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Merge tag 'batadv-next-for-davem-20180302' of git://git.open-mesh.org/linux-merge
[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 /* Called by l2tp_core when a session socket is being closed.
420 */
421 static void pppol2tp_session_close(struct l2tp_session *session)
422 {
423 struct sock *sk;
424
425 BUG_ON(session->magic != L2TP_SESSION_MAGIC);
426
427 sk = pppol2tp_session_get_sock(session);
428 if (sk) {
429 if (sk->sk_socket)
430 inet_shutdown(sk->sk_socket, SEND_SHUTDOWN);
431 sock_put(sk);
432 }
433 }
434
435 /* Really kill the session socket. (Called from sock_put() if
436 * refcnt == 0.)
437 */
438 static void pppol2tp_session_destruct(struct sock *sk)
439 {
440 struct l2tp_session *session = sk->sk_user_data;
441
442 skb_queue_purge(&sk->sk_receive_queue);
443 skb_queue_purge(&sk->sk_write_queue);
444
445 if (session) {
446 sk->sk_user_data = NULL;
447 BUG_ON(session->magic != L2TP_SESSION_MAGIC);
448 l2tp_session_dec_refcount(session);
449 }
450 }
451
452 static void pppol2tp_put_sk(struct rcu_head *head)
453 {
454 struct pppol2tp_session *ps;
455
456 ps = container_of(head, typeof(*ps), rcu);
457 sock_put(ps->__sk);
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 session = pppol2tp_sock_to_session(sk);
484
485 if (session != NULL) {
486 struct pppol2tp_session *ps;
487
488 l2tp_session_delete(session);
489
490 ps = l2tp_session_priv(session);
491 mutex_lock(&ps->sk_lock);
492 ps->__sk = rcu_dereference_protected(ps->sk,
493 lockdep_is_held(&ps->sk_lock));
494 RCU_INIT_POINTER(ps->sk, NULL);
495 mutex_unlock(&ps->sk_lock);
496 call_rcu(&ps->rcu, pppol2tp_put_sk);
497
498 /* Rely on the sock_put() call at the end of the function for
499 * dropping the reference held by pppol2tp_sock_to_session().
500 * The last reference will be dropped by pppol2tp_put_sk().
501 */
502 }
503 release_sock(sk);
504
505 /* This will delete the session context via
506 * pppol2tp_session_destruct() if the socket's refcnt drops to
507 * zero.
508 */
509 sock_put(sk);
510
511 return 0;
512
513 error:
514 release_sock(sk);
515 return error;
516 }
517
518 static struct proto pppol2tp_sk_proto = {
519 .name = "PPPOL2TP",
520 .owner = THIS_MODULE,
521 .obj_size = sizeof(struct pppox_sock),
522 };
523
524 static int pppol2tp_backlog_recv(struct sock *sk, struct sk_buff *skb)
525 {
526 int rc;
527
528 rc = l2tp_udp_encap_recv(sk, skb);
529 if (rc)
530 kfree_skb(skb);
531
532 return NET_RX_SUCCESS;
533 }
534
535 /* socket() handler. Initialize a new struct sock.
536 */
537 static int pppol2tp_create(struct net *net, struct socket *sock, int kern)
538 {
539 int error = -ENOMEM;
540 struct sock *sk;
541
542 sk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, &pppol2tp_sk_proto, kern);
543 if (!sk)
544 goto out;
545
546 sock_init_data(sock, sk);
547
548 sock->state = SS_UNCONNECTED;
549 sock->ops = &pppol2tp_ops;
550
551 sk->sk_backlog_rcv = pppol2tp_backlog_recv;
552 sk->sk_protocol = PX_PROTO_OL2TP;
553 sk->sk_family = PF_PPPOX;
554 sk->sk_state = PPPOX_NONE;
555 sk->sk_type = SOCK_STREAM;
556 sk->sk_destruct = pppol2tp_session_destruct;
557
558 error = 0;
559
560 out:
561 return error;
562 }
563
564 #if IS_ENABLED(CONFIG_L2TP_DEBUGFS)
565 static void pppol2tp_show(struct seq_file *m, void *arg)
566 {
567 struct l2tp_session *session = arg;
568 struct sock *sk;
569
570 sk = pppol2tp_session_get_sock(session);
571 if (sk) {
572 struct pppox_sock *po = pppox_sk(sk);
573
574 seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan));
575 sock_put(sk);
576 }
577 }
578 #endif
579
580 static void pppol2tp_session_init(struct l2tp_session *session)
581 {
582 struct pppol2tp_session *ps;
583 struct dst_entry *dst;
584
585 session->recv_skb = pppol2tp_recv;
586 session->session_close = pppol2tp_session_close;
587 #if IS_ENABLED(CONFIG_L2TP_DEBUGFS)
588 session->show = pppol2tp_show;
589 #endif
590
591 ps = l2tp_session_priv(session);
592 mutex_init(&ps->sk_lock);
593 ps->owner = current->pid;
594
595 /* If PMTU discovery was enabled, use the MTU that was discovered */
596 dst = sk_dst_get(session->tunnel->sock);
597 if (dst) {
598 u32 pmtu = dst_mtu(dst);
599
600 if (pmtu) {
601 session->mtu = pmtu - PPPOL2TP_HEADER_OVERHEAD;
602 session->mru = pmtu - PPPOL2TP_HEADER_OVERHEAD;
603 }
604 dst_release(dst);
605 }
606 }
607
608 /* connect() handler. Attach a PPPoX socket to a tunnel UDP socket
609 */
610 static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr,
611 int sockaddr_len, int flags)
612 {
613 struct sock *sk = sock->sk;
614 struct sockaddr_pppol2tp *sp = (struct sockaddr_pppol2tp *) uservaddr;
615 struct pppox_sock *po = pppox_sk(sk);
616 struct l2tp_session *session = NULL;
617 struct l2tp_tunnel *tunnel;
618 struct pppol2tp_session *ps;
619 struct l2tp_session_cfg cfg = { 0, };
620 int error = 0;
621 u32 tunnel_id, peer_tunnel_id;
622 u32 session_id, peer_session_id;
623 bool drop_refcnt = false;
624 bool drop_tunnel = false;
625 int ver = 2;
626 int fd;
627
628 lock_sock(sk);
629
630 error = -EINVAL;
631 if (sp->sa_protocol != PX_PROTO_OL2TP)
632 goto end;
633
634 /* Check for already bound sockets */
635 error = -EBUSY;
636 if (sk->sk_state & PPPOX_CONNECTED)
637 goto end;
638
639 /* We don't supporting rebinding anyway */
640 error = -EALREADY;
641 if (sk->sk_user_data)
642 goto end; /* socket is already attached */
643
644 /* Get params from socket address. Handle L2TPv2 and L2TPv3.
