Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*****************************************************************************
3 * Linux PPP over L2TP (PPPoX/PPPoL2TP) Sockets
4 *
5 * PPPoX --- Generic PPP encapsulation socket family
6 * PPPoL2TP --- PPP over L2TP (RFC 2661)
7 *
8 * Version: 2.0.0
9 *
10 * Authors: James Chapman (jchapman@katalix.com)
11 *
12 * Based on original work by Martijn van Oosterhout <kleptog@svana.org>
13 *
14 * License:
15 */
16
17/* This driver handles only L2TP data frames; control frames are handled by a
18 * userspace application.
19 *
20 * To send data in an L2TP session, userspace opens a PPPoL2TP socket and
21 * attaches it to a bound UDP socket with local tunnel_id / session_id and
22 * peer tunnel_id / session_id set. Data can then be sent or received using
23 * regular socket sendmsg() / recvmsg() calls. Kernel parameters of the socket
24 * can be read or modified using ioctl() or [gs]etsockopt() calls.
25 *
26 * When a PPPoL2TP socket is connected with local and peer session_id values
27 * zero, the socket is treated as a special tunnel management socket.
28 *
29 * Here's example userspace code to create a socket for sending/receiving data
30 * over an L2TP session:-
31 *
32 * struct sockaddr_pppol2tp sax;
33 * int fd;
34 * int session_fd;
35 *
36 * fd = socket(AF_PPPOX, SOCK_DGRAM, PX_PROTO_OL2TP);
37 *
38 * sax.sa_family = AF_PPPOX;
39 * sax.sa_protocol = PX_PROTO_OL2TP;
40 * sax.pppol2tp.fd = tunnel_fd; // bound UDP socket
41 * sax.pppol2tp.addr.sin_addr.s_addr = addr->sin_addr.s_addr;
42 * sax.pppol2tp.addr.sin_port = addr->sin_port;
43 * sax.pppol2tp.addr.sin_family = AF_INET;
44 * sax.pppol2tp.s_tunnel = tunnel_id;
45 * sax.pppol2tp.s_session = session_id;
46 * sax.pppol2tp.d_tunnel = peer_tunnel_id;
47 * sax.pppol2tp.d_session = peer_session_id;
48 *
49 * session_fd = connect(fd, (struct sockaddr *)&sax, sizeof(sax));
50 *
51 * A pppd plugin that allows PPP traffic to be carried over L2TP using
52 * this driver is available from the OpenL2TP project at
53 * http://openl2tp.sourceforge.net.
54 */
55
56#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
57
58#include <linux/module.h>
59#include <linux/string.h>
60#include <linux/list.h>
61#include <linux/uaccess.h>
62
63#include <linux/kernel.h>
64#include <linux/spinlock.h>
65#include <linux/kthread.h>
66#include <linux/sched.h>
67#include <linux/slab.h>
68#include <linux/errno.h>
69#include <linux/jiffies.h>
70
71#include <linux/netdevice.h>
72#include <linux/net.h>
73#include <linux/inetdevice.h>
74#include <linux/skbuff.h>
75#include <linux/init.h>
76#include <linux/ip.h>
77#include <linux/udp.h>
78#include <linux/if_pppox.h>
79#include <linux/if_pppol2tp.h>
80#include <net/sock.h>
81#include <linux/ppp_channel.h>
82#include <linux/ppp_defs.h>
83#include <linux/ppp-ioctl.h>
84#include <linux/file.h>
85#include <linux/hash.h>
86#include <linux/sort.h>
87#include <linux/proc_fs.h>
88#include <linux/l2tp.h>
89#include <linux/nsproxy.h>
90#include <net/net_namespace.h>
91#include <net/netns/generic.h>
92#include <net/ip.h>
93#include <net/udp.h>
94#include <net/inet_common.h>
95
96#include <asm/byteorder.h>
97#include <linux/atomic.h>
98
99#include "l2tp_core.h"
100
101#define PPPOL2TP_DRV_VERSION "V2.0"
102
103/* Space for UDP, L2TP and PPP headers */
104#define PPPOL2TP_HEADER_OVERHEAD 40
105
106/* Number of bytes to build transmit L2TP headers.
107 * Unfortunately the size is different depending on whether sequence numbers
108 * are enabled.
109 */
110#define PPPOL2TP_L2TP_HDR_SIZE_SEQ 10
111#define PPPOL2TP_L2TP_HDR_SIZE_NOSEQ 6
112
113/* Private data of each session. This data lives at the end of struct
114 * l2tp_session, referenced via session->priv[].
115 */
116struct pppol2tp_session {
117 int owner; /* pid that opened the socket */
118
119 struct mutex sk_lock; /* Protects .sk */
120 struct sock __rcu *sk; /* Pointer to the session PPPoX socket */
121 struct sock *__sk; /* Copy of .sk, for cleanup */
122};
123
124static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb);
125
126static const struct ppp_channel_ops pppol2tp_chan_ops = {
127 .start_xmit = pppol2tp_xmit,
128};
129
130static const struct proto_ops pppol2tp_ops;
131
132/* Retrieves the pppol2tp socket associated to a session. */
133static struct sock *pppol2tp_session_get_sock(struct l2tp_session *session)
134{
135 struct pppol2tp_session *ps = l2tp_session_priv(session);
136
137 return rcu_dereference(ps->sk);
138}
139
140/* Helpers to obtain tunnel/session contexts from sockets.
141 */
142static struct l2tp_session *pppol2tp_sock_to_session(struct sock *sk)
143{
144 struct l2tp_session *session;
145
146 if (!sk)
147 return NULL;
148
149 rcu_read_lock();
150 session = rcu_dereference_sk_user_data(sk);
151 if (session && refcount_inc_not_zero(&session->ref_count)) {
152 rcu_read_unlock();
153 WARN_ON_ONCE(session->magic != L2TP_SESSION_MAGIC);
154 return session;
155 }
156 rcu_read_unlock();
157
158 return NULL;
159}
160
161/*****************************************************************************
162 * Receive data handling
163 *****************************************************************************/
164
165/* Receive message. This is the recvmsg for the PPPoL2TP socket.
166 */
167static int pppol2tp_recvmsg(struct socket *sock, struct msghdr *msg,
168 size_t len, int flags)
169{
170 int err;
171 struct sk_buff *skb;
172 struct sock *sk = sock->sk;
173
174 err = -EIO;
175 if (sk->sk_state & PPPOX_BOUND)
176 goto end;
177
178 err = 0;
179 skb = skb_recv_datagram(sk, flags, &err);
180 if (!skb)
181 goto end;
182
183 if (len > skb->len)
184 len = skb->len;
185 else if (len < skb->len)
186 msg->msg_flags |= MSG_TRUNC;
187
188 err = skb_copy_datagram_msg(skb, 0, msg, len);
189 if (likely(err == 0))
190 err = len;
191
192 kfree_skb(skb);
193end:
194 return err;
195}
196
197static void pppol2tp_recv(struct l2tp_session *session, struct sk_buff *skb, int data_len)
198{
199 struct sock *sk;
200
201 /* If the socket is bound, send it in to PPP's input queue. Otherwise
202 * queue it on the session socket.
203 */
204 rcu_read_lock();
205 sk = pppol2tp_session_get_sock(session);
206 if (!sk)
207 goto no_sock;
208
209 /* If the first two bytes are 0xFF03, consider that it is the PPP's
210 * Address and Control fields and skip them. The L2TP module has always
211 * worked this way, although, in theory, the use of these fields should
212 * be negotiated and handled at the PPP layer. These fields are
213 * constant: 0xFF is the All-Stations Address and 0x03 the Unnumbered
214 * Information command with Poll/Final bit set to zero (RFC 1662).
