The
btpand daemon handles Bluetooth Personal Area Networking services in the system. It can operate in client mode as a Personal Area Networking User (PANU) or in server mode as Network Access Point (NAP), Group ad-hoc Network (GN) or PANU host.
btpand connects to the system via a
tap(4) virtual Ethernet device and forwards Ethernet packets to remote Bluetooth devices using the Bluetooth Network Encapsulation Protocol (BNEP).
The PANU client is the device that uses either the NAP or GN service, or can talk directly to a PANU host in a crossover cable fashion.
A GN host forwards Ethernet packets to each of the connected PAN users as needed but does not provide access to any additional networks.
The NAP service provides some of the features of an Ethernet bridge, with the NAP host forwarding Ethernet packets between each of the connected PAN users, and a different network media.
Note, the only differences between NAP and GN services as implemented by
btpand are in the SDP service record. The bridging of packets by the NAP must be configured separately with
brconfig(4).
The options are as follows:
-a address
In client mode, address of remote server. May be given as BDADDR or name, in which case
btpand will attempt to resolve the address via the
bt_gethostbyname(3) call.
-c path
In server mode, specify
path to the
sdpd(8) control socket. The default path is
/var/run/sdp.
-d device
Restrict connections to the local
device. May be given as BDADDR or name, in which case
btpand will attempt to resolve the address via the
bt_devaddr(3) call.
btpand will set the
tap(4) interface physical address to the BDADDR of the Bluetooth radio.
-i ifname
btpand uses the
tap(4) driver to create a new network interface for use. Use this option to select a specific
tap(4) device interface which must already be created.
-l limit
In server mode, limit the number of simultaneous connections. The default limit is 7 for NAP and GN servers, and 1 for a PANU server.
-m mode
Set L2CAP connection link mode. Supported modes are:
auth
require devices to be paired.
encrypt
auth, plus enable encryption.
secure
encryption, plus change of link key.
-p psm
Use an alternative L2CAP Protocol/Service Multiplexer (PSM) for server mode or client mode (when not using Service Discovery). The default PSM for BNEP is 15 (0x000f).
-s service
Name of
service to provide or connect to, the following services are recognised:
NAP
Network Access Point.
PANU
Personal Area Networking User.
-S service
As per -s except that btpand will not use SDP services for connection setup.
When providing networking services, the Bluetooth PAN profile says that the ‘Class of Device' property of the bluetooth controller SHALL include Networking capability (set bit 0x020000). See
btconfig(8) for details.
After
btpand has set up the client or server connection and opened the
tap(4) interface, it will create a pid file and detach.