Files
fips/docs/reference/cli-fipsctl.md
T
Johnathan Corgan 3a789370b9 Add an experimental native datagram API addressed by public key
A client process opens a flow to a peer's public key on a chosen port and
sends and receives datagrams on a file descriptor the daemon hands it. No
IPv6 emulation, no TUN device, no DNS: a datagram travels from key to key.
The feature is off by default and is not a stable interface.

The wire needs no change and gets none. Every FSP data packet has carried a
port pair inside its AEAD envelope since v0.2.0, and port 256 is simply the
IPv6 shim. What was missing was a way for a program to ask for a port of its
own and be handed the traffic.

Addressing is the part worth reading twice, because the obvious design is
wrong. The x-only public key is the address. An npub is that key written in
bech32, so converting between them is a local encoding rather than a lookup
or a name service. The 16-byte node address that travels on the wire is the
first half of a SHA-256 of the key: it is a truncated hash, it does not
invert, and it appears nowhere a client can see. An earlier iteration of this
work reported a peer by that hash and could supply a key only sometimes,
which is what treating a wire identifier as an identity produces.

An accepted flow therefore always knows its peer. The key is captured where
the peer is authenticated rather than looked up when a report is rendered:
every inbound datagram passes one call site inside a handler that refuses
anything whose session is not established, and the responder has already
rejected the session unless the claimed address derives from the key it
proved. Reaching for the identity cache instead gives a best-effort answer
from a structure that evicts.

A listener is a descriptor. The daemon writes one message per arrival to it,
carrying the new flow's descriptor and the peer's address, so poll, select
and epoll work on a listener and accepting is a recvmsg. That is what lets
the API be used from a program that already has an event loop, which a
command-and-reply listener could not support: an arrival could not be waited
on beside anything else. There is no accept command and no reject command.
Refusing a flow is closing the descriptor you were handed.

The Rust surface mirrors std::net. FipsStream::connect, FipsListener::bind,
incoming, accept, io::Result and an errno mapping rather than a bespoke
error type. An address is given as an npub, as a key, or as a pair, through
one parameter, the way ToSocketAddrs takes several spellings of one thing.
Each type holds its descriptor and copies of what setup told it and nothing
else, so a stream that outlives its setup connection is not representable.

set_nonblocking, AsFd and the four deadline methods carry the names and
signatures std::net uses for the same jobs. They were asked for by a user
integrating the API with tokio: AsyncFd requires a non-blocking descriptor,
and anything receiving from a peer needs a bounded wait. AsFd is the better
of the two descriptor accessors, because the borrow cannot outlive the value
that owns the descriptor, so a reactor cannot hold a registration for a
descriptor that has since been closed and its number reused by the next
open. The non-blocking flag is read, modified and written back rather than
assigned, since the flag word carries more than that one bit and a caller may
have set O_ASYNC. A zero timeout is refused with EINVAL, because the kernel
reads a zero timeval as "wait for ever", which inverts what a caller passing
zero means; std::net refuses it for the same reason. The two directions are
separate options and stay that way. FipsListener gets no timeout methods,
matching TcpListener: bounding an accept is set_nonblocking plus the caller's
own poll, which the reactor how-to builds. A flow taken from accept is
blocking whatever the listener was set to, because the two are separate
sockets and the daemon hands over a fresh one.

One rule has no counterpart in Berkeley sockets and a client author must know
it: the v1 wire carries no half-close, so nothing peer-driven ever closes a
flow. A server written to read until the flow ends waits for a signal that
cannot arrive, holding a thread and a flow per peer until its process exits.
A program decides its own termination, and the example serves one datagram
per flow.

The tests reach a live daemon rather than a stand-in. Every public item had a
unit test against a hand-written stand-in with canned replies, and the five
entry points a program actually calls first, connect, connect_from,
connect_at, bind and the SOCKET constant, had no coverage of any kind,
because the tests that appear to cover them build a Wire over a socket pair
and hand it to the private open and hold, so nothing ever resolved a socket
path or mapped its errors. examples/native-surface.rs walks all thirty-eight
items against a running daemon and reports the number of assertions it made.
The count is read from the recorder rather than written as a literal, and the
harness asserts the exit status, the completion marker and the count
together, so deleting an assertion fails the check rather than quietly
shrinking it. Watchdogs turn a hang into a named failure, which several of
the walked behaviours would otherwise produce. The shared Docker image is
built once for every integration leg, so the new binary is staged at all ten
places the existing one is, the interop builder included, which gets a stub
because those images exercise the wire between daemon versions and older refs
do not carry the example. The platform gating was tested rather than reasoned
about: flipping all eleven gates so the native API is excluded leaves the
crate compiling clean across the workspace, every target and the profiling
feature.

