Ebtables on the OUTPUT chain (NF_BR_LOCAL_OUT) would not work as expected for both locally generated IGMP and MLD queries. The IP header specific filter options are off by 14 Bytes for netfilter (actual output on interfaces is fine). NF_HOOK() expects the skb->data to point to the IP header, not the ethernet one (while dev_queue_xmit() does not). Luckily there is an br_dev_queue_push_xmit() helper function already - let's just use that. Introduced by eb1d16414339a6e113d89e2cca2556005d7ce919 ("bridge: Add core IGMP snooping support") Ebtables example: $ ebtables -I OUTPUT -p IPv6 -o eth1 --logical-out br0 \ --log --log-level 6 --log-ip6 --log-prefix="~EBT: " -j DROP before (broken): ~EBT: IN= OUT=eth1 MAC source = 02:04:64:a4:39:c2 \ MAC dest = 33:33:00:00:00:01 proto = 0x86dd IPv6 \ SRC=64a4:39c2:86dd:6000:0000:0020:0001:fe80 IPv6 \ DST=0000:0000:0000:0004:64ff:fea4:39c2:ff02, \ IPv6 priority=0x3, Next Header=2 after (working): ~EBT: IN= OUT=eth1 MAC source = 02:04:64:a4:39:c2 \ MAC dest = 33:33:00:00:00:01 proto = 0x86dd IPv6 \ SRC=fe80:0000:0000:0000:0004:64ff:fea4:39c2 IPv6 \ DST=ff02:0000:0000:0000:0000:0000:0000:0001, \ IPv6 priority=0x0, Next Header=0
Unified · Split
| @@ -813,10 +813,9 @@ static void __br_multicast_send_query(struct net_bridge *br, · 812 unmodified lines | ||
| 813 | 813 | return; |
| 814 | 814 | |
| 815 | 815 | if (port) { |
| 816 | − __skb_push(skb, sizeof(struct ethhdr)); | |
| 817 | 816 | skb->dev = port->dev; |
| 818 | 817 | NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev, |
| 819 | − dev_queue_xmit); | |
| 818 | + br_dev_queue_push_xmit); | |
| 820 | 819 | } else { |
| 821 | 820 | br_multicast_select_own_querier(br, ip, skb); |
| 822 | 821 | netif_rx(skb); |