Files
fips/docs/design/fips-configuration.md
OceanSlim 774e33fd27 Add Windows platform support (#45)
Gate platform-specific code behind cfg attributes and add full Windows
  support: TUN device via wintun, TCP control socket on localhost:21210,
  Windows Service lifecycle (--install-service/--uninstall-service/--service),
  CI build and test matrix, and packaging with ZIP builder and PowerShell
  service management scripts.

  Key changes:

  - Cargo.toml: move tun/libc/rtnetlink behind cfg(unix); add wintun and
    windows-service dependencies for Windows
  - upper/tun.rs: wintun-based TUN implementation with netsh configuration
    for IPv6 address, MTU, and fd00::/8 routing
  - control/mod.rs: split into unix_impl/windows_impl; Windows uses TCP on
    localhost:21210 with shared connection handler
  - bin/fips.rs: refactor main() into run_daemon() accepting a shutdown
    signal; add Windows Service support via windows-service crate
  - transport/udp/socket.rs: platform-gated modules; Windows uses
    tokio::net::UdpSocket (kernel drop count unavailable, returns 0)
  - transport/ethernet: gate to cfg(unix); add Windows stub types
  - config: platform-conditional default paths (socket, hosts) for Windows
  - CI: add windows-latest to build matrix and test-windows job with
    cargo-nextest
  - packaging/windows: build-zip.ps1, install-service.ps1,
    uninstall-service.ps1, and package-windows.yml workflow
  - README/docs: Windows build instructions, service management, and
    control socket platform differences

  Linux and macOS behavior is unchanged.
2026-04-11 18:31:48 +01:00

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# FIPS Configuration
FIPS uses YAML-based configuration with a cascading multi-file priority system.
All parameters have sensible defaults; a node can run with no configuration file
at all (it will generate an ephemeral identity and listen on default addresses).
## Configuration Loading
### Search Paths
When started without the `-c` flag, FIPS searches for `fips.yaml` in these
locations, lowest to highest priority:
| Priority | Path | Purpose |
|----------|------|---------|
| 1 (lowest) | `/etc/fips/fips.yaml` | System-wide defaults |
| 2 | `~/.config/fips/fips.yaml` | User preferences |
| 3 | `~/.fips.yaml` | Legacy user config |
| 4 (highest) | `./fips.yaml` | Deployment-specific overrides |
All found files are loaded and merged in priority order. Values from higher
priority files override those from lower priority files. This allows a system
administrator to set site-wide defaults in `/etc/fips/fips.yaml` while
individual deployments override specific values in `./fips.yaml`.
### CLI Option
```text
fips -c /path/to/config.yaml
```
When `-c` is specified, only that file is loaded (search paths are skipped).
### Partial Configuration
Every field has a built-in default. A configuration file only needs to specify
values that differ from defaults. For example, a minimal config might contain
only the identity and peer list, inheriting all other defaults.
## YAML Structure
The configuration is organized into five top-level sections:
```yaml
node: # Node behavior, protocol parameters, and tuning
tun: # TUN virtual interface
dns: # DNS responder for .fips domain
transports: # Network transports (UDP, Ethernet, Bluetooth, Tor, ...)
peers: # Static peer list
```
### Control Socket (`node.control.*`)
| Parameter | Type | Default | Description |
|-----------|------|---------|-------------|
| `node.control.enabled` | bool | `true` | Enable the control socket |
| `node.control.socket_path` | string | *(auto)* | **Linux:** Socket file path. Default: `$XDG_RUNTIME_DIR/fips/control.sock`, then `/run/fips/control.sock` (if root), then `/tmp/fips-control.sock`. **Windows:** TCP port number (default: `21210`); the control socket listens on `localhost` at this port. |
The control socket provides access to node state and runtime management
via the `fipsctl` command-line tool. In addition to read-only status
queries, `fipsctl connect` and `fipsctl disconnect` enable runtime peer
management. See the project [README](../../README.md#inspect) for the
command list.
On Linux, the control socket is a Unix domain socket with filesystem
permissions (mode 0770, group `fips`). On Windows, it is a TCP listener
on localhost. TCP does not provide filesystem-level ACLs, so any local
user can connect to the control port.
> **Security note (Windows):** The TCP control socket on Windows is a
> known limitation. Any process running on the local machine can connect
> to the control port and issue commands, including `disconnect`,
> `connect`, and `inject-config`. This is acceptable for single-user
> workstations but may be inappropriate for shared machines. Future
> improvements may include named pipe support (with Windows ACLs) or an
> authentication token mechanism. On shared Windows systems, consider
> using firewall rules to restrict access to the control port.
