Commit Graph
55 Commits
Author SHA1 Message Date
ab b4f3e57c8d Implement fast userspace multihop mesh routing
Replace the one-intermediate-peer relay with protocol-scoped connectivity
graphs and precomputed shortest-path/ECMP forwarding snapshots. Independent
transport readers forward opaque transit frames without a plugin or TUN
round trip. Carry source, destination, a bounded hop limit and stable flow
tags; preserve end-to-end WireGuard links across topology changes.

Classify IP flows before encryption and preserve their tags through the
WireGuard pending queue. Add offline four-agent path-change coverage, loop
and isolation tests, and an opt-in release forwarding microbenchmark. Bump
control/data ALPNs while preserving persistent network identities and state.

Also include the pending Windows Mainline idle-timeout fix and its regression
test, using a reproducible vendored dependency patch.

Validation: fmt, workspace Clippy with warnings denied, and 307 release tests
passed. Two pre-existing Windows SQLite wipe failures were excluded; public
DHT and the manual benchmark remain ignored by default. The forwarding
microbenchmark measured 103 ns (64 B) and 202 ns (1280 B) per transit packet,
excluding encryption and socket I/O.
2026-09-22 18:08:26 +03:00
ab d1a0eca723 Fixec join CLI 2026-09-22 16:32:39 +03:00
ab 686c74a3bd Enabled DNS by default 2026-09-22 16:08:06 +03:00
ab 9698f21d55 Added DHT peer resolver, fixed MTU 2026-09-22 15:44:33 +03:00
ab 72eaf9a228 Fixed win dns 2026-09-22 13:32:37 +03:00
ab e735151d62 Added windown support 2026-09-22 12:34:19 +03:00
tsunagiandClaude Opus 5 458051f47d Warn about a zone name only when it collides with something
"`.pidar` is not a delegated top-level domain today, but it could become
one" fired on every private name anybody has ever picked, which is every
network without a dot in its name. A warning that is always there is a
warning about nothing, and it teaches people to skim past the ones that
mean something — there were two of them in one report, side by side with
the real checks.

What is left is the collision that exists: a name that really is a public
top-level domain, which does make every public name under it unreachable
from that host, and `.local`, which belongs to multicast DNS. A name that
shadows nothing is said nothing about.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-22 02:09:17 +01:00
tsunagiandClaude Opus 5 83d3445b7e Meet everybody, not just the one you were told about
A device pointed at one member talked to that member and nobody else. The
only candidates an agent had were the ones on its command line and
whatever the cache remembered, so the network was a star around whichever
peer happened to be typed — while the signed state sitting in front of it
listed every other member by name.

Two sources fix that, and both produce candidates rather than facts.

Every author of a signed record is somebody to try. Those records reach us
through anybody, so a member is known to exist, and by id, long before it
is ever spoken to; an id with no address is still dialable where the
endpoint's own discovery can resolve one.

And members tell each other where they have seen the others. A
`ControlMessage::Peers` carries each member with the addresses the sender
observes for it — including the sender's own, which is the one thing
nobody else can pass on — in the same `ip:`/`relay:` spelling the cache
already uses, so one decoder serves both and neither can drift. An agent
that only ever accepts has no candidates of its own and is exactly the one
everybody was pointed at, so the addresses come from the live sessions as
well as the candidate list.

None of it authenticates anything. An introduction is not a vouching: the
handshake decides membership as before, and a candidate from a member is
tried exactly like one from a bootstrap entry or the cache. It is also
deliberately the shape a distributed hash table lookup would return, so
that becomes another source beside these rather than a redesign.

With the mesh pairwise, the relay is what it was meant to be: the way to
the one peer that cannot be reached directly, not the way the network is
held together.

Covered by three agents where two are told only about the first: each ends
up with both of the others, and the one nobody mentioned arrives as an
introduction.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-22 01:59:50 +01:00
tsunagiandClaude Opus 5 3581feb9b9 Reach a peer through one that can reach both
Two members of a mesh could both reach a third and not each other, and
that pair was simply lost to one another: a packet for a peer with no data
link was counted undeliverable and dropped. Now it goes through a member
that has both.

What travels is not routes. Each agent says only which peers *it* has a
live link with — first-hand, over the control plane, one hop, never a
claim about somebody else's reachability — and everybody computes their
own way through from that. The choice is local and deterministic (the
lowest endpoint id among the peers that have a link to the destination),
so there is nothing to agree, nothing to elect, and two agents may well
route each direction differently. It is soft state: repeated while it
holds, expired when it stops, so a relay that disappears stops being
chosen without anybody revoking anything.

The one in the middle carries bytes it cannot read. A datagram is wrapped
with the peer it is for, and unwrapped on the other side into the link for
the peer it came *from* — which matters, because a packet attributed to
the carrier would be dropped as coming from an address the carrier does
not hold. The tunnel stays end to end, and the relayed datagram goes link
in, link out: it never reaches the middle's interface, so no routing,
forwarding or firewall setting of that host is involved. One hop, so a
loop cannot form without counting anything.

A protocol is handed one link per peer that now outlives the paths under
it. A direct link that dies, a hop that changes, a direct link that comes
back: none of it tears down a tunnel any more, and the size a protocol may
use does not change with the path. Where there was never a direct link at
all, the link exists anyway as long as a hop does, so a peer reachable
only through somebody still gets a tunnel.

The data ALPN is `tsunagi/data/2`: every datagram now carries a tag saying
whether it is direct, for somebody else, or from somebody else. The local
control protocol is 13, for the relay counters — what this device carried
for others is their traffic on its uplink, and that should not be
invisible. `status` says `via <peer>` on a path through somebody.

Fairness between the peers a relay carries for is deliberately not here
yet: the queues are bounded and the counters are what a limit would be
built on.

Tested with fake links for the mechanics, and end to end with three real
agents — two that cannot reach each other directly, a real WireGuard
packet crossing through the middle. The one arrangement a single host
cannot produce by itself is a pair that cannot see each other, so that is
a `testing`-only switch on the agent config and exists in no release
build.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-22 01:32:43 +01:00
tsunagiandClaude Opus 5 3044e592bd Say when there is nobody to contact
Two freshly wiped devices joined the same network, each got an address,
and nothing happened. The report said "none known yet; nobody else has
joined", which reads as patience — as if somebody were expected and had
not arrived. What had actually happened is that neither agent had anywhere
to look: this project publishes nothing about who is in which network, so
a first meeting needs one of them to be told the other's endpoint id, and
the hints an agent remembers from earlier sessions had gone with the wipe.

Candidates are now in the report, and having none of them with nobody
connected is said plainly, with both ways out of it and this device's own
id ready to hand to the other side. Having some and no sessions yet is the
ordinary state of a network coming up, and stays ungraded.

The local control protocol is 12.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-22 00:51:39 +01:00
tsunagiandClaude Opus 5 9b240672e6 Put every network's address on the interface, and split up from join
Two networks on one agent, and only one of them worked. The interface
plan is exhaustive by contract — it is what the interface should carry and
nothing else — but the request that built it held a single address, so the
provisioner was told about the first network and took the second one's
address off, or never put it on. On the host that is a network whose
address the operating system has never heard of: the tunnel is up, the
status says all is well, and nothing routes. The request now carries every
address, which is also what takes one off when a network is left or
stopped.

