#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>
struct pppol2tp_session {
int owner; /* pid that opened the socket */
- struct sock *sock; /* Pointer to the session
+ struct mutex sk_lock; /* Protects .sk */
+ struct sock __rcu *sk; /* Pointer to the session
* PPPoX socket */
+ struct sock *__sk; /* Copy of .sk, for cleanup */
+ struct rcu_head rcu; /* For asynchronous release */
struct sock *tunnel_sock; /* Pointer to the tunnel UDP
* socket */
int flags; /* accessed by PPPIOCGFLAGS.
static const struct proto_ops pppol2tp_ops;
+/* Retrieves the pppol2tp socket associated to a session.
+ * A reference is held on the returned socket, so this function must be paired
+ * with sock_put().
+ */
+static struct sock *pppol2tp_session_get_sock(struct l2tp_session *session)
+{
+ struct pppol2tp_session *ps = l2tp_session_priv(session);
+ struct sock *sk;
+
+ rcu_read_lock();
+ sk = rcu_dereference(ps->sk);
+ if (sk)
+ sock_hold(sk);
+ rcu_read_unlock();
+
+ return sk;
+}
+
/* Helpers to obtain tunnel/session contexts from sockets.
*/
static inline struct l2tp_session *pppol2tp_sock_to_session(struct sock *sk)
/* If the socket is bound, send it in to PPP's input queue. Otherwise
* queue it on the session socket.
*/
- sk = ps->sock;
+ rcu_read_lock();
+ sk = rcu_dereference(ps->sk);
if (sk == NULL)
goto no_sock;
session->stats.rx_errors++;
kfree_skb(skb);
}
+ rcu_read_unlock();
return;
no_sock:
+ rcu_read_unlock();
PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_INFO,
"%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
***********************************************************************/
* Session (and tunnel control) socket create/destroy.
*****************************************************************************/
+static void pppol2tp_put_sk(struct rcu_head *head)
+{
+ struct pppol2tp_session *ps;
+
+ ps = container_of(head, typeof(*ps), rcu);
+ sock_put(ps->__sk);
+}
+
/* 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 sk_buff *skb;
-
- BUG_ON(session->magic != L2TP_SESSION_MAGIC);
-
- if (session->session_id == 0)
- goto out;
-
- if (sk != NULL) {
- lock_sock(sk);
-
- if (sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND)) {
- pppox_unbind_sock(sk);
- sk->sk_state = PPPOX_DEAD;
- sk->sk_state_change(sk);
- }
-
- /* Purge any queued data */
- skb_queue_purge(&sk->sk_receive_queue);
- skb_queue_purge(&sk->sk_write_queue);
- while ((skb = skb_dequeue(&session->reorder_q))) {
- kfree_skb(skb);
- sock_put(sk);
- }
-
- release_sock(sk);
- }
+ struct pppol2tp_session *ps;
-out:
- return;
+ ps = l2tp_session_priv(session);
+ mutex_lock(&ps->sk_lock);
+ ps->__sk = rcu_dereference_protected(ps->sk,
+ lockdep_is_held(&ps->sk_lock));
+ RCU_INIT_POINTER(ps->sk, NULL);
+ if (ps->__sk)
+ call_rcu(&ps->rcu, pppol2tp_put_sk);
+ mutex_unlock(&ps->sk_lock);
}
/* Really kill the session socket. (Called from sock_put() if
sock_orphan(sk);
sock->sk = NULL;
+ /* If the socket is associated with a session,
+ * l2tp_session_delete will call pppol2tp_session_close which
+ * will drop the session's ref on the socket.
