On 11/04/2022 16:38, Joachim Wiberg wrote:
> Unknown multicast, MAC/IPv4/IPv6, should always be flooded according to
> the per-port mcast_flood setting, as well as to detected and configured
> mcast_router ports.
>
> This patch drops the mrouters_only classifier of unknown IP multicast
> and moves the flow handling from br_multicast_flood() to br_flood().
> This in turn means br_flood() must know about multicast router ports.
>
> Signed-off-by: Joachim Wiberg <troglobit@xxxxxxxxx>
> ---
> net/bridge/br_forward.c | 11 +++++++++++
> net/bridge/br_multicast.c | 6 +-----
> 2 files changed, 12 insertions(+), 5 deletions(-)
>
If you'd like to flood unknown mcast traffic when a router is present please add
a new option which defaults to the current state (disabled).
> diff --git a/net/bridge/br_forward.c b/net/bridge/br_forward.c
> index 02bb620d3b8d..ab5b97a8c12e 100644
> --- a/net/bridge/br_forward.c
> +++ b/net/bridge/br_forward.c
> @@ -199,9 +199,15 @@ static struct net_bridge_port *maybe_deliver(
> void br_flood(struct net_bridge *br, struct sk_buff *skb,
> enum br_pkt_type pkt_type, bool local_rcv, bool local_orig)
> {
> + struct net_bridge_mcast *brmctx = &br->multicast_ctx;
Note this breaks per-vlan mcast. You have to use the inferred mctx.
> + struct net_bridge_port *rport = NULL;
> struct net_bridge_port *prev = NULL;
> + struct hlist_node *rp = NULL;
> struct net_bridge_port *p;
>
> + if (pkt_type == BR_PKT_MULTICAST)
> + rp = br_multicast_get_first_rport_node(brmctx, skb);
> +
> list_for_each_entry_rcu(p, &br->port_list, list) {
> /* Do not flood unicast traffic to ports that turn it off, nor
> * other traffic if flood off, except for traffic we originate
> @@ -212,6 +218,11 @@ void br_flood(struct net_bridge *br, struct sk_buff *skb,
> continue;
> break;
> case BR_PKT_MULTICAST:
> + rport = br_multicast_rport_from_node_skb(rp, skb);
> + if (rport == p) {
> + rp = rcu_dereference(hlist_next_rcu(rp));
> + break;
> + }
> if (!(p->flags & BR_MCAST_FLOOD) && skb->dev != br->dev)
> continue;
> break;
> diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
> index db4f2641d1cd..c57e3bbb00ad 100644
> --- a/net/bridge/br_multicast.c
> +++ b/net/bridge/br_multicast.c
> @@ -3643,9 +3643,7 @@ static int br_multicast_ipv4_rcv(struct net_bridge_mcast *brmctx,
> err = ip_mc_check_igmp(skb);
>
> if (err == -ENOMSG) {
> - if (!ipv4_is_local_multicast(ip_hdr(skb)->daddr)) {
> - BR_INPUT_SKB_CB(skb)->mrouters_only = 1;
> - } else if (pim_ipv4_all_pim_routers(ip_hdr(skb)->daddr)) {
> + if (pim_ipv4_all_pim_routers(ip_hdr(skb)->daddr)) {
> if (ip_hdr(skb)->protocol == IPPROTO_PIM)
> br_multicast_pim(brmctx, pmctx, skb);
> } else if (ipv4_is_all_snoopers(ip_hdr(skb)->daddr)) {
> @@ -3712,8 +3710,6 @@ static int br_multicast_ipv6_rcv(struct net_bridge_mcast *brmctx,
> err = ipv6_mc_check_mld(skb);
>
> if (err == -ENOMSG || err == -ENODATA) {
> - if (!ipv6_addr_is_ll_all_nodes(&ipv6_hdr(skb)->daddr))
> - BR_INPUT_SKB_CB(skb)->mrouters_only = 1;
> if (err == -ENODATA &&
> ipv6_addr_is_all_snoopers(&ipv6_hdr(skb)->daddr))
> br_ip6_multicast_mrd_rcv(brmctx, pmctx, skb);
