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-rw-r--r--kernel/net/l2tp/l2tp_ppp.c1865
1 files changed, 1865 insertions, 0 deletions
diff --git a/kernel/net/l2tp/l2tp_ppp.c b/kernel/net/l2tp/l2tp_ppp.c
new file mode 100644
index 000000000..e9b0dec56
--- /dev/null
+++ b/kernel/net/l2tp/l2tp_ppp.c
@@ -0,0 +1,1865 @@
+/*****************************************************************************
+ * Linux PPP over L2TP (PPPoX/PPPoL2TP) Sockets
+ *
+ * PPPoX --- Generic PPP encapsulation socket family
+ * PPPoL2TP --- PPP over L2TP (RFC 2661)
+ *
+ * Version: 2.0.0
+ *
+ * Authors: James Chapman (jchapman@katalix.com)
+ *
+ * Based on original work by Martijn van Oosterhout <kleptog@svana.org>
+ *
+ * License:
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ */
+
+/* This driver handles only L2TP data frames; control frames are handled by a
+ * userspace application.
+ *
+ * To send data in an L2TP session, userspace opens a PPPoL2TP socket and
+ * attaches it to a bound UDP socket with local tunnel_id / session_id and
+ * peer tunnel_id / session_id set. Data can then be sent or received using
+ * regular socket sendmsg() / recvmsg() calls. Kernel parameters of the socket
+ * can be read or modified using ioctl() or [gs]etsockopt() calls.
+ *
+ * When a PPPoL2TP socket is connected with local and peer session_id values
+ * zero, the socket is treated as a special tunnel management socket.
+ *
+ * Here's example userspace code to create a socket for sending/receiving data
+ * over an L2TP session:-
+ *
+ * struct sockaddr_pppol2tp sax;
+ * int fd;
+ * int session_fd;
+ *
+ * fd = socket(AF_PPPOX, SOCK_DGRAM, PX_PROTO_OL2TP);
+ *
+ * sax.sa_family = AF_PPPOX;
+ * sax.sa_protocol = PX_PROTO_OL2TP;
+ * sax.pppol2tp.fd = tunnel_fd; // bound UDP socket
+ * sax.pppol2tp.addr.sin_addr.s_addr = addr->sin_addr.s_addr;
+ * sax.pppol2tp.addr.sin_port = addr->sin_port;
+ * sax.pppol2tp.addr.sin_family = AF_INET;
+ * sax.pppol2tp.s_tunnel = tunnel_id;
+ * sax.pppol2tp.s_session = session_id;
+ * sax.pppol2tp.d_tunnel = peer_tunnel_id;
+ * sax.pppol2tp.d_session = peer_session_id;
+ *
+ * session_fd = connect(fd, (struct sockaddr *)&sax, sizeof(sax));
+ *
+ * A pppd plugin that allows PPP traffic to be carried over L2TP using
+ * this driver is available from the OpenL2TP project at
+ * http://openl2tp.sourceforge.net.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/list.h>
+#include <linux/uaccess.h>
+
+#include <linux/kernel.h>
+#include <linux/spinlock.h>
+#include <linux/kthread.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <linux/jiffies.h>
+
+#include <linux/netdevice.h>
+#include <linux/net.h>
+#include <linux/inetdevice.h>
+#include <linux/skbuff.h>
+#include <linux/init.h>
+#include <linux/ip.h>
+#include <linux/udp.h>
+#include <linux/if_pppox.h>
+#include <linux/if_pppol2tp.h>
+#include <net/sock.h>
+#include <linux/ppp_channel.h>
+#include <linux/ppp_defs.h>
+#include <linux/ppp-ioctl.h>
+#include <linux/file.h>
+#include <linux/hash.h>
+#include <linux/sort.h>
+#include <linux/proc_fs.h>
+#include <linux/l2tp.h>
+#include <linux/nsproxy.h>
+#include <net/net_namespace.h>
+#include <net/netns/generic.h>
+#include <net/dst.h>
+#include <net/ip.h>
+#include <net/udp.h>
+#include <net/xfrm.h>
+#include <net/inet_common.h>
+
+#include <asm/byteorder.h>
+#include <linux/atomic.h>
+
+#include "l2tp_core.h"
+
+#define PPPOL2TP_DRV_VERSION "V2.0"
+
+/* Space for UDP, L2TP and PPP headers */
+#define PPPOL2TP_HEADER_OVERHEAD 40
+
+/* Number of bytes to build transmit L2TP headers.
+ * Unfortunately the size is different depending on whether sequence numbers
+ * are enabled.
+ */
+#define PPPOL2TP_L2TP_HDR_SIZE_SEQ 10
+#define PPPOL2TP_L2TP_HDR_SIZE_NOSEQ 6
+
+/* Private data of each session. This data lives at the end of struct
+ * l2tp_session, referenced via session->priv[].
+ */
+struct pppol2tp_session {
+ int owner; /* pid that opened the socket */
+
+ struct sock *sock; /* Pointer to the session
+ * PPPoX socket */
+ struct sock *tunnel_sock; /* Pointer to the tunnel UDP
+ * socket */
+ int flags; /* accessed by PPPIOCGFLAGS.
+ * Unused. */
+};
+
+static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb);
+
+static const struct ppp_channel_ops pppol2tp_chan_ops = {
+ .start_xmit = pppol2tp_xmit,
+};
+
+static const struct proto_ops pppol2tp_ops;
+
+/* Helpers to obtain tunnel/session contexts from sockets.
+ */
+static inline struct l2tp_session *pppol2tp_sock_to_session(struct sock *sk)
+{
+ struct l2tp_session *session;
+
+ if (sk == NULL)
+ return NULL;
+
+ sock_hold(sk);
+ session = (struct l2tp_session *)(sk->sk_user_data);
+ if (session == NULL) {
+ sock_put(sk);
+ goto out;
+ }
+
+ BUG_ON(session->magic != L2TP_SESSION_MAGIC);
+
+out:
+ return session;
+}
+
+/*****************************************************************************
+ * Receive data handling
+ *****************************************************************************/
+
+static int pppol2tp_recv_payload_hook(struct sk_buff *skb)
+{
+ /* Skip PPP header, if present. In testing, Microsoft L2TP clients
+ * don't send the PPP header (PPP header compression enabled), but
+ * other clients can include the header. So we cope with both cases
+ * here. The PPP header is always FF03 when using L2TP.
+ *
+ * Note that skb->data[] isn't dereferenced from a u16 ptr here since
+ * the field may be unaligned.
+ */
+ if (!pskb_may_pull(skb, 2))
+ return 1;
+
+ if ((skb->data[0] == 0xff) && (skb->data[1] == 0x03))
+ skb_pull(skb, 2);
+
+ return 0;
+}
+
+/* Receive message. This is the recvmsg for the PPPoL2TP socket.
+ */
+static int pppol2tp_recvmsg(struct socket *sock, struct msghdr *msg,
+ size_t len, int flags)
+{
+ int err;
+ struct sk_buff *skb;
+ struct sock *sk = sock->sk;
+
+ err = -EIO;
+ if (sk->sk_state & PPPOX_BOUND)
+ goto end;
+
+ err = 0;
+ skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
+ flags & MSG_DONTWAIT, &err);
+ if (!skb)
+ goto end;
+
+ if (len > skb->len)
+ len = skb->len;
+ else if (len < skb->len)
+ msg->msg_flags |= MSG_TRUNC;
+
+ err = skb_copy_datagram_msg(skb, 0, msg, len);
+ if (likely(err == 0))
+ err = len;
+
+ kfree_skb(skb);
+end:
+ return err;
+}
+
+static void pppol2tp_recv(struct l2tp_session *session, struct sk_buff *skb, int data_len)
+{
+ struct pppol2tp_session *ps = l2tp_session_priv(session);
+ struct sock *sk = NULL;
+
+ /* If the socket is bound, send it in to PPP's input queue. Otherwise
+ * queue it on the session socket.
