tc: m_vlan: Add vlan modify action

The 'vlan modify' action allows to replace an existing 802.1q tag
according to user provided settings.
It accepts same arguments as the 'vlan push' action.

For example, this replaces vid 6 with vid 5:

 # tc filter add dev veth0 parent ffff: pref 1 protocol 802.1q \
      basic match 'meta(vlan mask 0xfff eq 6)' \
      action vlan modify id 5 continue

Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
2 files changed