The other half is the command line. `up --network X --secret Y` and
`network join` were two ways to do the same thing, and the one on `up`
could only be undone by restarting — which is how a network somebody left
came back, and how an invite line told the other side to start their agent
with a network baked into it. So they are one thing now, split the way the
system is: **`up` runs the agent** — the device's one process, serving
whatever it has joined, answering `status`, taking instructions — and
**`join` decides what it belongs to**, at any time, while it runs. `join`
is at the top level because it is what gets typed; `network join` is the
same command for anyone who likes the long form.

Every line that told somebody to type the old form is gone with it: the
invite after making a network, the lock error from a second `up`, the
empty-network hint in `id`, the README walkthrough and the WireGuard
document. The invite now prints the `join` line for the other machine and,
separately, the `up --peer` line for an agent that is not running yet —
two commands, because they really are two, and no amount of wording makes
starting an agent the same thing as joining a network.

Joining says how the network stood before: new, already here, or stopped
and now running again. That last one matters — joining is an instruction
to run it, so it undoes a stop, and a pause that ends without a word is a
pause nobody can rely on.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-22 00:30:03 +01:00
tsunagiandClaude Opus 5 1b2f050c05 Start the agent without deciding anything yet
`up` demanded a network, so there was no way to run the agent in one
terminal and decide what it belongs to in another — which is the shape of
the thing now that networks are joined, stopped and left while it runs.

`--network` is optional. Without it the agent starts with whatever it is
already configured for and waits; the banner counts the networks instead of
naming one, and points at `tsunagi network join`. A secret with no network
is refused rather than ignored, because it says nothing on its own.

The periodic summary, which had one network by construction, now falls back
to the first running one — `tsunagi status` is the whole picture and this
line was never more than a glance.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-21 23:36:36 +01:00
tsunagiandClaude Opus 5 637e2f74e4 Tell being away from giving up
Leaving was the only way out of a network, and it is the irreversible one:
it publishes a release and then removes the configuration, the secret, the
network's signed records, its cached hints and the protocol key it used.
What somebody usually wants before a reboot, a trip or an experiment is
the other thing — stop serving it and keep everything.

`tsunagi network stop <id>` closes that network's sessions, takes its
address off the interface and keeps it from starting again. Nothing is
announced, deliberately: to the others this device is away, which is an
ordinary condition they already handle, and the address and name it holds
stay reserved for it. `tsunagi network start <id>` resumes it where it left
off. Both are remembered, so a restart does what the last instruction said
rather than what the last command line happened to say.

Except when the command line says otherwise: `up --network X` starts X
whatever its stored state, because a command naming a network is an
instruction to run it. The banner now says which of the three happened —
`new`, `already here`, or `was stopped; this command starts it` — since
silently, that is a stop that comes back from the dead with nothing to
explain it.

The listing tells the three states apart too: running with its address,
stopped and kept, or configured and waiting for an agent to start. Each row
says what to type to move it, because "stop" and "leave" are a pair that
has to be easy to tell apart before the irreversible one is typed.

The local control protocol is 11.

Covered end to end against a running agent: stopping leaves it configured
and says so, stopping twice is the state asked for rather than an error,
starting brings it back, and the secret afterwards is the one from before —
so it is the same network and not a lookalike.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-21 23:32:23 +01:00
tsunagiandClaude Opus 5 415b6a6667 Make a network on the spot, and say which one you just started
Two reports of the same shape: a network was left and came back after a
restart, and `network join` asked for a secret it could have invented.

The first was not a bug in leaving. The secret on the start command line
derives the network id, so a command line carrying the secret of a network
you have just left recreates it on the next start — which is right, it says
to join that network, but nothing on screen said so. `up` now marks the
network `· new` or `· already here`, and warns in full when another
configured network answers to the same name. A name is a label; the id is
the identity, and the secret is what decides which of them this is. Said at
the moment it happens it is obvious; discovered later in a status report it
is a mystery, which is exactly how it went.

The second was an omission: `up` had learned to invent a secret and
`network join` had not, so the quickest possible thing — a network with
somebody for as long as it is needed, then gone — still needed a secret
generated first. Both now resolve a bare name the same way: the one network
of that name this device already has, or a fresh random secret when there
is none. It is printed in full, with the single line the other person can
paste as it stands, endpoint id included, because a secret nobody can read
is a network nobody can join.

The id is printed in full by both answers now. The shortened form belongs in
a report, where it is read; this one gets copied into the next command.

Covered end to end against a running agent: joining with no secret prints a
secret and a pasteable command with a peer in it, and joining a name this
device already has resumes that network instead of making another that
merely looks the same.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-21 23:19:58 +01:00
tsunagiandClaude Opus 5 0f97d60854 Serve a zone per network, and make a network in one command
Twice now a report has read "dns not serving" and been taken for a broken
resolver. It was accurate both times: the agent had been started without
`--dns`. That is the flag's fault, not the reader's — a resolver that
disappears because one word was not retyped is worse than none, since the
names simply stop working. So the setting belongs to the device now: `--dns`
turns it on and it stays on, `tsunagi dns off` turns it off, and
`tsunagi dns on` turns it on for an agent that is already running, without
restarting it. `tsunagi dns` says what it is doing, or what it will do at
the next start when nothing is running.

One agent has one identity and as many networks as it likes, so one DNS
service serves them all: each network is a zone named after it, and joining
or leaving one changes what resolves with no restart. A question carries a
name and not the network it belongs to, so the suffix decides and nothing is
shared between zones — a member of one network is not a name in another.
`--dns-zone` is gone with that: there is no single zone to name any more, and
a network name may contain dots, so `--network lab.internal` is how you get
`music.lab.internal`.

It listens on loopback only, where it always could have. Binding the overlay
address put the zones in front of the whole mesh, and with several networks
on one agent that would have answered one network's questions about
another's names.

That made a gap plain: a second network on an agent had no addresses at all,
because the configured range belongs to whichever network took it first, so
its members had nothing to allocate from and no names to answer with. A
second network now uses the range **derived from its own network id** —
every member derives the same one from something they all already have, so
it is an agreement rather than a local invention. It is held back for a
moment first, because a network that already exists has a range of its own
and a joiner should adopt it rather than argue; that wait is what keeps
"the first member settles it" true.

And a network needs no ceremony to start. `tsunagi up --network lab` with no
secret resolves the obvious way: the one network of that name this device
already has, or — when there is none — a fresh random secret, printed in
full with the single line to send the others. That is the ad-hoc case, one
person makes a network and passes the command round, and it was previously
two steps with a flag people could not find. The secret is printed only when
the agent invented it, because then there is nowhere else to read it from;
one that was supplied is not echoed. Two networks of one name and no secret
is the one case with no answer, and it says so rather than choosing.

Releasing now also stops this agent claiming again. The periodic check would
otherwise publish a fresh claim in the moment between the goodbye and the
teardown, turning a release into a hello nobody asked for.

Exercised with the real binary: a zone per network as a second one is joined
into a running agent, the resolver switched on and off while it runs, and an
ad-hoc network printing its secret and the line to share.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-21 23:03:42 +01:00
tsunagiandClaude Opus 5 44a799faee Split the command line along the line the system draws
`id` had grown into the place where everything was shown and changed,
including the secret of every network this device had joined — and it
printed them all in its ordinary overview, which is a poor default for
output that gets pasted into chats and issue trackers. Now that networks
have a command of their own, the boundary is the one the system already
has: `id` is this **device**, `network` is what it **belongs to**. A device
outlives every network it is in and a network outlives any device in it, so
a command that mixed them had to be read twice.

`id` keeps the key, the name and the directories, and says how many
networks there are without naming their secrets. `network secret` prints
one, or all of them, and only when asked. Nothing else ever does.

