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Merge branch 'parisc-4.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller...
[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 *usockaddr_len, 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 *usockaddr_len = len;
973 error = 0;
974
975 sock_put(sk);
976 end:
977 return error;
978 }
979
980 /****************************************************************************
981 * ioctl() handlers.
982 *
983 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
984 * sockets. However, in order to control kernel tunnel features, we allow
985 * userspace to create a special "tunnel" PPPoX socket which is used for
986 * control only. Tunnel PPPoX sockets have session_id == 0 and simply allow
987 * the user application to issue L2TP setsockopt(), getsockopt() and ioctl()
988 * calls.
989 ****************************************************************************/
990
991 static void pppol2tp_copy_stats(struct pppol2tp_ioc_stats *dest,
992 struct l2tp_stats *stats)
993 {
994 dest->tx_packets = atomic_long_read(&stats->tx_packets);
995 dest->tx_bytes = atomic_long_read(&stats->tx_bytes);
996 dest->tx_errors = atomic_long_read(&stats->tx_errors);
997 dest->rx_packets = atomic_long_read(&stats->rx_packets);
998 dest->rx_bytes = atomic_long_read(&stats->rx_bytes);
999 dest->rx_seq_discards = atomic_long_read(&stats->rx_seq_discards);
1000 dest->rx_oos_packets = atomic_long_read(&stats->rx_oos_packets);
1001 dest->rx_errors = atomic_long_read(&stats->rx_errors);
1002 }
1003
1004 /* Session ioctl helper.
1005 */
1006 static int pppol2tp_session_ioctl(struct l2tp_session *session,
1007 unsigned int cmd, unsigned long arg)
1008 {
1009 struct ifreq ifr;
1010 int err = 0;
1011 struct sock *sk;
1012 int val = (int) arg;
1013 struct pppol2tp_session *ps = l2tp_session_priv(session);
1014 struct l2tp_tunnel *tunnel = session->tunnel;
1015 struct pppol2tp_ioc_stats stats;
1016
1017 l2tp_dbg(session, L2TP_MSG_CONTROL,
1018 "%s: pppol2tp_session_ioctl(cmd=%#x, arg=%#lx)\n",
1019 session->name, cmd, arg);
1020
1021 sk = pppol2tp_session_get_sock(session);
1022 if (!sk)
1023 return -EBADR;
1024
1025 switch (cmd) {
1026 case SIOCGIFMTU:
1027 err = -ENXIO;
1028 if (!(sk->sk_state & PPPOX_CONNECTED))
1029 break;
1030
1031 err = -EFAULT;
1032 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq)))
1033 break;
1034 ifr.ifr_mtu = session->mtu;
1035 if (copy_to_user((void __user *) arg, &ifr, sizeof(struct ifreq)))
1036 break;
1037
1038 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get mtu=%d\n",
1039 session->name, session->mtu);
1040 err = 0;
1041 break;
1042
1043 case SIOCSIFMTU:
1044 err = -ENXIO;
1045 if (!(sk->sk_state & PPPOX_CONNECTED))
1046 break;
1047
1048 err = -EFAULT;
1049 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq)))
1050 break;
1051
1052 session->mtu = ifr.ifr_mtu;
1053
1054 l2tp_info(session, L2TP_MSG_CONTROL, "%s: set mtu=%d\n",
1055 session->name, session->mtu);
1056 err = 0;
1057 break;
1058
1059 case PPPIOCGMRU:
1060 err = -ENXIO;
1061 if (!(sk->sk_state & PPPOX_CONNECTED))
1062 break;
1063
1064 err = -EFAULT;
1065 if (put_user(session->mru, (int __user *) arg))
1066 break;
1067
1068 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get mru=%d\n",
