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Merge tag 'mac80211-next-for-davem-2018-03-29' of git://git.kernel.org/pub/scm/linux...
[mirror_ubuntu-eoan-kernel.git] / net / l2tp / l2tp_ppp.c
1 /*****************************************************************************
2 * Linux PPP over L2TP (PPPoX/PPPoL2TP) Sockets
3 *
4 * PPPoX --- Generic PPP encapsulation socket family
5 * PPPoL2TP --- PPP over L2TP (RFC 2661)
6 *
7 * Version: 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 struct pppol2tp_session *ps;
432
433 ps = l2tp_session_priv(session);
434 mutex_lock(&ps->sk_lock);
435 ps->__sk = rcu_dereference_protected(ps->sk,
436 lockdep_is_held(&ps->sk_lock));
437 RCU_INIT_POINTER(ps->sk, NULL);
438 if (ps->__sk)
439 call_rcu(&ps->rcu, pppol2tp_put_sk);
440 mutex_unlock(&ps->sk_lock);
441 }
442
443 /* Really kill the session socket. (Called from sock_put() if
444 * refcnt == 0.)
445 */
446 static void pppol2tp_session_destruct(struct sock *sk)
447 {
448 struct l2tp_session *session = sk->sk_user_data;
449
450 skb_queue_purge(&sk->sk_receive_queue);
451 skb_queue_purge(&sk->sk_write_queue);
452
453 if (session) {
454 sk->sk_user_data = NULL;
455 BUG_ON(session->magic != L2TP_SESSION_MAGIC);
456 l2tp_session_dec_refcount(session);
457 }
458 }
459
460 /* Called when the PPPoX socket (session) is closed.
461 */
462 static int pppol2tp_release(struct socket *sock)
463 {
464 struct sock *sk = sock->sk;
465 struct l2tp_session *session;
466 int error;
467
468 if (!sk)
469 return 0;
470
471 error = -EBADF;
472 lock_sock(sk);
473 if (sock_flag(sk, SOCK_DEAD) != 0)
474 goto error;
475
476 pppox_unbind_sock(sk);
477
478 /* Signal the death of the socket. */
479 sk->sk_state = PPPOX_DEAD;
480 sock_orphan(sk);
481 sock->sk = NULL;
482
483 /* If the socket is associated with a session,
484 * l2tp_session_delete will call pppol2tp_session_close which
485 * will drop the session's ref on the socket.
486 */
487 session = pppol2tp_sock_to_session(sk);
488 if (session) {
489 l2tp_session_delete(session);
490 /* drop the ref obtained by pppol2tp_sock_to_session */
491 sock_put(sk);
492 }
493
494 release_sock(sk);
495
496 /* This will delete the session context via
497 * pppol2tp_session_destruct() if the socket's refcnt drops to
498 * zero.
499 */
500 sock_put(sk);
501
502 return 0;
503
504 error:
505 release_sock(sk);
506 return error;
507 }
508
509 static struct proto pppol2tp_sk_proto = {
510 .name = "PPPOL2TP",
511 .owner = THIS_MODULE,
512 .obj_size = sizeof(struct pppox_sock),
513 };
514
515 static int pppol2tp_backlog_recv(struct sock *sk, struct sk_buff *skb)
516 {
517 int rc;
518
519 rc = l2tp_udp_encap_recv(sk, skb);
520 if (rc)
521 kfree_skb(skb);
522
523 return NET_RX_SUCCESS;
524 }
525
526 /* socket() handler. Initialize a new struct sock.
527 */
528 static int pppol2tp_create(struct net *net, struct socket *sock, int kern)
529 {
530 int error = -ENOMEM;
531 struct sock *sk;
532
533 sk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, &pppol2tp_sk_proto, kern);
534 if (!sk)
535 goto out;
536
537 sock_init_data(sock, sk);
538
539 sock->state = SS_UNCONNECTED;
540 sock->ops = &pppol2tp_ops;
541
542 sk->sk_backlog_rcv = pppol2tp_backlog_recv;
543 sk->sk_protocol = PX_PROTO_OL2TP;
544 sk->sk_family = PF_PPPOX;
545 sk->sk_state = PPPOX_NONE;
546 sk->sk_type = SOCK_STREAM;
547 sk->sk_destruct = pppol2tp_session_destruct;
548
549 error = 0;
550
551 out:
552 return error;
553 }
554
555 #if IS_ENABLED(CONFIG_L2TP_DEBUGFS)
556 static void pppol2tp_show(struct seq_file *m, void *arg)
557 {
558 struct l2tp_session *session = arg;
559 struct sock *sk;
560
561 sk = pppol2tp_session_get_sock(session);
562 if (sk) {
563 struct pppox_sock *po = pppox_sk(sk);
564
565 seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan));
566 sock_put(sk);
567 }
568 }
569 #endif
570
571 static void pppol2tp_session_init(struct l2tp_session *session)
572 {
573 struct pppol2tp_session *ps;
574 struct dst_entry *dst;
575
576 session->recv_skb = pppol2tp_recv;
577 session->session_close = pppol2tp_session_close;
578 #if IS_ENABLED(CONFIG_L2TP_DEBUGFS)
579 session->show = pppol2tp_show;
580 #endif
581
582 ps = l2tp_session_priv(session);
583 mutex_init(&ps->sk_lock);
584 ps->owner = current->pid;
585
586 /* If PMTU discovery was enabled, use the MTU that was discovered */
587 dst = sk_dst_get(session->tunnel->sock);
588 if (dst) {
589 u32 pmtu = dst_mtu(dst);
590
591 if (pmtu) {
592 session->mtu = pmtu - PPPOL2TP_HEADER_OVERHEAD;
593 session->mru = pmtu - PPPOL2TP_HEADER_OVERHEAD;
594 }
595 dst_release(dst);
596 }
597 }
598
599 /* connect() handler. Attach a PPPoX socket to a tunnel UDP socket
600 */
601 static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr,
602 int sockaddr_len, int flags)
603 {
604 struct sock *sk = sock->sk;
605 struct sockaddr_pppol2tp *sp = (struct sockaddr_pppol2tp *) uservaddr;
606 struct pppox_sock *po = pppox_sk(sk);
607 struct l2tp_session *session = NULL;
608 struct l2tp_tunnel *tunnel;
609 struct pppol2tp_session *ps;
610 struct l2tp_session_cfg cfg = { 0, };
611 int error = 0;
612 u32 tunnel_id, peer_tunnel_id;
613 u32 session_id, peer_session_id;
614 bool drop_refcnt = false;
615 bool drop_tunnel = false;
616 int ver = 2;
617 int fd;
618
619 lock_sock(sk);
620
621 error = -EINVAL;
622 if (sp->sa_protocol != PX_PROTO_OL2TP)
623 goto end;
624
625 /* Check for already bound sockets */
626 error = -EBUSY;
627 if (sk->sk_state & PPPOX_CONNECTED)
628 goto end;
629
630 /* We don't supporting rebinding anyway */
631 error = -EALREADY;
632 if (sk->sk_user_data)
633 goto end; /* socket is already attached */
634
635 /* Get params from socket address. Handle L2TPv2 and L2TPv3.
