Files
punktfunk/crates/punktfunk-core/src/quic.rs
T
enricobuehler 3e6c9f6060 feat(gamepad): add virtual Xbox One/Series + DualShock 4 pad types
Extends virtual-controller support beyond Xbox 360 + DualSense. Goal: a
physical Xbox One or PS4 pad on the client gets a near-native matching virtual
pad on the host, auto-resolved from the controller type.

Protocol/core:
- GamepadPref gains XboxOne (wire 3) + DualShock4 (wire 4); to_u8/from_u8/
  from_name/as_str + C ABI PUNKTFUNK_GAMEPAD_XBOXONE/_DUALSHOCK4 constants
  (compile-time guard ties them to the enum). Single-byte wire form is
  unchanged, so it's forward-compatible (older peers degrade to Auto).

Host (Linux):
- New UHID DualShock 4 backend (inject/dualshock4.rs) bound by hid-playstation:
  lightbar, touchpad, motion, rumble — DualSense minus adaptive triggers /
  player LEDs / mute. Reuses the DualSense pure state + button mapping; only the
  report byte layout, the real-DS4 HID descriptor, the GET_REPORT handshake
  (0x12 MAC mandatory; 0x02 calibration; 0xa3 firmware) and the touchpad
  resolution (1920x942) differ. Touchpad/motion ride the existing 0xCC plane,
  lightbar the 0xCD Led plane (deduped); rumble the universal 0xCA plane.
- Xbox One/Series is the uinput Xbox-360 backend parameterized with the One S
  USB identity (045e:02ea) for matching glyphs — XInput-identical otherwise.
- PadBackend dispatch + resolver handle both; off Linux the UHID pads and
  One/Series fold into Xbox 360. Windows-host DS4 (ViGEm) deferred.

Clients (auto-resolve physical pad -> virtual type, plus manual settings):
- Linux/Windows (SDL3): SDL_GAMEPAD_TYPE_PS4 -> DualShock 4, _XBOXONE ->
  Xbox One; PadInfo carries the resolved pref; DS4 touchpad/motion capture +
  lightbar already type-agnostic. Linux settings combo + label updated.
- Apple (GameController): GCDualShockGamepad/GCXboxGamepad detection, DS4
  touchpad capture, settings picker entries.
- Android (Kotlin): InputDevice VID/PID auto-detect (matching the other
  clients) + settings entries.
- probe: --gamepad help/aliases.

Also hardens the Android JNI boundary: wrap the teardown + poll-thread shims in
catch_unwind so a panic degrades to a logged no-op instead of aborting the app.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-06-21 13:34:44 +00:00

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//! `punktfunk/1` — the native control plane, gated behind the `quic` feature.
//!
//! GameStream is punktfunk's compatibility layer; this is the start of its own protocol. A QUIC
//! connection (quinn, tokio — control plane only, never the per-frame path) carries a
//! length-prefixed binary handshake on one bidirectional stream:
//!
//! ```text
//! client → host Hello { abi_version }
//! host → client Welcome { abi_version, session: full data-plane Config + mode + UDP port }
//! client → host Start { client_udp_port }
//! ```
//!
//! after which both sides bring up a [`crate::session::Session`] over a plain
//! [`UdpTransport`](crate::transport::udp) (native threads, no async) and the host streams.
//! The Welcome carries everything the core negotiates — FEC scheme (including GF(2¹⁶)
//! Leopard, which GameStream can't express), shard sizing, crypto key/salt — so the data
//! plane is exactly the hardened core `Session`.
//!
//! Transport security: the host presents a long-lived self-signed certificate
//! ([`endpoint::server_with_identity`]) and the client pins its SHA-256 fingerprint
//! ([`endpoint::client_pinned`]; no pin = trust-on-first-use, with the observed fingerprint
//! reported back for persisting). The data plane adds AES-GCM on top.
//! All integers little-endian; every message is `u16 length || payload`.
use crate::config::{
CompositorPref, Config, FecConfig, FecScheme, GamepadPref, Mode, ProtocolPhase, Role,
};
use crate::error::{PunktfunkError, Result};
/// Protocol magic + version, first bytes of the positional handshake (Hello/Welcome/Start).
pub const MAGIC: &[u8; 4] = b"PKF1";
/// Magic for typed post-handshake / pairing control messages. A distinct magic keeps the
/// typed namespace disjoint from the positional handshake: a `Hello` (whose abi_version
/// byte sits where a type byte would) can never be misparsed as a control message, and
/// vice-versa, regardless of field values.
pub const CTL_MAGIC: &[u8; 4] = b"PKFc";
/// `client → host`: open the session, requesting a display mode (the host creates its
/// virtual output at exactly this size/refresh — native resolution end to end).
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct Hello {
pub abi_version: u32,
pub mode: Mode,
/// Which compositor the client would like the host to drive (`Auto` = host decides). The
/// host honors it only if that backend is available, else falls back and reports the real
/// choice in [`Welcome::compositor`]. Appended to the wire form — omitted by older clients
/// (decodes to `Auto`).
pub compositor: CompositorPref,
/// Which virtual gamepad the host should create for this session's pads (`Auto` = host
/// decides: its `PUNKTFUNK_GAMEPAD` env var, else X-Box 360). Resolved choice echoed in
/// [`Welcome::gamepad`]. Appended to the wire form — omitted by older clients (decodes
/// to `Auto`).
pub gamepad: GamepadPref,
/// The client's desired video encoder bitrate, in kilobits per second. `0` = no preference
/// (the host uses its default). The host clamps the request to a supported range and reports
/// the value it actually configured in [`Welcome::bitrate_kbps`]. Appended to the wire form —
/// omitted by older clients (decodes to `0`, i.e. host default).
pub bitrate_kbps: u32,
/// Human-readable device name ("Enrico's MacBook"), shown by the host when this device knocks
/// on a pairing-required host (the delegated-approval pending list) and stored on approval.
/// Appended to the wire form as `len u8 || UTF-8` (≤ [`HELLO_NAME_MAX`] bytes) — omitted by
/// older clients (decodes to `None`; the host falls back to a fingerprint-derived label).
pub name: Option<String>,
/// Library entry the client wants this session to launch (the store-qualified `GameEntry.id`,
/// e.g. `steam:570` / `custom:abc123`). The host resolves it against ITS OWN library and runs
/// the matching launch recipe in the session — the client never sends a raw command, so a
/// remote peer can't inject one. `None` = no game requested (the host's default session).
/// Appended after `name` as `len u8 || UTF-8` (≤ [`HELLO_LAUNCH_MAX`] bytes); when present but
/// `name` is absent, a zero-length name placeholder precedes it so the offset stays
/// deterministic. Omitted by older clients (decodes to `None`).
pub launch: Option<String>,
/// Client video capabilities the host may use to upgrade the stream — a bitfield of
/// [`VIDEO_CAP_10BIT`] (the client can decode 10-bit Main10 HEVC) and [`VIDEO_CAP_HDR`]
/// (the client can present BT.2020 PQ HDR10). The host enables a 10-bit / HDR encode ONLY
/// when the matching bit is set, so an older client (decodes to `0`) always gets the 8-bit
/// BT.709 stream it understands. Appended after `launch` as a single trailing byte; a
/// zero-length name/launch placeholder precedes it when those are absent so the offset stays
/// deterministic. Omitted by older clients (decodes to `0`).
pub video_caps: u8,
}
/// [`Hello::video_caps`] bit: the client can decode a 10-bit (Main10) HEVC stream.
pub const VIDEO_CAP_10BIT: u8 = 0x01;
/// [`Hello::video_caps`] bit: the client can present BT.2020 PQ HDR10 (implies 10-bit).
pub const VIDEO_CAP_HDR: u8 = 0x02;
/// Per-session colour signalling (CICP / ITU-T H.273 code points) the host resolved for the
/// encoded video, carried on [`Welcome`]. A client configures its decoder/presenter from these
/// instead of inferring them from the bitstream VUI. An older host omits the bytes on the wire →
/// [`ColorInfo::SDR_BT709`] (the 8-bit BT.709 limited stream every pre-HDR build produced).
///
/// The *static* HDR mastering metadata (ST.2086 + content light level) is larger and can change
/// mid-stream, so it rides the [`HDR_META_MAGIC`] datagram rather than this fixed struct.
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub struct ColorInfo {
/// CICP colour primaries: 1 = BT.709, 9 = BT.2020.
pub primaries: u8,
/// CICP transfer characteristics: 1 = BT.709, 16 = PQ (SMPTE ST.2084), 18 = HLG.
pub transfer: u8,
/// CICP matrix coefficients: 1 = BT.709, 9 = BT.2020 non-constant-luminance.
pub matrix: u8,
/// `video_full_range_flag`: 0 = limited/studio range, 1 = full range.
pub full_range: u8,
}
impl ColorInfo {
/// CICP colour-primaries code point: BT.709.
pub const CP_BT709: u8 = 1;
/// CICP colour-primaries code point: BT.2020.
pub const CP_BT2020: u8 = 9;
/// CICP transfer code point: BT.709.
pub const TRC_BT709: u8 = 1;
/// CICP transfer code point: PQ (SMPTE ST.2084).
pub const TRC_PQ: u8 = 16;
/// CICP transfer code point: HLG (ARIB STD-B67 / BT.2100).
pub const TRC_HLG: u8 = 18;
/// CICP matrix code point: BT.709.
pub const MC_BT709: u8 = 1;
/// CICP matrix code point: BT.2020 non-constant-luminance. (Never emit 10 / constant-luminance —
/// no client decodes it.)
pub const MC_BT2020_NCL: u8 = 9;
/// 8-bit BT.709 limited-range SDR — what every pre-HDR build produced, and the back-compat
/// default when a peer omits the colour bytes.
pub const SDR_BT709: ColorInfo = ColorInfo {
primaries: Self::CP_BT709,
transfer: Self::TRC_BT709,
matrix: Self::MC_BT709,
full_range: 0,
};
/// BT.2020 PQ (HDR10), limited range — what the Windows host's HEVC VUI emits.
pub const HDR10_BT2020_PQ: ColorInfo = ColorInfo {
primaries: Self::CP_BT2020,
transfer: Self::TRC_PQ,
matrix: Self::MC_BT2020_NCL,
full_range: 0,
};
/// True when the transfer is an HDR curve (PQ or HLG): the stream needs HDR present, and
/// (for PQ) a [`HdrMeta`] datagram carries the mastering metadata.
pub fn is_hdr(&self) -> bool {
self.transfer == Self::TRC_PQ || self.transfer == Self::TRC_HLG
}
}
impl Default for ColorInfo {
fn default() -> Self {
Self::SDR_BT709
}
}
/// Longest device name carried in a [`Hello`] (bytes of UTF-8; longer names are truncated on
/// encode, rejected on decode — a one-byte length prefix caps it at 255 anyway).
pub const HELLO_NAME_MAX: usize = 64;
/// Longest library id carried in a [`Hello::launch`] (bytes of UTF-8). Ids are short
/// (`steam:<appid>` / `custom:<12 hex>`); the cap just bounds an attacker-controlled field.
pub const HELLO_LAUNCH_MAX: usize = 128;
/// `host → client`: the complete session offer.
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub struct Welcome {
pub abi_version: u32,
/// Host UDP port for the data plane.
pub udp_port: u16,
pub mode: Mode,
pub fec: FecConfig,
pub shard_payload: u16,
pub encrypt: bool,
pub key: [u8; 16],
pub salt: [u8; 4],
/// Seed/testing: how many frames the host will send (0 = unbounded).
pub frames: u32,
/// The compositor the host actually resolved for this session (the client's
/// [`Hello::compositor`] preference if available, else the host's auto-detected choice).
/// Appended to the wire form — `Auto` when an older host omitted it (i.e. "unknown").
pub compositor: CompositorPref,
/// The virtual gamepad backend the host actually resolved (the client's [`Hello::gamepad`]
/// preference if available, else env var / X-Box 360). A client uses this to know whether
/// DualSense feedback (0xCD) can arrive at all. Appended to the wire form — `Auto` when an
/// older host omitted it (i.e. "unknown, assume X-Box 360").
pub gamepad: GamepadPref,
/// The encoder bitrate the host actually configured for this session, in kilobits per second
/// (the client's [`Hello::bitrate_kbps`] clamped to the host's supported range, or the host
/// default when the client requested `0`). Appended to the wire form — `0` when an older host
/// omitted it (i.e. "unknown").
pub bitrate_kbps: u32,
/// The luma/chroma bit depth the host actually encodes at — `8` (default / older host) or
/// `10` (Main10, enabled only when the client advertised [`VIDEO_CAP_10BIT`]). The client
/// configures its decoder for 10-bit (P010) when this is `10`. Appended to the wire form as a
/// single trailing byte; `8` when an older host omitted it.
pub bit_depth: u8,
/// The colour signalling (CICP primaries/transfer/matrix/range) the host encodes with — BT.709
/// limited SDR by default, BT.2020 PQ when a 10-bit HDR session was negotiated. Appended after
/// `bit_depth` as 4 trailing bytes; an older host that omits them decodes to
/// [`ColorInfo::SDR_BT709`]. The client configures its decoder/presenter from this instead of
/// guessing from the bitstream; the mastering metadata arrives separately on [`HDR_META_MAGIC`].
pub color: ColorInfo,
}
/// `client → host`: data plane is bound, begin streaming.
