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Subject: [PPPOL2TP] add missing sock_put() in pppol2tp_recv_dequeue()
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / net / pppol2tp.c
CommitLineData
3557baab
JC		 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: 1.0.0
8 *
9 * Authors: Martijn van Oosterhout <kleptog@svana.org>
10 * James Chapman (jchapman@katalix.com)
11 * Contributors:
12 * Michal Ostrowski <mostrows@speakeasy.net>
13 * Arnaldo Carvalho de Melo <acme@xconectiva.com.br>
14 * David S. Miller (davem@redhat.com)
15 *
16 * License:
17 * This program is free software; you can redistribute it and/or
18 * modify it under the terms of the GNU General Public License
19 * as published by the Free Software Foundation; either version
20 * 2 of the License, or (at your option) any later version.
21 *
22 */
23
24/* This driver handles only L2TP data frames; control frames are handled by a
25 * userspace application.
26 *
27 * To send data in an L2TP session, userspace opens a PPPoL2TP socket and
28 * attaches it to a bound UDP socket with local tunnel_id / session_id and
29 * peer tunnel_id / session_id set. Data can then be sent or received using
30 * regular socket sendmsg() / recvmsg() calls. Kernel parameters of the socket
31 * can be read or modified using ioctl() or [gs]etsockopt() calls.
32 *
33 * When a PPPoL2TP socket is connected with local and peer session_id values
34 * zero, the socket is treated as a special tunnel management socket.
35 *
36 * Here's example userspace code to create a socket for sending/receiving data
37 * over an L2TP session:-
38 *
39 * struct sockaddr_pppol2tp sax;
40 * int fd;
41 * int session_fd;
42 *
43 * fd = socket(AF_PPPOX, SOCK_DGRAM, PX_PROTO_OL2TP);
44 *
45 * sax.sa_family = AF_PPPOX;
46 * sax.sa_protocol = PX_PROTO_OL2TP;
47 * sax.pppol2tp.fd = tunnel_fd; // bound UDP socket
48 * sax.pppol2tp.addr.sin_addr.s_addr = addr->sin_addr.s_addr;
49 * sax.pppol2tp.addr.sin_port = addr->sin_port;
50 * sax.pppol2tp.addr.sin_family = AF_INET;
51 * sax.pppol2tp.s_tunnel = tunnel_id;
52 * sax.pppol2tp.s_session = session_id;
53 * sax.pppol2tp.d_tunnel = peer_tunnel_id;
54 * sax.pppol2tp.d_session = peer_session_id;
55 *
56 * session_fd = connect(fd, (struct sockaddr *)&sax, sizeof(sax));
57 *
58 * A pppd plugin that allows PPP traffic to be carried over L2TP using
59 * this driver is available from the OpenL2TP project at
60 * http://openl2tp.sourceforge.net.
61 */
62
63#include <linux/module.h>
64#include <linux/version.h>
65#include <linux/string.h>
66#include <linux/list.h>
67#include <asm/uaccess.h>
68
69#include <linux/kernel.h>
70#include <linux/spinlock.h>
71#include <linux/kthread.h>
72#include <linux/sched.h>
73#include <linux/slab.h>
74#include <linux/errno.h>
75#include <linux/jiffies.h>
76
77#include <linux/netdevice.h>
78#include <linux/net.h>
79#include <linux/inetdevice.h>
80#include <linux/skbuff.h>
81#include <linux/init.h>
82#include <linux/ip.h>
83#include <linux/udp.h>
84#include <linux/if_pppox.h>
85#include <linux/if_pppol2tp.h>
86#include <net/sock.h>
87#include <linux/ppp_channel.h>
88#include <linux/ppp_defs.h>
89#include <linux/if_ppp.h>
90#include <linux/file.h>
91#include <linux/hash.h>
92#include <linux/sort.h>
93#include <linux/proc_fs.h>
457c4cbc 94#include <net/net_namespace.h>
3557baab
JC		 95#include <net/dst.h>
96#include <net/ip.h>
97#include <net/udp.h>
98#include <net/xfrm.h>
99
100#include <asm/byteorder.h>
101#include <asm/atomic.h>
102
103
104#define PPPOL2TP_DRV_VERSION "V1.0"
105
106/* L2TP header constants */
107#define L2TP_HDRFLAG_T 0x8000
108#define L2TP_HDRFLAG_L 0x4000
109#define L2TP_HDRFLAG_S 0x0800
110#define L2TP_HDRFLAG_O 0x0200
111#define L2TP_HDRFLAG_P 0x0100
112
113#define L2TP_HDR_VER_MASK 0x000F
114#define L2TP_HDR_VER 0x0002
115
116/* Space for UDP, L2TP and PPP headers */
117#define PPPOL2TP_HEADER_OVERHEAD 40
118
119/* Just some random numbers */
120#define L2TP_TUNNEL_MAGIC 0x42114DDA
121#define L2TP_SESSION_MAGIC 0x0C04EB7D
122
123#define PPPOL2TP_HASH_BITS 4
124#define PPPOL2TP_HASH_SIZE (1 << PPPOL2TP_HASH_BITS)
125
126/* Default trace flags */
127#define PPPOL2TP_DEFAULT_DEBUG_FLAGS 0
128
129#define PRINTK(_mask, _type, _lvl, _fmt, args...) \
130 do { \
131 if ((_mask) & (_type)) \
132 printk(_lvl "PPPOL2TP: " _fmt, ##args); \
133 } while(0)
134
135/* Number of bytes to build transmit L2TP headers.
136 * Unfortunately the size is different depending on whether sequence numbers
137 * are enabled.
138 */
139#define PPPOL2TP_L2TP_HDR_SIZE_SEQ 10
140#define PPPOL2TP_L2TP_HDR_SIZE_NOSEQ 6
141
142struct pppol2tp_tunnel;
143
144/* Describes a session. It is the sk_user_data field in the PPPoL2TP
145 * socket. Contains information to determine incoming packets and transmit
146 * outgoing ones.
147 */
148struct pppol2tp_session
149{
150 int magic; /* should be
151 * L2TP_SESSION_MAGIC */
152 int owner; /* pid that opened the socket */
153
154 struct sock *sock; /* Pointer to the session
155 * PPPoX socket */
156 struct sock *tunnel_sock; /* Pointer to the tunnel UDP
157 * socket */
158
159 struct pppol2tp_addr tunnel_addr; /* Description of tunnel */
160
161 struct pppol2tp_tunnel *tunnel; /* back pointer to tunnel
162 * context */
163
164 char name[20]; /* "sess xxxxx/yyyyy", where
165 * x=tunnel_id, y=session_id */
166 int mtu;
167 int mru;
168 int flags; /* accessed by PPPIOCGFLAGS.
169 * Unused. */
170 unsigned recv_seq:1; /* expect receive packets with
171 * sequence numbers? */
172 unsigned send_seq:1; /* send packets with sequence
173 * numbers? */
174 unsigned lns_mode:1; /* behave as LNS? LAC enables
175 * sequence numbers under
176 * control of LNS. */
177 int debug; /* bitmask of debug message
178 * categories */
179 int reorder_timeout; /* configured reorder timeout
180 * (in jiffies) */
181 u16 nr; /* session NR state (receive) */
182 u16 ns; /* session NR state (send) */
183 struct sk_buff_head reorder_q; /* receive reorder queue */
184 struct pppol2tp_ioc_stats stats;
185 struct hlist_node hlist; /* Hash list node */
186};
187
188/* The sk_user_data field of the tunnel's UDP socket. It contains info to track
189 * all the associated sessions so incoming packets can be sorted out
190 */
191struct pppol2tp_tunnel
192{
193 int magic; /* Should be L2TP_TUNNEL_MAGIC */
194 rwlock_t hlist_lock; /* protect session_hlist */
195 struct hlist_head session_hlist[PPPOL2TP_HASH_SIZE];
196 /* hashed list of sessions,
197 * hashed by id */
198 int debug; /* bitmask of debug message
199 * categories */
200 char name[12]; /* "tunl xxxxx" */
201 struct pppol2tp_ioc_stats stats;
202
203 void (*old_sk_destruct)(struct sock *);
204
205 struct sock *sock; /* Parent socket */
206 struct list_head list; /* Keep a list of all open
207 * prepared sockets */
208
209 atomic_t ref_count;
210};
211
212/* Private data stored for received packets in the skb.
213 */
214struct pppol2tp_skb_cb {
215 u16 ns;
216 u16 nr;
217 u16 has_seq;
218 u16 length;
219 unsigned long expires;
220};
221
222#define PPPOL2TP_SKB_CB(skb) ((struct pppol2tp_skb_cb *) &skb->cb[sizeof(struct inet_skb_parm)])
223
224static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb);
225static void pppol2tp_tunnel_free(struct pppol2tp_tunnel *tunnel);
226
227static atomic_t pppol2tp_tunnel_count;
228static atomic_t pppol2tp_session_count;
229static struct ppp_channel_ops pppol2tp_chan_ops = { pppol2tp_xmit , NULL };
230static struct proto_ops pppol2tp_ops;
231static LIST_HEAD(pppol2tp_tunnel_list);
232static DEFINE_RWLOCK(pppol2tp_tunnel_list_lock);
233
234/* Helpers to obtain tunnel/session contexts from sockets.
235 */
236static inline struct pppol2tp_session *pppol2tp_sock_to_session(struct sock *sk)
237{
238 struct pppol2tp_session *session;
239
240 if (sk == NULL)
241 return NULL;
242
243 session = (struct pppol2tp_session *)(sk->sk_user_data);
244 if (session == NULL)
245 return NULL;
246
247 BUG_ON(session->magic != L2TP_SESSION_MAGIC);
248
249 return session;
250}
251
252static inline struct pppol2tp_tunnel *pppol2tp_sock_to_tunnel(struct sock *sk)
253{
254 struct pppol2tp_tunnel *tunnel;
255
256 if (sk == NULL)
257 return NULL;
258
259 tunnel = (struct pppol2tp_tunnel *)(sk->sk_user_data);
260 if (tunnel == NULL)
261 return NULL;
262
263 BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);
264
265 return tunnel;
266}
267
268/* Tunnel reference counts. Incremented per session that is added to
269 * the tunnel.
270 */
271static inline void pppol2tp_tunnel_inc_refcount(struct pppol2tp_tunnel *tunnel)
272{
273 atomic_inc(&tunnel->ref_count);
274}
275
276static inline void pppol2tp_tunnel_dec_refcount(struct pppol2tp_tunnel *tunnel)
277{
278 if (atomic_dec_and_test(&tunnel->ref_count))
279 pppol2tp_tunnel_free(tunnel);
280}
281
282/* Session hash list.
283 * The session_id SHOULD be random according to RFC2661, but several
284 * L2TP implementations (Cisco and Microsoft) use incrementing
285 * session_ids. So we do a real hash on the session_id, rather than a
286 * simple bitmask.