+ */
+ sk = ps->sock;
+ if (sk == NULL)
+ goto no_sock;
+
+ if (sk->sk_state & PPPOX_BOUND) {
+ struct pppox_sock *po;
+ l2tp_dbg(session, PPPOL2TP_MSG_DATA,
+ "%s: recv %d byte data frame, passing to ppp\n",
+ session->name, data_len);
+
+ /* We need to forget all info related to the L2TP packet
+ * gathered in the skb as we are going to reuse the same
+ * skb for the inner packet.
+ * Namely we need to:
+ * - reset xfrm (IPSec) information as it applies to
+ * the outer L2TP packet and not to the inner one
+ * - release the dst to force a route lookup on the inner
+ * IP packet since skb->dst currently points to the dst
+ * of the UDP tunnel
+ * - reset netfilter information as it doesn't apply
+ * to the inner packet either
+ */
+ secpath_reset(skb);
+ skb_dst_drop(skb);
+ nf_reset(skb);
+
+ po = pppox_sk(sk);
+ ppp_input(&po->chan, skb);
+ } else {
+ l2tp_dbg(session, PPPOL2TP_MSG_DATA,
+ "%s: recv %d byte data frame, passing to L2TP socket\n",
+ session->name, data_len);
+
+ if (sock_queue_rcv_skb(sk, skb) < 0) {
+ atomic_long_inc(&session->stats.rx_errors);
+ kfree_skb(skb);
+ }
+ }
+
+ return;
+
+no_sock:
+ l2tp_info(session, PPPOL2TP_MSG_DATA, "%s: no socket\n", session->name);
+ kfree_skb(skb);
+}
+
+static void pppol2tp_session_sock_hold(struct l2tp_session *session)
+{
+ struct pppol2tp_session *ps = l2tp_session_priv(session);
+
+ if (ps->sock)
+ sock_hold(ps->sock);
+}
+
+static void pppol2tp_session_sock_put(struct l2tp_session *session)
+{
+ struct pppol2tp_session *ps = l2tp_session_priv(session);
+
+ if (ps->sock)
+ sock_put(ps->sock);
+}
+
+/************************************************************************
+ * Transmit handling
+ ***********************************************************************/
+
+/* This is the sendmsg for the PPPoL2TP pppol2tp_session socket. We come here
+ * when a user application does a sendmsg() on the session socket. L2TP and
+ * PPP headers must be inserted into the user's data.
+ */
+static int pppol2tp_sendmsg(struct socket *sock, struct msghdr *m,
+ size_t total_len)
+{
+ static const unsigned char ppph[2] = { 0xff, 0x03 };
+ struct sock *sk = sock->sk;
+ struct sk_buff *skb;
+ int error;
+ struct l2tp_session *session;
+ struct l2tp_tunnel *tunnel;
+ struct pppol2tp_session *ps;
+ int uhlen;
+
+ error = -ENOTCONN;
+ if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
+ goto error;
+
+ /* Get session and tunnel contexts */
+ error = -EBADF;
+ session = pppol2tp_sock_to_session(sk);
+ if (session == NULL)
+ goto error;
+
+ ps = l2tp_session_priv(session);
+ tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock);
+ if (tunnel == NULL)
+ goto error_put_sess;
+
+ uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0;
+
+ /* Allocate a socket buffer */
+ error = -ENOMEM;
+ skb = sock_wmalloc(sk, NET_SKB_PAD + sizeof(struct iphdr) +
+ uhlen + session->hdr_len +
+ sizeof(ppph) + total_len,
+ 0, GFP_KERNEL);
+ if (!skb)
+ goto error_put_sess_tun;
+
+ /* Reserve space for headers. */
+ skb_reserve(skb, NET_SKB_PAD);
+ skb_reset_network_header(skb);
+ skb_reserve(skb, sizeof(struct iphdr));
+ skb_reset_transport_header(skb);
+ skb_reserve(skb, uhlen);
+
+ /* Add PPP header */
+ skb->data[0] = ppph[0];
+ skb->data[1] = ppph[1];
+ skb_put(skb, 2);
+
+ /* Copy user data into skb */
+ error = memcpy_from_msg(skb_put(skb, total_len), m, total_len);
+ if (error < 0) {
+ kfree_skb(skb);
+ goto error_put_sess_tun;
+ }
+
+ local_bh_disable();
+ l2tp_xmit_skb(session, skb, session->hdr_len);
+ local_bh_enable();
+
+ sock_put(ps->tunnel_sock);
+ sock_put(sk);
+
+ return total_len;
+
+error_put_sess_tun:
+ sock_put(ps->tunnel_sock);
+error_put_sess:
+ sock_put(sk);
+error:
+ return error;
+}
+
+/* Transmit function called by generic PPP driver. Sends PPP frame
+ * over PPPoL2TP socket.
+ *
+ * This is almost the same as pppol2tp_sendmsg(), but rather than
+ * being called with a msghdr from userspace, it is called with a skb
+ * from the kernel.
+ *
+ * The supplied skb from ppp doesn't have enough headroom for the
+ * insertion of L2TP, UDP and IP headers so we need to allocate more
+ * headroom in the skb. This will create a cloned skb. But we must be
+ * careful in the error case because the caller will expect to free
+ * the skb it supplied, not our cloned skb. So we take care to always
+ * leave the original skb unfreed if we return an error.
+ */
+static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
+{
+ static const u8 ppph[2] = { 0xff, 0x03 };
+ struct sock *sk = (struct sock *) chan->private;
+ struct sock *sk_tun;
+ struct l2tp_session *session;
+ struct l2tp_tunnel *tunnel;
+ struct pppol2tp_session *ps;
+ int uhlen, headroom;
+
+ if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
+ goto abort;
+
+ /* Get session and tunnel contexts from the socket */
+ session = pppol2tp_sock_to_session(sk);
+ if (session == NULL)
+ goto abort;
+
+ ps = l2tp_session_priv(session);
+ sk_tun = ps->tunnel_sock;
+ if (sk_tun == NULL)
+ goto abort_put_sess;
+ tunnel = l2tp_sock_to_tunnel(sk_tun);
+ if (tunnel == NULL)
+ goto abort_put_sess;
+
+ uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0;
+ headroom = NET_SKB_PAD +
+ sizeof(struct iphdr) + /* IP header */
+ uhlen + /* UDP header (if L2TP_ENCAPTYPE_UDP) */
+ session->hdr_len + /* L2TP header */
+ sizeof(ppph); /* PPP header */
+ if (skb_cow_head(skb, headroom))
+ goto abort_put_sess_tun;
+
+ /* Setup PPP header */
+ __skb_push(skb, sizeof(ppph));
+ skb->data[0] = ppph[0];
+ skb->data[1] = ppph[1];
+
+ local_bh_disable();
+ l2tp_xmit_skb(session, skb, session->hdr_len);
+ local_bh_enable();
+
+ sock_put(sk_tun);
+ sock_put(sk);
+ return 1;
+
+abort_put_sess_tun:
+ sock_put(sk_tun);
+abort_put_sess:
+ sock_put(sk);
+abort:
+ /* Free the original skb */
+ kfree_skb(skb);
+ return 1;
+}
+
+/*****************************************************************************
+ * Session (and tunnel control) socket create/destroy.
+ *****************************************************************************/
+
+/* Called by l2tp_core when a session socket is being closed.
+ */
+static void pppol2tp_session_close(struct l2tp_session *session)
+{
+ struct pppol2tp_session *ps = l2tp_session_priv(session);
+ struct sock *sk = ps->sock;
+ struct socket *sock = sk->sk_socket;
+
+ BUG_ON(session->magic != L2TP_SESSION_MAGIC);
+
+ if (sock) {
+ inet_shutdown(sock, 2);
+ /* Don't let the session go away before our socket does */
+ l2tp_session_inc_refcount(session);
+ }
+}
+
+/* Really kill the session socket. (Called from sock_put() if
+ * refcnt == 0.)
