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Linux 4.13.16
[linux/fpc-iii.git] / net / l2tp / l2tp_ppp.c
blob412c513d69b3c84838de2394e4f059dec1953558
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 bool drop_tunnel = false;
588 int ver = 2;
589 int fd;
590
591 lock_sock(sk);
592
593 error = -EINVAL;
594 if (sp->sa_protocol != PX_PROTO_OL2TP)
595 goto end;
596
597 /* Check for already bound sockets */
598 error = -EBUSY;
599 if (sk->sk_state & PPPOX_CONNECTED)
600 goto end;
601
602 /* We don't supporting rebinding anyway */
603 error = -EALREADY;
604 if (sk->sk_user_data)
605 goto end; /* socket is already attached */
606
607 /* Get params from socket address. Handle L2TPv2 and L2TPv3.
608 * This is nasty because there are different sockaddr_pppol2tp
609 * structs for L2TPv2, L2TPv3, over IPv4 and IPv6. We use
610 * the sockaddr size to determine which structure the caller
611 * is using.
612 */
613 peer_tunnel_id = 0;
614 if (sockaddr_len == sizeof(struct sockaddr_pppol2tp)) {
615 fd = sp->pppol2tp.fd;
616 tunnel_id = sp->pppol2tp.s_tunnel;
617 peer_tunnel_id = sp->pppol2tp.d_tunnel;
618 session_id = sp->pppol2tp.s_session;
619 peer_session_id = sp->pppol2tp.d_session;
620 } else if (sockaddr_len == sizeof(struct sockaddr_pppol2tpv3)) {
621 struct sockaddr_pppol2tpv3 *sp3 =
622 (struct sockaddr_pppol2tpv3 *) sp;
623 ver = 3;
624 fd = sp3->pppol2tp.fd;
625 tunnel_id = sp3->pppol2tp.s_tunnel;
626 peer_tunnel_id = sp3->pppol2tp.d_tunnel;
627 session_id = sp3->pppol2tp.s_session;
628 peer_session_id = sp3->pppol2tp.d_session;
629 } else if (sockaddr_len == sizeof(struct sockaddr_pppol2tpin6)) {
630 struct sockaddr_pppol2tpin6 *sp6 =
631 (struct sockaddr_pppol2tpin6 *) sp;
632 fd = sp6->pppol2tp.fd;
633 tunnel_id = sp6->pppol2tp.s_tunnel;
634 peer_tunnel_id = sp6->pppol2tp.d_tunnel;
635 session_id = sp6->pppol2tp.s_session;
636 peer_session_id = sp6->pppol2tp.d_session;
637 } else if (sockaddr_len == sizeof(struct sockaddr_pppol2tpv3in6)) {
638 struct sockaddr_pppol2tpv3in6 *sp6 =
639 (struct sockaddr_pppol2tpv3in6 *) sp;
640 ver = 3;
641 fd = sp6->pppol2tp.fd;
642 tunnel_id = sp6->pppol2tp.s_tunnel;
643 peer_tunnel_id = sp6->pppol2tp.d_tunnel;
644 session_id = sp6->pppol2tp.s_session;
645 peer_session_id = sp6->pppol2tp.d_session;
646 } else {
647 error = -EINVAL;
648 goto end; /* bad socket address */
649 }
650
651 /* Don't bind if tunnel_id is 0 */
652 error = -EINVAL;
653 if (tunnel_id == 0)
654 goto end;
655
656 tunnel = l2tp_tunnel_get(sock_net(sk), tunnel_id);
657 if (tunnel)
658 drop_tunnel = true;
659
660 /* Special case: create tunnel context if session_id and
661 * peer_session_id is 0. Otherwise look up tunnel using supplied
662 * tunnel id.
663 */
664 if ((session_id == 0) && (peer_session_id == 0)) {
665 if (tunnel == NULL) {
666 struct l2tp_tunnel_cfg tcfg = {
667 .encap = L2TP_ENCAPTYPE_UDP,
668 .debug = 0,
669 };
670 error = l2tp_tunnel_create(sock_net(sk), fd, ver, tunnel_id, peer_tunnel_id, &tcfg, &tunnel);
671 if (error < 0)
672 goto end;
673 }
674 } else {
675 /* Error if we can't find the tunnel */
676 error = -ENOENT;
677 if (tunnel == NULL)
678 goto end;
679
680 /* Error if socket is not prepped */
681 if (tunnel->sock == NULL)
682 goto end;
683 }
684
685 if (tunnel->recv_payload_hook == NULL)
686 tunnel->recv_payload_hook = pppol2tp_recv_payload_hook;
687
688 if (tunnel->peer_tunnel_id == 0)
689 tunnel->peer_tunnel_id = peer_tunnel_id;
690
691 session = l2tp_session_get(sock_net(sk), tunnel, session_id, false);
692 if (session) {
693 drop_refcnt = true;
694 ps = l2tp_session_priv(session);
695
696 /* Using a pre-existing session is fine as long as it hasn't
697 * been connected yet.
698 */
699 if (ps->sock) {
700 error = -EEXIST;
701 goto end;
702 }
703
704 /* consistency checks */
705 if (ps->tunnel_sock != tunnel->sock) {
706 error = -EEXIST;
707 goto end;
708 }
709 } else {
710 /* Default MTU must allow space for UDP/L2TP/PPP headers */
711 cfg.mtu = 1500 - PPPOL2TP_HEADER_OVERHEAD;
712 cfg.mru = cfg.mtu;
713
714 session = l2tp_session_create(sizeof(struct pppol2tp_session),
715 tunnel, session_id,
716 peer_session_id, &cfg);
717 if (IS_ERR(session)) {
718 error = PTR_ERR(session);
719 goto end;
720 }
721 }
722
723 /* Associate session with its PPPoL2TP socket */
724 ps = l2tp_session_priv(session);
725 ps->owner = current->pid;
726 ps->sock = sk;
727 ps->tunnel_sock = tunnel->sock;
728
729 session->recv_skb = pppol2tp_recv;
730 session->session_close = pppol2tp_session_close;
731 #if IS_ENABLED(CONFIG_L2TP_DEBUGFS)
732 session->show = pppol2tp_show;
733 #endif
734
735 /* We need to know each time a skb is dropped from the reorder
736 * queue.
