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Merge tag 'nfs-for-3.18-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
[mirror_ubuntu-eoan-kernel.git] / net / l2tp / l2tp_ppp.c
1 /*****************************************************************************
2 * Linux PPP over L2TP (PPPoX/PPPoL2TP) Sockets
3 *
4 * PPPoX --- Generic PPP encapsulation socket family
5 * PPPoL2TP --- PPP over L2TP (RFC 2661)
6 *
7 * Version: 2.0.0
8 *
9 * Authors: James Chapman (jchapman@katalix.com)
10 *
11 * Based on original work by Martijn van Oosterhout <kleptog@svana.org>
12 *
13 * License:
14 * This program is free software; you can redistribute it and/or
15 * modify it under the terms of the GNU General Public License
16 * as published by the Free Software Foundation; either version
17 * 2 of the License, or (at your option) any later version.
18 *
19 */
20
21 /* This driver handles only L2TP data frames; control frames are handled by a
22 * userspace application.
23 *
24 * To send data in an L2TP session, userspace opens a PPPoL2TP socket and
25 * attaches it to a bound UDP socket with local tunnel_id / session_id and
26 * peer tunnel_id / session_id set. Data can then be sent or received using
27 * regular socket sendmsg() / recvmsg() calls. Kernel parameters of the socket
28 * can be read or modified using ioctl() or [gs]etsockopt() calls.
29 *
30 * When a PPPoL2TP socket is connected with local and peer session_id values
31 * zero, the socket is treated as a special tunnel management socket.
32 *
33 * Here's example userspace code to create a socket for sending/receiving data
34 * over an L2TP session:-
35 *
36 * struct sockaddr_pppol2tp sax;
37 * int fd;
38 * int session_fd;
39 *
40 * fd = socket(AF_PPPOX, SOCK_DGRAM, PX_PROTO_OL2TP);
41 *
42 * sax.sa_family = AF_PPPOX;
43 * sax.sa_protocol = PX_PROTO_OL2TP;
44 * sax.pppol2tp.fd = tunnel_fd; // bound UDP socket
45 * sax.pppol2tp.addr.sin_addr.s_addr = addr->sin_addr.s_addr;
46 * sax.pppol2tp.addr.sin_port = addr->sin_port;
47 * sax.pppol2tp.addr.sin_family = AF_INET;
48 * sax.pppol2tp.s_tunnel = tunnel_id;
49 * sax.pppol2tp.s_session = session_id;
50 * sax.pppol2tp.d_tunnel = peer_tunnel_id;
51 * sax.pppol2tp.d_session = peer_session_id;
52 *
53 * session_fd = connect(fd, (struct sockaddr *)&sax, sizeof(sax));
54 *
55 * A pppd plugin that allows PPP traffic to be carried over L2TP using
56 * this driver is available from the OpenL2TP project at
57 * http://openl2tp.sourceforge.net.
58 */
59
60 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
61
62 #include <linux/module.h>
63 #include <linux/string.h>
64 #include <linux/list.h>
65 #include <linux/uaccess.h>
66
67 #include <linux/kernel.h>
68 #include <linux/spinlock.h>
69 #include <linux/kthread.h>
70 #include <linux/sched.h>
71 #include <linux/slab.h>
72 #include <linux/errno.h>
73 #include <linux/jiffies.h>
74
75 #include <linux/netdevice.h>
76 #include <linux/net.h>
77 #include <linux/inetdevice.h>
78 #include <linux/skbuff.h>
79 #include <linux/init.h>
80 #include <linux/ip.h>
81 #include <linux/udp.h>
82 #include <linux/if_pppox.h>
83 #include <linux/if_pppol2tp.h>
84 #include <net/sock.h>
85 #include <linux/ppp_channel.h>
86 #include <linux/ppp_defs.h>
87 #include <linux/ppp-ioctl.h>
88 #include <linux/file.h>
89 #include <linux/hash.h>
90 #include <linux/sort.h>
91 #include <linux/proc_fs.h>
92 #include <linux/l2tp.h>
93 #include <linux/nsproxy.h>
94 #include <net/net_namespace.h>
95 #include <net/netns/generic.h>
96 #include <net/dst.h>
97 #include <net/ip.h>
98 #include <net/udp.h>
99 #include <net/xfrm.h>
100 #include <net/inet_common.h>
101
102 #include <asm/byteorder.h>
103 #include <linux/atomic.h>
104
105 #include "l2tp_core.h"
106
107 #define PPPOL2TP_DRV_VERSION "V2.0"
108
109 /* Space for UDP, L2TP and PPP headers */
110 #define PPPOL2TP_HEADER_OVERHEAD 40
111
112 /* Number of bytes to build transmit L2TP headers.
113 * Unfortunately the size is different depending on whether sequence numbers
114 * are enabled.
115 */
116 #define PPPOL2TP_L2TP_HDR_SIZE_SEQ 10
117 #define PPPOL2TP_L2TP_HDR_SIZE_NOSEQ 6
118
119 /* Private data of each session. This data lives at the end of struct
120 * l2tp_session, referenced via session->priv[].
121 */
122 struct pppol2tp_session {
123 int owner; /* pid that opened the socket */
124
125 struct sock *sock; /* Pointer to the session
126 * PPPoX socket */
127 struct sock *tunnel_sock; /* Pointer to the tunnel UDP
128 * socket */
129 int flags; /* accessed by PPPIOCGFLAGS.
130 * Unused. */
131 };
132
133 static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb);
134
135 static const struct ppp_channel_ops pppol2tp_chan_ops = {
136 .start_xmit = pppol2tp_xmit,
137 };
138
139 static const struct proto_ops pppol2tp_ops;
140
141 /* Helpers to obtain tunnel/session contexts from sockets.
142 */
143 static inline struct l2tp_session *pppol2tp_sock_to_session(struct sock *sk)
144 {
145 struct l2tp_session *session;
146
147 if (sk == NULL)
148 return NULL;
149
150 sock_hold(sk);
151 session = (struct l2tp_session *)(sk->sk_user_data);
152 if (session == NULL) {
153 sock_put(sk);
154 goto out;
155 }
156
157 BUG_ON(session->magic != L2TP_SESSION_MAGIC);
158
159 out:
160 return session;
161 }
162
163 /*****************************************************************************
164 * Receive data handling
165 *****************************************************************************/
166
167 static int pppol2tp_recv_payload_hook(struct sk_buff *skb)
168 {
169 /* Skip PPP header, if present. In testing, Microsoft L2TP clients
170 * don't send the PPP header (PPP header compression enabled), but
171 * other clients can include the header. So we cope with both cases
172 * here. The PPP header is always FF03 when using L2TP.
173 *
174 * Note that skb->data[] isn't dereferenced from a u16 ptr here since
175 * the field may be unaligned.
176 */
177 if (!pskb_may_pull(skb, 2))
178 return 1;
179
180 if ((skb->data[0] == 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_iovec(skb, 0, msg->msg_iov, 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_fromiovec(skb_put(skb, total_len), m->msg_iov,
350 total_len);
351 if (error < 0) {
352 kfree_skb(skb);
353 goto error_put_sess_tun;
354 }
355
356 local_bh_disable();
357 l2tp_xmit_skb(session, skb, session->hdr_len);
358 local_bh_enable();
359
360 sock_put(ps->tunnel_sock);
361 sock_put(sk);
362
363 return total_len;
364
365 error_put_sess_tun:
366 sock_put(ps->tunnel_sock);
367 error_put_sess:
368 sock_put(sk);
369 error:
370 return error;
371 }
372
373 /* Transmit function called by generic PPP driver. Sends PPP frame
374 * over PPPoL2TP socket.
