Updated: 2022/Sep/29
Please read Privacy Policy. It's for your privacy.
BLUETOOTH(9) Kernel Developer's Manual BLUETOOTH(9)
NAME
BLUETOOTH - Bluetooth Device/Protocol API
SYNOPSIS
#include <netbt/bluetooth.h>
#include <netbt/hci.h>
#include <netbt/l2cap.h>
#include <netbt/rfcomm.h>
struct hci_unit *
hci_attach(const struct hci_if *hci_if, device_t dev, uint16_t flags);
void
hci_detach(struct hci_unit *unit);
void
hci_input_event(struct hci_unit *unit, struct mbuf *m);
void
hci_input_acl(struct hci_unit *unit, struct mbuf *m);
void
hci_input_sco(struct hci_unit *unit, struct mbuf *m);
int
btproto_attach(btproto_handle *, const struct btproto *proto, void *ref);
int
btproto_bind(btproto_handle, struct sockaddr_bt *addr);
int
btproto_sockaddr(btproto_handle, struct sockaddr_bt *addr);
int
btproto_connect(btproto_handle, struct sockaddr_bt *addr);
int
btproto_peeraddr(btproto_handle, struct sockaddr_bt *addr);
int
btproto_disconnect(btproto_handle, int linger);
int
btproto_detach(btproto_handle *);
int
btproto_listen(btproto_handle);
int
btproto_send(btproto_handle, struct mbuf *mbuf);
int
btproto_rcvd(btproto_handle, size_t space);
int
btproto_setopt(btproto_handle, int optarg, void *arg);
int
btproto_getopt(btproto_handle, int optarg, void *arg);
DESCRIPTION
The Bluetooth Protocol Stack provides socket based access to Bluetooth
Devices. This document describes device driver access to the stack from
below, and also the general Bluetooth Protocol/Service API for layering
above existing Bluetooth Protocols.
DATA TYPES
Device drivers attaching to the Bluetooth Protocol Stack should pass a
pointer to a struct hci_if defined in <netbt/hci.h> containing the driver
information as follows:
struct hci_if {
int (*enable)(device_t);
void (*disable)(device_t);
void (*output_cmd)(device_t, struct mbuf *);
void (*output_acl)(device_t, struct mbuf *);
void (*output_sco)(device_t, struct mbuf *);
void (*get_stats)(device_t, struct bt_stats *, int);
int ipl;
};
Statistics counters should be updated by the device after packets have
been transmitted or received, or when errors occur.
struct bt_stats {
uint32_t err_tx;
uint32_t err_rx;
uint32_t cmd_tx;
uint32_t evt_rx;
uint32_t acl_tx;
uint32_t acl_rx;
uint32_t sco_tx;
uint32_t sco_rx;
uint32_t byte_tx;
uint32_t byte_rx;
};
Bluetooth Protocol layers attaching above the Bluetooth Protocol Stack
will make use of the struct btproto data type, which is defined in
<netbt/bluetooth.h> and contains the following function callbacks which
should be initialized by the protocol layer before attaching to the
protocol which it uses:
struct btproto {
void (*connecting)(void *);
void (*connected)(void *);
void (*disconnected)(void *, int);
void *(*newconn)(void *, struct sockaddr_bt *, struct sockaddr_bt *);
void (*complete)(void *, int);
void (*linkmode)(void *, int);
void (*input)(void *, struct mbuf *);
};
FUNCTIONS
The following functions are related to the Bluetooth Device API.
hci_attach(hci_if, dev)
Attach Bluetooth HCI device dev to the protocol stack in the manner
described by hci_if. Driver quirks may be registered by passing
the corresponding BTF_xxxx flag in the flags argument.
hci_attach() will return a struct hci_unit handle to be passed to
the protocol stack in other calls.
hci_detach(unit)
Detach Bluetooth HCI unit from the device.
hci_input_event(unit, mbuf)
This function should be called by the device when it has an event
packet to present to the protocol stack. It may be called from an
interrupt routine at the ipl value given in the hci_if descriptor.
hci_input_acl(unit, mbuf)
This function should be called by the device when it has an ACL
data packet to present to the protocol stack. It may be called
from an interrupt routine at the ipl value given in the hci_if
descriptor.
hci_input_sco(unit, mbuf)
This function should be called by the device when it has an SCO
data packet to present to the protocol stack. It may be called
from an interrupt routine at the ipl value given in the hci_if
descriptor.
(*enable)(dev)
This will be called when the protocol stack wishes to enable the
device.
(*disable)(dev)
This will be called when the protocol stack wishes to disable the
device.
(*output_cmd)(dev, mbuf)
Will be called to output command packets on the device. The device
is responsible for arbitrating access to the output queue, and
output commands should be sent asynchronously. The device owns the
mbuf and should release it when sent.