`network join` is the part that was missing entirely. One state directory
is one identity and one live agent, so a second `tsunagi up` on it is
refused — and until now that refusal was the end of the road: a network
could be left while the agent ran but never added. It goes over the control
socket, takes effect at once, and is idempotent, saying which of "joined"
and "already there" happened. With no agent running it is written to the
configuration and starts with the next `up`, and says so rather than
implying it is live. The secret travels over an owner-only socket to the
agent that stores it anyway, and `Request` has a hand-written `Debug` that
redacts it, because a derived one would put it in any log line that printed
a request.

The lock error from a second `up` now answers the question behind it: add
the network to the running agent with one command, or run a genuinely
separate agent — a second identity, with its own directories, interface and
range — with the other. That is the shape of the thing: one agent per
identity, many networks on it, one interface; a second agent is isolated,
not a second view of the first. AGENTS.md carries that as a boundary now,
since it is the kind of thing a change could quietly break.

The local control protocol is 9.

Exercised against a running agent: a second `up` refused with both routes
named, a network joined into the live agent and answering for status at
once, the same one again reported as already there, a same-name network
with a different secret joined with the warning, and `id` showing three
networks and no secrets.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-21 22:16:57 +01:00
tsunagiandClaude Opus 5 41604225ba Let a device leave a network, and start over
Joining was one command and leaving was nothing at all: a network went into
`state.sqlite` on the first `up` and stayed there, so a mistyped secret
left a second network beside the working one with no way to remove it but
editing the database by hand.

`tsunagi network` lists what this device belongs to. `tsunagi network leave
<id>` publishes a signed release first — while the agent is running and its
sessions are up — and only then deactivates the network and removes it. The
order is the whole point: signed state has no expiry, so the tombstone is
the only thing that ever frees the address and the name for the others, and
after the network is gone there is nothing left here to sign one with.
Peers pass it on, so a member that was away hears it from them rather than
from an agent that has already left.

With no agent running nothing can sign or send, and the command says so
instead of quietly succeeding: `--offline` drops the network locally and
says plainly that the others keep the old claim. The outcome always
distinguishes "published to nobody" from "not published at all", because
they leave the network in different states.

A network is named by its id, and a unique prefix will do. The name is
refused on purpose: two networks can share one — that is exactly the
situation this command exists for — and picking between them for the user
is how the wrong one gets left.

The author's version counter deliberately survives. Rejoining the same
network with the same key must continue above the release, or every replica
that holds the release would treat the new claim as stale and the returning
member would be invisible for good. The protocol key does not survive:
rejoining is joining, not resuming, and coming back with a key the network
was told to let go claims an identity nobody holds any more. Plugins learn
about it through a new `on_network_forgotten`, which is about what outlives
a session rather than what a deactivation tears down.

A released member also drops out of the roster `status` prints. The
tombstone stays in the record set — a replica that never heard of it would
otherwise reinstate the old claim — but listing an author that gave
everything up as a member made leaving look like a peer that had broken.

`tsunagi wipe` is the other half: it empties both directories, so the
device identity, every network, every signed record and everything a
protocol kept beside them go at once and the next start is a stranger. It
refuses while an agent holds the directory, and refuses a directory with no
`state.sqlite` in it, so a mistyped `--state-dir` cannot take somebody's
documents with it. Without `--yes` it only prints what it would remove and
what membership would be lost. It is not a goodbye and says so: leaving the
networks first is what frees their addresses.

The local control protocol is 8 — the socket carries a `Leave` request now,
since only the running agent can publish the release.

Exercised end to end against real agents: leaving by prefix released the
address to a connected peer, leaving by name was refused, `--offline` was
refused until asked for explicitly, wipe was refused while the agent ran,
and the directory afterwards had no identity in it.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-21 21:54:05 +01:00
tsunagiandClaude Opus 5 fae3816bbf Answer DNS over both families, and only for our own interface
Questions now arrive over IPv4 or IPv6, whichever the resolver uses. The
server opens one listener per family — the overlay address or `127.0.0.1`,
and `[::1]` — and all of them are published to systemd-resolved in one
call, which is what that call requires: sending them one at a time leaves
only the last. A family that cannot be bound, IPv6 switched off in the
kernel for instance, no longer stops the other from answering.

The answers stay IPv4, because that is what the overlay is. A listening
address is disposable, unlike an address a member holds in signed state,
so serving one family over the overlay and the other over loopback costs
nothing and loses nothing.

`--no-tun` was also configuring the host. An in-memory interface has a
name and an MTU and nothing else, but everything downstream read that name
as a host interface: the resolver setting was pushed onto whatever else on
the host happened to be called `tsun0` — which, with two agents on one
machine, is another agent's live interface. A factory now says whether
what it creates is on the host, and the resolver setting goes only to an
interface the agent created. For the same reason the complaint that "the
allocated address is not on any interface" no longer fires under
`--no-tun`, where there was never going to be one; it had people looking
for something that had removed their address. The status line says
`tsun0 (in memory, --no-tun)` rather than printing an address beside a name
the operating system does not have.

That distinction also corrected a test that used the in-memory interface
as a stand-in for an unconfigured host interface. They are not the same
case, so the test now uses a factory that claims the host and puts nothing
there — a provisioner that reported a success it did not achieve — and a
second test covers `--no-tun` being an arrangement rather than a fault.

An in-memory device now reports end of stream when it is destroyed. It
never did, so the packet loop reading it could not end, and since shutdown
became bounded that cost every `--no-tun` agent the full five-second grace
before the loop was aborted instead of finishing.

And `status` says when there is no local resolver at all. Its absence is
the answer to "why does this name not resolve?", and leaving the section
out made a report with DNS switched off look exactly like one where it was
running.

The local control protocol is 7: `DnsReport` carries a list of listening
addresses and `OverlayReport` says whether the interface is on the host.

Verified against the running systemd-resolved: it takes
`127.0.0.1:5354 [::1]:5354` on one link in a single call, and forward and
reverse questions for a peer's name are answered identically over both
transports.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-21 21:21:55 +01:00
tsunagiandClaude Opus 5 0b3915d52b Bound every wait that could last for ever
Nine orphaned test processes were found still running from the day before,
three of them spinning on a core each for twenty hours. The code they ran
is several changes old and the mesh test passes twenty times over now, so
the wedge itself is gone — but nothing in the way it was waited on was
bounded, which is why a wedge lasted a day instead of failing a run.

The harness enforced its deadline only between probes. A probe that never
returned — one call into a wedged runtime, which is exactly what a status
request is — waited for ever inside the deadline it was supposed to obey.
The probe is now bounded too, so the same wedge fails the test in thirty
seconds.

Shutdown claimed to be bounded and was not. The plugins had a grace
period; the network runtimes, the accept loop, the plugin request loop and
the endpoint close did not, and a peer that stops reading is enough to
hold any of them open. Each now gets a grace period and is aborted after
it. The overlay packet loop was not stopped at all: it ends when the
device reports end of stream, which a live interface never does, so it
outlived the interface it was reading. And a plugin's grace period
abandoned the future without stopping the task behind it, so the helper
is public and `wg-quic` uses it on its own runtime.

The local control socket was unbounded in both directions. A wedged agent
left `tsunagi status` hanging with nothing on screen and no way out but
Ctrl-C; it now says the agent did not answer, after five seconds, and
falls back to the state store as it already did for a socket that refuses
a connection. On the serving side, a connection that sends no request no
longer holds a task open.

