NAME
bt_gethostbyname
,
bt_gethostbyaddr
,
bt_gethostent
,
bt_sethostent
,
bt_endhostent
,
bt_getprotobyname
,
bt_getprotobynumber
,
bt_getprotoent
,
bt_setprotoent
,
bt_endprotoent
, bt_aton
,
bt_ntoa
, bt_devaddr
,
bt_devname
, bt_devinfo
,
bt_devenum
, bt_devopen
,
bt_devclose
, bt_devsend
,
bt_devrecv
, bt_devreq
,
bt_devfilter
,
bt_devfilter_pkt_set
,
bt_devfilter_pkt_clr
,
bt_devfilter_pkt_tst
,
bt_devfilter_evt_set
,
bt_devfilter_evt_clr
,
bt_devfilter_evt_tst
,
bt_devinquiry
,
bt_devremote_name
,
bt_devremote_name_gen
,
bdaddr_same
, bdaddr_any
,
bdaddr_copy
—
Bluetooth routines
LIBRARY
library “libbluetooth”
SYNOPSIS
#include
<bluetooth.h>
struct hostent *
bt_gethostbyname
(const
char *name);
struct hostent *
bt_gethostbyaddr
(const
char *addr, int
len, int type);
struct hostent *
bt_gethostent
(void);
void
bt_sethostent
(int
stayopen);
void
bt_endhostent
(void);
struct protoent *
bt_getprotobyname
(const
char *name);
struct protoent *
bt_getprotobynumber
(int
proto);
struct protoent *
bt_getprotoent
(void);
void
bt_setprotoent
(int
stayopen);
void
bt_endprotoent
(void);
int
bt_aton
(const
char *str, bdaddr_t
*ba);
const char *
bt_ntoa
(const
bdaddr_t *ba, char
*str);
int
bt_devaddr
(const
char *devname, bdaddr_t
*addr);
int
bt_devname
(char
*devname, const bdaddr_t
*addr);
int
(bt_devenum_cb_t)
(int
s, struct bt_devinfo
const *di, void
*arg);
int
bt_devinfo
(struct
bt_devinfo *di);
int
bt_devenum
(bt_devenum_cb_t
*cb, void
*arg);
int
bt_devopen
(char
const *devname);
int
bt_devclose
(int
s);
int
bt_devsend
(int
s, uint16_t opcode,
void *param,
size_t plen);
ssize_t
bt_devrecv
(int
s, void *buf,
size_t size,
time_t to);
int
bt_devreq
(int
s, struct bt_devreq
*r, time_t to);
int
bt_devfilter
(int
s, struct bt_devfilter
const *new, struct
bt_devfilter *old);
void
bt_devfilter_pkt_set
(struct
bt_devfilter *filter,
uint8_t type);
void
bt_devfilter_pkt_clt
(struct
bt_devfilter *filter,
uint8_t type);
int
bt_devfilter_pkt_tst
(struct
bt_devfilter const *filter,
uint8_t type);
void
bt_devfilter_evt_set
(struct
bt_devfilter *filter,
uint8_t event);
void
bt_devfilter_evt_clt
(struct
bt_devfilter *filter,
uint8_t event);
int
bt_devfilter_evt_tst
(struct
bt_devfilter const *filter,
uint8_t event);
int
bt_devinquiry
(char
const *devname, time_t
length, int
num_rsp, struct
bt_devinquiry **ii);
char *
bt_devremote_name
(char
const *devname, const
bdaddr_t *remote, time_t
to, uint16_t
clk_off, uint8_t
ps_rep_mode, uint8_t
ps_mode);
char *
bt_devremote_name_gen
(char
const *btooth_devname,
const bdaddr_t
*remote);
int
bdaddr_same
(const
bdaddr_t *a, const
bdaddr_t *b);
int
bdaddr_any
(const
bdaddr_t *a);
int
bdaddr_copy
(const
bdaddr_t *dst, const
bdaddr_t *src);
DESCRIPTION
Thebt_gethostent
(),
bt_gethostbyname
() and
bt_gethostbyaddr
() functions each return a pointer to
an object with the hostent structure describing a
Bluetooth host referenced by name or by address, respectively.
