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Diffstat (limited to 'net/llc/llc_conn.c')
-rw-r--r--net/llc/llc_conn.c146
1 files changed, 109 insertions, 37 deletions
diff --git a/net/llc/llc_conn.c b/net/llc/llc_conn.c
index c6bab39b018..a12144da797 100644
--- a/net/llc/llc_conn.c
+++ b/net/llc/llc_conn.c
@@ -468,6 +468,19 @@ static int llc_exec_conn_trans_actions(struct sock *sk,
return rc;
}
+static inline bool llc_estab_match(const struct llc_sap *sap,
+ const struct llc_addr *daddr,
+ const struct llc_addr *laddr,
+ const struct sock *sk)
+{
+ struct llc_sock *llc = llc_sk(sk);
+
+ return llc->laddr.lsap == laddr->lsap &&
+ llc->daddr.lsap == daddr->lsap &&
+ llc_mac_match(llc->laddr.mac, laddr->mac) &&
+ llc_mac_match(llc->daddr.mac, daddr->mac);
+}
+
/**
* __llc_lookup_established - Finds connection for the remote/local sap/mac
* @sap: SAP
@@ -484,23 +497,35 @@ static struct sock *__llc_lookup_established(struct llc_sap *sap,
struct llc_addr *laddr)
{
struct sock *rc;
- struct hlist_node *node;
-
- read_lock(&sap->sk_list.lock);
- sk_for_each(rc, node, &sap->sk_list.list) {
- struct llc_sock *llc = llc_sk(rc);
-
- if (llc->laddr.lsap == laddr->lsap &&
- llc->daddr.lsap == daddr->lsap &&
- llc_mac_match(llc->laddr.mac, laddr->mac) &&
- llc_mac_match(llc->daddr.mac, daddr->mac)) {
- sock_hold(rc);
+ struct hlist_nulls_node *node;
+ int slot = llc_sk_laddr_hashfn(sap, laddr);
+ struct hlist_nulls_head *laddr_hb = &sap->sk_laddr_hash[slot];
+
+ rcu_read_lock();
+again:
+ sk_nulls_for_each_rcu(rc, node, laddr_hb) {
+ if (llc_estab_match(sap, daddr, laddr, rc)) {
+ /* Extra checks required by SLAB_DESTROY_BY_RCU */
+ if (unlikely(!atomic_inc_not_zero(&rc->sk_refcnt)))
+ goto again;
+ if (unlikely(llc_sk(rc)->sap != sap ||
+ !llc_estab_match(sap, daddr, laddr, rc))) {
+ sock_put(rc);
+ continue;
+ }
goto found;
}
}
rc = NULL;
+ /*
+ * if the nulls value we got at the end of this lookup is
+ * not the expected one, we must restart lookup.
+ * We probably met an item that was moved to another chain.
+ */
+ if (unlikely(get_nulls_value(node) != slot))
+ goto again;
found:
- read_unlock(&sap->sk_list.lock);
+ rcu_read_unlock();
return rc;
}
@@ -516,6 +541,53 @@ struct sock *llc_lookup_established(struct llc_sap *sap,
return sk;
}
+static inline bool llc_listener_match(const struct llc_sap *sap,
+ const struct llc_addr *laddr,
+ const struct sock *sk)
+{
+ struct llc_sock *llc = llc_sk(sk);
+
+ return sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_LISTEN &&
+ llc->laddr.lsap == laddr->lsap &&
+ llc_mac_match(llc->laddr.mac, laddr->mac);
+}
+
+static struct sock *__llc_lookup_listener(struct llc_sap *sap,
+ struct llc_addr *laddr)
+{
+ struct sock *rc;
+ struct hlist_nulls_node *node;
+ int slot = llc_sk_laddr_hashfn(sap, laddr);
+ struct hlist_nulls_head *laddr_hb = &sap->sk_laddr_hash[slot];
+
+ rcu_read_lock();
+again:
+ sk_nulls_for_each_rcu(rc, node, laddr_hb) {
+ if (llc_listener_match(sap, laddr, rc)) {
+ /* Extra checks required by SLAB_DESTROY_BY_RCU */
+ if (unlikely(!atomic_inc_not_zero(&rc->sk_refcnt)))
+ goto again;
+ if (unlikely(llc_sk(rc)->sap != sap ||
+ !llc_listener_match(sap, laddr, rc))) {
+ sock_put(rc);
+ continue;
+ }
+ goto found;
+ }
+ }
+ rc = NULL;
+ /*
+ * if the nulls value we got at the end of this lookup is
+ * not the expected one, we must restart lookup.
