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l2tp: take reference on sessions being dumped
[mirror_ubuntu-bionic-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 sock *sock; /* Pointer to the session
126 * PPPoX socket */
127 struct sock *tunnel_sock; /* Pointer to the tunnel UDP
128 * socket */
129 int flags; /* accessed by PPPIOCGFLAGS.
130 * Unused. */
131 };
132
133 static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb);
134
135 static const struct ppp_channel_ops pppol2tp_chan_ops = {
136 .start_xmit = pppol2tp_xmit,
137 };
138
139 static const struct proto_ops pppol2tp_ops;
140
141 /* Helpers to obtain tunnel/session contexts from sockets.
142 */
143 static inline struct l2tp_session *pppol2tp_sock_to_session(struct sock *sk)
144 {
145 struct l2tp_session *session;
146
147 if (sk == NULL)
148 return NULL;
149
150 sock_hold(sk);
151 session = (struct l2tp_session *)(sk->sk_user_data);
152 if (session == NULL) {
153 sock_put(sk);
154 goto out;
155 }
156
157 BUG_ON(session->magic != L2TP_SESSION_MAGIC);
158
159 out:
160 return session;
161 }
162
163 /*****************************************************************************
164 * Receive data handling
165 *****************************************************************************/
166
167 static int pppol2tp_recv_payload_hook(struct sk_buff *skb)
168 {
169 /* Skip PPP header, if present. In testing, Microsoft L2TP clients
170 * don't send the PPP header (PPP header compression enabled), but
171 * other clients can include the header. So we cope with both cases
172 * here. The PPP header is always FF03 when using L2TP.
173 *
174 * Note that skb->data[] isn't dereferenced from a u16 ptr here since
175 * the field may be unaligned.
176 */
177 if (!pskb_may_pull(skb, 2))
178 return 1;
179
180 if ((skb->data[0] == PPP_ALLSTATIONS) && (skb->data[1] == PPP_UI))
181 skb_pull(skb, 2);
182
183 return 0;
184 }
185
186 /* Receive message. This is the recvmsg for the PPPoL2TP socket.
187 */
188 static int pppol2tp_recvmsg(struct socket *sock, struct msghdr *msg,
189 size_t len, int flags)
190 {
191 int err;
192 struct sk_buff *skb;
193 struct sock *sk = sock->sk;
194
195 err = -EIO;
196 if (sk->sk_state & PPPOX_BOUND)
197 goto end;
198
199 err = 0;
200 skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
201 flags & MSG_DONTWAIT, &err);
202 if (!skb)
203 goto end;
204
205 if (len > skb->len)
206 len = skb->len;
207 else if (len < skb->len)
208 msg->msg_flags |= MSG_TRUNC;
209
210 err = skb_copy_datagram_msg(skb, 0, msg, len);
211 if (likely(err == 0))
212 err = len;
213
214 kfree_skb(skb);
215 end:
216 return err;
217 }
218
219 static void pppol2tp_recv(struct l2tp_session *session, struct sk_buff *skb, int data_len)
220 {
221 struct pppol2tp_session *ps = l2tp_session_priv(session);
222 struct sock *sk = NULL;
223
224 /* If the socket is bound, send it in to PPP's input queue. Otherwise
225 * queue it on the session socket.
226 */
227 sk = ps->sock;
228 if (sk == NULL)
229 goto no_sock;
230
231 if (sk->sk_state & PPPOX_BOUND) {
232 struct pppox_sock *po;
233
234 l2tp_dbg(session, L2TP_MSG_DATA,
235 "%s: recv %d byte data frame, passing to ppp\n",
236 session->name, data_len);
237
238 po = pppox_sk(sk);
239 ppp_input(&po->chan, skb);
240 } else {
241 l2tp_dbg(session, L2TP_MSG_DATA,
242 "%s: recv %d byte data frame, passing to L2TP socket\n",
243 session->name, data_len);
244
245 if (sock_queue_rcv_skb(sk, skb) < 0) {
246 atomic_long_inc(&session->stats.rx_errors);
247 kfree_skb(skb);
248 }
249 }
250
251 return;
252
253 no_sock:
254 l2tp_info(session, L2TP_MSG_DATA, "%s: no socket\n", session->name);
255 kfree_skb(skb);
256 }
257
258 static void pppol2tp_session_sock_hold(struct l2tp_session *session)
259 {
260 struct pppol2tp_session *ps = l2tp_session_priv(session);
261
262 if (ps->sock)
263 sock_hold(ps->sock);
264 }
265
266 static void pppol2tp_session_sock_put(struct l2tp_session *session)
267 {
268 struct pppol2tp_session *ps = l2tp_session_priv(session);
269
270 if (ps->sock)
271 sock_put(ps->sock);
272 }
273
274 /************************************************************************
275 * Transmit handling
276 ***********************************************************************/
277
278 /* This is the sendmsg for the PPPoL2TP pppol2tp_session socket. We come here
279 * when a user application does a sendmsg() on the session socket. L2TP and
280 * PPP headers must be inserted into the user's data.
281 */
282 static int pppol2tp_sendmsg(struct socket *sock, struct msghdr *m,
283 size_t total_len)
284 {
285 struct sock *sk = sock->sk;
286 struct sk_buff *skb;
287 int error;
288 struct l2tp_session *session;
289 struct l2tp_tunnel *tunnel;
290 struct pppol2tp_session *ps;
291 int uhlen;
292
293 error = -ENOTCONN;
294 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
295 goto error;
296
297 /* Get session and tunnel contexts */
298 error = -EBADF;
299 session = pppol2tp_sock_to_session(sk);
300 if (session == NULL)
301 goto error;
302
303 ps = l2tp_session_priv(session);
304 tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock);
305 if (tunnel == NULL)
306 goto error_put_sess;
307
308 uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0;
309
310 /* Allocate a socket buffer */
311 error = -ENOMEM;
312 skb = sock_wmalloc(sk, NET_SKB_PAD + sizeof(struct iphdr) +
313 uhlen + session->hdr_len +
314 2 + total_len, /* 2 bytes for PPP_ALLSTATIONS & PPP_UI */
315 0, GFP_KERNEL);
316 if (!skb)
317 goto error_put_sess_tun;
318
319 /* Reserve space for headers. */
320 skb_reserve(skb, NET_SKB_PAD);
321 skb_reset_network_header(skb);
322 skb_reserve(skb, sizeof(struct iphdr));
323 skb_reset_transport_header(skb);
324 skb_reserve(skb, uhlen);
325
326 /* Add PPP header */
327 skb->data[0] = PPP_ALLSTATIONS;
328 skb->data[1] = PPP_UI;
329 skb_put(skb, 2);
330
331 /* Copy user data into skb */
332 error = memcpy_from_msg(skb_put(skb, total_len), m, total_len);
333 if (error < 0) {
334 kfree_skb(skb);
335 goto error_put_sess_tun;
336 }
337
338 local_bh_disable();
339 l2tp_xmit_skb(session, skb, session->hdr_len);
340 local_bh_enable();
341
342 sock_put(ps->tunnel_sock);
343 sock_put(sk);
344
345 return total_len;
346
347 error_put_sess_tun:
348 sock_put(ps->tunnel_sock);
349 error_put_sess:
350 sock_put(sk);
351 error:
352 return error;
353 }
354
355 /* Transmit function called by generic PPP driver. Sends PPP frame
356 * over PPPoL2TP socket.
357 *
358 * This is almost the same as pppol2tp_sendmsg(), but rather than
359 * being called with a msghdr from userspace, it is called with a skb
360 * from the kernel.