The name argument
passed to
bt_gethostbyname
()
should point to a NUL
-terminated hostname. The
addr argument passed to
bt_gethostbyaddr
()
should point to an address which is len bytes long, in
binary form (i.e., not a Bluetooth BD_ADDR in human readable ASCII form).
The type argument specifies the address family of this
address and must be set to AF_BLUETOOTH
.
The structure returned contains the information obtained from a line in /etc/bluetooth/hosts file.
The
bt_sethostent
()
function controls whether /etc/bluetooth/hosts file
should stay open after each call to
bt_gethostbyname
() or
bt_gethostbyaddr
(). If the
stayopen flag is non-zero, the file will not be
closed.
The
bt_endhostent
()
function closes the /etc/bluetooth/hosts file.
The
bt_getprotoent
(),
bt_getprotobyname
() and
bt_getprotobynumber
() functions each return a
pointer to an object with the protoent structure
describing a Bluetooth Protocol Service Multiplexor referenced by name or
number, respectively.
The name argument
passed to
bt_getprotobyname
()
should point to a NUL
-terminated Bluetooth Protocol
Service Multiplexor name. The proto argument passed to
bt_getprotobynumber
()
should have numeric value of the desired Bluetooth Protocol Service
Multiplexor.
The structure returned contains the information obtained from a line in /etc/bluetooth/protocols file.
The
bt_setprotoent
()
function controls whether /etc/bluetooth/protocols
file should stay open after each call to
bt_getprotobyname
() or
bt_getprotobynumber
(). If the
stayopen flag is non-zero, the file will not be
closed.
The
bt_endprotoent
()
function closes the /etc/bluetooth/protocols
file.
The
bt_aton
()
routine interprets the specified character string as a Bluetooth address,
placing the address into the structure provided. It returns 1 if the string
was successfully interpreted, or 0 if the string is invalid.
The routine
bt_ntoa
()
takes a Bluetooth address and places an ASCII string representing the
address into the buffer provided. It is up to the caller to ensure that
provided buffer has enough space. If no buffer was provided then internal
static buffer will be used.
The
bt_devaddr
()
function interprets the specified devname string as
the address or device name of a Bluetooth device on the local system, and
places the device address in the provided bdaddr, if
any. The function returns 1 if the string was successfully interpreted, or 0
if the string did not match any local device. The
bt_devname
()
function takes a Bluetooth device address and copies the local device name
associated with that address into the buffer provided, if any. Caller must
ensure that provided buffer is at least
HCI_DEVNAME_SIZE
characters in size. The function
returns 1 when the device was found, otherwise 0.
The
bt_devinfo
()
function populates provided bt_devinfo structure with
the information about given Bluetooth device. The caller is expected to pass
Bluetooth device name in the devname field of the
passed bt_devinfo structure. The function returns 0
when successful, otherwise -1. The bt_devinfo
structure is defined as follows
struct bt_devinfo { char devname[HCI_DEVNAME_SIZE]; uint32_t state; bdaddr_t bdaddr; uint16_t _reserved0; uint8_t features[HCI_DEVFEATURES_SIZE]; /* buffer info */ uint16_t _reserved1; uint16_t cmd_free; uint16_t sco_size; uint16_t sco_pkts; uint16_t sco_free; uint16_t acl_size; uint16_t acl_pkts; uint16_t acl_free; /* stats */ uint32_t cmd_sent; uint32_t evnt_recv; uint32_t acl_recv; uint32_t acl_sent; uint32_t sco_recv; uint32_t sco_sent; uint32_t bytes_recv; uint32_t bytes_sent; /* misc/specific */ uint16_t link_policy_info; uint16_t packet_type_info; uint16_t role_switch_info; uint16_t debug; uint8_t _padding[20]; };
The
bt_devenum
()
function enumerates Bluetooth devices present in the system. For every
device found, the function will call provided cb
callback function which should be of bt_devenum_cb_t
type. The callback function is passed a HCI
socket
s, fully populated bt_devinfo
structure di and arg argument
provided to the bt_devenum
(). The callback function
can stop enumeration by returning a value that is greater than zero. The
function returns number of successfully enumerated devices, or -1 if an
error occurred.
