73 lines
1.8 KiB
Elixir
73 lines
1.8 KiB
Elixir
defmodule Pf do
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use GenServer
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import Record
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# Extract Erlang record for msantos/pkt
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for {name, schema} <- extract_all(from_lib: "pkt/include/pkt.hrl") do
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defrecord(name, schema)
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end
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defmodule State do
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defstruct [
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ifname: nil,
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pcap_ref: nil,
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tester_pid: nil
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]
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end
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def inject!(pid, packet, payload \\ "") do
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GenServer.cast(pid, {:inject, {packet, payload}})
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end
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def stop(pid) do
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GenServer.cast(pid, :stop)
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end
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def start_link(ifname) do
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ifname = String.to_charlist(ifname)
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GenServer.start_link(__MODULE__, [ifname, self()])
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end
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def init([ifname, tester_pid]) do
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{:ok, init_pf(ifname, tester_pid)}
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end
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def handle_cast({:inject, {headers, payload}}, state) do
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headers_bin = for header <- headers do
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case header do
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ether() -> :pkt.ether(header)
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{:"802.1q", _, _, _, _} = vlan -> :pkt_802_1q.codec(vlan)
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arp() -> :pkt.arp(header)
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ipv4() -> :pkt.ipv4(header)
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lldp() -> :pkt.lldp(header)
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udp() -> :pkt.udp(header)
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tcp() -> :pkt.tcp(header)
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end
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end
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binary = Enum.join(headers_bin, "")
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:epcap.send(state.pcap_ref, <<binary::bytes, payload::bytes>>)
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{:noreply, state}
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end
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def handle_cast(:stop, state) do
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{:stop, :normal, state}
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end
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def handle_cast(_req, state) do
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{:noreply, state}
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end
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def handle_info({:packet, _dlt, _time, _len, data}, state) do
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pkt = :pkt.decapsulate(data)
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send(state.tester_pid, {to_string(state.ifname), pkt})
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{:noreply, state}
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end
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def handle_info(_info, state) do
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{:noreply, state}
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end
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# private functions
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defp init_pf(ifname, tester_pid) do
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{:ok, epcap_pid} = :epcap.start_link(interface: ifname, promiscuous: true, inject: true)
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%State{pcap_ref: epcap_pid, ifname: ifname, tester_pid: tester_pid}
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end
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end
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