All tunable protocol parameters live under `node.*`, organized as sysctl-style
dotted paths. The top-level sections (`tun`, `dns`, `transports`, `peers`)
handle infrastructure concerns only.
## Node Parameters (`node.*`)
### Identity (`node.identity.*`)
| Parameter | Type | Default | Description |
|-----------|------|---------|-------------|
| `node.identity.nsec` | string | *(none)* | Secret key in nsec (bech32) or hex format. If omitted, behavior depends on `persistent`. |
| `node.identity.persistent` | bool | `false` | Persist identity across restarts via key file. |
Identity resolution follows a three-tier priority:
1. **Explicit `nsec`** in config — always used when present, regardless of `persistent`
2. **Persistent key file** — when `persistent: true` and no `nsec`, loads from `fips.key`
adjacent to the config file; if no key file exists, generates a new keypair and saves it
3. **Ephemeral** — when `persistent: false` (default) and no `nsec`, generates a fresh
keypair on each start
Key files (`fips.key` with mode 0600, `fips.pub` with mode 0644) are written adjacent
to the highest-priority config file for operator visibility, even in ephemeral mode.
### General
| Parameter | Type | Default | Description |
|-----------|------|---------|-------------|
| `node.leaf_only` | bool | `false` | Leaf-only mode: node does not forward traffic or participate in routing |
| `node.tick_interval_secs` | u64 | `1` | Periodic maintenance tick interval (retry checks, timeout cleanup, tree refresh) |
| `node.base_rtt_ms` | u64 | `100` | Initial RTT estimate for new links before measurements converge |
| `node.heartbeat_interval_secs` | u64 | `10` | Heartbeat send interval per peer for liveness detection |
| `node.link_dead_timeout_secs` | u64 | `30` | No-traffic timeout before a peer is declared dead and removed |
### Resource Limits (`node.limits.*`)
Controls capacity for connections, peers, and links.
| Parameter | Type | Default | Description |
|-----------|------|---------|-------------|
| `node.limits.max_connections` | usize | `256` | Max handshake-phase connections |
| `node.limits.max_peers` | usize | `128` | Max authenticated peers |
| `node.limits.max_links` | usize | `256` | Max active links |
| `node.limits.max_pending_inbound` | usize | `1000` | Max pending inbound handshakes |
### Rate Limiting (`node.rate_limit.*`)
Handshake rate limiting protects against DoS on the Noise IK handshake path.
| Parameter | Type | Default | Description |
|-----------|------|---------|-------------|
| `node.rate_limit.handshake_burst` | u32 | `100` | Token bucket burst capacity |
| `node.rate_limit.handshake_rate` | f64 | `10.0` | Tokens per second refill rate |
| `node.rate_limit.handshake_timeout_secs` | u64 | `30` | Stale handshake cleanup timeout |
| `node.rate_limit.handshake_resend_interval_ms` | u64 | `1000` | Initial handshake message resend interval |
| `node.rate_limit.handshake_resend_backoff` | f64 | `2.0` | Resend backoff multiplier (1s, 2s, 4s, 8s, 16s with defaults) |
| `node.rate_limit.handshake_max_resends` | u32 | `5` | Max resends per handshake attempt |
### Retry / Backoff (`node.retry.*`)
Connection retry with exponential backoff.
| Parameter | Type | Default | Description |
|-----------|------|---------|-------------|
| `node.retry.max_retries` | u32 | `5` | Max connection retry attempts |
| `node.retry.base_interval_secs` | u64 | `5` | Base backoff interval |
| `node.retry.max_backoff_secs` | u64 | `300` | Cap on exponential backoff (5 minutes) |
Auto-reconnect (triggered by MMP link-dead removal) uses the same backoff
parameters but bypasses `max_retries`, retrying indefinitely. See
`peers[].auto_reconnect` below.
### Cache Parameters (`node.cache.*`)
Controls caching of tree coordinates and identity mappings.
| Parameter | Type | Default | Description |
|-----------|------|---------|-------------|
| `node.cache.coord_size` | usize | `50000` | Max entries in coordinate cache |
| `node.cache.coord_ttl_secs` | u64 | `300` | Coordinate cache entry TTL (5 minutes) |
| `node.cache.identity_size` | usize | `10000` | Max entries in identity cache (LRU, no TTL) |
### Discovery Protocol (`node.discovery.*`)
Controls bloom-guided node discovery (LookupRequest/LookupResponse).