375 *
376 * This is almost the same as pppol2tp_sendmsg(), but rather than
377 * being called with a msghdr from userspace, it is called with a skb
378 * from the kernel.
379 *
380 * The supplied skb from ppp doesn't have enough headroom for the
381 * insertion of L2TP, UDP and IP headers so we need to allocate more
382 * headroom in the skb. This will create a cloned skb. But we must be
383 * careful in the error case because the caller will expect to free
384 * the skb it supplied, not our cloned skb. So we take care to always
385 * leave the original skb unfreed if we return an error.
386 */
387 static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
388 {
389 static const u8 ppph[2] = { 0xff, 0x03 };
390 struct sock *sk = (struct sock *) chan->private;
391 struct sock *sk_tun;
392 struct l2tp_session *session;
393 struct l2tp_tunnel *tunnel;
394 struct pppol2tp_session *ps;
395 int uhlen, headroom;
396
397 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
398 goto abort;
399
400 /* Get session and tunnel contexts from the socket */
401 session = pppol2tp_sock_to_session(sk);
402 if (session == NULL)
403 goto abort;
404
405 ps = l2tp_session_priv(session);
406 sk_tun = ps->tunnel_sock;
407 if (sk_tun == NULL)
408 goto abort_put_sess;
409 tunnel = l2tp_sock_to_tunnel(sk_tun);
410 if (tunnel == NULL)
411 goto abort_put_sess;
412
413 uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0;
414 headroom = NET_SKB_PAD +
415 sizeof(struct iphdr) + /* IP header */
416 uhlen + /* UDP header (if L2TP_ENCAPTYPE_UDP) */
417 session->hdr_len + /* L2TP header */
418 sizeof(ppph); /* PPP header */
419 if (skb_cow_head(skb, headroom))
420 goto abort_put_sess_tun;
421
422 /* Setup PPP header */
423 __skb_push(skb, sizeof(ppph));
424 skb->data[0] = ppph[0];
425 skb->data[1] = ppph[1];
426
427 local_bh_disable();
428 l2tp_xmit_skb(session, skb, session->hdr_len);
429 local_bh_enable();
430
431 sock_put(sk_tun);
432 sock_put(sk);
433 return 1;
434
435 abort_put_sess_tun:
436 sock_put(sk_tun);
437 abort_put_sess:
438 sock_put(sk);
439 abort:
440 /* Free the original skb */
441 kfree_skb(skb);
442 return 1;
443 }
444
445 /*****************************************************************************
446 * Session (and tunnel control) socket create/destroy.
447 *****************************************************************************/
448
449 /* Called by l2tp_core when a session socket is being closed.
450 */
451 static void pppol2tp_session_close(struct l2tp_session *session)
452 {
453 struct pppol2tp_session *ps = l2tp_session_priv(session);
454 struct sock *sk = ps->sock;
455 struct socket *sock = sk->sk_socket;
456
457 BUG_ON(session->magic != L2TP_SESSION_MAGIC);
458
459 if (sock) {
460 inet_shutdown(sock, 2);
461 /* Don't let the session go away before our socket does */
462 l2tp_session_inc_refcount(session);
463 }
464 }
465
466 /* Really kill the session socket. (Called from sock_put() if
467 * refcnt == 0.)
468 */
469 static void pppol2tp_session_destruct(struct sock *sk)
470 {
471 struct l2tp_session *session = sk->sk_user_data;
472 if (session) {
473 sk->sk_user_data = NULL;
474 BUG_ON(session->magic != L2TP_SESSION_MAGIC);
475 l2tp_session_dec_refcount(session);
476 }
477 }
478
479 /* Called when the PPPoX socket (session) is closed.
480 */
481 static int pppol2tp_release(struct socket *sock)
482 {
483 struct sock *sk = sock->sk;
484 struct l2tp_session *session;
485 int error;
486
487 if (!sk)
488 return 0;
489
490 error = -EBADF;
491 lock_sock(sk);
492 if (sock_flag(sk, SOCK_DEAD) != 0)
493 goto error;
494
495 pppox_unbind_sock(sk);
496
497 /* Signal the death of the socket. */
498 sk->sk_state = PPPOX_DEAD;
499 sock_orphan(sk);
500 sock->sk = NULL;
501
502 session = pppol2tp_sock_to_session(sk);
503
504 /* Purge any queued data */
505 if (session != NULL) {
506 __l2tp_session_unhash(session);
507 l2tp_session_queue_purge(session);
508 sock_put(sk);
509 }
510 skb_queue_purge(&sk->sk_receive_queue);
511 skb_queue_purge(&sk->sk_write_queue);
512
513 release_sock(sk);
514
515 /* This will delete the session context via
516 * pppol2tp_session_destruct() if the socket's refcnt drops to
517 * zero.
518 */
519 sock_put(sk);
520
521 return 0;
522
523 error:
524 release_sock(sk);
525 return error;
526 }
527
528 static struct proto pppol2tp_sk_proto = {
529 .name = "PPPOL2TP",
530 .owner = THIS_MODULE,
531 .obj_size = sizeof(struct pppox_sock),
532 };
533
534 static int pppol2tp_backlog_recv(struct sock *sk, struct sk_buff *skb)
535 {
536 int rc;
537
538 rc = l2tp_udp_encap_recv(sk, skb);
539 if (rc)
540 kfree_skb(skb);
541
542 return NET_RX_SUCCESS;
543 }
544
545 /* socket() handler. Initialize a new struct sock.
546 */
547 static int pppol2tp_create(struct net *net, struct socket *sock)
548 {
549 int error = -ENOMEM;
550 struct sock *sk;
551
552 sk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, &pppol2tp_sk_proto);
553 if (!sk)
554 goto out;
555
556 sock_init_data(sock, sk);
557
558 sock->state = SS_UNCONNECTED;
559 sock->ops = &pppol2tp_ops;
560
561 sk->sk_backlog_rcv = pppol2tp_backlog_recv;
562 sk->sk_protocol = PX_PROTO_OL2TP;
563 sk->sk_family = PF_PPPOX;
564 sk->sk_state = PPPOX_NONE;
565 sk->sk_type = SOCK_STREAM;
566 sk->sk_destruct = pppol2tp_session_destruct;
567
568 error = 0;
569
570 out:
571 return error;
572 }
573
574 #if defined(CONFIG_L2TP_DEBUGFS) || defined(CONFIG_L2TP_DEBUGFS_MODULE)
575 static void pppol2tp_show(struct seq_file *m, void *arg)
576 {
577 struct l2tp_session *session = arg;
578 struct pppol2tp_session *ps = l2tp_session_priv(session);
579
580 if (ps) {
581 struct pppox_sock *po = pppox_sk(ps->sock);
582 if (po)
583 seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan));
584 }
585 }
586 #endif
587
588 /* connect() handler. Attach a PPPoX socket to a tunnel UDP socket
589 */
590 static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr,
591 int sockaddr_len, int flags)
592 {
593 struct sock *sk = sock->sk;
594 struct sockaddr_pppol2tp *sp = (struct sockaddr_pppol2tp *) uservaddr;
595 struct pppox_sock *po = pppox_sk(sk);
596 struct l2tp_session *session = NULL;
597 struct l2tp_tunnel *tunnel;
598 struct pppol2tp_session *ps;
599 struct dst_entry *dst;
600 struct l2tp_session_cfg cfg = { 0, };
601 int error = 0;
602 u32 tunnel_id, peer_tunnel_id;
603 u32 session_id, peer_session_id;
604 int ver = 2;
605 int fd;
606
607 lock_sock(sk);
608
609 error = -EINVAL;
610 if (sp->sa_protocol != PX_PROTO_OL2TP)
611 goto end;
612
613 /* Check for already bound sockets */
614 error = -EBUSY;
615 if (sk->sk_state & PPPOX_CONNECTED)
616 goto end;
617
618 /* We don't supporting rebinding anyway */
619 error = -EALREADY;
620 if (sk->sk_user_data)
621 goto end; /* socket is already attached */
622
623 /* Get params from socket address. Handle L2TPv2 and L2TPv3.
