This section describes the options of the default-network-drivers() source in syslog-ng OSE.

The default-network-drivers() source has the following options.

ca-dir()

Type: Directory name
Default: none

Description: The name of a directory that contains a set of trusted CA certificates in PEM format. The CA certificate files have to be named after the 32-bit hash of the subject's name. This naming can be created using the c_rehash utility in openssl. For an example, see Configuring TLS on the syslog-ng OSE clients. The syslog-ng OSE application uses the CA certificates in this directory to validate the certificate of the peer.

This option can be used together with the optional ca-file() option.

NOTE: During a TLS handshake, syslog-ng OSE automatically sets the certificate_authorities field of the certificate request based on the ca-file() and ca-dir() options.

ca-file()

Type: File name
Default: empty

Description: Optional. The name of a file that contains a set of trusted CA certificates in PEM format. The syslog-ng OSE application uses the CA certificates in this file to validate the certificate of the peer.

Example format in configuration:

ca-file("/etc/pki/tls/certs/ca-bundle.crt")

NOTE: The ca-file() option can be used together with the ca-dir() option, and it is relevant when peer-verify() is set to other than no or optional-untrusted.

NOTE: During a TLS handshake, syslog-ng OSE automatically sets the certificate_authorities field of the certificate request based on the ca-file() and ca-dir() options.

flags()

Type: assume-utf8, empty-lines, expect-hostname, kernel, no-hostname, no-multi-line, no-parse, sanitize-utf8, store-legacy-msghdr, store-raw-message, syslog-protocol, threaded, validate-utf8
Default: empty set

Description: Specifies the log parsing options of the source.

  • assume-utf8: The assume-utf8 flag assumes that the incoming messages are UTF-8 encoded, but does not verify the encoding. If you explicitly want to validate the UTF-8 encoding of the incoming message, use the validate-utf8 flag.

  • empty-lines: Use the empty-lines flag to keep the empty lines of the messages. By default, syslog-ng OSE removes empty lines automatically.

  • expect-hostname: If the expect-hostname flag is enabled, syslog-ng OSE will assume that the log message contains a hostname and parse the message accordingly. This is the default behavior for TCP sources. Note that pipe sources use the no-hostname flag by default.

  • guess-timezone: Attempt to guess the timezone of the message if this information is not available in the message. Works when the incoming message stream is close to real time, and the timezone information is missing from the timestamp.
  • ignore-aux-data: This flag enables the source to ignore auxiliary data.

  • kernel: The kernel flag makes the source default to the LOG_KERN | LOG_NOTICE priority if not specified otherwise.

  • no-header: The no-header flag triggers syslog-ng OSE to parse only the PRI field of incoming messages, and put the rest of the message contents into ${MSG}.

    Its functionality is similar to that of the no-parse flag, except the no-header flag does not skip the PRI field.

    NOTE: Essentially, the no-header flag signals syslog-ng OSE that the syslog header is not present (or does not adhere to the conventions / RFCs), so the entire message (except from the PRI field) is put into ${MSG}.

    Example: using the no-header flag with the syslog-parser() parser

    The following example illustrates using the no-header flag with the syslog-parser() parser:

      parser p_syslog {
      syslog-parser(
      flags(no-header)
      );
  };

  • no-hostname: Enable the no-hostname flag if the log message does not include the hostname of the sender host. That way syslog-ng OSE assumes that the first part of the message header is PROGRAM instead of HOST. For example:

      source s_dell {
      network(
          port(2000)
          flags(no-hostname)
      );
  };

  • no-multi-line: The no-multi-line flag disables line-breaking in the messages: the entire message is converted to a single line. Note that this happens only if the underlying transport method actually supports multi-line messages. Currently the file() and pipe() drivers support multi-line messages.

  • no-parse: By default, syslog-ng OSE parses incoming messages as syslog messages. The no-parse flag completely disables syslog message parsing and processes the complete line as the message part of a syslog message. The syslog-ng OSE application will generate a new syslog header (timestamp, host, and so on) automatically and put the entire incoming message into the MESSAGE part of the syslog message (available using the ${MESSAGE} macro). This flag is useful for parsing messages not complying to the syslog format.

