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Linux 4.8-rc8
[linux/fpc-iii.git] / net / l2tp / l2tp_ppp.c
blob232cb92033e8225f76d72deb5af5ef93c4d6187f
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] == 0xff) && (skb->data[1] == 0x03))
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, PPPOL2TP_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, PPPOL2TP_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, PPPOL2TP_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 static const unsigned char ppph[2] = { 0xff, 0x03 };
286 struct sock *sk = sock->sk;
287 struct sk_buff *skb;
288 int error;
289 struct l2tp_session *session;
290 struct l2tp_tunnel *tunnel;
291 struct pppol2tp_session *ps;
292 int uhlen;
293
294 error = -ENOTCONN;
295 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
296 goto error;
297
298 /* Get session and tunnel contexts */
299 error = -EBADF;
300 session = pppol2tp_sock_to_session(sk);
301 if (session == NULL)
302 goto error;
303
304 ps = l2tp_session_priv(session);
305 tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock);
306 if (tunnel == NULL)
307 goto error_put_sess;
308
309 uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0;
310
311 /* Allocate a socket buffer */
312 error = -ENOMEM;
313 skb = sock_wmalloc(sk, NET_SKB_PAD + sizeof(struct iphdr) +
314 uhlen + session->hdr_len +
315 sizeof(ppph) + total_len,
316 0, GFP_KERNEL);
317 if (!skb)
318 goto error_put_sess_tun;
319
320 /* Reserve space for headers. */
321 skb_reserve(skb, NET_SKB_PAD);
322 skb_reset_network_header(skb);
323 skb_reserve(skb, sizeof(struct iphdr));
324 skb_reset_transport_header(skb);
325 skb_reserve(skb, uhlen);
326
327 /* Add PPP header */
328 skb->data[0] = ppph[0];
329 skb->data[1] = ppph[1];
330 skb_put(skb, 2);
331
332 /* Copy user data into skb */
333 error = memcpy_from_msg(skb_put(skb, total_len), m, total_len);
334 if (error < 0) {
335 kfree_skb(skb);
336 goto error_put_sess_tun;
337 }
338
339 local_bh_disable();
340 l2tp_xmit_skb(session, skb, session->hdr_len);
341 local_bh_enable();
342
343 sock_put(ps->tunnel_sock);
344 sock_put(sk);
345
346 return total_len;
347
348 error_put_sess_tun:
349 sock_put(ps->tunnel_sock);
350 error_put_sess:
351 sock_put(sk);
352 error:
353 return error;
354 }
355
356 /* Transmit function called by generic PPP driver. Sends PPP frame
357 * over PPPoL2TP socket.
358 *
359 * This is almost the same as pppol2tp_sendmsg(), but rather than
360 * being called with a msghdr from userspace, it is called with a skb
361 * from the kernel.
362 *
363 * The supplied skb from ppp doesn't have enough headroom for the
364 * insertion of L2TP, UDP and IP headers so we need to allocate more
365 * headroom in the skb. This will create a cloned skb. But we must be
366 * careful in the error case because the caller will expect to free
367 * the skb it supplied, not our cloned skb. So we take care to always
368 * leave the original skb unfreed if we return an error.
369 */
370 static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
371 {
372 static const u8 ppph[2] = { 0xff, 0x03 };
373 struct sock *sk = (struct sock *) chan->private;
374 struct sock *sk_tun;
375 struct l2tp_session *session;
376 struct l2tp_tunnel *tunnel;
377 struct pppol2tp_session *ps;
378 int uhlen, headroom;
379
380 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
381 goto abort;
382
383 /* Get session and tunnel contexts from the socket */
384 session = pppol2tp_sock_to_session(sk);
385 if (session == NULL)
386 goto abort;
387
388 ps = l2tp_session_priv(session);
389 sk_tun = ps->tunnel_sock;
390 if (sk_tun == NULL)
391 goto abort_put_sess;
392 tunnel = l2tp_sock_to_tunnel(sk_tun);
393 if (tunnel == NULL)
394 goto abort_put_sess;
395
396 uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0;
397 headroom = NET_SKB_PAD +
398 sizeof(struct iphdr) + /* IP header */
399 uhlen + /* UDP header (if L2TP_ENCAPTYPE_UDP) */
400 session->hdr_len + /* L2TP header */
401 sizeof(ppph); /* PPP header */
402 if (skb_cow_head(skb, headroom))
403 goto abort_put_sess_tun;
404
405 /* Setup PPP header */
406 __skb_push(skb, sizeof(ppph));
407 skb->data[0] = ppph[0];
408 skb->data[1] = ppph[1];
409
410 local_bh_disable();
411 l2tp_xmit_skb(session, skb, session->hdr_len);
412 local_bh_enable();
413
414 sock_put(sk_tun);
415 sock_put(sk);
416 return 1;
417
418 abort_put_sess_tun:
419 sock_put(sk_tun);
420 abort_put_sess:
421 sock_put(sk);
422 abort:
423 /* Free the original skb */
424 kfree_skb(skb);
425 return 1;
426 }
427
428 /*****************************************************************************
429 * Session (and tunnel control) socket create/destroy.
430 *****************************************************************************/
431
432 /* Called by l2tp_core when a session socket is being closed.
433 */
434 static void pppol2tp_session_close(struct l2tp_session *session)
435 {
436 struct pppol2tp_session *ps = l2tp_session_priv(session);
437 struct sock *sk = ps->sock;
438 struct socket *sock = sk->sk_socket;
439
440 BUG_ON(session->magic != L2TP_SESSION_MAGIC);
441
442 if (sock) {
443 inet_shutdown(sock, 2);
444 /* Don't let the session go away before our socket does */
445 l2tp_session_inc_refcount(session);
446 }
447 }
448
449 /* Really kill the session socket. (Called from sock_put() if
450 * refcnt == 0.)
451 */
452 static void pppol2tp_session_destruct(struct sock *sk)
453 {
454 struct l2tp_session *session = sk->sk_user_data;
455 if (session) {
456 sk->sk_user_data = NULL;
457 BUG_ON(session->magic != L2TP_SESSION_MAGIC);
458 l2tp_session_dec_refcount(session);
459 }
460 }
461
462 /* Called when the PPPoX socket (session) is closed.