645 * This is nasty because there are different sockaddr_pppol2tp
646 * structs for L2TPv2, L2TPv3, over IPv4 and IPv6. We use
647 * the sockaddr size to determine which structure the caller
648 * is using.
649 */
650 peer_tunnel_id = 0;
651 if (sockaddr_len == sizeof(struct sockaddr_pppol2tp)) {
652 fd = sp->pppol2tp.fd;
653 tunnel_id = sp->pppol2tp.s_tunnel;
654 peer_tunnel_id = sp->pppol2tp.d_tunnel;
655 session_id = sp->pppol2tp.s_session;
656 peer_session_id = sp->pppol2tp.d_session;
657 } else if (sockaddr_len == sizeof(struct sockaddr_pppol2tpv3)) {
658 struct sockaddr_pppol2tpv3 *sp3 =
659 (struct sockaddr_pppol2tpv3 *) sp;
660 ver = 3;
661 fd = sp3->pppol2tp.fd;
662 tunnel_id = sp3->pppol2tp.s_tunnel;
663 peer_tunnel_id = sp3->pppol2tp.d_tunnel;
664 session_id = sp3->pppol2tp.s_session;
665 peer_session_id = sp3->pppol2tp.d_session;
666 } else if (sockaddr_len == sizeof(struct sockaddr_pppol2tpin6)) {
667 struct sockaddr_pppol2tpin6 *sp6 =
668 (struct sockaddr_pppol2tpin6 *) sp;
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 if (sockaddr_len == sizeof(struct sockaddr_pppol2tpv3in6)) {
675 struct sockaddr_pppol2tpv3in6 *sp6 =
676 (struct sockaddr_pppol2tpv3in6 *) sp;
677 ver = 3;
678 fd = sp6->pppol2tp.fd;
679 tunnel_id = sp6->pppol2tp.s_tunnel;
680 peer_tunnel_id = sp6->pppol2tp.d_tunnel;
681 session_id = sp6->pppol2tp.s_session;
682 peer_session_id = sp6->pppol2tp.d_session;
683 } else {
684 error = -EINVAL;
685 goto end; /* bad socket address */
686 }
687
688 /* Don't bind if tunnel_id is 0 */
689 error = -EINVAL;
690 if (tunnel_id == 0)
691 goto end;
692
693 tunnel = l2tp_tunnel_get(sock_net(sk), tunnel_id);
694 if (tunnel)
695 drop_tunnel = true;
696
697 /* Special case: create tunnel context if session_id and
698 * peer_session_id is 0. Otherwise look up tunnel using supplied
699 * tunnel id.
700 */
701 if ((session_id == 0) && (peer_session_id == 0)) {
702 if (tunnel == NULL) {
703 struct l2tp_tunnel_cfg tcfg = {
704 .encap = L2TP_ENCAPTYPE_UDP,
705 .debug = 0,
706 };
707 error = l2tp_tunnel_create(sock_net(sk), fd, ver, tunnel_id, peer_tunnel_id, &tcfg, &tunnel);
708 if (error < 0)
709 goto end;
710 }
711 } else {
712 /* Error if we can't find the tunnel */
713 error = -ENOENT;
714 if (tunnel == NULL)
715 goto end;
716
717 /* Error if socket is not prepped */
718 if (tunnel->sock == NULL)
719 goto end;
720 }
721
722 if (tunnel->recv_payload_hook == NULL)
723 tunnel->recv_payload_hook = pppol2tp_recv_payload_hook;
724
725 if (tunnel->peer_tunnel_id == 0)
726 tunnel->peer_tunnel_id = peer_tunnel_id;
727
728 session = l2tp_session_get(sock_net(sk), tunnel, session_id);
729 if (session) {
730 drop_refcnt = true;
731 ps = l2tp_session_priv(session);
732
733 /* Using a pre-existing session is fine as long as it hasn't
734 * been connected yet.
735 */
736 mutex_lock(&ps->sk_lock);
737 if (rcu_dereference_protected(ps->sk,
738 lockdep_is_held(&ps->sk_lock))) {
739 mutex_unlock(&ps->sk_lock);
740 error = -EEXIST;
741 goto end;
742 }
743 } else {
744 /* Default MTU must allow space for UDP/L2TP/PPP headers */
745 cfg.mtu = 1500 - PPPOL2TP_HEADER_OVERHEAD;
746 cfg.mru = cfg.mtu;
747
748 session = l2tp_session_create(sizeof(struct pppol2tp_session),
749 tunnel, session_id,
750 peer_session_id, &cfg);
751 if (IS_ERR(session)) {
752 error = PTR_ERR(session);
753 goto end;
754 }
755
756 pppol2tp_session_init(session);
757 ps = l2tp_session_priv(session);
758 l2tp_session_inc_refcount(session);
759
760 mutex_lock(&ps->sk_lock);
761 error = l2tp_session_register(session, tunnel);
762 if (error < 0) {
763 mutex_unlock(&ps->sk_lock);
764 kfree(session);
765 goto end;
766 }
767 drop_refcnt = true;
768 }
769
770 /* Special case: if source & dest session_id == 0x0000, this
771 * socket is being created to manage the tunnel. Just set up
772 * the internal context for use by ioctl() and sockopt()
773 * handlers.
774 */
775 if ((session->session_id == 0) &&
776 (session->peer_session_id == 0)) {
777 error = 0;
778 goto out_no_ppp;
779 }
780
781 /* The only header we need to worry about is the L2TP
782 * header. This size is different depending on whether
783 * sequence numbers are enabled for the data channel.
784 */
785 po->chan.hdrlen = PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
786
787 po->chan.private = sk;
788 po->chan.ops = &pppol2tp_chan_ops;
789 po->chan.mtu = session->mtu;
790
791 error = ppp_register_net_channel(sock_net(sk), &po->chan);
792 if (error) {
793 mutex_unlock(&ps->sk_lock);
794 goto end;
795 }
796
797 out_no_ppp:
798 /* This is how we get the session context from the socket. */
799 sk->sk_user_data = session;
800 rcu_assign_pointer(ps->sk, sk);
801 mutex_unlock(&ps->sk_lock);
802
803 /* Keep the reference we've grabbed on the session: sk doesn't expect
804 * the session to disappear. pppol2tp_session_destruct() is responsible
805 * for dropping it.