1069 session->name, session->mru);
1070 err = 0;
1071 break;
1072
1073 case PPPIOCSMRU:
1074 err = -ENXIO;
1075 if (!(sk->sk_state & PPPOX_CONNECTED))
1076 break;
1077
1078 err = -EFAULT;
1079 if (get_user(val, (int __user *) arg))
1080 break;
1081
1082 session->mru = val;
1083 l2tp_info(session, L2TP_MSG_CONTROL, "%s: set mru=%d\n",
1084 session->name, session->mru);
1085 err = 0;
1086 break;
1087
1088 case PPPIOCGFLAGS:
1089 err = -EFAULT;
1090 if (put_user(ps->flags, (int __user *) arg))
1091 break;
1092
1093 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get flags=%d\n",
1094 session->name, ps->flags);
1095 err = 0;
1096 break;
1097
1098 case PPPIOCSFLAGS:
1099 err = -EFAULT;
1100 if (get_user(val, (int __user *) arg))
1101 break;
1102 ps->flags = val;
1103 l2tp_info(session, L2TP_MSG_CONTROL, "%s: set flags=%d\n",
1104 session->name, ps->flags);
1105 err = 0;
1106 break;
1107
1108 case PPPIOCGL2TPSTATS:
1109 err = -ENXIO;
1110 if (!(sk->sk_state & PPPOX_CONNECTED))
1111 break;
1112
1113 memset(&stats, 0, sizeof(stats));
1114 stats.tunnel_id = tunnel->tunnel_id;
1115 stats.session_id = session->session_id;
1116 pppol2tp_copy_stats(&stats, &session->stats);
1117 if (copy_to_user((void __user *) arg, &stats,
1118 sizeof(stats)))
1119 break;
1120 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get L2TP stats\n",
1121 session->name);
1122 err = 0;
1123 break;
1124
1125 default:
1126 err = -ENOSYS;
1127 break;
1128 }
1129
1130 sock_put(sk);
1131
1132 return err;
1133 }
1134
1135 /* Tunnel ioctl helper.
1136 *
1137 * Note the special handling for PPPIOCGL2TPSTATS below. If the ioctl data
1138 * specifies a session_id, the session ioctl handler is called. This allows an
1139 * application to retrieve session stats via a tunnel socket.
1140 */
1141 static int pppol2tp_tunnel_ioctl(struct l2tp_tunnel *tunnel,
1142 unsigned int cmd, unsigned long arg)
1143 {
1144 int err = 0;
1145 struct sock *sk;
1146 struct pppol2tp_ioc_stats stats;
1147
1148 l2tp_dbg(tunnel, L2TP_MSG_CONTROL,
1149 "%s: pppol2tp_tunnel_ioctl(cmd=%#x, arg=%#lx)\n",
1150 tunnel->name, cmd, arg);
1151
1152 sk = tunnel->sock;
1153 sock_hold(sk);
1154
1155 switch (cmd) {
1156 case PPPIOCGL2TPSTATS:
1157 err = -ENXIO;
1158 if (!(sk->sk_state & PPPOX_CONNECTED))
1159 break;
1160
1161 if (copy_from_user(&stats, (void __user *) arg,
1162 sizeof(stats))) {
1163 err = -EFAULT;
1164 break;
1165 }
1166 if (stats.session_id != 0) {
1167 /* resend to session ioctl handler */
1168 struct l2tp_session *session =
1169 l2tp_session_get(sock_net(sk), tunnel,
1170 stats.session_id);
1171
1172 if (session) {
1173 err = pppol2tp_session_ioctl(session, cmd,
1174 arg);
1175 l2tp_session_dec_refcount(session);
1176 } else {
1177 err = -EBADR;
1178 }
1179 break;
1180 }
1181 #ifdef CONFIG_XFRM
1182 stats.using_ipsec = (sk->sk_policy[0] || sk->sk_policy[1]) ? 1 : 0;
1183 #endif
1184 pppol2tp_copy_stats(&stats, &tunnel->stats);
1185 if (copy_to_user((void __user *) arg, &stats, sizeof(stats))) {
1186 err = -EFAULT;
1187 break;
1188 }
1189 l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: get L2TP stats\n",
1190 tunnel->name);
1191 err = 0;
1192 break;
1193
1194 default:
1195 err = -ENOSYS;
1196 break;
1197 }
1198
1199 sock_put(sk);
1200
1201 return err;
1202 }
1203
1204 /* Main ioctl() handler.
