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Diffstat (limited to 'net/llc/llc_sap.c')
-rw-r--r--net/llc/llc_sap.c111
1 files changed, 82 insertions, 29 deletions
diff --git a/net/llc/llc_sap.c b/net/llc/llc_sap.c
index 008de1fc42ca..ad6e6e1cf22f 100644
--- a/net/llc/llc_sap.c
+++ b/net/llc/llc_sap.c
@@ -297,6 +297,17 @@ static void llc_sap_rcv(struct llc_sap *sap, struct sk_buff *skb,
llc_sap_state_process(sap, skb);
}
+static inline bool llc_dgram_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_DGRAM &&
+ llc->laddr.lsap == laddr->lsap &&
+ llc_mac_match(llc->laddr.mac, laddr->mac);
+}
+
/**
* llc_lookup_dgram - Finds dgram socket for the local sap/mac
* @sap: SAP
@@ -309,25 +320,68 @@ static struct sock *llc_lookup_dgram(struct llc_sap *sap,
const struct llc_addr *laddr)
{
struct sock *rc;
- struct hlist_node *node;
-
- read_lock_bh(&sap->sk_list.lock);
- sk_for_each(rc, node, &sap->sk_list.list) {
- struct llc_sock *llc = llc_sk(rc);
-
- if (rc->sk_type == SOCK_DGRAM &&
- llc->laddr.lsap == laddr->lsap &&
- llc_mac_match(llc->laddr.mac, laddr->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_bh();
+again:
+ 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)))
+ goto again;
+ if (unlikely(llc_sk(rc)->sap != sap ||
+ !llc_dgram_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:
- read_unlock_bh(&sap->sk_list.lock);
+ rcu_read_unlock_bh();
return rc;
}
+static inline bool llc_mcast_match(const struct llc_sap *sap,
+ const struct llc_addr *laddr,
+ const struct sk_buff *skb,
+ const struct sock *sk)
+{
+ struct llc_sock *llc = llc_sk(sk);
+
+ return sk->sk_type == SOCK_DGRAM &&
+ llc->laddr.lsap == laddr->lsap &&
+ llc->dev == skb->dev;
+}
+
+static void llc_do_mcast(struct llc_sap *sap, struct sk_buff *skb,
+ struct sock **stack, int count)
+{
+ struct sk_buff *skb1;
+ int i;
+
+ for (i = 0; i < count; i++) {
+ skb1 = skb_clone(skb, GFP_ATOMIC);
+ if (!skb1) {
+ sock_put(stack[i]);
+ continue;
+ }
+
+ llc_sap_rcv(sap, skb1, stack[i]);
+ sock_put(stack[i]);
+ }
+}
+
/**
* llc_sap_mcast - Deliver multicast PDU's to all matching datagram sockets.
* @sap: SAP
@@ -340,32 +394,31 @@ static void llc_sap_mcast(struct llc_sap *sap,
const struct llc_addr *laddr,
struct sk_buff *skb)
{
- struct sock *sk;
+ int i = 0, count = 256 / sizeof(struct sock *);
+ struct sock *sk, *stack[count];
struct hlist_node *node;
+ struct llc_sock *llc;
+ struct hlist_head *dev_hb = llc_sk_dev_hash(sap, skb->dev->ifindex);
- read_lock_bh(&sap->sk_list.lock);
- sk_for_each(sk, node, &sap->sk_list.list) {
- struct llc_sock *llc = llc_sk(sk);
- struct sk_buff *skb1;
+ spin_lock_bh(&sap->sk_lock);
+ hlist_for_each_entry(llc, node, dev_hb, dev_hash_node) {
- if (sk->sk_type != SOCK_DGRAM)
- continue;
+ sk = &llc->sk;
- if (llc->laddr.lsap != laddr->lsap)
+ if (!llc_mcast_match(sap, laddr, skb, sk))
continue;
- if (llc->dev != skb->dev)
- continue;
-
- skb1 = skb_clone(skb, GFP_ATOMIC);
- if (!skb1)
- break;
-
sock_hold(sk);
- llc_sap_rcv(sap, skb1, sk);
- sock_put(sk);
+ if (i < count)
+ stack[i++] = sk;
+ else {
+ llc_do_mcast(sap, skb, stack, i);
+ i = 0;
+ }
}
- read_unlock_bh(&sap->sk_list.lock);
+ spin_unlock_bh(&sap->sk_lock);
+
+ llc_do_mcast(sap, skb, stack, i);
}