806 */
807 drop_refcnt = false;
808
809 sk->sk_state = PPPOX_CONNECTED;
810 l2tp_info(session, L2TP_MSG_CONTROL, "%s: created\n",
811 session->name);
812
813 end:
814 if (drop_refcnt)
815 l2tp_session_dec_refcount(session);
816 if (drop_tunnel)
817 l2tp_tunnel_dec_refcount(tunnel);
818 release_sock(sk);
819
820 return error;
821 }
822
823 #ifdef CONFIG_L2TP_V3
824
825 /* Called when creating sessions via the netlink interface. */
826 static int pppol2tp_session_create(struct net *net, struct l2tp_tunnel *tunnel,
827 u32 session_id, u32 peer_session_id,
828 struct l2tp_session_cfg *cfg)
829 {
830 int error;
831 struct l2tp_session *session;
832
833 /* Error if tunnel socket is not prepped */
834 if (!tunnel->sock) {
835 error = -ENOENT;
836 goto err;
837 }
838
839 /* Default MTU values. */
840 if (cfg->mtu == 0)
841 cfg->mtu = 1500 - PPPOL2TP_HEADER_OVERHEAD;
842 if (cfg->mru == 0)
843 cfg->mru = cfg->mtu;
844
845 /* Allocate and initialize a new session context. */
846 session = l2tp_session_create(sizeof(struct pppol2tp_session),
847 tunnel, session_id,
848 peer_session_id, cfg);
849 if (IS_ERR(session)) {
850 error = PTR_ERR(session);
851 goto err;
852 }
853
854 pppol2tp_session_init(session);
855
856 error = l2tp_session_register(session, tunnel);
857 if (error < 0)
858 goto err_sess;
859
860 return 0;
861
862 err_sess:
863 kfree(session);
864 err:
865 return error;
866 }
867
868 #endif /* CONFIG_L2TP_V3 */
869
870 /* getname() support.
871 */
872 static int pppol2tp_getname(struct socket *sock, struct sockaddr *uaddr,
873 int peer)
874 {
875 int len = 0;
876 int error = 0;
877 struct l2tp_session *session;
878 struct l2tp_tunnel *tunnel;
879 struct sock *sk = sock->sk;
880 struct inet_sock *inet;
881 struct pppol2tp_session *pls;
882
883 error = -ENOTCONN;
884 if (sk == NULL)
885 goto end;
886 if (!(sk->sk_state & PPPOX_CONNECTED))
887 goto end;
888
889 error = -EBADF;
890 session = pppol2tp_sock_to_session(sk);
891 if (session == NULL)
892 goto end;
893
894 pls = l2tp_session_priv(session);
895 tunnel = session->tunnel;
896
897 inet = inet_sk(tunnel->sock);
898 if ((tunnel->version == 2) && (tunnel->sock->sk_family == AF_INET)) {
899 struct sockaddr_pppol2tp sp;
900 len = sizeof(sp);
901 memset(&sp, 0, len);
902 sp.sa_family = AF_PPPOX;
903 sp.sa_protocol = PX_PROTO_OL2TP;
904 sp.pppol2tp.fd = tunnel->fd;
905 sp.pppol2tp.pid = pls->owner;
906 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
907 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
908 sp.pppol2tp.s_session = session->session_id;
909 sp.pppol2tp.d_session = session->peer_session_id;
910 sp.pppol2tp.addr.sin_family = AF_INET;
911 sp.pppol2tp.addr.sin_port = inet->inet_dport;
912 sp.pppol2tp.addr.sin_addr.s_addr = inet->inet_daddr;
913 memcpy(uaddr, &sp, len);
914 #if IS_ENABLED(CONFIG_IPV6)
915 } else if ((tunnel->version == 2) &&
916 (tunnel->sock->sk_family == AF_INET6)) {
917 struct sockaddr_pppol2tpin6 sp;
918
919 len = sizeof(sp);
920 memset(&sp, 0, len);
921 sp.sa_family = AF_PPPOX;
922 sp.sa_protocol = PX_PROTO_OL2TP;
923 sp.pppol2tp.fd = tunnel->fd;
924 sp.pppol2tp.pid = pls->owner;
925 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
926 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
927 sp.pppol2tp.s_session = session->session_id;
928 sp.pppol2tp.d_session = session->peer_session_id;
929 sp.pppol2tp.addr.sin6_family = AF_INET6;
930 sp.pppol2tp.addr.sin6_port = inet->inet_dport;
931 memcpy(&sp.pppol2tp.addr.sin6_addr, &tunnel->sock->sk_v6_daddr,
932 sizeof(tunnel->sock->sk_v6_daddr));
933 memcpy(uaddr, &sp, len);
934 } else if ((tunnel->version == 3) &&
935 (tunnel->sock->sk_family == AF_INET6)) {
936 struct sockaddr_pppol2tpv3in6 sp;
937
938 len = sizeof(sp);
939 memset(&sp, 0, len);
940 sp.sa_family = AF_PPPOX;
941 sp.sa_protocol = PX_PROTO_OL2TP;
942 sp.pppol2tp.fd = tunnel->fd;
943 sp.pppol2tp.pid = pls->owner;
944 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
945 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
946 sp.pppol2tp.s_session = session->session_id;
947 sp.pppol2tp.d_session = session->peer_session_id;
948 sp.pppol2tp.addr.sin6_family = AF_INET6;
949 sp.pppol2tp.addr.sin6_port = inet->inet_dport;
950 memcpy(&sp.pppol2tp.addr.sin6_addr, &tunnel->sock->sk_v6_daddr,
951 sizeof(tunnel->sock->sk_v6_daddr));
952 memcpy(uaddr, &sp, len);
953 #endif
954 } else if (tunnel->version == 3) {
955 struct sockaddr_pppol2tpv3 sp;
956 len = sizeof(sp);
957 memset(&sp, 0, len);
958 sp.sa_family = AF_PPPOX;
959 sp.sa_protocol = PX_PROTO_OL2TP;
960 sp.pppol2tp.fd = tunnel->fd;
961 sp.pppol2tp.pid = pls->owner;
962 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
963 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
964 sp.pppol2tp.s_session = session->session_id;
965 sp.pppol2tp.d_session = session->peer_session_id;
966 sp.pppol2tp.addr.sin_family = AF_INET;
967 sp.pppol2tp.addr.sin_port = inet->inet_dport;
968 sp.pppol2tp.addr.sin_addr.s_addr = inet->inet_daddr;
969 memcpy(uaddr, &sp, len);
970 }
971
972 error = len;
973
974 sock_put(sk);
975 end:
976 return error;
977 }
978
979 /****************************************************************************
980 * ioctl() handlers.
