SDP(3) BSD Library Functions Manual SDP(3)NAME
sdp_open, sdp_open_local, sdp_close, sdp_service_search,
sdp_service_attribute, sdp_service_search_attribute, sdp_record_insert,
sdp_record_update, sdp_record_remove — Service Discovery Protocol session
routines
LIBRARY
library “libbluetooth”
SYNOPSIS
#include <sdp.h>
sdp_session_t
sdp_open(const bdaddr_t *laddr, const bdaddr_t *raddr);
sdp_session_t
sdp_open_local(const char *control);
void
sdp_close(sdp_session_t ss);
bool
sdp_service_search(sdp_session_t ss, sdp_data_t *ssp, uint32_t *handlep,
int *num);
bool
sdp_service_attribute(sdp_session_t ss, uint32_t handle, sdp_data_t *ail,
sdp_data_t *response);
bool
sdp_service_search_attribute(sdp_session_t ss, sdp_data_t *ssp,
sdp_data_t *ail, sdp_data_t *response);
bool
sdp_record_insert(sdp_session_t ss, bdaddr_t *bdaddr, uint32_t *handlep,
sdp_data_t *record);
bool
sdp_record_update(sdp_session_t ss, uint32_t handle, sdp_data_t *record);
bool
sdp_record_remove(sdp_session_t ss, uint32_t handle);
DESCRIPTION
The SDP library provides means for client programs to perform Bluetooth
Service Discovery, and to advertise Service Records on the local host.
The Service Discovery API reflects the Bluetooth SDP specification, pro‐
viding access to complete ServiceSearch, ServiceAttribute or Service‐
SearchAttribute transactions and using SDP data element lists directly
which can be constructed and parsed with the sdp_data(3) library func‐
tions.
The ServiceSearchPattern is a list of UUID data elements. The list must
contain at least one UUID and the maximum number of UUIDs is 12. A ser‐
vice record will be matched when all the UUIDs from the ServiceSearchPat‐
tern are contained in the record.
The AttributeIDList is a list of data elements where each is either an
attribute ID encoded as an unsigned 16-bit integer, or a range of
attribute IDs encoded as an unsigned 32-bit integer where the high order
16-bits are the start of the range and the low order 16-bits are the end
of the range (inclusive). The AttributeIDList should be arranged in
ascending order and there should be no duplicate attribute ID values. If
NULL is passed, all attributes (0x0000-0xffff) will be requested.
ServiceRecords to be registered with the local sdpd(8) server should con‐
sist of a list of attribute ID/value pairs, where the attribute ID is a
16-bit unsigned integer element, and the attribute value is any data ele‐
ment. The attribute IDs should be in ascending order, and the first one
must be SDP_ATTR_SERVICE_RECORD_HANDLE (0x0000), otherwise the server
will reject the record. For consistency, records should also contain a
BrowseGroupList with the PublicBrowseGroup UUID, plus at least a Service‐
Name string in the native language with an associated LanguageBaseAt‐
tributeIDList although this is not currently enforced.
FUNCTIONS
sdp_open(laddr, raddr)
Open a SDP session to a remote Bluetooth device. laddr refers to
the local bluetooth device address and may be NULL in which case it
will default to BDADDR_ANY.
sdp_open_local(control)
Open a SDP session to a server using a local socket. The control
socket path may be given as NULL in which case the default control
path /var/run/sdp will be used.
sdp_close(ss)
Close SDP session and release all resources.
sdp_service_search(ss, ssp, handlep, num)
Perform a complete ServiceSearch transaction on the SDP session.
At most num service record handles matching the ServiceSearchPat‐
tern ssp will be returned in the array pointed to by handlep.
sdp_service_attribute(ss, handle, ail, response)
Perform a complete ServiceAttribute transaction on the SDP session.
The ServiceRecord with ServiceRecordHandle handle will be parsed
using the AttributeIDList ail. If the transaction succeeds, the
response data buffer will contain a validated data element list of
attribute ID/value pairs from the selected record.
sdp_service_search_attribute(ss, ssp, ail, response)
Perform a complete ServiceSearchAttribute transaction on the SDP
session. All ServiceRecords matching the ServiceSearchPattern ssp
will be parsed using the AttributeIDList ail. If the transaction
succeeds, the response data buffer will contain a valid data ele‐
ment list of sequences, where each sequence is the attribute
ID/value list from a matched record.
sdp_record_insert(ss, bdaddr, handlep, record)
Insert a ServiceRecord record. If bdaddr is given, the service
record will be restricted to clients connecting through the Blue‐
tooth controller with that BD_ADDR. When the handlep pointer is
non NULL, the resulting ServiceRecordHandle will be written to the
address given. The record will be valid while the session is
active and will be purged when the session is closed.
sdp_record_update(ss, handle, record)
Update a ServiceRecord that is owned by this session. handle is
the identifier returned by the sdp_record_insert() call, and record
is the updated ServiceRecord as described above.
sdp_record_remove(ss, handle)
Remove a ServiceRecord owned by this session. handle is the iden‐
tifier returned by the sdp_record_insert() call.
A single response buffer is maintained for each session, so the results
of a ServiceAttribute or ServiceSearchAttribute request will only be
valid until another request is made or the session is closed. The SDP
specifications do not mandate a limit on the size of the response buffer
but this implementation has a default limit of UINT16_MAX bytes. This
limit can be increased at runtime by setting the environment variable
SDP_RESPONSE_MAX to a numeric value.
Records are only allowed to be removed or updated by the session that
inserted them, and records will be removed automatically when the session
is closed. Further, manipulating service records will normally only be
possible for privileged users on a SDP session connected with a local
socket. See sdpd(8) and your local system administrator for details.
RETURN VALUES
Session open routines will return a session handle on success and NULL on
failure. For service lookup and record manipulation routines, a boolean
value is returned indicating success or failure. On failure, errno will
be set to indicate the error.
FILES
/var/run/sdp
ERRORS
In addition to errors returned by the standard C library IO functions,
the following errors may be detected by libbluetooth:
[EINVAL] A provided function argument was not valid.
[EIO] A response from the remote server was not understood.
[ENOATTR] The record handle did not exist on the server.
SEE ALSOsdpquery(1), bluetooth(3), sdp_data(3), sdpd(8)
The "Service Discovery Protocol" section of the Bluetooth Core specifica‐
tions, available at "http://www.bluetooth.com/"
HISTORY
The first Service Discovery implementation was written for FreeBSD and
was ported to NetBSD 4.0. This, the second version API, was designed by
Iain Hibbert for NetBSD 6.0 in order to simplify the sdpd(8) daemon and
allow client code greater control over all aspects of the service
records. The original API is still available when SDP_COMPAT is defined
but will eventually be removed.
BSD May 7, 2009 BSD