215 */
216 if (pskb_may_pull(skb, 2) && skb->data[0] == PPP_ALLSTATIONS &&
217 skb->data[1] == PPP_UI)
218 skb_pull(skb, 2);
219
220 if (sk->sk_state & PPPOX_BOUND) {
221 struct pppox_sock *po;
222
223 po = pppox_sk(sk);
224 ppp_input(&po->chan, skb);
225 } else {
226 if (sock_queue_rcv_skb(sk, skb) < 0) {
227 atomic_long_inc(&session->stats.rx_errors);
228 kfree_skb(skb);
229 }
230 }
231 rcu_read_unlock();
232
233 return;
234
235no_sock:
236 rcu_read_unlock();
237 pr_warn_ratelimited("%s: no socket in recv\n", session->name);
238 kfree_skb(skb);
239}
240
241/************************************************************************
242 * Transmit handling
243 ***********************************************************************/
244
245/* This is the sendmsg for the PPPoL2TP pppol2tp_session socket. We come here
246 * when a user application does a sendmsg() on the session socket. L2TP and
247 * PPP headers must be inserted into the user's data.
248 */
249static int pppol2tp_sendmsg(struct socket *sock, struct msghdr *m,
250 size_t total_len)
251{
252 struct sock *sk = sock->sk;
253 struct sk_buff *skb;
254 int error;
255 struct l2tp_session *session;
256 struct l2tp_tunnel *tunnel;
257 int uhlen;
258
259 error = -ENOTCONN;
260 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
261 goto error;
262
263 /* Get session and tunnel contexts */
264 error = -EBADF;
265 session = pppol2tp_sock_to_session(sk);
266 if (!session)
267 goto error;
268
269 tunnel = session->tunnel;
270
271 uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0;
272
273 /* Allocate a socket buffer */
274 error = -ENOMEM;
275 skb = sock_wmalloc(sk, NET_SKB_PAD + sizeof(struct iphdr) +
276 uhlen + session->hdr_len +
277 2 + total_len, /* 2 bytes for PPP_ALLSTATIONS & PPP_UI */
278 0, GFP_KERNEL);
279 if (!skb)
280 goto error_put_sess;
281
282 /* Reserve space for headers. */
283 skb_reserve(skb, NET_SKB_PAD);
284 skb_reset_network_header(skb);
285 skb_reserve(skb, sizeof(struct iphdr));
286 skb_reset_transport_header(skb);
287 skb_reserve(skb, uhlen);
288
289 /* Add PPP header */
290 skb->data[0] = PPP_ALLSTATIONS;
291 skb->data[1] = PPP_UI;
292 skb_put(skb, 2);
293
294 /* Copy user data into skb */
295 error = memcpy_from_msg(skb_put(skb, total_len), m, total_len);
296 if (error < 0) {
297 kfree_skb(skb);
298 goto error_put_sess;
299 }
300
301 local_bh_disable();
302 l2tp_xmit_skb(session, skb);
303 local_bh_enable();
304
305 l2tp_session_put(session);
306
307 return total_len;
308
309error_put_sess:
310 l2tp_session_put(session);
311error:
312 return error;
313}
314
315/* Transmit function called by generic PPP driver. Sends PPP frame
316 * over PPPoL2TP socket.
317 *
318 * This is almost the same as pppol2tp_sendmsg(), but rather than
319 * being called with a msghdr from userspace, it is called with a skb
320 * from the kernel.
321 *
322 * The supplied skb from ppp doesn't have enough headroom for the
323 * insertion of L2TP, UDP and IP headers so we need to allocate more
324 * headroom in the skb. This will create a cloned skb. But we must be
325 * careful in the error case because the caller will expect to free
326 * the skb it supplied, not our cloned skb. So we take care to always
327 * leave the original skb unfreed if we return an error.
328 */
329static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
330{
331 struct sock *sk = (struct sock *)chan->private;
332 struct l2tp_session *session;
333 struct l2tp_tunnel *tunnel;
334 int uhlen, headroom;
335
336 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
337 goto abort;
338
339 /* Get session and tunnel contexts from the socket */
340 session = pppol2tp_sock_to_session(sk);
341 if (!session)
342 goto abort;
343
344 tunnel = session->tunnel;
345
346 uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0;
347 headroom = NET_SKB_PAD +
348 sizeof(struct iphdr) + /* IP header */
349 uhlen + /* UDP header (if L2TP_ENCAPTYPE_UDP) */
350 session->hdr_len + /* L2TP header */
351 2; /* 2 bytes for PPP_ALLSTATIONS & PPP_UI */
352 if (skb_cow_head(skb, headroom))
353 goto abort_put_sess;
354
355 /* Setup PPP header */
356 __skb_push(skb, 2);
357 skb->data[0] = PPP_ALLSTATIONS;
358 skb->data[1] = PPP_UI;
359
360 local_bh_disable();
361 l2tp_xmit_skb(session, skb);
362 local_bh_enable();
363
364 l2tp_session_put(session);
365
366 return 1;
367
368abort_put_sess:
369 l2tp_session_put(session);
370abort:
371 /* Free the original skb */
372 kfree_skb(skb);
373 return 1;
374}
375
376/*****************************************************************************
377 * Session (and tunnel control) socket create/destroy.
378 *****************************************************************************/
379
380/* Really kill the session socket. (Called from sock_put() if
381 * refcnt == 0.)
382 */
383static void pppol2tp_session_destruct(struct sock *sk)
384{
385 skb_queue_purge(&sk->sk_receive_queue);
386 skb_queue_purge(&sk->sk_write_queue);
387}
388
389static void pppol2tp_session_close(struct l2tp_session *session)
390{
391 struct pppol2tp_session *ps;
392
393 ps = l2tp_session_priv(session);
394 mutex_lock(&ps->sk_lock);
395 ps->__sk = rcu_dereference_protected(ps->sk,
396 lockdep_is_held(&ps->sk_lock));
397 RCU_INIT_POINTER(ps->sk, NULL);
398 mutex_unlock(&ps->sk_lock);
399 if (ps->__sk) {
400 /* detach socket */
401 rcu_assign_sk_user_data(ps->__sk, NULL);
402 sock_put(ps->__sk);
403
404 /* drop ref taken when we referenced socket via sk_user_data */
405 l2tp_session_put(session);
406 }
407}
408
409/* Called when the PPPoX socket (session) is closed.
410 */
411static int pppol2tp_release(struct socket *sock)
412{
413 struct sock *sk = sock->sk;
414 struct l2tp_session *session;
415 int error;
416
417 if (!sk)
418 return 0;
419
420 error = -EBADF;
421 lock_sock(sk);
422 if (sock_flag(sk, SOCK_DEAD) != 0)
423 goto error;
424
425 pppox_unbind_sock(sk);
426
427 /* Signal the death of the socket. */
428 sk->sk_state = PPPOX_DEAD;
429 sock_orphan(sk);
430 sock->sk = NULL;
431
432 session = pppol2tp_sock_to_session(sk);
433 if (session) {
434 l2tp_session_delete(session);
435 /* drop ref taken by pppol2tp_sock_to_session */
436 l2tp_session_put(session);
437 }
438
439 release_sock(sk);
440
441 sock_put(sk);
442
443 return 0;
444
445error:
446 release_sock(sk);
447 return error;
448}
449
450static struct proto pppol2tp_sk_proto = {
451 .name = "PPPOL2TP",
452 .owner = THIS_MODULE,
453 .obj_size = sizeof(struct pppox_sock),
454};
455
456static int pppol2tp_backlog_recv(struct sock *sk, struct sk_buff *skb)
457{
458 int rc;
459
460 rc = l2tp_udp_encap_recv(sk, skb);
461 if (rc)
462 kfree_skb(skb);
463
464 return NET_RX_SUCCESS;
465}
466
467/* socket() handler. Initialize a new struct sock.