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub struct Start {
pub client_udp_port: u16,
}
/// `client → host`, any time after [`Start`]: switch the session to a new display mode
/// (window resized, refresh changed) without reconnecting. The host answers with
/// [`Reconfigured`]; on acceptance it rebuilds its virtual output + encoder at the new
/// mode and the stream continues over the unchanged data plane — the first new-mode frame
/// is an IDR with in-band parameter sets, which is all a decoder needs to follow.
///
/// Post-handshake messages carry a type byte after the magic (the handshake itself is
/// positional and stays untyped for wire compatibility).
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub struct Reconfigure {
pub mode: Mode,
}
/// `host → client`: answer to [`Reconfigure`]. `accepted = false` means the requested
/// mode was rejected (e.g. exceeds encoder limits) and the session continues at `mode`
/// (the still-active one); `true` means `mode` is now being switched to live.
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub struct Reconfigured {
pub accepted: bool,
pub mode: Mode,
}
/// `client → host`, any time after [`Start`]: ask the host's encoder to emit a fresh IDR
/// keyframe NOW. The infinite-GOP stream opens with one IDR then sends P-frames only, so a
/// decoder that wedges (a lost/corrupt opening IDR, a bad early P-frame — most likely on the
/// cold first session) would otherwise stay frozen until the next loss-triggered recovery
/// keyframe, which may be far off. The client sends this when it detects a stalled decode;
/// the host forces the next frame to be an IDR with in-band parameter sets, recovering the
/// picture in ~one frame. Fire-and-forget — no reply (the recovered IDR is the ack).
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub struct RequestKeyframe;
/// `client → host`, periodic: the client's observed data-plane loss, so the host can size FEC to
/// the link instead of a flat percentage (adaptive FEC). `loss_ppm` is parts-per-million of shards
/// that arrived missing-but-recovered (plus a bump when frames went unrecoverable) over the report
/// window — i.e. the loss FEC is currently absorbing. The host maps it to a recovery percentage,
/// clamped to a sane band, and applies it live; a clean link decays toward the floor (fewer packets,
/// which directly helps a packet-rate-bound uplink like the Steam Deck's WiFi tx). Fire-and-forget.
/// A host that predates this ignores it (unknown control message) and keeps its static FEC.
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub struct LossReport {
pub loss_ppm: u32,
}
/// `client → host`, any time after [`Start`]: run a bandwidth speed test. The host bursts
/// filler access units (flagged [`crate::packet::FLAG_PROBE`]) over the data plane at
/// `target_kbps` of application goodput for `duration_ms`, *pausing video for the duration*, then
/// replies with [`ProbeResult`]. The client measures the received probe bytes + time to estimate
/// the link's sustainable rate (and the loss vs. the host's reported send count) so it can pick a
/// [`Hello::bitrate_kbps`]. The host clamps both fields to sane bounds.
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub struct ProbeRequest {
/// Goodput rate the host should send the probe at, in kilobits per second.
pub target_kbps: u32,
/// How long to burst, in milliseconds.
pub duration_ms: u32,
}
/// `host → client`: the probe burst is finished. Reports what the host actually put on the wire so
/// the client can split the two failure modes apart: **host-side** drops (the send buffer couldn't
/// keep up — raise `net.core.wmem_max`) vs **link** loss (wire packets the air dropped). The client
/// measures delivered wire packets itself and computes:
///
/// - link loss = `(wire_packets_sent received) / wire_packets_sent`
/// - host drop = `send_dropped / (wire_packets_sent + send_dropped)`
/// - throughput = `received_wire_bytes * 8 / duration_ms`
///
/// Counting delivered traffic at the *packet* level (not whole reassembled AUs) makes the figure
/// degrade gracefully past the FEC budget instead of cliffing to zero.
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub struct ProbeResult {
/// Total access-unit payload bytes the host emitted for the probe (application goodput offered).
pub bytes_sent: u64,
/// Number of probe access units the host emitted.
pub packets_sent: u32,
/// The burst's actual duration in milliseconds (the host clamps/measures the request).
pub duration_ms: u32,
/// Wire packets the kernel ACCEPTED for transmission — what actually went on the link (offered
/// minus the send-buffer drops below). `0` from a pre-wire-stats host (back-compat decode).
pub wire_packets_sent: u32,
/// Wire packets the host could NOT hand to the kernel (send buffer full): the host-side ceiling.
pub send_dropped: u32,
}
/// `client → host`, right after [`Start`]: one round of the wall-clock skew handshake. The client
/// stamps `t1_ns` (its monotonic-since-epoch clock) and sends; the host echoes it in [`ClockEcho`]
/// with its own receive/send stamps. A few rounds let the client estimate the host↔client clock
/// offset, so the per-frame `capture→reassembled` latency (the AU `pts_ns` is the host's capture
/// clock) is meaningful across machines, not just same-host. An old host ignores it (the client
/// times out and assumes a shared clock).
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub struct ClockProbe {
pub t1_ns: u64,
}
/// `host → client`: answer to [`ClockProbe`]. `t2_ns` is when the host received the probe and
/// `t3_ns` when it sent this echo (both the host clock); `t1_ns` is the client's send stamp echoed
/// back. With the client's receive time `t4`, offset = ((t2t1)+(t3t4))/2 (host minus client) and
/// RTT = (t4t1)(t3t2). See [`clock_offset_ns`].
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub struct ClockEcho {
pub t1_ns: u64,
pub t2_ns: u64,
pub t3_ns: u64,
}
/// Estimate the host↔client clock offset (**host minus client**, ns) and RTT (ns) from skew-handshake
/// samples `(t1, t2, t3, t4)` — NTP's formula, taking the **minimum-RTT** sample (least queuing
/// noise; also discards the first round's host-setup latency). Offset is positive when the host
/// clock is ahead of the client's; add it to a client timestamp to express it in the host clock.
/// Returns `None` for an empty sample set.
pub fn clock_offset_ns(samples: &[(u64, u64, u64, u64)]) -> Option<(i64, u64)> {
samples
.iter()
.map(|&(t1, t2, t3, t4)| {
let rtt = ((t4 as i128 - t1 as i128) - (t3 as i128 - t2 as i128)).max(0) as u64;
let offset = (((t2 as i128 - t1 as i128) + (t3 as i128 - t4 as i128)) / 2) as i64;
(offset, rtt)
})
.min_by_key(|&(_, rtt)| rtt)
}
/// Type byte of [`Reconfigure`] (first byte after the magic).
pub const MSG_RECONFIGURE: u8 = 0x01;
/// Type byte of [`Reconfigured`].
pub const MSG_RECONFIGURED: u8 = 0x02;
/// Type byte of [`RequestKeyframe`].
pub const MSG_REQUEST_KEYFRAME: u8 = 0x03;
/// Type byte of [`LossReport`].
pub const MSG_LOSS_REPORT: u8 = 0x04;
/// Type byte of [`ProbeRequest`].
pub const MSG_PROBE_REQUEST: u8 = 0x20;
/// Type byte of [`ProbeResult`].
pub const MSG_PROBE_RESULT: u8 = 0x21;
/// Type byte of [`ClockProbe`].
pub const MSG_CLOCK_PROBE: u8 = 0x30;
/// Type byte of [`ClockEcho`].
pub const MSG_CLOCK_ECHO: u8 = 0x31;
// ---------------------------------------------------------------------------------------------
// Pairing ceremony (typed control messages): instead of a session Hello, a client may open
// the control stream with PairRequest. The host shows a short PIN out-of-band (log/UI); the
// user types it into the client.
//
// Trust is established by **SPAKE2** (a balanced PAKE), NOT a hash of the PIN. SPAKE2 turns
// the low-entropy PIN into a high-entropy shared key via a Diffie-Hellman exchange; the only
// thing an active man-in-the-middle who terminates the (TOFU) ceremony learns is whether a
// single PIN guess was right — there is no transcript value that reveals the PIN to an
// *offline* dictionary search (the fatal flaw of an HMAC-of-PIN proof over a 4-digit space).
// Both peers' certificate fingerprints are bound in as the SPAKE2 identities, so the
// established key — and the key-confirmation MACs derived from it — only agree when both
// sides saw the same two certificates. After mutual key confirmation the host persists the
// client's fingerprint and the client pins the host's.
// ---------------------------------------------------------------------------------------------
/// Type byte of [`PairRequest`].
pub const MSG_PAIR_REQUEST: u8 = 0x10;
/// Type byte of [`PairChallenge`].
pub const MSG_PAIR_CHALLENGE: u8 = 0x11;
/// Type byte of [`PairProof`].
pub const MSG_PAIR_PROOF: u8 = 0x12;
/// Type byte of [`PairResult`].
pub const MSG_PAIR_RESULT: u8 = 0x13;
/// `client → host`: begin pairing. `name` is the human label the host stores (≤64 bytes
/// UTF-8); `spake_a` is the client's SPAKE2 message (see [`SpakeRole::start`]).
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct PairRequest {
pub name: String,
pub spake_a: Vec<u8>,
}
/// `host → client`: the host's SPAKE2 message + its key-confirmation MAC. The client
/// finishes SPAKE2, verifies `confirm` (proving the host derived the same key, i.e. knows
/// the PIN and saw the same certs), then sends its own confirmation.
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct PairChallenge {
pub spake_b: Vec<u8>,
pub confirm: [u8; 32],
}
/// `client → host`: the client's key-confirmation MAC (its single proof attempt).
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub struct PairProof {
pub confirm: [u8; 32],
}
/// `host → client`: ceremony outcome.
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub struct PairResult {
pub ok: bool,
}
/// A length-prefixed (u16 LE) byte field within a control message.
fn put_bytes(b: &mut Vec<u8>, x: &[u8]) {
b.extend_from_slice(&(x.len() as u16).to_le_bytes());
b.extend_from_slice(x);
}
/// Read a length-prefixed field at `off`, returning the bytes and the next offset.
fn get_bytes(b: &[u8], off: usize) -> Result<(&[u8], usize)> {
if off + 2 > b.len() {
return Err(PunktfunkError::InvalidArg("truncated field"));
}
let n = u16::from_le_bytes([b[off], b[off + 1]]) as usize;
let start = off + 2;
if start + n > b.len() {
return Err(PunktfunkError::InvalidArg("field overruns message"));
}
Ok((&b[start..start + n], start + n))
}
impl PairRequest {
pub fn encode(&self) -> Vec<u8> {
let name = self.name.as_bytes();
let n = name.len().min(64);
let mut b = Vec::with_capacity(8 + n + self.spake_a.len());
b.extend_from_slice(CTL_MAGIC);
b.push(MSG_PAIR_REQUEST);
b.push(n as u8);
b.extend_from_slice(&name[..n]);
put_bytes(&mut b, &self.spake_a);
b
}
pub fn decode(b: &[u8]) -> Result<PairRequest> {
if b.len() < 6 || &b[0..4] != CTL_MAGIC || b[4] != MSG_PAIR_REQUEST {
return Err(PunktfunkError::InvalidArg("bad PairRequest"));
}
let n = b[5] as usize;
if n > 64 || b.len() < 6 + n {
return Err(PunktfunkError::InvalidArg("bad PairRequest name"));
}
let name = String::from_utf8_lossy(&b[6..6 + n]).into_owned();
let (spake_a, end) = get_bytes(b, 6 + n)?;
if end != b.len() {
return Err(PunktfunkError::InvalidArg("trailing bytes"));
}
Ok(PairRequest {
name,
spake_a: spake_a.to_vec(),
})
}
}
impl PairChallenge {
pub fn encode(&self) -> Vec<u8> {
let mut b = Vec::with_capacity(7 + self.spake_b.len() + 32);
b.extend_from_slice(CTL_MAGIC);
b.push(MSG_PAIR_CHALLENGE);
put_bytes(&mut b, &self.spake_b);
b.extend_from_slice(&self.confirm);
b
}
pub fn decode(b: &[u8]) -> Result<PairChallenge> {
if b.len() < 5 || &b[0..4] != CTL_MAGIC || b[4] != MSG_PAIR_CHALLENGE {
return Err(PunktfunkError::InvalidArg("bad PairChallenge"));
}
let (spake_b, end) = get_bytes(b, 5)?;
if end + 32 != b.len() {
return Err(PunktfunkError::InvalidArg("bad PairChallenge confirm"));
}
let mut confirm = [0u8; 32];
confirm.copy_from_slice(&b[end..end + 32]);
Ok(PairChallenge {
spake_b: spake_b.to_vec(),
confirm,
})
}
}
impl PairProof {
pub fn encode(&self) -> Vec<u8> {
let mut b = Vec::with_capacity(37);
b.extend_from_slice(CTL_MAGIC);
b.push(MSG_PAIR_PROOF);
b.extend_from_slice(&self.confirm);
b
}
pub fn decode(b: &[u8]) -> Result<PairProof> {
if b.len() != 37 || &b[0..4] != CTL_MAGIC || b[4] != MSG_PAIR_PROOF {
return Err(PunktfunkError::InvalidArg("bad PairProof"));
}
let mut confirm = [0u8; 32];
confirm.copy_from_slice(&b[5..37]);
Ok(PairProof { confirm })
}
}
impl PairResult {
pub fn encode(&self) -> Vec<u8> {
let mut b = Vec::with_capacity(6);
b.extend_from_slice(CTL_MAGIC);
b.push(MSG_PAIR_RESULT);
b.push(self.ok as u8);
b
}
pub fn decode(b: &[u8]) -> Result<PairResult> {
if b.len() != 6 || &b[0..4] != CTL_MAGIC || b[4] != MSG_PAIR_RESULT {
return Err(PunktfunkError::InvalidArg("bad PairResult"));
}
Ok(PairResult { ok: b[5] != 0 })
}
}
/// SPAKE2 over Ed25519 for the pairing ceremony. The two roles use the asymmetric flow so
/// the identities are ordered; each side binds **both** certificate fingerprints as the
/// SPAKE2 identities, so the derived key only matches when client and host agree on the PIN
/// *and* saw the same two certificates (a MITM, presenting different certs to each leg,
/// cannot reach a shared key).
