diff options
Diffstat (limited to 'net/l2tp/l2tp_core.c')
-rw-r--r-- | net/l2tp/l2tp_core.c | 113 |
1 files changed, 51 insertions, 62 deletions
diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c index b0c2d4ae781d..ee485df73ccd 100644 --- a/net/l2tp/l2tp_core.c +++ b/net/l2tp/l2tp_core.c @@ -113,7 +113,6 @@ struct l2tp_net { spinlock_t l2tp_session_hlist_lock; }; -static void l2tp_tunnel_free(struct l2tp_tunnel *tunnel); static inline struct l2tp_tunnel *l2tp_tunnel(struct sock *sk) { @@ -127,39 +126,6 @@ static inline struct l2tp_net *l2tp_pernet(const struct net *net) return net_generic(net, l2tp_net_id); } -/* Tunnel reference counts. Incremented per session that is added to - * the tunnel. - */ -static inline void l2tp_tunnel_inc_refcount_1(struct l2tp_tunnel *tunnel) -{ - refcount_inc(&tunnel->ref_count); -} - -static inline void l2tp_tunnel_dec_refcount_1(struct l2tp_tunnel *tunnel) -{ - if (refcount_dec_and_test(&tunnel->ref_count)) - l2tp_tunnel_free(tunnel); -} -#ifdef L2TP_REFCNT_DEBUG -#define l2tp_tunnel_inc_refcount(_t) \ -do { \ - pr_debug("l2tp_tunnel_inc_refcount: %s:%d %s: cnt=%d\n", \ - __func__, __LINE__, (_t)->name, \ - refcount_read(&_t->ref_count)); \ - l2tp_tunnel_inc_refcount_1(_t); \ -} while (0) -#define l2tp_tunnel_dec_refcount(_t) \ -do { \ - pr_debug("l2tp_tunnel_dec_refcount: %s:%d %s: cnt=%d\n", \ - __func__, __LINE__, (_t)->name, \ - refcount_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 @@ -229,6 +195,27 @@ l2tp_session_id_hash(struct l2tp_tunnel *tunnel, u32 session_id) return &tunnel->session_hlist[hash_32(session_id, L2TP_HASH_BITS)]; } +/* 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); + /* Lookup a session. A new reference is held on the returned session. * Optionally calls session->ref() too if do_ref is true. */ @@ -342,13 +329,21 @@ static int l2tp_session_add_to_tunnel(struct l2tp_tunnel *tunnel, struct hlist_head *g_head; struct hlist_head *head; struct l2tp_net *pn; + 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, head, hlist) - if (session_walk->session_id == session->session_id) - goto exist; + 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); @@ -356,12 +351,21 @@ static int l2tp_session_add_to_tunnel(struct l2tp_tunnel *tunnel, session->session_id); spin_lock_bh(&pn->l2tp_session_hlist_lock); + hlist_for_each_entry(session_walk, g_head, global_hlist) - if (session_walk->session_id == session->session_id) - goto exist_glob; + 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); @@ -369,12 +373,12 @@ static int l2tp_session_add_to_tunnel(struct l2tp_tunnel *tunnel, return 0; -exist_glob: +err_tlock_pnlock: spin_unlock_bh(&pn->l2tp_session_hlist_lock); -exist: +err_tlock: write_unlock_bh(&tunnel->hlist_lock); - return -EEXIST; + return err; } /* Lookup a tunnel by id @@ -1264,7 +1268,6 @@ static void l2tp_tunnel_destruct(struct sock *sk) /* Remove hooks into tunnel socket */ sk->sk_destruct = tunnel->old_sk_destruct; sk->sk_user_data = NULL; - tunnel->sock = NULL; /* Remove the tunnel struct from the tunnel list */ pn = l2tp_pernet(tunnel->l2tp_net); @@ -1274,6 +1277,8 @@ static void l2tp_tunnel_destruct(struct sock *sk) atomic_dec(&l2tp_tunnel_count); l2tp_tunnel_closeall(tunnel); + + tunnel->sock = NULL; l2tp_tunnel_dec_refcount(tunnel); /* Call the original destructor */ @@ -1298,6 +1303,7 @@ void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel) 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]) { @@ -1348,17 +1354,6 @@ static void l2tp_udp_encap_destroy(struct sock *sk) } } -/* 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) -{ - BUG_ON(refcount_read(&tunnel->ref_count) != 0); - BUG_ON(tunnel->sock != NULL); - l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: free...\n", tunnel->name); - kfree_rcu(tunnel, rcu); -} - /* Workqueue tunnel deletion function */ static void l2tp_tunnel_del_work(struct work_struct *work) { @@ -1605,6 +1600,7 @@ int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, u32 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; @@ -1844,6 +1840,8 @@ struct l2tp_session *l2tp_session_create(int priv_size, struct l2tp_tunnel *tunn l2tp_session_set_header_len(session, tunnel->version); + refcount_set(&session->ref_count, 1); + err = l2tp_session_add_to_tunnel(tunnel, session); if (err) { kfree(session); @@ -1851,15 +1849,6 @@ struct l2tp_session *l2tp_session_create(int priv_size, struct l2tp_tunnel *tunn return ERR_PTR(err); } - /* Bump the reference count. The session context is deleted - * only when this drops to zero. - */ - refcount_set(&session->ref_count, 1); - l2tp_tunnel_inc_refcount(tunnel); - - /* Ensure tunnel socket isn't deleted */ - sock_hold(tunnel->sock); - /* Ignore management session in session count value */ if (session->session_id != 0) atomic_inc(&l2tp_session_count); |