468 */
469static int pppol2tp_create(struct net *net, struct socket *sock, int kern)
470{
471 int error = -ENOMEM;
472 struct sock *sk;
473
474 sk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, &pppol2tp_sk_proto, kern);
475 if (!sk)
476 goto out;
477
478 sock_init_data(sock, sk);
479 sock_set_flag(sk, SOCK_RCU_FREE);
480
481 sock->state = SS_UNCONNECTED;
482 sock->ops = &pppol2tp_ops;
483
484 sk->sk_backlog_rcv = pppol2tp_backlog_recv;
485 sk->sk_protocol = PX_PROTO_OL2TP;
486 sk->sk_family = PF_PPPOX;
487 sk->sk_state = PPPOX_NONE;
488 sk->sk_type = SOCK_STREAM;
489 sk->sk_destruct = pppol2tp_session_destruct;
490
491 error = 0;
492
493out:
494 return error;
495}
496
497static void pppol2tp_show(struct seq_file *m, void *arg)
498{
499 struct l2tp_session *session = arg;
500 struct sock *sk;
501
502 rcu_read_lock();
503 sk = pppol2tp_session_get_sock(session);
504 if (sk) {
505 struct pppox_sock *po = pppox_sk(sk);
506
507 seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan));
508 }
509 rcu_read_unlock();
510}
511
512static void pppol2tp_session_init(struct l2tp_session *session)
513{
514 struct pppol2tp_session *ps;
515
516 session->recv_skb = pppol2tp_recv;
517 session->session_close = pppol2tp_session_close;
518 if (IS_ENABLED(CONFIG_L2TP_DEBUGFS))
519 session->show = pppol2tp_show;
520
521 ps = l2tp_session_priv(session);
522 mutex_init(&ps->sk_lock);
523 ps->owner = current->pid;
524}
525
526struct l2tp_connect_info {
527 u8 version;
528 int fd;
529 u32 tunnel_id;
530 u32 peer_tunnel_id;
531 u32 session_id;
532 u32 peer_session_id;
533};
534
535static int pppol2tp_sockaddr_get_info(const void *sa, int sa_len,
536 struct l2tp_connect_info *info)
537{
538 switch (sa_len) {
539 case sizeof(struct sockaddr_pppol2tp):
540 {
541 const struct sockaddr_pppol2tp *sa_v2in4 = sa;
542
543 if (sa_v2in4->sa_protocol != PX_PROTO_OL2TP)
544 return -EINVAL;
545
546 info->version = 2;
547 info->fd = sa_v2in4->pppol2tp.fd;
548 info->tunnel_id = sa_v2in4->pppol2tp.s_tunnel;
549 info->peer_tunnel_id = sa_v2in4->pppol2tp.d_tunnel;
550 info->session_id = sa_v2in4->pppol2tp.s_session;
551 info->peer_session_id = sa_v2in4->pppol2tp.d_session;
552
553 break;
554 }
555 case sizeof(struct sockaddr_pppol2tpv3):
556 {
557 const struct sockaddr_pppol2tpv3 *sa_v3in4 = sa;
558
559 if (sa_v3in4->sa_protocol != PX_PROTO_OL2TP)
560 return -EINVAL;
561
562 info->version = 3;
563 info->fd = sa_v3in4->pppol2tp.fd;
564 info->tunnel_id = sa_v3in4->pppol2tp.s_tunnel;
565 info->peer_tunnel_id = sa_v3in4->pppol2tp.d_tunnel;
566 info->session_id = sa_v3in4->pppol2tp.s_session;
567 info->peer_session_id = sa_v3in4->pppol2tp.d_session;
568
569 break;
570 }
571 case sizeof(struct sockaddr_pppol2tpin6):
572 {
573 const struct sockaddr_pppol2tpin6 *sa_v2in6 = sa;
574
575 if (sa_v2in6->sa_protocol != PX_PROTO_OL2TP)
576 return -EINVAL;
577
578 info->version = 2;
579 info->fd = sa_v2in6->pppol2tp.fd;
580 info->tunnel_id = sa_v2in6->pppol2tp.s_tunnel;
581 info->peer_tunnel_id = sa_v2in6->pppol2tp.d_tunnel;
582 info->session_id = sa_v2in6->pppol2tp.s_session;
583 info->peer_session_id = sa_v2in6->pppol2tp.d_session;
584
585 break;
586 }
587 case sizeof(struct sockaddr_pppol2tpv3in6):
588 {
589 const struct sockaddr_pppol2tpv3in6 *sa_v3in6 = sa;
590
591 if (sa_v3in6->sa_protocol != PX_PROTO_OL2TP)
592 return -EINVAL;
593
594 info->version = 3;
595 info->fd = sa_v3in6->pppol2tp.fd;
596 info->tunnel_id = sa_v3in6->pppol2tp.s_tunnel;
597 info->peer_tunnel_id = sa_v3in6->pppol2tp.d_tunnel;
598 info->session_id = sa_v3in6->pppol2tp.s_session;
599 info->peer_session_id = sa_v3in6->pppol2tp.d_session;
600
601 break;
602 }
603 default:
604 return -EINVAL;
605 }
606
607 return 0;
608}
609
610/* Rough estimation of the maximum payload size a tunnel can transmit without
611 * fragmenting at the lower IP layer. Assumes L2TPv2 with sequence
612 * numbers and no IP option. Not quite accurate, but the result is mostly
613 * unused anyway.
614 */
615static int pppol2tp_tunnel_mtu(const struct l2tp_tunnel *tunnel)
616{
617 int mtu;
618
619 mtu = l2tp_tunnel_dst_mtu(tunnel);
620 if (mtu <= PPPOL2TP_HEADER_OVERHEAD)
621 return 1500 - PPPOL2TP_HEADER_OVERHEAD;
622
623 return mtu - PPPOL2TP_HEADER_OVERHEAD;
624}
625
626static struct l2tp_tunnel *pppol2tp_tunnel_get(struct net *net,
627 const struct l2tp_connect_info *info,
628 bool *new_tunnel)
629{
630 struct l2tp_tunnel *tunnel;
631 int error;
632
633 *new_tunnel = false;
634
635 tunnel = l2tp_tunnel_get(net, info->tunnel_id);
636
637 /* Special case: create tunnel context if session_id and
638 * peer_session_id is 0. Otherwise look up tunnel using supplied
639 * tunnel id.
640 */
641 if (!info->session_id && !info->peer_session_id) {
642 if (!tunnel) {
643 struct l2tp_tunnel_cfg tcfg = {
644 .encap = L2TP_ENCAPTYPE_UDP,
645 };
646
647 /* Prevent l2tp_tunnel_register() from trying to set up
648 * a kernel socket.