The
bt_devopen
()
function opens a Bluetooth device with the given
devname and returns a connected and bound
HCI
socket handle. The function returns -1 if an
error has occurred.
The
bt_devclose
()
closes the passed HCI
socket handle
s, previously obtained with
bt_devopen(3).
The
bt_devsend
()
function sends a Bluetooth HCI
command with the
given opcode to the provided socket
s, previously obtained with
bt_devopen(3). The opcode parameter is
expected to be in the host byte order. The param and
plen parameters specify command parameters. The
bt_devsend
() function does not modify the
HCI
filter on the provided socket
s. The function returns 0 on success, or -1 if an
error occurred.
The
bt_devrecv
()
function receives one Bluetooth HCI
packet from the
socket s, previously obtained with
bt_devopen(3). The packet is placed into the provided buffer
buf of size size. The
to parameter specifies receive timeout in seconds.
Infinite timeout can be specified by passing negative value in the
to parameter. The bt_devrecv
()
function does not modify the HCI
filter on the
provided socket s. The function returns total number
of bytes received, or -1 if an error occurred.
The
bt_devreq
()
function makes a Bluetooth HCI
request to the socket
s, previously obtained with
bt_devopen(3). The function will send the specified command
and will wait for the specified event, or timeout to
seconds to occur. The bt_devreq structure is defined
as follows
struct bt_devreq { uint16_t opcode; uint8_t event; void *cparam; size_t clen; void *rparam; size_t rlen; };
The opcode field specifies
the command and is expected to be in the host byte order. The
cparam and clen fields specify
command parameters data and command parameters data size respectively. The
event field specifies which Bluetooth
HCI
event ID the function should wait for, otherwise
it should be set to zero. The HCI
Command Complete
and Command Status events are enabled by default. The
rparam and rlen parameters
specify buffer and buffer size respectively where return parameters should
be placed. The
bt_devreq
()
function temporarily modifies filter on the provided
HCI
socket s. The function
returns 0 on success, or -1 if an error occurred.
The
bt_devfilter
()
controls the local HCI
filter associated with the
socket s, previously obtained with
bt_devopen(3). Filtering can be done on packet types, i.e.
ACL
, SCO
or
HCI
, command and event packets, and, in addition, on
HCI
event IDs. Before applying the
new filter (if provided) the function will try to
obtain the current filter from the socket s and place
it into the old parameter (if provided). The function
returns 0 on success, or -1 if an error occurred.
The
bt_devfilter_pkt_set
(),
bt_devfilter_pkt_clr
()
and
bt_devfilter_pkt_tst
()
functions can be used to modify and test the HCI
filter filter. The type
parameter specifies HCI
packet type.
The
bt_devfilter_evt_set
(),
bt_devfilter_evt_clr
()
and
bt_devfilter_evt_tst
()
functions can be used to modify and test the HCI
event filter filter. The event
parameter specifies HCI
event ID.
The
bt_devinquiry
()
function performs Bluetooth inquiry. The devname
parameter specifies which local Bluetooth device should perform an inquiry.
If not specified, i.e. NULL
, then first available
device will be used. The length parameters specifies
the total length of an inquiry in seconds. If not specified, i.e. 0, default
value will be used. The num_rsp parameter specifies
the number of responses that can be received before the inquiry is halted.
If not specified, i.e. 0, default value will be used. The
ii parameter specifies where to place inquiry results.
On success, the function will return total number of inquiry results, will
allocate, using
calloc(3), buffer to store all the inquiry results and will return
pointer to the allocated buffer in the ii parameter.
