};
static void l2tp_session_set_header_len(struct l2tp_session *session, int version);
-static void l2tp_tunnel_free(struct l2tp_tunnel *tunnel);
static void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel);
-static inline struct l2tp_net *l2tp_pernet(struct net *net)
+static inline struct l2tp_net *l2tp_pernet(const struct net *net)
{
BUG_ON(!net);
}
-/* Tunnel reference counts. Incremented per session that is added to
- * the tunnel.
- */
-static inline void l2tp_tunnel_inc_refcount_1(struct l2tp_tunnel *tunnel)
-{
- atomic_inc(&tunnel->ref_count);
-}
-
-static inline void l2tp_tunnel_dec_refcount_1(struct l2tp_tunnel *tunnel)
-{
- if (atomic_dec_and_test(&tunnel->ref_count))
- l2tp_tunnel_free(tunnel);
-}
-#ifdef L2TP_REFCNT_DEBUG
-#define l2tp_tunnel_inc_refcount(_t) do { \
- printk(KERN_DEBUG "l2tp_tunnel_inc_refcount: %s:%d %s: cnt=%d\n", __func__, __LINE__, (_t)->name, atomic_read(&_t->ref_count)); \
- l2tp_tunnel_inc_refcount_1(_t); \
- } while (0)
-#define l2tp_tunnel_dec_refcount(_t) do { \
- printk(KERN_DEBUG "l2tp_tunnel_dec_refcount: %s:%d %s: cnt=%d\n", __func__, __LINE__, (_t)->name, atomic_read(&_t->ref_count)); \
- l2tp_tunnel_dec_refcount_1(_t); \
- } while (0)
-#else
-#define l2tp_tunnel_inc_refcount(t) l2tp_tunnel_inc_refcount_1(t)
-#define l2tp_tunnel_dec_refcount(t) l2tp_tunnel_dec_refcount_1(t)
-#endif
-
/* Session hash global list for L2TPv3.
* The session_id SHOULD be random according to RFC3931, but several
* L2TP implementations use incrementing session_ids. So we do a real
}
EXPORT_SYMBOL_GPL(l2tp_session_find);
-struct l2tp_session *l2tp_session_find_nth(struct l2tp_tunnel *tunnel, int nth)
+/* Lookup a tunnel. A new reference is held on the returned tunnel. */
+struct l2tp_tunnel *l2tp_tunnel_get(const struct net *net, u32 tunnel_id)
+{
+ const struct l2tp_net *pn = l2tp_pernet(net);
+ struct l2tp_tunnel *tunnel;
+
+ rcu_read_lock_bh();
+ list_for_each_entry_rcu(tunnel, &pn->l2tp_tunnel_list, list) {
+ if (tunnel->tunnel_id == tunnel_id) {
+ l2tp_tunnel_inc_refcount(tunnel);
+ rcu_read_unlock_bh();
+
+ return tunnel;
+ }
+ }
+ rcu_read_unlock_bh();
+
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(l2tp_tunnel_get);
+
+/* Like l2tp_session_find() but takes a reference on the returned session.
+ * Optionally calls session->ref() too if do_ref is true.
+ */
+struct l2tp_session *l2tp_session_get(const struct net *net,
+ struct l2tp_tunnel *tunnel,
+ u32 session_id, bool do_ref)
+{
+ struct hlist_head *session_list;
+ struct l2tp_session *session;
+ struct hlist_node *walk;
+
+ if (!tunnel) {
+ struct l2tp_net *pn = l2tp_pernet(net);
+
+ session_list = l2tp_session_id_hash_2(pn, session_id);
+
+ rcu_read_lock_bh();
+ hlist_for_each_entry_rcu(session, walk, session_list, global_hlist) {
+ if (session->session_id == session_id) {
+ l2tp_session_inc_refcount(session);
+ if (do_ref && session->ref)
+ session->ref(session);
+ rcu_read_unlock_bh();
+
+ return session;
+ }
+ }
+ rcu_read_unlock_bh();
+
+ return NULL;
+ }
+
+ session_list = l2tp_session_id_hash(tunnel, session_id);
+ read_lock_bh(&tunnel->hlist_lock);
+ hlist_for_each_entry(session, walk, session_list, hlist) {
+ if (session->session_id == session_id) {
+ l2tp_session_inc_refcount(session);
+ if (do_ref && session->ref)
+ session->ref(session);
+ read_unlock_bh(&tunnel->hlist_lock);
+
+ return session;
+ }
+ }
+ read_unlock_bh(&tunnel->hlist_lock);
+
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(l2tp_session_get);
+
+struct l2tp_session *l2tp_session_get_nth(struct l2tp_tunnel *tunnel, int nth,
+ bool do_ref)
{
int hash;
struct hlist_node *walk;
for (hash = 0; hash < L2TP_HASH_SIZE; hash++) {
hlist_for_each_entry(session, walk, &tunnel->session_hlist[hash], hlist) {
if (++count > nth) {
+ l2tp_session_inc_refcount(session);
+ if (do_ref && session->ref)
+ session->ref(session);
read_unlock_bh(&tunnel->hlist_lock);
return session;
}
return NULL;
}
-EXPORT_SYMBOL_GPL(l2tp_session_find_nth);
+EXPORT_SYMBOL_GPL(l2tp_session_get_nth);
/* Lookup a session by interface name.