981 *
982 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
983 * sockets. However, in order to control kernel tunnel features, we allow
984 * userspace to create a special "tunnel" PPPoX socket which is used for
985 * control only. Tunnel PPPoX sockets have session_id == 0 and simply allow
986 * the user application to issue L2TP setsockopt(), getsockopt() and ioctl()
987 * calls.
988 ****************************************************************************/
989
990 static void pppol2tp_copy_stats(struct pppol2tp_ioc_stats *dest,
991 struct l2tp_stats *stats)
992 {
993 dest->tx_packets = atomic_long_read(&stats->tx_packets);
994 dest->tx_bytes = atomic_long_read(&stats->tx_bytes);
995 dest->tx_errors = atomic_long_read(&stats->tx_errors);
996 dest->rx_packets = atomic_long_read(&stats->rx_packets);
997 dest->rx_bytes = atomic_long_read(&stats->rx_bytes);
998 dest->rx_seq_discards = atomic_long_read(&stats->rx_seq_discards);
999 dest->rx_oos_packets = atomic_long_read(&stats->rx_oos_packets);
1000 dest->rx_errors = atomic_long_read(&stats->rx_errors);
1001 }
1002
1003 /* Session ioctl helper.
1004 */
1005 static int pppol2tp_session_ioctl(struct l2tp_session *session,
1006 unsigned int cmd, unsigned long arg)
1007 {
1008 struct ifreq ifr;
1009 int err = 0;
1010 struct sock *sk;
1011 int val = (int) arg;
1012 struct pppol2tp_session *ps = l2tp_session_priv(session);
1013 struct l2tp_tunnel *tunnel = session->tunnel;
1014 struct pppol2tp_ioc_stats stats;
1015
1016 l2tp_dbg(session, L2TP_MSG_CONTROL,
1017 "%s: pppol2tp_session_ioctl(cmd=%#x, arg=%#lx)\n",
1018 session->name, cmd, arg);
1019
1020 sk = pppol2tp_session_get_sock(session);
1021 if (!sk)
1022 return -EBADR;
1023
1024 switch (cmd) {
1025 case SIOCGIFMTU:
1026 err = -ENXIO;
1027 if (!(sk->sk_state & PPPOX_CONNECTED))
1028 break;
1029
1030 err = -EFAULT;
1031 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq)))
1032 break;
1033 ifr.ifr_mtu = session->mtu;
1034 if (copy_to_user((void __user *) arg, &ifr, sizeof(struct ifreq)))
1035 break;
1036
1037 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get mtu=%d\n",
1038 session->name, session->mtu);
1039 err = 0;
1040 break;
1041
1042 case SIOCSIFMTU:
1043 err = -ENXIO;
1044 if (!(sk->sk_state & PPPOX_CONNECTED))
1045 break;
1046
1047 err = -EFAULT;
1048 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq)))
1049 break;
1050
1051 session->mtu = ifr.ifr_mtu;
1052
1053 l2tp_info(session, L2TP_MSG_CONTROL, "%s: set mtu=%d\n",
1054 session->name, session->mtu);
1055 err = 0;
1056 break;
1057
1058 case PPPIOCGMRU:
1059 err = -ENXIO;
1060 if (!(sk->sk_state & PPPOX_CONNECTED))
1061 break;
1062
1063 err = -EFAULT;
1064 if (put_user(session->mru, (int __user *) arg))
1065 break;
1066
1067 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get mru=%d\n",
1068 session->name, session->mru);
1069 err = 0;
1070 break;
1071
1072 case PPPIOCSMRU:
1073 err = -ENXIO;
1074 if (!(sk->sk_state & PPPOX_CONNECTED))
1075 break;
1076
1077 err = -EFAULT;
1078 if (get_user(val, (int __user *) arg))
1079 break;
1080
1081 session->mru = val;
1082 l2tp_info(session, L2TP_MSG_CONTROL, "%s: set mru=%d\n",
1083 session->name, session->mru);
1084 err = 0;
1085 break;
1086
1087 case PPPIOCGFLAGS:
1088 err = -EFAULT;
1089 if (put_user(ps->flags, (int __user *) arg))
1090 break;
1091
1092 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get flags=%d\n",
1093 session->name, ps->flags);
1094 err = 0;
1095 break;
1096
1097 case PPPIOCSFLAGS:
1098 err = -EFAULT;
1099 if (get_user(val, (int __user *) arg))
1100 break;
1101 ps->flags = val;
1102 l2tp_info(session, L2TP_MSG_CONTROL, "%s: set flags=%d\n",
1103 session->name, ps->flags);
1104 err = 0;
1105 break;
1106
1107 case PPPIOCGL2TPSTATS:
1108 err = -ENXIO;
1109 if (!(sk->sk_state & PPPOX_CONNECTED))
1110 break;
1111
1112 memset(&stats, 0, sizeof(stats));
1113 stats.tunnel_id = tunnel->tunnel_id;
1114 stats.session_id = session->session_id;
1115 pppol2tp_copy_stats(&stats, &session->stats);
1116 if (copy_to_user((void __user *) arg, &stats,
1117 sizeof(stats)))
1118 break;
1119 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get L2TP stats\n",
1120 session->name);
1121 err = 0;
1122 break;
1123
1124 default:
1125 err = -ENOSYS;
1126 break;
1127 }
1128
1129 sock_put(sk);
1130
1131 return err;
1132 }
1133
1134 /* Tunnel ioctl helper.
1135 *
1136 * Note the special handling for PPPIOCGL2TPSTATS below. If the ioctl data
1137 * specifies a session_id, the session ioctl handler is called. This allows an
1138 * application to retrieve session stats via a tunnel socket.
