1 files changed, 52 insertions, 42 deletions

diff --git a/net/l2tp/l2tp_ppp.c b/net/l2tp/l2tp_ppp.c
index 36cc56fd0418..861b255a2d51 100644
--- a/net/l2tp/l2tp_ppp.c
+++ b/net/l2tp/l2tp_ppp.c
@@ -450,6 +450,10 @@ static void pppol2tp_session_close(struct l2tp_session *session)
 static void pppol2tp_session_destruct(struct sock *sk)
 {
         struct l2tp_session *session = sk->sk_user_data;
+
+        skb_queue_purge(&sk->sk_receive_queue);
+        skb_queue_purge(&sk->sk_write_queue);
+
         if (session) {
                 sk->sk_user_data = NULL;
                 BUG_ON(session->magic != L2TP_SESSION_MAGIC);
@@ -488,9 +492,6 @@ static int pppol2tp_release(struct socket *sock)
                 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
@@ -582,6 +583,7 @@ static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr,
         int error = 0;
         u32 tunnel_id, peer_tunnel_id;
         u32 session_id, peer_session_id;
+        bool drop_refcnt = false;
         int ver = 2;
         int fd;
 
@@ -683,36 +685,36 @@ static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr,
         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.
+        session = l2tp_session_get(sock_net(sk), tunnel, session_id, false);
+        if (session) {
+                drop_refcnt = true;
+                ps = l2tp_session_priv(session);
+
+                /* Using a pre-existing session is fine as long as it hasn't
+                 * been connected yet.
                  */
-                cfg.mtu = cfg.mru = 1500 - PPPOL2TP_HEADER_OVERHEAD;
+                if (ps->sock) {
+                        error = -EEXIST;
+                        goto end;
+                }
 
-                /* 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;
+                /* consistency checks */
+                if (ps->tunnel_sock != tunnel->sock) {
+                        error = -EEXIST;
                         goto end;
                 }
         } else {
-                ps = l2tp_session_priv(session);
-                error = -EEXIST;
-                if (ps->sock != NULL)
-                        goto end;
+                /* Default MTU must allow space for UDP/L2TP/PPP headers */
+                cfg.mtu = 1500 - PPPOL2TP_HEADER_OVERHEAD;
+                cfg.mru = cfg.mtu;
 
-                /* consistency checks */
-                if (ps->tunnel_sock != tunnel->sock)
+                session = l2tp_session_create(sizeof(struct pppol2tp_session),
+                                              tunnel, session_id,
+                                              peer_session_id, &cfg);
+                if (IS_ERR(session)) {
+                        error = PTR_ERR(session);
                         goto end;
+                }
         }
 
         /* Associate session with its PPPoL2TP socket */
@@ -777,6 +779,8 @@ out_no_ppp:
                   session->name);
 
 end:
+        if (drop_refcnt)
+                l2tp_session_dec_refcount(session);
         release_sock(sk);
 
         return error;
@@ -804,12 +808,6 @@ static int pppol2tp_session_create(struct net *net, u32 tunnel_id, u32 session_i
         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;
@@ -817,12 +815,13 @@ static int pppol2tp_session_create(struct net *net, u32 tunnel_id, u32 session_i
                 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)
+        if (IS_ERR(session)) {
+                error = PTR_ERR(session);
                 goto out;
+        }
 
         ps = l2tp_session_priv(session);
         ps->tunnel_sock = tunnel->sock;
@@ -1140,11 +1139,18 @@ static int pppol2tp_tunnel_ioctl(struct l2tp_tunnel *tunnel,
                 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
+                                l2tp_session_get(sock_net(sk), tunnel,
+                                                 stats.session_id, true);
+
+                        if (session) {
+                                err = pppol2tp_session_ioctl(session, cmd,
+                                                             arg);
+                                if (session->deref)
+                                        session->deref(session);
+                                l2tp_session_dec_refcount(session);
+                        } else {
                                 err = -EBADR;
+                        }
                         break;
                 }
 #ifdef CONFIG_XFRM
@@ -1554,7 +1560,7 @@ static void pppol2tp_next_tunnel(struct net *net, struct pppol2tp_seq_data *pd)
 
 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 = l2tp_session_get_nth(pd->tunnel, pd->session_idx, true);
         pd->session_idx++;
 
         if (pd->session == NULL) {
@@ -1681,10 +1687,14 @@ static int pppol2tp_seq_show(struct seq_file *m, void *v)
 
         /* Show the tunnel or session context.
          */
-        if (pd->session == NULL)
+        if (!pd->session) {
                 pppol2tp_seq_tunnel_show(m, pd->tunnel);
-        else
+        } else {
                 pppol2tp_seq_session_show(m, pd->session);
+                if (pd->session->deref)
+                        pd->session->deref(pd->session);
+                l2tp_session_dec_refcount(pd->session);
+        }
 
 out:
         return 0;
@@ -1843,4 +1853,4 @@ MODULE_DESCRIPTION("PPP over L2TP over UDP");
 MODULE_LICENSE("GPL");
 MODULE_VERSION(PPPOL2TP_DRV_VERSION);
 MODULE_ALIAS_NET_PF_PROTO(PF_PPPOX, PX_PROTO_OL2TP);
-MODULE_ALIAS_L2TP_PWTYPE(11);
+MODULE_ALIAS_L2TP_PWTYPE(7);