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new helper: memcpy_from_msg()
[deliverable/linux.git] / net / l2tp / l2tp_ppp.c
1 /*****************************************************************************
2 * Linux PPP over L2TP (PPPoX/PPPoL2TP) Sockets
3 *
4 * PPPoX --- Generic PPP encapsulation socket family
5 * PPPoL2TP --- PPP over L2TP (RFC 2661)
6 *
7 * Version: 2.0.0
8 *
9 * Authors: James Chapman (jchapman@katalix.com)
10 *
11 * Based on original work by Martijn van Oosterhout <kleptog@svana.org>
12 *
13 * License:
14 * This program is free software; you can redistribute it and/or
15 * modify it under the terms of the GNU General Public License
16 * as published by the Free Software Foundation; either version
17 * 2 of the License, or (at your option) any later version.
18 *
19 */
20
21 /* This driver handles only L2TP data frames; control frames are handled by a
22 * userspace application.
23 *
24 * To send data in an L2TP session, userspace opens a PPPoL2TP socket and
25 * attaches it to a bound UDP socket with local tunnel_id / session_id and
26 * peer tunnel_id / session_id set. Data can then be sent or received using
27 * regular socket sendmsg() / recvmsg() calls. Kernel parameters of the socket
28 * can be read or modified using ioctl() or [gs]etsockopt() calls.
29 *
30 * When a PPPoL2TP socket is connected with local and peer session_id values
31 * zero, the socket is treated as a special tunnel management socket.
32 *
33 * Here's example userspace code to create a socket for sending/receiving data
34 * over an L2TP session:-
35 *
36 * struct sockaddr_pppol2tp sax;
37 * int fd;
38 * int session_fd;
39 *
40 * fd = socket(AF_PPPOX, SOCK_DGRAM, PX_PROTO_OL2TP);
41 *
42 * sax.sa_family = AF_PPPOX;
43 * sax.sa_protocol = PX_PROTO_OL2TP;
44 * sax.pppol2tp.fd = tunnel_fd; // bound UDP socket
45 * sax.pppol2tp.addr.sin_addr.s_addr = addr->sin_addr.s_addr;
46 * sax.pppol2tp.addr.sin_port = addr->sin_port;
47 * sax.pppol2tp.addr.sin_family = AF_INET;
48 * sax.pppol2tp.s_tunnel = tunnel_id;
49 * sax.pppol2tp.s_session = session_id;
50 * sax.pppol2tp.d_tunnel = peer_tunnel_id;
51 * sax.pppol2tp.d_session = peer_session_id;
52 *
53 * session_fd = connect(fd, (struct sockaddr *)&sax, sizeof(sax));
54 *
55 * A pppd plugin that allows PPP traffic to be carried over L2TP using
56 * this driver is available from the OpenL2TP project at
57 * http://openl2tp.sourceforge.net.
58 */
59
60 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
61
62 #include <linux/module.h>
63 #include <linux/string.h>
64 #include <linux/list.h>
65 #include <linux/uaccess.h>
66
67 #include <linux/kernel.h>
68 #include <linux/spinlock.h>
69 #include <linux/kthread.h>
70 #include <linux/sched.h>
71 #include <linux/slab.h>
72 #include <linux/errno.h>
73 #include <linux/jiffies.h>
74
75 #include <linux/netdevice.h>
76 #include <linux/net.h>
77 #include <linux/inetdevice.h>
78 #include <linux/skbuff.h>
79 #include <linux/init.h>
80 #include <linux/ip.h>
81 #include <linux/udp.h>
82 #include <linux/if_pppox.h>
83 #include <linux/if_pppol2tp.h>
84 #include <net/sock.h>
85 #include <linux/ppp_channel.h>
86 #include <linux/ppp_defs.h>
87 #include <linux/ppp-ioctl.h>
88 #include <linux/file.h>
89 #include <linux/hash.h>
90 #include <linux/sort.h>
91 #include <linux/proc_fs.h>
92 #include <linux/l2tp.h>
93 #include <linux/nsproxy.h>
94 #include <net/net_namespace.h>
95 #include <net/netns/generic.h>
96 #include <net/dst.h>
97 #include <net/ip.h>
98 #include <net/udp.h>
99 #include <net/xfrm.h>
100 #include <net/inet_common.h>
101
102 #include <asm/byteorder.h>
103 #include <linux/atomic.h>
104
105 #include "l2tp_core.h"
106
107 #define PPPOL2TP_DRV_VERSION "V2.0"
108
109 /* Space for UDP, L2TP and PPP headers */
110 #define PPPOL2TP_HEADER_OVERHEAD 40
111
112 /* Number of bytes to build transmit L2TP headers.
113 * Unfortunately the size is different depending on whether sequence numbers
114 * are enabled.
115 */
116 #define PPPOL2TP_L2TP_HDR_SIZE_SEQ 10
117 #define PPPOL2TP_L2TP_HDR_SIZE_NOSEQ 6
118
119 /* Private data of each session. This data lives at the end of struct
120 * l2tp_session, referenced via session->priv[].
121 */
122 struct pppol2tp_session {
123 int owner; /* pid that opened the socket */
124
125 struct sock *sock; /* Pointer to the session
126 * PPPoX socket */
127 struct sock *tunnel_sock; /* Pointer to the tunnel UDP
128 * socket */
129 int flags; /* accessed by PPPIOCGFLAGS.
130 * Unused. */
131 };
132
133 static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb);
134
135 static const struct ppp_channel_ops pppol2tp_chan_ops = {
136 .start_xmit = pppol2tp_xmit,
137 };
138
139 static const struct proto_ops pppol2tp_ops;
140
141 /* Helpers to obtain tunnel/session contexts from sockets.
142 */
143 static inline struct l2tp_session *pppol2tp_sock_to_session(struct sock *sk)
144 {
145 struct l2tp_session *session;
146
147 if (sk == NULL)
148 return NULL;
149
150 sock_hold(sk);
151 session = (struct l2tp_session *)(sk->sk_user_data);
152 if (session == NULL) {
153 sock_put(sk);
154 goto out;
155 }
156
157 BUG_ON(session->magic != L2TP_SESSION_MAGIC);
158
159 out:
160 return session;
161 }
162
163 /*****************************************************************************
164 * Receive data handling
165 *****************************************************************************/
166
167 static int pppol2tp_recv_payload_hook(struct sk_buff *skb)
168 {
169 /* Skip PPP header, if present. In testing, Microsoft L2TP clients
170 * don't send the PPP header (PPP header compression enabled), but
171 * other clients can include the header. So we cope with both cases
172 * here. The PPP header is always FF03 when using L2TP.
173 *
174 * Note that skb->data[] isn't dereferenced from a u16 ptr here since
175 * the field may be unaligned.
176 */
177 if (!pskb_may_pull(skb, 2))
178 return 1;
179
180 if ((skb->data[0] == 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 kiocb *iocb, struct socket *sock,
189 struct msghdr *msg, size_t len,
190 int flags)
191 {
192 int err;
193 struct sk_buff *skb;
194 struct sock *sk = sock->sk;
195
196 err = -EIO;
197 if (sk->sk_state & PPPOX_BOUND)
198 goto end;
199
200 err = 0;
201 skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
202 flags & MSG_DONTWAIT, &err);
203 if (!skb)
204 goto end;
205
206 if (len > skb->len)
207 len = skb->len;
208 else if (len < skb->len)
209 msg->msg_flags |= MSG_TRUNC;
210
211 err = skb_copy_datagram_msg(skb, 0, msg, len);
212 if (likely(err == 0))
213 err = len;
214
215 kfree_skb(skb);
216 end:
217 return err;
218 }
219
220 static void pppol2tp_recv(struct l2tp_session *session, struct sk_buff *skb, int data_len)
221 {
222 struct pppol2tp_session *ps = l2tp_session_priv(session);
223 struct sock *sk = NULL;
224
225 /* If the socket is bound, send it in to PPP's input queue. Otherwise
226 * queue it on the session socket.
227 */
228 sk = ps->sock;
229 if (sk == NULL)
230 goto no_sock;
231
232 if (sk->sk_state & PPPOX_BOUND) {
233 struct pppox_sock *po;
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 /* We need to forget all info related to the L2TP packet
239 * gathered in the skb as we are going to reuse the same
240 * skb for the inner packet.
