4 * Copyright (c) 2008,2009,2010 Katalix Systems Ltd
6 * This file contains some code of the original L2TPv2 pppol2tp
7 * driver, which has the following copyright:
9 * Authors: Martijn van Oosterhout <kleptog@svana.org>
10 * James Chapman (jchapman@katalix.com)
12 * Michal Ostrowski <mostrows@speakeasy.net>
13 * Arnaldo Carvalho de Melo <acme@xconectiva.com.br>
14 * David S. Miller (davem@redhat.com)
16 * This program is free software; you can redistribute it and/or modify
17 * it under the terms of the GNU General Public License version 2 as
18 * published by the Free Software Foundation.
21 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
23 #include <linux/module.h>
24 #include <linux/string.h>
25 #include <linux/list.h>
26 #include <linux/rculist.h>
27 #include <linux/uaccess.h>
29 #include <linux/kernel.h>
30 #include <linux/spinlock.h>
31 #include <linux/kthread.h>
32 #include <linux/sched.h>
33 #include <linux/slab.h>
34 #include <linux/errno.h>
35 #include <linux/jiffies.h>
37 #include <linux/netdevice.h>
38 #include <linux/net.h>
39 #include <linux/inetdevice.h>
40 #include <linux/skbuff.h>
41 #include <linux/init.h>
44 #include <linux/udp.h>
45 #include <linux/l2tp.h>
46 #include <linux/hash.h>
47 #include <linux/sort.h>
48 #include <linux/file.h>
49 #include <linux/nsproxy.h>
50 #include <net/net_namespace.h>
51 #include <net/netns/generic.h>
55 #include <net/udp_tunnel.h>
56 #include <net/inet_common.h>
58 #include <net/protocol.h>
59 #include <net/inet6_connection_sock.h>
60 #include <net/inet_ecn.h>
61 #include <net/ip6_route.h>
62 #include <net/ip6_checksum.h>
64 #include <asm/byteorder.h>
65 #include <linux/atomic.h>
67 #include "l2tp_core.h"
69 #define L2TP_DRV_VERSION "V2.0"
71 /* L2TP header constants */
72 #define L2TP_HDRFLAG_T 0x8000
73 #define L2TP_HDRFLAG_L 0x4000
74 #define L2TP_HDRFLAG_S 0x0800
75 #define L2TP_HDRFLAG_O 0x0200
76 #define L2TP_HDRFLAG_P 0x0100
78 #define L2TP_HDR_VER_MASK 0x000F
79 #define L2TP_HDR_VER_2 0x0002
80 #define L2TP_HDR_VER_3 0x0003
82 /* L2TPv3 default L2-specific sublayer */
83 #define L2TP_SLFLAG_S 0x40000000
84 #define L2TP_SL_SEQ_MASK 0x00ffffff
86 #define L2TP_HDR_SIZE_SEQ 10
87 #define L2TP_HDR_SIZE_NOSEQ 6
89 /* Default trace flags */
90 #define L2TP_DEFAULT_DEBUG_FLAGS 0
92 /* Private data stored for received packets in the skb.
98 unsigned long expires
;
101 #define L2TP_SKB_CB(skb) ((struct l2tp_skb_cb *) &skb->cb[sizeof(struct inet_skb_parm)])
103 static struct workqueue_struct
*l2tp_wq
;
105 /* per-net private data for this module */
106 static unsigned int l2tp_net_id
;
108 struct list_head l2tp_tunnel_list
;
109 spinlock_t l2tp_tunnel_list_lock
;
110 struct hlist_head l2tp_session_hlist
[L2TP_HASH_SIZE_2
];
111 spinlock_t l2tp_session_hlist_lock
;
114 #if IS_ENABLED(CONFIG_IPV6)
115 static bool l2tp_sk_is_v6(struct sock
*sk
)
117 return sk
->sk_family
== PF_INET6
&&
118 !ipv6_addr_v4mapped(&sk
->sk_v6_daddr
);
122 static inline struct l2tp_tunnel
*l2tp_tunnel(struct sock
*sk
)
124 return sk
->sk_user_data
;
127 static inline struct l2tp_net
*l2tp_pernet(const struct net
*net
)
131 return net_generic(net
, l2tp_net_id
);
134 /* Session hash global list for L2TPv3.
135 * The session_id SHOULD be random according to RFC3931, but several
136 * L2TP implementations use incrementing session_ids. So we do a real
137 * hash on the session_id, rather than a simple bitmask.
139 static inline struct hlist_head
*
140 l2tp_session_id_hash_2(struct l2tp_net
*pn
, u32 session_id
)
142 return &pn
->l2tp_session_hlist
[hash_32(session_id
, L2TP_HASH_BITS_2
)];
146 /* Session hash list.
147 * The session_id SHOULD be random according to RFC2661, but several
148 * L2TP implementations (Cisco and Microsoft) use incrementing
149 * session_ids. So we do a real hash on the session_id, rather than a
152 static inline struct hlist_head
*
153 l2tp_session_id_hash(struct l2tp_tunnel
*tunnel
, u32 session_id
)
155 return &tunnel
->session_hlist
[hash_32(session_id
, L2TP_HASH_BITS
)];
158 void l2tp_tunnel_free(struct l2tp_tunnel
*tunnel
)
160 sock_put(tunnel
->sock
);
161 /* the tunnel is freed in the socket destructor */
163 EXPORT_SYMBOL(l2tp_tunnel_free
);
165 /* Lookup a tunnel. A new reference is held on the returned tunnel. */
166 struct l2tp_tunnel
*l2tp_tunnel_get(const struct net
*net
, u32 tunnel_id
)
168 const struct l2tp_net
*pn
= l2tp_pernet(net
);
169 struct l2tp_tunnel
*tunnel
;
172 list_for_each_entry_rcu(tunnel
, &pn
->l2tp_tunnel_list
, list
) {
173 if (tunnel
->tunnel_id
== tunnel_id
) {
174 l2tp_tunnel_inc_refcount(tunnel
);
175 rcu_read_unlock_bh();
180 rcu_read_unlock_bh();
184 EXPORT_SYMBOL_GPL(l2tp_tunnel_get
);
186 struct l2tp_tunnel
*l2tp_tunnel_get_nth(const struct net
*net
, int nth
)
188 const struct l2tp_net
*pn
= l2tp_pernet(net
);
189 struct l2tp_tunnel
*tunnel
;
193 list_for_each_entry_rcu(tunnel
, &pn
->l2tp_tunnel_list
, list
) {
195 l2tp_tunnel_inc_refcount(tunnel
);
196 rcu_read_unlock_bh();
200 rcu_read_unlock_bh();
204 EXPORT_SYMBOL_GPL(l2tp_tunnel_get_nth
);
206 /* Lookup a session. A new reference is held on the returned session. */
207 struct l2tp_session
*l2tp_session_get(const struct net
*net
,
208 struct l2tp_tunnel
*tunnel
,
211 struct hlist_head
*session_list
;
212 struct l2tp_session
*session
;
215 struct l2tp_net
*pn
= l2tp_pernet(net
);
217 session_list
= l2tp_session_id_hash_2(pn
, session_id
);
220 hlist_for_each_entry_rcu(session
, session_list
, global_hlist
) {
221 if (session
->session_id
== session_id
) {
222 l2tp_session_inc_refcount(session
);
223 rcu_read_unlock_bh();
228 rcu_read_unlock_bh();
233 session_list
= l2tp_session_id_hash(tunnel
, session_id
);
234 read_lock_bh(&tunnel
->hlist_lock
);
235 hlist_for_each_entry(session
, session_list
, hlist
) {
236 if (session
->session_id
== session_id
) {
237 l2tp_session_inc_refcount(session
);
238 read_unlock_bh(&tunnel
->hlist_lock
);
243 read_unlock_bh(&tunnel
->hlist_lock
);
247 EXPORT_SYMBOL_GPL(l2tp_session_get
);
249 struct l2tp_session
*l2tp_session_get_nth(struct l2tp_tunnel
*tunnel
, int nth
)
252 struct l2tp_session
*session
;
255 read_lock_bh(&tunnel
->hlist_lock
);
256 for (hash
= 0; hash
< L2TP_HASH_SIZE
; hash
++) {
257 hlist_for_each_entry(session
, &tunnel
->session_hlist
[hash
], hlist
) {
259 l2tp_session_inc_refcount(session
);
260 read_unlock_bh(&tunnel
->hlist_lock
);
266 read_unlock_bh(&tunnel
->hlist_lock
);
270 EXPORT_SYMBOL_GPL(l2tp_session_get_nth
);
272 /* Lookup a session by interface name.
