1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*****************************************************************************
3 * Linux PPP over L2TP (PPPoX/PPPoL2TP) Sockets
5 * PPPoX --- Generic PPP encapsulation socket family
6 * PPPoL2TP --- PPP over L2TP (RFC 2661)
10 * Authors: James Chapman (jchapman@katalix.com)
12 * Based on original work by Martijn van Oosterhout <kleptog@svana.org>
17 /* This driver handles only L2TP data frames; control frames are handled by a
18 * userspace application.
20 * To send data in an L2TP session, userspace opens a PPPoL2TP socket and
21 * attaches it to a bound UDP socket with local tunnel_id / session_id and
22 * peer tunnel_id / session_id set. Data can then be sent or received using
23 * regular socket sendmsg() / recvmsg() calls. Kernel parameters of the socket
24 * can be read or modified using ioctl() or [gs]etsockopt() calls.
26 * When a PPPoL2TP socket is connected with local and peer session_id values
27 * zero, the socket is treated as a special tunnel management socket.
29 * Here's example userspace code to create a socket for sending/receiving data
30 * over an L2TP session:-
32 * struct sockaddr_pppol2tp sax;
36 * fd = socket(AF_PPPOX, SOCK_DGRAM, PX_PROTO_OL2TP);
38 * sax.sa_family = AF_PPPOX;
39 * sax.sa_protocol = PX_PROTO_OL2TP;
40 * sax.pppol2tp.fd = tunnel_fd; // bound UDP socket
41 * sax.pppol2tp.addr.sin_addr.s_addr = addr->sin_addr.s_addr;
42 * sax.pppol2tp.addr.sin_port = addr->sin_port;
43 * sax.pppol2tp.addr.sin_family = AF_INET;
44 * sax.pppol2tp.s_tunnel = tunnel_id;
45 * sax.pppol2tp.s_session = session_id;
46 * sax.pppol2tp.d_tunnel = peer_tunnel_id;
47 * sax.pppol2tp.d_session = peer_session_id;
49 * session_fd = connect(fd, (struct sockaddr *)&sax, sizeof(sax));
51 * A pppd plugin that allows PPP traffic to be carried over L2TP using
52 * this driver is available from the OpenL2TP project at
53 * http://openl2tp.sourceforge.net.
56 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
58 #include <linux/module.h>
59 #include <linux/string.h>
60 #include <linux/list.h>
61 #include <linux/uaccess.h>
63 #include <linux/kernel.h>
64 #include <linux/spinlock.h>
65 #include <linux/kthread.h>
66 #include <linux/sched.h>
67 #include <linux/slab.h>
68 #include <linux/errno.h>
69 #include <linux/jiffies.h>
71 #include <linux/netdevice.h>
72 #include <linux/net.h>
73 #include <linux/inetdevice.h>
74 #include <linux/skbuff.h>
75 #include <linux/init.h>
77 #include <linux/udp.h>
78 #include <linux/if_pppox.h>
79 #include <linux/if_pppol2tp.h>
81 #include <linux/ppp_channel.h>
82 #include <linux/ppp_defs.h>
83 #include <linux/ppp-ioctl.h>
84 #include <linux/file.h>
85 #include <linux/hash.h>
86 #include <linux/sort.h>
87 #include <linux/proc_fs.h>
88 #include <linux/l2tp.h>
89 #include <linux/nsproxy.h>
90 #include <net/net_namespace.h>
91 #include <net/netns/generic.h>
94 #include <net/inet_common.h>
96 #include <asm/byteorder.h>
97 #include <linux/atomic.h>
99 #include "l2tp_core.h"
101 #define PPPOL2TP_DRV_VERSION "V2.0"
103 /* Space for UDP, L2TP and PPP headers */
104 #define PPPOL2TP_HEADER_OVERHEAD 40
106 /* Number of bytes to build transmit L2TP headers.
107 * Unfortunately the size is different depending on whether sequence numbers
110 #define PPPOL2TP_L2TP_HDR_SIZE_SEQ 10
111 #define PPPOL2TP_L2TP_HDR_SIZE_NOSEQ 6
113 /* Private data of each session. This data lives at the end of struct
114 * l2tp_session, referenced via session->priv[].
116 struct pppol2tp_session {
117 int owner; /* pid that opened the socket */
119 struct mutex sk_lock; /* Protects .sk */
120 struct sock __rcu *sk; /* Pointer to the session PPPoX socket */
121 struct sock *__sk; /* Copy of .sk, for cleanup */
122 struct rcu_head rcu; /* For asynchronous release */
125 static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb);
127 static const struct ppp_channel_ops pppol2tp_chan_ops = {
128 .start_xmit = pppol2tp_xmit,
131 static const struct proto_ops pppol2tp_ops;
133 /* Retrieves the pppol2tp socket associated to a session.
134 * A reference is held on the returned socket, so this function must be paired
137 static struct sock *pppol2tp_session_get_sock(struct l2tp_session *session)
139 struct pppol2tp_session *ps = l2tp_session_priv(session);
143 sk = rcu_dereference(ps->sk);
151 /* Helpers to obtain tunnel/session contexts from sockets.
153 static inline struct l2tp_session *pppol2tp_sock_to_session(struct sock *sk)
155 struct l2tp_session *session;
161 session = (struct l2tp_session *)(sk->sk_user_data);
162 if (session == NULL) {
167 BUG_ON(session->magic != L2TP_SESSION_MAGIC);
173 /*****************************************************************************
174 * Receive data handling
175 *****************************************************************************/
177 /* Receive message. This is the recvmsg for the PPPoL2TP socket.
179 static int pppol2tp_recvmsg(struct socket *sock, struct msghdr *msg,
180 size_t len, int flags)
184 struct sock *sk = sock->sk;
187 if (sk->sk_state & PPPOX_BOUND)
191 skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
192 flags & MSG_DONTWAIT, &err);
198 else if (len < skb->len)
199 msg->msg_flags |= MSG_TRUNC;
201 err = skb_copy_datagram_msg(skb, 0, msg, len);
202 if (likely(err == 0))
210 static void pppol2tp_recv(struct l2tp_session *session, struct sk_buff *skb, int data_len)
212 struct pppol2tp_session *ps = l2tp_session_priv(session);
213 struct sock *sk = NULL;
215 /* If the socket is bound, send it in to PPP's input queue. Otherwise
216 * queue it on the session socket.