1139 */
1140 static int pppol2tp_tunnel_ioctl(struct l2tp_tunnel *tunnel,
1141 unsigned int cmd, unsigned long arg)
1142 {
1143 int err = 0;
1144 struct sock *sk;
1145 struct pppol2tp_ioc_stats stats;
1146
1147 l2tp_dbg(tunnel, L2TP_MSG_CONTROL,
1148 "%s: pppol2tp_tunnel_ioctl(cmd=%#x, arg=%#lx)\n",
1149 tunnel->name, cmd, arg);
1150
1151 sk = tunnel->sock;
1152 sock_hold(sk);
1153
1154 switch (cmd) {
1155 case PPPIOCGL2TPSTATS:
1156 err = -ENXIO;
1157 if (!(sk->sk_state & PPPOX_CONNECTED))
1158 break;
1159
1160 if (copy_from_user(&stats, (void __user *) arg,
1161 sizeof(stats))) {
1162 err = -EFAULT;
1163 break;
1164 }
1165 if (stats.session_id != 0) {
1166 /* resend to session ioctl handler */
1167 struct l2tp_session *session =
1168 l2tp_session_get(sock_net(sk), tunnel,
1169 stats.session_id);
1170
1171 if (session) {
1172 err = pppol2tp_session_ioctl(session, cmd,
1173 arg);
1174 l2tp_session_dec_refcount(session);
1175 } else {
1176 err = -EBADR;
1177 }
1178 break;
1179 }
1180 #ifdef CONFIG_XFRM
1181 stats.using_ipsec = (sk->sk_policy[0] || sk->sk_policy[1]) ? 1 : 0;
1182 #endif
1183 pppol2tp_copy_stats(&stats, &tunnel->stats);
1184 if (copy_to_user((void __user *) arg, &stats, sizeof(stats))) {
1185 err = -EFAULT;
1186 break;
1187 }
1188 l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: get L2TP stats\n",
1189 tunnel->name);
1190 err = 0;
1191 break;
1192
1193 default:
1194 err = -ENOSYS;
1195 break;
1196 }
1197
1198 sock_put(sk);
1199
1200 return err;
1201 }
1202
1203 /* Main ioctl() handler.
1204 * Dispatch to tunnel or session helpers depending on the socket.
1205 */
1206 static int pppol2tp_ioctl(struct socket *sock, unsigned int cmd,
1207 unsigned long arg)
1208 {
1209 struct sock *sk = sock->sk;
1210 struct l2tp_session *session;
1211 struct l2tp_tunnel *tunnel;
1212 int err;
1213
1214 if (!sk)
1215 return 0;
1216
1217 err = -EBADF;
1218 if (sock_flag(sk, SOCK_DEAD) != 0)
1219 goto end;
1220
1221 err = -ENOTCONN;
1222 if ((sk->sk_user_data == NULL) ||
1223 (!(sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND))))
1224 goto end;
1225
1226 /* Get session context from the socket */
1227 err = -EBADF;
1228 session = pppol2tp_sock_to_session(sk);
1229 if (session == NULL)
1230 goto end;
1231
1232 /* Special case: if session's session_id is zero, treat ioctl as a
1233 * tunnel ioctl
1234 */
1235 if ((session->session_id == 0) &&
1236 (session->peer_session_id == 0)) {
1237 tunnel = session->tunnel;
1238 err = pppol2tp_tunnel_ioctl(tunnel, cmd, arg);
1239 goto end_put_sess;
1240 }
1241
1242 err = pppol2tp_session_ioctl(session, cmd, arg);
1243
1244 end_put_sess:
1245 sock_put(sk);
1246 end:
1247 return err;
1248 }
1249
1250 /*****************************************************************************
1251 * setsockopt() / getsockopt() support.
1252 *
1253 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
1254 * sockets. In order to control kernel tunnel features, we allow userspace to
1255 * create a special "tunnel" PPPoX socket which is used for control only.
1256 * Tunnel PPPoX sockets have session_id == 0 and simply allow the user
1257 * application to issue L2TP setsockopt(), getsockopt() and ioctl() calls.
1258 *****************************************************************************/
1259
1260 /* Tunnel setsockopt() helper.
1261 */
1262 static int pppol2tp_tunnel_setsockopt(struct sock *sk,
1263 struct l2tp_tunnel *tunnel,
1264 int optname, int val)
1265 {
1266 int err = 0;
1267
1268 switch (optname) {
1269 case PPPOL2TP_SO_DEBUG:
1270 tunnel->debug = val;
1271 l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: set debug=%x\n",
1272 tunnel->name, tunnel->debug);
1273 break;
1274
1275 default:
1276 err = -ENOPROTOOPT;
1277 break;
1278 }
1279
1280 return err;
1281 }
1282
1283 /* Session setsockopt helper.
1284 */
1285 static int pppol2tp_session_setsockopt(struct sock *sk,
1286 struct l2tp_session *session,
1287 int optname, int val)
1288 {
1289 int err = 0;
1290
1291 switch (optname) {
1292 case PPPOL2TP_SO_RECVSEQ:
1293 if ((val != 0) && (val != 1)) {
1294 err = -EINVAL;
1295 break;
1296 }
1297 session->recv_seq = !!val;
1298 l2tp_info(session, L2TP_MSG_CONTROL,
1299 "%s: set recv_seq=%d\n",
1300 session->name, session->recv_seq);
1301 break;
1302
1303 case PPPOL2TP_SO_SENDSEQ:
1304 if ((val != 0) && (val != 1)) {
1305 err = -EINVAL;
1306 break;
1307 }
1308 session->send_seq = !!val;
1309 {
1310 struct pppox_sock *po = pppox_sk(sk);
1311
1312 po->chan.hdrlen = val ? PPPOL2TP_L2TP_HDR_SIZE_SEQ :
1313 PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
1314 }
1315 l2tp_session_set_header_len(session, session->tunnel->version);
1316 l2tp_info(session, L2TP_MSG_CONTROL,
1317 "%s: set send_seq=%d\n",
1318 session->name, session->send_seq);
1319 break;
1320
1321 case PPPOL2TP_SO_LNSMODE:
1322 if ((val != 0) && (val != 1)) {
1323 err = -EINVAL;
1324 break;
1325 }
1326 session->lns_mode = !!val;
1327 l2tp_info(session, L2TP_MSG_CONTROL,
1328 "%s: set lns_mode=%d\n",
1329 session->name, session->lns_mode);
1330 break;
1331
1332 case PPPOL2TP_SO_DEBUG:
1333 session->debug = val;
1334 l2tp_info(session, L2TP_MSG_CONTROL, "%s: set debug=%x\n",
1335 session->name, session->debug);
1336 break;
1337
1338 case PPPOL2TP_SO_REORDERTO:
1339 session->reorder_timeout = msecs_to_jiffies(val);
1340 l2tp_info(session, L2TP_MSG_CONTROL,
1341 "%s: set reorder_timeout=%d\n",
1342 session->name, session->reorder_timeout);
1343 break;
1344
1345 default:
1346 err = -ENOPROTOOPT;
1347 break;
1348 }
1349
1350 return err;
1351 }
1352
1353 /* Main setsockopt() entry point.
