BACnet/IP analyzer/detector for Bro
=====================================

This analyzer can parse and detect the BACnet/IP protocol as defined by
ANSI/ASHRAE 135-2016, Appendix J.


Installation
------------

    ./configure --bro-dist=<path>
    make
    make install


Usage
-----

bro [commands, options, etc.] Heller::bacnet


Behavior / Log file
-------------------

A bacnet.log file should be created if you have any BACnet/IP packets on the wire or in the
capture you've fed into Zeek / Bro.  Below is a list of the fields and a description of their
contents (also in the field_descr file):

Field Name              Type        Description
ts                      time        Standard Zeek timestamp
uid                     string      Standard Zek UID for cross referencing connections
id.orig_h               addr        Standard Zeek origin IP address
id.org_p                port        Standard Zeek origin IP port
id.resp_h               addr        Standard Zeek response IP address
id.resp_p               port        Standard Zeek response IP port
BVLL_pkts               count       The number of packets in a connection that have BACnet Virtual Link Layer (BVLL) content (this should be a count of all BACnet/IP packets)
NPDU_pkts               count       The number of BACnet/IP packets in a connection that contain Network Protocol Data Units (NPDUs)
APDU_pkts               count       The number of BACnet/IP packets in a connection that contain Application Protocol Data Units (APDUs)
DST                     string      A summary of the destination networks and addresses seen in the connection that are non-IP based
SRC                     string      A summary of the source networks and addresses seen in the connection that are non-IP based
BVLC_Result             count       The number of BVLL BVLC-Result packets seen on the connection
Write_BDT               count       The number of BVLL Write-Broadcast-Distribution-Table packets seen on the connection
Read_BDT                count       The number of BVLL Read-Broadcast-Distribution-Table packets seen on the connection
Read_BDT_ACK            count       The number of BVLL Read-Broadcast-Distribution-Table-ACK packets seen on the connection
FWD_NPDU                count       The number of BVLL Forwarded-NPDU packets seen on the connection
RFD                     count       The number of BVLL Register-Foreign-Device packets seen on the connection
Read_FDT                count       The number of BVLL Read-Foreign-Device-Table packets seen on the connection
Read_FDT_ACK            count       The number of BVLL Read-Foreign-Device-Table-Ack packets seen on the connection
Del_FDT_Entry           count       The number of BVLL Delete-Foreign-Device-Table-Entry packets seen on the connection
DBN                     count       The number of BVLL Distribute-Broadcast-To-Network packets seen on the connection
Orig_Uni                count       The number of BVLL Original-Unicast-NPDU packets seen on the connection
Orig_Broad              count       The number of BVLL Original-Broadcast-NPDU packets seen on the connection
Secure_BVLL             count       The number of BVLL Secure-BVLL packets seen on the connection
MT_Who_Is_Router        count       The number of NPDU Who-Is-Router-To-Network packets seen on the connection
MT_I_Am_Router          count       The number of NPDU I-Am-Router-To-Network packets seen on the connection
MT_Could_Be_Router      count       The number of NPDU I-Could-Be-Router-To-Network packets seen on the connection
MT_Reject_Msg           count       The number of NPDU Reject-Message-To-Network packets seen on the connection
MT_Router_Busy          count       The number of NPDU Router-Busy-To-Network packets seen on the connection
MT_Router_Avail         count       The number of NPDU Router-Available-To-Network packets seen on the connection
MT_Init_Route_Tbl       count       The number of NPDU Initialize-Routing-Table packets seen on the connection
MT_Init_Route_TblACK    count       The number of NPDU Initialize-Routing-Table-Ack packets seen on the connection
MT_Establish_Conn       count       The number of NPDU Establish-Connection-To-Network packets seen on the connection
MT_Break_Conn           count       The number of NPDU Disconnect-Connection-To-Network packets seen on the connection
MT_Challenge_Req        count       The number of NPDU Challenge-Request packets seen on the connection
MT_Security_Payload     count       The number of NPDU Security-Payload packets seen on the connection
MT_ Security_Resp       count       The number of NPDU Security-Response packets seen on the connection
MT_Req_Key_Update       count       The number of NPDU Request-Key-Update packets seen on the connection
MT_Update_Key_Set       count       The number of NPDU Update-Key-Set packets seen on the connection
MT_Update_Distr_Key     count       The number of NPDU Update-Distribution-Key packets seen on the connection
MT_Req_Master_Key       count       The number of NPDU Request-Master-Key packets seen on the connection
MT_Set_Master_Key       count       The number of NPDU Set-Master-Key packets seen on the connection
MT_What_Is_Net_Num      count       The number of NPDU What-Is-Network-Number packets seen on the connection
MT_Net_Num_Is           count       The number of NPDU Network-Number-Is packets seen on the connection
MT_Reserved             count       The number of NPDU packets with message types reserved for use by ASHRAE seen on the connection
MT_Vendor_Custom        count       The number of NPDU packets with vendor proprietary message types seen on the connection
Priority_Normal         count       The number of normal priority NPDU messages
Priority_Urgent         count       The number of urgent priority NPDU messages
Priority_Critical       count       The number of critical equipment priority NPDU messages
Priority_Life           count       The number of life safety priority NPDU messages
APDU_Total_Segments     count       The total number of segmenets seen on a connection
APDU_Conf_Req           count       The number of confirmed-request-pdus seen on a connection
APDU_Conf_Req_Segs      count       The number of segmenets for all confirmed-request-pdus seen on a connection
APDU_Unconf_Req         count       The number of unconfirmed-request-pdus seen on a connection
APDU_SimpleACK          count       The number of simple-ack-pdus seen on a connection
APDU_ComplexACK         count       The number of complex-ack-pdus seen on a connection
APDU_ComplexACK_Segs    count       The number of segmenets for all complex-ack-pdus seen on a connection
APDU_SegmentACK         count       The number of segment-ack-pdus seen on a connection
APDU_Error              count       The number of error-pdus seen on a connection
APDU_Reject             count       The number of reject-pdus seen on a connection
APDU_Abort              count       The number of abort-pdus seen on a connection


Acknowledgements
----------------

Thanks to Tri Quach, Palumbo Mauro, and Justin Azoff for your help with understanding
Zeek/Bro.