(*output_acl)(dev, mbuf)
Will be called to output ACL data packets on the device. The
device is responsible for arbitrating access to the output queue,
and ACL data packets should be sent asynchronously. The device
owns the mbuf and should release it when sent.
(*output_sco)(dev, mbuf)
Will be called to output SCO data packets on the device. The
device is responsible for arbitrating access to the output queue,
and SCO data packets should be sent asynchronously. When the SCO
data packet has been placed on the device and the mbuf is no longer
required, it should be returned to the Bluetooth protocol stack via
the hci_complete_sco() call.
(*get_stats)(dev, dest, flush)
Will be called when IO statistics are requested. The bt_stats
structure dest should be filled in, and if the flush argument is
true, statistics should be reset.
The following function definitions are related to the Bluetooth Protocol
API. Note that the "btproto" prefix is representative only, the protocol
being used will have a more specific prefix with prototypes being
declared in the appropriate <netbt/btproto.h> file.
btproto_attach(handle_ptr, proto, ref)
Allocate and initialize a new protocol object at the handle_ptr
address that should subsequently be passed into the other
functions. proto is a pointer to the btproto structure as
described above containing relevant callbacks, and ref is the
argument that will be supplied to those calls.
btproto_bind(handle, addr)
Set the local address of the protocol object described by handle to
addr.
btproto_sockaddr(handle, addr)
Copy the local address of the protocol object described by handle
into addr
btproto_connect(handle, addr)
Initiate a connection by the protocol object described by handle to
the remote device described by addr. This will result in a call to
either proto->connected() or proto->disconnected(), and optionally
proto->connecting() with the appropriate reference as given to
btproto_attach().
btproto_peeraddr(handle, addr)
Copy the remote address of the protocol object described by handle
into addr.
btproto_disconnect(handle, linger)
Schedule a disconnection by the protocol object described by
handle. This will result in a call to proto->disconnected() with
the appropriate reference when the connection is torn down. If
linger is zero, the disconnection will be initiated immediately and
any outstanding data may be lost.
btproto_detach(handle_ptr)
Detach the protocol object described by the value in the location
of handle_ptr, and free any related memory. The pointer in the
location is cleared.
btproto_listen(handle)
Use the protocol object described by handle as a listening post.
This will result in calls to the proto->newconn() function when
incoming connections are detected.
btproto_send(handle, mbuf)
Send data on the connection described by the protocol object.
btproto_rcvd(handle, space)
Indicate to the protocol that space is now available in the input
buffers so that flow control may be deasserted. This should also
be called to indicate initial buffer space. Note that space is an
absolute value.
btproto_setopt(handle, optarg, arg)
Set options on the protocol object described by handle.
btproto_getopt(handle, optarg, arg)
Get options for the protocol object described by handle.
(*connecting)(ref)
This function will be called when the protocol receives information
that the connection described by ref is pending.
(*connected)(ref)
This function will be called when the connection described by ref
is successful and indicates that data may now be sent.
(*disconnected)(ref, error)
This function will be called when the connection described by ref
is disconnected.
*(*newconn)(ref, laddr, raddr)
This function will be called when the protocol receives a new
incoming connection on the local device described by laddr from the
remote device described by raddr. The protocol should decide if it
wishes to accept the connection and should attach and return a new
instance of the relevant protocol handle or NULL.
(*complete)(ref, count)
This function will be called when the protocol has completed
sending data. Complete will usually mean that the data has
successfully left the device though for guaranteed protocols it can
mean that the data has arrived at the other end and been
acknowledged, and that count amount of data can be removed from the
socket buffer. The units of the count value will be dependent on
the protocol being used (e.g. RFCOMM is bytes, but L2CAP is
packets)
(*linkmode)(ref, mode)
This function will be called for established connections, when the
link mode of the baseband link has changed. mode is the new mode.
(*input)(ref, mbuf)
This function is called to supply new data on the connection
described by ref.
CODE REFERENCES
The Bluetooth Protocol Stack is contained in the sys/netbt directory.
The Bluetooth Device API as described above is contained in the
sys/netbt/hci_unit.c file.
For examples of the Bluetooth Protocol API see the interaction between
the L2CAP upper layer in sys/netbt/l2cap_upper.c and either the L2CAP
socket layer in sys/netbt/l2cap_socket.c or the bthidev(4) pseudo-device
in sys/dev/bluetooth/bthidev.c.
Also, the RFCOMM upper layer in sys/netbt/rfcomm_upper.c and the RFCOMM
socket layer in sys/netbt/rfcomm_socket.c.
SEE ALSO
bluetooth(4), bt3c(4), bthidev(4), ubt(4)
HISTORY
This Bluetooth Protocol Stack was written for NetBSD 4.0 by Iain Hibbert,
under the sponsorship of Itronix, Inc.
NetBSD 10.99 November 20, 2007 NetBSD 10.99