287 */
288static inline struct hlist_head *
289pppol2tp_session_id_hash(struct pppol2tp_tunnel *tunnel, u16 session_id)
290{
291 unsigned long hash_val = (unsigned long) session_id;
292 return &tunnel->session_hlist[hash_long(hash_val, PPPOL2TP_HASH_BITS)];
293}
294
295/* Lookup a session by id
296 */
297static struct pppol2tp_session *
298pppol2tp_session_find(struct pppol2tp_tunnel *tunnel, u16 session_id)
299{
300 struct hlist_head *session_list =
301 pppol2tp_session_id_hash(tunnel, session_id);
302 struct pppol2tp_session *session;
303 struct hlist_node *walk;
304
305 read_lock(&tunnel->hlist_lock);
306 hlist_for_each_entry(session, walk, session_list, hlist) {
307 if (session->tunnel_addr.s_session == session_id) {
308 read_unlock(&tunnel->hlist_lock);
309 return session;
310 }
311 }
312 read_unlock(&tunnel->hlist_lock);
313
314 return NULL;
315}
316
317/* Lookup a tunnel by id
318 */
319static struct pppol2tp_tunnel *pppol2tp_tunnel_find(u16 tunnel_id)
320{
321 struct pppol2tp_tunnel *tunnel = NULL;
322
323 read_lock(&pppol2tp_tunnel_list_lock);
324 list_for_each_entry(tunnel, &pppol2tp_tunnel_list, list) {
325 if (tunnel->stats.tunnel_id == tunnel_id) {
326 read_unlock(&pppol2tp_tunnel_list_lock);
327 return tunnel;
328 }
329 }
330 read_unlock(&pppol2tp_tunnel_list_lock);
331
332 return NULL;
333}
334
335/*****************************************************************************
336 * Receive data handling
337 *****************************************************************************/
338
339/* Queue a skb in order. We come here only if the skb has an L2TP sequence
340 * number.
341 */
342static void pppol2tp_recv_queue_skb(struct pppol2tp_session *session, struct sk_buff *skb)
343{
344 struct sk_buff *skbp;
345 u16 ns = PPPOL2TP_SKB_CB(skb)->ns;
346
347 spin_lock(&session->reorder_q.lock);
348 skb_queue_walk(&session->reorder_q, skbp) {
349 if (PPPOL2TP_SKB_CB(skbp)->ns > ns) {
350 __skb_insert(skb, skbp->prev, skbp, &session->reorder_q);
351 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
352 "%s: pkt %hu, inserted before %hu, reorder_q len=%d\n",
353 session->name, ns, PPPOL2TP_SKB_CB(skbp)->ns,
354 skb_queue_len(&session->reorder_q));
355 session->stats.rx_oos_packets++;
356 goto out;
357 }
358 }
359
360 __skb_queue_tail(&session->reorder_q, skb);
361
362out:
363 spin_unlock(&session->reorder_q.lock);
364}
365
366/* Dequeue a single skb.
367 */
368static void pppol2tp_recv_dequeue_skb(struct pppol2tp_session *session, struct sk_buff *skb)
369{
370 struct pppol2tp_tunnel *tunnel = session->tunnel;
371 int length = PPPOL2TP_SKB_CB(skb)->length;
372 struct sock *session_sock = NULL;
373
374 /* We're about to requeue the skb, so unlink it and return resources
375 * to its current owner (a socket receive buffer).
376 */
377 skb_unlink(skb, &session->reorder_q);
378 skb_orphan(skb);
379
380 tunnel->stats.rx_packets++;
381 tunnel->stats.rx_bytes += length;
382 session->stats.rx_packets++;
383 session->stats.rx_bytes += length;
384
385 if (PPPOL2TP_SKB_CB(skb)->has_seq) {
386 /* Bump our Nr */
387 session->nr++;
388 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
389 "%s: updated nr to %hu\n", session->name, session->nr);
390 }
391
392 /* If the socket is bound, send it in to PPP's input queue. Otherwise
393 * queue it on the session socket.
394 */
395 session_sock = session->sock;
396 if (session_sock->sk_state & PPPOX_BOUND) {
397 struct pppox_sock *po;
398 PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
399 "%s: recv %d byte data frame, passing to ppp\n",
400 session->name, length);
401
402 /* We need to forget all info related to the L2TP packet
403 * gathered in the skb as we are going to reuse the same
404 * skb for the inner packet.
405 * Namely we need to:
406 * - reset xfrm (IPSec) information as it applies to
407 * the outer L2TP packet and not to the inner one
408 * - release the dst to force a route lookup on the inner
409 * IP packet since skb->dst currently points to the dst
410 * of the UDP tunnel
411 * - reset netfilter information as it doesn't apply
412 * to the inner packet either
413 */
414 secpath_reset(skb);
415 dst_release(skb->dst);
416 skb->dst = NULL;
417 nf_reset(skb);
418
419 po = pppox_sk(session_sock);
420 ppp_input(&po->chan, skb);
421 } else {
422 PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_INFO,
423 "%s: socket not bound\n", session->name);
424
425 /* Not bound. Nothing we can do, so discard. */
426 session->stats.rx_errors++;
427 kfree_skb(skb);
428 }
429
430 sock_put(session->sock);
431}
432
433/* Dequeue skbs from the session's reorder_q, subject to packet order.
434 * Skbs that have been in the queue for too long are simply discarded.
435 */
436static void pppol2tp_recv_dequeue(struct pppol2tp_session *session)
437{
438 struct sk_buff *skb;
439 struct sk_buff *tmp;
440
441 /* If the pkt at the head of the queue has the nr that we
442 * expect to send up next, dequeue it and any other
443 * in-sequence packets behind it.
444 */
445 spin_lock(&session->reorder_q.lock);
446 skb_queue_walk_safe(&session->reorder_q, skb, tmp) {
447 if (time_after(jiffies, PPPOL2TP_SKB_CB(skb)->expires)) {
448 session->stats.rx_seq_discards++;
449 session->stats.rx_errors++;
450 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
451 "%s: oos pkt %hu len %d discarded (too old), "
452 "waiting for %hu, reorder_q_len=%d\n",
453 session->name, PPPOL2TP_SKB_CB(skb)->ns,
454 PPPOL2TP_SKB_CB(skb)->length, session->nr,
455 skb_queue_len(&session->reorder_q));
456 __skb_unlink(skb, &session->reorder_q);
457 kfree_skb(skb);
c8fff1cf 458 sock_put(session->sock);
3557baab
JC		 459 continue;
460 }
461
462 if (PPPOL2TP_SKB_CB(skb)->has_seq) {
463 if (PPPOL2TP_SKB_CB(skb)->ns != session->nr) {
464 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
465 "%s: holding oos pkt %hu len %d, "
466 "waiting for %hu, reorder_q_len=%d\n",
467 session->name, PPPOL2TP_SKB_CB(skb)->ns,
468 PPPOL2TP_SKB_CB(skb)->length, session->nr,
469 skb_queue_len(&session->reorder_q));
470 goto out;
471 }
472 }
473 spin_unlock(&session->reorder_q.lock);
474 pppol2tp_recv_dequeue_skb(session, skb);
475 spin_lock(&session->reorder_q.lock);
476 }
477
478out:
479 spin_unlock(&session->reorder_q.lock);
480}
481
482/* Internal receive frame. Do the real work of receiving an L2TP data frame
483 * here. The skb is not on a list when we get here.
484 * Returns 0 if the packet was a data packet and was successfully passed on.
485 * Returns 1 if the packet was not a good data packet and could not be
486 * forwarded. All such packets are passed up to userspace to deal with.
487 */
488static int pppol2tp_recv_core(struct sock *sock, struct sk_buff *skb)
489{
490 struct pppol2tp_session *session = NULL;
491 struct pppol2tp_tunnel *tunnel;
91781004 492 unsigned char *ptr, *optr;
3557baab
JC		 493 u16 hdrflags;
494 u16 tunnel_id, session_id;
495 int length;
7a70e39b 496 int offset;
3557baab
JC		 497
498 tunnel = pppol2tp_sock_to_tunnel(sock);
499 if (tunnel == NULL)
91781004 500 goto no_tunnel;
3557baab 501
7a70e39b
HX		 502 /* UDP always verifies the packet length. */
503 __skb_pull(skb, sizeof(struct udphdr));
504
3557baab 505 /* Short packet? */
7a70e39b 506 if (!pskb_may_pull(skb, 12)) {
3557baab
JC		 507 PRINTK(tunnel->debug, PPPOL2TP_MSG_DATA, KERN_INFO,
508 "%s: recv short packet (len=%d)\n", tunnel->name, skb->len);
509 goto error;
510 }
511
512 /* Point to L2TP header */
91781004 513 optr = ptr = skb->data;
3557baab
JC		 514
515 /* Get L2TP header flags */
516 hdrflags = ntohs(*(__be16*)ptr);
517
518 /* Trace packet contents, if enabled */
519 if (tunnel->debug & PPPOL2TP_MSG_DATA) {
7a70e39b
HX		 520 length = min(16u, skb->len);
521 if (!pskb_may_pull(skb, length))
522 goto error;
523
3557baab
JC		 524 printk(KERN_DEBUG "%s: recv: ", tunnel->name);
525
7a70e39b
HX		 526 offset = 0;
527 do {
528 printk(" %02X", ptr[offset]);
529 } while (++offset < length);
530
3557baab
JC		 531 printk("\n");
532 }
533
534 /* Get length of L2TP packet */
7a70e39b 535 length = skb->len;
3557baab
JC		 536
537 /* If type is control packet, it is handled by userspace. */
538 if (hdrflags & L2TP_HDRFLAG_T) {
539 PRINTK(tunnel->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
540 "%s: recv control packet, len=%d\n", tunnel->name, length);
541 goto error;
542 }
543
544 /* Skip flags */
545 ptr += 2;
546
547 /* If length is present, skip it */
548 if (hdrflags & L2TP_HDRFLAG_L)
549 ptr += 2;
550
551 /* Extract tunnel and session ID */
552 tunnel_id = ntohs(*(__be16 *) ptr);
553 ptr += 2;
554 session_id = ntohs(*(__be16 *) ptr);
555 ptr += 2;
556
557 /* Find the session context */
558 session = pppol2tp_session_find(tunnel, session_id);
559 if (!session) {
560 /* Not found? Pass to userspace to deal with */
561 PRINTK(tunnel->debug, PPPOL2TP_MSG_DATA, KERN_INFO,
562 "%s: no socket found (%hu/%hu). Passing up.\n",
563 tunnel->name, tunnel_id, session_id);
564 goto error;
565 }
566 sock_hold(session->sock);
567
568 /* The ref count on the socket was increased by the above call since
569 * we now hold a pointer to the session. Take care to do sock_put()
570 * when exiting this function from now on...
571 */
572
573 /* Handle the optional sequence numbers. If we are the LAC,
574 * enable/disable sequence numbers under the control of the LNS. If
575 * no sequence numbers present but we were expecting them, discard
576 * frame.
577 */
578 if (hdrflags & L2TP_HDRFLAG_S) {
579 u16 ns, nr;
580 ns = ntohs(*(__be16 *) ptr);
581 ptr += 2;
582 nr = ntohs(*(__be16 *) ptr);
583 ptr += 2;
584
585 /* Received a packet with sequence numbers. If we're the LNS,
586 * check if we sre sending sequence numbers and if not,
587 * configure it so.