219 sk = rcu_dereference(ps->sk);
223 /* If the first two bytes are 0xFF03, consider that it is the PPP's
224 * Address and Control fields and skip them. The L2TP module has always
225 * worked this way, although, in theory, the use of these fields should
226 * be negociated and handled at the PPP layer. These fields are
227 * constant: 0xFF is the All-Stations Address and 0x03 the Unnumbered
228 * Information command with Poll/Final bit set to zero (RFC 1662).
230 if (pskb_may_pull(skb, 2) && skb->data[0] == PPP_ALLSTATIONS &&
231 skb->data[1] == PPP_UI)
234 if (sk->sk_state & PPPOX_BOUND) {
235 struct pppox_sock *po;
237 l2tp_dbg(session, L2TP_MSG_DATA,
238 "%s: recv %d byte data frame, passing to ppp\n",
239 session->name, data_len);
242 ppp_input(&po->chan, skb);
244 l2tp_dbg(session, L2TP_MSG_DATA,
245 "%s: recv %d byte data frame, passing to L2TP socket\n",
246 session->name, data_len);
248 if (sock_queue_rcv_skb(sk, skb) < 0) {
249 atomic_long_inc(&session->stats.rx_errors);
259 l2tp_info(session, L2TP_MSG_DATA, "%s: no socket\n", session->name);
263 /************************************************************************
265 ***********************************************************************/
267 /* This is the sendmsg for the PPPoL2TP pppol2tp_session socket. We come here
268 * when a user application does a sendmsg() on the session socket. L2TP and
269 * PPP headers must be inserted into the user's data.
271 static int pppol2tp_sendmsg(struct socket *sock, struct msghdr *m,
274 struct sock *sk = sock->sk;
277 struct l2tp_session *session;
278 struct l2tp_tunnel *tunnel;
282 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
285 /* Get session and tunnel contexts */
287 session = pppol2tp_sock_to_session(sk);
291 tunnel = session->tunnel;
293 uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0;
295 /* Allocate a socket buffer */
297 skb = sock_wmalloc(sk, NET_SKB_PAD + sizeof(struct iphdr) +
298 uhlen + session->hdr_len +
299 2 + total_len, /* 2 bytes for PPP_ALLSTATIONS & PPP_UI */
304 /* Reserve space for headers. */
305 skb_reserve(skb, NET_SKB_PAD);
306 skb_reset_network_header(skb);
307 skb_reserve(skb, sizeof(struct iphdr));
308 skb_reset_transport_header(skb);
309 skb_reserve(skb, uhlen);
312 skb->data[0] = PPP_ALLSTATIONS;
313 skb->data[1] = PPP_UI;
316 /* Copy user data into skb */
317 error = memcpy_from_msg(skb_put(skb, total_len), m, total_len);
324 l2tp_xmit_skb(session, skb, session->hdr_len);
337 /* Transmit function called by generic PPP driver. Sends PPP frame
338 * over PPPoL2TP socket.
340 * This is almost the same as pppol2tp_sendmsg(), but rather than
341 * being called with a msghdr from userspace, it is called with a skb
344 * The supplied skb from ppp doesn't have enough headroom for the
345 * insertion of L2TP, UDP and IP headers so we need to allocate more
346 * headroom in the skb. This will create a cloned skb. But we must be
347 * careful in the error case because the caller will expect to free
348 * the skb it supplied, not our cloned skb. So we take care to always
349 * leave the original skb unfreed if we return an error.
351 static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
353 struct sock *sk = (struct sock *)chan->private;
354 struct l2tp_session *session;
355 struct l2tp_tunnel *tunnel;
358 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
361 /* Get session and tunnel contexts from the socket */
362 session = pppol2tp_sock_to_session(sk);
366 tunnel = session->tunnel;
368 uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0;
369 headroom = NET_SKB_PAD +
370 sizeof(struct iphdr) + /* IP header */
371 uhlen + /* UDP header (if L2TP_ENCAPTYPE_UDP) */
372 session->hdr_len + /* L2TP header */
373 2; /* 2 bytes for PPP_ALLSTATIONS & PPP_UI */
374 if (skb_cow_head(skb, headroom))
377 /* Setup PPP header */
379 skb->data[0] = PPP_ALLSTATIONS;
380 skb->data[1] = PPP_UI;
383 l2tp_xmit_skb(session, skb, session->hdr_len);
393 /* Free the original skb */
398 /*****************************************************************************
399 * Session (and tunnel control) socket create/destroy.
400 *****************************************************************************/
402 static void pppol2tp_put_sk(struct rcu_head *head)
404 struct pppol2tp_session *ps;
406 ps = container_of(head, typeof(*ps), rcu);
410 /* Really kill the session socket. (Called from sock_put() if
413 static void pppol2tp_session_destruct(struct sock *sk)
415 struct l2tp_session *session = sk->sk_user_data;
417 skb_queue_purge(&sk->sk_receive_queue);
418 skb_queue_purge(&sk->sk_write_queue);
421 sk->sk_user_data = NULL;
422 BUG_ON(session->magic != L2TP_SESSION_MAGIC);
423 l2tp_session_dec_refcount(session);
427 /* Called when the PPPoX socket (session) is closed.
429 static int pppol2tp_release(struct socket *sock)
431 struct sock *sk = sock->sk;
432 struct l2tp_session *session;
440 if (sock_flag(sk, SOCK_DEAD) != 0)
443 pppox_unbind_sock(sk);
445 /* Signal the death of the socket. */
446 sk->sk_state = PPPOX_DEAD;
450 session = pppol2tp_sock_to_session(sk);
452 struct pppol2tp_session *ps;
454 l2tp_session_delete(session);
456 ps = l2tp_session_priv(session);
457 mutex_lock(&ps->sk_lock);
458 ps->__sk = rcu_dereference_protected(ps->sk,
459 lockdep_is_held(&ps->sk_lock));
460 RCU_INIT_POINTER(ps->sk, NULL);
461 mutex_unlock(&ps->sk_lock);
462 call_rcu(&ps->rcu, pppol2tp_put_sk);
464 /* Rely on the sock_put() call at the end of the function for
465 * dropping the reference held by pppol2tp_sock_to_session().