+ */
+static void pppol2tp_session_destruct(struct sock *sk)
+{
+ struct l2tp_session *session = sk->sk_user_data;
+ if (session) {
+ sk->sk_user_data = NULL;
+ BUG_ON(session->magic != L2TP_SESSION_MAGIC);
+ l2tp_session_dec_refcount(session);
+ }
+}
+
+/* Called when the PPPoX socket (session) is closed.
+ */
+static int pppol2tp_release(struct socket *sock)
+{
+ struct sock *sk = sock->sk;
+ struct l2tp_session *session;
+ int error;
+
+ if (!sk)
+ return 0;
+
+ error = -EBADF;
+ lock_sock(sk);
+ if (sock_flag(sk, SOCK_DEAD) != 0)
+ goto error;
+
+ pppox_unbind_sock(sk);
+
+ /* Signal the death of the socket. */
+ sk->sk_state = PPPOX_DEAD;
+ sock_orphan(sk);
+ sock->sk = NULL;
+
+ session = pppol2tp_sock_to_session(sk);
+
+ /* Purge any queued data */
+ if (session != NULL) {
+ __l2tp_session_unhash(session);
+ l2tp_session_queue_purge(session);
+ sock_put(sk);
+ }
+ skb_queue_purge(&sk->sk_receive_queue);
+ skb_queue_purge(&sk->sk_write_queue);
+
+ release_sock(sk);
+
+ /* This will delete the session context via
+ * pppol2tp_session_destruct() if the socket's refcnt drops to
+ * zero.
+ */
+ sock_put(sk);
+
+ return 0;
+
+error:
+ release_sock(sk);
+ return error;
+}
+
+static struct proto pppol2tp_sk_proto = {
+ .name = "PPPOL2TP",
+ .owner = THIS_MODULE,
+ .obj_size = sizeof(struct pppox_sock),
+};
+
+static int pppol2tp_backlog_recv(struct sock *sk, struct sk_buff *skb)
+{
+ int rc;
+
+ rc = l2tp_udp_encap_recv(sk, skb);
+ if (rc)
+ kfree_skb(skb);
+
+ return NET_RX_SUCCESS;
+}
+
+/* socket() handler. Initialize a new struct sock.
+ */
+static int pppol2tp_create(struct net *net, struct socket *sock)
+{
+ int error = -ENOMEM;
+ struct sock *sk;
+
+ sk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, &pppol2tp_sk_proto);
+ if (!sk)
+ goto out;
+
+ sock_init_data(sock, sk);
+
+ sock->state = SS_UNCONNECTED;
+ sock->ops = &pppol2tp_ops;
+
+ sk->sk_backlog_rcv = pppol2tp_backlog_recv;
+ sk->sk_protocol = PX_PROTO_OL2TP;
+ sk->sk_family = PF_PPPOX;
+ sk->sk_state = PPPOX_NONE;
+ sk->sk_type = SOCK_STREAM;
+ sk->sk_destruct = pppol2tp_session_destruct;
+
+ error = 0;
+
+out:
+ return error;
+}
+
+#if defined(CONFIG_L2TP_DEBUGFS) || defined(CONFIG_L2TP_DEBUGFS_MODULE)
+static void pppol2tp_show(struct seq_file *m, void *arg)
+{
+ struct l2tp_session *session = arg;
+ struct pppol2tp_session *ps = l2tp_session_priv(session);
+
+ if (ps) {
+ struct pppox_sock *po = pppox_sk(ps->sock);
+ if (po)
+ seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan));
+ }
+}
+#endif
+
+/* connect() handler. Attach a PPPoX socket to a tunnel UDP socket
+ */
+static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr,
+ int sockaddr_len, int flags)
+{
+ struct sock *sk = sock->sk;
+ struct sockaddr_pppol2tp *sp = (struct sockaddr_pppol2tp *) uservaddr;
+ struct pppox_sock *po = pppox_sk(sk);
+ struct l2tp_session *session = NULL;
+ struct l2tp_tunnel *tunnel;
+ struct pppol2tp_session *ps;
+ struct dst_entry *dst;
+ struct l2tp_session_cfg cfg = { 0, };
+ int error = 0;
+ u32 tunnel_id, peer_tunnel_id;
+ u32 session_id, peer_session_id;
+ int ver = 2;
+ int fd;
+
+ lock_sock(sk);
+
+ error = -EINVAL;
+ if (sp->sa_protocol != PX_PROTO_OL2TP)
+ goto end;
+
+ /* Check for already bound sockets */
+ error = -EBUSY;
+ if (sk->sk_state & PPPOX_CONNECTED)
+ goto end;
+
+ /* We don't supporting rebinding anyway */
+ error = -EALREADY;
+ if (sk->sk_user_data)
+ goto end; /* socket is already attached */
+
+ /* Get params from socket address. Handle L2TPv2 and L2TPv3.
+ * This is nasty because there are different sockaddr_pppol2tp
+ * structs for L2TPv2, L2TPv3, over IPv4 and IPv6. We use
+ * the sockaddr size to determine which structure the caller
+ * is using.
+ */
+ peer_tunnel_id = 0;
+ if (sockaddr_len == sizeof(struct sockaddr_pppol2tp)) {
+ fd = sp->pppol2tp.fd;
+ tunnel_id = sp->pppol2tp.s_tunnel;
+ peer_tunnel_id = sp->pppol2tp.d_tunnel;
+ session_id = sp->pppol2tp.s_session;
+ peer_session_id = sp->pppol2tp.d_session;
+ } else if (sockaddr_len == sizeof(struct sockaddr_pppol2tpv3)) {
+ struct sockaddr_pppol2tpv3 *sp3 =
+ (struct sockaddr_pppol2tpv3 *) sp;
+ ver = 3;
+ fd = sp3->pppol2tp.fd;
+ tunnel_id = sp3->pppol2tp.s_tunnel;
+ peer_tunnel_id = sp3->pppol2tp.d_tunnel;
+ session_id = sp3->pppol2tp.s_session;
+ peer_session_id = sp3->pppol2tp.d_session;
+ } else if (sockaddr_len == sizeof(struct sockaddr_pppol2tpin6)) {
+ struct sockaddr_pppol2tpin6 *sp6 =
+ (struct sockaddr_pppol2tpin6 *) sp;
+ fd = sp6->pppol2tp.fd;
+ tunnel_id = sp6->pppol2tp.s_tunnel;
+ peer_tunnel_id = sp6->pppol2tp.d_tunnel;
+ session_id = sp6->pppol2tp.s_session;
+ peer_session_id = sp6->pppol2tp.d_session;
+ } else if (sockaddr_len == sizeof(struct sockaddr_pppol2tpv3in6)) {
+ struct sockaddr_pppol2tpv3in6 *sp6 =
+ (struct sockaddr_pppol2tpv3in6 *) sp;
+ ver = 3;
+ fd = sp6->pppol2tp.fd;
+ tunnel_id = sp6->pppol2tp.s_tunnel;
+ peer_tunnel_id = sp6->pppol2tp.d_tunnel;
+ session_id = sp6->pppol2tp.s_session;
+ peer_session_id = sp6->pppol2tp.d_session;
+ } else {
+ error = -EINVAL;
+ goto end; /* bad socket address */
+ }
+
+ /* Don't bind if tunnel_id is 0 */
+ error = -EINVAL;
+ if (tunnel_id == 0)
+ goto end;
+
+ tunnel = l2tp_tunnel_find(sock_net(sk), tunnel_id);
+
+ /* Special case: create tunnel context if session_id and
+ * peer_session_id is 0. Otherwise look up tunnel using supplied
+ * tunnel id.