636 * This is nasty because there are different sockaddr_pppol2tp
637 * structs for L2TPv2, L2TPv3, over IPv4 and IPv6. We use
638 * the sockaddr size to determine which structure the caller
639 * is using.
640 */
641 peer_tunnel_id = 0;
642 if (sockaddr_len == sizeof(struct sockaddr_pppol2tp)) {
643 fd = sp->pppol2tp.fd;
644 tunnel_id = sp->pppol2tp.s_tunnel;
645 peer_tunnel_id = sp->pppol2tp.d_tunnel;
646 session_id = sp->pppol2tp.s_session;
647 peer_session_id = sp->pppol2tp.d_session;
648 } else if (sockaddr_len == sizeof(struct sockaddr_pppol2tpv3)) {
649 struct sockaddr_pppol2tpv3 *sp3 =
650 (struct sockaddr_pppol2tpv3 *) sp;
651 ver = 3;
652 fd = sp3->pppol2tp.fd;
653 tunnel_id = sp3->pppol2tp.s_tunnel;
654 peer_tunnel_id = sp3->pppol2tp.d_tunnel;
655 session_id = sp3->pppol2tp.s_session;
656 peer_session_id = sp3->pppol2tp.d_session;
657 } else if (sockaddr_len == sizeof(struct sockaddr_pppol2tpin6)) {
658 struct sockaddr_pppol2tpin6 *sp6 =
659 (struct sockaddr_pppol2tpin6 *) sp;
660 fd = sp6->pppol2tp.fd;
661 tunnel_id = sp6->pppol2tp.s_tunnel;
662 peer_tunnel_id = sp6->pppol2tp.d_tunnel;
663 session_id = sp6->pppol2tp.s_session;
664 peer_session_id = sp6->pppol2tp.d_session;
665 } else if (sockaddr_len == sizeof(struct sockaddr_pppol2tpv3in6)) {
666 struct sockaddr_pppol2tpv3in6 *sp6 =
667 (struct sockaddr_pppol2tpv3in6 *) sp;
668 ver = 3;
669 fd = sp6->pppol2tp.fd;
670 tunnel_id = sp6->pppol2tp.s_tunnel;
671 peer_tunnel_id = sp6->pppol2tp.d_tunnel;
672 session_id = sp6->pppol2tp.s_session;
673 peer_session_id = sp6->pppol2tp.d_session;
674 } else {
675 error = -EINVAL;
676 goto end; /* bad socket address */
677 }
678
679 /* Don't bind if tunnel_id is 0 */
680 error = -EINVAL;
681 if (tunnel_id == 0)
682 goto end;
683
684 tunnel = l2tp_tunnel_get(sock_net(sk), tunnel_id);
685 if (tunnel)
686 drop_tunnel = true;
687
688 /* Special case: create tunnel context if session_id and
689 * peer_session_id is 0. Otherwise look up tunnel using supplied
690 * tunnel id.
691 */
692 if ((session_id == 0) && (peer_session_id == 0)) {
693 if (tunnel == NULL) {
694 struct l2tp_tunnel_cfg tcfg = {
695 .encap = L2TP_ENCAPTYPE_UDP,
696 .debug = 0,
697 };
698 error = l2tp_tunnel_create(sock_net(sk), fd, ver, tunnel_id, peer_tunnel_id, &tcfg, &tunnel);
699 if (error < 0)
700 goto end;
701 }
702 } else {
703 /* Error if we can't find the tunnel */
704 error = -ENOENT;
705 if (tunnel == NULL)
706 goto end;
707
708 /* Error if socket is not prepped */
709 if (tunnel->sock == NULL)
710 goto end;
711 }
712
713 if (tunnel->recv_payload_hook == NULL)
714 tunnel->recv_payload_hook = pppol2tp_recv_payload_hook;
715
716 if (tunnel->peer_tunnel_id == 0)
717 tunnel->peer_tunnel_id = peer_tunnel_id;
718
719 session = l2tp_session_get(sock_net(sk), tunnel, session_id);
720 if (session) {
721 drop_refcnt = true;
722 ps = l2tp_session_priv(session);
723
724 /* Using a pre-existing session is fine as long as it hasn't
725 * been connected yet.
726 */
727 mutex_lock(&ps->sk_lock);
728 if (rcu_dereference_protected(ps->sk,
729 lockdep_is_held(&ps->sk_lock))) {
730 mutex_unlock(&ps->sk_lock);
731 error = -EEXIST;
732 goto end;
733 }
734 } else {
735 /* Default MTU must allow space for UDP/L2TP/PPP headers */
736 cfg.mtu = 1500 - PPPOL2TP_HEADER_OVERHEAD;
737 cfg.mru = cfg.mtu;
738
739 session = l2tp_session_create(sizeof(struct pppol2tp_session),
740 tunnel, session_id,
741 peer_session_id, &cfg);
742 if (IS_ERR(session)) {
743 error = PTR_ERR(session);
744 goto end;
745 }
746
747 pppol2tp_session_init(session);
748 ps = l2tp_session_priv(session);
749 l2tp_session_inc_refcount(session);
750
751 mutex_lock(&ps->sk_lock);
752 error = l2tp_session_register(session, tunnel);
753 if (error < 0) {
754 mutex_unlock(&ps->sk_lock);
755 kfree(session);
756 goto end;
757 }
758 drop_refcnt = true;
759 }
760
761 /* Special case: if source & dest session_id == 0x0000, this
762 * socket is being created to manage the tunnel. Just set up
763 * the internal context for use by ioctl() and sockopt()
764 * handlers.
765 */
766 if ((session->session_id == 0) &&
767 (session->peer_session_id == 0)) {
768 error = 0;
769 goto out_no_ppp;
770 }
771
772 /* The only header we need to worry about is the L2TP
773 * header. This size is different depending on whether
774 * sequence numbers are enabled for the data channel.