| Parameter | Type | Default | Description |
|-----------|------|---------|-------------|
| `node.discovery.ttl` | u8 | `64` | Hop limit for LookupRequest forwarding |
| `node.discovery.timeout_secs` | u64 | `10` | Lookup completion timeout |
| `node.discovery.recent_expiry_secs` | u64 | `10` | Dedup cache expiry for recent request IDs |
| `node.discovery.retry_interval_secs` | u64 | `5` | Retry interval within the timeout window; after this interval without a response, resend the lookup |
| `node.discovery.max_attempts` | u8 | `2` | Max attempts per lookup (1 = no retry, 2 = one retry) |
| `node.discovery.backoff_base_secs` | u64 | `30` | Base for exponential backoff after lookup failure; doubles per consecutive failure |
| `node.discovery.backoff_max_secs` | u64 | `300` | Cap on exponential backoff (5 minutes) |
| `node.discovery.forward_min_interval_secs` | u64 | `2` | Transit-side rate limiting: minimum interval between forwarded lookups for the same target |
### Spanning Tree (`node.tree.*`)
Controls tree construction and parent selection.
| Parameter | Type | Default | Description |
|----------------------------------------|-------|---------|--------------------------------------------------|
| `node.tree.announce_min_interval_ms` | u64 | `500` | Per-peer TreeAnnounce rate limit |
| `node.tree.parent_hysteresis` | f64 | `0.2` | Cost improvement fraction required for same-root parent switch (0.01.0) |
| `node.tree.hold_down_secs` | u64 | `30` | Suppress non-mandatory re-evaluation after parent switch |
| `node.tree.reeval_interval_secs` | u64 | `60` | Periodic cost-based parent re-evaluation interval (0 = disabled) |
| `node.tree.flap_threshold` | u32 | `4` | Parent switches in window before dampening engages |
| `node.tree.flap_window_secs` | u64 | `60` | Sliding window for counting parent switches |
| `node.tree.flap_dampening_secs` | u64 | `120` | Extended hold-down duration when flap threshold exceeded |
### Bloom Filter (`node.bloom.*`)
| Parameter | Type | Default | Description |
|-----------|------|---------|-------------|
| `node.bloom.update_debounce_ms` | u64 | `500` | Debounce interval for filter update propagation |
Bloom filter size (1 KB), hash count (5), and size classes are protocol
constants and not configurable.
### ECN Signaling (`node.ecn.*`)
Controls hop-by-hop ECN (Explicit Congestion Notification) signaling. When
enabled, transit nodes detect congestion on outgoing links (via MMP loss/ETX
metrics or kernel buffer drops) and set the CE flag on forwarded FMP frames.
Destination nodes mark ECN-capable IPv6 packets with CE before TUN delivery
per RFC 3168, enabling end-host TCP congestion control to react.
| Parameter | Type | Default | Description |
|-----------|------|---------|-------------|
| `node.ecn.enabled` | bool | `true` | Enable ECN congestion signaling (CE flag relay and local congestion detection) |
| `node.ecn.loss_threshold` | f64 | `0.05` | MMP loss rate threshold for CE marking (0.01.0). When the outgoing link's loss rate meets or exceeds this value, forwarded packets are CE-marked. |
| `node.ecn.etx_threshold` | f64 | `3.0` | MMP ETX threshold for CE marking (≥1.0). When the outgoing link's ETX meets or exceeds this value, forwarded packets are CE-marked. |
Congestion detection triggers on any of: outgoing link loss ≥ `loss_threshold`,
outgoing link ETX ≥ `etx_threshold`, or kernel receive buffer drops detected on
any local transport. CE is relayed hop-by-hop: once set on any hop, the flag
stays set for all subsequent hops to the destination.
### Rekey (`node.rekey.*`)
Controls periodic Noise rekey for forward secrecy. When enabled, both FMP
(link-layer IK) and FSP (session-layer XK) sessions perform fresh Diffie-Hellman
key exchanges after a time or message count threshold, whichever comes first.
A 10-second drain window keeps the old session active for decryption during
cutover.
| Parameter | Type | Default | Description |
|-----------|------|---------|-------------|
| `node.rekey.enabled` | bool | `true` | Enable periodic Noise rekey on all links and sessions |
| `node.rekey.after_secs` | u64 | `120` | Initiate rekey after this many seconds on a session |
| `node.rekey.after_messages` | u64 | `65536` | Initiate rekey after this many messages sent on a session |
### Session / Data Plane (`node.session.*`)
Controls end-to-end session behavior and packet queuing.
| Parameter | Type | Default | Description |
|-----------|------|---------|-------------|
| `node.session.default_ttl` | u8 | `64` | Default SessionDatagram TTL |
| `node.session.pending_packets_per_dest` | usize | `16` | Queue depth per destination during session establishment |
| `node.session.pending_max_destinations` | usize | `256` | Max destinations with pending packets |
| `node.session.idle_timeout_secs` | u64 | `90` | Idle session timeout; established sessions with no application data for this duration are removed. MMP reports (SenderReport, ReceiverReport, PathMtuNotification) do not count as activity |
| `node.session.coords_warmup_packets` | u8 | `5` | Number of initial data packets per session that include the CP flag for transit cache warmup; also the reset count on CoordsRequired/PathBroken receipt |
| `node.session.coords_response_interval_ms` | u64 | `2000` | Minimum interval (ms) between standalone CoordsWarmup responses to CoordsRequired/PathBroken signals per destination |
The anti-replay window size (2048 packets) is a compile-time constant and not
configurable.