241 * Namely we need to:
242 * - reset xfrm (IPSec) information as it applies to
243 * the outer L2TP packet and not to the inner one
244 * - release the dst to force a route lookup on the inner
245 * IP packet since skb->dst currently points to the dst
246 * of the UDP tunnel
247 * - reset netfilter information as it doesn't apply
248 * to the inner packet either
249 */
250 secpath_reset(skb);
251 skb_dst_drop(skb);
252 nf_reset(skb);
253
254 po = pppox_sk(sk);
255 ppp_input(&po->chan, skb);
256 } else {
257 l2tp_dbg(session, PPPOL2TP_MSG_DATA,
258 "%s: recv %d byte data frame, passing to L2TP socket\n",
259 session->name, data_len);
260
261 if (sock_queue_rcv_skb(sk, skb) < 0) {
262 atomic_long_inc(&session->stats.rx_errors);
263 kfree_skb(skb);
264 }
265 }
266
267 return;
268
269 no_sock:
270 l2tp_info(session, PPPOL2TP_MSG_DATA, "%s: no socket\n", session->name);
271 kfree_skb(skb);
272 }
273
274 static void pppol2tp_session_sock_hold(struct l2tp_session *session)
275 {
276 struct pppol2tp_session *ps = l2tp_session_priv(session);
277
278 if (ps->sock)
279 sock_hold(ps->sock);
280 }
281
282 static void pppol2tp_session_sock_put(struct l2tp_session *session)
283 {
284 struct pppol2tp_session *ps = l2tp_session_priv(session);
285
286 if (ps->sock)
287 sock_put(ps->sock);
288 }
289
290 /************************************************************************
291 * Transmit handling
292 ***********************************************************************/
293
294 /* This is the sendmsg for the PPPoL2TP pppol2tp_session socket. We come here
295 * when a user application does a sendmsg() on the session socket. L2TP and
296 * PPP headers must be inserted into the user's data.
297 */
298 static int pppol2tp_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
299 size_t total_len)
300 {
301 static const unsigned char ppph[2] = { 0xff, 0x03 };
302 struct sock *sk = sock->sk;
303 struct sk_buff *skb;
304 int error;
305 struct l2tp_session *session;
306 struct l2tp_tunnel *tunnel;
307 struct pppol2tp_session *ps;
308 int uhlen;
309
310 error = -ENOTCONN;
311 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
312 goto error;
313
314 /* Get session and tunnel contexts */
315 error = -EBADF;
316 session = pppol2tp_sock_to_session(sk);
317 if (session == NULL)
318 goto error;
319
320 ps = l2tp_session_priv(session);
321 tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock);
322 if (tunnel == NULL)
323 goto error_put_sess;
324
325 uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0;
326
327 /* Allocate a socket buffer */
328 error = -ENOMEM;
329 skb = sock_wmalloc(sk, NET_SKB_PAD + sizeof(struct iphdr) +
330 uhlen + session->hdr_len +
331 sizeof(ppph) + total_len,
332 0, GFP_KERNEL);
333 if (!skb)
334 goto error_put_sess_tun;
335
336 /* Reserve space for headers. */
337 skb_reserve(skb, NET_SKB_PAD);
338 skb_reset_network_header(skb);
339 skb_reserve(skb, sizeof(struct iphdr));
340 skb_reset_transport_header(skb);
341 skb_reserve(skb, uhlen);
342
343 /* Add PPP header */
344 skb->data[0] = ppph[0];
345 skb->data[1] = ppph[1];
346 skb_put(skb, 2);
347
348 /* Copy user data into skb */
349 error = memcpy_from_msg(skb_put(skb, total_len), m, total_len);
350 if (error < 0) {
351 kfree_skb(skb);
352 goto error_put_sess_tun;
353 }
354
355 local_bh_disable();
356 l2tp_xmit_skb(session, skb, session->hdr_len);
357 local_bh_enable();
358
359 sock_put(ps->tunnel_sock);
360 sock_put(sk);
361
362 return total_len;
363
364 error_put_sess_tun:
365 sock_put(ps->tunnel_sock);
366 error_put_sess:
367 sock_put(sk);
368 error:
369 return error;
370 }
371
372 /* Transmit function called by generic PPP driver. Sends PPP frame
373 * over PPPoL2TP socket.
374 *
375 * This is almost the same as pppol2tp_sendmsg(), but rather than
376 * being called with a msghdr from userspace, it is called with a skb
377 * from the kernel.
378 *
379 * The supplied skb from ppp doesn't have enough headroom for the
380 * insertion of L2TP, UDP and IP headers so we need to allocate more
381 * headroom in the skb. This will create a cloned skb. But we must be
382 * careful in the error case because the caller will expect to free
383 * the skb it supplied, not our cloned skb. So we take care to always
384 * leave the original skb unfreed if we return an error.
385 */
386 static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
387 {
388 static const u8 ppph[2] = { 0xff, 0x03 };
389 struct sock *sk = (struct sock *) chan->private;
390 struct sock *sk_tun;
391 struct l2tp_session *session;
392 struct l2tp_tunnel *tunnel;
393 struct pppol2tp_session *ps;
394 int uhlen, headroom;
395
396 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
397 goto abort;
398
399 /* Get session and tunnel contexts from the socket */
400 session = pppol2tp_sock_to_session(sk);
401 if (session == NULL)
402 goto abort;
403
404 ps = l2tp_session_priv(session);
405 sk_tun = ps->tunnel_sock;
406 if (sk_tun == NULL)
407 goto abort_put_sess;
408 tunnel = l2tp_sock_to_tunnel(sk_tun);
409 if (tunnel == NULL)
410 goto abort_put_sess;
411
412 uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0;
413 headroom = NET_SKB_PAD +
414 sizeof(struct iphdr) + /* IP header */
415 uhlen + /* UDP header (if L2TP_ENCAPTYPE_UDP) */
416 session->hdr_len + /* L2TP header */
417 sizeof(ppph); /* PPP header */
418 if (skb_cow_head(skb, headroom))
419 goto abort_put_sess_tun;
420
421 /* Setup PPP header */
422 __skb_push(skb, sizeof(ppph));
423 skb->data[0] = ppph[0];
424 skb->data[1] = ppph[1];
425
426 local_bh_disable();
427 l2tp_xmit_skb(session, skb, session->hdr_len);
428 local_bh_enable();
429
430 sock_put(sk_tun);
431 sock_put(sk);
432 return 1;
433
434 abort_put_sess_tun:
435 sock_put(sk_tun);
436 abort_put_sess:
437 sock_put(sk);
438 abort:
439 /* Free the original skb */
440 kfree_skb(skb);
441 return 1;
442 }
443
444 /*****************************************************************************
445 * Session (and tunnel control) socket create/destroy.
446 *****************************************************************************/
447
448 /* Called by l2tp_core when a session socket is being closed.
449 */
450 static void pppol2tp_session_close(struct l2tp_session *session)
451 {
452 struct pppol2tp_session *ps = l2tp_session_priv(session);
453 struct sock *sk = ps->sock;
454 struct socket *sock = sk->sk_socket;
455
456 BUG_ON(session->magic != L2TP_SESSION_MAGIC);
457
458 if (sock) {
459 inet_shutdown(sock, 2);
460 /* Don't let the session go away before our socket does */
461 l2tp_session_inc_refcount(session);
462 }
463 }
464
465 /* Really kill the session socket. (Called from sock_put() if
466 * refcnt == 0.)
467 */
468 static void pppol2tp_session_destruct(struct sock *sk)
469 {
470 struct l2tp_session *session = sk->sk_user_data;
471 if (session) {
472 sk->sk_user_data = NULL;
473 BUG_ON(session->magic != L2TP_SESSION_MAGIC);
474 l2tp_session_dec_refcount(session);
475 }
476 }
477
478 /* Called when the PPPoX socket (session) is closed.