The shipped docs tree gains what only the LaTeX manual under design/ had,
which is not published with the daemon. A reference entry covers the whole
surface: addressing and the port tiers, the Berkeley mapping, every method on
FipsAddr, FipsStream, FipsListener and Incoming, the errno table, the
ceilings, the four places data disappears with nothing reported, the line
protocol and the command reference. The errno table gives names rather than
numbers, since the client maps each name onto the libc constant for the
platform it was built for and the supported platforms disagree on the
numbers. A tutorial side trip stands up two throwaway nodes on one machine,
peered over loopback UDP with no TUN and no DNS, then writes a listening
program and a connecting program against them; it needs neither the public
mesh nor root, because the native path is the one that does not go through
the IPv6 adapter. The obligations a client in another language carries are a
how-to of their own, since they are a task rather than a description:
reading the setup connection with recvmsg, associating a descriptor with the
last complete line, telling an empty datagram from a close, and six others.
Serving many peers from one poll loop is another, with the whole program,
because the straightforward listener spawns a thread per flow and that is
wrong at the node's ceiling of 256. The drop causes are a table mapping each
of the seven texts DropReason::as_str produces to the counter it increments,
with drop_oversize called out as the ninth counter that is not in the table.
What a daemon restart costs is a section of its own: every flow and listener
ends, descriptors do not survive, there is no resumption, and datagrams sent
but not yet forwarded are lost through a window nothing bounds.

A stack comparison diagram places the interface against the stack a reader
already knows: the same application over HTTP, TLS, TCP, IP and Ethernet on
one side, and over its own format, FSP, FMP and a FIPS transport on the
other, aligned so each row is one concern. The two columns are not
alternatives and are not drawn as such. An unmodified IPv6 program's packets
reach fips0, and the adapter hands each one to FSP as a payload, so the left
stack runs inside the right one; the left column ends at a fork, eth0 for the
ordinary internet and fips0 for the mesh, and an arrow leaves fips0 and runs
back up into FSP's input. The row where TCP would be is empty on purpose and
names Reliable Object Delivery, which is where that capability is expected to
land. ROD is a v2 capability, the box is dashed because none of it exists
yet, and the design entry says the part a reader needs most: nothing on the
surface anticipates it, so a program written today should assume it does not
exist. Both endpoints carry a scheme and a worked port,
https://<npub>.fips:443 and fips://<npub>:443, with a footnote saying the two
ports are not the same kind of thing, a TCP port inside the tunnel on the
left and an FSP port on the right. The fips:// form is a coinage: nothing in
the tree parses it, nothing registers the scheme, and the API takes a key and
a port as separate arguments rather than a URL. The diagram also says where
the right column stops, since FIPS over UDP still rides IP and Ethernet
beneath. It appears in fips-concepts.md and fips-ipv6-adapter.md, which were
making its argument in prose without a picture, and deliberately not in
fips-architecture.md, which already carries the OSI mapping and makes the
same point about the transport row.

The gateway's control socket moves onto the same bind policy this API uses,
which is the one change here that touches deployed behaviour: fips-gateway
now tightens /run/fips to 0750. That is unreachable under the packaged
deployment, where fips.service has already created the directory at that
mode, and reachable for a source build or a container that starts the gateway
alone.

One changelog entry under Added, describing the released state: what a
client opens and reads, the addressing and why the node address is not it,
the listener being a descriptor, the std::net shape of the Rust surface,
and the one rule Berkeley sockets have no counterpart for. It says in as
many words that the wire is unchanged.
2026-08-21 05:48:23 +00:00

