[PATCH net-next 05/16] l2tp: use tunnel closing flag
From: James Chapman <jchapman@katalix.com>
Date: 2018-02-09 15:00:38
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
The tunnel's closing flag is set when the tunnel is being destroyed. Use it to reject new sessions and remove acpt_newsess which was doing the same thing. Also prevent the tunnel being seen in l2tp_tunnel_get lookups. Signed-off-by: James Chapman <jchapman@katalix.com> --- net/l2tp/l2tp_core.c | 27 +++++++++++++++++++++------ net/l2tp/l2tp_core.h | 4 ---- 2 files changed, 21 insertions(+), 10 deletions(-)
diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c
index 49d6e06099ec..691fe9368d91 100644
--- a/net/l2tp/l2tp_core.c
+++ b/net/l2tp/l2tp_core.c@@ -163,6 +163,13 @@ struct l2tp_tunnel *l2tp_tunnel_get(const struct net *net, u32 tunnel_id) rcu_read_lock_bh(); list_for_each_entry_rcu(tunnel, &pn->l2tp_tunnel_list, list) { if (tunnel->tunnel_id == tunnel_id) { + spin_lock_bh(&tunnel->lock); + if (tunnel->closing) { + spin_unlock_bh(&tunnel->lock); + rcu_read_unlock_bh(); + return NULL; + } + spin_unlock_bh(&tunnel->lock); l2tp_tunnel_inc_refcount(tunnel); rcu_read_unlock_bh();
@@ -278,13 +285,16 @@ int l2tp_session_register(struct l2tp_session *session, struct l2tp_net *pn; int err; + spin_lock_bh(&tunnel->lock); + if (tunnel->closing) { + spin_unlock_bh(&tunnel->lock); + return -ENODEV; + } + spin_unlock_bh(&tunnel->lock); + 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) {
@@ -1220,7 +1230,6 @@ 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]) {
@@ -1506,7 +1515,6 @@ int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, u32 sprintf(&tunnel->name[0], "tunl %u", tunnel_id); spin_lock_init(&tunnel->lock); rwlock_init(&tunnel->hlist_lock); - tunnel->acpt_newsess = true; /* The net we belong to */ tunnel->l2tp_net = net;
@@ -1710,6 +1718,13 @@ struct l2tp_session *l2tp_session_create(int priv_size, struct l2tp_tunnel *tunn { struct l2tp_session *session; + spin_lock_bh(&tunnel->lock); + if (tunnel->closing) { + spin_unlock_bh(&tunnel->lock); + return ERR_PTR(-ENODEV); + } + spin_unlock_bh(&tunnel->lock); + session = kzalloc(sizeof(struct l2tp_session) + priv_size, GFP_KERNEL); if (session != NULL) { session->magic = L2TP_SESSION_MAGIC;
diff --git a/net/l2tp/l2tp_core.h b/net/l2tp/l2tp_core.h
index e88ff7895ccb..4e098c822cd1 100644
--- a/net/l2tp/l2tp_core.h
+++ b/net/l2tp/l2tp_core.h@@ -160,10 +160,6 @@ struct l2tp_tunnel { struct rcu_head rcu; rwlock_t hlist_lock; /* protect session_hlist */ - bool acpt_newsess; /* Indicates whether this - * tunnel accepts new sessions. - * Protected by hlist_lock. - */ struct hlist_head session_hlist[L2TP_HASH_SIZE]; /* hashed list of sessions, * hashed by id */
--
1.9.1