+ */
+ if ((session_id == 0) && (peer_session_id == 0)) {
+ if (tunnel == NULL) {
+ struct l2tp_tunnel_cfg tcfg = {
+ .encap = L2TP_ENCAPTYPE_UDP,
+ .debug = 0,
+ };
+ error = l2tp_tunnel_create(sock_net(sk), fd, ver, tunnel_id, peer_tunnel_id, &tcfg, &tunnel);
+ if (error < 0)
+ goto end;
+ }
+ } else {
+ /* Error if we can't find the tunnel */
+ error = -ENOENT;
+ if (tunnel == NULL)
+ goto end;
+
+ /* Error if socket is not prepped */
+ if (tunnel->sock == NULL)
+ goto end;
+ }
+
+ if (tunnel->recv_payload_hook == NULL)
+ tunnel->recv_payload_hook = pppol2tp_recv_payload_hook;
+
+ if (tunnel->peer_tunnel_id == 0)
+ tunnel->peer_tunnel_id = peer_tunnel_id;
+
+ /* Create session if it doesn't already exist. We handle the
+ * case where a session was previously created by the netlink
+ * interface by checking that the session doesn't already have
+ * a socket and its tunnel socket are what we expect. If any
+ * of those checks fail, return EEXIST to the caller.
+ */
+ session = l2tp_session_find(sock_net(sk), tunnel, session_id);
+ if (session == NULL) {
+ /* Default MTU must allow space for UDP/L2TP/PPP
+ * headers.
+ */
+ cfg.mtu = cfg.mru = 1500 - PPPOL2TP_HEADER_OVERHEAD;
+
+ /* Allocate and initialize a new session context. */
+ session = l2tp_session_create(sizeof(struct pppol2tp_session),
+ tunnel, session_id,
+ peer_session_id, &cfg);
+ if (session == NULL) {
+ error = -ENOMEM;
+ goto end;
+ }
+ } else {
+ ps = l2tp_session_priv(session);
+ error = -EEXIST;
+ if (ps->sock != NULL)
+ goto end;
+
+ /* consistency checks */
+ if (ps->tunnel_sock != tunnel->sock)
+ goto end;
+ }
+
+ /* Associate session with its PPPoL2TP socket */
+ ps = l2tp_session_priv(session);
+ ps->owner = current->pid;
+ ps->sock = sk;
+ ps->tunnel_sock = tunnel->sock;
+
+ session->recv_skb = pppol2tp_recv;
+ session->session_close = pppol2tp_session_close;
+#if defined(CONFIG_L2TP_DEBUGFS) || defined(CONFIG_L2TP_DEBUGFS_MODULE)
+ session->show = pppol2tp_show;
+#endif
+
+ /* We need to know each time a skb is dropped from the reorder
+ * queue.
+ */
+ session->ref = pppol2tp_session_sock_hold;
+ session->deref = pppol2tp_session_sock_put;
+
+ /* If PMTU discovery was enabled, use the MTU that was discovered */
+ dst = sk_dst_get(tunnel->sock);
+ if (dst != NULL) {
+ u32 pmtu = dst_mtu(dst);
+
+ if (pmtu != 0)
+ session->mtu = session->mru = pmtu -
+ PPPOL2TP_HEADER_OVERHEAD;
+ dst_release(dst);
+ }
+
+ /* Special case: if source & dest session_id == 0x0000, this
+ * socket is being created to manage the tunnel. Just set up
+ * the internal context for use by ioctl() and sockopt()
+ * handlers.
+ */
+ if ((session->session_id == 0) &&
+ (session->peer_session_id == 0)) {
+ error = 0;
+ goto out_no_ppp;
+ }
+
+ /* The only header we need to worry about is the L2TP
+ * header. This size is different depending on whether
+ * sequence numbers are enabled for the data channel.
+ */
+ po->chan.hdrlen = PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
+
+ po->chan.private = sk;
+ po->chan.ops = &pppol2tp_chan_ops;
+ po->chan.mtu = session->mtu;
+
+ error = ppp_register_net_channel(sock_net(sk), &po->chan);
+ if (error)
+ goto end;
+
+out_no_ppp:
+ /* This is how we get the session context from the socket. */
+ sk->sk_user_data = session;
+ sk->sk_state = PPPOX_CONNECTED;
+ l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: created\n",
+ session->name);
+
+end:
+ release_sock(sk);
+
+ return error;
+}
+
+#ifdef CONFIG_L2TP_V3
+
+/* Called when creating sessions via the netlink interface.
+ */
+static int pppol2tp_session_create(struct net *net, u32 tunnel_id, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg)
+{
+ int error;
+ struct l2tp_tunnel *tunnel;
+ struct l2tp_session *session;
+ struct pppol2tp_session *ps;
+
+ tunnel = l2tp_tunnel_find(net, tunnel_id);
+
+ /* Error if we can't find the tunnel */
+ error = -ENOENT;
+ if (tunnel == NULL)
+ goto out;
+
+ /* Error if tunnel socket is not prepped */
+ if (tunnel->sock == NULL)
+ goto out;
+
+ /* Check that this session doesn't already exist */
+ error = -EEXIST;
+ session = l2tp_session_find(net, tunnel, session_id);
+ if (session != NULL)
+ goto out;
+
+ /* Default MTU values. */
+ if (cfg->mtu == 0)
+ cfg->mtu = 1500 - PPPOL2TP_HEADER_OVERHEAD;
+ if (cfg->mru == 0)
+ cfg->mru = cfg->mtu;
+
+ /* Allocate and initialize a new session context. */
+ error = -ENOMEM;
+ session = l2tp_session_create(sizeof(struct pppol2tp_session),
+ tunnel, session_id,
+ peer_session_id, cfg);
+ if (session == NULL)
+ goto out;
+
+ ps = l2tp_session_priv(session);
+ ps->tunnel_sock = tunnel->sock;
+
+ l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: created\n",
+ session->name);
+
+ error = 0;
+
+out:
+ return error;
+}
+
+#endif /* CONFIG_L2TP_V3 */
+
+/* getname() support.
+ */
+static int pppol2tp_getname(struct socket *sock, struct sockaddr *uaddr,
+ int *usockaddr_len, int peer)
+{
+ int len = 0;
+ int error = 0;
+ struct l2tp_session *session;
+ struct l2tp_tunnel *tunnel;
+ struct sock *sk = sock->sk;
+ struct inet_sock *inet;
+ struct pppol2tp_session *pls;
+
+ error = -ENOTCONN;
+ if (sk == NULL)
+ goto end;
+ if (sk->sk_state != PPPOX_CONNECTED)
+ goto end;
+
+ error = -EBADF;
+ session = pppol2tp_sock_to_session(sk);
+ if (session == NULL)
+ goto end;
+
+ pls = l2tp_session_priv(session);
+ tunnel = l2tp_sock_to_tunnel(pls->tunnel_sock);
+ if (tunnel == NULL) {
+ error = -EBADF;
+ goto end_put_sess;
+ }
+
+ inet = inet_sk(tunnel->sock);
+ if ((tunnel->version == 2) && (tunnel->sock->sk_family == AF_INET)) {
+ struct sockaddr_pppol2tp sp;
+ len = sizeof(sp);
+ memset(&sp, 0, len);
+ sp.sa_family = AF_PPPOX;
+ sp.sa_protocol = PX_PROTO_OL2TP;
+ sp.pppol2tp.fd = tunnel->fd;
+ sp.pppol2tp.pid = pls->owner;
+ sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
+ sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
+ sp.pppol2tp.s_session = session->session_id;
+ sp.pppol2tp.d_session = session->peer_session_id;
+ sp.pppol2tp.addr.sin_family = AF_INET;
+ sp.pppol2tp.addr.sin_port = inet->inet_dport;
+ sp.pppol2tp.addr.sin_addr.s_addr = inet->inet_daddr;
+ memcpy(uaddr, &sp, len);
+#if IS_ENABLED(CONFIG_IPV6)
+ } else if ((tunnel->version == 2) &&
+ (tunnel->sock->sk_family == AF_INET6)) {
+ struct sockaddr_pppol2tpin6 sp;
+
+ len = sizeof(sp);