466 * The last reference will be dropped by pppol2tp_put_sk().
472 /* This will delete the session context via
473 * pppol2tp_session_destruct() if the socket's refcnt drops to
485 static struct proto pppol2tp_sk_proto = {
487 .owner = THIS_MODULE,
488 .obj_size = sizeof(struct pppox_sock),
491 static int pppol2tp_backlog_recv(struct sock *sk, struct sk_buff *skb)
495 rc = l2tp_udp_encap_recv(sk, skb);
499 return NET_RX_SUCCESS;
502 /* socket() handler. Initialize a new struct sock.
504 static int pppol2tp_create(struct net *net, struct socket *sock, int kern)
509 sk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, &pppol2tp_sk_proto, kern);
513 sock_init_data(sock, sk);
515 sock->state = SS_UNCONNECTED;
516 sock->ops = &pppol2tp_ops;
518 sk->sk_backlog_rcv = pppol2tp_backlog_recv;
519 sk->sk_protocol = PX_PROTO_OL2TP;
520 sk->sk_family = PF_PPPOX;
521 sk->sk_state = PPPOX_NONE;
522 sk->sk_type = SOCK_STREAM;
523 sk->sk_destruct = pppol2tp_session_destruct;
531 static void pppol2tp_show(struct seq_file *m, void *arg)
533 struct l2tp_session *session = arg;
536 sk = pppol2tp_session_get_sock(session);
538 struct pppox_sock *po = pppox_sk(sk);
540 seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan));
545 static void pppol2tp_session_init(struct l2tp_session *session)
547 struct pppol2tp_session *ps;
549 session->recv_skb = pppol2tp_recv;
550 if (IS_ENABLED(CONFIG_L2TP_DEBUGFS))
551 session->show = pppol2tp_show;
553 ps = l2tp_session_priv(session);
554 mutex_init(&ps->sk_lock);
555 ps->owner = current->pid;
558 struct l2tp_connect_info {
567 static int pppol2tp_sockaddr_get_info(const void *sa, int sa_len,
568 struct l2tp_connect_info *info)
571 case sizeof(struct sockaddr_pppol2tp):
573 const struct sockaddr_pppol2tp *sa_v2in4 = sa;
575 if (sa_v2in4->sa_protocol != PX_PROTO_OL2TP)
579 info->fd = sa_v2in4->pppol2tp.fd;
580 info->tunnel_id = sa_v2in4->pppol2tp.s_tunnel;
581 info->peer_tunnel_id = sa_v2in4->pppol2tp.d_tunnel;
582 info->session_id = sa_v2in4->pppol2tp.s_session;
583 info->peer_session_id = sa_v2in4->pppol2tp.d_session;
587 case sizeof(struct sockaddr_pppol2tpv3):
589 const struct sockaddr_pppol2tpv3 *sa_v3in4 = sa;
591 if (sa_v3in4->sa_protocol != PX_PROTO_OL2TP)
595 info->fd = sa_v3in4->pppol2tp.fd;
596 info->tunnel_id = sa_v3in4->pppol2tp.s_tunnel;
597 info->peer_tunnel_id = sa_v3in4->pppol2tp.d_tunnel;
598 info->session_id = sa_v3in4->pppol2tp.s_session;
599 info->peer_session_id = sa_v3in4->pppol2tp.d_session;
603 case sizeof(struct sockaddr_pppol2tpin6):
605 const struct sockaddr_pppol2tpin6 *sa_v2in6 = sa;
607 if (sa_v2in6->sa_protocol != PX_PROTO_OL2TP)
611 info->fd = sa_v2in6->pppol2tp.fd;
612 info->tunnel_id = sa_v2in6->pppol2tp.s_tunnel;
613 info->peer_tunnel_id = sa_v2in6->pppol2tp.d_tunnel;
614 info->session_id = sa_v2in6->pppol2tp.s_session;
615 info->peer_session_id = sa_v2in6->pppol2tp.d_session;
619 case sizeof(struct sockaddr_pppol2tpv3in6):
621 const struct sockaddr_pppol2tpv3in6 *sa_v3in6 = sa;
623 if (sa_v3in6->sa_protocol != PX_PROTO_OL2TP)
627 info->fd = sa_v3in6->pppol2tp.fd;
628 info->tunnel_id = sa_v3in6->pppol2tp.s_tunnel;
629 info->peer_tunnel_id = sa_v3in6->pppol2tp.d_tunnel;
630 info->session_id = sa_v3in6->pppol2tp.s_session;
631 info->peer_session_id = sa_v3in6->pppol2tp.d_session;
642 /* Rough estimation of the maximum payload size a tunnel can transmit without
643 * fragmenting at the lower IP layer. Assumes L2TPv2 with sequence
644 * numbers and no IP option. Not quite accurate, but the result is mostly
647 static int pppol2tp_tunnel_mtu(const struct l2tp_tunnel *tunnel)
651 mtu = l2tp_tunnel_dst_mtu(tunnel);
652 if (mtu <= PPPOL2TP_HEADER_OVERHEAD)
653 return 1500 - PPPOL2TP_HEADER_OVERHEAD;
655 return mtu - PPPOL2TP_HEADER_OVERHEAD;
658 /* connect() handler. Attach a PPPoX socket to a tunnel UDP socket
660 static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr,
661 int sockaddr_len, int flags)
663 struct sock *sk = sock->sk;
664 struct pppox_sock *po = pppox_sk(sk);
665 struct l2tp_session *session = NULL;
666 struct l2tp_connect_info info;