1205 * Dispatch to tunnel or session helpers depending on the socket.
1206 */
1207 static int pppol2tp_ioctl(struct socket *sock, unsigned int cmd,
1208 unsigned long arg)
1209 {
1210 struct sock *sk = sock->sk;
1211 struct l2tp_session *session;
1212 struct l2tp_tunnel *tunnel;
1213 int err;
1214
1215 if (!sk)
1216 return 0;
1217
1218 err = -EBADF;
1219 if (sock_flag(sk, SOCK_DEAD) != 0)
1220 goto end;
1221
1222 err = -ENOTCONN;
1223 if ((sk->sk_user_data == NULL) ||
1224 (!(sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND))))
1225 goto end;
1226
1227 /* Get session context from the socket */
1228 err = -EBADF;
1229 session = pppol2tp_sock_to_session(sk);
1230 if (session == NULL)
1231 goto end;
1232
1233 /* Special case: if session's session_id is zero, treat ioctl as a
1234 * tunnel ioctl
1235 */
1236 if ((session->session_id == 0) &&
1237 (session->peer_session_id == 0)) {
1238 tunnel = session->tunnel;
1239 err = pppol2tp_tunnel_ioctl(tunnel, cmd, arg);
1240 goto end_put_sess;
1241 }
1242
1243 err = pppol2tp_session_ioctl(session, cmd, arg);
1244
1245 end_put_sess:
1246 sock_put(sk);
1247 end:
1248 return err;
1249 }
1250
1251 /*****************************************************************************
1252 * setsockopt() / getsockopt() support.
1253 *
1254 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
1255 * sockets. In order to control kernel tunnel features, we allow userspace to
1256 * create a special "tunnel" PPPoX socket which is used for control only.
1257 * Tunnel PPPoX sockets have session_id == 0 and simply allow the user
1258 * application to issue L2TP setsockopt(), getsockopt() and ioctl() calls.
1259 *****************************************************************************/
1260
1261 /* Tunnel setsockopt() helper.
1262 */
1263 static int pppol2tp_tunnel_setsockopt(struct sock *sk,
1264 struct l2tp_tunnel *tunnel,
1265 int optname, int val)
1266 {
1267 int err = 0;
1268
1269 switch (optname) {
1270 case PPPOL2TP_SO_DEBUG:
1271 tunnel->debug = val;
1272 l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: set debug=%x\n",
1273 tunnel->name, tunnel->debug);
1274 break;
1275
1276 default:
1277 err = -ENOPROTOOPT;
1278 break;
1279 }
1280
1281 return err;
1282 }
1283
1284 /* Session setsockopt helper.
1285 */
1286 static int pppol2tp_session_setsockopt(struct sock *sk,
1287 struct l2tp_session *session,
1288 int optname, int val)
1289 {
1290 int err = 0;
1291
1292 switch (optname) {
1293 case PPPOL2TP_SO_RECVSEQ:
1294 if ((val != 0) && (val != 1)) {
1295 err = -EINVAL;
1296 break;
1297 }
1298 session->recv_seq = !!val;
1299 l2tp_info(session, L2TP_MSG_CONTROL,
1300 "%s: set recv_seq=%d\n",
1301 session->name, session->recv_seq);
1302 break;
1303
1304 case PPPOL2TP_SO_SENDSEQ:
1305 if ((val != 0) && (val != 1)) {
1306 err = -EINVAL;
1307 break;
1308 }
1309 session->send_seq = !!val;
1310 {
1311 struct pppox_sock *po = pppox_sk(sk);
1312
1313 po->chan.hdrlen = val ? PPPOL2TP_L2TP_HDR_SIZE_SEQ :
1314 PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
1315 }
1316 l2tp_session_set_header_len(session, session->tunnel->version);
1317 l2tp_info(session, L2TP_MSG_CONTROL,
1318 "%s: set send_seq=%d\n",
1319 session->name, session->send_seq);
1320 break;
1321
1322 case PPPOL2TP_SO_LNSMODE:
1323 if ((val != 0) && (val != 1)) {
1324 err = -EINVAL;
1325 break;
1326 }
1327 session->lns_mode = !!val;
1328 l2tp_info(session, L2TP_MSG_CONTROL,
1329 "%s: set lns_mode=%d\n",
1330 session->name, session->lns_mode);
1331 break;
1332
1333 case PPPOL2TP_SO_DEBUG:
1334 session->debug = val;
1335 l2tp_info(session, L2TP_MSG_CONTROL, "%s: set debug=%x\n",
1336 session->name, session->debug);
1337 break;
1338
1339 case PPPOL2TP_SO_REORDERTO:
1340 session->reorder_timeout = msecs_to_jiffies(val);
1341 l2tp_info(session, L2TP_MSG_CONTROL,
1342 "%s: set reorder_timeout=%d\n",
1343 session->name, session->reorder_timeout);
1344 break;
1345
1346 default:
1347 err = -ENOPROTOOPT;
1348 break;
1349 }
1350
1351 return err;
1352 }
1353
1354 /* Main setsockopt() entry point.