+ */
session = pppol2tp_sock_to_session(sk);
+ if (session) {
+ l2tp_session_delete(session);
+ /* drop the ref obtained by pppol2tp_sock_to_session */
+ sock_put(sk);
+ }
- /* Purge any queued data */
skb_queue_purge(&sk->sk_receive_queue);
skb_queue_purge(&sk->sk_write_queue);
- if (session != NULL) {
- struct sk_buff *skb;
- while ((skb = skb_dequeue(&session->reorder_q))) {
- kfree_skb(skb);
- sock_put(sk);
- }
- sock_put(sk);
- }
release_sock(sk);
static void pppol2tp_show(struct seq_file *m, void *arg)
{
struct l2tp_session *session = arg;
- struct pppol2tp_session *ps = l2tp_session_priv(session);
+ struct sock *sk;
+
+ sk = pppol2tp_session_get_sock(session);
+ if (sk) {
+ struct pppox_sock *po = pppox_sk(sk);
- if (ps) {
- struct pppox_sock *po = pppox_sk(ps->sock);
- if (po)
- seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan));
+ seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan));
+ sock_put(sk);
}
}
#endif
+static void pppol2tp_session_init(struct l2tp_session *session)
+{
+ struct pppol2tp_session *ps;
+ struct dst_entry *dst;
+
+ session->recv_skb = pppol2tp_recv;
+ session->session_close = pppol2tp_session_close;
+#if IS_ENABLED(CONFIG_L2TP_DEBUGFS)
+ session->show = pppol2tp_show;
+#endif
+
+ ps = l2tp_session_priv(session);
+ mutex_init(&ps->sk_lock);
+ ps->tunnel_sock = session->tunnel->sock;
+ ps->owner = current->pid;
+
+ /* If PMTU discovery was enabled, use the MTU that was discovered */
+ dst = sk_dst_get(session->tunnel->sock);
+ if (dst) {
+ u32 pmtu = dst_mtu(dst);
+
+ if (pmtu) {
+ session->mtu = pmtu - PPPOL2TP_HEADER_OVERHEAD;
+ session->mru = pmtu - PPPOL2TP_HEADER_OVERHEAD;
+ }
+ dst_release(dst);
+ }
+}
+
/* connect() handler. Attach a PPPoX socket to a tunnel UDP socket
*/
static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr,
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;
bool drop_refcnt = false;
+ bool drop_tunnel = false;
int ver = 2;
int fd;
if (tunnel_id == 0)
goto end;
- tunnel = l2tp_tunnel_find(sock_net(sk), tunnel_id);
+ tunnel = l2tp_tunnel_get(sock_net(sk), tunnel_id);
+ if (tunnel)
+ drop_tunnel = true;
/* Special case: create tunnel context if session_id and
* peer_session_id is 0. Otherwise look up tunnel using supplied
/* Using a pre-existing session is fine as long as it hasn't
* been connected yet.
*/
- if (ps->sock) {
+ mutex_lock(&ps->sk_lock);
+ if (rcu_dereference_protected(ps->sk,
+ lockdep_is_held(&ps->sk_lock))) {
+ mutex_unlock(&ps->sk_lock);
error = -EEXIST;
goto end;
}
/* consistency checks */
if (ps->tunnel_sock != tunnel->sock) {
+ mutex_unlock(&ps->sk_lock);
error = -EEXIST;
goto end;
}
error = PTR_ERR(session);
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);
+ pppol2tp_session_init(session);
+ ps = l2tp_session_priv(session);
+ l2tp_session_inc_refcount(session);
- if (pmtu != 0)
- session->mtu = session->mru = pmtu -
- PPPOL2TP_HEADER_OVERHEAD;
- dst_release(dst);
+ mutex_lock(&ps->sk_lock);
+ error = l2tp_session_register(session, tunnel);
+ if (error < 0) {
+ mutex_unlock(&ps->sk_lock);
+ kfree(session);
+ goto end;
+ }
+ drop_refcnt = true;
}
/* Special case: if source & dest session_id == 0x0000, this
po->chan.mtu = session->mtu;
error = ppp_register_net_channel(sock_net(sk), &po->chan);
- if (error)
+ if (error) {
+ mutex_unlock(&ps->sk_lock);
goto end;
+ }
out_no_ppp:
/* This is how we get the session context from the socket. */
+ sock_hold(sk);
sk->sk_user_data = session;
+ rcu_assign_pointer(ps->sk, sk);
+ mutex_unlock(&ps->sk_lock);
+
+ /* Keep the reference we've grabbed on the session: sk doesn't expect
+ * the session to disappear. pppol2tp_session_destruct() is responsible
+ * for dropping it.