624 * This is nasty because there are different sockaddr_pppol2tp
625 * structs for L2TPv2, L2TPv3, over IPv4 and IPv6. We use
626 * the sockaddr size to determine which structure the caller
627 * is using.
628 */
629 peer_tunnel_id = 0;
630 if (sockaddr_len == sizeof(struct sockaddr_pppol2tp)) {
631 fd = sp->pppol2tp.fd;
632 tunnel_id = sp->pppol2tp.s_tunnel;
633 peer_tunnel_id = sp->pppol2tp.d_tunnel;
634 session_id = sp->pppol2tp.s_session;
635 peer_session_id = sp->pppol2tp.d_session;
636 } else if (sockaddr_len == sizeof(struct sockaddr_pppol2tpv3)) {
637 struct sockaddr_pppol2tpv3 *sp3 =
638 (struct sockaddr_pppol2tpv3 *) sp;
639 ver = 3;
640 fd = sp3->pppol2tp.fd;
641 tunnel_id = sp3->pppol2tp.s_tunnel;
642 peer_tunnel_id = sp3->pppol2tp.d_tunnel;
643 session_id = sp3->pppol2tp.s_session;
644 peer_session_id = sp3->pppol2tp.d_session;
645 } else if (sockaddr_len == sizeof(struct sockaddr_pppol2tpin6)) {
646 struct sockaddr_pppol2tpin6 *sp6 =
647 (struct sockaddr_pppol2tpin6 *) sp;
648 fd = sp6->pppol2tp.fd;
649 tunnel_id = sp6->pppol2tp.s_tunnel;
650 peer_tunnel_id = sp6->pppol2tp.d_tunnel;
651 session_id = sp6->pppol2tp.s_session;
652 peer_session_id = sp6->pppol2tp.d_session;
653 } else if (sockaddr_len == sizeof(struct sockaddr_pppol2tpv3in6)) {
654 struct sockaddr_pppol2tpv3in6 *sp6 =
655 (struct sockaddr_pppol2tpv3in6 *) sp;
656 ver = 3;
657 fd = sp6->pppol2tp.fd;
658 tunnel_id = sp6->pppol2tp.s_tunnel;
659 peer_tunnel_id = sp6->pppol2tp.d_tunnel;
660 session_id = sp6->pppol2tp.s_session;
661 peer_session_id = sp6->pppol2tp.d_session;
662 } else {
663 error = -EINVAL;
664 goto end; /* bad socket address */
665 }
666
667 /* Don't bind if tunnel_id is 0 */
668 error = -EINVAL;
669 if (tunnel_id == 0)
670 goto end;
671
672 tunnel = l2tp_tunnel_find(sock_net(sk), tunnel_id);
673
674 /* Special case: create tunnel context if session_id and
675 * peer_session_id is 0. Otherwise look up tunnel using supplied
676 * tunnel id.
677 */
678 if ((session_id == 0) && (peer_session_id == 0)) {
679 if (tunnel == NULL) {
680 struct l2tp_tunnel_cfg tcfg = {
681 .encap = L2TP_ENCAPTYPE_UDP,
682 .debug = 0,
683 };
684 error = l2tp_tunnel_create(sock_net(sk), fd, ver, tunnel_id, peer_tunnel_id, &tcfg, &tunnel);
685 if (error < 0)
686 goto end;
687 }
688 } else {
689 /* Error if we can't find the tunnel */
690 error = -ENOENT;
691 if (tunnel == NULL)
692 goto end;
693
694 /* Error if socket is not prepped */
695 if (tunnel->sock == NULL)
696 goto end;
697 }
698
699 if (tunnel->recv_payload_hook == NULL)
700 tunnel->recv_payload_hook = pppol2tp_recv_payload_hook;
701
702 if (tunnel->peer_tunnel_id == 0)
703 tunnel->peer_tunnel_id = peer_tunnel_id;
704
705 /* Create session if it doesn't already exist. We handle the
706 * case where a session was previously created by the netlink
707 * interface by checking that the session doesn't already have
708 * a socket and its tunnel socket are what we expect. If any
709 * of those checks fail, return EEXIST to the caller.
710 */
711 session = l2tp_session_find(sock_net(sk), tunnel, session_id);
712 if (session == NULL) {
713 /* Default MTU must allow space for UDP/L2TP/PPP
714 * headers.
715 */
716 cfg.mtu = cfg.mru = 1500 - PPPOL2TP_HEADER_OVERHEAD;
717
718 /* Allocate and initialize a new session context. */
719 session = l2tp_session_create(sizeof(struct pppol2tp_session),
720 tunnel, session_id,
721 peer_session_id, &cfg);
722 if (session == NULL) {
723 error = -ENOMEM;
724 goto end;
725 }
726 } else {
727 ps = l2tp_session_priv(session);
728 error = -EEXIST;
729 if (ps->sock != NULL)
730 goto end;
731
732 /* consistency checks */
733 if (ps->tunnel_sock != tunnel->sock)
734 goto end;
735 }
736
737 /* Associate session with its PPPoL2TP socket */
738 ps = l2tp_session_priv(session);
739 ps->owner = current->pid;
740 ps->sock = sk;
741 ps->tunnel_sock = tunnel->sock;
742
743 session->recv_skb = pppol2tp_recv;
744 session->session_close = pppol2tp_session_close;
745 #if defined(CONFIG_L2TP_DEBUGFS) || defined(CONFIG_L2TP_DEBUGFS_MODULE)
746 session->show = pppol2tp_show;
747 #endif
748
749 /* We need to know each time a skb is dropped from the reorder
750 * queue.
751 */
752 session->ref = pppol2tp_session_sock_hold;
753 session->deref = pppol2tp_session_sock_put;
754
755 /* If PMTU discovery was enabled, use the MTU that was discovered */
756 dst = sk_dst_get(tunnel->sock);
757 if (dst != NULL) {
758 u32 pmtu = dst_mtu(dst);
759
760 if (pmtu != 0)
761 session->mtu = session->mru = pmtu -
762 PPPOL2TP_HEADER_OVERHEAD;
763 dst_release(dst);
764 }
765
766 /* Special case: if source & dest session_id == 0x0000, this
767 * socket is being created to manage the tunnel. Just set up
768 * the internal context for use by ioctl() and sockopt()
769 * handlers.
770 */
771 if ((session->session_id == 0) &&
772 (session->peer_session_id == 0)) {
773 error = 0;
774 goto out_no_ppp;
775 }
776
777 /* The only header we need to worry about is the L2TP
778 * header. This size is different depending on whether
779 * sequence numbers are enabled for the data channel.
780 */
781 po->chan.hdrlen = PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
782
783 po->chan.private = sk;
784 po->chan.ops = &pppol2tp_chan_ops;
785 po->chan.mtu = session->mtu;
786
787 error = ppp_register_net_channel(sock_net(sk), &po->chan);
788 if (error)
789 goto end;
790
791 out_no_ppp:
792 /* This is how we get the session context from the socket. */
793 sk->sk_user_data = session;
794 sk->sk_state = PPPOX_CONNECTED;
795 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: created\n",
796 session->name);
797
798 end:
799 release_sock(sk);
800
801 return error;
802 }
803
804 #ifdef CONFIG_L2TP_V3
805
806 /* Called when creating sessions via the netlink interface.
