Fortigate parser

The Fortigate parser can parse the log messages of FortiGate/FortiOS (Fortigate Next-Generation Firewall (NGFW)). These messages do not completely comply with the syslog RFCs, making them difficult to parse. The fortigate-parser() of AxoSyslog solves this problem, and can separate these log messages to name-value pairs. For details on using value-pairs, see Structuring macros, metadata, and other value-pairs. The parser can parse messages in the following format:

   <PRI><NAME=VALUE PAIRS>

For example:

   <189>date=2021-01-15 time=12:58:59 devname="FORTI_111" devid="FG100D3G12801312" logid="0001000014" type="traffic" subtype="local" level="notice" vd="root" eventtime=1610704739683510055 tz="+0300" srcip=91.234.154.139 srcname="91.234.154.139" srcport=45295 srcintf="wan1" srcintfrole="wan" dstip=213.59.243.9 dstname="213.59.243.9" dstport=46730 dstintf="unknown0" dstintfrole="undefined" sessionid=2364413215 proto=17 action="deny" policyid=0 policytype="local-in-policy" service="udp/46730" dstcountry="Russian Federation" srccountry="Russian Federation" trandisp="noop" app="udp/46730" duration=0 sentbyte=0 rcvdbyte=0 sentpkt=0 appcat="unscanned" crscore=5 craction=262144 crlevel="low"

If you find a message that the fortigate-parser() cannot properly parse, contact us, so we can improve the parser.

By default, the Fortigate-specific fields are extracted into name-value pairs prefixed with .fortigate. For example, the devname in the previous message becomes ${.fortigate.devname}. You can change the prefix using the prefix option of the parser.

Prerequisites

Install the axosyslog-scl package on Debian/Ubuntu. On RHEL and compatible distributions, the SCL files are part of the axosyslog base package.

Your configuration must also contain @include "scl.conf", which the default configuration file already does. If the SCL files are missing, AxoSyslog fails to start with an unexpected LL_IDENTIFIER error.

@include "scl.conf"

The fortigate-parser() driver is a reusable configuration snippet (SCL). For details on using or writing such configuration snippets, see Reusing configuration blocks. You can find its source in scl/fortigate/fortigate.conf on GitHub.

Declaration:

   @version: 4.28
    @include "scl.conf"
    log {
        source { network(transport("udp") flags(no-parse)); };
        parser { fortigate-parser(); };
        destination { ... };
    };

Note that you have to disable message parsing in the source using the flags(no-parse) option for the parser to work.

prefix()

Description: Insert a prefix before the name part of the parsed name-value pairs to help further processing. For example:

• To insert the my-parsed-data. prefix, use the prefix(my-parsed-data.) option.
• To refer to a particular data that has a prefix, use the prefix in the name of the macro, for example, ${my-parsed-data.name}.
• If you forward the parsed messages using the IETF-syslog protocol, you can insert all the parsed data into the SDATA part of the message using the prefix(.SDATA.my-parsed-data.) option.

Names starting with a dot (for example, .example) are reserved for use by AxoSyslog. If you use such a macro name as the name of a parsed value, it will attempt to replace the original value of the macro (note that only soft macros can be overwritten, see Hard versus soft macros for details). To avoid such problems, use a prefix when naming the parsed values, for example, prefix(my-parsed-data.)

By default, websense-parser() uses the .websense. prefix. To modify it, use the following format:

   parser {
        websense-parser(prefix("myprefix."));
    };