?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
bpf: Prevent memory disambiguation attack
[linux/fpc-iii.git] / net / l2tp / l2tp_ppp.c
blob0c4530ad74be66e2bd6b026d8b4a47a8dd138967
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
623 if (sockaddr_len != sizeof(struct sockaddr_pppol2tp) &&
624 sockaddr_len != sizeof(struct sockaddr_pppol2tpv3) &&
625 sockaddr_len != sizeof(struct sockaddr_pppol2tpin6) &&
626 sockaddr_len != sizeof(struct sockaddr_pppol2tpv3in6))
627 goto end;
628
629 if (sp->sa_protocol != PX_PROTO_OL2TP)
630 goto end;
631
632 /* Check for already bound sockets */
633 error = -EBUSY;
634 if (sk->sk_state & PPPOX_CONNECTED)
635 goto end;
636
637 /* We don't supporting rebinding anyway */
638 error = -EALREADY;
639 if (sk->sk_user_data)
640 goto end; /* socket is already attached */
641
642 /* Get params from socket address. Handle L2TPv2 and L2TPv3.
643 * This is nasty because there are different sockaddr_pppol2tp
644 * structs for L2TPv2, L2TPv3, over IPv4 and IPv6. We use
645 * the sockaddr size to determine which structure the caller
646 * is using.
647 */
648 peer_tunnel_id = 0;
649 if (sockaddr_len == sizeof(struct sockaddr_pppol2tp)) {
650 fd = sp->pppol2tp.fd;
651 tunnel_id = sp->pppol2tp.s_tunnel;
652 peer_tunnel_id = sp->pppol2tp.d_tunnel;
653 session_id = sp->pppol2tp.s_session;
654 peer_session_id = sp->pppol2tp.d_session;
655 } else if (sockaddr_len == sizeof(struct sockaddr_pppol2tpv3)) {
656 struct sockaddr_pppol2tpv3 *sp3 =
657 (struct sockaddr_pppol2tpv3 *) sp;
658 ver = 3;
659 fd = sp3->pppol2tp.fd;
660 tunnel_id = sp3->pppol2tp.s_tunnel;
661 peer_tunnel_id = sp3->pppol2tp.d_tunnel;
662 session_id = sp3->pppol2tp.s_session;
663 peer_session_id = sp3->pppol2tp.d_session;
664 } else if (sockaddr_len == sizeof(struct sockaddr_pppol2tpin6)) {
665 struct sockaddr_pppol2tpin6 *sp6 =
666 (struct sockaddr_pppol2tpin6 *) sp;
667 fd = sp6->pppol2tp.fd;
668 tunnel_id = sp6->pppol2tp.s_tunnel;
669 peer_tunnel_id = sp6->pppol2tp.d_tunnel;
670 session_id = sp6->pppol2tp.s_session;
671 peer_session_id = sp6->pppol2tp.d_session;
672 } else if (sockaddr_len == sizeof(struct sockaddr_pppol2tpv3in6)) {
673 struct sockaddr_pppol2tpv3in6 *sp6 =
674 (struct sockaddr_pppol2tpv3in6 *) sp;
675 ver = 3;
676 fd = sp6->pppol2tp.fd;
677 tunnel_id = sp6->pppol2tp.s_tunnel;
678 peer_tunnel_id = sp6->pppol2tp.d_tunnel;
679 session_id = sp6->pppol2tp.s_session;
680 peer_session_id = sp6->pppol2tp.d_session;
681 } else {
682 error = -EINVAL;
683 goto end; /* bad socket address */
684 }
685
686 /* Don't bind if tunnel_id is 0 */
687 error = -EINVAL;
688 if (tunnel_id == 0)
689 goto end;
690
691 tunnel = l2tp_tunnel_get(sock_net(sk), tunnel_id);
692 if (tunnel)
693 drop_tunnel = true;
694
695 /* Special case: create tunnel context if session_id and
696 * peer_session_id is 0. Otherwise look up tunnel using supplied
697 * tunnel id.
698 */
699 if ((session_id == 0) && (peer_session_id == 0)) {
700 if (tunnel == NULL) {
701 struct l2tp_tunnel_cfg tcfg = {
702 .encap = L2TP_ENCAPTYPE_UDP,
703 .debug = 0,
704 };
705 error = l2tp_tunnel_create(sock_net(sk), fd, ver, tunnel_id, peer_tunnel_id, &tcfg, &tunnel);
706 if (error < 0)
707 goto end;
708
709 l2tp_tunnel_inc_refcount(tunnel);
710 error = l2tp_tunnel_register(tunnel, sock_net(sk),
711 &tcfg);
712 if (error < 0) {
713 kfree(tunnel);
714 goto end;
715 }
716 drop_tunnel = true;
717 }
718 } else {
719 /* Error if we can't find the tunnel */
720 error = -ENOENT;
721 if (tunnel == NULL)
722 goto end;
723
724 /* Error if socket is not prepped */
725 if (tunnel->sock == NULL)
726 goto end;
727 }
728
729 if (tunnel->recv_payload_hook == NULL)
730 tunnel->recv_payload_hook = pppol2tp_recv_payload_hook;
731
732 if (tunnel->peer_tunnel_id == 0)
733 tunnel->peer_tunnel_id = peer_tunnel_id;
734
735 session = l2tp_session_get(sock_net(sk), tunnel, session_id);
736 if (session) {
737 drop_refcnt = true;
738 ps = l2tp_session_priv(session);
739
740 /* Using a pre-existing session is fine as long as it hasn't
741 * been connected yet.