463 */
464 static int pppol2tp_release(struct socket *sock)
465 {
466 struct sock *sk = sock->sk;
467 struct l2tp_session *session;
468 int error;
469
470 if (!sk)
471 return 0;
472
473 error = -EBADF;
474 lock_sock(sk);
475 if (sock_flag(sk, SOCK_DEAD) != 0)
476 goto error;
477
478 pppox_unbind_sock(sk);
479
480 /* Signal the death of the socket. */
481 sk->sk_state = PPPOX_DEAD;
482 sock_orphan(sk);
483 sock->sk = NULL;
484
485 session = pppol2tp_sock_to_session(sk);
486
487 /* Purge any queued data */
488 if (session != NULL) {
489 __l2tp_session_unhash(session);
490 l2tp_session_queue_purge(session);
491 sock_put(sk);
492 }
493 skb_queue_purge(&sk->sk_receive_queue);
494 skb_queue_purge(&sk->sk_write_queue);
495
496 release_sock(sk);
497
498 /* This will delete the session context via
499 * pppol2tp_session_destruct() if the socket's refcnt drops to
500 * zero.
501 */
502 sock_put(sk);
503
504 return 0;
505
506 error:
507 release_sock(sk);
508 return error;
509 }
510
511 static struct proto pppol2tp_sk_proto = {
512 .name = "PPPOL2TP",
513 .owner = THIS_MODULE,
514 .obj_size = sizeof(struct pppox_sock),
515 };
516
517 static int pppol2tp_backlog_recv(struct sock *sk, struct sk_buff *skb)
518 {
519 int rc;
520
521 rc = l2tp_udp_encap_recv(sk, skb);
522 if (rc)
523 kfree_skb(skb);
524
525 return NET_RX_SUCCESS;
526 }
527
528 /* socket() handler. Initialize a new struct sock.
529 */
530 static int pppol2tp_create(struct net *net, struct socket *sock, int kern)
531 {
532 int error = -ENOMEM;
533 struct sock *sk;
534
535 sk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, &pppol2tp_sk_proto, kern);
536 if (!sk)
537 goto out;
538
539 sock_init_data(sock, sk);
540
541 sock->state = SS_UNCONNECTED;
542 sock->ops = &pppol2tp_ops;
543
544 sk->sk_backlog_rcv = pppol2tp_backlog_recv;
545 sk->sk_protocol = PX_PROTO_OL2TP;
546 sk->sk_family = PF_PPPOX;
547 sk->sk_state = PPPOX_NONE;
548 sk->sk_type = SOCK_STREAM;
549 sk->sk_destruct = pppol2tp_session_destruct;
550
551 error = 0;
552
553 out:
554 return error;
555 }
556
557 #if defined(CONFIG_L2TP_DEBUGFS) || defined(CONFIG_L2TP_DEBUGFS_MODULE)
558 static void pppol2tp_show(struct seq_file *m, void *arg)
559 {
560 struct l2tp_session *session = arg;
561 struct pppol2tp_session *ps = l2tp_session_priv(session);
562
563 if (ps) {
564 struct pppox_sock *po = pppox_sk(ps->sock);
565 if (po)
566 seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan));
567 }
568 }
569 #endif
570
571 /* connect() handler. Attach a PPPoX socket to a tunnel UDP socket
572 */
573 static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr,
574 int sockaddr_len, int flags)
575 {
576 struct sock *sk = sock->sk;
577 struct sockaddr_pppol2tp *sp = (struct sockaddr_pppol2tp *) uservaddr;
578 struct pppox_sock *po = pppox_sk(sk);
579 struct l2tp_session *session = NULL;
580 struct l2tp_tunnel *tunnel;
581 struct pppol2tp_session *ps;
582 struct dst_entry *dst;
583 struct l2tp_session_cfg cfg = { 0, };
584 int error = 0;
585 u32 tunnel_id, peer_tunnel_id;
586 u32 session_id, peer_session_id;
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 /* Create session if it doesn't already exist. We handle the
689 * case where a session was previously created by the netlink
690 * interface by checking that the session doesn't already have
691 * a socket and its tunnel socket are what we expect. If any
692 * of those checks fail, return EEXIST to the caller.
693 */
694 session = l2tp_session_find(sock_net(sk), tunnel, session_id);
695 if (session == NULL) {
696 /* Default MTU must allow space for UDP/L2TP/PPP
697 * headers.
698 */
699 cfg.mtu = cfg.mru = 1500 - PPPOL2TP_HEADER_OVERHEAD;
700
701 /* Allocate and initialize a new session context. */
702 session = l2tp_session_create(sizeof(struct pppol2tp_session),
703 tunnel, session_id,
704 peer_session_id, &cfg);
705 if (session == NULL) {
706 error = -ENOMEM;
707 goto end;
708 }
709 } else {
710 ps = l2tp_session_priv(session);
711 error = -EEXIST;
712 if (ps->sock != NULL)
713 goto end;
714
715 /* consistency checks */
716 if (ps->tunnel_sock != tunnel->sock)
717 goto end;
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 defined(CONFIG_L2TP_DEBUGFS) || defined(CONFIG_L2TP_DEBUGFS_MODULE)
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, PPPOL2TP_MSG_CONTROL, "%s: created\n",
779 session->name);
780
781 end:
782 release_sock(sk);
783
784 return error;
785 }
786
787 #ifdef CONFIG_L2TP_V3
788
789 /* Called when creating sessions via the netlink interface.
790 */
791 static int pppol2tp_session_create(struct net *net, u32 tunnel_id, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg)
792 {
793 int error;
794 struct l2tp_tunnel *tunnel;
795 struct l2tp_session *session;
796 struct pppol2tp_session *ps;
797
798 tunnel = l2tp_tunnel_find(net, tunnel_id);
799
800 /* Error if we can't find the tunnel */
801 error = -ENOENT;
802 if (tunnel == NULL)
803 goto out;
804
805 /* Error if tunnel socket is not prepped */
806 if (tunnel->sock == NULL)
807 goto out;
808
809 /* Check that this session doesn't already exist */
810 error = -EEXIST;
811 session = l2tp_session_find(net, tunnel, session_id);
812 if (session != NULL)
813 goto out;
814
815 /* Default MTU values. */
816 if (cfg->mtu == 0)
817 cfg->mtu = 1500 - PPPOL2TP_HEADER_OVERHEAD;
818 if (cfg->mru == 0)
819 cfg->mru = cfg->mtu;
820
821 /* Allocate and initialize a new session context. */
822 error = -ENOMEM;
823 session = l2tp_session_create(sizeof(struct pppol2tp_session),
824 tunnel, session_id,
825 peer_session_id, cfg);
826 if (session == NULL)
827 goto out;
828
829 ps = l2tp_session_priv(session);
830 ps->tunnel_sock = tunnel->sock;
831
832 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: created\n",
833 session->name);
834
835 error = 0;
836
837 out:
838 return error;
839 }
840
841 #endif /* CONFIG_L2TP_V3 */
842
843 /* getname() support.