pub mod pake {
use super::*;
use hmac::{Hmac, Mac};
use spake2::{Ed25519Group, Identity, Password, Spake2};
/// In-progress SPAKE2 state plus the identity transcript for key confirmation.
pub struct PairingPake {
state: Spake2<Ed25519Group>,
transcript: Vec<u8>,
}
/// Start the exchange. `client_fp`/`host_fp` are the two certificate fingerprints (the
/// client passes what it observed via TOFU; the host passes its own + the client's
/// presented cert). Returns the state and this side's outbound SPAKE2 message.
pub fn start(
is_client: bool,
pin: &str,
client_fp: &[u8; 32],
host_fp: &[u8; 32],
) -> (PairingPake, Vec<u8>) {
let pw = Password::new(pin.as_bytes());
let id_client = Identity::new(client_fp);
let id_host = Identity::new(host_fp);
let (state, msg) = if is_client {
Spake2::<Ed25519Group>::start_a(&pw, &id_client, &id_host)
} else {
Spake2::<Ed25519Group>::start_b(&pw, &id_client, &id_host)
};
let mut transcript = Vec::with_capacity(64);
transcript.extend_from_slice(client_fp);
transcript.extend_from_slice(host_fp);
(PairingPake { state, transcript }, msg)
}
/// Key confirmation MAC for one direction (`label` distinguishes host vs client), keyed
/// by the SPAKE2 shared key and bound to the fingerprint transcript.
fn confirm(key: &[u8], label: &[u8], transcript: &[u8]) -> [u8; 32] {
let mut mac =
<Hmac<sha2::Sha256> as Mac>::new_from_slice(key).expect("hmac takes any key length");
mac.update(label);
mac.update(transcript);
mac.finalize().into_bytes().into()
}
/// `Hmac` verification is constant-time via `ct_eq` in the underlying crate; we compare
/// our recomputed tag the same way.
fn ct_eq(a: &[u8; 32], b: &[u8; 32]) -> bool {
a.iter()
.zip(b.iter())
.fold(0u8, |acc, (x, y)| acc | (x ^ y))
== 0
}
/// Confirmation tags both sides expect, given the agreed SPAKE2 key.
pub struct Confirmations {
/// MAC the host sends (client verifies).
pub host: [u8; 32],
/// MAC the client sends (host verifies).
pub client: [u8; 32],
}
impl PairingPake {
/// Finish SPAKE2 with the peer's message → the pair of confirmation tags. `Err` if
/// the peer's message is malformed (a wrong PIN does NOT error here — it yields a
/// *different* key, so the confirmation MACs simply won't match).
pub fn finish(self, peer_msg: &[u8]) -> Result<Confirmations> {
let key = self
.state
.finish(peer_msg)
.map_err(|_| PunktfunkError::Crypto)?;
Ok(Confirmations {
host: confirm(&key, b"punktfunk-pair-host", &self.transcript),
client: confirm(&key, b"punktfunk-pair-client", &self.transcript),
})
}
}
/// Constant-time tag comparison for the confirmation step.
pub fn verify(expected: &[u8; 32], got: &[u8; 32]) -> bool {
ct_eq(expected, got)
}
}
/// Truncate `s` to at most `max` bytes on a UTF-8 char boundary (so a multi-byte char straddling
/// the cap is dropped whole, never split). Shared by Hello's length-prefixed name/launch fields.
fn truncate_to(s: &str, max: usize) -> &str {
if s.len() <= max {
return s;
}
let mut cut = max;
while !s.is_char_boundary(cut) {
cut -= 1;
}
&s[..cut]
}
impl Hello {
pub fn encode(&self) -> Vec<u8> {
let mut b = Vec::with_capacity(22);
b.extend_from_slice(MAGIC);
b.extend_from_slice(&self.abi_version.to_le_bytes());
b.extend_from_slice(&self.mode.width.to_le_bytes());
b.extend_from_slice(&self.mode.height.to_le_bytes());
b.extend_from_slice(&self.mode.refresh_hz.to_le_bytes());
b.push(self.compositor.to_u8()); // appended at offset 20 — older hosts read [0..20] and skip it
b.push(self.gamepad.to_u8()); // appended at offset 21 — same back-compat discipline
b.extend_from_slice(&self.bitrate_kbps.to_le_bytes()); // appended at offset 22..26
// name at offset 26: len u8 || UTF-8. Omitted when `None` *and* there is no later field —
// so a Hello with neither name nor launch stays byte-identical to the bitrate-era form
// (26 bytes). When `launch` is present we must still emit name's length byte (0 for None)
// so `launch` lands at a deterministic offset.
// `video_caps` is the last trailing field, after `launch`; when it's present (non-zero)
// the name/launch length bytes must still be emitted (0 for absent) so it lands at a
// deterministic offset — the same discipline `launch` already imposes on `name`.
let need_placeholders = self.video_caps != 0;
match (&self.name, &self.launch) {
(None, None) if !need_placeholders => {}
(name, _) => {
let n = truncate_to(name.as_deref().unwrap_or(""), HELLO_NAME_MAX);
b.push(n.len() as u8);
b.extend_from_slice(n.as_bytes());
}
}
// launch after name: len u8 || UTF-8.
if self.launch.is_some() || need_placeholders {
let l = truncate_to(self.launch.as_deref().unwrap_or(""), HELLO_LAUNCH_MAX);
b.push(l.len() as u8);
b.extend_from_slice(l.as_bytes());
}
// video_caps: single trailing byte. Last field.
if self.video_caps != 0 {
b.push(self.video_caps);
}
b
}
pub fn decode(b: &[u8]) -> Result<Hello> {
if b.len() < 20 || &b[0..4] != MAGIC {
return Err(PunktfunkError::InvalidArg("bad Hello"));
}
let u32at = |o: usize| u32::from_le_bytes([b[o], b[o + 1], b[o + 2], b[o + 3]]);
Ok(Hello {
abi_version: u32at(4),
mode: Mode {
width: u32at(8),
height: u32at(12),
refresh_hz: u32at(16),
},
// Optional trailing bytes — an older client that omits them requests `Auto`.
compositor: b
.get(20)
.map(|&v| CompositorPref::from_u8(v))
.unwrap_or_default(),
gamepad: b
.get(21)
.map(|&v| GamepadPref::from_u8(v))
.unwrap_or_default(),
// Optional trailing 4 bytes (LE) — absent on an older client → `0` (host default).
bitrate_kbps: b
.get(22..26)
.map(|s| u32::from_le_bytes(s.try_into().unwrap()))
.unwrap_or(0),
// Optional trailing device name: len u8 || UTF-8. Absent / oversized / non-UTF-8 →
// `None` (never fail the handshake over a label).
name: b.get(26).and_then(|&len| {
let len = len as usize;
if len == 0 || len > HELLO_NAME_MAX {
return None;
}
b.get(27..27 + len)
.and_then(|s| std::str::from_utf8(s).ok())
.map(String::from)
}),
// Optional trailing launch id, positioned right after name's `len u8 || UTF-8` block.
// The raw name-length byte (even when oversized/zero) determines where launch starts,
// so a corrupt name never panics — it just pushes the launch offset out of range → None.
launch: b.get(26).and_then(|&name_len| {
let off = 27 + name_len as usize; // start of launch's length byte
let len = *b.get(off)? as usize;
if len == 0 || len > HELLO_LAUNCH_MAX {
return None;
}
b.get(off + 1..off + 1 + len)
.and_then(|s| std::str::from_utf8(s).ok())
.map(String::from)
}),
// Optional trailing video-caps byte, positioned right after launch's `len u8 || bytes`
// block. Uses the raw (possibly zero/placeholder) name/launch length bytes to locate it,
// so it's robust to absent name/launch; absent entirely on an older client → `0`.
video_caps: {
let name_len = b.get(26).copied().unwrap_or(0) as usize;
let launch_off = 27 + name_len; // launch's length byte
let launch_len = b.get(launch_off).copied().unwrap_or(0) as usize;
b.get(launch_off + 1 + launch_len).copied().unwrap_or(0)
},
})
}
}
impl Welcome {
pub fn encode(&self) -> Vec<u8> {
let mut b = Vec::with_capacity(64);
b.extend_from_slice(MAGIC);
b.extend_from_slice(&self.abi_version.to_le_bytes());
b.extend_from_slice(&self.udp_port.to_le_bytes());
b.extend_from_slice(&self.mode.width.to_le_bytes());
b.extend_from_slice(&self.mode.height.to_le_bytes());
b.extend_from_slice(&self.mode.refresh_hz.to_le_bytes());
b.push(match self.fec.scheme {
FecScheme::Gf8 => 0,
FecScheme::Gf16 => 1,
});
b.push(self.fec.fec_percent);
b.extend_from_slice(&self.fec.max_data_per_block.to_le_bytes());
b.extend_from_slice(&self.shard_payload.to_le_bytes());
b.push(self.encrypt as u8);
b.extend_from_slice(&self.key);
b.extend_from_slice(&self.salt);
b.extend_from_slice(&self.frames.to_le_bytes());
b.push(self.compositor.to_u8()); // appended at offset 53 — older clients read [0..53] and skip it
b.push(self.gamepad.to_u8()); // appended at offset 54 — same back-compat discipline
b.extend_from_slice(&self.bitrate_kbps.to_le_bytes()); // appended at offset 55..59
b.push(self.bit_depth); // appended at offset 59 — older clients read [0..59] and skip it
// Colour signalling at offsets 60..64 — older clients stop before these → SDR BT.709.
b.push(self.color.primaries);
b.push(self.color.transfer);
b.push(self.color.matrix);
b.push(self.color.full_range);
b
}
pub fn decode(b: &[u8]) -> Result<Welcome> {
// Layout (LE): magic[0..4] abi[4..8] port[8..10] w[10..14] h[14..18] hz[18..22]
// scheme[22] pct[23] max_data[24..26] shard[26..28] encrypt[28] key[29..45]
// salt[45..49] frames[49..53] compositor[53] gamepad[54] bitrate_kbps[55..59]
// bit_depth[59] color.primaries[60] color.transfer[61] color.matrix[62] color.range[63]
// (everything from compositor on is an optional trailing byte; an older host stops earlier).
if b.len() < 53 || &b[0..4] != MAGIC {
return Err(PunktfunkError::InvalidArg("bad Welcome"));
}
let u32at = |o: usize| u32::from_le_bytes([b[o], b[o + 1], b[o + 2], b[o + 3]]);
let u16at = |o: usize| u16::from_le_bytes([b[o], b[o + 1]]);
let mut key = [0u8; 16];
key.copy_from_slice(&b[29..45]);
let mut salt = [0u8; 4];
salt.copy_from_slice(&b[45..49]);
Ok(Welcome {
abi_version: u32at(4),
udp_port: u16at(8),
mode: Mode {
width: u32at(10),
height: u32at(14),
refresh_hz: u32at(18),
},
fec: FecConfig {
scheme: if b[22] == 1 {
FecScheme::Gf16
} else {
FecScheme::Gf8
},
fec_percent: b[23],
max_data_per_block: u16at(24),
},
shard_payload: u16at(26),
encrypt: b[28] != 0,
key,
salt,
frames: u32at(49),
// Optional trailing bytes — an older host that omits them leaves the resolved
// compositor / gamepad backend unknown (`Auto`).
compositor: b
.get(53)
.map(|&v| CompositorPref::from_u8(v))
.unwrap_or_default(),
gamepad: b
.get(54)
.map(|&v| GamepadPref::from_u8(v))
.unwrap_or_default(),
// Optional trailing 4 bytes (LE) — absent on an older host → `0` (unknown).
bitrate_kbps: b
.get(55..59)
.map(|s| u32::from_le_bytes(s.try_into().unwrap()))
.unwrap_or(0),
// Optional trailing byte — absent on an older host → `8` (8-bit, the only depth they
// encode).
bit_depth: b.get(59).copied().unwrap_or(8),
// Optional trailing colour bytes — absent on an older host → SDR BT.709 limited.
color: ColorInfo {
primaries: b.get(60).copied().unwrap_or(ColorInfo::CP_BT709),
transfer: b.get(61).copied().unwrap_or(ColorInfo::TRC_BT709),
matrix: b.get(62).copied().unwrap_or(ColorInfo::MC_BT709),
full_range: b.get(63).copied().unwrap_or(0),
},
})
}
/// Build the data-plane [`Config`] this offer describes (for `role`).
