******************************
imtcp: TCP Syslog Input Module
******************************

===========================  ===========================================================================
**Module Name:**             **imtcp**
**Author:**                  `Rainer Gerhards <https://rainer.gerhards.net/>`_ <rgerhards@adiscon.com>
===========================  ===========================================================================


Purpose
=======

Provides the ability to receive syslog messages via TCP. Encryption is
natively provided by selecting the appropriate network stream driver
and can also be provided by using `stunnel <rsyslog_stunnel.html>`_ (an
alternative is the use the `imgssapi <imgssapi.html>`_ module).


Notable Features
================

- :ref:`imtcp-statistic-counter`


Configuration Parameters
========================

.. note::

   Parameter names are case-insensitive.


Module Parameters
-----------------

AddtlFrameDelimiter
^^^^^^^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "integer", "-1", "no", "``$InputTCPServerAddtlFrameDelimiter``"

.. versionadded:: 4.3.1

This directive permits to specify an additional frame delimiter for
Multiple receivers may be configured by specifying $InputTCPServerRun
multiple times.


DisableLFDelimiter
^^^^^^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "binary", "off", "no", "``$InputTCPServerDisableLFDelimiter``"

Industry-standard plain text tcp syslog uses the LF to delimit
syslog frames. However, some users brought up the case that it may be
useful to define a different delimiter and totally disable LF as a
delimiter (the use case named were multi-line messages). This mode is
non-standard and will probably come with a lot of problems. However,
as there is need for it and it is relatively easy to support, we do
so. Be sure to turn this setting to "on" only if you exactly know
what you are doing. You may run into all sorts of troubles, so be
prepared to wrangle with that!


MaxFrameSize
^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "integer", "200000", "no", "none"

When in octet counted mode, the frame size is given at the beginning
of the message. With this parameter the max size this frame can have
is specified and when the frame gets to large the mode is switched to
octet stuffing.
The max value this parameter can have was specified because otherwise
the integer could become negative and this would result in a
Segmentation Fault. (Max Value = 200000000)


NotifyOnConnectionOpen
^^^^^^^^^^^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "binary", "off", "no", ""

Instructs imtcp to emit a message if the remote peer closes a
connection.


NotifyOnConnectionOpen
^^^^^^^^^^^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "binary", "off", "no", "none"

Instructs imtcp to emit a message if the remote peer opens a
connection.


NotifyOnConnectionClose
^^^^^^^^^^^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "binary", "off", "no", "``$InputTCPServerNotifyOnConnectionClose``"

Instructs imtcp to emit a message if the remote peer closes a
connection.



KeepAlive
^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "binary", "off", "no", "``$InputTCPServerKeepAlive``"

Enable or disable keep-alive packets at the tcp socket layer. The
default is to disable them.


KeepAlive.Probes
^^^^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "integer", "0", "no", "``$InputTCPServerKeepAlive_probes``"

The number of unacknowledged probes to send before considering the
connection dead and notifying the application layer. The default, 0,
means that the operating system defaults are used. This has only
effect if keep-alive is enabled. The functionality may not be
available on all platforms.


KeepAlive.Time
^^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "integer", "0", "no", "``$InputTCPServerKeepAlive_time``"

The interval between the last data packet sent (simple ACKs are not
considered data) and the first keepalive probe; after the connection
is marked to need keepalive, this counter is not used any further.
The default, 0, means that the operating system defaults are used.
This has only effect if keep-alive is enabled. The functionality may
not be available on all platforms.


KeepAlive.Interval
^^^^^^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "integer", "0", "no", ""

.. versionadded:: 8.2106.0

The interval for keep alive packets.




FlowControl
^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "binary", "on", "no", "``$InputTCPFlowControl``"

This setting specifies whether some message flow control shall be
exercised on the related TCP input. If set to on, messages are
handled as "light delayable", which means the sender is throttled a
bit when the queue becomes near-full. This is done in order to
preserve some queue space for inputs that can not throttle (like
UDP), but it may have some undesired effect in some configurations.
Still, we consider this as a useful setting and thus it is the
default. To turn the handling off, simply configure that explicitly.


