[LLC]: add multicast support for datagrams
Allow mulitcast reception of datagrams (similar to UDP).
All sockets bound to the same SAP receive a clone.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/llc/llc_sap.c b/net/llc/llc_sap.c
index 4029cee..20c4eb5 100644
--- a/net/llc/llc_sap.c
+++ b/net/llc/llc_sap.c
@@ -282,7 +282,7 @@
* mac, and local sap. Returns pointer for socket found, %NULL otherwise.
*/
static struct sock *llc_lookup_dgram(struct llc_sap *sap,
- struct llc_addr *laddr)
+ const struct llc_addr *laddr)
{
struct sock *rc;
struct hlist_node *node;
@@ -304,19 +304,62 @@
return rc;
}
+/**
+ * llc_sap_mcast - Deliver multicast PDU's to all matching datagram sockets.
+ * @sap: SAP
+ * @laddr: address of local LLC (MAC + SAP)
+ *
+ * Search socket list of the SAP and finds connections with same sap.
+ * Deliver clone to each.
+ */
+static void llc_sap_mcast(struct llc_sap *sap,
+ const struct llc_addr *laddr,
+ struct sk_buff *skb)
+{
+ struct sock *sk;
+ struct hlist_node *node;
+
+ 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;
+
+ if (sk->sk_type != SOCK_DGRAM)
+ continue;
+
+ if (llc->laddr.lsap != laddr->lsap)
+ continue;
+
+ skb1 = skb_clone(skb, GFP_ATOMIC);
+ if (!skb1)
+ break;
+
+ sock_hold(sk);
+ skb_set_owner_r(skb1, sk);
+ llc_sap_rcv(sap, skb1);
+ sock_put(sk);
+ }
+ read_unlock_bh(&sap->sk_list.lock);
+}
+
+
void llc_sap_handler(struct llc_sap *sap, struct sk_buff *skb)
{
struct llc_addr laddr;
- struct sock *sk;
llc_pdu_decode_da(skb, laddr.mac);
llc_pdu_decode_dsap(skb, &laddr.lsap);
- sk = llc_lookup_dgram(sap, &laddr);
- if (sk) {
- skb_set_owner_r(skb, sk);
- llc_sap_rcv(sap, skb);
- sock_put(sk);
- } else
+ if (llc_mac_multicast(laddr.mac)) {
+ llc_sap_mcast(sap, &laddr, skb);
kfree_skb(skb);
+ } else {
+ struct sock *sk = llc_lookup_dgram(sap, &laddr);
+ if (sk) {
+ skb_set_owner_r(skb, sk);
+ llc_sap_rcv(sap, skb);
+ sock_put(sk);
+ } else
+ kfree_skb(skb);
+ }
}