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Bluetooth: Properly check L2CAP config option output buffer length
[linux/fpc-iii.git] / net / l2tp / l2tp_ppp.c
blob50e3ee9a9d612e6c033ef761d8dfeb1e6f209541
1 /*****************************************************************************
2 * Linux PPP over L2TP (PPPoX/PPPoL2TP) Sockets
3 *
4 * PPPoX --- Generic PPP encapsulation socket family
5 * PPPoL2TP --- PPP over L2TP (RFC 2661)
6 *
7 * Version: 2.0.0
8 *
9 * Authors: James Chapman (jchapman@katalix.com)
10 *
11 * Based on original work by Martijn van Oosterhout <kleptog@svana.org>
12 *
13 * License:
14 * This program is free software; you can redistribute it and/or
15 * modify it under the terms of the GNU General Public License
16 * as published by the Free Software Foundation; either version
17 * 2 of the License, or (at your option) any later version.
18 *
19 */
20
21 /* This driver handles only L2TP data frames; control frames are handled by a
22 * userspace application.
23 *
24 * To send data in an L2TP session, userspace opens a PPPoL2TP socket and
25 * attaches it to a bound UDP socket with local tunnel_id / session_id and
26 * peer tunnel_id / session_id set. Data can then be sent or received using
27 * regular socket sendmsg() / recvmsg() calls. Kernel parameters of the socket
28 * can be read or modified using ioctl() or [gs]etsockopt() calls.
29 *
30 * When a PPPoL2TP socket is connected with local and peer session_id values
31 * zero, the socket is treated as a special tunnel management socket.
32 *
33 * Here's example userspace code to create a socket for sending/receiving data
34 * over an L2TP session:-
35 *
36 * struct sockaddr_pppol2tp sax;
37 * int fd;
38 * int session_fd;
39 *
40 * fd = socket(AF_PPPOX, SOCK_DGRAM, PX_PROTO_OL2TP);
41 *
42 * sax.sa_family = AF_PPPOX;
43 * sax.sa_protocol = PX_PROTO_OL2TP;
44 * sax.pppol2tp.fd = tunnel_fd; // bound UDP socket
45 * sax.pppol2tp.addr.sin_addr.s_addr = addr->sin_addr.s_addr;
46 * sax.pppol2tp.addr.sin_port = addr->sin_port;
47 * sax.pppol2tp.addr.sin_family = AF_INET;
48 * sax.pppol2tp.s_tunnel = tunnel_id;
49 * sax.pppol2tp.s_session = session_id;
50 * sax.pppol2tp.d_tunnel = peer_tunnel_id;
51 * sax.pppol2tp.d_session = peer_session_id;
52 *
53 * session_fd = connect(fd, (struct sockaddr *)&sax, sizeof(sax));
54 *
55 * A pppd plugin that allows PPP traffic to be carried over L2TP using
56 * this driver is available from the OpenL2TP project at
57 * http://openl2tp.sourceforge.net.
58 */
59
60 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
61
62 #include <linux/module.h>
63 #include <linux/string.h>
64 #include <linux/list.h>
65 #include <linux/uaccess.h>
66
67 #include <linux/kernel.h>
68 #include <linux/spinlock.h>
69 #include <linux/kthread.h>
70 #include <linux/sched.h>
71 #include <linux/slab.h>
72 #include <linux/errno.h>
73 #include <linux/jiffies.h>
74
75 #include <linux/netdevice.h>
76 #include <linux/net.h>
77 #include <linux/inetdevice.h>
78 #include <linux/skbuff.h>
79 #include <linux/init.h>
80 #include <linux/ip.h>
81 #include <linux/udp.h>
82 #include <linux/if_pppox.h>
83 #include <linux/if_pppol2tp.h>
84 #include <net/sock.h>
85 #include <linux/ppp_channel.h>
86 #include <linux/ppp_defs.h>
87 #include <linux/ppp-ioctl.h>
88 #include <linux/file.h>
89 #include <linux/hash.h>
90 #include <linux/sort.h>
91 #include <linux/proc_fs.h>
92 #include <linux/l2tp.h>
93 #include <linux/nsproxy.h>
94 #include <net/net_namespace.h>
95 #include <net/netns/generic.h>
96 #include <net/dst.h>
97 #include <net/ip.h>
98 #include <net/udp.h>
99 #include <net/xfrm.h>
100 #include <net/inet_common.h>
101
102 #include <asm/byteorder.h>
103 #include <linux/atomic.h>
104
105 #include "l2tp_core.h"
106
107 #define PPPOL2TP_DRV_VERSION "V2.0"
108
109 /* Space for UDP, L2TP and PPP headers */
110 #define PPPOL2TP_HEADER_OVERHEAD 40
111
112 /* Number of bytes to build transmit L2TP headers.
113 * Unfortunately the size is different depending on whether sequence numbers
114 * are enabled.
115 */
116 #define PPPOL2TP_L2TP_HDR_SIZE_SEQ 10
117 #define PPPOL2TP_L2TP_HDR_SIZE_NOSEQ 6
118
119 /* Private data of each session. This data lives at the end of struct
120 * l2tp_session, referenced via session->priv[].
121 */
122 struct pppol2tp_session {
123 int owner; /* pid that opened the socket */
124
125 struct sock *sock; /* Pointer to the session
126 * PPPoX socket */
127 struct sock *tunnel_sock; /* Pointer to the tunnel UDP
128 * socket */
129 int flags; /* accessed by PPPIOCGFLAGS.
130 * Unused. */
131 };
132
133 static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb);
134
135 static const struct ppp_channel_ops pppol2tp_chan_ops = {
136 .start_xmit = pppol2tp_xmit,
137 };
138
139 static const struct proto_ops pppol2tp_ops;
140
141 /* Helpers to obtain tunnel/session contexts from sockets.
142 */
143 static inline struct l2tp_session *pppol2tp_sock_to_session(struct sock *sk)
144 {
145 struct l2tp_session *session;
146
147 if (sk == NULL)
148 return NULL;
149
150 sock_hold(sk);
151 session = (struct l2tp_session *)(sk->sk_user_data);
152 if (session == NULL) {
153 sock_put(sk);
154 goto out;
155 }
156
157 BUG_ON(session->magic != L2TP_SESSION_MAGIC);
158
159 out:
160 return session;
161 }
162
163 /*****************************************************************************
164 * Receive data handling
165 *****************************************************************************/
166
167 static int pppol2tp_recv_payload_hook(struct sk_buff *skb)
168 {
169 /* Skip PPP header, if present. In testing, Microsoft L2TP clients
170 * don't send the PPP header (PPP header compression enabled), but
171 * other clients can include the header. So we cope with both cases
172 * here. The PPP header is always FF03 when using L2TP.
173 *
174 * Note that skb->data[] isn't dereferenced from a u16 ptr here since
175 * the field may be unaligned.
176 */
177 if (!pskb_may_pull(skb, 2))
178 return 1;
179
180 if ((skb->data[0] == PPP_ALLSTATIONS) && (skb->data[1] == PPP_UI))
181 skb_pull(skb, 2);
182
183 return 0;
184 }
185
186 /* Receive message. This is the recvmsg for the PPPoL2TP socket.
187 */
188 static int pppol2tp_recvmsg(struct socket *sock, struct msghdr *msg,
189 size_t len, int flags)
190 {
191 int err;
192 struct sk_buff *skb;
193 struct sock *sk = sock->sk;
194
195 err = -EIO;
196 if (sk->sk_state & PPPOX_BOUND)
197 goto end;
198
199 err = 0;
200 skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
201 flags & MSG_DONTWAIT, &err);
202 if (!skb)
203 goto end;
204
205 if (len > skb->len)
206 len = skb->len;
207 else if (len < skb->len)
208 msg->msg_flags |= MSG_TRUNC;
209
210 err = skb_copy_datagram_msg(skb, 0, msg, len);
211 if (likely(err == 0))
212 err = len;
213
214 kfree_skb(skb);
215 end:
216 return err;
217 }
218
219 static void pppol2tp_recv(struct l2tp_session *session, struct sk_buff *skb, int data_len)
220 {
221 struct pppol2tp_session *ps = l2tp_session_priv(session);
222 struct sock *sk = NULL;
223
224 /* If the socket is bound, send it in to PPP's input queue. Otherwise
225 * queue it on the session socket.
