL);
1627 pd = m->private;
1628 net = seq_file_net(m);
1629
1630 if (pd->tunnel == NULL)
1631 pppol2tp_next_tunnel(net, pd);
1632 else
1633 pppol2tp_next_session(net, pd);
1634
1635 /* NULL tunnel and session indicates end of list */
1636 if ((pd->tunnel == NULL) && (pd->session == NULL))
1637 pd = NULL;
1638
1639 out:
1640 return pd;
1641 }
1642
1643 static void *pppol2tp_seq_next(struct seq_file *m, void *v, loff_t *pos)
1644 {
1645 (*pos)++;
1646 return NULL;
1647 }
1648
1649 static void pppol2tp_seq_stop(struct seq_file *p, void *v)
1650 {
1651 struct pppol2tp_seq_data *pd = v;
1652
1653 if (!pd || pd == SEQ_START_TOKEN)
1654 return;
1655
1656 /* Drop reference taken by last invocation of pppol2tp_next_session()
1657 * or pppol2tp_next_tunnel().
1658 */
1659 if (pd->session) {
1660 l2tp_session_dec_refcount(pd->session);
1661 pd->session = NULL;
1662 }
1663 if (pd->tunnel) {
1664 l2tp_tunnel_dec_refcount(pd->tunnel);
1665 pd->tunnel = NULL;
1666 }
1667 }
1668
1669 static void pppol2tp_seq_tunnel_show(struct seq_file *m, void *v)
1670 {
1671 struct l2tp_tunnel *tunnel = v;
1672
1673 seq_printf(m, "\nTUNNEL '%s', %c %d\n",
1674 tunnel->name,
1675 (tunnel == tunnel->sock->sk_user_data) ? 'Y' : 'N',
1676 refcount_read(&tunnel->ref_count) - 1);
1677 seq_printf(m, " %08x %ld/%ld/%ld %ld/%ld/%ld\n",
1678 tunnel->debug,
1679 atomic_long_read(&tunnel->stats.tx_packets),
1680 atomic_long_read(&tunnel->stats.tx_bytes),
1681 atomic_long_read(&tunnel->stats.tx_errors),
1682 atomic_long_read(&tunnel->stats.rx_packets),
1683 atomic_long_read(&tunnel->stats.rx_bytes),
1684 atomic_long_read(&tunnel->stats.rx_errors));
1685 }
1686
1687 static void pppol2tp_seq_session_show(struct seq_file *m, void *v)
1688 {
1689 struct l2tp_session *session = v;
1690 struct l2tp_tunnel *tunnel = session->tunnel;
1691 unsigned char state;
1692 char user_data_ok;
1693 struct sock *sk;
1694 u32 ip = 0;
1695 u16 port = 0;
1696
1697 if (tunnel->sock) {
1698 struct inet_sock *inet = inet_sk(tunnel->sock);
1699 ip = ntohl(inet->inet_saddr);
1700 port = ntohs(inet->inet_sport);
1701 }
1702
1703 sk = pppol2tp_session_get_sock(session);
1704 if (sk) {
1705 state = sk->sk_state;
1706 user_data_ok = (session == sk->sk_user_data) ? 'Y' : 'N';
1707 } else {
1708 state = 0;
1709 user_data_ok = 'N';
1710 }
1711
1712 seq_printf(m, " SESSION '%s' %08X/%d %04X/%04X -> "
1713 "%04X/%04X %d %c\n",
1714 session->name, ip, port,
1715 tunnel->tunnel_id,
1716 session->session_id,
1717 tunnel->peer_tunnel_id,
1718 session->peer_session_id,
1719 state, user_data_ok);
1720 seq_printf(m, " %d/%d/%c/%c/%s %08x %u\n",
1721 session->mtu, session->mru,
1722 session->recv_seq ? 'R' : '-',
1723 session->send_seq ? 'S' : '-',
1724 session->lns_mode ? "LNS" : "LAC",
1725 session->debug,
1726 jiffies_to_msecs(session->reorder_timeout));
1727 seq_printf(m, " %hu/%hu %ld/%ld/%ld %ld/%ld/%ld\n",
1728 session->nr, session->ns,
1729 atomic_long_read(&session->stats.tx_packets),
1730 atomic_long_read(&session->stats.tx_bytes),
1731 atomic_long_read(&session->stats.tx_errors),
1732 atomic_long_read(&session->stats.rx_packets),
1733 atomic_long_read(&session->stats.rx_bytes),
1734 atomic_long_read(&session->stats.rx_errors));
1735
1736 if (sk) {
1737 struct pppox_sock *po = pppox_sk(sk);
1738
1739 seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan));
1740 sock_put(sk);
1741 }
1742 }
1743
1744 static int pppol2tp_seq_show(struct seq_file *m, void *v)
1745 {
1746 struct pppol2tp_seq_data *pd = v;
1747
1748 /* display header on line 1 */
1749 if (v == SEQ_START_TOKEN) {
1750 seq_puts(m, "PPPoL2TP driver info, " PPPOL2TP_DRV_VERSION "\n");
1751 seq_puts(m, "TUNNEL name, user-data-ok session-count\n");
1752 seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
1753 seq_puts(m, " SESSION name, addr/port src-tid/sid "
1754 "dest-tid/sid state user-data-ok\n");
1755 seq_puts(m, " mtu/mru/rcvseq/sendseq/lns debug reorderto\n");
1756 seq_puts(m, " nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
1757 goto out;
1758 }
1759
1760 if (!pd->session)
