SDP(3) BSD Library Functions Manual SDP(3)NAME
SDP_GET8, SDP_GET16, SDP_GET32, SDP_GET64, SDP_GET128, SDP_GET_UUID128,
SDP_PUT8, SDP_PUT16, SDP_PUT32, SDP_PUT64, SDP_PUT128, SDP_PUT_UUID128,
sdp_open, sdp_open_local, sdp_close, sdp_error, sdp_search,
sdp_attr2desc, sdp_uuid2desc — Bluetooth SDP routines
LIBRARY
library “libsdp”
SYNOPSIS
#include <bluetooth.h>
#include <sdp.h>
SDP_GET8(b, cp);
SDP_GET16(s, cp);
SDP_GET32(l, cp);
SDP_GET64(l, cp);
SDP_GET128(l, cp);
SDP_GET_UUID128(l, cp);
SDP_PUT8(b, cp);
SDP_PUT16(s, cp);
SDP_PUT32(l, cp);
SDP_PUT64(l, cp);
SDP_PUT128(l, cp);
SDP_PUT_UUID128(l, cp);
void *
sdp_open(bdaddr_t const *l, bdaddr_t const *r);
void *
sdp_open_local(char const *control);
int32_t
sdp_close(void *xs);
int32_t
sdp_error(void *xs);
int32_t
sdp_search(void *xs, uint32_t plen, uint16_t const *pp, uint32_t alen,
uint32_t const *ap, uint32_t vlen, sdp_attr_t *vp);
char const * const
sdp_attr2desc(uint16_t attr);
char const * const
sdp_uuid2desc(uint16_t uuid);
int32_t
sdp_register_service(void *xss, uint16_t uuid, bdaddr_p const bdaddr,
uint8_t const *data, uint32_t datalen, uint32_t *handle);
int32_t
sdp_unregister_service(void *xss, uint32_t handle);
int32_t
sdp_change_service(void *xss, uint32_t handle, uint8_t const *data,
uint32_t datalen);
DESCRIPTION
The SDP_GET8(), SDP_GET16(), SDP_GET32(), SDP_GET64() and SDP_GET128()
macros are used to get byte, short, long, long long and 128-bit integer
from the buffer pointed by cp pointer. The pointer is automatically
advanced.
The SDP_PUT8(), SDP_PUT16(), SDP_PUT32(), SDP_PUT64() and SDP_PUT128()
macros are used to put byte, short, long, long long and 128-bit integer
into the buffer pointed by cp pointer. The pointer is automatically
advanced.
SDP_GET_UUID128() and SDP_PUT_UUID128() macros are used to get and put
128-bit UUID into the buffer pointed by cp pointer. The pointer is auto‐
matically advanced.
The sdp_open() and sdp_open_local() functions each return a pointer to an
opaque object describing SDP session. The l argument passed to
sdp_open() function should point to a source BD_ADDR. If source BD_ADDR
is NULL then source address NG_HCI_BDADDR_ANY is used. The r argument
passed to sdp_open() function should point to a non-NULL remote BD_ADDR.
Remote BD_ADDR cannot be NG_HCI_BDADDR_ANY. The sdp_open_local() func‐
tion takes path to the control socket and opens a connection to a local
SDP server. If path to the control socket is NULL then default
/var/run/sdp path will be used.
The sdp_close() function terminates active SDP session and deletes SDP
session object. The xs parameter should point to a valid SDP session
object created with sdp_open() or sdp_open_local().
The sdp_error() function returns last error that is stored inside SDP
session object. The xs parameter should point to a valid SDP session
object created with sdp_open() or sdp_open_local(). The error value
returned can be converted to a human readable message by calling
strerror(3) function.
The sdp_search() function is used to perform SDP Service Search Attribute
Request. The xs parameter should point to a valid SDP session object
created with sdp_open() or sdp_open_local(). The pp parameter is a Ser‐
vice Search Pattern - an array of one or more Service Class IDs. The
maximum number of Service Class IDs in the array is 12. The plen parame‐
ter is the length of the Service Search pattern. The ap parameter is an
Attribute ID Range List - an array of one or more SDP Attribute ID Range.