807 */
808 static int pppol2tp_session_create(struct net *net, u32 tunnel_id, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg)
809 {
810 int error;
811 struct l2tp_tunnel *tunnel;
812 struct l2tp_session *session;
813 struct pppol2tp_session *ps;
814
815 tunnel = l2tp_tunnel_find(net, tunnel_id);
816
817 /* Error if we can't find the tunnel */
818 error = -ENOENT;
819 if (tunnel == NULL)
820 goto out;
821
822 /* Error if tunnel socket is not prepped */
823 if (tunnel->sock == NULL)
824 goto out;
825
826 /* Check that this session doesn't already exist */
827 error = -EEXIST;
828 session = l2tp_session_find(net, tunnel, session_id);
829 if (session != NULL)
830 goto out;
831
832 /* Default MTU values. */
833 if (cfg->mtu == 0)
834 cfg->mtu = 1500 - PPPOL2TP_HEADER_OVERHEAD;
835 if (cfg->mru == 0)
836 cfg->mru = cfg->mtu;
837
838 /* Allocate and initialize a new session context. */
839 error = -ENOMEM;
840 session = l2tp_session_create(sizeof(struct pppol2tp_session),
841 tunnel, session_id,
842 peer_session_id, cfg);
843 if (session == NULL)
844 goto out;
845
846 ps = l2tp_session_priv(session);
847 ps->tunnel_sock = tunnel->sock;
848
849 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: created\n",
850 session->name);
851
852 error = 0;
853
854 out:
855 return error;
856 }
857
858 #endif /* CONFIG_L2TP_V3 */
859
860 /* getname() support.
861 */
862 static int pppol2tp_getname(struct socket *sock, struct sockaddr *uaddr,
863 int *usockaddr_len, int peer)
864 {
865 int len = 0;
866 int error = 0;
867 struct l2tp_session *session;
868 struct l2tp_tunnel *tunnel;
869 struct sock *sk = sock->sk;
870 struct inet_sock *inet;
871 struct pppol2tp_session *pls;
872
873 error = -ENOTCONN;
874 if (sk == NULL)
875 goto end;
876 if (sk->sk_state != PPPOX_CONNECTED)
877 goto end;
878
879 error = -EBADF;
880 session = pppol2tp_sock_to_session(sk);
881 if (session == NULL)
882 goto end;
883
884 pls = l2tp_session_priv(session);
885 tunnel = l2tp_sock_to_tunnel(pls->tunnel_sock);
886 if (tunnel == NULL) {
887 error = -EBADF;
888 goto end_put_sess;
889 }
890
891 inet = inet_sk(tunnel->sock);
892 if ((tunnel->version == 2) && (tunnel->sock->sk_family == AF_INET)) {
893 struct sockaddr_pppol2tp sp;
894 len = sizeof(sp);
895 memset(&sp, 0, len);
896 sp.sa_family = AF_PPPOX;
897 sp.sa_protocol = PX_PROTO_OL2TP;
898 sp.pppol2tp.fd = tunnel->fd;
899 sp.pppol2tp.pid = pls->owner;
900 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
901 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
902 sp.pppol2tp.s_session = session->session_id;
903 sp.pppol2tp.d_session = session->peer_session_id;
904 sp.pppol2tp.addr.sin_family = AF_INET;
905 sp.pppol2tp.addr.sin_port = inet->inet_dport;
906 sp.pppol2tp.addr.sin_addr.s_addr = inet->inet_daddr;
907 memcpy(uaddr, &sp, len);
908 #if IS_ENABLED(CONFIG_IPV6)
909 } else if ((tunnel->version == 2) &&
910 (tunnel->sock->sk_family == AF_INET6)) {
911 struct sockaddr_pppol2tpin6 sp;
912
913 len = sizeof(sp);
914 memset(&sp, 0, len);
915 sp.sa_family = AF_PPPOX;
916 sp.sa_protocol = PX_PROTO_OL2TP;
917 sp.pppol2tp.fd = tunnel->fd;
918 sp.pppol2tp.pid = pls->owner;
919 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
920 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
921 sp.pppol2tp.s_session = session->session_id;
922 sp.pppol2tp.d_session = session->peer_session_id;
923 sp.pppol2tp.addr.sin6_family = AF_INET6;
924 sp.pppol2tp.addr.sin6_port = inet->inet_dport;
925 memcpy(&sp.pppol2tp.addr.sin6_addr, &tunnel->sock->sk_v6_daddr,
926 sizeof(tunnel->sock->sk_v6_daddr));
927 memcpy(uaddr, &sp, len);
928 } else if ((tunnel->version == 3) &&
929 (tunnel->sock->sk_family == AF_INET6)) {
930 struct sockaddr_pppol2tpv3in6 sp;
931
932 len = sizeof(sp);
933 memset(&sp, 0, len);
934 sp.sa_family = AF_PPPOX;
935 sp.sa_protocol = PX_PROTO_OL2TP;
936 sp.pppol2tp.fd = tunnel->fd;
937 sp.pppol2tp.pid = pls->owner;
938 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
939 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
940 sp.pppol2tp.s_session = session->session_id;
941 sp.pppol2tp.d_session = session->peer_session_id;
942 sp.pppol2tp.addr.sin6_family = AF_INET6;
943 sp.pppol2tp.addr.sin6_port = inet->inet_dport;
944 memcpy(&sp.pppol2tp.addr.sin6_addr, &tunnel->sock->sk_v6_daddr,
945 sizeof(tunnel->sock->sk_v6_daddr));
946 memcpy(uaddr, &sp, len);
947 #endif
948 } else if (tunnel->version == 3) {
949 struct sockaddr_pppol2tpv3 sp;
950 len = sizeof(sp);
951 memset(&sp, 0, len);
952 sp.sa_family = AF_PPPOX;
953 sp.sa_protocol = PX_PROTO_OL2TP;
954 sp.pppol2tp.fd = tunnel->fd;
955 sp.pppol2tp.pid = pls->owner;
956 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
957 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
958 sp.pppol2tp.s_session = session->session_id;
959 sp.pppol2tp.d_session = session->peer_session_id;
960 sp.pppol2tp.addr.sin_family = AF_INET;
961 sp.pppol2tp.addr.sin_port = inet->inet_dport;
962 sp.pppol2tp.addr.sin_addr.s_addr = inet->inet_daddr;
963 memcpy(uaddr, &sp, len);
964 }
965
966 *usockaddr_len = len;
967
968 sock_put(pls->tunnel_sock);
969 end_put_sess:
970 sock_put(sk);
971 error = 0;
972
973 end:
974 return error;
975 }
976
977 /****************************************************************************
978 * ioctl() handlers.
979 *
980 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
981 * sockets. However, in order to control kernel tunnel features, we allow
982 * userspace to create a special "tunnel" PPPoX socket which is used for
983 * control only. Tunnel PPPoX sockets have session_id == 0 and simply allow
984 * the user application to issue L2TP setsockopt(), getsockopt() and ioctl()
985 * calls.
986 ****************************************************************************/
987
988 static void pppol2tp_copy_stats(struct pppol2tp_ioc_stats *dest,
989 struct l2tp_stats *stats)
990 {
991 dest->tx_packets = atomic_long_read(&stats->tx_packets);
992 dest->tx_bytes = atomic_long_read(&stats->tx_bytes);
993 dest->tx_errors = atomic_long_read(&stats->tx_errors);
994 dest->rx_packets = atomic_long_read(&stats->rx_packets);
995 dest->rx_bytes = atomic_long_read(&stats->rx_bytes);
996 dest->rx_seq_discards = atomic_long_read(&stats->rx_seq_discards);
997 dest->rx_oos_packets = atomic_long_read(&stats->rx_oos_packets);
998 dest->rx_errors = atomic_long_read(&stats->rx_errors);
999 }
1000
1001 /* Session ioctl helper.
