The tunnel branch's other half is served for real against published
alktunnels 0.4.1 / alkcall 0.10.1, with POC-3 §C.4 as the template:
- tcpip_forward/streamlocal_forward (+ both cancel forms) map the
vanilla listen request family-ward through TunnelListener::open on
the held ChannelClient (bounded inline dial — the global request's
reply + the &mut u32 bound-port out-param are the hook's); the
wire bind endpoint rides as the resource string verbatim (OpenSSH
client-side normalization parity). A reply without the minted
listen token/bound report declines and reaps its fabric listener.
- the door serves the fabric's inbound tunnel/forwarded opens: the
serve config gains TunnelListenSeam (the seam-config second
course-correction — the shared ServingConfig registry the assembly
wired at from_connection_with_serving); alkssh registers the
forwarded openable (ChannelCore over a clone of the held client's
manager) at SshAdapter::new — a failed registration is a failed
construction (AdapterError::ListenRegistration).
- the forwarded-tcpip data leg: token correlation through the shared
ListenRouter → the in-crate per-session channel cap at the accept
surface (the acceptor vocabulary) → Handle::
channel_open_forwarded_tcpip streaming the listen request's own
args + the actually-bound port (sshd parity) with
TunnelForwardedParams.peer as the originator → pump_bidi(ssh,
fabric). Correlation-miss → teardown-at-birth, never a half-open
SSH channel. Unix arrivals ride forwarded-streamlocal@openssh.com.
- bounded bookkeeping: the per-session listener map packet-loop-only
with a dedicated max_concurrent_channels-ceiling counter; the
route map bounded by construction (mints at accepted listens,
removed at cancels + session teardown — the handler's Drop).
- the harness grew the client-side accept hook
(server_channel_open_forwarded_tcpip/_streamlocal,
acceptor-driven) + a hand-rolled tracing subscriber; 18 contract
rows + both real-tool smokes (ssh -L, ssh -R + curl) green in
tests/tunnel_mapping.rs; the wave-2 stub listen rows migrated per
build (unfeatured / seam-unconfigured).
Verified: cargo test across default/git/session/sftp/tunnel and all
combos + --all-features; clippy -D warnings (default, all-features,
combos); cargo fmt --check; cargo doc --no-deps clean;
taskgraph validate (26 tasks).
- The route-1 bridge (ADR-006 decision 1, the POC-3 stage-C recipe
re-landed as contract): per accepted `direct-tcpip` /
`direct-streamlocal` open, the target/substrate are constructed from
the SSH open arguments and the spawned task runs
`TunnelSession::open_direct` over the held `Arc<ChannelClient>` →
accept only after the fabric open succeeds → `take_halves()` pumped
against the taken channel (`pump_bidi`) — the open hook returns fast;
a fabric failure answers the explicit `ConnectFailed` reject (the
wave-2 stub's reason surviving as the real decline; the stub retired
from the direct rows, kept on `forwarded-tcpip` for w3-tunnel-listen).
- The cap across the fabric window (recorded): the admission is taken
at the hook and held across the fabric open; a fabric failure
releases the count inside the spawned task — the admitted-but-
rejected shape no `channel_close` can ever fire for. `ChannelCap`
became a mutex-backed `Arc`: admissions stay packet-loop-only,
releases have exactly two disjoint sites (close hook, bridge task),
both saturating.
- The identity ride recorded (the `w2-auth-bridge` parked item): the
alkhub `hub_leg.rs` one-time-set precedent is a serving-side set; the
client-side `take_call_connection()` seam is rejected for this door
(one-shot detach of the shared assembly handle's open surface — a
fortiori the relay note's "wrong for hubs"); the identity the fabric's
`AccessControl::check` consults is the dial identity (CF-005), the
composition is assembly policy, and the door structurally refuses
anonymous serving (`no-identity`, unreachable on the wire). Upstream
ask booked for the gate.
- The OQ-11 runtime-Unix gate: `direct-streamlocal` compiles wherever
`tunnel` compiles; off-Unix a clean open-decline before any fabric
call (dial-call witness at zero), on-Unix the real bridge.
- Decline classes recorded: policy → `AdministrativelyProhibited`
(unfeatured/cap/`no-identity`); cannot-bridge → `ConnectFailed`
(failed fabric open, absent handle under the feature, invalid
target, off-Unix streamlocal); the event vocabulary gains
`invalid-target` and `unix-unavailable`.