273 * This is very inefficient but is only used by management interfaces.
275 struct l2tp_session
*l2tp_session_get_by_ifname(const struct net
*net
,
278 struct l2tp_net
*pn
= l2tp_pernet(net
);
280 struct l2tp_session
*session
;
283 for (hash
= 0; hash
< L2TP_HASH_SIZE_2
; hash
++) {
284 hlist_for_each_entry_rcu(session
, &pn
->l2tp_session_hlist
[hash
], global_hlist
) {
285 if (!strcmp(session
->ifname
, ifname
)) {
286 l2tp_session_inc_refcount(session
);
287 rcu_read_unlock_bh();
294 rcu_read_unlock_bh();
298 EXPORT_SYMBOL_GPL(l2tp_session_get_by_ifname
);
300 int l2tp_session_register(struct l2tp_session
*session
,
301 struct l2tp_tunnel
*tunnel
)
303 struct l2tp_session
*session_walk
;
304 struct hlist_head
*g_head
;
305 struct hlist_head
*head
;
309 head
= l2tp_session_id_hash(tunnel
, session
->session_id
);
311 write_lock_bh(&tunnel
->hlist_lock
);
312 if (!tunnel
->acpt_newsess
) {
317 hlist_for_each_entry(session_walk
, head
, hlist
)
318 if (session_walk
->session_id
== session
->session_id
) {
323 if (tunnel
->version
== L2TP_HDR_VER_3
) {
324 pn
= l2tp_pernet(tunnel
->l2tp_net
);
325 g_head
= l2tp_session_id_hash_2(l2tp_pernet(tunnel
->l2tp_net
),
326 session
->session_id
);
328 spin_lock_bh(&pn
->l2tp_session_hlist_lock
);
330 hlist_for_each_entry(session_walk
, g_head
, global_hlist
)
331 if (session_walk
->session_id
== session
->session_id
) {
333 goto err_tlock_pnlock
;
336 l2tp_tunnel_inc_refcount(tunnel
);
337 hlist_add_head_rcu(&session
->global_hlist
, g_head
);
339 spin_unlock_bh(&pn
->l2tp_session_hlist_lock
);
341 l2tp_tunnel_inc_refcount(tunnel
);
344 hlist_add_head(&session
->hlist
, head
);
345 write_unlock_bh(&tunnel
->hlist_lock
);
350 spin_unlock_bh(&pn
->l2tp_session_hlist_lock
);
352 write_unlock_bh(&tunnel
->hlist_lock
);
356 EXPORT_SYMBOL_GPL(l2tp_session_register
);
358 /*****************************************************************************
359 * Receive data handling
360 *****************************************************************************/
362 /* Queue a skb in order. We come here only if the skb has an L2TP sequence
365 static void l2tp_recv_queue_skb(struct l2tp_session
*session
, struct sk_buff
*skb
)
367 struct sk_buff
*skbp
;
369 u32 ns
= L2TP_SKB_CB(skb
)->ns
;
371 spin_lock_bh(&session
->reorder_q
.lock
);
372 skb_queue_walk_safe(&session
->reorder_q
, skbp
, tmp
) {
373 if (L2TP_SKB_CB(skbp
)->ns
> ns
) {
374 __skb_queue_before(&session
->reorder_q
, skbp
, skb
);
375 l2tp_dbg(session
, L2TP_MSG_SEQ
,
376 "%s: pkt %hu, inserted before %hu, reorder_q len=%d\n",
377 session
->name
, ns
, L2TP_SKB_CB(skbp
)->ns
,
378 skb_queue_len(&session
->reorder_q
));
379 atomic_long_inc(&session
->stats
.rx_oos_packets
);
384 __skb_queue_tail(&session
->reorder_q
, skb
);
387 spin_unlock_bh(&session
->reorder_q
.lock
);
390 /* Dequeue a single skb.
392 static void l2tp_recv_dequeue_skb(struct l2tp_session
*session
, struct sk_buff
*skb
)
394 struct l2tp_tunnel
*tunnel
= session
->tunnel
;
395 int length
= L2TP_SKB_CB(skb
)->length
;
397 /* We're about to requeue the skb, so return resources
398 * to its current owner (a socket receive buffer).
402 atomic_long_inc(&tunnel
->stats
.rx_packets
);
403 atomic_long_add(length
, &tunnel
->stats
.rx_bytes
);
404 atomic_long_inc(&session
->stats
.rx_packets
);
405 atomic_long_add(length
, &session
->stats
.rx_bytes
);
407 if (L2TP_SKB_CB(skb
)->has_seq
) {
410 session
->nr
&= session
->nr_max
;
412 l2tp_dbg(session
, L2TP_MSG_SEQ
, "%s: updated nr to %hu\n",
413 session
->name
, session
->nr
);
416 /* call private receive handler */
417 if (session
->recv_skb
!= NULL
)
418 (*session
->recv_skb
)(session
, skb
, L2TP_SKB_CB(skb
)->length
);
423 /* Dequeue skbs from the session's reorder_q, subject to packet order.
424 * Skbs that have been in the queue for too long are simply discarded.
426 static void l2tp_recv_dequeue(struct l2tp_session
*session
)
431 /* If the pkt at the head of the queue has the nr that we
432 * expect to send up next, dequeue it and any other
433 * in-sequence packets behind it.
436 spin_lock_bh(&session
->reorder_q
.lock
);
437 skb_queue_walk_safe(&session
->reorder_q
, skb
, tmp
) {
438 if (time_after(jiffies
, L2TP_SKB_CB(skb
)->expires
)) {
439 atomic_long_inc(&session
->stats
.rx_seq_discards
);
440 atomic_long_inc(&session
->stats
.rx_errors
);
441 l2tp_dbg(session
, L2TP_MSG_SEQ
,
442 "%s: oos pkt %u len %d discarded (too old), waiting for %u, reorder_q_len=%d\n",
443 session
->name
, L2TP_SKB_CB(skb
)->ns
,
444 L2TP_SKB_CB(skb
)->length
, session
->nr
,
445 skb_queue_len(&session
->reorder_q
));
446 session
->reorder_skip
= 1;
447 __skb_unlink(skb
, &session
->reorder_q
);
452 if (L2TP_SKB_CB(skb
)->has_seq
) {
453 if (session
->reorder_skip
) {
454 l2tp_dbg(session
, L2TP_MSG_SEQ
,
455 "%s: advancing nr to next pkt: %u -> %u",
456 session
->name
, session
->nr
,
457 L2TP_SKB_CB(skb
)->ns
);
458 session
->reorder_skip
= 0;
459 session
->nr
= L2TP_SKB_CB(skb
)->ns
;
461 if (L2TP_SKB_CB(skb
)->ns
!= session
->nr
) {
462 l2tp_dbg(session
, L2TP_MSG_SEQ
,
463 "%s: holding oos pkt %u len %d, waiting for %u, reorder_q_len=%d\n",
464 session
->name
, L2TP_SKB_CB(skb
)->ns
,
465 L2TP_SKB_CB(skb
)->length
, session
->nr
,
466 skb_queue_len(&session
->reorder_q
));
470 __skb_unlink(skb
, &session
->reorder_q
);
472 /* Process the skb. We release the queue lock while we
473 * do so to let other contexts process the queue.