### Link-Layer MMP (`node.mmp.*`)
Metrics Measurement Protocol for per-peer link measurement. See
[fips-mesh-layer.md](fips-mesh-layer.md) for behavioral details.
| Parameter | Type | Default | Description |
|-----------|------|---------|-------------|
| `node.mmp.mode` | string | `"full"` | Operating mode: `full` (sender + receiver reports), `lightweight` (receiver reports only), or `minimal` (spin bit + CE echo only, no reports) |
| `node.mmp.log_interval_secs` | u64 | `30` | Periodic operator log interval for link metrics |
| `node.mmp.owd_window_size` | usize | `32` | One-way delay trend ring buffer size |
### Session-Layer MMP (`node.session_mmp.*`)
Metrics Measurement Protocol for end-to-end session measurement. Configured
independently from link-layer MMP because session reports are routed through
every transit link, consuming bandwidth proportional to path length.
| Parameter | Type | Default | Description |
|-----------|------|---------|-------------|
| `node.session_mmp.mode` | string | `"full"` | Operating mode: `full`, `lightweight`, or `minimal` |
| `node.session_mmp.log_interval_secs` | u64 | `30` | Periodic operator log interval for session metrics |
| `node.session_mmp.owd_window_size` | usize | `32` | One-way delay trend ring buffer size |
### Internal Buffers (`node.buffers.*`)
Channel sizes affecting throughput and memory. Primarily useful for performance
tuning under high load or on memory-constrained devices.
| Parameter | Type | Default | Description |
|-----------|------|---------|-------------|
| `node.buffers.packet_channel` | usize | `1024` | Transport to Node packet channel capacity |
| `node.buffers.tun_channel` | usize | `1024` | TUN to Node outbound channel capacity |
| `node.buffers.dns_channel` | usize | `64` | DNS to Node identity channel capacity |
## TUN Interface (`tun.*`)
| Parameter | Type | Default | Description |
|-----------|------|---------|-------------|
| `tun.enabled` | bool | `false` | Enable TUN virtual interface |
| `tun.name` | string | `"fips0"` | Interface name |
| `tun.mtu` | u16 | `1280` | Interface MTU (IPv6 minimum) |
## DNS Responder (`dns.*`)
Resolves `<npub>.fips` queries to FIPS IPv6 addresses. Resolution is pure
computation (npub to public key to address); resolved identities are registered
with the node for routing.
| Parameter | Type | Default | Description |
|-----------|------|---------|-------------|
| `dns.enabled` | bool | `true` | Enable DNS responder |
| `dns.bind_addr` | string | `"127.0.0.1"` | Bind address |
| `dns.port` | u16 | `5354` | Listen port |
| `dns.ttl` | u32 | `300` | AAAA record TTL in seconds |
The `dns.ttl` value should not exceed `node.cache.coord_ttl_secs` to avoid
stale address mappings.
### Host Mapping
The DNS resolver checks a host map before falling back to direct npub
resolution, enabling names like `gateway.fips` instead of `npub1...fips`.
The host map is populated from two sources:
1. **Peer aliases** — the `alias` field on configured peers in `peers:`.
2. **Hosts file**`/etc/fips/hosts`, one `hostname npub1...` per line.
Blank lines and `#` comments are allowed.
The hosts file is auto-reloaded on modification (mtime change) without
restarting the daemon. Hostnames are case-insensitive.
## Transports (`transports.*`)
### UDP (`transports.udp.*`)
| Parameter | Type | Default | Description |
|-----------|------|---------|-------------|
| `transports.udp.bind_addr` | string | `"0.0.0.0:2121"` | UDP bind address and port |
| `transports.udp.mtu` | u16 | `1280` | Transport MTU |
| `transports.udp.recv_buf_size` | usize | `2097152` | UDP socket receive buffer size in bytes (2 MB). Linux kernel doubles the requested value internally. Host `net.core.rmem_max` must be >= this value. |
| `transports.udp.send_buf_size` | usize | `2097152` | UDP socket send buffer size in bytes (2 MB). Host `net.core.wmem_max` must be >= this value. |
### Ethernet (`transports.ethernet.*`)
Ethernet transport sends raw frames via AF_PACKET SOCK_DGRAM sockets.