588 */
589 if ((!session->lns_mode) && (!session->send_seq)) {
590 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_INFO,
591 "%s: requested to enable seq numbers by LNS\n",
592 session->name);
593 session->send_seq = -1;
594 }
595
596 /* Store L2TP info in the skb */
597 PPPOL2TP_SKB_CB(skb)->ns = ns;
598 PPPOL2TP_SKB_CB(skb)->nr = nr;
599 PPPOL2TP_SKB_CB(skb)->has_seq = 1;
600
601 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
602 "%s: recv data ns=%hu, nr=%hu, session nr=%hu\n",
603 session->name, ns, nr, session->nr);
604 } else {
605 /* No sequence numbers.
606 * If user has configured mandatory sequence numbers, discard.
607 */
608 if (session->recv_seq) {
609 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_WARNING,
610 "%s: recv data has no seq numbers when required. "
611 "Discarding\n", session->name);
612 session->stats.rx_seq_discards++;
3557baab
JC		 613 goto discard;
614 }
615
616 /* If we're the LAC and we're sending sequence numbers, the
617 * LNS has requested that we no longer send sequence numbers.
618 * If we're the LNS and we're sending sequence numbers, the
619 * LAC is broken. Discard the frame.
620 */
621 if ((!session->lns_mode) && (session->send_seq)) {
622 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_INFO,
623 "%s: requested to disable seq numbers by LNS\n",
624 session->name);
625 session->send_seq = 0;
626 } else if (session->send_seq) {
627 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_WARNING,
628 "%s: recv data has no seq numbers when required. "
629 "Discarding\n", session->name);
630 session->stats.rx_seq_discards++;
3557baab
JC		 631 goto discard;
632 }
633
634 /* Store L2TP info in the skb */
635 PPPOL2TP_SKB_CB(skb)->has_seq = 0;
636 }
637
638 /* If offset bit set, skip it. */
7a70e39b
HX		 639 if (hdrflags & L2TP_HDRFLAG_O) {
640 offset = ntohs(*(__be16 *)ptr);
91781004 641 ptr += 2 + offset;
7a70e39b 642 }
3557baab 643
91781004
JC		 644 offset = ptr - optr;
645 if (!pskb_may_pull(skb, offset))
646 goto discard;
647
648 __skb_pull(skb, offset);
3557baab
JC		 649
650 /* Skip PPP header, if present. In testing, Microsoft L2TP clients
651 * don't send the PPP header (PPP header compression enabled), but
652 * other clients can include the header. So we cope with both cases
653 * here. The PPP header is always FF03 when using L2TP.
654 *
655 * Note that skb->data[] isn't dereferenced from a u16 ptr here since
656 * the field may be unaligned.
657 */
91781004
JC		 658 if (!pskb_may_pull(skb, 2))
659 goto discard;
660
3557baab
JC		 661 if ((skb->data[0] == 0xff) && (skb->data[1] == 0x03))
662 skb_pull(skb, 2);
663
664 /* Prepare skb for adding to the session's reorder_q. Hold
665 * packets for max reorder_timeout or 1 second if not
666 * reordering.
667 */
668 PPPOL2TP_SKB_CB(skb)->length = length;
669 PPPOL2TP_SKB_CB(skb)->expires = jiffies +
670 (session->reorder_timeout ? session->reorder_timeout : HZ);
671
672 /* Add packet to the session's receive queue. Reordering is done here, if
673 * enabled. Saved L2TP protocol info is stored in skb->sb[].
674 */
675 if (PPPOL2TP_SKB_CB(skb)->has_seq) {
676 if (session->reorder_timeout != 0) {
677 /* Packet reordering enabled. Add skb to session's
678 * reorder queue, in order of ns.
679 */
680 pppol2tp_recv_queue_skb(session, skb);
681 } else {
682 /* Packet reordering disabled. Discard out-of-sequence
683 * packets
684 */
685 if (PPPOL2TP_SKB_CB(skb)->ns != session->nr) {
686 session->stats.rx_seq_discards++;
3557baab
JC		 687 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
688 "%s: oos pkt %hu len %d discarded, "
689 "waiting for %hu, reorder_q_len=%d\n",
690 session->name, PPPOL2TP_SKB_CB(skb)->ns,
691 PPPOL2TP_SKB_CB(skb)->length, session->nr,
692 skb_queue_len(&session->reorder_q));
693 goto discard;
694 }
695 skb_queue_tail(&session->reorder_q, skb);
696 }
697 } else {
698 /* No sequence numbers. Add the skb to the tail of the
699 * reorder queue. This ensures that it will be
700 * delivered after all previous sequenced skbs.
701 */
702 skb_queue_tail(&session->reorder_q, skb);
703 }
704
705 /* Try to dequeue as many skbs from reorder_q as we can. */
706 pppol2tp_recv_dequeue(session);
707
708 return 0;
709
710discard:
7a70e39b 711 session->stats.rx_errors++;
3557baab
JC		 712 kfree_skb(skb);
713 sock_put(session->sock);
714
715 return 0;
716
717error:
91781004
JC		 718 /* Put UDP header back */
719 __skb_push(skb, sizeof(struct udphdr));
720
721no_tunnel:
3557baab
JC		 722 return 1;
723}
724
725/* UDP encapsulation receive handler. See net/ipv4/udp.c.
726 * Return codes:
727 * 0 : success.
728 * <0: error
729 * >0: skb should be passed up to userspace as UDP.
730 */
731static int pppol2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
732{
733 struct pppol2tp_tunnel *tunnel;
734
735 tunnel = pppol2tp_sock_to_tunnel(sk);
736 if (tunnel == NULL)
737 goto pass_up;
738
739 PRINTK(tunnel->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
740 "%s: received %d bytes\n", tunnel->name, skb->len);
741
742 if (pppol2tp_recv_core(sk, skb))
743 goto pass_up;
744
745 return 0;
746
747pass_up:
748 return 1;
749}
750
751/* Receive message. This is the recvmsg for the PPPoL2TP socket.
752 */
753static int pppol2tp_recvmsg(struct kiocb *iocb, struct socket *sock,
754 struct msghdr *msg, size_t len,
755 int flags)
756{
757 int err;
758 struct sk_buff *skb;
759 struct sock *sk = sock->sk;
760
761 err = -EIO;
762 if (sk->sk_state & PPPOX_BOUND)
763 goto end;
764
765 msg->msg_namelen = 0;
766
767 err = 0;
768 skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
769 flags & MSG_DONTWAIT, &err);
770 if (skb) {
771 err = memcpy_toiovec(msg->msg_iov, (unsigned char *) skb->data,
772 skb->len);
773 if (err < 0)
774 goto do_skb_free;
775 err = skb->len;
776 }
777do_skb_free:
778 kfree_skb(skb);
779end:
780 return err;
781}
782
783/************************************************************************
784 * Transmit handling
785 ***********************************************************************/
786
787/* Tell how big L2TP headers are for a particular session. This
788 * depends on whether sequence numbers are being used.
789 */
790static inline int pppol2tp_l2tp_header_len(struct pppol2tp_session *session)
791{
792 if (session->send_seq)
793 return PPPOL2TP_L2TP_HDR_SIZE_SEQ;
794
795 return PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
796}
797
798/* Build an L2TP header for the session into the buffer provided.
799 */
800static void pppol2tp_build_l2tp_header(struct pppol2tp_session *session,
801 void *buf)
802{
803 __be16 *bufp = buf;
804 u16 flags = L2TP_HDR_VER;
805
806 if (session->send_seq)
807 flags |= L2TP_HDRFLAG_S;
808
809 /* Setup L2TP header.
810 * FIXME: Can this ever be unaligned? Is direct dereferencing of
811 * 16-bit header fields safe here for all architectures?
812 */
813 *bufp++ = htons(flags);
814 *bufp++ = htons(session->tunnel_addr.d_tunnel);
815 *bufp++ = htons(session->tunnel_addr.d_session);
816 if (session->send_seq) {
817 *bufp++ = htons(session->ns);
818 *bufp++ = 0;
819 session->ns++;
820 PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
821 "%s: updated ns to %hu\n", session->name, session->ns);
822 }
823}
824
825/* This is the sendmsg for the PPPoL2TP pppol2tp_session socket. We come here
826 * when a user application does a sendmsg() on the session socket. L2TP and
827 * PPP headers must be inserted into the user's data.
828 */
829static int pppol2tp_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
830 size_t total_len)
831{
832 static const unsigned char ppph[2] = { 0xff, 0x03 };
833 struct sock *sk = sock->sk;
834 struct inet_sock *inet;
835 __wsum csum = 0;
836 struct sk_buff *skb;
837 int error;
838 int hdr_len;
839 struct pppol2tp_session *session;
840 struct pppol2tp_tunnel *tunnel;
841 struct udphdr *uh;
7d4372b5 842 unsigned int len;
3557baab
JC		 843
844 error = -ENOTCONN;
845 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
846 goto error;
847
848 /* Get session and tunnel contexts */
849 error = -EBADF;
850 session = pppol2tp_sock_to_session(sk);
851 if (session == NULL)
852 goto error;
853
854 tunnel = pppol2tp_sock_to_tunnel(session->tunnel_sock);
855 if (tunnel == NULL)
856 goto error;
857
858 /* What header length is configured for this session? */
859 hdr_len = pppol2tp_l2tp_header_len(session);
860
861 /* Allocate a socket buffer */
862 error = -ENOMEM;
863 skb = sock_wmalloc(sk, NET_SKB_PAD + sizeof(struct iphdr) +
864 sizeof(struct udphdr) + hdr_len +
865 sizeof(ppph) + total_len,
866 0, GFP_KERNEL);
867 if (!skb)
868 goto error;
869
870 /* Reserve space for headers. */
871 skb_reserve(skb, NET_SKB_PAD);
872 skb_reset_network_header(skb);
873 skb_reserve(skb, sizeof(struct iphdr));
874 skb_reset_transport_header(skb);
875
876 /* Build UDP header */
877 inet = inet_sk(session->tunnel_sock);
878 uh = (struct udphdr *) skb->data;
879 uh->source = inet->sport;
880 uh->dest = inet->dport;
881 uh->len = htons(hdr_len + sizeof(ppph) + total_len);
882 uh->check = 0;
883 skb_put(skb, sizeof(struct udphdr));
884
885 /* Build L2TP header */
886 pppol2tp_build_l2tp_header(session, skb->data);
887 skb_put(skb, hdr_len);
888
889 /* Add PPP header */
890 skb->data[0] = ppph[0];
891 skb->data[1] = ppph[1];
892 skb_put(skb, 2);
893
894 /* Copy user data into skb */
895 error = memcpy_fromiovec(skb->data, m->msg_iov, total_len);
896 if (error < 0) {
897 kfree_skb(skb);
898 goto error;
899 }
900 skb_put(skb, total_len);
901
902 /* Calculate UDP checksum if configured to do so */
903 if (session->tunnel_sock->sk_no_check != UDP_CSUM_NOXMIT)
904 csum = udp_csum_outgoing(sk, skb);
905
906 /* Debug */
907 if (session->send_seq)
908 PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
38d15b65 909 "%s: send %Zd bytes, ns=%hu\n", session->name,
3557baab
JC		 910 total_len, session->ns - 1);
911 else
912 PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
38d15b65 913 "%s: send %Zd bytes\n", session->name, total_len);
3557baab
JC		 914
915 if (session->debug & PPPOL2TP_MSG_DATA) {
916 int i;
917 unsigned char *datap = skb->data;
918
919 printk(KERN_DEBUG "%s: xmit:", session->name);
920 for (i = 0; i < total_len; i++) {
921 printk(" %02X", *datap++);
922 if (i == 15) {
923 printk(" ...");
924 break;
925 }
926 }
927 printk("\n");
928 }
929
930 /* Queue the packet to IP for output */
7d4372b5 931 len = skb->len;
3557baab
JC		 932 error = ip_queue_xmit(skb, 1);
933
934 /* Update stats */
935 if (error >= 0) {
936 tunnel->stats.tx_packets++;
7d4372b5 937 tunnel->stats.tx_bytes += len;
3557baab 938 session->stats.tx_packets++;
7d4372b5 939 session->stats.tx_bytes += len;
3557baab
JC		 940 } else {
941 tunnel->stats.tx_errors++;
942 session->stats.tx_errors++;
943 }
944
945error:
946 return error;
947}
948
949/* Transmit function called by generic PPP driver. Sends PPP frame
950 * over PPPoL2TP socket.