475 spin_unlock_bh(&session
->reorder_q
.lock
);
476 l2tp_recv_dequeue_skb(session
, skb
);
481 spin_unlock_bh(&session
->reorder_q
.lock
);
484 static int l2tp_seq_check_rx_window(struct l2tp_session
*session
, u32 nr
)
488 if (nr
>= session
->nr
)
489 nws
= nr
- session
->nr
;
491 nws
= (session
->nr_max
+ 1) - (session
->nr
- nr
);
493 return nws
< session
->nr_window_size
;
496 /* If packet has sequence numbers, queue it if acceptable. Returns 0 if
497 * acceptable, else non-zero.
499 static int l2tp_recv_data_seq(struct l2tp_session
*session
, struct sk_buff
*skb
)
501 if (!l2tp_seq_check_rx_window(session
, L2TP_SKB_CB(skb
)->ns
)) {
502 /* Packet sequence number is outside allowed window.
505 l2tp_dbg(session
, L2TP_MSG_SEQ
,
506 "%s: pkt %u len %d discarded, outside window, nr=%u\n",
507 session
->name
, L2TP_SKB_CB(skb
)->ns
,
508 L2TP_SKB_CB(skb
)->length
, session
->nr
);
512 if (session
->reorder_timeout
!= 0) {
513 /* Packet reordering enabled. Add skb to session's
514 * reorder queue, in order of ns.
516 l2tp_recv_queue_skb(session
, skb
);
520 /* Packet reordering disabled. Discard out-of-sequence packets, while
521 * tracking the number if in-sequence packets after the first OOS packet
522 * is seen. After nr_oos_count_max in-sequence packets, reset the
523 * sequence number to re-enable packet reception.
525 if (L2TP_SKB_CB(skb
)->ns
== session
->nr
) {
526 skb_queue_tail(&session
->reorder_q
, skb
);
528 u32 nr_oos
= L2TP_SKB_CB(skb
)->ns
;
529 u32 nr_next
= (session
->nr_oos
+ 1) & session
->nr_max
;
531 if (nr_oos
== nr_next
)
532 session
->nr_oos_count
++;
534 session
->nr_oos_count
= 0;
536 session
->nr_oos
= nr_oos
;
537 if (session
->nr_oos_count
> session
->nr_oos_count_max
) {
538 session
->reorder_skip
= 1;
539 l2tp_dbg(session
, L2TP_MSG_SEQ
,
540 "%s: %d oos packets received. Resetting sequence numbers\n",
541 session
->name
, session
->nr_oos_count
);
543 if (!session
->reorder_skip
) {
544 atomic_long_inc(&session
->stats
.rx_seq_discards
);
545 l2tp_dbg(session
, L2TP_MSG_SEQ
,
546 "%s: oos pkt %u len %d discarded, waiting for %u, reorder_q_len=%d\n",
547 session
->name
, L2TP_SKB_CB(skb
)->ns
,
548 L2TP_SKB_CB(skb
)->length
, session
->nr
,
549 skb_queue_len(&session
->reorder_q
));
552 skb_queue_tail(&session
->reorder_q
, skb
);
562 /* Do receive processing of L2TP data frames. We handle both L2TPv2
563 * and L2TPv3 data frames here.
565 * L2TPv2 Data Message Header
568 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
569 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
570 * |T|L|x|x|S|x|O|P|x|x|x|x| Ver | Length (opt) |
571 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
572 * | Tunnel ID | Session ID |
573 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
574 * | Ns (opt) | Nr (opt) |
575 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
576 * | Offset Size (opt) | Offset pad... (opt)
577 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
579 * Data frames are marked by T=0. All other fields are the same as
580 * those in L2TP control frames.
582 * L2TPv3 Data Message Header
584 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
585 * | L2TP Session Header |
586 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
587 * | L2-Specific Sublayer |
588 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
589 * | Tunnel Payload ...
590 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
592 * L2TPv3 Session Header Over IP
595 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
596 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
598 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
599 * | Cookie (optional, maximum 64 bits)...
600 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
602 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
604 * L2TPv3 L2-Specific Sublayer Format
607 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
608 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
609 * |x|S|x|x|x|x|x|x| Sequence Number |
610 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
612 * Cookie value, sublayer format and offset (pad) are negotiated with
613 * the peer when the session is set up. Unlike L2TPv2, we do not need
614 * to parse the packet header to determine if optional fields are
617 * Caller must already have parsed the frame and determined that it is
618 * a data (not control) frame before coming here. Fields up to the
619 * session-id have already been parsed and ptr points to the data
620 * after the session-id.
622 void l2tp_recv_common(struct l2tp_session
*session
, struct sk_buff
*skb
,
623 unsigned char *ptr
, unsigned char *optr
, u16 hdrflags
,
624 int length
, int (*payload_hook
)(struct sk_buff
*skb
))
626 struct l2tp_tunnel
*tunnel
= session
->tunnel
;
630 /* Parse and check optional cookie */
631 if (session
->peer_cookie_len
> 0) {
632 if (memcmp(ptr
, &session
->peer_cookie
[0], session
->peer_cookie_len
)) {
633 l2tp_info(tunnel
, L2TP_MSG_DATA
,
634 "%s: cookie mismatch (%u/%u). Discarding.\n",
635 tunnel
->name
, tunnel
->tunnel_id
,
636 session
->session_id
);
637 atomic_long_inc(&session
->stats
.rx_cookie_discards
);
640 ptr
+= session
->peer_cookie_len
;
643 /* Handle the optional sequence numbers. Sequence numbers are
644 * in different places for L2TPv2 and L2TPv3.
646 * If we are the LAC, enable/disable sequence numbers under
647 * the control of the LNS. If no sequence numbers present but
648 * we were expecting them, discard frame.
651 L2TP_SKB_CB(skb
)->has_seq
= 0;
652 if (tunnel
->version
== L2TP_HDR_VER_2
) {
653 if (hdrflags
& L2TP_HDRFLAG_S
) {
654 ns
= ntohs(*(__be16
*) ptr
);
656 nr
= ntohs(*(__be16
*) ptr
);
659 /* Store L2TP info in the skb */
660 L2TP_SKB_CB(skb
)->ns
= ns
;
661 L2TP_SKB_CB(skb
)->has_seq
= 1;
663 l2tp_dbg(session
, L2TP_MSG_SEQ
,
664 "%s: recv data ns=%u, nr=%u, session nr=%u\n",
665 session
->name
, ns
, nr
, session
->nr
);
667 } else if (session
->l2specific_type
== L2TP_L2SPECTYPE_DEFAULT
) {
668 u32 l2h
= ntohl(*(__be32
*) ptr
);
670 if (l2h
& 0x40000000) {
671 ns
= l2h
& 0x00ffffff;
673 /* Store L2TP info in the skb */
674 L2TP_SKB_CB(skb
)->ns
= ns
;
675 L2TP_SKB_CB(skb
)->has_seq
= 1;
677 l2tp_dbg(session
, L2TP_MSG_SEQ
,
678 "%s: recv data ns=%u, session nr=%u\n",
679 session
->name
, ns
, session
->nr
);
683 /* Advance past L2-specific header, if present */
684 ptr
+= session
->l2specific_len
;
686 if (L2TP_SKB_CB(skb
)->has_seq
) {
687 /* Received a packet with sequence numbers. If we're the LNS,
688 * check if we sre sending sequence numbers and if not,
691 if ((!session
->lns_mode
) && (!session
->send_seq
)) {
692 l2tp_info(session
, L2TP_MSG_SEQ
,
693 "%s: requested to enable seq numbers by LNS\n",
695 session
->send_seq
= 1;
696 l2tp_session_set_header_len(session
, tunnel
->version
);
699 /* No sequence numbers.
