This repo contains FFI bindings for the BACnet stack.
The folder bacnet-stack-1.0.0 contains the full source code, copied verbatim from sourceforge.
The source code under [/omnioiot/bacnet-sys/tree/master/bacnet-stack-1.0.0] uses a GPLv2 with exception license, meaning "that any changes to the core code that are distributed must be made available in accordance with section (3) of the GNU General Public License".
The surrounding Rust code is licensed under the same conditions, ie GPLv2 with the same exception.
The exception is as follows:
"As a special exception, if other files instantiate
templates or use macros or inline functions from
this file, or you compile this file and link it
with other works to produce a work based on this file,
this file does not by itself cause the resulting work
to be covered by the GNU General Public License.
However the source code for this file must still be
made available in accordance with section (3) of the
GNU General Public License."
Link: https://sourceforge.net/projects/bacnet/files/bacnet-stack/bacnet-stack-1.0.0/