Tests cover the mechanism — a task that stops on its own is not aborted,
one that ignores the grace is cut off and drops what it held — and both
sides of the change in behaviour: a probe that never answers fails its
deadline, and a silent agent is reported rather than waited out.

Also: the binary opts out of rustdoc, since it shares a name with the
library and `cargo doc` cannot put both in one directory.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-21 20:41:19 +01:00
tsunagiandClaude Opus 5 4c84cc9e4b Tell two networks of the same name apart
A status report with two sections both headed "network LAB" reads as one
network that is somehow working and empty at once. It was two networks:
the same name with different secrets, which is two different networks
that share nothing, because a network's identity is its name *and* its
secret.

Three fixes for the one confusion.

The heading now carries the network id, so the sections are plainly
different things. A name is a label the user chose; the id is the
identity.

Joining a name that is already configured with another secret says so, at
the moment it happens, because that is almost always a mistyped secret
and until now it silently produced an empty network sitting beside a
working one. `status` flags it too, for the case where it already
happened.

And the second network's emptiness now says why. It had no address
because the only configured range was already taken by the first — one
agent has one interface, so an address belongs to one network — and
"nobody else has joined" pointed at the wrong thing entirely. It now
names the range it cannot have, the reason, and the flag that gives it
one of its own.

Nothing was wrong with the connectivity: the working network's tunnel was
up and its ping was answering throughout.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-21 20:24:11 +01:00
tsunagiandClaude Opus 5 990b9f2e0f Describe the layers as they now stand
The module table still had the plugin inside the core and no mention of
the overlay or the DNS view, and the stale path in the testing notes
pointed at a directory that had moved.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-21 19:57:27 +01:00
tsunagiandClaude Opus 5 142fdf995c Make the protocol a crate of its own
tsunagi-wg-quic. The line between a protocol and the system level is now
drawn by the compiler: nothing in it can reach into tsunagi beyond what
tsunagi makes public, and it carries its own version — which is not the
version peers compare.

Two things the compiler found the moment the boundary was real. The key
store was reaching into the core's `pub(crate)` file-permission helpers;
those are a legitimate service of the system level, because a protocol
keeping keys on disk has the same obligation the agent does, so they are
public now with that said. And the test harness was about to be copied
into a second crate, which is how two copies start to drift; it is a
`testing` feature of the core instead, which is also what anybody writing
a protocol would need.

The bridges put up while things were moving are gone: the error
conversion between the two levels, and the re-exports of the system
level's types from the protocol crate. Imports now say which level they
come from, which is the point.

One deliberate deviation, stated rather than hidden. The authenticated
transport stayed in the core. Moving it would have meant handing a
protocol the network's keys so it could prove membership itself, and a
plugin that can authenticate on the control plane is a worse trade than
a module boundary is worth. So the core proves who is at the other end
and the protocol owns what is said over it — the same separation, without
the secret crossing.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-21 19:55:30 +01:00
tsunagiandClaude Opus 5 ff7e235414 Split the command line by level
`up` now says which level each setting belongs to, and `--help` shows the
two sections. System: how the agent reaches peers, the one interface it
owns, the address range, the resolver. Transport: which protocols carry
packets and what they take.

`--wireguard` is gone. `--protocol` takes a list and defaults to
`wg-quic`, which is what the protocol is now called — WireGuard's
cryptography in QUIC datagrams, so the name says what is on the wire
rather than what the implementation borrows. `--protocol none` runs the
control plane alone.

Protocol settings moved to `-o key=value`, or `-o protocol:key=value`
when several are selected. Each protocol declares its own settings and
their help, so `tsunagi protocols` can list them without the agent
knowing anything about any protocol, and a setting nobody takes is
refused rather than dropped — a dropped setting looks exactly like one
that did not work. What the user asked for is checked before anything
that could fail on its own, so a misspelled protocol is not buried under
a privilege error.

`--wg-prefix` and `--wg-mtu` became `--interface` and `--mtu`: they were
never the protocol's, and the interface they describe belongs to the
agent. `--transport` became `--reach`, because "transport" now means the
protocol level and using the word for iroh's path policy as well would
be a collision of meaning rather than a shortage of words.

The plugin gave up the last things that were not its own: the interface
name it carried in its own state, and the check that this agent's
address is really on an interface. Both are the agent's, and the check
is now the agent's too, still said once per address rather than every
round.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-21 19:44:21 +01:00
tsunagiandClaude Opus 5 7c1be332e3 Agree a protocol by name and wire version
A peer's announcement already carried a protocol and a version; only the
name was being checked. Now both are, and a peer offering a protocol at a
version this build does not speak simply has no data plane — the control
plane keeps working, messages and signed state still flow, and the
difference is reported once rather than on every announcement.

The version compared is the *wire* version, not the software version, and
the trait says so: a plugin crate has its own version and it is nobody
else's business. Two peers on different releases work together for as
long as the bytes between them have not changed, and nothing in the
negotiation may be derived from anything that moves with a release. A
test pins that agreement turns on the name and version alone, with a
peer whose announcement carries a payload this build has never seen.

`PeerStatus` gained the protocols agreed with each peer, so an empty list
is visible as what it is: a session that is up, carrying control traffic,
with no protocol in common.

The forging test plugin was announcing version 1 while claiming to speak
the current one, so its payload was being set aside for the wrong reason.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-21 19:34:38 +01:00
tsunagiandClaude Opus 5 9415866193 Take the interface off the protocol and give it to the agent
One agent, one interface. The plugin no longer creates one, no longer
holds a TUN factory, no longer keeps a routing table and no longer
decides who owns an address. What is left of it is the protocol: a
WireGuard key per network, a tunnel per peer, encryption on the way out
and decryption on the way in.

The packet path is now explicit about where each decision lives. Out: the
agent's interface reads a packet, the routing table says whose
destination it is, and each protocol is asked in turn whether it can
carry it there. In: the protocol decrypts and hands the packet up with
the peer it came from attached, and the agent checks that peer is
entitled to the source address before writing it out. A protocol proves
who; only the system level knows what they may say.

Two things found by making it work.

`carry` sent the packet unencrypted at first. The encryption had lived in
the interface loop that moved to the core, so taking that out quietly
removed it — the receiving end rejected plaintext as a bad WireGuard
datagram and the counters said nothing at all. Encryption belongs with
the protocol and is now there, with packets dropped for having no session
yet counted apart, because a handful while a tunnel comes up is normal
and a number that keeps climbing is not.

An agent could impose a range it could not itself route. With one
interface two networks need different ranges, and "the lowest author's
range wins" would have carried one agent's colliding default to
everybody. The configured range is now reserved when a network is
activated — on the serialised path, so the answer does not depend on
which task ran first — and an agent that cannot have it proposes nothing
and adopts whatever the network settles on.

Leaving a network takes its address off the interface and leaves the
interface; the interface goes when the agent does.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-21 19:20:30 +01:00
tsunagiandClaude Opus 5 c852de2c78 Move packets across the interface at the system level
The loop that reads the interface, decides whose packet it is and hands
it to whatever can carry it — and the other direction, where a packet a
protocol decrypted is checked and written out.

Neither direction knows which protocol is involved. The interface asks
for a packet to reach a peer and is told whether that was possible;
`PacketCarrier` is the whole of what it knows about protocols. That is
what lets several be live at once without any of them owning the
interface they are carrying traffic for.