737 */
738 session->ref = pppol2tp_session_sock_hold;
739 session->deref = pppol2tp_session_sock_put;
740
741 /* If PMTU discovery was enabled, use the MTU that was discovered */
742 dst = sk_dst_get(tunnel->sock);
743 if (dst != NULL) {
744 u32 pmtu = dst_mtu(dst);
745
746 if (pmtu != 0)
747 session->mtu = session->mru = pmtu -
748 PPPOL2TP_HEADER_OVERHEAD;
749 dst_release(dst);
750 }
751
752 /* Special case: if source & dest session_id == 0x0000, this
753 * socket is being created to manage the tunnel. Just set up
754 * the internal context for use by ioctl() and sockopt()
755 * handlers.
756 */
757 if ((session->session_id == 0) &&
758 (session->peer_session_id == 0)) {
759 error = 0;
760 goto out_no_ppp;
761 }
762
763 /* The only header we need to worry about is the L2TP
764 * header. This size is different depending on whether
765 * sequence numbers are enabled for the data channel.
766 */
767 po->chan.hdrlen = PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
768
769 po->chan.private = sk;
770 po->chan.ops = &pppol2tp_chan_ops;
771 po->chan.mtu = session->mtu;
772
773 error = ppp_register_net_channel(sock_net(sk), &po->chan);
774 if (error)
775 goto end;
776
777 out_no_ppp:
778 /* This is how we get the session context from the socket. */
779 sk->sk_user_data = session;
780 sk->sk_state = PPPOX_CONNECTED;
781 l2tp_info(session, L2TP_MSG_CONTROL, "%s: created\n",
782 session->name);
783
784 end:
785 if (drop_refcnt)
786 l2tp_session_dec_refcount(session);
787 if (drop_tunnel)
788 l2tp_tunnel_dec_refcount(tunnel);
789 release_sock(sk);
790
791 return error;
792 }
793
794 #ifdef CONFIG_L2TP_V3
795
796 /* Called when creating sessions via the netlink interface.
797 */
798 static int pppol2tp_session_create(struct net *net, u32 tunnel_id, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg)
799 {
800 int error;
801 struct l2tp_tunnel *tunnel;
802 struct l2tp_session *session;
803 struct pppol2tp_session *ps;
804
805 tunnel = l2tp_tunnel_find(net, tunnel_id);
806
807 /* Error if we can't find the tunnel */
808 error = -ENOENT;
809 if (tunnel == NULL)
810 goto out;
811
812 /* Error if tunnel socket is not prepped */
813 if (tunnel->sock == NULL)
814 goto out;
815
816 /* Default MTU values. */
817 if (cfg->mtu == 0)
818 cfg->mtu = 1500 - PPPOL2TP_HEADER_OVERHEAD;
819 if (cfg->mru == 0)
820 cfg->mru = cfg->mtu;
821
822 /* Allocate and initialize a new session context. */
823 session = l2tp_session_create(sizeof(struct pppol2tp_session),
824 tunnel, session_id,
825 peer_session_id, cfg);
826 if (IS_ERR(session)) {
827 error = PTR_ERR(session);
828 goto out;
829 }
830
831 ps = l2tp_session_priv(session);
832 ps->tunnel_sock = tunnel->sock;
833
834 l2tp_info(session, L2TP_MSG_CONTROL, "%s: created\n",
835 session->name);
836
837 error = 0;
838
839 out:
840 return error;
841 }
842
843 #endif /* CONFIG_L2TP_V3 */
844
845 /* getname() support.
846 */
847 static int pppol2tp_getname(struct socket *sock, struct sockaddr *uaddr,
848 int *usockaddr_len, int peer)
849 {
850 int len = 0;
851 int error = 0;
852 struct l2tp_session *session;
853 struct l2tp_tunnel *tunnel;
854 struct sock *sk = sock->sk;
855 struct inet_sock *inet;
856 struct pppol2tp_session *pls;
857
858 error = -ENOTCONN;
859 if (sk == NULL)
860 goto end;
861 if (!(sk->sk_state & PPPOX_CONNECTED))
862 goto end;
863
864 error = -EBADF;
865 session = pppol2tp_sock_to_session(sk);
866 if (session == NULL)
867 goto end;
868
869 pls = l2tp_session_priv(session);
870 tunnel = l2tp_sock_to_tunnel(pls->tunnel_sock);
871 if (tunnel == NULL)
872 goto end_put_sess;
873
874 inet = inet_sk(tunnel->sock);
875 if ((tunnel->version == 2) && (tunnel->sock->sk_family == AF_INET)) {
876 struct sockaddr_pppol2tp sp;
877 len = sizeof(sp);
878 memset(&sp, 0, len);
879 sp.sa_family = AF_PPPOX;
880 sp.sa_protocol = PX_PROTO_OL2TP;
881 sp.pppol2tp.fd = tunnel->fd;
882 sp.pppol2tp.pid = pls->owner;
883 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
884 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
885 sp.pppol2tp.s_session = session->session_id;
886 sp.pppol2tp.d_session = session->peer_session_id;
887 sp.pppol2tp.addr.sin_family = AF_INET;
888 sp.pppol2tp.addr.sin_port = inet->inet_dport;
889 sp.pppol2tp.addr.sin_addr.s_addr = inet->inet_daddr;
890 memcpy(uaddr, &sp, len);
891 #if IS_ENABLED(CONFIG_IPV6)
892 } else if ((tunnel->version == 2) &&
893 (tunnel->sock->sk_family == AF_INET6)) {
894 struct sockaddr_pppol2tpin6 sp;
895
896 len = sizeof(sp);
897 memset(&sp, 0, len);
898 sp.sa_family = AF_PPPOX;
899 sp.sa_protocol = PX_PROTO_OL2TP;
900 sp.pppol2tp.fd = tunnel->fd;
901 sp.pppol2tp.pid = pls->owner;
902 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
903 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
904 sp.pppol2tp.s_session = session->session_id;