844 */
845 static int pppol2tp_getname(struct socket *sock, struct sockaddr *uaddr,
846 int *usockaddr_len, int peer)
847 {
848 int len = 0;
849 int error = 0;
850 struct l2tp_session *session;
851 struct l2tp_tunnel *tunnel;
852 struct sock *sk = sock->sk;
853 struct inet_sock *inet;
854 struct pppol2tp_session *pls;
855
856 error = -ENOTCONN;
857 if (sk == NULL)
858 goto end;
859 if (!(sk->sk_state & PPPOX_CONNECTED))
860 goto end;
861
862 error = -EBADF;
863 session = pppol2tp_sock_to_session(sk);
864 if (session == NULL)
865 goto end;
866
867 pls = l2tp_session_priv(session);
868 tunnel = l2tp_sock_to_tunnel(pls->tunnel_sock);
869 if (tunnel == NULL)
870 goto end_put_sess;
871
872 inet = inet_sk(tunnel->sock);
873 if ((tunnel->version == 2) && (tunnel->sock->sk_family == AF_INET)) {
874 struct sockaddr_pppol2tp sp;
875 len = sizeof(sp);
876 memset(&sp, 0, len);
877 sp.sa_family = AF_PPPOX;
878 sp.sa_protocol = PX_PROTO_OL2TP;
879 sp.pppol2tp.fd = tunnel->fd;
880 sp.pppol2tp.pid = pls->owner;
881 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
882 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
883 sp.pppol2tp.s_session = session->session_id;
884 sp.pppol2tp.d_session = session->peer_session_id;
885 sp.pppol2tp.addr.sin_family = AF_INET;
886 sp.pppol2tp.addr.sin_port = inet->inet_dport;
887 sp.pppol2tp.addr.sin_addr.s_addr = inet->inet_daddr;
888 memcpy(uaddr, &sp, len);
889 #if IS_ENABLED(CONFIG_IPV6)
890 } else if ((tunnel->version == 2) &&
891 (tunnel->sock->sk_family == AF_INET6)) {
892 struct sockaddr_pppol2tpin6 sp;
893
894 len = sizeof(sp);
895 memset(&sp, 0, len);
896 sp.sa_family = AF_PPPOX;
897 sp.sa_protocol = PX_PROTO_OL2TP;
898 sp.pppol2tp.fd = tunnel->fd;
899 sp.pppol2tp.pid = pls->owner;
900 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
901 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
902 sp.pppol2tp.s_session = session->session_id;
903 sp.pppol2tp.d_session = session->peer_session_id;
904 sp.pppol2tp.addr.sin6_family = AF_INET6;
905 sp.pppol2tp.addr.sin6_port = inet->inet_dport;
906 memcpy(&sp.pppol2tp.addr.sin6_addr, &tunnel->sock->sk_v6_daddr,
907 sizeof(tunnel->sock->sk_v6_daddr));
908 memcpy(uaddr, &sp, len);
909 } else if ((tunnel->version == 3) &&
910 (tunnel->sock->sk_family == AF_INET6)) {
911 struct sockaddr_pppol2tpv3in6 sp;
912
913 len = sizeof(sp);
914 memset(&sp, 0, len);
915 sp.sa_family = AF_PPPOX;
916 sp.sa_protocol = PX_PROTO_OL2TP;
917 sp.pppol2tp.fd = tunnel->fd;
918 sp.pppol2tp.pid = pls->owner;
919 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
920 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
921 sp.pppol2tp.s_session = session->session_id;
922 sp.pppol2tp.d_session = session->peer_session_id;
923 sp.pppol2tp.addr.sin6_family = AF_INET6;
924 sp.pppol2tp.addr.sin6_port = inet->inet_dport;
925 memcpy(&sp.pppol2tp.addr.sin6_addr, &tunnel->sock->sk_v6_daddr,
926 sizeof(tunnel->sock->sk_v6_daddr));
927 memcpy(uaddr, &sp, len);
928 #endif
929 } else if (tunnel->version == 3) {
930 struct sockaddr_pppol2tpv3 sp;
931 len = sizeof(sp);
932 memset(&sp, 0, len);
933 sp.sa_family = AF_PPPOX;
934 sp.sa_protocol = PX_PROTO_OL2TP;
935 sp.pppol2tp.fd = tunnel->fd;
936 sp.pppol2tp.pid = pls->owner;
937 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
938 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
939 sp.pppol2tp.s_session = session->session_id;
940 sp.pppol2tp.d_session = session->peer_session_id;
941 sp.pppol2tp.addr.sin_family = AF_INET;
942 sp.pppol2tp.addr.sin_port = inet->inet_dport;
943 sp.pppol2tp.addr.sin_addr.s_addr = inet->inet_daddr;
944 memcpy(uaddr, &sp, len);
945 }
946
947 *usockaddr_len = len;
948 error = 0;
949
950 sock_put(pls->tunnel_sock);
951 end_put_sess:
952 sock_put(sk);
953 end:
954 return error;
955 }
956
957 /****************************************************************************
958 * ioctl() handlers.
959 *
960 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
961 * sockets. However, in order to control kernel tunnel features, we allow
962 * userspace to create a special "tunnel" PPPoX socket which is used for
963 * control only. Tunnel PPPoX sockets have session_id == 0 and simply allow
964 * the user application to issue L2TP setsockopt(), getsockopt() and ioctl()
965 * calls.