* This is very inefficient but is only used by management interfaces.
*/
-struct l2tp_session *l2tp_session_find_by_ifname(struct net *net, char *ifname)
+struct l2tp_session *l2tp_session_get_by_ifname(const struct net *net,
+ const char *ifname,
+ bool do_ref)
{
struct l2tp_net *pn = l2tp_pernet(net);
int hash;
for (hash = 0; hash < L2TP_HASH_SIZE_2; hash++) {
hlist_for_each_entry_rcu(session, walk, &pn->l2tp_session_hlist[hash], global_hlist) {
if (!strcmp(session->ifname, ifname)) {
+ l2tp_session_inc_refcount(session);
+ if (do_ref && session->ref)
+ session->ref(session);
rcu_read_unlock_bh();
+
return session;
}
}
return NULL;
}
-EXPORT_SYMBOL_GPL(l2tp_session_find_by_ifname);
+EXPORT_SYMBOL_GPL(l2tp_session_get_by_ifname);
+
+static int l2tp_session_add_to_tunnel(struct l2tp_tunnel *tunnel,
+ struct l2tp_session *session)
+{
+ struct l2tp_session *session_walk;
+ struct hlist_head *g_head;
+ struct hlist_head *head;
+ struct l2tp_net *pn;
+ struct hlist_node *walk;
+ int err;
+
+ head = l2tp_session_id_hash(tunnel, session->session_id);
+
+ write_lock_bh(&tunnel->hlist_lock);
+ if (!tunnel->acpt_newsess) {
+ err = -ENODEV;
+ goto err_tlock;
+ }
+
+ hlist_for_each_entry(session_walk, walk, head, hlist)
+ if (session_walk->session_id == session->session_id) {
+ err = -EEXIST;
+ goto err_tlock;
+ }
+
+ if (tunnel->version == L2TP_HDR_VER_3) {
+ pn = l2tp_pernet(tunnel->l2tp_net);
+ g_head = l2tp_session_id_hash_2(l2tp_pernet(tunnel->l2tp_net),
+ session->session_id);
+
+ spin_lock_bh(&pn->l2tp_session_hlist_lock);
+
+ hlist_for_each_entry(session_walk, walk, g_head, global_hlist)
+ if (session_walk->session_id == session->session_id) {
+ err = -EEXIST;
+ goto err_tlock_pnlock;
+ }
+
+ l2tp_tunnel_inc_refcount(tunnel);
+ sock_hold(tunnel->sock);
+ hlist_add_head_rcu(&session->global_hlist, g_head);
+
+ spin_unlock_bh(&pn->l2tp_session_hlist_lock);
+ } else {
+ l2tp_tunnel_inc_refcount(tunnel);
+ sock_hold(tunnel->sock);
+ }
+
+ hlist_add_head(&session->hlist, head);
+ write_unlock_bh(&tunnel->hlist_lock);
+
+ return 0;
+
+err_tlock_pnlock:
+ spin_unlock_bh(&pn->l2tp_session_hlist_lock);
+err_tlock:
+ write_unlock_bh(&tunnel->hlist_lock);
+
+ return err;
+}
/* Lookup a tunnel by id
*/
* a data (not control) frame before coming here. Fields up to the
* session-id have already been parsed and ptr points to the data
* after the session-id.
+ *
+ * session->ref() must have been called prior to l2tp_recv_common().
+ * session->deref() will be called automatically after skb is processed.
*/
void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb,
unsigned char *ptr, unsigned char *optr, u16 hdrflags,
int offset;
u32 ns, nr;
- /* The ref count is increased since we now hold a pointer to
- * the session. Take care to decrement the refcnt when exiting
- * this function from now on...