951 *
952 * This is almost the same as pppol2tp_sendmsg(), but rather than
953 * being called with a msghdr from userspace, it is called with a skb
954 * from the kernel.
955 *
956 * The supplied skb from ppp doesn't have enough headroom for the
957 * insertion of L2TP, UDP and IP headers so we need to allocate more
958 * headroom in the skb. This will create a cloned skb. But we must be
959 * careful in the error case because the caller will expect to free
960 * the skb it supplied, not our cloned skb. So we take care to always
961 * leave the original skb unfreed if we return an error.
962 */
963static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
964{
965 static const u8 ppph[2] = { 0xff, 0x03 };
966 struct sock *sk = (struct sock *) chan->private;
967 struct sock *sk_tun;
968 int hdr_len;
969 struct pppol2tp_session *session;
970 struct pppol2tp_tunnel *tunnel;
971 int rc;
972 int headroom;
973 int data_len = skb->len;
974 struct inet_sock *inet;
975 __wsum csum = 0;
3557baab 976 struct udphdr *uh;
7d4372b5 977 unsigned int len;
3557baab
JC		 978
979 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
980 goto abort;
981
982 /* Get session and tunnel contexts from the socket */
983 session = pppol2tp_sock_to_session(sk);
984 if (session == NULL)
985 goto abort;
986
987 sk_tun = session->tunnel_sock;
988 if (sk_tun == NULL)
989 goto abort;
990 tunnel = pppol2tp_sock_to_tunnel(sk_tun);
991 if (tunnel == NULL)
992 goto abort;
993
994 /* What header length is configured for this session? */
995 hdr_len = pppol2tp_l2tp_header_len(session);
996
997 /* Check that there's enough headroom in the skb to insert IP,
998 * UDP and L2TP and PPP headers. If not enough, expand it to
999 * make room. Note that a new skb (or a clone) is
1000 * allocated. If we return an error from this point on, make
1001 * sure we free the new skb but do not free the original skb
1002 * since that is done by the caller for the error case.
1003 */
1004 headroom = NET_SKB_PAD + sizeof(struct iphdr) +
1005 sizeof(struct udphdr) + hdr_len + sizeof(ppph);
f3d5e3a4
HX		 1006 if (skb_cow_head(skb, headroom))
1007 goto abort;
3557baab
JC		 1008
1009 /* Setup PPP header */
f3d5e3a4
HX		 1010 __skb_push(skb, sizeof(ppph));
1011 skb->data[0] = ppph[0];
1012 skb->data[1] = ppph[1];
3557baab
JC		 1013
1014 /* Setup L2TP header */
f3d5e3a4 1015 pppol2tp_build_l2tp_header(session, __skb_push(skb, hdr_len));
3557baab
JC		 1016
1017 /* Setup UDP header */
1018 inet = inet_sk(sk_tun);
f3d5e3a4
HX		 1019 __skb_push(skb, sizeof(*uh));
1020 skb_reset_transport_header(skb);
1021 uh = udp_hdr(skb);
3557baab
JC		 1022 uh->source = inet->sport;
1023 uh->dest = inet->dport;
1024 uh->len = htons(sizeof(struct udphdr) + hdr_len + sizeof(ppph) + data_len);
1025 uh->check = 0;
1026
f3d5e3a4 1027 /* *BROKEN* Calculate UDP checksum if configured to do so */
3557baab 1028 if (sk_tun->sk_no_check != UDP_CSUM_NOXMIT)
f3d5e3a4 1029 csum = udp_csum_outgoing(sk_tun, skb);
3557baab
JC		 1030
1031 /* Debug */
1032 if (session->send_seq)
1033 PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
1034 "%s: send %d bytes, ns=%hu\n", session->name,
1035 data_len, session->ns - 1);
1036 else
1037 PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
1038 "%s: send %d bytes\n", session->name, data_len);
1039
1040 if (session->debug & PPPOL2TP_MSG_DATA) {
1041 int i;
f3d5e3a4 1042 unsigned char *datap = skb->data;
3557baab
JC		 1043
1044 printk(KERN_DEBUG "%s: xmit:", session->name);
1045 for (i = 0; i < data_len; i++) {
1046 printk(" %02X", *datap++);
1047 if (i == 31) {
1048 printk(" ...");
1049 break;
1050 }
1051 }
1052 printk("\n");
1053 }
1054
f3d5e3a4
HX		 1055 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1056 IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED |
1057 IPSKB_REROUTED);
1058 nf_reset(skb);
f77ae939 1059
3557baab 1060 /* Get routing info from the tunnel socket */
f3d5e3a4
HX		 1061 dst_release(skb->dst);
1062 skb->dst = sk_dst_get(sk_tun);
91781004
JC		 1063 skb_orphan(skb);
1064 skb->sk = sk_tun;
3557baab
JC		 1065
1066 /* Queue the packet to IP for output */
f3d5e3a4
HX		 1067 len = skb->len;
1068 rc = ip_queue_xmit(skb, 1);
3557baab
JC		 1069
1070 /* Update stats */
1071 if (rc >= 0) {
1072 tunnel->stats.tx_packets++;
7d4372b5 1073 tunnel->stats.tx_bytes += len;
3557baab 1074 session->stats.tx_packets++;
7d4372b5 1075 session->stats.tx_bytes += len;
3557baab
JC		 1076 } else {
1077 tunnel->stats.tx_errors++;
1078 session->stats.tx_errors++;
1079 }
1080
3557baab
JC		 1081 return 1;
1082
3557baab 1083abort:
f3d5e3a4
HX		 1084 /* Free the original skb */
1085 kfree_skb(skb);
1086 return 1;
3557baab
JC		 1087}
1088
1089/*****************************************************************************
1090 * Session (and tunnel control) socket create/destroy.
1091 *****************************************************************************/
1092
1093/* When the tunnel UDP socket is closed, all the attached sockets need to go
1094 * too.
1095 */
1096static void pppol2tp_tunnel_closeall(struct pppol2tp_tunnel *tunnel)
1097{
1098 int hash;
1099 struct hlist_node *walk;
1100 struct hlist_node *tmp;
1101 struct pppol2tp_session *session;
1102 struct sock *sk;
1103
1104 if (tunnel == NULL)
1105 BUG();
1106
1107 PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1108 "%s: closing all sessions...\n", tunnel->name);
1109
1110 write_lock(&tunnel->hlist_lock);
1111 for (hash = 0; hash < PPPOL2TP_HASH_SIZE; hash++) {
1112again:
1113 hlist_for_each_safe(walk, tmp, &tunnel->session_hlist[hash]) {
1114 session = hlist_entry(walk, struct pppol2tp_session, hlist);
1115
1116 sk = session->sock;
1117
1118 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1119 "%s: closing session\n", session->name);
1120
1121 hlist_del_init(&session->hlist);
1122
1123 /* Since we should hold the sock lock while
1124 * doing any unbinding, we need to release the
1125 * lock we're holding before taking that lock.
1126 * Hold a reference to the sock so it doesn't
1127 * disappear as we're jumping between locks.
1128 */
1129 sock_hold(sk);
1130 write_unlock(&tunnel->hlist_lock);
1131 lock_sock(sk);
1132
1133 if (sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND)) {
1134 pppox_unbind_sock(sk);
1135 sk->sk_state = PPPOX_DEAD;
1136 sk->sk_state_change(sk);
1137 }
1138
1139 /* Purge any queued data */
1140 skb_queue_purge(&sk->sk_receive_queue);
1141 skb_queue_purge(&sk->sk_write_queue);
1142 skb_queue_purge(&session->reorder_q);
1143
1144 release_sock(sk);
1145 sock_put(sk);
1146
1147 /* Now restart from the beginning of this hash
1148 * chain. We always remove a session from the
1149 * list so we are guaranteed to make forward
1150 * progress.
1151 */
1152 write_lock(&tunnel->hlist_lock);
1153 goto again;
1154 }
1155 }
1156 write_unlock(&tunnel->hlist_lock);
1157}
1158
1159/* Really kill the tunnel.
1160 * Come here only when all sessions have been cleared from the tunnel.
1161 */
1162static void pppol2tp_tunnel_free(struct pppol2tp_tunnel *tunnel)
1163{
1164 /* Remove from socket list */
1165 write_lock(&pppol2tp_tunnel_list_lock);
1166 list_del_init(&tunnel->list);
1167 write_unlock(&pppol2tp_tunnel_list_lock);
1168
1169 atomic_dec(&pppol2tp_tunnel_count);
1170 kfree(tunnel);
1171}
1172
1173/* Tunnel UDP socket destruct hook.
1174 * The tunnel context is deleted only when all session sockets have been
1175 * closed.
1176 */
1177static void pppol2tp_tunnel_destruct(struct sock *sk)
1178{
1179 struct pppol2tp_tunnel *tunnel;
1180
1181 tunnel = pppol2tp_sock_to_tunnel(sk);
1182 if (tunnel == NULL)
1183 goto end;
1184
1185 PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1186 "%s: closing...\n", tunnel->name);
1187
1188 /* Close all sessions */
1189 pppol2tp_tunnel_closeall(tunnel);
1190
1191 /* No longer an encapsulation socket. See net/ipv4/udp.c */
1192 (udp_sk(sk))->encap_type = 0;
1193 (udp_sk(sk))->encap_rcv = NULL;
1194
1195 /* Remove hooks into tunnel socket */
1196 tunnel->sock = NULL;
1197 sk->sk_destruct = tunnel->old_sk_destruct;
1198 sk->sk_user_data = NULL;
1199
1200 /* Call original (UDP) socket descructor */
1201 if (sk->sk_destruct != NULL)
1202 (*sk->sk_destruct)(sk);
1203
1204 pppol2tp_tunnel_dec_refcount(tunnel);
1205
1206end:
1207 return;
1208}
1209
1210/* Really kill the session socket. (Called from sock_put() if
1211 * refcnt == 0.)
1212 */
1213static void pppol2tp_session_destruct(struct sock *sk)
1214{
1215 struct pppol2tp_session *session = NULL;
1216
1217 if (sk->sk_user_data != NULL) {
1218 struct pppol2tp_tunnel *tunnel;
1219
1220 session = pppol2tp_sock_to_session(sk);
1221 if (session == NULL)
1222 goto out;
1223
1224 /* Don't use pppol2tp_sock_to_tunnel() here to
1225 * get the tunnel context because the tunnel
1226 * socket might have already been closed (its
1227 * sk->sk_user_data will be NULL) so use the
1228 * session's private tunnel ptr instead.