The source check stays here rather than in a protocol, and the split is
the point: a protocol proves *who* sent a packet, and only this level
knows what that member is entitled to say, because entitlement is the
signed claim.

Four kinds of drop are counted apart, because they want different
answers: a destination nobody holds (with the first such address kept, so
the number can be acted on), a destination that is known but has no live
protocol, multicast the operating system emitted anyway, and a packet
that could not be read. Rolled into one counter they would say only that
something is wrong.

Not wired in yet: the WireGuard plugin still owns its own interface, and
that is the next commit.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-21 18:54:52 +01:00
tsunagiandClaude Opus 5 a80a014f20 Decide at the system level whose packet this is
The routing table, which is what makes one interface able to serve
several protocols. A packet coming off it could belong to any network the
agent is in and to any protocol currently carrying traffic; the answer
comes from signed state, which no protocol owns, so this is the right
level for it.

Two questions, deliberately not the same one. Outbound: whose is this
destination — and a packet for nobody is dropped rather than flooded,
because a tunnel is not a broadcast domain. Inbound: this peer decrypted
a packet claiming this source, is that address actually its — checked
against the signed claim and never against anything the peer said.

A packet addressed to this agent itself routes nowhere, rather than to
whichever peer happens to be listed.

One interface means an address belongs to one network, so two networks
whose ranges overlap are refused with the reason and the fix. Guessing
between them would hand somebody's traffic to a stranger. Nested ranges
count as overlapping, which is the case the obvious comparison misses.

Not wired in yet: the interface loop that uses it comes next.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-21 18:51:24 +01:00
tsunagiandClaude Opus 5 41d5f554c7 Describe the layers the way they now are
The module documentation still said addresses were derived from a
WireGuard key and that the plugin owned the interface. Both are now
wrong, and rustdoc caught it as broken links to modules that had moved.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-21 18:42:14 +01:00
tsunagiandClaude Opus 5 745bbaea06 Drop IPv6 from the overlay
The overlay address was derived from a WireGuard key, which makes it the
protocol's address — and the whole point of the interface belonging to
the system level is that every protocol carries traffic for the *same*
addresses. A derived-per-protocol address cannot be that.

So the overlay is IPv4 only: allocated at the system level, signed by the
member that holds it, and the same address whichever protocol happens to
be moving the packets. The derivation, its ULA prefix and its constants
are gone, along with the collision rule that existed only because a
derived IPv4 address has too little room to be unique — an allocated one
is unique by construction.

A real loss came with it and is restored explicitly. The announcement was
bound to its network only as a side effect of checking the derived
address, so removing that check removed the binding. It now carries the
network id and rejects a mismatch. Strictly redundant, because a
capability arrives on a session that already proved membership, and kept
because losing a property silently is the wrong way to lose one.

An unlock falls out: the MTU floor of 1280 existed because Linux tears
IPv6 down below it. Without IPv6 the floor is 576, what every IPv4 host
must be able to reassemble, so a relayed path with small datagrams can be
matched rather than warned about. The default stays 1280.

The test that forged an overlay address now forges a network id, which is
what is left to lie about. One flaky assertion fixed while passing: it
waited for "the interface has some address", which is briefly true of the
leftover it was meant to see replaced.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-21 18:40:49 +01:00
tsunagiandClaude Opus 5 5bee148497 Move the overlay interface to the system level
One agent, one interface, owned by the agent rather than by a protocol.
That is what makes several protocols able to be live at once: a packet
leaving the interface is routed to whichever peer owns its destination,
over whichever protocol has a link to that peer, and neither protocol
has to hold the address because the agent holds it.

This commit moves the pieces without changing behaviour: provisioning,
the TUN itself, IP header parsing and interface naming are now
crates/tsunagi/src/overlay, and the WireGuard module re-exports them
while its callers are moved over. They were never WireGuard-specific —
netlink, capabilities and `ip tuntap` have nothing to do with the
protocol running on top.

They also get their own error type. An interface that cannot be created
is not a plugin failing, and now that the two belong to different levels
they should not share a word for it.

Routing, addressing and the reduced plugin contract come next.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-21 18:09:57 +01:00
tsunagiandClaude Opus 5 60e6b263d1 Split the system level and the command line into a workspace
First step of separating the layers. The library and the binary are now
crates/tsunagi and crates/tsunagi-cli, which means the plugin crate to
come can be told apart from the core by the compiler rather than by
discipline.

Falls out of it immediately: the CLI's dependencies stop being features
of the library. clap, anstream and tracing-subscriber were optional
dependencies behind a `cli` feature that every library user had to
remember to turn off; now they belong to the crate that uses them, and
the library defaults to no features at all.

The one test that drives the binary moved beside it — a library cannot
depend on a binary built from a crate that depends on the library — and
was rewritten against the public API instead of the test harness.

AGENTS.md said to prefer one crate. It now says the system level and its
plugins are separate crates, for the reason above, and that everything
else stays one crate.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-21 18:05:42 +01:00
tsunagiandClaude Opus 5 ca8759c023 Say the resolver refusal once, and hand over the fix
Running it for real turned up the predicted polkit refusal —
InteractiveAuthorizationRequired — and two things wrong with how the
agent handled it.

It logged the same line every two seconds. A condition that persists is
worth saying once, so it is now repeated only when the message changes.

It also retried at that pace. A refusal will not lift until somebody
grants permission, so retrying it as often as everything else is noise:
refusals now back off to five minutes, other failures to fifteen
seconds, and either resets the moment it succeeds or the desired setting
changes.

The more useful part: the agent prints the polkit rule that grants it,
ready to paste, naming the user it is running as. polkit decides by user
and not by capability, so this genuinely cannot be arranged from inside
the process — which makes "write a polkit rule" the user's work, and
handing them the rule rather than describing it is the difference
between a minute and an afternoon. It grants the four actions the agent
calls and nothing else; a test pins both halves of that, and that the
JavaScript stays within what duktape implements.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-21 17:11:37 +01:00
tsunagiandClaude Opus 5 75b37fdda3 Resolve overlay members by name
`--dns` serves a zone for the network's members, built from signed state,
so a member that is switched off still resolves — its claim outlived the
session. IPv4 only, as agreed: the IPv6 overlay address derives from a
key that travels in live announcements, so it cannot be answered for an
absent member, and answering for some and not others depending on who is
online is worse than not answering.

On Linux the agent tells systemd-resolved where to ask, over D-Bus.
SetLinkDNSEx carries a port, which is why the server needs neither port
53 nor CAP_NET_BIND_SERVICE; the suffix goes in as a routing domain and
the link's default route is cleared, so this never becomes the resolver
for anything else. The setting is keyed to the overlay interface, which
goes with the agent, so it cleans itself up.

That step needs permission CAP_NET_ADMIN does not give — resolved asks
polkit, and polkit decides by user, not by capability — so it is
reported as its own kind of failure with its own remedy. The server runs
regardless and status prints the exact dig line: the automatic part is
what is missing, not the feature.

The zone name is the user's to choose. One shadowing a real public
domain is reported and then used, because that is a decision; the
warning knows the IANA list, says something different about `.local`
where the clash is with mDNS, and stays quiet for names reserved for
private use.

Two bugs found by running it, both in the supervisor and neither
reachable from a unit test, so tests/dns_service.rs drives the real
binary. It bound to the allocated overlay address without checking that
address was on an interface — with --no-tun it never is — and left the
feature silently dead; it now tries the overlay first and falls back to
loopback. And it compared the address it got against the address it
wanted, which never matched when the preferred one could not be bound,
so it tore the listener down every two seconds; it now compares what it
tried.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-21 17:05:24 +01:00
tsunagiandClaude Opus 5 240e471c88 Answer DNS questions about the overlay
The zone and the server, without any of the operating system yet.