966 ****************************************************************************/
967
968 static void pppol2tp_copy_stats(struct pppol2tp_ioc_stats *dest,
969 struct l2tp_stats *stats)
970 {
971 dest->tx_packets = atomic_long_read(&stats->tx_packets);
972 dest->tx_bytes = atomic_long_read(&stats->tx_bytes);
973 dest->tx_errors = atomic_long_read(&stats->tx_errors);
974 dest->rx_packets = atomic_long_read(&stats->rx_packets);
975 dest->rx_bytes = atomic_long_read(&stats->rx_bytes);
976 dest->rx_seq_discards = atomic_long_read(&stats->rx_seq_discards);
977 dest->rx_oos_packets = atomic_long_read(&stats->rx_oos_packets);
978 dest->rx_errors = atomic_long_read(&stats->rx_errors);
979 }
980
981 /* Session ioctl helper.
982 */
983 static int pppol2tp_session_ioctl(struct l2tp_session *session,
984 unsigned int cmd, unsigned long arg)
985 {
986 struct ifreq ifr;
987 int err = 0;
988 struct sock *sk;
989 int val = (int) arg;
990 struct pppol2tp_session *ps = l2tp_session_priv(session);
991 struct l2tp_tunnel *tunnel = session->tunnel;
992 struct pppol2tp_ioc_stats stats;
993
994 l2tp_dbg(session, PPPOL2TP_MSG_CONTROL,
995 "%s: pppol2tp_session_ioctl(cmd=%#x, arg=%#lx)\n",
996 session->name, cmd, arg);
997
998 sk = ps->sock;
999 sock_hold(sk);
1000
1001 switch (cmd) {
1002 case SIOCGIFMTU:
1003 err = -ENXIO;
1004 if (!(sk->sk_state & PPPOX_CONNECTED))
1005 break;
1006
1007 err = -EFAULT;
1008 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq)))
1009 break;
1010 ifr.ifr_mtu = session->mtu;
1011 if (copy_to_user((void __user *) arg, &ifr, sizeof(struct ifreq)))
1012 break;
1013
1014 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: get mtu=%d\n",
1015 session->name, session->mtu);
1016 err = 0;
1017 break;
1018
1019 case SIOCSIFMTU:
1020 err = -ENXIO;
1021 if (!(sk->sk_state & PPPOX_CONNECTED))
1022 break;
1023
1024 err = -EFAULT;
1025 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq)))
1026 break;
1027
1028 session->mtu = ifr.ifr_mtu;
1029
1030 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: set mtu=%d\n",
1031 session->name, session->mtu);
1032 err = 0;
1033 break;
1034
1035 case PPPIOCGMRU:
1036 err = -ENXIO;
1037 if (!(sk->sk_state & PPPOX_CONNECTED))
1038 break;
1039
1040 err = -EFAULT;
1041 if (put_user(session->mru, (int __user *) arg))
1042 break;
1043
1044 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: get mru=%d\n",
1045 session->name, session->mru);
1046 err = 0;
1047 break;
1048
1049 case PPPIOCSMRU:
1050 err = -ENXIO;
1051 if (!(sk->sk_state & PPPOX_CONNECTED))
1052 break;
1053
1054 err = -EFAULT;
1055 if (get_user(val, (int __user *) arg))
1056 break;
1057
1058 session->mru = val;
1059 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: set mru=%d\n",
1060 session->name, session->mru);
1061 err = 0;
1062 break;
1063
1064 case PPPIOCGFLAGS:
1065 err = -EFAULT;
1066 if (put_user(ps->flags, (int __user *) arg))
1067 break;
1068
1069 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: get flags=%d\n",
1070 session->name, ps->flags);
1071 err = 0;
1072 break;
1073
1074 case PPPIOCSFLAGS:
1075 err = -EFAULT;
1076 if (get_user(val, (int __user *) arg))
1077 break;
1078 ps->flags = val;
1079 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: set flags=%d\n",
1080 session->name, ps->flags);
1081 err = 0;
1082 break;
1083
1084 case PPPIOCGL2TPSTATS:
1085 err = -ENXIO;
1086 if (!(sk->sk_state & PPPOX_CONNECTED))
1087 break;
1088
1089 memset(&stats, 0, sizeof(stats));
1090 stats.tunnel_id = tunnel->tunnel_id;
1091 stats.session_id = session->session_id;
1092 pppol2tp_copy_stats(&stats, &session->stats);
1093 if (copy_to_user((void __user *) arg, &stats,
1094 sizeof(stats)))
1095 break;
1096 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: get L2TP stats\n",
1097 session->name);
1098 err = 0;
1099 break;
1100
1101 default:
1102 err = -ENOSYS;
1103 break;
1104 }
1105
1106 sock_put(sk);
1107
1108 return err;
1109 }
1110
1111 /* Tunnel ioctl helper.
1112 *
1113 * Note the special handling for PPPIOCGL2TPSTATS below. If the ioctl data
1114 * specifies a session_id, the session ioctl handler is called. This allows an
1115 * application to retrieve session stats via a tunnel socket.
1116 */
1117 static int pppol2tp_tunnel_ioctl(struct l2tp_tunnel *tunnel,
1118 unsigned int cmd, unsigned long arg)
1119 {
1120 int err = 0;
1121 struct sock *sk;
1122 struct pppol2tp_ioc_stats stats;
1123
1124 l2tp_dbg(tunnel, PPPOL2TP_MSG_CONTROL,
1125 "%s: pppol2tp_tunnel_ioctl(cmd=%#x, arg=%#lx)\n",
1126 tunnel->name, cmd, arg);
1127
1128 sk = tunnel->sock;
1129 sock_hold(sk);
1130
1131 switch (cmd) {
1132 case PPPIOCGL2TPSTATS:
1133 err = -ENXIO;
1134 if (!(sk->sk_state & PPPOX_CONNECTED))
1135 break;
1136
1137 if (copy_from_user(&stats, (void __user *) arg,
1138 sizeof(stats))) {
1139 err = -EFAULT;
1140 break;
1141 }
1142 if (stats.session_id != 0) {
1143 /* resend to session ioctl handler */
1144 struct l2tp_session *session =
1145 l2tp_session_find(sock_net(sk), tunnel, stats.session_id);
1146 if (session != NULL)
1147 err = pppol2tp_session_ioctl(session, cmd, arg);
1148 else
1149 err = -EBADR;
1150 break;
1151 }
1152 #ifdef CONFIG_XFRM
1153 stats.using_ipsec = (sk->sk_policy[0] || sk->sk_policy[1]) ? 1 : 0;
1154 #endif
1155 pppol2tp_copy_stats(&stats, &tunnel->stats);
1156 if (copy_to_user((void __user *) arg, &stats, sizeof(stats))) {
1157 err = -EFAULT;
1158 break;
1159 }
1160 l2tp_info(tunnel, PPPOL2TP_MSG_CONTROL, "%s: get L2TP stats\n",
1161 tunnel->name);
1162 err = 0;
1163 break;
1164
1165 default:
1166 err = -ENOSYS;
1167 break;
1168 }
1169
1170 sock_put(sk);
1171
1172 return err;
1173 }
1174
1175 /* Main ioctl() handler.
