flower(8) flow based traffic control filter


tc filter ... flower [ MATCH_LIST ] [ action ACTION_SPEC ] [ classid CLASSID ]


MATCH := { indev ifname | { dst_mac | src_mac } mac_address | eth_type { ipv4 | ipv6 | ETH_TYPE } | ip_proto { tcp | udp | IP_PROTO } | { dst_ip | src_ip } { ipv4_address | ipv6_address } | { dst_port | src_port } port_number }


The flower filter matches flows to the set of keys specified and assigns an arbitrarily chosen class ID to packets belonging to them. Additionally (or alternatively) an action from the generic action framework may be called.


Apply an action from the generic actions framework on matching packets.
classid CLASSID
Specify a class to pass matching packets on to. CLASSID is in the form X:Y, while X and Y are interpreted as numbers in hexadecimal format.
indev ifname
Match on incoming interface name. Obviously this makes sense only for forwarded flows. ifname is the name of an interface which must exist at the time of tc invocation.
dst_mac mac_address
src_mac mac_address Match on source or destination MAC address.
eth_type ETH_TYPE
Match on layer three protocol. ETH_TYPE may be either ipv4,ipv6 or an unsigned 16bit value in hexadecimal format.
ip_proto IP_PROTO
Match on layer four protocol. IP_PROTO may be either tcp,udp or an unsigned 8bit value in hexadecimal format.
dst_ip ADDRESS
src_ip ADDRESS Match on source or destination IP address. ADDRESS must be a valid IPv4 or IPv6 address, depending on ether_type, which has to be specified in beforehand.
dst_port NUMBER
src_port NUMBER Match on layer 4 protocol source or destination port number. Only available for ip_proto values udp and tcp, which has to be specified in beforehand.


As stated above where applicable, matches of a certain layer implicitly depend on the matches of the next lower layer. Precisely, layer one and two matches ( indev,dst_mac,src_mac and eth_type) have no dependency, layer three matches ( ip_proto,dst_ip and src_ip) require eth_type being set to either ipv4 or ipv6, and finally layer four matches ( dst_port and src_port) depend on ip_proto being set to either tcp or udp.

There can be only used one mask per one prio. If user needs to specify different mask, he has to use different prio.