226 */
227 sk = ps->sock;
228 if (sk == NULL)
229 goto no_sock;
230
231 if (sk->sk_state & PPPOX_BOUND) {
232 struct pppox_sock *po;
233
234 l2tp_dbg(session, L2TP_MSG_DATA,
235 "%s: recv %d byte data frame, passing to ppp\n",
236 session->name, data_len);
237
238 po = pppox_sk(sk);
239 ppp_input(&po->chan, skb);
240 } else {
241 l2tp_dbg(session, L2TP_MSG_DATA,
242 "%s: recv %d byte data frame, passing to L2TP socket\n",
243 session->name, data_len);
244
245 if (sock_queue_rcv_skb(sk, skb) < 0) {
246 atomic_long_inc(&session->stats.rx_errors);
247 kfree_skb(skb);
248 }
249 }
250
251 return;
252
253 no_sock:
254 l2tp_info(session, L2TP_MSG_DATA, "%s: no socket\n", session->name);
255 kfree_skb(skb);
256 }
257
258 static void pppol2tp_session_sock_hold(struct l2tp_session *session)
259 {
260 struct pppol2tp_session *ps = l2tp_session_priv(session);
261
262 if (ps->sock)
263 sock_hold(ps->sock);
264 }
265
266 static void pppol2tp_session_sock_put(struct l2tp_session *session)
267 {
268 struct pppol2tp_session *ps = l2tp_session_priv(session);
269
270 if (ps->sock)
271 sock_put(ps->sock);
272 }
273
274 /************************************************************************
275 * Transmit handling
276 ***********************************************************************/
277
278 /* This is the sendmsg for the PPPoL2TP pppol2tp_session socket. We come here
279 * when a user application does a sendmsg() on the session socket. L2TP and
280 * PPP headers must be inserted into the user's data.
281 */
282 static int pppol2tp_sendmsg(struct socket *sock, struct msghdr *m,
283 size_t total_len)
284 {
285 struct sock *sk = sock->sk;
286 struct sk_buff *skb;
287 int error;
288 struct l2tp_session *session;
289 struct l2tp_tunnel *tunnel;
290 struct pppol2tp_session *ps;
291 int uhlen;
292
293 error = -ENOTCONN;
294 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
295 goto error;
296
297 /* Get session and tunnel contexts */
298 error = -EBADF;
299 session = pppol2tp_sock_to_session(sk);
300 if (session == NULL)
301 goto error;
302
303 ps = l2tp_session_priv(session);
304 tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock);
305 if (tunnel == NULL)
306 goto error_put_sess;
307
308 uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0;
309
310 /* Allocate a socket buffer */
311 error = -ENOMEM;
312 skb = sock_wmalloc(sk, NET_SKB_PAD + sizeof(struct iphdr) +
313 uhlen + session->hdr_len +
314 2 + total_len, /* 2 bytes for PPP_ALLSTATIONS & PPP_UI */
315 0, GFP_KERNEL);
316 if (!skb)
317 goto error_put_sess_tun;
318
319 /* Reserve space for headers. */
320 skb_reserve(skb, NET_SKB_PAD);
321 skb_reset_network_header(skb);
322 skb_reserve(skb, sizeof(struct iphdr));
323 skb_reset_transport_header(skb);
324 skb_reserve(skb, uhlen);
325
326 /* Add PPP header */
327 skb->data[0] = PPP_ALLSTATIONS;
328 skb->data[1] = PPP_UI;
329 skb_put(skb, 2);
330
331 /* Copy user data into skb */
332 error = memcpy_from_msg(skb_put(skb, total_len), m, total_len);
333 if (error < 0) {
334 kfree_skb(skb);
335 goto error_put_sess_tun;
336 }
337
338 local_bh_disable();
339 l2tp_xmit_skb(session, skb, session->hdr_len);
340 local_bh_enable();
341
342 sock_put(ps->tunnel_sock);
343 sock_put(sk);
344
345 return total_len;
346
347 error_put_sess_tun:
348 sock_put(ps->tunnel_sock);
349 error_put_sess:
350 sock_put(sk);
351 error:
352 return error;
353 }
354
355 /* Transmit function called by generic PPP driver. Sends PPP frame
356 * over PPPoL2TP socket.
357 *
358 * This is almost the same as pppol2tp_sendmsg(), but rather than
359 * being called with a msghdr from userspace, it is called with a skb
360 * from the kernel.
361 *
362 * The supplied skb from ppp doesn't have enough headroom for the
363 * insertion of L2TP, UDP and IP headers so we need to allocate more
364 * headroom in the skb. This will create a cloned skb. But we must be
365 * careful in the error case because the caller will expect to free
366 * the skb it supplied, not our cloned skb. So we take care to always
367 * leave the original skb unfreed if we return an error.
368 */
369 static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
370 {
371 struct sock *sk = (struct sock *) chan->private;
372 struct sock *sk_tun;
373 struct l2tp_session *session;
374 struct l2tp_tunnel *tunnel;
375 struct pppol2tp_session *ps;
376 int uhlen, headroom;
377
378 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
379 goto abort;
380
381 /* Get session and tunnel contexts from the socket */
382 session = pppol2tp_sock_to_session(sk);
383 if (session == NULL)
384 goto abort;
385
386 ps = l2tp_session_priv(session);
387 sk_tun = ps->tunnel_sock;
388 if (sk_tun == NULL)
389 goto abort_put_sess;
390 tunnel = l2tp_sock_to_tunnel(sk_tun);
391 if (tunnel == NULL)
392 goto abort_put_sess;
393
394 uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0;
395 headroom = NET_SKB_PAD +
396 sizeof(struct iphdr) + /* IP header */
397 uhlen + /* UDP header (if L2TP_ENCAPTYPE_UDP) */
398 session->hdr_len + /* L2TP header */
399 2; /* 2 bytes for PPP_ALLSTATIONS & PPP_UI */
400 if (skb_cow_head(skb, headroom))
401 goto abort_put_sess_tun;
402
403 /* Setup PPP header */
404 __skb_push(skb, 2);
405 skb->data[0] = PPP_ALLSTATIONS;
406 skb->data[1] = PPP_UI;
407
408 local_bh_disable();
409 l2tp_xmit_skb(session, skb, session->hdr_len);
410 local_bh_enable();
411
412 sock_put(sk_tun);
413 sock_put(sk);
414 return 1;
415
416 abort_put_sess_tun:
417 sock_put(sk_tun);
418 abort_put_sess:
419 sock_put(sk);
420 abort:
421 /* Free the original skb */
422 kfree_skb(skb);
423 return 1;
424 }
425
426 /*****************************************************************************
427 * Session (and tunnel control) socket create/destroy.
428 *****************************************************************************/
429
430 /* Called by l2tp_core when a session socket is being closed.
431 */
432 static void pppol2tp_session_close(struct l2tp_session *session)
433 {
434 struct pppol2tp_session *ps = l2tp_session_priv(session);
435 struct sock *sk = ps->sock;
436 struct socket *sock = sk->sk_socket;
437
438 BUG_ON(session->magic != L2TP_SESSION_MAGIC);
439
440 if (sock) {
441 inet_shutdown(sock, SEND_SHUTDOWN);
442 /* Don't let the session go away before our socket does */
443 l2tp_session_inc_refcount(session);
444 }
445 }
446
447 /* Really kill the session socket. (Called from sock_put() if
448 * refcnt == 0.)
449 */
450 static void pppol2tp_session_destruct(struct sock *sk)
451 {
452 struct l2tp_session *session = sk->sk_user_data;
453
454 skb_queue_purge(&sk->sk_receive_queue);
455 skb_queue_purge(&sk->sk_write_queue);
456
457 if (session) {
458 sk->sk_user_data = NULL;
459 BUG_ON(session->magic != L2TP_SESSION_MAGIC);
460 l2tp_session_dec_refcount(session);
461 }
462 }
463
464 /* Called when the PPPoX socket (session) is closed.
