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feat: support ackrej
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‎aprs_backend/packets/ackrej.py

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# Parses packets to check for new ackrej format packets
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import re
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import logging
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log = logging.getLogger(__name__)
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def parse_ack_rej_msg_id(message: str) -> tuple[str | None, str | None, str | None, str | None]:
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"""Parses the "new" (1999) ackrej message format. APRSlib doesn't
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handle it very well
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Args:
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message (str): APRS message text to be parsed. If this text contains
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the new ack/rej message as _sole_ data, then the response_text field
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will be populated with the ack/rej, the message numbers will be assigned
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and the message_text itself will be None. Otherwise, the original
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message text will be returned
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Returns:
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tuple[str, str, str, str]:
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message: str | None - original message text or None if message was an ack/rej
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response: str | None - ack, rej, or None
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sender_message_id: str | None - Sender's message ID or None
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err_message_id: str | None - message id for a message from te bot or None
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"""
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matches = re.search(r"^(ack|rej)(..)}(..)$", message, re.IGNORECASE)
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response = None
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sender_message_id = None
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err_message_id = None
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if matches:
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response = matches[1]
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sender_message_id = matches[2]
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err_message_id = matches[3]
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message = None
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log.debug("Message: %s response: %s sender_message_id: %s, err_message_id: %s", message, response, sender_message_id, err_message_id)
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return message, response
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def parse_new_ackrej_format(message: str) -> tuple[str | None, str | None, bool]:
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"""
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Have a look at the incoming APRS message and check if it
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contains a message no which does not follow the APRS
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standard (see aprs101.pdf chapter 14)
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http://www.aprs.org/aprs11/replyacks.txt
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but rather follow the new format
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http://www.aprs.org/aprs11/replyacks.txt
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Parameters
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==========
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message_text: 'str'
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The original aprs message as originally extracted by aprslib
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Returns
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=======
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msg: 'str'
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original message OR the modified message minus message no and trailing
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data
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msg_no: 'str'
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Null if no message_no was present
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new_ackrej_format: 'bool'
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True if the ackrej_format has to follow the new ack-rej handling
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process as described in http://www.aprs.org/aprs11/replyacks.txt
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"""
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"""
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The following assumptions apply when handling APRS messages in general:
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Option 1: no message ID present:
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send no ACK
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outgoing messages have no msg number attachment
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Example data exchange 1:
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DF1JSL-4>APRS,TCPIP*,qAC,T2PRT::WXBOT :94043
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WXBOT>APRS,qAS,KI6WJP::DF1JSL-4 :Mountain View CA. Today,Sunny High 60
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Example data exchange 2:
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DF1JSL-4>APRS,TCPIP*,qAC,T2SPAIN::EMAIL-2 :jsl24469@gmail.com Hallo
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EMAIL-2>APJIE4,TCPIP*,qAC,AE5PL-JF::DF1JSL-4 :Email sent to jsl24469@gmail.com
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Option 2: old message number format is present: (example: msg{12345)
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Send ack with message number from original message (ack12345)
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All outgoing messages have trailing msg number ( {abcde ); can be numeric or
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slphanumeric counter. See aprs101.pdf chapter 14
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Example data exchange 1:
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DF1JSL-4>APRS,TCPIP*,qAC,T2SP::EMAIL-2 :jsl24469@gmail.com Hallo{12345
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EMAIL-2>APJIE4,TCPIP*,qAC,AE5PL-JF::DF1JSL-4 :ack12345
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EMAIL-2>APJIE4,TCPIP*,qAC,AE5PL-JF::DF1JSL-4 :Email sent to jsl24469@gmail.com{891
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DF1JSL-4>APOSB,TCPIP*,qAS,DF1JSL::EMAIL-2 :ack891