pub fn session_config(&self, role: Role) -> Config {
let mut c = Config::p1_defaults(role);
c.phase = ProtocolPhase::P1GameStream; // wire phase id pending the P2 packet rev
c.fec = self.fec;
c.shard_payload = self.shard_payload as usize;
c.encrypt = self.encrypt;
c.key = self.key;
c.salt = self.salt;
c
}
}
impl Start {
pub fn encode(&self) -> Vec<u8> {
let mut b = Vec::with_capacity(6);
b.extend_from_slice(MAGIC);
b.extend_from_slice(&self.client_udp_port.to_le_bytes());
b
}
pub fn decode(b: &[u8]) -> Result<Start> {
if b.len() < 6 || &b[0..4] != MAGIC {
return Err(PunktfunkError::InvalidArg("bad Start"));
}
Ok(Start {
client_udp_port: u16::from_le_bytes([b[4], b[5]]),
})
}
}
impl Reconfigure {
pub fn encode(&self) -> Vec<u8> {
// magic[0..4] type[4] w[5..9] h[9..13] hz[13..17]
let mut b = Vec::with_capacity(17);
b.extend_from_slice(CTL_MAGIC);
b.push(MSG_RECONFIGURE);
b.extend_from_slice(&self.mode.width.to_le_bytes());
b.extend_from_slice(&self.mode.height.to_le_bytes());
b.extend_from_slice(&self.mode.refresh_hz.to_le_bytes());
b
}
pub fn decode(b: &[u8]) -> Result<Reconfigure> {
if b.len() != 17 || &b[0..4] != CTL_MAGIC || b[4] != MSG_RECONFIGURE {
return Err(PunktfunkError::InvalidArg("bad Reconfigure"));
}
let u32at = |o: usize| u32::from_le_bytes([b[o], b[o + 1], b[o + 2], b[o + 3]]);
Ok(Reconfigure {
mode: Mode {
width: u32at(5),
height: u32at(9),
refresh_hz: u32at(13),
},
})
}
}
impl Reconfigured {
pub fn encode(&self) -> Vec<u8> {
// magic[0..4] type[4] accepted[5] w[6..10] h[10..14] hz[14..18]
let mut b = Vec::with_capacity(18);
b.extend_from_slice(CTL_MAGIC);
b.push(MSG_RECONFIGURED);
b.push(self.accepted as u8);
b.extend_from_slice(&self.mode.width.to_le_bytes());
b.extend_from_slice(&self.mode.height.to_le_bytes());
b.extend_from_slice(&self.mode.refresh_hz.to_le_bytes());
b
}
pub fn decode(b: &[u8]) -> Result<Reconfigured> {
if b.len() != 18 || &b[0..4] != CTL_MAGIC || b[4] != MSG_RECONFIGURED {
return Err(PunktfunkError::InvalidArg("bad Reconfigured"));
}
let u32at = |o: usize| u32::from_le_bytes([b[o], b[o + 1], b[o + 2], b[o + 3]]);
Ok(Reconfigured {
accepted: b[5] != 0,
mode: Mode {
width: u32at(6),
height: u32at(10),
refresh_hz: u32at(14),
},
})
}
}
impl RequestKeyframe {
pub fn encode(&self) -> Vec<u8> {
// magic[0..4] type[4] — no payload
let mut b = Vec::with_capacity(5);
b.extend_from_slice(CTL_MAGIC);
b.push(MSG_REQUEST_KEYFRAME);
b
}
pub fn decode(b: &[u8]) -> Result<RequestKeyframe> {
if b.len() != 5 || &b[0..4] != CTL_MAGIC || b[4] != MSG_REQUEST_KEYFRAME {
return Err(PunktfunkError::InvalidArg("bad RequestKeyframe"));
}
Ok(RequestKeyframe)
}
}
impl LossReport {
pub fn encode(&self) -> Vec<u8> {
// magic[0..4] type[4] loss_ppm[5..9]
let mut b = Vec::with_capacity(9);
b.extend_from_slice(CTL_MAGIC);
b.push(MSG_LOSS_REPORT);
b.extend_from_slice(&self.loss_ppm.to_le_bytes());
b
}
pub fn decode(b: &[u8]) -> Result<LossReport> {
if b.len() != 9 || &b[0..4] != CTL_MAGIC || b[4] != MSG_LOSS_REPORT {
return Err(PunktfunkError::InvalidArg("bad LossReport"));
}
Ok(LossReport {
loss_ppm: u32::from_le_bytes(b[5..9].try_into().unwrap()),
})
}
}
/// Compute a [`LossReport`] `loss_ppm` from one window's session-stat deltas: shards FEC recovered
/// (the loss it absorbed), shards received, and frames that went unrecoverable. Loss ≈ recovered /
/// (received + recovered) — the fraction of shards that arrived missing. A frame drop means loss
/// exceeded the current FEC budget (so `recovered` plateaus), so add a fixed bump to push the host's
/// FEC up past the cap on the next adjustment. Returns parts-per-million, capped at 1e6.
pub fn window_loss_ppm(recovered: u64, received: u64, frames_dropped: u64) -> u32 {
let denom = received.saturating_add(recovered);
let mut ppm = recovered
.saturating_mul(1_000_000)
.checked_div(denom)
.unwrap_or(0) as u32;
if frames_dropped > 0 {
ppm = ppm.saturating_add(50_000); // +5%: unrecoverable loss → raise FEC past the current cap
}
ppm.min(1_000_000)
}
impl ProbeRequest {
pub fn encode(&self) -> Vec<u8> {
// magic[0..4] type[4] target_kbps[5..9] duration_ms[9..13]
let mut b = Vec::with_capacity(13);
b.extend_from_slice(CTL_MAGIC);
b.push(MSG_PROBE_REQUEST);
b.extend_from_slice(&self.target_kbps.to_le_bytes());
b.extend_from_slice(&self.duration_ms.to_le_bytes());
b
}
pub fn decode(b: &[u8]) -> Result<ProbeRequest> {
if b.len() != 13 || &b[0..4] != CTL_MAGIC || b[4] != MSG_PROBE_REQUEST {
return Err(PunktfunkError::InvalidArg("bad ProbeRequest"));
}
let u32at = |o: usize| u32::from_le_bytes([b[o], b[o + 1], b[o + 2], b[o + 3]]);
Ok(ProbeRequest {
target_kbps: u32at(5),
duration_ms: u32at(9),
})
}
}
impl ProbeResult {
pub fn encode(&self) -> Vec<u8> {
// magic[0..4] type[4] bytes_sent[5..13] packets_sent[13..17] duration_ms[17..21]
// wire_packets_sent[21..25] send_dropped[25..29]
let mut b = Vec::with_capacity(29);
b.extend_from_slice(CTL_MAGIC);
b.push(MSG_PROBE_RESULT);
b.extend_from_slice(&self.bytes_sent.to_le_bytes());
b.extend_from_slice(&self.packets_sent.to_le_bytes());
b.extend_from_slice(&self.duration_ms.to_le_bytes());
b.extend_from_slice(&self.wire_packets_sent.to_le_bytes());
b.extend_from_slice(&self.send_dropped.to_le_bytes());
b
}
pub fn decode(b: &[u8]) -> Result<ProbeResult> {
// Back-compat: 21 bytes (pre-wire-stats host, new fields default 0) or 29 bytes (with the
// wire_packets_sent + send_dropped tail). Accept either; reject anything shorter/garbled.
if b.len() < 21 || &b[0..4] != CTL_MAGIC || b[4] != MSG_PROBE_RESULT {
return Err(PunktfunkError::InvalidArg("bad ProbeResult"));
}
let u32at = |o: usize| u32::from_le_bytes([b[o], b[o + 1], b[o + 2], b[o + 3]]);
let (wire_packets_sent, send_dropped) = if b.len() >= 29 {
(u32at(21), u32at(25))
} else {
(0, 0)
};
Ok(ProbeResult {
bytes_sent: u64::from_le_bytes(b[5..13].try_into().unwrap()),
packets_sent: u32at(13),
duration_ms: u32at(17),
wire_packets_sent,
send_dropped,
})
}
}
impl ClockProbe {
pub fn encode(&self) -> Vec<u8> {
// magic[0..4] type[4] t1[5..13]
let mut b = Vec::with_capacity(13);
b.extend_from_slice(CTL_MAGIC);
b.push(MSG_CLOCK_PROBE);
b.extend_from_slice(&self.t1_ns.to_le_bytes());
b
}
pub fn decode(b: &[u8]) -> Result<ClockProbe> {
if b.len() != 13 || &b[0..4] != CTL_MAGIC || b[4] != MSG_CLOCK_PROBE {
return Err(PunktfunkError::InvalidArg("bad ClockProbe"));
}
Ok(ClockProbe {
t1_ns: u64::from_le_bytes(b[5..13].try_into().unwrap()),
})
}
}
impl ClockEcho {
pub fn encode(&self) -> Vec<u8> {
// magic[0..4] type[4] t1[5..13] t2[13..21] t3[21..29]
let mut b = Vec::with_capacity(29);
b.extend_from_slice(CTL_MAGIC);
b.push(MSG_CLOCK_ECHO);
b.extend_from_slice(&self.t1_ns.to_le_bytes());
b.extend_from_slice(&self.t2_ns.to_le_bytes());
b.extend_from_slice(&self.t3_ns.to_le_bytes());
b
}
pub fn decode(b: &[u8]) -> Result<ClockEcho> {
if b.len() != 29 || &b[0..4] != CTL_MAGIC || b[4] != MSG_CLOCK_ECHO {
return Err(PunktfunkError::InvalidArg("bad ClockEcho"));
}
Ok(ClockEcho {
t1_ns: u64::from_le_bytes(b[5..13].try_into().unwrap()),
t2_ns: u64::from_le_bytes(b[13..21].try_into().unwrap()),
t3_ns: u64::from_le_bytes(b[21..29].try_into().unwrap()),
})
}
}
/// Frame a message for the control stream: `u16 LE length || payload`.
pub fn frame(payload: &[u8]) -> Vec<u8> {
let mut b = Vec::with_capacity(2 + payload.len());
b.extend_from_slice(&(payload.len() as u16).to_le_bytes());
b.extend_from_slice(payload);
b
}
/// Datagram wire tags. Video rides UDP; everything low-rate rides QUIC datagrams,
/// demultiplexed by the first byte: input = [`crate::input::INPUT_MAGIC`] (0xC8, client→host),
/// audio = [`AUDIO_MAGIC`] (0xC9, host→client), rumble = [`RUMBLE_MAGIC`] (0xCA, host→client),
/// mic = [`MIC_MAGIC`] (0xCB, client→host), rich-input = [`RICH_INPUT_MAGIC`] (0xCC, client→host),
/// HID-output = [`HIDOUT_MAGIC`] (0xCD, host→client), HDR metadata = [`HDR_META_MAGIC`]
/// (0xCE, host→client).
pub const AUDIO_MAGIC: u8 = 0xC9;
pub const RUMBLE_MAGIC: u8 = 0xCA;
/// Microphone uplink: the client's mic, Opus-encoded, client → host (the inverse of
/// [`AUDIO_MAGIC`]). The host feeds it into a virtual PipeWire source so its apps can record it.
pub const MIC_MAGIC: u8 = 0xCB;
/// Rich client→host input: events too big for the fixed 18-byte [`InputEvent`]
/// (crate::input::InputEvent) — the DualSense touchpad and motion sensors. Variable-length,
/// kind-tagged (see [`RichInput`]).
pub const RICH_INPUT_MAGIC: u8 = 0xCC;
/// HID output, host → client: DualSense feedback a game wrote to the host's virtual controller
/// (lightbar, player LEDs, adaptive triggers) — the rich analog of [`RUMBLE_MAGIC`]. See
/// [`HidOutput`].
pub const HIDOUT_MAGIC: u8 = 0xCD;
/// Audio datagram, host → client: `[0xC9][u32 seq LE][u64 pts_ns LE][opus payload]`.
/// One Opus frame per datagram (5 ms — well under any MTU); QUIC already encrypts.
pub fn encode_audio_datagram(seq: u32, pts_ns: u64, opus: &[u8]) -> Vec<u8> {
let mut b = Vec::with_capacity(13 + opus.len());
b.push(AUDIO_MAGIC);
b.extend_from_slice(&seq.to_le_bytes());
b.extend_from_slice(&pts_ns.to_le_bytes());
b.extend_from_slice(opus);
b
}
/// Parse an audio datagram → `(seq, pts_ns, opus payload)`. `None` on bad tag/length.
pub fn decode_audio_datagram(b: &[u8]) -> Option<(u32, u64, &[u8])> {
if b.len() < 13 || b[0] != AUDIO_MAGIC {
return None;
}
let seq = u32::from_le_bytes(b[1..5].try_into().unwrap());
let pts_ns = u64::from_le_bytes(b[5..13].try_into().unwrap());
Some((seq, pts_ns, &b[13..]))
}
/// Rumble datagram, host → client: `[0xCA][u16 pad LE][u16 low LE][u16 high LE]`.