MaxListeners
^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "integer", "20", "no", "``$InputTCPMaxListeners``"

Sets the maximum number of listeners (server ports) supported.
This must be set before the first $InputTCPServerRun directive.


MaxSessions
^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "integer", "200", "no", "``$InputTCPMaxSessions``"

Sets the maximum number of sessions supported. This must be set
before the first $InputTCPServerRun directive.


StreamDriver.Name
^^^^^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "string", "none", "no", "none"

Selects :doc:`network stream driver <../../concepts/netstrm_drvr>`
for all inputs using this module.


StreamDriver.Mode
^^^^^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "integer", "0", "no", "``$InputTCPServerStreamDriverMode``"

Sets the driver mode for the currently selected
:doc:`network stream driver <../../concepts/netstrm_drvr>`.
<number> is driver specific.


StreamDriver.AuthMode
^^^^^^^^^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "string", "none", "no", "``$InputTCPServerStreamDriverAuthMode``"

Sets stream driver authentication mode. Possible values and meaning
depend on the
:doc:`network stream driver <../../concepts/netstrm_drvr>`.
used.


StreamDriver.PermitExpiredCerts
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "string", "warn", "no", "none"

Controls how expired certificates will be handled when stream driver is in TLS mode.
It can have one of the following values:

-  on = Expired certificates are allowed

-  off = Expired certificates are not allowed  (Default, changed from warn to off since Version 8.2012.0)

-  warn = Expired certificates are allowed but warning will be logged


StreamDriver.CheckExtendedKeyPurpose
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "binary", "off", "no", "none"

Whether to check also purpose value in extended fields part of certificate 
for compatibility with rsyslog operation. (driver-specific)


StreamDriver.PrioritizeSAN
^^^^^^^^^^^^^^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "binary", "off", "no", "none"

Whether to use stricter SAN/CN matching. (driver-specific)


StreamDriver.TlsVerifyDepth
^^^^^^^^^^^^^^^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "integer", "TLS library default", "no", "none"


Specifies the allowed maximum depth for the certificate chain verification.
Support added in v8.2001.0, supported by GTLS and OpenSSL driver.
If not set, the API default will be used. 
For OpenSSL, the default is 100 - see the doc for more:
https://docs.openssl.org/1.1.1/man3/SSL_CTX_set_verify/
For GnuTLS, the default is 5 - see the doc for more:
https://www.gnutls.org/manual/gnutls.html


PermittedPeer
^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "array", "none", "no", "``$InputTCPServerStreamDriverPermittedPeer``"

Sets permitted peer IDs. Only these peers are able to connect to
the listener. <id-string> semantics depend on the currently
selected AuthMode and
:doc:`network stream driver <../../concepts/netstrm_drvr>`.
PermittedPeer may not be set in anonymous modes. PermittedPeer may
be set either to a single peer or an array of peers either of type
IP or name, depending on the tls certificate.

Single peer:
PermittedPeer="127.0.0.1"

Array of peers:
PermittedPeer=["test1.example.net","10.1.2.3","test2.example.net","..."]


DiscardTruncatedMsg
^^^^^^^^^^^^^^^^^^^

Normally when a message is truncated in octet stuffing mode the part that
is cut off is processed as the next message. When this parameter is activated,
the part that is cut off after a truncation is discarded and not processed.

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "binary", "off", "no", "none"


gnutlsPriorityString
^^^^^^^^^^^^^^^^^^^^

The "gnutls priority string" parameter in rsyslog offers enhanced
customization for secure communications, allowing detailed configuration
of TLS driver properties. This includes specifying handshake algorithms
and other settings for GnuTLS, as well as implementing OpenSSL
configuration commands. Initially developed for GnuTLS, the "gnutls
priority string" has evolved since version v8.1905.0 to also support
OpenSSL, broadening its application and utility in network security
configurations. This update signifies a key advancement in rsyslog's
capabilities, making the "gnutls priority string" an essential
feature for advanced TLS configuration.

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "string", "none", "no", "none"

.. versionadded:: 8.29.0


**Configuring Driver-Specific Properties**

This configuration string is used to set properties specific to different drivers. Originally designed for the GnuTLS driver, it has been extended to support OpenSSL configuration commands from version v8.1905.0 onwards.

