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-rw-r--r--net/llc/llc_conn.c70
-rw-r--r--net/llc/llc_core.c6
-rw-r--r--net/llc/llc_proc.c44
-rw-r--r--net/llc/llc_sap.c11
4 files changed, 95 insertions, 36 deletions
diff --git a/net/llc/llc_conn.c b/net/llc/llc_conn.c
index 10cdfe2db830..a8dde9b010da 100644
--- a/net/llc/llc_conn.c
+++ b/net/llc/llc_conn.c
@@ -498,10 +498,12 @@ static struct sock *__llc_lookup_established(struct llc_sap *sap,
{
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, &sap->sk_list) {
+ 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)))
@@ -515,6 +517,13 @@ again:
}
}
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;
@@ -540,29 +549,20 @@ static inline bool llc_listener_match(const struct llc_sap *sap,
return sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_LISTEN &&
llc->laddr.lsap == laddr->lsap &&
- (llc_mac_match(llc->laddr.mac, laddr->mac) ||
- llc_mac_null(llc->laddr.mac));
+ llc_mac_match(llc->laddr.mac, laddr->mac);
}
-/**
- * llc_lookup_listener - Finds listener for local MAC + SAP
- * @sap: SAP
- * @laddr: address of local LLC (MAC + SAP)
- *
- * Search connection list of the SAP and finds connection listening on
- * local mac, and local sap. Returns pointer for parent socket found,
- * %NULL otherwise.
- * Caller has to make sure local_bh is disabled.
- */
-static struct sock *llc_lookup_listener(struct llc_sap *sap,
- struct llc_addr *laddr)
+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, &sap->sk_list) {
+ 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)))
@@ -576,11 +576,40 @@ again:
}
}
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
+ * @laddr: address of local LLC (MAC + SAP)
+ *
+ * Search connection list of the SAP and finds connection listening on
+ * local mac, and local sap. Returns pointer for parent socket found,
+ * %NULL otherwise.
+ * Caller has to make sure local_bh is disabled.
+ */
+static struct sock *llc_lookup_listener(struct llc_sap *sap,
+ struct llc_addr *laddr)
+{
+ static struct llc_addr null_addr;
+ struct sock *rc = __llc_lookup_listener(sap, laddr);
+
+ if (!rc)
+ rc = __llc_lookup_listener(sap, &null_addr);
+
+ return rc;
+}
+
static struct sock *__llc_lookup(struct llc_sap *sap,
struct llc_addr *daddr,
struct llc_addr *laddr)
@@ -678,18 +707,20 @@ 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);
llc_sk(sk)->sap = sap;
spin_lock_bh(&sap->sk_lock);
- sk_nulls_add_node_rcu(sk, &sap->sk_list);
+ 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);
}
@@ -699,7 +730,7 @@ void llc_sap_add_socket(struct llc_sap *sap, struct sock *sk)
* @sap: SAP
* @sk: socket
*
- * This function removes a connection from sk_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)
@@ -709,6 +740,7 @@ void llc_sap_remove_socket(struct llc_sap *sap, struct sock *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);
}
diff --git a/net/llc/llc_core.c b/net/llc/llc_core.c
index 5276b9722077..0c9ef8bc7655 100644
--- a/net/llc/llc_core.c
+++ b/net/llc/llc_core.c
@@ -33,12 +33,14 @@ DEFINE_RWLOCK(llc_sap_list_lock);
static struct llc_sap *llc_sap_alloc(void)
{
struct llc_sap *sap = kzalloc(sizeof(*sap), GFP_ATOMIC);
+ int i;