+ * We probably met an item that was moved to another chain.
+ */
+ if (unlikely(get_nulls_value(node) != slot))
+ goto again;
+found:
+ rcu_read_unlock();
+ return rc;
+}
+
/**
* llc_lookup_listener - Finds listener for local MAC + SAP
* @sap: SAP
@@ -529,24 +601,12 @@ struct sock *llc_lookup_established(struct llc_sap *sap,
static struct sock *llc_lookup_listener(struct llc_sap *sap,
struct llc_addr *laddr)
{
- struct sock *rc;
- struct hlist_node *node;
+ static struct llc_addr null_addr;
+ struct sock *rc = __llc_lookup_listener(sap, laddr);
- read_lock(&sap->sk_list.lock);
- sk_for_each(rc, node, &sap->sk_list.list) {
- struct llc_sock *llc = llc_sk(rc);
+ if (!rc)
+ rc = __llc_lookup_listener(sap, &null_addr);
- if (rc->sk_type == SOCK_STREAM && rc->sk_state == TCP_LISTEN &&
- llc->laddr.lsap == laddr->lsap &&
- (llc_mac_match(llc->laddr.mac, laddr->mac) ||
- llc_mac_null(llc->laddr.mac))) {
- sock_hold(rc);
- goto found;
- }
- }
- rc = NULL;
-found:
- read_unlock(&sap->sk_list.lock);
return rc;
}
@@ -647,15 +707,22 @@ static int llc_find_offset(int state, int ev_type)
* @sap: SAP
* @sk: socket
*
- * This function adds a socket to sk_list of a SAP.
+ * This function adds a socket to the hash tables of a SAP.
*/
void llc_sap_add_socket(struct llc_sap *sap, struct sock *sk)
{
+ struct llc_sock *llc = llc_sk(sk);
+ struct hlist_head *dev_hb = llc_sk_dev_hash(sap, llc->dev->ifindex);
+ struct hlist_nulls_head *laddr_hb = llc_sk_laddr_hash(sap, &llc->laddr);
+
llc_sap_hold(sap);
- write_lock_bh(&sap->sk_list.lock);
llc_sk(sk)->sap = sap;
- sk_add_node(sk, &sap->sk_list.list);
- write_unlock_bh(&sap->sk_list.lock);
+
+ spin_lock_bh(&sap->sk_lock);
+ sap->sk_count++;
+ sk_nulls_add_node_rcu(sk, laddr_hb);
+ hlist_add_head(&llc->dev_hash_node, dev_hb);
+ spin_unlock_bh(&sap->sk_lock);
}
/**
@@ -663,14 +730,18 @@ void llc_sap_add_socket(struct llc_sap *sap, struct sock *sk)
* @sap: SAP
* @sk: socket
*
- * This function removes a connection from sk_list.list of a SAP if
+ * This function removes a connection from the hash tables of a SAP if
* the connection was in this list.
*/
void llc_sap_remove_socket(struct llc_sap *sap, struct sock *sk)
{
- write_lock_bh(&sap->sk_list.lock);
- sk_del_node_init(sk);
- write_unlock_bh(&sap->sk_list.lock);
+ struct llc_sock *llc = llc_sk(sk);
+
+ spin_lock_bh(&sap->sk_lock);
+ sk_nulls_del_node_init_rcu(sk);
+ hlist_del(&llc->dev_hash_node);
+ sap->sk_count--;
+ spin_unlock_bh(&sap->sk_lock);
llc_sap_put(sap);
}
@@ -756,7 +827,8 @@ void llc_conn_handler(struct llc_sap *sap, struct sk_buff *skb)
else {
dprintk("%s: adding to backlog...\n", __func__);
llc_set_backlog_type(skb, LLC_PACKET);
- sk_add_backlog(sk, skb);
+ if (sk_add_backlog(sk, skb))
+ goto drop_unlock;
}
out:
bh_unlock_sock(sk);
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-17 09:08:45 +0000