Network Daemon (networkd)

Overview

The Network Daemon (networkd) manages network interfaces, IP configuration, routing, and DNS for FreeWorld OS. It provides both static and DHCP-based network configuration.

TCP/IP Stack Enhancements

FreeWorld OS includes comprehensive TCP/IP stack enhancements:

TCP Congestion Control

• Algorithms: Cubic, BBR, Reno congestion control algorithms
• Adaptive Control: Automatic algorithm selection based on network conditions

TCP Fast Open

• Fast Open Support: Reduces connection establishment latency

TCP Window Scaling

• Large Windows: Support for large TCP windows (>64KB)

TCP Selective Acknowledgments (SACK)

• SACK Support: Efficient retransmission with selective ACKs

TCP Timestamps

• Timestamp Option: TCP timestamp option for RTT measurement

TCP Keepalive

• Keepalive Support: TCP keepalive for connection monitoring

UDP Enhancements

• UDP Checksum Offloading: Hardware-accelerated UDP checksums
• UDP-Lite: Partial checksum support

IP Fragmentation

• Fragmentation: IP packet fragmentation and reassembly

IP Options

• Options Processing: IP options handling

ICMP Enhancements

• Extended ICMP: Enhanced ICMP support

Network Services

FreeWorld OS includes comprehensive network services:

HTTP/HTTPS Server

• Web Server: Complete HTTP/HTTPS server implementation
• Features: HTTP/1.1, HTTPS with TLS, virtual hosts

FTP Server

• FTP Server: Complete FTP server implementation
• Features: Active/passive modes, TLS support

SSH Server

• SSH Server: Complete SSH server implementation
• Features: SSH 2.0, key-based authentication, port forwarding

NFS Server

• NFS Server: Network File System server
• Features: NFS v3/v4, RPC, mount protocol

SMB/CIFS Server

• SMB Server: Server Message Block server
• Features: SMB 2.0/2.1/3.0, authentication, file sharing

DNS Server

• DNS Server: Domain Name System server
• Features: DNS resolution, caching, forwarding

DHCP Server

• DHCP Server: Dynamic Host Configuration Protocol server
• Features: IP address assignment, lease management

NTP Client/Server

• NTP: Network Time Protocol client and server
• Features: Time synchronization, stratum management

SNMP

• SNMP: Simple Network Management Protocol
• Features: SNMP v1/v2/v3, MIB support

Features

• Interface Detection: Automatically detects network interfaces
• Static IP Configuration: Manual IP, netmask, and gateway configuration
• DHCP Support: Automatic IP configuration via DHCP (structure ready)
• DNS Configuration: DNS server configuration
• Routing Table Management: Add/delete routes (structure ready)
• Interface State Management: Bring interfaces up/down
• Connectivity Monitoring: Ping tests and statistics
• Statistics: Track bytes sent/received per interface

Network Interface Management

networkd maintains a list of network interfaces with the following information:

• Interface Name: e.g., "eth0", "wlan0"
• MAC Address: Hardware address
• IP Address: IPv4 address
• Netmask: Subnet mask
• Gateway: Default gateway
• DNS Servers: Up to 4 DNS servers
• State: Interface up/down
• DHCP: DHCP enabled/disabled
• Statistics: Bytes sent/received

IPC Interface

networkd uses Unix domain socket IPC for client communication:

• Socket Path: /var/run/networkd.sock
• Client Library: services/networkd/networkd_ipc.c
• Header: services/networkd/networkd_ipc.h

IPC Message Types

• NETWORKD_MSG_CONFIGURE_STATIC - Configure static IP
• NETWORKD_MSG_ENABLE_DHCP - Enable DHCP
• NETWORKD_MSG_SET_DNS - Set DNS servers
• NETWORKD_MSG_SET_INTERFACE_STATE - Bring interface up/down
• NETWORKD_MSG_GET_INTERFACES - Get interface list
• NETWORKD_MSG_GET_STATISTICS - Get interface statistics
• NETWORKD_MSG_ADD_ROUTE - Add route
• NETWORKD_MSG_DELETE_ROUTE - Delete route

Configuration Methods

Via IPC (Recommended)

#include "networkd_ipc.h"

// Configure static IP
networkd_configure_static("eth0", "192.168.1.100", 
                          "255.255.255.0", "192.168.1.1");

// Enable DHCP
networkd_enable_dhcp("eth0");

// Set DNS
networkd_set_dns("eth0", "8.8.8.8", "8.8.4.4");

// Bring interface up
networkd_set_interface_state("eth0", 1);

Command Line (Legacy)

networkd --static eth0 192.168.1.100 255.255.255.0 192.168.1.1
networkd --dhcp eth0

Note: Command-line arguments are processed at startup. For runtime configuration, use IPC.

Ethernet Driver

The network stack requires an Ethernet driver for low-level frame handling:

• Location: kernel/drivers/ethernet.asm
• Features:
  • Ethernet frame transmission
  • Ethernet frame reception
  • MAC address management
  • Frame statistics

Status: ✅ Core structure complete, needs hardware-specific implementation

Network Stack

The kernel provides a basic network stack foundation:

• Location: kernel/network/network_stack.asm
• Purpose: Low-level network protocol handling
• Integration: Works with Ethernet driver