649 */
650 if (info->fd < 0)
651 return ERR_PTR(-EBADF);
652
653 error = l2tp_tunnel_create(info->fd,
654 info->version,
655 info->tunnel_id,
656 info->peer_tunnel_id, &tcfg,
657 &tunnel);
658 if (error < 0)
659 return ERR_PTR(error);
660
661 refcount_inc(&tunnel->ref_count);
662 error = l2tp_tunnel_register(tunnel, net, &tcfg);
663 if (error < 0) {
664 kfree(tunnel);
665 return ERR_PTR(error);
666 }
667
668 *new_tunnel = true;
669 }
670 } else {
671 /* Error if we can't find the tunnel */
672 if (!tunnel)
673 return ERR_PTR(-ENOENT);
674
675 /* Error if socket is not prepped */
676 if (!tunnel->sock) {
677 l2tp_tunnel_put(tunnel);
678 return ERR_PTR(-ENOENT);
679 }
680 }
681
682 return tunnel;
683}
684
685/* connect() handler. Attach a PPPoX socket to a tunnel UDP socket
686 */
687static int pppol2tp_connect(struct socket *sock, struct sockaddr_unsized *uservaddr,
688 int sockaddr_len, int flags)
689{
690 struct sock *sk = sock->sk;
691 struct pppox_sock *po = pppox_sk(sk);
692 struct l2tp_session *session = NULL;
693 struct l2tp_connect_info info;
694 struct l2tp_tunnel *tunnel;
695 struct pppol2tp_session *ps;
696 struct l2tp_session_cfg cfg = { 0, };
697 bool drop_refcnt = false;
698 bool new_session = false;
699 bool new_tunnel = false;
700 int error;
701
702 error = pppol2tp_sockaddr_get_info(uservaddr, sockaddr_len, &info);
703 if (error < 0)
704 return error;
705
706 /* Don't bind if tunnel_id is 0 */
707 if (!info.tunnel_id)
708 return -EINVAL;
709
710 tunnel = pppol2tp_tunnel_get(sock_net(sk), &info, &new_tunnel);
711 if (IS_ERR(tunnel))
712 return PTR_ERR(tunnel);
713
714 lock_sock(sk);
715
716 /* Check for already bound sockets */
717 error = -EBUSY;
718 if (sk->sk_state & PPPOX_CONNECTED)
719 goto end;
720
721 /* We don't supporting rebinding anyway */
722 error = -EALREADY;
723 if (sk->sk_user_data)
724 goto end; /* socket is already attached */
725
726 if (tunnel->peer_tunnel_id == 0)
727 tunnel->peer_tunnel_id = info.peer_tunnel_id;
728
729 session = l2tp_session_get(sock_net(sk), tunnel->sock, tunnel->version,
730 info.tunnel_id, info.session_id);
731 if (session) {
732 drop_refcnt = true;
733
734 if (session->pwtype != L2TP_PWTYPE_PPP) {
735 error = -EPROTOTYPE;
736 goto end;
737 }
738
739 ps = l2tp_session_priv(session);
740
741 /* Using a pre-existing session is fine as long as it hasn't
742 * been connected yet.
743 */
744 mutex_lock(&ps->sk_lock);
745 if (rcu_dereference_protected(ps->sk,
746 lockdep_is_held(&ps->sk_lock)) ||
747 ps->__sk) {
748 mutex_unlock(&ps->sk_lock);
749 error = -EEXIST;
750 goto end;
751 }
752 } else {
753 cfg.pw_type = L2TP_PWTYPE_PPP;
754
755 session = l2tp_session_create(sizeof(struct pppol2tp_session),
756 tunnel, info.session_id,
757 info.peer_session_id, &cfg);
758 if (IS_ERR(session)) {
759 error = PTR_ERR(session);
760 goto end;
761 }
762
763 drop_refcnt = true;
764
765 pppol2tp_session_init(session);
766 ps = l2tp_session_priv(session);
767 refcount_inc(&session->ref_count);
768
769 mutex_lock(&ps->sk_lock);
770 error = l2tp_session_register(session, tunnel);
771 if (error < 0) {
772 mutex_unlock(&ps->sk_lock);
773 l2tp_session_put(session);
774 goto end;
775 }
776
777 new_session = true;
778 }
779
780 /* Special case: if source & dest session_id == 0x0000, this
781 * socket is being created to manage the tunnel. Just set up
782 * the internal context for use by ioctl() and sockopt()
783 * handlers.
784 */
785 if (session->session_id == 0 && session->peer_session_id == 0) {
786 error = 0;
787 goto out_no_ppp;
788 }
789
790 /* Reserve enough headroom for the L2TP header with sequence numbers,
791 * which is the largest possible. This is used by the PPP layer to set
792 * the net device's hard_header_len at registration, which must be
793 * sufficient regardless of whether sequence numbers are enabled later.
794 */
795 po->chan.hdrlen = PPPOL2TP_L2TP_HDR_SIZE_SEQ;
796
797 po->chan.private = sk;
798 po->chan.ops = &pppol2tp_chan_ops;
799 po->chan.mtu = pppol2tp_tunnel_mtu(tunnel);
800 po->chan.direct_xmit = true;
801
802 error = ppp_register_net_channel(sock_net(sk), &po->chan);
803 if (error) {
804 mutex_unlock(&ps->sk_lock);
805 goto end;
806 }
807
808out_no_ppp:
809 /* This is how we get the session context from the socket. */
810 sock_hold(sk);
811 rcu_assign_sk_user_data(sk, session);
812 rcu_assign_pointer(ps->sk, sk);
813 mutex_unlock(&ps->sk_lock);
814
815 /* Keep the reference we've grabbed on the session: sk doesn't expect
816 * the session to disappear. pppol2tp_session_close() is responsible
817 * for dropping it.
818 */
819 drop_refcnt = false;
820
821 sk->sk_state = PPPOX_CONNECTED;
822
823end:
824 if (error) {
825 if (new_session)
826 l2tp_session_delete(session);
827 if (new_tunnel)
828 l2tp_tunnel_delete(tunnel);
829 }
830 if (drop_refcnt)
831 l2tp_session_put(session);
832 l2tp_tunnel_put(tunnel);
833 release_sock(sk);
834
835 return error;
836}
837
838#ifdef CONFIG_L2TP_V3
839
840/* Called when creating sessions via the netlink interface. */
841static int pppol2tp_session_create(struct net *net, struct l2tp_tunnel *tunnel,
842 u32 session_id, u32 peer_session_id,
843 struct l2tp_session_cfg *cfg)
844{
845 int error;
846 struct l2tp_session *session;
847
848 /* Error if tunnel socket is not prepped */
849 if (!tunnel->sock) {
850 error = -ENOENT;
851 goto err;
852 }
853
854 /* Allocate and initialize a new session context. */
855 session = l2tp_session_create(sizeof(struct pppol2tp_session),
856 tunnel, session_id,
857 peer_session_id, cfg);
858 if (IS_ERR(session)) {
859 error = PTR_ERR(session);
860 goto err;
861 }
862
863 pppol2tp_session_init(session);
864
865 error = l2tp_session_register(session, tunnel);
866 if (error < 0)
867 goto err_sess;
868
869 return 0;
870
871err_sess:
872 l2tp_session_put(session);
873err:
874 return error;
875}
876
877#endif /* CONFIG_L2TP_V3 */
878
879/* getname() support.