775 */
776 po->chan.hdrlen = PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
777
778 po->chan.private = sk;
779 po->chan.ops = &pppol2tp_chan_ops;
780 po->chan.mtu = session->mtu;
781
782 error = ppp_register_net_channel(sock_net(sk), &po->chan);
783 if (error) {
784 mutex_unlock(&ps->sk_lock);
785 goto end;
786 }
787
788 out_no_ppp:
789 /* This is how we get the session context from the socket. */
790 sock_hold(sk);
791 sk->sk_user_data = session;
792 rcu_assign_pointer(ps->sk, sk);
793 mutex_unlock(&ps->sk_lock);
794
795 /* Keep the reference we've grabbed on the session: sk doesn't expect
796 * the session to disappear. pppol2tp_session_destruct() is responsible
797 * for dropping it.
798 */
799 drop_refcnt = false;
800
801 sk->sk_state = PPPOX_CONNECTED;
802 l2tp_info(session, L2TP_MSG_CONTROL, "%s: created\n",
803 session->name);
804
805 end:
806 if (drop_refcnt)
807 l2tp_session_dec_refcount(session);
808 if (drop_tunnel)
809 l2tp_tunnel_dec_refcount(tunnel);
810 release_sock(sk);
811
812 return error;
813 }
814
815 #ifdef CONFIG_L2TP_V3
816
817 /* Called when creating sessions via the netlink interface. */
818 static int pppol2tp_session_create(struct net *net, struct l2tp_tunnel *tunnel,
819 u32 session_id, u32 peer_session_id,
820 struct l2tp_session_cfg *cfg)
821 {
822 int error;
823 struct l2tp_session *session;
824
825 /* Error if tunnel socket is not prepped */
826 if (!tunnel->sock) {
827 error = -ENOENT;
828 goto err;
829 }
830
831 /* Default MTU values. */
832 if (cfg->mtu == 0)
833 cfg->mtu = 1500 - PPPOL2TP_HEADER_OVERHEAD;
834 if (cfg->mru == 0)
835 cfg->mru = cfg->mtu;
836
837 /* Allocate and initialize a new session context. */
838 session = l2tp_session_create(sizeof(struct pppol2tp_session),
839 tunnel, session_id,
840 peer_session_id, cfg);
841 if (IS_ERR(session)) {
842 error = PTR_ERR(session);
843 goto err;
844 }
845
846 pppol2tp_session_init(session);
847
848 error = l2tp_session_register(session, tunnel);
849 if (error < 0)
850 goto err_sess;
851
852 return 0;
853
854 err_sess:
855 kfree(session);
856 err:
857 return error;
858 }
859
860 #endif /* CONFIG_L2TP_V3 */
861
862 /* getname() support.
863 */
864 static int pppol2tp_getname(struct socket *sock, struct sockaddr *uaddr,
865 int peer)
866 {
867 int len = 0;
868 int error = 0;
869 struct l2tp_session *session;
870 struct l2tp_tunnel *tunnel;
871 struct sock *sk = sock->sk;
872 struct inet_sock *inet;
873 struct pppol2tp_session *pls;
874
875 error = -ENOTCONN;
876 if (sk == NULL)
877 goto end;
878 if (!(sk->sk_state & PPPOX_CONNECTED))
879 goto end;
880
881 error = -EBADF;
882 session = pppol2tp_sock_to_session(sk);
883 if (session == NULL)
884 goto end;
885
886 pls = l2tp_session_priv(session);
887 tunnel = session->tunnel;
888
889 inet = inet_sk(tunnel->sock);
890 if ((tunnel->version == 2) && (tunnel->sock->sk_family == AF_INET)) {
891 struct sockaddr_pppol2tp sp;
892 len = sizeof(sp);
893 memset(&sp, 0, len);
894 sp.sa_family = AF_PPPOX;
895 sp.sa_protocol = PX_PROTO_OL2TP;
896 sp.pppol2tp.fd = tunnel->fd;
897 sp.pppol2tp.pid = pls->owner;
898 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
899 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
900 sp.pppol2tp.s_session = session->session_id;
901 sp.pppol2tp.d_session = session->peer_session_id;
902 sp.pppol2tp.addr.sin_family = AF_INET;
903 sp.pppol2tp.addr.sin_port = inet->inet_dport;
904 sp.pppol2tp.addr.sin_addr.s_addr = inet->inet_daddr;
905 memcpy(uaddr, &sp, len);
906 #if IS_ENABLED(CONFIG_IPV6)
907 } else if ((tunnel->version == 2) &&
908 (tunnel->sock->sk_family == AF_INET6)) {
909 struct sockaddr_pppol2tpin6 sp;
910
911 len = sizeof(sp);
912 memset(&sp, 0, len);
913 sp.sa_family = AF_PPPOX;
914 sp.sa_protocol = PX_PROTO_OL2TP;
915 sp.pppol2tp.fd = tunnel->fd;
916 sp.pppol2tp.pid = pls->owner;
917 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
918 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
919 sp.pppol2tp.s_session = session->session_id;
920 sp.pppol2tp.d_session = session->peer_session_id;
921 sp.pppol2tp.addr.sin6_family = AF_INET6;
922 sp.pppol2tp.addr.sin6_port = inet->inet_dport;
923 memcpy(&sp.pppol2tp.addr.sin6_addr, &tunnel->sock->sk_v6_daddr,
924 sizeof(tunnel->sock->sk_v6_daddr));
925 memcpy(uaddr, &sp, len);
926 } else if ((tunnel->version == 3) &&
927 (tunnel->sock->sk_family == AF_INET6)) {
928 struct sockaddr_pppol2tpv3in6 sp;
929
930 len = sizeof(sp);
931 memset(&sp, 0, len);
932 sp.sa_family = AF_PPPOX;
933 sp.sa_protocol = PX_PROTO_OL2TP;
934 sp.pppol2tp.fd = tunnel->fd;
935 sp.pppol2tp.pid = pls->owner;
936 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
937 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
938 sp.pppol2tp.s_session = session->session_id;
939 sp.pppol2tp.d_session = session->peer_session_id;
940 sp.pppol2tp.addr.sin6_family = AF_INET6;
941 sp.pppol2tp.addr.sin6_port = inet->inet_dport;
942 memcpy(&sp.pppol2tp.addr.sin6_addr, &tunnel->sock->sk_v6_daddr,
943 sizeof(tunnel->sock->sk_v6_daddr));
944 memcpy(uaddr, &sp, len);
945 #endif
946 } else if (tunnel->version == 3) {
947 struct sockaddr_pppol2tpv3 sp;
948 len = sizeof(sp);
949 memset(&sp, 0, len);
950 sp.sa_family = AF_PPPOX;
951 sp.sa_protocol = PX_PROTO_OL2TP;
952 sp.pppol2tp.fd = tunnel->fd;
953 sp.pppol2tp.pid = pls->owner;
954 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
955 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
956 sp.pppol2tp.s_session = session->session_id;
957 sp.pppol2tp.d_session = session->peer_session_id;
958 sp.pppol2tp.addr.sin_family = AF_INET;
959 sp.pppol2tp.addr.sin_port = inet->inet_dport;
960 sp.pppol2tp.addr.sin_addr.s_addr = inet->inet_daddr;
961 memcpy(uaddr, &sp, len);
962 }
963
964 error = len;
965
966 sock_put(sk);
967 end:
968 return error;
969 }
970
971 /****************************************************************************
972 * ioctl() handlers.