1229 */
1230 tunnel = session->tunnel;
1231 if (tunnel != NULL) {
1232 BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);
1233
1234 /* If session_id is zero, this is a null
1235 * session context, which was created for a
1236 * socket that is being used only to manage
1237 * tunnels.
1238 */
1239 if (session->tunnel_addr.s_session != 0) {
1240 /* Delete the session socket from the
1241 * hash
1242 */
1243 write_lock(&tunnel->hlist_lock);
1244 hlist_del_init(&session->hlist);
1245 write_unlock(&tunnel->hlist_lock);
1246
1247 atomic_dec(&pppol2tp_session_count);
1248 }
1249
1250 /* This will delete the tunnel context if this
1251 * is the last session on the tunnel.
1252 */
1253 session->tunnel = NULL;
1254 session->tunnel_sock = NULL;
1255 pppol2tp_tunnel_dec_refcount(tunnel);
1256 }
1257 }
1258
1259 kfree(session);
1260out:
1261 return;
1262}
1263
1264/* Called when the PPPoX socket (session) is closed.
1265 */
1266static int pppol2tp_release(struct socket *sock)
1267{
1268 struct sock *sk = sock->sk;
1269 int error;
1270
1271 if (!sk)
1272 return 0;
1273
1274 error = -EBADF;
1275 lock_sock(sk);
1276 if (sock_flag(sk, SOCK_DEAD) != 0)
1277 goto error;
1278
1279 pppox_unbind_sock(sk);
1280
1281 /* Signal the death of the socket. */
1282 sk->sk_state = PPPOX_DEAD;
1283 sock_orphan(sk);
1284 sock->sk = NULL;
1285
1286 /* Purge any queued data */
1287 skb_queue_purge(&sk->sk_receive_queue);
1288 skb_queue_purge(&sk->sk_write_queue);
1289
1290 release_sock(sk);
1291
1292 /* This will delete the session context via
1293 * pppol2tp_session_destruct() if the socket's refcnt drops to
1294 * zero.
1295 */
1296 sock_put(sk);
1297
1298 return 0;
1299
1300error:
1301 release_sock(sk);
1302 return error;
1303}
1304
1305/* Internal function to prepare a tunnel (UDP) socket to have PPPoX
1306 * sockets attached to it.
1307 */
1308static struct sock *pppol2tp_prepare_tunnel_socket(int fd, u16 tunnel_id,
1309 int *error)
1310{
1311 int err;
1312 struct socket *sock = NULL;
1313 struct sock *sk;
1314 struct pppol2tp_tunnel *tunnel;
1315 struct sock *ret = NULL;
1316
1317 /* Get the tunnel UDP socket from the fd, which was opened by
1318 * the userspace L2TP daemon.
1319 */
1320 err = -EBADF;
1321 sock = sockfd_lookup(fd, &err);
1322 if (!sock) {
1323 PRINTK(-1, PPPOL2TP_MSG_CONTROL, KERN_ERR,
1324 "tunl %hu: sockfd_lookup(fd=%d) returned %d\n",
1325 tunnel_id, fd, err);
1326 goto err;
1327 }
1328
a14d6abc
HX		 1329 sk = sock->sk;
1330
3557baab 1331 /* Quick sanity checks */
a14d6abc
HX		 1332 err = -EPROTONOSUPPORT;
1333 if (sk->sk_protocol != IPPROTO_UDP) {
3557baab 1334 PRINTK(-1, PPPOL2TP_MSG_CONTROL, KERN_ERR,
a14d6abc
HX		 1335 "tunl %hu: fd %d wrong protocol, got %d, expected %d\n",
1336 tunnel_id, fd, sk->sk_protocol, IPPROTO_UDP);
3557baab
JC		 1337 goto err;
1338 }
1339 err = -EAFNOSUPPORT;
1340 if (sock->ops->family != AF_INET) {
1341 PRINTK(-1, PPPOL2TP_MSG_CONTROL, KERN_ERR,
1342 "tunl %hu: fd %d wrong family, got %d, expected %d\n",
1343 tunnel_id, fd, sock->ops->family, AF_INET);
1344 goto err;
1345 }
1346
1347 err = -ENOTCONN;
3557baab
JC		 1348
1349 /* Check if this socket has already been prepped */
1350 tunnel = (struct pppol2tp_tunnel *)sk->sk_user_data;
1351 if (tunnel != NULL) {
1352 /* User-data field already set */
1353 err = -EBUSY;
1354 BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);
1355
1356 /* This socket has already been prepped */
1357 ret = tunnel->sock;
1358 goto out;
1359 }
1360
1361 /* This socket is available and needs prepping. Create a new tunnel
1362 * context and init it.
1363 */
1364 sk->sk_user_data = tunnel = kzalloc(sizeof(struct pppol2tp_tunnel), GFP_KERNEL);
1365 if (sk->sk_user_data == NULL) {
1366 err = -ENOMEM;
1367 goto err;
1368 }
1369
1370 tunnel->magic = L2TP_TUNNEL_MAGIC;
1371 sprintf(&tunnel->name[0], "tunl %hu", tunnel_id);
1372
1373 tunnel->stats.tunnel_id = tunnel_id;
1374 tunnel->debug = PPPOL2TP_DEFAULT_DEBUG_FLAGS;
1375
1376 /* Hook on the tunnel socket destructor so that we can cleanup
1377 * if the tunnel socket goes away.
1378 */
1379 tunnel->old_sk_destruct = sk->sk_destruct;
1380 sk->sk_destruct = &pppol2tp_tunnel_destruct;
1381
1382 tunnel->sock = sk;
1383 sk->sk_allocation = GFP_ATOMIC;
1384
1385 /* Misc init */
1386 rwlock_init(&tunnel->hlist_lock);
1387
1388 /* Add tunnel to our list */
1389 INIT_LIST_HEAD(&tunnel->list);
1390 write_lock(&pppol2tp_tunnel_list_lock);
1391 list_add(&tunnel->list, &pppol2tp_tunnel_list);
1392 write_unlock(&pppol2tp_tunnel_list_lock);
1393 atomic_inc(&pppol2tp_tunnel_count);
1394
1395 /* Bump the reference count. The tunnel context is deleted
1396 * only when this drops to zero.
1397 */
1398 pppol2tp_tunnel_inc_refcount(tunnel);
1399
1400 /* Mark socket as an encapsulation socket. See net/ipv4/udp.c */
1401 (udp_sk(sk))->encap_type = UDP_ENCAP_L2TPINUDP;
1402 (udp_sk(sk))->encap_rcv = pppol2tp_udp_encap_recv;
1403
1404 ret = tunnel->sock;
1405
1406 *error = 0;
1407out:
1408 if (sock)
1409 sockfd_put(sock);
1410
1411 return ret;
1412
1413err:
1414 *error = err;
1415 goto out;
1416}
1417
1418static struct proto pppol2tp_sk_proto = {
1419 .name = "PPPOL2TP",
1420 .owner = THIS_MODULE,
1421 .obj_size = sizeof(struct pppox_sock),
1422};
1423
1424/* socket() handler. Initialize a new struct sock.
1425 */
1b8d7ae4 1426static int pppol2tp_create(struct net *net, struct socket *sock)
3557baab
JC		 1427{
1428 int error = -ENOMEM;
1429 struct sock *sk;
1430
6257ff21 1431 sk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, &pppol2tp_sk_proto);
3557baab
JC		 1432 if (!sk)
1433 goto out;
1434
1435 sock_init_data(sock, sk);
1436
1437 sock->state = SS_UNCONNECTED;
1438 sock->ops = &pppol2tp_ops;
1439
1440 sk->sk_backlog_rcv = pppol2tp_recv_core;
1441 sk->sk_protocol = PX_PROTO_OL2TP;
1442 sk->sk_family = PF_PPPOX;
1443 sk->sk_state = PPPOX_NONE;
1444 sk->sk_type = SOCK_STREAM;
1445 sk->sk_destruct = pppol2tp_session_destruct;
1446
1447 error = 0;
1448
1449out:
1450 return error;
1451}
1452
1453/* connect() handler. Attach a PPPoX socket to a tunnel UDP socket
1454 */
1455static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr,
1456 int sockaddr_len, int flags)
1457{
1458 struct sock *sk = sock->sk;
1459 struct sockaddr_pppol2tp *sp = (struct sockaddr_pppol2tp *) uservaddr;
1460 struct pppox_sock *po = pppox_sk(sk);
1461 struct sock *tunnel_sock = NULL;
1462 struct pppol2tp_session *session = NULL;
1463 struct pppol2tp_tunnel *tunnel;
1464 struct dst_entry *dst;
1465 int error = 0;
1466
1467 lock_sock(sk);
1468
1469 error = -EINVAL;
1470 if (sp->sa_protocol != PX_PROTO_OL2TP)
1471 goto end;
1472
1473 /* Check for already bound sockets */
1474 error = -EBUSY;
1475 if (sk->sk_state & PPPOX_CONNECTED)
1476 goto end;
1477
1478 /* We don't supporting rebinding anyway */
1479 error = -EALREADY;
1480 if (sk->sk_user_data)
1481 goto end; /* socket is already attached */
1482
1483 /* Don't bind if s_tunnel is 0 */
1484 error = -EINVAL;
1485 if (sp->pppol2tp.s_tunnel == 0)
1486 goto end;
1487
1488 /* Special case: prepare tunnel socket if s_session and
1489 * d_session is 0. Otherwise look up tunnel using supplied
1490 * tunnel id.
1491 */
1492 if ((sp->pppol2tp.s_session == 0) && (sp->pppol2tp.d_session == 0)) {
1493 tunnel_sock = pppol2tp_prepare_tunnel_socket(sp->pppol2tp.fd,
1494 sp->pppol2tp.s_tunnel,
1495 &error);
1496 if (tunnel_sock == NULL)
1497 goto end;
1498
1499 tunnel = tunnel_sock->sk_user_data;
1500 } else {
1501 tunnel = pppol2tp_tunnel_find(sp->pppol2tp.s_tunnel);
1502
1503 /* Error if we can't find the tunnel */
1504 error = -ENOENT;
1505 if (tunnel == NULL)
1506 goto end;
1507
1508 tunnel_sock = tunnel->sock;
1509 }
1510
1511 /* Check that this session doesn't already exist */
1512 error = -EEXIST;
1513 session = pppol2tp_session_find(tunnel, sp->pppol2tp.s_session);
1514 if (session != NULL)
1515 goto end;
1516
1517 /* Allocate and initialize a new session context. */
1518 session = kzalloc(sizeof(struct pppol2tp_session), GFP_KERNEL);
1519 if (session == NULL) {
1520 error = -ENOMEM;
1521 goto end;
1522 }
1523
1524 skb_queue_head_init(&session->reorder_q);
1525
1526 session->magic = L2TP_SESSION_MAGIC;
1527 session->owner = current->pid;
1528 session->sock = sk;
1529 session->tunnel = tunnel;
1530 session->tunnel_sock = tunnel_sock;
1531 session->tunnel_addr = sp->pppol2tp;
1532 sprintf(&session->name[0], "sess %hu/%hu",
1533 session->tunnel_addr.s_tunnel,
1534 session->tunnel_addr.s_session);
1535
1536 session->stats.tunnel_id = session->tunnel_addr.s_tunnel;
1537 session->stats.session_id = session->tunnel_addr.s_session;
1538
1539 INIT_HLIST_NODE(&session->hlist);
1540
1541 /* Inherit debug options from tunnel */
1542 session->debug = tunnel->debug;
1543
1544 /* Default MTU must allow space for UDP/L2TP/PPP
1545 * headers.