**GNUTLS Configuration**

In GNUTLS, this setting determines the handshake algorithms and options for the TLS session. It's designed to allow user overrides of the library's default settings. If you leave this parameter unset (NULL), the system will revert to the default settings. For more detailed information on priority strings in GNUTLS, you can refer to the GnuTLS Priority Strings Documentation available at [GnuTLS Website](https://gnutls.org/manual/html_node/Priority-Strings.html).

**OpenSSL Configuration**

This feature is compatible with OpenSSL Version 1.0.2 and above. It enables the passing of configuration commands to the OpenSSL library. You can find a comprehensive list of commands and their acceptable values in the OpenSSL Documentation, accessible at [OpenSSL Documentation](https://docs.openssl.org/1.0.2/man3/SSL_CONF_cmd/).

**General Configuration Guidelines**

The configuration can be formatted as a single line or across multiple lines. Each command within the configuration is separated by a linefeed (`\n`). To differentiate between a command and its corresponding value, use an equal sign (`=`). Below are some examples to guide you in formatting these commands.


Example 1
---------

This will allow all protocols except for SSLv2 and SSLv3:

.. code-block:: none

   gnutlsPriorityString="Protocol=ALL,-SSLv2,-SSLv3"


Example 2
---------

This will allow all protocols except for SSLv2, SSLv3 and TLSv1.
It will also set the minimum protocol to TLSv1.2

.. code-block:: none

   gnutlsPriorityString="Protocol=ALL,-SSLv2,-SSLv3,-TLSv1
   MinProtocol=TLSv1.2"


PreserveCase
^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "boolean", "on", "no", "none"

.. versionadded:: 8.37.0

This parameter is for controlling the case in fromhost.  If preservecase is set to "off", the case in fromhost is not preserved.  E.g., 'host1.example.org' the message was received from 'Host1.Example.Org'.  Default to "on" for the backward compatibility.


Input Parameters
----------------

Port
^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "string", "none", "yes", "``$InputTCPServerRun``"

Starts a TCP server on selected port. If port zero is selected, the OS automatically
assigns a free port. Use `listenPortFileName` in this case to obtain the information
of which port was assigned.


ListenPortFileName
^^^^^^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "string", "none", "no", "none"

This parameter specifies a file name into which the port number this input listens
on is written. It is primarily intended for cases when `port` is set to 0 to let
the OS automatically assign a free port number.


Address
^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "string", "none", "no", "none"

On multi-homed machines, specifies to which local address the
listener should be bound.


Name
^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "string", "imtcp", "no", "``$InputTCPServerInputName``"

Sets a name for the inputname property. If no name is set "imtcp" is
used by default. Setting a name is not strictly necessary, but can be
useful to apply filtering based on which input the message was
received from.


Ruleset
^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "string", "none", "no", "``$InputTCPServerBindRuleset``"

Binds the listener to a specific :doc:`ruleset <../../concepts/multi_ruleset>`.


SupportOctetCountedFraming
^^^^^^^^^^^^^^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "binary", "on", "no", "``$InputTCPServerSupportOctetCountedFraming``"

If set to "on", the legacy octed-counted framing (similar to RFC5425
framing) is activated. This should be left unchanged until you know
very well what you do. It may be useful to turn it off, if you know
this framing is not used and some senders emit multi-line messages
into the message stream.


SocketBacklog
^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "integer", "10% of configured connections", "no", "none"

Specifies the backlog parameter passed to the `listen()` system call. This parameter
defines the maximum length of the queue for pending connections, which includes
partially established connections (those in the SYN-ACK handshake phase) and fully
established connections waiting to be accepted by the application.

**Available starting with the 8.2502.0 series.**

For more details, refer to the `listen(2)` man page.

By default, the value is set to 10% of the configured connections
to accommodate modern workloads. It can
be adjusted to suit specific requirements, such as:

- **High rates of concurrent connection attempts**: Increasing this value helps handle bursts of incoming connections without dropping them.
- **Test environments with connection flooding**: Larger values are recommended to prevent SYN queue overflow.
- **Servers with low traffic**: Lower values may be used to reduce memory usage.