`dns::zone` decides what the answer is and knows nothing about packets
or sockets, so the parts worth getting right are testable on their own:
which names exist, that a neighbouring name like `evillab` is not inside
`lab`, and the difference between a name that is absent and one that
exists with nothing of the type asked for. Getting that last one wrong
would teach a resolver to stop asking for the A record it could have
had.

Names come from signed state, which is the point: a member that is
switched off still resolves, because its claim outlived the session.
Only IPv4 is served. The IPv6 overlay address derives from a WireGuard
key that travels in live announcements and is not in signed state, so it
cannot be answered for an absent member, and answering for some members
and not others depending on who happens to be online is worse than not
answering.

`dns::server` puts that on the wire with simple-dns, which is already in
the tree through iroh — a packet codec rather than a server framework,
which is the right size for answering A records from memory. respond()
goes from bytes to bytes so everything done to a packet is tested
without a socket.

It is authoritative for one zone and refuses everything else: no
recursion, no forwarding, no cache, so pointing a resolver here can
never make it a path to the outside. A message that is not a question
gets no reply at all, rather than making this a reflector for anyone who
can spoof a source address, and ANY is answered as an address question
rather than by dumping the zone. Answers too large for the client's UDP
limit are truncated so a resolver retries over TCP instead of waiting;
TCP reads are length-checked before allocating, timed out, and bounded
in number.

The zone is shared rather than copied in, so a member joining is one
write instead of a rebind that would drop questions in flight.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-21 16:50:55 +01:00
tsunagiandClaude Opus 5 43e8ac8159 Make identity something you can look at and change
`id` now shows what this device is — the key it signs with, the name it
answers to, the secret of every network it has joined — and changes all
of it. One shape throughout: name a thing to see it, name it with a value
to change it. `secret` folded in as `id secret generate`, and the path
flags became global so they work either side of a subcommand.

There is no separate signing certificate to show: the endpoint key is
what signs records, and the report says so rather than leaving it to be
guessed.

Secrets appear in `id`, which is where you go to ask for one, and stay
out of `status`, logs, `Debug` and anything sent to a peer.

The hostname is now a signed claim, which is what makes changing it a
revocation. Records are one per author, so a new version replaces the
whole claim and no replica can keep the old name standing. RecordBody
generalised to Claim { address, range, hostname } + Release for that,
with the signing domain bumped; a name is bounded and canonicalised, and
a non-canonical one is rejected rather than repaired, because a repaired
version is not what its author signed. Two members claiming one name
resolve it like an address: lowest id wins, computed identically
everywhere. A member with only a name now has a record too, so an
IPv6-only network finally has a durable roster and an absent member can
be named rather than shown as a bare id.

Replacing the signing key is allowed and does not break the store. The
outgoing key signs a release for every network first, so the address and
name it held are freed rather than reserved forever to a key nobody has
— nothing can sign for a retired author, and by design no authority
could overrule one. Identity and releases commit together: a crash
between them would leave the old key gone and unable to sign what it
owed. It refuses while an agent holds the directory, rather than failing
on the lock with a message that says nothing about what to do.

The version counter is keyed by author as well as network, so a
replacement key starts its own sequence. The migration drops records
written under the previous signing domain instead of carrying rows that
every read must reject and that look exactly like corruption.

The hostname defaults to the machine's own name. Also fixed a
pre-existing flaky test: 40 random authors in a /24 collide by the
birthday problem often enough that its threshold failed about one run in
six, so the authors are fixed now and it tests a property rather than a
coin flip.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-21 15:59:39 +01:00
tsunagiandClaude Opus 5 776eedc669 Report members, not symptoms
A peer going away showed up as three unrelated yellow rows: no peers
authenticated, N dial failures, one packet to an address nobody owns.
Each was true and none of them said the actual thing, which is that a
member we know about is offline. Worse, they are cumulative, so after
the peer came back the report still looked broken.

Two changes behind that.

Members are now a list, joined from the three sources that each know
part of the answer: signed state says who belongs and keeps saying it
while they are away, the session list says who is here, the overlay says
whose tunnel is up. Online first, then away, this agent left out because
the device section already covers it. An absent member is stated rather
than flagged — in a mesh of laptops being away is the ordinary condition
— and its failed dials are attributed to it instead of floating free as
a network-wide number.

Counters are history and no longer grade anything. Grading them is what
kept the report red long after the cause had gone. The one exception is
context-sensitive rather than cumulative: handshake failures with nobody
connected is the signature of a mismatched secret, so that is called
out.

NetworkStatus grows a member roster from the signed records, and the
overlay report carries the endpoint id so a tunnel can be matched to its
session. Note what the roster cannot do: a member is in signed state
only once it has claimed something, which today means an IPv4 address,
so an IPv6-only network still has no durable roster. Hostnames are not
persisted either, so an absent member is named by its id.

The control socket gained a version word. Adding these fields changed
how postcard parses the bytes, and without it a client one build ahead
of its agent reported "Found an Option discriminant that wasn't 0 or 1".
The check names a mismatch for whichever side is newer; an older agent
reading a newer request just drops the connection, so the CLI offers
that as a possibility rather than asserting it. It also now separates an
agent that is absent, which is an ordinary answer, from one that is
there and will not answer, which is a fault.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-21 15:26:16 +01:00
tsunagiandClaude Opus 5 8a6fb39689 Fold doctor into status, and stop id taking the lock
`status` asked a running agent and failed without one; `doctor` checked
the host and ignored the agent. Between them they answered one question
in two halves. They are now one command: device, agent, networks, host
capability, local addresses, all graded and aligned the same way.

`id` was worse than either. It spawned a whole agent to print three
facts, which took the directory lock and so failed with "owned by
another running agent instance" exactly when the answer was most wanted.
The lock exists to keep one writer over the mandatory state; reading who
this device is needs no such thing.

So both commands now prefer the running agent, which is live and
authoritative, and fall back to the state store, which takes no lock.
StateStore gains device_identity(), which reads and never writes:
load_or_create had the side effect of deciding an identity as a
consequence of asking about one.

Presentation moved out of the library. StatusReport::render is gone and
the CLI renders the structured data, so there is one renderer rather than
two that would drift. Health gains an Info level for rows that are facts
rather than checks — an endpoint id is neither good nor bad, and a column
of green next to plain data teaches the eye to ignore the column. A
report with no checks in it now ends without a summary instead of
claiming that everything checked out.

PathAddr and TransportKind grew Display impls; both were reaching the
user through {:?}, which is how "Direct via Ip(88.198.17.44:49792)" got
printed. The transport grading compares without regard to case, because
the agent answering can be a different build from the client asking and
this field's spelling has now changed once.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-21 15:07:54 +01:00
tsunagiandClaude Opus 5 3e83e33313 Grade and colour what doctor reports
Findings now carry a level: ok, warn or FAIL. The distinction between the
middle two is the part worth getting right — warn is something the agent
runs without and that the user can fix from the line printed beneath it,
FAIL is something it cannot work around. A diagnostic that grades those
the wrong way round is worse than an ungraded one, so each check states
which it is.

The clearest case is storage: the same failure on the state directory is
FAIL and on the cache directory is warn, because one is mandatory and the
other is disposable. That asymmetry is central to the design and the
report now shows it. The control plane check also became real — it binds
a UDP socket rather than asserting that it could.

