diff options
Diffstat (limited to 'net/llc/llc_conn.c')
-rw-r--r-- | net/llc/llc_conn.c | 146 |
1 files changed, 109 insertions, 37 deletions
diff --git a/net/llc/llc_conn.c b/net/llc/llc_conn.c index c6bab39..a12144d 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); |