479 */
480 static int pppol2tp_release(struct socket *sock)
481 {
482 struct sock *sk = sock->sk;
483 struct l2tp_session *session;
484 int error;
485
486 if (!sk)
487 return 0;
488
489 error = -EBADF;
490 lock_sock(sk);
491 if (sock_flag(sk, SOCK_DEAD) != 0)
492 goto error;
493
494 pppox_unbind_sock(sk);
495
496 /* Signal the death of the socket. */
497 sk->sk_state = PPPOX_DEAD;
498 sock_orphan(sk);
499 sock->sk = NULL;
500
501 session = pppol2tp_sock_to_session(sk);
502
503 /* Purge any queued data */
504 if (session != NULL) {
505 __l2tp_session_unhash(session);
506 l2tp_session_queue_purge(session);
507 sock_put(sk);
508 }
509 skb_queue_purge(&sk->sk_receive_queue);
510 skb_queue_purge(&sk->sk_write_queue);
511
512 release_sock(sk);
513
514 /* This will delete the session context via
515 * pppol2tp_session_destruct() if the socket's refcnt drops to
516 * zero.
517 */
518 sock_put(sk);
519
520 return 0;
521
522 error:
523 release_sock(sk);
524 return error;
525 }
526
527 static struct proto pppol2tp_sk_proto = {
528 .name = "PPPOL2TP",
529 .owner = THIS_MODULE,
530 .obj_size = sizeof(struct pppox_sock),
531 };
532
533 static int pppol2tp_backlog_recv(struct sock *sk, struct sk_buff *skb)
534 {
535 int rc;
536
537 rc = l2tp_udp_encap_recv(sk, skb);
538 if (rc)
539 kfree_skb(skb);
540
541 return NET_RX_SUCCESS;
542 }
543
544 /* socket() handler. Initialize a new struct sock.
545 */
546 static int pppol2tp_create(struct net *net, struct socket *sock)
547 {
548 int error = -ENOMEM;
549 struct sock *sk;
550
551 sk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, &pppol2tp_sk_proto);
552 if (!sk)
553 goto out;
554
555 sock_init_data(sock, sk);
556
557 sock->state = SS_UNCONNECTED;
558 sock->ops = &pppol2tp_ops;
559
560 sk->sk_backlog_rcv = pppol2tp_backlog_recv;
561 sk->sk_protocol = PX_PROTO_OL2TP;
562 sk->sk_family = PF_PPPOX;
563 sk->sk_state = PPPOX_NONE;
564 sk->sk_type = SOCK_STREAM;
565 sk->sk_destruct = pppol2tp_session_destruct;
566
567 error = 0;
568
569 out:
570 return error;
571 }
572
573 #if defined(CONFIG_L2TP_DEBUGFS) || defined(CONFIG_L2TP_DEBUGFS_MODULE)
574 static void pppol2tp_show(struct seq_file *m, void *arg)
575 {
576 struct l2tp_session *session = arg;
577 struct pppol2tp_session *ps = l2tp_session_priv(session);
578
579 if (ps) {
580 struct pppox_sock *po = pppox_sk(ps->sock);
581 if (po)
582 seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan));
583 }
584 }
585 #endif
586
587 /* connect() handler. Attach a PPPoX socket to a tunnel UDP socket
588 */
589 static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr,
590 int sockaddr_len, int flags)
591 {
592 struct sock *sk = sock->sk;
593 struct sockaddr_pppol2tp *sp = (struct sockaddr_pppol2tp *) uservaddr;
594 struct pppox_sock *po = pppox_sk(sk);
595 struct l2tp_session *session = NULL;
596 struct l2tp_tunnel *tunnel;
597 struct pppol2tp_session *ps;
598 struct dst_entry *dst;
599 struct l2tp_session_cfg cfg = { 0, };
600 int error = 0;
601 u32 tunnel_id, peer_tunnel_id;
602 u32 session_id, peer_session_id;
603 int ver = 2;
604 int fd;
605
606 lock_sock(sk);
607
608 error = -EINVAL;
609 if (sp->sa_protocol != PX_PROTO_OL2TP)
610 goto end;
611
612 /* Check for already bound sockets */
613 error = -EBUSY;
614 if (sk->sk_state & PPPOX_CONNECTED)
615 goto end;
616
617 /* We don't supporting rebinding anyway */
618 error = -EALREADY;
619 if (sk->sk_user_data)
620 goto end; /* socket is already attached */
621
622 /* Get params from socket address. Handle L2TPv2 and L2TPv3.
623 * This is nasty because there are different sockaddr_pppol2tp
624 * structs for L2TPv2, L2TPv3, over IPv4 and IPv6. We use
625 * the sockaddr size to determine which structure the caller
626 * is using.
627 */
628 peer_tunnel_id = 0;
629 if (sockaddr_len == sizeof(struct sockaddr_pppol2tp)) {
630 fd = sp->pppol2tp.fd;
631 tunnel_id = sp->pppol2tp.s_tunnel;
632 peer_tunnel_id = sp->pppol2tp.d_tunnel;
633 session_id = sp->pppol2tp.s_session;
634 peer_session_id = sp->pppol2tp.d_session;
635 } else if (sockaddr_len == sizeof(struct sockaddr_pppol2tpv3)) {
636 struct sockaddr_pppol2tpv3 *sp3 =
637 (struct sockaddr_pppol2tpv3 *) sp;
638 ver = 3;
639 fd = sp3->pppol2tp.fd;
640 tunnel_id = sp3->pppol2tp.s_tunnel;
641 peer_tunnel_id = sp3->pppol2tp.d_tunnel;
642 session_id = sp3->pppol2tp.s_session;
643 peer_session_id = sp3->pppol2tp.d_session;
644 } else if (sockaddr_len == sizeof(struct sockaddr_pppol2tpin6)) {
645 struct sockaddr_pppol2tpin6 *sp6 =
646 (struct sockaddr_pppol2tpin6 *) sp;
647 fd = sp6->pppol2tp.fd;
648 tunnel_id = sp6->pppol2tp.s_tunnel;
649 peer_tunnel_id = sp6->pppol2tp.d_tunnel;
650 session_id = sp6->pppol2tp.s_session;
651 peer_session_id = sp6->pppol2tp.d_session;
652 } else if (sockaddr_len == sizeof(struct sockaddr_pppol2tpv3in6)) {
653 struct sockaddr_pppol2tpv3in6 *sp6 =
654 (struct sockaddr_pppol2tpv3in6 *) sp;
655 ver = 3;
656 fd = sp6->pppol2tp.fd;
657 tunnel_id = sp6->pppol2tp.s_tunnel;
658 peer_tunnel_id = sp6->pppol2tp.d_tunnel;
659 session_id = sp6->pppol2tp.s_session;
660 peer_session_id = sp6->pppol2tp.d_session;
661 } else {
662 error = -EINVAL;
663 goto end; /* bad socket address */
664 }
665
666 /* Don't bind if tunnel_id is 0 */
667 error = -EINVAL;
668 if (tunnel_id == 0)
669 goto end;
670
671 tunnel = l2tp_tunnel_find(sock_net(sk), tunnel_id);
672
673 /* Special case: create tunnel context if session_id and
674 * peer_session_id is 0. Otherwise look up tunnel using supplied
675 * tunnel id.
676 */
677 if ((session_id == 0) && (peer_session_id == 0)) {
678 if (tunnel == NULL) {
679 struct l2tp_tunnel_cfg tcfg = {
680 .encap = L2TP_ENCAPTYPE_UDP,
681 .debug = 0,
682 };
683 error = l2tp_tunnel_create(sock_net(sk), fd, ver, tunnel_id, peer_tunnel_id, &tcfg, &tunnel);
684 if (error < 0)
685 goto end;
686 }
687 } else {
688 /* Error if we can't find the tunnel */
689 error = -ENOENT;
690 if (tunnel == NULL)
691 goto end;
692
693 /* Error if socket is not prepped */
694 if (tunnel->sock == NULL)
695 goto end;
696 }
697
698 if (tunnel->recv_payload_hook == NULL)
699 tunnel->recv_payload_hook = pppol2tp_recv_payload_hook;
700
701 if (tunnel->peer_tunnel_id == 0)
702 tunnel->peer_tunnel_id = peer_tunnel_id;
703
704 /* Create session if it doesn't already exist. We handle the
705 * case where a session was previously created by the netlink
706 * interface by checking that the session doesn't already have
707 * a socket and its tunnel socket are what we expect. If any
708 * of those checks fail, return EEXIST to the caller.
709 */
710 session = l2tp_session_find(sock_net(sk), tunnel, session_id);
711 if (session == NULL) {
712 /* Default MTU must allow space for UDP/L2TP/PPP
713 * headers.