742 */
743 mutex_lock(&ps->sk_lock);
744 if (rcu_dereference_protected(ps->sk,
745 lockdep_is_held(&ps->sk_lock))) {
746 mutex_unlock(&ps->sk_lock);
747 error = -EEXIST;
748 goto end;
749 }
750 } else {
751 /* Default MTU must allow space for UDP/L2TP/PPP headers */
752 cfg.mtu = 1500 - PPPOL2TP_HEADER_OVERHEAD;
753 cfg.mru = cfg.mtu;
754
755 session = l2tp_session_create(sizeof(struct pppol2tp_session),
756 tunnel, session_id,
757 peer_session_id, &cfg);
758 if (IS_ERR(session)) {
759 error = PTR_ERR(session);
760 goto end;
761 }
762
763 pppol2tp_session_init(session);
764 ps = l2tp_session_priv(session);
765 l2tp_session_inc_refcount(session);
766
767 mutex_lock(&ps->sk_lock);
768 error = l2tp_session_register(session, tunnel);
769 if (error < 0) {
770 mutex_unlock(&ps->sk_lock);
771 kfree(session);
772 goto end;
773 }
774 drop_refcnt = true;
775 }
776
777 /* Special case: if source & dest session_id == 0x0000, this
778 * socket is being created to manage the tunnel. Just set up
779 * the internal context for use by ioctl() and sockopt()
780 * handlers.
781 */
782 if ((session->session_id == 0) &&
783 (session->peer_session_id == 0)) {
784 error = 0;
785 goto out_no_ppp;
786 }
787
788 /* The only header we need to worry about is the L2TP
789 * header. This size is different depending on whether
790 * sequence numbers are enabled for the data channel.
791 */
792 po->chan.hdrlen = PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
793
794 po->chan.private = sk;
795 po->chan.ops = &pppol2tp_chan_ops;
796 po->chan.mtu = session->mtu;
797
798 error = ppp_register_net_channel(sock_net(sk), &po->chan);
799 if (error) {
800 mutex_unlock(&ps->sk_lock);
801 goto end;
802 }
803
804 out_no_ppp:
805 /* This is how we get the session context from the socket. */
806 sock_hold(sk);
807 sk->sk_user_data = session;
808 rcu_assign_pointer(ps->sk, sk);
809 mutex_unlock(&ps->sk_lock);
810
811 /* Keep the reference we've grabbed on the session: sk doesn't expect
812 * the session to disappear. pppol2tp_session_destruct() is responsible
813 * for dropping it.
814 */
815 drop_refcnt = false;
816
817 sk->sk_state = PPPOX_CONNECTED;
818 l2tp_info(session, L2TP_MSG_CONTROL, "%s: created\n",
819 session->name);
820
821 end:
822 if (drop_refcnt)
823 l2tp_session_dec_refcount(session);
824 if (drop_tunnel)
825 l2tp_tunnel_dec_refcount(tunnel);
826 release_sock(sk);
827
828 return error;
829 }
830
831 #ifdef CONFIG_L2TP_V3
832
833 /* Called when creating sessions via the netlink interface. */
834 static int pppol2tp_session_create(struct net *net, struct l2tp_tunnel *tunnel,
835 u32 session_id, u32 peer_session_id,
836 struct l2tp_session_cfg *cfg)
837 {
838 int error;
839 struct l2tp_session *session;
840
841 /* Error if tunnel socket is not prepped */
842 if (!tunnel->sock) {
843 error = -ENOENT;
844 goto err;
845 }
846
847 /* Default MTU values. */
848 if (cfg->mtu == 0)
849 cfg->mtu = 1500 - PPPOL2TP_HEADER_OVERHEAD;
850 if (cfg->mru == 0)
851 cfg->mru = cfg->mtu;
852
853 /* Allocate and initialize a new session context. */
854 session = l2tp_session_create(sizeof(struct pppol2tp_session),
855 tunnel, session_id,
856 peer_session_id, cfg);
857 if (IS_ERR(session)) {
858 error = PTR_ERR(session);
859 goto err;
860 }
861
862 pppol2tp_session_init(session);
863
864 error = l2tp_session_register(session, tunnel);
865 if (error < 0)
866 goto err_sess;
867
868 return 0;
869
870 err_sess:
871 kfree(session);
872 err:
873 return error;
874 }
875
876 #endif /* CONFIG_L2TP_V3 */
877
878 /* getname() support.
879 */
880 static int pppol2tp_getname(struct socket *sock, struct sockaddr *uaddr,
881 int *usockaddr_len, int peer)
882 {
883 int len = 0;
884 int error = 0;
885 struct l2tp_session *session;
886 struct l2tp_tunnel *tunnel;
887 struct sock *sk = sock->sk;
888 struct inet_sock *inet;
889 struct pppol2tp_session *pls;
890
891 error = -ENOTCONN;
892 if (sk == NULL)
893 goto end;
894 if (!(sk->sk_state & PPPOX_CONNECTED))
895 goto end;
896
897 error = -EBADF;
898 session = pppol2tp_sock_to_session(sk);
899 if (session == NULL)
900 goto end;
901
902 pls = l2tp_session_priv(session);
903 tunnel = session->tunnel;
904
905 inet = inet_sk(tunnel->sock);
