Usrlibfirewalldservices

Usrlibfirewalldservices refers to the directory that stores the default service definitions used by firewalld, the dynamic firewall manager used on many Linux distributions. In most systems this is mounted as /usr/lib/firewalld/services and contains a collection of XML files that describe individual services by name. These service definitions allow administrators to enable or disable access to a service by referencing its name rather than listing ports directly in commands.

The files in this directory are XML documents that define a named service, including a short name, a description, and one or more port entries. Each port entry specifies a port number and a protocol, typically tcp or udp. For example, a file for http would define port 80 with the tcp protocol, while https would define port 443 with tcp. The collection covers common services like SSH, HTTP, HTTPS, and various application protocols, providing a standardized set of service names that can be used in zone configurations.

Usage and administration: Firewalld uses these service definitions to map service names to the required ports when constructing firewall rules. Administrators can add a service to a zone with a command such as --add-service=http, which references the corresponding entry in the service files. To customize or extend the set, users can copy a default file to /etc/firewalld/services and modify or create new definitions there; files in /etc/firewalld/services take precedence over the defaults and persist across package updates.

Notes: Some distributions also install service definitions in /usr/share/firewalld/services. The exact location may vary, but the concept remains the same: a standardized, XML-based catalog of services used by firewalld to simplify rule management.