The effective backlog size is influenced by system-wide kernel settings, particularly `net.core.somaxconn` and `net.ipv4.tcp_max_syn_backlog`. The smaller value between this parameter and the kernel limits is used as the actual backlog.


RateLimit.Interval
^^^^^^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "integer", "0", "no", "none"

Specifies the rate-limiting interval in seconds. Default value is 0,
which turns off rate limiting. Set it to a number of seconds (5
recommended) to activate rate-limiting.


RateLimit.Burst
^^^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "integer", "10000", "no", "none"

Specifies the rate-limiting burst in number of messages. Default is
10,000.


listenPortFileName
^^^^^^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "string", "none", "no", "none"

.. versionadded:: 8.38.0

With this parameter you can specify the name for a file. In this file the
port, imtcp is connected to, will be written.
This parameter was introduced because the testbench works with dynamic ports.

.. note::

   If this parameter is set, 0 will be accepted as the port. Otherwise it
   is automatically changed to port 514


StreamDriver.Name
^^^^^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "string", "module parameter", "no", "none"

.. versionadded:: 8.2106.0

This permits to override the equally-named module parameter on the input()
level. For further details, see the module parameter.


StreamDriver.Mode
^^^^^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "integer", "module parameter", "no", "``$InputTCPServerStreamDriverMode``"

.. versionadded:: 8.2106.0

This permits to override the equally-named module parameter on the input()
level. For further details, see the module parameter.


StreamDriver.AuthMode
^^^^^^^^^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "string", "module parameter", "no", "``$InputTCPServerStreamDriverAuthMode``"

.. versionadded:: 8.2106.0

This permits to override the equally-named module parameter on the input()
level. For further details, see the module parameter.


StreamDriver.PermitExpiredCerts
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "string", "module parameter", "no", "none"

.. versionadded:: 8.2106.0

This permits to override the equally-named module parameter on the input()
level. For further details, see the module parameter.


StreamDriver.CheckExtendedKeyPurpose
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "binary", "module parameter", "no", "none"

.. versionadded:: 8.2106.0

This permits to override the equally-named module parameter on the input()
level. For further details, see the module parameter.


StreamDriver.PrioritizeSAN
^^^^^^^^^^^^^^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "binary", "module parameter", "no", "none"

.. versionadded:: 8.2106.0

This permits to override the equally-named module parameter on the input()
level. For further details, see the module parameter.


StreamDriver.TlsVerifyDepth
^^^^^^^^^^^^^^^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "integer", "module parameter", "no", "none"

.. versionadded:: 8.2106.0

This permits to override the equally-named module parameter on the input()
level. For further details, see the module parameter.


streamDriver.CAFile
^^^^^^^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "string", "global parameter", "no", "none"

.. versionadded:: 8.2108.0

This permits to override the DefaultNetstreamDriverCAFile global parameter on the input()
level. For further details, see the global parameter.

streamDriver.CRLFile
^^^^^^^^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "optional", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "string", "global parameter", "no", "none"

.. versionadded:: 8.2308.0

This permits to override the CRL (Certificate revocation list) file set via `global()` config
object at the per-action basis. This parameter is ignored if the netstream driver and/or its
mode does not need or support certificates.

streamDriver.KeyFile
^^^^^^^^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "string", "global parameter", "no", "none"

.. versionadded:: 8.2108.0

This permits to override the DefaultNetstreamDriverKeyFile global parameter on the input()
level. For further details, see the global parameter.


streamDriver.CertFile
^^^^^^^^^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "string", "global parameter", "no", "none"

.. versionadded:: 8.2108.0

This permits to override the DefaultNetstreamDriverCertFile global parameter on the input()
level. For further details, see the global parameter.


PermittedPeer
^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "array", "none", "no", "equally-named module parameter"
.. versionadded:: 8.2112.0

This permits to override the equally-named module parameter on the input()
level. For further details, see the module parameter.


gnutlsPriorityString
^^^^^^^^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "string", "module parameter", "no", "none"
.. versionadded:: 8.2106.0

This permits to override the equally-named module parameter on the input()
level. For further details, see the module parameter.