905 sp.pppol2tp.d_session = session->peer_session_id;
906 sp.pppol2tp.addr.sin6_family = AF_INET6;
907 sp.pppol2tp.addr.sin6_port = inet->inet_dport;
908 memcpy(&sp.pppol2tp.addr.sin6_addr, &tunnel->sock->sk_v6_daddr,
909 sizeof(tunnel->sock->sk_v6_daddr));
910 memcpy(uaddr, &sp, len);
911 } else if ((tunnel->version == 3) &&
912 (tunnel->sock->sk_family == AF_INET6)) {
913 struct sockaddr_pppol2tpv3in6 sp;
914
915 len = sizeof(sp);
916 memset(&sp, 0, len);
917 sp.sa_family = AF_PPPOX;
918 sp.sa_protocol = PX_PROTO_OL2TP;
919 sp.pppol2tp.fd = tunnel->fd;
920 sp.pppol2tp.pid = pls->owner;
921 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
922 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
923 sp.pppol2tp.s_session = session->session_id;
924 sp.pppol2tp.d_session = session->peer_session_id;
925 sp.pppol2tp.addr.sin6_family = AF_INET6;
926 sp.pppol2tp.addr.sin6_port = inet->inet_dport;
927 memcpy(&sp.pppol2tp.addr.sin6_addr, &tunnel->sock->sk_v6_daddr,
928 sizeof(tunnel->sock->sk_v6_daddr));
929 memcpy(uaddr, &sp, len);
930 #endif
931 } else if (tunnel->version == 3) {
932 struct sockaddr_pppol2tpv3 sp;
933 len = sizeof(sp);
934 memset(&sp, 0, len);
935 sp.sa_family = AF_PPPOX;
936 sp.sa_protocol = PX_PROTO_OL2TP;
937 sp.pppol2tp.fd = tunnel->fd;
938 sp.pppol2tp.pid = pls->owner;
939 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
940 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
941 sp.pppol2tp.s_session = session->session_id;
942 sp.pppol2tp.d_session = session->peer_session_id;
943 sp.pppol2tp.addr.sin_family = AF_INET;
944 sp.pppol2tp.addr.sin_port = inet->inet_dport;
945 sp.pppol2tp.addr.sin_addr.s_addr = inet->inet_daddr;
946 memcpy(uaddr, &sp, len);
947 }
948
949 *usockaddr_len = len;
950 error = 0;
951
952 sock_put(pls->tunnel_sock);
953 end_put_sess:
954 sock_put(sk);
955 end:
956 return error;
957 }
958
959 /****************************************************************************
960 * ioctl() handlers.
961 *
962 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
963 * sockets. However, in order to control kernel tunnel features, we allow
964 * userspace to create a special "tunnel" PPPoX socket which is used for
965 * control only. Tunnel PPPoX sockets have session_id == 0 and simply allow
966 * the user application to issue L2TP setsockopt(), getsockopt() and ioctl()
967 * calls.
968 ****************************************************************************/
969
970 static void pppol2tp_copy_stats(struct pppol2tp_ioc_stats *dest,
971 struct l2tp_stats *stats)
972 {
973 dest->tx_packets = atomic_long_read(&stats->tx_packets);
974 dest->tx_bytes = atomic_long_read(&stats->tx_bytes);
975 dest->tx_errors = atomic_long_read(&stats->tx_errors);
976 dest->rx_packets = atomic_long_read(&stats->rx_packets);
977 dest->rx_bytes = atomic_long_read(&stats->rx_bytes);
978 dest->rx_seq_discards = atomic_long_read(&stats->rx_seq_discards);
979 dest->rx_oos_packets = atomic_long_read(&stats->rx_oos_packets);
980 dest->rx_errors = atomic_long_read(&stats->rx_errors);
981 }
982
983 /* Session ioctl helper.
984 */
985 static int pppol2tp_session_ioctl(struct l2tp_session *session,
986 unsigned int cmd, unsigned long arg)
987 {
988 struct ifreq ifr;
989 int err = 0;
990 struct sock *sk;
991 int val = (int) arg;
992 struct pppol2tp_session *ps = l2tp_session_priv(session);
993 struct l2tp_tunnel *tunnel = session->tunnel;
994 struct pppol2tp_ioc_stats stats;
995
996 l2tp_dbg(session, L2TP_MSG_CONTROL,
997 "%s: pppol2tp_session_ioctl(cmd=%#x, arg=%#lx)\n",
998 session->name, cmd, arg);
999
1000 sk = ps->sock;
1001 if (!sk)
1002 return -EBADR;
1003
1004 sock_hold(sk);
1005
1006 switch (cmd) {
1007 case SIOCGIFMTU:
1008 err = -ENXIO;
1009 if (!(sk->sk_state & PPPOX_CONNECTED))
1010 break;
1011
1012 err = -EFAULT;
1013 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq)))
1014 break;
1015 ifr.ifr_mtu = session->mtu;
1016 if (copy_to_user((void __user *) arg, &ifr, sizeof(struct ifreq)))
1017 break;
1018
1019 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get mtu=%d\n",
1020 session->name, session->mtu);
1021 err = 0;
1022 break;
1023
1024 case SIOCSIFMTU:
1025 err = -ENXIO;
1026 if (!(sk->sk_state & PPPOX_CONNECTED))
1027 break;
1028
1029 err = -EFAULT;
1030 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq)))
1031 break;
1032
1033 session->mtu = ifr.ifr_mtu;
1034
1035 l2tp_info(session, L2TP_MSG_CONTROL, "%s: set mtu=%d\n",
1036 session->name, session->mtu);
1037 err = 0;
1038 break;
1039
1040 case PPPIOCGMRU:
1041 err = -ENXIO;
1042 if (!(sk->sk_state & PPPOX_CONNECTED))
1043 break;
1044
1045 err = -EFAULT;
1046 if (put_user(session->mru, (int __user *) arg))
1047 break;
1048
1049 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get mru=%d\n",
1050 session->name, session->mru);
1051 err = 0;