906 if ((tunnel->version == 2) && (tunnel->sock->sk_family == AF_INET)) {
907 struct sockaddr_pppol2tp sp;
908 len = sizeof(sp);
909 memset(&sp, 0, len);
910 sp.sa_family = AF_PPPOX;
911 sp.sa_protocol = PX_PROTO_OL2TP;
912 sp.pppol2tp.fd = tunnel->fd;
913 sp.pppol2tp.pid = pls->owner;
914 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
915 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
916 sp.pppol2tp.s_session = session->session_id;
917 sp.pppol2tp.d_session = session->peer_session_id;
918 sp.pppol2tp.addr.sin_family = AF_INET;
919 sp.pppol2tp.addr.sin_port = inet->inet_dport;
920 sp.pppol2tp.addr.sin_addr.s_addr = inet->inet_daddr;
921 memcpy(uaddr, &sp, len);
922 #if IS_ENABLED(CONFIG_IPV6)
923 } else if ((tunnel->version == 2) &&
924 (tunnel->sock->sk_family == AF_INET6)) {
925 struct sockaddr_pppol2tpin6 sp;
926
927 len = sizeof(sp);
928 memset(&sp, 0, len);
929 sp.sa_family = AF_PPPOX;
930 sp.sa_protocol = PX_PROTO_OL2TP;
931 sp.pppol2tp.fd = tunnel->fd;
932 sp.pppol2tp.pid = pls->owner;
933 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
934 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
935 sp.pppol2tp.s_session = session->session_id;
936 sp.pppol2tp.d_session = session->peer_session_id;
937 sp.pppol2tp.addr.sin6_family = AF_INET6;
938 sp.pppol2tp.addr.sin6_port = inet->inet_dport;
939 memcpy(&sp.pppol2tp.addr.sin6_addr, &tunnel->sock->sk_v6_daddr,
940 sizeof(tunnel->sock->sk_v6_daddr));
941 memcpy(uaddr, &sp, len);
942 } else if ((tunnel->version == 3) &&
943 (tunnel->sock->sk_family == AF_INET6)) {
944 struct sockaddr_pppol2tpv3in6 sp;
945
946 len = sizeof(sp);
947 memset(&sp, 0, len);
948 sp.sa_family = AF_PPPOX;
949 sp.sa_protocol = PX_PROTO_OL2TP;
950 sp.pppol2tp.fd = tunnel->fd;
951 sp.pppol2tp.pid = pls->owner;
952 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
953 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
954 sp.pppol2tp.s_session = session->session_id;
955 sp.pppol2tp.d_session = session->peer_session_id;
956 sp.pppol2tp.addr.sin6_family = AF_INET6;
957 sp.pppol2tp.addr.sin6_port = inet->inet_dport;
958 memcpy(&sp.pppol2tp.addr.sin6_addr, &tunnel->sock->sk_v6_daddr,
959 sizeof(tunnel->sock->sk_v6_daddr));
960 memcpy(uaddr, &sp, len);
961 #endif
962 } else if (tunnel->version == 3) {
963 struct sockaddr_pppol2tpv3 sp;
964 len = sizeof(sp);
965 memset(&sp, 0, len);
966 sp.sa_family = AF_PPPOX;
967 sp.sa_protocol = PX_PROTO_OL2TP;
968 sp.pppol2tp.fd = tunnel->fd;
969 sp.pppol2tp.pid = pls->owner;
970 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
971 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
972 sp.pppol2tp.s_session = session->session_id;
973 sp.pppol2tp.d_session = session->peer_session_id;
974 sp.pppol2tp.addr.sin_family = AF_INET;
975 sp.pppol2tp.addr.sin_port = inet->inet_dport;
976 sp.pppol2tp.addr.sin_addr.s_addr = inet->inet_daddr;
977 memcpy(uaddr, &sp, len);
978 }
979
980 *usockaddr_len = len;
981 error = 0;
982
983 sock_put(sk);
984 end:
985 return error;
986 }
987
988 /****************************************************************************
989 * ioctl() handlers.
990 *
991 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
992 * sockets. However, in order to control kernel tunnel features, we allow
993 * userspace to create a special "tunnel" PPPoX socket which is used for
994 * control only. Tunnel PPPoX sockets have session_id == 0 and simply allow
995 * the user application to issue L2TP setsockopt(), getsockopt() and ioctl()
996 * calls.
997 ****************************************************************************/
998
999 static void pppol2tp_copy_stats(struct pppol2tp_ioc_stats *dest,
1000 struct l2tp_stats *stats)
1001 {
1002 dest->tx_packets = atomic_long_read(&stats->tx_packets);
1003 dest->tx_bytes = atomic_long_read(&stats->tx_bytes);
1004 dest->tx_errors = atomic_long_read(&stats->tx_errors);
1005 dest->rx_packets = atomic_long_read(&stats->rx_packets);
1006 dest->rx_bytes = atomic_long_read(&stats->rx_bytes);
1007 dest->rx_seq_discards = atomic_long_read(&stats->rx_seq_discards);
1008 dest->rx_oos_packets = atomic_long_read(&stats->rx_oos_packets);
1009 dest->rx_errors = atomic_long_read(&stats->rx_errors);
1010 }
1011
1012 /* Session ioctl helper.