+ memset(&sp, 0, len);
+ sp.sa_family = AF_PPPOX;
+ sp.sa_protocol = PX_PROTO_OL2TP;
+ sp.pppol2tp.fd = tunnel->fd;
+ sp.pppol2tp.pid = pls->owner;
+ sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
+ sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
+ sp.pppol2tp.s_session = session->session_id;
+ sp.pppol2tp.d_session = session->peer_session_id;
+ sp.pppol2tp.addr.sin6_family = AF_INET6;
+ sp.pppol2tp.addr.sin6_port = inet->inet_dport;
+ memcpy(&sp.pppol2tp.addr.sin6_addr, &tunnel->sock->sk_v6_daddr,
+ sizeof(tunnel->sock->sk_v6_daddr));
+ memcpy(uaddr, &sp, len);
+ } else if ((tunnel->version == 3) &&
+ (tunnel->sock->sk_family == AF_INET6)) {
+ struct sockaddr_pppol2tpv3in6 sp;
+
+ len = sizeof(sp);
+ memset(&sp, 0, len);
+ sp.sa_family = AF_PPPOX;
+ sp.sa_protocol = PX_PROTO_OL2TP;
+ sp.pppol2tp.fd = tunnel->fd;
+ sp.pppol2tp.pid = pls->owner;
+ sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
+ sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
+ sp.pppol2tp.s_session = session->session_id;
+ sp.pppol2tp.d_session = session->peer_session_id;
+ sp.pppol2tp.addr.sin6_family = AF_INET6;
+ sp.pppol2tp.addr.sin6_port = inet->inet_dport;
+ memcpy(&sp.pppol2tp.addr.sin6_addr, &tunnel->sock->sk_v6_daddr,
+ sizeof(tunnel->sock->sk_v6_daddr));
+ memcpy(uaddr, &sp, len);
+#endif
+ } else if (tunnel->version == 3) {
+ struct sockaddr_pppol2tpv3 sp;
+ len = sizeof(sp);
+ memset(&sp, 0, len);
+ sp.sa_family = AF_PPPOX;
+ sp.sa_protocol = PX_PROTO_OL2TP;
+ sp.pppol2tp.fd = tunnel->fd;
+ sp.pppol2tp.pid = pls->owner;
+ sp.pppol2tp.s_tunnel = tunnel->tunnel_id;
+ sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id;
+ sp.pppol2tp.s_session = session->session_id;
+ sp.pppol2tp.d_session = session->peer_session_id;
+ sp.pppol2tp.addr.sin_family = AF_INET;
+ sp.pppol2tp.addr.sin_port = inet->inet_dport;
+ sp.pppol2tp.addr.sin_addr.s_addr = inet->inet_daddr;
+ memcpy(uaddr, &sp, len);
+ }
+
+ *usockaddr_len = len;
+
+ sock_put(pls->tunnel_sock);
+end_put_sess:
+ sock_put(sk);
+ error = 0;
+
+end:
+ return error;
+}
+
+/****************************************************************************
+ * ioctl() handlers.
+ *
+ * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
+ * sockets. However, in order to control kernel tunnel features, we allow
+ * userspace to create a special "tunnel" PPPoX socket which is used for
+ * control only. Tunnel PPPoX sockets have session_id == 0 and simply allow
+ * the user application to issue L2TP setsockopt(), getsockopt() and ioctl()
+ * calls.
+ ****************************************************************************/
+
+static void pppol2tp_copy_stats(struct pppol2tp_ioc_stats *dest,
+ struct l2tp_stats *stats)
+{
+ dest->tx_packets = atomic_long_read(&stats->tx_packets);
+ dest->tx_bytes = atomic_long_read(&stats->tx_bytes);
+ dest->tx_errors = atomic_long_read(&stats->tx_errors);
+ dest->rx_packets = atomic_long_read(&stats->rx_packets);
+ dest->rx_bytes = atomic_long_read(&stats->rx_bytes);
+ dest->rx_seq_discards = atomic_long_read(&stats->rx_seq_discards);
+ dest->rx_oos_packets = atomic_long_read(&stats->rx_oos_packets);
+ dest->rx_errors = atomic_long_read(&stats->rx_errors);
+}
+
+/* Session ioctl helper.
+ */
+static int pppol2tp_session_ioctl(struct l2tp_session *session,
+ unsigned int cmd, unsigned long arg)
+{
+ struct ifreq ifr;
+ int err = 0;
+ struct sock *sk;
+ int val = (int) arg;
+ struct pppol2tp_session *ps = l2tp_session_priv(session);
+ struct l2tp_tunnel *tunnel = session->tunnel;
+ struct pppol2tp_ioc_stats stats;
+
+ l2tp_dbg(session, PPPOL2TP_MSG_CONTROL,
+ "%s: pppol2tp_session_ioctl(cmd=%#x, arg=%#lx)\n",
+ session->name, cmd, arg);
+
+ sk = ps->sock;
+ sock_hold(sk);
+
+ switch (cmd) {
+ case SIOCGIFMTU:
+ err = -ENXIO;
+ if (!(sk->sk_state & PPPOX_CONNECTED))
+ break;
+
+ err = -EFAULT;
+ if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq)))
+ break;
+ ifr.ifr_mtu = session->mtu;
+ if (copy_to_user((void __user *) arg, &ifr, sizeof(struct ifreq)))
+ break;
+
+ l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: get mtu=%d\n",
+ session->name, session->mtu);
+ err = 0;
+ break;
+
+ case SIOCSIFMTU:
+ err = -ENXIO;
+ if (!(sk->sk_state & PPPOX_CONNECTED))
+ break;
+
+ err = -EFAULT;
+ if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq)))
+ break;
+
+ session->mtu = ifr.ifr_mtu;
+
+ l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: set mtu=%d\n",
+ session->name, session->mtu);
+ err = 0;
+ break;
+
+ case PPPIOCGMRU:
+ err = -ENXIO;
+ if (!(sk->sk_state & PPPOX_CONNECTED))
+ break;
+
+ err = -EFAULT;
+ if (put_user(session->mru, (int __user *) arg))
+ break;
+
+ l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: get mru=%d\n",
+ session->name, session->mru);
+ err = 0;
+ break;
+
+ case PPPIOCSMRU:
+ err = -ENXIO;
+ if (!(sk->sk_state & PPPOX_CONNECTED))
+ break;
+
+ err = -EFAULT;
+ if (get_user(val, (int __user *) arg))
+ break;
+
+ session->mru = val;
+ l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: set mru=%d\n",
+ session->name, session->mru);
+ err = 0;
+ break;
+
+ case PPPIOCGFLAGS:
+ err = -EFAULT;
+ if (put_user(ps->flags, (int __user *) arg))
+ break;
+
+ l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: get flags=%d\n",
+ session->name, ps->flags);
+ err = 0;
+ break;
+
+ case PPPIOCSFLAGS:
+ err = -EFAULT;
+ if (get_user(val, (int __user *) arg))
+ break;
+ ps->flags = val;
+ l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: set flags=%d\n",
+ session->name, ps->flags);
+ err = 0;
+ break;
+
+ case PPPIOCGL2TPSTATS:
+ err = -ENXIO;
+ if (!(sk->sk_state & PPPOX_CONNECTED))
+ break;
+
+ memset(&stats, 0, sizeof(stats));
+ stats.tunnel_id = tunnel->tunnel_id;
+ stats.session_id = session->session_id;
+ pppol2tp_copy_stats(&stats, &session->stats);
+ if (copy_to_user((void __user *) arg, &stats,
+ sizeof(stats)))
+ break;
+ l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: get L2TP stats\n",
+ session->name);
+ err = 0;
+ break;
+
+ default:
+ err = -ENOSYS;
+ break;
+ }
+
+ sock_put(sk);
+
+ return err;
+}
+
+/* Tunnel ioctl helper.
+ *
+ * Note the special handling for PPPIOCGL2TPSTATS below. If the ioctl data
+ * specifies a session_id, the session ioctl handler is called. This allows an
+ * application to retrieve session stats via a tunnel socket.