301 lines
15 KiB
Markdown

# `fipsctl`
Command-line client for the FIPS daemon's control socket.
## Synopsis
```text
fipsctl [-s SOCKET] <subcommand> [args...]
```
## Description
`fipsctl` connects to a running daemon over its control socket
(Unix domain socket on Linux/macOS, TCP loopback on Windows), sends
one JSON request, and pretty-prints the response. Exits with a
non-zero status if the socket cannot be reached, the daemon returns an
error, or the request times out.
`fipsctl keygen` is a special case: it does not contact the daemon and
operates purely on local files.
For the line-delimited JSON wire protocol, see
[control-socket.md](control-socket.md). For the YAML configuration
that defines the socket location, see
[configuration.md](configuration.md).
## Global Options
| Flag | Argument | Description |
| ---- | -------- | ----------- |
| `-s`, `--socket` | `PATH` | Override the control-socket path (Linux/macOS) or TCP port (Windows). |
| `-V`, `--version` | — | Print the short version. |
| `--version` | — | Print the long version. |
| `-h`, `--help` | — | Print usage and exit. Per-subcommand help via `fipsctl <subcommand> --help`. |
## Subcommands
### `show <what>`
Read-only queries against the daemon. Each subcommand maps 1:1 to a
control-socket query (see [control-socket.md](control-socket.md)) and
prints the response's `data` object as pretty JSON.
| Subcommand | Control-socket command | Returns |
| ---------- | ---------------------- | ------- |
| `show status` | `show_status` | Node-level status: identity, version, peer/link/session counts, TUN state, recent sparklines. |
| `show peers` | `show_peers` | Authenticated peer list with link IDs, transport addresses, MMP metrics, Noise/rekey state. |
| `show links` | `show_links` | Active links (one per FMP-authenticated peer): direction, state, byte counters. |
| `show tree` | `show_tree` | Spanning-tree state: root, my coordinates, parent, peer declarations. |
| `show sessions` | `show_sessions` | End-to-end FSP sessions: state, traffic counters, session-MMP metrics, path MTU. |
| `show bloom` | `show_bloom` | Bloom-filter state: own filter sequence, leaf dependents, per-peer filter summaries. |
| `show mmp` | `show_mmp` | MMP metrics summary: per-peer link-layer metrics and per-session session-layer metrics. |
| `show cache` | `show_cache` | Coordinate cache: TTL, fill ratio, per-destination coords and path MTU. |
| `show connections` | `show_connections` | Pending handshake connections: state, idle time, resend count. |
| `show transports` | `show_transports` | Transport instances: type, state, MTU, local address, per-transport stats. |
| `show routing` | `show_routing` | Routing summary: pending lookups, retry state, forwarding/discovery/error/congestion counters. |
| `show identity-cache` | `show_identity_cache` | Cached `(node_addr → npub)` entries with last-seen timestamps. |
| `show native-flows` | `show_native_flows` | Native datagram API: open and pending flows with their ports, queue depth and age, bound listeners with their backlog, and the `native` counters. |
### `acl <what>`
| Subcommand | Control-socket command | Returns |
| ---------- | ---------------------- | ------- |
| `acl show` | `show_acl` | Loaded peer-ACL state: allow/deny files, effective mode, default decision, entry counts. |
### `stats <what>`
Time-series metrics from the in-process history rings.
| Subcommand | Control-socket command | Description |
| ---------- | ---------------------- | ----------- |
| `stats list` | `show_stats_list` | Enumerate available metrics, their units, and the per-ring retention windows. |
| `stats metrics` | `show_metrics` | Dump current counter values for every protocol metric family (`forwarding`, `discovery`, `tree`, `bloom`, `congestion`, `errors`, `native`). |
| `stats peers` | `show_stats_peers` | List peers tracked in stats history (active or recently active). |
| `stats history <metric> [options]` | `show_stats_history` | Fetch a time-series window for one metric. |
`stats history` options:
| Flag | Argument | Default | Description |
| ---- | -------- | ------- | ----------- |
| `--peer` | `npub` or hostname | *(none)* | Required for per-peer metrics; resolves through `/etc/fips/hosts` if not an npub. |
| `--window` | `<N>s` / `<N>m` / `<N>h` | `10m` | Window duration. |
| `--granularity` | `1s` or `1m` | `1s` | Ring resolution. `1s` uses the fast ring; `1m` uses the slow ring. |
| `--plot` | — | off | Render a Unicode-block sparkline to stdout instead of JSON. |
### `keygen [options]`
Generate a new FIPS identity keypair locally. Does not contact the
daemon.
| Flag | Argument | Default | Description |
| ---- | -------- | ------- | ----------- |
| `-d`, `--dir` | `DIR` | `/usr/local/etc/fips` (macOS), `/etc/fips` (other Unix), `%APPDATA%\fips` (Windows) | Output directory for `fips.key` and `fips.pub`. Matches the directory the platform's packaging installs config into, which is where the daemon derives the key paths from. |
| `-f`, `--force` | — | off | Overwrite an existing `fips.key`. |
| `-s`, `--stdout` | — | off | Print `nsec` then `npub` to stdout instead of writing files. |
`fips.key` is written with mode `0600` and `fips.pub` with mode `0644`