if (sap) {
/* sap->laddr.mac - leave as a null, it's filled by bind */
sap->state = LLC_SAP_STATE_ACTIVE;
spin_lock_init(&sap->sk_lock);
- INIT_HLIST_NULLS_HEAD(&sap->sk_list, 0);
+ for (i = 0; i < LLC_SK_LADDR_HASH_ENTRIES; i++)
+ INIT_HLIST_NULLS_HEAD(&sap->sk_laddr_hash[i], i);
atomic_set(&sap->refcnt, 1);
}
return sap;
@@ -143,7 +145,7 @@ out:
*/
void llc_sap_close(struct llc_sap *sap)
{
- WARN_ON(!hlist_nulls_empty(&sap->sk_list));
+ WARN_ON(sap->sk_count);
llc_del_sap(sap);
kfree(sap);
}
diff --git a/net/llc/llc_proc.c b/net/llc/llc_proc.c
index 6b3d033b3236..09dec6307206 100644
--- a/net/llc/llc_proc.c
+++ b/net/llc/llc_proc.c
@@ -34,17 +34,22 @@ static struct sock *llc_get_sk_idx(loff_t pos)
{
struct list_head *sap_entry;
struct llc_sap *sap;
- struct hlist_nulls_node *node;
struct sock *sk = NULL;
+ int i;
list_for_each(sap_entry, &llc_sap_list) {
sap = list_entry(sap_entry, struct llc_sap, node);
spin_lock_bh(&sap->sk_lock);
- sk_nulls_for_each(sk, node, &sap->sk_list) {
- if (!pos)
- goto found;
- --pos;
+ for (i = 0; i < LLC_SK_LADDR_HASH_ENTRIES; i++) {
+ struct hlist_nulls_head *head = &sap->sk_laddr_hash[i];
+ struct hlist_nulls_node *node;
+
+ sk_nulls_for_each(sk, node, head) {
+ if (!pos)
+ goto found; /* keep the lock */
+ --pos;
+ }
}
spin_unlock_bh(&sap->sk_lock);
}
@@ -61,6 +66,19 @@ static void *llc_seq_start(struct seq_file *seq, loff_t *pos)
return l ? llc_get_sk_idx(--l) : SEQ_START_TOKEN;
}
+static struct sock *laddr_hash_next(struct llc_sap *sap, int bucket)
+{
+ struct hlist_nulls_node *node;
+ struct sock *sk = NULL;
+
+ while (++bucket < LLC_SK_LADDR_HASH_ENTRIES)
+ sk_nulls_for_each(sk, node, &sap->sk_laddr_hash[bucket])
+ goto out;
+
+out:
+ return sk;
+}
+
static void *llc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
struct sock* sk, *next;
@@ -80,17 +98,15 @@ static void *llc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
}
llc = llc_sk(sk);
sap = llc->sap;
+ sk = laddr_hash_next(sap, llc_sk_laddr_hashfn(sap, &llc->laddr));
+ if (sk)
+ goto out;
spin_unlock_bh(&sap->sk_lock);
- sk = NULL;
- for (;;) {
- if (sap->node.next == &llc_sap_list)
- break;
- sap = list_entry(sap->node.next, struct llc_sap, node);
+ list_for_each_entry_continue(sap, &llc_sap_list, node) {
spin_lock_bh(&sap->sk_lock);
- if (!hlist_nulls_empty(&sap->sk_list)) {
- sk = sk_nulls_head(&sap->sk_list);
- break;
- }
+ sk = laddr_hash_next(sap, -1);
+ if (sk)
+ break; /* keep the lock */
spin_unlock_bh(&sap->sk_lock);
}
out:
diff --git a/net/llc/llc_sap.c b/net/llc/llc_sap.c
index 94cb706f6cc4..ad6e6e1cf22f 100644
--- a/net/llc/llc_sap.c
+++ b/net/llc/llc_sap.c
@@ -321,10 +321,12 @@ static struct sock *llc_lookup_dgram(struct llc_sap *sap,
{
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_bh();
again:
- sk_nulls_for_each_rcu(rc, node, &sap->sk_list) {
+ sk_nulls_for_each_rcu(rc, node, laddr_hb) {
if (llc_dgram_match(sap, laddr, rc)) {
/* Extra checks required by SLAB_DESTROY_BY_RCU */
if (unlikely(!atomic_inc_not_zero(&rc->sk_refcnt)))
@@ -338,6 +340,13 @@ again:
}
}
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_bh();
return rc;
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.