From 0e79655bbdcfec45431f809a66bb309a17115211 Mon Sep 17 00:00:00 2001
From: Jeffrey Phillips Freeman <jeffrey.freeman@syncleus.com>
Date: Sat, 1 Oct 2016 12:19:36 -0400
Subject: [PATCH] Added APRSKiss class and finished implementing its methods.
---
lib/aprs/aprs_kiss.rb | 148 ++++++++++++++++++++++++++++++++++++++++
lib/kiss/kiss_serial.rb | 2 +-
2 files changed, 149 insertions(+), 1 deletion(-)
create mode 100644 lib/aprs/aprs_kiss.rb
diff --git a/lib/aprs/aprs_kiss.rb b/lib/aprs/aprs_kiss.rb
new file mode 100644
index 0000000..8433b6f
--- /dev/null
+++ b/lib/aprs/aprs_kiss.rb
@@ -0,0 +1,148 @@
+require_relative '../kiss/constants'
+
+module APRS
+ class APRSKiss
+
+ protected
+ def initialize(data_stream)
+ @data_stream = data_stream
+ @lock = Mutex.new
+ end
+
+ private
+ def self.decode_frame(raw_frame)
+ frame = {}
+ frame_len = raw_frame.length
+
+ if frame_len > 16
+ (0...frame_len - 2).each do |raw_slice|
+ # Is address field length correct?
+ if raw_frame[raw_slice] & 0x01 and ((raw_slice + 1) % 7) == 0
+ i = (raw_slice.to_f + 1.0) / 7.0
+ # Less than 2 callsigns?
+ if 1.0 < i < 11.0
+ if raw_frame[raw_slice + 1] & 0x03 == 0x03 and [0xf0, 0xcf].include? raw_frame[raw_slice + 2]
+ text_as_array = raw_frame[raw_slice + 3..-1].map { |b| chr(b) }
+ frame['text'] = text_as_array.join
+ frame['destination'] = identity_as_string(extract_callsign(raw_frame))
+ frame['source'] = identity_as_string(__extract_callsign(raw_frame[7..-1]))
+ frame['path'] = extract_path(i.to_i, raw_frame)
+ return frame
+ end
+ end
+ end
+ end
+ end
+ frame
+ end
+
+ private
+ def self.extract_path(start, raw_frame)
+ full_path = []
+
+ (2...start).each do |i|
+ path = identity_as_string(extract_callsign(raw_frame[i * 7..-1]))
+ if path
+ if raw_frame[i * 7 + 6] & 0x80
+ full_path << [path, '*'].join
+ else
+ full_path << path
+ end
+ end
+ end
+ full_path
+ end
+
+ private
+ def self.extract_callsign(raw_frame)
+ callsign_as_array = raw_frame[0...6].map { |x| chr(x >> 1) }
+ callsign = callsign_as_array.join.strip
+ ssid = (raw_frame[6] >> 1) & 0x0f
+ return {'callsign': callsign, 'ssid': ssid}
+ end
+
+ private
+ def self.identity_as_string(identity)
+ if identity['ssid'] > 0
+ return [identity['callsign'], identity['ssid'].to_s].join('-')
+ else
+ return identity['callsign']
+ end
+ end
+
+ private
+ def self.encode_frame(frame)
+ enc_frame = encode_callsign(parse_identity_string(frame['destination'])) + encode_callsign(parse_identity_string(frame['source']))
+ frame['path'].each do |p|
+ enc_frame += encode_callsign(parse_identity_string(p))
+ end
+
+ return enc_frame[0..-1] + [enc_frame[-1] | 0x01] + [KISS::SLOT_TIME] + [0xf0] + frame['text'].map { |c| ord(c) }
+ end
+
+ private
+ def self.encode_callsign(callsign)
+ call_sign = callsign['callsign']
+
+ enc_ssid = (callsign['ssid'] << 1) | 0x60
+
+ if call_sign.include? '*'
+ call_sign.gsub!(/\*/,'')
+ enc_ssid |= 0x80
+ end
+
+ while call_sign.length < 6
+ call_sign = [call_sign, ' '].join
+ end
+
+ return call_sign.map { |p| ord(p) << 1 } + [enc_ssid]
+ end
+
+ private
+ def self.parse_identity_string(identity_string)
+ # If we are parsing a spent token then first lets get rid of the astresick suffix.
+ if identity_string[-1] == '*'
+ identity_string = identity_string[0..-1]
+ end
+
+ if identity_string.include? '-'
+ call_sign, ssid = identity_string.split('-')
+ else
+ call_sign = identity_string
+ ssid = 0
+ end
+
+ return {'callsign': call_sign, 'ssid': int(ssid)}
+ end
+
+ public
+ def connect(*args, **kwargs)
+ @data_stream.connect(*args, **kwargs)
+ end
+
+ public
+ def close(*args, **kwargs)
+ @data_stream.close(*args, **kwargs)
+ end
+
+ public
+ def write(frame, *args, **kwargs)
+ @lock.synchronize do
+ encoded_frame = encode_frame(frame)
+ @data_stream.write(encoded_frame, *args, **kwargs)
+ end
+ end
+
+ public
+ def read(*args, **kwargs)
+ @lock.synchronize do
+ frame = @data_stream.read(*args, **kwargs)
+ if frame&.length
+ return decode_frame(frame)
+ else
+ return nil
+ end
+ end
+ end
+ end
+end
\ No newline at end of file
diff --git a/lib/kiss/kiss_serial.rb b/lib/kiss/kiss_serial.rb
index b61d182..c69468b 100644
--- a/lib/kiss/kiss_serial.rb
+++ b/lib/kiss/kiss_serial.rb
@@ -17,7 +17,7 @@ module KISS
read_bytes=DEFAULT_READ_BYTES,
strip_df_start=true)
super(strip_df_start)
-
+
@com_port = com_port
@baud = baud
@parity = parity
--
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