1761 pppol2tp_seq_tunnel_show(m, pd->tunnel);
1762 else
1763 pppol2tp_seq_session_show(m, pd->session);
1764
1765 out:
1766 return 0;
1767 }
1768
1769 static const struct seq_operations pppol2tp_seq_ops = {
1770 .start = pppol2tp_seq_start,
1771 .next = pppol2tp_seq_next,
1772 .stop = pppol2tp_seq_stop,
1773 .show = pppol2tp_seq_show,
1774 };
1775 #endif /* CONFIG_PROC_FS */
1776
1777 /*****************************************************************************
1778 * Network namespace
1779 *****************************************************************************/
1780
1781 static __net_init int pppol2tp_init_net(struct net *net)
1782 {
1783 struct proc_dir_entry *pde;
1784 int err = 0;
1785
1786 pde = proc_create_net("pppol2tp", 0444, net->proc_net,
1787 &pppol2tp_seq_ops, sizeof(struct pppol2tp_seq_data));
1788 if (!pde) {
1789 err = -ENOMEM;
1790 goto out;
1791 }
1792
1793 out:
1794 return err;
1795 }
1796
1797 static __net_exit void pppol2tp_exit_net(struct net *net)
1798 {
1799 remove_proc_entry("pppol2tp", net->proc_net);
1800 }
1801
1802 static struct pernet_operations pppol2tp_net_ops = {
1803 .init = pppol2tp_init_net,
1804 .exit = pppol2tp_exit_net,
1805 .id = &pppol2tp_net_id,
1806 };
1807
1808 /*****************************************************************************
1809 * Init and cleanup
1810 *****************************************************************************/
1811
1812 static const struct proto_ops pppol2tp_ops = {
1813 .family = AF_PPPOX,
1814 .owner = THIS_MODULE,
1815 .release = pppol2tp_release,
1816 .bind = sock_no_bind,
1817 .connect = pppol2tp_connect,
1818 .socketpair = sock_no_socketpair,
1819 .accept = sock_no_accept,
1820 .getname = pppol2tp_getname,
1821 .poll_mask = datagram_poll_mask,
1822 .listen = sock_no_listen,
1823 .shutdown = sock_no_shutdown,
1824 .setsockopt = pppol2tp_setsockopt,
1825 .getsockopt = pppol2tp_getsockopt,
1826 .sendmsg = pppol2tp_sendmsg,
1827 .recvmsg = pppol2tp_recvmsg,
1828 .mmap = sock_no_mmap,
1829 .ioctl = pppox_ioctl,
1830 };
1831
1832 static const struct pppox_proto pppol2tp_proto = {
1833 .create = pppol2tp_create,
1834 .ioctl = pppol2tp_ioctl,
1835 .owner = THIS_MODULE,
1836 };
1837
1838 #ifdef CONFIG_L2TP_V3
1839
1840 static const struct l2tp_nl_cmd_ops pppol2tp_nl_cmd_ops = {
1841 .session_create = pppol2tp_session_create,
1842 .session_delete = l2tp_session_delete,
1843 };
1844
1845 #endif /* CONFIG_L2TP_V3 */
1846
1847 static int __init pppol2tp_init(void)
1848 {
1849 int err;
1850
1851 err = register_pernet_device(&pppol2tp_net_ops);
1852 if (err)
1853 goto out;
1854
1855 err = proto_register(&pppol2tp_sk_proto, 0);
1856 if (err)
1857 goto out_unregister_pppol2tp_pernet;
1858
1859 err = register_pppox_proto(PX_PROTO_OL2TP, &pppol2tp_proto);
1860 if (err)
1861 goto out_unregister_pppol2tp_proto;
1862
1863 #ifdef CONFIG_L2TP_V3
1864 err = l2tp_nl_register_ops(L2TP_PWTYPE_PPP, &pppol2tp_nl_cmd_ops);
1865 if (err)
1866 goto out_unregister_pppox;
1867 #endif
1868
1869 pr_info("PPPoL2TP kernel driver, %s\n", PPPOL2TP_DRV_VERSION);
1870
1871 out:
1872 return err;
1873
1874 #ifdef CONFIG_L2TP_V3
1875 out_unregister_pppox:
1876 unregister_pppox_proto(PX_PROTO_OL2TP);
1877 #endif
1878 out_unregister_pppol2tp_proto:
1879 proto_unregister(&pppol2tp_sk_proto);
1880 out_unregister_pppol2tp_pernet:
1881 unregister_pernet_device(&pppol2tp_net_ops);
1882 goto out;
1883 }
1884
1885 static void __exit pppol2tp_exit(void)
1886 {
1887 #ifdef CONFIG_L2TP_V3
1888 l2tp_nl_unregister_ops(L2TP_PWTYPE_PPP);
1889 #endif
1890 unregister_pppox_proto(PX_PROTO_OL2TP);
1891 proto_unregister(&pppol2tp_sk_proto);
1892 unregister_pernet_device(&pppol2tp_net_ops);
1893 }
1894
1895 module_init(pppol2tp_init);
1896 module_exit(pppol2tp_exit);
1897
1898 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
1899 MODULE_DESCRIPTION("PPP over L2TP over UDP");
1900 MODULE_LICENSE("GPL");
1901 MODULE_VERSION(PPPOL2TP_DRV_VERSION);
1902 MODULE_ALIAS_NET_PF_PROTO(PF_PPPOX, PX_PROTO_OL2TP);
1903 MODULE_ALIAS_L2TP_PWTYPE(7);
Linux with added FPC-III support