361 *
362 * The supplied skb from ppp doesn't have enough headroom for the
363 * insertion of L2TP, UDP and IP headers so we need to allocate more
364 * headroom in the skb. This will create a cloned skb. But we must be
365 * careful in the error case because the caller will expect to free
366 * the skb it supplied, not our cloned skb. So we take care to always
367 * leave the original skb unfreed if we return an error.
368 */
369 static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
370 {
371 struct sock *sk = (struct sock *) chan->private;
372 struct sock *sk_tun;
373 struct l2tp_session *session;
374 struct l2tp_tunnel *tunnel;
375 struct pppol2tp_session *ps;
376 int uhlen, headroom;
377
378 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
379 goto abort;
380
381 /* Get session and tunnel contexts from the socket */
382 session = pppol2tp_sock_to_session(sk);
383 if (session == NULL)
384 goto abort;
385
386 ps = l2tp_session_priv(session);
387 sk_tun = ps->tunnel_sock;
388 if (sk_tun == NULL)
389 goto abort_put_sess;
390 tunnel = l2tp_sock_to_tunnel(sk_tun);
391 if (tunnel == NULL)
392 goto abort_put_sess;
393
394 uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0;
395 headroom = NET_SKB_PAD +
396 sizeof(struct iphdr) + /* IP header */
397 uhlen + /* UDP header (if L2TP_ENCAPTYPE_UDP) */
398 session->hdr_len + /* L2TP header */
399 2; /* 2 bytes for PPP_ALLSTATIONS & PPP_UI */
400 if (skb_cow_head(skb, headroom))
401 goto abort_put_sess_tun;
402
403 /* Setup PPP header */
404 __skb_push(skb, 2);
405 skb->data[0] = PPP_ALLSTATIONS;
406 skb->data[1] = PPP_UI;
407
408 local_bh_disable();
409 l2tp_xmit_skb(session, skb, session->hdr_len);
410 local_bh_enable();
411
412 sock_put(sk_tun);
413 sock_put(sk);
414 return 1;
415
416 abort_put_sess_tun:
417 sock_put(sk_tun);
418 abort_put_sess:
419 sock_put(sk);
420 abort:
421 /* Free the original skb */
422 kfree_skb(skb);
423 return 1;
424 }
425
426 /*****************************************************************************
427 * Session (and tunnel control) socket create/destroy.
428 *****************************************************************************/
429
430 /* Called by l2tp_core when a session socket is being closed.
431 */
432 static void pppol2tp_session_close(struct l2tp_session *session)
433 {
434 struct pppol2tp_session *ps = l2tp_session_priv(session);
435 struct sock *sk = ps->sock;
436 struct socket *sock = sk->sk_socket;
437
438 BUG_ON(session->magic != L2TP_SESSION_MAGIC);
439
440 if (sock) {
441 inet_shutdown(sock, SEND_SHUTDOWN);
442 /* Don't let the session go away before our socket does */
443 l2tp_session_inc_refcount(session);
444 }
445 }
446
447 /* Really kill the session socket. (Called from sock_put() if
448 * refcnt == 0.)
449 */
450 static void pppol2tp_session_destruct(struct sock *sk)
451 {
452 struct l2tp_session *session = sk->sk_user_data;
453
454 skb_queue_purge(&sk->sk_receive_queue);
455 skb_queue_purge(&sk->sk_write_queue);
456
457 if (session) {
458 sk->sk_user_data = NULL;
459 BUG_ON(session->magic != L2TP_SESSION_MAGIC);
460 l2tp_session_dec_refcount(session);
461 }
462 }
463
464 /* Called when the PPPoX socket (session) is closed.
465 */
466 static int pppol2tp_release(struct socket *sock)
467 {
468 struct sock *sk = sock->sk;
469 struct l2tp_session *session;
470 int error;
471
472 if (!sk)
473 return 0;
474
475 error = -EBADF;
476 lock_sock(sk);
477 if (sock_flag(sk, SOCK_DEAD) != 0)
478 goto error;
479
480 pppox_unbind_sock(sk);
481
482 /* Signal the death of the socket. */
483 sk->sk_state = PPPOX_DEAD;
484 sock_orphan(sk);
485 sock->sk = NULL;
486
487 session = pppol2tp_sock_to_session(sk);
488
489 /* Purge any queued data */
490 if (session != NULL) {
491 __l2tp_session_unhash(session);
492 l2tp_session_queue_purge(session);
493 sock_put(sk);
494 }
495 release_sock(sk);
496
497 /* This will delete the session context via
498 * pppol2tp_session_destruct() if the socket's refcnt drops to
499 * zero.
500 */
501 sock_put(sk);
502
503 return 0;
504
505 error:
506 release_sock(sk);
507 return error;
508 }
509
510 static struct proto pppol2tp_sk_proto = {
511 .name = "PPPOL2TP",
512 .owner = THIS_MODULE,
513 .obj_size = sizeof(struct pppox_sock),
514 };
515
516 static int pppol2tp_backlog_recv(struct sock *sk, struct sk_buff *skb)
517 {
518 int rc;
519
520 rc = l2tp_udp_encap_recv(sk, skb);
521 if (rc)
522 kfree_skb(skb);
523
524 return NET_RX_SUCCESS;
525 }
526
527 /* socket() handler. Initialize a new struct sock.
528 */
529 static int pppol2tp_create(struct net *net, struct socket *sock, int kern)
530 {
531 int error = -ENOMEM;
532 struct sock *sk;
533
534 sk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, &pppol2tp_sk_proto, kern);
535 if (!sk)
536 goto out;
537
538 sock_init_data(sock, sk);
539
540 sock->state = SS_UNCONNECTED;
541 sock->ops = &pppol2tp_ops;
542
543 sk->sk_backlog_rcv = pppol2tp_backlog_recv;
544 sk->sk_protocol = PX_PROTO_OL2TP;
545 sk->sk_family = PF_PPPOX;
546 sk->sk_state = PPPOX_NONE;
547 sk->sk_type = SOCK_STREAM;
548 sk->sk_destruct = pppol2tp_session_destruct;
549
550 error = 0;
551
552 out:
553 return error;
554 }
555
556 #if IS_ENABLED(CONFIG_L2TP_DEBUGFS)
557 static void pppol2tp_show(struct seq_file *m, void *arg)
558 {
559 struct l2tp_session *session = arg;
560 struct pppol2tp_session *ps = l2tp_session_priv(session);
561
562 if (ps) {
563 struct pppox_sock *po = pppox_sk(ps->sock);
564 if (po)
565 seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan));
566 }
567 }
568 #endif
569
570 /* connect() handler. Attach a PPPoX socket to a tunnel UDP socket
571 */
572 static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr,
573 int sockaddr_len, int flags)
574 {
575 struct sock *sk = sock->sk;
576 struct sockaddr_pppol2tp *sp = (struct sockaddr_pppol2tp *) uservaddr;
577 struct pppox_sock *po = pppox_sk(sk);
578 struct l2tp_session *session = NULL;
579 struct l2tp_tunnel *tunnel;
580 struct pppol2tp_session *ps;
581 struct dst_entry *dst;
582 struct l2tp_session_cfg cfg = { 0, };
583 int error = 0;
584 u32 tunnel_id, peer_tunnel_id;
585 u32 session_id, peer_session_id;
586 bool drop_refcnt = false;
587 int ver = 2;
588 int fd;
589
590 lock_sock(sk);
591
592 error = -EINVAL;
593 if (sp->sa_protocol != PX_PROTO_OL2TP)
594 goto end;
595
596 /* Check for already bound sockets */
597 error = -EBUSY;
598 if (sk->sk_state & PPPOX_CONNECTED)
599 goto end;
600
601 /* We don't supporting rebinding anyway */
602 error = -EALREADY;
603 if (sk->sk_user_data)
604 goto end; /* socket is already attached */
605
606 /* Get params from socket address. Handle L2TPv2 and L2TPv3.
