v0.4.0

General changes

• All NAT traversal is now done over UDP. This should improve traversal success rate by avoiding TCP shenanigans, which were frequently confusing the hell out of OS network layer.
• Proxying traffic is done using native OS threads for better performance.
• Reliable traffic delivery for tcp and tls peerings is implemented using KCP protocol, as TCP traversal is gone.
• Traversal messages are encoded using STUN, the same protocol as ICE/WebRTC use, potentially helping with traversal of excessively aggressive firewalls.

New configuration options

• --reconnect or yggdrasil_admin_reconnect = true (default is false) - reconnect to admin api if yggdrasil router was restated or yet to be started.
• only_peers_advertising_jumper = true (default is false) - only consider peering with nodes that advertise jumper support, i.e. have jumper: true in NodeInfo.
• failed_yggdrasil_traversal_limit = n (default is unlimited) - avoid repeated traversal attempts, if there already were n that failed.
• yggdrasil_dpi (highly experimental) - send network traffic over an unreliable channel (improves latency under load). See Advanced configuration.

Other changes

• stun-test binary can act as a minimal STUN server when provided with --serve and optionally --port.
• Number of packets sent when attempting firewall traversal over yggdrasil is reduced.
• Exponential timeout for STUN requests.