1052 break;
1053
1054 case PPPIOCSMRU:
1055 err = -ENXIO;
1056 if (!(sk->sk_state & PPPOX_CONNECTED))
1057 break;
1058
1059 err = -EFAULT;
1060 if (get_user(val, (int __user *) arg))
1061 break;
1062
1063 session->mru = val;
1064 l2tp_info(session, L2TP_MSG_CONTROL, "%s: set mru=%d\n",
1065 session->name, session->mru);
1066 err = 0;
1067 break;
1068
1069 case PPPIOCGFLAGS:
1070 err = -EFAULT;
1071 if (put_user(ps->flags, (int __user *) arg))
1072 break;
1073
1074 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get flags=%d\n",
1075 session->name, ps->flags);
1076 err = 0;
1077 break;
1078
1079 case PPPIOCSFLAGS:
1080 err = -EFAULT;
1081 if (get_user(val, (int __user *) arg))
1082 break;
1083 ps->flags = val;
1084 l2tp_info(session, L2TP_MSG_CONTROL, "%s: set flags=%d\n",
1085 session->name, ps->flags);
1086 err = 0;
1087 break;
1088
1089 case PPPIOCGL2TPSTATS:
1090 err = -ENXIO;
1091 if (!(sk->sk_state & PPPOX_CONNECTED))
1092 break;
1093
1094 memset(&stats, 0, sizeof(stats));
1095 stats.tunnel_id = tunnel->tunnel_id;
1096 stats.session_id = session->session_id;
1097 pppol2tp_copy_stats(&stats, &session->stats);
1098 if (copy_to_user((void __user *) arg, &stats,
1099 sizeof(stats)))
1100 break;
1101 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get L2TP stats\n",
1102 session->name);
1103 err = 0;
1104 break;
1105
1106 default:
1107 err = -ENOSYS;
1108 break;
1109 }
1110
1111 sock_put(sk);
1112
1113 return err;
1114 }
1115
1116 /* Tunnel ioctl helper.
1117 *
1118 * Note the special handling for PPPIOCGL2TPSTATS below. If the ioctl data
1119 * specifies a session_id, the session ioctl handler is called. This allows an
1120 * application to retrieve session stats via a tunnel socket.
1121 */
1122 static int pppol2tp_tunnel_ioctl(struct l2tp_tunnel *tunnel,
1123 unsigned int cmd, unsigned long arg)
1124 {
1125 int err = 0;
1126 struct sock *sk;
1127 struct pppol2tp_ioc_stats stats;
1128
1129 l2tp_dbg(tunnel, L2TP_MSG_CONTROL,
1130 "%s: pppol2tp_tunnel_ioctl(cmd=%#x, arg=%#lx)\n",
1131 tunnel->name, cmd, arg);
1132
1133 sk = tunnel->sock;
1134 sock_hold(sk);
1135
1136 switch (cmd) {
1137 case PPPIOCGL2TPSTATS:
1138 err = -ENXIO;
1139 if (!(sk->sk_state & PPPOX_CONNECTED))
1140 break;
1141
1142 if (copy_from_user(&stats, (void __user *) arg,
1143 sizeof(stats))) {
1144 err = -EFAULT;
1145 break;
1146 }
1147 if (stats.session_id != 0) {
1148 /* resend to session ioctl handler */
1149 struct l2tp_session *session =
1150 l2tp_session_get(sock_net(sk), tunnel,
1151 stats.session_id, true);
1152
1153 if (session) {
1154 err = pppol2tp_session_ioctl(session, cmd,
1155 arg);
1156 if (session->deref)
1157 session->deref(session);
1158 l2tp_session_dec_refcount(session);
1159 } else {
1160 err = -EBADR;
1161 }
1162 break;
1163 }
1164 #ifdef CONFIG_XFRM
1165 stats.using_ipsec = (sk->sk_policy[0] || sk->sk_policy[1]) ? 1 : 0;
1166 #endif
1167 pppol2tp_copy_stats(&stats, &tunnel->stats);
1168 if (copy_to_user((void __user *) arg, &stats, sizeof(stats))) {
1169 err = -EFAULT;
1170 break;
1171 }
1172 l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: get L2TP stats\n",
1173 tunnel->name);
1174 err = 0;
1175 break;
1176
1177 default:
1178 err = -ENOSYS;
1179 break;
1180 }
1181
1182 sock_put(sk);
1183
1184 return err;
1185 }
1186
1187 /* Main ioctl() handler.
1188 * Dispatch to tunnel or session helpers depending on the socket.
1189 */
1190 static int pppol2tp_ioctl(struct socket *sock, unsigned int cmd,
1191 unsigned long arg)
1192 {
1193 struct sock *sk = sock->sk;
1194 struct l2tp_session *session;
1195 struct l2tp_tunnel *tunnel;
1196 struct pppol2tp_session *ps;
1197 int err;
1198
1199 if (!sk)
1200 return 0;
1201
1202 err = -EBADF;
1203 if (sock_flag(sk, SOCK_DEAD) != 0)
1204 goto end;
1205
1206 err = -ENOTCONN;
1207 if ((sk->sk_user_data == NULL) ||
1208 (!(sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND))))
1209 goto end;
1210
1211 /* Get session context from the socket */
1212 err = -EBADF;
1213 session = pppol2tp_sock_to_session(sk);
1214 if (session == NULL)
1215 goto end;
1216
1217 /* Special case: if session's session_id is zero, treat ioctl as a
1218 * tunnel ioctl
1219 */
1220 ps = l2tp_session_priv(session);
1221 if ((session->session_id == 0) &&
1222 (session->peer_session_id == 0)) {
1223 err = -EBADF;
1224 tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock);
1225 if (tunnel == NULL)
1226 goto end_put_sess;
1227
1228 err = pppol2tp_tunnel_ioctl(tunnel, cmd, arg);
1229 sock_put(ps->tunnel_sock);
1230 goto end_put_sess;
1231 }
1232
1233 err = pppol2tp_session_ioctl(session, cmd, arg);
1234
1235 end_put_sess:
1236 sock_put(sk);
1237 end:
1238 return err;
1239 }
1240
1241 /*****************************************************************************
1242 * setsockopt() / getsockopt() support.
