Networking & Sync

AirDrop-like capabilities, device mesh, and encrypted sync.

Overview

Floppy.WTF devices form a local mesh with AirDrop-like file transfer, continuous folder sync, encrypted tunnels, and automatic device discovery. All capabilities are declaratively configured in NixOS modules.

Capability Stack


┌─────────────────────────────────────────────┐
│  User Experience                             │
│  floppy send / floppy devices               │
└─────────────────────────────────────────────┘
                    │
┌─────────────────────────────────────────────┐
│  File Transfer    │  Folder Sync             │
│  LocalSend        │  Syncthing               │
│  (on-demand)      │  (continuous)            │
└─────────────────────────────────────────────┘
                    │
┌─────────────────────────────────────────────┐
│  Encrypted Transport                         │
│  WireGuard (device-to-device tunnels)        │
└─────────────────────────────────────────────┘
                    │
┌─────────────────────────────────────────────┐
│  Discovery                                   │
│  Avahi / mDNS (automatic LAN detection)      │
└─────────────────────────────────────────────┘

LocalSend — AirDrop-Like Transfer

LAN-based encrypted file transfer
Cross-platform (Linux, macOS, Windows, iOS, Android)
No account required, TLS encrypted
Automatic device discovery via mDNS


{
  environment.systemPackages = with pkgs; [ localsend ];
 
  services.avahi = {
    enable = true;
    nssmdns4 = true;
    publish = { enable = true; addresses = true; };
  };
 
  networking.firewall.allowedTCPPorts = [ 53317 ];
  networking.firewall.allowedUDPPorts = [ 53317 ];
}

CLI Shortcut


floppy send ./file.pdf
# → Discovers nearby devices
# → User selects target
# → Transfers via LocalSend protocol

Syncthing — Continuous Sync

Continuous folder synchronization between devices
Decentralized (no central server)
Block-level hashing for integrity
Conflict resolution and versioning


{
  services.syncthing = {
    enable = true;
    user = "jeremy";
    dataDir = "/home/jeremy";
    configDir = "/home/jeremy/.config/syncthing";
    overrideDevices = false;
    overrideFolders = false;
    settings.gui.theme = "dark";
  };
 
  networking.firewall.allowedTCPPorts = [ 8384 22000 ];
  networking.firewall.allowedUDPPorts = [ 22000 21027 ];
}

Default Sync Folders

Folder	Path	Purpose
Documents	`~/Documents`	General files
Projects	`~/Projects`	Code and work
Shared	`~/Shared`	Cross-device drop zone

WireGuard — Encrypted Mesh

Modern VPN tunnels between devices
Minimal overhead, kernel-level performance
Simple key management


{
  networking.wg-quick.interfaces.wg0 = {
    address = [ "10.100.0.X/24" ];
    listenPort = 51820;
    privateKeyFile = "/etc/wireguard/private.key";
    peers = [{
      publicKey = "...";
      allowedIPs = [ "10.100.0.0/24" ];
    }];
  };
 
  networking.firewall.allowedUDPPorts = [ 51820 ];
}

IP Allocation

Device	WireGuard IP
dell-dev-01	10.100.0.1
dell-dev-02	10.100.0.2
dell-lab-01	10.100.0.10

Managed via device registry metadata.

Avahi / mDNS — Device Discovery

Automatic LAN device detection with .local hostname resolution.


{
  services.avahi = {
    enable = true;
    nssmdns4 = true;
    publish = {
      enable = true;
      addresses = true;
      domain = true;
      userServices = true;
      workstation = true;
    };
  };
}

Devices discoverable as {hostname}.local:


ping dell-dev-01.local
ssh jeremy@dell-lab-01.local

Role-Based Networking

Feature	dev	node	minimal	lab	kiosk
LocalSend	Yes	No	No	Yes	No
Syncthing	Yes	No	No	Yes	No
WireGuard	Yes	Yes	No	Yes	No
Avahi/mDNS	Yes	Yes	Yes	Yes	Yes
SSH	Yes	Yes	Yes	Yes	Admin only

Security

Concern	Mitigation
WireGuard keys	Generated on device, private key never leaves
LocalSend traffic	TLS encrypted by default
Syncthing traffic	TLS + device ID verification
mDNS exposure	LAN only, no WAN advertisement
Firewall	Only required ports opened per role