607 * This is nasty because there are different sockaddr_pppol2tp
608 * structs for L2TPv2, L2TPv3, over IPv4 and IPv6. We use
609 * the sockaddr size to determine which structure the caller
610 * is using.
611 */
612 peer_tunnel_id = 0;
613 if (sockaddr_len == sizeof(struct sockaddr_pppol2tp)) {
614 fd = sp->pppol2tp.fd;
615 tunnel_id = sp->pppol2tp.s_tunnel;
616 peer_tunnel_id = sp->pppol2tp.d_tunnel;
617 session_id = sp->pppol2tp.s_session;
618 peer_session_id = sp->pppol2tp.d_session;
619 } else if (sockaddr_len == sizeof(struct sockaddr_pppol2tpv3)) {
620 struct sockaddr_pppol2tpv3 *sp3 =
621 (struct sockaddr_pppol2tpv3 *) sp;
622 ver = 3;
623 fd = sp3->pppol2tp.fd;
624 tunnel_id = sp3->pppol2tp.s_tunnel;
625 peer_tunnel_id = sp3->pppol2tp.d_tunnel;
626 session_id = sp3->pppol2tp.s_session;
627 peer_session_id = sp3->pppol2tp.d_session;
628 } else if (sockaddr_len == sizeof(struct sockaddr_pppol2tpin6)) {
629 struct sockaddr_pppol2tpin6 *sp6 =
630 (struct sockaddr_pppol2tpin6 *) sp;
631 fd = sp6->pppol2tp.fd;
632 tunnel_id = sp6->pppol2tp.s_tunnel;
633 peer_tunnel_id = sp6->pppol2tp.d_tunnel;
634 session_id = sp6->pppol2tp.s_session;
635 peer_session_id = sp6->pppol2tp.d_session;
636 } else if (sockaddr_len == sizeof(struct sockaddr_pppol2tpv3in6)) {
637 struct sockaddr_pppol2tpv3in6 *sp6 =
638 (struct sockaddr_pppol2tpv3in6 *) sp;
639 ver = 3;
640 fd = sp6->pppol2tp.fd;
641 tunnel_id = sp6->pppol2tp.s_tunnel;
642 peer_tunnel_id = sp6->pppol2tp.d_tunnel;
643 session_id = sp6->pppol2tp.s_session;
644 peer_session_id = sp6->pppol2tp.d_session;
645 } else {
646 error = -EINVAL;
647 goto end; /* bad socket address */
648 }
649
650 /* Don't bind if tunnel_id is 0 */
651 error = -EINVAL;
652 if (tunnel_id == 0)
653 goto end;
654
655 tunnel = l2tp_tunnel_find(sock_net(sk), tunnel_id);
656
657 /* Special case: create tunnel context if session_id and
658 * peer_session_id is 0. Otherwise look up tunnel using supplied
659 * tunnel id.
660 */
661 if ((session_id == 0) && (peer_session_id == 0)) {
662 if (tunnel == NULL) {
663 struct l2tp_tunnel_cfg tcfg = {
664 .encap = L2TP_ENCAPTYPE_UDP,
665 .debug = 0,
666 };
667 error = l2tp_tunnel_create(sock_net(sk), fd, ver, tunnel_id, peer_tunnel_id, &tcfg, &tunnel);
668 if (error < 0)
669 goto end;
670 }
671 } else {
672 /* Error if we can't find the tunnel */
673 error = -ENOENT;
674 if (tunnel == NULL)
675 goto end;
676
677 /* Error if socket is not prepped */
678 if (tunnel->sock == NULL)
679 goto end;
680 }
681
682 if (tunnel->recv_payload_hook == NULL)
683 tunnel->recv_payload_hook = pppol2tp_recv_payload_hook;
684
685 if (tunnel->peer_tunnel_id == 0)
686 tunnel->peer_tunnel_id = peer_tunnel_id;
687
688 session = l2tp_session_get(sock_net(sk), tunnel, session_id, false);
689 if (session) {
690 drop_refcnt = true;
691 ps = l2tp_session_priv(session);
692
693 /* Using a pre-existing session is fine as long as it hasn't
694 * been connected yet.
695 */
696 if (ps->sock) {
697 error = -EEXIST;
698 goto end;
699 }
700
701 /* consistency checks */
702 if (ps->tunnel_sock != tunnel->sock) {
703 error = -EEXIST;
704 goto end;
705 }
706 } else {
707 /* Default MTU must allow space for UDP/L2TP/PPP headers */
708 cfg.mtu = 1500 - PPPOL2TP_HEADER_OVERHEAD;
709 cfg.mru = cfg.mtu;
710
711 session = l2tp_session_create(sizeof(struct pppol2tp_session),
712 tunnel, session_id,
713 peer_session_id, &cfg);
714 if (IS_ERR(session)) {
715 error = PTR_ERR(session);
716 goto end;
717 }
718 }
719
720 /* Associate session with its PPPoL2TP socket */
721 ps = l2tp_session_priv(session);
722 ps->owner = current->pid;
723 ps->sock = sk;
724 ps->tunnel_sock = tunnel->sock;
725
726 session->recv_skb = pppol2tp_recv;
727 session->session_close = pppol2tp_session_close;
728 #if IS_ENABLED(CONFIG_L2TP_DEBUGFS)
729 session->show = pppol2tp_show;
730 #endif
731
732 /* We need to know each time a skb is dropped from the reorder
733 * queue.
734 */
735 session->ref = pppol2tp_session_sock_hold;
736 session->deref = pppol2tp_session_sock_put;
737
738 /* If PMTU discovery was enabled, use the MTU that was discovered */
739 dst = sk_dst_get(tunnel->sock);
740 if (dst != NULL) {
741 u32 pmtu = dst_mtu(dst);
742
743 if (pmtu != 0)
744 session->mtu = session->mru = pmtu -
745 PPPOL2TP_HEADER_OVERHEAD;
746 dst_release(dst);
747 }
748
749 /* Special case: if source & dest session_id == 0x0000, this
750 * socket is being created to manage the tunnel. Just set up
751 * the internal context for use by ioctl() and sockopt()
752 * handlers.
753 */
754 if ((session->session_id == 0) &&
755 (session->peer_session_id == 0)) {
756 error = 0;
757 goto out_no_ppp;
758 }
759
760 /* The only header we need to worry about is the L2TP
761 * header. This size is different depending on whether
762 * sequence numbers are enabled for the data channel.
763 */
764 po->chan.hdrlen = PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
765
766 po->chan.private = sk;
767 po->chan.ops = &pppol2tp_chan_ops;
768 po->chan.mtu = session->mtu;
769
770 error = ppp_register_net_channel(sock_net(sk), &po->chan);
771 if (error)
772 goto end;
773
774 out_no_ppp:
775 /* This is how we get the session context from the socket. */
776 sk->sk_user_data = session;
777 sk->sk_state = PPPOX_CONNECTED;
778 l2tp_info(session, L2TP_MSG_CONTROL, "%s: created\n",
779 session->name);
780
781 end:
782 if (drop_refcnt)
783 l2tp_session_dec_refcount(session);
784 release_sock(sk);
785
786 return error;
787 }
788
789 #ifdef CONFIG_L2TP_V3
790
791 /* Called when creating sessions via the netlink interface.