It is up to the caller of the function to dispose of the buffer using
free(3) call. The function returns -1 if an error has occurred. The
bt_devinquiry structure is defined as follows
struct bt_devinquiry { bdaddr_t bdaddr; uint8_t pscan_rep_mode; uint8_t pscan_period_mode; uint8_t dev_class[3]; uint16_t clock_offset; int8_t rssi; uint8_t data[240]; };
The
bt_devremote_name
()
function performs Bluetooth Remote Name Request procedure to obtain the
user-friendly name of another Bluetooth unit. The
devname parameter specifies which local Bluetooth
device should perform the request. If not specified
(NULL
), the first available device is used. The
remote parameter specifies the Bluetooth BD_ADDR of
the remote device to query. The to parameter specifies
response timeout in seconds. If not specified (0), the default value is
taken from the net.bluetooth.hci.command_timeout
sysctl(8) value. The clk_off,
ps_rep_mode, and ps_mode
parameters specify Clock_Offset, Page_Scan_Repetition_Mode, and
Page_Scan_Mode fields of HCI_Remote_Name_Request respectively. On success,
the function returns a pointer to dynamically allocated NUL-terminated
string or NULL
if an error occurred. It is up to the
caller to release returned string using
free(3).
The
bt_devremote_name_gen
()
function is a shortcut to bt_devremote_name
() that
passes generic defaults for to,
clk_off, ps_rep_mode, and
ps_mode parameters.
The
bdaddr_same
(),
bdaddr_any
(),
and
bdaddr_copy
()
are handy shorthand Bluetooth address utility functions. The
bdaddr_same
() function will test if two provided
BD_ADDRs are the same. The bdaddr_any
() function
will test if provided BD_ADDR is ANY
BD_ADDR. The
bdaddr_copy
() function will copy provided
src BD_ADDR into provided dst
BD_ADDR.
FILES
- /etc/bluetooth/hosts
- /etc/bluetooth/protocols
EXAMPLES
Print out the hostname associated with a specific BD_ADDR:
const char *bdstr = "00:01:02:03:04:05"; bdaddr_t bd; struct hostent *hp; if (!bt_aton(bdstr, &bd)) errx(1, "can't parse BD_ADDR %s", bdstr); if ((hp = bt_gethostbyaddr((const char *)&bd, sizeof(bd), AF_BLUETOOTH)) == NULL) errx(1, "no name associated with %s", bdstr); printf("name associated with %s is %s\n", bdstr, hp->h_name);
DIAGNOSTICS
Error return status from bt_gethostent
(),
bt_gethostbyname
() and
bt_gethostbyaddr
() is indicated by return of a
NULL
pointer. The external integer
h_errno may then be checked to see whether this is a
temporary failure or an invalid or unknown host. The routine
herror(3) can be used to print an error message describing the
failure. If its argument string is
non-NULL
, it is printed, followed by a colon and a
space. The error message is printed with a trailing newline.
The variable h_errno can have the following values:
HOST_NOT_FOUND
- No such host is known.
NO_RECOVERY
- Some unexpected server failure was encountered. This is a non-recoverable error.
The bt_getprotoent
(),
bt_getprotobyname
() and
bt_getprotobynumber
() return
NULL
on EOF or error.
SEE ALSO
gethostbyaddr(3), gethostbyname(3), getprotobyname(3), getprotobynumber(3), herror(3), inet_aton(3), inet_ntoa(3), ng_hci(4)
CAVEAT
The
bt_gethostent
()
function reads the next line of
/etc/bluetooth/hosts, opening the file if
necessary.
The
bt_sethostent
()
function opens and/or rewinds the
/etc/bluetooth/hosts file.
The
bt_getprotoent
()
function reads the next line of
/etc/bluetooth/protocols, opening the file if
necessary.
The
bt_setprotoent
()
function opens and/or rewinds the
/etc/bluetooth/protocols file.
The
bt_devenum
()
function enumerates up to HCI_DEVMAX
Bluetooth
devices. During enumeration the bt_devenum
()
function uses the same HCI
socket. The function
guarantees that the socket, passed to the callback function, will be bound
and connected to the Bluetooth device being enumerated.
AUTHORS
Maksim Yevmenkin <m_evmenkin@yahoo.com>
BUGS
Some of those functions use static data storage; if the data is needed for future use, it should be copied before any subsequent calls overwrite it.