1243 *
1244 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
1245 * sockets. In order to control kernel tunnel features, we allow userspace to
1246 * create a special "tunnel" PPPoX socket which is used for control only.
1247 * Tunnel PPPoX sockets have session_id == 0 and simply allow the user
1248 * application to issue L2TP setsockopt(), getsockopt() and ioctl() calls.
1249 *****************************************************************************/
1250
1251 /* Tunnel setsockopt() helper.
1252 */
1253 static int pppol2tp_tunnel_setsockopt(struct sock *sk,
1254 struct l2tp_tunnel *tunnel,
1255 int optname, int val)
1256 {
1257 int err = 0;
1258
1259 switch (optname) {
1260 case PPPOL2TP_SO_DEBUG:
1261 tunnel->debug = val;
1262 l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: set debug=%x\n",
1263 tunnel->name, tunnel->debug);
1264 break;
1265
1266 default:
1267 err = -ENOPROTOOPT;
1268 break;
1269 }
1270
1271 return err;
1272 }
1273
1274 /* Session setsockopt helper.
1275 */
1276 static int pppol2tp_session_setsockopt(struct sock *sk,
1277 struct l2tp_session *session,
1278 int optname, int val)
1279 {
1280 int err = 0;
1281 struct pppol2tp_session *ps = l2tp_session_priv(session);
1282
1283 switch (optname) {
1284 case PPPOL2TP_SO_RECVSEQ:
1285 if ((val != 0) && (val != 1)) {
1286 err = -EINVAL;
1287 break;
1288 }
1289 session->recv_seq = !!val;
1290 l2tp_info(session, L2TP_MSG_CONTROL,
1291 "%s: set recv_seq=%d\n",
1292 session->name, session->recv_seq);
1293 break;
1294
1295 case PPPOL2TP_SO_SENDSEQ:
1296 if ((val != 0) && (val != 1)) {
1297 err = -EINVAL;
1298 break;
1299 }
1300 session->send_seq = !!val;
1301 {
1302 struct sock *ssk = ps->sock;
1303 struct pppox_sock *po = pppox_sk(ssk);
1304 po->chan.hdrlen = val ? PPPOL2TP_L2TP_HDR_SIZE_SEQ :
1305 PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
1306 }
1307 l2tp_session_set_header_len(session, session->tunnel->version);
1308 l2tp_info(session, L2TP_MSG_CONTROL,
1309 "%s: set send_seq=%d\n",
1310 session->name, session->send_seq);
1311 break;
1312
1313 case PPPOL2TP_SO_LNSMODE:
1314 if ((val != 0) && (val != 1)) {
1315 err = -EINVAL;
1316 break;
1317 }
1318 session->lns_mode = !!val;
1319 l2tp_info(session, L2TP_MSG_CONTROL,
1320 "%s: set lns_mode=%d\n",
1321 session->name, session->lns_mode);
1322 break;
1323
1324 case PPPOL2TP_SO_DEBUG:
1325 session->debug = val;
1326 l2tp_info(session, L2TP_MSG_CONTROL, "%s: set debug=%x\n",
1327 session->name, session->debug);
1328 break;
1329
1330 case PPPOL2TP_SO_REORDERTO:
1331 session->reorder_timeout = msecs_to_jiffies(val);
1332 l2tp_info(session, L2TP_MSG_CONTROL,
1333 "%s: set reorder_timeout=%d\n",
1334 session->name, session->reorder_timeout);
1335 break;
1336
1337 default:
1338 err = -ENOPROTOOPT;
1339 break;
1340 }
1341
1342 return err;
1343 }
1344
1345 /* Main setsockopt() entry point.
1346 * Does API checks, then calls either the tunnel or session setsockopt
1347 * handler, according to whether the PPPoL2TP socket is a for a regular
1348 * session or the special tunnel type.
1349 */
1350 static int pppol2tp_setsockopt(struct socket *sock, int level, int optname,
1351 char __user *optval, unsigned int optlen)
1352 {
1353 struct sock *sk = sock->sk;
1354 struct l2tp_session *session;
1355 struct l2tp_tunnel *tunnel;
1356 struct pppol2tp_session *ps;
1357 int val;
1358 int err;
1359
1360 if (level != SOL_PPPOL2TP)
1361 return -EINVAL;
1362
1363 if (optlen < sizeof(int))
1364 return -EINVAL;
1365
1366 if (get_user(val, (int __user *)optval))
1367 return -EFAULT;
1368
1369 err = -ENOTCONN;
1370 if (sk->sk_user_data == NULL)
1371 goto end;
1372
1373 /* Get session context from the socket */
1374 err = -EBADF;
1375 session = pppol2tp_sock_to_session(sk);
1376 if (session == NULL)
1377 goto end;
1378
1379 /* Special case: if session_id == 0x0000, treat as operation on tunnel
1380 */
1381 ps = l2tp_session_priv(session);
1382 if ((session->session_id == 0) &&
1383 (session->peer_session_id == 0)) {
1384 err = -EBADF;
1385 tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock);
1386 if (tunnel == NULL)
1387 goto end_put_sess;
1388
1389 err = pppol2tp_tunnel_setsockopt(sk, tunnel, optname, val);
1390 sock_put(ps->tunnel_sock);
1391 } else
1392 err = pppol2tp_session_setsockopt(sk, session, optname, val);
1393
1394 end_put_sess:
1395 sock_put(sk);
1396 end:
1397 return err;
1398 }
1399
1400 /* Tunnel getsockopt helper. Called with sock locked.
