btsnoop_net exposes Bluetooth snoop logs over a local TCP socket which enables real-time debugging of HCI data with hcidump.
This feature is enabled by enabling “Enable Bluetooth HCI snoop log” in the Developer options and setting BT_NET_DEBUG flag to TRUE in the btsnoop_net.cc. Once it has been enabled and the stack restarted, the stack will listen for incoming TCP connections on port 8872.
To use this feature with btmon on a Linux host, you can run:
$ adb forward tcp:8872 tcp:8872 $ nc localhost 8872 | btmon -P -r /dev/stdin