wsdd - A Web Service Discovery host and client daemon.
wsdd implements both a Web Service Discovery (WSD) host and
a WSD client daemon. The host implementation enables (Samba) hosts, like
your local NAS device, to be found by Web Service Discovery clients like
Windows. The client mode allows searching for other WSD hosts on the local
network.
The default mode of operation is the host mode. The client or
discovery mode must be enabled explictely. Unless configured otherwise, the
host mode is always active. Both modes can be used at the same time.
- -4, --ipv4only
- See below.
- -6, --ipv6only
- Restrict to the given address family. If both options are specified no
addreses will be available and wsdd will exit.
- -A,
--no-autostart
- Do not start networking activities automatically when the program is
started. The API interface (see below) can be used to start and stop the
networking activities while the application is running.
- -c DIRECTORY,
--chroot DIRECTORY
- chroot into the given DIRECTORY after initialization has been
performed and right before the handling of incoming messages starts. The
new root directory can be empty. Consider using the -u option as
well.
- -h, --help
- Show help and exit.
- -H HOPLIMIT,
--hoplimit HOPLIMIT
- Set the hop limit for multicast packets. The default is 1 which should
prevent packets from leaving the local network segment.
- -i INTERFACE/ADDRESS,
--interface INTERFACE/ADDRESS
- Specify on which interfaces wsdd will be listening on. If no interfaces
are specified, all interfaces are used. Loop-back interfaces are never
used, even when explicitly specified. For interfaces with IPv6 addresses,
only link-local addresses will be used for announcing the host on the
network. This option can be provided multiple times in order to restrict
traffic to more than one interface. This option also accepts IP addresses
that the service should bind to. For IPv6, only link local addresses are
actually considered as noted above.
- -s,
--shortlog
- Use a shorter logging format that only includes the level and message.
This is useful in cases where the logging mechanism, like systemd on
Linux, automatically prepends a date and process name plus ID to the log
message.
- -u USER[:GROUP],
--user USER[:GROUP]
- Change user (and group) when running before handling network packets.
Together with -c this option can be used to increase security if
the execution environment, like the init system, cannot ensure this in
another way.
- -U UUID, --uuid
UUID
- The WSD specification requires a device to have a unique address that is
stable across reboots or changes in networks. In the context of the
standard, it is assumed that this is something like a serial number. wsdd
uses the UUID version 5 with the DNS namespace and the host name of the
local machine as inputs. Thus, the host name should be stable and not be
modified, e.g. by DHCP. However, if you want wsdd to use a specific UUID
you can use this option.
- -v, --verbose
- Additively increase verbosity of the log output. A single occurrence of
-v/--verbose sets the log level to INFO. More -v options set the log level
to DEBUG.
- -V, --version
- Show the version number and exit.
- -d DOMAIN, --domain
DOMAIN
- Assume that the host running wsdd joined an ADS domain. This will make
wsdd report the host being a domain member. It disables workgroup
membership reporting. The (provided) hostname is automatically converted
to lower case. Use the `-p` option to change this behavior.
- -n HOSTNAME,
--hostname HOSTNAME
- Override the host name wsdd uses during discovery. By default the
machine's host name is used (look at hostname(1)). Only the host name part
of a possible FQDN will be used in the default case.
- -o, --no-host
- Disable host operation mode. If this option is provided, the host cannot
be discovered by other (Windows) hosts. It can be useful when
client/discovery mode is used and no announcement of the host that runs
wsdd should be made.
- -p,
--preserve-case
- Preserve the hostname as it is. Without this option, the hostname is
converted as follows. For workgroup environments (see -w) the hostname is
made upper case by default. Vice versa it is made lower case for usage in
domains (see -d).
- -t, --no-http
- Do not service HTTP requests of the WSD protocol. This option is intended
for debugging purposes where another process may handle the Get
messages.
- -w WORKGROUP,
--workgroup WORKGROUP
- By default wsdd reports the host is a member of a workgroup rather than a
domain (use the -d/--domain option to override this). With -w/--workgroup
the default workgroup name can be changed. The default work group name is
WORKGROUP. The (provided) hostname is automatically converted to upper
case. Use the `-p` option to change this behavior.
- -D,
--discovery
- Enable discovery mode to search for other WSD hosts/servers. Found hosts
are logged with INFO priority. The server interface (see below) can be
used for a programatic interface. Refer to the man page for details of the
server interface.