1401 */
1402 static int pppol2tp_tunnel_getsockopt(struct sock *sk,
1403 struct l2tp_tunnel *tunnel,
1404 int optname, int *val)
1405 {
1406 int err = 0;
1407
1408 switch (optname) {
1409 case PPPOL2TP_SO_DEBUG:
1410 *val = tunnel->debug;
1411 l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: get debug=%x\n",
1412 tunnel->name, tunnel->debug);
1413 break;
1414
1415 default:
1416 err = -ENOPROTOOPT;
1417 break;
1418 }
1419
1420 return err;
1421 }
1422
1423 /* Session getsockopt helper. Called with sock locked.
1424 */
1425 static int pppol2tp_session_getsockopt(struct sock *sk,
1426 struct l2tp_session *session,
1427 int optname, int *val)
1428 {
1429 int err = 0;
1430
1431 switch (optname) {
1432 case PPPOL2TP_SO_RECVSEQ:
1433 *val = session->recv_seq;
1434 l2tp_info(session, L2TP_MSG_CONTROL,
1435 "%s: get recv_seq=%d\n", session->name, *val);
1436 break;
1437
1438 case PPPOL2TP_SO_SENDSEQ:
1439 *val = session->send_seq;
1440 l2tp_info(session, L2TP_MSG_CONTROL,
1441 "%s: get send_seq=%d\n", session->name, *val);
1442 break;
1443
1444 case PPPOL2TP_SO_LNSMODE:
1445 *val = session->lns_mode;
1446 l2tp_info(session, L2TP_MSG_CONTROL,
1447 "%s: get lns_mode=%d\n", session->name, *val);
1448 break;
1449
1450 case PPPOL2TP_SO_DEBUG:
1451 *val = session->debug;
1452 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get debug=%d\n",
1453 session->name, *val);
1454 break;
1455
1456 case PPPOL2TP_SO_REORDERTO:
1457 *val = (int) jiffies_to_msecs(session->reorder_timeout);
1458 l2tp_info(session, L2TP_MSG_CONTROL,
1459 "%s: get reorder_timeout=%d\n", session->name, *val);
1460 break;
1461
1462 default:
1463 err = -ENOPROTOOPT;
1464 }
1465
1466 return err;
1467 }
1468
1469 /* Main getsockopt() entry point.
1470 * Does API checks, then calls either the tunnel or session getsockopt
1471 * handler, according to whether the PPPoX socket is a for a regular session
1472 * or the special tunnel type.
1473 */
1474 static int pppol2tp_getsockopt(struct socket *sock, int level, int optname,
1475 char __user *optval, int __user *optlen)
1476 {
1477 struct sock *sk = sock->sk;
1478 struct l2tp_session *session;
1479 struct l2tp_tunnel *tunnel;
1480 int val, len;
1481 int err;
1482 struct pppol2tp_session *ps;
1483
1484 if (level != SOL_PPPOL2TP)
1485 return -EINVAL;
1486
1487 if (get_user(len, optlen))
1488 return -EFAULT;
1489
1490 len = min_t(unsigned int, len, sizeof(int));
1491
1492 if (len < 0)
1493 return -EINVAL;
1494
1495 err = -ENOTCONN;
1496 if (sk->sk_user_data == NULL)
1497 goto end;
1498
1499 /* Get the session context */
1500 err = -EBADF;
1501 session = pppol2tp_sock_to_session(sk);
1502 if (session == NULL)
1503 goto end;
1504
1505 /* Special case: if session_id == 0x0000, treat as operation on tunnel */
1506 ps = l2tp_session_priv(session);
1507 if ((session->session_id == 0) &&
1508 (session->peer_session_id == 0)) {
1509 err = -EBADF;
1510 tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock);
1511 if (tunnel == NULL)
1512 goto end_put_sess;
1513
1514 err = pppol2tp_tunnel_getsockopt(sk, tunnel, optname, &val);
1515 sock_put(ps->tunnel_sock);
1516 if (err)
1517 goto end_put_sess;
1518 } else {
1519 err = pppol2tp_session_getsockopt(sk, session, optname, &val);
1520 if (err)
1521 goto end_put_sess;
1522 }
1523
1524 err = -EFAULT;
1525 if (put_user(len, optlen))
1526 goto end_put_sess;
1527
1528 if (copy_to_user((void __user *) optval, &val, len))
1529 goto end_put_sess;
1530
1531 err = 0;
1532
1533 end_put_sess:
1534 sock_put(sk);
1535 end:
1536 return err;
1537 }
1538
1539 /*****************************************************************************
1540 * /proc filesystem for debug
1541 * Since the original pppol2tp driver provided /proc/net/pppol2tp for
1542 * L2TPv2, we dump only L2TPv2 tunnels and sessions here.
