IFE action in tc(8)                                                    Linux                                                   IFE action in tc(8)

NAME

       IFE - encapsulate/decapsulate metadata

SYNOPSIS

       tc ...  action ife DIRECTION [ ACTION ] [ dst DMAC ] [ src SMAC ] [ type TYPE ] [ CONTROL ] [ index INDEX ]

       DIRECTION := { decode | encode }

       ACTION := { allow ATTR | use ATTR value }

       ATTR := { mark | prio | tcindex }

       CONTROL := { reclassify | use | pipe | drop | continue | ok | goto chain CHAIN_INDEX }

DESCRIPTION

       The  ife  action  allows  for a sending side to encapsulate arbitrary metadata, which is then decapsulated by the receiving end. The sender
       runs in encoding mode and the receiver in decode mode. Both sender and receiver must specify the same ethertype. In the  future,  a  regis-
       tered ethertype may be available as a default.

OPTIONS

       decode For the receiving side; decode the metadata if the packet matches.

       encode For the sending side. Encode the specified metadata if the packet matches.

       allow  Encode direction only. Allows encoding specified metadata.

       use    Encode direction only. Enforce static encoding of specified metadata.

       mark [ u32_value  ] The value to set for the skb mark. The u32 value is required only when use is specified. If mark value is zero, it will
              not be encoded, instead "overlimits" statistics increment and CONTROL action is taken.

       prio [ u32_value ] The value to set for priority in the skb structure. The u32 value is required only when use is specified.

       tcindex [
              u16_value ] Value to set for the traffic control index in the skb structure. The u16 value is required only when use is specified.

       dmac DMAC
       smac SMAC
              Optional six byte destination or source MAC address to encode.

       type TYPE
              Optional 16-bit ethertype to encode. If not specified value of 0xED3E will be used.

       CONTROL
              Action to take following an encode/decode.

       index INDEX
              Assign a unique ID to this action instead of letting the kernel choose one automatically.  INDEX is a 32bit unsigned integer greater
              than zero.

EXAMPLES

       On  the receiving side, match packets with ethertype 0xdead and restart classification so that it will match ICMP on the next rule, at prio
       3:
              # tc qdisc add dev eth0 handle ffff: ingress
              # tc filter add dev eth0 parent ffff: prio 2 protocol 0xdead 
                   u32 match u32 0 0 flowid 1:1 
                   action ife decode reclassify
              # tc filter add dev eth0 parent ffff: prio 3 protocol ip 
                   u32 match ip protocol 0xff flowid 1:1 
                   action continue

       Match with skb mark of 17:

              # tc filter add dev eth0 parent ffff: prio 4 protocol ip 
                   handle 0x11 fw flowid 1:1 
                   action ok

       Configure the sending side to encode for the filters above. Use a destination IP address of 192.168.122.237/24, then tag with skb  mark  of
       decimal  17.  Encode  the  packaet  with ethertype 0xdead, add skb->mark to whitelist of metadatum to send, and rewrite the destination MAC
       address to 02:15:15:15:15:15.

              # tc qdisc add dev eth0 root handle 1: prio
              # tc filter add dev eth0 parent 1: protocol ip prio 10 u32 
                   match ip dst 192.168.122.237/24 
                   match ip protocol 1 0xff 
                   flowid 1:2 
                   action skbedit mark 17 
                   action ife encode 
                   type 0xDEAD 
                   allow mark 
                   dst 02:15:15:15:15:15

SEE ALSO

       tc(8), tc-u32(8)

iproute2                                                            22 Apr 2016                                                IFE action in tc(8)