On 2025/01/17 20:17, Laurent Vivier wrote:
When a packet is sent with QEMU_NET_PACKET_FLAG_RAW by QEMU it never includes virtio-net header even if qemu_get_vnet_hdr_len() is not 0, and filter-dump is not managing this case.The only user of QEMU_NET_PACKET_FLAG_RAW is announce_self, we can show the problem using it and tcpddump: - QEMU parameters: .. -monitor stdio \ -netdev bridge,id=netdev0,br=virbr0 \ -device virtio-net,mac=9a:2b:2c:2d:2e:2f,netdev=netdev0 \ -object filter-dump,netdev=netdev0,file=log.pcap,id=pcap0 - HMP command: (qemu) announce_self - TCP dump: $ tcpdump -nxr log.pcap without the fix: 08:00:06:04:00:03 > 2e:2f:80:35:00:01, ethertype Unknown (0x9a2b), length 50: 0x0000: 2c2d 2e2f 0000 0000 9a2b 2c2d 2e2f 0000 0x0010: 0000 0000 0000 0000 0000 0000 0000 0000 0x0020: 0000 0000 with the fix: ARP, Reverse Request who-is 9a:2b:2c:2d:2e:2f tell 9a:2b:2c:2d:2e:2f, length 46 0x0000: 0001 0800 0604 0003 9a2b 2c2d 2e2f 0000 0x0010: 0000 9a2b 2c2d 2e2f 0000 0000 0000 0000 0x0020: 0000 0000 0000 0000 0000 0000 0000 Fixes: 481c52320a26 ("net: Strip virtio-net header when dumping") Cc: [email protected] Signed-off-by: Laurent Vivier <[email protected]>
Reviewed-by: Akihiko Odaki <[email protected]>
