diff options
| author | Shengyu Qu <wiagn233@outlook.com> | 2025-04-14 18:56:01 +0800 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-04-15 17:25:52 -0700 |
| commit | a496d2f0fd612ab9e10700afe00dc9267bad788b (patch) | |
| tree | 9c39cbdf7870593820eec5ae1cc0b30e4ecb9a5b | |
| parent | 1310f44dd4d635f278fb01330fddf416106332ff (diff) | |
net: bridge: locally receive all multicast packets if IFF_ALLMULTI is set
If multicast snooping is enabled, multicast packets may not always end up
on the local bridge interface, if the host is not a member of the multicast
group. Similar to how IFF_PROMISC allows all packets to be received
locally, let IFF_ALLMULTI allow all multicast packets to be received.
OpenWrt uses a user space daemon for DHCPv6/RA/NDP handling, and in relay
mode it sets the ALLMULTI flag in order to receive all relevant queries on
the network.
This works for normal network interfaces and non-snooping bridges, but not
snooping bridges (unless multicast routing is enabled).
Reported-by: Felix Fietkau <nbd@nbd.name>
Closes: https://github.com/openwrt/openwrt/issues/15857#issuecomment-2662851243
Signed-off-by: Shengyu Qu <wiagn233@outlook.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/OSZPR01MB8434308370ACAFA90A22980798B32@OSZPR01MB8434.jpnprd01.prod.outlook.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | net/bridge/br_input.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c index 232133a0fd21..5f6ac9bf1527 100644 --- a/net/bridge/br_input.c +++ b/net/bridge/br_input.c @@ -189,7 +189,8 @@ int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) && br_multicast_querier_exists(brmctx, eth_hdr(skb), mdst)) { if ((mdst && mdst->host_joined) || - br_multicast_is_router(brmctx, skb)) { + br_multicast_is_router(brmctx, skb) || + br->dev->flags & IFF_ALLMULTI) { local_rcv = true; DEV_STATS_INC(br->dev, multicast); } |