1013 */
1014 static int pppol2tp_session_ioctl(struct l2tp_session *session,
1015 unsigned int cmd, unsigned long arg)
1016 {
1017 struct ifreq ifr;
1018 int err = 0;
1019 struct sock *sk;
1020 int val = (int) arg;
1021 struct pppol2tp_session *ps = l2tp_session_priv(session);
1022 struct l2tp_tunnel *tunnel = session->tunnel;
1023 struct pppol2tp_ioc_stats stats;
1024
1025 l2tp_dbg(session, L2TP_MSG_CONTROL,
1026 "%s: pppol2tp_session_ioctl(cmd=%#x, arg=%#lx)\n",
1027 session->name, cmd, arg);
1028
1029 sk = pppol2tp_session_get_sock(session);
1030 if (!sk)
1031 return -EBADR;
1032
1033 switch (cmd) {
1034 case SIOCGIFMTU:
1035 err = -ENXIO;
1036 if (!(sk->sk_state & PPPOX_CONNECTED))
1037 break;
1038
1039 err = -EFAULT;
1040 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq)))
1041 break;
1042 ifr.ifr_mtu = session->mtu;
1043 if (copy_to_user((void __user *) arg, &ifr, sizeof(struct ifreq)))
1044 break;
1045
1046 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get mtu=%d\n",
1047 session->name, session->mtu);
1048 err = 0;
1049 break;
1050
1051 case SIOCSIFMTU:
1052 err = -ENXIO;
1053 if (!(sk->sk_state & PPPOX_CONNECTED))
1054 break;
1055
1056 err = -EFAULT;
1057 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq)))
1058 break;
1059
1060 session->mtu = ifr.ifr_mtu;
1061
1062 l2tp_info(session, L2TP_MSG_CONTROL, "%s: set mtu=%d\n",
1063 session->name, session->mtu);
1064 err = 0;
1065 break;
1066
1067 case PPPIOCGMRU:
1068 err = -ENXIO;
1069 if (!(sk->sk_state & PPPOX_CONNECTED))
1070 break;
1071
1072 err = -EFAULT;
1073 if (put_user(session->mru, (int __user *) arg))
1074 break;
1075
1076 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get mru=%d\n",
1077 session->name, session->mru);
1078 err = 0;
1079 break;
1080
1081 case PPPIOCSMRU:
1082 err = -ENXIO;
1083 if (!(sk->sk_state & PPPOX_CONNECTED))
1084 break;
1085
1086 err = -EFAULT;
1087 if (get_user(val, (int __user *) arg))
1088 break;
1089
1090 session->mru = val;
1091 l2tp_info(session, L2TP_MSG_CONTROL, "%s: set mru=%d\n",
1092 session->name, session->mru);
1093 err = 0;
1094 break;
1095
1096 case PPPIOCGFLAGS:
1097 err = -EFAULT;
1098 if (put_user(ps->flags, (int __user *) arg))
1099 break;
1100
1101 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get flags=%d\n",
1102 session->name, ps->flags);
1103 err = 0;
1104 break;
1105
1106 case PPPIOCSFLAGS:
1107 err = -EFAULT;
1108 if (get_user(val, (int __user *) arg))
1109 break;
1110 ps->flags = val;
1111 l2tp_info(session, L2TP_MSG_CONTROL, "%s: set flags=%d\n",
1112 session->name, ps->flags);
1113 err = 0;
1114 break;
1115
1116 case PPPIOCGL2TPSTATS:
1117 err = -ENXIO;
1118 if (!(sk->sk_state & PPPOX_CONNECTED))
1119 break;
1120
1121 memset(&stats, 0, sizeof(stats));
1122 stats.tunnel_id = tunnel->tunnel_id;
1123 stats.session_id = session->session_id;
1124 pppol2tp_copy_stats(&stats, &session->stats);
1125 if (copy_to_user((void __user *) arg, &stats,
1126 sizeof(stats)))
1127 break;
1128 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get L2TP stats\n",
1129 session->name);
1130 err = 0;
1131 break;
1132
1133 default:
1134 err = -ENOSYS;
1135 break;
1136 }
1137
1138 sock_put(sk);
1139
1140 return err;
1141 }
1142
1143 /* Tunnel ioctl helper.
1144 *
1145 * Note the special handling for PPPIOCGL2TPSTATS below. If the ioctl data
1146 * specifies a session_id, the session ioctl handler is called. This allows an
1147 * application to retrieve session stats via a tunnel socket.
1148 */
1149 static int pppol2tp_tunnel_ioctl(struct l2tp_tunnel *tunnel,
1150 unsigned int cmd, unsigned long arg)
1151 {
1152 int err = 0;
1153 struct sock *sk;
1154 struct pppol2tp_ioc_stats stats;
1155
1156 l2tp_dbg(tunnel, L2TP_MSG_CONTROL,
1157 "%s: pppol2tp_tunnel_ioctl(cmd=%#x, arg=%#lx)\n",
1158 tunnel->name, cmd, arg);
1159
1160 sk = tunnel->sock;
1161 sock_hold(sk);
1162
1163 switch (cmd) {
1164 case PPPIOCGL2TPSTATS:
1165 err = -ENXIO;
1166 if (!(sk->sk_state & PPPOX_CONNECTED))
1167 break;
1168
1169 if (copy_from_user(&stats, (void __user *) arg,
1170 sizeof(stats))) {
1171 err = -EFAULT;
1172 break;
1173 }
1174 if (stats.session_id != 0) {
1175 /* resend to session ioctl handler */
1176 struct l2tp_session *session =
1177 l2tp_session_get(sock_net(sk), tunnel,
1178 stats.session_id);
1179
1180 if (session) {
1181 err = pppol2tp_session_ioctl(session, cmd,
1182 arg);
1183 l2tp_session_dec_refcount(session);
1184 } else {
1185 err = -EBADR;
1186 }
1187 break;
1188 }
1189 #ifdef CONFIG_XFRM
1190 stats.using_ipsec = (sk->sk_policy[0] || sk->sk_policy[1]) ? 1 : 0;
1191 #endif
1192 pppol2tp_copy_stats(&stats, &tunnel->stats);
1193 if (copy_to_user((void __user *) arg, &stats, sizeof(stats))) {
1194 err = -EFAULT;
1195 break;
1196 }
1197 l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: get L2TP stats\n",
1198 tunnel->name);
1199 err = 0;
1200 break;
1201
1202 default:
1203 err = -ENOSYS;
1204 break;
1205 }
1206
1207 sock_put(sk);
1208
1209 return err;
1210 }
1211
1212 /* Main ioctl() handler.
1213 * Dispatch to tunnel or session helpers depending on the socket.
1214 */
1215 static int pppol2tp_ioctl(struct socket *sock, unsigned int cmd,
1216 unsigned long arg)
1217 {
1218 struct sock *sk = sock->sk;
1219 struct l2tp_session *session;
1220 struct l2tp_tunnel *tunnel;
1221 int err;
1222
1223 if (!sk)
1224 return 0;
1225
1226 err = -EBADF;
1227 if (sock_flag(sk, SOCK_DEAD) != 0)
1228 goto end;
1229
1230 err = -ENOTCONN;
1231 if ((sk->sk_user_data == NULL) ||
1232 (!(sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND))))
1233 goto end;
1234
1235 /* Get session context from the socket */
1236 err = -EBADF;
1237 session = pppol2tp_sock_to_session(sk);
1238 if (session == NULL)
1239 goto end;
1240
1241 /* Special case: if session's session_id is zero, treat ioctl as a
1242 * tunnel ioctl
1243 */
1244 if ((session->session_id == 0) &&
1245 (session->peer_session_id == 0)) {
1246 tunnel = session->tunnel;
1247 err = pppol2tp_tunnel_ioctl(tunnel, cmd, arg);
1248 goto end_put_sess;
1249 }
1250
1251 err = pppol2tp_session_ioctl(session, cmd, arg);
1252
1253 end_put_sess:
1254 sock_put(sk);
1255 end:
1256 return err;
1257 }
1258
1259 /*****************************************************************************
1260 * setsockopt() / getsockopt() support.