465 */
466 static int pppol2tp_release(struct socket *sock)
467 {
468 struct sock *sk = sock->sk;
469 struct l2tp_session *session;
470 int error;
471
472 if (!sk)
473 return 0;
474
475 error = -EBADF;
476 lock_sock(sk);
477 if (sock_flag(sk, SOCK_DEAD) != 0)
478 goto error;
479
480 pppox_unbind_sock(sk);
481
482 /* Signal the death of the socket. */
483 sk->sk_state = PPPOX_DEAD;
484 sock_orphan(sk);
485 sock->sk = NULL;
486
487 session = pppol2tp_sock_to_session(sk);
488
489 /* Purge any queued data */
490 if (session != NULL) {
491 __l2tp_session_unhash(session);
492 l2tp_session_queue_purge(session);
493 sock_put(sk);
494 }
495 release_sock(sk);
496
497 /* This will delete the session context via
498 * pppol2tp_session_destruct() if the socket's refcnt drops to
499 * zero.
500 */
501 sock_put(sk);
502
503 return 0;
504
505 error:
506 release_sock(sk);
507 return error;
508 }
509
510 static struct proto pppol2tp_sk_proto = {
511 .name = "PPPOL2TP",
512 .owner = THIS_MODULE,
513 .obj_size = sizeof(struct pppox_sock),
514 };
515
516 static int pppol2tp_backlog_recv(struct sock *sk, struct sk_buff *skb)
517 {
518 int rc;
519
520 rc = l2tp_udp_encap_recv(sk, skb);
521 if (rc)
522 kfree_skb(skb);
523
524 return NET_RX_SUCCESS;
525 }
526
527 /* socket() handler. Initialize a new struct sock.
528 */
529 static int pppol2tp_create(struct net *net, struct socket *sock, int kern)
530 {
531 int error = -ENOMEM;
532 struct sock *sk;
533
534 sk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, &pppol2tp_sk_proto, kern);
535 if (!sk)
536 goto out;
537
538 sock_init_data(sock, sk);
539
540 sock->state = SS_UNCONNECTED;
541 sock->ops = &pppol2tp_ops;
542
543 sk->sk_backlog_rcv = pppol2tp_backlog_recv;
544 sk->sk_protocol = PX_PROTO_OL2TP;
545 sk->sk_family = PF_PPPOX;
546 sk->sk_state = PPPOX_NONE;
547 sk->sk_type = SOCK_STREAM;
548 sk->sk_destruct = pppol2tp_session_destruct;
549
550 error = 0;
551
552 out:
553 return error;
554 }
555
556 #if IS_ENABLED(CONFIG_L2TP_DEBUGFS)
557 static void pppol2tp_show(struct seq_file *m, void *arg)
558 {
559 struct l2tp_session *session = arg;
560 struct pppol2tp_session *ps = l2tp_session_priv(session);
561
562 if (ps) {
563 struct pppox_sock *po = pppox_sk(ps->sock);
564 if (po)
565 seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan));
566 }
567 }
568 #endif
569
570 /* connect() handler. Attach a PPPoX socket to a tunnel UDP socket
571 */
572 static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr,
573 int sockaddr_len, int flags)
574 {
575 struct sock *sk = sock->sk;
576 struct sockaddr_pppol2tp *sp = (struct sockaddr_pppol2tp *) uservaddr;
577 struct pppox_sock *po = pppox_sk(sk);
578 struct l2tp_session *session = NULL;
579 struct l2tp_tunnel *tunnel;
580 struct pppol2tp_session *ps;
581 struct dst_entry *dst;
582 struct l2tp_session_cfg cfg = { 0, };
583 int error = 0;
584 u32 tunnel_id, peer_tunnel_id;
585 u32 session_id, peer_session_id;
586 bool drop_refcnt = false;
587 int ver = 2;
588 int fd;
589
590 lock_sock(sk);
591
592 error = -EINVAL;
593 if (sp->sa_protocol != PX_PROTO_OL2TP)
594 goto end;
595
596 /* Check for already bound sockets */
597 error = -EBUSY;
598 if (sk->sk_state & PPPOX_CONNECTED)
599 goto end;
600
601 /* We don't supporting rebinding anyway */
602 error = -EALREADY;
603 if (sk->sk_user_data)
604 goto end; /* socket is already attached */
605
606 /* Get params from socket address. Handle L2TPv2 and L2TPv3.
607 * This is nasty because there are different sockaddr_pppol2tp
608 * structs for L2TPv2, L2TPv3, over IPv4 and IPv6. We use
609 * the sockaddr size to determine which structure the caller
610 * is using.
611 */
612 peer_tunnel_id = 0;
613 if (sockaddr_len == sizeof(struct sockaddr_pppol2tp)) {
614 fd = sp->pppol2tp.fd;
615 tunnel_id = sp->pppol2tp.s_tunnel;
616 peer_tunnel_id = sp->pppol2tp.d_tunnel;
617 session_id = sp->pppol2tp.s_session;
618 peer_session_id = sp->pppol2tp.d_session;
619 } else if (sockaddr_len == sizeof(struct sockaddr_pppol2tpv3)) {
620 struct sockaddr_pppol2tpv3 *sp3 =
621 (struct sockaddr_pppol2tpv3 *) sp;
622 ver = 3;
623 fd = sp3->pppol2tp.fd;
624 tunnel_id = sp3->pppol2tp.s_tunnel;
625 peer_tunnel_id = sp3->pppol2tp.d_tunnel;
626 session_id = sp3->pppol2tp.s_session;
627 peer_session_id = sp3->pppol2tp.d_session;
628 } else if (sockaddr_len == sizeof(struct sockaddr_pppol2tpin6)) {
629 struct sockaddr_pppol2tpin6 *sp6 =
630 (struct sockaddr_pppol2tpin6 *) sp;
631 fd = sp6->pppol2tp.fd;
632 tunnel_id = sp6->pppol2tp.s_tunnel;
633 peer_tunnel_id = sp6->pppol2tp.d_tunnel;
634 session_id = sp6->pppol2tp.s_session;
635 peer_session_id = sp6->pppol2tp.d_session;
636 } else if (sockaddr_len == sizeof(struct sockaddr_pppol2tpv3in6)) {
637 struct sockaddr_pppol2tpv3in6 *sp6 =
638 (struct sockaddr_pppol2tpv3in6 *) sp;
639 ver = 3;
640 fd = sp6->pppol2tp.fd;
641 tunnel_id = sp6->pppol2tp.s_tunnel;
642 peer_tunnel_id = sp6->pppol2tp.d_tunnel;
643 session_id = sp6->pppol2tp.s_session;
644 peer_session_id = sp6->pppol2tp.d_session;
645 } else {
646 error = -EINVAL;
647 goto end; /* bad socket address */
648 }
649
650 /* Don't bind if tunnel_id is 0 */
651 error = -EINVAL;
652 if (tunnel_id == 0)
653 goto end;
654
655 tunnel = l2tp_tunnel_find(sock_net(sk), tunnel_id);
656
657 /* Special case: create tunnel context if session_id and
658 * peer_session_id is 0. Otherwise look up tunnel using supplied
659 * tunnel id.
660 */
661 if ((session_id == 0) && (peer_session_id == 0)) {
662 if (tunnel == NULL) {
663 struct l2tp_tunnel_cfg tcfg = {
664 .encap = L2TP_ENCAPTYPE_UDP,
665 .debug = 0,
666 };
667 error = l2tp_tunnel_create(sock_net(sk), fd, ver, tunnel_id, peer_tunnel_id, &tcfg, &tunnel);
668 if (error < 0)
669 goto end;
670 }
671 } else {
672 /* Error if we can't find the tunnel */
673 error = -ENOENT;
674 if (tunnel == NULL)
675 goto end;
676
677 /* Error if socket is not prepped */
678 if (tunnel->sock == NULL)
679 goto end;
680 }
681
682 if (tunnel->recv_payload_hook == NULL)
683 tunnel->recv_payload_hook = pppol2tp_recv_payload_hook;
684
685 if (tunnel->peer_tunnel_id == 0)
686 tunnel->peer_tunnel_id = peer_tunnel_id;
687
688 session = l2tp_session_get(sock_net(sk), tunnel, session_id, false);
689 if (session) {
690 drop_refcnt = true;
691 ps = l2tp_session_priv(session);
692
693 /* Using a pre-existing session is fine as long as it hasn't
694 * been connected yet.