792 */
793 static int pppol2tp_session_create(struct net *net, u32 tunnel_id, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg)
794 {
795 int error;
796 struct l2tp_tunnel *tunnel;
797 struct l2tp_session *session;
798 struct pppol2tp_session *ps;
799
800 tunnel = l2tp_tunnel_find(net, tunnel_id);
801
802 /* Error if we can't find the tunnel */
803 error = -ENOENT;
804 if (tunnel == NULL)
805 goto out;
806
807 /* Error if tunnel socket is not prepped */
808 if (tunnel->sock == NULL)
809 goto out;
810
811 /* Default MTU values. */
812 if (cfg->mtu == 0)
813 cfg->mtu = 1500 - PPPOL2TP_HEADER_OVERHEAD;
814 if (cfg->mru == 0)
815 cfg->mru = cfg->mtu;
816
817 /* Allocate and initialize a new session context. */
818 session = l2tp_session_create(sizeof(struct pppol2tp_session),
819 tunnel, session_id,
820 peer_session_id, cfg);
821 if (IS_ERR(session)) {
822 error = PTR_ERR(session);
823 goto out;
824 }
825
826 ps = l2tp_session_priv(session);
827 ps->tunnel_sock = tunnel->sock;
828
829 l2tp_info(session, L2TP_MSG_CONTROL, "%s: created\n",
830 session->name);
831
832 error = 0;
833
834 out:
835 return error;
836 }
837
838 #endif /* CONFIG_L2TP_V3 */
839
840 /* getname() support.
841 */
842 static int pppol2tp_getname(struct socket *sock, struct sockaddr *uaddr,
843 int *usockaddr_len, int peer)
844 {
845 int len = 0;
846 int error = 0;
847 struct l2tp_session *session;
848 struct l2tp_tunnel *tunnel;
849 struct sock *sk = sock->sk;
850 struct inet_sock *inet;
851 struct pppol2tp_session *pls;
852
853 error = -ENOTCONN;
854 if (sk == NULL)
855 goto end;
856 if (!(sk->sk_state & PPPOX_CONNECTED))
857 goto end;
858
859 error = -EBADF;
860 session = pppol2tp_sock_to_session(sk);
861 if (session == NULL)
862 goto end;
863
864 pls = l2tp_session_priv(session);
865 tunnel = l2tp_sock_to_tunnel(pls->tunnel_sock);
866 if (tunnel == NULL)
867 goto end_put_sess;
868
869 inet = inet_sk(tunnel->sock);
870 if ((tunnel->version == 2) && (tunnel->sock->sk_family == AF_INET)) {
871 struct sockaddr_pppol2tp sp;
872 len = sizeof(sp);
873 memset(&sp, 0, len);
874 sp.sa_family = AF_PPPOX;
875 sp.sa_protocol = PX_PROTO_OL2TP;
876 sp.pppol2tp.fd = tunnel->fd;
877 sp.pppol2tp.pid = pls->owner;
878 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
879 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
880 sp.pppol2tp.s_session = session->session_id;
881 sp.pppol2tp.d_session = session->peer_session_id;
882 sp.pppol2tp.addr.sin_family = AF_INET;
883 sp.pppol2tp.addr.sin_port = inet->inet_dport;
884 sp.pppol2tp.addr.sin_addr.s_addr = inet->inet_daddr;
885 memcpy(uaddr, &sp, len);
886 #if IS_ENABLED(CONFIG_IPV6)
887 } else if ((tunnel->version == 2) &&
888 (tunnel->sock->sk_family == AF_INET6)) {
889 struct sockaddr_pppol2tpin6 sp;
890
891 len = sizeof(sp);
892 memset(&sp, 0, len);
893 sp.sa_family = AF_PPPOX;
894 sp.sa_protocol = PX_PROTO_OL2TP;
895 sp.pppol2tp.fd = tunnel->fd;
896 sp.pppol2tp.pid = pls->owner;
897 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
898 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
899 sp.pppol2tp.s_session = session->session_id;
900 sp.pppol2tp.d_session = session->peer_session_id;
901 sp.pppol2tp.addr.sin6_family = AF_INET6;
902 sp.pppol2tp.addr.sin6_port = inet->inet_dport;
903 memcpy(&sp.pppol2tp.addr.sin6_addr, &tunnel->sock->sk_v6_daddr,
904 sizeof(tunnel->sock->sk_v6_daddr));
905 memcpy(uaddr, &sp, len);
906 } else if ((tunnel->version == 3) &&
907 (tunnel->sock->sk_family == AF_INET6)) {
908 struct sockaddr_pppol2tpv3in6 sp;
909
910 len = sizeof(sp);
911 memset(&sp, 0, len);
912 sp.sa_family = AF_PPPOX;
913 sp.sa_protocol = PX_PROTO_OL2TP;
914 sp.pppol2tp.fd = tunnel->fd;
915 sp.pppol2tp.pid = pls->owner;
916 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
917 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
918 sp.pppol2tp.s_session = session->session_id;
919 sp.pppol2tp.d_session = session->peer_session_id;
920 sp.pppol2tp.addr.sin6_family = AF_INET6;
921 sp.pppol2tp.addr.sin6_port = inet->inet_dport;
922 memcpy(&sp.pppol2tp.addr.sin6_addr, &tunnel->sock->sk_v6_daddr,
923 sizeof(tunnel->sock->sk_v6_daddr));
924 memcpy(uaddr, &sp, len);
925 #endif
926 } else if (tunnel->version == 3) {
927 struct sockaddr_pppol2tpv3 sp;
928 len = sizeof(sp);
929 memset(&sp, 0, len);
930 sp.sa_family = AF_PPPOX;
931 sp.sa_protocol = PX_PROTO_OL2TP;
932 sp.pppol2tp.fd = tunnel->fd;
933 sp.pppol2tp.pid = pls->owner;
934 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
935 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
936 sp.pppol2tp.s_session = session->session_id;
937 sp.pppol2tp.d_session = session->peer_session_id;
938 sp.pppol2tp.addr.sin_family = AF_INET;
939 sp.pppol2tp.addr.sin_port = inet->inet_dport;
940 sp.pppol2tp.addr.sin_addr.s_addr = inet->inet_daddr;
941 memcpy(uaddr, &sp, len);
942 }
943
944 *usockaddr_len = len;
945 error = 0;
946
947 sock_put(pls->tunnel_sock);
948 end_put_sess:
949 sock_put(sk);
950 end:
951 return error;
952 }
953
954 /****************************************************************************
955 * ioctl() handlers.
956 *
957 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
958 * sockets. However, in order to control kernel tunnel features, we allow
959 * userspace to create a special "tunnel" PPPoX socket which is used for
960 * control only. Tunnel PPPoX sockets have session_id == 0 and simply allow
961 * the user application to issue L2TP setsockopt(), getsockopt() and ioctl()
962 * calls.
963 ****************************************************************************/
964
965 static void pppol2tp_copy_stats(struct pppol2tp_ioc_stats *dest,
966 struct l2tp_stats *stats)
967 {
968 dest->tx_packets = atomic_long_read(&stats->tx_packets);
969 dest->tx_bytes = atomic_long_read(&stats->tx_bytes);
970 dest->tx_errors = atomic_long_read(&stats->tx_errors);
971 dest->rx_packets = atomic_long_read(&stats->rx_packets);
972 dest->rx_bytes = atomic_long_read(&stats->rx_bytes);
973 dest->rx_seq_discards = atomic_long_read(&stats->rx_seq_discards);
974 dest->rx_oos_packets = atomic_long_read(&stats->rx_oos_packets);
975 dest->rx_errors = atomic_long_read(&stats->rx_errors);
976 }
977
978 /* Session ioctl helper.