- The optional dep lands: `alktunnels 0.4.1` (pin re-verified against
crates.io — max stable, MIT OR Apache-2.0, rust_version 1.88, alkcall
0.10.1 exact), wired `tunnel = ["dep:alktunnels"]`, `local` never
enabled.
- The fabric double (`tests/tunnel_mapping.rs`): the POC-3 §C.4
in-process recipe — `ChannelsAdapter` + `InstallChannelZero` + the
alktunnels openables + a hand-rolled dial/dial-fail seam (in-process
duplex targets keyed by the rendered string; the smoke's dial is real
TCP). Rows: both-substrate serve round trips, fabric-failure,
cap refusal + release + recovery, the fabric-ACL composed-gate
witness, the CF-006 identity witness, the OQ-11 gate, and the
`ssh -L` + curl real-tool smoke (conditional-skip posture, ran green).
Verification: `cargo test` rows green per feature build (default,
tunnel, git, session, git+session, tunnel+git, tunnel+session,
--all-features); `cargo clippy --all-targets -- -D warnings` ×2
(default + --all-features) clean; `cargo fmt --check`; `cargo doc
--no-deps` 0 warnings; `taskgraph validate` (26 tasks).
The biggest single-row surface of the spine: pty/shell/pipe-exec serve
through the published alktty seam (drive_session_pre_negotiated) over a
translation bridge, re-landing POC-3 stage D as contract:
- src/tty_map.rs (session feature): the bridge (SSH data → Chunk::stdin
through a bounded mpsc + framing task; SSH EOF → the zero-length
stdin sentinel — verified against alktty's pump semantics; stdout →
data; stderr → extended_data(1); exit chunk → the derivation
contract), the locally-built negotiation (OQ-08: shell argv verbatim,
wrapper ++ [cmd], cwd/env session-side, ttymodes → the reserved {}
modes JSON), and the spawned serving path.
- serve_tty_row: driven chunks→SSH inline so the exit report is the
path's final act (status before close, ADR-006 decision 4); two
cancel signals (per-channel watch fired by channel_close, connection
teardown fired by SessionHandler::Drop) abort the alktty session
task — the ADR-056 kill-on-drop contract is the cancelled session's
cleanup.
- Derivation contract rules 1–6 in derive_exit + the crate-local
signum→name table: −N → exit-signal(name), −1 → exit-status(255),
core_dumped never, unmapped negatives → 255, the PTY-path rule-5
fidelity limit documented; wire rows pin the shapes.
- Negotiation-error frames (alktty's 0x00-length-prefixed error
framing) → negotiation-failed serving decline + exit-status(255) +
close — the one could-not-start claim this door makes (nothing ran).
- Control rows: window_change/signal → the per-channel BridgeSurface
(bounded mpsc, try_send, never awaited on the packet loop); signal
names verbatim (no decline shape — fire-and-forget); pre-serve
resizes update the stored pty params (final size wins).
- Unset-declines (OQ-08) keep the git row's serving-path shape
(failure then close, spawned): shell-unconfigured /
wrapper-unconfigured / seam-unconfigured; pipe-less shell SERVES
pipe-mode (the recorded vanilla-sshd posture); env_request decline
unchanged (OQ-09).
- tests: the hand-rolled TtyBackend shim + ownership witness doubles;
serving rows through the harness, the unset-field decline matrix,
derivation rows on the wire, negotiation-failure rows, the identity
ride asserted live at the seam, the kill witness; the real-tool
smoke — OpenSSH -tt against a real PTY via dev-dep alktty local
(test graph only), skip-with-reason posture. Wave-2 stub rows
migrated to the new decline reasons (dispatch_core, observe).
Verification: cargo test (113) / --features session (149) / git (142) /
tunnel (115) / --all-features (161) — all green; cargo clippy
--all-targets -- -D warnings ×5 feature configs; cargo fmt --check;
cargo doc --no-deps ×3 builds clean; taskgraph validate.
