mirror of
https://github.com/xtaci/kcp-go.git
synced 2024-04-21 12:32:15 +00:00
83 lines
2.7 KiB
Lua
83 lines
2.7 KiB
Lua
-- create protocol
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kcp_protocol = Proto("KCP", "KCP Protocol")
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-- fields for kcp
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conv = ProtoField.uint32("kcp.conv", "conv", base.DEC)
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cmd = ProtoField.uint8("kcp.cmd", "cmd", base.DEC)
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frg = ProtoField.uint8("kcp.frg", "frg", base.DEC)
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wnd = ProtoField.uint16("kcp.wnd", "wnd", base.DEC)
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ts = ProtoField.uint32("kcp.ts", "ts", base.DEC)
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sn = ProtoField.uint32("kcp.sn", "sn", base.DEC)
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una = ProtoField.uint32("kcp.una", "una", base.DEC)
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len = ProtoField.uint32("kcp.len", "len", base.DEC)
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kcp_protocol.fields = {conv, cmd, frg, wnd, ts, sn, una, len}
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-- dissect each udp packet
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function kcp_protocol.dissector(buffer, pinfo, tree)
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length = buffer:len()
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if length == 0 then
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return
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end
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local offset_s = 8
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local first_sn = buffer(offset_s + 12, 4):le_int()
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local first_len = buffer(offset_s + 20, 4):le_int()
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local first_cmd_name = get_cmd_name(buffer(offset_s + 4, 1):le_int())
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local info = string.format("[%s] Sn=%d Kcplen=%d", first_cmd_name, first_sn, first_len)
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pinfo.cols.protocol = kcp_protocol.name
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udp_info = string.gsub(tostring(pinfo.cols.info), "Len", "Udplen", 1)
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pinfo.cols.info = string.gsub(udp_info, " U", info .. " U", 1)
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-- dssect multi kcp packet in udp
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local offset = 8
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while offset < buffer:len() do
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local conv_buf = buffer(offset + 0, 4)
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local cmd_buf = buffer(offset + 4, 1)
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local wnd_buf = buffer(offset + 6, 2)
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local sn_buf = buffer(offset + 12, 4)
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local len_buf = buffer(offset + 20, 4)
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local cmd_name = get_cmd_name(cmd_buf:le_int())
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local data_len = len_buf:le_int()
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local tree_title =
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string.format(
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"KCP Protocol, %s, Sn: %d, Conv: %d, Wnd: %d, Len: %d",
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cmd_name,
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sn_buf:le_int(),
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conv_buf:le_int(),
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wnd_buf:le_int(),
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data_len
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)
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local subtree = tree:add(kcp_protocol, buffer(), tree_title)
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subtree:add_le(conv, conv_buf)
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subtree:add_le(cmd, cmd_buf):append_text(" (" .. cmd_name .. ")")
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subtree:add_le(frg, buffer(offset + 5, 1))
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subtree:add_le(wnd, wnd_buf)
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subtree:add_le(ts, buffer(offset + 8, 4))
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subtree:add_le(sn, sn_buf)
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subtree:add_le(una, buffer(offset + 16, 4))
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subtree:add_le(len, len_buf)
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offset = offset + 24 + data_len
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end
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end
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function get_cmd_name(cmd_val)
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if cmd_val == 81 then
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return "PSH"
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elseif cmd_val == 82 then
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return "ACK"
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elseif cmd_val == 83 then
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return "ASK"
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elseif cmd_val == 84 then
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return "TELL"
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end
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end
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-- register kcp dissector to udp
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local udp_port = DissectorTable.get("udp.port")
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-- replace 8081 to the port for kcp
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udp_port:add(8081, kcp_protocol)
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