Each attribute ID Range is encoded as a 32-bit unsigned integer data ele‐
ment, where the high order 16 bits are interpreted as the beginning
attribute ID of the range and the low order 16 bits are interpreted as
the ending attribute ID of the range. The attribute IDs contained in the
Attribute ID Ranges List must be listed in ascending order without dupli‐
cation of any attribute ID values. Note that all attributes may be
requested by specifying a range of 0x0000-0xFFFF. The alen parameter is
the length of the Attribute ID Ranges List. The SDP_ATTR_RANGE(lo, hi)
macro can be used to prepare Attribute ID Range. The vp parameter should
be an array of sdp_attr_t structures. Each sdp_attr_t structure
describes single SDP attribute and defined as follows:
struct sdp_attr {
uint16_t flags;
#define SDP_ATTR_OK (0 << 0)
#define SDP_ATTR_INVALID (1 << 0)
#define SDP_ATTR_TRUNCATED (1 << 1)
uint16_t attr; /* SDP_ATTR_xxx */
uint32_t vlen; /* length of the value[] in bytes */
uint8_t *value; /* base pointer */
};
typedef struct sdp_attr sdp_attr_t;
typedef struct sdp_attr * sdp_attr_p;
The caller of the sdp_search() function is expected to prepare the array
of sdp_attr structures and for each element of the array both vlen and
value must be set. The sdp_search() function will fill each sdp_attr_t
structure with attribute and value, i.e., it will set flags, attr and
vlen fields. The actual value of the attribute will be copied into value
buffer. Note: attributes are returned in the order they appear in the
Service Search Attribute Response. SDP server could return several
attributes for the same record. In this case the order of the attributes
will be: all attributes for the first records, then all attributes for
the secord record etc.
The sdp_attr2desc() and sdp_uuid2desc() functions each take a numeric
attribute ID/UUID value and convert it to a human readable description.
The sdp_register_service() function is used to register service with the
local SDP server. The xss parameter should point to a valid SDP session
object obtained from sdp_open_local(). The uuid parameter is a SDP Ser‐
vice Class ID for the service to be registered. The bdaddr parameter
should point to a valid BD_ADDR. The service will be only advertised if
request was received by the local device with bdaddr. If bdaddr is set
to NG_HCI_BDADDR_ANY then the service will be advertised to any remote
devices that queries for it. The data and datalen parameters specify
data and size of the data for the service. Upon successful return
sdp_register_service() will populate handle with the SDP record handle.
This parameter is optional and can be set to NULL.
The sdp_unregister_service() function is used to unregister service with
the local SDP server. The xss parameter should point to a valid SDP ses‐
sion object obtained from sdp_open_local(). The handle parameter should
contain a valid SDP record handle of the service to be unregistered.
The sdp_change_service() function is used to change data associated with
the existing service on the local SDP server. The xss parameter should
point to a valid SDP session object obtained from sdp_open_local(). The
handle parameter should contain a valid SDP record handle of the service
to be changed. The data and datalen parameters specify data and size of
the data for the service.
CAVEAT
When registering services with the local SDP server the application must
keep the SDP session open. If SDP session is closed then the local SDP
server will remove all services that were registered over the session.
The application is allowed to change or unregister service if it was reg‐
istered over the same session.
EXAMPLES
The following example shows how to get SDP_ATTR_PROTOCOL_DESCRIPTOR_LIST
attribute for the SDP_SERVICE_CLASS_SERIAL_PORT service from the remote
device.
bdaddr_t remote;
uint8_t buffer[1024];
void *ss = NULL;
uint16_t serv = SDP_SERVICE_CLASS_SERIAL_PORT;
uint32_t attr = SDP_ATTR_RANGE(
SDP_ATTR_PROTOCOL_DESCRIPTOR_LIST,
SDP_ATTR_PROTOCOL_DESCRIPTOR_LIST);
sdp_attr_t proto = { SDP_ATTR_INVALID,0,sizeof(buffer),buffer };
/* Obtain/set remote BDADDR here */
if ((ss = sdp_open(NG_HCI_BDADDR_ANY, remote)) == NULL)
/* exit ENOMEM */
if (sdp_error(ss) != 0)
/* exit sdp_error(ss) */
if (sdp_search(ss, 1, &serv, 1, &attr, 1, &proto) != 0)
/* exit sdp_error(ss) */
if (proto.flags != SDP_ATTR_OK)
/* exit see proto.flags for details */
/* If we got here then we have attribute value in proto.value */
DIAGNOSTICS
Both sdp_open() and sdp_open_local() will return NULL if memory alloca‐
tion for the new SDP session object fails. If the new SDP object was
created then caller is still expected to call sdp_error() to check if
there was connection error.
The sdp_search(), sdp_register_service(), sdp_unregister_service() and
sdp_change_service() functions return non-zero value on error. The call‐
er is expected to call sdp_error() to find out more about error.
SEE ALSObluetooth(3), strerror(3), sdpcontrol(8), sdpd(8)AUTHORS
Maksim Yevmenkin ⟨m_evmenkin@yahoo.com⟩
BUGS
Most likely. Please report bugs if found.
BSD May 27, 2005 BSD