[][kernel][common][hnat][Fix the conditions for binding VLAN to HNAT]

Fix the conditions for binding VLAN to HNAT.
Whether egress packets carries vlan depends on skb ->vlan_present.

The previous code will fail when encountering the following situation:
PC1 send packets with vlan 45,
disable HNAT, PC2 capture packets without vlan.
enable HNAT, PC2 capture packets with vlan.

This patch fix it.


Change-Id: Iaa0916680733eda810b37abea2d0bd7201932cfd
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/6879837
1 file changed