Using xinetd (Extended Internet Service Daemon) on Linux is not deprecated, but its usage and relevance have evolved over time. Xinetd is an open-source super-server daemon that runs on many Unix-like systems, managing Internet-based connectivity. It is a more secure and feature-rich alternative to the older inetd ("Internet daemon"), which has been deprecated by most modern Linux distributions (source).
Xinetd offers enhanced features compared to inetd, such as extensive logging capabilities, access control mechanisms like TCP Wrapper ACLs, and the ability to manage services based on time and resource limits. It allows for more flexibility in configuring services, as changes can be made by simply modifying a configuration file rather than restarting the entire server. This ease of management makes xinetd a preferred choice for handling multiple services.
Security-wise, xinetd is considered a secure daemon. It provides access control for both TCP and UDP connections, enabling limitations based on source IP addresses, usernames, time of day, and other criteria. Xinetd can also be configured to run services under dedicated user or group privileges, minimizing potential security risks. Moreover, it supports logging all incoming connection requests, which is crucial for detecting and alerting administrators about suspicious activities.
In terms of configuration, xinetd's settings reside in the /etc/xinetd.conf file, and service-specific configurations are stored in the /etc/xinetd.d directory. This structure allows for granular control over the services managed by xinetd. For instance, services can be enabled or disabled with simple configuration changes, without the need for a full daemon restart.
It's important to note that while xinetd is not deprecated, the landscape of Linux service management has evolved with the introduction of newer tools like systemd, which is now the default initialization system and service manager for many Linux distributions. Systemd provides its own mechanisms for service management, which some may find more integrated and modern compared to xinetd. However, xinetd still remains a viable and secure option, especially for specific use cases where its unique features are advantageous.
In conclusion, while xinetd is not deprecated, its role and usage in modern Linux environments may be overshadowed by newer technologies like systemd. Nevertheless, xinetd remains a robust and secure option for managing internet-based services on Unix-like systems.