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Merge tag 'platform-drivers-x86-v4.16-7' of git://git.infradead.org/linux-platform...
[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 *usockaddr_len, 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 *usockaddr_len = len;
965 error = 0;
966
967 sock_put(sk);
968 end:
969 return error;
970 }
971
972 /****************************************************************************
973 * ioctl() handlers.
974 *
975 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
976 * sockets. However, in order to control kernel tunnel features, we allow
977 * userspace to create a special "tunnel" PPPoX socket which is used for
978 * control only. Tunnel PPPoX sockets have session_id == 0 and simply allow
979 * the user application to issue L2TP setsockopt(), getsockopt() and ioctl()
980 * calls.
981 ****************************************************************************/
982
983 static void pppol2tp_copy_stats(struct pppol2tp_ioc_stats *dest,
984 struct l2tp_stats *stats)
985 {
986 dest->tx_packets = atomic_long_read(&stats->tx_packets);
987 dest->tx_bytes = atomic_long_read(&stats->tx_bytes);
988 dest->tx_errors = atomic_long_read(&stats->tx_errors);
989 dest->rx_packets = atomic_long_read(&stats->rx_packets);
990 dest->rx_bytes = atomic_long_read(&stats->rx_bytes);
991 dest->rx_seq_discards = atomic_long_read(&stats->rx_seq_discards);
992 dest->rx_oos_packets = atomic_long_read(&stats->rx_oos_packets);
993 dest->rx_errors = atomic_long_read(&stats->rx_errors);
994 }
995
996 /* Session ioctl helper.
997 */
998 static int pppol2tp_session_ioctl(struct l2tp_session *session,
999 unsigned int cmd, unsigned long arg)
1000 {
1001 struct ifreq ifr;
1002 int err = 0;
1003 struct sock *sk;
1004 int val = (int) arg;
1005 struct pppol2tp_session *ps = l2tp_session_priv(session);
1006 struct l2tp_tunnel *tunnel = session->tunnel;
1007 struct pppol2tp_ioc_stats stats;
1008
1009 l2tp_dbg(session, L2TP_MSG_CONTROL,
1010 "%s: pppol2tp_session_ioctl(cmd=%#x, arg=%#lx)\n",
1011 session->name, cmd, arg);
1012
1013 sk = pppol2tp_session_get_sock(session);
1014 if (!sk)
1015 return -EBADR;
1016
1017 switch (cmd) {
1018 case SIOCGIFMTU:
1019 err = -ENXIO;
1020 if (!(sk->sk_state & PPPOX_CONNECTED))
1021 break;
1022
1023 err = -EFAULT;
1024 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq)))
1025 break;
1026 ifr.ifr_mtu = session->mtu;
1027 if (copy_to_user((void __user *) arg, &ifr, sizeof(struct ifreq)))
1028 break;
1029
1030 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get mtu=%d\n",
1031 session->name, session->mtu);
1032 err = 0;
1033 break;
1034
1035 case SIOCSIFMTU:
1036 err = -ENXIO;
1037 if (!(sk->sk_state & PPPOX_CONNECTED))
1038 break;
1039
1040 err = -EFAULT;
1041 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq)))
1042 break;
1043
1044 session->mtu = ifr.ifr_mtu;
1045
1046 l2tp_info(session, L2TP_MSG_CONTROL, "%s: set mtu=%d\n",
1047 session->name, session->mtu);
1048 err = 0;
1049 break;
1050
1051 case PPPIOCGMRU:
1052 err = -ENXIO;
1053 if (!(sk->sk_state & PPPOX_CONNECTED))
1054 break;
1055
1056 err = -EFAULT;
1057 if (put_user(session->mru, (int __user *) arg))
1058 break;
1059
1060 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get mru=%d\n",
