SDP(3) BSD Library Functions Manual SDP(3)
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
sdp_open(const bdaddr_t *laddr, const bdaddr_t *raddr);
sdp_open_local(const char *control);
sdp_service_search(sdp_session_t ss, sdp_data_t *ssp, uint32_t *handlep, int *num);
sdp_service_attribute(sdp_session_t ss, uint32_t handle, sdp_data_t *ail,
sdp_service_search_attribute(sdp_session_t ss, sdp_data_t *ssp, sdp_data_t *ail,
sdp_record_insert(sdp_session_t ss, bdaddr_t *bdaddr, uint32_t *handlep,
sdp_record_update(sdp_session_t ss, uint32_t handle, sdp_data_t *record);
sdp_record_remove(sdp_session_t ss, uint32_t handle);
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, providing access to com-
plete ServiceSearch, ServiceAttribute or ServiceSearchAttribute transactions and using SDP
data element lists directly which can be constructed and parsed with the sdp_data(3) library
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 service record will be matched when all
the UUIDs from the ServiceSearchPattern 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 consist 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 element. 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 ServiceName string in the native language with an
associated LanguageBaseAttributeIDList although this is not currently enforced.
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.
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.
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 ServiceSearchPattern 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 Ser-
viceRecords matching the ServiceSearchPattern ssp will be parsed using the AttributeI-
DList ail. If the transaction succeeds, the response data buffer will contain a valid
data element 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 Bluetooth controller with that BD_ADDR.
When the handlep pointer is non NULL, the resulting ServiceRecordHandle will be writ-
ten 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
Remove a ServiceRecord owned by this session. handle is the identifier returned by
the sdp_record_insert() call.
A single response buffer is maintained for each session, so the results of a ServiceAt-
tribute 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
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 con-
nected with a local socket. See sdpd(8) and your local system administrator for details.
Session open routines will return a session handle on success and NULL on failure. For ser-
vice lookup and record manipulation routines, a boolean value is returned indicating success
or failure. On failure, errno will be set to indicate the error.
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.
sdpquery(1), bluetooth(3), sdp_data(3), sdpd(8)
The "Service Discovery Protocol" section of the Bluetooth Core specifications, available at
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