/// Force-feedback state for pad `pad` (0xFFFF amplitudes, 0/0 = stop).
pub fn encode_rumble_datagram(pad: u16, low: u16, high: u16) -> [u8; 7] {
let mut b = [0u8; 7];
b[0] = RUMBLE_MAGIC;
b[1..3].copy_from_slice(&pad.to_le_bytes());
b[3..5].copy_from_slice(&low.to_le_bytes());
b[5..7].copy_from_slice(&high.to_le_bytes());
b
}
/// Parse a rumble datagram → `(pad, low, high)`. `None` on bad tag/length.
pub fn decode_rumble_datagram(b: &[u8]) -> Option<(u16, u16, u16)> {
if b.len() < 7 || b[0] != RUMBLE_MAGIC {
return None;
}
let u16at = |o: usize| u16::from_le_bytes([b[o], b[o + 1]]);
Some((u16at(1), u16at(3), u16at(5)))
}
/// Mic datagram, client → host: `[0xCB][u32 seq LE][u64 pts_ns LE][opus payload]` — the same
/// layout as [`encode_audio_datagram`] with [`MIC_MAGIC`], one Opus frame per datagram.
pub fn encode_mic_datagram(seq: u32, pts_ns: u64, opus: &[u8]) -> Vec<u8> {
let mut b = Vec::with_capacity(13 + opus.len());
b.push(MIC_MAGIC);
b.extend_from_slice(&seq.to_le_bytes());
b.extend_from_slice(&pts_ns.to_le_bytes());
b.extend_from_slice(opus);
b
}
/// Parse a mic datagram → `(seq, pts_ns, opus payload)`. `None` on bad tag/length.
pub fn decode_mic_datagram(b: &[u8]) -> Option<(u32, u64, &[u8])> {
if b.len() < 13 || b[0] != MIC_MAGIC {
return None;
}
let seq = u32::from_le_bytes(b[1..5].try_into().unwrap());
let pts_ns = u64::from_le_bytes(b[5..13].try_into().unwrap());
Some((seq, pts_ns, &b[13..]))
}
const RICH_TOUCHPAD: u8 = 0x01;
const RICH_MOTION: u8 = 0x02;
/// A rich client→host controller input beyond the fixed [`InputEvent`](crate::input::InputEvent):
/// the DualSense touchpad and motion sensors. `pad` is the gamepad index. Wire form is
/// `[0xCC][kind][fields…]` — variable-length and kind-tagged (forward-compatible: an unknown
/// kind decodes to `None` and is dropped).
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub enum RichInput {
/// One touchpad contact. `x`/`y` are normalized `0..=65535` (the host scales to the
/// DualSense touchpad resolution); `active = false` lifts the finger.
Touchpad {
pad: u8,
finger: u8,
active: bool,
x: u16,
y: u16,
},
/// Motion sensors: `gyro` (pitch/yaw/roll) + `accel`, raw signed-16 in the sensor's own
/// units — passed straight into the DualSense report.
Motion {
pad: u8,
gyro: [i16; 3],
accel: [i16; 3],
},
}
impl RichInput {
pub fn encode(&self) -> Vec<u8> {
let mut out = vec![RICH_INPUT_MAGIC];
match *self {
RichInput::Touchpad {
pad,
finger,
active,
x,
y,
} => {
out.extend_from_slice(&[RICH_TOUCHPAD, pad, finger, active as u8]);
out.extend_from_slice(&x.to_le_bytes());
out.extend_from_slice(&y.to_le_bytes());
}
RichInput::Motion { pad, gyro, accel } => {
out.extend_from_slice(&[RICH_MOTION, pad]);
for v in gyro.iter().chain(accel.iter()) {
out.extend_from_slice(&v.to_le_bytes());
}
}
}
out
}
pub fn decode(b: &[u8]) -> Option<RichInput> {
if b.first() != Some(&RICH_INPUT_MAGIC) {
return None;
}
match *b.get(1)? {
RICH_TOUCHPAD if b.len() >= 9 => Some(RichInput::Touchpad {
pad: b[2],
finger: b[3],
active: b[4] != 0,
x: u16::from_le_bytes([b[5], b[6]]),
y: u16::from_le_bytes([b[7], b[8]]),
}),
RICH_MOTION if b.len() >= 15 => {
let i16at = |o: usize| i16::from_le_bytes([b[o], b[o + 1]]);
Some(RichInput::Motion {
pad: b[2],
gyro: [i16at(3), i16at(5), i16at(7)],
accel: [i16at(9), i16at(11), i16at(13)],
})
}
_ => None,
}
}
}
const HIDOUT_LED: u8 = 0x01;
const HIDOUT_PLAYER_LEDS: u8 = 0x02;
const HIDOUT_TRIGGER: u8 = 0x03;
/// DualSense feedback flowing host → client (what a game wrote to the host's virtual pad).
/// Wire form `[0xCD][kind][pad][fields…]`. The rich analog of the fixed rumble datagram;
/// rumble itself stays on [`RUMBLE_MAGIC`].
#[derive(Clone, Debug, PartialEq, Eq)]
pub enum HidOutput {
/// Lightbar RGB.
Led { pad: u8, r: u8, g: u8, b: u8 },
/// Player-indicator LEDs (low 5 bits).
PlayerLeds { pad: u8, bits: u8 },
/// One adaptive-trigger effect: `which` 0 = L2, 1 = R2; `effect` is the raw DualSense
/// trigger parameter block (mode + params) for the client to replay on a real controller.
Trigger { pad: u8, which: u8, effect: Vec<u8> },
}
impl HidOutput {
pub fn encode(&self) -> Vec<u8> {
let mut out = vec![HIDOUT_MAGIC];
match self {
HidOutput::Led { pad, r, g, b } => {
out.extend_from_slice(&[HIDOUT_LED, *pad, *r, *g, *b])
}
HidOutput::PlayerLeds { pad, bits } => {
out.extend_from_slice(&[HIDOUT_PLAYER_LEDS, *pad, *bits])
}
HidOutput::Trigger { pad, which, effect } => {
out.extend_from_slice(&[HIDOUT_TRIGGER, *pad, *which]);
out.extend_from_slice(effect);
}
}
out
}
pub fn decode(b: &[u8]) -> Option<HidOutput> {
if b.first() != Some(&HIDOUT_MAGIC) {
return None;
}
match *b.get(1)? {
HIDOUT_LED if b.len() >= 6 => Some(HidOutput::Led {
pad: b[2],
r: b[3],
g: b[4],
b: b[5],
}),
HIDOUT_PLAYER_LEDS if b.len() >= 4 => Some(HidOutput::PlayerLeds {
pad: b[2],
bits: b[3],
}),
HIDOUT_TRIGGER if b.len() >= 4 => Some(HidOutput::Trigger {
pad: b[2],
which: b[3],
effect: b[4..].to_vec(),
}),
_ => None,
}
}
}
/// Static HDR metadata, host → client: SMPTE ST.2086 mastering display colour volume + CEA-861.3
/// content light level. Tag [`HDR_META_MAGIC`]. Carried on a datagram (not [`Welcome`]) because it
/// is larger and can change mid-stream when the source's mastering intent changes; the host
/// re-sends it on keyframes so a client that dropped the best-effort datagram converges. Omitted
/// for HLG (scene-referred — no mastering metadata).
///
/// All fields use the standard HDR10 SEI fixed-point units, so they pass straight to
/// `DXGI_HDR_METADATA_HDR10` / Android `KEY_HDR_STATIC_INFO` / Apple `CAEDRMetadata` — the
/// libavcodec `AVMasteringDisplayMetadata` side needs an `AVRational` conversion.
#[derive(Clone, Copy, Debug, PartialEq, Eq, Default)]
pub struct HdrMeta {
/// Display primaries G, B, R as (x, y) chromaticity in 1/50000 units (the ST.2086 RGB order
/// is G, B, R).
pub display_primaries: [[u16; 2]; 3],
/// White point (x, y) in 1/50000 units.
pub white_point: [u16; 2],
/// Max display mastering luminance, 0.0001 cd/m² units.
pub max_display_mastering_luminance: u32,
/// Min display mastering luminance, 0.0001 cd/m² units.
pub min_display_mastering_luminance: u32,
/// Maximum content light level (MaxCLL), nits. `0` = unknown.
pub max_cll: u16,
/// Maximum frame-average light level (MaxFALL), nits. `0` = unknown.
pub max_fall: u16,
}
/// HDR static-metadata datagram tag, host → client (the static analog of the per-frame VUI;
/// see [`HdrMeta`]). Next tag after [`HIDOUT_MAGIC`].
pub const HDR_META_MAGIC: u8 = 0xCE;
/// Wire length of an [`HDR_META_MAGIC`] datagram: tag + 6×u16 primaries + 2×u16 white + 2×u32
/// luminance + 2×u16 CLL/FALL = 29 bytes.
const HDR_META_LEN: usize = 1 + 12 + 4 + 8 + 4;
/// Encode an [`HdrMeta`] into a [`HDR_META_MAGIC`] datagram.
pub fn encode_hdr_meta_datagram(m: &HdrMeta) -> Vec<u8> {
let mut b = Vec::with_capacity(HDR_META_LEN);
b.push(HDR_META_MAGIC);
for p in m.display_primaries.iter() {
b.extend_from_slice(&p[0].to_le_bytes());
b.extend_from_slice(&p[1].to_le_bytes());
}
b.extend_from_slice(&m.white_point[0].to_le_bytes());
b.extend_from_slice(&m.white_point[1].to_le_bytes());
b.extend_from_slice(&m.max_display_mastering_luminance.to_le_bytes());
b.extend_from_slice(&m.min_display_mastering_luminance.to_le_bytes());
b.extend_from_slice(&m.max_cll.to_le_bytes());
b.extend_from_slice(&m.max_fall.to_le_bytes());
b
}
/// Parse a [`HDR_META_MAGIC`] datagram → [`HdrMeta`]. `None` on bad tag or a short/truncated buffer
/// (every attacker-controlled field is bounds-checked by the fixed length before any read).
pub fn decode_hdr_meta_datagram(b: &[u8]) -> Option<HdrMeta> {
if b.len() < HDR_META_LEN || b[0] != HDR_META_MAGIC {
return None;
}
let u16at = |o: usize| u16::from_le_bytes([b[o], b[o + 1]]);
let u32at = |o: usize| u32::from_le_bytes([b[o], b[o + 1], b[o + 2], b[o + 3]]);
Some(HdrMeta {
display_primaries: [
[u16at(1), u16at(3)],
[u16at(5), u16at(7)],
[u16at(9), u16at(11)],
],
white_point: [u16at(13), u16at(15)],
max_display_mastering_luminance: u32at(17),
min_display_mastering_luminance: u32at(21),
max_cll: u16at(25),
max_fall: u16at(27),
})
}
/// Async framed-message IO over a quinn stream (`u16 LE length || payload`).
pub mod io {
/// Read one framed message (bounded at 64 KiB — control messages are tiny).
pub async fn read_msg(recv: &mut quinn::RecvStream) -> std::io::Result<Vec<u8>> {
let mut len = [0u8; 2];
recv.read_exact(&mut len)
.await
.map_err(std::io::Error::other)?;
let n = u16::from_le_bytes(len) as usize;
let mut buf = vec![0u8; n];
recv.read_exact(&mut buf)
.await
.map_err(std::io::Error::other)?;
Ok(buf)
}
/// Write one framed message.
pub async fn write_msg(send: &mut quinn::SendStream, payload: &[u8]) -> std::io::Result<()> {
send.write_all(&super::frame(payload))
.await
.map_err(std::io::Error::other)
}
}
/// One wall-clock skew-handshake outcome (see [`clock_sync`]).
pub struct ClockSkew {
/// Host clock minus client clock, ns: add it to a client timestamp to express it in host time.
pub offset_ns: i64,
/// Round-trip time of the minimum-RTT sample, ns.
pub rtt_ns: u64,
/// How many probe rounds the host answered.
pub rounds: usize,
}
/// Run the wall-clock skew handshake from the client side over the (already-open) control stream:
/// `ROUNDS` [`ClockProbe`]/[`ClockEcho`] round-trips, returning the host↔client offset from the
/// minimum-RTT sample. `None` if the host never answers (an old host) — the caller then assumes a
/// shared clock. Each read is bounded so a silent host can't wedge session start. Shared by the
/// reference client and the embeddable connector; uses the realtime clock the host stamps `pts_ns`
/// with, so the offset aligns a client receive instant to the host's capture clock.
pub async fn clock_sync(
send: &mut quinn::SendStream,
recv: &mut quinn::RecvStream,
) -> Option<ClockSkew> {
use std::time::{Duration, SystemTime, UNIX_EPOCH};
fn now_ns() -> u64 {
SystemTime::now()
.duration_since(UNIX_EPOCH)
.map(|d| d.as_nanos() as u64)
.unwrap_or(0)
}
const ROUNDS: usize = 8;
let read_timeout = Duration::from_secs(2);
let mut samples: Vec<(u64, u64, u64, u64)> = Vec::with_capacity(ROUNDS);
for _ in 0..ROUNDS {
let t1 = now_ns();
let probe = ClockProbe { t1_ns: t1 }.encode();
if io::write_msg(send, &probe).await.is_err() {
break;
}
let read = tokio::time::timeout(read_timeout, io::read_msg(recv)).await;
let echo = match read {
Ok(Ok(b)) => match ClockEcho::decode(&b) {
Ok(e) => e,
Err(_) => break,
},
_ => break, // timeout or stream error -> old host / no skew support
};
samples.push((echo.t1_ns, echo.t2_ns, echo.t3_ns, now_ns()));
}
clock_offset_ns(&samples).map(|(offset_ns, rtt_ns)| ClockSkew {
offset_ns,
rtt_ns,
rounds: samples.len(),
})
}
/// quinn endpoint constructors. Host: self-signed identity (fresh, or persisted PEMs via
/// [`endpoint::server_with_identity`]). Client: fingerprint pinning / TOFU via
/// [`endpoint::client_pinned`] ([`endpoint::client_insecure`] is the no-pin special case).