1061 session->name, session->mru);
1062 err = 0;
1063 break;
1064
1065 case PPPIOCSMRU:
1066 err = -ENXIO;
1067 if (!(sk->sk_state & PPPOX_CONNECTED))
1068 break;
1069
1070 err = -EFAULT;
1071 if (get_user(val, (int __user *) arg))
1072 break;
1073
1074 session->mru = val;
1075 l2tp_info(session, L2TP_MSG_CONTROL, "%s: set mru=%d\n",
1076 session->name, session->mru);
1077 err = 0;
1078 break;
1079
1080 case PPPIOCGFLAGS:
1081 err = -EFAULT;
1082 if (put_user(ps->flags, (int __user *) arg))
1083 break;
1084
1085 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get flags=%d\n",
1086 session->name, ps->flags);
1087 err = 0;
1088 break;
1089
1090 case PPPIOCSFLAGS:
1091 err = -EFAULT;
1092 if (get_user(val, (int __user *) arg))
1093 break;
1094 ps->flags = val;
1095 l2tp_info(session, L2TP_MSG_CONTROL, "%s: set flags=%d\n",
1096 session->name, ps->flags);
1097 err = 0;
1098 break;
1099
1100 case PPPIOCGL2TPSTATS:
1101 err = -ENXIO;
1102 if (!(sk->sk_state & PPPOX_CONNECTED))
1103 break;
1104
1105 memset(&stats, 0, sizeof(stats));
1106 stats.tunnel_id = tunnel->tunnel_id;
1107 stats.session_id = session->session_id;
1108 pppol2tp_copy_stats(&stats, &session->stats);
1109 if (copy_to_user((void __user *) arg, &stats,
1110 sizeof(stats)))
1111 break;
1112 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get L2TP stats\n",
1113 session->name);
1114 err = 0;
1115 break;
1116
1117 default:
1118 err = -ENOSYS;
1119 break;
1120 }
1121
1122 sock_put(sk);
1123
1124 return err;
1125 }
1126
1127 /* Tunnel ioctl helper.
1128 *
1129 * Note the special handling for PPPIOCGL2TPSTATS below. If the ioctl data
1130 * specifies a session_id, the session ioctl handler is called. This allows an
1131 * application to retrieve session stats via a tunnel socket.
1132 */
1133 static int pppol2tp_tunnel_ioctl(struct l2tp_tunnel *tunnel,
1134 unsigned int cmd, unsigned long arg)
1135 {
1136 int err = 0;
1137 struct sock *sk;
1138 struct pppol2tp_ioc_stats stats;
1139
1140 l2tp_dbg(tunnel, L2TP_MSG_CONTROL,
1141 "%s: pppol2tp_tunnel_ioctl(cmd=%#x, arg=%#lx)\n",
1142 tunnel->name, cmd, arg);
1143
1144 sk = tunnel->sock;
1145 sock_hold(sk);
1146
1147 switch (cmd) {
1148 case PPPIOCGL2TPSTATS:
1149 err = -ENXIO;
1150 if (!(sk->sk_state & PPPOX_CONNECTED))
1151 break;
1152
1153 if (copy_from_user(&stats, (void __user *) arg,
1154 sizeof(stats))) {
1155 err = -EFAULT;
1156 break;
1157 }
1158 if (stats.session_id != 0) {
1159 /* resend to session ioctl handler */
1160 struct l2tp_session *session =
1161 l2tp_session_get(sock_net(sk), tunnel,
1162 stats.session_id);
1163
1164 if (session) {
1165 err = pppol2tp_session_ioctl(session, cmd,
1166 arg);
1167 l2tp_session_dec_refcount(session);
1168 } else {
1169 err = -EBADR;
1170 }
1171 break;
1172 }
1173 #ifdef CONFIG_XFRM
1174 stats.using_ipsec = (sk->sk_policy[0] || sk->sk_policy[1]) ? 1 : 0;
1175 #endif
1176 pppol2tp_copy_stats(&stats, &tunnel->stats);
1177 if (copy_to_user((void __user *) arg, &stats, sizeof(stats))) {
1178 err = -EFAULT;
1179 break;
1180 }
1181 l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: get L2TP stats\n",
1182 tunnel->name);
1183 err = 0;
1184 break;
1185
1186 default:
1187 err = -ENOSYS;
1188 break;
1189 }
1190
1191 sock_put(sk);
1192
1193 return err;
1194 }
1195
1196 /* Main ioctl() handler.