880 */
881static int pppol2tp_getname(struct socket *sock, struct sockaddr *uaddr,
882 int peer)
883{
884 int len = 0;
885 int error = 0;
886 struct l2tp_session *session;
887 struct l2tp_tunnel *tunnel;
888 struct sock *sk = sock->sk;
889 struct inet_sock *inet;
890 struct pppol2tp_session *pls;
891
892 error = -ENOTCONN;
893 if (!sk)
894 goto end;
895 if (!(sk->sk_state & PPPOX_CONNECTED))
896 goto end;
897
898 error = -EBADF;
899 session = pppol2tp_sock_to_session(sk);
900 if (!session)
901 goto end;
902
903 pls = l2tp_session_priv(session);
904 tunnel = session->tunnel;
905
906 inet = inet_sk(tunnel->sock);
907 if (tunnel->version == 2 && tunnel->sock->sk_family == AF_INET) {
908 struct sockaddr_pppol2tp sp;
909
910 len = sizeof(sp);
911 memset(&sp, 0, len);
912 sp.sa_family = AF_PPPOX;
913 sp.sa_protocol = PX_PROTO_OL2TP;
914 sp.pppol2tp.fd = tunnel->fd;
915 sp.pppol2tp.pid = pls->owner;
916 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
917 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
918 sp.pppol2tp.s_session = session->session_id;
919 sp.pppol2tp.d_session = session->peer_session_id;
920 sp.pppol2tp.addr.sin_family = AF_INET;
921 sp.pppol2tp.addr.sin_port = inet->inet_dport;
922 sp.pppol2tp.addr.sin_addr.s_addr = inet->inet_daddr;
923 memcpy(uaddr, &sp, len);
924#if IS_ENABLED(CONFIG_IPV6)
925 } else if (tunnel->version == 2 && tunnel->sock->sk_family == AF_INET6) {
926 struct sockaddr_pppol2tpin6 sp;
927
928 len = sizeof(sp);
929 memset(&sp, 0, len);
930 sp.sa_family = AF_PPPOX;
931 sp.sa_protocol = PX_PROTO_OL2TP;
932 sp.pppol2tp.fd = tunnel->fd;
933 sp.pppol2tp.pid = pls->owner;
934 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
935 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
936 sp.pppol2tp.s_session = session->session_id;
937 sp.pppol2tp.d_session = session->peer_session_id;
938 sp.pppol2tp.addr.sin6_family = AF_INET6;
939 sp.pppol2tp.addr.sin6_port = inet->inet_dport;
940 memcpy(&sp.pppol2tp.addr.sin6_addr, &tunnel->sock->sk_v6_daddr,
941 sizeof(tunnel->sock->sk_v6_daddr));
942 memcpy(uaddr, &sp, len);
943 } else if (tunnel->version == 3 && tunnel->sock->sk_family == AF_INET6) {
944 struct sockaddr_pppol2tpv3in6 sp;
945
946 len = sizeof(sp);
947 memset(&sp, 0, len);
948 sp.sa_family = AF_PPPOX;
949 sp.sa_protocol = PX_PROTO_OL2TP;
950 sp.pppol2tp.fd = tunnel->fd;
951 sp.pppol2tp.pid = pls->owner;
952 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
953 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
954 sp.pppol2tp.s_session = session->session_id;
955 sp.pppol2tp.d_session = session->peer_session_id;
956 sp.pppol2tp.addr.sin6_family = AF_INET6;
957 sp.pppol2tp.addr.sin6_port = inet->inet_dport;
958 memcpy(&sp.pppol2tp.addr.sin6_addr, &tunnel->sock->sk_v6_daddr,
959 sizeof(tunnel->sock->sk_v6_daddr));
960 memcpy(uaddr, &sp, len);
961#endif
962 } else if (tunnel->version == 3) {
963 struct sockaddr_pppol2tpv3 sp;
964
965 len = sizeof(sp);
966 memset(&sp, 0, len);
967 sp.sa_family = AF_PPPOX;
968 sp.sa_protocol = PX_PROTO_OL2TP;
969 sp.pppol2tp.fd = tunnel->fd;
970 sp.pppol2tp.pid = pls->owner;
971 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
972 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
973 sp.pppol2tp.s_session = session->session_id;
974 sp.pppol2tp.d_session = session->peer_session_id;
975 sp.pppol2tp.addr.sin_family = AF_INET;
976 sp.pppol2tp.addr.sin_port = inet->inet_dport;
977 sp.pppol2tp.addr.sin_addr.s_addr = inet->inet_daddr;
978 memcpy(uaddr, &sp, len);
979 }
980
981 error = len;
982
983 l2tp_session_put(session);
984end:
985 return error;
986}
987
988/****************************************************************************
989 * ioctl() handlers.
990 *
991 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
992 * sockets. However, in order to control kernel tunnel features, we allow
993 * userspace to create a special "tunnel" PPPoX socket which is used for
994 * control only. Tunnel PPPoX sockets have session_id == 0 and simply allow
995 * the user application to issue L2TP setsockopt(), getsockopt() and ioctl()
996 * calls.
997 ****************************************************************************/
998
999static void pppol2tp_copy_stats(struct pppol2tp_ioc_stats *dest,
1000 const struct l2tp_stats *stats)
1001{
1002 memset(dest, 0, sizeof(*dest));
1003
1004 dest->tx_packets = atomic_long_read(&stats->tx_packets);
1005 dest->tx_bytes = atomic_long_read(&stats->tx_bytes);
1006 dest->tx_errors = atomic_long_read(&stats->tx_errors);
1007 dest->rx_packets = atomic_long_read(&stats->rx_packets);
1008 dest->rx_bytes = atomic_long_read(&stats->rx_bytes);
1009 dest->rx_seq_discards = atomic_long_read(&stats->rx_seq_discards);
1010 dest->rx_oos_packets = atomic_long_read(&stats->rx_oos_packets);
1011 dest->rx_errors = atomic_long_read(&stats->rx_errors);
1012}
1013
1014static int pppol2tp_tunnel_copy_stats(struct pppol2tp_ioc_stats *stats,
1015 struct l2tp_tunnel *tunnel)
1016{
1017 struct l2tp_session *session;
1018
1019 if (!stats->session_id) {
1020 pppol2tp_copy_stats(stats, &tunnel->stats);
1021 return 0;
1022 }
1023
1024 /* If session_id is set, search the corresponding session in the
1025 * context of this tunnel and record the session's statistics.