1355 * Does API checks, then calls either the tunnel or session setsockopt
1356 * handler, according to whether the PPPoL2TP socket is a for a regular
1357 * session or the special tunnel type.
1358 */
1359 static int pppol2tp_setsockopt(struct socket *sock, int level, int optname,
1360 char __user *optval, unsigned int optlen)
1361 {
1362 struct sock *sk = sock->sk;
1363 struct l2tp_session *session;
1364 struct l2tp_tunnel *tunnel;
1365 int val;
1366 int err;
1367
1368 if (level != SOL_PPPOL2TP)
1369 return -EINVAL;
1370
1371 if (optlen < sizeof(int))
1372 return -EINVAL;
1373
1374 if (get_user(val, (int __user *)optval))
1375 return -EFAULT;
1376
1377 err = -ENOTCONN;
1378 if (sk->sk_user_data == NULL)
1379 goto end;
1380
1381 /* Get session context from the socket */
1382 err = -EBADF;
1383 session = pppol2tp_sock_to_session(sk);
1384 if (session == NULL)
1385 goto end;
1386
1387 /* Special case: if session_id == 0x0000, treat as operation on tunnel
1388 */
1389 if ((session->session_id == 0) &&
1390 (session->peer_session_id == 0)) {
1391 tunnel = session->tunnel;
1392 err = pppol2tp_tunnel_setsockopt(sk, tunnel, optname, val);
1393 } else {
1394 err = pppol2tp_session_setsockopt(sk, session, optname, val);
1395 }
1396
1397 sock_put(sk);
1398 end:
1399 return err;
1400 }
1401
1402 /* Tunnel getsockopt helper. Called with sock locked.
1403 */
1404 static int pppol2tp_tunnel_getsockopt(struct sock *sk,
1405 struct l2tp_tunnel *tunnel,
1406 int optname, int *val)
1407 {
1408 int err = 0;
1409
1410 switch (optname) {
1411 case PPPOL2TP_SO_DEBUG:
1412 *val = tunnel->debug;
1413 l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: get debug=%x\n",
1414 tunnel->name, tunnel->debug);
1415 break;
1416
1417 default:
1418 err = -ENOPROTOOPT;
1419 break;
1420 }
1421
1422 return err;
1423 }
1424
1425 /* Session getsockopt helper. Called with sock locked.