- dispatch: the full exec grammar replaces the wave-2 skeleton probe
(quoted/unquoted paths, the .git normalization decision, unknown-
service / service-only decline-with-reason class; the probe's unit
rows migrate with their pinned verdicts preserved)
- git_map: the git row dispatches serve_duplex_resolved over the
channel duplex (repo id validated, never resolved; the exit-status
mapping 0/1 decided per POC-3 §A.5; status before close from the
spawned task), with the resolved identity riding the seam
- handler: the store-and-take channel handoff (stored at the open,
taken in the spawned serving task, released at close) and the
max_exec_command_len pre-parse cap
- config course correction: GitSeam carries the assembly-supplied
alkgit Limits (the ADR-009 budget alkgit's contract assigns the
assembler)
- tests: tests/git_mapping.rs (byte-level process-mode advertisement,
ls-refs round + exit 0, the collapsed-denial byte-order + exit 1,
the identity-ride authorize-gate witness, the packless CAS push,
the grammar/cap decline rows, the sequential-serve store row, and
the real-tool git 2.43 clone smoke over a TCP mount with a
skip-with-reason posture); dispatch_core/observe rows updated to
the new decision set; tests/common/git_doubles.rs (the hand-rolled
recording alkgit quartet)
Verification: cargo test (default), --features session, --features
git, --all-features; clippy -D warnings ×2; fmt --check;
cargo doc --no-deps; taskgraph validate
The wave-2 gate's booked finding: observability on the decline paths.
`tracing` rides the manifest per the ADR-002 toolkit but nothing in
src/ emitted — a decline's "reason" was only the routing decision
documented per build.
- src/observe.rs: the event vocabulary, adopting the family posture
read from alktty/alktunnels/alkcall/alkhttp (free tracing fns,
message-last lowercase, flat fields; no info!/trace!, no macros,
no spans): feature_build + row + channel_id + decline_class
(open/request/serving/auth) + reason + exec_route (exec rows);
declines at debug, the serving-path failure arm the vocabulary's
one warn
- handler.rs: every decline site emits — auth dispositions
(non-ed25519 / fingerprint-unresolved / the four unimplemented
methods), open-level declines (unfeatured / never-feature /
cap-exceeded / tunnel connect-failed stub), request-level
capability declines (exec route-aware, subsystem, env, x11, agent,
the -R listen forms), and the seam-stub serving declines with the
spawned-path lifecycle (started / ended / failed — the shape the
wave-3 mappings inherit)
- tests/observe.rs: the event-presence pin — a hand-rolled global
capture subscriber (the recorded test convention; no event-capture
precedent exists in the family), field-matching rows across the
default/git/session/tunnel/--all-features builds, and the safety
scan (no username, no fingerprint ever in an event)
- helper-level exact shapes pinned in src/observe.rs unit rows
Verification: cargo test (default, --features git/session/tunnel,
--all-features all green), clippy x2 --all-targets -D warnings,
fmt --check, cargo doc --no-deps 0 warnings, taskgraph validate.
- ServeConfig gains cfg-gated SessionSeam / GitSeam Option fields
(whole-Option struct per seam — the shape decision recorded in the
task notes): unset → the owned rows decline even though the feature
is on, no construction-time validation
- SessionSeam carries the alktty backends map + backend selector +
ownership provider; GitSeam carries the alkgit backend quartet +
caller-owned pipeline semaphore + push_options_negotiated
- optional deps alktty 0.8.1 / alkgit 0.1.0 wired feature-to-dep
(pins verified against crates.io: licenses, MSRV, shared alkcall
resolution); gix-hash 0.28 as dev-dep only (alkgit does not
re-export ObjectId for the trait doubles)
- per-feature construction/unset-declines/Debug rows in config.rs;
accessors session_seam_configured / git_seam_configured; docs state
what each seam handle carries
Verified: cargo test (per-feature + --all-features), clippy ×2
(-D warnings), fmt, cargo doc --no-deps, cargo tree feature isolation
(git-build: no alktty; session-build: no alkgit), taskgraph validate
Six implementation tasks + the gate under tasks/implementation/,
chained sequentially (the mappings replace stubs in the same Handler
impl and share the decline-matrix test binaries):
- w3-seam-config: the serve-config's per-feature seam handles
(alktty backends/ownership/selector; the alkgit quartet/pipeline/
push-options flag) + the optional sibling deps — wave 3's first
course correction to the wave-1 config surface
- w3-decline-tracing: the wave-2 gate's booked finding — the
decline/serve-path tracing vocabulary, landed before the mappings
- w3-git-mapping: the full exec grammar replaces the wave-2 probe +
the serve_duplex_resolved dispatch + the store-and-take handoff
- w3-tty-session: the translation bridge + the exit-derivation
contract (rules 1-6, the signum table)
- w3-tunnel-direct: the route-1 bridge (accept only after the fabric
open succeeds) + set_identity propagation + the capacity-across-
fabric-window mechanics
- w3-tunnel-listen: the -R listen flow + the forwarded-tcpip data
leg (the POC-untested leg; the stop-and-book provision)
- review-wave-3: the gate
The plan carries the wave-3 decomposition record with four
interpretations flagged for the gate (the serve-config course
correction, the already-discharged server-side sftp bullet, the
w3-tunnel-listen open mechanics, the booked-items' wave-3 homes).