1026 */
1027 session = l2tp_session_get(tunnel->l2tp_net, tunnel->sock, tunnel->version,
1028 tunnel->tunnel_id, stats->session_id);
1029 if (!session)
1030 return -EBADR;
1031
1032 if (session->pwtype != L2TP_PWTYPE_PPP) {
1033 l2tp_session_put(session);
1034 return -EBADR;
1035 }
1036
1037 pppol2tp_copy_stats(stats, &session->stats);
1038 l2tp_session_put(session);
1039
1040 return 0;
1041}
1042
1043static int pppol2tp_ioctl(struct socket *sock, unsigned int cmd,
1044 unsigned long arg)
1045{
1046 struct pppol2tp_ioc_stats stats;
1047 struct l2tp_session *session;
1048
1049 switch (cmd) {
1050 case PPPIOCGMRU:
1051 case PPPIOCGFLAGS:
1052 session = sock->sk->sk_user_data;
1053 if (!session)
1054 return -ENOTCONN;
1055
1056 if (WARN_ON(session->magic != L2TP_SESSION_MAGIC))
1057 return -EBADF;
1058
1059 /* Not defined for tunnels */
1060 if (!session->session_id && !session->peer_session_id)
1061 return -ENOSYS;
1062
1063 if (put_user(0, (int __user *)arg))
1064 return -EFAULT;
1065 break;
1066
1067 case PPPIOCSMRU:
1068 case PPPIOCSFLAGS:
1069 session = sock->sk->sk_user_data;
1070 if (!session)
1071 return -ENOTCONN;
1072
1073 if (WARN_ON(session->magic != L2TP_SESSION_MAGIC))
1074 return -EBADF;
1075
1076 /* Not defined for tunnels */
1077 if (!session->session_id && !session->peer_session_id)
1078 return -ENOSYS;
1079
1080 if (!access_ok((int __user *)arg, sizeof(int)))
1081 return -EFAULT;
1082 break;
1083
1084 case PPPIOCGL2TPSTATS:
1085 session = sock->sk->sk_user_data;
1086 if (!session)
1087 return -ENOTCONN;
1088
1089 if (WARN_ON(session->magic != L2TP_SESSION_MAGIC))
1090 return -EBADF;
1091
1092 /* Session 0 represents the parent tunnel */
1093 if (!session->session_id && !session->peer_session_id) {
1094 u32 session_id;
1095 int err;
1096
1097 if (copy_from_user(&stats, (void __user *)arg,
1098 sizeof(stats)))
1099 return -EFAULT;
1100
1101 session_id = stats.session_id;
1102 err = pppol2tp_tunnel_copy_stats(&stats,
1103 session->tunnel);
1104 if (err < 0)
1105 return err;
1106
1107 stats.session_id = session_id;
1108 } else {
1109 pppol2tp_copy_stats(&stats, &session->stats);
1110 stats.session_id = session->session_id;
1111 }
1112 stats.tunnel_id = session->tunnel->tunnel_id;
1113 stats.using_ipsec = l2tp_tunnel_uses_xfrm(session->tunnel);
1114
1115 if (copy_to_user((void __user *)arg, &stats, sizeof(stats)))
1116 return -EFAULT;
1117 break;
1118
1119 default:
1120 return -ENOIOCTLCMD;
1121 }
1122
1123 return 0;
1124}
1125
1126/*****************************************************************************
1127 * setsockopt() / getsockopt() support.
1128 *
1129 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
1130 * sockets. In order to control kernel tunnel features, we allow userspace to
1131 * create a special "tunnel" PPPoX socket which is used for control only.
1132 * Tunnel PPPoX sockets have session_id == 0 and simply allow the user
1133 * application to issue L2TP setsockopt(), getsockopt() and ioctl() calls.
1134 *****************************************************************************/
1135
1136/* Tunnel setsockopt() helper.
1137 */
1138static int pppol2tp_tunnel_setsockopt(struct sock *sk,
1139 struct l2tp_tunnel *tunnel,
1140 int optname, int val)
1141{
1142 int err = 0;
1143
1144 switch (optname) {
1145 case PPPOL2TP_SO_DEBUG:
1146 /* Tunnel debug flags option is deprecated */
1147 break;
1148
1149 default:
1150 err = -ENOPROTOOPT;
1151 break;
1152 }
1153
1154 return err;
1155}
1156
1157/* Session setsockopt helper.
1158 */
1159static int pppol2tp_session_setsockopt(struct sock *sk,
1160 struct l2tp_session *session,
1161 int optname, int val)
1162{
1163 int err = 0;
1164
1165 switch (optname) {
1166 case PPPOL2TP_SO_RECVSEQ:
1167 if (val != 0 && val != 1) {
1168 err = -EINVAL;
1169 break;
1170 }
1171 session->recv_seq = !!val;
1172 break;
1173
1174 case PPPOL2TP_SO_SENDSEQ:
1175 if (val != 0 && val != 1) {
1176 err = -EINVAL;
1177 break;
1178 }
1179 session->send_seq = !!val;
1180 l2tp_session_set_header_len(session, session->tunnel->version,
1181 session->tunnel->encap);
1182 break;
1183
1184 case PPPOL2TP_SO_LNSMODE:
1185 if (val != 0 && val != 1) {
1186 err = -EINVAL;
1187 break;
1188 }
1189 session->lns_mode = !!val;
1190 break;
1191
1192 case PPPOL2TP_SO_DEBUG:
1193 /* Session debug flags option is deprecated */
1194 break;
1195
1196 case PPPOL2TP_SO_REORDERTO:
1197 session->reorder_timeout = msecs_to_jiffies(val);
1198 break;
1199
1200 default:
1201 err = -ENOPROTOOPT;
1202 break;
1203 }
1204
1205 return err;
1206}
1207
1208/* Main setsockopt() entry point.
1209 * Does API checks, then calls either the tunnel or session setsockopt
1210 * handler, according to whether the PPPoL2TP socket is a for a regular
1211 * session or the special tunnel type.
1212 */
1213static int pppol2tp_setsockopt(struct socket *sock, int level, int optname,
1214 sockptr_t optval, unsigned int optlen)
1215{
1216 struct sock *sk = sock->sk;
1217 struct l2tp_session *session;
1218 struct l2tp_tunnel *tunnel;
1219 int val;
1220 int err;
1221
1222 if (level != SOL_PPPOL2TP)
1223 return -EINVAL;
1224
1225 if (optlen < sizeof(int))
1226 return -EINVAL;
1227
1228 if (copy_from_sockptr(&val, optval, sizeof(int)))
1229 return -EFAULT;
1230
1231 err = -ENOTCONN;
1232 if (!sk->sk_user_data)
1233 goto end;
1234
1235 /* Get session context from the socket */
1236 err = -EBADF;
1237 session = pppol2tp_sock_to_session(sk);
1238 if (!session)
1239 goto end;
1240
1241 /* Special case: if session_id == 0x0000, treat as operation on tunnel
1242 */
1243 if (session->session_id == 0 && session->peer_session_id == 0) {
1244 tunnel = session->tunnel;
1245 err = pppol2tp_tunnel_setsockopt(sk, tunnel, optname, val);
1246 } else {
1247 err = pppol2tp_session_setsockopt(sk, session, optname, val);
1248 }
1249
1250 l2tp_session_put(session);
1251end:
1252 return err;
1253}
1254
1255/* Tunnel getsockopt helper. Called with sock locked.
1256 */
1257static int pppol2tp_tunnel_getsockopt(struct sock *sk,
1258 struct l2tp_tunnel *tunnel,
1259 int optname, int *val)
1260{
1261 int err = 0;
1262
1263 switch (optname) {
1264 case PPPOL2TP_SO_DEBUG:
1265 /* Tunnel debug flags option is deprecated */
1266 *val = 0;
1267 break;
1268
1269 default:
1270 err = -ENOPROTOOPT;
1271 break;
1272 }
1273
1274 return err;
1275}
1276
1277/* Session getsockopt helper. Called with sock locked.
1278 */
1279static int pppol2tp_session_getsockopt(struct sock *sk,
1280 struct l2tp_session *session,
1281 int optname, int *val)
1282{
1283 int err = 0;
1284
1285 switch (optname) {
1286 case PPPOL2TP_SO_RECVSEQ:
1287 *val = session->recv_seq;
1288 break;
1289
1290 case PPPOL2TP_SO_SENDSEQ:
1291 *val = session->send_seq;
1292 break;
1293
1294 case PPPOL2TP_SO_LNSMODE:
1295 *val = session->lns_mode;
1296 break;
1297
1298 case PPPOL2TP_SO_DEBUG:
1299 /* Session debug flags option is deprecated */
1300 *val = 0;
1301 break;
1302
1303 case PPPOL2TP_SO_REORDERTO:
1304 *val = (int)jiffies_to_msecs(session->reorder_timeout);
1305 break;
1306
1307 default:
1308 err = -ENOPROTOOPT;
1309 }
1310
1311 return err;
1312}
1313
1314/* Main getsockopt() entry point.