700 * If user has configured mandatory sequence numbers, discard.
702 if (session
->recv_seq
) {
703 l2tp_warn(session
, L2TP_MSG_SEQ
,
704 "%s: recv data has no seq numbers when required. Discarding.\n",
706 atomic_long_inc(&session
->stats
.rx_seq_discards
);
710 /* If we're the LAC and we're sending sequence numbers, the
711 * LNS has requested that we no longer send sequence numbers.
712 * If we're the LNS and we're sending sequence numbers, the
713 * LAC is broken. Discard the frame.
715 if ((!session
->lns_mode
) && (session
->send_seq
)) {
716 l2tp_info(session
, L2TP_MSG_SEQ
,
717 "%s: requested to disable seq numbers by LNS\n",
719 session
->send_seq
= 0;
720 l2tp_session_set_header_len(session
, tunnel
->version
);
721 } else if (session
->send_seq
) {
722 l2tp_warn(session
, L2TP_MSG_SEQ
,
723 "%s: recv data has no seq numbers when required. Discarding.\n",
725 atomic_long_inc(&session
->stats
.rx_seq_discards
);
730 /* Session data offset is handled differently for L2TPv2 and
731 * L2TPv3. For L2TPv2, there is an optional 16-bit value in
732 * the header. For L2TPv3, the offset is negotiated using AVPs
733 * in the session setup control protocol.
735 if (tunnel
->version
== L2TP_HDR_VER_2
) {
736 /* If offset bit set, skip it. */
737 if (hdrflags
& L2TP_HDRFLAG_O
) {
738 offset
= ntohs(*(__be16
*)ptr
);
742 ptr
+= session
->offset
;
745 if (!pskb_may_pull(skb
, offset
))
748 __skb_pull(skb
, offset
);
750 /* If caller wants to process the payload before we queue the
754 if ((*payload_hook
)(skb
))
757 /* Prepare skb for adding to the session's reorder_q. Hold
758 * packets for max reorder_timeout or 1 second if not
761 L2TP_SKB_CB(skb
)->length
= length
;
762 L2TP_SKB_CB(skb
)->expires
= jiffies
+
763 (session
->reorder_timeout
? session
->reorder_timeout
: HZ
);
765 /* Add packet to the session's receive queue. Reordering is done here, if
766 * enabled. Saved L2TP protocol info is stored in skb->sb[].
768 if (L2TP_SKB_CB(skb
)->has_seq
) {
769 if (l2tp_recv_data_seq(session
, skb
))
772 /* No sequence numbers. Add the skb to the tail of the
773 * reorder queue. This ensures that it will be
774 * delivered after all previous sequenced skbs.
776 skb_queue_tail(&session
->reorder_q
, skb
);
779 /* Try to dequeue as many skbs from reorder_q as we can. */
780 l2tp_recv_dequeue(session
);
785 atomic_long_inc(&session
->stats
.rx_errors
);
788 EXPORT_SYMBOL(l2tp_recv_common
);
790 /* Drop skbs from the session's reorder_q
792 int l2tp_session_queue_purge(struct l2tp_session
*session
)
794 struct sk_buff
*skb
= NULL
;
796 BUG_ON(session
->magic
!= L2TP_SESSION_MAGIC
);
797 while ((skb
= skb_dequeue(&session
->reorder_q
))) {
798 atomic_long_inc(&session
->stats
.rx_errors
);
803 EXPORT_SYMBOL_GPL(l2tp_session_queue_purge
);
805 /* Internal UDP receive frame. Do the real work of receiving an L2TP data frame
806 * here. The skb is not on a list when we get here.
807 * Returns 0 if the packet was a data packet and was successfully passed on.
808 * Returns 1 if the packet was not a good data packet and could not be
809 * forwarded. All such packets are passed up to userspace to deal with.
811 static int l2tp_udp_recv_core(struct l2tp_tunnel
*tunnel
, struct sk_buff
*skb
,
812 int (*payload_hook
)(struct sk_buff
*skb
))
814 struct l2tp_session
*session
= NULL
;
815 unsigned char *ptr
, *optr
;
817 u32 tunnel_id
, session_id
;
821 /* UDP has verifed checksum */
823 /* UDP always verifies the packet length. */
824 __skb_pull(skb
, sizeof(struct udphdr
));
827 if (!pskb_may_pull(skb
, L2TP_HDR_SIZE_SEQ
)) {
828 l2tp_info(tunnel
, L2TP_MSG_DATA
,
829 "%s: recv short packet (len=%d)\n",
830 tunnel
->name
, skb
->len
);
834 /* Trace packet contents, if enabled */
835 if (tunnel
->debug
& L2TP_MSG_DATA
) {
836 length
= min(32u, skb
->len
);
837 if (!pskb_may_pull(skb
, length
))
840 pr_debug("%s: recv\n", tunnel
->name
);
841 print_hex_dump_bytes("", DUMP_PREFIX_OFFSET
, skb
->data
, length
);
844 /* Point to L2TP header */
845 optr
= ptr
= skb
->data
;
847 /* Get L2TP header flags */
848 hdrflags
= ntohs(*(__be16
*) ptr
);
850 /* Check protocol version */
851 version
= hdrflags
& L2TP_HDR_VER_MASK
;
852 if (version
!= tunnel
->version
) {
853 l2tp_info(tunnel
, L2TP_MSG_DATA
,
854 "%s: recv protocol version mismatch: got %d expected %d\n",
855 tunnel
->name
, version
, tunnel
->version
);
859 /* Get length of L2TP packet */
862 /* If type is control packet, it is handled by userspace. */
863 if (hdrflags
& L2TP_HDRFLAG_T
) {
864 l2tp_dbg(tunnel
, L2TP_MSG_DATA
,
865 "%s: recv control packet, len=%d\n",
866 tunnel
->name
, length
);
873 if (tunnel
->version
== L2TP_HDR_VER_2
) {
874 /* If length is present, skip it */
875 if (hdrflags
& L2TP_HDRFLAG_L
)
878 /* Extract tunnel and session ID */
879 tunnel_id
= ntohs(*(__be16
*) ptr
);
881 session_id
= ntohs(*(__be16
*) ptr
);
884 ptr
+= 2; /* skip reserved bits */
885 tunnel_id
= tunnel
->tunnel_id
;
886 session_id
= ntohl(*(__be32
*) ptr
);
890 /* Find the session context */
891 session
= l2tp_session_get(tunnel
->l2tp_net
, tunnel
, session_id
);
892 if (!session
|| !session
->recv_skb
) {
894 l2tp_session_dec_refcount(session
);
896 /* Not found? Pass to userspace to deal with */
897 l2tp_info(tunnel
, L2TP_MSG_DATA
,
898 "%s: no session found (%u/%u). Passing up.\n",
899 tunnel
->name
, tunnel_id
, session_id
);
903 l2tp_recv_common(session
, skb
, ptr
, optr
, hdrflags
, length
, payload_hook
);
904 l2tp_session_dec_refcount(session
);
909 /* Put UDP header back */
910 __skb_push(skb
, sizeof(struct udphdr
));
915 /* UDP encapsulation receive handler. See net/ipv4/udp.c.
919 * >0: skb should be passed up to userspace as UDP.