Requires `CAP_NET_RAW` or running as root. Linux only.
| Parameter | Type | Default | Description |
|-----------|------|---------|-------------|
| `interface` | string | *(required)* | Network interface name (e.g., `"eth0"`, `"enp3s0"`) |
| `ethertype` | u16 | `0x2121` | EtherType |
| `mtu` | u16 | *(auto)* | Override MTU. Default: interface MTU minus 3 (for frame type + length prefix) |
| `recv_buf_size` | usize | `2097152` | Socket receive buffer size in bytes (2 MB) |
| `send_buf_size` | usize | `2097152` | Socket send buffer size in bytes (2 MB) |
| `discovery` | bool | `true` | Listen for discovery beacons from other nodes |
| `announce` | bool | `false` | Broadcast announcement beacons on the LAN |
| `auto_connect` | bool | `false` | Auto-connect to discovered peers |
| `accept_connections` | bool | `false` | Accept incoming connection attempts from discovered peers |
| `beacon_interval_secs` | u64 | `30` | Announcement beacon interval in seconds (minimum 10) |
**Named instances.** Multiple Ethernet interfaces can be configured by
using named sub-keys instead of flat parameters:
```yaml
transports:
ethernet:
lan:
interface: "eth0"
discovery: true
announce: true
backbone:
interface: "eth1"
announce: false
```
Each named instance operates independently with its own socket and
discovery state. The instance name is used in log messages and the
`name()` method on the Transport trait.
### TCP (`transports.tcp.*`)
TCP transport enables firewall traversal on networks that block UDP but
allow TCP (e.g., port 443). Uses FMP header-based framing with zero
overhead.
| Parameter | Type | Default | Description |
|-----------|------|---------|-------------|
| `transports.tcp.bind_addr` | string | *(none)* | Listen address (e.g., `"0.0.0.0:8443"`). If omitted, outbound-only mode. |
| `transports.tcp.mtu` | u16 | `1400` | Default MTU. Per-connection MTU derived from `TCP_MAXSEG` when available. |
| `transports.tcp.connect_timeout_ms` | u64 | `5000` | Outbound connect timeout in milliseconds |
| `transports.tcp.nodelay` | bool | `true` | `TCP_NODELAY` (disable Nagle for low latency) |
| `transports.tcp.keepalive_secs` | u64 | `30` | TCP keepalive interval in seconds (0 = disabled) |
| `transports.tcp.recv_buf_size` | usize | `2097152` | Socket receive buffer size in bytes (2 MB) |
| `transports.tcp.send_buf_size` | usize | `2097152` | Socket send buffer size in bytes (2 MB) |
| `transports.tcp.max_inbound_connections` | usize | `256` | Maximum simultaneous inbound connections |
**Named instances.** Like other transports, multiple TCP instances can
be configured with named sub-keys:
```yaml
transports:
tcp:
public:
bind_addr: "0.0.0.0:443"
internal:
bind_addr: "10.0.0.1:8443"
max_inbound_connections: 64
```
### Tor (`transports.tor.*`)
Tor transport routes FIPS traffic through the Tor network for anonymity.
Requires an external Tor daemon providing a SOCKS5 proxy. Three modes:
`socks5` for outbound-only, `control_port` for outbound + monitoring,
`directory` for outbound + inbound via Tor-managed onion service.
| Parameter | Type | Default | Description |
|-----------|------|---------|-------------|
| `transports.tor.mode` | string | `"socks5"` | Tor access mode: `socks5` (outbound only), `control_port` (outbound + monitoring), or `directory` (outbound + inbound onion service) |
| `transports.tor.socks5_addr` | string | `"127.0.0.1:9050"` | SOCKS5 proxy address (host:port) |
| `transports.tor.connect_timeout_ms` | u64 | `120000` | Connect timeout in milliseconds. Tor circuits take 1060s. |
| `transports.tor.mtu` | u16 | `1400` | Default MTU |
| `transports.tor.control_addr` | string | `"/run/tor/control"` | Tor control port address: Unix socket path or host:port. Used in `control_port` mode; optional in `directory` mode for monitoring. |
| `transports.tor.control_auth` | string | `"cookie"` | Control port authentication: `"cookie"`, `"cookie:/path/to/cookie"`, or `"password:<secret>"`. |
| `transports.tor.cookie_path` | string | `"/var/run/tor/control.authcookie"` | Path to Tor control cookie file. Used when `control_auth` is `"cookie"`. |
| `transports.tor.max_inbound_connections` | usize | `64` | Maximum inbound connections via onion service. |
| `transports.tor.directory_service.hostname_file` | string | `"/var/lib/tor/fips_onion_service/hostname"` | Path to Tor-managed hostname file containing the `.onion` address. |
| `transports.tor.directory_service.bind_addr` | string | `"127.0.0.1:8443"` | Local bind address for the listener that Tor forwards inbound connections to. Must match `HiddenServicePort` target in `torrc`. |
**Named instances.** Like other transports, multiple Tor instances can
be configured with named sub-keys for different SOCKS5 proxy endpoints.