1176 * Dispatch to tunnel or session helpers depending on the socket.
1177 */
1178 static int pppol2tp_ioctl(struct socket *sock, unsigned int cmd,
1179 unsigned long arg)
1180 {
1181 struct sock *sk = sock->sk;
1182 struct l2tp_session *session;
1183 struct l2tp_tunnel *tunnel;
1184 struct pppol2tp_session *ps;
1185 int err;
1186
1187 if (!sk)
1188 return 0;
1189
1190 err = -EBADF;
1191 if (sock_flag(sk, SOCK_DEAD) != 0)
1192 goto end;
1193
1194 err = -ENOTCONN;
1195 if ((sk->sk_user_data == NULL) ||
1196 (!(sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND))))
1197 goto end;
1198
1199 /* Get session context from the socket */
1200 err = -EBADF;
1201 session = pppol2tp_sock_to_session(sk);
1202 if (session == NULL)
1203 goto end;
1204
1205 /* Special case: if session's session_id is zero, treat ioctl as a
1206 * tunnel ioctl
1207 */
1208 ps = l2tp_session_priv(session);
1209 if ((session->session_id == 0) &&
1210 (session->peer_session_id == 0)) {
1211 err = -EBADF;
1212 tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock);
1213 if (tunnel == NULL)
1214 goto end_put_sess;
1215
1216 err = pppol2tp_tunnel_ioctl(tunnel, cmd, arg);
1217 sock_put(ps->tunnel_sock);
1218 goto end_put_sess;
1219 }
1220
1221 err = pppol2tp_session_ioctl(session, cmd, arg);
1222
1223 end_put_sess:
1224 sock_put(sk);
1225 end:
1226 return err;
1227 }
1228
1229 /*****************************************************************************
1230 * setsockopt() / getsockopt() support.
1231 *
1232 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
1233 * sockets. In order to control kernel tunnel features, we allow userspace to
1234 * create a special "tunnel" PPPoX socket which is used for control only.
1235 * Tunnel PPPoX sockets have session_id == 0 and simply allow the user
1236 * application to issue L2TP setsockopt(), getsockopt() and ioctl() calls.
1237 *****************************************************************************/
1238
1239 /* Tunnel setsockopt() helper.
1240 */
1241 static int pppol2tp_tunnel_setsockopt(struct sock *sk,
1242 struct l2tp_tunnel *tunnel,
1243 int optname, int val)
1244 {
1245 int err = 0;
1246
1247 switch (optname) {
1248 case PPPOL2TP_SO_DEBUG:
1249 tunnel->debug = val;
1250 l2tp_info(tunnel, PPPOL2TP_MSG_CONTROL, "%s: set debug=%x\n",
1251 tunnel->name, tunnel->debug);
1252 break;
1253
1254 default:
1255 err = -ENOPROTOOPT;
1256 break;
1257 }
1258
1259 return err;
1260 }
1261
1262 /* Session setsockopt helper.
1263 */
1264 static int pppol2tp_session_setsockopt(struct sock *sk,
1265 struct l2tp_session *session,
1266 int optname, int val)
1267 {
1268 int err = 0;
1269 struct pppol2tp_session *ps = l2tp_session_priv(session);
1270
1271 switch (optname) {
1272 case PPPOL2TP_SO_RECVSEQ:
1273 if ((val != 0) && (val != 1)) {
1274 err = -EINVAL;
1275 break;
1276 }
1277 session->recv_seq = val ? -1 : 0;
1278 l2tp_info(session, PPPOL2TP_MSG_CONTROL,
1279 "%s: set recv_seq=%d\n",
1280 session->name, session->recv_seq);
1281 break;
1282
1283 case PPPOL2TP_SO_SENDSEQ:
1284 if ((val != 0) && (val != 1)) {
1285 err = -EINVAL;
1286 break;
1287 }
1288 session->send_seq = val ? -1 : 0;
1289 {
1290 struct sock *ssk = ps->sock;
1291 struct pppox_sock *po = pppox_sk(ssk);
1292 po->chan.hdrlen = val ? PPPOL2TP_L2TP_HDR_SIZE_SEQ :
1293 PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
1294 }
1295 l2tp_session_set_header_len(session, session->tunnel->version);
1296 l2tp_info(session, PPPOL2TP_MSG_CONTROL,
1297 "%s: set send_seq=%d\n",
1298 session->name, session->send_seq);
1299 break;
1300
1301 case PPPOL2TP_SO_LNSMODE:
1302 if ((val != 0) && (val != 1)) {
1303 err = -EINVAL;
1304 break;
1305 }
1306 session->lns_mode = val ? -1 : 0;
1307 l2tp_info(session, PPPOL2TP_MSG_CONTROL,
1308 "%s: set lns_mode=%d\n",
1309 session->name, session->lns_mode);
1310 break;
1311
1312 case PPPOL2TP_SO_DEBUG:
1313 session->debug = val;
1314 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: set debug=%x\n",
1315 session->name, session->debug);
1316 break;
1317
1318 case PPPOL2TP_SO_REORDERTO:
1319 session->reorder_timeout = msecs_to_jiffies(val);
1320 l2tp_info(session, PPPOL2TP_MSG_CONTROL,
1321 "%s: set reorder_timeout=%d\n",
1322 session->name, session->reorder_timeout);
1323 break;
1324
1325 default:
1326 err = -ENOPROTOOPT;
1327 break;
1328 }
1329
1330 return err;
1331 }
1332
1333 /* Main setsockopt() entry point.
1334 * Does API checks, then calls either the tunnel or session setsockopt
1335 * handler, according to whether the PPPoL2TP socket is a for a regular
1336 * session or the special tunnel type.