667 struct l2tp_tunnel *tunnel;
668 struct pppol2tp_session *ps;
669 struct l2tp_session_cfg cfg = { 0, };
670 bool drop_refcnt = false;
671 bool drop_tunnel = false;
672 bool new_session = false;
673 bool new_tunnel = false;
676 error = pppol2tp_sockaddr_get_info(uservaddr, sockaddr_len, &info);
682 /* Check for already bound sockets */
684 if (sk->sk_state & PPPOX_CONNECTED)
687 /* We don't supporting rebinding anyway */
689 if (sk->sk_user_data)
690 goto end; /* socket is already attached */
692 /* Don't bind if tunnel_id is 0 */
697 tunnel = l2tp_tunnel_get(sock_net(sk), info.tunnel_id);
701 /* Special case: create tunnel context if session_id and
702 * peer_session_id is 0. Otherwise look up tunnel using supplied
705 if (!info.session_id && !info.peer_session_id) {
706 if (tunnel == NULL) {
707 struct l2tp_tunnel_cfg tcfg = {
708 .encap = L2TP_ENCAPTYPE_UDP,
712 /* Prevent l2tp_tunnel_register() from trying to set up
720 error = l2tp_tunnel_create(sock_net(sk), info.fd,
723 info.peer_tunnel_id, &tcfg,
728 l2tp_tunnel_inc_refcount(tunnel);
729 error = l2tp_tunnel_register(tunnel, sock_net(sk),
739 /* Error if we can't find the tunnel */
744 /* Error if socket is not prepped */
745 if (tunnel->sock == NULL)
749 if (tunnel->peer_tunnel_id == 0)
750 tunnel->peer_tunnel_id = info.peer_tunnel_id;
752 session = l2tp_tunnel_get_session(tunnel, info.session_id);
756 if (session->pwtype != L2TP_PWTYPE_PPP) {
761 ps = l2tp_session_priv(session);
763 /* Using a pre-existing session is fine as long as it hasn't
764 * been connected yet.
766 mutex_lock(&ps->sk_lock);
767 if (rcu_dereference_protected(ps->sk,
768 lockdep_is_held(&ps->sk_lock)) ||
770 mutex_unlock(&ps->sk_lock);
775 cfg.pw_type = L2TP_PWTYPE_PPP;
777 session = l2tp_session_create(sizeof(struct pppol2tp_session),
778 tunnel, info.session_id,
779 info.peer_session_id, &cfg);
780 if (IS_ERR(session)) {
781 error = PTR_ERR(session);
785 pppol2tp_session_init(session);
786 ps = l2tp_session_priv(session);
787 l2tp_session_inc_refcount(session);
789 mutex_lock(&ps->sk_lock);
790 error = l2tp_session_register(session, tunnel);
792 mutex_unlock(&ps->sk_lock);
800 /* Special case: if source & dest session_id == 0x0000, this
801 * socket is being created to manage the tunnel. Just set up
802 * the internal context for use by ioctl() and sockopt()
805 if ((session->session_id == 0) &&
806 (session->peer_session_id == 0)) {
811 /* The only header we need to worry about is the L2TP
812 * header. This size is different depending on whether
813 * sequence numbers are enabled for the data channel.
815 po->chan.hdrlen = PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
817 po->chan.private = sk;
818 po->chan.ops = &pppol2tp_chan_ops;
819 po->chan.mtu = pppol2tp_tunnel_mtu(tunnel);
821 error = ppp_register_net_channel(sock_net(sk), &po->chan);
823 mutex_unlock(&ps->sk_lock);
828 /* This is how we get the session context from the socket. */
829 sk->sk_user_data = session;
830 rcu_assign_pointer(ps->sk, sk);
831 mutex_unlock(&ps->sk_lock);
833 /* Keep the reference we've grabbed on the session: sk doesn't expect
834 * the session to disappear. pppol2tp_session_destruct() is responsible
839 sk->sk_state = PPPOX_CONNECTED;
840 l2tp_info(session, L2TP_MSG_CONTROL, "%s: created\n",
846 l2tp_session_delete(session);
848 l2tp_tunnel_delete(tunnel);
851 l2tp_session_dec_refcount(session);
853 l2tp_tunnel_dec_refcount(tunnel);
859 #ifdef CONFIG_L2TP_V3
861 /* Called when creating sessions via the netlink interface. */
862 static int pppol2tp_session_create(struct net *net, struct l2tp_tunnel *tunnel,
863 u32 session_id, u32 peer_session_id,
864 struct l2tp_session_cfg *cfg)
867 struct l2tp_session *session;
869 /* Error if tunnel socket is not prepped */
875 /* Allocate and initialize a new session context. */
876 session = l2tp_session_create(sizeof(struct pppol2tp_session),
878 peer_session_id, cfg);
879 if (IS_ERR(session)) {
880 error = PTR_ERR(session);
884 pppol2tp_session_init(session);
886 error = l2tp_session_register(session, tunnel);
898 #endif /* CONFIG_L2TP_V3 */
900 /* getname() support.