+ */
+static int pppol2tp_tunnel_ioctl(struct l2tp_tunnel *tunnel,
+ unsigned int cmd, unsigned long arg)
+{
+ int err = 0;
+ struct sock *sk;
+ struct pppol2tp_ioc_stats stats;
+
+ l2tp_dbg(tunnel, PPPOL2TP_MSG_CONTROL,
+ "%s: pppol2tp_tunnel_ioctl(cmd=%#x, arg=%#lx)\n",
+ tunnel->name, cmd, arg);
+
+ sk = tunnel->sock;
+ sock_hold(sk);
+
+ switch (cmd) {
+ case PPPIOCGL2TPSTATS:
+ err = -ENXIO;
+ if (!(sk->sk_state & PPPOX_CONNECTED))
+ break;
+
+ if (copy_from_user(&stats, (void __user *) arg,
+ sizeof(stats))) {
+ err = -EFAULT;
+ break;
+ }
+ if (stats.session_id != 0) {
+ /* resend to session ioctl handler */
+ struct l2tp_session *session =
+ l2tp_session_find(sock_net(sk), tunnel, stats.session_id);
+ if (session != NULL)
+ err = pppol2tp_session_ioctl(session, cmd, arg);
+ else
+ err = -EBADR;
+ break;
+ }
+#ifdef CONFIG_XFRM
+ stats.using_ipsec = (sk->sk_policy[0] || sk->sk_policy[1]) ? 1 : 0;
+#endif
+ pppol2tp_copy_stats(&stats, &tunnel->stats);
+ if (copy_to_user((void __user *) arg, &stats, sizeof(stats))) {
+ err = -EFAULT;
+ break;
+ }
+ l2tp_info(tunnel, PPPOL2TP_MSG_CONTROL, "%s: get L2TP stats\n",
+ tunnel->name);
+ err = 0;
+ break;
+
+ default:
+ err = -ENOSYS;
+ break;
+ }
+
+ sock_put(sk);
+
+ return err;
+}
+
+/* Main ioctl() handler.
+ * Dispatch to tunnel or session helpers depending on the socket.
+ */
+static int pppol2tp_ioctl(struct socket *sock, unsigned int cmd,
+ unsigned long arg)
+{
+ struct sock *sk = sock->sk;
+ struct l2tp_session *session;
+ struct l2tp_tunnel *tunnel;
+ struct pppol2tp_session *ps;
+ int err;
+
+ if (!sk)
+ return 0;
+
+ err = -EBADF;
+ if (sock_flag(sk, SOCK_DEAD) != 0)
+ goto end;
+
+ err = -ENOTCONN;
+ if ((sk->sk_user_data == NULL) ||
+ (!(sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND))))
+ goto end;
+
+ /* Get session context from the socket */
+ err = -EBADF;
+ session = pppol2tp_sock_to_session(sk);
+ if (session == NULL)
+ goto end;
+
+ /* Special case: if session's session_id is zero, treat ioctl as a
+ * tunnel ioctl
+ */
+ ps = l2tp_session_priv(session);
+ if ((session->session_id == 0) &&
+ (session->peer_session_id == 0)) {
+ err = -EBADF;
+ tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock);
+ if (tunnel == NULL)
+ goto end_put_sess;
+
+ err = pppol2tp_tunnel_ioctl(tunnel, cmd, arg);
+ sock_put(ps->tunnel_sock);
+ goto end_put_sess;
+ }
+
+ err = pppol2tp_session_ioctl(session, cmd, arg);
+
+end_put_sess:
+ sock_put(sk);
+end:
+ return err;
+}
+
+/*****************************************************************************
+ * setsockopt() / getsockopt() support.
+ *
+ * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP
+ * sockets. In order to control kernel tunnel features, we allow userspace to
+ * create a special "tunnel" PPPoX socket which is used for control only.
+ * Tunnel PPPoX sockets have session_id == 0 and simply allow the user
+ * application to issue L2TP setsockopt(), getsockopt() and ioctl() calls.
+ *****************************************************************************/
+
+/* Tunnel setsockopt() helper.
+ */
+static int pppol2tp_tunnel_setsockopt(struct sock *sk,
+ struct l2tp_tunnel *tunnel,
+ int optname, int val)
+{
+ int err = 0;
+
+ switch (optname) {
+ case PPPOL2TP_SO_DEBUG:
+ tunnel->debug = val;
+ l2tp_info(tunnel, PPPOL2TP_MSG_CONTROL, "%s: set debug=%x\n",
+ tunnel->name, tunnel->debug);
+ break;
+
+ default:
+ err = -ENOPROTOOPT;
+ break;
+ }
+
+ return err;
+}
+
+/* Session setsockopt helper.
+ */
+static int pppol2tp_session_setsockopt(struct sock *sk,
+ struct l2tp_session *session,
+ int optname, int val)
+{
+ int err = 0;
+ struct pppol2tp_session *ps = l2tp_session_priv(session);
+
+ switch (optname) {
+ case PPPOL2TP_SO_RECVSEQ:
+ if ((val != 0) && (val != 1)) {
+ err = -EINVAL;
+ break;
+ }
+ session->recv_seq = val ? -1 : 0;
+ l2tp_info(session, PPPOL2TP_MSG_CONTROL,
+ "%s: set recv_seq=%d\n",
+ session->name, session->recv_seq);
+ break;
+
+ case PPPOL2TP_SO_SENDSEQ:
+ if ((val != 0) && (val != 1)) {
+ err = -EINVAL;
+ break;
+ }
+ session->send_seq = val ? -1 : 0;
+ {
+ struct sock *ssk = ps->sock;
+ struct pppox_sock *po = pppox_sk(ssk);
+ po->chan.hdrlen = val ? PPPOL2TP_L2TP_HDR_SIZE_SEQ :
+ PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
+ }
+ l2tp_session_set_header_len(session, session->tunnel->version);
+ l2tp_info(session, PPPOL2TP_MSG_CONTROL,
+ "%s: set send_seq=%d\n",
+ session->name, session->send_seq);
+ break;
+
+ case PPPOL2TP_SO_LNSMODE:
+ if ((val != 0) && (val != 1)) {
+ err = -EINVAL;
+ break;
+ }
+ session->lns_mode = val ? -1 : 0;
+ l2tp_info(session, PPPOL2TP_MSG_CONTROL,
+ "%s: set lns_mode=%d\n",
+ session->name, session->lns_mode);
+ break;
+
+ case PPPOL2TP_SO_DEBUG:
+ session->debug = val;
+ l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: set debug=%x\n",
+ session->name, session->debug);
+ break;
+
+ case PPPOL2TP_SO_REORDERTO:
+ session->reorder_timeout = msecs_to_jiffies(val);
+ l2tp_info(session, PPPOL2TP_MSG_CONTROL,
+ "%s: set reorder_timeout=%d\n",
+ session->name, session->reorder_timeout);
+ break;
+
+ default:
+ err = -ENOPROTOOPT;
+ break;
+ }
+
+ return err;
+}
+
+/* Main setsockopt() entry point.
+ * Does API checks, then calls either the tunnel or session setsockopt
+ * handler, according to whether the PPPoL2TP socket is a for a regular
+ * session or the special tunnel type.
+ */
+static int pppol2tp_setsockopt(struct socket *sock, int level, int optname,
+ char __user *optval, unsigned int optlen)
+{
+ struct sock *sk = sock->sk;
+ struct l2tp_session *session;
+ struct l2tp_tunnel *tunnel;
+ struct pppol2tp_session *ps;
+ int val;
+ int err;
+
+ if (level != SOL_PPPOL2TP)
+ return -EINVAL;
+
+ if (optlen < sizeof(int))
+ return -EINVAL;
+
+ if (get_user(val, (int __user *)optval))
+ return -EFAULT;
+
+ err = -ENOTCONN;
+ if (sk->sk_user_data == NULL)
+ goto end;
+
+ /* Get session context from the socket */
+ err = -EBADF;
+ session = pppol2tp_sock_to_session(sk);
+ if (session == NULL)
+ goto end;
+
+ /* Special case: if session_id == 0x0000, treat as operation on tunnel
+ */
+ ps = l2tp_session_priv(session);
+ if ((session->session_id == 0) &&
+ (session->peer_session_id == 0)) {
+ err = -EBADF;
+ tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock);
+ if (tunnel == NULL)
+ goto end_put_sess;
+
+ err = pppol2tp_tunnel_setsockopt(sk, tunnel, optname, val);
+ sock_put(ps->tunnel_sock);
+ } else
+ err = pppol2tp_session_setsockopt(sk, session, optname, val);
+
+ err = 0;
+
+end_put_sess:
+ sock_put(sk);
+end:
+ return err;
+}
+
+/* Tunnel getsockopt helper. Called with sock locked.