695 */
696 if (ps->sock) {
697 error = -EEXIST;
698 goto end;
699 }
700
701 /* consistency checks */
702 if (ps->tunnel_sock != tunnel->sock) {
703 error = -EEXIST;
704 goto end;
705 }
706 } else {
707 /* Default MTU must allow space for UDP/L2TP/PPP headers */
708 cfg.mtu = 1500 - PPPOL2TP_HEADER_OVERHEAD;
709 cfg.mru = cfg.mtu;
710
711 session = l2tp_session_create(sizeof(struct pppol2tp_session),
712 tunnel, session_id,
713 peer_session_id, &cfg);
714 if (IS_ERR(session)) {
715 error = PTR_ERR(session);
716 goto end;
717 }
718 }
719
720 /* Associate session with its PPPoL2TP socket */
721 ps = l2tp_session_priv(session);
722 ps->owner = current->pid;
723 ps->sock = sk;
724 ps->tunnel_sock = tunnel->sock;
725
726 session->recv_skb = pppol2tp_recv;
727 session->session_close = pppol2tp_session_close;
728 #if IS_ENABLED(CONFIG_L2TP_DEBUGFS)
729 session->show = pppol2tp_show;
730 #endif
731
732 /* We need to know each time a skb is dropped from the reorder
733 * queue.
734 */
735 session->ref = pppol2tp_session_sock_hold;
736 session->deref = pppol2tp_session_sock_put;
737
738 /* If PMTU discovery was enabled, use the MTU that was discovered */
739 dst = sk_dst_get(tunnel->sock);
740 if (dst != NULL) {
741 u32 pmtu = dst_mtu(dst);
742
743 if (pmtu != 0)
744 session->mtu = session->mru = pmtu -
745 PPPOL2TP_HEADER_OVERHEAD;
746 dst_release(dst);
747 }
748
749 /* Special case: if source & dest session_id == 0x0000, this
750 * socket is being created to manage the tunnel. Just set up
751 * the internal context for use by ioctl() and sockopt()
752 * handlers.
753 */
754 if ((session->session_id == 0) &&
755 (session->peer_session_id == 0)) {
756 error = 0;
757 goto out_no_ppp;
758 }
759
760 /* The only header we need to worry about is the L2TP
761 * header. This size is different depending on whether
762 * sequence numbers are enabled for the data channel.
763 */
764 po->chan.hdrlen = PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
765
766 po->chan.private = sk;
767 po->chan.ops = &pppol2tp_chan_ops;
768 po->chan.mtu = session->mtu;
769
770 error = ppp_register_net_channel(sock_net(sk), &po->chan);
771 if (error)
772 goto end;
773
774 out_no_ppp:
775 /* This is how we get the session context from the socket. */
776 sk->sk_user_data = session;
777 sk->sk_state = PPPOX_CONNECTED;
778 l2tp_info(session, L2TP_MSG_CONTROL, "%s: created\n",
779 session->name);
780
781 end:
782 if (drop_refcnt)
783 l2tp_session_dec_refcount(session);
784 release_sock(sk);
785
786 return error;
787 }
788
789 #ifdef CONFIG_L2TP_V3
790
791 /* Called when creating sessions via the netlink interface. */
792 static int pppol2tp_session_create(struct net *net, struct l2tp_tunnel *tunnel,
793 u32 session_id, u32 peer_session_id,
794 struct l2tp_session_cfg *cfg)
795 {
796 int error;
797 struct l2tp_session *session;
798 struct pppol2tp_session *ps;
799
800 /* Error if tunnel socket is not prepped */
801 if (!tunnel->sock) {
802 error = -ENOENT;
803 goto out;
804 }
805
806 /* Default MTU values. */
807 if (cfg->mtu == 0)
808 cfg->mtu = 1500 - PPPOL2TP_HEADER_OVERHEAD;
809 if (cfg->mru == 0)
810 cfg->mru = cfg->mtu;
811
812 /* Allocate and initialize a new session context. */
813 session = l2tp_session_create(sizeof(struct pppol2tp_session),
814 tunnel, session_id,
815 peer_session_id, cfg);
816 if (IS_ERR(session)) {
817 error = PTR_ERR(session);
818 goto out;
819 }
820
821 ps = l2tp_session_priv(session);
822 ps->tunnel_sock = tunnel->sock;
823
824 l2tp_info(session, L2TP_MSG_CONTROL, "%s: created\n",
825 session->name);
826
827 error = 0;
828
829 out:
830 return error;
831 }
832
833 #endif /* CONFIG_L2TP_V3 */
834
835 /* getname() support.
836 */
837 static int pppol2tp_getname(struct socket *sock, struct sockaddr *uaddr,
838 int *usockaddr_len, int peer)
839 {
840 int len = 0;
841 int error = 0;
842 struct l2tp_session *session;
843 struct l2tp_tunnel *tunnel;
844 struct sock *sk = sock->sk;
845 struct inet_sock *inet;
846 struct pppol2tp_session *pls;
847
848 error = -ENOTCONN;
849 if (sk == NULL)
850 goto end;
851 if (!(sk->sk_state & PPPOX_CONNECTED))
852 goto end;
853
854 error = -EBADF;
855 session = pppol2tp_sock_to_session(sk);
856 if (session == NULL)
857 goto end;
858
859 pls = l2tp_session_priv(session);
860 tunnel = l2tp_sock_to_tunnel(pls->tunnel_sock);
861 if (tunnel == NULL)
862 goto end_put_sess;
863
864 inet = inet_sk(tunnel->sock);
865 if ((tunnel->version == 2) && (tunnel->sock->sk_family == AF_INET)) {
866 struct sockaddr_pppol2tp sp;
867 len = sizeof(sp);
868 memset(&sp, 0, len);
869 sp.sa_family = AF_PPPOX;
870 sp.sa_protocol = PX_PROTO_OL2TP;
871 sp.pppol2tp.fd = tunnel->fd;
872 sp.pppol2tp.pid = pls->owner;
873 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
874 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
875 sp.pppol2tp.s_session = session->session_id;
876 sp.pppol2tp.d_session = session->peer_session_id;
877 sp.pppol2tp.addr.sin_family = AF_INET;
878 sp.pppol2tp.addr.sin_port = inet->inet_dport;
879 sp.pppol2tp.addr.sin_addr.s_addr = inet->inet_daddr;
880 memcpy(uaddr, &sp, len);
881 #if IS_ENABLED(CONFIG_IPV6)
882 } else if ((tunnel->version == 2) &&
883 (tunnel->sock->sk_family == AF_INET6)) {
884 struct sockaddr_pppol2tpin6 sp;
885
886 len = sizeof(sp);
887 memset(&sp, 0, len);
888 sp.sa_family = AF_PPPOX;
889 sp.sa_protocol = PX_PROTO_OL2TP;
890 sp.pppol2tp.fd = tunnel->fd;
891 sp.pppol2tp.pid = pls->owner;
892 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
893 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
894 sp.pppol2tp.s_session = session->session_id;
895 sp.pppol2tp.d_session = session->peer_session_id;
896 sp.pppol2tp.addr.sin6_family = AF_INET6;
897 sp.pppol2tp.addr.sin6_port = inet->inet_dport;
898 memcpy(&sp.pppol2tp.addr.sin6_addr, &tunnel->sock->sk_v6_daddr,
899 sizeof(tunnel->sock->sk_v6_daddr));
900 memcpy(uaddr, &sp, len);
901 } else if ((tunnel->version == 3) &&
902 (tunnel->sock->sk_family == AF_INET6)) {
903 struct sockaddr_pppol2tpv3in6 sp;
904
905 len = sizeof(sp);
906 memset(&sp, 0, len);
907 sp.sa_family = AF_PPPOX;
908 sp.sa_protocol = PX_PROTO_OL2TP;
909 sp.pppol2tp.fd = tunnel->fd;
910 sp.pppol2tp.pid = pls->owner;
911 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
912 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
913 sp.pppol2tp.s_session = session->session_id;
914 sp.pppol2tp.d_session = session->peer_session_id;
915 sp.pppol2tp.addr.sin6_family = AF_INET6;
916 sp.pppol2tp.addr.sin6_port = inet->inet_dport;
917 memcpy(&sp.pppol2tp.addr.sin6_addr, &tunnel->sock->sk_v6_daddr,
918 sizeof(tunnel->sock->sk_v6_daddr));
919 memcpy(uaddr, &sp, len);
920 #endif
921 } else if (tunnel->version == 3) {
922 struct sockaddr_pppol2tpv3 sp;
923 len = sizeof(sp);
924 memset(&sp, 0, len);
925 sp.sa_family = AF_PPPOX;
926 sp.sa_protocol = PX_PROTO_OL2TP;
927 sp.pppol2tp.fd = tunnel->fd;
928 sp.pppol2tp.pid = pls->owner;
929 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
930 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
931 sp.pppol2tp.s_session = session->session_id;
932 sp.pppol2tp.d_session = session->peer_session_id;
933 sp.pppol2tp.addr.sin_family = AF_INET;
934 sp.pppol2tp.addr.sin_port = inet->inet_dport;
935 sp.pppol2tp.addr.sin_addr.s_addr = inet->inet_daddr;
936 memcpy(uaddr, &sp, len);
937 }
938
939 *usockaddr_len = len;
940 error = 0;
941
942 sock_put(pls->tunnel_sock);
943 end_put_sess:
944 sock_put(sk);
945 end:
946 return error;
947 }
948
949 /****************************************************************************
950 * ioctl() handlers.