    If you are using the flags(no-parse) option, then syslog message parsing is completely disabled, and the entire incoming message is treated as the ${MESSAGE} part of a syslog message. In this case, syslog-ng OSE generates a new syslog header (timestamp, host, and so on) automatically. Note that even though flags(no-parse) disables message parsing, some flags can still be used, for example, the no-multi-line flag.

  • dont-store-legacy-msghdr: By default, syslog-ng OSE stores the original incoming header of the log message. This is useful if the original format of a non-syslog-compliant message must be retained (syslog-ng OSE automatically corrects minor header errors, for example, adds a whitespace before msg in the following message: Jan 22 10:06:11 host program:msg). If you do not want to store the original header of the message, enable the dont-store-legacy-msghdr flag.

  • sanitize-utf8: When using the sanitize-utf8 flag, syslog-ng OSE converts non-UTF-8 input to an escaped form, which is valid UTF-8.

  • store-raw-message: Save the original message as received from the client in the ${RAWMSG} macro. You can forward this raw message in its original form to another syslog-ng OSE node using the syslog-ng() destination, or to a SIEM system, ensuring that the SIEM can process it. Available only in 3.16 and later.

  • syslog-protocol: The syslog-protocol flag specifies that incoming messages are expected to be formatted according to the new IETF syslog protocol standard (RFC-5424), but without the frame header. Note that this flag is not needed for the syslog driver, which handles only messages that have a frame header.

  • threaded: The threaded flag enables multithreading for the destination. For details on multithreading, see Multithreading and scaling in syslog-ng OSE.

    If a parsing or syntax error occurs, use "threaded" nested in quotation marks.

      flags(
      validate-utf8
      "threaded"
      store-raw-message
  )

    NOTE: The file destination uses multiple threads only if the destination filename contains macros.

  • validate-utf8: The validate-utf8 flag enables encoding-verification for messages formatted according to the new IETF syslog standard (for details, see IETF-syslog messages. If the BOM1 character is missing, but the message is otherwise UTF-8 compliant, syslog-ng OSE automatically adds the BOM character to the message.

log-msg-size()

Type: number (bytes)
Default: Use the global log-msg-size() option, which defaults to 65536 (64 KiB).

Description: Maximum length of an incoming message in bytes. This length includes the entire message (the data structure and individual fields). The maximal value that can be set is 268435456 bytes (256 MiB).

For messages using the IETF-syslog message format, the maximal size of the value of an SDATA field is 64 KiB.

NOTE: In most cases, log-msg-size() does not need to be set higher than 10 MiB.

For details on how encoding affects the size of the message, see Message size and encoding.

You can use human-readable units when setting configuration options. For details, see Notes about the configuration syntax.

Uses the value of the global option if not specified.

max-connections()

Type: number
Default: 10

Description: Specifies the maximum number of simultaneous connections.

Note that the total number of connections the default-network-drivers() source can use is 3*max-connections(), because this value applies to the network(tcp), syslog(tcp), and syslog(tls) connections individually.

rfc5424-tcp-port()

Type: number
Default: 601

Description: The TCP port number where the default-network-drivers() source receives RFC-5424 formatted (IETF-syslog) messages.

rfc5424-tls-port()

Type: number
Default: 6514

Description: The TCP port number where the default-network-drivers() source receives RFC-5424 formatted (IETF-syslog), TLS-encrypted messages.

CAUTION: To receive messages using a TLS-encrypted connection, you must set the tls(key-file() cert-file()) options of the default-network-drivers() source.

For example:

source s_network {
   default-network-drivers(
       tls(
           key-file("/path/to/ssl-private-key")
           cert-file("/path/to/ssl-cert")
       )
   );
};

tcp-port()

Type: number
Default: 514

Description: The TCP port number where the default-network-drivers() source receives RFC-3164 formatted (BSD-syslog) messages.

tls()

Type: tls options
Default: n/a

Description: This option sets various options related to TLS encryption, for example, key/certificate files and trusted CA locations. TLS can be used only with tcp-based transport protocols. For details, see TLS options.

udp-port()

Type: number
Default: 514

Description: The UDP port number where the default-network-drivers() source receives RFC-3164 formatted (BSD-syslog) messages

  1. The byte order mark (BOM) is a Unicode character used to signal the byte-order of the message text. ↩

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