714 */
715 cfg.mtu = cfg.mru = 1500 - PPPOL2TP_HEADER_OVERHEAD;
716
717 /* Allocate and initialize a new session context. */
718 session = l2tp_session_create(sizeof(struct pppol2tp_session),
719 tunnel, session_id,
720 peer_session_id, &cfg);
721 if (session == NULL) {
722 error = -ENOMEM;
723 goto end;
724 }
725 } else {
726 ps = l2tp_session_priv(session);
727 error = -EEXIST;
728 if (ps->sock != NULL)
729 goto end;
730
731 /* consistency checks */
732 if (ps->tunnel_sock != tunnel->sock)
733 goto end;
734 }
735
736 /* Associate session with its PPPoL2TP socket */
737 ps = l2tp_session_priv(session);
738 ps->owner = current->pid;
739 ps->sock = sk;
740 ps->tunnel_sock = tunnel->sock;
741
742 session->recv_skb = pppol2tp_recv;
743 session->session_close = pppol2tp_session_close;
744 #if defined(CONFIG_L2TP_DEBUGFS) || defined(CONFIG_L2TP_DEBUGFS_MODULE)
745 session->show = pppol2tp_show;
746 #endif
747
748 /* We need to know each time a skb is dropped from the reorder
749 * queue.
750 */
751 session->ref = pppol2tp_session_sock_hold;
752 session->deref = pppol2tp_session_sock_put;
753
754 /* If PMTU discovery was enabled, use the MTU that was discovered */
755 dst = sk_dst_get(tunnel->sock);
756 if (dst != NULL) {
757 u32 pmtu = dst_mtu(dst);
758
759 if (pmtu != 0)
760 session->mtu = session->mru = pmtu -
761 PPPOL2TP_HEADER_OVERHEAD;
762 dst_release(dst);
763 }
764
765 /* Special case: if source & dest session_id == 0x0000, this
766 * socket is being created to manage the tunnel. Just set up
767 * the internal context for use by ioctl() and sockopt()
768 * handlers.
769 */
770 if ((session->session_id == 0) &&
771 (session->peer_session_id == 0)) {
772 error = 0;
773 goto out_no_ppp;
774 }
775
776 /* The only header we need to worry about is the L2TP
777 * header. This size is different depending on whether
778 * sequence numbers are enabled for the data channel.
779 */
780 po->chan.hdrlen = PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
781
782 po->chan.private = sk;
783 po->chan.ops = &pppol2tp_chan_ops;
784 po->chan.mtu = session->mtu;
785
786 error = ppp_register_net_channel(sock_net(sk), &po->chan);
787 if (error)
788 goto end;
789
790 out_no_ppp:
791 /* This is how we get the session context from the socket. */
792 sk->sk_user_data = session;
793 sk->sk_state = PPPOX_CONNECTED;
794 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: created\n",
795 session->name);
796
797 end:
798 release_sock(sk);
799
800 return error;
801 }
802
803 #ifdef CONFIG_L2TP_V3
804
805 /* Called when creating sessions via the netlink interface.
806 */
807 static int pppol2tp_session_create(struct net *net, u32 tunnel_id, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg)
808 {
809 int error;
810 struct l2tp_tunnel *tunnel;
811 struct l2tp_session *session;
812 struct pppol2tp_session *ps;
813
814 tunnel = l2tp_tunnel_find(net, tunnel_id);
815
816 /* Error if we can't find the tunnel */
817 error = -ENOENT;
818 if (tunnel == NULL)
819 goto out;
820
821 /* Error if tunnel socket is not prepped */
822 if (tunnel->sock == NULL)
823 goto out;
824
825 /* Check that this session doesn't already exist */
826 error = -EEXIST;
827 session = l2tp_session_find(net, tunnel, session_id);
828 if (session != NULL)
829 goto out;
830
831 /* Default MTU values. */
832 if (cfg->mtu == 0)
833 cfg->mtu = 1500 - PPPOL2TP_HEADER_OVERHEAD;
834 if (cfg->mru == 0)
835 cfg->mru = cfg->mtu;
836
837 /* Allocate and initialize a new session context. */
838 error = -ENOMEM;
839 session = l2tp_session_create(sizeof(struct pppol2tp_session),
840 tunnel, session_id,
841 peer_session_id, cfg);
842 if (session == NULL)
843 goto out;
844
845 ps = l2tp_session_priv(session);
846 ps->tunnel_sock = tunnel->sock;
847
848 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: created\n",
849 session->name);
850
851 error = 0;
852
853 out:
854 return error;
855 }
856
857 #endif /* CONFIG_L2TP_V3 */
858
859 /* getname() support.
860 */
861 static int pppol2tp_getname(struct socket *sock, struct sockaddr *uaddr,
862 int *usockaddr_len, int peer)
863 {
864 int len = 0;
865 int error = 0;
866 struct l2tp_session *session;
867 struct l2tp_tunnel *tunnel;
868 struct sock *sk = sock->sk;
869 struct inet_sock *inet;
870 struct pppol2tp_session *pls;
871
872 error = -ENOTCONN;
873 if (sk == NULL)
874 goto end;
875 if (sk->sk_state != PPPOX_CONNECTED)
876 goto end;
877
878 error = -EBADF;
879 session = pppol2tp_sock_to_session(sk);
880 if (session == NULL)
881 goto end;
882
883 pls = l2tp_session_priv(session);
884 tunnel = l2tp_sock_to_tunnel(pls->tunnel_sock);
885 if (tunnel == NULL) {
886 error = -EBADF;
887 goto end_put_sess;
888 }
889
890 inet = inet_sk(tunnel->sock);
891 if ((tunnel->version == 2) && (tunnel->sock->sk_family == AF_INET)) {
892 struct sockaddr_pppol2tp sp;
893 len = sizeof(sp);
894 memset(&sp, 0, len);
895 sp.sa_family = AF_PPPOX;
896 sp.sa_protocol = PX_PROTO_OL2TP;
897 sp.pppol2tp.fd = tunnel->fd;
898 sp.pppol2tp.pid = pls->owner;
899 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
900 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
901 sp.pppol2tp.s_session = session->session_id;
902 sp.pppol2tp.d_session = session->peer_session_id;
903 sp.pppol2tp.addr.sin_family = AF_INET;
904 sp.pppol2tp.addr.sin_port = inet->inet_dport;
905 sp.pppol2tp.addr.sin_addr.s_addr = inet->inet_daddr;
906 memcpy(uaddr, &sp, len);
907 #if IS_ENABLED(CONFIG_IPV6)
908 } else if ((tunnel->version == 2) &&
909 (tunnel->sock->sk_family == AF_INET6)) {
910 struct sockaddr_pppol2tpin6 sp;
911
912 len = sizeof(sp);
913 memset(&sp, 0, len);
914 sp.sa_family = AF_PPPOX;
915 sp.sa_protocol = PX_PROTO_OL2TP;
916 sp.pppol2tp.fd = tunnel->fd;
917 sp.pppol2tp.pid = pls->owner;
918 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
919 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
920 sp.pppol2tp.s_session = session->session_id;
921 sp.pppol2tp.d_session = session->peer_session_id;
922 sp.pppol2tp.addr.sin6_family = AF_INET6;
923 sp.pppol2tp.addr.sin6_port = inet->inet_dport;
924 memcpy(&sp.pppol2tp.addr.sin6_addr, &tunnel->sock->sk_v6_daddr,
925 sizeof(tunnel->sock->sk_v6_daddr));
926 memcpy(uaddr, &sp, len);
927 } else if ((tunnel->version == 3) &&
928 (tunnel->sock->sk_family == AF_INET6)) {
929 struct sockaddr_pppol2tpv3in6 sp;
930
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.sin6_family = AF_INET6;
942 sp.pppol2tp.addr.sin6_port = inet->inet_dport;
943 memcpy(&sp.pppol2tp.addr.sin6_addr, &tunnel->sock->sk_v6_daddr,
944 sizeof(tunnel->sock->sk_v6_daddr));
945 memcpy(uaddr, &sp, len);
946 #endif
947 } else if (tunnel->version == 3) {
948 struct sockaddr_pppol2tpv3 sp;
949 len = sizeof(sp);
950 memset(&sp, 0, len);
951 sp.sa_family = AF_PPPOX;
952 sp.sa_protocol = PX_PROTO_OL2TP;
953 sp.pppol2tp.fd = tunnel->fd;
954 sp.pppol2tp.pid = pls->owner;
955 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
956 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
957 sp.pppol2tp.s_session = session->session_id;
958 sp.pppol2tp.d_session = session->peer_session_id;
959 sp.pppol2tp.addr.sin_family = AF_INET;
960 sp.pppol2tp.addr.sin_port = inet->inet_dport;
961 sp.pppol2tp.addr.sin_addr.s_addr = inet->inet_daddr;
962 memcpy(uaddr, &sp, len);
963 }
964
965 *usockaddr_len = len;
966
967 sock_put(pls->tunnel_sock);
968 end_put_sess:
969 sock_put(sk);
970 error = 0;
971
972 end:
973 return error;
974 }
975
976 /****************************************************************************
977 * ioctl() handlers.
