Rules

Rules format

Rules are stored as JSON files inside the -rule-path folder, in the simplest cast a rule looks like this:

{
   "created": "2018-04-07T14:13:27.903996051+02:00",
   "updated": "2018-04-07T14:13:27.904060088+02:00",
   "name": "deny-simple-www-google-analytics-l-google-com",
   "enabled": true,
   "action": "deny",
   "duration": "always",
   "operator": {
     "type": "simple",
     "operand": "dest.host",
     "data": "www-google-analytics.l.google.com"
   }
}

Field	Description
created	UTC date and time of creation.
update	UTC date and time of the last update.
name	The name of the rule.
enabled	Use to temporarily disable and enable rules without moving their files.
action	Can be deny or allow.
duration	For rules persisting on disk, this value is default to always.
operator.type	Can be simple, in which case a simple == comparison will be performed, or regexp if the data field is a regular expression to match.
operator.operand	What element of the connection to compare, can be one of: true (will always match), process.path (the path of the executable), process.command (full command line, including path and arguments), provess.env.ENV_VAR_NAME (use the value of an environment variable of the process given its name), user.id, dest.ip, dest.host or dest.port.
operator.data	The data to compare the operand to, can be a regular expression if type is regexp.

An example with a regular expression:

{
   "created": "2018-04-07T14:13:27.903996051+02:00",
   "updated": "2018-04-07T14:13:27.904060088+02:00",
   "name": "deny-any-google-analytics",
   "enabled": true,
   "action": "deny",
   "duration": "always",
   "operator": {
     "type": "regexp",
     "operand": "dest.host",
     "data": "(?i)
   }
}

An example whitelisting a whole process:

{
   "created": "2018-04-07T15:00:48.156737519+02:00",
   "updated": "2018-04-07T15:00:48.156772601+02:00",
   "name": "allow-simple-opt-google-chrome-chrome",
   "enabled": true,
   "action": "allow",
   "duration": "always",
   "operator": {
     "type": "simple",
     "operand": "process.path",
     "data": "/opt/google/chrome/chrome"
   }
 }

Example of a complex rule using the operator list, saved from the GUI (Note: version v1.0.0-rc2):

{
  "created": "2020-02-07T14:16:20.550255152+01:00",
  "updated": "2020-02-07T14:16:20.729849966+01:00",
  "name": "deny-list-type-simple-operand-destip-data-1101-type-simple-operand-destport-data-23-type-simple-operand-userid-data-1000-type-simple-operand-processpath-data-usrbintelnetnetkit",
  "enabled": true,
  "action": "deny",
  "duration": "always",
  "operator": {
    "type": "list",
    "operand": "list",
    "data": "[{\"type\": \"simple\", \"operand\": \"dest.ip\", \"data\": \"1.1.0.1\"}, {\"type\": \"simple\", \"operand\": \"dest.port\", \"data\": \"23\"}, {\"type\": \"simple\", \"operand\": \"user.id\", \"data\": \"1000\"}, {\"type\": \"simple\", \"operand\": \"process.path\", \"data\": \"/usr/bin/telnet.netkit\"}]",
    "list": [
      {
        "type": "simple",
        "operand": "dest.ip",
        "data": "1.1.0.1",
        "list": null
      },
      {
        "type": "simple",
        "operand": "dest.port",
        "data": "23",
        "list": null
      },
      {
        "type": "simple",
        "operand": "user.id",
        "data": "1000",
        "list": null
      },
      {
        "type": "simple",
        "operand": "process.path",
        "data": "/usr/bin/telnet.netkit",
        "list": null
      }
    ]
  }
}