921 int l2tp_udp_encap_recv(struct sock
*sk
, struct sk_buff
*skb
)
923 struct l2tp_tunnel
*tunnel
;
925 tunnel
= l2tp_tunnel(sk
);
929 l2tp_dbg(tunnel
, L2TP_MSG_DATA
, "%s: received %d bytes\n",
930 tunnel
->name
, skb
->len
);
932 if (l2tp_udp_recv_core(tunnel
, skb
, tunnel
->recv_payload_hook
))
940 EXPORT_SYMBOL_GPL(l2tp_udp_encap_recv
);
942 /************************************************************************
944 ***********************************************************************/
946 /* Build an L2TP header for the session into the buffer provided.
948 static int l2tp_build_l2tpv2_header(struct l2tp_session
*session
, void *buf
)
950 struct l2tp_tunnel
*tunnel
= session
->tunnel
;
953 u16 flags
= L2TP_HDR_VER_2
;
954 u32 tunnel_id
= tunnel
->peer_tunnel_id
;
955 u32 session_id
= session
->peer_session_id
;
957 if (session
->send_seq
)
958 flags
|= L2TP_HDRFLAG_S
;
960 /* Setup L2TP header. */
961 *bufp
++ = htons(flags
);
962 *bufp
++ = htons(tunnel_id
);
963 *bufp
++ = htons(session_id
);
964 if (session
->send_seq
) {
965 *bufp
++ = htons(session
->ns
);
968 session
->ns
&= 0xffff;
969 l2tp_dbg(session
, L2TP_MSG_SEQ
, "%s: updated ns to %u\n",
970 session
->name
, session
->ns
);
976 static int l2tp_build_l2tpv3_header(struct l2tp_session
*session
, void *buf
)
978 struct l2tp_tunnel
*tunnel
= session
->tunnel
;
982 /* Setup L2TP header. The header differs slightly for UDP and
983 * IP encapsulations. For UDP, there is 4 bytes of flags.
985 if (tunnel
->encap
== L2TP_ENCAPTYPE_UDP
) {
986 u16 flags
= L2TP_HDR_VER_3
;
987 *((__be16
*) bufp
) = htons(flags
);
989 *((__be16
*) bufp
) = 0;
993 *((__be32
*) bufp
) = htonl(session
->peer_session_id
);
995 if (session
->cookie_len
) {
996 memcpy(bufp
, &session
->cookie
[0], session
->cookie_len
);
997 bufp
+= session
->cookie_len
;
999 if (session
->l2specific_len
) {
1000 if (session
->l2specific_type
== L2TP_L2SPECTYPE_DEFAULT
) {
1002 if (session
->send_seq
) {
1003 l2h
= 0x40000000 | session
->ns
;
1005 session
->ns
&= 0xffffff;
1006 l2tp_dbg(session
, L2TP_MSG_SEQ
,
1007 "%s: updated ns to %u\n",
1008 session
->name
, session
->ns
);
1011 *((__be32
*) bufp
) = htonl(l2h
);
1013 bufp
+= session
->l2specific_len
;
1015 if (session
->offset
)
1016 bufp
+= session
->offset
;
1021 static int l2tp_xmit_core(struct l2tp_session
*session
, struct sk_buff
*skb
,
1022 struct flowi
*fl
, size_t data_len
)
1024 struct l2tp_tunnel
*tunnel
= session
->tunnel
;
1025 unsigned int len
= skb
->len
;
1029 if (session
->send_seq
)
1030 l2tp_dbg(session
, L2TP_MSG_DATA
, "%s: send %zd bytes, ns=%u\n",
1031 session
->name
, data_len
, session
->ns
- 1);
1033 l2tp_dbg(session
, L2TP_MSG_DATA
, "%s: send %zd bytes\n",
1034 session
->name
, data_len
);
1036 if (session
->debug
& L2TP_MSG_DATA
) {
1037 int uhlen
= (tunnel
->encap
== L2TP_ENCAPTYPE_UDP
) ? sizeof(struct udphdr
) : 0;
1038 unsigned char *datap
= skb
->data
+ uhlen
;
1040 pr_debug("%s: xmit\n", session
->name
);
1041 print_hex_dump_bytes("", DUMP_PREFIX_OFFSET
,
1042 datap
, min_t(size_t, 32, len
- uhlen
));
1045 /* Queue the packet to IP for output */
1047 #if IS_ENABLED(CONFIG_IPV6)
1048 if (l2tp_sk_is_v6(tunnel
->sock
))
1049 error
= inet6_csk_xmit(tunnel
->sock
, skb
, NULL
);
1052 error
= ip_queue_xmit(tunnel
->sock
, skb
, fl
);
1056 atomic_long_inc(&tunnel
->stats
.tx_packets
);
1057 atomic_long_add(len
, &tunnel
->stats
.tx_bytes
);
1058 atomic_long_inc(&session
->stats
.tx_packets
);
1059 atomic_long_add(len
, &session
->stats
.tx_bytes
);
1061 atomic_long_inc(&tunnel
->stats
.tx_errors
);
1062 atomic_long_inc(&session
->stats
.tx_errors
);
1068 /* If caller requires the skb to have a ppp header, the header must be
1069 * inserted in the skb data before calling this function.
1071 int l2tp_xmit_skb(struct l2tp_session
*session
, struct sk_buff
*skb
, int hdr_len
)
1073 int data_len
= skb
->len
;
1074 struct l2tp_tunnel
*tunnel
= session
->tunnel
;
1075 struct sock
*sk
= tunnel
->sock
;
1078 struct inet_sock
*inet
;
1080 int uhlen
= (tunnel
->encap
== L2TP_ENCAPTYPE_UDP
) ? sizeof(struct udphdr
) : 0;
1082 int ret
= NET_XMIT_SUCCESS
;
1084 /* Check that there's enough headroom in the skb to insert IP,
1085 * UDP and L2TP headers. If not enough, expand it to
1086 * make room. Adjust truesize.
1088 headroom
= NET_SKB_PAD
+ sizeof(struct iphdr
) +
1090 if (skb_cow_head(skb
, headroom
)) {
1092 return NET_XMIT_DROP
;
1095 /* Setup L2TP header */
1096 session
->build_header(session
, __skb_push(skb
, hdr_len
));
1098 /* Reset skb netfilter state */
1099 memset(&(IPCB(skb
)->opt
), 0, sizeof(IPCB(skb
)->opt
));
1100 IPCB(skb
)->flags
&= ~(IPSKB_XFRM_TUNNEL_SIZE
| IPSKB_XFRM_TRANSFORMED
|
1105 if (sock_owned_by_user(sk
)) {
1107 ret
= NET_XMIT_DROP
;
1111 /* The user-space may change the connection status for the user-space
1112 * provided socket at run time: we must check it under the socket lock
1114 if (tunnel
->fd
>= 0 && sk
->sk_state
!= TCP_ESTABLISHED
) {
1116 ret
= NET_XMIT_DROP
;
1120 /* Get routing info from the tunnel socket */
1122 skb_dst_set(skb
, dst_clone(__sk_dst_check(sk
, 0)));
1125 fl
= &inet
->cork
.fl
;
1126 switch (tunnel
->encap
) {
1127 case L2TP_ENCAPTYPE_UDP
:
1128 /* Setup UDP header */
1129 __skb_push(skb
, sizeof(*uh
));
1130 skb_reset_transport_header(skb
);
1132 uh
->source
= inet
->inet_sport
;
1133 uh
->dest
= inet
->inet_dport
;
1134 udp_len
= uhlen
+ hdr_len
+ data_len
;
1135 uh
->len
= htons(udp_len
);
1137 /* Calculate UDP checksum if configured to do so */
1138 #if IS_ENABLED(CONFIG_IPV6)
1139 if (l2tp_sk_is_v6(sk
))
1140 udp6_set_csum(udp_get_no_check6_tx(sk
),
1141 skb
, &inet6_sk(sk
)->saddr
,
1142 &sk
->sk_v6_daddr
, udp_len
);
1145 udp_set_csum(sk
->sk_no_check_tx
, skb
, inet
->inet_saddr
,
1146 inet
->inet_daddr
, udp_len
);
1149 case L2TP_ENCAPTYPE_IP
:
1153 l2tp_xmit_core(session
, skb
, fl
, data_len
);
1159 EXPORT_SYMBOL_GPL(l2tp_xmit_skb
);
1161 /*****************************************************************************
1162 * Tinnel and session create/destroy.