+ */
+ drop_refcnt = false;
+
sk->sk_state = PPPOX_CONNECTED;
PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
"%s: created\n", session->name);
end:
if (drop_refcnt)
l2tp_session_dec_refcount(session);
+ if (drop_tunnel)
+ l2tp_tunnel_dec_refcount(tunnel);
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)
+/* Called when creating sessions via the netlink interface. */
+static int pppol2tp_session_create(struct net *net, struct l2tp_tunnel *tunnel,
+ 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;
+ if (!tunnel->sock) {
+ error = -ENOENT;
+ goto err;
+ }
/* Default MTU values. */
if (cfg->mtu == 0)
peer_session_id, cfg);
if (IS_ERR(session)) {
error = PTR_ERR(session);
- goto out;
+ goto err;
}
- ps = l2tp_session_priv(session);
- ps->tunnel_sock = tunnel->sock;
+ pppol2tp_session_init(session);
- PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
- "%s: created\n", session->name);
+ error = l2tp_session_register(session, tunnel);
+ if (error < 0)
+ goto err_sess;
- error = 0;
+ return 0;
-out:
+err_sess:
+ kfree(session);
+err:
return error;
}
-/* Called when deleting sessions via the netlink interface.
- */
-static int pppol2tp_session_delete(struct l2tp_session *session)
-{
- struct pppol2tp_session *ps = l2tp_session_priv(session);
-
- if (ps->sock == NULL)
- l2tp_session_dec_refcount(session);
-
- return 0;
-}
-
#endif /* CONFIG_L2TP_V3 */
/* getname() support.
"%s: pppol2tp_session_ioctl(cmd=%#x, arg=%#lx)\n",
session->name, cmd, arg);
- sk = ps->sock;
- sock_hold(sk);
+ sk = pppol2tp_session_get_sock(session);
+ if (!sk)
+ return -EBADR;
switch (cmd) {
case SIOCGIFMTU:
int optname, int val)
{
int err = 0;
- struct pppol2tp_session *ps = l2tp_session_priv(session);
switch (optname) {
case PPPOL2TP_SO_RECVSEQ:
}
session->send_seq = val ? -1 : 0;
{
- struct sock *ssk = ps->sock;
- struct pppox_sock *po = pppox_sk(ssk);
+ struct pppox_sock *po = pppox_sk(sk);
+
po->chan.hdrlen = val ? PPPOL2TP_L2TP_HDR_SIZE_SEQ :
PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
}
{
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);
+ unsigned char state;
+ char user_data_ok;
+ struct sock *sk;
u32 ip = 0;
u16 port = 0;
port = ntohs(inet->inet_sport);
}
+ sk = pppol2tp_session_get_sock(session);
+ if (sk) {
+ state = sk->sk_state;
+ user_data_ok = (session == sk->sk_user_data) ? 'Y' : 'N';
+ } else {
+ state = 0;
+ user_data_ok = 'N';
+ }
+
seq_printf(m, " SESSION '%s' %08X/%d %04X/%04X -> "
"%04X/%04X %d %c\n",
session->name, ip, port,
session->session_id,
tunnel->peer_tunnel_id,
session->peer_session_id,
- ps->sock->sk_state,
- (session == ps->sock->sk_user_data) ?
- 'Y' : 'N');
+ state, user_data_ok);
seq_printf(m, " %d/%d/%c/%c/%s %08x %u\n",
session->mtu, session->mru,
session->recv_seq ? 'R' : '-',
(unsigned long long)session->stats.rx_bytes,
(unsigned long long)session->stats.rx_errors);
- if (po)
+ if (sk) {
+ struct pppox_sock *po = pppox_sk(sk);
+
seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan));
+ sock_put(sk);
+ }
}
static int pppol2tp_seq_show(struct seq_file *m, void *v)
static const struct l2tp_nl_cmd_ops pppol2tp_nl_cmd_ops = {
.session_create = pppol2tp_session_create,
- .session_delete = pppol2tp_session_delete,
+ .session_delete = l2tp_session_delete,
};
#endif /* CONFIG_L2TP_V3 */
git.openpandora.org / pandora-kernel.git / blobdiff