taskgraph validate: 26 tasks, clean.
Sibling pins verified against crates.io at decomposition time:
alktty 0.8.1 / alkgit 0.1.0 / alktunnels 0.4.1 / alkcall 0.10.1.
Gate reading (commits b90e89b..196289f) against the architecture line
by line: ADR-001 mount contract, ADR-002 Config construction,
ADR-003 feature gates, ADR-004 dispositions, ADR-006 constraints,
mapping.md skeleton decline matrix per build, bounded resources, and
the harness — all confirmed. All four flagged interpretations
confirmed as recorded.
Fixed inline before committing (task-file hygiene only):
- w2-loopback-harness, w2-dispatch-decline-core: acceptance boxes
checked once verified against the landed rows/runs
- w2-bounded-resources: stale placeholder lines removed
- review-wave-2: verdict recorded
Booked finding (next wave's decomposition): decline-path
tracing/observability — the reason a given wire decline carried is
currently docs-only (tracing unused in src/).
Verification: cargo test 104 rows green; --all-features green;
clippy ×2 -D warnings green; fmt clean; cargo doc 0 warnings;
taskgraph validate 19 tasks.
- new private channel_cap module: per-session active-channel count;
admit (check+increment at accept sites) / has_room / saturating
release, single-writer (inline packet-loop hooks), unit-tested
- handler wires the cap at every channel_open_* hook: the session
accept path admits-and-counts at the accept point; the tunnel rows
cap-gate before the seam stub (a counted-but-unopened stub would
leak the cap); x11 never consumes a count; the count releases
through the new channel_close hook
- dispatch::cap_exceeded_open_decline -> AdministrativelyProhibited
(the assembly's policy ceiling; OpenSSH MaxSessions parity)
- bounded-resources contract rows: cap reached -> clean decline,
close -> recovery open succeeds (wire-order deterministic),
zero cap refuses without poisoning, exhausted cap answers the
tunnel row with the cap reason; max_auth_attempts verified
behaviorally (within-ceiling failures keep the advertisement, the
past-ceiling attempt is the NoMoreAuthMethodsAvailable teardown);
window/packet/buffer/inactivity knobs recorded as covered by the
config-mapping tests
- max_exec_command_len stays carried, not enforced (wave-3 grammar)
Verification: cargo test (default), --features session / git /
tunnel / --all-features, clippy --all-targets (-D warnings, also
--all-features), fmt --check, cargo doc --no-deps - all green
- src/serve.rs (new): the ADR-006 decision-4 mechanics in code —
spawn_serving_path (the one choke point; nothing awaited inline)
and report_exit_status_then_close (exit-status before close via
the cloned Session::handle()), #[doc(hidden)] contract-test
re-exports; a unit row pins spawn-returns-while-pending.
- src/handler.rs: the four session-row seam stubs became spawned
serving paths (failure-then-close unchanged; stubs are plain fns —
an async stub holding &Session across the spawn is non-Send); open-
level declines and the tunnel seam stub stay inline by class, per
the new module-doc section.
- tests/spawn_return.rs (new): two end-to-end wire rows — the client
observes exit-status(7) strictly before close and after the handler
returned; the handler-returns-fast row routes follow-up traffic
while the serving path is still gated (POC-3 deadlock inversion).
- tasks/implementation/w2-spawn-return.md — completed with notes.