1002 */
1003 static int pppol2tp_session_ioctl(struct l2tp_session *session,
1004 unsigned int cmd, unsigned long arg)
1005 {
1006 struct ifreq ifr;
1007 int err = 0;
1008 struct sock *sk;
1009 int val = (int) arg;
1010 struct pppol2tp_session *ps = l2tp_session_priv(session);
1011 struct l2tp_tunnel *tunnel = session->tunnel;
1012 struct pppol2tp_ioc_stats stats;
1013
1014 l2tp_dbg(session, PPPOL2TP_MSG_CONTROL,
1015 "%s: pppol2tp_session_ioctl(cmd=%#x, arg=%#lx)\n",
1016 session->name, cmd, arg);
1017
1018 sk = ps->sock;
1019 sock_hold(sk);
1020
1021 switch (cmd) {
1022 case SIOCGIFMTU:
1023 err = -ENXIO;
1024 if (!(sk->sk_state & PPPOX_CONNECTED))
1025 break;
1026
1027 err = -EFAULT;
1028 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq)))
1029 break;
1030 ifr.ifr_mtu = session->mtu;
1031 if (copy_to_user((void __user *) arg, &ifr, sizeof(struct ifreq)))
1032 break;
1033
1034 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: get mtu=%d\n",
1035 session->name, session->mtu);
1036 err = 0;
1037 break;
1038
1039 case SIOCSIFMTU:
1040 err = -ENXIO;
1041 if (!(sk->sk_state & PPPOX_CONNECTED))
1042 break;
1043
1044 err = -EFAULT;
1045 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq)))
1046 break;
1047
1048 session->mtu = ifr.ifr_mtu;
1049
1050 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: set mtu=%d\n",
1051 session->name, session->mtu);
1052 err = 0;
1053 break;
1054
1055 case PPPIOCGMRU:
1056 err = -ENXIO;
1057 if (!(sk->sk_state & PPPOX_CONNECTED))
1058 break;
1059
1060 err = -EFAULT;
1061 if (put_user(session->mru, (int __user *) arg))
1062 break;
1063
1064 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: get mru=%d\n",
1065 session->name, session->mru);
1066 err = 0;
1067 break;
1068
1069 case PPPIOCSMRU:
1070 err = -ENXIO;
1071 if (!(sk->sk_state & PPPOX_CONNECTED))
1072 break;
1073
1074 err = -EFAULT;
1075 if (get_user(val, (int __user *) arg))
1076 break;
1077
1078 session->mru = val;
1079 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: set mru=%d\n",
1080 session->name, session->mru);
1081 err = 0;
1082 break;
1083
1084 case PPPIOCGFLAGS:
1085 err = -EFAULT;
1086 if (put_user(ps->flags, (int __user *) arg))
1087 break;
1088
1089 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: get flags=%d\n",
1090 session->name, ps->flags);
1091 err = 0;
1092 break;
1093
1094 case PPPIOCSFLAGS:
1095 err = -EFAULT;
1096 if (get_user(val, (int __user *) arg))
1097 break;
1098 ps->flags = val;
1099 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: set flags=%d\n",
1100 session->name, ps->flags);
1101 err = 0;
1102 break;
1103
1104 case PPPIOCGL2TPSTATS:
1105 err = -ENXIO;
1106 if (!(sk->sk_state & PPPOX_CONNECTED))
1107 break;
1108
1109 memset(&stats, 0, sizeof(stats));
1110 stats.tunnel_id = tunnel->tunnel_id;
1111 stats.session_id = session->session_id;
1112 pppol2tp_copy_stats(&stats, &session->stats);
1113 if (copy_to_user((void __user *) arg, &stats,
1114 sizeof(stats)))
1115 break;
1116 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: get L2TP stats\n",
1117 session->name);
1118 err = 0;
1119 break;
1120
1121 default:
1122 err = -ENOSYS;
1123 break;
1124 }
1125
1126 sock_put(sk);
1127
1128 return err;
1129 }
1130
1131 /* Tunnel ioctl helper.
1132 *
1133 * Note the special handling for PPPIOCGL2TPSTATS below. If the ioctl data
1134 * specifies a session_id, the session ioctl handler is called. This allows an
1135 * application to retrieve session stats via a tunnel socket.
1136 */
1137 static int pppol2tp_tunnel_ioctl(struct l2tp_tunnel *tunnel,
1138 unsigned int cmd, unsigned long arg)
1139 {
1140 int err = 0;
1141 struct sock *sk;
1142 struct pppol2tp_ioc_stats stats;
1143
1144 l2tp_dbg(tunnel, PPPOL2TP_MSG_CONTROL,
1145 "%s: pppol2tp_tunnel_ioctl(cmd=%#x, arg=%#lx)\n",
1146 tunnel->name, cmd, arg);
1147
1148 sk = tunnel->sock;
1149 sock_hold(sk);
1150
1151 switch (cmd) {
1152 case PPPIOCGL2TPSTATS:
1153 err = -ENXIO;
1154 if (!(sk->sk_state & PPPOX_CONNECTED))
1155 break;
1156
1157 if (copy_from_user(&stats, (void __user *) arg,
1158 sizeof(stats))) {
1159 err = -EFAULT;
1160 break;
1161 }
1162 if (stats.session_id != 0) {
1163 /* resend to session ioctl handler */
1164 struct l2tp_session *session =
1165 l2tp_session_find(sock_net(sk), tunnel, stats.session_id);
1166 if (session != NULL)
1167 err = pppol2tp_session_ioctl(session, cmd, arg);
1168 else
1169 err = -EBADR;
1170 break;
1171 }
1172 #ifdef CONFIG_XFRM
1173 stats.using_ipsec = (sk->sk_policy[0] || sk->sk_policy[1]) ? 1 : 0;
1174 #endif
1175 pppol2tp_copy_stats(&stats, &tunnel->stats);
1176 if (copy_to_user((void __user *) arg, &stats, sizeof(stats))) {
1177 err = -EFAULT;
1178 break;
1179 }
1180 l2tp_info(tunnel, PPPOL2TP_MSG_CONTROL, "%s: get L2TP stats\n",
1181 tunnel->name);
1182 err = 0;
1183 break;
1184
1185 default:
1186 err = -ENOSYS;
1187 break;
1188 }
1189
1190 sock_put(sk);
1191
1192 return err;
1193 }
1194
1195 /* Main ioctl() handler.
1196 * Dispatch to tunnel or session helpers depending on the socket.
1197 */
1198 static int pppol2tp_ioctl(struct socket *sock, unsigned int cmd,
1199 unsigned long arg)
1200 {
1201 struct sock *sk = sock->sk;
1202 struct l2tp_session *session;
1203 struct l2tp_tunnel *tunnel;
1204 struct pppol2tp_session *ps;
1205 int err;
1206
1207 if (!sk)
1208 return 0;
1209
1210 err = -EBADF;
1211 if (sock_flag(sk, SOCK_DEAD) != 0)
1212 goto end;
1213
1214 err = -ENOTCONN;
1215 if ((sk->sk_user_data == NULL) ||
1216 (!(sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND))))
1217 goto end;
1218
1219 /* Get session context from the socket */
1220 err = -EBADF;
1221 session = pppol2tp_sock_to_session(sk);
1222 if (session == NULL)
1223 goto end;
1224
1225 /* Special case: if session's session_id is zero, treat ioctl as a
1226 * tunnel ioctl
1227 */
1228 ps = l2tp_session_priv(session);
1229 if ((session->session_id == 0) &&
1230 (session->peer_session_id == 0)) {
1231 err = -EBADF;
1232 tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock);
1233 if (tunnel == NULL)
1234 goto end_put_sess;
1235
1236 err = pppol2tp_tunnel_ioctl(tunnel, cmd, arg);
1237 sock_put(ps->tunnel_sock);
1238 goto end_put_sess;
1239 }
1240
1241 err = pppol2tp_session_ioctl(session, cmd, arg);
1242
1243 end_put_sess:
1244 sock_put(sk);
1245 end:
1246 return err;
1247 }
1248
1249 /*****************************************************************************
1250 * setsockopt() / getsockopt() support.