1197 * Dispatch to tunnel or session helpers depending on the socket.
1198 */
1199 static int pppol2tp_ioctl(struct socket *sock, unsigned int cmd,
1200 unsigned long arg)
1201 {
1202 struct sock *sk = sock->sk;
1203 struct l2tp_session *session;
1204 struct l2tp_tunnel *tunnel;
1205 int err;
1206
1207 if (!sk)
1208 return 0;
1209
1210 err = -EBADF;
1211 if (sock_flag(sk, SOCK_DEAD) != 0)
1212 goto end;
1213
1214 err = -ENOTCONN;
1215 if ((sk->sk_user_data == NULL) ||
1216 (!(sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND))))
1217 goto end;
1218
1219 /* Get session context from the socket */
1220 err = -EBADF;
1221 session = pppol2tp_sock_to_session(sk);
1222 if (session == NULL)
1223 goto end;
1224
1225 /* Special case: if session's session_id is zero, treat ioctl as a
1226 * tunnel ioctl
1227 */
1228 if ((session->session_id == 0) &&
1229 (session->peer_session_id == 0)) {
1230 tunnel = session->tunnel;
1231 err = pppol2tp_tunnel_ioctl(tunnel, cmd, arg);
1232 goto end_put_sess;
1233 }
1234
1235 err = pppol2tp_session_ioctl(session, cmd, arg);
1236
1237 end_put_sess:
1238 sock_put(sk);
1239 end:
1240 return err;
1241 }
1242
1243 /*****************************************************************************
1244 * setsockopt() / getsockopt() support.
1245 *
1246 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
1247 * sockets. In order to control kernel tunnel features, we allow userspace to
1248 * create a special "tunnel" PPPoX socket which is used for control only.
1249 * Tunnel PPPoX sockets have session_id == 0 and simply allow the user
1250 * application to issue L2TP setsockopt(), getsockopt() and ioctl() calls.
1251 *****************************************************************************/
1252
1253 /* Tunnel setsockopt() helper.
1254 */
1255 static int pppol2tp_tunnel_setsockopt(struct sock *sk,
1256 struct l2tp_tunnel *tunnel,
1257 int optname, int val)
1258 {
1259 int err = 0;
1260
1261 switch (optname) {
1262 case PPPOL2TP_SO_DEBUG:
1263 tunnel->debug = val;
1264 l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: set debug=%x\n",
1265 tunnel->name, tunnel->debug);
1266 break;
1267
1268 default:
1269 err = -ENOPROTOOPT;
1270 break;
1271 }
1272
1273 return err;
1274 }
1275
1276 /* Session setsockopt helper.
1277 */
1278 static int pppol2tp_session_setsockopt(struct sock *sk,
1279 struct l2tp_session *session,
1280 int optname, int val)
1281 {
1282 int err = 0;
1283
1284 switch (optname) {
1285 case PPPOL2TP_SO_RECVSEQ:
1286 if ((val != 0) && (val != 1)) {
1287 err = -EINVAL;
1288 break;
1289 }
1290 session->recv_seq = !!val;
1291 l2tp_info(session, L2TP_MSG_CONTROL,
1292 "%s: set recv_seq=%d\n",
1293 session->name, session->recv_seq);
1294 break;
1295
1296 case PPPOL2TP_SO_SENDSEQ:
1297 if ((val != 0) && (val != 1)) {
1298 err = -EINVAL;
1299 break;
1300 }
1301 session->send_seq = !!val;
1302 {
1303 struct pppox_sock *po = pppox_sk(sk);
1304
1305 po->chan.hdrlen = val ? PPPOL2TP_L2TP_HDR_SIZE_SEQ :
1306 PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
1307 }
1308 l2tp_session_set_header_len(session, session->tunnel->version);
1309 l2tp_info(session, L2TP_MSG_CONTROL,
1310 "%s: set send_seq=%d\n",
1311 session->name, session->send_seq);
1312 break;
1313
1314 case PPPOL2TP_SO_LNSMODE:
1315 if ((val != 0) && (val != 1)) {
1316 err = -EINVAL;
1317 break;
1318 }
1319 session->lns_mode = !!val;
1320 l2tp_info(session, L2TP_MSG_CONTROL,
1321 "%s: set lns_mode=%d\n",
1322 session->name, session->lns_mode);
1323 break;
1324
1325 case PPPOL2TP_SO_DEBUG:
1326 session->debug = val;
1327 l2tp_info(session, L2TP_MSG_CONTROL, "%s: set debug=%x\n",
1328 session->name, session->debug);
1329 break;
1330
1331 case PPPOL2TP_SO_REORDERTO:
1332 session->reorder_timeout = msecs_to_jiffies(val);
1333 l2tp_info(session, L2TP_MSG_CONTROL,
1334 "%s: set reorder_timeout=%d\n",
1335 session->name, session->reorder_timeout);
1336 break;
1337
1338 default:
1339 err = -ENOPROTOOPT;
1340 break;
1341 }
1342
1343 return err;
1344 }
1345
1346 /* Main setsockopt() entry point.