1543 *****************************************************************************/
1544
1545 static unsigned int pppol2tp_net_id;
1546
1547 #ifdef CONFIG_PROC_FS
1548
1549 struct pppol2tp_seq_data {
1550 struct seq_net_private p;
1551 int tunnel_idx; /* current tunnel */
1552 int session_idx; /* index of session within current tunnel */
1553 struct l2tp_tunnel *tunnel;
1554 struct l2tp_session *session; /* NULL means get next tunnel */
1555 };
1556
1557 static void pppol2tp_next_tunnel(struct net *net, struct pppol2tp_seq_data *pd)
1558 {
1559 for (;;) {
1560 pd->tunnel = l2tp_tunnel_find_nth(net, pd->tunnel_idx);
1561 pd->tunnel_idx++;
1562
1563 if (pd->tunnel == NULL)
1564 break;
1565
1566 /* Ignore L2TPv3 tunnels */
1567 if (pd->tunnel->version < 3)
1568 break;
1569 }
1570 }
1571
1572 static void pppol2tp_next_session(struct net *net, struct pppol2tp_seq_data *pd)
1573 {
1574 pd->session = l2tp_session_get_nth(pd->tunnel, pd->session_idx, true);
1575 pd->session_idx++;
1576
1577 if (pd->session == NULL) {
1578 pd->session_idx = 0;
1579 pppol2tp_next_tunnel(net, pd);
1580 }
1581 }
1582
1583 static void *pppol2tp_seq_start(struct seq_file *m, loff_t *offs)
1584 {
1585 struct pppol2tp_seq_data *pd = SEQ_START_TOKEN;
1586 loff_t pos = *offs;
1587 struct net *net;
1588
1589 if (!pos)
1590 goto out;
1591
1592 BUG_ON(m->private == NULL);
1593 pd = m->private;
1594 net = seq_file_net(m);
1595
1596 if (pd->tunnel == NULL)
1597 pppol2tp_next_tunnel(net, pd);
1598 else
1599 pppol2tp_next_session(net, pd);
1600
1601 /* NULL tunnel and session indicates end of list */
1602 if ((pd->tunnel == NULL) && (pd->session == NULL))
1603 pd = NULL;
1604
1605 out:
1606 return pd;
1607 }
1608
1609 static void *pppol2tp_seq_next(struct seq_file *m, void *v, loff_t *pos)
1610 {
1611 (*pos)++;
1612 return NULL;
1613 }
1614
1615 static void pppol2tp_seq_stop(struct seq_file *p, void *v)
1616 {
1617 /* nothing to do */
1618 }
1619
1620 static void pppol2tp_seq_tunnel_show(struct seq_file *m, void *v)
1621 {
1622 struct l2tp_tunnel *tunnel = v;
1623
1624 seq_printf(m, "\nTUNNEL '%s', %c %d\n",
1625 tunnel->name,
1626 (tunnel == tunnel->sock->sk_user_data) ? 'Y' : 'N',
1627 refcount_read(&tunnel->ref_count) - 1);
1628 seq_printf(m, " %08x %ld/%ld/%ld %ld/%ld/%ld\n",
1629 tunnel->debug,
1630 atomic_long_read(&tunnel->stats.tx_packets),
1631 atomic_long_read(&tunnel->stats.tx_bytes),
1632 atomic_long_read(&tunnel->stats.tx_errors),
1633 atomic_long_read(&tunnel->stats.rx_packets),
1634 atomic_long_read(&tunnel->stats.rx_bytes),
1635 atomic_long_read(&tunnel->stats.rx_errors));
1636 }
1637
1638 static void pppol2tp_seq_session_show(struct seq_file *m, void *v)
1639 {
1640 struct l2tp_session *session = v;
1641 struct l2tp_tunnel *tunnel = session->tunnel;
1642 struct pppol2tp_session *ps = l2tp_session_priv(session);
1643 struct pppox_sock *po = pppox_sk(ps->sock);
1644 u32 ip = 0;
1645 u16 port = 0;
1646
1647 if (tunnel->sock) {
1648 struct inet_sock *inet = inet_sk(tunnel->sock);
1649 ip = ntohl(inet->inet_saddr);
1650 port = ntohs(inet->inet_sport);
1651 }
1652
1653 seq_printf(m, " SESSION '%s' %08X/%d %04X/%04X -> "
1654 "%04X/%04X %d %c\n",
1655 session->name, ip, port,
1656 tunnel->tunnel_id,
1657 session->session_id,
1658 tunnel->peer_tunnel_id,
1659 session->peer_session_id,
1660 ps->sock->sk_state,
1661 (session == ps->sock->sk_user_data) ?
1662 'Y' : 'N');
1663 seq_printf(m, " %d/%d/%c/%c/%s %08x %u\n",
1664 session->mtu, session->mru,
1665 session->recv_seq ? 'R' : '-',
1666 session->send_seq ? 'S' : '-',
1667 session->lns_mode ? "LNS" : "LAC",
1668 session->debug,
1669 jiffies_to_msecs(session->reorder_timeout));
1670 seq_printf(m, " %hu/%hu %ld/%ld/%ld %ld/%ld/%ld\n",
1671 session->nr, session->ns,
1672 atomic_long_read(&session->stats.tx_packets),
1673 atomic_long_read(&session->stats.tx_bytes),
1674 atomic_long_read(&session->stats.tx_errors),
1675 atomic_long_read(&session->stats.rx_packets),
1676 atomic_long_read(&session->stats.rx_bytes),
1677 atomic_long_read(&session->stats.rx_errors));
1678
1679 if (po)
1680 seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan));
1681 }
1682
1683 static int pppol2tp_seq_show(struct seq_file *m, void *v)
1684 {
1685 struct pppol2tp_seq_data *pd = v;
1686
1687 /* display header on line 1 */
1688 if (v == SEQ_START_TOKEN) {
1689 seq_puts(m, "PPPoL2TP driver info, " PPPOL2TP_DRV_VERSION "\n");
1690 seq_puts(m, "TUNNEL name, user-data-ok session-count\n");
1691 seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
1692 seq_puts(m, " SESSION name, addr/port src-tid/sid "
1693 "dest-tid/sid state user-data-ok\n");
1694 seq_puts(m, " mtu/mru/rcvseq/sendseq/lns debug reorderto\n");
1695 seq_puts(m, " nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
1696 goto out;
1697 }
1698
1699 /* Show the tunnel or session context.
1700 */
1701 if (!pd->session) {
1702 pppol2tp_seq_tunnel_show(m, pd->tunnel);
1703 } else {
1704 pppol2tp_seq_session_show(m, pd->session);
1705 if (pd->session->deref)
1706 pd->session->deref(pd->session);
1707 l2tp_session_dec_refcount(pd->session);
1708 }
1709
1710 out:
1711 return 0;
1712 }
1713
1714 static const struct seq_operations pppol2tp_seq_ops = {
1715 .start = pppol2tp_seq_start,
1716 .next = pppol2tp_seq_next,
1717 .stop = pppol2tp_seq_stop,
1718 .show = pppol2tp_seq_show,
1719 };
1720
1721 /* Called when our /proc file is opened. We allocate data for use when
1722 * iterating our tunnel / session contexts and store it in the private
1723 * data of the seq_file.