1337 */
1338 static int pppol2tp_setsockopt(struct socket *sock, int level, int optname,
1339 char __user *optval, unsigned int optlen)
1340 {
1341 struct sock *sk = sock->sk;
1342 struct l2tp_session *session;
1343 struct l2tp_tunnel *tunnel;
1344 struct pppol2tp_session *ps;
1345 int val;
1346 int err;
1347
1348 if (level != SOL_PPPOL2TP)
1349 return -EINVAL;
1350
1351 if (optlen < sizeof(int))
1352 return -EINVAL;
1353
1354 if (get_user(val, (int __user *)optval))
1355 return -EFAULT;
1356
1357 err = -ENOTCONN;
1358 if (sk->sk_user_data == NULL)
1359 goto end;
1360
1361 /* Get session context from the socket */
1362 err = -EBADF;
1363 session = pppol2tp_sock_to_session(sk);
1364 if (session == NULL)
1365 goto end;
1366
1367 /* Special case: if session_id == 0x0000, treat as operation on tunnel
1368 */
1369 ps = l2tp_session_priv(session);
1370 if ((session->session_id == 0) &&
1371 (session->peer_session_id == 0)) {
1372 err = -EBADF;
1373 tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock);
1374 if (tunnel == NULL)
1375 goto end_put_sess;
1376
1377 err = pppol2tp_tunnel_setsockopt(sk, tunnel, optname, val);
1378 sock_put(ps->tunnel_sock);
1379 } else
1380 err = pppol2tp_session_setsockopt(sk, session, optname, val);
1381
1382 err = 0;
1383
1384 end_put_sess:
1385 sock_put(sk);
1386 end:
1387 return err;
1388 }
1389
1390 /* Tunnel getsockopt helper. Called with sock locked.
1391 */
1392 static int pppol2tp_tunnel_getsockopt(struct sock *sk,
1393 struct l2tp_tunnel *tunnel,
1394 int optname, int *val)
1395 {
1396 int err = 0;
1397
1398 switch (optname) {
1399 case PPPOL2TP_SO_DEBUG:
1400 *val = tunnel->debug;
1401 l2tp_info(tunnel, PPPOL2TP_MSG_CONTROL, "%s: get debug=%x\n",
1402 tunnel->name, tunnel->debug);
1403 break;
1404
1405 default:
1406 err = -ENOPROTOOPT;
1407 break;
1408 }
1409
1410 return err;
1411 }
1412
1413 /* Session getsockopt helper. Called with sock locked.
1414 */
1415 static int pppol2tp_session_getsockopt(struct sock *sk,
1416 struct l2tp_session *session,
1417 int optname, int *val)
1418 {
1419 int err = 0;
1420
1421 switch (optname) {
1422 case PPPOL2TP_SO_RECVSEQ:
1423 *val = session->recv_seq;
1424 l2tp_info(session, PPPOL2TP_MSG_CONTROL,
1425 "%s: get recv_seq=%d\n", session->name, *val);
1426 break;
1427
1428 case PPPOL2TP_SO_SENDSEQ:
1429 *val = session->send_seq;
1430 l2tp_info(session, PPPOL2TP_MSG_CONTROL,
1431 "%s: get send_seq=%d\n", session->name, *val);
1432 break;
1433
1434 case PPPOL2TP_SO_LNSMODE:
1435 *val = session->lns_mode;
1436 l2tp_info(session, PPPOL2TP_MSG_CONTROL,
1437 "%s: get lns_mode=%d\n", session->name, *val);
1438 break;
1439
1440 case PPPOL2TP_SO_DEBUG:
1441 *val = session->debug;
1442 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: get debug=%d\n",
1443 session->name, *val);
1444 break;
1445
1446 case PPPOL2TP_SO_REORDERTO:
1447 *val = (int) jiffies_to_msecs(session->reorder_timeout);
1448 l2tp_info(session, PPPOL2TP_MSG_CONTROL,
1449 "%s: get reorder_timeout=%d\n", session->name, *val);
1450 break;
1451
1452 default:
1453 err = -ENOPROTOOPT;
1454 }
1455
1456 return err;
1457 }
1458
1459 /* Main getsockopt() entry point.
1460 * Does API checks, then calls either the tunnel or session getsockopt
1461 * handler, according to whether the PPPoX socket is a for a regular session
1462 * or the special tunnel type.
1463 */
1464 static int pppol2tp_getsockopt(struct socket *sock, int level, int optname,
1465 char __user *optval, int __user *optlen)
1466 {
1467 struct sock *sk = sock->sk;
1468 struct l2tp_session *session;
1469 struct l2tp_tunnel *tunnel;
1470 int val, len;
1471 int err;
1472 struct pppol2tp_session *ps;
1473
1474 if (level != SOL_PPPOL2TP)
1475 return -EINVAL;
1476
1477 if (get_user(len, optlen))
1478 return -EFAULT;
1479
1480 len = min_t(unsigned int, len, sizeof(int));
1481
1482 if (len < 0)
1483 return -EINVAL;
1484
1485 err = -ENOTCONN;
1486 if (sk->sk_user_data == NULL)
1487 goto end;
1488
1489 /* Get the session context */
1490 err = -EBADF;
1491 session = pppol2tp_sock_to_session(sk);
1492 if (session == NULL)
1493 goto end;
1494
1495 /* Special case: if session_id == 0x0000, treat as operation on tunnel */
1496 ps = l2tp_session_priv(session);
1497 if ((session->session_id == 0) &&
1498 (session->peer_session_id == 0)) {
1499 err = -EBADF;
1500 tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock);
1501 if (tunnel == NULL)
1502 goto end_put_sess;
1503
1504 err = pppol2tp_tunnel_getsockopt(sk, tunnel, optname, &val);
1505 sock_put(ps->tunnel_sock);
1506 } else
1507 err = pppol2tp_session_getsockopt(sk, session, optname, &val);
1508
1509 err = -EFAULT;
1510 if (put_user(len, optlen))
1511 goto end_put_sess;
1512
1513 if (copy_to_user((void __user *) optval, &val, len))
1514 goto end_put_sess;
1515
1516 err = 0;
1517
1518 end_put_sess:
1519 sock_put(sk);
1520 end:
1521 return err;
1522 }
1523
1524 /*****************************************************************************
1525 * /proc filesystem for debug
1526 * Since the original pppol2tp driver provided /proc/net/pppol2tp for
1527 * L2TPv2, we dump only L2TPv2 tunnels and sessions here.