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Example data exchange 2:
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DF1JSL-4>APRS,TCPIP*,qAC,T2CSNGRAD::EMAIL-2 :jsl24469@gmail.com{ABCDE
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EMAIL-2>APJIE4,TCPIP*,qAC,AE5PL-JF::DF1JSL-4 :ackABCDE
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EMAIL-2>APJIE4,TCPIP*,qAC,AE5PL-JF::DF1JSL-4 :Email sent to jsl24469@gmail.com{893
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DF1JSL-4>APOSB,TCPIP*,qAS,DF1JSL::EMAIL-2 :ack893
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Option 3: new messages with message ID but without trailing retry msg ids: msg{AB}
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Do NOT send extra ack
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All outgoing messages have 2-character msg id, followed by message ID from original message
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Example:
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User sends message "Hello{AB}" to MPAD
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MPAD responds "Message content line 1{DE}AB" to user
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MPAD responds "Message content line 2{DF}AB" to user
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AB -> original message
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DE, DF -> message IDs generated by MPAD
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Example data exchange 1:
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DF1JSL-4>APRS,TCPIP*,qAC,T2NUERNBG::WXBOT :99801{AB}
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WXBOT>APRS,qAS,KI6WJP::DF1JSL-4 :Lemon Creek AK. Today,Scattered Rain/Snow and Patchy Fog 50% High 4{QL}AB
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DF1JSL-4>APOSB,TCPIP*,qAS,DF1JSL::WXBOT :ackQL}AB
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WXBOT>APRS,qAS,KI6WJP::DF1JSL-4 :0{QM}AB
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DF1JSL-4>APOSB,TCPIP*,qAS,DF1JSL::WXBOT :ackQM}AB
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Example data exchange 2:
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DF1JSL-4>APRS,TCPIP*,qAC,T2SPAIN::EMAIL-2 :jsl24469@gmail.com Hallo{AB}
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EMAIL-2>APJIE4,TCPIP*,qAC,AE5PL-JF::DF1JSL-4 :Email sent to jsl24469@gmail.com{OQ}AB
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DF1JSL-4>APOSB,TCPIP*,qAS,DF1JSL::EMAIL-2 :ackOQ}AB
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Option 4: new messages with message ID and with trailing retry msg ids: msg{AB}CD
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We don't handle retries - therefore, apply option #3 for processing these
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the "CD" part gets omitted and is not used
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Example data exchange 1:
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DF1JSL-4>APRS,TCPIP*,qAC,T2CZECH::WXBOT :99801{LM}AA
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WXBOT>APRS,qAS,KI6WJP::DF1JSL-4 :Lemon Creek AK. Today,Scattered Rain/Snow and Patchy Fog 50% High 4{QP}LM
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DF1JSL-4>APOSB,TCPIP*,qAS,DF1JSL::WXBOT :ackQP}LM
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WXBOT>APRS,qAS,KI6WJP::DF1JSL-4 :0{QQ}LM
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DF1JSL-4>APOSB,TCPIP*,qAS,DF1JSL::WXBOT :ackQQ}LM
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Example data exchange 2:
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DF1JSL-4>APRS,TCPIP*,qAC,T2SP::EMAIL-2 :jsl24469@gmail.com Welt{DE}FG
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EMAIL-2>APJIE4,TCPIP*,qAC,AE5PL-JF::DF1JSL-4 :Email sent to jsl24469@gmail.com{OS}DE
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DF1JSL-4>APOSB,TCPIP*,qAS,DF1JSL::EMAIL-2 :ackOS}DE
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"""
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msg = msgno = None
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new_ackrej_format = False
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# if message text is present, split up between aaaaaa{bb}cc
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# where aaaaaa = message text
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# bb = message number
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# cc = message retry (may or may not be present)
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if message:
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matches = re.search(
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r"^(.*){([a-zA-Z0-9]{2})}(\w*)$", message, re.IGNORECASE
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)
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if matches:
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try:
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msg = matches[1].rstrip()
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msgno = matches[2]
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new_ackrej_format = True
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except IndexError:
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msg = message
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msgno = None
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new_ackrej_format = False
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else:
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msg = message
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else:
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msg = message
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return msg, msgno, new_ackrej_format

‎aprs_backend/threads/rx.py

Lines changed: 82 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -7,6 +7,7 @@
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from aprs_backend.packets.list import ErrbotPacketList
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from aprs_backend.threads import ErrbotAPRSDThread
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from aprsd import packets
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from aprs_backend.packets.ackrej import parse_ack_rej_msg_id, parse_new_ackrej_format
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import logging
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@@ -69,9 +70,87 @@ def process_packet(self, *args, **kwargs):
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"""
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packet = self._client.decode_packet(*args, **kwargs)
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packet.log(header="RX")
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print(packet)
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if isinstance(packet, packets.AckPacket):
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# We don't need to drop AckPackets, those should be