Colour is redundant by construction. Every row carries its grade as a
word, so the report reads identically when the escapes are gone: piped to
a file, on a dumb terminal, under NO_COLOR, or to someone who cannot
distinguish the colours. anstream decides whether they survive, which
also gets virtual terminal processing right on Windows; it and anstyle
were already in the tree through clap.

What is reported and how it looks are separated, so the rendering is
tested without a terminal: that a plain render contains no escapes, that
a styled one says the same thing once they are stripped, that columns
line up across sections whose labels differ in length, and that the
summary names the worst thing found.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-21 14:54:34 +01:00
tsunagiandClaude Opus 5 4759e47e31 Remove tun-setup and the attach path it served
The managed interface supersedes both. They go together because apart
they are useless: attaching needs an interface somebody prepared, and
tun-setup existed only to say how to prepare one.

This also corrects what the last commit's README claimed. It said the
manual route was needed on macOS and Windows; it was not, and could not
be. The recipe printed Linux `ip` commands, and a persistent TUN that a
second process can attach to is a Linux concept — macOS creates a utun
by opening a control socket and there is nothing to hand over. So those
platforms were never served by this path, and their honest state is that
a real interface waits on a provisioner, with --no-tun meanwhile.

Gone with it: the interface-existence check, the /proc/net/if_inet6
address inspection and its DAD flag decoding, and the --interface flag,
which had one mode left.

Kept: the check that the allocated IPv4 address is really on a local
interface. The agent now assigns that address itself, so the check is no
longer telling a user what to run — it verifies the outcome instead of
trusting it, which is worth keeping precisely because the assumptions
around Linux address behaviour have been wrong here more than once. Its
message says which interface should have had the address rather than a
command to run.

Boxing Up(UpArgs) is fallout: TunSetupArgs had been masking how much
larger that variant is than its siblings.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-21 14:46:39 +01:00
tsunagiandClaude Opus 5 b23e832a73 Manage the overlay interface instead of asking for it
The agent printed a list of `ip` commands and asked a human to run them.
That is fragile in the way hand-held setup always is: a persistent TUN
does not survive a reboot, a changed address allocation needs another
manual round, and a run that died leaves a half-configured interface the
next run trips over.

On Linux the agent now creates the interface, sets the MTU, brings it up
and assigns both overlay addresses itself, over netlink in process. No
`ip` is invoked, so nothing this path does can be influenced by PATH, a
shell, or anything a remote peer said.

Cleanup stops being an action. The interface is tied to an open file
descriptor and is deliberately not persistent, so the kernel removes it
when the agent goes — cleanly, by panic, by SIGKILL or by power loss
alike. That also retires `keep_addr_on_down` and `nodad`, which existed
only because an interface nobody held open lost carrier.

Anything still left behind is repaired rather than tripped over: an
abandoned TUN is replaced along with its stale addresses. Two cases
refuse instead of guessing — a link that is not a TUN, because a name
collision is no reason to destroy somebody's bridge, and a TUN another
process holds open, because that is a working overlay belonging to
someone else.

CAP_NET_ADMIN is kept out of the effective set except around the calls
that use it. Two facts shape how: capabilities are per thread, and
netlink checks the credentials of whichever thread calls sendmsg, which
with an async client is the connection task rather than the caller. So
netlink runs on one dedicated thread with a current-thread runtime where
nothing is polled outside a block_on, and opening the TUN descriptor is
synchronous with no await between the guard and its release.

The decision of what to change is a pure function, tested on every
platform; only the execution is behind the provisioner trait. macOS and
Windows get an implementation that refuses with an explanation and falls
back to attaching to a prepared interface, plus a mock host the tests
drive the whole plugin lifecycle against.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-21 14:33:19 +01:00
tsunagiandClaude Opus 5 944d98389f Print the allocated IPv4 address in tun-setup
The overlay IPv4 address is not derived from the keys: it is allocated at
run time and signed, so on a fresh state directory there is nothing for
tun-setup to print. Once the agent has run, the claim is in state.sqlite,
and reading it back takes no directory lock, so tun-setup can show the
`ip address add` line while the agent is running. Records are verified on
the way out; the database is not a trust boundary.

The line needs no keep_addr_on_down and no nodad, unlike its IPv6
counterpart: Linux keeps IPv4 addresses on an interface that has lost
carrier, and IPv4 has no duplicate address detection to stall.

Also fix a race in the four-agent test. A peer counts as connected once
its session authenticates, which can precede the announcement carrying
its hostname, so reading the hostnames straight away occasionally saw
only two. It now waits for them like every other success condition.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-21 14:04:44 +01:00
tsunagiandClaude Opus 5 8b333455f1 Report an allocated IPv4 address that is not on the host
IPv6 works end to end between two machines; IPv4 silently did not, and the
agent said nothing useful about why.

Allocation moved the address from something derivable before startup to
something agreed at run time, so an interface configured by an earlier
`tun-setup` carries a different address than the one allocated. The kernel
then sends packets with that stale source and every peer drops them as not
belonging to us — correct behaviour, invisible cause. Meanwhile pings to
our own allocated address fall into the tunnel and land in the "nobody
owns this" counter.

The agent now checks whether its allocated address is assigned anywhere on
the host — by binding a UDP socket to it, which needs no privileges and no
platform code — and reports the exact `ip address add` command until it
is, mentioning that another address of the range has to go.

`tun-setup` no longer prints a derived IPv4 address, because that number
is now wrong by construction. It says the agent will print the real one.

The unroutable counter keeps one destination as a sample, in status output
too. A bare count says something is wrong; the address says what.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-21 13:53:42 +01:00
tsunagiandClaude Opus 5 84c06c6cac Allocate IPv4 addresses and keep them, as signed state
Derived IPv4 addresses could not survive anything: they changed with the
range, and there was no way for a member to come back to the one it had.
Addresses are now allocated and recorded as signed facts, which is the
first slice of the model in docs/sync-model.md.

src/state/ holds one record per author per network, carrying that author's
complete current statement, signed with its persistent device key over a
length-prefixed canonical encoding. Merging follows the model's rules: a
higher version wins, an older one never rolls back a newer, duplicates are
idempotent, absence from a snapshot is not deletion, and a same-version
conflict is resolved identically on every replica and reported rather than
letting replicas diverge. Records are persisted in state.sqlite, with the
record and the author's version counter committed in one transaction
before anything is announced, and distributed as a State control message
that is merged into what the receiver already holds.

No vote, deliberately, despite the request. A majority is not a trust root
here — anyone with the secret can mint identities — and a quorum would
stall with one peer online and diverge across a partition. Signatures plus
a deterministic merge converge without either failure mode: two members
claiming one address at once are resolved by the lower endpoint id, and
the loser allocates again with a higher version.

The range moved from the plugin to the agent, defaults to 10.13.37.0/24,
and is now agreed rather than configured per member: a joining agent
adopts what the network already uses, so --ipv4-range only matters for
whoever starts it. The announcement went back to identity only (version 3)
since the range travels in signed records now.

A release tombstone exists and merges correctly, but nothing emits one
yet.

116 tests. The headline ones: an address survives restarting both agents,
three members get three distinct addresses, and a member started with a
different range adopts the one in use. Confirmed by hand with two CLI
agents restarted end to end.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-21 13:43:01 +01:00
tsunagiandClaude Opus 5 ce64264027 Make the IPv4 overlay opt-in and detect a range mismatch
100.64.0.0/10 was a bad default: it is exactly Tailscale's range, and
carrier-grade NAT's. There is no IPv4 range that is free on every host, so
there is now no default at all — IPv4 is off until --ipv4-range names one.
IPv6 is unaffected and still works out of the box, because a ULA derived
from the network id collides with essentially nothing.

