50 lines
1.3 KiB
Lua
Executable file
50 lines
1.3 KiB
Lua
Executable file
#!/usr/bin/env dnsjit
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local pcap_in = arg[2]
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local pcap_out = arg[3]
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if pcap_in == nil or pcap_out == nil then
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print("usage: "..arg[1].." <pcap in> <pcap out>")
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return
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end
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local object = require("dnsjit.core.objects")
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local input = require("dnsjit.input.pcap").new()
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local layer = require("dnsjit.filter.layer").new()
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local dns = require("dnsjit.core.object.dns").new()
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local output = require("dnsjit.output.pcap").new()
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input:open_offline(pcap_in)
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layer:producer(input)
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local producer, ctx = layer:produce()
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output:open(pcap_out, input:linktype(), input:snaplen())
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local receiver, rctx = output:receive()
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local n = 0
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while true do
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local obj = producer(ctx)
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if obj == nil then break end
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local pl = obj:cast()
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if obj:type() == "payload" and pl.len > 0 then
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local protocol = obj.obj_prev
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while protocol ~= nil do
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if protocol.obj_type == object.UDP or protocol.obj_type == object.TCP then
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break
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end
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protocol = protocol.obj_prev
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end
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dns:reset()
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if protocol ~= nil and protocol.obj_type == object.TCP then
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dns.includes_dnslen = 1
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end
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dns.obj_prev = obj
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if dns:parse_header() == 0 then
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receiver(rctx, obj)
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n = n + 1
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end
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end
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end
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output:close()
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print(n, "DNS packets dumped")
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