902 static int pppol2tp_getname(struct socket *sock, struct sockaddr *uaddr,
907 struct l2tp_session *session;
908 struct l2tp_tunnel *tunnel;
909 struct sock *sk = sock->sk;
910 struct inet_sock *inet;
911 struct pppol2tp_session *pls;
916 if (!(sk->sk_state & PPPOX_CONNECTED))
920 session = pppol2tp_sock_to_session(sk);
924 pls = l2tp_session_priv(session);
925 tunnel = session->tunnel;
927 inet = inet_sk(tunnel->sock);
928 if ((tunnel->version == 2) && (tunnel->sock->sk_family == AF_INET)) {
929 struct sockaddr_pppol2tp sp;
933 sp.sa_family = AF_PPPOX;
934 sp.sa_protocol = PX_PROTO_OL2TP;
935 sp.pppol2tp.fd = tunnel->fd;
936 sp.pppol2tp.pid = pls->owner;
937 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
938 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
939 sp.pppol2tp.s_session = session->session_id;
940 sp.pppol2tp.d_session = session->peer_session_id;
941 sp.pppol2tp.addr.sin_family = AF_INET;
942 sp.pppol2tp.addr.sin_port = inet->inet_dport;
943 sp.pppol2tp.addr.sin_addr.s_addr = inet->inet_daddr;
944 memcpy(uaddr, &sp, len);
945 #if IS_ENABLED(CONFIG_IPV6)
946 } else if ((tunnel->version == 2) &&
947 (tunnel->sock->sk_family == AF_INET6)) {
948 struct sockaddr_pppol2tpin6 sp;
952 sp.sa_family = AF_PPPOX;
953 sp.sa_protocol = PX_PROTO_OL2TP;
954 sp.pppol2tp.fd = tunnel->fd;
955 sp.pppol2tp.pid = pls->owner;
956 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
957 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
958 sp.pppol2tp.s_session = session->session_id;
959 sp.pppol2tp.d_session = session->peer_session_id;
960 sp.pppol2tp.addr.sin6_family = AF_INET6;
961 sp.pppol2tp.addr.sin6_port = inet->inet_dport;
962 memcpy(&sp.pppol2tp.addr.sin6_addr, &tunnel->sock->sk_v6_daddr,
963 sizeof(tunnel->sock->sk_v6_daddr));
964 memcpy(uaddr, &sp, len);
965 } else if ((tunnel->version == 3) &&
966 (tunnel->sock->sk_family == AF_INET6)) {
967 struct sockaddr_pppol2tpv3in6 sp;
971 sp.sa_family = AF_PPPOX;
972 sp.sa_protocol = PX_PROTO_OL2TP;
973 sp.pppol2tp.fd = tunnel->fd;
974 sp.pppol2tp.pid = pls->owner;
975 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
976 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
977 sp.pppol2tp.s_session = session->session_id;
978 sp.pppol2tp.d_session = session->peer_session_id;
979 sp.pppol2tp.addr.sin6_family = AF_INET6;
980 sp.pppol2tp.addr.sin6_port = inet->inet_dport;
981 memcpy(&sp.pppol2tp.addr.sin6_addr, &tunnel->sock->sk_v6_daddr,
982 sizeof(tunnel->sock->sk_v6_daddr));
983 memcpy(uaddr, &sp, len);
985 } else if (tunnel->version == 3) {
986 struct sockaddr_pppol2tpv3 sp;
990 sp.sa_family = AF_PPPOX;
991 sp.sa_protocol = PX_PROTO_OL2TP;
992 sp.pppol2tp.fd = tunnel->fd;
993 sp.pppol2tp.pid = pls->owner;
994 sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
995 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
996 sp.pppol2tp.s_session = session->session_id;
997 sp.pppol2tp.d_session = session->peer_session_id;
998 sp.pppol2tp.addr.sin_family = AF_INET;
999 sp.pppol2tp.addr.sin_port = inet->inet_dport;
1000 sp.pppol2tp.addr.sin_addr.s_addr = inet->inet_daddr;
1001 memcpy(uaddr, &sp, len);
1011 /****************************************************************************
1014 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
1015 * sockets. However, in order to control kernel tunnel features, we allow
1016 * userspace to create a special "tunnel" PPPoX socket which is used for
1017 * control only. Tunnel PPPoX sockets have session_id == 0 and simply allow
1018 * the user application to issue L2TP setsockopt(), getsockopt() and ioctl()
1020 ****************************************************************************/
1022 static void pppol2tp_copy_stats(struct pppol2tp_ioc_stats *dest,
1023 const struct l2tp_stats *stats)
1025 memset(dest, 0, sizeof(*dest));
1027 dest->tx_packets = atomic_long_read(&stats->tx_packets);
1028 dest->tx_bytes = atomic_long_read(&stats->tx_bytes);
1029 dest->tx_errors = atomic_long_read(&stats->tx_errors);
1030 dest->rx_packets = atomic_long_read(&stats->rx_packets);
1031 dest->rx_bytes = atomic_long_read(&stats->rx_bytes);
1032 dest->rx_seq_discards = atomic_long_read(&stats->rx_seq_discards);
1033 dest->rx_oos_packets = atomic_long_read(&stats->rx_oos_packets);
1034 dest->rx_errors = atomic_long_read(&stats->rx_errors);
1037 static int pppol2tp_tunnel_copy_stats(struct pppol2tp_ioc_stats *stats,
1038 struct l2tp_tunnel *tunnel)
1040 struct l2tp_session *session;
1042 if (!stats->session_id) {
1043 pppol2tp_copy_stats(stats, &tunnel->stats);
1047 /* If session_id is set, search the corresponding session in the
1048 * context of this tunnel and record the session's statistics.
1050 session = l2tp_tunnel_get_session(tunnel, stats->session_id);
1054 if (session->pwtype != L2TP_PWTYPE_PPP) {
1055 l2tp_session_dec_refcount(session);
1059 pppol2tp_copy_stats(stats, &session->stats);
1060 l2tp_session_dec_refcount(session);
1065 static int pppol2tp_ioctl(struct socket *sock, unsigned int cmd,
1068 struct pppol2tp_ioc_stats stats;
1069 struct l2tp_session *session;
1074 session = sock->sk->sk_user_data;
1078 /* Not defined for tunnels */
1079 if (!session->session_id && !session->peer_session_id)
1082 if (put_user(0, (int __user *)arg))
1088 session = sock->sk->sk_user_data;
1092 /* Not defined for tunnels */
1093 if (!session->session_id && !session->peer_session_id)
1096 if (!access_ok((int __user *)arg, sizeof(int)))
1100 case PPPIOCGL2TPSTATS:
1101 session = sock->sk->sk_user_data;
1105 /* Session 0 represents the parent tunnel */
1106 if (!session->session_id && !session->peer_session_id) {
1110 if (copy_from_user(&stats, (void __user *)arg,
1114 session_id = stats.session_id;
1115 err = pppol2tp_tunnel_copy_stats(&stats,
1120 stats.session_id = session_id;
1122 pppol2tp_copy_stats(&stats, &session->stats);
1123 stats.session_id = session->session_id;
1125 stats.tunnel_id = session->tunnel->tunnel_id;
1126 stats.using_ipsec = l2tp_tunnel_uses_xfrm(session->tunnel);
1128 if (copy_to_user((void __user *)arg, &stats, sizeof(stats)))
1133 return -ENOIOCTLCMD;
1139 /*****************************************************************************
1140 * setsockopt() / getsockopt() support.