pub mod endpoint {
use std::sync::{Arc, Mutex};
/// Shared QUIC transport tuning for BOTH the host and client endpoints. Keep-alive is the
/// load-bearing setting: with quinn's defaults it is OFF, so any quiet stretch on the
/// connection (no input, audio muted or stalled, a capture hiccup, a mode change) lets the
/// idle timer run out and quinn closes the session — surfacing to the embedder as
/// `next_au` → Closed. The native equivalent of Moonlight's ENet keepalive: a small PING
/// every `KEEP_ALIVE` keeps the path warm. The interval sits well under `MAX_IDLE` so
/// several keepalives can be lost back-to-back (a wifi roam, a brief blip) without a false
/// close, while a genuinely dead peer is still detected within `MAX_IDLE`.
fn stream_transport() -> Arc<quinn::TransportConfig> {
use std::time::Duration;
const MAX_IDLE: Duration = Duration::from_secs(20);
const KEEP_ALIVE: Duration = Duration::from_secs(4);
let mut t = quinn::TransportConfig::default();
t.max_idle_timeout(Some(
quinn::IdleTimeout::try_from(MAX_IDLE).expect("20s is a valid QUIC idle timeout"),
));
t.keep_alive_interval(Some(KEEP_ALIVE));
Arc::new(t)
}
/// Server endpoint with a fresh self-signed certificate (tests/dev — production hosts
/// persist an identity and use [`server_with_identity`] so clients can pin it).
pub fn server(addr: std::net::SocketAddr) -> anyhow_result::Result<quinn::Endpoint> {
let cert = rcgen::generate_simple_self_signed(vec!["punktfunk".into()])
.map_err(|e| anyhow_result::Error::msg(format!("self-signed cert: {e}")))?;
let cert_der = rustls::pki_types::CertificateDer::from(cert.cert);
let key_der = rustls::pki_types::PrivatePkcs8KeyDer::from(cert.key_pair.serialize_der());
server_from_der(cert_der, key_der.into(), addr)
}
/// Server endpoint from a persisted PEM identity (certificate + PKCS#8 private key) —
/// the host's long-lived self-signed cert, so the fingerprint clients pin is stable
/// across restarts.
pub fn server_with_identity(
addr: std::net::SocketAddr,
cert_pem: &str,
key_pem: &str,
) -> anyhow_result::Result<quinn::Endpoint> {
use rustls::pki_types::pem::PemObject;
let cert_der = rustls::pki_types::CertificateDer::from_pem_slice(cert_pem.as_bytes())
.map_err(|e| anyhow_result::Error::msg(format!("cert pem: {e}")))?;
let key_der = rustls::pki_types::PrivateKeyDer::from_pem_slice(key_pem.as_bytes())
.map_err(|e| anyhow_result::Error::msg(format!("key pem: {e}")))?;
server_from_der(cert_der, key_der, addr)
}
/// Fixed ALPN for the punktfunk/1 QUIC handshake. Pinning it rejects a cross-protocol peer at the
/// TLS layer (defense-in-depth) and makes the wire protocol explicit. Both ends set the SAME value;
/// a host with ALPN configured rejects a client that offers none, so client + host must be updated
/// together (acceptable while the protocol/ABI is still evolving).
const QUIC_ALPN: &[u8] = b"pkf1";
fn server_from_der(
cert_der: rustls::pki_types::CertificateDer<'static>,
key_der: rustls::pki_types::PrivateKeyDer<'static>,
addr: std::net::SocketAddr,
) -> anyhow_result::Result<quinn::Endpoint> {
let _ = rustls::crypto::ring::default_provider().install_default();
// Client auth is OFFERED but optional: a client that presents its self-signed
// identity is fingerprinted post-handshake (pairing / --require-pairing checks);
// one that presents none still connects (and is rejected at the app layer when
// pairing is required).
let mut rustls_cfg = rustls::ServerConfig::builder()
.with_client_cert_verifier(Arc::new(AcceptAnyClientCert))
.with_single_cert(vec![cert_der], key_der)
.map_err(|e| anyhow_result::Error::msg(format!("server config: {e}")))?;
rustls_cfg.alpn_protocols = vec![QUIC_ALPN.to_vec()];
let quic_cfg = quinn::crypto::rustls::QuicServerConfig::try_from(rustls_cfg)
.map_err(|e| anyhow_result::Error::msg(format!("quic server config: {e}")))?;
let mut server_config = quinn::ServerConfig::with_crypto(Arc::new(quic_cfg));
server_config.transport_config(stream_transport()); // keep-alive — see stream_transport
Ok(quinn::Endpoint::server(server_config, addr)?)
}
/// Generate a fresh self-signed identity (certificate + PKCS#8 key, both PEM) — what a
/// client persists once and presents on every connect so hosts can recognize it.
pub fn generate_identity() -> anyhow_result::Result<(String, String)> {
let cert = rcgen::generate_simple_self_signed(vec!["punktfunk-client".into()])
.map_err(|e| anyhow_result::Error::msg(format!("self-signed cert: {e}")))?;
Ok((cert.cert.pem(), cert.key_pair.serialize_pem()))
}
/// Fingerprint of the client certificate a connection presented (host side), if any.
pub fn peer_fingerprint(conn: &quinn::Connection) -> Option<[u8; 32]> {
let identity = conn.peer_identity()?;
let certs = identity
.downcast::<Vec<rustls::pki_types::CertificateDer<'static>>>()
.ok()?;
certs.first().map(|c| cert_fingerprint(c.as_ref()))
}
/// SHA-256 of a certificate's DER encoding — the fingerprint clients pin.
pub fn cert_fingerprint(cert_der: &[u8]) -> [u8; 32] {
use sha2::Digest;
sha2::Sha256::digest(cert_der).into()
}
/// Fingerprint of a PEM-encoded certificate (what a host logs/shows for pairing UX —
/// must match what the client's verifier computes from the DER on the wire).
pub fn fingerprint_of_pem(cert_pem: &str) -> anyhow_result::Result<[u8; 32]> {
use rustls::pki_types::pem::PemObject;
let der = rustls::pki_types::CertificateDer::from_pem_slice(cert_pem.as_bytes())
.map_err(|e| anyhow_result::Error::msg(format!("cert pem: {e}")))?;
Ok(cert_fingerprint(der.as_ref()))
}
/// Client endpoint that skips certificate verification (TOFU bootstrap — read the
/// observed fingerprint off the slot and pin it on the next connect).
pub fn client_insecure() -> anyhow_result::Result<quinn::Endpoint> {
client_pinned(None).0
}
/// What [`client_pinned`] returns: the endpoint plus the slot the verifier writes the
/// observed host fingerprint into during the handshake.
pub type PinnedClient = (
anyhow_result::Result<quinn::Endpoint>,
Arc<Mutex<Option<[u8; 32]>>>,
);
/// Client endpoint that verifies the host by certificate fingerprint.
///
/// `pin = Some(sha256)` rejects any host whose leaf cert doesn't hash to `sha256`;
/// `None` accepts any (trust-on-first-use). Either way the observed fingerprint is
/// written to the returned slot during the handshake, so a TOFU caller can persist it.
pub fn client_pinned(pin: Option<[u8; 32]>) -> PinnedClient {
client_pinned_with_identity(pin, None)
}
/// [`client_pinned`], additionally presenting a client identity (PEM cert + PKCS#8
/// key) via TLS client auth — how a paired client identifies itself to the host.
pub fn client_pinned_with_identity(
pin: Option<[u8; 32]>,
identity: Option<(&str, &str)>,
) -> PinnedClient {
let observed = Arc::new(Mutex::new(None));
let ep = (|| {
let _ = rustls::crypto::ring::default_provider().install_default();
let builder = rustls::ClientConfig::builder()
.dangerous()
.with_custom_certificate_verifier(Arc::new(PinVerify {
pin,
observed: observed.clone(),
}));
let mut rustls_cfg = match identity {
None => builder.with_no_client_auth(),
Some((cert_pem, key_pem)) => {
use rustls::pki_types::pem::PemObject;
let cert =
rustls::pki_types::CertificateDer::from_pem_slice(cert_pem.as_bytes())
.map_err(|e| {
anyhow_result::Error::msg(format!("client cert pem: {e}"))
})?;
let key = rustls::pki_types::PrivateKeyDer::from_pem_slice(key_pem.as_bytes())
.map_err(|e| anyhow_result::Error::msg(format!("client key pem: {e}")))?;
builder
.with_client_auth_cert(vec![cert], key)
.map_err(|e| anyhow_result::Error::msg(format!("client auth: {e}")))?
}
};
// Must match the server's ALPN ([`QUIC_ALPN`]) or the handshake is rejected.
rustls_cfg.alpn_protocols = vec![QUIC_ALPN.to_vec()];
let quic_cfg = quinn::crypto::rustls::QuicClientConfig::try_from(rustls_cfg)
.map_err(|e| anyhow_result::Error::msg(format!("quic client config: {e}")))?;
let mut client_cfg = quinn::ClientConfig::new(Arc::new(quic_cfg));
client_cfg.transport_config(stream_transport()); // keep-alive — see stream_transport
let mut ep = quinn::Endpoint::client("0.0.0.0:0".parse().unwrap())?;
ep.set_default_client_config(client_cfg);
Ok(ep)
})();
(ep, observed)
}
/// Minimal error plumbing without pulling anyhow into punktfunk-core's public API.
pub mod anyhow_result {
pub type Result<T> = std::result::Result<T, Error>;
#[derive(Debug)]
pub struct Error(String);
impl Error {
pub fn msg(s: String) -> Self {
Error(s)
}
}
impl std::fmt::Display for Error {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
f.write_str(&self.0)
}
}
impl std::error::Error for Error {}
impl From<std::io::Error> for Error {
fn from(e: std::io::Error) -> Self {
Error(e.to_string())
}
}
}
/// Fingerprint-pinning verifier: trust is the SHA-256 of the host's (self-signed) leaf
/// cert, not a CA chain. With no pin it accepts any cert (TOFU) but still records what
/// it saw, so the embedder can persist the fingerprint and pin it from then on.
/// Server-side client-cert verifier: accept any (self-signed) client certificate but
/// verify the handshake signature for real — possession of the presented cert's key is
/// what makes the post-handshake fingerprint ([`peer_fingerprint`]) meaningful.
/// Authorization (is this fingerprint paired?) happens at the application layer.
#[derive(Debug)]
struct AcceptAnyClientCert;
impl rustls::server::danger::ClientCertVerifier for AcceptAnyClientCert {
fn root_hint_subjects(&self) -> &[rustls::DistinguishedName] {
&[]
}
fn client_auth_mandatory(&self) -> bool {
false // unpaired/legacy clients still connect; gating is per-feature
}
fn verify_client_cert(
&self,
_end_entity: &rustls::pki_types::CertificateDer<'_>,
_intermediates: &[rustls::pki_types::CertificateDer<'_>],
_now: rustls::pki_types::UnixTime,
) -> std::result::Result<rustls::server::danger::ClientCertVerified, rustls::Error>
{
Ok(rustls::server::danger::ClientCertVerified::assertion())
}
fn verify_tls12_signature(
&self,
message: &[u8],
cert: &rustls::pki_types::CertificateDer<'_>,
dss: &rustls::DigitallySignedStruct,
) -> std::result::Result<rustls::client::danger::HandshakeSignatureValid, rustls::Error>
{
rustls::crypto::verify_tls12_signature(
message,
cert,
dss,
&rustls::crypto::ring::default_provider().signature_verification_algorithms,
)
}
fn verify_tls13_signature(
&self,
message: &[u8],
cert: &rustls::pki_types::CertificateDer<'_>,
dss: &rustls::DigitallySignedStruct,
) -> std::result::Result<rustls::client::danger::HandshakeSignatureValid, rustls::Error>
{
rustls::crypto::verify_tls13_signature(
message,
cert,
dss,
&rustls::crypto::ring::default_provider().signature_verification_algorithms,
)
}
fn supported_verify_schemes(&self) -> Vec<rustls::SignatureScheme> {
rustls::crypto::ring::default_provider()
.signature_verification_algorithms
.supported_schemes()
}
}
#[derive(Debug)]
struct PinVerify {
pin: Option<[u8; 32]>,
observed: Arc<Mutex<Option<[u8; 32]>>>,
}
impl rustls::client::danger::ServerCertVerifier for PinVerify {
fn verify_server_cert(
&self,
end_entity: &rustls::pki_types::CertificateDer<'_>,
_intermediates: &[rustls::pki_types::CertificateDer<'_>],
_server_name: &rustls::pki_types::ServerName<'_>,
_ocsp: &[u8],
_now: rustls::pki_types::UnixTime,
) -> std::result::Result<rustls::client::danger::ServerCertVerified, rustls::Error>
{
let fp = cert_fingerprint(end_entity.as_ref());
*self.observed.lock().unwrap() = Some(fp);
if let Some(expected) = self.pin {
if fp != expected {
return Err(rustls::Error::InvalidCertificate(
rustls::CertificateError::ApplicationVerificationFailure,
));
}
}
Ok(rustls::client::danger::ServerCertVerified::assertion())
}
// The handshake signatures MUST be verified for real even though we pin the cert:
// CertificateVerify is what proves the peer *holds the pinned cert's private key* —
// skip it and an active MITM can replay the host's (public) certificate, match the
// pin, and complete the handshake with its own key.