1347 * Does API checks, then calls either the tunnel or session setsockopt
1348 * handler, according to whether the PPPoL2TP socket is a for a regular
1349 * session or the special tunnel type.
1350 */
1351 static int pppol2tp_setsockopt(struct socket *sock, int level, int optname,
1352 char __user *optval, unsigned int optlen)
1353 {
1354 struct sock *sk = sock->sk;
1355 struct l2tp_session *session;
1356 struct l2tp_tunnel *tunnel;
1357 int val;
1358 int err;
1359
1360 if (level != SOL_PPPOL2TP)
1361 return -EINVAL;
1362
1363 if (optlen < sizeof(int))
1364 return -EINVAL;
1365
1366 if (get_user(val, (int __user *)optval))
1367 return -EFAULT;
1368
1369 err = -ENOTCONN;
1370 if (sk->sk_user_data == NULL)
1371 goto end;
1372
1373 /* Get session context from the socket */
1374 err = -EBADF;
1375 session = pppol2tp_sock_to_session(sk);
1376 if (session == NULL)
1377 goto end;
1378
1379 /* Special case: if session_id == 0x0000, treat as operation on tunnel
1380 */
1381 if ((session->session_id == 0) &&
1382 (session->peer_session_id == 0)) {
1383 tunnel = session->tunnel;
1384 err = pppol2tp_tunnel_setsockopt(sk, tunnel, optname, val);
1385 } else {
1386 err = pppol2tp_session_setsockopt(sk, session, optname, val);
1387 }
1388
1389 sock_put(sk);
1390 end:
1391 return err;
1392 }
1393
1394 /* Tunnel getsockopt helper. Called with sock locked.
1395 */
1396 static int pppol2tp_tunnel_getsockopt(struct sock *sk,
1397 struct l2tp_tunnel *tunnel,
1398 int optname, int *val)
1399 {
1400 int err = 0;
1401
1402 switch (optname) {
1403 case PPPOL2TP_SO_DEBUG:
1404 *val = tunnel->debug;
1405 l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: get debug=%x\n",
1406 tunnel->name, tunnel->debug);
1407 break;
1408
1409 default:
1410 err = -ENOPROTOOPT;
1411 break;
1412 }
1413
1414 return err;
1415 }
1416
1417 /* Session getsockopt helper. Called with sock locked.
