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Flower filter in tc

Section: Linux (8)
Updated: 22 Oct 2015
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NAME

flower - flow based traffic control filter

SYNOPSIS

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

MATCH_LIST := [ MATCH_LIST ] MATCH

MATCH := { indev ifname | skip_sw | skip_hw | { dst_mac | src_mac } MASKED_LLADDR | vlan_id VID | vlan_prio PRIORITY | vlan_ethtype { ipv4 | ipv6 | ETH_TYPE } | ip_proto { tcp | udp | sctp | icmp | icmpv6 | IP_PROTO } | ip_tos MASKED_IP_TOS | ip_ttl MASKED_IP_TTL | { dst_ip | src_ip } PREFIX | { dst_port | src_port } port_number } | tcp_flags MASKED_TCP_FLAGS | type MASKED_TYPE | code MASKED_CODE | { arp_tip | arp_sip } IPV4_PREFIX | arp_op { request | reply | OP } | { arp_tha | arp_sha } MASKED_LLADDR | enc_key_id KEY-ID | { enc_dst_ip | enc_src_ip } { ipv4_address | ipv6_address } | enc_dst_port port_number | ip_flags IP_FLAGS

DESCRIPTION

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.

OPTIONS

action ACTION_SPEC: 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.
skip_sw: Do not process filter by software. If hardware has no offload support for this filter, or TC offload is not enabled for the interface, operation will fail.
skip_hw: Do not process filter by hardware.
dst_mac MASKED_LLADDR: src_mac MASKED_LLADDR Match on source or destination MAC address. A mask may be optionally provided to limit the bits of the address which are matched. A mask is provided by following the address with a slash and then the mask. It may be provided in LLADDR format, in which case it is a bitwise mask, or as a number of high bits to match. If the mask is missing then a match on all bits is assumed.
vlan_id VID: Match on vlan tag id. VID is an unsigned 12bit value in decimal format.
vlan_prio PRIORITY: Match on vlan tag priority. PRIORITY is an unsigned 3bit value in decimal format.
vlan_ethtype VLAN_ETH_TYPE: Match on layer three protocol. VLAN_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 tcp, udp, sctp, icmp, icmpv6 or an unsigned 8bit value in hexadecimal format.
ip_tos MASKED_IP_TOS: Match on ipv4 TOS or ipv6 traffic-class - eight bits in hexadecimal format. A mask may be optionally provided to limit the bits which are matched. A mask is provided by following the value with a slash and then the mask. If the mask is missing then a match on all bits is assumed.
ip_ttl MASKED_IP_TTL: Match on ipv4 TTL or ipv6 hop-limit - eight bits value in decimal or hexadecimal format. A mask may be optionally provided to limit the bits which are matched. Same logic is used for the mask as with matching on ip_tos.
dst_ip PREFIX: src_ip PREFIX Match on source or destination IP address. PREFIX must be a valid IPv4 or IPv6 address, depending on the protocol option to tc filter, optionally followed by a slash and the prefix length. If the prefix is missing, tc assumes a full-length host match.
dst_port NUMBER: src_port NUMBER Match on layer 4 protocol source or destination port number. Only available for ip_proto values udp, tcp and sctp which have to be specified in beforehand.
tcp_flags MASKED_TCP_FLAGS: Match on TCP flags represented as 12bit bitfield in in hexadecimal format. A mask may be optionally provided to limit the bits which are matched. A mask is provided by following the value with a slash and then the mask. If the mask is missing then a match on all bits is assumed.
type MASKED_TYPE: code MASKED_CODE Match on ICMP type or code. A mask may be optionally provided to limit the bits of the address which are matched. A mask is provided by following the address with a slash and then the mask. The mask must be as a number which represents a bitwise mask If the mask is missing then a match on all bits is assumed. Only available for ip_proto values icmp and icmpv6 which have to be specified in beforehand.
arp_tip IPV4_PREFIX: arp_sip IPV4_PREFIX Match on ARP or RARP sender or target IP address. IPV4_PREFIX must be a valid IPv4 address optionally followed by a slash and the prefix length. If the prefix is missing, tc assumes a full-length host match.
arp_op ARP_OP: Match on ARP or RARP operation. ARP_OP may be request, reply or an integer value 0, 1 or 2. A mask may be optionally provided to limit the bits of the operation which are matched. A mask is provided by following the address with a slash and then the mask. It may be provided as an unsigned 8 bit value representing a bitwise mask. If the mask is missing then a match on all bits is assumed.
arp_sha MASKED_LLADDR: arp_tha MASKED_LLADDR Match on ARP or RARP sender or target MAC address. A mask may be optionally provided to limit the bits of the address which are matched. A mask is provided by following the address with a slash and then the mask. It may be provided in LLADDR format, in which case it is a bitwise mask, or as a number of high bits to match. If the mask is missing then a match on all bits is assumed.
enc_key_id NUMBER: enc_dst_ip PREFIX enc_src_ip PREFIX enc_dst_port NUMBER Match on IP tunnel metadata. Key id NUMBER is a 32 bit tunnel key id (e.g. VNI for VXLAN tunnel). PREFIX must be a valid IPv4 or IPv6 address optionally followed by a slash and the prefix length. If the prefix is missing, tc assumes a full-length host match. Dst port NUMBER is a 16 bit UDP dst port.
ip_flags IP_FLAGS: IP_FLAGS may be either frag or nofrag to match on fragmented packets or not respectively.

NOTES

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 and src_mac) have no dependency, layer three matches (ip_proto, dst_ip, src_ip, arp_tip, arp_sip, arp_op, arp_tha, arp_sha and ip_flags) depend on the protocol option of tc filter, layer four port matches (dst_port and src_port) depend on ip_proto being set to tcp, udp or sctp, and finally ICMP matches (code and type) depend on ip_proto being set to icmp or icmpv6. There can be only used one mask per one prio. If user needs to specify different mask, he has to use different prio.