1251 *
1252 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
1253 * sockets. In order to control kernel tunnel features, we allow userspace to
1254 * create a special "tunnel" PPPoX socket which is used for control only.
1255 * Tunnel PPPoX sockets have session_id == 0 and simply allow the user
1256 * application to issue L2TP setsockopt(), getsockopt() and ioctl() calls.
1257 *****************************************************************************/
1258
1259 /* Tunnel setsockopt() helper.
1260 */
1261 static int pppol2tp_tunnel_setsockopt(struct sock *sk,
1262 struct l2tp_tunnel *tunnel,
1263 int optname, int val)
1264 {
1265 int err = 0;
1266
1267 switch (optname) {
1268 case PPPOL2TP_SO_DEBUG:
1269 tunnel->debug = val;
1270 l2tp_info(tunnel, PPPOL2TP_MSG_CONTROL, "%s: set debug=%x\n",
1271 tunnel->name, tunnel->debug);
1272 break;
1273
1274 default:
1275 err = -ENOPROTOOPT;
1276 break;
1277 }
1278
1279 return err;
1280 }
1281
1282 /* Session setsockopt helper.
1283 */
1284 static int pppol2tp_session_setsockopt(struct sock *sk,
1285 struct l2tp_session *session,
1286 int optname, int val)
1287 {
1288 int err = 0;
1289 struct pppol2tp_session *ps = l2tp_session_priv(session);
1290
1291 switch (optname) {
1292 case PPPOL2TP_SO_RECVSEQ:
1293 if ((val != 0) && (val != 1)) {
1294 err = -EINVAL;
1295 break;
1296 }
1297 session->recv_seq = val ? -1 : 0;
1298 l2tp_info(session, PPPOL2TP_MSG_CONTROL,
1299 "%s: set recv_seq=%d\n",
1300 session->name, session->recv_seq);
1301 break;
1302
1303 case PPPOL2TP_SO_SENDSEQ:
1304 if ((val != 0) && (val != 1)) {
1305 err = -EINVAL;
1306 break;
1307 }
1308 session->send_seq = val ? -1 : 0;
1309 {
1310 struct sock *ssk = ps->sock;
1311 struct pppox_sock *po = pppox_sk(ssk);
1312 po->chan.hdrlen = val ? PPPOL2TP_L2TP_HDR_SIZE_SEQ :
1313 PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
1314 }
1315 l2tp_session_set_header_len(session, session->tunnel->version);
1316 l2tp_info(session, PPPOL2TP_MSG_CONTROL,
1317 "%s: set send_seq=%d\n",
1318 session->name, session->send_seq);
1319 break;
1320
1321 case PPPOL2TP_SO_LNSMODE:
1322 if ((val != 0) && (val != 1)) {
1323 err = -EINVAL;
1324 break;
1325 }
1326 session->lns_mode = val ? -1 : 0;
1327 l2tp_info(session, PPPOL2TP_MSG_CONTROL,
1328 "%s: set lns_mode=%d\n",
1329 session->name, session->lns_mode);
1330 break;
1331
1332 case PPPOL2TP_SO_DEBUG:
1333 session->debug = val;
1334 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: set debug=%x\n",
1335 session->name, session->debug);
1336 break;
1337
1338 case PPPOL2TP_SO_REORDERTO:
1339 session->reorder_timeout = msecs_to_jiffies(val);
1340 l2tp_info(session, PPPOL2TP_MSG_CONTROL,
1341 "%s: set reorder_timeout=%d\n",
1342 session->name, session->reorder_timeout);
1343 break;
1344
1345 default:
1346 err = -ENOPROTOOPT;
1347 break;
1348 }
1349
1350 return err;
1351 }
1352
1353 /* Main setsockopt() entry point.
1354 * Does API checks, then calls either the tunnel or session setsockopt
1355 * handler, according to whether the PPPoL2TP socket is a for a regular
1356 * session or the special tunnel type.
1357 */
1358 static int pppol2tp_setsockopt(struct socket *sock, int level, int optname,
1359 char __user *optval, unsigned int optlen)
1360 {
1361 struct sock *sk = sock->sk;
1362 struct l2tp_session *session;
1363 struct l2tp_tunnel *tunnel;
1364 struct pppol2tp_session *ps;
1365 int val;
1366 int err;
1367
1368 if (level != SOL_PPPOL2TP)
1369 return -EINVAL;
1370
1371 if (optlen < sizeof(int))
1372 return -EINVAL;
1373
1374 if (get_user(val, (int __user *)optval))
1375 return -EFAULT;
1376
1377 err = -ENOTCONN;
1378 if (sk->sk_user_data == NULL)
1379 goto end;
1380
1381 /* Get session context from the socket */
1382 err = -EBADF;
1383 session = pppol2tp_sock_to_session(sk);
1384 if (session == NULL)
1385 goto end;
1386
1387 /* Special case: if session_id == 0x0000, treat as operation on tunnel
1388 */
1389 ps = l2tp_session_priv(session);
1390 if ((session->session_id == 0) &&
1391 (session->peer_session_id == 0)) {
1392 err = -EBADF;
1393 tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock);
1394 if (tunnel == NULL)
1395 goto end_put_sess;
1396
1397 err = pppol2tp_tunnel_setsockopt(sk, tunnel, optname, val);
1398 sock_put(ps->tunnel_sock);
1399 } else
1400 err = pppol2tp_session_setsockopt(sk, session, optname, val);
1401
1402 err = 0;
1403
1404 end_put_sess:
1405 sock_put(sk);
1406 end:
1407 return err;
1408 }
1409
1410 /* Tunnel getsockopt helper. Called with sock locked.
1411 */
1412 static int pppol2tp_tunnel_getsockopt(struct sock *sk,
1413 struct l2tp_tunnel *tunnel,
1414 int optname, int *val)
1415 {
1416 int err = 0;
1417
1418 switch (optname) {
1419 case PPPOL2TP_SO_DEBUG:
1420 *val = tunnel->debug;
1421 l2tp_info(tunnel, PPPOL2TP_MSG_CONTROL, "%s: get debug=%x\n",
1422 tunnel->name, tunnel->debug);
1423 break;
1424
1425 default:
1426 err = -ENOPROTOOPT;
1427 break;
1428 }
1429
1430 return err;
1431 }
1432
1433 /* Session getsockopt helper. Called with sock locked.
1434 */
1435 static int pppol2tp_session_getsockopt(struct sock *sk,
1436 struct l2tp_session *session,
1437 int optname, int *val)
1438 {
1439 int err = 0;
1440
1441 switch (optname) {
1442 case PPPOL2TP_SO_RECVSEQ:
1443 *val = session->recv_seq;
1444 l2tp_info(session, PPPOL2TP_MSG_CONTROL,
1445 "%s: get recv_seq=%d\n", session->name, *val);
1446 break;
1447
1448 case PPPOL2TP_SO_SENDSEQ:
1449 *val = session->send_seq;
1450 l2tp_info(session, PPPOL2TP_MSG_CONTROL,
1451 "%s: get send_seq=%d\n", session->name, *val);
1452 break;
1453
1454 case PPPOL2TP_SO_LNSMODE:
1455 *val = session->lns_mode;
1456 l2tp_info(session, PPPOL2TP_MSG_CONTROL,
1457 "%s: get lns_mode=%d\n", session->name, *val);
1458 break;
1459
1460 case PPPOL2TP_SO_DEBUG:
1461 *val = session->debug;
1462 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: get debug=%d\n",
1463 session->name, *val);
1464 break;
1465
1466 case PPPOL2TP_SO_REORDERTO:
1467 *val = (int) jiffies_to_msecs(session->reorder_timeout);
1468 l2tp_info(session, PPPOL2TP_MSG_CONTROL,
1469 "%s: get reorder_timeout=%d\n", session->name, *val);
1470 break;
1471
1472 default:
1473 err = -ENOPROTOOPT;
1474 }
1475
1476 return err;
1477 }
1478
1479 /* Main getsockopt() entry point.