978 *
979 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
980 * sockets. However, in order to control kernel tunnel features, we allow
981 * userspace to create a special "tunnel" PPPoX socket which is used for
982 * control only. Tunnel PPPoX sockets have session_id == 0 and simply allow
983 * the user application to issue L2TP setsockopt(), getsockopt() and ioctl()
984 * calls.
985 ****************************************************************************/
986
987 static void pppol2tp_copy_stats(struct pppol2tp_ioc_stats *dest,
988 struct l2tp_stats *stats)
989 {
990 dest->tx_packets = atomic_long_read(&stats->tx_packets);
991 dest->tx_bytes = atomic_long_read(&stats->tx_bytes);
992 dest->tx_errors = atomic_long_read(&stats->tx_errors);
993 dest->rx_packets = atomic_long_read(&stats->rx_packets);
994 dest->rx_bytes = atomic_long_read(&stats->rx_bytes);
995 dest->rx_seq_discards = atomic_long_read(&stats->rx_seq_discards);
996 dest->rx_oos_packets = atomic_long_read(&stats->rx_oos_packets);
997 dest->rx_errors = atomic_long_read(&stats->rx_errors);
998 }
999
1000 /* Session ioctl helper.
1001 */
1002 static int pppol2tp_session_ioctl(struct l2tp_session *session,
1003 unsigned int cmd, unsigned long arg)
1004 {
1005 struct ifreq ifr;
1006 int err = 0;
1007 struct sock *sk;
1008 int val = (int) arg;
1009 struct pppol2tp_session *ps = l2tp_session_priv(session);
1010 struct l2tp_tunnel *tunnel = session->tunnel;
1011 struct pppol2tp_ioc_stats stats;
1012
1013 l2tp_dbg(session, PPPOL2TP_MSG_CONTROL,
1014 "%s: pppol2tp_session_ioctl(cmd=%#x, arg=%#lx)\n",
1015 session->name, cmd, arg);
1016
1017 sk = ps->sock;
1018 sock_hold(sk);
1019
1020 switch (cmd) {
1021 case SIOCGIFMTU:
1022 err = -ENXIO;
1023 if (!(sk->sk_state & PPPOX_CONNECTED))
1024 break;
1025
1026 err = -EFAULT;
1027 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq)))
1028 break;
1029 ifr.ifr_mtu = session->mtu;
1030 if (copy_to_user((void __user *) arg, &ifr, sizeof(struct ifreq)))
1031 break;
1032
1033 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: get mtu=%d\n",
1034 session->name, session->mtu);
1035 err = 0;
1036 break;
1037
1038 case SIOCSIFMTU:
1039 err = -ENXIO;
1040 if (!(sk->sk_state & PPPOX_CONNECTED))
1041 break;
1042
1043 err = -EFAULT;
1044 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq)))
1045 break;
1046
1047 session->mtu = ifr.ifr_mtu;
1048
1049 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: set mtu=%d\n",
1050 session->name, session->mtu);
1051 err = 0;
1052 break;
1053
1054 case PPPIOCGMRU:
1055 err = -ENXIO;
1056 if (!(sk->sk_state & PPPOX_CONNECTED))
1057 break;
1058
1059 err = -EFAULT;
1060 if (put_user(session->mru, (int __user *) arg))
1061 break;
1062
1063 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: get mru=%d\n",
1064 session->name, session->mru);
1065 err = 0;
1066 break;
1067
1068 case PPPIOCSMRU:
1069 err = -ENXIO;
1070 if (!(sk->sk_state & PPPOX_CONNECTED))
1071 break;
1072
1073 err = -EFAULT;
1074 if (get_user(val, (int __user *) arg))
1075 break;
1076
1077 session->mru = val;
1078 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: set mru=%d\n",
1079 session->name, session->mru);
1080 err = 0;
1081 break;
1082
1083 case PPPIOCGFLAGS:
1084 err = -EFAULT;
1085 if (put_user(ps->flags, (int __user *) arg))
1086 break;
1087
1088 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: get flags=%d\n",
1089 session->name, ps->flags);
1090 err = 0;
1091 break;
1092
1093 case PPPIOCSFLAGS:
1094 err = -EFAULT;
1095 if (get_user(val, (int __user *) arg))
1096 break;
1097 ps->flags = val;
1098 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: set flags=%d\n",
1099 session->name, ps->flags);
1100 err = 0;
1101 break;
1102
1103 case PPPIOCGL2TPSTATS:
1104 err = -ENXIO;
1105 if (!(sk->sk_state & PPPOX_CONNECTED))
1106 break;
1107
1108 memset(&stats, 0, sizeof(stats));
1109 stats.tunnel_id = tunnel->tunnel_id;
1110 stats.session_id = session->session_id;
1111 pppol2tp_copy_stats(&stats, &session->stats);
1112 if (copy_to_user((void __user *) arg, &stats,
1113 sizeof(stats)))
1114 break;
1115 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: get L2TP stats\n",
1116 session->name);
1117 err = 0;
1118 break;
1119
1120 default:
1121 err = -ENOSYS;
1122 break;
1123 }
1124
1125 sock_put(sk);
1126
1127 return err;
1128 }
1129
1130 /* Tunnel ioctl helper.
1131 *
1132 * Note the special handling for PPPIOCGL2TPSTATS below. If the ioctl data
1133 * specifies a session_id, the session ioctl handler is called. This allows an
1134 * application to retrieve session stats via a tunnel socket.
1135 */
1136 static int pppol2tp_tunnel_ioctl(struct l2tp_tunnel *tunnel,
1137 unsigned int cmd, unsigned long arg)
1138 {
1139 int err = 0;
1140 struct sock *sk;
1141 struct pppol2tp_ioc_stats stats;
1142
1143 l2tp_dbg(tunnel, PPPOL2TP_MSG_CONTROL,
1144 "%s: pppol2tp_tunnel_ioctl(cmd=%#x, arg=%#lx)\n",
1145 tunnel->name, cmd, arg);
1146
1147 sk = tunnel->sock;
1148 sock_hold(sk);
1149
1150 switch (cmd) {
1151 case PPPIOCGL2TPSTATS:
1152 err = -ENXIO;
1153 if (!(sk->sk_state & PPPOX_CONNECTED))
1154 break;
1155
1156 if (copy_from_user(&stats, (void __user *) arg,
1157 sizeof(stats))) {
1158 err = -EFAULT;
1159 break;
1160 }
1161 if (stats.session_id != 0) {
1162 /* resend to session ioctl handler */
1163 struct l2tp_session *session =
1164 l2tp_session_find(sock_net(sk), tunnel, stats.session_id);
1165 if (session != NULL)
1166 err = pppol2tp_session_ioctl(session, cmd, arg);
1167 else
1168 err = -EBADR;
1169 break;
1170 }
1171 #ifdef CONFIG_XFRM
1172 stats.using_ipsec = (sk->sk_policy[0] || sk->sk_policy[1]) ? 1 : 0;
1173 #endif
1174 pppol2tp_copy_stats(&stats, &tunnel->stats);
1175 if (copy_to_user((void __user *) arg, &stats, sizeof(stats))) {
1176 err = -EFAULT;
1177 break;
1178 }
1179 l2tp_info(tunnel, PPPOL2TP_MSG_CONTROL, "%s: get L2TP stats\n",
1180 tunnel->name);
1181 err = 0;
1182 break;
1183
1184 default:
1185 err = -ENOSYS;
1186 break;
1187 }
1188
1189 sock_put(sk);
1190
1191 return err;
1192 }
1193
1194 /* Main ioctl() handler.