1418 */
1419 static int pppol2tp_session_getsockopt(struct sock *sk,
1420 struct l2tp_session *session,
1421 int optname, int *val)
1422 {
1423 int err = 0;
1424
1425 switch (optname) {
1426 case PPPOL2TP_SO_RECVSEQ:
1427 *val = session->recv_seq;
1428 l2tp_info(session, L2TP_MSG_CONTROL,
1429 "%s: get recv_seq=%d\n", session->name, *val);
1430 break;
1431
1432 case PPPOL2TP_SO_SENDSEQ:
1433 *val = session->send_seq;
1434 l2tp_info(session, L2TP_MSG_CONTROL,
1435 "%s: get send_seq=%d\n", session->name, *val);
1436 break;
1437
1438 case PPPOL2TP_SO_LNSMODE:
1439 *val = session->lns_mode;
1440 l2tp_info(session, L2TP_MSG_CONTROL,
1441 "%s: get lns_mode=%d\n", session->name, *val);
1442 break;
1443
1444 case PPPOL2TP_SO_DEBUG:
1445 *val = session->debug;
1446 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get debug=%d\n",
1447 session->name, *val);
1448 break;
1449
1450 case PPPOL2TP_SO_REORDERTO:
1451 *val = (int) jiffies_to_msecs(session->reorder_timeout);
1452 l2tp_info(session, L2TP_MSG_CONTROL,
1453 "%s: get reorder_timeout=%d\n", session->name, *val);
1454 break;
1455
1456 default:
1457 err = -ENOPROTOOPT;
1458 }
1459
1460 return err;
1461 }
1462
1463 /* Main getsockopt() entry point.
1464 * Does API checks, then calls either the tunnel or session getsockopt
1465 * handler, according to whether the PPPoX socket is a for a regular session
1466 * or the special tunnel type.
1467 */
1468 static int pppol2tp_getsockopt(struct socket *sock, int level, int optname,
1469 char __user *optval, int __user *optlen)
1470 {
1471 struct sock *sk = sock->sk;
1472 struct l2tp_session *session;
1473 struct l2tp_tunnel *tunnel;
1474 int val, len;
1475 int err;
1476
1477 if (level != SOL_PPPOL2TP)
1478 return -EINVAL;
1479
1480 if (get_user(len, optlen))
1481 return -EFAULT;
1482
1483 len = min_t(unsigned int, len, sizeof(int));
1484
1485 if (len < 0)
1486 return -EINVAL;
1487
1488 err = -ENOTCONN;
1489 if (sk->sk_user_data == NULL)
1490 goto end;
1491
1492 /* Get the session context */
1493 err = -EBADF;
1494 session = pppol2tp_sock_to_session(sk);
1495 if (session == NULL)
1496 goto end;
1497
1498 /* Special case: if session_id == 0x0000, treat as operation on tunnel */
1499 if ((session->session_id == 0) &&
1500 (session->peer_session_id == 0)) {
1501 tunnel = session->tunnel;
1502 err = pppol2tp_tunnel_getsockopt(sk, tunnel, optname, &val);
1503 if (err)
1504 goto end_put_sess;
1505 } else {
1506 err = pppol2tp_session_getsockopt(sk, session, optname, &val);
1507 if (err)
1508 goto end_put_sess;
1509 }
1510
1511 err = -EFAULT;
1512 if (put_user(len, optlen))
1513 goto end_put_sess;
1514
1515 if (copy_to_user((void __user *) optval, &val, len))
1516 goto end_put_sess;
1517
1518 err = 0;
1519
1520 end_put_sess:
1521 sock_put(sk);
1522 end:
1523 return err;
1524 }
1525
1526 /*****************************************************************************
1527 * /proc filesystem for debug
1528 * Since the original pppol2tp driver provided /proc/net/pppol2tp for
1529 * L2TPv2, we dump only L2TPv2 tunnels and sessions here.