1426 */
1427 static int pppol2tp_session_getsockopt(struct sock *sk,
1428 struct l2tp_session *session,
1429 int optname, int *val)
1430 {
1431 int err = 0;
1432
1433 switch (optname) {
1434 case PPPOL2TP_SO_RECVSEQ:
1435 *val = session->recv_seq;
1436 l2tp_info(session, L2TP_MSG_CONTROL,
1437 "%s: get recv_seq=%d\n", session->name, *val);
1438 break;
1439
1440 case PPPOL2TP_SO_SENDSEQ:
1441 *val = session->send_seq;
1442 l2tp_info(session, L2TP_MSG_CONTROL,
1443 "%s: get send_seq=%d\n", session->name, *val);
1444 break;
1445
1446 case PPPOL2TP_SO_LNSMODE:
1447 *val = session->lns_mode;
1448 l2tp_info(session, L2TP_MSG_CONTROL,
1449 "%s: get lns_mode=%d\n", session->name, *val);
1450 break;
1451
1452 case PPPOL2TP_SO_DEBUG:
1453 *val = session->debug;
1454 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get debug=%d\n",
1455 session->name, *val);
1456 break;
1457
1458 case PPPOL2TP_SO_REORDERTO:
1459 *val = (int) jiffies_to_msecs(session->reorder_timeout);
1460 l2tp_info(session, L2TP_MSG_CONTROL,
1461 "%s: get reorder_timeout=%d\n", session->name, *val);
1462 break;
1463
1464 default:
1465 err = -ENOPROTOOPT;
1466 }
1467
1468 return err;
1469 }
1470
1471 /* Main getsockopt() entry point.
1472 * Does API checks, then calls either the tunnel or session getsockopt
1473 * handler, according to whether the PPPoX socket is a for a regular session
1474 * or the special tunnel type.
1475 */
1476 static int pppol2tp_getsockopt(struct socket *sock, int level, int optname,
1477 char __user *optval, int __user *optlen)
1478 {
1479 struct sock *sk = sock->sk;
1480 struct l2tp_session *session;
1481 struct l2tp_tunnel *tunnel;
1482 int val, len;
1483 int err;
1484
1485 if (level != SOL_PPPOL2TP)
1486 return -EINVAL;
1487
1488 if (get_user(len, optlen))
1489 return -EFAULT;
1490
1491 len = min_t(unsigned int, len, sizeof(int));
1492
1493 if (len < 0)
1494 return -EINVAL;
1495
1496 err = -ENOTCONN;
1497 if (sk->sk_user_data == NULL)
1498 goto end;
1499
1500 /* Get the session context */
1501 err = -EBADF;
1502 session = pppol2tp_sock_to_session(sk);
1503 if (session == NULL)
1504 goto end;
1505
1506 /* Special case: if session_id == 0x0000, treat as operation on tunnel */
1507 if ((session->session_id == 0) &&
1508 (session->peer_session_id == 0)) {
1509 tunnel = session->tunnel;
1510 err = pppol2tp_tunnel_getsockopt(sk, tunnel, optname, &val);
1511 if (err)
1512 goto end_put_sess;
1513 } else {
1514 err = pppol2tp_session_getsockopt(sk, session, optname, &val);
1515 if (err)
1516 goto end_put_sess;
1517 }
1518
1519 err = -EFAULT;
1520 if (put_user(len, optlen))
1521 goto end_put_sess;
1522
1523 if (copy_to_user((void __user *) optval, &val, len))
1524 goto end_put_sess;
1525
1526 err = 0;
1527
1528 end_put_sess:
1529 sock_put(sk);
1530 end:
1531 return err;
1532 }
1533
1534 /*****************************************************************************
1535 * /proc filesystem for debug
1536 * Since the original pppol2tp driver provided /proc/net/pppol2tp for
1537 * L2TPv2, we dump only L2TPv2 tunnels and sessions here.