1163 *****************************************************************************/
1165 /* Tunnel socket destruct hook.
1166 * The tunnel context is deleted only when all session sockets have been
1169 static void l2tp_tunnel_destruct(struct sock
*sk
)
1171 struct l2tp_tunnel
*tunnel
= l2tp_tunnel(sk
);
1176 l2tp_info(tunnel
, L2TP_MSG_CONTROL
, "%s: closing...\n", tunnel
->name
);
1178 /* Disable udp encapsulation */
1179 switch (tunnel
->encap
) {
1180 case L2TP_ENCAPTYPE_UDP
:
1181 /* No longer an encapsulation socket. See net/ipv4/udp.c */
1182 (udp_sk(sk
))->encap_type
= 0;
1183 (udp_sk(sk
))->encap_rcv
= NULL
;
1184 (udp_sk(sk
))->encap_destroy
= NULL
;
1186 case L2TP_ENCAPTYPE_IP
:
1190 /* Remove hooks into tunnel socket */
1191 sk
->sk_destruct
= tunnel
->old_sk_destruct
;
1192 sk
->sk_user_data
= NULL
;
1194 /* Call the original destructor */
1195 if (sk
->sk_destruct
)
1196 (*sk
->sk_destruct
)(sk
);
1198 kfree_rcu(tunnel
, rcu
);
1203 /* When the tunnel is closed, all the attached sessions need to go too.
1205 void l2tp_tunnel_closeall(struct l2tp_tunnel
*tunnel
)
1208 struct hlist_node
*walk
;
1209 struct hlist_node
*tmp
;
1210 struct l2tp_session
*session
;
1212 BUG_ON(tunnel
== NULL
);
1214 l2tp_info(tunnel
, L2TP_MSG_CONTROL
, "%s: closing all sessions...\n",
1217 write_lock_bh(&tunnel
->hlist_lock
);
1218 tunnel
->acpt_newsess
= false;
1219 for (hash
= 0; hash
< L2TP_HASH_SIZE
; hash
++) {
1221 hlist_for_each_safe(walk
, tmp
, &tunnel
->session_hlist
[hash
]) {
1222 session
= hlist_entry(walk
, struct l2tp_session
, hlist
);
1224 l2tp_info(session
, L2TP_MSG_CONTROL
,
1225 "%s: closing session\n", session
->name
);
1227 hlist_del_init(&session
->hlist
);
1229 if (test_and_set_bit(0, &session
->dead
))
1232 write_unlock_bh(&tunnel
->hlist_lock
);
1234 __l2tp_session_unhash(session
);
1235 l2tp_session_queue_purge(session
);
1237 if (session
->session_close
!= NULL
)
1238 (*session
->session_close
)(session
);
1240 l2tp_session_dec_refcount(session
);
1242 write_lock_bh(&tunnel
->hlist_lock
);
1244 /* Now restart from the beginning of this hash
1245 * chain. We always remove a session from the
1246 * list so we are guaranteed to make forward
1252 write_unlock_bh(&tunnel
->hlist_lock
);
1254 EXPORT_SYMBOL_GPL(l2tp_tunnel_closeall
);
1256 /* Tunnel socket destroy hook for UDP encapsulation */
1257 static void l2tp_udp_encap_destroy(struct sock
*sk
)
1259 struct l2tp_tunnel
*tunnel
= l2tp_tunnel(sk
);
1262 l2tp_tunnel_delete(tunnel
);
1265 /* Workqueue tunnel deletion function */
1266 static void l2tp_tunnel_del_work(struct work_struct
*work
)
1268 struct l2tp_tunnel
*tunnel
= container_of(work
, struct l2tp_tunnel
,
1270 struct sock
*sk
= tunnel
->sock
;
1271 struct socket
*sock
= sk
->sk_socket
;
1272 struct l2tp_net
*pn
;
1274 l2tp_tunnel_closeall(tunnel
);
1276 /* If the tunnel socket was created within the kernel, use
1277 * the sk API to release it here.
1279 if (tunnel
->fd
< 0) {
1281 kernel_sock_shutdown(sock
, SHUT_RDWR
);
1286 /* Remove the tunnel struct from the tunnel list */
1287 pn
= l2tp_pernet(tunnel
->l2tp_net
);
1288 spin_lock_bh(&pn
->l2tp_tunnel_list_lock
);
1289 list_del_rcu(&tunnel
->list
);
1290 spin_unlock_bh(&pn
->l2tp_tunnel_list_lock
);
1292 /* drop initial ref */
1293 l2tp_tunnel_dec_refcount(tunnel
);
1295 /* drop workqueue ref */
1296 l2tp_tunnel_dec_refcount(tunnel
);
1299 /* Create a socket for the tunnel, if one isn't set up by
1300 * userspace. This is used for static tunnels where there is no
1301 * managing L2TP daemon.
1303 * Since we don't want these sockets to keep a namespace alive by
1304 * themselves, we drop the socket's namespace refcount after creation.