951 *
952 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
953 * sockets. However, in order to control kernel tunnel features, we allow
954 * userspace to create a special "tunnel" PPPoX socket which is used for
955 * control only. Tunnel PPPoX sockets have session_id == 0 and simply allow
956 * the user application to issue L2TP setsockopt(), getsockopt() and ioctl()
957 * calls.
958 ****************************************************************************/
959
960 static void pppol2tp_copy_stats(struct pppol2tp_ioc_stats *dest,
961 struct l2tp_stats *stats)
962 {
963 dest->tx_packets = atomic_long_read(&stats->tx_packets);
964 dest->tx_bytes = atomic_long_read(&stats->tx_bytes);
965 dest->tx_errors = atomic_long_read(&stats->tx_errors);
966 dest->rx_packets = atomic_long_read(&stats->rx_packets);
967 dest->rx_bytes = atomic_long_read(&stats->rx_bytes);
968 dest->rx_seq_discards = atomic_long_read(&stats->rx_seq_discards);
969 dest->rx_oos_packets = atomic_long_read(&stats->rx_oos_packets);
970 dest->rx_errors = atomic_long_read(&stats->rx_errors);
971 }
972
973 /* Session ioctl helper.
974 */
975 static int pppol2tp_session_ioctl(struct l2tp_session *session,
976 unsigned int cmd, unsigned long arg)
977 {
978 struct ifreq ifr;
979 int err = 0;
980 struct sock *sk;
981 int val = (int) arg;
982 struct pppol2tp_session *ps = l2tp_session_priv(session);
983 struct l2tp_tunnel *tunnel = session->tunnel;
984 struct pppol2tp_ioc_stats stats;
985
986 l2tp_dbg(session, L2TP_MSG_CONTROL,
987 "%s: pppol2tp_session_ioctl(cmd=%#x, arg=%#lx)\n",
988 session->name, cmd, arg);
989
990 sk = ps->sock;
991 sock_hold(sk);
992
993 switch (cmd) {
994 case SIOCGIFMTU:
995 err = -ENXIO;
996 if (!(sk->sk_state & PPPOX_CONNECTED))
997 break;
998
999 err = -EFAULT;
1000 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq)))
1001 break;
1002 ifr.ifr_mtu = session->mtu;
1003 if (copy_to_user((void __user *) arg, &ifr, sizeof(struct ifreq)))
1004 break;
1005
1006 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get mtu=%d\n",
1007 session->name, session->mtu);
1008 err = 0;
1009 break;
1010
1011 case SIOCSIFMTU:
1012 err = -ENXIO;
1013 if (!(sk->sk_state & PPPOX_CONNECTED))
1014 break;
1015
1016 err = -EFAULT;
1017 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq)))
1018 break;
1019
1020 session->mtu = ifr.ifr_mtu;
1021
1022 l2tp_info(session, L2TP_MSG_CONTROL, "%s: set mtu=%d\n",
1023 session->name, session->mtu);
1024 err = 0;
1025 break;
1026
1027 case PPPIOCGMRU:
1028 err = -ENXIO;
1029 if (!(sk->sk_state & PPPOX_CONNECTED))
1030 break;
1031
1032 err = -EFAULT;
1033 if (put_user(session->mru, (int __user *) arg))
1034 break;
1035
1036 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get mru=%d\n",
1037 session->name, session->mru);
1038 err = 0;
1039 break;
1040
1041 case PPPIOCSMRU:
1042 err = -ENXIO;
1043 if (!(sk->sk_state & PPPOX_CONNECTED))
1044 break;
1045
1046 err = -EFAULT;
1047 if (get_user(val, (int __user *) arg))
1048 break;
1049
1050 session->mru = val;
1051 l2tp_info(session, L2TP_MSG_CONTROL, "%s: set mru=%d\n",
1052 session->name, session->mru);
1053 err = 0;
1054 break;
1055
1056 case PPPIOCGFLAGS:
1057 err = -EFAULT;
1058 if (put_user(ps->flags, (int __user *) arg))
1059 break;
1060
1061 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get flags=%d\n",
1062 session->name, ps->flags);
1063 err = 0;
1064 break;
1065
1066 case PPPIOCSFLAGS:
1067 err = -EFAULT;
1068 if (get_user(val, (int __user *) arg))
1069 break;
1070 ps->flags = val;
1071 l2tp_info(session, L2TP_MSG_CONTROL, "%s: set flags=%d\n",
1072 session->name, ps->flags);
1073 err = 0;
1074 break;
1075
1076 case PPPIOCGL2TPSTATS:
1077 err = -ENXIO;
1078 if (!(sk->sk_state & PPPOX_CONNECTED))
1079 break;
1080
1081 memset(&stats, 0, sizeof(stats));
1082 stats.tunnel_id = tunnel->tunnel_id;
1083 stats.session_id = session->session_id;
1084 pppol2tp_copy_stats(&stats, &session->stats);
1085 if (copy_to_user((void __user *) arg, &stats,
1086 sizeof(stats)))
1087 break;
1088 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get L2TP stats\n",
1089 session->name);
1090 err = 0;
1091 break;
1092
1093 default:
1094 err = -ENOSYS;
1095 break;
1096 }
1097
1098 sock_put(sk);
1099
1100 return err;
1101 }
1102
1103 /* Tunnel ioctl helper.
1104 *
1105 * Note the special handling for PPPIOCGL2TPSTATS below. If the ioctl data
1106 * specifies a session_id, the session ioctl handler is called. This allows an
1107 * application to retrieve session stats via a tunnel socket.
1108 */
1109 static int pppol2tp_tunnel_ioctl(struct l2tp_tunnel *tunnel,
1110 unsigned int cmd, unsigned long arg)
1111 {
1112 int err = 0;
1113 struct sock *sk;
1114 struct pppol2tp_ioc_stats stats;
1115
1116 l2tp_dbg(tunnel, L2TP_MSG_CONTROL,
1117 "%s: pppol2tp_tunnel_ioctl(cmd=%#x, arg=%#lx)\n",
1118 tunnel->name, cmd, arg);
1119
1120 sk = tunnel->sock;
1121 sock_hold(sk);
1122
1123 switch (cmd) {
1124 case PPPIOCGL2TPSTATS:
1125 err = -ENXIO;
1126 if (!(sk->sk_state & PPPOX_CONNECTED))
1127 break;
1128
1129 if (copy_from_user(&stats, (void __user *) arg,
1130 sizeof(stats))) {
1131 err = -EFAULT;
1132 break;
1133 }
1134 if (stats.session_id != 0) {
1135 /* resend to session ioctl handler */
1136 struct l2tp_session *session =
1137 l2tp_session_get(sock_net(sk), tunnel,
1138 stats.session_id, true);
1139
1140 if (session) {
1141 err = pppol2tp_session_ioctl(session, cmd,
1142 arg);
1143 if (session->deref)
1144 session->deref(session);
1145 l2tp_session_dec_refcount(session);
1146 } else {
1147 err = -EBADR;
1148 }
1149 break;
1150 }
1151 #ifdef CONFIG_XFRM
1152 stats.using_ipsec = (sk->sk_policy[0] || sk->sk_policy[1]) ? 1 : 0;
1153 #endif
1154 pppol2tp_copy_stats(&stats, &tunnel->stats);
1155 if (copy_to_user((void __user *) arg, &stats, sizeof(stats))) {
1156 err = -EFAULT;
1157 break;
1158 }
1159 l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: get L2TP stats\n",
1160 tunnel->name);
1161 err = 0;
1162 break;
1163
1164 default:
1165 err = -ENOSYS;
1166 break;
1167 }
1168
1169 sock_put(sk);
1170
1171 return err;
1172 }
1173
1174 /* Main ioctl() handler.
