tc-ife

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 meta-
       data, which is then decapsulated by the receiving end. The sender  runs
       in  encoding  mode and the receiver in decode mode. Both sender and re-
       ceiver must specify the same ethertype. In  the  future,  a  registered
       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 speci-
              fied.

       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  des-
       tination  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)