973 *
974 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
975 * sockets. However, in order to control kernel tunnel features, we allow
976 * userspace to create a special "tunnel" PPPoX socket which is used for
977 * control only. Tunnel PPPoX sockets have session_id == 0 and simply allow
978 * the user application to issue L2TP setsockopt(), getsockopt() and ioctl()
979 * calls.
980 ****************************************************************************/
981
982 static void pppol2tp_copy_stats(struct pppol2tp_ioc_stats *dest,
983 struct l2tp_stats *stats)
984 {
985 dest->tx_packets = atomic_long_read(&stats->tx_packets);
986 dest->tx_bytes = atomic_long_read(&stats->tx_bytes);
987 dest->tx_errors = atomic_long_read(&stats->tx_errors);
988 dest->rx_packets = atomic_long_read(&stats->rx_packets);
989 dest->rx_bytes = atomic_long_read(&stats->rx_bytes);
990 dest->rx_seq_discards = atomic_long_read(&stats->rx_seq_discards);
991 dest->rx_oos_packets = atomic_long_read(&stats->rx_oos_packets);
992 dest->rx_errors = atomic_long_read(&stats->rx_errors);
993 }
994
995 /* Session ioctl helper.
996 */
997 static int pppol2tp_session_ioctl(struct l2tp_session *session,
998 unsigned int cmd, unsigned long arg)
999 {
1000 struct ifreq ifr;
1001 int err = 0;
1002 struct sock *sk;
1003 int val = (int) arg;
1004 struct pppol2tp_session *ps = l2tp_session_priv(session);
1005 struct l2tp_tunnel *tunnel = session->tunnel;
1006 struct pppol2tp_ioc_stats stats;
1007
1008 l2tp_dbg(session, L2TP_MSG_CONTROL,
1009 "%s: pppol2tp_session_ioctl(cmd=%#x, arg=%#lx)\n",
1010 session->name, cmd, arg);
1011
1012 sk = pppol2tp_session_get_sock(session);
1013 if (!sk)
1014 return -EBADR;
1015
1016 switch (cmd) {
1017 case SIOCGIFMTU:
1018 err = -ENXIO;
1019 if (!(sk->sk_state & PPPOX_CONNECTED))
1020 break;
1021
1022 err = -EFAULT;
1023 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq)))
1024 break;
1025 ifr.ifr_mtu = session->mtu;
1026 if (copy_to_user((void __user *) arg, &ifr, sizeof(struct ifreq)))
1027 break;
1028
1029 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get mtu=%d\n",
1030 session->name, session->mtu);
1031 err = 0;
1032 break;
1033
1034 case SIOCSIFMTU:
1035 err = -ENXIO;
1036 if (!(sk->sk_state & PPPOX_CONNECTED))
1037 break;
1038
1039 err = -EFAULT;
1040 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq)))
1041 break;
1042
1043 session->mtu = ifr.ifr_mtu;
1044
1045 l2tp_info(session, L2TP_MSG_CONTROL, "%s: set mtu=%d\n",
1046 session->name, session->mtu);
1047 err = 0;
1048 break;
1049
1050 case PPPIOCGMRU:
1051 err = -ENXIO;
1052 if (!(sk->sk_state & PPPOX_CONNECTED))
1053 break;
1054
1055 err = -EFAULT;
1056 if (put_user(session->mru, (int __user *) arg))
1057 break;
1058
1059 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get mru=%d\n",
1060 session->name, session->mru);
1061 err = 0;
1062 break;
1063
1064 case PPPIOCSMRU:
1065 err = -ENXIO;
1066 if (!(sk->sk_state & PPPOX_CONNECTED))
1067 break;
1068
1069 err = -EFAULT;
1070 if (get_user(val, (int __user *) arg))
1071 break;
1072
1073 session->mru = val;
1074 l2tp_info(session, L2TP_MSG_CONTROL, "%s: set mru=%d\n",
1075 session->name, session->mru);
1076 err = 0;
1077 break;
1078
1079 case PPPIOCGFLAGS:
1080 err = -EFAULT;
1081 if (put_user(ps->flags, (int __user *) arg))
1082 break;
1083
1084 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get flags=%d\n",
1085 session->name, ps->flags);
1086 err = 0;
1087 break;
1088
1089 case PPPIOCSFLAGS:
1090 err = -EFAULT;
1091 if (get_user(val, (int __user *) arg))
1092 break;
1093 ps->flags = val;
1094 l2tp_info(session, L2TP_MSG_CONTROL, "%s: set flags=%d\n",
1095 session->name, ps->flags);
1096 err = 0;
1097 break;
1098
1099 case PPPIOCGL2TPSTATS:
1100 err = -ENXIO;
1101 if (!(sk->sk_state & PPPOX_CONNECTED))
1102 break;
1103
1104 memset(&stats, 0, sizeof(stats));
1105 stats.tunnel_id = tunnel->tunnel_id;
1106 stats.session_id = session->session_id;
1107 pppol2tp_copy_stats(&stats, &session->stats);
1108 if (copy_to_user((void __user *) arg, &stats,
1109 sizeof(stats)))
1110 break;
1111 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get L2TP stats\n",
1112 session->name);
1113 err = 0;
1114 break;
1115
1116 default:
1117 err = -ENOSYS;
1118 break;
1119 }
1120
1121 sock_put(sk);
1122
1123 return err;
1124 }
1125
1126 /* Tunnel ioctl helper.
1127 *
1128 * Note the special handling for PPPIOCGL2TPSTATS below. If the ioctl data
1129 * specifies a session_id, the session ioctl handler is called. This allows an
1130 * application to retrieve session stats via a tunnel socket.
