为什么关闭网卡的 RX offload 不起作用？

raw socket 读取到 Reassemble 不好处理，我把 offload 都关了：

Features for eth0: rx-checksumming: on [fixed] tx-checksumming: on tx-checksum-ipv4: off [fixed] tx-checksum-ip-generic: on tx-checksum-ipv6: off [fixed] tx-checksum-fcoe-crc: off [fixed] tx-checksum-sctp: off [fixed] scatter-gather: on tx-scatter-gather: on tx-scatter-gather-fraglist: off [fixed] tcp-segmentation-offload: off tx-tcp-segmentation: off tx-tcp-ecn-segmentation: off tx-tcp-mangleid-segmentation: off tx-tcp6-segmentation: off udp-fragmentation-offload: off generic-segmentation-offload: off generic-receive-offload: off large-receive-offload: off [fixed] rx-vlan-offload: off [fixed] tx-vlan-offload: off [fixed] ntuple-filters: off [fixed] receive-hashing: off [fixed] highdma: on [fixed] rx-vlan-filter: on [fixed] vlan-challenged: off [fixed] tx-lockless: off [fixed] netns-local: off [fixed] tx-gso-robust: on [fixed] tx-fcoe-segmentation: off [fixed] tx-gre-segmentation: off [fixed] tx-gre-csum-segmentation: off [fixed] tx-ipxip4-segmentation: off [fixed] tx-ipxip6-segmentation: off [fixed] tx-udp_tnl-segmentation: off [fixed] tx-udp_tnl-csum-segmentation: off [fixed] tx-gso-partial: off [fixed] tx-sctp-segmentation: off [fixed] tx-esp-segmentation: off [fixed] tx-udp-segmentation: off [fixed] fcoe-mtu: off [fixed] tx-nocache-copy: off loopback: off [fixed] rx-fcs: off [fixed] rx-all: off [fixed] tx-vlan-stag-hw-insert: off [fixed] rx-vlan-stag-hw-parse: off [fixed] rx-vlan-stag-filter: off [fixed] l2-fwd-offload: off [fixed] hw-tc-offload: off [fixed] esp-hw-offload: off [fixed] esp-tx-csum-hw-offload: off [fixed] rx-udp_tunnel-port-offload: off [fixed] tls-hw-tx-offload: off [fixed] tls-hw-rx-offload: off [fixed] rx-gro-hw: off [fixed] tls-hw-record: off [fixed] 

无论是 tcpdump ，还是 raw/eth socket 都会读取到大于 mtu 的 tcp 数据包, 一时整的我没辙了。

相关资料： https://v2ex.com/t/917581
https://github.com/wangyu-/udp2raw/issues/226
t/1053423