fn verify_tls12_signature(
&self,
message: &[u8],
cert: &rustls::pki_types::CertificateDer<'_>,
dss: &rustls::DigitallySignedStruct,
) -> std::result::Result<rustls::client::danger::HandshakeSignatureValid, rustls::Error>
{
rustls::crypto::verify_tls12_signature(
message,
cert,
dss,
&rustls::crypto::ring::default_provider().signature_verification_algorithms,
)
}
fn verify_tls13_signature(
&self,
message: &[u8],
cert: &rustls::pki_types::CertificateDer<'_>,
dss: &rustls::DigitallySignedStruct,
) -> std::result::Result<rustls::client::danger::HandshakeSignatureValid, rustls::Error>
{
rustls::crypto::verify_tls13_signature(
message,
cert,
dss,
&rustls::crypto::ring::default_provider().signature_verification_algorithms,
)
}
fn supported_verify_schemes(&self) -> Vec<rustls::SignatureScheme> {
rustls::crypto::ring::default_provider()
.signature_verification_algorithms
.supported_schemes()
}
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn welcome_roundtrip() {
let w = Welcome {
abi_version: 1,
udp_port: 9999,
mode: Mode {
width: 2560,
height: 1440,
refresh_hz: 240,
},
fec: FecConfig {
scheme: FecScheme::Gf16,
fec_percent: 20,
max_data_per_block: 4096,
},
shard_payload: 1200,
encrypt: true,
key: [7u8; 16],
salt: [1, 2, 3, 4],
frames: 600,
compositor: CompositorPref::Gamescope,
gamepad: GamepadPref::DualSense,
bitrate_kbps: 50_000,
bit_depth: 10,
color: ColorInfo::HDR10_BT2020_PQ,
};
assert_eq!(Welcome::decode(&w.encode()).unwrap(), w);
}
#[test]
fn hdr_meta_datagram_roundtrip_and_truncation() {
let m = HdrMeta {
// BT.2020 display primaries in 1/50000 units (the DXGI/ST.2086 reference values).
display_primaries: [[8500, 39850], [6550, 2300], [35400, 14600]],
white_point: [15635, 16450], // D65
max_display_mastering_luminance: 10_000_000, // 1000 nits in 0.0001 cd/m²
min_display_mastering_luminance: 1, // 0.0001 nits
max_cll: 1000,
max_fall: 400,
};
let d = encode_hdr_meta_datagram(&m);
assert_eq!(d[0], HDR_META_MAGIC);
assert_eq!(decode_hdr_meta_datagram(&d), Some(m));
// Truncated buffers and a wrong tag are rejected (never partially read).
for n in 0..d.len() {
assert_eq!(decode_hdr_meta_datagram(&d[..n]), None);
}
let mut bad = d.clone();
bad[0] = HIDOUT_MAGIC;
assert_eq!(decode_hdr_meta_datagram(&bad), None);
}
#[test]
fn hello_start_roundtrip() {
let h = Hello {
abi_version: 1,
mode: Mode {
width: 1280,
height: 720,
refresh_hz: 120,
},
compositor: CompositorPref::Kwin,
gamepad: GamepadPref::DualSense,
bitrate_kbps: 25_000,
name: Some("Test Device".into()),
launch: Some("steam:570".into()),
video_caps: VIDEO_CAP_10BIT,
};
assert_eq!(Hello::decode(&h.encode()).unwrap(), h);
let s = Start {
client_udp_port: 1234,
};
assert_eq!(Start::decode(&s.encode()).unwrap(), s);
}
#[test]
fn compositor_pref_wire_and_names() {
for p in [
CompositorPref::Auto,
CompositorPref::Kwin,
CompositorPref::Wlroots,
CompositorPref::Mutter,
CompositorPref::Gamescope,
] {
assert_eq!(CompositorPref::from_u8(p.to_u8()), p);
assert_eq!(CompositorPref::from_name(p.as_str()), Some(p));
}
// Aliases + unknowns.
assert_eq!(CompositorPref::from_name("KDE"), Some(CompositorPref::Kwin));
assert_eq!(
CompositorPref::from_name("sway"),
Some(CompositorPref::Wlroots)
);
assert_eq!(CompositorPref::from_name("nope"), None);
// Unknown wire byte degrades to Auto (forward-compatible).
assert_eq!(CompositorPref::from_u8(200), CompositorPref::Auto);
}
#[test]
fn gamepad_pref_wire_and_names() {
for p in [
GamepadPref::Auto,
GamepadPref::Xbox360,
GamepadPref::DualSense,
GamepadPref::XboxOne,
GamepadPref::DualShock4,
] {
assert_eq!(GamepadPref::from_u8(p.to_u8()), p);
assert_eq!(GamepadPref::from_name(p.as_str()), Some(p));
}
// Distinct wire bytes (forward-compat with peers that only know 0..=2).
assert_eq!(GamepadPref::XboxOne.to_u8(), 3);
assert_eq!(GamepadPref::DualShock4.to_u8(), 4);
// Aliases + unknowns.
assert_eq!(GamepadPref::from_name("PS5"), Some(GamepadPref::DualSense));
assert_eq!(GamepadPref::from_name("x360"), Some(GamepadPref::Xbox360));
assert_eq!(GamepadPref::from_name("ps4"), Some(GamepadPref::DualShock4));
assert_eq!(GamepadPref::from_name("DS4"), Some(GamepadPref::DualShock4));
assert_eq!(
GamepadPref::from_name("xbox-one"),
Some(GamepadPref::XboxOne)
);
assert_eq!(GamepadPref::from_name("series"), Some(GamepadPref::XboxOne));
assert_eq!(GamepadPref::from_name("nope"), None);
// Unknown wire byte degrades to Auto (forward-compatible).
assert_eq!(GamepadPref::from_u8(200), GamepadPref::Auto);
}
#[test]
fn hello_welcome_compositor_back_compat() {
// Trailing optional bytes (compositor at 20/53, gamepad at 21/54): a legacy peer's
// shorter message still decodes (missing fields = Auto), and a legacy peer reading a
// new message ignores the trailing bytes. Simulate both directions by truncation.
let h = Hello {
abi_version: 2,
mode: Mode {
width: 1920,
height: 1080,
refresh_hz: 60,
},
compositor: CompositorPref::Mutter,
gamepad: GamepadPref::DualSense,
bitrate_kbps: 80_000,
name: None,
launch: None,
video_caps: 0,
};
let enc = h.encode();
assert_eq!(enc.len(), 26);
// Legacy (20-byte) Hello → both Auto, no bitrate, mode intact.
let legacy = Hello::decode(&enc[..20]).unwrap();
assert_eq!(legacy.compositor, CompositorPref::Auto);
assert_eq!(legacy.gamepad, GamepadPref::Auto);
assert_eq!(legacy.bitrate_kbps, 0);
assert_eq!(legacy.mode, h.mode);
// Compositor-era (21-byte) Hello → compositor intact, gamepad Auto.
let mid = Hello::decode(&enc[..21]).unwrap();
assert_eq!(mid.compositor, CompositorPref::Mutter);
assert_eq!(mid.gamepad, GamepadPref::Auto);
// Gamepad-era (22-byte) Hello → compositor + gamepad intact, bitrate 0 (host default).
let pre_bitrate = Hello::decode(&enc[..22]).unwrap();
assert_eq!(pre_bitrate.gamepad, GamepadPref::DualSense);
assert_eq!(pre_bitrate.bitrate_kbps, 0);
// Full message → bitrate intact.
assert_eq!(Hello::decode(&enc).unwrap().bitrate_kbps, 80_000);
let w = Welcome {
abi_version: 2,
udp_port: 7000,
mode: h.mode,
fec: FecConfig {
scheme: FecScheme::Gf16,
fec_percent: 20,
max_data_per_block: 4096,
},
shard_payload: 1200,
encrypt: true,
key: [3u8; 16],
salt: [9, 8, 7, 6],
frames: 0,
compositor: CompositorPref::Kwin,
gamepad: GamepadPref::Xbox360,
bitrate_kbps: 120_000,
bit_depth: 10,
color: ColorInfo::HDR10_BT2020_PQ,
};
let wenc = w.encode();
assert_eq!(wenc.len(), 64); // 60 base + 4 colour bytes
let legacy_w = Welcome::decode(&wenc[..53]).unwrap();
assert_eq!(legacy_w.compositor, CompositorPref::Auto);
assert_eq!(legacy_w.gamepad, GamepadPref::Auto);
assert_eq!(legacy_w.bitrate_kbps, 0);
assert_eq!(legacy_w.frames, 0);
assert_eq!(legacy_w.key, w.key);
let mid_w = Welcome::decode(&wenc[..54]).unwrap();
assert_eq!(mid_w.compositor, CompositorPref::Kwin);
assert_eq!(mid_w.gamepad, GamepadPref::Auto);
// Gamepad-era (55-byte) Welcome → gamepad intact, bitrate 0 (unknown).
let pre_bitrate_w = Welcome::decode(&wenc[..55]).unwrap();
assert_eq!(pre_bitrate_w.gamepad, GamepadPref::Xbox360);
assert_eq!(pre_bitrate_w.bitrate_kbps, 0);
assert_eq!(pre_bitrate_w.bit_depth, 8); // older host (no trailing byte) → 8-bit assumed
assert_eq!(legacy_w.bit_depth, 8);
// A pre-colour (60-byte) Welcome → SDR BT.709 (the only colour those hosts produced).
let pre_color_w = Welcome::decode(&wenc[..60]).unwrap();
assert_eq!(pre_color_w.bit_depth, 10);
assert_eq!(pre_color_w.color, ColorInfo::SDR_BT709);
assert_eq!(legacy_w.color, ColorInfo::SDR_BT709);
assert_eq!(Welcome::decode(&wenc).unwrap().bitrate_kbps, 120_000);
assert_eq!(Welcome::decode(&wenc).unwrap().bit_depth, 10); // full form carries it
assert_eq!(
Welcome::decode(&wenc).unwrap().color,
ColorInfo::HDR10_BT2020_PQ
);
}
#[test]
fn hello_name_roundtrip_and_back_compat() {
let base = Hello {
abi_version: 2,
mode: Mode {
width: 1280,
height: 720,
refresh_hz: 60,
},
compositor: CompositorPref::Auto,
gamepad: GamepadPref::Auto,
bitrate_kbps: 0,
name: Some("Enrico's MacBook".into()),
launch: None,
video_caps: 0,
};
let enc = base.encode();
assert_eq!(
Hello::decode(&enc).unwrap().name.as_deref(),
Some("Enrico's MacBook")
);
// A bitrate-era (26-byte) peer reading a named Hello ignores the trailing name; a named
// host reading a bitrate-era Hello decodes name = None.
assert_eq!(Hello::decode(&enc[..26]).unwrap().name, None);
// No name → wire form is byte-identical to the bitrate-era message (26 bytes).
let unnamed = Hello {
name: None,
..base.clone()
};
assert_eq!(unnamed.encode().len(), 26);
// Over-long names truncate to a char boundary within HELLO_NAME_MAX on encode.
let long = Hello {
name: Some(format!("{}ü", "x".repeat(HELLO_NAME_MAX - 1))), // ü straddles the cap
..base.clone()
};
let dec = Hello::decode(&long.encode()).unwrap();
let n = dec.name.expect("truncated name still present");
assert!(n.len() <= HELLO_NAME_MAX && n.starts_with('x'));
// A corrupt length byte (longer than the buffer) or bad UTF-8 degrades to None, never Err.
let mut bad_len = unnamed.encode();
bad_len.push(40); // claims 40 name bytes, none follow
assert_eq!(Hello::decode(&bad_len).unwrap().name, None);
let mut bad_utf8 = unnamed.encode();
bad_utf8.extend_from_slice(&[2, 0xFF, 0xFE]);
assert_eq!(Hello::decode(&bad_utf8).unwrap().name, None);
}
#[test]
fn hello_launch_roundtrip_and_back_compat() {
let base = Hello {
abi_version: 2,
mode: Mode {
width: 1920,
height: 1080,
refresh_hz: 60,
},
compositor: CompositorPref::Auto,
gamepad: GamepadPref::Auto,
bitrate_kbps: 0,
name: None,
launch: None,
video_caps: 0,
};
// launch alone (no name): a zero-length name placeholder keeps the offset deterministic.
let with_launch = Hello {
launch: Some("steam:570".into()),
..base.clone()
};
assert_eq!(Hello::decode(&with_launch.encode()).unwrap(), with_launch);
// launch + name together.
let both = Hello {
name: Some("Enrico's Mac".into()),
launch: Some("custom:abc123".into()),
..base.clone()
};
assert_eq!(Hello::decode(&both.encode()).unwrap(), both);
// name but no launch (a name-era client): launch decodes None.
let name_only = Hello {
name: Some("Enrico's Mac".into()),
..base.clone()
};
assert_eq!(Hello::decode(&name_only.encode()).unwrap().launch, None);
// Neither field → still the 26-byte bitrate-era form (no launch placeholder emitted).
assert_eq!(base.encode().len(), 26);
assert_eq!(Hello::decode(&base.encode()).unwrap().launch, None);
// A bitrate-era (26-byte) peer reading a launch-bearing Hello ignores it.
assert_eq!(
Hello::decode(&with_launch.encode()[..26]).unwrap().launch,
None
);
// Over-long ids truncate on a char boundary within HELLO_LAUNCH_MAX.
let long = Hello {
launch: Some(format!("{}ü", "x".repeat(HELLO_LAUNCH_MAX - 1))),
..base.clone()
};
let dec = Hello::decode(&long.encode())
.unwrap()
.launch
.expect("present");
assert!(dec.len() <= HELLO_LAUNCH_MAX && dec.starts_with('x'));
}
#[test]
fn reconfigure_roundtrip() {
let rq = Reconfigure {
mode: Mode {
width: 1920,
height: 1080,
refresh_hz: 144,
},
};
assert_eq!(Reconfigure::decode(&rq.encode()).unwrap(), rq);
for accepted in [true, false] {
let rs = Reconfigured {
accepted,
mode: rq.mode,
};
assert_eq!(Reconfigured::decode(&rs.encode()).unwrap(), rs);
}
// The type byte separates the post-handshake messages from each other.