1546 */
1547 session->mtu = session->mru = 1500 - PPPOL2TP_HEADER_OVERHEAD;
1548
1549 /* If PMTU discovery was enabled, use the MTU that was discovered */
1550 dst = sk_dst_get(sk);
1551 if (dst != NULL) {
1552 u32 pmtu = dst_mtu(__sk_dst_get(sk));
1553 if (pmtu != 0)
1554 session->mtu = session->mru = pmtu -
1555 PPPOL2TP_HEADER_OVERHEAD;
1556 dst_release(dst);
1557 }
1558
1559 /* Special case: if source & dest session_id == 0x0000, this socket is
1560 * being created to manage the tunnel. Don't add the session to the
1561 * session hash list, just set up the internal context for use by
1562 * ioctl() and sockopt() handlers.
1563 */
1564 if ((session->tunnel_addr.s_session == 0) &&
1565 (session->tunnel_addr.d_session == 0)) {
1566 error = 0;
1567 sk->sk_user_data = session;
1568 goto out_no_ppp;
1569 }
1570
1571 /* Get tunnel context from the tunnel socket */
1572 tunnel = pppol2tp_sock_to_tunnel(tunnel_sock);
1573 if (tunnel == NULL) {
1574 error = -EBADF;
1575 goto end;
1576 }
1577
1578 /* Right now, because we don't have a way to push the incoming skb's
1579 * straight through the UDP layer, the only header we need to worry
1580 * about is the L2TP header. This size is different depending on
1581 * whether sequence numbers are enabled for the data channel.
1582 */
1583 po->chan.hdrlen = PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
1584
1585 po->chan.private = sk;
1586 po->chan.ops = &pppol2tp_chan_ops;
1587 po->chan.mtu = session->mtu;
1588
1589 error = ppp_register_channel(&po->chan);
1590 if (error)
1591 goto end;
1592
1593 /* This is how we get the session context from the socket. */
1594 sk->sk_user_data = session;
1595
1596 /* Add session to the tunnel's hash list */
1597 write_lock(&tunnel->hlist_lock);
1598 hlist_add_head(&session->hlist,
1599 pppol2tp_session_id_hash(tunnel,
1600 session->tunnel_addr.s_session));
1601 write_unlock(&tunnel->hlist_lock);
1602
1603 atomic_inc(&pppol2tp_session_count);
1604
1605out_no_ppp:
1606 pppol2tp_tunnel_inc_refcount(tunnel);
1607 sk->sk_state = PPPOX_CONNECTED;
1608 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1609 "%s: created\n", session->name);
1610
1611end:
1612 release_sock(sk);
1613
1614 if (error != 0)
1615 PRINTK(session ? session->debug : -1, PPPOL2TP_MSG_CONTROL, KERN_WARNING,
1616 "%s: connect failed: %d\n", session->name, error);
1617
1618 return error;
1619}
1620
1621/* getname() support.
1622 */
1623static int pppol2tp_getname(struct socket *sock, struct sockaddr *uaddr,
1624 int *usockaddr_len, int peer)
1625{
1626 int len = sizeof(struct sockaddr_pppol2tp);
1627 struct sockaddr_pppol2tp sp;
1628 int error = 0;
1629 struct pppol2tp_session *session;
1630
1631 error = -ENOTCONN;
1632 if (sock->sk->sk_state != PPPOX_CONNECTED)
1633 goto end;
1634
1635 session = pppol2tp_sock_to_session(sock->sk);
1636 if (session == NULL) {
1637 error = -EBADF;
1638 goto end;
1639 }
1640
1641 sp.sa_family = AF_PPPOX;
1642 sp.sa_protocol = PX_PROTO_OL2TP;
1643 memcpy(&sp.pppol2tp, &session->tunnel_addr,
1644 sizeof(struct pppol2tp_addr));
1645
1646 memcpy(uaddr, &sp, len);
1647
1648 *usockaddr_len = len;
1649
1650 error = 0;
1651
1652end:
1653 return error;
1654}
1655
1656/****************************************************************************
1657 * ioctl() handlers.
1658 *
1659 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
1660 * sockets. However, in order to control kernel tunnel features, we allow
1661 * userspace to create a special "tunnel" PPPoX socket which is used for
1662 * control only. Tunnel PPPoX sockets have session_id == 0 and simply allow
1663 * the user application to issue L2TP setsockopt(), getsockopt() and ioctl()
1664 * calls.
1665 ****************************************************************************/
1666
1667/* Session ioctl helper.
1668 */
1669static int pppol2tp_session_ioctl(struct pppol2tp_session *session,
1670 unsigned int cmd, unsigned long arg)
1671{
1672 struct ifreq ifr;
1673 int err = 0;
1674 struct sock *sk = session->sock;
1675 int val = (int) arg;
1676
1677 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_DEBUG,
1678 "%s: pppol2tp_session_ioctl(cmd=%#x, arg=%#lx)\n",
1679 session->name, cmd, arg);
1680
1681 sock_hold(sk);
1682
1683 switch (cmd) {
1684 case SIOCGIFMTU:
1685 err = -ENXIO;
1686 if (!(sk->sk_state & PPPOX_CONNECTED))
1687 break;
1688
1689 err = -EFAULT;
1690 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq)))
1691 break;
1692 ifr.ifr_mtu = session->mtu;
1693 if (copy_to_user((void __user *) arg, &ifr, sizeof(struct ifreq)))
1694 break;
1695
1696 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1697 "%s: get mtu=%d\n", session->name, session->mtu);
1698 err = 0;
1699 break;
1700
1701 case SIOCSIFMTU:
1702 err = -ENXIO;
1703 if (!(sk->sk_state & PPPOX_CONNECTED))
1704 break;
1705
1706 err = -EFAULT;
1707 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq)))
1708 break;
1709
1710 session->mtu = ifr.ifr_mtu;
1711
1712 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1713 "%s: set mtu=%d\n", session->name, session->mtu);
1714 err = 0;
1715 break;
1716
1717 case PPPIOCGMRU:
1718 err = -ENXIO;
1719 if (!(sk->sk_state & PPPOX_CONNECTED))
1720 break;
1721
1722 err = -EFAULT;
1723 if (put_user(session->mru, (int __user *) arg))
1724 break;
1725
1726 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1727 "%s: get mru=%d\n", session->name, session->mru);
1728 err = 0;
1729 break;
1730
1731 case PPPIOCSMRU:
1732 err = -ENXIO;
1733 if (!(sk->sk_state & PPPOX_CONNECTED))
1734 break;
1735
1736 err = -EFAULT;
1737 if (get_user(val,(int __user *) arg))
1738 break;
1739
1740 session->mru = val;
1741 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1742 "%s: set mru=%d\n", session->name, session->mru);
1743 err = 0;
1744 break;
1745
1746 case PPPIOCGFLAGS:
1747 err = -EFAULT;
1748 if (put_user(session->flags, (int __user *) arg))
1749 break;
1750
1751 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1752 "%s: get flags=%d\n", session->name, session->flags);
1753 err = 0;
1754 break;
1755
1756 case PPPIOCSFLAGS:
1757 err = -EFAULT;
1758 if (get_user(val, (int __user *) arg))
1759 break;
1760 session->flags = val;
1761 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1762 "%s: set flags=%d\n", session->name, session->flags);
1763 err = 0;
1764 break;
1765
1766 case PPPIOCGL2TPSTATS:
1767 err = -ENXIO;
1768 if (!(sk->sk_state & PPPOX_CONNECTED))
1769 break;
1770
1771 if (copy_to_user((void __user *) arg, &session->stats,
1772 sizeof(session->stats)))
1773 break;
1774 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1775 "%s: get L2TP stats\n", session->name);
1776 err = 0;
1777 break;
1778
1779 default:
1780 err = -ENOSYS;
1781 break;
1782 }
1783
1784 sock_put(sk);
1785
1786 return err;
1787}
1788
1789/* Tunnel ioctl helper.
1790 *
1791 * Note the special handling for PPPIOCGL2TPSTATS below. If the ioctl data
1792 * specifies a session_id, the session ioctl handler is called. This allows an
1793 * application to retrieve session stats via a tunnel socket.
1794 */
1795static int pppol2tp_tunnel_ioctl(struct pppol2tp_tunnel *tunnel,
1796 unsigned int cmd, unsigned long arg)
1797{
1798 int err = 0;
1799 struct sock *sk = tunnel->sock;
1800 struct pppol2tp_ioc_stats stats_req;
1801
1802 PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_DEBUG,
1803 "%s: pppol2tp_tunnel_ioctl(cmd=%#x, arg=%#lx)\n", tunnel->name,
1804 cmd, arg);
1805
1806 sock_hold(sk);
1807
1808 switch (cmd) {
1809 case PPPIOCGL2TPSTATS:
1810 err = -ENXIO;
1811 if (!(sk->sk_state & PPPOX_CONNECTED))
1812 break;
1813
1814 if (copy_from_user(&stats_req, (void __user *) arg,
1815 sizeof(stats_req))) {
1816 err = -EFAULT;
1817 break;
1818 }
1819 if (stats_req.session_id != 0) {
1820 /* resend to session ioctl handler */
1821 struct pppol2tp_session *session =
1822 pppol2tp_session_find(tunnel, stats_req.session_id);
1823 if (session != NULL)
1824 err = pppol2tp_session_ioctl(session, cmd, arg);
1825 else
1826 err = -EBADR;
1827 break;
1828 }
1829#ifdef CONFIG_XFRM
1830 tunnel->stats.using_ipsec = (sk->sk_policy[0] || sk->sk_policy[1]) ? 1 : 0;
1831#endif
1832 if (copy_to_user((void __user *) arg, &tunnel->stats,
1833 sizeof(tunnel->stats))) {
1834 err = -EFAULT;
1835 break;
1836 }
1837 PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1838 "%s: get L2TP stats\n", tunnel->name);
1839 err = 0;
1840 break;
1841
1842 default:
1843 err = -ENOSYS;
1844 break;
1845 }
1846
1847 sock_put(sk);
1848
1849 return err;
1850}
1851
1852/* Main ioctl() handler.
1853 * Dispatch to tunnel or session helpers depending on the socket.