1142 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
1143 * sockets. In order to control kernel tunnel features, we allow userspace to
1144 * create a special "tunnel" PPPoX socket which is used for control only.
1145 * Tunnel PPPoX sockets have session_id == 0 and simply allow the user
1146 * application to issue L2TP setsockopt(), getsockopt() and ioctl() calls.
1147 *****************************************************************************/
1149 /* Tunnel setsockopt() helper.
1151 static int pppol2tp_tunnel_setsockopt(struct sock *sk,
1152 struct l2tp_tunnel *tunnel,
1153 int optname, int val)
1158 case PPPOL2TP_SO_DEBUG:
1159 tunnel->debug = val;
1160 l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: set debug=%x\n",
1161 tunnel->name, tunnel->debug);
1172 /* Session setsockopt helper.
1174 static int pppol2tp_session_setsockopt(struct sock *sk,
1175 struct l2tp_session *session,
1176 int optname, int val)
1181 case PPPOL2TP_SO_RECVSEQ:
1182 if ((val != 0) && (val != 1)) {
1186 session->recv_seq = !!val;
1187 l2tp_info(session, L2TP_MSG_CONTROL,
1188 "%s: set recv_seq=%d\n",
1189 session->name, session->recv_seq);
1192 case PPPOL2TP_SO_SENDSEQ:
1193 if ((val != 0) && (val != 1)) {
1197 session->send_seq = !!val;
1199 struct pppox_sock *po = pppox_sk(sk);
1201 po->chan.hdrlen = val ? PPPOL2TP_L2TP_HDR_SIZE_SEQ :
1202 PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
1204 l2tp_session_set_header_len(session, session->tunnel->version);
1205 l2tp_info(session, L2TP_MSG_CONTROL,
1206 "%s: set send_seq=%d\n",
1207 session->name, session->send_seq);
1210 case PPPOL2TP_SO_LNSMODE:
1211 if ((val != 0) && (val != 1)) {
1215 session->lns_mode = !!val;
1216 l2tp_info(session, L2TP_MSG_CONTROL,
1217 "%s: set lns_mode=%d\n",
1218 session->name, session->lns_mode);
1221 case PPPOL2TP_SO_DEBUG:
1222 session->debug = val;
1223 l2tp_info(session, L2TP_MSG_CONTROL, "%s: set debug=%x\n",
1224 session->name, session->debug);
1227 case PPPOL2TP_SO_REORDERTO:
1228 session->reorder_timeout = msecs_to_jiffies(val);
1229 l2tp_info(session, L2TP_MSG_CONTROL,
1230 "%s: set reorder_timeout=%d\n",
1231 session->name, session->reorder_timeout);
1242 /* Main setsockopt() entry point.
1243 * Does API checks, then calls either the tunnel or session setsockopt
1244 * handler, according to whether the PPPoL2TP socket is a for a regular
1245 * session or the special tunnel type.
1247 static int pppol2tp_setsockopt(struct socket *sock, int level, int optname,
1248 char __user *optval, unsigned int optlen)
1250 struct sock *sk = sock->sk;
1251 struct l2tp_session *session;
1252 struct l2tp_tunnel *tunnel;
1256 if (level != SOL_PPPOL2TP)
1259 if (optlen < sizeof(int))
1262 if (get_user(val, (int __user *)optval))
1266 if (sk->sk_user_data == NULL)
1269 /* Get session context from the socket */
1271 session = pppol2tp_sock_to_session(sk);
1272 if (session == NULL)
1275 /* Special case: if session_id == 0x0000, treat as operation on tunnel
1277 if ((session->session_id == 0) &&
1278 (session->peer_session_id == 0)) {
1279 tunnel = session->tunnel;
1280 err = pppol2tp_tunnel_setsockopt(sk, tunnel, optname, val);
1282 err = pppol2tp_session_setsockopt(sk, session, optname, val);
1290 /* Tunnel getsockopt helper. Called with sock locked.
1292 static int pppol2tp_tunnel_getsockopt(struct sock *sk,
1293 struct l2tp_tunnel *tunnel,
1294 int optname, int *val)
1299 case PPPOL2TP_SO_DEBUG:
1300 *val = tunnel->debug;
1301 l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: get debug=%x\n",
1302 tunnel->name, tunnel->debug);
1313 /* Session getsockopt helper. Called with sock locked.
1315 static int pppol2tp_session_getsockopt(struct sock *sk,
1316 struct l2tp_session *session,
1317 int optname, int *val)
1322 case PPPOL2TP_SO_RECVSEQ:
1323 *val = session->recv_seq;
1324 l2tp_info(session, L2TP_MSG_CONTROL,
1325 "%s: get recv_seq=%d\n", session->name, *val);
1328 case PPPOL2TP_SO_SENDSEQ:
1329 *val = session->send_seq;
1330 l2tp_info(session, L2TP_MSG_CONTROL,
1331 "%s: get send_seq=%d\n", session->name, *val);
1334 case PPPOL2TP_SO_LNSMODE:
1335 *val = session->lns_mode;
1336 l2tp_info(session, L2TP_MSG_CONTROL,
1337 "%s: get lns_mode=%d\n", session->name, *val);
1340 case PPPOL2TP_SO_DEBUG:
1341 *val = session->debug;
1342 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get debug=%d\n",
1343 session->name, *val);
1346 case PPPOL2TP_SO_REORDERTO:
1347 *val = (int)jiffies_to_msecs(session->reorder_timeout);
1348 l2tp_info(session, L2TP_MSG_CONTROL,
1349 "%s: get reorder_timeout=%d\n", session->name, *val);
1359 /* Main getsockopt() entry point.