979 */
980 static int pppol2tp_session_ioctl(struct l2tp_session *session,
981 unsigned int cmd, unsigned long arg)
982 {
983 struct ifreq ifr;
984 int err = 0;
985 struct sock *sk;
986 int val = (int) arg;
987 struct pppol2tp_session *ps = l2tp_session_priv(session);
988 struct l2tp_tunnel *tunnel = session->tunnel;
989 struct pppol2tp_ioc_stats stats;
990
991 l2tp_dbg(session, L2TP_MSG_CONTROL,
992 "%s: pppol2tp_session_ioctl(cmd=%#x, arg=%#lx)\n",
993 session->name, cmd, arg);
994
995 sk = ps->sock;
996 sock_hold(sk);
997
998 switch (cmd) {
999 case SIOCGIFMTU:
1000 err = -ENXIO;
1001 if (!(sk->sk_state & PPPOX_CONNECTED))
1002 break;
1003
1004 err = -EFAULT;
1005 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq)))
1006 break;
1007 ifr.ifr_mtu = session->mtu;
1008 if (copy_to_user((void __user *) arg, &ifr, sizeof(struct ifreq)))
1009 break;
1010
1011 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get mtu=%d\n",
1012 session->name, session->mtu);
1013 err = 0;
1014 break;
1015
1016 case SIOCSIFMTU:
1017 err = -ENXIO;
1018 if (!(sk->sk_state & PPPOX_CONNECTED))
1019 break;
1020
1021 err = -EFAULT;
1022 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq)))
1023 break;
1024
1025 session->mtu = ifr.ifr_mtu;
1026
1027 l2tp_info(session, L2TP_MSG_CONTROL, "%s: set mtu=%d\n",
1028 session->name, session->mtu);
1029 err = 0;
1030 break;
1031
1032 case PPPIOCGMRU:
1033 err = -ENXIO;
1034 if (!(sk->sk_state & PPPOX_CONNECTED))
1035 break;
1036
1037 err = -EFAULT;
1038 if (put_user(session->mru, (int __user *) arg))
1039 break;
1040
1041 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get mru=%d\n",
1042 session->name, session->mru);
1043 err = 0;
1044 break;
1045
1046 case PPPIOCSMRU:
1047 err = -ENXIO;
1048 if (!(sk->sk_state & PPPOX_CONNECTED))
1049 break;
1050
1051 err = -EFAULT;
1052 if (get_user(val, (int __user *) arg))
1053 break;
1054
1055 session->mru = val;
1056 l2tp_info(session, L2TP_MSG_CONTROL, "%s: set mru=%d\n",
1057 session->name, session->mru);
1058 err = 0;
1059 break;
1060
1061 case PPPIOCGFLAGS:
1062 err = -EFAULT;
1063 if (put_user(ps->flags, (int __user *) arg))
1064 break;
1065
1066 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get flags=%d\n",
1067 session->name, ps->flags);
1068 err = 0;
1069 break;
1070
1071 case PPPIOCSFLAGS:
1072 err = -EFAULT;
1073 if (get_user(val, (int __user *) arg))
1074 break;
1075 ps->flags = val;
1076 l2tp_info(session, L2TP_MSG_CONTROL, "%s: set flags=%d\n",
1077 session->name, ps->flags);
1078 err = 0;
1079 break;
1080
1081 case PPPIOCGL2TPSTATS:
1082 err = -ENXIO;
1083 if (!(sk->sk_state & PPPOX_CONNECTED))
1084 break;
1085
1086 memset(&stats, 0, sizeof(stats));
1087 stats.tunnel_id = tunnel->tunnel_id;
1088 stats.session_id = session->session_id;
1089 pppol2tp_copy_stats(&stats, &session->stats);
1090 if (copy_to_user((void __user *) arg, &stats,
1091 sizeof(stats)))
1092 break;
1093 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get L2TP stats\n",
1094 session->name);
1095 err = 0;
1096 break;
1097
1098 default:
1099 err = -ENOSYS;
1100 break;
1101 }
1102
1103 sock_put(sk);
1104
1105 return err;
1106 }
1107
1108 /* Tunnel ioctl helper.
1109 *
1110 * Note the special handling for PPPIOCGL2TPSTATS below. If the ioctl data
1111 * specifies a session_id, the session ioctl handler is called. This allows an
1112 * application to retrieve session stats via a tunnel socket.
1113 */
1114 static int pppol2tp_tunnel_ioctl(struct l2tp_tunnel *tunnel,
1115 unsigned int cmd, unsigned long arg)
1116 {
1117 int err = 0;
1118 struct sock *sk;
1119 struct pppol2tp_ioc_stats stats;
1120
1121 l2tp_dbg(tunnel, L2TP_MSG_CONTROL,
1122 "%s: pppol2tp_tunnel_ioctl(cmd=%#x, arg=%#lx)\n",
1123 tunnel->name, cmd, arg);
1124
1125 sk = tunnel->sock;
1126 sock_hold(sk);
1127
1128 switch (cmd) {
1129 case PPPIOCGL2TPSTATS:
1130 err = -ENXIO;
1131 if (!(sk->sk_state & PPPOX_CONNECTED))
1132 break;
1133
1134 if (copy_from_user(&stats, (void __user *) arg,
1135 sizeof(stats))) {
1136 err = -EFAULT;
1137 break;
1138 }
1139 if (stats.session_id != 0) {
1140 /* resend to session ioctl handler */
1141 struct l2tp_session *session =
1142 l2tp_session_get(sock_net(sk), tunnel,
1143 stats.session_id, true);
1144
1145 if (session) {
1146 err = pppol2tp_session_ioctl(session, cmd,
1147 arg);
1148 if (session->deref)
1149 session->deref(session);
1150 l2tp_session_dec_refcount(session);
1151 } else {
1152 err = -EBADR;
1153 }
1154 break;
1155 }
1156 #ifdef CONFIG_XFRM
1157 stats.using_ipsec = (sk->sk_policy[0] || sk->sk_policy[1]) ? 1 : 0;
1158 #endif
1159 pppol2tp_copy_stats(&stats, &tunnel->stats);
1160 if (copy_to_user((void __user *) arg, &stats, sizeof(stats))) {
1161 err = -EFAULT;
1162 break;
1163 }
1164 l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: get L2TP stats\n",
1165 tunnel->name);
1166 err = 0;
1167 break;
1168
1169 default:
1170 err = -ENOSYS;
1171 break;
1172 }
1173
1174 sock_put(sk);
1175
1176 return err;
1177 }
1178
1179 /* Main ioctl() handler.
1180 * Dispatch to tunnel or session helpers depending on the socket.
1181 */
1182 static int pppol2tp_ioctl(struct socket *sock, unsigned int cmd,
1183 unsigned long arg)
1184 {
1185 struct sock *sk = sock->sk;
1186 struct l2tp_session *session;
1187 struct l2tp_tunnel *tunnel;
1188 struct pppol2tp_session *ps;
1189 int err;
1190
1191 if (!sk)
1192 return 0;
1193
1194 err = -EBADF;
1195 if (sock_flag(sk, SOCK_DEAD) != 0)
1196 goto end;
1197
1198 err = -ENOTCONN;
1199 if ((sk->sk_user_data == NULL) ||
1200 (!(sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND))))
1201 goto end;
1202
1203 /* Get session context from the socket */
1204 err = -EBADF;
1205 session = pppol2tp_sock_to_session(sk);
1206 if (session == NULL)
1207 goto end;
1208
1209 /* Special case: if session's session_id is zero, treat ioctl as a
1210 * tunnel ioctl
1211 */
1212 ps = l2tp_session_priv(session);
1213 if ((session->session_id == 0) &&
1214 (session->peer_session_id == 0)) {
1215 err = -EBADF;
1216 tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock);
1217 if (tunnel == NULL)
1218 goto end_put_sess;
1219
1220 err = pppol2tp_tunnel_ioctl(tunnel, cmd, arg);
1221 sock_put(ps->tunnel_sock);
1222 goto end_put_sess;
1223 }
1224
1225 err = pppol2tp_session_ioctl(session, cmd, arg);
1226
1227 end_put_sess:
1228 sock_put(sk);
1229 end:
1230 return err;
1231 }
1232
1233 /*****************************************************************************
1234 * setsockopt() / getsockopt() support.