1528 *****************************************************************************/
1529
1530 static unsigned int pppol2tp_net_id;
1531
1532 #ifdef CONFIG_PROC_FS
1533
1534 struct pppol2tp_seq_data {
1535 struct seq_net_private p;
1536 int tunnel_idx; /* current tunnel */
1537 int session_idx; /* index of session within current tunnel */
1538 struct l2tp_tunnel *tunnel;
1539 struct l2tp_session *session; /* NULL means get next tunnel */
1540 };
1541
1542 static void pppol2tp_next_tunnel(struct net *net, struct pppol2tp_seq_data *pd)
1543 {
1544 for (;;) {
1545 pd->tunnel = l2tp_tunnel_find_nth(net, pd->tunnel_idx);
1546 pd->tunnel_idx++;
1547
1548 if (pd->tunnel == NULL)
1549 break;
1550
1551 /* Ignore L2TPv3 tunnels */
1552 if (pd->tunnel->version < 3)
1553 break;
1554 }
1555 }
1556
1557 static void pppol2tp_next_session(struct net *net, struct pppol2tp_seq_data *pd)
1558 {
1559 pd->session = l2tp_session_find_nth(pd->tunnel, pd->session_idx);
1560 pd->session_idx++;
1561
1562 if (pd->session == NULL) {
1563 pd->session_idx = 0;
1564 pppol2tp_next_tunnel(net, pd);
1565 }
1566 }
1567
1568 static void *pppol2tp_seq_start(struct seq_file *m, loff_t *offs)
1569 {
1570 struct pppol2tp_seq_data *pd = SEQ_START_TOKEN;
1571 loff_t pos = *offs;
1572 struct net *net;
1573
1574 if (!pos)
1575 goto out;
1576
1577 BUG_ON(m->private == NULL);
1578 pd = m->private;
1579 net = seq_file_net(m);
1580
1581 if (pd->tunnel == NULL)
1582 pppol2tp_next_tunnel(net, pd);
1583 else
1584 pppol2tp_next_session(net, pd);
1585
1586 /* NULL tunnel and session indicates end of list */
1587 if ((pd->tunnel == NULL) && (pd->session == NULL))
1588 pd = NULL;
1589
1590 out:
1591 return pd;
1592 }
1593
1594 static void *pppol2tp_seq_next(struct seq_file *m, void *v, loff_t *pos)
1595 {
1596 (*pos)++;
1597 return NULL;
1598 }
1599
1600 static void pppol2tp_seq_stop(struct seq_file *p, void *v)
1601 {
1602 /* nothing to do */
1603 }
1604
1605 static void pppol2tp_seq_tunnel_show(struct seq_file *m, void *v)
1606 {
1607 struct l2tp_tunnel *tunnel = v;
1608
1609 seq_printf(m, "\nTUNNEL '%s', %c %d\n",
1610 tunnel->name,
1611 (tunnel == tunnel->sock->sk_user_data) ? 'Y' : 'N',
1612 atomic_read(&tunnel->ref_count) - 1);
1613 seq_printf(m, " %08x %ld/%ld/%ld %ld/%ld/%ld\n",
1614 tunnel->debug,
1615 atomic_long_read(&tunnel->stats.tx_packets),
1616 atomic_long_read(&tunnel->stats.tx_bytes),
1617 atomic_long_read(&tunnel->stats.tx_errors),
1618 atomic_long_read(&tunnel->stats.rx_packets),
1619 atomic_long_read(&tunnel->stats.rx_bytes),
1620 atomic_long_read(&tunnel->stats.rx_errors));
1621 }
1622
1623 static void pppol2tp_seq_session_show(struct seq_file *m, void *v)
1624 {
1625 struct l2tp_session *session = v;
1626 struct l2tp_tunnel *tunnel = session->tunnel;
1627 struct pppol2tp_session *ps = l2tp_session_priv(session);
1628 struct pppox_sock *po = pppox_sk(ps->sock);
1629 u32 ip = 0;
1630 u16 port = 0;
1631
1632 if (tunnel->sock) {
1633 struct inet_sock *inet = inet_sk(tunnel->sock);
1634 ip = ntohl(inet->inet_saddr);
1635 port = ntohs(inet->inet_sport);
1636 }
1637
1638 seq_printf(m, " SESSION '%s' %08X/%d %04X/%04X -> "
1639 "%04X/%04X %d %c\n",
1640 session->name, ip, port,
1641 tunnel->tunnel_id,
1642 session->session_id,
1643 tunnel->peer_tunnel_id,
1644 session->peer_session_id,
1645 ps->sock->sk_state,
1646 (session == ps->sock->sk_user_data) ?
1647 'Y' : 'N');
1648 seq_printf(m, " %d/%d/%c/%c/%s %08x %u\n",
1649 session->mtu, session->mru,
1650 session->recv_seq ? 'R' : '-',
1651 session->send_seq ? 'S' : '-',
1652 session->lns_mode ? "LNS" : "LAC",
1653 session->debug,
1654 jiffies_to_msecs(session->reorder_timeout));
1655 seq_printf(m, " %hu/%hu %ld/%ld/%ld %ld/%ld/%ld\n",
1656 session->nr, session->ns,
1657 atomic_long_read(&session->stats.tx_packets),
1658 atomic_long_read(&session->stats.tx_bytes),
1659 atomic_long_read(&session->stats.tx_errors),
1660 atomic_long_read(&session->stats.rx_packets),
1661 atomic_long_read(&session->stats.rx_bytes),
1662 atomic_long_read(&session->stats.rx_errors));
1663
1664 if (po)
1665 seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan));
1666 }
1667
1668 static int pppol2tp_seq_show(struct seq_file *m, void *v)
1669 {
1670 struct pppol2tp_seq_data *pd = v;
1671
1672 /* display header on line 1 */
1673 if (v == SEQ_START_TOKEN) {
1674 seq_puts(m, "PPPoL2TP driver info, " PPPOL2TP_DRV_VERSION "\n");
1675 seq_puts(m, "TUNNEL name, user-data-ok session-count\n");
1676 seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
1677 seq_puts(m, " SESSION name, addr/port src-tid/sid "
1678 "dest-tid/sid state user-data-ok\n");
1679 seq_puts(m, " mtu/mru/rcvseq/sendseq/lns debug reorderto\n");
1680 seq_puts(m, " nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
1681 goto out;
1682 }
1683
1684 /* Show the tunnel or session context.