+ */
+static int pppol2tp_tunnel_getsockopt(struct sock *sk,
+ struct l2tp_tunnel *tunnel,
+ int optname, int *val)
+{
+ int err = 0;
+
+ switch (optname) {
+ case PPPOL2TP_SO_DEBUG:
+ *val = tunnel->debug;
+ l2tp_info(tunnel, PPPOL2TP_MSG_CONTROL, "%s: get debug=%x\n",
+ tunnel->name, tunnel->debug);
+ break;
+
+ default:
+ err = -ENOPROTOOPT;
+ break;
+ }
+
+ return err;
+}
+
+/* Session getsockopt helper. Called with sock locked.
+ */
+static int pppol2tp_session_getsockopt(struct sock *sk,
+ struct l2tp_session *session,
+ int optname, int *val)
+{
+ int err = 0;
+
+ switch (optname) {
+ case PPPOL2TP_SO_RECVSEQ:
+ *val = session->recv_seq;
+ l2tp_info(session, PPPOL2TP_MSG_CONTROL,
+ "%s: get recv_seq=%d\n", session->name, *val);
+ break;
+
+ case PPPOL2TP_SO_SENDSEQ:
+ *val = session->send_seq;
+ l2tp_info(session, PPPOL2TP_MSG_CONTROL,
+ "%s: get send_seq=%d\n", session->name, *val);
+ break;
+
+ case PPPOL2TP_SO_LNSMODE:
+ *val = session->lns_mode;
+ l2tp_info(session, PPPOL2TP_MSG_CONTROL,
+ "%s: get lns_mode=%d\n", session->name, *val);
+ break;
+
+ case PPPOL2TP_SO_DEBUG:
+ *val = session->debug;
+ l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: get debug=%d\n",
+ session->name, *val);
+ break;
+
+ case PPPOL2TP_SO_REORDERTO:
+ *val = (int) jiffies_to_msecs(session->reorder_timeout);
+ l2tp_info(session, PPPOL2TP_MSG_CONTROL,
+ "%s: get reorder_timeout=%d\n", session->name, *val);
+ break;
+
+ default:
+ err = -ENOPROTOOPT;
+ }
+
+ return err;
+}
+
+/* Main getsockopt() entry point.
+ * Does API checks, then calls either the tunnel or session getsockopt
+ * handler, according to whether the PPPoX socket is a for a regular session
+ * or the special tunnel type.
+ */
+static int pppol2tp_getsockopt(struct socket *sock, int level, int optname,
+ char __user *optval, int __user *optlen)
+{
+ struct sock *sk = sock->sk;
+ struct l2tp_session *session;
+ struct l2tp_tunnel *tunnel;
+ int val, len;
+ int err;
+ struct pppol2tp_session *ps;
+
+ if (level != SOL_PPPOL2TP)
+ return -EINVAL;
+
+ if (get_user(len, optlen))
+ return -EFAULT;
+
+ len = min_t(unsigned int, len, sizeof(int));
+
+ if (len < 0)
+ return -EINVAL;
+
+ err = -ENOTCONN;
+ if (sk->sk_user_data == NULL)
+ goto end;
+
+ /* Get the session context */
+ err = -EBADF;
+ session = pppol2tp_sock_to_session(sk);
+ if (session == NULL)
+ goto end;
+
+ /* Special case: if session_id == 0x0000, treat as operation on tunnel */
+ ps = l2tp_session_priv(session);
+ if ((session->session_id == 0) &&
+ (session->peer_session_id == 0)) {
+ err = -EBADF;
+ tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock);
+ if (tunnel == NULL)
+ goto end_put_sess;
+
+ err = pppol2tp_tunnel_getsockopt(sk, tunnel, optname, &val);
+ sock_put(ps->tunnel_sock);
+ } else
+ err = pppol2tp_session_getsockopt(sk, session, optname, &val);
+
+ err = -EFAULT;
+ if (put_user(len, optlen))
+ goto end_put_sess;
+
+ if (copy_to_user((void __user *) optval, &val, len))
+ goto end_put_sess;
+
+ err = 0;
+
+end_put_sess:
+ sock_put(sk);
+end:
+ return err;
+}
+
+/*****************************************************************************
+ * /proc filesystem for debug
+ * Since the original pppol2tp driver provided /proc/net/pppol2tp for
+ * L2TPv2, we dump only L2TPv2 tunnels and sessions here.
+ *****************************************************************************/
+
+static unsigned int pppol2tp_net_id;
+
+#ifdef CONFIG_PROC_FS
+
+struct pppol2tp_seq_data {
+ struct seq_net_private p;
+ int tunnel_idx; /* current tunnel */
+ int session_idx; /* index of session within current tunnel */
+ struct l2tp_tunnel *tunnel;
+ struct l2tp_session *session; /* NULL means get next tunnel */
+};
+
+static void pppol2tp_next_tunnel(struct net *net, struct pppol2tp_seq_data *pd)
+{
+ for (;;) {
+ pd->tunnel = l2tp_tunnel_find_nth(net, pd->tunnel_idx);
+ pd->tunnel_idx++;
+
+ if (pd->tunnel == NULL)
+ break;
+
+ /* Ignore L2TPv3 tunnels */
+ if (pd->tunnel->version < 3)
+ break;
+ }
+}
+
+static void pppol2tp_next_session(struct net *net, struct pppol2tp_seq_data *pd)
+{
+ pd->session = l2tp_session_find_nth(pd->tunnel, pd->session_idx);
+ pd->session_idx++;
+
+ if (pd->session == NULL) {
+ pd->session_idx = 0;
+ pppol2tp_next_tunnel(net, pd);
+ }
+}
+
+static void *pppol2tp_seq_start(struct seq_file *m, loff_t *offs)
+{
+ struct pppol2tp_seq_data *pd = SEQ_START_TOKEN;
+ loff_t pos = *offs;
+ struct net *net;
+
+ if (!pos)
+ goto out;
+
+ BUG_ON(m->private == NULL);
+ pd = m->private;
+ net = seq_file_net(m);
+
+ if (pd->tunnel == NULL)
+ pppol2tp_next_tunnel(net, pd);
+ else
+ pppol2tp_next_session(net, pd);
+
+ /* NULL tunnel and session indicates end of list */
+ if ((pd->tunnel == NULL) && (pd->session == NULL))
+ pd = NULL;
+
+out:
+ return pd;
+}
+
+static void *pppol2tp_seq_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ (*pos)++;
+ return NULL;
+}
+
+static void pppol2tp_seq_stop(struct seq_file *p, void *v)
+{
+ /* nothing to do */
+}
+
+static void pppol2tp_seq_tunnel_show(struct seq_file *m, void *v)
+{
+ struct l2tp_tunnel *tunnel = v;
+
+ seq_printf(m, "\nTUNNEL '%s', %c %d\n",
+ tunnel->name,
+ (tunnel == tunnel->sock->sk_user_data) ? 'Y' : 'N',
+ atomic_read(&tunnel->ref_count) - 1);
+ seq_printf(m, " %08x %ld/%ld/%ld %ld/%ld/%ld\n",
+ tunnel->debug,
+ atomic_long_read(&tunnel->stats.tx_packets),
+ atomic_long_read(&tunnel->stats.tx_bytes),
+ atomic_long_read(&tunnel->stats.tx_errors),
+ atomic_long_read(&tunnel->stats.rx_packets),
+ atomic_long_read(&tunnel->stats.rx_bytes),
+ atomic_long_read(&tunnel->stats.rx_errors));
+}
+
+static void pppol2tp_seq_session_show(struct seq_file *m, void *v)
+{
+ struct l2tp_session *session = v;
+ struct l2tp_tunnel *tunnel = session->tunnel;
+ struct pppol2tp_session *ps = l2tp_session_priv(session);
+ struct pppox_sock *po = pppox_sk(ps->sock);
+ u32 ip = 0;
+ u16 port = 0;
+
+ if (tunnel->sock) {
+ struct inet_sock *inet = inet_sk(tunnel->sock);
+ ip = ntohl(inet->inet_saddr);
+ port = ntohs(inet->inet_sport);
+ }
+
+ seq_printf(m, " SESSION '%s' %08X/%d %04X/%04X -> "
+ "%04X/%04X %d %c\n",
+ session->name, ip, port,
+ tunnel->tunnel_id,
+ session->session_id,
+ tunnel->peer_tunnel_id,
+ session->peer_session_id,
+ ps->sock->sk_state,
+ (session == ps->sock->sk_user_data) ?