**Directory mode** (recommended for production). Tor manages the onion
service via `HiddenServiceDir` in `torrc`. FIPS reads the `.onion`
address from the hostname file and binds a local TCP listener. This
enables Tor's `Sandbox 1` (seccomp-bpf). If `control_addr` is also
set, the transport connects to the control port for daemon monitoring
(non-fatal on failure).
**Control port mode.** Connects to the Tor daemon's control port for
monitoring only (bootstrap status, circuit health, traffic stats).
No inbound connections. Both `control_addr` and `control_auth` are
required.
### UDP + Tor Bridge Example
A node bridging clearnet (UDP) and anonymous (Tor) portions of the mesh:
```yaml
node:
identity:
persistent: true
tun:
enabled: true
transports:
udp:
bind_addr: "0.0.0.0:2121"
mtu: 1472
tor:
socks5_addr: "127.0.0.1:9050"
peers:
- npub: "npub1abc..."
alias: "clearnet-peer"
addresses:
- transport: udp
addr: "203.0.113.5:2121"
- npub: "npub1def..."
alias: "anonymous-peer"
addresses:
- transport: tor
addr: "abc123...xyz.onion:2121"
```
### Tor Directory Mode Example
A node accepting inbound connections via Tor-managed onion service
(recommended for production — enables Sandbox 1):
```yaml
node:
identity:
persistent: true
tun:
enabled: true
transports:
tor:
mode: "directory"
socks5_addr: "127.0.0.1:9050"
control_addr: "/run/tor/control" # optional, for monitoring
control_auth: "cookie"
directory_service:
hostname_file: "/var/lib/tor/fips/hostname"
bind_addr: "127.0.0.1:8444"
peers:
- npub: "npub1abc..."
alias: "tor-peer"
addresses:
- transport: tor
addr: "abcdef...xyz.onion:8443"
```
Requires a corresponding `torrc`:
```text
HiddenServiceDir /var/lib/tor/fips
HiddenServicePort 8443 127.0.0.1:8444
```
### BLE (`transports.ble.*`)
Bluetooth Low Energy transport using L2CAP Connection-Oriented Channels.
Requires BlueZ and the `ble` Cargo feature flag (default-on). Linux only;
guarded by `#[cfg(target_os = "linux")]`. Communicates with BlueZ via D-Bus
using the `bluer` crate.
| Parameter | Type | Default | Description |
|-----------|------|---------|-------------|
| `transports.ble.adapter` | string | `"hci0"` | HCI adapter name |
| `transports.ble.psm` | u16 | `0x0085` (133) | L2CAP Protocol/Service Multiplexer |
| `transports.ble.mtu` | u16 | `2048` | Default MTU. Actual MTU is negotiated per-link during L2CAP connection setup. |
| `transports.ble.max_connections` | usize | `7` | Maximum concurrent BLE connections |
| `transports.ble.connect_timeout_ms` | u64 | `10000` | Outbound connect timeout in milliseconds |
| `transports.ble.advertise` | bool | `true` | Broadcast BLE beacon advertisements for peer discovery |
| `transports.ble.scan` | bool | `true` | Listen for BLE beacon advertisements from other nodes |
| `transports.ble.auto_connect` | bool | `false` | Automatically connect to discovered peers |
| `transports.ble.accept_connections` | bool | `true` | Accept incoming L2CAP connections |
| `transports.ble.probe_cooldown_secs` | u64 | `30` | Cooldown before re-probing the same BLE address |
**Address format.** BLE peer addresses use the form
`"adapter/device_address"` — for example, `"hci0/AA:BB:CC:DD:EE:FF"`.
**Advertising and scanning.** When `advertise` is enabled, the transport
advertises the FIPS service UUID continuously so that nearby nodes can
discover and connect via L2CAP. When `scan` is enabled, the transport
continuously scans for other FIPS nodes' advertisements. Discovered
peers are probed immediately (L2CAP connect + pubkey exchange) with a
cooldown (`probe_cooldown_secs`) to prevent rapid re-probing of the same
address. If two nodes probe each other at the same time (cross-probe),
a deterministic tie-breaker based on NodeAddr comparison ensures only
one connection is established.
**Connection pool.** The `max_connections` parameter limits the number of
concurrent BLE connections. When the pool is full, the least-recently-used
connection is evicted to make room for new connections.