1480 * Does API checks, then calls either the tunnel or session getsockopt
1481 * handler, according to whether the PPPoX socket is a for a regular session
1482 * or the special tunnel type.
1483 */
1484 static int pppol2tp_getsockopt(struct socket *sock, int level, int optname,
1485 char __user *optval, int __user *optlen)
1486 {
1487 struct sock *sk = sock->sk;
1488 struct l2tp_session *session;
1489 struct l2tp_tunnel *tunnel;
1490 int val, len;
1491 int err;
1492 struct pppol2tp_session *ps;
1493
1494 if (level != SOL_PPPOL2TP)
1495 return -EINVAL;
1496
1497 if (get_user(len, optlen))
1498 return -EFAULT;
1499
1500 len = min_t(unsigned int, len, sizeof(int));
1501
1502 if (len < 0)
1503 return -EINVAL;
1504
1505 err = -ENOTCONN;
1506 if (sk->sk_user_data == NULL)
1507 goto end;
1508
1509 /* Get the session context */
1510 err = -EBADF;
1511 session = pppol2tp_sock_to_session(sk);
1512 if (session == NULL)
1513 goto end;
1514
1515 /* Special case: if session_id == 0x0000, treat as operation on tunnel */
1516 ps = l2tp_session_priv(session);
1517 if ((session->session_id == 0) &&
1518 (session->peer_session_id == 0)) {
1519 err = -EBADF;
1520 tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock);
1521 if (tunnel == NULL)
1522 goto end_put_sess;
1523
1524 err = pppol2tp_tunnel_getsockopt(sk, tunnel, optname, &val);
1525 sock_put(ps->tunnel_sock);
1526 } else
1527 err = pppol2tp_session_getsockopt(sk, session, optname, &val);
1528
1529 err = -EFAULT;
1530 if (put_user(len, optlen))
1531 goto end_put_sess;
1532
1533 if (copy_to_user((void __user *) optval, &val, len))
1534 goto end_put_sess;
1535
1536 err = 0;
1537
1538 end_put_sess:
1539 sock_put(sk);
1540 end:
1541 return err;
1542 }
1543
1544 /*****************************************************************************
1545 * /proc filesystem for debug
1546 * Since the original pppol2tp driver provided /proc/net/pppol2tp for
1547 * L2TPv2, we dump only L2TPv2 tunnels and sessions here.
1548 *****************************************************************************/
1549
1550 static unsigned int pppol2tp_net_id;
1551
1552 #ifdef CONFIG_PROC_FS
1553
1554 struct pppol2tp_seq_data {
1555 struct seq_net_private p;
1556 int tunnel_idx; /* current tunnel */
1557 int session_idx; /* index of session within current tunnel */
1558 struct l2tp_tunnel *tunnel;
1559 struct l2tp_session *session; /* NULL means get next tunnel */
1560 };
1561
1562 static void pppol2tp_next_tunnel(struct net *net, struct pppol2tp_seq_data *pd)
1563 {
1564 for (;;) {
1565 pd->tunnel = l2tp_tunnel_find_nth(net, pd->tunnel_idx);
1566 pd->tunnel_idx++;
1567
1568 if (pd->tunnel == NULL)
1569 break;
1570
1571 /* Ignore L2TPv3 tunnels */
1572 if (pd->tunnel->version < 3)
1573 break;
1574 }
1575 }
1576
1577 static void pppol2tp_next_session(struct net *net, struct pppol2tp_seq_data *pd)
1578 {
1579 pd->session = l2tp_session_find_nth(pd->tunnel, pd->session_idx);
1580 pd->session_idx++;
1581
1582 if (pd->session == NULL) {
1583 pd->session_idx = 0;
1584 pppol2tp_next_tunnel(net, pd);
1585 }
1586 }
1587
1588 static void *pppol2tp_seq_start(struct seq_file *m, loff_t *offs)
1589 {
1590 struct pppol2tp_seq_data *pd = SEQ_START_TOKEN;
1591 loff_t pos = *offs;
1592 struct net *net;
1593
1594 if (!pos)
1595 goto out;
1596
1597 BUG_ON(m->private == NULL);
1598 pd = m->private;
1599 net = seq_file_net(m);
1600
1601 if (pd->tunnel == NULL)
1602 pppol2tp_next_tunnel(net, pd);
1603 else
1604 pppol2tp_next_session(net, pd);
1605
1606 /* NULL tunnel and session indicates end of list */
1607 if ((pd->tunnel == NULL) && (pd->session == NULL))
1608 pd = NULL;
1609
1610 out:
1611 return pd;
1612 }
1613
1614 static void *pppol2tp_seq_next(struct seq_file *m, void *v, loff_t *pos)
1615 {
1616 (*pos)++;
1617 return NULL;
1618 }
1619
1620 static void pppol2tp_seq_stop(struct seq_file *p, void *v)
1621 {
1622 /* nothing to do */
1623 }
1624
1625 static void pppol2tp_seq_tunnel_show(struct seq_file *m, void *v)
1626 {
1627 struct l2tp_tunnel *tunnel = v;
1628
1629 seq_printf(m, "\nTUNNEL '%s', %c %d\n",
1630 tunnel->name,
1631 (tunnel == tunnel->sock->sk_user_data) ? 'Y' : 'N',
1632 atomic_read(&tunnel->ref_count) - 1);
1633 seq_printf(m, " %08x %ld/%ld/%ld %ld/%ld/%ld\n",
1634 tunnel->debug,
1635 atomic_long_read(&tunnel->stats.tx_packets),
1636 atomic_long_read(&tunnel->stats.tx_bytes),
1637 atomic_long_read(&tunnel->stats.tx_errors),
1638 atomic_long_read(&tunnel->stats.rx_packets),
1639 atomic_long_read(&tunnel->stats.rx_bytes),
1640 atomic_long_read(&tunnel->stats.rx_errors));
1641 }
1642
1643 static void pppol2tp_seq_session_show(struct seq_file *m, void *v)
1644 {
1645 struct l2tp_session *session = v;
1646 struct l2tp_tunnel *tunnel = session->tunnel;
1647 struct pppol2tp_session *ps = l2tp_session_priv(session);
1648 struct pppox_sock *po = pppox_sk(ps->sock);
1649 u32 ip = 0;
1650 u16 port = 0;
1651
1652 if (tunnel->sock) {
1653 struct inet_sock *inet = inet_sk(tunnel->sock);
1654 ip = ntohl(inet->inet_saddr);
1655 port = ntohs(inet->inet_sport);
1656 }
1657
1658 seq_printf(m, " SESSION '%s' %08X/%d %04X/%04X -> "
1659 "%04X/%04X %d %c\n",
1660 session->name, ip, port,
1661 tunnel->tunnel_id,
1662 session->session_id,
1663 tunnel->peer_tunnel_id,
1664 session->peer_session_id,
1665 ps->sock->sk_state,
1666 (session == ps->sock->sk_user_data) ?