1261 *
1262 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
1263 * sockets. In order to control kernel tunnel features, we allow userspace to
1264 * create a special "tunnel" PPPoX socket which is used for control only.
1265 * Tunnel PPPoX sockets have session_id == 0 and simply allow the user
1266 * application to issue L2TP setsockopt(), getsockopt() and ioctl() calls.
1267 *****************************************************************************/
1268
1269 /* Tunnel setsockopt() helper.
1270 */
1271 static int pppol2tp_tunnel_setsockopt(struct sock *sk,
1272 struct l2tp_tunnel *tunnel,
1273 int optname, int val)
1274 {
1275 int err = 0;
1276
1277 switch (optname) {
1278 case PPPOL2TP_SO_DEBUG:
1279 tunnel->debug = val;
1280 l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: set debug=%x\n",
1281 tunnel->name, tunnel->debug);
1282 break;
1283
1284 default:
1285 err = -ENOPROTOOPT;
1286 break;
1287 }
1288
1289 return err;
1290 }
1291
1292 /* Session setsockopt helper.
1293 */
1294 static int pppol2tp_session_setsockopt(struct sock *sk,
1295 struct l2tp_session *session,
1296 int optname, int val)
1297 {
1298 int err = 0;
1299
1300 switch (optname) {
1301 case PPPOL2TP_SO_RECVSEQ:
1302 if ((val != 0) && (val != 1)) {
1303 err = -EINVAL;
1304 break;
1305 }
1306 session->recv_seq = !!val;
1307 l2tp_info(session, L2TP_MSG_CONTROL,
1308 "%s: set recv_seq=%d\n",
1309 session->name, session->recv_seq);
1310 break;
1311
1312 case PPPOL2TP_SO_SENDSEQ:
1313 if ((val != 0) && (val != 1)) {
1314 err = -EINVAL;
1315 break;
1316 }
1317 session->send_seq = !!val;
1318 {
1319 struct pppox_sock *po = pppox_sk(sk);
1320
1321 po->chan.hdrlen = val ? PPPOL2TP_L2TP_HDR_SIZE_SEQ :
1322 PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
1323 }
1324 l2tp_session_set_header_len(session, session->tunnel->version);
1325 l2tp_info(session, L2TP_MSG_CONTROL,
1326 "%s: set send_seq=%d\n",
1327 session->name, session->send_seq);
1328 break;
1329
1330 case PPPOL2TP_SO_LNSMODE:
1331 if ((val != 0) && (val != 1)) {
1332 err = -EINVAL;
1333 break;
1334 }
1335 session->lns_mode = !!val;
1336 l2tp_info(session, L2TP_MSG_CONTROL,
1337 "%s: set lns_mode=%d\n",
1338 session->name, session->lns_mode);
1339 break;
1340
1341 case PPPOL2TP_SO_DEBUG:
1342 session->debug = val;
1343 l2tp_info(session, L2TP_MSG_CONTROL, "%s: set debug=%x\n",
1344 session->name, session->debug);
1345 break;
1346
1347 case PPPOL2TP_SO_REORDERTO:
1348 session->reorder_timeout = msecs_to_jiffies(val);
1349 l2tp_info(session, L2TP_MSG_CONTROL,
1350 "%s: set reorder_timeout=%d\n",
1351 session->name, session->reorder_timeout);
1352 break;
1353
1354 default:
1355 err = -ENOPROTOOPT;
1356 break;
1357 }
1358
1359 return err;
1360 }
1361
1362 /* Main setsockopt() entry point.
1363 * Does API checks, then calls either the tunnel or session setsockopt
1364 * handler, according to whether the PPPoL2TP socket is a for a regular
1365 * session or the special tunnel type.
1366 */
1367 static int pppol2tp_setsockopt(struct socket *sock, int level, int optname,
1368 char __user *optval, unsigned int optlen)
1369 {
1370 struct sock *sk = sock->sk;
1371 struct l2tp_session *session;
1372 struct l2tp_tunnel *tunnel;
1373 int val;
1374 int err;
1375
1376 if (level != SOL_PPPOL2TP)
1377 return -EINVAL;
1378
1379 if (optlen < sizeof(int))
1380 return -EINVAL;
1381
1382 if (get_user(val, (int __user *)optval))
1383 return -EFAULT;
1384
1385 err = -ENOTCONN;
1386 if (sk->sk_user_data == NULL)
1387 goto end;
1388
1389 /* Get session context from the socket */
1390 err = -EBADF;
1391 session = pppol2tp_sock_to_session(sk);
1392 if (session == NULL)
1393 goto end;
1394
1395 /* Special case: if session_id == 0x0000, treat as operation on tunnel
1396 */
1397 if ((session->session_id == 0) &&
1398 (session->peer_session_id == 0)) {
1399 tunnel = session->tunnel;
1400 err = pppol2tp_tunnel_setsockopt(sk, tunnel, optname, val);
1401 } else {
1402 err = pppol2tp_session_setsockopt(sk, session, optname, val);
1403 }
1404
1405 sock_put(sk);
1406 end:
1407 return err;
1408 }
1409
1410 /* Tunnel getsockopt helper. Called with sock locked.