1305 * These sockets are freed when the namespace exits using the pernet
1308 static int l2tp_tunnel_sock_create(struct net
*net
,
1311 struct l2tp_tunnel_cfg
*cfg
,
1312 struct socket
**sockp
)
1315 struct socket
*sock
= NULL
;
1316 struct udp_port_cfg udp_conf
;
1318 switch (cfg
->encap
) {
1319 case L2TP_ENCAPTYPE_UDP
:
1320 memset(&udp_conf
, 0, sizeof(udp_conf
));
1322 #if IS_ENABLED(CONFIG_IPV6)
1323 if (cfg
->local_ip6
&& cfg
->peer_ip6
) {
1324 udp_conf
.family
= AF_INET6
;
1325 memcpy(&udp_conf
.local_ip6
, cfg
->local_ip6
,
1326 sizeof(udp_conf
.local_ip6
));
1327 memcpy(&udp_conf
.peer_ip6
, cfg
->peer_ip6
,
1328 sizeof(udp_conf
.peer_ip6
));
1329 udp_conf
.use_udp6_tx_checksums
=
1330 ! cfg
->udp6_zero_tx_checksums
;
1331 udp_conf
.use_udp6_rx_checksums
=
1332 ! cfg
->udp6_zero_rx_checksums
;
1336 udp_conf
.family
= AF_INET
;
1337 udp_conf
.local_ip
= cfg
->local_ip
;
1338 udp_conf
.peer_ip
= cfg
->peer_ip
;
1339 udp_conf
.use_udp_checksums
= cfg
->use_udp_checksums
;
1342 udp_conf
.local_udp_port
= htons(cfg
->local_udp_port
);
1343 udp_conf
.peer_udp_port
= htons(cfg
->peer_udp_port
);
1345 err
= udp_sock_create(net
, &udp_conf
, &sock
);
1351 case L2TP_ENCAPTYPE_IP
:
1352 #if IS_ENABLED(CONFIG_IPV6)
1353 if (cfg
->local_ip6
&& cfg
->peer_ip6
) {
1354 struct sockaddr_l2tpip6 ip6_addr
= {0};
1356 err
= sock_create_kern(net
, AF_INET6
, SOCK_DGRAM
,
1357 IPPROTO_L2TP
, &sock
);
1361 ip6_addr
.l2tp_family
= AF_INET6
;
1362 memcpy(&ip6_addr
.l2tp_addr
, cfg
->local_ip6
,
1363 sizeof(ip6_addr
.l2tp_addr
));
1364 ip6_addr
.l2tp_conn_id
= tunnel_id
;
1365 err
= kernel_bind(sock
, (struct sockaddr
*) &ip6_addr
,
1370 ip6_addr
.l2tp_family
= AF_INET6
;
1371 memcpy(&ip6_addr
.l2tp_addr
, cfg
->peer_ip6
,
1372 sizeof(ip6_addr
.l2tp_addr
));
1373 ip6_addr
.l2tp_conn_id
= peer_tunnel_id
;
1374 err
= kernel_connect(sock
,
1375 (struct sockaddr
*) &ip6_addr
,
1376 sizeof(ip6_addr
), 0);
1382 struct sockaddr_l2tpip ip_addr
= {0};
1384 err
= sock_create_kern(net
, AF_INET
, SOCK_DGRAM
,
1385 IPPROTO_L2TP
, &sock
);
1389 ip_addr
.l2tp_family
= AF_INET
;
1390 ip_addr
.l2tp_addr
= cfg
->local_ip
;
1391 ip_addr
.l2tp_conn_id
= tunnel_id
;
1392 err
= kernel_bind(sock
, (struct sockaddr
*) &ip_addr
,
1397 ip_addr
.l2tp_family
= AF_INET
;
1398 ip_addr
.l2tp_addr
= cfg
->peer_ip
;
1399 ip_addr
.l2tp_conn_id
= peer_tunnel_id
;
1400 err
= kernel_connect(sock
, (struct sockaddr
*) &ip_addr
,
1401 sizeof(ip_addr
), 0);
1413 if ((err
< 0) && sock
) {
1414 kernel_sock_shutdown(sock
, SHUT_RDWR
);
1422 static struct lock_class_key l2tp_socket_class
;
1424 int l2tp_tunnel_create(struct net
*net
, int fd
, int version
, u32 tunnel_id
, u32 peer_tunnel_id
, struct l2tp_tunnel_cfg
*cfg
, struct l2tp_tunnel
**tunnelp
)
1426 struct l2tp_tunnel
*tunnel
= NULL
;
1428 enum l2tp_encap_type encap
= L2TP_ENCAPTYPE_UDP
;
1433 tunnel
= kzalloc(sizeof(struct l2tp_tunnel
), GFP_KERNEL
);
1434 if (tunnel
== NULL
) {
1439 tunnel
->version
= version
;
1440 tunnel
->tunnel_id
= tunnel_id
;
1441 tunnel
->peer_tunnel_id
= peer_tunnel_id
;
1442 tunnel
->debug
= L2TP_DEFAULT_DEBUG_FLAGS
;
1444 tunnel
->magic
= L2TP_TUNNEL_MAGIC
;
1445 sprintf(&tunnel
->name
[0], "tunl %u", tunnel_id
);
1446 rwlock_init(&tunnel
->hlist_lock
);
1447 tunnel
->acpt_newsess
= true;
1450 tunnel
->debug
= cfg
->debug
;
1452 tunnel
->encap
= encap
;
1454 refcount_set(&tunnel
->ref_count
, 1);
1457 /* Init delete workqueue struct */
1458 INIT_WORK(&tunnel
->del_work
, l2tp_tunnel_del_work
);
1460 INIT_LIST_HEAD(&tunnel
->list
);
1469 EXPORT_SYMBOL_GPL(l2tp_tunnel_create
);
1471 static int l2tp_validate_socket(const struct sock
*sk
, const struct net
*net
,
1472 enum l2tp_encap_type encap
)
1474 if (!net_eq(sock_net(sk
), net
))
1477 if (sk
->sk_type
!= SOCK_DGRAM
)
1478 return -EPROTONOSUPPORT
;
1480 if ((encap
== L2TP_ENCAPTYPE_UDP
&& sk
->sk_protocol
!= IPPROTO_UDP
) ||
1481 (encap
== L2TP_ENCAPTYPE_IP
&& sk
->sk_protocol
!= IPPROTO_L2TP
))
1482 return -EPROTONOSUPPORT
;
1484 if (sk
->sk_user_data
)
1490 int l2tp_tunnel_register(struct l2tp_tunnel
*tunnel
, struct net
*net
,
1491 struct l2tp_tunnel_cfg
*cfg
)
1493 struct l2tp_tunnel
*tunnel_walk
;
1494 struct l2tp_net
*pn
;
1495 struct socket
*sock
;
1499 if (tunnel
->fd
< 0) {
1500 ret
= l2tp_tunnel_sock_create(net
, tunnel
->tunnel_id
,
1501 tunnel
->peer_tunnel_id
, cfg
,
1506 sock
= sockfd_lookup(tunnel
->fd
, &ret
);
1510 ret
= l2tp_validate_socket(sock
->sk
, net
, tunnel
->encap
);
1519 tunnel
->l2tp_net
= net
;
1521 pn
= l2tp_pernet(net
);
1523 spin_lock_bh(&pn
->l2tp_tunnel_list_lock
);
1524 list_for_each_entry(tunnel_walk
, &pn
->l2tp_tunnel_list
, list
) {
1525 if (tunnel_walk
->tunnel_id
== tunnel
->tunnel_id
) {
1526 spin_unlock_bh(&pn
->l2tp_tunnel_list_lock
);
1532 list_add_rcu(&tunnel
->list
, &pn
->l2tp_tunnel_list
);
1533 spin_unlock_bh(&pn
->l2tp_tunnel_list_lock
);
1535 if (tunnel
->encap
== L2TP_ENCAPTYPE_UDP
) {
1536 struct udp_tunnel_sock_cfg udp_cfg
= {
1537 .sk_user_data
= tunnel
,
1538 .encap_type
= UDP_ENCAP_L2TPINUDP
,
1539 .encap_rcv
= l2tp_udp_encap_recv
,
1540 .encap_destroy
= l2tp_udp_encap_destroy
,
1543 setup_udp_tunnel_sock(net
, sock
, &udp_cfg
);
1545 sk
->sk_user_data
= tunnel
;
1548 tunnel
->old_sk_destruct
= sk
->sk_destruct
;
1549 sk
->sk_destruct
= &l2tp_tunnel_destruct
;
1550 lockdep_set_class_and_name(&sk
->sk_lock
.slock
, &l2tp_socket_class
,
1552 sk
->sk_allocation
= GFP_ATOMIC
;
1554 if (tunnel
->fd
>= 0)
1567 EXPORT_SYMBOL_GPL(l2tp_tunnel_register
);
1569 /* This function is used by the netlink TUNNEL_DELETE command.
1571 void l2tp_tunnel_delete(struct l2tp_tunnel
*tunnel
)
1573 if (!test_and_set_bit(0, &tunnel
->dead
)) {
1574 l2tp_tunnel_inc_refcount(tunnel
);
1575 queue_work(l2tp_wq
, &tunnel
->del_work
);
1578 EXPORT_SYMBOL_GPL(l2tp_tunnel_delete
);
1580 /* Really kill the session.
1582 void l2tp_session_free(struct l2tp_session
*session
)
1584 struct l2tp_tunnel
*tunnel
= session
->tunnel
;
1586 BUG_ON(refcount_read(&session
->ref_count
) != 0);
1589 BUG_ON(tunnel
->magic
!= L2TP_TUNNEL_MAGIC
);
1590 l2tp_tunnel_dec_refcount(tunnel
);
1595 EXPORT_SYMBOL_GPL(l2tp_session_free
);
1597 /* Remove an l2tp session from l2tp_core's hash lists.