assert!(Reconfigure::decode(
&Reconfigured {
accepted: true,
mode: rq.mode
}
.encode()
)
.is_err());
}
#[test]
fn request_keyframe_roundtrip() {
let bytes = RequestKeyframe.encode();
assert!(RequestKeyframe::decode(&bytes).is_ok());
// Distinct from the other control messages — its type byte must not collide.
let mode = Mode {
width: 1280,
height: 720,
refresh_hz: 60,
};
assert!(RequestKeyframe::decode(&Reconfigure { mode }.encode()).is_err());
assert!(Reconfigure::decode(&bytes).is_err());
// Length is exact (no trailing bytes accepted).
assert!(RequestKeyframe::decode(&[bytes.as_slice(), &[0]].concat()).is_err());
}
#[test]
fn loss_report_roundtrip() {
for loss_ppm in [0u32, 1, 12_345, 50_000, 1_000_000] {
let r = LossReport { loss_ppm };
assert_eq!(LossReport::decode(&r.encode()).unwrap(), r);
}
// Disjoint from the other control messages (type byte + length).
assert!(LossReport::decode(&RequestKeyframe.encode()).is_err());
assert!(RequestKeyframe::decode(&LossReport { loss_ppm: 0 }.encode()).is_err());
assert!(LossReport::decode(
&[LossReport { loss_ppm: 0 }.encode().as_slice(), &[0]].concat()
)
.is_err());
}
#[test]
fn window_loss_ppm_estimates_and_caps() {
// No traffic → 0. A clean window (nothing recovered) → 0.
assert_eq!(window_loss_ppm(0, 0, 0), 0);
assert_eq!(window_loss_ppm(0, 1000, 0), 0);
// 50 recovered of 1000 total (950 received + 50 recovered) = 5%.
assert_eq!(window_loss_ppm(50, 950, 0), 50_000);
// An unrecoverable frame adds the +5% bump (push FEC past the current cap).
assert_eq!(window_loss_ppm(50, 950, 1), 100_000);
// A total-loss window with a drop but nothing received still reports the bump, capped at 1e6.
assert_eq!(window_loss_ppm(0, 0, 3), 50_000);
assert!(window_loss_ppm(u64::MAX, 1, 9) <= 1_000_000);
}
#[test]
fn probe_messages_roundtrip() {
let req = ProbeRequest {
target_kbps: 250_000,
duration_ms: 2000,
};
assert_eq!(ProbeRequest::decode(&req.encode()).unwrap(), req);
let res = ProbeResult {
bytes_sent: 62_500_000,
packets_sent: 480,
duration_ms: 2003,
wire_packets_sent: 41_000,
send_dropped: 1_200,
};
assert_eq!(ProbeResult::decode(&res.encode()).unwrap(), res);
assert_eq!(res.encode().len(), 29);
// A pre-wire-stats host's 21-byte ProbeResult still decodes, with the new fields zeroed.
let legacy = {
let full = res.encode();
full[..21].to_vec()
};
let decoded = ProbeResult::decode(&legacy).unwrap();
assert_eq!(decoded.wire_packets_sent, 0);
assert_eq!(decoded.send_dropped, 0);
assert_eq!(decoded.bytes_sent, res.bytes_sent);
// Type bytes keep the control messages disjoint from each other.
assert!(ProbeRequest::decode(&res.encode()).is_err());
assert!(Reconfigure::decode(&req.encode()).is_err());
assert!(ProbeResult::decode(&req.encode()).is_err());
}
#[test]
fn clock_messages_roundtrip() {
let probe = ClockProbe {
t1_ns: 1_700_000_000_123,
};
assert_eq!(ClockProbe::decode(&probe.encode()).unwrap(), probe);
let echo = ClockEcho {
t1_ns: 1_700_000_000_123,
t2_ns: 1_700_000_050_456,
t3_ns: 1_700_000_050_789,
};
assert_eq!(ClockEcho::decode(&echo.encode()).unwrap(), echo);
// Disjoint from the other control messages (distinct type bytes).
assert!(ClockProbe::decode(&echo.encode()).is_err());
assert!(ProbeRequest::decode(&probe.encode()).is_err());
assert!(ClockEcho::decode(&probe.encode()).is_err());
}
#[test]
fn clock_offset_picks_min_rtt_and_recovers_offset() {
// Host clock is +1_000_000 ns ahead of the client. Construct samples where a symmetric
// round-trip recovers exactly that offset, and a noisy (asymmetric, high-RTT) sample is
// present but must be ignored by the min-RTT selection.
const OFF: i64 = 1_000_000;
// Clean sample: client t1=0, one-way=200µs each way → t2 = t1 + 200_000 + OFF (host clock),
// t3 = t2 + 50_000 (host processing), t4 = t3 - OFF + 200_000 (back in client clock).
let t1 = 0u64;
let t2 = (t1 as i64 + 200_000 + OFF) as u64;
let t3 = t2 + 50_000;
let t4 = (t3 as i64 - OFF + 200_000) as u64;
// Noisy sample: same offset but a fat, asymmetric RTT (slow return path) — higher RTT.
let n1 = 1_000_000u64;
let n2 = (n1 as i64 + 200_000 + OFF) as u64;
let n3 = n2 + 50_000;
let n4 = (n3 as i64 - OFF + 5_000_000) as u64; // 5 ms return → big RTT
let (offset, rtt) =
clock_offset_ns(&[(n1, n2, n3, n4), (t1, t2, t3, t4)]).expect("non-empty");
// The min-RTT sample recovers the offset exactly; its RTT is 2x200us, and the noisy
// (asymmetric, 5 ms return) sample is ignored by the min-RTT selection.
assert_eq!(offset, OFF);
assert_eq!(rtt, 400_000);
assert!(clock_offset_ns(&[]).is_none());
}
#[test]
fn control_messages_disjoint_from_hello() {
// A Hello uses MAGIC (PKF1); control messages use CTL_MAGIC (PKFc). No Hello — at
// any abi_version — can be misparsed as a control message, and vice-versa.
for abi in [1u32, 2, 16, 0x10, 0x0113, 0x1410] {
let h = Hello {
abi_version: abi,
mode: Mode {
width: 1280,
height: 720,
refresh_hz: 60,
},
compositor: CompositorPref::Auto,
gamepad: GamepadPref::Auto,
bitrate_kbps: 0,
name: None,
launch: None,
video_caps: 0,
}
.encode();
assert!(PairRequest::decode(&h).is_err(), "abi {abi} parsed as pair");
assert!(Reconfigure::decode(&h).is_err());
}
// And a PairRequest never parses as a Hello.
let pr = PairRequest {
name: "x".into(),
spake_a: vec![0u8; 33],
}
.encode();
assert!(Hello::decode(&pr).is_err());
}
#[test]
fn pair_messages_roundtrip() {
let pr = PairRequest {
name: "Enrico's Mac".into(),
spake_a: vec![1, 2, 3, 4, 5],
};
assert_eq!(PairRequest::decode(&pr.encode()).unwrap(), pr);
let pc = PairChallenge {
spake_b: vec![9; 33],
confirm: [7u8; 32],
};
assert_eq!(PairChallenge::decode(&pc.encode()).unwrap(), pc);
let pp = PairProof { confirm: [3u8; 32] };
assert_eq!(PairProof::decode(&pp.encode()).unwrap(), pp);
for ok in [true, false] {
assert_eq!(
PairResult::decode(&PairResult { ok }.encode()).unwrap().ok,
ok
);
}
// Length-exact: a truncated/padded PairProof is rejected.
let mut bad = pp.encode();
bad.push(0);
assert!(PairProof::decode(&bad).is_err());
}
#[test]
fn spake2_pairing_agrees_only_on_matching_pin_and_certs() {
let cfp = [0x11u8; 32];
let hfp = [0x22u8; 32];
// Right PIN, same fingerprint views on both sides → both confirmations agree.
let (ca, ma) = pake::start(true, "4321", &cfp, &hfp);
let (cb, mb) = pake::start(false, "4321", &cfp, &hfp);
let a = ca.finish(&mb).unwrap();
let b = cb.finish(&ma).unwrap();
assert!(pake::verify(&a.host, &b.host) && pake::verify(&a.client, &b.client));
// Wrong PIN → different keys → confirmations DON'T match (one online guess wasted).
let (ca, ma) = pake::start(true, "0000", &cfp, &hfp);
let (cb, mb) = pake::start(false, "4321", &cfp, &hfp);
let a = ca.finish(&mb).unwrap();
let b = cb.finish(&ma).unwrap();
assert!(!pake::verify(&a.client, &b.client));
// MITM: the two legs saw different host certs → no agreement even with the right PIN.
let attacker_hfp = [0x33u8; 32];
let (ca, ma) = pake::start(true, "4321", &cfp, &attacker_hfp);
let (cb, mb) = pake::start(false, "4321", &cfp, &hfp);
let a = ca.finish(&mb).unwrap();
let b = cb.finish(&ma).unwrap();
assert!(!pake::verify(&a.client, &b.client));
}
#[test]
fn audio_datagram_roundtrip() {
let opus = [0x42u8; 97];
let d = encode_audio_datagram(7, 1_000_000_123, &opus);
assert_eq!(d[0], AUDIO_MAGIC);
let (seq, pts, payload) = decode_audio_datagram(&d).unwrap();
assert_eq!((seq, pts), (7, 1_000_000_123));
assert_eq!(payload, opus);
assert!(decode_audio_datagram(&d[..12]).is_none()); // truncated header
assert!(decode_audio_datagram(&[0u8; 13]).is_none()); // bad magic
// Empty payload is legal (DTX) — header-only datagram.
let header_only = encode_audio_datagram(0, 0, &[]);
let (_, _, empty) = decode_audio_datagram(&header_only).unwrap();
assert!(empty.is_empty());
}
#[test]
fn rumble_datagram_roundtrip() {
let d = encode_rumble_datagram(1, 0x1234, 0xFFFF);
assert_eq!(d[0], RUMBLE_MAGIC);
assert_eq!(decode_rumble_datagram(&d), Some((1, 0x1234, 0xFFFF)));
assert!(decode_rumble_datagram(&d[..6]).is_none());
}
#[test]
fn mic_datagram_roundtrip_and_disjoint_from_audio() {
let opus = [0x5Au8; 80];
let d = encode_mic_datagram(42, 9_999, &opus);
assert_eq!(d[0], MIC_MAGIC);
let (seq, pts, payload) = decode_mic_datagram(&d).unwrap();
assert_eq!((seq, pts), (42, 9_999));
assert_eq!(payload, opus);
assert!(decode_mic_datagram(&d[..12]).is_none()); // truncated
// Tag separation: a mic datagram is not an audio datagram and vice-versa.
assert!(decode_audio_datagram(&d).is_none());
assert!(decode_mic_datagram(&encode_audio_datagram(1, 2, &opus)).is_none());
// Empty payload (DTX) is legal.
assert!(decode_mic_datagram(&encode_mic_datagram(0, 0, &[]))
.unwrap()
.2
.is_empty());
}
#[test]
fn rich_input_roundtrip() {
for ev in [
RichInput::Touchpad {
pad: 1,
finger: 0,
active: true,
x: 40000,
y: 12345,
},
RichInput::Motion {
pad: 0,
gyro: [-100, 200, -300],
accel: [16384, -8192, 1],
},
] {
let d = ev.encode();
assert_eq!(d[0], RICH_INPUT_MAGIC);
assert_eq!(RichInput::decode(&d), Some(ev));
}
// Disjoint from the fixed input datagram (0xC8); unknown kind + truncation → None.
assert!(RichInput::decode(&[crate::input::INPUT_MAGIC; 18]).is_none());
assert!(RichInput::decode(&[RICH_INPUT_MAGIC, 0x7F]).is_none()); // unknown kind
assert!(RichInput::decode(&[RICH_INPUT_MAGIC, RICH_TOUCHPAD, 0]).is_none());
// short
}
#[test]
fn hid_output_roundtrip() {
let cases = [
HidOutput::Led {
pad: 2,
r: 0xAA,
g: 0xBB,
b: 0xCC,
},
HidOutput::PlayerLeds {
pad: 0,
bits: 0b10101,
},
HidOutput::Trigger {
pad: 1,
which: 1,
effect: vec![0x26, 0x90, 0xA0, 0xFF, 0x00, 0x00],
},
];
for ev in &cases {
let d = ev.encode();
assert_eq!(d[0], HIDOUT_MAGIC);
assert_eq!(HidOutput::decode(&d).as_ref(), Some(ev));
}
assert!(HidOutput::decode(&[HIDOUT_MAGIC, 0x7F]).is_none()); // unknown kind
// A rich-input datagram is not a HID-output datagram.
assert!(HidOutput::decode(
&RichInput::Motion {
pad: 0,
gyro: [0; 3],
accel: [0; 3]
}
.encode()
)
.is_none());
}
#[test]
fn fingerprint_is_sha256_of_der() {
// Stable across calls, distinct for distinct certs.
let a = endpoint::cert_fingerprint(b"cert-a");
assert_eq!(a, endpoint::cert_fingerprint(b"cert-a"));
assert_ne!(a, endpoint::cert_fingerprint(b"cert-b"));
}
}