[aprssig] Venting about malformed packets

[John Gorkos]

I was just spending some quality time relearning Java while updating 
JavAPRSLib (now with weather packet parsing!), and I just want to claw 
my eyes out at the number of malformed packets that traverse APRS-IS.  
By my eyeball count, between 2 and 4% of all transmitted packets are 
malformed.

Of those, almost all are "hand entered" station info, and most of those 
are bad lat/lons (too many digits, not enough digits, etc). Just 
carelessness.  Other than a RadioSonde decoder that I already filed an 
issue against, I don't see any software-induced errors, so kudos to the 
devs out there.

if you're bored and reading this, here's  a list of the 34 bad packets 
from the last 1000 I pulled off APRS-IS.  Feel free to look through and 
point out any that ARE legitimately parsable and I'll fix my code.  Yes, 
this is a shameless, cheap way of getting free help debugging my code.

WD4HMR-7>MBX,N4YOT-1*,WIDE1-1,WIDE2-1,qAO,N5BXP-2:Mail for: ALL
VE7KU-15>UIDIGI,qAR,VA7DWC-1:UIDIGI 1.9
G0TAI-3>BEACON,qAR,MB7UMK-10:Ian, Great Linford, Milton Keynes.
KC5YOC-1>APTT4,W5FOW-2,WIDE1*,WIDE2-1,qAR,NY5V-1:none
VK4FSD-9>APTT4,VK4RMC-3,WIDE1*,WIDE2-1,qAR,VK4RBT-1:37C
PU2LYJ-15>BEACON,PY2HY-15,WIDE2*,qAO,PY2PE-1:DIGI SUMARE SP
WB5GCL-1>APMI06,BTR*,WIDE2-1,qAR,W5MCC-1:@290356z3003.35N/09038.5 at W,PHG5560/ 
www.gulfcoastlink.com
KC1SPC>IDENT,qAR,W1AW:Winlink P2P
KI0AU-1>APMI06,W0JRT-3,CARROL,WA0SDO-10,WIDE2*,qAS,KA0GFC-1: <UI>:
DISABL>ID,qAR,K0SUN-3:Network Node
VA7VRO>BEACON,qAO,AF4PM-2:View Royal Fire Hall
IZ3QBN-B>APDG02,TCPIP*,qAC,IZ3QBN-BS:!441216.80ND12332.40E&RNG0001/A=000010 
440 Voice 435.95000MHz +0.0000MHz
WX8OH-7>ID,qAR,KB8UVN-7:Network node (WLOH)
KJ4VCX-7>SR5V1W,WIDE1-1,WIDE2-1,qAR,W5NGU-3:4P4T4X4\`|O$l >/]"5S}=
KJ4VCX-7>SR5V1W,W5NGU-3*,WIDE2-1,qAR,KS5S:[ binary data ]
KJ4VCX-7>SR5V1W,W5NGU-3*,WIDE2-1,qAR,W5DXM-1:4P
KI6SZ-2>UIDIGI,qAR,KA0AZS:UIDIGI 1.9
PI1LAP-7>ID,qAO,PI1ZLD-2:PI1LAP-7 - PI8LAP - JO11VN
KC0QNA-1>APMI04,WIDE1-1,qAR,NX0P:KC0QNA-1 APRS, GREEN ISLE, MN
VK1KW>ID,VK1RGI-1,qAO,VK1MA-1:VK1KW.AMPR.ORG 44.136.3.92 [QF44MT] 
Charnwood AUS Digi=VK1KW-2 BBS=VK1KW-6 147.575 1200bd
VR2WUK>APDW14,TCPIP*,qAC,T2TAIPEI:https://github.com/0x9900/igate_telem
K5WH-4>ID,WIDE,qAR,KC5TT-10:K5WH-4/R MARATH-4/D K5WH-1/B
IR3UJH-15>APRS,WIDE1-1,WIDE2-2,qAR,IR3BT:IT-DMR - DIGIPEATER APRS - 
Bolzano (BZ)
OE8NDR-11>APMI06,TCPIP*,qAS,OE8NDR:@Greetings from Fritz-OE8NDR
CALICO>ID,WIDE1-1,qAR,KG6PJG-10:CALICO ID:KO6BOB-10, WIDE1/2, Calico, CA 
Email: ko6bob at gmail.com
VE7CRP>BEACON,qAO,AF4PM-2:VE7CRP-7, K-NET NODE STACK ACCESS TO 440.125 
VIA VE7CRP-6
VE7CRP-7>ID,qAO,AF4PM-2:Network Node (569CRP)
KB7OKE>BEACON,qAR,W7VW-1:KB7OKE
NE4SC-12>ID,WIDE2-2,qAR,KW4BET-3:NE4SC-12/R NE4SC-1/B
KM6RFB-N>APDG04,TCPIP*,qAC,KM6RFB-NS:!3854.14ND121282400.00W&/A=000000440 
MMDVM Voice 446.52500MHz +0.0000MHz, KM6RFB_Pi-Star_ND
ON7DS>APMI06,TCPIP*,qAC,T2BELGIUM:@290403z<5114.16N/0424.24E>\L ON9BD 
LightShip Westhinder 3
KA0GFC-3>APN391,WIDE2-2,qAS,KA0GFC-1: <UI>:
KM6FDI-B>APDG02,TCPIP*,qAC,KM6FDI-BS:!31320200.00ND12153.16W&RNG0001/A=000010 
440 Voice 432.10000MHz +0.0000MHz
SR8NWF>UIDIGI,qAR,SP8JCF:UIDIGI 1.9

To be clear, can someone reassure me that the UIDIGI packets like the 
last one are indeed incorrectly formatted, i.e. there should be SOME 
type of APRS Data Type Identifier after the "SP8JCF:", probably a '>' ?  
The first 6 packets in the list above all look illegal because they're 
missing a DTI of '>'.

Code is here, if you ever find yourself needing an APRS parser in Java:  
https://github.com/ab0oo/javAPRSlib


de AB0OO
John Gorkos


-------------- next part --------------
A non-text attachment was scrubbed...
Name: OpenPGP_0xA4025CE04AE176ED_and_old_rev.asc
Type: application/pgp-keys
Size: 2346 bytes
Desc: OpenPGP public key
URL: <http://lists.tapr.org/pipermail/aprssig_lists.tapr.org/attachments/20230728/0add24e9/attachment.asc>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: OpenPGP_signature
Type: application/pgp-signature
Size: 236 bytes
Desc: OpenPGP digital signature
URL: <http://lists.tapr.org/pipermail/aprssig_lists.tapr.org/attachments/20230728/0add24e9/attachment.sig>