1131 */
1132 static int pppol2tp_tunnel_ioctl(struct l2tp_tunnel *tunnel,
1133 unsigned int cmd, unsigned long arg)
1134 {
1135 int err = 0;
1136 struct sock *sk;
1137 struct pppol2tp_ioc_stats stats;
1138
1139 l2tp_dbg(tunnel, L2TP_MSG_CONTROL,
1140 "%s: pppol2tp_tunnel_ioctl(cmd=%#x, arg=%#lx)\n",
1141 tunnel->name, cmd, arg);
1142
1143 sk = tunnel->sock;
1144 sock_hold(sk);
1145
1146 switch (cmd) {
1147 case PPPIOCGL2TPSTATS:
1148 err = -ENXIO;
1149 if (!(sk->sk_state & PPPOX_CONNECTED))
1150 break;
1151
1152 if (copy_from_user(&stats, (void __user *) arg,
1153 sizeof(stats))) {
1154 err = -EFAULT;
1155 break;
1156 }
1157 if (stats.session_id != 0) {
1158 /* resend to session ioctl handler */
1159 struct l2tp_session *session =
1160 l2tp_session_get(sock_net(sk), tunnel,
1161 stats.session_id);
1162
1163 if (session) {
1164 err = pppol2tp_session_ioctl(session, cmd,
1165 arg);
1166 l2tp_session_dec_refcount(session);
1167 } else {
1168 err = -EBADR;
1169 }
1170 break;
1171 }
1172 #ifdef CONFIG_XFRM
1173 stats.using_ipsec = (sk->sk_policy[0] || sk->sk_policy[1]) ? 1 : 0;
1174 #endif
1175 pppol2tp_copy_stats(&stats, &tunnel->stats);
1176 if (copy_to_user((void __user *) arg, &stats, sizeof(stats))) {
1177 err = -EFAULT;
1178 break;
1179 }
1180 l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: get L2TP stats\n",
1181 tunnel->name);
1182 err = 0;
1183 break;
1184
1185 default:
1186 err = -ENOSYS;
1187 break;
1188 }
1189
1190 sock_put(sk);
1191
1192 return err;
1193 }
1194
1195 /* Main ioctl() handler.
1196 * Dispatch to tunnel or session helpers depending on the socket.
1197 */
1198 static int pppol2tp_ioctl(struct socket *sock, unsigned int cmd,
1199 unsigned long arg)
1200 {
1201 struct sock *sk = sock->sk;
1202 struct l2tp_session *session;
1203 struct l2tp_tunnel *tunnel;
1204 int err;
1205
1206 if (!sk)
1207 return 0;
1208
1209 err = -EBADF;
1210 if (sock_flag(sk, SOCK_DEAD) != 0)
1211 goto end;
1212
1213 err = -ENOTCONN;
1214 if ((sk->sk_user_data == NULL) ||
1215 (!(sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND))))
1216 goto end;
1217
1218 /* Get session context from the socket */
1219 err = -EBADF;
1220 session = pppol2tp_sock_to_session(sk);
1221 if (session == NULL)
1222 goto end;
1223
1224 /* Special case: if session's session_id is zero, treat ioctl as a
1225 * tunnel ioctl
1226 */
1227 if ((session->session_id == 0) &&
1228 (session->peer_session_id == 0)) {
1229 tunnel = session->tunnel;
1230 err = pppol2tp_tunnel_ioctl(tunnel, cmd, arg);
1231 goto end_put_sess;
1232 }
1233
1234 err = pppol2tp_session_ioctl(session, cmd, arg);
1235
1236 end_put_sess:
1237 sock_put(sk);
1238 end:
1239 return err;
1240 }
1241
1242 /*****************************************************************************
1243 * setsockopt() / getsockopt() support.
1244 *
1245 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
1246 * sockets. In order to control kernel tunnel features, we allow userspace to
1247 * create a special "tunnel" PPPoX socket which is used for control only.
1248 * Tunnel PPPoX sockets have session_id == 0 and simply allow the user
1249 * application to issue L2TP setsockopt(), getsockopt() and ioctl() calls.
1250 *****************************************************************************/
1251
1252 /* Tunnel setsockopt() helper.
1253 */
1254 static int pppol2tp_tunnel_setsockopt(struct sock *sk,
1255 struct l2tp_tunnel *tunnel,
1256 int optname, int val)
1257 {
1258 int err = 0;
1259
1260 switch (optname) {
1261 case PPPOL2TP_SO_DEBUG:
1262 tunnel->debug = val;
1263 l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: set debug=%x\n",
1264 tunnel->name, tunnel->debug);
1265 break;
1266
1267 default:
1268 err = -ENOPROTOOPT;
1269 break;
1270 }
1271
1272 return err;
1273 }
1274
1275 /* Session setsockopt helper.
1276 */
1277 static int pppol2tp_session_setsockopt(struct sock *sk,
1278 struct l2tp_session *session,
1279 int optname, int val)
1280 {
1281 int err = 0;
1282
1283 switch (optname) {
1284 case PPPOL2TP_SO_RECVSEQ:
1285 if ((val != 0) && (val != 1)) {
1286 err = -EINVAL;
1287 break;
1288 }
1289 session->recv_seq = !!val;
1290 l2tp_info(session, L2TP_MSG_CONTROL,
1291 "%s: set recv_seq=%d\n",
1292 session->name, session->recv_seq);
1293 break;
1294
1295 case PPPOL2TP_SO_SENDSEQ:
1296 if ((val != 0) && (val != 1)) {
1297 err = -EINVAL;
1298 break;
1299 }
1300 session->send_seq = !!val;
1301 {
1302 struct pppox_sock *po = pppox_sk(sk);
1303
1304 po->chan.hdrlen = val ? PPPOL2TP_L2TP_HDR_SIZE_SEQ :
1305 PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
1306 }
1307 l2tp_session_set_header_len(session, session->tunnel->version);
1308 l2tp_info(session, L2TP_MSG_CONTROL,
1309 "%s: set send_seq=%d\n",
1310 session->name, session->send_seq);
1311 break;
1312
1313 case PPPOL2TP_SO_LNSMODE:
1314 if ((val != 0) && (val != 1)) {
1315 err = -EINVAL;
1316 break;
1317 }
1318 session->lns_mode = !!val;
1319 l2tp_info(session, L2TP_MSG_CONTROL,
1320 "%s: set lns_mode=%d\n",
1321 session->name, session->lns_mode);
1322 break;
1323
1324 case PPPOL2TP_SO_DEBUG:
1325 session->debug = val;
1326 l2tp_info(session, L2TP_MSG_CONTROL, "%s: set debug=%x\n",
1327 session->name, session->debug);
1328 break;
1329
1330 case PPPOL2TP_SO_REORDERTO:
1331 session->reorder_timeout = msecs_to_jiffies(val);
1332 l2tp_info(session, L2TP_MSG_CONTROL,
1333 "%s: set reorder_timeout=%d\n",
1334 session->name, session->reorder_timeout);
1335 break;
1336
1337 default:
1338 err = -ENOPROTOOPT;
1339 break;
1340 }
1341
1342 return err;
1343 }
1344
1345 /* Main setsockopt() entry point.