1175 * Dispatch to tunnel or session helpers depending on the socket.
1176 */
1177 static int pppol2tp_ioctl(struct socket *sock, unsigned int cmd,
1178 unsigned long arg)
1179 {
1180 struct sock *sk = sock->sk;
1181 struct l2tp_session *session;
1182 struct l2tp_tunnel *tunnel;
1183 struct pppol2tp_session *ps;
1184 int err;
1185
1186 if (!sk)
1187 return 0;
1188
1189 err = -EBADF;
1190 if (sock_flag(sk, SOCK_DEAD) != 0)
1191 goto end;
1192
1193 err = -ENOTCONN;
1194 if ((sk->sk_user_data == NULL) ||
1195 (!(sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND))))
1196 goto end;
1197
1198 /* Get session context from the socket */
1199 err = -EBADF;
1200 session = pppol2tp_sock_to_session(sk);
1201 if (session == NULL)
1202 goto end;
1203
1204 /* Special case: if session's session_id is zero, treat ioctl as a
1205 * tunnel ioctl
1206 */
1207 ps = l2tp_session_priv(session);
1208 if ((session->session_id == 0) &&
1209 (session->peer_session_id == 0)) {
1210 err = -EBADF;
1211 tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock);
1212 if (tunnel == NULL)
1213 goto end_put_sess;
1214
1215 err = pppol2tp_tunnel_ioctl(tunnel, cmd, arg);
1216 sock_put(ps->tunnel_sock);
1217 goto end_put_sess;
1218 }
1219
1220 err = pppol2tp_session_ioctl(session, cmd, arg);
1221
1222 end_put_sess:
1223 sock_put(sk);
1224 end:
1225 return err;
1226 }
1227
1228 /*****************************************************************************
1229 * setsockopt() / getsockopt() support.
1230 *
1231 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
1232 * sockets. In order to control kernel tunnel features, we allow userspace to
1233 * create a special "tunnel" PPPoX socket which is used for control only.
1234 * Tunnel PPPoX sockets have session_id == 0 and simply allow the user
1235 * application to issue L2TP setsockopt(), getsockopt() and ioctl() calls.
1236 *****************************************************************************/
1237
1238 /* Tunnel setsockopt() helper.
1239 */
1240 static int pppol2tp_tunnel_setsockopt(struct sock *sk,
1241 struct l2tp_tunnel *tunnel,
1242 int optname, int val)
1243 {
1244 int err = 0;
1245
1246 switch (optname) {
1247 case PPPOL2TP_SO_DEBUG:
1248 tunnel->debug = val;
1249 l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: set debug=%x\n",
1250 tunnel->name, tunnel->debug);
1251 break;
1252
1253 default:
1254 err = -ENOPROTOOPT;
1255 break;
1256 }
1257
1258 return err;
1259 }
1260
1261 /* Session setsockopt helper.
1262 */
1263 static int pppol2tp_session_setsockopt(struct sock *sk,
1264 struct l2tp_session *session,
1265 int optname, int val)
1266 {
1267 int err = 0;
1268 struct pppol2tp_session *ps = l2tp_session_priv(session);
1269
1270 switch (optname) {
1271 case PPPOL2TP_SO_RECVSEQ:
1272 if ((val != 0) && (val != 1)) {
1273 err = -EINVAL;
1274 break;
1275 }
1276 session->recv_seq = !!val;
1277 l2tp_info(session, L2TP_MSG_CONTROL,
1278 "%s: set recv_seq=%d\n",
1279 session->name, session->recv_seq);
1280 break;
1281
1282 case PPPOL2TP_SO_SENDSEQ:
1283 if ((val != 0) && (val != 1)) {
1284 err = -EINVAL;
1285 break;
1286 }
1287 session->send_seq = !!val;
1288 {
1289 struct sock *ssk = ps->sock;
1290 struct pppox_sock *po = pppox_sk(ssk);
1291 po->chan.hdrlen = val ? PPPOL2TP_L2TP_HDR_SIZE_SEQ :
1292 PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
1293 }
1294 l2tp_session_set_header_len(session, session->tunnel->version);
1295 l2tp_info(session, L2TP_MSG_CONTROL,
1296 "%s: set send_seq=%d\n",
1297 session->name, session->send_seq);
1298 break;
1299
1300 case PPPOL2TP_SO_LNSMODE:
1301 if ((val != 0) && (val != 1)) {
1302 err = -EINVAL;
1303 break;
1304 }
1305 session->lns_mode = !!val;
1306 l2tp_info(session, L2TP_MSG_CONTROL,
1307 "%s: set lns_mode=%d\n",
1308 session->name, session->lns_mode);
1309 break;
1310
1311 case PPPOL2TP_SO_DEBUG:
1312 session->debug = val;
1313 l2tp_info(session, L2TP_MSG_CONTROL, "%s: set debug=%x\n",
1314 session->name, session->debug);
1315 break;
1316
1317 case PPPOL2TP_SO_REORDERTO:
1318 session->reorder_timeout = msecs_to_jiffies(val);
1319 l2tp_info(session, L2TP_MSG_CONTROL,
1320 "%s: set reorder_timeout=%d\n",
1321 session->name, session->reorder_timeout);
1322 break;
1323
1324 default:
1325 err = -ENOPROTOOPT;
1326 break;
1327 }
1328
1329 return err;
1330 }
1331
1332 /* Main setsockopt() entry point.
1333 * Does API checks, then calls either the tunnel or session setsockopt
1334 * handler, according to whether the PPPoL2TP socket is a for a regular
1335 * session or the special tunnel type.
1336 */
1337 static int pppol2tp_setsockopt(struct socket *sock, int level, int optname,
1338 char __user *optval, unsigned int optlen)
1339 {
1340 struct sock *sk = sock->sk;
1341 struct l2tp_session *session;
1342 struct l2tp_tunnel *tunnel;
1343 struct pppol2tp_session *ps;
1344 int val;
1345 int err;
1346
1347 if (level != SOL_PPPOL2TP)
1348 return -EINVAL;
1349
1350 if (optlen < sizeof(int))
1351 return -EINVAL;
1352
1353 if (get_user(val, (int __user *)optval))
1354 return -EFAULT;
1355
1356 err = -ENOTCONN;
1357 if (sk->sk_user_data == NULL)
1358 goto end;
1359
1360 /* Get session context from the socket */
1361 err = -EBADF;
1362 session = pppol2tp_sock_to_session(sk);
1363 if (session == NULL)
1364 goto end;
1365
1366 /* Special case: if session_id == 0x0000, treat as operation on tunnel
1367 */
1368 ps = l2tp_session_priv(session);
1369 if ((session->session_id == 0) &&
1370 (session->peer_session_id == 0)) {
1371 err = -EBADF;
1372 tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock);
1373 if (tunnel == NULL)
1374 goto end_put_sess;
1375
1376 err = pppol2tp_tunnel_setsockopt(sk, tunnel, optname, val);
1377 sock_put(ps->tunnel_sock);
1378 } else
1379 err = pppol2tp_session_setsockopt(sk, session, optname, val);
1380
1381 end_put_sess:
1382 sock_put(sk);
1383 end:
1384 return err;
1385 }
1386
1387 /* Tunnel getsockopt helper. Called with sock locked.
1388 */
1389 static int pppol2tp_tunnel_getsockopt(struct sock *sk,
1390 struct l2tp_tunnel *tunnel,
1391 int optname, int *val)
1392 {
1393 int err = 0;
1394
1395 switch (optname) {
1396 case PPPOL2TP_SO_DEBUG:
1397 *val = tunnel->debug;
1398 l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: get debug=%x\n",
1399 tunnel->name, tunnel->debug);
1400 break;
1401
1402 default:
1403 err = -ENOPROTOOPT;
1404 break;
1405 }
1406
1407 return err;
1408 }
1409
1410 /* Session getsockopt helper. Called with sock locked.