1411 */
1412 static int pppol2tp_tunnel_getsockopt(struct sock *sk,
1413 struct l2tp_tunnel *tunnel,
1414 int optname, int *val)
1415 {
1416 int err = 0;
1417
1418 switch (optname) {
1419 case PPPOL2TP_SO_DEBUG:
1420 *val = tunnel->debug;
1421 l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: get debug=%x\n",
1422 tunnel->name, tunnel->debug);
1423 break;
1424
1425 default:
1426 err = -ENOPROTOOPT;
1427 break;
1428 }
1429
1430 return err;
1431 }
1432
1433 /* Session getsockopt helper. Called with sock locked.
1434 */
1435 static int pppol2tp_session_getsockopt(struct sock *sk,
1436 struct l2tp_session *session,
1437 int optname, int *val)
1438 {
1439 int err = 0;
1440
1441 switch (optname) {
1442 case PPPOL2TP_SO_RECVSEQ:
1443 *val = session->recv_seq;
1444 l2tp_info(session, L2TP_MSG_CONTROL,
1445 "%s: get recv_seq=%d\n", session->name, *val);
1446 break;
1447
1448 case PPPOL2TP_SO_SENDSEQ:
1449 *val = session->send_seq;
1450 l2tp_info(session, L2TP_MSG_CONTROL,
1451 "%s: get send_seq=%d\n", session->name, *val);
1452 break;
1453
1454 case PPPOL2TP_SO_LNSMODE:
1455 *val = session->lns_mode;
1456 l2tp_info(session, L2TP_MSG_CONTROL,
1457 "%s: get lns_mode=%d\n", session->name, *val);
1458 break;
1459
1460 case PPPOL2TP_SO_DEBUG:
1461 *val = session->debug;
1462 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get debug=%d\n",
1463 session->name, *val);
1464 break;
1465
1466 case PPPOL2TP_SO_REORDERTO:
1467 *val = (int) jiffies_to_msecs(session->reorder_timeout);
1468 l2tp_info(session, L2TP_MSG_CONTROL,
1469 "%s: get reorder_timeout=%d\n", session->name, *val);
1470 break;
1471
1472 default:
1473 err = -ENOPROTOOPT;
1474 }
1475
1476 return err;
1477 }
1478
1479 /* Main getsockopt() entry point.
1480 * Does API checks, then calls either the tunnel or session getsockopt
1481 * handler, according to whether the PPPoX socket is a for a regular session
1482 * or the special tunnel type.
1483 */
1484 static int pppol2tp_getsockopt(struct socket *sock, int level, int optname,
1485 char __user *optval, int __user *optlen)
1486 {
1487 struct sock *sk = sock->sk;
1488 struct l2tp_session *session;
1489 struct l2tp_tunnel *tunnel;
1490 int val, len;
1491 int err;
1492
1493 if (level != SOL_PPPOL2TP)
1494 return -EINVAL;
1495
1496 if (get_user(len, optlen))
1497 return -EFAULT;
1498
1499 len = min_t(unsigned int, len, sizeof(int));
1500
1501 if (len < 0)
1502 return -EINVAL;
1503
1504 err = -ENOTCONN;
1505 if (sk->sk_user_data == NULL)
1506 goto end;
1507
1508 /* Get the session context */
1509 err = -EBADF;
1510 session = pppol2tp_sock_to_session(sk);
1511 if (session == NULL)
1512 goto end;
1513
1514 /* Special case: if session_id == 0x0000, treat as operation on tunnel */
1515 if ((session->session_id == 0) &&
1516 (session->peer_session_id == 0)) {
1517 tunnel = session->tunnel;
1518 err = pppol2tp_tunnel_getsockopt(sk, tunnel, optname, &val);
1519 if (err)
1520 goto end_put_sess;
1521 } else {
1522 err = pppol2tp_session_getsockopt(sk, session, optname, &val);
1523 if (err)
1524 goto end_put_sess;
1525 }
1526
1527 err = -EFAULT;
1528 if (put_user(len, optlen))
1529 goto end_put_sess;
1530
1531 if (copy_to_user((void __user *) optval, &val, len))
1532 goto end_put_sess;
1533
1534 err = 0;
1535
1536 end_put_sess:
1537 sock_put(sk);
1538 end:
1539 return err;
1540 }
1541
1542 /*****************************************************************************
1543 * /proc filesystem for debug
1544 * Since the original pppol2tp driver provided /proc/net/pppol2tp for
1545 * L2TPv2, we dump only L2TPv2 tunnels and sessions here.
