hcid.conf
HCID.CONF(5) System management commands HCID.CONF(5)
NAME
/etc/bluetooth/hcid.conf - Configuration file for the hcid Bluetooth
HCI daemon
DESCRIPTION
/etc/bluetooth/hcid.conf contains all the options needed by the Blue-
tooth Host Controller Interface daemon.
It consists of sections and parameters. A section begins with the name
of the section followed by optional specifiers and the parameters
inside curly brackets. Sections contain parameters of the form:
name value1, value2 ... ;
Any character after a hash (’#’) character is ignored until newline.
Whitespace is also ignored.
The valid section names for hcid.conf are, at the moment:
options
contains generic options for hcid and the pairing policy.
device contains lower-level options for the hci devices connected to
the computer.
OPTIONS SECTION
The following parameters may be present in an option section:
autoinit yes|no
Automatically initialize newly connected devices. The default
is no.
pairing none|multi|once
none means that pairing is disabled. multi allows pairing with
already paired devices. once allows pairing once and denies
successive attempts. The default hcid configuration is shipped
with multi enabled
pin_helper "file"
The path to the PIN helper application. The default is
"/bin/bluepin". The following output is expected from the PIN
helper:
PIN:12345678
Or, when no PIN is available:
ERR
security none|auto|user
none means the security manager is disabled. auto uses local
PIN for incoming connections. user always asks the user for a
PIN.
DEVICE SECTION
Parameters within a device section with no specifier, the default
device section, will be applied to all devices and device sections
where these are unspecified. The following optional device specifiers
are supported:
nn:nn:nn:nn:nn:nn
Parameters specified within this section will be applied to the
device with this device bluetooth address. All other parameters
are applied from the default section.
hcin Parameters specified within this section will be applied to
the device with this device interface, unless that device is
matched by a device address section. All other parameters are
applied from the default section.
Note: Most of the options supported in the device section are
described to some extent in the bluetooth specification version 1.2
Vol2, Part E section 6. Please refer to it for technical details.
The following parameters may be present in a device section:
name "name"
The device name. %d inserts the device id. %h inserts the host
name.
auth enable|disable
Enables or disables authentication between local and remote
devices when they connect.
Authentication is done following a challenge-response mechanism
described in the Bluetooth Specification 1.2 volume 2 part C
section 4.2, and uses the link key generated during pairing as
the shared secret.
encrypt enable|disable
Enable or disable link encryption. Should be set to enable in
most cases, unless one of the devices does not support encryp-
tion for some reason.
Encryption can only occur on authenticated connections, as a
shared secret key is necessary for encryption to work. The
detailed encryption mechanism is described in the bluetooth
specification as mentioned above.
class 0xSSDDdd (three bytes)
The Bluetooth Device Class is described in the Bluetooth
Specification section 1.2 ("Assigned Numbers - Bluetooth Base-
band").
The default shipped with hcid is 0x000100 which simply stands
for "Computer".
The Bluetooth device class is a high-level description of the
bluetooth device, composed of three bytes: the "Major Service
Class" (byte "SS" above), the "Major Device Class" (byte "DD"
above) and the "Minor Device Class" (byte "dd" above). These
classes describe the high-level capabilities of the device,
such as "Networking Device", "Computer", etc. This information
is often used by clients who are looking for a certain type of
service around them.
Where it becomes tricky is that another type of mechanism for
service discovery exists: "SDP", as in "Service Discovery Pro-
tocol".
In practice, most Bluetooth clients scan their surroundings in
two successive steps: they first look for all bluetooth devices
around them and find out their "class". You can do this on
Linux with the hcitool scan command. Then, they use SDP in
order to check if a device in a given class offers the type of
service that they want.
This means that the hcid.conf "class" parameter needs to be set
up properly if particular services are running on the host,
such as "PAN", or "OBEX Obect Push", etc: in general a device
looking for a service such as "Network Access Point" will only
scan for this service on devices containing "Networking" in
their major service class.
Major service class byte allocation (from LSB to MSB):
Bit 1: Positioning (Location identification)
Bit 2: Networking (LAN, Ad hoc, ...)
Bit 3: Rendering (Printing, Speaker, ...)
Bit 4: Capturing (Scanner, Microphone, ...)
Bit 5: Object Transfer (v-Inbox, v-Folder, ...)
Bit 6: Audio (Speaker, Microphone, Headset service, ...)
Bit 7: Telephony (Cordless telephony, Modem, Headset service,
...)
Bit 8: Information (WEB-server, WAP-server, ...)
Example: class 0x02hhhh : the device offers networking service
Major device class allocation:
0x00: Miscellaneous
0x01: Computer (desktop,notebook, PDA, organizers, .... )
0x02: Phone (cellular, cordless, payphone, modem, ...)
0x03: LAN /Network Access point
0x04: Audio/Video (headset,speaker,stereo, video display,
vcr.....
0x05: Peripheral (mouse, joystick, keyboards, ..... )
0x06: Imaging (printing, scanner, camera, display, ...)
Other values are not defined (refer to the Bluetooth specifica-
tion for more details
Minor device class allocation: the meaning of this byte depends
on the major class allocation, please refer to the Bluetooth
specifications for more details).
Example: if PAND runs on your server, you need to set up at
least class 0x020100, which stands for "Service Class: Network-
ing" and "Device Class: Computer, Uncategorized".
iscan enable|disable
pscan enable|disable
Bluetooth devices discover and connect to each other through
the use of two special Bluetooth channels, the Inquiry and Page
channels (described in the Bluetooth Spec Volume 1, Part A,
Section 3.3.3, page 35). These two options enable the channels
on the bluetooth device.
iscan enable: makes the bluetooth device "discoverable" by
enabling it to answer "inquiries" from other nearby bluetooth
devices.
pscan enable: makes the bluetooth device "connectable to" by
enabling the use of the "page scan" channel.
lm none|accept,master
none means no specific policy. accept means always accept
incoming connections. master means become master on incoming
connections and deny role switch on outgoing connections.
lp none|rswitch,hold,sniff,park
none means no specific policy. rswitch means allow role switch.
hold means allow hold mode. sniff means allow sniff mode. park
means allow park mode. Several options can be combined.
This option determines the various operational modes that are
allowed for this device when it participates to a piconet. Nor-
mally hold and sniff should be enabled for standard opera-
tions.
hold: this mode is related to synchronous communications (SCO
voice channel for example).
sniff: when in this mode, a device is only present on the
piconet during determined slots of time, allowing it to do
other things when it is "absent", for example to scan for other
bluetooth devices.
park: this is a mode where the device is put on standby on the
piconet, for power-saving purposes for example.
rswitch: this is a mode that enables role-switch (master <->
slave) between two devices in a piconet. It is not clear
whether this needs to be enabled in order to make the "lm mas-
ter" setting work properly or not.
pkt_type DH1,DM1,HV1, etc.
This fairly obscure option determines the packet types that the
bluetooth device will send or accept. This is a very low-level
option that should probably not be changed for normal use. You
do not need to specify defaults.
You can check the Bluetooth specification version 1.2 Volume 2,
Part B section 6 for more details about this.
FILES
/etc/bluetooth/hcid.conf
Default location of the global configuration file.
AUTHOR
This manual page was written by Edouard Lafargue, Fredrik Noring and
Maxim Krasnyansky.
hcid.conf - HCI daemon March 2004 HCID.CONF(5)