1411 */
1412 static int pppol2tp_session_getsockopt(struct sock *sk,
1413 struct l2tp_session *session,
1414 int optname, int *val)
1415 {
1416 int err = 0;
1417
1418 switch (optname) {
1419 case PPPOL2TP_SO_RECVSEQ:
1420 *val = session->recv_seq;
1421 l2tp_info(session, L2TP_MSG_CONTROL,
1422 "%s: get recv_seq=%d\n", session->name, *val);
1423 break;
1424
1425 case PPPOL2TP_SO_SENDSEQ:
1426 *val = session->send_seq;
1427 l2tp_info(session, L2TP_MSG_CONTROL,
1428 "%s: get send_seq=%d\n", session->name, *val);
1429 break;
1430
1431 case PPPOL2TP_SO_LNSMODE:
1432 *val = session->lns_mode;
1433 l2tp_info(session, L2TP_MSG_CONTROL,
1434 "%s: get lns_mode=%d\n", session->name, *val);
1435 break;
1436
1437 case PPPOL2TP_SO_DEBUG:
1438 *val = session->debug;
1439 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get debug=%d\n",
1440 session->name, *val);
1441 break;
1442
1443 case PPPOL2TP_SO_REORDERTO:
1444 *val = (int) jiffies_to_msecs(session->reorder_timeout);
1445 l2tp_info(session, L2TP_MSG_CONTROL,
1446 "%s: get reorder_timeout=%d\n", session->name, *val);
1447 break;
1448
1449 default:
1450 err = -ENOPROTOOPT;
1451 }
1452
1453 return err;
1454 }
1455
1456 /* Main getsockopt() entry point.
1457 * Does API checks, then calls either the tunnel or session getsockopt
1458 * handler, according to whether the PPPoX socket is a for a regular session
1459 * or the special tunnel type.
1460 */
1461 static int pppol2tp_getsockopt(struct socket *sock, int level, int optname,
1462 char __user *optval, int __user *optlen)
1463 {
1464 struct sock *sk = sock->sk;
1465 struct l2tp_session *session;
1466 struct l2tp_tunnel *tunnel;
1467 int val, len;
1468 int err;
1469 struct pppol2tp_session *ps;
1470
1471 if (level != SOL_PPPOL2TP)
1472 return -EINVAL;
1473
1474 if (get_user(len, optlen))
1475 return -EFAULT;
1476
1477 len = min_t(unsigned int, len, sizeof(int));
1478
1479 if (len < 0)
1480 return -EINVAL;
1481
1482 err = -ENOTCONN;
1483 if (sk->sk_user_data == NULL)
1484 goto end;
1485
1486 /* Get the session context */
1487 err = -EBADF;
1488 session = pppol2tp_sock_to_session(sk);
1489 if (session == NULL)
1490 goto end;
1491
1492 /* Special case: if session_id == 0x0000, treat as operation on tunnel */
1493 ps = l2tp_session_priv(session);
1494 if ((session->session_id == 0) &&
1495 (session->peer_session_id == 0)) {
1496 err = -EBADF;
1497 tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock);
1498 if (tunnel == NULL)
1499 goto end_put_sess;
1500
1501 err = pppol2tp_tunnel_getsockopt(sk, tunnel, optname, &val);
1502 sock_put(ps->tunnel_sock);
1503 if (err)
1504 goto end_put_sess;
1505 } else {
1506 err = pppol2tp_session_getsockopt(sk, session, optname, &val);
1507 if (err)
1508 goto end_put_sess;
1509 }
1510
1511 err = -EFAULT;
1512 if (put_user(len, optlen))
1513 goto end_put_sess;
1514
1515 if (copy_to_user((void __user *) optval, &val, len))
1516 goto end_put_sess;
1517
1518 err = 0;
1519
1520 end_put_sess:
1521 sock_put(sk);
1522 end:
1523 return err;
1524 }
1525
1526 /*****************************************************************************
1527 * /proc filesystem for debug
1528 * Since the original pppol2tp driver provided /proc/net/pppol2tp for
1529 * L2TPv2, we dump only L2TPv2 tunnels and sessions here.
1530 *****************************************************************************/
1531
1532 static unsigned int pppol2tp_net_id;
1533
1534 #ifdef CONFIG_PROC_FS
1535
1536 struct pppol2tp_seq_data {
1537 struct seq_net_private p;
1538 int tunnel_idx; /* current tunnel */
1539 int session_idx; /* index of session within current tunnel */
1540 struct l2tp_tunnel *tunnel;
1541 struct l2tp_session *session; /* NULL means get next tunnel */
1542 };
1543
1544 static void pppol2tp_next_tunnel(struct net *net, struct pppol2tp_seq_data *pd)
1545 {
1546 for (;;) {
1547 pd->tunnel = l2tp_tunnel_find_nth(net, pd->tunnel_idx);
1548 pd->tunnel_idx++;
1549
1550 if (pd->tunnel == NULL)
1551 break;
1552
1553 /* Ignore L2TPv3 tunnels */
1554 if (pd->tunnel->version < 3)
1555 break;
1556 }
1557 }
1558
1559 static void pppol2tp_next_session(struct net *net, struct pppol2tp_seq_data *pd)
1560 {
1561 pd->session = l2tp_session_get_nth(pd->tunnel, pd->session_idx, true);
1562 pd->session_idx++;
1563
1564 if (pd->session == NULL) {
1565 pd->session_idx = 0;
1566 pppol2tp_next_tunnel(net, pd);
1567 }
1568 }
1569
1570 static void *pppol2tp_seq_start(struct seq_file *m, loff_t *offs)
1571 {
1572 struct pppol2tp_seq_data *pd = SEQ_START_TOKEN;
1573 loff_t pos = *offs;
1574 struct net *net;
1575
1576 if (!pos)
1577 goto out;
1578
1579 BUG_ON(m->private == NULL);
1580 pd = m->private;
1581 net = seq_file_net(m);
1582
1583 if (pd->tunnel == NULL)
1584 pppol2tp_next_tunnel(net, pd);
1585 else
1586 pppol2tp_next_session(net, pd);
1587
1588 /* NULL tunnel and session indicates end of list */
1589 if ((pd->tunnel == NULL) && (pd->session == NULL))
1590 pd = NULL;
1591
1592 out:
1593 return pd;
1594 }
1595
1596 static void *pppol2tp_seq_next(struct seq_file *m, void *v, loff_t *pos)
1597 {
1598 (*pos)++;
1599 return NULL;
1600 }
1601
1602 static void pppol2tp_seq_stop(struct seq_file *p, void *v)
1603 {
1604 /* nothing to do */
1605 }
1606
1607 static void pppol2tp_seq_tunnel_show(struct seq_file *m, void *v)
1608 {
1609 struct l2tp_tunnel *tunnel = v;
1610
1611 seq_printf(m, "\nTUNNEL '%s', %c %d\n",
1612 tunnel->name,
1613 (tunnel == tunnel->sock->sk_user_data) ? 'Y' : 'N',
1614 refcount_read(&tunnel->ref_count) - 1);
1615 seq_printf(m, " %08x %ld/%ld/%ld %ld/%ld/%ld\n",
1616 tunnel->debug,
1617 atomic_long_read(&tunnel->stats.tx_packets),
1618 atomic_long_read(&tunnel->stats.tx_bytes),
1619 atomic_long_read(&tunnel->stats.tx_errors),
1620 atomic_long_read(&tunnel->stats.rx_packets),
1621 atomic_long_read(&tunnel->stats.rx_bytes),
1622 atomic_long_read(&tunnel->stats.rx_errors));
1623 }
1624
1625 static void pppol2tp_seq_session_show(struct seq_file *m, void *v)
1626 {
1627 struct l2tp_session *session = v;
1628 struct l2tp_tunnel *tunnel = session->tunnel;
1629 struct pppol2tp_session *ps = l2tp_session_priv(session);
1630 struct pppox_sock *po = pppox_sk(ps->sock);
1631 u32 ip = 0;
1632 u16 port = 0;
1633
1634 if (tunnel->sock) {
1635 struct inet_sock *inet = inet_sk(tunnel->sock);
1636 ip = ntohl(inet->inet_saddr);
1637 port = ntohs(inet->inet_sport);
1638 }
1639
1640 seq_printf(m, " SESSION '%s' %08X/%d %04X/%04X -> "
1641 "%04X/%04X %d %c\n",
1642 session->name, ip, port,
1643 tunnel->tunnel_id,
1644 session->session_id,
1645 tunnel->peer_tunnel_id,
1646 session->peer_session_id,
1647 ps->sock->sk_state,
1648 (session == ps->sock->sk_user_data) ?
