lib/libbluetooth/bluetooth.3

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.\" Copyright (c) 2003 Maksim Yevmenkin <m_evmenkin@yahoo.com>
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.\" $FreeBSD: src/lib/libbluetooth/bluetooth.3,v 1.7 2005/01/21 10:26:11 ru Exp $
.\"
.Dd October 25, 2011
.Dt BLUETOOTH 3
.Os
.Sh NAME
.Nm bt_gethostbyname ,
.Nm bt_gethostbyaddr ,
.Nm bt_gethostent ,
.Nm bt_sethostent ,
.Nm bt_endhostent ,
.Nm bt_getprotobyname ,
.Nm bt_getprotobynumber ,
.Nm bt_getprotoent ,
.Nm bt_setprotoent ,
.Nm bt_endprotoent ,
.Nm bt_aton ,
.Nm bt_ntoa
.Nd Bluetooth host lookup routines
.Sh LIBRARY
.Lb libbluetooth
.Sh SYNOPSIS
.In bluetooth.h
.Ft struct hostent *
.Fn bt_gethostbyname "const char *name"
.Ft struct hostent *
.Fn bt_gethostbyaddr "const char *addr" "int len" "int type"
.Ft struct hostent *
.Fn bt_gethostent void
.Ft void
.Fn bt_sethostent "int stayopen"
.Ft void
.Fn bt_endhostent void
.Ft struct protoent *
.Fn bt_getprotobyname "const char *name"
.Ft struct protoent *
.Fn bt_getprotobynumber "int proto"
.Ft struct protoent *
.Fn bt_getprotoent void
.Ft void
.Fn bt_setprotoent "int stayopen"
.Ft void
.Fn bt_endprotoent void
.Ft int
.Fn bt_aton "const char *str" "bdaddr_t *ba"
.Ft const char *
.Fn bt_ntoa "const bdaddr_t *ba" "char *str"
.Sh DESCRIPTION
The
.Fn bt_gethostent ,
.Fn bt_gethostbyname ,
and
.Fn bt_gethostbyaddr
functions each return a pointer to an object with the
.Vt hostent
structure describing a Bluetooth host
referenced by name or by address, respectively.
.Pp
The
.Fa name
argument passed to
.Fn bt_gethostbyname
should point to a
.Dv NUL Ns -terminated
hostname.
The
.Fa addr
argument passed to
.Fn bt_gethostbyaddr
should point to an address which is
.Fa len
bytes long,
in binary form
(i.e., not a Bluetooth BD_ADDR in human readable
.Tn ASCII
form).
The
.Fa type
argument specifies the address family of this address and must be set to
.Dv AF_BLUETOOTH .
.Pp
The structure returned contains the information obtained from a line in
.Pa /etc/bluetooth/hosts
file.
.Pp
The
.Fn bt_sethostent
function controls whether
.Pa /etc/bluetooth/hosts
file should stay open after each call to
.Fn bt_gethostbyname
or
.Fn bt_gethostbyaddr .
If the
.Fa stayopen
flag is non-zero, the file will not be closed.
.Pp
The
.Fn bt_endhostent
function closes the
.Pa /etc/bluetooth/hosts
file.
.Pp
The
.Fn bt_getprotoent ,
.Fn bt_getprotobyname ,
and
.Fn bt_getprotobynumber
functions each return a pointer to an object with the
.Vt protoent
structure describing a Bluetooth Protocol Service Multiplexer referenced
by name or number, respectively.
.Pp
The
.Fa name
argument passed to
.Fn bt_getprotobyname
should point to a
.Dv NUL Ns -terminated
Bluetooth Protocol Service Multiplexer name.
The
.Fa proto
argument passed to
.Fn bt_getprotobynumber
should have numeric value of the desired Bluetooth Protocol Service
Multiplexer.
.Pp
The structure returned contains the information obtained from a line in
.Pa /etc/bluetooth/protocols
file.
.Pp
The
.Fn bt_setprotoent
function controls whether
.Pa /etc/bluetooth/protocols
file should stay open after each call to
.Fn bt_getprotobyname
or
.Fn bt_getprotobynumber .
If the
.Fa stayopen
flag is non-zero, the file will not be closed.
.Pp
The
.Fn bt_endprotoent
function closes the
.Pa /etc/bluetooth/protocols
file.
.Pp
The
.Fn 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.
.Pp
The routine
.Fn bt_ntoa
takes a Bluetooth address and places an
.Tn 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 an internal static buffer will be used.
.Sh FILES
.Bl -tag -width ".Pa /etc/bluetooth/hosts" -compact
.It Pa /etc/bluetooth/hosts
.It Pa /etc/bluetooth/protocols
.El
.Sh EXAMPLES
Print out the hostname associated with a specific BD_ADDR:
.Bd -literal -offset indent
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\en", bdstr, hp->h_name);
.Ed
.Sh RETURN VALUES
Error return status from
.Fn bt_gethostent ,
.Fn bt_gethostbyname ,
and
.Fn bt_gethostbyaddr
is indicated by return of a
.Dv NULL
pointer.
The external integer
.Va h_errno
may then be checked to see whether this is a temporary failure
or an invalid or unknown host.
The routine
.Xr herror 3
can be used to print an error message describing the failure.
If its argument
.Fa string
is
.Pf non- Dv NULL ,
it is printed, followed by a colon and a space.
The error message is printed with a trailing newline.
.Pp
The variable
.Va h_errno
can have the following values:
.Bl -tag -width ".Dv HOST_NOT_FOUND"
.It Dv HOST_NOT_FOUND
No such host is known.
.It Dv NO_RECOVERY
Some unexpected server failure was encountered.
This is a non-recoverable error.
.El
.Pp
The
.Fn bt_getprotoent ,
.Fn bt_getprotobyname ,
and
.Fn bt_getprotobynumber
return
.Dv NULL
on EOF or error.
.Sh SEE ALSO
.Xr gethostbyaddr 3 ,
.Xr gethostbyname 3 ,
.Xr getprotobyname 3 ,
.Xr getprotobynumber 3 ,
.Xr herror 3 ,
.Xr inet_aton 3 ,
.Xr inet_ntoa 3
.Sh HISTORY
.Nm libbluetooth
first appeared in
.Fx
was ported to
.Nx 4.0
and extended by
.An Iain Hibbert
for Itronix, Inc.
.Sh AUTHORS
.An Maksim Yevmenkin Aq Mt m_evmenkin@yahoo.com
.An Iain Hibbert
.Sh CAVEATS
The
.Fn bt_gethostent
function reads the next line of
.Pa /etc/bluetooth/hosts ,
opening the file if necessary.
.Pp
The
.Fn bt_sethostent
function opens and/or rewinds the
.Pa /etc/bluetooth/hosts
file.
.Pp
The
.Fn bt_getprotoent
function reads the next line of
.Pa /etc/bluetooth/protocols ,
opening the file if necessary.
.Pp
The
.Fn bt_setprotoent
function opens and/or rewinds the
.Pa /etc/bluetooth/protocols
file.
.Sh BUGS
These functions use static data storage;
if the data is needed for future use, it should be
copied before any subsequent calls overwrite it.