1346 * Does API checks, then calls either the tunnel or session setsockopt
1347 * handler, according to whether the PPPoL2TP socket is a for a regular
1348 * session or the special tunnel type.
1349 */
1350 static int pppol2tp_setsockopt(struct socket *sock, int level, int optname,
1351 char __user *optval, unsigned int optlen)
1352 {
1353 struct sock *sk = sock->sk;
1354 struct l2tp_session *session;
1355 struct l2tp_tunnel *tunnel;
1356 int val;
1357 int err;
1358
1359 if (level != SOL_PPPOL2TP)
1360 return -EINVAL;
1361
1362 if (optlen < sizeof(int))
1363 return -EINVAL;
1364
1365 if (get_user(val, (int __user *)optval))
1366 return -EFAULT;
1367
1368 err = -ENOTCONN;
1369 if (sk->sk_user_data == NULL)
1370 goto end;
1371
1372 /* Get session context from the socket */
1373 err = -EBADF;
1374 session = pppol2tp_sock_to_session(sk);
1375 if (session == NULL)
1376 goto end;
1377
1378 /* Special case: if session_id == 0x0000, treat as operation on tunnel
1379 */
1380 if ((session->session_id == 0) &&
1381 (session->peer_session_id == 0)) {
1382 tunnel = session->tunnel;
1383 err = pppol2tp_tunnel_setsockopt(sk, tunnel, optname, val);
1384 } else {
1385 err = pppol2tp_session_setsockopt(sk, session, optname, val);
1386 }
1387
1388 sock_put(sk);
1389 end:
1390 return err;
1391 }
1392
1393 /* Tunnel getsockopt helper. Called with sock locked.
1394 */
1395 static int pppol2tp_tunnel_getsockopt(struct sock *sk,
1396 struct l2tp_tunnel *tunnel,
1397 int optname, int *val)
1398 {
1399 int err = 0;
1400
1401 switch (optname) {
1402 case PPPOL2TP_SO_DEBUG:
1403 *val = tunnel->debug;
1404 l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: get debug=%x\n",
1405 tunnel->name, tunnel->debug);
1406 break;
1407
1408 default:
1409 err = -ENOPROTOOPT;
1410 break;
1411 }
1412
1413 return err;
1414 }
1415
1416 /* Session getsockopt helper. Called with sock locked.
1417 */
1418 static int pppol2tp_session_getsockopt(struct sock *sk,
1419 struct l2tp_session *session,
1420 int optname, int *val)
1421 {
1422 int err = 0;
1423
1424 switch (optname) {
1425 case PPPOL2TP_SO_RECVSEQ:
1426 *val = session->recv_seq;
1427 l2tp_info(session, L2TP_MSG_CONTROL,
1428 "%s: get recv_seq=%d\n", session->name, *val);
1429 break;
1430
1431 case PPPOL2TP_SO_SENDSEQ:
1432 *val = session->send_seq;
1433 l2tp_info(session, L2TP_MSG_CONTROL,
1434 "%s: get send_seq=%d\n", session->name, *val);
1435 break;
1436
1437 case PPPOL2TP_SO_LNSMODE:
1438 *val = session->lns_mode;
1439 l2tp_info(session, L2TP_MSG_CONTROL,
1440 "%s: get lns_mode=%d\n", session->name, *val);
1441 break;
1442
1443 case PPPOL2TP_SO_DEBUG:
1444 *val = session->debug;
1445 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get debug=%d\n",
1446 session->name, *val);
1447 break;
1448
1449 case PPPOL2TP_SO_REORDERTO:
1450 *val = (int) jiffies_to_msecs(session->reorder_timeout);
1451 l2tp_info(session, L2TP_MSG_CONTROL,
1452 "%s: get reorder_timeout=%d\n", session->name, *val);
1453 break;
1454
1455 default:
1456 err = -ENOPROTOOPT;
1457 }
1458
1459 return err;
1460 }
1461
1462 /* Main getsockopt() entry point.
1463 * Does API checks, then calls either the tunnel or session getsockopt
1464 * handler, according to whether the PPPoX socket is a for a regular session
1465 * or the special tunnel type.
1466 */
1467 static int pppol2tp_getsockopt(struct socket *sock, int level, int optname,
1468 char __user *optval, int __user *optlen)
1469 {
1470 struct sock *sk = sock->sk;
1471 struct l2tp_session *session;
1472 struct l2tp_tunnel *tunnel;
1473 int val, len;
1474 int err;
1475
1476 if (level != SOL_PPPOL2TP)
1477 return -EINVAL;
1478
1479 if (get_user(len, optlen))
1480 return -EFAULT;
1481
1482 len = min_t(unsigned int, len, sizeof(int));
1483
1484 if (len < 0)
1485 return -EINVAL;
1486
1487 err = -ENOTCONN;
1488 if (sk->sk_user_data == NULL)
1489 goto end;
1490
1491 /* Get the session context */
1492 err = -EBADF;
1493 session = pppol2tp_sock_to_session(sk);
1494 if (session == NULL)
1495 goto end;
1496
1497 /* Special case: if session_id == 0x0000, treat as operation on tunnel */
1498 if ((session->session_id == 0) &&
1499 (session->peer_session_id == 0)) {
1500 tunnel = session->tunnel;
1501 err = pppol2tp_tunnel_getsockopt(sk, tunnel, optname, &val);
1502 if (err)
1503 goto end_put_sess;
1504 } else {
1505 err = pppol2tp_session_getsockopt(sk, session, optname, &val);
1506 if (err)
1507 goto end_put_sess;
1508 }
1509
1510 err = -EFAULT;
1511 if (put_user(len, optlen))
1512 goto end_put_sess;
1513
1514 if (copy_to_user((void __user *) optval, &val, len))
1515 goto end_put_sess;
1516
1517 err = 0;
1518
1519 end_put_sess:
1520 sock_put(sk);
1521 end:
1522 return err;
1523 }
1524
1525 /*****************************************************************************
1526 * /proc filesystem for debug
1527 * Since the original pppol2tp driver provided /proc/net/pppol2tp for
1528 * L2TPv2, we dump only L2TPv2 tunnels and sessions here.