1649 'Y' : 'N');
1650 seq_printf(m, " %d/%d/%c/%c/%s %08x %u\n",
1651 session->mtu, session->mru,
1652 session->recv_seq ? 'R' : '-',
1653 session->send_seq ? 'S' : '-',
1654 session->lns_mode ? "LNS" : "LAC",
1655 session->debug,
1656 jiffies_to_msecs(session->reorder_timeout));
1657 seq_printf(m, " %hu/%hu %ld/%ld/%ld %ld/%ld/%ld\n",
1658 session->nr, session->ns,
1659 atomic_long_read(&session->stats.tx_packets),
1660 atomic_long_read(&session->stats.tx_bytes),
1661 atomic_long_read(&session->stats.tx_errors),
1662 atomic_long_read(&session->stats.rx_packets),
1663 atomic_long_read(&session->stats.rx_bytes),
1664 atomic_long_read(&session->stats.rx_errors));
1665
1666 if (po)
1667 seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan));
1668 }
1669
1670 static int pppol2tp_seq_show(struct seq_file *m, void *v)
1671 {
1672 struct pppol2tp_seq_data *pd = v;
1673
1674 /* display header on line 1 */
1675 if (v == SEQ_START_TOKEN) {
1676 seq_puts(m, "PPPoL2TP driver info, " PPPOL2TP_DRV_VERSION "\n");
1677 seq_puts(m, "TUNNEL name, user-data-ok session-count\n");
1678 seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
1679 seq_puts(m, " SESSION name, addr/port src-tid/sid "
1680 "dest-tid/sid state user-data-ok\n");
1681 seq_puts(m, " mtu/mru/rcvseq/sendseq/lns debug reorderto\n");
1682 seq_puts(m, " nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
1683 goto out;
1684 }
1685
1686 /* Show the tunnel or session context.
1687 */
1688 if (!pd->session) {
1689 pppol2tp_seq_tunnel_show(m, pd->tunnel);
1690 } else {
1691 pppol2tp_seq_session_show(m, pd->session);
1692 if (pd->session->deref)
1693 pd->session->deref(pd->session);
1694 l2tp_session_dec_refcount(pd->session);
1695 }
1696
1697 out:
1698 return 0;
1699 }
1700
1701 static const struct seq_operations pppol2tp_seq_ops = {
1702 .start = pppol2tp_seq_start,
1703 .next = pppol2tp_seq_next,
1704 .stop = pppol2tp_seq_stop,
1705 .show = pppol2tp_seq_show,
1706 };
1707
1708 /* Called when our /proc file is opened. We allocate data for use when
1709 * iterating our tunnel / session contexts and store it in the private
1710 * data of the seq_file.
1711 */
1712 static int pppol2tp_proc_open(struct inode *inode, struct file *file)
1713 {
1714 return seq_open_net(inode, file, &pppol2tp_seq_ops,
1715 sizeof(struct pppol2tp_seq_data));
1716 }
1717
1718 static const struct file_operations pppol2tp_proc_fops = {
1719 .owner = THIS_MODULE,
1720 .open = pppol2tp_proc_open,
1721 .read = seq_read,
1722 .llseek = seq_lseek,
1723 .release = seq_release_net,
1724 };
1725
1726 #endif /* CONFIG_PROC_FS */
1727
1728 /*****************************************************************************
1729 * Network namespace
1730 *****************************************************************************/
1731
1732 static __net_init int pppol2tp_init_net(struct net *net)
1733 {
1734 struct proc_dir_entry *pde;
1735 int err = 0;
1736
1737 pde = proc_create("pppol2tp", S_IRUGO, net->proc_net,
1738 &pppol2tp_proc_fops);
1739 if (!pde) {
1740 err = -ENOMEM;
1741 goto out;
1742 }
1743
1744 out:
1745 return err;
1746 }
1747
1748 static __net_exit void pppol2tp_exit_net(struct net *net)
1749 {
1750 remove_proc_entry("pppol2tp", net->proc_net);
1751 }
1752
1753 static struct pernet_operations pppol2tp_net_ops = {
1754 .init = pppol2tp_init_net,
1755 .exit = pppol2tp_exit_net,
1756 .id = &pppol2tp_net_id,
1757 };
1758
1759 /*****************************************************************************
1760 * Init and cleanup
1761 *****************************************************************************/
1762
1763 static const struct proto_ops pppol2tp_ops = {
1764 .family = AF_PPPOX,
1765 .owner = THIS_MODULE,
1766 .release = pppol2tp_release,
1767 .bind = sock_no_bind,
1768 .connect = pppol2tp_connect,
1769 .socketpair = sock_no_socketpair,
1770 .accept = sock_no_accept,
1771 .getname = pppol2tp_getname,
1772 .poll = datagram_poll,
1773 .listen = sock_no_listen,
1774 .shutdown = sock_no_shutdown,
1775 .setsockopt = pppol2tp_setsockopt,
1776 .getsockopt = pppol2tp_getsockopt,
1777 .sendmsg = pppol2tp_sendmsg,
1778 .recvmsg = pppol2tp_recvmsg,
1779 .mmap = sock_no_mmap,
1780 .ioctl = pppox_ioctl,
1781 };
1782
1783 static const struct pppox_proto pppol2tp_proto = {
1784 .create = pppol2tp_create,
1785 .ioctl = pppol2tp_ioctl,
1786 .owner = THIS_MODULE,
1787 };
1788
1789 #ifdef CONFIG_L2TP_V3
1790
1791 static const struct l2tp_nl_cmd_ops pppol2tp_nl_cmd_ops = {
1792 .session_create = pppol2tp_session_create,
1793 .session_delete = l2tp_session_delete,
1794 };
1795
1796 #endif /* CONFIG_L2TP_V3 */
1797
1798 static int __init pppol2tp_init(void)
1799 {
1800 int err;
1801
1802 err = register_pernet_device(&pppol2tp_net_ops);
1803 if (err)
1804 goto out;
1805
1806 err = proto_register(&pppol2tp_sk_proto, 0);
1807 if (err)
1808 goto out_unregister_pppol2tp_pernet;
1809
1810 err = register_pppox_proto(PX_PROTO_OL2TP, &pppol2tp_proto);
1811 if (err)
1812 goto out_unregister_pppol2tp_proto;
1813
1814 #ifdef CONFIG_L2TP_V3
1815 err = l2tp_nl_register_ops(L2TP_PWTYPE_PPP, &pppol2tp_nl_cmd_ops);
1816 if (err)
1817 goto out_unregister_pppox;
1818 #endif
1819
1820 pr_info("PPPoL2TP kernel driver, %s\n", PPPOL2TP_DRV_VERSION);
1821
1822 out:
1823 return err;
1824
1825 #ifdef CONFIG_L2TP_V3
1826 out_unregister_pppox:
1827 unregister_pppox_proto(PX_PROTO_OL2TP);
1828 #endif
1829 out_unregister_pppol2tp_proto:
1830 proto_unregister(&pppol2tp_sk_proto);
1831 out_unregister_pppol2tp_pernet:
1832 unregister_pernet_device(&pppol2tp_net_ops);
1833 goto out;
1834 }
1835
1836 static void __exit pppol2tp_exit(void)
1837 {
1838 #ifdef CONFIG_L2TP_V3
1839 l2tp_nl_unregister_ops(L2TP_PWTYPE_PPP);
1840 #endif
1841 unregister_pppox_proto(PX_PROTO_OL2TP);
1842 proto_unregister(&pppol2tp_sk_proto);
1843 unregister_pernet_device(&pppol2tp_net_ops);
1844 }
1845
1846 module_init(pppol2tp_init);
1847 module_exit(pppol2tp_exit);
1848
1849 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
1850 MODULE_DESCRIPTION("PPP over L2TP over UDP");
1851 MODULE_LICENSE("GPL");
1852 MODULE_VERSION(PPPOL2TP_DRV_VERSION);
1853 MODULE_ALIAS_NET_PF_PROTO(PF_PPPOX, PX_PROTO_OL2TP);
1854 MODULE_ALIAS_L2TP_PWTYPE(7);
Linux with added FPC-III support