1360 * Does API checks, then calls either the tunnel or session getsockopt
1361 * handler, according to whether the PPPoX socket is a for a regular session
1362 * or the special tunnel type.
1364 static int pppol2tp_getsockopt(struct socket *sock, int level, int optname,
1365 char __user *optval, int __user *optlen)
1367 struct sock *sk = sock->sk;
1368 struct l2tp_session *session;
1369 struct l2tp_tunnel *tunnel;
1373 if (level != SOL_PPPOL2TP)
1376 if (get_user(len, optlen))
1379 len = min_t(unsigned int, len, sizeof(int));
1385 if (sk->sk_user_data == NULL)
1388 /* Get the session context */
1390 session = pppol2tp_sock_to_session(sk);
1391 if (session == NULL)
1394 /* Special case: if session_id == 0x0000, treat as operation on tunnel */
1395 if ((session->session_id == 0) &&
1396 (session->peer_session_id == 0)) {
1397 tunnel = session->tunnel;
1398 err = pppol2tp_tunnel_getsockopt(sk, tunnel, optname, &val);
1402 err = pppol2tp_session_getsockopt(sk, session, optname, &val);
1408 if (put_user(len, optlen))
1411 if (copy_to_user((void __user *)optval, &val, len))
1422 /*****************************************************************************
1423 * /proc filesystem for debug
1424 * Since the original pppol2tp driver provided /proc/net/pppol2tp for
1425 * L2TPv2, we dump only L2TPv2 tunnels and sessions here.
1426 *****************************************************************************/
1428 static unsigned int pppol2tp_net_id;
1430 #ifdef CONFIG_PROC_FS
1432 struct pppol2tp_seq_data {
1433 struct seq_net_private p;
1434 int tunnel_idx; /* current tunnel */
1435 int session_idx; /* index of session within current tunnel */
1436 struct l2tp_tunnel *tunnel;
1437 struct l2tp_session *session; /* NULL means get next tunnel */
1440 static void pppol2tp_next_tunnel(struct net *net, struct pppol2tp_seq_data *pd)
1442 /* Drop reference taken during previous invocation */
1444 l2tp_tunnel_dec_refcount(pd->tunnel);
1447 pd->tunnel = l2tp_tunnel_get_nth(net, pd->tunnel_idx);
1450 /* Only accept L2TPv2 tunnels */
1451 if (!pd->tunnel || pd->tunnel->version == 2)
1454 l2tp_tunnel_dec_refcount(pd->tunnel);
1458 static void pppol2tp_next_session(struct net *net, struct pppol2tp_seq_data *pd)
1460 /* Drop reference taken during previous invocation */
1462 l2tp_session_dec_refcount(pd->session);
1464 pd->session = l2tp_session_get_nth(pd->tunnel, pd->session_idx);
1467 if (pd->session == NULL) {
1468 pd->session_idx = 0;
1469 pppol2tp_next_tunnel(net, pd);
1473 static void *pppol2tp_seq_start(struct seq_file *m, loff_t *offs)
1475 struct pppol2tp_seq_data *pd = SEQ_START_TOKEN;
1482 BUG_ON(m->private == NULL);
1484 net = seq_file_net(m);
1486 if (pd->tunnel == NULL)
1487 pppol2tp_next_tunnel(net, pd);
1489 pppol2tp_next_session(net, pd);
1491 /* NULL tunnel and session indicates end of list */
1492 if ((pd->tunnel == NULL) && (pd->session == NULL))
1499 static void *pppol2tp_seq_next(struct seq_file *m, void *v, loff_t *pos)
1505 static void pppol2tp_seq_stop(struct seq_file *p, void *v)
1507 struct pppol2tp_seq_data *pd = v;
1509 if (!pd || pd == SEQ_START_TOKEN)
1512 /* Drop reference taken by last invocation of pppol2tp_next_session()
1513 * or pppol2tp_next_tunnel().
1516 l2tp_session_dec_refcount(pd->session);
1520 l2tp_tunnel_dec_refcount(pd->tunnel);
1525 static void pppol2tp_seq_tunnel_show(struct seq_file *m, void *v)
1527 struct l2tp_tunnel *tunnel = v;
1529 seq_printf(m, "\nTUNNEL '%s', %c %d\n",
1531 (tunnel == tunnel->sock->sk_user_data) ? 'Y' : 'N',
1532 refcount_read(&tunnel->ref_count) - 1);
1533 seq_printf(m, " %08x %ld/%ld/%ld %ld/%ld/%ld\n",
1535 atomic_long_read(&tunnel->stats.tx_packets),
1536 atomic_long_read(&tunnel->stats.tx_bytes),
1537 atomic_long_read(&tunnel->stats.tx_errors),
1538 atomic_long_read(&tunnel->stats.rx_packets),
1539 atomic_long_read(&tunnel->stats.rx_bytes),
1540 atomic_long_read(&tunnel->stats.rx_errors));
1543 static void pppol2tp_seq_session_show(struct seq_file *m, void *v)
1545 struct l2tp_session *session = v;
1546 struct l2tp_tunnel *tunnel = session->tunnel;
1547 unsigned char state;
1554 struct inet_sock *inet = inet_sk(tunnel->sock);
1556 ip = ntohl(inet->inet_saddr);
1557 port = ntohs(inet->inet_sport);
1560 sk = pppol2tp_session_get_sock(session);
1562 state = sk->sk_state;
1563 user_data_ok = (session == sk->sk_user_data) ? 'Y' : 'N';
1569 seq_printf(m, " SESSION '%s' %08X/%d %04X/%04X -> %04X/%04X %d %c\n",
1570 session->name, ip, port,
1572 session->session_id,
1573 tunnel->peer_tunnel_id,
1574 session->peer_session_id,
1575 state, user_data_ok);
1576 seq_printf(m, " 0/0/%c/%c/%s %08x %u\n",
1577 session->recv_seq ? 'R' : '-',
1578 session->send_seq ? 'S' : '-',