1538 *****************************************************************************/
1539
1540 static unsigned int pppol2tp_net_id;
1541
1542 #ifdef CONFIG_PROC_FS
1543
1544 struct pppol2tp_seq_data {
1545 struct seq_net_private p;
1546 int tunnel_idx; /* current tunnel */
1547 int session_idx; /* index of session within current tunnel */
1548 struct l2tp_tunnel *tunnel;
1549 struct l2tp_session *session; /* NULL means get next tunnel */
1550 };
1551
1552 static void pppol2tp_next_tunnel(struct net *net, struct pppol2tp_seq_data *pd)
1553 {
1554 for (;;) {
1555 pd->tunnel = l2tp_tunnel_find_nth(net, pd->tunnel_idx);
1556 pd->tunnel_idx++;
1557
1558 if (pd->tunnel == NULL)
1559 break;
1560
1561 /* Ignore L2TPv3 tunnels */
1562 if (pd->tunnel->version < 3)
1563 break;
1564 }
1565 }
1566
1567 static void pppol2tp_next_session(struct net *net, struct pppol2tp_seq_data *pd)
1568 {
1569 pd->session = l2tp_session_get_nth(pd->tunnel, pd->session_idx);
1570 pd->session_idx++;
1571
1572 if (pd->session == NULL) {
1573 pd->session_idx = 0;
1574 pppol2tp_next_tunnel(net, pd);
1575 }
1576 }
1577
1578 static void *pppol2tp_seq_start(struct seq_file *m, loff_t *offs)
1579 {
1580 struct pppol2tp_seq_data *pd = SEQ_START_TOKEN;
1581 loff_t pos = *offs;
1582 struct net *net;
1583
1584 if (!pos)
1585 goto out;
1586
1587 BUG_ON(m->private == NULL);
1588 pd = m->private;
1589 net = seq_file_net(m);
1590
1591 if (pd->tunnel == NULL)
1592 pppol2tp_next_tunnel(net, pd);
1593 else
1594 pppol2tp_next_session(net, pd);
1595
1596 /* NULL tunnel and session indicates end of list */
1597 if ((pd->tunnel == NULL) && (pd->session == NULL))
1598 pd = NULL;
1599
1600 out:
1601 return pd;
1602 }
1603
1604 static void *pppol2tp_seq_next(struct seq_file *m, void *v, loff_t *pos)
1605 {
1606 (*pos)++;
1607 return NULL;
1608 }
1609
1610 static void pppol2tp_seq_stop(struct seq_file *p, void *v)
1611 {
1612 /* nothing to do */
1613 }
1614
1615 static void pppol2tp_seq_tunnel_show(struct seq_file *m, void *v)
1616 {
1617 struct l2tp_tunnel *tunnel = v;
1618
1619 seq_printf(m, "\nTUNNEL '%s', %c %d\n",
1620 tunnel->name,
1621 (tunnel == tunnel->sock->sk_user_data) ? 'Y' : 'N',
1622 refcount_read(&tunnel->ref_count) - 1);
1623 seq_printf(m, " %08x %ld/%ld/%ld %ld/%ld/%ld\n",
1624 tunnel->debug,
1625 atomic_long_read(&tunnel->stats.tx_packets),
1626 atomic_long_read(&tunnel->stats.tx_bytes),
1627 atomic_long_read(&tunnel->stats.tx_errors),
1628 atomic_long_read(&tunnel->stats.rx_packets),
1629 atomic_long_read(&tunnel->stats.rx_bytes),
1630 atomic_long_read(&tunnel->stats.rx_errors));
1631 }
1632
1633 static void pppol2tp_seq_session_show(struct seq_file *m, void *v)
1634 {
1635 struct l2tp_session *session = v;
1636 struct l2tp_tunnel *tunnel = session->tunnel;
1637 unsigned char state;
1638 char user_data_ok;
1639 struct sock *sk;
1640 u32 ip = 0;
1641 u16 port = 0;
1642
1643 if (tunnel->sock) {
1644 struct inet_sock *inet = inet_sk(tunnel->sock);
1645 ip = ntohl(inet->inet_saddr);
1646 port = ntohs(inet->inet_sport);
1647 }
1648
1649 sk = pppol2tp_session_get_sock(session);
1650 if (sk) {
1651 state = sk->sk_state;
1652 user_data_ok = (session == sk->sk_user_data) ? 'Y' : 'N';
1653 } else {
1654 state = 0;
1655 user_data_ok = 'N';
1656 }
1657
1658 seq_printf(m, " SESSION '%s' %08X/%d %04X/%04X -> "
1659 "%04X/%04X %d %c\n",
1660 session->name, ip, port,
1661 tunnel->tunnel_id,
1662 session->session_id,
1663 tunnel->peer_tunnel_id,
1664 session->peer_session_id,