1315 * Does API checks, then calls either the tunnel or session getsockopt
1316 * handler, according to whether the PPPoX socket is a for a regular session
1317 * or the special tunnel type.
1318 */
1319static int pppol2tp_getsockopt(struct socket *sock, int level, int optname,
1320 char __user *optval, int __user *optlen)
1321{
1322 struct sock *sk = sock->sk;
1323 struct l2tp_session *session;
1324 struct l2tp_tunnel *tunnel;
1325 int val, len;
1326 int err;
1327
1328 if (level != SOL_PPPOL2TP)
1329 return -EINVAL;
1330
1331 if (get_user(len, optlen))
1332 return -EFAULT;
1333
1334 if (len < 0)
1335 return -EINVAL;
1336
1337 len = min_t(unsigned int, len, sizeof(int));
1338
1339 err = -ENOTCONN;
1340 if (!sk->sk_user_data)
1341 goto end;
1342
1343 /* Get the session context */
1344 err = -EBADF;
1345 session = pppol2tp_sock_to_session(sk);
1346 if (!session)
1347 goto end;
1348
1349 /* Special case: if session_id == 0x0000, treat as operation on tunnel */
1350 if (session->session_id == 0 && session->peer_session_id == 0) {
1351 tunnel = session->tunnel;
1352 err = pppol2tp_tunnel_getsockopt(sk, tunnel, optname, &val);
1353 if (err)
1354 goto end_put_sess;
1355 } else {
1356 err = pppol2tp_session_getsockopt(sk, session, optname, &val);
1357 if (err)
1358 goto end_put_sess;
1359 }
1360
1361 err = -EFAULT;
1362 if (put_user(len, optlen))
1363 goto end_put_sess;
1364
1365 if (copy_to_user((void __user *)optval, &val, len))
1366 goto end_put_sess;
1367
1368 err = 0;
1369
1370end_put_sess:
1371 l2tp_session_put(session);
1372end:
1373 return err;
1374}
1375
1376/*****************************************************************************
1377 * /proc filesystem for debug
1378 * Since the original pppol2tp driver provided /proc/net/pppol2tp for
1379 * L2TPv2, we dump only L2TPv2 tunnels and sessions here.
1380 *****************************************************************************/
1381
1382#ifdef CONFIG_PROC_FS
1383
1384struct pppol2tp_seq_data {
1385 struct seq_net_private p;
1386 unsigned long tkey; /* lookup key of current tunnel */
1387 unsigned long skey; /* lookup key of current session */
1388 struct l2tp_tunnel *tunnel;
1389 struct l2tp_session *session; /* NULL means get next tunnel */
1390};
1391
1392static void pppol2tp_next_tunnel(struct net *net, struct pppol2tp_seq_data *pd)
1393{
1394 /* Drop reference taken during previous invocation */
1395 if (pd->tunnel)
1396 l2tp_tunnel_put(pd->tunnel);
1397
1398 for (;;) {
1399 pd->tunnel = l2tp_tunnel_get_next(net, &pd->tkey);
1400 pd->tkey++;
1401
1402 /* Only accept L2TPv2 tunnels */
1403 if (!pd->tunnel || pd->tunnel->version == 2)
1404 return;
1405
1406 l2tp_tunnel_put(pd->tunnel);
1407 }
1408}
1409
1410static void pppol2tp_next_session(struct net *net, struct pppol2tp_seq_data *pd)
1411{
1412 /* Drop reference taken during previous invocation */
1413 if (pd->session)
1414 l2tp_session_put(pd->session);
1415
1416 pd->session = l2tp_session_get_next(net, pd->tunnel->sock,
1417 pd->tunnel->version,
1418 pd->tunnel->tunnel_id, &pd->skey);
1419 pd->skey++;
1420
1421 if (!pd->session) {
1422 pd->skey = 0;
1423 pppol2tp_next_tunnel(net, pd);
1424 }
1425}
1426
1427static void *pppol2tp_seq_start(struct seq_file *m, loff_t *offs)
1428{
1429 struct pppol2tp_seq_data *pd = SEQ_START_TOKEN;
1430 loff_t pos = *offs;
1431 struct net *net;
1432
1433 if (!pos)
1434 goto out;
1435
1436 if (WARN_ON(!m->private)) {
1437 pd = NULL;
1438 goto out;
1439 }
1440
1441 pd = m->private;
1442 net = seq_file_net(m);
1443
1444 if (!pd->tunnel)
1445 pppol2tp_next_tunnel(net, pd);
1446 else
1447 pppol2tp_next_session(net, pd);
1448
1449 /* NULL tunnel and session indicates end of list */
1450 if (!pd->tunnel && !pd->session)
1451 pd = NULL;
1452
1453out:
1454 return pd;
1455}
1456
1457static void *pppol2tp_seq_next(struct seq_file *m, void *v, loff_t *pos)
1458{
1459 (*pos)++;
1460 return NULL;
1461}
1462
1463static void pppol2tp_seq_stop(struct seq_file *p, void *v)
1464{
1465 struct pppol2tp_seq_data *pd = v;
1466
1467 if (!pd || pd == SEQ_START_TOKEN)
1468 return;
1469
1470 /* Drop reference taken by last invocation of pppol2tp_next_session()
1471 * or pppol2tp_next_tunnel().