- -l PATH/PORT,
--listen PATH/PORT
- Specify the location of the socket for the server programming interface.
If the option value is numeric, it is interpreted as numeric port for a
TCP server port. Then, the server socket is bound to the localhost only.
If the option value is non-numeric, it is assumed to be a path to UNIX
domain socket to which a client can connect to.
wsdd -i eth0 -i eth2 -6
or
wsdd --interface eth0 --interface eth2 --ipv6only
SMB_GROUP=$(grep -i '^workgroup=' smb.conf | cut -f2 -d= | tr -d
'[:blank:]')
wsdd -v -w $SMB_GROUP -u daemon:daemon -c /var/run/wsdd/chroot
Wsdd provides a text-based, line-oriented API interface to query
information and trigger actions. The interface can be used with TCP and UNIX
domain sockets (see -l/--listen option). The TCP socket is bound to
the local host only. The following commands can be issued:
clear - Clear list of discovered devices
Clears the list of all discovered devices. Use the probe
command to search for devices again. This command does not return any data
and is only available in discover mode.
list - List discovered devices
Returns a tab-separated list of discovered devices with the
following information. The possibly empty list of detected hosts is always
terminated with a single dot ('.') in an otherwise empty line. This command
is only available in discover mode.
- UUID
- UUID of the discovered device. Note that a multi-homed device should
appear only once but with multiple addresses (see below)
- name
- The name reported by the device. For discovered Windows hosts, it is the
configured computer name that is reported here.
- association
- Specifies the domain or workgroup to which the discovered host belongs to.
The type of the association (workgroup or domain) is separated from its
value by a colon.
- last_seen
- The date and time the device was last seen as a consequence of Probe/Hello
messages provided in ISO8601 with seconds.
- addresses
- List of all transport addresses that were collected during the discovery
process delimited by commas. Addresses are provided along with the
interface (separated by '%') on which they were discovered. IPv6 addresses
are reported on square brackets. Note that the reported addresses may not
match the actual device on which the device may be reached.
probe [INTERFACE] - Search for devices
Triggers a Probe message on the provided INTERFACE (eth0, e.g.) to
search for WSD hosts. If no interface is provided, all interfaces wsdd
listens on are probed. A Probe messages initiates the discovery message
flow. It may take some time for hosts to be actually discovered. This
command does not return any data and is only available in discovery
mode.
start - Start networking activities
This command starts the networking acitivies of wsdd if they
haven't been started yet. "Hello" messages are emitted and the
host is announced on the network(s) when the host mode is active. If the
discovery mode is enabled a probe process is also started.
stop - Stop networking activities
This is the reverse operation to start. When this command is
received, "Bye" messages are sent in order to notify hosts in the
network about the host's disappearance. All networking sockets used for the
WSD protocol are closed as well. Activities can be restarted with the start
operation.
wsdd does not implement any security feature, e.g. by using TLS
for the http service. This is because wsdd's intended usage is within
private, i.e. home, LANs. The Hello message contains the hosts
transport address, i.e. the IP address which speeds up discovery (avoids
Resolve message).
If wsdd is running on FreeBSD using IPv6 only, the host running
wsdd may not be reliably discovered. The reason appears to be that Windows
is not always able to connect to the HTTP service for unknown reasons. As a
workaround, run wsdd with IPv4 only.
If tunnel/bridge interfaces like those created by OpenVPN or
Docker exist, they may interfere with wsdd if executed without providing an
interface that it should bind to (so it binds to all). In such cases, the
wsdd hosts appears after wsdd has been started but it disappears when an
update of the Network view in Windows Explorer is forced, either by
refreshing the view or by a reboot of the Windows machine. To solve this
issue, the interface that is connected to the network on which the host
should be announced needs to be specified with the -i/--interface option.
This prevents the usage of the tunnel/bridge interfaces.
Background: Tunnel/bridge interfaces may cause Resolve
requests from Windows hosts to be delivered to wsdd multiple times, i.e.
duplicates of such request are created. If wsdd receives such a request
first from a tunnel/bridge it uses the transport address (IP address) of
that interface and sends the response via unicast. Further duplicates are
not processed due to the duplicate message detection which is based on
message UUIDs. The Windows host which receives the response appears to
detect a mismatch between the transport address in the ResolveMatch
message (which is the tunnel/bridge address) and the IP of the sending
host/interface (LAN IP, e.g.). Subsequently, the wsdd host is ignored by
Windows.