### BLE Example
A node using BLE for local mesh discovery alongside UDP for internet peers:
```yaml
node:
identity:
persistent: true
tun:
enabled: true
transports:
udp:
bind_addr: "0.0.0.0:2121"
ble:
adapter: "hci0"
advertise: true
scan: true
auto_connect: true
accept_connections: true
peers:
- npub: "npub1abc..."
alias: "internet-peer"
addresses:
- transport: udp
addr: "203.0.113.5:2121"
connect_policy: auto_connect
```
BLE peers on the local radio range are discovered automatically via
beacons — no static peer entries needed. Internet peers still require
explicit configuration.
## Peers (`peers[]`)
Static peer list. Each entry defines a peer to connect to.
| Parameter | Type | Default | Description |
|-----------|------|---------|-------------|
| `peers[].npub` | string | *(required)* | Peer's Nostr public key (npub-encoded) |
| `peers[].alias` | string | *(none)* | Human-readable name for logging |
| `peers[].addresses[].transport` | string | *(required)* | Transport type: `udp`, `tcp`, `ethernet`, `tor`, or `ble` |
| `peers[].addresses[].addr` | string | *(required)* | Transport address. UDP/TCP: `"host:port"` (IP or DNS hostname). Ethernet: `"interface/mac"` (e.g., `"eth0/aa:bb:cc:dd:ee:ff"`). BLE: `"adapter/device_address"` (e.g., `"hci0/AA:BB:CC:DD:EE:FF"`). Tor: `".onion:port"` or `"host:port"` |
| `peers[].addresses[].priority` | u8 | `100` | Address priority (lower = preferred) |
| `peers[].connect_policy` | string | `"auto_connect"` | Connection policy: `auto_connect`, `on_demand`, or `manual` |
| `peers[].auto_reconnect` | bool | `true` | Automatically reconnect after MMP link-dead removal (exponential backoff, unlimited retries) |
## Minimal Example
A typical node configuration enabling TUN, DNS, and a single peer:
```yaml
node:
identity:
nsec: "0102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f20"
tun:
enabled: true
name: fips0
mtu: 1280
dns:
enabled: true
bind_addr: "127.0.0.1"
port: 53
transports:
udp:
bind_addr: "0.0.0.0:2121"
mtu: 1472
peers:
- npub: "npub1tdwa4vjrjl33pcjdpf2t4p027nl86xrx24g4d3avg4vwvayr3g8qhd84le"
alias: "node-b"
addresses:
- transport: udp
addr: "172.20.0.11:2121"
connect_policy: auto_connect
```
### Mixed UDP + Ethernet Example
A node bridging internet peers (UDP) and a local Ethernet segment with
beacon discovery:
```yaml
node:
identity:
nsec: "0102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f20"
tun:
enabled: true
transports:
udp:
bind_addr: "0.0.0.0:2121"
mtu: 1472
ethernet:
interface: "eth0"
discovery: true
announce: true
auto_connect: true
accept_connections: true
peers:
- npub: "npub1tdwa4vjrjl33pcjdpf2t4p027nl86xrx24g4d3avg4vwvayr3g8qhd84le"
alias: "internet-peer"
addresses:
- transport: udp
addr: "203.0.113.5:2121"
connect_policy: auto_connect
```
Ethernet peers on the local segment are discovered automatically via
beacons — no static peer entries needed. Internet peers still require
explicit configuration.
All `node.*` parameters use their defaults. To override specific values, add
only the relevant sections:
```yaml
node:
identity:
nsec: "..."