on Unix. After running `keygen`, set `node.identity.persistent: true`
in `fips.yaml` or the daemon will overwrite the keys on next start.
### `connect <peer> <address> <transport>`
Tell the daemon to dial a peer over a specific transport.
| Argument | Description |
| -------- | ----------- |
| `peer` | npub (bech32) or hostname from `/etc/fips/hosts`. |
| `address` | Transport endpoint, e.g. `192.168.1.10:2121`, `[2001:db8::1]:2121`, or a Tor onion. FIPS-mesh ULAs (`fd00::/8`) are rejected for the IP-based transports (udp, tcp, ethernet). |
| `transport` | One of `udp`, `tcp`, `tor`, `nym`, `ethernet`. The named transport must be configured and running. |
### `disconnect <peer>`
Tell the daemon to drop a peer link.
| Argument | Description |
| -------- | ----------- |
| `peer` | npub (bech32) or hostname from `/etc/fips/hosts`. |
### `probe <target>`
Diagnose whether a mesh endpoint is reachable, in five stages, and
report a per-stage verdict so a partial failure localizes itself.
| Argument | Description |
| -------- | ----------- |
| `target` | npub (bech32) or hostname from `/etc/fips/hosts`. |
| `--json` | Emit the report as JSON instead of human-readable text. |
| `--timeout <secs>` | Client-side ceiling. Defaults to the budget the daemon computed, which scales with its tick interval. |
The stages are:
1. **bloom** — does any peer's announced filter claim the target, and
did a LookupRequest therefore go out? A miss ends the probe here and
is a statement about the mesh's own knowledge: nobody has heard of
this address. Skipped when the coordinates are already cached, and
when the target is a directly connected peer.
2. **discovery** — waiting for a LookupResponse to answer with
coordinates. Each request the node sends gets its own line under the
stage, with the timeout that attempt was given and whether it drew a
reply. Failing here is the opposite finding to a bloom miss: a peer's
filter did claim the address, and nothing answered for it.
3. **path** — the least-common-ancestor walk between the two
coordinates, plus the next hop this node would select. This is a
**local computation, not a traceroute**: no hop beyond the first is
contacted, and the tree distance is an upper bound on the real hop
count because a crosslink cut-through can deliver in fewer hops.
When no coordinates were available the walk is not computed at all:
`path.coords_known` is false and every tree field is null, rather
than a default that would read as a finding about the spanning tree.
4. **session** — a full Noise XK handshake over FSP. Completing it is
genuine end-to-end evidence: our route reached them, their route
reached us, and the remote holds the expected static key.
5. **rtt** — one MMP sender/receiver report exchange, for a real
round-trip time.
Exit status is 0 only for an overall verdict of `ok`; `partial`,
`failed` and `cancelled` all exit 1.
**The stage block fills in as the probe runs.** Each stage reports its
verdict at the moment it reaches one, rather than the whole report
arriving at the end, so a slow stage is visible as the stage that is
slow. On a terminal the block is redrawn in place, with a spinner and a
running elapsed on whichever stage is working; piped or redirected, each
row is printed once, when it settles, and the transcript ends up the
same block. A running stage reports only what the daemon has observed —
which requests have gone unanswered so far, whether the handshake is in
flight, how many receiver reports have arrived — and never previews an
outcome it does not have yet. The per-request lines under the discovery
stage carry the configured timeout of each attempt in parentheses, which
is the node's own ladder rather than a measurement.
The elapsed column comes from the daemon's clock throughout: a finished
stage carries its own tick-quantized figure, and the stage still running
carries the report's elapsed less the stages already accounted for.
Nothing in that column is measured client-side.
**Stages that were never attempted get no row.** A failure marks
everything behind it as not reached, and the report says that once, in
the failed row, rather than three more times. Two cases deliberately keep
their rows: a *skipped* stage, because a skip is a result naming why that
stage was unnecessary, and everything after a *failed path* stage,
because the path preview touches nothing and the session can still
succeed where the preview named no next hop.
Below the stage block, the `path:` line renders the whole tree walk on
one line, from this node to the target, through the least common
ancestor, which is emphasised on a terminal. It is the same computed
walk the `ours`, `theirs` and `tree walk` lines describe, read in one
piece.
`--json` is unaffected and still emits exactly one document, when the
probe ends, so a script parsing the report does not have to skip past
progress output.
**What the probe leaves behind.** It tears down a session it opened
itself and never touches one that already existed. Three residues are
deliberate and worth knowing about:
- The coordinate-cache and identity-cache entries a lookup produced are
not evicted. They are TTL-bounded shared read caches, and evicting