1546 *****************************************************************************/
1547
1548 static unsigned int pppol2tp_net_id;
1549
1550 #ifdef CONFIG_PROC_FS
1551
1552 struct pppol2tp_seq_data {
1553 struct seq_net_private p;
1554 int tunnel_idx; /* current tunnel */
1555 int session_idx; /* index of session within current tunnel */
1556 struct l2tp_tunnel *tunnel;
1557 struct l2tp_session *session; /* NULL means get next tunnel */
1558 };
1559
1560 static void pppol2tp_next_tunnel(struct net *net, struct pppol2tp_seq_data *pd)
1561 {
1562 /* Drop reference taken during previous invocation */
1563 if (pd->tunnel)
1564 l2tp_tunnel_dec_refcount(pd->tunnel);
1565
1566 for (;;) {
1567 pd->tunnel = l2tp_tunnel_get_nth(net, pd->tunnel_idx);
1568 pd->tunnel_idx++;
1569
1570 /* Only accept L2TPv2 tunnels */
1571 if (!pd->tunnel || pd->tunnel->version == 2)
1572 return;
1573
1574 l2tp_tunnel_dec_refcount(pd->tunnel);
1575 }
1576 }
1577
1578 static void pppol2tp_next_session(struct net *net, struct pppol2tp_seq_data *pd)
1579 {
1580 pd->session = l2tp_session_get_nth(pd->tunnel, pd->session_idx);
1581 pd->session_idx++;
1582
1583 if (pd->session == NULL) {
1584 pd->session_idx = 0;
1585 pppol2tp_next_tunnel(net, pd);
1586 }
1587 }
1588
1589 static void *pppol2tp_seq_start(struct seq_file *m, loff_t *offs)
1590 {
1591 struct pppol2tp_seq_data *pd = SEQ_START_TOKEN;
1592 loff_t pos = *offs;
1593 struct net *net;
1594
1595 if (!pos)
1596 goto out;
1597
1598 BUG_ON(m->private == NULL);
1599 pd = m->private;
1600 net = seq_file_net(m);
1601
1602 if (pd->tunnel == NULL)
1603 pppol2tp_next_tunnel(net, pd);
1604 else
1605 pppol2tp_next_session(net, pd);
1606
1607 /* NULL tunnel and session indicates end of list */
1608 if ((pd->tunnel == NULL) && (pd->session == NULL))
1609 pd = NULL;
1610
1611 out:
1612 return pd;
1613 }
1614
1615 static void *pppol2tp_seq_next(struct seq_file *m, void *v, loff_t *pos)
1616 {
1617 (*pos)++;
1618 return NULL;
1619 }
1620
1621 static void pppol2tp_seq_stop(struct seq_file *p, void *v)
1622 {
1623 struct pppol2tp_seq_data *pd = v;
1624
1625 if (!pd || pd == SEQ_START_TOKEN)
1626 return;
1627
1628 /* Drop reference taken by last invocation of pppol2tp_next_tunnel() */
1629 if (pd->tunnel) {
1630 l2tp_tunnel_dec_refcount(pd->tunnel);
1631 pd->tunnel = NULL;
1632 pd->session = NULL;
1633 }
1634 }
1635
1636 static void pppol2tp_seq_tunnel_show(struct seq_file *m, void *v)
1637 {
1638 struct l2tp_tunnel *tunnel = v;
1639
1640 seq_printf(m, "\nTUNNEL '%s', %c %d\n",
1641 tunnel->name,
1642 (tunnel == tunnel->sock->sk_user_data) ? 'Y' : 'N',
1643 refcount_read(&tunnel->ref_count) - 1);
1644 seq_printf(m, " %08x %ld/%ld/%ld %ld/%ld/%ld\n",
1645 tunnel->debug,
1646 atomic_long_read(&tunnel->stats.tx_packets),
1647 atomic_long_read(&tunnel->stats.tx_bytes),
1648 atomic_long_read(&tunnel->stats.tx_errors),
1649 atomic_long_read(&tunnel->stats.rx_packets),
1650 atomic_long_read(&tunnel->stats.rx_bytes),
1651 atomic_long_read(&tunnel->stats.rx_errors));
1652 }
1653
1654 static void pppol2tp_seq_session_show(struct seq_file *m, void *v)
1655 {
1656 struct l2tp_session *session = v;
1657 struct l2tp_tunnel *tunnel = session->tunnel;
1658 unsigned char state;
1659 char user_data_ok;
1660 struct sock *sk;
1661 u32 ip = 0;
1662 u16 port = 0;
1663
1664 if (tunnel->sock) {
1665 struct inet_sock *inet = inet_sk(tunnel->sock);
1666 ip = ntohl(inet->inet_saddr);
1667 port = ntohs(inet->inet_sport);
1668 }
1669
1670 sk = pppol2tp_session_get_sock(session);
1671 if (sk) {
1672 state = sk->sk_state;
1673 user_data_ok = (session == sk->sk_user_data) ? 'Y' : 'N';
1674 } else {
1675 state = 0;
1676 user_data_ok = 'N';
1677 }
1678
1679 seq_printf(m, " SESSION '%s' %08X/%d %04X/%04X -> "
1680 "%04X/%04X %d %c\n",
1681 session->name, ip, port,
1682 tunnel->tunnel_id,
1683 session->session_id,
1684 tunnel->peer_tunnel_id,
1685 session->peer_session_id,
1686 state, user_data_ok);
1687 seq_printf(m, " %d/%d/%c/%c/%s %08x %u\n",
1688 session->mtu, session->mru,
1689 session->recv_seq ? 'R' : '-',
1690 session->send_seq ? 'S' : '-',
1691 session->lns_mode ? "LNS" : "LAC",
1692 session->debug,
1693 jiffies_to_msecs(session->reorder_timeout));
1694 seq_printf(m, " %hu/%hu %ld/%ld/%ld %ld/%ld/%ld\n",
1695 session->nr, session->ns,
1696 atomic_long_read(&session->stats.tx_packets),
1697 atomic_long_read(&session->stats.tx_bytes),
1698 atomic_long_read(&session->stats.tx_errors),
1699 atomic_long_read(&session->stats.rx_packets),
1700 atomic_long_read(&session->stats.rx_bytes),
1701 atomic_long_read(&session->stats.rx_errors));
1702
1703 if (sk) {
1704 struct pppox_sock *po = pppox_sk(sk);
1705
1706 seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan));
1707 sock_put(sk);
1708 }
1709 }
1710
1711 static int pppol2tp_seq_show(struct seq_file *m, void *v)
1712 {
1713 struct pppol2tp_seq_data *pd = v;
1714
1715 /* display header on line 1 */
1716 if (v == SEQ_START_TOKEN) {
1717 seq_puts(m, "PPPoL2TP driver info, " PPPOL2TP_DRV_VERSION "\n");
1718 seq_puts(m, "TUNNEL name, user-data-ok session-count\n");
1719 seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
1720 seq_puts(m, " SESSION name, addr/port src-tid/sid "
1721 "dest-tid/sid state user-data-ok\n");
1722 seq_puts(m, " mtu/mru/rcvseq/sendseq/lns debug reorderto\n");
1723 seq_puts(m, " nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
1724 goto out;
1725 }
1726
1727 /* Show the tunnel or session context.