1685 */
1686 if (pd->session == NULL)
1687 pppol2tp_seq_tunnel_show(m, pd->tunnel);
1688 else
1689 pppol2tp_seq_session_show(m, pd->session);
1690
1691 out:
1692 return 0;
1693 }
1694
1695 static const struct seq_operations pppol2tp_seq_ops = {
1696 .start = pppol2tp_seq_start,
1697 .next = pppol2tp_seq_next,
1698 .stop = pppol2tp_seq_stop,
1699 .show = pppol2tp_seq_show,
1700 };
1701
1702 /* Called when our /proc file is opened. We allocate data for use when
1703 * iterating our tunnel / session contexts and store it in the private
1704 * data of the seq_file.
1705 */
1706 static int pppol2tp_proc_open(struct inode *inode, struct file *file)
1707 {
1708 return seq_open_net(inode, file, &pppol2tp_seq_ops,
1709 sizeof(struct pppol2tp_seq_data));
1710 }
1711
1712 static const struct file_operations pppol2tp_proc_fops = {
1713 .owner = THIS_MODULE,
1714 .open = pppol2tp_proc_open,
1715 .read = seq_read,
1716 .llseek = seq_lseek,
1717 .release = seq_release_net,
1718 };
1719
1720 #endif /* CONFIG_PROC_FS */
1721
1722 /*****************************************************************************
1723 * Network namespace
1724 *****************************************************************************/
1725
1726 static __net_init int pppol2tp_init_net(struct net *net)
1727 {
1728 struct proc_dir_entry *pde;
1729 int err = 0;
1730
1731 pde = proc_create("pppol2tp", S_IRUGO, net->proc_net,
1732 &pppol2tp_proc_fops);
1733 if (!pde) {
1734 err = -ENOMEM;
1735 goto out;
1736 }
1737
1738 out:
1739 return err;
1740 }
1741
1742 static __net_exit void pppol2tp_exit_net(struct net *net)
1743 {
1744 remove_proc_entry("pppol2tp", net->proc_net);
1745 }
1746
1747 static struct pernet_operations pppol2tp_net_ops = {
1748 .init = pppol2tp_init_net,
1749 .exit = pppol2tp_exit_net,
1750 .id = &pppol2tp_net_id,
1751 };
1752
1753 /*****************************************************************************
1754 * Init and cleanup
1755 *****************************************************************************/
1756
1757 static const struct proto_ops pppol2tp_ops = {
1758 .family = AF_PPPOX,
1759 .owner = THIS_MODULE,
1760 .release = pppol2tp_release,
1761 .bind = sock_no_bind,
1762 .connect = pppol2tp_connect,
1763 .socketpair = sock_no_socketpair,
1764 .accept = sock_no_accept,
1765 .getname = pppol2tp_getname,
1766 .poll = datagram_poll,
1767 .listen = sock_no_listen,
1768 .shutdown = sock_no_shutdown,
1769 .setsockopt = pppol2tp_setsockopt,
1770 .getsockopt = pppol2tp_getsockopt,
1771 .sendmsg = pppol2tp_sendmsg,
1772 .recvmsg = pppol2tp_recvmsg,
1773 .mmap = sock_no_mmap,
1774 .ioctl = pppox_ioctl,
1775 };
1776
1777 static const struct pppox_proto pppol2tp_proto = {
1778 .create = pppol2tp_create,
1779 .ioctl = pppol2tp_ioctl,
1780 .owner = THIS_MODULE,
1781 };
1782
1783 #ifdef CONFIG_L2TP_V3
1784
1785 static const struct l2tp_nl_cmd_ops pppol2tp_nl_cmd_ops = {
1786 .session_create = pppol2tp_session_create,
1787 .session_delete = l2tp_session_delete,
1788 };
1789
1790 #endif /* CONFIG_L2TP_V3 */
1791
1792 static int __init pppol2tp_init(void)
1793 {
1794 int err;
1795
1796 err = register_pernet_device(&pppol2tp_net_ops);
1797 if (err)
1798 goto out;
1799
1800 err = proto_register(&pppol2tp_sk_proto, 0);
1801 if (err)
1802 goto out_unregister_pppol2tp_pernet;
1803
1804 err = register_pppox_proto(PX_PROTO_OL2TP, &pppol2tp_proto);
1805 if (err)
1806 goto out_unregister_pppol2tp_proto;
1807
1808 #ifdef CONFIG_L2TP_V3
1809 err = l2tp_nl_register_ops(L2TP_PWTYPE_PPP, &pppol2tp_nl_cmd_ops);
1810 if (err)
1811 goto out_unregister_pppox;
1812 #endif
1813
1814 pr_info("PPPoL2TP kernel driver, %s\n", PPPOL2TP_DRV_VERSION);
1815
1816 out:
1817 return err;
1818
1819 #ifdef CONFIG_L2TP_V3
1820 out_unregister_pppox:
1821 unregister_pppox_proto(PX_PROTO_OL2TP);
1822 #endif
1823 out_unregister_pppol2tp_proto:
1824 proto_unregister(&pppol2tp_sk_proto);
1825 out_unregister_pppol2tp_pernet:
1826 unregister_pernet_device(&pppol2tp_net_ops);
1827 goto out;
1828 }
1829
1830 static void __exit pppol2tp_exit(void)
1831 {
1832 #ifdef CONFIG_L2TP_V3
1833 l2tp_nl_unregister_ops(L2TP_PWTYPE_PPP);
1834 #endif
1835 unregister_pppox_proto(PX_PROTO_OL2TP);
1836 proto_unregister(&pppol2tp_sk_proto);
1837 unregister_pernet_device(&pppol2tp_net_ops);
1838 }
1839
1840 module_init(pppol2tp_init);
1841 module_exit(pppol2tp_exit);
1842
1843 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
1844 MODULE_DESCRIPTION("PPP over L2TP over UDP");
1845 MODULE_LICENSE("GPL");
1846 MODULE_VERSION(PPPOL2TP_DRV_VERSION);
1847 MODULE_ALIAS_NET_PF_PROTO(PF_PPPOX, PX_PROTO_OL2TP);
1848 MODULE_ALIAS_L2TP_PWTYPE(11);
Linux with added FPC-III support