1724 */
1725 static int pppol2tp_proc_open(struct inode *inode, struct file *file)
1726 {
1727 return seq_open_net(inode, file, &pppol2tp_seq_ops,
1728 sizeof(struct pppol2tp_seq_data));
1729 }
1730
1731 static const struct file_operations pppol2tp_proc_fops = {
1732 .owner = THIS_MODULE,
1733 .open = pppol2tp_proc_open,
1734 .read = seq_read,
1735 .llseek = seq_lseek,
1736 .release = seq_release_net,
1737 };
1738
1739 #endif /* CONFIG_PROC_FS */
1740
1741 /*****************************************************************************
1742 * Network namespace
1743 *****************************************************************************/
1744
1745 static __net_init int pppol2tp_init_net(struct net *net)
1746 {
1747 struct proc_dir_entry *pde;
1748 int err = 0;
1749
1750 pde = proc_create("pppol2tp", S_IRUGO, net->proc_net,
1751 &pppol2tp_proc_fops);
1752 if (!pde) {
1753 err = -ENOMEM;
1754 goto out;
1755 }
1756
1757 out:
1758 return err;
1759 }
1760
1761 static __net_exit void pppol2tp_exit_net(struct net *net)
1762 {
1763 remove_proc_entry("pppol2tp", net->proc_net);
1764 }
1765
1766 static struct pernet_operations pppol2tp_net_ops = {
1767 .init = pppol2tp_init_net,
1768 .exit = pppol2tp_exit_net,
1769 .id = &pppol2tp_net_id,
1770 };
1771
1772 /*****************************************************************************
1773 * Init and cleanup
1774 *****************************************************************************/
1775
1776 static const struct proto_ops pppol2tp_ops = {
1777 .family = AF_PPPOX,
1778 .owner = THIS_MODULE,
1779 .release = pppol2tp_release,
1780 .bind = sock_no_bind,
1781 .connect = pppol2tp_connect,
1782 .socketpair = sock_no_socketpair,
1783 .accept = sock_no_accept,
1784 .getname = pppol2tp_getname,
1785 .poll = datagram_poll,
1786 .listen = sock_no_listen,
1787 .shutdown = sock_no_shutdown,
1788 .setsockopt = pppol2tp_setsockopt,
1789 .getsockopt = pppol2tp_getsockopt,
1790 .sendmsg = pppol2tp_sendmsg,
1791 .recvmsg = pppol2tp_recvmsg,
1792 .mmap = sock_no_mmap,
1793 .ioctl = pppox_ioctl,
1794 };
1795
1796 static const struct pppox_proto pppol2tp_proto = {
1797 .create = pppol2tp_create,
1798 .ioctl = pppol2tp_ioctl,
1799 .owner = THIS_MODULE,
1800 };
1801
1802 #ifdef CONFIG_L2TP_V3
1803
1804 static const struct l2tp_nl_cmd_ops pppol2tp_nl_cmd_ops = {
1805 .session_create = pppol2tp_session_create,
1806 .session_delete = l2tp_session_delete,
1807 };
1808
1809 #endif /* CONFIG_L2TP_V3 */
1810
1811 static int __init pppol2tp_init(void)
1812 {
1813 int err;
1814
1815 err = register_pernet_device(&pppol2tp_net_ops);
1816 if (err)
1817 goto out;
1818
1819 err = proto_register(&pppol2tp_sk_proto, 0);
1820 if (err)
1821 goto out_unregister_pppol2tp_pernet;
1822
1823 err = register_pppox_proto(PX_PROTO_OL2TP, &pppol2tp_proto);
1824 if (err)
1825 goto out_unregister_pppol2tp_proto;
1826
1827 #ifdef CONFIG_L2TP_V3
1828 err = l2tp_nl_register_ops(L2TP_PWTYPE_PPP, &pppol2tp_nl_cmd_ops);
1829 if (err)
1830 goto out_unregister_pppox;
1831 #endif
1832
1833 pr_info("PPPoL2TP kernel driver, %s\n", PPPOL2TP_DRV_VERSION);
1834
1835 out:
1836 return err;
1837
1838 #ifdef CONFIG_L2TP_V3
1839 out_unregister_pppox:
1840 unregister_pppox_proto(PX_PROTO_OL2TP);
1841 #endif
1842 out_unregister_pppol2tp_proto:
1843 proto_unregister(&pppol2tp_sk_proto);
1844 out_unregister_pppol2tp_pernet:
1845 unregister_pernet_device(&pppol2tp_net_ops);
1846 goto out;
1847 }
1848
1849 static void __exit pppol2tp_exit(void)
1850 {
1851 #ifdef CONFIG_L2TP_V3
1852 l2tp_nl_unregister_ops(L2TP_PWTYPE_PPP);
1853 #endif
1854 unregister_pppox_proto(PX_PROTO_OL2TP);
1855 proto_unregister(&pppol2tp_sk_proto);
1856 unregister_pernet_device(&pppol2tp_net_ops);
1857 }
1858
1859 module_init(pppol2tp_init);
1860 module_exit(pppol2tp_exit);
1861
1862 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
1863 MODULE_DESCRIPTION("PPP over L2TP over UDP");
1864 MODULE_LICENSE("GPL");
1865 MODULE_VERSION(PPPOL2TP_DRV_VERSION);
1866 MODULE_ALIAS_NET_PF_PROTO(PF_PPPOX, PX_PROTO_OL2TP);
1867 MODULE_ALIAS_L2TP_PWTYPE(7);
Linux with added FPC-III support