Commit 955062b0 authored by Nikolay Aleksandrov's avatar Nikolay Aleksandrov Committed by Jakub Kicinski
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net: bridge: mcast: add support for raw L2 multicast groups 



Extend the bridge multicast control and data path to configure routes
for L2 (non-IP) multicast groups.

The uapi struct br_mdb_entry union u is extended with another variant,
mac_addr, which does not change the structure size, and which is valid
when the proto field is zero.

To be compatible with the forwarding code that is already in place,
which acts as an IGMP/MLD snooping bridge with querier capabilities, we
need to declare that for L2 MDB entries (for which there exists no such
thing as IGMP/MLD snooping/querying), that there is always a querier.
Otherwise, these entries would be flooded to all bridge ports and not
just to those that are members of the L2 multicast group.

Needless to say, only permanent L2 multicast groups can be installed on
a bridge port.

Signed-off-by: default avatarNikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20201028233831.610076-1-vladimir.oltean@nxp.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 8ece853d

include/linux/if_bridge.h

+1 −0
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ struct br_ip { 
#if IS_ENABLED(CONFIG_IPV6)

		struct in6_addr ip6;

#endif

		unsigned char	mac_addr[ETH_ALEN];

	} dst;

	__be16		proto;

	__u16           vid;

include/uapi/linux/if_bridge.h

+1 −0
Original line number Diff line number Diff line
@@ -651,6 +651,7 @@ struct br_mdb_entry { 
		union {

			__be32	ip4;

			struct in6_addr ip6;

			unsigned char mac_addr[ETH_ALEN];

		} u;

		__be16		proto;

	} addr;

net/bridge/br_device.c

+1 −1
Original line number Diff line number Diff line
@@ -93,7 +93,7 @@ netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev) 


		mdst = br_mdb_get(br, skb, vid);

		if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) &&

		    br_multicast_querier_exists(br, eth_hdr(skb)))

		    br_multicast_querier_exists(br, eth_hdr(skb), mdst))

			br_multicast_flood(mdst, skb, false, true);

		else

			br_flood(br, skb, BR_PKT_MULTICAST, false, true);

net/bridge/br_input.c

+1 −1
Original line number Diff line number Diff line
@@ -134,7 +134,7 @@ int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb 
	case BR_PKT_MULTICAST:

		mdst = br_mdb_get(br, skb, vid);

		if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) &&

		    br_multicast_querier_exists(br, eth_hdr(skb))) {

		    br_multicast_querier_exists(br, eth_hdr(skb), mdst)) {

			if ((mdst && mdst->host_joined) ||

			    br_multicast_is_router(br)) {

				local_rcv = true;

net/bridge/br_mdb.c

+22 −2
Original line number Diff line number Diff line
@@ -87,6 +87,8 @@ static void __mdb_entry_to_br_ip(struct br_mdb_entry *entry, struct br_ip *ip, 
			ip->src.ip6 = nla_get_in6_addr(mdb_attrs[MDBE_ATTR_SOURCE]);

		break;

#endif

	default:

		ether_addr_copy(ip->dst.mac_addr, entry->addr.u.mac_addr);

	}



}
@@ -174,9 +176,11 @@ static int __mdb_fill_info(struct sk_buff *skb, 
	if (mp->addr.proto == htons(ETH_P_IP))

		e.addr.u.ip4 = mp->addr.dst.ip4;

#if IS_ENABLED(CONFIG_IPV6)

	if (mp->addr.proto == htons(ETH_P_IPV6))

	else if (mp->addr.proto == htons(ETH_P_IPV6))

		e.addr.u.ip6 = mp->addr.dst.ip6;

#endif

	else

		ether_addr_copy(e.addr.u.mac_addr, mp->addr.dst.mac_addr);

	e.addr.proto = mp->addr.proto;

	nest_ent = nla_nest_start_noflag(skb,

					 MDBA_MDB_ENTRY_INFO);
@@ -210,6 +214,8 @@ static int __mdb_fill_info(struct sk_buff *skb, 
		}

		break;

#endif

	default:

		ether_addr_copy(e.addr.u.mac_addr, mp->addr.dst.mac_addr);

	}

	if (p) {

		if (nla_put_u8(skb, MDBA_MDB_EATTR_RTPROT, p->rt_protocol))
@@ -562,9 +568,12 @@ void br_mdb_notify(struct net_device *dev, 
		if (mp->addr.proto == htons(ETH_P_IP))

			ip_eth_mc_map(mp->addr.dst.ip4, mdb.addr);

#if IS_ENABLED(CONFIG_IPV6)

		else

		else if (mp->addr.proto == htons(ETH_P_IPV6))

			ipv6_eth_mc_map(&mp->addr.dst.ip6, mdb.addr);

#endif

		else

			ether_addr_copy(mdb.addr, mp->addr.dst.mac_addr);



		mdb.obj.orig_dev = pg->key.port->dev;

		switch (type) {

		case RTM_NEWMDB:
@@ -693,6 +702,12 @@ static bool is_valid_mdb_entry(struct br_mdb_entry *entry, 
			return false;

		}

#endif

	} else if (entry->addr.proto == 0) {

		/* L2 mdb */

		if (!is_multicast_ether_addr(entry->addr.u.mac_addr)) {

			NL_SET_ERR_MSG_MOD(extack, "L2 entry group is not multicast");

			return false;

		}

	} else {

		NL_SET_ERR_MSG_MOD(extack, "Unknown entry protocol");

		return false;
@@ -849,6 +864,11 @@ static int br_mdb_add_group(struct net_bridge *br, struct net_bridge_port *port, 
		}

	}



	if (br_group_is_l2(&group) && entry->state != MDB_PERMANENT) {

		NL_SET_ERR_MSG_MOD(extack, "Only permanent L2 entries allowed");

		return -EINVAL;

	}



	mp = br_mdb_ip_get(br, &group);

	if (!mp) {

		mp = br_multicast_new_group(br, &group);

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