1598 * Provides a tidyup interface for pseudowire code which can't just route all
1599 * shutdown via. l2tp_session_delete and a pseudowire-specific session_close
1602 void __l2tp_session_unhash(struct l2tp_session
*session
)
1604 struct l2tp_tunnel
*tunnel
= session
->tunnel
;
1606 /* Remove the session from core hashes */
1608 /* Remove from the per-tunnel hash */
1609 write_lock_bh(&tunnel
->hlist_lock
);
1610 hlist_del_init(&session
->hlist
);
1611 write_unlock_bh(&tunnel
->hlist_lock
);
1613 /* For L2TPv3 we have a per-net hash: remove from there, too */
1614 if (tunnel
->version
!= L2TP_HDR_VER_2
) {
1615 struct l2tp_net
*pn
= l2tp_pernet(tunnel
->l2tp_net
);
1616 spin_lock_bh(&pn
->l2tp_session_hlist_lock
);
1617 hlist_del_init_rcu(&session
->global_hlist
);
1618 spin_unlock_bh(&pn
->l2tp_session_hlist_lock
);
1623 EXPORT_SYMBOL_GPL(__l2tp_session_unhash
);
1625 /* This function is used by the netlink SESSION_DELETE command and by
1628 int l2tp_session_delete(struct l2tp_session
*session
)
1630 if (test_and_set_bit(0, &session
->dead
))
1633 __l2tp_session_unhash(session
);
1634 l2tp_session_queue_purge(session
);
1635 if (session
->session_close
!= NULL
)
1636 (*session
->session_close
)(session
);
1638 l2tp_session_dec_refcount(session
);
1642 EXPORT_SYMBOL_GPL(l2tp_session_delete
);
1644 /* We come here whenever a session's send_seq, cookie_len or
1645 * l2specific_len parameters are set.
1647 void l2tp_session_set_header_len(struct l2tp_session
*session
, int version
)
1649 if (version
== L2TP_HDR_VER_2
) {
1650 session
->hdr_len
= 6;
1651 if (session
->send_seq
)
1652 session
->hdr_len
+= 4;
1654 session
->hdr_len
= 4 + session
->cookie_len
+ session
->l2specific_len
+ session
->offset
;
1655 if (session
->tunnel
->encap
== L2TP_ENCAPTYPE_UDP
)
1656 session
->hdr_len
+= 4;
1660 EXPORT_SYMBOL_GPL(l2tp_session_set_header_len
);
1662 struct l2tp_session
*l2tp_session_create(int priv_size
, struct l2tp_tunnel
*tunnel
, u32 session_id
, u32 peer_session_id
, struct l2tp_session_cfg
*cfg
)
1664 struct l2tp_session
*session
;
1666 session
= kzalloc(sizeof(struct l2tp_session
) + priv_size
, GFP_KERNEL
);
1667 if (session
!= NULL
) {
1668 session
->magic
= L2TP_SESSION_MAGIC
;
1669 session
->tunnel
= tunnel
;
1671 session
->session_id
= session_id
;
1672 session
->peer_session_id
= peer_session_id
;
1674 if (tunnel
->version
== L2TP_HDR_VER_2
)
1675 session
->nr_max
= 0xffff;
1677 session
->nr_max
= 0xffffff;
1678 session
->nr_window_size
= session
->nr_max
/ 2;
1679 session
->nr_oos_count_max
= 4;
1681 /* Use NR of first received packet */
1682 session
->reorder_skip
= 1;
1684 sprintf(&session
->name
[0], "sess %u/%u",
1685 tunnel
->tunnel_id
, session
->session_id
);
1687 skb_queue_head_init(&session
->reorder_q
);
1689 INIT_HLIST_NODE(&session
->hlist
);
1690 INIT_HLIST_NODE(&session
->global_hlist
);
1692 /* Inherit debug options from tunnel */
1693 session
->debug
= tunnel
->debug
;
1696 session
->pwtype
= cfg
->pw_type
;
1697 session
->debug
= cfg
->debug
;
1698 session
->mtu
= cfg
->mtu
;
1699 session
->mru
= cfg
->mru
;
1700 session
->send_seq
= cfg
->send_seq
;
1701 session
->recv_seq
= cfg
->recv_seq
;
1702 session
->lns_mode
= cfg
->lns_mode
;
1703 session
->reorder_timeout
= cfg
->reorder_timeout
;
1704 session
->offset
= cfg
->offset
;
1705 session
->l2specific_type
= cfg
->l2specific_type
;
1706 session
->l2specific_len
= cfg
->l2specific_len
;
1707 session
->cookie_len
= cfg
->cookie_len
;
1708 memcpy(&session
->cookie
[0], &cfg
->cookie
[0], cfg
->cookie_len
);
1709 session
->peer_cookie_len
= cfg
->peer_cookie_len
;
1710 memcpy(&session
->peer_cookie
[0], &cfg
->peer_cookie
[0], cfg
->peer_cookie_len
);
1713 if (tunnel
->version
== L2TP_HDR_VER_2
)
1714 session
->build_header
= l2tp_build_l2tpv2_header
;
1716 session
->build_header
= l2tp_build_l2tpv3_header
;
1718 l2tp_session_set_header_len(session
, tunnel
->version
);
1720 refcount_set(&session
->ref_count
, 1);
1725 return ERR_PTR(-ENOMEM
);
1727 EXPORT_SYMBOL_GPL(l2tp_session_create
);
1729 /*****************************************************************************
1731 *****************************************************************************/
1733 static __net_init
int l2tp_init_net(struct net
*net
)
1735 struct l2tp_net
*pn
= net_generic(net
, l2tp_net_id
);
1738 INIT_LIST_HEAD(&pn
->l2tp_tunnel_list
);
1739 spin_lock_init(&pn
->l2tp_tunnel_list_lock
);
1741 for (hash
= 0; hash
< L2TP_HASH_SIZE_2
; hash
++)
1742 INIT_HLIST_HEAD(&pn
->l2tp_session_hlist
[hash
]);
1744 spin_lock_init(&pn
->l2tp_session_hlist_lock
);
1749 static __net_exit
void l2tp_exit_net(struct net
*net
)
1751 struct l2tp_net
*pn
= l2tp_pernet(net
);
1752 struct l2tp_tunnel
*tunnel
= NULL
;
1756 list_for_each_entry_rcu(tunnel
, &pn
->l2tp_tunnel_list
, list
) {
1757 l2tp_tunnel_delete(tunnel
);
1759 rcu_read_unlock_bh();
1761 flush_workqueue(l2tp_wq
);
1764 for (hash
= 0; hash
< L2TP_HASH_SIZE_2
; hash
++)
1765 WARN_ON_ONCE(!hlist_empty(&pn
->l2tp_session_hlist
[hash
]));
1768 static struct pernet_operations l2tp_net_ops
= {
1769 .init
= l2tp_init_net
,
1770 .exit
= l2tp_exit_net
,
1772 .size
= sizeof(struct l2tp_net
),
1775 static int __init
l2tp_init(void)
1779 rc
= register_pernet_device(&l2tp_net_ops
);
1783 l2tp_wq
= alloc_workqueue("l2tp", WQ_UNBOUND
, 0);
1785 pr_err("alloc_workqueue failed\n");
1786 unregister_pernet_device(&l2tp_net_ops
);
1791 pr_info("L2TP core driver, %s\n", L2TP_DRV_VERSION
);
1797 static void __exit
l2tp_exit(void)
1799 unregister_pernet_device(&l2tp_net_ops
);
1801 destroy_workqueue(l2tp_wq
);
1806 module_init(l2tp_init
);
1807 module_exit(l2tp_exit
);
1809 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
1810 MODULE_DESCRIPTION("L2TP core");
1811 MODULE_LICENSE("GPL");
1812 MODULE_VERSION(L2TP_DRV_VERSION
);