Verification (all green): cargo test; per-feature dispatch matrices
(--features git/session/tunnel/sftp, --all-features); cargo clippy
--all-targets/-all-features with -D warnings; cargo fmt --check;
cargo doc --no-deps (no warnings); taskgraph validate.
- auth_publickey: ed25519-only gate → single fingerprint path →
resolve_from_fingerprint → accept-with-identity (stored per-
connection, read by wave 3) / reject fail-closed; the gate is
explicit-over-inherited (ADR-002 decision 4) and precedes resolution
- auth_publickey_offered: explicit accept-and-delegate (counting
stays honest, POC-1)
- auth_none / auth_password / auth_keyboard_interactive /
auth_openssh_certificate: four explicit family-contract declines
- username carried by no hook — resolution is fingerprint-only (OQ-03)
- SessionHandler constructible via #[doc(hidden)] re-export (the
w2-server-mount note's widening); resolve_bridge structured out of
the #[non_exhaustive]-arg hooks so contract tests drive the bridge
core directly
- tests/auth_bridge.rs: 21 rows — wire rows over the real adapter
mount (accept, fail-closed reject, username independence, revoke
between attempts, none/password/certificate declines) + direct
rows over the wave-1 doubles
- cert fixture (throwaway ca + alpha-cert.pub) recorded in
fingerprints.txt; MemHostKeySource double in tests/common
Verification: cargo test (76 across the suite), --all-features,
clippy --all-targets (both feature sets, -D warnings), fmt --check,
doc --no-deps, taskgraph validate — all green
- SshAdapter:🆕 decrypt-at-construction host-key load (ADR-005
decision 6) — locked / absent / decryption / unknown-version /
decode all refuse with AdapterError::Construction(KeySourceError
preserved), no adapter; an empty key set refuses as Absent even
from a custom source.
- russh 0.65 server Config built from ServeConfig: methods exactly
{publickey} (MethodSet from [MethodKind::PublicKey] — honest
advertisement, ADR-004 decision 4); host keys ride Config::keys;
Limits knobs (window_size, maximum_packet_size,
channel_buffer_size, max_auth_attempts) one-for-one;
inactivity_timeout always Some (bounded-resources posture). All
other knobs stay russh's default posture: rekey Limits (RFC-4253
defaults, russh-enforced), auth_rejection_time, server_id
(russh default — recorded), server keepalive (client-direction
posture only).
- SshAdapter::handle: ADR-001 mount — generic duplex stream in,
run_stream per stream, run to completion (Result<(), AdapterError>;
no ALPN/relay code; the serving loop is spawned inside russh, so
ADR-006's spawn-and-return holds without double-spawning).
- SessionHandler skeleton (pub(crate)): per-connection
russh::server::Handler with type Error = AdapterError; every hook
at the inherited fail-closed default; carries Arc<ServeConfig> for
w2-auth-bridge / w2-dispatch-decline-core.
- AdapterError (error.rs): Construction + Wire (From<russh::Error>)
— the wave-1 error-model's reserved wave-2 shape.
- Tests: advertisement-exactly-publickey; knob mapping (tuned +
default postures); key-set parity; construction failure matrix;
EOF-on-mount; wire smoke (russh client over duplex: full KEX,
fail-closed auth decline, exactly the {publickey} method list on
the wire).
Verified: cargo test (61 across suites), cargo test --all-features,
clippy --all-targets -- -D warnings (default + all-features),
fmt --check, cargo doc --no-deps, taskgraph validate.
Six implementation tasks + the gate under tasks/implementation/,
chained sequentially (the auth hooks, dispatch, and channel cap all
edit the same per-connection Handler impl):
- w2-server-mount: SshAdapter::handle mount + russh Config
construction from the serve-config (honest advertisement, host-key
decrypt-at-construction, the Limits knob mapping) + the Handler
skeleton at fail-closed defaults
- w2-auth-bridge: the ADR-004 dispositions (ed25519-only explicit
decline, fingerprint-only resolution, explicit declines for every
non-publickey method)
- w2-loopback-harness: the in-process client/server contract-test
vehicle over the wave-1 doubles
- w2-dispatch-decline-core: parse-only dispatch + the fail-closed
decline core, contract-tested per feature build
- w2-spawn-return: the structural constraint pinned by test + the
exit-reporting mechanics via the cloned Session::handle()
- w2-bounded-resources: the in-crate concurrent-channel cap at the
handler surface
- review-wave-2: the gate
The plan carries the wave-2 decomposition record with four
interpretations flagged for the gate (skeleton-level git probe,
declining routing stubs, the adapter error surface, the harness
transport choice). taskgraph validate: 19 tasks, clean.