The more serious problem this exposed: the range is an input to the address
derivation, and each agent derives every peer's address itself. Two members
configured with different ranges would therefore derive different addresses
for each other and IPv4 would silently misroute. So the range now travels
in the announcement — not as a request and never trusted, only so the
mismatch is seen. A peer whose range disagrees gets no IPv4 address here,
keeps working over IPv6, and the reason is reported with both ranges named.

The announcement format goes to version 2. postcard is not
self-describing, so an older peer cannot read it; the version check already
catches that and now says which side needs updating.

The (Ipv4Addr, u8) tuple that had spread across six modules is now an
Ipv4Range with validation, Display and FromStr, so a bad --ipv4-range is
refused with a reason instead of being accepted and misbehaving later. It
is also rejected when passed without --wireguard rather than ignored.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-21 13:11:09 +01:00
tsunagiandClaude Opus 5 cfab38824d Make the overlay dual stack
Every member now also derives an IPv4 address, from the same inputs as its
IPv6 one, into 100.64.0.0/10 by default. The range is configurable and IPv4
can be turned off with --no-ipv4.

IPv4 is honestly weaker than IPv6 here and the code says so. A 64 bit
interface identifier makes an IPv6 collision impossible in practice; IPv4
has nothing like that room, and in a /10 with 50 members two will derive the
same address about 0.03% of the time. A mesh with no coordinator cannot
allocate around that, so a collision is detected and resolved instead: the
member whose public key sorts lower keeps the address, a rule every member
computes identically and therefore agrees on. The other keeps IPv6 and is
flagged in the status. IPv6 always works; IPv4 almost always works and
degrades predictably.

Routing and address-ownership enforcement now cover both families: a packet
goes to the peer that owns its destination, and a decrypted packet is
dropped unless its source is an address derived for the peer that sent it,
IPv4 included.

Six new tests, among them a real IPv4 packet crossing a tunnel next to an
IPv6 one, a spoofed IPv4 source being dropped, and an IPv6-only overlay.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-21 13:00:35 +01:00
tsunagiandClaude Opus 5 be459e5bd0 Add tsunagi status over a local control socket
There was no way to ask a running agent what it was doing; the only status
came from the periodic print of the `up` process itself.

The new ipc module is an adapter over the public API: nothing in the agent
core knows it exists, so a Windows named pipe or an authenticated loopback
socket can be added beside it. It is also a different interface from the
peer-to-peer protocol — between processes on one machine, authorised by
filesystem permissions rather than the network secret. The socket is 0600
inside an owner-only directory, the wire format is length-prefixed postcard
with the same bounds the network protocol uses, and the report types are
their own stable format rather than the crate's internals.

The socket path is derived from the state directory into XDG_RUNTIME_DIR
when there is one. A Unix socket address is limited to about 100 bytes, and
a deeply nested state directory overflows it — which is exactly what
happened on the first attempt.

Two presentation fixes while here. Multicast is counted separately from
unroutable traffic, because Linux emits multicast on every IPv6 interface
and it was showing up as "packets for unknown addresses" on a healthy
agent. And WireGuard protocol errors are no longer added into the dropped
counter: a few are normal while both ends start a handshake at once, and a
working tunnel was reporting "dropped 3" with no traffic at all.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-21 12:53:04 +01:00
tsunagiandClaude Opus 5 d2e336f2f9 Raise the overlay MTU to 1280: below that Linux disables IPv6
The setup recipe failed with a missing sysctl directory and "RTNETLINK
answers: Invalid argument". The cause was the default MTU of 1100.

IPv6 requires a minimum MTU of 1280 (RFC 8200) and Linux enforces it by
tearing IPv6 down on any interface below it: the per-device
/proc/sys/net/ipv6/conf entries disappear and an address can no longer be
assigned. Evidence on the test host: every interface at 1280 or above has
an IPv6 conf directory, every interface below it (1230, 1100) has none.

So the overlay MTU is now 1280, which is also the floor. A smaller value is
refused when the plugin opens, naming the reason, rather than surfacing as
an obscure netlink error after the user has already run four commands.

That leaves no slack against the other constraint: a packet needs mtu + 32
bytes of transport datagram, so 1312. A direct QUIC path offers roughly
1380 and fits; a relayed path may not, so the plugin now reports the exact
numbers when a link cannot carry a full-size packet, instead of only
counting silent drops.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-21 12:41:57 +01:00
tsunagiandClaude Opus 5 38beb762d8 Fix the TUN setup recipe: the overlay address was being flushed
The setup this tool printed did not work, and the agent then correctly
refused to start. A persistent TUN interface has no carrier until a process
attaches to it, and Linux flushes IPv6 addresses from an interface that
loses carrier unless net.ipv6.conf.<dev>.keep_addr_on_down is set, which it
is not by default. So `ip -6 address add` on a freshly created interface
silently lost the address before the agent ever ran.

The recipe now brings the link up first, sets keep_addr_on_down, and adds
the address with `nodad` — without which duplicate address detection can
never finish on an interface with no carrier and the address stays
tentative and unusable.

The agent's own retry loop made this worse: it attached, failed the address
check, dropped the device and toggled the carrier, which flushed the
address again. The check now runs before attaching to an existing
interface, so looking is not destructive.

Failures are self-diagnosing now: the check parses the IFA_F_* flags, tells
tentative and DAD-failed apart from missing, and lists the addresses the
interface actually has.

Four new tests, including one that reads this host's real /proc/net/if_inet6
and one that pins the ordering of the setup commands.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-21 12:36:16 +01:00
tsunagiandClaude Opus 5 0f8a4eb485 Issue no privileged ioctl when attaching to a prepared interface
The tun crate runs configure() by default (ensure_root_privileges is true),
which is harmless today because it only acts on fields that were set, and
the attach path sets none. Saying so explicitly documents the intent and
keeps it true if the crate changes.

Also records why packet information stays off: `ip tuntap add ... mode tun`
defaults to no packet information too, so the TUNSETIFF flags match when
attaching and reads and writes stay raw IP packets.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-21 12:28:28 +01:00
tsunagiandClaude Opus 5 1dd7507bf4 Let the agent run unprivileged against a prepared TUN interface
Creating a network interface needs CAP_NET_ADMIN, but that is a one-time
setup step rather than something the agent must hold for its whole life.

SystemTunFactory now attaches to an interface that already exists and only
creates one when it does not. A persistent interface created by root and
owned by the user therefore lets the agent run with no privileges and no
capabilities at all. When attaching, nothing is reconfigured, since doing so
would need exactly the privileges we are avoiding.

New `tsunagi tun-setup` prints the three commands to run once as root,
resolving the derived interface name and overlay address for the network.

This also fixes a real gap: the overlay address was passed to the factory
and thrown away, so an interface the agent created had no address and could
never have received anything. The `tun` crate sets addresses through an
IPv4-only ioctl and cannot assign an IPv6 one at all, so the agent now
verifies the address is present via /proc/net/if_inet6 and refuses with the
exact command to run instead of coming up broken. Doing it in-process would
mean speaking netlink, which is not implemented and is recorded as such.

Not verified on this machine: no sudo is available here, so the privileged
setup and the attach path were not executed end to end.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-21 12:23:37 +01:00