MaxSessions
^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "integer", "module parameter", "no", ""

.. versionadded:: 8.2106.0

This permits to override the equally-named module parameter on the input()
level. For further details, see the module parameter.


MaxListeners
^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "integer", "module parameter", "no", ""

.. versionadded:: 8.2106.0

This permits to override the equally-named module parameter on the input()
level. For further details, see the module parameter.


FlowControl
^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "binary", "module parameter", "no", ""

.. versionadded:: 8.2106.0

This permits to override the equally-named module parameter on the input()
level. For further details, see the module parameter.


DisableLFDelimiter
^^^^^^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "binary", "module parameter", "no", ""


.. versionadded:: 8.2106.0

This permits to override the equally-named module parameter on the input()
level. For further details, see the module parameter.


DiscardTruncatedMsg
^^^^^^^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "binary", "module parameter", "no", "none"

.. versionadded:: 8.2106.0

This permits to override the equally-named module parameter on the input()
level. For further details, see the module parameter.


NotifyOnConnectionClose
^^^^^^^^^^^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "binary", "module parameter", "no", "none"

.. versionadded:: 8.2106.0

This permits to override the equally-named module parameter on the input()
level. For further details, see the module parameter.


AddtlFrameDelimiter
^^^^^^^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "integer", "module parameter", "no", ""

.. versionadded:: 8.2106.0

This permits to override the equally-named module parameter on the input()
level. For further details, see the module parameter.


MaxFrameSize
^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "integer", "module parameter", "no", "none"

.. versionadded:: 8.2106.0

This permits to override the equally-named module parameter on the input()
level. For further details, see the module parameter.


PreserveCase
^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "boolean", "module parameter", "no", "none"

.. versionadded:: 8.2106.0

This permits to override the equally-named module parameter on the input()
level. For further details, see the module parameter.


KeepAlive
^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "binary", "module parameter", "no", ""

.. versionadded:: 8.2106.0

This permits to override the equally-named module parameter on the input()
level. For further details, see the module parameter.


KeepAlive.Probes
^^^^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "integer", "module parameter", "no", ""

.. versionadded:: 8.2106.0

This permits to override the equally-named module parameter on the input()
level. For further details, see the module parameter.


KeepAlive.Time
^^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "integer", "module parameter", "no", ""

.. versionadded:: 8.2106.0

This permits to override the equally-named module parameter on the input()
level. For further details, see the module parameter.


KeepAlive.Interval
^^^^^^^^^^^^^^^^^^

.. csv-table::
   :header: "type", "default", "mandatory", "|FmtObsoleteName| directive"
   :widths: auto
   :class: parameter-table

   "integer", "module parameter", "no", ""

.. versionadded:: 8.2106.0

This permits to override the equally-named module parameter on the input()
level. For further details, see the module parameter.



.. _imtcp-statistic-counter:

Statistic Counter
=================

This plugin maintains :doc:`statistics <../rsyslog_statistic_counter>` for each listener. The statistic is named
after the given input name (or "imtcp" if none is configured), followed by
the listener port in parenthesis. For example, the counter for a listener
on port 514 with no set name is called "imtcp(514)".

The following properties are maintained for each listener:

-  **submitted** - total number of messages submitted for processing since startup


Caveats/Known Bugs
==================

-  module always binds to all interfaces
-  can not be loaded together with `imgssapi <imgssapi.html>`_ (which
   includes the functionality of imtcp)


Examples
========

Example 1
---------

This sets up a TCP server on port 514 and permits it to accept up to 500
connections:

.. code-block:: none

   module(load="imtcp" MaxSessions="500")
   input(type="imtcp" port="514")


Note that the global parameters (here: max sessions) need to be set when
the module is loaded. Otherwise, the parameters will not apply.


Additional Resources
====================

- `rsyslog video tutorial on how to store remote messages in a separate file <http://www.rsyslog.com/howto-store-remote-messages-in-a-separate-file/>`_ (for legacy syntax, but you get the idea).