1854 */
1855static int pppol2tp_ioctl(struct socket *sock, unsigned int cmd,
1856 unsigned long arg)
1857{
1858 struct sock *sk = sock->sk;
1859 struct pppol2tp_session *session;
1860 struct pppol2tp_tunnel *tunnel;
1861 int err;
1862
1863 if (!sk)
1864 return 0;
1865
1866 err = -EBADF;
1867 if (sock_flag(sk, SOCK_DEAD) != 0)
1868 goto end;
1869
1870 err = -ENOTCONN;
1871 if ((sk->sk_user_data == NULL) ||
1872 (!(sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND))))
1873 goto end;
1874
1875 /* Get session context from the socket */
1876 err = -EBADF;
1877 session = pppol2tp_sock_to_session(sk);
1878 if (session == NULL)
1879 goto end;
1880
1881 /* Special case: if session's session_id is zero, treat ioctl as a
1882 * tunnel ioctl
1883 */
1884 if ((session->tunnel_addr.s_session == 0) &&
1885 (session->tunnel_addr.d_session == 0)) {
1886 err = -EBADF;
1887 tunnel = pppol2tp_sock_to_tunnel(session->tunnel_sock);
1888 if (tunnel == NULL)
1889 goto end;
1890
1891 err = pppol2tp_tunnel_ioctl(tunnel, cmd, arg);
1892 goto end;
1893 }
1894
1895 err = pppol2tp_session_ioctl(session, cmd, arg);
1896
1897end:
1898 return err;
1899}
1900
1901/*****************************************************************************
1902 * setsockopt() / getsockopt() support.
1903 *
1904 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
1905 * sockets. In order to control kernel tunnel features, we allow userspace to
1906 * create a special "tunnel" PPPoX socket which is used for control only.
1907 * Tunnel PPPoX sockets have session_id == 0 and simply allow the user
1908 * application to issue L2TP setsockopt(), getsockopt() and ioctl() calls.
1909 *****************************************************************************/
1910
1911/* Tunnel setsockopt() helper.
1912 */
1913static int pppol2tp_tunnel_setsockopt(struct sock *sk,
1914 struct pppol2tp_tunnel *tunnel,
1915 int optname, int val)
1916{
1917 int err = 0;
1918
1919 switch (optname) {
1920 case PPPOL2TP_SO_DEBUG:
1921 tunnel->debug = val;
1922 PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1923 "%s: set debug=%x\n", tunnel->name, tunnel->debug);
1924 break;
1925
1926 default:
1927 err = -ENOPROTOOPT;
1928 break;
1929 }
1930
1931 return err;
1932}
1933
1934/* Session setsockopt helper.
1935 */
1936static int pppol2tp_session_setsockopt(struct sock *sk,
1937 struct pppol2tp_session *session,
1938 int optname, int val)
1939{
1940 int err = 0;
1941
1942 switch (optname) {
1943 case PPPOL2TP_SO_RECVSEQ:
1944 if ((val != 0) && (val != 1)) {
1945 err = -EINVAL;
1946 break;
1947 }
1948 session->recv_seq = val ? -1 : 0;
1949 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1950 "%s: set recv_seq=%d\n", session->name,
1951 session->recv_seq);
1952 break;
1953
1954 case PPPOL2TP_SO_SENDSEQ:
1955 if ((val != 0) && (val != 1)) {
1956 err = -EINVAL;
1957 break;
1958 }
1959 session->send_seq = val ? -1 : 0;
1960 {
1961 struct sock *ssk = session->sock;
1962 struct pppox_sock *po = pppox_sk(ssk);
1963 po->chan.hdrlen = val ? PPPOL2TP_L2TP_HDR_SIZE_SEQ :
1964 PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
1965 }
1966 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1967 "%s: set send_seq=%d\n", session->name, session->send_seq);
1968 break;
1969
1970 case PPPOL2TP_SO_LNSMODE:
1971 if ((val != 0) && (val != 1)) {
1972 err = -EINVAL;
1973 break;
1974 }
1975 session->lns_mode = val ? -1 : 0;
1976 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1977 "%s: set lns_mode=%d\n", session->name,
1978 session->lns_mode);
1979 break;
1980
1981 case PPPOL2TP_SO_DEBUG:
1982 session->debug = val;
1983 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1984 "%s: set debug=%x\n", session->name, session->debug);
1985 break;
1986
1987 case PPPOL2TP_SO_REORDERTO:
1988 session->reorder_timeout = msecs_to_jiffies(val);
1989 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
1990 "%s: set reorder_timeout=%d\n", session->name,
1991 session->reorder_timeout);
1992 break;
1993
1994 default:
1995 err = -ENOPROTOOPT;
1996 break;
1997 }
1998
1999 return err;
2000}
2001
2002/* Main setsockopt() entry point.
2003 * Does API checks, then calls either the tunnel or session setsockopt
2004 * handler, according to whether the PPPoL2TP socket is a for a regular
2005 * session or the special tunnel type.
2006 */
2007static int pppol2tp_setsockopt(struct socket *sock, int level, int optname,
2008 char __user *optval, int optlen)
2009{
2010 struct sock *sk = sock->sk;
2011 struct pppol2tp_session *session = sk->sk_user_data;
2012 struct pppol2tp_tunnel *tunnel;
2013 int val;
2014 int err;
2015
2016 if (level != SOL_PPPOL2TP)
2017 return udp_prot.setsockopt(sk, level, optname, optval, optlen);
2018
2019 if (optlen < sizeof(int))
2020 return -EINVAL;
2021
2022 if (get_user(val, (int __user *)optval))
2023 return -EFAULT;
2024
2025 err = -ENOTCONN;
2026 if (sk->sk_user_data == NULL)
2027 goto end;
2028
2029 /* Get session context from the socket */
2030 err = -EBADF;
2031 session = pppol2tp_sock_to_session(sk);
2032 if (session == NULL)
2033 goto end;
2034
2035 /* Special case: if session_id == 0x0000, treat as operation on tunnel
2036 */
2037 if ((session->tunnel_addr.s_session == 0) &&
2038 (session->tunnel_addr.d_session == 0)) {
2039 err = -EBADF;
2040 tunnel = pppol2tp_sock_to_tunnel(session->tunnel_sock);
2041 if (tunnel == NULL)
2042 goto end;
2043
2044 err = pppol2tp_tunnel_setsockopt(sk, tunnel, optname, val);
2045 } else
2046 err = pppol2tp_session_setsockopt(sk, session, optname, val);
2047
2048 err = 0;
2049
2050end:
2051 return err;
2052}
2053
2054/* Tunnel getsockopt helper. Called with sock locked.
2055 */
2056static int pppol2tp_tunnel_getsockopt(struct sock *sk,
2057 struct pppol2tp_tunnel *tunnel,
af3b162a 2058 int optname, int *val)
3557baab
JC		 2059{
2060 int err = 0;
2061
2062 switch (optname) {
2063 case PPPOL2TP_SO_DEBUG:
2064 *val = tunnel->debug;
2065 PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2066 "%s: get debug=%x\n", tunnel->name, tunnel->debug);
2067 break;
2068
2069 default:
2070 err = -ENOPROTOOPT;
2071 break;
2072 }
2073
2074 return err;
2075}
2076
2077/* Session getsockopt helper. Called with sock locked.
2078 */
2079static int pppol2tp_session_getsockopt(struct sock *sk,
2080 struct pppol2tp_session *session,
af3b162a 2081 int optname, int *val)
3557baab
JC		 2082{
2083 int err = 0;
2084
2085 switch (optname) {
2086 case PPPOL2TP_SO_RECVSEQ:
2087 *val = session->recv_seq;
2088 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2089 "%s: get recv_seq=%d\n", session->name, *val);
2090 break;
2091
2092 case PPPOL2TP_SO_SENDSEQ:
2093 *val = session->send_seq;
2094 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2095 "%s: get send_seq=%d\n", session->name, *val);
2096 break;
2097
2098 case PPPOL2TP_SO_LNSMODE:
2099 *val = session->lns_mode;
2100 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2101 "%s: get lns_mode=%d\n", session->name, *val);
2102 break;
2103
2104 case PPPOL2TP_SO_DEBUG:
2105 *val = session->debug;
2106 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2107 "%s: get debug=%d\n", session->name, *val);
2108 break;
2109
2110 case PPPOL2TP_SO_REORDERTO:
2111 *val = (int) jiffies_to_msecs(session->reorder_timeout);
2112 PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
2113 "%s: get reorder_timeout=%d\n", session->name, *val);
2114 break;
2115
2116 default:
2117 err = -ENOPROTOOPT;
2118 }
2119
2120 return err;
2121}
2122
2123/* Main getsockopt() entry point.
2124 * Does API checks, then calls either the tunnel or session getsockopt
2125 * handler, according to whether the PPPoX socket is a for a regular session
2126 * or the special tunnel type.