1235 *
1236 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
1237 * sockets. In order to control kernel tunnel features, we allow userspace to
1238 * create a special "tunnel" PPPoX socket which is used for control only.
1239 * Tunnel PPPoX sockets have session_id == 0 and simply allow the user
1240 * application to issue L2TP setsockopt(), getsockopt() and ioctl() calls.
1241 *****************************************************************************/
1242
1243 /* Tunnel setsockopt() helper.
1244 */
1245 static int pppol2tp_tunnel_setsockopt(struct sock *sk,
1246 struct l2tp_tunnel *tunnel,
1247 int optname, int val)
1248 {
1249 int err = 0;
1250
1251 switch (optname) {
1252 case PPPOL2TP_SO_DEBUG:
1253 tunnel->debug = val;
1254 l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: set debug=%x\n",
1255 tunnel->name, tunnel->debug);
1256 break;
1257
1258 default:
1259 err = -ENOPROTOOPT;
1260 break;
1261 }
1262
1263 return err;
1264 }
1265
1266 /* Session setsockopt helper.
1267 */
1268 static int pppol2tp_session_setsockopt(struct sock *sk,
1269 struct l2tp_session *session,
1270 int optname, int val)
1271 {
1272 int err = 0;
1273 struct pppol2tp_session *ps = l2tp_session_priv(session);
1274
1275 switch (optname) {
1276 case PPPOL2TP_SO_RECVSEQ:
1277 if ((val != 0) && (val != 1)) {
1278 err = -EINVAL;
1279 break;
1280 }
1281 session->recv_seq = !!val;
1282 l2tp_info(session, L2TP_MSG_CONTROL,
1283 "%s: set recv_seq=%d\n",
1284 session->name, session->recv_seq);
1285 break;
1286
1287 case PPPOL2TP_SO_SENDSEQ:
1288 if ((val != 0) && (val != 1)) {
1289 err = -EINVAL;
1290 break;
1291 }
1292 session->send_seq = !!val;
1293 {
1294 struct sock *ssk = ps->sock;
1295 struct pppox_sock *po = pppox_sk(ssk);
1296 po->chan.hdrlen = val ? PPPOL2TP_L2TP_HDR_SIZE_SEQ :
1297 PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
1298 }
1299 l2tp_session_set_header_len(session, session->tunnel->version);
1300 l2tp_info(session, L2TP_MSG_CONTROL,
1301 "%s: set send_seq=%d\n",
1302 session->name, session->send_seq);
1303 break;
1304
1305 case PPPOL2TP_SO_LNSMODE:
1306 if ((val != 0) && (val != 1)) {
1307 err = -EINVAL;
1308 break;
1309 }
1310 session->lns_mode = !!val;
1311 l2tp_info(session, L2TP_MSG_CONTROL,
1312 "%s: set lns_mode=%d\n",
1313 session->name, session->lns_mode);
1314 break;
1315
1316 case PPPOL2TP_SO_DEBUG:
1317 session->debug = val;
1318 l2tp_info(session, L2TP_MSG_CONTROL, "%s: set debug=%x\n",
1319 session->name, session->debug);
1320 break;
1321
1322 case PPPOL2TP_SO_REORDERTO:
1323 session->reorder_timeout = msecs_to_jiffies(val);
1324 l2tp_info(session, L2TP_MSG_CONTROL,
1325 "%s: set reorder_timeout=%d\n",
1326 session->name, session->reorder_timeout);
1327 break;
1328
1329 default:
1330 err = -ENOPROTOOPT;
1331 break;
1332 }
1333
1334 return err;
1335 }
1336
1337 /* Main setsockopt() entry point.
1338 * Does API checks, then calls either the tunnel or session setsockopt
1339 * handler, according to whether the PPPoL2TP socket is a for a regular
1340 * session or the special tunnel type.
1341 */
1342 static int pppol2tp_setsockopt(struct socket *sock, int level, int optname,
1343 char __user *optval, unsigned int optlen)
1344 {
1345 struct sock *sk = sock->sk;
1346 struct l2tp_session *session;
1347 struct l2tp_tunnel *tunnel;
1348 struct pppol2tp_session *ps;
1349 int val;
1350 int err;
1351
1352 if (level != SOL_PPPOL2TP)
1353 return -EINVAL;
1354
1355 if (optlen < sizeof(int))
1356 return -EINVAL;
1357
1358 if (get_user(val, (int __user *)optval))
1359 return -EFAULT;
1360
1361 err = -ENOTCONN;
1362 if (sk->sk_user_data == NULL)
1363 goto end;
1364
1365 /* Get session context from the socket */
1366 err = -EBADF;
1367 session = pppol2tp_sock_to_session(sk);
1368 if (session == NULL)
1369 goto end;
1370
1371 /* Special case: if session_id == 0x0000, treat as operation on tunnel
1372 */
1373 ps = l2tp_session_priv(session);
1374 if ((session->session_id == 0) &&
1375 (session->peer_session_id == 0)) {
1376 err = -EBADF;
1377 tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock);
1378 if (tunnel == NULL)
1379 goto end_put_sess;
1380
1381 err = pppol2tp_tunnel_setsockopt(sk, tunnel, optname, val);
1382 sock_put(ps->tunnel_sock);
1383 } else
1384 err = pppol2tp_session_setsockopt(sk, session, optname, val);
1385
1386 err = 0;
1387
1388 end_put_sess:
1389 sock_put(sk);
1390 end:
1391 return err;
1392 }
1393
1394 /* Tunnel getsockopt helper. Called with sock locked.
1395 */
1396 static int pppol2tp_tunnel_getsockopt(struct sock *sk,
1397 struct l2tp_tunnel *tunnel,
1398 int optname, int *val)
1399 {
1400 int err = 0;
1401
1402 switch (optname) {
1403 case PPPOL2TP_SO_DEBUG:
1404 *val = tunnel->debug;
1405 l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: get debug=%x\n",
1406 tunnel->name, tunnel->debug);
1407 break;
1408
1409 default:
1410 err = -ENOPROTOOPT;
1411 break;
1412 }
1413
1414 return err;
1415 }
1416
1417 /* Session getsockopt helper. Called with sock locked.
1418 */
1419 static int pppol2tp_session_getsockopt(struct sock *sk,
1420 struct l2tp_session *session,
1421 int optname, int *val)
1422 {
1423 int err = 0;
1424
1425 switch (optname) {
1426 case PPPOL2TP_SO_RECVSEQ:
1427 *val = session->recv_seq;
1428 l2tp_info(session, L2TP_MSG_CONTROL,
1429 "%s: get recv_seq=%d\n", session->name, *val);
1430 break;
1431
1432 case PPPOL2TP_SO_SENDSEQ:
1433 *val = session->send_seq;
1434 l2tp_info(session, L2TP_MSG_CONTROL,
1435 "%s: get send_seq=%d\n", session->name, *val);
1436 break;
1437
1438 case PPPOL2TP_SO_LNSMODE:
1439 *val = session->lns_mode;
1440 l2tp_info(session, L2TP_MSG_CONTROL,
1441 "%s: get lns_mode=%d\n", session->name, *val);
1442 break;
1443
1444 case PPPOL2TP_SO_DEBUG:
1445 *val = session->debug;
1446 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get debug=%d\n",
1447 session->name, *val);
1448 break;
1449
1450 case PPPOL2TP_SO_REORDERTO:
1451 *val = (int) jiffies_to_msecs(session->reorder_timeout);
1452 l2tp_info(session, L2TP_MSG_CONTROL,
1453 "%s: get reorder_timeout=%d\n", session->name, *val);
1454 break;
1455
1456 default:
1457 err = -ENOPROTOOPT;
1458 }
1459
1460 return err;
1461 }
1462
1463 /* Main getsockopt() entry point.