1354 * Does API checks, then calls either the tunnel or session setsockopt
1355 * handler, according to whether the PPPoL2TP socket is a for a regular
1356 * session or the special tunnel type.
1357 */
1358 static int pppol2tp_setsockopt(struct socket *sock, int level, int optname,
1359 char __user *optval, unsigned int optlen)
1360 {
1361 struct sock *sk = sock->sk;
1362 struct l2tp_session *session;
1363 struct l2tp_tunnel *tunnel;
1364 int val;
1365 int err;
1366
1367 if (level != SOL_PPPOL2TP)
1368 return -EINVAL;
1369
1370 if (optlen < sizeof(int))
1371 return -EINVAL;
1372
1373 if (get_user(val, (int __user *)optval))
1374 return -EFAULT;
1375
1376 err = -ENOTCONN;
1377 if (sk->sk_user_data == NULL)
1378 goto end;
1379
1380 /* Get session context from the socket */
1381 err = -EBADF;
1382 session = pppol2tp_sock_to_session(sk);
1383 if (session == NULL)
1384 goto end;
1385
1386 /* Special case: if session_id == 0x0000, treat as operation on tunnel
1387 */
1388 if ((session->session_id == 0) &&
1389 (session->peer_session_id == 0)) {
1390 tunnel = session->tunnel;
1391 err = pppol2tp_tunnel_setsockopt(sk, tunnel, optname, val);
1392 } else {
1393 err = pppol2tp_session_setsockopt(sk, session, optname, val);
1394 }
1395
1396 sock_put(sk);
1397 end:
1398 return err;
1399 }
1400
1401 /* Tunnel getsockopt helper. Called with sock locked.
1402 */
1403 static int pppol2tp_tunnel_getsockopt(struct sock *sk,
1404 struct l2tp_tunnel *tunnel,
1405 int optname, int *val)
1406 {
1407 int err = 0;
1408
1409 switch (optname) {
1410 case PPPOL2TP_SO_DEBUG:
1411 *val = tunnel->debug;
1412 l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: get debug=%x\n",
1413 tunnel->name, tunnel->debug);
1414 break;
1415
1416 default:
1417 err = -ENOPROTOOPT;
1418 break;
1419 }
1420
1421 return err;
1422 }
1423
1424 /* Session getsockopt helper. Called with sock locked.
1425 */
1426 static int pppol2tp_session_getsockopt(struct sock *sk,
1427 struct l2tp_session *session,
1428 int optname, int *val)
1429 {
1430 int err = 0;
1431
1432 switch (optname) {
1433 case PPPOL2TP_SO_RECVSEQ:
1434 *val = session->recv_seq;
1435 l2tp_info(session, L2TP_MSG_CONTROL,
1436 "%s: get recv_seq=%d\n", session->name, *val);
1437 break;
1438
1439 case PPPOL2TP_SO_SENDSEQ:
1440 *val = session->send_seq;
1441 l2tp_info(session, L2TP_MSG_CONTROL,
1442 "%s: get send_seq=%d\n", session->name, *val);
1443 break;
1444
1445 case PPPOL2TP_SO_LNSMODE:
1446 *val = session->lns_mode;
1447 l2tp_info(session, L2TP_MSG_CONTROL,
1448 "%s: get lns_mode=%d\n", session->name, *val);
1449 break;
1450
1451 case PPPOL2TP_SO_DEBUG:
1452 *val = session->debug;
1453 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get debug=%d\n",
1454 session->name, *val);
1455 break;
1456
1457 case PPPOL2TP_SO_REORDERTO:
1458 *val = (int) jiffies_to_msecs(session->reorder_timeout);
1459 l2tp_info(session, L2TP_MSG_CONTROL,
1460 "%s: get reorder_timeout=%d\n", session->name, *val);
1461 break;
1462
1463 default:
1464 err = -ENOPROTOOPT;
1465 }
1466
1467 return err;
1468 }
1469
1470 /* Main getsockopt() entry point.
1471 * Does API checks, then calls either the tunnel or session getsockopt
1472 * handler, according to whether the PPPoX socket is a for a regular session
1473 * or the special tunnel type.
1474 */
1475 static int pppol2tp_getsockopt(struct socket *sock, int level, int optname,
1476 char __user *optval, int __user *optlen)
1477 {
1478 struct sock *sk = sock->sk;
1479 struct l2tp_session *session;
1480 struct l2tp_tunnel *tunnel;
1481 int val, len;
1482 int err;
1483
1484 if (level != SOL_PPPOL2TP)
1485 return -EINVAL;
1486
1487 if (get_user(len, optlen))
1488 return -EFAULT;
1489
1490 len = min_t(unsigned int, len, sizeof(int));
1491
1492 if (len < 0)
1493 return -EINVAL;
1494
1495 err = -ENOTCONN;
1496 if (sk->sk_user_data == NULL)
1497 goto end;
1498
1499 /* Get the session context */
1500 err = -EBADF;
1501 session = pppol2tp_sock_to_session(sk);
1502 if (session == NULL)
1503 goto end;
1504
1505 /* Special case: if session_id == 0x0000, treat as operation on tunnel */
1506 if ((session->session_id == 0) &&
1507 (session->peer_session_id == 0)) {
1508 tunnel = session->tunnel;
1509 err = pppol2tp_tunnel_getsockopt(sk, tunnel, optname, &val);
1510 if (err)
1511 goto end_put_sess;
1512 } else {
1513 err = pppol2tp_session_getsockopt(sk, session, optname, &val);
1514 if (err)
1515 goto end_put_sess;
1516 }
1517
1518 err = -EFAULT;
1519 if (put_user(len, optlen))
1520 goto end_put_sess;
1521
1522 if (copy_to_user((void __user *) optval, &val, len))
1523 goto end_put_sess;
1524
1525 err = 0;
1526
1527 end_put_sess:
1528 sock_put(sk);
1529 end:
1530 return err;
1531 }
1532
1533 /*****************************************************************************
1534 * /proc filesystem for debug
1535 * Since the original pppol2tp driver provided /proc/net/pppol2tp for
1536 * L2TPv2, we dump only L2TPv2 tunnels and sessions here.