- */
- l2tp_session_inc_refcount(session);
- if (session->ref)
- (*session->ref)(session);
-
/* Parse and check optional cookie */
if (session->peer_cookie_len > 0) {
if (memcmp(ptr, &session->peer_cookie[0], session->peer_cookie_len)) {
/* Try to dequeue as many skbs from reorder_q as we can. */
l2tp_recv_dequeue(session);
- l2tp_session_dec_refcount(session);
-
return;
discard:
if (session->deref)
(*session->deref)(session);
-
- l2tp_session_dec_refcount(session);
}
EXPORT_SYMBOL(l2tp_recv_common);
}
/* Find the session context */
- session = l2tp_session_find(tunnel->l2tp_net, tunnel, session_id);
+ session = l2tp_session_get(tunnel->l2tp_net, tunnel, session_id, true);
if (!session || !session->recv_skb) {
+ if (session) {
+ if (session->deref)
+ session->deref(session);
+ l2tp_session_dec_refcount(session);
+ }
+
/* Not found? Pass to userspace to deal with */
PRINTK(tunnel->debug, L2TP_MSG_DATA, KERN_INFO,
"%s: no session found (%u/%u). Passing up.\n",
}
l2tp_recv_common(session, skb, ptr, optr, hdrflags, length, payload_hook);
+ l2tp_session_dec_refcount(session);
return 0;
"%s: closing all sessions...\n", tunnel->name);
write_lock_bh(&tunnel->hlist_lock);
+ tunnel->acpt_newsess = false;
for (hash = 0; hash < L2TP_HASH_SIZE; hash++) {
again:
hlist_for_each_safe(walk, tmp, &tunnel->session_hlist[hash]) {
/* Really kill the tunnel.
* Come here only when all sessions have been cleared from the tunnel.
*/
-static void l2tp_tunnel_free(struct l2tp_tunnel *tunnel)
+void l2tp_tunnel_free(struct l2tp_tunnel *tunnel)
{
struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net);
/* Remove from tunnel list */
spin_lock_bh(&pn->l2tp_tunnel_list_lock);
list_del_rcu(&tunnel->list);
+ kfree_rcu(tunnel, rcu);
spin_unlock_bh(&pn->l2tp_tunnel_list_lock);
- synchronize_rcu();
atomic_dec(&l2tp_tunnel_count);
- kfree(tunnel);
}
+EXPORT_SYMBOL_GPL(l2tp_tunnel_free);
/* Create a socket for the tunnel, if one isn't set up by
* userspace. This is used for static tunnels where there is no
tunnel->magic = L2TP_TUNNEL_MAGIC;
sprintf(&tunnel->name[0], "tunl %u", tunnel_id);
rwlock_init(&tunnel->hlist_lock);
+ tunnel->acpt_newsess = true;
/* The net we belong to */
tunnel->l2tp_net = net;
struct l2tp_session *l2tp_session_create(int priv_size, struct l2tp_tunnel *tunnel, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg)
{
struct l2tp_session *session;
+ int err;
session = kzalloc(sizeof(struct l2tp_session) + priv_size, GFP_KERNEL);
if (session != NULL) {
l2tp_session_set_header_len(session, tunnel->version);
- /* Bump the reference count. The session context is deleted
- * only when this drops to zero.
- */
l2tp_session_inc_refcount(session);
- l2tp_tunnel_inc_refcount(tunnel);
-
- /* Ensure tunnel socket isn't deleted */
- sock_hold(tunnel->sock);
-
- /* Add session to the tunnel's hash list */
- write_lock_bh(&tunnel->hlist_lock);
- hlist_add_head(&session->hlist,
- l2tp_session_id_hash(tunnel, session_id));
- write_unlock_bh(&tunnel->hlist_lock);
- /* And to the global session list if L2TPv3 */
- if (tunnel->version != L2TP_HDR_VER_2) {
- struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net);
+ err = l2tp_session_add_to_tunnel(tunnel, session);
+ if (err) {
+ kfree(session);
- spin_lock_bh(&pn->l2tp_session_hlist_lock);
- hlist_add_head_rcu(&session->global_hlist,
- l2tp_session_id_hash_2(pn, session_id));
- spin_unlock_bh(&pn->l2tp_session_hlist_lock);
+ return ERR_PTR(err);
}
/* Ignore management session in session count value */
if (session->session_id != 0)
atomic_inc(&l2tp_session_count);
+
+ return session;
}
- return session;
+ return ERR_PTR(-ENOMEM);
}
EXPORT_SYMBOL_GPL(l2tp_session_create);