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log.debug(packet)
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# Check if this packet is in the new ack-rej format
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# arpslib cannot handle these messages properly so we have to apply a workaround
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# as we don't resubmit data in case it hasn't been received
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response = None
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if isinstance(packet, packets.MessagePacket):
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if packet.message_text is not None and packet.message_text != "":
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packet.message_text, response = parse_ack_rej_msg_id(packet.message_text)
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# This is a special handler for the new(er) APRS ack/rej/format
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# By default (and described in aprs101.pdf pg. 71), APRS supports two
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# messages:
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# - messages withOUT message ID, e.g. Hello World
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# - message WITH 5-character message ID, e.g. Hello World{12345
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# The latter require the program to send a seperate ACK to the original
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# recipient
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#
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# Introduced through an addendum (http://www.aprs.org/aprs11/replyacks.txt),
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# a third option came into place. This message also has a message ID but
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# instead of sending a separate ACK, the original message ID is returned to
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# the user for all messages that relate to the original one. aprslib does
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# currently not recognise these new message IDs - therefore, we need to
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# extract them from the message text and switch the program logic if we
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# discover that new ID.
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is_new_ackrej = False
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if packet.msgNo is None and packet.message_text is not None:
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packet.message_text, packet.msgNo, is_new_ackrej = parse_new_ackrej_format(packet.message_text)
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log.debug("Message %s is_new_ackrej %s", packet, is_new_ackrej)
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if response == "ack":
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log.debug("Packet is new style ack, transforming")
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new_packet = packets.AckPacket(
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from_call = packet.from_call,
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to_call = packet.to_call,
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addresse = packet.addresse,
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format = packet.format,
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msgNo = packet.msgNo,
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packet_type = packet.packet_type,
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timestamp = packet.timestamp,
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raw = packet.raw,
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raw_dict = packet.raw_dict,
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payload = packet.payload,
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send_count = packet.send_count,
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retry_count = packet.retry_count,
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last_send_time = packet.last_send_time,
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last_send_attempt = packet.last_send_attempt,
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allow_delay = packet.allow_delay,
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path = packet.path,
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via = packet.va,
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response = response
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)
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packet = new_packet
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if response == "rej":
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log.debug("Packet is new style rejection, transforming")
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new_packet = packets.RejectPacket(
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from_call = packet.from_call,
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to_call = packet.to_call,
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addresse = packet.addresse,
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format = packet.format,
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msgNo = packet.msgNo,
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packet_type = packet.packet_type,
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timestamp = packet.timestamp,
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raw = packet.raw,
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raw_dict = packet.raw_dict,
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payload = packet.payload,
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send_count = packet.send_count,
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retry_count = packet.retry_count,
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last_send_time = packet.last_send_time,
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last_send_attempt = packet.last_send_attempt,
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allow_delay = packet.allow_delay,
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path = packet.path,
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via = packet.va,
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response = response
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)
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packet = new_packet
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if isinstance(packet, packets.AckPacket) or isinstance(packet, packets.RejectPacket):
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# We don't need to drop AckPackets of Rejects, those should be
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# processed.
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self.packet_queue.put(packet)
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else:

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