1195 * Dispatch to tunnel or session helpers depending on the socket.
1196 */
1197 static int pppol2tp_ioctl(struct socket *sock, unsigned int cmd,
1198 unsigned long arg)
1199 {
1200 struct sock *sk = sock->sk;
1201 struct l2tp_session *session;
1202 struct l2tp_tunnel *tunnel;
1203 struct pppol2tp_session *ps;
1204 int err;
1205
1206 if (!sk)
1207 return 0;
1208
1209 err = -EBADF;
1210 if (sock_flag(sk, SOCK_DEAD) != 0)
1211 goto end;
1212
1213 err = -ENOTCONN;
1214 if ((sk->sk_user_data == NULL) ||
1215 (!(sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND))))
1216 goto end;
1217
1218 /* Get session context from the socket */
1219 err = -EBADF;
1220 session = pppol2tp_sock_to_session(sk);
1221 if (session == NULL)
1222 goto end;
1223
1224 /* Special case: if session's session_id is zero, treat ioctl as a
1225 * tunnel ioctl
1226 */
1227 ps = l2tp_session_priv(session);
1228 if ((session->session_id == 0) &&
1229 (session->peer_session_id == 0)) {
1230 err = -EBADF;
1231 tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock);
1232 if (tunnel == NULL)
1233 goto end_put_sess;
1234
1235 err = pppol2tp_tunnel_ioctl(tunnel, cmd, arg);
1236 sock_put(ps->tunnel_sock);
1237 goto end_put_sess;
1238 }
1239
1240 err = pppol2tp_session_ioctl(session, cmd, arg);
1241
1242 end_put_sess:
1243 sock_put(sk);
1244 end:
1245 return err;
1246 }
1247
1248 /*****************************************************************************
1249 * setsockopt() / getsockopt() support.
1250 *
1251 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
1252 * sockets. In order to control kernel tunnel features, we allow userspace to
1253 * create a special "tunnel" PPPoX socket which is used for control only.
1254 * Tunnel PPPoX sockets have session_id == 0 and simply allow the user
1255 * application to issue L2TP setsockopt(), getsockopt() and ioctl() calls.
1256 *****************************************************************************/
1257
1258 /* Tunnel setsockopt() helper.
1259 */
1260 static int pppol2tp_tunnel_setsockopt(struct sock *sk,
1261 struct l2tp_tunnel *tunnel,
1262 int optname, int val)
1263 {
1264 int err = 0;
1265
1266 switch (optname) {
1267 case PPPOL2TP_SO_DEBUG:
1268 tunnel->debug = val;
1269 l2tp_info(tunnel, PPPOL2TP_MSG_CONTROL, "%s: set debug=%x\n",
1270 tunnel->name, tunnel->debug);
1271 break;
1272
1273 default:
1274 err = -ENOPROTOOPT;
1275 break;
1276 }
1277
1278 return err;
1279 }
1280
1281 /* Session setsockopt helper.
1282 */
1283 static int pppol2tp_session_setsockopt(struct sock *sk,
1284 struct l2tp_session *session,
1285 int optname, int val)
1286 {
1287 int err = 0;
1288 struct pppol2tp_session *ps = l2tp_session_priv(session);
1289
1290 switch (optname) {
1291 case PPPOL2TP_SO_RECVSEQ:
1292 if ((val != 0) && (val != 1)) {
1293 err = -EINVAL;
1294 break;
1295 }
1296 session->recv_seq = val ? -1 : 0;
1297 l2tp_info(session, PPPOL2TP_MSG_CONTROL,
1298 "%s: set recv_seq=%d\n",
1299 session->name, session->recv_seq);
1300 break;
1301
1302 case PPPOL2TP_SO_SENDSEQ:
1303 if ((val != 0) && (val != 1)) {
1304 err = -EINVAL;
1305 break;
1306 }
1307 session->send_seq = val ? -1 : 0;
1308 {
1309 struct sock *ssk = ps->sock;
1310 struct pppox_sock *po = pppox_sk(ssk);
1311 po->chan.hdrlen = val ? PPPOL2TP_L2TP_HDR_SIZE_SEQ :
1312 PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
1313 }
1314 l2tp_session_set_header_len(session, session->tunnel->version);
1315 l2tp_info(session, PPPOL2TP_MSG_CONTROL,
1316 "%s: set send_seq=%d\n",
1317 session->name, session->send_seq);
1318 break;
1319
1320 case PPPOL2TP_SO_LNSMODE:
1321 if ((val != 0) && (val != 1)) {
1322 err = -EINVAL;
1323 break;
1324 }
1325 session->lns_mode = val ? -1 : 0;
1326 l2tp_info(session, PPPOL2TP_MSG_CONTROL,
1327 "%s: set lns_mode=%d\n",
1328 session->name, session->lns_mode);
1329 break;
1330
1331 case PPPOL2TP_SO_DEBUG:
1332 session->debug = val;
1333 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: set debug=%x\n",
1334 session->name, session->debug);
1335 break;
1336
1337 case PPPOL2TP_SO_REORDERTO:
1338 session->reorder_timeout = msecs_to_jiffies(val);
1339 l2tp_info(session, PPPOL2TP_MSG_CONTROL,
1340 "%s: set reorder_timeout=%d\n",
1341 session->name, session->reorder_timeout);
1342 break;
1343
1344 default:
1345 err = -ENOPROTOOPT;
1346 break;
1347 }
1348
1349 return err;
1350 }
1351
1352 /* Main setsockopt() entry point.
1353 * Does API checks, then calls either the tunnel or session setsockopt
1354 * handler, according to whether the PPPoL2TP socket is a for a regular
1355 * session or the special tunnel type.
1356 */
1357 static int pppol2tp_setsockopt(struct socket *sock, int level, int optname,
1358 char __user *optval, unsigned int optlen)
1359 {
1360 struct sock *sk = sock->sk;
1361 struct l2tp_session *session;
1362 struct l2tp_tunnel *tunnel;
1363 struct pppol2tp_session *ps;
1364 int val;
1365 int err;
1366
1367 if (level != SOL_PPPOL2TP)
1368 return -EINVAL;
1369
1370 if (optlen < sizeof(int))
1371 return -EINVAL;
1372
1373 if (get_user(val, (int __user *)optval))
1374 return -EFAULT;
1375
1376 err = -ENOTCONN;
1377 if (sk->sk_user_data == NULL)
1378 goto end;
1379
1380 /* Get session context from the socket */
1381 err = -EBADF;
1382 session = pppol2tp_sock_to_session(sk);
1383 if (session == NULL)
1384 goto end;
1385
1386 /* Special case: if session_id == 0x0000, treat as operation on tunnel
1387 */
1388 ps = l2tp_session_priv(session);
1389 if ((session->session_id == 0) &&
1390 (session->peer_session_id == 0)) {
1391 err = -EBADF;
1392 tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock);
1393 if (tunnel == NULL)
1394 goto end_put_sess;
1395
1396 err = pppol2tp_tunnel_setsockopt(sk, tunnel, optname, val);
1397 sock_put(ps->tunnel_sock);
1398 } else
1399 err = pppol2tp_session_setsockopt(sk, session, optname, val);
1400
1401 err = 0;
1402
1403 end_put_sess:
1404 sock_put(sk);
1405 end:
1406 return err;
1407 }
1408
1409 /* Tunnel getsockopt helper. Called with sock locked.
1410 */
1411 static int pppol2tp_tunnel_getsockopt(struct sock *sk,
1412 struct l2tp_tunnel *tunnel,
1413 int optname, int *val)
1414 {
1415 int err = 0;
1416
1417 switch (optname) {
1418 case PPPOL2TP_SO_DEBUG:
1419 *val = tunnel->debug;
1420 l2tp_info(tunnel, PPPOL2TP_MSG_CONTROL, "%s: get debug=%x\n",
1421 tunnel->name, tunnel->debug);
1422 break;
1423
1424 default:
1425 err = -ENOPROTOOPT;
1426 break;
1427 }
1428
1429 return err;
1430 }
1431
1432 /* Session getsockopt helper. Called with sock locked.
