MFC r316434:
Add O_EXTERNAL_DATA opcode support. This opcode can be used to attach some data to external action opcode. And unlike to O_EXTERNAL_INSTANCE opcode, this opcode does not require creating of named instance to pass configuration arguments to external action handler. The data is coming just next to O_EXTERNAL_ACTION opcode. The userlevel part currenly supports formatting for opcode with ipfw_insn size, by default it expects u16 numeric value in the arg1. Obtained from: Yandex LLC Sponsored by: Yandex LLC