1530 *****************************************************************************/
1531
1532 static unsigned int pppol2tp_net_id;
1533
1534 #ifdef CONFIG_PROC_FS
1535
1536 struct pppol2tp_seq_data {
1537 struct seq_net_private p;
1538 int tunnel_idx; /* current tunnel */
1539 int session_idx; /* index of session within current tunnel */
1540 struct l2tp_tunnel *tunnel;
1541 struct l2tp_session *session; /* NULL means get next tunnel */
1542 };
1543
1544 static void pppol2tp_next_tunnel(struct net *net, struct pppol2tp_seq_data *pd)
1545 {
1546 for (;;) {
1547 pd->tunnel = l2tp_tunnel_find_nth(net, pd->tunnel_idx);
1548 pd->tunnel_idx++;
1549
1550 if (pd->tunnel == NULL)
1551 break;
1552
1553 /* Ignore L2TPv3 tunnels */
1554 if (pd->tunnel->version < 3)
1555 break;
1556 }
1557 }
1558
1559 static void pppol2tp_next_session(struct net *net, struct pppol2tp_seq_data *pd)
1560 {
1561 pd->session = l2tp_session_get_nth(pd->tunnel, pd->session_idx);
1562 pd->session_idx++;
1563
1564 if (pd->session == NULL) {
1565 pd->session_idx = 0;
1566 pppol2tp_next_tunnel(net, pd);
1567 }
1568 }
1569
1570 static void *pppol2tp_seq_start(struct seq_file *m, loff_t *offs)
1571 {
1572 struct pppol2tp_seq_data *pd = SEQ_START_TOKEN;
1573 loff_t pos = *offs;
1574 struct net *net;
1575
1576 if (!pos)
1577 goto out;
1578
1579 BUG_ON(m->private == NULL);
1580 pd = m->private;
1581 net = seq_file_net(m);
1582
1583 if (pd->tunnel == NULL)
1584 pppol2tp_next_tunnel(net, pd);
1585 else
1586 pppol2tp_next_session(net, pd);
1587
1588 /* NULL tunnel and session indicates end of list */
1589 if ((pd->tunnel == NULL) && (pd->session == NULL))
1590 pd = NULL;
1591
1592 out:
1593 return pd;
1594 }
1595
1596 static void *pppol2tp_seq_next(struct seq_file *m, void *v, loff_t *pos)
1597 {
1598 (*pos)++;
1599 return NULL;
1600 }
1601
1602 static void pppol2tp_seq_stop(struct seq_file *p, void *v)
1603 {
1604 /* nothing to do */
1605 }
1606
1607 static void pppol2tp_seq_tunnel_show(struct seq_file *m, void *v)
1608 {
1609 struct l2tp_tunnel *tunnel = v;
1610
1611 seq_printf(m, "\nTUNNEL '%s', %c %d\n",
1612 tunnel->name,
1613 (tunnel == tunnel->sock->sk_user_data) ? 'Y' : 'N',
1614 refcount_read(&tunnel->ref_count) - 1);
1615 seq_printf(m, " %08x %ld/%ld/%ld %ld/%ld/%ld\n",
1616 tunnel->debug,
1617 atomic_long_read(&tunnel->stats.tx_packets),
1618 atomic_long_read(&tunnel->stats.tx_bytes),
1619 atomic_long_read(&tunnel->stats.tx_errors),
1620 atomic_long_read(&tunnel->stats.rx_packets),
1621 atomic_long_read(&tunnel->stats.rx_bytes),
1622 atomic_long_read(&tunnel->stats.rx_errors));
1623 }
1624
1625 static void pppol2tp_seq_session_show(struct seq_file *m, void *v)
1626 {
1627 struct l2tp_session *session = v;
1628 struct l2tp_tunnel *tunnel = session->tunnel;
1629 unsigned char state;
1630 char user_data_ok;
1631 struct sock *sk;
1632 u32 ip = 0;
1633 u16 port = 0;
1634
1635 if (tunnel->sock) {
1636 struct inet_sock *inet = inet_sk(tunnel->sock);
1637 ip = ntohl(inet->inet_saddr);
1638 port = ntohs(inet->inet_sport);
1639 }
1640
1641 sk = pppol2tp_session_get_sock(session);
1642 if (sk) {
1643 state = sk->sk_state;
1644 user_data_ok = (session == sk->sk_user_data) ? 'Y' : 'N';
1645 } else {
1646 state = 0;
1647 user_data_ok = 'N';