1433 */
1434 static int pppol2tp_session_getsockopt(struct sock *sk,
1435 struct l2tp_session *session,
1436 int optname, int *val)
1437 {
1438 int err = 0;
1439
1440 switch (optname) {
1441 case PPPOL2TP_SO_RECVSEQ:
1442 *val = session->recv_seq;
1443 l2tp_info(session, PPPOL2TP_MSG_CONTROL,
1444 "%s: get recv_seq=%d\n", session->name, *val);
1445 break;
1446
1447 case PPPOL2TP_SO_SENDSEQ:
1448 *val = session->send_seq;
1449 l2tp_info(session, PPPOL2TP_MSG_CONTROL,
1450 "%s: get send_seq=%d\n", session->name, *val);
1451 break;
1452
1453 case PPPOL2TP_SO_LNSMODE:
1454 *val = session->lns_mode;
1455 l2tp_info(session, PPPOL2TP_MSG_CONTROL,
1456 "%s: get lns_mode=%d\n", session->name, *val);
1457 break;
1458
1459 case PPPOL2TP_SO_DEBUG:
1460 *val = session->debug;
1461 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: get debug=%d\n",
1462 session->name, *val);
1463 break;
1464
1465 case PPPOL2TP_SO_REORDERTO:
1466 *val = (int) jiffies_to_msecs(session->reorder_timeout);
1467 l2tp_info(session, PPPOL2TP_MSG_CONTROL,
1468 "%s: get reorder_timeout=%d\n", session->name, *val);
1469 break;
1470
1471 default:
1472 err = -ENOPROTOOPT;
1473 }
1474
1475 return err;
1476 }
1477
1478 /* Main getsockopt() entry point.
1479 * Does API checks, then calls either the tunnel or session getsockopt
1480 * handler, according to whether the PPPoX socket is a for a regular session
1481 * or the special tunnel type.
1482 */
1483 static int pppol2tp_getsockopt(struct socket *sock, int level, int optname,
1484 char __user *optval, int __user *optlen)
1485 {
1486 struct sock *sk = sock->sk;
1487 struct l2tp_session *session;
1488 struct l2tp_tunnel *tunnel;
1489 int val, len;
1490 int err;
1491 struct pppol2tp_session *ps;
1492
1493 if (level != SOL_PPPOL2TP)
1494 return -EINVAL;
1495
1496 if (get_user(len, optlen))
1497 return -EFAULT;
1498
1499 len = min_t(unsigned int, len, sizeof(int));
1500
1501 if (len < 0)
1502 return -EINVAL;
1503
1504 err = -ENOTCONN;
1505 if (sk->sk_user_data == NULL)
1506 goto end;
1507
1508 /* Get the session context */
1509 err = -EBADF;
1510 session = pppol2tp_sock_to_session(sk);
1511 if (session == NULL)
1512 goto end;
1513
1514 /* Special case: if session_id == 0x0000, treat as operation on tunnel */
1515 ps = l2tp_session_priv(session);
1516 if ((session->session_id == 0) &&
1517 (session->peer_session_id == 0)) {
1518 err = -EBADF;
1519 tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock);
1520 if (tunnel == NULL)
1521 goto end_put_sess;
1522
1523 err = pppol2tp_tunnel_getsockopt(sk, tunnel, optname, &val);
1524 sock_put(ps->tunnel_sock);
1525 } else
1526 err = pppol2tp_session_getsockopt(sk, session, optname, &val);
1527
1528 err = -EFAULT;
1529 if (put_user(len, optlen))
1530 goto end_put_sess;
1531
1532 if (copy_to_user((void __user *) optval, &val, len))
1533 goto end_put_sess;
1534
1535 err = 0;
1536
1537 end_put_sess:
1538 sock_put(sk);
1539 end:
1540 return err;
1541 }
1542
1543 /*****************************************************************************
1544 * /proc filesystem for debug
1545 * Since the original pppol2tp driver provided /proc/net/pppol2tp for
1546 * L2TPv2, we dump only L2TPv2 tunnels and sessions here.
1547 *****************************************************************************/
1548
1549 static unsigned int pppol2tp_net_id;
1550
1551 #ifdef CONFIG_PROC_FS
1552
1553 struct pppol2tp_seq_data {
1554 struct seq_net_private p;
1555 int tunnel_idx; /* current tunnel */
1556 int session_idx; /* index of session within current tunnel */
1557 struct l2tp_tunnel *tunnel;
1558 struct l2tp_session *session; /* NULL means get next tunnel */
1559 };
1560
1561 static void pppol2tp_next_tunnel(struct net *net, struct pppol2tp_seq_data *pd)
1562 {
1563 for (;;) {
1564 pd->tunnel = l2tp_tunnel_find_nth(net, pd->tunnel_idx);
1565 pd->tunnel_idx++;
1566
1567 if (pd->tunnel == NULL)
1568 break;
1569
1570 /* Ignore L2TPv3 tunnels */
1571 if (pd->tunnel->version < 3)
1572 break;
1573 }
1574 }
1575
1576 static void pppol2tp_next_session(struct net *net, struct pppol2tp_seq_data *pd)
1577 {
1578 pd->session = l2tp_session_find_nth(pd->tunnel, pd->session_idx);
1579 pd->session_idx++;
1580
1581 if (pd->session == NULL) {
1582 pd->session_idx = 0;
1583 pppol2tp_next_tunnel(net, pd);
1584 }
1585 }
1586
1587 static void *pppol2tp_seq_start(struct seq_file *m, loff_t *offs)
1588 {
1589 struct pppol2tp_seq_data *pd = SEQ_START_TOKEN;
1590 loff_t pos = *offs;
1591 struct net *net;
1592
1593 if (!pos)
1594 goto out;
1595
1596 BUG_ON(m->private == NULL);
1597 pd = m->private;
1598 net = seq_file_net(m);
1599
1600 if (pd->tunnel == NULL)
1601 pppol2tp_next_tunnel(net, pd);
1602 else
1603 pppol2tp_next_session(net, pd);
1604
1605 /* NULL tunnel and session indicates end of list */
1606 if ((pd->tunnel == NULL) && (pd->session == NULL))
1607 pd = NULL;
1608
1609 out:
1610 return pd;
1611 }
1612
1613 static void *pppol2tp_seq_next(struct seq_file *m, void *v, loff_t *pos)
1614 {
1615 (*pos)++;
1616 return NULL;
1617 }
1618
1619 static void pppol2tp_seq_stop(struct seq_file *p, void *v)
1620 {
1621 /* nothing to do */
1622 }
1623
1624 static void pppol2tp_seq_tunnel_show(struct seq_file *m, void *v)
1625 {
1626 struct l2tp_tunnel *tunnel = v;
1627
1628 seq_printf(m, "\nTUNNEL '%s', %c %d\n",
1629 tunnel->name,
1630 (tunnel == tunnel->sock->sk_user_data) ? 'Y' : 'N',
1631 atomic_read(&tunnel->ref_count) - 1);
1632 seq_printf(m, " %08x %ld/%ld/%ld %ld/%ld/%ld\n",
1633 tunnel->debug,
1634 atomic_long_read(&tunnel->stats.tx_packets),
1635 atomic_long_read(&tunnel->stats.tx_bytes),
1636 atomic_long_read(&tunnel->stats.tx_errors),
1637 atomic_long_read(&tunnel->stats.rx_packets),
1638 atomic_long_read(&tunnel->stats.rx_bytes),
1639 atomic_long_read(&tunnel->stats.rx_errors));
1640 }
1641
1642 static void pppol2tp_seq_session_show(struct seq_file *m, void *v)
1643 {
1644 struct l2tp_session *session = v;
1645 struct l2tp_tunnel *tunnel = session->tunnel;
1646 struct pppol2tp_session *ps = l2tp_session_priv(session);
1647 struct pppox_sock *po = pppox_sk(ps->sock);
1648 u32 ip = 0;
1649 u16 port = 0;
1650
1651 if (tunnel->sock) {
1652 struct inet_sock *inet = inet_sk(tunnel->sock);
1653 ip = ntohl(inet->inet_saddr);
1654 port = ntohs(inet->inet_sport);
1655 }
1656
1657 seq_printf(m, " SESSION '%s' %08X/%d %04X/%04X -> "
1658 "%04X/%04X %d %c\n",
1659 session->name, ip, port,
1660 tunnel->tunnel_id,
1661 session->session_id,
1662 tunnel->peer_tunnel_id,
1663 session->peer_session_id,
1664 ps->sock->sk_state,
1665 (session == ps->sock->sk_user_data) ?
