Add SNTP/NTP Time Synchronization

[MalteJ]

Description

FeOS currently lacks automatic time synchronization. The system should regularly synchronize its time via SNTP/NTP to ensure accurate timekeeping across all operations.

Requirements

Time Synchronization Schedule

• Perform initial time synchronization at system startup
• Repeat synchronization every 24 hours thereafter

NTP Server Selection Strategy

The system should implement a priority-based approach for selecting NTP servers:

1. Primary: Query NTP server information via DHCPv6 (Option 56)

   • If the DHCP server provides NTP server information, use these servers

2. Fallback: Use public NTP pool servers

   • Default to pool.ntp.org if no DHCPv6 NTP information is available

Technical Details

• Protocol: SNTP (Simple Network Time Protocol) or NTP
• DHCPv6 Option: Option 56 (OPTION_NTP_SERVER) as defined in RFC 5908
• Default NTP pool: pool.ntp.org

Acceptance Criteria

• System performs time synchronization on boot
• System synchronizes time every 24 hours via a scheduled service/timer
• System queries DHCPv6 for NTP server information (Option 56)
• System uses DHCPv6-provided NTP servers when available
• System falls back to public NTP pool when no DHCPv6 NTP information is provided
• Time synchronization errors are logged appropriately

Implementation Considerations

• Ensure proper error handling when NTP servers are unreachable. Retry every few minutes in case of failure (e.g. network down).
• Log which NTP server source is being used (DHCPv6 vs. fallback and server address)
• Handle network availability at boot time gracefully

Related

• RFC 5908: Network Time Protocol (NTP) Server Option for DHCPv6