Commit bc0e6467 authored by Stephen Hemminger's avatar Stephen Hemminger Committed by David S. Miller
Browse files

[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: default avatarStephen Hemminger <shemminger@osdl.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8f182b49

include/net/llc_if.h

+4 −0
Original line number Diff line number Diff line
@@ -79,6 +79,10 @@ static inline int llc_addrany(const struct llc_addr *addr) 
	return llc_mac_null(addr->mac) && !addr->lsap;

}



static inline int llc_mac_multicast(const u8 *mac)

{

	return is_multicast_ether_addr(mac);

}

/**

 *	llc_mac_match - determines if two mac addresses are the same

 *	@mac1: First mac address to compare.

net/llc/llc_sap.c

+51 −8
Original line number Diff line number Diff line
@@ -282,7 +282,7 @@ static void llc_sap_rcv(struct llc_sap *sap, struct sk_buff *skb) 
 *	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;
@@ -304,15 +304,57 @@ static struct sock *llc_lookup_dgram(struct llc_sap *sap, 
	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 (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);
@@ -320,3 +362,4 @@ void llc_sap_handler(struct llc_sap *sap, struct sk_buff *skb) 
		} else

			kfree_skb(skb);

	}

}