1666 'Y' : 'N');
1667 seq_printf(m, " %d/%d/%c/%c/%s %08x %u\n",
1668 session->mtu, session->mru,
1669 session->recv_seq ? 'R' : '-',
1670 session->send_seq ? 'S' : '-',
1671 session->lns_mode ? "LNS" : "LAC",
1672 session->debug,
1673 jiffies_to_msecs(session->reorder_timeout));
1674 seq_printf(m, " %hu/%hu %ld/%ld/%ld %ld/%ld/%ld\n",
1675 session->nr, session->ns,
1676 atomic_long_read(&session->stats.tx_packets),
1677 atomic_long_read(&session->stats.tx_bytes),
1678 atomic_long_read(&session->stats.tx_errors),
1679 atomic_long_read(&session->stats.rx_packets),
1680 atomic_long_read(&session->stats.rx_bytes),
1681 atomic_long_read(&session->stats.rx_errors));
1682
1683 if (po)
1684 seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan));
1685 }
1686
1687 static int pppol2tp_seq_show(struct seq_file *m, void *v)
1688 {
1689 struct pppol2tp_seq_data *pd = v;
1690
1691 /* display header on line 1 */
1692 if (v == SEQ_START_TOKEN) {
1693 seq_puts(m, "PPPoL2TP driver info, " PPPOL2TP_DRV_VERSION "\n");
1694 seq_puts(m, "TUNNEL name, user-data-ok session-count\n");
1695 seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
1696 seq_puts(m, " SESSION name, addr/port src-tid/sid "
1697 "dest-tid/sid state user-data-ok\n");
1698 seq_puts(m, " mtu/mru/rcvseq/sendseq/lns debug reorderto\n");
1699 seq_puts(m, " nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
1700 goto out;
1701 }
1702
1703 /* Show the tunnel or session context.
1704 */
1705 if (pd->session == NULL)
1706 pppol2tp_seq_tunnel_show(m, pd->tunnel);
1707 else
1708 pppol2tp_seq_session_show(m, pd->session);
1709
1710 out:
1711 return 0;
1712 }
1713
1714 static const struct seq_operations pppol2tp_seq_ops = {
1715 .start = pppol2tp_seq_start,
1716 .next = pppol2tp_seq_next,
1717 .stop = pppol2tp_seq_stop,
1718 .show = pppol2tp_seq_show,
1719 };
1720
1721 /* Called when our /proc file is opened. We allocate data for use when
1722 * iterating our tunnel / session contexts and store it in the private
1723 * data of the seq_file.
1724 */
1725 static int pppol2tp_proc_open(struct inode *inode, struct file *file)
1726 {
1727 return seq_open_net(inode, file, &pppol2tp_seq_ops,
1728 sizeof(struct pppol2tp_seq_data));
1729 }
1730
1731 static const struct file_operations pppol2tp_proc_fops = {
1732 .owner = THIS_MODULE,
1733 .open = pppol2tp_proc_open,
1734 .read = seq_read,
1735 .llseek = seq_lseek,
1736 .release = seq_release_net,
1737 };
1738
1739 #endif /* CONFIG_PROC_FS */
1740
1741 /*****************************************************************************
1742 * Network namespace
1743 *****************************************************************************/
1744
1745 static __net_init int pppol2tp_init_net(struct net *net)
1746 {
1747 struct proc_dir_entry *pde;
1748 int err = 0;
1749
1750 pde = proc_create("pppol2tp", S_IRUGO, net->proc_net,
1751 &pppol2tp_proc_fops);
1752 if (!pde) {
1753 err = -ENOMEM;
1754 goto out;
1755 }
1756
1757 out:
1758 return err;
1759 }
1760
1761 static __net_exit void pppol2tp_exit_net(struct net *net)
1762 {
1763 remove_proc_entry("pppol2tp", net->proc_net);
1764 }
1765
1766 static struct pernet_operations pppol2tp_net_ops = {
1767 .init = pppol2tp_init_net,
1768 .exit = pppol2tp_exit_net,
1769 .id = &pppol2tp_net_id,
1770 };
1771
1772 /*****************************************************************************
1773 * Init and cleanup
1774 *****************************************************************************/
1775
1776 static const struct proto_ops pppol2tp_ops = {
1777 .family = AF_PPPOX,
1778 .owner = THIS_MODULE,
1779 .release = pppol2tp_release,
1780 .bind = sock_no_bind,
1781 .connect = pppol2tp_connect,
1782 .socketpair = sock_no_socketpair,
1783 .accept = sock_no_accept,
1784 .getname = pppol2tp_getname,
1785 .poll = datagram_poll,
1786 .listen = sock_no_listen,
1787 .shutdown = sock_no_shutdown,
1788 .setsockopt = pppol2tp_setsockopt,
1789 .getsockopt = pppol2tp_getsockopt,
1790 .sendmsg = pppol2tp_sendmsg,
1791 .recvmsg = pppol2tp_recvmsg,
1792 .mmap = sock_no_mmap,
1793 .ioctl = pppox_ioctl,
1794 };
1795
1796 static const struct pppox_proto pppol2tp_proto = {
1797 .create = pppol2tp_create,
1798 .ioctl = pppol2tp_ioctl,
1799 .owner = THIS_MODULE,
1800 };
1801
1802 #ifdef CONFIG_L2TP_V3
1803
1804 static const struct l2tp_nl_cmd_ops pppol2tp_nl_cmd_ops = {
1805 .session_create = pppol2tp_session_create,
1806 .session_delete = l2tp_session_delete,
1807 };
1808
1809 #endif /* CONFIG_L2TP_V3 */
1810
1811 static int __init pppol2tp_init(void)
1812 {
1813 int err;
1814
1815 err = register_pernet_device(&pppol2tp_net_ops);
1816 if (err)
1817 goto out;
1818
1819 err = proto_register(&pppol2tp_sk_proto, 0);
1820 if (err)
1821 goto out_unregister_pppol2tp_pernet;
1822
1823 err = register_pppox_proto(PX_PROTO_OL2TP, &pppol2tp_proto);
1824 if (err)
1825 goto out_unregister_pppol2tp_proto;
1826
1827 #ifdef CONFIG_L2TP_V3
1828 err = l2tp_nl_register_ops(L2TP_PWTYPE_PPP, &pppol2tp_nl_cmd_ops);
1829 if (err)
1830 goto out_unregister_pppox;
1831 #endif
1832
1833 pr_info("PPPoL2TP kernel driver, %s\n", PPPOL2TP_DRV_VERSION);
1834
1835 out:
1836 return err;
1837
1838 #ifdef CONFIG_L2TP_V3
1839 out_unregister_pppox:
1840 unregister_pppox_proto(PX_PROTO_OL2TP);
1841 #endif
1842 out_unregister_pppol2tp_proto:
1843 proto_unregister(&pppol2tp_sk_proto);
1844 out_unregister_pppol2tp_pernet:
1845 unregister_pernet_device(&pppol2tp_net_ops);
1846 goto out;
1847 }
1848
1849 static void __exit pppol2tp_exit(void)
1850 {
1851 #ifdef CONFIG_L2TP_V3
1852 l2tp_nl_unregister_ops(L2TP_PWTYPE_PPP);
1853 #endif
1854 unregister_pppox_proto(PX_PROTO_OL2TP);
1855 proto_unregister(&pppol2tp_sk_proto);
1856 unregister_pernet_device(&pppol2tp_net_ops);
1857 }
1858
1859 module_init(pppol2tp_init);
1860 module_exit(pppol2tp_exit);
1861
1862 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
1863 MODULE_DESCRIPTION("PPP over L2TP over UDP");
1864 MODULE_LICENSE("GPL");
1865 MODULE_VERSION(PPPOL2TP_DRV_VERSION);
1866 MODULE_ALIAS("pppox-proto-" __stringify(PX_PROTO_OL2TP));
Linux kernel - Deliverables
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