limits:
max_peers: 64
retry:
max_retries: 10
max_backoff_secs: 600
cache:
coord_size: 100000
```
## Complete Reference
The full YAML structure with all defaults:
```yaml
node:
identity:
nsec: null # secret key in nsec or hex (null = depends on persistent)
persistent: false # true = load/save fips.key; false = ephemeral each start
leaf_only: false
tick_interval_secs: 1
base_rtt_ms: 100
heartbeat_interval_secs: 10
link_dead_timeout_secs: 30
limits:
max_connections: 256
max_peers: 128
max_links: 256
max_pending_inbound: 1000
rate_limit:
handshake_burst: 100
handshake_rate: 10.0
handshake_timeout_secs: 30
handshake_resend_interval_ms: 1000
handshake_resend_backoff: 2.0
handshake_max_resends: 5
retry:
max_retries: 5
base_interval_secs: 5
max_backoff_secs: 300
cache:
coord_size: 50000
coord_ttl_secs: 300
identity_size: 10000
discovery:
ttl: 64
timeout_secs: 10
recent_expiry_secs: 10
retry_interval_secs: 5
max_attempts: 2
backoff_base_secs: 30
backoff_max_secs: 300
forward_min_interval_secs: 2
tree:
announce_min_interval_ms: 500
parent_hysteresis: 0.2 # cost improvement fraction for parent switch
hold_down_secs: 30 # suppress re-evaluation after switch
reeval_interval_secs: 60 # periodic cost-based re-evaluation (0 = disabled)
flap_threshold: 4 # parent switches before dampening
flap_window_secs: 60 # sliding window for flap detection
flap_dampening_secs: 120 # extended hold-down on flap
bloom:
update_debounce_ms: 500
session:
default_ttl: 64
pending_packets_per_dest: 16
pending_max_destinations: 256
idle_timeout_secs: 90
coords_warmup_packets: 5
coords_response_interval_ms: 2000
mmp:
mode: full # full | lightweight | minimal
log_interval_secs: 30
owd_window_size: 32
session_mmp:
mode: full # full | lightweight | minimal
log_interval_secs: 30
owd_window_size: 32
ecn:
enabled: true # ECN congestion signaling (CE flag relay)
loss_threshold: 0.05 # MMP loss rate threshold for CE marking (5%)
etx_threshold: 3.0 # MMP ETX threshold for CE marking
rekey:
enabled: true # periodic Noise rekey for forward secrecy
after_secs: 120 # rekey interval (seconds)
after_messages: 65536 # rekey after N messages sent
control:
enabled: true
socket_path: null # null = auto ($XDG_RUNTIME_DIR → /run/fips → /tmp fallback)
buffers:
packet_channel: 1024
tun_channel: 1024
dns_channel: 64
tun:
enabled: false
name: "fips0"
mtu: 1280
dns:
enabled: true
bind_addr: "127.0.0.1"
port: 5354
ttl: 300
transports:
udp:
bind_addr: "0.0.0.0:2121"
mtu: 1280
recv_buf_size: 2097152 # 2 MB (kernel doubles to 4 MB actual)
send_buf_size: 2097152 # 2 MB
# ethernet: # uncomment to enable (requires CAP_NET_RAW)
# interface: "eth0" # required: network interface name
# ethertype: 0x2121 # default EtherType
# mtu: null # null = interface MTU - 3 (typically 1497)
# recv_buf_size: 2097152 # 2 MB
# send_buf_size: 2097152 # 2 MB
# discovery: true # listen for beacons
# announce: false # broadcast beacons
# auto_connect: false # connect to discovered peers
# accept_connections: false # accept inbound handshakes
# beacon_interval_secs: 30 # beacon interval (min 10)
# tcp: # uncomment to enable TCP transport
# bind_addr: "0.0.0.0:8443" # listen address (omit for outbound-only)
# mtu: 1400 # default MTU
# connect_timeout_ms: 5000 # outbound connect timeout
# nodelay: true # TCP_NODELAY
# keepalive_secs: 30 # keepalive interval (0 = disabled)
# recv_buf_size: 2097152 # 2 MB
# send_buf_size: 2097152 # 2 MB
# max_inbound_connections: 256 # resource protection limit
# tor: # uncomment to enable Tor transport
# mode: "socks5" # "socks5", "control_port", or "directory"
# socks5_addr: "127.0.0.1:9050" # SOCKS5 proxy address
# connect_timeout_ms: 120000 # connect timeout (120s for Tor circuits)
# mtu: 1400 # default MTU
# # monitoring (control_port mode, or optional in directory mode):
# # control_addr: "/run/tor/control" # Unix socket or host:port
# # control_auth: "cookie" # "cookie" or "password:<secret>"
# # cookie_path: "/var/run/tor/control.authcookie"
# # directory mode (inbound via Tor-managed onion service):
# # directory_service:
# # hostname_file: "/var/lib/tor/fips/hostname"
# # bind_addr: "127.0.0.1:8444"
# # max_inbound_connections: 64
# ble: # uncomment to enable BLE transport (Linux only, requires BlueZ)
# adapter: "hci0" # HCI adapter name
# psm: 0x0085 # L2CAP PSM (133)
# mtu: 2048 # default MTU (negotiated per-link)
# max_connections: 7 # max concurrent BLE connections
# connect_timeout_ms: 10000 # outbound connect timeout
# advertise: true # broadcast BLE beacons
# scan: true # listen for BLE beacons
# auto_connect: false # connect to discovered peers
# accept_connections: true # accept incoming L2CAP connections
# probe_cooldown_secs: 30 # cooldown before re-probing same address
peers: # static peer list
# - npub: "npub1..."
# alias: "node-b"
# addresses:
# - transport: udp
# addr: "10.0.0.2:2121"
# priority: 100
# connect_policy: auto_connect
# auto_reconnect: true # reconnect after link-dead removal
```