policy/protocols/conn/known-services.zeek

Known

This script logs and tracks active services. For this script, an active service is defined as an IP address and port of a server for which a TCP handshake (SYN+ACK) is observed, assumed to have been done in the past (started seeing packets mid-connection, but the server is actively sending data), or sent at least one UDP packet. If a protocol name is found/known for service, that will be logged, but services whose names can’t be determined are also still logged.

Namespace:Known
Imports:base/frameworks/cluster, base/utils/directions-and-hosts.zeek

Summary

Runtime Options

Known::service_store_timeout: interval &redef The timeout interval to use for operations against Known::service_store.
Known::service_tracking: Host &redef The hosts whose services should be tracked and logged.
Known::service_udp_requires_response: bool &redef Require UDP server to respond before considering it an “active service”.

Redefinable Options

Known::service_store_expiry: interval &redef The expiry interval of new entries in Known::service_store.
Known::service_store_name: string &redef The Broker topic name to use for Known::service_store.
Known::use_service_store: bool &redef Toggles between different implementations of this script.

State Variables

Known::service_store: Cluster::StoreInfo Holds the set of all known services.
Known::services: table &create_expire = 1.0 day Tracks the set of daily-detected services for preventing the logging of duplicates, but can also be inspected by other scripts for different purposes.

Types

Known::AddrPortServTriplet: record  
Known::ServicesInfo: record The record type which contains the column fields of the known-services log.

Redefinitions

Log::ID: enum

The known-services logging stream identifier.

connection: record
New Fields:

connection

known_services_done: bool &default = F &optional

Events

Known::log_known_services: event Event that can be handled to access the Known::ServicesInfo record as it is sent on to the logging framework.

Hooks

Known::log_policy_services: Log::PolicyHook A default logging policy hook for the stream.

Detailed Interface

Runtime Options

Known::service_store_timeout
Type:interval
Attributes:&redef
Default:15.0 secs

The timeout interval to use for operations against Known::service_store.

Known::service_tracking
Type:

Host

Attributes:

&redef

Default:

LOCAL_HOSTS

Redefinition:

from policy/tuning/track-all-assets.zeek

=:

ALL_HOSTS

The hosts whose services should be tracked and logged. See Host for possible choices.

Known::service_udp_requires_response
Type:bool
Attributes:&redef
Default:T

Require UDP server to respond before considering it an “active service”.

Redefinable Options

Known::service_store_expiry
Type:interval
Attributes:&redef
Default:1.0 day

The expiry interval of new entries in Known::service_store. This also changes the interval at which services get logged.

Known::service_store_name
Type:string
Attributes:&redef
Default:"zeek/known/services"

The Broker topic name to use for Known::service_store.

Known::use_service_store
Type:bool
Attributes:&redef
Default:T

Toggles between different implementations of this script. When true, use a Broker data store, else use a regular Zeek set with keys uniformly distributed over proxy nodes in cluster operation.

State Variables

Known::service_store
Type:

Cluster::StoreInfo

Default:
{
   name=<uninitialized>
   store=<uninitialized>
   master_node=""
   master=F
   backend=Broker::MEMORY
   options=[sqlite=[path=""], rocksdb=[path=""]]
   clone_resync_interval=10.0 secs
   clone_stale_interval=5.0 mins
   clone_mutation_buffer_interval=2.0 mins
}

Holds the set of all known services. Keys in the store are Known::AddrPortServTriplet and their associated value is always the boolean value of “true”.

Known::services
Type:table [addr, port] of set [string]
Attributes:&create_expire = 1.0 day
Default:{}

Tracks the set of daily-detected services for preventing the logging of duplicates, but can also be inspected by other scripts for different purposes.

In cluster operation, this table is uniformly distributed across proxy nodes.

This table is automatically populated and shouldn’t be directly modified.

Types

Known::AddrPortServTriplet
Type:

record

host: addr

p: port

serv: string

Known::ServicesInfo
Type:

record

ts: time &log

The time at which the service was detected.

host: addr &log

The host address on which the service is running.

port_num: port &log

The port number on which the service is running.

port_proto: transport_proto &log

The transport-layer protocol which the service uses.

service: set [string] &log

A set of protocols that match the service’s connection payloads.

The record type which contains the column fields of the known-services log.

Events

Known::log_known_services
Type:event (rec: Known::ServicesInfo)

Event that can be handled to access the Known::ServicesInfo record as it is sent on to the logging framework.

Hooks

Known::log_policy_services
Type:Log::PolicyHook

A default logging policy hook for the stream.