1579 session->lns_mode ? "LNS" : "LAC",
1581 jiffies_to_msecs(session->reorder_timeout));
1582 seq_printf(m, " %hu/%hu %ld/%ld/%ld %ld/%ld/%ld\n",
1583 session->nr, session->ns,
1584 atomic_long_read(&session->stats.tx_packets),
1585 atomic_long_read(&session->stats.tx_bytes),
1586 atomic_long_read(&session->stats.tx_errors),
1587 atomic_long_read(&session->stats.rx_packets),
1588 atomic_long_read(&session->stats.rx_bytes),
1589 atomic_long_read(&session->stats.rx_errors));
1592 struct pppox_sock *po = pppox_sk(sk);
1594 seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan));
1599 static int pppol2tp_seq_show(struct seq_file *m, void *v)
1601 struct pppol2tp_seq_data *pd = v;
1603 /* display header on line 1 */
1604 if (v == SEQ_START_TOKEN) {
1605 seq_puts(m, "PPPoL2TP driver info, " PPPOL2TP_DRV_VERSION "\n");
1606 seq_puts(m, "TUNNEL name, user-data-ok session-count\n");
1607 seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
1608 seq_puts(m, " SESSION name, addr/port src-tid/sid dest-tid/sid state user-data-ok\n");
1609 seq_puts(m, " mtu/mru/rcvseq/sendseq/lns debug reorderto\n");
1610 seq_puts(m, " nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
1615 pppol2tp_seq_tunnel_show(m, pd->tunnel);
1617 pppol2tp_seq_session_show(m, pd->session);
1623 static const struct seq_operations pppol2tp_seq_ops = {
1624 .start = pppol2tp_seq_start,
1625 .next = pppol2tp_seq_next,
1626 .stop = pppol2tp_seq_stop,
1627 .show = pppol2tp_seq_show,
1629 #endif /* CONFIG_PROC_FS */
1631 /*****************************************************************************
1633 *****************************************************************************/
1635 static __net_init int pppol2tp_init_net(struct net *net)
1637 struct proc_dir_entry *pde;
1640 pde = proc_create_net("pppol2tp", 0444, net->proc_net,
1641 &pppol2tp_seq_ops, sizeof(struct pppol2tp_seq_data));
1651 static __net_exit void pppol2tp_exit_net(struct net *net)
1653 remove_proc_entry("pppol2tp", net->proc_net);
1656 static struct pernet_operations pppol2tp_net_ops = {
1657 .init = pppol2tp_init_net,
1658 .exit = pppol2tp_exit_net,
1659 .id = &pppol2tp_net_id,
1662 /*****************************************************************************
1664 *****************************************************************************/
1666 static const struct proto_ops pppol2tp_ops = {
1668 .owner = THIS_MODULE,
1669 .release = pppol2tp_release,
1670 .bind = sock_no_bind,
1671 .connect = pppol2tp_connect,
1672 .socketpair = sock_no_socketpair,
1673 .accept = sock_no_accept,
1674 .getname = pppol2tp_getname,
1675 .poll = datagram_poll,
1676 .listen = sock_no_listen,
1677 .shutdown = sock_no_shutdown,
1678 .setsockopt = pppol2tp_setsockopt,
1679 .getsockopt = pppol2tp_getsockopt,
1680 .sendmsg = pppol2tp_sendmsg,
1681 .recvmsg = pppol2tp_recvmsg,
1682 .mmap = sock_no_mmap,
1683 .ioctl = pppox_ioctl,
1684 #ifdef CONFIG_COMPAT
1685 .compat_ioctl = pppox_compat_ioctl,
1689 static const struct pppox_proto pppol2tp_proto = {
1690 .create = pppol2tp_create,
1691 .ioctl = pppol2tp_ioctl,
1692 .owner = THIS_MODULE,
1695 #ifdef CONFIG_L2TP_V3
1697 static const struct l2tp_nl_cmd_ops pppol2tp_nl_cmd_ops = {
1698 .session_create = pppol2tp_session_create,
1699 .session_delete = l2tp_session_delete,
1702 #endif /* CONFIG_L2TP_V3 */
1704 static int __init pppol2tp_init(void)
1708 err = register_pernet_device(&pppol2tp_net_ops);
1712 err = proto_register(&pppol2tp_sk_proto, 0);
1714 goto out_unregister_pppol2tp_pernet;
1716 err = register_pppox_proto(PX_PROTO_OL2TP, &pppol2tp_proto);
1718 goto out_unregister_pppol2tp_proto;
1720 #ifdef CONFIG_L2TP_V3
1721 err = l2tp_nl_register_ops(L2TP_PWTYPE_PPP, &pppol2tp_nl_cmd_ops);
1723 goto out_unregister_pppox;
1726 pr_info("PPPoL2TP kernel driver, %s\n", PPPOL2TP_DRV_VERSION);
1731 #ifdef CONFIG_L2TP_V3
1732 out_unregister_pppox:
1733 unregister_pppox_proto(PX_PROTO_OL2TP);
1735 out_unregister_pppol2tp_proto:
1736 proto_unregister(&pppol2tp_sk_proto);
1737 out_unregister_pppol2tp_pernet:
1738 unregister_pernet_device(&pppol2tp_net_ops);
1742 static void __exit pppol2tp_exit(void)
1744 #ifdef CONFIG_L2TP_V3
1745 l2tp_nl_unregister_ops(L2TP_PWTYPE_PPP);
1747 unregister_pppox_proto(PX_PROTO_OL2TP);
1748 proto_unregister(&pppol2tp_sk_proto);
1749 unregister_pernet_device(&pppol2tp_net_ops);
1752 module_init(pppol2tp_init);
1753 module_exit(pppol2tp_exit);
1755 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
1756 MODULE_DESCRIPTION("PPP over L2TP over UDP");
1757 MODULE_LICENSE("GPL");
1758 MODULE_VERSION(PPPOL2TP_DRV_VERSION);
1759 MODULE_ALIAS_NET_PF_PROTO(PF_PPPOX, PX_PROTO_OL2TP);
1760 MODULE_ALIAS_L2TP_PWTYPE(7);