1472 */
1473 if (pd->session) {
1474 l2tp_session_put(pd->session);
1475 pd->session = NULL;
1476 }
1477 if (pd->tunnel) {
1478 l2tp_tunnel_put(pd->tunnel);
1479 pd->tunnel = NULL;
1480 }
1481}
1482
1483static void pppol2tp_seq_tunnel_show(struct seq_file *m, void *v)
1484{
1485 struct l2tp_tunnel *tunnel = v;
1486
1487 seq_printf(m, "\nTUNNEL '%s', %c %d\n",
1488 tunnel->name,
1489 tunnel->sock ? 'Y' : 'N',
1490 refcount_read(&tunnel->ref_count) - 1);
1491 seq_printf(m, " %08x %ld/%ld/%ld %ld/%ld/%ld\n",
1492 0,
1493 atomic_long_read(&tunnel->stats.tx_packets),
1494 atomic_long_read(&tunnel->stats.tx_bytes),
1495 atomic_long_read(&tunnel->stats.tx_errors),
1496 atomic_long_read(&tunnel->stats.rx_packets),
1497 atomic_long_read(&tunnel->stats.rx_bytes),
1498 atomic_long_read(&tunnel->stats.rx_errors));
1499}
1500
1501static void pppol2tp_seq_session_show(struct seq_file *m, void *v)
1502{
1503 struct l2tp_session *session = v;
1504 struct l2tp_tunnel *tunnel = session->tunnel;
1505 unsigned char state;
1506 char user_data_ok;
1507 struct sock *sk;
1508 u32 ip = 0;
1509 u16 port = 0;
1510
1511 if (tunnel->sock) {
1512 struct inet_sock *inet = inet_sk(tunnel->sock);
1513
1514 ip = ntohl(inet->inet_saddr);
1515 port = ntohs(inet->inet_sport);
1516 }
1517
1518 rcu_read_lock();
1519 sk = pppol2tp_session_get_sock(session);
1520 if (sk) {
1521 state = sk->sk_state;
1522 user_data_ok = (session == sk->sk_user_data) ? 'Y' : 'N';
1523 } else {
1524 state = 0;
1525 user_data_ok = 'N';
1526 }
1527
1528 seq_printf(m, " SESSION '%s' %08X/%d %04X/%04X -> %04X/%04X %d %c\n",
1529 session->name, ip, port,
1530 tunnel->tunnel_id,
1531 session->session_id,
1532 tunnel->peer_tunnel_id,
1533 session->peer_session_id,
1534 state, user_data_ok);
1535 seq_printf(m, " 0/0/%c/%c/%s %08x %u\n",
1536 session->recv_seq ? 'R' : '-',
1537 session->send_seq ? 'S' : '-',
1538 session->lns_mode ? "LNS" : "LAC",
1539 0,
1540 jiffies_to_msecs(session->reorder_timeout));
1541 seq_printf(m, " %u/%u %ld/%ld/%ld %ld/%ld/%ld\n",
1542 session->nr, session->ns,
1543 atomic_long_read(&session->stats.tx_packets),
1544 atomic_long_read(&session->stats.tx_bytes),
1545 atomic_long_read(&session->stats.tx_errors),
1546 atomic_long_read(&session->stats.rx_packets),
1547 atomic_long_read(&session->stats.rx_bytes),
1548 atomic_long_read(&session->stats.rx_errors));
1549
1550 if (sk) {
1551 struct pppox_sock *po = pppox_sk(sk);
1552
1553 seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan));
1554 }
1555 rcu_read_unlock();
1556}
1557
1558static int pppol2tp_seq_show(struct seq_file *m, void *v)
1559{
1560 struct pppol2tp_seq_data *pd = v;
1561
1562 /* display header on line 1 */
1563 if (v == SEQ_START_TOKEN) {
1564 seq_puts(m, "PPPoL2TP driver info, " PPPOL2TP_DRV_VERSION "\n");
1565 seq_puts(m, "TUNNEL name, user-data-ok session-count\n");
1566 seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
1567 seq_puts(m, " SESSION name, addr/port src-tid/sid dest-tid/sid state user-data-ok\n");
1568 seq_puts(m, " mtu/mru/rcvseq/sendseq/lns debug reorderto\n");
1569 seq_puts(m, " nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
1570 goto out;
1571 }
1572
1573 if (!pd->session)
1574 pppol2tp_seq_tunnel_show(m, pd->tunnel);
1575 else
1576 pppol2tp_seq_session_show(m, pd->session);
1577
1578out:
1579 return 0;
1580}
1581
1582static const struct seq_operations pppol2tp_seq_ops = {
1583 .start = pppol2tp_seq_start,
1584 .next = pppol2tp_seq_next,
1585 .stop = pppol2tp_seq_stop,
1586 .show = pppol2tp_seq_show,
1587};
1588#endif /* CONFIG_PROC_FS */
1589
1590/*****************************************************************************
1591 * Network namespace
1592 *****************************************************************************/
1593
1594static __net_init int pppol2tp_init_net(struct net *net)
1595{
1596 struct proc_dir_entry *pde;
1597 int err = 0;
1598
1599 pde = proc_create_net("pppol2tp", 0444, net->proc_net,
1600 &pppol2tp_seq_ops, sizeof(struct pppol2tp_seq_data));
1601 if (!pde) {
1602 err = -ENOMEM;
1603 goto out;
1604 }
1605
1606out:
1607 return err;
1608}
1609
1610static __net_exit void pppol2tp_exit_net(struct net *net)
1611{
1612 remove_proc_entry("pppol2tp", net->proc_net);
1613}
1614
1615static struct pernet_operations pppol2tp_net_ops = {
1616 .init = pppol2tp_init_net,
1617 .exit = pppol2tp_exit_net,
1618};
1619
1620/*****************************************************************************
1621 * Init and cleanup
1622 *****************************************************************************/
1623
1624static const struct proto_ops pppol2tp_ops = {
1625 .family = AF_PPPOX,
1626 .owner = THIS_MODULE,
1627 .release = pppol2tp_release,
1628 .bind = sock_no_bind,
1629 .connect = pppol2tp_connect,
1630 .socketpair = sock_no_socketpair,
1631 .accept = sock_no_accept,
1632 .getname = pppol2tp_getname,
1633 .poll = datagram_poll,
1634 .listen = sock_no_listen,
1635 .shutdown = sock_no_shutdown,
1636 .setsockopt = pppol2tp_setsockopt,
1637 .getsockopt = pppol2tp_getsockopt,
1638 .sendmsg = pppol2tp_sendmsg,
1639 .recvmsg = pppol2tp_recvmsg,
1640 .mmap = sock_no_mmap,
1641 .ioctl = pppox_ioctl,
1642#ifdef CONFIG_COMPAT
1643 .compat_ioctl = pppox_compat_ioctl,
1644#endif
1645};
1646
1647static const struct pppox_proto pppol2tp_proto = {
1648 .create = pppol2tp_create,
1649 .ioctl = pppol2tp_ioctl,
1650 .owner = THIS_MODULE,
1651};
1652
1653#ifdef CONFIG_L2TP_V3
1654
1655static const struct l2tp_nl_cmd_ops pppol2tp_nl_cmd_ops = {
1656 .session_create = pppol2tp_session_create,
1657 .session_delete = l2tp_session_delete,
1658};
1659
1660#endif /* CONFIG_L2TP_V3 */
1661
1662static int __init pppol2tp_init(void)
1663{
1664 int err;
1665
1666 err = register_pernet_device(&pppol2tp_net_ops);
1667 if (err)
1668 goto out;
1669
1670 err = proto_register(&pppol2tp_sk_proto, 0);
1671 if (err)
1672 goto out_unregister_pppol2tp_pernet;
1673
1674 err = register_pppox_proto(PX_PROTO_OL2TP, &pppol2tp_proto);
1675 if (err)
1676 goto out_unregister_pppol2tp_proto;
1677
1678#ifdef CONFIG_L2TP_V3
1679 err = l2tp_nl_register_ops(L2TP_PWTYPE_PPP, &pppol2tp_nl_cmd_ops);
1680 if (err)
1681 goto out_unregister_pppox;
1682#endif
1683
1684 pr_info("PPPoL2TP kernel driver, %s\n", PPPOL2TP_DRV_VERSION);
1685
1686out:
1687 return err;
1688
1689#ifdef CONFIG_L2TP_V3
1690out_unregister_pppox:
1691 unregister_pppox_proto(PX_PROTO_OL2TP);
1692#endif
1693out_unregister_pppol2tp_proto:
1694 proto_unregister(&pppol2tp_sk_proto);
1695out_unregister_pppol2tp_pernet:
1696 unregister_pernet_device(&pppol2tp_net_ops);
1697 goto out;
1698}
1699
1700static void __exit pppol2tp_exit(void)
1701{
1702#ifdef CONFIG_L2TP_V3
1703 l2tp_nl_unregister_ops(L2TP_PWTYPE_PPP);
1704#endif
1705 unregister_pppox_proto(PX_PROTO_OL2TP);
1706 proto_unregister(&pppol2tp_sk_proto);
1707 unregister_pernet_device(&pppol2tp_net_ops);
1708}
1709
1710module_init(pppol2tp_init);
1711module_exit(pppol2tp_exit);
1712
1713MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
1714MODULE_DESCRIPTION("PPP over L2TP over UDP");
1715MODULE_LICENSE("GPL");
1716MODULE_VERSION(PPPOL2TP_DRV_VERSION);
1717MODULE_ALIAS_NET_PF_PROTO(PF_PPPOX, PX_PROTO_OL2TP);
1718MODULE_ALIAS_L2TP_PWTYPE(7);