Module: PWN::SDR::Decoder::LoRa

Defined in:
lib/pwn/sdr/decoder/lora.rb

Overview

LoRa / LoRaWAN CSS decoder for the 433 / 868 / 902–928 MHz ISM allocations. Chirp-spread-spectrum needs raw I/Q, so this drives rtl_433 (which ships a native LoRa demod, protocol #264) directly. Emits one JSON line per decoded uplink containing SF/BW/CR, DevAddr, FCnt, and raw PHYPayload hex.

Class Method Summary collapse

Class Method Details

.authors ⇒ Object

Author(s)

0day Inc. support@0dayinc.com



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# File 'lib/pwn/sdr/decoder/lora.rb', line 65

public_class_method def self.authors
  "AUTHOR(S):\n  0day Inc. <support@0dayinc.com>\n"
end

.decode(opts = {}) ⇒ Object

Supported Method Parameters

PWN::SDR::Decoder::LoRa.decode( freq_obj: 'required - freq_obj returned from PWN::SDR::GQRX.init_freq' )



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# File 'lib/pwn/sdr/decoder/lora.rb', line 20

public_class_method def self.decode(opts = {})
  freq_obj = opts[:freq_obj]
  raise 'ERROR: :freq_obj is required' unless freq_obj.is_a?(Hash)

  hz       = PWN::SDR.hz_to_i(freq: freq_obj[:freq])
  sdr_args = freq_obj[:sdr_args].to_s

  cmd = ['rtl_433', '-f', hz.to_s, '-s', '1024k',
         '-R', '264', '-F', 'json', '-M', 'level']
  cmd.push('-d', sdr_args) unless sdr_args.empty?

  PWN::SDR::Decoder::Base.run_pipeline(
    freq_obj: freq_obj,
    protocol: 'LoRa',
    required_bins: %w[rtl_433],
    direct_cmd: Shellwords.join(cmd),
    line_match: /^\s*{/,
    parser: proc { |line| parse_line(line: line) }
  )
end

.help ⇒ Object

Display Usage for this Module



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# File 'lib/pwn/sdr/decoder/lora.rb', line 71

public_class_method def self.help
  puts "USAGE:
    #{self}.decode(
      freq_obj: 'required - freq_obj returned from PWN::SDR::GQRX.init_freq'
    )

    NOTE: Requires `rtl_433` >= 23.x (native LoRa demod). Owns SDR.

    #{self}.parse_line(line: '{\"model\":\"LoRa\",\"sf\":7,\"bw\":125,...}')

    #{self}.authors
  "
end

.parse_line(opts = {}) ⇒ Object

Supported Method Parameters

PWN::SDR::Decoder::LoRa.parse_line(line: '"model":"LoRa",...')



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# File 'lib/pwn/sdr/decoder/lora.rb', line 44

public_class_method def self.parse_line(opts = {})
  line = opts[:line].to_s
  h = begin
    JSON.parse(line, symbolize_names: true)
  rescue StandardError
    { unparsed: line }
  end
  out = { protocol: 'LoRa' }.merge(h)
  bits = []
  bits << "SF#{out[:sf]}" if out[:sf]
  bits << "BW#{out[:bw]}" if out[:bw]
  bits << "CR#{out[:cr]}" if out[:cr]
  bits << "DevAddr=#{out[:devaddr] || out[:id]}" if out[:devaddr] || out[:id]
  bits << "FCnt=#{out[:fcnt]}" if out[:fcnt]
  bits << "len=#{out[:len] || (out[:data].to_s.length / 2)}" if out[:len] || out[:data]
  out[:summary] = "LoRa #{bits.join(' ')}".strip
  out
end