1464 * Does API checks, then calls either the tunnel or session getsockopt
1465 * handler, according to whether the PPPoX socket is a for a regular session
1466 * or the special tunnel type.
1467 */
1468 static int pppol2tp_getsockopt(struct socket *sock, int level, int optname,
1469 char __user *optval, int __user *optlen)
1470 {
1471 struct sock *sk = sock->sk;
1472 struct l2tp_session *session;
1473 struct l2tp_tunnel *tunnel;
1474 int val, len;
1475 int err;
1476 struct pppol2tp_session *ps;
1477
1478 if (level != SOL_PPPOL2TP)
1479 return -EINVAL;
1480
1481 if (get_user(len, optlen))
1482 return -EFAULT;
1483
1484 len = min_t(unsigned int, len, sizeof(int));
1485
1486 if (len < 0)
1487 return -EINVAL;
1488
1489 err = -ENOTCONN;
1490 if (sk->sk_user_data == NULL)
1491 goto end;
1492
1493 /* Get the session context */
1494 err = -EBADF;
1495 session = pppol2tp_sock_to_session(sk);
1496 if (session == NULL)
1497 goto end;
1498
1499 /* Special case: if session_id == 0x0000, treat as operation on tunnel */
1500 ps = l2tp_session_priv(session);
1501 if ((session->session_id == 0) &&
1502 (session->peer_session_id == 0)) {
1503 err = -EBADF;
1504 tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock);
1505 if (tunnel == NULL)
1506 goto end_put_sess;
1507
1508 err = pppol2tp_tunnel_getsockopt(sk, tunnel, optname, &val);
1509 sock_put(ps->tunnel_sock);
1510 } else
1511 err = pppol2tp_session_getsockopt(sk, session, optname, &val);
1512
1513 err = -EFAULT;
1514 if (put_user(len, optlen))
1515 goto end_put_sess;
1516
1517 if (copy_to_user((void __user *) optval, &val, len))
1518 goto end_put_sess;
1519
1520 err = 0;
1521
1522 end_put_sess:
1523 sock_put(sk);
1524 end:
1525 return err;
1526 }
1527
1528 /*****************************************************************************
1529 * /proc filesystem for debug
1530 * Since the original pppol2tp driver provided /proc/net/pppol2tp for
1531 * L2TPv2, we dump only L2TPv2 tunnels and sessions here.
1532 *****************************************************************************/
1533
1534 static unsigned int pppol2tp_net_id;
1535
1536 #ifdef CONFIG_PROC_FS
1537
1538 struct pppol2tp_seq_data {
1539 struct seq_net_private p;
1540 int tunnel_idx; /* current tunnel */
1541 int session_idx; /* index of session within current tunnel */
1542 struct l2tp_tunnel *tunnel;
1543 struct l2tp_session *session; /* NULL means get next tunnel */
1544 };
1545
1546 static void pppol2tp_next_tunnel(struct net *net, struct pppol2tp_seq_data *pd)
1547 {
1548 for (;;) {
1549 pd->tunnel = l2tp_tunnel_find_nth(net, pd->tunnel_idx);
1550 pd->tunnel_idx++;
1551
1552 if (pd->tunnel == NULL)
1553 break;
1554
1555 /* Ignore L2TPv3 tunnels */
1556 if (pd->tunnel->version < 3)
1557 break;
1558 }
1559 }
1560
1561 static void pppol2tp_next_session(struct net *net, struct pppol2tp_seq_data *pd)
1562 {
1563 pd->session = l2tp_session_get_nth(pd->tunnel, pd->session_idx, true);
1564 pd->session_idx++;
1565
1566 if (pd->session == NULL) {
1567 pd->session_idx = 0;
1568 pppol2tp_next_tunnel(net, pd);
1569 }
1570 }
1571
1572 static void *pppol2tp_seq_start(struct seq_file *m, loff_t *offs)
1573 {
1574 struct pppol2tp_seq_data *pd = SEQ_START_TOKEN;
1575 loff_t pos = *offs;
1576 struct net *net;
1577
1578 if (!pos)
1579 goto out;
1580
1581 BUG_ON(m->private == NULL);
1582 pd = m->private;
1583 net = seq_file_net(m);
1584
1585 if (pd->tunnel == NULL)
1586 pppol2tp_next_tunnel(net, pd);
1587 else
1588 pppol2tp_next_session(net, pd);
1589
1590 /* NULL tunnel and session indicates end of list */
1591 if ((pd->tunnel == NULL) && (pd->session == NULL))
1592 pd = NULL;
1593
1594 out:
1595 return pd;
1596 }
1597
1598 static void *pppol2tp_seq_next(struct seq_file *m, void *v, loff_t *pos)
1599 {
1600 (*pos)++;
1601 return NULL;
1602 }
1603
1604 static void pppol2tp_seq_stop(struct seq_file *p, void *v)
1605 {
1606 /* nothing to do */
1607 }
1608
1609 static void pppol2tp_seq_tunnel_show(struct seq_file *m, void *v)
1610 {
1611 struct l2tp_tunnel *tunnel = v;
1612
1613 seq_printf(m, "\nTUNNEL '%s', %c %d\n",
1614 tunnel->name,
1615 (tunnel == tunnel->sock->sk_user_data) ? 'Y' : 'N',
1616 atomic_read(&tunnel->ref_count) - 1);
1617 seq_printf(m, " %08x %ld/%ld/%ld %ld/%ld/%ld\n",
1618 tunnel->debug,
1619 atomic_long_read(&tunnel->stats.tx_packets),
1620 atomic_long_read(&tunnel->stats.tx_bytes),
1621 atomic_long_read(&tunnel->stats.tx_errors),
1622 atomic_long_read(&tunnel->stats.rx_packets),
1623 atomic_long_read(&tunnel->stats.rx_bytes),
1624 atomic_long_read(&tunnel->stats.rx_errors));
1625 }
1626
1627 static void pppol2tp_seq_session_show(struct seq_file *m, void *v)
1628 {
1629 struct l2tp_session *session = v;
1630 struct l2tp_tunnel *tunnel = session->tunnel;
1631 struct pppol2tp_session *ps = l2tp_session_priv(session);
1632 struct pppox_sock *po = pppox_sk(ps->sock);
1633 u32 ip = 0;
1634 u16 port = 0;
1635
1636 if (tunnel->sock) {
1637 struct inet_sock *inet = inet_sk(tunnel->sock);
1638 ip = ntohl(inet->inet_saddr);
1639 port = ntohs(inet->inet_sport);
1640 }
1641
1642 seq_printf(m, " SESSION '%s' %08X/%d %04X/%04X -> "
1643 "%04X/%04X %d %c\n",
1644 session->name, ip, port,
1645 tunnel->tunnel_id,
1646 session->session_id,
1647 tunnel->peer_tunnel_id,
1648 session->peer_session_id,
1649 ps->sock->sk_state,
1650 (session == ps->sock->sk_user_data) ?