1529 *****************************************************************************/
1530
1531 static unsigned int pppol2tp_net_id;
1532
1533 #ifdef CONFIG_PROC_FS
1534
1535 struct pppol2tp_seq_data {
1536 struct seq_net_private p;
1537 int tunnel_idx; /* current tunnel */
1538 int session_idx; /* index of session within current tunnel */
1539 struct l2tp_tunnel *tunnel;
1540 struct l2tp_session *session; /* NULL means get next tunnel */
1541 };
1542
1543 static void pppol2tp_next_tunnel(struct net *net, struct pppol2tp_seq_data *pd)
1544 {
1545 for (;;) {
1546 pd->tunnel = l2tp_tunnel_find_nth(net, pd->tunnel_idx);
1547 pd->tunnel_idx++;
1548
1549 if (pd->tunnel == NULL)
1550 break;
1551
1552 /* Ignore L2TPv3 tunnels */
1553 if (pd->tunnel->version < 3)
1554 break;
1555 }
1556 }
1557
1558 static void pppol2tp_next_session(struct net *net, struct pppol2tp_seq_data *pd)
1559 {
1560 pd->session = l2tp_session_get_nth(pd->tunnel, pd->session_idx);
1561 pd->session_idx++;
1562
1563 if (pd->session == NULL) {
1564 pd->session_idx = 0;
1565 pppol2tp_next_tunnel(net, pd);
1566 }
1567 }
1568
1569 static void *pppol2tp_seq_start(struct seq_file *m, loff_t *offs)
1570 {
1571 struct pppol2tp_seq_data *pd = SEQ_START_TOKEN;
1572 loff_t pos = *offs;
1573 struct net *net;
1574
1575 if (!pos)
1576 goto out;
1577
1578 BUG_ON(m->private == NULL);
1579 pd = m->private;
1580 net = seq_file_net(m);
1581
1582 if (pd->tunnel == NULL)
1583 pppol2tp_next_tunnel(net, pd);
1584 else
1585 pppol2tp_next_session(net, pd);
1586
1587 /* NULL tunnel and session indicates end of list */
1588 if ((pd->tunnel == NULL) && (pd->session == NULL))
1589 pd = NULL;
1590
1591 out:
1592 return pd;
1593 }
1594
1595 static void *pppol2tp_seq_next(struct seq_file *m, void *v, loff_t *pos)
1596 {
1597 (*pos)++;
1598 return NULL;
1599 }
1600
1601 static void pppol2tp_seq_stop(struct seq_file *p, void *v)
1602 {
1603 /* nothing to do */
1604 }
1605
1606 static void pppol2tp_seq_tunnel_show(struct seq_file *m, void *v)
1607 {
1608 struct l2tp_tunnel *tunnel = v;
1609
1610 seq_printf(m, "\nTUNNEL '%s', %c %d\n",
1611 tunnel->name,
1612 (tunnel == tunnel->sock->sk_user_data) ? 'Y' : 'N',
1613 refcount_read(&tunnel->ref_count) - 1);
1614 seq_printf(m, " %08x %ld/%ld/%ld %ld/%ld/%ld\n",
1615 tunnel->debug,
1616 atomic_long_read(&tunnel->stats.tx_packets),
1617 atomic_long_read(&tunnel->stats.tx_bytes),
1618 atomic_long_read(&tunnel->stats.tx_errors),
1619 atomic_long_read(&tunnel->stats.rx_packets),
1620 atomic_long_read(&tunnel->stats.rx_bytes),
1621 atomic_long_read(&tunnel->stats.rx_errors));
1622 }
1623
1624 static void pppol2tp_seq_session_show(struct seq_file *m, void *v)
1625 {
1626 struct l2tp_session *session = v;
1627 struct l2tp_tunnel *tunnel = session->tunnel;
1628 unsigned char state;
1629 char user_data_ok;
1630 struct sock *sk;
1631 u32 ip = 0;
1632 u16 port = 0;
1633
1634 if (tunnel->sock) {
1635 struct inet_sock *inet = inet_sk(tunnel->sock);
1636 ip = ntohl(inet->inet_saddr);
1637 port = ntohs(inet->inet_sport);
1638 }
1639
1640 sk = pppol2tp_session_get_sock(session);
1641 if (sk) {
1642 state = sk->sk_state;
1643 user_data_ok = (session == sk->sk_user_data) ? 'Y' : 'N';
1644 } else {
1645 state = 0;
1646 user_data_ok = 'N';
1647 }
1648
1649 seq_printf(m, " SESSION '%s' %08X/%d %04X/%04X -> "
1650 "%04X/%04X %d %c\n",
1651 session->name, ip, port,
1652 tunnel->tunnel_id,
1653 session->session_id,
1654 tunnel->peer_tunnel_id,
1655 session->peer_session_id,
1656 state, user_data_ok);
1657 seq_printf(m, " %d/%d/%c/%c/%s %08x %u\n",
1658 session->mtu, session->mru,
1659 session->recv_seq ? 'R' : '-',
1660 session->send_seq ? 'S' : '-',
1661 session->lns_mode ? "LNS" : "LAC",
1662 session->debug,
1663 jiffies_to_msecs(session->reorder_timeout));
1664 seq_printf(m, " %hu/%hu %ld/%ld/%ld %ld/%ld/%ld\n",
1665 session->nr, session->ns,
1666 atomic_long_read(&session->stats.tx_packets),
1667 atomic_long_read(&session->stats.tx_bytes),
1668 atomic_long_read(&session->stats.tx_errors),
1669 atomic_long_read(&session->stats.rx_packets),
1670 atomic_long_read(&session->stats.rx_bytes),
1671 atomic_long_read(&session->stats.rx_errors));
1672
1673 if (sk) {
1674 struct pppox_sock *po = pppox_sk(sk);
1675
1676 seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan));
1677 sock_put(sk);
1678 }
1679 }
1680
1681 static int pppol2tp_seq_show(struct seq_file *m, void *v)
1682 {
1683 struct pppol2tp_seq_data *pd = v;
1684
1685 /* display header on line 1 */
1686 if (v == SEQ_START_TOKEN) {
1687 seq_puts(m, "PPPoL2TP driver info, " PPPOL2TP_DRV_VERSION "\n");
1688 seq_puts(m, "TUNNEL name, user-data-ok session-count\n");
1689 seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
1690 seq_puts(m, " SESSION name, addr/port src-tid/sid "
1691 "dest-tid/sid state user-data-ok\n");
1692 seq_puts(m, " mtu/mru/rcvseq/sendseq/lns debug reorderto\n");
1693 seq_puts(m, " nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
1694 goto out;
1695 }
1696
1697 /* Show the tunnel or session context.