1728 */
1729 if (!pd->session) {
1730 pppol2tp_seq_tunnel_show(m, pd->tunnel);
1731 } else {
1732 pppol2tp_seq_session_show(m, pd->session);
1733 l2tp_session_dec_refcount(pd->session);
1734 }
1735
1736 out:
1737 return 0;
1738 }
1739
1740 static const struct seq_operations pppol2tp_seq_ops = {
1741 .start = pppol2tp_seq_start,
1742 .next = pppol2tp_seq_next,
1743 .stop = pppol2tp_seq_stop,
1744 .show = pppol2tp_seq_show,
1745 };
1746
1747 /* Called when our /proc file is opened. We allocate data for use when
1748 * iterating our tunnel / session contexts and store it in the private
1749 * data of the seq_file.
1750 */
1751 static int pppol2tp_proc_open(struct inode *inode, struct file *file)
1752 {
1753 return seq_open_net(inode, file, &pppol2tp_seq_ops,
1754 sizeof(struct pppol2tp_seq_data));
1755 }
1756
1757 static const struct file_operations pppol2tp_proc_fops = {
1758 .open = pppol2tp_proc_open,
1759 .read = seq_read,
1760 .llseek = seq_lseek,
1761 .release = seq_release_net,
1762 };
1763
1764 #endif /* CONFIG_PROC_FS */
1765
1766 /*****************************************************************************
1767 * Network namespace
1768 *****************************************************************************/
1769
1770 static __net_init int pppol2tp_init_net(struct net *net)
1771 {
1772 struct proc_dir_entry *pde;
1773 int err = 0;
1774
1775 pde = proc_create("pppol2tp", S_IRUGO, net->proc_net,
1776 &pppol2tp_proc_fops);
1777 if (!pde) {
1778 err = -ENOMEM;
1779 goto out;
1780 }
1781
1782 out:
1783 return err;
1784 }
1785
1786 static __net_exit void pppol2tp_exit_net(struct net *net)
1787 {
1788 remove_proc_entry("pppol2tp", net->proc_net);
1789 }
1790
1791 static struct pernet_operations pppol2tp_net_ops = {
1792 .init = pppol2tp_init_net,
1793 .exit = pppol2tp_exit_net,
1794 .id = &pppol2tp_net_id,
1795 };
1796
1797 /*****************************************************************************
1798 * Init and cleanup
1799 *****************************************************************************/
1800
1801 static const struct proto_ops pppol2tp_ops = {
1802 .family = AF_PPPOX,
1803 .owner = THIS_MODULE,
1804 .release = pppol2tp_release,
1805 .bind = sock_no_bind,
1806 .connect = pppol2tp_connect,
1807 .socketpair = sock_no_socketpair,
1808 .accept = sock_no_accept,
1809 .getname = pppol2tp_getname,
1810 .poll = datagram_poll,
1811 .listen = sock_no_listen,
1812 .shutdown = sock_no_shutdown,
1813 .setsockopt = pppol2tp_setsockopt,
1814 .getsockopt = pppol2tp_getsockopt,
1815 .sendmsg = pppol2tp_sendmsg,
1816 .recvmsg = pppol2tp_recvmsg,
1817 .mmap = sock_no_mmap,
1818 .ioctl = pppox_ioctl,
1819 };
1820
1821 static const struct pppox_proto pppol2tp_proto = {
1822 .create = pppol2tp_create,
1823 .ioctl = pppol2tp_ioctl,
1824 .owner = THIS_MODULE,
1825 };
1826
1827 #ifdef CONFIG_L2TP_V3
1828
1829 static const struct l2tp_nl_cmd_ops pppol2tp_nl_cmd_ops = {
1830 .session_create = pppol2tp_session_create,
1831 .session_delete = l2tp_session_delete,
1832 };
1833
1834 #endif /* CONFIG_L2TP_V3 */
1835
1836 static int __init pppol2tp_init(void)
1837 {
1838 int err;
1839
1840 err = register_pernet_device(&pppol2tp_net_ops);
1841 if (err)
1842 goto out;
1843
1844 err = proto_register(&pppol2tp_sk_proto, 0);
1845 if (err)
1846 goto out_unregister_pppol2tp_pernet;
1847
1848 err = register_pppox_proto(PX_PROTO_OL2TP, &pppol2tp_proto);
1849 if (err)
1850 goto out_unregister_pppol2tp_proto;
1851
1852 #ifdef CONFIG_L2TP_V3
1853 err = l2tp_nl_register_ops(L2TP_PWTYPE_PPP, &pppol2tp_nl_cmd_ops);
1854 if (err)
1855 goto out_unregister_pppox;
1856 #endif
1857
1858 pr_info("PPPoL2TP kernel driver, %s\n", PPPOL2TP_DRV_VERSION);
1859
1860 out:
1861 return err;
1862
1863 #ifdef CONFIG_L2TP_V3
1864 out_unregister_pppox:
1865 unregister_pppox_proto(PX_PROTO_OL2TP);
1866 #endif
1867 out_unregister_pppol2tp_proto:
1868 proto_unregister(&pppol2tp_sk_proto);
1869 out_unregister_pppol2tp_pernet:
1870 unregister_pernet_device(&pppol2tp_net_ops);
1871 goto out;
1872 }
1873
1874 static void __exit pppol2tp_exit(void)
1875 {
1876 #ifdef CONFIG_L2TP_V3
1877 l2tp_nl_unregister_ops(L2TP_PWTYPE_PPP);
1878 #endif
1879 unregister_pppox_proto(PX_PROTO_OL2TP);
1880 proto_unregister(&pppol2tp_sk_proto);
1881 unregister_pernet_device(&pppol2tp_net_ops);
1882 }
1883
1884 module_init(pppol2tp_init);
1885 module_exit(pppol2tp_exit);
1886
1887 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
1888 MODULE_DESCRIPTION("PPP over L2TP over UDP");
1889 MODULE_LICENSE("GPL");
1890 MODULE_VERSION(PPPOL2TP_DRV_VERSION);
1891 MODULE_ALIAS_NET_PF_PROTO(PF_PPPOX, PX_PROTO_OL2TP);
1892 MODULE_ALIAS_L2TP_PWTYPE(7);
Linux with added FPC-III support