1537 *****************************************************************************/
1538
1539 static unsigned int pppol2tp_net_id;
1540
1541 #ifdef CONFIG_PROC_FS
1542
1543 struct pppol2tp_seq_data {
1544 struct seq_net_private p;
1545 int tunnel_idx; /* current tunnel */
1546 int session_idx; /* index of session within current tunnel */
1547 struct l2tp_tunnel *tunnel;
1548 struct l2tp_session *session; /* NULL means get next tunnel */
1549 };
1550
1551 static void pppol2tp_next_tunnel(struct net *net, struct pppol2tp_seq_data *pd)
1552 {
1553 for (;;) {
1554 pd->tunnel = l2tp_tunnel_find_nth(net, pd->tunnel_idx);
1555 pd->tunnel_idx++;
1556
1557 if (pd->tunnel == NULL)
1558 break;
1559
1560 /* Ignore L2TPv3 tunnels */
1561 if (pd->tunnel->version < 3)
1562 break;
1563 }
1564 }
1565
1566 static void pppol2tp_next_session(struct net *net, struct pppol2tp_seq_data *pd)
1567 {
1568 pd->session = l2tp_session_get_nth(pd->tunnel, pd->session_idx);
1569 pd->session_idx++;
1570
1571 if (pd->session == NULL) {
1572 pd->session_idx = 0;
1573 pppol2tp_next_tunnel(net, pd);
1574 }
1575 }
1576
1577 static void *pppol2tp_seq_start(struct seq_file *m, loff_t *offs)
1578 {
1579 struct pppol2tp_seq_data *pd = SEQ_START_TOKEN;
1580 loff_t pos = *offs;
1581 struct net *net;
1582
1583 if (!pos)
1584 goto out;
1585
1586 BUG_ON(m->private == NULL);
1587 pd = m->private;
1588 net = seq_file_net(m);
1589
1590 if (pd->tunnel == NULL)
1591 pppol2tp_next_tunnel(net, pd);
1592 else
1593 pppol2tp_next_session(net, pd);
1594
1595 /* NULL tunnel and session indicates end of list */
1596 if ((pd->tunnel == NULL) && (pd->session == NULL))
1597 pd = NULL;
1598
1599 out:
1600 return pd;
1601 }
1602
1603 static void *pppol2tp_seq_next(struct seq_file *m, void *v, loff_t *pos)
1604 {
1605 (*pos)++;
1606 return NULL;
1607 }
1608
1609 static void pppol2tp_seq_stop(struct seq_file *p, void *v)
1610 {
1611 /* nothing to do */
1612 }
1613
1614 static void pppol2tp_seq_tunnel_show(struct seq_file *m, void *v)
1615 {
1616 struct l2tp_tunnel *tunnel = v;
1617
1618 seq_printf(m, "\nTUNNEL '%s', %c %d\n",
1619 tunnel->name,
1620 (tunnel == tunnel->sock->sk_user_data) ? 'Y' : 'N',
1621 refcount_read(&tunnel->ref_count) - 1);
1622 seq_printf(m, " %08x %ld/%ld/%ld %ld/%ld/%ld\n",
1623 tunnel->debug,
1624 atomic_long_read(&tunnel->stats.tx_packets),
1625 atomic_long_read(&tunnel->stats.tx_bytes),
1626 atomic_long_read(&tunnel->stats.tx_errors),
1627 atomic_long_read(&tunnel->stats.rx_packets),
1628 atomic_long_read(&tunnel->stats.rx_bytes),
1629 atomic_long_read(&tunnel->stats.rx_errors));
1630 }
1631
1632 static void pppol2tp_seq_session_show(struct seq_file *m, void *v)
1633 {
1634 struct l2tp_session *session = v;
1635 struct l2tp_tunnel *tunnel = session->tunnel;
1636 unsigned char state;
1637 char user_data_ok;
1638 struct sock *sk;
1639 u32 ip = 0;
1640 u16 port = 0;
1641
1642 if (tunnel->sock) {
1643 struct inet_sock *inet = inet_sk(tunnel->sock);
1644 ip = ntohl(inet->inet_saddr);
1645 port = ntohs(inet->inet_sport);
1646 }
1647
1648 sk = pppol2tp_session_get_sock(session);
1649 if (sk) {
1650 state = sk->sk_state;
1651 user_data_ok = (session == sk->sk_user_data) ? 'Y' : 'N';
1652 } else {
1653 state = 0;
1654 user_data_ok = 'N';
1655 }
1656
1657 seq_printf(m, " SESSION '%s' %08X/%d %04X/%04X -> "
1658 "%04X/%04X %d %c\n",
1659 session->name, ip, port,
1660 tunnel->tunnel_id,
1661 session->session_id,
1662 tunnel->peer_tunnel_id,
1663 session->peer_session_id,
1664 state, user_data_ok);
1665 seq_printf(m, " %d/%d/%c/%c/%s %08x %u\n",
1666 session->mtu, session->mru,
1667 session->recv_seq ? 'R' : '-',
1668 session->send_seq ? 'S' : '-',
1669 session->lns_mode ? "LNS" : "LAC",
1670 session->debug,
1671 jiffies_to_msecs(session->reorder_timeout));
1672 seq_printf(m, " %hu/%hu %ld/%ld/%ld %ld/%ld/%ld\n",
1673 session->nr, session->ns,
1674 atomic_long_read(&session->stats.tx_packets),
1675 atomic_long_read(&session->stats.tx_bytes),
1676 atomic_long_read(&session->stats.tx_errors),
1677 atomic_long_read(&session->stats.rx_packets),
1678 atomic_long_read(&session->stats.rx_bytes),
1679 atomic_long_read(&session->stats.rx_errors));
1680
1681 if (sk) {
1682 struct pppox_sock *po = pppox_sk(sk);
1683
1684 seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan));
1685 sock_put(sk);
1686 }
1687 }
1688
1689 static int pppol2tp_seq_show(struct seq_file *m, void *v)
1690 {
1691 struct pppol2tp_seq_data *pd = v;
1692
1693 /* display header on line 1 */
1694 if (v == SEQ_START_TOKEN) {
1695 seq_puts(m, "PPPoL2TP driver info, " PPPOL2TP_DRV_VERSION "\n");
1696 seq_puts(m, "TUNNEL name, user-data-ok session-count\n");
1697 seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
1698 seq_puts(m, " SESSION name, addr/port src-tid/sid "
1699 "dest-tid/sid state user-data-ok\n");
1700 seq_puts(m, " mtu/mru/rcvseq/sendseq/lns debug reorderto\n");
1701 seq_puts(m, " nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
1702 goto out;
1703 }
1704
1705 /* Show the tunnel or session context.