1698 */
1699 if (!pd->session) {
1700 pppol2tp_seq_tunnel_show(m, pd->tunnel);
1701 } else {
1702 pppol2tp_seq_session_show(m, pd->session);
1703 l2tp_session_dec_refcount(pd->session);
1704 }
1705
1706 out:
1707 return 0;
1708 }
1709
1710 static const struct seq_operations pppol2tp_seq_ops = {
1711 .start = pppol2tp_seq_start,
1712 .next = pppol2tp_seq_next,
1713 .stop = pppol2tp_seq_stop,
1714 .show = pppol2tp_seq_show,
1715 };
1716
1717 /* Called when our /proc file is opened. We allocate data for use when
1718 * iterating our tunnel / session contexts and store it in the private
1719 * data of the seq_file.
1720 */
1721 static int pppol2tp_proc_open(struct inode *inode, struct file *file)
1722 {
1723 return seq_open_net(inode, file, &pppol2tp_seq_ops,
1724 sizeof(struct pppol2tp_seq_data));
1725 }
1726
1727 static const struct file_operations pppol2tp_proc_fops = {
1728 .open = pppol2tp_proc_open,
1729 .read = seq_read,
1730 .llseek = seq_lseek,
1731 .release = seq_release_net,
1732 };
1733
1734 #endif /* CONFIG_PROC_FS */
1735
1736 /*****************************************************************************
1737 * Network namespace
1738 *****************************************************************************/
1739
1740 static __net_init int pppol2tp_init_net(struct net *net)
1741 {
1742 struct proc_dir_entry *pde;
1743 int err = 0;
1744
1745 pde = proc_create("pppol2tp", 0444, net->proc_net,
1746 &pppol2tp_proc_fops);
1747 if (!pde) {
1748 err = -ENOMEM;
1749 goto out;
1750 }
1751
1752 out:
1753 return err;
1754 }
1755
1756 static __net_exit void pppol2tp_exit_net(struct net *net)
1757 {
1758 remove_proc_entry("pppol2tp", net->proc_net);
1759 }
1760
1761 static struct pernet_operations pppol2tp_net_ops = {
1762 .init = pppol2tp_init_net,
1763 .exit = pppol2tp_exit_net,
1764 .id = &pppol2tp_net_id,
1765 };
1766
1767 /*****************************************************************************
1768 * Init and cleanup
1769 *****************************************************************************/
1770
1771 static const struct proto_ops pppol2tp_ops = {
1772 .family = AF_PPPOX,
1773 .owner = THIS_MODULE,
1774 .release = pppol2tp_release,
1775 .bind = sock_no_bind,
1776 .connect = pppol2tp_connect,
1777 .socketpair = sock_no_socketpair,
1778 .accept = sock_no_accept,
1779 .getname = pppol2tp_getname,
1780 .poll = datagram_poll,
1781 .listen = sock_no_listen,
1782 .shutdown = sock_no_shutdown,
1783 .setsockopt = pppol2tp_setsockopt,
1784 .getsockopt = pppol2tp_getsockopt,
1785 .sendmsg = pppol2tp_sendmsg,
1786 .recvmsg = pppol2tp_recvmsg,
1787 .mmap = sock_no_mmap,
1788 .ioctl = pppox_ioctl,
1789 };
1790
1791 static const struct pppox_proto pppol2tp_proto = {
1792 .create = pppol2tp_create,
1793 .ioctl = pppol2tp_ioctl,
1794 .owner = THIS_MODULE,
1795 };
1796
1797 #ifdef CONFIG_L2TP_V3
1798
1799 static const struct l2tp_nl_cmd_ops pppol2tp_nl_cmd_ops = {
1800 .session_create = pppol2tp_session_create,
1801 .session_delete = l2tp_session_delete,
1802 };
1803
1804 #endif /* CONFIG_L2TP_V3 */
1805
1806 static int __init pppol2tp_init(void)
1807 {
1808 int err;
1809
1810 err = register_pernet_device(&pppol2tp_net_ops);
1811 if (err)
1812 goto out;
1813
1814 err = proto_register(&pppol2tp_sk_proto, 0);
1815 if (err)
1816 goto out_unregister_pppol2tp_pernet;
1817
1818 err = register_pppox_proto(PX_PROTO_OL2TP, &pppol2tp_proto);
1819 if (err)
1820 goto out_unregister_pppol2tp_proto;
1821
1822 #ifdef CONFIG_L2TP_V3
1823 err = l2tp_nl_register_ops(L2TP_PWTYPE_PPP, &pppol2tp_nl_cmd_ops);
1824 if (err)
1825 goto out_unregister_pppox;
1826 #endif
1827
1828 pr_info("PPPoL2TP kernel driver, %s\n", PPPOL2TP_DRV_VERSION);
1829
1830 out:
1831 return err;
1832
1833 #ifdef CONFIG_L2TP_V3
1834 out_unregister_pppox:
1835 unregister_pppox_proto(PX_PROTO_OL2TP);
1836 #endif
1837 out_unregister_pppol2tp_proto:
1838 proto_unregister(&pppol2tp_sk_proto);
1839 out_unregister_pppol2tp_pernet:
1840 unregister_pernet_device(&pppol2tp_net_ops);
1841 goto out;
1842 }
1843
1844 static void __exit pppol2tp_exit(void)
1845 {
1846 #ifdef CONFIG_L2TP_V3
1847 l2tp_nl_unregister_ops(L2TP_PWTYPE_PPP);
1848 #endif
1849 unregister_pppox_proto(PX_PROTO_OL2TP);
1850 proto_unregister(&pppol2tp_sk_proto);
1851 unregister_pernet_device(&pppol2tp_net_ops);
1852 }
1853
1854 module_init(pppol2tp_init);
1855 module_exit(pppol2tp_exit);
1856
1857 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
1858 MODULE_DESCRIPTION("PPP over L2TP over UDP");
1859 MODULE_LICENSE("GPL");
1860 MODULE_VERSION(PPPOL2TP_DRV_VERSION);
1861 MODULE_ALIAS_NET_PF_PROTO(PF_PPPOX, PX_PROTO_OL2TP);
1862 MODULE_ALIAS_L2TP_PWTYPE(7);
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