2127 */
2128static int pppol2tp_getsockopt(struct socket *sock, int level,
2129 int optname, char __user *optval, int __user *optlen)
2130{
2131 struct sock *sk = sock->sk;
2132 struct pppol2tp_session *session = sk->sk_user_data;
2133 struct pppol2tp_tunnel *tunnel;
2134 int val, len;
2135 int err;
2136
2137 if (level != SOL_PPPOL2TP)
2138 return udp_prot.getsockopt(sk, level, optname, optval, optlen);
2139
2140 if (get_user(len, (int __user *) optlen))
2141 return -EFAULT;
2142
2143 len = min_t(unsigned int, len, sizeof(int));
2144
2145 if (len < 0)
2146 return -EINVAL;
2147
2148 err = -ENOTCONN;
2149 if (sk->sk_user_data == NULL)
2150 goto end;
2151
2152 /* Get the session context */
2153 err = -EBADF;
2154 session = pppol2tp_sock_to_session(sk);
2155 if (session == NULL)
2156 goto end;
2157
2158 /* Special case: if session_id == 0x0000, treat as operation on tunnel */
2159 if ((session->tunnel_addr.s_session == 0) &&
2160 (session->tunnel_addr.d_session == 0)) {
2161 err = -EBADF;
2162 tunnel = pppol2tp_sock_to_tunnel(session->tunnel_sock);
2163 if (tunnel == NULL)
2164 goto end;
2165
2166 err = pppol2tp_tunnel_getsockopt(sk, tunnel, optname, &val);
2167 } else
2168 err = pppol2tp_session_getsockopt(sk, session, optname, &val);
2169
2170 err = -EFAULT;
2171 if (put_user(len, (int __user *) optlen))
2172 goto end;
2173
2174 if (copy_to_user((void __user *) optval, &val, len))
2175 goto end;
2176
2177 err = 0;
2178end:
2179 return err;
2180}
2181
2182/*****************************************************************************
2183 * /proc filesystem for debug
2184 *****************************************************************************/
2185
2186#ifdef CONFIG_PROC_FS
2187
2188#include <linux/seq_file.h>
2189
2190struct pppol2tp_seq_data {
2191 struct pppol2tp_tunnel *tunnel; /* current tunnel */
2192 struct pppol2tp_session *session; /* NULL means get first session in tunnel */
2193};
2194
2195static struct pppol2tp_session *next_session(struct pppol2tp_tunnel *tunnel, struct pppol2tp_session *curr)
2196{
2197 struct pppol2tp_session *session = NULL;
2198 struct hlist_node *walk;
2199 int found = 0;
2200 int next = 0;
2201 int i;
2202
2203 read_lock(&tunnel->hlist_lock);
2204 for (i = 0; i < PPPOL2TP_HASH_SIZE; i++) {
2205 hlist_for_each_entry(session, walk, &tunnel->session_hlist[i], hlist) {
2206 if (curr == NULL) {
2207 found = 1;
2208 goto out;
2209 }
2210 if (session == curr) {
2211 next = 1;
2212 continue;
2213 }
2214 if (next) {
2215 found = 1;
2216 goto out;
2217 }
2218 }
2219 }
2220out:
2221 read_unlock(&tunnel->hlist_lock);
2222 if (!found)
2223 session = NULL;
2224
2225 return session;
2226}
2227
2228static struct pppol2tp_tunnel *next_tunnel(struct pppol2tp_tunnel *curr)
2229{
2230 struct pppol2tp_tunnel *tunnel = NULL;
2231
2232 read_lock(&pppol2tp_tunnel_list_lock);
2233 if (list_is_last(&curr->list, &pppol2tp_tunnel_list)) {
2234 goto out;
2235 }
2236 tunnel = list_entry(curr->list.next, struct pppol2tp_tunnel, list);
2237out:
2238 read_unlock(&pppol2tp_tunnel_list_lock);
2239
2240 return tunnel;
2241}
2242
2243static void *pppol2tp_seq_start(struct seq_file *m, loff_t *offs)
2244{
2245 struct pppol2tp_seq_data *pd = SEQ_START_TOKEN;
2246 loff_t pos = *offs;
2247
2248 if (!pos)
2249 goto out;
2250
2251 BUG_ON(m->private == NULL);
2252 pd = m->private;
2253
2254 if (pd->tunnel == NULL) {
2255 if (!list_empty(&pppol2tp_tunnel_list))
2256 pd->tunnel = list_entry(pppol2tp_tunnel_list.next, struct pppol2tp_tunnel, list);
2257 } else {
2258 pd->session = next_session(pd->tunnel, pd->session);
2259 if (pd->session == NULL) {
2260 pd->tunnel = next_tunnel(pd->tunnel);
2261 }
2262 }
2263
2264 /* NULL tunnel and session indicates end of list */
2265 if ((pd->tunnel == NULL) && (pd->session == NULL))
2266 pd = NULL;
2267
2268out:
2269 return pd;
2270}
2271
2272static void *pppol2tp_seq_next(struct seq_file *m, void *v, loff_t *pos)
2273{
2274 (*pos)++;
2275 return NULL;
2276}
2277
2278static void pppol2tp_seq_stop(struct seq_file *p, void *v)
2279{
2280 /* nothing to do */
2281}
2282
2283static void pppol2tp_seq_tunnel_show(struct seq_file *m, void *v)
2284{
2285 struct pppol2tp_tunnel *tunnel = v;
2286
2287 seq_printf(m, "\nTUNNEL '%s', %c %d\n",
2288 tunnel->name,
2289 (tunnel == tunnel->sock->sk_user_data) ? 'Y':'N',
2290 atomic_read(&tunnel->ref_count) - 1);
2291 seq_printf(m, " %08x %llu/%llu/%llu %llu/%llu/%llu\n",
2292 tunnel->debug,
0efeaa33
AM		 2293 (unsigned long long)tunnel->stats.tx_packets,
2294 (unsigned long long)tunnel->stats.tx_bytes,
2295 (unsigned long long)tunnel->stats.tx_errors,
2296 (unsigned long long)tunnel->stats.rx_packets,
2297 (unsigned long long)tunnel->stats.rx_bytes,
2298 (unsigned long long)tunnel->stats.rx_errors);
3557baab
JC		 2299}
2300
2301static void pppol2tp_seq_session_show(struct seq_file *m, void *v)
2302{
2303 struct pppol2tp_session *session = v;
2304
2305 seq_printf(m, " SESSION '%s' %08X/%d %04X/%04X -> "
2306 "%04X/%04X %d %c\n",
2307 session->name,
2308 ntohl(session->tunnel_addr.addr.sin_addr.s_addr),
2309 ntohs(session->tunnel_addr.addr.sin_port),
2310 session->tunnel_addr.s_tunnel,
2311 session->tunnel_addr.s_session,
2312 session->tunnel_addr.d_tunnel,
2313 session->tunnel_addr.d_session,
2314 session->sock->sk_state,
2315 (session == session->sock->sk_user_data) ?
2316 'Y' : 'N');
2317 seq_printf(m, " %d/%d/%c/%c/%s %08x %u\n",
2318 session->mtu, session->mru,
2319 session->recv_seq ? 'R' : '-',
2320 session->send_seq ? 'S' : '-',
2321 session->lns_mode ? "LNS" : "LAC",
2322 session->debug,
2323 jiffies_to_msecs(session->reorder_timeout));
2324 seq_printf(m, " %hu/%hu %llu/%llu/%llu %llu/%llu/%llu\n",
2325 session->nr, session->ns,
0efeaa33
AM		 2326 (unsigned long long)session->stats.tx_packets,
2327 (unsigned long long)session->stats.tx_bytes,
2328 (unsigned long long)session->stats.tx_errors,
2329 (unsigned long long)session->stats.rx_packets,
2330 (unsigned long long)session->stats.rx_bytes,
2331 (unsigned long long)session->stats.rx_errors);
3557baab
JC		 2332}
2333
2334static int pppol2tp_seq_show(struct seq_file *m, void *v)
2335{
2336 struct pppol2tp_seq_data *pd = v;
2337
2338 /* display header on line 1 */
2339 if (v == SEQ_START_TOKEN) {
2340 seq_puts(m, "PPPoL2TP driver info, " PPPOL2TP_DRV_VERSION "\n");
2341 seq_puts(m, "TUNNEL name, user-data-ok session-count\n");
2342 seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
2343 seq_puts(m, " SESSION name, addr/port src-tid/sid "
2344 "dest-tid/sid state user-data-ok\n");
2345 seq_puts(m, " mtu/mru/rcvseq/sendseq/lns debug reorderto\n");
2346 seq_puts(m, " nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
2347 goto out;
2348 }
2349
2350 /* Show the tunnel or session context.
2351 */
2352 if (pd->session == NULL)
2353 pppol2tp_seq_tunnel_show(m, pd->tunnel);
2354 else
2355 pppol2tp_seq_session_show(m, pd->session);
2356
2357out:
2358 return 0;
2359}
2360
2361static struct seq_operations pppol2tp_seq_ops = {
2362 .start = pppol2tp_seq_start,
2363 .next = pppol2tp_seq_next,
2364 .stop = pppol2tp_seq_stop,
2365 .show = pppol2tp_seq_show,
2366};
2367
2368/* Called when our /proc file is opened. We allocate data for use when
2369 * iterating our tunnel / session contexts and store it in the private
2370 * data of the seq_file.
2371 */
2372static int pppol2tp_proc_open(struct inode *inode, struct file *file)
2373{
2374 struct seq_file *m;
2375 struct pppol2tp_seq_data *pd;
2376 int ret = 0;
2377
2378 ret = seq_open(file, &pppol2tp_seq_ops);
2379 if (ret < 0)
2380 goto out;
2381
2382 m = file->private_data;
2383
2384 /* Allocate and fill our proc_data for access later */
2385 ret = -ENOMEM;
2386 m->private = kzalloc(sizeof(struct pppol2tp_seq_data), GFP_KERNEL);
2387 if (m->private == NULL)
2388 goto out;
2389
2390 pd = m->private;
2391 ret = 0;
2392
2393out:
2394 return ret;
2395}
2396
2397/* Called when /proc file access completes.
2398 */
2399static int pppol2tp_proc_release(struct inode *inode, struct file *file)
2400{
2401 struct seq_file *m = (struct seq_file *)file->private_data;
2402
2403 kfree(m->private);
2404 m->private = NULL;
2405
2406 return seq_release(inode, file);
2407}
2408
2409static struct file_operations pppol2tp_proc_fops = {
2410 .owner = THIS_MODULE,
2411 .open = pppol2tp_proc_open,
2412 .read = seq_read,
2413 .llseek = seq_lseek,
2414 .release = pppol2tp_proc_release,
2415};
2416
2417static struct proc_dir_entry *pppol2tp_proc;
2418
2419#endif /* CONFIG_PROC_FS */
2420
2421/*****************************************************************************
2422 * Init and cleanup
2423 *****************************************************************************/
2424
2425static struct proto_ops pppol2tp_ops = {
2426 .family = AF_PPPOX,
2427 .owner = THIS_MODULE,
2428 .release = pppol2tp_release,
2429 .bind = sock_no_bind,
2430 .connect = pppol2tp_connect,
2431 .socketpair = sock_no_socketpair,
2432 .accept = sock_no_accept,
2433 .getname = pppol2tp_getname,
2434 .poll = datagram_poll,
2435 .listen = sock_no_listen,
2436 .shutdown = sock_no_shutdown,
2437 .setsockopt = pppol2tp_setsockopt,
2438 .getsockopt = pppol2tp_getsockopt,
2439 .sendmsg = pppol2tp_sendmsg,
2440 .recvmsg = pppol2tp_recvmsg,
2441 .mmap = sock_no_mmap,
2442 .ioctl = pppox_ioctl,
2443};
2444
2445static struct pppox_proto pppol2tp_proto = {
2446 .create = pppol2tp_create,
2447 .ioctl = pppol2tp_ioctl
2448};
2449
2450static int __init pppol2tp_init(void)
2451{
2452 int err;
2453
2454 err = proto_register(&pppol2tp_sk_proto, 0);
2455 if (err)
2456 goto out;
2457 err = register_pppox_proto(PX_PROTO_OL2TP, &pppol2tp_proto);
2458 if (err)
2459 goto out_unregister_pppol2tp_proto;
2460
2461#ifdef CONFIG_PROC_FS
457c4cbc 2462 pppol2tp_proc = create_proc_entry("pppol2tp", 0, init_net.proc_net);
3557baab
JC		 2463 if (!pppol2tp_proc) {
2464 err = -ENOMEM;
2465 goto out_unregister_pppox_proto;
2466 }
2467 pppol2tp_proc->proc_fops = &pppol2tp_proc_fops;
2468#endif /* CONFIG_PROC_FS */
2469 printk(KERN_INFO "PPPoL2TP kernel driver, %s\n",
2470 PPPOL2TP_DRV_VERSION);
2471
2472out:
2473 return err;
731a0609 2474#ifdef CONFIG_PROC_FS
3557baab
JC		 2475out_unregister_pppox_proto:
2476 unregister_pppox_proto(PX_PROTO_OL2TP);
731a0609 2477#endif
3557baab
JC		 2478out_unregister_pppol2tp_proto:
2479 proto_unregister(&pppol2tp_sk_proto);
2480 goto out;
2481}
2482
2483static void __exit pppol2tp_exit(void)
2484{
2485 unregister_pppox_proto(PX_PROTO_OL2TP);
2486
2487#ifdef CONFIG_PROC_FS
457c4cbc 2488 remove_proc_entry("pppol2tp", init_net.proc_net);
3557baab
JC		 2489#endif
2490 proto_unregister(&pppol2tp_sk_proto);
2491}
2492
2493module_init(pppol2tp_init);
2494module_exit(pppol2tp_exit);
2495
2450022a 2496MODULE_AUTHOR("Martijn van Oosterhout <kleptog@svana.org>, "
3557baab
JC		 2497 "James Chapman <jchapman@katalix.com>");
2498MODULE_DESCRIPTION("PPP over L2TP over UDP");
2499MODULE_LICENSE("GPL");
2500MODULE_VERSION(PPPOL2TP_DRV_VERSION);
kernel source for telekom puls (alcatel/mediatek)