1665 state, user_data_ok);
1666 seq_printf(m, " %d/%d/%c/%c/%s %08x %u\n",
1667 session->mtu, session->mru,
1668 session->recv_seq ? 'R' : '-',
1669 session->send_seq ? 'S' : '-',
1670 session->lns_mode ? "LNS" : "LAC",
1671 session->debug,
1672 jiffies_to_msecs(session->reorder_timeout));
1673 seq_printf(m, " %hu/%hu %ld/%ld/%ld %ld/%ld/%ld\n",
1674 session->nr, session->ns,
1675 atomic_long_read(&session->stats.tx_packets),
1676 atomic_long_read(&session->stats.tx_bytes),
1677 atomic_long_read(&session->stats.tx_errors),
1678 atomic_long_read(&session->stats.rx_packets),
1679 atomic_long_read(&session->stats.rx_bytes),
1680 atomic_long_read(&session->stats.rx_errors));
1681
1682 if (sk) {
1683 struct pppox_sock *po = pppox_sk(sk);
1684
1685 seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan));
1686 sock_put(sk);
1687 }
1688 }
1689
1690 static int pppol2tp_seq_show(struct seq_file *m, void *v)
1691 {
1692 struct pppol2tp_seq_data *pd = v;
1693
1694 /* display header on line 1 */
1695 if (v == SEQ_START_TOKEN) {
1696 seq_puts(m, "PPPoL2TP driver info, " PPPOL2TP_DRV_VERSION "\n");
1697 seq_puts(m, "TUNNEL name, user-data-ok session-count\n");
1698 seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
1699 seq_puts(m, " SESSION name, addr/port src-tid/sid "
1700 "dest-tid/sid state user-data-ok\n");
1701 seq_puts(m, " mtu/mru/rcvseq/sendseq/lns debug reorderto\n");
1702 seq_puts(m, " nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
1703 goto out;
1704 }
1705
1706 /* Show the tunnel or session context.
1707 */
1708 if (!pd->session) {
1709 pppol2tp_seq_tunnel_show(m, pd->tunnel);
1710 } else {
1711 pppol2tp_seq_session_show(m, pd->session);
1712 l2tp_session_dec_refcount(pd->session);
1713 }
1714
1715 out:
1716 return 0;
1717 }
1718
1719 static const struct seq_operations pppol2tp_seq_ops = {
1720 .start = pppol2tp_seq_start,
1721 .next = pppol2tp_seq_next,
1722 .stop = pppol2tp_seq_stop,
1723 .show = pppol2tp_seq_show,
1724 };
1725
1726 /* Called when our /proc file is opened. We allocate data for use when
1727 * iterating our tunnel / session contexts and store it in the private
1728 * data of the seq_file.
1729 */
1730 static int pppol2tp_proc_open(struct inode *inode, struct file *file)
1731 {
1732 return seq_open_net(inode, file, &pppol2tp_seq_ops,
1733 sizeof(struct pppol2tp_seq_data));
1734 }
1735
1736 static const struct file_operations pppol2tp_proc_fops = {
1737 .open = pppol2tp_proc_open,
1738 .read = seq_read,
1739 .llseek = seq_lseek,
1740 .release = seq_release_net,
1741 };
1742
1743 #endif /* CONFIG_PROC_FS */
1744
1745 /*****************************************************************************
1746 * Network namespace
1747 *****************************************************************************/
1748
1749 static __net_init int pppol2tp_init_net(struct net *net)
1750 {
1751 struct proc_dir_entry *pde;
1752 int err = 0;
1753
1754 pde = proc_create("pppol2tp", S_IRUGO, net->proc_net,
1755 &pppol2tp_proc_fops);
1756 if (!pde) {
1757 err = -ENOMEM;
1758 goto out;
1759 }
1760
1761 out:
1762 return err;
1763 }
1764
1765 static __net_exit void pppol2tp_exit_net(struct net *net)
1766 {
1767 remove_proc_entry("pppol2tp", net->proc_net);
1768 }
1769
1770 static struct pernet_operations pppol2tp_net_ops = {
1771 .init = pppol2tp_init_net,
1772 .exit = pppol2tp_exit_net,
1773 .id = &pppol2tp_net_id,
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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