them could strand an unrelated flow mid-route.
- The remote's half of a probe-created session persists until its own
idle timeout (default 90s). There is no teardown wire message. In the
window between our removal and its idle purge, any session frame the
remote sends lands here as one unknown-session reject.
- To obtain a round-trip time the probe sends a `CoordsWarmup`, which
starts MMP reporting on the session. On a session the probe does not
own, that reporting continues until the idle purge — the same traffic
any single data packet would cause, and bounded, but a real change to
a session the probe did not create. The report names it under
`cleanup.warmups_sent`.
Running a probe against a production node is safe: the job carries its
own deadline daemon-side, so it cleans up whether or not the client is
still there.
### `profile tick <on|off|status>`
> **Reading the output.** Step durations are wall clock measured across `await`
> points, not CPU time: a step that waits on I/O accrues that wait, and other
> tasks may run inside the span. That is the intended measure for head-of-line
> delay, and it means a large step is not necessarily an expensive one.
> `arm_starvation` is measured directly as the entry time minus the deadline
> the interval scheduled that tick for. It is not derived from
> `tick_entry_gap`, which carries no starvation signal on its own: under a
> steady delay every gap is exactly one tick period.
Start, stop and inspect a capture of the rx-loop tick body. **Present
only when both `fipsctl` and the daemon are built with
`--features profiling`**; the feature is off by default, so a stock
package does not carry this subcommand and a stock daemon reports
`profile_tick_*` as an unknown command.
| Subcommand | Control-socket command | Description |
| ---------- | ---------------------- | ----------- |
| `profile tick on` | `profile_tick_on` | Create the capture file and start recording. Fails if a capture is already running (naming the active file) or if the directory cannot be written. |
| `profile tick off` | `profile_tick_off` | Stop the capture. The writer is woken immediately, drains once more and is joined, so the command returns promptly. Succeeds, reporting nothing active, when no capture is running. |
| `profile tick status` | `profile_tick_status` | Report `idle`, `running`, `stopped_by_cap` or `stopped_by_error`, plus the active path, bytes written, flush interval and byte cap. |
`profile tick on` options:
| Flag | Argument | Default | Description |
| ---- | -------- | ------- | ----------- |
| `--dir` | directory path | `/var/log/fips` | Where to write the capture. Created if absent. Use it to profile a non-root `cargo run`, or on a platform whose log root differs. |
One file is written per capture, named `profile-<UTC timestamp>.tsv`.
It opens with a `#`-prefixed header block (node npub, build version,
platform, configured tick period, flush interval, byte cap, start
time), then a tab-separated column header, then one row per measured
step per flush interval:
```text
ts_unix kind domain name count max total unit
```
`kind` is `step` for a timed span and `gauge` for a sampled scalar, so
a gauge value never lands under a duration column; `unit` names the
unit of `max` and `total` for that row. Every step present in the build
gets a row every interval, including zero-count rows. Gauges cover
ticks per interval, peer count, the wall gap between successive
tick-arm entries, and the arm-starvation delay, which is measured
against the deadline the tick was scheduled for rather than derived
from the gap.
A capture stops itself on reaching 32 MB, appending a `#` line saying
so; `profile tick status` then reports `stopped_by_cap` until the next
`on` or `off` clears it.
## Exit Codes
| Code | Meaning |
| ---- | ------- |
| `0` | Daemon returned `{"status":"ok",...}`. |
| `1` | Argument parse failure, control-socket connection failure, daemon returned `{"status":"error",...}`, or local I/O failure (keygen). The error message is printed to stderr. |
## Environment
| Variable | Description |
| -------- | ----------- |
| `XDG_RUNTIME_DIR` | Used to derive the default control-socket path when `/run/fips` is absent. |
`fipsctl` does not consume `RUST_LOG`; logging is for the daemon.
## Files
| Path | Purpose |
| ---- | ------- |
| `/etc/fips/hosts` | Maps hostnames to npubs for the `connect`, `disconnect`, and `--peer` arguments. See [configuration.md](configuration.md). |
| Control socket (default) | Same resolution as the daemon: `/run/fips/control.sock` if present; then `/var/run/fips/control.sock` on macOS/FreeBSD if present; then `$XDG_RUNTIME_DIR/fips/control.sock`; finally `/tmp/fips-control.sock` (Unix). A privileged macOS daemon bootstraps the private `/var/run/fips` directory. Windows uses TCP `localhost:21210`. |
If you get `Permission denied` connecting to the socket on Linux,
add your user to the `fips` group (`sudo usermod -aG fips $USER`)
and log out and back in.
## See also
- [`fips`](cli-fips.md) — the daemon.
- [`fipstop`](cli-fipstop.md) — live-status TUI.
- [control-socket.md](control-socket.md) — wire protocol.
- [configuration.md](configuration.md) — YAML reference.