1706 */
1707 if (!pd->session) {
1708 pppol2tp_seq_tunnel_show(m, pd->tunnel);
1709 } else {
1710 pppol2tp_seq_session_show(m, pd->session);
1711 l2tp_session_dec_refcount(pd->session);
1712 }
1713
1714 out:
1715 return 0;
1716 }
1717
1718 static const struct seq_operations pppol2tp_seq_ops = {
1719 .start = pppol2tp_seq_start,
1720 .next = pppol2tp_seq_next,
1721 .stop = pppol2tp_seq_stop,
1722 .show = pppol2tp_seq_show,
1723 };
1724
1725 /* Called when our /proc file is opened. We allocate data for use when
1726 * iterating our tunnel / session contexts and store it in the private
1727 * data of the seq_file.
1728 */
1729 static int pppol2tp_proc_open(struct inode *inode, struct file *file)
1730 {
1731 return seq_open_net(inode, file, &pppol2tp_seq_ops,
1732 sizeof(struct pppol2tp_seq_data));
1733 }
1734
1735 static const struct file_operations pppol2tp_proc_fops = {
1736 .open = pppol2tp_proc_open,
1737 .read = seq_read,
1738 .llseek = seq_lseek,
1739 .release = seq_release_net,
1740 };
1741
1742 #endif /* CONFIG_PROC_FS */
1743
1744 /*****************************************************************************
1745 * Network namespace
1746 *****************************************************************************/
1747
1748 static __net_init int pppol2tp_init_net(struct net *net)
1749 {
1750 struct proc_dir_entry *pde;
1751 int err = 0;
1752
1753 pde = proc_create("pppol2tp", S_IRUGO, net->proc_net,
1754 &pppol2tp_proc_fops);
1755 if (!pde) {
1756 err = -ENOMEM;
1757 goto out;
1758 }
1759
1760 out:
1761 return err;
1762 }
1763
1764 static __net_exit void pppol2tp_exit_net(struct net *net)
1765 {
1766 remove_proc_entry("pppol2tp", net->proc_net);
1767 }
1768
1769 static struct pernet_operations pppol2tp_net_ops = {
1770 .init = pppol2tp_init_net,
1771 .exit = pppol2tp_exit_net,
1772 .id = &pppol2tp_net_id,
1773 .async = true,
1774 };
1775
1776 /*****************************************************************************
1777 * Init and cleanup
1778 *****************************************************************************/
1779
1780 static const struct proto_ops pppol2tp_ops = {
1781 .family = AF_PPPOX,
1782 .owner = THIS_MODULE,
1783 .release = pppol2tp_release,
1784 .bind = sock_no_bind,
1785 .connect = pppol2tp_connect,
1786 .socketpair = sock_no_socketpair,
1787 .accept = sock_no_accept,
1788 .getname = pppol2tp_getname,
1789 .poll = datagram_poll,
1790 .listen = sock_no_listen,
1791 .shutdown = sock_no_shutdown,
1792 .setsockopt = pppol2tp_setsockopt,
1793 .getsockopt = pppol2tp_getsockopt,
1794 .sendmsg = pppol2tp_sendmsg,
1795 .recvmsg = pppol2tp_recvmsg,
1796 .mmap = sock_no_mmap,
1797 .ioctl = pppox_ioctl,
1798 };
1799
1800 static const struct pppox_proto pppol2tp_proto = {
1801 .create = pppol2tp_create,
1802 .ioctl = pppol2tp_ioctl,
1803 .owner = THIS_MODULE,
1804 };
1805
1806 #ifdef CONFIG_L2TP_V3
1807
1808 static const struct l2tp_nl_cmd_ops pppol2tp_nl_cmd_ops = {
1809 .session_create = pppol2tp_session_create,
1810 .session_delete = l2tp_session_delete,
1811 };
1812
1813 #endif /* CONFIG_L2TP_V3 */
1814
1815 static int __init pppol2tp_init(void)
1816 {
1817 int err;
1818
1819 err = register_pernet_device(&pppol2tp_net_ops);
1820 if (err)
1821 goto out;
1822
1823 err = proto_register(&pppol2tp_sk_proto, 0);
1824 if (err)
1825 goto out_unregister_pppol2tp_pernet;
1826
1827 err = register_pppox_proto(PX_PROTO_OL2TP, &pppol2tp_proto);
1828 if (err)
1829 goto out_unregister_pppol2tp_proto;
1830
1831 #ifdef CONFIG_L2TP_V3
1832 err = l2tp_nl_register_ops(L2TP_PWTYPE_PPP, &pppol2tp_nl_cmd_ops);
1833 if (err)
1834 goto out_unregister_pppox;
1835 #endif
1836
1837 pr_info("PPPoL2TP kernel driver, %s\n", PPPOL2TP_DRV_VERSION);
1838
1839 out:
1840 return err;
1841
1842 #ifdef CONFIG_L2TP_V3
1843 out_unregister_pppox:
1844 unregister_pppox_proto(PX_PROTO_OL2TP);
1845 #endif
1846 out_unregister_pppol2tp_proto:
1847 proto_unregister(&pppol2tp_sk_proto);
1848 out_unregister_pppol2tp_pernet:
1849 unregister_pernet_device(&pppol2tp_net_ops);
1850 goto out;
1851 }
1852
1853 static void __exit pppol2tp_exit(void)
1854 {
1855 #ifdef CONFIG_L2TP_V3
1856 l2tp_nl_unregister_ops(L2TP_PWTYPE_PPP);
1857 #endif
1858 unregister_pppox_proto(PX_PROTO_OL2TP);
1859 proto_unregister(&pppol2tp_sk_proto);
1860 unregister_pernet_device(&pppol2tp_net_ops);
1861 }
1862
1863 module_init(pppol2tp_init);
1864 module_exit(pppol2tp_exit);
1865
1866 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
1867 MODULE_DESCRIPTION("PPP over L2TP over UDP");
1868 MODULE_LICENSE("GPL");
1869 MODULE_VERSION(PPPOL2TP_DRV_VERSION);
1870 MODULE_ALIAS_NET_PF_PROTO(PF_PPPOX, PX_PROTO_OL2TP);
1871 MODULE_ALIAS_L2TP_PWTYPE(7);
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