1651 'Y' : 'N');
1652 seq_printf(m, " %d/%d/%c/%c/%s %08x %u\n",
1653 session->mtu, session->mru,
1654 session->recv_seq ? 'R' : '-',
1655 session->send_seq ? 'S' : '-',
1656 session->lns_mode ? "LNS" : "LAC",
1657 session->debug,
1658 jiffies_to_msecs(session->reorder_timeout));
1659 seq_printf(m, " %hu/%hu %ld/%ld/%ld %ld/%ld/%ld\n",
1660 session->nr, session->ns,
1661 atomic_long_read(&session->stats.tx_packets),
1662 atomic_long_read(&session->stats.tx_bytes),
1663 atomic_long_read(&session->stats.tx_errors),
1664 atomic_long_read(&session->stats.rx_packets),
1665 atomic_long_read(&session->stats.rx_bytes),
1666 atomic_long_read(&session->stats.rx_errors));
1667
1668 if (po)
1669 seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan));
1670 }
1671
1672 static int pppol2tp_seq_show(struct seq_file *m, void *v)
1673 {
1674 struct pppol2tp_seq_data *pd = v;
1675
1676 /* display header on line 1 */
1677 if (v == SEQ_START_TOKEN) {
1678 seq_puts(m, "PPPoL2TP driver info, " PPPOL2TP_DRV_VERSION "\n");
1679 seq_puts(m, "TUNNEL name, user-data-ok session-count\n");
1680 seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
1681 seq_puts(m, " SESSION name, addr/port src-tid/sid "
1682 "dest-tid/sid state user-data-ok\n");
1683 seq_puts(m, " mtu/mru/rcvseq/sendseq/lns debug reorderto\n");
1684 seq_puts(m, " nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
1685 goto out;
1686 }
1687
1688 /* Show the tunnel or session context.
1689 */
1690 if (!pd->session) {
1691 pppol2tp_seq_tunnel_show(m, pd->tunnel);
1692 } else {
1693 pppol2tp_seq_session_show(m, pd->session);
1694 if (pd->session->deref)
1695 pd->session->deref(pd->session);
1696 l2tp_session_dec_refcount(pd->session);
1697 }
1698
1699 out:
1700 return 0;
1701 }
1702
1703 static const struct seq_operations pppol2tp_seq_ops = {
1704 .start = pppol2tp_seq_start,
1705 .next = pppol2tp_seq_next,
1706 .stop = pppol2tp_seq_stop,
1707 .show = pppol2tp_seq_show,
1708 };
1709
1710 /* Called when our /proc file is opened. We allocate data for use when
1711 * iterating our tunnel / session contexts and store it in the private
1712 * data of the seq_file.
1713 */
1714 static int pppol2tp_proc_open(struct inode *inode, struct file *file)
1715 {
1716 return seq_open_net(inode, file, &pppol2tp_seq_ops,
1717 sizeof(struct pppol2tp_seq_data));
1718 }
1719
1720 static const struct file_operations pppol2tp_proc_fops = {
1721 .owner = THIS_MODULE,
1722 .open = pppol2tp_proc_open,
1723 .read = seq_read,
1724 .llseek = seq_lseek,
1725 .release = seq_release_net,
1726 };
1727
1728 #endif /* CONFIG_PROC_FS */
1729
1730 /*****************************************************************************
1731 * Network namespace
1732 *****************************************************************************/
1733
1734 static __net_init int pppol2tp_init_net(struct net *net)
1735 {
1736 struct proc_dir_entry *pde;
1737 int err = 0;
1738
1739 pde = proc_create("pppol2tp", S_IRUGO, net->proc_net,
1740 &pppol2tp_proc_fops);
1741 if (!pde) {
1742 err = -ENOMEM;
1743 goto out;
1744 }
1745
1746 out:
1747 return err;
1748 }
1749
1750 static __net_exit void pppol2tp_exit_net(struct net *net)
1751 {
1752 remove_proc_entry("pppol2tp", net->proc_net);
1753 }
1754
1755 static struct pernet_operations pppol2tp_net_ops = {
1756 .init = pppol2tp_init_net,
1757 .exit = pppol2tp_exit_net,
1758 .id = &pppol2tp_net_id,
1759 };
1760
1761 /*****************************************************************************
1762 * Init and cleanup
1763 *****************************************************************************/
1764
1765 static const struct proto_ops pppol2tp_ops = {
1766 .family = AF_PPPOX,
1767 .owner = THIS_MODULE,
1768 .release = pppol2tp_release,
1769 .bind = sock_no_bind,
1770 .connect = pppol2tp_connect,
1771 .socketpair = sock_no_socketpair,
1772 .accept = sock_no_accept,
1773 .getname = pppol2tp_getname,
1774 .poll = datagram_poll,
1775 .listen = sock_no_listen,
1776 .shutdown = sock_no_shutdown,
1777 .setsockopt = pppol2tp_setsockopt,
1778 .getsockopt = pppol2tp_getsockopt,
1779 .sendmsg = pppol2tp_sendmsg,
1780 .recvmsg = pppol2tp_recvmsg,
1781 .mmap = sock_no_mmap,
1782 .ioctl = pppox_ioctl,
1783 };
1784
1785 static const struct pppox_proto pppol2tp_proto = {
1786 .create = pppol2tp_create,
1787 .ioctl = pppol2tp_ioctl,
1788 .owner = THIS_MODULE,
1789 };
1790
1791 #ifdef CONFIG_L2TP_V3
1792
1793 static const struct l2tp_nl_cmd_ops pppol2tp_nl_cmd_ops = {
1794 .session_create = pppol2tp_session_create,
1795 .session_delete = l2tp_session_delete,
1796 };
1797
1798 #endif /* CONFIG_L2TP_V3 */
1799
1800 static int __init pppol2tp_init(void)
1801 {
1802 int err;
1803
1804 err = register_pernet_device(&pppol2tp_net_ops);
1805 if (err)
1806 goto out;
1807
1808 err = proto_register(&pppol2tp_sk_proto, 0);
1809 if (err)
1810 goto out_unregister_pppol2tp_pernet;
1811
1812 err = register_pppox_proto(PX_PROTO_OL2TP, &pppol2tp_proto);
1813 if (err)
1814 goto out_unregister_pppol2tp_proto;
1815
1816 #ifdef CONFIG_L2TP_V3
1817 err = l2tp_nl_register_ops(L2TP_PWTYPE_PPP, &pppol2tp_nl_cmd_ops);
1818 if (err)
1819 goto out_unregister_pppox;
1820 #endif
1821
1822 pr_info("PPPoL2TP kernel driver, %s\n", PPPOL2TP_DRV_VERSION);
1823
1824 out:
1825 return err;
1826
1827 #ifdef CONFIG_L2TP_V3
1828 out_unregister_pppox:
1829 unregister_pppox_proto(PX_PROTO_OL2TP);
1830 #endif
1831 out_unregister_pppol2tp_proto:
1832 proto_unregister(&pppol2tp_sk_proto);
1833 out_unregister_pppol2tp_pernet:
1834 unregister_pernet_device(&pppol2tp_net_ops);
1835 goto out;
1836 }
1837
1838 static void __exit pppol2tp_exit(void)
1839 {
1840 #ifdef CONFIG_L2TP_V3
1841 l2tp_nl_unregister_ops(L2TP_PWTYPE_PPP);
1842 #endif
1843 unregister_pppox_proto(PX_PROTO_OL2TP);
1844 proto_unregister(&pppol2tp_sk_proto);
1845 unregister_pernet_device(&pppol2tp_net_ops);
1846 }
1847
1848 module_init(pppol2tp_init);
1849 module_exit(pppol2tp_exit);
1850
1851 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
1852 MODULE_DESCRIPTION("PPP over L2TP over UDP");
1853 MODULE_LICENSE("GPL");
1854 MODULE_VERSION(PPPOL2TP_DRV_VERSION);
1855 MODULE_ALIAS_NET_PF_PROTO(PF_PPPOX, PX_PROTO_OL2TP);
1856 MODULE_ALIAS_L2TP_PWTYPE(11);
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