1648 }
1649
1650 seq_printf(m, " SESSION '%s' %08X/%d %04X/%04X -> "
1651 "%04X/%04X %d %c\n",
1652 session->name, ip, port,
1653 tunnel->tunnel_id,
1654 session->session_id,
1655 tunnel->peer_tunnel_id,
1656 session->peer_session_id,
1657 state, user_data_ok);
1658 seq_printf(m, " %d/%d/%c/%c/%s %08x %u\n",
1659 session->mtu, session->mru,
1660 session->recv_seq ? 'R' : '-',
1661 session->send_seq ? 'S' : '-',
1662 session->lns_mode ? "LNS" : "LAC",
1663 session->debug,
1664 jiffies_to_msecs(session->reorder_timeout));
1665 seq_printf(m, " %hu/%hu %ld/%ld/%ld %ld/%ld/%ld\n",
1666 session->nr, session->ns,
1667 atomic_long_read(&session->stats.tx_packets),
1668 atomic_long_read(&session->stats.tx_bytes),
1669 atomic_long_read(&session->stats.tx_errors),
1670 atomic_long_read(&session->stats.rx_packets),
1671 atomic_long_read(&session->stats.rx_bytes),
1672 atomic_long_read(&session->stats.rx_errors));
1673
1674 if (sk) {
1675 struct pppox_sock *po = pppox_sk(sk);
1676
1677 seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan));
1678 sock_put(sk);
1679 }
1680 }
1681
1682 static int pppol2tp_seq_show(struct seq_file *m, void *v)
1683 {
1684 struct pppol2tp_seq_data *pd = v;
1685
1686 /* display header on line 1 */
1687 if (v == SEQ_START_TOKEN) {
1688 seq_puts(m, "PPPoL2TP driver info, " PPPOL2TP_DRV_VERSION "\n");
1689 seq_puts(m, "TUNNEL name, user-data-ok session-count\n");
1690 seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
1691 seq_puts(m, " SESSION name, addr/port src-tid/sid "
1692 "dest-tid/sid state user-data-ok\n");
1693 seq_puts(m, " mtu/mru/rcvseq/sendseq/lns debug reorderto\n");
1694 seq_puts(m, " nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
1695 goto out;
1696 }
1697
1698 /* Show the tunnel or session context.
1699 */
1700 if (!pd->session) {
1701 pppol2tp_seq_tunnel_show(m, pd->tunnel);
1702 } else {
1703 pppol2tp_seq_session_show(m, pd->session);
1704 l2tp_session_dec_refcount(pd->session);
1705 }
1706
1707 out:
1708 return 0;
1709 }
1710
1711 static const struct seq_operations pppol2tp_seq_ops = {
1712 .start = pppol2tp_seq_start,
1713 .next = pppol2tp_seq_next,
1714 .stop = pppol2tp_seq_stop,
1715 .show = pppol2tp_seq_show,
1716 };
1717
1718 /* Called when our /proc file is opened. We allocate data for use when
1719 * iterating our tunnel / session contexts and store it in the private
1720 * data of the seq_file.
1721 */
1722 static int pppol2tp_proc_open(struct inode *inode, struct file *file)
1723 {
1724 return seq_open_net(inode, file, &pppol2tp_seq_ops,
1725 sizeof(struct pppol2tp_seq_data));
1726 }
1727
1728 static const struct file_operations pppol2tp_proc_fops = {
1729 .open = pppol2tp_proc_open,
1730 .read = seq_read,
1731 .llseek = seq_lseek,
1732 .release = seq_release_net,
1733 };
1734
1735 #endif /* CONFIG_PROC_FS */
1736
1737 /*****************************************************************************
1738 * Network namespace
1739 *****************************************************************************/
1740
1741 static __net_init int pppol2tp_init_net(struct net *net)
1742 {
1743 struct proc_dir_entry *pde;
1744 int err = 0;
1745
1746 pde = proc_create("pppol2tp", S_IRUGO, net->proc_net,
1747 &pppol2tp_proc_fops);
1748 if (!pde) {