Review task record: the line-by-line ADR/OQ gate reading, the three
flagged interpretations confirmed (sibling-dep timing, vault-double
shape, policy verdict type), the minor inline fixes, and the green
verification summary. Wave 2 decomposition unblocked.
The `w1-test-doubles` task: the in-memory seams every later wave's
contract tests run against, behind their production seams.
- tests/common/mod.rs — the doubles, test-only (nothing reachable from
lib.rs, no feature): MemIdentityProvider (registered fingerprints ->
alkcall Identity resolutions over the IdentityProvider trait; token
path resolves none per ADR-004), TestVault (a wrapper over alkvault
0.1's shipped in-memory construction — resolving the flagged
vault-double question: wrap, not re-impl), MemHostKeyPolicy
(exact (host, fingerprint) rules + explicit default verdict,
fail-closed by default, inspectable decision log), and the fixture
table. Module docs record the location/vault/fixture decisions and
the row/stamp discipline (greppable Contract stamps).
- tests/vectors/ — one unified fixture set: four ssh-keygen-minted
ed25519 keypairs (committed .key + .pub + fingerprints.txt recorded
from ssh-keygen -lf, OpenSSH_9.6p1). The previous inline PEM
constants in src/key_source.rs were rejected by OpenSSH itself
(russh-only decodable); all keys were re-minted and the overlapping
vector set retired — one fixture set now serves the parity tests,
the custody round-trip, and every later auth/mapping test
(src-unit tests share it via include_str!).
- tests/doubles.rs — the end-to-end rows: register -> resolve,
seal -> source -> decode (+ locked/absent/tampered postures),
host-key set in order, policy verdicts honored-and-logged.
- tests/fingerprint_parity.rs and src/key_source.rs tests moved onto
the shared fixture files; src changes are #cfg(test) only.
Verification: cargo test (33 + 9 + 5 green; --all-features also green),
cargo clippy --all-targets -- -D warnings clean, cargo fmt --check
clean, taskgraph validate ok (12 tasks).
- HostKeyPolicy trait: async, dyn-compatible (Arc<dyn> handle, the
alkcall injected-handle pattern) — decide(&self, &PresentedHostKey)
-> bool with host/port/fingerprint as the decision input
- Verdict type pinned to the russh 0.65 check_server_key shape:
bool is the trust decision; decline reasons stay with the policy
(declines are dispositions, not errors). Flagged for the wave-1 gate
- Built-in default RejectAll: fail-closed reject-all (russh's default,
kept); no accept-all option exists in the crate
- async-trait 0.1 added for the dyn-compatible async handle
(alkcall-precedented; tree-deduped). Flagged for the wave-1 gate
- Tests: default rejects; custom verdict honored; both through the dyn
handle; the whole presented context reaches the policy
Verified: cargo test (14), cargo test --all-features, cargo clippy
--all-targets -- -D warnings, cargo fmt --check, taskgraph validate
- KeySourceError with exactly five variants (Locked, Absent,
Decryption, UnknownKeyVersion, Decode) — ADR-005 decision 4's
failure matrix as distinct shapes, the vault taxonomy reshaped
never collapsed; no catch-all, no Other/Unknown
- payload shapes pinned: Locked/Absent payload-free;
Decryption/UnknownKeyVersion carry the vault's opaque messages;
Decode carries a message so the RC-pinned ssh-key error type
never enters the public API (flagged for the wave-1 gate)
- each variant doc-commented with ADR-005 semantics + fail-closed
consequence; module stays engine-blind (no vault/russh types)
- no From<VaultServiceError>: non-mappable vault variants would
force a collapse; w1-key-sources maps explicitly at its seam
- exhaustive-match + Display/Debug/Clone unit tests
Verified: cargo test (default + all-features), cargo clippy
--all-targets --all-features -- -D warnings, cargo fmt --check,
cargo doc --no-deps, taskgraph validate
glm-5.3-flash