+ 'Y' : 'N');
+ seq_printf(m, " %d/%d/%c/%c/%s %08x %u\n",
+ session->mtu, session->mru,
+ session->recv_seq ? 'R' : '-',
+ session->send_seq ? 'S' : '-',
+ session->lns_mode ? "LNS" : "LAC",
+ session->debug,
+ jiffies_to_msecs(session->reorder_timeout));
+ seq_printf(m, " %hu/%hu %ld/%ld/%ld %ld/%ld/%ld\n",
+ session->nr, session->ns,
+ atomic_long_read(&session->stats.tx_packets),
+ atomic_long_read(&session->stats.tx_bytes),
+ atomic_long_read(&session->stats.tx_errors),
+ atomic_long_read(&session->stats.rx_packets),
+ atomic_long_read(&session->stats.rx_bytes),
+ atomic_long_read(&session->stats.rx_errors));
+
+ if (po)
+ seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan));
+}
+
+static int pppol2tp_seq_show(struct seq_file *m, void *v)
+{
+ struct pppol2tp_seq_data *pd = v;
+
+ /* display header on line 1 */
+ if (v == SEQ_START_TOKEN) {
+ seq_puts(m, "PPPoL2TP driver info, " PPPOL2TP_DRV_VERSION "\n");
+ seq_puts(m, "TUNNEL name, user-data-ok session-count\n");
+ seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
+ seq_puts(m, " SESSION name, addr/port src-tid/sid "
+ "dest-tid/sid state user-data-ok\n");
+ seq_puts(m, " mtu/mru/rcvseq/sendseq/lns debug reorderto\n");
+ seq_puts(m, " nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
+ goto out;
+ }
+
+ /* Show the tunnel or session context.
+ */
+ if (pd->session == NULL)
+ pppol2tp_seq_tunnel_show(m, pd->tunnel);
+ else
+ pppol2tp_seq_session_show(m, pd->session);
+
+out:
+ return 0;
+}
+
+static const struct seq_operations pppol2tp_seq_ops = {
+ .start = pppol2tp_seq_start,
+ .next = pppol2tp_seq_next,
+ .stop = pppol2tp_seq_stop,
+ .show = pppol2tp_seq_show,
+};
+
+/* Called when our /proc file is opened. We allocate data for use when
+ * iterating our tunnel / session contexts and store it in the private
+ * data of the seq_file.
+ */
+static int pppol2tp_proc_open(struct inode *inode, struct file *file)
+{
+ return seq_open_net(inode, file, &pppol2tp_seq_ops,
+ sizeof(struct pppol2tp_seq_data));
+}
+
+static const struct file_operations pppol2tp_proc_fops = {
+ .owner = THIS_MODULE,
+ .open = pppol2tp_proc_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release_net,
+};
+
+#endif /* CONFIG_PROC_FS */
+
+/*****************************************************************************
+ * Network namespace
+ *****************************************************************************/
+
+static __net_init int pppol2tp_init_net(struct net *net)
+{
+ struct proc_dir_entry *pde;
+ int err = 0;
+
+ pde = proc_create("pppol2tp", S_IRUGO, net->proc_net,
+ &pppol2tp_proc_fops);
+ if (!pde) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+out:
+ return err;
+}
+
+static __net_exit void pppol2tp_exit_net(struct net *net)
+{
+ remove_proc_entry("pppol2tp", net->proc_net);
+}
+
+static struct pernet_operations pppol2tp_net_ops = {
+ .init = pppol2tp_init_net,
+ .exit = pppol2tp_exit_net,
+ .id = &pppol2tp_net_id,
+};
+
+/*****************************************************************************
+ * Init and cleanup
+ *****************************************************************************/
+
+static const struct proto_ops pppol2tp_ops = {
+ .family = AF_PPPOX,
+ .owner = THIS_MODULE,
+ .release = pppol2tp_release,
+ .bind = sock_no_bind,
+ .connect = pppol2tp_connect,
+ .socketpair = sock_no_socketpair,
+ .accept = sock_no_accept,
+ .getname = pppol2tp_getname,
+ .poll = datagram_poll,
+ .listen = sock_no_listen,
+ .shutdown = sock_no_shutdown,
+ .setsockopt = pppol2tp_setsockopt,
+ .getsockopt = pppol2tp_getsockopt,
+ .sendmsg = pppol2tp_sendmsg,
+ .recvmsg = pppol2tp_recvmsg,
+ .mmap = sock_no_mmap,
+ .ioctl = pppox_ioctl,
+};
+
+static const struct pppox_proto pppol2tp_proto = {
+ .create = pppol2tp_create,
+ .ioctl = pppol2tp_ioctl,
+ .owner = THIS_MODULE,
+};
+
+#ifdef CONFIG_L2TP_V3
+
+static const struct l2tp_nl_cmd_ops pppol2tp_nl_cmd_ops = {
+ .session_create = pppol2tp_session_create,
+ .session_delete = l2tp_session_delete,
+};
+
+#endif /* CONFIG_L2TP_V3 */
+
+static int __init pppol2tp_init(void)
+{
+ int err;
+
+ err = register_pernet_device(&pppol2tp_net_ops);
+ if (err)
+ goto out;
+
+ err = proto_register(&pppol2tp_sk_proto, 0);
+ if (err)
+ goto out_unregister_pppol2tp_pernet;
+
+ err = register_pppox_proto(PX_PROTO_OL2TP, &pppol2tp_proto);
+ if (err)
+ goto out_unregister_pppol2tp_proto;
+
+#ifdef CONFIG_L2TP_V3
+ err = l2tp_nl_register_ops(L2TP_PWTYPE_PPP, &pppol2tp_nl_cmd_ops);
+ if (err)
+ goto out_unregister_pppox;
+#endif
+
+ pr_info("PPPoL2TP kernel driver, %s\n", PPPOL2TP_DRV_VERSION);
+
+out:
+ return err;
+
+#ifdef CONFIG_L2TP_V3
+out_unregister_pppox:
+ unregister_pppox_proto(PX_PROTO_OL2TP);
+#endif
+out_unregister_pppol2tp_proto:
+ proto_unregister(&pppol2tp_sk_proto);
+out_unregister_pppol2tp_pernet:
+ unregister_pernet_device(&pppol2tp_net_ops);
+ goto out;
+}
+
+static void __exit pppol2tp_exit(void)
+{
+#ifdef CONFIG_L2TP_V3
+ l2tp_nl_unregister_ops(L2TP_PWTYPE_PPP);
+#endif
+ unregister_pppox_proto(PX_PROTO_OL2TP);
+ proto_unregister(&pppol2tp_sk_proto);
+ unregister_pernet_device(&pppol2tp_net_ops);
+}
+
+module_init(pppol2tp_init);
+module_exit(pppol2tp_exit);
+
+MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
+MODULE_DESCRIPTION("PPP over L2TP over UDP");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(PPPOL2TP_DRV_VERSION);
+MODULE_ALIAS("pppox-proto-" __stringify(PX_PROTO_OL2TP));