1749 err = -ENOMEM;
1750 goto out;
1751 }
1752
1753 out:
1754 return err;
1755 }
1756
1757 static __net_exit void pppol2tp_exit_net(struct net *net)
1758 {
1759 remove_proc_entry("pppol2tp", net->proc_net);
1760 }
1761
1762 static struct pernet_operations pppol2tp_net_ops = {
1763 .init = pppol2tp_init_net,
1764 .exit = pppol2tp_exit_net,
1765 .id = &pppol2tp_net_id,
1766 };
1767
1768 /*****************************************************************************
1769 * Init and cleanup
1770 *****************************************************************************/
1771
1772 static const struct proto_ops pppol2tp_ops = {
1773 .family = AF_PPPOX,
1774 .owner = THIS_MODULE,
1775 .release = pppol2tp_release,
1776 .bind = sock_no_bind,
1777 .connect = pppol2tp_connect,
1778 .socketpair = sock_no_socketpair,
1779 .accept = sock_no_accept,
1780 .getname = pppol2tp_getname,
1781 .poll = datagram_poll,
1782 .listen = sock_no_listen,
1783 .shutdown = sock_no_shutdown,
1784 .setsockopt = pppol2tp_setsockopt,
1785 .getsockopt = pppol2tp_getsockopt,
1786 .sendmsg = pppol2tp_sendmsg,
1787 .recvmsg = pppol2tp_recvmsg,
1788 .mmap = sock_no_mmap,
1789 .ioctl = pppox_ioctl,
1790 };
1791
1792 static const struct pppox_proto pppol2tp_proto = {
1793 .create = pppol2tp_create,
1794 .ioctl = pppol2tp_ioctl,
1795 .owner = THIS_MODULE,
1796 };
1797
1798 #ifdef CONFIG_L2TP_V3
1799
1800 static const struct l2tp_nl_cmd_ops pppol2tp_nl_cmd_ops = {
1801 .session_create = pppol2tp_session_create,
1802 .session_delete = l2tp_session_delete,
1803 };
1804
1805 #endif /* CONFIG_L2TP_V3 */
1806
1807 static int __init pppol2tp_init(void)
1808 {
1809 int err;
1810
1811 err = register_pernet_device(&pppol2tp_net_ops);
1812 if (err)
1813 goto out;
1814
1815 err = proto_register(&pppol2tp_sk_proto, 0);
1816 if (err)
1817 goto out_unregister_pppol2tp_pernet;
1818
1819 err = register_pppox_proto(PX_PROTO_OL2TP, &pppol2tp_proto);
1820 if (err)
1821 goto out_unregister_pppol2tp_proto;
1822
1823 #ifdef CONFIG_L2TP_V3
1824 err = l2tp_nl_register_ops(L2TP_PWTYPE_PPP, &pppol2tp_nl_cmd_ops);
1825 if (err)
1826 goto out_unregister_pppox;
1827 #endif
1828
1829 pr_info("PPPoL2TP kernel driver, %s\n", PPPOL2TP_DRV_VERSION);
1830
1831 out:
1832 return err;
1833
1834 #ifdef CONFIG_L2TP_V3
1835 out_unregister_pppox:
1836 unregister_pppox_proto(PX_PROTO_OL2TP);
1837 #endif
1838 out_unregister_pppol2tp_proto:
1839 proto_unregister(&pppol2tp_sk_proto);
1840 out_unregister_pppol2tp_pernet:
1841 unregister_pernet_device(&pppol2tp_net_ops);
1842 goto out;
1843 }
1844
1845 static void __exit pppol2tp_exit(void)
1846 {
1847 #ifdef CONFIG_L2TP_V3
1848 l2tp_nl_unregister_ops(L2TP_PWTYPE_PPP);
1849 #endif
1850 unregister_pppox_proto(PX_PROTO_OL2TP);
1851 proto_unregister(&pppol2tp_sk_proto);
1852 unregister_pernet_device(&pppol2tp_net_ops);
1853 }
1854
1855 module_init(pppol2tp_init);
1856 module_exit(pppol2tp_exit);
1857
1858 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
1859 MODULE_DESCRIPTION("PPP over L2TP over UDP");
1860 MODULE_LICENSE("GPL");
1861 MODULE_VERSION(PPPOL2TP_DRV_VERSION);
1862 MODULE_ALIAS_NET_PF_PROTO(PF_PPPOX, PX_PROTO_OL2TP);
1863 MODULE_ALIAS_L2TP_PWTYPE(7);
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