SDPD(8) | System Manager's Manual | SDPD(8)

# NAME

`sdpd` — Bluetooth Service Discovery Protocol daemon

# SYNOPSIS

`sdpd` | [`-dh`] [`-c` path] [`-G` group] [`-g` group] [`-u` user]

# DESCRIPTION

The `sdpd` daemon keeps a database of Bluetooth Service Records registered on the host and responds to Service Discovery inquiries from remote Bluetooth devices.

In order to discover services, remote Bluetooth devices send Service Search and Service Attribute or Service Search Attribute requests over Bluetooth L2CAP connections on the SDP PSM (0x0001). The `sdpd` daemon will try to find matching Service Records in its Service Database and will return the requested record extracts for the remote device to interpret. The remote device will then make a separate connection in order to access the service.

Bluetooth applications, running on the host, are able to insert, remove and update Service Records with the `sdpd` daemon via the control socket. It is possible to query entire contents of the Service Database locally with sdpquery(1) using the `-l` option.

The command line options are as follows:

`-c` path
  Specify path to the control socket. The default path is /var/run/sdp.
`-d`
  Do not detach from the controlling terminal.
`-G` group
  Grant permission to members of the group to modify the `sdpd` Service Database.
`-g` group
  Specifies the group the `sdpd` should run as after it initializes. The value specified may be either a group name or a numeric group ID. This only works if `sdpd` was started as root. The default group name is “`_sdpd`”.
`-h`
  Display usage message and exit.
`-u` user
  Specifies the user the `sdpd` should run as after it initializes. The value specified may be either a user name or a numeric user ID. This only works if `sdpd` was started as root. The default user name is “`_sdpd`”.

# FILES

/var/run/sdp

# SEE ALSO

sdpquery(1), sdp(3)

The "Service Discovery Protocol" section of the Bluetooth Core specifications, available at http://www.bluetooth.com/

# HISTORY

The original `sdpd` daemon first appeared in FreeBSD 5.3 and was imported into NetBSD 4.0 by Iain Hibbert under the sponsorship of Itronix, Inc. This version was rewritten by Iain Hibbert for NetBSD 6.0 in order to allow Bluetooth applications to fully specify service records.

# AUTHORS

Maksim Yevmenkin <m_evmenkin@yahoo.com>
Iain Hibbert

# CAVEATS

The `sdpd` daemon will listen for incoming L2CAP connections on a wildcard BD_ADDR.

In case of multiple Bluetooth controllers connected to the same host it is possible to limit visibility of Service Records according to the controller the connection is made through.

Requests to insert, remove or update service records can only be made via the control socket. The `sdpd` daemon will check the peer's credentials and will only accept the request when the peer is the superuser, of if the peer is a member of the group specified with the `-G` option.

The `sdpd` daemon does not check for duplicated Service Records and only performs minimal validation of the record data sent in the Insert/Update Record requests. It is assumed that application must obtain all required resources such as RFCOMM channels etc., before registering the service.

# BUGS

`sdpd` only ever generates 16-bit sequence headers, so if a response was to grow over `UINT16_MAX`, the sequence header will be wrong.

There is no way for clients to discover the maximum packet size that `sdpd` will accept on the local socket. Currently this is `SDP_LOCAL_MTU` as defined in `<bluetooth/sdp.h>`.

May 7, 2009 | NetBSD 11.99