1667 'Y' : 'N');
1668 seq_printf(m, " %d/%d/%c/%c/%s %08x %u\n",
1669 session->mtu, session->mru,
1670 session->recv_seq ? 'R' : '-',
1671 session->send_seq ? 'S' : '-',
1672 session->lns_mode ? "LNS" : "LAC",
1673 session->debug,
1674 jiffies_to_msecs(session->reorder_timeout));
1675 seq_printf(m, " %hu/%hu %ld/%ld/%ld %ld/%ld/%ld\n",
1676 session->nr, session->ns,
1677 atomic_long_read(&session->stats.tx_packets),
1678 atomic_long_read(&session->stats.tx_bytes),
1679 atomic_long_read(&session->stats.tx_errors),
1680 atomic_long_read(&session->stats.rx_packets),
1681 atomic_long_read(&session->stats.rx_bytes),
1682 atomic_long_read(&session->stats.rx_errors));
1683
1684 if (po)
1685 seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan));
1686 }
1687
1688 static int pppol2tp_seq_show(struct seq_file *m, void *v)
1689 {
1690 struct pppol2tp_seq_data *pd = v;
1691
1692 /* display header on line 1 */
1693 if (v == SEQ_START_TOKEN) {
1694 seq_puts(m, "PPPoL2TP driver info, " PPPOL2TP_DRV_VERSION "\n");
1695 seq_puts(m, "TUNNEL name, user-data-ok session-count\n");
1696 seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
1697 seq_puts(m, " SESSION name, addr/port src-tid/sid "
1698 "dest-tid/sid state user-data-ok\n");
1699 seq_puts(m, " mtu/mru/rcvseq/sendseq/lns debug reorderto\n");
1700 seq_puts(m, " nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
1701 goto out;
1702 }
1703
1704 /* Show the tunnel or session context.
1705 */
1706 if (pd->session == NULL)
1707 pppol2tp_seq_tunnel_show(m, pd->tunnel);
1708 else
1709 pppol2tp_seq_session_show(m, pd->session);
1710
1711 out:
1712 return 0;
1713 }
1714
1715 static const struct seq_operations pppol2tp_seq_ops = {
1716 .start = pppol2tp_seq_start,
1717 .next = pppol2tp_seq_next,
1718 .stop = pppol2tp_seq_stop,
1719 .show = pppol2tp_seq_show,
1720 };
1721
1722 /* Called when our /proc file is opened. We allocate data for use when
1723 * iterating our tunnel / session contexts and store it in the private
1724 * data of the seq_file.
1725 */
1726 static int pppol2tp_proc_open(struct inode *inode, struct file *file)
1727 {
1728 return seq_open_net(inode, file, &pppol2tp_seq_ops,
1729 sizeof(struct pppol2tp_seq_data));
1730 }
1731
1732 static const struct file_operations pppol2tp_proc_fops = {
1733 .owner = THIS_MODULE,
1734 .open = pppol2tp_proc_open,
1735 .read = seq_read,
1736 .llseek = seq_lseek,
1737 .release = seq_release_net,
1738 };
1739
1740 #endif /* CONFIG_PROC_FS */
1741
1742 /*****************************************************************************
1743 * Network namespace
1744 *****************************************************************************/
1745
1746 static __net_init int pppol2tp_init_net(struct net *net)
1747 {
1748 struct proc_dir_entry *pde;
1749 int err = 0;
1750
1751 pde = proc_create("pppol2tp", S_IRUGO, net->proc_net,
1752 &pppol2tp_proc_fops);
1753 if (!pde) {
1754 err = -ENOMEM;
1755 goto out;
1756 }
1757
1758 out:
1759 return err;
1760 }
1761
1762 static __net_exit void pppol2tp_exit_net(struct net *net)
1763 {
1764 remove_proc_entry("pppol2tp", net->proc_net);
1765 }
1766
1767 static struct pernet_operations pppol2tp_net_ops = {
1768 .init = pppol2tp_init_net,
1769 .exit = pppol2tp_exit_net,
1770 .id = &pppol2tp_net_id,
1771 };
1772
1773 /*****************************************************************************
1774 * Init and cleanup
1775 *****************************************************************************/
1776
1777 static const struct proto_ops pppol2tp_ops = {
1778 .family = AF_PPPOX,
1779 .owner = THIS_MODULE,
1780 .release = pppol2tp_release,
1781 .bind = sock_no_bind,
1782 .connect = pppol2tp_connect,
1783 .socketpair = sock_no_socketpair,
1784 .accept = sock_no_accept,
1785 .getname = pppol2tp_getname,
1786 .poll = datagram_poll,
1787 .listen = sock_no_listen,
1788 .shutdown = sock_no_shutdown,
1789 .setsockopt = pppol2tp_setsockopt,
1790 .getsockopt = pppol2tp_getsockopt,
1791 .sendmsg = pppol2tp_sendmsg,
1792 .recvmsg = pppol2tp_recvmsg,
1793 .mmap = sock_no_mmap,
1794 .ioctl = pppox_ioctl,
1795 };
1796
1797 static const struct pppox_proto pppol2tp_proto = {
1798 .create = pppol2tp_create,
1799 .ioctl = pppol2tp_ioctl,
1800 .owner = THIS_MODULE,
1801 };
1802
1803 #ifdef CONFIG_L2TP_V3
1804
1805 static const struct l2tp_nl_cmd_ops pppol2tp_nl_cmd_ops = {
1806 .session_create = pppol2tp_session_create,
1807 .session_delete = l2tp_session_delete,
1808 };
1809
1810 #endif /* CONFIG_L2TP_V3 */
1811
1812 static int __init pppol2tp_init(void)
1813 {
1814 int err;
1815
1816 err = register_pernet_device(&pppol2tp_net_ops);
1817 if (err)
1818 goto out;
1819
1820 err = proto_register(&pppol2tp_sk_proto, 0);
1821 if (err)
1822 goto out_unregister_pppol2tp_pernet;
1823
1824 err = register_pppox_proto(PX_PROTO_OL2TP, &pppol2tp_proto);
1825 if (err)
1826 goto out_unregister_pppol2tp_proto;
1827
1828 #ifdef CONFIG_L2TP_V3
1829 err = l2tp_nl_register_ops(L2TP_PWTYPE_PPP, &pppol2tp_nl_cmd_ops);
1830 if (err)
1831 goto out_unregister_pppox;
1832 #endif
1833
1834 pr_info("PPPoL2TP kernel driver, %s\n", PPPOL2TP_DRV_VERSION);
1835
1836 out:
1837 return err;
1838
1839 #ifdef CONFIG_L2TP_V3
1840 out_unregister_pppox:
1841 unregister_pppox_proto(PX_PROTO_OL2TP);
1842 #endif
1843 out_unregister_pppol2tp_proto:
1844 proto_unregister(&pppol2tp_sk_proto);
1845 out_unregister_pppol2tp_pernet:
1846 unregister_pernet_device(&pppol2tp_net_ops);
1847 goto out;
1848 }
1849
1850 static void __exit pppol2tp_exit(void)
1851 {
1852 #ifdef CONFIG_L2TP_V3
1853 l2tp_nl_unregister_ops(L2TP_PWTYPE_PPP);
1854 #endif
1855 unregister_pppox_proto(PX_PROTO_OL2TP);
1856 proto_unregister(&pppol2tp_sk_proto);
1857 unregister_pernet_device(&pppol2tp_net_ops);
1858 }
1859
1860 module_init(pppol2tp_init);
1861 module_exit(pppol2tp_exit);
1862
1863 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
1864 MODULE_DESCRIPTION("PPP over L2TP over UDP");
1865 MODULE_LICENSE("GPL");
1866 MODULE_VERSION(PPPOL2TP_DRV_VERSION);
1867 MODULE_ALIAS("pppox-proto-" __stringify(PX_PROTO_OL2TP));
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