1 files changed, 110 insertions, 37 deletions

diff --git a/net/llc/llc_conn.c b/net/llc/llc_conn.c
index c6bab39b018e..ba137a6a224d 100644
--- a/net/llc/llc_conn.c
+++ b/net/llc/llc_conn.c
@@ -13,6 +13,7 @@
  */
 
 #include <linux/init.h>
+#include <linux/slab.h>
 #include <net/llc_sap.h>
 #include <net/llc_conn.h>
 #include <net/sock.h>
@@ -468,6 +469,19 @@ 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 +498,35 @@ 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 +542,53 @@ 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 +602,12 @@ 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 +708,22 @@ 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 +731,18 @@ 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 +828,8 @@ 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);